Protective device for a hypodermic needle

The invention relates to a protective device for an injection or infusion needle according to the preamble of claim 1.

An apparatus of this type is known from WO-A-99/08742, wherein the handle part is formed by a hollow catheter hub, the distal end of which is connected to a catheter. The opposed spring arms of the guard member engage with grooves on the catheter hub and are retained within the catheter hub until the needle is retracted so far that the needle tip comes to lie behind the angled ends of the spring arms whereupon the spring arms disengage from the catheter hub and cover the needle tip. The needle with protective element is then completely detached from the catheter shoulder, the protective element being exposed at the needle tip.

US Pat. No. 5,344,408 describes a protective device for an injection needle with an inner sleeve surrounding the needle as a protective element and an outer sleeve as a handle part detachably connected to the protective element so that the outer sleeve can detach itself from the protective element in the distal direction.

A further protective device is known from US Pat. No. 4,929,241 wherein a relatively small protective element is arranged on the needle which can be displaced by means of a spring from the retracted position into the protective position at the needle tip, wherein elastic arms of the protective element overlap the needle tip, An engagement device on the protective element holds this on the needle shaft. Because of the small size of the guard member, it is difficult to move it manually on the needle. Furthermore, the fastening spring can not be released until the needle tip is exposed, so that a risk of injury can not be excluded.

The invention is based on the object of designing a protective device of the type indicated at the outset in such a way that actuation by hand is facilitated and a risk of injury can be excluded.

This object is achieved according to the invention by the features of claim 1. By providing a handle part for displacing the protective element, when the needle is retracted by means of the needle holder after an injection with the other hand, the handle part can be held comfortably such that the protective element moves between the needle and the handle part into the protection position at the needle tip Without having to touch the small protective element with the fingers. Due to the fact that the protective element is brought into the protective position during the withdrawal of the needle, a risk of injury can also be excluded.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawings. Show it<dl id="dl0001" compact="compact"><dt>FIG</dt><dd>In a longitudinal section a protective device,</dd><dt>FIG</dt><dd>2 shows a side view of the embodiment according to FIG</dd><dt>FIG</dt><dd>1 shows a view of the device according to FIGS. 1 and 2 with a protective element shifted into the protective position, FIG.</dd><dt>FIG</dt><dd>A modified embodiment of the device, and FIG</dd><dt>FIG</dt><dd>7 is a sectional view through another embodiment with a curved needle.</dd></dl>

1 shows a needle holder 1 in which a needle 2 is attached. A protective element 3 in the form of a spring clip with intersecting arms is arranged on the shaft of the needle 2. Reference numeral 4 denotes a sleeve which is displaceable with the protective element 3 along the needle shaft. In the illustrated embodiment, the tip 5 of the needle is curved according to an epidural needle or a Huber needle, so that the sleeve 4, which has a smaller diameter than the curvature at the needle tip, and with it the protective element 3 does not extend over the Needle tip.

Between the needle holder 1 and the protective element 3, a handle part 6 is arranged, which has a hollow-cylindrical section 7 at the proximal end, on which a radially protruding shield 8 is formed. On the front side of the shield 8 is formed a cylindrical section 9 whose distal end is hollow. In the cavity 10, the protective element 3 is arranged in the provision according to FIG. 1, which can be displaced forward by the displacement of the handle part 6 to the needle tip 5 while the needle holder 1 is held with the other hand. In this case, the angled ends of the crossing arms of the protective element 3 overlap the needle tip 5, so that injury to the operator is prevented by the needle tip.

The needle holder 1 has radially projecting ribs 11 on the distal end, on which the hollow-cylindrical section 7 of the handle part 6 is guided. Between the cylindrical section 9 with a smaller outer diameter and the hollow cylindrical section 7 with a larger outer diameter, slots 12 are formed in the handle part 6, through which the front ends of the ribs 11 of the needle holder 1 protrude radially, as shown in FIG.

The cylindrical section 9 of the handle part 6, which is provided with the cavity 10, has a fully cylindrical section 14 between the slots 12 and the cavity 10, in the center bore of which the needle 2 is guided. Between the slots 12 of the handle part 6, the cylindrical section 9 is integrally connected by means of webs 15 with the shield 8 or the hollow-acrylic section 7.

These ribs 11 projecting beyond the outer circumference of the cylindrical section 9 of the handle part 6 serve to attach a needle cap. This needle cap is used for storage and handling of the device. It can be withdrawn from the needle holder 1 immediately before use of the injection needle in order to release the needle without moving the handle part 6 and the protective element 3 because the needle cap is held by the ribs 11 at a radial distance from the section 9 of the handle part 6 becomes.

Because of the smaller diameter at the portion 14 opposite the larger diameter at the ribs 11, the needle cap, which consists of a tube of uniformly uniform diameter, can not be mis-positioned on the portion 14, but can only be placed on the ribs 11. This prevents the needle cap from being engaged with a portion of the handle portion 6 unintentionally. The needle cap can be made inexpensively by extruding a tube, a piece of such a tube forming the needle cap.

After removal of the needle cap, an injection can be carried out in the provision according to FIGS. 1 and 2, whereupon the gripping part 6 is held at the portion 7 when the needle is held with one hand on the needle holder 1 with the other hand so that the relative movement between Handle part 6 and needle 2, the protective element 3 is displaced into the protective position at the needle tip. This extended position of the handle part 6 is reproduced in FIG.

The protective element 3 is loosely arranged in the cavity 10 of the handle part 6 so that the handle part 6 can be easily retracted from the position in FIG. 3 while the protective element remains in the protective position at the needle tip. The cavity 10 in the cylindrical section 9 protects the protective element 3 after removal of the needle cap.

1 and 2, the hollow cylindrical portion 7 on the handle portion 6 serves to protect the fingers of the hand holding the handle portion from contact with the needle shaft when the needle is retracted. In another embodiment of the needle holder 1, this hollow-cylindrical section 7 can be made enlarged behind the shield 8.

Like the needle holder 1, the handle part 6 is expediently made of plastic.

FIG. 4 shows a modified embodiment of a handle part 6 in conjunction with a syringe 16 on which an injection needle 2 is fixedly attached by means of a needle holder 17, which is designed as a cannula lug. In this embodiment, a bead 18 is formed in front of the needle tip on the outer circumference of the needle, against which the rear wall of the protective element 3 comes to rest in the protective position. Instead of a bead 18, diametrically opposite knot-like projections can also be formed by means of a needle punching.

The handle part 6 has a cylindrical section 19, which is guided on the needle holder 17 in the initial position according to FIG. Two brackets 20 extend from this cylindrical section 19 at diametrically opposite locations in the illustrated embodiment, at a distance from the circumference of the syringe in the proximal direction. The ends of these brackets 20 are formed on an annular body 21, from which elastic fingers 22 extend radially inwards. The free ends of these elastic fingers 22 rest on the outer circumference of the syringe 16.

Due to the elastic fingers 22 between the handle part 6 and the outer circumference of the syringe 16, the handle part 6 can be used for differently sized syringe diameters. For example, syringes with a volume of 1 ml to 10 ml can be used in the same handle part. This allows a wide range of syringes that can be used with the same needle.

4, radially projecting ribs 11, which serve as a seat for a needle cap, are formed at the front end of the needle holder configured as a cannula shoulder. The protective element 3, whose rear wall protrudes beyond the cross-section of the ribs 11, is displaced forwardly into the protective position by the inner circumference of the cylindrical section 19.

A further cylindrical section 9 is formed on the cylindrical section 19, in the cavity 10 of which the protective element 3 is received. As in the embodiment according to FIGS. 1 and 2, two axially extending slots are formed between the two cylindrical sections 19 and the section 9, through which the ribs 11 formed on the needle holder or cannula projection 17 project to receive the needle cap 13.

4 shows a perspective view of a needle cap 50 formed by injection molding, the distal end of which can be closed, while the proximal end on the inner circumference has grooves or grooves 51 corresponding to the number of ribs 11, which, when the needle cap 17 is plugged onto the needle holder 17, The ribs 11 engage so that the needle holder 17 can also be rotated by rotating the inserted needle cap 50. A threaded engagement is usually provided between the needle holder 17 and the syringe 16 so that the needle holder 17 can be screwed onto the syringe 16 by twisting the needle cap 50.

It is common to draw liquid into the syringe by means of a relatively large diameter needle and then to replace the needle with a relatively small diameter needle to perform an infusion to the patient. In the embodiment shown in FIG. 4, the needle can easily be replaced. The described embodiment allows an actuation by one hand when the syringe contents are injected, the syringe 16 being held with two fingers and the needle being pulled out of the patient's skin, while at the same time a finger of the hand on the proximal end of the annular body 21 Is supported.

FIG. 5 shows an embodiment in conjunction with a Huber needle 2, which is held in a needle holder 1 'by means of a bent-away portion and is provided for vertical injection during injection. Reference numeral 30 denotes a support part, which preferably consists of foam material, Adhesive surface for better fixation on the skin of the patient. Disposed between the support part 30 and the needle holder 1 'is a shield-shaped handle part 6 which rests on the support part 30 via a flange-like region 31 and extends over a pot-shaped middle section 32 into a corresponding recess of the needle holder 1'. The protective element 3 is arranged in this cup-shaped middle part 32.

When the needle is pulled out, the handle part 6 is held on the support part 30 while the needle holder 1 'is withdrawn. The protective element 3 is displaced towards the needle tip until it comes into contact with the needle crank 18, while at the same time the two crossing arms of the protective element 3 overlap and cover the needle tip. The handle part 6 can then be removed from the support part 30 or together with the support part 30. The handle part 6 and the support part 30 can also be connected to one another via an adhesive layer.

The side walls of the cup-shaped middle part 32 are preferably inclined in a conical manner so that the handle part 6 itself can not be pulled off, but can only be pressed.

5 shows a nacelle cap, 13 'with a tubular section, at the proximal end of which diametrically opposite wall sections 33 protrude, which are inserted into the needle holder 1' via correspondingly circular grooves 34 in the flange 31 of the handle part 6. The curved wall sections 33 are guided loosely through the curved slots 34 in the flange 31 of the handle part 6 and are press-fitted into the grooves 35 of the needle holder 1 '.

The needle cap 13 'in FIG. 5 can be closed on the distal side.

In all embodiments, the protective element 3 is preferably a metal needle clip, the crossing arms of which extend from opposite sides of a proximal wall section which has a hole for the passage of the needle, the hole diameter being less than the maximum transverse dimension of the needle at the pinch 18 so that the needle clip is held at the needle tip by the enlarged diameter portion 18 in the protective position. The intersecting arms, which extend on either side of the needle 2, have at the distal end an end section which is approximately widened to the width of the rear wall and rests in the initial position on the outer circumference of the needle under elastic pretension and upon reaching the needle tip by spring action into the protective position In which the two widened end sections overlap the needle tip. For this purpose, the distal ends of the arms, as the side views show, are slightly displaced in the longitudinal direction relative to one another or the arms have different lengths so that it is ensured that the two angled end sections of the arms overlap the needle tip. At least on the longer arm, the end portion is bent inwards at the free edge to ensure the cover of the needle tip even if an attempt should be made to push the needle clip back out of the protective position on the needle, the inwardly bent end portion catching on the needle tip . The needle clip can overall be very compact and only about 7 mm long.