Systems and methods for determining leaks in respiratory flow therapy systems - Patents.com

Abstract

A respiratory apparatus for providing a flow of gas to a user for respiratory therapy, the respiratory apparatus comprising a controller operable to execute one or more leak detection algorithms to determine leaks and / or missing components in a flow path, the leak detection algorithms comparing pressure and / or flow signals to one or more thresholds using a two-stage evaluation process to determine a leak.

Description

[Technical field]

[0001] The present disclosure relates to methods and systems for providing respiratory flow therapy to a patient. In particular, the present disclosure relates to determining leaks in a flow path of a respiratory device that delivers a flow of gas to a patient through a non-sealing interface. [Background technology]

[0002] Respiratory support apparatus are used to deliver a flow of gas to a user or patient in a variety of environments, such as hospitals, medical facilities, residential care or home environments. Respiratory support apparatus or respiratory therapy apparatus (collectively, "respiratory apparatus" or "respiratory devices") may be used to deliver supplemental oxygen or other gases along with the gas flow, and / or a humidification device may be used to deliver heated and humidified gas. Respiratory apparatus may allow for regulation and control of characteristics of the gas flow, including flow rate, temperature, gas concentration, humidity, pressure, etc. Sensors, such as flow and / or pressure sensors, are used to measure the characteristics of the gas flow. Summary of the Invention [Means for solving the problem]

[0003] The present disclosure provides methods and processes for detecting one or more leaks in the flow path of a respiratory device. In one configuration, the respiratory device is a "non-sealed system" that provides high-flow therapy (high-flow oxygen therapy). High-flow therapy can typically be a nasal high-flow system that delivers gas flow through a non-sealed interface, such as a nasal cannula, or a tracheotomy high-flow system that delivers gas flow through a tracheotomy interface. In some configurations, the leak detection algorithm can operate while the patient is connected or partially connected (i.e., the interface is attached or partially attached) and receiving treatment, and / or when the patient is disconnected from the system (i.e., the interface is disconnected). In a non-sealed interface system, such as a nasal high-flow system, it is difficult to determine leaks in the flow path of the device due to the open and non-sealed nature of the system.

[0004] The processes disclosed herein can be used where the patient interface is a non-sealing device, such as a nasal cannula in nasal high-flow therapy, or through a non-sealing tracheal interface to provide tracheotomy high-flow therapy, collectively known as "high-flow therapy."

[0005] In one aspect, the present disclosure provides a respiratory apparatus configured to provide a flow of gas to a user for respiratory therapy, comprising: a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus to a gas outlet of the breathing apparatus; a humidifier operable to heat and humidify a gas flow, the humidifier including a removable humidification chamber in a flow path; a pressure sensor configured to generate a pressure variable representative of a sensed pressure characteristic of the flow of gas in the flow passage; a controller operatively connected to the flow generator and operable to control a flow rate of the gas flow by controlling a motor speed of the flow generator, the controller comprising: initiating a first stage leak assessment including comparing the pressure variable to a first leak threshold, the first leak threshold representing a possible leak condition; initiating a second stage of leak assessment when the pressure variable falls below the first leak threshold, thereby indicating a possible leak, the second stage of leak assessment comprising: increasing a flow generator motor speed from a current motor speed to a higher motor speed; comparing the new pressure variable at the higher motor speed to a first leak threshold and a second leak threshold, the second leak threshold being indicative of a confirmed leak condition; generating a leak alarm and terminating the second stage of leak evaluation if the new pressure variable falls below a second leak threshold, thereby confirming the possible leak as a definite leak; or terminating the second stage leak evaluation without generating an alarm if the new pressure variable exceeds the first leak threshold and the second leak threshold, thereby determining the potential leak as no leak; or repeating the second stage leak assessment at one or more additional higher motor speeds until the possible leak is confirmed as a leak or determined as no leak; and a controller configured to execute a leak detection process to detect leaks in the flow path by The present invention relates to a breathing apparatus comprising:

[0006] In one configuration, the first stage leak assessment includes comparing the pressure variable to a first leak threshold and a second leak threshold, and the controller is configured to initiate the second stage leak assessment when the pressure variable falls below the first leak threshold and exceeds the second leak threshold, thereby indicating a possible leak.

[0007] In one configuration, the first stage leak assessment includes comparing the pressure variable to a second leak threshold, and the controller is configured to generate a leak alarm if the pressure variable falls below the second leak threshold.

[0008] In one configuration, the controller is configured to repeat or continue the first stage leak assessment during normal operation until an exit condition occurs.

[0009] In one configuration, the exit condition includes generating a leak alarm or initiating a second stage leak evaluation to determine the potential leak as a definite leak or no leak.

[0010] In one configuration, increasing the flow generator motor speed in the second stage leak assessment includes increasing the motor speed in set increments to a higher motor speed or to the next higher motor speed from a predetermined series or sequence of higher motor speeds.

[0011] In one configuration, in the second stage leak assessment, the controller is configured to hold the flow generator at the higher motor speed for a predetermined period of time while comparing the new pressure variable to the first and / or second leak thresholds to determine the likelihood of a leak as a definite leak or no leak.

[0012] In one configuration, the controller is configured to repeat the second stage leak assessment at a next further higher motor speed if a possible leak is not identified as a leak and determined to be no leak at the current higher motor speed within a predetermined period of time.

[0013] In one configuration, the controller is configured to terminate the second stage of leak assessment in response to a comparison of the current motor speed to a motor speed threshold.

[0014] In one configuration, the controller is configured to terminate the second stage leak assessment if the current higher motor speed at which the motor is operating during the second stage leak assessment does not fall below the motor speed threshold.

[0015] In one configuration, the controller is configured to adjust the first leak threshold if the second stage leak assessment is completed without generating an alarm.

[0016] In one configuration, the controller is configured to adjust the first leak threshold by lowering the first leak threshold associated with the flow rate and / or motor speed operating during the first stage leak assessment.

[0017] In one configuration, the values ​​of the first and second leak thresholds depend, at least in part, on or are a function of the flow rate and / or motor speed operating at the time of the comparison.

[0018] In one configuration, the first and second leak thresholds are derived from respective pressure-flow characteristic curves and / or representative look-up tables that specify thresholds for various flow rates and / or motor speeds.

[0019] In one configuration, the controller is configured to determine, during the leak assessment phase, a respective comparative assessment of the pressure variable against the first and / or second leak thresholds based on whether the pressure variable is consistently above or below the threshold over a respective shortest assessment period.

[0020] In one configuration, each minimum evaluation period is determined by a predetermined comparison evaluation and / or a predetermined leak evaluation stage.

[0021] In one configuration, the minimum evaluation period associated with the comparison evaluation in the second stage leak evaluation is shorter than the minimum evaluation period associated with the comparison evaluation in the previous first stage leak evaluation.

[0022] In one configuration, the controller is configured to initiate one or more alarm actions upon generating a leak alarm.

[0023] In one configuration, the alarm action includes freezing the flow generator flow rate and / or motor speed to the current operating settings.

[0024] In one configuration, the alarm action includes generating a notice or indication of the leak on a display of the device.

[0025] In one configuration, the leak alarm indicates that the removable humidification chamber has been at least partially or wholly removed or disconnected from the flow path of the device.

[0026] In one configuration, the leak alarm indicates that the patient circuit has been at least partially or wholly removed or disconnected from the gas outlet of the device.

[0027] In one configuration, the controller is operable to detect one or more different types of leaks in the flow path of the device, each different type of leak having its own respective first and second leak thresholds.

[0028] In one configuration, after the alarm is generated, the controller is configured to maintain the alarm until the pressure variable rises above the second leak threshold or an alternative leak clearance threshold for a minimum period of time.

[0029] In one configuration, after an alarm is generated, the controller is configured to disable the alarm and return to normal operation if the pressure variable rises above the second leak threshold or an alternative leak elimination threshold for a minimum period of time.

[0030] In one configuration, the controller is configured to operate the leak detection process continuously without modification over the entire or substantial portion of the operating flow rate range of the device. In one example, the leak detection process is operable over the entire operating flow rate range of the device, which may be from 0 L / min to 90 L / min, and with a variety of different types and / or sizes of patient interfaces.

[0031] In one configuration, the respiratory apparatus comprises a patient circuit including a patient interface connected to the gas outlet, and the controller is configured to operate the leak detection process continuously without modification for a variety of different types or sizes of patient interfaces.

[0032] In one configuration, the humidifier of the respiratory apparatus further comprises a heater plate operable to heat the humidification chamber, and the controller is further configured to perform a heater plate check process to further confirm or validate a certain leak identified in the second stage leak assessment before generating a leak alarm.

[0033] In one configuration, the heater plate check process includes applying a power or temperature process to the heater plate and evaluating the heating and / or cooling rates of the heater plate against one or more thresholds based on temperature sensors of or associated with the heater plate, thereby determining the presence or absence of a humidification chamber in thermal contact with the heater plate, the absence of the humidification chamber confirming a positive leak condition.

[0034] In another aspect, the present disclosure provides a method for detecting a leak in a flow path of a respiratory device configured to provide a flow of gas to a user at a controllable flow rate for respiratory therapy, the method comprising: receiving a pressure variable from a pressure sensor of the apparatus, the pressure variable representing a sensed pressure characteristic of the flow of gas in the flow path; initiating a first stage leak assessment including comparing the pressure variable to a first leak threshold, the first leak threshold representing a possible leak condition; initiating a second stage of leak assessment when the pressure variable falls below the first leak threshold, thereby indicating a possible leak, the second stage of leak assessment comprising: increasing a flow generator motor speed from a current motor speed to a higher motor speed; comparing the new pressure variable at the higher motor speed to a first leak threshold and a second leak threshold, the second leak threshold being indicative of a confirmed leak condition; generating a leak alarm and terminating the second stage of leak evaluation if the new pressure variable falls below a second leak threshold, thereby confirming the possible leak as a definite leak; or terminating the second stage leak evaluation without generating an alarm if the new pressure variable exceeds the first leak threshold and the second leak threshold, thereby determining the potential leak as no leak; or repeating the second stage leak assessment at one or more additional higher motor speeds until the possible leak is confirmed as a leak or determined as no leak; and The present invention relates to a method comprising the steps of:

[0035] In one configuration, the first stage leak assessment includes comparing the pressure variable to a first leak threshold and a second leak threshold, and the method includes initiating a second stage leak assessment when the pressure variable is below the first leak threshold and above the second leak threshold, thereby indicating a possible leak.

[0036] In one configuration, the first stage leak assessment includes comparing the pressure variable to a second leak threshold and generating a leak alarm if the pressure variable falls below the second leak threshold.

[0037] In one configuration, the method includes repeating the first stage leakage assessment during normal operation until an exit condition occurs.

[0038] In one configuration, the exit condition includes generating a leak alarm or initiating a second stage leak evaluation to determine the potential leak as a definite leak or no leak.

[0039] In one configuration, increasing the flow generator motor speed in the second stage leak assessment includes increasing the motor speed in set increments to a higher motor speed or to the next higher motor speed from a predetermined series or sequence of higher motor speeds.

[0040] In one configuration, in the second stage leak assessment, the method includes holding the flow generator at the higher motor speed for a predetermined period of time while comparing the new pressure variable to the first and / or second leak thresholds to determine the likelihood of a leak as a definite leak or no leak.

[0041] In one configuration, the method includes repeating a second stage leak assessment at a next further higher motor speed if a possible leak is not identified as a leak and determined to be no leak at the current higher motor speed within a predetermined period of time.

[0042] In one configuration, the method includes terminating the second stage leak assessment in response to a comparison of the current motor speed to a motor speed threshold.

[0043] In one configuration, the method includes terminating the second stage leak assessment if the current higher motor speed operating during the second stage leak assessment does not fall below the motor speed threshold.

[0044] In one configuration, the method includes adjusting the first leak threshold if the second stage leak assessment is completed without generating an alarm.

[0045] In one configuration, the method includes adjusting a first leak threshold by lowering a first leak threshold associated with an operating flow rate and / or motor speed during the first stage leak assessment.

[0046] In one configuration, the values ​​of the first and second leak thresholds depend, at least in part, on or are a function of the flow rate and / or motor speed operating at the time of the comparison.

[0047] In one configuration, the method includes deriving the first and second leakage thresholds from respective pressure-flow characteristic curves and / or representative look-up tables that specify thresholds for various flow rates and / or motor speeds.

[0048] In one configuration, the method includes, during the leak assessment phase, determining a respective comparative assessment of the pressure variable against a first and / or second leak threshold based on whether the pressure variable is consistently above or below the threshold over a respective shortest assessment period.

[0049] In one configuration, the minimum evaluation period is determined by a predetermined comparison evaluation and / or a predetermined leak evaluation stage.

[0050] In one configuration, the minimum evaluation period associated with the comparison evaluation in the second stage leak evaluation is shorter than the minimum evaluation period associated with the comparison evaluation in the previous first stage leak evaluation.

[0051] In one configuration, the method includes initiating one or more alarm actions upon generating the leak alarm.

[0052] In one configuration, the alarm action includes freezing the flow generator flow rate and / or motor speed to the current operating settings.

[0053] In one configuration, the alarm action includes generating a notice or indication of the leak on a display of the device.

[0054] In one configuration, the leak alarm indicates that the removable humidification chamber has been at least partially or wholly removed or disconnected from the flow path of the device.

[0055] In one configuration, the leak alarm indicates that the patient circuit has been at least partially or wholly removed or disconnected from the gas outlet of the device.

[0056] In one configuration, the method includes detecting one or more different types of leaks in a flow path of the device, each different type of leak having its own respective first and second leak thresholds.

[0057] In one configuration, after the alarm is generated, the method includes maintaining the alarm until the pressure variable rises above the second leak threshold or an alternative leak clearance threshold for a minimum period of time.

[0058] In one configuration, after the alarm is generated, the method includes disabling the alarm and returning to normal operation if the pressure variable rises above the second leak threshold or an alternative leak elimination threshold for a minimum period of time.

[0059] In one configuration, the apparatus comprises: a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus to a gas outlet of the breathing apparatus; a humidifier operable to heat and humidify a gas flow, the humidifier including a removable humidification chamber in a flow path; a pressure sensor configured to generate a pressure variable representative of a sensed pressure characteristic of the flow of gas in the flow passage; a controller operatively connected to the flow generator and operable to control a motor speed of the flow generator and thereby a flow rate of the gas flow, the method being executable or capable of being carried out by the controller; Equipped with.

[0060] In one configuration, the method operates continuously without modification over all or a substantial portion of the operating flow rate range of the device, which in some embodiments may be, for example, from 0 L / min to 90 L / min.

[0061] In one configuration, the respiratory apparatus comprises a patient circuit including a patient interface connected to the gas outlet, and the method works continuously without modification for a variety of different types or sizes of patient interfaces.

[0062] In another aspect, the present disclosure provides a respiratory apparatus configured to provide a flow of gas to a user for respiratory therapy, the apparatus comprising: a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus to a gas outlet of the breathing apparatus; a humidifier operable to heat and humidify a gas flow, the humidifier including a removable humidification chamber in a flow path; a pressure sensor configured to generate a pressure variable representative of a sensed pressure characteristic of the flow of gas in the flow passage; a controller operatively connected to the flow generator and operable to control a flow rate of the gas flow by controlling a motor speed of the flow generator, the controller comprising: receiving a pressure variable from a pressure sensor at a first flow rate; determining whether a possible leak condition is met based on comparing the received pressure variable to a first threshold, the first threshold being indicative of the possible leak condition; If a possible leak condition is met, increasing a motor speed of the flow generator to generate a second flow rate for the gas flow; receiving an updated pressure variable at a second flow rate; determining whether a possible leak condition, a no leak condition, or a certain leak condition is met by comparing the updated pressure variable to a first threshold and / or a second threshold, the second threshold representing a certain leak condition; If at the second flow rate the potential leak condition is met again, successively increasing the flow generator motor speed in discrete increments to increase the flow rate of gas at discrete intervals, and again comparing the updated pressure variable to the first and / or second thresholds after each discrete increment until either a confirmed leak condition or a no leak condition is met; A controller configured to: The present invention relates to a breathing apparatus comprising:

[0063] In one configuration, a possible leak condition is met if the pressure variable falls below a first threshold value.

[0064] In one configuration, a possible leak condition is met when the pressure variable is below a first threshold and above a second threshold.

[0065] In one configuration, the no leak condition is met if the pressure variable exceeds the first and second threshold values.

[0066] In one configuration, a positive leak condition is met if the pressure variable falls below a second threshold.

[0067] In one configuration, the controller is configured to determine whether a condition is met based on whether the pressure variable is above or below an associated first and / or second threshold value for a minimum evaluation period.

[0068] In one configuration, the minimum evaluation period depends on the predetermined condition being evaluated.

[0069] In one configuration, the humidifier of the respiratory apparatus further comprises a heater plate operable to heat the humidification chamber, and the controller is further configured to perform a heater plate check process to further confirm or validate a certain leak identified in the second stage leak assessment before generating a leak alarm.

[0070] In one configuration, the heater plate check process includes applying a power or temperature process to the heater plate and evaluating the heating and / or cooling rates of the heater plate against one or more thresholds based on temperature sensors of or associated with the heater plate, thereby determining the presence or absence of a humidification chamber in thermal contact with the heater plate, the absence of the humidification chamber confirming a positive leak condition.

[0071] In one aspect, the present disclosure provides a method for detecting a leak in a flow path of a respiratory device configured to provide a flow of gas to a user at a controllable flow rate for respiratory therapy, the method comprising: receiving a pressure variable from a pressure sensor of the device operating at the first flow rate, the pressure variable representing a sensed pressure characteristic of the flow of gas in the flow path; determining whether a possible leak condition is met based on comparing the received pressure variable to a first threshold, the first threshold being indicative of the possible leak condition; If a possible leak condition is met, increasing a motor speed of the flow generator to generate a second flow rate for the gas flow; receiving an updated pressure variable at a second flow rate; determining whether a possible leak condition, a no leak condition, or a certain leak condition is met by comparing the updated pressure variable to a first threshold and / or a second threshold, the second threshold representing a certain leak condition; If at the second flow rate the potential leak condition is met again, successively increasing the flow generator motor speed in discrete increments to increase the flow rate of gas at discrete intervals and again comparing the updated pressure variable to the first and / or second thresholds until either a confirmed leak condition or a no leak condition is met; The present invention relates to a method comprising the steps of:

[0072] In one configuration, the method includes determining that a potential leak condition is met if the pressure variable is below a first threshold.

[0073] In one configuration, the method includes determining that a potential leak condition is met when the pressure variable is below a first threshold and above a second threshold.

[0074] In one configuration, the method includes determining that a no-leak condition is met if the pressure variable exceeds first and second thresholds.

[0075] In one configuration, the method includes determining that a certain leak condition is met if the pressure variable falls below a second threshold.

[0076] In one configuration, the method includes determining whether a condition is met based on whether the pressure variable is above or below an associated first and / or second threshold value for a minimum evaluation period.

[0077] In one configuration, the minimum evaluation period depends on the predetermined condition being evaluated.

[0078] In another aspect, the present disclosure provides a respiratory apparatus configured to provide a flow of gas to a user for respiratory therapy, the apparatus comprising: a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus to a gas outlet of the breathing apparatus; a humidifier operable to heat and humidify a gas flow, the humidifier including a removable humidification chamber in a flow path; a pressure sensor configured to generate a pressure variable representative of a sensed pressure characteristic of the flow of gas in the flow passage; a controller operatively connected to the flow generator and operable to control a flow rate of the gas flow by controlling a motor speed of the flow generator, the controller comprising: controlling a flow generator or a flow generator motor speed to deliver a flow of gas at a configurable user set flow rate during normal operation; receiving a pressure variable from a pressure sensor; Continue normal operation if the pressure variable exceeds the leak threshold, thereby indicating that no leak has been detected; or if the pressure variable falls below a leak threshold, indicating a possible leak has been detected, increasing or ramping up a motor speed or user set flow rate of the flow generator by a predetermined or dynamically determined increment and receiving an updated pressure variable from the pressure sensor at the new increased motor speed or increased user set flow rate; generating an alarm and / or fixing the motor speed if the updated pressure variable falls below a leak threshold, thereby confirming a potential leak as a leak; or if the pressure variable exceeds the leak threshold, thereby determining that the potential leak is not a leak, returning to normal operation of the flow generator at the original user set flow rate; A controller configured to: The present invention relates to a breathing apparatus comprising:

[0079] In another aspect, the present disclosure provides a method for detecting a leak in a flow path of a respiratory device configured to provide a flow of gas to a user at a controllable flow rate for respiratory therapy, the method comprising: controlling a flow generator or a flow generator motor speed to deliver a flow of gas at a configurable user set flow rate during normal operation; receiving a pressure variable from a pressure sensor of the device operating at a user-set flow rate, the pressure variable representing a sensed pressure characteristic of the gas flow in the flow path; Continue normal operation if the pressure variable exceeds the leak threshold, thereby indicating that no leak has been detected; or if the pressure variable falls below a leak threshold indicating a possible detected leak, increasing or ramping up a motor speed or user set flow rate of the flow generator by a predetermined or dynamically determined increment and receiving an updated pressure variable from the pressure sensor at the new increased motor speed or increased user set flow rate; generating an alarm and / or fixing the motor speed if the updated pressure variable falls below a leak threshold, thereby confirming a potential leak as a leak; or if the pressure variable exceeds the leak threshold, thereby determining the potential leak to be no leak, returning to normal operation of the flow generator at the original user set flow rate; The present invention relates to a method comprising the steps of:

[0080] In another aspect, the present disclosure provides a respiratory apparatus configured to provide a flow of gas to a user for respiratory therapy, the apparatus comprising: a housing having a receiving portion for receiving a removable humidification chamber; a motor-driven flow generator within the housing operable to generate a flow of gas; a gas inlet and a gas outlet in the housing; a flow path for the flow of gas through the respiratory apparatus, in use, from the gas inlet, through the flow generator and the humidification chamber to the gas outlet, the flow path being in fluid communication with the flow generator and the gas outlet when the humidification chamber is positioned in an operative position within the receptacle of the housing; a pressure sensor configured to generate a pressure variable representative of a sensed pressure characteristic of the flow of gas in the flow passage; A controller, controlling a flow generator to generate a flow of gas at a configurable user set flow rate; receiving a pressure variable from a pressure sensor; initiating a first stage leak assessment including comparing the pressure variable to a first leak threshold, the first leak threshold representing a possible leak condition and being a function of a current flow rate and / or motor speed; initiating a second stage of leak assessment when the pressure variable falls below the first leak threshold, thereby indicating a possible leak, the second stage of leak assessment comprising: increasing a flow generator motor speed from a current motor speed to a higher motor speed; comparing the new pressure variable at the higher motor speed to a first leak threshold and a second leak threshold, the second leak threshold representing a confirmed leak condition and being a function of the current flow rate and / or motor speed; generating a leak alarm and terminating the second stage of leak evaluation if the new pressure variable falls below a second leak threshold, thereby confirming the possible leak as a definite leak; or terminating the second stage leak evaluation if the new pressure variable exceeds the first leak threshold and the second leak threshold, thereby determining the potential leak as no leak; or repeating the second stage leak assessment at one or more additional higher motor speeds until an alarm occurs or an end of the second stage leak assessment occurs; and A controller configured to: The present invention relates to a breathing apparatus comprising:

[0081] In another aspect, a method of determining whether a removable humidification chamber has been removed from a respiratory therapy flow path, the respiratory device comprising: a housing having a receptacle for receiving the removable humidification chamber; a motor driven flow generator within the housing operable to generate a flow of gas; a gas inlet and a gas outlet within the housing; a flow path for the flow of gas through the respiratory device, in use, from the gas inlet through the flow generator and the humidification chamber to the gas outlet, the flow path being in fluid communication with the flow generator and the gas outlet when the humidification chamber is positioned in an operative position within the receptacle of the housing; a pressure sensor configured to generate a pressure variable representative of a sensed pressure characteristic of the flow of gas in the flow path; and a controller, the method comprising: controlling a flow generator to generate a flow of gas at a configurable user set flow rate; receiving a pressure variable from a pressure sensor; initiating a first stage leak assessment including comparing the pressure variable to a first leak threshold, the first leak threshold representing a possible leak condition and being a function of a current flow rate and / or motor speed; initiating a second stage of leak assessment when the pressure variable falls below the first leak threshold, thereby indicating a possible leak, the second stage of leak assessment comprising: increasing a flow generator motor speed from a current motor speed to a higher motor speed; comparing the new pressure variable at the higher motor speed to a first leak threshold and a second leak threshold, the second leak threshold representing a confirmed leak condition and being a function of the current flow rate and / or motor speed; generating a leak alarm and terminating the second stage of leak evaluation if the new pressure variable falls below a second leak threshold, thereby confirming the possible leak as a definite leak; or terminating the second stage leak evaluation if the new pressure variable exceeds the first leak threshold and the second leak threshold, thereby determining the potential leak as no leak; or repeating the second stage leak assessment at one or more additional higher motor speeds until an alarm occurs or an end of the second stage leak assessment occurs; and The present invention relates to a method comprising the steps of:

[0082] In another aspect, the present disclosure provides a respiratory apparatus configured to provide a flow of gas to a user for respiratory therapy, the apparatus comprising: a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus to a gas outlet of the breathing apparatus; a humidifier operable to heat and humidify a gas flow, the humidifier including a removable humidification chamber in a flow path; a pressure sensor configured to generate a pressure variable representative of a sensed pressure characteristic of the flow of gas in the flow passage; a controller operatively connected to the flow generator and operable to control a flow rate of the gas flow by controlling a motor speed of the flow generator, the controller comprising: controlling a flow generator or a flow generator motor speed to deliver a flow of gas at a configurable user set flow rate; If the user-set flow rate is below a first flow rate threshold or within a first flow rate range, determining whether there is a leak based on comparing the pressure variable to one or more leak thresholds, and if a conclusive determination of leak or no leak cannot be made; increasing or raising the user set flow rate or flow generator motor speed by a set increment and again determining whether there is a leak or no leak based on one or more leak thresholds; if a leak or no leak can again not be conclusively determined, successively increasing or raising the user set flow rate or motor speed in further set increments, again determining whether there is a leak or no leak after each increment until a leak or no leak is reliably determined; By this, the leakage in the flow path is checked, and A controller configured to: The present invention relates to a breathing apparatus comprising:

[0083] In one configuration, if the user set flow rate is above a first flow rate threshold, the controller: At a current user-set flow rate and / or motor speed of the flow generator, comparing the pressure variable to a leak threshold and determining a leak if the pressure variable is below the leak threshold or determining no leak if the pressure variable is above the leak threshold. The device is configured to check for leaks in the flow path.

[0084] In one configuration, the humidifier of the respiratory apparatus further comprises a heater plate operable to heat the humidification chamber, and the controller is further configured to perform a heater plate check process to further confirm or validate the determined positive leak.

[0085] In one configuration, the heater plate check process includes applying a power or temperature process to the heater plate and evaluating the heating and / or cooling rates of the heater plate against one or more thresholds based on temperature sensors of or associated with the heater plate, thereby determining the presence or absence of a humidification chamber in thermal contact with the heater plate, the absence of the humidification chamber confirming the determined positive leak.

[0086] In another aspect, the present disclosure provides a method for determining a leak in a flow path of a respiratory apparatus, the method comprising: controlling a flow generator or a flow generator motor speed to deliver a flow of gas at a configurable user set flow rate; If the user-set flow rate is below a first flow rate threshold or within a first flow rate range, determining whether there is a leak based on comparing the pressure variable of the gas flow to one or more leak thresholds, and if a conclusive determination of leak or no leak cannot be made; increasing or raising the user set flow rate or flow generator motor speed by a set increment and again determining whether there is a leak or no leak based on one or more leak thresholds; if a leak or no leak can again not be conclusively determined, successively increasing or raising the user set flow rate or motor speed in further set increments, again determining whether there is a leak or no leak after each increment until a leak or no leak is reliably determined; By this, the leakage in the flow path is checked, and A controller configured to: The present invention relates to a method comprising the steps of:

[0087] In one configuration, if the user set flow rate exceeds a first flow rate threshold: At a current user-set flow rate and / or motor speed of the flow generator, comparing the pressure variable to a leak threshold and determining a leak if the pressure variable is below the leak threshold or determining no leak if the pressure variable is above the leak threshold. Check for leaks in the flow path.

[0088] In another aspect, the present disclosure relates to a method of determining a leak condition of a humidification chamber in a respiratory apparatus, wherein a controller of the respiratory apparatus implements or executes any one of the above or below described methods.

[0089] In another aspect, the present disclosure relates to a controller of a respiratory apparatus comprising a processor configured to perform or execute any one of the above or below described methods.

[0090] In another aspect, the present disclosure relates to a method of determining a leak in a flow path of a respiratory apparatus by any one of the methods described above, except that the apparatus is operating in a non-therapeutic mode, such as a drying mode and / or a disinfection mode.

[0091] In another aspect, the present disclosure provides a method for determining a leak in a flow path of a respiratory apparatus operating in a non-therapeutic mode, the method comprising: controlling the flow generator or a flow generator motor speed according to a non-therapy mode setting; determining whether there is a leak based on comparing the pressure variable of the gas flow to one or more leak thresholds, and if a conclusive determination of leak or no leak cannot be made; increasing or ramping up the flow rate or flow generator motor speed by a set increment and again determining whether there is a leak or no leak based on one or more leak thresholds; if a leak or no leak can again not be conclusively determined, successively increasing or raising the user set flow rate or motor speed in further set increments, again determining whether there is a leak or no leak after each increment until a leak or no leak is reliably determined; The present invention relates to a method comprising the steps of:

[0092] In one configuration, the non-treatment mode is a drying mode and / or a disinfecting mode.

[0093] In one configuration, the one or more leak thresholds are based at least in part on or are a function of flow path characteristics and / or operational settings associated with the drying mode and / or the sanitizing mode.

[0094] In another aspect, the present disclosure relates to a respiratory apparatus configured to provide a flow of heated and humidified gas to a patient, the apparatus being capable of providing high-flow therapy to a patient or user. a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus to a gas outlet of the breathing apparatus; a humidifier operable to heat and humidify a gas flow, the humidifier including a removable humidification chamber, the removable chamber being removable from the flow path such that when the chamber is in an operable position, the flow path extends through the chamber to an outlet; a pressure sensor configured to generate a signal indicative of a pressure of the gas flow; a flow sensor configured to generate a signal indicative of a flow rate of the gas flow; a motor speed sensor associated with the flow generator motor, the motor speed sensor configured to generate a signal indicative of a motor speed of the motor; a controller operatively connected to the flow generator for controlling a flow rate of the gas flow, the controller being in electronic communication with the pressure sensor, the flow sensor, and the motor speed sensor; performing a first leak detection method using one or more of a pressure sensor, a flow sensor, and a motor speed sensor; generating an alarm if the first leak detection method generates confirmation of a leak; if the first leak detection method outputs a possible leak condition, executing a second leak detection method, incrementally increasing the motor speed in predetermined increments until the second leak detection method determines a positive leak or a positive no leak condition as determined by the controller;

[0023] 20. The method according to claim 1, further comprising: a first leak detection method including assessing a measured gas pressure at one of two thresholds relative to a current measured flow rate by the flow sensor; and a second leak detection method including comparing the measured pressure at the measured flow rate to a leak threshold to confirm a positive leak condition or a positive no leak condition; the controller is configured to incrementally increase the motor speed in set increments by measuring the motor speed using a motor speed sensor; A controller; Equipped with.

[0095] In some embodiments, the device advantageously performs a two-stage leak detection to determine if there is a leak in the flow path, which is a gross leak caused by removal of the humidification chamber and / or conduit connected to the outlet.

[0096] In some embodiments, the device comprises a housing, and the flow generator and the humidifier are located within a common housing. The housing can comprise a receptacle for receiving the humidifier chamber. The controller is configured to perform an action if a confirmed leak is determined.

[0097] In another aspect, the present disclosure is a respiratory apparatus operable in a disinfection mode to disinfect one or more components in a flow path of the apparatus, the respiratory apparatus comprising: a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus; a removable disinfection kit or assembly forming part of the flow path; a pressure sensor configured to generate a pressure variable representative of a sensed pressure characteristic of the flow of gas in the flow passage; a controller operatively connected to the flow generator and operable to control a flow rate of the gas flow by controlling a motor speed of the flow generator, the controller comprising: receiving a pressure variable from a pressure sensor at a first flow rate; determining whether a possible leak condition is met based on comparing the received pressure variable to a first threshold, the first threshold being indicative of the possible leak condition; If a possible leak condition is met, increasing a motor speed of the flow generator to generate a second flow rate for the gas flow; receiving an updated pressure variable at a second flow rate; determining whether a possible leak condition, a no leak condition, or a certain leak condition is met by comparing the updated pressure variable to a first threshold and / or a second threshold, the second threshold representing a certain leak condition; If at the second flow rate the potential leak condition is met again, successively increasing the flow generator motor speed in discrete increments to increase the flow rate of gas at discrete intervals, and again comparing the updated pressure variable to the first and / or second thresholds after each discrete increment until either a confirmed leak condition or a no leak condition is met; A controller configured to: The present invention relates to a breathing apparatus comprising:

[0098] In one configuration, the disinfection kit or assembly includes a disinfection tube and a filter, the disinfection tube removably connected in the flow path in place of the removed humidification chamber, thereby fluidly connecting the gas outlet associated with the flow generator to a main gas outlet component of the device that connects to the patient circuit, and the filter removably connected to an open port of the main gas outlet. By way of example, the filter may be a filter component. In one example, the filter may be a filter cap or a cap with a filter, where the filter cap or cap engages with, in or over the open port of the main gas outlet.

[0099] In one configuration, the main gas outlet component of the apparatus includes an elbow conduit, a sterilization tube connected to a first end of the elbow conduit, and a filter connected to a second end of the elbow conduit such that during sterilization mode operation, gas flow from the flow generator flows through the sterilization tube, the elbow conduit, and out the filter to the atmosphere.

[0100] In one configuration, the first and / or second thresholds are configured to detect a leak condition in the flow path during disinfection mode operation that indicates or represents that a filter of the disinfection kit or assembly has been removed, is missing, or has at least partially fallen out of the main gas outlet.

[0101] In one configuration, a leak condition represents a component of the disinfection kit or assembly being removed or disconnected from the flow path.

[0102] In one configuration, the disinfection kit or assembly comprises an ozone module that can be coupled to the respiratory apparatus. The leak detection method can be configured to detect the removal or misconnection of the ozone module that is part of the disinfection kit. The ozone module can be configured to pump ozone gas through the respiratory apparatus flow path to disinfect the flow path. The ozone module may be required to be used for a set period of time. The described leak detection method is configured to detect the removal of the disinfection module (i.e., the ozone module) before the required time, thereby triggering an appropriate alarm.

[0103] In one aspect, the present disclosure provides a respiratory apparatus configured to provide a flow of gas to a user for respiratory therapy, the apparatus comprising: a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus to a gas outlet of the breathing apparatus; a humidifier operable to heat and humidify a gas flow, the humidifier including a removable humidification chamber in a flow path; a flow sensor configured to sense a flow rate of the gas flow in the flow path; a controller operatively connected to the flow generator and operable to control a flow rate of the gas flow by controlling a motor speed of the flow generator, the controller comprising: receiving or calculating a flow variable indicative of or representative of a flow rate of the gas flow sensed by the flow sensor; initiating a first stage leak assessment including comparing the flow variable to a first leak threshold, the first leak threshold indicating a possible leak condition; initiating a second stage of leak assessment when the flow variable exceeds the first leak threshold, thereby indicating a possible leak, the second stage of leak assessment comprising: increasing a flow generator motor speed from a current motor speed to a higher motor speed; comparing the new flow rate variable at the higher motor speed to a first leak threshold and a second leak threshold, the second leak threshold being indicative of a confirmed leak condition; generating a leak alarm and terminating the second stage of leak evaluation if the new flow variable exceeds a second leak threshold, thereby confirming the potential leak as a definite leak; or terminating the second stage of leak evaluation without generating an alarm if the new flow rate variable falls below the first leak threshold and the second leak threshold, thereby determining the potential leak as no leak; or repeating the second stage leak assessment at one or more higher motor speeds until a possible leak is confirmed or determined to be no leak; and a controller configured to execute a leak detection process to detect leaks in the flow path by The present invention relates to a breathing apparatus comprising:

[0104] In another aspect, the present disclosure provides a respiratory apparatus configured to provide a flow of gas to a user for respiratory therapy, the apparatus comprising: a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus to a gas outlet of the breathing apparatus; a humidifier operable to heat and humidify a gas flow, the humidifier including a removable humidification chamber in a flow path; a flow sensor configured to sense a flow rate of the gas flow in the flow path; a controller operatively connected to the flow generator and operable to control a flow rate of the gas flow by controlling a motor speed of the flow generator, the controller comprising: receiving or calculating a flow variable indicative of or representative of a flow rate of the gas flow sensed by the flow sensor at a first flow rate; determining whether a possible leak condition is met based on comparing the received flow variable to a first threshold, the first threshold being indicative of the possible leak condition; If a possible leak condition is met, increasing a motor speed of the flow generator to generate a second flow rate for the gas flow; receiving an updated flow rate variable at a second flow rate; determining whether a possible leak condition, a no leak condition, or a certain leak condition is met by comparing the updated flow rate variable to a first threshold and / or a second threshold, the second threshold representing a certain leak condition; If at the second flow rate the potential leak condition is met again, successively increasing the flow generator motor speed in discrete increments to increase the flow rate of the gas at discrete intervals, and again comparing the updated flow rate variable to the first and / or second threshold values ​​after each discrete increment until either a confirmed leak condition or a no leak condition is met; A controller configured to: The present invention relates to a breathing apparatus comprising:

[0105] In another aspect, the present disclosure provides a respiratory apparatus configured to provide a flow of gas to a user for respiratory therapy, the apparatus comprising: a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus to a gas outlet of the breathing apparatus; a humidifier operable to heat and humidify a gas flow, the humidifier including a removable humidification chamber in a flow path; a flow sensor configured to sense a flow rate of the gas flow in the flow path; a controller operatively connected to the flow generator and operable to control a flow rate of the gas flow by controlling a motor speed of the flow generator, the controller comprising: controlling a flow generator or a flow generator motor speed to deliver a flow of gas at a configurable user-set or pre-set flow rate during normal operation; receiving a flow variable representative of or indicative of a flow rate of the gas stream; Continue normal operation if the flow variable falls below the leak threshold, thereby indicating that no leak has been detected; or if the flow variable exceeds a leak threshold, indicating a possible leak has been detected, increasing or ramping up a motor speed or set flow rate of the flow generator by a predetermined or dynamically determined increment and receiving an updated flow variable with the new increased motor speed or increased set flow rate; generating an alarm and / or freezing the motor speed if the updated flow variable exceeds a leak threshold, thereby confirming a potential leak as a leak; or if the flow variable falls below the leak threshold, thereby determining that the potential leak is not a leak, returning to normal operation of the flow generator at the original user set flow rate; A controller configured to: The present invention relates to a breathing apparatus comprising:

[0106] In one aspect, the present disclosure provides a respiratory apparatus configured to provide a flow of gas to a user for respiratory therapy, the apparatus comprising: a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus to a gas outlet of the breathing apparatus; a humidifier operable to heat and humidify a gas flow, the humidifier including a removable humidification chamber in a flow path and a heater plate operable to heat the humidification chamber; a pressure sensor configured to generate a pressure variable representative of a sensed pressure characteristic of the flow of gas in the flow passage; a controller operatively connected to the flow generator and operable to control a flow rate of the gas flow by controlling a motor speed of the flow generator, the controller comprising: initiating a first stage leak assessment including comparing the pressure variable to a leak threshold, the leak threshold representing a possible leak condition; initiating a second stage leak assessment when the pressure variable falls below the leak threshold, thereby indicating a possible leak, the second stage leak assessment comprising: initiating a heater plate check process by applying power or a temperature process to a heater plate of the humidifier and evaluating a heating rate or / and cooling rate of the heater plate against one or more thresholds based on a temperature sensor of or associated with the heater plate, thereby determining the presence or absence of a humidification chamber in thermal contact with the heater plate; generating a leak alarm and terminating the second stage leak evaluation if the heater plate check determines that the humidification chamber is absent, thereby confirming the possible leak as a definite leak; or if the heater plate check determines that a humidification chamber is present, thereby determining the potential leak as no leak, terminating the second stage leak evaluation without generating an alarm; and a controller configured to execute a leak detection process to detect leaks in the flow path by The present invention relates to a breathing apparatus comprising:

[0107] In one aspect, the present disclosure provides a respiratory apparatus configured to provide a flow of gas to a user for respiratory therapy, the apparatus comprising: a motor-driven flow generator operable to generate a flow of gas; a flow path for the flow of gas through the breathing apparatus to a gas outlet of the breathing apparatus; a humidifier operable to heat and humidify a gas flow, the humidifier including a removable humidification chamber in a flow path and a heater plate operable to heat the humidification chamber; a flow sensor configured to sense a flow rate of the gas flow in the flow path; a controller operatively connected to the flow generator and operable to control a flow rate of the gas flow by controlling a motor speed of the flow generator, the controller comprising: initiating a first stage leak assessment including comparing a flow variable indicative of or representative of a flow rate of the gas flow to a leak threshold, the leak threshold being indicative of a possible leak condition; initiating a second stage leak assessment when the flow variable exceeds a leak threshold, thereby indicating a possible leak, the second stage leak assessment comprising: initiating a heater plate check process by applying power or a temperature process to a heater plate of the humidifier and evaluating a heating rate or / and cooling rate of the heater plate against one or more thresholds based on a temperature sensor of or associated with the heater plate, thereby determining the presence or absence of a humidification chamber in thermal contact with the heater plate; generating a leak alarm and terminating the second stage leak evaluation if the heater plate check determines that the humidification chamber is absent, thereby confirming the possible leak as a definite leak; or if the heater plate check determines that a humidification chamber is present, thereby determining the potential leak as no leak, terminating the second stage leak evaluation without generating an alarm; and a controller configured to execute a leak detection process to detect leaks in the flow path by The present invention relates to a breathing apparatus comprising:

[0108] These and other features, aspects, and advantages of the present disclosure will be described with reference to drawings of several embodiments, which are intended to illustrate several embodiments and are not intended to limit the present disclosure. [Brief description of the drawings]

[0109] [Figure 1] 1 illustrates generally a respiratory system configured to provide respiratory therapy to a patient. [Diagram 2] FIG. 1 is a front view of an example breathing apparatus with the humidification chamber in place and the handle / lever in the raised position. [Diagram 3] FIG. 3 is a top view corresponding to FIG. 2. [Figure 4] FIG. 3 is a right side view corresponding to FIG. 2. [Diagram 5] FIG. 3 is a left side view corresponding to FIG. 2. [Figure 6] FIG. 3 is a rear view corresponding to FIG. 2. [Figure 7] FIG. 3 is a front left perspective view corresponding to FIG. 2. [Figure 8] FIG. 3 is a front right perspective view corresponding to FIG. 2. [Figure 9] FIG. 3 is a bottom view corresponding to FIG. 2. [Figure 10] 1 shows an example of a respiratory apparatus air and oxygen inlet arrangement configuration; [Figure 11] 1 shows another example of an air and oxygen inlet arrangement for a breathing apparatus. [Figure 12] FIG. 12 is a cross-sectional view showing further details of the air and oxygen inlet arrangement of FIG. [Figure 13] FIG. 12 is another cross-sectional view showing further details of the air and oxygen inlet arrangement of FIG. [Figure 14] FIG. 12 is a longitudinal section showing further details of the air and oxygen inlet arrangement of FIG. [Figure 15] FIG. 2 is an exploded view of upper and lower chassis components of the main housing of the respiratory apparatus. [Figure 16]FIG. 1 is a front left perspective view of the lower chassis of the main housing showing the housing that receives the motor / sensor module subassembly. [Figure 17] FIG. 1 is a first underside perspective view of the main housing of the respiratory apparatus showing a recess within the housing for the motor / sensor module subassembly. [Figure 18] FIG. 13 is a second underside perspective view of the main housing of the respiratory apparatus showing the recess for the motor / sensor module subassembly. [Figure 19A] A block diagram of a control system that interacts with and / or provides control and direction to components of the respiratory system is shown. [Figure 19B] 1 illustrates a block diagram of an example controller. [Figure 20] FIG. 2 shows a block diagram of the motor and sensor module. [Figure 21] 1 illustrates a sensing chamber of an example motor and sensor module. [Figure 22] 1 shows a schematic flow diagram of a leak detection algorithm according to one embodiment. [Diagram 23] 1 shows a detailed flow diagram of one embodiment of a leak detection algorithm based on a leak pressure threshold during therapy or drying mode of the respiratory apparatus. [Figure 24A] 24 shows a graph of pressure versus flow rate, illustrating examples of leak thresholds associated with the leak detection algorithm of FIG. 23 and data associated with normal operation and leaks, according to one embodiment. [Figure 24B] 24B shows another version of the graph of FIG. 24A, showing leakage thresholds for normal operation and without leakage data. [Figure 24C] 24A shows a close-up of the graph of FIG. 24A illustrating particular leak threshold lines associated with an embodiment of the leak detection algorithm in scenarios of multiple iterations (A-C) of the algorithm in scenarios where no leaks are detected and the device is operating normally. [Figure 24D] A graph is shown in FIG. 24C demonstrating possible updates or modifications to the leak threshold line following a determination of normal operation where no leak is detected. [Figure 24E] A close-up of the graph of FIG. 24a shows particular leak threshold lines associated with an implementation of the leak detection algorithm in a scenario where the device is operating with a leak (e.g., chamber out) through multiple iterations of the algorithm (A, B) and subsequent iterations after the leak has been cleared (C, D, E). [Figure 25A] 3 shows a schematic example of a respiratory apparatus of the type shown in FIG. 2 with a disinfection kit installed and operating in disinfection mode, according to one embodiment. [Figure 25B] FIG. 13 shows a detailed flow diagram of another embodiment of a leak detection algorithm, based on a leak pressure threshold, for disinfection mode of the respiratory apparatus. [Figure 25C] 25B shows a graph of pressure versus flow rate, illustrating example leak thresholds associated with the leak detection algorithm of FIG. 25A for disinfection mode, and data regarding normal operation and leaks for disinfection mode, according to one embodiment. [Figure 26] FIG. 13 shows a flow diagram of an embodiment of a block detection algorithm for a disinfection mode of a respiratory apparatus according to an embodiment. [Figure 27A] 1 shows a detailed flow diagram of another embodiment of a leak detection algorithm for a respiratory apparatus, based on a leak flow threshold. [Figure 27B] 27B shows a graph of motor speed versus flow rate, illustrating examples of leak thresholds associated with the leak detection algorithm of FIG. 27A and data associated with normal operation and leaks, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0110] Several examples are described below, but those skilled in the art will appreciate that the disclosure extends beyond the specifically disclosed examples and / or uses, and obvious variations and equivalents thereof. Thus, it is not intended that the scope of the disclosure disclosed herein should be limited by any of the specific examples described below.

[0111] 1. Determining leaks in the flow path of a breathing apparatus configured as a non-sealed system The leak detection algorithms of the present disclosure are applicable to a variety of respiratory devices, particularly non-sealed systems operable or configurable to provide high-flow therapy through a non-sealed interface, such as a nasal cannula, which are inherently prone to leaks, i.e., due to the non-sealed patient interface.

[0112] In one embodiment, the leak detection algorithm is configured to detect one or more predetermined types of leaks in the flow path.

[0113] In one configuration, the leak detection algorithm is configured to detect a leak in the flow path caused by removal or disconnection (either completely or partially) of the humidification chamber from the flow path.

[0114] In other configurations, the leak detection algorithm may be configured to detect any other significant leaks along the flow path, such as coupling or connection leaks within the flow path of the respiratory apparatus or between components along the flow path.

[0115] In other configurations, the leak detection algorithm may be configured to detect leaks at the outlet of the device, for example, by detecting leaks caused by removal or disconnection (whether complete or partial) of the patient circuit (e.g., a conduit or tube) from the gas outlet of the device.

[0116] In some configurations, the leak detection algorithm may be configured to monitor for one type of leak, or may be configured to monitor or detect one or more different types of leaks, either simultaneously, or one at a time, periodically or continuously.

[0117] In some configurations, the leak detection algorithm may be configured to monitor for a particular or predetermined type of leak during one or more different operational modes of the respiratory apparatus. In one example, the leak detection algorithm may be configured to operate during a therapeutic mode, when a flow of gas is being delivered to a user or patient for respiratory therapy. In another example, the leak detection algorithm may be configured to operate during a non-therapeutic mode, such as, but not limited to, a drying mode and a disinfection mode. The type of leak that is detected may depend on the operational mode of the respiratory apparatus.

[0118] In one embodiment, the leak detection algorithm is configured to detect removal or disconnection of the humidification chamber from the humidifier of the respiratory device. The humidifier is a critical function and is required when providing high nasal flow. Humidification provides comfort to the patient and helps maintain the health of the patient's airway. Humidification can also improve patient comfort and therefore can help improve patient compliance with high flow therapy.

[0119] In one configuration, the leak detection algorithm is capable of operating continuously over the entire range of therapeutic operating flow rates of the device and with any size patient interface, such as both an adult interface and a neonatal or pediatric interface.

[0120] In non-sealed systems, such as respiratory devices that deliver high nasal flows, at low flow rates it may be difficult for the system to accurately or easily identify when the humidification chamber has been removed from the humidifier or is not in the flow path based on monitoring the characteristics of the gas flow. When monitoring the characteristics of the gas flow to determine a leak, such as a disconnected or removed humidification chamber, there is a possibility of false positives. At low flow rates, humidity is still important to patient care, particularly for pediatric or neonatal patients, and therefore accurate or reliable detection of removal of the humidification chamber is important.

[0121] In one embodiment, the respiratory device can provide continuous control over its operating flow rate range of 0 L / min to 80 L / min. In one embodiment, the respiratory device can selectively operate with multiple interfaces, such as, but not limited to, small, medium, and large adult cannulas and small, medium, and large pediatric cannulas. In one embodiment, the respiratory device is operable to provide flow therapy to a variety of patients, e.g., adult, pediatric, or neonatal patients, in a single mode of operation in which the flow rate setting is adjusted for a given patient. In one embodiment, a leak threshold is provided for the leak detection algorithm that is valid over the entire operating flow rate range such that the same leak detection algorithm can be continuously operated regardless of the type of patient using the device, and / or the target flow rate setting, and / or the type or size of patient interface (e.g., cannula) being used. For example, the leak detection algorithm can function over multiple flow rate ranges and with multiple different sizes or types of patient interfaces without changing the leak threshold or leak threshold function in some embodiments.

[0122] As explained above, nasal high flow therapy delivered from a respiratory device is highly prone to leaks. Nasal high flow systems are not sealed and are low pressure systems. Leak detection, such as chamber disconnection detection, needs to be more sensitive to small changes in flow rate and pressure in the flow of gas generated by the system in the flow path. Typically, accurate leak detection is difficult, especially at low flow ranges, as the alarm conditions of a non-sealed system converge with normal operating conditions. For example, when detecting leaks at low flow rates, such as, without limitation, at therapeutic flow rates for pediatric patients (e.g., below 15 L / min, more specifically below 10 L / min), the likelihood of false positives is high. At these low flow ranges, the flow rate and pressure conditions between normal operation and operation with a leak (e.g., humidification chamber is removed) converge. This makes it difficult to distinguish between normal operation and when a leak occurs.

[0123] What is needed is a leak detection method that is robust, acts quickly, and is capable of determining a leak condition under low flow conditions with minimal or reduced false conditions.

[0124] 2. Overview of breathing apparatus examples The methods and processes for determining leaks are described with respect to an example respiratory device 10 configured or operable to provide nasal high flow therapy via a non-sealing patient interface, which is intended as a non-limiting example, and it will be understood that the leak detection methods and processes may be applied to other respiratory devices and / or other modes of operation and / or modes of therapy delivered by such devices.

[0125] FIG. 1 shows a schematic diagram of an example respiratory apparatus 10. The respiratory apparatus 10 may include a main device housing 100. The main device housing 100 may include a flow generator 11, which may be in the form of a motor / impeller arrangement, a humidifier 12, a controller 13, and a user interface 14. The user interface 14 may include a display and an input device, such as a button, a touch screen, or a combination of a touch screen and buttons. The controller 13 may include one or more hardware and / or software processors and may be configured or programmed to control components of the system, such as, but not limited to, operating the flow generator 11 to generate a flow of gas for delivery to a patient, operating the humidifier 12 to humidify and / or heat the gas flow, receiving user input from the user interface 14 for reconfiguration and / or user-defined operation of the respiratory apparatus 10, and outputting information to a user (e.g., on a display). The user may be a patient, a medical professional, or the like.

[0126] 1, a patient respiratory conduit 16 may be connected to a gas outlet 21 in the main device housing 100 of the respiratory apparatus 10, and to a patient interface 17, such as a non-sealing interface, such as a nasal cannula having a manifold 19 and nasal prongs 18. The patient respiratory conduit 16 may also be a tracheostomy interface, or other non-sealing interface.

[0127] The gas flow may be generated by a flow generator 11 and may be humidified before delivery to the patient through a patient interface 17 via a patient breathing conduit 16. The controller 13 may control the flow generator 11 to generate a gas flow at a desired flow rate and / or control one or more valves to control the mixture of air with oxygen or other breathable gas. The controller 13 may control a heating element in or associated with the humidification chamber 12 to heat the gas to a desired temperature to achieve a desired level of temperature and / or humidity for delivery to the patient. The patient breathing conduit 16 may have a heating element 16a, such as a heater wire, that heats the gas flow passing through it towards the patient. The heating element 16a may also be controlled by the controller 13.

[0128] The humidifier 12 of the device is configured to couple or introduce humidity into the gas stream. Various humidifier 12 configurations can be employed. In one configuration, the humidifier 12 can include a humidification chamber that is removable. For example, the humidification chamber can be partially or entirely removed or disconnected from the flow path and / or the device. By way of example, the humidification chamber can be removed for, for example, refilling, cleaning, replacement and / or repair. In one configuration, the humidification chamber can be received and held by or within a humidification compartment or divider of the device, or can be otherwise coupled on or within the housing of the device.

[0129] The humidification chamber of the humidifier 12 may be provided with a gas inlet and a gas outlet to allow connection to a gas flow path of the apparatus, for example, a flow of gas from the flow generator 11 may be received into the humidification chamber via its gas inlet, and after being heated and / or humidified, may exit the chamber via its gas outlet.

[0130] The humidification chamber contains a volume of liquid, typically water, etc. In operation, the liquid in the humidification chamber is controllably heated by one or more heaters or heating elements associated with the chamber to generate water vapor or steam, increasing the humidity of gases flowing through the chamber.

[0131] In one configuration, the humidifier is a pass-over humidifier. In another configuration, the humidifier may be a non-pass-over humidifier. The leak detection algorithm may be configured to detect the removal or disconnection of the humidification chamber from the flow path of the device, whether the humidifier of the device is a pass-over or non-pass-over humidifier.

[0132] In one configuration, the humidifier can include a heater plate, for example, associated with or within the humidification bay in which the chamber rests for heating. The base or other surface of the chamber can be provided with a heat transfer surface, for example, a metal insert, plate, etc., that interacts with or engages with the heater plate of the humidifier.

[0133] In another configuration, the humidification chamber may include an internal heater or heater element within or within the chamber, which may be integrally attached or provided within the chamber, or which may be removable from the chamber.

[0134] The humidification chamber may be of any suitable shape and / or size. The location, number, size and / or shape of the gas inlet and gas outlet of the chamber may be varied as needed. In one configuration, the humidification chamber may have a base surface, one or more side walls extending upwardly from the base surface, and a top surface or top surface. In one configuration, the gas inlet and gas outlet may be positioned on the same side of the chamber. In another configuration, the gas inlet and gas outlet may be on different sides of the chamber, such as on opposite sides or positions, or in different positions.

[0135] In some configurations, the gas inlet and the gas outlet can have parallel flow axes. In some configurations, the gas inlet and the gas outlet can be positioned at the same height above the chamber.

[0136] The system 10 may use ultrasonic transducers, flow sensors such as thermistor flow sensors, pressure sensors, temperature sensors, humidity sensors, or other sensors in communication with the controller 13 to monitor characteristics of the gas flow and / or operate the system 10 in a manner to provide a suitable therapy. The gas flow characteristics may include gas concentration, flow rate, pressure, temperature, humidity, etc. Sensors 3a, 3b, 3c, 20, 25, such as pressure, temperature, humidity and / or flow sensors, may be located at various locations on the main device housing 100, the patient conduit 16 and / or the patient interface 17. The controller 13 may receive output from the sensors to help operate the respiratory apparatus 10 in a manner to provide a suitable therapy, such as to determine a suitable target temperature, flow rate and / or pressure of the gas flow. Providing a suitable therapy may include meeting the inhalation demands of the patient. In the illustrated embodiment, the sensors are positioned within the housing of the apparatus.

[0137] The device 10 may include a wireless data transmitter and / or receiver, or transceiver 15, to enable the controller 13 to wirelessly receive data signals 8 from the motion sensors and / or control various components of the system 10. Additionally or alternatively, the data transmitter and / or receiver 15 may send data to a remote server or enable remote control of the system 10. The system 10 may include a wired connection, e.g., using a cable or wire, to enable the controller 13 to receive data signals 8 from the motion sensors and / or control various components of the device 10. The device 10 may include one or more wireless communication modules. For example, the device may include a cellular communication module, e.g., a 3G, 4G, or 5G module. The module 15 may be a modem that enables the device to communicate with a remote server using a suitable communication network. The communication may be two-way communication between the device and the server or other remote system. The device 10 may include other wireless communication modules, e.g., a Bluetooth module and / or a Wi-Fi module. The Bluetooth and / or WiFi modules allow the device to transmit information wirelessly to another device, such as a smartphone or tablet, or to operate via a LAN (Local Area Network).

[0138] The respiratory device 10 may include a high-flow therapy device. High-flow therapy as discussed herein is intended to be given its typical ordinary meaning as understood by those skilled in the art, and generally refers to a respiratory system that delivers a targeted flow of humidified respiratory gas through an intentionally unsealed patient interface at a flow rate generally intended to meet or exceed the inhalation flow rate of the user. Exemplary patient interfaces include, but are not limited to, nasal or tracheal patient interfaces. Typical flow rates for adults often range, but are not limited to, from about 15 liters / minute to about 60 liters / minute or more. Typical flow rates for pediatric users (such as neonates, infants, and children) often range, but are not limited to, from about 1 liter / minute / kg of user body weight to about 3 liters / minute / kg of user body weight or more.

[0139] High flow therapy may also optionally include administration of mixed gas compositions including supplemental oxygen and / or therapeutic agents.

[0140] High-flow therapy is often referred to as nasal high flow (NHF), humidified high flow nasal cannula (HHFNC), high flow nasal oxygen (HFNO), high flow therapy (HFT), and tracheal high flow (THF), among other common names. For example, in some configurations, for an adult patient, "high flow therapy" may refer to delivering gas to the patient at a flow rate of about 10 liters per minute (10 LPM) or greater, such as about 10 LPM to about 100 LPM, or about 15 LPM to about 95 LPM, or about 20 LPM to about 90 LPM, or about 25 LPM to about 85 LPM, or about 30 LPM to about 80 LPM, or about 35 LPM to about 75 LPM, or about 40 LPM to about 70 LPM, or about 45 LPM to about 65 LPM, or about 50 LPM to about 60 LPM. In some configurations, for neonatal, infant or pediatric patients, "high flow therapy" may refer to delivering gas to the patient at a flow rate of greater than 1 LPM, such as from about 1 LPM to about 25 LPM, or from about 2 LPM to about 25 LPM, or from about 2 LPM to about 5 LPM, or from about 5 LPM to about 25 LPM, or from about 5 LPM to about 10 LPM, or from about 10 LPM to about 25 LPM, or from about 10 LPM to about 20 LPM, or from about 10 LPM to about 15 LPM, or from about 20 LPM to about 25 LPM. High flow therapy devices for adult, neonatal, infant or pediatric patients may deliver gas to the patient at a flow rate of from about 1 LPM to about 100 LPM, or in any of the subranges outlined above.

[0141] High-flow therapy can be effective in meeting or exceeding the inspiratory demand of a patient, increasing the patient's oxygenation, and / or decreasing the work of breathing. Additionally, high-flow therapy can create a flushing effect in the nasopharynx, causing the anatomical dead space of the upper airway to be flushed with a high inflow gas flow. This flushing effect can provide a reservoir of fresh gas available with every breath while minimizing rebreathing of carbon dioxide, nitrogen, etc. High-flow therapy can also increase the patient's exhalation time due to pressure during exhalation, which can decrease the patient's respiratory rate.

[0142] The patient interface used in high-flow therapy may be a non-sealing interface to prevent barotrauma, which may include tissue damage to the lungs or other organs of the patient's respiratory system due to pressure differentials relative to atmospheric pressure. The patient interface may be a nasal cannula with a manifold and nasal prongs, and / or a non-sealing tracheotomy interface, or other suitable type of patient interface.

[0143] 2-18 show an example respiratory apparatus 10 having a main housing 100. The main housing 100 has a main housing upper chassis 102 and a main housing lower chassis 202. The main housing upper chassis 102 has a peripheral wall arrangement 106 (see FIG. 15). The peripheral wall arrangement defines a humidifier or humidification chamber bay 108 that receives a removable humidification chamber 300. The removable humidification chamber 300 contains a suitable liquid, such as water, for humidifying gases that can be delivered to a patient.

[0144] In the illustrated form, the perimeter wall arrangement 106 of the main housing top chassis 102 may include a substantially vertical left outer wall 110 oriented in the fore-aft direction of the main housing 100, a substantially vertical left inner wall 112 oriented in the fore-aft direction of the main housing 100, and an interconnecting wall 114 extending between and interconnecting upper ends of the left outer wall 110 and the left inner wall 112. The main housing top chassis 102 may further include a substantially vertical right outer wall 116 oriented in the fore-aft direction of the main housing 100, a substantially vertical right inner wall 118 oriented in the fore-aft direction of the main housing 100, and an interconnecting wall 120 extending between and interconnecting upper ends of the right outer wall 116 and the right inner wall 118. The interconnecting walls 114, 120 are angled toward the respective outer edges of the main housing 100, but may alternatively be substantially horizontal or inwardly slanted.

[0145] The main housing top chassis 102 may further include a substantially vertical rear exterior wall 122. The top of the main housing top chassis 102 may include a forwardly sloping surface 124. The surface 124 may have a recess 126 that receives the display and user interface module 14. The display may be configured to display the characteristics of the detected gas in real time. The system may display a patient detection status of the patient interface. If no patient is detected, the controller may not output or may stop outputting to display the respiration value and / or other parameters. The controller may also optionally output to display a message that no patient is detected in block 2708. One example of a message may be a "--" icon. An interconnecting wall 128 may extend between and interconnect the top end of the rear exterior wall 122 and the rear edge of the surface 124.

[0146] A substantially vertical wall portion 130 may extend downwardly from a front end of the surface 124. A substantially horizontal wall portion 132 may extend forwardly from a lower end of the wall portion 130 to form a shelf. A substantially vertical wall portion 134 may extend downwardly from a front end of the wall portion 132 to terminate at a substantially horizontal floor portion 136 of the humidification chamber bay 108. The left inner wall 112, the right inner wall 118, the wall portion 134 and the floor portion 136 may collectively define the humidification chamber bay 108. The floor portion 136 of the humidification chamber bay 108 may have a recess 138 for receiving a heater arrangement, such as a heater plate 140 or other suitable heating element, that heats liquid within the humidification chamber 300 for use during the humidification process.

[0147] The main housing lower chassis 202 may be attachable to the upper chassis 102 by either suitable fasteners or an integrated attachment mechanism, such as, for example, clips. The main housing lower chassis 202 may include a substantially vertical left outer wall 210 oriented in the fore-aft direction of the main housing 100 and continuous with the left outer wall 110 of the upper chassis 102, and a substantially vertical right outer wall 216 oriented in the fore-aft direction of the main housing 100 and continuous with the right outer wall 116 of the upper chassis 102. The main housing lower chassis 202 may further include a substantially vertical rear outer wall 222 continuous with the rear outer wall 122 of the upper chassis 102.

[0148] The lower housing chassis 202 can have a lip 242 that is continuous with the lip 142 of the upper housing chassis 102 and also forms part of a recess that receives the handle portion 506 of the lever 500. The lower lip 242 can include a forwardly directed protrusion 243 that acts as a retainer for the handle portion 506 of the lever 500. In place of the lever 500, the system can include a spring-loaded guard to retain the humidification chamber 300 within the humidification chamber bay 108.

[0149] The underside of the lower housing chassis 202 can include a bottom wall 230. Each of the interconnecting walls 214, 220, 228 can extend between and interconnect the substantially vertical walls 210, 216, 222 and the bottom wall 230. The bottom wall 230 can include a grill 232 with a number of apertures that allow for the drainage of liquid if it leaks from the humidification chamber 300 (e.g., from a spill). The bottom wall 230 can further include an elongated front-to-rear oriented slot 234. The slot 234 can allow for the drainage of liquid if it leaks from the humidification chamber 300 without the liquid entering the electronics housing. In the illustrated configuration, the slot 234 can be wide and elongated relative to the apertures of the grill 232 to maximize the drainage of liquid.

[0150] As shown in FIGS. 17 and 18, the lower chassis 202 can have a motor recess 250 for receiving a motor and sensor module. The motor and sensor module can be non-removable from the main housing 100. As shown in FIGS. 17 and 18, the motor and sensor module can be removable from the main housing 100. The bottom wall 230 can have a recess opening 251 adjacent its rear edge for receiving the motor / sensor module. A continuous, gas impermeable, uninterrupted peripheral wall 252 can be integrally formed with the bottom wall 230 of the lower chassis 202 and extend upwardly from a periphery of the opening 251. A rear portion 254 of the peripheral wall 252 has a first height and a front portion 256 of the peripheral wall 252 has a second height greater than the first height. The rear portion 254 of the peripheral wall 252 terminates in a substantially horizontal step 258 which further terminates in an upper secondary rear portion 260 of the peripheral wall 252. The forward portion 256 and upper secondary rear portion 260 of the peripheral wall 252 terminate in a ceiling 262. All of the walls and ceiling 262 may be continuous, gas impermeable, and uninterrupted except for the gas flow passages. Thus, the entire motor recess 250 may be gas impermeable and uninterrupted except for the gas flow passages.

[0151] The motor and sensor module may be insertable into the recess 250 and mountable to the lower chassis 202. When the motor and sensor module is inserted into the lower chassis 202, the gas flow tube 264 may extend through the downward extension tube 133 and be sealed by a soft seal.

[0152] The humidification chamber 300 may be fluidly coupled to the device 10 with a linear slide-on motion from a position at the front of the housing 100 toward the rear of the housing 100 toward the rear of the housing 100 toward the rear of the housing 100. A gas outlet port 322 may be in fluid communication with the motor.

[0153] 8 may include a removable L-shaped elbow or "elbow conduit," generally designated 320. The removable elbow may further include a patient outlet port 344 that connects to the patient conduit 16 for delivering gas to the patient interface. The gas outlet port 322, the gas inlet port 340, and the patient outlet port 344 may each have a soft seal, such as an O-ring seal or a T-seal, to provide a sealed gas passageway between the device 10, the humidification chamber 300, and the patient conduit 16.

[0154] The humidification chamber gas inlet port 306 may be complementary to the gas outlet port 322, and the humidification chamber gas outlet port 308 may be complementary to the gas inlet port 340. The axes of the ports may be parallel to one another, allowing the humidification chamber 300 to be inserted into the chamber bay 108 with a linear motion.

[0155] The respiratory apparatus may have an air and oxygen (or alternative auxiliary gas) inlet in fluid communication with the motor so that the motor can deliver air, oxygen (or alternative auxiliary gas) or a mixture thereof to the humidification chamber 300 and thereby to the patient. As shown in FIG. 10, the device may have a combined air / oxygen (or alternative auxiliary gas) inlet arrangement 350. This arrangement may include a combined air / oxygen port 352 into the housing 100, a filter 354, and a cover 356 having a hinge 358. Optionally, a gas tube may extend laterally or in another suitable direction and be in fluid communication with an oxygen (or alternative auxiliary gas) source. The port 352 may be fluidly coupled to the motor 402. For example, the port 352 may be coupled to the motor / sensor module 400 via a gas flow path between the port 352 and an inlet aperture or port in the motor and sensor module 400 that leads to the motor.

[0156] The device may have the arrangement shown in Figures 11-14 such that the blower can deliver air, oxygen (or alternative auxiliary gas) or a suitable mixture thereof to the humidification chamber 300 and thereby to the patient. This arrangement may include an air inlet 356' in the rear wall 222 of the lower chassis 202 of the housing 100. The air inlet 356' comprises a rigid plate having a suitable grill arrangement of apertures and / or slots. Sound deadening foam may be provided adjacent to the plate on the interior side of the plate. An air filter box 354' may be positioned internally of the main housing 100 adjacent to the air inlet 356', which may include an air outlet port 360 for delivering filtered air to the motor via the air inlet port 404 of the motor / sensor module 400. The air filter box 354' may include a filter configured to remove particulates (e.g., dust) and / or pathogens (e.g., viruses or bacteria) from the gas flow. A soft seal, such as an O-ring seal, may be provided between the air outlet port 360 and the air inlet port 404 to seal between the components. The device may include a separate oxygen inlet port 358' positioned adjacent one side of the housing 100 at its rear end for receiving oxygen from an oxygen source, such as a tank or a piped oxygen source. The oxygen inlet port 358' is in fluid communication with a valve 362. The valve 362 may preferably be a solenoid valve that allows control of the amount of oxygen added to the gas stream delivered to the humidification chamber 300. The oxygen port 358' and valve 362 may be used with other supplemental gases to control the addition of other supplemental gases to the gas stream. The other supplemental gases may include any one or more of a number of gases useful for gas therapy, including but not limited to heliox and nitric oxide.

[0157] As shown in Figures 13-16, the lower housing chassis 202 can include a suitable electronic circuit board, such as a sensing circuit board. The electronic circuit board can be positioned adjacent to each of the outer side walls 210, 216 of the lower housing chassis 202. The electronic circuit board can include or be in electrical communication with suitable electrical or electronic circuit components, such as, but not limited to, microprocessors, capacitors, resistors, diodes, operational amplifiers, comparators, and switches. Sensors can also be used in conjunction with the electronic board. Components of the electronic circuit board, such as, but not limited to, one or more microprocessors, can act as the controller 13 of the device.

[0158] One or both of the electronic circuit boards can be in electrical communication with the electrical components of the device 10, including the display unit and user interface 14, the motor, the valve 362 and the heater plate 140, to operate the motor to provide a desired flow rate of gas, to operate the humidification chamber 300 to humidify and heat the gas stream to an appropriate level, and to supply an appropriate amount of oxygen (or an appropriate amount of an alternative auxiliary gas) to the gas stream.

[0159] The electronic circuit board may be in electrical communication with a connector arrangement 274 that protrudes from the rear wall 122 of the upper housing chassis 102. The connector arrangement 274 may be coupled to an alarm, a pulse oximetry port, and / or other suitable accessories. The electronic circuit board may also be in electrical communication with an electrical connector 276, which may also be provided on the rear wall 122 of the upper housing chassis 102 to provide mains or battery power to the components of the device.

[0160] As mentioned above, operational sensors such as flow, temperature, humidity and / or pressure sensors may be located at various locations on the respiratory apparatus, patient breathing conduit 16 and / or cannula 17 as shown in Figure 1. The electronic circuit board may be in electrical communication with those sensors. Output from the sensors may be received by the controller 13 to help the controller 13 operate the respiratory apparatus 10 in a manner that provides optimal therapy including, for example, meeting inspiration demand. In the illustrated embodiment, the sensors are located on an electronic circuit board that is positioned within the housing. The sensors are enclosed within the housing.

[0161] As outlined above, electronic circuit boards and other electrical and electronic components can be pneumatically isolated from the gas flow path for added safety. The seal also prevents water ingress.

[0162] 2.1 Control system FIG. 19A shows a block diagram 900 of an example control system 920 (which may be the controller 13 of FIG. 1) that can detect a patient's condition and control the operation of the breathing system, including the gas source. The control system 920 can manage the flow rate of gas through the breathing system so that gas is delivered to the patient. For example, the control system 920 can increase or decrease the flow rate by controlling the motor speed output 930 of a blower (hereinafter also referred to as a "blower motor") or the valve output 932 in a mixer. The control system 920 can automatically determine a set value or an individualized value of the flow rate for a particular patient, as described below. The flow rate can be optimized by the control system 920 to increase patient comfort and improve treatment.

[0163] The control system 920 may also generate audio and / or display / visual outputs 938, 939. For example, a flow therapy device may include a display and / or speaker. The display may show the physician any warnings or alarms generated by the control system 920. The display may also show control parameters that the physician may adjust. For example, the control system 920 may automatically recommend a flow rate for a particular patient. The control system 920 may also determine the patient's respiratory status, including but not limited to generating a patient's respiratory rate, and transmit that to a display (this is described in more detail below).

[0164] The control system 920 can vary the heater control outputs to control one or more of the heating elements (e.g., to maintain a temperature set point of the gas delivered to the patient). The control system 920 can also vary the operation or duty cycle of the heating elements. The heater control outputs can include a heater plate control output 934 and a heated breathing tube control output 936.

[0165] The control system 920 can determine outputs 930-939 based on one or more received inputs 901-916. The inputs 901-916 can correspond to sensor measurements automatically received by the controller 600 (shown in FIG. 19B). The control system 920 can receive, from, but not limited to, a temperature sensor input 901, a flow sensor input 902, a motor speed input 903, a pressure sensor input 904, a gas fraction sensor input 905, a humidity sensor input 906, a pulse oximeter (e.g., SpO 2 ) sensor input 907, stored or user parameters 908, duty cycle or pulse width modulation (PWM) input 909, voltage input 910, current input 911, acoustic sensor input 912, power input 913, resistance input 914, CO 2Sensor inputs can be received, including sensor inputs 915 and / or spirometer inputs 916. The control system 920 can receive inputs from a user or parameter values ​​stored in memory 624 (shown in FIG. 19B). The control system 920 can dynamically adjust the flow rate to the patient over the course of the patient's treatment. The control system 920 can continuously sense system parameters and patient parameters. Those skilled in the art will appreciate based on the disclosure herein that any other suitable inputs and / or outputs can be used with the control system 920.

[0166] One or more pressure sensors In one configuration, the device can include one or more pressure sensors. The one or more pressure sensors can be provided to sense or measure a pressure characteristic of the gas flow in a flow path of the device and generate a respective pressure variable, such as a pressure sensor signal or data. The pressure sensors can include any type of suitable pressure sensor, including, but not limited to, a gauge pressure sensor and / or an absolute pressure sensor.

[0167] The gauge pressure sensor can be configured to sense the gauge pressure of the gas flow and generate a representative gauge pressure variable, such as a gauge pressure signal or pressure data. The gauge pressure may represent the pressure of the gas flow in the flow path referenced to or relative to atmospheric pressure. For example, the gauge pressure may represent the difference between the absolute pressure in the flow path and the absolute pressure in the housing (i.e., atmospheric or ambient pressure).

[0168] The absolute pressure sensor may be configured to sense the absolute pressure of the gas flow and generate a representative absolute pressure variable, such as an absolute pressure signal or pressure data, which may represent the pressure of the gas flow in the flow path referenced to or relative to a vacuum.

[0169] As will be appreciated by those skilled in the art, one or more pressure sensors configured to sense or measure pressure characteristics of a gas flow may be directly or at least partially immersed within a main or bulk flow path of the gas flow (e.g., the sensor may be part of or exposed to a sensor passage or sensor chamber that forms part of the main or bulk flow path), or directly or at least partially immersed within a secondary or sample flow path that is operatively or fluidly connected to the main or bulk flow path, or may be otherwise operatively or fluidly coupled or connected to the gas flow in the flow path.

[0170] A pressure sensor that senses a pressure characteristic of the gas flow may be mounted independently within the housing of the device and in electrical or other data communication with a controller or control system, or may be mounted or coupled to a sensor circuit board or other circuit board associated with the gas flow path. In one configuration, the pressure sensor may be positioned or configured to sense the pressure of the gas flow at a location along the flow path before (e.g., upstream of) the humidifier or humidification chamber. In another configuration, the pressure sensor may be positioned or configured to sense the pressure of the gas flow at a location along the flow path between a flow generator, e.g., a blower, and the humidifier chamber, e.g., between the blower outlet and the humidifier chamber inlet (i.e., downstream of the blower and upstream of the humidifier chamber).

[0171] One or more pressures may also be provided to sense other pressures associated with the device, such as the ambient environment in which the device is located. In one configuration, the device may be provided with an ambient pressure sensor configured to sense or measure the ambient or atmospheric pressure of the local ambient environment in which the device is located and generate a representative ambient pressure variable, such as an ambient pressure signal or pressure data. In one configuration, the ambient pressure sensor may be absolute, located or positioned on or in the housing and configured to sense the ambient or atmospheric pressure of the environment in which the device is located.

[0172] In one configuration, the leak detection algorithm can be configured to receive a gauge pressure signal or data from a gauge pressure sensor representative of a gauge pressure associated with the flow of gas in the flow passage.

[0173] In another configuration, the leak detection algorithm may be configured to receive a gauge pressure signal or data from a gauge pressure sensor that senses the flow of gas and an ambient pressure signal or data from an ambient pressure sensor. In such a configuration, the leak detection algorithm may be configured to utilize the ambient pressure data as an input to a correction algorithm, coefficient, or function that is applied to the sensed gauge pressure signal or data. For example, the correction algorithm, coefficient, or function may be configured to correct the sensed gauge pressure signal or data to account for the effect of changes in air density on the sensed gauge pressure signal or data. The leak detection algorithm may be configured to apply the correction algorithm, coefficient, or function to the incoming pressure sensor data and use the corrected gauge pressure signal or data in the remaining leak detection algorithm steps. In an alternative configuration, the gauge pressure signal or data may be pre-processed with a correction algorithm, coefficient, or function before being input to the leak detection algorithm, and the leak detection algorithm may receive the corrected gauge pressure signal or data.

[0174] 2.2 Controller FIG. 19B illustrates a block diagram of one embodiment of a controller 600 (which may be controller 13 of FIG. 1). The controller 600 may include programming instructions for detecting input conditions and controlling output states. The programming instructions may be stored in memory 624 of the controller 600. The programming instructions may correspond to the methods, processes and functions described herein. The programming instructions may be executed by one or more hardware processors 622 of the controller 600. The programming instructions may be implemented in C, C++, JAVA, or any other suitable programming language. Some or all of the portions of the programming instructions may be implemented in application specific circuitry 628, such as ASICs and FPGAs.

[0175] The controller 600 may also include circuitry 628 for receiving sensor signals. The controller 600 may further include a display 630 for communicating the status of the patient and the respiratory assistance system. The display 630 may also display warnings and / or other alerts. The display 630 may be configured to display the characteristics of the detected gas in real-time or otherwise. The controller 600 may also receive user input via a user interface, such as the display 630. The user interface may include buttons and / or dials. The user interface may include a touch screen.

[0176] 2.3 Motor and Sensor Module Any of the features of the respiratory system described herein may be combined with any of the sensor modules described herein, including, but not limited to, a humidification chamber, a flow generator, a user interface, a controller, and a patient respiratory conduit configured to connect a gas outlet of the respiratory system to a patient interface.

[0177] Figure 20 shows a block diagram of a motor and sensor module 2000 that can be received by the recess 250 of the respiratory device (shown in Figures 17 and 18). The motor and sensor module can include a blower 2001 that conveys room air for delivery to the patient. The blower 2001 can be a centrifugal blower.

[0178] One or more sensors (e.g., Hall effect sensors) may be used to measure the motor speed of the blower motor. The blower motor may include a brushless DC motor from which the motor speed may be measured without the use of a separate sensor. For example, during operation of the brushless DC motor, back EMF may be measured from a non-current carrying winding of the motor from which the motor position may be determined, and the motor position may be used to calculate the motor speed. In addition, a motor driver may be used to measure the motor current, which may be used along with the measured motor speed to calculate the motor torque. The blower motor may include a low inertia motor.

[0179] Room air can enter room air inlet 2002 and enter blower 2001 through inlet port 2003. Inlet port 2003 can include a valve 2004 through which pressurized gas can enter blower 2001. Valve 2004 can control the flow of oxygen to blower 2001. Valve 2004 can be any type of valve including a proportional valve or a binary valve. In some embodiments, the inlet port does not include a valve.

[0180] The blower 2001 can operate at motor speeds of greater than 1,000 RPM and less than 30,000 RPM, greater than 2,000 RPM and less than 21,000 RPM, or between any of the aforementioned values. The operation of the blower 2001 mixes the gas entering the blower 2001 through the inlet port 2003. Because mixing requires energy, the use of the blower 2001 as a mixer can reduce the pressure drop that would otherwise occur in a system with a separate mixer, such as a static mixer with baffles.

[0181] The mixed air may exit the blower 2001 through a conduit 2005 and enter a flow path 2006 in a sensor chamber 2007. A sensing circuit board with sensors 2008 may be positioned in the sensor chamber 2007 such that the sensing circuit board is at least partially immersed in the gas flow. At least some of the sensors 2008 on the sensing circuit board may be positioned in the gas flow to measure gas properties in the flow. After the gas passes through the flow path 2006 in the sensor chamber 2007, it may exit to a humidification chamber (2009).

[0182] Positioning the sensor 2008 downstream of the combined blower and mixer 2001 allows for more accurate measurements, such as measurements of gas fraction concentrations, including oxygen concentration, than systems that position the sensor upstream of the blower and / or mixer. Such positioning allows for repeatable flow profiles. Additionally, positioning the sensor downstream of the combined blower and mixer avoids the pressure drop that would otherwise occur if sensing were performed before the blower, since a separate mixer, such as a static mixer with baffles, would be required between the inlet and the sensing system. The mixer can cause a pressure drop before and after the mixer. Positioning the sensing after the blower allows the blower to be the mixer, as opposed to a static mixer that reduces pressure, whereas a blower increases pressure. Additionally, immersing at least a portion of the sensing circuit board and sensor 2008 in the flow path can improve the accuracy of the measurement because the sensor being immersed in the flow means that the sensor is exposed to the same conditions as the gas flow, such as temperature and pressure, and therefore is more likely to provide a better representation of the gas flow characteristics.

[0183] 21, gas exiting the blower can enter a flow path 402 in a sensor chamber 400, which can be positioned in the motor and sensor module and can be the sensor chamber 2007 of FIG. 20. The flow path 402 can have a curved shape. The flow path 402 can be configured to have a curved shape without sharp turns. The flow path 402 can have curved ends and straighter sections between them. A curved flow path shape can reduce the pressure drop of the gas flow without reducing the sensitivity of the flow measurement by partially coinciding the measurement area with the flow path to form the measurement portion of the flow path.

[0184] Within the sensor chamber 400, a sensing circuit board 404 with sensors such as acoustic transmitters and / or receivers, humidity sensors, temperature sensors, pressure sensors, thermistors, etc., may be positioned such that the sensing circuit board 404 is at least partially immersed in the flow path 402. Immersing at least a portion of the sensing circuit board and sensors in the flow path may improve the accuracy of the measurement because the sensors immersed in the flow path are more likely to be exposed to the same conditions as the gas flow, such as temperature and pressure, and therefore provide a better representation of the characteristics of the gas flow. After passing through the flow path 402 in the sensor chamber 400, the gas may exit to a humidification chamber. Alternatively, one or more of the pressure sensors may be provided on one or more separate circuit boards positioned or arranged such that the pressure sensors can measure or sense pressure characteristics related to the gas flow and / or ambient pressure.

[0185] The flow rate of the gas can be measured using at least two different types of sensors. The first type of sensor can be a thermistor, which can determine the flow rate by monitoring heat transfer between the gas flow and the thermistor. The thermistor flow sensor can operate the thermistor at a constant target temperature in the flow as the gas flows past around the thermistor. The sensor can measure the amount of power required to maintain the thermistor at the target temperature. The target temperature can be configured to be higher than the temperature of the gas flow such that at higher flow rates more power is required to maintain the thermistor at the target temperature.

[0186] The thermistor flow sensor can also maintain multiple (e.g., two, three, or more) constant temperatures at the thermistor so that the difference between the target temperature and the gas stream temperature is not too small or too large. Multiple different target temperatures allow the thermistor flow sensor to be accurate over a wide temperature range of the gas. For example, the thermistor circuit can be configured to be able to switch between two different target temperatures so that the temperature of the gas stream always falls within a certain range (e.g., not too close or too far) to one of the two target temperatures. The thermistor circuit can be configured to operate at a first target temperature of about 50°C to about 70°C, or about 66°C. The first target temperature can be associated with a desired flow temperature range of about 0°C to about 60°C, or about 0°C to about 40°C. The thermistor circuit can be configured to operate at a second target temperature of about 90°C to about 110°C, or about 100°C. The second target temperature may relate to a desired flow temperature range of about 20°C to about 100°C, or about 30°C to about 70°C.

[0187] The controller can be configured to adjust the thermistor circuit to change between at least a first target temperature mode and a second target temperature mode by connecting or bypassing a resistor in the thermistor circuit. The thermistor circuit can be arranged in a Wheatstone bridge configuration with a first voltage divider arm and a second voltage divider arm. The thermistor can be located in one of the voltage divider arms. More details of the thermistor flow sensor are described in International Publication No. WO 2018 / 052320, filed September 3, 2017, which is incorporated herein by reference in its entirety.

[0188] A second type of sensor may include an acoustic sensor assembly. An acoustic sensor including an acoustic transmitter and / or receiver may be used to measure the time of flight of an acoustic signal to determine the velocity and / or composition of the gas, which may be used in a flow therapy device. In one ultrasonic sensing topology (including an ultrasonic transmitter and / or receiver), a driver causes a first sensor, such as an ultrasonic transducer, to generate an ultrasonic pulse in a first direction. A second sensor, such as a second ultrasonic transducer, receives the pulse and provides a measurement of the time of flight of the pulse between the first and second ultrasonic transducers. This time of flight measurement may be used by a processor or controller of the respiratory device system to calculate the speed of sound of the gas flow between the ultrasonic transducers. In a second direction opposite to the first direction, the second sensor transmits a pulse, and the first sensor may receive the pulse and provide a second measurement of the time of flight, which may determine a characteristic of the gas flow, such as flow rate or velocity. In another acoustic sensing topology, an acoustic pulse transmitted by an acoustic transmitter, such as an ultrasonic transducer, may be received by an acoustic receiver, such as a microphone. More details of the acoustic flow sensor are described in WO 2017 / 095241, filed December 2, 2016, which is incorporated by reference in its entirety.

[0189] Readings from both the first and second type sensors can be combined to determine a more accurate flow measurement. For example, a predicted current flow rate can be determined using a previously determined flow rate and one or more outputs from one of the sensor types. The predicted current flow rate can then be updated using one or more outputs from the other of the first and second type sensors to calculate a final flow rate.

[0190] 3. Example embodiment of a two-stage leak detection process The methods and processes for determining leakage in a flow path are described with respect to the example respiratory device 10 described above, which is configured or operable as a flow therapy device to provide nasal high flow therapy via a non-sealing patient interface. As previously described, the methods and processes may also be applied to other respiratory devices and / or to other modes of operation and / or modes of therapy delivered by such devices.

[0191] 3.1 Overview of the leak detection process 22, a general flow diagram of one embodiment of a leak detection process or algorithm 700 is shown by way of example only. The leak detection process or method 700 in this example is implemented as an algorithm executed by a processor or controller of the device. In the following examples, this process or method will be referred to as the leak detection algorithm 700.

[0192] The algorithm 700 operates or executes during operation of the respiratory apparatus 10, i.e. when the respiratory apparatus 10 is generating a flow of gas. In some embodiments, the algorithm may operate when a patient is connected to the apparatus with their patient interface donned or partially donned to receive high-flow therapy, or when a patient has removed their patient interface and is disconnected from the apparatus.

[0193] In one configuration, the algorithm 700 operates or executes during the therapy and / or desiccation modes of the respiratory apparatus when the respiratory apparatus is generating a flow of gas. In one embodiment, in these modes of operation the leak detection algorithm is configured to detect leaks representative of a disconnection or removal of the humidification chamber from the flow path, although the algorithm may be configured to detect other types of leaks or breaks in the flow path.

[0194] In another configuration, the algorithm 700 operates or executes during a disinfection mode of the respiratory device. As described, during the disinfection mode, the respiratory device can be configured to generate a flow of gas through a disinfection kit or assembly connected in the flow path of the device. In one embodiment, in these disinfection modes of operation, the leak detection algorithm is configured to detect leaks that represent the disconnection or removal of one or more components of the disinfection kit or assembly, such as the disconnection, disconnection or dislodging of a disinfection tube or conduit or a filter component of the disinfection kit or assembly from the flow path.

[0195] As explained, the leak detection algorithm 700 is configured to detect leaks in the flow path of a respiratory apparatus. In this general example, the leak detection algorithm is described with respect to detecting leaks in the flow path caused by the humidification chamber of the humidifier being partially or completely removed or disconnected from the flow path during a treatment or drying mode of the apparatus (i.e., a "chamber off" or "chamber disconnected" condition). However, as noted above, it will be appreciated that the principles of operation of the leak detection algorithm can be applied to detect other types of leaks along the flow path, such as leaks caused by the patient conduit or tubing of the patient circuit being partially or completely disconnected from the gas outlet of the apparatus during a treatment or drying mode (i.e., a "tube off" or "tube disconnected" condition), or leaks at the flow path outlet of the apparatus. As noted above, the patient circuit typically comprises a conduit or tubing connected at one end to the gas outlet of the apparatus, which delivers a flow of gas to the patient's airway via a patient interface, such as a nasal cannula, connected at the other end of the conduit or tubing. Other leaks that can be detected may include partial or complete disconnection of connections or fittings or conduits that form or define a flow path in the device, or leaks due to holes or ruptures along the flow path of a conduit or tube of the device or patient circuit, including, for example, a hole or rupture in a humidification chamber. Typically, the leak detection algorithm is configured to detect substantial or large leaks in the flow path of the device or patient circuit, i.e., leaks that are significantly or much larger than leaks in a non-sealing patient interface of the patient circuit. Additionally or alternatively, as described above, the principles of operation of the leak detection algorithm can be applied to detect other leaks during the disinfection mode of the respiratory device, for example, the disconnection or dislodging of a disinfection tube or a filter component (e.g., a filter cap or a cap with filter) of a disinfection kit or assembly from the flow path of the device.

[0196] In one configuration, the leak detection algorithm 700 may detect leaks based on a known or measured relationship or model between the pressure of the gas flow and the flow rate of the gas flow. In particular, a pressure-flow characteristic curve or function or model for when the device is operating normally and when there is a leak (e.g., due to a humidification chamber being dislodged or some other type of leak) is used to generate one or more leak thresholds or limits used in the algorithm. In this configuration, the leak threshold is a leak pressure threshold or limit. As further described below, the threshold or limit may be a function of, or be based at least in part on, the flow rate and / or motor speed, and optionally one or more other operating characteristics or settings associated with the device or gas flow.

[0197] In another configuration, the leak detection algorithm 700 may detect leaks based on a known or measured relationship or model between the flow rate of the gas flow and the motor speed of the respiratory apparatus flow generator. In particular, a flow rate-motor speed characteristic curve or function or model for when the apparatus is operating normally and when there is a leak (e.g. due to a disconnected humidification chamber or other type of leak) is used to generate one or more leak thresholds or limits used in the algorithm. In this configuration, the leak threshold is a leak flow rate threshold or limit. As further described below, the threshold or limit may be a function of, or be based at least in part on, the motor speed and, optionally, one or more other operating characteristics or settings related to the apparatus or the gas flow.

[0198] In this general example, the leak detection algorithm is described with respect to detecting a leak in a flow path based on comparing a sensed pressure in the flow path to a leak pressure threshold. The same operating principles in this general example of the leak detection algorithm can also be applied to embodiments that detect leaks based on comparing a sensed flow rate in the flow path to a leak flow rate threshold.

[0199] In this general example, the leak detection algorithm is configured to compare pressure variables (e.g., pressure signals or data) from one or more pressure sensors configured to sense pressure characteristics of the gas flow in the flow path of the device. In this example, the algorithm then compares the pressure variables to two leak pressure thresholds. The first threshold is a "probable leak threshold" that indicates a possible or potential leak. The second threshold is a "certain leak threshold" that indicates a definitive leak. As will be explained in more detail below, the algorithm employs these two leak thresholds and a two-tiered approach to leak assessment (e.g., no leak = "chamber on" or leak = "chamber off") to minimize or reduce the likelihood of false positives (false leak alarms) occurring during operation. This is because at or in the low flow rates or ranges of the device's operating flow range, the pressure-flow characteristic curves or data between normal operation without leaks (e.g., chamber on) and leaky (e.g., chamber off) operation begin to at least partially overlap or converge, making it difficult to accurately distinguish between a leak condition (e.g., chamber off) and a no-leak condition (e.g., chamber on).

[0200] In one configuration, a definitive leak threshold has a low probability of false positive over at least a portion of its flow range, e.g., at least in the low flow region. A possible leak threshold is a more conservative threshold or limit that has a high probability of false positive over at least a portion of its flow range (e.g., at least in the low flow region), i.e., signifying a possible or potential leak condition or situation that requires further verification or determination.

[0201] In this example, if the first stage of the leak detection algorithm determines a potential or possible leak, the algorithm moves to a second stage of leak evaluation to either confirm or conclusively determine that there is a leak (e.g., the chamber is detached) or definitively determine that there is no leak (i.e., the chamber is attached).

[0202] First stage leak assessment Referring to the flow diagram of FIG. 22, the device may begin or be operating in normal operation delivering a flow of gas to a user or patient at a configurable user-set flow rate. The leak detection algorithm may begin operation 701 immediately when the normal operation of the device begins or after a preconfigured delay period during which the operating characteristic time is allowed to settle. After initiation, the leak detection algorithm operates continuously during normal operation of the device in a first stage of leak evaluation 702. In this first stage of leak evaluation 702, a pressure variable from a pressure sensor sensing the flow of gas in the flow path is compared to a critical leak threshold and a likelihood of leak threshold to determine whether one or more conditions are met. While operating in the first stage of leak evaluation 702, the device is considered to be operating normally with no leaks detected, i.e., a no leak condition or state is met.

[0203] If, in the first stage leak evaluation 702, the pressure variable is below a critical leak threshold, then a leak detection condition is met and a leak is deemed detected 703. In response to a leak being detected, the process moves from the first stage leak evaluation 702 to a leak detection situation or stage 704 where a leak alarm is generated.

[0204] In response to the generation of a leak alarm 704, one or more alarm actions may be performed. The alarm actions may include any one or more of the following: - Producing an audible, visual and / or tactile warning, alarm or notification that a leak has been detected. For example, a display screen on the device may display a visual notification (e.g., "loose chamber detected") indicating that a leak has been detected, as well as the nature of the leak and / or options for resolving the leak. - Freezing the flow generator motor speed at the current motor speed when the leak was detected, or at the original motor speed associated with the original user set flow rate. - Controlling the flow of gas through a flow generator to a predetermined flow rate or pressure. - To stop the operation of the device and / or the flow generator, i.e. to stop the gas flow completely. - Stop the humidifier from operating, i.e. turn off the humidifier heater. - Reducing the power applied to the humidifier heater. In one example, this can be accomplished by changing the current, voltage, pulse width modulation (PWM) frequency, or other control or power signal applied to the humidifier heater. - Reducing the power applied to the heater of the humidifier and the heater wires of the patient circuit tubing or conduits. In one example, this can be accomplished by lowering the patient dew point setting to a predefined lower setting, such as a dew point setting of 31 degrees Celsius or lower. - Deactivating the heater wires in the patient circuit tubes or conduits, i.e. turning the heater wires off. - Reducing the power applied to the heater wires of the tubes or conduits of the patient circuit. In one example, this can be accomplished by changing the current, voltage, pulse width modulation (PWM) frequency, or other control or power signal applied to the heater wires of the tubes or conduits. - sending or transmitting data indicative of the leak alarm or leak alarm information to an external system or server or device via a data communication link or multiple data communication links via a communication module or network interface (e.g., modem) of the device. In one example, the leak alarm information can be transmitted as part of treatment data, treatment reports, diagnostic reports, or other data sets or reports transmitted or transmitted from the device. Additionally or alternatively, a message or alarm may be sent to a local device, such as a smartphone or tablet. For example, the local device can be associated with a clinician or caregiver. - Any combination of the above alarm actions.

[0205] In one configuration, if the pressure variable falls below the possible leak threshold in the first stage leak evaluation 702, a possible leak condition or situation is met and the process moves to the second stage leak evaluation 707 as shown at 706. In another configuration, if the pressure variable falls below the possible leak threshold and exceeds the certain leak threshold, a possible leak condition or situation is met and the process moves to the second stage leak evaluation 707.

[0206] The purpose of the second stage leak evaluation 707 is to confirm a possible leak condition as a definite leak or discard a possible leak condition as no leak. In one configuration, the second stage leak evaluation 707 may repeat or loop until it determines that a leak has been detected or that no leak has been detected, or until one or more other optional termination conditions are met. The second situation leak evaluation 707 is discussed further below.

[0207] If none of the above leak or possible leak conditions are met based on the evaluation comparing the pressure variable to the definite leak threshold and the possible leak threshold, the first stage leak evaluation 702 assumes that no leak is detected, i.e., the no leak condition or situation remains met. As shown at 705, the algorithm remains in the first stage leak evaluation and continually evaluates the pressure variable against the leak threshold as described above for definite leak or possible leak conditions.

[0208] Second stage leak assessment In this configuration, the second stage leak assessment 707 involves increasing the current operating motor speed in dynamic or predetermined increments to a higher motor speed and then re-evaluating the updated pressure variables at the higher motor speed against the sure leak threshold and the possible leak threshold to determine the possible leak condition as either sure leak or no leak.

[0209] If the reassessment or evaluation at the higher motor speed does not determine a possible leak condition in the second stage leak evaluation 707, the motor speed is again incrementally increased to yet another higher motor speed and the updated pressure variable is again compared to the threshold value to determine a leak or no leak condition. This process of incrementally increasing the motor speed and reassessing the pressure variable against the threshold value repeats until a leak or no leak condition is met or another optional termination condition is met.

[0210] For example, in one configuration, the algorithm may exit second stage leak evaluation 707 when the motor speed rises to a configurable or preset maximum motor speed, or the algorithm loops at second stage leak evaluation 707 only while the motor speed is below a maximum motor speed threshold. Once the motor speed threshold is exceeded or the motor speed condition is no longer met, the algorithm may exit second stage leak evaluation 707 and return to first stage leak evaluation 702 and normal operation with an indication that no leak was detected.

[0211] In second stage leak evaluation 707, if the updated pressure variable at the higher motor speed falls below the sure leak threshold, the possible leak condition is determined to be a sure leak. If a sure leak is detected, the algorithm exits second stage leak evaluation 707 and proceeds to leak detected state 704, as shown at 708, and initiates one or more alarm actions as described above.

[0212] In second stage leak evaluation 709, if the updated pressure variable at the higher motor speed is above the sure leak threshold and above the possible leak threshold, the possible leak condition is determined to be no leak. If the no leak condition is met, the algorithm ends second stage leak evaluation 707 and proceeds to first stage leak evaluation 702 and normal operation as shown at 709.

[0213] Optionally, upon exiting the second stage leak evaluation 707 without a detected leak (709), the algorithm may be configured to update or adjust one or more of the threshold limits, as shown at 712. For example, in one configuration, the threshold adjustment 712 may include lowering or tapering the possible leak detection threshold by a dynamic or predetermined amount to reduce or minimize the algorithm 700 repeating in an infinite loop. In one configuration, the threshold adjustment 712 step may include lowering the possible leak threshold at or in an original motor speed and / or measured flow rate associated with normal operation prior to entering the second stage leak evaluation 7097. In other configurations, the threshold adjustment 712 step may include lowering the possible leak threshold over the entire range of operating motor speeds and / or flow rates of the device, or over a predetermined region of the range of operating motor speeds and / or flow rates of the device, or at the current or latest set or target motor speed and / or flow rate operating upon exiting the second stage leak evaluation 707.

[0214] In the second stage leak evaluation 707, if neither leak detected condition 708 nor leak not detected condition 709 is met based on the above evaluation, then a possible leak condition is deemed not to have been determined. In one configuration, if neither leak condition 708 nor no leak condition 709 is met within a predetermined period of time, the second stage leak evaluation 707 remains in the possible leak condition situation, as shown at 710, again incrementally increases the motor speed to yet another higher motor speed, and then repeats by again re-evaluating the new pressure variable against the threshold value in an attempt to determine the possible leak condition as either leak condition 708 or no leak condition 709, as described above. This process repeats until the second stage leak evaluation determines the possible leak condition as either a leak condition or a no leak condition, or until another optional termination condition is met (such as, by way of example only, reaching a maximum motor speed condition).

[0215] Leak detection status - Alarm resolution Once the algorithm 700 enters a leak detection state 704, a leak alarm and / or alarm action may be implemented as described above. During this alarm state 704, the algorithm may be configured to continuously or periodically monitor a pressure variable of the gas flow to check if the leak (e.g., a disconnected chamber) has been eliminated. For example, the algorithm may be configured to continuously or periodically compare the pressure variable to a positive leak threshold or another threshold indicative of a leak elimination condition. If the pressure variable exceeds the threshold, the leak elimination condition is met and the algorithm exits the leak detection state 704 and returns to first stage leak evaluation 702 and normal operation, as shown at 711.

[0216] When the leak alarm is resolved (e.g., when the chamber is reinstalled or reconnected in the device flow path), any alarm action may be stopped and the device may return to normal operation at the previous user-set flow rate settings. For example, if the motor speed was frozen as an alarm action, the motor speed is unfrozen and normal flow control resumes via the flow generator motor speed control. If any alarm notifications, whether audible and / or visual, were initiated, such alarms are cleared or stopped.

[0217] General characteristics of the leak detection algorithm One or more of the following features or aspects of the leak detection algorithm 700 may optionally be applied during operation of the algorithm.

[0218] The leak detection algorithm 700 may operate continuously during operation of the device, including when operating to provide flow therapy to a patient or user, for example in a treatment mode, to check for leaks based on real-time pressure variable data or signals received from a pressure sensor that senses the pressure characteristics of the gas flow in the flow path. It will be appreciated that the leak detection algorithm may alternatively be configured to operate periodically, or on an ad-hoc basis, or at predetermined time periods based on the mode of operation, or during specific periods of a flow therapy session, such as during initiation or start-up, or at other time periods.

[0219] In some configurations, the leak detection algorithm 700 may also be implemented or executed during non-therapeutic modes of the device. By way of example, the leak detection algorithm may operate while the device is operating in a non-therapeutic mode, such as during a drying mode and / or a disinfection mode. In such modes, the device is configured to generate a flow of gas through the device and / or a connected patient circuit and / or a disinfection kit assembly, for example, to dry and / or disinfect one or more components in the flow path of the device and / or the connected patient circuit. In such non-therapeutic modes, depending on the type of mode, the leak detection algorithm may function to generate an alarm or warning when a leak is detected, such as a chamber or tube disconnection, or a component of the disinfection kit assembly, because if these components are removed or disconnected from the flow path, they may not be dried and / or disinfected, and / or the drying mode and / or disinfection mode may not operate properly.

[0220] The leak threshold used in the leak detection algorithm in the non-therapeutic mode may be the same or different than that used in the therapeutic mode. In some non-therapeutic modes, such as the drying mode and / or the disinfection mode, the leak threshold and / or function may be calibrated and / or adjusted to account for changes or differences in the flow path of the device compared to when operating in the therapeutic mode. In one example, in some such non-therapeutic modes, the entire patient circuit (e.g., conduits and patient interface) or components of the patient circuit (e.g., conduits and interface, or only the interface) may not be connected to the device or otherwise present in the flow path. In another example, in some such non-therapeutic modes, the humidification chamber may be removed and the disinfection kit assembly may be installed in the flow path. In such a situation, the absence of one or more such components or the addition of new components may change the flow path characteristics, and the leak threshold and / or function may be adjusted accordingly.

[0221] In some configurations, the leak detection algorithm may be limited to operate only during a particular user-set flow rate range and / or target motor speed range. For example, in one configuration, the algorithm may automatically operate for a relatively low or low flow rate range and / or a relatively low or low target motor speed range where it is more difficult to distinguish between a leak and no leak for reasons previously explained in a non-sealed system. Such relatively low flow rate ranges may include, by way of example only, less than 30 L / min, or less than 15 L / min, or less than 10 L / min. A two-stage leak detection algorithm configuration may enable the algorithm to detect a possible leak when the device is operating in a relatively low flow rate range and / or a relatively low target motor speed range, and then incrementally increase the flow rate and / or motor speed until a leak is identified that becomes easier to identify as the flow rate and / or motor speed increase. By way of example only, the relatively low flow rate range may correspond to one used with neonatal patients or when the patient is using a neonatal interface, e.g., a cannula smaller than an adult cannula. Typically, the relatively low flow rates or flow rate ranges are used for neonatal patients, children, or other patients who require lower flow rates for treatment compared to the higher flow rates typically used for adults.

[0222] In some configurations, the two-stage leak detection algorithm including stages 702 and 707 can operate during the relatively low flow rate range and / or motor speed, and an alternative single-stage leak assessment using a single leak threshold can operate in the remaining higher flow rate range and / or motor speed range of the operating flow rate range. For example, during the relatively low flow rate settings and / or relatively low target motor speeds, where the determination of the actual leak condition is more difficult, the two-stage leak detection technique 700 can be implemented including checking the pressure variable of the gas flow against a certain leak threshold and a possible leak threshold to reduce or minimize false positives. At the remaining higher flow rate settings, where the possibility of false positives in leak detection is lower, a single-stage leak assessment based on comparing the pressure variable to a single leak threshold can be employed to determine a leak or no leak condition during operation without using a second stage assessment with increasing flow rate and / or motor speed. If the pressure variable is above the single leak threshold, normal operation continues, and if the pressure variable is below the single leak threshold, a leak detection condition is met and a leak alarm is generated.

[0223] In one configuration, the leak threshold utilized in the leak detection algorithm 700 can be derived based on a measured, known, or modeled relationship between pressure and flow rate for normal operation of the device and operation with a leak (e.g., with a loose chamber or a loose tube, depending on which type of leak the algorithm is configured to detect).

[0224] In one configuration, the threshold relationship may be expressed as a function, equation, threshold curve, or look-up table in which the pressure leak thresholds used in the leak assessment depend at least on the flow rate of the flow generator at the time of the assessment. For example, the specific possible leak and certain leak thresholds used in the various leak determination assessments at different stages of the algorithm depend on or are a function of the particular flow rate operating at the time of the assessment.

[0225] In another configuration, the leak threshold may depend on and / or be a function of the particular flow rate and / or motor speed operating at the time of the threshold evaluation, as well as one or more other inputs or sensed variables or characteristics associated with the device or gas flow at the time of the evaluation. By way of example, the one or more other inputs or sensed variables or characteristics may include, but are not limited to, absolute pressure of the gas flow, temperature of the gas flow, oxygen concentration of the gas flow, ambient pressure of the environment.

[0226] In some configurations, the leak detection algorithm 700 may be operable throughout the entire operating flow rate range of the device and / or across any operating mode, without modification. For example, the leak detection algorithm may operate continuously without modification of the threshold functions and / or processes, regardless of the flow rate settings of the device or changes in flow rate settings during or between flow therapy sessions.

[0227] In some configurations, the leak detection algorithm 700 may be configured to be independent of the operating mode of the device.

[0228] In some configurations, the leak detection algorithm 700 may be operable with multiple different types and / or sizes of patient interfaces without modification. For example, the leak detection algorithm may be configured to operate continuously without modification of the threshold functions and / or processes regardless of changes in the type or size of the patient interface used in the patient circuit connected to the gas outlet of the device. For example, the leak detection algorithm may be configured to be independent of the type or size of the patient interface (e.g., adult, child, or pediatric cannula, etc.) used with the flow therapy delivered by the device.

[0229] In one use case, the leak detection algorithm may be beneficial in operating situations where the device is operating with a child or pediatric cannula at low flow rates for a child or neonatal patient. In such operating situations, the flow rates are at the low end of the operating range, and the ability to distinguish or identify leaks is difficult, as explained above. The leak detection algorithm provides a means to reliably and robustly determine leaks (e.g., a disconnected chamber or disconnected tube condition) in such operating conditions or settings.

[0230] In some configurations, the leak detection algorithm 700 can be configured to generate a preliminary notification or warning upon detecting a possible leak condition at 706 as it moves to a second stage leak evaluation 707. For example, the possible leak warning may be visual, audible and / or tactile and may include generating or presenting a notification or indication on a display screen of the device. By way of example, such a preliminary notification may provide information to the user regarding the operation of the device, as the algorithm may noticeably loop incrementally increasing the motor speed and / or flow rate at discrete intervals as it attempts to determine a possible leak as a definite leak condition 708 or no leak condition 709 in the second stage evaluation.

[0231] In some configurations, the leak detection algorithm 700 is configured to make a comparison or evaluation decision based on whether the pressure variable is above or below an associated threshold value for a given or predetermined minimum evaluation period. For example, an evaluation decision is made based on whether the pressure variable is consistently above or below a threshold value for a minimum evaluation period to determine whether a particular condition is met and to determine which state or stage of the leak detection algorithm to proceed to. This configuration can help to avoid noise or spikes in the pressure variable data or signal from unduly affecting the reliability of the decisions made by the algorithm.

[0232] In some configurations, the leak detection algorithm includes a predetermined or unique minimum evaluation period for each particular threshold comparison in the process flow. For example, each minimum evaluation time may depend on a predetermined threshold comparison or stage or state of the algorithm when the comparison is being made. In one configuration, the minimum evaluation time for the threshold comparison in the first stage leak evaluation 702 is longer than the minimum evaluation time for the threshold comparison in the later second stage leak evaluation 707. In such a configuration, a shorter minimum evaluation time for the second stage leak evaluation 707 may be beneficial because the second stage leak evaluation 707 includes interrupting normal operation of the device and increasing the motor speed for discrete intervals to determine a possible leak condition as either a confirmed leak condition or a no leak condition, so that the shorter comparison evaluation time may reduce any long interruptions to normal operation of the device.

[0233] In some configurations, the minimum evaluation period utilized in the leak detection algorithm may be uniform or the same for all or at least some threshold comparisons. In one example, the minimum evaluation time may depend on a particular stage or situation of the algorithm. For example, the minimum evaluation time associated with a first stage of leak assessment may be substantially the same, and the minimum evaluation time associated with a second stage of leak assessment may be substantially the same.

[0234] The leak detection algorithm can be configured to detect one or more different types of leaks in or associated with the flow path of the device or peripheral components connected to the flow path, such as, but not limited to, the patient circuit (e.g., conduits and patient interfaces) connected to the gas outlet of the device. In one configuration, the leak threshold or leak threshold characteristic is tailored to the particular leak to be detected. In other configurations, a generic leak threshold or leak threshold characteristic may be utilized to detect one or more different types of leaks in the flow path.

[0235] In one configuration, the leak detection algorithm is configured to detect a leak in the form of or indicative of the humidification chamber being removed or disconnected, whether partially or completely, from the flow path (e.g., "chamber off"). For example, in this configuration, the leak detection algorithm functions or operates as a humidification chamber connection status detector (i.e., whether the chamber is connected in the flow path of the device (i.e., "chamber on") or whether the chamber is removed or disconnected from the device (i.e., "chamber off").

[0236] In another configuration, the leak detection algorithm is configured to detect a leak in the form of, or indicative of, a disconnection of the patient circuit from the gas outlet of the device (e.g., "tube off"). In this configuration, the leak detection algorithm functions or operates as a patient circuit or conduit connection status detector (i.e., whether the patient circuit or conduit is connected to the gas outlet of the device (i.e., "tube on") or disconnected from the gas outlet (i.e., "tube off").

[0237] In another configuration, the leak detection algorithm is configured to detect a leak in the form of, or indicative of, a detachment or dislodgment of one or more components of a disinfection kit assembly installed in the flow path of the respiratory apparatus during the disinfection mode of operation.

[0238] In one configuration, the device may be configured to operate multiple versions of the leak detection algorithm in parallel, alternating, selectively, or sequentially, with each version of the leak detection algorithm configured to detect leaks of a different type or nature.

[0239] Sections 3.2-3.4 below provide further implementations and configuration examples of the two-stage leak detection algorithm described in the general example above. Any one or more of the general features above may be applied to any one or more of the following examples.

[0240] 3.2 Detailed Example of Leak Detection Process - Leak Pressure Threshold 23, there is shown, by way of example only, a detailed flow diagram of one embodiment of a leak detection process or algorithm 800. This exemplary algorithm 800 utilizes similar operating principles of the general algorithm 700 described above, and it will be understood that features described with respect to either algorithm may also be applied to the other algorithm.

[0241] This embodiment of the leak detection algorithm 800 is configured to detect leaks representing or caused by the humidification chamber being removed or disconnected from the flow path of the device (i.e., "chamber off"), such as when the chamber is removed from the humidifier chamber bay or compartment of the housing of the device for cleaning, refilling, repair or replacement, or if the chamber is accidentally dropped or disconnected from the flow path.

[0242] In this embodiment, the leak detection algorithm 800 begins (801) during normal operation of the device, e.g., when the device is delivering a flow of gas at a configurable user-set flow rate during a flow therapy session, e.g., while operating in a therapy mode. The configurable user-set flow rate for a flow therapy session may depend on the patient and / or the patient's prescribed therapy parameters or settings. As will be appreciated, different flow rate settings can be used for flow therapy for adult and pediatric or neonatal patients. In some embodiments, the leak detection algorithm that determines the chamber connection status (e.g., chamber disconnection) is operable over the entire range of operable flow rates, or in other embodiments, over a predetermined subset or subsets of the entire flow rate range.

[0243] In this embodiment, the algorithm 800 receives a pressure variable representing a pressure signal or data sensed by a gauge pressure sensor configured to sense a gauge pressure of the flow of gas in the flow path, however, it will be appreciated that the pressure variable used by the algorithm may be from one or more other types of pressure sensors associated with the flow of gas in the flow path.

[0244] In this embodiment, the algorithm mainly comprises a first stage leak assessment 802 and a second stage leak assessment including steps and assessments or decisions at 803, 804 and 805. The first stage leak assessment 802 may determine whether there is a definite leak, a possible leak, or no leak. The second stage leak assessment is configured to determine the possible leak decision from the first stage assessment as either a definite leak or no leak.

[0245] In one embodiment, the algorithm 800 is suspended or delayed from operation until a predetermined delay period has expired from one or more particular events. These events may include any one or more of the following: the start of a therapy session, the start of normal operation or flow therapy control, and the resolution of a leak alarm or other alarm. For example, the algorithm 800 is not operational and cannot generate or trigger a leak alarm during the delay period following one or more selected or configured such events. In other embodiments, the algorithm 800 may be continuously and immediately operational at the start of a therapy session or when normal flow control resumes after a leak alarm has been resolved.

[0246] First stage leak assessment In this embodiment, after any required delay period has expired, the algorithm 800 begins (801) by proceeding to a first stage leak evaluation in step 802. In this first stage leak evaluation 802, the gauge pressure variable is compared to a certain leak threshold and a possible leak threshold to determine the leak status of the device, e.g., leak detected, possible leak, or no leak. In this embodiment, one or each condition may be considered to be met or detected based on the respective evaluation criteria being met, as described below. In this embodiment, the various evaluations based on comparing the gauge pressure to one or more thresholds may be performed simultaneously or in parallel. In other configurations, the evaluation of which leak conditions are met may be configured to be performed sequentially or in a particular conditional order.

[0247] While operating in the first stage of leak assessment 802, the device can be considered to be in normal operation with no leaks detected, i.e. in a no leak situation. In this situation or stage, the breathing apparatus continues normal operation and normal flow control with the set flow rate.

[0248] In this embodiment, the algorithm obtains and / or receives input data representing the measured or sensed flow rate of the gas flow, the measured or sensed gauge pressure variables, and the leak threshold value for evaluation. The input data may be obtained according to a particular sampling frequency or continuously as data becomes available from the sensor and / or the main controller and / or the memory of the device. In one configuration, the input data may be a moving average based on a moving window of data. The window of data may be determined based on, for example, a configured period or number of data samples. In one example, the input data may be a 10 second moving average of the sensed flow rate, sensed gauge pressure, and leak threshold value. In another configuration, the input data used by the leak detection algorithm may be the most recent instantaneous data of the sensed flow rate, sensed gauge pressure, and leak threshold value.

[0249] In this embodiment, one of the evaluations performed by the algorithm in step 802 is to determine a certain leak condition. In this embodiment, to determine a certain leak condition, the algorithm compares the gauge pressure variable to a certain leak threshold P (which in this embodiment is a pressure threshold) that represents a certain leak condition. leak Compare with the gauge pressure variable P gauge is the leak threshold P leak If the gauge pressure variable P is less than 806, then a leak condition is met and the algorithm triggers or generates a leak alarm at 806. gauge is the threshold for a reliable leak P over a minimum evaluation period of 15 seconds. leak , although it will be appreciated that in other embodiments this period may be adjusted or varied.

[0250] If a leak detection condition is met based on the evaluation in step 802, the algorithm moves to a leak alarm or leak detection situation or phase in 806. In the leak detection situation 806, the algorithm may trigger one or more alarm actions, such as generating an audible, visual or tactile leak detection alarm indicating that the chamber is disconnected or isolated, and / or controlling or stopping the flow rate or motor speed, or other control actions, as described above with respect to the algorithm 700. In this embodiment, the algorithm 800 in the leak detection situation 806 may be configured to perform one or more alarm actions. In this example embodiment, the algorithm 800 may perform any one or more of the following example alarm actions: While in the leak alarm condition 806, the target motor speed at the current time the leak is detected is frozen so that the motor speed does not change from its current value until the leak is cleared. Generating or triggering audible, visual and / or tactile alarms or notifications to the user (e.g. a message or notification on the display of the breathing apparatus and / or an audible alarm via a speaker or audio device of the breathing apparatus). Disconnecting or reducing the power applied to the humidifier, such as by disconnecting or reducing the power applied to the heater plate of the humidifier. Depending on the configuration of the humidifier in the device, this may be advantageous in a leak condition as the heater plate of the humidifier may be exposed and therefore pose an increased safety risk to the user when the chamber is disconnected. Turning off or reducing the power applied to the heater wires of the patient circuit conduits connected to the device.

[0251] Upon reaching a leak detection condition 806, the algorithm 800 may also be configured to determine or evaluate whether the leak alarm has been resolved, e.g., whether the chamber has been reconnected or reinstalled to the device and / or flow path. In this embodiment, the algorithm at 806 determines whether the pressure variable P gauge The leak threshold P leak、 Alternatively, the gauge pressure variable P may be continuously evaluated or determined to have eliminated the leak by comparing it to another specific alternate threshold value to confirm elimination of the leak. gauge over a minimum evaluation period, which in this embodiment is 3 seconds but can be adjusted in other embodiments. leak If the threshold is exceeded, the leak alarm is considered cleared. If the leak alarm is cleared, the algorithm returns to normal operation or normal flow control with the first stage leak evaluation 802 and set flow rate. leak If the threshold is not exceeded, the algorithm remains in the leak detected state 806 and continues to check for clearance of the leak alarm.

[0252] In this embodiment, one of the other evaluations made by the algorithm in step 802 is to determine a possible leak condition. In this embodiment, to determine a possible leak condition, the algorithm evaluates the gauge pressure variable P gauge is a possible leak threshold P (which in this embodiment is a pressure threshold) that represents a possible or potential leak condition. maybeIn this embodiment, the gauge pressure variable P gauge is the leakage probability threshold P maybe If so, then a possible leak condition is met and the algorithm moves to a second stage leak evaluation (starting at 803) to determine the identified possible leak as a definite leak or no leak. In this embodiment, the minimum evaluation period is 10 seconds, although this may vary in different embodiments.

[0253] If, based on the above evaluation, neither the definite leak condition nor the possible leak condition is met, the algorithm assumes that no leak is detected and remains in the first stage of normal operation leak evaluation 802, i.e., the no leak condition remains met and the device continues with normal flow control.

[0254] Second stage leak assessment If the algorithm detects a possible leak condition at 802, it moves to a second stage of leak assessment beginning at step 803. In this embodiment, prior to entering the second stage of leak assessment to determine the possible leak as a definite leak or no leak, the algorithm 800 is configured to store the measured flow rate and sensed pressure variables (e.g., sensed by a flow sensor or other sensing arrangement in the flow path) that occurred prior to entering the second stage of leak assessment at step 803. In one configuration, the stored values ​​of the measured flow rate and stored sensed pressure variables may represent or be derived from moving averages of these measured or sensed variables, as described above. For example, in one configuration, the algorithm may receive or calculate during operation moving averages of the measured flow rate and sensed pressure variables from which values ​​may be extracted and stored prior to entering the second stage of leak assessment. By way of example, the stored values ​​of the measured flow rate and sensed pressure variables may be used in later algorithm steps including updating and / or adjusting one or more of the leak threshold limits.

[0255] In this embodiment, the second stage leak assessment involves increasing the current target motor speed in a predetermined increment or to a first or next preset higher motor speed at 803. In this embodiment, the algorithm is configured to increase the motor speed and hold it at the first higher motor speed for a predetermined or maximum period of time. In one configuration, the period may be 4 seconds, although this may vary in alternative embodiments. As will be explained later, during the or each iteration to the next higher motor speed, the higher motor speed is maintained for a configured period of time (e.g., 4 seconds in this example) during which a second stage leak assessment 804 is performed to attempt to determine the likelihood of a leak as a confirmed leak condition or a no leak condition.

[0256] Upon reaching the higher motor speed after ramping up at 803, the algorithm 800 initiates one or more second stage leak assessments at 804. For example, the updated or new sensed pressure variable P gauge However, new or updated certain P leak and possible P maybe The possible leak condition is compared to thresholds to determine whether the possible leak condition can be determined as a definite leak condition or a no leak condition. Each condition is again determined by the sensed gauge pressure variable P, as described below. gauge The leak thresholds may have their own evaluation criteria to be met based on comparing the leak thresholds to one or more of the leak thresholds.

[0257] In this embodiment, one of the evaluations made by the algorithm in step 804 is to determine the possible leak condition as a confirmed leak condition. In this embodiment, to determine the possible leak condition, the algorithm uses the updated sensed pressure variable P gauge Updated reliable leak threshold P leak In this embodiment, the new P leakThe threshold value of the gauge pressure variable P is updated or determined based at least in part on the flow rate of the gas flow generated at the new higher motor speed and / or the first higher motor speed. gauge is greater than P for the shortest evaluation period (e.g., 3 seconds or another configurable period). leak If it does fall below the threshold, the possible leak condition is confirmed or determined to be a confirmed leak condition and the algorithm proceeds to leak detection state 806 and generates a leak alarm or initiates one or more alarm actions as previously described.

[0258] In this embodiment, one of the other evaluations made by the algorithm is to determine the possible leak condition as a no-leak condition. In this embodiment, to determine the no-leak condition, the algorithm uses the updated sensed pressure variable P gauge , the updated leak probability threshold P maybe and the updated reliable leakage threshold P leak As explained above, the updated threshold value may be derived or determined based at least in part on the flow rate of the gas flow generated at the new higher motor speed and / or the first higher motor speed. gauge for a minimum evaluation time (e.g., 3 seconds or another configurable time). maybe Above the threshold, P leak If the threshold is exceeded, the likelihood of a leak is determined as no leak was detected and the algorithm returns to the first stage evaluation 802 and normal operation and / or flow control.

[0259] In this embodiment, upon finishing the second stage leak assessment at 804 (after determining that the potential leak is no leak), the algorithm may optionally perform a threshold adjustment process at 807 before returning to step 802 and normal operation 801. In this embodiment, the threshold adjustment process 807 adjusts the P maybeThe threshold can be adjusted or lowered. In one configuration, P maybe The threshold value may be adjusted based on an adjustment or correction function 807 having one or more variables. By way of example, the variables of the adjustment or correction function may include the measured flow rate and sensed pressure variable values ​​stored prior to entering the second stage leak assessment in step 803, as described above. Additionally, the adjustment or correction function may include one or more additional variables or constants. In one configuration, the adjustment or correction function may have a constant variable that depends on the stored measured flow rate, such that the magnitude of the adjustment may vary depending on the stored measured flow rate. In one configuration, the adjustment or correction function may have a constant variable that depends on the stored measured flow rate, such that the magnitude of the adjustment may vary depending on the stored measured flow rate. In one configuration, the adjustment or correction function may have a constant variable that depends on the stored measured flow rate, such that the magnitude of the adjustment may vary depending on the stored measured flow rate. maybe A constant variable may be configured to make smaller adjustments to the threshold.

[0260] In one embodiment, the threshold adjustment function 807 is a function of the buffer value P buffer Based at least in part on P maybe In one configuration, P buffer The value may be determined at least in part by the measured flow rate stored after completing the first stage 802. In another configuration, P buffer The value may be a constant. In one configuration, P maybe The threshold value is derived from a threshold function that depends on the measured flow rate and one or more constants. In this example configuration, the threshold adjustment function is P buffer In another example, the threshold adjustment function is configured to adjust one or more constants of a threshold function based at least in part on the value of P buffer value and P maybe One or more constants of the threshold function are configured to be adjusted based at least in part on the threshold and the measured pressure values ​​stored after completing the first stage 802 .

[0261] In one embodiment, the threshold adjustment function 807 is a function of the buffer value P buffer Based at least in part on P maybeThe threshold may be adjusted. buffer has been modified to prevent infinite loops in the leak detection algorithm. maybe It may be a variable configured to adjust the threshold. For example, P buffer P is set to prevent the leak detection algorithm from looping through the following process: maybe The threshold is a function derived or pre-configured value that adjusts the threshold value, i.e., (1) detecting a possible leak in a first stage evaluation 802, (2) gradually increasing the motor speed (one or more times) in a second stage evaluation 803-805 to determine that the possible leak is not a leak, and (3) ending the second stage evaluation to again detect a possible leak and return to the same P. maybe The first stage of evaluation is performed based on the threshold value, and steps (1) to (3) are repeated in an infinite loop without any change in the flow path characteristics. maybe The threshold value is adjusted or adapted over time as the leak detection algorithm operates.

[0262] In some configurations of the adjustment or correction function 807, the P at discrete measured flow rates detected before entering the second stage leak evaluation at 803 is maybe The threshold may be decreased or tapered by a calculated or predetermined amount. maybe The entire threshold function or curve may be decreased or tapered by a calculated or predetermined amount throughout the operating flow range.

[0263] Returning to the second stage leak assessment at 804, if neither a sure leak condition nor a no leak condition is met based on the assessments described above, then the possible leak condition is considered pending. In this embodiment, if the possible leak condition is pending for a timer-based predetermined period (e.g., 4 seconds in this example, but could be another configurable period), then the second stage leak assessment process repeats, but at a higher motor speed.

[0264] In this embodiment, if the timer expires and a possible leak condition is pending, the algorithm exits 804 and begins a motor speed check 805. In this embodiment, the motor speed check 805 checks the current target motor speed against a preset or configurable motor speed threshold (MAX RPM )

[0265] In this embodiment, a motor speed check 805 checks whether the current target motor speed is greater than the motor speed threshold MAX RPM If so, the algorithm terminates the second stage leak evaluation, determines the potential leak as a no leak condition, and returns to first stage 802 and normal operation via the threshold adjustment process 807 described above. The motor speed check 805 provides an additional exit condition for the algorithm, preventing it from looping indefinitely in the second stage evaluation and / or increasing the motor speed beyond safety or component thresholds.

[0266] In the motor speed check 805, it is determined whether the current target motor speed is equal to or lower than the motor speed threshold MAX. RPM If so, the algorithm loops back to step 803 and again increases the first higher motor speed to the second or next higher motor speed and repeats the evaluation at 804 in an attempt to determine the leak probability as a definite leak condition or a no leak condition.

[0267] As shown, the second stage involves continuously or repeatedly incrementally increasing the motor speed by a predetermined amount or to the next predetermined higher motor speed and then evaluating at 804 until a leak condition is met, a no leak condition is met, or a motor speed check fails at 805. As will be appreciated, depending on the evaluation, the second stage of the algorithm may be completed once, twice, or multiple times before terminating back to 802 (no leak) or 806 (leak detected).

[0268] It will be appreciated that the motor speed increment in step 803 may be a preset or configurable increment, or may be incremental to the next highest motor speed in a preset or configurable series or array of preselected discrete higher motor speeds. By way of example only, in one configuration, the motor speed increase in step 806 is based on incrementally increasing the current motor speed to the next highest motor speed in a series or array that includes motor speeds of 5000 rpm, 6750 rpm, 8500 rpm, 10250 rpm, and 12000 rpm, such that the motor speed increases by 1750 rpm for each cycle or loop of the second stage leak assessment. In this example, the pressure variable is P maybe and P leak There are five possible discrete motor speed steps that are compared to the threshold, although this may be changed to more or fewer steps as required.

[0269] In this embodiment, the leak detection algorithm 800 repeats upon returning to the first stage of leak assessment and normal operation at 802. In one configuration, the leak detection algorithm operates continuously as it receives updated real-time sensed pressure variable data from the pressure sensor. In other configurations, the leak detection algorithm may be configured to operate periodically. As previously mentioned, in some configurations, when the device begins or resumes normal operation, the leak assessment comparison against the leak threshold may be suspended or delayed for a predefined delay period after a predefined event. Such events may include, but are not limited to, the start of a new therapy session or a new user-set flow rate, the clearance of a previous leak alarm at 806, or when normal operation or flow control is resumed at 802, for example, after the leak alarm has been cleared or after the second stage of leak assessment has been terminated with no leak detected.

[0270] Leak Threshold An example of a leak threshold associated with the leak detection algorithm 800 will now be further described. As discussed, a reliable leak threshold Pleak and the leakage probability threshold P maybe can be based on the measured flow rate and / or motor speed operating at the time of the evaluation comparison. leak and P maybe The threshold value may depend on or be a function of at least the sensed flow rate of the gas flow and / or the motor speed of the flow generator, and optionally one or more other variables or operating characteristics of the device and / or the gas flow. leak and P maybe The thresholds may be functions, threshold curves or lines, or may be provided in the form of look-up tables. At each stage of the leak detection algorithm, thresholds may be extracted from the functions, threshold curves or lines, or look-up tables based on at least the current sensed flow rate and / or flow generator motor speed, as well as any other variables.

[0271] 24A, a pressure versus flow plot 1900 is shown to demonstrate the nature of the leak threshold used in the leak detection algorithm. As previously explained, a leak is detected in this embodiment when the humidification chamber is partially or completely removed or disconnected from the device's flow path, and the leak threshold is derived based on the pressure versus flow characteristics associated with gas flow in a device operating normally with the chamber attached and in a device operating with a leak with the chamber removed.

[0272] P leak An example threshold function is depicted as a threshold curve or line 1901 on the pressure versus flow graph at 1900. maybe An example threshold function is depicted as a threshold curve or line 1902 on the pressure versus flow graph at 1900 .

[0273] The function or curve or data represented at 1903 is the sensed pressure characteristic of the gas flow versus the operating flow range for a device operating normally with the chamber attached. The function or curve or data represented at 1904 is the sensed pressure characteristic of the gas flow versus the operating flow range for a device operating with a leak due to the chamber being removed. As shown in the low flow region highlighted at 1905, the pressure vs. flow curves 1903 and 1904 for normal and leaky operation converge in this region, making it difficult to identify a true or definite off-chamber leak at low flow rates. The leak detection algorithm of the present disclosure provides a means to address this issue by incrementally increasing the motor speed to provide a clearer distinction between the curves to conclusively determine a leak (e.g., off-chamber) or no leak (e.g., on-chamber) condition.

[0274] For further explanation, referring to FIG. 24B, a positive leak P leak A threshold function, curve or line 1901 and a possible leak P maybe A threshold function, curve or line 1902 is shown isolated on the pressure versus flow graph. The area generally indicated at 1906 is the "maybe area" or "potential leak area." As shown, the potential leak area 1906 is a region of uncertainty, i.e., a region of potential leak ... leak Above the threshold of 1901, P maybe This is the region at the lower end of the flow range below a threshold 1902. By way of further explanation, measured or sensed pressure values ​​of gas flow that fall into this potential leak region 1906 for an associated measured flow rate are deemed a potential leak by the first stage evaluation 802 of the leak detection algorithm. These potential leak scenarios are then advanced to the second stage (803-805) of the leak detection algorithm until the condition is determined as either a confirmed leak condition or a no leak condition. By way of example, the second stage evaluation is repeated at successively increasing motor speeds until the combination of measured pressure and measured flow rate is outside the potential leak region 1906 such that the potential leak condition is determined as either a confirmed leak or no leak.

[0275] 24C and 24D, an example graph is shown in which the leak detection algorithm is operating and determining normal operation, i.e., no leaks. In particular, data points A-C represent successive sensed pressure and flow pairs that are evaluated by the leak detection algorithm. Data point A is the operating state of the breathing apparatus in normal operation. The first stage evaluation of the leak detection algorithm determines that this is in the region of possible leaks 1906 and proceeds to a second stage evaluation by increasing the motor speed of the flow generator of the apparatus. Data point B represents the sensed pressure and flow at the higher motor speed. Data point B is still in the region of possible leaks 1906 and so the second stage evaluation repeats by again increasing the motor speed. Data point C represents the sensed pressure and flow at an even higher motor speed, which is outside the region of possible leaks 1906, i.e., no leaks. leak Threshold 1901 and P maybe 1902. Thus, the leak detection algorithm determines the possible leak condition as a no-leak condition and reverts to normal flow control at the original set flow rate, e.g., back to operation at data point A.

[0276] As mentioned above, in some embodiments, the leak detection algorithm optionally includes a threshold adjustment process 807 that executes in scenarios where a possible leak is determined as a no-leak condition. With reference to FIG. 24D, the application and results of this threshold adjustment process 807 are shown. In particular, the threshold adjustment process 807 is configured to adjust the possible leak threshold in order to avoid the leak detection algorithm proceeding in an infinite loop upon return to normal flow control. As shown, the threshold adjustment process 807 adjusts the possible leak threshold P such that the original data point A is no longer considered a possible leak. maybe Change or adjust the threshold 1902. In particular, maybe The threshold value 1902 is the updated or new P maybe The threshold 1902A is adjusted, changed or converted to the new adjusted (lower) P maybeThe threshold 1902A effectively reduces the region of possible leak 1906 so that data point A is no longer considered as a possible leak by the first stage evaluation.

[0277] Referring to FIG. 24E, an example graph is shown where the leak detection algorithm is operating and determining a leak. In this scenario, the combination of measured pressure and flow during normal operation at data point A is deemed a possible leak because it is located in the possible leak region 1906. The first stage evaluation identifies a possible leak condition and proceeds to the second stage evaluation by increasing the motor speed. In this example, the motor speed is increased and the newly measured pressure and flow at the higher motor speed, represented by data point B, is evaluated by the second stage evaluation. Data point B is determined to be within the certain leak threshold (P leak , threshold 1901), the potential leak is confirmed as a confirmed leak and the leak detection algorithm triggers an alarm according to step 806 described above. Once the leak is cleared (e.g. the chamber is reconnected or attached to the respiratory apparatus flow path), the leak detection algorithm allows the respiratory apparatus to return to normal flow control at the original set flow rate. As shown, once the leak is cleared and normal flow control resumes, the leak detection algorithm returns to the first stage leak evaluation. Data point C represents the new measured pressure and flow rate at the original set flow rate after the leak has been cleared. The leak detection algorithm then proceeds according to the process described with respect to Figures 24C and 24D, i.e. data point C is considered a potential leak in the first stage evaluation. The motor speed increases to data point D in the second stage evaluation, which is still a potential leak condition. The motor speed increases to data point E in the second stage evaluation, which is determined as a no leak condition, i.e. normal operation. As described above, P maybe The threshold 1902 is then adjusted, flow control returns to normal, and the leak detection algorithm returns to the first stage of evaluation to continue processing incoming data as the device continues to operate.

[0278] As mentioned above, Pleak Threshold 1901 and P maybe The threshold 1902 curve or line may in some embodiments be derived from a function. By way of example only, for one particular respirator configuration, the equation or function may be of the form:

number

[0279] In some embodiments, the constant k that defines the leakage threshold function 1 ~k 6 One or more of the constants k used in the leak detection algorithm in the therapy and desiccation modes may depend on the mode of operation of the respiratory apparatus and / or the given type of leak being detected. 1 ~k 6 can be the same so that the threshold is the same in both these modes. However, because the flow path characteristics are different with the disinfection kit assembly installed, a different constant k may be used when the leak detection algorithm is operating in disinfection mode. 1 ~k 6 may be employed to define different threshold curves.

[0280] Equations or functions (1) and (2) are provided merely as examples, and it will be appreciated that the leak threshold or function may be customized based on many factors or characteristics associated with, for example, a given respiratory apparatus and / or its mode of operation.

[0281] It will be appreciated that the leak detection algorithm may employ or apply different leak threshold functions or curves depending on the nature or type of leak being detected.

[0282] Drying Mode As mentioned above, the leak detection algorithm may also be configured to operate in one or more non-therapeutic modes. Such a non-therapeutic mode is a "dry mode." The dry mode is typically performed at the end of a therapy session with the respiratory device to dry out the flow path and / or components within the flow path.

[0283] The dry mode is typically initiated after the user or patient removes the patient interface (e.g. nasal cannula), i.e. at some stage after the treatment session has ended, or if the treatment session has otherwise ended via an "off" or "stop" input to the respiratory device's user interface (e.g. touch screen interface). The dry mode operates the flow generator at a constant flow rate, for example 15 L / min to 30 L / min, preferably 25 L / min, or other suitable flow rate. Alternatively, the flow generator may be controlled at a predetermined or configurable constant motor speed. Typically, during the dry mode, the heater plate of the humidifier is turned off or powered down to a low output. Typically, the dry mode operates for a configurable or pre-set period of time to dry the flow path and / or flow path components.

[0284] The leak detection algorithm 800 may operate in dry mode according to the configuration described above with respect to Figures 23-24E. The main difference is that the respiratory device is operating at a preset dry mode flow rate or motor speed according to the dry mode setting, rather than a set therapy flow rate that is specific to the user or patient during a therapy session in therapy mode. Thus, the leak detection algorithm in dry mode will tend to initiate or operate the first stage evaluation at the same preset dry mode flow rate. As with therapy mode operation, the leak detection algorithm is configured to detect leaks during dry mode, such as an "off-chamber" condition (e.g., the chamber is removed or disconnected from the flow path), and will trigger an alarm if such a condition is detected.

[0285] As with the therapy mode, in this example embodiment, the humidification chamber is also an essential part of the device's flow path when in the dry mode. If the humidification chamber is removed or disconnected from the device, the flow path is interrupted and the dry mode will not be able to dry out the patient circuit (e.g., the patient conduit and / or patient interface) because gas flow would leak to the surrounding environment rather than into the patient circuit. Thus, the leak detection algorithm is configured to determine the connection status of the chamber and alert the user to the failure of dry mode operation if the chamber is unplugged or disconnected.

[0286] In this example, the preset dry mode flow rate tends to operate in a low flow region where it is difficult to distinguish between a leak condition (e.g., the chamber is disconnected) and normal operation for reasons previously explained. Thus, the leak detection algorithm can also help to robustly determine a leak condition in the dry mode.

[0287] In this example embodiment, the flow path characteristics in the therapy and desiccation modes are similar, and therefore the same leak threshold function can be employed in the leak detection algorithm.

[0288] Heater plate check to confirm chamber leakage condition In some embodiments, the leak detection algorithm may be enhanced or modified to optionally include a heater plate check that confirms or determines whether the humidification chamber has been removed from the flow path and / or humidification compartment of the respiratory apparatus.

[0289] In a first configuration of the heater plate check, the leak detection algorithm is configured to energize (e.g., apply a power process or procedure to) the heater plate of the humidifier to a set power level (e.g., 100% power or 50% power) for a set period of time. The algorithm monitors the temperature rise of the heater plate based on sensed temperature data or signals generated by a temperature sensor or sensors (e.g., temperature sensors in or associated with the heater plate) configured to sense the temperature of the heater plate. The algorithm can be configured to calculate a rate of change of temperature (i.e., a heating rate of the heater plate) based on the temperature sensor data as the heater plate is energized to the set power level. The rate of change of temperature is then compared to a temperature rate of change threshold. If the rate of change of temperature is greater than the rate of change threshold, a chamber out (e.g., a leak condition) is confirmed or indicated. Alternatively, the algorithm can calculate or determine the time it takes for the temperature of the heater plate to exceed the set temperature threshold. The time taken is then compared to a time threshold. If the time taken falls below a threshold, a chamber disconnect (eg, a leak condition) is identified or indicated.

[0290] In a second configuration of the heater plate check, the leak detection algorithm is configured to energize or heat (e.g., apply a temperature process or procedure to) the heater plate of the humidifier to a preset temperature. Once the preset temperature is reached, power to the heater plate is turned off and the cooling rate of the heater plate is monitored based on temperature data or signals from a temperature sensor or sensors of the heater plate. If the cooling rate is below a cooling rate threshold, a chamber out (e.g., a leak condition) is confirmed or indicated. Alternatively, the algorithm can calculate or determine the time it takes for the temperature of the heater plate to decrease or cool down to a preset lower temperature, such as ambient temperature or some other suitable lower temperature. The time taken is then compared to a time threshold. If the time taken is above the threshold, a chamber out (e.g., a leak condition) is confirmed or indicated.

[0291] The heater plate checks of the first and second configurations are based on the loss of thermal mass of the water in the humidification chamber when the chamber is removed from the humidification unit. In particular, if a water-filled humidification chamber is not in thermal contact with the heater plate, the heater plate will heat up more quickly or cool down more slowly.

[0292] Either or both of the first and second heater plate checks described above may be implemented or performed by the respiratory apparatus controller as part of the leak detection algorithm or as a separate heater plate check algorithm. The output of the heater plate check may be an output indicator or data indicative of a leak condition or a no-leak condition (e.g., chamber on or chamber off). Examples of how the heater plate check may enhance or modify the leak detection algorithm are described below.

[0293] In one first example embodiment, the leak detection algorithm 700, 800 described above can be optionally augmented with either a first configuration heater plate check or a second configuration heater plate check as part of the leak detection algorithm. With reference to FIG. 23, in this first example embodiment, the heater plate check 808 is performed as an additional or supplemental process or leak confirmation step before entering the leak detection situation (704, 806). In particular, if the leak detection process determines a confirmed leak after either the first stage leak evaluation (702, 802) or the second stage leak evaluation (707, 803-805), one or more heater plate checks 808 can be initiated according to either or both of the first or second configurations described above. If one or more heater plate checks confirm a leak condition (e.g., chamber out), the leak detection algorithm proceeds to the leak detection situation (704, 806) and triggers one or more alarm actions. In this example, one or more heater plate checks 808 further verify the leak condition before the algorithm moves to the leak detection stage where alarm action is initiated.

[0294] In a second example embodiment, the leak detection algorithm 700, 800 described above can be modified such that the second stage leak evaluation (706, 803-805) proceeds incrementally at an increased motor speed until the possible leak condition is determined as either a leak condition or a no leak condition, and rather than rechecking the sensed pressure against the leak threshold, one or more heater plate checks are substituted. In this second example embodiment, the leak detection algorithm 700, 800 is modified such that one or more of the heater plate checks are initiated after a possible leak condition is detected in the first stage leak evaluation (702, 802). The one or more heater plate checks are performed to determine the possible leak condition as a definite leak condition or a no leak condition after the possible leak condition is detected. If the one or more heater plate checks confirm the possible leak condition as a definite leak (e.g., the chamber is disconnected), the algorithm proceeds to the leak detection condition (704, 806). If the heater plate check or checks determine that the potential leak is in a no leak condition (e.g., the chamber is connected), the algorithm proceeds to end the second stage leak evaluation according to the previously described steps that apply after determining that no leak is detected. In particular, the leak threshold can be updated (712, 807) and the algorithm returns to normal operation or flow control and returns to the first stage leak evaluation stage to further process the next incoming data stream as the device continues to operate. In this second example embodiment, there is no incremental increase in motor speed in the second stage leak evaluation to determine a possible leak condition, rather, one or more heater plate checks are performed to determine the potential leak as a definite leak condition or a no leak condition.

[0295] The above first and second example embodiments of the heater plate check used in the modified leak detection algorithm may be employed when the respiratory apparatus is operating in either therapy mode or desiccation mode.

[0296] 3.3 Detailed second example of leak detection process-disinfection mode Disinfection kit or assembly The leak detection algorithm may be configured to operate during other non-therapeutic modes of the respiratory apparatus. One such other non-therapeutic mode is a disinfection mode. Briefly, the respiratory apparatus may have an operable disinfection mode configured to disinfect one or more components in the flow path following a treatment session. An example embodiment of a leak detection algorithm operating in a disinfection mode will now be described with reference to Figures 25A-25C. Figure 25A is a simplified schematic diagram of a respiratory apparatus of the type described with respect to Figures 2-21, where, for purposes of illustration, like numbers represent like or similar components.

[0297] In one example embodiment, the disinfection mode of the respiratory apparatus may generally operate in accordance with the principles, instructions and / or configurations described in International Publication No. WO 2007 / 069922, filed December 15, 2006, which is incorporated herein by reference in its entirety.

[0298] Referring to FIG. 25A, in this example embodiment, the disinfection mode of the respiratory apparatus 10 is operable to disinfect an elbow conduit 320 (e.g., a "detachable elbow") in the flow path of the respiratory apparatus. Prior to initiating the disinfection mode, the humidification chamber 300 is removed from the flow path of the respiratory apparatus and the humidification chamber bay or compartment 108. A disinfection kit or assembly is then installed in the flow path. The disinfection kit or assembly includes a disinfection tube or conduit 1100 and a filter or filter assembly 1104. The disinfection tube 1100 may include an integrated heating element 1102. A first end of the disinfection tube 1100 is connected to the gas outlet port 322 and a second end of the disinfection tube is connected to the patient outlet port 344 or the elbow conduit 320. A filter 1104 or filter assembly or component is inserted into or on the gas inlet port 340 of the elbow conduit. In one configuration, the filter 1104 comprises a filter cap or a cap with a filter that engages with, in, or on the gas inlet port 340. In one example, the filter is received and retained in the gas inlet port 340 via a friction fit. The configuration of the disinfection tube and filter may be the same or similar to that described in WO 2007 / 069922. The filter 1104 is configured to filter 1104 the flow of gas forced through and out of the elbow conduit 320. For example, the filter 1104 is configured to filter pathogens and / or particulate matter in the flow of gas generated during a disinfection mode.

[0299] In an alternative configuration, the disinfection kit or assembly comprises an ozone module that can be coupled to the respiratory apparatus. The leak detection method can be configured to detect the removal or misconnection of the ozone module that is part of the disinfection kit. The ozone module can be configured to pump ozone gas through the respiratory apparatus flow path to disinfect the flow path. The ozone module may be required to be used for a set period of time. The described leak detection method is configured to detect the removal of the disinfection module (i.e. the ozone module) before the required time, thereby triggering an appropriate alarm.

[0300] Disinfection Mode The disinfection mode may be selected automatically by the respiratory device controller at the end of a treatment session and / or upon detecting that a disinfection tube has been connected to the flow path, or may be selected manually by the user via the control interface.

[0301] Once the disinfection kit or assembly including the disinfection tube 1100 and the filter 1104 is placed in the flow path, the disinfection mode can be initiated. During the disinfection mode, the respiratory apparatus operates to generate a flow of hot gas through the disinfection tube 1100, the elbow conduit 320, and out the filter 1104 to the atmosphere or surrounding environment for a predetermined period of time in order to disinfect the elbow conduit 320.

[0302] In this example embodiment, during the disinfection mode, the flow generator operates at a constant pre-configured or preset flow rate. In one configuration of the disinfection mode, there is an initial flush phase and a disinfection phase. The initial phase is configured to generate a higher flow rate of gas for a predetermined or minimum period of time to flush out any mobile condensate within the elbow conduit 320. Once the flush phase is completed, the disinfection phase begins, operating at a lower flow rate and higher temperature to disinfect the elbow conduit 320 for a predetermined or minimum period of time.

[0303] In one example configuration, the initial flush phase can include operating the flow generator at a flow rate of about 30 L / min for 20 seconds to 5 minutes, or preferably 30 seconds to 2 minutes. Once the initial flush phase is completed, a disinfection phase or cycle begins, which in this example delivers a flow of hot gas at a flow rate of about 11 L / min. In some embodiments, the disinfection tube 1100 operates to heat the flow of gas generated by the flow generator to an elevated temperature, for example, above 70° C., preferably above about 85° C., more preferably between 85° C. and 95° C., during the disinfection phase or cycle.

[0304] During the disinfection mode, one or more leaks may occur in the flow path. In one example, the filter cap of the filter 1104 of the disinfection kit or assembly may fall off or come loose from the gas inlet port 340 of the elbow conduit 320, for example, due to the device being bumped. In another example, either or both ends of the disinfection tube 1100 may become disconnected or loose from their respective ports 322 and / or 344, causing a leak.

[0305] Leak detection algorithm during disinfection mode The leak detection algorithm of the present disclosure can be configured to operate during disinfection mode to detect one or more types of leaks in the flow path, such as removal or disconnection of the filter 1104 or a component of the filter assembly (e.g., a filter cap) from the elbow conduit 320, and / or disconnection of the disinfection tube from ports 322 and / or 344 or a loose connection to ports 322 and / or 344.

[0306] In one configuration example, the leak detection algorithm can be configured with a leak threshold adjusted to detect whether the filter 1104 or filter component is present (i.e., no leak) or is removed or not connected to the elbow conduit (i.e., a leak condition). If the algorithm detects a leak condition indicating that the filter 1104 or filter component is not connected, an alarm is caused or triggered. The filter 1104 is a critical component for the safe operation of the disinfection mode. The disinfection mode causes very hot gas to exit the elbow conduit 320 at the port 340. The filter 1104 cools the gas and captures any particulate matter as the gas flow exits the elbow conduit 320.

[0307] As mentioned above, the disinfection stage of the disinfection mode tends to operate at a low constant flow rate, where it is difficult to distinguish between a leak condition and normal operation for the reasons mentioned above. Thus, the leak detection algorithm can also help robustly determine a leak condition (e.g., a filter or filter cap is off or not connected) in this disinfection mode.

[0308] With reference to Fig. 25B, the operation of the leak detection algorithm 1000 for the disinfection mode will be described in further detail, by way of example only. The leak detection algorithm 1000 operates in a similar manner to the leak detection algorithm 800 of Fig. 23 and according to the principles of the general example algorithm 700 described with respect to Fig. 22. In this example, the leak detection algorithm 1000 is configured to detect leaks or leak conditions caused by the removal or dislodging of the filter 1104 or a filter component, or the disconnection or leakage of the disinfection tube 1100 of a disinfection kit or assembly.

[0309] In this example embodiment, the leak detection algorithm 1000 begins after the initial flush phase or cycle of the disinfection mode is completed and the disinfection phase or cycle begins in which the device generates a flow of hot gas at a "disinfection flow rate" (e.g., a constant flow rate of about 11 L / min in this example) through the elbow conduit 320. The leak detection algorithm can operate continuously during the disinfection cycle.

[0310] First stage leak assessment In this embodiment, the leak detection algorithm 1000 begins (1001) by proceeding to a first stage leak evaluation in step 1002. In this first stage leak evaluation 1002, a gauge pressure variable (representing the sensed gauge pressure of the gas flow) is compared to a certain leak threshold and a possible leak threshold to determine the leak status of the device, e.g., a leak is detected, a possible leak, or no leak. In this embodiment, one or each condition may be considered to be met or detected based on the respective evaluation criteria being met, as will be described below. In this embodiment, the various evaluations based on comparing the gauge pressure to one or more thresholds may be performed simultaneously or in parallel. In other configurations, the evaluation of which leak conditions are met may be configured to be performed sequentially or in a particular conditional order.

[0311] While operating in the first stage leak assessment 1002, the device can be considered to be in normal disinfection operation with no leaks detected, i.e. in a no leak situation (e.g. filter 1104 or filter cap connected). In this situation or stage, the respiratory device continues normal disinfection operation according to the disinfection flow rate.

[0312] In this embodiment, the algorithm obtains and / or receives input data representing the measured or sensed flow rate of the gas flow, the measured or sensed gauge pressure variables, and the leak threshold value for evaluation. The input data may be obtained according to a particular sampling frequency or continuously as data becomes available from the sensor and / or the main controller and / or the memory of the device. In one configuration, the input data may be a moving average based on a moving window of data. The window of data may be determined based on, for example, a configured period or number of data samples. In one example, the input data may be a 10 second moving average of the sensed flow rate, sensed gauge pressure, and leak threshold value. In another configuration, the input data used by the leak detection algorithm may be the most recent instantaneous data of the sensed flow rate, sensed gauge pressure, and leak threshold value.

[0313] In this embodiment, in step 1002, one of the evaluations made by the algorithm is to determine a certain leak condition. In this embodiment, to determine a certain leak condition, the algorithm compares the gauge pressure variable to a certain leak threshold P (which in this embodiment is a pressure threshold) that represents a certain leak condition. leak Compare with the gauge pressure variable P gauge is the leak threshold P leak If the gauge pressure variable P is less than 1006, then a leak condition is met and the algorithm triggers or generates a leak alarm at 1006. gauge is the threshold for a reliable leak P over a minimum evaluation period of 15 seconds. leak , although it will be appreciated that in other embodiments this period may be adjusted or varied.

[0314] If a leak detection condition is met based on the evaluation in step 1002, the algorithm moves to a leak alarm or leak detection situation or stage at 1006. At the leak detection situation 1006, the algorithm may trigger one or more alarm actions, such as generating an audible, visual or tactile leak detection alarm, indicating that a filter in the disinfection kit or assembly has become dislodged or disconnected from the elbow conduit 320, and / or controlling or stopping the flow rate or motor speed, or other control action.

[0315] In this example embodiment, the algorithm 1000 can be configured to perform one or more alarm actions upon a leak detection condition 1006. In this example embodiment, the algorithm 1000 can perform any one or more of the following example alarm actions: While in the leak alarm condition 1006, the target motor speed at the current time that the leak is detected is frozen so that the motor speed does not change from its current value. Causing or triggering an audible, visual and / or tactile alarm or leak fault notification to the user (e.g., a message or notification on the display of the respiratory apparatus and / or an audible alarm via a speaker or audio device of the respiratory apparatus). For example, the user may be prompted to reconnect the filter 1104 or filter cap onto the elbow 320 and restart the apparatus and / or the disinfection mode.

[0316] Upon reaching a leak detection condition 1006, the algorithm 1000 may also be configured to determine or evaluate whether the leak alarm has been resolved, for example, whether the filter has been reconnected or reinstalled in the elbow conduit 320 of the device. In this embodiment, the algorithm performs an increment 1006 on the pressure variable P gauge The leak threshold P leak Alternatively, the gauge pressure variable P may be continuously evaluated or determined to have eliminated the leak by comparing it to another specific alternate threshold value to confirm elimination of the leak. gaugeover a minimum evaluation period, which is 3 seconds in this embodiment but can be adjusted in other embodiments. leak If the threshold is exceeded, the leak alarm is considered cleared. If the leak alarm is cleared, the algorithm returns to the first stage, leak evaluation 1002, and normal disinfection mode operation can resume or restart according to the set disinfection flow rate. If the gauge pressure variable exceeds the minimum evaluation period, P leak If the threshold is not exceeded, the algorithm remains in the leak detection state 1006 and continues to check for clearance of the leak alarm.

[0317] In this embodiment, one of the other evaluations made by the algorithm in step 1002 is to determine a possible leak condition. In this embodiment, to determine a possible leak condition, the algorithm evaluates the gauge pressure variable P gauge is a possible leak threshold P (which in this embodiment is a pressure threshold) that represents a possible or potential leak condition. maybe In this embodiment, the gauge pressure variable P gauge is the leakage probability threshold P maybe If so, then a possible leak condition is met and the algorithm moves to a second stage leak evaluation (starting at 1003) to determine the identified possible leak as a definite leak or no leak. In this embodiment, the minimum evaluation period is 10 seconds, although this may vary in different embodiments.

[0318] If, based on the above evaluation, neither a confirmed leak condition nor a possible leak condition is met, the algorithm considers that no leak has been detected and remains in the first stage of normal disinfection mode operation, leak evaluation 1002, i.e., the no leak condition remains met (e.g., the disinfection filter is in the elbow conduit) and the device continues with the normal disinfection cycle.

[0319] Second stage leak assessment If the algorithm detects a possible leak condition at 1002, it moves to a second stage of leak assessment beginning at step 1003. In this embodiment, prior to entering the second stage of leak assessment to determine the possible leak as a definite leak or no leak, the algorithm 1000 is configured to store the measured flow rate and sensed pressure variables (e.g., sensed by a flow sensor or other sensing arrangement in the flow path) that occurred prior to entering the second stage of leak assessment at step 1003. In one configuration, the stored values ​​of the measured flow rate and stored sensed pressure variables may represent or be derived from moving averages of these measured or sensed variables, as described above. For example, in one configuration, the algorithm may receive or calculate during operation moving averages of the measured flow rate and sensed pressure variables from which values ​​may be extracted and stored prior to entering the second stage of leak assessment. By way of example, the stored values ​​of the measured flow rate and sensed pressure variables may be used in later algorithm steps including updating and / or adjusting one or more of the leak threshold limits.

[0320] In this embodiment, the second stage leak assessment involves increasing the current target motor speed in a predetermined increment or to a first or next preset higher motor speed at 1003. In this embodiment, the algorithm is configured to increase the motor speed and hold it at the first higher motor speed for a predetermined or maximum period of time. In one configuration, the period may be 4 seconds, but this may vary in alternative embodiments. As will be explained later, during the or each iteration to the next higher motor speed, the higher motor speed is maintained for a configured period of time (e.g., 4 seconds in this example) during which a second stage leak assessment 1004 is performed to attempt to determine the likelihood of a leak as a confirmed leak condition or a no leak condition.

[0321] Upon reaching the higher motor speed after ramping up at 1003, the algorithm 1000 initiates one or more second stage leak assessments at 1004. For example, the updated or new sensed pressure variable P gauge However, new or updated certain P leak and possible P maybe The possible leak condition is compared to thresholds to determine whether the possible leak condition can be determined as a definite leak condition or a no leak condition. Each condition is again determined by the sensed gauge pressure variable P, as described below. gauge The leak thresholds may have their own evaluation criteria to be met based on comparing the leak thresholds to one or more of the leak thresholds.

[0322] In this embodiment, one of the evaluations made by the algorithm in step 1004 is to determine the possible leak condition as a confirmed leak condition. In this embodiment, to determine the possible leak condition, the algorithm uses the updated sensed pressure variable P gauge Updated reliable leak threshold P leak In this embodiment, the new P leak The threshold value of the gauge pressure variable P is updated or determined based at least in part on the flow rate of the gas flow generated at the new higher motor speed and / or the first higher motor speed. gauge is greater than P for the shortest evaluation period (e.g., 3 seconds or another configurable period). leak If it does fall below the threshold, the possible leak condition is confirmed or determined to be a confirmed leak condition and the algorithm proceeds to leak detection state 1006 and generates a leak alarm or initiates one or more alarm actions as previously described.

[0323] In this embodiment, one of the other evaluations made by the algorithm is to determine the possible leak condition as a no-leak condition. In this embodiment, to determine the no-leak condition, the algorithm uses the updated sensed pressure variable P gauge, the updated leak probability threshold P maybe and the updated reliable leakage threshold P leak As explained above, the updated threshold value may be derived or determined based at least in part on the flow rate of the gas flow generated at the new higher motor speed and / or the first higher motor speed. gauge for a minimum evaluation time (e.g., 3 seconds or another configurable period) maybe Above the threshold, P leak If the threshold is exceeded, the likelihood of a leak is determined as no leak was detected and the algorithm returns to the first stage evaluation 1002 and normal operation and / or flow control.

[0324] In this embodiment, upon finishing the second stage leak assessment at 1004 (after resolving a possible leak to no leak), the algorithm may optionally perform a threshold adjustment process at 1007 before returning to step 1002 and normal operation 1001. In this embodiment, the threshold adjustment process 1007 adjusts the P maybe The threshold can be adjusted or lowered. In one configuration, P maybe The threshold value may be adjusted based on an adjustment or correction function 1007 having one or more variables. By way of example, the variables of the adjustment or correction function may include the measured flow rate and sensed pressure variable values ​​stored prior to entering the second stage leak assessment in step 1003, as described above. Additionally, the adjustment or correction function may include one or more additional variables or constants. In one configuration, the adjustment or correction function may have a constant variable that depends on the stored measured flow rate, such that the magnitude of the adjustment may vary depending on the stored measured flow rate. In one configuration, the adjustment or correction function may have a constant variable that depends on the stored measured flow rate, such that the magnitude of the adjustment may vary depending on the stored measured flow rate. In one configuration, the adjustment or correction function may have a constant variable that depends on the stored measured flow rate, such that the magnitude of the adjustment may vary depending on the stored measured flow rate. maybe A constant variable may be configured to make smaller adjustments to the threshold.

[0325] In one embodiment, the threshold adjustment function 1007 is a function of the buffer value P buffer Based at least in part on P maybe In one configuration, P buffer The value may be determined at least in part by the measured flow rate stored after completing the first stage 1002. In another configuration, P buffer The value may be a constant. In one configuration, P maybe The threshold value is derived from a threshold function that depends on the measured flow rate and one or more constants. In this example configuration, the threshold adjustment function is P buffer In another example, the threshold adjustment function is configured to adjust one or more constants of a threshold function based at least in part on the value of P buffer value and P maybe One or more constants of the threshold function are configured to be adjusted based at least in part on the threshold and the measured pressure values ​​stored after completing the first stage 1002 .

[0326] In some configurations of the adjustment or correction function 1007, the P at discrete measured flow rates detected before entering the second stage leak evaluation in 1003 is maybe The threshold may be decreased or tapered by a calculated or predetermined amount. maybe The entire threshold function or curve may be decreased or tapered by a calculated or predetermined amount throughout the operating flow range.

[0327] Returning to the second stage leak assessment at 1004, if neither a sure leak condition nor a no leak condition is met based on the above assessment, then the possible leak condition is considered pending. In this embodiment, if the possible leak condition is pending for a timer-based predetermined period (e.g., 4 seconds in this example, but could be another configurable period), then the second stage leak assessment process repeats, but at a higher motor speed.

[0328] In this embodiment, if the timer expires and a possible leak condition is pending, the algorithm exits 1004 and begins a motor speed check 1005. In this embodiment, the motor speed check 1005 checks the current target motor speed against a preset or configurable motor speed threshold (MAX RPM )

[0329] In this embodiment, in the motor speed check 1005, the current target motor speed is checked to see if it is greater than the motor speed threshold MAX RPM If so, the algorithm terminates the second stage leak evaluation, determines the potential leak as a no leak condition, and returns to the first stage 1002 and normal operation via the threshold adjustment process 1007 described above. The motor speed check 1005 provides an additional exit condition for the algorithm, preventing it from looping infinitely in the second stage and / or increasing the motor speed beyond safety or component thresholds.

[0330] In the motor speed check 1005, it is determined whether the current target motor speed is equal to or lower than the motor speed threshold value MAX. RPM If so, the algorithm loops back to step 1003 and again increases the first higher motor speed to the second or next higher motor speed and repeats the evaluation at 1004 in an attempt to determine the leak probability as a definite leak condition or a no leak condition.

[0331] As shown, the second stage involves continuously or repeatedly incrementally increasing the motor speed by a predetermined amount or to the next predetermined higher motor speed and then evaluating at 1004 until a leak condition is met, a no leak condition is met, or a failed motor speed check is encountered at 1005. As will be appreciated, depending on the evaluation, the second stage of the algorithm may be completed once, twice, or multiple times before terminating back to 1002 (no leak) or 1006 (leak detected).

[0332] It will be appreciated that the motor speed increment in step 1003 may be a preset or configurable increment, or may be incremental to the next highest motor speed in a preset or configurable series or array of preselected discrete higher motor speeds. By way of example only, in one configuration, the motor speed increase in step 1006 is based on incrementally increasing the current motor speed to the next highest motor speed in a series or array that includes motor speeds of 5000 rpm, 6750 rpm, 8500 rpm, 10250 rpm, and 12000 rpm, such that the motor speed increases by 1750 rpm for each cycle or loop of the second stage leak assessment. In this example, the pressure variable is P maybe and P leak There are five possible discrete motor speed steps that are compared to the threshold, although this may be changed to more or fewer steps as required.

[0333] In this embodiment, the leak detection algorithm 1000 repeats upon returning to the first stage leak assessment and normal operation at 1002. In one configuration, the leak detection algorithm operates continuously upon receiving updated real-time sensed pressure variable data from the pressure sensor. In other configurations, the leak detection algorithm may be configured to operate periodically. As previously mentioned, in some configurations, when the device begins or resumes normal disinfection operation, the leak assessment comparison against the leak threshold may be suspended or delayed for a predefined delay period after a predefined event. Such events may include, but are not limited to, the start of a new disinfection, a restart of the device, the resolution of a previous leak alarm at 1006 (e.g., the filter of the disinfection kit is reinstalled or reconnected), or, for example, when normal disinfection operation is resumed at 1002 after the leak alarm is resolved or after the second stage leak assessment is terminated without a detected leak.

[0334] Leakage Threshold in Disinfection Mode The disinfection mode leak detection algorithm 1000 operates in a substantially similar manner as the leak detection algorithm 800 in the normal treatment or desiccation modes, as described above. However, in the disinfection mode, the flow path of the device 10 or system is different because a disinfection kit or assembly component is inserted into the flow path and the humidification chamber and patient circuit are removed or absent. Thus, the leak detection algorithm 1000 relies on different leak thresholds specific to the altered flow path characteristics caused by the disinfection kit or assembly (e.g., disinfection tube 1100 and filter 1104) being in the flow path.

[0335] Referring to FIG. 25C, P leak , P maybe An example of different leak thresholds (e.g., leak curves or functions) for the thresholds is shown and will be further described (these thresholds can be compared to the different leak thresholds described with respect to FIG. 24A used in the treatment mode and desiccation mode).

[0336] Referring to Fig. 25C, a pressure vs. flow plot 1950 (similar to Fig. 24A) is shown to demonstrate the nature of the leak threshold used in the disinfection mode leak detection algorithm. As previously explained, the leak detected in this embodiment is related to the filter component of the disinfection kit being partially or completely removed or disconnected from the flow path of the device, and / or the disinfection tube being disconnected or loosely connected in a leaky manner, and the leak threshold is derived based on the pressure vs. flow characteristics related to gas flow in a device that is operating normally with the disinfection kit components properly installed and a device that is operating in a leaky condition with the filter component removed and / or the disinfection tube being removed or loosely connected in a leaky manner.

[0337] P leak An example threshold function is depicted as a threshold curve or line 1951 on the pressure versus flow graph at 1950. maybeAn example threshold function is depicted as a threshold curve or line 1952 on the pressure versus flow graph at 1950 .

[0338] The function or curve or data represented by 1953 is the sensed pressure characteristic of the gas flow versus the operating flow rate range for a device operating normally in disinfection mode (i.e., no leaks in the disinfection kit and / or flow path). The function or curve or data represented by 1954 is the sensed pressure characteristic of the gas flow versus the operating flow rate range for a device operating in disinfection mode with a leak due to a disconnected disinfection filter and / or a disconnected or loosely connected disinfection tube.

[0339] As shown in the low flow region highlighted at 1955, the pressure vs. flow curves 1953 and 1954 for normal and leaky operation converge in this region, making it difficult to identify a true or definite filter-off or disconnected disinfection tube leak at low flow rates, such as the disinfection mode flow rate, which in this example is about 11 L / min or any other suitable flow rate for the disinfection mode. The leak detection algorithm of the present disclosure provides a means to address this issue by incrementally increasing the motor speed to provide a clearer distinction between the curves to definitively determine a leak (e.g., filter-off) or no leak (e.g., filter-on) condition.

[0340] In this configuration example, leak Threshold 1951 and P maybe The threshold 1952 curve or line can be derived from the same functions or equations (1) and (2) described above in Section 3.2 for the treatment mode and desiccation mode embodiments. As described above, the constants k 1 ~k 6 One or more of the constants k used in the leakage threshold function are different for the leakage curve in the disinfection mode compared to the leakage curves used in the treatment and drying modes. In particular, one or more of the constants k used in the leakage threshold function are different for the leakage curve in the disinfection mode compared to the leakage curves used in the treatment and drying modes. 1 ~k 6is specific to the characteristics of the disinfection mode flow path and / or the particular type of leak that has been detected in the disinfection mode (e.g., a dislodged filter and / or a loose or disconnected disinfection tube).

[0341] Heater plate check to verify disinfection mode setting Optionally, in one embodiment, the controller of the device 10 may be configured to perform one or more of the heater plate checks described in section 3.2 above before starting the disinfection mode. In particular, one or more of the heater plate checks may be performed to check that the chamber is detached or removed, which is a requirement to allow the disinfection mode to operate and the disinfection kit to be installed in the flow path. If the heater plate check indicates that the chamber is still attached, the disinfection mode may not operate.

[0342] Blockage detection in disinfection mode 26, in one embodiment, when operating in the disinfection mode, the device 10 can also be configured to execute or implement an occlusion detection algorithm 1500. The occlusion detection algorithm 1500 may operate alone or in parallel with the leak detection algorithm 1000.

[0343] The blockage detection algorithm 1500 is configured to detect and trigger an alarm if a problematic blockage in the flow path is detected during disinfection mode operation. For example, during disinfection mode, the filter 1104 or disinfection tube 1100 may become fully or partially blocked by condensation or particulate matter, or by a kink in the disinfection tube.

[0344] In this example embodiment, the occlusion detection algorithm 1500 performs an occlusion assessment step 1502 by detecting a gauge pressure variable P gauge The incoming data represents the blocking threshold P block The pressure variable P gaugeis the occlusion threshold P over a predetermined evaluation period. block If the predetermined evaluation period is greater than 1502, the occlusion detection algorithm triggers one or more alarm or fault actions, as shown at 1504. In this example, the predetermined evaluation period is 5 seconds, although any other suitable period may be used. If an occlusion is not detected, the occlusion detection algorithm remains in the evaluation phase 1502 and evaluates the occlusion threshold P to identify any occlusion events or conditions. block For the incoming gauge pressure variable data P gauge Continue to evaluate.

[0345] If an obstruction is detected during the evaluation phase 1502, the obstruction detection algorithm 1500 initiates one or more alarm actions. In this example embodiment, the obstruction detection algorithm triggers an obstruction alarm 1504. The obstruction alarm 1504 may be audible, visual (e.g., a notice or message on a display) and / or tactile. The obstruction alarm must then be cleared by the user (e.g., by cleaning the disinfection tube or filter, or by unkinking the tube, or by otherwise clearing the cause of the obstruction). Once the obstruction is cleared, the user manually restarts the disinfection mode or cycle, as shown at 1506, thereby clearing or removing the triggered obstruction alarm or fault. Once the disinfection mode is restarted, the obstruction detection algorithm 1500 returns to the evaluation phase 1502 and continues to check for any new obstruction conditions as the disinfection cycle operates.

[0346] In this example, the occlusion threshold P block may be derived from an occlusion threshold or function that depends at least in part on the flow rate of the gas flow. By way of example, in this embodiment, the occlusion threshold may be of the form

number

[0347] The occlusion detection algorithm described above may also be used to detect occlusions in the flow path during other modes of the respiratory device, including the therapy mode and / or the drying mode. block The function or curve may be different and depend on the flow path characteristics and configurations specific to those other modes. By way of example, when the device is operating in a therapy mode, the occlusion detection algorithm may include a function or curve that determines the pressure variable P gauge is greater than the occlusion threshold P over a predetermined period of time (e.g., 5 seconds or 10 seconds, or other evaluation period). block The presence of a blockage can be checked and monitored based on whether P block The threshold value is determined based at least in part on the current operating flow rate. block A threshold function or curve is extracted. If an occlusion is detected, an occlusion alarm is generated as described above. The user can then clear the occlusion in the flow path and restart the therapy mode.

[0348] 3.4 Detailed Example of Leak Detection Process - Leak Flow Threshold 27A and 27B, an alternative two-stage leak detection algorithm 3000 is described. Leak detection algorithm 3000 is similar to previously described leak detection algorithms 700, 800 and 1000, except that the leak assessment steps and decisions are based on comparing a measured sensed flow rate or flow rate variable to a leak threshold, rather than comparing a sensed pressure variable to a leak threshold.

[0349] It will be appreciated that the leak detection algorithm 3000 can be adapted and configured to detect leaks in therapeutic and non-therapeutic modes (e.g., drying and disinfection modes) in a manner similar to the algorithms previously described. In particular, the particular leak thresholds used for evaluation can be customized to the particular type of leak being detected and / or the mode of operation of the device 10.

[0350] 27A, there is shown, by way of example only, a detailed flow diagram of one embodiment of a leak detection process or algorithm 3000. It will be appreciated that this example algorithm 3000 utilizes similar general principles of operation as the previous algorithms 700, 800 and 1000 discussed above, and that the features described with respect to those algorithms may also be applied to this algorithm 3000.

[0351] This embodiment of the leak detection algorithm 3000 is configured to detect any of the types of leaks in the flow path discussed above with respect to the treatment and drying modes (e.g., a leak condition caused by a chamber dislodged) and the disinfection mode (e.g., a filter dislodged or a disinfection tube disconnected). The leak threshold employed in the algorithm can be based on the type of leak being detected and / or the operating mode of the device.

[0352] In this embodiment, the leak detection algorithm 3000 begins 3001 during normal operation of the device (e.g., whether in a therapy mode, a drying mode, or a disinfection mode). During normal operation, a flow generator of the device generates a flow of gas at a configurable user-set flow rate for a treatment session in a therapy mode, as described above, or at a pre-defined pre-set or pre-configured flow rate specific to a non-treatment mode, such as a drying mode or a disinfection mode.

[0353] In this embodiment, the algorithm 3000 receives a flow variable that represents or is indicative of a flow signal or data sensed by a flow sensor or sensors configured to sense a flow rate of the gas flow in the flow path. In some configurations, the flow variable may be the raw sensed flow signal or data. In other configurations, the flow variable may be a processed or filtered version of the raw sensed flow signal or data. In one example configuration, the flow variable may be a filtered STPD flow rate.

[0354] In this embodiment, the algorithm 3000 mainly comprises a first stage leak assessment 3002 and a second stage leak assessment including steps and evaluations or decisions of 3003, 3004 and 3005. The first stage leak assessment 3002 may determine whether there is a definite leak, a possible leak, or no leak. The second stage leak assessment is configured to determine the decision of the possible leak from the first stage as either a definite leak or no leak.

[0355] In one embodiment, the algorithm 3000 is suspended or delayed from operation until a predetermined delay period has expired from one or more particular events. These events may include any one or more of the following (depending on the mode of operation): the start of a treatment session, the start of a drying mode, the start of a disinfection cycle, the start of normal operation or flow therapy control, the clearance of a leak alarm or other alarm. In such a configuration, for example, the algorithm 3000 is not operational and cannot generate or trigger a leak alarm during the delay period following one or more selected or configured such events. In other embodiments, the algorithm 3000 may be continuously and immediately operational at the start of a treatment session, a drying session, a disinfection cycle, or when normal flow control resumes after a leak alarm has been cleared.

[0356] First stage leak assessment In this embodiment, after any required delay period has expired, the algorithm 3000 begins (3001) by proceeding to a first stage leak evaluation in step 3002. In this first stage leak evaluation 3002, the flow rate variable is compared to a certain leak threshold and a possible leak threshold to determine the leak status of the device, e.g., leak detected, possible leak, or no leak. In this embodiment, one or each condition may be considered to be met or detected based on the respective evaluation criteria being met, as will be described below. In this embodiment, the various evaluations based on comparing the flow rate to one or more thresholds may be performed simultaneously or in parallel. In other configurations, the evaluation of which leak conditions are met may be configured to be performed sequentially or in a particular conditional order.

[0357] While operating in the first stage of leak assessment 3002, the device can be considered to be in normal operation with no leaks detected, i.e. in a no leak situation. In this situation or stage, the respiratory device continues normal operation and normal flow control at the set flow rate (depending on the operating mode, e.g. treatment mode, drying mode or disinfection mode).

[0358] In this embodiment, the algorithm acquires and / or receives input data representing the measured or detected flow rate and leak threshold of the gas flow to evaluate. The input data may be acquired according to a particular sampling frequency or continuously as data becomes available from the sensor and / or the main controller and / or the memory of the device. In one configuration, the input data may be a moving average based on a moving window of data. The window of data may be determined based on, for example, a configured period or number of data samples. In one example, the input data may be a 10 second moving average of the detected flow rate and leak threshold. In another configuration, the input data used by the leak detection algorithm may be the most recent instantaneous data of the detected flow rate and leak threshold.

[0359] In this embodiment, one of the evaluations made by the algorithm in step 3002 is to determine a certain leak condition. In this embodiment, to determine a certain leak condition, the algorithm uses a flow variable, Flow measured is a definite leak threshold (which in this embodiment is a flow rate threshold) that represents a definite leak condition. leak Compare with the flow variable Flow measured ensures a reliable leak threshold value over the shortest evaluation time. leak If the flow rate variable Flow is less than 3006, then a leak condition is met and the algorithm triggers or generates a leak alarm at 3006. gauge Flow ensures that the leak threshold is met over a minimum evaluation period of 15 seconds. leak , although it will be appreciated that in other embodiments this period may be adjusted or varied.

[0360] If a leak detection condition is met based on the evaluation in step 3002, the algorithm moves to a leak alarm or leak detection state or phase in 3006. In the leak detection state 3006, the algorithm may trigger one or more alarm actions, such as, but not limited to, generating an audible, visual or tactile leak detection alarm, and / or controlling or stopping flow or motor speed, controlling other device components, and / or other control actions, as described above with respect to algorithms 700, 800 and 1000. Depending on the type of leak being detected and / or the operating mode of the device, any of the alarm actions of algorithms 700, 800 and 1000 described above may be employed.

[0361] Upon reaching the leak detection condition 3006, the algorithm 3000 may also be configured to determine or evaluate whether the leak alarm has been resolved, for example, whether the chamber has been reconnected or reinstalled to the device and / or flow path in a treatment or drying mode, or whether the filter has been reconnected or reinstalled in a disinfection mode. In this embodiment, the algorithm may, in 3006, determine whether the flow variable Flow measured Reliable leak threshold flow leak、 Alternatively, the flow variable Flow may be continuously evaluated or determined to have cleared by comparing it to another specific alternate threshold to confirm that the leak has cleared. measured over a minimum evaluation period, which is 3 seconds in this embodiment but can be adjusted in other embodiments. leak If the threshold is exceeded, the leak alarm is considered cleared. If the leak alarm is cleared, the algorithm returns to normal operation or normal flow control with the first stage leak assessment 3002 and the set flow rate for the applicable mode (treatment mode, drying mode or disinfection mode). If the flow rate variable exceeds the minimum evaluation period, the Flow leak If it falls below the threshold, the algorithm remains in the leak detected state 3006 and continues to check for clearance of the leak alarm.

[0362] In this embodiment, one of the other evaluations made by the algorithm in step 3002 is to determine a possible leak condition. In this embodiment, to determine a possible leak condition, the algorithm uses a flow variable, Flow measured is a possible leak threshold, Flow, which represents a possible or potential leak condition (which in this embodiment is a flow rate threshold). maybe In this embodiment, the flow variable Flow measured is greater than the leak probability threshold Flow over the shortest evaluation period. maybeIf so, then a possible leak condition is met and the algorithm moves to a second stage leak evaluation (starting at 1003) to determine the identified possible leak as a definite leak or no leak. In this embodiment, the minimum evaluation period is 10 seconds, although this may vary in different embodiments.

[0363] If, based on the above evaluation, neither a definite leak condition nor a possible leak condition is met, the algorithm considers that no leak is detected and remains in the first stage of normal operation leak evaluation 3002, i.e., the no leak condition remains met and the device continues flow control in normal operation for the applicable operating mode (e.g., treatment mode, drying mode, disinfection mode).

[0364] Second stage leak assessment If the algorithm detects a possible leak condition at 3002, it moves to a second stage of leak assessment beginning at step 3003. In this embodiment, before entering the second stage of leak assessment to determine the possible leak as a definite leak or no leak, the algorithm 3000 is configured to store the measured flow rate and motor speed (e.g., sensed by a flow sensor or other sensing arrangement in the flow path) before entering the second stage of leak assessment at step 3003. In one configuration, the stored values ​​of the measured flow rate and motor speed may represent or be derived from a moving average of these measured or sensed variables, as described above. For example, in one configuration, the algorithm may receive or calculate during operation a moving average of the measured flow rate variables and motor speed from which it may extract and store values ​​before entering the second stage of leak assessment. By way of example, the stored values ​​of the measured flow rate and / or flow rate variables may be used in later algorithm steps including updating and / or adjusting one or more of the leak threshold limits.

[0365] In this embodiment, the second stage leak assessment includes increasing the current target motor speed in a predetermined increment or to a first or next preset higher motor speed in 3003. In this embodiment, the algorithm is configured to increase the motor speed and hold it at the first higher motor speed for a predetermined or maximum period of time. In one configuration, the period may be 4 seconds, but this may vary in alternative embodiments. As will be explained later, during the or each iteration to the next higher motor speed, the higher motor speed is maintained for a configured period of time (e.g., 4 seconds in this example) during which a second stage leak assessment 3004 is performed to attempt to determine the likelihood of a leak as a confirmed leak condition or a no leak condition.

[0366] At the higher motor speed after ramping up in 3003, the algorithm 3000 initiates one or more second stage leak assessments in 3004. For example, the updated or new flow rate variable Flow at the higher motor speed measured However, new or updated flows are available. leak and possible flows maybe The possible leak condition is compared to a threshold value to determine whether the possible leak condition can be determined as a definite leak condition or a no leak condition. Each condition is again determined by a flow variable, Flow, as described below. measured The leak thresholds may have their own evaluation criteria to be met based on comparing the leak thresholds to one or more of the leak thresholds.

[0367] In this embodiment, one of the evaluations made by the algorithm in step 3004 is to determine a possible leak condition as a confirmed leak condition. In this embodiment, to determine a possible leak condition, the algorithm uses the updated flow rate variable, Flow measured Updated reliable leak thresholds leak In this embodiment, a new Flow leakThe threshold value of F is updated or determined based at least in part on the new higher motor speed of the flow generator. measured Flow for a minimum evaluation period (e.g., 3 seconds or another configurable period) leak If the threshold is exceeded, the possible leak condition is confirmed or determined to be a confirmed leak condition and the algorithm proceeds to leak detection state 3006 and generates a leak alarm or initiates one or more alarm actions as previously described.

[0368] In this embodiment, one of the other evaluations made by the algorithm is to determine the possible leak condition as a no leak condition. In this embodiment, to determine the no leak condition, the algorithm uses the updated flow rate variable, Flow measured , the updated leak probability threshold, Flow maybe and updated reliable leak threshold Flow leak As explained above, the updated threshold value may be derived or determined based at least in part on the new higher motor speed of the flow generator. measured Flow for a minimum evaluation time (e.g., 3 seconds or another configurable period) maybe Below the threshold, P leak If it is below the threshold, the likelihood of a leak is determined as no leak detected and the algorithm returns to the first stage evaluation 3002 and normal operation and / or flow control for the current mode of operation.

[0369] In this embodiment, upon finishing the second stage leak assessment in 3004 (after resolving a possible leak to no leak), the algorithm may optionally run a threshold adjustment process in 3007 before returning to step 3002 and normal operation 3001. In this embodiment, the threshold adjustment process 3007 is implemented using Flow maybeThe threshold can be configured to be adjusted or lowered. In one configuration, Flow maybe The threshold may be adjusted based on an adjustment or correction function 3007 having one or more variables.

[0370] By way of example, the variables of the adjustment or correction function may include the stored flow rate variable and / or motor speed, as previously described, that were stored prior to entering the second stage leak assessment in step 3003. Additionally, the adjustment or correction function may include one or more additional variables or constants. In one configuration, the adjustment or correction function may have a constant variable that depends on the stored flow rate variable, such that the magnitude of the adjustment may vary depending on the stored flow rate variable ... maybe A constant variable may be configured to make smaller adjustments to the threshold.

[0371] In one embodiment, the threshold adjustment function 3007 is a function of the buffer value Flow buffer Based at least in part on Flow maybe In one configuration, the Flow buffer The value may depend at least in part on the measured flow variables and / or motor speed stored after completing the first stage 3002. buffer The value may be a constant. In one configuration, Flow maybe The threshold is derived from a threshold function that depends on the motor speed and one or more constants. In this example configuration, the threshold adjustment function is Flow buffer In another example, the threshold adjustment function is configured to adjust one or more constants of a threshold function based at least in part on the value of Flow buffer The step 3002 is configured to adjust one or more constants of the threshold function based at least in part on the value and the flow variable and motor speed values ​​stored after completing the first step 3002.

[0372] In some configurations of the adjustment or correction function 3007, the Flow at discrete motor speeds detected before entering the second stage leak evaluation in 3003 is calculated. maybe The threshold may be increased incrementally by a calculated or predetermined amount. maybe The entire threshold function or curve may be increased by a calculated or predetermined amount over the entire operating flow rate or motor speed range.

[0373] Returning to the second stage leak assessment at 3004, if neither a sure leak condition nor a no leak condition is met based on the assessments described above, then the possible leak condition is considered pending. In this embodiment, if the possible leak condition is pending for a timer-based predetermined period (e.g., 4 seconds in this example, but could be another configurable period), then the second stage leak assessment process repeats, but at a higher motor speed.

[0374] In this embodiment, if the timer expires and a possible leak condition is pending, the algorithm exits 3004 and begins a motor speed check 3005. In this embodiment, the motor speed check 3005 checks the current target motor speed against a preset or configurable motor speed threshold (MAX RPM )

[0375] In this embodiment, the motor speed check 3005 checks whether the current target motor speed is greater than the motor speed threshold MAX RPM If so, the algorithm terminates the second stage leak evaluation, determines the potential leak as a no leak condition, and returns to the first stage 3002 and normal operation via the threshold adjustment process 3007 described above. The motor speed check 3005 provides an additional exit condition for the algorithm, preventing it from looping infinitely in the second stage and / or increasing the motor speed beyond safety or component thresholds.

[0376] In the motor speed check 3005, it is determined whether the current target motor speed is equal to or greater than the motor speed threshold value MAX. RPM If so, the algorithm loops back to step 3003 and again increases the first higher motor speed to the second or next higher motor speed and repeats the evaluation again at 3004 in an attempt to determine the leak probability as a definite leak condition or a no leak condition.

[0377] As shown, the second stage involves continuously or repeatedly incrementally increasing the motor speed by a predetermined amount or to the next predetermined higher motor speed and then evaluating at 3004 until a leak condition is met, a no leak condition is met, or a motor speed check fails at 3005. As will be appreciated, depending on the evaluation, the second stage of the algorithm may be completed once, twice, or multiple times before terminating back to 3002 (no leak) or 3006 (leak detected).

[0378] It will be appreciated that the motor speed increment in step 3003 may be a preset or configurable increment, or may be incremental to the next highest motor speed in a preset or configurable series or array of preselected discrete higher motor speeds. By way of example only, in one configuration, the motor speed increase in step 806 is based on incrementally increasing the current motor speed to the next highest motor speed in a series or array that includes motor speeds of 5000 rpm, 6750 rpm, 8500 rpm, 10250 rpm, and 12000 rpm, such that the motor speed increases by 1750 rpm for each cycle or loop of the second stage leak assessment. In this example, the flow rate variable is Flow maybe and Flow leak There are five possible discrete motor speed steps that are compared to the threshold, although this may be changed to more or fewer steps as required.

[0379] In this embodiment, the leak detection algorithm 3000 repeats upon returning to the first stage of leak assessment and normal operation at 3002. In one configuration, the leak detection algorithm operates continuously as it receives updated real-time flow variable data from the controller. In other configurations, the leak detection algorithm may be configured to operate periodically. As previously mentioned, in some configurations, when the device begins or resumes normal operation, the leak assessment comparison against the leak threshold may be suspended or delayed for a predefined delay period after a predefined event. Such events may include, but are not limited to, the start of a new therapy session or a new user-set flow rate, the clearance of a previous leak alarm at 3006, or when normal operation or flow control is resumed at 3002, for example, after the leak alarm has been cleared or after the second stage of leak assessment has been terminated with no leak detected.

[0380] Leak Threshold An example of a leak threshold associated with the leak detection algorithm 3000 will now be further described. As discussed, a reliable leak threshold, Flow leak and the leakage probability threshold, Flow maybe can be based on the measured motor speed operating at the time of the evaluation comparison. In one configuration, Flow leak and Flow maybe The threshold value may depend on or be a function of at least the sensed motor speed of the flow generator, and optionally one or more other variables or operating characteristics of the device and / or the gas flow. leak and Flow maybe The thresholds may be functions, threshold curves or lines, or may be provided in the form of look-up tables. Thresholds can be extracted from the functions, threshold curves or lines, or look-up tables at each stage of the leak detection algorithm based on at least the current sensed motor speed of the flow generator, as well as any other variables.

[0381] 27B, a plot 3050 of motor speed versus flow is shown to demonstrate the nature of the leak threshold used in the leak detection algorithm. As previously explained, the leak threshold is derived based on the motor speed versus flow characteristics associated with gas flow in a device operating normally without a leak (e.g., with the chamber on in treatment or drying mode, or with the filter on in disinfection mode) and with a leak (e.g., with the chamber off in treatment or drying mode, or with the filter off in disinfection mode).

[0382] Flow leak An example threshold function is plotted as a threshold curve or line 3051 on the motor speed vs. flow graph at 3050. maybe An example threshold function is depicted as a threshold curve or line 3052 on the motor speed vs. flow rate graph at 3050. As shown, in this embodiment, the motor speed and flow rate characteristics have a linear (e.g., straight line) relationship. The threshold lines 3051 and 3052 vary depending on the mode of operation, for example, a treatment mode and a drying mode may have similar threshold lines, while a disinfection mode has a different threshold line.

[0383] The function or curve or line or data represented at 3053 is the sensed motor speed of the flow generator versus the operating flow range for a device operating normally without leaks (however, this line or characteristic is dependent on the mode of operation). The function or curve or line or data represented at 3054 is the sensed motor speed of the flow generator versus the operating flow range for a device operating with a leak (e.g., due to a chamber being disconnected or a filter being disconnected depending on the mode of operation). The leak data line 3054 varies depending on the mode of operation. As shown in the low flow region highlighted at 3056, the motor speed versus flow lines 3053 and 3054 for normal and leaky operation converge in this region, making it difficult to identify a true or certain leak condition (e.g., a chamber being disconnected or a filter being disconnected) at low flow rates. The leak detection algorithm of the present disclosure provides a means to address this issue by incrementally increasing the motor speed to provide a clearer distinction between the curves to definitively determine a leak condition or no leak condition.

[0384] In an alternative embodiment, the heater plate check process and configuration and alternatives described in section 3.2 may also be applied to the algorithm 3000.

[0385] 4. Example Embodiments of a Single Threshold Leak Detection Process In another embodiment, a single threshold leak detection process or algorithm may be implemented by the controller of the device. In this single threshold leak detection process, the algorithm is configured to compare either an incoming sensed pressure variable or an incoming flow rate variable, which represents the sensed pressure characteristics of the gas flow in the flow path of the device, to a single leak threshold. In this embodiment, the leak threshold may be a leak pressure threshold in an embodiment using an incoming sensed pressure variable, or a leak flow rate threshold in an embodiment using an incoming flow rate variable. The single leak threshold may be represented by a threshold curve, function, equation, model, or look-up table that defines thresholds over all or at least a portion of the operating flow range of the device, similar to the leak thresholds discussed with respect to the previous embodiment. As with the previous embodiment, the leak threshold used in the evaluation to determine whether there is a possible leak condition, a confirmed leak condition, or a no-leak condition depends primarily on or is a function of the measured flow rate and / or motor speed operating at the time of the evaluation, and optionally one or more other variables representing the operating characteristics of the device and / or the gas flow.

[0386] The single threshold leak detection method or process is also a two-stage process, as in the previous embodiment. In this embodiment, when the device is operating normally, the leak detection algorithm operates in a first stage of leak assessment, checking or comparing the sensed pressure or flow variable with a leak threshold associated with the current operating conditions (e.g., flow rate and / or motor speed, etc.). Based on the comparison, the leak detection algorithm determines that a no-leak condition is met or a possible leak condition is met. In one embodiment, if the sensed pressure variable is above the leak pressure threshold or the flow variable is below the leak flow threshold, the algorithm considers there is no leak (i.e., no-leak condition is met) and continues normal operation and continues with the first stage leak assessment check. If the sensed pressure variable is below the leak pressure threshold or the flow variable is above the leak flow threshold, the algorithm considers there is a possible leak, i.e., a possible leak condition is met.

[0387] If a possible leak condition is met from the first stage leak assessment, the algorithm moves to a second stage leak assessment and determines the possible leak condition as either a no leak condition or a sure leak condition. In this second stage leak assessment, the algorithm is configured to increase / increase the operating flow rate and / or motor speed of the device to a higher flow rate and / or motor speed. The increase / increase in the flow rate and / or motor speed can be a predetermined increment, a dynamically determined increment, or an increment determined by a function that depends on one or more variables, such as the current operating condition of the device (e.g., flow rate and / or motor speed). At the higher flow rate and / or motor speed, the algorithm is configured to check or compare the updated or new sensed pressure variable or new flow rate variable with the updated respective leak threshold value associated with the higher flow rate and / or motor speed. If the new sensed pressure variable is higher than the new leak pressure threshold value or the new flow rate variable is lower than the new leak flow rate threshold value, the possible leak is determined as a no leak condition and the algorithm returns to the first stage leak assessment and normal operation. If the new detected pressure variable is lower than the new leak pressure threshold or the new flow variable is above the new leak flow threshold, the possible leak is determined or confirmed as a confirmed leak condition and the algorithm may transition to a leak detection status or state and perform one or more alarm actions, as in the previous embodiment.

[0388] In this embodiment, the leak detection algorithm is a two-stage approach of an initial leak determination under normal operating conditions, followed by a second confirmatory leak determination at higher operating conditions (e.g., higher flow rates and / or motor speeds) where distinguishing between leak and no-leak conditions is easier or can be achieved with greater confidence based on a single leak threshold function.

[0389] term Unless the context clearly requires otherwise, throughout this specification and claims, the words "comprise," "comprising," and the like are to be interpreted in an inclusive sense, i.e., "including but not limited to," as opposed to an exclusive or exhaustive sense.

[0390] Although the present disclosure has been described with respect to several embodiments and examples, those skilled in the art will understand that the present disclosure extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses, as well as obvious modifications and equivalents thereof. In addition, while several variations of the embodiments of the present disclosure have been shown and described in detail, other modifications that are within the scope of the present disclosure will be readily apparent to those skilled in the art. It is also contemplated that various combinations or subcombinations of certain features and aspects of the embodiments can be made and still be within the scope of the present disclosure. For example, features described above in connection with one embodiment can be used with different embodiments described herein, and the combinations will still be within the scope of the present disclosure. It should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for each other to form various aspects of the embodiments of the present disclosure. Therefore, it is not intended that the scope of the disclosure herein should be limited by the specific embodiments described above. Thus, unless otherwise specified or clearly contradictory, each embodiment of the present invention can include, in addition to its essential features described herein, one or more features as described herein from each of the other embodiments of the present invention disclosed herein.

[0391] It should be understood that features, materials, properties or groups described in connection with a particular aspect, embodiment or example are applicable to any other aspect, embodiment or example described in this section or elsewhere in this specification, unless inconsistent. All features disclosed in this specification (including the accompanying claims, abstract and drawings) and / or all steps of any method or process so disclosed may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive. Protection is not limited to the details of any of the foregoing embodiments. Protection extends to any novel or any novel combination of features disclosed in this specification (including the accompanying claims, abstract and drawings) or any novel or any novel combination of steps of any method or process so disclosed.

[0392] In addition, some features described in the present disclosure in the context of separate embodiments can also be implemented in a single embodiment in combination. Conversely, various features described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features may be described above as acting in some combinations, in some cases, one or more features from a claimed combination can be excluded from the combination, and the combination can be claimed as a subcombination or a variation of the subcombination.

[0393] Additionally, although operations may be depicted in the figures or described in the specification in a particular order, such operations need not be performed in the particular order or sequential order depicted, or all of the operations need not be performed, to achieve desirable results. Other operations not shown or described may also be incorporated in the example methods and processes. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the described operations. Additionally, operations may be rearranged or reordered in other embodiments. Those skilled in the art will appreciate that in some embodiments, the actual steps performed in the illustrated and / or disclosed processes may differ from those shown in the figures. Depending on the embodiment, some of the steps described above may be removed and other steps may be added. Additionally, the features and attributes of certain embodiments disclosed above may be combined in different ways to form additional embodiments, all of which are within the scope of the present disclosure. Additionally, the separation of various system components in the above-described embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the described components and systems may generally be integrated together in a single product or packaged in multiple products.

[0394] For purposes of this disclosure, certain aspects, advantages, and novel features have been described herein. Not all of these advantages are necessarily achieved in accordance with any particular embodiment. Thus, for example, one skilled in the art will recognize that the present disclosure can be embodied or performed in a manner that achieves one advantage or group of advantages as taught herein, without necessarily achieving other advantages as may be taught or suggested herein.

[0395] Conditional language such as "can," "may," "could," or "may," unless specifically stated otherwise or understood otherwise within the context in which it is used, is intended to generally convey that some embodiments include certain features, elements, and / or steps and other embodiments do not include certain features, elements, and / or steps. Thus, such conditional language is generally not intended to imply that the features, elements, and / or steps are in any way required by one or more embodiments, or that one or more embodiments necessarily include logic that determines, with or without user input or instruction, whether or not those features, elements, and / or steps should be included or performed in any particular embodiment.

[0396] As used herein, degree words such as "approximately," "about," "generally," and "substantially" refer to a value, amount, or characteristic that is close to a stated value, amount, or characteristic that still performs a desired function or achieves a desired result. For example, the terms "approximately," "about," "generally," and "substantially" can refer to an amount that is within less than 10%, less than 5%, less than 1%, less than 0.1%, and less than 0.01% of the stated amount.

[0397] The scope of the disclosure is not intended to be limited by any given disclosure of embodiments in this section or elsewhere herein, but may be defined by the claims, as presented in this section or elsewhere herein, or as presented in the future. The claim language should be interpreted broadly based on the language employed in the claims, and should not be limited to the examples described herein or during prosecution of this application, which examples should be interpreted as non-exclusive.

Claims

1. A breathing apparatus configured to provide a gas flow to a user for respiratory therapy, a motor-driven flow generator operable to generate the gas flow, a flow path for the gas flow to a gas outlet of the breathing apparatus through the breathing apparatus, a humidifier operable to heat and humidify the gas flow, the humidifier including a removable humidification chamber within the flow path, a pressure sensor configured to generate a pressure variable representative of a sensed pressure characteristic of the gas flow within the flow path, a controller operatively connected to the flow generator and operable to control the flow rate of the gas flow by controlling the motor speed of the flow generator, during operation, starting a first stage of leak evaluation including comparing the pressure variable with a first leak threshold, the first leak threshold representing a state where there may be a leak, starting a second stage of leak evaluation if the pressure variable falls below the first leak threshold, thereby indicating a potential leak, the second stage of leak evaluation including increasing the motor speed of the flow generator from the current motor speed to a higher motor speed, comparing a new pressure variable at the higher motor speed with the first leak threshold and a second leak threshold, the second leak threshold representing a certain leak state, generating a leak alarm and ending the second stage of leak evaluation if the new pressure variable falls below the second leak threshold, thereby confirming the potential leak as a certain leak, or ending the second stage of leak evaluation without generating the leak alarm if the new pressure variable exceeds the first leak threshold and the second leak threshold, thereby determining that there is no leak, or repeating the second stage of leak evaluation at one or more further higher motor speeds until the potential leak is confirmed as a leak or determined as no leak, including starting, a controller configured to execute a leak detection process for detecting a leak within the flow path, a breathing apparatus comprising.

2. The leak evaluation of the first stage includes comparing the pressure variable with the first leak threshold and the second leak threshold, and the controller is configured to start the leak evaluation of the second stage when the pressure variable is below the first leak threshold and above the second leak threshold, thereby indicating a possibility of leakage. And / or, The leak evaluation of the first stage includes comparing the pressure variable with the second leak threshold, and the controller is configured to generate the leak alarm when the pressure variable is below the second leak threshold. The breathing apparatus according to claim 1.

3. The controller is configured to repeat or continue the leak evaluation of the first stage during normal operation until an end condition occurs. Preferably, the end condition includes generating the leak alarm or starting the leak evaluation of the second stage to determine the possibility of leakage as a definite leak or no leak. The breathing apparatus according to claim 1.

4. In the leak evaluation of the second stage, increasing the motor speed of the flow generator includes increasing the motor speed in set increments to a higher motor speed or to the next higher motor speed from a predetermined series or array of higher motor speeds. Preferably, in the leak evaluation of the second stage, the controller is configured to hold the flow generator at the higher motor speed for a predetermined period while comparing the new pressure variable with the first and / or second leak thresholds to determine the possibility of leakage as a definite leak or no leak. The breathing apparatus according to claim 1.

5. The controller is configured to repeat the leak evaluation of the second stage at the next further higher motor speed when the possibility of leakage is not confirmed as a leak and not determined as no leak at the current higher motor speed within a predetermined period. The breathing apparatus according to claim 1.

6. The controller is configured to end the leak evaluation of the second stage in response to a comparison of the motor speed of the current motor speed with a motor speed threshold. Preferably, the controller is configured to end the second-stage leak evaluation if the higher motor speed at the current time, which is operating during the second-stage leak evaluation, does not fall below a motor speed threshold. The breathing apparatus according to claim 1.

7. The controller is configured to adjust the first leak threshold if the second-stage leak evaluation ends without generating the leak alarm. Preferably, the controller is configured to adjust the first leak threshold by reducing the first leak threshold related to the flow rate and / or motor speed operating during the first-stage leak evaluation. The breathing apparatus according to claim 1.

8. The values of the first and second leak thresholds are at least partially determined by or are a function of the flow rate and / or motor speed operating at the time of comparison. And / or The first and second leak thresholds are extracted from respective pressure-flow characteristic curves and / or a representative look-up table specifying thresholds for ranges of flow rate and / or motor speed. The breathing apparatus according to claim 1.

9. The controller is configured to determine each comparison evaluation of the pressure variable with respect to the first and / or second leak thresholds based on whether the pressure variable consistently exceeds or falls below the threshold over each respective shortest evaluation period during the leak evaluation phase. Preferably, each shortest evaluation period is determined by a predetermined comparison evaluation and / or a predetermined leak evaluation phase. And / or Preferably, the shortest evaluation period related to the comparison evaluation in the second-stage leak evaluation is shorter than the shortest evaluation period related to the comparison evaluation in the previous first-stage leak evaluation. The breathing apparatus according to claim 1.

10. The controller is configured to initiate one or more alarm operations when generating the leak alarm. Preferably, the alarm operation includes fixing the flow rate and / or motor speed of the flow generator to the current operating settings. And / or Preferably, the alarm operation includes generating a leak notification or indication on the display of the device. The breathing apparatus according to any one of claims 1 to 9.

11. The leak alarm indicates that the removable humidification chamber has been at least partially or entirely removed or disconnected from the flow path of the apparatus, and / or, The leak alarm indicates that the patient circuit has been at least partially or entirely removed or disconnected from the gas outlet of the apparatus. The respiratory device according to any one of claims 1 to 9.

12. The controller is operable to detect one or more different types of leaks in the flow path of the apparatus, and each different type of leak has its own respective first and second leak thresholds. The respiratory device according to any one of claims 1 to 9.

13. After the leak alarm is generated, the controller is configured to maintain the leak alarm until the pressure variable rises above the second leak threshold or an alternative leak elimination threshold over a minimum period of time, and / or, After the leak alarm is generated, the controller is configured to disable the leak alarm and return to normal operation if the pressure variable rises above the second leak threshold or an alternative leak elimination threshold over a minimum period of time. The respiratory device according to any one of claims 1 to 9.

14. The controller is configured to operate the leak detection process continuously without modification over the entire or a substantial portion of the operating flow range of the apparatus, and / or, The respiratory device comprises a patient circuit including a patient interface connected to the gas outlet, and the controller is configured to operate the leak detection process continuously without modification for different types or sizes of patient interfaces. The respiratory device according to any one of claims 1 to 9.

15. The humidifier of the respiratory device further comprises a heater plate operable to heat the humidification chamber, and the controller is further configured to perform a heater plate check process to further confirm or verify the certain leak identified in the second-stage leak assessment before generating the leak alarm. Preferably, the heater plate check process applies a power or temperature process to the heater plate and evaluates the heating rate and / or cooling rate of the heater plate against one or more thresholds based on a temperature sensor associated with or on the heater plate, thereby determining the presence or absence of a humidification chamber in thermal contact with the heater plate, the absence of the humidification chamber confirming a positive leak condition, the breathing apparatus according to any one of claims 1 to 9.

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