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 . a fluid conveying conduit according to a first embodiment of the invention is designated generally by the reference numeral 10 , as shown in fig1 . 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 . in the embodiment shown , all three elongate ribs 16 lie adjacent to an inner surface 18 of the conduit body 12 , as shown in fig4 . 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 . 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 . in the embodiment shown in fig1 , 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 . 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 . 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 . 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 . 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 . 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 . 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 . the third medical tube 40 includes a conduit body 12 which defines a medical tube , and may be transparent , translucent or opaque . 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 . 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 . 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 . 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 . 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 fig5 . 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 fig5 . for example , in other embodiments the or each elongate band 52 , 54 could have a circular , oval , elliptical , oblong or square cross - sectional shape . 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 . 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 . 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 . 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 .
a fluid - containing conduit including at least one luminescent marker 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 containing luminescent material along interior wall surface , or may be elongate luminescent bands adjacent the exterior wall of the conduit , or may be indicia containing luminescent material such as ink .