Abstract:
A fluid-containing conduit ( 10,30,40,50 ) including at least one luminescent marker ( 14 ) whereby the fluid-containing conduit is visible in a low light condition. The marker may be in the form of one or more elongate ribs ( 16 ) containing luminescent material along interior wall surface ( 18 ), or may be elongate luminescent bands ( 52,54 ) adjacent the exterior wall ( 20 ) of the conduit, or may be indicia containing luminescent material such as ink ( 42 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority under 35 USC §371 from PCT/GB2006/002059 filed Jun. 5, 2006. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a fluid conveying conduit and, in particular, a medical tube for administering fluids. 
       BACKGROUND OF THE INVENTION 
       [0003]    In a low light condition it is often almost impossible to see a conventional tube or other fluid conveying conduit. As a result a user can find it difficult to locate the conduit if, for example, he wishes to move the conduit or engage and/or disengage a component from the conduit. 
         [0004]    In addition, because conventional conduits are difficult to see in low light conditions it can be difficult for a person to avoid such a conduit if, e.g. it lies across his path, in a low light condition. 
         [0005]    This is particularly so for medical tubes which may be used to provide a person with a continuous supply of oxygen, or to administer drugs to a person, while he is resident in a medical facility or at home. 
         [0006]    In order for the person to move around, the length of medical tubing extending between the person and the dispensing station is often long, especially when a person needs to move from one room to another. As a result, lengths of medical tubing typically lie along the floor in several areas of the medical facility or home. 
         [0007]    As mentioned, such medical tubing is almost impossible to see in low light conditions and so represents a major trip hazard since it is difficult for patients and carers to avoid. As a result many patients and carers suffer falls, some fatal, as a result of tripping over a length of medical tube. 
         [0008]    Therefore, there is a need for an improved fluid conveying conduit which helps to overcome the aforementioned problems. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    According to a first aspect of the invention there is provided a fluid conveying conduit comprising a conduit body including at least one luminescent marker, whereby the fluid conveying conduit is visible in a low light condition. 
         [0010]    Rendering the fluid conveying conduit visible in a low light condition makes it easier for users and their carers to avoid the conduit, thereby reducing the likelihood of a trip occurring. 
         [0011]    In one embodiment of the invention the conduit body defines a medical tube for administering fluids. 
         [0012]    Preferably the or each luminescent marker includes an elongate, luminescent rib extending along the length of the conduit body, the or each elongate rib including a luminescent pigment. The provision of at least one elongate, luminescent rib means that the entire length of conduit is visible in a low light condition. An elongate rib is also readily manufacturable, e.g. by extrusion. 
         [0013]    Optionally at least one elongate rib lies adjacent to an inner surface of the conduit body. Such a rib helps to reduce the likelihood of the tube kinking which might otherwise cut off the supply of fluid being administered to a user. 
         [0014]    Alternatively at least one elongate rib lies adjacent to an outer surface of the conduit body. Such a feature provides a user or carer with a tactile identifier which could, for example allow him to readily identify the fluid being administered by a given medical tube. 
         [0015]    Preferably the or each luminescent marker includes an elongate, luminescent band lying within the conduit body and extending along the length thereof, the or each elongate band including a luminescent pigment. Such an arrangement isolates the or each elongate band from the inner surface of the conduit body, thereby avoiding the possibility of the luminescent pigment adversely reacting with the fluid being conveyed. 
         [0016]    In a preferred embodiment of the invention at least one portion of one or more of the elongate bands is coterminous with an outer surface of the conduit body. This arrangement is readily manufacturable while ensuring a desired amount of one or more elongate bands is visible. 
         [0017]    The luminescent marker may also include an ink lying on a surface of the conduit body, the ink including a luminescent pigment. Such a feature allows the luminescent marker to be readily applied to a surface of the conduit body, by a method such as printing, in a range of differing configurations and graphical arrangements. In this way the luminescent marker may provide additional information, e.g. relating to the contents of the conduit, as well as rendering the conduit visible in a low light condition. 
         [0018]    The conduit body may also include one or more dyes or secondary pigments so as to emit or reflect incident light in a predetermined range of wavelengths. In this way the conduit body is observed to have a particular colour which may be used to identify the fluid being administered by the conduit. 
         [0019]    In a preferred embodiment the conduit body may include a translucent portion. This allows a user or carer to observe the contents of the conduit, while the conduit body also provides the aforementioned colour-based identification. 
         [0020]    Alternatively the conduit body includes a transparent portion so that a user or carer is able to observe the contents of the conduit. 
         [0021]    In another preferred embodiment, the conduit body includes a luminescent pigment. This allows the whole conduit body to define a luminescent marker, thereby providing the desired visibility in a low light condition. 
         [0022]    In a further preferred embodiment, the luminescent pigment may be or include a phosphorescent pigment. Such pigments glow for a period after exposure to light. 
         [0023]    Optionally the luminescent pigment includes one or more dyes or secondary pigments so as to emit light in a predetermined range of wavelengths. In this way the or each luminescent marker is observed to have a particular colour in a low light condition. The colour could then be used to identify the fluid being, e.g. administered by the conduit. Such identification is particularly useful in situations where several different conduits are used to administer different drugs to the same person. The ability of, e.g. a carer, to readily identify, in a low light condition, the fluid being administered by a particular conduit would help to ensure that each drug is injected into the correct conduit. Preferably the conduit body includes an antimicrobial additive. This can help to reduce the transmission of organisms such as MRSA (methicillin resistant  Staphylococcus aureus ) by the conduit, thereby reducing the risk of a conduit user developing an infection. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    There now follows a brief description of preferred embodiments of the invention, by way of non-limiting examples, with reference being made to the accompanying drawings in which: 
           [0025]      FIG. 1  shows a section of medical tube according to a first embodiment of the invention; 
           [0026]      FIG. 2  shows a section of medical tube according to a second embodiment of the invention; 
           [0027]      FIG. 3  shows a section of medical tube according to a third embodiment of the invention; 
           [0028]      FIG. 4  shows a cross-sectional view through a section of medical tube according to the first embodiment of the invention; and 
           [0029]      FIG. 5  shows a section of medical tube according to a fourth embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0030]    In the drawings, like numerals indicate like elements throughout. Certain terminology is used herein for convenience only and is not to be taken as a limitation on the present invention. The embodiments illustrated below are not intended to be exhaustive or to limit the invention to the precise form disclosed. These embodiments are chosen and described to best explain the principle of the invention and its application and practical use and to enable others skilled in the art to best utilize the invention. 
         [0031]    A fluid conveying conduit according to a first embodiment of the invention is designated generally by the reference numeral  10 , as shown in  FIG. 1 . 
         [0032]    The fluid conveying conduit  10  comprises a conduit body  12  which defines a medical tube for administering fluids. The conduit body  12  includes three luminescent markers  14 . Each luminescent marker  14  includes an elongate, luminescent rib  16  which extends along the length of the conduit body  12 . Each elongate rib  16  includes a luminescent pigment (not shown). In a preferred embodiment the luminescent pigment is a phosphorescent pigment. A particularly preferred phosphorescent pigment is alkaline earth metal silicate aluminate. 
         [0033]    In the embodiment shown, all three elongate ribs  16  lie adjacent to an inner surface  18  of the conduit body  12 , as shown in  FIG. 4 . The elongate ribs  16  are equally spaced from one another around the inner surface  18  of the conduit. In other embodiments, of the invention one or more elongate ribs  16  may lie adjacent to an outer surface  20  of the conduit body  12 . In addition, other embodiments of the invention may include different numbers and arrangements of elongate ribs  16 . Furthermore, different shapes of cross-sectional profile are also possible. 
         [0034]    In a low light condition, i.e. typically less than 1 lumen, each elongate rib  16  emits light so as to render the conduit visible to a user or carer. Each elongate rib  16  is able to emit visible light for many hours without the need for an external power source. 
         [0035]    In the embodiment shown in  FIG. 1 , the entire conduit body  12  is transparent which means a user or carer is able to see the contents of the conduit  10 . One type of polymer from which it is convenient to make the conduit body  12  is PVC. 
         [0036]    In other embodiments, not shown, the conduit body  12  may include one or more dyes or secondary pigments so as to emit or reflect incident light in a predetermined range of wavelengths. In this way it is possible to provide a translucent conduit body  12  which has a predetermined tint, so as to provide a visible indication of what fluid is being administered by the tube  10 . A desirable level of translucency, or tinting, is 5% as this provides a suitable visible indication while still allowing the contents of the conduit  10  to be seen. 
         [0037]    The luminescent pigment in one or more elongate ribs  16  may also include one or more dyes or secondary pigments. In such embodiments, each elongate rib  16 , in use, emits light of a particular colour. This provides a visible indication of what fluid is being administered by the conduit  10  in a low light condition. 
         [0038]    A fluid conveying conduit according to a second embodiment of the invention is designated generally by the reference numeral  30 . The second fluid conveying conduit  30  shares many features with the first fluid conveying conduit  10 . These common features are designated by the same reference numerals. 
         [0039]    The second fluid conveying conduit  30  includes an opaque conduit body  12  which defines a medical tube, and has three elongate ribs  16  integrally moulded therewith. Each elongate rib  16  extends along the length of the conduit body  12 . 
         [0040]    The conduit body  12  and each elongate rib  16  includes a luminescent pigment (not shown). Consequently, in a low light condition, the whole conduit  30  emits light so as to render it visible. 
         [0041]    A fluid conveying conduit according to a third embodiment of the invention is designated generally by the reference numeral  40 . The third fluid conveying conduit  40  shares many features with the first and second fluid conveying conduits  10 ,  30 . These common features are designated by the same reference numerals. 
         [0042]    The third medical tube  40  includes a conduit body  12  which defines a medical tube, and may be transparent, translucent or opaque. 
         [0043]    An ink  42  which includes a luminescent pigment (not shown) lies on the outer surface  20  of the conduit body  12 . The ink  42  is arranged as a graphic symbol which assists a user or carer in identifying the fluid being carried by the conduit  40 . In the example shown, the graphic “O 2 ” is printed on the outer surface  20 . Other embodiments may include different graphics and/or arrangements of ink  42 . 
         [0044]    In a low light condition, the ink  42  glows, thereby allowing a user or carer to see the conduit  40  as well as readily identify the contents, i.e. oxygen. 
         [0045]    A fluid conveying conduit according to a fourth embodiment of the invention is designated generally by the reference numeral  50 . The fourth fluid conveying conduit  50  shares many features with the first, second and third fluid conveying conduits  10 ,  30 ,  40 . These common features are designated by the same reference numerals. 
         [0046]    The fourth medical tube  50  includes a conduit body  12  which defines a medical tube, and is transparent. In other embodiments, the conduit body  12  may be translucent or opaque. 
         [0047]    The conduit body  12  includes two luminescent markers  14 , each of which includes an elongate, luminescent band  52 ,  54  that lies within the conduit body  12  and extends along the length thereof, as shown in  FIG. 5 . Each elongate band  52 ,  54  includes a luminescent pigment (not shown). The cross-sectional shape of each elongate band  52 ,  54  may differ from that shown in  FIG. 5 . For example, in other embodiments the or each elongate band  52 ,  54  could have a circular, oval, elliptical, oblong or square cross-sectional shape. 
         [0048]    A first elongate band  52  lies completely within the conduit body  12 , whereas one portion of a second elongate band  54  is coterminous with the outer surface  20  of the conduit body  12 . 
         [0049]    In a low light condition, each of the elongate bands  52 ,  54  emits light along substantially the entire length of the conduit body  12 , thereby rendering the whole length of conduit  50  visible. 
         [0050]    A fluid conveying conduit according to a fifth embodiment of the invention (not shown) has a conduit body  12  which defines a medical tube, and includes an antimicrobial additive. In this way the fourth conduit is also able to inhibit the spread of infection within a medical facility or home. 
         [0051]    Whilst the examples described above relate to medical tubing, it is envisaged that the invention could be applied to other fluid conveying conduits such as hoses and pipes.