JPWO2020204731A5 - - Google Patents

Description

1 and 1A show schematic diagrams of an exemplary dual rim humidification system 1. FIG. Humidification system 1 may include gas source 10 in fluid communication with humidifier 20 via dry line conduit 30 . In this disclosure, an example gas source is a ventilator. Other gas sources, such as wall gas sources or compressed gas tanks, are also conceivable. The dry line conduit 30 may be a tube shaped and configured to transport gas from the gas source to the humidifier 20 . "Dry line conduit refers to a conduit (e.g., tube or serpentine) used to transport non-humidified (e.g., dry or atmospheric) gas from a gas source to the humidifier 20. configuration), the dry line conduit provides a pneumatic connection between the gas source and the humidifier 20. The humidifier 20 can be in various configurations including, for example, a chamber 26 (see FIG. 1A) and a heat source. The heat source may include a humidifier heat source The humidifier heat source is used to heat the contents of the chamber 26 so that the gas flowing through the chamber may be humidified by the vaporized contents, Vaporize the contents of 26. In one example, a heat source is used to heat water, vaporize it, and humidify the gas, which heats the gas passing through chamber 26 to a desired temperature (e.g., treatment temperature). Examples of humidifier heat sources can include chemical heaters, radiant heaters, induction heaters, etc. As an example, the heat source can be a heater plate using a resistance heater. Optionally, it may also include one or more processors, such as hardware processors and/or software processors.Humidifier 20 may include a controller, which may include one or more processors and memory. 20, such as the steady state operation of the humidifier 20. The gas source may be a unidirectional gas source, a blower, a ventilator unit, a compressed air tank, a hospital wall gas source, an oxygen cylinder or pressurized gas. Several gas sources may provide and remove gas from the patient, particularly when the patient is sedated to facilitate breathing and gas exchange within the patient. These systems generally require inspiratory and expiratory conduits, and the gas source is configured to deliver high flow rates of air or gas, e.g., greater than 30 L/min and/or up to 150 L/min. The gas source may also be configured to deliver other ranges of gas flow rates, for example, for neonatal applications, the flow rate may be less than 8 L/min. The gas supplied can include any of dry air, ambient air, oxygen and/or mixtures of gases (e.g., therapeutic gases or respiratory gases) One or more controllers control the desired flow rate, temperature and/or pressure. The gas source 10 can be controlled to generate a gas flow of The gas from the gas source outlet 12 can include dry gas.

In error 1 as shown in FIG. 2A, the connections between the dry line conduit 30 and expiratory conduit 50 and the gas source 10 are reversed. Specifically, dry line conduit 30 is miscoupled to gas source inlet 14 and expiratory conduit 50 is miscoupled to gas source outlet 12 . As a result, since the dry gas does not pass through the humidifier 20, the dry gas can flow directly to the patient 2 in the expiratory conduit 50 without being humidified or heated. The dry gas may be heated by an expiratory heat source within the expiratory conduit 50 whose heating is not properly regulated by the controller. Exhaled gases from patient 2 may be humidified through humidifier 30 before returning to gas source 10 . As a result, condensation forms within the gas source 10 .

Both downstream and upstream humidity of the humidifier can be used to determine if there is erroneous flow in the humidification system. Humidity can be generated when the heater plate is powered, resulting in an increase in water temperature. Humidity can also be generated when dry gas is passed over water in a humidifier. In method 380 shown in FIG. 3D, the humidification system controller can initiate a backflow detection algorithm. In step 384, the humidification system controller determines the downstream humidity of the humidifier using the downstream humidity sensor and the upstream humidity of the humidifier using the upstream humidity sensor . At step 386, the controller determines if the upstream humidity is lower than the downstream humidity. If the upstream humidity is higher than the downstream humidity, the humidification system controller may determine at step 388 that there is erroneous flow. Conversely, the controller may determine in step 390 that there is no erroneous flow if the upstream humidity is lower than the downstream humidity as expected. When the controller detects an erroneous flow condition, the controller can generate an indication that a erroneous connection exists. The presence of erroneous flow conditions may indicate a misconnection.

As shown in FIG. 7, a humidification system may include a gas source (also called a ventilator) 10 in fluid communication with a humidifier 20 via a dryline conduit 30. As shown in FIG. Humidifier 20 may include various components including, for example, a chamber and a heat source. Humidifier 20 may optionally also include one or more processors, such as hardware processors and/or software processors. Humidifier 20 may include a controller that may include one or more processors and memory. A controller can control the operation of the humidifier 20 . The humidified gas can exit humidifier 20 and enter inspiratory conduit 40 . An inspiratory conduit 40 (ie, gas delivery conduit) can provide humidified gas to the patient 2 . The patient interface may also include an interface tube, which is a short section of unheated tubing, and the inspiratory conduit 40 may be coupled or connected to the interface tube. Optionally, intake conduit 40 may include a heater. Humidification system 1 may include an exhalation conduit 50 . Expiration conduit 50 may be a gas transport conduit that directs gas away from patient 2 . The expiratory conduit 50 may direct the expiratory gases away from the patient and transport the expiratory gases to the gas source (or to some other device (eg, vent) that can release the gases to the atmosphere). The expiratory conduit 50 can redirect gas exhaled by the patient 2 to the gas source inlet.

FIG. 12A shows exemplary first and second positions of pressure sensing devices 1202, 1204. FIG. Exemplary positions are shown as solid dots. The pressure sensing device may be placed in the humidifier or humidification chamber just before the entrance of the outlet and/or in the inlet of the humidifier or humidification chamber. In this case, the pressure sensing device near the outlet may have a larger cross-sectional area than the pressure sensing device at the inlet. An inlet pressure sensor 1202 is associated with the inlet (or inlet port) of the chamber and an outlet pressure sensor 1204 is associated with the outlet of the chamber. In the illustration of FIG. 12A, inlet pressure sensor 1202 is at the inlet (ie, inlet port) of chamber 1200 . As shown in FIG. 12A, the outlet pressure sensor 1204 is located external to the outlet (ie, outlet port), but adjacent to the outlet. At step 1126, the controller can compare the first pressure reading to the second pressure reading (ie, compare the reading of inlet pressure sensor 1202 and the reading of outlet pressure sensor 1204). If the pressure measured at inlet pressure sensor 1202 exceeds the pressure measured at outlet pressure sensor 1204 , the method proceeds to step 1128 . If the pressure measured by outlet pressure sensor 1204 is greater than the pressure measured by inlet pressure sensor 1202 (ie, inlet pressure is less than outlet pressure), the method proceeds to step 1130 . If a backflow condition is detected by step 1130, this indicates a misconnection. The controller may send a signal or message to a user interface (eg, humidifier screen or gas source screen) to present a message or alarm to the user.

FIG. 18B shows an exemplary humidification chamber 20 of the humidification system disclosed herein. Humidification chamber 20 may include a sensor (or sensors) 1822 at or near chamber inlet 22 . One or more sensors may or may not be in direct contact with the gas stream. In some configurations, one or more sensors may or may not be in direct contact with the humidification chamber of humidifier 20 . In some configurations, one or more sensors may be housed within humidifier 20 . As described above, the one or more sensors 1822 can measure parameters associated with the formation of condensation on the inner surface of the chamber inlet 22 near the humidification chamber 20 or on the sidewalls of the humidification chamber 20 . Alternatively, the chamber may include a deflection assembly configured to deflect the incoming gas to a region of the side wall of the humidification chamber. The sensor may be configured to detect parameters in that area (regardless of gas direction). The sensor 1822 and configuration shown in FIG. 18B can be used to perform the method 1850. FIG. Method 1850 may be performed by a humidifier, which may be humidifier 20, and/or a controller of gas source 10. FIG.

Claims (15)

A method for detecting reflux conditions in a respiratory humidification system including a gas source, a humidifier, and a breathing circuit, the humidifier including a base including a heater plate and a humidification chamber holding a humidified fluid. , the humidification chamber is positionable on the base, the breathing circuit includes an inspiratory conduit, an expiratory conduit and a dry line;
The method includes:
introducing a flow of gas into the inlet of the humidification chamber;
directing a flow of gas through a flow guide coupled to the inlet toward a concentrated area of the moistened fluid surface;
sensing changes in the surface of the humidifying fluid ;
outputting an indication of a reverse flow condition based on sensing a change in the humidified fluid surface ;
A method, including 2. The method of claim 1, wherein the concentrated area of the surface of the humidifying fluid is directly below the inlet of the humidifying chamber. 3. A method according to claim 1 or 2, wherein the flow guide comprises an elongated tube extending into the humidification chamber and directing the gas flow over the concentration region. Sensing a change in the surface includes measuring a temperature of a surface of water below or adjacent to the inlet of the humidification chamber, wherein a temperature in the concentration region above a threshold temperature indicates a backflow condition. 4. A method according to any one of claims 1 to 3, wherein the method is indicative of 5. The method of claim 4, wherein sensing changes in the surface of the water comprises comparing the temperature of the area of concentration to the temperature of another area of the surface of the water remote from the area of concentration. 6. A method according to any one of claims 1 to 5, wherein the sensing comprises monitoring the surface contour of water in the humidification chamber. monitoring the contour of the surface of the water includes monitoring a water level at a first location and a water level at a second location, wherein a difference in water level between the first location and the second location exceeds a threshold; 7. The method of claim 6, wherein absence indicates a reflux condition. 8. The method of claim 7, wherein the first position is proximate the inlet of the humidification chamber and the second position is proximate the outlet of the humidification chamber. 9. Method according to claim 7 or 8, wherein a preliminary step of setting the reference water level at the first position and/or the second position is performed in the absence of gas flow. 10. A method according to any one of claims 6 to 9, wherein monitoring of the contour of the surface of the water is done by optical sensors. 6. A method according to any one of the preceding claims, wherein said sensing comprises sensing a pattern of ripples on the surface of said water. The controller is configured to detect ripples by comparing a detected ripple pattern to a predetermined ripple pattern and/or classifying the ripple pattern using image or pattern recognition techniques. 12. The method of claim 11, wherein 13. The method of claim 11 or 12, wherein detection of the ripple pattern indicates a normal flow condition and non-detection of the ripple pattern indicates a reverse flow condition. 14. A method according to any one of claims 11 to 13, wherein monitoring of the ripple pattern is performed by an optical sensor. The respiratory humidification system is configured to provide respiratory therapy to a patient, the respiratory humidification system comprising:
a user interface;
a first breathing circuit configured to connect a gas source and the humidification chamber;
A second breathing circuit configured to connect the gas source and the patient, wherein the first breathing circuit is configured to be upstream of the second breathing circuit under normal flow conditions. the second breathing circuit,
a backflow indicator in the gas flow path of the system, said backflow indicator in a first configuration during normal flow and in a second configuration different from said first configuration during backflow;
15. The method of any one of claims 1-14, further comprising :

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