System and a method for delivering breathing gas to passengers on-board an aircraft

1. A system for delivering breathing gas to passengers on-board an aircraft, comprising:

a source of breathing gas,

a face mask for passengers,

a reservoir associated with the face mask,

a delivery valve each connected with the face mask, the delivery valve being disposed between the source of breathing gas and the reservoir, the reservoir being disposed between the delivery valve and the face mask,

a sensor associated with the reservoir and configured to produce an electrical signal based upon a filling of the reservoir,

a controller configured to control the delivery valve in a continuous supply mode to provide a continuous flow of breathing gas to the reservoir and to interrupt the continuous flow of breathing gas when the filling sensed by the sensor is a filling threshold, and

wherein the face mask is positioned downstream from the source of breathing gas, and the face mask is downstream from the reservoir, such that the breathing gas that exits the source of breathing gas and the delivery valve would enter the reservoir before the breathing gas enters the face mask.

2. The system according to claim 1 wherein:

the continuous supply mode is a first continuous supply mode,

the controller is configured to adjust the flow of breathing gas in a second continuous supply mode higher than in the first continuous supply mode.

3. The system according to claim 2 wherein the controller is configured to switch between the first continuous supply mode and the second continuous supply mode based on a second parameter, the second parameter including presence of toxic gas and/or fumes in ambient gas.

4. The system according to claim 2 wherein:

the controller is configured to adjust the flow of breathing gas in the first continuous supply mode between a low flow and a high flow, and

the controller is configured to adjust the flow of breathing gas in the second continuous supply mode higher or equal to the high flow.

5. The system according to claim 2 wherein the controller is configured to set the flow of breathing gas at a predetermined flow in the second continuous supply mode.

6. The system according to claim 2 wherein the delivery valve is of on/off valve and the controller is configured to control the delivery valve in Pulse Modulation mode in the first continuous supply mode, and the controller is configured to maintain the delivery valve open in the second continuous supply mode.

7. The system according to claim 2 wherein the system further comprises a regulator configured to be controlled by the controller to adjust the flow of breathing gas in the first continuous supply mode and in the second continuous supply mode.

8. The system according to claim 1 wherein the source of breathing gas is provided in a deactivated state and the system is configured to automatically activate the source of breathing gas in case of depressurisation.

9. The system according to claim 1 wherein:

the filling threshold is a first filling threshold,

the sensor is configured to sense the filling of the reservoir at a second filling threshold lower than the first filling threshold, and

the controller is configured to resume the continuous flow when the filling sensed by the sensor is the second filling threshold.

10. The system according to claim 9 wherein the second filling threshold is at least 3% below the first filling threshold.

11. The system according to claim 1 wherein the controller is configured to adjust the flow of breathing gas at several non-null values in the continuous supply mode based on at least one first parameter.

12. The system according to claim 11 wherein the at least one first parameter is selected from the group consisting of cabin altitude, aircraft altitude, composition of exhalation gas, breathing frequency and blood oxygen saturation.

13. The system according to claim 11 wherein:

the sensor is configured to sense at least two different values of reservoir filling, and

the controller is configured to determine at least first parameter based on the values of reservoir filling sensed by the sensor.

14. The system according to claim 1 wherein the sensor is configured to send a binary signal based on the filling threshold of the reservoir.

15. The system according to claim 1 wherein the sensor is configured to sense at least two different values of reservoir filling.

16. The sensor according to claim 1 wherein the filling threshold is fullness of the reservoir.

17. The system according to claim 1 wherein the reservoir is a reservoir bag of bellows bag.

18. The system according to claim 17 wherein:

the reservoir extends between a first longitudinal end and a second longitudinal end, and

the reservoir comprises several annular pleats between the first longitudinal end and the second longitudinal end.

19. The system according to claim 18 wherein:

the reservoir is connected to the face mask through the first longitudinal end, and

the reservoir comprises a backing plate at the second longitudinal end.

20. The system according to claim 17 , wherein the sensor comprises a switch and a lanyard, and the lanyard has a first lanyard end fixed to the first longitudinal end of the reservoir and a second lanyard end connected to the second longitudinal end of the reservoir through the switch.

21. The system according to claim 1 wherein:

the reservoir comprises a flexible reservoir bag, and

the sensor comprises a strain gauge fixed on the reservoir.

22. The system according to claim 1 wherein:

the face mask comprises an inlet valve between the reservoir and a breathing cavity of the face mask, the inlet valve is a check valve.

23. The system according to claim 1 wherein:

the face mask comprises an inlet valve between the reservoir and a breathing cavity of the face mask, the inlet valve is a check valve,

the inlet valve is configured to progressively move from a closed position to an open position during the filling of the reservoir, and the inlet valve stays closed between the closed position and an intermediate position, and

the sensor is configured to detect the intermediate position.

24. The system according to claim 1 wherein:

the system comprises a RFID module connected to the sensor,

the RFID module is configured to power and read the sensor, and

the RFID module is configured to communicate with the controller.

25. The system according to claim 1 wherein the system comprises:

wherein the face mask is part of a plurality of face masks,

wherein the reservoir is part of a plurality of reservoirs, each reservoir of the plurality of reservoirs being associated with each face mask of the plurality of face masks,

wherein the sensor is part of a plurality of sensors, each sensor of the plurality of sensors being associated with each reservoir of the plurality of reservoirs and configured to sense the filling threshold in the respective reservoir, and

the controller is configured to control the continuous flow of breathing gas from the source to each reservoir of the plurality of reservoirs and to interrupt the continuous flow of breathing gas to the respective reservoir whose associated sensor senses the filling threshold in the respective reservoir.

26. A method for delivering breathing gas to passengers on-board an aircraft, comprising:

providing the system of claim 1 ,

supplying the reservoir associated with the face mask with the continuous flow of breathing gas,

sensing filling of the reservoir via the sensor,

interrupting the continuous flow of breathing gas when the filling threshold is reached.

27. The method according to claim 26 wherein the filling threshold is a first filling threshold and the method comprises:

resuming the continuous flow when the reservoir filling decreases to a second filling threshold.

28. The method according to claim 27 wherein the second filling threshold is at least 3% below the first filling threshold.

29. The method according to claim 26 wherein the filling threshold is fullness of the reservoir.

30. The method according to claim 26 comprising:

adjusting the flow of breathing gas at several non-null values in the continuous supply mode based on at least one parameter selected from the group consisting of cabin altitude, aircraft altitude, composition of exhalation gas, breathing frequency and blood oxygen saturation.

31. The method according to claim 30 wherein the continuous supply mode is a first continuous supply mode and the at least one parameter is at least one first parameter, and the method comprises:

adjusting the flow of breathing gas at a first flow in the first continuous supply mode, and

adjusting the flow of breathing gas at a second flow in a second continuous supply mode, the second flow being higher or equal to the first flow.

32. The method according to claim 31 comprising:

switching between the first continuous supply mode and the second continuous supply mode based on a second parameter.

33. The method according to claim 32 , wherein the second parameter includes presence of toxic gas in ambient gas.

34. The method according to claim 30 wherein the continuous supply mode is a first continuous supply mode and the at least one parameter is at least one first parameter, and the method comprises:

adjusting the flow of breathing gas between a low flow and a high flow in the first continuous supply mode, and

setting the flow of breathing gas at a predetermined flow in a second continuous supply mode, the predetermined flow being higher or equal to the high flow.

35. The method according to claim 26 comprising:

not supplying the reservoir with breathing gas until ambient air pressure is lower than a depressurisation threshold, and

automatically supplying the reservoir with a continuous flow of breathing gas when ambient air pressure is lower than the depressurisation threshold.