AU592885B2 - Ostomy appliance coupling with viscoelastic liner - Google Patents

Description

Australia PATENTS ACT 1952 592885 Form COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: Frority: 'rlis doeunmorit ofisth 1J~iflh'~S rddC Infd, I :..xtioll 49 and is correct fuil Related Art: Nbme of Applicant: Address of Applicant: Actual Inventor: Address for Service: TO BE COMPLETED BY APPLICANT HOLLISTER INCORPORATED 2000 Hollister Drive, Libertyville, Illinois 60048, U.S.A.

PAUL 0. KAY CALLINAN AND ASSOCIATES, Patent Attorneys, of 48-50 Bridge Road, Richimond, State of Victoria, Australia.

Complete Specification for the invention entiked: "OSTOMY APPLIANCE COUPLING WITH VISCOELASTIC LINER".

The following statement is a full description of this invention, including the best method of performi ng it known to Note: The description Is to be typed in double spacing, pica type face, in an area not ex~ceeding 250 mnm in depth and 160 mm in width, on tough white paper of good quality and it is to be inserted inside this form.

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The present invention relaten, in general terms, to an improved form of couplingj for an outomy appliance, and tQ an ootomy appliance inoluding ouch a couling. U.S, Patent No. 41610#676 diclonoo an ostomy appliance coupling ring construction composeOd of a pair of relatively flat rings formed of polyethylene or other relatively soft, flexible plastics material. one of the rings has a tubular neck portion of limited axial ao extent terminating in an annular rim, the configuration defining a generally outwardly-facing channel that receives the annular collar or flange of the other ring when the two are coupled together. Contact betwoen the two rings within the channel is responsible for producing an effective liquid-tight seal betwoeen the parts, and that seal is maintained despite the flexing and bending to which the rings are subjected in use because of a second zone of contact, well outboard from the sealing zone, that performs a primary latching function.

ZO The basic purpose of the coupling ring assembly of the aforementioned Patent, and of all other recent coupling ring assemblies for ostomy appliances, is to facilitate replacement of an ostomy pouch while at the same time permitting the adhesive faceplate to remain in position on the wearer's body. Thus, over a period of days, a number of pouches will be coupled to and uncoupled from a single faceplate coupling ring. Each time such coupling/uncoupling actions occur, there is a risk that the sealing surfaces of the rings might become scratched 999.4 9 99 41 9 4 -2 1 -409 (as by a fingernail), ni,.ed, or otherwise damaged.

Any such damage, even a scratch too small to be readily observed by the naked cye, may be enough to provide a leakage pathway when the rings are joined together. The problem is compounded by the fact that such appliances are frequently worn by elderly or infirm patients who lack the minimal dexterity needed for easily coupling and uncoupling the rings and who may have difficulty manipulating such rings without damaging their sealing surfaces.

An important aspect of the present invention lies in the discovery that problems of leakage may be virtually eliminated, and other significant V 0* "410 benef its may be obtained, if a viscoelastic polymeric g0 liner is secured within the radially-facing channel of one of the rings. Particularly advantageous results are achieved if the viscoelastic liner, in addition to being 0 *0 deformable, also has controlled pressure-sensitive 00 adhesive properties. Whether adhesive or not, the elastomeric liner deforms in response to unequal forces exerted M by the flange of the other coupling ring when it is '4 seated within the channel. Any voids between the two rings that might otherwise result in leakage or fluid bypass are effectively eliminated. The viscoelastic liner is also able to adjust itself to slight dimensional variations that may exist between successive pouch rings, thereby giving the user assurance that a single faceplate ring may be successively coupled to a multiplicity of pouch rings without risks of leakage.

-3 I 100500_ Where the viscoelantic liner alu;o hao adhesive properties, it augmentG the necurity of attachment between the two rings an well an enourinq against leakage. It in essential that the bond between the liner and the channel in which it is retained be greater than the adhesive attraction between the liner and the flange of the other ring so that, when the other ring is removed, the liner will remain within the channel. This may be achieved by forming the liner o a hot melt ac' ,sivo and then flowing that adhesive in a molten state into the channel where it solidifies or cures. Adherence between the liner and the flange of Ooo, the other ring may also be controlled by selecting an o' .9 ,appropriate formulation or surface treatment for that 15 ring so that its surface has less at£inity for the 99 99 ltt adhesive than that of the channel-providing ring.

Where the liner also has adhesive properties, fir it contributes in providing a coupling ring assembly that requires greater force to disassemble than to assemble.

A user finds the rings may be easily slipped together 4 into coupled relation. The substantially greater force required to separate them provides security against possibilities of unintentional separation of the parts.

In accordance with the present invention, therefore, there is provided a coupling for an ostomy appliance including: a first ring formed of flexible plastics material defining an axially-extending opening therethrough for receiving a patient's stoma, said first 4 ring also having a generally radially-f acing annular channel for receiving and detachably engaging an annular flange of a second coupling ring adapted to mate with said first ring; and a deformable liner of viscoelastic polymeric material securely and sealingly bonded to said first ring within said channel for making direct, shape-conforming, fluid-tight sealing contact with said flange when said first and second rings are coupled together, wherein said viscoelastic material is a hot-melt sealant.

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ring also having a generally radially-facing annular channel for receiving and detachably engaging a annular flange of a second coupling ring apted to mate with said first ring; and a defor e liner of viscoelastic polymeric mate 'a securely and sealingly bonded to said first ng within said channel for making direct, shape- nforming, fluid-tight sealing contact with s flange when said first and second rings are upled together.

**fiu* In accordance with the invention there is also provided an ostomy appliance including a coupling S' of the type referred to in the preceding paragraph.

In order that the invention may be more clearly understood and put into practical effect there shall now be described in detail a preferred construction of a coupling for an ostomy appliance in accordance with 4 the invention. The description is given by way of nont limitative example only and is with reference to the accompanying drawings, wherein: Figure 1 is a perspective view of an ostomy appliance equipped with a coupling ring assembly of this invention, the ostomy bag and faceplate being shown in separated condition for clarity of illustration; Figure 2 is a somewhat enlarged schematic fragmentary sectional view showing the relationship of parts when the rings are coupled together;

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Figure 3 is a still further enlarged schematic fragmentary sectional view of the faceplate ring with its viscoelastic sealant liner; Figure 4 is an enlarged sectional view similar to Figure 3 but showing deformation of the liner when the flange of a pouch ring is received within the channel; and Figure 5 is a fragmentary sectional view depicting the viscous flow or change in liner configuration as the forces exerted by the coupling ring flange are rernoved.

Referring to the drawings, the numeral 0 0 1 generally designates an ostorny appliance having a faceplate 11 and a bag or pouch 12. A two-piece coupling ring assembly 13 is provided for detachably coupling the faceplate and pouch, one element of the assembly being

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faceplate ring 13a and the other being pouch ring 13b.

Both the pouch and the faceplate may vary considerably in size, shape, and construction, all as well known in the art, and it is to be understood that coupling assembly 13 is not limited in its use to the 4* particular pouch and faceplate constructions depicted in "4 the drawings. For example, pouch'12 is shown to have an outlet 14 at its lower end, such outlet being intended to be closed by a suitable clamping device (not shown) such as the one disclosed in U.S. Patent No. 3,523,534.

However, the pouch may if desired be "non-drainable", in which case outLlet 14 would be omitted. Typically, pouch 6- 12 is designed to be relatively flat and is composed of two sheets or walls 12a and 12b of flexible thermoplastic film that are heat scaled together along their outer margins as indicated at 15 in Figure 1.

Faceplate 11, in the particular form illustrated in the drawings, is constructed generally in accordance with the teachings of U.S. Patent No. 4,213,458 and reference may be had to that Patent for information on the details of construction.

.1a Faceplate 11 includes a highly flexible patch or panel 4 0o 17 formed of gas-penetrable but water resistant microporous material. Various materials having such properties are known and may be used. In any case, the faceplate should be highly flexible so that it will conform readily to body contours and body movements, and be coated on its back or rear side with a medical-grade 4 *pressure-sensitive adhesive so that upon removal of ,backing sheet or sheets 18 the microporous adhesivecoated patch or panel 17 may be secured to the patient's skin in the peristomal region.

4. An attaching ring or collar 19 may be secured to the front face c" the microporous patch 17 by heat sealing or by any other suitable means. The attaching ring must also be capable of being heat sealed or otherwise securely joined, either directly or indirectly, to ring 13a of the coupling ring assembly 13. In the construction depicted in the drawings, such connection is 7y -IO J .a~ indirect to the extent that a web 23 of thin, £3oxible, and resilient thermoplastic material is interposed between faceplate ring 13a and the attaching ring 19 of faceplate 11, as genarally disclosed in U.S. Patent No. 4,419,100.

Specifically, the inner margin of the annular web 23 is heat sealed at 20 to the faceplate 11 and its outer margin is heat sealed at 24 to faceplate ring 13a. The web gives rise to a floating relationship between the faceplate ring 13a and faceplate 11, promoting conformity of the faceplate to a wearer's body without resistance from the S* coupling rings and, in general, allowing limited movement 09 09 0 a of the faceplate ring in generally axial directions with o*o0 respect to the faceplate. Such limited movement allows a a* o user to insert his (her) fingers between the ring 13a and faceplate 11 to facilitate attachment and detachment of the coupling rings without causing discomfort. The web S0 4 Sshould be formed of a heat sealable, tough, and durable material that is also capable of functioning as a fluid and odor barrier. Low density polyethylene coextruded with a coextensive layer or core of polyvinylidene 9 9 chloride, known under the designation Saranex, from Dow Chemical Company, Midland, Michigan, has been found suitable but other materials having similar properties are available and may be used.

The coupling rinig assembly, and particularly the structural relationship between faceplate ring 13a and pouch ring 13b, is illustrated most clearly 8 in Figures 2 and 4. Ring 13a has an annular body portion 25 and an integral tubular neck portion 26.

At its outer limits, the planar body portion 25 provides an annular latching shoulder 27 that is shown to be continuous althougn, if desired, the latching shoulder may be discontinuous or interrupted along its circumference.

The neck portion 26 of ring 13a tapers axially and forwardly away from planar body portion 25 and, '100 at its front or distal end, has an annular and radially- 9,, Lo, outwardly projecting rim 28. The rim, neck portion, and body portion together define a radially-facing annular channel 26a. Within that radially outwardly-facing channel is a liner or layer 29 of viscoelastic polymeric sealant material.

The liner 29 is readily deformable and, in an undisturbed state, assumes the condition shown in Figure 3 of the drawings. In that state, it provides a substantially uniform coating or layer along the base of 0 channel 26a. Since the liner is securely bonded to the neck portion 26 of the coupling ring 13a, it is not free to be displaced from the channel. However, the configuration it assumes within the channel may be substantially altered, as indicated in Figures 2 and 4.

The viscoelastic liner may be formed of any of a variety of materials having a combination of properties, in varying degrees, of deformability, 9 I L recoverability, tackiness, and flow. Low durometer thermoplastic elastomers such as silicone rubber, polyurethano, or polybutene/polyisoprene may be used and may be applied by coating from a dispersion or solvpnt system, by mechanical transfer, or by any other sui+.ble technique. Ideally, the viscoelastic liner is formed in place by flowing it into the channel in molten state. For that purpose, the melting temperature of the sealant liner material should not so far exceed I# the melting temperature of the thermoplastic material from which ring 13a is formed that the ring becomes Sdeformed or damaged as the molten liner material solidifies, it being understood that a slight momentary softening of the surface of the ring by the molten sealant may be beneficial in producing an even more secure bond between the ring and the sealant liner. In view of the manner of its application, the liner material may be referred to generally as a "hot-melt sealant".

Such hot melt sealants are well known and are ordinarily composed of thermoplastic elastomers blended with polyethylene or ethylene copolymers and, in many cases, tackifiers such as terpenoids or polyisobutylene.

Particularly effective results have been achieved where the viscoelastic sealant, in addition to being thermoplastic, deformable, and elastically recoverable, also has pressure-sensitive adhesive 10 111 9 i P C characteristics. Again, hot melt adhesives having such properties are known and any of a number of them may be used for this purpose. For example, one such material is available under the designation HM6515 from H. B. Fuller Company, St. Paul, Minnesota.

Others are designated as 34-2881 from National Starch Chemical Corporation, Bridgewater, New Jersey, and 84116 from Swift Adhesives Division, Reichhold Chemicals, Inc., Chicago, Illinois. While such adhesive properties may contribute in promoting a more effective seal *oo between the coupling rings (a function that is believed *oo* to be achieved largely by the sealant's deformability), ao oo theyclearly result in a more secure connection between a the parts. The hot melt materialis applied in a molten state by flowing it into channel 26a to form a liner *00 having a thickness within the range of approximately °s 0.01 to 0.05 of an inch.

The pouch coupling ring 13b is provided with a body portion 30 that extends in a plane normal to the 2R central axis of that ring. A generally frusto-conical collar portion or flange 31 tapers axially from the inner margin of the body portion 30, the general direction of taper of the flange being the same as that of the neck portion 26. The inner surface of the flange is provided with an annular projection 31a, such projection defining the smallest inside diameter of the flange for sealingly engaging the liner 29 along the outer surface 26 of ring 11 l3b. At its distal or freo end, the flange is provided with an axially-facing annular ridge 31b that normally abuts rim 28 when the parts are assembled as shown in Figures 2 and 4.

Along its outer perimotor, body portion merges with an annular latching rib 32 which projects inwardly and axially in a direction opposite from that of flange 31 and which, along with the remainder of body portion 30, defines an outwardly and rearwardly facing recess 33 for detachably receiving and retaining So,' the shoulder 27 of faceplate ring 13a. The rib 32 may be provided with rounded surfaces, as shown in Figure 2, to facilitate latching engagement and disengagement oC the two rings.

Excluding deformable sealant liner 29, coupling rings 13a and 13b are similar to those described in U.S. Patent No. 4,610,676 and reference may be had to such Patent for further details concerning the features, functions, and advantages of such ring ,,2f construction. While rings 13a and 13b are believed to Srepresent a particularly effective coupling ring arrangement for utilizing sealant liner 29, it is believed that numerous modifications and variations in ring structure might be made. Thus, especially where liner 29 has pressure-sensitive adhesive porperties, it may be possible to omit entirely the rib 32 and its outboard 12 latching function. Alternatively, the radially inwardly-facing surfaces defining recess 33 may also be lined with viscoelastic sealant material to convert the outer latching zone into a latching/sealing zone.

The important characteristic of the sealant liner 29 is graphically depicted in Figures 3-5. In an undisturbed state, the viscoelastic liner is generally of uniform thickness (Figure 3) but it is readily deformed by forceful contact by flange 31 and particularly by its projection 31a (Figure By reason of such forceful contact, the viscoelastic material flows or is displaced circumferentially, radially, and axially to insure that no voids or gaps exist between the liner 29 and flange 31. The sealant liner or layer 29 and the rings 13a and 13b are so proportioned that some displacement of the liner must take place when the parts are fitted together.

Upon separation of the parts, the memory characteristics of the viscoelastic material cause it to return at least partially in the direction of arrows 35 to its original undisturbed state (Figure Consequently, pouch rings 13b may be repeatedly coupled to and uncoupled from faceplate ring 13 with the viscoelastic liner being capable at each occasion of yieldably engaging the pouch ring and forming a fluid-tight seal therewith.

Where the liner has pressure-sensitive adhesive properties, rings 13a and 13b may be made even more flexible to conform with changes in body contour 13 without risk that detachment of the rings might unintentionally occur. Thus, the resilient and flexible coupling rings, which may be formed of low-density polyethylene, may be made of flatter profile so that they do not protrude as far from the surface of the patient's body. Not only does such a construction make the product less noticeable, but the lower profile also allows the rings to conform more readily with changes demanded by body movements, thereby producing S' 10' greater comfort for the patient and reducing the I possibilities that the adhesive faceplate might pull away from the skin.

The uso of a hot-melt sealant liner that also has pressure-sensitive adhesive properties may be i 15 valuable in achieving a more secure fluid-tight connection between other types of medical couplings, such as intravenous set couplings, where the forces required for separation of the parts should substantially exceed those required for their assembly and where it is imperative that fluid-tight (liquid and gas) connections I ;be achieved.

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Claims (4)

1. A coupling for an ostomy appliance including: a first ring formed of flexible plastics material defining an axially-extending opening there-through for receiving a patient's stoma, said first ring also having a generally radially-facing annular flange for a second coupling ring adapted to mate with said first ring; and a deformable liner of viscoelastic polymeric material securely and sealingly bonded to said first ring within said channel for making direct, shape-conform- ing, fluid-tight sealing contact with said flange when said first and second rings are coupled together, wherein said viscoelastic material is a hot-melt sealant.

2. The coupling as claimed in Claim 1, in which said sealant has pressure-sensitive adhesive properties.

3. The coupling as claimed in Claim 2, in which the strength of a bond between said sealant and said first ring exceeds the strength of adhesion of said sealant to said second ring.

4. The coupling as claimed in any one of Claims 1 to 3, in which said Ia annular channel faces generally radially outwardly. Ir (1 -i F The coupling as claimed in any one of Claims 1 to in which an adhesive faceplate is secured to said first ring for adhesive attachment of said first ring and faceplate to a patient's skin about a stoma. i. The coupling as claimed in any one of Claims 1 to in which the thickness of said viscoelastic liner in an unstressed state falls within the range of from .010 to .050 inches. -1 4f. The coupling as claimed in any one of o**o the preceding Claims, in which said first ring is formed of low density polyethylene. s vwY---t- i'* The coupling as claimed in ClaimX, in which the strength of the bond between said hot-melt adhesive and said first ring exceeds the strength of adhesion of said hot-melt adhesive and said second ring. fc. The coupling as claimed in Claim 8, in which said hot-melt pressure-sensitive adhesive is applied to said first ring within said channel at a temperature sufficient to soften the surface of the first ring in contact with said adhesive and thereby securely bond said liner and first ring together. A coupling for an ostomy appliance, substantially as described herein with reference to the accompanying drawings. 16 INIPMM I I W. An ostomy appliance, including a coupling as claimed in any one of the preceding Claims. appliance in which one of the rings thereof -s aom generally radially-facing annular nnel for receiving and detachably q ging a latching flange of the other of the gs, said channel having a deformable liner of vi'coelastic polymeric material secured s~ D A TED this 31st day of July, 1987. HOLLISTER INCORPORATED By its Patent Attorneys: CALLINAN AND ASSOCIATES I I 17 A