WO2002016010A1

WO2002016010A1 - System and method for controlling an atmosphere

Info

Publication number: WO2002016010A1
Application number: PCT/GB2001/003829
Authority: WO
Inventors: Angela Lebaigue; Dennis Lebaigue
Original assignee: Edge4 Ltd
Priority date: 2000-08-23
Filing date: 2001-08-23
Publication date: 2002-02-28
Also published as: GB0020809D0; AU2001284177A1

Abstract

Provided is a system for controlling an atmosphere in a substantially enclosed space, which system comprises: (a) a gas separator comprising a hollow-fibre membrane for separating air into a nitrogen-rich fraction and an oxygen rich fraction; and (b) a substantially closed space communicating with the gas separator, which enclosed space is sufficiently large to accommodate a subject when sleeping, resting or exercising; wherein the system is capable of maintaining both a hypoxic atmosphere and a hyperoxic atmosphere in the closed space by introducing the nitrogen-rich and/or the oxygen-rich fraction into the closed space.

Description

SYSTEM AND METHOD FOR CONTROLLING AN ATMOSPHERE

The present invention relates to a method for regulating the atmosphere in a substantially closed space. The closed space may be large or small, such as a sports facility, office block, hotel room, sleeping room, animal shelter or the like. In particular, the present invention relates to controlling the partial oxygen pressure in an atmosphere.

It has been known for some time that varying the level of oxygen in an atmosphere can have many different benefits for those breathing that atmosphere. Reduced oxygen (hypoxic) levels are beneficial for acclimatising to high altitudes and have been used for training athletes and climbers. Increased oxygen (hyperoxic) levels have been used in therapy to, amongst other things, increase the speed of healing by increasing oxygen levels in tissue.

In more detail, previous methods of hypoxic training have been based on creating an oxygen-depleted environment that simulates differing altitudes of mountain air. This activates the immune system and protective forces of the organism, and is used for medical, health and fitness purposes. Hypoxic training has been employed as a drug-free alternative for the treatment and prevention of _ cardiopulmonary, gastrointestinal, gynaecological, skin and ocular diseases, as well as various types of allergy, neurological disturbances, and other diseases. Hypoxic training has also been used successfully for increasing strength, endurance, vitality and resistance to disease of healthy people and especially athletes.

Previous methods of generating a hyperoxic environment have often utilised hyperbaric chambers. However, these chambers are costly, and have very limited flexibility in how they may be used. Thus, they are generally only usable for lying and/or sleeping. Other methods have employed bottled gases forming a "pre-made" atmosphere having the desired percentage of oxygen (see US 5,860,857). There are a number of disadvantages . with these types of method. In particular they are very costly, since they require nitrogen and oxygen to be fully isolated, before recombining them at the desired percentage. Moreover, these methods also require continual replacement of bottled supplies, and are subject to problems of safety arising from the need to carefully control gas mixing (too much or too little oxygen can clearly be fatal). In addition, mixing gases requires a large quantity of bottled gas over any significant period of time, which limits the portability of any apparatus making use of this system. US 5,860,857 discloses a method and apparatus of this type for controlling the atmosphere of a closed space. The method involves introducing nitrogen or a mixture of nitrogen and oxygen into the space, which mixture is pre-blended, preferably from liquid nitrogen and liquid oxygen. Hypoxic or hyperoxic conditions may be employed.

Various methods have been devised to improve upon this approach. US 5,799,652 discloses a hypoxic room system and equipment for hypoxic training and therapy. The method for controlling the atmosphere in this system involves a membrane air-separation or molecular sieve air-separation device for producing nitrogen-rich air. Nitrogen-rich air is fed into the room of the system to create and maintain the hypoxic atmosphere. US 6,009,870 discloses an apparatus for producing a gas mixture for hypoxic training. The apparatus comprises a gas separation unit communicating with a patient mask. The mask is fixed to the face of a patient to deliver a hypoxic breathing mixture during training. The apparatus uses hollow fibres of poly-4-methylpentene-l.

The above systems and methods are associated with a number of disadvantages. The method of US 5,860,857 is costly, non-portable and may be unsafe without careful and time-consuming monitoring of gas mixing. The method of US 5,799,652 is non-portable, and inflexible since it does not allow for producing hyperoxic conditions. The apparatus of US 6,009,870 is mounted on a wheeled trolley and is linked to the subject via a conduit and a mask. The apparatus is bulky, heavy and does not allow the subject freedom of movement for proper exercise.

An objective of the present invention is to solve the problems associated with the above prior art. A further aim of the present invention is to provide a system that is able to provide both a hypoxic and a hyperoxic environment, whilst being efficient, cheap, safe and portable. It is also an aim of the present invention to provide an exercise or therapy environment that is comfortable and stimulating, encouraging exercising either for sporting or for health purposes.

Accordingly, the present invention provides a system for controlling an atmosphere in a substantially enclosed space, which system comprises:

(a) a gas separator comprising a hollow-fibre membrane for separating air into a nitrogen-rich fraction and an oxygen rich fraction; and

(b) a substantially closed space communicating with the gas separator, which enclosed space is capable of accommodating a subject whilst sleeping, resting or exercising; wherein the system is capable of maintaining both a hypoxic atmosphere and a hyperoxic atmosphere in the closed space by introducing the nitrogen-rich and/or the oxygen-rich fraction into the closed space.

The present invention further provides a portable system for controlling an atmosphere, which portable system comprises:

(a) a gas separator comprising a hollow fibre membrane for separating air into a nitrogen-rich fraction and an oxygen rich fraction; and

(b) a mask communicating with the gas separator, for delivering the controlled atmosphere to a subject for breathing; wherein the system is capable of delivering both a hypoxic atmosphere and a hyperoxic atmosphere to the subject by introducing the nitrogen-rich and or the oxygen-rich fraction into the mask, and wherein the system is capable of being carried by the subject whilst sleeping, resting or exercising.

The present invention allows for the provision of both hypoxic and hyperoxic conditions using the same equipment. Thus, in the systems of the present invention, both the nitrogen-rich outlet from the gas separator and the oxygen-rich outlet from the gas separator should be configured to communicate with the closed space or with the mask. This communication need not necessarily allow gases to pass freely into the closed space or mask, since under hypoxic conditions for example, oxygen-rich gas will not usually be required. Rather, the system has the ability to feed either nitrogen-rich gas or oxygen-rich gas (or a combination of both) into the closed space or mask as desired. Nitrogen-rich and/or oxygen-rich gas may be selected by, for example, including a controllable valve in the nitrogen-rich feed and a further controllable valve in the oxygen-rich feed, which valves can be independently opened or closed to select the desired gas mix to be fed to the closed space or the mask.

The use of hollow-fibre membranes is especially advantageous, since these membranes are highly efficient and allow for rapid separation of air into nitrogen-rich and oxygen-rich fractions. This allows the present system to provide both hypoxic and hyperoxic environments whilst being cheap and easy to operate. Large volumes of atmosphere, such- as an entire training room may be controlled using relatively light and small equipment. Moreover, using hollow-fibre membrane technology allows a very light system to be built that is still capable of delivering sufficient atmosphere to an exercising individual, making the present system portable in some embodiments. Thus, the system can be adapted to smaller closed spaces, such as a portable face mask which may be used in the open air, as well as indoors.

The present invention may be employed to simulate any mountain altitude, i.e. to the height of (and if desired higher than) any mountain in the world, to allow for preparation for ascending such peaks. The present system is also capable of simulating athletic altitude- training camps and alpine spas and therapy resorts. The present invention also finds utility in hypoxic and hyperoxic therapy, such as intermittent hypoxic and hyperoxic therapy. In hyperoxic therapy, the system can increase the amount of oxygen available to an organism. This allows for increasing the saturation of oxygen in the blood plasma and tissue fluids. This helps increase circulation, promoting capillary growth and renewing healthy tissue function. The organism can thus heal more quickly (the resultant increased oxygen carrying capacity allows more oxygen to be available to capillaries and cellular tissue allowing for improved repair processes and rehabilitation) or operate/work more efficiently. As mentioned above, the present system is able to provide both hypoxic and hyperoxic atmospheres using the same device. Preferably the system comprises an oxygen level selector for varying the oxygen level in the enclosed space. This selector may simply select hypoxic or hyperoxic conditions, or preferably may select the specific oxygen level in the enclosed space. A preferable type of oxygen level selector is one employing remotely controllable valves in the nitrogen-rich and oxygen-rich feeds, as already discussed above.

The present invention will now be described in more detail.

The subject referred to in the present invention is generally a human or an animal. Thus the present invention may be used in the care of animals as well as humans, such as in an animal home or shelter, or in a vetenary procedure carried out on household pets.

The closed space used in the present system is not especially limited, provided that it is capable of accommodating the subject. The closed space need not be completely closed to the outside, but rather should be sufficiently closed to enable the atmosphere within the closed space to be controlled reliably. Thus the closed space is a substantially closed space. The closed space may be any type of closed space, including a box, a cubicle, a chamber, a room, or a hall. Preferably the closed space has a volume of 150 m.3 or less, more preferably a volume of from 0.1-30 τrβ. In a preferred embodiment, the closed space comprises a large space, such as a room for sleeping, resting or exercising, e.g. a gym. However, the invention also extends to enclosed spaces small enough to accommodate a small animal, such as a household pet (e.g. a mouse, cat or dog), and also intermediately sized closed spaces large enough to accommodate a single person in a sitting or lying position for resting or sleeping.

The level of oxygen in the controlled atmosphere formed using the present system is not especially limited, and depends on the purpose of the controlled atmosphere. Generally, the present system is capable of maintaining an atmosphere having an oxygen content in the range 5-40 vol.%, preferably 10-40 vol.%. More preferably, the system is capable of maintaining an oxygen content in the range 13-30 vol.%. Preferred oxygen levels maintained using the present invention can be summarized thus:

Low-oxygen levels: (from 5 to 13 vol.%, preferably from 7 to 13 vol.%) - for acclimatisation to extreme elevations (e.g. for mountaineers); for intermittent exposure for athletic conditioning; and for controlled medical exposure for illness and ailment.

Reduced-oxygen levels: (from 13 to less than 21 vol.%) - for athletic conditioning; and mild acclimatisation for sports.

Reduced and enhanced oxygen levels, preferably in combination - (from 13 to 40 vol.%, preferably from 13 to 30 vol.%) - rejuvenation and vitality; sporting rehabilitation and recovery; athletic conditioning; and medical improvement.

Enhanced oxygen levels (from more than 21 to 40 vol.%); sports rehabilitation and recovery; and medical therapy.

As mentioned above, hollow fibre membranes are employed in the present invention in gas separators. Hollow-fibre membranes that can be used in the present invention include an NX 1 600, an ML3, an NG3, an M Oxy and an ML Oxy (all from Aquilo Gas Separation BN).

The volume of nitrogen-rich and/or oxygen-rich gas delivered by the system is not especially limited, and depends on the number of subjects within the atmosphere, and the breathing requirements of the subjects (the larger the subject and the more the subject exercises, the larger the quantity of gas required for breathing). Generally, the gas separator is capable of delivering from 1-50001/min of nitrogen-rich or oxygen rich gas.

The number and type of hollow-fibre membrane units employed in the gas separator of the present system depends on the volume of air required by the subject. Clearly, the larger the closed space, the more subjects, and the greater the exercise undertaken by the subjects, the greater will be the volume of air required and the more (or larger) the membrane units required. In some embodiments there may be a plurality of gas separators, where a large number of membrane units is required.

Some specific examples of systems using particular membrane units are outlined below, although these are exemplary systems only.

- Portable system for passive use (e.g. sitting /lying)

1 NX 1-600 membrane (Aquilo Gas Separation BN) + optional appropriate compressor and associated devices to ensure quality and control (e.g. climate control/oxygen level monitor)

- Single sleeping room

1 NX 1-600 (Aquilo Gas Separation BN) + extras as above if desired

- Multiple sleeping dormitory/animal shelter

1 ΝG 3, and 1 M-oxy (Aquilo Gas Separation BN) + extras as above if desired

- Standard training-style chamber

1 x ML2 and 1 x ML-oxy & M-oxy (Aquilo Gas Separation BN) + extras as above if desired

- Large training gym e.g. up to 150 m.3

1 x ML3 & ML2 and 7x ML-oxy (Aquilo Gas Separation BN) + extras as above if desired

Systems may be designed as required by evaluating the respiratory response of the individuals in the environment and ensuring an appropriate flow rate is supplied. This allows for total control of the atmosphere by regulating the flow of gas into the closed space, depending on the requirements determined. The capacity of the membranes employed may be used in each case to calculate a solution to any volume and specification of air. Combinations of the various membranes and other elements, e.g. a compressor may then be constructed to provide the appropriate air feed.

In the following is provided an example of membranes usable over a range of air requirements:

10 1/min l NXl-600

100 1/min 1 x NG3 + 1 x M-oxy

250 1/min 1 x ML2 + 1 x M-oxy + 1 x ML-oxy

10001/min 1 x ML3 + 1 x ML2 + 7 x ML-oxy

The system of the present invention may comprise further components for optimising performance. Thus, in a preferred embodiment the system further comprises a compressor for compressing gas prior to introducing the gas into the gas separator. The system may also further comprise a filter for filtering gas prior to introducing the gas into the gas separator. As mentioned above, the system may in addition comprise a control system for controlling the oxygen level of the atmosphere. Preferably, the oxygen level of the atmosphere may be controlled from within the closed space for ease of use by the subject. In some embodiments, the system further comprises a climate controller, which is preferably capable of controlling the humidity of the atmosphere delivered to the subject.

The present invention further provides a method for regulating the atmosphere in a substantially enclosed space, which method employs a system as defined above. Further provided by the present invention is a method for supplying a controlled hypoxic or hyperoxic atmosphere to a subject, which method comprises delivering the controlled atmosphere to the subject for breathing via a system as defined above. Still further provided by the present invention is a method for acclimatising a subject to high altitude, which method comprises delivering a controlled hypoxic atmosphere to the subject according to a method as defined above. Preferably this latter method is a method for training mountaineers or athletes.

Claims

CLAIMS:

1. A system for controlling an atmosphere in a substantially enclosed space, which system comprises:

2. A system according to claim 1, wherein the closed space has a volume of 150 vc? or less.

3. A system according to claim 2, wherein the closed space has a volume of from 0.1-30 m³.

4. A system according to any preceding claim, wherein the closed space comprises a room for sleeping, resting or exercising.

5. A portable system for controlling an atmosphere, which portable system comprises:

(b) a mask communicating with the gas separator, for delivering the controlled atmosphere to a subject for breathing; wherein the system is capable of delivering both a hypoxic atmosphere and a hyperoxic atmosphere to the subject by introducing the nitrogen-rich and/or the oxygen-rich fraction into the mask, and wherein the system is capable of being carried by the subject whilst sleeping, resting or exercising.

6. A system according to any preceding claim, wherein the subject is a human or an animal.

7. A system according to any preceding claim, which system is capable of maintaining an atmosphere having an oxygen content in the range 10-40 vol.%.

8. A system according to claim 7, which system is capable of maintaining an atmosphere having an oxygen content in the range 13-30 vol.%.

9. A system according to any preceding claim, wherein the gas separator is capable of delivering from 1-5000 1/min of nitrogen-rich and/or oxygen rich gas.

10. A system according to any preceding claim, which further comprises a compressor for compressing gas prior to introducing the gas into the gas separator.

11. A system according to any preceding claim which further comprises a filter for filtering gas prior to introducing the gas into the gas separator.

12. A system according to any preceding claim, which further comprises a control system for controlling the oxygen level of the atmosphere.

13. A system according to claim 12, wherein the oxygen level of the atmosphere may be controlled from within the closed space

14. A system according to any preceding claim, which further comprises a climate controller.

15. A system according to claim 14, wherein the climate controller is capable of controlling the humidity of the atmosphere delivered to the subject.

16. A system according to any preceding claim, which further comprises a means for introducing an aromatherapy agent into the closed space.

17. A method for supplying a controlled hypoxic or hyperoxic atmosphere to a subject, which method comprises delivering the controlled atmosphere to the subject for breathing via a system as defined in any preceding claim.

18. A method for acclimatising a subject to high altitude, which method comprises delivering a controlled hypoxic atmosphere to the subject according to a method as defined in claim 17.

19. A method according to claim 18, for training mountaineers or athletes.