GB2329838A

GB2329838A - Ostomy coupling

Info

Publication number: GB2329838A
Application number: GB9720815A
Authority: GB
Inventors: Barrie Thomas Mills; Rory James Maxwell Smith
Original assignee: Welland Medical Ltd
Current assignee: Welland Medical Ltd
Priority date: 1997-10-01
Filing date: 1997-10-01
Publication date: 1999-04-07
Also published as: GB9720815D0

Abstract

An adhesive coupling device for securing an ostomy device to a patient comprising: first and second annular members 34, 18 for attachment to the patient and the bag respectively, having upstanding rims 38, 24 surrounded by bonding regions 36, 22, wherein the rims are configured to be received concentrically into one another and the bonding regions form an adhesive bond; one of the annular members being provided with locating means to guide the annular members towards concentric engagement 41; characterised in that a surface of an upper portion of a side of one of the annular rims confronting the other annular rim is inclined away from the other said annular rim to define a lead in surface to guide the annular rims towards each other.

Description

OSTOMY BAGS This invention relates to ostomy bags and more particularly to coupling devices for fastening ostomy bags to a patient's body.

The use of ostomy bags, such as ileostomy and colostomy bags, to collect bodily waste draining from a stomal opening in the patient's body wall, is well known. Ostomy bags can be secured to the patient by means of a belt or strap, but more usually they are affixed to the patient by means of an adhesive flange which surrounds the stomal orifice. Typically the adhesive flange has a layer of a dermatologically compatible hydrocolloid adhesive. Although the hydrocolloid adhesives are relatively benign, repeated application and removal of fresh adhesive flanges can cause irritation and discomfort to the patient and, for this reason, in situations where an ostomy bag needs to be changed frequently, a two-piece bag is used. Such two-piece bags typically consist of a two-part connector, one part of which has the adhesive flange attached thereto, and the other part of which is attached to the ostomy bag. With such an arrangement, the adhesive flange may be left in position on the patient's skin whilst the ostomy bag can be replaced as required.

A disadvantage with existing two-part connectors is that they are frequently formed from a relatively rigid material, and have a high profile which means that they can be seen through the patient's clothing. In addition, they can be somewhat uncomfortable, as well as being relatively cumbersome to use. Some devices use a locking ring arrangement which requires accurate positioning and good manual dexterity. This can pose problems for people who have impaired manual dexterity.

At the present time, there remains a need for a two-piece ostomy bag in which the two-part connector is relatively flexible, has a low profile and cannot be seen through the patient's clothing, and which is comfortable to wear. It is an object of the present invention to provide such an arrangement.

Accordingly, in a first aspect, the provides a coupling device for securing an ostomy bag to a patient; the device comprising: (i) a first annular member having on one side thereof an adhesive for temporarily adhering the first annular member to the patient's skin about a stomal opening, and on the other side thereof having a first upstanding annular rim, and a first annular bonding region surrounding the first upstanding annular rim; and (ii) a second annular member for securing to an ostomy bag, the second annular member having a second upstanding annular rim surrounded by a second annular bonding region; the first and second upstanding annular rims being configured to allow one to be received concentrically within the other when the first and second annular members are brought together, one of the first and second annular members being provided with locating means radially spaced apart from its upstanding annular rim; the locating means being configured to engage a surface of the other annular member to guide the first and second upstanding rims towards a concentric arrangement; the first and second annular members when brought together co-operating to form a substantially water-tight seal, and the first and second annular bonding regions thereof being provided with means for forming a releasable adhesive bond therebetween; characterised in that a surface of an upper portion of a side of one of the annular rims confronting the other annular rim is inclined away from the said other annular rim to define a lead in surface to guide the annular rims towards concentricity.

In a second aspect, the invention provides an ostomy bag comprising a coupling device as hereinbefore defined.

The combination of an inclined lead in surface on one of the annular rims, and the locating means facilitates correct positioning of the two annular members before the adhesive contact between the two bonding regions takes piace. This is particularly important in cases where the patients using the ostomy bag have impaired or reduced manual dexterity or where, for example because of obesity or poor sight, it is difficult for the patient to see the ostomy coupling clearly.

An advantage of arranging the sealing members concentrically is that it is possible to reduce the height of the coupling device which in turn means that it is not so visible through the patient's clothing.

In order to further assist the patient in coupling the two annular members together correctly, the first and second upstanding annular rims are preferably provided with resilient latch means for holding the rims together.

The resilient latch means can take the form of formations on the two annular rims which co-operate to form a snap-fit engagement.

For example, one of the annular rims can be provided with a deflectable seal and the other annular rim can be provided with a ledge or ridge, the deflectable seal being deflectable to enable it to be snapped over the ledge or ridge.

The ledge or ridge can have an inclined leading surface along which the deflectable seal can slide in one direction, and a trailing abutment surface which serves to prevent or hinder movement of the deflectable seal in the opposite direction, thereby holding the two annular rims together.

It is preferred that one of the annular bonding zones has a layer of a releasable adhesive thereon, the releasable adhesive preferably being in the form of an adhesive tape which engages a release tape on the other annular bonding region.

The annular bonding zones are preferably defined by substantially flat annular surfaces which are generally perpendicular with respect to at least the lower portions of the upstanding annular rims.

The first and second annular members are preferably formed of a flexible polymeric material, and examples of such material include ethylvinylacetate copolymer (EVA). It is preferred that both the first and second annular members are formed from the same polymeric material (e.g.

EVA).

According to the invention, one or other of the first and second annular members is provided with locating means for assisting correct positioning of one of the annular members with respect to the other. The locating means can take the form of a guide wall or guide lugs attached to one of the annular members, which guide walls or guide lugs are disposed about the periphery of one of the annular members so as to guide the other annular member into a position of concentricity at which the first and second sealing members can be engaged in sealing contact.

In its simplest form, the guiding lugs or guiding means can be defined by a pair of guide lugs at spaced apart locations on the outer periphery of one of the annular members, and preferably the first annular member.

Alternatively, the guide means can take the form of an arcuate guide wall extending between two spaced apart points on the periphery of the annular member.

The first annular member has on one side thereof an adhesive for temporarily adhering the first annular member to the patient's skin. The adhesive is typically in the form of an adhesive flange or disc and may be formed from, for example, a hydrocolloid adhesive. Such adhesives are well known to those skilled in the art and their precise composition need not be described here. One problem facing the skilled man is to ensure that the adhesive flange is fixed to the first annular member in a secure manner without causing buckling or distortion of the flange. The first and second annular members are generally formed from a plastics material and typically are attached to the adhesive flange by welding, e.g. RF welding. However, as a result of the pressure that is exerted by the welding tool on the annular member in order to form a sufficiently strong weld to the underlying adhesive flange, distortion of the flange can result which in turn can adversely affect the adhesion properties of the flange.

The present invention provides a means of reducing or overcoming this problem by providing welding intensifier formations on the bodyside surface of the first annular member. The welding intensifier formations typically take the form of one or more annular ridges extending around the bodyside surface. The annular ridges can, for example, have relatively sharp edges for biting into the underlying adhesive flange, or they can have a radiused or more rounded profile. The ridges can be, e.g. of rectangular, semicircular or substantially triangular form in cross-section, by way of example.

The invention will now be exemplified by reference to the particular embodiments shown in the accompanying drawings Figures 1 to 10; in which Figure 1 is a sectional elevation through an ostomy coupling according to one embodiment of the invention; Figure 2 is an enlarged sectional view of part of the ostomy coupling of Figure 1; Figure 3 is an enlarged sectional view corresponding to Figure 2 but showing the coupling in a detached condition; Figure 3a is an enlarged sectional view of the region marked A in Figure 1; Figure 4 is a view from one side of an ostomy bag incorporating part of the coupling of Figures 1 to 3; Figure 5 is an exploded view of the ostomy bag shown in Figure 4; Figure 6 is a view from one side of an adhesive flange incorporating part of the coupling of Figures 1 to 3; Figure 7 is an exploded view of the adhesive of flange of Figure 6; Figure 8 is an enlarged view of the portion marked B in Figure 1; Figure 9 is a sectional elevation through part of the ostomy coupling of Figures 1 to 3 showing the application of loading forces in a detachment test; and Figure 10 is a graph showing the results of detachment tests.

Referring now to the drawings, an ostomy bag according to one embodiment of the invention is formed from front 2 and rear 4 sheets of a tough waterproof multilaminar film material comprising a layer of polyvinylidene dichloride and optionally one or more further barrier layers sandwiched between two layers of ethylenevinylacetate (EVA). Such film can be obtained from W. R. Grace GmbH of Larderstedt, Germany. Sheets 2 and 4 are sealed together around their peripheral margins 6 and 8 by welding, for example RF welding. A third layer 10 which is a comfort layer formed from a non-woven material is secured to sheet 2, again by means of welding around its peripheral margins 1 2. Sheets 2 and 10 have generally circular openings 14 and 16 respectively through which bodily waste from the stomal orifice of a patient can pass. Welded to sheets 2 and 10 and surrounding the openings 14, 16 is an annular member (hereinafter referred to as the second annular member) 18 formed from a flexible grade of EVA.

Second annular member 18 has a semi-circular tab 20, the purpose of which will be apparent from the description below.

Affixed to the second annular member 18 by means of heat sealing is a refastenable adhesive tape 22. The outwardly facing adhesive layer is normally covered with an annular release paper 23. The refastenable adhesive tape 22 forms one half of a refastenable tape arrangement of the type available from the Minnesota Mining and Manufacturing Company.

The second annular member is shown in cross-section in Figure 2 and Figure 3 from which it will be noted that surrounding the central opening is an upstanding annular rim 24 extending in the direction of the ostomy bag interior. Disposed radially inwardly of the annular rim 24 is a deflectable seal 26 which extends around the entire inner circumference of the annular rim 24. The deflectable seal is formed integrally with the second annular member 18.

Referring now to Figures 6 and 7, the adhesive flange 30 is provided with a backing layer coated with hydrocolloid adhesive which serves to adhere the flange to the skin of a patient about the stomal orifice. Adhesive flange 30 has a generally semi-circular tab 32 to assist in removal of the flange after use. Mounted on the adhesive flange by ultrasonic welding is an annular member (hereinafter referred to as the first annular member) 34 which is formed from the same or similar EVA material as the second annular member 18 attached to the ostomy bag. Secured to the first annular member 34 is an annular release layer 36 to which the refastenable adhesive tape 22 on the ostomy bag can be releasably attached.

The first annular member 34 is shown in cross-section in Figures 2 and 3. As can be seen, the first annular member 34 has an upstanding annular rim 38 which in this embodiment has a lower portion 39 extending substantially perpendicularly from the main body of the annular member, and an upper portion 40 which is inclined radially inwardly and away from the annular rim 24 of the second annular member.

The upper portion 40 has a radially inwardly inclined outer surface 41 which is radiused at its upper end 41 a. The lower portion 39 and upper portion 40 are separated by an annular ledge 42, the shape of which can be seen more clearly in Figure 3a. As shown in Figure 3a, the annular ledge 42 has an inclined and slightly curved leading surface 42a and a trailing abutment surface 42b. As will be apparent below, the deflectable seal 26 and the ledge 42 co-operate to form a snap-fit connection to prevent or reduce the possibility of accidental separation of the first and second annular members.

The main body of the first annular member 34 has secured to the rear surface thereof a backing layer 44 formed from a non-woven material to which in turn is affixed the hydrocolloid adhesive 46 by means of RF welding. A release paper 48 covers the hydrocolloid adhesive prior to use.

Attached to the front surface of the main body of the first annular member is the release layer 36.

In order to enhance the welding of the first annular member 34 to the backing layer 44 and hydrocolloid adhesive 46, the underside of the annular member is provided with welding intensifiers 50. The welding intensifiers are shown in more detail in Figure 8, from which it can be seen that they comprise annular ridges of generally triangular cross-section and having a relatively sharp edge 52. When pressure is applied to the surface of the first annular member 34 using the welding tool, the edges 52 of the welding intensifiers dig into the underlying backing layer 44 and hydrocolloid adhesive layer 46 to provide for an enhanced weld. By means of the welding intensifiers, the tendency of the adhesive flange to buckle or distort under the pressure of the welding tool is greatly reduced or avoided altogether. Although shown as being sharp edged, the edges of the welding intensifiers can instead be radiused.

As shown in Figures 6 and 7, the first annular member 34 has an arcuate guide wall 54 at a position radially spaced from the upstanding annular rim 38. Instead of the single arcuate guide wall, alternative locating means could be provided in the form of an array of spaced guide lugs. It will be appreciated that the guide wall 54, although shown as being continuous, could also consist of an array of discontinuous arcuate guide elements or guide lugs.

In use, the patient removes the release paper 48 from the rear surface of the hydrocolloid flange 30, the central hole 56 being cut to the appropriate size to accommodate the protruding end of the stoma. The flange 30 is then adhesively fixed in place about the stomal opening.

The ostomy bag is connected to the adhesive flange by bringing the first annular member 34 and second annular member 18 together so that the upstanding annular rim 24 and deflectable seal 26 of the second annular member sit about and seal against the upstanding annular rim 38 of the first annular member, thereby providing a substantially water-tight seal between the collar 24 and rim 38. At the same time, the adhesive tape on the second annular member 1 8 engages the release layer 36 on the first annular member 34 to form an adhesive union between the first and second annular members. In so doing, the ostomy bag is coupled to the adhesive flange.

Correct location of the second annular member 18 on the first annular member 34 is ensured by means of the guide wall 54 which engages an edge 58 of the second annular member as the two annular members are brought together. As a result of the arcuate shape of the annular guide wall 54, the second annular member is guided towards a position of concentricity with the first annular member. The inclined lead in surface 41 of the upstanding annular rim 40 further assists correct location of the second annular member. Thus an advantage of the ostomy coupling of the invention is the ease with which the two annular members can be connected together by patients having reduced or impaired manual dexterity, or patients who, for various reasons, find it difficult to see the coupling in clear detail.

The presence of the ledge 42 further serves to ensure that the patient knows when the ostomy coupling has been correctly fitted together. Thus, as the first and second annular members are brought together, the deflectable seal 26 slides along inclined surface 41, over leading surface 42a of the annular ledge, and then snaps into position against the lower portion 39 of the upstanding rim 38. The trailing abutment surface 42b of the ledge 42 then serves to inhibit inadvertent separation of the first and second annular members.

It has been found through experiments that by means of the ledge 42, the degree of force needed to separate the first and second annular members is greatly increased. A comparison was made between ostomy couplings in which the first annular rim was generally perpendicular to the main body of the annular member, and ostomy couplings having an annular rim having the geometry set out in the foregoing Figures. Thus, first annular members having straight or stepped (ledged) upstanding annular rims were welded to 105mm x 0.9mm hydrocolloid flanges, and to each of the first annular members was attached a second annular member fixed to an ostomy bag as shown in the Figures, except that the adhesive tape was omitted. The ostomy couplings were then attached to the "T" frame of a tensile testing machine using the hydrocolloid flange and a load L was applied to the bag material 60 to emulate the load applied in normal use. The load required to separate the two annular members was recorded for each of the samples.

The results are shown in the Table in Figure 10, and in Table 1 below.

Table 1

ii I I I I I Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 straight annular rim 15.38 15.07 13.13 15.11 14.62 Ledged inclined 22.24 20.47 20.72 20.55 20.19 annular rim As will be seen from the results shown in the Table and the graph, an average increase in force of 42% was required to separate the couplings of the present invention, compared with couplings having a straight annular rim.

In time, the ostomy bag of the invention will fill up with stomal waste products and will require changing. Rather than remove the entire assembly, the ostomy bag is removed from the adhesive flange by separating the first and second annular members. The semi-circular tabs 20 and 32 can be grasped to assist in the pulling apart of the two annular members. Pulling the tabs assists in deforming the first and second annular rims such that the deflectable seal can be lifted over the ledge 42. The ostomy bag can then be discarded and a fresh ostomy bag coupled to the adhesive flange.

The advantage of the arrangement illustrated in the drawings is that it is not necessary to tear the adhesive flange away from the patient's skin each time it is necessary to change the ostomy bag. Therefore, much of the irritation and discomfort associated with the fitting and removal of the ostomy bag can be avoided.

The ostomy bag arrangement shown in the drawings is particularly advantageous in that it is formed from a flexible material and is therefore more comfortable to the patient than existing coupling arrangements formed from more rigid materials. In addition, in many existing two-part coupling arrangements, a mechanical snap-fit fastening arrangement is employed which comprises an upstanding rim on one half of the connector over which a locking ring is snapped. The result is a rather bulky union which is often visible through the patient's clothing. With the present invention, the total height of the two annular members when fitted together is no more than 5mm and can be as little as 3mm. This contrasts with known arrangements in which the two coupling halves are superimposed rather than arranged concentrically and as a result have coupling arrangements 6mm or more in depth.

It will readily be apparent that numerous modifications and alterations can be made to the ostomy bag coupling device shown in the accompanying drawings without departing from the principles underlying the invention and all such modifications and alterations are intended to be embraced by this Application.

Claims

CLAIMS 1. A coupling device for securing an ostomy bag to a patient; the device comprising: (i) a first annular member having on one side thereof an adhesive for temporarily adhering the first annular member to the patient's skin about a stomal opening, and on the other side thereof having a first upstanding annular rim, and a first annular bonding region surrounding the first upstanding annular rim; and (ii) a second annular member for securing to an ostomy bag, the second annular member having a second upstanding annular rim surrounded by a second annular bonding region; the first and second upstanding annular rims being configured to allow one to be received concentrically within the other when the first and second annular members are brought together, one of the first and second annular members being provided with locating means radially spaced apart from its upstanding annular rim; the locating means being configured to engage a surface of the other annular member to guide the first and second upstanding rims towards a concentric arrangement; the first and second annular members when brought together co-operating to form a substantially water-tight seal, and the first and second annular bonding regions thereof being provided with means for forming a releasable adhesive bond therebetween; characterised in that a surface of an upper portion of a side of one of the annular rims confronting the other annular rim is inclined away from the said other annular rim to define a lead in surface to guide the annular rims towards concentricity.
2. A coupling device according to claim 1 wherein the first and second upstanding annular rims are provided with resilient latch means for holding the rims together.
3. A coupling device according to claim 2 wherein the resilient latch means take the form of formations on the two annular rims which co operate to form a snap-fit engagement.
4. A coupling device according to claim 3 wherein one of the annular rims is provided with a deflectable seal and the other annular rim can is provided with a ledge or ridge, the deflectable seal being deflectable to enable it to be snapped over the ledge or ridge.
5. A coupling device according to claim 4 wherein the ledge or ridge can has an inclined leading surface along which the deflectable seal can slide in one direction, and a trailing abutment surface which serves to prevent or hinder movement of the deflectable seal in the opposite direction, thereby holding the two annular rims together.
6. A coupling device according to any one of the preceding claims wherein one of the annular bonding zones has a layer of a releasable adhesive thereon.
7. A coupling device according to claim 6 wherein the releasable adhesive is in the form of an adhesive tape which engages a release tape on the other annular bonding region.
8. A coupling device according to any one of the preceding claims wherein the annular bonding zones are defined by substantially flat annular surfaces which are generally perpendicular with respect to at least the lower portions of the upstanding annular rims.
9. A coupling device according to any one of the preceding claims wherein the first and second annular members are formed of a flexible polymeric material.
10. A coupling device according to claim 9 wherein both the first and second annular members are formed from the same polymeric material.
11. A coupling device according to any one of the preceding claims wherein the locating means takes the form of a guide wall or guide lugs attached to one of the annular members, which guide walls or guide lugs are disposed about the periphery of one of the annular members so as to guide the other annular member into a position of concentricity at which the first and second sealing members can be engaged in sealing contact.
12. A coupling device according to claim 11 wherein the guiding lugs or guiding means is defined by a pair of guide lugs at spaced apart locations on the outer periphery of one of the annular members.
1 3. A coupling device according to claim 1 2 wherein the guiding lugs or guiding means is defined by a pair of guide lugs at spaced apart locations on the outer periphery of the first annular member.
14. A coupling device according to any one of claims 1 to 11 wherein the guide means takes the form of an arcuate guide wall extending between two spaced apart points on the periphery of the annular member.
1 5. A coupling device according to any one of the preceding claims wherein the adhesive on the said one side of the first annular member is in the form of an adhesive flange or disc.
16. A coupling device according to claim 15 wherein the adhesive flange or disc is formed from a hydrocolloid adhesive.
1 7. A coupling device according to any one of the preceding claims wherein welding intensifier formations are provided on the bodyside surface of the first annular member.
1 8. A coupling device according to claim 17 where the welding intensifier formations take the form of one or more annular ridges extending around the bodyside surface.
1 9. A coupling device substantially as described herein with reference to the accompanying drawings.
20. An ostomy bag comprising a coupling device as defined in any one of the preceding claims.