Syringe with means for allowing passage of air while preventing the passage of blood to obtain a gas-free blood sample

• US 4,572,210 A
• Filed: 03/18/1982
• Issued: 02/25/1986
• Est. Priority Date: 07/01/1981
• Status: Expired due to Term

• Current Assignee: Vital Signs Incorporated (Becton, Dickinson & Co)
• Original Assignee: Vital Signs Colorado, Inc. (Becton, Dickinson & Co)
• Inventors: McKinnon, Robert J.
• Primary Examiner(s): YASKO JR, JOHN D
• Application Number:
  US06/359,292
• Time in Patent Office: 1,440 Days
• Field of Search: 128/762-766, 128/218 P, 128/218 PA, 128/218 R, 128/760, 210/323 R, 210/474, 210/477, 210/482, 604/190, 604/187
• 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 5/150259 Improved gripping, e.g. with high friction pattern or projections on the housing surface or an ergonometric shape
• CPC Class Codes: A61B 5/150389 Hollow piercing elements, e.g. canulas, needles, for piercing the skin
• CPC Class Codes: A61B 5/150503 Single-ended needles hollow piercing element tip design A61B5/150396, needle sets for catheters A61M25/06, needles for bringing media into the body A61M5/32
• 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 2005/3128 Incorporating one-way valves, e.g. pressure-relief or non-return valves
• 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

Abstract

A syringe device for obtaining a gas-free blood sample has a tubular body connected to an hypodermic needle. The tubular body receives a resilient sealing member operatively connected to a plunger rod. The sealing member and plunger rod have a vent formed longitudinally therealong to provide a passageway for the purge of air as an interior chamber of the tubular body is filled with blood. The passageway is covered with an hydrophobic filter allowing the passage of air until such time as blood completely contacts the filter, at which time blood cannot cross the hydrophobic filter. The interior chamber containing the blood sample is then purged of all air.

Claims

1. A syringe device for obtaining blood samples comprising in combination:

a tubular body having an interior surface defining an elongated interior chamber, said tubular body having an opening at one end thereof and an end wall at another end thereof, said end wall having an extension protruding therefrom outward of said body, said extension having a bore therethrough, said extension defining means for connecting an hypodermic needle thereto to allow blood to flow from the needle through the bore and into the interior chamber;

plunger means including an elongated plunger rod having a passageway therethrough and a sealing member having a sealing member passageway therethrough in air flow communication with said plunger rod passageway, said plunger rod being operatively connected to said sealing member, said sealing member having a plurality of longitudinal grooves spaced around a circumference thereof, said grooves contacting said interior surface; and

an hydrophobic membrane connected to said plunger means for allowing the flow of air through said plunger rod and sealing member passageways, when said hydrophobic membrane is dry, said hydrophobic filter means further preventing the passage of air and blood through said plunger rod and sealing member passageways upon said hydrophobic membrane being contaced by said blood at any pressure less than one hundred eighty millimeters Hg.

2. A syringe device for obtaining a blood sample from a patient under the force of arterial blood pressure, comprising,

a tubular body having an interior chamber, an end wall at one end of the interior chamber, said end wall being provided with means for connecting a needle to the tubular body and an inlet passage means for communicating blood from the connected needle into said interior chamber;

plunger means located in said interior chamber, said plunger means including a sealing member which is axially slidable within said chamber, said plunger means being axially spaced from the end wall to provide a blood-receiving space of adjustable volume located between the end wall and the sealing member, said blood-receiving space being radially coextensive with the interior chamber, said plunger means having at least one venting passageway communicating between the blood-receiving space and the ambient environment exterior of the device, said venting passageway being operable to permit gas to flow to the ambient atmosphere from the blood-receiving space;

passageway sealing means jointed to the plunger means and positioned in the venting passageway, said passageway sealing means when dry being operable to allow gas to flow through said venting passageway, said passageway sealing means when wetted by blood being operable to prevent the flow of blood through said passageway;

said venting passageway being unobstructed between the sealing means and the ambient environment exterior of the device.

3. A syringe device according to claim 2 wherein the venting passageway includes a plurality of spaced grooves formed in the circumference of said sealing member.

4. A syringe device according to claim 2 wherein the passageway sealing means is operable when wetted by blood to prevent the flow of blood through the passageway at any pressure less than one hundred eighty millimeters Hg.

5. A syringe device according to claim 2 wherein said plunger means includes a rod which projects outwardly from said interior chamber, said venting passageway including a plurality of spaced grooves formed in the circumference of said sealing member, said passageway sealing means being operable when wetted by blood to permit the flow of blood through the passageway at any pressure less than one hundred eighty millimeters Hg.

6. A syringe device according to claim 2 wherein said plunger means includes a rod which projects outwardly from said interior chamber.

7. A syringe device according to claim 6 wherein the venting passageway extends longitudinally through the sealing member and the plunger rod.

8. A syringe device for obtaining a blood sample from a patient under the force of arterial blood pressure, comprising,

a tubular body having an interior chamber, an end wall at one end of the interior chamber, said end wall being provided with means for connecting a needle to the tubular body and an inlet passage means for communicating blood from the connected needle into said interior chamber;

plunger means located in said interior chamber, said plunger means including a sealing member which is axially slidable within said chamber to provide a blood-receiving space of adjustable volume located between the end wall and the sealing member, said plunger means having at least one venting passageway communicating between the blood-receiving space and the ambient environment exterior of the device, said venting passageway being operable to permit gas to flow to the ambient atmosphere from the blood-receiving space; and

passageway sealing means mounted on the plunger means and positioned in the venting passageway, said passageway sealing means being a hydrophobic filter which, when dry, is operable to allow gas to flow through said venting passageway, said hydrophobic filter when wetted by blood being operable to prevent the flow of blood through said passageway.

9. A syringe device according to claim 8 wherein the venting passageway includes a plurality of spaced grooves formed in the circumference of said sealing member.

10. A syringe device according to claim 8 wherein the passageway sealing means is operable when wetted by blood to prevent the flow of blood through the passageway at any pressure less than one hundred eighty millimeters Hg.

11. A syringe device according to claim 8 wherein said plunger means includes a rod which projects outwardly from said interior chamber, said venting passageway including a plurality of spaced grooves formed in the circumference of said sealing member, said passageway sealing means being operable when wetted by blood to permit the flow of blood through the passageway at any pressure less then one hundred eighty millimeters Hg.

12. A syringe device according to claim 8 wherein said plunger means includes a rod which projects outwardly from said interior chamber.

13. A syringe device according to claim 12 wherein the venting passageway extends longitudinally through the sealing member and the plunger rod.

23. A syringe device according to claim 10 wherein said plunger means includes a rod which projects outwardly from said interior chamber, said venting passageway including a plurality of spaced grooves formed in the circumference of said sealing member, said passageway sealing means being operable when wetted by blood to permit the flow of blood through the passageway at any pressure less than one hundred eighty millimeters Hg.

14. A syringe device for obtaining a blood sample from a patient under the force of arterial blood pressure, comprising,

a tubular body having an interior chamber, an end wall at one end of the interior chamber, said end wall being provided with means for connecting a needle to the tubular body and an inlet passage means for communicating blood from the connected needle into said interior chamber;

plunger means located in said interior chamber, said plunger means including a sealing member which is axially slidable within said chamber, said plunger means being axially spaced from the end wall to provide a blood-receiving space of adjustable volume located between the end wall and the sealing member, said blood-receiving space being radially coextensive with the interior chamber, said plunger means having at least one venting passageway communicating between the blood-receiving space and the ambient environment exterior of the device, said venting passageway being operable to permit gas to flow to the ambient atmosphere from the blood-receiving space; and

passageway sealing means mounted on the plunger means and positioned in the venting passageway, said passageway sealing means being a hydrophobic filter which, when dry, is operable to allow gas to flow through said venting passageway, said hydrophobic filter when wetted by blood being operable to prevent the flow of blood through said passageway.

15. A syringe device according to claim 14 wherein the venting passageway includes a plurality of spaced grooves formed in the circumference of said sealing member.

16. A syringe device according to claim 14 wherein the passageway sealing means is operable when wetted by blood to prevent the flow of blood through the passageway at any pressure less than one hundred eighty millimeters Hg.

17. A syringe device according to claim 14 wherein said plunger means includes a rod which projects outwardly from said interior chamber, said venting passageway including a plurality of spaced grooves formed in the circumference of said sealing member, said passageway sealing means being operable when wetted by blood to permit the flow of blood through the passageway at any pressure less than one hundred eighty millimeters Hg.

18. A syringe device according to claim 14 wherein said plunger means includes a rod which projects outwardly from said interior chamber.

19. A syringe device according to claim 18 wherein the venting passageway extends longitudinally through the sealing member and the plunger rod.

20. A syringe device for obtaining a blood sample from a patient under the force of arterial blood pressure, comprising,

a tubular body having an interior chamber, an end wall at one end of the interior chamber, said end wall being provided with means for connecting a needle to the tubular body and an inlet passage means for communicating blood from the connected needle into said interior chamber;

plunger means located in said interior chamber, said plunger means including a sealing member which is axially slidable within said chamber to provide a blood-receiving space of adjustable volume located between the end wall and the sealing member, said plunger means having at least one venting passageway communicating between the blood-receiving space and the ambient environment exterior of the device, said venting passageway being operable to permit gas to flow to the ambient atmosphere from the blood-receiving space; and

passageway sealing means mounted on the plunger means and positioned in the venting passageway, said passageway sealing means when dry being operable to allow gas to flow through said venting passageway, said passageway sealing means when wetted by blood being operable to prevent the flow of blood through said passageway,

said device being devoid of any means for interrupting the flow of gas between the passageway sealing means and the ambient environment exterior of the device.

21. A syringe device according to claim 20 wherein the venting passageway includes a plurality of spaced grooves formed in the circumference of said sealing member.

22. A syringe device according to claim 20 wherein the passageway sealing means is operable when wetted by blood to prevent the flow of blood through the passageway at any pressure less than one hundred eighty millimeters Hg.

24. A syringe device according to claim 20 wherein said plunger means includes a rod which projects outwardly from said interior chamber.

25. A syringe device according to claim 24 wherein the venting passageway extends longitudinally through the sealing member and the plunger rod.

26. A method of obtaining a blood sample from a patient with a syringe, said syringe having a tubular body with an interior chamber, a needle communicating with one end of said chamber, a sealing member which is axially movable within the chamber, a plunger rod which is connected to the sealing member and extends outwardly from the tubular body, a venting passageway which extends through the sealing member, and sealing means in the venting passageway which when dry allows blood to flow through the passageway and when wet prevents the flow of blood through the passageway, said method comprising the following steps:

(a) moving said plunger rod to slide said sealing member axially in said interior chamber to a position where gas of a given volume is located between the passageway sealing means and said one end of the chamber,

(b) inserting the needle into the artery of a patient,

(c) flowing blood through the needle and into the chamber under arterial blood pressure,

(d) venting gas from the chamber through the passageway sealing means while blood is flowing into the chamber,

(e) contacting said passageway sealing means with blood when the chamber has received said given volume of blood, thereby sealing said venting passageway,

(f) removing the needle from the patient,

(g) said sealing member being maintained at a stationary position in the chamber during steps (b), (c), (d), (e) and (f).

27. A fluid collection syringe, comprising, in combination:

an elongated hollow housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a hollow needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly including a plunger slidably mounted within said bore, said plunger assembly forming at least a partial sliding liquid and gas seal with said sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a fluid receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising a bypass element disposed between said plunger and the inside surface of said sidewall for establishing a pressure relief passageway between said chamber and the atmosphere for air trapped in said chamber, said bypass element when dry allowing air to pass through said passageway to enable fluid entering said chamber through said needle member to displace air from said chamber through said passageway, and when wet blocking fluid from passing through said passageway, and remaining at least partially exposed to the interior of said chamber when said chamber is filled with fluid whereby said bypass element is wetted to prevent fluid from leaking from said chamber through said passageway.

28. A fluid sample collection syringe as defined in claim 27 wherein said bypass element is formed of a porous material, which allows the passage of air when dry and blocks the passage of said fluid when wetted by said fluid.

29. A fluid sample collection syringe as defined in claim 27 wherein said plunger includes at least one annular rim portion slidably engaged in gas-sealing relationship to said inside surface of said sidewall and said bypass element is disposed between said rim portion and said sidewall.

30. A syringe as defined in claim 28 wherein said plunger includes at least one annular rim portion slidably engaged in gas-sealing relationship to the inside surface of said sidewall, and said bypass element comprises an annular collar disposed over said rim portion between said rim portion and the interior surface of said sidewall.

31. A syringe for collecting a blood sample from an artery, said syringe comprising, in combination:

an elongated generally cylindrical housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a hollow needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly including a plunger slidably mounted within said bore, said plunger assembly forming at least a partial sliding liquid and air seal with said sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a blood receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising a bypass element disposed between said plunger and the inside surface of said sidewall for establishing a pressure relief passageway between said chamber and said open end of said bore for air trapped in said chamber, said bypass element when dry allowing the free passage of air from said chamber through said passageway to enable blood entering said chamber under arterial pressure through said needle member to displace air from said chamber, and when wetted by blood blocking the passage of blood through said passageway, and remaining at least partially exposed to the interior of said chamber when said chamber is filled with blood whereby said bypass element is wetted to preclude blood leaking from said chamber through said passageway.

32. A blood sample collection syringe as defined in claim 31 wherein said plunger includes at least one annular rim portion slidably engaged in air-sealed relationship to said inside surface of said sidewall, and said bypass element is disposed between said rim portion and said sidewall.

33. A syringe as defined in claim 31 wherein said plunger includes at least one annular rim portion slidably engaged in air sealing relationship to the inside surface of said sidewall, and said bypass element comprises an annular collar disposed over said rim portion between said rim portion and the interior surface of said sidewall.

34. A blood sample collection syringe as defined in claim 31 wherein said bypass element is formed of a porous material, which allows the passage of gas when dry and blocks the passage of blood when wetted by said blood.

35. A fluid collection syringe comprising, in combination:

an elongated hollow housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly slidably mounted within said bore said plunger assembly including a plunger having a rim portion forming at least a partial sliding liquid and gas seal with said sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a fluid receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising an annular bypass element disposed over said rim portion between said rim portion and the inside surface of said sidewall for establishing a pressure relief passageway between said chamber and the atmosphere for gas trapped in said chamber, said bypass element when dry allowing gas to pass from said chamber to allow fluid to enter said chamber through said needle member, and when wet blocking gas from passing from said chamber, and being at least partially exposed to the interior of said chamber whereby when said chamber is filled with fluid said bypass element is wetted to prevent fluid from leaking from the chamber.

36. A syringe for collecting a blood sample from an artery, said syringe comprising, in combination:

an elongated generally cylindrical housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly slidably mounted within said bore, said plunger assembly including a plunger having a rim portion forming at least a partial sliding liquid and air seal with side sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a fluid receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising an annular bypass element disposed over said rim portion between said rim portion and the inside surface of said sidewall for establishing a pressure relief passageway between said chamber and said open end of said bore for air trapped in said chamber, said bypass element when dry allowing the free passage of air from said chamber to allow blood to enter said chamber under arterial pressure through said needle assembly and when wetted by said blood blocking the passage of air and blood and being at least partially exposed to the interior of said chamber whereby when said chamber is filled with blood said bypass element is wetted to preclude leaking of blood from said chamber.

37. A fluid collection syringe comprising in combination:

an elongated hollow housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a hollow needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly including a plunger slidably mounted within said bore, said plunger assembly forming at least a partial sliding liquid and gas seal with said sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a fluid receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising a bypass element disposed between said plunger and the inside surface of said sidewall for establishing a pressure relief passageway between said chamber and the atmosphere for exhausting air from said chamber upon fluid entering said chamber through said needle member, said pressure relief passageway automatically closing to the passage of fluid without said movement of said plunger upon the chamber becoming filled with fluid.

38. A syringe for collecting a blood sample from an artery, said syringe comprising, in combination:

an elongated generally cylindrical housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a hollow needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly including a plunger slidably mounted within said bore, said plunger assembly forming at least a partial sliding liquid and air seal with said sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a blood receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising a bypass element disposed between said plunger and the inside surface of said sidewall for establishing a pressure relief passageway between said chamber and the atmosphere for exhausting air from said chamber upon blood entering said chamber through said needle member, said pressure relief passageway automatically closing to passage of blood without movement of said plunger upon said chamber becoming filled with blood.

39. A fluid collection syringe, comprising, in combination:

an elongated hollow housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a hollow needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly including a plunger slidably mounted within said bore, said plunger assembly forming at least a partial sliding liquid and gas seal with said sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a fluid receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising a bypass element disposed between said plunger and the inside surface of said sidewall, said bypass element when dry allowing air to pass through said bypass element to enable fluid entering said chamber through said needle member to displace air from said chamber through said bypass element, and when wet blocking fluid from passing through said bypass element, and remaining at least partially exposed to the interior of said chamber when said chamber is filled with fluid whereby said bypass element is wetted to prevent fluid from leaking from said chamber through said bypass element.

40. A syringe for collecting a blood sample from an artery, said syringe comprising, in combination:

an elongated generally cylindrical housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a hollow needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly including a plunger slidably mounted within said bore, said plunger assembly forming at least a partial sliding liquid and air seal with said sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a blood receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising a bypass element disposed between said plunger and the inside surface of said sidewall;

said bypass element when dry allowing the free passage of air from said chamber through said bypass element to enable blood entering said chamber under arterial pressure through said needle member to displace air from said chamber, and when wetted by blood blocking the passage of blood through said bypass element, and remaining at least partially exposed to the interior of said chamber when said chamber is filled with blood whereby said bypass element is wetted to preclude blood leaking from said chamber through said bypass element.

41. A fluid collection syringe comprising, in combination:

an elongated hollow housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly slidably mounted within said bore said plunger assembly including a plunger having a rim portion forming at least a partial sliding liquid and gas seal with said sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a fluid receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising an annular bypass element disposed over said rim portion between said rim portion and the inside surface of said sidewall, said bypass element when dry allowing gas to pass from said chamber to allow fluid to enter said chamber through said needle member, and when wet blocking gas from passing from said chamber, and being at least partially exposed to the interior of said chamber whereby when said chamber is filled with fluid said bypass element is wetted to prevent fluid from leaking from the chamber.

42. A syringe for collecting a blood sample from an artery, said syringe comprising, in combination:

an elongated generally cylindrical housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly slidably mounted within said bore, said plunger assembly including a plunger having a rim portion forming at least a partial sliding liquid and air seal with said sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a fluid receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising an annular bypass element disposed over said rim portion between said rim portion and the inside surface of sidewall, said bypass element when dry allowing the free passage of air from said chamber to allow blood to enter said chamber under arterial pressure through said needle assembly, and when wetted by said blood blocking the passage of air and blood and being at least partially exposed to the interior of said chamber whereby when said chamber is filled with blood said bypass element is wetted to preclude leaking of blood from said chamber.

43. A fluid collection syringe comprising in combination:

an elongated hollow housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a hollow needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly including a plunger slidably mounted within said bore, said plunger assembly forming at least a partial sliding liquid and gas seal with said sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a fluid receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising a bypass element disposed between said plunger and the inside surface of said sidewall, said pressure relief means automatically closing to the passage of fluid without movement of said plunger upon the chamber becoming filled with fluid.

44. A syringe for collecting a blood sample from an artery, said syringe comprising, in combination:

an elongated generally cylindrical housing having a sidewall defining a central bore, said housing being open at one end to the atmosphere;

a hollow needle member mounted on the other end of said housing, said needle member having a central passageway in communication with said bore;

a plunger assembly including a plunger slidably mounted within said bore, said plunger assembly forming at least a partial sliding liquid and air seal with said sidewall whereby said plunger assembly forms in conjunction with said other end of said housing a blood receiving chamber within said bore having a volume dependent on the position of said plunger assembly; and

said plunger assembly including pressure relief means comprising a bypass element disposed between said plunger and the inside surface of said sidewall, said pressure relief means automatically closing to passage of blood without movement of said plunger upon said chamber becoming filled with blood.