Ostomy coupling

Abstract: A coupling for joining a pad or dressing to an ostomy bag including a first member (10) of closed loop form for defining a stoma aperture therein, the first member having a formation which defines two opposed walls, (11, 12), and a second member (20) of closed loop form also defining a stoma aperture. The second member has a projection or wall (21) dimensioned and positioned to fit between and resiliently bear against at least one of the walls when the members are connected in such a way as to make sealing engagement with at least the said one wall. The first member is of channel formation seen in cross section and has an upstanding tapering rib (24) extending from the base of the channel and between its walls. The second member has a tapering groove, of substantially complementary shape to the rib, in that surface of the rib projection or wall (21) which faces towards the first member in the mutually coupled condition of the first and second members.

Description: This invention relates to a coupling for fixing an ostomy bag to a pad or surgical dressing. Such couplings have been proposed. Examples can be seen in British Patents Nos. 1 571 657 and 2 121 902. It has been found that the comfort in wear and security of attachment of the bag to the pad is seriously affected if it is possible for one coupling part to tilt relative to the other. In this context, "tilt" refers to a twisting possibly with partial deformation of a channel-shaped coupling member so that its planar surface, to which a medical grade adhesive pad is normally attached, lies substantially out of a plane located perpendicular to the axis of the coupling. It will be understood that an ostomy coupling normally has a circular stomal orifice, and the axis referred to is a line normal to the plane of that orifice and passing through the centre of the orifice. Such a tilt might be caused in use, for example, because the weight of the bag contents applies a force transverse to the coupling axis. A further example of an ostomy coupling is given in document EP-A-0 251 502, wherein the coupling comprises two members for attachment onto the patient's skin and the ostomy bag, respectively, and wherein the two members are connected essentially by inserting a tapering rib located on the first member into a groove located on the second member, whereby the rib forces a flange outwards to engage onto the wall of the first member. The coupling of the invention according to claim 1 is distinguished from this known coupling essentially in that also the groove is tapered and of substantially complementary shape to the rib having surfaces tapering at from 12 to 18 degrees to the rotation axis of the coupling. The aim of the present invention is to provide an ostomy coupling in which the possibility of tilt is eliminated or greatly reduced. According to the present invention, there is provided a coupling for joining a pad or dressing to an ostomy bag including a first member of closed loop form for defining a stoma aperture therein, the first member having a channel defined by two opposed walls with a tapering rib extending from the base of the channel and between its walls, and a second member of closed loop form also defining a stoma aperture, the second member having a projection dimensioned and positioned to fit with and resiliently bear against at least one of the walls when the members are connected in such a way as to make sealing engagement with at least one of the walls, wherein the second member has a tapering groove in that surface of the projection which faces towards the first member in the mutually coupled condition of the first and second members, said groove being of complementary shape to the rib; the rib and the complementary groove respectively having surfaces tapering at from 12 to 18 degrees to the rotation axis of the coupling, and wherein the second member has a deflectible sealing strip integral with and extending from the periphery of the projection. In an embodiment of the invention, each coupling is of resilient synthetic plastics material. The first member may be secured to the bag and the second member may be secured to the pad or dressing. Alternatively, the first member may be secured to the pad or dressing and the second member to the bag. In a preferred embodiment of the invention, the aperture is substantially circular and the two opposed walls are substantially annular in form. 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:- Figure 1 is a cross-sectional view, taken on a radial plane intersecting the coupling axis, showing part of one example of an ostomy coupling according to the invention with the two coupling members in their mutually coupled condition; Figures 2, 3 and 4 are respectively cross-section, side view and front view of an example of first coupling member according to the invention; and Figures 5, 6 and 7 are respectively radial cross-section, front view, and side view of an example of second coupling member according to the invention. The illustrated ostomy coupling comprises a first member 10 and a second member 20 which, in use, both surround a stomal orifice 30. In the embodiment illustrated, the first member is the bag side member and the second member is the body side member but in an alternative embodiment these may be reversed. A bag 40 is shown secured, e.g. by heat welding, to the first member 10. The first member 10 is basically in the form of an annular channel having an inner wall 11, an outer wall 12, and a base 13. The ostomy bag 40 is attached in any convenient way to the surface 13A of the base 13. It has been found that when a bag is heat or RF welded as indicated at 42 to the annular channel member 10, the plastics of the member 10 may become affected by the application of energy in that area, resulting in a tendency for the member 10 to be more readily deformed. Hence a tilting of the radially outer portion of the member 10 becomes more likely. On the opposite side of the base from the surface 13A, there is provided a rib 14 which has tapering surfaces 14A and 14B joined by rounded surface. The depth of the channel is defined herein as the distance d. The rib 14 extends from the base 13 a distance approximately equal to half the depth d. The height of the groove complementary to the rib 14, and the rib height, are preferably substantially equal to between 40 and 60 percent of the depth "d" of the channel defined by first member 10. The wall 14B of the rib merges into a curved wall 13B which forms the base of recess 13C. A rim 12A extends radially inwardly a short distance, from the free end of the wall 12. This rim is conventional and forms no part of the novelty of the invention. The first coupling member 13 has thereon a grasping tab 13E which may be used to separate the two coupling members when the wearer wishes to manually pull them apart. It also has two ears 13F and 13G which are used if the wearer desires to have the extra security of a belt in which event the ends of the belt would be attached suitably to the respective ears. Referring now to Figures 5-7, the second member 20 comprises an annular wall 21 made integral with an annular flange 22. A medical grade adhesive pad, not shown, is attached in any suitable way to the surface 22A of the flange 22. The wall 21 and the flange 22 are preferably made integral with each other and the whole member may be moulded from synthetic plastics material. An annular flexible and deflectible sealing strip 23 is integral with and extends from the periphery of the wall 21, in the manner shown. This strip is provided to obtain good sealing between the coupling parts. In this connection, the attention of the reader is drawn to U.K. Patent No. 1 568 860. Also extending from an end of the wall 21, is an annular rib 24 having tapering surfaces 24A and 24B joined by a rounded surface 24D. The surface 24B terminates in a peripheral rim 24C which stands slightly proud of the external surface 21A of the wall 21. The purpose of the described formations can best be understood by referring to Figure 1, from which it is seen that the rim 24C co-operates with the rim 12A to hold the two parts together and the seal strip 23 bears against the outer wall 11A of the wall 11. The rib 14 and complementary groove 20A in the second member 20 respectively have surfaces tapering at from 12 to 18 degrees to the axis (i.e. the central axis of rotation) of the ostomy coupling. As shown in Figure 1, the strip 23 is seen dotted in its undeformed position to illustrate the relative dimensions of the parts in the unstressed condition. An ostomy bag 40 is shown attached to the member 10, e.g. by adhesive or by plastics welding. As shown in Figure 1, the two coupling members are seen slightly separated. In normal use, they will be substantially in contact with one another. The inter-engagement between the rib 24 and the recess 13C, together with the inter-engagement between the seal strip 23 and the recess 13D (Figure 2) gives rise to a very secure inter-engagement which is highly resistant to and effectively prevents tilting of one coupling member relative to the other. This prevention of deformation of the member 10 is achieved even in cases where the application of energy in the region 42 has been such that substantial deformation of the member 10 would have been unavoidable in prior art couplings. This advantage of secure inter-engagement is obtained without any increase in the expense or difficulty of manufacture of the parts, and leaves unaffected all the advantageous features of an ostomy coupling of this general type. Modifications may be made without departing from the invention. For example, as already indicated, the member 10 may be the bag side member and the member 20 may be the body side member. Different specific shapes may be employed for the flexible seal strip 23 and the rib 24. While it is advantageous to have the rounded formation 24D and the peak of the rib 14 rounded, this is not essential and the tapered walls may join at a sharp apex (as seen in cross-section) if desired. Of course the attachment ears 13F and 13G may be dispensed with if desired. Other specific shapes may be employed for the rim 12A. It will be seen that the particular embodiment disclosed and illustrated herein provides an effective and inexpensive manner of overcoming the problem of undesired tilt in two-part ostomy couplings.

Claims: A coupling for joining a pad or dressing to an ostomy bag including a first member (10) of closed loop form for defining a stoma aperture (30) therein, the first member having a channel defined by two opposed walls (11,12) with a tapering rib (14) extending from the base of the channel and between its walls (11,12), and a second member (20) of closed loop form also defining a stoma aperture, the second member having a projection (21) dimensioned and positioned to fit with and resiliently bear against at least one of the walls (11,12) when the members (10,20) are connected in such a way as to make sealing engagement with at least one of the walls (11,12), wherein the second member has a tapering groove (20A) in that surface of the projection (21) which faces towards the first member in the mutually coupled condition of the first and second members, said groove (20A) being of complementary shape to the rib (14); the rib (14) and the complementary groove (20A) respectively having surfaces tapering at from 12 to 18 degrees to the rotation axis of the coupling, and wherein the second member (20) has a deflectible sealing strip (23) integral with and extending from the periphery of the projection (21). A coupling according to claim 1 in which each coupling member (10,20) is of resilient synthetic plastics material. A coupling according to claim 1 or 2 in which the first member is secured to the bag and the second member is secured to the pad or dressing. A coupling according to claim 1 or 2 in which the first member is secured to the pad or dressing and the second member is secured to the bag. A coupling according to any preceding claim in which the aperture (30) is generally circular and the two opposed walls (11,12) are generally annular in form. A coupling according to any preceding claim in which the rib (14) and the groove (20A) complementary thereto each have a rounded surface at their apices. A coupling according to any preceding claim in which the radially outer wall (12) of the first member (10) has a rim (12A) thereon for cooperation with a rim (24C) on the second member (20).

Inventors: STEER PETER LESLIE, STEER, PETER LESLIE
Applicants: SQUIBB & SONS INC, E.R. SQUIBB & SONS, INC.
Application year: 1992
Main classification: A61F5
IPC codes: A61F5