Implant injection device provided with a rack and pinion transmission

The invention relates to the technical field of injecting one or more implants into the body of a patient.

Implant injection devices are known including a hollow needle attached to a housing receiving an implant. The implant is injected by means of a push rod, which pushes the implant through the hollow needle and beyond to allow injection of the implant into the body of a patient.

In particular document is known <patcit id="pcit0001" dnum="US20090281520A1"><text>US20090281520A1</text></patcit> an implant injection device in which the injection of the implant can be done by sliding support on a button, the button then being driven by the user in a direction substantially parallel to the direction of injection. Thus, before actuation, the push rod is retracted and the button is on the side of the proximal end of the device, that is to say the end opposite the injection end. When pressing the button by the user, the button slides in a direction substantially parallel to the direction of injection and drives the push rod, which pushes the implant and allows its injection.

However, such actuation sliding support does not easily allow the user to inject multiple implants. Indeed, this actuation is generally performed by the thumb of the user, which has a reduced stroke for actuation that is not sufficient to the stroke necessary for the injection of an implant of great length and / or for the successive injection of two or more implants. In addition, such an actuation does not make it possible to maintain high injection precision over a large stroke, and does not in particular make it possible to stop the injection when the injection of an implant is performed, for example to orient the needle. injection in another direction for a second implant so as not to inject over too long. Indeed, the risk of starting unwantedly the injection of an implant following the already injected implant exists with such an actuation. This is undesirable to ensure correct injection, especially to prevent rupture of at least one of the implants or injury to the patient.

Thus, given their type of actuation, these implant injection devices do not allow to easily inject a long implant or a plurality of implants.

The present invention aims in particular to provide an implant injection device, which can easily inject a long implant and / or a plurality of implants.

For this purpose, the subject of the invention is in particular an implant injection device, comprising:<ul id="ul0001" list-style="dash" compact="compact"><li>an injection needle,</li><li>a body for receiving at least one implant,</li><li>injection means, the injection means comprising:<ul id="ul0002" list-style="bullet" compact="compact"><li>a push rod, disposed upstream of the implant housed in the receiving body, extending longitudinally and configured to urge the implant through the injection needle between an initial position and a final position in which the implant is injected,</li><li>actuating means by a user, configured to actuate a displacement of the push rod from the initial position to the final position,</li></ul></li></ul>the actuating means comprising a rack-and-pinion transmission mechanism.

Thus, it is proposed to provide an easy implant injector to handle and assemble, achieving a pleasant motion transmission for a user. Indeed, by one or more movements of small amplitude, the user can actuate the push rod over a long length thanks to the rack transmission, allowing for example to inject a long implant or a plurality of implants.

It will be understood that a rack-and-pinion transmission mechanism preferably comprises a toothed rectilinear element cooperating with a toothed wheel, for transforming a rotational movement into a translation movement or vice versa.

The term "implant" is preferably intended to mean a pharmaceutical compound in the solid or semi-solid state, for example in the form of an encapsulated liquid, and / or an electronic component, for example an electronic chip that may be of RFID type. The term "patient" or "subject" is generally understood to mean a living being, for example a mammal, in particular a human being. The user is usually a different person than the patient, but it is possible that the user is the patient himself.

In the present description, it is understood that the distal direction designates the direction farthest from the fingers of a user, that is to say, the closest to the skin or the surface of a patient at the time of a injection, and the proximal direction refers to the direction opposite to the distal direction. In other words, it is considered that the distal direction and the distal direction are the direction and the direction that go to the "front" of the implant injection device, direction otherwise called injection direction. In particular, the distal end of a patch corresponds to the end on the side of the injection needle, and the proximal end is the opposite end. It will further be understood that the injection axis, bearing the direction of injection, corresponds to the axis of the implant injection device, defined by the axis of the injection needle.

It is therefore understood that the "downstream" direction is a direction opposite to the "upstream" direction and corresponds to the direction oriented in the direction of the distal end of the implant injection device, that is to say towards the injection site, towards the end configured to be in contact with the injection site of the implant. Thus, the "downstream" direction can also be called the injection direction.

It is understood that the terms "upstream" and "downstream" are relative to the distal and proximal directions, a downstream element being disposed further in the distal direction than an upstream element. The implant injection device may further comprise one or more of the following features, taken alone or in combination.

The rack-and-pinion transmission mechanism comprises a first rack element and a second rack-and-pinion element;<ul id="ul0003" list-style="bullet" compact="compact"><li>the first rack member being configured to be driven by the user and forming a first rack-and-rack connection with a pinion, the pinion including a first toothing cooperating with the first rack member,</li><li>the pinion comprising a second toothing cooperating with the second rack member configured to push the push rod from the initial position to the final position.</li></ul>

Thus, there is provided a rack transmission mechanism comprising a pinion and two rack elements, so as to allow a reduction of the movement of the user. In other words, by a sliding movement over a short length, driving the first rack member, the user can actuate the push rod over a large length, for example to inject a large implant or a plurality implants. Advantageously, the first toothing and the second toothing of the pinion are formed by a first gear wheel and a second gear wheel of the pinion gear, the first gear wheel having a diameter smaller than the diameter of the second gear wheel.<ul id="ul0004" list-style="dash" compact="compact"><li>The actuating means comprise an actuating button sliding in a direction substantially parallel to the longitudinal direction of the push rod, which is supported by the first rack member. Thus, the movement to be performed for the actuation of the implant injection device is particularly easy for a user, who can for example easily maintain the implant injection device with one hand and operate the push rod by means of the sliding actuating button, using the thumb of this hand.</li><li>The implant injection device includes means for indicating a position of the push rod to the user. Thus, the user easily controls the position of the push rod and can for example stop the actuation of the push rod based on the indication provided by the indicating means, which is particularly advantageous if the a position corresponding to the end of injection of a first implant is indicated. Indeed, it prevents the user that he can remove the implant injection device or change injection orientation to inject a second implant at the same depth as the first implant.</li><li>The indicating means comprise a first flexible tongue carried by a housing, and the rack-and-pinion transmission mechanism comprising at least one projection, such that when the rack-and-pinion transmission mechanism reaches a first predetermined position, the projection is abutment against the first flexible tongue so as to provide the user with a first sound and / or tactile indication. Thus, when the rack-and-pinion transmission mechanism reaches a first predetermined position, the user detects, with the aid of the particularly practical acoustic and / or tactile indication, that the rack-and-pinion transmission mechanism has reached this first predetermined position, which may for example correspond to a position in which an implant is injected. This makes it possible for example to indicate to the user to stop the injection when the injection of an implant is performed, for example so as not to inject over too long a depth or to orient the injection needle in a another direction for another subsequent implant as a second implant, so as not to inject on too long a depth.</li><li>The indicating means comprises a second flexible tongue carried by the housing, the second flexible tongue being configured to abut against the projection in a second predetermined position preceding the first predetermined position, such that when the rack transmission mechanism reaches a second predetermined position, the projection is in abutment against the second flexible tongue, and when the rack transmission mechanism exceeds the second predetermined position, the second flexible tongue passes the projection so as to provide the user with a second audible and / or tactile indication. Thus, when the rack-and-pinion transmission mechanism reaches a second predetermined position, which corresponds to a position preceding the first predetermined position, the user detects by means of the audible and / or tactile indication that the rack-and-pinion transmission mechanism has reached this second predetermined position, which may for example correspond to a position preceding a position in which an implant is injected. This allows for example to indicate to the user to slow the injection when the injection of an implant is close to being performed completely, so as not to inject over too long.</li><li>The first flexible tongue has a greater flexural strength than that of the second flexible tongue. Thus, the tactile and / or audible indication is different depending on whether the rack transmission mechanism has reached the second predetermined position or the first predetermined position. The second predetermined position may correspond to an intermediate actuating position in which an implant part is still to be injected, and the first predetermined position may correspond to an actuating position in which an implant is injected. It is then useful for the first flexible tongue to have a higher bending strength than the second flexible tongue, which allows the user to easily detect that the implant is injected, so as not to inject too much depth, or to orient the injection needle in another direction for another subsequent implant such as a second implant, so as not to inject over too long a depth.</li><li>The receiving body is adapted to receive a plurality of implants, the push rod, in the first predetermined position of the rack transmission mechanism, occupies a position in which an implant is injected. Thus, the user easily detects that the implant is injected, so as not to inject too much depth, or to guide the injection needle in another direction for another implant so as not to inject on a too long</li><li>The at least one protrusion includes a protruding tooth of a planar longitudinal surface of the rack transmission mechanism. Thus, the indication means are made in a particularly simple manner.</li><li>The implant injection device comprises a housing, the pinion being pivotally mounted on the housing. Thus, the rack-and-pinion transmission mechanism is made particularly simple.</li><li>The number of teeth of the first toothing is strictly less than the number of teeth of the second toothing. Thus, the demultiplication of the user's movement is performed in a particularly simple manner. In addition, for example, the number of teeth of the first toothing is between 5 and 15, preferably between 5 and 10, more preferably is close to or equal to 5; and / or the number of teeth of the second toothing is between 6 and 30, preferably between 16 and 25, more preferably close to or equal to 18.</li><li>The ratio of displacement of the second rack element relative to the displacement of the first rack element is between 2 and 10, preferably between 3 and 5, more preferably is close to or equal to 3.6. Thus, the reduction of the movement of the user is optimally achieved. Indeed, if the ratio of the displacement of the second rack member relative to the displacement of the first rack member is too great, the injection precision is affected, and if the ratio of the displacement of the second rack member relative to the displacement of the first rack member is too small, the amplitude of the movement to be performed for the actuation by the user is too important.</li><li>The implant injection device comprises locking means arranged to lock the push rod in its final position, in which position the push rod preferably projects towards the downstream direction beyond the end of the push rod. injection needle. Thus, the implant injection device is not reusable, making it possible to comply with the hygiene constraints relating to such an implant injection device. In addition, when in its final position, the push rod projects towards the downstream direction beyond the end of the injection needle, the push rod forms in this case a safety element for the end. injection needle, which can be beveled to facilitate stitching. The push rod then makes it possible to prevent the needle from exerting its stitching function, for example on a person or an object in the event of a fall of the implant injection device. Indeed, in the case of a fall or a support in the distal direction, the contact with the implant injection device is thus achieved by means of the push rod and not with the end of the injection needle.</li></ul>

The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the drawings in which:<ul id="ul0005" list-style="dash" compact="compact"><li>the <figref idref="f0001">figure 1</figref> is a perspective view of an implant injection device according to one embodiment, in storage configuration before injection;</li><li>the <figref idref="f0001">Figures 2 and 3</figref> are side and perspective views of a portion of the implant injection device of the <figref idref="f0001">figure 1</figref>in which the push rod is in an initial position;</li><li>the <figref idref="f0002">figure 4</figref> is a side view and in perspective of a part of the implant injection device of the <figref idref="f0001">figure 1</figref>wherein the push rod is in an intermediate position;</li><li>the <figref idref="f0002 f0003">Figures 5 to 7</figref> are side and perspective views of a portion of the implant injection device of the <figref idref="f0001">figure 1</figref>in which the push rod is in a final position.</li></ul>

As shown on the <figref idref="f0001">Figures 1 and 2</figref>, an implant injection device 1, comprises an injection needle 9 (visible on the <figref idref="f0001">figure 2</figref>) carried by a gripping case 7 and protected by a cap 3 (visible on the <figref idref="f0001">figure 1</figref>), a reception body 11 (visible on the <figref idref="f0001">figure 2</figref>), at least one implant, injection means 5 and a gripping housing 7.

The implant injection device 1 is configured to inject one or more implants into the body of a patient via the visible injection needle 9. Although in the following, the example is illustrated with two implants, the implant injection device 1 is also applicable to a single implant, or a number of implants greater than two, such as for example three, four, five, ten implants.

As shown on the <figref idref="f0001">figures 2</figref> and <figref idref="f0003">6</figref>, the injection needle 9 is hollow and is for example made of metal such as stainless steel. The injection needle 9 has a distal end beveled to facilitate its insertion into the body of the patient. The injection needle 9 carries a support member 13, which may be made of plastic material and is intended to limit the depth of insertion of the injection needle 9 in the body of the patient. The injection needle 9 is attached at its proximal end to the receiving body 11. It can be protected in the storage configuration by the cap 3.

The cap 3 is a protective cap of the injection needle 9, it is here assembled on the gripping housing 7, by snapping its proximal end on the gripping housing 7. However, other means of assembly are possible, for example by screwing. The cap 3 is in this example in the form of ogive, may be provided with reliefs so as to facilitate its grip.

The receiving body 11 is a receiving body of two implants. As illustrated on the<figref idref="f0001">figure 2</figref>, the receiving body 11 is generally tubular and / or frustoconical, and houses the implants in its internal space, so that the implants are oriented towards the end of the injection needle 9, facing the the proximal end of the injection needle 9. In other words, the receiving body 11 is disposed upstream of the injection needle 9, and is intended to receive the implants so that the implants are arranged upstream of the injection needle 9, in the injection direction of the injection needle 9. The receiving body 11 is configured to contain two implants, the two implants being arranged one behind the other, that is to say one in upstream of the other, according to the direction of injection. The receiving body 11 may have, at its distal end, an implant retaining means, such as a membrane or a small narrowing of its internal diameter, for the purpose of preventing the fall of an implant through the needle. injection 9, for example under the action of the Earth's gravity force. The receiving body 11 may alternatively comprise, at its distal end, a flexible implant retaining element having an orifice of a diameter smaller than that of the implants, which is configured to deform and allow the passage of implants to the implant. injection needle 9 during the injection. The receiving body 11 advantageously comprises a window 15 (visible on the<figref idref="f0001">figure 2</figref>). Thus, a user is able to visually detect, through the window 15, the presence of implants in the implant injection device 1 before performing the injection on a patient, after removal of the cap 3. Note that in this example, the injection needle 9 and the receiving body 11 are inserts relative to each other, nevertheless it would be conceivable that the injection needle 9 and the body of reception 11 form two parts of the same room, for example having come from matter. Furthermore, the receiving body 11 is attached at its proximal end to the gripping casing 7, for example by snapping its proximal end onto the gripping casing 7, as illustrated in FIG. <figref idref="f0001">figure 3</figref>. The receiving body 11 thus has a peripheral rib 16, which engages in a corresponding groove 18 carried by the gripping casing 7. However, other assembly means are possible, for example by screwing. Alternatively, the receiving body 11 could be made directly in the gripping housing 7, being integral with the latter. In this example, the receiving body 11 is made of a plastic material, possibly transparent.

In the illustrated example, the gripping case 7 is composed of several elements:<ul id="ul0006" list-style="dash" compact="compact"><li>an external part, composed of an external gripping element 17 (visible on the <figref idref="f0001">figure 1</figref>), of tubular general shape, and a distal plug 19 (visible on the <figref idref="f0003">figure 6</figref>), and</li><li>an inner part, composed of two support elements 21, 23 injection means 5 assembled together, namely a male support member 21 and a female support member 23 (visible on the <figref idref="f0001">figure 2</figref>).</li></ul>

In the state as seemed, the outer gripping member 17, the distal plug 19 and the two support members 21, 23 are held in position relative to each other. Thus, the two support elements 21, 23 are assembled by snap-fitting of pins 25 (visible on the<figref idref="f0001">figure 3</figref>) carried by the male support member 21 in tubular housings 27 (visible on the <figref idref="f0003">figure 7</figref>) in the assembled state, the distal plug 19 is in abutment against the distal end of the two support members 21, 23, and is connected to the outer member of the gripping 17 by latching protrusions 29, for example in the form of semi-cylindrical sections as illustrated in FIG. <figref idref="f0002">figure 5</figref>in a corresponding inner peripheral groove of the outer gripping element 17.

The injection means 5 make it possible to push the implant or implants through the injection needle 9 between an initial position and a final position in which the implant or implants are injected. As can be seen in particular on the<figref idref="f0001">figure 3</figref>, the injection means 5 comprise a push rod 31 and actuating means 33 by a user.

The push rod 31 is disposed upstream of the implants housed in the receiving body. The push rod 31 extends longitudinally and is configured to urge the implants through the injection needle 9 between an initial position and a final position in which the implants are injected.

The push rod 31 may be made of metal, for example steel, preferably stainless steel. The push rod 31 is disposed upstream of an implant which is itself the implant disposed the most upstream among the implants. . The push rod 31 is thus configured to push the implant, here the implants, through the injection needle 9 between an initial position and a final position. Thus, in the initial position of the push rod 31, the implants are housed in the receiving body 11, and in the final position of the push rod 31, the implants are passed through the injection needle 9 and are located a priori in the body of a patient.

The actuating means 33 by a user are configured to actuate a displacement of the push rod 31 from the initial position to the final position. The actuating means 33 comprise a rack transmission mechanism 35.

As can be seen on the <figref idref="f0001">figure 3</figref>, the rack-and-pinion transmission mechanism 35 includes a first rack member 37 and a second rack member 39.

The first rack member 37 is a rack and pinion member. It is thus configured to be driven by the user and forms a first rack-and-rack connection with a pinion 41.

As illustrated on the <figref idref="f0001">figure 3</figref>, the pinion 41 comprises a first toothing 43 cooperating with the first rack member 37, and the pinion 41 comprises a second toothing 45 cooperating with the second rack member 39 configured to push the push rod 31 from the initial position to the position final. The pinion 41 thus forms a second rack-and-rack connection with the second rack element 39. The first toothing 43 and the second toothing 45 of the pinion 41 are formed respectively by a first gear 43 and a second gear 45, the first gear 43 having a diameter smaller than the diameter of the second gear 45.

The number of teeth of the first toothing 43 is strictly less than the number of teeth of the second toothing 45, in order to achieve a reduction of the movement. For example, the number of teeth of the first toothing 43 is between 5 and 15, preferably between 5 and 10, more preferably is close to or equal to 5, and / or the number of teeth of the second toothing 45 is included. between 6 and 30, preferably between 16 and 25, more preferably close to or equal to 18. The number of teeth of the first toothing 43 and the number of teeth of the second toothing 45 are preferably chosen so that the ratio of the displacement of the second rack element 39 with respect to the displacement of the first rack element 37 is between 2 and 10, preferably between 3 and 5, more preferably close to or equal to 3.6.

The pinion 41 is pivotally mounted in the gripping housing 7. The pinion 41 comprises for this a pin at each of its ends, a pin being carried by the male support member 21, and a pin 46 being carried by the element of female support 23. The axis of rotation of the pinion 41 is substantially orthogonal to the longitudinal direction of the push rod 31, so that the movement of the second rack member 39 allows to push the push rod 31 from the initial position to the final position.

The first rack member 37 further supports an actuation button 47, which is configured to be driven directly by the user. The actuating button 47 is assembled on the first rack member 37, for example by snap-fastening. It is understood that the first rack member 37 is in one piece with the actuating button 47.

The actuating button 47 is slidably mounted in a direction substantially parallel to the longitudinal direction of the push rod 31. For this, the first rack member 37 and the assembly formed by the male support member 21 and the female support member 23 form a sliding connection between them, in the longitudinal direction of the push rod 31.

The second rack member 39 is a driven rack member. It is thus configured to be driven by the pinion 41 and forms a second rack-and-rack connection with the pinion 41. The second rack member 39 supports the push rod 31, the push rod 31 being for example fixed by clamping in a housing of the second rack member 39. Thus, when the second rack member 39 is driven, it pushes the push rod 31 in the injection direction from the initial position to the final position.

The second rack member 39 is slidably mounted in a direction substantially parallel to the longitudinal direction of the push rod 31. For this, the second rack member 39 and the assembly formed by the male support member 21 and the female support member 23 forms a slide connection therebetween, in the longitudinal direction of the push rod. Thus, when driven by the pinion 41, the second rack member 39 slides in the longitudinal direction of the push rod, causing the push rod 31 to move in the distal direction. The push rod 31 then pushes at least one implant through the injection needle 9. When the push rod 31 is in its final position, the second rack member 39 does not continue its course. The gripping housing 7 then forms, in particular through the male support member 21, a stop for the second rack member 39. Thus, the user can not inject an implant over too great a length that could injure the patient.

The implant injection device 1 also comprises means 51 for indicating a position of the push rod 31 to the user, as illustrated, for example, on the <figref idref="f0002">figure 4</figref>.

The indication means 51 here comprise a first flexible tongue 53 carried by the gripping housing 7, in particular by the male support element 21. The rack-and-pinion transmission mechanism 35 comprises at least one protrusion 55, so that when the rack-and-pinion transmission mechanism 35 reaches a first predetermined position, the projection 55 abuts against the first flexible tab 53 so as to provide the user a first sound and / or tactile indication. In the illustrated example, the push rod 31, in this first predetermined position of the rack transmission mechanism 35, occupies a position in which an implant is injected.

In the illustrated example, especially on the <figref idref="f0002">figure 4</figref>, the first flexible tongue 53 is supported by the male support member 21 of the gripping housing 7. The second rack member 39 supports two projections 55, each of which comprises a protruding tooth 57 of a longitudinal plane surface 59 of the gripping mechanism. Rack-and-pinion transmission 35. "Longitudinal surface" may include a surface extending substantially parallel to the longitudinal direction of push rod 31. In the example illustrated, the plane longitudinal surface 59 is carried by the second rack element 39.

When the rack transmission mechanism 35 reaches a first predetermined position, for example a position in which an implant is injected, even an intermediate position in which a first implant is injected and a second implant is not injected and is still in the implant injection device 1, as illustrated on the <figref idref="f0002">figure 4</figref>the protrusion 55 or tooth 57 is in abutment with the first flexible tongue 53. In the case of an intermediate position, in order to inject the second implant, the user must then exert a force to cause the deformation of the first flexible tongue 53 and allow the crossing by the first flexible tongue 53 of a protrusion 55 or tooth 57.

The indication means 51 comprise a second flexible tongue 61, carried by the gripping housing 7, in particular by the male support element 21.

The second flexible tongue 61 is configured to abut against a protrusion 55 or tooth 57 in a second predetermined position preceding the first predetermined position.

When the rack-and-pinion transmission mechanism 35 reaches a second predetermined position, for example a position in which an implant is partially injected, or even a position in which an implant is close to being injected in its entirety, the protrusion 55 or tooth 57 is located. abutting against the second flexible tongue 61, and when the rack-and-pinion transmission mechanism 35 exceeds the second predetermined position, the second flexible tongue 61 passes the projection 55 or tooth 57 so as to provide the user with a second audible and / or tactile indication. In this second predetermined position, in order to continue the injection of an implant, the user must then exert a force to cause the deformation of the second flexible tongue 61 and allow the crossing by the second flexible tongue 61 of a protrusion 55 or tooth 57.

The first flexible tongue 53 has a greater flexural strength than the second flexible tongue 61. Thus, the user easily distinguishes the first predetermined position from the second predetermined position. During injection of an implant, the second predetermined position will first be reached, indicating for example to the user the approach of the injection of the entire implant. Then, the first predetermined position is reached, indicating for example to the user injection of the entire implant. This may for example allow the user to reposition the implant injection device 1, in particular the injection needle 9, so as to begin the injection of another implant with a proper positioning.

In the illustrated example, the implant injection device 1 comprising two projections 55 or tooth 57, the rack transmission mechanism 35 can thus occupy two first predetermined positions, respectively two predetermined second positions. In particular, a first predetermined position and a second predetermined position are reached during the injection of each of the two implants.

The implant injection device 1 comprises locking means arranged to lock the push rod 31 in its final position, in which position the push rod 31 preferably projects towards the downstream direction beyond the end. of the injection needle 9.

In addition, the implant injection device 1 may comprise locking means arranged to lock the push rod 31 in the final position. Thus in this final position, a lug supported by the first rack member 37 or the second rack member 39 cooperates with a recess carried by the gripping housing 7, in particular formed in the male support member 21. Advantageously, the lug may be formed on the longitudinal surface 59 of the second rack member 39 and be in the form of a ramp terminating at its upstream end by a wall substantially orthogonal to the longitudinal surface, so that the crossing of this ramp by the first flexible tongue 53 or the second flexible tongue 61 generates a sound signal audible by the user, as a 'click'. In addition, the presence of the substantially orthogonal wall does not allow crossing the lug in the other direction, except for example to cause the rupture of the first flexible tongue 53 or the second flexible tongue 61. This simply avoids the reuse of the implant injection device 1 and also makes it possible to avoid injury due to the injection needle 9, for example in the event of a fall of the implant injection device 1 after use, thanks to the fact that the push rod 31 protrudes beyond the end of the injection needle 9 and is blocked by these locking means.

The elements of the implant injection device 1 whose material is not specified in the present description may be made of thermoplastic material, for example polyethylene or polypropylene.

An exemplary operation of the implant injection device 1 will now be described.

The implant injection device 1 as illustrated on the <figref idref="f0001">figure 1</figref> is in storage configuration, before use.

The user must remove the protection cap 3 from the injection needle 9, as illustrated on the <figref idref="f0001">figure 2</figref> - the implant injection device 1 being considered assembled - it checks the presence of the implant or implants by visualization through the window 15 of the receiving body 11.

The injection needle 9 is then pressed into the body of the patient, and the user slides on the actuating button 47. The actuating button 47 and the first rack member 37 then slide relative to the grip housing 7. The first rack member 37 then drives the pinion 41 in rotation through its first toothing 43. The rotation of the pinion 41, via its second toothing 45 in contact with the second rack member 39, causes the sliding of the second rack member 39. The second rack member 39 then pushes the push rod 31 into the rack. injection direction, from its initial position to its final position. The push rod 31 then pushes the implant or implants through the injection needle 9, so as to cause the injection of the implant (s) in the body of the patient.

Then, when the rack transmission mechanism 35 reaches a second predetermined position, for example a position in which an injection of an implant is nearing completion, the protrusion 55 or tooth 57 abuts against the second flexible tab. 61. The user, if he continues pressing the actuating button 47, must then exert a force so that the rack transmission mechanism 35 exceeds the second predetermined position. This causes a deformation of the second flexible tongue 61 and allows the second flexible tongue 61 to cross the projection 55 or tooth 57 so as to provide the user with a second sound indication, such as a 'click', and / or touch, due for example to the additional effort to be provided to cross the protrusion 55 or tooth 57.

After that, when the transmission mechanism reaches a first predetermined position, for example a position in which the push rod 31 occupies a position in which an implant is injected as illustrated in FIG. <figref idref="f0002">figure 4</figref>the protrusion 55 or tooth 57 is in abutment with the first flexible tongue 43. The user, if he continues pressing the actuating button 47, must exert a force so that the rack transmission mechanism 35 exceeds the first predetermined position. This causes a deformation of the first flexible tongue 53 and allows the first flexible tongue 53 to cross the projection 55 or tooth 57 so as to provide the user with a first sound indication, such as a 'click', and / or touch, due for example to the additional effort to be provided to cross the protrusion 55 or tooth 57.

For example, the first flexible tongue 53 has a higher flexural strength than the second flexible tongue 61, so that the user can easily distinguish whether the injection of an implant is nearing completion or if this implant is injected.

In the illustrated example, the second rack member 39 comprises two teeth 57, positioned one behind the other so as to correspond to the injection of a first implant and a second implant. Thus, the first tooth 57, positioned downstream relative to the second tooth 57, cooperates with the second tongue 61 and the first tongue 53 during the injection of a first implant, and the second tooth 57 cooperates with the second tongue 61 then the first tongue 53 when injecting a second implant.

Finally, when the push rod 31 reaches its final position, as illustrated on the <figref idref="f0002">figures 5</figref> and <figref idref="f0003">6</figref>, it protrudes downstream beyond the end of the injection needle 9. In this position, the male support member 21 forms a stop for the second rack member 39. position, the implants are all injected.

The invention is not limited to the embodiments presented and other embodiments will become apparent to those skilled in the art. Although the invention has been illustrated with an implant injection device 1 configured to inject two implants, those skilled in the art will readily understand that such an implant injection device 1 can be configured to inject a single implant. implant, for example with a long length, or a number of implants greater than two.