Note: Descriptions are shown in the official language in which they were submitted.
B~CKGROUND ~F THE ~NyENTIoN
1) F~eld of- the Inventi:on
Th~s invent~on relates to a container ~hlch prov~des
for the collection o~ a ~a~pl~ o~ a b~ological fluid, the cen-
trifugat~on o~ ~e ~luid ~n the ca~e o~ serum, and accurate
dispensing of micro amounts of the ~luid for testing~ all with-
out requiring t~e pouring o the ~luid iht~ a variety of separate
containers.
2I State of the Prior Art
The most common cQnvention~lmethod of providing
biological fluid such as blood ~erum for clinical analysis
utilizes a plurality of containers en route to the actual test.
That is, the blood sample is con~entionally collected in an
evacuated container, and separation o~ the serum from the whole
cells may be achieved by centrifuging the sample within that con-
tainer~ or withdntanother container to which the sample has been
transferred. Thereafter, the serum is commonly poured off into yet
another container for the desired clinical testing. All such tran~-
fer operationæ are time consuming, requiring either hand process-
ing or complicated, expensive automatic handling. Furthermore,
wheneve~ there is a transfer of a liquid sample to a separate~j open
container, the sample is aerated and C02 loss or gain can occur.
The~e is also the danger of improper transfer, either by the use
of the Wrong container, by the improper patient labeling of the
; new container, or by both. Still further, contamination of the
serum by foreign materials or infection of the operator can occur~
Rbuse of the same dispensing device for sequential samples requires
- careful sterilization to avoid contamination. Thus, a system which
keeps the blood sample confined to essentially one container from
3a its collection to the actual dispensing for analys~s is a distinct,
sought-after improvement.
At 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
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cells and serum is prevented. U. S. patent Nos. 3,647,070;3,779,383; 3,780,935; 3,800,947; 39849,072 and 3,850,174 are
representative of device~ Or this nature. In U. S. patent
Nos. 3,647,070~ 3,779,383; 3,800,947 and 3,849,072, for example,
there are dlsclosed mechanlcal valve devices which prevent flow
acro~s the interface. Such devlces however are quite compli-
cated, resulting in increa~ed cost of manu~acture, and requiring
in some lnstanceR more than one tubular container. Furthermore~
they are susceptible to mechanical ~ailure and do not automatic-
ally seek out the serum-cell interface. Instead3 a mechanical
constrlction of some kind must be provided which will not permlt
varlation ln blood volume~. Devlces such as are shown in U. S.
patent No, 3,779,383 are not provided with valve means at the
- serum end to permlt ready removal of the serum. Instead, the
plug must be removed and the serum elther poured off, as by
tlltlng the contalner, or it must be aspirated or otherwise
drawn of~.
0~ the many devices avallable to provlde blood serum
~or analy31s, the one whlch has become the norm i8 the evacuated
contalner. Thls ls ~lmply a p~rtlally evacuated glass tube open
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at one end except for a septum placed there. One improvementover such an evacuated container which is particularly useful
comprises a glass tube open only at one end, a septum fixed to
that end when the tube is evacuated, and a movable plug contained
within the tube. The plug is preferably a silica gel, ~ith or
without a plastic cup-like mandrel positioned wi~h 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 speci~ic gravity works up to the serum-
cell interface where it plugs the container against remixing of
the serum and cells. An example of such a container but without
the mandrel is shown in ~.S. Patent No. 3,852?194.
AIthough such a device is useful in separating the
serum from the cells, it has not avo~ded the transfer di~iculties
noted above~. Furthermore, by pouring out the serum through the
theretofore septum-plug~ed end, it is possible to contaminate
the serum wi~h blood cells which collected at the septum container
inter~ace prior to centrifuging~ a condition known as "blood-
ring contamination." Still further, coagulation is required toassure maximum serum separation, and this requires about a 10
minute "hold" even when coagulants are used.
~; ¦ Other patents relating to blood serum separation in
I
general are U.S, Patent Nos. 3~6~5,253; 3,687,296; 3,706,305;
l 3,706,606, and 3,771,965. Some of these, while not relying on a
plug to provide a barrier between serum and cells, use a filter.
The disclosure of Patent 3,771,965 specifically protects the out-
I let of the evacuated container from blood ring contamination.
¦ In commonly owned UOS. Patent No. 3,977,568 of David
¦ 30 Smith entitled "Biological Fluid Dispenser for Dispensing Micro
Amo~mts," issued August 31, 1976, there is disclosed the dispensing
~1 of a fluid such as serum from a blood separator by the connection
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thereto o~ a separate: dispensing head, the dispenslng head
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relying~ ~or example, upon piston action to dispense the
serumL A conventional bloo~ separator such as the glass tube
type descrlbed above, is shown.
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OBJECT~; OF T}IE ~NV3~NT;I;ON
It is an o~j~Ct ~ the ~n~ention to provide apparatus
for separating blood serum ~rom blood ~hich is capa~le of
tran~mitting the separated s~rum to ammetering device ~ith a
mlnimum of handling.
A related object of the LnYention is to provide such
apparatus which eliminates the need for the addition of oth~r
devices during the processing of the serum, to complete that
processing.
Another related object of the invention i~ to provide
such apparatus wherein a single container is used to handle the
blood for all its processing prior to actual testing, namely for
the collection of a blood ~ample from a patient~ the centri~uging
of the sample to segregate the blood serum, and the dispensing
of the serum in accurate micro amounts.
Another object o~ the invention is to provide such
apparatus in as compact a form as possible so as to be readily
stored and dispensed.
Another object oi the invention is to provide a serum
3eparator which minimizes the delay prior to centrifuging which
is necessary for coagulation.
`~ Yet another object of the invention is to provide
; an apparatus for separating ~lood serum from blood cells by
centrifugation, having an improved seal which prevents remrxing
~ of the two components.
-~ Still another object is to pro~ide such apparatus
~hich by reason of its simplicity can be disposed of after use
thereof with one ~lood sample, to avoid the need for careful
sterilization.
Yet another object o~ the invention is to provide such
apparatuS Which ~ill prevent blood ring contamination of the serum.
Other objects and adyantage~ will become apparent upon
reference to the following Summary and Description of Preferred
Embodiments, when considered in light of the attached drawings.
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SUMMARY OF THE INVENTION
The invention concerns a blood handling device
which simplifies the processing of whole blood taken from a
patient whereby serum is extracted therefrom and dispensed
for testing. In accordance with the teachings of the inven-
tion~ there is provided a blood serum separating and dis-
pensing device, comprising opposed walls arranged about an
axis to define a blood collection and phase separation
compartment having two opposed ends; a dispensing chamber
adjacent one of the compartment ends, the chamber including
an exterior platform suitable for dispensing drops and a
dispensing aperture in the platform; means for temporarily
blocking flow to the aperture of liquid collected in the
compartment; and a movable plug disposed in a blocking
position in the compartment in contact with the walls of
the compartment, to interrupt liquid flow through the com-
partment, the plug comprising an inorganic thixotropic
polymeric gel inert to blood serum.
The invention is also directed to a biological
fluid processing container, the container comprising an
exterior, unitized body, having two opposite ends and at
least one exterior face extending between the two ends, the
body having a first compartment for a biological fluid, the
compartment extending from one of the ends to a first locator
surface spaced from the other end, the body having a second
compartment oriented so as to extend generally perpendicularly
to the first compartment between the ends to a second
locator surface, the compartments being in selective fluid
communication; a septum secured to the one end, comprising a
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sel~-sealing elas~omeric material capable of penetration by
a cannula; a value interposed with respect to the compartments
so as to selectively block fluid flow between the compart-
ments; the body including a thi.rd compartment extending from
the second locator surface to an opening in the body between
the ends, the third compartment being in fluid communication
with the second compartment, the body further including a
platform in which the opening is generally centered~ for the
formation of drops, the opening having a maximum dimension
which is sufficiently small to prevent flow of the biological
fluid therethrough under gravity; and means on the one
body face for identifying the source o~ the ~luid; whereby
the container can be transported from the patient to a
metering station without transferring the fluid or any part
thereof to another container.
Such a device can be transported from the patient,
to the serum-separating station, and to the metering station
without once transferring the blood or any part of it to a
separate, disconnected container. Alternatively, conventi.onal
removal can be obtained such as by pour-off. Patient
identiPicetion i9 insured
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BRIEF DESCRIPTION OF THE DRAWINGS
F~g. 1 is a sectional view o~ an evacuated serum
separator constructed in ~ccordance with the prior art;
Figs. 2A and 2B are sectional views of a serum
separator constructed in accordance with the invention, the
first of which illustrates the device prior to blood collectiong
and the second of which illustrates the device after centrifuging;
Fig. 2C is a plan view of the mandrel shown in
phantom, Fig. 2B;
~ig. 3 is a perspective view of a unitized container
of the invention within which the separator of Fig. 2 can be
lncorporated;
Fig. 4 is an elevational view in section of the
container of Fig. 3, lllustratlng lts orientation for
centrifuging;
Fig. 5 is an enlarged sectional view of a portion
of Fig. 4, namely of cavity 96;
Figs. 6 and 7 are views similar to Fig. 5 but of
- alternate embodiments;
Flg. 8 ls a ~ragmentary vlew slmllar to Fig. 4, buk
lllustrating the use of the container to dispense the serum
a~ter centrifugal separation;
. Fig. 9 is a fragmentary sectional vlew similar to
Flg. 8~ but illustrating the pour-of~ override mechanism;
Fig. 10 is a partially broken away plan view of an
alternative embodiment of the oontainer;
Flg.. 11 1~ a sectional vlew, partially broken away,
generally taken along the llne XI-XI of Fig. 10;
Fig. 12 is a sectional view similar to Fig. 11, but
3 without the valve;
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Fig. 13 is an end elevational view of the container
o~ Flg. 10;.
Pig. 14 is a perspectlve view o~ the valve shown in
Fig. 11;
: Fig. 15 is an elevational view of an alternate
embodiment of the valve of Fig. 14;
Fig. 16 is a plan view of the valve of Fig. 15;
Figs. 17-19 are fragmentary sectional views of a
; valve similar to that shown in Fig. 15, but illustrating other
embodiments,
Figs. 20-2~ are ~sec - tionàl views similar to Fig. 11,
: ~ut illustratlng still other ëmbodiments~ and
Fig. 24~is a sectional vie~ of the improved septum
jf F~g. 23
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DESCRIPTION OF T~ PREFERRED EMBODIM:ENTS
The invention is intended for use in the dispensing
- of blood sera directly from blood separators onto suitable
substrates, for clinical analysis. Typical o~ such substrates
are those shown, for example, in U.S. Patent No. 3,992,158
issued to E. Przybylowicz et al on November 16,-1976. Howeverg
the apparatus of this invention is neither limited to use with
just such substrates, nor to just the dispensing of drops of
blood sera. Other ~luids capable of being dispensed can also be
handled by this apparatus.
As used in this application, terms such as "up" and
- "down" refer to the orientation of the disclosed parts during
their actual use, in reference to the direction of the force of
gravity~
There is illustrated in Fig. 1 a blood serum separator
20 which is typical of those prior art devices described above
featuring a gel plug. In such devices, a tubular container 22,
made for example from glass to permit the formation and
maintenance of a vacuum, has a closed end 24, an open end 26,
~l 20 a septum 28 fitted into the open end, a gel 30 positioned
! adjacent to the closed end, and a mandrel 32 embedded in the
~ gel, the mandrel being a cup-shaped member with its open end
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34 extending towards the septum. Closed end 35 of the mandr-el
is ad~acent to closed end 24 o~ the container. Typically, the
gel 30 is a silica gel which can be a blend of hydrophobic silicon
dioxide and a silicone. lf the gel is used by itself without
a mandrel, as is taught for example in the aforesaid U.S. Patent
No. 3~852,194, the silicone can be dimethyl~olysiloxane, blended
~ to give a thixotropic gel having a specific gravity between
1 3 about 1.035 and 1.06, and preferably about 1.04-1.05, and a
viscosity between about 400 and about 500 poise at a shear
rate of about 500 sec. lj and typically 451 poise at 506 sec. 1.
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Such a device operates to separate blood serum
from cells in the following manner. A~ter blood is drawn
into the separator 20 by a cannula, not shown, a centrifugal
; force F is applied from the septum 28 towards the closed end
24. The force causes the heavier blood cells to separate
from the serum and ~he gel to flow past the mandrel. In
reaction, the lighter weight gel moves past the mandrel,
assisted by optional r~bs 36 thereon, towards septum 28.
Because the gel has a spPcific gravity between ~hat of the
cells and serum, while the pla tics commonly used with the
mandrel have a speciflc gravity (1.186) greater than both,
the gel moves to seal the serum-c~ll inter~ace but the mandrel
.remaln~ subs~antlally where -it was inltially, leaving
the gel seal without any structural reinforcement. A better
plugglng or sealing to prevent remixing of cells and serum would
~: be achiPved i~ the mandrel remalned with the gel.
As is common in the art, the mandrel may be provided
with glass beads, not shown, to ald in the clotting of the
cells. This require~, however, that the sample 3it in the container
for about 10 minutes prior to centrifu~ation.
A representative ~eparator of the above type is
manufactured by Corning.Glas~ Works under the trademark
"Corvac".
Turning now to Figs. 2A, 2B and 2C, in accordance
. with one aspect of the invention, there is provided a blood
serum separation device 40 having advantages over the device
.
shown in Fig. 1. Such a devlce 40 comprises a generally
~ tubular wall 42 such as can be achieved by opposed walls
arran~ed about an ax~s 44 to deflne a blood separation
30 compartment open at both ends 46 and 48, a closure means 50 such as a
septum ecured to end 46 which serves as a blood inlet,means secured
to the other end 48 for temporarily blocking serum flow out of the
compartment, and a movable plug comprlsing gel 30 substan-
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tially identical to that descri~ed for ~ig. 1, dispo~ed adjacent
to the blocking mean~. Thu$, the compartment can be any suitable
shape, ~n-clu~ing cylindr~cal. As s~o~n, the blocking means com~
prises a frangible member 52 such as a thin sheet of metal the
edges 54 of ~hich are ~xapped around end 48 of ~alls 42. The serum
can be dispensed merely by punching through the sheet, as des-
cribed below. ~s is conventional, septum 50 can be formed from a
sel~-sealing elastomeric material capa~le of penetration by the
cannula u8ed to fill the compartment.
Such a construction of device 4Q permits the centrifugal
force F to be applied towards the septum end, by spinning the
device about a point of rotat~on "X" positioned adjacent end 48.
The portion adjacent to end 46 becomes the cell-collecting portion
of the compartment, and the portion adjacent end 48 becomes the
serum-collecting portion. Member 52 permits subsequent withdrawal
of the serum S out and 48 in a manner described below, rather than
end 46. The gel 30 thus is initially positioned in the serum-
collecting portion, where it assists member 52 in closing that end
o~f to fluid flow prior to cent~ifuging, thus permitting partial
2Q evacuation o~ the container. Furthermore, the plug ~ormed by gel
30 serves as means or preventing any "blodd ring" from forming
at the junction o~ the blocking means 52 With the end 48, thus
preventing "blood ring contamination".
Yet another advantage of device 40 is that the gel moves
with the line o~ force F, rat~er than against it, so as to permit
the gel to be used without a mandrel. However, optionally the
mandrel 32 o~ Fig. 1, sho~n in phantom in Fig. 2B, and in solid
lines in Fig. 2C and Fig. 4, can be used. In that event, the man-
drel is initially oriented With its open end 34 towards the temp-
3a orary blocking means rather than the septum, and the closed end 35towards the septum. Although the mandrel 32 can be identical in
structure with that sho~n in Fig. 1, its behavior during cent-
ri~uging is quite different due to the
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lnitlal pos~tion of ~he gel and the mandrel. That is, not
only is the mandrel 32 imbedded in the gel lnitlally (Flg.
4) J in the serum collecting portion, it stays imbedded in
the gel as together they move with the gradually ~ormlng
serum-cell interface. Such a combination gives the gel a
structural reinforcemen~ which in~ures that the final posi-
tioning o~ the plug, Fig. 2B, wlll in fact effectively
coincide with and seal the interface against remixing of the
cells C and the serum S. It is believed that ~he mandrel 32
does not move into the cell-collecting portion adjacent end 46
because together the gel and mandrel provide a specific gravity
less than that of the cells C. Also~ it appears that the spacing
of the mandrel from the walls 42, and the ribs 36, are adequate
to assist in the countercurrent flow of the serum S past the
mandrel and gel during centrifuging3 and that such flow occurs
a~ soon as the centrl~ugal ~orce F lnitlates separatlon of the
~erum from the blood cells.
.
Still another alternate embodiment within the scope
of this invention is the use o~ plastlc beads as a gel extender
ln lieu of the mandrel. ~he beads move with the gel durlng cen-
trifuging.
I~ is not clear what the actual mechanlsm is for the
gel-serum movement, but it 1s believed that, as soon as a cen-
trifuging ~orce F is applled9 the serum when separated moves
agalnst the gel towards end 48, due to its lighter specific
gravity. If a mandrel is used, the gel has nowhere else to go,
except into the mandrel 32, the open end 34 of the mandrel being
directed towards the gel. A~ter the~ separation is complete, the
flow of the serum past the plug terminates and continued spinn~lng
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oauses the mass of the gel to ~pread back into contact with the
wall of container 40, completing the seallng arrangement.
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The structural rein~orcement given to ~he gel hy the
mandrel is of particular utillty when ~orces occur which tend
to disturb the gel. One example o~ such forces occurs when the
centrifuged sample is frozen prior to removal of the serumO
Without structural reinforcement, there is a tendency of the
expansion o~ the frozen blood cell~ to distort the
gel seal.
By its simplicity, ~he device 40 is quite suitable
to disposal after a single use,-thus avoiding the need for
sterilization between samples.
To further improve the spening of member 52, and to
process and control the dispenslng of the serum S.in a unit
container, so as to di~pense it only in micro-liter drops, the
processing container 60 is provided as shown in Figs. 3-7. The
container comprises a box-llke frame defined by walls 72, 73 and
74, confining therein,Fig. 4, a separator-holding cavlty 64
at one end 66, a mounting aperture 68 at the opposite end 70
.: of the frame for a plunger 110 described hereafter, and a
dispensing chamber 82 located ad~acent to cavity 64 between the
-o endl 66 and 70. Shamb f92 1~ ln alr co~ununicatlon witb
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opposite exterior surfaces of the walls 73 b~ reason of opposed,
generally aligned~ apertures 84 and 86. Aperture 84 pe~mits
pressurizatlon of chamber 82g as will become apparent, while
aperture 86 permits the formation of a drop of serum in response
to the pressurization of the chamber 82.
. - More specifically, cavity 64 comprises two pairs of
opposed walls 72 and 73, end wall 74, and intermediate wall 75.
Walls 75 and 74 have passageways 76 and 78 in which the separation
device 40 can be inserted with.serum-collecting end 48 proJecting
into chamber 82. To give gravity assist to the flow of serum
out of device 40 when ~rangible member 52 is punched through,
passageway 76 is centered in its wall 72 while ~assageway 78
is located slightly above the center line 80 of cavi~y 64,
giving a pour-out angle of a which may be as large as lO degrees.
; The dispensing chamber 82 is defined by wall 75, an
` opposed wall 88 in which aperture 68 is formed ~or plunger llO,
and extensions of walls 72 and 73 which form the exterior surfaces -
of the frame 62. This chamber preferably incorporates those
.~ features disclosed and claimed in the commonly-owned application of
R. Columbus, Canadian Ser. No. 243,828 filed on January 20, 1976,
entitled "Gas Pressure-Activated Drop 3ispenser," and comprises the
¦ ~ollowing: an end closure wall 92 with opposed faces 93 and 94,
:I Fig. 5, a cavity 96-in face 92, the opposed side walls 75 and 88-~ extending from face 93 of wall 92, and a specially constructed.drop-
forming platform 102 isolated from the rest of face 94 of wall 92,
.~ aperture.86 being generally centered in the platform.
:~ Recause the preferred use of the invention is to
! dispense a.plurality of drops, one at a time, for analysis,
¦ it is essential that the chamber 82 have a capacity sufficient
:1 30 to accommodate all the drops of serum to be tested without
. - refillingO Specifically, due .~o the number of tests normally
.r~n on a single sample, the compartment preferably has a
capacity which is equal to at least about 100 1, and preferably
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up to about 1000 ~ 1. The loNer amount of this range would be
used by patients having a limited blood supply, such as infants.
As also is disclo~ed in said Columbus application~
the platform 102 is generally a flat surface and can be
in a wall sur~ace which is part o~ wall 92 but is
isolated from the rest of the container by a notch or groove
104. Details such as these and others are illustrated
best in Fig. 5. Alternatively, another embodiment, Fig. 6,
features the formation o~ platform 102 as a separate wall
surface joined to the wall 92 by sloped walls 108 to form a
tip. In either embodiment, there preferably is a vertical
separation of the plat~orm ~rom the ~ace g4 by a distance
"h", and in Figs. 4 and 5, groove 104 preferably has a
mlnimum width "w". Both of the~e preferably is such as to
prevent a drop of blood sera from spreading from the plat~orm
to the remainln~ chamber portions prior to drop transfer.
Such drop spreading would 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 ad~acent to platform
102, that is the lnner wall~ of groove 104, Fig. 5, or the
walls 108, Pig. 6, preferably slope away from a line lQ6
along which the force of gravity acts when the drop is formed~ by
an angle ~ which is between about 0 and about 15 degrees. Negative
angle~ are also usable. Any slope greater than thls will encourage
the drop formed on the platform to spread up the walls into
groove 104, or up the walls 108, Fig. 6, thus interfering
wlth-the proper drop slze and drop removal. The sur~ace of
the platform 102 terminates in relatively sharp edges 109,
whlch are de~ined by the platform surface's 1ntersection
` with the walls of groove 104~ or with walls 108. The surface
connection provided by the walls of cavity 96 to aperture 86
may be ste~ped down, as in Figs. 4 and 5, or smooth ~s shown
ln Fig. 7.
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To insure that blood serum of the types commonly
received from patients are properly dispensed as a drop from
plat~orm 102, ln accurate micro-amounts, it has been determined
further that the chamher ~2 preferably has the additlonal
following propertles:
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1) Aperture 86 pre~erably has a maximum dimension at
the exterior surface o~ plat~orm 102, measured transversely to
Yluld flow therethrough, which is less than that which will
permit ~low of blood serum under the in~luence 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 sur~ace tension of ~etween about 35 dynes/cm and
about 75 dynes/cm, it has been found that the maximum dimension
should be between about 0.025 and about 0.046 cm. This dimen-
sional range appears to be operatlve even when the relative
viscosity is as low as about 1.2 cent~poises and is as
high or higher than about 2 centipoises.
The upper value can be increased lf the head o~ Muid is cor-
respondingly decreased as would be the case i~ the contalner
diameter was increased. A typlcal head of fluid for such a
maxlmum aperture dimension is 2.29 cm. A particularly useful
embodlment is one in which the aperture is generally clrcular
ln shape, with the circle diameter being 0.038 cm.
2) It is also pre~erred that the intersection of the
aperture with the plat~orm surface be essentlally a sharp edge,
l.e., havlng a radlus o~ curvature no greater than about 0.02 cm,
Further, the platform should be ~ree of protrusions such as portions
of ~lashing9 which would proJect elther away from the platform or ~n-
to the fluld passageway. Wlthout such precision in the formation of
the aperture, capillary e~ects would be created tending to cause
premature fluld flow.
3) The transitlon zone between platform 102 and the
connecting sur~ace such as wall 108 define3 an edge 109 which
pre~erably ls su~flciently sharp as to prevent the tendency o~
the serum drop to climb up the wall 108 or gropve 104 under the
lnfluence o~ sur~ace ten~lon. For the range of ~lulds anticipated,
it ls pre~erred that the maximum radlus o~ curvature to achieve
such an effec~, does not exceed about 0.02 cm.
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The effect o~ the preceding features is to confine the
drop dispensed from the contalner 30 to ~he surface of the
platform 102. It will be appreciated that the entire surface
of the platform is contacted 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 about 0.018 sq. cm. for a 30 ~1 drop. This represents
a range in platform diameter, between edges 109, 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 a
gi~en drop volume and platform diameter by either 1) ~orming a
downwardly pro~ecting rim around edge 109, 2) making the platform
sur~ace concave, or 3) roughenlng the surface of platform 102.
Without such roughening, i~ has been found that a preferred
~urface smoothness is between about 1 to 30 RMS.
To assist in drop detachment and to minlmize protein
agglomeration ln aperture 86, the platform 102 of the embodiment
o~ Fig. 5 pre~erably has a cross-sectional thlckness, measured
along a plane extending perpendlcular through the platform, which
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2a is no greater than about 0.025 cm. A particularly useful
thickness 18 about 0.0127 cm. The effect o~ such a construction
is to minimize the neck of fluid connecting the drop to the main
volume in compartment 82. This ln turn permits rapld detachment
with li~tle secondary flow out of the container. Alternatively,
Fig.:7, aperture 97 can be such as to blend into aperture 86 by
a smooth wall which obvlates the need for a separate wall thickness
ln the platform. In such a case, it is preferable that the dimension
~or the aperture 97 Or compartment 82 be considerably greater than
that Or aperture 86, to avoid presenting to the serum a long
constriction capable o~ protein agglomeration. This can be
achieved by an angle Y, Flg. 7, of converslon from aperture 97 to
86 whlch is no less than about 5.
.
, .
-16-
t ~4~6~
All of the above features can be obtained by forming
the chamber walls out of copolymers such as acrylonitrile-
butadiene-styrene (ABS), and polymers such as acetal, poly-
propylene, polystyrene, high density polyethylene, and poly-
esters.
Considering now plunger 110, Fig. 4, it comprises a
projectile-like body having opposite ends 112 and 114, each end
being hollowed out to form a cavity 116 and 118, respectively,
separated by a frangible portion 120. End 112 is fur~her
shaped to provide a sharp point 121. Fins 122 and 124 are
provided on the sides of the plunger, dimensioned to give
to the plunger a sliding fit within aperture 68 along an axis
extending generally perpendicularly to sheet 52. When so
mounted, portion 120 is generally parallel to frangible sheet
52, to permit by-passing of chamber ~2, described below.
- Cavity 116 ls provided with at least one passageway
130, and-the finsi 122 and 124 should be keyed to aperture 68
so as to always orient passageway 130 downwardly. The end 70
of the container 60 should overhang the plunger 110, with
protective lips 132, so as to protect the plunger against
accidental actuation.
I . , ~ , . .
j , . -
.
I
. .
.
- ol7--
1 " ' ' - . ' ` - '
In operation, ~ig. 8, the plunger 110 is displaced
~nwardly by impinging end 114 with an implement 134 having
sufficient force to cause fran~ible member 52 to break and
open under the impact. Alternatlvely, the plunger can be
actuated by hand. The serum S then pours out of the separation
device 40 into cavity 116, through passageway 130 and into the
chamber 82 where the constric~ion at aperture 86 impedes further
flow. Cells C are retained in device 40 by plug 30. Pressuri-
zation of chamber 82 is achieved by placing in sealed position
over aperture 82 a source of air pressure 140. Sealing is
achieved by means such as a rib 142. Sufficient lncrease in
pressure is provided by source 140 within chamber 82 as to form
a single drop of serum on the platform. A suitable substrate
150 can then be raised into positlon to remove`the drop for
clinical analysis. Preferably, after each drop, chamber 82 is
vented to the atmosphere, such as by lifting source 140 from
aperture 84, to permit the use of a uniform-pressurization for
subsequent drop dispensing.
As reported in the a~oresaid Columbus application,
it has been ~ound that a chamber 82 constructed as described
above, when the contents are appropriately pressu~ized,
repeatedly will give uni~orm volumetric drops of blological
fluid, such as blood sera, even when the relative viscosity,
surface tension and total proteln content varies drastically
as is characterist~c of blood sera drawn from diseased as well
~` as healthy patients. Table 1 sets forth typical results in
the dispensing o~ a variety o~ biological fluids. "~" represents
the arithmetic mean, while "COV" is the coefficient of variation
as is commonly used in statistical analysis. The variation of
only about 2% from the mean insures that repeated drops have
about the same volume. Thls accuracy is achieved not only for
blood serum, but also for other biologlcal fluids such as Ringer
solutions and water. Such control of volume is essentiaI to insure
that the same potential for the tested component exists in each drop.
-18~
~ ~4(~:~L69
~o C _ O~ _ ~ r~l~
O 00 :~ ~ O O o N N
aR~o ~o ~o ~ O _~
~ ,~
h O ~
U~ _I O O O C;~ .-1 0
l C~ _~.`
C ,~ 1O~1O O ~ ~ C~l
c~Z h ~ Xr~ ~ ~ _,
~ E~
i _ ~ _. =_ _ ~ _
-I ~ ~
~ ~ O I~ ~ ~ ~ ~
r~ ~ ~ e ~ r~ .
:~ ~4 h ~ _~ O o _~ o _~
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~ ~ ~ __
P~ ~ o ~
1 a) o)
a :~ ~ e 0~ u~ ~ ~ ~ ~ o
~ ,1 ~ h QJ ~ u~ .
~ ~ ~ ah~ e ~ -~ ~ -~ 0 -' ~
~ o _I h
~ ~ -- co A
., ~ ~ ~ ~ ..
. o ~ ~ ~ _
O
~ _I ~J ~1 _~ ~ 1~ N O N
_ _ =_ ~ _ _0
/ O ~ ~
~ / U~ ~ ~ ~
~ / ~ e ~ ~ e
,, ~. r~ ~ .,` o o e ~ e ~ :~ e
r~ ~. c ~-,, ~ O ~ ~ ~
., ~ ~ ~ ~ v~ r4 -~ o ~ , ~ ~_
E~ ~ ~ ¦ O ~, ~ r~ O l ~' I x
~ ~ a) ~ o ~ r~ r~-
/ h e v~ I r~ a u~ u~
/ ~
,. , a r~_ __ . __
:
.~ -19-
,
. .
:. :
In the preceding table, the blood sera was obtained from
. whole blood samples taken on a random basis from various
human patients. The Ringer Solution was isometric 0.9% NaCl
in water. The "calibrated reference serum" was "Versatol",
provlded by General Diagnostics, a division of Warner-Lambert
Co. The assay for "Versatolt' serum is given in Table 2.
Table 2
"Versatol" Serum
. Constituent Amount
Bil1rubin 0.5 mg/100 ml
Calcium 10.2 mg/100 ml
Chloride. 103 mEq/L
Cholesterol, total 170 mg/100 ml
Creatinine 1.7 mg/100 ml
Glucosel 81.0 mg/100 ml
Iron 143 mcg/lOO ml
Magnesium 2.2 mg/100 ml
Pho~phorus, inorganic 4.0 mg/100 ml
. Potassium 5.0 mEq/L
2a Protein Bound Iodlne ? ~ 2 mcg/100 ml
Sodium, 140 mEq/L
-TI~C.......................... 397 mcg/100 ml
Total Nitrogen . 1192 ml/100 ml
,: Total Protein2 . , 7.1 gm/100 ml
Urea Nitrogen 12.2 mg/100 ml
Uric Acid 3.3 mg/100 ml
Actual glucose recovered by methods such as glucose oxidase
or Nelson-Somogyi.
2Calculated as ~(Total Nitrogen)-(Non-protein nitrogen)] x 6.25.
_29.
' .
- ' .
. ~ ~
6~3
The ion-free calibrated re~erence serum was "Chemvarion" 9
produced by Clinton La~oratorles. Table 3 sets for.~h the
assay for this test fluld.
Table 3
"Chemvarion"
Range Found Mean
Constituent(per 100 ml) (~er loo ml)
NPN N.A. 36 mg
Total NitrogenN.A. 960 mg
Total Protein(TN-NPN) x 6.25 5.77 gms
Protein-bound Iodine 2.5-2.8 mcg 2.65 mcg
Cholesterol 135-149 mg 142 mg
: Iron, Total 79-106 mcg 92 mcg
Magnesium N.A. nil
Copper . 34-43 mcg 39 mcg
The following determlnatlons were made by adding
back pure standard concentrates in recovery
experlments
Sodium -- nil
2C Potassium -- nil
Calcium , -- nil
Chlorlde -- nil
: Urea Nitrogen -- nll
Uric Acid -- nil
. Phosphorous 0.1-0.3 mg 0.2 mg*
Glucose - -- - nil
. . Creatinine -- nil
~ Lithium . -- nil
: *Probably protein-bound and llberated during determination.
.~ ' ' '" . . . .
.' ' : ,
., ' ' '' ' ' "
-21
,' ~
- .
To permit pour out o~ serum without going through
dispensing chamber 82, a pour-out tube 160 can.be forced through
~rangible portion 120, as by hand, Fig. 9~ Such a tube has a
passageway 162 extending its length, and a sharp, polnted end
164. As the tube is forced through portion 120 and sheet 52,
it carries plùnger 110 suf~iciently far into end 48 of separation
device 40 so as to cover passageway 130. The serum S exits then
through passageway 162.
Container 60 preferably is used ~or the entire sequence
of blood collection, centrifuging, and dispensing. Thus, the
blood stays with the same container for its entire processing.
The centrifuging requires that it be spun about a point "X",
Fig. 4, delivering a force F along axis 44.
To permit patient ldentification o~ the container 60
for this entire processlng, a label 170 can be provided on, or
recessed into, any exterior sur~ace. To permit rea~y stacking
of the container, and/or machine handling, opposite walls 73 are
rormed one with a groove 172. and the other with a rlb 174, both
. extending the full length of the contalner. As ls apparent, the
20 size and shape of the groove and rib should be such as to permit
then to ma.te with a rib or groove, respectively, o~ a second
container.
:~ It will be appreclated that container 60 can be used
to dlsp~ense slngle-phase blological flulds from container 40,
merely by removing the gel 30 and the mandrel 32, if used,
~rom the compartment defined by walls 42 prlor to collection
. o~ th~ fluid
. . Valved Container
Turning now to the remaining Flgures, there is
.lllu~trated an alternate embodiment ~or the blood separation
de~ice and serum dispenser wherein all the parts can be
integrated into a single, unltized body, and the temporary
; : -2 ~ ~
:, . '".' ~, ~
~463~6!3
blocking means is replaced by a valve. As used in this
application, the term "valve" means a member by which the flow
of fluid ~hrough a passageway may be blocked, permitted, or
otherwise regulated by a movable part that shuts, opens, or
partially obs.tructs, respectively, the fluid flow. Such a
- member is in contrast to the frangible member of the previous
embodiment, inasmuch as a valve can be reclosed after it is opened.
Parts similar to those previously described bear the
same re~erence number to which the distinguishing su~ix "a" has
been added.
` -22a-
- . . .
Thus, as best seen in Figs~ 10-12, a uniti~ed processing
container 60a is provided, comprising a body having two opposite
ends 66a and 70a9 and exterior opposed walls 72a and 73aO Extending
into the container 60a from end 66a is a blood separation compartment
42a, open at both ends and having a generally tubular shape with an
axis C~4a~ Fig. 12. The outer end 46a of compartment 42a can be
enlarged to accommodate a septum 52a permanently secured thereto.
Compartment 42a terminates in inner end 48a at a locator surface
175a, Fig. 12, which coincides with the walls of a second compart-
ment or dispensing chamber 82a to define a passageway 176 between
the two compartments. Chamber 82a has a longitudinal axis 106a
extending generally perpendicular to axis 44a. As in the previous
embodiment, a movable plug 30a is positioned in the serum-collecting
end 48a of compartment 42a, and may optionally include a mandrel 32a
Fig. 20. Preferably, the plug 30a comprises a gel, the nature of
which is the same as in the previously discussed embodiment, Fig.
4, as in the mandrel if used. As is seen in Fig. 12, the
; centrifugal force F is again applied against the plug 30a
towards the end 46a accommodating the closure means 50a.
Chamber 82a extends from an opening 180 in wall 73a,
past passageway 176 to a second locator surface defined by an
end wall 92a. Generally centered in the end wall is a cavity 96a
defining a third compartment in fluid communication, Fig. 12,
with the other two compartments. Wall 92a is further provided
with a platform 102a which is here shown as joined to wall 92a
by sloping walls 108a as in Fig. 6. The wall 92a and its plat-
form 102a preferably are recessed with respect to a ridge 177
surrounding the platform, to protect the surface of the platform
from contamination. Alternatively, the platform may be
constructed as shown in either Figs. S or 7. Regardless of
the form of the cavity 96a, the chamber 82a and particularly
the platform 102a, aperture 86a, and angle ~, Fig. 12,
., .
;; -23-
have the same properties and values as enumerated in detail in
the previous embodimentg except that the platform 102a can be
recessed with respect to the ridge 177~
- The exterior surfaces oP the container 60a can have
the same add'itional features as shown in the embodiment of
Flg. 4. That is, a patient identification marker 170a can be
placed on an exterior sUr~ace, and groove 172a and rib 174a can
be formed along the full length of opposed walls 73a. Any suitable
' mating shape can be used for the groove and r~b. In addition~ a
notch 190 extends circumferentially around the container 60a,
concentric with axis 44a, Fig. 12, the notch being located generally
~in alignment with the gel 30a, and extending toward compartment
42a. The function of the notch is to permit the contalner 60a
to be broken by snapping Off the chamber 82a. In the manner, serum
' obtained in compartment 42a can be poured off, or otherwise aspirated
away, without requiring drop-by-drop dispensing through chamber 82a.
A concave surface 195, Fig. 10, can be provided in end
wall 70a for the purpose of ready identificatlon and for machine
!
centering or handling of the container, if desired.
To control the flow of serum from compartment 42a into
compartments 82a and 86'a, blocking means in the form of a valve
¦ ' 200 is seated'within chamber 82a, having a portion removably
' blocking passageway 176. More spec~ically, to obtain selective
' ~low of' serum from compartment 42a, the valve comprises, Fig. 14s
- a body 204'having a-face plate 206, a valve stem 208 extending
1' ~rom body 2~'4, and a supporting leg 210 also extendlng ~rom the
¦ valve body at a position generally opposite to stem 208. The
I stem and leg are spaced apart by an opening 211 which is at
I least as large as passageway 1769 Fig. 10.
¦ 30 ~he body's exterior sur~ace is deslgned to mate
'within chamber 82a. Thus a prererred shape'of chamber 82a and
body 204 is generally cylindrical. The valve is furthe-r mounted
` for rotation within chamber 82a about axis 106a, Fig. 12, a
'. ' ` ~ '
-24-
.
circumferentially~extending rib 212 in body 204 being provided
to rotate within a mating groove 214 in chamber 82a (Fig.
; 12). To permit pressurized air to be delivered into valve
200 and thus into chamber 82a, an aperture 84a extends
through plate 206. A suitable inter~ace, such as a rib, can
be provided as a seal in a manner similar to ~he embodiment
of Fig. 8. To provide a rotary drive for valve 200, at
least one, and preferably two, cavibies 220 are formed in
plate 206 to mate with a driving member, the cavities being
offset from axis 106a.
As means for sealing off the passageway 176, the
stem 208 is provided with a closure member 230 pro;ecting
radially outwardly away ~rom the valve, of a shape and si~e
as to fit into and close the passageway. To permit opening
!
of the valve merely by rotating body 204, the member 230 is
- preferably ~lexible enough as to be compressed by such
. .
rotation, whereby it will clear the wall of chamber 82a just
.
outside o~ passageway 176. Typlcal materials having such
properties include ~oamed or solid elastomers, such as
silicone rubber, which may be adhered as by suitable adheslves
directly onto the stem.
I TQ bias the closure member against passageway 176,
I it is preferred that the stem 208 and leg 210 be formed so
~1 - . .
l as to pro~ect outwardly a distance which is slightly larger
than the diameter of chamber 82a? whereby the stem and leg
are pressed together when the valve 200-is forced lnto the
I chamber. Alternativelyj leg 210 may extend generally perpen-
I dicularly to ~ace plate 206, as seen in Fig. 15.
¦ By the above means, a sufficient seai is provided
. ,
~or passageway 176 as to permlt compartment 42a to be at
I least partially evacuated, if deslred, and maintained in
1 .
I this condltion prior to use. - Blood may easily be drawn into
i ~ such evacuated compartment when a cannula is inserte~ into
i septum 50aO
25-
Figs. 15 and 16 illustrate an alternate embodiment
of the valve, wherein the closure member protruding from
stem 208 has been eliminated. Parts similar to ~hose previously
circum~erentially-extending described bear the same reference
numeral to which the dlstinguishing suffix "a" has been
added. Thus, valve 200a has a body 204a, a f~ce plate 206a,
a stem 208a and a supporting leg 210a, as be~ore. However,
in place Or the closure member, the stem itse-lf is molded so
as to pro~ect even ~urther away ~rom the body 204, and is
further provided ad~acent to~the ~uncture of ~he stem with
tne bodyj with wings 240 which flare outwardly from the
body. The Plexibility of the wings 240 and of the stem are
sufficient to permlt the valve 200a to be compressed and
forced into chamber 82a, where the compressive forces act to
unirormly load and seal the stem against passageway 230.
Figs. 17-19 lllustrate still other embodiments of
the invention wherein yet other means are provided for
' selectlvely sealing passageway 176. Parts similar to those
previously described bear the same reference numeral, to which
the distinguishin~ suPPlxes "b", '1c" and "d" are applied. Thus,
l in Fig. 17, valve 200b is constructed as in Fig. 14, except
that closure member 230b comprises a flexible grommet lnserted -
into an aperture 250 Pormed in stem 208b. The grommet's size
I
~¦ is such as to block pas~ageway 1?6 when it 1s aligned, by
rotation of the valve, with the passageway. In Fig. 18, valve
.j . , .
~i 200c comprises a ball 256 held in aperture 250c by a clip 258,
one end 260 of which is secured over the end of stem 208c.
Elther the ball or the clip, or both, ~s sufficiently resilient
l . .
as to permlt the ball to be forced out oP passageway 176 when
! 3 -the valve is rotated to its open position. In Fig. 19, the val~c
.
200d is constructed as ln the embodlment of Fig. 14~ there
being however, no protruding closure member on stem 208d.
-26-
-
Instcad~ a coatin~ 270 of an adhesive capable of being activated
~y ultraviolet exposure, ls coated over the exterior surface of
the stem~ so that passageway 176 can be sealed. after the stem is
positioned thereacross. Typical of the adhesives which can be
used as acrylic-modified urethane resins havin~ unreacted ~so-
cyanate groups comprising at least about 2.0% py weight of the
zesin. The adhesive disclosed in British Pate~ No. 1~147~732 is
also believed to be suitable.
In addition to the readily apparent advantages of
valve 200, yet other advantages are that it provides a maximum
or enhanced flow of serum throu~h passageway 176 into chamber 82a.
That is, the opening 211 between the stem 208 and leg 210, in all
i
the valve embodiments, is as large as the passageway 175 (Fig. 10),
and therefore as large as the diameter of compartment ~2a. Also,
the valve can be reclosed after the serum passes into chamber 82a,
so as to present a smaller volume of air which has to be pressurized
as by a device such as source 140 of the previous embodiment.
The above construction permits the container 60a to be
used as an evacuated container, the same unitized body functioning
1 20 first as the blood collector, then the separator, and lastly the
¦ dispenser, all without requiring trans~er to a separate container.
¦ In addition, it is contemplated that the blood can be
, collected without first providlng a partial vacuum in ~
I compartment 42a, and further that an alr vent or aperture-
300 can be formed in-wall 73a, Fig. 20, to avold air-
buildup as blood is ~orced into compartment 42a. To
prevent leakage of serum out of the hole, while still permitting
a~r ~low, the vent 300 can either be filled with alr permeable
material, not shown, such as a liquid-impermeable membrane,
'
'
.
or a cellular material the pores o~ which will readily plug
when serum flows into it. Such pores, which provide the
effective air passageways, should be sufficiently small as
to resist blood flow therethrough under- the radially outward
pressure commonly encountered during centrifuging. Such pressures
have been found to be, for example, about 1.245 x 105 dynes per
square centimeter. Alternatively, the vent may be cut on a
diagonal axis which is non rectilinear to the compartment
axis, as shown in phantom, rather than a radius, to further
discourage blood leakage during centrifugation. Still
further, the plug 30a can prevent leakage by strategically
locating the inner end 302 of the vent which opens into
compartment 42a. That is, the blood drawn into ~he container will
normally have a serum content occupying a sp~ace having a length
between about 35 and about 60% of the free length of compartm-
ent 42a, thus insuring that the plug 30a will move to this
- position. Still further, exterior covers, such as tape, can be
posltloned after the sample is drawn, to prevent leaka~e.
The container 60a as descrlbed above can be made
Of synthetlc rigld polymers, or "plastics". If compartment
42a is to hold a vacuum, a relatively non-porous synthetic
I polymer 1s prererred, uch a~ "Saran" vinyl chloride-vinylldene
¦ chloride copolymer manu~actured by Dow Chemical Company.
- -
~,. . ' ' ,,~ .
'
'-'' '' ' .'
. .
.
~ -28-
.
',
. ' ' ' ' , .
.
~ 4~
It will be appreciated that, by reason of the
above construction, the container 60a can have a minimal
s,.ze, and can be formed of materials such as various plas-
~ s whlch will permit it to be disposed of, a~ter a single
; use. A typical length of the container would be, from end
66a to end 70a, only about 5~5 cm. This can be shortened
if, for example, a retest container is to be supplled,
because in that case the serum will already be separated and
plug 30a can be eliminated. Such a container could also be used
to dispense biological fluids other than serum. Even i~ a
non-plastic s-urface for the walls of compartment 42a is
required for any reason, a cylindrical liner, such as a
glass sleeve, can be readily incorporated.
A further advantage found with the devices described
above is that the delay required for coagulation can be reduced
below that necessary in using devices such as those shown in Fig. 1.
Yet another advantagé of the container 60a is that lt
will readily fit within conventlonal centrifuges and/or syringes
wlthout requiring the redesign of this related equipment.
Z0 . It wlll be appreclated that the valve and dispensing
chamber along wlth its.platform, can be combined to form a detached
I . ' . ,
device which can be readily lnserted into or-mountedlover a serum
container after the serum is separated from the blood cells, or
comblned wlth a container prov~ded wlth serum ln any fashion.
~ ~ These embodiments are lllustrated in Figs. 21 and 22. .Parts
l similar to those previously described bear the same reference
I numeral to which the dlstinguishlng suffixes "e" and "f" have
; been added. Thus, Fig. 21, the processing container 60e com-
- prlses a 8erum separation tube 40e open at both ends, a septum
50e closing one of the end3 at the blood inlet and.cell col-
lecting portion ad~acent.end 46e. At the serum-collecting
. .
portion adJ.acent end 42e, a`dlspenslng apparatus has been
.
. . -29-
inse~ted, either before or after serum centrifuging~ to permit
dispensing of the serum. The details of the dispensing chamber
82e, the valve 200e and the platform 86e are the same as des-
cribed for the preceding embodiments. The whole assembly fits
into end 42e by means of a neck portion 310 having an end 312
which ~elescopes well into the end 42e, and an end 314 adjacent
valve 200e. The serum passageway 17`6e traverses neck portlon
310 ~rom end 312 to end 314, which is blocked by closure member
230e. To seal the neck portion and the entire dispensing
apparatus within tube 40e, ribs 320 project from the neck
portion into c'ontact with the tube.
Alternatively, Fig. 22, the chamber 82f containing
the valve 200~ and the neck portion 310f can be mounted over
t,he exterior o~ the tube 40f so that end 42~ of the container
fits within the neck ad~acent end 314f . The onIy change
necessary is of course to mount the sealing ribs 320b on the
inside of the neck portlon 310f, rather than the outside.
~ hese embodiments can be preassembled before use,
in which case' the ribs must ~it tight enough to the tube to
permit air evacuation of the tube. The pha3e separation gel
(not shown) is then inserted ad~acent the closure member 230e or f
the valve. In such a case use of container follows substan-
tially the same procedure ~s descrlbed for previous embodiments.
Operation of the valve and dispensing chamber also would be
exactly as described above.
:,` . J
,Other suitable mod1fications of the previous
embodiments include any suitable means to augment the serum
separation'or the ~low of ~erum from the separation compart-
, ment to the,dispensing chamber when the valve is open. For
~ 30 example, increased surface area in the walls Or the separation
¦compartment wlll increase the speed of clotting prior to
I, serum separation. Also, the septum end of the contalner can
¦be tllted up at the dlspens~n~ station to augment serum flow.
--
Turning now to Fig. 23, there is ill,ustrated an
lntegral embodimen~ i~ which ~he rotatable valve is positioned
to rotate about an axis parallel ~o or coincident with the axls
of the serum separation tube. Parts similar to those previously
described bear the same re~erence numeral to which the dis-
tingulshing--suff~x "g" has been added.
A unitized container 60g i~ provided with a serum
separation compartment 42g havlng an axis 44g,~ the compartment
end 48g belng inclusiye, in thl~ case, of the interior of the
dispen~ing chamber 82g. An improved septum 350, described here-
inafter, i9 positioned at body end 66g, while the rotatable val~e
200~ ~lts within chamber 82g. The valve is identical to that
described previously, except for the modifications necessary to
permit lt to rotate about an axi~ parallel to axis 44g. Thus,
the rlb 212g mate3 with a groove 214g in end 70~ of th'e unit,
rather than ln the top portlon. Pressurizing aperture 84g is
~ormed in the wall 73g of container 60g, rather than ln the plate
206g of valve 200g. Means 360 are then provided on leg 210g to
~eal off aperture 84g until the valve is rotated, and such mean~
can be a closure member identical to closure member 230g mounted
on valve fffftem 208g, a8 descrlbed in the previous embodlments.
Clo~ure member 230g serves in thls embodiment to
temporarlly block or 3eal Or~ the dtspensing platrorm
102g, and wall 92g from which the platform depends may:be
rece~sed to acoommodate member 230g. To as3ist in providing a
vacuum seal, the stem 208g and the leg 210g each have a rib 364
protrudlng away from the valve body, and a matlng groove 366 ls
.
~ormed ln the walls o~ compartment 42g to receive the rlbs.
.
In opèration, the partitloning gel 30g i3 located
in8ide the chamber 82g and between the valve 3tem and valve leg,
ad~acent to valve plate 206g, prior to centrifuglng, 80 that
- chamber 82g 18 used to accommodate part of the sample as
collected and at lea3t a portion o~ the serum after centrifuging.
-- ~he ~el 30g 1~ again posltloned in the serum-collec;ting portlon
ad~acent compartment end 48g. gs~ be~ore, the,centri~ugal force
is applied along axis 44g ~rom the chamber 82g toward end 66g,
causing the 6el ~o msve ou~ o~ chamber 82g into compartment 42g
where it separates the serum ~rom the blood cells. This provides
I the advantage o~ shortening the overall length of the~container
- 60g. Dispensing of separated serum~-is achieved by rota-ting the
valve 200g and pressurizing ~he interior of chamber 82g ~hrough
. aperture 84g, as described for the preceding embodiments.
Septum 350~ Fig. 23, whlch can be used in any of
the embodiments o~ the invention, is provided with means to
, 10 improve its sealing performance, particularly during centri-
¦ fuging. That is, as with conventional septums it has a neck
portion 352 and a head portion 354. However, the ~ unction o~
the neck and head portions ~eatures an annular undercut or
groove 356 extending the entire circumference of the septum-
Thls groove permits the formation of a more flexible lip 358
in neck portlon 352, and therefore extra sealing power against
the lnner wall af compartment 42g, insuring that the seal will
be maintained when the vacuum is drawn on the bod~ 60g, and
when the centri~uge force is directed against the septum in a
direction tending to ~orce the septum out.
. It wlll be appreciated that the embodiment of
Fig. 23 can al30 be used as a detached dispenslng chamber adapted
~or lnsertlon into or over a serum-containing compartment or tube in
the manner shown in Fi~s. 21 or 22, before or after centrifuging~
The ln~ention ha~ been defined ln detail with
reference to certain preferred embodlments thereof, but it
will be understood that variations and modifications can
be effected within the splrit and soope of the lnvention.
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.. . .
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