The invention relates to an infusion cannula having wings for fastening to a patient and at least one valve stub forming an injection channel with a valve cap being rotably around two pivots extending in continuation of each other perpendicular to a plan being defined by the longitudinal axis-ses of the cannula and the valve stub, whereby, through the valve stub, injections can be made into the patient during the infusion.

Such an infusion cannula is known from US Patent 3,802,433, where the valve stub is arranged diametrically opposed to the wings, which provide a support surface to the patient, and which serve to the fastening to the patient. This results in the valve stub and it's cap protruding from the infusion cannula, whereby the valve cap at the movements of the patient can be pushed off with a contamination as a result. Further such infusion cannula requires a pull perpendicular to the logitudinal direction of the infusion cannula using two hands, when the cap is removed during the preparation of an injection, as, during the removal of the cap, for the patient's sake or eventually a loosening of the cannula, the cannula should be held back.

From DE Publication 26 01 993 an infusion cannula with a sock- et case is known, to which, supposedly through a cone, a connecting piece is fastened being equipped with a transverse valva stub. This valve stub is upwardly open, and so it is easily contaminated.

An infusion cannula is known from the DE Publication No. 30 31 242, where the valve stub er provided with a cap, which is hinged along the one side of the valve stub. For the opening of this cap it is necessary exert a pull perpendicular to the logitudinal direc¬ tion of the cannula, which either causes inconveniences to the patient in the form of pain, or two hands are required for handling the cap. This infusion cannula is not secure from the cap being pushed off as a result of the patient's movements, and so, also here, there is an un¬ acceptable large risk for a contamination of the injection channel.

In the following, at the disclosure of the infusion cannula, the term 'proximal' is used, which in relation to the infusion cannula means that part of the infusion cannula, which at normal use, is clos- est to the operational staff, whereas the opposite end of the infusion cannula is referred to as the 'distal' end. This means, at the introduc¬ tion of an infusion cannula into a patient, that coupling means will be

in the proximal end of the infusion cannula, whereas the point of the infusion cannula constitutes the distal end.

Infusion cannulas are intended for use at infusion of fluid into patients. To this purpose a hypodermic needle is put on the distal end of the infusion cannula, which can be equipped with a soft cover. After the puncture of skin and vein the needle can be pulled out again, whereupon the soft cover stays embedded in the vein. The in¬ fusion cannula is fixed to the skin through the wings, and containers with the infusion fluid is connected to the proximal end of the infu- sion cannula.

If medicin is to be administered or if a physical examination shall be made, during which contrast substances or sedating compo¬ sitions are to be injected or the like, it is desirable, because of the pa¬ tient, to avoid further inconveniences caused by introducing hypo- dermic needles. To this purpose, the valve stub fixed to the infusion cannula is used, whereby the valve stub can be constructed as a valve stub known from the state of the art, eventually with a cap and a not shown membrane or the like means in order to prevent leakage of the infusion fluid through the valve stub. The infusion cannula is usually fastened to the back of the hand, where it is easily accessible for the nursing staff. If the patient's hand or arm are not fixed, the infusion cannula on the back of the hand is, however, ex¬ posed to collisions with various hard objects in the proximity of the patient. In that way there is a risk, that the patient pushes off the valve cap from the valve stub, and there is a risk for a comtamina- tion of the interior of the valve stub.

To infusion cannulas being designed as mentioned above there is connected that considerable drawback, that it is not possible to prepare an injection through the infusion cannula by the use of only one hand. This is, however, desirable for the nursing staff, as an in¬ jection should be given immediately after the filling of the syringe without having to put the syringe away during the preparation of the injection through the infusion cannula causing a risk for comta- mination of the injection cannula being introduced in the infusion cannula fixed to the patient. Further, those infusion cannulas being equipped with a cap are not sufficiently secured against an uninten¬ ded opening of the cap . caused by the movements of the patient, what increases the risk for contamination of the injection channel.

An object for_ the present invention is consequently to secure an one hand operation of the cap on the valve stub securing the cap against unintended opening.

This is accomplished according to the invention in an infusion cannula as mentioned above by having the turning axises of the valve cap being arranged on the infusion cannula on a level with the valve stub, and the valve cap having a skirt surrounding the valve stub having a height approximately corresponding the height of the valve stub and having an opening on the proximal side being so di- mensioned, that the valve stub can pass through it, when the valve cap is rotated, and the skirt on the sides of the valve cap having ex¬ tensions reaching down past the side of the valve stub to proximal part of the infusion cannula, whereby the extensions are provided with bearings for the turning axis, and by having the proximal part of the infusion cannula relative to the wings being in a manner per se rotably around the longitudinal axis of the cannula to a position, where the valve cap is lying adjecent to one of the wings.

With the arrangement according to the invention a possibility for a single hand operation of the valve cap by injections is provided, and also the valve cap is secured against unintended opening, when the valve stub is turned down against the patient, whereby turning the valve cap is prevented by the one wing on the stationary part of the infusion cannula, as the turning movement og the cap around the axis is blocked by the wing. For opening the infusion cannula the operational staff just have to turn the infusion cammula around its longitudinal axis and swing back the valve cap distally in relation to the valve stub.

In an advangeous improvement of the infusion cannula accord¬ ing to the invention the skirt on its inside is provided with at least one protrusion, which, in the closed position of the cap, is positioned adjacent to the surface of the valve stub proximally to the longitudi¬ nal axis of the valve stub. In this way a dual snap-function is achie¬ ved, thereby securing that the valve cap is not freely pivotal in any of the extreme positions, as the protrusion in the other extreme posi- tion of the cap, the open one, is moved correspondingly to the other side of the surface of the valve cap distally . in relation to the longi¬ tudinal axis of the valve stub.

A further advantageous improvement of the infusion cannula according to the invention is achieved by the distal part of the skirt having a length adapted to the deflection angle, whereby the skirt at deflection is positioned adjacent to the infusion cannula with a tread surface, thereby forming a stop for the turning movement. To this purpose the tread surface is formed as an oblique edge. Through this elaboration a well defined turn around the spindle is secured, what is lightening the handling of the infusion cannula.

Further advantages of the infusion cannula according to the in- vention is explained in the following description with reference to the drawing. In the drawing the

fig. 1 shows a perspective view of the infusion cannula ac¬ cording to the invention with a closed valve cap and upright valve stub, fig. 2 the infusion cannula as in fig. 1, but with an opened valve cap, fig. 3 the infusion cannula as in fig. 1, but with a valve stub lying down, fig. 4 a view of the infusion cannula as seen from the proxi¬ mal end with closed valve cap and upright valve stub and the lying valve stub indicated with dot-and-dash lines, fig. 5 a longitudinal section of the infusion cannula according to the invention, where the valve cap is shown in its two extreme positions, the open one with dot-and-dash lines, and fig. 6 a cross section according to the line A - A in fig. 5 through the valve stub and the valve cap on the infu- sion cannula according to the invention.

The infusion cannula 1 shown in fig. 1 is equipped with wings for the fastening onto the patient. The proximal part of the infusion cannula 1 is pivotably inerted in the distal part with the wings 2. The valve cap 4, which is shown in a closed position (pos. 1) is posi¬ tioned around the spindle 5 with holes 9 serving as bearings. The valve stub 3 is just visible.

Fig. 2 shows the infusion cannula 1 with an open valve cap 4. By this there is opned for the injection syringe, which shall be introdu¬ ced through the injection channel in the valve stub 3. In the open position (pos. 2) of the valve cap 4 it is treading with its tread sur- face 11 on the distal part of the cannula, onto which the wings 2 are fastened. The opening of the valve cap by the nursing staff can be achieved through the use of just one hand, whereby the valve cap 4 can be removed by pushing with one finger, while the rest of the hand keeps the infusion cannula itself so that no pulling or an unne- cessary large pressure appears on it.

If medicin is to be administered to or examination shall be made on the patient, during which examinations contrast substances or sedating drugs or the like shall be injected, it is possible, in consi¬ deration for the patient, to avoid further inconveniences by introduc- ing cannulas, as the nursing staff can use the valve stub 3 fastened to the infusion cannula. The injection channel and the valve mecan- isms placed therein shall not be mentioned more explicitly here.

As the infusion cannula 1 generally is fastened to the backside of the patient's hand, where it is easily accessible for the nursing staff, the infusion cannula on the backside of the hand is exposed, if the patient's hand or arm is not fixed, to collisions with various hard objects in the proximity of the patient, whereby there is a risk, that the valve cap 4 is pushed off from the valve stub 3 with a comtami- nation of the interior of the valve stub 3 as a result. In the position of the infusion cannula shown in fig. 3 in pos. 3_ the valve cap 4 is practically locked in its closed position, whereby security has been established, thaht the injection channel is not con¬ taminated.

Fig. 4 shows the infusion cannula 1 as seen from the proximal end, whereby it is made clear, how the protrusions 10 work together with the surface of the valve stub 3. Here it is seen, that the protru¬ sions should not be so large, that they, at the pivotal movement of the valve cap, are lifting off the extensions 8 with the holes 9 out of intervention with the spindle 5. Further, it is seen, how the valve stub 3 with the valve cap 4 can be laid down to pos. 3_ against that part of the body, where the infusion cannula is fastened. It can thereby be seen, that the height of the infusion cannula is reduced considerably, whereby the risk of

collision between the valve stub and hard objects in the proximity of the patient - and therewith the risk for an unintended removal of the valve cap 4 - is reduced drastically. It is indicated, that the valve stub 3 can be turned down to both sides, as the intended function is achieved on both sides.

In fig. 5 a sectional view of the infusion cannula according to the invention is depicted, whereby the turning movement of the valve cap 4 is indicated. In order to ease the operation of the valve

^• cap 4 it is, on the upper side, shaped with an in itself known depres- sion 13, whereby a good hold for a single finger is secured.

For further securing of this hold in the depression grooves 12 are placed therein streching out parallel with the turning spindle 5. On the dot-and-dash shown part of the valve cap 4 it is visible, that the length λ of the skirt 6 on the distal part of the valve cap 4 is adapted to the turning angle, which here is indicated as 45°, but it could as well be any size, if just, at the turning, an admission is es¬ tablished to the injection channel in the valve stub 3. The under edge of this part of the skirt 6 is here oblique in order to establish a wide tread surface. It can be seen, that the protrusions 10 in the open position of the valve cap 4 are turned to the other side of the longitudinal axis of the valve stub 3, whereby a reliable open position of the valve cap 4 is secured. Thereby further manipulation with the valve cap 4 dur¬ ing the injection is unnecessary, and the nursing staff can without disturbing factors finish the injection and close the valve cap 4 again and turn down the valve stub 3 along the patient's surface.

Fig. 6 indicates a sectional view through the valve stub 3 ac¬ cording to the line A-A in fig. 5. Here it is clearly seen, that the flanks 14 on the skirt 6 of the valve cap 4 are obliquely shaped, so that the flanks 14 can not easily catch e.g. bed linen or the like, whereby, again, a risk for contamination would be present.