Abstract:
A lesion or fistula isolating bag, the bag defining a first chamber having a closeable entrance and a second chamber for application to a lesion or fistula and wherein access to the second chamber is made through the first chamber via a valve, the valve being arranged to inhibit passage of fluid from the second chamber to the first, and to allow said access from the first chamber to the second, the bag further comprising a closure for said closeable entrance.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This Application is a U.S. National filing under § 371 of International Application No. PCT/GB2004/003520, with an international filing date of Aug. 13, 2004, now pending, claiming priority from Great Britain Application No. GB2003/19139.2, with a filing date of Aug. 14, 2003, now pending, and herein incorporated by reference. 
   TECHNICAL FIELD 
   The present invention relates to devices for providing access to a lesion—such as an ostomy or wound—or to a fistula on a person or animal (hereinafter generically referred to as a “wound”) whilst isolating the wound from a surrounding environment. More specifically, the invention relates to an ostomy, fistula or wound drainage bag for this purpose. 
   BACKGROUND OF THE INVENTION 
   Various devices are known for the dressing of wounds on persons or animals which simultaneously allow access to the wound for inspection and/or for treatment whilst isolating the wound from the surrounding atmosphere. For example, a device known in the art is shown in  FIG. 1 . The device  10 , sometimes known as a window bag, is applied to the skin of the patient  12  over the wound  18 . The device consists of a body  14  which is often of generally circular cross-section and has a lid  16  which may be removably fixed to the body  14  to isolate the wound from the surrounding environment. Access to the wound may be made by removing the lid  16 . These lids and bodies are of generally circular cross-section as the shape tends to allow a more efficient seal when compared to lids and bodies of other shapes. 
   Another type of device that is known in the art is disclosed in United States Design Pat. No. 432,232. This document discloses a wound drainage device which allows access and isolation for the wound and includes a zip fastener access for this purpose. 
   Such devices have several inherent disadvantages. These include the fact that the seals are not particularly efficient; i.e. the zip of US Design Pat. No. 432,232 may not be particularly water tight. Further, neither device offers efficient isolation of the wound from the surrounding atmosphere if the lid is not properly sealed. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention at least to alleviate these problems. 
   The invention is set out in the claims. 
   Embodiments of the present invention provide advantages over the prior art by providing a bag device with first and second chambers and a seal, or valve, between the chambers which inhibits the passage of fluid between the chambers but also allows access for inspection and/or treatment of the wound. In one embodiment of the present invention, this is achieved by providing two or more members which extend inside the bag from its opening and which close to form the valve. In another embodiment of the present invention, the valve is effected by providing a flexible partition which divides the chambers. Access is made to the second chamber from the first chamber through the flexible partition which has two layers, each layer having a respective slit which is offset from the other. Such an arrangement offers effectively a “zig-zag” set up which is the extra “seal” or “valve” in the device and therefore extra protection for the patient&#39;s wound. It would of course be possible to extend this arrangement so that the flexible partition has more than two layers, each layer having its own slit. 
   A further advantage of the present invention is that embodiments may be automatically manufactured using machinery. Many of the devices in the prior art must be manufactured by hand. 
   Applications of the device of the present invention include application to a wound as defined above. In such an application utilising embodiments of the present invention, the bag is fixed to a patient over a wound that he or she has. The user (a doctor or nurse) may open the bag at the entrance and enter his/her hand into the bag and the first chamber. Access can be gained to the wound for inspection and/or further treatment of the wound through the valve and the second chamber. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the present invention will now be described, by way of example only, and with reference to the accompanying drawings in which: 
       FIG. 1  is a diagram showing a window bag as known in the prior art; 
       FIG. 2  is a diagram showing an embodiment of the present invention; 
       FIG. 3  is a diagram showing another embodiment of the present invention; 
       FIGS. 4A and 4B  are diagrams illustrating the manner in which the seal may be operated in the embodiment of  FIG. 3 ; 
       FIGS. 5A and 5B  are diagrams illustrating a further embodiment of the present invention; 
       FIGS. 6A and 6B  are diagrams illustrating the manner in which the seal operates in the embodiment of  FIG. 5  of the present invention; 
       FIGS. 7A and 7B  show yet further embodiment of the present invention; and, 
       FIGS. 8A and 8B  show yet other embodiments of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to  FIG. 2  an embodiment of the present invention is illustrated. The bag  4  comprises an opening or entrance  6 , chambers  7   a  and  7   b  and a valve  9  which isolates one chamber from the other. The bag is placed over the wound  8  of the patient  2  and the user enters his or her hand through the bag entrance  6  into the first chamber  7   a . The valve  9  opens, or access is gained through it, for the user to inspect or treat the wound. Operation of the valve  9 , which may take several forms, is discussed below. 
   Referring now to  FIG. 3 , a device  110  according to an embodiment of the present invention is illustrated. The device  110  comprises first and second chambers  114 ,  116  and a closeable aperture  118  which may be provided by a lid, zip fastener or other suitable closure means. The two chambers  114 ,  116  are separated by a partition comprising two adjacent layers  120 ,  122  each of which has a respective slit  124 ,  126 . As is illustrated, the slits may be oriented in the same direction, but offset from one another. The slits need not be parallel to one another, but may simply be oriented in substantially the same direction. It will also be appreciated that the openings in the layers need not be by means of slits, but may be by any suitable shape of opening. 
   In use, the device  110  is affixed to a patient&#39;s skin  112  and over a wound thereon (not shown). An outer surface of the device is adherent (for example, the outer surface may be coated in adhesive) in order to affix or attach it to a patient. Coating the outer surface of the chamber with adhesive offers a convenient and easy method of fixing the device to the patient. Preferably, the adhesive is of a type approved for medical use such that it does not irritate the patient&#39;s skin or provide any risk of infection to the wound. 
   In an embodiment of the invention, the first layer  120  of the partition may be heavier than the second layer  122 . In this way, the forming of the seal/valve when the user&#39;s hand is withdrawn from the device is enhanced; the additional weight of the first layer of the partition presses down on the second layer such that it presses close against the patient&#39;s body thereby forming the seal. Various means may be used to achieve this additional weight in the first layer, for example, it may be formed of a material which is more dense than the material of the second layer, and/or the material of the first layer is of greater thickness than the material of the second layer. 
   In embodiments of the present invention the closeable aperture  118  in the first chamber is sealable, so that the aperture  118  is watertight. In other embodiments of the invention, the aperture is sealable so that it is airtight thereby increasing the sterility of the device. 
   In embodiments of the present invention the device is made from flexible polymer, for example, any of polyethylene (PE), polyvinyl chloride (PVC) and ethyl (or ethylene) vinyl acetate (EVA). Such polymers offer flexible and convenient-to-manufacture materials for the construction of the chambers or bag. Typically, the first layer  120  of the partition (or first chamber itself) is constructed from PE and the second layer  122  of the partition (or second chamber itself) is constructed from EVA. Other olefins or polyolefins might also be used. In this instance, PE is a slightly heavier material than EVA and, as such, assists the forming of the seal as described above. 
   In an embodiment of the present invention, the offset between the slits is between 15 to 30 mm. However, the offset between the slits may be between 5 mm and 100 mm or between 10 mm and 50 mm. 
   In an embodiment of the invention, the slits  124  and  126  are between 80 mm and 300 mm long depending on the overall size of the device. It has been found that slit lengths in this range offer convenient access without compromising the integrity of the seal offered by the partition. 
   Referring now to  FIG. 4  the manner in which the seal operates and in which a user may gain access to a wound through the device is now discussed.  FIG. 4   a  shows a cutaway of the device  110  illustrating the layers  120  and  122  in relation to the patient&#39;s skin  112 . The wound on the patient&#39;s skin is not shown for the sake of clarity. Also shown in the first layer  120  is the slit  124  and in the second layer  122  is shown the slit  126 . As mentioned above, these slits are offset from one another. The user gains access to the first chamber  114  by opening the closeable aperture  118  which is shown in  FIG. 3 . The user then opens the slit  124  which opens as shown in  FIG. 4   b  as the layer is made of a flexible polymer and then accesses the opening by pushing through in the direction  128  as shown and then through the slit  126 . As the second layer  122  is also made from flexible polymer, as discussed above, the user has access directly through both layers to the wound for inspection and/or treatment. 
   Referring now to  FIG. 5 , another embodiment of the present invention is now discussed. In this embodiment  210  of the device the first and second chambers are formed by the joining together of two bags or bag portions  214 ,  216 . The two bags  214 ,  216  are welded together at  230  as shown in  FIG. 5   b . Various methods of welding may be employed for this purpose, the most suitable having been found to be thermal welding, radio-frequency welding or impulse welding. 
   In this embodiment, the width of the bag (dimension  234  as shown in  FIG. 5   a ) is approximately 50 mm. A bag of this size offers sufficient width for the user to manipulate the chamber or bag to open it, and access the slits  224 ,  226  in order to access to the patient&#39;s wound. Of course, it will be appreciated that other dimensions of this magnitude, say between 200 and 20 mm, or between 150 and 25 mm, or 100 and 30 mm, or 75 and 40 mm may be used depending on the requirements of the particular application. 
   The closeable aperture  218  is formed by means of a plastic (or other suitable material) zip fastener which offers convenient closeable access to the first bag. Plastic zip fasteners on their own are inefficient at providing fluid containment, but coupled with the seal/valve offered by the flexible partition with offset slits, the device offers a secure seal to contain any fluid which may be discharged by the patient&#39;s wound. 
   Alternatively, and as mentioned in the preceding example, the closeable aperture is effected by a removable cover such as a lid. Any other type of closing may be used such as button fasteners, but it is preferable that the aperture is sealable. 
   As mentioned above, the two bags are welded together around the slits at  230 . The zipper weld may be inset to allow the zipper the freedom to be opened easily by the user as shown at  236 . 
   The width of the first bag (zipper bag) is determined such that it suits the dimensions of the second bag (wound bag). 
   The slit  224  in the first bag  214  should be at the bottom of the first bag while the slit  226  in the second bag  216  is situated close to the weld adjacent to the zip  214 . 
   In embodiments of the present invention a further aperture  232  may be provided in device  210 . Multiple further apertures may be provided but a single aperture  232  is illustrated for the sake of simplicity. This aperture (or apertures) may be multi-purpose in that it could be used for the draining of any fluid which is discharged by the wound, for wound irrigation or, could possibly be used for sterile access to the wound, for, for example, an intravenous drip to the patient. 
   The manner in which access may be effected to the patient&#39;s wound with an alternative embodiment is now illustrated in  FIG. 6 . The slits  224 ,  226  are shown in the first and second bags  214 ,  216 . When a user inserts his or her hand through the aperture  218  (the zipper aperture  218  as shown open in  FIG. 6 ), the action of raising the aperture  218  causes the layer  220  of the bag to move in the manner illustrated in  FIG. 6   b . Access may then be made to the second bag  216  in the direction  228  as shown. 
     FIG. 7  illustrates a further alternative embodiment of the present invention which shows an alternative version of the valve of  FIGS. 3 to 6 . In this embodiment the zip  318  is situated on an outside edge of the bag  314 , in this case at the open top of the wound bag which is attached to the patient  316  over the wound  324 . Each side of the zip strip is welded to the front and back of the bag respectively as shown at  330 . The valve  334  is effected by members which extend away from the zip fastener into the bag  314  and is effective when the zip is closed. Access is obtained to the zip bag interior  314  through the open zip  318 , the valve  334  so that the wound  324  may then be accessed. Such a valve which is integral with the zip  318  offers a further level of security to the device so that the likelihood of any leakage of wound discharge or of infection to the wound is greatly reduced. 
   As a further alternative, this valve embodiment could be used in conjunction with the valve of  FIGS. 3 to 6  to provide enhanced isolation between the opening and the wound. 
   The aperture  320  provides a means for passage of fluid into and/or out of the bag. 
   Referring now to  FIG. 8 , a further example of an embodiment of the present invention is shown. This embodiment is a variant of the embodiment of  FIG. 3 , and like reference numerals refer to like parts. The device  110  of  FIG. 8  comprises, again, first and second chambers  114  and  116  and a closeable aperture  118  which, in this example, is in the form of zip fastener. The two chambers  114 ,  116  again are separated by a partition comprising two adjacent layers  120 ,  122  each of which has a respective slit  124 ,  126 . The slits may be orientated in the same direction, but offset from one another although, as mentioned above, this is not absolutely necessary; the slits may simply be oriented in substantially the same direction. Again, the openings in the layers need not be by means of slits, but may be by any suitable shape of openings. Operation of the device is as described above with reference to  FIG. 3 . 
   It will be understood that the present invention has been described above purely by way of example and modifications of detail can be made within the scope of the invention. 
   Each feature disclosed in the description and the claims and drawings may be provided independently or in any appropriate combination. 
   It will also be appreciated that features of one aspect of the invention may be applied to features of another aspect of the invention.