Safety pre-filled cartridge injector

• US 7,004,929 B2
• Filed: 06/10/2002
• Issued: 02/28/2006
• Est. Priority Date: 03/29/2002
• Status: Expired due to Fees

• Current Assignee: MDC Investment Holdings Incorporated (Becton, Dickinson & Co)
• Original Assignee: MDC Investment Holdings Incorporated (Becton, Dickinson & Co)
• Inventors: Barker, John, Kovalski, Joseph, McWethy, Robert T., Challiol, Bernardo
• Primary Examiner(s): Kennedy, Sharon
• Application Number:
  US10/166,305
• Publication Number:
  US 20030229314A1
• Time in Patent Office: 1,359 Days
• Field of Search: 604/198, 604/110, 604/192, 604/195, 604/228, 604/232, 604/263
• US Class Current: 604/198
• CPC Class Codes: A61M 2005/3247 Means to impede repositioning of protection sleeve from needle covering to needle uncovering position
• CPC Class Codes: A61M 2005/3261 triggered by radial deflection of the anchoring parts between sleeve and syringe barrel, e.g. spreading of sleeve retaining hooks having slanted surfaces by engagement with conically shaped collet of the piston rod during the last portion of the injection stroke of the plunger
• 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 5/326 Fully automatic sleeve extension, i.e. in which triggering of the sleeve does not require a deliberate action by the user

Abstract

A device is provided for injecting fluid from a pre-filled cartridge. The device includes a needle and a hollow barrel that holds a pre-filled cartridge. A needle retainer releasably retains the needle in an extended position so the needle can be inserted into a patient. A plunger in the rear of the barrel cooperates with the cartridge to expel fluid from the cartridge during an injection. After an injection, the needle is automatically retracted into the barrel when pressure is released from the plunger. A locking mechanism locks the contaminated needle and cartridge in the barrel after needle retraction. After use, the device may be safely disposed of in a sharps container.

Claims

1. A medical device comprising:

a hollow barrel having a forward end;

a cartridge disposed within the barrel containing a medication;

a needle having a sharpened forward end and operable between an extended position, in which the sharpened forward end projects from the forward end of the barrel, and a retracted position, in which the sharpened forward end is enclosed within the barrel;

a plunger slidably disposed in the cartridge and operable to expel the medication from the cartridge;

a biasing element that biases the needle towards the retracted position; and

a needle retainer releasably engaging the barrel to maintain the needle in the projecting position against the force of the biasing element,

wherein axial pressure on the plunger displaces the plunger forwardly to expel medication from the cartridge and release the needle retainer from engagement with the barrel, after which the needle is automatically propelled from the extended position to the retracted position by releasing pressure on the plunger.

2. The medical device of claim 1 comprising a cartridge holder disposed around the needle and cartridge, said cartridge holder comprising a radially outwardly extending detent.

3. The medical device of claim 2, wherein the needle retainer comprises:

a resilient flexible arm attached to the barrel; and

an inwardly extending tab on the flexible arm configured to engage the detent on the cartridge holder when the needle tip is in the extended position.

4. The medical device of claim 3, wherein the plunger comprises a cylindrical sleeve having a forward end configured to displace the inwardly extending tab out of engagement with the detent as the plunger is advanced forwardly into the barrel.

5. The medical device of claim 1 comprising a lock on the cartridge holder that substantially limits displacement of the needle after the needle is in the retracted position.

6. The medical device of claim 5 wherein the lock comprises a resilient flexible arm extending radially outwardly form the cartridge holder and configured to engage a window at the rearward end of the barrel when the needle is displaced to the retracted position.

7. The medical device of claim 1 wherein the cartridge comprises a piston having a threaded projection configured to mate with a threaded recess on the forward end of the plunger.

8. A medical device comprising:

a cartridge containing a medication;

a hollow barrel having a forward end adapted to receive the cartridge into the barrel;

a needle having a sharpened forward end and operable between an extended position, in which the sharpened forward end projects from the forward end of the barrel, and a retracted position, in which the sharpened forward end is enclosed within the barrel;

a plunger slidably disposed in the cartridge and operable to expel the medication from the cartridge;

a biasing element that biases the needle towards the retracted position; and

a needle retainer releasably engaging the barrel to maintain the needle in the projecting position against the force of the biasing element;

wherein axial pressure on the plunger displaces the plunger forwardly to expel medication from the cartridge and release the needle retainer from engagement with the barrel, after which the needle is automatically propelled from the extended position to the retracted position by releasing pressure on the plunger.

9. The medical device of claim 8 comprising a cartridge holder disposed around the needle and cartridge.

10. The medical device of claim 9 comprising an aperture in the barrel wall near the forward end of the barrel.

11. The medical device of claim 10, wherein the needle retainer comprises a resilient flexible arm extending radially outwardly from the cartridge holder and configured to releasably engage the aperture in the barrel wall when the needle is in the extended position.

12. The medical device of claim 11, wherein the plunger comprises a cylindrical sleeve having a forward end configured to displace the resilient flexible arm out of engagement with the aperture in the barrel wall as the plunger is advanced forwardly into the barrel.

13. The medical device of claim 8 comprising a lock on the cartridge holder that substantially limits displacement of the needle after the needle is in the retracted position.

14. The medical device of claim 13 wherein the lock comprises a resilient flexible arm extending radially outwardly form the cartridge holder and configured to engage a window at the rearward end of the barrel when the needle is displaced to the retracted position.

15. The medical device of claim 8 wherein the cartridge comprises a piston having a threaded projection configured to mate with a threaded recess on the forward end of the plunger.

16. A medical device for injecting medicinal fluid from a cartridge assembly comprising a cartridge having a quantity of medicinal fluid sealed by a septum, and a needle having a sharpened tip attached to the cartridge, comprising:

a hollow barrel;

a cartridge holder configured to receive the cartridge assembly;

a biasing element biasing the cartridge holder rearwardly;

a retainer releasably retaining the cartridge holder in a forward position against the bias of the biasing element so that the needle is exposed for use;

an advancer operable to drive the cartridge forward in the cartridge holder relative to the needle so that the needle pierces the septum;

a plunger operable to expel the medicinal fluid from the cartridge;

an actuator operable to release the retainer upon operation of the plunger;

wherein at the end of an injection the actuator operates to release the retainer so that the biasing element displaces the cartridge holder rearwardly along with the cartridge assembly.

17. The medical device of claim 16 comprises a lock operable to lock the cartridge holder in a retracted position.

18. The medical device of claim 16 wherein the advancer is rotatable relative to the cartridge holder to advance to cartridge.

19. The medical device of claim 16 comprising an elongated slot formed in the side of the cartridge holder to provide an access opening so that the cartridge assembly can be inserted into the cartridge holder while the plunger is attached to the cartridge holder.

20. The medical device of claim 16 wherein the retainer is a radially deformable latch.

21. The medical device of claim 16 wherein actuator is longitudinally displaceable relative to the plunger.

22. The medical device of claim 16 wherein the plunger has an elongated rod and a circumferential flange projecting radially outwardly to engage the actuator.

23. The medical device of claim 22 wherein the flange is operable to drive the actuator axially forwardly to actuate retraction of the cartridge holder.

24. The medical device of claim 16 wherein the cartridge assembly comprising means for releasably retaining the needle spaced apart from the cartridge.