WO2008043895A2

WO2008043895A2 - Injection device with needle, provided with a means for automatically disabling the needle

Info

Publication number: WO2008043895A2
Application number: PCT/FR2007/001602
Authority: WO
Inventors: Pierre Lahlou
Original assignee: Biofront
Priority date: 2006-09-30
Filing date: 2007-10-01
Publication date: 2008-04-17
Also published as: WO2008043895A3; FR2906476A1; FR2906476B1; WO2008043895A8

Abstract

An injection device comprises a needle (A) and a base (E), and a means for disabling the needle after a single use. The disabling means comprises a flexible elastic sheath (10; 500) which at least partially surrounds the needle (A) and is elastically compressible along the length thereof, and a rigid shield (20; 200) that can be selectively retained by the sheath in a delivery position in which the shield bears laterally against the needle and in which the tip of the needle can be disengaged from said shield (20; 200), characterized in that a stress applied to the sheath during the injection causes the shield to leave its delivery position and move axially in the direction of the tip of the needle, such that it flips over spontaneously and covers said tip.

Description

"NEEDLE INJECTION DEVICE HAVING AUTOMATIC NEEDLE CONDEMNATION DEVICE"

The present invention relates to a safety device for medical injection needles including short catheters, and more particularly to a device leading to the condemnation of the tip of a catheter before injection and after the injection for the purpose of avoid accidentally contaminating bites.

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. (HIV, hepatitis, etc.)

The present invention aims to provide a safety device that provides all or part of the following benefits: reduced risk of contamination, reduced apprehension of the patient and the health worker, simplicity, reliability and low cost. According to the invention, an injection device comprising a needle and a base, and a device for condemning the needle after use, are thus proposed. unique, characterized in that the locking device consists essentially of a resilient flexible sheath completely surrounding the needle and elastically compressible along it, a vertex is adapted to be pierced by the tip of the needle when injection, and a rigid shield adapted to adopt two positions inside the sheath, namely a delivery position in which said tip is clear of 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 locking position is effected by axial pressure exerted by the skin of the patient on the top of the sheath during the injection operation.

Some preferred, but not limiting, aspects of this device are:

* The sheath has a spiral rib adapted to guide its compression and expansion along the needle.

* the rib is in a logarithmic spiral.

The sheath comprises an upper chamber and a lower chamber, separated by a neck, the spiral rib extending along the lower chamber.

* The shield is formed of a generally spherical hollow body in which is formed a lateral notch, and is adapted to tilt 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 sheath is open at both ends.

* The sheath has a bead adapted to cooperate with an intermediate notch of the shield to retain the latter without its delivery position.

* The shield is secured to a ring slidable along the base of the needle and adapted to be biased by the sheath when it tends to resume its rest position.

* The sheath has a second bead adapted to cooperate with a notch of the base, the sheath covering the ring.

* The ring has a lateral opening, allowing, when aligned with the notch of the shield, the establishment of the assembly forming the shield and the ring laterally on the assembly formed of the needle and its base .

Other aspects, objects and advantages of the present invention will appear better on reading the following detailed description of various embodiments thereof, given by way of nonlimiting example and with reference to the appended drawings, in which: : FIG. 1 is a perspective view of a needle locking member used in a safety device according to the invention,

Figures 2 to 4 are side elevational views illustrating the cooperation between such a member and a needle, in different positions,

Figures 5 to 7 are side elevational views of a needle and its safety device provided with the aforementioned member,

FIGS. 8 to 10 are side elevational views of an injection device equipped with a needle and its safety device,

Figures 11 to 13 are side elevational views of another injection device equipped with a different needle lock member.

FIG. 14 illustrates a detail of the needle locking member of FIGS. 11 to 13,

FIG. 15 partially illustrates a device according to the invention equipped with a support member,

FIG. 16 is an exploded perspective view of a safety device according to a variant of that of FIGS. 1 to 10,

FIGS. 17a to 17d, including four views in elevation and in section of a part of the element of FIG. 17, and Figures 18a and following are views in axial section illustrating different phases of the use of the device of Figure 16.

Referring firstly to Figures 1 to 7, a safety device according to the invention comprises two parts designed jointly to cooperate with each other and 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.

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The sheath 10 envelops the catheter so as to completely cover it. The top 11 of the sheath comes into contact with the skin of the patient at the location provided for the medical injection, following 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 it being necessary to carry out any act equivalent to removing a cap.

Then during the operative procedure, the sheath 10 behaves as a spring sometimes in compression sometimes in expansion so as never to discover the catheter A.

The sheath 10 compresses (Figure 5 to Figure 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 which abuts with the top 11 of the sheath 10, then the invasive portion of the catheter A is masked by said sheath tending to recover its shape, as the catheter withdraws.

This first effect characteristic spring expansion or 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.

Regarding 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. Specifically, the sheath being slightly conical at one of its ends has spring properties better than those which would be obtained with a cylindrical shape, namely 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. The race is rather rectilinear with a very small radius of curvature and tending towards linearity.

An accordion effect would be likely to urge the catheter in flexion during the 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.

With 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 the intervention of the patient. 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 rigid shield together form an effective protective device against accidental needlestick injuries, whether the medical injection is practiced by the patient on himself, or through a third party health professional.

The invention has been developed according to the sequential analysis of the operative procedure specific to each type of injection, in accordance with the good practice, aiming at not fundamentally changing the habits of health workers.

The invention thus ensures that, in each operative procedure, the protective device intuitively follows the customary gestures of the operator, thus reducing the need for training health personnel in the use of the new device and advantageously giving a feel safe to the patient to encourage self-injection 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 perform 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 slot 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 in each point the cross section of this virtual cylinder is tangent to the plane virtually 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 designated P1 and P2 equidistant from the center O of the sphere.

The three points P1, O and P2 are aligned on the vertical hemispherical plane and on the tangent line of the virtual cylinder which delimits the notch 21.

In FIGS. 2, 3, 5 and 6, the shield, as far as the needle goes through, is free to make gyratory movements around the axis of the needle, as well as translational movements along the axis of the needle, from top to bottom and from bottom to top.

When, in an upward translation movement, the high point of contact Pl between the shield and the needle no longer exists, the shield is likely to adopt a rotation typically around the point 0, or even around the point d P2 support. 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 accommodate the spherical shield 20 at the end of the injection operation 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 bearing the spiral rib 12 above providing the desired coaxial spring effect.

The sheath 10 can be either threaded from the top or engaged laterally, in which case it is provided with an axial slot allowing this movement and closing after placement.

Once the sheath 10 compressed against the patient's skin during medical injection, the spring effect allows as said above to clear the needle A as it penetrates 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 of the points P1 and P2.

When the sheath 10 and the shield 20 are moved downwardly from the needle, the base of the shield eventually comes into abutment against the upper part of the base E of the needle.

The vertical reaction performed 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 forcing 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 pushing it 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 during the extraction of the needle A after the 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 needle A in 1 'preventing to re-drill 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 around its center results from the very slight difference between the radius of the indented hemisphere and the radius of its other hemisphere of the shield.

To promote this movement, it can be ensured between the sheath 10 and the shield 20 asymmetry of friction, for example by providing localized pins or other reliefs at the inside of the sheath, limiting the area of contact with the shield and therefore the friction.

Figures 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 can 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 can be reduced.

The sheath 10 still includes here an upper chamber 13 and a lower chamber 14 delimited by a trunk.

In contrast, the shape of the upper chamber 13 is 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 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 shaped 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 (top in 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, possibly traversing this one for a short distance (figure 11).

In the operating position, the top 11 of the sheath comes into contact with the skin of the patient, who opposes a reaction force to the penetration movement 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 schematically in FIG. 14, provision may be made for the bore 22 of the shield to be 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 to close this one eliminating practically any risk of new entry by the tip of the needle.

Referring now to Figures 8 to 10, there is shown a medical injection device is adapted to be manufactured in one piece according to the technology of injection molding polymers (polypropylene, polyethylene ...) or elastomer (silicone liquid).

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 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 a non-illustrated base attached to the connecting portion 110.

Preferably, this base is associated with a non-return valve communicating with the outside, also not shown, allowing the air located in the upper part of the injection device and compressed during the beginning of the injection can 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 of the same type as that illustrated with reference to Figures 1 to 7, and operates on the same principle.

It will be noted here that this shield, thanks to the specific shape of its indentation, is able to pass by 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, schematically illustrated 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. 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 in a manner 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 assisting 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.

It will be observed finally that, as mentioned above in connection with FIGS. 8 to 10, means may be provided for evacuating the air contained between the body of the needle and the interior 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 excess pressure is not able to escape through the gap between the top 11 pierced with the sheath and the needle, it is advantageous to provide the sheath with a bellows at its base, or to open it for example along its rib 12.

Referring now to Figures 17 and following, there is shown a variant of the first embodiment to facilitate its mass industrialization.

The shield 200 is no longer housed in a sheath, but is connected to a base 230 in the form of split ring by means of a connecting lug 220 which tends to maintain a substantially constant axial distance between the shield and the ring, while allowing the tilting of the shield according to the principle described above. The ring 230 has at its base a flare 231 for purposes explained below.

The element defining the shield, the tab and the ring is preferably integrally molded of plastic material of appropriate rigidity.

The device here comprises a specifically designed needle hub 400, the inner face of which preferably defines a standard Luer cone enabling assembly of the assembly on a container of any type. On the outside, the base 400 comprises a generally cylindrical sliding zone 420 delimited by two ribs or beads 410, 430, the axial height of this zone 420 being substantially greater than that of the ring 230, and its diameter being substantially equal to the inner diameter of said ring.

The device finally comprises a generally cylindrical sheath or sheath 500 open at both ends and having at each of them a re-entrant bead, respectively 510 and 520. The sheath has a high elastic deformability,

The upper bead 510 is intended to cooperate with a recess or peripheral notch 215 arranged generally equatorially (or inclined) on the shield 200. The lower bead 520 is intended to cooperate with a notch or notch 440 formed in the base 400 below the rib 430.

The detailed shape of the shield is illustrated in Figures 17a to 17d which are respectively an axial view (from above), a back view, a side view and a front view.

The shield has two recesses at the top and at the bottom, respectively 210a and 21b, so that the two points of contact of the needle A against the shield in the delivery position are shifted towards the interior of the imaginary sphere circumscribing the shield and that the tip of the needle does not protrude outside the sphere, as shown in Figure 18a. Figure 18a illustrates the assembly of the delivery position. The shield 200 is in stable lateral support against the needle A in the vicinity of its tip, while the ring 230 occupies the low position in its sliding zone 420. The sheath 500, which has been set up preferably from below around the element defining the shield 200 and its ring 230 and around the needle A provided with its base 400, has its upper bead 510 received in the notch 215 of the shield and its lower bead 520 received in the notch 440 of the base 400.

When an injection is performed, the skin of the patient pushes, downwards in the figures, the shield 300 as well as the sheath 500 (FIG. 18b), the latter contracting elastically, its lower part sliding against the outside of the ring 230 progressively crossing its flare 231.

When the injection is complete, the sleeve, tending to resume its rest position, solicits by its lower region the ring 230 upwards in the figures, this action being favored by the clearance 231 which provides a non-return function.

This solicitation is reflected in the shield 200, because the distance thereof to the ring 230 tends to remain constant by the connecting lug 220, and this with sufficient force to expel the shield out of the right of way defined by the upper bead 510 of the sheath. Due to an asymmetry of efforts ensured, either by coefficients of friction adjusted at the level of the cooperation between the bead 510 and the notch 215, or by an inclination of the plane of said notch, or by the point of action of the lug 220, or by any other effect, the shield, being no longer in double support laterally against the needle A and can tilt so as to cover the tip and condemn.

Of course, many other embodiments are possible. Thus the skilled person will perform any combination of features described in connection with the various embodiments, including outside the scope of the appended claims.

Claims

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 comprises an elastic flexible sheath (10; 500) at least partially surrounding the needle (A) and elastically compressible therealong, a rigid shield (20; 200) adapted to be selectively retained by the sheath in a delivery position in which the shield is in lateral support against the needle and where the tip of the needle can be disengaged from said shield (20; 200), and in that a stress applied to the sheath during the injection is able to cause the shield to leave its delivery position by moving it axially towards the tip of the needle so that it tilts spontaneously covering said tip.

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.

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 covering the needle tip (A) when driven 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 diametrical contact points between the shield (20) and the needle (A) when the shield is along said needle.

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, 5 and 6, characterized in that the sheath is open at both ends.

9. Device according to claim 8, characterized in that the sheath has a bead adapted to cooperate with an intermediate notch of the shield to retain the latter without its delivery position.

10. Device according to claim 9, characterized in that the shield is integral with a ring slidable along the base of the needle and adapted to be urged by the sheath when it tends to resume its position. rest .

11. Device according to claim 10, characterized in that the sheath has a second bead adapted to cooperate with a notch of the base, the sheath covering the ring.

12. Device according to claim 10 or 11 taken in combination with claim 5 or 6, characterized in that the ring has a lateral opening, allowing, when aligned with the notch of the shield, the introduction of the assembly forming the shield and the ring laterally on the assembly formed by the needle and its base.