CN115297939A - Centrifuge system for separating cells in suspension - Google Patents

Abstract

An apparatus for separating cell suspension material into centrate and concentrate includes a single-use structure (178, 240, 250, 370, 414) releasably positioned in a cavity in a solid wall rotatable centrifuge bowl (172). The drum and portions of the single-use construction rotate about an axis (174, 428). The stationary inlet feed tube (184, 430), centrate discharge tube (212, 436), and concentrate discharge tube (230, 448) extend along an axis of the rotating single-use configuration. A centrate centripetal pump (208, 438) is fluidly connected to the centrate discharge tube. The concentrate centripetal pump (216, 450) is fluidly connected to the concentrate discharge tube. The at least one concentrate channel (380, 454) and the concentrate centripetal chamber (376, 452) are configured to facilitate flow of the cell concentrate.

Description

Centrifuge system for separating cells in suspension

Technical Field

The present disclosure relates to centrifugation of materials. An exemplary arrangement relates to a device for separating cells in a suspension by centrifugation.

Background

Devices and methods for centrifuging cells in suspension are useful in a number of technical environments. Such apparatus and methods may benefit from improvements.

Disclosure of Invention

Exemplary arrangements described herein include apparatus and methods for centrifuging cells in large scale cell cultures having high cell concentrations using pre-sterilized, single-use fluid path components. The exemplary centrifuges discussed herein may be solid wall centrifuges using pre-sterilized, single-use components, and may be capable of processing cell suspensions having high cell concentrations.

An exemplary arrangement uses rotationally fixed feed and discharge members. Single-use components typically include a flexible membrane mounted on a rigid frame that includes a core having an enlarged diameter. The single-use component may further comprise at least one centripetal pump. The single-use structure may be supported within a multi-use rigid drum having an internal truncated cone shape. These configurations allow the exemplary system to maintain a sufficiently high angular velocity to produce a settling velocity suitable for efficiently processing highly concentrated cell culture streams. The feature of minimizing feed turbidity, and other features that allow continuous or semi-continuous discharge of cell concentrate, provides an increase in overall productivity over achievable rates. The exemplary structures and methods provide efficient operation and reduce the risk of contamination.

Drawings

FIG. 1 is a schematic diagram of an exemplary arrangement of a centrifuge system including single-use and multi-use components.

FIG. 2 is a close-up view of the upper flange region of the centrifuge of FIG. 1 illustrating a method of sealing the flexible chamber material to the surface of the flange.

Fig. 3 is an isometric cross-sectional view of the core and upper flange of the single-use component of the arrangement of the centrifuge system of fig. 1.

FIG. 4 is a schematic view of the arrangement shown in FIG. 1, wherein the pump chamber of the centrifuge system includes an accelerator vane.

FIG. 5 is an isometric view of the top of a pump chamber of the example arrangement of the centrifuge system shown in FIG. 4.

FIG. 6 is an isometric cross-sectional view of a core, upper flange and lower flange of a single-use centrifuge system with an enlarged core diameter (to create a shallow pool centrifuge) and a feed accelerator.

Fig. 7 is an isometric view of the feed accelerator of fig. 6.

FIG. 8 is an isometric cross-sectional view of a core and upper flange of a single-use centrifuge system having a standard core diameter and a feed accelerator with curved blades and an elliptical bowl.

Fig. 9 is an isometric view of the feed accelerator of fig. 8.

FIG. 10 is a schematic diagram of a portion of a continuous concentrate discharge centrifuge system.

FIG. 11 is a schematic view of a portion of another arrangement including a continuous concentrate discharge centrifuge system.

Fig. 12 is a schematic diagram of a continuous concentrate discharge centrifuge system with diluent injection.

FIG. 13 is a schematic diagram of a portion of yet another example arrangement of a continuous concentrate discharge system having a throttle mechanism for a centripetal pump.

FIG. 14 is an isometric cross-sectional view of a core and upper flange of a single-use centrifuge system having a core and a feed accelerator with straight blades.

Fig. 15 is an isometric view of the feed accelerator of fig. 14.

Fig. 16 is an isometric cross-sectional view of an alternative continuous concentrate discharge centrifuge system.

Fig. 17 is an isometric exploded view of an alternative centripetal pump.

FIG. 18 is an isometric view of a plate of an alternative centripetal pump including a volute channel therein.

FIG. 19 is a schematic diagram of a centrifuge system operating to ensure positive pressure is maintained in the centrifuge core chamber.

FIG. 20 is a schematic diagram illustrating a simplified exemplary logic flow executed by at least one control circuit of the system shown in FIG. 19.

Fig. 21 is a schematic cross-sectional view of an alternative continuous centrifuge filter and concentrate discharge centrifuge system.

FIG. 22 is a schematic cross-sectional view of another alternative continuous centrate and concentrate discharge centrifuge system.

FIG. 23 is a schematic cross-sectional view of another alternative continuous centrate and concentrate discharge centrifuge system.

FIG. 24 is a schematic diagram of a control system for an exemplary continuous centrate and concentrate discharge centrifuge system.

FIG. 25 is a schematic representation of a logic flow associated with the exemplary control system of FIG. 24.

Fig. 26 is a cross-sectional view of an exemplary upper portion of a single-use centrifuge structure including a concentrate dam and a centrate dam located in the separation chamber.

FIG. 27 is a cross-sectional view of an exemplary upper portion of a single-use configuration that includes vanes in the centrifuge pump chamber and the concentrate pump chamber to control the radial position of the air/liquid interface.

FIG. 28 is a perspective view of a chamber surface of an exemplary concentrate or centrate pump chamber, the chamber surface including a plurality of chamber vanes.

Fig. 29 is an axial cross-sectional view of an exemplary upper portion of a single-use configuration similar to that shown in fig. 27, illustrating the location of the air/liquid interface.

Fig. 30 is an axial cross-sectional view of an exemplary upper portion of a single-use configuration that includes an air channel for retaining pressurized air in an air pocket.

FIG. 31 is a schematic diagram of an exemplary system for controlling a centrifuge system including centrate return pressure control.

FIG. 32 is an axial schematic cross-sectional view of yet another alternative continuous centrate and concentrate discharge centrifuge system.

Fig. 33 is a cross-sectional view of the upper portion of the system shown in fig. 32.

Fig. 34 is a schematic cross-sectional view similar to fig. 32, but with the system in operation and with an annular cell concentrate region in the separation chamber.

FIG. 35 is an external front top perspective view of yet another alternative single-use centrifuge structure.

Figure 36 is a cross-sectional view of the single use configuration shown in figure 35.

Figure 37 is an exploded view of the upper disk-shaped portion of the single use configuration shown in figure 35.

FIG. 38 is a perspective view of the lower part of the upper disc-shaped portion of the structure shown in FIG. 35.

Detailed Description

In the field of cell culture for biopharmaceutical processes, there is a need to separate cells from a fluid medium, such as a fluid in which the cells are grown. The desired product from the cell culture may be a molecular species secreted into the medium by the cell, a molecular species retained within the cell, or it may be the cell itself. On a production scale, the initial phase of the cell culture process is typically carried out in a bioreactor, which may be operated in a batch mode or a continuous mode. Variations, such as repeated batch processes, may also be implemented. The desired product must often be finally separated from other process components prior to final purification and product formulation. Cell harvesting is a general term applied to the separation of these cells from other process components. Clarification is a term referring to cell separation, wherein the target is a cell-free supernatant (or centrate). Cell recovery is a term commonly applied to separations targeting cell concentrates. The exemplary arrangements herein relate to cell harvest and isolation in large scale cell culture systems.

Methods for cell harvest separation include batch, continuous and semi-continuous centrifugation, tangential Flow Filtration (TFF) and depth filtration. Historically, centrifuges used to harvest cells of large cell cultures on a production scale are complex multi-use systems that require Cleaning In Place (CIP) and Steam In Place (SIP) technology to provide a sterile environment to prevent contamination by microorganisms. In laboratory scale and continuous cell harvesting processes, smaller systems can be used. Manufactured by the Pneumatic Scale Corporation is described in published application US2010/0167388

Centrifuge systems, the entire disclosure of which is incorporated herein by reference, successfully process culture batches for cell harvest using batch processing in amounts ranging from 3-30 liters per minute up to about 2000 liters. Also incorporated herein in their entirety are U.S. Pat. No. 10,384,216 and U.S. Pat. No. 9,222,067, also owned by the assignee of the present application, pneumatic Scale Corporation. Batch processing typically requires periodic stopping of the centrifuge bowl rotation and feed flow in order to discharge the concentrate. This method generally works well in lower concentration, high viability cultures where large batches can be processed and the cell concentrate is discharged relatively quickly and completely.

It is sometimes desirable to harvest cells from a high concentration and/or low viability cell culture that contains a high concentration of cells and cell debris in a material feed, sometimes referred to as a "high turbidity feed". In some centrifugal separation systems, this high turbidity feed slows the process rate because:

1. a slower feed flow rate is required to provide increased residence time in the centrifuge for separation of small cell debris particles, and

2. higher concentrations of cells and cell debris can cause the drum to fill with cell concentrate quickly, requiring the drum to stop to discharge the concentrate.

These combined factors may lead to a reduction in net productivity and unacceptably long cell harvest processing times. In addition to the increased costs that may be associated with longer processing times, the increased time in the centrifuge may also result in higher levels of product contamination and loss when harvesting low viability cell cultures.

High concentrations of cells and cell debris in the material feed may also result in cell concentrates with very high viscosities. This may make it more difficult to completely discharge the cell concentrate from the centrifuge, even under extended discharge cycles. In some cases, additional buffered rinse cycles may be added to obtain a sufficiently complete discharge of the concentrate. The need to make either or both of these adjustments to the drain cycle further increases processing time, which can make the challenge of processing large volumes of cell culture more complex and expensive.

Scaling up the size of the system by increasing the drum size to increase the length of the feed portion of the batch processing cycle is sometimes impractical because it also results in a proportionally longer discharge cycle for the cell concentrate. Another limitation that may prevent simple geometric scaling is scaling of the relevant fluid dynamics factors. The maximum processing rate of any centrifuge depends on the settling velocity of the separated particles. The settling velocity is given by a modification of the stokes law defined by equation 1:

where v = sedimentation velocity, Δ ρ is the solid-liquid density difference, d is the particle diameter, r is the radial position of the particle, ω is the angular velocity, μ is the liquid viscosity. With respect to the scaled-up geometry, changing the radius of the drum changes the maximum radial position r that the particles can occupy. Thus, if the other parameters in equation 1 are held constant, an increase in drum radius results in an increase in the average settling velocity and an increase in throughput for a given separation efficiency. However, as the radius increases, maintaining the angular velocity of the drum becomes more difficult due to increased material strength that may be required and other engineering constraints. If the decrease in angular velocity is greater than the square root of the proportional increase in radius, the gains in average settling velocity and throughput (which is proportional to radius) both decrease.

One engineering limitation that must be considered is that the angular velocity required to rotate a larger bowl may not be practical to achieve due to the need for a larger mass and more expensive centrifuge drive platform.

In addition, if the angular velocity remains constant as the radius increases, the force pushing the cells towards the wall of the centrifuge also increases. When the drum is rotated at a sufficiently high angular velocity to produce the desired treatment efficiency, both the walls of the vessel and the cells accumulated therein are subjected to increased stress. For cells, this can cause cell damage by encapsulating the cells to too high a concentration. Cell damage is a disadvantage in applications where cell viability needs to be maintained, and can lead to contamination of the product in solution present in the centrate. The higher viscosity resulting from too high a cell concentration is sometimes also a disadvantage of complete discharge of the cell concentrate.

Exemplary arrangements include apparatus and methods for continuous or semi-continuous centrifugation of low viability cell suspension cultures containing high concentrations of cells and cell debris at rates suitable for processing large volumes of cell suspensions on a commercial scale. Some exemplary centrifuges have a pre-sterilized, single-use design and are capable of processing such cell suspensions at flow rates in excess of 20 liters/minute. For a 2000 liter bioreactor, this flow capacity results in a total run time in the range of 2 to 3 hours. An exemplary arrangement of a single-use centrifuge system may be capable of processing approximately 300 to 2000 liters of fluid while operating at a rate of approximately 2 to 40 liters per minute.

Fig. 1 discloses a single-use centrifuge structure 1000. The centrifuge structure 1000 includes a core structure 1500 (best shown in fig. 3) that includes a core 1510, an upper flange 1300, a lower flange 1200, and a flexible liner 1100 sealed to both the upper flange 1300 and the lower flange 1200. The centrifuge structure 1000 further includes a centripetal pump 1400 comprising a pair of stationary scraping discs 1410 and a rotating mechanical seal 1700 in a rotating pump chamber 1420.

Centrifuge structure 1000 further includes an infeed/outfeed assembly 2000. The assembly 2000 includes a plurality of concentric tubes about a rotational axis 1525 (labeled in fig. 12) of the centrifuge 1000. The innermost portion of infeed/outfeed assembly 2000 includes an infeed tube 2100. A plurality of additional tubes concentrically surround the feed tube 2100 and may include a tube or fluid passageway 2200 that allows centrate to drain, a tube or fluid passageway 2500 that allows concentrate to drain (see, e.g., fig. 12), or a tube or fluid passageway 5000 that allows diluent to be supplied (see, e.g., fig. 12). Each portion of the feed/discharge connection may be fluidly connected to a portion of the interior of centrifuge 1000 via an appropriate fluid connection, as well as to a collection or feed chamber (not shown), and may include additional tubes fluidly connected to the concentric tubes to remove centrate, concentrate, or diluent from or add it to the system.

As shown in fig. 1, upper flange 1300 and lower flange 1200 comprise conical drums that are axially aligned with and recessed toward core 1510. The core 1510 comprises a generally cylindrical body having a hollow cylindrical center that is large enough to receive a feed tube 2100 having an axis 1525 (labeled in fig. 12). The upper flange 1300, core 1510, and lower flange 1200 may be a unitary structure to provide a stronger support structure for the flexible liner 1100, which is also referred to herein as a membrane. In other arrangements, the core structure 1500 may be formed from multiple component parts. In further arrangements, the core 1510 and the upper flange 1300 may comprise a single piece, with the lower flange 1200 comprising a separate piece, or the core 1510 and the lower flange 1200 may comprise a single piece, with the upper flange 1300 comprising a separate piece.

Fig. 3 shows an exemplary unitary core 1510 and upper flange 1300 arrangement. This integral component will be joined to the lower flange 1200 to create the internal support structure 1500 of the single use component of the centrifuge 1000. This structure anchors the flexible liner 1100 at the top and bottom around a fixed internal rigid or semi-rigid support structure 1500. When the centrifuge system is in use, the flexible liner 1100 is also externally supported by the walls and lid of the bowl of the multi-use structure 3000.

The exemplary separation chamber 1550 is an open chamber that is generally cylindrical in shape, generally bounded by the outer surface 1515 of the core 1510 and the flexible liner 1100, and by the upper surface 1210 of the lower flange 1200 and the lower surface 1310 of the upper flange 1300. The separation chamber 1550 is fluidly connected to the feed tube 2100 via an aperture 1530 extending from the central cavity 1520 of the core 1510 to the outer surface 1515 of the core 1510. The separation chamber 1550 is also fluidly connected to the pump chamber 1420 via a similar aperture 1540 through the core structure 1500. In this example, the bore 1540 slopes upward, toward the pump chamber 1420, opening into the separation chamber 1550 directly below the junction between the core 1510 and the upper flange 1300. As shown in fig. 12, apertures 1420 or 4420 may enter the pumping chamber at angles other than upward, including horizontally or at a downward angle. Additionally, in some arrangements, the holes 1420, 4420 may be replaced by slits or gaps between accelerator vanes.

Fig. 1 also shows a feed/discharge assembly 2000 that includes a feed tube carrier 2300 by which a feed tube 2100 extends to the position shown in fig. 3, near the bottom of the centrifuge structure 1000. In this position, the feed tube 2100 can perform both feed and discharge functions without movement. By careful design of the gap between the nozzle 2110 of the feed tube 2100 and the upper surface 1210 of the lower flange 1200, the diameter of the nozzle 2110 of the feed tube 2100, and the angular velocity of the centrifuge, shear forces during the feeding process can be minimized. U.S. patent No. 6,616,590, the disclosure of which is incorporated herein by reference in its entirety, describes how to select an appropriate relationship to minimize shear forces. Other suitable feed tube designs known to those skilled in the art that minimize shear forces associated with feeding a liquid cell culture into a rotary centrifuge may also be used.

Fig. 1 also includes a centripetal pump 1400 for discharging centrate through a centrate discharge passage 2200. In the arrangement shown in fig. 1, centrate pump 1400 is located above the upper flange 1300 in pump chamber 1420. The pump chamber 1420 is a chamber defined by the upper surface 1505 of the core 1510 and the inner surfaces 1605, 1620 of the centrifuge cover 1600. Centrifuge cover 1600 may include a cylindrical wall 1640 and a mating cover portion 1610 shaped like a generally circular disk (shown in fig. 5). The centrifuge cover 1600 may be formed as a single piece or from separate components.

As discussed in more detail below, the shape and position of the centrate pump chamber 1420 may vary in other arrangements. Chamber 1420 will typically be an axisymmetric chamber near the upper end of core structure 1500 that is fluidly connected to separation chamber 1550 via an aperture or slit 1530 that extends from near the exterior of core 1515 into centrate pump chamber 1420. In some arrangements, as best shown in fig. 11 and 12, the centrate pump chamber 1420 may be located in a recess within the chamber 1550.

Exemplary centrate pump 1400 includes a pair of scraping discs 1410. The scraping disk 1410 is two thin disks (plates) that are axially aligned with the axis 1525 of the core structure 1500. In the arrangement shown in fig. 1-5, the paring discs 1410 are held stationary relative to the centrifuge structure 1000 and are separated from each other by a fixed gap 1415 (labeled 1415 in fig. 10). The gaps 1415 between the scraping discs 1410 form part of a fluid connection for removing centrate from the centrifuge 1000, which allows centrate to flow between the scraping discs 1410 into a hollow cylindrical centrate discharge passageway 2200 around the feed tube carrier 2300 that terminates in the centrate outlet 2400.

The exemplary single-use centrifuge structure 1000 is contained within a multiple-use centrifuge structure 3000. Structure 3000 includes a drum 3100 and a cover 3200. The walls of centrifuge bowl 3100 support flexible liner 1100 of centrifuge structure 1000 during rotation of centrifuge 1000. To do so, the exterior structure of the single-use configuration 1000 and the interior structure of the multiple-use configuration are compatible with one another. Similarly, the upper surface of the upper flange 1200, the exterior of the upper portion of the core 1510, and the lower portion of the wall 1640 of the centrifuge cover 1600 conform to the inner surface of the multi-use drum cover 3200, which is also adapted to provide support during rotation. Features of the multi-use drum 3100 and the drum lid 3200 (discussed in more detail below) are designed to ensure that shear forces do not tear the liner 1100 from the single-use centrifuge structure 1000. In some cases, an existing multi-use structure 3000 can be retrofitted for single-use disposal by selecting a conforming single-use structure 1000. In other cases, the multiple-use configuration 3000 may be specifically designed for use with a single-use configuration insert 1000.

Fig. 2 illustrates a portion of an exemplary structure for an upper flange 1300, a plastic liner 1100, and a lid 3200 of a multiple use centrifuge structure 3000 to illustrate the sealing of the flexible liner 1100 to the upper flange 1300. The flexible liner 1100 may be a thermoplastic elastomer such as polyurethane (TPU) or other stretchable, tough, non-tearing, biocompatible polymer, while the upper and lower flanges 1300, 1200 may be made of a rigid polymer such as polyetherimide, polycarbonate, or polysulfone. The flexible liner 1100 is a thin sleeve or envelope that extends between and seals to the upper and lower flanges 1300, 1200 and forms the outer wall of the separation chamber 1550. The composition of the pad 1100 and the upper and lower flanges 1300, 1200 and the core 1510 described herein are exemplary only. Those skilled in the art may substitute suitable materials having properties similar to those suggested that are known or that may become known.

A thermal bond attachment process may be used to bond the different materials in the areas shown in fig. 2. The thermal bond 1110 is formed by preheating the flange material, placing the elastomeric polymer on top of the heated flange, and applying heat and pressure to the elastic film liner 1100 at a temperature above the softening point of the film. The plastic liner 1100 is bonded to the lower flange 1200 in the same manner. Although thermal bond 1110 is described herein, it is merely exemplary. Other means of creating a similarly strong relatively permanent bond between the flexible membrane and the flange material may be substituted, such as by temperature, chemical, adhesive or other bonding means.

Exemplary single-use components are pre-sterilized. During removal of the components from their protective packaging and installation into a centrifuge, the thermal bonds 1110 remain sterile within the single-use chamber. When in use, the stretchable flexible liner 1100 conforms to the walls of the reusable bowl 3100. The reusable bowl 3100 provides sufficient support and the flexible liner 1100 is sufficiently resilient to allow the single use configuration 1000 to withstand the increased rotational forces that arise when a larger radius centrifuge 1000 is filled with liquid cell culture or other cell suspension and rotated at sufficient angular velocity to reach a settling velocity that allows processing at a rate of about 2 to 40 liters per minute.

In addition to thermal bonds 1110, sealing ridges or "nubs" 3210 may be present on the drum cover 3200 to press the thermoplastic elastomer film against the rigid upper flange 1300 to form additional seals. The same compression seal may also be used at the bottom of the drum 3100 to seal the thermoplastic elastomer film to the rigid lower flange 1200. These compression seals support thermal bond area 1110 by isolating it from shear forces created by hydrostatic pressure generated when the chamber is filled with liquid during centrifugation. The combination of thermal bond 1110 and compression nub 3210 seal has been tested at 3000 times gravity (3000 x g), which corresponds to a hydrostatic pressure of 97psi at the drum wall. The pad should be thick and compressible enough to allow the nubs 3210 to compress and grip the flexible pad 1100 while minimizing the risk of tearing near the thermal bond 1110 or the compression nubs 3210. In one example arrangement, a 0.010 inch thick flexible TPU liner is sealed without tearing or leaking.

An arrangement corresponding to the illustrations of fig. 1-2 was tested in a 5.5 inch diameter drum. It has a hydraulic capacity of > 7 liters per minute at 2000 times gravity and successfully separates mammalian cells to 99% efficiency at a rate of 3 liters per minute.

In most cases, the upper flange 1300 and lower flange 1200 can have a shape similar to the shape shown in fig. 1, but in some cases the upper surface of the single use centrifuge structure can have a different shape, as shown in fig. 10 and 11. In the arrangement shown in fig. 10 and 11, rather than having a generally conical drum cover 3200 to accommodate the generally conical upper flange 1300, both the upper flange and the drum cover are relatively disc-shaped. Those skilled in the art will be able to adapt the sealing techniques described herein to sealing surfaces of different shapes.

Fig. 4-5 illustrate example arrangements having features that improve the efficiency of the centripetal pump 1400. As shown in detail in fig. 5, this arrangement for the internal structure of the single-use component similar to that shown in fig. 1 and 2 includes a plurality of radial fins 1630 on the inner surface 1620 of the cap portion 1610 of the pump chamber 1420. Fig. 5 shows the inner surface 1620 of the cap 1610 of the centrifuge cover 1600. The radial tabs 1630 may be thin, generally rectangular radial plates that extend perpendicularly from the inner surface 1620 of the cap 1610. In this exemplary arrangement, six (6) fins 1630 are shown, but other arrangements may include fewer or more fins 1630. In this arrangement, the tabs 1630 form part of the inner surface of the cap 1620, but in other arrangements may include an upper surface 1620 of the pump chamber 1420, which may take a form other than that of the cap 1610. When the centrifuge system 1000 is in use, the vanes 1630 are positioned above the scraping disk 1410 of the centripetal pump 1400 in the chamber 1420. These vanes 1630 transmit the angular rotation of centrifuge 1000 to the centrate within pump chamber 1420.

This increases the efficiency of the centripetal pump 1400, stabilizes the gas-liquid interface in the pump chamber 1420 above the scraping disk 1410, and increases the size of the gas barrier. The gas barrier is a generally cylindrical column of gas extending outwardly from the exterior of the feed/discharge mechanism 2000 into the pump chamber 1420 to the inner surface of the rotating centrate. This increase in barrier size also occurs because the resulting increase in angular velocity of the centrate forces the centrate toward the centrifuge wall. When the rotating centrate contacts the stationary scraper disk 1410 within the pump chamber 1420, the resulting friction may reduce the efficiency of the pump 1400. A plurality of radial vanes 1630 are added that rotate at the same angular velocity as the centrate, overcoming any reduction in velocity that might otherwise result from collisions between the rotating centrate and the stationary scraping disk 1410.

FIG. 6 shows an exemplary arrangement of a core structure 1500 for a high turbidity feed. Core structure 1500 includes a core 1510, an upper flange 1300, and a lower flange 1200. Core 1510 has a cylindrical central cavity 1520 adapted to allow insertion of feed tube 2100 into central cavity 1520. The distance from the central axis 1525 to the outside of the core 1515 (core width, indicated by the dashed line 6000 in fig. 6) is greater than the cloth shown in fig. 3The corresponding distance in center. The larger diameter core 1510 reduces the depth of separation chamber 1550 (represented by dashed line 6010) so that centrifuge 1000 operates as a shallow pool centrifuge. The depth 6010 of the separation chamber 1550 is generally the distance between the exterior of the core 1510 and the flexible liner 1100 labeled in fig. 1 and 12. A shallow pool centrifuge is a centrifuge with a depth 6010 that is small relative to the diameter of the centrifuge. As can be seen in the exemplary arrangement shown in fig. 12, to facilitate removal of cell concentrate, shallow pool depth 6010 may vary from shallower at the bottom of separation chamber 1550 to slightly deeper at the top of separation chamber 1550. In some arrangements shown herein, the ratio of the average separation cell depth 6010 to the core width is 1. One example of a shallow pool centrifuge is that manufactured by pnematic Scale Corporation

Alternative models of centrifuge systems are provided. An advantage of a shallow pool centrifuge is that it enables separation at higher feed flow rates. This is achieved by a higher average gravity for a given inner drum diameter, which results in a higher settling velocity at a given angular velocity. The resulting enhanced separation performance is beneficial when separating highly turbid feeds containing high concentrations of cell debris.

The example arrangement of core structure 1500 shown in fig. 6 also includes accelerator blades 1560 as part of the lower flange 1200. The accelerator blade 1560 (shown in fig. 12) (rather than the aperture 1530 through the solid core 1510 (shown in fig. 10-11)) includes an alternative arrangement of fluid connection between the central cavity 1520 of the core 1510 and the separation chamber 1550.

In the exemplary arrangement of the core structure 1500 shown in fig. 6, the accelerator blades 1560 comprise a plurality of radial, generally rectangular, spaced-apart webs 1580 that extend upward from the upper conical surface of the lower flange 1200. The plates 1580 extend upward perpendicular to the base of the core 1510. The plates 1580 extend generally radially outward from proximate the axis 1525 of the core 1510. In an exemplary arrangement, as best shown in fig. 7, there are 12 plates 1580. In other arrangements, there may be fewer or more than 12 plates 1580. Additionally, in other arrangements, plate 1580 may be curved in the direction of rotation of centrifuge 1000, as shown in the exemplary arrangement in fig. 9. The inner surface of the lower flange 1200 can be modified to form an oval accelerator drum 1590 with a curved plate extending upwardly therefrom. These arrangements are intended to be exemplary and one skilled in the art may combine them in different ways or may modify these arrangements to further benefit from the turbidity reduction of the plates and the shape produced by the lower flange 1200 and/or the embedded accelerator drum.

Other features of an exemplary arrangement of a single-use centrifuge 1000 designed for continuous or semi-continuous operation are shown in fig. 10-12. The exemplary arrangement shown in fig. 10 includes a second centripetal pump 4400 for removing cell concentrate. The centripetal pump 4400 for removing cell concentrate is positioned above the centripetal pump 1400 for removing centrate. The radial pump 4400 includes a pump chamber 4420 and a scraping disk 4410. A plurality of holes or continuous slits 4540 extend from the upper outer circumference of the separation chamber 1550 into the pump chamber 4420 providing a fluid connection from the exterior of the separation chamber 1550 to the second pump chamber 4420. As with pump chamber 1400, pump chamber 4400 may have a different shape than that shown in fig. 10-12, but will be generally an axially symmetric chamber near the upper end of core structure 1500 that is fluidly connected to separation chamber 1550. As with pump chamber 1400, the pump chamber may be partially or fully recessed within core structure 1500. If the centrate pump chamber 1400 is present near the upper end of the core structure 1500, the cell concentrate pump chamber 4400 will be generally located above it. A pump chamber 4400 for removing cell concentrate will be in fluid connection with the separation chamber 1550 via an aperture or slit 4540 extending from near the outer upper wall of the separation chamber 1550 for collecting heavier cell concentrates propelled thereto by centrifugal force.

In the arrangement shown in fig. 10, the radius of the scraper discs 4410 for the concentrate discharge pump 4400 is substantially the same as the radius of the scraper discs for the filtrate discharge pump 1400 and is rotationally fixed. In other arrangements, such as the arrangement shown in fig. 11, the scraper discs 4410 in the concentrate discharge pump 4400 may have a larger radius than in the centrate discharge pump 1400, with a correspondingly larger pump chamber 4420. Various intermediate diameter scraping discs may also be used. The optimum diameter will depend on the nature of the cell concentrate to be discharged. Larger diameter paring discs have higher pumping capacity but produce more shear.

In the arrangement shown in fig. 1, 4 and 10, the paring disc 4410 in the concentrate discharge pump 4400 is rotationally fixed. In other arrangements, such as the arrangement shown in fig. 11, the paring disc 4410 may be adapted to rotate at an angular velocity between zero and the angular velocity of the centrifuge 1000. The desired angular velocity may be controlled by a variety of mechanisms known to those skilled in the art. One example of a control device is an external slip clutch that allows the scraping disk 4410 to rotate at an angular velocity that is a fraction of the angular velocity of the centrifuge 1000. Other means of controlling the angular velocity of the scraping disc will be apparent to the skilled person.

In the arrangement shown in fig. 1, 4, 10-12, the gap 1415, 4415 between the scraping discs 1410 and 4410 is fixed. In other arrangements, such as the arrangement shown in fig. 13, the gaps 1415, 4415 between the paring discs 1410 and 4410 may be adjustable to control the flow rate at which centrate or centrate is removed from the centrifuge 1000. One of each pair of scraping discs 1410 and 4410 is attached to a vertically movable throttle 6100. The throttle 6100 can be moved up or down to narrow or widen the gap 1415, 4415 between each pair of scraping discs 1410, 4410. Additionally, an external peristaltic pump 2510 (not shown) may be added to the concentrate removal line 2500 (not shown) to assist in removing the concentrate. This pump 2510 may be controlled by a sensor 4430 in a pump chamber 4420. A sensor 4430 (not shown) may also be used to control the diluent pump 5150 to synchronize the removal of concentrate with the addition of diluent.

Also shown in fig. 13 is an arrangement in which a centrate pump 1400 is located at the base of the centrifuge 1000. In the arrangement shown in fig. 13, a centrate well 1555 is created between the pumping chamber 1420 and the flexible liner 1100. An aperture 1530 extends from core 1510 into centrate well 1555 below pump chamber 1420. Additionally, in the exemplary arrangement shown, a bore 1540 extends from separation chamber 1550 into pump chamber 1420 adjacent outer surface 1515 of core 1510 to allow centrate removal using centrate pump 1400. A bore 4540 may also extend from between separation chambers 1550 to pumping chamber 4420 adjacent the upper surface of the exterior of the separation chamber to allow cell concentrate to flow into pumping chamber 4420 for removal using radial pump 4400.

As described above, in the exemplary arrangement shown, the clearances 1415, 4415 between the scraping discs 4410 and 1410 may be adjusted by using a throttle pipe 6100 connected to one of each pair of scraping discs 4410, 1410. The throttle pipe 6100 and the attached one of each scraper disk pair 4410, 1410 may move up or down to narrow or widen the gap 1415, 4415. In the exemplary arrangement shown, the throttle pipes 6100 are attached to the lower and upper shave discs of the pair of shave discs 4410, 1410, respectively. In other arrangements, the attachment may be reversed, may be used to throttle a single centripetal pump, or may be used to throttle both in parallel (rather than the opposite as shown in fig. 13).

As can be seen in the arrangement shown in fig. 10-12, the walls of the solid multi-use bowl 3100 are thicker at the base than in the upper portion thereof so as to create an internal truncated cone shape to support the single-use centrifuge structure 1000, which has a smaller radius at the lower end than at the upper end. This larger radius at the upper end of separation chamber 1550 moves the denser cell concentrate toward the upper exterior of separation chamber 1550 and into centripetal chamber 4420. In the arrangement shown, the truncated conical shape is produced by a multiple use drum 3100 having thicker walls at the base than it is in the upper portion. Those skilled in the art will recognize that the multi-use drum 3100 having an internal truncated cone shape may also include walls of uniform thickness, and that other variations may exist that produce the desired internal shape of the multi-use drum 3100.

In the exemplary arrangement shown in fig. 10-12, the feed mechanism 2000 also includes additional passages for removing cells or cell concentrates. In the arrangement shown in fig. 1, a cylindrical passageway 2200 around the feed tube 2100 is used to remove centrate. The arrangement shown in fig. 10-12 also includes a concentric cylindrical passageway, referred to as a cell drain 2500, for removing cells or cell concentrate. Cell drain tube 2500 surrounds centrate removal passage 2200. If the centrifuge is designed to be used with concentrates that are expected to be very viscous, an additional concentric cylindrical fluid passageway 5000 may be added around the feed tube 2100 to allow for the introduction of diluent into the cell concentrate pump chamber 4420 in order to reduce the viscosity of the concentrate. In the exemplary arrangement shown in fig. 12, the diluent passage 5000 comprises a concentric tube surrounding the cell discharge passage and opens at a lower end to a thin disc-shaped fluid passage 5100 above the scraping disc 4410, discharging near the outer edge of the scraping disc 4410 to provide fluid communication with the pump chamber 4420. Injecting the diluent at this location in this manner restricts the diluent from mixing with the concentrate and being discharged with the concentrate rather than being introduced into the centrate, which may be undesirable in some applications. In an alternative arrangement, the dilution liquid may be introduced directly onto the upper surface of the paring disc and allowed to expand radially outwards, or onto a separate disc located above the paring disc.

The choice of diluent will depend on the purpose of the separation process and the nature of the cell concentrate to be diluted. In some cases, a simple isotonic buffer or deionized water may be used as the diluent. In other cases, a diluent specific to the nature of the cell concentrate may be advantageous. For example, in production scale batch cell cultures operated at low cell viability, a flocculant is typically added to the culture as it is fed to the centrifuge to cause cells and cell debris to flocculate or aggregate into larger particles, which facilitates their separation by increasing their settling rate. Since both cells and cell debris carry a negative surface charge, compounds used as flocculants are typically cationic polymers, which carry multiple positive charges, such as polyethyleneimine. Due to its multiple positive charges, this flocculant can link negatively charged cells and cell debris into large aggregates. An undesirable result of using such a flocculant is that it further increases the viscosity of the cell concentrate. Thus, a diluent that is particularly useful in the present application is a deflocculant that will disrupt the binding that increases the viscosity of the cell concentrate. Examples of deflocculants include high salt buffers, such as sodium chloride solutions, at concentrations of 0.1M to 1.0M. Other deflocculants that may be used to reduce the viscosity of the cell concentrate are anionic polymers, such as polymers of acrylic acid.

In the case of cell concentrates in which cell viability is to be maintained, a diluent may be selected which is a shear protectant, such as dextran or Pluronic F-68. The use of a shear protectant, in combination with an isotonic buffer, will enhance the survival and viability of the cells upon discharge from the centrifuge.

The exemplary centrifuge shown in fig. 4 operates as follows. During a feed cycle, a feed suspension flows through feed tube 2100 into a rotating drum assembly. As the feed suspension enters the central cavity 1520 of the core 1510 near the lower flange 1200, it is forced outwardly by centrifugal force along the upper surface of the lower flange 1200 through the holes 1530 in the core 1510 into the separation chamber 1550.

The centrate collects in the separation chamber 1550, i.e., a hollow, generally cylindrical space around the core 1510 below the upper flange 1300. The centrate flows upwardly from its inlet into the separation chamber through the apertures 1530 until it encounters the apertures 1540 located between the separation chamber 1550 and the pump chamber 1420 adjacent the core 1410 in the upper part of the separation chamber 1550. Particles having a density higher than the density of the liquid move by settling (particle concentrate) towards the outer wall of the separation chamber 1550, away from the aperture 1530. When the rotation of centrifuge 1000 stops, the particulate concentrate moves downward under the influence of gravity to nozzle 2110 of feed tube 2100 for removal via combined feed/discharge mechanism 2000.

During rotation, centrate enters the centrate pump chamber 1420 through the apertures 1540. Within the pump chamber 1420, the rotating centrate encounters the stationary scraping disk 1410, which converts the kinetic energy of the rotating liquid into pressure that pushes the upwardly discharged centrate through the centrate discharge passage 2200 in the feed/discharge mechanism 2000 and discharges it through the centrate discharge tube 2400.

By adding radial fins 1630 on the inner surface 1620 of the cap 1610 of the rotary pump 1400, the efficiency of the centrifugal pump 1400 is increased. These vanes 1630 transfer the angular momentum of the rotating assembly to the centrate in the pump chamber 1420, which may otherwise slow due to friction as the rotating centrate encounters the stationary scraping disk 1410. The centrifugal pump 1400 provides an improved way of centrate drainage over mechanical seals due to the gas-liquid interface within the pump chamber 1420. The gas within the pump chamber 1420 is isolated from contamination of the external environment by the rotating seal 1700. Since the centrate discharged between the scraping discs 1410 is not in contact with air during either the feed or discharge process, it avoids excessive foaming that often occurs when the discharge process introduces air into the cell culture.

In the arrangement of centrifuge 1000 shown in fig. 4-5, cell concentrate is discharged by periodically stopping the bowl rotation and feed flow and then pumping out cell concentrate that has collected along the outer wall of separation chamber 1550. This process is called batch processing. When the volumetric capacity of the separation chamber 1550 is reached, centrifugal rotation is stopped. The cell concentrate moves down towards the nozzle 2110 of the feed tube 2100, where it is withdrawn by pumping the concentrate through the feed tube 2100. Suitable valves (not shown) external to centrifuge 1000 are used to direct the concentrate into a collection vessel (not shown). If the entire bioreactor batch has not been completely processed, drum rotation and feed flow is resumed, followed by additional feed and discharge cycles until the entire batch is processed.

As described above, when the cell culture is concentrated or contains a large amount of cell debris, the above process slows down because the residence time must be increased to capture small debris particles, which necessitates slower feed flow rates and fast filling of the separation chamber 1550, and frequent and repeated stops of rotation for each culture batch. In addition, cell concentrates tend to be more viscous, so gravity cannot effectively drain the cell concentrate to the bottom of centrifuge 1000, taking longer, and in some cases, washing may be required to remove the remaining cells.

As improved in the exemplary arrangements shown in fig. 6-13, a single use centrifuge produces a higher average sedimentation velocity without increasing angular velocity, allows the centrifuge 1000 to run continuously or semi-continuously, and allows diluent to be added to the cell concentrate during the cell removal process, making removal of cells easier and more complete.

The single-use centrifuge structure 1000 shown in fig. 6-12 operates as described herein. The feed suspension enters the single-use centrifuge arrangement 1000 via feed tube 2100. As the feed suspension encounters accelerator blade 1560, blade 1560 imparts an angular velocity to the feed suspension that approximates the angular velocity of single-use centrifuge 1000. The use of vanes 1560 instead of apertures 1530 provides for a greater volume of feed suspension to enter the separation chamber 1550 through a slower radial velocity, avoiding jetting that occurs when the feed suspension is forced through apertures 1530 having smaller cross-sectional openings than the openings between vanes 1560. This reduction in feed stream velocity minimizes disruption of the liquid contents in the tank as the feed stream enters the separation zone or tank, which allows for more efficient settling.

As centrifuge 1000 rotates, particles of a density greater than the centrate are pushed outward of separation chamber 1550, leaving a particle-free centrate adjacent core 1510. Centrifuge bowl 3100 has the shape of an inverted truncated cone with a wider radius at the upper end than at the lower end. Centrifugal forces cause particles to collect in the upper and outer parts of the chamber. The centrifuge 1000 may operate in a semi-continuous discharge of concentrate. Centrate discharge generally operates as described with reference to figure 4. Cell concentrate discharge works similarly, where cell concentrate collects near the upper exterior of the separation chamber 1550 and enters the concentrate discharge pump chamber 4400 via the aperture 4540 near the upper exterior wall of the separation chamber 1550.

Sensors (including but not limited to a vibration sensor system such as that described in U.S. patent No. 9,427,748, the entirety of which is incorporated herein by reference) may be used to monitor the feed rate of the suspension and the rotational angular velocity. Such a sensor system allows the centrifuge to be filled at a lower rate until the sensor arrangement indicates that the centrifuge is nearly full, and then the feed rate and angular velocity are appropriately adjusted in response to this information. Typically, once the centrifuge is close to full, the feed rate is reduced or stopped, and the angular velocity will be increased to increase the settling velocity, and once settling and discharge are substantially complete, the cycle will be repeated. If the system is optimized using the additional features described herein to reduce the need to interrupt the process, it is possible to operate the system continuously or nearly continuously at the angular velocity required for settling.

In the case of semi-continuous concentrate discharge, the suspension is continuously fed into the centrifuge 1000 using the concentrate pump 4400 which operates intermittently to remove the concentrate. The operation of the concentrate pump 4400 may be controlled by an optical sensor in the concentrate discharge line that indicates the presence or absence of discharged concentrate. Instead of the concentrate pump 4400, the discharge cycle may be electronically managed using a controller and sensors that determine when to open and close the valves in order to most effectively process the fluid suspension.

The average discharge rate can be further controlled by using a centrifuge 1000 with an adjustable gap between the paring discs 4410, 1410. It should be noted that it may only be desirable or necessary that one set of scraping discs 4410, 1410 be adjustable. The gap between the scraping discs 4410, 1410 (which forms part of the fluid path exiting the centrifuge 1000) may be opened to allow flow or closed to shut off flow, thereby acting as an internal valve. Widening or narrowing the gap 4415, 1415 between the scraping discs 4410, 1410 may also be useful depending on the desired product or characteristics of the product. Changing the clearance affects the pumping and shear rates associated with the scraping disk.

The rate at which concentrate and centrate are removed from the centrifuge 1000 and the viability of the removed concentrate may be further controlled using a number of features of the exemplary arrangements shown in fig. 4-13. Accelerator vanes 4630, similar to those in the centrate pump chamber 1420, may be added to the concentrate pump chamber 4420. The addition of accelerator vanes 4630 increases the rate at which concentrate may be removed by overcoming some of the deceleration caused by friction between the moving concentrate and the scraping discs 4410. In addition to accelerator tabs 4630 in the upper surface of pump chamber 4420, such tabs 4630 may also be added to the lower surface in pump chamber 4420 to increase its effectiveness. Another feature may be to replace the apertures 1540, 4540 with slits, which minimizes shearing on the material entering the pump chambers 1420, 4420.

If the vigor of the concentrate is important, a rotatable scraping disc 4410 may be included in the pump chamber 4420, which reduces the shear force applied to the concentrate when the concentrate contacts the surface of the scraping disc 4410. The rate of rotation of the scraping disc 4410 can be adjusted to a rate that is somewhat between the fixed value and the rate of rotation of the separation chamber 1550 to balance the concentrate vigor and the discharge rate. The desired angular velocity may be controlled by a variety of mechanisms known to those skilled in the art. One example of a control device is an external slip clutch that allows the scraping disk to rotate at an angular velocity that is a fraction of the angular velocity of the centrifuge. The use of slip clutches is well known to those skilled in the art. In addition, there may be devices other than slip clutches to adjust the angular velocity, as will be apparent to those skilled in the art.

Peristaltic pumps 2510 may also be used to make removal of the concentrate more efficient and reliable, particularly for very concentrated feed suspensions. The use of the peristaltic pump 2510 allows a user to more accurately control the flow rate of concentrate from the centrifuge 1000 than is possible by relying on the centrifugal pump 4400 alone, as the rate of the centrifugal pump is not as easily adjusted as the rate of the peristaltic pump 2510.

In addition, to reduce the viscosity of the concentrate, a diluent pump 5150 may be used to pump a diluent such as sterile water or buffer into the concentrate pump chamber 4420 through the diluent passage 5000. A more comprehensive and useful discussion of the dilution can be found above. The operating rate of either or both of the peristaltic pump 2510 or the diluent pump 5150 may be controlled by an automatic controller (e.g., as discussed later) responsive to a concentration sensor 4430 located in the concentrate discharge connection 2500. The controller can be programmed to start, stop, or vary the pumping rates for diluent addition and concentrate removal in response to the concentration of particles in the concentrate (independently in response to the concentration sensor 4430, in conjunction with a standard feed/discharge cycle, or as a combination).

Fig. 16 shows an alternative example arrangement of a core for use in conjunction with a centrifuge that provides a continuous separation process to produce a continuous supply of concentrate and centrate. The core 10 is similar to those previously discussed, and is configured to be positioned in a rotatable bowl of a centrifuge. During processing, the centrifuge bowl and core rotate about axis 12. The apparatus includes a stationary assembly 14 and a rotatable assembly 16.

As with the previously described arrangement, the stationary assembly 14 includes a feed tube 18. The feed tube 18 is coaxial with the axis 12 and terminates in an opening 20 at the bottom of a separate chamber or cavity 22 adjacent the core. The stationary assembly also includes a centrate centripetal pump 24, and an exemplary arrangement of the centrate pump 24, which will be described in greater detail below, includes an inlet 26 and an annular outlet 28. The annular outlet is in fluid connection with a centrate tube 30. The centrate tube extends in coaxial surrounding relation to the feed tube 18.

In this exemplary arrangement, the centrate radial pump 24 is positioned in the centrate pump chamber 32. The centrate pump chamber is defined by a wall that is part of the rotatable assembly and which provides the centrate inlet 26 of the centrate pump during operation to be exposed to a pool of liquid centrate.

The exemplary arrangement also includes a concentrate centripetal pump 34. The concentrate centripetal pump 34 of this example arrangement may also have a configuration similar to that discussed in detail later. In the exemplary arrangement, the concentrate centripetal pump 34 includes an inlet 36 positioned in a wall defining an annular periphery of the centripetal pump. It should be noted that the concentrate centripetal pump 34 has a peripheral diameter that is greater than the peripheral diameter of the centrate pump. The concentrate pump also includes an annular outlet 38. The annular outlet 38 is fluidly connected to a concentrate outlet tube 40. The concentrate outlet tube extends in coaxial surrounding relationship with the centrate tube 30.

In this exemplary arrangement, the inlet 36 of the concentrate centripetal pump is positioned in the concentrate pump chamber 42. The concentrate pump chamber is defined by the walls of the rotatable assembly 16. During operation, the concentrate is exposed to the inlet 36 of the centrifugal pump to concentrate in the concentrate pump chamber 42. The concentrate pump chamber 42 is vertically bounded by a top 44. At least one fluid seal 46 extends between the outer circumference of the outlet tube 40 and the top 44. The example seal 46 is configured to reduce the risk of fluid escaping from the interior of the separation chamber and prevent contaminants from being introduced from the exterior region of the core therein.

During operation of the centrifuge, the bowl and the core including the cavity or separation chamber rotate in a rotational direction about axis 12. Rotation in the direction of rotation is operable to separate a cell suspension introduced through the feed tube 18 into centrate discharged through the centrate tube 30 and concentrate discharged through the concentrate outlet tube 40.

The cell suspension enters the separation chamber 22 through the tube opening 20 at the bottom of the separation chamber. The cell suspension moves outward via centrifugal force and a plurality of accelerator blades 48. As the suspension moves outwardly through the accelerator blades, centrifugal forces act on the cell suspension material causing the cell material to move outwardly towards the annular conical wall 50 defining the outside of the separation chamber. As shown, the concentrated cellular material is urged to move outwardly and upwardly against the tapered wall 50 and through the plurality of concentrate channels 52. The concentrate material moves upwardly beyond the concentrate tank and into the concentrate pump chamber 42 from which the concentrate is discharged by the concentrate centripetal pump 34.

In the exemplary arrangement, during operation, the cell-free centrate is positioned proximate a vertical annular wall 54 that defines the interior of the separation chamber 22. The centrate material moves upwardly through centrate holes 56 in an annular base structure defining the centrate pump chamber 32. The centrate moves upward through the centrate holes 56 and forms a pool of liquid centrate in the centrate chamber. Centrate is moved from the centrate chamber by operation of the centrate towards the centrifugal pump 24 and is delivered from the core through the centrate tube 30.

In the exemplary arrangement of fig. 16, the concentrate pump and centrate pump may have a configuration substantially similar to that shown in fig. 17. In fig. 17, the centrate centrifugal pump 24 is shown in an isometric exploded view. As shown in fig. 17, the exemplary centripetal pump has a disc-shaped body formed by a first plate 58 and a second plate 60. During operation, the first and second plates are held in releasably engaged relationship via fasteners represented by screws 62. It will of course be appreciated that other constructions and fastening methods may be used in other arrangements.

In this exemplary arrangement, the second plate 60 includes three side walls that define a curved volute channel 64. It should be appreciated that while in this exemplary arrangement, the centripetal pump includes a pair of generally opposed volute channels 64. Other numbers and configurations of volute passages may be used in other arrangements.

In this exemplary arrangement, the first and second plates constitute a disc-shaped body of the centripetal pump having an annular vertically extending wall 67 defining an annular periphery 66. An inlet 68 to the volute passage 64 extends in the annular periphery. An annular collection chamber 70 extends radially outward from the axis 12 in the disc-shaped body and is fluidly connected to the volute passage. An annular collection chamber 70 receives material entering the inlet 68. The annular collection chamber 70 is fluidly connected to an annular outlet coaxial with the axis 12. In the exemplary arrangement of the centrate centrifugal pump, the annular outlet is an annular space extending between the outer wall of the feed tube 18 and the inner wall of the second plate 60, which outlet is fluidly connected to the centrate outlet tube 30.

In this exemplary arrangement, each volute passage 64 is configured such that the volute passage curves toward the direction of rotation of the bowl and separation chamber, which is indicated by arrow R in fig. 17. In this example structure, the vertically extending walls 74 that define the volute passage and face the direction of rotation are each curved toward the direction of rotation. The curved configuration of the wall 74 horizontally bounding the volute passage provides enhanced pumping characteristics of this exemplary arrangement. Furthermore, the opposing bounding walls 76 of each volute channel in this exemplary arrangement have a similar curved configuration. The curved configuration of the vertically extending wall horizontally bounding the volute channels provides a constant cross-sectional area of each volute channel from the respective inlet to the collection chamber. This uniform cross-sectional area is further achieved by using a generally flat wall 78 that extends between walls 74 and 76 and vertically defines a volute channel on one side. Further, in this exemplary arrangement, the first plate 58 includes a generally flat circular face 80 on a side thereof that faces inwardly when the plates are assembled to form a disc-shaped body of the centripetal pump. In this exemplary arrangement, the face 80 serves to vertically bound the sides of the two volute channels 64 of the centrifugal pump.

Of course, it should be understood that this exemplary arrangement including a pair of plates is exemplary, with one plate including a recess having a wall defining three of the four sides of the curved volute passage and the other plate including a surface defining the remaining side of the volute passage. It should be understood that other configurations and structures may be used in other arrangements.

In the exemplary centripetal pump structure shown in fig. 16, a centripetal pump structure is used and has the ability to move more liquid than a scraped disc type centripetal pump of equal size. Furthermore, this exemplary configuration produces less heating of the liquid than a comparable paring disc.

Furthermore, in the exemplary arrangement as previously described, the annular periphery of the centrate centripetal pump 24 has a smaller outer diameter than the periphery of the concentrate centripetal pump 34. In this exemplary arrangement, this configuration serves to avoid the centrate centrifugal pump removing excess liquid from the pool of liquid centrate formed in the centrate pump chamber 32. Ensuring that there is sufficient liquid centrate within the centrate pump chamber helps ensure that no waves are formed in the centrate near the inlet of the centrate radial pump. Waves formed due to insufficient liquid centrate may cause vibration and other undesirable properties of the centrifuge and core.

The larger annular perimeter of the concentrate pump of this exemplary arrangement causes material to preferentially flow out of the core via the concentrate centripetal pump. In this exemplary arrangement, the concentrate flow downstream of the concentrate outlet conduit 40 can be controlled to control the ratio of centrate flow to concentrate flow from the core.

Further, in an exemplary arrangement, with a centripetal pump having the described configuration, the properties and flow characteristics of the centrifuge may be tailored to the requirements of the particular material and separation process being performed. In particular, the diameter of the annular periphery of the centripetal pump may be sized to achieve optimal properties for a particular treatment activity. For example, the larger the diameter of the periphery of the centripetal pump, the greater the flow and pressure achievable at the outlet. In addition, larger diameters tend to produce greater mixing than relatively smaller diameters. However, the larger diameter also results in greater heating than the smaller peripheral diameter of the centripetal pump. Thus, to achieve less heating, a smaller diameter perimeter may be used. Further, it should be understood that different sizes, areas and numbers of inlets, as well as different volute channel configurations, may be utilized as desired to vary flow and pressure properties for the purposes of a particular separation process.

Fig. 19 schematically illustrates an exemplary system for helping to ensure positive pressure within a separation chamber, alternatively referred to herein as a chamber, during cell suspension processing. As discussed in connection with the previous exemplary arrangements, it is generally desirable to ensure a positive pressure above atmospheric pressure within the separation chamber at all times. Doing so reduces the risk of contaminants being introduced into the separation chamber by permeating through one or more fluid seals operatively extending between the fixed and rotatable components of the core. As further noted above, it is also generally desirable to maintain air under positive pressure within the separation chamber in contact with the inner surface of the fluid seal. The presence of an air pocket adjacent the seal avoids the seal coming into contact with the material being processed and further helps to reduce the risk of contaminants being introduced into the processed material and any material escaping from the separation chamber.

The exemplary system described in connection with fig. 19 is used to maintain a consistent positive pressure in the separation chamber and reduce the risk of the introduction of contaminants and the escape of processed materials.

As schematically shown in fig. 19, the centrifuge includes a rotatable bowl 82. The centrifuge bowl may be rotated about axis 84 by a motor 86 or other suitable rotating device.

The exemplary centrifuge structure shown includes a rotatable single-use core 88 that defines a cavity 90, which is alternatively referred to herein as a separation chamber.

Similar to the other previously described arrangements, the exemplary core includes a stationary assembly including a suspension inlet feed tube 92 having an inlet 94 located near a bottom region of the chamber. The stationary assembly further includes at least one centripetal pump 96. The centripetal pump of this example arrangement includes a disc-shaped body having at least one pump inlet 98 adjacent its periphery and a pump outlet 100 adjacent the center of the centripetal pump. The pump outlet is fluidly connected to centrate outlet duct 102. The centrate outlet tube extends in coaxially surrounding relation to the suspension inlet tube in a manner similar to that previously discussed. The rotatable top 104 of the fluid-containing separation chamber is in operative connection with at least one seal 106 which operates to fluidly seal the cavity of the core with respect to the inlet and outlet pipes. The at least one seal 106 operatively extends in sealing relation between an outer annular surface of the stationary centrate outlet tube 102 and the rotatable top 104 of the core having an upper inner wall that bounds the chamber 90 internally as shown.

In this exemplary arrangement, the inlet tube 92 is fluidly connected to a pump 108. In one exemplary arrangement, the pump 108 is a peristaltic pump that efficiently pumps the cell suspension without causing damage thereto. Of course, it should be understood that this type of pump is exemplary, and that other types of pumps may be used in other arrangements. Further, in this exemplary arrangement, pump 108 is reversible. This enables pump 108 to act as a feed pump to enable pumping of the cell suspension from inlet line 110 into the inlet tube at a controlled rate. Further, in this exemplary arrangement, the pump 108 may be operated as a concentrate removal or drain pump after the cell concentrate has been separated by centrifugation. In performing this function, the pump 108 operates to pump the cell concentrate out of the separation chamber by reversing the flow of material in the inlet tube 92 with the flow when feeding the cell suspension into the separation chamber. The cell concentrate is then pumped to the concentrate line 112. As shown in fig. 19, the inlet line 110 and the concentrate line 112 may be selectively opened and closed by valves 114 and 116, respectively. In this exemplary arrangement, valves 114 and 116 comprise pinch valves that open and close flow through flexible lines or tubing. Of course, it should be understood that this method is exemplary, and that other methods may be used in other arrangements.

In the exemplary system, centrate outlet tube 102 is fluidly connected to centrate discharge line 118. The centrate discharge line is fluidly connected to a centrate discharge pump 120. In this exemplary arrangement, centrate discharge pump 120 is a variable flow pump that can selectively adjust its flow rate. For example, in some example arrangements, the pump 120 may comprise a peristaltic pump including a motor, the speed of which may be controlled to selectively increase or decrease the flow rate through the pump. The outlet of the centrate discharge pump delivers the treated centrate to a suitable collection chamber or other treatment device.

In the exemplary arrangement schematically illustrated in fig. 19, the pressure damping reservoir 122 is fluidly connected to the centrate discharge line 118 that is fluidly intermediate the centrate outlet tube 102 and the pump 120. In this exemplary arrangement, the pressure damping reservoir includes a generally vertically extending container having an interior region configured to contain the liquid centrate in fluid-tight relation. The pressure damping reservoir includes a bottom port 124 fluidly connected to the centrate discharge line 118.

On the opposite side of the reservoir 122 is a top port 126. The top port is exposed to air pressure. In this exemplary arrangement, the top port is exposed to air pressure from a high air pressure source, schematically indicated at 128. In this exemplary arrangement, the high pressure source may include a compressor, air accumulator, or other suitable device for providing a source of high air pressure above atmospheric pressure within a desired range of system operation. Air from high pressure source 128 passes through a sterile filter 130 to remove impurities therefrom. The regulator 132 is operable to maintain a substantially constant air pressure level above atmospheric pressure at the top port of the pressure damping reservoir. In an exemplary arrangement, the air pressure regulator includes an electronic quick-acting regulator to help ensure a substantially constant air pressure is maintained at a desired level. The example fast-acting regulator 132 operates to rapidly increase the pressure acting at the top port 126 when the pressure drops below a desired level, and to rapidly decrease the pressure through the regulator if the pressure acting at the top port is above the set point of the regulator.

In some arrangements, the regulator outlet may also be operatively fluidly connected to the interior of the top 104 of the separation chamber by an air line 143, shown schematically in phantom. In this exemplary arrangement, the outlet pressure of the regulator acting on the top port 126 of the accumulator also acts through the air line 143 on a pocket of air inside the separation chamber that extends down to the level in the chamber above the centripetal pump inlet and on the inside of the at least one seal 106 and radially from a region adjacent the axis 84 to the upper inner wall on the inside of the top 104. In this exemplary arrangement, line 143 applies positive pressure to the area within the separation chamber below the at least one seal through at least one isolation channel extending through the fixed structure of the assembly comprising centrate outlet tube 102 and inlet feed tube 92. The at least one example isolation channel of air line 143 applies air pressure to the interior of top 104 through at least one air opening 145 to the separation chamber. The exemplary at least one opening 145 is positioned outside of the outer surface of the outlet tube 102, above the inlet 98 of the centrifugal pump and below the at least one seal 106. Of course, it should be understood that this described structure for an exemplary air line providing positive air pressure to the air pocket in the separation chamber and on the inside of the at least one seal is exemplary, and that other structures and methods may be used in other arrangements.

In the exemplary arrangement of the pressure damping reservoir 122, the upper level sensor 134 is configured to sense a liquid centrate inside the pressure damping reservoir. The upper level sensor is operable to sense liquid at an upper level. The lower level sensor 136 is positioned to sense liquid in the reservoir at a lower level. A high level sensor 138 is positioned to detect a high level in the reservoir above the upper level. The high level sensor is positioned to sense a liquid level at an unacceptably high level to indicate an abnormal condition that may require shutting down the system or other appropriate safety measures. In this exemplary arrangement, level sensors 134, 136 and 138 comprise capacitive proximity sensors adapted to sense the level of liquid centrate adjacent thereto within the pressure damping reservoir. Of course, it should be understood that these types of sensors are exemplary, and that other sensors and methods may be used in other arrangements.

The exemplary arrangement also includes other components as long as they can be adapted for operation of the system. This may include other valves, lines, pressure connections, or other suitable components to perform the processing and handling of the suspension, centrate, and concentrate as required by a particular system. This may include additional valves, such as the schematically illustrated valve 140, for controlling the open and closed state of the centrate discharge line 118. The additional lines, valves, connections or other items included may vary depending on the nature of the system.

The exemplary system of fig. 19 also includes at least one control circuit 142, which may alternatively be referred to as a controller. The exemplary at least one control circuit 142 includes one or more processors 144. The processor is operatively connected to one or more data stores, schematically indicated at 146. As used herein, a processor refers to any electronic device configured to operate via processor-executable instructions to process data stored in the one or more data stores or received from an external source, parse information, and provide output that may be used to control other devices or perform other actions. The one or more control circuits may be implemented as hardware circuits, software, firmware, or applications that are operable to enable the control circuits to receive, store, or process data and perform other actions. For example, the control circuitry may include one or more of a microprocessor, CPU, FPGA, ASIC, or other integrated circuit or other type of circuit capable of performing functions in the manner of an electronic computing device. Further, it is understood that the data storage may correspond to one or more of volatile or non-volatile memory devices such as RAM, flash memory, hard drives, solid state devices, CDs, DVDs, optical storage, magnetic storage, or other circuit-readable media or media on which computer-executable instructions and/or data may be stored.

The circuit-executable instructions may include instructions in any of a variety of programming languages and formats, including but not limited to routines, subroutines, programs, threads of execution, objects, scripts, methods, and functions to perform actions such as those described herein. The structure of the control circuit may include, correspond to, and utilize the principles described in Ramesh s. Ganker's textbook entitled "microprocessor architecture model 8085, programming and applications" (prentic Hall, 2002), which is incorporated by reference herein in its entirety. Of course, it should be understood that these control circuit configurations are exemplary and that other circuit configurations for storing, processing, parsing and outputting information may be used in other arrangements.

In this exemplary arrangement, the at least one control circuit 142 is operatively connected with at least one sensor (e.g., sensors 134, 136 and 138) via a suitable interface. The at least one control circuit is also operatively connected to the variable flow rate discharge pump 120. Further, in some example arrangements, the at least one control circuit may also be operatively connected with other devices, such as the motor 86, the pump 108, the regulator 132, the pneumatic pressure source 128, fluid control valves, and others.

The exemplary at least one control circuit is operative to receive data and control these devices in accordance with circuit-executable instructions stored in a data storage 146. In this exemplary arrangement, fluid level 147 in the fluid damping reservoir is a property that corresponds to the pressure in centrate discharge tube 102. In one exemplary implementation that does not utilize air line 143, the fact that the pressure in the centrate discharge tube indicates the nature of the pressure in the top 104 of the core and the pressure in the separation chamber adjacent seal 106 is used to control the operation of the discharge pump and other components. As previously mentioned, it is desirable to maintain a positive pressure above atmospheric pressure and a pocket of air adjacent the at least one seal within the separation chamber to avoid the introduction of contaminants into the separation chamber that may result from the negative pressure. However, if the fluid level within the separation chamber becomes too high, the pressure and suspension material being processed may overflow the seal, which may lead to potential contamination and undesirable exposure and loss of processed material. This may be due to a situation where the backpressure on the centrate line connected to the outlet of the centripetal pump is too high.

In this exemplary arrangement, the drum speed produces a corresponding pumping force and pump output pressure level for the centripetal pump. This pump output pressure level of the centripetal pump varies with the rotational speed of the drum and the core. An exemplary arrangement that does not use air line 143 provides a controlled back pressure on the centrate outlet tube. The back pressure is provided by controlling the speed of the motor operating the pump 120 and the fluid level 147 in the pressure damping reservoir. The back pressure is maintained at a level less than the pump output pressure (so that the centripetal pump can convey the centrate out of the separation chamber), but at a positive pressure above atmospheric pressure to ensure that contaminants do not penetrate through the seal into the separation chamber, and so that air at elevated pressure is maintained inside the separation chamber adjacent the seal to isolate the seal from the components of the suspension being processed.

In this exemplary arrangement, the elevated pressure applied to the top port 126 of the pressure damping reservoir is maintained by the regulator 132. In addition, the speed of pump 120 is controlled by the at least one control circuit 142 to maintain the fluid level 147 between the upper and lower fluid levels 136 sensed by sensor 134, controlling the centrate flow exiting the separation chamber such that the pressure in the top region of the separation chamber is maintained at a desired constant value and the centrate does not contact or spill over the seals.

In an alternative arrangement using the air line 143, the positive pressure water level of the regulator acts on the fluid in the reservoir 122 and on the area of the separation chamber above the centripetal pump inlet. Since the positive pressure level of the air applied at both locations is the same, the back pressure on the centrate discharge line (which is the pressure applied above the fluid in the reservoir) is virtually always the same as the pressure in the air pocket at the top of the separation chamber. This enables the centripetal pump to operate without any net effect from either pressure.

In this exemplary arrangement, the pump 120 and other system components are controlled in response to the at least one control circuit 142 to ensure that a sufficient volume of air is always present inside the reservoir 122 during centrate production. This ensures that the reservoir provides the desired dampening effect on changes in centrate discharge line pressure that may otherwise be caused by the pumping action of the pump 120. This is accomplished by maintaining the liquid in the reservoir 122 at a level no higher than the upper level detected by the sensor 134. In addition, the liquid level in the reservoir is controlled to remain above the lower liquid level sensed by sensor 136. This ensures that the centripetal pump does not pump air and aerate the centrate.

In this exemplary arrangement, the centrate flow exiting the separation chamber is controlled by operation of the at least one control circuit. The exemplary control circuit may operate the system during processing conditions to maintain a flow of cell suspension through pump 108 into separation chamber 90 at a substantially constant rate, while the separation process occurs with motor 86 operating to maintain a constant drum speed to effect separation of the centrate and cell concentrate. The exemplary arrangement also operates to maintain a desired constant back pressure from the centrifugal pump on the centrate discharge line while maintaining air in the separation chamber above the level of the lower side of the air pocket to isolate the at least one seal 106 from the centrate and concentrate materials being processed.

In one exemplary arrangement, the pressure maintained in the pressure damping reservoir by operation of the regulator is set at about 2kPa (0.29 psi) above atmospheric pressure. In this exemplary system, this pressure has been found to be suitable to ensure that seal integrity and isolation is maintained during all stages of cell suspension processing. Of course, it should be understood that this value is exemplary, and in other arrangements, other pressure values and pressure damping reservoir configurations, sensors, and other features may be utilized.

Fig. 20 schematically illustrates exemplary logic performed by operation of the at least one control circuit 142 in connection with maintaining a desired pressure level in the centrate discharge tube and within the top of the separation chamber. It should be understood that in some example arrangements, the control circuit may perform many additional or different functions in addition to those shown. In addition to the pressure control functions, these functions may include overall control of the various processes and steps for centrifuge operation. As shown in fig. 20, in an initial subroutine step 148, the at least one control circuit 142 is operable to determine whether centrifuge operation is currently in a mode in which centrate is being discharged from the separation chamber. If so, the at least one control circuit is operable to cause the centrate discharge pump 120 to operate to discharge the feed centrate through the centrate discharge line 118. This may be done by operating the motor of the pump. In this exemplary arrangement, the flow rate of the pump 120 may be initially a set value, or alternatively may vary depending on the particular operating conditions determined by the control circuit operation during the process. Operation of the centrate discharge pump is represented by step 150.

Then, in step 152, the at least one control circuit is operable to determine whether liquid is sensed at a high level of high level sensor 138. If so, this represents an undesirable condition. If liquid is sensed at the level of sensor 138, the control circuitry operates to take action to address the condition. This may include operating the pump 120 to increase its flow rate and making a subsequent determination if the liquid level drops for a period of time while the centrifuge continues to operate. Alternatively or additionally, the at least one control circuit may reduce the speed of the pump 108 to reduce the flow of the incoming material. If such action does not result in the liquid level falling within a set period of time, additional steps are taken. These steps may also include slowing or stopping the rotation of the drum 182. These actions may also include stopping operation of pump 108 to avoid introducing more suspension material into the separation chamber. These steps, which are commonly referred to as shutting down the normal operation of the system, are represented by step 154.

If no liquid is sensed at the level of high level sensor 138, the at least one control circuit is next operable to determine if liquid is sensed at the upper level of sensor 134. This is represented by step 156. If liquid is sensed at the upper level sensor, the at least one circuit operates in response to its stored instructions to increase the speed of the drain pump 120 and thus its flow rate. In one exemplary arrangement, this is achieved by increasing the speed of a motor that is part of the pump. This is represented by step 158. Increasing the flow rate of the pump causes the liquid level 147 in the pressure damping reservoir to begin to decrease as the pump 120 moves more liquid.

If no liquid is sensed at the upper level of sensor 134 in step 156, the at least one control circuit then operates to determine if no liquid is sensed at the lower level of sensor 136. This is represented by step 160. If the level is not at the level of sensor 136, the control circuit operates according to its programming to control pump 120 to reduce its flow rate. In one exemplary arrangement, this is achieved by slowing the speed of the motor. This is represented by step 162. In this exemplary arrangement, slowing the flow rate of the pump 120 causes the liquid level 147 to begin to rise in the pressure damping reservoir. In some exemplary arrangements, if the liquid level within the reservoir does not rise within a given time, the control circuitry may operate according to its programming to cause additional actions, such as those associated with the shutdown step 154 discussed previously. The control circuitry of the exemplary arrangement is operable to vary the pumping rate of the pump 120 to maintain the liquid level 147 within the pressure damping reservoir at a substantially constant level between the levels of the sensors 134 and 136 during centrate production.

In this exemplary arrangement, maintaining a substantially constant elevated pressure of sterile air above the liquid in the pressure damping reservoir helps ensure that a similar elevated pressure is consistently maintained in the centrate outlet line and at the seal within the separation chamber. Further, in this exemplary arrangement, the pressure is enabled to be controlled at a desired level during different operating conditions of the centrifuge during which the bowl is rotated at different speeds. This includes, for example, conditions during which the separation chamber is initially filled at a relatively high rate by introducing the cell suspension, and during which the centrifuge is rotated at a relatively low speed. During subsequent final filling conditions, the pressure may also be maintained, wherein the flow rate of the cell suspension into the separation chamber occurs at a slower rate, and during this the rotational speed of the drum is increased to a higher rotational speed. Further, during feeding of the suspension into the rotary drum and during discharge of the centrate from the separation chamber, a positive pressure is maintained as previously discussed. Further, in an exemplary arrangement, the at least one control circuit may be operative to maintain a positive pressure also during a period of time when concentrate is removed by pumping the concentrate out of the separation chamber. Maintaining a positive pressure within the separation chamber during all of these conditions reduces the risk of contamination and other undesirable conditions that might otherwise arise due to negative (sub-atmospheric) pressure conditions.

Of course, it should be understood that the features, components, structures, and control methods are exemplary and that other methods may be used in other arrangements. Furthermore, while the exemplary arrangement includes a system that operates in a batch mode rather than a mode in which both centrate and concentrate are processed continuously, the principles thereof may also be applied to such other types of systems.

While an exemplary arrangement may be used to help ensure that a desired pressure level is maintained in the outlet duct and the separation chamber, other methods may be utilized in other exemplary arrangements. For example, in some arrangements, the pressure may be sensed and/or applied directly in the outlet tube, in the separation chamber, or in other locations corresponding to the pressure in the separation chamber. In some arrangements, the flow rate of the discharge pump may be controlled in order to maintain a suitable pressure level. In other arrangements, the exemplary control circuitry may be operative to control the discharge pump and the pump that supplies the suspension into the core and/or appropriate valves or other flow control devices in order to maintain the appropriate pressure levels. Such alternative methods may be required depending on the particular centrifuge apparatus used and the type of material being processed.

Fig. 21 schematically shows an alternative centrifuge system 170 specifically configured to continuously or semi-continuously separate cells in a cell culture batch into a cell centrate and a cell centrate. The exemplary system shows a rigid centrifuge bowl 172 that is rotatable about an axis 174. The rotating drum includes a cavity 176 configured to releasably receive a single-use configuration 178 therein. The rigid drum includes an upper opening 180. An annular securing ring or other securing structure, schematically indicated at 182, enables the single-use structure 178 to be releasably secured within the drum cavity.

The exemplary single-use construction 178 of this exemplary arrangement includes a central axially extending feed tube 184. As discussed later, the feed tube is used to deliver the cell culture batch material into the interior region 186 of the single-use construction 178. The feed tube 184 extends from an upper portion at the first axial end 188 of the single-use device to an opening 190 in the interior region at a lower portion at the second axial end 192. The single-use construction 178 includes a substantially disc-shaped portion 194 adjacent the first axial end. The exemplary disc portion 194 is substantially rigid, meaning that it is rigid or semi-rigid, and includes an annular outer periphery 196. The annular outer periphery is configured to engage an upper annular bounding wall 198 of the centrifuge bowl chamber 176. The annular outer periphery of the disc portion 194 is configured to engage the rigid drum 172 such that the single-use configuration rotates therewith.

The exemplary single-use construction 178 also includes a hollow rigid or at least semi-rigid cylindrical core 200. The core 200 is operatively engaged with the disc portion 194 and rotatable therewith. The core 200 is axially aligned with the disk portion and extends axially intermediate the upper and lower portions of the single-use configuration. The core 200 includes an upper opening 202 and a lower opening 204 through which the feed tube 184 extends.

The disk portion 194 includes a substantially circular centrate centripetal chamber 206. A centrate centripetal pump 208 is positioned in the pump chamber 206. A substantially annular centrate opening 210 is fluidly connected to the centrate pump chamber 206. By substantially annular it is meant that the opening may consist of an annular arrangement of discrete openings and/or a continuous opening. Centrate discharge tube 212 is fluidly connected to centrate feed pump 208. The centrate discharge tube 212 extends in coaxial surrounding relation to the feed tube 184. The discharged centrate passes through a substantially annular opening in the centrate discharge tube 212 towards the periphery of the centrifugal pump and through an annular space in the centrate discharge tube outside the feed tube.

The disc portion 194 also includes a concentrate centripetal chamber 214. The concentrate centripetal chamber 214 is a substantially circular chamber positioned above the centrate centripetal chamber 206. The concentrate centripetal chamber 214 has a concentrate centripetal pump 216 positioned therein. The concentrate radial pump is fluidly connected to the concentrate discharge line 220. The concentrate discharge tube 220 extends in an annular relationship around the centrate discharge tube 212. The concentrate passes through a substantially annular opening at the periphery of the concentrate centripetal pump and through an annular space in the concentrate discharge tube 220 outside the centrate discharge tube.

A substantially annular concentrate opening 218 is fluidly connected to the concentrate pump chamber 214. In this exemplary arrangement, the substantially annular concentrate opening and the substantially annular centrate opening are concentric coaxial openings, with the concentrate opening being disposed radially outward of the centrate opening. Of course, this arrangement is exemplary, and other methods and configurations may be used in other arrangements.

The exemplary single-use construction 178 also includes a flexible outer wall 222. The flexible outer wall 222 is a fluid tight wall that extends in operative supporting engagement with the walls defining the rigid drum cavity 176 in the operative position of the exemplary single use structure 178. In this exemplary arrangement, the flexible outer wall 222 is operatively engaged with the dished portion 194 in a fluid-tight connection. The flexible outer wall has an inner frustoconical shape with a smaller inner radius adjacent a lower portion of the single-use construction adjacent the second axial end 192.

The example flexible outer wall 222 extends in surrounding relation to at least a portion of the core 200. The wall 222 also defines an annular separation chamber 224. A separation chamber 224 extends radially between the outer wall of the core 200 and the flexible outer wall 222. The substantially annular concentrate opening 218 and the substantially annular centrate opening 210 are each in fluid communication with a separation chamber 224.

In this exemplary arrangement, the flexible outer wall 222 has a textured outer surface 226. The textured outer surface is configured to enable air to escape from the space between the surface defining the cavity of the rigid drum 172 and the flexible outer wall 222. In one exemplary arrangement, the textured outer surface may comprise substantially the entire area of the flexible outer wall in contact with the rigid drum. In an exemplary arrangement, the textured outer surface may include a pattern of one or more outwardly extending protrusions or dimples 228 with spaces or recesses therebetween to facilitate the passage of air. When the single-use configuration 178 is positioned in the drum cavity 176, air can be expelled therefrom through the upper opening 180 or through the lower opening 230. In an exemplary arrangement, the projections may be constructed of an elastically deformable material that may decrease in height in response to the force of the liner against the rigid wall of the drum. The textured outer surface 226 of the flexible outer wall 222 reduces the risk that air pockets will become trapped between the rigid bowl of the centrifuge and the single-use configuration. Such cavitation may cause irregularities in the wall profile, which may cause imbalances and/or alter the profile of the separation chamber in a manner that adversely affects the separation process. Of course, it should be understood that the air release structure is exemplary and other arrangements of other air release structures may be used.

The exemplary single-use configuration shown in fig. 21 also includes a rigid or semi-rigid lower disk-shaped portion 232. Rigid or semi-rigid materials operate to maintain their shape during operation. In this exemplary arrangement, the lower disc-shaped portion 232 has a tapered shape and is operatively attachedly connected with the lower end of the core 200 by a vertically extending wall or other structure. A plurality of angularly spaced fluid passages 234 extend between the upper surface of the disc portion 232 and a radially outwardly lower portion of the core. The fluid passage 232 extends radially outward and upward relative to the bottom of the second axial end 192 and enables cells in the cell culture batch material entering the interior region 186 through the opening 190 in the feed tube 184 to enter the separation chamber 224 radially outward and upward.

In this exemplary arrangement, the flexible outer wall 222 extends below the lower disc-shaped portion 232 at the second axial end 192 of the single-use configuration. The flexible outer wall 222 extends intermediate the lower disc portion 232 and a wall surface of the rigid drum 172 that defines a cavity in which the single-use configuration is positioned.

In this exemplary arrangement, the feed tube 184, centrate discharge tube 212 and concentrate discharge tube 220, as well as the centrate centrifugal pump 208 and concentrate centrifugal pump 216, remain stationary while the centrifuge bowl 172 and upper disc portion 194, lower disc portion 232 and flexible outer wall 222 rotate relative to the bowl. At least one annular resilient seal 236 operatively extends between the outer surface of the concentrate outlet conduit 220 and the upper disc shaped portion 194 in sealing engagement. The at least one seal 236 maintains a hermetic seal in a manner similar to that previously discussed such that air pockets may be maintained in the interior region 186 during cell processing to isolate the seal from the cell culture batch material being processed. The air pockets maintained within the interior region of the single-use configuration are configured such that the centrate centripetal pump 208 and the concentrate centripetal pump 216 remain in fluid communication with the cell culture batch material. In a manner similar to that previously discussed, a positive pressure may be maintained within the interior region to ensure that an air pocket exists to sufficiently isolate the at least one seal 236 from the cell culture batch material being processed. Alternatively, other methods may be used in order to keep the seal isolated from the material being processed.

The exemplary system 170 operates in a manner similar to that previously discussed. Cells in a cell culture batch material are introduced through the feed tube 184 into the interior region 186 of the single-use construction 178. Cells enter the interior region 186 through a feed tube opening 190 at the lower axial end of the single-use configuration. Centrifugal forces cause the cells to move outward through the opening 234 and into the separation chamber 224. The outwardly and upwardly tapered outer wall 222 causes cells or cellular material containing a cell concentrate to collect near the radially outward and upper region of the separation chamber 224. The typically cell-free centrate collects in the separation chamber, radially inwardly adjacent the outer wall of the core 200.

In this exemplary arrangement, the cytocentrate passes upwardly through a substantially annular centrate opening into a centrate pump chamber. The centrate passes inwardly through a substantially annular opening of the centrate radial pump and then upwardly through the centrate discharge tube 212. At the same time, the cell concentrate passes through the substantially annular concentrate opening 218 and into the concentrate centripetal chamber 214. The cell concentrate passes inwardly through a substantially annular opening of the concentrate centripetal pump 216 and then upwardly through the concentrate discharge tube 220. This exemplary configuration enables the exemplary system 170 to operate on a continuous or semi-continuous basis. Operation of the system 170 may be controlled in a manner similar to that discussed later to facilitate reliable extended operation of the system and delivery of the desired cell concentrate and generally cell-free centrate in a single output fluid stream.

Fig. 22 illustrates an alternative centrifuge system, generally designated 238. The system 238 has a single-use configuration 240. The single-use construction 240 is similar in most respects to the single-use construction 178 described previously. Some of the structures and features of the single-use structure 240 that are substantially identical to those described in connection with the single-use structure 178 are labeled with the same reference numerals as those used to describe the single-use structure 178.

The single-use construction 240 differs from the single-use construction 178 in that it includes a rigid or semi-rigid lower disk portion 242. The lower disc portion 242 is a generally conical structure operatively connected to the lower end of the core 200. A plurality of radially outwardly and upwardly extending fluid passages 244 extend between the lower end of the core 200 and the lower disk portion 242. The exemplary lower disk portion 242 also includes a plurality of angularly spaced radially extending vanes 246. The fluid passages extend radially outwardly between each angularly adjacent pair of vanes 246. In this exemplary arrangement, the vanes 246 extend upwardly from the bottom of the disc portion 242, and at least some of the vanes are operatively engaged with the core at a radially outer portion thereof. In this exemplary arrangement, the vanes 246 accelerate the cell culture batch to facilitate movement and separation within the interior region of the single-use configuration.

An alternative exemplary arrangement of a centrifuge system 248 is shown in fig. 23. This exemplary arrangement includes a single-use configuration 250. The single-use construction 250 is similar in many respects to the previously described single-use construction 178. Some structures and features similar to those in the single-use structure 178 described previously are labeled with the same reference numerals on the single-use structure 250.

The exemplary single-use construction 250 differs from the single-use construction 178 in that it includes a lower disc-shaped portion 252. The lower disk portion 252 is a rigid or semi-rigid conical structure that is operatively attached to the core 200 via a wall or other suitable structure. The lower disk portion 252 includes a plurality of angularly spaced radially outwardly extending accelerator blades 254. The accelerator blades 254 extend downward from the lower tapered side of the disk portion 252. Each angularly adjacent pair of vanes 254 has a fluid passage extending therebetween. In this exemplary arrangement, the flexible outer wall 222 extends in an intermediate relationship between the lower ends of the vanes 254 and the wall of the rigid drum 172 defining the cavity 176. This exemplary configuration provides a submerged accelerator operable to accelerate a cell culture batch material to facilitate its separation within an interior region of a single-use configuration. Of course, it should be understood that the single-use structural features described herein may be combined in different arrangements to facilitate separation of different types of materials and substances having different properties and achieve a desired output fluid flow.

Fig. 26 shows an alternative single-use configuration 304. The single-use configuration 304 is similar to the previously described single-use configuration 178, except as otherwise noted herein. Elements that are the same as elements in the single-use configuration 178 have been identified with the same reference numbers in fig. 26.

The single-use configuration 304 includes a continuous annular concentrate dam 306. A concentrate dam 306 extends downwardly in the separation chamber 224 and is disposed radially inward of the substantially annular concentrate opening 218. The example annular concentrate dam shown in cross-section extends downwardly below the concentrate opening, and the example annular concentrate dam shown in axial cross-section includes a tapered outer surface 308 extending outwardly and toward the opening 218.

Single-use configuration 304 also includes a continuous annular centrate dam 310. A centrate dam 310 extends downwardly below the substantially annular centrate opening 210 in the separation chamber 224. Centrate dams 310 are located radially outward from the centrate openings 210. In this exemplary arrangement, the downward distance that concentrate dam 306 and centrate dam 310 extend in separation chamber 224 is substantially the same. However, in other exemplary arrangements, other configurations may be used. Also, in other exemplary arrangements, the centrifuge structure may include a concentrate dam or a centrate dam, but not both.

An annular recess 312 extends radially in the separation chamber between the centrate dam and the centrate dam. The exemplary annular recess extends upwardly between the centrate and centrate dams so as to form an annular air pocket therebetween.

In an exemplary arrangement, the concentrate dam 306 helps ensure that primary cellular material or other solid material to be separated can pass outwardly along the upper portion bounding the separation chamber 224 to reach the concentrate opening 218 and concentrate centripetal chamber 214. The centrate dam 310 also helps ensure that predominantly cell-free centrate material is allowed to pass along the upper surface bounding the separation chamber 224 and into the substantially annular centrate opening 210 to reach the centrate pump chamber 206. It should be understood that a variety of different configurations of concentrate dams and centrate dams may be used in different example arrangements depending on the nature of the material being processed and the requirements for processing such material.

FIG. 24 is a schematic diagram of an exemplary control system for providing substantially continuous processing of cell culture material to produce a generally cell-free centrate stream and a cell concentrate stream. In this exemplary arrangement, the centrifuge system 170 previously discussed is shown. However, it should be understood that this example system feature may be used with many different types of materials and centrifuge systems and structures, such as those discussed herein.

In the exemplary arrangement shown, centrifuge bowl 172 is rotated at a selected speed about axis 174 by motor 256. Feed line 184 is operatively connected to cell culture feed line 258 through which cell culture batch material is received. The feed line is operatively connected to a feed pump 260. In an exemplary arrangement, the feed pump 260 can be a peristaltic pump or other suitable pump for delivering cell culture at a selected flow rate into a single-use configuration.

Centrate discharge line 212 is fluidly connected to centrate discharge line 262. A centrate optical density sensor 264 is operatively connected to an interior region of the centrate discharge line 262. In this exemplary arrangement, the centrate optical density sensor is an optical sensor operable to determine the density of cells currently in the centrate passing through the single use configuration. In this exemplary arrangement, this is achieved by measuring a decrease in intensity of light output by the emitter that is received by the receiver provided from the emitter and has at least a portion of the centrate stream passing therebetween. The amount of light from the emitter received by the receiver decreases as the density of cells in the centrate increases. Of course, this is only one example of a sensor that may be used to determine the density or amount of cells present in the centrate, and other types of sensors may be used in other arrangements. For example, the light may be near infrared light or other visible or invisible light. In other sensing arrangements, other forms of electromagnetic, acoustic, or other types of signals may be used for sensing. The centrate discharge line is also operatively connected to a centrate pump 266. In this exemplary arrangement, the centrate pump may comprise a peristaltic pump or other variable rate pump suitable for pumping centrate material.

In this exemplary arrangement, the concentrate drain 220 is operatively connected to the concentrate drain line 268. A concentrate optical density sensor 270 is operatively connected to at least a portion of the interior region of the concentrate discharge line 268. The exemplary concentrate optical density sensor may operate in a similar manner to the spin filter optical density sensor previously discussed. Of course, it should be understood that the concentrate optical density sensor may comprise different structures or properties, and that different types of cell density sensors may be used in other exemplary arrangements. The concentrate discharge line 268 is operatively connected to a concentrate pump 272. In this exemplary arrangement, the concentrate pump 272 may include a peristaltic pump or other variable rate pump suitable for pumping concentrate without causing damage thereto. Of course, it should be understood that these structures and components are exemplary and that alternative systems may include different or additional components.

The exemplary control system includes a control circuit 274, which is alternatively referred to herein as a controller. In an exemplary arrangement, the control circuitry may include one or more processors schematically indicated at 276. The control circuitry may also include one or more data memories schematically indicated at 278. The one or more data stores may include one or more types of tangible media that hold circuit-executable instructions and data that, when executed by a controller, cause the controller to perform operations such as those discussed later herein. Such a medium may include, for example, solid-state memory, magnetic memory, optical memory, or other suitable non-transitory medium for holding circuit-executable instructions and/or data. The control circuit may include structures similar to those previously discussed.

The operations performed by the exemplary controller 274 will now be described in connection with the schematic representation of a logic flow illustrated in FIG. 25. In this exemplary arrangement, the controller 274 is operable to control the operation of the components in the system so as to maintain the concurrent delivery of the output flow of the generally cell-free centrate and cell concentrate. This is accomplished by using optical density sensors in the respective centrate and centrate outlet lines to detect the cell density (or turbidity) of the output feed and adjust the operation of the system components to maintain the output within a desired range.

In using this exemplary control system, the cell concentration of the cells in the cell culture material to be processed is measured separately before operation of the system is initiated. The desired axial rotational speed of the centrifuge is determined as the speed for operating the feed pump 260. In this exemplary arrangement, the rotational speed of the centrifuge and the feed rate of cellular material through the feed pump are typically maintained by a controller at constant set points. Of course, in other arrangements and systems, alternative methods may be used, wherein the speed and feed rate may be adjusted by the controller during cell processing.

In this exemplary arrangement, the discharge rate (flow rate) of the external concentrate pump 272 is set at an initial value, referred to herein as the "primary value," based on the determined cell concentration. Also preset in this exemplary arrangement is a "priming duration" which corresponds to the period of time that the external concentrate pump 272 will initially operate at a priming value. This duration allows the single-use construction 178 to be partially filled. Also in this exemplary system, a "base speed" is set for the concentrate pump based on the cell density and the feed rate from the feed pump 260. The base speed of the concentrate pump is the speed (which corresponds to the flow rate) at which the concentrate pump will operate after the priming duration. In this exemplary arrangement, the set base speed is generally expected to correspond to a concentrate pump speed that will produce a centrate having a cell density below a desired set limit and a cell concentrate having a cell density generally above another desired set limit. The set point and limit values are received by the controller in response to input through a suitable input device and stored in the at least one data store.

In the exemplary logic flow illustrated in fig. 25, step 280 represents operation of the concentrate pump 272 at an initial priming rate. At step 282, it is determined by the controller whether the concentrate pump has been operating at the priming speed for a period of time corresponding to the priming duration, the period of time being operable to at least partially fill the single use configuration 178.

Once the concentrate pump has operated at the priming speed for the priming duration, the controller causes the concentrate pump speed to then increase to the base speed, as represented by step 284. The controller 274 operates to monitor the cell density in the centrate as detected by the sensor 264. The controller operates to determine if the optical density is above the desired set point, as shown in step 286. If the optical density of the centrate is not above the set point, the centrate is sufficiently free of cells or cellular material such that this measurement does not cause the controller to change the operating speed of the concentrate pump, and the logic returns to step 284.

If in step 286 it is determined that the optical density of the centrate is above the set point, the logic proceeds to step 288. In step 288, control operates to increase the speed of the concentrate pump by the set incremental step amount. This increase in velocity step is generally intended to result in a clearing of the optical density of the centrate by reducing the number of cells therein.

After increasing the speed of the concentrate pump 272 in step 288, the controller then operates in response to the sensor 264 to determine in step 290 whether the optical density of the centrate is still above the set point for a set time after the incremental increase in the speed (flow) of the concentrate pump. If so, the controller continues to monitor the optical density of the centrate until it is not above the set point. In this exemplary arrangement, the instructions include a set period of time during which the centrate optical density must not be above the set point before the concentrate pump speed controller determines that the adjustment to the base speed is sufficient to maintain the centrate optical density at a level at or below the desired set point. Step 292 represents the controller determining that the increased concentrate pump speed has maintained the optical density of the centrate at or below the set point of the stored set time period value corresponding to consistently producing a completely cell-free centrate outflow or achieving a programmed wait time. In response to producing a completely cell-free centrate for a desired duration or reaching a programmed wait time, the controller next operates in step 294 to cause the basal speed value of the concentrate pump to be adjusted to correspond to an increased basal speed. The controller sets a new base speed and the logic returns to step 284. It should be noted that if the centrate optical density is still above the set point as determined in step 286, the concentrate pump speed will be adjusted again.

The exemplary controller also simultaneously monitors the optical density of the cells in the output concentrate stream. This is done by monitoring the optical density as detected by sensor 270. The controller operates to determine if the optical density in the concentrate is below a desired set point, as shown in step 296. If the concentrate optical density is detected at or above the desired set point value stored in the data store, the concentration of cells in the concentrate output stream is at or above the desired level, and the logic returns to step 284. However, if the optical density of the concentrate is below the desired set point, meaning that the level of cells in the concentrate is below the desired level, the controller moves to step 298. In step 298, the speed of the concentrate pump is reduced by a predetermined incremental step amount. Reducing the speed of the concentrate pump will reduce the output flow rate, typically increasing the amount of cells in the concentrate output stream, and thus increasing the optical density of the concentrate output stream.

The controller then operates the concentrate pump 272 at the new reduced speed, as shown in step 300. As shown in step 302, the controller operates the concentrate pump at this reduced rate for a set period of time corresponding to the set point stored in the data storage device so that the concentration of cells in the output concentrate stream can be increased before determining whether the rate reduction is sufficient. Once it is determined in step 302 that the time period has elapsed, the controller returns to step 284 from which the logic flow is then repeated to determine whether further speed adjustments are needed.

Of course, it should be understood that this exemplary simplified logic flow is exemplary, and in other arrangements, different logic flows and/or additional operating parameters of system components may be monitored and adjusted to achieve the desired output flows of centrate and centrate. For example, in other exemplary arrangements, the speed of the centrate discharge pump, and thus the centrate discharge flow rate, may be varied by the controller at least partially in response to the optical density corresponding to the level of cells in the centrate detected by the centrate optical density sensor. For example, if the cell level in the centrate is detected to be above a set limit, the controller may operate to reduce the centrate pump flow rate. This may be done by the controller instead of or in combination with controlling the concentrate discharge flow rate. The controller can vary the centrate flow rate as appropriate to ensure that the cell levels in the centrate remain below set limits or within set ranges.

Alternatively or additionally, the controller may also control the flow rate of the cell suspension into the single-use configuration. This can be done in conjunction with varying the flow rates of the centrate and centrate from the single-use configuration to maintain the cell levels in the centrate and centrate within programmed set limits stored in a memory associated with the controller. In addition, the controller may also operate in accordance with its programming to vary other process parameters, such as changes in the rotational speed of the drum, introduction of diluent and diluent introduction rate, as well as other process parameters, to maintain the centrate and concentrate properties within programmed limits and desired process rates. Further, in other exemplary arrangements, other properties or parameters may be monitored and adjusted by the control system in order to achieve a desired product.

Fig. 27 shows a cross-sectional view of another alternative single-use centrifuge structure 314. The single-use configuration 314 is generally similar to the single-use configuration 178 previously discussed, except as specifically noted. Single-use arrangement 314 includes elements operable to help ensure that the air/liquid interface of the air pocket extending in the single-use arrangement and isolating seal 236 from the material being processed is more stably maintained at a desired radial position.

In the single-use configuration 314, the centrate pump 208 is positioned in the centrate pump chamber 316. The centrate pump chamber 316 is vertically bounded at the bottom by a circular lower centrate to the centrate pump chamber surface 318. The centrate pump chamber 316 is vertically bounded on the upper side by a circular upper centrate towards the centrifuge chamber surface 320.

Lower centrate pump chamber surface 318 extends radially outward from lower centrate pump chamber opening 322. In this exemplary arrangement, the lower centrate pumping chamber opening 322 extends through the circular top of the core 200 and corresponds to the upper opening 202 previously discussed. Feed tube 184 extends through the lower centrate opening to the centripetal chamber.

The upper centrate pumping chamber surface 320 extends radially outward from a circular upper centrate pumping chamber opening 324. The feed tube 184 and centrate discharge tube 212 extend axially through the upper centrate opening to the centrifuge chamber.

A plurality of angularly spaced, upwardly extending lower centrate chamber vanes 326 extend across the lower centrate centripetal pumping chamber surface 318. Each lower centrate chamber blade 326 extends radially outward from the lower centrate chamber opening 322. The lower centrate chamber blades 326, shown in greater detail in fig. 28, extend radially outward from the rotational axis 174 by a lower centrate blade distance V. In this exemplary arrangement, lower centrate chamber vanes 326 extend upwardly in circular recesses on the lower centrate centripetal pump chamber surface 318. However, it should be understood that this arrangement is exemplary and that other arrangements may be used; for example, the radial length of the vanes, the vane height, and the depth and diameter of the recess may be varied to achieve desired fluid pressure properties.

A plurality of angularly spaced, downwardly extending upper centrate chamber vanes 328 extend from the upper centrate toward the pumping chamber surface 320. Each of the upper centrate chamber vanes 328 extends radially outward from the upper centrate centripetal pump chamber opening 324. The upper centrate chamber blades extend an upper centrate blade distance radially outward from the rotational axis 174. In this exemplary arrangement, the upper centrate blade distance substantially corresponds to the lower centrate blade distance V. In this exemplary arrangement, the upper centrate chamber blades extend downwardly in a circular recess on the upper centrate centripetal chamber surface, the circular recess having a similar configuration to that shown in figure 28 for the lower centrate chamber blades, but in the opposite orientation.

In the exemplary arrangement shown, centrate radial pump 208 includes a substantially annular centrate radial pump opening 330. The substantially annular centrate pump opening distance is provided radially outward of the centrate pump opening 330 from the axis of rotation 174. For reasons discussed later, the centrate pump opening distance at which the centrate feed openings 330 are located is a greater radial distance than the lower centrate blade distance and the upper centrate blade distance.

In the exemplary arrangement of the single-use configuration 314, the concentrate centripetal pump 216 is positioned in the concentrate pump chamber 332. The concentrate pump chamber 332 is vertically bounded on the underside by a circular lower concentrate to a pump chamber surface 334. The concentrate pump chamber 332 is vertically bounded on the upper side by a circular upper concentrate to a pump chamber surface 336.

The lower concentrate pumping chamber surface 334 extends radially outward from the lower concentrate pumping chamber opening 338. In this exemplary arrangement, the lower concentrate centripetal chamber opening corresponds in size to and is continuous with the upper concentrate centripetal chamber opening 324. The feed tube 184 and centrate discharge tube 212 extend through the lower concentrate centripetal chamber opening 338.

A plurality of angularly spaced upwardly extending lower concentrate chamber vanes 340 extend over the lower concentrate centripetal chamber surface 334. The lower concentrate chamber vanes 334 extend radially outward from the lower concentrate toward the pumping chamber opening 338. The lower concentrate compartment blades 334 extend radially outward from the axis of rotation by a lower concentrate blade distance. In this exemplary arrangement, the lower concentrate compartment vanes 334 extend over a circular recess of the lower concentrate centripetal pumping chamber surface, similar to the upper and lower concentrate compartment vanes previously discussed. Of course, it should be understood that this configuration is exemplary.

The upper concentrate extends radially outward from the upper concentrate towards the pumping chamber surface 336 towards the pumping chamber opening 342. The feed pipe 184, the centrate discharge pipe 212 and the concentrate discharge pipe 220 extend coaxially through the upper concentrate centripetal pump chamber opening 342. A plurality of angularly spaced upper concentrate compartment vanes 344 extend downwardly from the surface 336. The upper concentrate chamber vanes extend radially outward from the upper concentrate toward the pumping chamber opening 342 by an upper concentrate vane distance. The upper concentrate chamber vanes extend in upwardly extending circular recesses in the upper concentrate centripetal pump chamber surface. In this exemplary arrangement, the upper concentrate compartment blade is constructed in a similar manner to the lower concentrate compartment blade and the upper and lower centrate compartment blades discussed previously. Of course, it should be understood that this method is exemplary, and that other methods may be used in other arrangements.

The concentrate centripetal pump 216 includes a substantially annular concentrate pump opening 346. The concentrate pump opening is radially disposed from the rotational axis 174 by a concentrate pump opening distance. In this exemplary arrangement, the upper and lower concentrate vane distances are less than the concentrate pump opening distance. Of course, it should be understood that this configuration is exemplary and that other methods may be used in other arrangements.

In the exemplary single-use configuration 314, the upper and lower concentrate compartment vanes 344, 340, and the upper and lower centrate compartment vanes 326, 328 operate to stably and radially position the annular air/liquid interface 348 in the centrate pump chamber 330 and the air/liquid interface 350 in the concentrate pump chamber 332. As shown in fig. 28, the air/liquid interface 348 is positioned radially midway along the radial length of the centrate chamber blades. This is radially inward from the centrate pump opening 330. The radially extending centrate chamber vanes operate to provide a centrifugal pumping force that maintains the annular air/liquid interface 348 at radial positions above and below the centrate pump, which are disposed radially inward of the centrate pump openings 330. In this exemplary arrangement, the vanes further help stabilize the air/liquid interface so that it remains in a coaxial circular configuration both above and below the centrate pump. Further, in an exemplary arrangement, the radial position of the interface relative to the axis of rotation may be controlled as discussed later such that the centrate pump opening 330 remains in the liquid centrate at all times and is not exposed to air.

The upper concentrate compartment blades 344 and the lower concentrate compartment blades 340 operate in a similar manner as the centrifuge filter compartment blades. The concentrate chamber vanes maintain a circular air/liquid interface 350 in the concentrate pump chamber 332 at a radial distance inside the substantially annular concentrate pump opening 346. This configuration ensures that the concentrate pump opening is always exposed to concentrate rather than air. It will also be appreciated that although the centrate and concentrate radial pumps are of substantially the same size in the arrangement shown, other arrangements of radial pumps may be of different sizes. In this case, the radial distance from the axis of rotation in which the centrifuge chamber vanes and the concentrate chamber vanes extend may be different. Also, the radial position of the air/liquid interface in the centrate and centrate pump chambers with respect to the rotational axis may be different. A variety of different blade configurations and arrangements may be used depending on the particular relationship between the components making up the single-use set and the particular materials being handled via the single-use configuration.

Figure 30 shows an upper portion of another alternative single-use construction 352. Single-use configuration 352 is similar to single-use configuration 304, except as discussed otherwise. The single-use arrangement 352 includes an air tube 354 that extends in coaxially surrounding relation to the concentrate discharge tube 220. The air tube 354 communicates with an opening 356 in the single-use configuration. The opening 356 extends from the interior of the air tube to above the concentrate centripetal pump 216 in the concentrate pump chamber 332. In this exemplary arrangement, the seal 236, as schematically shown, operatively engages the air tube 354 to maintain airtight engagement with the air tube and the concentrate discharge tube, centrate discharge tube and feed tube. As can be appreciated, the air tube may be used to selectively maintain the air pressure level in the air pocket within the single-use configuration. This arrangement may be used in conjunction with the system described previously, or in other systems where an externally supplied pressurized air is used to isolate the seals of the centrifuge structure from the material being processed and to maintain the air/liquid interface in a desired position. Of course, it should be understood that this structure is exemplary and that other methods may be used in other arrangements.

FIG. 31 schematically illustrates a system 358 that may be used to continuously separate a cell suspension into a substantially cell-free centrate and concentrate. The system 358 is similar to the system 170 previously discussed, except as otherwise noted herein. In this exemplary arrangement, the system 358 operates using a single-use configuration similar to the single-use configuration 352. The controller 274 of the system 358 operates to control the position of the air/liquid interface within the single-use configuration to ensure that the interface is maintained radially inward from each of the centrate and centrate pump openings with respect to the axis of rotation.

In this exemplary arrangement, a flow back pressure regulator 360 is fluidly connected to the centrate discharge line 262. In this exemplary arrangement, flow back pressure regulator 360 is intermediate the centrate discharge tube 212 and the fluid of centrate pump 266. The exemplary system 358 includes a source of pressurized air schematically represented at 362. A source of pressurized air 362 is connected to a pilot pressure control valve 364. The control valve is operatively connected to a controller 274. The signal from the controller 274 causes a selectively variable pressure in the pilot line 366. The pilot line 366 is fluidly connected to the back pressure regulator 360. The pressure applied in the pilot line 366 by the pilot pressure control valve 264 is operable to control the centrate flow and, thus, the centrate flow backpressure applied by the flow backpressure regulator 360.

In the exemplary arrangement, a pressure control valve 368 is in fluid communication with the pressurized air source 362. Control valve 368 is also operatively connected to controller 274. In this exemplary arrangement, the control valve 368 is controlled to selectively apply precise pressure to the air tube 354 and the air pocket in the upper portion of the single-use configuration 352.

In this exemplary arrangement, the controller 274 operates in accordance with stored executable instructions to control the operation of the system 358 in a manner similar to that previously discussed in connection with the system 170. Further, in the exemplary arrangement, controller 274 operates to control pilot pressure valve 364 to vary the back pressure applied by back pressure regulator 360 to centrate discharge tube 212. Controller 274 also operates to control valve 368. The controller operates to maintain and selectively vary the pressure applied in the air pocket at the top of the interior of the single-use construction. The controller operates according to its programming to vary the backpressure and/or cavitation pressure of the centrate stream to maintain the air/liquid interface of the cavitation at a radial distance from the axis of rotation, inward from the centrate pump opening 330 and the centrate pump opening 346. This pressure change in both the centrate flow back pressure and the cavitation pressure, combined with the effect of the centrate chamber blades and the concentrate chamber blades in this exemplary arrangement, maintains the stability and radial outward extent of the air/liquid interface so as to ensure that air induction in the centrate and concentrate output from the single use configuration is minimized. In addition, the ability to selectively vary the backpressure and flow rate of the centrate may affect the level of cells and the corresponding detected optical density of the discharged concentrate. Thus, the controller may operate in accordance with its programming to selectively vary the concentrate flow rate, the centrate back pressure and flow rate, the internal air pocket pressure, the feed rate of the cell suspension into the single use configuration, and possibly other operating variables of the centrifugation process to maintain the centrate and concentrate properties within set limits and/or ranges stored in at least one data store associated with the controller. Furthermore, this exemplary arrangement may enable different types of materials to be separated and operated at different flow rates while maintaining reliable control of the separation process. Of course, while it should be understood that control of the position of the air/liquid interface is described in connection with the features of the system 170, such control may be used in other types of systems including other or different types of processing elements.

Fig. 32-34 illustrate yet another alternative single-use configuration 370. The exemplary single-use construction 370 includes many features similar to those discussed in connection with the previously described single- use constructions 178, 240, and 250, for example. It should be understood that the additional features discussed herein in connection with other single-use configurations may also be used in arrangements having the features and relationships shown in the single-use configuration 370.

The single-use construction 370 includes an upper dished portion 372. The exemplary upper disk-shaped portion 372 includes a centrate centripetal pumping chamber 374 therein. Centrate radial pump 208 is housed within centrate radial pump chamber 374. The centrate radial pump chamber has a centrate chamber volume within the upper disc portion.

The centrate centripetal pumping chamber is in fluid communication with the separation chamber through at least one centrate passage 410. The centrate channel 410 is fluidly connected to at least one centrate channel inlet 412. The example at least one centrate channel inlet 412 is in fluid communication with the separation chamber immediately radially outward of the cylindrical wall of the cylindrical core. In the exemplary arrangement shown, the at least one centrate channel inlet 412 is a single substantially annular inlet and the centrate channel is a single substantially annular channel.

The upper disk portion also includes a concentrate centripetal pumping chamber 376. The exemplary concentrate centripetal chamber 376 is a cylindrical chamber horizontally bounded by a vertically extending circular bounding wall 378. The concentrate centripetal pump chamber 376 has a concentrate chamber volume within the upper disc portion. In an exemplary arrangement, the centrate chamber volume within the upper disc-shaped portion is greater than the concentrate chamber volume for reasons discussed later.

The exemplary upper disk shaped portion includes an upper member 394 and a lower member 396. In an exemplary arrangement, the upper and lower components are held together in releasable engagement. Of course, this approach is exemplary, and other approaches may be used in other arrangements. The exemplary lower member 396 in the operative position is bounded at its upper side by an upper annular bounding surface 398. The exemplary lower member 396 is bounded at its underside by a lower annular bounding surface 400. The upper annular defining surface 398 includes a radially outwardly tapered annular upper surface portion 402 and a radially inwardly radially planar extending upper surface portion 404. The lower annular defining surface 398 includes a radially outwardly tapered annular lower surface portion 406 and a radially inwardly radially planar extending lower surface portion 408. In the operative position of the upper member 394 and the lower member 396, the lower surface 408 extending horizontally by the radially inward radial plane and the upper surface 404 extending horizontally by the radially inward radial plane extend parallel to each other. However, the tapered annular upper surface portion 402 and the tapered annular lower surface portion in the operating position are not in a parallel relationship for reasons discussed later.

In the exemplary arrangement, a substantially annular cell concentrate passage 380 extends between the upper member 394 and the lower member 396 of the upper disk portion 372. The annular cell concentrate channel 380 extends radially inward from a substantially annular cell concentrate channel inlet 382. The concentrate passage inlet is disposed further radially outward from the centrate inlet 412. The concentrate channel inlet 382 is positioned in fluid connection with the upper region of the separation chamber 224 at a radially outer periphery adjacent the inner surface of the outer wall where the cell concentrate 384 collects in an annular radially outward region 384 of the separation chamber during rotation of the device with the centrifuge bowl, as shown in fig. 34.

In the exemplary arrangement, the substantially annular funnel channel 381 extends upwardly and radially inwardly to the annular cell concentrate channel inlet 382. The lower part 396 of the exemplary upper disc-shaped portion 372 in the operating position is delimited in the separation chamber at the lower radially inward side by a substantially planar radially extending surface 379. The exemplary radially extending surface 379 terminates radially outward at the annular edge 377. In the operative position of the single use configuration, annular funnel channel 381 extends upwardly from annular edge 377. The example upper component 394 of the example annular disk portion 372 also includes a substantially annular cell concentrate guide surface 383. The annular cell concentrate guide surface 383 extends below the annular funnel channel 381 and delimits the separation chamber 224 radially outward at the axial level of the radially extending planar surface 379. In this exemplary arrangement, the annular cell concentrate guide surface 383 extends further radially outward and upward to access the funnel channel.

In this exemplary arrangement, the annular cell concentrate channel 380 terminates radially inwardly in the concentrate centripetal chamber 376 at a substantially annular cell concentrate outlet 386. In the exemplary arrangement, the annular cell concentrate outlet 386 is positioned to extend at a midpoint of the vertically extending bounding wall 378. In this exemplary arrangement, the concentrate centripetal pump includes a substantially annular concentrate centripetal pump inlet 388. The annular cell concentrate outlet of channel 380 is in radially and axially aligned relationship with the concentrate towards the centripetal pump inlet 388.

In an exemplary arrangement, the annular cell concentrate channel includes a tapered portion 390 and a radially extending portion 392 in axial cross-section. The radially extending portion 392 extends directly radially outwardly between the radially planar extending upper surface portion 404 of the lower member 396 and the radially planar extending lower surface portion 408 of the upper member 394. The example radial extension 392 extends further directly radially outward from the annular cell concentrate outlet 386. In the operating position of the single-use configuration, the horizontal and radially extending portion 392 of the annular cell concentrate channel has a constant channel height, where the height of the channel refers to the dimension of the channel transverse to the direction of concentrate flow in the respective region of the channel. As a result, the horizontal and radially extending portion has a constant cross-sectional area over its entire length. In this exemplary arrangement, the horizontal and radial extensions 392 are axially and radially aligned and have the same height in axial cross-section as the inlet of the concentrate radial pump.

The tapered portion 390 of the annular cell concentrate passage 380 extends between the tapered annular upper surface portion 402 of the lower member and the tapered annular lower surface portion 406 of the upper member. The annular cell concentrate channel 380 is configured to have a channel portion with a channel height (and cross-sectional channel area) that increases continuously from the cell concentrate passage inlet 382 to the location where the tapered portion fluidly connects with the radially extending portion 392. This configuration causes the cross-sectional area of the channel section 390 perpendicular to the direction of concentrate flow within the channel section to increase with increasing proximity to the axis of rotation. The gradually continuously increasing cross-sectional area of the concentrate channels means that the cross-sectional area of the channels perpendicular to the flow direction of the concentrate steadily increases in the channel section, whereas there is no position in the channel section where the cross-sectional area of the channels undergoes an immediate change of more than 10% in cross-sectional area forming any discrete step.

In an exemplary arrangement, the continuously increasing height of the channel within the tapered portion 390 as proximity to the axis of rotation of the single use system increases helps to maintain a suitably high fluid velocity of the cell concentrate. In an exemplary arrangement, the annular cell concentrate channel has a configuration that avoids pressure drop zones to maintain a suitably high radially inward velocity of the components of the cell concentrate from the channel inlet 382 to the channel outlet 386.

In the exemplary arrangement, the annular inlet 382 to the annular channel 380 is the portion of the channel that is narrowest in axial cross-section in the elevation direction and smallest in cross-sectional area. At the annular inlet 382, the cells and the liquid in which the cells are suspended begin to flow radially inward. In this region of the single-use configuration, cells that are denser than the liquid are subjected to centrifugal acceleration forces directed radially outward due to centrifugal rotation. During operation of the exemplary arrangement, an external concentrate pump (such as the concentrate pump 272 previously discussed) is operated to maintain a flow rate such that the average velocity of the radially inward liquid flow at the annular channel inlet 382 is higher than the sedimentation velocity, and to maintain a force on the radially outward oriented cells that is caused by the centrifugal force acting on the concentrate at the channel inlet. Furthermore, in some exemplary arrangements, the upwardly tapered configuration of the tapered portion 390 is such that the component of the settling force opposing cell flow at the channel entrance and in the channel portion is less than the component opposing cell movement in the channel directly radially inward at the same radial position.

In an exemplary arrangement, the height of the annular tapered portion of the annular concentrate passage increases as the radial distance from the axis of rotation of the single-use construction decreases. In an axial cross-section of an exemplary configuration of the channels, the channel height of the tapered portion 390, and thus the cross-sectional area perpendicular to the concentrate flow direction, gradually and continuously increases as one approaches the axis of rotation of the single-use construction (the radial distance therefrom decreases). The exemplary configuration of the channels gradually and continuously increasing in height as a function of decreasing radial distance from the axis enables cells in the cell concentrate to continuously move radially inwardly through the concentrate channels at a suitably high velocity with the liquid in which the cells are suspended. Since the radially outwardly directed centrifugal acceleration forces acting on the cells are reduced with a corresponding reduction in radial distance from the axis of rotation, the cell concentrate is able to maintain the proper radially inward velocity throughout the course of traveling radially inward from the channel inlet 382 despite the increase in channel height. Thus, in the exemplary arrangement, as the cell concentrate moves radially inward from the annular inlet 382 toward the cell concentrate outlet 386 and into and through the concentrate centripetal chamber 376, the cell concentrate maintains a suitably high radially inward velocity throughout the channel portion 390 in the channel 380.

It should be understood that while in the exemplary arrangement shown in fig. 32-34, the channel portion including a progressively continuously increasing cross-sectional area begins at the channel inlet, other methods and configurations may be used in other arrangements. For example, in some alternative arrangements, channel portions having this configuration may be provided at other locations. Such location may depend on the particular configuration of the concentrate channel and the requirements in particular portions of the channel to achieve a sufficiently high flow rate of the concentrate to help move the concentrate and cells therein in a desired manner to overcome settling or other forces opposing the desired flow. Furthermore, it should be understood that while only a single annular concentrate passage portion having a progressively continuously increasing cross-sectional area is present in this exemplary arrangement, other arrangements may include other passages, such as multiple concentrate passages. It will be appreciated that the arrangement shown in fig. 32 to 34 is exemplary and that other arrangements may be used.

In the exemplary arrangement, the concentrate discharge tube 220 is operatively fluidly connected with an external concentrate pump as previously discussed. In an exemplary arrangement, the concentrate pump can operate in a system similar to the system 170 previously described, or in other systems responsive to control circuitry, to provide an outlet flow of cell concentrate while maintaining a suitable back pressure in the concentrate drain. Of course, it should be understood that many other types of components may be included in a system that operates the single-use architecture 370 to achieve the operational capabilities described herein.

In operation of the exemplary system, single-use structure 370 is rotated in operative connection with a centrifuge bowl to separate a cell suspension in an interior region of the structure. The cell suspension is separated into a cell isolate substantially free of cells and a cell concentrate enriched in cells in a manner similar to that previously discussed. In the exemplary arrangement, centrifugation creates an annular cell concentrate region 384 at the upper radially outer periphery of the separation chamber. The exemplary annular cell concentrate region remains in fluid connection with the annular channel inlet 382 and in contacting relation with the substantially annular cell concentrate guide surface and the annular funnel channel along which the cell concentrate moves towards the channel inlet 382.

In some exemplary arrangements, the configuration of the annular cell concentrate guide surface 383, which defines the radially outer periphery of the radially extending surface 379 of the separation chamber adjacent the upper disc-shaped portion, can operate to push cell concentrate upwardly into the annular funnel channel 381. This may be due to the configuration of the guide surface extending further radially outward and upwardly close to the final passage. Cell concentrate pushed radially outward against the annular cell concentrate guide surface 383 by centrifugal force generated by rotation of the centrifuge can move in engagement with the guide surface into the annular funnel channel which guides the cell concentrate upward and radially inward to the annular cell concentrate inlet. As the cell concentrate is directed radially upwards towards the channel inlet 382 by an annular converging surface that is an axial cross-section defining an annular funnel channel, the radially inward velocity of the liquid component of the cell concentrate increases with decreasing area of the funnel channel. As previously discussed, the exemplary configuration has a minimum height dimension (and minimum cross-sectional area) configured to produce the highest fluid velocity of the liquid phase of the cell concentrate at the annular channel inlet 382.

In the exemplary arrangement and method of operation thereof, the external concentrate pump is operable to generate a flow such that the cell concentrate in the annular cell concentrate passage 380 continuously moves from the cell concentrate annular inlet 382 to the cell concentrate annular outlet 386 at a flow rate that produces an average velocity of the liquid phase of the cell concentrate radially inward that is higher than the settling velocity of the cells. In an exemplary arrangement, achieving such a consistently high average velocity of the liquid phase in the cell concentrate over the height of the passage and the entire radial length of the passage helps to ensure that the cell concentrate and the cells therein move properly through the annular cell concentrate channel. Furthermore, in the exemplary arrangement, the gradually continuously increasing cross-section of the tapered portion 390 of the channel, the constant height of the radially extending portion 392, and the relatively small cross-sectional area, which is generally constant throughout the length of the annular cell concentrate channel, avoid regions of significant pressure drop along the length of the channel such that the velocity of the liquid phase and cells maintains sufficiently high continuity throughout the channel.

Further, in operation of the exemplary arrangement, the cell concentrate entering the concentrate centripetal chamber 376 can be moved at a sufficiently high velocity and flow rate to ensure that the liquid and cellular phases of the cell concentrate pass radially inward through the inlet of the concentrate centripetal chamber. In an exemplary arrangement, this result is facilitated by the volume and configuration of the concentrate centripetal pumping chamber and the configuration of the passage outlet 386 relative to the centripetal pumping inlet 388 of the centripetal pump 216.

These features of the example arrangement facilitate radially inward flow of cell concentrate in the example single-use configuration and enable beneficial operation of the single-use configuration and associated system. Of course, it should be understood that these features and configurations are exemplary, and that the principles described herein may be utilized in conjunction with other configurations and other single-use or multi-use configurations to achieve desired performance characteristics and cell separation in other centrifugation processes.

Fig. 35-38 illustrate yet another alternative arrangement of the single-use construction 414. This exemplary alternative single-use configuration includes many of the features of the foregoing arrangement. The exemplary single-use configuration includes an upper disk-shaped portion 416. The outer wall 418 is configured to be operatively connected with a centrifuge bowl within which the single-use construction 414 is configured to be positioned. The structure includes a lower portion 420 of the wall 418. The exemplary single-use configuration shown in fig. 36 has an interior region that is frustoconical and a smaller inside radius adjacent lower portion 420.

Similar to the arrangement previously described, the single-use structure 414 includes a cylindrical core 422. A cylindrical core 422 extends axially between upper and lower portions of the interior region of the structure. The core includes a cylindrical outer bounding wall 424. It should be understood that although the core 422 is shown in fig. 36 as a solid structure, a hollow core structure may be used in other arrangements. In the exemplary arrangement, a cylindrical core 422 extends in an interior region between the bottom of the upper disc-shaped portion and a plurality of upwardly-oriented, angularly-spaced vanes 426. The vanes 426 include fluid passages therebetween that extend upwardly from the inside of the walls that define the lower portion of the interior region of the single-use construction.

In an exemplary arrangement, the single-use construction 414 is configured to be rotatable about an axis 428 in a centrifuge bowl. The single-use structure, when in the operating position, further includes a vertically extending feed tube 430 configured to receive cell culture material into the interior region of the structure. The exemplary feed tube 430 extends down to a tube opening 432 in the lower portion of the single-use configuration and into the area where the incoming material to be separated into cell centrate and cell concentrate is introduced. In the exemplary arrangement shown, the feed tube 430 extends axially through a cylindrical opening 434 in the core.

The exemplary single-use configuration also includes a vertically extending centrate discharge tube 436 when in the operational position. A vertically extending centrate discharge tube 436 is fluidly connected to a centrate centripetal pump 438. The centrate radial pump is positioned in the centrate radial pump chamber 440 located in the upper disc portion 416. The centrate centripetal pump chamber 440 is fluidly connected to a separation chamber 442 that extends radially between the outer wall of the core 422 and the wall defining the interior region of the single-use configuration. The centrate centripetal pumping chamber is fluidly connected to the separation chamber 442 by at least one centrate channel inlet 444 and at least one centrate channel 446. In an exemplary arrangement, at least one centrate channel inlet 444 is positioned in the separation chamber radially outward of but radially in close proximity to the cylindrical wall bounding the core 422. In an exemplary arrangement, the centrate passage inlet has an arcuate shape. Further, in an exemplary arrangement of operating positions, centrate centripetal pump chamber 440 includes horizontally extending upper and lower centrate pump chamber surfaces, which may include upper and lower centrate pump chamber vanes, such as vanes 326 and 328 previously discussed.

The exemplary single-use construction 414 also includes a vertically extending concentrate discharge tube 448 in an operating position. As in the other described arrangements, the concentrate discharge tube 448, centrate discharge tube 436 and feed tube 430 are coaxially arranged on a single-use structure. A concentrate discharge 448 is fluidly connected to the concentrate centripetal pump 450. The concentrate centripetal pump 450 is positioned in a concentrate centripetal pump chamber 452 within the upper disc portion 416. In an exemplary arrangement, the concentrate pumping chamber is defined by respective upper and lower concentrate pumping chamber surfaces, each of which may comprise radially extending chamber vanes similar to those previously discussed.

In this exemplary arrangement, the concentrate centripetal chamber is fluidly connected to the separation chamber by a plurality of radially extending concentrate channels 454. In an exemplary arrangement, each concentrate passage extends within the upper disc portion and is angularly spaced from each of the other passages. The exemplary upper disk portion 416 includes an upper member 456 and a lower member 458. The exemplary upper disk portion also includes a bottom piece 460. In the exemplary arrangement in the operating state, each of the upper member 456, lower member 458, and bottom member 460 are in a sandwich engaging relationship. Each of the plurality of concentrate passages in the operating position is defined by at least one downwardly facing surface of the upper member 456 and at least one upwardly facing surface of the lower member 458.

As shown in fig. 36, each of the plurality of concentrate channels 454 includes a concentrate channel inlet 462. In an exemplary arrangement, the concentrate passage inlets have a smallest cross-sectional area throughout the respective concentrate passage in a direction perpendicular to the direction of concentrate flow. Each concentrate passage inlet 462 is fluidly connected to the outer periphery of the separation chamber by a vertical opening 464 extending in the upper disc-shaped portion. In the exemplary arrangement, each concentrate passage 454 is fluidly connected to the separation chamber by a respective vertical opening 464 that extends through the base member 460 and is defined between and by the upper and lower members 456, 458. In the exemplary arrangement, each respective vertical opening 464 comprises an arcuate elongated slot in the base member 460. Of course, it should be understood that this configuration is exemplary and that other approaches may be used in other arrangements.

In the exemplary arrangement, each concentrate channel has a substantially constant cross-sectional width from the channel inlet 462 to a respective opening from the channel into the concentrate centripetal chamber. Each concentrate channel comprises a channel portion having a gradually and continuously increasing cross-sectional area perpendicular to the concentrate flow direction in the respective concentrate channel portion. The cross-sectional area increases with increasing proximity of the location in the corresponding channel portion to the axis of the single-use construction. In an exemplary arrangement, each of the plurality of concentrate channels is configured such that a cross-sectional area perpendicular to the direction of concentrate flow in the tapered portion 468 gradually and continuously increases due to the varying height of the channels in the tapered portion. The height of each channel increases with increasing proximity to the axis of rotation. Of course, it should be understood that this arrangement is exemplary and that other methods may be used in other arrangements.

In the exemplary arrangement, each channel portion having a progressively continuously increasing cross-sectional area configuration begins at a respective concentrate channel inlet 462 and continues through a tapered portion 468 extending upwardly and radially inwardly from the concentrate channel inlet. Each tapered portion 468 fluidly connects to a horizontal and radially extending portion 470 of a respective concentrate passage 454. In the exemplary arrangement, each horizontal and radially extending portion of the respective concentrate passage extends from the tapered portion 468 to the concentrate centripetal chamber 450. In an exemplary arrangement, the horizontal and radially extending portion of the concentrate passage has a constant cross-sectional area, perpendicular to the direction of flow of the concentrate, radially inwardly from the tapered portion to the concentrate centripetal chamber. However, it should be understood that this arrangement is exemplary and that other approaches may be used in other arrangements.

In operation of the exemplary single-use construction 414, the upper disk-shaped portion 416, wall 418, and core rotate in operative connection with the centrifuge bowl. The feed line 430, centrate discharge line 436 and concentrate discharge line 448 are held stationary along with the concentrate centrifugal pump 450 and centrate centrifugal pump 438. In an exemplary arrangement, the cell culture material is separated into cell centrate and cell centrate in separation chamber 442 by centrifugal forces generated by rotation. The cell concentrate collects in the upper radially outer region of the separation chamber 442, while the substantially cell-free centrate collects in the region of the separation chamber proximate the cylindrical outer wall of the core.

Centrate passes through a plurality of centrate channel inlets 444 into the centrate pumping chamber and is removed from the centripetal pumping chamber by the centrate pumping chamber 438 and a centrate discharge tube. An external concentrate pump, as previously discussed, is operatively connected to the concentrate discharge tube and causes a flow of concentrate from the separation chamber of the single-use configuration. This flow of concentrate causes the cell concentrate to pass upwardly through each vertical opening 464 and to each respective concentrate channel inlet 462 where the relatively small cross-sectional area of the concentrate channel inlet causes the cell concentrate to have a high flow rate. The high flow rate operation of the cells of the liquid and cell concentrate applies a force to the cells contained in the cell concentrate to urge the cells to move in the upwardly and radially inwardly tapered portions 468 by overcoming the radially outwardly directed force acting on the cells in a manner similar to that discussed in connection with the prior arrangements.

The cross-sectional area perpendicular to the concentrate flow direction of the upwardly and radially inwardly extending tapered portion gradually and continuously increases. This progressively continuously increasing cross-sectional area keeps the flow rate of the concentrate sufficiently high at each radial position throughout the channel section to ensure that the cell concentrate continues to move towards the concentrating chamber at a suitably high rate despite the radially outward force at each position in the channel section. In an exemplary arrangement, the cell concentrate exits the tapered portions of the concentrate channels and passes through the horizontal and radially extending portion of each respective channel to reach the concentrate centripetal chamber 452, through which the cell concentrate is maintained at a suitably high velocity. As a result, the exemplary arrangement can provide flow characteristics to the cell concentrate that facilitate the flow of the cell concentrate within a single-use configuration and aid in the process of cell separation. Of course, as can be appreciated, the configuration of the single-use structure 414 is exemplary, and other configurations may be used in other arrangements.

In some exemplary arrangements, the upper, lower and bottom pieces of the upper disc shaped portion 416 may be releasably engaged. This may facilitate manufacturing and may enable inspection, cleaning or other purposes. In other exemplary arrangements, these components may be permanently joined. In other exemplary arrangements, structures similar to those described may be formed from other components that provide the useful characteristics and capabilities already discussed herein. Further, it should be understood that the configuration of the single use configuration 414 is exemplary, and that the useful principles and structures described herein may be used in other separator configuration arrangements.

Accordingly, the new centrifuge system and method of this exemplary arrangement achieves at least some of the above objectives, eliminates difficulties encountered when using existing devices and systems, solves problems, and achieves the desired results described herein.

In the foregoing description, certain terms have been used for brevity, clarity, and understanding, however, no unnecessary limitations are to be implied therefrom because such terms are used for descriptive purposes and are intended to be broadly construed. Furthermore, the descriptions and illustrations herein are by way of example, and the inventive features are not limited to the exact details shown and described.

It should be appreciated that features and/or relationships associated with one example arrangement may be combined with features and/or relationships from another example arrangement. That is, various features and/or relationships from the various arrangements may be combined in further arrangements. The inventive scope of the present disclosure is not limited to only the exemplary arrangements that have been shown and described herein.

In the claims, any feature described as a means for performing a function shall be construed as encompassing any means known to those skilled in the art to be capable of performing the recited function, and shall not be limited to the structures shown herein or mere equivalents thereof.

Having described the features, discoveries and principles of new and useful features, the manner of construction, use and operation thereof, and the advantages and useful results attained, the new and useful structures, devices, elements, arrangements, components, combinations, systems, apparatuses, operations, methods and relationships thereof are set forth in the appended claims.

Claims (24)

1. An apparatus, comprising:

a structure configured to be releasably received in a rotatable centrifuge drum, wherein the structure is positionable within the drum and operable to separate cells in a cell culture material into a cell concentrate and a cell centrate within an interior region of the structure,

wherein the structure in the operative position comprises:

the shape of the upper disk is partially changed,

the lower part of the upper part is provided with a plurality of grooves,

a cylindrical core positioned vertically intermediate the upper disc-shaped portion and the lower portion,

a separation chamber disposed radially outward from and in surrounding relation to the core,

an outer wall configured to operatively engage with the drum, wherein the outer wall

Extending in fluid-tight relationship with the upper disc-shaped portion and defining the separation chamber,

extends in surrounding relationship with the core and the separation chamber, and

having an inner frustoconical shape with a smaller inner radius near the lower portion than near the upper disk portion,

a feeding pipe which extends vertically is arranged on the feeding pipe,

a vertically extending centrate discharge tube,

a vertically extending concentrate discharge tube,

wherein the upper disc portion and the outer wall are rotatable about a vertical axis in operative engagement with the drum,

a centrate centrifugal pump axially aligned with the core, the centrate centrifugal pump disposed coaxially about the feed tube and in fluid communication with the centrate discharge tube,

wherein the centrate radial pump is positioned in a centrate radial pump chamber within the upper disc shaped portion,

wherein the centrate centripetal chamber is in fluid communication with the separation chamber through at least one centrate channel extending in the upper disc portion,

wherein each centrate channel fluidly extends between a respective centrate channel inlet located radially outward of the core and the centrate pumping chamber,

a concentrate centripetal pump wherein the concentrate centripetal pump is axially aligned with the core, the concentrate centripetal pump being coaxially disposed about the feed tube, the concentrate centripetal pump being positioned vertically above the centrifugal filtrate centripetal pump and in fluid communication with the concentrate discharge tube,

wherein the concentrate centripetal pump is positioned in a concentrate centripetal pump chamber within the upper disc shaped portion,

wherein the concentrate centripetal chamber is in fluid communication with the separation chamber through at least one radially extending concentrate channel extending in the upper disc shaped portion,

wherein each of the at least one radially extending concentrate channels extends radially between respective concentrate channel inlets positioned radially outward of each centrate inlet,

wherein, during rotation of the drum, the upper disc-shaped portion and the outer wall rotate relative to each of the feed pipe, the centrate discharge pipe, the centrate centrifugal pump, and the centrate centrifugal pump,

wherein each said concentrate passage comprises a passage portion intermediate the respective said concentrate passage inlet and the concentrate centripetal chamber, the cross-sectional area of said passage portion perpendicular to the direction of flow of concentrate within the respective concentrate passage portion region increasing progressively successively with increasing corresponding radial proximity to said axis.

2. The apparatus as set forth in claim 1, wherein,

wherein the channel portion of each of the concentrate channels begins at the respective concentrate channel inlet and extends radially inward.

3. The apparatus as set forth in claim 1, wherein,

wherein the channel portion of each of the concentrate channels begins at the respective concentrate channel inlet and extends upwardly and radially inwardly from the concentrate channel inlet.

4. The apparatus as set forth in claim 1, wherein,

wherein the channel portion of each of the concentrate channels begins at the respective concentrate channel inlet and extends upwardly and radially inwardly from the concentrate channel inlet,

wherein each said concentrate channel further comprises a horizontal and radially extending portion, wherein said horizontal and radially extending portion fluidly extends intermediate said channel portion and said concentrate centripetal chamber.

5. The apparatus as set forth in claim 1, wherein,

wherein the channel portion of each of the concentrate channels begins at the respective concentrate channel inlet and extends upwardly and radially inwardly from the concentrate channel inlet,

wherein each said concentrate channel further comprises a horizontal and radially extending portion, wherein said horizontal and radially extending portion fluidly extends intermediate said channel portion and said concentrate centripetal chamber,

wherein the horizontal and radially extending portion of each said concentrate channel terminates radially inwardly at the outlet of the respective cell concentrate channel in the concentrate centripetal chamber,

wherein the horizontally and radially extending portion of each of the concentrate passages has a constant cross-sectional area throughout its length.

6. The apparatus as set forth in claim 1, wherein,

wherein the channel portion of each of the concentrate channels begins at the respective concentrate channel inlet and extends upwardly and radially inwardly from the concentrate channel inlet,

wherein each said concentrate passage further comprises a respective horizontal and radially extending portion, wherein said horizontal and radially extending portion extends radially outwardly from said concentrate centripetal chamber.

7. The apparatus as set forth in claim 1, wherein,

wherein the channel portion of each of the concentrate channels begins at the respective concentrate channel inlet and extends upwardly and radially inwardly from the concentrate channel inlet,

wherein each said concentrate passage further comprises a respective horizontal and radial extension, wherein said horizontal and radial extension extends outwardly from said concentrate centripetal chamber,

wherein the channel portion terminates radially inward at the horizontal and radially extending portion,

wherein the horizontal and radially extending portion of each respective concentrate passage has a constant cross-sectional area throughout its length.

8. The apparatus as set forth in claim 1, wherein,

wherein the channel portion of each of the concentrate channels begins at the respective concentrate channel inlet and extends upwardly and radially inwardly from the concentrate channel inlet,

wherein each said concentrate channel further comprises a respective horizontal and radial extension, wherein said horizontal and radial extension extends from a respective cell concentrate channel outlet outwardly to said concentrate centripetal chamber,

wherein the concentrate centripetal pump comprises a concentrate centripetal pump inlet, wherein each of the cell concentrate channel outlets is axially and radially aligned with the concentrate centripetal pump inlet,

wherein each channel portion terminates radially inwardly at a respective said horizontal and radially extending portion,

wherein the horizontal and radially extending portion of each respective concentrate passage has a constant cross-sectional area throughout its length.

9. The apparatus as set forth in claim 1, wherein,

wherein the upper disc portion comprises an upper component and a lower component in an engaging relationship,

wherein each of the concentrate passages is defined by at least one lower surface of the upper member and at least one upper surface of the lower member.

10. The apparatus as set forth in claim 1, wherein,

wherein the at least one radially extending concentrate passage comprises a single substantially annular concentrate passage.

11. The apparatus as set forth in claim 1, wherein,

wherein the at least one radially extending concentrate passage comprises a plurality of individual, angularly spaced concentrate passages.

12. The apparatus as set forth in claim 1, wherein,

wherein the at least one radially extending concentrate passage comprises a single substantially annular concentrate passage,

wherein the channel portion of the concentrate channel begins at the substantially annular concentrate channel inlet and extends upwardly and radially inwardly from the concentrate channel inlet.

13. The apparatus as set forth in claim 1, wherein,

wherein the at least one radially extending concentrate passage comprises a single substantially annular concentrate passage,

wherein the channel portion of the concentrate channel starts at the substantially annular concentrate channel inlet and extends upwardly and radially inwardly from the concentrate channel inlet,

wherein the concentrate channel further comprises a substantially annular horizontal and radial extension, wherein the horizontal and radial extension extends from the substantially annular cell concentrate channel outlet outwards to the concentrate centripetal chamber,

wherein the channel portion terminates radially inward at the horizontal and radially extending portion.

14. The apparatus as set forth in claim 1, wherein,

wherein the at least one radially extending concentrate passage comprises a single substantially annular concentrate passage,

wherein the channel portion of the concentrate channel starts at the substantially annular concentrate channel inlet and extends upwardly and radially inwardly from the concentrate channel inlet,

wherein the upper disc portion comprises a substantially annular funnel channel, wherein the annular funnel channel extends upwardly and radially inwardly to the annular concentrate channel inlet.

15. The apparatus as set forth in claim 1, wherein,

wherein the at least one radially extending concentrate passage comprises a single substantially annular concentrate passage,

wherein the channel portion of the concentrate channel starts at the substantially annular concentrate channel inlet and extends upwardly and radially inwardly from the concentrate channel inlet,

wherein the upper disc portion comprises a substantially annular funnel channel, wherein the annular funnel channel extends upwardly and radially inwardly to the annular concentrate channel inlet,

wherein the upper disc-shaped portion comprises a substantially annular cell concentrate guiding surface, wherein the annular cell concentrate guiding surface extends below the annular funnel channel and delimits the separation chamber radially outwards,

wherein the annular cell concentrate guiding surface further extends radially outward and upward to access the annular funnel channel.

16. The apparatus as set forth in claim 1, wherein,

wherein the at least one radially extending concentrate passage comprises a single substantially annular concentrate passage,

wherein the channel portion of the concentrate channel starts at a substantially annular concentrate channel inlet and extends upwardly and radially inwardly from the concentrate channel inlet,

wherein the upper disc portion comprises a substantially annular funnel channel, wherein the annular funnel channel extends upwardly and radially inwardly to the annular concentrate channel inlet,

wherein the upper disc portion comprises a substantially annular cell concentrate guiding surface, wherein the annular cell concentrate guiding surface extends below the annular funnel channel and delimits the separation chamber radially outwards,

wherein the annular cell concentrate guiding surface further extends radially outward and upward to approximate the annular funnel channel,

wherein the upper disc-shaped portion is delimited at a lower side in the separation chamber by a radially extending surface, wherein the radially extending surface terminates radially outwards at a substantially annular edge, wherein the annular edge is axially above the radially outwards extending annular cell concentrate guiding surface, and wherein the annular funnel channel extends upwards from the annular edge.

17. The apparatus as set forth in claim 1, wherein,

wherein the at least one radially extending concentrate passage comprises a plurality of individual, angularly spaced concentrate passages,

wherein the channel portion of each respective concentrate channel

Starting at the respective concentrate passage inlet and extending upwardly and radially inwardly from the concentrate passage inlet, an

Having a constant cross-sectional width perpendicular to the direction of flow of the concentrate and a vertical height that varies with radial distance from the axis.

18. The apparatus as set forth in claim 1, wherein,

wherein the at least one radially extending concentrate passage comprises a plurality of individual, angularly spaced concentrate passages,

wherein the channel portion of each respective concentrate channel

Starting at the respective concentrate passage inlet and extending upwardly and radially inwardly from the concentrate passage inlet, and

having a constant cross-sectional width perpendicular to the direction of flow of the concentrate and a vertical height that varies with radial distance from the axis,

wherein the upper disc portion comprises a plurality of angularly spaced vertical openings, wherein a respective said vertical opening extends between a radially outer periphery of the separation chamber and a respective said passage inlet.

19. The apparatus as set forth in claim 1, wherein,

wherein the at least one radially extending concentrate passage comprises a plurality of individual, angularly spaced concentrate passages,

wherein the channel portion of each respective concentrate channel

Starting at the respective concentrate passage inlet and extending upwardly and radially inwardly from the concentrate passage inlet, an

Having a constant cross-sectional width perpendicular to the direction of flow of the concentrate and a vertical height that varies with radial distance from the axis,

wherein the upper disc portion comprises joined upper and lower components, wherein each of the concentrate passages is defined by a respective surface of each of the upper and lower components.

20. The apparatus as set forth in claim 1, wherein,

wherein the structure comprises a single-use structure.

21. An apparatus, comprising:

a structure configured to be releasably received in a rotatable centrifuge drum, wherein the structure is positionable within the drum and operable to separate cells in a cell culture material into a cell concentrate and a cell centrate within an interior region of the structure,

wherein the structure in an operative position comprises:

the upper disk-shaped part is provided with a plurality of concave grooves,

a cylindrical core extending vertically below the upper disc-shaped portion,

an outer wall configured to operatively engage with the drum, wherein the outer wall

Extends in fluid-tight engagement with the upper disk portion,

extends in surrounding relationship to the core,

has a truncated conical shape with a smaller inner radius at the end of the structure that is vertically disposed away from the upper disc-shaped portion,

defining a separation chamber within the structure, the separation chamber extending radially intermediate the core and the outer wall in surrounding relation to the core, a vertically extending cell culture material feed tube,

a vertically extending centrate discharge tube,

a vertically extending concentrate discharge tube,

wherein the upper disc-shaped portion and the outer wall are rotatable in operative engagement with the bowl about a vertical axis, wherein the feed tube, the centrate discharge tube and the concentrate discharge tube are coaxial with the vertical axis,

wherein the upper disc portion comprises:

a centrate centripetal pumping chamber, wherein the centrate centripetal pumping chamber is in fluid communication with the separation chamber through at least one centrate opening,

a concentrate centripetal pumping chamber, wherein the concentrate centripetal pumping chamber is in fluid communication with the separation chamber through at least one concentrate channel, wherein the at least one concentrate channel

Comprising a concentrate channel inlet, wherein the concentrate channel inlet is disposed radially outward from the at least one centrate opening,

extending radially and fluidly between the at least one concentrate inlet and the concentrate pumping chamber,

a centrate radial pump, wherein the centrate radial pump is coaxially disposed about the feed pipe in the centrate radial pump chamber and the centrate radial pump is in fluid communication with the centrate discharge pipe,

a concentrate centripetal pump, wherein the concentrate centripetal pump is coaxially disposed about the feed tube in the concentrate centripetal pump chamber, the concentrate centripetal pump being positioned vertically above the concentrate centripetal pump and in fluid communication with the concentrate discharge tube,

wherein, during rotation of the drum, the upper disc-shaped portion and the outer wall rotate relative to each of the feed pipe, the centrate discharge pipe, the centrate centrifugal pump, and the centrate centrifugal pump,

wherein each said concentrate passage comprises a passage portion extending intermediate the respective said concentrate passage inlet and the concentrate centripetal chamber, wherein the cross-sectional area of said passage portion perpendicular to the direction of flow of concentrate within the respective concentrate passage portion increases progressively and continuously with corresponding increasing proximity radially to said axis.

22. The apparatus as set forth in claim 21, wherein,

wherein each respective concentrate passage portion begins at a respective concentrate passage inlet of a respective concentrate passage and extends upwardly and radially inwardly from the respective passage inlet.

23. The apparatus as set forth in claim 22, wherein,

wherein at least one of the channels comprises a single substantially annular concentrate channel.

24. The apparatus as set forth in claim 22, wherein,

wherein at least one of the passages comprises a plurality of individual, angularly spaced concentrate passages.

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