Respiration device for providing bubble cpap

Abstract

To provide a respiration system including a flow generator capable of providing bubble CPAP therapy by controlling the pressure of a flow of gas delivered to a patient.SOLUTION: A controller of a respiration system can control a motor speed of its flow generator so as to control the pressure of the flow of gas. The controller can also detect presence of bubbling and / or possible leaks in a gas pathway of the system. The respiratory system can include a high flow respiratory system.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present disclosure relates to methods and systems for delivering respiratory flow therapy to a patient. In particular, the present disclosure relates to the use of a flow generator to deliver bubble CPAP therapy. [Background technology]

[0002] Respiratory support devices are used to deliver a flow of gas to a user or patient in a variety of environments, such as hospitals, medical facilities, home care, or domestic environments. Respiratory support or respiratory therapy devices (collectively, "respiratory devices" or "respiratory equipment") may be used to deliver supplemental oxygen or other gases along with the gas flow, and / or humidification devices may be used to deliver heated and humidified gas. Respiratory devices 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] Bubble Continuous Positive Airway Pressure (CPAP) is a form of respiratory therapy in which a patient (typically an infant) is provided with a flow of gas through a patient interface. The flow of gas is typically provided by a gas source in the wall of a hospital or clinic, or may be provided by a cylinder of compressed air and / or oxygen, for example during transport. The patient interface is connected to two conduits, an inhalation conduit and an exhalation conduit. The inhalation conduit provides gas to the patient. The exhalation conduit provides a path for exhaled gas from the patient. The exhalation conduit is in communication with a pressure regulator, which is used to set the pressure. The pressure regulator may be a chamber with a column of water in which an end portion of the exhalation conduit is submerged. Exhaled gas is released into the pressure regulator. The exhaled gas being released into the water bubbles into the water, creating a bubbling effect. The patient interface is typically configured to form a seal with the patient's mouth and / or nose. Examples of tight-fitting patient interfaces may include a nasal mask, an oral mask, a full face mask, nasal pillows, or a cannula with tight-fitting nasal prongs.

[0004] In some locations, for example in some developing countries or remote areas, a wall source may not be available. The present disclosure provides systems and methods for providing bubble CPAP therapy that include a flow generator instead of and / or optionally in addition to a wall source. The flow generator may also include an integrated humidifier for heating and humidifying the flow of gas. An example of a flow generator with an integrated humidifier is a high-flow breathing apparatus. A heated breathing tube may also be used with a high-flow breathing apparatus to deliver the flow of gas from the humidifier to the patient interface. The flow generator may also include an integrated blender to provide supplemental gas to the gas flow. The flow generator is preferably a flow generator that draws in ambient gas, e.g., ambient air, rather than being connected to a gas source, e.g., a gas tank or a wall source. The blender allows one or more supplemental gases to be mixed with the drawn-in ambient gas.

[0005] High-flow breathing devices can provide a variety of modes of therapy, such as, but not limited to, high-flow therapy (also known as nasal high-flow therapy or tracheal high-flow therapy), CPAP, bi-level, and bubble CPAP, allowing patients to avoid having to switch to a different breathing device when switching to a different mode of respiratory therapy (e.g., when the patient's condition changes).

[0006] The high-flow respiratory device can operate in a bubble CPAP therapy mode or a nasal high-flow therapy mode (as described in more detail below). Additionally or alternatively, the high-flow respiratory device can also operate in other high-flow therapy modes, such as tracheal high-flow or other high-flow. Nasal high-flow is delivered through a nasal interface. Tracheal high-flow can be delivered by a tracheal interface. Other interfaces, such as an oral interface, may also be possible to provide high-flow to the airways via an oral passage. The described respiratory device can operate in a high-flow therapy mode or a bubble CPAP mode.

[0007] The high flow breathing apparatus may operate as a flow controlled device (e.g., the high flow breathing apparatus may control a blower motor to achieve a target flow), as described in more detail below. The target flow may be a constant flow rate. The target flow may be set by the user or may be based on the device being in bubble CPAP therapy mode or nasal high flow therapy mode. In one example, the controller may include predefined target flow rates for the bubble CPAP therapy mode and the nasal high flow therapy mode. The predefined target flow rates may be stored in a memory of the controller.

[0008] When operating in bubble CPAP mode, the high flow breathing apparatus may control the motor speed of its flow generator, which may be a blower, to deliver a constant flow rate (including a substantially constant flow rate). The breathing apparatus may monitor the pressure in the breathing circuit (also called the breathing tube or inhalation conduit) or in the flow path of the breathing apparatus, and may adjust the target motor speed if the pressure exceeds this limit. The breathing apparatus may also replace the pressure relief valve in conventional bubble CPAP systems with software control to provide better pressure control over the gas flow. The breathing apparatus may provide multiple alarms and monitoring. For example, the breathing apparatus may determine if there is an irregular amount of leakage, blockage, intermittent bubbling, suggested and / or automatic flow rate changes, a flow rate that does not meet the required inhalation volume when the pressure exceeds a threshold, and / or detect if there is bubbling. The high flow breathing apparatus may also further limit the generated pressure so that the pressure delivered to the patient is below a pressure limit value. In one example, in bubble CPAP mode, the flow rate may be high.

[0009] The terms respiratory apparatus and respiratory equipment may be used interchangeably to describe and define the same item.

[0010] The breathing apparatus or breathing device may be part of a breathing system that includes one or more additional components (eg, an inhalation tube, an exhalation tube, a bubbler), as described in more detail below.

[0011] In some forms, a respiratory device configured to deliver respiratory therapy to a patient via a patient interface may include a controller; a blower including a motor, where a motor speed of the blower may be controlled by the controller; a pressure sensor configured to measure a pressure of a gas flow downstream of the blower; the controller may be configured to: compare the pressure to a threshold; in response to the pressure exceeding the threshold, reduce a target motor speed of the blower; and in response to the pressure being equal to or less than the threshold, control the motor speed to achieve a target flow rate.

[0012] In some forms, a respiratory device configured to deliver respiratory therapy to a patient via a patient interface, the device may include: a controller; a blower including a motor, a blower motor speed being controlled by the controller to a target motor speed; a pressure sensor configured to measure a pressure of a gas flow downstream of the blower; the controller configured to: compare the pressure to a threshold; in response to the pressure being above the threshold, reduce a target motor speed of the blower; and in response to the pressure being equal to or less than the threshold, adjust the target motor speed to achieve a target flow rate.

[0013] In some forms, a respiratory device configured to deliver respiratory therapy to a patient via a patient interface, the device may include: a controller; a blower controlled by the controller; a pressure sensor configured to measure a pressure of a gas flow downstream of the blower; the controller configured to: compare the pressure to a threshold; if the pressure is above the pressure threshold, control the blower to reduce the pressure below the threshold; and if the pressure is at or below the threshold, control the blower to achieve a target flow rate.

[0014] In some embodiments, the blower includes a motor.

[0015] In some forms, the blower is controlled by controlling one or more of: a motor speed, a motor current, and / or a motor voltage to a target motor speed, a target motor current, and / or a target motor voltage.

[0016] In some forms, the target motor speed may be decelerated at a constant rate. In some forms, the target motor speed may be decelerated at a variable rate.

[0017] In some forms, the controller may be configured to continually reduce the target motor speed until the pressure falls below a threshold value.

[0018] In some forms, the pressure sensor may be an absolute pressure sensor.

[0019] In some forms, the pressure may be measured by taking the difference between a reading of a pressure sensor and a reading of a second pressure sensor, both of which are absolute pressure sensors.

[0020] In some forms, the pressure sensor may be a gauge pressure sensor configured to take the difference between ambient pressure and the pressure downstream of the blower.

[0021] In some forms, the controller can be configured to receive an input of a target flow rate.

[0022] In some forms, the target flow rate may be set by the user.

[0023] In some forms, the device may include an oxygen inlet that is separate from the ambient air inlet.

[0024] In some forms, the blower can be configured to mix ambient air from the ambient air inlet with oxygen from the oxygen inlet.

[0025] In some forms, FdO2 may depend in part on the target flow rate.

[0026] In some forms, the controller may be further configured to control the FdO2 by controlling the opening of the oxygen inlet valve.

[0027] In some configurations, the target flow rate may be constant.

[0028] In some forms, the device may be coupled to a bubbler, and the controller may be configured to detect bubbling by monitoring changes in the flow parameter signal.

[0029] In some forms, the flow parameter signal may include a flow signal, a pressure signal, or a combination thereof.

[0030] In some forms, the change may be a change in amplitude of the flow parameter signal from a threshold value.

[0031] In some forms, the changes may be analyzed in the frequency domain.

[0032] In some forms, the controller may be configured to output a warning in response to a lack of foaming for a predetermined period of time.

[0033] In some forms, the controller may be configured to output one or more of the following warnings based on whether foaming is detected: leak, blockage, intermittent foaming, suggested and / or automatic flow rate changes, and / or a flow rate that does not meet the required inspiratory volume.

[0034] In some forms, the device may further include a humidification chamber.

[0035] In some configurations, the device may further include one or more flow sensors.

[0036] In some forms, the device may be a high flow respiratory device.

[0037] In some embodiments, the system includes a battery.

[0038] In some configurations, the battery is the primary power source for the device.

[0039] In some configurations, the battery is a secondary power source for the device.

[0040] In some embodiments, the device includes a motor speed limit.

[0041] In some embodiments, the motor speed limit is based on the ambient pressure or an ambient pressure.

[0042] In some configurations, the system may include any combination of the devices as described above. The system may further include an inhalation conduit for providing a flow of gas to the patient interface.

[0043] In some forms, the patient interface may form a seal on or around the patient's face.

[0044] In some forms, the patient interface may be configured to connect to an exhalation conduit.

[0045] In some forms, the exhalation conduit may be configured to connect to a bubbler.

[0046] In some forms, the system may not include a pressure relief valve between the blower and the patient interface.

[0047] In some forms, a method of providing bubble CPAP via a patient interface coupled to a respiratory device including a flow generator, the flow generator including a motor in electrical communication with a controller of the respiratory device, the method may include measuring a pressure of a gas flow downstream of the flow generator based on readings from a pressure sensor; comparing the pressure to a threshold; in response to the pressure being above the threshold, reducing a target motor speed of the flow generator; and in response to the pressure being equal to or below the threshold, controlling the motor speed to achieve a target flow rate.

[0048] In some forms, a method of providing bubble CPAP via a patient interface coupled to a respiratory device including a flow generator, the flow generator including a motor in electrical communication with a controller of the respiratory device, the controller configured to control the motor to a target motor speed, the method may include measuring a pressure of a gas flow downstream of the flow generator based on a reading from a pressure sensor; comparing the pressure to a threshold; in response to the pressure being above the threshold, reducing the target motor speed of the flow generator; and in response to the pressure being equal to or below the threshold, adjusting the target motor speed to achieve the target flow rate.

[0049] In some forms, a method of providing bubble CPAP via a patient interface coupled to a respiratory device including a flow generator, the flow generator including a blower, and optionally the blower including a motor in electrical communication with a controller of the respiratory device, the controller configured to control the motor to a target motor speed, the method may include measuring a pressure of a gas flow downstream of the flow generator based on a reading from a pressure sensor; comparing the pressure to a threshold; if the pressure is above the pressure threshold, controlling the blower to reduce the pressure below the threshold; and if the pressure is below the threshold, controlling the blower to achieve the target flow rate.

[0050] In some forms, the blower is controlled by controlling one or more of: a motor speed, a motor current, and / or a motor voltage to a target motor speed, a target motor current, and / or a target motor voltage.

[0051] In some forms, the target motor speed may be decelerated at a constant rate. In some forms, the target motor speed may be decelerated at a variable rate.

[0052] In some forms, the method may include continually decreasing the target motor speed until the pressure falls below a threshold value.

[0053] In some forms, the pressure sensor may be an absolute pressure sensor.

[0054] In some forms, the measurement may include taking a difference between a reading of the pressure sensor and a reading of a second pressure sensor, both of which are absolute pressure sensors.

[0055] In some forms, the pressure sensor may be a gauge pressure sensor configured to take the difference between ambient pressure and the pressure downstream of the flow generator.

[0056] In some configurations, the target flow rate may be constant.

[0057] In some forms, the method may include receiving an input of a target flow rate.

[0058] In some forms, the target flow rate may be set by the user.

[0059] In some forms, the control may include implementing a PID controller based on the difference between the target flow rate and the flow rate delivered to the patient as measured by one or more flow sensors to determine the desired motor speed.

[0060] In some forms, the device may include an oxygen inlet that is separate from the ambient inlet.

[0061] In some forms, the flow generator can be configured to mix ambient air from the ambient air inlet and oxygen from the oxygen inlet.

[0062] In some forms, FdO2 may depend in part on the target flow rate.

[0063] In some forms, the method may further include controlling the FdO2 by controlling the opening of an oxygen inlet valve.

[0064] In some forms, the method may further include detecting bubbling in a bubbler coupled to the respiratory device by monitoring a change in the flow parameter signal.

[0065] In some forms, the flow parameter signal may include a flow signal, a pressure signal, or a combination thereof.

[0066] In some forms, the change may be a change in amplitude of the flow parameter signal from a threshold value.

[0067] In some forms, the changes may be analyzed in the frequency domain.

[0068] In some forms, the method may further include outputting an alert in response to a lack of effervescence for a predetermined period of time.

[0069] In some forms, the method may further include outputting one or more of the following warnings based on whether foaming is detected: leak, blockage, intermittent foaming, suggested and / or automatic flow rate changes, and / or a flow rate that does not meet a required inspiratory volume.

[0070] In some forms, the device may further include a humidification chamber.

[0071] In some embodiments, the device includes a battery.

[0072] In some configurations, the battery is the primary power source for the device.

[0073] In some configurations, the battery is a secondary power source for the device.

[0074] In some embodiments, the device includes a motor speed limit.

[0075] In some embodiments, the motor speed limit is based on the ambient pressure or an ambient pressure.

[0076] In some forms, the device may be included in a respiratory system that includes a patient interface, where the system does not include a pressure relief valve between the flow generator and the patient interface.

[0077] In some forms, a respiratory device may be coupled to the inhalation conduit to provide a flow of gas to the patient interface.

[0078] In some forms, the patient interface may form a seal on or around the patient's face.

[0079] In some forms, the patient interface may be configured to connect to an exhalation conduit.

[0080] In some forms, the exhalation conduit may be configured to connect to a bubbler.

[0081] In some forms, a respiratory system configured to deliver bubble CPAP therapy to a patient via a patient interface may include a respiratory device including: a controller, a blower including a motor, where the blower motor speed may be controlled by the controller, the blower configured to generate a flow of gas to the patient at a target flow rate, and a housing enclosing the controller and the blower; an inhalation conduit for providing the gas flow to the patient interface; and an exhalation conduit having a proximal end and a distal end, where the proximal end is coupled to the patient interface and the distal end is submerged at a predetermined depth in the water column.

[0082] In some forms, the system may further include a pressure sensor configured to measure the pressure of the gas flow downstream of the blower, and the controller may be configured to: compare the pressure to a threshold; in response to the pressure exceeding the threshold, reduce a target motor speed of the blower; and in response to the pressure being equal to or less than the threshold, control the motor speed to achieve the target flow rate.

[0083] In some forms, a respiratory system configured to deliver bubble CPAP therapy to a patient via a patient interface may include a respiratory device including: a controller, a blower including a motor, where the motor speed of the blower may be controlled by the controller to a target motor speed, the blower configured to generate a flow of gas to the patient at a target flow rate, and a housing enclosing the controller and the blower; an inhalation conduit for providing the flow of gas to the patient interface; and an exhalation conduit having a proximal end and a distal end, where the proximal end is coupled to the patient interface and the distal end is submerged at a predetermined depth in the water column.

[0084] The blower includes an inlet that draws in ambient air and forces it towards the patient via the blower through a patient conduit (i.e., an inhalation conduit). A controller controls the blower to a target motor speed or a target flow or both. The controller preferably provides a control signal to control, i.e., vary, the current or voltage or power provided to the blower motor to achieve the target motor speed or target flow rate. The breathing system may also optionally include a supplemental gas inlet for receiving a supplemental gas, e.g., oxygen. The blower is configured to receive and mix the ambient gas and the supplemental gas.

[0085] In some forms, the system may further include a pressure sensor configured to measure a pressure of the gas flow downstream of the blower, and the controller may be configured to: compare the pressure to a threshold; in response to the pressure exceeding the threshold, reduce a target motor speed of the blower; and in response to the pressure being equal to or less than the threshold, adjust the target motor speed to achieve the target flow rate.

[0086] In some forms, the system may further include a pressure sensor configured to measure the pressure of the gas flow downstream of the blower, and the controller may be configured to: compare the pressure to a threshold; if the pressure is above the pressure threshold, control the blower to reduce the pressure below the threshold; and if the pressure is below the threshold, control the blower to achieve the target flow rate.

[0087] In some forms, the blower is controlled by controlling one or more of: a motor speed, a motor current, and / or a motor voltage to a target motor speed, a target motor current, and / or a target motor voltage.

[0088] In some forms, the target motor speed may be decelerated at a constant rate. In some forms, the target motor speed may be decelerated at a variable rate.

[0089] In some forms, the controller may be configured to continually reduce the target motor speed until the pressure falls below a threshold value.

[0090] In some forms, the pressure sensor may be an absolute pressure sensor.

[0091] In some forms, the pressure may be measured by taking the difference between a reading of a pressure sensor and a reading of a second pressure sensor, both of which are absolute pressure sensors.

[0092] In some forms, the pressure sensor may be a gauge pressure sensor configured to take the difference between ambient pressure and the pressure downstream of the blower.

[0093] In some configurations, the target flow rate may be constant.

[0094] In some forms, the controller can be configured to receive an input of a target flow rate.

[0095] In some forms, the target flow rate may be set by the user.

[0096] In some forms, the device may include an oxygen inlet that is separate from the ambient inlet.

[0097] In some forms, the blower can be configured to mix ambient air from the ambient air inlet with oxygen from the oxygen inlet.

[0098] In some forms, FdO2 may depend in part on the target flow rate.

[0099] In some forms, the controller may be further configured to control the FdO2 by controlling the opening of the oxygen inlet valve.

[0100] In some configurations, the system may include a bubbler, the bubbler containing the water column.

[0101] In some forms, the controller may be configured to detect foaming by monitoring changes in the flow parameter signal.

[0102] In some forms, the flow parameter signal may include a flow signal, a pressure signal, or a combination thereof.

[0103] In some forms, the change may be a change in amplitude of the flow parameter signal from a threshold value.

[0104] In some forms, the changes may be analyzed in the frequency domain.

[0105] In some forms, the controller may be configured to output a warning in response to a lack of foaming for a predetermined period of time.

[0106] In some forms, the controller may be configured to output one or more of the following warnings based on whether foaming is detected: leak, blockage, intermittent foaming, suggested and / or automatic flow rate changes, and / or a flow rate that does not meet the required inspiratory volume.

[0107] In some forms, the patient interface may form a seal on or around the patient's face.

[0108] In some forms, the device may further include a humidification chamber.

[0109] In some configurations, the device may further include one or more flow sensors.

[0110] In some forms, the system may not include a pressure relief valve between the blower and the patient interface.

[0111] In some forms, the device may be a high flow respiratory device.

[0112] In some embodiments, the device includes a battery.

[0113] In some configurations, the battery is the primary power source for the device.

[0114] In some configurations, the battery is a secondary power source for the device.

[0115] In some embodiments, the device includes a motor speed limit.

[0116] In some embodiments, the motor speed limit is based on the ambient pressure or an ambient pressure.

[0117] In some forms, a breathing system configured to provide high-flow therapy or bubble CPAP therapy, the breathing system includes: a breathing device including a flow generator, a humidifier in fluid communication with the flow generator, a controller for electronically controlling the flow generator, and an inhalation conduit in fluid communication with the humidifier, the breathing device being switchable between a high-flow therapy mode and a bubble CPAP therapy mode, wherein in the high-flow therapy mode, the breathing device is configured to provide high-flow therapy, and in the bubble CPAP therapy mode, the breathing device is configured to provide bubble CPAP therapy.

[0118] In some forms, the high flow therapy is nasal high flow therapy.

[0119] In some forms, the respiratory device includes a housing, the flow generator and the humidifier are integrated into the housing. A controller is also positioned within the housing. The humidifier may include a heater plate and a humidification chamber. The heater plate is positioned within the housing. The housing defines a chamber space, and the heater plate is within the chamber space. The humidification chamber is removably positioned on the heater plate. The housing includes a gas outlet, and the inhalation conduit is connectable to the outlet.

[0120] In the high flow therapy mode, the system includes a loose patient interface coupled to the inhalation conduit.

[0121] In the high flow therapy mode, the system includes a loose patient interface coupled to the inhalation conduit.

[0122] In some forms, the non-sealed patient interface may be a nasal cannula.

[0123] In some forms, during use, the nasal cannula is positioned on the user's face to provide gas to the user's nostrils.

[0124] In a bubble CPAP therapy mode, the system includes a tight-fitting patient interface coupled to an inhalation conduit, an exhalation conduit coupled to the tight-fitting patient interface, and the exhalation conduit coupled to a pressure regulator to regulate pressure within the patient interface and / or the patient's airway.

[0125] In some forms, the pressure regulator includes a chamber with a water column and the expiratory conduit is submerged in the water column, the pressure delivered to the user being defined or set by the depth to which the expiratory conduit is submerged in the water column.

[0126] In some configurations, the inhalation conduit is common to both the high flow and bubble CPAP therapy modes.

[0127] In some forms, the controller includes a high flow therapy control program associated with a high flow therapy mode.

[0128] In some forms, the controller includes a bubble CPAP therapy control program associated with a bubble CPAP therapy mode.

[0129] In some forms, the controller is configured to select and activate a program corresponding to a selected mode of operation.

[0130] In some embodiments, each program defines operating parameters.

[0131] In some forms, the operating parameters may include one or more of a motor speed or a pressure limit (eg, a pressure cap).

[0132] In some forms, the operating parameters may include one or more alarm conditions.

[0133] In some forms, the one or more alarm conditions may include a lack of bubbles in a bubble CPAP therapy mode.

[0134] In some forms, the operating parameters may define a humidity level.

[0135] In some forms, the operating parameters may be one or more temperature or dew point set points for controlling the humidifier.

[0136] In some forms, the humidity level provided during the high flow mode may be higher than the humidity level provided during the bubble CPAP therapy mode.

[0137] In some forms, the operating parameters may also define flow limits in each mode.

[0138] In some forms, the controller is configured to detect bubbling of the bubbler, and if bubbling is detected, the controller selects a bubble CPAP therapy mode.

[0139] In some forms, the controller automatically switches modes if the bubbler is detected by bubbling.

[0140] In some forms, the user may select (optionally via a user interface) a high-flow therapy mode or a bubble CPAP therapy mode.

[0141] In some forms, the controller is configured to detect foaming by monitoring a change in the flow parameter signal.

[0142] In some configurations, the flow parameter signal includes a flow signal, a pressure signal, or a combination thereof.

[0143] In some forms, the change is a change in amplitude of the flow parameter signal from a threshold value.

[0144] In some embodiments, the changes are analyzed in the frequency domain.

[0145] In some configurations, the same inhalation conduit may be used for the bubble CPAP mode and the high-flow mode. The same inhalation conduit that can be used for both modes reduces the number of components that need to be replaced when changing modes. Furthermore, this common inhalation conduit allows the same breathing equipment, with a blower and humidifier integrated into the housing, to be used for both the bubble CPAP mode and the high-flow mode. Furthermore, the integrated humidifier and blower in a common housing makes the transition between the bubble CPAP mode and the high-flow mode simpler because a single equipment can be used rather than a unique configuration of several components as required by prior art systems. The present system provides a single breathing equipment that can be used to perform both bubble CPAP therapy and high-flow therapy, while only the interface needs to be replaced. There is no replacement of gas supply side components, i.e., no replacement of gas supply components, since a common breathing equipment can be used to deliver humidified gas.

[0146] In some forms, a high-flow therapy mode kit for use with respiratory equipment includes one or more of: a non-contact patient interface, an inhalation conduit.

[0147] In some forms, the high flow therapy mode kit is used in a high flow therapy mode (as described elsewhere herein).

[0148] In some forms, a bubble CPAP therapy mode kit for use with a respiratory device includes one or more of: a close-fitting patient interface, an inhalation conduit, an exhalation conduit, and / or a bubbler.

[0149] In some forms, the bubble CPAP therapy mode kit is used in a bubble CPAP therapy mode (as described elsewhere herein).

[0150] These and other features, aspects, and advantages of the present disclosure will now be described with reference to the drawings of several embodiments, which are intended to illustrate, but not to limit, the present disclosure. [Brief description of the drawings]

[0151] [Figure 1] 1 illustrates diagrammatically a conventional arrangement for using a respiratory device to provide bubble CPAP. [Diagram 2] 1 shows a schematic representation of a respiratory apparatus with a flow generator for providing bubble CPAP. [Figure 3A] 1 illustrates a schematic of a high-flow respiratory system configured to provide respiratory therapy to a patient. [Figure 3B] FIG. 1 is a perspective front view of an exemplary high flow respiratory apparatus with a humidification chamber in place. [Figure 3C] FIG. 3C is a perspective rear view of the breathing apparatus of FIG. 3B. [Figure 4] 3C illustrates an exemplary sensing chamber of the respiratory device of FIG. 3B. [Diagram 5] FIG. 1 shows an exemplary block diagram for motor control in a respiratory apparatus with a flow generator providing bubble CPAP. [Figure 6] 1 shows an exemplary flow chart for detecting bubbles when providing bubble CPAP. [Figure 7] 1 shows a respiratory apparatus having a high flow therapy controller program and a bubble CPAP therapy controller program. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0152] Although several examples are described below, those skilled in the art will recognize that the disclosure extends beyond the specifically disclosed examples and / or uses, and obvious modifications and equivalents thereof, and therefore, the scope of the disclosure disclosed herein is not intended to be limited to any particular examples described below.

[0153] Bubble CPAP therapy can cause changes or oscillations in the pressure of gas delivered to a patient connected to a positive pressure ventilation device. By submerging one end of the expiratory conduit in the water column, the resulting bubbles cause changes or ripples in the pressure of the gas delivered to the patient. The bubble CPAP system also provides a way to change the average pressure of gas delivered to the patient by varying the level to which the end of the expiratory conduit is submerged in the water column. The level to which the end of the expiratory conduit is submerged in the water can be kept constant to maintain the average pressure of gas delivered to the patient.

[0154] As shown in FIG. 1, a conventional respiratory system for delivering bubble CPAP therapy may provide humidified and pressurized gas to a patient 119 through a patient interface, e.g., a mask 128, FIG. 1, connected to an inhalation conduit 121. The inhalation conduit 121 is connected to an outlet 112 of a humidification chamber 110 containing a volume of water 115. The volume of water 115 in the humidification chamber 110 is heated by a heating plate 113 located within the device housing 114, and water vapor begins to fill the volume of the chamber 110 above the water level. The water vapor may heat and humidify a flow of gas (e.g., air) provided to the chamber 110 from a wall source 118 (see FIG. 1) through an inlet 116 of the chamber 110. The heated and humidified gas is exhausted from the outlet 112 of the humidification chamber 110 to the inhalation conduit 121. 1, which may heat the walls of the conduit to promote a substantially constant humidity profile along the inhalation conduit 121 and therefore reduce condensation of humidified gas within the inhalation conduit 121. The device may provide power to heat the inhalation conduit 121 and heating plate 113, such as with input from one or more sensors in the system, as described in more detail below.

[0155] The humidified gas may pass through the inhalation conduit 121 to a patient interface, for example a mask 128 attached to and / or fitted around the mouth, nose, and / or nostrils of the patient 119. The inhalation conduit 121 provides the patient 119 with a flow of gas, which may be ambient air, oxygen, a mixture of the two, or a mixture of ambient air and one or more auxiliary gases. The gas may include a drug, which may be added by nebulization. The flow of gas through the inhalation conduit 121 may be delivered at a substantially constant flow rate in the bubble CPAP. As shown in FIG. 1, in the mechanism, the supply of the flow of gas is provided by a wall source 118. The wall source 118 may deliver the gas at a target flow rate to maintain the flow rate of gas delivered to the patient.

[0156] 1, excess gas may flow through an expiratory conduit 130 to a pressure regulator 134, which in the illustrated example is a bubbler. In a bubble CPAP system, the expiratory conduit 130 may terminate in an open end 136. This end 136 may be submerged in a volume of water 138 contained within the bubbler 134.

[0157] The bubbler may regulate the pressure by the end 136 of the expiratory conduit 130 being submerged to a desired depth below the level 140 of a volume of water 138. The end 136 may also be optionally located on a short conduit that may be incorporated into the end of the expiratory conduit 130. The bubbler may act as a pressure regulator to maintain the average or mean pressure at a target level by venting gas whenever the pressure exceeds a desired level. The bubble CPAP system may also include a pressure relief valve 146 to vent excess gas when the pressure exceeds a desired level. The bubbler may also provide oscillations in the pressure, which may be clinically beneficial. Bubble CPAP therapy may reduce the incidence of acute lung injury and bronchopulmonary dysplasia compared to intubation and / or mechanical ventilation.

[0158] Overview of an Exemplary Flow Therapy Device FIG. 2 shows an exemplary respiratory apparatus with a flow generator 218 (also referred to as a blower, but which may include other types of flow generators disclosed herein) configured to provide bubble CPAP. Using a flow generator to generate a flow of gas may allow the respiratory apparatus to be used to provide bubble CPAP without a wall source, such as in situations where a wall source is not available. Furthermore, using a flow generator, e.g., a blower, in the respiratory apparatus allows the respiratory apparatus to draw in ambient air and provide it as the flow of gas for bubble CPAP. This makes the respiratory apparatus simpler and less expensive to use, since there is no requirement to a gas reservoir or source of gas, e.g., a wall source. Furthermore, a respiratory apparatus with a flow generator, e.g., a blower, is advantageous because there is no risk of running out of gas, since ambient air is provided to the patient. This ensures that therapy is not interrupted due to a gas source running dry, since ambient air is plentiful. By incorporating a humidifier and, optionally, a supplemental gas blender into the flow generator (e.g., by incorporating the oxygen inlet port 358′ shown in FIG. 3C), fewer separate components are required for the system, thereby simplifying its mechanism. Furthermore, the system occupies less space, since there are fewer separate components connected by tubes. The described breathing apparatus with an integrated humidifier, and optionally an integrated supplemental gas blender, may occupy less space and reduce additional interconnecting tubes. Furthermore, the flow generator, integrated humidifier, and supplemental gas blender may be controlled by a single controller, thereby allowing additional monitoring and control of various flow parameters, as will be further described. Furthermore, a breathing apparatus including a flow generator may administer other forms of therapy, such as nasal high-flow therapy, thereby making it easier to transition between different types of respiratory support as the patient's condition changes, and may also reduce the number of consumable parts required, e.g., a common heated breathing tube may be used across multiple therapies, while only the patient interface needs to be replaced.

[0159] The breathing system of FIG. 2 may differ from the conventional bubble CPAP mechanism of FIG. 1 in that the gas flow is provided by a blower 218 integrated into at least the equipment housing 214. The system of FIG. 2 may also optionally include a supplemental gas source (e.g., an oxygen tank, an oxygen blender coupled to a flow meter, etc.) to control the oxygen concentration in the gas flow delivered to the patient 119. The supplemental gas source may be connected to the equipment housing 214 and / or the blower 218 (e.g., at the supplemental gas inlet). The supplemental gas source may also be configured to provide other types of supplemental gas, such as nitrogen. The supplemental gas source may be connected to an internal blender that blends the supplemental gas with ambient air to provide the gas flow to the patient. The concentration of the supplemental gas introduced into or present in the gas stream may be controlled. The system may include a temperature sensor in the inhalation conduit 121, such as the temperature sensor 144 of FIG. 1. The temperature sensor 144 may be coupled to and in electrical communication with a controller located in the equipment housing 214.

[0160] In some embodiments, the blower is configured to receive and mix the ambient gas and the supplemental gas.

[0161] The breathing system of Figure 2 may include a high flow system. A schematic diagram of a high flow system 10 is provided in Figure 3A. The breathing system 10 may include a main equipment housing 100. The main equipment housing 100 may include a flow generator 11, which may be in the form of a motor / impeller arrangement (such as a blower), an optional humidifier or humidification chamber 12, a controller 13, and a user interface 14. The user interface 14 may include a display and one or more input devices, such as one or more buttons, a touch screen, a combination of a touch screen and one or more buttons, etc. The controller 13 may include one or more hardware and / or software processors and be configured or programmed to control components of the respiratory apparatus, including but not limited to operating the flow generator 11 to generate a flow of gas for delivery to a patient, operating the humidifier 12 (if present) to humidify and / or heat the gas flow, receiving user input from a user interface 14 for reconfiguration and / or user-defined operation of the respiratory system 10, and outputting information to a user (e.g. on a display). The user may be a patient, a healthcare professional, etc.

[0162] 3A, the patient breathing conduit 16 is coupled to a gas flow outlet 21 of the main equipment housing 100 of the breathing system 10 and may be coupled to a patient interface 17. The patient interface may be a non-fitting interface, such as a nasal cannula with a manifold 19 and nasal prongs 18 to provide high-flow therapy. The nasal cannula does not completely fit over the user's nares, allowing exhaled gases to leak around the nasal prongs when the user exhales. The patient breathing conduit 16 may also be coupled to a fitting interface, such as a face mask, an oral-nose mask, a nasal mask, a nasal pillows mask, or a nasal cannula to provide bubble CPAP. The patient interface may also optionally include an endotracheal tube, a tracheotomy interface, or the like.

[0163] The gas flow may be generated by the flow generator 11 and humidified before being delivered to the patient through the patient interface 17 via the patient conduit 16. The controller 13 may control the flow generator 11 to generate a gas flow at a desired flow rate and / or one or more valves to control the mixture of air and oxygen or other breathable gas. The controller 13 may control a heating element (if present) in the humidification chamber 12 to heat the gas to a desired temperature and reach a desired level of temperature and / or humidity for delivery to the patient. The patient conduit 16 may have a heating element 16a, e.g., a heater wire, for heating the gas flow passing to the patient. The heating element 16a may also be under the control of the controller 13. The heating element 16a heats the gas to reduce and / or prevent condensation in the patient conduit 16.

[0164] The system 10 may use one or more ultrasonic transducers, one or more flow sensors, such as a thermistor flow sensor, one or more pressure sensors, one or more temperature sensors, one or more humidity sensors, or other sensors in communication with the controller 13 to monitor characteristics of the gas flow and / or operate the system 10 to provide a suitable therapy. The gas flow characteristics may include gas concentration, flow rate, pressure, temperature, humidity, etc. The sensors 3a, 3b, 3c, 20, 25, such as pressure, temperature, humidity, and / or flow sensors, may be located at various locations within the main equipment housing 100, the patient conduit 16, and / or the patient interface 17. The controller 13 may receive outputs from the sensors to assist the controller in determining a suitable target temperature, flow rate, and / or pressure gas flow to operate the respiratory system 10 to provide a suitable therapy. Providing a suitable therapy may include meeting a required inspiratory volume for the patient. Suitable therapy flow rates, for example high flow therapy flow rates and / or flow rates that meet or exceed the inhalation volume required by the patient, are described below.

[0165] The system 10 may include a wireless data transmitter and / or receiver, or transceiver 15, allowing 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 allow remote control of the system 10. In one example, the remote server may record patient usage data, such as usage of a bubble CPAP system or usage of a high flow system. Usage may include usage time and / or flow rate and humidity levels (e.g., dew point). The system 10 may also include wired connections, for example, using cables or communication lines, allowing the controller 13 to receive data signals 8 from the motion sensors and / or control various components of the system 10.

[0166] The system 10 may be powered from a mains voltage.

[0167] In some embodiments, the system may include an auxiliary power source (eg, a battery).

[0168] In some embodiments, the system may include a battery. The battery may provide the primary power source for the system or may act as a backup power source when the primary power source is unavailable. This is advantageous because it allows therapy to be continuous, i.e., gas may be continuously delivered to the patient even if mains power is lacking or unavailable. This is advantageous because therapy may be maintained for a period of time for neonates or infants, thereby reducing the chance of physiological deterioration or damage to these patients due to loss of therapy.

[0169] Batteries may increase the portability of the system, allowing it to be used in situations where mains voltage power is not available.

[0170] High-flow therapy as described herein shall be given its typical ordinary meaning as understood by those skilled in the art, thereby generally referring to a respiratory assistance system that delivers a targeted flow of humidified respiratory gas through an intentionally non-fitting patient interface, generally at a flow rate intended to meet or exceed the patient's inspiratory flow rate. Exemplary patient interfaces include, but are not limited to, nasal or tracheal patient interfaces. Typical flow rates for adults often range from, but are not limited to, about 15 liters per minute to about 60 liters per minute or more. Typical flow rates for pediatric patients (such as neonates, infants, and children) often range from, but are not limited to, about 1 liter per minute per kilogram of patient body weight to about 3 liters per minute or more per kilogram of patient body weight. High-flow therapy may also optionally include a gas mixture composition that includes supplemental oxygen, and / or administration of a therapeutic agent. High flow therapy is often called nasal high flow (NHF), humidified high flow nasal cannula (HHFNC), high flow nasal oxygen (HFNO), high flow therapy (HFT), or tracheal high flow (THF), among other common names.

[0171] As used herein, "high flow" therapy may refer to the administration of gases to a patient's airways at a relatively high flow rate, optionally meeting or exceeding the patient's required maximum inhalation volume. Some exemplary flow rates used to achieve "high flow" may be any of the flow rates listed below. For example, in some forms, for an adult patient, "high flow therapy" may refer to the delivery of one or more gases to a 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 embodiments, for neonatal, infant, or child patients, "high flow therapy" may refer to the delivery of one or more gases to a 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 15 LPM, or from about 20 LPM to 25 LPM. High flow therapy devices for adult, neonatal, infant, or child patients may deliver one or more gases to a patient at a flow rate of from about 1 LPM to about 100 LPM, or any of the subranges of flow rates outlined above.

[0172] 3B and 3C show an exemplary respiratory device of the respiratory system 10. The device may include a housing 300 that encloses a flow generator. The flow generator may include a motor and / or a sensor module. The motor and / or sensor module may be non-removable from the main housing 300. The motor and / or sensor module may also be optionally removable from the main housing 300. The housing 300 may include a humidifier or humidifier chamber space 318 for receiving a removable humidifier chamber 310. The removable humidifier chamber 310 contains a suitable liquid, e.g., water, to heat and humidify the gas delivered to the patient. The humidifier chamber 310 may be fluidly coupled to the device housing 300 with a linear sliding motion into the chamber space 318. A gas outlet port 322 may establish fluid communication between the motor and / or sensor module and the inlet 306 of the chamber 310.

[0173] The heated and humidified gases flow from the outlet 308 of the chamber 310 into the humidified gas return 340, which may include a removable elbow. The removable elbow may further include a patient outlet port 344 for coupling to an inhalation conduit, such as the inhalation conduit 16 of FIG. 3A, for delivery of gases to the patient interface 17. The gas outlet port 322, the humidified gas return 340, and the patient outlet port 344 may each have a seal, such as an O-ring seal or a T-seal, to provide a sealed gas passage between the device housing 300, the humidification chamber 310, and the inhalation conduit. The floor portion of the chamber space 318 within the housing 300 may include a heater arrangement, such as a heating plate or other suitable heating element or elements, to heat water in the humidification chamber 310 for use during the humidification process. The elbow may include one or more integrated sensors. For example, the elbow may include a pair of embedded temperature sensors.

[0174] As shown in FIG. 3C, the device may include an arrangement for allowing the flow generator to deliver air, oxygen (or alternative auxiliary gas), or a suitable mixture thereof, to the humidification chamber 310 and thereby to the patient. This arrangement may include an air inlet 356' in the rear wall 322 of the housing 300. The device may include a separate oxygen inlet port 358'. In the illustrated form, the oxygen inlet port 358' may be positioned adjacent one side of the housing 300 at its rear end. The oxygen port 358' may be connected to an oxygen source, such as a tank, or an oxygen blender. The oxygen inlet port 358' may be in fluid communication with a valve. The valve may preferably be a solenoid valve that can control the amount of oxygen added to the gas flow delivered to the humidification chamber 310.

[0175] The housing 300 may include a suitable electronic board, such as a sensing circuit board. The electronic board may include or be in electrical communication with suitable electrical or electronic components, such as, but not limited to, microprocessors, capacitors, resistors, diodes, operational amplifiers, comparators, and switches. One or more sensors may be used in conjunction with the electronic board. The components of the electronic board (such as, but not limited to, one or more microprocessors) may perform the function of the controller 13 of the respiratory apparatus. One or both of the electronic boards may be in electrical communication with the electrical components of the system 10, including, but not limited to, the display unit and user interface 14, motors, valves, and heating plates, to operate the motors to provide the desired flow rate of gas, humidify and heat the gas stream to the appropriate levels, and provide the appropriate amount of oxygen (or an alternative supplemental gas) to the gas stream.

[0176] As mentioned above, operational sensors, such as flow, temperature, humidity, and / or pressure sensors, may be located at various locations within the respiratory equipment, the patient conduit 16, and / or the cannula 17. The electronics board may be in electrical communication with the sensors. Output from the sensors may be received by the controller 13 to assist the controller 13 in operating the respiratory system 10 to deliver optimal therapy, including meeting the required inspiratory volume. One or more sensors (e.g., Hall effect sensors) may be used to measure the motor speed of the flow generator motor. The 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, the back-EMF may be measured from the non-energized windings of the motor, from which the motor position may be determined, which may then be used to calculate the motor speed. Additionally, a motor driver may be used to measure the motor current, which may be used together with the measured motor speed to calculate the motor torque. The motor may also include a low inertia motor.

[0177] Air from the room may enter the flow generator through an inlet port, e.g., air inlet port 356' in FIG. 3C. The flow generator may operate at a motor speed of more than 1,000 RPM and less than 30,000 RPM, more than 2,000 RPM and less than 21,000 RPM, more than 4,000 RPM and less than 15,000 RPM, or between any of the above values. Operation of the flow generator mixes the gases entering the flow generator, e.g., the motor and / or sensor chamber, through the inlet port. Using the flow generator as a mixer may reduce pressure drops that may otherwise occur in systems with separate mixers, e.g., static mixers including baffles, since mixing requires energy.

[0178] 4, the mixed air may flow out of the flow generator and into a flow path 402 in a sensor chamber 400, which may be located in a motor and / or sensor module. A sensing circuit board 404 with a sensor, such as an ultrasonic sensor 406 and / or a heated thermistor flow sensor, may be positioned in the sensor chamber 400 such that the sensing circuit board is at least partially immersed in the gas flow. At least a portion of the sensor on the sensing circuit board may be positioned in the gas flow to measure gas properties in the flow. After passing through the flow path 402 in the sensor chamber 400, the gas may flow out to a humidification chamber 310.

[0179] Positioning the sensor downstream of the flow generator may increase the accuracy of measurements, such as measurements of gas component concentrations, including oxygen concentration, over systems in which the sensor is positioned upstream of the flow generator and / or mixer. Such positioning may provide a repeatable flow profile. Additionally, positioning the sensor downstream of a combined flow generator and mixer avoids the effects of pressure drops that would otherwise occur when sensing is performed upstream of a flow generator and a separate mixer. Also, immersing at least a portion of the sensing circuit board and sensor in the flow path may increase measurement accuracy because the sensor, which is immersed in the flow, is subject to the same conditions, e.g., temperature and pressure, as the gas flow and therefore better represents the gas flow characteristics.

[0180] 4, the flow path 402 may have a curved shape. The flow path 402 may be configured to have a curved shape without sharp turns. The flow path 402 may have curved ends with straight sections between the curved ends. The curved flow path shape may reduce the pressure drop of the gas flow without reducing flow measurement sensitivity by partially coinciding the flow path with the measurement area to form the measurement portion of the flow path.

[0181] The sensing circuit board 404 may include sensors, such as acoustic transmitters and / or receivers, humidity sensors, temperature sensors, thermistors, etc. Gas flow rate may be measured using at least two different types of sensors. A first type of sensor may include a thermistor, which can determine the flow rate by monitoring heat transfer between the gas flow and the thermistor. A thermistor flow sensor may move a thermistor at a constant target temperature within the flow as the gas flows around and past the thermistor. The sensor may measure the amount of power required to maintain the thermistor at the target temperature. The target temperature may be configured to be higher than the temperature of the gas flow, such that more power is required to maintain the thermistor at the target temperature at higher flow rates.

[0182] The thermistor flow sensor may also maintain multiple (e.g., two, three or more) constant temperatures on the thermistor to avoid the difference between the target temperature and the gas flow temperature becoming too small or too large. Multiple different target temperatures may make the thermistor flow sensor accurate over a large temperature range of gas. For example, the thermistor circuit may be configured to be able to switch between two different target temperatures such that the temperature of the gas flow always falls within a certain range relative to one of the two target temperatures (e.g., not too close and not too far). The thermistor circuit may 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 may 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 may 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.

[0183] The controller may 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 may be arranged in a Wheatstone bridge configuration including a first voltage divider arm and a second voltage divider arm. The thermistor may be located in one of the voltage divider arms. More details of the thermistor flow sensor are described in International Publication No. WO2018052320A2, the entire contents of which are incorporated herein by reference.

[0184] A second type of sensor may include an acoustic (e.g., ultrasonic) sensor assembly. Acoustic sensors including acoustic transmitters and / or receivers may be used to measure the time of flight of an acoustic signal to determine the velocity and / or composition of a gas that may be used in a flow therapy device. In one ultrasonic sensing (including ultrasonic transmitters and / or receivers) topology, a driver causes a first sensor, e.g., an ultrasonic transducer, to generate an ultrasonic pulse in a first direction. A second sensor, e.g., 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. Using this measurement of the time of flight, the speed of sound of the gas flow between the ultrasonic transducers may be calculated by a processor or controller of the respiratory device. The second sensor may also transmit, and the first sensor may receive, the pulse in a second direction opposite the first direction to provide a second measurement of the time of flight, allowing a characteristic of the gas flow, e.g., flow rate or velocity, to be determined. In another acoustic sensing topology, acoustic pulses transmitted by an acoustic transmitter, e.g., an ultrasonic transducer, may be received by an acoustic receiver, such as a microphone. A more detailed acoustic flow sensor is described in International Publication No. WO2017095241A3, which is incorporated herein by reference in its entirety. Acoustic pulses may be transmitted along the flow path of the gas, thereby allowing the acoustic sensor to be used to measure the flow rate or velocity of the gas.

[0185] Readings from both the first and second types of sensors can be combined to determine a more accurate flow measurement. For example, a previously determined flow rate and one or more outputs from one of the types of sensors can be used to determine a predicted current flow rate. The predicted current flow rate can then be updated using one or more outputs from the other end of one of the first and second types of sensors to calculate a final flow rate.

[0186] The breathing system may be configured to provide high-flow or bubble CPAP therapy.

[0187] The respiratory device may be switchable between a high-flow therapy mode and a bubble CPAP therapy mode.

[0188] In the high flow therapy mode, the respiratory device is configured to provide high flow therapy.

[0189] In the bubble CPAP therapy mode, the respiratory device is configured to provide bubble CPAP therapy.

[0190] High flow therapy is nasal high flow therapy.

[0191] In the high flow therapy mode, the system includes a loose patient interface coupled to the inhalation conduit 121 .

[0192] The loose patient interface may be a nasal cannula.

[0193] In use, the nasal cannula is positioned on the user's face to deliver gas to the user's nostrils.

[0194] In the bubble CPAP therapy mode, the system includes a tight fitting patient interface coupled to an inhalation conduit 121 and an exhalation conduit 130 coupled to the tight fitting patient interface.

[0195] The expiratory conduit 130 is coupled to a pressure regulator to regulate the pressure within the patient interface and / or the patient's airway.

[0196] As explained in more detail above, the pressure regulator includes a chamber with a column of water, and the expiratory conduit 130 is submerged in the column of water. The pressure delivered to the user is defined or set by the depth to which the expiratory conduit 130 is submerged in the column of water.

[0197] The inhalation conduit 121 may be common to both the high flow and bubble CPAP therapy modes.

[0198] The same inhalation conduit that can be used in both modes reduces the number of components that need to be replaced when changing modes.

[0199] Additionally, this common inhalation conduit allows the same breathing equipment, including a blower and humidifier integrated into the housing, to be used for both bubble CPAP and high-flow modes. Additionally, the integrated humidifier and blower in a common housing makes the transition between bubble CPAP and high-flow modes simpler, as a single device can be used rather than a unique configuration of several components as required by prior art systems.

[0200] The system provides a single breathing apparatus that can be used to deliver both bubble CPAP and high-flow therapy, but requires modification of the interface only: there is no modification to the gas delivery components, i.e., there is no replacement of gas delivery components, as the common breathing apparatus can be used for the delivery of humidified gases.

[0201] As shown in FIG. 7, the controller 13 may include a high flow therapy control program 210 associated with a high flow therapy mode.

[0202] As shown in FIG. 7, the controller 13 may include a bubble CPAP therapy control program 211 associated with the bubble CPAP therapy mode.

[0203] In some embodiments, the high-flow therapy mode may use a high-flow therapy controller. Optionally, the high-flow therapy controller may be configured to execute the high-flow therapy control program 210.

[0204] In some embodiments, the bubble CPAP therapy mode may use a bubble CPAP therapy controller. Optionally, the bubble CPAP therapy controller may be configured to execute a bubble CPAP therapy control program 211.

[0205] The controller 13 is configured to select and apply the program 210, 211 corresponding to the selected operation mode.

[0206] Each of the high flow therapy control program 210 and the bubble CPAP therapy control program 211 defines corresponding operating parameters.

[0207] In some forms, the operating parameters may include one or more motor speeds or pressure limits (eg, upper pressure limits), as described in more detail below.

[0208] The operating parameters may include one or more alarm conditions.

[0209] The one or more alarm conditions may include a lack of bubbles in a bubble CPAP therapy mode.

[0210] In some embodiments, an alarm may be triggered when a lack of effervescence is detected for longer than a threshold period.

[0211] The operating parameters may define a humidity level.

[0212] The operating parameters may be one or more temperature or dew point set points for controlling the humidifier.

[0213] The humidity level provided during the high flow mode may be higher than the humidity level provided during the bubble CPAP therapy mode.

[0214] The operating parameters may also define flow limits corresponding to each mode.

[0215] The controller may be configured to detect bubbling of the bubbler, and if bubbling is detected, the controller selects a bubble CPAP therapy mode.

[0216] The controller may select the bubble CPAP therapy mode once bubbling is detected for a predetermined period of time.

[0217] The controller may, once bubbling is detected (optionally for a predetermined period of time), present a message to the user to consider changing the mode to a bubble CPAP therapy mode.

[0218] The controller may automatically switch the mode to bubble CPAP therapy mode if the bubbler is detected by bubbling.

[0219] A user may select (optionally via a user interface) a high flow therapy mode or a bubble CPAP therapy mode.

[0220] The detection of foaming may be as described elsewhere herein.

[0221] Control of FdO2 As mentioned above, the flow generator can be used as a mixer for oxygen and / or other breathable gases. A flow generator that draws in ambient air can mix the air with oxygen from an oxygen source, which can be from a high pressure or low pressure source.

[0222] When receiving oxygen from a low pressure source, which may include an oxygen canister or tank, a wall source of oxygen, or an oxygen concentrator, the breathing device may receive a constant flow of oxygen. This oxygen may then be mixed with ambient air. The percentage of oxygen in the gas delivered to the patient (FdO2) may depend on the set flow rate of oxygen from the low pressure source and the total flow rate generated by the device. The device may measure the FdO2 and display it on a display.

[0223] When receiving oxygen from a high pressure source, which may include an oxygen canister or tank, an oxygen wall source, or an oxygen concentrator, the device may control the flow rate of oxygen by controlling a valve to the oxygen inlet port as described herein. FdO2 may depend on the flow rate of oxygen through the valve, which may further depend on the valve opening state, and the total flow rate generated by the device. A user, such as a clinician, may set a target FdO2 on a user interface of a display, and the device then controls the opening of the valve based on the target FdO2 and the measured FdO2 to achieve the desired oxygen percentage. Oxygen concentration may be measured by various sensors, for example using the ultrasonic sensor described above. Exemplary methods for measuring oxygen concentration in more detail are described in International Publication No. WO2013151447A1, the contents of which are incorporated herein by reference in their entirety.

[0224] Flow Control As mentioned above, bubble CPAP generally involves delivering a constant flow of gas to the patient.

[0225] In some forms, parameters of the blower and / or motor may be controlled by the flow generator to maintain the flow rate at a desired level.

[0226] For example, the flow generator (or eg, a controller) may control one or more of the motor speed, motor current, and / or motor voltage to a target motor speed, target motor current, and / or target motor voltage.

[0227] In some forms, example respiratory devices disclosed herein may measure the flow rate of gas and control the motor speed of the flow generator based, at least in part, on the flow rate measurement to maintain a constant flow rate at a desired level.

[0228] The flow generator may, for example, control the motor speed of the motor to a target motor speed. The motor speed may correspond to a desired flow rate or target flow rate. In one example, the motor speed is a control parameter because feedback from the motor speed may be read more quickly by the controller compared to feedback from a sensor, e.g., a flow sensor downstream of the blower, such that the controller may be able to achieve a faster response. Alternatively, the controller may use flow readings from a flow sensor to control the motor.

[0229] The controller controls the blower to a target motor speed or a target flow or both. The controller preferably provides a control signal to control or vary the current or voltage or power supplied to the blower motor to achieve the target motor speed or target flow rate.

[0230] As a further alternative, the controller may control the motor using a combination of motor speed and flow rate. In this example, the controller may control the motor using feedback from the motor speed readings and flow readings from the flow sensor to achieve a target motor speed and / or target flow rate.

[0231] Measurement of flow rate may be performed by using one or more flow sensors. As mentioned above, examples of sensors capable of measuring the flow rate of gas may include ultrasonic sensors and heated thermistors. Ultrasonic sensors may provide a faster signal but are generally less accurate than heated thermistors. Heated thermistors may provide a more accurate signal but may not respond to small and rapid changes in flow. In the nasal high flow systems described herein, the flow signal of the flow sensor needs to be filtered before being used to control the flow generator. This is because a patient receiving nasal high flow may cause changes in flow by coughing, talking, changing the position of the cannula, etc. In this case, it may be desirable for the device not to make sudden changes in motor speed based on these events.

[0232] However, when implementing bubble CPAP, these patient-induced variations in flow are less common. Therefore, flow control can be designed to be more responsive, taking into account small leaks in the system, partial blockages, and / or dynamic changes in the patient's required breathing volume. Flow control can be performed by using shorter filters in the flow measurement than in nasal high-flow therapy. Additionally and / or alternatively, the controller can use a flow measured by an ultrasonic sensor to provide a much faster signal. Additionally and / or alternatively, the controller can use a combination of flow measured by an ultrasonic sensor and a heated thermistor. The controller can use an ultrasonic sensor to detect higher frequency changes in flow and a heated thermistor to compensate for less accurate measurements made by the ultrasonic sensor, which may be less accurate than when measured by a heated thermistor. The controller can also use one or more sensors of other types to measure flow and / or pressure. The pressure and / or flow sensor can include a single sensor.

[0233] Once the system controller receives a flow signal from one or more flow sensors disclosed herein, the controller may measure the flow rate from the flow signal. The system controller may determine the difference between the target flow rate and the measured flow rate. The difference may be input to a PID controller. The PID controller may output a command to vary the motor speed of the flow generator based on the input. In one example, the PID controller may output a current or voltage or power to the motor to control the motor speed.

[0234] Control of the flow rate may also be based on pressure measurements. In a conventional bubble CPAP system, a pressure relief valve may be placed between the flow source and the patient. The pressure relief valve is a passive valve that may open at a set pressure to release a portion of the gas flow, thereby limiting the pressure of the gas delivered to the patient.

[0235] By using a flow generator to provide the gas flow, the pressure limit can be implemented in the motor speed of the flow generator via software. The high flow system described herein may not include an additional valve to release the excess flow. Control of the motor speed may provide more precise control of pressure than releasing gas through a pressure relief valve, since the motor speed of the flow generator can be directly controlled based on the measured pressure. Use of a breathing system (i.e., breathing equipment) with a flow generator as described herein does not require a pressure relief valve, because the flow generator can be controlled to slow down the motor speed to generate less pressure if a pressure limit is reached. The system is simplified and requires fewer components, because the system does not require a pressure relief valve and does not require a gas source.

[0236] FIG. 5 shows an example block diagram of motor control by the appliance controller. The appliance controller may receive input 502 from one or more pressure sensors. The controller may measure the pressure delivered to the patient from the pressure sensor input. The pressure sensor may be located downstream of the flow generator. For example, the pressure sensor may be located at or near the patient interface. The pressure sensor may also be located immediately after the flow generator. The pressure delivered to the patient may be determined by taking the difference between the ambient pressure and the absolute pressure downstream of the flow generator. The pressure delivered to the patient may be estimated by measuring the pressure in the main appliance housing downstream of the flow generator and calculating the pressure drop along the inhalation conduit. One or more pressure sensors may also be located elsewhere in the gas flow. The pressure measurement may also be calculated, optionally, at least in part, based on the flow rate. The pressure sensor may include a gauge pressure sensor, or alternatively two absolute pressure sensors. The gauge pressure sensor may directly measure the difference between the absolute pressure downstream of the flow generator and the ambient pressure. In a system having two absolute pressure sensors, one sensor may be located downstream of the flow generator to measure the absolute pressure downstream of the flow generator, and the other sensor may be located at a different point to measure the ambient pressure, and the controller may determine the pressure delivered to the patient by determining the difference between the pressure measurements made by the two absolute pressure sensors.

[0237] In decision logic 504, the controller may compare the measured pressure (e.g., as described above) to a predetermined pressure limit. The pressure limit may be set to be above the maximum pressure to which the bubbler may be set. In some forms, the bubbler may be set to a maximum pressure of about 10 cmH2O, and the pressure limit for pressure control may be set to, for example, about 12 cmH2O, about 13 cmH2O, about 14 cmH2O, about 15 cmH2O, about 16 cmH2O, about 17 cmH2O, or about 18 cmH2O.

[0238] The pressure limit may be based on ambient pressure.

[0239] The relationship between the pressure limit and the ambient pressure may be linear or non-linear.

[0240] The pressure limit may be based on a fixed amount or percentage above ambient pressure.

[0241] A pressure limit that is based on ambient pressure allows for compensation for ambient pressure, which can be important in a bubble CPAP system when the maximum bubbler pressure is achieved by ambient pressure, so the effect of ambient pressure can be incorporated into the determination of the pressure limit.

[0242] In some embodiments, the pressure limit may be based on a predetermined ambient pressure (eg, a preset unmeasured ambient pressure).

[0243] The pressure limit may be set by the user.

[0244] If the measured pressure falls below the limit value, the controller may adjust the motor speed based on the output of a flow-based PID controller 506 described herein. The controller may input the difference between the target or set flow rate (as set by a user) and the measured flow rate to the PID controller. The controller may output as output 510 the motor speed determined by the PID controller configured to maintain the target flow rate.

[0245] If the measured pressure exceeds the pressure limit, the controller may execute a pressure upper limit algorithm 508. The pressure upper limit algorithm 508 may slow down the target motor speed according to a set amount, a set deceleration rate, a variable deceleration rate, or using a pressure-based PID control. The controller may output the reduced motor speed as the control output 510. The target motor speed is reduced with each iteration of the motor control as shown in FIG. 5 until the measured pressure falls below the pressure limit. The target motor speed may be reduced at a constant rate or a variable rate.

[0246] In some embodiments, the pressure upper limit algorithm 508 may reduce the target motor speed (eg, as part of a proportional control) in proportion to the amount the measured pressure exceeds the pressure limit.

[0247] In some embodiments, the pressure upper limit algorithm 508 may slow down the target motor speed to reduce the measured pressure below the pressure limit within a predetermined period of time. For example, the pressure upper limit algorithm 508 may slow down the target motor speed to reduce the measured pressure below the pressure limit within about 2 to about 20 seconds, or within about 5 to about 15 seconds, or within about 10 seconds.

[0248] In some embodiments, the set deceleration rate of the target motor speed may be set high enough to reduce the measured pressure below the pressure within a predetermined time.

[0249] Additionally and / or alternatively, the device may output a visual, audible, and / or tactile alarm when the measured pressure exceeds a threshold value.

[0250] In some forms, the device may prevent the motor from exceeding a set speed, further preventing too high pressures from being delivered to the patient. The motor speed limit may act as a fail-safe measure in the event that one or more sensors output false pressure readings and / or are otherwise defective. That is, two checks may be available to prevent the pressure of the gas flow from exceeding a predetermined maximum value. One check may be an upper pressure limit. The other check may be a maximum motor speed limit if the pressure sensor reading is erroneous.

[0251] In some embodiments, the motor speed limit may vary.

[0252] The motor speed limit may be based on ambient pressure, which allows, for example, the motor speed limit to take into account, for example, the altitude of the appliance.

[0253] The relationship between the motor speed limit and the ambient pressure may be linear or non-linear.

[0254] In some embodiments, the motor speed limit may be a first motor speed (eg, 10,000 RPM) when the ambient pressure is a first ambient pressure (eg, about 101 kPa (ie, about sea level)).

[0255] In some embodiments, the motor speed limit may be a second motor speed (e.g., about 15,000 RPM) when the ambient pressure is a second ambient pressure (e.g., about 79.5 kPa (i.e., about 2000 meters above sea level), or, for example, about 70.1 kPa (i.e., about 3000 meters above sea level).

[0256] The motor speed limit may vary between a first motor speed and a second motor speed between a first ambient pressure and a second ambient pressure.

[0257] In some embodiments, the motor speed limit may be further based on the ambient temperature.

[0258] Foam detection The flow generator of the high flow device may also be configured to detect the presence of bubbles in the bubbler. Bubbles may be useful in indicating that the system is working properly. For example, a momentary lack of bubbles may indicate that the patient's maximum inspiratory flow rate is exceeding the flow rate delivered by the device at that moment. Furthermore, a prolonged lack of bubbles may indicate a leak in the gas path, e.g., in the breathing circuit.

[0259] Bubbling may be detected by detecting the presence of oscillations in pressure and / or flow. In breathing systems where the flow rate is controlled by an appliance controller, the controller may determine the presence of bubbling using a pressure signal input, for example, from a pressure sensor as disclosed herein.

[0260] FIG. 6 shows an exemplary flow chart for determining whether bubbling can be detected. Although a pressure signal is used as an example in FIG. 6, the flow chart can also be applied to flow signals and / or combinations of pressure and flow signals. In step 602, the controller can receive a pressure signal from a pressure sensor. In step 603, the pressure signal is optionally filtered so that the measured amplitude is the amplitude of the measured pressure signal. In step 604, the controller can determine the amount of variation in the pressure signal from an average value of the pressure of the gas flow delivered to the patient (e.g., as measured by one or more pressure sensors disclosed herein). In steps 606 and 608, the controller can determine whether oscillations are present in the pressure signal. Oscillation is present if the amount of variation is above a certain magnitude 606 and above a certain frequency 608. For example, the pressure signal can be filtered using a high pass filter with a cutoff frequency of about 5 Hz, or a band pass filter with a cutoff frequency of about 5 Hz to about 20 Hz. The certain magnitude (e.g., when measured peak to peak) can be about 0.25 cmH2O. The threshold magnitude may be a single threshold or may vary depending on a set flow rate or pressure. If such oscillations are present, the controller may output an indication in step 610 that foaming is deemed to be occurring. In the example provided herein, if oscillations are present in the filtered signal with a magnitude (e.g., measured peak to peak) greater than about 0.25 cmH2O, the controller may determine that foaming is detected. If the magnitude is less than or equal to about 0.25 cmH2O, the controller may determine that foaming cannot be determined. Alternatively, the controller may analyze the power spectrum in the frequency domain. If there is sufficient power in that frequency band, the controller may determine that foaming is detected. Otherwise, the controller may determine that foaming is not detected. The controller may then return to step 602. If the change is less than or equal to the magnitude limit in step 606 and / or if the change is less than or equal to the frequency limit in step 608, the controller may return to step 602 to repeat the foaming detection process.The controller may optionally output a visual, audible, and / or tactile alarm of the absence of frothing in steps 612, 614.

[0261] The controller may also optionally monitor the duration for which no frothing is considered to be present. If frothing is not detected for a predetermined duration, for example, about 5 seconds, about 10 seconds, about 15 seconds, about 20 seconds, or longer, the controller may optionally output a message instructing the user to check for leaks in the gas path of the breathing system.

[0262] terminology Although the present disclosure has been described in terms of several embodiments and examples, it should be understood by those skilled in the art 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. Moreover, while several variations of the embodiments of the present disclosure have been shown and described in detail, other modifications 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 specific features and aspects of the embodiments may be made and still be within the scope of the present disclosure. For example, features described above in relation to one embodiment may 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 may be combined with or substituted for one another to form various aspects of the disclosed embodiments. Therefore, it is intended that the scope of the present disclosure herein should not be limited to the specific embodiments described above. Thus, unless otherwise specified or clearly incompatible, each embodiment of the present invention may 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.

[0263] It is understood that features, materials, properties, or groups described in conjunction with a particular aspect, embodiment, or example apply to any other aspect, embodiment, or example described in this section or elsewhere in this specification, unless incompatible. All features disclosed herein (including any attached claims, abstracts, 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. The scope of protection is not limited to the details of any of the above-mentioned embodiments. The scope of protection extends to any novel, or any novel combination of features disclosed herein (including any attached claims, abstracts, and drawings) or to any novel, or any novel combination of steps of any method or process so disclosed.

[0264] Moreover, certain features that are described in the present disclosure in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation may also be implemented in multiple implementations, separately or in any suitable subcombination. Furthermore, although features may be described above as taking on certain combinations, one or more features from a claimed combination may, in some cases, be deleted from the combination, and the combination may be claimed as a subcombination or a variation of the subcombination.

[0265] Additionally, although operations may be shown in the figures or described herein in a particular order, such operations need not be performed in the particular order or sequence shown, or all operations may be performed to achieve a desired result. Other operations not shown or described may be incorporated into 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 implementations. Those skilled in the art will recognize that in some embodiments, the actual steps performed in the described 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 others may be added. Additionally, the features and characteristics of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which are within the scope of the present disclosure. It should also be understood that the separation of various system components in the above-described implementations should not be understood to require such separation in all implementations, and that the described components and systems may generally be integrated together in a single product or packaged in multiple products.

[0266] For purposes of this disclosure, certain aspects, advantages, and novel features have been described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, one skilled in the art will recognize that the present disclosure may be embodied or practiced to achieve one advantage or group of advantages as taught herein, without necessarily achieving other advantages as may be taught or suggested herein.

[0267] Conditional language used herein, such as, among others, "can," "could," "might," "may," "for example," and the like, is intended to generally convey that some embodiments include certain features, elements, and / or steps, while other embodiments do not, unless specifically stated otherwise or understood otherwise within the context as used. Thus, such conditional language is not intended to imply in any way that features, elements, and / or steps are generally required in one or more embodiments, or that one or more embodiments necessarily include logic for determining whether those features, elements, and / or steps are included or performed in any particular embodiment, with or without other input or prompts. The terms "comprising," "including," "having," and the like are synonymous and are used inclusively, without restriction, and do not exclude additional elements, features, acts, operations, and the like. Also, the term "or" is used in its inclusive sense (and not its exclusive sense), and when used, for example, to connect a list of elements, the term "or" means one, some, or all of the elements in the list.

[0268] Conjunction language such as "at least one of X, Y, and Z," unless specifically stated otherwise, is generally understood in the context in which it is used to convey that an item, term, etc. may be either X, Y, or Z. Thus, such conjunctive language does not generally imply that some embodiments require the presence of at least one X, at least one Y, and at least one Z.

[0269] As used herein, language of degree, such as the terms "approximately," "about," "nearly, entirely," and "substantially," refers to a value, amount, or characteristic that is close to a stated value, amount, or characteristic and still performs a desired function or achieves a desired result. For example, the terms "approximately," "about," "nearly, entirely," 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 a stated amount. As another example, in some embodiments, the terms "nearly parallel, entirely parallel" and "substantially parallel" refer to a value, amount, or characteristic that deviates from exact parallelism by 15 degrees, 10 degrees, 5 degrees, 3 degrees, 1 degree, 0.1 degrees, or less, etc.

[0270] Any of the methods disclosed herein need not be performed in the order listed. The methods disclosed herein include some actions performed by a practitioner; however, they may also include any third-party command of those actions, either express or implied. For example, an action such as "control motor speed" includes "command control of motor speed."

[0271] All of the methods and tasks described herein may be performed by a computer system and may be fully automated. The computer system may in some cases include multiple separate computers or computing devices (e.g., physical servers, workstations, storage arrays, cloud computing resources, etc.) communicating and co-utilizing over a network to perform the described functions. Each such computing device generally includes a processor (or multiple processors) that executes program instructions or modules stored in memory or other non-transitory computer-readable storage media or devices (e.g., solid-state storage devices, disk drives, etc.). Various functions disclosed herein may be embodied in such program instructions and / or implemented in application-specific circuitry (e.g., ASICs or FPGAs) of the computer system. When a computer system includes multiple computing devices, these devices may, but are not necessarily, co-located. Results of the disclosed methods and tasks may be persistently stored by converting physical storage devices, such as solid-state memory chips and / or magnetic disks, to different states. In some embodiments, the computer system may be a cloud-based computer system in which processing resources are shared by multiple separate business entities or other users.

[0272] The scope of the present disclosure is not limited by the specific disclosure of preferred embodiments in this section or elsewhere herein, and may be defined by the claims, as presented in this section or elsewhere herein, or as presented in the future. Claim language is to be construed broadly based on the language used in the claims, and is not limited to the examples described herein or during prosecution, which examples are to be considered non-exclusive.

Claims

1. 1. A respiratory device configured to deliver respiratory therapy to a patient via a patient interface, the respiratory device comprising: controller; a blower including a motor, the blower motor speed being controlled by the controller; a pressure sensor configured to measure a pressure of the gas flow downstream of the blower. Including; The controller: comparing the pressure to a threshold; in response to the pressure exceeding the threshold, reducing a target motor speed of the blower; and In response to the pressure being equal to or less than the threshold, controlling the motor speed to achieve a target flow rate.

1. A respiratory apparatus comprising:

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