Needle location device

1. A medical needle location device comprising:

a housing arranged to be gripped by a user and

a needle supported by the housing, the needle depending from the housing towards a needle tip,

wherein the housing comprises an excitation mechanism for applying an oscillatory motion to the needle during location within a human or animal body, and the device comprises a drive mechanism for driving the excitation mechanism,

the drive mechanism comprising a user interface portion adapted to receive mechanical energy input from the user, the excitation mechanism being mechanically coupled to the drive mechanism such that the drive mechanism and the excitation mechanism are manually driven, the excitation mechanism is configured to apply the oscillatory motion to the needle at a frequency greater than a frequency of operation of the drive mechanism by the user interface portion,

wherein the device further comprises a needle deployment mechanism for gross longitudinal or rotational movement of the needle.

2. A device according to claim 1 , wherein the excitation mechanism comprises an excitation member arranged to impart cyclical excitation forces to the needle.

3. A device according to claim 2 , wherein the excitation member is rotatable.

4. A device according to claim 3 , wherein the rotatable excitation member comprises an eccentric member.

5. A device according to claim 3 , wherein the rotatable excitation member comprises one or more projections or teeth thereon arranged to interfere with a receiving member.

6. A device according to claim 2 comprising an intermediate member in a force path between the excitation member and the needle.

7. A device according to claim 1 , wherein the drive mechanism is adapted to receive energy from an energy store, which is charged by the moveable user interface portion being coupled directly, or via intermediate members, to the energy store.

8. A device according to claim 1 , wherein the user interface portion is moveable relative to the housing of the device.

9. A device according to claim 8 , wherein the user interface portion is moveable towards a portion of the housing of the device during actuation.

10. A device according to claim 1 , wherein the drive mechanism imparts motion to an excitation member of the excitation mechanism arranged to impart cyclical excitation forces to the needle.

11. A device according to claim 10 , wherein the drive mechanism comprises a release mechanism for disengaging the drive mechanism from the excitation member.

12. A device according to claim 11 , wherein the release mechanism comprises a resilient member.

13. A device according to claim 10 , wherein the drive mechanism comprises a drive member actuable between a first configuration in which the drive member is engaged with the excitation member, and a second configuration in which the drive member is disengaged from the excitation member.

14. A device according to claim 13 , wherein the excitation member is configured to maintain the motion imparted on the excitation member by the drive mechanism when the drive mechanism is in the second configuration.

15. A device according to claim 1 , wherein the excitation mechanism is arranged to cause excitation of the needle for a duration of one second or more.

16. A device according to claim 15 , wherein the mechanism excites the needle for a predetermined duration of a plurality of seconds.

17. A device according to claim 1 , wherein the excitation mechanism imparts vibrations to the needle.

18. A device according to claim 1 , wherein the device is a biopsy needle device for taking tissue samples from a body.

19. A device according to claim 1 , wherein the excitation and deployment mechanisms are individually operable or triggered.

20. A device according to claim 1 , wherein the needle is surrounded by a sleeve.

21. A device according to claim 1 , wherein the excitation mechanism applies the oscillatory motion to the needle at a frequency greater than 5 Hz.