FR2906476A1 - Injection device i.e. short catheter, for e.g. patient, has condemnation device formed of elastic sheath and with rigid shield adopting delivery position and condemnation position in which point covers needle - Google Patents

Abstract

The device has a needle condemnation device constituted by a flexible elastic sheath (10) that encloses a needle (A) and elastically compressible along the needle. The sheath has a top (11) that is drilled by a point of the needle during injection. The sheath has a rigid shield (20) adopting a delivery position in which the point is disengaged from the shield, and a condemnation position in which the point covers the needle. The shield passes from the delivery position to the condemnation position by axial pressure exerted by skin of a patient on the top during an injection operation.

Description

The present invention relates to a safety device for needles

  medical injection including short catheters, and more particularly a device leading to the condemnation of the tip of a catheter before injection and after injection in order to avoid accidentally contaminating punctures. Short catheters are traditionally delivered with a rigid protective cap.

  It is known that it is risky to replace the rigid cap on the catheter after use. In addition, once the rigid cap removed, the needle exposes all invasive aggressiveness usually causing some apprehension in the patient. Apprehension is also effective in the health worker in charge of the procedure, mainly because of his fear of being exposed to contaminated blood, because any patient is likely to be a virus carrier. The present invention aims at providing a safety device which makes it possible to reduce the risks of contamination and also to reduce the apprehension of the patient and the health worker, while being reliable, and simple and economical to manufacture. According to the invention, an injection device comprising a needle and a base, and a device for locking the needle after single use, are thus proposed, characterized in that the locking device consists essentially of a flexible elastic sheath. 2906476 2 completely surrounding the needle and elastically compressible along it, a vertex is adapted to be pierced by the tip of the needle during injection, and a rigid shield adapted to adopt two positions 5 inside the sheath, namely a delivery position in which said tip is disengaged from the shield, and a locking position in which it is able to cover the tip, the passage of the shield from the delivery position to the position of condemnation being effected by axial pressure exerted by the patient's skin on the top of the sheath during the injection operation. Some preferred, but not limiting, aspects of this device are the following: the sheath has a spiral rib capable of guiding its compression and expansion along the needle. * the rib is in a logarithmic spiral. * The sheath includes a high chamber and a lower chamber, separated by a neck, the spiral rib extending along the lower chamber. 25 * the shield is formed of a generally spherical hollow body in which is formed a lateral notch, and is adapted to tilt by covering the tip of the needle when it is driven by the sheath to said tip. Said notch is such that it defines two substantially diametrical contact points between the shield and the needle when the shield is along said needle. * the upper chamber is generally spherical. the shield is formed of a solid body in the general shape of a lens, provided with a piercing and capable of adopting two stable forms of inverted convexities / concavities. 10 * drilling the shield surrounded by an annular safety lip adapted to condemn said drilling after the needle has left. the device comprises a compressible container for a liquid to be injected, made in one piece with the sheath. a connecting part between the container and the sheath is fixed to a base for the needle. 20 * the sheath further comprises at least one passage for evacuation of the air it contains when it is compressed. * The device comprises a support frame located outside the sheath and adapted to enhance the forces exerted by the sheath on the shield. said framework comprises a ring surrounding the neck.

Other aspects, objects and advantages of the present invention will become more apparent upon reading the following detailed description of various embodiments thereof, given by way of non-limiting example and with reference to the drawings. FIG. 1 is a perspective view of a needle detent member used in a security device according to the invention. FIGS. 2 to 4 are side elevational views illustrating the co-operation between FIG. FIGS. 5 to 7 are side elevational views of a needle and its safety device provided with the above-mentioned member. FIGS. 8 to 10 are views in Side elevation of an injection device equipped with a needle and its safety device. FIGS. 11 to 13 are side elevational views of another injection device equipped with an injection device. e different needle condemnation. Figure 14 illustrates a detail of the needle lock member of Figures 11 to 13, and Figure 15 partially illustrates a device according to the invention equipped with a support member.

Referring firstly to FIGS. 1 to 7, a safety device according to the invention comprises two parts designed jointly to cooperate with each other as well as with a needle or catheter A. These parts comprise a flexible sheath 10. and a rigid shield 20. According to a first feature, the sheath 10, of flexible material, is irremovable by being integral with the base E of the catheter A, generally of Luer cone type, and advantageously replaces the traditional rigid cap. The sheath 10 envelops the catheter so as to completely cover it. The top 11 of the sheath comes into contact with the patient's skin at the location provided for the medical injection, according to the good operating practice. The tip P of the needle A passes through the top 11 of the flexible sheath 10 during the well-conducted procedure without the need for any action equivalent to removing a cap. Then during the operative procedure, the sheath 10 behaves like a spring sometimes in compression sometimes in expansion so as never to discover the catheter A. The sheath 10 compresses (of FIG. 5 to FIG. 6) as the invasive portion of the catheter A penetrates beneath the surface of the patient's skin.

The sheath is expanded again as the invasive portion gradually withdraws from the patient's skin after injection (Figure 6 to Figure 7). The invasive portion is delimited by the skin of the patient 30 which abuts the top 11 of the sheath 10, and the invasive portion of the catheter A is obscured by said sheath tending to recover its shape as the catheter recedes.

This first effect characteristic springing in expansion or in compression is induced, on the one hand, by the physical properties of the material used and on the other hand by the mechanical properties of the part as defined by its shape. As regards the material, it is an elastomer and more particularly a silicone converted according to the liquid silicone technology. In addition to its physical properties of constant elasticity, this material is very pleasant to the touch and a great sensory comfort. Regarding the shape of the workpiece, exit from its injection mold, it has a helical rib whose curvature responds to a spiral, preferably a logarithmic spiral. The silicone sheath thus behaves similarly to a helical spring. More specifically, the sheath being slightly tapered at one of its ends has spring properties better than those which would be obtained with a cylindrical shape, ie with a rib with parallel turns. One of these physical properties is the assurance of good coaxiality with the catheter.

This coaxiality of the retraction and expansion stroke of the sheath tends to decrease the accordion effect. Stroke 15 is rather rectilinear with a very small radius of curvature and tending towards linearity. An accordion effect would be likely to bias the catheter in flexion during injection by inflicting a curvature, which is to be avoided to optimize the comfort of the medical injection. This property of co-axiality of the sheath contributes to the effective protection of the tip of the needle before the injection and also after the medical injection, by cooperating with the rigid shield 20, the shape of which can differ according to the type of medical injection to achieve. According to the good operating practice a given catheter is dedicated to a given type of medical injection. There is a standard ISO classification of catheters and their specific use, identified by color codes. Three types of injections can be distinguished here: hypodermic, intramuscular, and intravenous. To each type of injection corresponds a family of standardized catheters particularly determined by the depth of penetration and thus the length and diameter of the catheter. The first example given here corresponds to a hypodermic injection catheter cooperating with a generally spherical contour shield 20 illustrated in particular in FIGS. 1 to 10, which will be seen to facilitate medical self-injection without intervention. a third party other than the patient himself.

A variant of the shield, of elliptical shape, relating to intravenous medical injection, which more generally requires the intervention of a health worker, will then be described with reference to FIGS. 11 to 13.

The flexible sheath and the hard shield together form an effective protection against accidental needlesticks, whether the medical injection is practiced by the patient on himself, or through a third health professional. . The invention has been developed based on the sequential analysis of the specific surgical procedure for each type of injection, in accordance with the good practice, aiming at not fundamentally changing the habits of the health workers. The invention thus ensures that at each operative procedure the protective device intuitively embraces the customary gestures of the operator, thus reducing the need for training of health personnel in the use of the new device and advantageously providing a feeling of security to the patient to encourage him to self-inject the prescribed medication without the expensive competition of a health professional. The cooperation between the silicone sheath 10 and the rigid shield 20 preferably made of thermoformed plastic, to accomplish the required safety function, preoperative, operative and post-operative, will now be described in detail.

As illustrated in FIGS. 1 to 4, the shield 20 is in the form of a hollow sphere, pierced by a lateral lumen or notch 21 extending from the top to the base and having the general shape of an hourglass.

This notch is delimited by the intersection of the sphere with a cylinder entirely inscribed in one of the two hemispheres and arranged so that at each point the cross section of this virtual cylinder is tangent to the plane practically delimiting the two hemispheres in question. . This indentation is formed because the diameter of the cylinder is slightly greater than the radius of the sphere. In the positions illustrated in FIGS. 2, 3, 5 and 6, the shield 20 and the needle A are in contact at two points called P1 and P2 equidistant from the center 0 of the sphere. The three points P1, 0 and P2 are aligned on the vertical hemispherical plane 20 and on the tangent line of the virtual cylinder which delimits the indentation 21. In FIGS. 2, 3, 5 and 6, the shield, as long as it passes through apart from the needle, is free to perform gyratory movements about the axis of the needle, as well as translational movements along the axis of the needle, from top to bottom and from bottom up.

When, in an upward translation movement, the high point of support P1 between the shield and the needle no longer exists, the shield is likely to adopt a rotation typically around the point O, or even around the 2906476 10 fulcrum P2. The amplitude of the possible rotation is all the greater as the point B approaches the point of the needle.

The sheath 10 of elastomer constitutes the coupling between the shield 20 and the base E of the needle A. The sheath is for this purpose formed of two chambers, namely an upper chamber 13, of generally spherical shape, designed to receiving the spherical shield 20 at the end of the injection operation 10 and a generally conical trunk 14, of variable longitudinal dimension and adapted to the length of the catheter A. Its section is wide upwards and narrow downwards and carrying the aforementioned spiral rib 12 providing the desired coaxial spring effect.

Once the sheath 10 has been compressed against the patient's skin during the medical injection, the spring effect makes it possible, as mentioned above, to release the needle A as it penetrates under the epidermis. . The spring effect also ensures the deployment of the trunk 14 of the sheath, the top 11 of the upper chamber 13 remaining in contact with the surface of the skin of the patient, as the needle leaves the epidermis. In Figure 5, the upper part of the trunk 14 holds the spherical shield 20 prisoner in the delivery position, along the needle A and in support points P1 and P2.

When sheath 10 and shield 20 are moved downwardly from the needle, the base of the shield ends up abutting against the upper part of the base E of the needle.

The vertical reaction carried out by such an abutment forces the spherical shield to pass into the upper chamber 13 of the sheath, with temporary elastic expansion of the neck 15 which separates the two chambers (FIG. 6). The shield 20 is advantageously coated with a medical liquid silicone film to reduce friction and facilitate the forcing of the passage of said neck under the force of intromission movement of the needle under the epidermis of the patient. The passage of the neck 15 is also facilitated by the fact that the horizontal diameter of the shield encircled by the sheath 10 is designed to be reduced as the section of the conical trunk 14 of the sheath 10 decreases. From the spherical shape the shield 20 passes transiently to an ovoid shape when crossing the neck 15.

This results in a slight translation of the shield 20 towards the space of the upper chamber 13 in the body of the trunk of the lower chamber 14 of the sheath 10 under the elastic pressure of said sheath 10 which exerts a coaxial thrust to the catheter from the bottom of the spherical shield 25 pushing towards the upper chamber 13 of the sheath 10. Passed the neck 15, the spherical shield is trapped in the upper chamber 13 of the sheath, ready to accompany the elastic return movement of said sheath when extracting needle A after injection.

At the end of this race, the shield 20 loses its support point P1, and under the force exerted by the wall of the upper chamber 13 of the sheath 10, it comes to tilt around the point 0 and condemn the tip of the A needle 5 preventing it from re-drilling the sheath after one single use. It will be noted here that the shield 20 always pivots in the desired direction regardless of the rotational movements that it is likely to have made around the axis of the needle A during its translation towards the tip of the needle and that this rotation about its center results from the very slight differential between the radius of the indented hemisphere and the radius of its other hemisphere 15 of the shield 20. FIGS. 11 to 13 illustrate the variant where the flexible sheath 10 cooperates with a rigid shield 20 of elliptical shape for the practice of an intravenous injection by a health worker. Since the catheter may be very short so as to pass only one wall of the patient's vein, it follows that the longitudinal dimension of the sheath 10 and the shield 20 may be reduced. The sheath 10 still includes here an upper chamber 13 and a lower chamber 14 delimited by a trunk.

On the other hand, the shape of the upper chamber 13 is here of elliptical axial section, with for example a transverse diameter equal to one and a half times the axial diameter.

The rib 12 of the trunk here again provides the coaxial spring effect, the trunk being connected to the base E of the catheter. The shield 20 here adopts the shape of a lens pierced at its center 22 to provide a passage to the catheter. Whatever the operating position before the injection, during or after the injection, the rigid shield in the form of a lens remains in this case constantly trapped in the upper chamber 13, where it can however adopt two different positions. In the delivery position, the lens-shaped shield has a concave outer surface (at the top of the figures) and a convex inner surface, and the tip of the needle A is positioned at the center of the horizontal diameter of the shield, optionally crossing it for a short distance (Figure 11).

In the operating position the top 11 of the sheath comes into contact with the patient's skin, which opposes a reaction force to the penetration motion imposed by the operator.

This reaction force is reflected on the periphery of the shield which then abruptly passes to a second stable state where its outer face is convex. This while the needle has already begun to cross (Figure 12: the catheter is fully tucked under the skin).

When the catheter A withdraws from the skin, the shield 20, still in the convex position, accompanies the sheath 10, which propels the shield 20 into its convex state beyond the tip of the needle. The catheter is no longer guided in the bore 22 of the rigid shield, its tip is condemned (Figure 13) because the stresses then exerted on the shield by the sheath are necessarily such that it will shift laterally. According to a variant, illustrated diagrammatically in FIG. 14, it may be provided that the bore 22 of the shield is itself locked by a safety valve or the like, in this case an annular lip 23 surrounding the bore 22 and which, thanks to a certain elasticity of the material of the shield 20, come close the latter by virtually eliminating any risk of new entry by the tip of the needle. Referring now to FIGS. 8 to 10, there is shown a medical injection device that can be manufactured in one piece according to the technology of injection blowing of polymers (polypropylene, polyethylene, etc.) or of elastomer ( liquid silicone). Thus the sheath 10 and a container 100 for injection liquid, similar to that described in the patent application WO-2004/009149 in the name of the Applicant, are molded in one piece while being separated by a connecting portion 110. The spiral-shaped rib, preferably logarithmic, of the container 100 is illustrated at 102. The needle A is mounted in an unillustrated base 30 attached to the connecting portion 110.

This base is preferably associated with an externally communicating non-return valve, also not shown, which allows air in the upper part of the injection device to be compressed during the start of injection. to be evacuated. Preferably, the inner surface of the connecting portion 110 is ultrasonically welded to the base, made of a polymer compatible with the material forming the container 100, the sheath 10 and their connecting portion 110. The shield is here the same type as that illustrated with reference to Figures 1 to 7, and operates according to the same principle. It will be noted here that this shield, thanks to the specific shape of its indentation, is able to pass through elastic deformation of its spherical shape at rest, which it naturally tends to resume, an elongated ovoid shape along the axis of the needle. This facilitates its crossing of the neck 15 separating the low and high chambers 14 and 13 of the sheath 10.

According to another embodiment of the invention, illustrated diagrammatically in FIG. 15 and intended in particular for intramuscular injection devices, with a needle whose length is typically 40 mm, an external reinforcement frame 30 is provided. of the sheath 10 which comprises a ring 31 surrounding the sheath 10 at its neck 15 and a series of arms 32 extending from the ring towards the base E, to which they are secured to one way or another, and able to deform elastically to allow said ring to move along the needle accompanying the neck 15. During the recovery phase, these arms 32 have the role of to assist the force exerted by the elasticity of the sheath 1On to more effectively propel the shield 20 in its upward stroke, so that it passes from its position in the lower chamber 14 to its position in the upper chamber 13.

Finally, it will be observed that, as mentioned above with reference to FIGS. 8 to 10, means can be provided for evacuating the air contained between the body of the needle and the internal volume of the sheath. Thus, although small, this volume of air as it is compressed should preferably be able to escape so as not to hinder the axial compression of the sheath. If all of this overpressure is not able to escape through the gap between the pierced apex 11 of the sheath and the needle, it is advantageous to provide the sheath with a bellows at its base, or still perforate for example along its rib 12.

Claims (14)

  1. Injection device comprising a needle (A) and a base (E), and a device for locking the needle after single use, characterized in that the locking device consists essentially of a flexible elastic sheath ( 10) completely surrounding the needle (A) and elastically compressible along it, a vertex (11) is adapted to be pierced by the tip of the needle during the injection, and a rigid shield (20) adapted to adopt two positions inside the sheath (10), namely a delivery position in which said tip is disengaged from the shield (20), and a locking position in which it is able to cover the point, the passage of the shield (20) from the delivery position to the locking position being effected by axial pressure exerted by the skin of the patient on the top (11) of the sheath (10) during the operation of 'injection.   2. Device according to claim 1, characterized in that the sheath (10) has a rib (12) spiral adapted to guide its compression and expansion along the needle (A).   3. Device according to claim 2, characterized in that the rib (12) is in a logarithmic spiral.   4. Device according to one of claims 2 and 3, characterized in that the sheath (10) comprises an upper chamber (13) and a lower chamber (14) separated by a neck (15), the spiral rib (12). ) extending along the lower chamber. 2906476 18   5. Device according to one of claims 1 to 4, characterized in that the shield (20) is formed of a generally spherical hollow body in which is formed a lateral notch (21), and is adapted to tilt overlying the tip of the needle (A) when it is led by the sheath (10) towards said tip.   6. Device according to claim 5, characterized in that said notch (21) is such that it defines two substantially diametral contact points between the shield (20) and the needle (A) when the shield is along said needle. 15   7. Device according to one of claims 5 and 6 taken in combination with claim 4, characterized in that the upper chamber (13) is generally spherical.   8. Device according to one of claims 1 to 4, characterized in that the shield (20) is formed of a solid body in the general shape of a lens, provided with a bore (22) and capable of adopting two stable forms of inverted convexities / concavities. 25   9. Device according to claim 8, characterized in that the drilling of the shield (20) is surrounded by an annular safety lip (23) adapted to condemn said drilling after the needle (A) has left.   10. Device according to one of claims 1 to 9, characterized in that it comprises a compressible container (100) for a liquid to be injected, made in one piece with the sheath (10). 2906476 19   11. Device according to claim 10, characterized in that a connecting portion (110) between the container (100) and the sheath is fixed to a base (E) for the needle.   12. Device according to one of the preceding claims, characterized in that the sheath (10) further comprises at least one passage for the evacuation of the air it contains when it is compressed. 10   13. Device according to one of claims 1 to 12, characterized in that it comprises an assistance frame (30) located outside the sheath (10) and adapted to reinforce the forces exerted by the sheath ( 10) on the shield (20).   14. Device according to claims 4 and 13 taken in combination, characterized in that said frame (30) comprises a ring (31) surrounding the neck. 5 20