CA1050509A - Telescoping serum separator and dispenser - Google Patents
Telescoping serum separator and dispenserInfo
- Publication number
- CA1050509A CA1050509A CA253,130A CA253130A CA1050509A CA 1050509 A CA1050509 A CA 1050509A CA 253130 A CA253130 A CA 253130A CA 1050509 A CA1050509 A CA 1050509A
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- Canada
- Prior art keywords
- container
- serum
- aperture
- platform
- compartment
- Prior art date
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Abstract
TELESCOPING SERUM SEPARATOR AND DISPENSER
Abstract of the Disclosure A serum separation and dispensing device comprises two containers one movably mounted partially within the other, the end wall of one being sealed, in the contracted position, against the open end of the other, to hold a vacuum prior to drawing blood into the device.
Abstract of the Disclosure A serum separation and dispensing device comprises two containers one movably mounted partially within the other, the end wall of one being sealed, in the contracted position, against the open end of the other, to hold a vacuum prior to drawing blood into the device.
Description
CKGROUND O~ Tl-IE INVENTION
1) Field of the Invention This invention generally relates to a container ` which provides for the collection of a sample of a biological fluid, the centrifugation of the fl-uid in the case of serum, and accurate dispensing of micro amounts of the fluid for testing, all without-requiring the pouring of the fluid into a variety of separate containers. More specifically, it relates to improved devic`es for providing the combined functions of - 10 serum separation and dispensing. -:'': ..
1) Field of the Invention This invention generally relates to a container ` which provides for the collection of a sample of a biological fluid, the centrifugation of the fl-uid in the case of serum, and accurate dispensing of micro amounts of the fluid for testing, all without-requiring the pouring of the fluid into a variety of separate containers. More specifically, it relates to improved devic`es for providing the combined functions of - 10 serum separation and dispensing. -:'': ..
2) State of the Prior Art ~' The most common conventional method of providing - ~ -biological fluid such as blood serum for clinical analysis utilizes a plurality of containers en route to the actual test.
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`!, ; That is, the blood sample is conventionally collected in an evacuated container, and separation of the serum from the whole cells may be achieved by centrifuging the sample within that -~
' contalnerg or wlthin another container to which the sample has .i ~ Oeen transferred. Thereafter, the serum is commonly poured off ~1~ 20~ into yet another container for the desired clinical testing.
All such transfer operations are time consuming, requiring either hand.prccessing or complicated, expensive automatic handling. Furthermore, whenever the~e is a transfer of a ;
liquid sample to a separate~ open container, the sample is aerated~and C02 loss or galn can occur. There is also the danger of~improper transfer, either by the use of the wrong container, by the improper patient labeling of the new con-tainer, or by both. Still further, contamination of the serum by foreign materials or ~in~ection of the operator can occur.
Reuse of the same dispensing device for sequential samples requires careful sterili~ation to a-oid contamination. Thus, a ¦~
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; tem which keeps ~he ~lood sample conrined to essentially one container from its collection to the actual dispensing for analysis is a distinct, sought~after improvement.
~t the centrifuging stage~ a variety of means have been provided for more or less plugging the serum-cell interface ;
that is formed during centrifuging, whereby remixing of the cells and serum is prevented. U.S. Patent Nos. 3,647,070;
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`!, ; That is, the blood sample is conventionally collected in an evacuated container, and separation of the serum from the whole cells may be achieved by centrifuging the sample within that -~
' contalnerg or wlthin another container to which the sample has .i ~ Oeen transferred. Thereafter, the serum is commonly poured off ~1~ 20~ into yet another container for the desired clinical testing.
All such transfer operations are time consuming, requiring either hand.prccessing or complicated, expensive automatic handling. Furthermore, whenever the~e is a transfer of a ;
liquid sample to a separate~ open container, the sample is aerated~and C02 loss or galn can occur. There is also the danger of~improper transfer, either by the use of the wrong container, by the improper patient labeling of the new con-tainer, or by both. Still further, contamination of the serum by foreign materials or ~in~ection of the operator can occur.
Reuse of the same dispensing device for sequential samples requires careful sterili~ation to a-oid contamination. Thus, a ¦~
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; tem which keeps ~he ~lood sample conrined to essentially one container from its collection to the actual dispensing for analysis is a distinct, sought~after improvement.
~t the centrifuging stage~ a variety of means have been provided for more or less plugging the serum-cell interface ;
that is formed during centrifuging, whereby remixing of the cells and serum is prevented. U.S. Patent Nos. 3,647,070;
3,779,383; 3,780,935; 3,800,947; 3,849,072 and 3,850,174 are representative o~ devices of this nature. The disclosures of U.S. Patent Nos. 3,647,070; 3,779,383; 3,800,947 and 3,849,072 are typical of mechanical valve devices which prevent flow -across the interfase. Such devices~ however~ are quite com~li-cated, resulting in increased cost of manufacture. Furthermorè, they are susceptible to mechanical failure and do not automatically seek out the serum-cell interface. Devices such as are shown in U.S. Patent No. 3,779,383 are not provided with valve means at the serum end to permit ready removal of the serum. Instead, the plug must be removed and the serum either poured off, as by tilting the container, or it must be aspirated or otherwise ~j 20~ drawn off.
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~ ~ Of the many devices available to provide blood serum -.i .
for analysis, the one which has become the norm is the evacuated conta-iner. Thls is slmply a~part1allD evacuated glass tube open ` at one end except for a septum placed there. One improvement over such an evacuated container which is particularly useful comprises a ~lass tube open only at-one end, a septum affixed to~ ~
that end when the tube is evacuated, and a movable plug contained ;;
within the tube. The plug is preferably a silica gel, with or withouk a plastic cup-like mandrel positioned with its open end pointed to the septum. By reason of the vacuum, collected blood ., . . .
is easily drawn into the container. The container is then spun about a centrifuge axis adJacent to the septum end, and the gel by reason of its selected specific gravity works up to the -3- :
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5~;)5C19 serum-cell interface where it plugs the container against remixing of the serum and cells. An example of such a con-tainer but without the mandrel is shown in U.S. Patent No.
3,852,194.
Although such a de~ice is useful in separating the - serum from the cells, it has not avoided the transfer difficul-ties noted above. Furthermore, b~ pouring out the serum through the theretofore septum-plugged end, it is possible to contaminate the serum with blood cells which collected at the 10 septum-container interface prior to centrifuging, a condition ` known as "blood-ring contamination".
Commonly-owned U.S. Patent No. 3,977,5~8 by David S.
Smith, entitled "Biological Fluid Dispenser for Dispensing Micro Amounts", discloses dispensing devices which can be added to a serum container of any type, and which feature a dispensing chamber having a drop-forming platform, and a value ~ for temporarily blocking flow of serum into the chamber. The 3 values disclosed include a shear value, and in each case the ~-~ value seat and closure member are disclosed as being separate 20 from the serum container and the dispensing chamber~ -Commonly-owned U.S. Patent No. 4,012,325 by Richard L. ~ -~i Columbus, entitled "Biological Fluid Dispenser and Separator", ,! ~ discloses an improved serum separator in which a dispensing portion can be an integral or added part. In that separator, both of the opposite ends of the separation compartment are accessible, permitting the serum to be drawn off at the end J opposite to the blood intake end so as to provide a number of superior advantages when the separator is used with a phase-separating gel. To dispense serum, the device features a 30 chamber, a drop-forming platform3 and a blocking means such as a ,, ", . ' '
:, : . ~, , .
~ ~ Of the many devices available to provide blood serum -.i .
for analysis, the one which has become the norm is the evacuated conta-iner. Thls is slmply a~part1allD evacuated glass tube open ` at one end except for a septum placed there. One improvement over such an evacuated container which is particularly useful comprises a ~lass tube open only at-one end, a septum affixed to~ ~
that end when the tube is evacuated, and a movable plug contained ;;
within the tube. The plug is preferably a silica gel, with or withouk a plastic cup-like mandrel positioned with its open end pointed to the septum. By reason of the vacuum, collected blood ., . . .
is easily drawn into the container. The container is then spun about a centrifuge axis adJacent to the septum end, and the gel by reason of its selected specific gravity works up to the -3- :
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5~;)5C19 serum-cell interface where it plugs the container against remixing of the serum and cells. An example of such a con-tainer but without the mandrel is shown in U.S. Patent No.
3,852,194.
Although such a de~ice is useful in separating the - serum from the cells, it has not avoided the transfer difficul-ties noted above. Furthermore, b~ pouring out the serum through the theretofore septum-plugged end, it is possible to contaminate the serum with blood cells which collected at the 10 septum-container interface prior to centrifuging, a condition ` known as "blood-ring contamination".
Commonly-owned U.S. Patent No. 3,977,5~8 by David S.
Smith, entitled "Biological Fluid Dispenser for Dispensing Micro Amounts", discloses dispensing devices which can be added to a serum container of any type, and which feature a dispensing chamber having a drop-forming platform, and a value ~ for temporarily blocking flow of serum into the chamber. The 3 values disclosed include a shear value, and in each case the ~-~ value seat and closure member are disclosed as being separate 20 from the serum container and the dispensing chamber~ -Commonly-owned U.S. Patent No. 4,012,325 by Richard L. ~ -~i Columbus, entitled "Biological Fluid Dispenser and Separator", ,! ~ discloses an improved serum separator in which a dispensing portion can be an integral or added part. In that separator, both of the opposite ends of the separation compartment are accessible, permitting the serum to be drawn off at the end J opposite to the blood intake end so as to provide a number of superior advantages when the separator is used with a phase-separating gel. To dispense serum, the device features a 30 chamber, a drop-forming platform3 and a blocking means such as a ,, ", . ' '
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1~5~509 valve, positioned between the serum-separation compartment and the platform. As in the Smith patent, the blocking means is a separate part. In one embodiment, the phase-separating gel is used to complete the enclosed, pressurized con~ines ~or the serum during the dispensing stage. In that embodiment, a separate, rotating value mounted within the dispensing chamber is used prior to dispensing to block the apertures in the side walls of the dispensing chamber.
Although the devices o~ the Columbus patent have provided significant improvements over previous designs, they have been more dif~icult to seal if an evacuated mode, as - opposed to a vented mode, of blood intake is used, due in part to the value disposed at the serum outlet end. Such values, while functioning well as a liquid control, are not as effective . . .
'! in preventing air leakage into the evacuated serum separation portion of the container, particularly when the containers must be stored in such an evacuated condition for long periods.
Obher patents relating to blood serum separation in general are U.S. Patent Nos. 3,645,253; 3,687,296; 3,706,305;
-i^3 20 3,706,606; and 3,771,965. Some of these, while not relying on -a plug to providé a barrier between se~um and cells, use a filter to separate ser D from the blood cells.
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SUMMARY OF THE INVENTION
This invention concerns a blood handling device for separating and dispensing blood serum, wherein the dispensing portion and the separating portion themselves provide, relative to each other, a valve for preventing premature flow of serum from one to the other. More speci-fically, in accordance with one aspect of the invention there is provided a blood serum dispensing device, comprising two containers movably mounted one within the other, one of the containers being a compartment having opposed ends, one end belng open for fluid communication with respect to the other container, the other container comprising an end wall, and opposed side walls extending from one surface of the end wall and encompassing at least the open end of the one container;
at least one of the opposed walls being provided with an ~ ' 1 .
... aperture capable of providing fluid communication into or out of the other container from the exterior surface thereof; the end wall of the other container being removably sealed against the open end of the one container to prevent fluid flow : "
therefrom, and the aperture being removably blocked from ., fluid communication with the one container, by the one container;
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~ and further including means for sealing together the opposed - walls and the open end of the one container when the other ~`~ container end wall is pulled away from the open end, so as 1 to permit fluid flow from the open end to the aperture.
In accord with another:aspect of the invention i there is provided a dispensing container for use with a blood serum separation device whioh includes a separation compartment -g open at at leas'c one end of the compartment; the container comprising ':
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a generally cylindrical dispensing chamber having an end wall and a platform at one side thereof suitable for the formation of drops;
said platform having an aperture in fluid communi-cation with said chamber, the maximum dimension of the - aperture being sufficiently small as to prevent flow of the serum under gravity;
a passageway capable of fluidly connecting the separation compartment to the chamber;
and means for slidably moving said container between two sealed positions which encompass the open end of the compartment, one of said positions being such as to locate ~'` said aperture in alignment with the walls of the compartment so as to block fluid flow out of the aperture, and the other of said positions being such as to ].ocate said aperture free .:.~
`` ~ of any blocking surface;
said container being free of a separate movable valve mounted within said chamber.
~' BRIEF DESCRIPTION OF THE DRAWINGS
:~"! 20 Fig. 1 is a sectional view along the axis of a; ~ serum separator and dispenser device constructed in accor-dance with the invention; ~ -Fig. 2 is an enlarged, fragmentary sectional view ., :~ similar to that of Fig. 1, but illustrating the dispensing portion in its extended position with a pressurizing means uxtaposed;
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Fig. 3 is a sectional view taken generally along the line III-III o~ Fig. l;
Fig. 4 is a fragmentary sectional view similar to that of Fig. 1, but illustrating an alternate embodiment;
Fig. 5 is a view similar to that of Fig. 4, except that the dispensing portion is shown in its expanded, dispensing position, a further modification being illustrated in phantom;
Fig. 6 is a sectional view similar to that of Fig. 1, ~ but illustrating yet another embodiment, - 10 Fig. 7 is a fragmentary sectional view similar to , ~ .
; that of Fig. 2, but illustrating the embodiment of Fig. 6; and -Fig. 8 is a sectional view similar to Fig. 3, but ;~` illustrating still another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
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! ~ The invention is intended for use in the dispensing of blood sera directly from blood separators onto suitable substrates, for clinical analysis. Typical of such substrates ~;! are those shown, for example, in commonly owned U.S. Patent No. 3,992,158 entitled "Integral Analytical Element", by . ..................................................................... .... .
E. Przybylowicz et al. However, the apparatus of this inven-` tion is neither limited to use with just such substrates, nor to just the dispensing of drops o~ blood sera. Other fluids capable of being dispensed can also be handled by this apparatus. -3 As used in this application, terms such as "up" and -1 "down' refer to the orientation of the disclosed parts during . j . . .
~ their actual use, in reference to the direction of the force ;-: ~ . -~ of gravity.
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As illustrated in Fig. 1, a separation and dispensing 3 device 10 constructed in accordance with the invention preferably ~, comprises two generally elongated containers 12 and 30 movably mounted, and specifically telescoped, one with respect to the ~, _7_ ` ', . ' .
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other. Together the containers themselves ~orm a value which is closed when in the position o~ Fig. 1~ but which is open when in the position shown in Fig. 2. Container 12 is the serum-separation portion or compartment, while container 30 is the dispensing portion that ~orms a dispensing chamber when moved to the position shown in Fig. 2.
` Considering first container 12, it comprises a ; generally tubular wall 14 comprised of any suitable material andof any convenient shape such~as can be achieved by opposed walls arranged about an axis 16 to define a blood separation compart-ment accessible at both ends 18 and 20, a closure means 22 such as a septum secured to end 18, which end serves as a blood inlet for the blood collection stage, and a movable plug 24 pre~erably comprising a silica gel which can be a blend of -;
hydrophobic silicon dioxide and a silicone, such as dimethyl-.,~ .
polysiloxane, blended to give a thioxtropic gel having a speci~ic gravity between about 1.035 and 1.06, and pre~erably about 1.04-1.05, and a viscosity between about 400 and about ~ -~
500 poise at a shear rate of about 500 sec. 1, and typically 451 poise at 506 sec. . The gel can be used by itsel~ without a mandrel~ as is taught for example in the aforesaid U.S.
Patent No. 3,852,194, or with a mandrel as manu~actured for example by Corning Glass Works. End 20 can be provided witA a 1 rim 26 protruding outwardly away from the walls 14, Flg. 2, i primarily for sealing that end with respect to the interior of ` container 30, as is described hereinafter.
As disclosed in the a~oresaid patent of Columbus, ;
such a construction o~ container 12 permits a centrifugal force Fig. 1~ to be applied towards the septum end 18 by spinning the device about a point o~ rotation positioned ad~acent end 20. The portion distal to end 20 becomes the cell-collecting portion o~ ~
the compartment, and the portion proximal or adjacent to ;
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i 20 becomes the serum-collecting portion. The gel 24 thus is initially positioned in the serum-collecting portion, where it assists container 20 in closing that end off to fluid flow prior to centrifuging, thus permitting partial evacuation of the container. Furthermore, the plug formed by gel 24 serves ; as means for preventing any "blood ring" from forming at the seal formed by container 30 with the end 20, thus preventing "blood ring contamination".
It is not clear what the actual mechanism is for the gel-serum movement, but it is believed that, as soon as a centrifuging force F is applied sufficient to initiate separation . , .
of the serum, the gel moves and permits serum flow towards end -- 20~ due to the specific gravity of serum being lighter than that of the gel. If an imbedded mandrel is used (not shown), the gel has nowhere else to go, except into the mandrel which preferably has an open end directed towards the gel.
After the separation is complete, the flow of the serum past the plug terminates and continued spinning causes the mass of the gel 24 to spread back into contact with the wall of container 12j Fig. 2~ completing the sealing arrangement.
By this means, gel 24 acts to maintain the separation of the two portions of the whole blood.
Plastic beads (not shown) can be used as a gel extender in lieu of the mandrel. The beads and/or mandrel move with the gel during centrifuging.
Referring now to Fig. 2 in particular, container 30 comprises an end wall 32 having~an interior side or surface 34 and an exterior side or surface 36 ~ an~ opposed side walls 38 extending from side 34~ terminating at an opposite end 40 of i the container 30. The side walls 38 accommodate or encompass end 20 of the container 12, so that end 20 is movably mounted - and specifically telescoped within end 40 of container 30~
Preferably, the opposed walls 38 are arranged about an axis which is coincident with axis 16. Thus, as with container 12, the wall~ 38 can have a shape in which the walls form _9_ 1 .
1~51)5a~9 one continuous wall.
The walls 38 have an interior surface 42 and an exterior surface 43. The interior surface 42 can be cylindrical while the exterior surface 43 can be rectilinear (Fig. 3) .
Between the interior surfaces is the interior of the container 300 That interior is temporarily blocked from fluid flow of serum from end 20 of container 12 by virtue of the removable seal formed by side 34 of end wall 32 positioned against end 20. Interior surface 42 is further provided with means for 10 sealing the interior of end 40 of container 30 against end 20 when that end has been unblocked by opposite end wall 32, ` and for slidably moving the container 30 to that unblocked position. The means permitting the mo~ement of container 30 s .; `: -'A to the two positions is the approximate coincidence of the , interior diameter of surfa~e 42 of container 30 and the exterior ~-diameter of walls 14. Flexibility of walls 42 permit the rîm ; 26 to ride across the surface of wal]s 42. A preferred form ~ ;of the sealing means in the unblocked positioning of container 30 is a groove 44 extending around the entire circumference of interior surface 42, shaped to mate with rim 26 of end 20.
If desired, an 0-ring 46 can be seated within the groove 44 to ~ assist in the sealing. A similar construction can be given to -j the junction of side walls 38 with end wall 32, so as to form a groove 48 with an 0-ring 49 seated therein.
~; Preferably, two apertures 50 and 70 are formed in 1 portions 52 and 72, respectively, of the side walls 38, for the dispensing operation depicted in Fig. 2. These apertures - -1 preferably are constructed in the manner disclosed in the ! aforesaid Columbus patent. Specifically, the portion 52 30 of the side wall 38 has a specially-constructed drop-forming plat~orm 54 isolated from the rest o~ the exterior :.;3;~ 10~
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~ rac~ 43 ~y (~ connect;Lng port:lon or surrace 56, and sllr-rounded by a protruding shoulder 57. Aperture 50 has an exit portlon which is centered within the platform 5ll, and an entrance portion 58 in interior surface-42 of portion 52.
By virtue of the connecting surface or portion 56, a second .enlarged aperture 60 is formed, separating aperture 50 from thé rest of the chamber 30.
The function of the platform 54 and aperture 50 is to :
accurately form successive drops of predictable and uniform volume, each of whlch-is to be touched off on a suitable substrate. To ~: ' ' . ' . ` ' ' . ' ` .
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provide this function with a fluid having such drasticaIly varying properties as blood serum, certain features have been found to be useful. As disclosed in ~he aforesaid Columbus application, there preferably is a vertical separation of the platform 54 from the surface 43 by a distance "h", and a horizontal separation from shoulders 57 by a minimum width "w".
Both of these preferably are such as to prevent a drop of blood - serum from spreading from the platform to the remaining chamber ; portions prior to drop transfer. Such drop spreading would - 10 interfere with accurate drop transfer. It has been found that a suitable value for the height "h" is about 0.127 cm, while width "w" should be at least about 0.05 cm, and preferably about 0.127 ~
cm. Furthermore, the surface of the walls immediately adjacent ~ -to platform 54, that is the connecting surface 56, preferably . slopes away from a line 62 along which the force of gravity acts :
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when the drop is formed, by an angle which is between about 0 and about 15 degrees. Negative angles are also usable~ Any slope greater than this will encourage the drop to cli~b up and ~ contact exterior surface 43, thus interfering with the ,,f ~ 20 proper drop size and drop removaI.
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To further lnsure that blood serum of the types commonly received from patlents are properly dispensed as a drop from platform 54, in accurate micro-amounts, the-following additional properties are desirable. . .
1) Aperture 50 preferably has a maximum dimension at the exterior surface of platform 54, measured transversely to fluid flow therethrough, which is less than that whioh will permit~flow of blood serum under the influence of gravity and which is large enough to retard closure of the aperture by protein agglomeration. To perform this function with blood sera having a surface tension of between about 35 dynes/cm and about 75 dynes/cm, it has been found that the maximum dimension should be between about 0. 02~ and about 0. o46 cm. This dimen-sional range appears to be operative even when the relative . . : : .
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s~s~ 3 ~.scosity is as low as about 1.2 centipoises and is as high or higher than about 2 centipoises. The upper value can be increased if the head of fluid is correspondingly decreased as would be the case if the dimensions of the intérior of container 30 were increased. A typical head of fluid for such a maximum aperture dimension is 2.29 cm. A particularly useful embodiment is one in which the aperture is generally circular in shape, wlth the circle diameter being 0.038 cm. i 2) It is also preferred that the intersection of the 10 aperture 50 with the platform surface be essentially a sharp ~ I
edge, i.e., having a radius of curvature no greater than about ¦~ :
0.02 cm. Further, the platform should be free of protrusions such as portions of flashing, which would pro~ect either away from the platform or into the fluid passageway. Without such precision in the formation of the aperture, capillary effects would be increased, tending to cause prernature fluid flow.
3) The transition zone between platform 54 and the ;
connecting surface 56 defines an edge 64 which preferably is sufficiently sharp as to prevent the tendency of the serum drop Z0 to climb up the surface 56 under the influence of surfacè
tension. For the range of fluids anticipated, it is preferred that the maxlmum radius of curvature to achievè such an effect does not exceed about 0.02 cm, The effect of the preced~ing features is to confine the drop dispen`sed from the container 30~to the surface of the plat-:~ form 54. It will be appreciated that the entire surface of thep1atform is eontacted by the drop~, and because the drop naturally assumes a quasi-spherical form, the contacted surface area of the ¦
platform will range from about 0.0026 sq. cm. for a 1 ~1 drop, to 3 about 0.018 sq. cm. for a 30 ~1 drop. This represents a range in platform diameter, between edges 64, which is between about 0.05 cm and about 0.15 cm. Alternatively, the surface area ~
supporting, and in contact with, the drop can be increased for ~-,. . ' .,:,: ~
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5QSa3~ t a given drop volume and platform diameter by either 1) forming a downwardly projecting rim around edge 64, 2) making the plat-form surface concave, or 3) roughening the surface of platform 54. Without such roughening, it has been ~ound that a preferred surface smoothness is between about ] to 30 RMS.
To assist in drop detachment and to minimize protein agglomeration in aperture 50, the platform 54 preferably has a cross-sectional thickness from surface 42 to surface 43, measured along a plane extending perpendicular through the platform, which lO is no greater than about 0.025 cm. A particularly useful thick-ness is about 0.013 cm. The effect of such a construction is to minimize the neck of fluid connecting the drop to the main volume ;
in container 30. This in turn permits rapid detachment with ! little secondary flow out of the container.
All of the above features can be obtained by forming ` the container 30 out of copolymers such as acrylonitrile-~,~ butadiene-stryene (ABS), and polymers such as poly(acetal), poly-~propylene), poly(styrene), high density poly(ethylene), and poly-; esters.
- 20 Aperture 70 in portion 72 of si.de walls 38 is preferably ; ~ ~ positioned opposite the aperture 50, and need otherwise be ; construc~ed only as a passageway for ~ressurized ~as generated J ~ exterior to-the container. ~
The dispensing operation i.9 achieved after the centri-fugal separation of the serum, by sliding the container 30 so ~hat end wall 32 no longer blocks end 20 of container l2, Fig. 2, and rim 26 is seated in groove 44 instead of groove 48. The serum is then free to flow into the dispensing chamber and into aperture 50. The dispensing chamber now comprises, in this ~ 3 expanded position, the end wall 32, side walls 38, the ~el 24 i sealing off the cell-portion Or the blood, and the side walls -14 of the serum-collecting portion of container 12, including end 20.
A suitable pressurizing means 80 can be used such as an air hose or a .' ' . ' ' '. '~
~ 050509 collapsible bellows such as is shown in commonl~-owned U.S~
Patent No. 4,041,995 by Richard L. Columbus. By properly increasing the pressure of the interior of container 14 by an amount just necessary to form a 10 ~1 drop, the drop will ~orm as shown in Fig. 2. A suitable support can be used to hold the device during drop dispensing.
To insure that proper drop formation of predictable volume occurs the first time for a given pressure increase resulting from means 80, the total air volume about the serum surface should be minimized. Such a feature can be particularly significant where, as here, the air volume is increased dras-tically before dispensing can be achieved. It has been found that when the air volume above the serum in the dispensing chamber opened to the extended position is about 1300 ~1, for example~ no problem occurs in accurate dispensing. A typical ,1 .
example of dimensions for containers 12 and 30 which provide ` this volume is one in which container 20 has an internal ~i diameter of about o.85 cm between walls 14 and gel 24 is located about 3.6 cm from end 20, and containe~ 30 has an internal diameter between interior surfaces 42-of about 1.05 cm ~, ~ and a separation between grooves 44 and 48 of about 0.7 cm.
In such a case, a typical amount of serum to be dispensed is about 1360 ~1. The above-noted location of the gel occurs when a 50% gel separation occurs upon centrifuglng of an 80% filled container 12 having an exterior length of about 7 cm. ~ -. ,~ ~. .
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As reported in the aforesaid Columbus Patent No.
4,041,995, it has been found that a container 30 constructed as described above, when the contents are appropriately pressurized, repeatedly will give uniform volumetric drops of biological ~luids, such as blood sera, even when the relative viscosityg surface tension and total protein content vary -drastically as is characteristic of blood sera drawn from diseased as well as healthy pat~ents. The coefficient of variation as is commonly used in statistical analysis has been found to be no greater than about 2~ from the mean, thus - insuring that repeated drops have about the same volume. This - -accuracy is achieved not only for blood serum, but also for other biological fluids such as Ringer solutions and water.
It will thus be appreciated that containers 12 and 30 cooperate together to form a shear value, in which the contracted or closed position of container 30, Fig. 1, results in apertures 50 and 70 being blocked by the serum-collecting portion of container 12, from fluid communication with end 20 of container 12. This is done without requiring a separate value part. Serum flow is permitted, however, by sliding the two containers apart into the extended position shown in Fig. 2.
Because the contracted position provides a completely telescoped fit of the two containers, the volume of the device in its serum-separation configuration is essentially the minlmum, i.e.
only the amount needed for the serum separation function.
A further advantage of the invention is that a substantial seal is provided by end wall 32 against end 20, sufficient even to maintain a partial vacuum as is customary . . . .
in serum-collecting devices. Such a vacuum seal can be maintained e~en when container 12 is glass and container 30 is plastic, -- :
for example. Thus, the device of this invention -14a-''':
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,v:Ldes a superior blood collecting device.
In addition to the glass and plastic embodiments shown, both containers can be made of other materials such as plastic, in which case the rim 26 on container 12 can be trans-ferred to container 30 at end 40 to fit into a notch (not shown)-in container 12 when the containers are telescoped together as in Fig. 1. When container 30 is moved to its expanded pressurizable position, an additional notch can be provided for the rim, or alternatively, the rim bearing against the walls 14 of container 12 provides adequate sealing during the dispensing operation.
Turning now to Figs. 4 and 5, there is illustrated an alternate embodiment wherein the relative movable mounting of the two containers is achieved by means of a screw-- thread. Parts similar to those previously described bear -the same reference number to which the distinguishing suffix "a" has been added. Thus, the separation and dispensing device comprises a tubular wall 14a openable at two opposite . ~
ends, defining a serum separation compartment~ and a dispensing ' ~ portion or chamber 30a movably mounted with respect to, and ^l 20 encompassing end 20a of the container 12a, as in the previous embodiment. Also as before, end wall 32a is removably sealed against end 20a o~ the container; and, prior to centrifuging, a gel plug 24a is located in the serum-collecting portion of container 12a which is proximal to end 20a.
However, the relative movement between the two i containers from their closed position, Fig. 4, to the extended position used in dispensing, Fig. 5, is achieved by means of a male threaded portion 90 at end 20a of container 12a, and .~, . .
a female-threaded portion 92 formed in the interior surface 42a the length of the opposed walls 38a. By unscrewing container 30a, the aperture 50a, constructed as before with a platform ~
54a, becomes unbloc~ed by end 20a, so that the serum can flow -from that end to the aperture. A further possible modification is a pour-off nozzle 100 bearing a screw-cap 102, shown in ' :
.
antom. :[n this embodiment, the capped pour-off nozzle 100 acts as an extension of end wa]l 32a in that it still permits the maintenance of a vacuum seal agalnst end 20a and prevents serum flow to aperture 50a, when in the contracted or closed configuration shown in Fig. 1.
' Dispensing in any case is achieved by means of a pressurizing device 80a as in the description of the embodi-ment of Fig. 1.
Turning now to Figs. 6 and 7, still another embodiment is illustrated wherein the blood inlet end coincides with the dispensing chamber, as must be the case when a single-ended tube -is used. Parts similar to those previously described bear the ' same reference numeral to which the distinguishing suffix "b" is appended. Thus, the separation compartment is a container 12b the walls 14b of which close upon themselves at end 18b~ such as in the device shown in U.S. Patent No.
sll ~ 3,852,194. The gel plug 24b in this case must be located, '' prior to centrifuging, in the cell-collecting portion of the ~, compartment which is distal to end 20b. Container 30b is `'' 1, 20~ const~ructed substantially identically as in the embodiment shown in Fig. 1, except that end wall 32b includes at least ; a~portion 110 which ls a flexible elastomer or a rigid synthetic `
plastic capable of penetration by a cannula to permit blood '~
' intake. Thus, portion 110 functlons as a septum, and any ' self-se~aling natural or synthetic elastomer or plastic suffices, such as~butyl rubber. By beveling portion 110 at the juncture :
of inner surface 34b with slde walls 38b, Fig. 7, an annular groove 112 for receiving end 20b in sealed relationship is formed, Fig. 6. The seal permits container 12b to be evacuated, 30 the vacuum of which is used to draw in blood when a cannula ~ ' I is pushed through p.ortion 110 whlle end wall 32b otherwise seals end 20b. 'Alternatively, the blood can be added to container 12b as shown in the above-noted patent No. 3,852,194, and the i'~
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~ `ntainer 30b can be then mounted over container 12b for the .. , , centrifuge step and dispensing as described hereafter. The flexible portion 110 in such a case serves as an adequate stopper for the centrifuging step.
Side walls 38b preferably are provided, as in Fig. 2, with a groove 44b~ and optionally, a groove 48b and 0-ring 49b, to receive rim 26 of end 20b. Alternatively, groove 48b can be formed entirely within end wall 32b, such as by molding, and portion 110 can be of reduced diameter such that portion 110 does not take part in the sealing of end 20b to end wall 32b.
Dispensing is achieved as described concerning Fig. 1, by sliding container 30b to its expanded position, Fig. 7, thus opening the shear valve to permit flow of serum to aperture 50b unblocked by the sliding motion. The dispensing ohamber so formed again includes the gel 24b re-positioned transversely across container 12b to seal the serum from the - ~ ¦~
, cellular portion of the blood. -¦ As in the embodiment of Fig. 1, ~he telescoping of ¦
the two oontainers 12b and 30b can be achieved by a screw thread~as shown in the embodiment of Fig. 4.
Pig. 8 illustrates a further modlfication wherein the walls of the separation compartment are no longer cylin-drical. Similar parts bear the same reference numerals with '~ a suffix;"c". Thus, the containers 12c and 30c are formed 1 .
and function together as described above for the embodiment of Figs. l or 6, except that opposed walls 14c form a 4-sided, preferably right-angled tube, to which the interior surface 42c of walls 38c are matched, to illustrate that other shapes of container 12 are contemplated.
In all of the preceding embodiments, it w111 bè -appreciated that the container 30 used for dispensing can be added onto a conventional vessel containing serum, :. . ..
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S1~5~9 separated in any manner from blood cells, for dispensing the serum in the manner of the invention. For example, container 12 can be a container available under the trademark "Corvac"
from Corning Glass Works, to which container 30 is added after the sample has been centrifuged.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
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1~5~509 valve, positioned between the serum-separation compartment and the platform. As in the Smith patent, the blocking means is a separate part. In one embodiment, the phase-separating gel is used to complete the enclosed, pressurized con~ines ~or the serum during the dispensing stage. In that embodiment, a separate, rotating value mounted within the dispensing chamber is used prior to dispensing to block the apertures in the side walls of the dispensing chamber.
Although the devices o~ the Columbus patent have provided significant improvements over previous designs, they have been more dif~icult to seal if an evacuated mode, as - opposed to a vented mode, of blood intake is used, due in part to the value disposed at the serum outlet end. Such values, while functioning well as a liquid control, are not as effective . . .
'! in preventing air leakage into the evacuated serum separation portion of the container, particularly when the containers must be stored in such an evacuated condition for long periods.
Obher patents relating to blood serum separation in general are U.S. Patent Nos. 3,645,253; 3,687,296; 3,706,305;
-i^3 20 3,706,606; and 3,771,965. Some of these, while not relying on -a plug to providé a barrier between se~um and cells, use a filter to separate ser D from the blood cells.
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SUMMARY OF THE INVENTION
This invention concerns a blood handling device for separating and dispensing blood serum, wherein the dispensing portion and the separating portion themselves provide, relative to each other, a valve for preventing premature flow of serum from one to the other. More speci-fically, in accordance with one aspect of the invention there is provided a blood serum dispensing device, comprising two containers movably mounted one within the other, one of the containers being a compartment having opposed ends, one end belng open for fluid communication with respect to the other container, the other container comprising an end wall, and opposed side walls extending from one surface of the end wall and encompassing at least the open end of the one container;
at least one of the opposed walls being provided with an ~ ' 1 .
... aperture capable of providing fluid communication into or out of the other container from the exterior surface thereof; the end wall of the other container being removably sealed against the open end of the one container to prevent fluid flow : "
therefrom, and the aperture being removably blocked from ., fluid communication with the one container, by the one container;
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~ and further including means for sealing together the opposed - walls and the open end of the one container when the other ~`~ container end wall is pulled away from the open end, so as 1 to permit fluid flow from the open end to the aperture.
In accord with another:aspect of the invention i there is provided a dispensing container for use with a blood serum separation device whioh includes a separation compartment -g open at at leas'c one end of the compartment; the container comprising ':
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a generally cylindrical dispensing chamber having an end wall and a platform at one side thereof suitable for the formation of drops;
said platform having an aperture in fluid communi-cation with said chamber, the maximum dimension of the - aperture being sufficiently small as to prevent flow of the serum under gravity;
a passageway capable of fluidly connecting the separation compartment to the chamber;
and means for slidably moving said container between two sealed positions which encompass the open end of the compartment, one of said positions being such as to locate ~'` said aperture in alignment with the walls of the compartment so as to block fluid flow out of the aperture, and the other of said positions being such as to ].ocate said aperture free .:.~
`` ~ of any blocking surface;
said container being free of a separate movable valve mounted within said chamber.
~' BRIEF DESCRIPTION OF THE DRAWINGS
:~"! 20 Fig. 1 is a sectional view along the axis of a; ~ serum separator and dispenser device constructed in accor-dance with the invention; ~ -Fig. 2 is an enlarged, fragmentary sectional view ., :~ similar to that of Fig. 1, but illustrating the dispensing portion in its extended position with a pressurizing means uxtaposed;
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Fig. 3 is a sectional view taken generally along the line III-III o~ Fig. l;
Fig. 4 is a fragmentary sectional view similar to that of Fig. 1, but illustrating an alternate embodiment;
Fig. 5 is a view similar to that of Fig. 4, except that the dispensing portion is shown in its expanded, dispensing position, a further modification being illustrated in phantom;
Fig. 6 is a sectional view similar to that of Fig. 1, ~ but illustrating yet another embodiment, - 10 Fig. 7 is a fragmentary sectional view similar to , ~ .
; that of Fig. 2, but illustrating the embodiment of Fig. 6; and -Fig. 8 is a sectional view similar to Fig. 3, but ;~` illustrating still another embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
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! ~ The invention is intended for use in the dispensing of blood sera directly from blood separators onto suitable substrates, for clinical analysis. Typical of such substrates ~;! are those shown, for example, in commonly owned U.S. Patent No. 3,992,158 entitled "Integral Analytical Element", by . ..................................................................... .... .
E. Przybylowicz et al. However, the apparatus of this inven-` tion is neither limited to use with just such substrates, nor to just the dispensing of drops o~ blood sera. Other fluids capable of being dispensed can also be handled by this apparatus. -3 As used in this application, terms such as "up" and -1 "down' refer to the orientation of the disclosed parts during . j . . .
~ their actual use, in reference to the direction of the force ;-: ~ . -~ of gravity.
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As illustrated in Fig. 1, a separation and dispensing 3 device 10 constructed in accordance with the invention preferably ~, comprises two generally elongated containers 12 and 30 movably mounted, and specifically telescoped, one with respect to the ~, _7_ ` ', . ' .
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other. Together the containers themselves ~orm a value which is closed when in the position o~ Fig. 1~ but which is open when in the position shown in Fig. 2. Container 12 is the serum-separation portion or compartment, while container 30 is the dispensing portion that ~orms a dispensing chamber when moved to the position shown in Fig. 2.
` Considering first container 12, it comprises a ; generally tubular wall 14 comprised of any suitable material andof any convenient shape such~as can be achieved by opposed walls arranged about an axis 16 to define a blood separation compart-ment accessible at both ends 18 and 20, a closure means 22 such as a septum secured to end 18, which end serves as a blood inlet for the blood collection stage, and a movable plug 24 pre~erably comprising a silica gel which can be a blend of -;
hydrophobic silicon dioxide and a silicone, such as dimethyl-.,~ .
polysiloxane, blended to give a thioxtropic gel having a speci~ic gravity between about 1.035 and 1.06, and pre~erably about 1.04-1.05, and a viscosity between about 400 and about ~ -~
500 poise at a shear rate of about 500 sec. 1, and typically 451 poise at 506 sec. . The gel can be used by itsel~ without a mandrel~ as is taught for example in the aforesaid U.S.
Patent No. 3,852,194, or with a mandrel as manu~actured for example by Corning Glass Works. End 20 can be provided witA a 1 rim 26 protruding outwardly away from the walls 14, Flg. 2, i primarily for sealing that end with respect to the interior of ` container 30, as is described hereinafter.
As disclosed in the a~oresaid patent of Columbus, ;
such a construction o~ container 12 permits a centrifugal force Fig. 1~ to be applied towards the septum end 18 by spinning the device about a point o~ rotation positioned ad~acent end 20. The portion distal to end 20 becomes the cell-collecting portion o~ ~
the compartment, and the portion proximal or adjacent to ;
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i 20 becomes the serum-collecting portion. The gel 24 thus is initially positioned in the serum-collecting portion, where it assists container 20 in closing that end off to fluid flow prior to centrifuging, thus permitting partial evacuation of the container. Furthermore, the plug formed by gel 24 serves ; as means for preventing any "blood ring" from forming at the seal formed by container 30 with the end 20, thus preventing "blood ring contamination".
It is not clear what the actual mechanism is for the gel-serum movement, but it is believed that, as soon as a centrifuging force F is applied sufficient to initiate separation . , .
of the serum, the gel moves and permits serum flow towards end -- 20~ due to the specific gravity of serum being lighter than that of the gel. If an imbedded mandrel is used (not shown), the gel has nowhere else to go, except into the mandrel which preferably has an open end directed towards the gel.
After the separation is complete, the flow of the serum past the plug terminates and continued spinning causes the mass of the gel 24 to spread back into contact with the wall of container 12j Fig. 2~ completing the sealing arrangement.
By this means, gel 24 acts to maintain the separation of the two portions of the whole blood.
Plastic beads (not shown) can be used as a gel extender in lieu of the mandrel. The beads and/or mandrel move with the gel during centrifuging.
Referring now to Fig. 2 in particular, container 30 comprises an end wall 32 having~an interior side or surface 34 and an exterior side or surface 36 ~ an~ opposed side walls 38 extending from side 34~ terminating at an opposite end 40 of i the container 30. The side walls 38 accommodate or encompass end 20 of the container 12, so that end 20 is movably mounted - and specifically telescoped within end 40 of container 30~
Preferably, the opposed walls 38 are arranged about an axis which is coincident with axis 16. Thus, as with container 12, the wall~ 38 can have a shape in which the walls form _9_ 1 .
1~51)5a~9 one continuous wall.
The walls 38 have an interior surface 42 and an exterior surface 43. The interior surface 42 can be cylindrical while the exterior surface 43 can be rectilinear (Fig. 3) .
Between the interior surfaces is the interior of the container 300 That interior is temporarily blocked from fluid flow of serum from end 20 of container 12 by virtue of the removable seal formed by side 34 of end wall 32 positioned against end 20. Interior surface 42 is further provided with means for 10 sealing the interior of end 40 of container 30 against end 20 when that end has been unblocked by opposite end wall 32, ` and for slidably moving the container 30 to that unblocked position. The means permitting the mo~ement of container 30 s .; `: -'A to the two positions is the approximate coincidence of the , interior diameter of surfa~e 42 of container 30 and the exterior ~-diameter of walls 14. Flexibility of walls 42 permit the rîm ; 26 to ride across the surface of wal]s 42. A preferred form ~ ;of the sealing means in the unblocked positioning of container 30 is a groove 44 extending around the entire circumference of interior surface 42, shaped to mate with rim 26 of end 20.
If desired, an 0-ring 46 can be seated within the groove 44 to ~ assist in the sealing. A similar construction can be given to -j the junction of side walls 38 with end wall 32, so as to form a groove 48 with an 0-ring 49 seated therein.
~; Preferably, two apertures 50 and 70 are formed in 1 portions 52 and 72, respectively, of the side walls 38, for the dispensing operation depicted in Fig. 2. These apertures - -1 preferably are constructed in the manner disclosed in the ! aforesaid Columbus patent. Specifically, the portion 52 30 of the side wall 38 has a specially-constructed drop-forming plat~orm 54 isolated from the rest o~ the exterior :.;3;~ 10~
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~ rac~ 43 ~y (~ connect;Lng port:lon or surrace 56, and sllr-rounded by a protruding shoulder 57. Aperture 50 has an exit portlon which is centered within the platform 5ll, and an entrance portion 58 in interior surface-42 of portion 52.
By virtue of the connecting surface or portion 56, a second .enlarged aperture 60 is formed, separating aperture 50 from thé rest of the chamber 30.
The function of the platform 54 and aperture 50 is to :
accurately form successive drops of predictable and uniform volume, each of whlch-is to be touched off on a suitable substrate. To ~: ' ' . ' . ` ' ' . ' ` .
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provide this function with a fluid having such drasticaIly varying properties as blood serum, certain features have been found to be useful. As disclosed in ~he aforesaid Columbus application, there preferably is a vertical separation of the platform 54 from the surface 43 by a distance "h", and a horizontal separation from shoulders 57 by a minimum width "w".
Both of these preferably are such as to prevent a drop of blood - serum from spreading from the platform to the remaining chamber ; portions prior to drop transfer. Such drop spreading would - 10 interfere with accurate drop transfer. It has been found that a suitable value for the height "h" is about 0.127 cm, while width "w" should be at least about 0.05 cm, and preferably about 0.127 ~
cm. Furthermore, the surface of the walls immediately adjacent ~ -to platform 54, that is the connecting surface 56, preferably . slopes away from a line 62 along which the force of gravity acts :
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when the drop is formed, by an angle which is between about 0 and about 15 degrees. Negative angles are also usable~ Any slope greater than this will encourage the drop to cli~b up and ~ contact exterior surface 43, thus interfering with the ,,f ~ 20 proper drop size and drop removaI.
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To further lnsure that blood serum of the types commonly received from patlents are properly dispensed as a drop from platform 54, in accurate micro-amounts, the-following additional properties are desirable. . .
1) Aperture 50 preferably has a maximum dimension at the exterior surface of platform 54, measured transversely to fluid flow therethrough, which is less than that whioh will permit~flow of blood serum under the influence of gravity and which is large enough to retard closure of the aperture by protein agglomeration. To perform this function with blood sera having a surface tension of between about 35 dynes/cm and about 75 dynes/cm, it has been found that the maximum dimension should be between about 0. 02~ and about 0. o46 cm. This dimen-sional range appears to be operative even when the relative . . : : .
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s~s~ 3 ~.scosity is as low as about 1.2 centipoises and is as high or higher than about 2 centipoises. The upper value can be increased if the head of fluid is correspondingly decreased as would be the case if the dimensions of the intérior of container 30 were increased. A typical head of fluid for such a maximum aperture dimension is 2.29 cm. A particularly useful embodiment is one in which the aperture is generally circular in shape, wlth the circle diameter being 0.038 cm. i 2) It is also preferred that the intersection of the 10 aperture 50 with the platform surface be essentially a sharp ~ I
edge, i.e., having a radius of curvature no greater than about ¦~ :
0.02 cm. Further, the platform should be free of protrusions such as portions of flashing, which would pro~ect either away from the platform or into the fluid passageway. Without such precision in the formation of the aperture, capillary effects would be increased, tending to cause prernature fluid flow.
3) The transition zone between platform 54 and the ;
connecting surface 56 defines an edge 64 which preferably is sufficiently sharp as to prevent the tendency of the serum drop Z0 to climb up the surface 56 under the influence of surfacè
tension. For the range of fluids anticipated, it is preferred that the maxlmum radius of curvature to achievè such an effect does not exceed about 0.02 cm, The effect of the preced~ing features is to confine the drop dispen`sed from the container 30~to the surface of the plat-:~ form 54. It will be appreciated that the entire surface of thep1atform is eontacted by the drop~, and because the drop naturally assumes a quasi-spherical form, the contacted surface area of the ¦
platform will range from about 0.0026 sq. cm. for a 1 ~1 drop, to 3 about 0.018 sq. cm. for a 30 ~1 drop. This represents a range in platform diameter, between edges 64, which is between about 0.05 cm and about 0.15 cm. Alternatively, the surface area ~
supporting, and in contact with, the drop can be increased for ~-,. . ' .,:,: ~
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5QSa3~ t a given drop volume and platform diameter by either 1) forming a downwardly projecting rim around edge 64, 2) making the plat-form surface concave, or 3) roughening the surface of platform 54. Without such roughening, it has been ~ound that a preferred surface smoothness is between about ] to 30 RMS.
To assist in drop detachment and to minimize protein agglomeration in aperture 50, the platform 54 preferably has a cross-sectional thickness from surface 42 to surface 43, measured along a plane extending perpendicular through the platform, which lO is no greater than about 0.025 cm. A particularly useful thick-ness is about 0.013 cm. The effect of such a construction is to minimize the neck of fluid connecting the drop to the main volume ;
in container 30. This in turn permits rapid detachment with ! little secondary flow out of the container.
All of the above features can be obtained by forming ` the container 30 out of copolymers such as acrylonitrile-~,~ butadiene-stryene (ABS), and polymers such as poly(acetal), poly-~propylene), poly(styrene), high density poly(ethylene), and poly-; esters.
- 20 Aperture 70 in portion 72 of si.de walls 38 is preferably ; ~ ~ positioned opposite the aperture 50, and need otherwise be ; construc~ed only as a passageway for ~ressurized ~as generated J ~ exterior to-the container. ~
The dispensing operation i.9 achieved after the centri-fugal separation of the serum, by sliding the container 30 so ~hat end wall 32 no longer blocks end 20 of container l2, Fig. 2, and rim 26 is seated in groove 44 instead of groove 48. The serum is then free to flow into the dispensing chamber and into aperture 50. The dispensing chamber now comprises, in this ~ 3 expanded position, the end wall 32, side walls 38, the ~el 24 i sealing off the cell-portion Or the blood, and the side walls -14 of the serum-collecting portion of container 12, including end 20.
A suitable pressurizing means 80 can be used such as an air hose or a .' ' . ' ' '. '~
~ 050509 collapsible bellows such as is shown in commonl~-owned U.S~
Patent No. 4,041,995 by Richard L. Columbus. By properly increasing the pressure of the interior of container 14 by an amount just necessary to form a 10 ~1 drop, the drop will ~orm as shown in Fig. 2. A suitable support can be used to hold the device during drop dispensing.
To insure that proper drop formation of predictable volume occurs the first time for a given pressure increase resulting from means 80, the total air volume about the serum surface should be minimized. Such a feature can be particularly significant where, as here, the air volume is increased dras-tically before dispensing can be achieved. It has been found that when the air volume above the serum in the dispensing chamber opened to the extended position is about 1300 ~1, for example~ no problem occurs in accurate dispensing. A typical ,1 .
example of dimensions for containers 12 and 30 which provide ` this volume is one in which container 20 has an internal ~i diameter of about o.85 cm between walls 14 and gel 24 is located about 3.6 cm from end 20, and containe~ 30 has an internal diameter between interior surfaces 42-of about 1.05 cm ~, ~ and a separation between grooves 44 and 48 of about 0.7 cm.
In such a case, a typical amount of serum to be dispensed is about 1360 ~1. The above-noted location of the gel occurs when a 50% gel separation occurs upon centrifuglng of an 80% filled container 12 having an exterior length of about 7 cm. ~ -. ,~ ~. .
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As reported in the aforesaid Columbus Patent No.
4,041,995, it has been found that a container 30 constructed as described above, when the contents are appropriately pressurized, repeatedly will give uniform volumetric drops of biological ~luids, such as blood sera, even when the relative viscosityg surface tension and total protein content vary -drastically as is characteristic of blood sera drawn from diseased as well as healthy pat~ents. The coefficient of variation as is commonly used in statistical analysis has been found to be no greater than about 2~ from the mean, thus - insuring that repeated drops have about the same volume. This - -accuracy is achieved not only for blood serum, but also for other biological fluids such as Ringer solutions and water.
It will thus be appreciated that containers 12 and 30 cooperate together to form a shear value, in which the contracted or closed position of container 30, Fig. 1, results in apertures 50 and 70 being blocked by the serum-collecting portion of container 12, from fluid communication with end 20 of container 12. This is done without requiring a separate value part. Serum flow is permitted, however, by sliding the two containers apart into the extended position shown in Fig. 2.
Because the contracted position provides a completely telescoped fit of the two containers, the volume of the device in its serum-separation configuration is essentially the minlmum, i.e.
only the amount needed for the serum separation function.
A further advantage of the invention is that a substantial seal is provided by end wall 32 against end 20, sufficient even to maintain a partial vacuum as is customary . . . .
in serum-collecting devices. Such a vacuum seal can be maintained e~en when container 12 is glass and container 30 is plastic, -- :
for example. Thus, the device of this invention -14a-''':
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,v:Ldes a superior blood collecting device.
In addition to the glass and plastic embodiments shown, both containers can be made of other materials such as plastic, in which case the rim 26 on container 12 can be trans-ferred to container 30 at end 40 to fit into a notch (not shown)-in container 12 when the containers are telescoped together as in Fig. 1. When container 30 is moved to its expanded pressurizable position, an additional notch can be provided for the rim, or alternatively, the rim bearing against the walls 14 of container 12 provides adequate sealing during the dispensing operation.
Turning now to Figs. 4 and 5, there is illustrated an alternate embodiment wherein the relative movable mounting of the two containers is achieved by means of a screw-- thread. Parts similar to those previously described bear -the same reference number to which the distinguishing suffix "a" has been added. Thus, the separation and dispensing device comprises a tubular wall 14a openable at two opposite . ~
ends, defining a serum separation compartment~ and a dispensing ' ~ portion or chamber 30a movably mounted with respect to, and ^l 20 encompassing end 20a of the container 12a, as in the previous embodiment. Also as before, end wall 32a is removably sealed against end 20a o~ the container; and, prior to centrifuging, a gel plug 24a is located in the serum-collecting portion of container 12a which is proximal to end 20a.
However, the relative movement between the two i containers from their closed position, Fig. 4, to the extended position used in dispensing, Fig. 5, is achieved by means of a male threaded portion 90 at end 20a of container 12a, and .~, . .
a female-threaded portion 92 formed in the interior surface 42a the length of the opposed walls 38a. By unscrewing container 30a, the aperture 50a, constructed as before with a platform ~
54a, becomes unbloc~ed by end 20a, so that the serum can flow -from that end to the aperture. A further possible modification is a pour-off nozzle 100 bearing a screw-cap 102, shown in ' :
.
antom. :[n this embodiment, the capped pour-off nozzle 100 acts as an extension of end wa]l 32a in that it still permits the maintenance of a vacuum seal agalnst end 20a and prevents serum flow to aperture 50a, when in the contracted or closed configuration shown in Fig. 1.
' Dispensing in any case is achieved by means of a pressurizing device 80a as in the description of the embodi-ment of Fig. 1.
Turning now to Figs. 6 and 7, still another embodiment is illustrated wherein the blood inlet end coincides with the dispensing chamber, as must be the case when a single-ended tube -is used. Parts similar to those previously described bear the ' same reference numeral to which the distinguishing suffix "b" is appended. Thus, the separation compartment is a container 12b the walls 14b of which close upon themselves at end 18b~ such as in the device shown in U.S. Patent No.
sll ~ 3,852,194. The gel plug 24b in this case must be located, '' prior to centrifuging, in the cell-collecting portion of the ~, compartment which is distal to end 20b. Container 30b is `'' 1, 20~ const~ructed substantially identically as in the embodiment shown in Fig. 1, except that end wall 32b includes at least ; a~portion 110 which ls a flexible elastomer or a rigid synthetic `
plastic capable of penetration by a cannula to permit blood '~
' intake. Thus, portion 110 functlons as a septum, and any ' self-se~aling natural or synthetic elastomer or plastic suffices, such as~butyl rubber. By beveling portion 110 at the juncture :
of inner surface 34b with slde walls 38b, Fig. 7, an annular groove 112 for receiving end 20b in sealed relationship is formed, Fig. 6. The seal permits container 12b to be evacuated, 30 the vacuum of which is used to draw in blood when a cannula ~ ' I is pushed through p.ortion 110 whlle end wall 32b otherwise seals end 20b. 'Alternatively, the blood can be added to container 12b as shown in the above-noted patent No. 3,852,194, and the i'~
, , . . ' ,~ . , ~
- ~05~;35~9~
~ `ntainer 30b can be then mounted over container 12b for the .. , , centrifuge step and dispensing as described hereafter. The flexible portion 110 in such a case serves as an adequate stopper for the centrifuging step.
Side walls 38b preferably are provided, as in Fig. 2, with a groove 44b~ and optionally, a groove 48b and 0-ring 49b, to receive rim 26 of end 20b. Alternatively, groove 48b can be formed entirely within end wall 32b, such as by molding, and portion 110 can be of reduced diameter such that portion 110 does not take part in the sealing of end 20b to end wall 32b.
Dispensing is achieved as described concerning Fig. 1, by sliding container 30b to its expanded position, Fig. 7, thus opening the shear valve to permit flow of serum to aperture 50b unblocked by the sliding motion. The dispensing ohamber so formed again includes the gel 24b re-positioned transversely across container 12b to seal the serum from the - ~ ¦~
, cellular portion of the blood. -¦ As in the embodiment of Fig. 1, ~he telescoping of ¦
the two oontainers 12b and 30b can be achieved by a screw thread~as shown in the embodiment of Fig. 4.
Pig. 8 illustrates a further modlfication wherein the walls of the separation compartment are no longer cylin-drical. Similar parts bear the same reference numerals with '~ a suffix;"c". Thus, the containers 12c and 30c are formed 1 .
and function together as described above for the embodiment of Figs. l or 6, except that opposed walls 14c form a 4-sided, preferably right-angled tube, to which the interior surface 42c of walls 38c are matched, to illustrate that other shapes of container 12 are contemplated.
In all of the preceding embodiments, it w111 bè -appreciated that the container 30 used for dispensing can be added onto a conventional vessel containing serum, :. . ..
~ ;
S1~5~9 separated in any manner from blood cells, for dispensing the serum in the manner of the invention. For example, container 12 can be a container available under the trademark "Corvac"
from Corning Glass Works, to which container 30 is added after the sample has been centrifuged.
The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
"-,,' .
.. . .:
"i .
.
,~ ' . '~' :7 .
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.' ,:' ' ~ ~
:1 ' ~ '.' 17: .
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. .
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Claims (33)
1. A blood serum dispensing device, comprising two containers movably mounted one partially within the other, one of said containers being a compartment having opposed ends, one end being open for fluid communica-tion with respect to the other container;
said other container comprising an end wall, and at least one side wall extending from one surface of said end wall and encompassing at least said one open end of said one container;
said one side wall being provided with an aperture capable of providing fluid communication into or out of said other container with respect to the exterior surface thereof;
said end wall being removably sealed against said one end to prevent fluid flow therefrom, and said aperture being removably blocked from fluid communication with said one container by said one container;
and further including means for sealing together said side wall and said one end when said other container end wall is pulled away from said one end, so as to permit fluid flow out of said aperture when pressure is generated within said other container.
said other container comprising an end wall, and at least one side wall extending from one surface of said end wall and encompassing at least said one open end of said one container;
said one side wall being provided with an aperture capable of providing fluid communication into or out of said other container with respect to the exterior surface thereof;
said end wall being removably sealed against said one end to prevent fluid flow therefrom, and said aperture being removably blocked from fluid communication with said one container by said one container;
and further including means for sealing together said side wall and said one end when said other container end wall is pulled away from said one end, so as to permit fluid flow out of said aperture when pressure is generated within said other container.
2. The device as defined in claim 1 wherein said containers are telescoped together along a common axis.
3. The device as defined in claim 1 wherein said opposed walls have an interior surface and wherein said sealing means include a groove in said surface extending completely around said one container, said groove being adapted to seal against said one end when said end wall of the other container is moved away from said one end.
4. The device as defined in claim 1 wherein said aperture has a maximum dimension which is sufficiently small as to prevent gravity flow of serum therethrough, and further including a second aperture in said side wall for pressurizing serum in said other container, said second aperture being blocked by said one container when said end wall seals said open end.
5. The device as defined in claim 1 wherein said, one container is a serum separation compartment including a serum-collecting portion adjcent said first end and a movable plug in contact with the walls of said compartment transversely across said compartment, for interrupting serum flow through the compartment, said plug being provided with means permitting flow of blood serum to said serum collecting portion when a centrifugal force sufficient to initiate separation of the blood serum from the blood cells is generated from said one end towards the opposite end of the compartment.
6. The device as defined in claim 5 wherein said plug comprises an inorganic thixotropic polymeric gel inert to the serum, having a specific gravity between about 1.03 and about 1.05 and a viscosity between about 400 and about 500 poises at a shear rate of about 500 sec.-1.
7. The device as defined in claim 1 wherein said containers are free of a separate valve positioned to block flow between said compartment and said aperture.
8. The device as defined in claim 1 wherein said one side wall has an inner and an outer surface, and a platform for supporting a pendant drop, connected to and ?ced away from the said outer surface by a connecting surface, the distance between the platform and said outer surface being sufficient to prevent dispensed serum from spreading from the platform to said outer surface, the connecting surface being inclined at an angle with respect to said platform which will confine the drop to the platform, the transition zone between the exterior surface of the platform and the connecting surface being sufficiently sharp as to form an edge which will confine the drop to said exterior surface, said platform including said aperture capable of providing pressurized flow from the interior of said other container, said aperture having a maximum dimension which is insufficient to permit gravity flow of serum through the aperture, said platform exterior surface defining a drop-contacting area which will support a drop having a volume between about 1 and about 30 µ1.
9. The device as defined in claim 1 wherein at least a portion of said end wall is a flexible elastomer capable of penetration by a cannula, whereby whole blood can be added to said containers through the end wall when it is sealed against said open end.
10. The device as defined in claim I wherein said two containers are vacuum-sealed together.
11. A blood serum separation and dispensing device, comprising:
two generally elongated containers each having a first and a second opposed ends, the first end of one container being movably mounted within the first end of said other container, said one container including 1) a serum separation compartment open at at least said first end for fluid communication with respect to the other container, 2) a serum-collecting portion of said compartment adjacent said first end, 3) and a movable plug in contact with the walls of said compartment transversely across said compartment for interrupting fluid flow through the compartment, said plug being provided with means permitting flow of blood serum to said serum collecting portion when a centrifugal force sufficient to initiate separation of the blood serum from the blood cells is generated from said first end towards the second end of said one container;
said other container being mounted over said first end of said one container, and comprising an end wall at its second end and opposed walls extending from one side of said end wall, said opposed walls having interior surfaces dimensioned so as to accommodate said serum-collecting portion of the one container between them;
at least one of said opposed side walls being provided with an aperture capable of providing fluid communication into or out of said other container with respect to the exterior surface thereof;
said end wall of the other container being removably sealed against said first end of said one container, and said aperture being removably blocked from fluid communication with said one container by said serum-collecting portion;
and further including means for sealing said interior surfaces of said opposed walls with respect to said first end of said first container when said end wall is moved away from said first end, so as to permit said aper-ture to be in fluid communication with said first end of said one container.
two generally elongated containers each having a first and a second opposed ends, the first end of one container being movably mounted within the first end of said other container, said one container including 1) a serum separation compartment open at at least said first end for fluid communication with respect to the other container, 2) a serum-collecting portion of said compartment adjacent said first end, 3) and a movable plug in contact with the walls of said compartment transversely across said compartment for interrupting fluid flow through the compartment, said plug being provided with means permitting flow of blood serum to said serum collecting portion when a centrifugal force sufficient to initiate separation of the blood serum from the blood cells is generated from said first end towards the second end of said one container;
said other container being mounted over said first end of said one container, and comprising an end wall at its second end and opposed walls extending from one side of said end wall, said opposed walls having interior surfaces dimensioned so as to accommodate said serum-collecting portion of the one container between them;
at least one of said opposed side walls being provided with an aperture capable of providing fluid communication into or out of said other container with respect to the exterior surface thereof;
said end wall of the other container being removably sealed against said first end of said one container, and said aperture being removably blocked from fluid communication with said one container by said serum-collecting portion;
and further including means for sealing said interior surfaces of said opposed walls with respect to said first end of said first container when said end wall is moved away from said first end, so as to permit said aper-ture to be in fluid communication with said first end of said one container.
12. The device as defined in claim 11 wherein said containers are telescoped together along a common axis, said other container being slidable with respect to said one container from a closed position in which said end wall is sealed against said first end, to an open position wherein said sealing means seals said other container with respect to said first end.
13. The device as defined in claim 12 wherein said sealing means is a groove within said interior surfaces shaped to accommodate the first end of said one container.
14. The device as defined in claim 12 wherein at least a portion of said end wall is a self-sealing flexible elastomer capable of self-sealing penetration by a cannula, whereby whole blood can be added to said containers through said end wall when said other container is in its closed position.
15. The device as defined in claim 12 wherein said aperture has a maximum dimension which is sufficiently small as to prevent gravity flow of serum therethrough, and further including a second aperture in said opposed walls, generally opposite to said first aperture, for pressurizing serum in said other container, said second aperture being blocked by said serum-collecting portion when said other container is in said closed position.
16. The device as defined in claim 11 wherein said other container is telescoped over said first end with said one opposed wall in an overlapping, sliding relationship with the serum-collecting portion of said compartment, whereby said one opposed wall and said serum-collecting portion form shear valve with respect to said aperture.
17. The device as defined in claim 11 wherein said containers are free of a separate valve positioned to block flow between said compartment and said aperture.
18. The device as defined in claim 11 wherein said plug comprises an inorganic thixotropic polymeric gel inert to the serum, having a specific gravity between about 1.03 and about 1.05 and a viscosity between about 400 and about 500 poises at a shear rate of about 500 sec. 1.
19. The device as defined in claim 11 wherein said one opposed-side wall has an inner and an outer surface, and further including a platform, for supporting a .
pendant drop, connected to and spaced away from the said outer surface by a connecting surface, the distance between the platform and said outer surface being sufficient to prevent dispensed serum from spreading from the platform to said outer surface, the connecting surface being inclined at an angle with respect to said platform which will confine the drop to the platform, the transition zone between the exterior surface of the platform and the connecting surface being sufficiently sharp as to form an edge which will confine the drop to said exterior surface?
said platform including said aperture in fluid communication with the interior of said other container, said aperture having a diameter smaller -than that which will permit gravity flow of serum from the container, said platform exterior surface defining a drop-contacting area which will support a drop having a volume between about 1 and about 30 µ1.
pendant drop, connected to and spaced away from the said outer surface by a connecting surface, the distance between the platform and said outer surface being sufficient to prevent dispensed serum from spreading from the platform to said outer surface, the connecting surface being inclined at an angle with respect to said platform which will confine the drop to the platform, the transition zone between the exterior surface of the platform and the connecting surface being sufficiently sharp as to form an edge which will confine the drop to said exterior surface?
said platform including said aperture in fluid communication with the interior of said other container, said aperture having a diameter smaller -than that which will permit gravity flow of serum from the container, said platform exterior surface defining a drop-contacting area which will support a drop having a volume between about 1 and about 30 µ1.
20. A blood serum separation and dispensing device, comprising two generally elongated containers telescoped one within the other along a common axis, one of said containers forming a serum separation compartment having opposed ends one of which is capable of fluid communication with respect to the other container, the other container forming a col-lapsible dispensing chamber having with respect to said one container a contracted, evacuatable position, and an extended, pressurizable position;
said one container further being comprised of a serum-collecting portion proximal to said one end, a cell-collecting portion distal to said one end, and a movable plug for interrupting fluid flow through the compartment, said plug being provided with means permitting flow of blood serum to said serum collecting portion when a centrifugal force sufficient to initiate separation of the blood serum from the blood cells is generated towards the end opposite to said one end;
said other container being further comprised of an end wall and opposed walls extending from one side of said end wall, said opposed walls having interior surfaces dimensioned so as to accommodate said serum-collecting portion of the one container between them, said opposed walls further having a dispensing aperture and a pressurizing aperture;
said dispensing chamber comprising, in its extended position, 1) said end wall and opposed walls, 2) telescoped within said opposed walls, the serum-collecting portion and said one end of said compartment, and 3) opposing said end wall, said movable plug in contact with the walls of said compartment transversely across said compartment, sealing off said serum-collecting portion from said cell-collecting portion, whereby said chamber and said compartment are movable with respect to each other to form in said con-tracted position, sealed compartments incapable of flow of serum out of the chamber, and in said extended position, compartments capable of pressurized flow of the serum out of the chamber.
said one container further being comprised of a serum-collecting portion proximal to said one end, a cell-collecting portion distal to said one end, and a movable plug for interrupting fluid flow through the compartment, said plug being provided with means permitting flow of blood serum to said serum collecting portion when a centrifugal force sufficient to initiate separation of the blood serum from the blood cells is generated towards the end opposite to said one end;
said other container being further comprised of an end wall and opposed walls extending from one side of said end wall, said opposed walls having interior surfaces dimensioned so as to accommodate said serum-collecting portion of the one container between them, said opposed walls further having a dispensing aperture and a pressurizing aperture;
said dispensing chamber comprising, in its extended position, 1) said end wall and opposed walls, 2) telescoped within said opposed walls, the serum-collecting portion and said one end of said compartment, and 3) opposing said end wall, said movable plug in contact with the walls of said compartment transversely across said compartment, sealing off said serum-collecting portion from said cell-collecting portion, whereby said chamber and said compartment are movable with respect to each other to form in said con-tracted position, sealed compartments incapable of flow of serum out of the chamber, and in said extended position, compartments capable of pressurized flow of the serum out of the chamber.
21. The device as defined in claim 20, and further including means in said opposed walls for sealing said interior surfaces to said telescoping end when said chamber is in said expanded position.
22. The device as defined in claim 21 wherein said sealing means is a groove within said interior surface shaped to accommodate said telescoping end.
23. The device as defined in claim 20 wherein said serum-collecting portion and said opposed walls form a shear valve with respect to said apertures.
24. The device as defined in claim 20 wherein said one opposed side wall has an inner and an outer surface and a platform for supporting a pendant drop, said platform being connected to and spaced away from the said outer surface by a connecting surface, the distance between the platform and said outer surface being sufficient to prevent dispensed fluid from spreading from the platform to said outer surface, the connecting surface being inclined at an angle with respect to said platform which will confine the drop to the platform, the transition zone between the exterior surface of the platform and the connecting surface being sufficiently sharp as to form an edge which will confine the drop to said exterior surface, said platform including said aperture in fluid communication with the interior of said other container, said aperture having a diameter smaller than that which will permit gravity flow of serum from the container, said platform exterior surface defining a drop-contacting area which will support a drop having a volume between about 1 and about 30 µ1.
25. The device as defined in claim 20 wherein said containers are free of a separate valve positioned to block flow between said compartment and said aperture.
26. The device as defined in claim 20 wherein said plug comprises an inorganic thixotropic polymeric gel inert to the serum, having a specific gravity between about 1.03 and about 1.05 and a viscosity between about 400 and about 500 poises at a shear rate of about 500 sec.-1.
27. The device as defined in claim 20 wherein said plug is movably positioned in said cell-collecting portion and wherein said end wall includes at least a portion which is a flexible elastomer capable of self-sealing penetration by a cannula.
28. A dispensing container for use with a blood serum separation device which includes a separation compartment open at at least one end of the compartment; the container comprising a generally cylindrical dispensing chamber having an end wall and a platform at one side thereof suitable for the formation of drops;
said platform having an aperture in fluid communi-cation with said chamber, the maximum dimension of the aperture being sufficiently small as to prevent flow of the serum under gravity;
a passageway capable of fluidly connecting the separation compartment to the chamber;
and means for slidably moving said container between two sealed positions which encompass the open end of the compartment, one of said positions being such as to locate said aperture in alignment with the walls of the compartment so as to block fluid flow out of the aperture, and the other of said positions being such as to locate said aperture free of any blocking surface;
said container being free of a separate movable valve mounted within said chamber.
said platform having an aperture in fluid communi-cation with said chamber, the maximum dimension of the aperture being sufficiently small as to prevent flow of the serum under gravity;
a passageway capable of fluidly connecting the separation compartment to the chamber;
and means for slidably moving said container between two sealed positions which encompass the open end of the compartment, one of said positions being such as to locate said aperture in alignment with the walls of the compartment so as to block fluid flow out of the aperture, and the other of said positions being such as to locate said aperture free of any blocking surface;
said container being free of a separate movable valve mounted within said chamber.
29. The container defined in claim 28 wherein said chamber further comprises:
a first wall having an inner and an outer surface, and opposed side walls extending from said inner surface to define at least one compartment having a capacity for the fluid sufficient to permit at least one drop to be dispensed there-from, said aperture being in said first wall, said platform being connected to and spaced away from the said outer surface by a connecting surface, the distance between the platform and said outer surface being sufficient to prevent dispensed fluid from spreading from the platform to said outer surface, the connecting surface being inclined at an angle with respect to said platform which will confine the drop to the platform, said platform exterior surface defining a drop-contacting area which will support a drop having a volume between about 1 and about 30 µ1.
a first wall having an inner and an outer surface, and opposed side walls extending from said inner surface to define at least one compartment having a capacity for the fluid sufficient to permit at least one drop to be dispensed there-from, said aperture being in said first wall, said platform being connected to and spaced away from the said outer surface by a connecting surface, the distance between the platform and said outer surface being sufficient to prevent dispensed fluid from spreading from the platform to said outer surface, the connecting surface being inclined at an angle with respect to said platform which will confine the drop to the platform, said platform exterior surface defining a drop-contacting area which will support a drop having a volume between about 1 and about 30 µ1.
30. The container as defined in claim 28 wherein said chamber has an additional aperture in fluid communication with the exterior of the container, whereby said chamber can be pressurized.
31. The container as defined in claim 28 wherein said end wall includes a flexible portion capable of penetration by a cannula.
32. A blood collection, separation and serum dispensing device, comprising two containers movably mounted one partially within the other, one of said containers being a compartment having opposed ends, one end being open for fluid communication with respect to the other container;
said other container comprising an end wall, and at least one side wall extending from one surface of said end wall and slidable over at least said one end of said one container;
said one side wall being provided with an aperture capable of providing fluid communication into or out of said other container with respect to the exterior surface thereof;
said end wall being removably sealed against said one end to prevent fluid flow therefrom, and said aperture being removably blocked from fluid communication with said one container by said one container;
and further including 1) means for sealing together said side wall and said one end when said other container end wall is pulled away from said one end, so as to permit fluid flow from said one end to said aperture when pressure is generated within said other container;
2) means at one end of at least one of said con-tainers for permitting the collection of whole blood within said one container, and 3) means for maintaining the separation of blood serum from blood cells when centrifuging causes the whole blood to separate into the serum and blood cells.
said other container comprising an end wall, and at least one side wall extending from one surface of said end wall and slidable over at least said one end of said one container;
said one side wall being provided with an aperture capable of providing fluid communication into or out of said other container with respect to the exterior surface thereof;
said end wall being removably sealed against said one end to prevent fluid flow therefrom, and said aperture being removably blocked from fluid communication with said one container by said one container;
and further including 1) means for sealing together said side wall and said one end when said other container end wall is pulled away from said one end, so as to permit fluid flow from said one end to said aperture when pressure is generated within said other container;
2) means at one end of at least one of said con-tainers for permitting the collection of whole blood within said one container, and 3) means for maintaining the separation of blood serum from blood cells when centrifuging causes the whole blood to separate into the serum and blood cells.
33. The device as defined in claim 32 wherein said other container includes a flexible portion capable of penetration by a cannula.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US60912175A | 1975-08-29 | 1975-08-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1050509A true CA1050509A (en) | 1979-03-13 |
Family
ID=24439428
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA253,130A Expired CA1050509A (en) | 1975-08-29 | 1976-05-21 | Telescoping serum separator and dispenser |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1050509A (en) |
-
1976
- 1976-05-21 CA CA253,130A patent/CA1050509A/en not_active Expired
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