GB2431239A

GB2431239A - A stoma bag including means for sensing when the bag has been filled

Info

Publication number: GB2431239A
Application number: GB0520667A
Authority: GB
Inventors: Paul Harris
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-10-11
Filing date: 2005-10-11
Publication date: 2007-04-18
Also published as: GB0520667D0

Abstract

A bag (e.g. a stoma bag) 1 comprising a means 10 for sensing movement of the opposing walls of the bag away from each other when the bag 1 has been filled to a predetermined height or volume. The sensing means 10 comprises a plurality of contacts 12 in the form of conductive strips which extend along part of the length of the bag 1. The conducting strips 12 are located on opposing portions of the inner walls of the bag 1 to detect when those opposing portions move away from each other.

Description

BAG

The present invention relates to flexible bags and more particularly, but not exclusively to stoma bags.

Colostomies, ileostomies and urostomies are relatively common medical procedures involving redirecting the natural course of the intestine, ileum or urinary tract to an artificial outlet formed in the abdomen wall known as a stoma. A removable bag is adhered to the outside of the abdomen wall to collect faecal matter or urine leaving the intestine, ileum or urinary tract through the stoma. Once the bag has been filled it may be emptied and reused or simply replaced.

However, as the colostomy, ileostomy or urostomy by-passes the sphincter muscle the user does not have control over when the bag is being filled and may not even be aware that it is filling. If the user does not monitor the bag and empty it in due time then the bag may overfill, burst or detach itself from the user.

This is particularly problematic with the elderly who are generally less able to adapt to the new routine brought about by the colostomy, ileostomy or urostomy.

Therefore it is desired to provide an improved stoma bag.

From a first aspect the present invention provides a flexible bag comprising opposed walls, said bag further comprising means for sensing movement of the opposed walls away from each other in use so as to detect filling of the bag.

As the sensing means is configured to detect movement of portions of the opposing walls away from each other the bag is able to detect when it is filling and may be arranged to alert the user that it is appropriate to empty or change the bag before it becomes overly full. Further, as the sensing means detects movement of opposing walls away from each other the sensing means may more accurately detect filling of the bag, as it cannot be actuated by flexing of the bag caused by movement of the wearer rather than filling of the bag.

Preferably, the sensing means is arranged to detect when the bag is filled to a predetermined height or volume in use. The predetermined height or volume is selected so as to give the wearer of the bag adequate time to empty or replace the bag before it becomes overly full. The predetermined height is preferably arranged to be below any aperture in the upper portion of the bag, in particular in one of the opposed walls, e.g. an entrance port in the bag, and preferably is a predetermined distance below such an aperture. Where the bag is a stoma bag, the predetermined height is preferably at least 2 cm and more preferably at least 5cm below the lower edge of the aperture. In this way, the likelihood of leakage may be reduced.

The sensing means may detect when the bag has been filled to the predetermined height or volume by detecting whether or not the walls of the bag have moved apart at a predetermined height on the bag.

Alternatively, the sensing means may detect when the walls of the bag have reached a predetermined separation corresponding to the bag being filled to a selected height or volume. In these arrangements, the sensing means may therefore detect when the walls have separated by at least a predetermined minimum distance. This may help avoid accidental or premature determination of filling of the bag, e.g. in response to a de minimis movement of the walls away from each other for reasons unrelated to the filling of the bag in use.

The sensing means may be any means capable of detecting the movement of opposing walls of the bag away from each other as the bag fills in use, and may be any mechanical, chemical and/or electrical sensing means, or a combination thereof.

However, in the preferred embodiments the sensing means is an electrical sensing means, and may include any electronic component or components suitable for sensing movement of the opposing walls away from each other in use. Preferably the sensing means uses an electrical circuit to detect moving of the walls away from one another in use. For example, the sensing means may be arranged to detect an increase or decrease in the current in an electrical circuit associated therewith to sense moving of the walls away from one another in use.

Preferably the sensing means is arranged to detect breaking of an electrical circuit associated therewith to sense filling of the bag in use.

Preferably the sensing means includes first and second components associated with the opposed walls of the bag, and means for detecting movement of the first and second components away from one another on filling of the bag in use. Preferably, the components face one another. Preferably the components co-operate with one another to sense separation of the walls.

The means for detecting movement of the first and second components away from one another may be a separate means, or, for example, the two components may form part of a circuit for sensing movement of them away from one another in use.

In some preferred embodiments one of the components is arranged to emit a signal which is received by the opposed second component in use, the sensing means being responsive to a change in the signal detected by the second component to indicate filling of the bag. The change in the signal may be a decrease or increase in the signal, or a cessation thereof. The signal may be an electrical signal, or an electromagnetic signal, e.g. a visible or non-visible light signal. The sensing means may for example, include a light emitter and a light dependent resistor.

Preferably, the sensing means comprises a switch or sensor. For example, the sensing means may comprise a polymer based sensor, preferably located on the inner surface of the bag.

In embodiments wherein the sensing means is electrical, means for powering the sensing means is preferably provided. The means may be passive or active. The means for powering the sensing means is preferably integral with bag and may, for example, comprise a battery. In the preferred embodiment, the sensing means comprises one or more electrical circuits preferably integral with bag. It will be appreciated that any electrical sensing means may be powered remotely, by a power supply connected using wires, or wirelessly, to the sensing means. The sensing means may comprise one or more passive components. However, in some arrangements, a power supply may not be required.

For example, the sensing means might be charged before use, thus avoiding the need to provide a power supply associated therewith.

Preferably, the bag comprises first and second members which are associated with the respective opposed walls, whereby the members are arranged to move away from one another in use on separation of the opposed walls. Preferably the first and second members are disposed on the inner surfaces of the respective walls.

Preferably the sensing means is responsive to breaking of an electrical circuit to detect filling of the bag in use. Preferably the sensing means comprises a pair of contacts associated with the respective opposed walls, and detects breaking of said contacts to indicate filling of the bag in use.

Preferably the first and second members are therefore electrical contacts, i.e. electrodes. In a preferred embodiment the bag comprises at least one pair of contacts arranged on the inner surfaces of the opposed walls of the bag. The contacts should in these embodiments be arranged on the opposing walls such that they contact each other when the walls are not spaced apart, e.g. when the bag is empty in its "pre-use" configuration, and before the bag has filled to any desired predetermined level or volume, but such that they may be forced apart on filling of the bag in use.

The contacts may be arranged to form part of an electrical circuit in any suitable manner, such that they complete the circuit when the bag is empty, and open to break the circuit on filling of the bag, preferably to a predetermined volume or level. The contacts may gradually move away from one another as the bag fills, or may suddenly "snap" open when a predetermined level of filling is attained as described below.

The sensing means may be configured to continually sense filling of the bag, or may sense only when the bag has been filled to a predetermined height or volume.

Where the sensing means is located at a particular height, e.g. where it comprises first or second members or contacts located at a given height in the bag, the sensing means may detect filling of the bag to a predetermined level corresponding to the height of the sensing means or a different height. For example, a pair of contacts may be forced apart when the bag has filled to a level below that defined by the contacts, but which causes separation of the walls at the height of the contacts. Thus the level of the sensing means need not necessarily correspond to the level of filling required to force the contacts apart. The level at which the sensing means is arranged to sense filling of the bag to a predetermined level may be determined empirically, e.g. with respect to the nature of the matter the bag is to receive, and the configuration of the bag.

The sensing means may be arranged to permit predetermined detecting of filling of the bag to a plurality of different levels or volumes. In this way, the sensing means may detect a progressive filling of the bag. This may allow a user to have warning that the bag may need to be emptied shortly, and to have an indication as to how full the bag is, allowing them to plan appropriately. The or each predetermined level or volume, in embodiments where the sensing means detects filling of the bag to one or more predetermined levels, may be a set level or volume, e.g. determined in manufacture. Alternatively, the bag may be configured whereby the user may select the, each or a, predetermined level. For example, the bag may have sensing means for sensing filling of the bag to a plurality of different levels, and the user may select one or more of these levels for the sensing means to be responsive to in use. The or each predetermined level may be a fixed level, or may be adjustable. For example, the bag may include movable contacts.

In embodiments using contacts, the contacts may be of any shape or size. For example, they may be point contacts. However, preferably the contacts are strip contacts. In a preferred embodiment, the contacts are a pair of conductive strips, preferably arranged to extend a substantial distance from a lower region of the bag towards an upper region of the bag. In these embodiments filling of the bag causes the contacts to be progressively forced apart from each other along their length beginning in the lower region of the bag and continuing towards the upper region as the bag fills.

The area of contact between the contacts thus progressively decreases as the bag is filled and may be arranged to cause an increase in the resistance in an electrical circuit of the sensing means associated with the contacts. Preferably the sensing means is therefore responsive to a decrease in the surface area of contact between a pair of contacts associated with the opposed walls of the bag to detect separation of the walls in use.

Preferably, each of the opposing walls comprises contacts in the form of a plurality of longitudinally arranged conductive strips located parallel to each other and spaced apart in a direction along the width of the bag.

It will be appreciated that the contacts are associated with an electrical circuit. In these arrangements, the sensing means may therefore be responsive to an increase in the resistance in an electrical circuit associated with the bag to detect filling of the bag in use. By "associated" with, it will be understood that the circuit may be remote from or integral with the or a contact or arranged in any manner such that it is operatively connected to the contacts. The contacts may be associated via wires, wirelessly or via a PCB with the circuit. The same applies in respect of any other components of the sensing means which may be operatively associated in any way with one another.

The sensing means may be arranged to activate an alarm once the resistance in the circuit has increased to a predetermined level which corresponds to the bag being filled to a predetermined height or volume.

In an alternative set of embodiments the contacts on the opposing walls are relatively small or point contacts. Preferably, the contacts are arranged so that they remain entirely in contact with each other over substantially their entire surface area until the bag has been filled to a predetermined height or volume, at which stage the contacts are forced apart breaking an electrical circuit associated therewith. In other words, the sensing means is arranged to detect a sudden breaking of the contacts. The contacts may be configured to "snap" apart on separation of the walls of the bag by a predetermined amount. Once the electrical circuit has been broken an alarm may be activated.

The bag may comprise only a single pair of contacts. However, it will be appreciated that if it is desired to be able to detect filling of the bag to a plurality of different predetermined levels in use, the bag may comprise a plurality of pairs of contacts arranged at different heights.

In a preferred embodiment, the bag comprises a plurality of pairs of contacts spaced apart along the height of the bag. The contacts on opposing walls are aligned so that each contact on one wall cooperates with a contact on the opposed wall to form a plurality of electrical connections at different heights. This embodiment has the advantage that the bag may be arranged to sense filling to any one of a plurality of discrete heights or volumes corresponding to the respective plurality of sets of contacts. In this way one or more pairs of contacts at a particular height on the bag may be selected to activate an alarm when they are disconnected. As such, the user can choose the height or volume of filling to be detected, or at which an alarm is to be activated.

In an alternative embodiment, instead of providing a plurality of contacts on both opposing walls of the bag a first wall is provided with a single contact which extends along a substantial height, i.e. length bottom to top, of the bag and the second opposing wall is provided with a plurality of relatively short contacts which are spaced apart along the same substantial height - 10 - of the bag. Preferably, the plurality of contacts on the second wall are arranged to be contactable with the single contact to form a plurality of electrical connections. This embodiment is advantageous in that the contacts are more easily alignable.

Preferably, the opposing walls are arranged to be biased towards each other in the region of the sensing means. The walls may therefore present a greater resistance to separation at least in the region of the sensing means, thus helping to prevent the opposing walls from separating and activating an alarm due to movement or bending of the bag rather than filling.

Preferably the walls are arranged to be biased towards one another magnetically. Preferably at least a portion of each wall is magnetised, or is associated with a magnetic component. Preferably the biasing means comprises components associated with the opposing walls which are magnetically attracted to each other. In the embodiments wherein the sensing means comprises contacts, the contacts are preferably magnetised so that the opposing walls of the bag are biased towards each other. Alternatively, or in addition, to the contacts being magnetised other magnetised components may be provided in the region of the sensing means to bias the walls towards each other. It will be appreciated that the force required to separate the walls, and hence the height or volume of filling of the bag at which the alarm is activated, can be chosen by selecting the location, shape and size of the magnetised contacts or by altering the strength, area or location of the magnetic material in the walls of the bag.

- 11 - Preferably, the sensing means is located so that matter entering into the bag does not interfere with the sensing means. In a preferred embodiment the sensing means is arranged adjacent to one or both of the lateral side edges of the bag. Preferably the sensing means is remote from any aperture in either of the opposed walls of the bag. Preferably the sensing means is spaced by a distance of at least 2 cm from the periphery of any aperture in either opposed wall of the bag.

The bag may be a single piece bag such as a pouch.

Alternatively, the bag may comprise first and second sections which releasably connect to each other to define the bag.

Where the bag is intended to be worn, preferably the bag comprises an attachment portion for attaching the bag to a wearer in use. Preferably the attachment portion therefore at least partially surrounds an aperture in one of the opposed walls of the bag.

Preferably, the bag comprises a pouch for storing waste matter in use and an attachment portion for attaching the bag to a wearer in use. The pouch may be a one or multi-piece pouch. Preferably the attachment portion then lies between the body of a wearer and a surface of one of the opposed walls in use. In other arrangements, the attachment portion may define at least a part of a wall of the pouch or bag.

Where an attachment portion is provided, preferably the attachment portion comprises a relatively rigid and/or resilient substrate. The attachment portion may reinforce the bag in the region of an opening in an opposed wall thereof. Preferably the attachment portion further comprises means for attaching the bag to a user.

- 12 - The attachment means may be mechanical or adhesive means. Preferably the attachment portion comprises an adhesive layer on a bodyfacing surface thereof. A release layer may be provided to protect the adhesive layer prior to use.

Preferably the bag is a plastics bag. Preferably the bag comprises two sheets of thermoplastic material joined to one another around a periphery thereof to define an enclosure. Preferably the bag is sealed along at least its upper and side edges. The bag may include a releasable opening at one end thereof to allow emptying of the bag. However, preferably the bag is sealed around its entire periphery. Preferably the bag includes an aperture in one of the opposing walls thereof. Preferably the aperture is spaced from all edges of the bag. Preferably the only aperture defined in the bag is in one of the opposing walls of the bag.

Preferably the bag has a height of less than 50cm, and preferably less than 30cm. Preferably the bag has a height of at least 10cm, and preferably at least 20cm.

Preferably the width of the bag is less than 20cm, and is preferably greater than 10cm. The height is the extent of the bag as taken from the edge intended to be lowermost in use i.e. which fills first.

Preferably the bag is a disposable bag. By this it is meant that the bag is not intended to be laundered or for repeated reuse, more than around 10 times. The bag may be intended for single use only. In that case, the present invention provides an indication that the bag needs discarding or replacing.

- 13 - Preferably, the bag comprises means for alerting a user when the bag is filled, preferably to a predetermined level or volume.

The alert may be in any suitable form, and may be in the form of an audible, visible, or other sensory alert. The alert may be a tactile alert. For example, the alert may be in the form of a vibrational alert, or may be in the form of a minor electric discharge or shock.

Preferably the sensing means is arranged to activate an alarm in use on detecting filling of the bag. The alarm may be integral with bag or may be a separate remote device. The sensing means may activate the alarm in any suitable manner. For example, the sensing means may emit a signal indicative of filling of the bag. The signal may be an electrical or electromagnetic signal. The signal may be an internal or external signal with respect to the sensing means.

The signal may be transmitted using wires, or wirelessly, or may be transmitted e.g. in a printed circuit board of an electrical circuit associated with the sensing means. The signal may then be detected by an alarm circuit or device to provide a suitable alert to a user.

In some arrangements an alarm is provided integrally with the sensing means. Thus the sensing means may send an internal signal to the alarm. In some arrangements where the sensing means is electrical, an alarm may be provided as part of the circuitry associated with the sensing means.

Where the bag is intended to contact the skin of a wearer in use, in the preferred embodiment, an alarm is - 14 - arranged on the bag so as to contact the skin of the wearer in use. The provision of the alarm on a part of the bag which contacts the skin of the wearer in use is particularly advantageous in that it is able to discreetly warn the user that the bag will need to be emptied or changed. The alarm may be located in or on the surface of an attachment portion of the bag that contacts the wearer in use.

In the preferred embodiment the alarm is a contact configured to deliver a relatively small electrical charge to the user. In this embodiment the alarm preferably comprises one or more ring contacts that circumscribe an inlet opening to the bag.

Alternatively, or additionally, the alarm may comprise means for providing vibrational, visible and/or an audible alert to the user in use.

From another aspect the present invention provides an attachment portion for attaching a flexible bag to a human body, the attachment portion comprising a skin contacting surface defining an aperture for attaching the bag around a stoma in use, and wherein the attachment portion comprises an alarm for providing an alert to the user in response to a signal indicating filling of a bag associated with said attachment portion in use to a predetermined level.

It is also contemplated herein that the alarm could be a remote device separate from the bag, or that a remote alarm may be provided in addition to the alarm on the bag. The remote alarm should comprise means for receiving a signal from the bag when the bag has been filled to a predetermined height or volume in use. The remote alarm may be electrically connected to the bag, - 15 - for example, by a wire or lead. Alternatively, the bag may comprise a transmitter and the remote alarm may comprise a receiver so as to provide a wireless connection in use.

The invention extends to a system comprising a bag having sensing means for detecting filling thereof in accordance with any of the aspect or embodiments described and an alarm for providing an alert to the user in response to the sensing means detecting filling of the bag. The invention also extends to a method of using such a system or a bag in accordance with the claim, comprising the step of arranging the sensing means to activate an alarm on detecting filling of the bag in use, and arranging an alarm responsive thereto to provide an alert to the user on filling of the bag.

The sensing means may be located in any appropriate manner to allow it to sense separation of the opposing walls of the bag. Thus the sensing means may located within, or outside the bag, or may be integrally formed with a wall of the bag. Preferably the sensing means is located on at least one inner surface of the bag, preferably an inner surface of one of the opposing walls. However, it will be appreciated that the sensing means might alternatively be arranged at least in part to be associated with an internal wall of the bag, e.g. where the bag defines a plurality of compartments.

Preferably the sensing means lies completely within the bag.

Where the sensing means is located within the bag, it may more accurately respond to filling of the bag, and is less likely to be subject to external interference of the surrounding environment. The bag - 16 - may be more robust, and may be less bulky than where the sensing means is provided externally to the bag. It is believed that the provision of a bag having means for detecting filling of the bag and located within the bag is advantageous in its own right.

From another aspect the present invention provides a flexible bag comprising means for sensing the filling of the bag, wherein the means for sensing is located within the bag. Preferably, the sensing means lies completely within the bag. Preferably the sensing means is located on the inner surface of at least one of the external walls of the bag. However, it will be appreciated that in these embodiments the sensing means could instead be provided completely or partially on or in an internal wall of the bag e.g. a dividing wall where the bag defines more than one compartment.

In these further aspects, the bag may comprise any or all of the features described with respect of the first aspect. Thus the sensing means may be of the configuration described above, and may be arranged to activate an alarm as described in respect of any of the above embodiments. The sensing means may be arranged to sense filling of the bag to one or more predetermined levels as described above. The bag may be of the construction and may incorporate any of the other features described above. The sensing means may detect separation of the walls, or, however, in this further aspect may sense filling of the bag in any other manner.

It is also contemplated herein that any sensing means may be provided in the bag in order to detect when it has been filled to a predetermined height or volume.

The sensor may comprise electronic, chemical and/or - 17 - mechanical sensing means. For example, a temperature based sensor may be provided in the bag, preferably on the wall which lies furthest from the body of the user in use. Alternatively, a chemical sensor such as a pH detector may be provided.

Although the bag has been described with particular reference to a stoma or garment bag intended to be worn by a user, it is believed that the present invention in any of its aspects and embodiments has wider applicability in any context where it is desired to sense filling of a bag. It will be understood the bag of the present invention may be used in any application to sense a predetermined amount of filling or emptying of the bag by liquids, gases or solids. For example, the bag could be used as a dispensing bag, e.g. a medical drug drip bag. Alternatively, the bag may be used as a collection bag, e.g. for collecting condensate from de-humidifiers. However, preferably, the bag is a medical bag and most preferably a stoma bag for attaching to an abdominal wall of the user.

Various embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 shows a preferred embodiment of the stoma bag; Fig. 2 shows a partial view of a cross-section through a preferred embodiment of the switching mechanism; and Fig. 3 shows a partial view of a preferred alarm mechanism.

A preferred embodiment of the invention will now be described with reference to Figs. 1 to 3. Fig. 1 shows - 18 - an embodiment of the invention applied to a conventional colostomy bag.

The colostomy bag 1 comprises an attachment portion 4 having an entrance opening 6 and an impermeable flexible bag 2 constructed from two plastic sheets sealed around the periphery. The attachment portion 4 is preferably a relatively resilient portion of the bag 1 or a flange portion having an adhesive thereon to facilitate attachment of the colostomy bag 1 to the abdominal wall of the user. The attachment portion 4 may either be integral with the bag 2 or may be a separate component which is releasably connectable to the flexible bag 2. In the embodiment wherein the attachment portion 4 is a separate component the bag 2 may be removed to be emptied or replaced without disconnecting the attachment portion 4 from the skin of the wearer. This reduces irritation to the skin of the wearer. The colostomy bag 1 may also have a reclosable exit orifice 8 for emptyingthe bag 2. The exit orifice 8 may be closed and reopened by folding and unfolding a lower portion 9 of the bag 2. The exit orifice 8 may be held closed by a releasable fastener that maintains the lower portion 9 folded.

The bag 1 comprises a means 10 for sensing movement of the opposing walls away from each other. The sensing means 10 comprises a plurality of contacts 12 in the form of conductive strips which extend along part of the length of the bag. The conductive strips 12 are located on opposing portions of the inner walls of the bag 2 as seen more clearly in Fig. 2.

Fig. 2 shows a cross-section through a portion of the bag 2. The conductive strips 12 form part of an - 19 - electric circuit which is connected to a battery in or on the bag 1. When the conductive strips 12 on opposing walls are in contact they complete the electrical circuit. Preferably, the conductive strips 12 are magnetised so that the strips 12 on opposing walls are biased into contact with each other. This prevents the opposing walls and conductive strips 12 from moving apart due to movement and flexing of the bag 2 during use.

In use, faecal matter enters through the entrance opening 6 and falls to the bottom of the bag 2 forcing the opposing walls apart in the lower region of the bag 2. The opposing walls are initially held together in the vicinity of the conductive strips 12 due to their magnetic attraction. As the bag 2 fills the opposing walls are forced apart at increasing heights in the bag.

Once the bag 2 has been filled to a certain height or volume the force acting to push the opposing walls apart overcomes the magnetic attraction of the conductive strips 12 and the conductive strips 12 begin to be forced apart starting from the lower end. As the bag 2 continues to fill the opposing conductive strips 12 are increasingly forced apart reducing the area of contact between them. This results in a corresponding increase in the resistance in the electrical circuit. When the bag is filled to a predetermined height or volume the electrical resistance in the circuit increases to a predetermined level which causes an alarm 14 to be activated warning the user that the bag 2 will soon be required to be emptied or changed.

In an alternative embodiment, instead of providing continuous conductive strips 12 on opposing walls of the - 20 - bag 2 the contacts may simply be a pair of relatively small contacts arranged at a predetermined height on the bag 2. In this embodiment, the contacts are sized and arranged so that they remain in complete contact until the bag 2 is filled to a predetermined level, at which point the contacts are completely forced out of contact so that the electrical circuit is broken. This breaking of the circuit activates the alarm 14. In another embodiment a plurality of pairs of electrical contacts are provided spaced along the length of the bag. In this embodiment the pair of contacts which activates the alarm 14 may be selected and hence the user can select the level of filling required to activate the alarm 14.

Alternatively, two or more particular pairs of contacts may be required to be forced out of contact to activate the alarm 14.

Preferably, the contacts of the switching mechanism are arranged only adjacent the side edges of the bag 2 SO that contact between them is not broken by waste material falling into the bag 2 from the entrance opening 6.

In the preferred embodiment, the alarm comprises contact rings 14. When the sensing means 10 detects that the bag 1 has been filled to a predetermined level or volume, power is supplied to the contact rings 14 located on the attachment portion 6 of the bag 1.

Fig. 3 shows an enlarged partial view of the contact rings 14. When power is supplied to the contact rings 14 a relatively small amount of charge is delivered to the skin of the user. This discreetly alerts the user that the bag 2 has been filled to a - 21 - predetermined height or volume and will be required to be changed shortly.

Although the present invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the scope of the invention as set forth in the accompanying claims.

Claims

- 22 - Claims: 1. A flexible bag comprising opposed walls, said bag

further comprising means for sensing movement of the opposed walls away from each other so as to detect filling of the bag in use.
2. A bag as claimed in claim 1, wherein said bag is a stoma bag.
3. A bag as claimed in claim 1 or 2, wherein said bag comprises an aperture located in one of said walls to allow solids and/or fluids to enter the bag in use.
4. A bag as claimed in any preceding claim, wherein the means for sensing is arranged to detect filling of the bag to at least one predetermined height or volume in use.
5. A bag as claimed in any preceding claim, wherein said means for sensing is located in or on the inner surfaces of the opposed walls.
6. A bag as claimed in any preceding claim, wherein said means for sensing is responsive to the breaking of an electrical circuit.
7. A bag as claimed in claim 6, wherein the means for sensing comprises at least one pair of contacts - 23 - arranged to face one another on respective inner surfaces of said opposed walls, the contacts being moveable away from one another in use on filling of the bag to break an electrical circuit associated with the sensing means.
8. A bag as claimed in claim 7, wherein the contacts are in the form of conductive strips.
9. A bag as claimed in claim 7, wherein said bag comprises a plurality of pairs of contacts located at different heights on the bag, said pairs of contacts being arranged to sense filling of the bag to different heights or volumes in use.
10. A bag as claimed in any preceding claim, further comprising means for biasing said opposed walls towards each other.
11. A bag as claimed in claim 7, 8 or 9, wherein the contacts are magnetised.
12. A flexible bag comprising means for sensing filling of the bag, wherein the means for sensing is located within the bag.
13. A bag as claimed in any preceding claim, wherein the bag is in the form of a single piece pouch.
14. A bag as claimed in any of claims 1 to 12, wherein the bag comprises first and second sections - 24 - releasably attachable to one another to define said bag.
15. A bag as claimed in any of claims 1-13, wherein the bag comprises a pouch portion for storing matter in use and an attachment portion comprising a skin contacting surface defining an aperture.
16. A bag as claimed in claim 15, wherein said attachment portion defines, at least a part of said pouch portion.
17. A bag as claimed in any preceding claim, further comprising means for activating an alarm when the bag sensing means detects filling of the bag to a predetermined height or volume in use.
18. A bag as claimed in any preceding claim, further comprising an alarm for alerting a user when the bag has filled to a predetermined height of volume in use.
19. A bag as claimed in claim 18, wherein the alarm is arranged on a portion of the bag which contacts the skin of the user in use.
20. A bag as claimed in claim 19, wherein the alarm is arranged to at least partially surround an aperture in one of the opposed walls of the bag.

- 25 -
21. A bag as claimed in claim 18, 19 or 20, wherein the alarm is arranged to provide an alert to the user in the form of an electric shock.
22. A bag as claimed in claim 18, 19 or 20, wherein the alarm is arranged to provide a vibrational, visible or audible alert to the user in use.
23. An attachment portion for attaching a flexible bag to a human body, the attachment portion comprising a skin contacting surface defining an aperture for attaching the bag around a stoma in use, and wherein the attachment portion comprises an alarm for providing an alert to the user in response to a signal indicating filling of a bag associated with said attachment portion to a predetermined level in use.
24. The attachment portion of claim 23 in combination with a flexible bag in accordance with any of claims 1-22.
25. An alert system comprising a bag as claimed in any of claims 1-22 and a remote alarm responsive to an output of said sensing means on detection of filling of the bag in use.
26. An alert system as claimed in claim 25, wherein the remote alarm is electrically connected to the bag so as to receive said signal from the bag in use.

- 26 -
27. An alert system as claimed in claim 25, wherein the bag comprises a transmitter and the alarm comprises a receiver for providing a wireless connection between the bag and alarm.
28. A bag, attachment portion or alert system as hereinbefore described with reference to any one of the accompanying drawings.