US 3561672 A
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.
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I United States Patent m1 3,561,672
 Inventors Charles A. Schlutz  References Cit d g k Ch I UNITED STATES PATENTS z 'g g fgf ffi 2,906,453 9/1959 Driscoll 233/28 A I No 595 3,244,363 4/l966 Hein 233/26  fg 18 1968 3,347,454 10/1967 Bellamy... 233 17 9  Patented Feb.9, 1971 Primary ExaminerRobert W. Jenkins  Assignee Baxter Laboratories, Inc. Attorneys-Walter C. Kehm and Richard J. Reilly Morton Grove, III. a corporation of Delaware WASHING PROCESS AND CENTRIFUGE ASSEMBLY 22 Claims, 12 Drawing Figs.
US. Cl 233/17, 233/ l 9 Int. Cl B04b 5/02 Field of Search 233/17, 26,
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.
PATENIEIDVFEB 9mm SHEET 1 OF 4 INVE snows CHARLES A. ScHLur STANLEY J. SEDIVY CHARLES R. Msmmnor J, A w.
PATENTEU FEB 9 l97| SHEET 3 OF 4 I62 INVENTOR$ CHARLES A.SCHLUTZ.
STANLEY J. SEDW CHARLES R. MEMHAROT 521, W}.
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SHEET UF 4 EEREG 5:550 E INVENTORS CHARLES A. ScHLuTz STANLEY J. SEDWY CHARLES R.MEMHAROT 1 Wy. W A'r'rv.
PATENTEU FEB 9 I97! l WASHING PROCESS AND CENTItIFUGE ASSEMBLY 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 b!ood 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 US. Pat. 2,906,453. The
other thereof embodies the teachings of US. 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 av plurality of batches of preserved red blood cells simultaneously. That is to say, while simultaneous multibatch washing could be practiced in ac cordance 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 no'r' conventionally practiced, except experimentally. The inefficiencies result from differential resistance to flow of wash fluid generated in material comprising the batches 7 simultaneously being processed. The phenomenon is such that wash fluid in ever increasing volume flows throughone 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. J
Moreover, it is an object of the invention to prevent inefficient material separation resulting from differential resistance to flow in a plurality of batchesduring 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. I 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 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 tothc 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"viewaccording 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 I0- I0 of FIG. 9.
FIG. 11 is a view according to the line 11-" of FIG. I, a medial part being broken away.
FIG. 12 is a scheme of wiring for said assembly.
Referring now more particularly to FIG. I, there is shown a washing centrifuge assembly I5 comprised of a housing or outer shell I7 only an upper portion of which is shown. Within chamber 19 of shell 17 a centrifuge rotor 21 is concentrically disposed for rotation. Rotor 2I 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 ecccntrically from adjoining 1 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 pairsof 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, l 25, assigned to the assignee of the presentapplication.
Container means comprising aplurality 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 I for an associated of containers 37 and 38. A cap 4! for each of receptacles 23 and 24 has apair 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. I 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 SI (FIGS. I, 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 and that the showing of both conditions in each view is solely for the purpose of illustrating alternate extremes, which normally will notbe 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 I0, 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. l
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 (FIGS. '1, 4 and 5) carried from the lower wall 99 of rotor 97 is removably keyed or snugly en' gaged 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 IOI-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 is less than the inside diameter of rotor 97 by reason of which a space I13 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 cup 101.
Chamber defining means comprise a plurality of annular flexible sealing members 115, 117, I19 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 I23, 125, 127 and 129. Thecircumferences of the sealing members snugly engage the inner surface of rotor wall I07 while the inner surfaces of said sealing member snugly engage the outer surface of stator 105. Thereby each of chambers I23, I25, 127 and 129 is sealed from the others thereof and is defined by an inner wall comprising a section of stator I05 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 I23 and 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 I27 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 1350f 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, I41
and 143 (FIGS. 4, 5 and 6) which open through the top of stator head 11]. The lower ends of bores 137, 139, 141 and I43, respectively, communicate with chambers 123, I25, 127 and 129. By reason of the foregoing, bores 137 and 139 are influent bores whereas bores 14] and 143 are etfluent 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 and147. 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 11] 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. I) 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.
1n 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 H6. 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 he form of a rod 201 which extends through a transverse 0;- ming 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 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 seeurance 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 (HQ 12) for connecting the power circuit 275 of the assembly to a l l 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-tobreak, 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 3135, which may be carried from a switch box 307, will light by reason of connection to one terminal 237 of rectifier 231 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 cl Jsed relay 297. The other terminal 299 of solenoid 243 is cmnected 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 3211, switch 329 of relay 325 and switch 239, which are both magnetically coupled to the coil 327, respectively, will close and open. When the switch 239 opens, current flow to solenoid 239 as well as to coil 3119 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 lnfluent 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 32.5 is connected to terminal 237 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 con' tainer 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 thatwhen 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 381) of said relay 369 is connected to the plane of reference potential through a circuit sembly 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 337 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 3119 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 2M and 2413 are energized, pump 153 is also actuated by reason of closure of relay 371 which is serially connected between a pair of l 15 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-malte, push-to-brealt 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 40] 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 cplls 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 decrea neg 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.
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. in cluding 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 con tainer 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.
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.
iii. 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.
1!. 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 H2 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 otand in substantially the same volume as influent moved, a combina tion comprising: a body corotationally secured to said first rotor for securing said charging and discharging means to said first rotor, and a disposable distributorcollector 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 16. 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.
22. A process according to claim 20 in which the wash fluid is forced through said batches substantially simultaneously,
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