Diabetics, who have to frequently inject themselves with different types of insulin, want to have it confirmed immediately before the injection that the syringe contains the correct type of insulin. A visual confirmation is commonly obtained by the fact that the device has at least one element which is coloured according to a colour code made for the different types of in- sulin.

For sight impaired people a tactile confirmation can be established by providing the device with a relief pattern, which can be felt by a finger.

From US 5,730,292 it is known to provide a vial with a cap on which a relief letter indicates the kind of insulin in the vial. As normal letters may be difficult to differentiate, especially if ones tactile perception is impaired as it often is the case by diabetics, a code comprising a pattern of protrusions and/or depressions may form a better tactile confirmation of the con- tent. WO 99/47062 describes a label which is provided with a pattern of protrusions and de- pressions. The pattern can be varied according to the medicine type it shall make the user aware of. The label is placed on the cap of a vial containing a medicine. When the medicine is sucked from the vial into a syringe the label can be moved from the cap of the vial to the end of the piston rod of the syringe so that the user can feel the pattern immediately before he inject the content of the syringe.

The mentioned tactile coding methods presuppose the existence of an accessible plane area of the order 1/2 cm2 and further it calls for a good tactile perception in the pulp of the finger. At least by some diabetics the latter can not be expected, and where a so-called pen is used, i. e. a syringe which is loaded with a cartridge containing medicine for several injections which medicine can be apportioned in a number of individually set doses, only a minor part of the cartridge is accessible for tactile examination.

It is an objective of the invention to provide a coding with a very little demand of space and which can easily be tactile read even by persons with impaired tactile perception.

This is obtained by a code which is provided as irregularities placed along an edge formed by two surfaces meeting each other under an angle larger than 180° and which can be read by following said edge by a finger nail. When the end of a finger nail is moved along the edged a sequence of irregularities will be clearly felt due to the resistance it exerts to the fur- ther movement of the fingernail along the edge.

The irregularities may preferably be notches cut into the edge mainly perpendicular to this edge, but said irregularities may also be protrusions at the top or near the top of the edge or a mixture of notches and protrusions.

The edge may be the circumferential circular edge formed between a cylindrical surface of a needle hub receiving stud on a syringe and the end surface of said stud. This way the code according to the invention can be used on a refilled syringe.

In some syringes designed to receive a changeable cartridge the needle-receiving stud is mounted on and changed with the cartridge. By such syringes the marking is following the cartridge so that the code tells the user what kind of medicine the cartridge contents and when the cartridge is mounted in a syringe the code tells what kind of medicine is in the sy- ringe.

The code may contain a certain sequence of irregularities, projections and recesses, which sequence defines a start point for the code. This is especially appropriate where the edge carrying the code is a circumferential one.

In the following the invention is described in further details with references to the drawing, wherein, Figure 1 shows a sectional view of an end of a syringe with a cartridge car- rying a needle hub receiving code top, Figure 2 shows a sectional view of a code top code marked according to the invention, Figure 3 shows a possible coding on an edge of a code top,

Figure 4 shows the topography met by a finger nail which follows the edge according to claim 3 to read the code, Figure 5 shows another possible coding of a code top, Figure 6 shows a possible topography met by a fingernail which follows the edge according to figure 5, Figure 7 shows still another possible coding of a code top, and Figure 8 shows a possible topography met by a finger nail when following part of the edge in figure 7.

Figure 1 shows a sectional view of an end of a syringe 1 wherein a cartridge 2 carrying a code top 3 is mounted so that a part of the code top 3 projects from the syringe and forms a stud on which a needle hub 4 can be received so that a needle 5 penetrates a rubber mem- brane 6 closing the cartridge 2.

Figure 2 shows a sectional view of the code top 3, which has a cylindrical surface, provided with a thread 7 onto which the needle hub 4 can be screwed. A notch 8 in an edge 9, formed where the cylindrical surface and an end surface of the code top meet, can have the charac- ter of a short radial recess 8 in the annular end surface 10 of the code top 3.

Figure 3 shows a possible coding provided at an edge of a needle receiving stud. Figure 4 shows schematically the topography which a finger nail meets when it follows the edge. First a lowering of the edge starts at 11. Thereafter a pair of irregularities 12 is met having the shape of two consecutive protrusions.

Figure 5 and 7 shows other possible codings with a number of irregularities 12 distributed along the perimeter of the code carrying edge. Figure 6 and 8 shows different topographies illustrating that the irregularities 12 met by the reading fingernail may be as well ridges as recesses. A start point can be defined by a certain sequence of projections and notches.

A coding as dense as one irregularity per mm. can easily be read.

Although the invention is main explained with reference to a code top which forms a needle receiving stud other placements of the edge carrying the code lies within the scope of the invention. E. g the code carrying edge can be an edge elsewhere on a syringe or cartridge or another device containing a medicine. The medicine do not necessarily have to be insulin although the invention is mainly described by emphasising the advantages the coding ac- cording to the invention offers diabetics.

Although the coding is shown and described as being carried by a circumferential edge cod- ing along a linear or curved edge is within the scope of this application.