Medical injection system and method, gas spring thereof and launching device using gas spring

• US 5,919,159 A
• Filed: 01/09/1997
• Issued: 07/06/1999
• Est. Priority Date: 01/09/1995
• Status: Expired due to Fees

• Current Assignee: Antares Pharma Incorporated
• Original Assignee: Medi-Ject Corporation
• Inventors: Johnson, Thomas R., Lilley, Stephen John, Theobald, David Reginald, Taylor, Hugh Francis, Carlson, Craig J., Rosen, David I.
• Primary Examiner(s): McDermott, Corrine
• Assistant Examiner(s): RODRIGUEZ, CRIS LOIREN
• Application Number:
  US08/780,920
• Time in Patent Office: 908 Days
• Field of Search: 604/68-70, 604/134, 604/135, 604/140, 604/143, 604/141, 604/145, 604/146, 604/147, 604/207, 604/208
• US Class Current: 604/70
• CPC Class Codes: A61J 1/201 having one piercing end
• CPC Class Codes: A61J 1/2044 having slits
• CPC Class Codes: A61J 1/2051 having tap means, e.g. tap means activated by sliding
• CPC Class Codes: A61J 1/2055 having gripping means
• CPC Class Codes: A61J 1/2096 Combination of a vial and a syringe for transferring or mixing their contents
• CPC Class Codes: A61M 5/2053 Media being expelled from injector by pressurised fluid or vacuum for infusion A61M5/145, A61M5/155
• 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: F41B 11/64 having a piston effecting a compressor stroke during the firing of each shot
• CPC Class Codes: F41B 11/642 the piston being spring operated
• CPC Class Codes: F41B 11/646 Arrangements for putting the spring under tension
• CPC Class Codes: F41B 11/81 for ejecting powder, e.g. pepper

Abstract

A needleless injection system and method for injecting a medical product comprises a needleless injection device having a nozzle assembly defining an ampule chamber for holding medication, an energy device for pushing medication out of the nozzle assembly, and an energy device actuating mechanism. These components are operatively contained in a housing configured for a hand held operation. The energy device is a self-contained gas spring operatively connected to a plunger operating within the ampule chamber. The gas spring is preferably stepped which can be used in many different applications, an air gun being one. The injection device can be provide with a coupling device for coupling a medication supply vial to the nozzle assembly. The nozzle assembly is removably situated in the housing with the plunger removable therewith.

Claims

1. Device for injecting a medical product comprising:

a nozzle assembly having a chamber for holding the medical product, an orifice in said nozzle assembly in fluid communication with said chamber for allowing passage of the medical product through said orifice, and a pressure wall member disposed and movable within said chamber holding the medical product; and

an energy mechanism operatively associated with said pressure wall member for moving said pressure wall member at a speed sufficient to eject the medical product from said chamber under a pressure which is sufficient to pierce at least one layer of skin, said energy mechanism comprising a liquid-free gas spring.

2. Device according to claim 1, wherein said nozzle assembly is prefilled with the medical product.

3. Device according to claim 1, wherein at least one of said nozzle assembly and said pressure wall member are formed of stainless, polycarboriate, polypropylene and derivatives thereof or any suitable plastic, glass or composite that is compatible with the medical product and capable of withstanding pressure and stress subjected thereto.

4. Device for injecting a medical product comprising:

a nozzle assembly having a chamber for holding the medical product, an orifice in said nozzle assembly in fluid communication with said chamber for allowing passage of the medical product through said orifice, and a pressure wall member disposed and movable within said chamber holding the medical product; and

an energy mechanism operatively associated with said pressure wall member for moving said pressure wall member at a speed sufficient to eject the medical product from said chamber under a pressure which is sufficient to pierce at least one layer of skin, said enery mechanism comprising a gas spring having a gas spring pressure chamber defined by a tubular sleeve and a pair of end plugs sealingly enclosing said tubular sleeve, and a piston extending through said end plugs and occupying a portion of said gas spring chamber, said gas spring chamber beeing pressurized with gas, and said piston being sealed relative to said end plugs but slidable relative thereto.

5. Device according to claim 4, wherein said piston has a first piston portion and a second piston portion, said first piston portion being larger than said second piston portion, wherein at least a portion of said second piston portion occupies said gas spring chamber when said piston is at its neutral condition, said gas spring chamber being further compressed by moving said first piston portion into said gas spring chamber.

6. Device according to claim 5, wherein said first piston portion is at least twice the diameter of said second piston portion.

7. Device according to claim 5, wherein said first piston portion is operatively connected to said pressure wall member.

8. Device according to claim 7, wherein said pressure wall member is a plunger.

9. Device according to claim 8, further comprising a lost motion connection mechanism connected between said plunger and said piston, wherein said lost motion connection mechanism provides a predetermined free play between said plunger and said piston, wherein said lost motion connection mechanism enables said piston to move a predetermined distance before said piston moves said plunger.

10. Device according to claim 9, wherein said lost motion connection mechanism comprises a ram having a longitudinal slot connected to said piston, wherein said plunger further includes a connector shaft connected to an end of said ram, said shaft being able to occupy said slot and slide relative thereto, said shaft having a predetermined length to provide a predetermined gap between an end of said plunger and said end of said ram, wherein said end of said ram engages said plunger after said gap is first closed.

11. Device according to claim 10, wherein said quick release connector extends from said plunger and said enlarged end is connected to said piston, wherein said quick release connector has at least one prong made of resilient material, which upon being attached to said enlarged head expands and returns to its original configuration.

12. Device according to claim 11, wherein said quick release connector includes a plurality of prongs, each extending from said plunger, each of said prongs having a tab extending radially inwardly and confines said enlarged end connected to said plunger, wherein said prongs are confined within said ampule chamber, said prongs being dimensioned to slide inside said ampule chamber and an inner wall of said ampule chamber confining said prongs from moving laterally outwardly to maintain said enlarged end locked to said plunger during use, wherein said plunger is disconnected by first disconnecting said nozzle assembly from the device to expose said prongs, wherein said plunger is disconnected by pulling said plunger off said enlarged end.

13. Device according to claim 9, wherein said lost motion connection mechanism comprises a resilient quick release connector formed on one of ends of said plunger and said piston and an enlarged end at the other of the ends of said plunger and said piston.

14. Device according to claim 8, further comprising means for removably connecting said plunger to said piston.

15. Device according to claim 14, wherein said removable connecting means further includes means for providing a free play between said plunger and said piston.

16. Device according to claim 14, wherein at least one of said nozzle assembly and said plunger are formed of stainless steel, polycarbonate, polypropylene and derivatives thereof or any suitable plastic, glass or composite that is compatible with the medical product and capable of withstanding pressure and stress subjected thereto.

17. Device according to claim 4, wherein energy mechanism includes a trigger mechanism for operatively and selectively engaging and disengaging said piston to selectively retain said gas spring in a locked compressed condition and for selectively releasing said gas spring into its released neutral condition.

18. Device according to claim 5, wherein said energy mechanism includes a gas spring coupling mechanism connected to a free end of said second piston portion, wherein said trigger mechanism selectively engages and disengages said coupling mechanism.

19. Device according to claim 18, further comprising a housing for containing said nozzle assembly and said gas spring.

20. Device according to claim 19, wherein said housing is formed of a liquid crystal polymer.

21. Device according to claim 19, wherein said energy mechanism further comprises an actuating mechanism connected to said housing and said trigger mechanism, wherein said actuating mechanism is movable with said trigger mechanism relative said housing, wherein said actuating mechanism is movable toward and away relative to said sleeve with said trigger mechanism engaged to said coupling mechanism to pull said first piston portion into said gas spring chamber to further compress said gas spring chamber.

22. Device according to claim 18, further comprising a housing for containing said gas spring, said housing being connected to said trigger mechanism.

23. Device according to claim 22, wherein said housing is formed of a liquid crystal polymer.

24. Device according to claim 22, wherein said energy mechanism further comprises an actuating mechanism connected to said housing, wherein said actuating mechanism is movably connected to said housing as to be movable toward and away relative to said sleeve, wherein said actuating mechanism compresses said gas spring by pushing said first piston portion into said pressure chamber and moves said gas spring coupling mechanism into said trigger mechanism to hold said gas spring in said compressed condition.

25. Device according to claim 24, wherein said nozzle assembly is connected to said actuating mechanism.

26. Device according to claim 25, wherein said nozzle assembly has means for removably connecting to an end of said actuating mechanism.

27. Device for injecting a medical product comprising:

a nozzle assembly having a chamber for holding the medical product, an orifice in said nozzle assembly in fluid communication with said chamber for allowing passage of the medical product through said orifice, and a pressure wall member disposed and movable within said chamber holding the medical product; and

energy means operatively associated with said pressure wall member for moving said pressure wall member at a speed sufficient to eject the medical product from said chamber under a pressure which is sufficient to pierce at least one layer of skin said energy means comprising a gas stepped spring.