Patent EA-004185-B1 (EA)
Title: Medical arrangement
Inventor: HJERTMAN BIRGER
IPC: A61M5/30
Filed: 2001-05-22
Abstract: 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. 14. Injector unit according to any of claims 1-13, characterized in that a fitting connection contains a screw and a thread. 15. Injector unit according to any of claims 1-13, characterized in that said fitting connection between the unit and the housing is achieved by a clamping connection. 16. 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. 17. Injector unit according to claim 16, 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. 18. Injector unit according to claim 17, characterized in that said piston rod is provided with a central channel for transfer of liquid from the storage chamber to the pressure chamber. 19. Injector unit according to claim 18, 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. 20. Injector unit according to claim 19, 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. Injector unit according to any of claims 16-20, characterized in that said fitting parts comprises a corresponding screw and thread. 22. Injector unit according to any of claims 16-20, characterized in that said fitting connection between the unit and the housing is achieved by a clamping connection. 23. 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) moving the piston forwards with respect to the pressure chamber to substantially displace the gas therein through the front end opening and iii) pressurizing the liquid in the pressure chamber for delivery of liquid through the opening. 24. Method according to claim 23, characterized in that before step i) components are mixed in the storage chamber to create the liquid. 25. Method according to any of claims 21-22, characterized in that the force in step iii) being higher than in step ii) 26. Method according to any of claims 23-25, characterized in that the pressure chamber initially being substantially gas filled. 27. Method according to any of claims 23-26, characterized in that the pressurizing step takes place while keeping the storage chamber stationary with respect to the pressure chamber. 28. Method according to any of claims 23-27, characterized in that the transferring step comprises the step of passing the liquid past the piston. 29. Method according to claim 28, 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. 30. Method according to any of claims 23-29, characterized in that the transferring step (i) and the moving step (ii) are performed in sequence during a single manual movement. 31. Method according to any of claims 23-30, characterized in that the transferring step (i) is preceded by a dose setting step. 32. 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. 33. The device of claim 32, characterized in that the de-aeration mechanism is