US2906453A - Washing centrifuge - Google Patents

Description

Sept. 29, 1959 s, n sco ETAL 2,906,453

WASHING CENTRIFUGE Filed April 12, 1955 4 Sheets-Sheet J.

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Spt. 29, -1959 s. e. DRISCOLL ErAL 2,906,453

' WASHING CENTRIF'UGE Filed April 12, 1955 4 Sheets-Sheet z S. G. DRISCOLL ETAL WASHING CENTRIFUGE 141k 711524405141- fl/vo BULB Com asses Sept. 29, 1959 Filed April 12, 1955 Sept. 2-9, 1959 s, DRISCOLL- EI'AL v 2,906,453

' WASHING CENTRIFUGE Filed April 12, 1955 4 Sheets-Sheet. 4

.-V///////////J7////A villi/III) WASHING CENTRIFUGE Shirley G. Driscoll, Brookline, Douglas M. Surgenor,

Wayland, and James L. Tullis, Newton, Mass., assignors to Protein Foundation Incorporated, Cambridge, Mass., a corporation of Massachusetts Application April 12, 1955, Serial No. 500,753

' 7 Claims. (Cl. 233-28) This invention relates to centrifugation and, more particularly, to centrifugal apparatus useful in the separation of the various components of animal blood, though it may equally well be used in the separation of components, having different specific gravities, of other liquids.

In US. patent applications Serial Nos. 281,988, and 281,989, filed April 12, 1952, and of common ownership with the present application, now Patent No. 2,822,126, and No. 2,822,315, respectively, are described both centrifugal apparatus and methods of separation of tremendous value in effecting separation of the cellular components of animal blood from plasma, as well as in the separation of the various protein constituents of plasma.

The present invention is directed to improvements in such apparatus, which provide improved separation, sterility, and ease of operation. More specifically, it is a particular object of the present invention to provide novel continuous feed centrifuge bowl structures for carrying out various separations of the elements of whole blood, that is, red blood cells, white blood cells, platelets and plasma which differ in specific gravity, as well as to separate such components from other liquids, and especially the collection and washing of red blood cells.

It is a particular feature of the invention that the centrifuge bowl structures provided have interchangeable parts wherein desired bowl structures may readily be assembled.

Various other objects and features of the invention will become apparent from the following description of preferred embodiments thereof, together with the accompanying drawings, wherein:

Fig. 1 is an isometric view, partly broken away, showing the apparatus of the invention;

Fig. 2 is an exploded isometric view of a portion of the apparatus of Fig. 1;

Fig. 3 is an enlarged detail view, partly in cross section of a portion of the apparatus of Fig. 1;

Fig. 4 is a partial cross-sectional view of the apparatus of Fig. 3, taken on the line 4--4 thereof;

Fig. 5 is an enlarged detail cross-sectional view of another portion of the apparatus of Fig. 1;

Fig. 6 is a diagrammatic view of the cooling system of the apparatus of Fig. 1;

Fig. 7 is a cross-sectional view showing the interior structure of the centrifuge bowl;

Fig. 8 is a cross-sectional view of the structure of Fig. 7;

Fig. 9 is a diagrammatic view showing the operation of the bowl structure of Figs. 7 and 8. In Fig. 1 is shown the general arrangement of the apparatus, and in particular the elevator mechanism for United States Patent ice The elevator mechanism is mounted on main frame supporting plate 10 and is actuated by handles 12, which handles extend through slots 20 in the front panel 11 of the apparatus. Said handles form one leg of a first bell crank pivoted at 14 on plate 10, the other leg of which is connected through link 15 to one leg of a second bell crank pivoted at 16 on said plate. The other leg of said second bell crank is connected by a short link 17 to elevator rod 21. behind catch 18 in spring 19, which latter is pushed into slot 20 in front panel 11. Handle 12 is thereby releasably held in raised position during the centrifuging. The raising of handle 12, through theabove described linkage system, causes elevator rod 21 to move upwardly, carrying with it a supporting assembly which consists of sliding elements 23 attached to said rods, supporting pins 24 mounted thereon, spring 25 and spring supporting rod 26 mounted on said elements. The slides 23 slide on tracks on elevator posts 27 affixed to and extending downwardly from plate 10. Four adjustable stops 28, 28' are provided for limiting the upward travel of the supporting assembly of which three are shown, two of said stops 28 being mounted on plate 10 and two of said stops 28 on elevator posts 27. These are provided with threads so that they can be positioned as required.

On the right hand side of Fig. 1 is shown the centrifuge bowl, its driving mechanism, and its supporting structure. The latter supports the bowl and also holds the collecting receptacles (not shown).

The centrifuge bowl will be later more fully described, but in general includes a top bowl 30 of generally conical shape, a bottom bowl 32 also of conical shape, an intermediate ring 60 therebetween; and a compression arrangement including outer compression ring 34 holding the two bowls and the ring together. The bowlsand other elements which come in contact with blood are preferably of stainless steel with a silicone coating. The bottom bowl 32 is rotatably mounted on a base which consists of a table portion 36 with a cylindrical rim 38 remo-vably mounted therein for directly supporting lower bowl 32. A frame 37 extends downwardly from table portion 36. Said table portion is supported on spaced apart pins 24 with frame 37 bearing against spring 25.

The driving mechanism for the bowl consists of a magnetic chuck 40 rotatably mounted on supporting plate 10 and driven from a suitable electric motor (not shown). The chuck 40 includes an annular bottom surface having mounted therein in suitable non-magnetic material, a plurality of magnets adapted to contact the upper surface of compression. ring 34. A driving pin 48 is mounted in said annular bottom surface for engaging driving slot 49 in compression ring 34 to positively drive said bowl. To assemble the structure, frame 37 carrying table 36 is first placed on frame locating pins 24, as shown in Fig. 1. The elevator mechanism is then actuated by raising handle 12 until table 36 hits the outside stop 28. Further slight raising of handle 12 brings the frame in contact withinside stop 28', thereby compressing spring 25 and locating the top bowl 30 in proper relation to chuck 40.

Fig. 3 shows the detail of the bowl hold-down assemblies which consist of a clamping dog 50, a compression spring 52, a locating pin 54 mounted on said dog, a supporting rod 56 on which said dog and spring are mounted, a cam 58 and an actuating lever 59. As shown in Fig. 3, if lever 59 is rotated so that the fiat face of cam 58 (Fig. 4) is at the top in contact with a lower surface of table 36, compression spring 52 will lift dog 50 away from lower flange 29 of bottom bowl 32. Pin 54 is provided in order to assure the centering of the bowl.

In assembling the equipment for operation, the parts of the centrifuge bowl are assembled as shown in Fig.

When handle 12 is in raised position, it slips ample.

1, and the assembled structure is then clamped by dogs 50 (of which two are provided for each bowl). The bowl is then raised by the elevator mechanism, as already described, in to the proper position with respect to chuck 40. Dog 50 is then released by moving levers 59 so that the bowl can be spun.

With the multiple piece centrifuge bowl as herein described, it is important that a fluid tight seal be provided between the top and bottom centrifuge bowls and the intermediate ring. Thus, as shown in Fig. 4, the top bowl 30 has an outwardly extending annular flange 31 at its lower edge, and the bottom bowl 32 has a similar flange 33 at its upper edge. A supporting memher for internal elements of the centrifuge, as hereinafter described, comprising an annular ring 60, is interposed between the flanges, and suitable sealing means comprising rings 62 are interposed between ring 60 and flanges 31, 33 respectively. Spacing rings 64 are also interposed between ring 60 and flanges 31, 33 radially inwardly of the 0 rings 62 to limit the movement of flanges 31, 33 toward one another, said spacing rings being of a dimension somewhat less than that of the uncompressed 0 rings 62. Thus, a predetermined overall dimension of the assembled centrifuge can be provided, yet with adequate sealing. The opposed flanges 31, 33 are urged together by outer compression ring 34 and an inner cooperating locking ring 66, the outer compression ring having an inwardly extending flange which fitsover top bowl flange 31. The downwardly extending skirt of said compression ring is screw threaded on its inner surface to cooperate with the screw threaded outer surface of locking ring 66, the upper surface of said latter ring contacting the bottom bowl flange as it is screwed into place to clamp flanges 31, 33 together.

Figs. 7 and 8 show the centrifuge bowl structure and Fig. 9 the operation of said bowl structures wherein the left half shows the bowl running for the collection of one blood component, and the right half the bowl stopped or decelerating for collection of another component.

As to the bowl structure best shown in Fig. 2, the parts of the bowl are assembled on a cylindrical flanged base assembly consisting of base member 35 with a surrounding tubular member 41 having an inwardly extending flange 43 positioned beneath the outer periphery of base member 35 to support said base member therein, said assembly being adapted to fit into an opening in table 36 with its outer flange 45 interposed between said table and removable rim 38 to support the base assembly on said table. The upper surface of the rim 38 acts as a running surface for a sealing member 67 of lowfriction material, said sealing member being supported between said rim and flange 29 by a skirt 68 thereon. A waved spring washer 69 and underlying flat washer 69 are provided interposed between said sealing member and said flange. Spring washer 69 controls the pressure therebetween when clamping ring 34 is tight and hence when the bowl is properly assembled), with flange 29 in driving engagement with lower bowl 32. A suitable O ring seal is provided between member 67 and skirt 68.

The base 35 has mounted centrally thereof an upstanding stationary feed tube housing 80, said housing 'having slidably mounted therein a feed tube 82 with a compression spring 84 interposed between said feet tube and said base to normally urge said feed tube upwardly. The feed tube extends downwardly through base 35 to a suitable connector so that blood from a donor or other reservoir may be fed to the centrifuge. An upstanding circular flange 39 is provided on the base, such flange being spaced between the inner and outer radial extent of the base. A plurality of openings are provided in said base in addition to said central opening for carrying away liquids discharged from the centrifuge to suitable glass or plastic containers, for ex- Thus inner openings having downwardly ex- 4 tending tubes 86 are provided in base 35 between its flange 39 and feed tube housing 80, one or more openings 87' having tubes 87 are provided in said flange surace, and an opening 88' having a vent tube 88 is provided in said base outwardly of flange 39 within lower bowl 32.

Figs. 7 and 8 show a centrifuge structure particularly adapted for red blood cell washing, as by glycerol. In this arrangement, the central baflle is of dished shape, extending entirely across the centrifuge and has four openings therein, a central opening 122 of somewhat larger diameter than that of feed tube 82, and three openings spaced outwardly therefrom, each of said three openings having mounted therein, as by suitable nuts, a spacing tube 124 having its flange adjacent the upper surface of baffle 120. A cylindrical skirt 126 extends downwardly from said battle between said central opening and said openings spaced therefrom. An upper circular baffle 128 having holes therein corresponding to said three openings is mounted on spacing tubes 124 with its lower surface spaced from the lower baffle 120 by the flanges of said tubes 124, said upper baflie having its outer rim extending to just short of the outer wall of the centrifuge. The feed tube 82 extends through opening 120 in the central baflle to the lower surface of upper baflle 128. A cylindrical skirt 129 surrounds the openings in the upper bafiie and extends upwardly toward the top wall of upper bowl 30. This arrangement in eflect forms a composite baffle having a central recess into which feed tube 82 extends, with radial passages extending outwardly to a point on the top surface of the baffle adjacent the inner surface of the top bowl 30, and axial passages extending therethrough displaced from the axis of the centrifuge bowl. The upper cylindrical skirt 129 is spaced outwardly from said displaced passages and the lower skirt inwardly therefrom. Downwardly extending tubes are provided mounted within two of said spacing tubes 124 and an upwardly extending vent tube 127 within the third. Said downwardly extending tubes 125 are positioned radially inwardly of outer collecting ring 92 and outwardly of inner collecting ring 94. Downwardly extending skirt 126 is positioned radially inwardly of inner collecting ring 94.

The operation of the structure of Figs. 7 and 8 is shown in Fig. 9. The blood is passed upwardly through central feed tube 82 and outwardly through the radial passages of the central baflle. The red blood cells, as before, collect and the other blood components pass over the top of skirt 129, downwardly through tubes 125 and along the inner surface of outer collecting ring 92 and thence through tube 87 to a suitable container. When the red blood cell compartment is filled with red blood cells, the flow of blood through feed tube 82 is stopped and a glycerol solution is passed through said tube to glycerolize the red blood cells, the glycerol being of lighter density than the glycerolized cells, rises to the inner axis of the centrifuge and overflows. After the cells have been glycerolized, the centrifuge is decelerated and the glycerolized red blood cells will then pass radially inwardly through the radial passage in the central bafile and downwardly through central opening 122 and tubes 86 to a suitable container. The glycerolized red blood cells may then be frozen and may be preserved in that state.

Whenever it is desired, then, to use the so preserved glycerolized red blood cells, they are deglycerolized by centrifuging. Thus, they are passed upwardly through central feed tube 82, and outwardly through the radial passages of the central baflle and are maintained adjacent the outer wall of the centrifuge. A washing liquid is 'then passed through feed tube 82 and deglycerolizes the cells, the washing liquid and glycerol passing over the top of upper skirt 129, downwardly through the displaced tubes 125, and thence through tube 87 to a suitable container. The red blood cells can be washed by asmuch liquid as desired, and such liquid will pass through the collected mass of red blood cells before being discharged. When the centrifuge is decelerated, the collected red blood cells will pass radially inwardly through the passages in the central baflle, and downwardly through central opening 122 and tubes 86 to a suitable container.

This structure is particularly effective in providing washing of a material collected therein by any desired quantity of sterile washing liquid. Thus, such closedsystem sterility makes the structure useful in many types of sterile washing procedures, since the volume of wash solution is not limited by the'volume of the centrifuge. As will be apparent from the above description, the centrifuge elements may be assembled with a variety of internal centrifuge elements to provide separation of the cellular components of blood or other biological fluids, such as milk. Also, the separation of many other liquids, emulsions, and suspensions may be accomplished by these centrifuge structures, since a difference in the specific gravity of the components to be separated is all that is required. Furthermore,. more than one component may be rapidly separated by using more than one centrifuge. Thus, with the two unit arrangement as shown in Fig. 1, one of the centrifuge bowls may be used to separate the red blood cells, and the plasma with other components may be passed directly to the second centrifuge bowl to separate a further component. This arrangement could be readily extended to separate continuously even more components by using more centrifuge bowls assembled with the proper interior elements. For stability of the separated blood components, it is important that the blood be kept cool, and that it be cooled before it passes from the donor into the centrifuge. Thus, as shown in Fig. 6, a refrigeration unit is associated with the apparatus both to cool the blood before it enters the centrifuge bowl and to air cool the compartment housing the centrifuge assemblies. Freon or other refrigerant is compressed in compressor 70, cooled in after-cooler 71, passed through receiver 72 and drier 73 and split into two streams shown in the drawings as 74 and 75. Stream 74 is expanded and cools bath coil 76 which cools the blood from the donor prior to sending it to the centrifuge operation. The expanded refrigerant then passes through back pressure regulator 77 and thence back to the compressor. Stream 75 passes through evaporator 78 where it cools the air inside the apparatus around the bowl. It then returns to compressor 70. The bath coil is at a higher temperature than that in evaporator 78. Thus the pressure of the refrigerant is always controlled in line 74, by regulator 77 (since the pressure in the bath coil will be higher than that in evaporator 78). The solenoid 79 is actuated by the thermostat and opens when the air temperature rises. The compressor runs continuously, and if there is no load on the system, it merely discharges into the receiver 72. By this arrangement it is possible to use a single compressor to provide two different temperatures which are controlled independently of each other.

To summarize the operation of the above described apparatus, assuming that blood is to be taken from a donor and that the red cells are to be removed therefrom, the centrifuge bowl is first assembled. Suitable containers are then connected to its outlet tubes and it is then sterilized with steam. It is then mounted on table 36 as shown in Fig. l. The elevator mechanism is then operated to raise the centrifuge bowl upwardly to its driving mechanism, and dogs 50 are then released so that the bowl will be released with lower bowl 32 in driving contact with flange 29 and upper bowl 30 seated in chuck 40 and held therein by magnets 44. The chuck 40 is then rotated to spin the bowl. Blood from a donor is first passed through a resin column or a reservoir of any desired anti-coagulant solution to prevent coagulation, then cooled, and finally passed into the spinning centrifuge. The red blood cells will collect as above dee scribed until they fill the red cell compartment. During this time, the plasma and other blood components pass through the centrifuge into their container. When the red cell compartment is filled, the centrifuge is decelerated and the red cells allowed to drain into another container.

The centrifuge bowl is then stopped and disengaged from its driving mechanism by clamping dogs 50 to pull it away from chuck 40 and then lowering it by the elevator mechanism. The containers may then be removed and the centrifuge bowl taken apart for cleaning.

Thus, it is apparent that the invention has provided a novel apparatus for separating components from blood during the actual phlebotomy, which apparatus results in improved separation, closed-system sterility and ease of operation. Various modifications of the apparatus, not herein disclosed, within the spirit of the invention and the scope of the appended claims will occur to those skilled in the art.

We claim:

1. A' centrifuge comprising a bottom bowl and a closed top bowl, said top bowl having a central opening therein, and an outwardly and downwardly flaring conical side wall, a stationary base positioned beneath said central opening, sealing means interposed between said base and said bowl, an internal centrifuge element having a central' baflle consisting of a fiat circular plate fitting within said bowl, a central recess extending upwardly into the bottom surface of said battle, a radal passage extending radially outwardly from said central recess to a point on the top surface of said bafile adjacent the inner surface of said bowl, and a displaced axial passage extending through said baffie, and an upwardly extending tubular skirt spaced radially outwardly from said axial passage and radially inwardly from the opening of the radial passage on the top surface of the baffle, stationary feed means extending upwardly from said base centrally through said bottom opening into said recess for feeding liquid into said centrifuge through said radial passage, collecting means disposed below said bottom opening for collecting liquid discharged from said centrifuge, said centrifuge being adapted for rotation about a vertical axis whereby liquids discharged from said centrifuge during spinning thereof may be collected separately from liquids discharged when said centrifuge is stopped.

2. A centrifuge as claimed in claim 1 wherein said collecting means includes a plurality of concentric collecting rings mounted on said base, and openings through said base are Provided between said rings and between the innermost ring and said feed means.

3. A centrifuge comprising a bottom bowl having a central opening therein, a side wall, and an outwardly extending annular flange at the upper edge of said wall, a stationary base positioned beneath said central opening, sealing means interposed between said base and said bottom bowl, a top bowl having a top wall, an outwardly and downwardly flaring conical side Wall and an outwardly extending annular flange at the lower edge of said wall, an internal centrifuge element having a central bafile consisting of a fiat circular plate with its annular edge positioned between said opposed flanges, a central recess extending upwardly into the bottom surface of said baffle, a radial passage extending radially outwardly from said central recess to a point on the top surface of said bafile adjacent the inner surface of said top bowl, and a displaced axial passage extending through said bafile, an upwardly extending tubular skirt spaced radially outwardly from said axial passage and radially inwardly from the opening of the radial passage on the top surface of the baffie, clamping means for clamping said flanges toward one another into firm pressure contact with said central baflle to seal said centrifuge, stationary feed means extending upwardly from said base centrally through said bottom Opening into said recess for feeding liquid into said centrifuge through said radial passage, collecting means disposed below said bottom opening for collecting liquid discharged from said centrifuge, said centrifuge being adapted for rotation about a vertical axis, whereby liquids discharged from said centrifuge during spinning thereof may be collected separately from liquids discharged when said centrifuge is stopped.

4. A centrifuge as claimed in claim 3, wherein said central bafile comprises a lower baffle of generally circular shape with its annular edge positioned between said opposed flanges and having a central opening and a displaced opening, an upper baffle spaced upwardly from said lower baflie with its annular edge extending to a point adjacent the inner surface of the top bowl and having a displaced opening therein, and means connecting said displaced openings to provide an axial opening through said central bafile.

5. A centrifuge as claimed in claim 3, wherein three axial passages are provided.

6. A centrifuge as claimed in claim 3, wherein said means for collecting liquid discharged from said centrifuge includes an outer collecting ring extending upwardly from said base beyond the lower extent of said axial passage and spaced radially outwardly therefrom, and an inner collecting ring extending upwardly from said 'base and spaced radially inwardly from said axial passage and radially outwardly from said central recess, and openings in said base between said inner and outer collecting rings, and between said inner collecting ring and said feed means.

'7. A centrifuge as claimed in claim 6, wherein said internal centrifuge element further includes a downwardly extending tubular skirt spaced radially outwardly from said recess and radially inwardly from said inner collecting ring, and with its lower edge extending below the upper edge of said inner collecting ring, and a pipe extends downwardly from said axial passage in said baflle between said inner and outer collecting rings.

References Cited in the file of this patent UNITED STATES PATENTS an-w-

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