PLASMA EXTRACTION APPARATUS

• US 20070284298A1
• Filed: 08/08/2007
• Published: 12/13/2007
• Est. Priority Date: 05/13/2005
• Status: Active Grant

• Current Assignee: ChroMedX Ltd. (Relay Medical Corp.)
• Original Assignee: ChroMedX Inc.
• Inventors: Samsoondar, James
• Granted Patent: US 7,807,450 B2
• Time in Patent Office: Days
• US Class Current: 210/321.620
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14557 specially adapted to extracorporeal circuits
• CPC Class Codes: A61B 5/150022 for capillary blood or interstitial fluid
• 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 5/150251 Collection chamber divided into at least two compartments, e.g. for division of samples injection syringes having more than one chamber A61M5/19; syringes for injection of two or more media A61M5/2448, A61M5/284; sample preparation for further analysis A61B5/150755
• CPC Class Codes: A61B 5/150343 Collection vessels for collecting blood samples from the skin surface, e.g. test tubes, cuvettes sampling from within body cavities A61B5/150015, A61B5/150045
• CPC Class Codes: A61B 5/150351 Caps, stoppers or lids for sealing or closing a blood collection vessel or container, e.g. a test-tube or syringe barrel caps for bottles or containers in general B65D41/00
• 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 5/150755 Blood sample preparation for further analysis, e.g. by separating blood components or by mixing
• CPC Class Codes: A61B 5/150992 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, valves tubing connectors and couplings A61M39/00

Abstract

Some analyzers cannot measure blood analytes from a sample of whole blood, but can measure the analytes in plasma extracted from the whole blood. Some embodiments of the invention provide a disposable apparatus that is suitable for extracting plasma from whole blood received from a blood supply. The blood supply includes one of a tube containing blood, a syringe containing blood, a drop of blood on the skin resulting from a pin prick, a vein, an artery, and an arterial line. The apparatus includes a housing, and arranged within the housing is a porous membrane, a filtration chamber, and a plasma collection chamber. The porous membrane forms a barrier between the whole blood and the plasma extracted from the whole blood. The filtration chamber receives the whole blood for plasma extraction, and the plasma collection chamber collects the plasma extracted from the whole blood. The apparatus also includes a blood flow path within the housing, and the blood flow path includes the filtration chamber. Means for enabling blood flow in the blood flow path are provided, and means for enabling plasma extraction and plasma removal from the housing are also provided.

Claims

1. An apparatus for extracting plasma from whole blood received from a blood supply, the apparatus comprising:

a housing;

a porous membrane arranged within the housing, forming a barrier between the whole blood and the plasma extracted from the whole blood, the porous membrane having a blood side and a plasma side wherein the blood side is the side of the porous membrane in contact with the whole blood and the plasma side is the side of the porous membrane in contact with the plasma extracted from the whole blood;

a filtration chamber within the housing for receiving the whole blood, the filtration chamber including the blood side of the porous membrane;

a plasma collection chamber within the housing for collecting the plasma extracted from the whole blood, the plasma collection chamber including the plasma side of the porous membrane;

a blood flow path within the housing, the blood flow path including the filtration chamber;

blood flow means for enabling blood flow in the blood flow path;

plasma extraction means for enabling plasma extraction; and

plasma removal means for removing at least some of the plasma out of the housing.

2. An apparatus for extracting plasma from whole blood according to claim 1, wherein the housing further includes a first open end for receiving the whole blood in the blood flow path and fluidly connected to the filtration chamber, and a second open end of the housing for receiving filtered blood from the filtration chamber, the second open end configured to accept the open end of a first syringe, and the blood flow means comprising:

attaching the open end of the first syringe to the second open end of the housing;

inserting the first open end in the blood supply; and

withdrawing the previously pushed in plunger of the first syringe, to provide negative pressure within the filtration chamber for blood flow in the blood flow path.

3. An apparatus for extracting plasma from whole blood according to claim 1, wherein the housing further includes a first open end configured to accept the open end of a first syringe for receiving the whole blood in the flow path, wherein the blood supply is the first syringe containing the blood previously aspirated therein, the blood flow path further including the filtration chamber for receiving the whole blood from the first syringe, and the housing further including a second open end fluidly connected to the filtration chamber, to provide an outflow path for at least air from the flow path, and the blood flow means comprising:

attaching the open end of the first syringe containing whole blood to the first open end of the housing; and

pushing against the plunger of the first syringe, providing positive pressure within the filtration chamber for blood flow in the blood flow path.

4. An apparatus for extracting plasma from whole blood according to claim 1, wherein the housing further includes a first open end for receiving the whole blood in the flow path, the flow path further including the filtration chamber for receiving the whole blood from the first open end, and the housing further including a compressible chamber comprising one or more than one flexible member, the compressible chamber fluidly connected to the filtration chamber, and the blood flow means comprising:

squeezing the one or more than one flexible member of the compressible chamber;

inserting the first open end in the blood supply; and

releasing the one or more than one flexible member of the compressible chamber, to provide negative pressure within the filtration chamber for blood flow in the blood flow path.

5. An apparatus for extracting plasma from whole blood according to claim 2, wherein the housing further includes a third open end in fluid connection with the plasma collection chamber, the third open end configured to receive the open end of a second syringe, and wherein plasma extraction means comprises:

attaching the open end of the second syringe to the third open end of the housing; and

at least partly withdrawing the previously pushed in plunger of the second syringe during the blood flow, to provide negative pressure within the plasma collection chamber for plasma extraction;

and wherein the plasma removal means comprises;

aspirating at least some of the plasma from the plasma collection chamber into the second syringe; and

detaching the second syringe containing the plasma, from the housing.

6. An apparatus for extracting plasma from whole blood according to claim 3, wherein the housing further includes a third open end in fluid connection with the plasma collection chamber, the third open end configured to receive the open end of a second syringe, and wherein plasma extraction means comprises:

attaching the open end of the second syringe to the third open end of the housing; and

partly withdrawing the previously pushed in plunger during the blood flow, to provide negative pressure within the plasma collection chamber for plasma extraction;

and wherein the plasma removal means comprises;

aspirating at least some of the plasma from the plasma collection chamber into the second syringe; and

detaching the second syringe containing the plasma, from the housing.

7. An apparatus for extracting plasma from whole blood according to claim 4, wherein the housing further includes a second open end in fluid connection with the plasma collection chamber, the second open end configured to receive the open end of a syringe, and wherein plasma extraction means comprises:

attaching the open end of the syringe to the second open end of the housing; and

partly withdrawing the previously pushed in plunger of the syringe during the blood flow, to provide negative pressure within the plasma collection chamber for plasma extraction;

and wherein the plasma removal means comprises;

aspirating at least some of the plasma from the plasma collection chamber into the second syringe; and

detaching the second syringe containing the plasma, from the housing.

8. An apparatus for extracting plasma from whole blood according to claim 1, wherein the housing further includes:

a first open end for receiving the whole blood in the blood flow path and fluidly connected to the filtration chamber, and the housing further including a first compressible chamber comprising one or more than one flexible member for squeezing, the first compressible chamber fluidly connected to the filtration chamber; and

a second open end for plasma removal means, fluidly connected to the plasma collection chamber, the plasma collection chamber fluidly connected to a second compressible chamber comprising one or more than one flexible member for squeezing, provided for the plasma extraction means and the plasma removal means, wherein the position of the second compressible chamber relative to the first compressible chamber provides for squeezing the first compressible chamber and the second compressible chamber simultaneously, and wherein the second open end is configured to receive a cap for sealing the second open end;

and wherein the blood flow means and the plasma extraction means comprising;

sealing the second open end with the cap;

simultaneously squeezing the first compressible chamber and the second compressible chamber, for removing air from the filtration chamber and the plasma collection chamber;

inserting the first open end in the blood supply; and

simultaneously releasing the first compressible chamber and the second compressible chamber, to provide negative pressure within the filtration chamber for blood flow in the blood flow path, and to provide negative pressure within the plasma collection chamber for plasma extraction;

and wherein the plasma removal means comprises;

removing the cap from the second open end after the plasma extraction; and

squeezing the second compressible chamber, to provide positive pressure for ejecting at least some of the plasma out of the second open end.

9. An apparatus for extracting plasma from whole blood according to claim 1, wherein the housing further includes:

a first open end for receiving the whole blood in the blood flow path and fluidly connected to the filtration chamber, and the housing further including a first compressible chamber comprising one or more than one flexible member for squeezing, the first compressible chamber fluidly connected to the filtration chamber; and

a second open end for the plasma removal means, fluidly connected to the plasma collection chamber, the plasma collection chamber fluidly connected to a second compressible chamber comprising one or more than one flexible member for squeezing, provided for the plasma extraction means and the plasma removal means, wherein the second open end is configured to receive a cap for sealing the second open end;

and wherein the blood flow means and the plasma extraction means comprising;

sealing the second open end with the cap;

squeezing the first compressible chamber and the second compressible chamber, for removing air from the filtration chamber and the plasma collection chamber;

inserting the first open end in the blood supply; and

releasing the first compressible chamber to provide negative pressure within the filtration chamber for blood flow in the blood flow path, and releasing the second compressible chamber to provide negative pressure within the plasma extraction chamber for plasma extraction;

and wherein the plasma removal means comprises;

removing the cap from the second open end after the plasma extraction; and

squeezing the second compressible chamber, to provide positive pressure for ejecting at least some of the plasma out of the second open end.

10. An apparatus for extracting plasma from whole blood according to claim 9, wherein the one or more than one flexible member of the first compressible chamber possesses rebound after squeezing, the speed of the rebound sufficient for adequate flow of the whole blood, and wherein the one or more than one flexible member of the second compressible chamber possesses rebound after squeezing, the speed of the rebound sufficient for adequate plasma extraction.

11. An apparatus for extracting plasma from whole blood according to claim 1, wherein the blood flow path begins at the sharp open end of a hollow needle.

12. An apparatus for extracting plasma from whole blood according to claim 1, wherein the blood supply includes one of a tube containing blood, a syringe containing blood, a drop of blood on the skin resulting from a pin prick, a vein, an artery, and an arterial line.

13. An apparatus for extracting plasma from whole blood according to claim 1, wherein the porous membrane is configured as one or more than one hollow fiber filter assembled between two flanges, and at least one of the two flanges is perforated, wherein the plasma collection chamber includes the inside of the one or more than one hollow fiber filter, or the filtration chamber includes the inside of the one or more than one hollow fiber.

14. An apparatus for extracting plasma from whole blood according to claim 13, wherein the one or more than one hollow fiber filter runs approximately orthogonal to the direction of blood flow in the blood flow path, and wherein the plasma collection chamber includes the inside of the hollow fiber filter.

15. An apparatus for extracting plasma from whole blood according to claim 13, wherein the one or more than one hollow fiber filter runs approximately parallel to the direction of the blood flow, the plasma collection chamber includes the outside of the hollow fiber filter.

16. An apparatus for extracting plasma from whole blood according to claim 1, wherein at least one portion inside the apparatus contains an anticoagulant.

17. An apparatus for extracting plasma from whole blood received from a blood supply, the apparatus comprising:

a housing;

a porous membrane arranged within the housing, forming a barrier between the whole blood and the plasma extracted from the whole blood, the porous membrane having a blood side and a plasma side wherein the blood side is the side of the porous membrane in contact with the whole blood and the plasma side is the side of the porous membrane in contact with the plasma extracted from the whole blood;

a first open end in the housing for receiving the whole blood;

a filtration chamber within the housing for receiving the whole blood from the first open end, the filtration chamber including the blood side of the porous membrane;

a blood flow path within the housing, beginning at the first open end and terminating at a compressible chamber, the compressible chamber fluidly connected to the filtration chamber;

a plasma collection chamber within the housing for collecting the plasma extracted from the whole blood, the plasma collection chamber beginning at the plasma side of the porous membrane, and terminating at a second open end in the housing, the second open end configured for attachment of a syringe for plasma extraction means and plasma removal means.

18. An apparatus for extracting plasma from whole blood according to claim 17, wherein the porous membrane is configured as one or more than one hollow fiber filter assembled between two flanges, and at least one of the two flanges is perforated, wherein the plasma collection chamber includes the inside of the one or more than one hollow fiber filter, or the filtration chamber includes the inside of the one or more than one hollow fiber.

19. An apparatus for extracting plasma from whole blood received from a blood supply, the apparatus comprising:

a housing;

a porous membrane arranged within the housing, forming a barrier between the whole blood and the plasma extracted from the whole blood, the porous membrane having a blood side and a plasma side wherein the blood side is the side of the porous membrane in contact with the whole blood and the plasma side is the side of the porous membrane in contact with the plasma extracted from the whole blood;

a first open end in the housing for receiving the whole blood;

a filtration chamber within the housing for receiving the whole blood from the first open end, the filtration chamber including the blood side of the porous membrane;

a blood flow path within the housing, beginning at the first open end and terminating at a second open end in the housing, the second open end fluidly connected to the filtration chamber and configured for attachment of a syringe for plasma flow means;

a plasma collection chamber within the housing for collecting the plasma extracted from the blood, the plasma collection chamber beginning at the plasma side of the porous membrane, and terminating at a third open end in the housing, the third open end configured for attachment of a syringe for plasma extraction means and plasma removal means.

20. An apparatus for extracting plasma from whole blood according to claim 19, wherein the porous membrane is configured as one or more than one hollow fiber assembled between two flanges, and at least one of the two flanges is perforated, wherein the plasma collection chamber includes the inside of the one or more than one hollow fiber, or the filtration chamber includes the inside of the one or more than one hollow fiber.