Dose control device for injectable-drug delivery devices

1. Dose control device for a handheld pen-type injectable-drug delivery device, the handheld pen-type injectable-drug delivery device comprising an elongate body with a proximal and distal extremity, a longitudinal axis extending from the proximal extremity of the elongate body to the distal extremity of the elongate body, and a rotatable dose setting wheel located at said proximal extremity, wherein said dose control device comprises:

a magnetic field producing means located at the proximal extremity of said elongate body;

one or more magnetic field sensors in communication with a data processing unit located at the elongate body; and

a clutch assembly configured to selectively move the magnetic field producing means from a first, engaged, position, to a second, disengaged, position;

wherein said clutch assembly comprises:

a cylindrical body having a longitudinal inner bore and a proximal extremity, wherein the magnetic field producing means is located within said bore of said cylindrical body, said cylindrical body being removably mounted in axial longitudinal alignment around said rotatable dose setting wheel with an annular wall extending within and along said bore towards the proximal extremity of the cylindrical body, wherein the cylindrical body is configured to be co-rotatable with the dose setting wheel.

2. Dose control device according to claim 1 , wherein the first, engaged, position is a position in which the magnetic field producing means is held within the bore of the cylindrical body such that any rotational movement of said cylindrical body communicates directly to said magnetic field producing means causing said magnetic field producing means to rotate.

3. Dose control device according to claim 1 , wherein the second, disengaged, position is a position in which the magnetic field producing means is held within the bore of the cylindrical body such that any rotational movement of said cylindrical body is not communicated to said magnetic field producing means.

4. Dose control device according to claim 1 , wherein said cylindrical body has a distal extremity, said distal extremity being configured to mate with and grip an outer surface of said dose setting wheel, and the proximal extremity of the cylindrical body configured to receive at least a part of a clutch activation button.

5. Dose control device according to claim 1 , wherein said annular wall is connected to an inner surface wall of said cylindrical body.

6. Dose control device according to claim 1 , wherein said annular wall is connected to a cylindrical body inner surface wall via a first annular skirt which extends radially outwards from said annular wall to said cylindrical body inner surface wall.

7. Dose control device according to claim 6 , wherein said annular wall, said first annular skirt and said cylindrical body inner surface wall form an annular groove for receiving at least a part of a clutch activation button.

8. Dose control device according to claim 6 , wherein said annular wall further comprises a second annular skirt, located at a proximal extremity of said annular wall, which projects radially inwardly from said annular wall proximal extremity into the bore of said cylindrical body.

9. Dose control device according to claim 1 , wherein said clutch assembly further comprises a magnetic field producing means holder, wherein said magnetic field producing means holder comprises a holder body having a longitudinal bore, a proximal extremity and a distal extremity, and said magnetic field producing means holder includes a body of a magnetic field producing means material.

10. Dose control device according to claim 9 , wherein said magnetic field producing means holder body comprises a skirt, located adjacent the distal extremity of the holder body, said skirt comprising a substantially planar surface extending radially outwards from said holder body and an annular peripheral wall extending distally from a peripheral edge of said substantially planar surface.

11. Dose control device according to claim 10 , wherein said skirt further comprises at least one seating means for the magnetic field producing means, located within an inner volume defined by the skirt, said at least one seating means being configured to receive and seat said magnetic field producing means within said skirt.

12. Dose control device according to claim 9 , wherein said holder body further comprises an activation button engagement member, configured to engage and retain a clutch activation button.

13. Dose control device according to claim 12 , wherein said clutch Activation button engagement member is located within the longitudinal bore of the holder body, adjacent the proximal extremity thereof.

14. Dose control device according to claim 1 , wherein said clutch assembly further comprises a clutch activation button.

15. Dose control device according to claim 14 , wherein said clutch activation button comprises a holder engagement member, configured to retain and engage with an activation button engagement member provided on a magnetic field producing means holder.

16. Dose control device according to claim 15 , wherein said clutch assembly further comprises a pre-constrained biasing member, located between an annular skirt projecting radially inwardly from an annular wall adjacent the proximal extremity of said cylindrical body, and the clutch activation button, and said pre-constrained biasing member is seated distally on the annular skirt of the annular wall of said cylindrical body, and inserted into an inner, substantially cylindrical volume of said clutch activation button, to seat proximally against a closed proximal extremity of said inner volume.

17. Dose control device according to claim 16 , wherein said pre-constrained biasing member, in the first engaged clutch assembly position, adopts a relatively unconstrained conformation, and in the second disengaged clutch assembly position, a relatively constrained conformation.

18. Dose control device according to claim 16 , wherein said pre-constrained biasing member is a flat wire compression spring or a wave spring.

19. Dose control device according to claim 14 , wherein the cylindrical body further comprises a frictional layer comprising a thermoplastic elastomer gel located on an inner wall of the proximal extremity of the cylindrical body, and wherein a magnetic field producing means holder body is selectively engageable with, and disengageable from, the frictional layer provided within the cylindrical body.