GB2302028A - Deodorising filter for ileostomy pouch - Google Patents

Abstract

The filter has a region through which ileal fluid of slurry-like consistency passes, at least a part of such region containing a non-woven or foam substrate 34 carrying superabsorbent material such as powder 36. The filter may particularly comprise a layer A as above and a layer B of charcoal cloth sandwiching a layer C of gas- and liquid-impervious polyolefine, such filter being cut out of roll stock obtained by laminating the said layers under heat and pressure or with the use of adhesive. In an alternative embodiment, the filter has three adjacent compartments through which ileal fluid passes sequentially, one of the compartments being part filled with superabsorbent powder.

Description

ILEOSTOMY POUCH AND FILTER This invention relates to an ileostomy pouch and filter.

According to the invention, there is provided an ileostomy filter having a region such as a compartment through which ileal fluid (which is usually of a loose slurry-like consistency) passes, characterised in that part or all of said region contains a non-woven substrate bearing a superabsorbent powder.

With such an arrangement, the superabsorbent powder removes liquid from the material passing through the region, so reducing the possibility that the filter will become blocked or "blinded" by the ileal slurry passing therethrough.

In an alternative embodiment of the invention, a compartment of an ileostomy filter may be part-filled with a superabsorbent powder which is positioned so that a clear pathway for ileal fluid is provided between entrance and exit of the compartment. Suitable means may be employed for retaining the powder in position.

In an advantageous embodiment of the invention, an ileostomy filter embodies a composite structure arranged so that the ileal fluid first passes through a charcoal medium and then through a layer of superabsorbent material in its path through the filter. According to an especially advantageous aspect of this embodiment, a roll stock can be produced out of which composite filter discs can be cut or stamped. In this way, reliable and economic manufacture of suitable filter discs, suitable for employment in an ileostomy pouch, can be achieved.

Various superabsorbents in powder or other solid form may be used, for example: - (a) a superabsorbent material which may be described chemically as having a backbone of natural or synthetic polymers with hydrophilic groups or polymers containing hydrophilic groups being chemically bonded to the backbone or in intimate admixture therewith. Included in this class of materials are such modified natural and regenerated polymers as polysaccharides including, for example, cellulose and starch and regenerated cellulose which are modified by being carboxylated, phosphonoalkylated, sulphoalkylated or phosphorylated to render them highly hydrophilic. Such modified polymers may also be crosslinked to improve their water-insolubility.

(b) a superabsorbent material, preferably in powder form, namely polymers on the basis of polysaccharides, such as cellulose, cellulose derivatives such as carboxymethylcellulose, alkyl- or hydroxyalkylcellulose, starch and starch derivatives and vegetable gums (e.g. xanthan gum), alginic acid and its salts, and also the polymers or copolymers on a basis of (meth)acrylic acid or (meth)acrylic acid derivatives, these being primarily the homopolymers or copolymers of acrylic, methacrylic, acrylamidomethyl-propanesulfonic acid, or of the salts of these acids, or of acrylamide or methacrylamide with one another or with vinylpyrrolidone and/or vinyl acetate. The above polymers can be cross-linked by an at least bifunctional cross-linking agent, so that they can only be softened by water, but will not be soluble. All of these polymers can be made by known methods.

(c) water-insoluble, water-swellable polymers which have an enhanced capacity for removing water or aqueous fluids. The water-insoluble waterswellable polymers are lightly cross-linked polymers containing a plurality of hydrophilic groups, such as carboxyl, carboxamide, sulfonate salt or hydroxyl groups, along the polymer chain in sufficient proportions so that the polymer would be water-soluble if it were not for the cross-linking thereof.

The invention will be better understood from the following non-limiting description of an example thereof given with reference to the accompanying drawings in which: Figures la to ic illustrate (a) one embodiment of an ileostomy filter device viewed from the gas outlet side, (b) a cross section along the longest axis of the device and (c) the device viewed from the gas inlet side; Figure 2 is a schematic illustration of a passageway portion of the ileostomy filter device shown in Figure 1; Figure 3 illustrates a composite laminated sheet which can be wound into roll stock; and Figure 3A is a cross-section therethrough; Figure 4 is a view of a filter disc which may be cut or stamped out of the sheet shown in Figure 3; Figure 5 illustrates the upper part of an ileostomy pouch which embodies a filter according to the invention; and Figure 6 is a view in greater detail and on a larger scale showing one arrangement of the filter mounted in the pouch.

An ileostomy filter device in accordance with one embodiment of the present invention has three adjacent compartments 5, 6 and 7, where the ileal fluid and gas enters the device through a perforated opening 4 on the end of the device in the bottom 9, circulates from compartment 5 to compartment 6 through an opening 15 in the lower division plate 10 at the device's opposite end, circulates back and into compartment 7 through an opening 16, located in the upper division plate 11 at the first end, immediately above the gas inlet 4, and flows on into compartment 7 towards the device's other end and leaves the device through gas outlet 8, located near the other end. The openings are located with mutual maximum distance between each opening. Provision may be made for attaching the device to an ostomy pouch.A channel-section portion 17, 18, 19 may be attached to a member (not shown) carrying a rib which can make a snap fit with the channel 17, 18, 19. The reader is referred to British Patent No. 1,571,657 for a fuller description of one preferred form of channel-rib engagement.

Figure 2 schematically illustrates a passageway portion of the ileostomy filter device. This portion has an entrance 30 and an exit 32. A foam substrate or a non-woven substrate 34 is disposed at one side (the right-hand side as seen) of the passageway, and the particles of a powdered superabsorbent 36 are caused, by vacuum drawing, to be forced into the substrate. The substrate may be, but need not be, preloaded with activated carbon or charcoal particles. As schematically illustrated by the arrow 37, gas plus liquid (ileal fluid) enters at the entrance 30. As illustrated by the arrows 38, liquid is drawn from the flow into the superabsorbent, leaving mainly gas 40 to continue to the next portion of the filter device.

Referring now to Figures 3, 3A, and 4, the roll stock comprises a substrate A of non-woven fabric-like plastics material which carries or is loaded with a superabsorbent powder, and sandwiched between the substrate A and a layer of charcoal cloth is an impervious polyolefinic layer. Instead of charcoal cloth, a layer of any other suitable odour-apsorbing material could be employed.

Alternatively a layer of a material loaded with a substance such as a fragrance which masks the smell of the discharge could be used. These three layers are laminated together by a conventional laminating procedure into roll stock using heat and pressure; an open matrix adhesive could alternatively be used to join them together. Figure 4 illustrates a disc cut out of this roll stock.

As illustrated in Figures 5 and 6, according to a second, and presentlypreferred, embodiment of the invention, such a filter disc is embodied in an ileostomy pouch. The pouch 40 has a front wall 42 and a rear wall 44. In line with normal practice in manufacturing ostomy pouches, these walls are joined by a peripheral plastics weld seam. The rear wall 44 has a stomal orifice therein, which is surrounded by a coupling member 47 whereby the pouch can be attached to a medical grade adhesive pad which is itself adhesively secured to a peristomal area of the body of the wearer. Various forms of coupling member may be employed, for example those shown in British Patent No. 1,571,657; British Patent No. 2,206,801; British Patent 2,219,507; and British Patent 2,237,995. The wall 42 has a gas entry hole 50 which leads to a portion of the bag which contains a filter. One example of a suitable filter is shown in Figure 4 and comprises a substrate A and layers B and C. In the preferred embodiment of the invention layer A is a substrate comprising a non-woven fabric which carries or has embodied therein particles of superabsorbent powder, layer B is charcoal cloth or any other suitable odour-absorbing substrate and layer C is a gas-impervious and liquid-impervious polyolefinic layer. As seen in Figure 6, there is an encircling weld join 52 between the layer B and the wall 42 so that the ileal fluid including gas to be deodorised can only enter the layer B at its central region; it then flows radially outwardly as indicated by the arrows and then enters the substrate A at the exposed edge thereof. The polyolefinic layer C prevents any direct passage of this fluid to be deodorised from the layer B to the layer A.A plastics weld seam 54 secures a disc 55 of pouch film to the wall 42 and this disc serves as a filter housing wall. It has a hole 56 for exit of gas to ambient atmosphere. As the fluid, which may be a mixture of gas and liquid, is passing through the substrate A, any liquid is removed by the superabsorbent material or collects at the region indicated 59 in Figure 6. There is a generally circular plastics weld 60 between the surface of substrate A and the filter housing wall 55 to hold the filter appropriately in position in the pouch.

The arrangement illustrated in Figures 4-6 provides a particularly effective way of dealing with ileal fluid.

Of course modifications to the described arrangements can be made without departing from the invention. For example, while plastics welds are preferred for the connections illustrated at 52, 54 and 60, adhesive could be employed instead. While the film employed for layer C is preferably polyolefinic, other impervious films may be used instead. As illustrated, the disc A,B,C is substantially circular, but of course it could be oval or rectangular or any other convenient shape. The shape of the filter housing 55 would in that event of course be altered to suit. While the filter has been shown on the front wall 42, it could alternatively be located on the rear wall 44 (i.e. the wall nearest the body of the pouch wearer).

Claims (11)

1. An ileostomy deodorising filter having a region through which ileal fluid passes, characterised in that at least part of said region contains a non-woven substrate which carries or embodies a superabsorbent powder.

2. A filter according to claim 1 in which the superabsorbent is a polymer based on polysaccharides.

3. A filter according to claim 1 in which the superabsorbent is an alkali metal polymethacrylate.

4. A filter according to claim 1 which comprises at least three layers of which a first is a non-woven substrate carrying a superabsorbent powder, a second is a polyolefinic film, and a third is charcoal cloth.

5. A filter according to any one of claims 14 in which the substrate powder is vacuum-drawn into the substrate.

6. An ostomy pouch which has a filter according to any of claims 1-5 carried in a filter housing, the housing being defined by a wall of the pouch and a filter housing wall, there being a hole in the pouch wall allowing passage of ileal fluid from the pouch to the filter housing, and an exit hole permitting gas escape to atmosphere, the filter and filter housing being arranged so that (a) any fluid passing through the hole in the pouch wall is constrained to follow a labyrinthine path through the filter, and (b) liquid in said fluid is collected in a region at the lower part of the filter housing bounded by the pouch front wall and the filter housing wall.

7. An ileostomy pouch according to claim 6 in which front and rear walls thereof are plastics-welded together around their periphery, and a filter housing wall is secured to the said front wall.

8. An ileostomy pouch according to claim 7 in which the filter comprises the three layers A, B and C as specifically disclosed herein.

9. A method of making filters which comprises cutting or stamping out of roll stock a series of said filters; the roll stock being a laminated structure comprising at least three layers, namely layers A, B and C as specifically disclosed herein.

10. A deodorising filter for ileostomy sufferers substantially as herein described with reference to and as illustrated in the accompanying drawings.

11. Any novel combination or sub-combination of features disclosed and/or illustrated herein.