Low dead space, interchangeable needle syringe

• US 5,782,803 A
• Filed: 11/26/1996
• Issued: 07/21/1998
• Est. Priority Date: 11/26/1996
• Status: Expired due to Term

• Current Assignee: Saf-T-Med, Inc. (Becton, Dickinson & Co)
• Original Assignee: Jentzen S. William
• Inventors: Jentzen, S. William
• Primary Examiner(s): YASKO JR, JOHN D
• Application Number:
  US08/756,241
• Time in Patent Office: 602 Days
• Field of Search: 604/110, 604/187, 604/218, 604/222, 604/221, 604/220
• US Class Current: 604/110
• CPC Class Codes: A61M 2005/31516 reducing dead-space in the syringe barrel after delivery
• 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 5/32 Needles; Details of needles pertaining to their connection with syringe or hub infusion needles A61M5/158; Accessories for bringing the needle into, or holding the needle on, the body A61M5/42, A61M5/46 take precedence; guide needles for catheters A61M25/065; Devices for protection of needles apparatus specially adapted for cleaning or sterilising needles A61M5/001
• CPC Class Codes: A61M 5/347 rotatable, e.g. bayonet or screw A61M5/344 takes precedence

Abstract

A non-reusable syringe is provided which has an interchangeable needle, and, further, which has very low residual medication in the syringe after use. Devices for achieving the interchangeable needles while maintaining low residual medication are disclosed.

Claims

1. A low dead space safety syringe, comprising:

(a) a cylindrical barrel including first and second ends, and comprising a first internal diameter wall of a given diameter and a second internal wall having an internal diameter smaller than the diameter of the first internal diameter wall, said second internal diameter wall having an end protruding distally away from the distal end of the first internal diameter wall and terminating at the second barrel end;

(b) a nozzle section on said barrel and including nozzle dead space;

(c) a chamber for receipt of medicinal fluid within said barrel and said nozzle section and between said first and second barrel ends;

(d) a plunger extendable into said barrel through the first end of said barrel, said plunger having distal and proximal ends, said plunger being selectively moveable from an expanded position to an expended position;

(e) a hollow needle assembly selectively securable to the barrel and around the nozzle section; and

(f) dead space sealing means including an elastomeric sealing member engaged with the plunger immediate the distal end of the plunger for slidable sealing contact with at least one of the first and second internal diameter walls of said barrel, said sealing means further including an elongated nose tip portion slidable along and extending distally through the second internal wall of the barrel, whereby, when said plunger is moved to said expended position said sealing means extends through said barrel and said nozzle section and to the second barrel end to eject the medicinal fluid within said nozzle dead space out of said chamber and said nozzle section.

2. The syringe of claim 1 further comprising means for selectively securing a hollow needle assembly to the barrel immediate and internal of the second end of said barrel.

3. The syringe of claim 1 wherein at least one fluid flow channel is defined on the exterior of the elongated nose tip portion of the dead space sealing means for transmission of fluid out of the chamber and the nozzle section dead space when the plunger is moved from the expanded position to the expended position.

4. The syringe of claim 1 wherein fluid flow channel means are defined on the exterior of the elongated nose tip portion for transmission of fluid out of the chamber and the nozzle section dead space when the plunger is moved between the expanded position and the expended position, said fluid flow channel means including a series of radially spaced horizontal and intersecting vertical channel members.