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EP-4445935-B1 - SYSTEMS FOR CONTROLLING OXYGEN DELIVERY IN A FLOW THERAPY APPARATUS

EP4445935B1EP 4445935 B1EP4445935 B1EP 4445935B1EP-4445935-B1

Inventors

  • BURGESS, Russel William
  • EDWARDS, Bryn Alan
  • GULLEY, Anton Kim
  • CRONE, CHRISTOPHER MALCOLM

Dates

Publication Date
20260513
Application Date
20200910

Claims (13)

  1. A respiratory apparatus (10) that provides a flow of gases to a patient, the respiratory apparatus (10) comprising: an ambient air inlet (27); a supplemental inlet (28) for receiving supplemental gases from a supplemental gases source; a valve configured to control a flow rate of the supplemental gases received through the supplemental gases inlet (28); a gases composition sensor configured to measure gases composition of mixed flow of ambient air and supplemental gases; a controller (13) configured to control delivery of gases to the patient, the controller configured to: adjust actuation of the valve by controlling a valve current; determine a target supplemental gases flow rate; set the valve current based on the target supplemental gases flow rate using a valve model; and update valve model over time based in part on measurements received from the gases composition sensor, characterized in that the valve model is updated over time based in part on predicted changes in the measured gases composition, wherein the predicted changes in the measured gases composition are based at least in part on the recent trend in measured gases composition.
  2. The respiratory apparatus (10) of Claim 1, wherein the supplemental gases comprise concentrated oxygen; and/or wherein the measurement of gases composition is a measured fraction of delivered oxygen (FdO2).
  3. The respiratory apparatus (10) of any of Claims 1 or 2, wherein the predicted changes in the measured gases composition are based at least in part on a current valve position and a current flow rate of the supplemental gases.
  4. The respiratory apparatus (10) of any of Claims 1-3, wherein the valve model is updated over time based in part on a target gases composition.
  5. The respiratory apparatus (10) of Claim 4, wherein the target gases composition is a target FdO2.
  6. The respiratory apparatus (10) of any of Claims 1-5, wherein the valve model includes an estimate of a minimum current required to open the valve; and wherein the estimate of the minimum current required to open the valve is updated over time.
  7. The respiratory apparatus (10) of any of Claims 1-6, further comprises a flow rate sensor configured to measure a total flow rate.
  8. The respiratory apparatus (10) of Claim 7, wherein the controller (13) determines the target supplemental gases flow rate based at least in part on the total flow rate.
  9. The respiratory apparatus (10) of any of Claims 1-8, wherein the controller (13) determines the target supplemental gases flow rate based at least in part on target FdO2; and/or wherein the controller (13) determines the target supplemental gases flow rate based at least in part on the fraction of oxygen of the ambient air; and/or wherein the controller (13) determines the target supplemental gases flow rate based at least in part on the fraction of oxygen of the supplemental gas source.
  10. The respiratory apparatus (10) of any of Claims 1-9, wherein the controller (13) updates the valve model at different rates depending on expected respiration rate ranges.
  11. The respiratory apparatus (10) of any of Claims 1-10, wherein the controller (13) updates the valve model at different rates depending on expected amplitudes of flow rate oscillations.
  12. The respiratory apparatus (10) of any of Claims 1-11, wherein the controller (13) updates the valve model at different rates depending on the flow rate.
  13. The respiratory apparatus (10) of any of Claims 1-12, wherein the valve model includes an estimate of the flow rate of the supplemental gases through the valve.

Description

FIELD OF THE DISCLOSURE The present disclosure relates to methods and systems for controlling oxygen delivery in a flow therapy apparatus. BACKGROUND Respiratory apparatuses are used in various environments such as hospital, medical facility, residential care, or home environments to deliver a flow of gas to users or patients. A respiratory apparatus, or a flow therapy apparatus, may include an oxygen inlet to allow delivery of supplemental oxygen with the flow of gas, and/or a humidification apparatus to deliver heated and humidified gases. A flow therapy apparatus may allow adjustment and control over characteristics of the gases flow, including flow rate, temperature, gas concentration, such as oxygen concentration, humidity, pressure, etc. WO 2019/112447 A1 discloses a graphical user interfaces for controlling a flow therapy apparatus. The graphical user interface can provide a display of flow therapy treatment information and indicators of a patient's health. The graphical user interface can be configured to display the information associated with the patient on one or more user interface screens. SUMMARY The invention is defined by the appended claims. In accordance with certain features, aspects and advantages of a first embodiment disclosed herein, a respiratory apparatus that provides a flow of gases to a patient, the respiratory apparatus comprising: an ambient air inlet; a supplemental inlet for receiving supplemental gases from a supplemental gases source; a valve configured to control a flow rate of the supplemental gases received through the supplemental gases inlet; a flow rate sensor configured to measure a total flow rate of gases delivered to the patient; a controller configured to control delivery of gases to the patient, the controller configured to: determine a target supplemental gases flow rate based at least in part on the total flow rate; and set a valve current based on the target supplemental gases flow rate. In some configurations of the first embodiment, the supplemental gases comprise concentrated oxygen. In some configurations of the first embodiment, the controller is configured to determine the target supplemental gases flow rate based at least in part on a target fraction of delivered oxygen (FdO2). In some configurations of the first embodiment, the controller is configured to determine the target supplemental gases flow rate based at least in part on a fraction of oxygen of ambient air. In some configurations of the first embodiment, the controller is configured to determine the target supplemental gases flow rate based at least in part on a fraction of oxygen of the supplemental gas source. In some configurations of the first embodiment, the controller is configured to set the valve current based on the target supplemental gas flow using a valve model. In some configurations of the first embodiment, the valve model is updated over time. In some configurations of the first embodiment, the valve model is updated based in part on the measured FdO2. In some configurations of the first embodiment, the valve model is updated based in part on the total flow rate. In some configurations of the first embodiment, the valve model is updated based in part on a target FdO2. In some configurations of the first embodiment, the valve model includes an estimate of a minimum current required to open the valve. In some configurations of the first embodiment, the estimate of the minimum current required to open the valve is updated over time. In some configurations of the first embodiment, the valve model includes an estimate of the flow rate of the supplemental gases through the valve. In some configurations of the first embodiment, the estimate of the flow rate of the supplemental gases through the valve is determined using at least one of a first order model, an advection diffusion equation, a naiver stokes equation, or machine learning algorithms. In accordance with certain features, aspects and advantages of a second embodiment disclosed herein, a respiratory apparatus that provides a flow of gases to a patient, the respiratory apparatus comprising: an ambient air inlet; a supplemental inlet for receiving supplemental gases from a supplemental gases source; a valve configured to control a flow rate of the supplemental gases received through the supplemental gases inlet; a gases composition sensor configured to measure gases composition of mixed flow of ambient air and supplemental gases; a controller configured to control delivery of gases to the patient, the controller configured to: adjust actuation of the valve by controlling a valve current; determine a target supplemental gases flow rate; set the valve current based on the target supplemental gases flow rate using a valve model; and update valve model over time based in part on measurements received from the gases composition sensor. In some configurations of the second embodiment, the supplemental gases comprise concentrated oxyg