Medical arrangement

• US 20020007142A1
• Filed: 05/22/2001
• Published: 01/17/2002
• Est. Priority Date: 05/22/2000
• Status: Active Grant

• Current Assignee: Pharmacia AB (Pharmacia Corp.)
• Original Assignee: Pharmacia AB (Pharmacia Corp.)
• Inventors: Hjertman, Birger, Fridholm, Jonas
• Granted Patent: US 6,689,101 B2
• Time in Patent Office: Days
• US Class Current: 604/38
• CPC Class Codes: A61M 2005/3152 including gearings to multiply or attenuate the piston displacing force
• CPC Class Codes: A61M 5/204 connected to external reservoirs for multiple refilling
• CPC Class Codes: A61M 5/24 Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or carpules, e.g. automatic ampoules or carpules A61J1/06
• CPC Class Codes: A61M 5/30 Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules
• CPC Class Codes: A61M 5/502 for blocking the piston

Abstract

An injector device for delivery of liquid from a high pressure, the device comprising a housing, a pressure chamber 2 comprising a pressure barrel 4 for accommodation of at least one piston therein and having a front end opening 6 for ejection of the liquid, the pressure chamber being of sufficient strength to sustain the liquid pressure. The device further comprises a storage chamber 16, separate from the pressure chamber, for the liquid or the liquid precursor components, and a conduit 22 between the pressure chamber and the storage chamber. A pressurizing mechanism 26 in the housing is arranged to apply force, directly or indirectly, on the piston in the pressure barrel to create said liquid pressure. The pressure chamber, the piston and at least a part of the conduit is arranged as a unit, wherein said unit and the housing have corresponding fitting parts allowing releasable attachment of the unit to the housing in a position permitting fluid connection between storage chamber and pressure chamber through the conduit and permitting the pressurizing mechanism to act on the piston.

Claims

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

a) a housing,

b) a pressure chamber (2) comprising a pressure barrel (4) for accommodation of at least one piston therein and having a front end opening (6) for ejection of the liquid, the pressure chamber being of sufficient strength to sustain the liquid pressure,

c) a piston (12) inserted in the pressure barrel,

d) a storage chamber (16), separate from the pressure chamber, for the liquid or the liquid precursor components,

e) a conduit (22) between the pressure chamber and the storage chamber,

f) a pressurizing mechanism (26) in the housing arranged to apply force, directly or indirectly, on the piston in the pressure barrel to create said liquid pressure,

characterized in the improvement comprising,

i) that the pressure chamber, the piston and at least a part of the conduit is arranged as a unit, and

ii) that the unit and the housing have corresponding fitting parts allowing releasable attachment of the unit to the housing in a position permitting fluid connection between storage chamber and pressure chamber through the conduit and permitting the pressurizing mechanism to act on the piston.

2. Injector device according to claim 1, characterized in that said piston in said pressure chamber is adapted to be moved from a medicine loading position where the liquid medicine is loaded into the pressure chamber from the storage chamber via said liquid conduit to a sealed position where the liquid conduit is closed.

3. Injector device according to claim 2, characterized in that air inside the pressure chamber is expelled when the piston is in the sealed position.

4. Injector device according to claim 3, characterized in that said device further comprises a control arrangement that in dependence of the volume transferred from the storage chamber to the pressure chamber controls the movement of the piston from the loading position to the sealing position so that substantially all air is expelled from the pressure chamber.

5. Injector device according to any preceding claim, characterized in that said device further comprises a dosing unit arranged to transfer an adjustable volume of liquid from the storage chamber into the pressure chamber.

6. Injector device according to any preceding claim, characterized in that the volume of liquid medicine stored in the storage chamber represents a plurality of injection doses.

7. Injector device according to any preceding claim, characterized in that the conduit comprises a by-pass section allowing liquid passage around the piston

8. Injector device according to any preceding claim, characterized in that the storage chamber is in fixed position relative the housing.

9. Injector device according to any preceding claim, characterized in that the pressurizing mechanism acts on the piston via a piston rod which can be separated from the piston to create part of the conduit and that the conduit comprises a needle attached to the piston rod for movement therewith.

10. Injector device according to claim 9, characterized in that said piston rod is provided with a central channel for transfer of liquid from the storage chamber to the pressure chamber.

11. Injector device according to claim 10, characterized in that said piston rod is provided with a needle having a channel in connection with said central channel in order to penetrate a sealing membrane of said storage chamber.

12. Injector device according to any of claims 9-11, characterized in that the distal part of the piston rod is provided with a sealer, preferably made from resilient rubber, that in the loading position engages the inner surface of the pressure barrel in order to achieve a fluid tight connection for the liquid conduit.

13. Injector device according to any preceding claim, characterized in that said separate unit is disposable.

19. Injector device according to any of claims 1-13 or an injector unit according to any of claims 14-18, characterized in that said fitting parts comprises a corresponding screw and thread.

20. Injector device according to any of claims 1-13 or an injector unit according 10 to any of claims 14-18, characterized in that said fitting connection between the unit and the housing is achieved by a clamping connection.

14. Injector unit adapted for releasable attachment to an injector housing for delivery of liquid from a high pressure, the unit comprising

a pressure chamber with a pressure barrel 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 liquid pressure,

a piston inserted in the pressure barrel, and

a conduit between the pressure chamber and a storage chamber, that when in the releasable attachment to the housing in a position permitting fluid connection between the storage chamber and the pressure chamber through the conduit and permitting a pressurizing mechanism to act on the piston.

15. Injector unit according to claim 14, characterized in that the pressurizing mechanism acts on the piston via a piston rod in the pressure chamber which can be separated from the piston to create part of the conduit and that the conduit comprises a needle attached to the piston rod for movement therewith.

16. Injector unit according to claim 15, characterized in that said piston rod is provided with a central channel for transfer of liquid from the storage chamber to the pressure chamber.

17. Injector unit according to claim 16, characterized in that said piston rod is provided with a needle having a channel in connection with said central channel in order to penetrate a sealing membrane of said storage chamber.

18. Injector unit according to claim 17, characterized in that the distal part of the piston rod is provided with a sealer, preferably made from resilient rubber, that in the loading position engages the inner surface of the pressure barrel in order to achieve a fluid tight connection for the liquid conduit.

21. A method 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 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, and

c) pressurizing the pressure chamber by action on the piston in the pressure barrel to create the liquid pressure,

characterized in the improvement comprising the steps of

i) transferring the liquid from the storage chamber to the pressure chamber to only partially fill out the pressure chamber with liquid,

ii) after step i) moving the piston forwards with respect to the pressure chamber to substantially displace the gas therein through the front end opening and

iii) after step ii) pressurizing the liquid in the pressure chamber for delivery of liquid through the opening.

22. Method according to claim 21, characterized in that before step i) components are mixed in the storage chamber to create the liquid.

23. Method according to any of claims 21-22, characterized in that the force in step iii) being higher than in step ii)

24. Method according to any of claims 21-23, characterized in that the pressure chamber initially being substantially gas filled.

25. Method according to any of claims 21-24, characterized in that the pressurizing step takes place while keeping the storage chamber stationary with respect to the pressure chamber.

26. Method according to any of claims 21-25, characterized in that the transferring step comprises the step of passing the liquid past the piston.

27. Method according to claim 26, characterized in that the storage chamber comprises a storage barrel of substantially constant cross-section for accommodation of at least one storage piston therein, that the passing step comprises the step of moving the liquid by moving a second piston inserted in the storage barrel forwards.

28. Method according to any of claims 21-27, characterized in that the transferring step (i) and the moving step (ii) are performed in sequence during a single manual movement.

29. Method according to any of claims 21-28, characterized in that the transferring step (i) is preceded by a dose setting step.

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

a) a housing,

b) a pressure chamber (2) comprising a pressure barrel (4) for accommodation of at least one piston therein and having a front end opening (6) for ejection of the liquid, the pressure chamber being of sufficient strength to sustain the liquid pressure,

c) a piston (12) inserted in the pressure barrel,

d) a storage chamber (16), separate from the pressure chamber, for the liquid or the liquid precursor components,

e) a conduit (22) between the pressure chamber and the storage chamber,

f) a pressurizing mechanism (26) in the housing arranged when triggered to apply force, directly or indirectly, on the piston in the pressure barrel to create said liquid pressure,

characterized in the improvement comprising,

i) a liquid transfer unit arranged to move a liquid dose from the storage chamber through the conduit to the pressure chamber, and

ii) a de-aeration mechanism arranged to move, directly or indirectly and with the pressurizing mechanism not triggered, the piston forwards a stroke distance at least corresponding to the volume not occupied by the liquid dose in the pressure chamber.

31. The device of claim 30, characterized in that the de-aeration mechanism is arranged in parallel with the pressurizing mechanism

32. The device of claim 30, characterized in that the de-aeration mechanism is arranged in series with the pressurizing mechanism.

33. The device of claim 32, characterized in that the de-aeration mechanism is arranged between the piston and the pressurizing mechanism.

34. The device of claim 33, characterized in that the de-aeration mechanism is arranged to move the piston by elongating between the the piston and the pressurizing mechanism.

35. The device of claim 31, characterized in that the de-aeration mechanism is arranged to the rear of the pressurizing mechanism.

36. The device of claim 35, characterized in that the de-aeration mechanism is arranged to move the piston by elongating between the the housing and the pressurizing mechanism.

37. The device of claim 36, characterized in that the de-aeration mechanism is arranged to move the piston forwards by moving the pressurizing mechanism forwards.

38. The device of claim 30, characterized in that the de-aeration mechanism is arranged to move the piston by activation of stored energy.

39. The device of claim 30, characterized in that the de-aeration mechanism is arranged to move the piston by manual energy.

40. The device of claim 30, characterized in that the pressurizing mechanism is arranged to move the piston by activation of stored energy e.g. stored in a mechanical spring or pressurized gas.

41. The device of claim 30, characterized in a control arrangement limiting the piston stroke distance imposed by the de-aeration mechanism.

42. The device of claim 41, characterized in that the stroke distance is variable.

43. The device of claim 42, characterized in that the stroke distance is variable as a function of the liquid dose moved to the pressure chamber.

44. The device of claim 43, characterized in that the function sets the stroke distance substantially to a constant length (L) minus the axial height (D) of the liquid dose when in the pressure chamber.

45. The device of claim 43, characterized in that the control arrangement is arranged to be affected by the liquid dose volume for setting the variable stroke distance.

46. The device of claim 43, characterized in that the control arrangement is designed to prevent activation of the de-aeration mechanism until transfer of the liquid dose has taken place.

47. The device of claim 42, characterized in that the stroke distance is variable by variation of a dead run for a member arranged to affect, after the dead run, directly or indirectly, the forward movement of the piston.

48. The device of claim 47, characterized in that the member is arranged to affect during the dead run the liquid transfer unit to transfer the dose.

49. The device of claim 48, characterized in that the member is arranged to perform substantially the same total movement independent of the variation of the dead run set.

50. The device of claim 30, 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.

51. The device of claim 30, characterized in that the front end opening is covered with a removable or breakable closure or sealing.

52. The device of claim 30, characterized in that the pressure chamber and storage chamber are made from different materials, preferably plastic and glass respectively.

53. The device of claim 30, characterized in that said storage chamber is a dual chamber storage chamber provided with by-pass section and at least an additional piston dividing the storage chamber into two sub-chambers.

54. The device of claim 30, characterized in that the device is arranged for multiple doses with larger space for liquid in the storage chamber than in the pressure chamber.

55. The device of claim 30, characterized in that the pressure barrel has a rear liquid transfer position for the piston, in which piston position the conduit has fluid communication with the pressure barrel in front of the piston and front sealing positions for the piston, in which piston positions no fluid communication is present.

56. The device of claim 55, characterized in that a bypass arrangement is a present in the liquid transfer position allowing liquid to pass around the piston into the pressure chamber in front of the piston.