MEDICAL DEVICE INCLUDING AN AIR EVACUATION SYSTEM

• US 20110224611A1
• Filed: 04/26/2010
• Published: 09/15/2011
• Est. Priority Date: 03/15/2010
• Status: Active Grant

• Current Assignee: Becton, Dickinson & Co
• Original Assignee: Becton, Dickinson & Co
• Inventors: Lum, Chee Leong, Soltz, Michael
• Granted Patent: US 8,172,794 B2
• Time in Patent Office: Days
• US Class Current: 604/125
• CPC Class Codes: A61B 5/15003 for venous or arterial blood
• CPC Class Codes: A61B 5/150213 Venting means
• CPC Class Codes: A61B 5/150236 Pistons, i.e. cylindrical bodies that sit inside the syringe barrel, typically with an air tight seal, and slide in the barrel to create a vacuum or to expel blood
• CPC Class Codes: A61B 5/153 Devices specially adapted for taking samples of venous or arterial blood, e.g. with syringes
• CPC Class Codes: A61M 2005/3112 Incorporating self-aspirating means, e.g. to provide flashback
• CPC Class Codes: A61M 2005/3123 having air entrapping or venting means, e.g. purging channels in pistons
• CPC Class Codes: A61M 2005/31516 reducing dead-space in the syringe barrel after delivery
• CPC Class Codes: A61M 5/1782 Devices aiding filling of syringes in situ combination of a vial and a syringe for transferring or mixing their contents A61J1/2096, filling of medical containers in general B65B3/003
• CPC Class Codes: A61M 5/3145 Filters incorporated in syringes
• 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 5/31513 Piston constructions to improve sealing or sliding
• CPC Class Codes: A61M 5/36 with means for eliminating or preventing injection or infusion of air into body dialysis systems, blood oxygenators A61M1/14; haemofiltration equipment A61M1/34; automatic tube cut-off A61M39/281

Abstract

Medical device assemblies capable of aspirating liquid into a syringe barrel or other medical devices while evacuating any air from the syringe are described. An exemplary medical device includes a syringe barrel, plunger rod and stopper assembly having an air permeable and liquid impermeable porous portion and structure for forming a vacuum within either the stopper or the plunger rod. Described is a medical device including a syringe barrel, plunger rod and stopper assembly having an air permeable and liquid impermeable porous portion and structure for forming a vacuum within chamber between the stopper and plunger rod wherein the plunger rod includes a sealing edge and is moveable relative to the stopper. Exemplary medical devices may include a vent for allowing air that permeates through the porous portion to escape to atmosphere. Methods for aspirating a syringe barrel with a liquid are also provided.

Claims

1. A medical device comprising:

a syringe barrel including a 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 an open passageway in fluid communication with said chamber;

a plunger rod comprising a proximal end, a distal end and body extending from the proximal end to the distal end, the plunger rod disposed within the chamber and moveable in the proximal and distal direction within the chamber;

a stopper assembly disposed within the chamber and moveable in the proximal and distal direction within the chamber, the stopper assembly forming a fluid-tight seal with the inside surface of the syringe barrel, the stopper including a distal face, a proximal end and a body extending from the distal face to the proximal end defining a stopper cavity;

a stopper hub defining a hub cavity and including an open distal end and an open proximal end in fluid communication with the stopper cavity, the distal end of the plunger rod forming a fluid tight seal with the stopper hub and being slidably engaged with the stopper hub to move in a proximal direction relative within the hub cavity to form a vacuum within the hub cavity; and

a porous portion associated with the stopper to permit air to flow into the stopper cavity and to prevent liquid from entering the stopper cavity, the plunger rod and stopper configured to create a pressure differential between the stopper cavity and a portion of the chamber extending from the distal wall and the distal face of the stopper assembly.

2. The medical device of claim 1, further comprising a vent associated with the stopper to release the air from the stopper cavity.

3. The medical device of claim 1, wherein the porous portion comprises a selective barrier that defines a liquid penetration pressure and an air penetration pressure that is less than the liquid penetration pressure.

4. The medical device of claim 3, wherein the porous portion comprises one of a hydrophilic filter, a hydrophobic filter, a swellable polymer or a combination thereof.

5. The medical device of claim 3, wherein the distal face of the stopper comprises an opening in fluid communication with the stopper cavity, the proximal end of the stopper assembly includes an opening in fluid communication with the stopper cavity.

6. The medical device of claim 5, wherein the open proximal end of the stopper hub includes a peripheral wall and the distal end of plunger rod comprises a disc member forming a fluid-tight seal with the peripheral wall.

7. The medical device of claim 6, wherein the peripheral wall comprises a means for preventing distal movement of the plunger rod relative to the stopper hub, after an initial proximal movement of the plunger rod relative to the stopper hub.

8. The medical device of claim 7, wherein, upon application of an initial force on the plunger rod in a proximal direction expands the hub cavity and creates a vacuum within the hub cavity that draws air from the chamber into the stopper cavity through the porous portion disposed between the distal face and stopper cavity.

9. The medical device of claim 8, wherein application of a continuous force on the plunger rod in a proximal direction causes the plunger rod and stopper to move in a proximal direction and draws liquid into the chamber.

10. The medical device of claim 9, wherein application of a force on the plunger rod in the distal direction causes the plunger rod and stopper to move in the distal direction and the stopper hub to remain expanded.

11. The medical device of claim 6, wherein the peripheral wall of the stopper hub includes a vent in fluid communication with the chamber and the exterior of the medical device.

12. A medical device comprising:

a syringe barrel including a 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 an open passageway in fluid communication with said chamber;

a plunger rod disposed within the chamber and moveable in the proximal and distal direction within the chamber, the plunger comprising a proximal end, a distal end including a sealing edge for forming a fluid-tight seal with the inside surface of the syringe barrel and a body extending from the proximal end to the distal end, the body including an inside surface defining a plunger rod cavity;

a slidable portion disposed within the plunger rod cavity and moveable in the proximal and distal direction within the plunger rod cavity, the slidable portion forming a fluid-tight seal with the inside surface of the plunger rod cavity; and

a porous portion associated with the plunger rod to permit air to flow into the plunger cavity and to prevent liquid from entering the plunger rod cavity, the plunger rod and slidable portion configured to create a pressure differential between the plunger rod cavity and a portion of the chamber extending from the distal wall and the sealing edge of the plunger rod.

13. The medical device of claim 12, further comprising a vent associated with the stopper to release the air from the stopper cavity.

14. The medical device of claim 12, wherein the porous portion comprises a selective barrier that defines a liquid penetration pressure and an air penetration pressure that is less than the liquid penetration pressure.

15. The medical device of claim 12, wherein the porous portion comprises one of a hydrophilic filter, a hydrophobic filter, a swellable polymer or a combination thereof.

16. The medical device of claim 12, wherein the distal end of the plunger rod includes an opening in fluid communication with the plunger rod cavity.

17. The medical device of claim 16, wherein the slidable portion comprises a retainer for restricting movement of the slidable portion within the plunger rod cavity after an initial movement of the slidable portion in a proximal direction relative to the plunger rod.

18. The medical device of claim 16, wherein upon the initial movement of the slidable portion in a proximal direction, a vacuum is created within the plunger rod cavity drawing air from the chamber into the plunger rod cavity through the porous portion.

19. The medical device of claim 18, wherein upon application of a force on the plunger rod in a proximal direction draws liquid into the chamber and application of a force on the plunger rod in the distal direction expels the liquid drawn into the chamber.

20. A method for filling a syringe barrel with liquid, comprising:

providing a syringe barrel having a chamber having an air source, a needle cannula having an opening, a plunger rod assembly including a sealing means for forming a fluid tight seal with the syringe barrel and a cavity, and means for evacuating an air from the chamber into the plunger rod assembly;

submerging the opening of the needle cannula in a liquid;

expanding the cavity within the plunger rod assembly;

drawing the air source and the liquid into the chamber; and

evacuating the air source from the chamber into the plunger rod assembly.

21. The method of claim 20, wherein submerging the opening of the needle cannula occurs after providing a vacuum within the plunger rod assembly.

22. The method of claim 21 further comprising venting the air from the plunger rod assembly.