WO1993000125A1

WO1993000125A1 - Tight face mask

Info

Publication number: WO1993000125A1
Application number: PCT/SE1992/000436
Authority: WO
Inventors: Lars Emil Torsten Ingvarsson
Original assignee: Nolato I Torekov Ab
Priority date: 1991-06-20
Filing date: 1992-06-17
Publication date: 1993-01-07
Also published as: SE9101909D0; SE468661B; SE9101909L

Abstract

Tightly fitting face mask, having one open side for application against the face of a person thereby surrounding the nose and the mouth of said person and delimiting a breathing chamber isolated from the surroundings. The face mask comprises a bowl-shaped housing (1), open at one side and provided with gas impervious limiting walls. The edge portion of said housing which delimits said opening forms a closed hollow profile (4) having flexible delimiting walls. The cavity of said hollow profile (4) is filled up with a particulate material (7) consisting of rigid, smooth particles (7) of a non-compressible material, preferably glass balls or hard plastic balls. Via a valve (6) the hollow section (4) may be connected to a device for evacuating air from the cavity in order to press the elastic limiting walls of said cavity against the enclosed particle mass (7) under the influence of the ambient pressure and thus fixing the form obtained by the particle mass (7) enclosed in the cavity obtained by pressing the mask against the face.

Description

TIGHT FACE MASK.

The present invention relates to a tightly fitting face mask for application to the face of a person for sur¬ rounding the nose and the mouth of said person, delimiting a breathing chamber isolated from the surroundings.

Face masks of this kind are previously known and are particularly used as breathing masks or narcosis masks in medical treatment. Narcosis masks generally used in medical treatment suffer from the disadvantage of not providing sufficient sealing effect against the skin which results in leakage of narcosis gas into the surroundings. In order to remedy the leakage problem it is also known to provide the narcosis mask with double limiting walls forming an evacua¬ tion slit at the bottom thereof. The space between the double walls is connected to an evacuation system for eva¬ cuating leaking gas. In addition to the fact that this nar¬ cosis mask is "clumsy" in shape and relatively difficult in application and use, it has not prooved to solve the leakage problem in a satisfactory way. In order to obtain a satisfactory sealing effect against the face of the pa¬ tient, the form of the abutting surface of the mask must be exactly adapted to the face. In order to obtain this US 2,887,764 proposes a face mask, the face abutting edge of which being formed as a ca¬ vity delimited by a thin, flexible wall. The cavity is filled up with a particulate material consisting of porous, eleastic particles of latex foam. The cavity wall is pro- vided with a valve which in open condition forms a connec¬ tion between the cavity and the surroundings, and in closed position blocks said connection.

With the valve in open position the mask is pressed against the face of the patient so that a complete abutment against the face contour can be assertained. The porous particles of latex foam, which during the pressing action will be displaced by protruding face contours, will then be compressed thereby expulsing the air content of the par¬ ticles, the displaced air being discharged through the valve into the surroundings. The valve is then closed re- suiting in that the shape of the contact surface against the face obtained by the pressing action is maintained. Since the particles included in the particulate mass en¬ closed in the cavity are elastically compressable, it is unavoidable that the particles will undergo a certain ex- pansion after closing off the valve.. This may result in that the contour adaption initially intended will be lost resulting in poor sealing action. If during the sequence of use the mask i removed and then replaced, it is necessary to make sure that the mask is pressed against the face with the same pressing force as when the mask initially was fitted, so that the contour adaption thus obtained will give a corresponding sealing effect when the mask is re¬ placed.

One problem in the use of narcosis masks, and which has not been solved in any of the known masks, is the leakage which can occur due to face movements, e.g. jaw movements, which may occur even if the patient is uncon¬ scious.

The object of the present invention is to provide a tightly fitting face mask of the kind mentioned initially, in which the disadvantages mentioned above and inherent in previously known face masks are avoided and which in a simple manner renders possible an exact adaption of the contact surface of the mask to the individual face con- figuration of the face of the wearer, and fixing the shape obtained when the mask is pressed against the face of the wearer. A further object of the invention is to provide a face mask ensuring the retained sealing effect also during face movements which may occur also when the wearer is un- conscious. According to the invention the objects mentioned above are obtained by a design of the face mask in ac¬ cordance with the appended claims.

The invention will be described below under the re- ference to the embodiments illustrated on the enclosed drawing. In the drawing fig 1 is a longitudinal sectional view through a face mask according to the invention, taken as indicated with arrows A-A in fig 2, fig 2 is a bottom view of the face mask according to fig 1, and fig 3 a modified embodiment of the face mask ac¬ cording to the invention.

The face mask shown in the figures comprises a bowl- shaped housing 1 which is open at one side and which may be constructed as a rigid plastic housing or as a relatively stiff rubber housing having a certain flexibility. The upper portion of the housing 1 is provided with a connec¬ tion piece 2 having a connection portion 3 for connecting a hose or a tube, not shown in the figures, from a gas source, e.g. oxygene or narcosis gas. A hollow section 4 extending around the housing is disposed at the open side of the housing 1, i.e. the side thereof situated opposit the connection piece 2, said hollow section delimiting said opening. The hollow section 4 is sealingly connected with the bowl-shaped housing 1 at the open side thereof and may be attached to the housing on its outside, as shown in fig 1 and 4, or may form a direct extension of the housing 1. The hollow section 4 is made of a thin, elastically flexible and tenacious material, preferably a latex foil of a thickness of 0,5-1 mm. The cross section of the hollow section 4 is varying around the opening of the housing 1 so that the lower edge of the hollow section 4 has a con¬ figuration which substantially corresponds to the face con- tour along the contact line between the hollow section 4 of the housing 1 and the face of a person having a normal face configuration. At one side the hollow section 4 is provided with a connection piece 5 protruding from the hollow sec¬ tion, and having a valve 6 fitted therein which in open po- sition connects the cavity with the surroundings and in closed position blocks said connection. The valve 6 pre¬ ferably consists of a check valve comprising a ball which is spring actuated against a seat, but may also be of any other design and may e.g. comprise laps or lips which are pressure actuated toward each other. The valve 6 is suit¬ ably so designed that it will open by introducing a connec¬ tion element, e.g. a connecting nipple for providing con¬ nection with a vacuum source, or a syringe or the like for evacuating air from the cavity 4. In accordance with the invention the cavity 4 is filled up with rigid, smooth particles of a non-com¬ pressible material, preferably smooth glass balls 7 or hard, smooth plastic balls. The balls 7, preferably of a diameter in the range of one millimetre, should as men- tioned be smooth and glossy so that they will slide easily with respect to each other and redistributed when the elastically flexible limiting wall of the cavity 4 is made subject to depressions.

Preferably the hollow section 4 on the underside thereof, i.e. the side thereof to be directed towards the face of the wearer, is provided with an endless, gas tight, soft and elastic gasket 8 which afterwards may be attached by vulcanization or which may be produced integral with the hollow section 4. This gasket, which may have various con- figurations, should provide the smallest possible re¬ sistance against deformation of the wall of the hollow sec¬ tion 4, and at the same time provide a satisfactory sealing against the skin of the face at the same time compensating for face movements which may occur also with an unconscious person. In use the mask is applied against the face of the user so that the mask surrounds the nose and mouth of the person, thereby delimiting a breathing chamber isolated from the surroundings. The mask is pressed against the face so that a complete contact against the skin of the face around the mask is obtained. A device for evacuating air, e.g. syringe of the type injection syringe, is then at¬ tached to the valve 6, after which air is evacuated until the wall of the hollow section 4 under the influence of the surrounding air pressure is being pressed against the ball mass 7 enclosed in the cavity. This will result in a fixa¬ tion of the position taken by the balls 7 with respect to each other when the mask is being pressed against the face, and thus a fixation of the form of the mask, carefully adapted to the face. The gaskets 8 disposed at the under- side of the hollow section 4 then will secure sealing against the face also during small movements of the face which may occur, e.g. face movements which may occur also with an unconscious person.

Fig 3 illustrates a modified embodiment of the face mask according to the invention. This variant differs from the embodiment shown in figures 1-3 only in that the par¬ ticle mass 7 enclosed in the cavity of the hollow section 4 is not in contact against the inner side of the cavity wall but is enclosed within a thin protective cover 9 in tight contact with the inner walls of the hollow section 4. Ac¬ cording to fig 3, which is a partial section corresponding to the right part of fig 1, the protective cover 9 has been indicated by broken lines and the ball-like particles 7 which completely fill up said cavity are indicated only partly. This modification is the preferred embodiment, par¬ ticularly in case the face mask shall be used as narcosis mask. The object of the protective cover 9 is to prevent, in case of rupture of the limiting wall of the hollow section 4, ball-like particles from flowing out of the hollow section and being inhaled by the person to which said mask is applied. Ruptures of the wall of the hollow section 4 may happen due to ageing phenomena which may occur in the material due to repeated sterilizing treatment of the narcosis mask in an autoclave. The protective cover 9 may e.g. consist of thin hose of cotton cloth having a mesh which is less than the dimen¬ sions of the smallest ball-like particle present in the particle mass 7. The periphery length of the hose section should be at least the same as the periphery length of the largest cross section of the hollow section 4, in order to secure complete contact with the inner walls of the cavity. The protective cover 9 is suitably introduced into the hollow section 4 in connection with the manuf cture of the mask, as well as the filling of the ball-like particle mass 7 into the cavity.

The invention is not limited to the embodiments shown and described but may be subject to variations within the scope of the appended claims. The face mask may e.g. be provided with a suction pump device integrated into the body of the face mask and being permanently connected with the cavity of the hollow section 4 via the valve 6, e.g. a compressible and inflatable bladder provided with a valve or a common suction pump of the membrane type or of the wobble type having a spring actuated flap. Such an inte- grated embodiment is particularly advantageous with such face masks in which the wearer himself should be able to carry out the necessary form adaption, e.g. oxygene masks, stack gas masks or gas masks used within the army.

Claims

1. Tightly fitting face mask having one open side for ap¬ plication againt the face of a person thereby surrounding the nose and the mouth of said person and delimiting a breathing chamber isolated from the surroundings, said face mask comprising a bowl-shaped housing (1) open at one side and having gas tight limiting walls, the edge portion of said housing delimiting said opening being formed as a closed hollow section (4) with elastic limiting walls, the cavity of said hollow section (4) being filled up with a particulate material (7) and connected with a valve (6) which in its open condition connects the cavity with the surroundings and in closed condition blocks said connec- tion, c h a r a c t e r i z e d in that the cavity of the hollow section (4) is filled up with rigid, smooth particles (7) of a non-compressible material and via said valve (6) connectable to a device for evacuating air from the cavity, in order to press the elastic limiting walls of the cavity against the enclosed particle mass (7) under the influence of the surrounding pressure and thus fixing the form obtained by the particle mass (7) enclosed in the cavity by pressing the mask against the face.

2. Face mask as claimed in claim 1, c h a r a c t e r i z e d in that said particles (7) con¬ sist of smooth balls of a non-compressible material, preferably glass balls or hard plastic balls.

3. Face mask as claimed in any of claims 1 or 2, c h a r a c t e r i z e d in that said particle mass (7) in said cavity is enclosed within a thin protective cover (9) in close contact with the inner walls of the hollow section (4) .

4. Face mask as claimed in any of the preceeding claims, c h a r a c t e r i z e d by an endless, gas tight, soft and elastic gasket (8) disposed on the outside of the limiting walls of the hollow cavity (4) for taking up face movements which may occur after attachment of said mask.

5. Face mask as claimed in any of .the preceeding claims, c h a r a c t e r i z e d by a connection piece (5) pro¬ truding from the limiting wall of the hollow section (4) having an openable valve (6) therein, said connection piece (5) being adapted for connection with a device for evacu¬ ating gas /air from the cavity.