Automatic syringe

• US 6,830,560 B1
• Filed: 07/17/2000
• Issued: 12/14/2004
• Est. Priority Date: 10/22/1997
• Status: Expired due to Term

• Current Assignee: Elan Pharma International Limited (Perrigo Company PLC)
• Original Assignee: Elan Corporation PLC (Perrigo Company PLC)
• Inventors: Lavi, Gilad, Tsals, Izrail, Gross, Joseph
• Primary Examiner(s): Hayes, Michael J.
• Application Number:
  US09/617,340
• Time in Patent Office: 1,611 Days
• Field of Search: 604/69, 604/93.01, 604/110, 604/140, 604/141, 604/143, 604/145, 604/148, 604/181, 604/187, 604/198
• US Class Current: 604/143
• CPC Class Codes: A61M 2005/2013 triggering of discharging means by contact of injector with patient body
• CPC Class Codes: A61M 2005/3247 Means to impede repositioning of protection sleeve from needle covering to needle uncovering position
• CPC Class Codes: A61M 2005/3267 Biased sleeves where the needle is uncovered by insertion of the needle into a patient's body
• CPC Class Codes: A61M 5/2046 Media being expelled from injector by gas generation, e.g. explosive charge
• 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
• CPC Class Codes: A61M 5/3257 Semi-automatic sleeve extension, i.e. in which triggering of the sleeve extension requires a deliberate action by the user, e.g. manual release of spring-biased extension means
• CPC Class Codes: A61M 5/3272 having projections following labyrinth paths
• CPC Class Codes: A61M 5/46 having means for controlling depth of insertion

Abstract

A syringe comprises a barrel containing an internal cylindrical body containing a liquid and communicating with a delivery needle. The needle is covered before use by a removable sheath, and after the sheath is removed, the needle is concealed by a displaceable sleeve. In use the sleeve is pressed against the skin by applying pressure while holding the barrel. The sleeve is thereby retracted into the barrel allowing the needle to penetrate the skin. The movement of the sleeve also activates a gas generator which expels the liquid from the needle. When delivery is complete and the syringe is taken from the skin, a coil spring moves the sleeve back to the starting position again concealing the needle. The coil spring is torsionally biased before use and causes a rotational movement of the sleeve relative to the barrel when the sleeve moves into and out of the barrel. This rotational movement engages a locking mechanism which prevents further movement of the sleeve and thereby permanently conceals the needle.

Claims

1. A syringe comprising:

a barrel having a liquid drug reservoir therein, the barrel having a first end and a second end, the drug reservoir having a piston slidingly engaged therein;

a needle assembly mounted at the first end of the barrel, the needle assembly holding a needle;

an energization source, located at the second end of the barrel;

a nozzle sleeve moveably mounted at the first end of the barrel from a first position where the tip of the needle is concealed by the nozzle sleeve to a second position where the tip of the needle is exposed, to an activation position, wherein when the nozzle sleeve is initially pressed against an injection site, the nozzle sleeve moves within the barrel from the first position to the second position, and the tip of the needle penetrates the injection site, and when the sleeve moves from the second position to the activation position, said energization source is activated to move said piston which drives a liquid from the reservoir.

2. The syringe of claim 1, wherein the energizing source is a gas generator.

3. The syringe of claim 2, wherein the gas generator includes a first chamber containing a citric acid solution and a second chamber containing a sodium bicarbonate solution.

4. The syringe of claim 1, further comprising a flexible retractor located between the needle assembly and the nozzle sleeve, the flexible retractor biasing the nozzle sleeve to the first position.

5. The syringe of claim 4, wherein the retractor is a helical compression spring.

6. The syringe of claim 1, wherein the nozzle sleeve moves axially and rotationally relative to the barrel between the first position and second position.

7. The syringe of claim 6, wherein the nozzle sleeve further includes a channel extending along an exterior wall of the sleeve, and the barrel further includes a peg extending inward from an inner wall of the barrel, the channel receiving the peg to cause relative rotational movement during relative axial movement between the barrel and sleeve, and having a shape that maintains the sleeve in a locked position to prevent further exposure of the needle after extraction of the fluid.