Abstract:
An adhesive ostomy coupling comprises first and second coupling parts each having a respective orifice. The first coupling part includes an upstanding wall for entering the orifice of the second coupling part. The second coupling part includes an adhesive faceplate for adhering to the first coupling part outside the upstanding wall. The upstanding wall and the faceplate form an interference fit at a position corresponding to the inner periphery of the adhesive, to protect the adhesive from effluent attack. The upstanding wall has an undercut for interlocking with the adhesive faceplate of the second coupling part. The upstanding wall also acts as a guide to prevent mispositioning of the pouch when mounting the adhesive faceplate on the complementary flange.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to an adhesive ostomy coupling, for example, for adhesively attaching an ostomy pouch or other appliance to a body fitment worn on the body. 
       BACKGROUND TO THE INVENTION 
       [0002]    U.S. Pat. No. 5,800,415 describes an adhesive ostomy coupling for attaching a pouch to a body fitment. The pouch includes an annular adhesive faceplate for adhering to a complementary annular flange on the body fitment. The flange on the body fitment includes an upstanding collar projecting from the inner rim towards the pouch. The collar is said to act as a guide to prevent mispositioning of the pouch when mounting the adhesive faceplate on the complementary flange. Once attached, the collar is also said to form a passage for the stoma, to protect to some extent the adhesive faceplate from feces flowing out from the intestine. 
         [0003]    It would be desirable to enhance the properties of an adhesive coupling. 
       SUMMARY OF THE INVENTION 
       [0004]    In one aspect, the present invention provides an adhesive ostomy coupling comprising complementary first and second coupling parts, each having a respective orifice. At least one of the coupling parts carries an adhesive for adhering to the other. 
         [0005]    The invention may further comprise one or more of the following features: 
         [0006]    (a) The coupling parts are configured to form an interference fit at a position corresponding to, or inboard of, the inner periphery of the adhesive. 
         [0007]    The term “inboard” is used herein to mean closer to the axis of the coupling and/or the axis of the respective orifice. 
         [0008]    The interference fit may exist in the finally assembled condition of the coupling, or the interference fit may occur in an intermediate position of the coupling members during assembly and/or separation. 
         [0009]    In one form, the interference fit is provided by an interlocking engagement between the coupling parts. For example, a portion of one coupling part is configured to locate in a trough behind a shoulder portion of the other coupling part. 
         [0010]    The existence of an interference fit can enhance the protection of the adhesive, particularly the inner peripheral edge, from contact by effluent discharged from the stoma, whether the effluent is solid, or semi-solid/semi-liquid, or liquid. Typically, the adhesive used for adhering the coupling parts together may be vulnerable to attack by effluent, leading to loss of adhesion and reduced operating life of the coupling. 
         [0011]    Preferably, the interference fit also acts as a guide for aligning the two coupling parts during assembly of the adhesive coupling. 
         [0012]    Preferably, the interference fit provides a positive seal between the coupling parts in the assembled condition of the coupling parts, to more comprehensively protect the adhesive from contact by effluent. 
         [0013]    The provision of an interference fit and/or seal may be particularly more effective than the simple upstanding collar used in the abovementioned U.S. Pat. No. 5,800,415. In that patent, the collar is not said to make any contact or seal with respect to the adhesive faceplate. Instead, the collar merely acts as an open ended inner passage passing untouched through the exposed inner edge of the adhesive faceplate. When effluent reaches the end of the passage, the effluent is free to pass in any direction, and thus is still free to contact the exposed edge of the adhesive. For example, if the pouch is worn under tight clothing, or the wearer is seated, reclined, or lying asleep, the effluent may be especially liable to flow in a direction into contact with the adhesive. 
         [0014]    (b) One of the coupling parts comprises an upstanding wall or bead for fitting inside the orifice of the other coupling part. The upstanding wall is configured to have an undercut profile on its (radially) outwardly facing surface. The profile may have relatively well defined corners and faces, for example, to define an annular recess that is generally rectangular in section, or the profile may be more rounded, for example, circular to define a trough near the base. 
         [0015]    The undercut provides positive interlocking engagement with the inner edge of the orifice of the second coupling part. Such interlocking engagement can provide a more effective obstacle to hinder effluent from coming into contact with the adhesive. 
         [0016]    The material of the second coupling part defining the periphery of the orifice may be at least partly compliant, for example, resiliently compliant. The material may, for example, comprise a foam material. 
         [0017]    Additionally or alternatively, the projecting height of the upstanding wall may be greater than the thickness of the material of the second coupling part in the region that bounds the orifice of the second coupling part. This can increase the security of the interlocking engagement. 
         [0018]    Additionally or alternatively, the upstanding may be at least partly compliant, for example, resiliently compliant. The upstanding wall may, for example, be made of foam. In another form, the upstanding wall is thermoformed from a sheet of plastics film. 
         [0019]    (c) One of the coupling parts comprises an upstanding wall, the wall being made of plastics film and the wall having a hollow interior. The wall may be produced by thermoforming. 
         [0020]    The wall may have a self-supporting shape, yet be flexible or compliant. 
         [0021]    The wall may have an undercut outer profile. 
         [0022]    Although the above aspects have been described independently, additional advantages may be obtained by combining any of the above aspects together. All combinations are explicitly envisaged. While features believed to be of importance are summarized above and in the appended claims, the Applicant claims protection for any novel idea or feature described herein and/or illustrated in the drawings whether or not emphasis has been placed thereon. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a schematic front perspective view of an ostomy body fitment of a first embodiment. 
           [0024]      FIG. 2  is a schematic sectional view showing the body fitment of  FIG. 1  and an ostomy pouch for attachment to the body fitment. 
           [0025]      FIG. 3  is an enlarged view of a detail of  FIG. 2 . 
           [0026]      FIG. 4  is a schematic sectional view similar to  FIG. 3 , but showing the pouch engaged with the body fitment. 
           [0027]      FIG. 5  is a schematic sectional view similar to  FIG. 4 , but showing an alternative interlocking form. 
           [0028]      FIG. 6  is a schematic sectional view similar to  FIG. 4 , but showing a further alternative interlocking form. 
           [0029]      FIG. 7  is a schematic sectional view similar to  FIG. 4 , but showing a further alternative interlocking form. 
           [0030]      FIG. 8  is a schematic sectional view similar to  FIG. 3 , but showing an alternative profile of bead. 
           [0031]      FIG. 9  is a schematic sectional view through a body fitment of a second embodiment. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0032]    Embodiments of the present invention will now be described referring to the drawings by reference numerals where like numerals refer to like parts. 
         [0033]    Referring to  FIGS. 1 to 7 , an ostomy coupling comprises a first coupling part  10  of a body fitment  12 , and a second coupling part  14  of an ostomy pouch  16 . 
         [0034]    The body fitment  12  generally comprises the first coupling part  10  secured to a pad or wafer  18  of a skin compatible adhesive. The adhesive optionally has a wafer orifice  20  for receiving a stoma, in use. The orifice  20  may be pre-sized to fit the user&#39;s stoma, or the wafer orifice  20  may be a starter hole which the user adjusts, either by cutting or molding the surrounding adhesive, to enlarge the hole to a desired size to fit the individual stoma. The rear, skin-contacting face  22  of the adhesive may initially be protected by a release sheet  24  ( FIG. 2 ) that the user removes prior to fitting the body fitment  12  to the peristomal skin. 
         [0035]    In the illustrated form, the front face (non-skin contacting face) of the wafer  18  has a non-adhesive skin of plastics film or non-woven material  26 , and the first coupling part  10  is secured to the film or non-woven material  26 , for example, by welding or by adhesive. In an alternative form, the first coupling part  10  may contact, and be secured by the adhesive of the wafer  18 , such that the first coupling part  10  also acts as the non-adhesive skin of the wafer  18 . 
         [0036]    The first coupling part  10  generally comprises a planar flange  28  from which projects an upstanding wall in the form of a bead  30 . The bead  30  projects frontwardly (i.e., away from the skin contacting face of the wafer  18 , and towards a pouch  16 , in use). The bead  30  is integral with the flange  28 . The first coupling part  10  comprises an orifice  32  in register with and/or substantially surrounding the wafer orifice  20 . In the illustrated embodiment, the orifice  32  is larger than the wafer orifice  20 . Such an embodiment is especially suitable when the adhesive around the wafer orifice  20  is intended to be moldable to enable the user to enlarge the wafer orifice  20  by manually molding or manipulating the adhesive. The larger orifice  32  does not obstruct such molding within the boundary of the orifice  32 . In an alternative form, the orifice  32  may be substantially the same size as the wafer orifice  20 , for example. Such an arrangement may be suitable for a wafer  18  that has a pre-sized wafer orifice  20  or is intended to be cut to size. 
         [0037]    Referring especially to  FIG. 3 , in the illustrated form, the first coupling part  10  is made of a stiff, but flexible, plastics film or sheet, composed of such materials as polyolefin homopolymers and copolymers, including polyethylene, ethylene vinyl acetate (EVA) copolymers, polypropylene, and/or polybutylene. The sheet is thermoformed to define the shape of the bead  30  projecting integrally from the flange  28 . The bead  30  is hollow, the surfaces of the upstanding wall of the bead  30  being made of the thermoformed film. Thermoforming gives the upstanding wall of the bead  30  as self-supporting shape, but the upstanding wall of the bead  30  is also soft and compliant. Thermoforming also enables the wall  30  to be made from film material, especially the same film that forms the flange  28 . In other forms, the tubular upstanding wall of the bead  30  could be of a different non-hollow construction, such as an annular piece of foam permanently attached to the flange  28 . 
         [0038]    Also, as can be seen in  FIG. 3 , the profile of the radially outer surface of the bead  30  is undercut. The profile comprises an annular recess or trough  34  behind an annular shoulder  36 . In the illustrated form, the bead  30  profile has generally well defined corners. Other profiles including an undercut may be used as desired, for example, the rounded bead  30  profile illustrated in  FIG. 8 . The rounded bead  30  profile provides a trough  34  located behind a shoulder  36 . 
         [0039]    Referring again to  FIGS. 1-7 , the second coupling part  14  generally comprises an annular faceplate  40  carrying a layer of adhesive  42 , and surrounding an orifice  44 . The faceplate  40  is flexible, but of generally self-supporting shape. In the illustrated form, the faceplate  40  is of foam, such as closed-cell foam to prevent migration of effluent through the foam that could otherwise attack the adhesive  42 . The adhesive  42  may be any suitable peelable adhesive suitable for adhesive ostomy couplings, such as an acrylic pressure-sensitive adhesive. Prior to first use of the pouch  16 , the adhesive  42  may be protected by a release sheet  46  carrying adhesive repellent material, such as silicone. The release sheet  46  may be removable in one piece, or it may be divided into two or more segments that are removable one after the other. 
         [0040]    As illustrated by the different forms in  FIGS. 4 to 7 , the first and second coupling parts  10 ,  14  are dimensioned to form an interference fit at least during assembly and/or separation of the coupling parts  10 ,  14 , and preferably in the assembled condition. In particular, the diameter of the second coupling part orifice  44  is smaller, at least slightly, than the outer diameter of the annular shoulder  36  of the bead  30 . When the coupling parts  10 ,  14  are assembled, the inner peripheral edge of the faceplate  40  bears against the annular shoulder  36 , forming at least a first step of interference fit. The annular shoulder  36  deforms inwardly and/or the faceplate  40  deforms outwardly, to allow the two to pass. The axial projecting height of the bead  30  is greater than the thickness of the second coupling part  14  in the region surrounding the second coupling part orifice  44 . In the assembled condition (illustrated in  FIGS. 4 to 7  described later), the faceplate  40  locates in the trough  34  behind the annular shoulder  36 , and the adhesive  42  contacts the flange  28  in order to hold the coupling parts  10 ,  14  assembled together. One function of the bead  30  is to aid alignment of the two coupling members  10 ,  14  such that the respective orifices  32 ,  44  are substantially in register, and the adhesive  42  is in register with the flange  28  that acts as a contact landing zone for the adhesive  42 . However, as illustrated below, the undercut shape of the bead  30 , and the relationship between the bead  30  and the faceplate  40  provides other important effects to protect the inner peripheral edge of the adhesive  42  from contact with effluent discharged from the stoma. 
         [0041]    In one possible form illustrated in  FIG. 4 , the diameter of the second coupling part orifice  44  is smaller, at least slightly, than the outer diameter of the trough  34 , thus creating a second step of interference fit in the assembled condition of the coupling parts  10 ,  14 . Moreover, the axial thickness of the second coupling part  14  (i.e., the combined thickness of the faceplate  40  and the adhesive  42 ) is dimensioned so as to substantially fill the axial height of the trough  34 , thus forming a third step of interference fit. This configuration provides an optimum seal of the inner peripheral edge of the faceplate  40  and the adhesive  42 . The interference fits are aided by the pliability of the bead  30  and/or the faceplate  40 . 
         [0042]    In another possible form, illustrated in  FIG. 5 , the diameter of the second coupling part orifice  44  is the same as in  FIG. 4 , but the axial thickness of the second coupling part  14  is smaller than the axial height of the trough  34 . In the assembled condition, a clearance  48  may exist between the annular shoulder  36  and the faceplate  40 . Nevertheless, the inner peripheral edge of the adhesive  42  is still protected comprehensively by the interference fit seal in the trough  34 . 
         [0043]    In another possible form, illustrated in  FIG. 6 , the axial thickness of the second coupling part  14  is the same as in  FIG. 4 , but the diameter of the second coupling part orifice  44  is larger than that of the trough  34 , thus leaving a radial clearance  50  in the trough  34 . Nevertheless, the inner peripheral edge of the adhesive  42  is still protected comprehensively by the second coupling member  14  filling axial height of the trough  34 . 
         [0044]    In another possible form, illustrated in  FIG. 7 , the axial thickness of the second coupling part  14  is smaller than the axial height of the trough  34 , and the diameter of the second coupling part orifice  44  is larger than that of the trough  34 , thus leaving both an axial clearance  48  and a radial clearance  50 . In this form, the inner peripheral edge of the adhesive  42  is still protected to a practical degree by the presence of the annular shoulder  36 , which acts as a fence in front of the exposed edge of the adhesive  42 . In order to reach the exposed edge of the adhesive  42 , effluent would have to negotiate a relatively tortuous path around the profile of the annular shoulder  36 . 
         [0045]    In the above described embodiment, the flange  28  acts as a landing zone for the adhesive  42 . However, if desired, the flange  28  may be omitted, and the adhesive  42  may instead contact the filn or non-woven material  26  of the body fitment  12 . 
         [0046]    Alternatively, as illustrated in the further embodiment of  FIG. 9 , the flange  28  may partly “float” with respect to the wafer  18 . The flange  28  may be joined to the wafer  18  at a point  60  inboard of the outer periphery  62  of the flange  28 , the outer periphery  62  being substantially unattached to the wafer  18 . 
         [0047]    In the above embodiments, the adhesive  42  is carried on the second coupling part  14 . The adhesive  42  may instead be carried on the first coupling part  10  (e.g., on the flange  28 ). The adhesive  42  may also be carried on both coupling parts  10 ,  14 , if desired. 
         [0048]    In the above embodiments, the orifices  20 ,  44  in the coupling parts  10 ,  14  are generally round. However, any closed-loop shape may be used as appropriate for an intended ostomy application. 
         [0049]    The foregoing description is illustrative of preferred forms of the invention. Many modifications, improvements and equivalents are possible without departing from the coverage of the invention.