WO2007058574A1

WO2007058574A1 - Inhalation mask with evacuation system

Info

Publication number: WO2007058574A1
Application number: PCT/SE2006/001153
Authority: WO
Inventors: Jonas Jacobsson
Original assignee: Aga Ab
Priority date: 2005-10-13
Filing date: 2006-10-12
Publication date: 2007-05-24
Also published as: SE0502243L; SE528604C2

Abstract

An inhalation mask (1) for administering gas and any pharmaceutical preparation entrained by the gas, to a user, comprising a cup-shaped inner mask part (3) with an edge (4) adapted, in a first use position, to abut against the user's (2) face. The inner mask part (3) is connected by connecting means (5, 6, 7) to a gas inlet (8) and a gas exhaust means (9), adapted to exhaust the exhaled gas, and the mask (1) further comprises an outer mask part (11) which surrounds the inner mask part (3) and substantially extends from the edge (4) away from the user's (2) face and defines a gap (12) between itself and the inner mask part (3). The outer mask part (11) is connected to the gas exhaust means (9) for optionally generating a negative pressure in the gap (12) for exhausting an exhalation gas, and the mask (1) is characterised in that it further comprises a carrier device (13) adapted to be arranged on the user (2) and carry the mask (1) to enable a second use position in which the user's face (2) is substantially released from the inner mask part (3).

Description

EVACUATION SYSTEM

Field of the Invention

The present invention relates to the field of inhalation masks for administering gas and any pharmaceutical preparation entrained. Background Art

Inhalation masks of different types have been used for a long time in nursing to dose pharmaceutical preparations, from the time when anaesthetics were given by dropping ether on the inhalation mask until the current more sophisticated sorts where different gas mixtures, aerosols and pharmaceutical preparations can be entrained by the inhaled gas and reach a patient, for the desired purpose to be achieved. A problem with the previous masks was that the air inhaled by the patient was exhaled into the ambient air, which had a detrimental effect on the ambient personnel. The problem is extremely serious when, for example, a surgeon, dentist or like person is generally affected by an anaesthetic agent for example. Exposure to the frequently used anaesthetic agent nitrous oxide (laughing gas) has, for example, been found to involve an increased risk of miscarriage. Of course, this is a great concern for people who are often in contact with these gases, such as maternity staff and the like.

The problems have been studied in detail and have been found to be so serious that many users of the gas mixtures in question have contemplated stopping using the products . These obvious problems have resulted in the development of a number of different inhalation masks where the return gas (the gas which is exhaled or alternatively has not been inhaled) is taken care of. US-A-4 015 598 discloses a double-walled inhalation mask in which the return gas, which is not immediately sucked in through a duct opening but tries to escape between the user' s face and the edge of the mask, is sucked in through holes between the double walls of the mask. In use, the mask is adapted to fit tightly against the user's face.

A common feature of the inhalation masks according to prior art is that they are adapted to abut sealingly, that is as sealingly as possible, against the patient's face and that a device should take care of the exhalation gas which after all escapes under the edge of the mask. The above description of problems is particularly relevant for paramedic nursing in which emergency patients are treated in a limited space. In a project performed by the applicant, it has also been found that in this specific situation, or any situations in similar circumstances, another problem arises, that is the patient's sensation of discomfort of having an inhalation mask pressed tightly against his face. In asthmatic patients for instance, where feelings of panic make an attack worse, this is an extremely serious problem, but also for other patients, an ambulance ride may be required by a traumatic experience and a shut-in feeling may make the experienced general condition of health worse. Furthermore, during treatment in emergency situa- tions it may be necessary to be able to effectively communicate with the person who is being treated, which is made difficult if the person is provided with a tight- fitting mask. A study performed by the applicant has also demonstrated that inhaled gases, such as laughing gas, and also some pharmaceutical preparations in powder or aerosol form remain in the patient's lungs and are spread in the exhalation air for a long time after termination of the treatment, which in prior art technique corresponds to the fact that the mask has been removed from the patient's face. The study demonstrated residence times of laughing gas in the lungs amounting to several minutes. This means that during these minutes the patient exhales gas that reaches the ambient air, which is harmful to the people in this environment. Moreover it seams as if the current routines in treatment with, for example, laughing gas do not take this fact into consid- eration.

Summary of the Invention

An object of the present invention is to solve the above-mentioned and other problems. This object is achieved by an inhalation mask for administering gas and any pharmaceutical preparation entrained by the gas, to a user, comprising a cup-shaped inner mask part with an edge adapted, in a first use position, to abut against a user's face, connected by connecting means to a gas inlet and a gas exhaust means adapted to exhaust the exhaled gas, further comprising an outer mask part which surrounds the inner mask part and substantially extends from the edge away from the user' s face and defines a gap between itself and the inner mask part, the outer mask part being connected to the gas exhaust means for optionally generating a negative pressure in the gap for exhausting an exhalation gas, said mask being characterised in that it further comprises a carrier device adapted to be arranged on the user and carry the mask to enable at least a second use position in which the user's face is substantially released from the inner mask part.

The option of arranging the mask in the second use position results in advantages to the user, which eliminate some of the experienced problems with masks accord- ing to prior art technique, while at the same time the gas exhaust means and the gap make it possible to evacuate exhaled gas from the space in which the user is positioned. Furthermore the user, when feeling that a sufficient amount of the pharmaceutical preparation has been inhaled, can leave hold of the mask, in which case it falls down in the second use position, in which it continuous to collect exhaled gas and at the same time is conveniently placed in case additional treatment is necessary.

According to one embodiment, the mask further comprises a conduit for introducing pharmaceutical prepara- tions, preferably in gas, powder or aerosol form, connected to the gas inlet. This makes it possible for the user or the treating personnel to utilise the mask for other preparations than prepared gas mixtures, for instance for asthma medicine or the like. In such utili- sation, an auxiliary flow is preferably used to entrain the pharmaceutical preparation.

The inhalation mask preferably comprises a shifting means to ensure that the main extraction of exhalation gas takes place through the connecting means arranged in the inner mask part in the first use position and through the gap in the second use position. This allows the extraction to take place at a substantially constant flow rate and besides ensures that the breathing gas containing any additives is not immediately exhausted through the connecting means before it reaches the user.

According to a preferred embodiment, the shifting means comprises a demand valve of substantially known design .

A reliable way of ensuring the inventive concept is to let the mask in the second use position be pivoted away from the user's face in such a manner that it abuts against the user with its lowermost portion only. In this manner, the upper mask portion, which is on a level with the patient's eyes, will be removed a greater distance from the patient's face than the mask portion that covers the patient's nose and mouth, that is the mask will be experienced to be moved further away from the face than has occurred in terms of function. This agrees well with the object of the invention. Moreover, the carrier device may comprise a support part to support the mask, and the support part is in a preferred embodiment connected to the outer mask part by pins, which are fixedly arranged on the mask and slid- ingly arranged in grooves in the support part. The grooves are preferably circular-arc-shaped with a centre of rotation coinciding with the centre of rotation of the mask when pivoted from the first use position to the second. This ensures simple, stable and reliable movement between the two use positions. The user is also spared undesirable forces, which could be exerted if the mask abuts against the patient's face. In the second use position, the mask may rest on the support part, which additionally reduces the action of forces when the mask abuts against the patient's face.

The mask may also comprise means for adjusting the position of the mask part relative to the support part. As a result, it will be possible to easily adjust the mask so as to fit a user's shape and size of face.

Brief Description of the Drawings

The invention will in the following be described in the form of non-limiting examples of preferred embodiments with reference to the accompanying pictures, of which

Fig. 1 is a side view partly in section of an inventive inhalation mask according to a first embodiment in a first use position, and,

Fig. 2 is a view corresponding to Fig. 1, but with the inhalation mask in a second use position.

Detailed Description of a Preferred Embodiment Fig. 1 illustrates a first embodiment of the present invention in a first use position. The inhalation mask 1, which for illustration purposes is placed on a user 2, comprises an inner mask part 3 with an edge 4, adapted in the first use position to abut against the patient's face, over his nose and mouth. The inner mask part 3 is in a conventional way connected by connecting means 5, 6, 7 to a gas inlet 8 and a gas exhaust means 9. A conduit 10 for introducing pharmaceutical preparations, which can be entrained by the inflowing gas, is connected to the connecting means 7 for the gas inlet.

The connecting means 7 comprises a demand valve, which ensures that inflowing gas is arranged when a negative pressure prevails in the inner mask part 3, and that extraction through the connecting means 5 occurs when a positive pressure prevails in the inner mask part 3. The exhaust means 9 is connected to a suitable exhaust device, as is well known to a person skilled in the art.

An outer mask part 11 is arranged around the inner mask part 3. The outer mask part 11 extends substantially from the edge 4 of the inner mask part 3 away from the user' s 2 face and defines a gap 12 between itself and the inner mask part 3. The outer mask part 11 is further sealingly connected to the gas exhaust means 9 to generate a negative pressure in the gap 12.

In this use position, breathing gas, optionally entraining a treatment gas, is administered through the gas inlet 8. The breathing gas may further, by means of the conduit 10, be supplied with a pharmaceutical preparation in aerosol form, powder form or the like. This pharmaceutical preparation is supplied at a carrier flow rate of about 5 1/min. As the user 2 exhales the inhaled gas mixture, it will be exhausted through the exhaust means 9, substantially through the connecting means 5 and discharged from the space in which the user 2 is positioned.

In the shown embodiment, a carrier device 13 is arranged under the user' s chin and attached to the user by means of a nape strap 14. The carrier device 13 is designed so as to rest softly on the user' s chin and neck. Moreover the carrier device comprises a support part 15 which extends substantially from the user's face, and upwardly extending grooves 16 to which the mask 1 is slidingly connected by pins 17 arranged on the mask or constituting a part thereof. The grooves 16 are formed in the support part 15 and consist of circular-arc-shaped grooves with an imaginary centre of rotation adjacent the lowermost portion of the inner mask part 3. The support part 15 is preferably made of a plastic material with a softer material arranged where it abuts against the patient. In this first use position, the mask 1 is held against the patient's face by the patient himself, by the treating personnel or in some other manner. By slidingly moving the mask 1 along the grooves 16, the mask 1 is pivoted about a pivot axis which substantially consists of the lowermost contact point of the inner mask part 3 on the user 2. After completion of the above-mentioned sliding/pivoting movement, the mask 1 rests on the support part 15 according to Fig. 2. In the shown embodiment, this takes place automatically as the patient releases the mask 1.

As is evident from Fig. 2, the mask 1 does not, in this second use position, substantially abut any longer against the user's 2 face. The mask is instead pivoted away from the user's face and rests on the support part 15. In this use position, the user can unimpededly communicate with the ambient personnel and feels less "shut in" than in the first use position. Because of the small weight of the mask, the embodiment illustrated weighs only about 300 g, it does not exert an uncomfortable load on the user. When changing from the first to the second use position, the demand valve has further shifted the exhaust flow from also flowing through the connecting means 5 to merely flowing through the gap 12 and out of the exhaust means 9. This means that such a great flow is arranged through the gap 12 that substantially all exhalation gas is exhausted therethrough, which means that it does not reach the ambient air and the ambient personnel. Moreover the demand valve blocks the gas supply to the mask, whereby the treatment of the patient, at least temporarily, is terminated and the function of the mask is aimed at taking care of the remaining exhaled pharmaceutical preparation/gas from the patient.

The mask parts 3, 11 are preferably made of a silicone material. According to a second embodiment (not shown) , the nape strap 14 comprises two straps in the form of elastic bands attached at one end to the support and at the other end by means of a loop, earpiece or the like around each of the patient's ears. The carrier device may, for instance, comprise a plurality of straps and the support part may be designed in a way other than described above. Furthermore, in a simpler embodiment the carrier device could be replaced by a nape strap which is attached directly to the lower portion of the mask. Nor does the space between the inner and the outer mask part have to be formed as a gap, but may have an arbitrary form that satisfies the purposes, for example, a plurality of tubes, holes, openings or the like, arranged along the periphery of the inner mask part. Moreover, it would be obvious to a person skilled in the art that the fact that only two use positions have been mentioned does not exclude that a plurality of, for example intermediary, use positions exist and that the movement between the use positions can also be performed in a manner other than described above, for example by pivoting about another axis, which could be vertical.

Claims

1. An inhalation mask (1) for administering gas and any pharmaceutical preparation entrained by the gas, to a user, comprising a cup-shaped inner mask part (3) with an edge (4) adapted, in a first use position, to abut against the user's (2) face, connected by connecting means (5, 6, 7) to a gas inlet (8) and a gas exhaust means (9) adapted to exhaust exhaled gas, further com- prising an outer mask part (11) which surrounds the inner mask part (3) and substantially extends from the edge (4) of the inner mask part (3) away from the user's (2) face and defines a gap (12) between itself and the inner mask part (3), the outer mask part (11) being connected to the gas exhaust means (9) for optionally generating a negative pressure in the gap (12) for exhausting the exhalation gas, c h a r a c t e r i s e d in that the inhalation mask (1) further comprises a carrier device (13) adapted to be arranged on the user and carry the mask (1) to enable at least a second use position in which the user's face is substantially released from the inner mask part (3) .

2. An inhalation mask as claimed in claim 1, further comprising a conduit (10) for administering pharmaceuti- cal preparations, preferably in gas, powder or aerosol form, connected to said gas inlet (8) .

3. An inhalation mask as claimed in claim 1 or 2, further comprising a shifting means to ensure that the main extraction of exhalation gas takes place through the connecting means (5) in the first use position and through the gap (12) in the second use position.

4. An inhalation mask as claimed in claim 3, in which the shifting means comprises a demand valve.

5. An inhalation mask as claimed in any one of the preceding claims, in which the mask (1) in the second use position is pivoted away from the user and abuts against the user with its lowermost portion only.

6. An inhalation mask as claimed in any one of the preceding claims, in which the carrier device (13) comprises a support part (15) for supporting the mask (1) .

7. An inhalation mask as claimed in claim 6, in which the support part (15) is connected to the outer mask part (11) by pins (17) which are fixedly arranged on the mask and slidingly arranged in grooves (16) in the support part .

8. An inhalation mask as claimed in claim 7, in which the grooves (16) are circular-arc-shaped with a centre of rotation coinciding with the centre of rotation of the mask (1) when pivoted from the first use position to the second.

9. An inhalation mask as claimed in any one of claims 6-8, in which the mask (1) in the second use position rests on the support part (15) .

10. An inhalation mask as claimed in any one of claims 6-9, wherein the mask comprises means for adjusting the distance between the support part (15) and the inner and the outer mask part (3, 11) to fit different head shapes.