U.S. patent number 3,771,965 [Application Number 05/136,750] was granted by the patent office on 1973-11-13 for biological fluid sampling apparatus.
Invention is credited to Ralph R. Grams.
United States Patent |
3,771,965 |
Grams |
November 13, 1973 |
BIOLOGICAL FLUID SAMPLING APPARATUS
Abstract
A biological fluid sample tube assembly includes a collection
tube with a closure member sealing one end of the tube. The closure
is adapted for penetration by a cannula needle for delivery of a
fluid sample through the cannula and closure member into the tube.
A processing member, such as a scraping member, is movably
supported within the tube and is movable by application of force
externally of the tube in order to perform a desired processing
function without opening the tube. Thus the member can scrape
clotted blood or other solids, which may have coagulated while the
sample tube was awaiting further processing, to a desired location
in the tube out of the way of the liquid sample to be evaluated.
Preferably the scraping member is designed for axial movement
within the tube from a position adjacent the closure member to a
position at the other end of the tube in response to the
centrifugal forces applied when the tube and its sample are placed
in a centrifuge for separation of solid particles, such as the red
blood corpuscles in a blood sample, toward the end of the tube
opposite the closure member.
Inventors: |
Grams; Ralph R. (St. Paul,
MN) |
Family
ID: |
22474206 |
Appl.
No.: |
05/136,750 |
Filed: |
April 23, 1971 |
Current U.S.
Class: |
422/72;
215/DIG.3; 494/16; 600/577; 422/918; 422/550 |
Current CPC
Class: |
B01L
3/5021 (20130101); A61B 5/154 (20130101); A61B
5/150732 (20130101); A61B 5/150389 (20130101); A61B
5/150351 (20130101); G01N 33/491 (20130101); A61B
5/150755 (20130101); A61B 5/150496 (20130101); A61B
5/15003 (20130101); Y10S 215/03 (20130101) |
Current International
Class: |
A61B
5/15 (20060101); B01L 3/14 (20060101); G01N
33/49 (20060101); G01n 033/16 () |
Field of
Search: |
;233/26,1R,3 ;23/259,292
;134/8 ;210/361,359,183,83 ;259/124 ;15/104.05,236 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Krizmanich; George H.
Claims
I claim:
1. A biological fluid sample assembly comprising an initially
closed fluid sample collection container for receiving a biological
fluid sample from a body portion of a patient and in which the
biological fluid may be centrifuged to separate solid from liquid
portions of such fluid, said container having a longitudinally
extending interior wall surface portion of uniform cross section, a
cannula-penetrable closure member sealing one end of the container,
at least a portion of the closure member being adapted for
penetration by a cannula-needle for delivery of a biological fluid
sample from a body portion of a patient through the closure member
into the container, and a scraping member within the container,
said scraping member having a peripheral scraping edge portion
slidably engaging the uniform interior wall surface portion for
relative scraping movement of the scraping member edge portion
along such surface, said scraping member also having releasable
means normally holding the scraping member at a first position in
the closed container adjacent the closure member during normal
handling of the container while receiving such sample and holding
the sample for further processing, said releasable means being
constructed and arranged to permit movement of the scraping member
away from its first position in response to and during application
of such centrifugal forces to the assembly externally of the
container as required to separate said solid and liquid portions,
and said scraping member including means providing a longitudinal
passage positioned inwardly from the scraping edge portion for free
relative movement of fluid longitudinally from one side of the
scraping member to the other when the scraping member moves away
from its first position, said scraping member thereby being
responsive to the external application of such forces for movement
away from such first position during the separation of the solid
and liquid portions without the necessity of opening the
container.
2. A fluid sample assembly according to claim 1 in which said
releasable means includes interengaging portions on said scraping
member and container, said interengaging portions having relative
dimensions and locations providing frictional retaining engagement
between them normally retaining the scraping member at its first
position, while permitting relative movement of the scraping member
away from said first position in response to said centrifugal
forces.
3. A fluid sampling assembly according to claim 1 in which the said
releasable means includes a releasable connection between said
closure member and scraping member.
4. A fluid sampling assembly according to claim 3 in which said
closure member and scraping member each include respective portions
of identical material and said releasable connection consists of at
least one connecting portion of the same material integrally
connecting said respective portions, said connecting portion having
a limited cross section providing a frangible connection between
said respective portions.
5. A biological fluid sample tube assembly having a fluid sample
collection tube in which a biological fluid may be centrifuged to
separate solid from liquid portions of such fluid, a
cannula-penetrable closure member sealing one end of the tube, at
least a portion of the closure member being adapted for penetration
by a cannula needle for delivery of a biological fluid sample from
a body portion of a patient through the closure member into the
tube, and a scraping member supported within the tube adjacent the
closure member, said scraping member being movable within the tube
away from the closure member in response to and during application
of such centrifugal force applied externally of the tube as is
required to separate said solid and liquid portions without the
necessity of opening the tube, the tube having an interior wall
surface of uniform cross-section, and the scraping member having a
peripheral scraping edge portion of which the entire outer
peripheral edge fits said interior wall surface uniform
cross-section during relative sliding movement of the scraping
member and edge portion axially along the tube, the scraping member
also having a cap portion extending substantially across the
uniform cross-section of the tube in at least one position of the
scraping member along the tube, and said scraping member further
including means providing a passage inside the scraping edge
portion for relative movement of fluid axially from one side of the
scraping member cap portion to the other side of said cap portion
when the scraping member moves axially along the tube through a
fluid sample therein.
6. A fluid sample tube assembly according to claim 5 in which the
scraping member is initially positioned with its cap portion
adjacent to and substantially covering the inner surface of the
closure member for penetration of the cap portion by said cannula
needle during delivery of a fluid sample into the tube through the
closure member.
7. A biological fluid sample tube assembly having a fluid sample
collection tube with an interior tubular wall surface of uniform
circular cross section, a closure member sealing one end of the
tube, at least a portion of the closure member being adapted for
penetration by a cannula needle for delivery of a biological fluid
sample from a body portion of a patient through the closure member
into the tube, and a scraping member supported within the tube,
said scraping member being movable within the tube in response to
force applied externally of the tube without the necessity of
opening the tube, said scraping member having an annular scraping
edge portion slidably engaging the interior wall surface for
relative movement of the scraping member and edge portion axially
along the tube, said scraping member also having a cap portion
extending substantially across the uniform cross section of the
tube in at least one position of the scraping member along the
tube, and said scraping member including means providing a passage
for relative movement of fluid axially from one side of the
scraping member cap portion to the other side of said cap portion
when the scraping member moves axially along the tube through a
liquid sample therein, and said scraping member consisting of a
single tubular member of resiliently deformable material which
normally has a uniform annular cross section throughout its length,
one end of said tubular member constituting the annular scraping
edge portion of the scraping member, said tubular member having
cutaway portions at its opposite end providing a plurality of
tapered segments projecting axially at said opposite end, said
segments being deformable inwardly across the tubular member at
said opposite end and thereby constituting the cap portion of said
scraping member when the scraping member is in a position
immediately adjacent said closure member with said segments
engaging and substantially covering the inner surface of the
closure member, and the segments at said opposite end being movable
from their position constituting a cap portion covering the closure
member back toward a normal axially projecting position, when the
tubular member is moved away from the closure member by external
application of force, said tubular member and said segments thereby
constituting said means providing a passage for relative axial
movement of fluid.
8. A biological fluid sample tube assembly having a fluid sample
collection tube with an interior tubular wall surface of uniform
cross section, a closure member sealing one end of the tube, at
least a portion of the closure member being adapted for penetration
by a cannula needle for delivery of a biological fluid sample from
a body portion of a patient through the closure member into the
tube, and a scraping member supported within the tube, said
scraping member being movable within the tube in response to force
applied externally of the tube without the necessity of opening the
tube, said scraping member having an annular scraping edge portion
slidably engaging the interior wall surface for relative movement
of the scraping member and edge portion axially along the tube,
said scraping member also having a cap portion extending
substantially across the uniform cross section of the tube in at
least one position of the scraping member along the tube, and said
scraping member including means providing a passage for relative
movement of fluid axially from one side of the scraping member cap
portion to the other side of said cap portion when the scraping
member moves axially along the tube through a liquid sample
therein, and said annular scraping edge portion and said cap
portion being formed as integral portions of a single piece of
deformable material, said means providing a passage consisting of
at least one movable flap in said cap portion.
9. A biological fluid sample tube assembly having a fluid sample
collection tube with an interior tubular wall surface of uniform
cross section, a closure member sealing one end of the tube, at
least a portion of the closure member being adapted for penetration
by a cannula needle for delivery of a biological fluid sample from
a body portion of a patient through the closure member into the
tube, and a scraping member supported within the tube, said
scraping member being movable within the tube in response to force
applied externally of the tube without the necessity of opening the
tube, said scraping member having an annular scraping edge portion
slidably engaging the interior wall surface for relative movement
of the scraping member and edge portion axially along the tube,
said scraping member also having a cap portion extending
substantially across the uniform cross section of the tube in at
least one position of the scraping member along the tube, and said
scraping member including means providing a passage for relative
movement of fluid axially from one side of the scraping member cap
portion to the other side of said cap portion when the scraping
member moves axially along the tube through a liquid sample
therein, and said means providing a passage for relative movement
of fluid comprising a rupturable cap portion.
Description
BACKGROUND OF THE INVENTION
In presently known blood sample tubes, it is customary to have a
sample holder provided with a needle or cannula which can be
inserted into the blood vessel of a patient to obtain a blood
sample or a series of such samples. The holder includes a needle
portion extending away from the patient and is designed to
penetrate the closure member at one end of a sample collection tube
which is removably positioned within the holder. Thus when the
sample tube is within the holder, the closure of the sample tube is
penetrated by the holder needle for delivery of blood from the
patient through the holder needle and through the pierced closure
member of the sample tube into the interior of such tube. Some
sample tubes have been vacuumized to expedite the drawing of the
sample. When the desired sample has been collected, the sample tube
is withdrawn from the holder, and turned over to laboratory
personnel for desired testing.
Substantial time may elapse between the taking of the sample from a
patient and the actual testing of the sample in the laboratory.
During such time, some of the blood may coagulate or clot and be
deposited on the inner surfaces of the tube or closure member. For
example, if the tube has been left on its side, there may be a
deposit of clotted blood particles on the inner surface of the
closure member and on the wall portions of the tube adjacent
thereto.
In the prior art processing of such samples in the laboratory, it
has been necessary to remove the closure member or stopper and
manually insert a stick or stirring rod to scrape the clotted
material down from the walls of the container, before the sample is
placed in a centrifuge for centrifugal separation of the red cells
into the bottom of the sample tube. Failure to perform such a
scraping operation could leave the clotted materials in the upper
portion of the tube, where they might accidentally be withdrawn as
a part of a sample of clear serum and thus adversely affect those
tests which are normally performed on the clear fluid. The opening
of the sample tube, however, and the scraping operation just
described, provide an increased opportunity for infection of a
laboratory worker. The increasing incidence of hepatitis, for
example, and its presence in blood samples of patients who may not
even be suspected of having such infection, have increased the risk
that laboratory testing personnel may suffer from this disease.
SUMMARY OF THE INVENTION
According to the present invention an improved biological or body
fluid sample container assembly is provided, in which a processing
member is movably supported within a sample container and can be
moved within the container in response to force applied externally
of the container to perform a desired processing action, such as
the scraping of clotted material into the bottom of the container,
without the necessity of opening or unsealing the container. The
container is preferably a tube having a closure member at one end
adapted for penetration of a cannula needle for delivery of a fluid
sample through the closure member into the tube. The processing
member preferably has releasable means normally holding the
processing member at a first position in the container during
normal handling of the container. The releasable means is
constructed and arranged to permit movement of the processing
member away from its first position in response to the application
of substantial forces to the assembly externally of the container.
While various means for application of force externally to such a
container or tube may be used, the preferred form of the invention
includes a movable member within the tube which is moved in a
desired direction by centrifugal force, while the tube is being
processed in a centrifuge for suitable separation of its contents.
Thus a scraper member is movably positioned, in one form of the
invention, within the upper end of the tube immediately adjacent
the closure member through which a cannula needle introduces a
fluid sample into the tube. When the tube is placed in a
centrifuge, so that centrifugal force is applied lengthwise of the
tube to force clotted particles, such as red blood cells, or other
denser materials toward the bottom of the tube, the scraping member
according to the present invention is also forced axially
lengthwise down the tube and thereby carries any such materials
from the upper end of the tube toward the lower portion thereof in
order to provide a substantially clear region at the upper end of
the tube for the clearer or lighter liquid which remains in that
part of the tube following the centrifugal separation.
A preferred form of scraping member includes a cap or transverse
wall portion which extends completely across the tube and which may
be initially located close to the closure member at the top of the
tube, so that the fluid sample is introduced into that portion of
the tube below the scraping member. Subsequent movement of the
scraping member axially down the tube can thus carry along any
clotted materials which might otherwise have been deposited on the
inner surface of the closure member itself. The necessity of
opening the fluid sample tube prior to its normal processing in a
suitable centrifuge is accordingly eliminated or essentially
reduced to those special situations where some other factor
requires opening of the tube. The scraper member will remain in the
bottom of the tube after centrifuging, so that it will be out of
the way and impose no obstacle to the withdrawal of the clear serum
or other fluid from the upper portion of the sample tube.
The invention is described with particular reference to the
collection and processing of blood samples from a human
patient.
BRIEF DESCRIPTION OF THE DRAWING
The invention is more particularly described with reference to the
accompanying drawings, in which like reference characters indicate
like parts, and in which
FIG. 1 is a side elevation, partly in section, of an improved fluid
sample tube assembly according to the invention shown in
combination with a sample tube holder of known construction;
FIG. 2 is an enlarged perspective view of a scraping member of the
type shown in the sample tube assembly of FIG. 1;
FIG. 3 is a general schematic view, partly in section, showing the
positioning of blood or other fluid sample tubes in a centrifuge
during processing;
FIG. 4 is a view of the sample tube assembly of FIG. 1 after its
removal from the holder, showing the scraper member in an
intermediate position as it is forced downwardly through the liquid
in the tube, e.g., during centrifuging;
FIG. 5 is a side view of a modified form of scraper member for use
in place of the member shown in FIG. 2;
FIG. 6 is a sectional view of another modified scraper according to
the invention;
FIG. 7 is a perspective view similar to FIG. 2 of another
modification of the scraper member;
FIG. 8 is a view similar to FIG. 7, which shows the member of FIG.
7 after it has been punctured by a fluid delivery needle and moved
away from its supported position adjacent to the closure member of
a fluid sample tube; and
FIG. 9 is an enlarged view of a modified construction in which the
scraper member is initially formed as an integral part of a sample
tube closure member and is separated therefrom before or after
insertion of a fluid sample, e.g., by the forces applied during the
centrifuging of such a sample.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A body fluid collecting apparatus embodying the invention is shown
in FIG. 1. Here a suitable cylindrical holder 11, which may be of
known construction, is open at its lower end 12 and is closed at
its upper end by end wall 13 which, in turn, has a central
supporting portion 14 for a cannula or needle 16. The upper end 17
of needle 16 is adapted for insertion into a blood vessel or other
body portion of the patient to withdraw a biological fluid sample
therefrom. Needle 16 has a lower end 18 through which the fluid
sample is delivered to a sample tube assembly 19 through the
closure member 20 at one end of the sample tube 21.
Closure member 20 has a main body portion 22 which fits resiliently
within the upper open end of tube 21 to provide a closure and seal
for the tube. Flanges 23 on the upper end of member 20 provide a
limiting means to determine the position at which the stopper or
closure member fully seals the tube. These flanges 23 also extend
circumferentially slightly outwardly beyond the margins of tube 21
to provide a guide or bearing portion for the tube 21 and stopper
20, as these portions of the sample collection tube assembly are
posi-tioned within the holder 11.
As is well known in the art, the end 17 of cannula 16 of holder 11
is first inserted in the appropriate portion of the patient's body.
Then the holder can be used for collection of one or more fluid
samples in individual sample tube assemblies 19, without the
necessity of removal and reinsertion of the cannula with respect to
the patient. An individual sample tube assembly 19 is pushed into
the open end 12 of holder 11, until the closure member 20 is
penetrated by the lower end 18 of the cannula or needle. This
permits delivery of a fluid sample through the cannula to the
interior of tube 21. To facilitate the insertion and removal of
tube 21 and its cap 20 with respect to holder 11, the cap 20 has a
central axial recess 24 at its upper end thereby providing a
portion 26 of reduced thickness along the longitudinal axis of the
stopper 20 and tube 21 at the area to be penetrated by the lower
end 18 of needle 16. Stopper 20 is made of resilient material which
is adapted to provide a self-sealing action and close the opening
made by needle portion 18, as the tube 21 and closure member 20 are
withdrawn from holder 11. Thus, the biological fluid sample will be
retained in the individual sample tube assembly 19 in a sealed
condition for further processing and/or testing.
The construction as described up to this point may be essentially
similar to the known sample collecting devices presently available
in the medical arts. Such sample tube assemblies 19, for example,
are customarily vacuumized, so that the relatively lower pressure
within tube 21 will assist in drawing body fluid through needle 16
from the patient, and will permit the complete filling of tube 21
without having to provide for escape of air as the tube is
filled.
According to the present invention, the improved sample tube
assembly of FIG. 1 is further provided with a movable member 28
which is designed to serve in this embodiment as a scraper member
for removal of clotted blood from the upper portion of tube 21 to
the lower portion of the tube during subsequent centrifuging of the
sample. Member 28, as shown in FIG. 2, includes an annular scraping
ring portion 29 having an external diameter designed to fit closely
within the inner surface of tube 19, but not so tightly as to
prevent all axial movement of the member 28 along the inside wall
of the tube. Member 28 may be initially formed from a cylindrical
tube of plastic material, cut into sections as shown in FIG. 2.
Each section includes a series of angular segments 31 projecting
axially from the annular scraping portion 29 of member 28. The
segments or flaps 31 are defined by intermediate cuts 32 which
remove a portion of the material between the flaps 31.
The exact shape and dimensions of flaps 31 may be varied to
accomodate the particular shape of the closure member with which
they are designed for use. As shown in FIG. 1, the cuts have such
shape and dimensions as to let them flex inwardly and provide a
substantially continuous cap portion at 33 covering the underside
34 of stopper 20 when member 28 is positioned immediately below and
adjacent to the stopper 21. Thus, if stopper surface 34 is
spherical, the segments 33 will be cut as segments of a sphere so
that they will fold together and form a spherical inner cover at 33
for the stopper surface 34, when the parts are assembled in the
position of FIG. 1. In this position the inner stopper surface 34
and the upper inner wall portions of tube 21 are covered and
protected by member 28. Thus any of the fluid which clots or dries
within that portion of the tube will be deposited on the inner
surface of member 28, rather than on the portion of the stopper or
tube walls covered and protected by member 28.
The tube 21 and stopper 20 are removed as a unitary assembly from
holder 11 for further processing. It is then possible to apply
force externally of the tube and cause movement of member 28
downwardly along the longitudinal axis of tube 21. The necessary
forces can be applied either manually or mechanically, without
removing the stopper 20 and exposing the operator to the risk of
infection from the contents of the tube or allowing evaporation of
the contents to occur or exposure of such contents to room air. As
shown in FIG. 3, the forces are preferably applied by centrifuging
the sample tube assembly and its contents in known manner. As
member 28 is urged downwardly by centrifugal force in the
centrifuge, it starts its movement down through the tube 21, the
segments 31, when moved away from the stopper surface 34, will tend
to flex upwardly to their original positions as shown in FIG. 2.
Thus the member 28 will effectively provide a fluid passage means
through the central space which was originally covered by segments
31. This will permit member 28 to move down through the fluid as
shown in FIG. 4, without substantial resistance by the fluid. The
fluid is thus shifted relatively to the scraper member 28 from the
lower side to the upper side of that member as member 28 moves down
through the fluid in tube 21.
As shown schematically in FIG. 3, a plurality of sample tube
assemblies 19, with the stoppers 20 still in place on tubes 21, can
be positioned in a centrifuge of known construction which is then
rotated at high speed to apply centrifugal forces tending to drive
the heavier or denser portion of the tube contents from the top
toward the bottom of the tube. In normal blood testing, for
example, such centrifuging will move the red cells of the blood
down to the bottom of the tube and will leave relatively clear
fluid of serum or plasma at the top of the tube. This clear fluid
can later be removed for any desired testing.
The scraper of the present invention responds to the forces
generated during such a centrifuging operation and is forced
downwardly through the tube, just as the red cells are forced
downwardly. During this movement through the tube and through the
fluid within the tube, the member 28 maintains its orientation by
virtue of the axial length of the annular ring portion 29, so that
the member 28 does not become angularly tilted or stuck within the
tube. During downward movements, the lower edge of the annular
portion 28 effectively scrapes along the inner walls of tube 21 to
loosen any clotted materials and insure their movement downwardly
out of the desired clear fluid area at the top of the tube. Any
clotted materials which were initially deposited on the inner
surfaces of either the annular portion 29 or cap segments 31 will
also be pulled downwardly with the scraper member 28 so that the
upper portion of the tube including both the tube walls and the
inner surfaces of stopper 20 will be clear of such solid particles.
The clear fluid at the top of the tube can subsequently be removed
in known manner for further laboratory processing, including any
desired tests of the clear serum, without its contamination by
solid particles which might otherwise have been deposited and
remain in the upper portions of the tube.
As further shown in FIG. 3, a simple centrifuge includes a rotary
carrier portion 36 having a rack or other holding means 37 in which
the individual tube assemblies 19 can be supported, with their
closure members 20 still in sealing position. A suitable motor 38
causes high speed rotation of the carrier 36 around a central axis
or shaft 39. Since the bottom portions of tubes 21 are supported at
a greater distance from the axis of rotation 39 than the upper
portions of tube 21, the centrifugal force applied to the contents
of each tube 21 will tend to urge the denser or heavier particles
toward the bottom of the tube, while the lighter material such as
the clear fluid needed for further testing remains at the top
portion of each tube.
FIG. 5 shows a modified form of scraping member according to the
invention. In this form, the member 41 is formed of plastic
material or chemically inert substance with a base scraper portion
42 of annular ring-like configuration and with a hemispherical
upper cap portion 43 integrally connected to the annular scraping
portion 42. To provide passage means for relative movement for
fluids from the lower side of member 41 to the upper side, when
this member is forced downwardly within a sample tube 21, the
member is provided with a series of valves or flap members 44
defined on three sides by appropriate cuts 46 in the cap material.
The flap portions are held in their cap closing or hemispherical
positions as shown in heavy lines in FIG. 5, when the cap member 41
is positioned immediately below and adjacent a stopper or closure
member such as 20 in FIG. 1. When the application of external
force, for example by a centrifuge, starts the downward movement of
scraper member 41 through the tube 21, the valve or flap members 44
can flex outwardly as shown in dotted lines at 47 in FIG. 5. Thus
each flap will provide an opening in the cap member 41 to permit
the cap to move down through the fluid, so that the fluid which was
originally below the cap will not resist the downward movement of
the cap, but will effectively flow through the flap opening to a
relative position above the downwardly displaced cap.
In FIG. 6, another modified form of scraper member is shown at 49.
In this case the scraper is of composite construction and includes
an annular solid ring 51 which may be of metal or other solid
material. Ring portion 51 has a sharp lower scraping edge 52 and
the solid ring is designed to slide readily down through a sample
tube 21 without tilting or jamming. Member 49 also includes a
hemispherical cap portion 53 which has its lower edge bonded or
adhesively connected at 54 to a flexible annular member 55. Member
55 in turn is adhesively bonded or otherwise connected to the
inside of annular ring 51. Thus the members 51, 53 and 55 form a
composite scraper member with an annular ring portion 51 and a cap
portion 53. Within the cap area 53 one or more openings 56 are
provided to serve as valve openings for the purpose already
discussed. Intermediate member 55 includes upwardly projecting
flexible portions 57 and 58 which overlie the respective openings
56 and effectively close them to provide a continuous cap area,
when the member 49 is positioned in a tube 21 immediately below and
adjacent to the stopper or closure member 20. Here again, when the
application of external force urges member 49 downwardly in tube
21, the cover flaps 57, 58 may flex upwardly as shown in dotted
outline in 59 to uncover the openings 56. These openings 56 then
provide a passage way for relative movement of the fluid from a
position below the member 49 to a relative position above that
member, as member 49 moves downwardly through the fluid.
Another form of scraper member according to the invention is shown
in FIGS. 7 and 8. This scraper member 61 includes a relatively
solid annular scraping portion 62 designed to fit within and slide
longitudinally of a sample tube 21. Across one end of the annular
ring 62, a relatively thin rupturable membrane 63 is secured. Thus,
as shown in FIG. 7, membrane 63 fully covers the end of annular
scraping ring portion 62 and provides a composite member 61 which
may be positioned immediately below the stopper of a sample tube
21, in the same general manner illustrated in FIG. 1. When the
stopper 20 of such a sample tube is penetrated by the lower end 18
of a needle in a holder 11, the needle will also penetrate membrane
63. In this case the lower surface of stopper 20 could be formed as
a flat surface corresponding to the surface of membrane 63, so that
the membrane would be held flat against the stopper during the
preliminary insertion of the sample tube in the holder. Preferably
the nature and thickness of membrane 63 is selected so that
penetration of the holder needle end 18 will not completely rupture
the membrane 63 but will merely perforate it at its center. Upon
subsequent application of external force by a centrifuge or
otherwise, however, the scraper member 61 will be urged downwardly
through the liquid in the sample tube, and the membrane 63 may be
further ruptured or torn as shown at 64 in FIG. 8 as needed to
permit movement of the member 61 downwardly through the fluid. As
indicated, the selection of material and dimensions for membrane 63
is preferably such that the membrane will not be ruptured by mere
penetration of needle end 18 initially, but can readily be torn to
the degree necessary to permit relatively free downward movement of
member 61 during centrifuging.
Still another embodiment according to the invention is shown in
FIG. 9. Here the scraping member is initially formed as an integral
part of the cap or stopper member 65. Member 65 has an upper
portion essentially similar to stopper 20 of FIG. 1 and is designed
to fit tightly within the end of a sample tube 21. An enlarged
upper end 66 provides a suitable flange to limit the inward
positioning of the stopper within the tube. The central upper
portion of the stopper is cut away at 67 to provide a relatively
thin section 68 at the center of the stopper for penetration by the
needle end 18 of the holder 11. A scraper member 69 is integrally
connected to the upper stopper portion 65 by one or two connecting
portions 71 and 72 of relatively small cross section. The total
cross section of these connecting sections 71 and 72 is just
sufficient to hold the scraper portion 69 in assembled position
with cap 65, but is dimensioned to provide a readily frangible
connection between these two parts. Scraper member 69 includes an
annular scraping ring section 73 of relatively rigid and heavy
material, which is inter-connected with portion 69 by a suitable
annular projection 74 on ring 73 which interfits with a suitable
groove 75 in member 69. The lower surface of member 69 within ring
73 may be of hemispherical shape as shown at 76. An opening 77 is
provided at the center of scraper portion 69 so that initial
insertion of the holder needle end 18,when the sample tube is
positioned within holder 11,will permit free movement of needle end
18 through the scraper member 69, without prematurely pushing the
scraper away from the rest of stopper 65 by breaking the
connections at 71 and 72. By making scraper ring 73 of reasonably
heavy material, the force available to rupture the connection 71
and 72 during centrifuging will be effectively increased.
Although FIG. 9 shows portions 71 and 72 as being made of the same
material as the stopper 65 and the scraper member cap portion 69,
this exemplification of the invention may be further modified by
first forming the stopper and scraper members as entirely separate
members and then interconnecting them at points such as 71 and 72
by a spot of readily releasable adhesive. Thus the scraper (or some
other desired processing or treatment member) may be initially
secured in some way to the closure cap of a sample tube assembly
and may be forceably separated from the cap at a desired time by
application of suitable force externally of the tube assembly.
The fluid sampling apparatus described in this specification thus
provides a novel means for desired processing or treatment of a
biological or other fluid in a sample container by application of
external forces to the container to cause movement of a suitable
processing member within the container, without the necessity of
opening the container. The processing members shown herein have
releasable means normally holding the processing member at a first
position in the container during normal handling of the container.
The releasable means is constructed and arranged to permit movement
of the processing member away from its first position in response
to the application of substantial forces to the assembly externally
of the container. In some cases the releasable means is provided by
frictionally interengaging portions on the processing member and
container. In other cases the releasable means may be provided by a
releasable connection between the processing member and the inner
side of a closure member for the container. The invention is
particularly useful for the scraping or clearing of clotted
materials from one end of a blood sample container, but may also be
useful in other applications.
It will be apparent to those skilled in the art that the shape,
dimensions and other details of construction of the fluid sample
tube assemblies shown in the drawings could be further modified in
various ways within the principles of the present invention. The
present specification, however, sets forth some of the ways in
which the invention may be put into practice, including the best
mode presently contemplated for carrying out the invention.
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