The invention relates to a ring-shaped filter case for incorporating into a coupling of an ostomy appliance. The invention also relates to an ostomy appliance with a collecting bag attached to the wafer with a mechanical coupling and where a ring-shaped filter case is included in the coupling.

Background

In connection with surgery for a number of diseases in the gastro-intestinal tract, one of the consequences in many cases is that the patient is left with an abdominal stoma such as a colostomy, an ileostomy or a urostomy in the abdominal wall for the discharge of visceral contents. The discharge of visceral contents including intestinal gasses cannot be regulated at will. For that purpose, the user will have to rely on an appliance to collect the material emerging from such opening in a bag, which is later emptied and/or discarded at a suitable time.

The discharge of flatus, measured in volume, may exceed the discharge of solid and liquid faecal matter by many hundreds of percent and therefore there is usually a need for continuous or frequent venting of the intestine or the collecting bag. Normally the outflowing flatus is deodorised with a suitable filter. Commonly, the active filter is powdered active carbon, which absorbs H ₂ S being the principal component of the smell of flatus.

During use of a collecting bag, the output from a colostomy or an ileostomy may stick to the face of the filter facing inwards in the collecting bag. This will eventually lead to clogging of the filter thereby reducing the flow through the filter. When the filter is completely blocked, it will stop functioning, and the bag will fill with gasses and expand, an effect also known as ballooning.

Description of related art

DK141392 describes a one-piece ostomy bag including a ring-shaped filter element placed between two ring-shaped gas-impermeable polymer sheets. One of these polymer sheets adhere to the skin and the other is fastened to the ostomy bag. In use, flatus or intestinal gasses can pass through the filter element from the inner periphery to the outer periphery. Summary of the Invention

The invention relates to a filter case for use in a coupling for an ostomy appliance. Placing the filter in the coupling has the advantage that it eliminates the need for a filter being placed anywhere else on the bag, at a position where it may be inconvenient. The filter case is provided with a plurality of inlet holes and a large outlet area - thus, it is possible to ventilate large amounts of flatus gasses through the filter. This is an advantage, particularly during the night, where a longer wear-time of the bag is expected. A longer wear-time may necessitate a larger collecting volume and thereby handling of a larger amount of flatus gas. The invention also relates to a two-piece ostomy appliance including a coupling with a filter case. The coupling may comprise a different sized bag-coupling part and wafer- coupling part. This reduces the height of the coupling in a direction outwards from the body of the user. Furthermore, for a two-piece bag, the filter need not be replaced with the bag, but can be re-used until the adhesive wafer with the coupling is replaced.

Detailed Description of the Invention

In a first aspect, the invention relates to a filter case for a coupling for an ostomy appliance comprising

a first part having a first extent between a first inner edge and a first outer edge, a second part attached to the first part and having a second extent between a second inner edge and a second outer edge,

o where the second part is placed a distance d in a direction transverse to the first extent from the first part so that the inner edges are substantially aligned with respect to each other,

o wherein a filter holding space is defined by the distance d and the extents of the first and second parts,

filter outlet(s) defined at the first and/or second outer edges,

a plurality of inlet holes placed in the second part for leading gas from an ostomy bag to the filter holding space.

A filter case according to the invention provides a space in connection with a coupling for a filter element. Furthermore, the filter case provides a plurality of inlet holes so that if one of them should clog then at least one other will still be open. In an embodiment of the invention, the inlet holes are defined in the interspace between the first and second outer edges. This is an easy way of providing the inlet holes because no additional holes need to be provided at the edges.

The filter case may be made of the same kind of material as the coupling for an ostomy bag. The materials should not be too brittle and should be able to be welded. As an example, Polyethylene can be used.

The filter case may include a filter element inserted in the filter holding space. The filter case in itself will be able to prevent faeces from coming into contact with the filter element contained in the filter holding space - thereby the filter element will not so easily be clogged. It will have a longer life span before it needs changing.

In an embodiment, the filter is a regular deodorising filter element - that is, an open cell foam element impregnated with carbon. These types of filters are well-known in the art, for example in European Patent no. 098131 1 B1.

In the following, whenever referring to the inner and outer, inner means closest to the stoma and outer means farthest away from the stoma in the plane of the abdominal surface of the user. The transverse direction means the direction from inner to outer or opposite - that is, a direction parallel to the plane of the abdominal surface of the user. The axial direction is the direction perpendicular to the transverse direction. The axial direction defines the top as the point or plane farthest away from the abdominal surface and the bottom as the point or plane closest to the abdominal surface.

Using these definitions, the inner edges of the first and second part are the edges that will be closest to the stoma, in the plane of the abdominal surface, when the filter case is fitted in a coupling in an ostomy appliance worn by a user. The outer edges are the edges farthest away from the stoma in the plane of the abdominal surface. The top of the filter case or part of it will be the point or plane farthest away from the stoma in the axial direction - that is, perpendicular to the plane of the abdominal surface. The bottom will be the plane or point closest to the abdominal surface. Using these definitions, the distance d between the first and second part is in the axial direction.

The first and second part of the filter case may be integral with each other. In a related embodiment, the first part and the second part are connected with a hinge. The first part and the second part may also be attached to each other in a number of different ways. They may be attached to each other with a permanent attachment such as glue or a weld. This ensures a good, well-sealed durable attachment.

They may also be attached to each other with a click-fitting mechanism. In a related embodiment, the first part is attached to the second part by pins on one of the parts, the pins being adapted for cooperating with holes on the other part.

In another embodiment, the two parts are attached to each other with a snap-fitting mechanism.

The first or second part of the filter case may be provided with a protruding flange at the inner edge adapted for cooperating with a part of a coupling. A regular mechanical coupling may have a projecting edge on one part for catching a flange on the other part of the mechanical coupling. Providing the filter case with a protruding flange allows it to be attached to a part of a regular mechanical coupling without alterations on the mechanical coupling. The filter case may further comprise a membrane element of a microporous membrane material. It is an advantage if the membrane material is hydrophobic so that it repels liquid. At the same time it has to allow gas to pass through it. One example of a material is GORE-TEX ^® . Another example is a hydrophobic and oleophobic microporous membrane.

The second part of the filter case may have a top and a bottom in the axial direction so that the bottom of the second part is in contact with the filter holding space. In an embodiment, the inlets to the filter are placed at the top of the second part.

The bottom of the second part is closest to the wafer and thereby to the stoma, whereas the top of the second part is farthest away from the stoma. When the inlets to the filter are placed at the top of the second part, they are placed in the position at the filter case that faces away from the exit of the stoma. Thereby, the inlets are least prone to be covered in faeces when exiting the stoma.

In another embodiment, the inlets to the filter are placed at the inner edge. When the inlets to the filter are placed at the inner edge, the gas, that may include liquid, must travel around an approximately 90 degree bend. Therefore, the liquid will have a tendency to be collected at the bend, thus preventing it from reaching the filter element. The number of inlet holes may be between 15 and 20. However, it is not so much the number as the area of inlet holes that is of significance in relation to the filtering capacity. The area of the inlet holes should be as large as possible without leading to collapsing of the structure. The outlet of the filter case may be provided as one clearance between the first outer edge and the second outer edge. The clearance extends all the way around the outer edges of the filter case. In another embodiment, the filter case is provided with several outlets in form of discrete holes at the outer edges of the filter case.

Another aspect of the invention relates to a two-piece ostomy appliance comprising

- a wafer for adhering to the skin having a first coupling part,

a collecting bag for collecting output from a stoma having a second coupling part, o the first and second coupling parts are adapted for cooperating with each other to enable fastening of the collecting bag to the wafer,

^■ wherein a filter case, as described above, is interposed between the first and second coupling parts.

Incorporation of the filter case in a coupling for a two-piece ostomy appliance eliminates the need for an additional filter anywhere on the bag. Furthermore, a traditional filter case or filter package can be omitted, which is an advantage in relation to manufacturing.

Usually, when changing the bag in a two-piece appliance, also the filter is discarded because it is part of the bag. When using a two-piece appliance having the filter in the coupling, the filter need not be discarded when the bag is changed but may be re-used until it is time to change the wafer with the coupling.

In an embodiment, the first coupling part is 10 mm smaller in diameter than the second coupling part. Using two different sized couplings provides for an ostomy appliance having a coupling height (almost) like a regular two-piece appliance. This is because the filter case can be placed in the interspace between the first coupling part and the second coupling part.

In another embodiment, the first coupling part corresponds in size to the second coupling part. In that case, the user can use the same size bag and wafer. A drawback may be that the coupling takes up a little more room in the axial direction. The appliance may also be used with a locking ring. In that case, the locking ring will be placed on the side of the carbon filter facing the adhesive wafer. Thereby, the filter case can be locked to the wafer thus reducing the risk of the filter case being separated from the adhesive wafer. Brief Description of the Drawing

Figure 1 illustrates the different parts in a filter case according to the invention; the two coupling parts are also shown.

Figure 2 illustrates the different parts attached together in a filter case according to the invention; again including the two coupling parts. Figure 3 illustrates an embodiment of a filter case according to the invention, including the two coupling parts, where the coupling parts correspond in size to each other.

Figure 4 illustrates an alternative placing of the inlets in a filter case according to the invention.

Figure 5 illustrates an embodiment of a filter case according to the invention, where the first part of the filter case is adapted for use with a locking ring to a coupling.

Detailed Description of the Drawing

Figures 1 and 2 illustrate a first embodiment of a filter case 100 according to the invention. Figure 1 illustrates an exploded view and figure 2 illustrates the parts attached to each other. The filter case 100 is shown with a regular mechanical coupling for an ostomy bag. The mechanical coupling includes a wafer coupling part 120 for attaching to a wafer (not shown) and a bag coupling part 130 for attaching to a bag (not shown). The wafer coupling part 120 will be welded or glued to the wafer, and the bag coupling part 130 will be welded or glued to the bag. Such mechanical couplings are well-known in the art, and they will only be briefly described in the following. The wafer part 120 has a collar 121 , which is welded to the wafer when the coupling is to be used. A central circular rim 122 is upstanding from the collar 121. This rim 122 had a projecting edge 123 on the outer periphery 124. The wafer coupling part 120 is rather rigid and not likely to flex too much. The bag coupling part 130 comprises a circular flexible annular element coupling element 131. Typically the bag coupling part 130 will also include a locking ring (not shown in figure 1 ) which is an annular element adapted for closing and providing a clamping effect around the flexible element 131. The flexible element 131 is substantially U-shaped in cross-section to provide a groove 132 for fitting the locking ring. The flexible element 131 has a collar 133 for welding or gluing to the collecting bag of an ostomy appliance. When a filter case is not inserted between the wafer coupling part and the bag coupling part, and the two parts are the same size, then the projecting edge 123 will grip a flange 134 on the flexible element 131 of the second coupling part 130. Locking the locking ring around the flexible element will provide a secure locking of the wafer and bag coupling parts 120, 130 to each other.

The filter case 100 of the invention is adapted for being interposed between the wafer coupling part 120 and the bag coupling part 130. The filter case has a first part 101 and a second part 102, which, when attached to each other, provides a filter holding space 103 between them (see figure 2). In figure 1 , a filter element 104 is shown to illustrate the purpose of the filter holding space. In figure 2, the filter element 104 is shown in the filter holding space 103. A membrane 105 is also shown in figures 1 and 2. The membrane 105 is used for protecting the filter element 104 from liquid. The first part 101 is provided with projecting pins 106 for cooperating with holes (not shown) in the second part 102. This is one way of attaching the first and second part to each other. As described earlier, a variety of attaching means can be used. The first part 101 has a cavity 107, which constitutes one part of the filter holding space 103. The second part 102 has the counterpart - also in form of a cavity 108. The first part has an inner edge 109 and an outer edge 110. Likewise, the second part has an inner edge 111 and an outer edge 112. The second part has a top 113 and a bottom 114 in a direction transverse to the extent between the inner edge 111 and the outer edge 112 - that is in the axial direction. In the embodiment of figure 1 and 2, the inlet holes 115 to the filter case is placed in the top 113 of the second part 102. Only a few holes can be seen in figure 1 , but in principal several holes would be placed around the top of the second part. The inlet holes communicate with through-going channels 116 from top 113 to bottom 114 of the second part. The channels 116 communicate with the filter holding space 103. This way gas flow will be able to flow through the inlet holes 115 and the channels 116 to the filter holding space 103 where the gas flow will be filtered by the filter element 104 placed in the filter holding space 103. Between the outer edges 110 and 112, a clearance 117 is provided. This clearance 117 functions as a round-going outlet from the filter case 100. So in this embodiment, the filter case is provided with only one outlet extending all the way around the outer edge. As illustrated in figure 2, the inner edges 109, 111 of the first and second parts are not completely aligned. The inner edge 109 of the first part 101 has a protruding flange 118 with respect to the inner edge 111 of the second part 102. This protruding flange 118 constitutes the flange for cooperating with the projecting edge 123 on the wafer coupling part 120. Thereby the wafer coupling part 120 can be coupled with the first part 101 of the filter case. Likewise, the second part 102 of the filter case is provided with a projecting edge 119 for cooperating with the flange 134 on the bag coupling part. So the bag coupling part 130 can be coupled to the second part 102 of the filter case. It appears from the figures that the wafer coupling part 120 has a smaller diameter than the bag coupling part 130. As an example, the wafer coupling part 120 is a 40 mm coupling and the bag coupling part is a 50 mm coupling. This sizing-up provides room between the two coupling part in the transverse direction for the filter case 100.

Figure 3 illustrates another embodiment of the filter case 200 in cooperation with a coupling for an ostomy bag. The same reference numbers as in figures 1 and 2 will be used for similar parts - except for the prefix 2 instead of 1. The difference between this embodiment and the one in figures 1 and 2 is that this filter case 200 is adapted for use with a coupling where the wafer coupling part 220 has a diameter corresponding to the second bag part 230. Thus, in this embodiment the wafer coupling part 220 has a first part 220a welded or glued to the wafer (not shown) and a second part 220b welded or glued or otherwise fitted to the filter case 200. Likewise, the bag coupling part 230 has a first part 230a welded or glued to the bag (not shown) and a second part in form of a projecting edge 219 as part of the filter case 200. Therefore, the wafer coupling part 220 has to be placed below the filter case. Adaptations can be made to the second part 220b of the wafer coupling part 220 to make it fit better to the first part 201 of the filter case - however, for illustrative purposes it is shown similar to the coupling part of figures 1 and 2. The wafer coupling part and the first part of the filter case can be glued or welded together. They may also be attached by click-fitting. The second part 202 cooperates with the first part 230a of the bag coupling part the same way as described in relation to figures 1 and 2. In figure 3, the filter case 200 is shown without the membrane and the filter element. The filter holding space 203 is illustrated in the figure. Likewise it is shown that at the inlets 215, there may be a groove 215a for providing room for the membrane. From the inlets 215 gas flows through the channels 216 to the filter holding space 203 to be filtered by a filter element placed there (not shown).

Figure 4 illustrates an embodiment very similar to the embodiment of figures 1 and 2. The same reference numbers as in figures 1 and 2 will be used for similar parts - except for the prefix 3 instead of 1. The only difference is that in this filter case 300, the inlets 315 to the filter case are placed at the inner edge 311 of the second part 302. A groove 315a is also provided for making room for the membrane.

Regarding figure 5, this figure illustrates an embodiment of a filter case 400 according to the invention. The filter case 400 of this embodiment has room for a locking ring below the filter holding space 403. Like with the embodiment in figure 3, there are extra coupling parts in this embodiment. The wafer coupling 420 has a first coupling part 420a and a second coupling part 420b. Likewise, the bag coupling 430 has a first coupling part 430a and a second coupling part in form of a projecting edge 419. The wafer coupling 420 may in this embodiment be provided with a locking ring (not shown) inserted in the first coupling part 420a. The locking ring minimises the risk of decoupling the coupling part at the wafer.