Miniaturized injection device for medical use

1. A miniaturized injection device ( 1 ; 51 ) for medical use comprising two tubes ( 2 ; 52 ; 3 , 53 ) extending along a certain axial direction (A-A; B-B), a first tube ( 2 ; 52 ) inserted in a second tube ( 3 ; 53 ) with which it cooperates to form a cavity, in which second tube ( 3 ; 53 ) there is placed at least one reservoir ( 12 ; 512 ) for receiving a medicinal substance, the reservoir ( 12 ; 512 ) being connected to at least one needle ( 14 ; 514 ) disposed on a support ( 23 ) axially movable within said first tube ( 2 ; 52 ) in such a manner that said needle ( 14 ; 514 ) is moved axially in said first tube ( 2 ; 52 ) in response to axial movement of said second tube ( 3 ; 53 ) relative to said first tube ( 2 ; 52 ), and the miniaturized injection device ( 1 ; 51 ) being characterized in that, it is arranged in order that, in a step, the pressure exerted on said second tube ( 3 ; 53 ) and the axial translation movement of said second tube ( 3 ; 53 ) is transmitted to said reservoir ( 12 ; 512 ), said needle ( 14 ; 514 ) and said support ( 23 ), said needle ( 14 ; 514 ) being therefore movable in said first tube ( 2 ; 52 ) along said axial direction (A-A; B-B), and in that it further comprises a pump ( 13 ; 513 ) interposed between said needle ( 14 ; 514 ) and said reservoir ( 12 ; 512 ), said pump ( 13 ; 513 ) being controlled by means of a switch ( 21 ; 521 ) that operates, in a further step, in response to said axial translation movement of said needle ( 14 ; 514 ) and said reservoir ( 12 ; 512 ) and said support ( 23 ) in said first tube ( 2 ; 52 ) along said axial direction (A-A; B-B), leading to contact between an abutment ( 22 ) and said switch ( 21 ; 521 ), said switch ( 21 ; 521 ) being able to change state, thereby having the effect of causing said pump ( 13 ; 513 ) to operate and leading in again a further step to the medicinal substance being injected into the patient's body.

2. An injection device according to claim 1 , in which the needle ( 14 ; 514 ) initially moves forwards along said axial direction (A-A; B-B) so as to move out from the tube ( 2 ; 52 ), and then rearwards back along said axial direction (A-A; B-B) in order to retract into the tube ( 2 ; 52 ), the injection device including blocking means ( 28 ) for blocking movement of the needle ( 14 ; 514 ) and that act to block movement of the needle ( 14 ; 514 ) after it has moved twice in the tube ( 2 ; 52 ) respectively forwards and rearwards.

3. An injection device according to claim 2 , in which the blocking means comprises an L-shaped lever ( 30 ) pivotally mounted at the intersection between limbs of the L-shape.

4. An injection device according to claim 1 , in which said pump ( 13 ; 513 ) is an electric pump powered by an electric motor connected to a battery ( 24 ; 537 ) via said switch ( 21 ; 521 ).

5. An injection device according to claim 1 , in which the needle ( 14 ; 514 ) is movable axially as far as an abutment ( 22 ; 522 ), and in which the switch ( 21 ; 521 ) is operated when the needle ( 14 ; 514 ) comes into abutment.

6. An injection device according to claim 1 , in which the pump ( 13 ; 513 ) is mounted in a needle support ( 23 ; 536 ) that is movable axially within the tube, at least one spring ( 18 , 518 ) being provided in the tube to oppose movement of the support ( 23 ; 536 ) in the tube ( 2 ; 52 ).

7. An injection device according to claim 1 , in which said reservoir ( 12 ; 512 ) is movable axially relative to the needle ( 14 ; 514 ) in the tube, and in which the reservoir ( 12 ; 512 ) is connected to the pump ( 13 ; 513 ) via at least one percussion cone ( 16 ; 516 ).

8. An injection device according to claim 1 , in which said tube ( 2 ; 52 ) is an inner tube inserted in an outer tube ( 3 ; 53 ) disposed coaxially about said inner tube, in such a manner that the needle ( 14 ; 514 ) is moved axially in the inner tube in response to axial movement of the outer tube relative to the inner tube.

9. An injection device according to claim 8 , in which said inner and outer tubes present respective first and second collars ( 5 , 7 ; 55 , 57 ) about the axis, and in which a removable spacer ( 4 ; 54 ) is interposed between the two collars ( 5 , 7 ; 55 , 57 ) to block relative axial movement of one tube relative to the other.

10. An injection device according to claim 1 , in which the reservoir ( 12 ) with the pump ( 13 ) and the needle ( 14 ) are assembled together to form a cartridge.

11. An injection device according to claim 1 , characterized in that it includes a plurality of cartridges ( 526 ).

12. An injection device according to claim 11 , in which said cartridges ( 526 ) present respective sections in the form of circular sectors and are distributed around the longitudinal axis (B-B).

13. An injection device according to claim 11 , characterized in that said cartridges ( 526 ) are disposed in a support system ( 525 ) that is rotatable about the longitudinal axis (B-B).

14. An injection device according to claim 1 , in which each needle ( 14 ; 514 ) has one or more vents ( 102 ) that are disposed laterally relative to the needle.

15. An injection device according to claim 14 , in which said vents ( 102 ) are disposed in a circular or a spiral configuration.

16. An injection device according to claim 1 , in which said reservoir ( 12 ; 512 ) is rigid.