EP1391222B1 - Device for supplying breathing gas - Google Patents

Description

The present invention relates to individual devices for supplying breathing gas.

More particularly, the invention relates to an individual device for supplying respiratory gas comprising a respiratory mask for supplying a subject with respiratory gas, in particular during a flight at high altitude, this mask including itself an oronasal face cover suitable for covering the mouth and the nose of the subject, providing substantially sealing the junction with the face of the subject, the face cover being connected to an oxygen flow regulator, supplying the face cover with respiratory gas from a oxygen distributor.

In what follows, the term "oxygen" will be used to designate either pure oxygen from a storage tank, or air with a high oxygen content.

The invention finds a particularly important, although not exclusive, application in the protection of pilots of civil aircraft capable of flying at high altitudes. International regulations require that at least one of the pilots permanently wear a breathing gas supply device above flight level 410. The permanent wearing of an oronasal mask applied against the face by the harness of maintenance is embarrassing and can become painful.

Document EP-A-0691871 describes an example of such a device used in particular by the crew of transport aircraft.

Another similar device is described in WO-A-01/68187

• 1) la protection contre l'hypoxie en cas de décompression accidentelle à une altitude élevée de la cabine de l'avion ;
• 2) la protection en vol contre une ambiance toxique en cas de feu ou de fumées; et
• 3) la protection spécifique contre le risque d'hypoxie suraiguë due au caractère rapide d'une décompression accidentelle survenant à une altitude de vol supérieure à 10 668 mètres (35 000 pieds).

This type of device must provide three functions:

• 1) protection against hypoxia in the event of accidental decompression at a high altitude of the cabin of the aircraft;
• 2) protection in flight against a toxic atmosphere in case of fire or smoke; and
• (3) specific protection against the risk of acute hypoxia due to the rapidity of accidental decompression occurring at a flight altitude exceeding 10,668 meters (35,000 feet).

For the first two functions, the individual device for supplying respiratory gas must allow the inhalation of pure oxygen (or an equivalent gas) or an oxygen-enriched mixture. These first two functions are protective functions that correspond to a vital emergency and both require a high degree of reliability in the quality of the gas delivered to the subject. As a result the respirator must be tight.

For the third function, the individual device for supplying respiratory gas must make it possible to deliver to the pilot a preventive overoxygenation under normal flight conditions, in order to avoid loss of consciousness a few seconds after the decompression, even after applying a mask. breathing oxygen. This third function is a preventive function, above 10 668 meters (35 000 feet), which corresponds to normal conditions of flight and pressurization of the aircraft. It requires a permanent wearing of the mask by the flight crew. However, this is a particularly uncomfortable preventive measure for crews, especially when the breathing mask is a full-face type optical shielding mask that restricts the field of vision.

The present invention is intended to overcome this disadvantage.

As will be more fully described below, the invention aims in particular to provide the protection required for flights at high altitude by reducing the duration of the wearing of an oro-nasal mask, possibly complemented by an eye protection visor, at times when this port is made indispensable for protection against hypoxia and / or smoke.

• un respirateur facial adapté pour délivrer de l'oxygène au niveau d'au moins l'un des orifices oro-nasaux du sujet en autorisant, lors d'une inspiration de ce sujet, l'inhalation d'air ambiant, et
• des moyens de commutation de la distribution d'oxygène entre le masque respiratoire et le respirateur facial, adaptés pour couper l'alimentation en oxygène du respirateur facial et dispenser de l'oxygène au régulateur, à partir du distributeur, lorsque le sujet porte le masque respiratoire.

For this purpose, according to the invention, an individual device is provided for supplying breathing gas which, in addition to the characteristics already mentioned, is characterized by the fact that it comprises:

• a facial respirator adapted to deliver oxygen to at least one of the oro-nasal orifices of the subject by allowing, upon inspiration from this subject, the inhalation of ambient air, and
• means for switching the oxygen distribution between the respiratory mask and the facial respirator, adapted to cut the oxygen supply of the facial respirator and dispense oxygen to the regulator, from the dispenser, when the subject wears the mask respiratory.

As already indicated, the first two functions mentioned above correspond to protective functions. According to the invention, they are provided by the mask which can be cured to meet stringent criteria for protection against hypoxia, particularly in terms of sealing. This makes it uncomfortable, but these functions should only be performed in very rare emergency situations. It is accepted that the comfort of the mask is not then an essential criterion.

However, the last function is provided by the facial respirator. It can be worn in normal flight and can fulfill the third function comfortably. The third function, which corresponds to a preventive measure, does not necessarily require a great precision in the administration, the subject who carries it, of the gaseous mixture enriched with oxygen. The only constraint is that the inhaled gas mixture must contain at least a certain proportion of oxygen. The precision of the mixture, therefore the tightness of this equipment, is not critical. For this function of preventive oxygenation in the cabin, the facial respirator respects as much as possible the comfort requirement. In the event of decompression or the presence of toxic gases in the cabin, the subject carrying the facial respirator replaces this preventive equipment with a breathing mask or superimposes this mask.

• le respirateur facial comporte une canule nasale ;
• le respirateur facial comporte une coquille oro-nasale souple ;
• le masque respiratoire est adapté pour être porté lorsque le sujet porte déjà le respirateur facial ; ou, au contraire, c'est le respirateur facial qui est adapté pour être porté sous un masque respiratoire de conception classique ; par exemple, le respirateur facial comporte des branches d'alimentation suffisamment souples pour qu'elles puissent s'écraser entre le visage et le masque respiratoire, afin de conserver une bonne étanchéité de ce dernier ;
• le respirateur facial est alimenté en oxygène, à partir du distributeur d'oxygène ;
• les moyens de commutation de la distribution d'oxygène sont intercalés à la fois entre le masque respiratoire et le distributeur d'oxygène et entre le respirateur facial et le distributeur d'oxygène ;
• le respirateur facial et le distributeur d'oxygène sont adaptés pour enrichir de 40 % en oxygène, l'air inhalé par le sujet utilisant le respirateur facial ;
• le respirateur facial et le distributeur d'oxygène alimentent avec un débit continu le sujet utilisant le respirateur facial ;
• le respirateur facial et le distributeur d'oxygène alimentent le sujet utilisant le respirateur facial avec un débit pulsé uniquement pendant la phase inspiratoire du cycle respiratoire du sujet ; et
• le respirateur facial et le distributeur d'oxygène alimentent le sujet utilisant le respirateur facial avec un débit continu variant en fonction de la demande inspiratoire réelle du sujet.

In particular embodiments of the invention, one or more of the following provisions are also used:

• the facial respirator has a nasal cannula;
• the facial respirator has a soft oro-nasal shell;
• the breathing mask is adapted to be worn when the subject is already wearing the facial respirator; or, on the contrary, it is the facial respirator which is adapted to be worn under a respiratory mask of conventional design; for example, the facial respirator has supply branches sufficiently flexible so that they can crash between the face and the respiratory mask, in order to maintain a good seal of the latter;
• the facial respirator is supplied with oxygen from the oxygen dispenser;
• the switching means of the oxygen distribution are interposed both between the breathing mask and the oxygen dispenser and between the facial respirator and the oxygen dispenser;
• the facial respirator and the oxygen dispenser are adapted to enrich with 40% oxygen, the air inhaled by the subject using the facial respirator;
• the facial respirator and the oxygen dispenser supply with a continuous flow the subject using the facial respirator;
• the facial respirator and the oxygen dispenser supply the subject using the respirator facial with pulsed flow only during the inspiratory phase of the subject's breathing cycle; and
• the facial respirator and the oxygen dispenser supply the subject using the facial respirator with a continuous flow rate varying according to the actual inspiratory demand of the subject.

Other aspects, objects and advantages of the invention will appear on reading the description of some of its embodiments.

• la figure 1 représente schématiquement un exemple de dispositif individuel d'alimentation en gaz respiratoire conforme à la présente invention ;
• la figure 2 représente schématiquement en perspective un respirateur facial équipant le dispositif individuel d'alimentation représenté sur la figure 1 ;
• la figure 3 représente schématiquement en perspective un autre exemple de respirateur facial constitutif du dispositif individuel d'alimentation représenté sur la figure 1 ; et
• la figure 4 représente schématiquement en perspective un sujet portant, au-dessus du respirateur facial représenté sur la figure 2, un masque respiratoire du dispositif individuel d'alimentation en gaz respiratoire représenté sur la figure 1.

The invention will also be better understood with the aid of the drawings, in which:

• Figure 1 shows schematically an example of an individual device for supplying breathing gas according to the present invention;
• Figure 2 shows schematically in perspective a facial respirator equipping the individual feeding device shown in Figure 1;
• Figure 3 schematically shows in perspective another example of facial respirator constituting the individual feeding device shown in Figure 1; and
• FIG. 4 schematically represents in perspective a subject carrying, above the facial respirator shown in FIG. 2, a respiratory mask of the individual respiratory gas supply device represented in FIG. 1.

In the different figures, the same references designate identical or similar elements.

An embodiment of the individual device for supplying breathing gas according to the invention is presented below in detail.

According to this embodiment, shown in FIG. 1, the individual respiratory gas supply device 1 comprises a facial respirator 2, a breathing mask 3, an oxygen dispenser 4 and means for switching the oxygen distribution. 5.

The oxygen distributor 4 consists of an oxygen supply and / or an oxygen generator system, for example of the OBOGS type.

As represented in FIGS. 1 and 2, the facial respirator 2 consists, for example, of a nasal cannula 6. This cannula comprises a pair of branches 7, 8. These branches 7, 8 are adapted to be retained respectively on one ear respectively. of a subject. These branches are interconnected, firstly at a Y-junction 9 opening on a feed pipe 10 common to the two branches 7, 8, and secondly at an inhaler sleeve 11. The common supply pipe 10 is connected to the oxygen distributor 4 via the switching means of the oxygen distribution 5. The inhaler sleeve opens on two outlet ducts 12 intended to be each placed in a nostril of the subject.

When a subject carries the cannula 6, the Y junction 9 takes place behind his head, substantially between his ears, the inhaler sleeve 11 takes place under his nose and each outlet duct 12 is placed in one of his nostrils.

According to a variant, illustrated in Figure 3, the inhalation sleeve 11 is replaced by a soft oro-nasal shell 13. This oro-nasal shell 13 does not sealingly cover the mouth and the nose of the user, to allow entry for air that will be mixed with oxygen brought under this oro-nasal shell 13.

Optionally, the oro-nasal shell 13 is a cover under which is arranged a cannula similar to that described above.
This oro-nasal shell 13 may be adapted to allow correct and sufficient phonation for the effective use of a microphone such as those conventionally worn by the aircrew of the aircraft.

Many other variants of the facial respirator 2 can be envisaged. It may in particular be attached some importance to its aesthetic appearance. Indeed, there may be an interest that a pilot wearing the facial respirator 2 of the device 1 according to the invention does not appear as a patient provided with a medical device for respiratory assistance.

The cannula 6, like the oro-nasal shell 13, of the individual device 1 for supplying breathing gas according to the invention advantageously allow the subject who wears them to communicate audibly without the use of a microphone.

The cannula 6 as the oro-nasal shell 13 of the individual device 1 for supplying respiratory gas according to the invention are inexpensive and can therefore be, for hygiene reasons, disposable. In this case, the facial respirator 2 is advantageously stored in a sealed package and has a directly plug-in tip at the oxygen supply.

The breathing mask 3 is for example a so-called "full-face" mask. Such a respirator is for example described in EP-A-0691871.

As represented in FIGS. 1 and 4, this mask 3 for protecting the eyes comprises an oronasal face cover 14, a screen 15, a regulator 16 on demand and a harness 17 for rapid placement. The regulator 16 and the harness 17 are of known general constitution. The face cover 14 oro-nasal is adapted to cover the mouth and the nose of the subject who wears, providing substantially sealed the junction with the face of this subject. Preferably, it comprises a seal 18 which can be constituted by an internal fold of the edge.

The screen comprises a transparent window having an optical quality, provided with a flexible frame whose edges are trapped in a seal 19.

The breathing mask 3 is connected to the oxygen dispenser 4 via a mask box 20 and the switching means of the oxygen distribution 5.

The gasket 19 of the screen 15 and that 18 of the oro-nasal face cover 14 are of the type generally designed for the respiratory masks 3. The branches 7, 8 are sufficiently flexible to allow the effective wearing of a 3 traditional respirator, without compromising its tightness. The facial respirator is adapted so that the respirator 3 can be used without removing the facial respirator 2, while retaining substantially all the sealing properties of the respirator 3.

The switching means of the oxygen distribution 5 are installed in the mask box 20.

• une position fermée
• une première position ouverte, dans laquelle seule la canule 6 est alimentée en oxygène par le distributeur d'oxygène 4 ; et
• une deuxième position ouverte, dans laquelle seul le masque respiratoire 3 est alimenté en oxygène par le distributeur d'oxygène 4.
  Le passage de la position fermée à la première position ouverte s'effectue par une opération manuelle de l'utilisateur lorsqu'il utilise le respirateur facial 2. Selon une variante, le passage de la position fermée à la première position ouverte s'effectue automatiquement lorsque le respirateur facial 2 est extrait d'un logement de rangement ou lorsque le respirateur facial est branché.
  Dans la première position ouverte, le respirateur facial 2 est alimenté à travers un orifice calibré 22 situé en aval du robinet 21 et du distributeur d'oxygène 4. Cet orifice calibré 22, alimenté à la pression de l'oxygène détendu par un détendeur (non représenté) en aval du distributeur d'oxygène 4, garantit un débit stable quelle que soit la pression à la sortie du distributeur d'oxygène 4.
  Le passage de la position fermée, ou de la première position ouverte, à la deuxième position ouverte s'effectue automatiquement lorsque le masque respiratoire 3 est sorti de la boîte à masque 20.
  Hors conditions anormales de vol, l'alimentation préventive en oxygène du personnel navigant est assurée par la canule 6 seule. Les moyens de commutation de la distribution d'oxygène 5 sont dans une position telle que seule la canule 6 est alimentée en oxygène.
  En situation de préoxygénation en condition normale de vol, le distributeur d'oxygène 4 délivre l'oxygène
• avec un débit continu, ou
• avec un débit pulsé pendant la seule phase inspiratoire du cycle ventilatoire, ou encore
• avec un débit continu variant en fonction de la demande inspiratoire réelle.

The switching means of the oxygen distribution 5 comprise a valve 21. This valve 21 has three stable operating positions:

• a closed position
• a first open position, in which only the cannula 6 is supplied with oxygen by the oxygen distributor 4; and
• a second open position, in which only the breathing mask 3 is supplied with oxygen by the oxygen distributor 4.
  The passage from the closed position to the first open position is effected by a manual operation of the user when using the facial respirator 2. According to one variant, the transition from the closed position to the first open position is automatically carried out when the facial respirator 2 is removed from a storage slot or when the facial respirator is plugged in.
  In the first open position, the facial respirator 2 is supplied through a calibrated orifice 22 located downstream of the valve 21 and the oxygen dispenser 4. This calibrated orifice 22, supplied at the pressure of oxygen expanded by a pressure reducer (not shown) downstream of the oxygen distributor 4, guarantees a stable flow regardless of the pressure at the outlet of the oxygen distributor 4.
  The transition from the closed position, or the first open position, to the second open position is performed automatically when the breathing mask 3 is out of the mask box 20.
  Except abnormal flight conditions, the preventive oxygen supply of the aircrew is provided by the cannula 6 alone. The switching means of the oxygen distribution 5 are in a position such that only the cannula 6 is supplied with oxygen.
  In a situation of preoxygenation under normal flight conditions, the oxygen dispenser 4 delivers the oxygen
• with continuous flow, or
• with a pulsed flow rate during the only inspiratory phase of the ventilatory cycle, or
• with a continuous flow varying according to the actual inspiratory demand.

In the event of accidental depressurization, fire or the presence of toxic gases, the user seizes the breathing mask 3 located in the mask box 20. When this box 20 is opened, a signal is sent to switching means of the oxygen distribution 5. The switching means of the oxygen distribution 5 then cut off the supply of oxygen to the cannula 6 and supply oxygen directly to the respiratory mask 3.

When the user wears, in a situation of preoxygenation under normal flight conditions, the variant of the facial respirator 2 in the form of a shell 13, and when he equips himself with the breathing mask 3, over this facial respirator 2, the distribution oxygen is provided by the breathing mask 3. In this case, the means of switching of the oxygen distribution 5 trigger a regulation of the oxygen supply adapted to the situation.

For example, according to this variant of the invention, in a situation of preoxygenation, the oxygen is distributed in a simplified mode. The deployment of the breathing mask 3 corresponding to a real emergency causes the transition to a high performance oxygen regulation, conventional type. This switching can be synchronous with that of other servitudes such as the switching of a microphone.

Alternatively, the supply of the cannula 6 is cut by the switching means of the oxygen distribution 5 when the respirator 3 is in place and is operational. In this case, the control of the switching means of the oxygen distribution 5 is carried out manually by the subject himself, or automatically after a delay of a few seconds or even by a physical interaction of the facial respirator 2 with the respirator 3.

The facial respirator 2 can also be removed before the breathing mask 3 is put in place.

Claims (11)

1. An individual respiratory gas supply device comprising a respiratory mask (3) for supplying a subject with respiratory gas, especially during a high-altitude flight, the mask (3) itself comprising an oro-nasal facepiece (14) adapted for covering the mouth and nose of the subject, thereby providing a substantially leaktight junction with the face of this subject, the facepiece (14) being connected to an oxygen flow regulator (16) supplying the facepiece (14) with respiratory gas from an oxygen dispenser (4), comprising:

   - a facial respirator (2) adapted for delivering oxygen to at least one of the oro-nasal orifices of the subject without preventing inhalation of ambient air when the subject inspires, and

   - means of switching the dispensing of oxygen (5) between the respiratory mask (3) and the facial respirator (2), adapted for cutting off the oxygen supply of the facial respirator (2) and dispensing oxygen to the regulator (16) from the dispenser (14) when the subject wears the respiratory mask (3).
2. The device according to claim 1 wherein the facial respirator (2) comprises a nasal cannula (6).
3. The device according to claim 1 wherein the facial respirator (2) comprises a flexible oro-nasal shell (12).
4. The device according to any of the preceding claims wherein the respirator mask (3) is adapted to be worn when the subject is already wearing the facial respirator (2).
5. The device according to any of the preceding claims wherein the facial respirator (2) is suitable for being worn under the respiratory mask (3).
6. The device according to any of the preceding claims wherein the facial respirator (2) is supplied with oxygen from the oxygen dispenser (4).
7. The device according the claim 6 wherein the switching means for dispensing oxygen (5) are inserted both between the respiratory mask (3) and the oxygen dispenser (14) and between the facial respirator (12) and the oxygen dispenser (14).
8. The device according to any of the preceding claims wherein the facial respirator (2) and the oxygen dispenser (14) are suitable for enriching the air inhaled by the subject by 40% oxygen, using the facial respirator (2).
9. The device according to claim 8 wherein the facial respirator (2) and the oxygen dispenser (14) feed the subject using the facial respirator (2) with a continuous flow.
10. The device according to claim 8 wherein the facial respirator (2) and the oxygen dispenser (14) supply the subject using the facial respirator (2) with a continuous flow rate, pulsed only during an inspiratory phase of a respiratory cycle of the subject.
11. The device according to claim 8 wherein the facial respirator (2) and the oxygen dispenser (14) supply the subject using the facial respirator (2) with a continuous flow rate, varying according to the actual inspiratory demand of the subject.

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