Vent arrangement for respiratory mask

• US 10,029,058 B2
• Filed: 09/13/2012
• Issued: 07/24/2018
• Est. Priority Date: 09/13/2011
• Status: Active Grant

• Current Assignee: ResMed Pty Ltd. (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Foote, Roger Mervyn Lloyd, Huby, Ronald James, Dantanarayana, Muditha Pradeep, Mazzone, Damien Julian, Martin, Dion Charles Chewe, Armitstead, Jeffrey Peter, Formica, Justin John, Tang, Zhuo Ran, Cohen, Lance Steven, Vandyke, James William Charles, Sears, David Brent, Nagorny, Aleksandr S., Sampietro, Joe, Farrugia, Steven Paul
• Primary Examiner(s): Philips, Bradley
• Application Number:
  US14/342,972
• Publication Number:
  US 20140283831A1
• Time in Patent Office: 2,140 Days
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/091 Measuring volume of inspired or expired gases, e.g. to determine lung capacity
• CPC Class Codes: A61B 5/4809 Sleep detection, i.e. determining whether a subject is asleep or not
• CPC Class Codes: A61B 5/4812 Detecting sleep stages or cycles
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61M 16/0045 Means for re-breathing exhaled gases, e.g. for hyperventilation treatment
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/009 Removing used or expired gases or anaesthetic vapours filtering, sterilising or disinfecting the exhaust air in drainage systems A61M1/784; bacterial filters in the expiratory path A61M16/1065
• CPC Class Codes: A61M 16/026 specially adapted for predicting, e.g. for determining an information representative of a flow limitation during a ventilation cycle by using a root square technique or a regression analysis
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0666 Nasal cannulas or tubing devices for improving normal breathing through the nose A61F5/08; nose filters A62B23/06; outside holding devices A61M25/02
• CPC Class Codes: A61M 16/0816 Joints or connectors
• CPC Class Codes: A61M 16/0875 Connecting tubes
• CPC Class Codes: A61M 16/1095 in the connecting tubes
• CPC Class Codes: A61M 16/20 Valves specially adapted to medical respiratory devices
• CPC Class Codes: A61M 16/202 electrically actuated
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/003 with a flowmeter
• CPC Class Codes: A61M 2202/0085 : product washed out
• CPC Class Codes: A61M 2202/0225 : Carbon oxides, e.g. Carbon dioxide
• CPC Class Codes: A61M 2205/15 : Detection of leaks
• CPC Class Codes: A61M 2205/3331 : Pressure; Flow
• CPC Class Codes: A61M 2205/3334 : Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/3368 : Temperature
• CPC Class Codes: A61M 2205/42 : Reducing noise
• CPC Class Codes: A61M 2205/50 : with microprocessors or computers
• CPC Class Codes: A61M 2230/005 : Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/202 : partial carbon oxide pressure, e.g. partial dioxide pressure (P-CO2)

Abstract

A control system (706) provides automated control of gas washout of a patient interface, such as a mask or nasal prongs. A gas washout vent assembly (60) of the system may include a variable exhaust area such as one defined by overlapping apertures of the assembly or a conduit having a variable gas passage channel. The vent assembly may be formed by nested structures, such as conic or cylindrical members, each having an opening of the overlapping apertures. The vent assembly may be attached substantially near or included with the patient interface. An actuator of the assembly, such as a solenoid or voice coil, manipulates an aperture of the vent assembly. The actuator may be configured for control by a controller to change the exhaust area of the vent assembly based on various methodologies including, for example, sleep detection, disordered breathing event detection, rebreathing volume calculation and/or leak detection.

Claims

1. An apparatus for automated control of gas washout of a non-invasive patient interface of a respiratory treatment apparatus comprising:

a vent assembly having a variable exhaust area defined by one or more apertures of the vent assembly, the vent assembly being (1) associated with the non-invasive patient interface to vent expiratory gas and (2) proximal to the non-invasive patient interface;

an actuator to manipulate said one or more apertures of the vent assembly; and

a controller, including a processor, that is coupled to the actuator and configured to operate the actuator to change the variable exhaust area of the vent assembly,

wherein the variable exhaust area is configured to be set to a plurality of open positions, the plurality of open positions providing different vent flow areas that are adapted to provide an increase or decrease in flow rate of the expiratory gas through the variable exhaust area.

2. The apparatus of claim 1 wherein the controller is configured to switch between a treatment setting for the variable exhaust area and a comfort setting for the variable exhaust area.

3. The apparatus of claim 1 wherein the controller is configured with a user interface for input of comfort settings including a setting for the variable exhaust area, wherein the comfort setting includes one or more of a humidity setting, pressure setting, and a temperature setting.

4. The apparatus of claim 1 wherein the controller is configured to determine a measure of patient ventilation and adjust the variable exhaust area as a function of the measure of patient ventilation and the variable exhaust area is decreased if the measure of patient ventilation meets or exceeds a threshold, wherein the measure of patient ventilation comprises an instability index.

5. The apparatus of claim 4 wherein the instability index comprises at least one of a moving window standard-deviation of ventilation, a central apnoea index, a central hypopnoea index, a central apnoea-hypopnoea index, an persistent apnoea-hypopnoea index, and a respiratory disturbance index.

6. The apparatus of claim 1 wherein the controller is configured to detect a Cheyne-Stokes respiration cycle from a patient flow signal and phase-lock adjustments to the variable exhaust area to control rebreathing cycles according to the phase-lock.

7. The apparatus of claim 1 wherein the controller is further configured to control operation of a flow generator.

8. The apparatus of claim 1 wherein the controller is configured to detect a presence or absence of an unintentional leak and control the change to the exhaust area based on the detection of the presence or absence of the unintentional leak.

9. The apparatus of claim 8 wherein the controller closes the exhaust area in response to the detection of the presence of the unintentional leak.

10. The apparatus of claim 8 wherein the controller closes and opens the exhaust area in response to a continued detection of the presence of the unintentional leak.

11. The apparatus of claim 8 wherein the controller changes the exhaust area as a function of a quantification of the unintentional leak.

12. The apparatus of claim 11 wherein the controller decreases the exhaust area based on a threshold comparison of a value of the quantification.

13. The apparatus of claim 1 wherein the controller is configured to detect a sleep state and control the change to the exhaust area based on the detection of the sleep state.

14. The apparatus of claim 13 wherein the controller initiates a cyclical variation of the exhaust area in response to the detection of the sleep state.

15. The apparatus of claim 13 wherein the controller maintains an approximately constant exhaust area in response to the detection of an absence of sleep.

16. The apparatus of claim 1 wherein the controller is configured to detect a breathing condition and control the change to the exhaust area based on the detection of the breathing condition.

17. The apparatus of claim 16 wherein the detected breathing condition comprises a central apnea or central hypopnea and the controller is configured to control a decrease to the exhaust area based on the detection of the central apnea or central hypopnea.

18. The apparatus of claim 17 wherein the controller is configured to control an increase of the exhaust area based on a further detection of an absence of central apnea or central hypopnea.

19. The apparatus of claim 1 wherein the controller controls changes to the exhaust area in synchrony with detected patient respiration and the controller controls changes to the variable exhaust area as a function of any one of a measure of pressure;

a measure of flow through the variable exhaust area;

a measure of patient flow;

or a calculation of a rebreathed volume.

20. The apparatus of claim 1 wherein the actuator comprises a motor and an induction coil coupled to a first structure and a second structure, and wherein the structures are configured to adapt a size of overlapping apertures by rotation of the first structure.

21. The apparatus of claim 1 wherein the actuator comprises one or more of a voice coil;

a magnet;

a pneumatic piston;

a motor;

or a piezo motor.

22. The apparatus of claim 1 further comprising a spring mechanism configured to return the variable exhaust area of the vent assembly to a normally open position.

23. The apparatus of claim 1 wherein the variable exhaust area is defined by overlapping apertures.

24. A system for automated control of gas washout of a non-invasive patient interface comprising:

a vent assembly having a variable exhaust area defined by one or more apertures of the vent assembly, the vent assembly being (1) attachable to the non-invasive patient interface and (2) proximal to the non-invasive patient interface; and

an actuator to manipulate an aperture of the vent assembly, the actuator configured for control by a controller to change the exhaust area of the vent assembly,

wherein the variable exhaust area is configured to be set to a plurality of open positions, the plurality of open positions providing different vent flow areas that are adapted to provide an increase or decrease in flow rate of expiratory gas through the variable exhaust area.

25. The system of claim 24 wherein the actuator comprises a motor and an induction coil coupled to a first structure and a second structure, and wherein the structures are configured to change a size of overlapping apertures by rotation of the first structure.

26. The system of claim 24 wherein the actuator comprises at least one of a voice coil;

a pneumatic piston;

an induction coil;

or a piezo motor.

27. The system of claim 24 further comprising a spring mechanism configured to return the variable exhaust area of the vent assembly to a normally open position.

28. The system of claim 24 wherein the controller is configured to detect a presence or absence of an unintentional leak and control the change to the exhaust area based on the detection of the presence or absence of the unintentional leak.

29. The system of claim 28 wherein the controller closes the exhaust area in response to the detection of the presence of the unintentional leak.

30. The system of claim 28 wherein the controller opens the exhaust area in response to the detection of the presence of the unintentional leak to lower a mask pressure to ambient pressure.

31. The system of claim 28 wherein the controller closes and opens the exhaust area in response to a continued detection of the presence of the unintentional leak.

32. The system of claim 28 wherein the controller changes the exhaust area as a function of a quantification of the unintentional leak.

33. The system of claim 32 wherein the controller decreases the exhaust area based on a threshold comparison of a value of the quantification.

34. The system of claim 24 wherein the controller is configured to detect a sleep state and control the change to the exhaust area based on the detection of the sleep state.

35. The system of claim 34 wherein the controller initiates a cyclical variation of the exhaust area as a function of a detected sleep state.

36. The system of claim 34 wherein the controller maintains an approximately constant exhaust area in response to the detection of an absence of sleep.

37. The system of claim 24 wherein the controller is configured to detect a breathing condition and control the change to the exhaust area based on the detection of the breathing condition.

38. The system of claim 37 wherein the detected breathing condition comprises a central apnea or central hypopnea and the controller is configured to control a decrease to the exhaust area based on the detection of the central apnea or central hypopnea.

39. The system of claim 38 wherein the controller is configured to control an increase of the exhaust area based on a further detection of an absence of central apnea or central hypopnea.

40. The system of claim 24 wherein the controller controls changes to the exhaust area as a function of a measure of patient flow.

41. The system of claim 24 wherein the controller controls changes to the exhaust area as a function of a calculation of a rebreathed volume.

42. The system of claim 24 wherein the controller controls changes to the exhaust area in synchrony with detected patient respiration to permit a vent flow of the exhaust area to mirror patient flow.

43. The system of claim 24 wherein the controller is configured to switch between a treatment setting for the variable exhaust area and a comfort setting for the variable exhaust area.

44. The system of claim 24 wherein the controller is configured with a user interface for input of comfort settings including a setting for the variable exhaust area, wherein the comfort setting includes one or more of a humidity setting, pressure setting, and a temperature setting.

45. The system of claim 24 wherein the controller is configured to determine a measure of patient ventilation and adjust the variable exhaust area as a function of the measure of patient ventilation, wherein the measure of patient ventilation comprises an instability index.

46. The system of claim 45 wherein the variable exhaust area is decreased if the measure of patient ventilation meets or exceeds a threshold.

47. The system of claim 45 wherein the instability index comprises at least one of a moving window standard-deviation of ventilation, a central apnoea index, a central hypopnoea index, a central apnoea-hypopnoea index, an persistent apnoea-hypopnoea index, and a respiratory disturbance index.

48. The system of claim 24 wherein the controller is configured to detect a Cheyne-Stokes respiration cycle from a patient flow signal and phase-lock adjustments to the variable exhaust area to control rebreathing cycles according to the phase-lock.

49. The system of claim 24 wherein the variable exhaust area is defined by overlapping apertures.