INJECTION END POINT SIGNALLING ASSEMBLY FOR PRE-FILLED SYRINGES

Abstract

An injection endpoint signalling assembly is provided that is adapted and configured for mounting on, and use with, a pre-filled syringe. The injection endpoint assembly is configured to prevent a signalling of an injection endpoint before the plunger of the pre-filled syringe has reached a limit of a permitted extent of a direction of injection travel. The assembly is further configured to enable the signalling of the injection end point when the plunger of the pre-filled syringe has reached the limit of the permitted extent of the direction of injection travel and is prevented from moving in a direction of travel different to the direction of injection travel.

Claims

1. An injection end point signalling assembly adapted and configured for mounting on, and use with, a pre-filled syringe, the pre-filled syringe comprising: an elongated hollow syringe body having a proximal extremity and a distal extremity, with a first opening at the proximal extremity and a collar projecting outwardly of the hollow syringe body at said proximal extremity around said first opening; an injection needle mounted, or mountable, at the distal extremity of the hollow elongated syringe body and closing a second opening of the hollow elongated syringe body at said distal extremity; an amount of injectable material introduced into the hollow body; a plunger configured and dimensioned to be inserted into said hollow elongated syringe body via the proximal extremity and corresponding proximal opening of the hollow syringe body, the plunger having a plunger body comprising a stopper located at a distal extremity of the plunger body, and a plunger head located at a proximal extremity of said plunger body; wherein the injection end point assembly is configured to prevent a signalling of an injection end point before the plunger has reached a limit of a permitted extent of a direction of injection travel; and wherein the injection end point assembly is further configured to enable the signalling of the injection end point when the plunger has reached the limit of the permitted extent of the direction of injection travel and is prevented from moving in a direction of travel different to said direction of injection travel.

2. The injection end point signalling assembly according to claim 1, wherein the end point signalling assembly comprises a displaceable electrical contact configured to enable signalling of the injection point.

3. The injection end point signalling assembly according to claim 1, wherein the end point signalling assembly comprises plunger travel locking means configured to prevent the plunger from moving in a direction of travel different to the direction of injection travel once the limit of the permitted extent of the direction of injection travel has been reached.

4. The injection end point signalling assembly according to claim 1, including a displaceable electrical contact and plunger travel locking means, wherein the displaceable electrical contact forms an electrical contact at the same time as the plunger travel locking means are engaged.

5. The injection end point signalling assembly according to claim 1, including plunger travel locking means wherein the plunger travel locking means comprise at least one radially outwardly projecting tine, or a plurality of radially outwardly projecting tines, connected to the plunger body; and wherein the one or plurality of radially outwardly projecting tines is connected to the plunger body via an elastically deformable arm.

6. (canceled)

7. The injection end point signalling assembly according to claim 1, including plunger travel locking means wherein the plunger travel locking means comprise at least one pair of cooperating and opposite abutment surfaces; and wherein the at least one part of cooperating and opposite facing abutment surfaces each comprise a ridged portion of material.

8. (canceled)

9. The injection end point signalling assembly according to claim 1, wherein a displaceable electrical contact establishes an electrical contact via a translational movement of an electrical contact applicator, in a direction different to the direction of injection travel, from a first non-contact position in which no electrical contact is established, to a second contact position establishing an electrical contact.

10. The injection end point signalling assembly according to claim 1, including a contact applicator, wherein the contact applicator is displaced via a translational movement substantially in parallel to a longitudinal axis of the plunger.

11. The injection end point signalling assembly according to claim 1, including a contact applicator, wherein the contact applicator comprises an electrically conducting surface.

12. The injection end point signalling assembly according to claim 1, including a contact applicator wherein the contact applicator is located within the plunger head.

13. The injection end point assembly according to claim 1, further comprising displacement means and a contact applicator wherein the displacement means is configured to engage with the contact applicator as the plunger is moved in the direction on injection travel, and cause displacement of the contact applicator in a direction different to said direction of injection travel.

14. The injection end point signalling assembly according to claim 1, including displacement means, wherein the displacement means are at least partly located on, or integrated into, the collar of the hollow syringe body.

15. The injection end point signalling assembly according to claim 1, including displacement means wherein the displacement means are located on a syringe backstop removably mounted onto the collar of the hollow syringe body.

16. The injection end point signalling assembly according to claim 1, including displacement means wherein the displacement means comprise a raised arcuate profile located coaxially around a longitudinal axis of the plunger, on either a proximal surface or the collar, or a proximal surface of a syringe backstop.

17. (canceled)

18. The injection end point signalling assembly according to claim 1, further comprising anti-tamper means configured to prevent tampering of the plunger head when an electrical contact has been established and when the plunger has reached the limit of the permitted extent of the direction of injection travel; and wherein the anti-tamper means comprise a wall located radially outwardly of a displacement means around the longitudinal axis of the plunger, and projecting in a proximal direction; and wherein the projecting wall has a proximal extremity that is located adjacent or substantially flush with a proximal surface of the plunger head.

19. (canceled)

20. (canceled)

21. The injection end signalling assembly according to claim 1, wherein a first cooperating abutment surface is located on an inner surface of a projecting wall of a syringe backstop, and a second cooperating abutment surface is located on an outer surface of the plunger head.

22. The injection end point signalling assembly according to claim 1, wherein the injection end point assembly further comprises a wireless communications unit.

23. The injection end point signalling assembly according to claim 22, wherein the wireless communications unit is near field communications (NFC) circuit.

24. The injection end point signalling assembly according to claim 23, wherein the near field communications circuit is located in the plunger head.

25. The injection end point signalling assembly according to claim 23, wherein the near field communications circuit can only be energized when an electrical contact has been established.

26. (canceled)

Description

BRIEF DESCRIPTION OF THE FIGURES

[0046] The invention will now further be described in relation to the figures, provided for illustrative purposes of various embodiments of the invention:

[0047] FIG. 1 represents a schematic perspective view of a pre-filled syringe with an injection end point signalling assembly according to the invention;

[0048] FIG. 2 represents a schematic partially cut-away view of a proximal end of a pre-filled syringe and injection end point signalling assembly according to FIG. 1;

[0049] FIG. 3 represents a schematic cross-sectional view of the end point signalling assembly according to FIG. 1 mounted on a pre-filled syringe in an initial, ready-to-use position;

[0050] FIG. 4 represents a schematic cross-sectional view of the injection endpoint signalling assembly according to the invention at the beginning of the injection;

[0051] FIG. 5 represents a schematic, close-up cross-sectional view of a proximal extremity of the endpoint signalling assembly of FIG. 4;

[0052] FIG. 6 represents a schematic, cross-sectional view of the injection endpoint signalling assembly according to the invention at the end of the injection;

[0053] FIG. 7 represents a schematic, close-up cross-sectional view of a proximal extremity of the endpoint signalling assembly of FIG. 6;

[0054] FIGS. 8 and 9 represent schematic cross-sectional views of an alternative locking means for the injection endpoint signalling assembly according to the invention in a position at the beginning of an injection and at the end of an injection respectively;

[0055] FIGS. 10 and 11 represent the alternative locking means of the injection endpoint signalling assembly of FIGS. 8 and 9, at the beginning of an injection and the end of an injection respectively.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0056] Turning now to the figures, a pre-filled syringe (1) is illustrated in FIGS. 1 and 3. The pre-filled syringe (1) has an elongated hollow syringe body (2) having a proximal extremity (3) and a distal extremity (4), with a first opening (5) at the proximal extremity (3) and a collar (6), or flange, projecting outwardly of the hollow syringe body (2) at said proximal extremity (3) around said first opening (5). An injection needle (not shown) covered by a needle cap (not shown) is usually mounted at the distal extremity (4) of the hollow elongated syringe body (2) and closes a second, distal opening (7) of the hollow elongated syringe body (2) at said distal extremity (4). A controlled amount of injectable material (not shown) such as a drug in liquid or form, is introduced into the hollow body (2) during assembly of the syringe components.

[0057] A plunger (8) is configured and dimensioned to be inserted into the hollow elongated syringe body (2) via the proximal extremity (3) and corresponding proximal opening (5) of the hollow syringe body (2), the plunger (8) having a plunger body or rod (9) comprising a stopper (10) located at a distal extremity (11) of the plunger body (9). The stopper (10) can be connected in a known way to the plunger body (9), for example, through the provision of a screw threaded projection (12) at the distal extremity (11) of the plunger body (9), and a corresponding screw-threaded bore (13) provided inside the stopper (10) at a proximal extremity thereof (14). The plunger body (9) further has a plunger head (15) located at a proximal extremity (16) of said plunger body (9). The plunger (8) and syringe body (2) are in substantial longitudinal alignment along a central longitudinal axis (17) of the syringe body (2).

[0058] The plunger head (15) has a substantially circular plate (18) extending radially outwards from the proximal extremity (16) of the plunger body (9). A peripheral annular wall (19) is located on the plate (18) and extends from the plate (18) in a proximal direction forming a well (20). The well is closed at its proximal extremity by a communications unit (21) comprising an NFC circuit, illustrated in the figures as a disc located upon the proximal extremity of the peripheral annular wall (19) of the well (20).

[0059] A plunger cap or cover (22) closes the well (20) and covers both the well (20) and the communications circuit (21), the plunger cap (22) being provided with fitting means (23A, 23B) to prevent the cap (22) from falling off or detaching from the well (20), for example a push-fit or snap-fit coupling consisting of an annular groove (23A) provided on an inside surface of a distally projecting annular wall (24) of the cap (22) and a corresponding and mating annular ridge (23B) provided on an outside surface of the peripheral annular wall (19) projecting from the plate (18) of the well (20).

[0060] The injection end point assembly further comprises a backstop (25), which is located on the flange or collar (6) of the syringe body (2). Most commercially available backstops (25) comprise a disk-shaped body with a central opening, adapted for receiving the syringe body and configured to enable clip-fit or push-fit of the backstop body onto the collar (6). To this end, the backstops generally comprise a corresponding seating groove (26), and moulded shoulders, or other projections to enable the backstop (25) to be appropriately fitted to a variety of different shaped collars (6), depending on the type of syringe to which the backstop is mounted. In the present example, the backstop (25) further comprises a substantially annular shaped peripheral wall (27) extending in a proximal direction from the backstop body and terminating in a proximal extremity (28), intended to serve as an anti-tamper means, and which will be described in more detail herein.

[0061] Also visible in FIGS. 1, 2, and 3 is a proximal surface (29) of the backstop (25) on which has been affixed or integrated therewith, for example, via deposition or moulding, are displacement means (30) exemplified here as a raised profile (30) which projects in a distal direction. The raised profile (30) is substantially arcuate in shape around the central opening of the backstop body, and is thus also located radially around the longitudinal axis (17). The raised profile of the displacement means (30) in the illustrated example is substantially contiguous and can be provided with spurs (31A, 31B, 31C) which project outwardly from the raised profile, lending an overall serpentine shape to the displacement means.

[0062] The displacement means (30) provide a main function of displacement for an electrical contact applicator (32) which is located within the well (20) formed by the plate (18) and peripheral annular wall (19). The electrical contact applicator (32) is a movable, preferably translatable, member, such as a disk or plate (33), in coaxial alignment with the longitudinal axis (17). The disk (33) is mounted on a central rod (34) that is in alignment with the longitudinal axis (17), which rod (34) is slidingly located in a bore (35) that extends from the bottom of the plate (18) in a proximal direction into the body (9) of the plunger (8). The dimensions of the rod (34) and bore (35) are so configured that the rod can not slide of its own free motion within the bore, rather the rod (34) must be constrained into movement by application of force to be able to move slidingly within the bore (35). The central rod (34) also extends in a proximal direction above a proximal surface of the disk (33) to provide at least one proximal electrical contact surface (36), which can comprise an electrically conducting layer, such as a layer of deposited carbon, or an electrically conducting metal, either in elemental form or as a matrix of electrically conducting materials, deposited on, or integrated into the proximal surface. If desired or appropriate, an at least one alternative or further electrical contact surface can optionally be provided at one or more peripheral locations situated radially of the central electrical contact surface (36) on corresponding projections extending proximally from the disk (33).

[0063] In a first position, when the pre-filled syringe is either in a ready to use state, as in FIG. 3, or at the beginning of an injection, as illustrated in FIGS. 4 and 5, the electrical contact applicator (32) is in a first electrically contact-less position, seated at the bottom of the well, with the rod (34) extending substantially into the bore (35) such that a distal extremity of the rod almost touches a proximal facing surface of the distal extremity of the bore (35). Seating of the applicator (32) can further be provided by a projection (37) which extends distally from the disk (33) in a radially spaced apart relationship to the rod (34) through an opening (38) provided in the plate (18). In this position, the distal facing projection (37) extending from disk (33) is situated in alignment with the raised profile of the displacement means (30), but physically spaced apart from the displacement means.

[0064] The communications unit (21), generally comprising a disk-shaped circuit board, a passive NFC circuit including an ID tag included in the circuit board, an antenna, for example, distributed in a spiral configuration around the NFC circuit and located around a peripheral edge of the circuit board, also has an electrical gap or isolation area, provided on a distal face of the circuit board, for example in a central position of the circuit board and in axial alignment with both the longitudinal axis (17) and the electrical contact surface (36), or alternatively and/or additionally, at a peripheral edge of the circuit board to be aligned with the alternative and/or additional electrical contact surfaces provided on further peripheral and/or radially located proximally facing projections extending from the disk (33). In this initial ready-to-use position, as illustrated by FIG. 3, or at the beginning of an injection, as illustrated in FIGS. 4 and 5, the circuit remains in an open state, preventing any flow of electrical charge or current within the circuit, even in the presence of an applied RF energization, such as the approach of a suitably equipped smartphone having and NFC circuit.

[0065] FIGS. 3, 4 and 5 further illustrate the presence of plunger travel locking means (39) provided on the plunger (9). The plunger travel locking means (39) comprise at least one radially outwardly projecting tine (40), or a plurality of radially outwardly projecting tines, connected to the plunger body (9). The projecting tines can either be directly formed on the plunger body, for example, at a substantially proximal region of the plunger body, or alternatively, and equally advantageously, they can be connected indirectly to the plunger body via intermediate connecting means, such as an arm (41) as illustrated in the figures. The arm (41) is elastically deformable. In such an embodiment, the elastically deformable arms are advantageously made of the same or a similar material to the plunger body itself, and can extend from a distally located region, such as a shoulder (42) provided on the plunger body (9), in a proximal direction towards the proximal extremity of the plunger body. The arms are elastically deformable, or resilient, in a generally radial direction, meaning that they can either move towards the plunger body, or move away from the plunger body in such a radial direction, depending on the radial forces applied to the arms. As illustrated in FIGS. 4 and 5, upon beginning of the injection, the plunger body (9) is pushed into the bore of the syringe body and the relatively more rigid walls of the syringe body cause the arms (41) to be compressed radially inwardly towards the plunger body (9). In addition, the tines (40) come into contact with a proximally facing inwardly sloping surface (43) provided on the disk body of the backstop (25), which proximally facing inwardly sloping surface projects over the collar (6) and at least partially into the bore of the syringe body, forming a locking shoulder (44). This is situation is particularly illustrated by FIG. 5.

[0066] FIGS. 6 and 7 illustrate the relative positions of the components of the injection endpoint signally assembly at the end of injection. As further injection pressure is applied, the plunger body (6) moves in a distal direction, and the resistance of the inwardly sloping shoulders (43), coupled with the resilience or elastic deformation of the arms (41), causes the tines (40) to be moved via deformation of the arms in a radially inwards direction, thereby forcing the tines over the inwardly sloping surface (43) of the locking shoulder (44) into the bore of the syringe body. The tines (40) therefore come to bear in friction contact on the inside wall of the syringe body.

[0067] The friction contact between the tines (40) and the inside wall of the syringe body is generally sufficient to prevent withdrawal of the plunger body (9) if a retracting force on the plunger body (9) is exerted in a direction opposite to the injection direction. However, in order to ensure that this can not occur, the locking shoulder (44) formed by the inwardly sloping surface (43) which projects at least partly into the bore of the syringe body actively prevents the plunger from being withdrawn, as the tines (40) abut against the projecting area of the locking shoulder (44) and the natural tendency of the elastically deformable arms (41) to move the tines (40) radially outwardly only serves to increase the locking effect. At the end of injection therefore, the assembly is essentially prevented, or locked from moving in a direction different to that of the direction of injection travel.

[0068] At the same time as the plunger body is moved distally during injection, plate (18) of the plunger body (9) is moved towards the raised profile of the displacement means (30). Further progression of the injection causes the projection (37) extending distally through opening (38) to come into abutting contact with the raised profile of the displacement means (30). Continued distal movement of the plunger exerts a sufficient force to overcome any resistance to effort provided for in the dimensioning of the rod (34) and bore (35), such that the projection (37) which is fixedly connected to the disk (33) of the electrical contact applicator (32), causes the contact applicator to be moved, or translated, from the first contactless position, in a direction opposite to that of the direction of injection travel, towards the second position in which an electrical connection will be established in the communications circuit. When the plunger has reached its maximum extent of permitted injection travel, the disk (33) will have been moved in an opposite direction by the interplay of the distal projection (37) and raised profile of the displacement means (30) which is sufficient to bring the electrically conducting contact surface (36) into contact with the electrical isolation area or electrical gap in the circuit, and thereby close that circuit.

[0069] In this second position therefore, electrical contact is both established in the circuit, and the endpoint signalling assembly is locked in position preventing any accidental or wilful displacement of both the plunger (8) and the electrical contact applicator (32). Closure of the circuit allows the passive NFC circuit to function when energized by an appropriate external radio frequency such as when a NFC-equipped device, for example, a smartphone or tablet or other NFC reader, is brought in sufficiently close proximity to the plunger head (15), or vice-versa, when the plunger head (15) of the now empty syringe is brought in close proximity to such a NFC-equipped device. Energization of the passive NFC circuit in this way then enables signalling to occur, allowing the data stored in the ID tag of the NFC circuit to be read, and the injection end point to be thus suitably signalled to the NFC-equipped device.

[0070] As is also apparent from the various figures, the distally projecting annular wall (24) of plunger head cap (21) extends in a distal direction beyond the level or position of the plunger head plate (18). This surplus distance is used to advantage in an alternative embodiment of the locking means provided in the injection endpoint signalling assembly and illustrated in particular in FIGS. 8,9, 10 and 11. Like numeric references are provided to designate like objects from FIGS. 1 to 7.

[0071] FIGS. 8 and 10 represent the injection endpoint signalling assembly at the beginning of an injection. FIGS. 9 and 11 represent the injection endpoint signalling assembly at the end of an injection, when the maximum permitted distance of injection travel has been reached. Turning now to FIGS. 8 and 10, the most immediately noticeable difference between the embodiments described with regards to FIGS. 1 to 7 is the absence of radially projecting tines and elastically deformable arms provided on the plunger body. In the embodiment represented by FIGS. 8 to 11, the plunger travel locking means are provided by at least one pair of opposite-facing abutment surfaces located elsewhere, and in particular a first abutment surface (45) provided on an inner surface (46) of the proximally projecting backstop wall (27). This first abutment surface is usefully provided via a ridged or raised portion of material that is preferably the same as the material from the which the backstop proximally projecting wall is made, but alternatively could be a ridge portion of appropriately elastically deformable or resilient material that is added onto said inner surface, for example, by welding, gluing, remoulding and the like. In FIGS. 8 and 10, the ridged portion is located at or adjacent to the distal extremity (47) of the distally projecting peripheral annular wall (24) of the cap (22). A second and opposite facing abutment surface (48) is provided on an outer surface of the cap (22) and is usefully provided via a ridged or raised portion of material that is preferably the same as the material from the which the cap peripheral and distally projecting wall is made, but alternatively could be a ridge portion of appropriately elastically deformable or resilient material that is added onto said outer surface, for example, by welding, gluing, remoulding and the like. In FIGS. 8 and 10 the second abutment surface (48) is located above the first abutment surface (45), but has a distal facing surface of the ridged portion in abutting contact with a proximal facing surface of the ridged portion of the first surface, this configuration preventing the cap from moving in a distal direction without application of an appropriate force to move it in that direction.

[0072] Upon injection, a force is applied to the cap (22) in a proximal direction. This force, when sufficiently applied, for example, as a user presses on the cap, enables the distal abutting surface of the ridged portion of the second abutment surface (48) to overcome the resistance opposed by the first abutment surface (45) and move past the ridged portion of the first abutment surface to allow the injection to proceed. Once injection has finished, the plunger and corresponding plunger head, have attained the maximum permitted limit or distance of injection travel. As illustrated by FIGS. 9 and 11, in this position the second abutment surface (48) is now located proximally of the first abutment surface. Additionally, a proximal surface of the ridged portion of the second abutment surface (48) is now in abutting contact with a distal surface of the ridged portion of the first abutment surface (45). The abutting surfaces prevent the plunger and cap from being moved in a direction opposite to the direction of injection travel, thereby locking the endpoint signalling assembly. The electrical contact applicator is moved in the same way as described for FIGS. 1 to 7, meaning that at the end of injection, the electrical contact has closed the gap or electric isolation in the communications circuit, allowing signalling to occur through energization of the circuit by the approach of suitably equipped energizing device, such as a smartphone. Additionally, the cap (22), which has a proximal surface (49) adjacent to, or flush with, the proximal extremity (28) of the backstop proximally projecting wall (29), can be provided with rounded corners (50), which together serve as anti-tamper means to prevent attempts to grab the plunger cap to attempt to impose a proximally directed traction force thereon.