GB2501405A

GB2501405A - Ostomy bag with spaced intermittent weld lines forming a non-return valve

Info

Publication number: GB2501405A
Application number: GB1309214.3A
Authority: GB
Inventors: Rory Smith
Original assignee: Welland Medical Ltd
Current assignee: Welland Medical Ltd
Priority date: 2013-05-22
Filing date: 2013-05-22
Publication date: 2013-10-23
Anticipated expiration: 2033-05-22
Also published as: GB2501405B; GB201309214D0

Abstract

An ostomy bag comprises a non-return valve formed from a welding pattern, comprising a first intermittent weld line having two or more curved welds, wherein the welds are curved concavely with respect to the flow direction, and a second intermittent weld line having two or more curved welds, wherein the welds are curved convexly with respect to the flow direction, and wherein the first intermittent weld line is spaced apart from the second intermittent weld line. The gap between the lines may be at least 10mm. Preferably, the curved welds are also horizontally offset so that each weld in one line is aligned with a gap between welds in the other line.

Description

Non-return valve arrangement for ostomy bags The present invention relates to an ostomy bag comprising a non-return valve having a specific weld lines and in particular to a urostomy bag comprising such a non-return valve.

Ostomy bags, such as urostomy, ileostomy and colostomy bags, for receiving bodily waste from urostomy, ileostomy and colostomy patients are well known. Such bags include an opening which allows bodily waste and/or fluid to enter the bag.

One problem with existing ostomy bags, in particular with urostomy bags, is that of reflux of fluid which has passed through the bag opening back up towards the opening, particularly when pressure is applied to the bag. In some cases, such fluid can leak out around the opening, where the bag attaches to the patient's skin, and there may also be skin soreness or irritation, and increased risk of infection.

Accordingly, certain known bags comprise a valve situated between upper and lower chambers of the bag, which allows inflow into the bag, but reduces reflux of fluid which has passed through the valve back into the upper chamber of the bag when pressure is applied. Such a valve is commonly referred to as a non-return valve (NRV).

A typical NRV is formed by intermittently welding two inner film layers of the bag. For example, WO 2013/038132 describes one such urostomy pouch formed from multiple layers, in which the innermost attachment wafer-side layer and the innermost non-attachment wafer-side layer are constructed to form a non-return valve by intermittently welding the lower edges of the two layers, so as to prevent reflux of fluid. In this case, a single intermittent weld line, i.e. a single broken weld line, is shown.

In other cases, an NRV may be formed by intermittently welding an inner film layer to a rear layer of the bag. For example, GB 2268882 describes one such urostomy pouch formed from a front wall, a rear wall, and an intervening wall, in which the intervening wall is welded via V-shaped bar welds to the rear wall to define a non-return valve.

However, there are certain disadvantages with the products that have been developed to date. In particular, testing of the currently available bags that include an NRV of various different weld patterns shows that a degree of reflux does occur for all such bags under the standard test conditions. This standard NRV reflux test comprises adding water to a urine collection bag, then subjecting it to a compressive load, and measuring the reflux through the NEW.

Certain other designs of urostomy bags have been developed to minimise the degree of reflux, such as that described in EP 0117016. However, bags such as described in this publication involve a non-return valve arrangement comprising a number of separate foil flaps folded in a specific manner so as to produce in effect a sequence of two non-return valves. Such an arrangement is more complicated in terms of manufacturing the bag and involves increased costs.

Therefore, there remains a need for an improved non-return valve arrangement for an ostomy bag that provides an acceptable flow rate, rninimises the degree of refiux, and is simple and cost-effective to manufacture.

The present invention sets out to provide an ostomy bag with an improved NRV that overcomes or at least alleviates the problems described above.

In accordance with the present invention, there is provided an ostomy bag comprising a non-return valve having a welding pattern comprising a first intermittent weld line having two or more curved welds, wherein the welds are curved concavely with respect to the flow direction, and a second intermittent weld line having two or more curved welds, wherein the welds are curved convexly with respect to the flow direction, and wherein the first intermittent weld line is spaced apart from the second intermittent weld line.

It has surprisingly been found that reflux is minimised when the curved welds of the first and second weld lines are not in alignment, but are horizontally offset with respect to one another. Accordingly, in one preferred embodiment, the curved welds of the second intermittent weld line are horizontally offset with respect to the curved welds of the first intermittent weld line. In such an embodiment, preferably the curved welds of the second intermittent weld line are each aligned centrally within the gap between curved welds of the first intermittent weld line. Such an arrangement has been found to minimise reflux, whilst providing a good flow rate through the NRV.

It has been surprisingly found that the flow rate through the bag is impeded where there is no spacing between the first intermittent weld line of curved welds and the second intermittent weld line of curved welds. In such welding patterns, the lower ends of the concavely curved welds and the upper ends of the convexly curved welds are located along a single line. By contrast, bags having a welding pattern wherein the first intermittent weld line is spaced apart from the second intermittent weld line exhibit a good flow rate. Preferably, this spacing between the first intermittent weld line and the second intermittent weld line is at least about 5mm; more preferably, the spacing is at least about 8mm; most preferably, the spacing is at least about 10mm.

The first and second intermittent weld lines may be generally straight and arranged such that the lines are substantially perpendicular to the flow direction.

Alternatively, the lines may be curved or undulating.

The first and second intermittent weld lines generally comprise sufficient curved welds to exhibit a good flow rate through the bag, while minimising reflux.

Preferably, the first intermittent weld line has three or more curved welds; more preferably, four or more curved welds; for example, four, five or six curved welds.

Preferably, the second intermittent weld line has three or more curved welds; more preferably, four or more curved welds; for example, four, five or six curved welds.

It has been surprisingly found that the flow rate through the bag is impeded where the welding pattern comprises two sets of curved welds that are semi-circular or form one-third of a circle, whereas quarter-circular curved welds do not act to impede the flow rate. Thus, a good flow rate is displayed for bags in which the intermittent weld lines are made up of curved welds, the shape of the curved welds being a substantially circular arc subtending an angle of less than about 1200, preferably about 1100 or less, more preferably about 100° or less, most preferably about 90° or less.

In a preferred embodiment of the invention, the ostomy bag is a urostomy bag.

For the purposes of clarity and a concise description, features are described herein as part of the same or separate embodiments; however it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

The following definitions shall apply throughout the specification and the appended claims.

Within the context of the present specification, the term "comprises" is taken to mean "includes" or "contains", i.e. other integers or features may be present, whereas the term "consists or' is taken to mean "consists exclusively or'.

Within this specification, the term "about" is interpreted to mean optionally ±20%, preferably optionally ±10%, more preferably optionally ±5%.

An embodiment of the invention will now be described with reference to the

following Examples.

Examples

Example 1 -NRV Flow and Reflux Test Flow and reflux analysis of various proposed NRV designs, with comparison to the applicant's earlier NRV design, as used in its manufactured products, was carried out.

Samples Profile Type Welding Pattern Profile A Profile B. . . . Profile C Profile D Profile E. .. . Flow Test -Method The flow test was carried out in accordance with Non Return Valve (BS EN Iso 8669-2: 1996).

Water (1 litre) was poured into a reservoir. The hydrocolloid release liner was removed and the pouch was mounted vertically on a board with the tap facing

S

downwards (custom board with input holes in lab, with affixed drip tray). A container was placed with a funnel under the tap of the urostomy pouch. The reservoir outlet tubing was inserted through the hole in the board to allow for flow into the pouch. Timing was started using a stop watch.

The reservoir was raised allowing for a steady flow to enter through the bag via the stoma. Once 1 litre of water had passed through the pouch, the stop watch was stopped and the duration was recorded.

Flow Test -Results All results are comparable to the duration of 1:13.50 seconds as achieved via emptying the reservoir containing 1 litre of water with no obstruction path.

Flow Test Profile Type Duration (s) Comments Profile A 0:00.00 Weld acted like a seal preventing water to pass Profile B 0:00.00 through NR.V Profile C 1:31.70 Profile D 4:46.30 Profile E 1:28.50 Reflux Test -Method The reflux test was carried out in accordance with Non Return Valve (BS EN ISO 8669-2: 1996). The principle of the test is to add water to the urine collection bag, which is then subjected to a compressive load, and the reflux through the NRV is measured.

For bags having inlet tubing longer than 50 mm, the tubing was cut to a length of 50 mm ± 10 mm. For bags having extensible tubing, the tubes were drawn out to maximum length before cutting. Some bags incorporate the NRV in the inlet tubing. It was ensured that such a valve was not compromised or damaged when cutting.

Water was added to the bag. The bags were filled with water up to half the volume of the bag (in this case 125m1), and sealed.

The bag was placed on a flat, rigid and horizontal surface, with the inlet tubing draining over the edge of this surface.

A flat, rigid plate, of length and width not less than those of the bag being tested, was placed on top of the bag. Restraints capable of allowing the plate to move freely in a vertical direction whilst remaining horizontal within a tolerance of ± 5° were placed in position and the plate was loaded gently with weights so that a total force of 100 N ± SN was imposed on the bag.

The force was allowed to act on the bag for at least 5 mm but no longer than mm 10 5. A graduated cylinder of capacity to suit the bag being tested and the volume passing through the NRV, and having a measurement accuracy of ± 2 0/s, was used to collect and measure the quantity of water emerging from the inlet tubing during that time to an accuracy of ± 2 ml, ignoring any flow occurring before the force was imposed. The rate of leakage past the NRV was calculated in millilitres per minute.

Reflux Test -Results Results for profiles A-D are comparable to the volume output of profile E, which is the applicant's current NRV design.

Reflux Test Profile Type Duration (5mins) Comments Volume (ml) Profile A -Test was not carried ____________________ ____________________ out due to previous Profile B -flow test failure Profile C 0 Profile D 0 Profile E -Product 1 4 Profile E -Product 2 48

NRV Flow and Reflux Test -Summary and Conclusions

Profiles A and B failed the initial flow test due to the arch configuration creating a seal stopping the throughput of water. Profile E (the applicant's earlier NRV design) produced the best throughput time in the flow test. Profile C proved the most comparable to Profile E (the applicant's earlier NRV design) in the flow test.

Profile D did not improve upon or match the current throughput in the flow test.

The reflux test highlighted a potential flaw with Profile E (the applicant's earlier NRV design), since there was quite substantial refiux through the NRV for both of the two commercially available products having an NRV with Profile E. Profile C showed an improvement over Profile E (the applicant's earlier NRV design) in the refiux test, with zero reflux of water through the NRV. Profile D also showed an improvement over Profile E (the applicant's current NRV design) in the reflux test, with zero reflux of water through the NRV, similar to Profile C. From the above results, Profile C shows a distinct improvement over Profile E, which is the NRV design used in the applicant's earlier manufactured products. With a slight variant in throughput of only 0:03.20 seconds in the flow test, and 0 millilitres of reflux through the NRV in the reflux test, Profile C represents an improved NRV design, which would improve the performance of ostomy products.

Example 2 -NRV Flow and Reflux Test with Representative Marketed Products Flow and reflux analysis of the NRV design according to the invention, Profile C, with comparison to both Profile E, the applicant's earlier NRV design, as used in its manufactured products, and a number of representative marketed products was carried out to determine the effectiveness of the NRV design according to the invention.

Samples Profile Type Welding Pattern i.

Profile 1 "".

Profile 2 \ Profile 3 iIII!!1ii1IIII1I -\b' flk' k\\

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Profile4 " -ckj Ijj ProfileE (Schematic) (Photograph) Profile C. .. <:r::

(Schematic) Flow Test -Method The flow test was carried in the same manner as for Example 1 above.

However, two separate tests were performed, firstly to measure the duration taken for the fluid to pass through and empty the NRV, and secondly to measure the duration taken for the fluid to pass through and empty the pouch. For each type of test, the test was repeated three times and an average of the measurements calculated.

Flow Test -Results Flow Test Profile Duration to empty Average Duration to empty Average Type NRV Cs) Cs) pouch Cs) Cs) 1 2 3 1 2 3 Profile 1 1:16.3 1:15.9 1:13.6 1:15.3 1:51.7 1:23.8 1:26.3 1:34.0 Profile 2 1:15.4 1:18.8 1:10.3 1:14.8 1:16.9 1:19.9 1:11.4 1:16.1 Profile 3 1:22.7 1:22.3 1:23.3 1:22.8 2:22.5 2:12.9 2:11.3 2:15.6 Profile 4 1:09.3 1:12.4 1:07.4 1:09.7 1:11.3 1:14.2 1:08.9 1:11.5 Profile E 1:08.9 1:07.6 1:07.4 1:08.0 1:09.9 1:08.7 1:07.9 1:08.8 Profile C 1:16.5 1:16.8 1:22.1 1:18.5 1:20.3 1:23.8 1:35.8 1:26.6 Reflux Test -Method The reflux test was carried in the same manner as for Example 1 above.

However, given the variation in bag capacity for the different products, different test volumes corresponding to half the volume of the bag were used for different bags.

The test was repeated three times and an average of the measurements calculated, as well as the percentage reflux in comparison to the test volume.

Reflux Test -Results Reflux Test Profile Type Test volume Duration (5 mins) Average Percentage (ml) (ml) (%) Volume (ml) 1 2 3 Profile 1 175 160 170 165 165 94 Profile 2 150 122 108 90 107 71 Profile 3 85 15 8 12 12 22 Profile 4 150 102 136 140 126 84 Profile E 125 86 90 68 81 65 ProfileC 125 0 0 0 0 0

NRV Flow and Reflux Test -Summary and Conclusions

From the above flow test results, Profile C demonstrated good initial flow throughput, and Profile 2, Profile 4, and Profile E also performed well in the flow test.

Profile 1 and Profile 3 were both problematic in terms of initial flow throughput in the flow test.

In the refiux test, each of Profile 1, Profile 2, Profile 3, Profile 4, and Profile E showed some degree of reflux through the NRV, with Profile 1 and Profile 4 showing particularly high reflux, Profile 4 losing 94% of its test volume through reflux. By contrast, Profile C demonstrated no reflux through the NRV under the test conditions.

In summary, Profile C shows a distinct improvement over Profile E, which is the NEW design used in the applicant's earlier manufactured products. Profile C also shows a distinct improvement over the other representative marketed products, showing no reflux compared to reflux of from 22% to 94% in the other products, and exhibiting a very comparable throughput in the flow test. Profile C shows only slight variants in initial flow through the NRV and tap outlet, with no reflux through the NEW, so that its use would improve the performance of ostomy products.

The above described embodiments have been given by way of example only.

It will of course be understood that many variations may be made to the above-described embodiments without departing from the scope of the present invention.

Claims

CLAIMS1. An ostomy bag comprising a non-return valve having a welding pattern comprising a first intermittent weld line having two or more curved welds, wherein the welds are curved concavely with respect to the flow direction, and a second intermittent weld line having two or more curved welds, wherein the welds are curved convexly with respect to the flow direction, and wherein the first intermittent weld line is spaced apart from the second intermittent weld line.
2. An ostomy bag according to claim 1, wherein the curved welds of the second intermittent weld line are horizontally offset with respect to the curved welds of the first intermittent weld line.
3. An ostomy bag according to claim 2, wherein the curved welds of the second intermittent weld line are each aligned centrally within the gap between curved welds of the first intermittent weld line.
4. An ostomy bag according to any of claims 1 to 3, wherein the spacing between the first intermittent weld line and the second intermittent weld line is at least about 5mm.
5. An ostomy bag according to claim 4, wherein the spacing between the first intermittent weld line and the second intermittent weld line is at least about 8mm.
6. An ostomy bag according to claim 5, wherein the spacing between the first intermittent weld line and the second intermittent weld line is at least about 10mm.
7. An ostomy bag according to any of claims 1 to 6, wherein the first and second intermittent weld lines are generally straight.
8. An ostomy bag according to any of claims 1 to 6, wherein the first and second intermittent weld lines are curved or undulating.
9. An ostomy bag according to any of claims 1 to 8, wherein the first and second intermittent weld lines are arranged such that they are substantially perpendicular to the flow direction throughout the ostomy bag.
10. An ostomy bag according to any of claims 1 to 9, wherein, the first intermiftent weld line has three or more curved welds; optionally, four or more curved welds; optionally, four, five or six curved welds.
11. An ostomy bag according to any of claims 1 to 10, wherein the second intermittent weld line has three or more curved welds; optionally, four or more curved welds; optionally, four, five or six curved welds.
12. An ostomy bag according to any of claims ito 11, wherein the shape of the curved welds is a substantially circular arc subtending an angle of less than about 1200, optionally about 1100 or less, optionally about 1000 or less, optionally about 900 or less.
13. An ostomy bag according to any of claims ito 12, wherein the ostomy bag is a urostomy bag.
14. An ostomy bag substantially as herein described with reference to theaccompanying description.Amended claims have been filed as follows:-CLAIMS1. An ostomy bag comprising a non-return valve having a welding pattern comprising a first intermittent weld line having two or more curved welds, wherein the welds are curved concavely with respect to the flow direction, and a second intermittent weld line having two or more curved welds, wherein the welds are curved convexly with respect to the flow direction, and wherein the first intermittent weld line is spaced apart from the second intermittent weld line.2. An ostomy bag according to claim 1, wherein the curved welds of the second intermittent weld line are horizontally offset with respect to the curved welds of the first intermittent weld line.3. An ostomy bag according to claim 2, whereIn the curved welds of the second intermittent weld line are each aligned centrally within the gap between curved welds of the first intermittent weld line.4. An ostomy bag according to any of claims 1 to 3, wherein the spacing between the first intermittent weld line and the second intermittent weld line is at least 5mm ±20%. S. *e * S5. An ostomy bag according to claim 4, whereIn the spacing between the first intermittent weld line and the second intermittent weld line is at least about * S. *.*.* 8mm.: 6. An ostomy bag according to claim 5, wherein the spacing between the first intermittent weld line and the second intermittent weld line Is at least 10mm *:": ±20%.7. An ostomy bag according to any of claims 1 to 6, wherein the first and second intermittent weld lines are straight.8. An ostomy bag according to any of claims 1 to 6, wherein the first and second intermittent weld lines are curved or undulating.9. An ostomy bag according to any of claims 1 to 8, wherein the first and second intermittent weld lines are arranged such that they are substantially perpendicular to the flow direction throughout the ostomy bag.10. An ostomy bag according to any of daims 1 to 9, wherein, the first intermittent weld line has three or more curved welds.U. An ostomy bag according to claim 10, wherein the first intermittent weld line has four or more curved welds.12. An ostomy bag according to claim 10 or 11, wherein the first intermittent weld line has four, five or six curved welds.13. An ostomy bag according to any of claims 1 to 10, wherein the second intermittent weld line has three or more curved welds.14. An ostomy bag according to claim 13, wherein the second intermittent weld line has four or more curved welds. S. ** * * *15. An ostomy bag according to claim 13 or 14, wherein the second intermittent weld line has four, five or six curved welds. * S. * * S * S.16. An ostomy bag according to any of claims ito 11, wherein the shape of the : curved welds is a circular arc subtending an angle of less than 1200 ±20%.17. An ostomy bag according to claim 16, wherein the shape of the curved welds is a circular arc subtending an angle of less than 1100 ±20%.18. An ostomy bag according to claim 16 or 17, wherein the shape of the curved welds Is a circular arc subtending an angle of less than 1000 ±20%.19. An ostomy bag according to claim 16, 17 or 18, wherein the shape of the curved welds is a circular arc subtending an angle of less than 900 ±20%.20. An ostomy bag according to any of claims 1 to 19, wherein the ostomy bag is a urostomy bag.21. An ostomy bag substantially as herein described with reference to theaccompanying description. e * . * *S* *.*.* * S * S. * . * * S. * *. * * * **.*.S*** * *