Respiratory support apparatus having high temperature mode

Abstract

To provide a respiratory support apparatus configured to provide a gas flow to a patient.SOLUTION: A respiratory support apparatus comprises: a flow generator configured to generate the gas flow; a humidifier configured to humidify the gas flow; and a controller. The apparatus is controlled by the controller to function in at least two modes, being a normal mode and a high-temperature mode. In the high-temperature mode, the temperature of gases delivered to the patient is higher than the temperature of gases delivered to the patient when in the normal mode. In the high-temperature mode, the controller controls one or more parameters of the gas flow to be different to that in the normal mode, whilst providing higher temperatures than in the normal mode. The apparatus is also operative in a cool-down mode in which one or more parameters of the gas flow are controlled. The apparatus includes safety features to ensure the temperature, dew-point, enthalpy, and / or energy of the gas flow do not exceed safe limits.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a respiratory assistance device having a high temperature mode and configured to provide a flow of gas for inspiration by a patient. [Background technology]

[0002] Respiratory support devices are used to deliver a flow of respiratory gas to patients in a variety of settings, such as hospitals or other medical facilities. The gas flow is typically heated and humidified to promote patient comfort and mitigate airway dryness. The gas flow is delivered to the patient via an inspiratory conduit and a patient interface. Examples of such respiratory support devices include non-invasive ventilation (NIV) devices, such as CPAP, PEEP, and Bi-Level devices, and high-flow devices.

[0003] The patient interface included in high-flow respiratory assistance devices typically includes a nasal cannula. The nasal cannula may include one or more prongs configured to be received in the patient's nostrils. The prongs may also be configured not to seal against the nostrils, allowing gases (including exhaled gases) to leak around the prongs. Therapy provided by a high-flow respiratory assistance device with a nasal cannula is often referred to as nasal high flow respiratory assistance or nasal high flow (NHF) therapy.

[0004] During NHF therapy, flow is typically maintained at a set rate within a range (e.g., 10-100 L / min for adults, 1-25 L / min for neonates or children). The gas flow may consist of air or air supplemented with additional oxygen. During NHF therapy, the temperature of the respiratory gas at the patient interface can typically be selected from a range of preset values ​​(e.g., 31°C, 34°C, or 37°C).

[0005] Another example of a respiratory support device is a non-invasive ventilation (NIV) device. A non-invasive ventilation device can be a flow-controlled device (which controls a set flow rate) or a pressure-controlled device (which controls a set pressure). A pressure-controlled NIV device can be controlled to a constant pressure (as in CPAP therapy) or a variable pressure (as in bilevel therapy). In bilevel NIV therapy, the set pressure during inspiration may be different from the set pressure during expiration.

[0006] Patient interfaces used in NIV devices typically include a patient interface that at least partially seals against the user's face. Examples of sealing patient interfaces include oral, nasal, or full-face masks that include a sealing cushion that seals against the patient's face. Summary of the Invention [Means for solving the problem]

[0007] The present disclosure stems from some research into providing a respiratory support device that can be used to improve patient care, and in some cases, to improve the care of patients infected with viruses such as human rhinovirus (HRV).

[0008] Devices according to the present disclosure can improve the treatment of patients with viral or bacterial infections of the upper respiratory tract, such as human rhinovirus (HRV) or influenza virus, or other viruses that cause upper respiratory tract infections.

[0009] One aspect of the present disclosure is to provide a respiratory assistance device that is controlled to deliver high flow rates of gas at relatively high temperatures, for example above 40°C, and optionally temperatures between 43-47°C.

[0010] One aspect of the present disclosure is to provide a respiratory aid device that is controlled to deliver a gas flow having high energy (compared to the energy of gas flows delivered by known respiratory aid devices). This high-energy gas flow can consist of a high-temperature gas flow or a high-dew point gas flow (i.e., a high-temperature and high-humidity gas flow). For example, the temperature of the gas flow can be greater than 40°C, and in some cases between 43 and 47°C. In this example, or another example, the dew point of the gas flow can be greater than 40°C, and in some cases between 43 and 47°C.

[0011] Another aspect of the present disclosure is to provide a high flow device that is controlled to manage the enthalpy and / or dew point of the gas flow to help prevent excessive enthalpy exposure and thermal injury to the patient during and immediately after exposure to high flow rates of hot gas. The enthalpy and / or dew point can be measured at the patient interface or calculated from measurements made elsewhere in the gas flow path between the flow generator and the patient interface.

[0012] An aspect of the present disclosure is to provide a device that operates according to a normal mode and according to a high temperature mode in which breathing gas is delivered to a patient at a relatively high temperature, the device further operating according to one or more safety algorithms. The safety algorithm can be configured to control one or more characteristics of the breathing gas to be within safe levels during the high temperature mode. The safety algorithm can be configured to control one or more characteristics of the breathing gas to be within safe levels after the high temperature mode has ended but before the normal mode resumes.

[0013] The present disclosure provides an apparatus that is controlled to deliver a gas flow at a relatively high temperature so as to increase the temperature of the gas delivered to the patient and / or to increase the dew point of the gas delivered to the patient. The dew point of the gas delivered to the patient varies depending on the humidity of the gas. The apparatus can be controlled to operate in a high temperature mode, in which the temperature of the gas delivered to the patient is relatively high, or in which both the temperature and dew point of the gas delivered to the patient are relatively high.

[0014] In devices according to the present disclosure, the temperature and / or dew point of the gas refers to the temperature and / or dew point of the gas as it is delivered to the patient (i.e., at the patient interface or at the patient). The temperature at the patient can be measured using one or more sensors at the patient. For example, these one or more sensors can be at the patient end of the inspiratory conduit or at or within the patient interface itself. Alternatively, the temperature can be measured elsewhere in the device. For example, the temperature can be measured at the humidifier, at the humidifier outlet, or at some other point between the humidifier and the patient. If the temperature is measured distal to the patient (e.g., at the humidifier outlet), the controller of the device can be configured to calculate how the temperature is likely to change between the point of measurement and the patient. The controller can be configured to control the heater of the heated inspiratory conduit to attempt to maintain the temperature of the gas before it reaches the patient. In other words, the controller can control the conduit heater to compensate for any calculated temperature drop along the inspiratory conduit.

[0015] The controller can control the conduit heater based on feedback from one or more patient-end sensors, such as temperature and / or humidity sensors, at the patient-end of the conduit. The patient-end sensor can be located at the patient-end of the conduit, for example, in a cuff or connector at the end of the conduit. The patient-end sensor can be located at the patient interface. The controller can be configured to determine a temperature drop from the end of the inspiratory conduit to the patient, for example, a drop of 3°C.

[0016] An apparatus according to the present disclosure can be controlled to deliver a gas stream having a high temperature and a high dew point (i.e., a gas stream having a high temperature and a sufficiently high relative humidity such that the gas stream has a high dew point).

[0017] In one example, a high dew point includes a temperature above 40° C. and a humidity above 80%.

[0018] A device according to the present disclosure can operate according to a high temperature mode in which the gas flow has a higher peak temperature and / or a higher dew point than in a normal mode, which is a therapeutic mode in which breathing gas is delivered to the patient, but not at a high temperature or a high dew point.

[0019] One aspect of the present disclosure is a safety algorithm configured to control the respiratory apparatus during and after a high temperature mode in which gas is delivered to a patient at a high temperature and a high dew point. In some aspects, the safety algorithm comprises: a) limiting the flow rate that can be used during high temperature mode; and / or b) limit the duration of the high temperature mode, and / or c) Controlling the process by which the device returns from the high temperature mode to the normal mode in which gas is delivered to the patient at a standard flow rate and lower temperature.

[0020] According to one aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify the gas stream; a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and when in the high temperature mode, the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient when in the normal mode; Equipped with In a normal mode, the controller controls the flow generator to generate a gas flow at a flow rate within a first flow rate range limited by a first peak flow rate; In the high temperature mode, the controller controls the flow generator to generate a gas flow at a flow rate within a second flow rate range limited by a second peak flow rate, the second peak flow rate being lower than the first peak flow rate in the normal mode.

[0021] According to one aspect of the present disclosure, there is provided a non-invasive ventilation respiratory assistance device configured to provide a flow of gas to a patient, the respiratory assistance device comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify the gas stream; a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and when in the high temperature mode, the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient when in the normal mode; Equipped with In a normal mode, the controller controls the flow generator to generate a gas flow at a flow rate within a first flow rate range limited by a first peak flow rate; In the high temperature mode, the controller controls the flow generator to generate a gas flow at a flow rate within a second flow rate range limited by a second peak flow rate, the second peak flow rate being lower than the first peak flow rate in the normal mode.

[0022] According to one aspect of the present disclosure, there is provided a high flow respiratory aid apparatus configured to provide a high flow of gas to a patient, the respiratory aid apparatus comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify the gas stream; a controller, wherein the device is controlled by the controller to function in at least two high flow modes, a normal mode and a high temperature mode, and when in the high temperature mode, the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient when in the normal mode; Equipped with In a normal mode, the controller controls the flow generator to generate a gas flow at a flow rate within a first flow rate range limited by a first peak flow rate; In the high temperature mode, the controller controls the flow generator to generate a gas flow at a flow rate within a second flow rate range limited by a second peak flow rate, the second peak flow rate being lower than the first peak flow rate in the normal mode.

[0023] The first flow rate range may be limited by a first minimum flow rate, and the second flow rate range is limited by a second minimum flow rate.

[0024] The magnitude of the change between the first flow rate range and the second flow rate range can be controlled to be less than a predetermined threshold.

[0025] The minimum flow rate of the second flow rate range may be less than or equal to the minimum flow rate of the first flow rate range when in normal mode.

[0026] The second flow rate range may be narrower than the first flow rate range.

[0027] The second flow rate range can be narrower than the first flow rate range by 1 to 70 L / min, preferably 5 to 60 L / min, and more preferably 10 to 60 L / min.

[0028] The first flow rate range may be 0 to 100 L / min, and the second flow rate range may be 20 to 80 L / min, more preferably 30 to 60 L / min.

[0029] The second flow rate can be 5 to 30 L / min, or 10 to 25 L / min, or substantially 15 L / min, or substantially 10 L / min less than the first flow rate.

[0030] When in high temperature mode, the gas flow to the patient may be at a temperature ranging from 41 to 50°C, preferably 43 to 47°C.

[0031] When in the high temperature mode, the controller can limit the duration of the high temperature mode to a maximum duration.

[0032] The device can be controlled by the controller in a further mode which is a cool down mode, which is activated after the high temperature mode, and when in the cool down mode: a) the flow rate is controlled to a flow rate setpoint, and the rate of change of the flow rate from the flow rate used during the high temperature mode to the flow rate setpoint is controlled to be less than a predetermined threshold; b) the power supplied to the humidifier heater is reduced from the power used during normal mode and / or high temperature mode; and / or c) The temperature setpoint of the gas stream delivered to the patient is reduced below the temperature setpoint during the high temperature mode. Any one or more of the following.

[0033] Power can be reduced by controlling, for example, PWM, duty cycle, voltage and / or current.

[0034] The power may be reduced by a predetermined amount and / or may be reduced to zero.

[0035] According to another aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify the gas stream; a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and when in the high temperature mode, the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient in the normal mode; Equipped with In the high temperature mode, the controller limits the duration of the high temperature mode to a maximum duration, which may be a set duration that controls the device to operate in the high temperature mode for a predetermined period of time, and the user can exit the high temperature mode at any time up to the maximum duration.

[0036] The flow generator can include one or more blowers, each including a motor and an impeller. The blowers can be mounted within the housing of the device. A humidifier can also be mounted within or on the housing of the device.

[0037] According to another aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a humidifier configured to humidify the gas stream; a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and when in the high temperature mode, the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient in the normal mode; Equipped with In the high temperature mode, the controller limits the duration of the high temperature mode to a maximum duration, which may be a set duration that controls the device to operate in the high temperature mode for a predetermined period of time, and the user can exit the high temperature mode at any time up to the maximum duration.

[0038] The device can include a gas inlet configured to receive one or more gases from an external gas source. The device can include multiple gas inlets. The external gas source can include, for example, an oxygen source. The external gas source can include a wall source, such as an oxygen wall supply in a hospital. The external gas source can include a tank or canister of compressed gas.

[0039] The controller can use the signal generated by the timer to limit the duration of the high temperature mode to a set duration.

[0040] The set duration may be 15 to 180 minutes, preferably 20 to 150 minutes, and more preferably 30 to 120 minutes.

[0041] The controller can use the signal generated by the counter to limit the duration of the high temperature mode to a set duration.

[0042] The device is capable of generating the signal.

[0043] The apparatus may comprise a further controller configured to generate the signal.

[0044] The apparatus is capable of receiving signals from a remote device.

[0045] The device can be controlled by the controller in a further mode which is a cool down mode, which is activated after the high temperature mode has ended and upon expiry of a set duration.

[0046] When in cool down mode, the flow rate can be controlled to a flow rate setpoint, and the rate of change of the flow rate from the flow rate used during the high temperature mode to the flow rate setpoint is controlled to be less than a predetermined threshold; The power supplied to the heater of the humidifier can be reduced below the power used during normal mode and / or high temperature mode; and / or The temperature setpoint of the gas flow delivered to the patient can be reduced below the temperature setpoint during the high temperature mode. Any one or more of the following.

[0047] The power supplied to the humidifier heater can be varied by changing any one or more of the PWM, duty cycle, voltage and / or current.

[0048] In cool down mode, the device can be controlled to a gas flow temperature setpoint of 40°C or less.

[0049] In the cool down mode, the device can be controlled to generate a gas flow at a rate within the range of the rate that occurs in the normal mode.

[0050] In the cool down mode, the apparatus may be controlled so that the enthalpy and / or dew point of the gas stream is reduced below that of the high temperature mode.

[0051] When in high temperature mode, the gas flow to the patient can be at a temperature range of 41-50°C, or 43-47°C, or 43-45°C.

[0052] According to a further aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify a gas flow, the humidifier comprising a humidifier heater; a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and when in the high temperature mode, the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient in the normal mode; Equipped with The apparatus is further controlled by the controller in a further mode which is a cool down mode, which is activated after the high temperature mode, and when in the cool down mode: a) the flow rate is controlled to a flow rate setpoint, and the rate of change of the flow rate from the flow rate used during the high temperature mode to the flow rate setpoint is controlled to be less than a predetermined threshold; b) the power supplied to the humidifier heater is reduced from the power used during normal mode and / or high temperature mode; and / or c) the temperature setpoint of the gas flow delivered to the patient is reduced below the temperature setpoint during the high temperature mode; Any one or more of the following.

[0053] According to a further aspect of the present disclosure, there is provided a high flow respiratory aid apparatus configured to provide a high flow of gas to a patient, the respiratory aid apparatus comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify a gas flow, the humidifier comprising a humidifier heater; a controller, wherein the device is controlled by the controller to function in at least two high flow modes, a normal mode and a high temperature mode, and when in the high temperature mode, the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient in the normal mode; Equipped with The apparatus is further controlled by the controller in a further mode which is a cool down mode, which is activated after the high temperature mode, and when in the cool down mode: a) the flow rate is controlled to a flow rate setpoint, and the rate of change of the flow rate from the flow rate used during the high temperature mode to the flow rate setpoint is controlled to be less than a predetermined threshold; b) the power supplied to the humidifier heater is reduced from the power used during normal mode and / or high temperature mode; and / or c) the temperature setpoint of the gas flow delivered to the patient is reduced below the temperature setpoint during the high temperature mode; Any one or more of the following.

[0054] The cool down mode may be automatically selected by the controller in response to one or more predetermined conditions of operation of the device.

[0055] The one or more predetermined conditions of operation are: a) a predetermined period determined by a timer; b) a predetermined number of counts determined by a counter; c) exceeding the dew point of the gas stream; d) exceeding the enthalpy of the gas flow; e) the user exits high temperature mode; Any one or more of the following may be selected.

[0056] The controller can return the device to normal mode after cool down mode.

[0057] The controller may return the device to normal mode after a predetermined period of time in cool down mode, which may range from 15 to 60 minutes, preferably 30 minutes.

[0058] The controller can return the device to normal mode depending on the temperature of the gas stream.

[0059] The controller may return the device to normal mode in response to the temperature of the gas stream being below a predetermined temperature.

[0060] The controller can return the device to normal mode depending on the dew point of the gas stream.

[0061] The controller can return the device to normal mode depending on the enthalpy of the gas flow.

[0062] When in the high temperature mode, the gas flow to the patient may be at a temperature range of 41-50°C, 43-47°C, preferably 43-45°C.

[0063] According to another aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify the gas stream; a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and when in the high temperature mode, the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient in the normal mode; Equipped with The controller controls the device to limit the properties of the gas flow during and / or immediately after the end of the high temperature mode so that the enthalpy and / or dew point of the gas flow is below a predetermined level. As noted above, the temperature, enthalpy and / or dew point of the gas flow may be measured at or near the patient interface, or may be measured elsewhere in the inspiratory gas flow path between the flow generator and the patient interface.

[0064] According to another aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a humidifier configured to humidify the gas stream; a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and when in the high temperature mode, the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient in the normal mode; Equipped with The controller controls the device to limit the properties of the gas flow during and / or immediately after the end of the high temperature mode so that the enthalpy and / or dew point of the gas flow is below a predetermined level. As noted above, the temperature, enthalpy and / or dew point of the gas flow may be measured at or near the patient interface, or may be measured elsewhere in the inspiratory gas flow path between the flow generator and the patient interface.

[0065] When in the high temperature mode, the gas flow to the patient may be at a temperature range of 41-50°C, 43-47°C, preferably 43-45°C.

[0066] According to a further aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify a gas flow, the humidifier comprising a humidifier heater; and a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and wherein when in the high temperature mode the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient in the normal mode, and when in the high temperature mode the gas flow to the patient is in a temperature range of 41-50°C or 43-47°C.

[0067] According to a further aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a humidifier configured to humidify a gas flow, the humidifier comprising a humidifier heater; and a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and wherein when in the high temperature mode the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient in the normal mode, and when in the high temperature mode the gas flow to the patient is in a temperature range of 41-50°C or 43-47°C.

[0068] According to a further aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify a gas flow, the humidifier comprising a humidifier heater; and a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and wherein when in the high temperature mode, the dew point of the gas delivered to the patient is higher than the dew point of the gas delivered to the patient in the normal mode, and when in the high temperature mode, the gas flow to the patient is in a dew point range of 43-47°C.

[0069] According to a further aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a humidifier configured to humidify a gas flow, the humidifier comprising a humidifier heater; and a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and wherein when in the high temperature mode, the dew point of the gas delivered to the patient is higher than the dew point of the gas delivered to the patient in the normal mode, and when in the high temperature mode, the gas flow to the patient is in a dew point range of 43-47°C.

[0070] This device is a) a patient interface configured to be attached to a patient and to receive a flow of humidified gas from a humidifier; b) a patient circuit comprising at least one patient conduit configured to connect to an outlet of the humidifier and to receive a humidified gas flow from the humidifier; c) headgear configured to attach the patient interface to the patient's head; The present invention may include any one or more of the following:

[0071] The patient interface may include a non-sealing interface. The patient interface may include a nasal cannula or a tracheal interface, such as a tracheal tube.

[0072] The patient interface may include a sealing interface.

[0073] The apparatus may comprise a user interface arranged to receive input from a user for controlling the apparatus. The user interface may be a graphical user interface, preferably a touchscreen graphical user interface. The normal mode and the high temperature mode may be user selectable via the user interface.

[0074] The user interface can be configured to present a countdown timer. The user interface can also display a button or interactive element that can restart the timer and the high temperature mode.

[0075] The device may be configured to limit the number of times a user can consecutively activate the high temperature mode.

[0076] The device can be controlled to provide a cool down mode after the high temperature mode has ended.

[0077] The cool down mode may be automatically selected by the controller in response to one or more predetermined conditions of operation of the device.

[0078] The one or more predetermined conditions of operation are: a) a predetermined period determined by a timer; b) a predetermined number of counts determined by a counter; c) exceeding the dew point of the gas stream; d) exceeding the enthalpy of the gas flow; e) the user exits high temperature mode; Any one or more of the following may be selected.

[0079] The device can be controlled to return to normal mode after cool down mode.

[0080] When in normal mode, the gas flow has the following characteristics: a) dew point in the range of 31°C to 37°C; b) a temperature in the range of 31°C to 37°C; c) Flow rates in the range of 10 L / min to 70 L / min; The control can be performed to have any one or more of the following:

[0081] When in high temperature mode, the gas flow has the following characteristics: a) dew point in the range of 40℃ to 47℃; b) a temperature in the range of 41°C to 50°C; c) Flow rate in the range of 30L / min to 40L / min; d) a minimum flow rate that is less than the minimum flow rate in normal mode by a predetermined amount; e) a minimum flow rate that is a predetermined amount greater than the minimum flow rate in normal mode; and f) a maximum flow rate that is less than the maximum flow rate in normal mode by a predetermined amount; The control can be performed to have any one or more of the following:

[0082] The flow range during the high temperature mode may be related to the flow range used during the normal mode, for example, the flow range during the high temperature mode may have a midpoint value of the same flow range.

[0083] According to one aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify the gas stream; a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and when in the high temperature mode, the temperature of the gas delivered to the patient is higher than the temperature of the gas delivered to the patient when in the normal mode; Equipped with In the normal mode, the controller controls the flow generator to generate a gas flow at a flow rate within a first flow rate range limited by a first peak flow rate; in the high temperature mode, the controller controls the flow generator to generate a gas flow at a flow rate within a second flow rate range limited by a second peak flow rate, the second peak flow rate being lower than the first peak flow rate of the normal mode; and in the high temperature mode, the controller limits the duration of the high temperature mode to a maximum duration; The apparatus is further controlled by the controller in a further mode which is a cool down mode, which is activated after the high temperature mode, and when in the cool down mode: a) the flow rate is controlled to a flow rate setpoint, and the rate of change of the flow rate from the flow rate used during the high temperature mode to the flow rate setpoint is controlled to be less than a predetermined threshold; b) the power supplied to the humidifier heater is reduced from the power used during normal mode and / or high temperature mode; and / or c) the temperature setpoint of the gas flow delivered to the patient is reduced below the temperature setpoint during the high temperature mode; Any one or more of the following.

[0084] A device according to the present disclosure may be a high-flow device configured to deliver a high flow rate of gas to a patient.

[0085] The high flow device may be configured for use with or may include a non-sealing patient interface. An example of a non-sealing patient interface includes a nasal cannula having one or more non-sealing nasal prongs. The non-sealing nasal prongs do not seal against the patient's nares.

[0086] A device according to the present disclosure may be a non-invasive ventilation device.

[0087] The non-invasive ventilation device may be configured for use with or may comprise a sealing patient interface, examples of which include a mouth, nose or full face mask that includes a sealing cushion that seals against the patient's face.

[0088] A device according to the present disclosure may be, for example, a pressure support device such as a CPAP or bilevel device.

[0089] According to one aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify the gas stream; a controller, wherein the device is controlled by the controller to function in a first and a second mode, and when in the first mode, gas is delivered to the patient at a higher dew point and / or a higher average temperature than when in the second mode; Equipped with.

[0090] According to one aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a humidifier configured to humidify the gas stream; a controller, wherein the device is controlled by the controller to function in a first and a second mode, and when in the first mode, gas is delivered to the patient at a higher dew point and / or a higher average temperature than when in the second mode; Equipped with.

[0091] According to one aspect of the present disclosure, there is provided a respiratory assistance apparatus configured to provide a flow of gas to a patient, the respiratory assistance apparatus comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify the gas stream; a controller, wherein the apparatus is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, wherein when in the high temperature mode the apparatus is operable at a first flow rate range and when in the normal mode the apparatus is operable at a second flow rate range, the second flow rate range being wider than the first flow rate range, and the apparatus is controlled in the high temperature mode for a predetermined duration; Equipped with.

[0092] The duration may be, for example, less than 120 minutes, less than 90 minutes, less than 60 minutes, less than 45 minutes, or less than 30 minutes.

[0093] The second flow rate range may be wider in terms of the peak flow rate in the second range and / or the width of the flow rate in the second range.

[0094] According to another aspect of the present disclosure, there is provided a method of providing respiratory assistance to a patient using an apparatus according to any one or more of the above descriptions.

[0095] The respiratory assistance device may comprise an inspiratory conduit configured to provide an inspiratory gas flow path for gas flow between the flow generator outlet and the patient interface.

[0096] The flow generator can include a blower. The flow generator can include a plurality of blowers. One of the plurality of blowers can be configured to generate a gas flow and another of the plurality of blowers can be configured to force exhaled gases along the exhalation conduit, for example, via generation of suction in the exhalation conduit.

[0097] The device may include a housing. The flow generator may be located within the housing. The humidifier may be located within the housing. Both the flow generator and the humidifier may be located within the same housing.

[0098] According to another aspect of the present disclosure, a respiratory assistance device according to any one of the preceding claims; a) a patient interface; b) an intake conduit; The breathing conduit may include a heater, such as a heater wire, configured to heat gas within the conduit.

[0099] It should be noted that the terms "patient" and "user" are used together herein. The term "patient" refers to a person receiving gas flow from a high-flow device. The term "user" refers to a person interacting with the controller of the device, which may include, for example, a graphical user interface (GUI). The user and patient may be the same person or different people.

[0100] Features from one or more embodiments or configurations may be combined with features from one or more other embodiments or configurations. Additionally, two or more embodiments may be used together during the process of assisting a patient's breathing.

[0101] The term "comprising" as used herein means "consisting at least in part of." When interpreting each description containing the term "comprising" herein, it is possible that features other than those preceding the term may be present. Related terms such as "comprise" and "comprises" should be interpreted similarly.

[0102] Reference to a range of numbers disclosed herein (e.g., 1 to 10) also incorporates reference to every rational number within that range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10) and any range of rational numbers within that range (e.g., 2 to 8, 1.5 to 5.5, and 3.1 to 4.7), and thus all subranges of every range explicitly disclosed herein are intended to be expressly disclosed by reference. These are merely examples of what is specifically intended, and all possible combinations of numerical values ​​between the lowest and highest values ​​recited should likewise be considered to be expressly stated in this application.

[0103] It is to be understood that alternative embodiments or configurations may include any or all combinations of two or more of the parts, elements or features shown, described or referred to herein.

[0104] The invention may also be broadly stated to consist in the parts, elements and features referred to or shown in the specification of this application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features.

[0105] Numerous modifications of the structure and widely different embodiments and applications of the present invention will occur to those skilled in the art to which the present invention pertains without departing from the scope of the present invention, as defined in the appended claims. The disclosures and descriptions herein are entirely illustrative and are not intended to be limiting in any sense. Where reference is made herein to specific wholes that have known equivalents in the art to which the present invention pertains, such known equivalents are deemed to be incorporated herein as if individually set forth. [Brief explanation of the drawings]

[0106] [Figure 1A] 1 illustrates, in schematic form, a respiratory assistance device; [Figure 1B] 1 shows a sensing circuit board including a flow sensor that can be used in a respiratory assistance device. [Figure 2] FIG. 10 is a flow diagram of control steps provided by a controller of a respiratory assistance device including a high temperature mode in accordance with the present disclosure. [Figure 3] FIG. 1 is a flow diagram of control steps provided by a controller of a respiratory assistance device including a cool down mode in accordance with the present disclosure. [Figure 4] 10 shows possible views of a graphic user interface that may form part of a respiratory assistance device according to the present disclosure; [Figure 5] 10 shows further possible views of a graphic user interface that may form part of a respiratory assistance device according to the present disclosure; [Figure 6] 1 is a graph illustrating how the enthalpy of gas provided to a patient by a respiratory assistance device can vary over time. [Figure 7] 1 illustrates, in schematic form, a respiratory assistance device in accordance with the present disclosure in communication with a remote management system; [Figure 8] 1 is an example electrical circuit incorporating a patient sensor of a device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0107] The present disclosure relates to a respiratory assistance device configured to safely deliver a gas flow at an elevated temperature to a patient. Introducing a humidified gas flow at an elevated temperature into the patient's nostrils may reduce symptoms associated with viruses, such as human rhinovirus (which can cause the common cold), influenza, and / or any other virus that may reside in or enter the body through the patient's upper respiratory tract. The reduction in symptoms may be due to increased thermal energy transferred to the patient's airways by the elevated temperature gas flow. According to aspects of the present disclosure, the gas flow may be a high flow rate gas, e.g., at a flow rate suitable for NHF.

[0108] Respiratory assistance devices according to the present disclosure can help overcome the problem of potential patient heat damage during or immediately after treatment, which can occur if the enthalpy (or dew point) of the gas flow is too high and / or if the high temperature treatment session lasts too long.

[0109] Further implementation details of devices according to the present disclosure are provided below.

[0110] In summary, however, one aspect of the present disclosure provides a high-flow respiratory assistance device that operates between a normal high-flow mode and a high-temperature high-flow mode. The high-temperature mode can be considered a high-energy mode in which the energy of the gas flow to the patient is increased compared to the gas flow delivered during normal therapy. The device includes a flow generator. The device is controlled according to the following high-level control steps:

[0111] a) Starting high temperature mode - The peak gas flow rate is reduced compared to the peak gas flow rate in normal mode. Alternatively or additionally, the flow rate range of the gas flow is reduced compared to the flow rate range of the gas flow in normal mode. The device can automatically vary the gas flow rate. b) High temperature mode operation A timer or counter generates a control signal that limits the maximum duration of the high temperature mode. c) After high temperature mode operation - 1st stage - The gas flow rate is gradually increased (or decreased) towards its set value after high temperature mode. The device can automatically increase (or decrease) the gas flow rate. - Reducing the power supplied to a gas heater, e.g., a humidifier heater. For example, the pulse width modulation (PWM) of the humidifier heater plate can be zeroed for a set period of time. - Limiting the temperature of the gas stream downstream of the device's humidifier for a set time. The controller can limit the maximum temperature set point for a given time. d) After high temperature mode operation - subsequent stages -Increase the power that can be supplied to the gas heater. The power supplied to the heater can be changed in a number of ways. For example, the PWM of the humidifier heater (which can be a heater plate) can be increased back to the PWM used when the device is in normal mode. The power supplied to the gas heater can also (or alternatively) be changed by changing the duty cycle of the gas heater or by changing the voltage and / or current supplied to the gas heater. - Gradually increase the temperature of the gas stream (measured at a given point in the flow path) towards its post-hot mode setpoint (for that given point in the flow path). The temperature of the gas stream can be measured anywhere downstream of the humidifier (e.g., at the patient interface). In some instances, it is convenient to measure the temperature of the gas stream at the end of the hose that delivers the gas stream from the humidifier to the patient interface (this measurement is known as the end-of-hose, or EoH, temperature).

[0112] One aspect of the present disclosure provides a respiratory assistance device, such as an NIV device, that operates between a normal mode and a hyperthermic mode. The device includes a flow generator. The device is controlled according to the following high-level control steps:

[0113] a) Starting high temperature mode - The peak gas flow rate is reduced compared to the peak gas flow rate in normal mode. Alternatively or additionally, the flow rate range of the gas flow is reduced compared to the flow rate range of the gas flow in normal mode. The device can automatically vary the gas flow rate. Alternatively, the maximum and / or minimum pressure is changed. Alternatively, the device 10 may control the flow generator to provide a constant pressure during the high temperature mode. b) High temperature mode operation A timer or counter generates a control signal that limits the maximum duration of the high temperature mode. c) After high temperature mode operation - 1st stage - Gradually increase (or decrease) the gas flow rate towards its set value after high temperature mode. The device can automatically increase the gas flow rate. - Reducing the power supplied to a gas heater, e.g. a humidifier heater. For example, the PWM of the humidifier heater plate can be set to zero for a set period of time. - Limiting the temperature of the gas stream downstream of the device's humidifier for a set time. The controller can limit the maximum temperature set point for a given time. d) After high temperature mode operation - subsequent stages -Increase the power that can be supplied to the gas heater. The power supplied to the heater can be changed in a number of ways. For example, the PWM of the humidifier heater (which can be a heater plate) can be increased back to the normal PWM used when the device is in normal mode. The power supplied to the gas heater can also (or alternatively) be changed by changing the duty cycle of the gas heater or by changing the voltage and / or current supplied to the gas heater. - Gradually increase the temperature of the gas stream (measured at a given point in the flow path) towards its post-hot mode setpoint (for that given point in the flow path). The temperature of the gas stream can be measured anywhere downstream of the humidifier (e.g., at the patient interface). In some instances, it is convenient to measure the temperature of the gas stream at the end of the hose that delivers the gas stream from the humidifier to the patient interface (this measurement is known as the end-of-hose, or EoH, temperature).

[0114] One aspect of the present disclosure provides a respiratory assistance device that operates between a normal mode and a high temperature mode, the device being controlled according to the following high level control steps:

[0115] High temperature mode activation - The peak gas flow rate is reduced compared to the peak gas flow rate in normal mode. Alternatively or additionally, the flow rate range of the gas flow is reduced compared to the flow rate range of the gas flow in normal mode. If the device does not include a flow generator, or if a flow generator is not used, the device can receive gas flow from one or more gas sources to which the device is connected. In such embodiments, the device can receive a reduced gas flow that is manually adjusted by a user, for example, by opening or closing a flow control valve of the gas source. In such embodiments, the device can be configured to generate one or more reminders when the high temperature mode is activated to prompt a user to reduce the gas flow rate from the gas source. High temperature mode operation A timer or counter generates a control signal that limits the maximum duration of the high temperature mode. After high temperature mode operation - 1st stage - The gas flow rate is gradually increased (or decreased) towards the set value after high temperature mode. The device can automatically increase the gas flow rate. - Reducing the power supplied to a gas heater, e.g. a humidifier heater. For example, the PWM of the humidifier heater plate can be set to zero for a set period of time. - Limiting the temperature of the gas stream downstream of the device's humidifier for a set time. The controller can limit the maximum temperature set point for a given time. After high temperature mode operation - subsequent stages -Increase the power that can be supplied to the gas heater. The power supplied to the heater can be changed in a number of ways. For example, the PWM of the humidifier heater (which can be a heater plate) can be increased back to the normal PWM used when the device is in normal mode. The power supplied to the gas heater can also (or alternatively) be changed by changing the duty cycle of the gas heater or by changing the voltage and / or current supplied to the gas heater. - Gradually increase the temperature of the gas stream (measured at a given point in the flow path) towards its post-hot mode setpoint (for that given point in the flow path). The temperature of the gas stream can be measured anywhere downstream of the humidifier (e.g., at the patient interface). In some instances, it is convenient to measure the temperature of the gas stream at the end of the hose that delivers the gas stream from the humidifier to the patient interface (this measurement is known as the end-of-hose, or EoH, temperature).

[0116] breathing assistance device It is known to provide respiratory aid devices. One example of such a respiratory aid is a high-flow respiratory aid device that includes a patient interface in the form of a nasal cannula. The nasal cannula has prongs that are received within the patient's nostrils. In such devices, the patient typically exhales directly into the atmosphere through their mouth and / or through a leak around the cannula's prongs. In such examples, such a respiratory aid device can be controlled to a user-defined flow rate, for example, to generate an inspiratory gas flow at a rate of approximately 50-60 L / min. In an alternative embodiment, the high-flow respiratory aid device may include a tracheal patient interface for delivering the high flow rate, for example, through a tracheal tube inserted in the patient's neck.

[0117] Another example of a respiratory support device is an NIV device that includes a patient interface in the form of a sealing interface, such as a full-face mask, that seals around the patient's nose and mouth. In such an example, the respiratory support device can be controlled to a user-defined pressure. This pressure can generate an inspiratory gas flow at a flow rate of, for example, about 1 to 40 L / min. The present disclosure provides an NIV device that operates according to a normal mode, a high-temperature mode, and a cool-down mode, in which a high-temperature inspiratory gas flow is provided to the patient. The inspiratory gas flow during each mode can be controlled by controlling the pressure of the flow.

[0118] FIG. 1A illustrates a high-flow respiratory aid device 10. The respiratory aid device 10 may include a main housing 100 containing a flow generator 11 in the form of a motor / impeller arrangement (e.g., a blower), an optional humidifier 12, a controller 13, and a user interface 14 (including, e.g., a display and input devices such as buttons, a touch panel, etc.). The controller 13 may be configured or programmed to control the operation of the device. For example, the controller may control device components, such as, but not limited to, operating the flow generator 11 to generate a flow of gas (gas flow) for delivery to a patient, operating the humidifier 12 (if present) to humidify and / or heat the generated gas flow, controlling the flow of oxygen to the flow generator blower, receiving user input from the user interface 14 for reconfiguration and / or user-defined operation of the device 10, and outputting information to a user (e.g., on a display). The user may be a patient, a medical professional, or any other person interested in using the device. As used herein, "gas flow" can refer to any flow of gas that can be used in a breathing assistance or respiratory device, such as a flow of ambient air, a flow containing substantially 100% oxygen, or a flow containing some combination of ambient air and oxygen.

[0119] A patient breathing conduit 16 is coupled at one end to a gas outlet 21 within the housing 100 of the respiratory assistance device 10. The patient breathing conduit 16 is coupled at another end to a patient interface 17, such as a non-sealing nasal cannula having a manifold 19 and nasal prongs 18. Additionally or alternatively, the patient breathing conduit 16 may be coupled to a face mask, nasal mask, nasal pillow mask, endotracheal tube, tracheostomy interface, or the like. Preferably, in the respiratory assistance device 10, the patient interface 17 is a non-sealing interface to provide high-flow respiratory assistance to the patient. The gas flow generated by the respiratory assistance device 10 may be humidified and delivered to the patient via the patient conduit 16 through the cannula 17. The patient conduit 16 may include a heater wire 16a for heating the gas flow passing to the patient. The heater wire 16a may be under the control of the controller 13. The patient conduit 16 and / or the patient interface 17 may be considered part of the respiratory assistance apparatus 10 or peripheral to the respiratory assistance apparatus 10. Together, the respiratory assistance apparatus 10, the respiratory conduit 16 and the patient interface 17 may form a respiratory assistance system.

[0120] The apparatus 10 comprises: a. A housing having a humidifier and a flow generator disposed therein. b. An elbow that fluidly couples the humidifier outlet to the device outlet. The elbow is removable so that it can be disinfected or replaced to reduce the chance of infection to the patient.

[0121] The controller 13 can control the flow generator 11 to generate a gas flow at a desired rate. The controller 13 can also control a supplemental oxygen inlet to allow for the delivery of supplemental oxygen, a humidifier 12 (if present) to humidify the gas flow and / or heat the gas flow to an appropriate level, etc. The gas flow is directed to the patient through a patient conduit 16 and a cannula 17. The controller 13 can also control a heating element in the humidifier 12 and / or a heating element 16a in the patient conduit 16 to heat the gas to a desired temperature for a desired level of therapy and / or comfort for the patient. The controller 13 can be programmed with a suitable target temperature for the gas flow, or the controller 13 can determine such a temperature. This temperature can include the temperature of the gas flow or the dew point of the gas flow.

[0122] The oxygen inlet port 28 can include a valve that allows pressurized gas to enter the flow generator or blower. The valve can control the flow of oxygen to the flow generator blower. The valve can be any type of valve, including a proportional valve or a binary valve. The oxygen source can be an oxygen tank or a hospital oxygen supply. Medical-grade oxygen is typically 95% to 100% pure. Less pure oxygen sources can also be used. Examples of valve modules and filters are disclosed in U.S. Provisional Patent Application No. 62 / 409,543, entitled "Valve Module and Filter," filed October 18, 2016, and U.S. Provisional Patent Application No. 62 / 488,841, entitled "Valve Module and Filter," filed April 23, 2017, both of which are incorporated herein by reference in their entireties. Valve modules and filters are discussed in more detail below in connection with FIG. 6.

[0123] Respiratory assistance device 10, in some examples, can measure and control the oxygen content of the gas being delivered to the patient and, therefore, the oxygen content of the gas inhaled by the patient. During high-flow respiratory assistance or therapy (i.e., high-flow therapy), the high flow rate of gas delivered meets or exceeds the patient's peak inspiratory demand. This means that the volume of gas delivered by the device to the patient during inspiration meets or exceeds the volume of gas inhaled by the patient during inspiration. Thus, high-flow respiratory assistance (i.e., high-flow therapy) helps prevent the entrainment of ambient air as the patient inhales and flushes exhaled gases from the patient's airway. As long as the flow rate of delivered gas meets or exceeds the patient's peak inspiratory demand, entrainment of ambient air is prevented and the composition of the gas delivered by the device is substantially the same as the composition of the gas inhaled by the patient. Therefore, the oxygen fraction measured by the device, known as the fraction of delivered oxygen (FdO2), is substantially the same as the oxygen fraction of the gas inhaled by the user, known as the fraction of inspired oxygen (FiO2). Thus, the terms FdO2 and FiO2 can be viewed as equivalent in this context. Note that in other examples, the device 10 may not include any oxygen control and may provide high flow to the patient without any supplemental oxygen being provided, i.e., the inspiratory gas flow to the patient is a flow generated from ambient air through a flow generator inlet, which may optionally be humidified.

[0124] Operational sensors 3a, 3b, 3c, such as flow, temperature, humidity, and / or pressure sensors, may be located at various locations within the respiratory aid apparatus 10. Additional sensors (e.g., sensors 20, 25) may be located at various locations on the patient conduit 16 and / or cannula 17 (e.g., there may be a temperature sensor 29 at or near the end of the inspiratory tube or at the patient interface). Outputs from the sensors are received by the controller 13 and may help the controller operate the respiratory aid apparatus 10 to provide a suitable therapy. In some configurations, providing a suitable therapy includes meeting the patient's peak inspiratory demands. The apparatus 10 may include a transmitter and / or receiver 15 that enables the controller 13 to receive signals 8 from the sensors and / or control various components of the respiratory aid apparatus 10, including, but not limited to, the flow generator 11, the humidifier 12, and the heater wire 16a, or accessories or peripheral devices associated with the respiratory aid apparatus 10. Additionally or alternatively, the transmitter and / or receiver 15 may send data to a remote server or allow remote control of the device 10 .

[0125] Oxygen can be measured by placing one or more gas composition sensors (such as an ultrasound transducer system, also referred to as an ultrasound sensor system) downstream from the point in the flow path where the oxygen and ambient air finish mixing. Measurements can be made in the device, the delivery conduit, the patient interface, or any other suitable location. The particular sensor or sensors used can vary depending on the control requirements. In one example, an ultrasound transducer system is positioned in the gas flow path within the housing of the respiratory assistance device.

[0126] The respiratory assistance device 10 may, in some examples, include a patient sensor 26, such as a pulse oximeter or patient monitoring system, that measures one or more physiological parameters of the patient, such as the patient's blood oxygen saturation (SpO2), heart rate, respiratory rate, or perfusion index. The patient sensor 26 may also provide a signal quality measurement. The sensor 26 may communicate with the controller 13 via a wired connection or by communication via a wireless transmitter on the sensor 26. The sensor 26 may be a disposable, adhesive sensor designed to be connected to the patient's finger. The sensor 26 may also be a non-disposable sensor. Sensors designed for different age groups and to be connected to different locations on the patient are available and can be used with the respiratory assistance device.

[0127] If patient sensor 26 is a pulse oximeter, it is attached to the patient, typically on the patient's finger, although other locations such as the earlobe are also options. The pulse oximeter is connected to a processor within device 10, for example, controller 13, and constantly provides a signal indicative of the patient's blood oxygen saturation.

[0128] The patient sensors 26 may be hot-swappable devices that can be installed or replaced while the respiratory assistance apparatus 10 is in operation. For example, the patient sensors 26 may be connected to the respiratory assistance apparatus 10 using a USB interface or using a wireless communication protocol (e.g., near field communication, WiFi, Bluetooth, etc.). If the patient sensors 26 are disconnected during operation, the respiratory assistance apparatus 10 may continue to operate in its previous operating state for a defined period of time. The patient sensors 26 may also be bedside monitoring systems or other patient monitoring systems that communicate with the respiratory assistance apparatus 10 via a physical or wireless interface.

[0129] High-flow respiratory assistance, as discussed herein, is intended to be given its typical and ordinary meaning as understood by those skilled in the art, and refers to a respiratory assistance system that delivers a target flow rate of humidified respiratory gas through an intentionally non-sealing patient interface, generally at a flow rate intended to meet or exceed the patient's inspiratory flow rate. Typical patient interfaces include, but are not limited to, nasal or tracheal patient interfaces. Typical flow rates for adults often range, but are not limited to, from about 15 liters per minute (L / min) to about 70 liters / min or more. Typical flow rates for pediatric patients (such as neonates, infants, and children) often range, but are not limited to, from about 1 liter / min per kilogram of patient weight to about 3 liters / min per kilogram of patient weight or more. High-flow respiratory assistance (i.e., high-flow therapy) can also optionally include the administration of a gas mixture composition containing supplemental oxygen and / or a therapeutic agent. High-flow respiratory support is often referred to as 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. The flow rate used to achieve "high flow" (i.e., high-flow respiratory support) can be any of the flow rates listed below. For example, in some configurations, for an adult patient, "high flow respiratory support" may refer to the delivery of gas to a patient at a flow rate of about 10 liters per minute (10 L / min) or greater, such as from about 10 L / min to about 100 L / min, or from about 15 L / min to about 95 L / min, or from about 20 L / min to about 90 L / min, or from about 25 L / min to about 75 L / min, or from about 25 L / min to about 85 L / min, or from about 30 L / min to about 80 L / min, or from about 35 L / min to about 75 L / min, or from about 40 L / min to about 70 L / min, or from about 45 L / min to about 65 L / min, or from about 50 L / min to about 60 L / min.In some configurations, for neonatal, infant, or pediatric patients, "high flow respiratory support" (i.e., high flow therapy) may refer to the delivery of gas to a patient at a flow rate greater than 1 L / min, such as from about 1 L / min to about 25 L / min, from about 2 L / min to about 25 L / min, or from about 2 L / min to about 5 L / min, or from about 5 L / min to about 25 L / min, or from about 5 L / min to about 10 L / min, or from about 10 L / min to about 25 L / min, or from about 10 L / min to about 20 L / min, or from about 10 L / min to about 15 L / min, or from about 20 L / min to about 25 L / min. High flow respiratory support devices for adult, neonatal, infant, or pediatric patients can deliver gas to a patient at a flow rate of from about 1 L / min to about 100 L / min, or any of the subranges outlined above. Respiratory assistance device 10 can deliver any concentration of oxygen (e.g., FdO2) up to 100% at any flow rate from about 1 L / min to about 100 L / min. In some configurations, any of the flow rates can be combined with oxygen concentrations (FdO2) of about 20%-30%, 21%-30%, 21%-40%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 70%-80%, 80%-90%, and 90%-100%. In some combinations, the flow rate may be between about 25 L / min and 75 L / min in combination with oxygen concentrations (FdO2) of about 20%-30%, 21%-30%, 21%-40%, 30%-40%, 40%-50%, 50%-60%, 60%-70%, 70%-80%, 80%-90%, and 90%-100%. In some configurations, respiratory assistance device 10 may include safety thresholds that prevent the user from delivering too much oxygen to the patient.

[0130] High-flow respiratory assistance can be administered to the user's nostrils and / or orally, or via a tracheostomy interface. High-flow respiratory assistance can deliver gas to the user at a rate that meets or exceeds the intended user's peak inspiratory flow requirements. High-flow respiratory assistance can create a flushing effect in the nasopharynx, such that the anatomical dead space in the upper airway is flushed by the incoming high-flow gas stream. This can provide a reservoir of fresh gas available for each breath while minimizing nitrogen and carbon dioxide rebreathing. Meeting inspiratory demand and flushing the airway are even more important when attempting to control the patient's FdO2. High-flow respiratory assistance can be delivered using a non-sealing patient interface, such as a nasal cannula. Nasal cannulae can be configured to deliver respiratory gas to the user's nares at a rate that exceeds the intended user's peak inspiratory flow requirements.

[0131] As used herein, the term "non-sealing patient interface" may refer to an interface that provides a pneumatic link between a patient's airway and a source of gas flow (such as from the flow generator 11) that does not completely obstruct the patient's airway. A non-sealing pneumatic link may include less than about 95% obstruction of the patient's airway. A non-sealing pneumatic link may include less than about 90% obstruction of the patient's airway. A non-sealing pneumatic link may include between about 40% and about 80% obstruction of the patient's airway. The airway may include one or more of the patient's nostrils or mouth. In the case of a nasal cannula, the airway is through the nares.

[0132] The flow generator or blower 11 may include an ambient air inlet port 27 that allows ambient room air to be drawn into the blower.

[0133] The respiratory assistance device 10 may also include an oxygen inlet port 28 that leads to a valve that allows pressurized gas to enter the flow generator or blower 11. The valve may control the flow of oxygen to the flow generator blower 11. The valve may be any type of valve, including a proportional valve or a binary valve.

[0134] The blower can operate at a motor speed greater than about 1,000 RPM and less than about 30,000 RPM, greater than about 2,000 RPM and less than about 21,000 RPM, greater than about 4,000 RPM and less than about 19,000 RPM, or any of the values ​​between these. The operation of the blower can mix the gas entering the blower through the inlet port. Using the blower as a mixer can reduce the pressure drop inherent in systems with separate mixers, such as static mixers that include baffles, due to the energy required for mixing. The presence of a static mixer can also increase the volume of the gas flow path between the valve and the gas composition sensor, which can further increase the delay between when the valve current changes and when a corresponding change in oxygen concentration is measured.

[0135] Based on user input and the therapy delivered by a given device, the controller can determine a target value for an output parameter (e.g., flow rate) of the blower. The controller can receive a measured value of the output parameter and adjust the speed of the blower based on the difference between the target value and the measured value.

[0136] The target output parameter can be a flow rate. The target flow rate can be a constant value. The target flow rate can also be a variable value. In some configurations, the controller controls the blower motor speed based on the target flow rate and can further increase or decrease the motor speed based on the patient's breathing cycle. The target flow rate does not necessarily change, but the controller varies the motor speed to impart oscillations to the instantaneous flow rate in synchronization with the patient's breathing. Such a system is described in International Application PCT / NZ2017 / 050063, filed May 17, 2017, entitled "Flow Path Sensing for Flow Therapy Apparatus."

[0137] 1B, a sensing circuit board 2200 is shown that can be implemented in the respiratory assistance device 10. The sensing circuit board 2200 can be positioned within the sensor chamber such that the sensing circuit board 2200 is at least partially immersed in the gas flow. The gas flow can exit the blower 11 through a conduit and enter a flow path in the sensor chamber. At least some of the sensors on the sensing circuit board 2200 can be positioned within the gas flow to measure gas properties within the flow. After passing through the flow path in the sensor chamber, the gas can exit to the humidifier 12 described above.

[0138] The sensing circuit board 2200 may be a sensing printed circuit board (PCB). Alternatively, the circuitry on the board 2200 may be constructed with electrical wires connecting electronic components instead of being printed on a circuit board. At least a portion of the sensing circuit board 2200 may be mounted outside the gas flow. The gas flow may be generated by the flow generator 11 described above. The sensing circuit board 2200 may include an ultrasonic transducer 2204. The sensing circuit board 2200 may include one or more thermistors 2205. The thermistor 2205 may be configured to measure the temperature of the gas flow. The sensing circuit board 2200 may include a thermistor flow sensor 2206. The sensing circuit board 2200 may include other types of sensors, such as humidity sensors (including humidity-only sensors used with a separate temperature sensor and combination humidity and temperature sensors), sensors that measure barometric pressure, sensors that measure differential pressure, and / or sensors that measure gauge pressure. The thermistor flow sensor 2206 can include a hot wire anemometer, such as a platinum wire, and / or a thermistor, such as a negative temperature coefficient (NTC) or positive temperature coefficient (PTC) thermistor. Other non-limiting examples of heated temperature sensing elements include glass or epoxy encapsulated or unencapsulated thermistors. The thermistor flow sensor 2206 can be configured to measure the flow rate of a gas by being supplied with a constant power, maintained at a constant sensor temperature, or maintained at a temperature that differs by a constant amount from the temperature of the gas flow.

[0139] The sensing circuit board 2200 can include a first portion 2201 and a second portion 2202. The first portion 2201 can be positioned within the gas flow path, and the second portion 2202 can be positioned outside the gas flow path. In Figure 1B, the direction of gas flow is indicated by arrow 2203. The direction of gas flow can be linear or curved, as shown in Figure 1B.

[0140] Positioning one or more of the thermistor 2205 and / or thermistor flow sensor 2206 downstream of the blower and mixer combination can account for heat supplied to the gas flow from the blower. Immersing the temperature-based flow sensor in the flow path can provide a better representation of the characteristics of the gas flow because the immersion exposes the sensor to the conditions within the gas flow.

[0141] The sensing circuit board 2200 may include an ultrasonic transducer, transceiver, or sensor configured to measure a characteristic of the gas flow, such as composition. As will be appreciated, any suitable transducer, transceiver, or sensor may be attached to the sensing circuit board 2200. For example, the sensing circuit board may include an ultrasonic transducer system (also referred to as an ultrasonic sensor system) that employs ultrasonic or sound waves to determine gas concentration.

[0142] The controller 13 can control the conduit heater 16c and / or the humidifier 12 based on feedback from one or more patient-end sensors 26, such as temperature and / or humidity sensors, at the patient-end of the conduit 9. The patient-end sensor 26 may be located at the patient-end of the conduit, for example, in a cuff or connector at the end of the conduit. The patient-end sensor(s) may be located at the patient interface 17. The controller 13 can be configured to determine a temperature drop from the end of the inspiratory conduit 9 to the patient, for example, a 3°C drop, and control the conduit heater 16c and / or the humidifier 12 using feedback control, i.e., using closed-loop control. Such a control method is disclosed in the applicant's prior patent, U.S. Patient No. 8,453,641.

[0143] Referring to FIG. 8, there is provided a circuit 401 that can be utilized to implement a method of measuring temperature using the patient-end sensor 26 to control the temperature and / or dew point of the inhaled gas flow during operation of a device according to the present disclosure, particularly during high temperature and / or cool down modes.

[0144] When a DC heating voltage 401 is applied to heater wire 16A, diode 403 conducts, allowing current to flow through heater wire 16A, which functions normally to provide heating to delivery tube 9. When heating voltage 401 is turned off using switch 407, a measurement voltage 409 having the opposite polarity to heating voltage 401 is applied to heater wire 16A. In this case, the current in heater wire 16A does not flow through diode 403, but rather through patient-end sensor 26, which may be a thermistor, and through reference resistor 411. The voltage across reference resistor 411 can then be measured at output 413 to determine the temperature of the gas. The voltage measurement 413 across reference resistor 411 is converted to temperature using a lookup table or equation, and a temperature value is calculated.

[0145] More generally, the thermistor 26 may be replaced with an impedance (e.g., resistor and capacitive sensor) for pressure or humidity measurements. By measuring the voltage across the reference resistor 411, the impedance can be measured, or by looking at the voltage across the reference resistor 411 in time, the rise time can be determined.

[0146] Portions of the circuit may be included in the delivery conduit 9, in particular, diode 403 and thermistor 26 (which are in parallel with each other) are preferably placed in series with heater wire 16A at or near the end of the delivery conduit 9 closest to the patient. For example, they may be interconnected on a printed circuit board, overmolded with plastic for sealing, and mounted in the gas flow through delivery conduit 9. Additionally, the circuit may be formed by interconnected components in a housing, e.g., a plastic housing, that protrudes from the plastic wall of the delivery tube into the gas flow through the conduit to measure that gas property. All other components of the circuit, including reference resistor 411 and switching circuit 407, are included in the control circuitry of device 100.

[0147] The values ​​of the thermistors 26 can be selected to have different resistance curves with known characteristics at ambient temperatures. Selection of a particular thermistor value for use in the circuit allows the controller 13 to identify and match that thermistor value with a given conduit or tubing 9 and / or patient interface 17. Different thermistor values ​​can be matched with particular appropriate conduit and / or patient interface types, and when a conduit 9 is connected to the device 100, the controller 13 can identify that thermistor 26 and apply an appropriate control strategy to the heating of the conduit 9.

[0148] By positioning the sensors, for example, within the flow path rather than outside the flow path, the transducers 2204 can operate within a smaller temperature range relative to each other, or together at substantially one temperature (i.e., the temperature of the gas flow). Because the transducers are sensitive to temperature, having them at a substantially homogenous temperature improves accuracy. Additionally, positioning the sensors along the flow path allows measurements and calculations to take into account the effects of gas velocity, thereby removing the effects of gas velocity from the sensor measurements.

[0149] In some configurations, the respiratory assistance device may also be provided with a humidity sensor located in the flow path and configured to generate a humidity signal indicative of the humidity of the gas stream flowing through the sensor assembly. In such configurations, the gas composition may be determined by the sensed speed of sound, as well as the sensed temperature and / or the sensed humidity. The humidity sensor may be a relative humidity sensor or an absolute humidity sensor. In some embodiments, the gas composition may be determined based on the sensed speed of sound and the sensed humidity without the need for a temperature sensor.

[0150] Some examples of respiratory assistance apparatus are disclosed in International Application No. PCT / NZ2016 / 050193, entitled "Flow Path Sensing for Flow Therapy Apparatus," filed December 2, 2016, and International Application No. PCT / IB2016 / 053761, entitled "Breathing Assistance Apparatus," filed June 24, 2016, and U.S. Patent No. 8,453,641, filed August 19, 2005, each of which is incorporated herein by reference in its entirety. Examples of respiratory assistance apparatus configurations that can be used in embodiments of the present disclosure are discussed in more detail below.

[0151] The various configurations described are merely exemplary configurations: any one or more features from any of the configurations may be used in combination with any one or more features from any of the other configurations.

[0152] The device 10 includes a controller 13. The controller 13 may include one or more electronic data processors operating according to a combination of hardware, firmware, and software. The controller 13 may include one or more memory units. The controller 13 may include one or more sub-controllers. A separate controller may be provided to control each component of the device 10, e.g., a controller for the flow generator, a controller for the humidifier, etc. Use of the term "controller" may refer to any of these configurations.

[0153] Apparatus 10 further includes an input / output device 14 in the form of one or more user interfaces configured to enable a user to input one or more control signals to controller 13. Conveniently, input / output device 14 may be configured to provide one or more graphical user interfaces to the user to enable the user to view and control operating parameters of apparatus 10. Input / output device 14 may include a touch screen interface.

[0154] The controller 13 is configured to control the device 10 to deliver a high flow rate of gas to the patient, as described above. In particular, the controller 13 controls the flow generator to generate a gas flow at a desired flow rate. The controller 13 also controls the humidifier to heat and humidify the gas flow before delivery to the patient. The controller can control the humidifier to heat the gas flow to a temperature setpoint. The temperature setpoint can be determined based on the desired gas flow dew point. The dew point is a function of both the gas flow temperature and the gas flow humidity. Control of both of these parameters allows for dew point control. The controller may also or alternatively control the humidifier to humidify the gas flow to a measured or calculated humidity (where, for a given gas flow temperature, changes in humidity result in changes in dew point).

[0155] The controller 13 is configured to control the device 10 in a normal mode and a high temperature mode. In both modes, the device 10 can be configured to control both the temperature and humidity of the gas stream, thus ensuring that the device can deliver the gas stream at a desired dew point (typically known as the setpoint). Changing the dew point setpoint, either by the user or automatically by the controller, controls the device to change the temperature and / or humidity of the gas stream to deliver the gas stream at the dew point setpoint. These modes can be manually selected by the user using the user interface 14. In both modes, a high flow rate of gas is generated and delivered to the patient. In the normal mode, the flow rate of the gas stream delivered to the patient is, for example, as described above in paragraph

[0135] for the normal high flow rate. In the normal mode, the dew point of the gas stream delivered to the patient is typically below 39°C, more typically in the range of 31-37°C. In the high temperature mode, the dew point of the gas stream delivered to the patient is higher than in the normal mode, particularly in the range of 43-50°C. The temperature in the high temperature mode can be in the range of 41-50°C. The temperature in the high temperature mode may be in the range of 41-49°C. The temperature in the high temperature mode may be in the range of 43-47°C. In other words, the gas stream temperature setpoint at which the apparatus attempts to deliver the gas stream is higher in the high temperature mode than in the normal mode. The apparatus 10 is configured to increase the dew point of the gas stream between the two modes so that gas is delivered at a higher dew point in the high temperature mode.

[0156] When providing the high temperature mode, the device 10 operates according to one or more safety algorithms that ensure the characteristics of the gas flow delivered to the patient are safe both during and after the high temperature mode. These safety algorithms control the gas flow to ensure that the thermal energy and / or enthalpy in the gas flow remains below safe levels. Thus, the safety algorithms may operate according to parameters including gas temperature, gas dew point, gas flow rate, and / or the duration of the high temperature mode and the subsequent cool down mode. A method for controlling the device 10 during the high temperature mode is described below with reference to FIG. 2. A method for controlling the device 10 according to the subsequent cool down mode is described below with reference to FIG. 3.

[0157] Referring first to FIG. 2, when the high temperature mode is selected by the user, the controller 13 receives an instruction from the user to enter the high temperature mode (201).

[0158] In step 201A, the device 10 is controlled to warm up. In particular, the humidifier heater plate and / or conduit heater 16c warm up. As the device begins to warm up toward the higher temperature setpoint of the high temperature mode, the controller 13 begins executing a high temperature control algorithm, or at least a first part of such algorithm (labeled "Part 1" in the figure), in step 203 to help keep the patient safe during the high temperature mode session, i.e., not experiencing excessive enthalpy / dew point during that treatment session. Part 1 follows the process shown in FIG. 2.

[0159] Once device 10 has warmed up in step 203, hyperthermia therapy, i.e., an inspiratory gas flow at a high temperature, is provided to the patient. Once hyperthermia therapy begins, a timer is started in step 204, providing a timing signal that controller 13 uses to limit the duration of the hyperthermia mode to a predetermined or user-programmed duration. In step 204, device 10 continues to operate in the hyperthermia mode until either the duration limit is reached, as in step 206A, or the user instructs device 10 to terminate the hyperthermia mode in step 206B. Thereafter, device 10 terminates the hyperthermia mode in step 207.

[0160] If the user wishes to continue using the device 10, they may do so in step 208. Alternatively, the user may terminate all therapy in step 209. In step 208, the user may select one or more new operating parameters, such as a temperature setpoint or flow rate, for continuing therapy. As described below with reference to FIG. 3, the device 10 is then controlled in step 210 according to a cool-down mode, in which one or more parameters of gas flow to the patient are controlled so that the gas flow remains safe for the patient.

[0161] 3, following termination of the high temperature mode, the apparatus 10 operates in accordance with a cool down mode. In the cool down mode, step 301, the apparatus 10 receives instructions from the user regarding desired parameters of the gas flow, such as temperature setpoint and / or flow rate. Such instructions may be received via the user interface 14 or via the remote management system 101, as further described below.

[0162] In step 302, the device is controlled according to one or more initial safety processes. These safety processes include any one or more of gradually decreasing the flow rate towards the cool down mode flow rate setpoint, setting the humidifier heater plate PWM to zero for a predetermined period of time, and setting the maximum end-of-hose temperature to a predetermined value considered safe for the user. The end-of-hose temperature can be measured by the patient-end sensor 26 and feedback control can be used by the controller accordingly.

[0163] Once one or more safety processes have been set, the controller waits at 303 until the measured temperature falls below a predetermined maximum safe temperature as in step 304A, or until a predetermined period of time has passed as in step 304B. Step 304A can use the temperature measured anywhere downstream of the humidifier, for example, at the humidifier outlet or at the end of the hose using patient-end sensor 26. The predetermined period of time can be 30 minutes in one example.

[0164] In step 305, the device verifies that one of steps 304A or 304B is satisfied, and if so, proceeds to step 306, where it exits cool-down mode and transitions the device to normal mode. During this transition, the device returns the humidifier heater plate PWM to its normal value or range of values ​​and gradually increases the temperature at the end of the hose, as measured by the patient-end sensor 26, towards the normal set point.

[0165] When executing the first portion of this algorithm, i.e., the high temperature mode, the controller reduces the peak flow rate of the gas stream from the higher peak flow rate used in the normal mode. The controller 13 may also narrow the range of selectable flow rates (i.e., the range of flow rates that the user can select) when in the high temperature mode. For example, the range of selectable flow rates may be changed from 10-70 L / min to a narrower range of 30-40 L / min, 30-70 L / min, or 10-40 L / min. The controller 13 may reduce the range of flow rates to be a predetermined amount lower than the range of flow rates used in the normal mode. For example, the range of flow rates may be reduced by 15 L / min or 10 L / min. The controller 13 may also increase or decrease the upper and / or lower limits of the flow rate range. It may be appropriate to increase the upper limit of the flow rate range to prevent residual energy in the system from rapidly increasing the temperature of the gas stream. Similarly, it may be appropriate to increase the lower limit of the flow rate range.

[0166] Once the device 10 warms up, the controller 13 initiates a high temperature mode as a high temperature session in which the gas flow is delivered at the high temperature indicated above, and simultaneously starts a session timer. The user and / or patient can control the controller 13 to initiate the high temperature mode. As described above, in the high temperature mode, the gas flow is controlled to a temperature range whose peak temperature is higher than the peak temperature of the temperature range used in the normal mode. The controller 13 terminates the high temperature session when the session timer reaches a safety limit or when the user instructs the device 10 to terminate the high temperature mode. At this point, the controller 13 has reached the end of the first part of the high temperature control algorithm (labeled "Part 1" in the figure). The safety limit is a set duration determined by reference to the timer, typically 120 minutes or less. The user can set a time less than the maximum the device will allow in the high temperature mode, for example, 30 or 60 minutes. The set duration can be determined by reference to a counter (a predetermined number of counts that will end the high temperature mode). The timer or counter can be generated by an algorithm in the controller 13, or the controller 13 can be configured to receive a timer or counter signal from another controller (e.g., a dedicated timer / counter controller) or from a remote device (e.g., remote device 103 via the remote management system 01, as described below). As the apparatus 10 warms up, a message can be provided on the screen of the user interface 14 or a message can be sent to the patient's mobile device. Once the warm-up mode is complete, another message can be presented on the user interface 14 or sent to the patient.

[0167] If the user desires to continue using the device in normal mode (e.g., with a dew point setpoint below 40°C and a flow rate setpoint below a predetermined threshold), the controller begins executing the second part of the high temperature mode algorithm (labeled "Part 2" in the figure), which is a cool-down mode configured to help keep the patient safe while the device cools. Note that the threshold may be preset (e.g., factory set) or may be a function of the flow rate used during high temperature mode. In either case, the threshold represents the highest flow rate the device can quickly transition to after high temperature mode without causing a spike in the dew point (and / or enthalpy) of the gas flow. Such a spike may occur due to residual energy in the device if the device transitions too quickly from high temperature mode to normal mode (at a low flow rate).

[0168] In cool-down mode, the controller gradually changes the gas flow rate to its new setpoint and reduces the power supplied to the humidifier heater plate. The cool-down mode follows the process shown in Figure 3. The controller may reduce the power supplied to the heater plate, for example, by setting the heater plate PWM to zero for at least a predetermined time. The power supplied to the heater plate may alternatively or additionally be controlled by controlling the heater plate duty cycle or the voltage and / or current supplied to the heater plate. In cool-down mode, the controller 13 also sets the maximum gas flow temperature setpoint at a predetermined point downstream of the humidifier to a predetermined value for at least a predetermined time.

[0169] Thus, the controller 13 operates to control the rate of change of the gas flow rate as the gas flow rate transitions from the rate used in the high temperature mode to the rate used subsequently in the normal mode. This helps ensure that the flow rate is not reduced too quickly while there is still thermal energy in the device (thermal energy generated during the just-completed high temperature mode). As can be seen in FIG. 6 and further explained below, if the flow rate is reduced to too low a value, relatively little gas will pass through the system, but the residual thermal energy will be relatively high. This can result in excessive heating of the gas flow during cool down, raising the dew point / enthalpy of the gas to levels harmful to the patient.

[0170] The controller 13 also operates to at least reduce the electrical energy supplied to the humidifier heater during the cool-down mode, and can reduce that electrical energy to zero. This ensures that the heater does not add heat energy to the thermal system during cool-down, further helping to ensure that gas temperatures remain below safe levels. If the device 10 includes a conduit heater 16c in the gas delivery conduit 9 to the patient, the electrical energy supplied to such conduit heater 16c can also be controlled as needed.

[0171] Additionally, the device 10 operates according to a new dew point setpoint for the gas stream, which is preferably within the temperature range of the normal mode. This new dew point setpoint may be set by the user. This helps ensure that the temperature of the gas stream does not exceed a safe level during cool-down. Thus, the device 10 is configured to manage potentially high thermal energy / enthalpy residue in the device's components immediately after the high-temperature mode, thereby minimizing the possibility of the patient being exposed to a gas stream having a dew point and / or enthalpy above a safe level.

[0172] Once the temperature measured downstream of the humidifier, e.g., at the patient interface, falls below a threshold and / or a predetermined time has passed since the humidifier heater PWM was reduced or set to zero, the controller will return the humidifier heater PWM to its normal value range (as used during normal mode) and gradually increase the end-of-hose gas flow temperature toward its new temperature setpoint (as used during normal mode), at which point the controller has reached the end of the second portion of the high temperature algorithm.

[0173] FIG. 4 shows an example of a screen shot of the graphic user interface of the user interface 14 for details A, B and C of FIG.

[0174] In one example, a user can initiate a version of the high temperature mode (in this example, "41°C mode") by first navigating to a "Set Dew Point" screen on the high flow device's graphic user interface (GUI) according to FIG. 4A. From this screen, the user presses a virtual "41°C mode" button (which can display a different dew point if the specified high temperature mode dew point is different). This button causes the GUI to display a screen informing the user that the high temperature 41°C mode has been selected (FIG. 4B). This screen has a virtual "Confirm" button. Note that the virtual buttons on the GUI can be replaced or supplemented with electromechanical buttons adjacent to the non-touchscreen display.

[0175] When the user presses the virtual "Confirm" button, the safety algorithm described above immediately narrows the range of selectable flow rates by changing one or both of the minimum and maximum flow rate range limits (e.g., the selectable flow rate range may change from 10-70 L / min to 30-40 L / min, 30-70 L / min, or 10-40 L / min). When this button is pressed, the safety algorithm also begins raising the dew point of the gas stream toward the setpoint used in high temperature mode, e.g., 41°C. While the device is raising the dew point, the GUI displays a screen informing the user that the device is "warming up to 41°C mode" (Figure 4C).

[0176] When the device increases the set temperature to 41°C, high temperature mode ("41°C mode" in this example) begins. As soon as the device enters 41°C mode, a safety algorithm starts a timer that counts down from (or to) a set duration, such as two hours. This set duration defines the maximum duration the device can operate in high temperature mode. The user can choose to have this timer displayed on the GUI during 41°C mode (see, for example, Figure 5). The user can manually exit high temperature mode before the maximum duration is reached. If the user does not manually exit high temperature mode, the device will automatically exit high temperature mode and enter cool down mode once the maximum duration is reached.

[0177] To understand the importance of the cool-down mode, with reference to FIG. 6, consider a use case in which the user selects a flow rate below 30 L / min (but above 0 L / min) immediately after the device has exited hot mode. If the flow rate is immediately reduced before the humidifier chamber temperature has time to drop below its hot mode setting, the amount of heat absorbed by each unit volume of respiratory gas increases, causing a sudden increase (spike) in the enthalpy (and / or dew point) of the gas flow at the patient interface. This spike occurs because the water takes time to cool, even if the electrical energy supplied to the humidifier heater is switched to 0% as soon as the flow rate is reduced. Eventually, the water cools and the enthalpy decreases, but the enthalpy spike may be large enough to exceed safe enthalpy limits (as in the example shown in FIG. 6).

[0178] In accordance with the present disclosure, there is also provided a respiratory assistance device 10 in which the flow generator is omitted. The device 10 still includes the humidifier 12 and other components as described above and shown in FIG. 1A. Such a respiratory assistance device includes one or more gas inlets configured to receive one or more gases from one or more external gas supplies. The external gas supplies may include, for example, a hospital wall oxygen supply or a supply gas from a gas canister or tank.

[0179] In such respiratory assistance devices, the controller 13 does not control the gas flow through the device. The gas flow from the external gas supply may be manually controlled by a user of the device 10, for example, by adjusting a flow valve on the external gas supply. The controller of the device 10 may be configured to generate one or more gas flow reminders and / or alarms when or shortly after the high temperature mode is activated. The gas flow reminders are configured to remind the user to ensure that the flow rate is within an acceptable range for operation in the high temperature mode. This may or may not require a reduction in the gas flow rate from the external gas supply. If the user does not reduce the gas flow rate, for example, after a predetermined time after activation of the high temperature mode, one or more alarms may be activated. One or more flow sensors may be provided to measure the gas flow rate from the or each external gas supply, and the flow sensors are used by the controller to generate one or more reminders and / or alarms. When the high temperature mode is terminated, it is still important that the flow rate of gas delivered to the patient remain within a safe flow rate range to ensure that residual energy in the system does not cause a temperature spike in the gas flow, for reasons discussed above. As a result, during the cool-down mode, the controller of the device 10 can be configured to generate one or more gas flow rate reminders and / or alarms when the high temperature mode is terminated. The gas flow rate reminders are configured to remind the user to ensure that the flow rate should be controlled to remain within an acceptable range for operation in the cool-down mode. This may require that the gas flow rate from the external gas supply be maintained for a predetermined period of time, or at least maintained above a minimum threshold. If the gas flow rate drops below the acceptable range or minimum threshold, for example, a predetermined time after initiation of the high temperature mode, one or more alarms can be activated.

[0180] Control of the electrical energy supplied to the humidifier heater was described above. The humidifier heater is the primary mechanism for heating the gas flow. The patient conduit that delivers the gas flow from the humidifier to the patient interface can also be heated via a conduit heater. The algorithms described above can also control the conduit heater as part of the high temperature and cool down modes.

[0181] There are many techniques for controlling the electrical energy supplied to the humidifier heater. One of these is pulse wave modulation (PWM), as mentioned in the example above. The PWM can be controlled to provide controlled heating and humidification of the gas flow during high temperature and cool down modes, as described above. The duty cycle of the humidifier heater can be controlled as well. This disclosure contemplates that any other technique can be used to control power to the humidifier heater. The humidifier heater typically comprises a heater plate, although other types of humidifier heaters are also contemplated.

[0182] 7, the device 10 can be configured to communicate with a remote management system 101, which can be hosted on one or more servers. The remote management system 101 can be cloud-based or hosted on a network, such as a hospital, where the device 10 is used.

[0183] The remote management system 101 can communicate with a remote device 103, such as a smartphone, tablet, laptop, or any other type of remote electronic processing device.

[0184] The apparatus 10, the remote management system 101 and the remote device 103 can communicate via a wired or wireless communication interface 105, shown in dashed lines in FIG.

[0185] The remote management system 101 can be used for patient management.

[0186] For example, the remote management system 101 may be configured to remotely control one or more aspects of the device 10 and / or may be configured to receive and / or transmit data between the device 10, the remote management system 101, and the remote device 103.

[0187] The remote management system can be configured to control the controller 13 to control one or more aspects of the operation of the device, including, but not limited to, operating the flow generator 11 to generate a flow of gas (gas flow) for delivery to the patient, operating the humidifier 12 (if present) to humidify and / or heat the generated gas flow, controlling the flow of oxygen to the flow generator blower, receiving user input from the remote device 103 for reconfiguration and / or user-defined operation of the device 10, and outputting information to the remote device 103.

[0188] In one embodiment, the remote management system 101 simply receives the usage data and presents and / or stores the information. For example, the remote management system 101 can store data indicating use of the device in a high temperature mode.

[0189] Alternatively, the remote management system 101 receives, displays, and / or stores patient data, usage data, and treatment data, which information can be accessed by a physician, patient, or other party.

[0190] Optionally, the remote management system 101 can send control data to the device, for example new treatment parameters to the device 100, which then operates according to those new treatment parameters or parameters.

[0191] This sending of control data may be in lieu of receiving data from the device.

[0192] The remote management system may receive usage and / or treatment data directly from the device 10 via the communication interface 105 .

[0193] The usage data may include: a. the amount of time the device 10 is used within a given period of time; b. the length of each period of use; c. Patient compliance with prescribed treatment. For example, such data may include the number of minutes / hours / days the patient is receiving treatment, the start time of treatment, and the end time of treatment.

[0194] The treatment data may include: a. one or more treatment parameters, such as humidity or dew point or flow rate, or SpO2, or parameters related to high temperature mode; b. The number of times the high temperature mode has been used, and / or c. Number of times the high temperature mode is used per day.

[0195] The usage and treatment data may be transmitted to the remote management system 101 at the end of each treatment session or at least once every 24 hours. For example, the usage and treatment data may be transmitted a predetermined time after treatment has ended. In one example, the usage and treatment data may be transmitted during a drying mode that is activated after treatment has ended. The usage and treatment data may be transmitted to the remote device 101, which may be, for example, the patient's phone.

[0196] Optionally, after the high temperature mode has ended, the device 10 may be controlled according to a dry mode, for example, when the patient presses the off button to end treatment.

[0197] In the drying mode, the device 10 generates a message instructing the patient and / or user not to use the device 10. For example, the message may include an on-screen instruction on the user interface 14 or an instruction on the remote device 103.

[0198] The dry mode can operate for a predetermined time, e.g., 60 to 120 minutes, preferably about 90 minutes. In dry mode, the power to the humidifier heater plate is turned off or reduced to very low power, e.g., less than 5 W, and the conduit heater wire 16c is powered to its maximum. The flow generator 11 is controlled at a set flow rate, e.g., 10 to 30 L / min, for the duration of the dry mode. The dry mode dries out any condensate that may form in the conduit 9. This can be particularly useful because use of the high-temperature mode can increase the dew point, which can lead to more condensate being generated when the device transitions from the high-temperature mode.

[0199] The communication interface 105 may include a modem, a Wifi router, and / or a Bluetooth.

[0200] The remote management system 101 and the remote device 103 can be configured to mirror the display of the user interface 14 on the remote device 103 to transmit real-time data to the remote device 103. For example, one, some, or all of the various GUIs of the user interface 14 may be mirrored. For example, flow reduction instructions displayed on the user interface 14 may be transmitted to and presented on the patient's mobile phone. This can help guide the patient on how to use the high temperature mode. Warnings and / or alarms can also be displayed on the remote device 103. The real-time date may include a countdown timer. The timer may be within the controller 13 of the apparatus 10. Alternatively, the timer can be generated by the remote management system 101 and / or the remote device 103, for example, by the patient's phone. For example, a clock or timer function on the mobile phone can be used to time the duration of the high temperature mode. This may be the case if the patient is asleep or otherwise distracted, for example, watching television or reading a book, while the apparatus is operating in the high temperature mode. This reminder system ensures that the patient remains safe when operating in high temperature mode.

[0201] The patient management system 101 can be configured to receive and store data indicative of usage of the device 10, for example usage of the high temperature mode. This information may be included in a treatment report generated by the patient management system 101 or generated remotely from data stored in the patient management system 101. This report may be sent to the patient's remote device 103 or may be sent / accessed to the patient's clinician / physician's remote device 103.

[0202] Alternative cool-down modes are also envisioned as modifications to, or in place of, the cool-down mode described above with reference to FIG.

[0203] For example, in another example of a cool-down mode, the humidifier heater plate and / or conduit heater wire 16c are reduced to low power or zero. The temperature at the patient end of the conduit 9 is measured using the patient-end sensor 26. Optionally, there may be a temperature sensor 3b at the outlet of the humidifier 12 (e.g., in the gas path downstream of the humidifier 12, adjacent to the humidifier outlet). Optionally, the temperature at the outlet of the humidifier 12 may be measured. If any of the measured patient-end temperatures falls below 37°C, the flow generator 11 may be controlled so that the flow rate may be changed to a set flow rate set by the user. Alternatively, the flow rate is changed if the temperature at the outlet of the humidifier 12 falls below 37°C.

[0204] This modified cool-down mode is a modification of step 302 described above with reference to Figure 3. In this modified cool-down mode, the flow rate is not changed until the temperature (at the patient end of the conduit and / or at the outlet of the humidifier 12) falls below a predetermined threshold.

[0205] In another possible variation of the cool down mode step 302, upon exiting the high temperature mode, the flow rate may not be increased or decreased. This may be because the set or treatment flow rate has not changed. In that case, the power to the humidifier heater plate and / or conduit heater 16c may be set to 0 or reduced to a low power, e.g., less than 5 W, to allow the temperature to drop.

[0206] It is envisioned that once the temperature at the patient end and / or at the outlet of the humidifier 12 falls below a safety temperature threshold, for example 37°C, the selectable flow rates can only be expanded to the normal mode flow rate range.

[0207] During cool-down mode, once the high temperature mode is terminated, it is also envisioned that the device 10 will default to providing the patient with a humidity setting of 37°C dew point. Humidity settings may be locked to prevent the user from changing these humidity settings while in high temperature mode. The humidity setting may be changeable once a timer expires or the user exits high temperature mode. If the user changes the humidity setting to a humidity setting lower than 37°C dew point, such as 34°C dew point or 31°C dew point, the device 10 is configured to reduce (or turn off) the humidifier heater plate power and / or heater wire 16c power at least until the patient-end temperature measured by the patient-end sensor 26 indicates a temperature corresponding to the currently set humidity setting. Alternatively, the controller 13 uses sensor 3b to measure the humidifier chamber outlet temperature until it reaches the set humidity. Once the temperature is at the current setting, normal humidity control (i.e., normal control of the humidifier heater plate power and / or heater wire 16c) resumes.

[0208] The devices and methods of the present disclosure advantageously allow for the safe delivery of respiratory gases to a patient at higher temperatures than prior art respiratory treatment devices for treating respiratory illnesses, particularly those of the upper respiratory tract, caused by viruses and / or bacteria. The high-temperature mode of the present disclosure delivers gases at higher energy levels than the normal or normal treatment mode. The higher energy of the gas provides more energy to the patient's upper respiratory tract. The higher energy can cause viral denaturation and / or limit or stop viral replication, thereby reducing symptoms and improving the patient's condition. The devices and methods of the present disclosure also facilitate a safe transition of gas flow from the high-temperature mode back to the normal mode. Additionally, the flow rate range can be limited while in the high-temperature mode, thereby providing a safe high-temperature mode and reducing the possibility of excessive enthalpy or excessive electrical current being applied to the patient. Additionally, safety features are provided to ensure patient safety even after the high-temperature mode has ended.

[0209] The apparatus and methods of the present disclosure allow these high temperature gases to be delivered safely, and also provide one or more safety features to control increased energy residue in the system once the high temperature mode has ended.

[0210] International Application No. PCT / NZ2017 / 050119, filed September 13, 2017, entitled "Thermistor Flow Sensor Having Multiple Temperature Points," International Application No. PCT / NZ2016 / 050193, filed December 2, 2016, entitled "Flow Path Sensing for Respiratory support Apparatus," and U.S. Patent No. 8,453,641, filed August 19, 2005, are incorporated herein by reference in their entireties.

[0211] The reference to any prior art in this specification is not, and should not be construed as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavor in any country throughout the world.

[0212] When reference is made herein to directional terms such as "upper," "lower," "forward," "rearward," "horizontal," "vertical," etc., these terms refer to the device when in a typical in-use position and are used to indicate and / or describe relative directions or orientations.

[0213] Unless the context clearly requires otherwise, throughout this specification and claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense, i.e., in the sense of "including but not limited to", as opposed to an exclusive or exhaustive sense.

[0214] As used herein, the terms "approximately," "about," and "substantially" refer to an amount close to the stated amount that still performs the desired function or achieves the desired result. For example, in some embodiments, where the context allows, the terms "approximately," "about," and "substantially" can refer to an amount that is within 10% or less, within 5% or less, and within 1% or less of the stated amount.

[0215] The reference to any prior art in this specification is not, and should not be construed as, an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavor in any country throughout the world.

[0216] The disclosed apparatus and systems may be broadly described as consisting of the parts, elements and features (in any or all combinations of two or more of said parts, elements or features) individually or collectively referred to or shown in the specification of this application.

[0217] Where reference has been made in the above description to whole entities or components that have known equivalents, those whole entities are incorporated herein as if individually set forth.

[0218] Depending on the embodiment, some acts, events, or functions of any of the algorithms, methods, or processes described herein may be performed in a differing order, added, combined, or omitted entirely (e.g., not all described acts or events are required to implement an algorithm). Furthermore, in some embodiments, acts or events may be performed simultaneously rather than sequentially, for example, through multithreading, interrupt processing, or multiple processors or processor cores, or on other parallel architectures.

[0219] It should be noted that various modifications and variations to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such modifications and variations can be made without departing from the spirit and scope of the disclosed apparatus and system and without diminishing its attendant benefits. For example, various components can be rearranged as desired. Accordingly, such modifications and variations are intended to be included within the scope of the disclosed apparatus and system. Moreover, not all features, aspects, and advantages are necessarily required to implement the disclosed apparatus and system. Accordingly, the scope of the disclosed apparatus and system is intended to be defined solely by the scope of the following claims.

Claims

1. 1. A respiratory assistance apparatus configured to provide a flow of gas to a patient, comprising: a flow generator configured to generate a gas flow; a humidifier configured to humidify the gas stream; a controller, wherein the device is controlled by the controller to function in at least two modes, a normal mode and a high temperature mode, and when in the high temperature mode, the temperature of gas delivered to the patient is higher than the temperature of gas delivered to the patient in the normal mode; Equipped with The respiratory assistance apparatus wherein, in the high temperature mode, the controller limits the duration of the high temperature mode to a maximum duration.

2. The apparatus of claim 1 , wherein the controller uses a signal generated by a timer to limit the duration of the high temperature mode.

3. 3. The device according to claim 2, wherein the set duration is between 15 and 180 minutes, preferably between 20 and 120 minutes, more preferably between 30 and 90 minutes.

4. The apparatus of claim 1 , wherein the controller uses a signal generated by a counter to limit the duration of the high temperature mode.

5. The device according to any one of claims 2 to 4, wherein said device generates said signal.

6. The apparatus of claim 5 , wherein the apparatus comprises a further controller configured to generate the signal.

7. The apparatus of any one of claims 2 to 4, wherein the apparatus receives a signal from a remote device.

8. 7. Apparatus according to any one of claims 3 to 6, wherein the apparatus is configured to be controlled by the controller in a further mode, which is a cool down mode, the cool down mode being activated after the high temperature mode has ended.

9. When in the cool down mode, a) the flow rate is controlled to a flow rate setpoint, and the rate of change of the flow rate from the flow rate used during a high temperature mode to the flow rate setpoint is controlled to be less than a predetermined threshold; b. The power supplied to the heater of the humidifier is reduced from the power used during normal mode and / or high temperature mode; and / or c. the temperature setpoint of the gas flow delivered to the patient is reduced below the temperature setpoint during a high temperature mode; 9. The apparatus of claim 8, wherein the first and second inputs are any one or more of:

10. 10. Apparatus according to any one of claims 1 to 9, wherein in the cool down mode the apparatus is controlled to a gas flow temperature setpoint of 40°C or less.

11. 11. Apparatus according to any one of claims 1 to 10, wherein in the cool down mode the apparatus is controlled to generate a gas flow at a flow rate within a first range of flow rates generated in the normal mode.

12. 12. Apparatus according to any one of claims 1 to 11, wherein in the cool down mode the apparatus is controlled such that the enthalpy and / or dew point of the gas flow is reduced below the enthalpy and / or dew point of the high temperature mode.

13. An apparatus according to any preceding claim, wherein when in the high temperature mode the gas flow to the patient is at a temperature in the range of 41 to 50°C, preferably 43 to 47°C.

14. The method of claim 13, wherein in the normal mode, the controller controls the flow generator to generate the gas flow at a flow rate within a first flow rate range limited by a first peak flow rate; In the high temperature mode, the controller controls the flow generator to generate the gas flow at a flow rate within a second flow rate range bounded by a second peak flow rate, the second peak flow rate being lower than the first peak flow rate in the normal mode. An apparatus according to any one of claims 1 to 13.

15. The device is controlled by the controller to reduce the peak flow rate from the first peak flow rate to the second peak flow rate upon start-up of the high temperature mode; and / or Upon initiation of the high temperature mode, the device is controlled by the controller to decrease the flow rate range from the first flow rate range to the second flow rate range.

15. The apparatus of claim 14.

Images