Needle Tip Guard

Technical Field

This invention relates to a guard for the tip of an intravenous needle and more particularly to a guard which, because of the memory of the material from which the guard is fabricated and the configuration of the needle, automatically covers the tip of the needle following use and cannot be removed without destroying the guard.

Background Art

To help prevent health care workers from becoming infected by hepatitis, AIDS or the like from an accidental needle prick, it would be desirable to have a guard which covers the tip of an intravenous needle after use. Many such guards have been previously disclosed for hypodermic needles and syringes in general, but no guard has yet been revealed specifically for intravenous needles which operates automatically when the needle is withdrawn from the catheter.

Generally one of the first steps of an emergency medical procedure or a surgical operation is to insert a catheter into the patient's vein so that plasma, anesthetics, or other medications may be conveniently administered. Typically, this involves first inserting a needle and plastic catheter combination into the patient and then removing the needle to leave only the plastic catheter in the vein. The possibly contaminated needle must then be further handled and disposed. Obviously it would be desirable to have a guard which would automatically enclose the one sharp end of the needle when it is withdrawn from the catheter, thus preventing the possibility of infection from an accidental needle prick during

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subsequent handling.

Vaillancourt (U.S. Patent No. 4, 725,267) shows some needle guards which protect the end of a needle after use, but they are not entirely automatic since a mechanism must be pushed or turned to initiate their operation. also, they are not intended for use with a catheter.

Jagger, Pearson, Guyenet (U.S. Patent No. 4,781,692) show a novel solution to the intravenous needle problem. In this invention, the needle is withdrawn from the end of the catheter which is in the vein, but remains inside the catheter tubing. Thus, the possibly contaminated needle need not be dealt with and is simply thrown away with the rest of the catheter apparatus after use. However, relative to a simple plastic catheter and fitting currently in use, this leaves a more complex and bulky apparatus attached to the patient which could be very uncomfortable and more difficult to handle. The needle left inside the catheter apparatus can restrict flow of the fluid to the patient.

Disclosure of the Invention

It is an object of this invention to provide a very simple and inexpensive guard for the tip of an intravenous catheter needle which automatically covers this tip and which does not significantly increase the size of the catheter or affect its ease of operation.

It is a further object of this invention to provide a guard for the tip of a catheter needle which operates entirely automatically and thus requires no further action from the operator beyond the normal insertion and withdrawal of the needle.

Yet another object of the present invention is to provide a device which through the physical properties of the guard and the needle configuration automatically covers the needle tip when the needle is

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withdrawn and the guard can only be removed by destroying the guard.

Brief Description of the Drawings Figure 1 shows the needle and catheter in an assembled (pre-application) configuration.

Figure 2 is an enlarged side view of the preferred embodiment of the guard covering the needle tip. Figure 3 is a side view cross-sectional drawing of the needle, catheter and guard together prior to application.

Figure 4 shows the needle with the guard in place at the tip of the needle following removal from the catheter.

Best Mode for Carrying Out the Invention

In Figure 1 the combined needle and catheter assembly is shown as it would normally appear before use. The plastic portion 1 remains with the patient after the needle iε withdrawn and comprises a thin flexible catheter tube 2 and its attached fluid fitting 3. The plastic handle 4 is attached to the needle 5 and is used to remove the needle when the catheter is in place. The distal or sharpened end of the needle 5 can be seen protruding from- the catheter 2 (in this view) which includes a tapered outer end to ease the insertion. The handle and the attached needle are pulled out of the catheter 1 and its fitting after insertion into a vein, leaving the catheter fitting protruding outwardly from the patient.

The preferred embodiment of the guard 6 is shown in Figure 2. Here the guard iε seen in its position over the end of the needle 5 as it would appear after the needle has been withdrawn. In this embodiment, the guard 6 is a hollow cylinder with a split end and rearwardly exrending, slanted overlapping

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end caps or tabs 7. The guard 6 can be made of any suitable material such as metal or plastic which is strong enough to contain the sharp metal needle tip and has memory such that it can spring back substantially to its original shape after the end, which has been flared open by the shaft of the needle prior to insertion, is no longer restricted by the needle. Also to be seen in this view is that the needle end haε a larger diameter or profile forming a shoulder 9. The operating mechanism of the guard 6 can be seen in the cross section of figure 3. Here the guard 6 appears in its position prior to needle withdrawal. A retaining ring 8 is held tightly by a friction fit to the inner surface of the catheter fluid fit ing 3. The outside diameter of the guard 6 is lesε than the inεide diameter of the ring 8 so that normally the guard 6 can easily slide through the ring 8. The needle shaft flares out the end of the guard 6 and the guard 6 is therefore prevented from moving by the retaining ring 8 as the needle is withdrawn. The distal end of the needle 5 is flared out and is slightly larger in diameter or profile than the inside of the guard 6. When the needle 5 is withdrawn and the tip goes inside the guard 6, the guard end caps 7 are free to close. The flared out needle tip shoulder 9 pulls the guard through the retaining ring thus forcing the flared end of the guard closed covering the end of the needle.

It can be noted that the slightly flared needle tip does not hinder insertion into the vein. Positioning the catheter end just behind the shoulder 9 can help eliminate the usual catheter bulge. The needle 5 and the guard 6 are shown after needle withdrawal from the catheter fitting in Figure 4. The guard 6 has been activated automatically by the withdrawal of the needle and cannot be pulled off the end of the needle because of the shoulder and the guard cannot slide down the shaft or be penetrated by the

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needle tip because the tip is contained by the inwardly slanting and overlapping guard ends 7. What is claimed is:

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