WO1999021602A1

WO1999021602A1 - Face mask assembly

Info

Publication number: WO1999021602A1
Application number: PCT/SE1998/001946
Authority: WO
Inventors: Elna Berg; Magnus Jeppsson; Mark Milton-Edwards; Craig Nelson
Original assignee: Astrazeneca Ab
Priority date: 1997-10-27
Filing date: 1998-10-27
Publication date: 1999-05-06
Also published as: AU9772598A; SE9703913D0

Abstract

A face mask assembly, comprising an attachment member (2) for attachment to an inhalation device (4) and a housing (8) for supporting a sealing part (10) for providing a seal with the face of a user, wherein the housing (8) includes an inlet opening (49) through which a user in use inhales and is movably coupled to the attachment member (2) between an operative position and an inoperative position.

Description

FACE MASK ASSEMBLY

The present invention relates to a face mask assembly, in particular a face mask assembly for attachment to an inhalation device.

As inhalation devices many kinds of inhaler are known for providing medicaments to patients for inhalation. These inhalers include pressurised metered dose inhalers which are adapted on actuation to provide a metered dose of medicament as an aerosol spray and dry powder inhalers which are adapted to provide a metered dose of medicament as a dry powder in a channel for inhalation. EP-A-0237507 discloses one such dry powder inhaler.

The effective use of inhalers can, however, prove difficult to a number of patients, notably paediatric patients. With pressurised metered dose inhalers, this difficulty arises because effective operation of the inhaler requires a patient to actuate the inhaler at the onset of inhalation in order to draw the medicament deep into the lungs. Achieving this coordination is what is particularly difficult for paediatric patients. Typically, if the pressurised metered dose inhaler is actuated before the onset of inhalation most of the medicament will hit the back of the throat and if the pressurised metered dose inhaler is actuated after the onset of inhalation most of the medicament will remain in the throat or bronchial tracts and will have no effect. Dry powder inhalers, whilst not requiring such coordination of actuation and inhalation, also prove difficult to use to paediatric patients because those inhalers require a patient to inhale at a minimum rate in order to draw air through the inhaler. Paediatric patients in particular are not able to develop the necessary tidal volumes to achieve such flow rates.

In order to facilitate the use of such inhalers inhalation devices as spacers have been developed for use in combination therewith. Spacers comprise a relatively large chamber into which medicament is delivered from an inhaler. The medicament is contained in the chamber in a dispersed state and is thus more easily inhaled by a patient over several breaths. WO-A-95/20414 discloses a spacer for a pressurised metered dose inhaler. WO- A-97/11732 discloses a spacer for a dry powder inhaler.

Some patients, however, even have difficulty in using combined spacer and inhaler systems. Problems arise because patients have both to grip the mouthpiece of the spacer sufficiently firmly in his or her mouth to seal with the outer surface of the mouthpiece and co-ordinate his or her breathing so as to ensure that inhalation occurs through the mouth and not the nose. It thus becomes necessary to use a face mask to ensure that these patients inhale medicament from the spacer.

EP-A-0601708 discloses a face mask for an inhalation device such as a spacer. This face mask includes an inlet opening for attachment to an inhalation device and an outlet opening which includes an exhalation valve through which exhaled air is in use expelled.

US-A-5265595 discloses a face mask which includes isolated nose and mouth chambers for use in stress/exercise testing, metabolic measurements and pulmonary function studies. This face mask includes an inlet opening which includes an inhalation valve for allowing the free inhalation of air from the atmosphere and an outlet opening through which exhaled air is in use expelled to monitoring equipment.

The present invention aims to provide an improved face mask assembly for an inhalation device such as an inhaler or a spacer.

The present invention provides a face mask assembly, comprising an attachment member for attachment to an inhalation device and a housing for supporting a sealing part for providing a seal with the face of a user, wherein the housing includes an inlet opening through which a user in use inhales and is movably coupled to the attachment member between an operative position and an inoperative position.

Preferably, the attachment member and the housing are configured such that the housing is rotated relative to the attachment member in movement between the operative and inoperative positions.

Preferably, the attachment member and the housing are configured such that the housing is rotated and translated relative to the attachment member in movement between the operative and inoperative positions.

More preferably, the attachment member and the housing are configured such that in movement between the operative and inoperative positions the housing is extended and rotated relative to the attachment member.

Preferably, the attachment member includes at least one of one of a first projection or a first slot and at least one of one of a second projection or a second slot and the housing includes the other of the at least one first projection or first slot and the other of the at least one second projection or second slot, the at least one first projection being captively located in the at least one first slot and acting as a pivot mechanism and the at least one second projection being captively located in the at least one second slot and acting as a guide mechanism.

More preferably, the housing includes at least one arm which includes the other of the at least one first projection or first slot and the other of the at least one second projection or second slot. Yet more preferably, the housing includes first and second arms which each include the other of the first projection or first slot and the other of the second projection or second slot.

Still more preferably, the first and second arms extend over oppositely-directed surfaces of the attachment member.

In one embodiment the at least one second slot has a smooth continuous shape.

Preferably, the at least one second slot is arcuate in shape.

More preferably, the at least one second slot is substantially C-shaped.

In another embodiment the at least one second slot has at least two distinct sections.

Preferably, the at least one second slot is substantially L-shaped.

Preferably, one of the attachment member and the housing includes a resilient detent for engaging the other of the attachment member and the housing so as to hold the housing resiliently in the operative position.

Preferably, the attachment member includes an opening for viewing therethrough.

Preferably, the attachment member comprises a saddle portion.

Preferably, the housing includes a seal disposed around the inlet opening thereof for sealing, when attached, with the outer surface of a mouthpiece of the inhalation device. Preferably, the housing includes an outlet opening and an exhalation valve at the outlet opening through which a user in use exhales.

The provision of an exhalation valve allows a user to exhale without breaking the seal with his or her face. An exhalation valve may not be necessary where the inhalation device itself includes means to allow exhalation. However, the provision of an exhalation valve is nevertheless advantageous in preventing dispersed medicament in the dead space between the sealing part and the outlet of the inhalation device from being unnecessarily forced out and lost to the atmosphere.

Preferably, the housing includes one or more decorative features.

In this way, the face mask assembly can be made to look like different human or animal faces, which can be particularly fun for paediatric patients.

Preferably, the face mask assembly further comprises a sealing part attached to the housing for providing a seal with the face of a user.

More preferably, the sealing part includes a main seal for sealing around the mouth and nose of a user.

Yet more preferably, the main seal comprises an annular tubular member composed of a resilient material.

In one embodiment the tubular member is enclosed. In another embodiment the tubular member includes a plurality of venting orifices through which air is free to pass.

In a further embodiment the tubular member includes an opening which extends around a major part of the periphery thereof through which air is free to pass.

Preferably, the opening is a slot which extends around the entire periphery of the tubular member.

Preferably, the sealing part includes an annular bead which includes a peripheral channel in which the peripheral edge of the sealing part is located.

Where the sealing part is detachable the housing may very advantageously be used with a plurality of different sizes of sealing part. In this way, a plurality of sealing parts may be provided for use with a variety of different people. This is particularly advantageous for paediatric patients, where different size sealing parts may be provided for paediatric patients of different age.

More preferably, the peripheral channel includes at least one transverse rib which bridges the same and the peripheral edge of the housing includes at least one recess in which the at least one transverse rib is located so as to ensure correct relative orientation between the sealing part and the housing.

Preferably, the sealing part includes a bridging seal for sealing between the mouth and nose of a user and enclosing the nose of the user so as to prevent inhalation therethrough. In this way, an inhalation device can be placed in communication with the airways of a patient such as to ensure that inhalation occurs only through the mouth and that all inhaled air originates from the inlet opening in the housing and hence the inhalation device to which the face mask assembly is connected. This construction of the sealing part also provides a minimum dead space volume.

Preferably, the main seal and the bridging seal are integrally formed.

Preferably, the bridging seal is constructed as a solid band of a resilient material.

Preferably, the bridging seal includes a sealing flap which extends laterally along the length thereof so as to provide a sealing surface.

Preferably, the sealing part includes an inner nose housing integrally formed with the main seal and the bridging seal thereof which defines a chamber for enclosing the nose of the user so as to prevent inhalation therethrough.

The present invention also extends to an inhalation system comprising an inhalation device which includes a mouthpiece and the above-described face mask assembly, wherein the attachment member is configured to be a sliding fit to the mouthpiece and includes a resilient catch member which includes a detent for engaging a part of the inhalation device so as to lock the attachment member in position in relation to the mouthpiece.

The present invention further extends to an inhalation system comprising an inhalation device which includes a mouthpiece and a closure member and the above-described face mask assembly, wherein the mouthpiece is movable between a storage position in which an outlet of the mouthpiece is disposed adjacent a surface of the closure member and an operative position and the housing and the closure member are configured such that, with the attachment member attached to the mouthpiece, movement of the mouthpiece from the operative position to the storage position will cause the housing to be moved to the inoperative position.

Preferably, the attachment member is configured to be a sliding fit to the mouthpiece and includes a resilient catch member which includes a detent for engaging a part of the inhalation device so as to lock the attachment member in position in relation to the mouthpiece.

The present invention also provides an inhalation device including a mouthpiece and a face mask unit comprising a housing and a sealing part attached to the housing for providing a seal with the face of a user, wherein the housing includes an inlet opening through which a user in use inhales and is movable between an inoperative position an operative position in which an outlet of the mouthpiece is in communication with the inlet opening.

Preferably, the mouthpiece is movable between a storage position and an operative position and including a closure member adjacent a surface of which an outlet of the mouthpiece is disposed when the mouthpiece is in the storage position.

Preferably, the housing and the closure member are configured such that movement of the mouthpiece from the operative position to the storage position will cause the housing to be moved to the inoperative position.

Preferably, the housing is configured so as to be rotated in movement between the operative and inoperative positions. Preferably, the housing is configured so as to be rotated and translated in movement between the operative and inoperative positions.

More preferably, the housing is configured such that in movement between the operative and inoperative positions the housing is moved between a retracted operative position and an extended and rotated inoperative position.

Preferably, a surface of the inhalation device includes at least one of one of a first projection or a first slot and at least one of one of a second projection or a second slot and the housing includes the other of the at least one first projection or first slot and the other of the at least one second projection or second slot, the at least one first projection being captively located in the at least one first slot and acting as a pivot mechanism and the at least one second projection being captively located in the at least one second slot and acting as a guide mechanism.

More preferably, the housing includes at least one arm which includes the other of the at least one first projection or first slot and the other of the at least one second projection or second slot.

Yet more preferably, the housing includes first and second arms which each include the other of the first projection or first slot and the other of the second projection or second slot.

Still more preferably, the first and second arms extend over oppositely-directed surfaces of the inhalation device. Preferably, the inhalation device includes a resilient detent for holding the housing resiliently in the operative position.

Preferably, the housing includes a seal disposed around the inlet opening thereof for sealing with the outer surface of the mouthpiece.

Preferably, the housing includes an outlet opening and an exhalation valve at the outlet opening through which a user in use exhales.

Preferably, the housing includes one or more decorative features.

A preferred embodiment of the present invention will now be described hereinbelow by way of example only with reference to the accompanying drawings, in which:

Figure 1 illustrates in exploded view the component parts of a face mask assembly in accordance with a preferred embodiment of the present invention together with parts of an inhalation device;

Figure 2(a) illustrates a front view of the attachment member of the face mask assembly of Figure 1;

Figure 2(b) illustrates a plan view of the attachment member of Figure 2(a);

Figure 2(c) illustrates an underneath plan view of the attachment member of Figure 2(a);

Figure 2(d) illustrates a side view of the attachment member of Figure 2(a); Figure 2(e) illustrates a vertical sectional view (along section I-I in Figure 2(b)) of the attachment member of Figure 2(a);

Figure 3(a) illustrates a front view of the main body of the housing of the face mask assembly of Figure 1 ;

Figure 3(b) illustrates a rear view of the main body of Figure 3(a);

Figure 3(c) illustrates a plan view of the main body of Figure 3(a);

Figure 3(d) illustrates an underneath plan view of the main body of Figure 3(a);

Figure 3(e) illustrates a side view of the main body of Figure 3(a);

Figure 3(f) illustrates a vertical sectional view (along section II-II in Figure 3(d)) of the main body of Figure 3(a);

Figure 3(g) illustrates in part the view of Figure 3(f) in enlarged scale;

Figure 3(h) illustrates a horizontal sectional view (along section III-III in Figure 3(e)) of the main body of Figure 3(a);

Figures 4(a) and (b) illustrate respectively plan and side views of the mouthpiece seal of the housing of the face mask assembly of Figure 1 ;

Figure 5(a) illustrates a front view of the cover member of the exhalation valve of the housing of the face mask assembly of Figure 1 ; Figure 5(b) illustrates a rear view of the cover member of Figure 5(a);

Figure 5(c) illustrates a plan view of the cover member of Figure 5(a);

Figure 5(d) illustrates an underneath plan view of the cover member of Figure 5(a);

Figure 5(e) illustrates a side view of the cover member of Figure 5(a);

Figure 5(f) illustrates a vertical sectional view (along section IV-IV in Figure 5(b)) of the cover member of Figure 5(a);

Figures 6(a) and (b) illustrate respectively plan and side views of the valve flap of the exhalation valve of the housing of the face mask assembly of Figure 1 ;

Figure 7(a) illustrates a front perspective view of the sealing part of the face mask assembly of Figure 1 ;

Figure 7(b) illustrates a rear perspective view of the sealing part of Figure 7(a);

Figure 7(c) illustrates a front view of the sealing part of Figure 7(a);

Figure 7(d) illustrates a vertical sectional view (along section V-V in Figure 7(c)) of the sealing part of Figure 7(a);

Figure 7(e) illustrates a horizontal sectional view (along section VI- VI in Figure 7(c)) of the sealing part of Figure 7(a); Figure 7(f) illustrates a horizontal sectional view (along section VII- VII in Figure 7(c)) of the sealing part of Figure 7(a);

Figure 8 illustrates in the operative configuration a side view of the face mask assembly of Figure 1 attached to an inhalation device;

Figure 9 illustrates in the storage configuration a side view of the face mask assembly of Figure 1 attached to an inhalation device;

Figure 10 illustrates in the operative configuration a vertical sectional view of the attachment member and the housing of the face mask assembly of Figure 1 ;

Figure 1 1 illustrates in the storage configuration a vertical sectional view of the attachment member and the housing of the face assembly of Figure 1 ;

Figure 12(a) illustrates a front perspective view of a modified sealing part for the face mask assembly of Figure 1 ;

Figure 12(b) illustrates a rear perspective view of the sealing part of Figure 12(a);

Figure 12(c) illustrates a front view of the sealing part of Figure 12(a);

Figure 12(d) illustrates a vertical sectional view (along section VIII- VIII in Figure 12(c)) of the sealing part of Figure 12(a); Figure 12(e) illustrates a horizontal sectional view (along section IX-IX in Figure 12(c)) of the sealing part of Figure 12(a);

Figure 12(f) illustrates a horizontal sectional view (along section X-X in Figure 12(c)) of the sealing part of Figure 12(a);

Figure 13 illustrates a rear perspective view of a modified main body for the housing of the face mask assembly of Figure 1 ; and

Figure 14 illustrates a rear perspective view of a further modified main body for the housing of the face mask assembly of Figure 1.

The face mask assembly comprises three main components, namely, an attachment member 2 for attaching the face mask assembly to an inhalation device 4, in this embodiment to the mouthpiece 6 of the inhalation device 4, a housing 8 which is pivotally coupled to the attachment member 2 and a sealing part 10 which is attached to the housing 8 for sealing against the face of a user.

The attachment member 2 comprises a saddle portion which is fitted over the mouthpiece 6 of the inhalation device 4. In this embodiment the attachment member 2 is formed of a relatively rigid plastics material, such as a polycarbonate.

The attachment member 2 includes at least one inwardly and upwardly extending flange 12 at each opposed lower edge thereof, which flanges 12 are configured so as to slide into and along axially aligned channels 14 in the mouthpiece 6 of the inhalation device 4. In this embodiment the flanges 12 on the attachment member 2 and the channels 14 in the mouthpiece 6 of the inhalation device 4 have an asymmetric cross-section such that when the attachment member 2 is fitted to the mouthpiece 6 of the inhalation device 4 the attachment member 2 is held rotationally secure.

The attachment member 2 further includes at the upper, rear end thereof a rearwardly- extending resilient catch member 16 which is downwardly biased so as to abut the upper surface of the inhalation device 4 when the attachment member 2 is fitted thereto. The catch member 16 includes a detent 18 on the lower surface thereof which engages in a recess 20 in the upper surface of the inhalation device 4 so as to lock the attachment member 2 in position in relation to the inhalation device 4. Thus, in use, the attachment member 2 is slid onto the mouthpiece 6 of the inhalation device 4 until the detent 18 on the lower surface of the catch member 16 is located in the recess 20 in the upper surface of the inhalation device 4. In order to remove the attachment member 2 and hence the face mask assembly, the catch member 16 must first be resiliently lifted away from the upper surface of the inhalation device 4 so as to release the detent 18 on the lower surface of the catch member 16 from the recess 20 in the upper surface of the inhalation device 4 and allow the attachment member 2 to be slid off the mouthpiece 6 of the inhalation device 4.

The attachment member 2 yet further includes an opening 22 in the upper surface thereof which is configured such that, when the attachment member 2 is fitted to the mouthpiece 6 of the inhalation device 4, the opening 22 exposes a part of the upper surface of the mouthpiece 6 of the inhalation device 4. The opening 22 serves the purpose, where the mouthpiece 6 of the inhalation device 4 is formed of a transparent, translucent or at least partly translucent material and includes an internal flap valve, of allowing the flap valve to be observed and thereby ensure that in use air is being inhaled through the inhalation device 4. The attachment member 2 still further includes first and second outwardly extending projections 24, 26, in this embodiment in the form of pins, on each side thereof, with the first projections 24 acting as pivot points and the second projections 26 acting as guide points for coupling the attachment member 2 to the housing 8 as will be described in further detail hereinbelow. Each of the pairs of the first and second projections 24, 26 are oppositely disposed.

The attachment member 2 still yet further includes at the upper, forward end thereof an upwardly extending resilient detent 28 which, as will be described in further detail hereinbelow, is adapted to engage the housing 8 in the operative configuration of the face mask assembly.

The housing 8 comprises a main body 30 which is coupled to the attachment member 2, a mouthpiece seal 32 for sealing against the outer surface of the mouthpiece 6 of the inhalation device 4, and an exhalation valve 34 through which exhaled air is in use expelled.

The main body 30 of the housing 8 comprises a rear section 36 by which the housing 8 is coupled to the attachment member 2 and an open front section 38 of generally concave form for receiving the sealing part 10 about the peripheral edge thereof. In this embodiment the main body 30 of the housing 8 is made from a relatively rigid plastics material, such as a polycarbonate, thereby providing adequate support for the sealing part 10.

The rear section 36 of the main body 30 includes rearwardly extending first and second arms 40, 42 which each include first and second slots 44, 46 in the inwardly facing and opposed surfaces thereof, with the pivot projections 24 on the attachment member 2 being captively located in the respective first slots 44 and the guide projections 26 on the attachment member 2 being captively located in the respective second slots 46. The first, pivot slots 44 each define a path having first and second end points 44', 44" spaced along the length of the respective first and second arms 40, 42 of the rear section 36 of the main body 30 so as to provide for translational movement of the housing 8 relative to the attachment member 2. The second, guide slots 46 each define a path having first and second end points 46', 46" spaced both along the length and the height of the respective first and second arms 40, 42 of the rear section 36 of the main body 30 so as to provide for both translational and rotational movement of the housing 8 relative to the attachment member 2. As will be apparent, the one of the pivot and guide slots 44, 46 with the shorter lengthwise spacing between the end points 44', 46', 44", 46" thereof determines the limit of the translational movement of the housing 8 relative to the attachment member 2 and the heightwise spacing between the first and second end points 46', 46" of the guide slots 46 determines the limit of the rotational movement of the housing 8 relative to the attachment member 2. In this embodiment the pivot slots 44 are linear slots extending substantially parallel to the longitudinal axis of the rear section 36 of the main body 30 and the guide slots 46 are substantially L-shaped, with a first section 46a of each guide slot 46 extending from a position near the lower edge of the respective one of the first and second arms 40, 42 of the rear section 36 of the main body 30 substantially orthogonally to the longitudinal axis of the rear section 36 of the main body 30 and a second section 46b of each guide slot 46 extending forwardly from the upper end of the first section 46a of the respective guide slot 46 substantially parallel to the longitudinal axis of the rear section 36 of the main body 30. The provision of the guide slots 46 with at least two distinct sections, such as an L shape, ensures a more distinct transition between the translational and rotational movement of the housing 8 relative to the attachment member 2. It will, of course, be appreciated that the pivot slots 44 and the guide slots 46 could take numerous alternative shapes, depending upon the precise movement of the housing 8 which is required. For instance, the guide slots 46 could be provided with a smooth, continuous shape, such as an arcuate shape and preferably a C shape. The provision of the guide slots 46 with a smooth shape provides for a combined translational and rotational movement of the housing 8 relative to the attachment member 2. In this embodiment the pivot slots 44 and the guide slots 46 are blind slots so as to be concealed, but the pivot slots 44 and the guide slots 46 could equally be through slots.

The rear section 36 of the main body 30 further includes a support member 47 which interconnects the first and second arms 40, 42 thereof. The support member 47 includes a recess 48 in the lower surface of the rear edge thereof for receiving the detent 28 on the attachment member 2 when the housing 8 is in the operative position (see Figure 10) so as to hold the face mask assembly in the operative configuration. In this embodiment the detent 28 on the attachment member 2 and the recess 48 in the support member 47 of rear section 36 of the main body 30 are of an appropriate shape and size such that, upon applying a relatively small force to move the housing 8 from the operative position, the detent 28 will ride up and out of the recess 48 in the support member 47 and release the housing 8 from the operative position.

The front section 38 of the main body 30 includes a first, inlet opening 49 for providing communication with the mouthpiece 6 of the inhalation device 4 and a second, outlet opening 50 for allowing the escape of exhaled air to the atmosphere. The outlet opening 50 includes a centrally located collar 52 which is supported by a plurality of radially extending webs 54, which collar 52 includes a through-hole 56 for receiving part of the exhalation valve 34 as will be described in detail hereinbelow.

The front section 38 of the main body 30 further includes a notch 58 in the peripheral edge thereof to which the sealing part 10 is attached. As will be described hereinbelow, the notch 58 is configured to receive a part of the sealing part 10 so as to ensure that the sealing part 10 is fitted to the main body 30 in the correct orientation.

The mouthpiece seal 32 of the housing 8 is secured around the inlet opening 49 in the front section 38 of the main body 30 of the housing 8, in this embodiment by an adhesive. The mouthpiece seal 32 comprises a sheet of a resilient material, such as a thermoplastic elastomer, preferably a styrene based elastomer, and includes an opening 60 which is smaller than the inlet opening 49 in the front section 38 of the main body 30. In this way, when the mouthpiece 6 of the inhalation device 4 is partially inserted into the opening 60 in the mouthpiece seal 32 the mouthpiece seal 32 will come into contact and seal against the outer surface of the mouthpiece 6 of the inhalation device 4. As illustrated in Figure 10, the mouthpiece seal 32 is, in the operative position of the housing 8, angled so as to enclose an acute angle with respect to a direction normal to the longitudinal axis of the attachment member 2. By providing this slight downwardly facing angle, the removal of the mouthpiece 6 of the inhalation device 4 from the mouthpiece seal 32 is facilitated.

The exhalation valve 34 of the housing 8 comprises a valve flap 62 located at the outlet side of the outlet opening 50 in the main body 30 of the housing 8 and a cover member 64 covering the valve flap 62 so as to protect the same from damage.

The valve flap 62 of the exhalation valve 34 is located at the outlet side of the outlet opening 50 in the main body 30 of the housing 8 such that, upon inhalation by a user, the valve flap 62 will be drawn against the main body 30 and seal thereagainst so as to prevent air being inhaled through the outlet opening 50 in the main body 30, and, upon exhalation by a user, the valve flap 62 will be forced away from the main body 30 so as to allow exhaled air to be expelled through the outlet opening 50 in the main body 30. In this embodiment the valve flap 62 is formed of a silicone rubber. It will, of course, be appreciated that other forms of valve may be used to prevent air being inhaled through the outlet opening 50 in the main body 30 of the housing 8. The valve flap 62 includes a central opening 66 which is located adjacent the opening 56 in the collar 52 in the outlet opening 50 in the main body 30 of the housing 8.

The cover member 64 of the exhalation valve 34 comprises a substantially planar member 68 which includes a plurality of apertures 70 therein, a flange 72 extending from one of the major surfaces of the planar member 68 about the peripheral edge thereof such that, when the cover member 64 is disposed adjacent the outlet opening 50 in the main body 30 of the housing 8, a chamber is defined at the outer surface of the main body 30 in which the valve flap 62 is received, and a pin 74 which extends from the one of the major surfaces of the planar member 68 and passes through the opening 56 in the collar 52 in the outlet opening 50 in the main body 30 and the opening 66 in the valve flap 62 so as to fix the same in position. In this embodiment the pin 74 is held in the opening 56 in the collar 52 in the outlet opening 50 in the main body 30 of the housing 8, typically by heat staking or an adhesive. In this embodiment the cover member 64 is formed of a relatively hard plastics material, such as a polycarbonate.

The sealing part 10 comprises an annular bead 76 by which the sealing part 10 is attached to the housing 8, a main seal 78 for sealing against the face of a user around his or her mouth and nose, a bridging seal 80 for sealing against the face of the user between his or her mouth and nose and an inner nose housing 82 for enclosing the nose of the user so as to prevent inhalation therethrough. In this embodiment the sealing part 10 is formed as a single injection moulded component of elastomeric material, such as a thermoplastic elastomer, preferably a styrene based elastomer, typically by a gas-injection moulding technique. In this embodiment the sealing part 10 is detachably mounted to the main body 30 of the housing 8 so as to allow for the removal for, for example, cleaning purposes. Furthermore, in being detachable a variety of shapes and/or sizes of sealing part 10 can be provided for use with the same housing 8. It will, of course, be appreciated that the sealing part 10 could be permanently fixed to the main body 30 of the housing 8.

The annular bead 76 of the sealing part 10 includes a peripheral channel 84 into which the peripheral edge of the front section 38 of the main body 30 of the housing 8 is located. In this embodiment the peripheral channel 84 includes a transverse rib 86 which bridges the same and is adapted to be received by the notch 58 in the peripheral edge of the front section 38 of the main body 30 of the housing 8 so as to ensure the correct relative orientation between the sealing part 10 and the housing 8.

The main seal 78 of the sealing part 10 comprises an annular tubular member 88 which defines an annular chamber 90. In this embodiment the tubular member 88 of the main seal 78 includes one or more small venting orifices 92 which connect the annular chamber 90 to the atmosphere. In an alternative embodiment the tubular member 88 of the main seal 78 could be totally enclosed and contain a gas, typically air, at a predetermined pressure. The material and thickness of the main seal 78 are selected such that the tubular member 88 thereof will relatively easily be deformed upon application to the face of a user, but will easily return to the tubular shape. The tubular air-filled form is particularly advantageous in providing a relatively large seal which deforms relatively easily to match the contours of the face of a user.

The bridging seal 80 of the sealing part 10 comprises a solid band which extends between lateral sections of the main seal 78 so as to define oral and nasal zones. In providing the bridging seal 80 as a solid band, which is preferably moulded from the same elastomeric material as the main seal 78, the bridging seal 80, which is unsupported from behind, has improved rigidity and furthermore is considerably easier to manufacture than if provided as a tubular member formed integrally with the main seal 78. The bridging seal 80 includes a curved sealing flap 94 at the forward edge thereof so as to provide a sealing surface for sealing against the face of a user. In a preferred embodiment the sealing flap 94 is formed so as to be thinner and hence more flexible than the remainder of the bridging seal 80 and thereby more closely follow the contours of the face of a user.

The inner nose housing 82 comprises a cup-shaped portion which is bounded by and joined to the main seal 78 and the bridging seal 80. As mentioned above, the inner nose housing 82 encloses the nose of the user so as to prevent inhalation therethrough and ensure that inhalation occurs, as desired, only through the mouth. In this embodiment the inner nose housing 82 is formed integrally with the main seal 78 and the bridging seal 80.

As illustrated in Figures 8 and 9, the face mask assembly finds particular application in relation to an inhalation device 4 which includes a mouthpiece 6 which is movable between a storage position and an operative position, such as a spacer for a dry powder inhaler as described in the above-mentioned WO-A-97/11732. The inhalation device 4 includes a closure member 98 which includes a sealing surface 100 against which the opening of the mouthpiece 6 of the inhalation device is located when in the storage position.

In use, with the mouthpiece 6 of the inhalation device 4 moved, in this embodiment raised, from the storage position, the attachment member 2 of the face mask assembly can be slid onto the mouthpiece 6 of the inhalation device 4 until the detent 18 on the lower surface of the catch member 16 on the attachment member 2 engages in the recess 20 in the upper surface of the inhalation device 4 so as to lock the attachment member 2 in position in relation to the inhalation device 4. With the attachment member 2 so attached, by virtue of the pivotal coupling between the housing 8 of the face mask assembly and the attachment member 2, the housing 8 is movable between one of the operative position as illustrated in Figure 8 and the storage position as illustrated in Figure 9. In the operative position the sealing part 10 of the face mask assembly is in fluid communication with only the outlet of the mouthpiece 6 of the inhalation device4 so as to allow for effective use of the inhalation device 4. In the storage position the housing 8 is rotated relative to the attachment member 2 sufficiently such that the mouthpiece 6 of the inhalation device 4 can be returned, in this embodiment lowered, to the storage position in which the outlet of the mouthpiece 6 is closed by the sealing surface 100 of the closure member 98 of the inhalation device 4. Indeed, as in this embodiment, with an appropriate shaping of the guide slots 46 in the arms 40, 42 of the rear section 36 of the main body 30 of the housing 8, the housing 8 can caused to be moved automatically to the storage position on returning the mouthpiece 6 of the inhalation device 4 to the storage position as a result of contact between the closure member 98 and the housing 8.

Figures 12 (a) to (f) illustrate a modified sealing part 10 for the above-described face mask assembly. Structurally, this sealing part 10 has many features in common with the above- described sealing part 10. For this reason, and in order to avoid unnecessary duplication of description, only the structural differences will be described and reference is made to the preceding description of the sealing part 10. This sealing part 10 differs from the above- described sealing part 10 in that the main seal 78 includes a continuous peripheral opening 102 through which air can pass. Likewise with the above-described sealing part 10, the open tubular form of the main seal 78 of this sealing part 10 is advantageous in providing a relatively large seal which deforms relatively easily to match the contours of the face of a user.

Referring to Figures 13 to 14, it will be seen that decorative features 104, such as the faces of animals, may be fixed to the main body 30 of the housing 8 of the face mask assembly so as to encourage use by paediatric patients. Such decorative features 104 may be secured with removable self-adhesive portions or with appropriately located clips. For instance, the housing 8 may include lips or recesses for receiving resilient prongs on the decorative features 104 or may conversely include resilient prongs for engaging lips or recesses in the decorative features 104.

Finally, it will be understood that the present invention is not restricted to the described embodiment but can be modified in many different ways without departing from the scope of the appended claims.

In one instance, in the described embodiment the pivot and guide pins 24, 26 are provided on the attachment member 2 and the pivot and guide slots 44, 46 are provided in the main body 30 of the housing 8. However, in an alternative embodiment the pivot and guide pins 24, 26 could be provided on the main body 30 of the housing 8 and the pivot and guide slots 44, 46 could be provided in the attachment member 2.

In another instance, in the described embodiment the translational and rotational movement of the housing 8 relative to the attachment member 2 is in a single plane. It will be appreciated, however, that the translational and rotational movement of the housing 8 need not be in a single plane relative to the attachment member 2, but rather the housing 8 could be arranged to rotate to one side of the attachment member 2.

Claims

1. A face mask assembly, comprising an attachment member (2) for attachment to an inhalation device (4) and a housing (8) for supporting a sealing part (10) for providing a seal with the face of a user, wherein the housing (8) includes an inlet opening (49) through which a user in use inhales and is movably coupled to the attachment member (2) between an operative position and an inoperative position.

2. The face mask assembly according to claim 1 , wherein the attachment member (2) and the housing (8) are configured such that the housing (8) is rotated relative to the attachment member (2) in movement between the operative and inoperative positions.

3. The face mask assembly according to claim 1, wherein the attachment member (2) and the housing (8) are configured such that the housing (8) is rotated and translated relative to the attachment member (2) in movement between the operative and inoperative positions.

4. The face mask assembly according to claim 3, wherein the attachment member (2) and the housing (8) are configured such that in movement between the operative and inoperative positions the housing (8) is extended and rotated relative to the attachment member (2).

5. The face mask assembly according to claim 3 or 4, wherein the attachment member (2) includes at least one of one of a first projection (24) or a first slot (44) and at least one of one of a second projection (26) or a second slot (46) and the housing (8) includes the other of the at least one first projection (24) or first slot (44) and the other of the at least one second projection (26) or second slot (46), the at least one first projection (24) being captively located in the at least one first slot (44) and acting as a pivot mechanism and the at least one second projection (26) being captively located in the at least one second slot (46) and acting as a guide mechanism. ^Γûá

6. The face mask assembly according to claim 5, wherein the housing (8) includes at least one arm (40, 42) which includes the other of the at least one first projection (24) or first slot (44) and the other of the at least one second projection (26) or second slot (46).

7. The face mask assembly according to claim 6, wherein the housing (8) includes first and second arms (40, 42) which each include the other of the first projection (24) or first slot (44) and the other of the second projection (26) or second slot (46).

8. The face mask assembly according to claim 7, wherein the first and second arms (40, 42) extend over oppositely-directed surfaces of the attachment member (2).

9. The face mask assembly according to any of claims 5 to 8, wherein the at least one second slot (46) has a smooth continuous shape.

10. The face mask assembly according to claim 9, wherein the at least one second slot (46) is arcuate in shape.

1 1. The face mask assembly according to claim 10, wherein the at least one second slot (46) is substantially C-shaped.

12. The face mask assembly according to any of claims 5 to 8, wherein the at least one second slot (46) has at least two distinct sections (46a, 46b).

13. The face mask assembly according to claim 12, wherein the at least one second slot (46) is substantially L-shaped.

14. The face mask assembly according to any of claims 1 to 13, wherein one of the attachment member (2) and the housing (8) includes a resilient detent (28) for engaging the other of the attachment member (2) and the housing (8) so as to hold the housing (8) resiliently in the operative position.

15. The face mask assembly according to any of claims 1 to 14, wherein the attachment member (2) includes an opening (22) for allowing viewing therethrough.

16. The face mask assembly according to any of claims 1 to 15, wherein the attachment member (2) comprises a saddle portion.

17. The face mask assembly according to any of claims 1 to 16, wherein the housing (8) includes a seal (32) disposed around the inlet opening (49) thereof for sealing, when attached, with the outer surface of a mouthpiece (6) of the inhalation device (4).

18. The face mask assembly according to any of claims 1 to 17, wherein the housing (8) includes an outlet opening (50) and an exhalation valve (34) at the outlet opening (50) through which a user in use exhales.

19. The face mask assembly according to any of claims 1 to 18, wherein the housing (8) includes one or more decorative features (104).

20. The face mask assembly according to any of claims 1 to 19, further comprising a sealing part (10) attached to the housing (8) for providing a seal with the face of a user.

21. The face mask assembly according to claim 20, wherein the sealing part (10) includes a main seal (78) for sealing around the mouth and nose of a user.

22. The face mask assembly according to claim 21, wherein the main seal (78) comprises an annular tubular member (88) composed of a resilient material.

23. The face mask assembly according to claim 22, wherein the tubular member (88) is enclosed.

24. The face mask assembly according to claim 22, wherein the tubular member (88) includes a plurality of venting orifices (92) through which air is free to pass.

25. The face mask assembly according to claim 22, wherein the tubular member (88) includes an opening (102) which extends around a major part of the periphery thereof through which air is free to pass.

26. The face mask assembly according to claim 25, wherein the opening (102) is a slot which extends around the entire periphery of the tubular member (88).

27. The face mask assembly according to any of claims 20 to 26, wherein the sealing part (10) includes an annular bead (76) which includes a peripheral channel (84) in which the peripheral edge of the sealing part (10) is located.

28. The face mask assembly according to claim 27, wherein the peripheral channel (84) includes at least one transverse rib (86) which bridges the same and the peripheral edge of the housing (8) includes at least one recess (58) in which the at least one transverse rib (86) is located so as to ensure correct relative orientation between the sealing part (10) and the housing (8).

29. The face mask assembly according to any of claims 20 to 28, wherein the sealing part (10) includes a bridging seal (80) for sealing between the mouth and nose of a user and enclosing the nose of the user so as to prevent inhalation therethrough.

30. The face mask assembly according to claim 29, wherein the main seal (78) and the bridging seal (80) are integrally formed.

31. The face mask assembly according to claim 29 or 30, wherein the bridging seal (80) is constructed as a solid band of a resilient material.

32. The face mask assembly according to any of claims 29 to 31 , wherein the bridging seal (80) includes a sealing flap (94) which extends laterally along the length thereof so as to provide a sealing surface.

33. The face mask assembly according to any of claims 29 to 32, wherein the sealing part (10) includes an inner nose housing (82) integrally formed with the main seal (78) and the bridging seal (80) thereof which defines a chamber for enclosing the nose of the user so as to prevent inhalation therethrough.

34. An inhalation system comprising an inhalation device (4) which includes a mouthpiece (6) and the face mask assembly according to any of claims 1 to 33, wherein the attachment member (2) is configured to be a sliding fit to the mouthpiece (6) and includes a resilient catch member (16) which includes a detent (18) for engaging a part (20) of the inhalation device (4) so as to lock the attachment member (2) in position in relation to the mouthpiece (6).

35. An inhalation system comprising an inhalation device (4) which includes a mouthpiece (6) and a closure member (98) and the face mask assembly according to any of claims 1 to 33, wherein the mouthpiece (6) is movable between a storage position in which an outlet of the mouthpiece (6) is disposed adjacent a surface (100) of the closure member (98) and an operative position and the housing (8) and the closure member (98) are configured such that, with the attachment member (2) attached to the mouthpiece (6), movement of the mouthpiece (6) from the operative position to the storage position will cause the housing (8) to be moved to the inoperative position.

36. The inhalation system according to claim 35, wherein the attachment member (2) is configured to be a sliding fit to the mouthpiece (6) and includes a resilient catch member (16) which includes a detent (18) for engaging a part (20) of the inhalation device (4) so as to lock the attachment member (2) in position in relation to the mouthpiece (6).

37. An inhalation device including a mouthpiece (6) and a face mask unit comprising a housing (8) and a sealing part (10) attached to the housing (8) for providing a seal with the face of a user, wherein the housing (8) includes an inlet opening (49) through which a user in use inhales and is movable between an inoperative position and an operative position in which an outlet of the mouthpiece (6) is in communication with the inlet opening (49).

38. The inhalation device according to claim 37, wherein the mouthpiece (6) is movable between a storage position and an operative position and including a closure member (98) adjacent a surface (100) of which an outlet of the mouthpiece (6) is disposed when the mouthpiece (6) is in the storage position.

39. The inhalation device according to claim 37 or 38, wherein the housing (8) and the closure member (98) are configured such that movement of the mouthpiece (6) from the operative position to the storage position will cause the housing (8) to be moved to the inoperative position.

40. The inhalation device according to any of claims 37 to 39, wherein the housing (8) is configured so as to be rotated in movement between the operative and inoperative positions.

41. The inhalation device according to any of claims 37 to 39, wherein the housing (8) is configured so as to be rotated and translated in movement between the operative and inoperative positions.

42. The inhalation device according to claim 41, wherein the housing (8) is configured such that in movement between the operative and inoperative positions the housing (8) is moved between a retracted operative position and an extended and rotated inoperative position.

43. The inhalation device according to claim 41 or 42, wherein a surface of the inhalation device includes at least one of one of a first projection (24) or a first slot (44) and at least one of one of a second projection (26) or a second slot (46) and the housing (8) includes the other of the at least one first projection (24) or first slot (44) and the other of the at least one second projection (26) or second slot (46), the at least one first projection (24) being captively located in the at least one first slot (44) and acting as a pivot mechanism and the at least one second projection (26) being captively located in the at least one second slot (46) and acting as a guide mechanism.

44. The inhalation device according to claim 43, wherein the housing (8) includes at least one arm (40, 42) which includes the other of the at least one first projection (24) or first slot (44) and the other of the at least one second projection (26) or second slot (46).

45. The inhalation device according to claim 44, wherein the housing (8) includes first and second arms (40, 42) which each include the other of the first projection (24) or first slot (44) and the other of the second projection (26) or second slot (46).

46. The inhalation device according to claim 45, wherein the first and second arms (40. 42) extend over oppositely-directed surfaces of the inhalation device.

47. The inhalation device according to any of claims 37 to 46, including a resilient detent (28) for holding the housing (8) resiliently in the operative position.

48. The inhalation device according to any of claims 37 to 47, wherein the housing (8) includes a seal (32) disposed around the inlet opening (49) thereof for sealing with the outer surface of the mouthpiece (6).

49. The inhalation device according to any of claims 37 to 48, wherein the housing (8) includes an outlet opening (50) and an exhalation valve (34) at the outlet opening (50) through which a user in use exhales.

50. The inhalation device according to any of claims 37 to 49, wherein the housing (8) includes one or more decorative features (104).