WO1990011789A1

WO1990011789A1 - System for securing a needle on a syringe

Info

Publication number: WO1990011789A1
Application number: PCT/FR1990/000260
Authority: WO
Inventors: Philippe Bessis; Pierre Sibuet
Original assignee: Etablissements Anthogyr
Priority date: 1989-04-10
Filing date: 1990-04-10
Publication date: 1990-10-18
Also published as: FR2645444A1

Abstract

The system concerns a 'concept of absolute safety' during disconnection and storage of dental needles on sterilizable capsule-carrier syringes. It consists in: modifying the male threaded end of the syringe on its surface and its length and the addition of a lock to secure the base of the needle to the male end of the syringe during injection. The lock is released with the one hand holding the dental needle. A box is provided for storing used needles and is fixed to a work surface.

Description

NEEDLE LOCKING SYSTEM ON A SYRINGE.

The present invention relates to the system for detaching a contaminated dental needle after injection, and the fixing of which to the body of the syringe is currently done by a thread system (6); such as syringes used in dentistry or veterinary art, distributed, for example, by ANTHOGYR (Figure 1 ..

This syringe consists of a cartridge holder, into which the cartridge of the product to be injected is inserted, and of a piston (2) articulated relative to the body of the syringe (1). The end of the syringe has a male thread allowing the significant attachment of the needle (whose base has a female thread) with the body of the syringe (Figure 1).

This significant connection between the needle and the syringe is necessary due to intraosseous injections and / or hard tissue, in order to avoid the separation of the needle from the syringe during withdrawal of the assembly by the manipulator, at the end of the injection.

This connection is also necessary, due to the high pressure which exists at the base of the needle, during the pushing of the injectable product (a diameter ratio exists between the lumen of the needle and the cartridge of injectable product). We know the principle of separation of the dental needle from the body of the dental syringe:

- either by refitting the protective cap of the needle and unscrewing the needle with the risk of puncture by the operator, during re-capping;

- either by using a Kocher forceps or a needle box to unscrew the needle from the body of the syringe. The latter system is safer but impractical, since it requires the use of both hands of the manipulator.

The present invention allows, after use of the syringe-needle-storage box assembly, the separation of the needle from the body of the syringe (or cartridge holder) without the manipulator having to approach his hand to the needle, using the protective cap or a storage box, held by the second hand, thus exposed, to unscrew the needle (7) from the body of the syringe (fig 2).

The needles (7) used are characterized by the fact that the plastic base (4) (having an internal thread), is located between the two metal ends of the "actual needle" (5), in which the product circulates injected (Figure 2); one end piercing the rubber stopper of the cartridge, containing the injected product, the other end coming into contact with the tissue requiring injection.

The majority of needle storage boxes are in the form of a sealed box (Patent no FR-A-2603872) but necessarily requiring the use of both hands of the manipulator, in order to ensure operation, that is to say the opening of the needle access hole in the receptacle box. This box has an advantage by its tightness but a major drawback by the risk of puncture of the hand handling the box; the latter always remaining close to the needle.

It should be noted that systems have already been described for locking hypodermic needles on a syringe, by means of hooks (Patents USA 2870765 - USA 4490142 - USA 2806473}, which have the sole purpose and advantage of allow better securing (of the needle on the syringe) simpler and faster than by means of a thread; but these systems described do not override the risks of contamination by stinging contaminated needles, during their separation and storage; there is no description of means allowing this separation without any risk of puncture.

We note, in the cited Patents:

- The absence of unlocking lever (hooks) located far from the needle, the presence of a non-standard needle, a solidari¬ sation of the needle provided by the spring effect of a hook (of variable resistance and therefore not firm); the latter preventing any introduction of the needle into the opening of a needle storage box (due to the non-erasure of the hook during the release of its elastic stress on the needle);

- The absence of a space provided between the base of the needle and the syringe, allowing the edge of the orifice of a receptacle box to be housed there, in order to allow separation by simple traction. In Patent FR-A-1,113,394, the author describes a non-standard attachment-detachment system with needles, the direction of attachment of which is perpenαicular to the axis of the syringe and not axial (therefore different from the systems currently useful ., in order to avoid contamination (by aspiration phenomenon) of the serine fluid by the liquid present in the lumen of the needle, for the purpose of serial vaccinations.

The system is not applicable to the dental syringe, because currently single-use injectable liquid cartridges are used and it is not possible to apply a lateral interlocking system on dental needles marketed, designed for securing by axial interlocking.

Our present invention therefore makes it possible to obtain a connection and separation and storage of dental needles without any risk of contamination by the user.

The means used to obtain this result are as follows:

1 - Modification of the dental syringe

- The male end (6), usually threaded of the body of the syringe has: either more than a single thread turn (Figure 3); or slight reliefs of all shapes on its surface (Figure 4).

The first solution allows, after fitting the dental needle (7), by a single rotation, its final positioning

REPLACEMENT SHEET on the syringe body 'figure 3].

The second solution makes it possible to obtain the same result by a gentle friction on the male tip ^r S) strewn with small reliefs ^' male emoout of the syringe) ^" Figure 4).

These two methods of attachment make it possible to remove the cap from the dental needle before the injection, without the latter being carried away by the cap.

- the male end (é) of the syringe body also differs from current threaded ends: either by its greater length, allowing the base of the needle not to come into contact with the flat circular end of the body ( cylinder of the syringe); either by the presence of a stop (8) at its base (Figure 5).

The excess length of the male tip (6) of the syringe or the stop (8) placed at the base of the male tip corresopπd to 1 or 2 mm in length (Figure 5).

The two systems thus make it possible to voluntarily leave a space (9) between the base of the needle and the circular flat part of the end of the body of the syringe (1) (FIG. 5).

It is in this space (9) of 1 to 2 mm, that penetrates the edge (10) of the orifice (20) of the needle receptacle box. Thus, by simple traction exerted on the base of the needle (4), the latter detaches from the body of the syringe (1), and falls inside the box (FIG. 6). Of course, this operation is done after the injection.

It should be noted that this space (9) can also be obtained by reducing the length of the base (4) of the female needle (7) (depth of the threaded cavity of the shorter base of the needle 1 to 2 mm).

Likewise, the single thread turn can concern both the thread of the internal part of the base (4) of the needle (7) and the male end (6) of the syringe (FIG. 3).

It should be noted that the base (4) of the needle (7) being made of plastic or slightly deformable material and secured to the tip (6) of the syringe by a single thread, the traction exerted by the handler (once the latch (11) is raised) on the body of the syringe, causes a deformation of the plastic thread of the base (4) of the needle (7) (erasure of the plastic thread) and therefore the separation of the needle-syringe system.

- A locking device (11) of the needle (7) on the male end (6) of the body of the syringe (1); this locking device: either caps the base (4) of the needle; either cooperates with a part of the base (4) of the male (nipple) or female (hole or slot) needle.

This device (11) can be put in the locking position or unlocking with one hand, for example with the thumb.

At no time during unlocking is the only hand used near or exposed to the tip of the soiled dental needle (Figure 6).

EXAMPLE OF IMPLEMENTATION (Figures 7, 8, 9 and 10)

Device pivoting about an axis (12) perpendicular to the axis of the syringe (1) and comprising towards the end (in relation to the tip of the syringe) parts such as hooks (13), which locking position, cover the base (4) of the needle, so that the latter (the needle) (7) is blocked against the base (6) of the syringe.

In the unlocked position, the hooks (13) are (by tilting) put in a position out of the way that the needle (7) must follow to be detached from the syringe, and are completely erased behind the plane vertical space (9) thus allowing the total introduction of the needle into the orifice of a box.

The means for tilting the hooks can be a simple lever (14), integral with the hooks (13) and articulated on the axis (12). The lever (14) may have a shape inscribed in a cylinder, and comprising openings.

An opening (15) allows the syringe body to pass during movement: in the locked position, the syringe body is inside the cylinder; in the unlocked position, the syringe body comes out of the cylinder.

A notch (16) allows passage of the end of the syringe inside the device and, thus, the relative movement of the syringe relative to the cylinder.

A third opening (17) opposite the opening (15) makes it possible to see the level of the injection product in the cartridge (18).

The diameter of the cylinder is very slightly greater than that of the syringe. The relative movements of the syringe with respect to the cylinder are centered on an axis of rotation (12) perpendicular to the axis of the body of the syringe and of the cylinder.

The opening (15) is made by removing half of the cylinder. Possibly, to obtain a locking of the operative device, it is possible, to make the opening (15), to remove a little less than a half-cylinder, so that one obtains a clipping effect of the semi-cylinder on the syringe body (1).

2 - Existence of a storage box for soiled needles, fixed on a work surface (figure 11)

The storage box (40) of soiled dental needles allows the dental needle-dental syringe to be separated, and the needles to be stored without the need to use (and therefore be exposed at any time). risk of being bitten by the contaminated dental needle) a second hand, which would be held in front of the piercing end of the dental needle.

The box (40) (part inseparable from the modification of the tip of the dental syringe, in the "concept of absolute safety", has an inlet opening (20) of the needle always free, thus avoiding the use of a second hand The box is fixed to the work surface (figures 11 and 12).

the access hole 20 is located in a wall of the box and is divided into two parts (FIG. 16):

- A polygonal, semi-circular or circular upper part 30. The diameter of the upper part 30 of the orifice 20 is greater than the diameter of the base of the needle concerned, in order to allow its introduction (FIG. 11);

- A lower part 31 is triangular in shape with a lower apex.

The orifice 20 therefore generally has an inverted pear shape.

The edges of the orifice 31 insinuate during the separation needle-syringe in the space 9 (described above), thus retaining the base 4 of the needle inside the box.

The tightness of the box during its transport (with a view to destroying it and its contents) is ensured:

- Either by a plug or sliding shutter, closing off the orifice 20;

- either by the presence of an automatic return airlock, activated by the tip of the syringe, carrying the needle during introduction of the latter in the orifice 20. The box therefore has an airlock in connection, in its upper part, with the orifice 20 and, in its lower part, with the storage area. The airlock floor consists of movable partitions (contiguous at rest), integral and articulated to the walls of the box. The partitions open under the pressure from top to bottom exerted by the tip of the syringe carrying the dental needle in the storage area, the only hand used exerts a pull separating syringe and needle; the dental needle falls into the storage part of the case and the movable partitions of the airlock, which are no longer subjected to any pressure, return to the initial joined position, thus ensuring the airtightness of the airlock. This automatic return effect is ensured by the watertightness of the material making up the box (thermoformable polymer such as hagenated polymers, polyamides and other plastics).

Thus, in the operation described during all of the steps involved in the separation, only the hand carrying the syringe, and therefore always placed behind the soiled dental needle, is used; the risk of pricking and therefore of contamination (hepatitis B, AIDS ...) is zero, unlike all the techniques of separation of dental needles currently existing. All these different stages represent a "concept of absolute security" of non-contamination, during separation of the dental needle-dental syringe-storage.

The fixing means of the box (40) are multiple: twin scotch ^'face, velcro, screws, mounting base (with clipping of the box on the base), mounting rail; reversible fixing means. OPERATION OF THE "ABSOLUTE SECURITY CONCEPT"

The manipulator, after having filled the body (1) of the ANTHOGYR type cartridge syringe with a cartridge (18) of anesthetic liquid or other substance, fixes a dental needle (7) on the male end (6) of the syringe body (1).

The dental needle is then simply secured by soft friction or by the existence of a turn of screw thread. This light solida¬ rization allows to remove the protective cap from the dental needle without detaching the dental needle (7) from the body of the syringe.

Then, the manipulator completely switches the lock (11) against the body of the syringe (1) and, thus, the hooks (13) are found on either side of the base (4) of the needle. They press on the upper face of the collar (18) with a larger diameter of the base (4) of the needle, and prevent any movement of translation of the latter relative to the body of the syringe (1) (FIG. 8 ).

The locking system is thus armed.

Due to the difference in length between the male tip (6) of the syringe and the depth of the female base of the dental needle there is a space (9) of a few millimeters between the base (4) of the needle and the circular flat end (19) of the syringe body (1).

The lock (11) being armed, it follows the shape of the body of the syringe (1) and thus reduces the size of the system during the injection.

After the injection, the manipulator unlocks, with the thumb of the hand carrying the syringe, thus releasing the base (4) of the needle from the hooks (13) which enclose it and allowing the movement of translation of the needle.

The manipulator then introduces the needle (7) to its base (4) in the free orifice (20) of the box (40) needle receptacle. The edge (10) of the orifice 31 of the box being thin enough to fit in the space (9) created between the base of the needle (4) and the planar circular face (19) constituting the end of the syringe body (1).

After this maneuver, the manipulator exerts a traction (23) in the axis (FIG. 6) of the syringe (1) on the body (1) of the latter. Due to the weak connection between the dental needle (7) (gentle friction or engagement in a turn of slightly marked thread) and the male tip (6) of the syringe, the needle (7) falls into the box attached to the worktop.

The manipulator was thus able, without any risk of pricking with the contaminated dental needle (7), to throw the latter in the box (40) away from any contamination.

It is important to note that this separation of the dental needle (7) from the body of the syringe is performed with one hand (always behind the soiled needle). Unlocking is done by lifting the end (14) of the lock (11) furthest from the needle, with the thumb (fingernail or thumb 'and using a secured receptacle (double-sided tape, slide, screw, velcro) to furniture or the back of the dental chair.

The risk of contamination of the manipulator, during the separation of the needle from the syringe (if the latter uses the "concept of absolute safety", described above), is zero since only the hand carrying the syringe is used, and this hand is always, during handling, behind the soiled dental needle.

NOTE: it should be noted that the orifice 20 can be provided with a system for ejecting the needle, so that all of the latter is projected into the receptacle box, thus avoiding that the end of the dental needle

(piercing the rubber of the cartridge containing the injectable product) does not protrude outside of the orifice 20 (Figures 12, 13 and 14) and does not injure the manipulator during a gesture near the housing.

THE EJECTION SYSTEM IS CONSTITUTED (Figures 12, 13 and 14):

- Either by the elasticity of the wall in which the orifice 20 is located (activated by the pulling of the wall by the base of the needle secured to the syringe);

- either by the installation (inside the case) of a strip

REPLACEMENT SHEET elastic (plastic or metal) behind the free edges of the orifice 20; - Either by the existence of notches in the periphery of the orifice 31, thus constituting the lamellae 50, the elasticity of which is a function of their size, their thickness, of the material (constituting the lamellae or wall of the orifice 20 ) (Figure 11).

To cause a spring effect, these strips (FIG. 12) are slightly offset inside the case (relative to the wall), so as to cause their compression during the passage of the base of the needle secured to the syringe ( Figure 13) and their release (Figure 14) (precipitating the needle completely in the box) during the separation of the needle from the syringe.

We thus obtain the total disappearance inside the case of the end of the needle.

The strips are, preferably, located asymmetrically on the edges of the orifice 31, in order to be useful whatever the height of the blocking of the syringe (in the orifice 31) and therefore of the model of syringe and of 'needle.

REPLACEMENT SHEET

Claims

R E V E N D I C A T I O N S

- Dental syringe comprising a means for separating the used needle from the characterized syringe, on the one hand by the fact that there are hooks which fold over the base of the dental needle to hold it in place during the injection (the said hooks being articulated by a pivot axis on the body of the syringe), on the other hand by the fact that the hooks are activated or deactivated by a lever 14 which can be manipulated with a single finger of the hand which carries the syringe.

2 - Dental syringe characterized in that the levers and latches completely disappear when the needle is detached and are located in the open position behind the plane, from the base of the needle, leaving free space (9) allows both to fully introduce the needle into the orifice 20 of the storage box (40).

3 - Syringe, according to claims 1 and 2, characterized in that the lever in the form of a half-cylinder with a diameter slightly greater than that of the syringe.

4 - Syringe, according to claims 1 and 2, characterized in that, to obtain a locking of the device, the lever 14 to an opening 15 representing a little less than a half-cylinder, so as to obtain a clipping effect in the closed position.

REPLACEMENT SHEET 5 - dental syringe, according to one of the preceding claims, characterized in that the male tip 6 is slightly longer or wider than the female base of the needle so as to leave, once the needle dental in place, a space between the base 4 of the needle and the planar circular end (19) of the body of the syringe. This space being intended to allow to insert between the syringe and the needle the edges of the receptacle box fixed on the work surface, by means or not of a base.

6 - dental syringe, according to any one of the preceding claims, characterized in that the male end of the dental syringe has: either a single thread turn; or slight reliefs of all possible shapes on its surface, making it possible to remove the cap of the dental needle before the injection without the latter being carried away by the cap.

7 - Syringe, according to any one of the preceding claims, characterized in that it is associated, during its use, with a needle storage box, fixed on a work surface and having an orifice 20 always free ; the edges of the orifice 20 being inserted into the space 9 between needle and syringe, in order to allow the separation and the storage with one hand without any risk of pricking of the manipulator by the soiled needle. - System of attachment-separation of dental needles inseparably formed from a syringe and a box, according to any one of the preceding claims, characterized in that the orifice 20 αe the box is provided with a injection system, consisting of: - either by the elasticity of the wall of the box;

- Either by the existence of elastic strips or notches in the walls of the box, around the periphery of the orifice 20, which compri¬ mated by the base of the needle, during the pulling of the manipulator, projects the entire needle inside the storage box.

- Securing-dissociating system of dental needles, inseparable from a syringe and a box, characterized by the fact that the box may or may not be fitted with an airlock with automatic return.