HK1114800B - Applicator for inserting an implant - Google Patents

Description

Manipulator for inserting an implant

The invention relates to an applicator for inserting an implant, in particular a rod-shaped implant containing an active substance, under the skin of a human or animal, comprising a housing, a cannula extending from the housing, and a handle for grasping and manipulating the applicator and the cannula during insertion of the implant.

Such manipulators are well known in the art.

EP0304107 discloses an injection device (designated by reference numeral 1), in particular for single use, for injecting an implant (6) which releases a drug in a controlled manner, which device comprises a housing (2) which is provided at the injection end with an injection needle (3), in which the implant (6) can be arranged and at the action end of which a passage opening is provided for a plunger (7, 8), which plunger (7, 8) is mounted in the housing and can be moved in the axial direction of the needle (3), which plunger can, on the one hand, co-operate with the implant (6) and, on the other hand, is provided with an actuator which is constructed as an element (10) for pressing against and supporting or resting on a part of the body to be treated.

It is an object of the present invention to provide an improved operator.

To this end, the invention provides an applicator for inserting an implant, in particular a rod-shaped implant containing an active substance, under the skin of a human or animal, the applicator comprising a housing, a cannula extending from the housing, and a handle for grasping and manipulating the applicator and the cannula during insertion of the implant, wherein the handle extends along at least part of the length of the cannula and is spaced therefrom at least during insertion of the cannula. Preferably the handle extends at least 30%, preferably at least 50%, along the length of the cannula extending from the housing and spaced therefrom.

Such a handle appears to facilitate insertion of the cannula and/or accurate positioning of the implant.

It is also convenient to insert the cannula at the appropriate angle if the handle extends at least 80% of the length of the cannula extending from the housing and is spaced therefrom.

In order to allow a gentle lifting of the skin when inserting (part of) the cannula, it is preferred to increase the width of the handle in a direction away from the cannula.

More preferably, the top surface of the handle is raised relative to the remainder of the housing. As a result, the medical professional entrusted with inserting the implant will more or less intuitively grasp the handle of the applicator.

Preferably, the applicator comprises a cannula holder and a lever extending along at least part of the cannula, the lever being rotatable and/or slidable and/or bendable between a first position, in which the implant is fixed within the cannula and/or the cannula holder, and a second position, in which the implant is disengaged. The advantages of such a lever will be discussed in detail below.

In order to reduce the risk of causing pain to the patient, it is preferred that the lever at least partially covers the cannula in its first position.

For the sake of completeness, it is noted that WO98/13092 discloses a tissue penetration guide (denoted by reference numeral 8) which limits the range of movement of the device (2) which can be used for insertion beneath and substantially parallel to the surface of a particular tissue (10) or superimposed on a series of tissues such that the insertion reaches a desired depth. The tissue infiltration guide according to WO98/13092 comprises a substantially linear, preferably linear, extension of material which remains substantially parallel, preferably parallel, to the projecting part of the device, which part is intended for the insertion described above, and is separate therefrom. The guide is used to maintain at or near the surface of the tissue to be accessed and to guide the insertable portion of the device or instrument to its intended insertion position. WO98/13091 discloses a similar osmotic guide. The guide in these publications is neither shown nor suitable for use as a handle.

US4,223,674 discloses an implant gun comprising: a handle or grip (10) slidably connected to the intermediate member (12); and a hollow needle (16).

EP596161 discloses an instrument for inserting a needle (2) under the skin of a living being. Guide means (4, 5) are provided on both sides of the needle.

US1,655,158 discloses an instrument for implanting radon tubules, which consists of three elements, an implanter (1), a trocar (2) and a plunger (3). The implanter comprises a tubular body portion (4) and a needle (5).

WO2004/089458 discloses a device for inserting implantable articles under the skin of a patient comprising a handle for grasping the device and a base connected to the handle. The base includes a post, a sleeve, and a flexible actuator located on an angled track.

WO01/68168 discloses a disposable device for inserting one or several implants, said device comprising: a tubular sleeve (10) provided with a tip (11), said sleeve also serving as a receptacle for the implant; a plunger (20); and a handle (30) having a first end (31) facing towards the cannula (10) and a second end (32) facing away from the cannula.

The invention will be explained in more detail with reference to the drawings, in which two preferred embodiments of the invention are schematically shown.

Fig. 1 is a perspective view of a first embodiment of the applicator of the present invention.

Fig. 2 is a perspective view of the same operator as in fig. 1, but with its protective cover removed.

Fig. 3 and 4 are top and cross-sectional side views, respectively, of the preferred applicator of fig. 1, with the cannula in an extended position.

Fig. 5 is a cross-sectional side view of the preferred applicator of fig. 1, with the cannula in a retracted position.

Fig. 6 is an exploded view of the preferred applicator of fig. 1.

Figure 7 is a perspective view of the protective cover.

Fig. 8 shows a top view, a cross-sectional view and a rear view of a lever for the preferred operator of fig. 1.

Fig. 9 is a perspective view of a second embodiment of the applicator of the present invention.

Fig. 10 is a cross-sectional side view of the preferred applicator of fig. 9, with the cannula in an extended position.

Fig. 11 is an exploded view of the preferred applicator of fig. 9.

Fig. 1 to 8 show a preferably disposable applicator 1 for inserting an implant 2, in particular a rod-shaped implant containing an active substance, such as a contraceptive, under the skin of a human body. The operator 1 includes: a housing 3, which housing 3 is composed of two half-shells 4, 5; a metal sleeve 6 for receiving the implant 2 (fig. 2); a protective cover 7 (fig. 1 and 4), the cover 7 comprising a pin 7A extending into the tip of the cannula 6 so as to limit the free movement of the implant 2; and an actuator 8 for retracting the sleeve 6 into the housing 3. The cannula 6 is fixed to a cannula holder 9 which is slidably accommodated within the housing 3. For this purpose, the inner wall of each of the half-shells 4, 5 is provided with two parallel and longitudinal guides 10 (fig. 6), and the cannula holder 9 is provided with corresponding longitudinal grooves 11. The cannula holder 9 is connected to the actuator 8 by means of a flexible element 12, which flexible element 12 is in this example integral with the cannula holder 9 and the actuator 8. Interconnecting the actuator with the cannula holder by means of a flexible element increases the freedom of choice for the operator designer of the position of the actuator. I.e. the actuator may be arranged at a convenient location during insertion of the implant.

However, depending on the configuration of the manipulator, it may be more advantageous to employ rigid elements and/or separate actuators, flexible elements and needle holders, which are all connected when the manipulator is assembled.

In fig. 6 it can be seen that the cannula holder 9 comprises a collar 13 at its front (distal) end, at the transition to the cannula 6, and a recess 14 on its bottom surface near its rear (proximal) end. These features will serve to lock the cannula holder and thus the cannula in the extended and retracted positions, respectively, as described below.

The housing 3 comprises a handle 15 for gripping and handling the cannula 6 during insertion. The handle 15 extends above the cannula 6, i.e. along the cannula 6 and spaced therefrom, preferably close to the distal end of the cannula 6. To further enhance the grip of the operator and the operating cannula, it is generally preferred that the thickness and/or bending stiffness of the handle is greater than the thickness and bending stiffness of the cannula, respectively.

In order to enable a gentle lifting of the skin when inserting (part of) the cannula, the width of the handle 15 is gradually increased in a direction away from the cannula 6. Handling and lifting can be further improved by providing the handle 15 with a surface portion having a higher coefficient of friction. Suitable materials for such surface portions include synthetic rubber, which is preferably co-injection molded with the material of the housing itself. The top surface of the handle 15 is raised relative to the rest of the housing 3. As a result, the medical professional entrusted with inserting the implant will more or less intuitively grasp the handle 15 of the applicator.

At the top of the handle 15, a track 16 is provided for guiding the actuator 8. A guide (not shown in this particular embodiment) may be included, preferably just below the track 16, to hold and guide the flexible element 12.

The bracket 17 is inserted into the rear end of the housing 3 and snap-fitted thereto by means of two resilient fingers 18, 19, each provided with a projection 18A, 19A. The lower finger 19 also comprises a wedge-shaped protrusion 20 near its end. The bracket 17 further comprises a rod 21 which extends through a larger part of the housing 3 and into the cannula holder 9 and the cannula 6. In this example, the length of the rod 21 is adjusted to the length of the lumen of the cannula holder 9 and the cannula 6 and the length of the implant 2 such that when the cannula 6 is in the extended position, the implant 2 is completely contained within the cannula 6 and generally abuts the distal end of the rod 21. When the cannula 6 is in the retracted position, the implant 2 is fully expelled from the cannula 6 and the distal end of the rod 21 extends from the distal end of the cannula 6 (retracted).

The lever 22 has been pivotally connected to the front end of the handle 15. The lever 22 is gently biased towards the cannula 6 by means of a metal spring (not shown) extending between the lever 22 and the inner wall of the handle 15. In this preferred embodiment, the lever 22 interacts with the protective cover 7, the implant 2 and the cannula holder 9. To this end, the lever 22 includes (from left to right in fig. 8) a first projection 23 on its lower wall, a pair of lateral projections 24 on its upper edge, and a vertically extending slot 25 on its rear wall.

The protective cover 7 (fig. 7) comprises on its inner wall a pair of ridges 26 which, in cooperation with corresponding slots 27 on the outside of the half-shells 4, 5, force a sliding engagement between the cover 7 and the housing 3. The lid 7 also comprises a pair of keys 28 at its upper edge, each key 28 being interrupted by a recess 29.

Finally, the cannula 6 comprises an opening 30 (fig. 6) which enables the protrusion 23 to engage the implant 2 and thereby gently push the implant 2 against the inner wall of the cannula 6.

With the protective cover 7 in place, the lateral projection 24 of the lever 22 is supported by the key 28, while the first projection 23 is just clear of the implant 2.

If the protective cover 7 is removed, i.e. slid in the longitudinal direction and away from the housing 3, the key 28 will slide under the lateral projection 24. If no implant 2 is present in the cannula 6, the protrusion 23 on the lever 22 is free to enter the cannula 6 through the opening 30. I.e. the lever 22 will fall when the lateral protrusion 24 reaches the recess 29, thereby preventing the cover 7 from being moved further, preventing it from being removed and preventing the operator from being used further. If there is an implant 2, the lever 22 will be lowered only slightly, while the lateral projections 24 remain clear of the recesses 29, and will also cause the first projections 23 to rest on the implant 2 through the openings 30, thus, on the one hand, allowing the cover 7 to be removed, and, on the other hand, gently pushing the implant 2 towards the inner wall of the cannula 6, i.e. securing the implant 2 within the cannula 6.

At this point, the practitioner can grasp the applicator 1 with one hand, for example, with the thumb on one side of the handle 15 and the fingers on the other side, and insert the cannula 6 under the patient's skin. During insertion, the handle 15 prevents the cannula from being inserted over an excessive angle on the one hand, and on the other hand enables the operator 1 and the cannula 6 to be operated in unison and carefully lift the skin in order to facilitate insertion of the implant 2 to the appropriate depth. The skin at the top of the cannula 6 lifts the lever 22 to such an extent that contact between the protrusion 23 and the implant 2 is eliminated, i.e. the implant 2 is disengaged without special action by the medical staff, and the slot 25 in the rear wall of the lever 22 leaves the collar 13 on the front of the cannula holder 9, thereby unlocking the cannula holder 9. Subsequently, the actuator 8 is unlocked and the cannula 6 is pulled backwards, for example with the index finger of the hand holding the applicator 1. During this rearward movement, the implant 2 abuts the distal end of the rod 21 and maintains its longitudinal position. Only limited friction forces are generated between the implant 2 and the inner wall of the cannula 6, while substantially no lateral forces are exerted on the implant 2. When the cannula holder 9 reaches the fully retracted position, the fingers 19 (part of the bracket 17) will bend downwards and the protrusions 20 on the fingers 19 will snap momentarily into the recesses 14 on the lower surface of the cannula holder 9, preferably with an audible click, indicating to the medical staff that the implant 2 has been inserted and that the applicator 1 can be removed and discarded. The projection 20 and the recess 14 likewise form a lock to prevent the operator 1 from being used again.

Figures 9 to 11 show a second embodiment of the manipulator of the invention. The main differences from the first embodiment will be discussed below. Those elements in the first embodiment which are at least substantially identical are denoted by the same reference numerals.

In the second embodiment, the housing 3 is composed of two side housings 4, 5 welded (ultrasonically) together and a single rear portion 3A, which rear portion 3A is snap-fitted to the side housings 4, 5. The handle 15 and the protective cover 7 are provided with reliefs (relief) on both sides, in this example in the form of projections 31, in order to enhance the grip and achieve a guiding (additional) action when gripping these respective parts 15, 7. A similar protrusion 31 has been provided on the (upper) edge of the actuator 8.

Further, the cover 7 includes a stay (stay)32 on its inner bottom wall, preferably a V-shaped groove extending in the longitudinal direction of the operator 1 on its top surface. Once the protective cover 7 is placed on the housing 4, 5, the stay 32 slightly lifts the sleeve 6 and reproducibly defines the lateral position and height of the tip of the sleeve 6 with respect to the pin 7A, thus preventing contact between the needle tip and the inner wall of the cover 7.

The flexible element 12 interconnecting the actuator 8 and the cannula holder 9 comprises lateral protrusions 33 preferably just below the actuator 8 and on either side of the flexible element 12. The inner walls of the housings 4, 5 in turn comprise two respective stops 34 which prevent the projection 33 from passing through and thus the actuator 8 from being inadvertently pulled backwards. The lateral projections 33 and the stops 34 also prevent the cannula holder 9 and the cannula 6 from being pushed towards the rear during insertion.

A guide 35 for holding and guiding the flexible element 12 is arranged just below the rail 16. The guide 35 is shaped to provide sufficient space under the actuator 8 to allow the element to flex sufficiently far down and to allow the lateral projection 33 to pass the stop 34 when the actuator 8 is pushed down. Thus, the cannula 6 can be retracted in one flow movement, i.e. upon application of pressure to the actuator 8, typically with an index finger, the actuator 8 flexes downwardly, away from the stop 34, and then moves rearwardly to the retracted position.

In contrast to the first embodiment, there is no collar (13) at the front (distal) end of the cannula holder 9. Instead, two resilient projections 36 are provided at the rear (proximal) end of the cannula holder 9. Two corresponding stops (not shown) are likewise included on the inner side walls of the housings 4, 5, which stops the rearward movement of the projection 33 and thereby defines the longitudinal position of the cannula holder 9 in the rearward direction. Preferably, the mechanism advances the cannula holder 9 to its most forward position, thereby preventing the implant 2 from protruding from the cannula 6. Once actuated, the tabs 33 will flex inwardly and past the stop.

As is apparent from the above description, the applicator of the present invention facilitates insertion of a cannula and/or precise positioning of an implant. The applicator according to the invention is therefore particularly suitable for implants which slowly release an active substance over a long period of time. A preferred example of such an implant is a single-rod contraceptive implant which prevents pregnancy over an extended period of time, for example 3 years. This implant consists of a non-biodegradable rod of length 40mm and diameter 2 mm. After insertion, the rod slowly releases the progesterone hormone, i.e. the estrogen (etonogestrel).

The invention is not limited to the embodiments described above, which can be varied in a number of ways within the scope of the claims. For example, the actuator may be provided on or within a side wall of the handle, rather than at the top of the handle.

Claims (22)

1. Applicator (1) for inserting an implant (2) under the skin of a human or animal, comprising a housing (3), a cannula (6) protruding from the housing (3) and a handle (15) for gripping and manipulating the applicator (1) and the cannula (6) during insertion of the implant (2), characterized in that the handle (15) extends along at least part of the length of the cannula (6) and is spaced apart therefrom at least during insertion of the cannula.

2. Applicator (1) according to claim 1, wherein the handle (15) extends along at least 30% of the length of the cannula and is spaced apart therefrom.

3. Applicator (1) according to claim 1, wherein the handle (15) extends along at least 50% of the length of the cannula and is spaced apart therefrom.

4. Applicator (1) according to claim 1, wherein the handle (15) extends along at least 80% of the length of the cannula and is spaced apart therefrom.

5. Applicator (1) according to claim 1 or 2, wherein the width of the handle (15) increases in a direction away from the cannula (6).

6. Operator (1) according to claim 1 or 2, wherein the top surface of the handle (15) is convex with respect to the rest of the housing (3).

7. Operator (1) according to claim 1 or 2, comprising a cannula holder (9), a rod (21) mounted on or in the housing (3) and at least partly inside the cannula (6) and/or the cannula holder (9), and an actuator (8), the actuator (8) being adapted to slide the cannula (6) and the rod (21) in relation to each other, wherein the actuator (8) is located on the handle (15).

8. Applicator (1) according to claim 7, wherein the actuator (8) is located above the cannula (6) when the cannula (6) has the implant (2) therein.

9. Applicator (1) according to claim 7, wherein the cannula holder (9) is provided at the proximal end of the cannula (6), which cannula holder (9) is slidable on the rod (21), and wherein the actuator (8) and the holder (9) are interconnected by a flexible element (12).

10. Manipulator (1) according to claim 9, wherein the flexible element (12) is at least partially retained by a guide.

11. Applicator (1) according to claim 1 or 2, comprising a lever (22) extending along at least part of the cannula (6), which lever (22) is rotatable and/or slidable and/or bendable between a first position, in which the implant (2) is fixed within the cannula (6) and/or the cannula holder (9), and a second position, in which the implant (2) is disengaged.

12. Operator (1) according to claim 11, wherein in its first position the lever (22) at least partially covers the sleeve (6).

13. An assembly of an implant for insertion beneath the skin of a human or animal and a manipulator including a housing, a cannula having a length extending from the housing, and a handle for grasping and manipulating the manipulator and cannula during insertion of the implant, characterised in that the handle extends along at least part of the length of the cannula and is spaced therefrom.

14. The assembly of claim 13, wherein the handle has a width in a direction away from the cannula and each side surface, the width enabling the handle to be grasped by a user.

15. The assembly of claim 13, wherein the handle has a bending stiffness greater than a bending stiffness of the cannula.

16. An assembly according to claim 13, wherein prior to use, the implant is gently urged towards the inner wall of the cannula by means of a projection bearing against the implant through an opening in the cannula so that the implant is located in the cannula and secured against inadvertent movement therefrom.

17. The assembly of claim 16, wherein the cannulation subcutaneously results in release of the implant by raising the protrusion.

18. The assembly of claim 13, further comprising a cannula holder, a rod mounted on the housing and extending at least partially into the cannula or the cannula holder, and an actuator for sliding the cannula and the rod relative to each other.

19. The assembly of claim 18, wherein the cannula hub is disposed at a proximal end of the cannula and is slidable on the rod, and wherein the actuator and the cannula hub are interconnected by a flexible member.

20. The assembly of claim 13, wherein the implant is an elongated rod-like member comprising an active substance.

21. The assembly of claim 20, wherein the active substance is a progesterone hormone.

22. Applicator for inserting a rod-shaped contraceptive implant containing a proestrogen under the skin of a human or animal, comprising:

a housing;

a sleeve having a length extending from the housing;

a rod-shaped implant of 40mm length and 2mm diameter held within the cannula prior to use;

a handle for grasping and manipulating the applicator and cannula during insertion of the implant, wherein the handle extends along and is spaced apart from the entire length of the cannula.