U.S. patent number 3,561,672 [Application Number 04/713,595] was granted by the patent office on 1971-02-09 for washing process and centrifuge assembly.
This patent grant is currently assigned to Baxter Laboratories, Inc.. Invention is credited to Charles R. Memhardt, Charles A. Schlutz, Stanley J. Sedivy.
United States Patent |
3,561,672 |
Schlutz , et al. |
February 9, 1971 |
WASHING PROCESS AND CENTRIFUGE ASSEMBLY
Abstract
A fluid system for separating materials in each of a plurality
of batches which are simultaneously washed by forcing a fluid
through a centrifuge, provides independent pressure heads for each
batch to enable flow of equal volumes through said batches,
respectively.
Inventors: |
Schlutz; Charles A. (Glenview,
IL), Sedivy; Stanley J. (Chicago Ridge, IL), Memhardt;
Charles R. (Morton Grove, IL) |
Assignee: |
Baxter Laboratories, Inc.
(Morton Grove, IL)
|
Family
ID: |
27256704 |
Appl.
No.: |
04/713,595 |
Filed: |
March 18, 1968 |
Current U.S.
Class: |
494/1; 494/10;
494/17; 494/20; 494/27; 494/37 |
Current CPC
Class: |
B04B
5/00 (20130101); B04B 5/0428 (20130101); B04B
9/12 (20130101); B04B 1/14 (20130101); B04B
13/00 (20130101); B04B 11/00 (20130101); B04B
1/00 (20130101); A61M 1/3693 (20130101); A61M
1/3696 (20140204); B04B 11/04 (20130101); B04B
5/0442 (20130101); B04B 11/06 (20130101); A61M
1/3692 (20140204); A61M 5/14 (20130101) |
Current International
Class: |
B04B
5/00 (20060101); B04B 13/00 (20060101); B04B
11/00 (20060101); B04B 11/04 (20060101); B04B
11/06 (20060101); B04B 1/00 (20060101); B04B
5/04 (20060101); B04B 9/00 (20060101); B04B
9/12 (20060101); A61M 5/14 (20060101); A61M
1/36 (20060101); B04B 1/14 (20060101); B04b
005/02 () |
Field of
Search: |
;233/17,26,19,28,18,21,34,38,45,46 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Jenkins; Robert W.
Claims
We claim:
1. In a washing centrifuge assembly having a centrifuge rotor and a
pair of containers supported from said centrifuge rotor for
rotation therewith, a combination comprising: charging means for
moving influent in predetermined volumes into each of said
containers under an independent pressure head as said rotor spins
for washing therein contained material, including means defining an
independent influent path for the influent for each of said
containers; and discharging means for collecting effluent from each
of said containers in a volume corresponding to influent moved into
said containers.
2. A combination according to claim 1 in which the charging means
comprises a pump for substantially simultaneously effecting flow of
independent substantially equal influent volumes into said
containers, respectively, and means defining an influent pathway
between said pump and each of said containers.
3. A combination according to claim 1 in which the means defining
an independent influent path includes distributor means including a
part arranged for corotation with said rotor and having influent
outlet means, said distributor means having influent inlet means,
and means for isolating between said inlet means and said outlet
means all influent for one container from all influent for the
other.
4. A combination according to claim 1 characterized by distributor
means arranged in fluid association with said charging means for
delivering influent to said containers and having first and second
parts arranged for relative rotation, one of said parts arranged
for corotation with said rotor; influent inlet and outlet means
associated with said first and second parts, and chamber defining
means arranged in said distributor means for isolating between said
inlet and outlet openings all influent for each chamber from all
influent for the other chamber.
5. A combination according to claim 1 further characterized by a
distributor-collector mounted for fluid communication with said
charging means and said discharging means, said
distributor-collector having first and second parts arranged for
relative rotation; influent outlet and effluent inlet means
associated with said second part; and means arranged between said
first and second parts defining a plurality of chambers for
isolating all influent for each container from all the influent for
the other container and for isolating all effluent from all
influent.
6. A combination according to claim 5 in which the chambers for
isolating the influent are of lowermost disposition in said
distributor-collector for minimizing contamination of influent with
effluent.
7. A combination according to claim 1 further characterized by an
influent reservoir disposed above said containers for delivering
influent to said charging means; an influent conduit arranged in
fluid communication with said charging means and defining a first
influent path to each of said containers, and a tube arranged in
fluid communication with said reservoir and defining a second
influent path bypassing said charging means for gravity feed to
each of said containers through an associated of said influent
conduits.
8. A combination according to claim 7 characterized by an
electrically energized flow control mechanism associated with said
paths for establishing fluid communication between said containers
and selected said charging means and reservoir.
9. A combination according to claim 8 in which the flow control
mechanism includes means for simultaneously clamping said conduits
upstream of their connection to said tubes and opening said tubes,
and simultaneously
clamping said tubes and opening said conduits. 11. A combination
according to claim 8 further characterized by effluent duct means
arranged in fluid communication with said discharging means for
removal of effluent form said containers, said flow control
mechanism arranged for stopping and permitting flow in said
effluent duct means simultaneously with the interruption and
permitting of flow in said influent conduits upstream of
the connection thereof to said tubes. 11. A combination according
to claim 10 in which said flow control mechanism comprises a
plurality of pressure members spaced from said containers for
simultaneously closing said conduits and duct means supported for
gravity filling said containers,
conduits and duct means between said pressure members. 12. In a
washing centrifuge assembly having a rotor, container means
supported from said rotor for rotation therewith, charging means
for moving influent into said container means as said rotor spins,
discharging means for receiving effluent from said container means
during movement of and in substantially the same volume as influent
moved, a combination comprising passaged means arranged in fluid
association with said charging means and discharging means for
introducing influent into and removing effluent from said container
means, and means responsive to centrifugal force and having a first
condition in which said passaged means is shut for blocking flow
into and out of said container means and a second condition in
which said
passaged means is open for flow into and out of said container
means. 13. A combination according to claim 12 in which the means
responsive to centrifugal force comprises a clamping member
normally biased for effecting said first condition and for moving
to effect said second condition upon generation in said assembly of
centrifugal force of
predetermined magnitude. 14. A combination according to claim 13 in
which said clamping member is corotational with said rotor and
characterized by spring means for biasing said clamping member for
effecting said first condition and proportioned to yield upon
generation in said assembly of a
centrifugal force of said predetermined magnitude. 15. In a washing
centrifuge assembly having a first rotor, container means
corotationally supported from said first rotor, charging means for
moving influent into said container means as said first rotor
spins, discharging means for receiving effluent from said container
means during movement of and in substantially the same volume as
influent moved, a combination comprising: a body corotationally
secured to said first rotor for securing said charging and
discharging means to said first rotor, and a disposable
distributor-collector removably mounted in said body and arranged
medially of said charging and discharging means for transferring
influent to and effluent from said container means while said first
rotor is spinning.
A combination according to claim 15 in which said
distributor-collector has a stator and a second rotor mounted for
rotation about said stator and arranged in keyed association with
said body, some of said charging and discharging means extending
into and out of said second rotor for delivery of influent and
removal of effluent from said containers, other of said charging
and discharging means extending into and out of said stator for
delivery of influent to and removal of effluent
from said distributor-collector. 17. A combination according to
claim 16 in which said body has an opening, said second rotor
disposed outwardly from said stator and having a depending keying
extension removably engaged
in said opening for rotating said second rotor with said first
rotor. 18. A combination according to claim 17 in which said
distributor-collector is vertically disposed with said stator
having an extension projecting upwardly from said second rotor and
characterized by a bearing mounted in nonrotating, stationary
relation relative said first and second rotors and having means for
engaging said extension for holding said stator fixed relative to
said first and second rotors while said
first and second rotors spin. 19. A combination according to claim
15 in which said body comprises a centrifugal clamp for enabling
flow through said passaged means only upon generation of
centrifugal force of a
predetermined level. 20. In a process for material separation by
centrifugation during which a first material is removed from a
second material by a wash fluid which is first passed through the
second material and therefrom removed with first material as spent
fluid, the improvement comprising passing predetermined volumes of
the wash fluid each under an independent pressure head through
separate flow paths into each of a plurality of batches of said
second material while spun about a common
axis. 21. A process according to claim 20 in which the wash fluid
is forced in substantially equal volumes through said batches,
respectively.
2. A process according to claim 20 in which the wash fluid is
forced through said batches substantially simultaneously.
Description
The present invention relates to centrifugation. More particularly
the invention relates to centrifugal apparatus for use in washing.
Specifically the invention relates to an assembly, including a
centrifuge, for washing particles such as red blood cells.
Heretofore it has been known to wash particles by using
centrifuging means. The principles generally relating to such
particle washing have been effectively applied in washing red blood
cells, particularly for reconstitution following treatment with
such reagents as glycerol, polyvinyl pyrrolidone and the like for
cell protection. Two heretofore known systems for reconstituting
preserved red blood cells by the aforestated technique have gained
significant practical success. One thereof embodies the teachings
of U.S. Pat. 2,906,453. The other thereof embodies the teachings of
U.S. Pat. 3,347,454 and is assigned to the assignor of the present
application.
While the apparatus of both prior systems are practical for washing
preserved red blood cells in single batches, neither they, nor any
of heretofore known means, is adequate effectively and efficiently
for washing a plurality of batches of preserved red blood cells
simultaneously. That is to say, while simultaneous multibatch
washing could be practiced in accordance with heretofore known
teachings, thereto attendant inefficiencies would increase costs
inordinately. In consequence, prior to the present invention,
washing of red cells in more than one batch at a time in a given
centrifuge assembly has been neither practical nor conventionally
practiced, except experimentally. The inefficiencies result from
differential resistance to flow of wash fluid generated in material
comprising the batches simultaneously being processed. The
phenomenon is such that wash fluid in ever increasing volume flows
through one of the batches while it increasingly bypasses any
other.
It is an object of the present invention to provide an improved
process and assembly for centrifugal washing.
It is another object of the invention to provide improved process
and apparatus for centrifugally washing particles, particularly,
red blood cells.
It is a further object of the invention quickly and efficiently to
reconstitute red blood cells which have been treated with
cryoprotective agents.
It is an additional object of the invention to enable washing of a
plurality of batches of particles, particularly red blood cells,
simultaneously.
Moreover, it is an object of the invention to prevent inefficient
material separation resulting from differential resistance to flow
in a plurality of batches during simultaneous washing thereof in a
centrifuge.
The foregoing objects are effected, in a washing centrifuge
assembly having a rotor and a pair of containers supported from
said rotor for rotation therewith, by charging means for moving
influent into each of said containers under an independent pressure
head as said rotor spins, and discharging means for collecting
effluent from each of said containers in a volume corresponding to
influent moved into said containers. In another sense the objects
are effected by a process in which material to be washed is
separated into a plurality of batches which are simultaneously
centrifugally spun. While they are spinning influent under the
force of an independent pressure head is flowed through each of the
batches; and effluent from said batches is collected in volumes
corresponding to the volumes of influent flowed through said
batches.
The foregoing and other objects, features and advantages of the
invention will become more apparent upon consideration of the
following description and appended claims, when considered in
conjunction with the accompanying drawings wherein the same
reference character or numeral refers to like or corresponding
parts throughout the several views.
On the drawings:
FIG. 1 is a fragment of a vertical sectional view through a
centrifuge assembly embodying the present invention, some parts
being shown in elevation and other parts broken away, a pair of
containers being shown at an angle 90.degree. from actual aspect
and in a nonspinning condition.
FIG. 2 is a flow scheme of said assembly, the containers being
shown in a spinning condition.
FIG. 3 is a top plan view of a distributor-collector comprising
said assembly.
FIG. 4 is a vertical sectional view according to the line 4-4 of
FIG. 3.
FIG. 5 is a vertical sectional view according to the line 5-5 of
FIG. 3.
FIG. 6 is a horizontal sectional view according to the line 6-6 of
FIG. 4.
FIG. 7 is a top plan view of an assembly control box, its cover
having been omitted.
FIG. 8 is a view according to the line 8-8 of FIG. 7 but with the
cover shown.
FIG. 9 is a side elevation view of fluid control means comprising
said assembly, a pair of clamping members being shown abnormally in
opposite conditions.
FIG. 10 is a view according to the broken section line 10-10 of
FIG. 9.
FIG. 11 is a view according to the line 11-11 of FIG. 1, a medial
part being broken away.
FIG. 12 is a scheme of wiring for said assembly.
Referring now more particularly to FIG. 1, there is shown a washing
centrifuge assembly 15 comprised of a housing or outer shell 17
only an upper portion of which is shown. Within chamber 19 of shell
17 a centrifuge rotor 21 is concentrically disposed for rotation.
Rotor 21 has a hub 25 which is mounted corotationally with a driven
spindle 27, the latter member being suitably connected to prime
mover means (not shown). A plurality of radial members 26 (only two
of which are shown) project outwardly from hub 25. A plurality of
arms 29, arranged in parallel pairs, project eccentrically from
adjoining of members 26. A pin 33 which is circular in cross
section extends through each of arms 29 for projection from
opposite arm faces 31. Adjoining projections of pairs of pins 33
are engaged by opposed pairs of arcuate shoulders 35 of a plurality
(herein shown as a pair) of receptacles 23 and 24 for swinging
support of said receptacles radially from rotor 21. Apart from
evident structural variation, said receptacles may be constructed
according to copending application Ser. No. 672,125, assigned to
the assignee of the present application.
Container means comprising a plurality of containers 37 and 38,
which may be fashioned according to said copending application, are
disposed in receptacles 23 and 24, respectively, in a manner such
that each container is supported from said rotor for rotation
therewith. Material to be processed, herein shown as particles 36
such as preserved red blood cells, is divided into a plurality of
batches which may be of equal size, and held in containers 37 and
38 for spinning for centrifugation simultaneously with rotation of
rotor 21. The invention, however, is not limited to washing
simultaneously only one pair of batches. More can be washed
simultaneously. Nor is the invention limited to washing particles,
inasmuch as washing of materials in other physical forms is also
comprehended.
In the illustrated embodiment, an inverted cone-shaped base
provides a seat 39 in each of the receptacles 23 and 24 for an
associated of containers 37 and 38. A cap 41 for each of
receptacles 23 and 24 has a pair of bores through which an influent
duct 43 and an effluent duct 45 extend for fluid circulation
through each of said containers. The parts are proportioned so that
a flange 47 on each of said caps will snugly seat against a rim 49
of a corresponding receptacle as a result of centrifugal force when
the parts assume the relationship shown in FIG. 2. However, when
receptacles 23 and 24 are in the condition of FIG. 1 the normal
pressure under which each container is filled with its material to
be washed may hold each flange 47 spaced from associated rim
49.
Fluid control mean responsive to centrifugal force comprises a
centrifugal clamp assembly generally designated 51 (FIGS. 1, 9 and
10) which is secured by fasteners such as screws 53 to the top of
hub 25 for corotation with rotor 21. Said fluid control means has a
first condition in which ducts 43 and 45 are shut to block flow
into and out of containers 37 and 38 and a second condition in
which said ducts are open for flow into and out of said containers.
To that end, clamp assembly 51 comprises a body 55 having a
plurality of wells 56 and 57 which are herein shown of like profile
and disposed to correspond with the disposition of containers 37
and 38, herein shown as being in diametric opposition. Clamping
means comprising a clamping mechanism 58 associated with each of
containers 37 and 38 is disposed in each of wells 56 and 57,
respectively. A block 59 comprises each clamp mechanism 58 and is
proportioned to slide centrally and outwardly within the limits of
its associated well along a floor 60 defining such well. A cover 93
(FIG. 9) suitably removably held on body 55 closes wells 56 and 57
from above to trap in each thereof an associated block 59.
Each block 59 has a plurality (herein shown as two) of outwardly
opening, horizontally spaced apart bores 61 and 62 which
accommodate spring means comprising a pair of compression springs
63 and 64, respectively. The outer ends of each pair of the latter
members bear against the inner surface 65 of an associated of outer
sidewalls 68 and 70 respectively defining wells 56 and 57 for
biasing each block inwardly or centrally. Each block 59 carries a
generally T-shaped clamp member 67 which is secured thereto by a
suitable fastener such as a screw 69. The stem 71 of each clamp
member comprises a radial arm which is slideably arranged for
radial extension in a slot 73 in body 55, said slots fashioned so
that wells 56 and 57 open through sidewalls 68 and 70. Each clamp
member 67 also comprises a pair of clamping extensions 75 and 76
integral with, and projecting horizontally in opposite directions
from, an associated stem 7. Under normal tensioning of each pair of
springs 63 and 64 its clamping extensions are urged toward an
adjoining of sidewalls 68 and 70, as illustrated to the right of
FIGS. 9 and 10. Said springs, however, are tensioned so that under
centrifugal force generated when receptacles 23 and 24 have assumed
the extreme position of FIG. 2, its block 59 will be thrown
outwardly to the outer limits of its recess 57 thereby causing
projection of corresponding clamping extensions 75 and 76 from the
body 55, as illustrated to the left of FIGS. 9 and 10. It is
appreciated that all of the clamping mechanisms 58 simultaneously
will assume the condition shown either to the right or to the left
of FIGS. 9 and 10; and that the showing of both conditions in each
view is solely for the purpose of illustrating alternate extremes,
which normally will not be present simultaneously.
Each pair of extensions 75 and 76 is fashioned to generate a pair
of recesses or pockets 77 and 78 through which influent and
effluent ducts 43 and 45 of an associated of containers 37 and 38
project. Each pair of said recesses is proportioned so that when an
associated clamp member 67 is in its first condition, as shown to
the right of FIGS. 9 and 10, flow in corresponding ducts 43 and 45
will be clamped shut. Whereas, when such clamp member is in its
second condition, illustrated to the left of FIGS. 9 and 10, said
last mentioned ducts will be unclamped to permit unimpaired flow
therethrough.
To facilitate clamping, each of sides 68 and 70 has a pair of
horizontal elevations 81 and 83 which project in opposite
directions from an associated slot 73. At its outer end each of
extensions 75 and 76 has a pair of enlarged ears 85 and 87 which
are associated in a U-shape and proportioned for engagement about
associated of elevations 81 and 83 in a manner illustrated to the
right of FIG. 9 for clamping corresponding ducts 43 and 45.
Distributor means or a fluid handling mechanism comprising a
distributor-collector 89 controls flow of fresh influent or wash
fluid to and spent effluent or waste from the material contained in
containers 37 and 38. In terms of the influent,
distributor-collector 89 is disposed upstream of clamp assembly 51
from which it projects upwardly. The distributor-collector
comprises relatively rotatable first and second parts, being a
cup-shaped rotor 97 and a therein concentrically associated
cylindrical stator 105 (FIG. 4).
A male component 95 (FIGS. 1, 4 and 5) carried from the lower wall
99 of rotor 97 is removably keyed or snugly engaged in an opening
or hole 91 (FIG. 10) formed in body 55 for transmission of torque
of rotor 21 to rotor 97 for corotation of said rotors. Rotor 97 has
an upwardly extending cylindrical sidewall 107 which defines an
upper opening 108. The latter is closed by a cap 101 having an
aperture 109 and secured to the top of sidewall 107 by fasteners
such as screws 103, only one of which is numbered in FIG. 3.
The outside diameter of stator 105 is less than the inside diameter
of rotor 97 by reason of which a space 113 is formed about said
stator, said space being closed at the top and bottom by cap 101
and wall 99, respectively. Said stator has a lower end portion 106
which is journaled in wall 99, and a medial portion which is
journaled in the aperture of cap 101 and an enlarged head 111 which
projects upwardly from the rotor and is arranged in bearing
association with the top of cap 101.
Chamber defining means comprise a plurality of annular flexible
sealing members 115, 117, 119 and 121 which are arranged in
vertically spaced horizontal planes with the upper sealing member
121 disposed against cap 101 for dividing space 113 into a
plurality of vertically spaced chambers 123, 125, 127 and 129. The
circumferences of the sealing members snugly engage the inner
surface of rotor wall 107 while the inner surfaces of said sealing
member snugly engage the outer surface of stator 105. Thereby each
of chambers 123, 125, 127 and 129 is sealed from the others thereof
and is defined by an inner wall comprising a section of stator 105
and an outer wall comprising a section of rotor 97. A pair of
apertures in the chamber walls comprise inlet and outlet means for
said chambers and accordingly distributor-collector 89.
In the present embodiment each of the receptacles 23 and 24 is
associated with a pair of said last mentioned chambers in a manner
such that one of each pair is an influent chamber and the other
thereof is an effluent chamber. In the present and preferred
embodiment of the invention the lowermost chambers 123 and 125 are
influent chambers of which chamber 123 is associated with
receptacle 24, whereas chamber 125 is associated with receptacle
23. To that end, the upstream end portion 129 of duct 43 from
receptacle 24 projects through one outlet opening in wall 107 in a
fluid tight seal for fluid communication with chamber 123. On the
other hand, the upstream end portion 131 of duct 43 from container
23 extends through the other outlet opening in wall 107 in a fluid
tight seal for fluid communication with chamber 125. In the present
and preferred embodiment, chambers 127 and 129 are effluent
chambers which are disposed above influent chambers 123 and 125 and
are in fluid communication, respectively, with receptacles 23 and
24. For that purpose the upper end portion 133 of duct 45
associated with receptacle 24 projects through one inlet opening in
wall 107 in a fluid tight seal for fluid communication with chamber
127. The upper end portion 135 of duct 45 associated with
receptacle 23 projects through the other inlet opening in wall 107
in a fluid tight seal for fluid communication with chamber 129.
By placing influent chambers 123 and 125 below the effluent
chambers, the likelihood of contamination of influent by effluent
because of faulty seals in distributor-collector 89 is minimized.
Moreover, the pressures generated within the system are such that
downstream of containers 37 and 38 the effluent paths may be
combined, if desired, with impunity.
Stator 105 has a plurality of vertical bores 137, 139, 141 and 143
(FIGS. 4, 5 and 6) which open through the top of stator head 111.
The lower ends of bores 137, 139, 141 and 143, respectively,
communicate with chambers 123, 125, 127 and 129. By reason of the
foregoing, bores 137 and 139 are influent bores whereas bores 141
and 143 are effluent bores.
Charging means for moving influent or wash fluid into containers 37
and 38 and through the batches therein contained comprises a pump
153 (FIG. 2) which is arranged in fluid communication with influent
bores 137 and 139 through a pair of flexible conduits 145 and 147.
Said conduits together with distributor-collector 89 and ducts 43,
43 comprise means defining an independent path or influent pathway
for each of containers 37 and 38 and extending between said
containers and the pump. Pump 153 may be of the roller type for
impelling substantially equal volumes of influent under independent
pressure heads into conduits 145 and 147 and accordingly containers
37 and 38. In the present embodiment, movement of influent through
each system is simultaneous; however other than simultaneous
influent movement may be desirable under washing conditions other
than that specifically described herein.
Fluid from a reservoir 233 supplies influent for pump 153 by
gravity. The reservoir is also in direct fluid communication with
conduits 145 and 147 through a pair of tubes 235 and 237, which
bypass the pump for gravity feed into containers 37 and 38,
respectively, for a reason to become apparent from ensuing
description.
Discharging means for collecting effluent or spent wash fluid
comprises an effluent tank 155, which is in fluid communication
with bores 141 and 143 through duct means herein comprised of ducts
149 and 151, respectively.
A bearing mechanism generally designated 157 (FIGS. 1 and 11) for
the relatively stationary part of a rotational assembly comprises a
retainer 159 having a pair of spaced apart fingers 161 and 162
which define an elongated recess 163 in which an upper reduced
portion 165 of stator head 111 is intimately engaged for sliding
normally of an expansion band or bar 167 when the latter is in
assembled condition. The retainer is captured in a pocket 166
formed in medial section 168 of expansion bar 167 to permit sliding
of the retainer longitudinally of said bar in opposite directions
in response to corresponding stresses during rotation of rotor
97.
Bar 167 comprises a pair of opposed end sections 158 and 160 at
least one of which is telescopically connected to medial section
168. Said end sections carry a pair of opposed fittings or adapters
169 and 177 having outwardly extending hooks 171 and 181,
respectively for projection into a mating aperture formed in the
lower end of a skirt 173 (FIG. 1) hung in the top opening of the
centrifuge from shell 17. An annular cushion or pad 175 is shown
disposed between the said shell and skirt 173 for cushioning
evident forces brought to bear. In consequence of the foregoing
construction, distributor-collector 89 will be held erect during
rotation of rotor 21, fingers 161 and 162 being proportioned to
prevent removal thereof. However, bar 167 may be contracted to
disengage hooks 171 and 181 from skirt 173 for removing said
distributor-collector from the centrifuge. Thereafter, release of
the rotor 97 from bar 167 by removing the stator head from recess
163 can be achieved.
In the illustrated embodiment section 158 comprises a vertical
plate 185 with which hook 171 is integral and a vertical plate 189.
The inner end portions of said plates are arranged in sliding
association with the outside of opposed parallel faces of medial
section 168. The outer end portions of said plates are separated by
a spacer 187 the width of which is equal to the width of section
168 from the proximate end of which said spacer is spaced. To one
face of said spacer, plate 185 is secured by fasteners such as
rivets 179 and to the opposite face of said spacer, plate 189 is
secured by fasteners such as rivets 191. One end portion of medial
section 168 has a well 193 in which one end of a compression spring
195 is mounted for extending block 187 and accordingly fitting 169
longitudinally of bar 167 and for holding said bar in mounted
position in the centrifuge.
In addition to the condition shown in FIG. 11, bar 167 can assume
two other positions according to the condition of latch means 197
which is mounted transversely of said bar from an end portion 199
of section 168. Said latch means comprises a part in the form of a
rod 201 which extends through a transverse opening or slot 223 in
section 168 and a pair of transversely aligned apertures 203 and
205 in telescopic section 158. While the dimension of opening 223
longitudinally of section 168 is considerably larger than the
diameter of rod 201, the diameter of apertures 203 and 205 is such
that latch means 197 is snugly engaged to limit its movement in
section 158 to transverse sliding. The diameter of aperture 205,
however, is larger than aperture 203 to accommodate sliding of
another part of said latch means, said other part being an annular
bearing extension 206 of a bearing cap 207. The latter is secured
by a screw 209 on one end portion 211 of rod 201 which projects
normally from the outer face of plate 189. A spring retainer 213 in
the form of a cup is secured by a screw 215 to the opposite end
portion 217 of rod 201 said opposite end portion projecting
normally from plate 185. A compression spring 219, which is
disposed about end portion 217, has one end disposed in retainer
213 and the other end bearing against vertical plate 185 for
drawing cap 207 into engagement with the outer surface of plate
189. The parts are proportioned so that under normal biasing
bearing extension 206 will be drawn inwardly of plate 189 into a
reduced part of opening 223.
That is to say, opening 223 has a pair of parallel limiting walls
225 and 227 spaced apart longitudinally of section 168. These walls
define the limits of movement of rod 201 longitudinally of bar 167.
Within the recess 223 there is generated adjacent plate 189 annular
shoulder 229 within the annulus of which bearing extension 206 is
normally biased. The diameter of the annulus formed by the shoulder
229 is less than the space between walls 225 and 227 so that while
the parts are conditioned as in FIG. 11 contraction of bar 167 will
be limited by engagement of the extension 206 and the shoulder 229.
The parts are proportioned so that this extent of contraction is
not enough to permit removal of bar 167 from the centrifuge.
However, it is adequate for accommodating variation in the distance
across (herein shown as a diametric cord) skirt 173 and provided
for bar 167 in assembled condition.
Yet another condition of the bar 167 is required for removing it
from the centrifuge. This is achieved by pushing rod 201 upwardly
with respect to FIG. 11 against the bias of spring 219 until cup
213 engages plate 205. The parts are proportioned so that upon the
last occurrence, extension 206 will be removed from recess 223.
Accordingly, rod 201 will be free for engaging wall 225. In such
last condition bar 167 will have been contracted sufficiently to
permit its removal from the centrifuge.
The foregoing combination enables economical employment of a
disposable collector-distributor 89 for each washing operation
whereby likelihood of introduction of contaminants may be
minimized.
Flow through the system defined by passaged means comprising ducts
43, 45, 149 and 151 and conduits 145 and 147 is controlled through
electrical circuitry (FIG. 12) comprising three solenoids 239, 241
and 243. The latter together with said circuit are arranged within
a control box 245 (FIGS. 7 and 8) having an upper horizontal plate
247 relative to which a cover plate 249 is hingedly arranged for
securance by a latching assembly 255. In the present embodiment,
the latching assembly comprises a post 257 which projects upwardly
from plate 247 through a registering aperture in the cover plate
249 so that adjoining flat surfaces of said plates may be
releasably held in engaged association by a lock 259 associated
with said post.
Plate 247 has a plurality of upwardly opening channels or grooves
261, 263 and 265. Pressure feet or pads 267, 269 and 271 carried on
the ends of reciprocating arms controlled by solenoids 239, 241 and
243 respectively, are arranged for extension through apertures
provided therefor in the bottoms of said channels, respectively.
Medial portions of tubes 235 and 237 are disposed in channel 261.
Downstream portions of ducts 149 and 151 are disposed in channel
263. Portions of conduits 145 and 147, which are upstream of their
communication with tubes 235 and 237, are disposed in channel 265.
The parts are arranged and proportioned so that when the solenoid
is deenergized the flow paths through their associated tubes, ducts
and conduits are open. However, while plate 249 is closed (its
normal operating condition) and a solenoid is energized, its
pressure foot will be projected to clamp therewith associated
ducts, conduits and tubes to cut their flow paths.
For operating the device a plug 273 (FIG. 12) for connecting the
power circuit 275 of the assembly to a 115 volt AC power source
(not shown) is provided. The primary of a transformer 277 is
arranged in series in power circuit 275 which becomes energized
upon closure of a push-to-make, push-to-break, double pole switch
279. In the present embodiment of the invention, the secondary of
transformer 277 is a 24 volt coil with which a selenium rectifier
281 is arranged in parallel for developing a DC effect.
Simultaneously with the energization of transformer 277, a lamp
305, which may be carried from a switch box 307, will light by
reason of connection to one terminal 287 of rectifier 281 through a
conductor 309 and thereby indicate the condition of the power
circuit 275. The other side of said rectifier is connected to a
plane of reference potential, herein shown as ground 282.
One terminal of each of solenoids 239, 241 and 243 is connected
through a conductor 283 to ground. The other terminal 285 of
solenoid 239 is connected to terminal 287 of said rectifier through
a switch 289 of a normally closed relay 291. The other terminal 293
of solenoid 241 is connected to terminal 287 of said rectifier
through a switch 295 of a normally closed relay 297. The other
terminal 299 of solenoid 243 is connected to terminal 287 of said
rectifier through a switch 301 of a normally closed relay 303. By
reason of the foregoing construction, once the plug 273 has been
connected to a power source and the switch 279 closed, solenoids
239, 241 and 243 will become energized whereupon pressure feet or
pads 267, 269 and 271 will be conditioned for cutting flow in the
system.
A grounded coil 309 (upper left of FIG. 12) of a normally closed
relay 311 is energized upon closure of switch 279 by reason of a
conductor 313 which connects one side of said last mentioned coil
and terminal 285 whereupon switch 315 of relay 311 will open. Relay
311 is arranged for lighting a lamp 317 by reason of a circuit wire
319 which will connect said last lamp to the selenium rectifier
through a conductor 318 when switch 315 is in closed condition.
To commence operation of the centrifuge, a normally open switch 321
which is mounted in a housing 324 is manually depressed momentarily
to closed condition. Switch 321 is connected in parallel with the
starting switch of the circuit of a centrifuge motor or prime mover
means for driving spindle 27 in a manner such that once closed,
said circuit will continue to operate the centrifuge regardless of
the condition of switch 321 until stopped by means to be
hereinafter described. Said motor may be of conventional
construction and accordingly it together with its circuit have been
omitted in the drawings.
Relay 291 is included in multiple assemblies 323 which also
comprises a normally open relay 325 and a common coil 327. The
latter member is connected to the circuit (not shown) of the
centrifuge motor. Thereby, upon closure of switch 321, switch 329
of relay 325 and switch 289, which are both magnetically coupled to
the coil 327, respectively, will close and open. When the switch
289 opens, current flow to solenoid 239 as well as to coil 309
become interrupted. Thereupon pressure foot 267 will retract to
open tubes 235 and 237 for establishing fluid communication between
reservoir 233 and containers 37 and 38, provided rotor 21 is
spinning fast enough for clamp assembly 51 to have opened. In
consequence thereof the system will fill with influent and initial
flow through the system will be of gravity. Also, switch 315 will
assume its normally closed condition causing lamp 317 to light,
thereby indicating the open condition of tubes 235 and 237 in
control box 245. Simultaneously, because one terminal 331 of relay
325 is connected to terminal 287 while the other terminal 333 of
said last relay is connected to a grounded lamp 335 mounted in
housing 324 through a circuit conductor 337, lamp 335 will light as
an indicator of the operating condition of the centrifuge.
The precaution of preventing initial filling of the system until a
predetermined centrifugal force is reached tends to prevent
backflow from containers 37 and 38 and possible contamination of
influent. Moreover, accidental emptying of container contents is
also prevented by thus keeping the system closed.
Stopping of gravity flow of influent is effected by normally open
push-to-make, push-to-break, double pole switch 339 which is
mounted in a housing 341. Switch 339 may be operated manually as
shown herein or in response to an electrical effect generated in a
known manner in response to a condition such as a lapse of time or
color or density of effluent accumulating in ducts 149 and 151.
Once closed, switch 339 will be held in closed condition by reason
of magnetic coupling to a coil 345 which is mounted in housing 341.
Said coil is immediately energized on closing of switch 279 through
a relay 347 whose switch 349 is normally biased to closed condition
and which is connected to terminal 287 through a circuit wire 351.
A voltage reducing resistance 343 is interposed in a conductor 353
which connects coil 345 to relay 347.
A circuit wire 355 connects one terminal 357 of switch 339 to a
grounded lamp 360, which when lit indicates operation of pump 153
and pump generated flow through the system. Said terminal 357 is
arranged for connection, through said last switch when closed to
rectifier terminal 287 through a circuit conductor 359. The other
terminal 361 of switch 339 is connected to one side of a grounded
relay coil 363. Coil 363 is disposed in a housing 367 for magnetic
coupling to an assembly of relays comprising heretofore described
relays 297 and 303 and additional relays 369 and 371. Switches 373
and 375 of relays 369 and 371 are normally biased to an open
condition. The arrangement is such that when coil 363 is energized
switches 373 and 375 will be magnetically moved to closed condition
whereas switches 295 and 301 will be opened.
Upon opening of switches 295 and 301 circuits for solenoids 241 and
243 are opened and said last solenoids accordingly become
deenergized. Thereupon pressure feet 269 and 271 move to
nonclamping condition and fluid communication becomes established
between pump 231 and containers 37 and 38 and between said
containers and effluent tank 155. Simultaneously, solenoid 239
becomes energized by reason of closure of relay 369. Accordingly
pressure foot 267 moves to closed condition to interrupt flow in
tubes 235 and 237. The last result is effected because one terminal
377 of relay 369 is connected to terminal 287 of rectifier 281
through a circuit wire 379 and the other terminal 380 of said relay
369 is connected to the plane of reference potential through a
circuit assembly including conductor 381. The latter connects relay
369 to a terminal 383 of a relay 385. In turn terminal 383 is
connected by a circuit wire 387 to a terminal 389 of relay 289.
However, relay 289 is bypassed by a circuit wire 391 which connects
terminal 389 to terminal 285 of solenoid 239 for connection of the
latter through bypass 391 to relay 369. In consequence of the
foregoing, when relay 369 is closed the coil 309 of relay 315 will
also become energized to magnetically impel switch 315 to an open
condition thereby to extinguish lamp 317 simultaneously with the
closure of tubes 235 and 237. When solenoids 241 and 243 are
energized, pump 153 is also actuated by reason of closure of relay
371 which is serially connected between a pair of 115 volt AC
circuit wires 393 and 395 comprising the circuit of said pump.
For operation, the pressure of pump 153 is set at a level
sufficient to overcome the centrifugal force created and to effect
a flow through containers 37 and 38 for washing material 36 and
delivering effluent to tank 155 corresponding to the influent
volume. The rate of flow can be controlled in accordance with
requirements and factors including the character of the material
being washed. None of these factors is critical to the present
invention and accordingly details of the process depending upon the
character or type of material are omitted.
Suffice it to say that washing may be stopped at any desired time
by closing a double pole, push-to-make, push-to-break switch 397
which is mounted in a housing 399. Said last switch may be manually
operated (as illustrated) or automatically in response to an effect
generated by well-known means according to lapse of time or a
physical characteristic of the effluent. Once closed, switch 397
may be held in closed condition by the magnetic force induced about
a grounded coil 401 which from a terminal 403 is connected to
heretofore defined circuit wire 359 through a voltage lowering
resistance 405. However, switch 397 can also be released by
breaking the circuit to coil 401 by depressing a normally closed
interruptive switch 407 disposed in the circuit of said last
coil.
Upon initial closure of switch 397 both of its terminals 409 and
411 become operatively connected to rectifier terminal 287 through
circuit wire 359. In turn terminal 409 is connected to a grounded
lamp 413 which accordingly will light when switch 397 is closed to
indicate the closed condition of such last switch. The other pole
411 energizes grounded coil 415 of relay assembly 417. The latter
assembly includes the aforementioned relays 347 and 385 and an
additional and normally closed relay 419. Accordingly, when coil
415 is energized by reason of closure of switch 397, switch 386 of
relay 385 will be magnetically moved to closed condition while the
switches 349 and 420 of relays 347 and 419 will be magnetically
moved to open condition. Relay 419 is connected in series with the
circuit of the centrifuge motor (not shown) and accordingly when it
opens the centrifuge will stop. Relay 347, because of its
interposition between terminal 287 and coil 345, will interrupt the
circuit to said last coil when open. Accordingly, magnetically held
switch 339 will be released and current flow to lamp 360 will
terminate. In consequence lamp 360 will extinguish, relays 369 and
371 will open and relays 297 and 303 will be restored to a closed
position. As a result, pump action will stop (because relay 371 is
open); solenoid 239 will be deenergized (because relay 369 is open)
and solenoids 241 and 243 will become deenergized (by reason of the
opening of the respective of relays 297 and 303).
By reason of the foregoing construction controlled washing volumes
can be forced into each of containers 37 and 38 notwithstanding
different resistances to flow in said containers. In prior devices
while the total wash volume can be controlled, the volume to each
container is uncontrollable because differential resistance in the
containers causes the paths of wash fluid which comes from a common
pressure head to move in an uncontrolled fashion. In consequence of
the invention, simultaneous washing of a plurality of batches of
particles can be achieved in a period substantially no longer than
the time required for washing a single batch. Thereby, for the
first time there is provided a washing centrifuge assembly
practical for simultaneous processing of a plurality of batches of
materials.
The process described has been practiced effectively in
reconstituting thawed red blood cells which theretofore had been
preserved by freezing and protected from freeze damage by various
cryoprotective agents. Among the latter which have been removed are
glycerin, an intracellular agent used in high and low
concentrations, and polyvinyl pyrrolidone, an extracellular
agent.
For removal of glycerinating agent from highly glycerinated frozen
red blood cells, a pair of batches, each of which comprises the
yield of 500 milliliters of whole blood, is first thawed and
thereafter spun in a high speed centrifuge for a period sufficient
for separating the cells and available liquid. The supernatant is
then removed and the red blood cells of each batch are transferred
to one of containers 37 and 38, respectively, for processing in
accordance with the invention.
A first wash solution, preferably an aqueous manitol-saline, for
osmotically shrinking the red blood cells and thereby increasing
their density, is first forced through each batch by independent
pressure means for a period sufficient to condition the cells for
ready separation from environmental fluid when centrifuged.
Thereafter, a second wash solution having a decreasing
concentration or gradient of cell shrinking agent is used to
gradually decrease the level of cellular shrinkage to a nullity as
a density differential between cells and environmental fluid can be
maintained under centrifugal force without said agent. After the
manitol has been completely dissipated the cells will restore to
normal size and washing may be completed with hypertonic wash
solution of about 5 percent glucose in normal saline. The foregoing
procedure suitably reconstitutes frozen red blood cells for use in
transfusion.
The hypertonic solution may omit the 5 percent glucose in which
event the decreasing manitol gradient may be established with
isotonic saline. Moreover, if desired, the original wash solution
may be omitted and all washing may be done with normal saline or
the hypertonic solution. In such event, however, great care should
be exercised to avoid high red cell loss during initial periods of
washing. Such likelihood is minimized by manitol in the first wash
solution which causes an osmotic squeeze on the red cells. Thereby,
cell density is increased enabling improved separation of red cells
from the less dense glycerinating agent for removal with
effluent.
As many substitutions or changes could be made in the above
described construction and process, and as many apparently widely
different embodiments of the invention within the scope of the
claims could be constructed without departing from the scope and
spirit thereof, it is intended that all matter contained in the
accompanying specification shall be interpreted as being
illustrative and not in a limiting sense.
* * * * *