Positive displacement flush syringe

• US 20060247582A1
• Filed: 01/07/2005
• Published: 11/02/2006
• Est. Priority Date: 01/07/2005
• Status: Active Grant

• Current Assignee: Becton, Dickinson & Co
• Original Assignee: Becton, Dickinson & Co
• Inventors: Alheidt, Thomas, Kosinski, Anthony J.
• Granted Patent: US 9,522,237 B2
• Time in Patent Office: Days
• US Class Current: 604/228
• CPC Class Codes: A61M 2005/1403 Flushing or purging
• CPC Class Codes: A61M 2005/3123 having air entrapping or venting means, e.g. purging channels in pistons
• CPC Class Codes: A61M 2005/31508 provided on the piston-rod
• CPC Class Codes: A61M 25/00 Catheters; Hollow probes dilators A61M29/00; peritoneal catheters A61M1/285; tracheal tubes A61M16/04; for drainage A61M27/00; for uterus, vagina or rectum A61M31/00 ; for measuring or testing A61B; materials for catheters A61L29/00
• CPC Class Codes: A61M 25/10182 Injector syringes
• CPC Class Codes: A61M 5/3134 characterised by constructional features of the distal end, i.e. end closest to the tip of the needle cannula
• CPC Class Codes: A61M 5/31505 Integral with the syringe barrel, i.e. connected to the barrel so as to make up a single complete piece or unit
• CPC Class Codes: A61M 5/31511 Piston or piston-rod constructions, e.g. connection of piston with piston-rod A61M5/5066 takes precedence
• CPC Class Codes: A61M 5/31515 Connection of piston with piston rod
• CPC Class Codes: A61M 5/31578 based on axial translation, i.e. components directly operatively associated and axially moved with plunger rod
• CPC Class Codes: A61M 5/3293 characterised by features of the needle hub
• CPC Class Codes: A61M 5/502 for blocking the piston

Abstract

A flush syringe assembly comprises a barrel including a cylindrical side wall having an inside surface defining a chamber for retaining fluid, an open proximal end and a distal end having a passageway therethrough in fluid communication with the chamber. A plunger including an elongate body portion having a stopper at its distal end is provided. The stopper is slidably positioned in fluid-tight engagement with the inside surface of the barrel for driving fluid out of the chamber through the passageway. The stopper includes a distal portion and a proximal portion separated by a spring element and configured to compress when fluid is being driven through the passageway by motion of the plunger and to continue to drive fluid through the passageway after motion of the plunger has stopped.

Claims

1. A flush syringe assembly comprising:

a barrel including a cylindrical side wall having an inside surface defining a chamber for retaining fluid, an open proximal end and a distal end including a distal wall with a tip extending distally therefrom having a passageway therethrough in fluid communication with said chamber;

a plunger including an elongate body portion having a proximal end, and a distal end, a stopper slidably positioned in fluid-tight engagement with said inside surface of said barrel for driving fluid out of said chamber by movement of said stopper relative to said barrel, said elongate body portion extending outwardly from said open proximal end of said barrel,

a discontinuity on said plunger for engaging said barrel for stopping the distal motion of said plunger before said stopper fully delivers all liquid from said chamber,

said stopper including a proximal stopper portion connected to said distal end of said plunger and a distal stopper portion separated from said proximal stopper portion by spring means for moving said distal stopper portion in a distal direction to drive more liquid out of said chamber after said discontinuity on said plunger engages said barrel to stop distal motion of said plunger.

2. The syringe assembly of claim 1 wherein said spring means includes a spring element connecting said distal stopper portion to said proximal stopper portion.

3. The syringe assembly of claim 2 wherein said spring element includes a coil spring.

4. The syringe assembly of claim 2 wherein said spring element includes an annular cantilevered element.

5. The syringe assembly of claim 1 wherein said spring means includes an air space between said distal stopper portion and said proximal stopper portion.

6. The syringe assembly of claim 1 wherein said distal stopper portion is configured to engage said inside surface of said barrel so that less force is required to move the distal stopper portion along said chamber than said proximal stopper portion.

7. The syringe assembly of claim 1 wherein said distal stopper portion has at least one circumferential rib engaging said inside surface of said barrel and said proximal stopper portion has at least two circumferential ribs engaging said inside surface of said barrel.

8. The syringe assembly of claim 1 wherein said discontinuity is an outwardly directed projection on said elongate body portion.

9. The syringe assembly of claim 1 wherein said discontinuity on said plunger is configured to engage a discontinuity on said barrel to retain the plunger and prevent further distal and proximal motion of said plunger with respect to said barrel during normal use of said syringe assembly.

10. The syringe assembly of claim 1 further including means for allowing air trapped between said proximal stopper portion and said distal stopper portion to escape toward said open proximal end of said barrel.

11. The syringe assembly of claim 10 wherein said means for allowing trapped air to escape includes an aperture in said plunger.

12. The syringe assembly of claim 10 wherein said means for allowing trapped air to escape includes a less than air-tight fit between said plunger and said proximal stopper portion.

13. The syringe assembly of claim 10 wherein said means for allowing trapped air to escape includes at least one discontinuity in an outside diameter of said proximal stopper portion.

14. The syringe assembly of claim 1 wherein deflection of said spring means occurs when said liquid pressure is about 5 mm Hg. (0.1 psi) or more.

15. The syringe assembly of claim 1 including flush solution in said chamber.

16. The syringe assembly of claim 15 wherein said flush solution is selected from the group consisting of saline flush solution and heparin lock flush solution.

17. The syringe assembly of claim 15 further including a tip cap releasably connected to said tip of said syringe barrel for sealing said passageway.

18. The syringe assembly of claim 1 wherein said stopper is made of material selected from the list consisting of thermoplastic elastomers, natural rubber, synthetic rubber, thermoplastic materials and combinations thereof.

19. The syringe assembly of claim 1 further comprising a needle assembly including a cannula having a proximal end, a distal end and a lumen therethrough, and a hub having an open proximal end containing a cavity and a distal end attached to said proximal end of said cannula so that said lumen is in fluid communication with said cavity, said needle assembly being removably attached to said tip of said barrel through engagement of said tip to said cavity so that said lumen is in fluid communication with said chamber.