Ostomy pouches

Abstract: An ostomy pouch (10) includes a front wall (12) provided with a comfort layer (16) and a vent (22). An apertured cover layer (24) is secured to the front wall (12) through the comfort layer (16) to define a chamber for a filter element (28) and to provide a smooth surface to which can be applied an adhesive sticker. The cover layer (24) includes a plurality of apertures (30), and the flow rate through the vent can be controlled by positioning the sticker to selectively block one or more of the apertures (30). An adhesive wafer (40) includes both circular and non-circular (race-track) cutout guidelines for enabling the aperture to be cut to any desired shape and size. The wafer (40) is secured to the pouch along a weld line having a shape corresponding to a combined circular and race-track silhouette.

Description: The present invention relates to ostomy pouches for the collection of waste, or discharge, from a temporary or permanent ostomy opening. The invention is applicable equally to so-called one piece designs in which the pouch is integral with an attachment pad or wafer for attaching the pouch to the body of the ostomate, and with so-called two-piece designs in which the pad or wafer for securing the pouch to the ostomate is separate from, and is releasably attachable to, the pouch. The invention relates to a filtered flatus vent which is commonly provided in certain ostomy pouches. The vent allows flatus gas within the pouch to escape, in order to avoid ballooning of the pouch. A sticker is provided which is initially adhered over the exit from the vent in order to prevent, initially, any gas from flowing through the vent. The purpose of this is, when the pouch is first worn, to allow some gas to build up within the pouch and thereby prevent the sides of the pouch from sticking to each other, which could cause undesirable pancaking. Once the pouch has begun to inflate (and the sides separated from each other), the sticker can be removed in order to allow flatus to vent in the normal way. Reference may be made to US-A-4938750 which describes a pouch with selective multiple deodorising filters. A member in the form of a moulded housing affixed to the pouch wall has a plurality of isolated vent recesses, each communicating with plural vent apertures. A separate filter element is situated in each recess. Adhesive coated covers are situated to obstruct the flow through all but a selected one of the filter elements. After a filter in the unobstructed recess has lost its effectiveness, the cover is removed from another recess and placed over the recess containing the used filter to deselect the same. Each filter is exposed in turn by appropriate movement of the cover until all of the filters have been used. Reference may also be made to EP-A-0535801, EP-A-0868892, DE-A-19519069, GB-A-2273052 and US-A-5690622. Embodiments of the present invention are defined in the claims. In one form, the present invention provides an apparatus comprising a filtered vent assembly for an ostomy pouch, the filter vent assembly comprising a filter element, and a variable flow rate outlet device communicating with the filter element, the variable flow rate outlet device comprising means defining a plurality of outlet apertures communicating with the filter element, and adhesive sticker means positionable or configurable to selectively expose or cover one or more of the plurality of apertures, the arrangement being such that, in use, the flow rate through the filter element is controlled by the number of apertures which are exposed or covered. The sticker means comprises a sticker element dimensioned so that it is of sufficient size to be able to cover all the outlet apertures of the vent assembly (when positioned appropriately), and is movable in one piece. This aspect can provide a very simple, yet convenient way of allowing the user to control the flow rate of flatus passing through the vent. This is in contrast to the prior art in which the sticker and the single exit can provide only on/off control. When the sticker is removed, if the flow rate of gas through the filter is too high (depending on a particular person's metabolism and on the food consumed), the sides of the pouch may tend to stick to each other again, and cause pancaking. However, with this aspect of the present invention, the ostomate can selectively cover, or uncover, a desired number of the outlet apertures to control the rate at which flatus vents, and thereby control the degree of pouch inflation to prevent pancaking. The exits may be in the form of slits, or other apertures, formed in a plastics film covering, for example, the filter. Alternatively, the exits may be in the form of clearances between one or more welds, or weld segments. If desired, a flow constricting layer may be provided upstream of the outlets (for example, under a plastics layer having outlet apertures). This can allow the apertures to be made larger, and more easily identifiable, without such critical dependency on aperture size. The presence of the flow constricting layer can enable larger apertures to be used because the flow is constricted by the layer. The flow constricting layer may, for example, consist of micro-porous material. Preferably, the ostomy pouch comprises a co-called comfort layer. Such a comfort layer is generally soft and permeable, and is provided outside the non-permeable plastics wall of the pouch to provide more comfortable wearing characteristics. Customers generally prefer a comfort layer to be provided on both the rear face (i.e. adjacent to the skin) and on the front face (i.e. facing the wearer's clothing). Preferably, the outlet of the vent is defined by at least one segment of smooth, substantially impermeable, plastics material positioned outside the comfort layer. This can provide a surface with excellent characteristics to allow the adhesive sticker means to adhere to provide a gas-tight (or at least substantially gas-tight) seal, and thereby enable the sticker to control the flow of gas through the vent. To the best of the inventor's knowledge, it is unknown hitherto to employ a sticker for a vent through a wall carrying a comfort layer. In particular, it might be difficult to achieve a gas-type seal if the sticker is applied directly to the comfort layer. In the preferred embodiment, the provision of the smooth plastics material outside the comfort layer can overcome this problem. As explained previously, there is a need for some form of device, at least initially, to block or constrict the flow of flatus through the vent, in order to prevent pancaking. The ability to provide a simple adhesive sticker means with a comfort-layer adorned pouch is an extremely significant advantage. Preferably, the comfort layer is provided outside the majority of at least the upper portion of the pouch. Preferably, the smooth material described above overlies a portion of the comfort layer, and is secured to the underlying wall of the pouch through the comfort layer (for example, by welding, or by adhesive). Preferably, the smooth material outside the comfort layer forms an outer cover for the filter, and is secured to the underlying pouch wall around the filter. The line of attachment (e.g. welding) may be continuous, or it may be discontinuous to provide one or more vent exits. In one preferred embodiment, the pouch includes a first wall of substantially liquid and gas impermeable plastics material, an aperture being provided in the first wall to allow the venting of flatus, the comfort layer being provided outside the first wall, and the filter cover layer being outside the comfort layer and secured to the first wall through the comfort layer, the cover layer and the portion of the first wall underlying the cover layer defining a housing in which is received the filter element for processing the flatus vented through the aperture. The filter element may, for example, include material for deodorising the flatus, and/or material for absorbing any liquid which accidentally escapes through the aperture in the first wall. The filter element may be positioned between the first wall and the comfort layer. In that case, the filter is preferably attached to the first wall, to provide a seal around the aperture in the first wall. Alternatively, the filter element may be provided between the comfort layer and the cover layer. In either case, the filter may either be attached to the cover layer, or it may be attached to the first wall. Preferably, the pouch further comprises an adhesive wafer for adhesively attaching the pouch to the wearer's skin. More preferably, the wafer (or a cover layer provided on the wafer) is provided with guidelines for enabling a person to cut the wafer to a desired aperture size, the guidelines including at least one generally circular guideline, and at least one generally non-circular guideline. Preferably, the non-circular guideline is a so-called race-track guideline, defining a shape having generally straight sides, and rounded ends. Preferably, a plurality of circular, and a plurality of non-circular, guidelines are provided. This preferred feature can facilitate the same pouch being usable for a conventional ostomy application (where the aperture is normally circular) and also for other applications, including temporary ostomy (for example, loop ostomy) applications. For a temporary ostomy application, a more elongate aperture is desired to accommodate a temporary fold in the ostomate's intestines. To the best of the inventor's knowledge, hitherto pouches have only been available exclusively with circular guidelines, or exclusively with race-track guidelines. This has meant that a specific pouch has to be obtained to suit the desired application. However, with the present invention, a single pouch can be provided which a user can adapt very easily to the correct circular, or non-circular aperture size. It is preferred that the wafer is secured to the pouch by means of a weld or glue line having a non-circular and non-race-track shape. Preferably, the shape is defined by a combination of a circular shape and a race-track shape, the shape corresponding to a silhouette of one superimposed on the other. The use of such a weld (or glue) line might be the most efficient shape for accommodating a large circular, or race-track cut out, without requiring the adhesive wafer to be unnecessarily large. Preferably, the wafer also has a "hybrid" outer shape based generally on the silhouette of a circular shape and a race-track shape superimposed one on the other. It will be appreciated that the guidelines might be provided (by printing) directly on the adhesive wafer, or they may be provided on a release sheet which protects the adhesive surface of the wafer before use. The release sheet is intended to be peeled away before the adhesive wafer is pressed against the skin. Embodiments of the invention are now described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a section through a first embodiment of an ostomy pouch; Fig. 2 is a schematic exploded view showing the construction of the filter and filter housing; Figs. 3a-3e are schematic plan views showing adjustment of the sticker for flow control; Fig. 4 is a rear view of the pouch of Fig. 1; Figs 5a and 5b illustrate different cut outs of aperture in the wafer shown in Fig. 4; Fig. 6 illustrates a modified pouch and wafer with a mechanical coupling; Figs. 7a and 7b are schematic views showing a modified design of filter cover; Figs 8a and 8b illustrate an alternative construction of filter; Figs 9a and 9b illustrate a yet further construction of filter; Figs 10a-10d illustrate schematically positioning of the sticker for controlling the flow through the filter of Figs 9a and 9b; Figs 11a and 11b illustrate a further modified design of filter; Figs 12a-12e illustrate schematically peeling of the sticker for controlling the flow through the filter of Figs 11a and 11b. Referring to Figs. 1-5, and ostomy pouch 10 includes an envelope formed by a frontwall 12 and a rear wall 14 both of plastics material which is substantially impervious to liquid and to gas. Such plastics materials are well known in the art, and typically may consist of a laminate of one or more layers of ethylene vinyl acetate (EVA) on either side of a barrier layer of polyvinylidine chloride (PVDC). Other materials may be used as desired. A front comfort layer 16 is positioned outside the front wall 12, and a rear comfort layer 18 is positioned outside the rear wall 14. The comfort layers are generally soft and are permeable to gas and to liquid. Typically the comfort layers are made of Nylon, or polyethylene, or a mixture of polyester, viscous and rayon. The front and rear walls 12 and 14 and the comfort layers 16 and 18 are secured to each other by welding around a peripheral seam 20. The welding may be performed by an RF welding head, for example. Alternatively the seam may be formed by impulse welding, or by a heat seal and cut process. A filter housing 22 is located towards an upper portion of the front wall 12. The housing is formed by a filter cover 24 which is secured through the front comfort layer 16 to the front wall 12 in a generally gas-tight manner. In the present embodiment, the filter cover 24 is attached by welding, and the heat generated by welding is sufficient to at least partly melt the comfort layer in order to perform a reliable seal between the filter cover 24 and the front wall 12. The filter cover may, for example, be made of the same material as the front and rear walls 12 and 14. An aperture 26 is formed in the front wall 12 under the filter cover 24, and a filter element 28 is secured to the front wall 12 over the aperture 26. In this embodiment, the filter is a deodorising filter for deodorising flatus gas, and includes a deodorising agent, such as carbon. The filter may consist of foam carrying the carbon, or it may consist of other material, such as charcoal cloth. If desired, the filter may also include additional agents, such as a super absorbent agent for absorbing any liquid which leaks accidentally through the aperture 26. A suitable deodorising filter is manufactured by Freudenberg Limited, for example under the reference "option 20". Although the filter is illustrated to lie between the front wall 12 and front comfort layer 16, it will be appreciated that in other embodiments, the filter could be positioned between the filter cover 24 and the comfort layer 16, or on the other side of the front wall 12 (i.e. inside the envelope). The filter would need to be sealed to at least one of the front wall 12 and the filter cover 24, in order to prevent flatus leaking around the outside of the filter element 28. A plurality of gas exits 30 are formed in the filter cover 24. In the preferred embodiment, the exits 30 are relatively small (pin-hole) apertures in the filter cover 24. The number of apertures may be varied as desired; in the present embodiment, four apertures are illustrated. One or more of the apertures 30 may be selectively blocked by means of an adhesive sticker 32. As best seen in Fig. 3 the sticker consists of a main circular portion 34, and a finger tab 36 to enable the sticker to be grasped and peeled from the surface of the filter cover 24. The combination of the plurality of apertures 30 and the sticker 32 enables the user to control the rate of the flow of gas through the vent and the filter. As best seen in Fig. 3a, the size of the main circular portion 34 is sufficient to enable the sticker, when positioned appropriately, to block all four of the apertures 30. This completely cuts off flow through the filter vent. As illustrated in Figs. 3b-3e, by positioning the sticker 30 appropriately, 1, 2, 3 or all 4 of the apertures 30 may be exposed to allow a progressive increase in the flow rate through the filter vent. Such use of the sticker can provide the user with an extremely powerful, yet easy to use, flow control. Moreover, it will be appreciated that the use of material (in this case the filter cover 24) outside the front comfort layer 16 enables a sticker to be applied to achieve a substantially gas tight sticker seal. The sticker might be virtually ineffective if it were applied directly to the porous comfort layer. Referring to Figs. 1 and 4, the rear wall 14 and the rear comfort layer 18 include a stoma aperture 38 for receiving the ostomate's stoma, and for allowing the stomal discharge into the envelope. Attached to the rear wall 14, and encircling the stomal aperture 38 is an adhesive wafer 40 for allowing the pouch to be secured to the ostomate's skin. The wafer 40 consists generally of a layer of skin-compatible adhesive 42, a backing layer 44 of plastics material welded to the rear wall 14, and a silicone release sheet 46 having a finger tab 48 by which the release shut 46 can be peeled away from the adhesive 42 to expose the adhesive face. As best seen in Fig. 4, the release sheet 46 is printed with guidelines 50, (50a and 50b) for enabling the user to cut the wafer to a desired aperture size prior to fitting. This may either be carried out by the ostomate, or by a supervising nurse or other medical practitioner. In this embodiment, the guidelines include circular guidelines 50a and non-circular (race track) guidelines 50b. The circular guidelines 50a define a range of circular shaped apertures of different sizes, to suite permanent stomas, which generally have a circular or near-circular configuration. The race track guidelines 50b define a number of elongate apertures of different sizes, suitable for temporary stomas (e.g. stomas formed in a loop-ostomy operation, in which a portion of the intestine is extracted and is folded around a suitable rod, and is "sliced" open to define an elongate temporary stoma). As mentioned above, the backing layer 44 is welded to the rear wall 14. The weld line is illustrated in Fig. 4 by the shaded region 52. The weld line 52 defines a shape which is a silhouette of a circular shape superimposed on a race track shape. On this embodiment, the weld line 52 corresponds to the silhouette surrounding the largest permissible circular cut out, and the largest permissible race track cut out. The use of such a special shape of weld line 52 can provide a more versatile pouch design, enabling large circular cut outs (e.g. see Fig. 5a), and large race track cut outs (e.g. see Fig. 5b), to be accommodated without unnecessarily increasing the size of the wafer, or the size of the weld line between the wafer 40 and the pouch 10. As illustrated in Fig. 4, the overall shape of the wafer 40 is similar to the shape of the weld line 52, and corresponds to the silhouette of a circular shape superimposed on a racetrack shape. Although the above embodiment is a one-piece pouch, it will be appreciated that the same principles could be applied to a two-piece pouch (Fig. 6) in which the adhesive wafer 40 is not permanently fixed to the remainder of the pouch, but is a separate element 58 which is releasably attachable to the pouch, for example, by a mechanical coupling, or an adhesive coupling. Such couplings are well known in the art, and need not be described further here. Figs. 7a and 7b illustrate, in one form, the relationship between the size of apertures in the filter cover 24, and the need for the apertures to provide a constriction to the flow rate. It will be appreciated that, in order to achieve an adjustable flow, each individual aperture must provide a constriction to the flow of flatus gas. This can be achieved by making the apertures 30 suitably small, for example, in the form of slits (Fig. 7a). Alternatively, a flow constricting layer 60 may be provided under the filter cover 24 to constrict the flow through each aperture 30. This would allow the use of much large apertures 30, making them easier to identify than if narrow slits were to be used. A suitable constriction layer is of microporous material. Figs. 8a and 8b illustrate a modified construction of filter without the presence of a comfort layer. In this embodiment, the filter element 28 is located inside the envelope, on the inside face of the front wall 12. The aperture 26 in the front wall 12 is typically about 8-10 mm in diameter. To allow the use to control the flow with a sticker, the filter cover 24 (now referred to simply as a outer cover 24) is attached to the outer face of the front wall 12, and is provided with small pin-holes 30. The size of each pin-hole 30 is sufficiently small to constrict the flow of flatus through the apertures when one or more of the apertures is covered by the sticker 32. If desired, a constriction layer (not shown) similar to the constriction layer 60, may be provided under the cover layer 24 if larger, more easily identifiable, apertures 30 are required. In this embodiment, since the filter element 28 is located inside the envelope, it is preferred that a semi-porous protective membrane, or curtain, 62 be provided over the inner face of the filter, to prevent faecal matter in the pouch from directly contacting the filter element 28. Figs. 9a and 9b illustrate a further modified embodiment in which the filter element 28 is located outside the front wall 12 of the pouch. The cover layer 24 has three relatively large apertures 30 which are arranged in a generally straight line. A constriction layer 62 (micro-porous membrane) is located under the cover layer 24, in order to provide the required flow constriction for the size of aperture. Since the apertures 30 are arranged in a line, the constriction layer 62 is provided in the form of a narrow strip, in order to reduce wastage of material. Figs. 10a-10b illustrate the various positions of the sticker 32 over the apertures 30, to vary the flow from zero (Fig. 10a) to full flow (Fig. 10d). Figs. 11a and 11b illustrate a yet further modified construction of filter housing. In contrast to the earlier embodiments in which the cover layer 24 is sealed completely around the filter element 28 and has apertures 30 through the cover layer 24, the present embodiment employs a completely impervious cover layer 64, and the vent exits are defined by gaps 66 between weld segments 68 securing the cover 24 to the front wall 12 of the pouch. In the present embodiment, the cover 24 is illustrated to have a rounded end 70 to match the contour around the filter and a square end 72 at which the gas exits 66 are defined. Figs. 12a-12e illustrate how the flow rate through the exits 66 can be controlled by means of a sticker 74. Although a single sticker could be used as in the previous embodiments, here a multiple-segment sticker 74 consisting of segments 76 is employed. The flow rate is controlled by peeling away individual segments 76 from the exits 66. The segments may be separate from each other, or they may be attached to each other by breakable perforations 78 to allow the segments to be torn away. Although the embodiments illustrated in Figs. 8-12 do not include a comfort layer, it will be appreciated that the embodiments may be modified to include a comfort layer using the same principles as described in the first embodiment. It will be appreciated that many modifications of detail may be made without departing from the scope of the invention.

Claims: Apparatus comprising a filtered vent assembly (22) for an ostomy pouch, the filtered vent assembly comprising a filter element (28), and a variable flow rate outlet device communicating with the filter element for controlling variably the flow rate through the filter element, the variable flow rate outlet device comprising means (24;68) defining a plurality of outlet apertures (30;66) communicating with the filter element (28), and adhesive sticker means (32; 76) positionable or configurable to selectively expose or cover one or more of the plurality of apertures, the arrangement being such that, in use, the flow rate through the filter element (28) is controlled by the number of said apertures which are exposed or covered, wherein the sticker means comprises a sticker element (32) dimensioned so that it is of sufficient size to be able to cover all of the apertures of the vent assembly, and is movable in one piece. Apparatus according to claim 1,wherein said apertures communicate with a common outlet chamber downstream of said filter element. Apparatus according to claim 1 or 2, wherein one or more of the apertures (30) comprises a hole in a layer(24) to which the sticker means is adherable. Apparatus according to claim 1, 2 or 3, wherein one or more of the apertures comprises a clearance (66) between one or more welds, or weld segments (68). Apparatus according to any preceding claim wherein the sticker means comprises a plurality of stickers or sticker segments (76). Apparatus according to any preceding claim, further comprising a flow restricting layer (60;62) provided under the means (24) defining the apertures (30). Apparatus according to claim 6, wherein the flow restricting layer (60;62) comprises microporous material. An ostomy pouch (10) comprising a first wall (12), a comfort layer (16) for the first wall, wherein the first wall is provided with apparatus (22) as defined in any preceding claim. A pouch according to claim 8, wherein the means (24) defining the outlet apertures comprises at least one segment (24) of smooth substantially impermeable plastics material positioned outside the comfort layer (16), and to which the adhesive sticker means (32) can adhere. A pouch according to claim 9, wherein the smooth material (24) overlies a portion of the comfort layer (16) and is secured to the underlying first wall (12) of the pouch through the comfort layer (16). A pouch according to claim 9 or 10, wherein the smooth plastics material (24) forms an outer cover over the filterelement, and is secured to the pouch wall around the filterelement (28). A pouch according to claim 11, wherein the line of attachment is continuous. A pouch according to clam 11, wherein the line of attachment is discontinuous to provide a plurality of outlet apertures through which filtered gas may vent. A pouch according to any of claims 8 to 13, wherein the comfort layer (16) is provided outside the majority of at least an upper portion of the pouch. An ostomy pouch according to any of claims 8 to 14, further comprising an adhesive wafer (40) for securing the pouch to a person's skin, wherein the wafer, or a cover layer (46) provided on the wafer, is provided with guidelines (50a,50b) for enabling a person to cut the wafer to a desired aperture size, the guidelines including at least one generally circular guideline (50a) and at least one generally non-circular guideline (50b). A pouch according to claim 15, wherein the non-circular guideline or guidelines(50b) has or have a race-track shape. A pouch according to claim 15 or 16, wherein a plurality of the circular guidelines (50a) and plurality of the non-circular guidelines (50b) are provided. A ostomy pouch according to claim 15, 16 or 17, wherein the adhesive wafer (40) is secured to the pouch envelope around a closed loop line of attachment (52), the line of attachment having a shape which is non-circular and non-race-track. A pouch according to claim 18, wherein the line of attachment (52) is defined by a combination of a circular shape and a race-track shape, the combined shape corresponding to a silhouette of one superimposed on the other. Use of adhesive sticker means (32;76) to control variably the vent flow rate through a filtered vent for an ostomy pouch, the vent having a plurality of outlets (30; 66) and the sticker means being positionable to selectively expose or cover one or more of the plurality of outlets, to thereby regulate the gas flow rate according to the outlets exposed, wherein the sticker means comprises a sticker element (32) dimensioned so that it is of sufficient size to be able to cover all of the apertures of the vent assembly, and is movable in one piece. Use according to claim 20, wherein the flow rate is determined by the number of outlets exposed. Use according to claim 21, wherein the sticker means is positionable to cover at least one of said outlets communicating with said gas flow path while leaving uncovered at least one other outlet communicating with said same gas flow path. A method of controlling variably the flow rate through a filtered vent of an ostomy pouch, the method comprising positioning sticker means (32;76) to selectively block at least one of a plurality of outlets (32;66) of the vent while exposing at least one other of said oulets, to regulate the gas flow rate according to said outlets exposed, wherein the sticker means comprises a sticker element (32) dimensioned so that it is of sufficient size to be able to cover all of the apertures of the vent assembly, and is movable in one piece. A method according to claim 23, wherein the flow rate is determined by the number of said outlets exposed.

Inventors: FALCONER MALCOLM IAN, FALCONER, MALCOLM IAN
Applicants: SQUIBB BRISTOL MYERS CO, BRISTOL-MYERS SQUIBB COMPANY
Application year: 1999
Main classification: A61F5
IPC codes: A61F5