Automatic pharmaceutical dispensing syringe

• US 5,320,609 A
• Filed: 12/07/1992
• Issued: 06/14/1994
• Est. Priority Date: 12/07/1992
• Status: Expired due to Term

• Current Assignee: Eli Lilly and Company
• Original Assignee: Habley Medical Technology Corporation
• Inventors: Foster, Clark B., Smedley, William H., Haber, Terry M.
• Primary Examiner(s): Hirsch, Paul J.
• Application Number:
  US07/987,475
• Time in Patent Office: 554 Days
• Field of Search: 604/135, 604/136, 604/134, 604/137, 604/131
• US Class Current: 604/135
• CPC Class Codes: A61M 2005/202 cocking means, e.g. to bias the main drive spring of an injector
• CPC Class Codes: A61M 2005/206 With automatic needle insertion
• CPC Class Codes: A61M 2005/3104 Caps for syringes without needle
• CPC Class Codes: A61M 2005/3151 by friction
• CPC Class Codes: A61M 5/2033 Spring-loaded one-shot injectors with or without automatic needle insertion multishot dosing syringes A61M5/31525, needle insertion only A61M5/3287
• 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 5/31551 including axial movement of dose setting member
• CPC Class Codes: A61M 5/31583 based on rotational translation, i.e. movement of piston rod is caused by relative rotation between the user activated actuator and the piston rod
• CPC Class Codes: A61M 5/3202 Devices for protection of the needle before use, e.g. caps A61M5/50 takes precedence; for infusion spikes A61M5/1626; protectors for sharps A61B50/3001

Abstract

An automatic pharmaceutical dispensing syringe (2), includes a main barrel (4) having hollow interior (18) sized to house a conventional pharmaceutical cartridge (16) and needle (6). A cap (6) at one end (8) of the main barrel is used to rotate a threaded dosing screw (158) housed within the main barrel. The dosing screw is permitted to move axially within the main barrel. The dosing screw threads (156) engage similar threads (146) on an elongate piston driver (140) which abuts the cartridge piston (152). A brake pad (194) secures the piston driver to the main barrel while the cap is rotated to select the desired dose. Doing so causes the dosing screw to move axially relative to the piston driver to compress an injection spring (174). The injection sequence is begun by placing the distal end (114) of an outer sleeve (10) surrounding the main barrel against the patient and pressing a trigger (130). This permits a needle insertion spring (106), captured between the main barrel and the outer sleeve, to drive the main barrel, cartridge and needle assembly distally, thus driving the needle into the patient. Only at the end of travel does the brake pad release the piston driver to permit the injection spring to drive the piston driver against the piston thus forcing the pharmaceutical through the needle and into the patient.

Claims

1. A pharmaceutical dispensing syringe, for use with a needle assembly and a cartridge of the type having a cartridge barrel, an open end, a needle end to which the needle assembly is mountable, a piston within the barrel and a flowable pharmaceutical within the barrel between the piston and the needle end, the needle assembly having a tip, the syringe comprising:

a main barrel having a proximal end, a distal end and a hollow interior sized to house the cartridge therein, the tip of the needle assembly extending past the distal end;

a user manipulatable cap rotationally mounted to the proximal end of the barrel;

a dosing screw, including dosing screw threads, rotationally driven by the cap whereby rotation of the cap allows the user to select a dose of the pharmaceutical to be dispensed through the needle assembly;

a piston driver threadably coupled to the dosing screw and having a distal driver end engaging the piston;

a dosing spring captured between the cap and dosing screw, the dosing spring biasing the piston driver against the piston;

a user actuated brake device selectively securing the piston driver to the main barrel to prevent relative axial movement therebetween until released by the user;

an outer sleeve slidably mounted over the main barrel and movable between a safe position, with the outer sleeve enclosing the needle assembly, and a use position, with the tip of the needle assembly exposed;

an injection spring captured between the main barrel and the outer sleeve biasing the main barrel, cartridge and needle assembly in a distal direction relative to the outer sleeve; and

a release trigger mounted within an opening in the outer sleeve, the trigger, when the outer sleeve is in the safe position, preventing the injection spring from driving the main barrel, cartridge and needle assembly in a distal direction until released by the user.

2. The syringe of claim 1 wherein:

the dosing screw threads are external threads;

the piston driver is hollow and has internal threads which mate with the external threads of the dosing screw; and

the dosing screw is coupled to the cap using a radially extending drive element on the cap which engages an axially extending groove formed in the dosing screw.

3. The syringe of claim 1 wherein the brake device includes a brake pad housed within a window formed in the main barrel, the brake pad movable between a brake applied position and a brake released position by movement of the outer sleeve between the safe position and the use position.

4. The syringe of claim 1 further comprising a dosing indicator operably coupled to the dosing screw.

5. The syringe of claim 4 wherein the dosing indicator includes:

a stem having a dose indicator thread;

an indicator head secured to the stem; and

a dose indicator drive nut secured to the dosing screw and threadably engaging the dose indicator thread so that rotating the cap causes relative rotary motion between the cap and the indicator head.

6. The syringe of claim 5 wherein the cap includes a top cap including a transparent region and a hollow interior, the indicator head being housed within the hollow interior.

7. The syringe of claim 6 wherein one of the top cap and the indicator head includes dose indicia and the other of the top cap and the indicator head includes a dose indicator marker positioned to align with the dose indicia according to the dose to be dispensed.

8. The syringe of claim 6 wherein the indicator head is disc-shaped.

9. The syringe of claim 5 wherein the pitch of the indicator thread is at least two times the pitch of the dosing screw threads so that the relative rotary motion between the cap and the main barrel is at least two times the relative rotary motion between the cap and the indicator head.

10. The syringe of claim 3 wherein the outer sleeve encloses the needle assembly when the outer sleeve is in the brake applied position, and the tip of the needle assembly is exposed when the outer sleeve is in the brake released position.

11. The syringe of claim 10 wherein the injection spring, when released by the release trigger, drives the main barrel, cartridge and needle assembly therewith within the outer sleeve from the brake applied position of the outer sleeve to the brake released position of the outer sleeve permitting the tip of the needle assembly to be driven into the patient during said movement and substantially releasing the piston driver from the main barrel at the end of said movement to permit the dosing spring to drive the piston driver toward the piston according to the rotary position of the cap.

12. A pharmaceutical dispensing syringe, for use with a needle assembly and a cartridge of the type having a cartridge barrel, an open end, a needle end to which the needle assembly is mountable, a piston within the barrel and a flowable pharmaceutical within the barrel between the piston and the needle end, the needle assembly having a tip, the syringe comprising:

a main barrel having a proximal end, a distal end and a hollow interior sized to house the cartridge therein, the tip of the needle assembly extending past the distal end;

a user manipulatable cap rotationally mounted to the proximal end of the barrel;

a dosing screw, including dosing screw threads, housed within the main barrel and rotationally driven by the cap, the dosing screw being coupled to the cap to permit relative axial movement therebetween;

a piston driver threadably coupled to the dosing screw threads and having a distal driver end continuously engaging the piston;

means for biasing the piston driver towards the piston; and

means for preventing the piston driver from rotating within the main barrel so that rotary motion of the cap causes rotary motion of the dosing screw which causes relative axial motion between the dosing screw and the piston driver.

13. The syringe of claim 12 wherein:

the dosing screw has external threads;

the piston driver is hollow and has internal threads which mate with the external threads of the dosing screw;

the dosing screw is coupled to the cap using a radially extending drive element on the cap which engages an axially extending groove formed in the dosing screw; and

the biasing means includes a compression coil spring captured between the cap and the dosing screw.

14. The syringe of claim 12 further comprising a user actuated brake device selectively securing the piston driver to the main barrel to prevent relative axial movement therebetween until the brake device is released by the user.

15. The syringe of claim 14 wherein the brake device includes a brake pad housed within a window formed in main barrel and a slidable outer sleeve slidably mounted over the main barrel for movement between a brake applied position, at which the brake pad frictionally secures the piston driver to the main barrel, and a brake released position, at which the brake pad substantially releases the piston driver from the main barrel.

16. The syringe of claim 12 further comprising a dosing indicator operably coupled to the dosing screw.

17. The syringe of claim 16 wherein the dosing indicator includes:

a stem having a dose indicator thread;

an indicator head secured to the stem; and

a dose indicator drive nut secured to the dosing screw and threadably engaging the dose indicator thread so that rotating the cap causes relative rotary motion between the cap and the indicator head.

18. The syringe of claim 17 wherein:

the cap includes a top cap including a transparent region and a hollow interior, the indicator head being housed within the hollow interior; and

one of the top cap and the indicator head includes dose indicia and the other of the top cap and the indicator head includes a dose indicator marker positioned to align with the dose indicia according to the dose to be dispensed.

19. The syringe of claim 12 further comprising an outer sleeve, having sleeve distal and sleeve proximal ends, slidably mounted over the main barrel and movable between a safe position, with the outer sleeve enclosing the needle assembly, and a use position, with the tip of the needle assembly exposed.

20. The syringe of claim 19 further comprising user actuated means for driving the main barrel, cartridge and needle assembly therewith within the outer sleeve from the safe position to the use position permitting the tip of the needle assembly to be driven into the patient.

21. The syringe of claim 15 wherein the outer sleeve encloses the needle assembly when the outer sleeve is in the brake applied position, and the tip of the needle assembly is exposed when the outer sleeve is in the brake applied position.

22. The syringe of claim 21 further comprising user actuated means for driving the main barrel, cartridge and needle assembly therewith within the outer sleeve from the brake applied position of the outer sleeve to the brake released position of the outer sleeve permitting the tip of the needle assembly to be driven into the patient during said movement and substantially releasing the piston driver from the main barrel at the end of said movement to permit the piston driver biasing means to drive the piston drives toward the piston according to the rotary position of the cap.

23. A pharmaceutical dispensing syringe, for use with a needle assembly and a cartridge of the type having a cartridge barrel, an open end, a needle end to which the needle assembly is mountable, a piston within the barrel and a flowable pharmaceutical within the barrel between the piston and the needle end, the needle assembly having a tip, the syringe comprising:

a main barrel having a proximal end, a distal end and a hollow interior sized to house the cartridge therein, the tip of the needle assembly extending past the distal end;

a user manipulatable cap rotationally mounted to the proximal end of the barrel;

a dosing screw, including dosing screw threads, housed within the main barrel and rotationally driven by the cap, the dosing screw being coupled to the cap to permit relative axial movement therebetween;

a piston driver threadably coupled to the dosing screw threads and having a distal driver end engaging the piston;

means for biasing the piston driver towards the piston;

means for preventing the piston driver from rotating within the main barrel so that rotary motion of the cap causes rotary motion of the dosing screw which causes relative axial motion between the dosing screw and the piston driver;

an outer sleeve slidably mounted over the main barrel movable between a safe position, at which the outer sleeve covers the tip of the needle assembly, and a use position, at which the tip of the needle is exposed;

a brake pad housed with a window formed between the main barrel and the outer sleeve for movement between a brake applied position, at which the brake pad frictionally secures the piston driver to the main barrel, and a brake released position, at which the brake pad substantially releases the piston driver from the main barrel; and

a brake actuator element which keeps the brake pad in the brake applied position until the outer sleeve is at the use position.

24. The syringe of claim 23 further comprising a dosing indicator, operably coupled to the dosing screw, the dosing indicator including:

a stem having a dose indicator thread;

an indicator head secured to the stem; and

a dose indicator drive nut secured to the dosing screw and threadably engaging the dose indicator thread so that rotating the cap causes relative rotary motion between the cap and the indicator head.

25. A method for automatically dispensing a desired dose of liquid pharmaceutical from a cartridge, of the type having a body with an open end, a needle end, a piston within the body and a flowable pharmaceutical within the body between the piston and the needle end, through the needle of a needle assembly fluidly coupled to the body, the method comprising the steps of:

providing a main barrel having a proximal end, a distal end and a hollow interior sized to house the cartridge therein;

sliding an outer sleeve slidably mounted over the barrel from a use position, with the needle being exposed, to a safe position, with the outer sleeve enclosing the needle, to compress an injection spring captured between the outer sleeve and the main barrel;

securing the injection spring when the outer sleeve is in the safe position;

securing a piston driver to the main barrel to prevent relative axial movement therebetween;

placing a distal end of the outer sleeve against a patient;

rotating a cap mounted to the proximal end of the barrel to compress a dosing spring;

releasing the injection spring;

driving the main barrel, cartridge and needle assembly in a distal direction so to inject the needle into a patient;

releasing the piston driver after the needle is injected into the patient; and

driving the piston driver against the piston to force the desired dose of pharmaceutical within the cartridge through the needle and into the patient.

26. The method of claim 25 wherein the injection spring securing step is carried out with a trigger mounted in an opening in the outer sleeve.

27. The method of claim 25 wherein the piston driver securing step includes the step of moving a brake device housed within a window formed within the main barrel from a brake release position to a brake applied position.

28. The method of claim 25 wherein the rotating step is carried out with a dosing screw coupled to the cap so that the dosing screw moves in an axial direction when the cap is rotated, the dosing screw being threadably coupled to the piston driver, the dosing spring being captured between the cap and the dosing screw.

29. The method of claim 26 wherein the injection spring releasing step includes the step of pressing the trigger.

30. The method of claim 27 wherein the piston driver releasing step includes the step of moving the brake device from the brake applied position to the brake release position.

31. A pharmaceutical dispensing syringe, for use with a needle assembly and a cartridge of the type having a cartridge barrel, an open end, a needle end to which the needle assembly is mountable, a piston within the barrel and a flowable pharmaceutical within the barrel between the piston and the needle end, the needle assembly having a tip, the syringe comprising:

a main barrel having a proximal end, a distal end and a hollow interior sized to house the cartridge therein, the tip of the needle assembly extending past the distal end;

a piston driver having a distal driver and engagable with the piston;

means, operably coupled with the piston driver, for selecting a dose of the pharmaceutical to be dispensed through the needle assembly;

first driving means for driving the tip of the needle assembly into a patient; and

second driving means, separate from the first driving means, for driving the piston driver against the piston a selected distance, corresponding to the selected dose, after the first driving means has driven the tip of the needle assembly into the patient.

32. The syringe of claim 31 wherein the selecting means includes:

a user manipulatable cap rotationally mounted to the proximal end of the barrel; and

a dosing screw, including dosing screw threads, rotationally driven by the cap, the dosing screw threadably coupled to the piston driver.

33. The syringe of claim 32 wherein the first driving means includes:

a dosing spring captured between the cap and dosing screw, the dosing spring biasing the piston driver against the piston;

means for preventing the piston driver from rotating within the main barrel so that rotary motion of the cap causes rotary motion of the dosing screw which causes relative axial motion between the dosing screw and the piston driver; and

a user actuated brake device selectively securing the piston driver to the main barrel to prevent relative axial motion therebetween until released by the user.

34. The syringe of claim 31 wherein the second driving means includes:

an outer sleeve slidably mounted over the main barrel and movable between a safe position, with the outer sleeve enclosing the needle assembly, and a use position, with the tip of the needle assembly exposed;

an injection spring captured between the main barrel and the outer sleeve biasing the main barrel, cartridge and needle assembly in a distal direction relative to the outer sleeve; and

a release trigger mounted within an opening in the outer sleeve, the trigger, when the outer sleeve is in the safe position, preventing the injection spring from driving the main barrel, cartridge and needle assembly in a distal direction until released by the user.