Blood cell separator

A centrifugal blood component separator with a spiral helically inclined rotor chamber. The apparatus uses continuous blood flow-through without rotating seals. At the lower end of the helical rotor chamber there are terminals for blood input and packed red blood cell output, whereas at the higher end there is a terminal for plasma. Intermediate outlet terminals may be provided for white blood cells and platelets.

FIELD OF THE INVENTION 
This invention relates to centrifuge devices, and more particularly to a 
centrifuge apparatus for separating the components of blood. 
BACKGROUND OF THE INVENTION 
In the prior art many centrifuge devices have been proposed for the 
separation of the various fractional components of blood. Usually these 
devices involve the utilization purely of centrifugal force acting on the 
different-mass components of blood samples. In some cases there is 
flow-through, employing rotating seals. However, there have been 
flow-through centrifuge devices without rotating seals. Such a device has 
been recently described for on-line plasmapheresis of whole blood, in Y. 
Ito, J. Suaudeau, and R. L. Bowman, Science, 189, 999, 1975. 
The prior art devices are either relatively slow-acting, cause some damage 
to the harvested blood components, have limited capacity, or require the 
use of anticoagulants. 
The following is a list of prior art U.S. patents pertinent to the present 
invention, found in a preliminary search: 
Williams, U.S. Pat. No. 3,908,893 
Westberg, U.S. Pat. No. 3,817,449 
Unger, et al, U.S. Pat. No. 3,858,796 
Sartory, et al, U.S. Pat. No. 3,957,197 
Schlutz, U.S. Pat. No. 3,982,691 
Jones, et al, U.S. Pat. No. 4,007,871 
Kellogg, U.S. Pat. No. 4,010,894 
Judson, et al, U.S. Pat. No. 3,655,123 
Adams, U.S. Pat. No. 3,586,413 
Ito, et al, U.S. Pat. No. 3,775,309 
SUMMARY OF THE INVENTION 
The general aim of the present invention is to provide for the simple and 
very rapid collection of red blood cells, white blood cells or platelets, 
or plasma, wherein this collection can be made independently of the other 
blood components, for example, wherein only platelets can be harvested, or 
only plasma can be harvested, or, if so desired, all blood components can 
be harvested at the same time in separate containers. 
Accordingly, a main object of the present invention is to provide a blood 
components separator which is free of the deficiencies of the prior art 
devices heretofore proposed or employed. 
A further object of the invention is to provide an improved simple and 
rapid means for the collection of the components of blood. 
A still further object of the invention is to provide an improved 
flow-through blood centrifuge device which does not employ rotating seals. 
A still further object of the invention is to provide an improved 
centrifuge apparatus for individually harvesting blood components, wherein 
the components are handled gently without damage, and wherein the 
apparatus has a relatively large capacity. 
A still further object of the invention is to provide an improved 
flow-through device for the selective collection of red blood cells, white 
blood cells or platelets, or plasma, wherein the collection of the 
individual components may be independently made, and wherein, if desired, 
all the blood components can be harvested at the same time in separate 
containers. 
Another object is to broadly provide for the improved separation of fragile 
multi-phase systems, such as blood, into separate components. 
A still further object of the invention is to provide an improved device 
for the separation and collection of blood components, said device 
employing the combination of centrifugal force and gravity to separate out 
the various components with a high degree of resolution. 
A still further object of the invention is to provide an improved 
centrifugal blood component separator with a spiral helically inclined 
rotor chamber, using continuous blood flow-through without rotating seals, 
wherein terminals are provided for blood input, red blood cell output, and 
output of other blood components, and wherein selective collection of the 
blood components may be accomplished, the separator causing minimum damage 
to the blood components and having a high capacity. 
The foregoing objects, as well as others, are achieved in accordance with 
the present invention by providing a separation chamber in the form of a 
helical spiral channel, with terminals for the blood inlet and packed red 
blood corpuscle outlet, and for plasma, white blood corpuscles and/or 
platelet outlets. Blood cells sediment in a radially acting centrifugal 
field. In this spiral configuration, blood flows "uphill" against a "g" 
force gradient which forces heavier cells to travel in opposite direction 
to plasma and lighter cells (countercurrent flow), each fraction being 
continuously harvested through its respective terminal.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring to the drawings, FIGS. 1, 2 and 3 show a typical horizontal rotor 
assembly for the centrifugal separation of blood components. Said assembly 
comprises a horizontal centrifuge bowl 11 of circular shape having an 
annular concentric inner wall 12 spaced from the outer wall of the bowl 
and defining therewith an annular compartment 13. The bowl is provided 
with a generally circular top cover 14. The bowl 11 may be made of 
aluminum and the top cover 14 may be made of acrylic plastic material. The 
bottom wall of the bowl is provided with a central aperture 15 and the top 
cover is provided with a similar central aperture 16. The apertures 15 and 
16 enable the bowl assembly to be secured on a vertical driving sleeve 17 
forming part of a driving system without rotating seals, as shown 
diagrammatically in FIG. 8, presently to be described. 
Concentrically mounted horizontally in the compartment 13 is a generally 
circular separation chamber 18 which may comprise a hollow ring-like 
member of rectangular cross-section suitably supported concentrically in 
compartment 13, for example, by a plurality of spaced radial brackets 19. 
A typical chamber 18 has a cross-section 3.5 cm high and 0.45 cm wide, has 
a length of 100 cm and a total prime volume of 180 ml. 
At one end the chamber 18 is provided with a generally rectangular, 
radially extending, terminal enlargement 20 which is used as a component 
outlet collection enclosure. Thus, the inner end of the outlet terminal 
enclosure 20 is connected to a flexible plasma collection line 21 and the 
outer end of the enclosure 20 is connected to red blood cell flexible 
collection line 22. A blood inlet connection is made to the opposite end 
of chamber 18 by a flexible tube, shown at 23. 
As shown in FIG. 3, the red blood cell connection to line 22 is made at the 
bottom of terminal enclosure 20, whereas the plasma connection to line 21 
is made at the top portion of enclosure 20. 
In operation, when bowl 11 rotates at operating speed, with blood flowing 
into the chamber 18 through the inlet line 23, centrifugal force tends to 
separate the red blood cells from the plasma and the gravitational field 
acts on the red blood cells, tending to cause them to descend to the 
bottom portion of the chamber 18, whereas the plasma collects in the upper 
portion thereof. The red blood cells are drawn off through the collection 
line 22 and are delivered to their intended destination, whereas the 
plasma is drawn off and delivered via the collection line 21. 
Significantly improved operation is obtained by arranging the separation 
chamber in a spiral helical configuration, as shown in FIGS. 4, 5 and 6. 
In this arrangement, the separation chamber, shown at 18', is in spiral 
helical form and has an enlarged generally rectangular, inwardly radially 
extending terminal enclosure 30 at its lower end and a generally 
rectangular, inwardly extending terminal enclosure 31 at its higher end. 
In the spiral configuration shown in FIG. 4, the higher end terminal 
enclosure 31 is located inwardly relative to the lower end terminal 
enclosure 30, with respect to the vertical central axis of the chamber 
18'. 
The blood inlet line, shown at 23', is connected to the upper end of 
terminal enclosure 30. The red blood cell outlet line, shown at 22', is 
connected to the lower end of terminal enclosure 30. The plasma outlet 
line, shown at 21', is connected to the higher end terminal enclosure 31. 
A white blood cell/platelet collection line 32 may be connected to a 
suitable intermediate portion of the collection chamber 18'. 
This provides terminals for the blood inlet flow and for the packed red 
blood cells, plasma and white blood cell/platelet flow. In the typical 
separation chamber above described, in operation blood cells sediment in a 
radially acting centrifugal field along a distance of 0.45 cm. In this 
spiral configuration, blood flows "uphill" against a "g" force gradient 
which forces heavier cells to travel in an opposite direction to plasma 
and lighter cells (countercurrent flow), each fraction being continuously 
harvested through its respective terminal. 
In tests made on a typical design substantially according to FIGS. 4, 5 and 
6, the device was tested at up to 400 ml/min blood flow rate. The 
experiments showed highly efficient separations of plasma, platelets and 
lymphocytes from the whole blood. 
FIG. 7 shows an embodiment providing more positive separation for white 
blood cells and platelet collection. In this embodiment, the collection 
chamber, shown at 33, has the same spiral helical configuration as in 
FIGS. 4, 5 and 6, but is provided at an intermediate location therein with 
an upstanding transverse rib or projection 34 and thereabove with a spaced 
conformably shaped top wall portion 35 to define an overflow channel 36 
for plasma and white blood cells and platelets. Thus, in operation, the 
white blood cells and platelets settle in the corner portion defined by 
transverse rib 34 and the adjacent upper section of chamber 33, as shown 
at 37, for collection through outlet line 32. 
The above-described system handles the blood components in an extremely 
gentle manner for individual harvesting. In this system, the blood may be 
exposed (in a countercurrent manner) to highly blood-compatible polymers, 
resulting in unusually low damage to blood cellular components. The 
capacity of the apparatus is relatively large, and in a typical embodiment 
it was possible to separate blood components at a flow rate as high as one 
unit of whole blood per minute. It is thus possible to withdraw from a 
donor, for example, only red blood cells (for red blood cell transfusion), 
or for example, only platelets (for platelet transfusion). The apparatus 
makes it possible to continuously harvest and concentrate platelets 
without damage for immediate use by a patient, with reduced need for the 
use of anticoagulants. 
The separation chamber may be constructed of any suitable material having 
appropriate physical and chemical properties, and may comprise a plurality 
of helical turns, if so desired. For example, said separation chamber may 
be constructed of fabric-reinforced silicone rubber membrane and may 
comprise two complete helical turns. Also, the chamber may be made with a 
relatively large cross-sectional area 60 at its lower region (where 
deposit of red blood cells occurs) and with a more constricted 
cross-sectional area 61 through its remaining upper portion, as shown for 
example in FIG. 9. 
FIG. 8 schematically illustrates a typical system for driving a centrifugal 
bowl assembly, as above described, without rotating seals. The bowl 11 is 
rigidly connected concentrically to a vertical sleeve 17 rotatably mounted 
on a frame 40, which in turn is secured on the vertical shaft 41 of a 
stationary electric motor 42. A vertical countershaft 43 is rotatably 
supported on frame 40 and is gearingly coupled to sleeve 17 by 1:1 gearing 
44,45. At its lower end, countershaft 43 is gearingly coupled to a 
stationary gear 46 on motor 42 in a 1:1 ratio by a planet gear 47 and a 
toothed drive belt 48. Countershaft 43 is gearingly coupled with a 1:1 
ratio to a vertical sleeve 49 rotatably supported on frame 40, by a gear 
50 on shaft 43, a gear 51 on sleeve 49, and a toothed drive belt 52 
gearingly engaging said gears 50,51. 
The connection conduits, for example, 21, 22, 23, are designated as a 
bundle 53, and pass through sleeves 17 and 49 in the manner shown 
schematically in FIG. 8, and then pass through an aperture 54 in a 
stationary top wall 55 en route to their various destinations. 
In operation, the drive shaft 41 of the motor 42 drives the frame 40 at a 
particular selected angular velocity .omega., (for example, at 500 RPM). 
The gear 7 which is fixed to the countershaft 43 rotates about the axis of 
rotation of the drive shaft 41. Also, because of its connection, via the 
toothed belt 48, to the fixed gear 46, this causes the countershaft 43 to 
rotate relative to frame 40. As a result, gear 44 drives gear 45 at an 
angular velocity of 2.omega. because of the 1:1 gear ratio. As a further 
result, the bowl 11, fixed to hollow shaft 17, rotates at an angular 
velocity of 2.omega. (1000 RPM). 
At the same time, the gear 50, rotating with the countershaft 43, drives 
the toothed belt 52, which in turn drives the gear 51 fixed to the hollow 
shaft 49. This causes hollow shaft 49 to rotate about its own axis at an 
angular velocity of -.omega.. As a consequence of this, the bundle 53 of 
the flexible tubes 21, 22, 23 does not become twisted and yet allows fluid 
communication into and out from the centrifuge chamber in bowl 11 without 
the presence of any rotating seals. 
FIGS. 10 and 11 show, in developed form, additional spiral helical 
separation chambers according to the present invention, generally similar 
to that of FIGS. 4 to 6 but with blood inlets, shown respectively at 68 
and 78, located at points spaced upwardly from the red blood cell outlets 
22. In FIG. 10, the separation chamber, designated generally at 61, has 
its blood inlet 68 located a short distance upwardly from the red blood 
cell outlet at the lower end of the chamber, thus maintaining an "uphill" 
separation between the blood inlet 68 and the red blood cell outlet 22'. 
FIG. 11 is similar, but in this embodiment the blood inlet 78 is located a 
longer distance upwardly along the separation chamber, designated at 61'. 
As in FIG. 10, there is a substantial "uphill" separation of the blood 
inlet 78 from the red blood cell outlet 22' at the lower end of the 
chamber. 
FIGS. 12 to 14 show a further embodiment of the present invention wherein 
the ring-like rotor chamber, shown at 80, is of generally conical spiral 
helical form, and may be mounted in a hollow conical "bowl" member 81 
rotating around its vertical axis. As will be seen from FIG. 12, the 
cross-section of the separation chamber is tilted at an angle to the 
direction of the shaft of the centrifuge, namely, at the slope angle of 
the associated generating cone, thus providing another plane of 
separation, yielding a second stage of "uphill travel" in addition to the 
basic one along the length of the chamber, as previously described, 
wherein the blood flows "uphill" against a "g" force gradient which forces 
heavier cells to travel in an opposite direction to plasma and lighter 
cells. 
It is to be noted that along with separation of other blood components, the 
apparatus of the present invention can be utilized for the separation of 
white blood cells into fractional components, including granulocytes, 
lymphocytes, and other fractions of the white blood cell population. 
A particular advantage of the present invention, besides its capacity to 
more effectively separate various components of the blood in a more 
effective manner and with less damage to such components, is its ability 
to function effectively without, or with reduced quantities of, 
anticoagulants. 
While specific embodiments of an improved flow-through blood centrifuge 
system and rotor chambers employed therein have been disclosed in the 
foregoing description, it will be understood that various modifications 
within the scope of the invention may occur to those skilled in the art. 
Therefore it is intended that adaptations and modifications should and are 
intended to be comprehended within the meaning and range of equivalents of 
the disclosed embodiments.