Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3890237 A
Publication typeGrant
Publication dateJun 17, 1975
Filing dateFeb 27, 1974
Priority dateFeb 27, 1974
Publication numberUS 3890237 A, US 3890237A, US-A-3890237, US3890237 A, US3890237A
InventorsJoseph T Welch
Original AssigneeBecton Dickinson Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Plasma separator {13 {0 cord stop type
US 3890237 A
Abstract
A blood collection and separator assembly of the type suitable for use in centrifuging blood to separate the plasma or serum, the light phase, from the cellular portion, the heavy phase. The assembly includes a collection container and a piston disposed therein for sealing off one phase from the other after centrifuging is terminated. The piston is formed having a specific gravity heavier than the light phase of the blood. The piston is slidably disposed in the container with its outer surfaces in sealing contact with the inner surface of the container and is provided with means which, under sufficient centrifugal force, permit the light phase of the blood to pass the piston as the piston moves down through the light phase while retaining sealing engagement with the inner surface of the container. Cord means interconnecting the piston and the top closure of the container stop the piston at a predetermined distance above the bottom of the container whereupon the piston serves as an impervious barrier between the two phases of the blood.
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent Welch June 17, 1975 i 1 PLASMA SEPARATOR CORD STOP TYPE [75] Inventor: Joseph T. Welch, Wanaque, NJ, [57] ABSTRACT {73] sigma Becmn Dickinsnn and Company A blood collection and separator assembly of the type E35t RLthen-ord N J suitable for use in centrifuging blood to separate the v plasma or serum, the light phase, from the cellular i 1 Filedl 1974 portion, the heavy phase. The assembly includes a collection container and a piston disposed therein for 3 [21] Appl' sealing off one phase from the other after centrifuging 52 us. on 210/516; 210/010. 23 is terminated- The Piston is formed having a specific 511 int. c| Btlld 21/26 gravity heavier than the light phase of the blood- The 53 n w f Search 23 5 5 59 230 B7 292; piston is slidably disposed in the container with its l28/2l4 R,272, 2 F; 210/83184, 131 359, 210/514-518, DIG. 23, DIG. 24;

233/1 A,l R,26

[56} References Cited UNITED STATES PATENTS 3,508,653 4/l970 Coleman ZlO/DiG. 23

3,779,383 12/1973 Ayrcs 1 ZlO/DIG. 23 3,786,985 H1974 Blaivas ZIOIDIGA 24 Primary ExaminerFrank A. Spear, Jr. Assistant Examiner-Robert G. Mukai Attorney, Agent, or FirmKane, Dalsimer, Kane, Sullivan and Kurucz outer surfaces in sealing contact with the inner surface of the container and is provided with means which, under sufficient centrifugal force, permit the light phase of the blood to pass the piston as the piston moves down through the light phase while retaining sealing engagement with the inner surface of the container. Cord means interconnecting the piston and the top closure of the container stop the piston at a predetermined distance above the bottom of the container whereupon the piston serves as an impervious barrier between the two phases of the blood.

2 Claims, 2 Drawing Figures PLASMA SEPARATOR CORD STOP TYPE BACKGROUND OF THE INVENTION It is known to separate blood into its component parts by centrifugation, for example, the assembly disclosed in US. Pat. No. 2,460,641. However, this particular assembly does not employ a means for sealing the separated plasma or serum phase from the cellular phase.

It is also known to provide assemblies for manually separating the plasma or serum phase from the cellular phase, for example. as disclosed in US. Pat. Nos. 3,586,064; 3,661,265; 3,355,098; 3.481,477; 3,512,940; and 3,693,804. In all of these devices the serum is collected in a blood collection container and means are provided for separating the plasma or serum phase from the cellular phase employing filters, valves, transfer tubes or the like.

It is also known to provide assemblies for the sealed separation of blood in which a piston is actuated by centrifugal force such as is disclosed in US. Pat. Nos. 3,508,653 and 3,779,383. These devices use either a resilient piston or valve means associated with the piston to effect a sealed separation after centrifugation.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a serum/plasma separator assembly including a collection container and a piston slidably disposed in the container, which piston has means permitting, under sufficient centrifugal force, the light phase of the blood to pass the piston as the piston moves through the light phase, means to stop the piston at a predetermined distance above the bottom of the container, and means to seal the piston in the container at the plasma/serumcellular interface.

It is another object of the invention to provide a serum/plasma separator assembly which is economical to manufacture and can be used in conjunction with standard blood collecting equipment.

DESCRIPTION OF THE DRAWINGS For a better understanding of the invention, references are made to the drawings which illustrate the preferred embodiment of the invention herein.

FIG. 1 is a sectional, elevational view showing the plasma/serum separator assembly of the present invention and also illustrating a pointed cannula penetrating one of the stoppered ends of the container through which blood is introduced into the container prior to blood separation into its light and heavy phases.

FIG. 2 is a sectional, elevational view similar to the view of FIG. 1, showing the piston stopped at a predetermined distance above the bottom of the container determined by the length of the cord connecting the top closure to the piston, said piston sealing the container at the plasma/serum-cellular interface.

DESCRIPTION OF THE PREFERRED EMBODIMENTS For a better understanding of the invention herein a description of the drawings of the illustrative embodiments is had with particular reference to FIGS. 1 and 2.

In FIG. 1 the separator assembly comprises a tubular member or container 11 which is sealed at its open ends by closure members 12 and 13. Such tubular member or container is preferably formed of glass but any other suitable material may be employed. Closure members 12 and 13 are preferably made of rubber. Closure 12 is capable of being penetrated by a cannula 14, so that blood can be transferred from a blood source into the container under aseptic conditions. The closures 12 and 13 are preferably made of elastomeric material and should be self-sealing so that when the cannula 14 is removed from the closure 12 there will be no loss of blood.

Disposed in container 11 is piston 15 which is preferably made of an elastomeric material and is made to provide an interference fit within container 11. The piston is formed of material having a specific gravity heavier than the liquid phase of blood. After cannula 14 is removed, the assembly is centrifuged first at a low speed and later at a high speed. Piston I5 is made with sufficient friction to stay up during low speed spin but move downwardly during the high speed spin, down through the plasma/serum phase, from the initial starting position illustrated in FIG. 1 to the terminal position after the separation of the light phase from the heavy phase as shown in FIG. 2.

The elastomeric (preferably rubber) portion of piston 15 has one or more very flexible axially spaced sealing fins 15a encircling the periphery of the piston. These fins contact the inner wall surface of the container 11 in sealing engagement. Such fins preferably extend in a diagonally upward direction so that when centrifugal force is applied to the assembly the fins will yield and permit the liquid phase to pass up around the outer periphery of the piston as the piston descends. When the piston has reached its stopping point just above the interface these fins will reestablish a seal relative to the inner wall 11a of the container 11.

One end of cord 16 is secured to the piston 15 and at the other end to the closure member 13. Such a cord can be a moncfilament of plastic or other suitable material. The closure member 13 is provided with a recess 13a so that the cord can be coiled within the recess. The cord is ofa predetermined length to stop the piston 15 at a predetermined distance from the bottom of the container. Such a cord is made to position the piston slightly above the serum/plasma-cellular interface.

As illustrated in FIG. 2, piston 15 has completed its travel within container 11 and is stopped from further downward movement in container 11 by the cord stop means and the piston fins are rescaled relative to the tube 11. Also a portion of the light phase remains above the separated heavy phase and is not utilized as part of the separated light phase.

When operating the separator assembly of the invention herein it is preferred that the assembly be evacuated so that when cannula l4 penetrates closure 12 blood will fill container 11. It is also important when filling the assembly 10 that blood be introduced into container 11 through the stopper 12 mounted on the bottom of the container to obviate the possibility of having blood cells trapped between the piston 15 and stopper 13 which will later separate to form the chamber where the light phase will be collected. Blood cells above piston 15 would contaminate the serum/plasma.

When the centrifuging is terminated, the separated blood sample is ready for use. As desired, the serum or plasma can be taken from one end and/or the concentrated red cells can be taken from the other end.

3 4 While variations of the invention herein may be had, greater centrifugal force so that when said conthe objectives of the invention have been illustrated tainer is subjected to said first centrifugal force the and described. blood separates into its light phase and heavy phase Having described the invention what is claimed is: but the piston stays in said first position and subsel. A separator assembly, capable of separating blood 5 quently when said second greater centrifugal force into its component phases of plasma or serum vs celluis used the sealing means automatically disengages, lar portion. comprising: the light phase thereby passing around the sealing a. a container having first and second open ends, and means enabling the piston to move down through adapted to receive blood for subsequent separation the light phase; and into a light phase and a heavy phase; n d stop means comprising a cord of a predetermined b. first and second closures sealing both ends of the length extending from said second closure to the container. the first of said closures being formed piston whereby the piston when moving through from a self-sealing elastomeric material which is the light phase will stop a predetermined distance penetrable by a cannula through which blood to be from said first end of the container. separated is conducted into the container; 2. The separator of claim 1 wherein the sealing c. a piston having a specific gravity relatively greater means associated with the said piston comprises flexithan the light phase of the blood and slidably ble sealing fins on the outer surface of the piston in mounted in the container, said piston having means sealing engagement with an inner surface of the conon an outer surface in sealing engagement with an tainer which fins are slanted in an upward direction and inner surface of the container, said sealing means are adapted when centrifugal force is applied to the asbeing constructed and arranged to maintain said sembly to permit the light phase to pass around the pepiston at a first position adjacent the second of said riphery of the piston when the piston moves down closures when subjected to a first centrifugal force through the light phase.

and to disengage when subjected to a second

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3508653 *Nov 17, 1967Apr 28, 1970Charles M ColemanMethod and apparatus for fluid handling and separation
US3779383 *Apr 25, 1972Dec 18, 1973Becton Dickinson CoSealed assembly for separation of blood components and method
US3786985 *Jan 5, 1973Jan 22, 1974Hoffmann La RocheBlood collection container
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4811866 *Jan 2, 1987Mar 14, 1989Helena Laboratories CorporationMethod and apparatus for dispensing liquids
US4818386 *Oct 8, 1987Apr 4, 1989Becton, Dickinson And CompanyDevice for separating the components of a liquid sample having higher and lower specific gravities
US5106178 *Dec 14, 1990Apr 21, 1992Minoru AkiyoshiPrescription lens holder for use with sunglasses
US5851397 *May 1, 1997Dec 22, 1998Itoh; TeruakiAuxiliary apparatus for sampling blood serum
US5980734 *Sep 11, 1998Nov 9, 1999Itoh; TeruakiAuxiliary apparatus for sampling blood serum
US6479298 *Dec 3, 1999Nov 12, 2002Becton, Dickinson And CompanyDevice and method for separating components of a fluid sample
US7074577Oct 3, 2002Jul 11, 2006Battelle Memorial InstituteBuffy coat tube and float system and method
US7220593Oct 3, 2002May 22, 2007Battelle Memorial InstituteBuffy coat separator float system and method
US7329534Mar 7, 2006Feb 12, 2008Battelle Memorial InstituteFor use in separation and axial expansion of constituent fluid components layered by centrifugation; system includes a transparent, or semi-transparent, flexible sample tube and a rigid separator float having a specific gravity intermediate that of red blood cells and plasma
US7358095Dec 11, 2006Apr 15, 2008Battelle Memorial InstituteDiameter of transparent, flexible tube increases with centrifugal force, permits density-based axial movement of blood; optical analysis; reduced centrifugation speed decreases tube failure, less contamination
US7629176Feb 11, 2008Dec 8, 2009Battelle Memorial InstituteBuffy coat separator float system and method
US7915029Feb 11, 2008Mar 29, 2011Battelle Memorial InstituteBuffy coat tube and float system and method
US7919049Nov 9, 2009Apr 5, 2011Battelle Memorial InstituteBuffy Coat separator float system and method
US7947236Feb 24, 2004May 24, 2011Becton, Dickinson And Companyunitary separator having an overall density between the heavier and light fractions capable of moving between the fractions upon centrifugation, and sealing the fractions from one another when centrifugation ends.
US8012742Mar 21, 2011Sep 6, 2011Battelle Memorial InstituteBuffy coat tube and float system and method
US8114680 *Mar 21, 2011Feb 14, 2012Battelle Memorial InstituteBuffy coat separator float system and method
US8394342Jul 21, 2009Mar 12, 2013Becton, Dickinson And CompanyDensity phase separation device
US8524171Apr 13, 2011Sep 3, 2013Becton, Dickinson And CompanyDevice for separating components of a fluid sample
US8747781Jul 21, 2009Jun 10, 2014Becton, Dickinson And CompanyDensity phase separation device
US8794452Aug 1, 2013Aug 5, 2014Becton, Dickinson And CompanyDensity phase separation device
Classifications
U.S. Classification210/516, 210/789, 422/918
International ClassificationB01L3/14
Cooperative ClassificationB01L3/50215
European ClassificationB01L3/50215