Syringe for obtaining a target volume of blood

Patent metadata

Field	Value
Publication number	US-12575771-B2
Application number	US-202017756825-A
Country	US
Kind code	B2
Filing date	Dec 16, 2020
Priority date	Dec 18, 2019
Publication date	Mar 17, 2026
Grant date	Mar 17, 2026

Abstract

A syringe for obtaining a target volume of blood is presented. The syringe ( 1 ) comprises a barrel ( 2 ), wherein a plunger ( 4 ) is arranged within the barrel ( 2 ) to be displaceable along a displacement direction (X). Furthermore the barrel ( 2 ) and the plunger ( 4 ) together provide for a first stop ( 20 ) and second stop ( 22 ), wherein the first stop ( 20 ) is configured for positioning a filter ( 100 ) at a predetermined location along the displacement direction (X) thereby defining a target volume of blood and a buffer volume. Moreover, the second stop ( 22 ) is configured to stop the plunger ( 4 ) from expelling more than the buffer volume from the syringe ( 1 ) for obtaining the target volume of blood when the plunger ( 4 ) is pushed towards the distal end ( 30 ) of the syringe ( 1 ) along the displacement direction (X). In addition, the syringe ( 1 ) facilitates that the syringe ( 1 ) fills itself with the target volume of blood by a self-filling procedure using blood that is under pressure, like arterial blood, and using the filter ( 100 ) located in the plunger ( 4 ).

First claim

The invention claimed is:

1 . A syringe for obtaining a target volume of blood, the syringe comprising:
(a) a barrel; and (b) a plunger, wherein:
(i) the plunger is arranged within the barrel to be displaceable along a displacement direction,
(ii) the plunger comprises a filter,
(iii) a barrel first portion of the barrel and a plunger first portion of the plunger together provide for a first stop and a barrel second portion of the barrel and a plunger second portion of the plunger together provide for a second stop,
(iv) the first stop is configured for positioning the filter at a predetermined location along the displacement direction thereby defining a target volume of blood and a buffer volume of blood,
(v) the second stop is configured to stop the plunger from expelling more than the buffer volume for obtaining the target volume of blood when the plunger is pushed towards a distal end of the syringe along the displacement direction,
(vi) the barrel comprises a proximal end at which a first opening for introducing the plunger into the barrel is located,
(vii) at the distal end of the barrel, a second opening for receiving the target volume of blood is located,
(viii) the barrel second portion is located closer to the first opening than the barrel first portion,
(ix) the filter is configured to be gas-permeable when the filter is not in contact with blood, and wherein the filter is configured to become gas-impermeable when getting in contact with blood,
(x) the plunger is fluid-sealing when the filter is gas-impermeable, and
(xi) the plunger is configured for guiding air out of the barrel and through the filter towards outside the syringe during a self-filling process of the syringe.

2 . The syringe according to claim 1 ,
wherein the plunger comprises a channel, wherein the filter is positioned inside the channel, and wherein the channel is configured for guiding the air out of the barrel and through the filter towards outside the syringe during the self-filling process of the syringe.

3 . The syringe according to claim 2 ,
wherein the channel has a first aperture at a proximal end of the plunger, wherein the channel has a second aperture at a distal end of the plunger, wherein the filter is located at least partially inside the channel and in-between the first aperture and the second aperture of the channel, wherein the filter is configured for ventilating gas through the channel of the plunger, when the filter is gas-permeable, and wherein the filter is configured for sealing the channel of the plunger fluid-tightly, when the filter is gas-impermeable.

4 . The syringe according to claim 1 ,
wherein the syringe comprises a ventilation tip cap on a tip of the syringe, wherein the ventilation tip cap is configured for preventing air from moving through the tip into the syringe, and wherein the ventilation tip cap is configured for allowing air to be pushed from inside the syringe to outside of the syringe through the ventilation tip cap when the plunger is moved along the displacement direction.

5 . The syringe according to claim 1 ,
wherein the first and/or the second stop each define a stopping function along the displacement direction, wherein the respective stopping function is generated by form fit, friction fit, and/or adhesion between the plunger and the barrel.

6 . The syringe according to claim 1 ,
wherein the plunger first portion comprises a first protrusion on a surface of the plunger, wherein the barrel first portion comprises a second protrusion on an internal surface of the barrel, wherein the second protrusion and the first protrusion together form the first stop, wherein the plunger second portion comprises a third protrusion, wherein the barrel second portion comprises a cone on an internal surface of the barrel at the first opening, and wherein the third protrusion and the cone together form the second stop.

7 . The syringe according to claim 6 ,
wherein the internal surface of the barrel has an at least mainly constant diameter along the displacement direction and is configured to store a liquid, and wherein the first, second and/or third protrusion extend continuously around the barrel and/or the plunger.

8 . The syringe according to claim 6 , wherein the internal surface of the barrel forms a cone which extends radially around the displacement direction and is configured to orientate the plunger into the cone when inserting the plunger into the barrel.

9 . The syringe according to claim 8 , wherein the cone is formed at the first opening of the barrel.

10 . The syringe according to claim 1 , wherein the barrel has an at least partially constant diameter, wherein a ratio between the at least partially constant diameter and a maximum displacement length along the displacement direction is from 1:1.5 and 1:8.

11 . The syringe according to claim 1 , wherein the plunger first portion is configured to translate past the barrel first portion upon an insertion of the plunger into the barrel.

12 . The syringe according to claim 1 , wherein a body of the barrel extends from the proximal end to the distal end and is integral with a body first stop portion of the first stop.

13 . A method of filling a syringe with a target volume of blood, the method comprising:
providing a syringe comprising:
(a) a barrel comprising a first barrel structure and a second barrel structure; and
(b) a plunger comprising a filter, a first plunger structure, and a second plunger structure,
wherein:
(i) the plunger is arranged within the barrel to be displaceable along a displacement direction,
(ii) the first barrel structure and the first plunger structure are configured to cooperate together to form a first stop and the second barrel structure and the second plunger structure are configured to cooperate together to form a second stop,
(iii) the first stop is configured for positioning the filter at a predetermined location along the displacement direction thereby defining a target volume of blood and a buffer volume, and
(iv) the second stop is configured to stop the plunger from expelling more than the buffer volume for obtaining the target volume of blood when pushed towards a distal end of the syringe along the displacement direction,
(v) guiding blood into the syringe causing air to move from the barrel through the filter of the plunger towards outside of the syringe as long as the filter is not in contact with blood,
(vi) causing a contact of the blood with the filter thereby changing a permeability of the filter from being gas-permeable when the filter is not in contact with blood to being gas-impermeable when getting into the contact with blood, and
(vii) fluid tightly sealing the plunger by changing the permeability of the filter into being gas-impermeable.

14 . The method according to claim 13 , wherein the method further comprises:
pushing air from inside the syringe, out of the syringe through a tip of the syringe by moving the plunger from a barrel first portion of the first stop to a barrel second portion of the second stop.

15 . The method according to claim 14 , wherein air is pushed from the barrel.

16 . The method according to claim 14 , wherein air is pushed through a ventilation tip cap of the syringe.

17 . A method comprising:
providing a syringe according to claim 1 ; and obtaining blood from a human or animal using the syringe.

18 . A syringe for obtaining a target volume of blood, the syringe comprising:
(a) a barrel, and (b) a

Assignees

• Radiometer Medical Aps

Inventors

• Lykke Jacob
• Nørgaard Louise Wagner

Classifications

• A61B5/150351

  Caps, stoppers or lids for sealing or closing a blood collection vessel or container, e.g. a test-tube or syringe barrel · CPC title

• A61B5/150213

  Venting means · CPC title

• A61B5/153

  {Devices} specially adapted for taking samples of venous or arterial blood, e.g. with syringes · CPC title

• A61B5/150992

  Blood sampling from a fluid line external to a patient, such as a catheter line, combined with an infusion line; Blood sampling from indwelling needle sets, e.g. sealable ports, luer couplings or valves · CPC title

• A61B5/150244

  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 title