US3674197A

US3674197A - Washing means for flexible bags in split enclosures

Info

Publication number: US3674197A
Application number: US70273A
Authority: US
Inventors: David F Mitchell; William A Romanauskas
Original assignee: IVAN SORVALL Inc
Current assignee: IVAN SORVALL Inc
Priority date: 1970-09-08
Filing date: 1970-09-08
Publication date: 1972-07-04
Anticipated expiration: 1989-07-04

Abstract

Improved enclosure for supporting flexible bags within a centrifuge rotor for washing biological particles in a closed system. Each collapsible bag is enclosed and supported by a juxtaposed pair of half-shells forming a unitary cavity or chamber to which the filled bag conforms during centrifugation. The enclosure serves to prevent undue wear and stress upon the rotor receptacle and, at the same time, safeguards the integrity of the flexible bag during centrifugation.

Description

v .United States Patent Mitchell et al.

[54] WASHING MEANS FOR FLEXIBLE BAGS IN SPLIT ENCLOSURES [72] Inventors: David F. Mitchell, Trumbull; William A.

Romanauskas, Southbury, both of Conn. [73] Assignee: Ivan Sorvall, lnc., Newton, Conn. [22] Filed: Sept. 8, 1970 [2] 1 Appl. No.: 70,273

[52] US. Cl. ..233/l4 R, 233/26 [51] Int. Cl ..B04b 15/02 [58] Field ofSearch ..l28/2l4 R, 214A; 233/26, 1 R, 233/19 R, 19 A, 14 R [56] References Cited UNITED STATES PATENTS 3,096,283 7/1963 Hein ..233/26 X 51 July4,l972

Primary ExaminerJordan Franklin Assistant Examiner-George H. Krizmanich Attorney -I. Jordan Kunik [57 I ABSTRACT Improved enclosure for supporting flexible bags within a centrifuge rotor for washing biological particles in a closed system. Each collapsible bag is enclosed and supported by a juxtaposed pair of half-shells forminga unitary cavity or chamber to which the filled bag conforms during centrifugation. The enclosure serves to prevent undue wear and stress upon the rotor receptacle and, at the same time, safeguards the integrity of the flexible bag during centrifugation.

11 Claims, 7 Drawing Figures PATENTEDJIJL "4 I972 3,874,197

sum 1 or a INVENTORS DAVID F. MITCHELL Y WILLIAM A. ROMANAUSKAS ATTORNEY PATENTEDJUL ,4 m2 3.6T4..l97

FIG. 3

INVENTORS DAVID F. MITCHELL BYWILLIAM A. ROMANAUSKAS WWW A ORNEY PATENTEnJuL 41912 3.674. 191

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; l2 1/ k u INVENTORS DAVID F. MITCHELL W LIAM A. ROMANAUSKAS 8, M. M

ATTORNEY BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a novel apparatus for centrifuging and washing biological particles and the like, and more particularly to a separable enclosure for supporting a flexible bag through which the washing and centrifugation process takes place when said bag is confined in the cup or receptacle of a spinning centrifuge rotor.

2. Description of the Prior Art When soft, flexible bags are inserted into respective cups of a centrifuge rotor, there is encountered the problem of properly supporting each of the liquid filled bags as they are continuously rotating. The bags are subjected to various pressures and forces during centrifugation whereby they are not evenly distributed within their respective cups of the rotor. Thus, shifting of position or other movement of the bags relative to the walls and bottom of their respective cups causes wrinkles and folds in the bag material with the consequent imbalancing of the rotor due to the resulting change in volume. Furthermore, these disadvantages are aggravated when there is no element on top of the bag to maintain it in position in its respective cup during the spinning of the rotor and to prevent undue expansion of the flexible bag which would otherwise cause the top of the bag to extend above the top of its cup thereby interfering with the centrifuging process, or causing the bag to rupture.

Some attempt has been made to overcome these disadvantages by providing a removable shaped support element on the bottom of the rotor cup which accommodates the shaped bottom contour of the centrifuge bag while, at the same time, a removable weight element is placed on top of the flexible bag within each cup to prevent the bag from being dislodged during centrifugation from its cup. The drawback of the bottom shaped support element is that the apex thereof frequently produces a highly stressed area upon the bottom of the rotor cup during high speed centrifugation. As for the weight element that is superimposed on top of the flexible bag, said weight, if not of sufficient mass, can be pushed upwards and out of the rotor cup during the filling of the bag which, being flexible, is capable of expansion. Said weight appreciably adds to the total force exerted on the rotor thereby decreasing the usable volume or operating speed of the rotor. Placement of the soft flexible bag within the rotor recess without folds or wrinkles requires considerable care on the part of the operator, who is then faced with the task of properly positioning the top weights before this portion of the operation is complete.

Continuous washing centrifugation of particles in a closed system utilizing flexible bags is disclosed in United States Pat. Nos. 3,347,454 and 3,211,368.

SUMMARY OF THE INVENTION The disadvantages and drawbacks of the prior art have been overcome by applicants novel invention wherein the flexible bags are completely enclosed in paired half-shell elements which not only support the bag within the rotor cup or receptacle, but also provide for distributing the weight of the bag over substantially the whole area of the floor of the receptacle. At the same time, undue expansion of the flexible bag at the top thereof is also prevented by the single enclosure which is also appropriately formed to accommodate the inlet and outlet tubes communicating with the flexible bag in the interior of each enclosure. Furthermore, by providing the flexible wash bag with a strong but lightweight enclosure which ensures the confinement of the bag within its rotor cup, considerably higher speeds of centrifugation can be achieved than those possible with prior art arrangements. Insertion of the bag in one-half section and placement of the other half over this combination results in a firm, rigid, easily handled assembly that can be readily inserted into or removed from the rotor body.

These and other novel features. present invention will be described ing specification and claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the container assembly of a pair of half shells in the unitary cavity of which is lodged the flexible centrifuge bag;

FIG. 2 is an exploded view in somewhat reduced size of the device in FIG. 1 showing the internal cavities of the respective half shells and the blood washing bag that fits into the combined cavities thereof;

FIG. 3 is a schematic vertical section view of a centrifuge rotor and enclosure illustrating the manner in which pairs of halfshell enclosures are inserted into respective rotor cups and showing the fluid transfer means for transmitting washing liquids continuously through the washing bags located within half shell enclosures;

FIG. 4 is an enlarged view taken on line 4-4 of FIG. 3;

FIG. 5 is a further enlarged exploded elevation view of the half shell elements shown in FIG. 2, with a section view of the washing bag shown located in the cavity of one of said half shells;

FIG. 6 is a somewhat reduced view taken on line 6-6 of FIG. 5; and

FIG. 7 is a bottom view of the combined half shells in a size comparable to that shown in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in detail, the apparatus of the present invention comprises a pair of semi-circular half shells, generally designated 11 and 12, respectively, injection molded or otherwise formed of a suitable inert thennosetting or thermoplastic material such as Noryl, a thermoplastic material with or without fiberglas filler, made by General Electric Co., or other suitable material. Shells l1 and 12 are substantially identical structurally except for several portions thereof which will be described hereinafter.

Each shell 11 and 12 has a

semi-cylindrical cavity

13 and 14, respectively, the lower portions of which terminate in half conical cavities l6 and 17, respectively.

Cavities

13 and 14 are bounded on their vertical sides by

ribs

18 and 19, respectively, while semi-conical cavities l6 and 17 are bounded by

ribs

21 and 22, respectively.

The top portions of cavities l3 and 14 are bounded by

semiconical shoulders

23 and 24, respectively, which in turn are bounded by

ribs

26 and 27, respectively.

Ribs

21 and 26 are each provided with a pair of integrally molded, spaced apart pins 28, while

ribs

22 and 27 are each provided with integrally molded spaced apart recesses 29. Said pins 28 and said recesses 29 cooperate with each other to align shells II and 12 in respect of each other to form a unitary symmetrical cylin drical cavity composed of the combination of cavities l3, l6, and shoulder 23, with

corresponding cavities

14, 17 and shoulder 24, while ribs 18, 21 and 26 mate with corresponding

respective ribs

19, 22 and 27.

Formed in the top of shells l l and 12 are semi-circular

conical collars

31 and 32, respectively. Communicating between cavity 23 and collar 31 is an axially positioned semi-cylindrical aperture 33, and communicating between cavity 24 and collar 32 is an axially positioned semi-cylindrical aperture 34. Laterally spaced apart from aperture 33 to the left (FIG. 2) in shell 11 is a longitudinal semi-cylindrical! aperture 36 which establishes communication between cavity 23 and through collar 31, while laterally spaced apart from aperture 34 to the right in shell 12 is a longitudinal semi-cylindrical aperture 37 which establishes communication between cavity 24 and through collar 32. When shells 11 and 12 are juxtaposed,

apertures

33, 34 and

apertures

36, 37 are aligned with each other to fonn respective unitary passageways whose function will be described hereinafter.

In the region of

apertures

36 and 37,

collars

31 and 32 are formed in

semi-conical contours

38 and 39, respectively, so

and advantages of the and defined in the followthat when said contours are juxtaposed and aligned with each other they fonn a unitary supporting surface for flexible tubing passing therethrough whereby kinking and pinching of said tubing are obviated during centrifugation and whereby full liquid flow will be maintained through said tubing during that operation. 1

Ribs

21 and 22 extend downwardly from

respective recesses

16 and 17 and when juxtaposed, together form a unitary diagonal rib, the bottom of which is contoured to conform substantially to the bottom surface of a receptacle in a centrifuge rotor. Shells 11 and 12 are also provided at the bottom thereof with integrally formed

identical ribs

41 and 42, respectively, (FIG. 7) extending perpendicularly relative to

ribs

21 and 22 and whose thickness and shape are substantially identical with that of combined juxtaposed

ribs

21 and 22. The bottom contour of the combination of

ribs

41 and 42 is identical with the bottom contour of

ribs

21 and 22 for resting upon the bottom of the rotor receptacle, thereby forming a radiating star or cruciform support for shells 11 and 12 within said rotor. It is contemplated that in some embodiments additional ribs may be formed at the bottom of shells 11 and 12 to form symmetrical star arrays for supporting the assembly of said shells in the receptacle of a centrifuge rotor.

While ribs 26 and 27 form a diagonal support structure between

collars

31 and 32 on the one hand, and

shoulders

23 and 24 on the other, there is further provided in shells 11 and 12

vertical ribs

43 and 44, respectively, which are arrayed perpendicularly relative to

ribs

26 and 27. When said shells are juxtaposed,

ribs

26, 27 and 43, 44 form a radiating star or cruciform support structure between

shoulders

23 and 24 on the one hand, and

collars

31 and 32 on the other. See FIG. 6. In some embodiments, additional ribs in symmetrical array may be formed in shells 11 and 12 in star array to form a support structure between said shoulders and said collars In the areas of

semi-cylindrical apertures

33, 34 and 36, 37,

ribs

26, 27 and 43, 44 are somewhat enlarged for reinforcement purposes.

Formed on the outer surface of shells 11 and 12 substantially at the apex thereof are respective

longitudinal flats

46 and 47 which serve to permit venting of air from the rotor receptacle when the combined shells are inserted therein and which permit ready withdrawal whereby vacuum effects are obviated within said receptacle.

The unitary cavity formed by

semi-circular cavities

13, 14 and I6, 17 and 23, 24, when shells 11 and 12 are juxtaposed as in FIG. 1, is intended to be occupied by a soft, flexible, and collapsible blood washing bag 48 or the like made of a flexible plastic material, said bag having a principal cylindrical portion fitting into combined cavities l3 and 14, an integrally formed conical portion 49 at the bottom thereof fitting into combined cavities l6 and 17, and an integrally formed conical top 51 fitting against combined

shoulders

23 and 24.

The size and shape of bag 48 is arranged to conform sub stantially to the contours of the cavities of juxtaposed shells 1 l and 12 when said bag is filled with materials that are being centrifuged and washed therein. At the same time, the juxtaposed shells, when confined in a rotor receptacle, are intended to maintain the contour of said bag and to prevent the latter from expanding.

The top 51 of bag 48 has a pair of upwardly extending integrally formed spaced apart

tubes

52 and 53. Outlet tube 52 is located axially of bag 48 and is extendable through the central aperture formed by combined

semi-cylindrical apertures

33 and 34 in shells 11 and 12, respectively. Inlet tube 53, which is located off-center from tube 52, is extendable through the aperture formed by the combined

semi-cylindrical apertures

36 and 37. Connected with a liquid-tight seal to tube 52 is one end of a flexible outlet connecting tube 54, and connected with a liquid-tight seal to tube 53 is a flexible inlet connecting tube 56.

Inlet connecting tube 56 extends through tube 53 and enters into bag 48 and terminates approximately at the downwardly extending apex of conical portion 49 of bag 48. In other embodiments, inlet connecting tube 56 may terminate at any suitable location intennediate the top and bottom of bag 48, but in all cases the end of said tube will be located at a point farther from the axial center of rotor 58 than that of the juncture of outlet tube 52 with the upper portion of said bag.

The assembly of bag 48 and shells l1 and 12, as shown in FIG. 1, is insertable into a suitable cup or receptacle 57 of a centrifuge rotor 58 (FIG. 3) mounted on and rotated by drive shaft 59 connected to a rotating power source such as an electric motor, turbine drive, or the like, not shown. The assembly of juxtaposed shells 11 and 12 forms a close sliding fit with the interior wall of rotor cup 57. Rotor 58 spins within a protective centrifuge enclosure 60. As shown in the drawings, and particularly in FIG. 3, a pair of shells 1 1 and 12 is removably insertable longitudinally into a corresponding rotor cup 57 with the juxtaposed edges of said shells forming a seam arrayed substantially parallel to the longitudinal axis of said cup.

The diametrical seam 61 between each pair of juxtaposed shells 11 and 12 (FIGS. 6 and 7) is arrayed radially from the axial center of rotor 58 whereby inlet tube 53 of bag 48 is located further from said center than outlet tube 52 while both of said tubes are radially aligned in respect of each other. The requirement for locating inlet tube 56 at a distance further than the outlet tube 52 from the axial center of the rotor is well known in the art. Moreover, the provision in the juxtaposed shells of the spaced apart'apertures through which respective inlet and

outlet tubes

53 and 52 extend, helps to ensure that bag 48 will remain in a stabilized position within said shells and will not shift within the rotor receptacle dun'ng centrifugation as experienced in previous biological and blood cell washing apparatus.

Customarily, the biological cell or blood washing system consists of a pair of identical washing bags 48 that are posi tioned within respective rotor cups 57 which are located 180 apart from each other, as shown in FIG. 3, so as to provide desirable symmetry of weight distribution in rotor 58. The respective inlet and

outlet connecting tubes

54 and 56 of the pair of bags 48 are connected to a rotary seal 62 which schematically represents any one of a number of rotary seals that are known in the art. Rotary seal 62 is connected to a stationary shaft 63 through which inlet supply and

outlet effluent tubes

64 and 66, respectively, are connected. By means well known in the art, rotary seal 62 establishes communication between inlet supply tube 64 and connecting and

inlet tubes

56 and 53 of bags 48, and also establishes communication between outlet efiluent tube 66 and connecting and

outlet tubes

54 and 52 of bags 48. The exact pathways of communication through rotary seal 62 between

tubes

64 and 66 and between

tubes

54 and 66 are not within the purview of the present invention and are within the province of those skilled in the art.

In operation, inlet supply tube 64 is connected to a suitable reservoir, not shown, which contains, for example, a supply of blood mixed with a suitable washing material, said blood mixture being transmitted under pressure through inlet tube 64 and simultaneously through connecting tubes 56 into bags 48 while rotor 58 is spinning. Alternatively, whole blood is initially introduced through tube 64 and tubes 56 into bags 48, after which washing fluid is introduced through

tubes

64 and 56 to wash the cells within bags 48, said cells remaining within said bags while the less dense washing liquid effluents and blood serum emerges from bags 48 through connecting tubes 54 and thence through outlet tube 66 into a suitable receiver, not shown. After the biological cells or blood cells have been adequately washed as may be determined empirically by the nature of the effluents received from outlet tube 66 or by other suitable means, the centrifuging process is terminated,

after which bags 48 and their respective paired shells l1 and 12 are removed from cups 57. Shells l1 and 12 are readily separated to free bag 48 which is then cut open or otherwise emptied and the washed cells are transferred to a suitable container for further clinical or biological analysis and research study.

It is understood that the shape of the unitary cylindrical cavity formed by the juxtaposed shells 11 and 12 will conform substantially to the shape of the flexible bag located therein so that when said bag is filled with materials being centrifuged, it will substantially fill said unitary cavity and, at the same time, will be prevented from expanding more than any desired amount by virtue of its confinement within said shells.

By providing

ribs

21, 22, 41, 42, 26, 27, 43 and 44, in the respective bottom and top locations of shells 11 and 12, the weight of said shells is reduced to a minimum without sacrifice of structural strength when undergoing the stresses of centrifugation.

Although the present invention has been described with reference to particular embodiments and examples, it will be apparent to those skilled in the art that variations and modifications can be substituted therefor without departing from the principles and true spirit of the invention. The Abstract" given above is for the convenience of technical searchers and is not to be used for interpreting the scope of the invention or claims.

We claim:

1. A centrifuge apparatus comprising a rotor, a plurality of separate spaced cups in said rotor, a collapsible cylindrical bag for each of said cups, a pair of shells for each of said bags, a semi-cylindrical cavity in each of said shells, said shells when juxtaposed forming a unitary cylindrical cavity within which a respective bag tits and is entirely confined, the assembly of said pair of shells and said bag being removably inserted longitudinally into a corresponding rotor cup, the seam between said shells being arrayed substantially parallel to the longitudinal axis of said cup,

2. Apparatus according to claim 1 and further comprising means integrally formed on said pair of shells at the top and bottom of said cavities for confining the respective top and bottom of said bag.

3. Apparatus according to claim 1 and further comprising inlet means and outlet means at the top of said bag and corresponding mating recesses in each of said shells through which said respective inlet means and outlet means extend.

4. Apparatus according to claim 1 wherein the juxtaposition of said shells forms a diametrical seam, said scam being arrayed radially in said cup relative to the axial center of the retor.

5. Apparatus according to claim 1 and further comprising cooperating means on each of said cups registering with each other to locate said cups in relation to each other to form a smooth, unitary symmetrical cylindrical cavity therebetween 6. Apparatus according to claim 1 wherein the bottom of each shell has a semi-conical shape bounding the semi-cylindrical cavity, and further comprising integrally formed ribs extending downwardly from each shell, the bottom surfaces of said ribs conforming substantially to the bottom of the rotor cup.

7. Apparatus according to claim 6 wherein said ribs are radially arrayed and form a star-shaped support for said juxtaposed shells within said rotor cup.

8. Apparatus according to claim 1 and further comprising a longitudinally arrayed flat on the outer surface of each shell intermediate the longitudinal edges thereof, said fiat permitting venting of air when the assembly of said shells is moved into and out of the respective rotor cup.

9. Apparatus according to claim 1 and further comprising inlet means and outlet means at the top of said bag, and first and second mating recesses in each of said shells through which said inlet means and outlet means, respectively, extend, said outlet means and said second mating recesses being located in the axial center of said respective bag and of said mated shells, and said first mating recesses and said bag inlet means being located off-center from said outlet means.

10. Apparatus according to claim 9 wherein said inlet means and said first mating recesses are spaced further apart from the axial center of said rotor than said outlet means and said second mating recesses.

. Apparatus according to claim 1 and further comprising spaced apart inlet means and outlet means at the top of said bag and corresponding mating recesses in each of said shells through which said respective inlet means and outlet-means extend, said inlet means being located radially further than said outlet means from the axial center of said rotor, said inlet means extending into the interior of said bag and terminating at a position below said outlet means in said bag and radially a greater distance from the axial center of said rotor than said outlet means.

Claims

1. A centrifuge apparatus comprising a rotor, a plurality of separate spaced cups in said rotor, a collapsible cylindrical bag for each of said cups, a pair of shells for each of said bags, a semi-cylindrical cavity in each of said shells, said shells when juxtaposed forming a unitary cylindrical cavity within which a respective bag fits and is entirely confined, the assembly of said pair of shells and said bag being removably inserted longitudinally into a corresponding rotor cup, the seam between said shells being arrayed substantially parallel to the longitudinal axis of said cup.

4. Apparatus according to claim 1 wherein the juxtaposition of said shells forms a diametrical seam, said seam being arrayed radially in said cup relative to the axial center of the rotor.

5. Apparatus according to claim 1 and further comprising cooperating means on each of said cups registering with each other to locate said cups in relation to each other to form a smooth, unitary symMetrical cylindrical cavity therebetween.

6. Apparatus according to claim 1 wherein the bottom of each shell has a semi-conical shape bounding the semi-cylindrical cavity, and further comprising integrally formed ribs extending downwardly from each shell, the bottom surfaces of said ribs conforming substantially to the bottom of the rotor cup.

8. Apparatus according to claim 1 and further comprising a longitudinally arrayed flat on the outer surface of each shell intermediate the longitudinal edges thereof, said flat permitting venting of air when the assembly of said shells is moved into and out of the respective rotor cup.

11. Apparatus according to claim 1 and further comprising spaced apart inlet means and outlet means at the top of said bag and corresponding mating recesses in each of said shells through which said respective inlet means and outlet means extend, said inlet means being located radially further than said outlet means from the axial center of said rotor, said inlet means extending into the interior of said bag and terminating at a position below said outlet means in said bag and radially a greater distance from the axial center of said rotor than said outlet means.