PORTABLE OXYGEN SUPPLY DEVICE

Abstract

 A portable oxygen supply device is proposed, comprising an oxygen tank comprising pressurized oxygen, a supply hose couplable with the oxygen bottle and having an oxygen outlet at a distal end attachable to a nose region of a user, a pulse oximeter clampable to a body part of the user, a control valve arranged upstream of the oxygen outlet, and a control unit having a processor coupled with the pulse oximeter and the control valve, wherein the pulse oximeter is adapted for detecting an oxygen saturation of a user and providing oxygen saturation signals to the control unit, wherein the control unit is adapted to monitor a temporal progression of the oxygen saturation of the user based on the oxygen saturation signals received from the pulse oximeter, and wherein the control unit is adapted to selectively open and close the control valve based on the temporal progression of the oxygen saturation of the user to reach and maintain an increased oxygen saturation of the user.

Description

TECHNICAL FIELD

[0001] The invention relates to a portable oxygen supply device and an aircraft having at least one portable oxygen supply device.

BACKGROUND OF THE INVENTION

[0002] Cabins of commercial aircraft operating at altitudes above 3.000 m are usually pressurized. For reducing the mechanical load on the fuselage due to a pressure difference between the interior and the exterior of the cabin, the cabin pressure is usually selected to a value clearly below ambient pressure at sea level. For example, the cabin pressure may roughly be in the region of 0,74 bar, which is equivalent to the ambient pressure in an altitude of 8.000 ft (about 2.400 m), or 0,8 bar, which is equivalent to the ambient pressure in an altitude of 6.000 ft (about 1.850 m). This equivalent altitude is commonly referred to as the cabin altitude. Cockpit crew is able to use emergency oxygen with full face masks at their discretion to reduce fatigue due to the effect of cabin altitude to the human physiology, vibrations, and noise.

[0003] However, oxygen equipment usually is merely dimensioned for emergency cases and a repeated use of oxygen by the cockpit crew reduces the oxygen amount available for emergency cases. Hence, cockpit crew may avoid using their emergency equipment. In addition, full face masks are uncomfortable and disturb communication. Portable oxygen delivery systems for aviation oxygen are known, which provide an altitude and breathing rate dependent bolus of oxygen.

SUMMARY OF THE INVENTION

[0004] Besides cockpit crew, also cabin crew and passengers may have a need to selectively use oxygen for improving the well-being and decreasing symptoms of fatigue. However, in today's commercial aircraft there is no oxygen available for cabin crew or passengers for a personal use. It is thus an object of the invention to propose an apparatus for selectively delivering oxygen to cockpit or cabin crew and passengers without decreasing the amount of oxygen for emergency cases as well as without interfering with personal comfort.

[0005] This object is met by the portable oxygen supply device according to the features of claim 1. Advantageous improvements and further embodiments may be gathered from the subclaims and the following description.

[0006] A portable oxygen supply device is proposed, comprising an oxygen tank comprising pressurized oxygen, a supply hose couplable with the oxygen tank and having an oxygen outlet at a distal end attachable to a nose region of a user, a pulse oximeter clampable to a body part of the user, a control valve arranged upstream of the oxygen outlet, and a control unit having a processor coupled with the pulse oximeter and the control valve, wherein the pulse oximeter is adapted for detecting an oxygen saturation of a user and providing oxygen saturation signals to the control unit, wherein the control unit is adapted to monitor a temporal progression of the oxygen saturation of the user based on the oxygen saturation signals received from the pulse oximeter, and wherein the control unit is adapted to selectively open and close the control valve based on the temporal progression of the oxygen saturation of the user to reach and maintain an increased oxygen saturation of the user.

[0007] The oxygen tank constitutes the oxygen source and may be based on a high pressure tank, in particular a cylindrical tank. Different sizes and tank volumes allow variable supply times and may, for example, depend on a flight duration. For long-haul flights, larger oxygen tanks may be selected than for short-haul flights. To simplify handling of the oxygen tank, it may be of the same type as portable oxygen cylinders from emergency equipment. It may also be designed to be fillable at the same filling stations as portable oxygen cylinders for emergency use.

[0008] The supply hose may be made of a flexible material. It may have a cross-section that reliably allows a sufficient oxygen flow even with a slightly kinked hose. It may also be advantageous if the hose comprises a bendable stiffening element, such as a wire that allows the hose to be bent into a desired shape. This allows a customized routing to the user's nose and allows to eliminate potential interference with the user's seating or lying position or personal equipment, such as headphones or the like. The hose may be routed over the nose, forehead, and head to avoid pressure marks while sleeping sidewards.

[0009] The oxygen outlet at the distal end may be selected from different possible designs. For example, the oxygen outlet may be a nasal cannula, which is attached to or held at the nose. For holding the oxygen outlet, a clip to be clamped to the nose is conceivable. Such a clip only interferes with a single point of the face and head of the user and thus minimizes a potentially annoying contact surface with the user. Further a clip would not interfere with glasses, headsets, or other personal items. However, the oxygen outlet may also have an elastic band that is placed around the head to maintain its position. The portable oxygen device and the oxygen outlet are solely designed for breathing through the nose.

[0010] The pulse-oximeter may be based on a fractional oxygen saturation measurement technology for capturing relevant saturation values, such as of different types of hemoglobin or other substances, to allow for precise measurements. According to studies, different types of saturation values may correlate with individual factors like gender, age, BMI, and smoking status and may influence a maximum saturation level of a user. It is advantageous to clamp the pulse-oximeter to a body part, such as a finger or an ear. However, fitting to the ear is preferred, as measurements at the ear are more precise than measurements on the finger. Furthermore, clamping it to the ear provides less disturbance to the user compared to a clip at the finger or forehead. The pulse-oximeter may be coupled with the control unit through a cable or wirelessly, e.g. through a short range wireless data link.

[0011] The control valve is a controllable valve, which allows to be selectively opened or closed in order to let oxygen flow to the oxygen outlet if demanded by the control unit. The control unit is coupled to the pulse-oximeter and thus continuously receives information about the present oxygen saturation of the user's arterial blood. Hence, a temporal progression of the oxygen saturation is known and the control unit allows to reach a desired, i.e. increased oxygen saturation by controlling the control valve in order to selectively increase an oxygen supply to the user. The control valve may be provided as a separate, independent valve.

[0012] For example, the control unit may comprise a control logic that allows to provide a preferably predefined amount of oxygen into the hose for an inhalation cycle, measure the resulting oxygen saturation and determine, whether the desired increased saturation is reached. If not, a subsequent amount of oxygen will be provided for a subsequent inhalation cycle. The total mass flow of oxygen will depend on the physiological status of the user, which may include age, BMI, gender, smoker / non-smoker, and general health status. Through constantly assessing the oxygen saturation and controlling of the control valve, the control unit is capable of automatically covering these physiological status parameters to reach the increased saturation level.

[0013] Hence, the portable oxygen supply device provides a simple, efficient, lightweight, and independent solution for improving the well-being of cockpit or cabin crew or passengers on board of commercial aircraft. The cockpit crew can use the device to protect themselves from effects of altitude exposure without using the emergency oxygen system. The cabin crew can use the device to recover from work at altitude during rest in the crew rest compartment. The passengers can use the device to stay fit and awake during flight to use flight time for work or learning efficiently, or just for well-being. The device may be used upon demand, may be brought into the aircraft if desired or may be made readily available in a suitable number. The device is portable and flexibly deployable. Using the device does not reduce the amount of oxygen required for emergency use and modifications inside the aircraft cabin or in installed equipment are not necessary. It also does not affect an aircraft turnover time. It causes a different and personal volume of supplemental oxygen to reach an arterial oxygen blood saturation of close to the user's individual maximum saturation level like on ground level. Still further, aircraft operators may gain additional revenue out of selling oxygen to passengers as an anti-fatigue or wellness feature.

[0014] The control unit may comprise a control loop designed for maximizing the oxygen saturation, such that the increased oxygen saturation is a user dependent maximum oxygen saturation. The control loop may be provided in the form of an algorithm or a control logic inside the processor. It is conceivable that the control unit is adapted to control the amount of oxygen supplied to the user, such that e.g. oxygen is supplied with breathing in, if the oxygen saturation is to be increased, or not, if the oxygen saturation reaches the individual target. This means that in a series of inhalation cycles the device may deliver an amount of oxygen. The amount of oxygen may be pre-defined. At the same time, the oxygen saturation is monitored. If it turns out that the oxygen saturation does not increase anymore and remains stable, a maximum oxygen saturation can be assumed and the device may stop delivering additional amounts of oxygen. Once the monitored oxygen saturation falls under the determined maximum saturation again by a predeterminable fraction, e.g. in a range of 2% to 3%, the device may again start to deliver oxygen in a further series of inhalation cycles. If the maximum is reached the oxygen supply is stopped to avoid an excessive oxygen supply.

[0015] The device may further comprise a breathing valve upstream of the oxygen outlet adapted for maintaining a closed state unless the user breathes in and applies a negative pressure to the oxygen outlet. Thus, oxygen may only flow into the supply hose when the user breathes in. If the control unit controls the control valve to open, oxygen may not flow to the oxygen outlet if the breathing valve is closed. In an exemplary embodiment, the breathing valve and the control valve may be realized as one part, which means that the breathing valve is controllable in addition to its normal function of opening upon a negative pressure. For this, the control unit may either send a lock or an open signal to the breathing valve, wherein the open signal leads to the breathing valve to open on a negative pressure at the oxygen outlet and wherein the lock signal leads to locking the breathing valve, such that it always remains in the closed state.

[0016] It is conceivable that the control unit comprises a housing having an oxygen input and an oxygen output, wherein the control valve is arranged in fluid communication with and between the oxygen input and the oxygen output, wherein the processor is arranged on or inside the housing, and wherein a battery for powering the processor is arranged on or inside the housing. Thus, the device according to the invention may be realized by a simple and compact box, which is attachable to a replaceable oxygen tank in order to improve the well-being of the user.

[0017] At least one of the oxygen input and the oxygen output comprises or is attachable to a quick connector. Thus, the control unit and the hose are quickly and easily replaceable, e.g. for disinfection, cleaning, or maintenance, and/or can be stored separately. Oxygen tanks may be stored in a dedicated stowage unit, while supply hoses and control units may be stored in stowage compartments in direct reach of cabin crew, for example. Also, empty oxygen tanks may simple be replaced.

[0018] Dimensioning the oxygen tanks may be done according to the following. Based on the development of emergency oxygen systems for passengers, which was proven in an altitude chamber tests, an additional amount of oxygen required for maintaining an arterial blood saturation of close to 100%, is to be assumed with 8ml NTPD (Normal temperature, pressure, dry) per breath. According to SAE ARP1109 the breathing rate of an average adult in rest can be assumed with 15 breathes per minute (bpm). This would result in about 120ml/min and 7,21/h additional oxygen. For example, a standardized oxygen bottle tank having about 91 1 stored oxygen and having a size of 186 mm x 71 mm and a weight of roughly 400g would be sufficient even for long distance flights.

[0019] It is advantageous, if the control unit further comprises a display unit connected to the processor, and wherein the processor is adapted for displaying on the display unit at least one of

a) a saturation level at start of the oxygen supply device,

b) an actual saturation level,

c) a user dependent maximum saturation level,

d) a remaining amount of oxygen,

e) a remaining time of oxygen supply,

f) a charge status of an internal battery,

g) an operating status of the device.

Hence, a user may receive helpful information about the operation of the device.

[0020] Instead or additionally to a display unit, the control unit may comprise a data link device, which allows a connection to a mobile device of a user, such as a smartphone, or a personal display of an onboard entertainment system. This may allow to display even further information about the operation of the device, temporal progression of the oxygen saturation and/or oxygen supply.

[0021] The device may further comprise a pressure sensor in fluid communication with an interior space of the oxygen tank, wherein the pressure sensor is coupled with the control unit, and wherein the control unit is adapted for estimating a remaining amount of oxygen in the oxygen tank based on a measured pressure in the oxygen tank. Thus, a timely re-filling of the oxygen tank may be initiated. In case the previously mentioned display unit is used, the control unit may provide the remaining amount of oxygen on the display unit.

[0022] Still further, the control unit may be adapted for estimating a remaining time of oxygen supply based on the measured pressure in the oxygen tank or the estimated remaining amount of oxygen in the oxygen tank and an average oxygen flow. Thus, the user or maintenance personnel may be informed that a refill or a replacement of the oxygen tank should be done.

[0023] A nose clip may be arranged at the oxygen outlet, wherein the nose clip is adapted for holding the oxygen outlet at or in the nose of the user. The nose clip may be a separate part that holds the oxygen outlet. It may also conceivable that the nose clip is integrated into the supply hose. The nose clip may be designed to conform the shape of the center of the user's nose, as well as the nostrils by comprising a bendable/ deformable material, such as a wire covered by a soft and skin-friendly material. The mouth of the user remains uncovered. Thus, the user may still use headsets, which is particularly important for the cockpit crew, or other personal equipment. The user can talk and eat/drink without limitations during the use of the device.

[0024] The device may further comprise a pressure reducer removably attachable to the oxygen tank. It may be connected to the oxygen tank via a gas-tight quick connector, as well as to the control unit. The pressure reducer is designed to provide oxygen at low pressure to the control unit. The pressure reducer also ensures that the same amount of oxygen is always provided for the same valve opening time, as the pressure reducer supplies a constant upstream pressure. While the pressure inside the oxygen tank deviates at the end of the filling level of the oxygen tank can be neglected, as it is conceivable to define a residual pressure that must remain in the oxygen tank to ensure this function.

[0025] At least a section of the supply hose comprises a wire to bend the hose into a desired shape. Thus, the supply hose may easily be adapted to the individual shape of the user's head and nose. The wire may be arranged directly in the material of the supply hose or it may run inside a hollow space of the supply hose.

[0026] The oxygen outlet may comprise two branches, which are insertable into a nostril each. The branches may be connected to a junction, which connects both branches to a single hose part. It may be feasible to provide a nose clip in or near the junction.

[0027] It may be advantageous, if the two branches each comprise a wire. The branches may thus very easily be adapted to the shape of the user's nose and the user may adapt the shape of the branches to make them fit comfortably.

[0028] In light of the above description, the invention further relates to an aircraft comprising a fuselage having a pressurized cabin and at least one such oxygen supply device. The aircraft is preferably a commercial aircraft.

[0029] Still further, the invention relates to the use of an oxygen supply device according to the above description inside a pressurized aircraft cabin.

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Other characteristics, advantages and potential applications of the present invention result from the following description of the exemplary embodiments illustrated in the figures. Furthermore, identical, or similar objects are identified by the same reference symbols in the figures.

Fig. 1 shows a schematic, block-oriented view of the oxygen supply device.

Fig. 2, 3, 4, 5, 6a and 6b show different views of a user wearing the device as well as other equipment.

Fig. 7 shows an aircraft.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0031] Fig. 1 shows a portable oxygen supply device 2 comprising an oxygen tank 4 comprising pressurized oxygen, a supply hose 6 couplable with the oxygen tank 4 and having an oxygen outlet 8 at a distal end 10 attachable to a nose region of a user. The device 2 also comprises a pulse oximeter 12, which is clampable to a body part of the user. A control unit 14 comprises a housing 16, an oxygen input 18 and an oxygen output 20. Inside the control unit 14, a control valve 22 and a processor 24 are provided. The processor 24 is coupled with the control valve 22 and has a first signal link 26 to the pulse oximeter 12. A battery 28 powers the processor 24. The control valve 22 is connected to the oxygen input 18 and is exemplarily coupled with a breathing valve 30, which in turn is coupled with the oxygen output 20. The breathing valve 30 is designed to open if a negative pressure acts on the oxygen outlet 8 of the supply hose 6. Hence, if the oxygen outlet 8 is arranged in the nose region of the user and the user conducts an inhalation cycle, a negative pressure is applied to the oxygen output 20 and the breathing valve 30 opens.

[0032] The pulse oximeter 12 is adapted for detecting an oxygen saturation of a user and provides oxygen saturation signals over the first signal link 26 to the processor 24 in the control unit 14. The control unit 14, i.e. the processor 24, is able to monitor a temporal progression of the oxygen saturation of the user based on the oxygen saturation signals received from the pulse oximeter 12. The control unit 14, i.e. the processor 24, is adapted to selectively open and close the control valve 22 based on the temporal progression of the oxygen saturation of the user to reach and maintain an increased oxygen saturation. Hence, if the control valve 22 opens to release a certain amount of oxygen, this amount can be breathed in by the user through the supply hose 6. Also, an additional breathing sensor 37 may be provided, which informs the processor 24 about a user breathing in. A release of oxygen may be limited to cases where the breathing sensor 37 recognizes a user breathing in.

[0033] It is conceivable, that a connection between the control valve 22 and breathing valve 30 comprises a buffer 32, such that the control valve 22 releases the respective amount of oxygen into the buffer 32 which is then released through the breathing valve 30 in a next inhalation cycle. However, the control valve 22 and the breathing valve 30 may also be made as one part without the buffer 32. Still further, if the breathing sensor 37 is provided, the breathing valve 30 may be eliminated. Release of oxygen from the control valve 22 is only provided when the breathing sensor 37 recognizes the user breathing in and when the oxygen saturation needs to be increased.

[0034] The control unit 14 may comprise a quick connector 34, which is attachable to a pressure reducer 36, which in turn is coupled to another quick connector 34 of the oxygen tank 4. The released amount of oxygen may be predefined. The upstream pressure provided by the pressure reducer 36 may be considered constant, as long as the oxygen tank 4 comprises a minimum pressure. The opening time of the control valve 22 for releasing oxygen may also be predefined and constant.

[0035] Exemplarily, a pressure sensor 38 is provided, which is in fluid communication with the interior of the oxygen tank 4. It may comprise a second signal link 40 to the control unit 14, i.e. the processor 24. The processor 24 is thus able to monitor the pressure inside the oxygen tank for an estimation of a remaining time for oxygen supply or a remaining amount of oxygen inside the oxygen tank 4. Further, the control unit 14 is coupled with a display device 42, which may be an integral part of the control unit 14 attached to the housing 16 and/or realized through an application 44 on a mobile device 46, through which a user can gather information about the operating state of the oxygen supply device to and relevant data.

[0036] Fig. 2 shows a user 48 in a side view. Here, the supply hose 6 runs over the nose 50 and the forehead 52. The oxygen outlet 8 exemplarily comprises two branches 54 insertable into the nose 50 and exemplarily combined at a junction section 56. Inside the two branches 54 a wire 58 is integrated to provide a certain stiffness. The wire 58 may be bent to maintain a desired shape. The two branches 54 extend into the nose 50, while a nose clip 60 holds the two branches 54 on the center of the nose 50.

[0037] As shown in Fig. 3, the user 48 may easily wear glasses 62 even when the device 2 is used. Fig. 4 additionally shows the pulse oximeter 12 clamped to an ear 64 of the user. The first signal link 26 is provided in the form of a wire. Fig. 5 demonstrates the user 48 wearing the glasses 62, the pulse oximeter 12 as well as headphones 66. Fig. 6a and 6b show the user 48 in a front view with the supply hose 6 arranged on the forehead 52 (Fig. 6a) and over the shoulder (Fig. 6b).

[0038] Fig. 7 shows an aircraft 66, comprising a fuselage 68 having a pressurized cabin 70 and at least one oxygen supply device 2 according to the above.

[0039] In addition, it should be pointed out that "comprising" does not exclude other elements or steps, and "a" or "an" does not exclude a plural number. Reference characters in the claims are not to be interpreted as limitations.

REFERENCE NUMERALS

[0040] 

2

portable oxygen supply device

4

oxygen tank

6

supply hose

8

oxygen outlet

10

distal end

12

pulse oximeter

14

control unit

16

housing

18

oxygen input

20

oxygen output

22

control valve

24

processor

26

first signal link

28

battery

30

breathing valve

32

buffer

34

quick connector

36

pressure reducer

37

breathing sensor

38

pressure sensor

40

second signal link

42

display unit

44

application

46

mobile device

48

user

50

nose

52

forehead

54

branch

56

junction section

58

wire

60

nose clip

62

glasses

64

ear

66

aircraft

68

fuselage

70

cabin

Claims

1. Portable oxygen supply device (2), comprising:

- an oxygen tank (4) comprising pressurized oxygen,

- a supply hose (6) couplable with the oxygen tank (4) and having an oxygen outlet (8) at a distal end (10) attachable to a nose region of a user,

- a pulse oximeter (12) clampable to a body part of the user,

- a control valve (22) arranged upstream of the oxygen outlet (8), and

- a control unit (14) having a processor (24) coupled with the pulse oximeter (12) and the control valve (22),

wherein the pulse oximeter (12) is adapted for detecting an oxygen saturation of a user and providing oxygen saturation signals to the control unit (14),
wherein the control unit (14) is adapted to monitor a temporal progression of the oxygen saturation of the user based on the oxygen saturation signals received from the pulse oximeter (12), and
wherein the control unit (14) is adapted to selectively open and close the control valve (22) based on the temporal progression of the oxygen saturation of the user to reach and maintain an increased oxygen saturation of the user.

2. The oxygen supply device (2) of claim 1,
wherein the control unit (14) comprises a control loop designed for maximizing the oxygen saturation, such that the increased oxygen saturation is a user dependent maximum oxygen saturation.

3. The oxygen supply device (2) of claim 1 or 2,
further comprising a breathing valve (30) upstream of the oxygen outlet (8) adapted for maintaining a closed state unless the user breathes in and applies a negative pressure to the oxygen outlet (8).

4. The oxygen supply device (2) of any of the preceding claims,
wherein the control unit (14) comprises a housing (16) having an oxygen input (18) and an oxygen output (20),
wherein the control valve (22) is arranged in fluid communication with and between the oxygen input (18) and the oxygen output (20),
wherein the processor (24) is arranged on or inside the housing (16), and wherein a battery (28) for powering the processor (24) is arranged on or inside the housing (16).

5. The oxygen supply device (2) of claim 4,
wherein at least one of the oxygen input (18) and the oxygen output (20) comprises or is attachable to a quick connector (34).

6. The oxygen supply device (2) of any of the preceding claims,
wherein the control unit (14) further comprises a display unit (42) connected to the processor (24), and
wherein the processor (24) is adapted for displaying on the display unit (42) at least one of

h) a saturation level at start of the oxygen supply device (2),

i) an actual saturation level,

j) a user dependent maximum saturation level,

k) a remaining amount of oxygen, and

1) a remaining time of oxygen supply.

7. The oxygen supply device (2) of any of the preceding claims,
further comprising a pressure sensor (38) in fluid communication with an interior space of the oxygen tank (4),
wherein the pressure sensor (38) is coupled with the control unit (14), and wherein the control unit (14) is adapted for estimating a remaining amount of oxygen in the oxygen tank (4) based on a measured pressure in the oxygen tank (4).

8. The oxygen supply device (2) of claim 7,
wherein the control unit (14) is adapted for estimating a remaining time of oxygen supply based on the measured pressure in the oxygen tank (4) or the estimated remaining amount of oxygen in the oxygen tank (4) and an average oxygen flow.

9. The oxygen supply device (2) of any of the previous claims,
wherein a nose clip is arranged at the oxygen outlet (8),
wherein the nose clip is adapted for holding the oxygen outlet (8) at or in the nose of the user.

10. The oxygen supply device (2) of any of the previous claims,
further comprising a pressure reducer removably attachable to the oxygen tank (4).

11. The oxygen supply device (2) of any of the previous claims,
wherein at least a section of the supply hose (6) comprises a wire (58) to bend the hose (6) into a desired shape.

12. The oxygen supply device (2) of any of the previous claims,
wherein the oxygen outlet (8) comprises two branches (54), which are insertable into a nostril each.

13. The oxygen supply device (2) of claims 11 and 12,
wherein the two branches (54) each comprise a wire (58).

14. Aircraft, comprising a fuselage having a pressurized cabin and at least one oxygen supply device (2) according to any of the preceding claims.

15. Use of an oxygen supply device (2) according to any of the claims 1 to 13 inside a pressurized aircraft cabin.

Drawing