PASSIVE INJECTION DEVICE WITH AUTOMATIC SECURING MEANS

Abstract

Disclosed is an injection device of the type including a cylindrical body enclosing a reservoir containing a product to be injected, which is slidably mounted in the body, which is open at one end on an injection needle and is closed at its other end by a plunger mounted movable in translation in the reservoir under the action of a plunger rod provided with a control member, the surface of the distal end of the body being coated with adhesive capable of ensuring that this surface is held on the skin of a patient. This device is characterized in that it includes a mechanism for securing the needle, the activation of which is ensured by the adhesive when a withdrawal effort is exerted on the injection device.

Claims

1. An injection device of the type comprising a cylindrical body (3) enclosing a reservoir (9) containing a product to be injected, which is slidably mounted in the body (3), which is open at one end on an injection needle (11) and is closed at another end by a plunger (16) mounted so as to be movable in translation in the reservoir under the action of a plunger rod (17) provided with a control member (19), the surface of the distal end (3a) of the body (3) being coated with adhesive means capable of ensuring that this surface is held on the skin (4) of a patient wherein the injection device comprises means for securing the needle, the activation of which is ensured by the adhesive means when a withdrawal effort is exerted on the injection device.

2. The injection device according to claim 1 wherein the control member consists of a cylindrical cap (19) which is slidably mounted on the body (3), the plunger rod (17) being secured by a proximal end to the bottom of this cap (19) and passing through an element (21, 21′) mounted so as to be movable in translation in the cap.

3. The injection device according to claim 2 wherein the movable element consists of a nut (21) into which the plunger rod (17) is screwed.

4. The injection device according to claim 2 wherein the movable element consists of a drawer (21′) in which the plunger rod (17′) is slidably mounted.

5. The injection device according to claim 1 wherein the proximal end of the reservoir (9) is secured to the element (21, 21′).

6. Injection device according to claim 1 wherein the proximal end (3b) of the body (3) comprises at least one deformable tab (14) which extends towards the bottom of the cap (19) and ends with a radial boss (14a) extended by a bevel (14b).

7. The injection device according to claim 6 wherein the distal face of the element (21, 21′) comprises a circular groove (23) of a shape complementary to that of the bevel (14b) of the deformable tab (14) so as to receive the deformable tab when the element (21, 21′) is applied against the proximal face (3b) of the body (3) and to deform the deformable tab in the direction of the longitudinal axis (xx′) of the body.

8. The injection device according to claim 7 wherein the internal face of the cap (19) comprises a first proximal circular stop (25), the distal face (25b) of which is perpendicular to the axis (xx′) of the body (3), and a second distal circular stop (26) of rectangular cross-section perpendicular to the axis (xx′) of the body (3).

9. The injection device according to claim 8 wherein the height (H) of the circular stops (25,26) is such that, when the element (21, 21′) is applied against the proximal face (3b) of the body (3), the deformation of the tab (14) allows the passage of the radial boss (14a) at their level during a displacement of the cap (19) relative to the body (3).

10. The injection device according to claim 9 wherein the height (H) of the circular stops (25,26) is such that, when the element (21, 21′) is not applied against the proximal face (3b) of the body (3), the tab (14) is released and the radial boss (14a) abuts against the distal face of the proximal circular stop (25) and stops against the proximal face of the distal circular stop (26) when moving the cap (19) relative to the body (3).

11. The injection device according to claim 1 wherein, in the rest position, or not in use, the distal surface (3a) of the body (3) which is coated with adhesive means is protected by a removable membrane.

12. The injection device of the type comprising a cylindrical body (3) enclosing a reservoir (9) containing a product to be injected, which is open at one end on an injection needle (11) and is closed at another end by a plunger (16) mounted so as to be able to move in translation in the reservoir under the action of a control member (19) wherein the surface of the distal end (3a) of the body (3) is extended by a boss (3c).

13. The injection device according to claim 12 wherein the boss (3c) is of planar shape and substantially perpendicular to the longitudinal axis (xx′) of the body (3).

14. The injection device according to claim 12 wherein the boss (3c) is of convex shape.

15. The injection device according to claim 2 wherein the proximal end of the reservoir (9) is secured to the element (21, 21′).

16. The injection device according to claim 2 wherein the proximal end of the reservoir (9) is secured to the element (21, 21′).

17. The injection device according to claim 2 wherein the proximal end of the reservoir (9) is secured to the element (21, 21′).

18. The injection device according to claim 2 wherein the proximal end of the reservoir (9) is secured to the element (21, 21′).

19. Injection device according to claim 2 wherein the proximal end (3b) of the body (3) comprises at least one deformable tab (14) which extends towards the bottom of the cap (19) and ends with a radial boss (14a) extended by a bevel (14b).

20. Injection device according to claim 3 wherein the proximal end (3b) of the body (3) comprises at least one deformable tab (14) which extends towards the bottom of the cap (19) and ends with a radial boss (14a) extended by a bevel (14b).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] An embodiment of the present invention will be described below, by way of non-limiting example, with reference to the appended drawing in which:

[0038] FIG. 1 is a view in axial and longitudinal section of an embodiment of an injection device according to the invention shown in the rest or pre-injection position,

[0039] FIG. 1a is an enlarged view of zone A of the injection device as shown in FIG. 1,

[0040] FIG. 2 is a perspective view of the injection device shown in FIG. 1 before the injection phase,

[0041] FIG. 3 is an axial and longitudinal sectional view of the injection device of FIG. 1 shown in progress injection,

[0042] FIG. 3a is an enlarged view of zone B of the injection device as shown in FIG. 3, FIG. 4 is an axial and longitudinal sectional view of the injection device of FIGS. 1 and 3 shown once the injection completed,

[0043] FIG. 5 is a view in axial and longitudinal section of the injection device of FIGS. 1 to 4 shown after injection once placed in the safety position.

[0044] FIG. 5a is an enlarged view of zone C of the injection device as shown in FIG. 5.

[0045] FIGS. 6 to 9 show a second embodiment of an injection device according to the invention, in which the injection is carried out by translation means, respectively in the rest position, during injection, at the end of the injection and in the safety position, FIG. 10 is an alternative embodiment of the injection device according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] FIGS. 1 to 5 show an implementation of an injection device according to the invention of the type in which the injection is performed by means of rotation.

[0047] This injection device 1 comprises a tubular body 3 which is hollowed out of an axial cylindrical duct 5 which opens into a cylindrical distal chamber 7 of larger diameter.

[0048] The conduit 5 receives a reservoir, constituted in this embodiment, by a syringe 9 containing the product to be injected which ends with an injection needle 11. The distal end of the syringe 9 is provided with an O-ring seal 12 which is recessed in a cuvette 10 of the body 3, and the length a of the chamber 7 is such, that in the rest position, or pre injection, as shown in FIG. 1, the injection needle 11 is housed inside the chamber 7.

[0049] The proximal end 3b of the body 3 ends with two diametrically opposed hooking tabs 14 which themselves end in an external boss 14a of height H followed by a bevel 14b, these tabs being made deformable by the presence of an internal space 15.

[0050] A plunger 16 is slidably mounted inside the syringe 9 under the action of a threaded plunger rod 17. The proximal end of this plunger rod is integral with the bottom of an actuating member consisting of a cylindrical cap 19 whose internal diameter D is slightly greater than that d of the body 3 increased by the height H of the two stops 14a, so as to allow the cap 19 to slide on the body 3. We thus have D=d+2×H. In the rest position, as shown in FIG. 1, the distal end of this cap 19 is slightly engaged on the body 3 so as to favour the guiding of the latter.

[0051] The internal face of the cap 19 comprises a first circular distal stop 26 of height h, of rectangular cut, aiming to keep the body 3 locked in the cap 19 during the withdrawal of the needle from the body 4 once the administration of the product is finished. Finally, the internal face of the cap also comprises a second circular proximal stop 25 of height h, the proximal face 25a of which is preferably inclined and the distal face 25b is radial, and spaced from the first stop 25 by a distance equal to the width of the boss 14a, and which is intended, as explained below, to prevent a second exit of the needle 11 once the injection phase is finished.

[0052] A cylindrical nut 21 of thickness e forming a stop is screwed onto the plunger rod 17 and comprises a cup 20 in which the proximal end of the syringe 9 is fixed. The periphery of the distal face of the nut 21 is hollowed out by a circular groove 23 of a shape complementary to that of the bevel 14b of the deformable tabs 14. The diameter b of this nut 21 is slightly less than the internal diameter D of the cap 19 from which the heights H of the two bosses 14a have been subtracted. We thus have b=D−2×H.

[0053] The distance c which exists, when the injection device is at rest, as shown in FIG. 1, between the proximal end 3b of the body 3 and the distal face of the nut 21 allows to control the distance of which the injection needle 11 will emerge from the distal face 3a of the body 3 during the injection, as explained below.

[0054] This distal face 3a of the cylindrical body 3 can be formed by the annular surface of the body 3 or, as in the embodiment shown in FIG. 2, include an extension part 3c plane and perpendicular to the longitudinal axis xx′ of the injection device, allows to increase the size of this surface.

[0055] According to the invention, the latter is coated with an adhesive capable of allowing adhesion with the skin 4 of the patient to be treated, this adhesive being protected in the position of non-use, by a pellicle or a film 27.

[0056] For example, use will be made of adhesive surfaces based on silicone, acrylate, polyacrylates, or any other known copolymers entering into the adhesive surface composition for medical devices, such as for example dressings, ostomy bags, electrodes and electrosurgical plates, patches or even hair prostheses.

[0057] In an alternative embodiment, the extension part 3c may be non-planar and in particular be of convex shape as shown in FIG. 10.

[0058] Thus, during the implantation of the needle in the patient's body, the deformation of the surface of the skin by depression will adapt better to the whole of the sticky surface, adhere better to it and better fix the device to his injection site.

[0059] At the end of the injection, a simple movement perpendicular to the surface of the skin around the needle will allow the injection device to be withdrawn, thus avoiding rocking movements liable to move the needle in the body. This perpendicular withdrawal will also facilitate the detachment of this adhesive surface: the skin located further on the periphery of said adhesive surface will peel off first and thus gradually to the part closest to the needle.

[0060] This non-planar sticky surface, which avoids the detachment of the entire surface at the same time after injection, increases the strength of the bond without making its removal difficult or painful. This upward and progressive movement of the skin at the time of the withdrawal of the needle also avoids the usual bleeding at the injection site linked to a phenomenon of suction of the needle in the opening that it made in the tissues. By pulling the skin back when the needle is withdrawn, this sticky surface system compensates for this phenomenon of suction and ensures that the opening closes without causing blood resurgence.

[0061] It will be noted that in the injection device according to the invention, the adhesive surface has two functions.

[0062] A first function, known from the prior state of the art, is to stabilize the injection device with respect to the patient's skin so as to prevent any slippage during the injection phase.

[0063] A second function, as explained in detail below, is to control the activation of a safety mechanism of the injection device when the user exerts a pulling force on it to remove it from the patient's body, thus making this safety automatic, without the user having to perform any additional action.

[0064] Under these conditions, the operation of the injection device according to the invention is established as described below.

[0065] After removing the protective film 27, the user brings the adhesive distal end of the injection device into contact with the area of the patient's body, where he wishes to perform the injection. Therefore this end of the injection device, due to its adhesion with the injection zone, is stabilized.

[0066] Then, the user exerts a linear push on the cap 19 in the direction of the arrow F until the nut 21 comes into abutment with the proximal face 3b of the body 3, which has the effect on the one hand of making the injection needle 11 come out of the injection device and introduce it into the body 4 of the patient, as shown in FIG. 3. On the other hand, at the end of this translation movement, the bevels 14b of the tongues 14 penetrate into the groove 23 of the nut 21, which has the effect of deforming the tongues 14 inwards and ensuring a rotational connection of the nut 21 with the body 3. Moreover, due to the inward deformation of the tongues, they are free and able to avoid blocking the cap's movement when, during injection, they reach the circular stops 25 and 26.

[0067] The injection device is therefore ready to proceed with the injection of the treatment product.

[0068] To do this, the user rotates the cap 19, which he can moreover perform with one hand due to the connection existing between the distal part 3a of the body 3 with the body 4 of the patient which is ensured. by the adhesive product.

[0069] During this rotation of the cap 19, the plunger rod 17 is screwed into the nut 21, and the latter being immobilized in rotation with respect to the body 3, the plunger 16 moves in the syringe 9 and administers the treatment product in the patient's body until the plunger reaches the syringe neck 9, as shown in FIG. 4, or the user stops his injection.

[0070] Once the injection has been carried out, the user pulls the cap 19 in the opposite direction of the arrow F. During this movement of withdrawal of the injection device, the distal face 3a thereof being held in adhesion. with the skin of the patient, the nut 21 is brought back so that the tabs 14 are then released and return to their initial position.

[0071] The withdrawal movement takes place until the proximal face 25a of the stop 25 comes into contact with the boss 14a and the latter falls into the free space between the two stops 25 and 26 as shown in the FIGS. 5 and 5a.

[0072] Consequently, any relative movement of the cap 19 with respect to the body 3 in the direction of arrow F or in the opposite direction is no longer possible and the injection device is thus locked and secured against any subsequent use.

[0073] It is understood under these conditions that it is the second function exerted by the means for bonding the distal end of the injection device to the patient's skin which has the effect of controlling the actuation of the safety device during the withdrawal phase.

[0074] Such an arrangement is particularly advantageous for several reasons.

[0075] Firstly, it makes it possible to produce a safety injection device in a particularly simple manner compared to the prior devices of the state of the art which make use of complex mechanisms and which, consequently, are particularly difficult to manufacture. which makes them more expensive.

[0076] Secondly, this arrangement makes it possible to trigger the means capable of ensuring the safety of the injection device by a withdrawal movement thereof, unlike previous devices in which the safety is obtained by a pressure movement on the patient's body that occurs in an area near the injection site. However, we know that this kind of pressure is likely to cause the risk of bleeding or bruising.

[0077] By continuing the withdrawal movement, the user ensures the detachment of the distal face of the injection device from the surface of the patient's skin thanks to the blocking of the body 3 with respect to the cap 19 against the second distal stop 26.

[0078] Of course, although the present example is described with respect to a small volume syringe, in particular of the insulin type, it can be adapted to any other device using standard or non-standard syringes or cartridges, either according to a rotation-controlled injection mode as described in the present example or according to translation-controlled injection modes with conventional syringes using smooth plunger rods and finger supports.

[0079] In such a version with a smooth plunger rod actuated in translation, the cap 19 could be replaced by two arms also integral with the plunger rod. These two arms could circulate in two windows inside the finger support.

[0080] As for the screw version, the needle would be implanted by pushing these two arms in the direction of arrow F.

[0081] Moreover, the safety means implemented in the present injection device also have the advantage of being able to replace the cap which usually covers the injection needle. This eliminates an operation of removing the cap which is dangerous because it exposes the user to the cutting bevel, and also it can damage the injection needle and that finally it involves risks of external contaminations of this needle before it is injected.

[0082] In an alternative embodiment of the invention and as shown in FIG. 10, the body 3 may include a window 28 which will extend along the syringe and which will make it possible to check its contents before use.

[0083] Furthermore, and according to the invention, a label may connect the body 3 to the cap 19 so as to ensure the relative retention of these two parts before the injection. Such a label will also allow to verify the integrity of the injection device seal before use. This label may include a precut line promoting its breakage during injection.

[0084] Of course, the passive injection device with automatic safety according to the invention is not limited to the mechanisms described above and could be applied to any other type of mechanism in which the function of triggering the safety means would be ensured by gluing its distal part to the patient's skin.

[0085] The present invention could for example be applied in particular to an injection device in which the injection would be carried out not by rotation, as described above, but by translation.

[0086] FIGS. 6 to 9 show such an injection device for which the notations and references used in the previous example will be kept.

[0087] This injection device has the following essential differences with the previous device.

[0088] First of all, it comprises a plunger rod 17′ which consists of a smooth, unthreaded rod which is slidably mounted in an axial bore of a drawer 21′ with a level of friction f.sub.1. The drawer 21′ is mounted in the cap 19 so that it can move in translation with the lowest possible friction level f.sub.0.

[0089] This drawer has at its proximal end a circular groove 23 of the same type as that of the nut 21 of the previous example.

[0090] Under these conditions, the operation of the injection device according to the invention is established as described below.

[0091] As before, and as shown in FIG. 6, after removing the protective film 27, the user brings the adhesive distal end of the injection device into contact with the area of the patient's body, where he wishes to perform the injection. Therefore this end of the injection device, due to its adhesion with the injection zone, is stabilized.

[0092] Then, starting from the rest position shown in FIG. 6 and as shown in FIG. 7, the user exerts a linear thrust on the cap 19 in the direction of arrow F. It will also be noted that one will do so that the level of friction f.sub.1 is greater than the level of friction f.sub.2 necessary for the deformation of the tabs 14 by the circular groove 23 of the drawer 21′ plus the level of friction f.sub.3 between the O-ring 12 and the body of the syringe 9. We will thus have: f.sub.1>f.sub.2+f.sub.3

[0093] Under these conditions, the translational movement exerted on the cap 19 has the first effect of causing the injection needle 11 to come out of the injection device and to introduce it into the body 4 of the patient, as shown in FIG. 7. On the other hand, at the end of this translational movement, the bevels 14b of the tabs 14 penetrate into the groove 23 of the drawer 21′, which has the effect of deforming the tabs 14 inwardly as was the case in the previous example.

[0094] The injection device is therefore ready to proceed with the injection of the treatment product.

[0095] To do this, the user continues his axial displacement movement in the direction of arrow F so that the plunger 16 moves in the syringe 9 and administers the treatment product in the patient's body until the plunger reaches the neck of the syringe 9, as shown in FIG. 8, or that the user stops his injection.

[0096] Once the injection has been carried out, the user pulls on the cap 19 in the opposite direction to the arrow F. From then on, the injection means are made safe as described above.