DEVICE FOR INJECTING A PRODUCT

Abstract

The invention relates to a device (1) for injecting a product into a site, comprising: - a body (2) provided with a bearing wall (19) for bearing on the site, - a needle support (24) mounted so as to be movable with respect to the bearing wall (19) between: • a pre-insertion position, • at least one insertion position, and • at least one retracted position, - a catheter (30) mounted so as to be movable with respect to the needle (21) and intended for delivering product into the site, - drive means (4, 44) intended for translating the needle support (24) between the various positions of the needle support (24), - a pump (14) connected to a reservoir so as to transfer product from the reservoir to the catheter (30), - a single electric motor (13) intended for driving the drive means (4, 44) and for supplying the pump (14).

Description

[0001] Description

[0002] Title of the invention: Device for injecting a product

[0003] The invention relates to a device for injecting a product into a site. More particularly, the invention relates to a device for inserting a needle to distribute a product into the site where the needle was inserted, notably by means of a catheter (or cannula).

[0004] The technology is already known, notably from document WO2015164645, for a device for inserting a needle for catheter (or cannula) insertion to deliver medication. The device includes a torsion spring that allows vertical translational movement of a needle holder when the spring transitions from a compressed to a relaxed state. The device also includes a pump system, independent of the torsion spring, for dispensing the medication from a reservoir. Furthermore, the use of a spring or any other pre-loaded drive element in this type of device is prone to wear on the plastic parts with which it interacts. Due to the robustness required to prevent unintentional activation, this use can also lead to assembly and / or operational difficulties, for example, regarding the reproducibility of movements.

[0005] Indeed, a connecting element must first be assembled with the needle holder, and then the assembly is mounted on the base, taking care to compress the torsion spring against a stop on the base and insert a drive pin into a cam track. This involves several assembly constraints. Furthermore, the needle insertion and medication delivery are controlled independently, requiring more components in the insertion device, which has a significant footprint.

[0006] The invention aims in particular to remedy the disadvantages mentioned above and to provide a more compact and easier to assemble injection device.

[0007] To this end, the invention relates to a device for injecting a product into a site comprising: a body provided with a support wall on the site, a needle holder on which a needle is mounted, the needle holder being mounted movable relative to the support wall between:

[0008] • a pre-insertion position in which the needle is recessed relative to the supporting wall, • at least one insertion position in which the needle protrudes relative to the supporting wall, and

[0009] • at least one retracted position in which the needle is again withdrawn from the support wall, a catheter mounted movable relative to the needle and intended to distribute product into the site, drive means intended to drive the needle holder in a translational movement between the different positions of the needle holder, a pump connected to a reservoir so as to transfer product from the reservoir to the catheter, a single electric motor intended to drive the drive means and to power the pump for the transfer of the product.

[0010] The injection device as proposed by the present invention thus requires only one motor, which performs both needle insertion and product injection. This reduces the size of the injection device and manufacturing cost. Assembly is simplified by the reduced number of parts. In particular, there is no need for a specific return mechanism to actuate the needle insertion, thereby reducing the number of parts subject to wear. Furthermore, the control of the needle and catheter insertion movement is more precise and easier thanks to the electric motor drive.

[0011] Depending on other optional features of the injection device, taken alone or in combination:

[0012] - The electric motor is configured to:

[0013] • rotate in a first direction of rotation so that the drive means drive the needle support towards at least one insertion position;

[0014] • turn in a second direction of rotation so that the pump is put into operation in order to transfer product from the reservoir to the catheter, and preferably so that the drive means drive the needle holder to at least one retracted position, preferably simultaneously.

[0015] Thus, the various functions performed by the single electric motor are achieved simply by changing the direction of its rotation, which is easy to control. The second direction of rotation is the opposite to the first. The fact that needle retraction and product dispensing occur simultaneously makes the injection device even more efficient. The drive means comprise a series of teeth arranged around the circumference of a rotating element of the electric motor and designed to cooperate with a rack carried by at least the needle support or a complementary drive element, preferably configured to be linked in translation with the needle support.

[0016] Thanks to the cooperation of the teeth with the rack, the rotation of the rotating element is easily transformed into translation of the needle support, particularly during the insertion and retraction of the needle.

[0017] It is understood that the rack can be supported exclusively by the needle support (for example, the auxiliary drive element and the needle support are a single unit), thus saving a part. The auxiliary drive element can also be a separate component from the needle support, in which case the use of such an auxiliary drive element, which is in direct contact with the rotating element, allows for various shapes of the needle support to meet any layout or space constraints of the injection molding device. Finally, the needle support and the auxiliary drive element can simultaneously incorporate surfaces that make up the rack, allowing for more precise control of the movements of these elements within the injection molding device.

[0018] - The injection device includes a catheter holder capable of moving the catheter with the needle when the needle holder passes from its pre-insertion position to at least one insertion position and of disengaging it from the needle so that it remains locked in motion when the needle holder passes from its insertion position to at least one retracted position.

[0019] - The injection device includes a locking means configured to cooperate with notches carried by the catheter holder in order to lock the catheter holder in motion and define at least a first and a second insertion positions of the needle holder.

[0020] The locking mechanism and notches allow the catheter holder to be locked in at least two different positions relative to the support wall, corresponding to at least two different needle holder insertion positions. The ability to vary the needle holder insertion positions is particularly useful for adjusting the injection depth, thus adapting the injection to variables such as the user's body size or the desired injection type.

[0021] - The catheter holder and the complementary drive element are configured to be: • linked in translation during the movement of the needle holder from its pre-insertion position to at least one insertion position, and

[0022] • mobile relative to each other during the movement of the needle support from at least one insertion position to at least one retracted position.

[0023] - The injection device includes an elastic element carried by the catheter support or the complementary drive element, the elastic element being configured to keep the complementary drive element in contact with the drive means when the electric motor rotates in the second direction of rotation before needle insertion.

[0024] The use of such an elastic element enables a priming function, which purges air from the reservoir or upstream of the catheter, thus bringing the product into the catheter. Indeed, when the motor rotates in the second direction, during normal operation (outside of priming), the drive means move the needle holder to at least one retracted position relative to the catheter holder.

[0025] Thanks to the elastic element, the rack can be secured to the catheter holder during priming, before the needle and catheter are inserted into the patient's body. Similarly, the elastic element provides an additional, indirect connection between the catheter holder and the needle holder.

[0026] This configuration cleverly allows for a single motor to perform the functions of needle insertion, product transfer, and device priming. Advantageously, a stop interacts with the elastic element to maintain the rack's interaction with the drive means. The elastic element and the stop no longer interact during the rack and needle holder's retraction after insertion. Advantageously, the elastic element also holds the entire assembly (rack, catheter holder, and needle holder) securely during handling steps of the injection device (storage, transport, and priming).

[0027] The injection device comprises a base with a guide housing defining a guide axis and intended to receive a needle holder. The needle holder includes locking means configured to cooperate with additional locking means carried by the guide housing when the needle holder is in the pre-insertion position and in at least one retracted position. The locking means and the additional locking means ensure that the needle is held in place during injection and that the needle is stable when the needle holder is not in motion, i.e., before insertion (including during priming) and after catheter insertion.

[0028] - The supplementary drive element is configured to be linked in translation with the needle support only during the movement of the needle support.

[0029] • from its position before insertion to at least one insertion position, and

[0030] • from at least one insertion position to at least one retracted position, the additional drive element being mobile relative to the needle holder when the needle holder is in the pre-insertion position or in at least one retracted position.

[0031] This allows the rotation of the drive means during priming and injection, making the additional drive element not limited in movement by the needle support.

[0032] - The additional drive element includes a flexible portion carrying the rack, preferably the flexible portion has an arched shape.

[0033] This architecture and shape of the supplementary drive element allows for a horizontal arrangement of the supplementary drive element before and after needle insertion in order to further reduce the size of the injection device.

[0034] - The drive means include a first series of teeth arranged around the perimeter of a rotating element and intended to cooperate with a second series of teeth carried by a complementary rotating element provided with a cam track configured to guide the needle support in translation.

[0035] This arrangement allows for a reduction in the size of the injection device.

[0036] The invention also relates to an assembly kit for a product injection device at a site, comprising: a body provided with a support wall on the site, a needle support, the needle support being mounted movable relative to the support wall between:

[0037] • a pre-insertion position in which the needle is recessed relative to the supporting wall,

[0038] • at least one insertion position in which the needle protrudes relative to the supporting wall, and

[0039] • at least one retracted position in which the needle is again withdrawn from the support wall, a catheter configured to be mobile relative to the needle and intended to deliver product into the site, drive means intended to move the needle holder in a translational motion between the different positions of the needle holder, a pump connected to a reservoir so as to transfer product from the reservoir to the catheter,

[0040] - a single electric motor intended to drive the drive means and to power the pump for transferring the product.

[0041] Brief description of the figures

[0042] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings in which:

[0043] [Fig. 1] Figure 1 is a partial perspective view of an injection device according to one embodiment of the invention;

[0044] [Fig. 2] Figure 2 is an exploded view of a subset of the injection device of Figure 1;

[0045] [Fig. 3] Figure 3 is a set of perspective views (figures 3a-3e) illustrating different stages of operation of the subset of the injection device of figure 2 in interaction with drive means;

[0046] [Fig. 4] Figure 4 is a set of cross-sectional and perspective views (figures 4a-4e) illustrating the operating steps of the subassembly of the injection device of figure 3.

[0047] Detailed description

[0048] Figures 1 to 4 illustrate an injection device according to an embodiment of the invention, designated by the general reference numeral 1. As seen in Figure 1, the injection device 1 comprises a body 2 having a support wall 19 intended to be positioned in direct contact with the patient's skin. The injection device 1 is configured to deliver an injection of a product, preferably a liquid, generally a drug, to a site on the patient over a relatively long period, typically several minutes or even several hours.

[0049] Examples of pharmaceutical products that may be used in the delivery device include peptides, proteins, hormones, biologically derived active ingredients, nucleotide-based active ingredients, nutritional formulas, and other substances. These active ingredients may include, but are not limited to, insulins, insulin analogs such as insulin lispro or insulin glargine, insulin derivatives, C-peptide, GLP-1 receptor agonists such as dulaglutide or liraglutide, glucagon, glucagon analogs, glucagon derivatives, gastric inhibitory polypeptides (GIP), GIP analogs, GIP derivatives, oxyntomodulin analogs, oxyntomodulin derivatives, therapeutic antibodies such as monoclonal antibodies, and any therapeutic agent that can be delivered by the above-mentioned device.The drug as used in the device may be formulated with one or more excipients.

[0050] The injection device 1 can for this purpose be worn by the user during the injection, for example on the waist.

[0051] The injection device 1 further includes, as can still be seen in figure 1, an electric motor 13 comprising a shaft on which are mounted drive means 4, 44 which consist, in the illustrated example, of a rotating element 4 provided with a series of teeth 44 distributed uniformly around the periphery of the rotating element 4. The electric motor 13 is capable of rotating in a first direction of rotation S1 (see for example figure 3c) and a second direction of rotation S2 (see for example figure 3d).

[0052] The injection device 1 further includes a pump 14, for example a peristaltic pump as illustrated in Figure 1, mounted coaxially with the rotating element 4 and driven by the same electric motor 13. The pump 14 is connected to a product reservoir 7 by means of a flexible tube 6 so that, when the pump 14 is switched on, product is transferred from the reservoir 7 to an injection unit 10, which will be described later. Figure 1 is a partial view of the injection device 1, as the latter may include a cover or housing to form an enclosed space with the support wall 19 in order to render the elements described above invisible or inaccessible from outside the injection device 1.

[0053] Figure 2 illustrates a subset of the injection device 1, which is an injection unit 10. The injection unit 10 comprises a base 22 including a first vertical guide 221 and a second vertical guide 222 forming a guide housing 23 defining a guide axis (B). The first vertical guide 221 and the second vertical guide 222 are mounted rigidly to each other, for example by means of clips 223. The guide axis (B) can be provided substantially perpendicular to the support wall 19 or at any suitable inclination. Furthermore, the base 22 includes, on the first vertical guide 221, a through opening 224 having a longitudinal shape along the guide axis (B). The base 22 also includes a locking means 51 carried by the second vertical guide 222 near the support wall 19. The function of the various elements carried by the base 22 is described later.

[0054] As seen in Figure 2, the injection unit 10 includes a needle holder 24 mounted movably in the guide housing 23 between different positions as illustrated in Figures 3 and 4. The needle holder 24 includes a main block 240 with a substantially cross-shaped cross-section in a plane parallel to the support wall 19.

[0055] Furthermore, the main block 240 has a shape substantially complementary to that of the guide housing 23, so that the needle support 24 can slide in the guide housing 23 along the guide axis (B).

[0056] The needle support 24 further includes a locking means 25, in the form of an elastic hook 251 mounted on a flexible portion, the locking means 25 being configured to cooperate with complementary locking means 26 comprising a first vertical stop 261 and a second vertical stop 262 carried by the base 22, the cooperation between the locking means 25 and the complementary locking means 26 being more clearly visible in figure 4.

[0057] As shown in Figures 2 to 4, the needle holder 24 further includes a protrusion 241 designed to pass through and slide within the longitudinal through-hole 224. The protrusion 241 is designed to be connected to the tubing 6, as illustrated in Figure 1, to establish fluidic communication with the reservoir 7 and the product it contains. To this end, the protrusion 241 is provided with a distribution channel 242, as illustrated in Figure 4, which allows product to pass into the needle holder 24. An insertion needle 21 is fixed to the needle holder 24 and has a lateral orifice in fluidic communication with the distribution channel 242, thus allowing the product to be injected to reach the insertion tip 2T and therefore the injection site once the needle 21 is inserted.

[0058] According to the invention, the needle support 24 is mounted movable relative to the support wall 19 between:

[0059] • a pre-insertion position in which the needle 21 is recessed relative to the support wall 19,

[0060] • at least one insertion position in which the needle 21 is prominent relative to the support wall 19, and

[0061] • at least one retracted position in which the needle 21 is again withdrawn from the support wall 19. To achieve this, the injection unit 10 includes an additional drive element 3 (see, for example, Figure 2) for driving the needle holder 24 in a translational movement between the different positions of the needle holder 24. As shown in Figures 2 to 4, the additional drive element 3 has an L-shape and comprises a first horizontal portion 34, i.e., extending along an axis perpendicular to the guide axis (B), and a second vertical portion 35, i.e., extending along an axis parallel to the guide axis (B). The first portion 34 has a flat surface, as shown in Figure 4, for contacting the needle holder 24 and driving the needle holder 24 in motion.The first portion 34 further includes a locking pin 36 (see for example figure 3a) arranged at one end of the first portion 34 opposite the second portion 35. The second portion 35 is provided with a rack 33 (see for example figure 2) intended to cooperate with the series of teeth 44 on the rotating element 4 so that the complementary drive element 3 can be driven in translational motion about the guide axis (B) in both directions opposite to each other and in the first and second directions of rotation S1, S2 of the electric motor 13.

[0062] The injection unit 10 further includes a catheter 30 carried by a catheter support 31, as seen in Figures 2 to 4. In the illustrated example, particularly in Figures 2 and 3, the catheter support 31 includes an elastic element 32 having an arc shape, one end of which is fixed to the catheter support 31 and the other end forms a stop intended to cooperate with the locking pin 36 to maintain the rack 33 in interaction with the series of teeth 44. Advantageously, the elastic element 32 and the locking pin 36 are no longer in interaction during the ascent of the rack 33 and the needle support 24 after insertion of the needle 21 and rotation of the electric motor 13 in the second direction of rotation S2 (see Figures 3d and 3e).

[0063] The catheter support 31 is linked in translation to the needle support 24 during the insertion of the needle 21. The catheter 30 is mounted mobile relative to the needle 21.

[0064] Similarly, since needle 21 is housed inside catheter 30, inserting needle 21 into the site allows for the simultaneous insertion of catheter 30.

[0065] Figures 3 and 4 illustrate the different operating stages of the injection device 1, which will be described as follows: when the injection device 1 is ready for use by a patient or a healthcare professional, the needle holder 24 is in a pre-insertion position in which the needle 21 is retracted relative to the support wall 19. The needle holder 21 is held in this pre-insertion position by the interaction between the locking means 25, here in the form of an elastic hook 251, and the additional locking means 26 (Figures 3a and 4a). The catheter holder 31 and the additional drive element 3 are also held in this pre-insertion position because they are respectively abutted against the needle holder 21 on one side and blocked from translation by the interaction between the elastic element 32 and the locking pin 36 carried by the additional drive element 3 on the other.

[0066] When the user positions the injection device 1 at an injection site, the support wall 19 is, for example, in direct contact with the site. The user then activates the electric motor 13, for example by means of a control button, to rotate the electric motor 13 and the rotating element 4 in the second direction of rotation S2, as shown in Figures 3b and 4b. The injection device 1 is then in the priming phase, during which the pump 14 begins to transfer product from the reservoir to the catheter 30, successively via the tube 6, the pump 13, and the needle 21. This priming phase is programmed to last for a short period of time, but sufficient to purge any air present upstream of the catheter 30.

[0067] During the initiation phase, the series of teeth 44 carried by the rotating element 4 being in contact with the rack 33 carried by the complementary drive element 3 drives the latter in an upward direction relative to the guide axis (B), i.e. in a direction opposite to the support wall 19. Simultaneously, the elastic element 32 applies a force on the pin 36 downwards, i.e. in a downward direction relative to the guide axis (B) and therefore towards the support wall 19.

[0068] Thus, the complementary drive element 3 exerts a very small reciprocating movement which allows the complementary drive element 3 to remain in interaction with the series of teeth 44 of the rotating element 4. The complementary drive element 3 is thus brought back to the drive exerted via the rotation of the rotating element 4 in the second direction of rotation S2 and thus continue the priming phase of the injection device 1.

[0069] At the end of the priming phase of the injection device 1, the electric motor 13 rotates in a first direction of rotation S1, which is opposite to the second direction of rotation S2, to drive the needle holder 24 towards a predetermined insertion position. More precisely, the series of teeth 44 mesh with the rack 33 and transforms the rotation of the rotating element 4 into a translation of the complementary drive element 3 towards the support wall 19. The complementary drive element 3 itself drives the needle holder 24 as well as the catheter holder 31 in the same direction towards the support wall 19, as shown in Figures 3c and 4c.When the needle support 24 moves out of its pre-insertion position and towards the support wall 19, the locking means 25 are no longer interacting with the complementary locking means 26, because the locking means 25 include an elastic hook 251 which is completely constrained in the guide housing 23 as illustrated by Figure 4c.

[0070] When the needle holder 24 approaches the support wall 19, the notches 52 on the catheter holder 31 begin to engage with the locking means 51 one after the other. If the needle holder 24 reaches the predetermined insertion position, the corresponding notch already in contact with the locking means 51 continues to cooperate with the locking means 51 to hold the catheter holder 31 in position. If the needle holder 24 has not reached the predetermined insertion position, the rack 33 continues to move until the needle holder 24 reaches the predetermined insertion position.

[0071] Figures 4c to 4e illustrate an insertion position in which the last notch that contacts the locking means 51 cooperates with them to hold the catheter holder 31 in a position corresponding to a "shallow" insertion position of the needle 21, equivalent, for example, to the subcutaneous layer of the patient's skin. According to the example shown, the needle holder 24 can have up to 5 different insertion positions.

[0072] Once the catheter 30 is inserted into the site using the needle insertion device 21, the needle holder 24 disengages from the catheter holder 31 and moves from its insertion position to its retracted position. To achieve this, the electric motor 13 rotates again in the second direction of rotation S2 so that the drive means 4, 44 drive the auxiliary drive element 3 and the needle holder 24 upwards relative to the guide axis (B), towards the retracted position of the needle holder 24. Since the driving force of the electric motor 13 is greater than the engagement between the notches 52 and the locking means 51, the interaction between the elastic element 32 and the locking pin 36 is broken, and the auxiliary drive element 3 disengages from the catheter holder 31.The needle support 24 is linked in translation with the complementary drive element 3 by means of the hook formed by the locking means 25 via the elastic hook 251 on the first horizontal portion 34 of the complementary drive element 3.

[0073] During the withdrawal of the needle 21, the electric motor 13 rotates in the second direction of rotation S2, thus activating the pump 14, which transfers a predetermined quantity of the product from the reservoir 7 to the catheter 30. When the needle holder 24 reaches the retracted position, the elastic hook 251 and the additional locking means 26 cooperate again to lock the needle holder 24 in this retracted position, as shown in Figures 3d and 4d. Since the elastic hook 251 is no longer in contact with the first horizontal portion 34 of the additional drive element 3, the latter becomes mobile relative to the needle holder 24. The needle holder 24 is then stable in the retracted position where it is held. Thus, the electric motor 13 is able to continue rotating in the second direction of rotation S2 to complete the transfer of the predetermined quantity of the product.

[0074] The assembly of the injection device 1 is, for example, carried out using an assembly kit comprising: a body 2 provided with a support wall 19 on site, a needle support 24, the needle support 24 being mounted movable relative to the support wall 19 between:

[0075] • a pre-insertion position in which the needle 21 is recessed relative to the support wall 19,

[0076] • at least one insertion position in which the needle 21 is prominent relative to the support wall 19, and

[0077] • at least one retracted position in which the needle 21 is again withdrawn from the support wall 19, a catheter 30 configured to be mobile relative to the needle 21 and intended to distribute product into the site, drive means 4, 44 intended to drive the needle holder 24 in a translational movement between the different positions of the needle holder 24, a pump 14 connected to a reservoir so as to transfer product from the reservoir to the catheter 30, a single electric motor 13 intended to drive the drive means 4, 44 and to power the pump 14 for the transfer of the product.

[0078] The invention is not limited to the embodiments shown and other embodiments will be obvious to a person skilled in the art.

[0079] In particular, it is possible that the additional drive element 3 includes a flexible portion carrying the flexible rack 33, the flexible portion preferably having an arched shape.

[0080] It is also conceivable that the drive means include a first series of teeth arranged around the perimeter of a rotating element and intended to cooperate with a second series of teeth carried by a complementary rotating element provided with a cam track configured to guide the needle support 24 in translation.

Claims

Demands

1. A device (1) for injecting a product into a site comprising: a body (2) having a support wall (19) on the site, a needle holder (24) on which a needle (21) is mounted, the needle holder (24) being mounted movable relative to the support wall (19) between: • a pre-insertion position in which the needle (21) is recessed relative to the support wall (19), • at least one insertion position in which the needle (21) is prominent relative to the supporting wall (19), and • at least one retracted position in which the needle (21) is again withdrawn from the support wall (19), a catheter (30) mounted movable relative to the needle (21) and intended to distribute product into the site, drive means (4, 44) intended to drive the needle holder (24) in a translational movement between the different positions of the needle holder (24), - a pump (14) connected to a reservoir so as to transfer product from the reservoir to the catheter (30), - a single electric motor (13) intended to drive the drive means (4, 44) and to power the pump (14) for transferring the product.

2. Injection device (1) according to the preceding claim in which the electric motor (13) is configured to: - rotate in a first direction of rotation (S1) so that the drive means (4, 44) drive the needle support (24) towards at least one insertion position; - rotate in a second direction of rotation (S2) so that the pump (14) is put into operation in order to transfer product from the reservoir to the catheter (30), and preferably so that the drive means (4,44) drive the needle holder (24) to at least one retracted position, preferably simultaneously.

3. Injection device (1) according to any one of the preceding claims in which the drive means (4, 44) comprise a series of teeth (44) arranged around the periphery of a rotating element (4) of the electric motor (13) and intended to cooperate with a rack (33) carried by at least the needle support (24) or a complementary drive element (3) preferably configured to be linked in translation with the needle support (24).

4. Injection device (1) according to any one of the preceding claims comprising a catheter holder (31) capable of moving the catheter (30) with the needle (21) when the needle holder (24) passes from its pre-insertion position to at least one insertion position and of disengaging it from the needle (21) so that it remains locked in motion when the needle holder (24) passes from at least one insertion position to at least one retracted position.

5. Injection device (1) according to the preceding claim comprising a locking means (51) configured to cooperate with notches (52) carried by the catheter holder (31) in order to lock the catheter holder (31) in motion and define at least a first and a second insertion positions of the needle holder (24).

6. Injection device (1) according to claims 3 and 4, wherein the catheter holder (31) and the complementary drive element (3) are configured to be: linked in translation during the movement of the needle holder (24) from its position before insertion to at least one insertion position, and movable relative to each other during the movement of the needle holder (24) from at least one insertion position to at least one retracted position.

7. An injection device (1) according to any one of claims 4 or 5 comprising an elastic element (32) carried by the catheter holder (31) or the supplementary drive element (3), the elastic element (32) being configured to maintain the supplementary drive element (3) in contact with the drive means (4, 44) when the electric motor (13) rotates in the second direction of rotation (S2) before insertion of the needle (21).

8. Injection device (1) according to any one of the preceding claims, comprising a base (22) having a guide housing (23) defining a guide axis (B) and intended to receive a needle holder (24), and in which the needle holder (24) includes locking means (25) configured to cooperate with complementary locking means (26) carried by the guide housing (23) when the needle holder (24) is in the pre-insertion position and in at least one retracted position.

9. Injection device (1) according to any one of the preceding claims combined with claim 3, wherein the additional drive element (3) is configured to be linked in translation with the needle holder (24) only during the movement of the needle holder (24) - from its position before insertion to at least one insertion position, and - from at least one insertion position to at least one retracted position, the additional drive element (3) being movable relative to the needle holder (24) when the needle holder (24) is in the position before insertion or in at least one retracted position.

10. Assembly kit for an injection device (1) for a product in a site comprising: a body (2) provided with a support wall (19) on the site, a needle holder (24), the needle holder (24) being mounted movable relative to the support wall (19) between: • a pre-insertion position in which the needle (21) is recessed relative to the support wall (19), • at least one insertion position in which the needle (21) is prominent relative to the supporting wall (19), and • at least one retracted position in which the needle (21) is again recessed relative to the support wall (19), - a catheter (30) configured to be mobile relative to the needle (21) and intended to distribute product within the site, drive means (4, 44) intended to drive the needle holder (24) in a translational movement between the different positions of the needle holder (24), - a pump (14) connected to a reservoir so as to transfer product from the reservoir to the catheter (30), - a single electric motor (13) intended to drive the drive means (4, 44) and to power the pump (14) for transferring the product.