Arterial blood gas syringe

• US 4,821,738 A
• Filed: 11/19/1987
• Issued: 04/18/1989
• Est. Priority Date: 11/19/1987
• Status: Expired due to Term

• Current Assignee: Vital Signs Incorporated (Becton Dickinson & Co)
• Original Assignee: Vital Signs Colorado, Inc. (Becton Dickinson & Co)
• Inventors: Iwasaki, Dean H., Iliff, Michael D.
• Primary Examiner(s): Yasko, John D.
• Application Number:
  US07/122,892
• Time in Patent Office: 516 Days
• Field of Search: 604/190, 604/187, 604/222, 128/765, 128/766, 128/767
• US Class Current: 600/578
• 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 5/150244 Rods for actuating or driving the piston, i.e. the cylindrical body that sits inside the syringe barrel, typically with an air tight seal, and slides 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 2005/3123 having air entrapping or venting means, e.g. purging channels in pistons
• CPC Class Codes: A61M 5/385 using hydrophobic filters

Abstract

An arterial blood gas syringe is disclosed for obtaining an arterial blood sample. The syringe is characterized by a sealing plug having channels formed in an upper surface thereof for use in removing air as arterial blood is received into the syringe. Each of the channels extends in a generally radial direction and the channels converge near the center of the sealing plug. A filter element is contained in the center of the sealing plug for permitting the passage of air directed thereto using the channels. The filter element permits the passage of the air but prevents passage of the blood.

Claims

1. A syringe, comprising:

a syringe barrel including a tapered end and an open and and having an inner wall surface;

a plunger rod having a tip;

a sealing plug connected to said plunger rod tip for preventing the flow of blood past said open end of said syringe barrel, said sealing plug having an upper surface and a hollow interior with an inner hollow section being defined in said hollow interior, said upper surface of said sealing plug having a plurality of channels extending laterally across said upper surface, said channels being of a size wherein blood tends to fill a blood receiving space defined between said upper surface and said tapered end of said syringe barrel before the blood moves along said channels; and

filter means held in said inner hollow section for use in permitting the passage of air from said blood receiving space while preventing the passage of blood from said blood receiving space, said channels providing a passageway for air from said blood receiving space to said filter means.

2. A syringe, as claimed in claim 1, wherein:

said upper surface of said sealing plug includes an sealing rim positioned adjacent to said inner wall surface of said syringe barrel to contain blood in said blood receiving space.

3. A syringe, as claimed in claim 2, wherein:

one end of each of said channels is located at said sealing rim for use in ensuring that no unwanted, trapped air remains in said blood receiving space.

4. A syringe, as claimed in claim 2, wherein:

said upper surface of said sealing plug is conically shaped for biasing air to said channels.

5. A syringe, as claimed in claim 2, wherein:

each of said channels extends substantially radially from said annular ring of said sealing plug towards a center portion of said upper surface of said sealing plug.

6. A syringe, as claimed in claim 5, wherein:

the width of at least one of said channels is greater adjacent said center portion of said sealing plug than said width thereof adjacent said sealing rim of said sealing plug.

7. A syringe, as claimed in claim 2, wherein:

each of said channels has a lower surface with a slope to insure that no unwanted, trapped air remains in said channels.

8. A syringe, as claimed in claim 1, wherein:

said upper surface of said sealing plug has a center plug element at which each of said channels terminates, said center plug element being located substantially at a midportion of said filter means.

9. a syringe, as claimed in claim 1, wherein:

the length of said inner hollow section is greater than the diameter of said inner hollow section.

10. A syringe, as claimed in claim 1, wherein:

said filter means is generally cylindrical-shaped having a length greater than the diameter thereof.