A system for the delivery of supplemental oxygen

Abstract

A system 10 for delivery of supplemental oxygen supplies pressurised oxygen via a restrictor 28 and reservoir 30 to a demand valve 20 fitted to a mask 12 that is worn by a user. The mask 12 also inclu

Claims

1. An oxygen delivery system (10, 70, 150) including: a mask that is configured to seal around a user’s mouth and nose, the mask including a demand valve (20) and an air intake valve (16, 74);A reservoir (30); andA restrictor (28, 156); whereinThe restrictor (28, 156) is located upstream of the reservoir in a supply line (22, 76, 152) that provides fluid communication between the demand valve (20) and an end that is connectable to a source of pressurised oxygen.

2. An oxygen delivery system (10, 70, 150) in accordance with claim 1 wherein the demand valve (20) is a negative pressure direct acting demand valve.

3. An oxygen delivery system (10, 70, 150) in accordance with claim 2 wherein the demand valve (20) is a tilt valve.

4. An oxygen delivery system (10, 70, 150) in accordance with any one of claims 1 to 3 wherein the air intake valve (16) is configured to open when the reservoir 30 is almost depleted.

5. An oxygen delivery system (10, 150) in accordance with any preceding claim wherein the air intake valve (16) and demand valve (20) are configured such that the air intake valve (16) requires more suction to generate flow.

6. An oxygen delivery system (70, 150) in accordance with any one of claims 1 to 4 wherein the air intake valve (74) includes a pilotingchamber (86) that is in fluid communication with the reservoir (30), the air intake valve (74) being opened and closed in accordance with a pressure in a piloting chamber (86).

7. An oxygen delivery system (70, 150) in accordance with claim 6 wherein the air intake valve (74) is configured such that it is closed in response to a high reservoir pressure and open in response to a low reservoir pressure.

8. An oxygen delivery system (70, 150) in accordance with claim 7 wherein the air intake valve (74) includes a biasing means (90) that applies an opening biasing force that is countered by pressure in the piloting chamber (86).

9. An oxygen delivery system (70, 150) in accordance with any one of claims 6 to 8 wherein the system includes a delay feature (78, 88, 92A, 92B) that is arranged to delay at least one of the opening and closing response of the air intake valve (74) to changing reservoir pressure.

10. An oxygen delivery system in accordance with claim 9 wherein the delay feature includes a delay mechanism (78) that is arranged to delay communication of a rising reservoir pressure and / or of a falling reservoir pressure to the piloting chamber (86).

11. An oxygen delivery system (70, 150) in accordance with claim 9 or 10 wherein the delay feature includes a frictional force that is generated by opening and closing the air intake valve (74).

12. An oxygen delivery system (70, 150) in accordance with any one of claims 9 to 11 wherein the delay feature includes a pair of magnets (92A, 92B) respectively secured to a moveable piston (80) and to a fixed wall of the valve (74) and configured such that a magnetic forcebetween the pair of magnets (92A, 92B) must be overcome either to close or to open the valve (74).

13. An oxygen delivery system (70, 150) in accordance with claim 10 wherein the delay mechanism (78) includes first (108) and second (112) channels arranged in parallel, the first channel (108) permitting flow in a direction that communicates rising reservoir pressure to the piloting chamber (86) and the second channel (112) permitting flow in a direction out of the piloting chamber (86) and wherein the first channel (108) includes one of: a sprung non-return valve (110), a non-sprung non-return valve, a restrictor and a valve that opens and closes in response to a specific gauge pressure; and wherein the second channel (112) includes one of: a sprung non-return valve, a non-sprung nonreturn valve (114), and a valve that opens and closes in response to a specific gauge pressure.

14. An oxygen delivery system (70, 150) in accordance with any one of claims 9 to 13 wherein the delay feature (78, 88, 92A, 92B), restrictor (156) and reservoir (30) are adaptable to supply pressure such that reservoir pressure falls to a value that causes the piloted air intake valve (74) to open during a user’s inhalation cycle and such that reservoir pressure rises to a value that causes the piloted air intake valve (74) to close during exhalation by a user.

15. An oxygen delivery system in accordance with any one of claims 6 to 14 wherein the air intake valve (16) and demand valve (20) are configured such that the air intake valve (16) requires less suction to generate flow.

16. An oxygen delivery system (10, 70, 150) in accordance with any preceding claim wherein the reservoir (30, 30A) includes a volume within a hose connecting components of the oxygen delivery system.

17. An oxygen delivery system (10, 70, 150) in accordance with any preceding claim wherein the reservoir (30, 30B) includes a chamber that is in fluid communication with the supply line.

18. An oxygen delivery system (10, 70, 150) in accordance with any one of claims 1 to 17 wherein the restrictor (28, 156) is a variable restriction, with one or more selectable values.

19. An oxygen delivery system (10, 70, 150) in accordance with claim 18 wherein one of the selectable values is close to zero restriction such that permitted flow in the delivery system exceeds an anticipated maximum flow that is demanded by a user.

20. An oxygen delivery system (10, 70, 150) in accordance with claim 18 or 19 wherein the variable restriction includes a needle valve.

21. An oxygen delivery system (10, 70, 150) in accordance with claim 18 or 19 wherein the variable restriction is a rotatable arrangement of different restrictors, each with a respective restriction size.

22. An oxygen delivery system (150) in accordance with any one of claims 1 to 19 wherein the restrictor (156) is located in a first feed channel 154A that is arranged in parallel with a second feed channel (154B), and the system additionally includes an output selection piston (158) that is switchable between a first position in which gas flowing therein is directed to the first feed channel (154A) and a second position in which gas flowing therein is directed to the second feed channel (154B).

23. An oxygen delivery system (150) in accordance with claim 22 wherein when the output selection piston (158) is in its second position, gas is directed to the second feed channel (154B) in addition to the first feed channel (154A).

24. An oxygen delivery system (150) in accordance with claim 22 or 23 that also includes a switching mechanism responsive to atmospheric pressure, wherein if atmospheric pressure is below a threshold level then the output selection piston (158) is in its second position and if the atmospheric pressure is above a threshold level then the output selection piston (158) is in its first position.

25. An oxygen delivery system (150) in accordance with claim 24 wherein the output selection piston (158) includes:a piston (186) with narrowed portion (192) that is moveable within a bore (188) that is lined with at least three discrete sealing means (190);a link passage (170) that opens into the bore (188) between a second and third sealing means;a first feed channel (154A) that includes the restrictor (156) opens into the bore (188) between the second and final sealing means; a second feed channel (154B) opens into the bore (188) between the first and second sealing means;biasing means (194) arranged to urge the piston (186) to a first configuration anda control chamber (200) adjacent the piston (186) and in fluid communication via a bleed restrictor (204) with a gas source, in which a build up of gas pressure within the chamber (200) serves to urge the piston (186) to a second configuration.

26. An oxygen delivery system (150) in accordance with claim 25 wherein: the first configuration of the piston (186) is one in which the narrowed portion (192) is aligned beyond the second sealing means with the link passage in fluid communication with the first feed channel (154A) and such that fluid flow from the link passage into the second feed channel (154B) is blocked; andthe second configuration of the piston (186) is one in which in which the narrowed portion (192) is aligned with the second sealing means, thereby allowing fluid flow from the link passage into the second feed channel (154B); andthe switching mechanism includes a pressure responsive element (208) and a switching valve (206) whereby the switching valve (206) may be either open or closed in response to a state of the pressure responsive element (208) such that when the switching valve (206) is in its low-pressure configuration, fluid flow is directed into the control chamber (200).

27. An oxygen delivery system (150) in accordance with claim 26 wherein the pressure responsive element (208) is an aneroid.

28. An oxygen delivery system (150) in accordance with any preceding claim wherein the system includes an input selection piston (160) that is switchable between a first configuration in which a first input line (162A) is placed in fluid communication with the supply line (152, 170) and a second configuration in which a second input line (162B) is placed in fluid communication with the supply line (152, 170) and wherein the first input line (162A) is connectable to a cylinder (24) fitted with a pressure regulator (26) and the second input line (162B) is connectable to a secondary oxygen source (164).

29. An oxygen delivery system (150) in accordance with claim 28 wherein the input selection piston (160) includes:a piston (172) with narrowed portion (178) that is moveable within a bore (174) that is lined with three discrete sealing means (176b);a link passage (170) that opens into the bore (174) between the second and third sealing means;an input cylinder port (180) that opens into the bore (174) between the first and second sealing means;biasing means (182) arranged to urge the piston (172) to a configuration in which the narrowed portion (178) is aligned with the second sealing means, thereby allowing fluid flow from the input cylinder port (180) to the link passage (170); and whereinon connection of a connector (184) to a supply port (186), pressure arising from fluid flowing into the input selection piston (160) from the supply port (186) urges the piston (172) towards a configuration in which an end of the piston (172) no longer contacts the third sealing means, thereby allowing fluid flow from the supply port (186) to the link passage (170).

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