Control of components of a breathing assistance apparatus

Abstract

A device is disclosed in which the controller of the device is configured to control at least one heater according to a first control scheme when powered by a battery and according to a second control scheme when powered by an AC power source.

Description

[Technical Field]

[0001] This disclosure relates to the control of components of a respiratory assist device. [Previous Technology]

[0002] Background Technology

[0003] Respiratory assist devices are used to deliver a gas flow to a patient in various environments, such as hospitals, medical facilities, inpatient care, or home environments. Respiratory assist devices (e.g., flow therapy devices) may include an oxygen inlet that enables the breathing device to deliver supplemental oxygen along with the gas flow. Respiratory assist devices may also (or alternatively) include a humidification device that enables the breathing device to deliver heated and humidified gas. Respiratory assist devices may allow for the adjustment and control of the characteristics of the gas flow. These characteristics may include, for example, flow rate, temperature, gas concentration (e.g., supplemental oxygen concentration), humidity, and pressure.

[0004] Patients with a variety of health conditions and diseases can benefit from respiratory support (e.g., respiratory therapy). In at least one form, respiratory therapy can be oxygen therapy. For example, patients with chronic obstructive pulmonary disease (COPD), pneumonia, asthma, bronchiectasis, heart failure, cystic fibrosis, sleep apnea, lung disease, respiratory trauma, acute respiratory distress, and / or other conditions or diseases can benefit from respiratory therapy. Similarly, patients receiving oxygen before and after surgery can also benefit from respiratory therapy. [Summary of the Invention]

[0005] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a flow generator configured to generate a gas flow; a humidifier configured to be pneumatically connected to the flow generator and to humidify the gas flow generated by the flow generator, wherein the humidifier includes a heater; wherein the device is configured to be connected to a conduit for delivering the gas flow; a battery configured to be powered by the battery or mains power; and a controller configured to control the heater of the humidifier according to at least a first control scheme and a second control scheme. When the device is powered by the battery, the controller is configured to control the heater of the humidifier according to the first control scheme, the first control scheme including providing a high-frequency pulse width modulation signal to the heater of the humidifier, and wherein when the device is powered by the mains power supply, the controller is configured to control the heater of the humidifier according to the second control scheme, the second control scheme including providing a low-frequency pulse width modulation signal to the heater of the humidifier, and wherein the frequency of the high-frequency pulse width modulation signal is greater than the frequency of the low-frequency pulse width modulation signal.

[0006] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a flow generator configured to generate a gas flow; a humidifier configured to be pneumatically connected to the flow generator and to humidify the gas flow generated by the flow generator, wherein the device is configured to be connected to a conduit for conveying the gas flow, wherein the conduit includes a heater configured to heat the gas flow within the conduit; a battery, wherein the device is configured to be powered by the battery or mains power; and a controller configured to control the heater of the conduit according to at least a first control scheme and a second control scheme. When the device is powered by the battery, the controller is configured to control the heater of the conduit according to a first control scheme, the first control scheme including controlling the heater of the conduit by analog control, and when the device is powered by the mains power supply, the controller is configured to control the heater of the conduit according to a second control scheme, the second control scheme including controlling the heater of the conduit by digital control (digital control including pulse width modulation as needed).

[0007] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a flow generator configured to generate a gas flow; a humidifier configured to be pneumatically connected to the flow generator and to humidify the gas flow generated by the flow generator, wherein the humidifier includes a heater; the device is configured to be connected to a conduit for conveying the gas flow, wherein the conduit includes a heater configured to heat the gas flow within the conduit; a battery, wherein the device is configured to be powered by the battery or mains power; and a controller configured to control the heater of the conduit according to at least a first control scheme and a second control scheme. When the device is powered by the battery, the controller is configured to control the heater of the duct and the heater of the humidifier according to a first control scheme, the first control scheme including controlling the heater of the duct by analog control and providing a high-frequency pulse width modulation signal to the heater of the humidifier, and wherein when the device is powered by AC power, the controller is configured to control the heater according to a second control scheme, the second control scheme including controlling the heater of the duct by digital control (if necessary, by providing a pulse width modulation signal) and providing a low-frequency pulse width modulation signal to the heater of the humidifier, and wherein the frequency of the high-frequency pulse width modulation signal is greater than the frequency of the low-frequency pulse width modulation signal.

[0008] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a flow generator configured to generate a gas flow; a humidifier configured to be pneumatically connected to the flow generator and to humidify the gas flow generated by the flow generator, wherein the humidifier includes a heater; the device is configured to be connected to a conduit for conveying the gas flow, wherein the conduit includes a heater configured to heat the gas flow within the conduit; a battery, wherein the device is configured to be powered by the battery or mains power; and a controller configured to control the heater of the conduit and the heater of the humidifier according to at least a first control scheme and a second control scheme. When the device is powered by the battery, the controller is configured to control the heater of the duct and the heater of the humidifier according to a first control scheme, the first control scheme including controlling the heater of the duct by analog control and controlling the heater of the humidifier by digital control. When the device is powered by the mains power supply, the controller is configured to control the heater according to a second control scheme, the second control scheme including controlling the heater of the duct and the heater of the humidifier by digital control.

[0009] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a humidifier configured to be pneumatically connected to a flow generator and to humidify a gas flow generated by the flow generator, wherein the humidifier includes a heater, wherein the device is configured to be connected to a conduit for delivering the gas flow, a battery, wherein the device is configured to be powered by the battery or mains power, and a controller configured to control the heater of the humidifier according to at least a first control scheme and a second control scheme, wherein when the device is powered by the battery, the controller is configured to control the heater of the humidifier according to the first control scheme, the first control scheme including providing a high-frequency pulse width modulation signal to the heater of the humidifier, and wherein when the device is powered by the mains power, the controller is configured to control the heater of the humidifier according to the second control scheme, the second control scheme including providing a low-frequency pulse width modulation signal to the heater of the humidifier, and wherein the frequency of the high-frequency pulse width modulation signal is greater than the frequency of the low-frequency pulse width modulation signal.

[0010] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a humidifier configured to be pneumatically connected to a flow generator and to humidify a gas flow generated by the flow generator, wherein the device is configured to be connected to a conduit for delivering the gas flow, wherein the conduit includes a heater configured to heat the gas flow within the conduit; a battery, wherein the device is configured to be powered by the battery or by mains power; and a controller configured to control the heater of the conduit according to at least a first control scheme and a second control scheme, wherein when the device is powered by the battery, the controller is configured to control the heater of the conduit according to the first control scheme, the first control scheme including controlling the heater of the conduit by analog control, and wherein when the device is powered by mains power, the controller is configured to control the heater of the conduit according to the second control scheme, the second control scheme including controlling the heater of the conduit by digital control (which may include pulse width modulation if necessary).

[0011] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a humidifier configured to be pneumatically connected to a flow generator and to humidify a gas flow generated by the flow generator, wherein the humidifier includes a heater; the device is configured to be connected to a conduit for conveying the gas flow, wherein the conduit includes a heater configured to heat the gas flow within the conduit; a battery, wherein the device is configured to be powered by the battery or mains power; and a controller configured to control the heater of the conduit according to at least a first control scheme and a second control scheme. When the device is powered by the battery, the controller is configured to control the heater of the duct and the heater of the humidifier according to a first control scheme, the first control scheme including controlling the heater of the duct by analog control and providing a high-frequency pulse width modulation signal to the heater of the humidifier, and wherein when the device is powered by AC power, the controller is configured to control the heater according to a second control scheme, the second control scheme including controlling the heater of the duct by digital control (if necessary, by providing a pulse width modulation signal) and providing a low-frequency pulse width modulation signal to the heater of the humidifier, and wherein the frequency of the high-frequency pulse width modulation signal is greater than the frequency of the low-frequency pulse width modulation signal.

[0012] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a humidifier configured to be pneumatically connected to a flow generator and to humidify a gas flow generated by the flow generator; at least one heater, wherein the device is configured to be connected to a conduit for delivering the gas flow; a battery, wherein the device is configured to be powered by the battery or by mains power; and a controller configured to control the at least one heater according to at least a first control scheme and a second control scheme, wherein when the device is powered by the battery, the controller is configured to control the heater according to the first control scheme, the first control scheme including controlling the heater by analog control, and wherein when the device is powered by mains power, the controller is configured to control the heater according to the second control scheme, the second control scheme including controlling the heater by digital control (which may include pulse width modulation if necessary).

[0013] The at least one heater may include the heater of the conduit, the heater of the conduit being configured to heat the gas flow within the conduit.

[0014] The at least one heater may include the heater of the humidifier.

[0015] Controlling the at least one heater by digital control may include providing a pulse width modulation signal to the heater of the conduit.

[0016] The frequency of the pulse width modulation signal can be less than about 20 Hz, or about 20 Hz to about 1 kHz.

[0017] The controller can control the duty cycle of the pulse width modulation signal provided to the at least one heater by means of the second control scheme according to the humidification control algorithm.

[0018] The controller can control the duty cycle of the pulse width modulation signal supplied to the at least one heater based on one or more treatment parameters (which, if necessary, are the treatment temperatures of the gas provided to the user) using the second control scheme.

[0019] The controller can control the duty cycle of the pulse width modulation signal supplied to the at least one heater by means of the second control scheme based on the desired end temperature of the gas flow in the conduit.

[0020] The duty cycle of the pulse width modulation signal can be based on the desired power of the at least one heater.

[0021] The controller can be configured to measure the power supplied to the at least one heater and control the duty cycle of the pulse width modulation signal based on the measured power supplied to the at least one heater and the desired power of the at least one heater.

[0022] The first control scheme may include providing a low-frequency pulse width modulation signal to the at least one heater, and the second control scheme includes providing a high-frequency pulse width modulation signal to the at least one heater, wherein the frequency of the high-frequency pulse width modulation signal is greater than the frequency of the low-frequency pulse width modulation signal.

[0023] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a humidifier configured to be pneumatically connected to a flow generator and to humidify a gas flow generated by the flow generator, wherein the humidifier includes a heater; the device is configured to be connected to a conduit for conveying the gas flow, wherein the conduit includes a heater configured to heat the gas flow within the conduit; a battery, wherein the device is configured to be powered by the battery or mains power; and a controller configured to control the heater of the conduit and the heater of the humidifier according to at least a first control scheme and a second control scheme. When the device is powered by the battery, the controller is configured to control the heater of the duct and the heater of the humidifier according to a first control scheme, the first control scheme including controlling the heater of the duct by analog control and controlling the heater of the humidifier by digital control. When the device is powered by the mains power supply, the controller is configured to control the heater according to a second control scheme, the second control scheme including controlling the heater of the duct and the heater of the humidifier by digital control.

[0024] The frequency of the high-frequency pulse width modulation signal can be greater than the frequency of the low-frequency pulse width modulation signal.

[0025] The device may include a flow generator configured to generate the gas flow.

[0026] The device can be configured to detect whether the device operates on a battery or AC power source.

[0027] The device can be configured to operate on battery power when no AC power is detected.

[0028] The device can be configured to operate on battery power based on input from the user (via a user interface if necessary).

[0029] The device may include a battery charger, and wherein the device is configured to charge the battery when the device is powered by an AC power source (and, if necessary, when the AC power source voltage is above a threshold) and the battery is not fully charged (and, if necessary, when the battery charge is below a charge threshold).

[0030] The device may include an AC power conversion circuit configured to convert the AC power supply to a low DC voltage (approximately 3 volts DC to approximately 60 volts DC, as required).

[0031] The device may include a battery conversion circuit configured to convert the battery power to a low DC voltage (approximately 3 volts DC to approximately 60 volts DC, as needed).

[0032] The battery may be located in the device (and, if necessary, in the housing of the device).

[0033] The battery includes at least one battery.

[0034] The battery can be configured to be connected to and disconnected from the device (and, if necessary, from the housing of the device).

[0035] The battery cannot be connected to or disconnected from the device (and, if necessary, from the device housing).

[0036] The battery may be part of a battery module.

[0037] The battery module may include battery detection pins and / or battery detection ports.

[0038] The battery detection pin may include a pull-up or pull-down resistor connected to the battery detection pin.

[0039] The battery module may include one or more memory elements configured to store one or more battery parameters.

[0040] These battery parameters may include: a) battery lifespan b) battery cell status c) battery charge status d) number of charge and discharge cycles e) battery capacity f) battery voltage g) battery current output h) battery temperature i) any combination of a) to h).

[0041] The device may include one or more power rail capacitors.

[0042] The power supply rail capacitors may be configured to be located at: a) the output terminal of the battery b) the output terminal of the mains power supply c) the output terminal of the one or more batteries or mains power conversion circuit d) any combination of a) to c).

[0043] The frequency of the low-frequency pulse width modulation signal of the first control scheme is less than about 20 Hz, or about 20 Hz to about 1 kHz.

[0044] The frequency of the high-frequency pulse width modulation signal of the second control scheme is about 25 kHz, or about 1 kHz to about 50 kHz.

[0045] The frequency of a high-frequency pulse width modulation signal can be about 1250 times that of a low-frequency pulse width modulation signal.

[0046] The frequency of the high-frequency pulse width modulation signal can be a certain order of magnitude larger than the frequency of the low-frequency pulse width modulation signal.

[0047] The frequency of the high-frequency pulse width modulation signal can be about 50 times to about 2000 times the frequency of the low-frequency pulse width modulation signal.

[0048] The controller can control the duty cycle of the low-frequency pulse width modulation signal and / or the high-frequency pulse width modulation signal according to the humidification control algorithm.

[0049] The controller can control the duty cycle of the low-frequency pulse width modulation signal and / or the high-frequency pulse width modulation signal based on one or more treatment parameters (which may be treatment humidity level, and may be relative humidity or absolute humidity or dew point, depending on the need).

[0050] The controller can control the duty cycle of the low-frequency pulse width modulation signal and / or the high-frequency pulse width modulation signal based on the desired power of the heater of the humidifier.

[0051] The controller can be configured to measure the power supplied to the heater of the humidifier and control the duty cycle of the low-frequency pulse width modulation signal and / or the high-frequency pulse width modulation signal based on the measured power supplied to the heater of the humidifier and the desired power of the heater of the humidifier.

[0052] The controller can control the duty cycle of the low-frequency pulse width modulation signal and / or the high-frequency pulse width modulation signal based on the desired temperature of the heater of the humidifier.

[0053] The desired power requirement and / or desired temperature may be based on one or more treatment parameters of the device.

[0054] The heater for controlling the conduit by digital control may include providing a pulse width modulation signal to the heater of the conduit.

[0055] The frequency of the pulse width modulation signal can be less than about 20 Hz, or about 20 Hz to about 1 kHz.

[0056] The controller can control the duty cycle of the pulse width modulation signal supplied to the heater of the duct by means of the second control scheme according to the humidification control algorithm.

[0057] The controller can control the duty cycle of the pulse width modulation signal supplied to the heater of the catheter based on one or more treatment parameters (which, if necessary, are the treatment temperatures of the gas provided to the user) using the second control scheme.

[0058] The controller can control the duty cycle of the pulse width modulation signal supplied to the heater of the conduit based on the desired conduit end temperature of the gas flow in the conduit using the second control scheme.

[0059] The duty cycle of the pulse width modulation signal can be based on the expected power of the heater of the conduit.

[0060] The controller can be configured to measure the power supplied to the heater of the conduit and control the duty cycle of the pulse width modulation signal based on the measured power supplied to the heater of the conduit and the desired power of the heater of the conduit.

[0061] Controlling the heater of the duct by analog control includes providing analog control signals to the heater of the duct and / or the heater of the humidifier.

[0062] The heater of the conduit controlled by analog control may include providing a voltage signal to the heater of the conduit.

[0063] The analog control signal can be a voltage signal or a current signal.

[0064] The analog control signal may be generated by voltage modulation, current modulation or resistance modulation.

[0065] The controller can control the analog control signal supplied to the heater of the catheter based on one or more treatment parameters (which, if necessary, are the treatment temperature of the gas provided to the user).

[0066] The controller can control the voltage signal supplied to the heater of the catheter based on one or more treatment parameters (which, if necessary, are the treatment temperature of the gas supplied to the user).

[0067] The analog control signal can be controlled based on the desired power of the heater of the conduit.

[0068] The voltage signal can be controlled based on the desired power of the heater of the conduit.

[0069] The controller can be configured to measure the power supplied to the heater of the conduit, and the analog control signal is controlled based on the measured power supplied to the heater conduit and the desired power of the heater of the conduit.

[0070] The controller can be configured to measure the power supplied to the heater of the conduit, and the voltage signal is controlled based on the measured power supplied to the heater conduit and the desired power of the heater of the conduit.

[0071] The voltage signal can be quadratically related to the input power (e.g., the measured power supplied to the heater conduit).

[0072] The analog control signal can be controlled based on the desired end temperature of the gas flow in the conduit.

[0073] The voltage signal can be controlled based on the desired end temperature of the gas flow in the conduit.

[0074] The device may include an analog control circuit system.

[0075] The analog control signal can be controlled by the analog control circuit system.

[0076] The voltage signal can be controlled by the analog control circuit system.

[0077] The analog signal can be controlled by one or more voltage converters of the analog control circuit system.

[0078] The one or more voltage converters may include: a) a buck converter b) a DC-DC converter c) a boost converter d) a boost converter e) a half-bridge converter f) a flyback converter g) a push-pull converter h) a switching converter i) a switching regulator j) a linear regulator k) a linear converter l) a buck converter m) a transformer n) any combination of a) to m).

[0079] The voltage signal can be controlled by one or more voltage converters of the analog control circuit system.

[0080] The one or more voltage converters may include: a) a buck converter b) a DC-DC converter c) a switching regulator d) a linear regulator e) a buck converter f) a transformer g) any combination of a) to f).

[0081] The analog control circuit system can be disabled when the device is controlling the heater of the conduit according to the second control scheme.

[0082] The device may include a digital control circuit system configured to generate a pulse width modulation signal for a heater for the conduit, and / or the high-frequency pulse width modulation signal and / or the low-frequency pulse width modulation signal.

[0083] The digital control circuit system may include one or more switching circuits.

[0084] The digital control circuit system may include one or more pulse width modulation drivers.

[0085] The digital control circuit system may include a heater of a humidifier pulse width modulation driver, the humidifier pulse width modulation driver being configured to generate the high-frequency pulse width modulation signal and the low-frequency pulse width modulation signal.

[0086] The digital control circuit system may include a heater of a conduit pulse width modulation driver, the conduit pulse width modulation driver being configured to generate the pulse width modulation signal.

[0087] When the device is controlling the heater of the conduit according to the first control scheme, the heater of the conduit pulse width modulation driver can be disabled.

[0088] The heater of the humidifier may include a heating plate, and the heating plate is configured to heat the fluid in the humidification chamber to humidify the gas flow.

[0089] The heater of the humidifier may include a conductive heating element.

[0090] The heater of the conduit may include a heating wire.

[0091] The heater of the conduit may include a conductive heating element.

[0092] The heating wire may be: a) in the lumen of the conduit, b) within the wall of the conduit, c) embedded in the wall of the conduit, d) embedded in the beaded edge forming the breathing conduit, the beaded edge being configured as needed to provide structural support to the conduit, e) located on the outer surface of the conduit, f) any combination of a) to e).

[0093] The at least one heater may be primarily a resistive load.

[0094] The device may include a housing, and the flow generator and / or humidifier are located in the housing (or a single housing if necessary).

[0095] The device may include a gas inlet and a gas outlet, wherein the conduit is configured to be connected to the gas outlet.

[0096] When the device is initially powered by the battery, the controller can be configured to: disable the heater of the humidifier and / or the heater of the duct, and subsequently control the heater of the humidifier and / or the heater of the duct to a desired value or a certain percentage of the desired value.

[0097] Disabling the humidifier heater and / or the heater of the duct may include providing a disable control circuit system and / or providing a shutdown control signal.

[0098] The device can be configured to control the heater of the humidifier and / or the heater of the duct to a desired value or a certain percentage of the desired value after a predetermined amount of time.

[0099] The controller can be configured to control the heater of the humidifier and / or the heater of the duct at a predetermined rate or below the predetermined rate to the desired value or a certain percentage of the desired value.

[0100] When the device is initially powered by the battery, the controller can be configured to deliver power to the flow generator in priority over the heater of the humidifier and / or the heater of the duct.

[0101] The battery may have a power budget indicating the power that can be supplied by the battery, wherein the power budget is allocated to the flow generator in priority over the heater of the humidifier and / or the heater of the duct.

[0102] The power of the heater delivered to the humidifier and / or the heater of the duct can be based on the remaining power of the power budget, wherein the remaining power of the power budget is the power budget minus the power required to power the flow generator.

[0103] If the remaining power is greater than the combined expected power of the heater of the humidifier and / or the heater of the duct, the controller may be configured to reduce the power supplied to the heater of the humidifier and / or the heater of the duct (as needed, to the remaining power budget).

[0104] When the device is initially powered by the battery, the controller can be configured to disable the humidifier and / or the heater of the duct when the battery charge reaches a threshold.

[0105] The threshold may be approximately 5% to approximately 40%, or approximately 10% to approximately 30%, or approximately 20%.

[0106] A respiratory assist device includes: a humidifier configured to be pneumatically connected to a flow generator and to humidify a gas flow generated by the flow generator, wherein the humidifier includes a heater; a battery, wherein the device is configured to be powered by the battery or by mains power; and a controller configured to control the heater of the humidifier according to at least a first control scheme and a second control scheme, wherein when the device is powered by the battery, the controller is configured to control the heater of the humidifier according to the first control scheme, the first control scheme including controlling the heater of the humidifier by analog control, and wherein when the device is powered by mains power, the controller is configured to control the heater of the humidifier according to the second control scheme, the second control scheme including controlling the heater of the humidifier by digital control (the digital control may include pulse width modulation if necessary).

[0107] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a humidifier configured to be pneumatically connected to a flow generator and to humidify a gas flow generated by the flow generator, wherein the device is configured to be connected to a conduit for conveying the gas flow, wherein the conduit includes a heater configured to heat the gas flow within the conduit; a battery, wherein the device is configured to be powered by the battery or mains power; and a controller configured to control the heater of the humidifier according to at least a first control scheme and a second control scheme. When the device is powered by the battery, the controller is configured to control the heater of the conduit according to the first control scheme, the first control scheme including providing a high-frequency pulse width modulation signal to the heater of the conduit, and wherein when the device is powered by the mains power supply, the controller is configured to control the heater of the conduit according to the second control scheme, the second control scheme including providing a low-frequency pulse width modulation signal to the heater of the conduit, and wherein the frequency of the high-frequency pulse width modulation signal is greater than the frequency of the low-frequency pulse width modulation signal.

[0108] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a humidifier configured to be pneumatically connected to a flow generator and to humidify a gas flow generated by the flow generator, wherein the humidifier includes a heater; wherein the device is configured to be connected to a conduit for delivering the gas flow, wherein the conduit includes a heater configured to heat the gas flow within the conduit; a battery, wherein the device is configured to be powered by the battery or by mains power; and a controller, wherein when the device is initially powered by the battery, the controller is configured to: disable the heater of the humidifier and / or the heater of the conduit, and subsequently control the heater of the humidifier and / or the heater of the conduit to a desired value or a certain percentage of a desired value.

[0109] In one aspect of this disclosure, a respiratory assist device is provided, comprising: a humidifier configured to be pneumatically connected to a flow generator and to humidify a gas flow generated by the flow generator, wherein the humidifier includes a heater; wherein the device is configured to be connected to a conduit for conveying the gas flow, wherein the conduit includes a heater for the conduit and the heater is configured to heat the gas flow within the conduit; a battery, wherein the device is configured to be powered by the battery or by mains power; and a controller, wherein when the device is initially powered by the battery, the controller is configured to deliver power to the flow generator in priority to the heater of the humidifier and / or the heater of the conduit.

[0110] In one aspect of this disclosure, a humidifier is provided, configured to humidify a gas stream, the humidifier comprising: a heater, a battery, wherein the humidifier is configured to be powered by the battery or mains power, and a controller configured to control the heater according to at least a first control scheme and a second control scheme, wherein when the humidifier is powered by the battery, the controller is configured to control the heater of the humidifier according to the first control scheme, the first control scheme including providing a high-frequency pulse width modulation signal to the heater of the humidifier, and wherein when the device is powered by the mains power, the controller is configured to control the heater according to the second control scheme, the second control scheme including providing a low-frequency pulse width modulation signal to the heater, and wherein the frequency of the high-frequency pulse width modulation signal is greater than the frequency of the low-frequency pulse width modulation signal.

[0111] In one aspect of this disclosure, a humidifier is provided, configured to humidify a gas stream, the humidifier comprising: at least one heater, wherein the humidifier is configured to be connected to a conduit for delivering the gas stream; a battery, wherein the device is configured to be powered by the battery or by mains power; and a controller configured to control the at least one heater according to at least a first control scheme and a second control scheme, wherein when the humidifier is powered by the battery, the controller is configured to control the at least one heater according to the first control scheme, the first control scheme including controlling the at least one heater by analog control, and wherein when the humidifier is powered by mains power, the controller is configured to control the at least one heater according to the second control scheme, the second control scheme including controlling the at least one heater by digital control (which may include pulse width modulation if necessary).

[0112] The at least one heater may include the heater of the conduit, the heater of the conduit being configured to heat the gas flow within the conduit.

[0113] The at least one heater may include the heater of the humidifier.

[0114] In another aspect, a surgical humidifier is provided, which may have any of the features described with respect to respiratory assist devices in any of the foregoing aspects.

[0115] It should be understood that any of the foregoing statements may be combined with any one or more other statements.

[0116] It is intended that references to the range of numbers disclosed herein (e.g., 1 to 10) also include references to all rational numbers within that range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10) as well as 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 all ranges explicitly disclosed herein are explicitly disclosed. These are merely examples of specific intentions, and all possible combinations of numerical values ​​between the enumerated minimum and maximum values ​​should be considered as being explicitly stated in a similar manner in this application.

[0117] It should be understood that alternative implementations or configurations may include any or all combinations of two or more of the parts, elements or features shown, described or mentioned in this specification.

[0118] Some embodiments of this disclosure may also be broadly understood to refer to or be included in the description of this application, individually or collectively with respect to or specified parts, elements and features, and any or all combinations of any two or more of the said parts, elements or features, and when a specific integer having a known equivalent in the field to which this disclosure pertains is referred to herein, such known equivalents are also considered to be incorporated herein as if individually listed.

[0119] The term "comprising" as used in this specification means "including". When interpreting each statement of the term "comprising" in this specification, features other than the one or those features following that term may also exist. Related terms such as "comprise" and "comprises" will be interpreted in the same manner.

[0120] When used in the context of a controller, the term request can refer to the controller sending a signal to a component to instruct that component to perform one or more actions.

[0121] As used herein, the word "(multiple)" preceding a noun refers to the plural and / or singular form of that noun.

[0122] As used herein, the word “and / or” means “and” or “or” or both.

[0123] This disclosure discloses the foregoing content and also envisions various structures, of which only examples are given below.

[0124] It should be understood that when a list is made, this disclosure includes any combination of items in the list.

Implementation Method

[0136] The respiratory assist device 10 provides treatment to the user, such as any combination of the following: high-flow nasal airway (NHF) treatment, continuous positive airway pressure (CPAP) treatment, non-invasive ventilation (NIV) and bubble continuous positive airway pressure (BCPAP) treatment.

[0137] In some configurations, device 10 can be used during pre-oxygenation or during anesthesia. In some configurations, device 10 can be used during any other medical procedure in which the patient experiences apnea or other respiratory dysfunction that may be impaired or is at risk of impairment.

[0138] During surgery, device 10 can operate from multiple power sources. In some cases, device 10 can be powered by mains power (e.g., from the power grid). In other cases, device 10 can be powered by batteries.

[0139] The electrical characteristics of an AC power source may differ significantly from those of a battery. For example, an AC power source may operate at AC voltage (i.e., from 100 volts to approximately 240 volts) and provide alternating current, while a battery may operate at a voltage less than 100 volts and provide direct current. Furthermore, the rated power delivery of a battery may be significantly lower than that of an AC power source.

[0140] If the device draws more power than the battery is rated to deliver, the battery may overheat or be damaged.

[0141] Furthermore, if the power drawn by the device momentarily exceeds or continuously exceeds the battery's rated power, the battery's voltage supply may decrease—this could damage the device or render measurements or calculations performed by the device unreliable. In some cases, the voltage may drop below the threshold required for the device to operate, and the device may lose power.

[0142] Further consideration should be given to the electromagnetic interference generated by the equipment. The generation of electromagnetic interference may be the result of high-frequency switching of components in the equipment. Since the heater of the conduit may extend along the length of the conduit and thus increase the electromagnetic interference (e.g., the strength of the interfering electromagnetic field) by acting partly like an antenna, the generation of electromagnetic interference may be more severe in the heater of the conduit (e.g., if the heater of the conduit is a wire extending along the length of the conduit).

[0143] One mechanism for increased electromagnetic interference (EMI) due to the heater of the conduit is that the intensity of EMI increases when the wavelength of the switching signal is close to a multiple or integer multiple of the length of the heater of the conduit. This effect may be more pronounced due to high-frequency switching of the heater of the conduit when the wavelength of the switching signal is shorter and close to a multiple of the length of the heater, thus causing an increase in EMI (depending on the length of the heater of the conduit). When the wavelength is relatively long and relatively far from a multiple of the length of the heater of the conduit, this is not a problem for the relatively low-frequency switching of the heater of the conduit.

[0144] Electromagnetic interference can be at least partially mitigated by providing a shield to the heater of the conduit; however, this increases the cost and complexity of the conduit.

[0145] Electromagnetic interference may interfere with the operation of device 10 (e.g., internal controller, integrated circuit or sensor) and other devices in the vicinity of the device.

[0146] This disclosure provides control over the heater of the device based on the type of power supply (and associated electrical characteristics) – for example, by reducing the peak power drawn, while managing electromagnetic interference generated by the device 10 and providing treatment to the user.

[0147] As described in more detail below, device 10 may include a heater (e.g., a heating plate) for a humidifier and a heater (e.g., a heating wire) for a duct.

[0148] The heater may include one or more heating elements.

[0149] It should be understood that other types of heaters known in the art may be used.

[0150] When the device 10 is powered by mains power (or, for example, another non-peak power limited power source described in more detail below), the device 10 can control the heater of the humidifier and the heater of the duct by means of digital control (e.g., by means of pulse width modulation).

[0151] Pulse width modulation control can be performed by providing a pulse width modulation signal (as described in more detail below) to the heater of the humidifier and / or the heater of the duct.

[0152] The term pulse width modulation signal can be used interchangeably with the term pulse width modulation signal.

[0153] A pulse width modulation signal may be provided to the heater of the humidifier and / or the heater of the duct to supply power to the heater of the humidifier and / or the heater of the duct.

[0154] When the device 10 is powered by mains power, the frequency of the pulse width modulation signal can be provided at a relatively low frequency to reduce electromagnetic interference generated by the device (e.g., as a low-frequency pulse width modulation signal).

[0155] However, when the device 10 is powered by a battery (or, for example, another peak power-limited power source described in more detail below), using the same digital control (e.g., pulse width modulation) for the heater of the humidifier and the heater of the duct may cause the battery’s rated power (e.g., power delivery or power source rating) to be exceeded during the on-time portion of the pulse width modulation signal, as the device attempts to draw more power than the battery is capable of providing.

[0156] Therefore, when the device 10 is powered by a battery (or, for example, another peak power-limited power source described in more detail below), the frequency of the pulse width modulation signal can be increased (e.g., as a high-frequency pulse width modulation signal). However, this may be counterintuitive, as it may increase electromagnetic interference generated by the device and may reduce the efficiency of the switching circuitry in the digital control circuitry system that generates the pulse width modulation signal (e.g., by increasing the switching losses of MOSFETs or other types of transistors in the switching circuitry).

[0157] The combined use of high-frequency pulse-width modulation (PWM) signals with capacitive energy storage (e.g., power rail capacitors as described below) allows the peak power requirements of a device to be met without exceeding the battery's rated power. For example, the battery may only need to provide a lower peak power (because the discharge capacitive energy storage will provide additional power during the conduction portion of the PWM signal). This approach can be challenging with low-frequency PWM signals, which would require significantly larger capacitive energy storage because the conduction portion of the PWM signal would be relatively longer and therefore a much larger amount of energy would need to be supplied to the device during the conduction portion compared to the energy required for high-frequency PWM signals (i.e., as additional power from the capacitive energy storage). The larger capacitive energy storage required to provide the additional power can lead to increased device costs and increased space requirements due to the larger capacitive energy storage.

[0158] Using a low-frequency pulse width modulation signal when operating from a battery may increase the heat generated by the battery, which may lead to accelerated battery degradation, such as a shortened battery life.

[0159] The terms “low-frequency pulse width modulation signal” and “high-frequency pulse width modulation signal” are relative terms and can be replaced by the terms “first pulse width modulation signal” and “second pulse width modulation signal” (respectively).

[0160] When the device 10 is powered by a battery, the device (e.g., via controller 13) can control the heater of the humidifier by providing a high-frequency pulse width modulation signal. This reduces the peak power drawn from the battery while still reducing switching losses and keeping the generation of electromagnetic interference below an acceptable level.

[0161] If a high-frequency pulse-width modulation (PWM) signal is applied to the heater of the conduit, the resulting electromagnetic interference may exceed acceptable levels. Furthermore, the PWM signal may interfere with safety mechanisms designed to detect energy transients or short circuits in the conduit heater. For example, if the safety mechanism is configured to monitor the rate of voltage change, the PWM signal may cause false triggering. Alternatively, if the rate of voltage change threshold of the safety mechanism is increased, the safety mechanism may become less effective and the safety risk to the user may increase.

[0162] Battery operation of device 10 allows patients in a hospital environment to be transported between locations within the hospital (e.g., to a rehabilitation ward) while still receiving treatment (and humidified gas). Therefore, treatment can be provided continuously before transport (when operating on, for example, mains power), during patient transport (e.g., when operating on batteries), and after transport (e.g., when operating on mains power).

[0163] The battery operation of the device 10 allows patients in a home environment to move and perform activities or tasks without being restricted to a location with mains power, while still providing treatment.

[0164] This disclosure allows the device to operate on battery power for longer periods of time because the peak power drawn is reduced by r, which can extend battery life to a time sufficient for operations such as transporting patients in a hospital setting or allowing patients to perform activities or tasks that would normally be impossible when limited to mains power. Battery life may be, for example, about 45 minutes, and the device can provide treatment (at or near the desired treatment parameters) during this time.

[0165] Providing treatment when powered by a battery can offer benefits in terms of comfort and compliance. This disclosure can provide a control scheme to allow for the delivery of humidity while also allowing for portability.

[0166] Providing therapeutic humidity to users can increase patient comfort and adherence to treatment. The provision of humidity also provides the additional benefit of improved mucus transport, which is useful for patients with obstructive pulmonary disease, improving comfort and thus improving adherence to / acceptance of such treatments.

[0167] Reducing peak power draw during battery operation also allows for the use of smaller batteries while still delivering treatment (e.g., at or near the desired treatment parameters). Using a relatively small battery power source allows the device to remain compact, which may mean that the weight and size of the device do not increase due to the inclusion of a relatively large battery. Therefore, this disclosure can lead to a more portable and easier-to-use device. The portability of the device can increase its availability in home care settings, as the device can be moved more easily around the user's house. In hospital settings, portability allows the treatment device to be moved with the patient around the hospital, so the patient can continue receiving treatment while being transported.

[0168] In the context of surgical humidifiers (as described in more detail below), this disclosure provides a system in which treatment can still be provided (e.g., at desired or near-desired treatment parameters) in the event of loss of mains power (e.g., power outage), during transport, or in areas where surgery is required without available mains power. The above disclosure also applies to surgical humidifiers.

[0169] When the device 10 is powered by a battery, the device can control the heater of the duct and / or the heater of the humidifier by analog control (e.g., by providing voltage (i.e., analog modulated or regulated voltage) through the heater of the duct and / or the heater of the humidifier).

[0170] Analog control can be implemented by providing analog control signals to the heater of the duct and / or the heater of the humidifier (as described in more detail below).

[0171] In some configurations, the analog control circuitry system configured to generate analog control signals (e.g., voltages) supplied by the heater across the conduit may generate electromagnetic interference (e.g., by the antenna effect as described above and by switching control signals), but much less than in the case of using high-frequency pulse width modulation.

[0172] Similarly, regarding the heater of the humidifier, an analog control circuit system configured to generate an analog control signal (e.g., voltage) provided by the heater across the humidifier may generate electromagnetic interference (e.g., by switching digital control signals), but much less than in the case of using high-frequency pulse width modulation.

[0173] Analog control circuit systems may be less efficient than digital control due to additional losses introduced, for example, by certain components (e.g., high-frequency switching components) in some circuit topologies used to generate analog control signals.

[0174] When the device 10 is powered by a battery, the combination of digital control of the heater of the humidifier (with a high-frequency pulse width modulation signal) and analog control of the heater of the duct can ensure that the peak power drawn from the battery does not exceed the battery rating and that the generation of electromagnetic interference is kept below an acceptable level.

[0175] In some configurations, when the device 10 is powered by a battery, the combination of analog control of the heater of the duct and analog control of the heater of the humidifier can ensure that the peak power drawn from the battery does not exceed the battery rating and that the generation of electromagnetic interference is kept below an acceptable level.

[0176] Figure 1 illustrates a breathing assist device 10. The breathing assist device 10 may include a housing 100 (e.g., as a single housing) containing one or more of the following: a flow generator 11 (e.g., a hair dryer) arranged in a motor / impeller configuration in some configurations, a humidifier 12 pneumatically connected to the flow generator 11, a controller 13, and a user interface 14 (including, for example, a display and input devices such as buttons, a touch screen, etc.).

[0177] In Figure 2, device 10 shows a housing 100 that includes a flow generator 11 and a humidifier 12 pneumatically connected to the flow generator 11. As shown in Figure 2, the humidifier 12 and the flow generator 11 are integrated into a common housing. This provides a compact device that can be easily moved or carried to provide mobility. Furthermore, the combination of the flow generator 11 and the humidifier 12 in the same housing allows for a simpler setup (i.e., the chamber 300 is positioned within the housing).

[0178] In some configurations, the respiratory support device 10 may not include a flow generator 11. In this case, the device 10 does not generate a gas flow but is configured to connect to an external flow generator and to humidify the gas flow from the external flow generator. For example, the respiratory support device 10 may be used as a stand-alone humidifier to humidify the gas flowing through it. The flow generator may be a wall gas supply (e.g., regulated via a flow meter or rotameter) or a ventilator or other stand-alone flow generator that may be configured to provide one of the treatments described elsewhere in the specification (e.g., NIV, NHF, CPAP, BCPAP, invasive ventilation, etc.). The humidifier may include a battery connected to it to provide power when mains power is unavailable (as a battery power source). In some configurations, the battery may be removably connected to the device and is rechargeable. The humidifier is pneumatically connected to the flow generator via a catheter, and a separate catheter is connected to the humidifier to deliver humidified gas from the humidifier to the patient.

[0179] Figures 2A and 2B illustrate an example of device 10 as a humidifier (i.e., without a flow generator). The device includes a connector that pneumatically connects conduit 16 (as described in more detail above) to the outlet of the humidification chamber 31 (as the gas outlet of the device). Conduit 16 may be an inspiratory branch of the patient circuit, i.e., configured to deliver humidified gas to the user as via a patient interface (not shown). Conduit 16 may have a conduit heater 16a (e.g., as described elsewhere in the specification).

[0180] The inlet 8 of the humidification chamber 300 is configured to be fluidly connected to a flow generator located remotely from the device 10 (e.g., via a conduit connected to the inlet 8 as shown in FIG2A).

[0181] As shown in Figures 2A and 2B, device 10 further includes a panel 9, which can be used to mount a user display and / or controls. For example, various dials, switches, and other input devices can be used to control the operation of the device. Alternatively or alternatively, a touch screen display can be used. The user display can show system parameters, warnings in any error or malfunction condition, or prompts requiring user action, etc. When using a touch screen display, the display can be used to present information to the user at least partially and to receive input from the user (e.g., as described elsewhere in the specification). The humidifier device shown in Figures 2A and 2B may include multiple sensors. For example, humidifier 10 may include a flow sensor, one or more temperature sensors, one or more pressure sensors, and one or more humidity sensors. In one example configuration, the humidifier includes at least a temperature sensor located in or near the inlet and a temperature sensor located in or near the outlet of chamber 300. If necessary, the humidifier may include a flow sensor located in or near the outlet of chamber 300. Additionally, another flow sensor may be located in or near the inlet 8. Depending on the requirements, the humidifier may include a single flow sensor located at the inlet or outlet. The humidifier may additionally include one or more humidity sensors, which may be arranged within or near the inlet or outlet, or in both the inlet and outlet. Further, an additional ambient temperature sensor may be included. The humidifier may also include additional sensors associated with the heater, such as a temperature sensor associated with the heater.

[0182] In some configurations, the device 10 shown in Figures 2A and 2B may include a battery (discussed in more detail below).

[0183] A battery can be a battery power source. It should be understood that, where the context permits, the terms battery and battery power source can be used interchangeably.

[0184] It should also be understood that the battery may be located outside the device (e.g., located at a distance but electrically connected to the device).

[0185] Device 10 may be, for example, the device described in WO 2015 / 093989 and WO 2015 / 038014, which are incorporated herein by reference in their entirety.

[0186] The humidifier 12 can humidify the gas flow and / or heat the gas flow to an appropriate level. The controller 13 can be configured to control the humidifier 12 (e.g., by controlling at least the humidifier heater).

[0187] The humidifier 12 may include a humidification chamber. The humidification chamber may be configured to be removed from the humidifier (e.g., for replacement, cleaning, and / or refilling). Alternatively, the humidification chamber may be non-removable from the humidifier.

[0188] The humidification chamber may include an automatic filling mechanism comprising at least a valve and a float connected to the valve. The humidification chamber may be connected to a water reservoir of the water bag for automatic filling during use. Alternatively, the humidification chamber may be manually refilled.

[0189] The humidifier 12 may include a humidifier heater 310, for example, as a heating plate (see Figure 2). The humidifier heater provides heat to the humidification chamber 300. The liquid in the humidification chamber may be water or another liquid, and / or may include a mixture of one or more liquids (e.g., a mixture of water and a drug).

[0190] The heater 310 of the humidifier 12 may be a conductive heating element.

[0191] A humidifier can also be a surgical humidifier, which humidifies a gas (such as carbon dioxide) for use in surgery, such as laparoscopic surgery and open surgery.

[0192] The surgical humidifier may have any combination of the features of the humidifier disclosed with respect to the humidifiers of Figures 2A and 2B.

[0193] It should be understood that this disclosure can be applied to surgical humidifiers (or other humidifiers), and the following disclosure regarding respiratory assist devices can be applied to surgical humidifiers.

[0194] The controller 13 may be configured or programmed to control the operation of the respiratory assist device 10. For example, the controller 13 may control components of the respiratory assist device 10, including but not limited to: operating the flow generator 11 to generate gas flows (flows of individual gases) for delivery to the patient; operating the humidifier 12 (if present) to humidify and / or heat the generated gas flows; controlling the oxygen flow into the flow generator blower; receiving user input from the user interface 14 to reconfigure and / or perform user-defined operations on the respiratory assist device 10; and outputting information to the user (e.g., on a display).

[0195] Controller 13 may include one or more sub-controllers. Each sub-controller may be configured to control one or more components of the device (e.g., a flow generator sub-controller, and / or a humidifier sub-controller and / or a humidifier or duct heater sub-controller). Controller 13 may include a master controller configured to communicate with the sub-controllers and transmit commands to them.

[0196] The controller 13 may include one or more computer processors and associated non-transitory memory or storage medium storing processor-executable instructions or code. When executed by one or more processors, such instructions cause the respiratory therapy device to perform the steps and processes described herein.

[0197] It should be understood that when the specification describes the device 10 taking action, the controller 13 may be controlling one or more components of the device 10 to take action.

[0198] It should be understood that the methods described herein can be executed by a controller (or another processor).

[0199] The term breathing assistance apparatus may be used interchangeably with respiratory assistance apparatus, or respiratory therapy apparatus, or flow therapy apparatus.

[0200] The term breathing assistance system may be used interchangeably with respiratory assistance system, or respiratory therapy system, or flow therapy system.

[0201] The term current flow rate can refer to a flow rate measurement that has been performed so far (e.g., at the current time step). It should be understood that the term current flow rate is not limited to the most recent flow rate determination and may include the most recently made flow rate determination (e.g., based on a previous time step or the most recent flow rate determination), and / or a filtered flow rate determination based on a series of past measurements (which may include signal filtering and / or processing as needed).

[0202] The methods described herein can be embodied as software or software modules as part of control software (e.g., computer-readable instructions) stored in and executed by the controller (and / or associated processor).

[0203] In the case of receiving treatment, the user is a patient; however, in the case of interacting with the device (e.g., interacting with the user interface), the user may be one or more of a patient, a healthcare professional (e.g., a clinician), or any other person interested in using the device.

[0204] As used herein, “gas flow” can refer to any gas flow that can be provided by a breathing aid, such as ambient air flow, including flow of essentially 100% oxygen, flow including some combination of ambient air and oxygen, etc.

[0205] The breathing tube 16 is connected at one end to the gas outlet 21 in the housing 100 of the respiratory assist device 10. The breathing tube 16 is connected at the other end to a patient interface 17, such as an unsealed nasal cannula with a manifold 19 and a nose fork 18. Alternatively or additionally, the breathing tube 16 may be connected to a face mask, nasal mask, nasal pillow mask, endotracheal tube, tracheostomy interface, etc.

[0206] A breathing tube can be installed between the breathing tube 16 and the patient interface 17.

[0207] In some configurations, different types of conduits may be connected to the gas outlet 21, such as a sterilization conduit in sterilization mode. The sterilization mode may be as described in WO 2007 / 069922, which is incorporated herein by reference in its entirety.

[0208] In disinfection mode, the disinfection conduit can be heated to a temperature that can disinfect the gas flow path of the device (e.g., the disinfection conduit and / or one or more bends).

[0209] The gas flow generated by the respiratory assist device 10 can be humidified and delivered to the patient via the breathing tube 16 and the patient interface 17.

[0210] The breathing tube 16 may have a heater 16a to heat the gas flow to the patient. The heater 16a may be controlled by a controller 13. In at least one configuration, the heater 16a is a heating wire. The breathing tube 16 and / or the patient interface 17 may be considered as part of a respiratory support system. The respiratory support system 1 may include a respiratory support device 10, a breathing tube 16, and a patient interface 17.

[0211] The heater 16a of the breathing tube may be located in: a) the lumen of the breathing tube 16, b) within the wall of the breathing tube 16, c) embedded in the wall of the breathing tube 16, d) embedded in the beaded edge forming the breathing tube 16, the beaded edge being configured to provide structural support to the tube 16, e) located on the outer surface of the breathing tube 16, f) any combination of a) to e).

[0212] The heater 16a may extend linearly along the conduit 16 or be spirally wound around the conduit or spirally wound inside the conduit.

[0213] The heater 16a of the breathing tube 16 may be a conductive heating element (e.g., a heating wire).

[0214] Controller 13 can control flow generator 11 to generate a gas flow at a desired flow rate (e.g., therapeutic flow rate). Controller 13 can also control supplemental oxygen inlet to allow delivery of supplemental oxygen.

[0215] The controller 13 can also control the humidifier heater in the humidifier 12 and / or the heater 16a in the breathing tube 16 to heat the gas to the desired temperature to achieve the patient's desired level of treatment and / or comfort.

[0216] The controller 13 may be set with a suitable target temperature for the gas flow or may be able to determine a suitable target temperature for the gas flow. The controller 13 may control the humidifier heater of the humidifier 12 and / or the heater 16a of the breathing duct based on one or more suitable target temperatures of the gas flow.

[0217] The heater 16a of the breathing tube 16 can be controlled by the controller 13 to achieve a desired temperature. The desired temperature can be based on one or more temperature setpoints and / or one or more humidity setpoints (e.g., therapeutic humidity).

[0218] The humidifier heater of the humidifier 12 can be controlled by the controller 13 to achieve a desired temperature. The desired temperature can be based on one or more temperature setpoints and / or one or more humidity setpoints. The desired temperature can be a therapeutic parameter.

[0219] The controller 13 can control the heater 16a of the breathing tube 16 and / or the humidifier heater of the humidifier 12 to the desired temperature by closed-loop control based on the output of one or more sensors.

[0220] The one or more temperature setpoints may be related to one or more treatment parameters of the device used for treatment (e.g., the dew point or temperature of the gas) or may be provided in the device's memory (e.g., a predetermined temperature). Various treatment parameters for various treatments are listed below; however, it should be understood that when a treatment parameter is mentioned in the specification, it may refer to any treatment parameter or any combination of treatment parameters. A treatment parameter may be a parameter of the gas supplied to the user by the device during treatment.

[0221] One or more treatment parameters may be a treatment humidity level. A treatment humidity level may be a measure indicating the humidity of the gas supplied to the user. For example, a treatment humidity level may be the relative humidity, absolute humidity, and / or dew point temperature of the gas.

[0222] The device can provide any combination of the following: high-flow nasal cannula (NHF) therapy, continuous positive airway pressure (CPAP) therapy, non-invasive ventilation (NIV), and bubble continuous positive airway pressure (BCPAP) therapy. The device may include one or more control modes associated with each therapy type. The control mode may be manually selected by the user or automatically selected based on the components connected to the device (e.g., based on the type of tubing and / or patient interface connected to the device). Each control mode may have an associated control scheme for controlling components of the device (e.g., a flow generator, humidifier heater 310, or tubing heater 16a).

[0223] The one or more treatment parameters used for NHF treatment may include any combination of the following: treatment flow rate of the gas supplied to the user, treatment humidity level (e.g., relative or absolute humidity, or dew point), treatment oxygen concentration supplied to the user, treatment concentration of the auxiliary gas supplied to the user, and treatment temperature of the gas supplied to the user (e.g.).

[0224] The one or more treatment parameters used for BCPAP treatment may include any combination of the following: treatment flow rate of the gas supplied to the user, treatment humidity level (e.g., relative or absolute humidity, or dew point), treatment oxygen concentration supplied to the user, treatment concentration of the auxiliary gas supplied to the user, and treatment temperature of the gas supplied to the user.

[0225] The one or more treatment parameters used for CPAP therapy may include any combination of the following: treatment humidity level (e.g., relative or absolute humidity, or dew point), treatment oxygen concentration provided to the user, treatment temperature of the gas provided to the user, treatment concentration of the auxiliary gas provided to the user, treatment level of pressure support provided to the user (e.g., CPAP pressure), and treatment PEEP pressure provided to the user.

[0226] The one or more treatment parameters used for bilevel therapy (i.e., NIV therapy) may include any combination of the following: treatment humidity level (e.g., relative or absolute humidity, or dew point), treatment oxygen concentration provided to the user, treatment temperature of the gas provided to the user, treatment concentration of the auxiliary gas provided to the user, and treatment IPAP / EPAP pressure (inspiratory positive airway pressure / expiratory positive airway pressure) provided to the user.

[0227] The treatment temperature may include the treatment temperature at the chamber outlet and / or the treatment temperature at the end of the breathing tube.

[0228] Therapeutic humidity can be applied at the chamber outlet or the end of the breathing tube.

[0229] The therapeutic humidity level can be a dew point of about 27 degrees Celsius to about 40 degrees Celsius, or about 29 degrees Celsius to about 39 degrees Celsius, or about 31 degrees Celsius to about 38 degrees Celsius, or about 37 degrees Celsius, or an absolute humidity of about 38 mg H2O or about 44 mg H2O.

[0230] Providing humidity to the user increases patient comfort and adherence to treatment. The provision of humidity also provides the additional benefit of improved mucus transport, which is useful for patients with obstructive pulmonary disease, improving comfort and thus improving adherence to / acceptance of such treatments.

[0231] Users can input one or more treatment parameters through the user interface.

[0232] The desired temperature may be at the end of the breathing tube 16, at the patient interface, at the gas outlet, at the humidification chamber outlet, at any sensor of the device, and / or any combination thereof.

[0233] The one or more temperature setpoints may include one or more of the following: desired dew point (e.g., temperature indicating desired humidity), predetermined dew point, predetermined temperature, desired temperature.

[0234] In some configurations, the controller 13 may control the heater 16a of the breathing tube 16 based on the desired temperature of the gas at the patient interface and / or the desired temperature at the end of the breathing tube 16.

[0235] The equipment can be powered by mains power (e.g., a wired connection to the power grid, or, for example, a portable generator, a distributed power source and / or a non-portable generator, such as a hospital backup generator).

[0236] Depending on the operating area of ​​the equipment, the mains power supply may be an AC power supply with a voltage level of about 100 VRMS to about 240 VRMS and a frequency of about 50 Hz to about 60 Hz.

[0237] In some configurations, the mains power supply can be any power source configured to be connected to the device via the electrical outlet 114.

[0238] In some configurations, the mains power supply may include any power source that has no energy availability and / or capacity limitations (e.g., like a battery).

[0239] The device may be powered by a non-peak power limited power source or a peak power limited power source (e.g., a battery). In this case, limited peak power refers to the peak power required for the device to operate at full capacity even during periods of higher power demand.

[0240] The device can be powered by an integrated power supply or an external power supply.

[0241] In some configurations, for example, as shown in FIG3, the device may include at least one battery 125 as part of a battery module (having a battery cover 126 if desired). The battery module may be located within the housing of the device and / or externally attached to the housing of the device (as shown in FIG3). It should be understood that when the term battery is used in the specification, the term may refer to the battery itself or the battery module that includes the battery.

[0242] In some configurations, the battery system is removable (as shown in Figure 3) and can be connected to and disconnected from device 10 as needed. Alternatively, the battery system is not removable.

[0243] In some configurations, the battery is provided as part of the same housing as the flow generator and / or humidifier. In some configurations, the battery is provided so that it can be connected and disconnected from the same housing as the flow generator and / or humidifier.

[0244] Integrating the battery into the housing or allowing it to be connected and disconnected from the housing allows the device to be portable compared to other devices, such as larger devices like ventilators or devices with non-portable external battery power. As described above, portability can increase the device's availability in home care settings because it can be moved more easily around the user's house. In hospital settings, portability allows the treatment device to be moved around the hospital with the patient, so the patient can continue receiving treatment while being transported.

[0245] The battery module can be a battery power source.

[0246] The battery 125 may include multiple cells that provide current (i.e., energy) and have a voltage (i.e., electromotive force) between their terminals.

[0247] The battery module may include a battery detection pin and / or a battery detection port. The battery detection pin and / or battery detection port may be configured to communicate with the device to which the battery is connected. The battery detection pin may include a pull-up or pull-down resistor connected to the battery detection pin.

[0248] The battery module may include one or more memory elements configured to store one or more battery parameters.

[0249] In the case where battery 125 includes multiple batteries, the battery parameters may relate to the batteries, or one or more batteries constituting battery 125.

[0250] In some configurations, battery parameters may relate to one or more battery cells.

[0251] These battery parameters may include: a) battery lifespan b) battery cell state c) battery charge state d) number of charge and discharge cycles e) battery capacity f) battery voltage g) battery current output h) battery temperature i) any combination of a) to h).

[0252] Device 10 may include an electrical outlet 114 configured to connect a power cord to the device to supply power to the device from an AC power source.

[0253] The power cord is detachably connected to the electrical outlet 114, so that if the power cord is damaged during use, it can be replaced without any rewiring of the device 10.

[0254] Device 10 may include a power cord holder 351 as shown in FIG3. The power cord holder 351 may be connected to the battery cover 126 of the battery 125 (e.g., as a battery module) such that during assembly, the power cord will be attached to device 10 after the battery cover 126, with the power cord holder 351 being attached last. Alternatively, the power cord holder 351 may be connected to different parts of housing 100.

[0255] The device can be configured to detect whether the device operates using a battery or AC power. As shown in Figures 4 and 4A, device 10 may include a power detection circuit 510. The power detection circuit 510 may include one or more voltage detection circuits and / or one or more current detection circuits. The power detection circuit 510 is shown as transmitting power from battery 125 and AC power 501; however, it should be understood that this is a high-level diagram and in some embodiments, the power detection circuit 510 may control one or more switches configured to connect the control circuit system to an appropriate power source.

[0256] The device 10 can be configured to operate on battery power when no mains power is detected.

[0257] The device can be configured to operate using battery power (e.g., battery 125) based on input from the user (via a user interface if necessary). In this case, if battery 125 is detected, the power detection circuit 510 can allow the user to select only the battery as the power source.

[0258] The device may include a battery charger configured to charge battery 125. The device may be configured to charge the battery when the device is powered by an AC power source (and, if necessary, when the AC power source voltage is above a threshold, such as 110 V or 230 V) and when the battery is not fully charged (and, if necessary, when the battery charge is below a charge threshold, such as 95%).

[0259] As described above, the battery module can transmit one or more battery parameters to the controller 13.

[0260] In some configurations, the battery can communicate with the controller 13 to request charging by the battery charger until the battery 125 is fully charged. In some configurations, the battery module includes a battery monitor that monitors one or more battery parameters.

[0261] In some configurations, battery charging and monitoring are performed by a circuit system within the battery pack. In some configurations, battery charging and monitoring are performed by a circuit system within the device.

[0262] Device 10 may include a power rail configured to supply power to the device.

[0263] The device 10 may include an AC power conversion circuit.

[0264] The AC power conversion circuit can be configured to convert AC power to rail power (e.g., rail voltage) to power the device, as shown in Figure 5B, for example.

[0265] In some configurations, the equipment or at least some of its components may be directly powered by mains power.

[0266] The mains power conversion circuit system may include one or more switch-mode power supplies (or, for example, any other AC to DC converter).

[0267] The AC power conversion circuit can be configured to convert AC power to a low DC voltage (approximately 3 volts DC to approximately 60 volts DC, depending on the requirements).

[0268] Device 10 may include a battery conversion circuit.

[0269] The battery conversion circuit can be configured to convert the battery output to a power rail (e.g., power rail voltage) to power the device, as shown in Figure 5B, for example.

[0270] The battery conversion circuit can be configured to convert the battery to a low DC voltage (approximately 3 volts DC to approximately 60 volts DC, depending on the requirements).

[0271] The battery conversion circuit can be configured to increase or decrease the battery output voltage according to the characteristics of the battery and device components.

[0272] The battery conversion circuit may include a DC-DC converter.

[0273] In some configurations, the battery conversion circuit may include: a) a buck converter b) a DC-DC converter c) a boost converter d) a boost converter e) a half-bridge converter f) a flyback converter g) a push-pull converter h) a switching converter i) a switching regulator j) a linear regulator k) a linear converter l) a buck converter m) a transformer n) any combination of a) to m)

[0274] The mains power conversion circuit and / or battery conversion circuit can supply power to the device and / or one or more components of the device according to the power supply used by the device.

[0275] In some configurations, the digital control circuitry and the analog control circuitry supply power from the power rail to the heaters (multiple).

[0276] For example, as shown in Figure 2, the oxygen inlet port 28 includes a valve 1003 through which pressurized gas enters the respiratory therapy device 10. The valve controls the flow rate of oxygen entering the respiratory therapy device 10. The valve can be any type of valve, including proportional valves or two-position valves.

[0277] The oxygen source can be an oxygen cylinder or a hospital oxygen supply source. Medical-grade oxygen typically has a purity between 95% and 100%. Lower purity oxygen sources can also be used. Examples of valve modules and filters are disclosed in U.S. Provisional Application No. 62 / 409,543, filed October 18, 2016, entitled "Valve Modules and Filter," and U.S. Provisional Application No. 62 / 488,841, filed April 23, 2017, entitled "Valve Modules and Filter," which are incorporated herein by reference in their entirety.

[0278] The respiratory assist device 10 can measure and control the oxygen content of the gas delivered to the patient, and thus measure and control the oxygen content of the gas inhaled by the patient.

[0279] The respiratory assist device 10 can provide high-flow therapy in which the high flow rate of the delivered gas meets or exceeds the patient’s peak inspiratory demand.

[0280] Operational sensors 3a, 3b, 3c (such as flow sensors, temperature sensors, humidity sensors, and / or pressure sensors) may be placed in various locations within the respiratory assist device 10. Additional sensors (e.g., sensors 20, 25) may be placed in various locations on the breathing tube 16 and / or the patient interface 17 (e.g., a temperature sensor 29 may be present at or near the end of the inspiratory tube).

[0281] The respiratory therapy device 10 may have a communication module 15 that enables the controller 13 to receive signals 8 from sensors and / or control various components of the respiratory assist device 10, including but not limited to the flow generator 11, humidifier 12, heater 16a, humidifier heater, or accessories or peripheral devices associated with the respiratory assist device 10. Alternatively or additionally, the communication module 15 may transmit data to a remote server or enable remote control of the respiratory therapy device 10 or the respiratory therapy system 1.

[0282] The communication module may include a transmitter, a receiver and / or a transceiver.

[0283] The communication module 15 can be used as a network interface (e.g., as a modem).

[0284] The communication module 15 may use one or more communication protocols known in the art, such as Wi-Fi, Bluetooth, Zigbee, cellular (3G, 4G or 5G, etc.).

[0285] The communication module 15 can enable communication between the device and a mobile device (e.g., a phone or tablet via Bluetooth or Wi-Fi).

[0286] The communication module may include multiple individual transmitters, receivers and / or transceivers for each or group of (multiple) communication protocols.

[0287] The communication module 15 can be configured to send and receive data from one or more devices (e.g., servers), as described in more detail below.

[0288] In some configurations, one or more leak or blockage events or alarms (as described in more detail below) may be transmitted to one or more servers and / or devices (e.g., computers, phones, or tablets). Additional information associated with the event or alarm (e.g., time, duration, or severity) may be additionally transmitted to the server and / or device.

[0289] As described above, the respiratory assist device 10 can measure and control the oxygen content of the gas delivered to the patient. After the oxygen and ambient air have been mixed, the oxygen can be measured by placing one or more gas composition sensors (such as an ultrasonic transducer system). The measurement can be performed within the respiratory therapy device 10, the patient breathing tube 16, the patient interface 17, or at any other suitable location.

[0290] The oxygen concentration measured in the device can be equivalent to the delivered oxygen fraction (FdO2) and can be substantially the same as the oxygen concentration of the patient’s breath, the inhaled oxygen fraction (FiO2), and therefore these terms can be considered equivalent.

[0291] The flow rates of at least two gases can also be determined by measuring the oxygen concentration using flow sensors on at least two of the ambient air inlet tubing, oxygen inlet tubing, and patient breathing tubing. The oxygen concentration of the final gas composition can be calculated by determining the flow rates of the two inlet gases or one inlet gas, along with a total flow rate and a hypothetical or measured oxygen concentration of the inlet gases (approximately 20.9% for ambient air and approximately 100% for oxygen). Alternatively, flow sensors can be placed at all three inlets—ambient air inlet tubing, oxygen inlet tubing, and breathing tubing—to allow redundancy and to test the correct operation of each sensor by checking the consistency of the readings. Other methods for measuring the oxygen concentration delivered by the respiratory assist device 10 can also be used.

[0292] The respiratory assist device 10 may include a patient sensor 26 (such as a pulse oximeter or a patient monitoring system) to measure one or more physiological parameters of the patient (such as the patient's blood oxygen concentration (e.g., the patient's blood oxygen saturation (SpO2)), heart rate, respiratory rate, perfusion index) and provide a measure of signal quality. The sensor 26 may communicate with the controller 13 via a wired connection or via communication through a wireless transmitter on the sensor 26. The sensor 26 may be a disposable adhesive sensor designed to attach to the patient's finger. The sensor 26 may be a non-disposable sensor (i.e., a reusable sensor). Sensors designed for different age groups and attached to different locations on the patient are available and can be used with the respiratory assist system 1. The pulse oximeter may be attached to the patient (typically on their finger), but other locations (such as the earlobe) are also an option. The pulse oximeter may be connected to a processor in the respiratory therapy device 10 and may continuously provide a signal indicating the patient's blood oxygen saturation. The patient sensor 26 may be a hot-swappable device that can be attached to or interchanged during operation of the respiratory assist device 10. For example, the patient sensor 26 may be connected to the respiratory assist device 10 using a USB interface or a wireless communication protocol such as Bluetooth®.

[0293] When the patient sensor 26 disconnects during operation, the respiratory assist device 10 may continue operating in its previous operating state for a defined period of time. After the defined period of time, the respiratory assist device 10 may trigger an alarm, switch from automatic mode to manual mode, and / or exit control mode completely (e.g., automatic or manual mode). The patient sensor 26 may be a bedside monitoring system or other patient monitoring systems that communicate with the respiratory assist device 10 via a physical or wireless interface.

[0294] The respiratory assist device 10 may include a high-flow therapy device or a high-flow therapy device.

[0295] The high-flow therapy discussed herein is intended to be given its typical, common meaning as understood by those skilled in the art, and generally refers to respiratory assist devices that deliver a target flow rate of humidified respiratory gas via an intentionally unsealed patient interface at a flow rate generally designed 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 typically range from, but are not limited to, about 15 liters / minute to about 60 liters / minute or greater. Typical flow rates for pediatric patients (such as newborns, infants, and children) typically range from, but are not limited to, about 1 liter / minute / kg patient weight to about 3 liters / minute / kg patient weight or greater. High-flow therapy may also include, as needed, a gas mixture composition that includes supplemental oxygen and / or administration of therapeutic drugs. High-flow therapy is commonly 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.

[0296] For example, in some configurations, for adult patients, "high-flow-rate therapy" may refer to delivering gas to the patient at a flow rate of about 10 liters per minute (10 LPM), such as between about 10 LPM and about 100 LPM, or between about 15 LPM and about 95 LPM, or between about 20 LPM and about 90 LPM, or between about 25 LPM and about 85 LPM, or between about 30 LPM and about 80 LPM, or between about 35 LPM and about 75 LPM, or between about 40 LPM and about 70 LPM, or between about 45 LPM and about 65 LPM, or between about 50 LPM and about 60 LPM. In some configurations, for neonatal, infant, or pediatric patients, "high-flow therapy" may refer to delivering gas to the patient at a flow rate greater than 1 LPM, such as between about 1 LPM and about 25 LPM, or between about 2 LPM and about 25 LPM, or between about 2 LPM and about 5 LPM, or between about 5 LPM and about 25 LPM, or between about 5 LPM and about 10 LPM, or between about 10 LPM and about 25 LPM, or between about 10 LPM and about 20 LPM, or between about 10 LPM and about 15 LPM, or between about 20 LPM and 25 LPM. In some configurations, high-flow therapy devices for adult, neonatal, infant, or pediatric patients may deliver gas to the patient at a flow rate between about 1 LPM and about 100 LPM, or at any of the sub-ranges outlined above. The delivered gas may include a percentage of oxygen. In some configurations, the percentage of oxygen in the delivered gas can be between about 20% and about 100%, or between about 30% and about 100%, or between about 40% and about 100%, or between about 50% and about 100%, or between about 60% and about 100%, or between about 70% and about 100%, or between about 80% and about 100%, or between about 90% and about 100%, or about 100%, or 100%.

[0297] High-flow therapy can be effective in meeting or exceeding the patient's inspiratory flow, enhancing the patient's oxygenation and / or reducing the work of breathing.

[0298] High-flow therapy can be administered through the patient’s nostrils and / or mouth, or via a tracheostomy interface.

[0299] High-flow-rate therapy can produce a flushing effect in the nasopharynx, flushing the anatomical dead space of the upper airway with a high flow rate of gas. This can create a reserve of fresh gas available for each breath, while reducing the need for rebreathing of nitrogen and carbon dioxide. Additionally, meeting inspiratory needs and flushing the airway are important when attempting to control a patient's FdO2. High-flow-rate therapy can be delivered using a non-sealed patient interface (e.g., a nasal cannula). High-flow-rate therapy may reduce the patient's respiratory rate. High-flow-rate therapy may provide expiratory resistance to the patient.

[0300] High-flow therapy can be used to treat patients with obstructive pulmonary disease (e.g., COPD, bronchiectasis, dyspnea, cystic fibrosis, emphysema) and / or patients with respiratory distress or hypercapnia.

[0301] As used herein, the term "unsealed patient interface" (i.e., an unsealed patient interface) can refer to an interface that provides a pneumatic connection between a patient's airway and a gas flow source (such as from flow generator 11) that does not completely obstruct the patient's airway. An unsealed pneumatic connection may include an obstruction of less than about 95% of the patient's airway. An unsealed pneumatic connection may include an obstruction of less than about 90% of the patient's airway. An unsealed pneumatic connection may include an obstruction between about 40% and about 80% of the patient's airway. The airway may include one or both of the patient's nostrils and / or the patient's mouth. For nasal intubation, the airway passes through the nostrils.

[0302] In some configurations, the "non-sealed patient interface" may include the tracheal interface.

[0303] CPAP therapy may include delivering gas to the user at continuous positive pressure (and, as needed, one or more treatment parameters, as described in more detail above).

[0304] BCPAP treatment may include delivering gas to the user at a treatment flow rate (and, as needed, one or more treatment parameters, as described in more detail above).

[0305] Bilevel therapy may include delivering gas to the user to treat IPAP and EPAP (and, as needed, one or more treatment parameters, as described in more detail above).

[0306] A sealed interface may be used when the device is used to provide CPAP, bilevel or BCPAP treatment.

[0307] The flow generator 11 may be or include a blower module. The blower module may include at least one blower 11 configured to generate the gas flow.

[0308] The flow generator 11 may include an ambient air inlet port 27 through which ambient indoor air can be introduced into the blower. The breathing aid device 10 may also include an oxygen inlet port 28 leading to a valve through which pressurized gas can enter the flow generator 11. The valve can control the oxygen flow rate entering the flow generator 11. The valve can be any type of valve, including a proportional valve or a two-position valve.

[0309] The blower 11 can operate at a motor speed greater than about 1,000 RPM and less than about 8,000 RPM, greater than about 2,000 RPM and less than about 10,000 RPM, or any of the foregoing values. The blower 11 can mix gases entering the blower 11 through gas inlets (e.g., ambient air inlet port 27 and / or oxygen inlet port 28). Using the blower 11 as a mixer can reduce the pressure drop relative to a system having a separate mixer (such as a static mixer including baffles).

[0310] The respiratory assist device may further include a gas composition sensor. The gas composition sensor may be a sensor as described below (e.g., an ultrasonic transducer configuration).

[0311] The respiratory assist device 10 includes a flow sensor. The flow sensor can be configured to measure the flow rate of breathable gas flowing to the patient.

[0312] Controller 13 may include one or more processors. The processors may be configured with computer-readable instructions.

[0313] The controller 13 may include at least one memory element. The memory element may be configured to store the computer-readable instructions.

[0314] Memory elements may be non-transitory computer-readable media.

[0315] The controller 13 may be a microprocessor or ASIC, FPGA, or a combination of IC or microprocessor, or other suitable components and / or architecture.

[0316] The respiratory assist device may include at least one display module configured to display alarm output.

[0317] The breathing assist device may include at least one sound module configured to emit an audible alarm.

[0318] In some configurations, the at least one sound module may include a speaker.

[0319] The display module may include at least one display (e.g., a liquid crystal display (LCD) or a light-emitting diode (LED) display, but it should be understood that any display technology may be used).

[0320] The display module can be configured to receive input to the system (e.g., as a touch screen) and is therefore at least a part of the user interface 14 or displays a part of the user interface.

[0321] The display module can be configured as an input / output (I / O) module. For example, the display module can be configured to receive input from the user and provide output to the user (e.g., as part of user interface 14 or as part of displaying the user interface).

[0322] The display module can communicate with the controller 13. In some configurations, the display module can provide information (e.g., setpoints) to the controller 13. In some configurations, the display module can receive information (e.g., alarms, sensor outputs, and / or other calculated variables) from the controller 13.

[0323] Some examples of flow therapy devices are disclosed in international application PCT / NZ 2016 / 050193, filed on December 2, 2016, entitled “Flow Path Sensing for Flow Therapy Apparatus”, and international application PCT / IB 2016 / 053761, filed on June 24, 2016, entitled “Breathing Assistance Apparatus”, the entire contents of which are incorporated herein by reference.

[0324] For example, as shown in Figure 2, the respiratory assist device includes a housing 100. The housing 100 has an upper housing 102 and a lower housing 202. However, it should be understood that in some configurations, the housing may have multiple components.

[0325] For example, as shown in FIG6, device 10 may include a valve module that controls the flow rate of oxygen and / or other gases entering the gas flow path of device 10 and enables device 10 to adjust the proportion of oxygen entrained in the airflow. The valve module is formed as a modular unit to facilitate manufacturing, assembly, repair, or replacement. For example, in the event of a malfunction, routine maintenance, or future upgrade / improvement.

[0326] The valve module can be configured to operate to control the oxygen concentration of the gas supplied to the user at a therapeutic oxygen concentration.

[0327] Device 10 may include filter module 1001, which may include a filter.

[0328] The filter modules and valve modules described herein can provide varied gas flow paths for the equipment. For example, the valve module can control the oxygen flow rate entering the equipment via the valve module and filter module. Alternatively, an alternative oxygen source can be connected directly to the filter module via an alternative supply inlet, bypassing the valve module. This is useful in situations where the user may wish to manually adjust the oxygen supply source (i.e., via a wall-mounted supply rotor flow meter).

[0329] It should be understood that the filter modules and valve modules described herein can be used separately in devices used to deliver gas streams. Alternatively, the filter and valve modules can be used together as a filter and valve assembly to achieve improved functionality.

[0330] In the configuration shown, the device 10 receives oxygen by at least one of the following methods: via a valve module (for automatic oxygen regulation of the device), or via an alternative gas inlet located on top of the filter (allowing attachment of a manually adjustable oxygen supply - such as a wall supply regulated by a regulator).

[0331] In some configurations, the alternative gas inlet may be provided with a therapeutic gas that is not oxygen (e.g., a helium-oxygen mixture).

[0332] The device 10 may include a manifold. The manifold may be located on the housing. The manifold may provide one or more of the following: an oxygen inlet, an alternative gas inlet, and / or an air inlet.

[0333] The manifold can supply oxygen, alternative gases and / or ambient air to valve modules, filter modules and / or blowers.

[0334] The manifold can be located upstream of the hair dryer.

[0335] The oxygen inlet or alternative gas supply inlet can be located on one side of the manifold.

[0336] The manifold allows excess oxygen to escape into the surrounding environment, and / or if the blower is off and oxygen is continuously supplied, the manifold allows oxygen to escape into the surrounding environment. This prevents O2 buildup in the housing.

[0337] The manifold may include one or more baffles that facilitate mixing oxygen and / or alternative gases and air.

[0338] The manifold may also include filters configured to filter oxygen and / or alternative gases and / or air from the respective inlets.

[0339] The various configurations described are merely exemplary configurations. Any one or more features from any configuration may be used in combination with any one or more features from any other configuration.

[0340] In some configurations, the motor and / or sensor sub-assemblies (e.g., including one or more sensors) may be located in the housing.

[0341] The motor and / or sensor subassemblies may be located in a recess on the lower side of the housing. The recess may alternatively be located at the rear, side, front, or top of the housing. The air and / or oxygen inlet may also be located differently depending on requirements.

[0342] As another example, instead of configuring the humidification chamber and the recess such that the humidification chamber is inserted into and removed from the recess from the front of the housing, the configuration can be such that the humidification chamber is inserted into and removed from the recess from the side, rear or top of the housing.

[0343] As another example, although the filter module is described as being inserted into the housing from above and the valve module from below, any one or both of these components may be inserted into any suitable part of the housing, such as the upper part, lower part, side part, front part, or rear part.

[0344] The filter module and valve module are described with reference to a respiratory assist device that can deliver heated and humidified gas to a patient or user.

[0345] Alternatively, the filter module and / or valve module can be used with devices that do not require a humidifier and therefore do not require a humidification chamber 300. For example, it should be understood that configurations that isolate the motor and gas flow path from electrical and electronic components are widely used in other types of gas delivery devices.

[0346] As described above, the device is configured to be powered by a battery or mains power (as shown in Figures 4 and 4A, for example).

[0347] The controller 13 can be configured to control the heater of the humidifier and / or the heater of the duct according to the first control scheme and the second control scheme.

[0348] In some configurations, controller 13 can transmit commands to humidifier heater sub-controller and / or duct heater sub-controller.

[0349] In some configurations, the first control scheme is the first power control scheme.

[0350] In some configurations, the second control scheme is the second power control scheme.

[0351] When the device is powered by battery 125, the controller is configured to control the heater of the humidifier and / or the heater of the duct according to the first control scheme.

[0352] In some configurations, when the device is powered by a peak power-limited power supply, the controller is configured to control the heater of the humidifier and / or the heater of the duct according to a first control scheme.

[0353] In some configurations, when the device is powered by an integrated power supply, the controller is configured to control the heater of the humidifier and / or the heater of the duct according to a first control scheme.

[0354] The control schemes described below relate to the heaters of the duct and the humidifier, but it should be understood that such control schemes may also be applied to only one of the heaters (instead of both as described below).

[0355] The first control scheme may include, for example, controlling the heater of the humidifier by digital control (e.g., digital power control), as shown in FIG5.

[0356] Alternatively or alternatively, the first control scheme may include, for example, controlling the heater of the conduit by analog control (e.g., analog power control), as shown in FIG5.

[0357] In some configurations, the first control scheme may include, for example, controlling the heater of the humidifier by analog control (e.g., analog power control), as shown in FIG5A.

[0358] When the device is powered by mains power, the controller is configured to control the heater of the humidifier and / or the heater of the duct according to the second control scheme.

[0359] In some configurations, when the device is powered by a non-peak power limited power supply, the controller is configured to control the heater of the humidifier and / or the heater of the duct according to a second control scheme.

[0360] In some configurations, when the device is powered by an external power source, the controller is configured to control the heater of the humidifier and / or the heater of the duct according to a second control scheme.

[0361] The second control scheme may include controlling the heater of the humidifier by digital control.

[0362] Alternatively or alternatively, the second control scheme may include controlling the heater of the conduit by digital control.

[0363] The first control scheme may include providing a high-frequency pulse width modulation signal to the heater of the humidifier.

[0364] The second control scheme may include providing a low-frequency pulse width modulation signal to the heater of the humidifier.

[0365] The frequency of a high-frequency pulse width modulation signal is greater than the frequency of a low-frequency pulse width modulation signal.

[0366] Figure 5 shows an example of a first control scheme 601 and a second control scheme 602, which are used to control the heater of the humidifier and the heater of the duct based on whether the device operates by relying on battery 125 or mains power.

[0367] The first control scheme 601 includes controlling the humidifier heater by providing a high-frequency pulse width modulation signal via digital control. The first control scheme 601 further includes controlling the duct heater by providing an analog control signal (e.g., a voltage signal) via analog control.

[0368] The second control scheme 602 includes controlling the humidifier heater by providing a low-frequency pulse width modulation signal via digital control. The second control scheme 602 further includes controlling the duct heater by providing a pulse width modulation signal (as needed, a low-frequency pulse width modulation signal as described elsewhere) via digital control.

[0369] Figure 5A shows alternative examples of the first control scheme 601' and the second control scheme 602', which are used to control the heater of the humidifier and the heater of the duct based on whether the device is operated by battery 125 or by mains power.

[0370] The first control scheme 601' includes controlling the humidifier heater by providing an analog control signal. The first control scheme 601' further includes controlling the duct heater by providing an analog control signal (e.g., a voltage signal).

[0371] The second control scheme 602 includes controlling the humidifier heater by providing a pulse width modulation signal (a low-frequency pulse width modulation signal, if needed) via digital control. The second control scheme 602 further includes controlling the duct heater by providing a pulse width modulation signal (a low-frequency pulse width modulation signal, as described elsewhere, if needed) via digital control.

[0372] In some configurations, when the device is initially powered by a power-limited power source (i.e., a battery) – as shown in step 911 of FIG8 (e.g., when entering the first control scheme 601, 601'), the device can be configured to disable the humidifier heater and / or the duct heater, as shown in step 912 of FIG8.

[0373] Disabling the humidifier heater and / or conduit may include one or more of the following: disabling the control circuitry (e.g., analog control circuitry and / or digital control circuitry) and / or providing a shutdown control signal.

[0374] The device may be initially powered by a power-limited power source when the device is switched to battery, for example when the mains power is removed.

[0375] The device can then (if necessary, after a predetermined amount of time) control the humidifier heater and / or duct heater to a desired value (e.g., desired power, or to achieve desired therapeutic parameters) or a certain percentage of the desired value, as shown in step 913 of Figure 8. The device can control the humidifier heater and / or duct heater, for example by increasing the control signal to the desired value by increasing the control signal (e.g., a digital control signal or an analog control signal). This prevents the heater activation from exceeding the battery's (multiple) peak ratings.

[0376] The device can control the humidifier heater and / or duct heater to a desired value or a certain percentage of the desired value at a predetermined rate or below a predetermined rate.

[0377] In some configurations, when the device is powered by a power-limited power source (i.e., a battery) (e.g., when entering the first control scheme 601, 601') – as shown in step 911 of FIG9, the device can be configured to deliver power to the flow generator (or, if necessary, the blower of the flow generator) over the humidifier heater and / or the duct heater. The battery rated power can be set to a power budget, which can be allocated to the flow generator, the humidifier heater, and the duct heater. The power budget can be allocated to the flow generator over the humidifier heater and / or the duct heater – as shown in step 914 of FIG8.

[0378] For example, if the battery is rated to have a power of 100 W and the combined power of the hair dryer, humidifier heater and duct heater is expected to be greater than 100 W, then the hair dryer will be allocated power over the humidifier heater and / or duct heater.

[0379] In some configurations, the power delivered to the humidifier heater and / or conduit heater will be based on the remaining power of the power budget—as shown in step 915 of Figure 8. The remaining power of the power budget may be the power budget minus the power required to power the flow generator (e.g., to the treatment flow rate and / or treatment pressure). If the remaining power is greater than the combined desired power of the humidifier heater and / or conduit heater, the device may be configured to reduce the power supplied to the humidifier heater and / or conduit heater (as needed, to the remaining power budget).

[0380] For example, if the remaining power budget is 60 W and the desired power is greater than 60 W, the power delivered to the humidifier heater and / or duct heater can be reduced to 60 W.

[0381] In some configurations, when the device is powered by a power-limited power source (i.e., a battery) (e.g., when entering the first control scheme 601, 601'), the device can be configured to disable the humidifier heater and / or the duct heater when the battery charge reaches a threshold (e.g., by not providing a control signal and / or providing zero control signal). In some configurations, the threshold is about 5% to about 40%, or about 10% to about 30%, or about 20%.

[0382] Digital control may include generating signals having an on state and an off state. The off state signal level may be ground (or 0 volts) and the on state signal level may be the power supply voltage (e.g., a power supply voltage from one or more battery conversion circuits and / or mains power conversion circuits as described in more detail above, and / or a voltage from one or more voltage conversion circuits). The signals may then be provided to the heater to control the heater.

[0383] The conduction state can be, for example, any suitable positive or negative voltage.

[0384] The magnitude of the on-state voltage can be selected based on the expected range of (multiple) anticipated power demands, the electrical characteristics of the heater, and / or the maximum permissible value for keeping the PWM frequency within EMI requirements. It should be understood that various devices may have different supply voltages and may increase or decrease the supply voltage to power the heating element—in which case the on-state can be based on the increased or decreased voltage.

[0385] Digital control may include, for example, pulse width modulation (as shown in Figures 7A and 7B). However, it should be understood that in some configurations, digital control may include pulse density modulation (PDM) and pulse frequency modulation (PFM).

[0386] Analog control may provide analog control signals (e.g., modulated voltage or current signals) to the heater of the duct and / or the heater of the humidifier.

[0387] Providing analog control signals may include controlling, modulating, or regulating analog signals provided to the conduit heater. In a voltage signal configuration, a voltage signal may be provided across the terminals of the conduit heater. In a current signal configuration, a current signal may be provided to the conduit heater.

[0388] It should be understood that the analog control signal may be generated based on one or more electrical characteristics of the heater(s) and / or the associated circuitry of the heater(s). For example, the voltage signal may be generated based on the measured resistance and / or current of the heater(s) and / or the associated circuitry of the heater(s).

[0389] Analog control may include generating continuous (or approximately continuous) control signals, such as continuous voltage signals or continuous current signals.

[0390] Analog control may include generating periodic or non-periodic signals. Periodic signals may be smooth (e.g., a sine wave as shown in Figure 7E) or non-smooth (e.g., a triangular wave as shown in Figure 7D).

[0391] In some configurations, analog power control may include generating a sine wave and / or a modified sine wave as an analog control signal. The sine wave and / or the modified sine wave may be generated based on the desired power to be supplied to the heater.

[0392] The characteristics or parameters of the generated and / or modified sine waves can be varied according to the voltage and / or current and / or power requirements of the heater. For example, the amplitude, magnitude, frequency and / or DC offset of (multiple) waves can be controlled.

[0393] The analog control signal can be, for example, a continuous signal that varies between 0 volts and the supply voltage (e.g., as shown in Figure 7C) – this is the opposite of a digital control signal that may have a discrete value of 0 volts or the supply voltage.

[0394] Figure 7C shows an example analog control signal as a voltage signal. As described elsewhere, the analog control signal can be controlled by a controller to achieve a specific control output (i.e., a specific power delivery and / or a specific treatment parameter) and varies between ground and supply voltage. In some portions of the signal shown in Figure 7C, the voltage reaches the supply voltage and is grounded.

[0395] Figure 7D shows another example of an analog control signal as a voltage signal. In Figure 7D, the analog control signal is a triangular wave. In some configurations, the triangular wave can be symmetrical or asymmetrical. In some configurations, the triangular wave can be a sawtooth wave.

[0396] Figure 7E shows another example of an analog control signal as a voltage signal. In Figure 7D, the analog control signal is sinusoidal.

[0397] The digital control pulse width modulation signal (e.g., low-frequency pulse width modulation signal and high-frequency pulse width modulation signal) can be a periodic rectangular pulse type signal that switches between ground (i.e., 0 volts) and power supply voltage level (e.g., power supply voltage from one or more batteries or mains power conversion circuits, as described in more detail above).

[0398] Figures 7A and 7B show examples of low-frequency pulse width modulation signals and high-frequency pulse width modulation signals, respectively, and their interrelationships.

[0399] The duty cycle of the low-frequency pulse width modulation signal in Figure 7A is approximately 50%, and is the same as the duty cycle of the high-frequency pulse width modulation signal in Figure 7B. However, the frequency of the low-frequency pulse width modulation signal (in Figure 7A) is lower than the frequency of the high-frequency pulse width modulation signal (in Figure 7B).

[0400] The controller 13 of the device 10 can be configured to control the duty cycle of the pulse width modulation signal to perform the following operations: a) control the heater of the humidifier or the heater of the conduit to achieve one or more temperatures (e.g., the temperature of the heater of the humidifier), b) control the heater of the humidifier or the heater of the conduit to achieve therapeutic parameters (e.g., therapeutic humidity level), c) control the heater of the humidifier or the heater of the conduit to achieve one or more desired powers.

[0401] It should be understood that the control output in all such cases can be power (i.e., 0% to 100% duty cycle).

[0402] As described above, the heater of the equipment can be controlled by digital or analog control. Examples of control methods for duct heaters and / or humidifier heaters: Digital control Pulse width modulation (e.g., low-frequency pulse width modulation or high-frequency pulse width modulation) Analog Control Voltage modulation Current modulation Resistance modulation

[0403] Each control method described above may have specific advantages and disadvantages for a particular heater and a particular device.

[0404] For example, as described above, high-frequency pulse width modulation may generate more EMI compared to low-frequency pulse width modulation or analog control (especially when used to power the heater of the conduit).

[0405] However, high-frequency pulse width modulation may have lower peak power requirements compared to low-frequency pulse width modulation, especially when paired with suitable energy storage (e.g., capacitor energy storage).

[0406] Given that high-frequency pulse width modulation does not have the same negative EMI effect when used to power the heater of a humidifier (because of the minimal antenna effect) and has a lower peak power requirement, high-frequency pulse width modulation may be beneficial for use in controlling the heater of a humidifier in certain situations (e.g., when powered by a peak power-limited power source—i.e., a battery).

[0407] Regarding analog control—Analog control may generate less EMI than digital control.

[0408] However, in analog control, the control circuitry required to generate the desired analog signal is generally more expensive and complex than that of digital control circuitry because it typically requires more electrical and / or electronic components. Because analog control does not have the digital control signal that varies between a fully on and fully off state, the instantaneous peak power draw in analog control is generally smaller than that in digital control, since the power supply does not need to provide the sudden current surge associated with the transition from the off state to the on state in digital control. Analog control can also provide a more consistent signal with a lower rate of power change compared to digital control, which delivers a much higher rate of power change during switching, potentially resulting in a larger peak power draw from the power supply.

[0409] discloses various analog control methods. Analog control by voltage modulation can be achieved by providing a voltage signal to the heater. Analog control by current modulation can be achieved by providing a current signal to the heater. Analog control by resistance modulation can indirectly control the power delivered to the heater by changing the resistance of components in a circuit having a voltage power supply and a heater. In some configurations, the components can be, for example, digital potentiometers (or other electronically controllable resistor components).

[0410] Analog control via voltage modulation may require the use of switching components (such as transistors, like MOSFETs) that generate EMI in the control circuit system (however, this may be less common when controlling the heater of the duct because the heater of the duct requires less power than the heater of the humidifier).

[0411] Analog control via current modulation may require additional components and control complexity, which may lead to additional component costs. However, analog control can reduce the need for power rail capacitors, which can reduce component costs.

[0412] Analog control by resistor modulation may require additional components and control complexity, which may result in additional component costs. However, due to the lack of switching components in the control circuit system, the generated EMI may be lower than other analog control methods.

[0413] As shown in Figures 4 and 4A, device 10 includes a conduit heater analog control circuit system 512. The conduit heater analog control circuit system 512 may include, for example, a voltage converter (described in more detail below). The conduit heater analog control circuit system 512 is configured to generate an analog control signal for the conduit heater. In some configurations, the conduit heater analog control circuit system may modify the analog control signal for the conduit heater based on an output from a controller.

[0414] In an alternative configuration shown in FIG. 4A, device 10 includes a humidifier heater analog control circuitry system 514. The humidifier heater analog control circuitry system 514 may include, for example, a voltage converter (described in more detail below). The humidifier heater analog control circuitry system 514 is configured to generate an analog control signal for the humidifier heater. In some configurations, the humidifier heater analog control circuitry system may modify the analog control signal for the humidifier heater based on an output from a controller.

[0415] The output from the controller may be the desired duty cycle, power, temperature, treatment parameter level, or a desired change in its parameters.

[0416] The controller can calculate the necessary analog control signals, or the controller can simply provide the desired power, temperature, treatment parameter levels, etc., and the analog control circuitry will adjust the signals accordingly. The analog circuitry can also be configured to receive current signals and / or desired changes in current power, temperature, treatment parameter levels.

[0417] As shown in Figures 4 and 4A, device 10 includes a digital control circuit system 513 for a conduit heater. The digital control circuit system is configured to generate a pulse width modulation signal for the conduit heater. In some configurations, the digital control circuit system can change the duty cycle of the pulse width modulation signal for the conduit heater based on an output from a controller.

[0418] The output from the controller may be the desired duty cycle, power, temperature, treatment parameter level, or a desired change in its parameters.

[0419] The controller can calculate the necessary duty cycle itself, or the controller can simply provide the desired power, temperature, treatment parameter level, etc., and the digital control circuitry will adjust the duty cycle accordingly. The digital control circuitry can also be configured to receive current signals and / or desired changes in current power, temperature, treatment parameter level.

[0420] As shown in Figures 4 and 4A, device 10 includes a digital control circuit system 512 for a humidifier heater. The digital control circuit system 512 is configured to generate a pulse width modulation signal for the humidifier heater. In a first control scheme, the digital control circuit system 511 is configured to generate a low-frequency pulse width modulation signal, and in a second control scheme, the digital control circuit system 511 is configured to generate a high-frequency pulse width modulation signal.

[0421] The digital control circuit system (e.g., the duct heater digital control circuit system 513 and / or the humidifier heater digital control circuit system 511) may include one or more switching circuits.

[0422] The digital control circuit system (e.g., the duct heater digital control circuit system 513 and / or the humidifier heater digital control circuit system 511) may include one or more pulse width modulation drivers. The pulse width modulation drivers are configured to generate pulse width modulation signals provided to the humidifier heater and / or the duct heater.

[0423] A pulse width modulation (PWM) driver may include integrated circuitry, discrete component circuitry, or a combination of both. For example, a PWM driver may include control circuitry, MOSFET gate driver circuitry, and / or other suitable PWM hardware as understood in the art.

[0424] In some configurations, the humidifier heater digital control circuitry 511 may include a pulse width modulation driver configured to generate a pulse width modulation signal for the duct heater.

[0425] In some configurations, the humidifier heater digital control circuit system 511 may include a pulse width modulation driver configured to generate a high-frequency pulse width modulation signal and a low-frequency pulse width modulation signal.

[0426] When the equipment is controlling the heater of the conduit according to the second control scheme, the analog control circuit system is disabled.

[0427] Disabling the analog control circuit system may include disconnecting the voltage source of the circuit and / or bypassing the circuit, and / or short-circuiting the analog control circuit and / or disconnecting the analog control circuit from the corresponding heater.

[0428] When the equipment is controlling the heater of the conduit according to the first control scheme, the conduit pulse width modulation driver circuit system is disabled.

[0429] Disabling the conduit pulse width modulation driver circuit system may include disconnecting the voltage source and / or bypassing the circuit, and / or short-circuiting the circuit and / or disconnecting the circuit from the corresponding heater.

[0430] The device may include one or more power rail capacitors. Such power rail capacitors may be located at: a) the output terminal of the battery, b) the output terminal of the mains power supply, c) one or more of the output terminals of the battery or the output terminal of the mains power conversion circuit, or d) any combination of a) to c).

[0431] The frequency of the low-frequency pulse width modulation signal in the first control scheme can be less than about 20 Hz, or about 20 Hz to about 1 kHz.

[0432] The frequency of the high-frequency pulse width modulation signal in the second control scheme can be about 25 kHz, or about 1 kHz to about 50 kHz.

[0433] The frequency of a high-frequency pulse width modulation signal can be about 1250 times that of a low-frequency pulse width modulation signal.

[0434] The frequency of a high-frequency pulse width modulation signal can be about 50 times to about 2000 times the frequency of a low-frequency pulse width modulation signal.

[0435] The controller 13 can control the duty cycle of the pulse width modulation signal (or, as needed, the low-frequency pulse width modulation signal and / or the high-frequency pulse width modulation signal, i.e., in the example shown in Figures 5 and 5B).

[0436] The controller 13 can control the duty cycle of the pulse width modulation signal supplied to the heater of the humidifier.

[0437] Controller 13 can control the duty cycle of the pulse width modulation signal supplied to the heater of the conduit.

[0438] It should be understood that the duty cycle of a pulse width modulation signal can be controlled in any scheme using digital control.

[0439] The controller 13 can control the duty cycle of the pulse width modulation signal supplied to the heater of the duct independently of the duty cycle of the pulse width modulation signal supplied to the heater of the humidifier.

[0440] The controller 13 can control the duty cycle of the pulse width modulation signal (low frequency pulse width modulation signal and / or high frequency pulse width modulation signal, as needed) supplied to the heater and / or the heater of the duct of the humidifier according to the humidification control algorithm.

[0441] The humidification control algorithm may be the algorithm described in U.S. Patent Nos. 7,306,205 or 8,616,202, which are incorporated herein by reference.

[0442] The humidification control algorithm may include a control device to provide a therapeutic humidity level. In some configurations, the device may be configured to control the dew point to a therapeutic humidity level.

[0443] In some configurations, the device controller is configured to determine the desired temperature of the humidifier’s heater (e.g., heating plate) based on one or more of a flow sensor, a humidity sensor, and a temperature sensor located upstream of the humidification chamber.

[0444] The desired heating plate temperature can be used to control the power supplied to the heater of the humidifier based on the measured heating plate temperature.

[0445] In some configurations, the chamber outlet temperature sensor can also be used for closed-loop control of the heating plate power.

[0446] In some configurations, the device controller is configured to determine the desired chamber outlet temperature based on one or more of an ambient temperature sensor, a flow sensor, a heater of an optional humidifier temperature sensor, and an optional chamber outlet sensor.

[0447] The desired chamber outlet temperature can be used to control the power to the heating plate based on the measured chamber outlet temperature (e.g., measured by a chamber outlet sensor).

[0448] In some configurations, the heater catheter (e.g., a heating wire) can be controlled based on the tip of a catheter temperature sensor (e.g., a patient tip temperature sensor). The desired catheter tip temperature can be determined based on desired humidity (e.g., a therapeutic humidity level). In one example, the catheter tip temperature is controlled to be at least 3 degrees Celsius higher than the temperature of the gas exiting the chamber and / or the dew point of the gas exiting the chamber (e.g., measured by a chamber outlet temperature sensor). The catheter heater can be controlled to maintain the gas temperature above the dew point of the gas exiting the chamber.

[0449] In some configurations, the controller can be configured to control the power supplied to the heater of the humidifier. The controller can control the supplied power based at least on an ambient temperature sensor, a flow sensor, and, as needed, a humidifier temperature sensor for the heater, and further, as needed, a chamber outlet sensor.

[0450] The controller 13 can control the duty cycle of the pulse width modulation signal (low-frequency pulse width modulation signal and / or high-frequency pulse width modulation signal, as needed) supplied to the heater of the humidifier and / or the heater of the conduit based on one or more treatment parameters (e.g., treatment humidity level (e.g., relative humidity or absolute humidity, or dew point)). The controller can control the duty cycle to control the device to one or more treatment parameters.

[0451] The duty cycle of the pulse width modulation signal (low-frequency pulse width modulation signal and / or high-frequency pulse width modulation signal, if required) supplied to the heater of the humidifier can be based on the desired power of the heater of the humidifier. In some configurations, the desired power can be output by a controller to control the device to one or more treatment parameters as described elsewhere in the specification.

[0452] The controller 13 can control the duty cycle of the pulse width modulation signal supplied to the heater of the heater and / or humidifier of the catheter based on the desired temperature of the catheter tip (i.e., the patient tip) of the gas flow in the catheter.

[0453] The duty cycle of the pulse width modulation signal (low-frequency pulse width modulation signal and / or high-frequency pulse width modulation signal, if required) supplied to the heater of the catheter can be based on the desired power of the heater of the catheter. In some configurations, the desired power can be output by a controller to control the device to one or more treatment parameters as described elsewhere in the specification.

[0454] The controller is configured to measure the power supplied to the heater of the humidifier and control the duty cycle of the pulse width modulation signal (low-frequency pulse width modulation signal and / or high-frequency pulse width modulation signal, if necessary) based on the measured power supplied to the heater of the humidifier and the desired power of the heater of the humidifier.

[0455] The controller is configured to measure the power supplied to the heater of the catheter and control the duty cycle of the pulse width modulation signal (low-frequency pulse width modulation signal and / or high-frequency pulse width modulation signal, if necessary) based on the measured power supplied to the heater of the catheter and the desired power of the heater of the catheter.

[0456] The duty cycle of the pulse width modulation signal (low-frequency pulse width modulation signal and / or high-frequency pulse width modulation signal, if necessary) can be based on the desired temperature of the humidifier heater and / or the duct heater.

[0457] The desired power requirement and / or desired temperature may be based on one or more treatment parameters of the device.

[0458] The frequency of the pulse width modulation signal provided to the heater of the conduit by the second control scheme is less than about 20 Hz, or about 20 Hz to about 1 kHz (e.g., as a low frequency pulse width modulation signal).

[0459] As described elsewhere in the specification, the low-frequency pulse width modulation signal can be within a frequency range to minimize EMI generation while achieving the desired power output to the heater.

[0460] For example, as described above, controlling the heater of the conduit by analog control may include providing an analog control signal (e.g., a voltage signal) to the heater of the conduit. In some configurations, controlling the heater of the conduit by analog control includes providing current to the heater of the conduit.

[0461] The controller 13 can control analog control signals (e.g., voltage signals) supplied to the heater of the catheter and / or the heater of the humidifier based on one or more treatment parameters (e.g., the treatment temperature of the gas supplied to the user).

[0462] In some configurations, the voltage supplied to the heater of the duct and / or the heater of the humidifier is at least partially based on the resistance of the heater of the duct.

[0463] In some configurations, the heater of the conduit is primarily a resistive load. The heater of the conduit can have minimal parasitic capacitance and inductance.

[0464] The analog control signal (e.g., voltage signal) provided to the heater of the conduit can be controlled based on the desired power of the heater of the conduit.

[0465] The analog control signal (e.g., voltage signal) provided to the heater of the humidifier can be controlled based on the desired power of the heater of the humidifier.

[0466] The controller 13 can be configured to measure the power supplied to the heater of the catheter, and the analog control signal (e.g., voltage signal) supplied to the heater of the catheter is controlled based on the measured power supplied to the heater of the catheter and the desired power of the heater of the catheter.

[0467] The controller 13 can be configured to measure the power supplied to the heater of the humidifier, and the analog control signal (e.g., voltage signal) supplied to the heater of the humidifier is controlled based on the measured power supplied to the heater of the humidifier and the desired power of the heater of the humidifier.

[0468] The voltage signal supplied to the heater of the duct and / or the heater of the humidifier can be quadratically related to the input power (e.g., the measured power supplied to the heater duct), for example, because the heater of the duct and / or the heater of the humidifier is primarily a resistive load.

[0469] The analog control signal (e.g., voltage signal) of the heater provided to the catheter and / or the heater of the humidifier can be controlled based on the desired catheter tip (i.e., patient tip) temperature of the gas flow in the catheter.

[0470] The voltage signal supplied to the heater and / or humidifier of the duct can be controlled by one or more voltage converters.

[0471] A current signal (analog control via current modulation) can be provided to the heater of the duct and / or the heater of the humidifier via a current-mode controlled (CMC) buck converter.

[0472] It should be understood that a current signal (analog control by current modulation) can be provided to the heater of the duct and / or the heater of the humidifier by controlling one or more voltage converters based on the output of one or more current sensors.

[0473] The one or more voltage converters may include DC-DC converters.

[0474] The voltage converter can be a voltage-mode controlled (VMC) buck converter.

[0475] In some configurations, the one or more voltage converters may include: a) a buck converter b) a DC-DC converter c) a boost converter d) a boost converter e) a half-bridge converter f) a flyback converter g) a push-pull converter h) a switching converter i) a switching regulator j) a linear regulator k) a linear converter l) a buck converter m) a transformer n) any combination of a) to m)

[0476] The voltage converter may be an analog control circuit system or a part thereof. [Simplified Explanation of the Diagram]

[0125] Specific embodiments and modifications thereof will become clear to those skilled in the art by referring to the following figures, in accordance with the detailed description herein, in which:

[0126] [Figure 1] shows a respiratory assist device in schematic form.

[0127] [Figures 2, 2A and 2B] show a perspective view of a respiratory assist device.

[0128] [Figure 3] is a rear-view stereoscopic view of a respiratory assist device.

[0129] [Figures 4 and 4A] are schematic diagrams of a device including heater control.

[0130] [Figure 5 and Figure 5A] are schematic diagrams of the control of the humidifier heater and the duct heater.

[0131] [Figure 5B] shows a schematic diagram of the conversion circuit of the device.

[0132] [Figure 6] is a schematic diagram of gas flow path for filter modules and valve modules, where solid arrows represent gas flow.

[0133] [Figures 7A and 7B] show examples of pulse width modulation signals.

[0134] [Figures 7C to 7E] show an example of a voltage signal as an analog control signal.

[0135] [Figures 8 and 9] show schematic diagrams of the control of the device when it is initially powered by a battery.

Claims

1. A respiratory assist device, comprising: A humidifier configured to be pneumatically connected to a flow generator and to humidify a gas flow generated by the flow generator, wherein the humidifier includes a heater, wherein the device is configured to be connected to a duct conveying the gas flow, wherein the duct includes a heater configured to heat the gas flow within the duct, a battery, wherein the device is configured to be powered by the battery or mains power, and a controller configured to control the heater of the duct and the heater of the humidifier according to at least a first control scheme and a second control scheme. When the device is powered by the battery, the controller is configured to control the heater of the duct and the heater of the humidifier according to a first control scheme, the first control scheme including controlling the heater of the duct by analog control and providing a high-frequency pulse width modulation signal to the heater of the humidifier, and wherein when the device is powered by mains power, the controller is configured to control the heater of the duct and the heater of the humidifier according to a second control scheme, the second control scheme including controlling the heater of the duct by providing a pulse width modulation signal by digital control and providing a low-frequency pulse width modulation signal to the heater of the humidifier, and wherein the frequency of the high-frequency pulse width modulation signal is greater than the frequency of the low-frequency pulse width modulation signal.

2. The respiratory assist device as described in claim 1, wherein, The heater of the humidifier includes a heating plate, which is configured to heat the fluid in the humidification chamber to humidify the gas flow.

3. The respiratory assist device as described in claim 2, wherein, The heater of the humidifier includes a conductive heating element.

4. The respiratory assist device as described in claim 3, wherein, The heater for the conduit includes a heating wire.

5. The respiratory assist device as described in claim 4, wherein, The heating wire is: a) in the lumen of the conduit, b) within the wall of the conduit, c) embedded in the wall of the conduit, d) embedded in the beaded edge forming the breathing conduit, the beaded edge being configured as needed to provide structural support to the conduit, e) located on the outer surface of the conduit, f) any combination of a) to e).

6. The respiratory assist device as described in claim 1, wherein, The device includes a flow generator configured to generate the gas flow.

7. The respiratory assist device as described in claim 1, wherein, The device is configured to detect whether it operates on battery power or AC power.

8. The respiratory assist device as described in claim 7, wherein, The device is configured to operate on battery power when no mains power is detected.

9. The respiratory assist device as described in claim 1, wherein, The device is configured to operate on battery power based on user input.

10. The respiratory assist device as described in claim 9, wherein, The device is configured to operate on battery power via a user interface based on input from the user.

11. The respiratory assist device as described in claim 1, wherein, The battery is located in the device.

12. The respiratory assist device as described in claim 1, wherein, The battery is located inside the device's casing.

13. The respiratory assist device as described in claim 1, wherein, The device includes at least one battery as part of a battery module.

14. The respiratory assist device as described in claim 1, wherein, The battery is configured to connect to and disconnect from the device.

15. The respiratory assist device as described in claim 14, wherein, The battery is configured to be able to connect and disconnect from the device's housing.

16. The respiratory assist device as described in claim 1, wherein, The device includes one or more power rail capacitors.

17. The respiratory assist device as described in claim 16, wherein, The power supply rail capacitors are configured to be located at: a) the output terminal of the battery, b) the output terminal of the mains power supply, c) one or more of the output terminals of the battery or the mains power conversion circuit, or d) any combination of a) to c).

18. The respiratory assist device as described in any one of claims 1 to 17, wherein, The device includes a digital control circuit system configured to generate a pulse width modulation signal for a heater of the conduit, and / or the high-frequency pulse width modulation signal and / or the low-frequency pulse width modulation signal.

19. The respiratory assist device as described in claim 18, wherein, The digital control circuit system includes one or more switching circuits and / or one or more pulse width modulation drivers.

20. The respiratory assist device as described in claim 18, wherein, The digital control circuit system includes a pulse width modulation driver for the heater of the humidifier, the pulse width modulation driver being configured to generate the high-frequency pulse width modulation signal and the low-frequency pulse width modulation signal.

21. The respiratory assist device as described in claim 18, wherein, The digital control circuit system includes a pulse width modulation driver for the heater of the conduit, the pulse width modulation driver being configured to generate the pulse width modulation signal.

22. The respiratory assist device as described in claim 18, wherein, When the device is controlling the heater of the conduit according to the first control scheme, the heater of the conduit pulse width modulation driver is disabled.

23. The respiratory assist device as described in claim 1, wherein, The device includes a housing, and the flow generator and / or humidifier is located within the housing.

24. The respiratory assist device as described in claim 1, wherein, The device includes a gas inlet and a gas outlet, wherein the conduit is configured to be connected to the gas outlet.

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