Medical device

• US 20020035348A1
• Filed: 05/22/2001
• Published: 03/21/2002
• Est. Priority Date: 05/22/2000
• Status: Active Grant

• Current Assignee: Pharmacia AB (Pharmacia Corp.)
• Original Assignee: Pharmacia AB (Pharmacia Corp.)
• Inventors: Hjertman, Birger
• Granted Patent: US 6,740,062 B2
• Time in Patent Office: Days
• US Class Current: 604/70
• CPC Class Codes: A61M 2005/2462 by displacing occluding plugs
• CPC Class Codes: A61M 5/2448 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/2459 upon internal pressure increase, e.g. pierced or burst A61M5/2429 takes precedence
• CPC Class Codes: A61M 5/284 comprising means for injection of two or more media, e.g. by mixing
• CPC Class Codes: A61M 5/286 upon internal pressure increase, e.g. pierced or burst A61M5/283 takes precedence
• CPC Class Codes: A61M 5/30 Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules

Abstract

The invention relates to an injector device for delivery of liquid from a high pressure source, and also to a method of performing such an injection. The device comprises a storage chamber 6, for the liquid or the liquid precursor components, comprising a storage barrel 16 with at least a section of substantially constant cross-section, defining a storage chamber axis, and a pressure chamber 4 comprising a pressure barrel 10 of substantially constant cross-section, defining a pressure chamber axis, for accommodation of at least one piston therein and having a front end opening 14 for ejection of the liquid. The pressure chamber being of sufficient strength to sustain the liquid pressure. The chambers are separate parts and adapted to cooperate with each other during injection so that the pressure chamber axis and the storage chamber axis substantially coincide, and that the pressure barrel and storage barrel have internal diameters sufficiently similar to allow passage of a resilient piston from the storage barrel to the pressure barrel in a sealing manner. The liquid is transferred from the storage chamber directly into the delivery chamber when the jet injection is to be performed.

Claims

1. An injector device for delivery of liquid from a high pressure source, the device comprising

a) a pressure chamber (4) comprising a pressure barrel (10) of substantially constant cross-section, defining a pressure chamber axis (12), for accommodation of at least one piston therein and having a front end opening (14) for ejection of the liquid, the pressure chamber being of sufficient strength to sustain the liquid pressure;

b) a storage chamber (6), for the liquid or the liquid precursor components, comprising a storage barrel (16) with at least a section of substantially constant cross-section, defining a storage chamber axis (18), for accommodation of at least one piston (20,22) therein, optionally with a by-pass section therein;

c) a liquid connection (24) between the pressure chamber and the storage chamber allowing transfer of the liquid from the storage chamber to the pressure chamber;

e) at least a first piston arranged for travel in the pressure barrel and

d) a mechanism (8) arranged to apply force, directly or indirectly, on the piston when in the pressure barrel to create said liquid pressure, characterized in the improvement comprising,

i) that the pressure chamber axis and the storage chamber axis substantially coincide;

ii) that the pressure barrel and storage barrel have internal diameters sufficiently similar to allow passage of a resilient piston from the storage barrel to the pressure barrel in a sealing manner, except when in the optional by-pass or the connection, and

iii) that the storage chamber is separate from the pressure chamber.

2. Injector device according to claim 1, characterized in that the front end opening (14) is designed for formation of a liquid jet, with a short needle having a length of about 1 to 3 mm or a hypodermic needle.

3. Injector device according to any of the preceding claims, characterized in that the front end opening is covered with a removable or breakable closure or sealing.

4. Injector device according to any of the preceding claims , characterized in that said pressure barrel is provided with an open rear end and that said storage barrel is provided with an open front end.

5. Injector device according to any of the preceding claims, characterized in that the liquid connection comprises a by-pass (24), arranged to allow liquid passage from the storage chamber to the pressure chamber around the front piston (22).

6. Injector device according to any of the preceding claims, characterized in that the pressure chamber and storage chamber are made from different materials, preferably plastic and glass respectively.

7. Injector device according to any of the preceding claims, characterized in that a sealer is provided between the pressure chamber and the storage chamber.

8. Injector device according to any of the preceding claims, characterized in at least a second piston arranged for movement in the storage chamber and able to confine the storage chamber in cooperation with the first piston.

9. Injector device according to any of the preceding claims, characterized in that said storage chamber is a dual chamber storage chamber provided with by-pass section and at least a third piston dividing the storage chamber into two subchambers.

10. Injector device according to any of the preceding claims, characterized in that the pressure chamber has a larger volume than the liquid volume in the storage chamber, after optional mixing.

11. Injector device according to any of the preceding claims, characterized in that the liquid connection comprises a by-pass structure for the piston.

12. Injector device according to any of the preceding claims, characterized in that said mechanism (8) is acting on a rear piston (20).

13. Injector device according to any of the preceding claims, characterized in that said mechanism (8) comprises a mechanical spring or pressurized gas.

14. Injector device according to any of the preceding claims, characterized in that said mechanism (8) is also arranged for transfer of liquid.

16. Injector device according to claim 15, characterized in that the relative positions are arranged to allow, during the chamber aggregate rearward movement, at least the transfer of liquid form the storage chamber to the pressure chamber, and optionally a de-aeration of the pressure chamber, and allow, during the plunger forward movement, ejection of liquid from the pressure chamber.

17. Injector device according to claim 15, characterized in that the rearward movement of the chamber aggregate is arranged for manual actuation, preferably involving a screw-threaded connection.

18. Injector device according to claim 17, characterized in that the forward movement of the plunger is arranged for triggered release of stored energy, preferably of compressed gas or compressed mechanical spring.

20. Pressure chamber according to claim 13, characterized in that said chamber is made from plastic.

21. Pressure chamber according to claim 19 or 20, characterized in that it is provided with a liquid connection between the pressure chamber and the storage chamber allowing transfer of the liquid from the storage chamber to the pressure chamber.

22. Pressure chamber according to claim 21, characterized in that the liquid connection comprises a by-pass arrangement on the pressure barrel, allowing passage of liquid around the piston.

23. Pressure chamber according to claim 19 or 22, characterized in an area to the rear of the liquid connection adapted for a seal between the pressure chamber and the storage chamber.

24. Injector device or pressure chamber according to any preceding claims, characterized in that a hypodermic needle is attached in connection with the front end opening to be able to perform a hypodermic injection.

26. The method of claim 25, characterized in that the relative movement between the chamber assembly and the pressurizing mechanism is performed while the pressurizing mechanism is idle.

27. The method of claim 26, characterized in that step iv) is performed by activation of the pressurizing mechanism while the chamber assembly is kept stationary with respect to the pressurizing mechanism.

29. Method according to claim 28, characterized in that the pressure chamber initially being substantially gas filled.

30. Method according to claim 18 or 19, characterized in that before step i), mixing components in storage chamber to create the liquid.

15. An injector device for delivery of liquid from a high pressure source, the device comprising

a) a pressure chamber (4) comprising a pressure barrel (10) of substantially constant cross-section, defining a pressure chamber axis (12), for accommodation of at least one piston therein and having a front end opening (14) for ejection of the liquid, the pressure chamber being of sufficient strength to sustain the liquid pressure;

b) a storage chamber (6), for the liquid or the liquid precursor components, comprising a storage barrel (16) with at least a section of substantially constant cross-section, defining a storage chamber axis (18), for accommodation of at least one piston (20,22) therein, optionally with a by-pass section therein;

c) a liquid connection (24) between the pressure chamber and the storage chamber allowing transfer of the liquid from the storage chamber to the pressure chamber;

e) at least a front piston and a rear piston arranged for travel in the pressure barrel and storage barrel,

d) a mechanism (8) arranged to apply force, directly or indirectly, on the piston when in the pressure barrel to create said liquid pressure, characterized in the improvement comprising,

i) that the pressure chamber axis and the storage chamber axis substantially coincide to form a chamber aggregate;

ii) that the mechanism (8) comprises a plunger (28), arranged axially movable in at least the forward direction with respect to a device part, forming a reference point for the movement,

iii) that the chamber aggregate is connected axially movable in at least the rearward direction with respect to the reference point and

iv) that the relative positions of the plunger and the chamber aggregate with respect to the reference points allow the chamber aggregate to perform the rearward movement with plunger and rear piston in contact while the plunger is kept stationary and allow the plunger to perform the forward movement in contact with the rear plunger while the chamber aggregate is kept stationary.

19. A pressure chamber to be used for jet injection of a liquid medicine comprising

a pressure barrel of substantially constant cross-section, for accommodation of at least one piston therein, and having a front end opening for ejection of the liquid, the pressure chamber being of sufficient strength to sustain the liquid pressure, wherein said pressure barrel is provided with an open rear end adapted to receive a storage chamber, for the liquid or the liquid precursor components

25. Method of performing an injection of a liquid medicine, the method comprises the following steps:

i) assembling a medicine storage chamber, defining a storage chamber axis, containing liquid medicine and a pressure chamber, defining a pressure chamber axis, to form a chamber assembly so that said axes coincide;

ii) arranging the chamber assembly in relation with an injection device having a pressurizing mechanism arranged to generate a force;

iii) transferring the liquid medicine into the pressure chamber by relative movement between the chamber assembly and said pressurizing mechanism, and

iv) applying the necessary force from said pressurizing mechanism on the pressure chamber to perform the injection.

28. Method of performing an injection by an injector device for delivery of liquid from a high pressure source, the method comprising the steps of:

a) confining the liquid, or the liquid precursor components, in a storage chamber,

b) transferring the liquid from the storage chamber to a pressure chamber, initially containing gas, the pressure chamber having an opening for ejection of the liquid, the pressure chamber being of sufficient strength to sustain the liquid pressure, and

c) pressurizing the pressure chamber to create the liquid pressure, characterized in the improvement comprising the steps of

i) maintaining an initial content of gas in the pressure chamber,

ii) transferring the liquid from the storage chamber to the pressure chamber to displace gas contained therein through the front end opening, and

iii) pressurizing the liquid in the pressure chamber for delivery of liquid through the opening while keeping the storage chamber stationary with respect to the pressure chamber.

31. Method according to any of claims 28-30, characterized in that the force in step iii) being higher than in step ii).

32. Method according to any of claims 28-31, characterized in that the pressure chamber comprises a pressure barrel of substantially constant cross-section for accommodation of at least one piston therein and that the transferring step comprises the step of passing the liquid past the piston.

33. Method according to claim 32, characterized in that the storage chamber comprises a storage barrel of substantially constant cross-section for accommodation of at least one piston therein, that the passing step comprises the step of moving the liquid by moving a second piston inserted in the storage barrel forwards.

34. Method according to claim 33, characterized in that the pressurizing step include the step of moving the piston and the second piston together forwards in the pressure barrel.