Filtering in pre-evacuated containers

• US 10,531,822 B2
• Filed: 08/27/2016
• Issued: 01/14/2020
• Est. Priority Date: 08/10/2012
• Status: Active Grant

• Current Assignee: Serumdpt Bioscience LLC
• Original Assignee: Jean I. Montagu
• Inventors: Montagu, Jean I, Bell, William, Montagu, Sasha
• Primary Examiner(s): Spies, Bradley R
• Application Number:
  US15/330,225
• Publication Number:
  US 20170065217A1
• Time in Patent Office: 1,235 Days
• Field of Search: None
• CPC Class Codes: A61B 5/1411 by percutaneous method, e.g. by lancet
• CPC Class Codes: A61B 5/15003 for venous or arterial blood
• CPC Class Codes: A61B 5/150213 Venting means
• 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 5/150351 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 5/15074 Needle sets comprising wings, e.g. butterfly type, for ease of handling
• 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 5/150946 Means for varying, regulating, indicating or limiting the speed or time of blood collection
• 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
• CPC Class Codes: A61B 5/153 Devices specially adapted for taking samples of venous or arterial blood, e.g. with syringes
• CPC Class Codes: A61B 5/154 Devices using pre-evacuated means
• CPC Class Codes: A61B 5/155 Devices specially adapted for continuous or multiple sampling, e.g. at predetermined intervals devices loaded with multiple lancets simultaneously A61B5/15146
• CPC Class Codes: A61M 1/0259 Apparatus for treatment of blood or blood constituents not otherwise provided for for agitating A61M1/025; for separating blood components present in distinct layers in a container A61M1/029
• CPC Class Codes: B01D 61/22 Controlling or regulating
• CPC Class Codes: B01D 71/04 Glass
• CPC Class Codes: G01N 33/48 Biological material, e.g. blood, urine G01N33/02, G01N33/26, G01N33/44, G01N33/46 take precedence; Haemocytometers counting blood corpuscules distributed over a surface by scanning the surface G06M11/02
• CPC Class Codes: G01N 33/491 by separating the blood components G01N15/05 takes precedence

Abstract

An independent blood filter device depends on flow geometry to deliver blood serum or plasma free of detrimental levels of hemoglobin. It depends critically on an upstream flow rate or pressure differential limiting control element or device that limits the rate of change of pressure differential across the filter element. Pre-evacuated versions can be used to simultaneously draw blood from a living being and provide pressure differential across the filter element between an evacuated collector and a supply end open to atmosphere. A unit pressurized by hand motion employs the external shape of a partially filled blood collection tube as a piston to produce pressure in advance of the control element or device to create the pressure differential across the filter element to a collector vented to atmosphere. The control element or device is disclosed in numerous forms, including specially sized flow constrictions and compliant arrangements.

Claims

1. A filtering device for filtering blood to obtain serum or plasma in a container, the container having access at both ends, a filter located within the container, and a flow rate or pressure differential limiting control element or device, the limiting element or device being located upstream of the filter and including a flexible tubing length located outside of the container, the control element or device being constructed to limit increase in the pressure differential rate of change across the filter to about 10 mmHg thus substantially eliminating hemolysis associated with the filter.

2. The filtering device of claim 1 in which the container is partially evacuated.

3. The filtering device of claim 2 wherein the limiting control element or device is located outside the container.

4. The filtering device of claim 3 wherein the limiting control element or device is integral with a blood drawing needle assembly.

5. The filtering device of claim 1 wherein the container during operation is partially pressurized.

6. The filtering device of claim 1 wherein the limiting control element or device is located inside the container.

7. A filtering device for filtering blood to obtain serum or plasma, comprising a pre-evacuated container, a filter located within the container, and a flow rate or pressure differential limiting control element or device comprises a selected length of capillary tubing.

8. The filtering device of claim 7 wherein the flow rate or pressure differential limiting control element or device is in the form of a pin hole or pin holes in a flow-blocking disk.

9. The filtering device of claim 7 wherein the control element or device comprises a fine mesh or porous foam.

10. The filtering device of claim 7 wherein the control element or device comprises a passage defined by a screw like segment.

11. A filtering device for filtering blood to obtain serum or plasma, comprising a pre-evacuated container, a filter located within the container, and a flow rate or pressure differential limiting control element or device constructed to limit differential pressure across the filter by restricting flow toward the filter, wherein the limiting element or device is constructed to passively limit increase in the pressure differential rate of change across the filter to about 10 mmHg and thereby substantially reduce hemolysis associated with the filter.

12. The filtering device of claim 11 wherein the limiting control element or device is preceding the filter and limits entering flow-rate of whole blood drawn from a living being.

13. The filtering device of claims 11 wherein it has a limiting control element or device preceding the filter that defines entering pressure increase rate in whole blood drawn from a living being.

14. The filtering device of claims 11 wherein it is portable or hand held, and includes a volume sized for blood drawn from a living being.

15. The filtering device of claims 11 wherein the material of the filter comprises glass microfibers and micro-porous membrane on a locating support.

16. The filtering device of claims 11 in which the container includes a tube.

17. The filtering device of claims 11 having an access septum at the inlet end of the container.

18. The filtering device of claim 17 having an access septum at the outlet end of the container.

19. The filtering device of claim 11 wherein the flow rate limiting control element is integral with a blood drawing needle assembly.

20. A method of obtaining blood serum or plasma using the filtering device of claim 11.

21. A device comprising a pre-evacuated container, and a flow rate limiting control element limiting pressure and including capillary restriction for blood flow into the container and being constructed to provide said capillary restriction according to the Hagen-Poiseuille law for a designed capillary radius, capillary length and pressure drop.

22. The device of claim 21, wherein the pre-evacuated container includes a tube.

23. The device of claim 22, wherein the tube includes inlet and outlet ends with access at both ends.

24. The device of claim 21 including a blood drawing needle assembly.

25. The device of claim 21, wherein the blood drawing needle assembly includes said capillary restriction.

26. A method of obtaining blood serum or plasma by filtering blood using the device of claim 21.