INHALER WITH COLLAPSIBLE CHAMBER

Abstract: Respiratory apparatus (1) for use in an inhaler system comprising a first member including a mouthpiece (4) attachment; a second member including a means for introducing a substance into said apparatus (1); and, mounted therebetween, at least one collapsible chamber (2) whereby said members can be gripped and moved with respect to one another so as to wholly or partly erect or collapse said chamber (2).

Description: INHALER WITH COLLAPSIBLE CHAMBER The invention relates to respiratory apparatus and methods of therapeutic agent delivery and, particularly but not exclusively, to respiratory apparatus for use in an inhaler system. Conventional hand-held pocket sized inhalers, in which a pressurised canister having a release valve is compressed so as to open the valve and direct a therapeutic substance and propellent at high speed into the mouth of a patient, have been known and used for many years. Such inhalers are simple to use and easy to transport. In addition, it is known that such inhalers may be advantageously supplemented by the use of a dispersion chamber or spacer to distribute and reduce the speed of the therapeutic substance before inhaling. In order to achieve this and to cater for a range of patients having different needs and requiring differing doses, dispersion chambers or spacers of differing lengths and/or volumes have been developed. For example, volumetric spacers or dispersion chambers comprising two rigid cups or frusto-conical members typically releasably joined at their respective bases or rims and having an opening for an inhaler at one end and a mouth piece at the other end, have been developed. However, such spacers are bulky to store and often very difficult to assemble particularly for young or elderly patients. In addition, conventional spacers have presented a number of problems in respect of therapeutic agent aerosol dispersion and therapeutic agent delivery within the spacer. In particular, efficient and accurate dispersion and diffusion of therapeutic agent, having an appropriate drop size and velocity amongst other things, for efficient administration of same to an individual can be problematical. Alternative spacers in which the chamber is collapsible, the chamber having, for example, a concertina structure or nested interlocking rings, have also been developed. Though less bulky when collapsed, these spacers still present peripheral ridges and projections, including typically a mouth piece, which makes them difficult to store and transport in, for example, a handbag or pocket. Such spacers can, if desired, be stored in a separate carrying case. However, this further amplifies yet another problem with these types of chambers or spacers in that they are difficult to erect particularly by a patient who is young or elderly or who may be in an anxious state. Typically, in order to erect the spacer chamber, a patient will have to extract the apparatus from its carrying case prior to assembling it. This takes time and delays delivery of the medicament to the patient. Assembly of the spacer or chamber may then in itself be problematical and incur further delay in that it is usually necessary for a patient to grasp the apparatus with both hands and to open or erect the spacer or chamber by axially separating his hands. The ends of the spacer are typically sloping and smooth and therefore it is easy for the spacer to slip out of a patient's grasp and also it may be difficult for a patient to coordinate his hands and exert the necessary steady axial motion on the spacer so as to erect it. It is therefore an object of the invention to provide a respiratory apparatus incorporating a dispersion chamber or spacer which is easy to erect and collapse even by young or old patients or those in a distressed or anxious state. It is a further object of the invention that such apparatus is easy to store, to transport and, in particular, to carry around in, for example, a pocket or a handbag. It is a further object of the invention that such apparatus can be varied in length so as to provide a dispersion chamber or spacer of differing lengths and/or volume and/or shape. It is a further object of the invention to provide apparatus which enables efficient administration of respiratory agent or therapeutic substance. It is a further object of the invention that such apparatus is easy to clean. It is a further object of the invention that such apparatus can accommodate conventional hand-held pocket sized inhalers or drug delivery devices without leakage. It is a further object of the invention that such apparatus is relatively cheap and simple to manufacture. In one of its broadest aspect, the invention comprises respiratory apparatus for use in an inhaler system comprising a first member, a second member and a collapsible chamber positioned between said first and second members. According to the invention there is therefore provided a respiratory apparatus for use in an inhaler system comprising a first member including a mouth piece attachment; a second member including a means for introducing a substance into said apparatus; and, mounted therebetween, at least one collapsible chamber whereby said members can be gripped and moved with respect to one another so as to wholly or partially erect or collapse said chamber. It will be understood by those skilled in the art that when erect, said collapsible chamber comprises a dispersion chamber or spacer for dispersing, mixing and retarding said substance which typically includes at least one therapeutic substance. It will be further understood by those skilled in the art that said chamber can be simply and quickly erected in a single action when required and just as easily retracted and stored or carried around when not in use. In a preferred embodiment said first and second members are adapted to directly or indirectly engage theretogether so that said apparatus can be releasably held in a collapsed state when not in use. In a further preferred embodiment said members can be moved axially with respect to one another. In a further preferred embodiment, said apparatus is adapted to be releasably held in a wholly or partially erect state. Preferably said first member, said second members and/or said collapsible chamber comprise a snap fit mechanism or other means known to those skilled in the art to releasably hold said collapsible chamber in a partially or wholly erect state. Preferably a plurality of such mechanisms and/or other means are provided so that the collapsible chamber can be held in a number of such states as required. In a further preferred embodiment said collapsible chamber comprises at least two interengaging nestable members movable in relation to one another. Preferable said nestable members are adapted to move in telescopic fashion with respect to one another. Advantageously said nestable members are releasably lockable in a predetermined arrangement one with respect to another so as to provide a collapsible chamber of a desired length and/or volume and/or shape. Preferably a snap-fit mechanism is provided comprising at least one shaped recess on an innerside of one nestable member and a cooperating projection for releasably engaging said recess on or about the other nestable member, or visa versa. Preferably said cooperating projection is resiliently mounted to an edge region of a nestable member. Ideally a plurality of said recesses are provided spaced axially along an inner surface of a nestable member for engaging the other nestable member in a variety of predetermined positions where a chamber of predetermined length and/or volume and/or shape can be provided. In a further preferred embodiment at least one of and preferably both of said first and second members comprise a base. Preferably said base has at least one upstanding wall mounted thereto which wall comprises one of said at least two nestable members. Preferably the base of at least said first member comprises a dished portion. Advantageously said second member and said upstanding wall mounted to the first member or vice versa are provided with a cooperating snap fit mechanism or other means for indirectly engaging said first and second members theretogether when said chamber is in a collapsed state. In a preferred embodiment the upstanding wall mounted to the second member is nestable within the upstanding wall mounted to the first member. In a preferred embodiment when fully extended the chamber has a volume of between approximately 30 and 750ml. In a further preferred embodiment said chamber when wholly erect has a substantially, smoothly, varying cross sectional area. Preferably the area increases substantially linearly from said second member to said first member. Preferably the walls of the chamber are at an angle of approximately a few degrees with respect to the central longitudinal axis of the spacer. Ideally, the walls are at an angle of approximately 1-2° and ideally 1.5-1.7° with respect to this axis. Advantageously, the ratio of length to change in diameter of the collapsible chamber is 150-10. Preferably the ratio is approximately 35. It will be understood from the above that where a spacer according to the invention is provided having a predetermined size and/or geometry the amount of mixing of respiratory agent or therapeutic substance within the spacer and/or the speed of propulsion of agent or substance can be controlled in order to ensure adequate dispersion and diffusion of the agent prior to inhalation and therefore efficient adrninistration of the agent or substance. In a further preferred embodiment said means for introducing a substance is adapted to releasably connect the outlet or outflow port of, preferably, a conventional hand-held pocket sized inhaler or drug delivery device which in use is in fluid connection with said chamber. Preferably a valve is provided in said means so that fluid cannot flow out of said apparatus to said inhaler. Ideally the means comprises an aperture in the base of the second member. Advantageously the aperture is sized and shaped to frictionally and substantially sealingly engage the outflow port of a conventional hand held pocket inhaler or drug delivery device. Alternatively or in addition a seal, which is preferably resilient, is provided on or about the aperture for substantially sealingly engaging said outflow port. In a further preferred embodiment said apparatus further comprises a cradle adapted to cooperate with an aperture in the base of said second member. Preferably said cradle is sized and shaped to accommodate a conventional hand held drug delivery device or inhaler and to direct the outflow of said device or inhaler towards the collapsible chamber. Advantageously the cradle accommodates such a device or inhaler in a predetermined position and/or orientation with respect to said chamber and/or said mouthpiece attachment of said first member. Ideally the cradle is releasably lockable within the aperture when in use. Advantageously accommodates such a device or inhaler in a predetermined position and/or orientation with respect to said chamber and/or said mouthpiece attachment of said first member. Ideally the cradle is releasably lockable within the aperture when in use. Advantageously the cradle is sized and shaped to be inserted into the chamber via said aperture, which chamber thereby provides a containment unit for said cradle, when not in use. Preferably the cradle and/or the chamber are adapted so that the cradle is releasably held in a relatively fixed location with the chamber when inserted in the chamber. In a further preferred embodiment said collapsible chamber is releasably mounted between said first and second members. It will be understood by those skilled in the art that the provision of a chamber which is, ideally, releasably mounted and therefore separable from said members and which comprises washable material ensures that the respiratory apparatus and, in particular, the chamber is simple and easy to clean and/or replace. This is particularly important when dealing with therapeutic substances and their delivery since hygiene is of paramount importance. Furthermore, this allows the replacement of the collapsible chamber or said first and second members if any of these are broken or damaged. In a further preferred embodiment, said mouth piece attachment is adapted to be used as a mouth piece. Alternatively, or in addition, said mouth piece attachment is adapted to releasably attach a mouth piece in fluid connection to said chamber. Ideally, a valve is provided in said attachment so that fluid can only flow out of said chamber to said mouth piece when a patient inhales. Preferably, a range of differing mouth pieces can be so attached. In a preferred embodiment said chamber is substantially circular in cross-section at least in part. Alternatively said chamber is substantially polygonal, such as triangular, rectangular, square, hexagonal etc, in cross-section at least in part. In a preferred embodiment said first and second members are adapted to be gripped by the provision of gripping means, such as a knurled or ribbed surface, or a friction engaging surface or the like. In a further preferred embodiment, said first member is or comprises a first storage member and said second member is or comprises a second storage member, and further one or both of said first and second storage members are adapted to directly engage the other of said first and second storage members so said members can engage theretogether to provide a containment unit for said chamber. In a preferred embodiment, said chamber, when wholly or partially erect, has a greater cross-sectional area at a point part-way between said storage members than at end regions of said chamber. Preferably, said point is substantially halfway between said storage members when said chamber is fully erect. Alternatively, or in addition, said chamber has a substantially constant cross-sectional area along at least a part of its length. In a further preferred embodiment said collapsible chamber comprises a plurality of nestable rings movably connected theretogether. Ideally, said rings, which are preferably though not necessarily cylindrical, have progressively increasing average diameters from a first ring adjacent said first storage member to a further ring adjacent said point partway between said storage members, and progressively decreasing average diameters from said ring adjacent said point to a second ring adjacent said second storage member. Preferably, said rings adjacent said first and second storage members have substantially the same average diameter. In this way, said chamber comprises two relatively inverted frusto-conical portions. Preferably, at least one ring and ideally each ring is frusto-conical in shape. Alternatively, or in addition, each ring has a substantially constant diameter, though this need not necessarily be the same as that of neighbouring rings. Preferably, said rings are rigid and washable and, ideally, comprise plastic, plastic composite or the like. In a preferred embodiment as an alternative, or in addition, to the provision of nestable rings, said chamber comprises at least one flexible tube. Preferably said tube is washable and, ideally, comprises flexible material such as flexible plastic, plastic composite, PVC coated cloth or the like. In a further preferred embodiment, one of said storage members, preferably said first storage member, and said detachable mouthpiece are each provided with cooperating mating members for releasably mounting said mouthpiece on said storage member when not required. Preferably, said storage member is provided with at least one protrusion extending from its inner most surface, and an inner bore of said mouthpiece is sized and shaped so as to be releasably mounted on said protrusion. Ideally, said means for introducing a substance on said second storage member comprises a hole through which said mouthpiece can be inserted for mounting on said protrusion when said storage members are engaged theretogether, so as to facilitate storage of said mouthpiece when the apparatus is not in use. In a further preferred embodiment, at least one and preferably both of said storage members are provided with a cooperating releasible snap-fit mechanism for engaging said members theretogether. Alternative ways of releasably connecting said members theretogether will be understood by those skilled in the art and these alternatives are intended to be covered by this application. Ideally, said storage members are nested at least in part when engaged theretogether. Ideally said storage members, are washable and preferably comprise rigid plastic, plastic composite or the like. Ideally said storage members and said chamber are transparent. Preferably said storage members are circular and/or dished and ideally, smoothly contoured on at least their outermost surface so as to present no rough or sharp edges. Accordingly to a second aspect of the invention there is also provided a collapsible chamber as herein described for use in said apparatus. According to a third aspect of the invention there is also provided storage members as herein described for use in said apparatus. According to a fourth aspect of the invention there is provided a kit of parts comprising at least one pair of storage members and at least one collapsible chamber for mounting therein. Preferably said kit comprises at least one mouth piece; at least one said apparatus and at least one collapsible chamber. In a preferred embodiment said kit comprises first and second members, said collapsible chamber and a cradle according to the invention. According to a fifth aspect of the invention there is provided a method of dispersing a therapeutic substance comprising: ejecting a stream of therapeutic substance and, ideally, a propellent into a dispersion chamber at high velocity; expanding the cross-sectional area of said stream in order to mix and distribute said substance prior to delivery to a patient; and contracting the cross-sectional area of said stream and preferably simultaneously directing said contracted stream towards an outlet from said chamber ready for delivery to a patient. Preferred embodiments of the invention will now be described by way of example only with reference to and as illustrated in the accompanying drawings. Figure 1 represents a part sectional view of respiratory apparatus in accordance with the invention in a fully assembled and erect state. Figure 2 represents the same part sectional view of the respiratory apparatus seen in Figure 1. Figure 3 represents a part sectional view of respiratory apparatus in a wholly collapsed state. Figure 4 represents a part sectional view of alternative respiratory apparatus according to the invention. Figure 5 represents part sectional views of two alternative respiratory apparatus in accordance with the invention, seen on either side of line AA'. Figure 6 represents part sectional views of two further alternative respiratory apparatus in accordance with the invention seen on either side of line BB'. Figures 7a and 7b represent sectional side views of alternative respiratory apparatus in accordance with the invention in extended and collapsed state respectively. Figure 7c represents part of the apparatus seen in Figures 7a and 7b. Figure 8a and 8b represent sectional side views of alternative respiratory apparatus in accordance with the invention in extended and collapsed states respectively. Figure 8c represents part of the apparatus seen in Figures 8a and 8b. 11A Figures 9A and 9B represent side views of further alternative respiratory apparatus in accordance with the invention, in extended and collapsed states respectively. Figures 10A and 10B represent side views of further alternative respiratory apparatus in accordance with the invention, in extended and collapsed states respectively. 12 Referring firstly to Figure 1, respiratory apparatus 1 comprising a collapsible chamber 2, end covers 3 A and 3B and a mouthpiece 4 is shown. Referring now to Figure 2, the collapsible chamber 2 comprises nested interlocking rings 2A which have progressively increasing and decreasing average diameters from end cover 3A to end cover 3B. Rings 2A, which, in this particular embodiment, are cylindrical in cross section and frusto-conical in shape, form when extended two relatively inverted frusto-conical halves 5A and 5B which meet at mid point 5 halfway between end covers 3 A and 3B. Nested rings 2 A are movably connected theretogether by an interlocking mechanism (not shown) at regions 7 as would be well understood by those skilled in the art. Halves 5A and 5B are connected theretogether at their respective bases or rims by fastening means 6. End cover 3B is provided with an aperture or outlet 8 which typically comprises elastomeric material such as rubber for locating, in use, a conventional hand-held inhaler or puffer. End cover 3 A comprises a recess 11 for releasably mounting an annular rim or flange 4A of mouthpiece 4 therein. End covers 3A and 3B are also provided with cooperating engagement mechanisms such as frictionally fitting or snap fitting members. In this particular embodiment, storage members 3 A and 3B are provided with cooperating frictionally engaging annular recesses 13 A and 13B about their respective rims. Typically end covers 3A and 3B and chamber 2 further comprise cooperating releasable mountings for collapsible chamber 2 (not shown). In this way collapsible chamber 2 can be disconnected from end covers 3A and 3B to facilitate cleaning and/or replacement of chamber 2 or end covers 3A and 3B. Though this is not essential in the broadest sense of the invention, it will be understood by those skilled in the art that the provision of releasable mountings for chamber 2 will also allow the provision of a number of chambers of differing 13 sizes and shapes which may be required to fulfill the differing needs of one or a range of patients. In addition, end cover 3A is provided with a projection 9 having a valve 10 located therein. The distal end of projection 9 is adapted to frictionally engage, snap fit or otherwise cooperate with a remote end 4B of mouthpiece 4 when the apparatus is not in use. This is shown more clearly in Figure 3, in which apparatus 1 is shown in a wholly collapsed state ready for storage or transportation. As can be seen from this figure, mouthpiece 4 and in particular annular rim 4 A of mouthpiece 4 has been removed from recess 11. Furthermore end 4B of mouthpiece 4 has been positioned on the distal end of projection 9 so as to facilitate storage of mouthpiece 4. Projection 4 is mounted on the inner surface of end cover 3A by means of ribs 12. Figure 3 also clearly shows frusto-conical rings 2A neatly and compactly stacked theretogether so enabling end covers 3 A and 3B and in particularly recesses 13 A and 13B to engage theretogether so providing a storage unit for chamber 2. Typically end covers 3A and 3B are provided on their outermost surfaces with knurled, pitted or friction engaging surfaces or other gripping means so that a patient may securely and firmly grip end covers 3A and 3B. This facilitates assembly and collapse of the inhaler. In use, the patient has simply to insert mouthpiece 4 into recess 11 and to grasp end covers 3A and 3B and separate them axially with respect to each other in order to erect chamber 2 ready for delivery of a medicament. A conventional hand-held inhaler or puffer can then be inserted into inlet port 8 and used in the normal way to provide a mixture of therapeutic substance and propellent within chamber 2 prior to inhaling of the contents of the chamber via valve 10 and mouthpiece 4. 14 Typically port 8 and or mouthpiece 4 will comprise elastomeric material such as rubber or the like in order to facilitate, firstly, location of a conventional inhaler or puffer in port 8 and, secondly, location of mouthpiece 4 on projection 9. It will also be apparent to those skilled in the art that a range of chambers of differing volumes and/or lengths and a range of mouthpieces may be provided so as to accommodate the needs or requirements of different patients. Alternative embodiments can be envisaged by those skilled in the art and these are intended to be covered by this application. These include, for example, end covers 3A and 3B and chamber 2 which are not circular but polygonal, triangular or hexagonal, for example. Furthermore mouthpiece 4 may be supplemented or replaced by a permanent mouthpiece located adjacent or partially within recess 11. Furthermore, chamber 2 need not comprise nested rings and alternative forms of chamber 2 are shown in Figure 4 to 6. In the following figures like referenced numerals refer to afore like referenced features. Referring now to Figure 4, chamber 2 comprises a tube or bag of semi-flexible material constructed in a concertina fashion so as to facilitate extension or retraction of the chamber. Here, the bag is supplemented by relatively rigid ribs 14 and pre-defined creases 15 in the material of the bag. In order to erect or collapse chamber 2, end covers 3 A and 3B are gripped and moved axially with respect to one another so that concertinaed sections 2B are expanded or collapsed. Referring now Figure 5, two alternative arrangements for chamber 2 are shown. Firstly, to the left of line AA', interlocking nestable rings 2C each have substantially constant, though different, diameters across their axial length. However the size of adjacent rings varies so that a first ring adjacent a first end cover, for example, has a smaller diameter than a next adjacent ring. The ring adjacent point 5 midway between covers 3A and 3B has the greatest diameter. 15 To the right of line AA' similar interlocking nestable rings 2D each of constant axial diameters are shown. However, the diameter of adjacent rings varies here, the ring of greatest diameter is positioned closer to end cover 3A having mouthpiece 4 than to end cover 3B. Providing a chamber having a greater cross-sectional area partway between end covers 3A and 3B than adjacent covers 3A and 3B ensures that when one or more substances are ejected into the chamber from inlet port 8, these substances are expanded and distributed over a greater surface area so as to facilitate mixing and distributing of same. Subsequently, the substances are contracted and furthermore, directed towards an outlet for delivery to a mouthpiece so as to ensure that the now adequately mixed and distributed substances are delivered to the mouth of a patient. Referring now to Figure 6, two yet further alternative chambers 2E and 2F are illustrated. To the left of line BB' , chamber 2E comprises a substantially constant diameter cylindrical tube of flexible and ideally washable material such as plastic, PVC, etc. Ideally, this tube is provided with reinforcing ribs 14 made from relatively rigid material such as plastic, metal or the like. Here ribs 14 comprise concentric rings though it will be understood by those skilled in the art that ribs 14 may be replaced or supplemented by one or more spiral ribs located on tube 2E. To the left of line BB', tube or chamber 2F similarly comprises flexible material such as plastic, PVC or the like. Here tube 2F has a greater diameter at mid point 5 than at its end. Again, reinforcement by ribs 14 may be supplemented or replaced by one or more spiral ribs. Such an arrangement would facilitate storage of the inhaler since spiral ribs would collapse within themselves whereas, individual concentric ribs would tend to lie on top of one another. 16 Referring now to Figure 7a, alternative respiratory apparatus 1 is shown is an erect or extended state ready for use. Apparatus 1 comprises a collapsible chamber 2 formed from two interlocking telescoping portions 20a and 20b. Guide ridges 23 on the outer surface of portion 20a and the inner surface of portion 20b are provided for securing and guiding portion 20a within portion 20b during axial manipulation of the telescoping portion to extend or retract the apparatus. Telescoping portions 20a and 20b are mounted between end members 21a and 21b. End member 21a is a base comprising an aperture 22 formed therethrough which aperture is sized and shaped to accommodate a cradle 16. Cradle 16 is sized and shaped to accommodate a conventional hand held puffer or drug delivery device and to position same so that the outflow from such a device is directed into collapsible chamber 2. Cradle 16 is also provided with a shaped and typically resilient portion 17 for frictionally and/or resiliently holding cradle 16 in fixed position with respect to chamber 2 during use. In particular, portion 17 is provided with shaped and/or resiliently mounted projections at 18 for engaging the innermost edges of aperture 22. Cooperating projections or recesses can also be provided on or about aperture 22 on base or end member 21a. Telescoping portion 20a is provided on or about its upstanding edge region, one or more resilient projections 15a. This can be seen clearly in figure 7c. projections 15a engage one or more corresponding recesses 15b on the inner side of telescoping portion 20b when apparatus 1 is extended for use. In this way, projections 15a and recesses 15b comprise a snap-fit mechanism. Alternative means of securing apparatus 1 in an extended position can be envisaged by those skilled in the art and these are intended to be within the scope of this application. Further recesses 15b can be provided axially along the inner surface of telescoping portion 20b so as to provide a plurality of locations for engaging projections 15a thus providing means for varying the length and/or shape and/or 17 volume of apparatus as required. When not in use, cradle 16 is inserted into telescoping portion 20a and 20a is retracted into portion 20b disengaging projections 15a from recess or recesses 15b. When retracted, portion 20a is held within portion 20b by a cooperating snap-fit mechanism typically positioned on or adjacent base or end member 21a and the free edge region of portion 20b or vice versa (not shown) as would be well understood by those skilled in the art. Apparatus 1 is shown in a collapsed state ready for transport or storage in Figure 7b. Apparatus 1 is extended by moving members 21a and 21b axially apart until projections 15a engage recesses 15b. Where a plurality of recesses 15b are provided, apparatus 1 can be varied to a predetermined length or volume etc as required. Cradle 16 is extracted from portion 20a and positioned within aperture 22. A puffer is introduced into cradle 16 for administration of therapeutic substance or agent to an individual via respiratory apparatus 1 and mouthpiece 4. In order to ensure efficient administration of a therapeutic substance or agent, respiratory apparatus 1 having a predetermined size and geometry is provided. Typically apparatus 1 has a length to change in diameter ratio of 35. Thus, cradle 16 securely locates a conventional puffer adjacent base and/or member 21a at a predetermined distance typically ?cm from mouthpiece 4. Also, telescoping portions 20a and 20b have a predetermined size and geometry in that they comprise two frusto conical portions having sides angled at a few degrees with respect to a longitudinal axis of the apparatus. Typically the angle is 1.5°. Also, the collapsible chamber can be varied in length and volume etc as described in the preceding paragraphs thus the degree of mixing and the speed of propulsion of therapeutic substance or agent on reaching an individual can be controlled to ensure adequate diffusion and dispersal of the therapeutic agent or substance providing typically an appropriate drop size, thus ensuring efficient administration 18 of the therapeutic agent or substance. Typically, the chamber when wholly extended has a volume of between approximately 30 and 750ml. Referring now to Figures 8A, 8B and 8C, an alternative respiratory apparatus 1 is shown. Here, an end member or base 21C which projects beyond the periphery of telescoping portion 20A is shown. Typically, base or end member 21C comprises an aperture (not shown) for insertion of a conventional hand-held puffer or drug delivery device therethrough. Alternatively, end member 21C is releasably fitted onto base 21A (not shown). In this case, 21C is removed prior to insertion of a conventional hand-held puffer into apparatus 1 via base 21A. Base 21A or 21C and end member 21B may be provided with ridges, projections or other friction increasing means such as a rubber coating for facilitating gripping of same and thus manipulation of apparatus 1 particularly during extension and retraction. Referring now to Figures 9A and 9B, an alternative respiratory apparatus 1 is shown. This embodiment is functionally similar to that shown in Figures 7A, 7B and 7C but is additionally supplied with an area 30 of raised ridges or ribs which aid the gripping of apparatus 1 when in use. This gripping means could, alternatively, take the form of a knurled or other friction-engaging surface. As an alternative to the above-described snap-fit mechanism (projections 15A and recesses 15B), the embodiments of Figures 9A and 9B is provided with a locking tab 31 at the chamber-distant end of cradle 16. Correspondingly shaped recesses 32 and 33 are provided on telescoping portions 20A and 20B respectively. When apparatus 1 is in its collapsed form (Figure 9B) recesses 32 and 33 are substantially aligned with one another and locking tab 31 snap-fits into said recesses so as to releasably lock apparatus 1 in its collapsed position. As an alternative to projection 9 having a valve 10 located therein (see 19 Figures 2 and 7A), this arrangement may be replaced by a baffle plate (not shown). It will be apparent to those skilled in the art that respiratory apparatus according to the invention presents a number of advantages over the known art. In particular, the apparatus is easy and simple to erect and collapse and furthermore is particularly compact for storage. In addition the apparatus according to the invention, by having a pre-selected size and geometry provides for controllable and predetermined dispersion and distribution of therapeutic agent within it and therefore efficient administration of same to an individual. Furthermore, the apparatus is adapted for a range of patients having differing requirements. It is also adaptable to be easily cleaned or replaced in part and to accommodate a range of conventional inhalers or puffers without leakage. This is achieved in an elegantly simple design which is relatively easy to make and cheap to manufacture.

Claims: 20 CLAIMS 1. Respiratory apparatus for use in an inhaler system comprising a first member including a mouthpiece attachment; a second member including a means for introducing a substance into said apparatus; and, mounted therebetween, at least one collapsible chamber whereby said members can be gripped and moved with respect to one another so as to wholly or partly erect or collapse said chamber. 2. Respiratory apparatus as claimed in Claim 1 characterised in that said first and second members are adapted to directly or indirectly engage theretogether so that said apparatus can be releasably held in a collapsed state when not in use. 3. Respiratory apparatus as claimed in Claim 1 or Claim 2 characterised in that said members can be moved axially with respect to one another. 4. Respiratory apparatus as claimed in any of the preceding claims characterised in that said collapsible chamber comprises at least two interengaging nestable members movable in relation to one another. 5. Respiratory apparatus as claimed in Claim 4 characterised in that said nestable members are adapted to move in a telescopic fashion with respect to one another. 6. Respiratory apparatus as claimed in Claim 4 or Claim 5 characterised in that said nestable members are releasably lockable in a predetermined arrangement one with respect to another so as to provide a collapsible chamber of a desired length and/or volume and/or shape. 21 7. Respiratory apparatus as claimed in any of the preceding claims characterised in that said chamber when wholly erect has a substantially, smoothly, varying cross-sectional area. 8. Respiratory apparatus as claimed in any of the preceding claims characterised in that said apparatus further comprises a cradle adapted to cooperate with an aperture in the base of one of said nestable members. 9. Respiratory apparatus as claimed in Claim 8 characterised in that said cradle is sized and shaped to accommodate a conventional hand-held drug delivery device or inhaler and to direct the outflow of said device or inhaler towards the collapsible chamber. 10. Respiratory apparatus as claimed in Claim 8 or Claim 9 characterised in that said cradle is sized and shaped to be inserted into the chamber via said aperture, which chamber thereby provides a containment unit for said cradle, when not in use. 11. Respiratory apparatus as claimed in any of the preceding claims characterised in that said first and second members are adapted to be gripped by the provision of gripping means, such as a knurled or ribbed surface, or a friction engaging surface or the like 12 Respiratory apparatus as claimed in any of the preceding claims characterised in that said first member is or comprises a first storage member and said second member is or comprises a second storage member, and further one or both of said first and second storage members are adapted to directly engage the other of said first and second storage members so said members can engage theretogether to provide a containment unit for said chamber. 13. Respiratory apparatus substantially as described herein with reference 22 to and as illustrated by any appropriate combination of the accompanying drawings.

Inventors: FORD THOMAS MCDONALD, FORD, THOMAS, MCDONALD
Applicants: FORD THOMAS MCDONALD, SOVEREIGN SURGICAL LTD, FORD, THOMAS, MCDONALD, SOVEREIGN SURGICAL LIMITED
Application year: 1996
Main classification: A61M15
IPC codes: A61M15