Needle Guard

Abstract

A catheter needle guard unit having a hub with a cannula needle affixed therein to form a passageway through the hub and cannula, said needle being pointed at the distal end, and a needle guard means having a sleeve member with a longitudinal slot adapted to snap over the entire length of the needle in snug relationship therewith to form a protective closure over the point of the needle when in the closed position and swingably fastened to the hub through an intermediate flexible connecting section.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation-in-part of application Ser. No. 768,017, filed Oct. 16, 1968, now abandoned.

Description

This invention relates to an improved catheter needle guard unit and to a method of making the unit. More particularly, the invention is broadly directed to the post-injection protection of catheter needles used to make entry in the body of a patient for the placement of a catheter through a cannula.

In the administration of parenteral fluids, it is now common practice to make a venipuncture with a needle and then thread a sterile plastic catheter in the vein. This catheter is light in weight, flexible and can be taped to the patient's arm to remain in place as long as desired without causing the patient any appreciable discomfort. This so-called "indwelling" catheter is exemplified by the device disclosed in U.S. Pat. No. 3,335,723.

In such administration procedure, it is virtually impossible to remove the needle unless it contains a slot therein, and many surgeons prefer a needle without a slot. The needle must, therefore, remain around the catheter adjacent the patient's body as long as the catheter remains in place. It is important in such procedure that the needle be immobilized to prevent its puncturing of the patient's skin or cutting of the catheter. It has been customary heretofore to use adhesive tape, gauze padding and the like material to wrap the needle point for this purpose.

Recently, in U.S. Pat. Nos. 3,323,523 and 3,324,853, various needle protective devices have been suggested for catheter needles of the indwelling type catheter unit. While these devices are useful, they are not without disadvantages insofar as they possess somewhat intricate structures and are difficult to manipulate.

Other needle protective devices, such as the needle cap described in U.S. Pat. No. 2,711,732 and the syringe shield as disclosed in British Pat. No. 9700, A.D. 1902, while somewhat suitable as protective covers prior to needle injection of hypodermic type syringes, are not suitable for immobilization of a catheter needle after placement of the catheter and withdrawal of the needle from the patient.

Accordingly, it is an object of the present invention to provide an improved catheter needle guard unit.

It is another object of this invention to provide a method of making an improved catheter needle guard unit.

These and other objects will be apparent to the person skilled in the art after reading the specification and claims hereof.

Briefly stated, the catheter needle guard unit of this invention comprises a hub having a cannula needle affixed therein to form a passageway through the hub and cannula, said needle being pointed at the distal end, and a needle guard means comprising an elongated flexible plastic sleeve member with a longitudinal slot adapted to frictionally snap over the entire length of the needle in a relatively immobile or snug relationship therewith and thereby form a protective closure over the point of the needle when in the closed position and swingably fastened to the hub through an intermediate flexible plastic connecting section. This guard unit can be readily fabricated as hereinafter described. It is convenient to use in practice insofar as it is affixed to the hub of the cannula and can be conveniently snapped into place over the entire length of the needle after the needle is withdrawn from the patient following venipuncture.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter regarded as forming the present invention, it is believed that the invention will be better understood from the following exemplary description taken in connection with the accompanying drawings in which:

FIG. 1 is a side elevational view embodying principles of the catheter needle guard unit of the present invention.

FIG. 2 is a front elevational view of the needle guard of FIG. 1.

FIG. 3 is a transverse sectional view of the needle guard taken along the lines 3--3 of FIG. 2.

FIG. 4 is a side elevational view showing the needle guard of FIG. 1 in the closed position.

Referring now to the drawings and particularly to FIG. 1, the reference numeral 20 is used to indicate generally the hub of a cannula having a bore therethrough which can be adapted for fluid communication with any conventional parenteral fluid administration source at extremity 21. Cannula hub 20 preferably has a reduced section or nipple 22. A cannula needle 23 with a pointed distal end 24 for venipuncture is in axial alignment and fluid-tight engagement with cannula hub 20. Needle guard 25 is composed of a sleeve 26 with a longitudinal slot 27 adapted to frictionally snap over and snugly fit needle 23 to immobilize the needle and provide a protective closure therefor when in the closed position, a collar 28 for convenient mounting to the nipple 22 of cannula hub 20 and a flexible plastic connecting section 29 intermediate to collar 28 and sleeve 26 for swingable movement of said sleeve 26 in an open and closed position. Sleeve 26 is of sufficient size, primarily in thickness and width, to maintain its open or closed position until the application of slight forces such as by manual operation.

FIGS. 2-4 show the needle guard 25. FIG. 2 shows the cross-section of sleeve 26 and collar 28. Sleeve 26 preferably is constructed of a pliable or flexible plastic material with a horseshoe-shaped cross section for convenient snapping over needle 23 and for retention and immobilization of the needle when in the closed position. Slot 27 preferably has a normal cross-sectional diameter or width at its opening which is slightly less than the diameter of needle 23 to facilitate this snapping action and immobilization. Collar 28 preferably is of a ring-like structure for convenience in manufacture and ready mounting to the nipple 22 of cannula hub 20. FIGS. 3 and 4, in particular, illustrate the flexibility of flexible connecting section 29 which is straight in FIG. 3 and curved in a slightly bulbous manner in FIG. 4.

In operation of the catheter needle guard unit, needle guard 25 is in the open position when needle 23 is used to make a venipuncture in the patient and readily snapped into the closed position manually by a finger of the operator after placement of the catheter in the patient and withdrawal of needle 23. In this closed position, needle 23 will be immobilized to prevent its puncturing of the patient's skin or cutting of the catheter. The catheter needle guard unit can be employed in practice as a subcomponent for a complete indwelling catheter device for the administration of parenteral fluids such as described, for example, in U.S. Pat. No. 3,335,723 . When not in use, the needle guard can be in the closed position to protect needle 23 from damage, if desired.

The catheter needle guard unit of the present invention is preferably constructed in the manner illustrated in the attached drawings not only for the above described convenience of operation in practice but also for convenience in production. A preferred method of making this catheter needle guard unit comprises the heat sealing of an extruded flexible, slotted sleeve 26, having a pre-cut flexible connecting section 29, to a flexible ring-like collar 28 cut from a piece of tubing and then solvent sealing said collar 28 to the reduced section 22 of cannula hub 20. For this purpose, the flexible, slotted sleeve 26 and the tubing for collar 28 can be conveniently made from a pliable or flexible vinyl plastic such as, for example, plasticized polyvinyl chloride, copolymers of vinyl chloride and vinylidine chloride, copolymers of vinyl chloride and vinyl acetate, polyvinyl acetate and the like flexible resins, whereas the cannula hub can be conveniently made of a relatively more rigid plastic such as, for example, polystyrene, copolymers of polystyrene and butadiene, and other rigid, solvent-sealable plastics.

It will be apparent that many modifications and variations can be made to the particular embodiments of the invention described hereinbefore. For example, the needle guard 25 can be fastened directly to the cannula hub 20 or its reduced section 22 without use of a collar 28. Also, cannula hub 20 and needle guard 25 can be fabricated as a single piece, for example, by injection molding of a suitable plastic resin such as polypropylene or polyethylene. The cross section of sleeve 26 can be U-shaped instead of horseshoe-shaped, although the latter shape is preferred for its better retention of needle 23 when needle guard 25 is in a closed position. The thickness and width of sleeve 26 can vary somewhat, depending in part upon the material of manufacture. Instead of being ring-like, collar 28 can be triangular, square, or polygonal in cross-sectional shape, generally depending upon the corresponding shape of reduced section 22 of cannula hub 20. Collar 28 can also be butted directly to cannula hub 20 instead of along the length of nipple 22. Cannula needle 23 can be positioned in any desired orientation about its 360.degree. axis. Of course, many variants in materials of manufacture will also be apparent to the person skilled in the art.

Still other modifications and variations can be devised by the person skilled in the art after reading the specification and claims hereof without departing from the spirit and scope of the invention defined herein. All such further modifications and variations are included within the scope of the invention as defined in the appended claims.

Claims

What is claimed is:

1. A catheter needle guard unit comprising a hub having a cannula needle affixed therein to form a passageway through the hub and cannula, said needle being pointed at the distal end, and a needle guard means comprising a flexible plastic sleeve member with a longitudinal slot having a normal cross-sectional diameter less than the diameter of said needle and adapter to frictionally snap over the entire length of the needle in a relatively immobile relationship therewith and thereby form a protective closure over the point of the needle when in the closed position following placement of the catheter and withdrawal of the needle and swingably fastened to the hub through an intermediate flexible plastic connecting section.

2. A catheter needle guard unit in accordance with claim 1 wherein the needle guard means includes a collar for fastening to the hub.

3. A catheter needle guard unit in accordance with claim 1 wherein the sleeve member is an extruded, flexible plastic sleeve with a horseshoe-shaped cross section and wherein the flexible plastic connecting section is pre-cut from, and part of, said extrusion.

4. A catheter needle guard unit in accordance with claim 3 wherein the needle guard means includes a flexible plastic ring-like collar for fastening to the hub.