JP2003093922A - Centrifugal separation bowl - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel centrifugal separation bowl for treating particles suspended in liquid. SOLUTION: This centrifugal separation bowl 10 contains an inside cavity 120 and an outside cavity 150 arranged concentrically with a rotation shaft. The inside cavity 120 is preferably constituted so as to be parallel with the rotation shaft and have the annular cross-sectional area which increases toward the centripetal side of the cavity from the centrifugal side of the cavity. The constitution permits a quasi- rigid rotation stratified flow field to be generated on the rotation of the centrifugal separation bowl, the field aids Corioli's force to be uniformly dispersed all over the surrounding of the cavity and prevents turbulent mixing of the particles. The outside cavity 150 separates the particles in accordance with the density before treating the same through the inside cavity. The constitution is suitable for the treatment of whole blood in particular, in which platelet-enriched plasma is picked with a reduced leukocyte contamination level. An annular plate 129 is disposed on the inside cavity 120, annular plates 170-173 and level differences are disposed on the outside cavity 150, thereby, Ekman layers E4, E5 which generate a flow parallel and/or vertical to the rotation shaft and Stewartson layers S4, S5 are additionally established and the separation is improved.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to the field of particle separation, and more particularly to a centrifuge bowl for separating particles of different sizes and / or densities suspended in a liquid. More particularly, when applied to the medical field, the present invention relates to an improved centrifuge bowl which makes it possible to produce platelet products with significantly lower leukocyte contamination levels.

[0002]

BACKGROUND OF THE INVENTION In many technical fields it is desirable to separate particles suspended in a liquid. For example, in the medical field, it is desired to fractionate human whole blood for the purpose of blood transfusion. Specifically, human whole blood contains blood cells such as red blood cells, white blood cells and platelets, which are suspended in plasma, an aqueous solution of proteins and other chemicals. Today's transfusions are widely practiced by transfusing only the blood components needed by a particular patient, rather than using whole blood transfusions. Transfusing only the blood components that are needed saves the available blood supply and is often convenient for the patient.

For this purpose, human whole blood is separated into various blood components using a procedure called apheresis. According to a typical apheresis process, whole blood has a high density component such as red blood cells, at least one intermediate density component such as white blood cells such as platelets, lymphocytes and granulocytes, and a low density component such as plasma. And the desired blood component is collected alone or in plural. Among the various blood component products or fractions that can be obtained through apheresis, the demand for concentrated platelet products is rapidly increasing. This is because it is necessary to administer more platelets to patients whose hematopoietic function is often reduced after receiving chemotherapy or radiation therapy as the treatment of cancer develops.

As is well known, platelets have a short half-life of 4-6 days and usually have a limited number of donors. Therefore, in the production of a concentrated platelet preparation, that is, platelet-rich plasma, it is important to separate the platelets from the whole blood supplied by the donor in the maximum yield. It is also known that concentrated platelet preparations contaminated with leukocytes can cause serious complications such as GVH reaction. Therefore, it is also very important to keep the level of leukocyte contamination as low as possible while maximizing the yield of platelets.

Recent immunological studies have shown that the side effects of the contaminant leukocyte can be significantly reduced, if not completely avoided, if the contamination level is sufficiently low. For example, if the number of white blood cells contained in a 200 ml infusion bag that may contain 2.0-3.0 × 10 ¹¹ platelets is 5 × 10 ⁷ or less, a non-hemolytic fever reaction (NHFR ) Has been reported to rarely develop. Similarly, the level of white blood cells in the bag is 1.0 each
CMV if x10 ⁷ and 1.0 x 10 ⁶ or less
It has been recognized that complications such as viral infections and alloimmune reactions rarely occur (Kazuo Tsubaki, latest medicine, Vol. 48, 7).
Issue (1993) pages 989-996). In view of these, it is desirable to be able to consistently produce a concentrated platelet preparation having leukocytes of 1.0 × 10 ⁶ or less through apheresis.

Among several available apheresis methods, the intermittent blood flow method and the continuous blood flow method are widely used. Centrifugation is widely accepted as a technique for separating blood components by density, that is, specific gravity. Centrifuge bowls of the type disclosed in U.S. Pat. No. 4,300,717, herein referred to as "Latham" bowls, are representative of centrifuge bowls for use with intermittent blood flow systems. The bowl consists of a rotor part in which the blood components are separated and a stator part with inlet and outlet ports, which are connected by a rotary seal. The rotor part consists of a frustoconical body,
A similarly shaped core is concentrically disposed within it, forming a fractionation chamber between them. In use, anticoagulated whole blood is introduced into the bowl through the inlet port. The rotor is rotated at a constant or variable speed and the blood components are separated by density in the fractionation chamber by centrifugation. As whole blood continues to flow from the inlet port into the bowl, the separated blood components are gradually displaced inward from the radially outer portion of the bowl and sequentially reach the outlet port. The blood components flowing out of the outlet port are sorted and stored, while the remaining components in the bowl are usually returned to the patient or donor.

Various excellent techniques have been developed in connection with the Latham Bowl to maximize platelet yield while reducing white blood cell contamination. For example, U.S. Pat. Nos. 4,416,654 and 4,416,654 to Schoendorfer et al. Assigned to the same assignee as the present application, "surge"
The technology is disclosed. According to this surge technique, when whole blood is collected and separated into a red blood cell layer, a buffy coat layer that is a mixture of platelets and white blood cells, and a plasma layer in a fractionation chamber, a low density component, preferably Plasma is pumped through the centrifuge at a relatively high flow rate. Platelets and white blood cells in the buffy coat layer, which have similar densities but different effective diameters, undergo centrifugal elutriation, which improves the yield of platelets.

Also assigned to the assignee of the present application
According to Latham et al., U.S. Pat. Further improved. This technique is called "dwell" and platelets and white blood cells are effectively separated and arranged in order of size during the dwell before being drained from the centrifuge using the surge technique. The '592 and' 579 patents also teach recirculating plasma during whole blood sampling to dilute the whole blood and promote separation between blood components.

According to the dwell technique, leukocyte contamination levels are reduced to the order of 1.0 × 10 ⁷ per infusion bag containing platelets in the normally required dose. However, it is desirable to further reduce contamination levels to meet today's demanding therapeutic needs.

On the other hand, centrifugal elutriation is also widely used in the field of continuous blood flow apheresis. For example, U.S. Patent Nos. 4,268,393 and 4,2
69,718, 4,350,283 and 4,798,579 describe a funnel-shaped or conical chamber that can be rotated with a centrifuge around an axis of rotation for centrifugal elutriation. Usually, the chamber extends from an inlet located on the distal side towards an outlet located on the centripetal side. When a low-density fluid, such as plasma, is pumped through the chamber, small cells with slow sedimentation rate can exit the chamber through the outlet, while larger cells with faster sedimentation rate are retained in the chamber. . By appropriately controlling the rotation speed, cells having a desired diameter can be sequentially flown out of the chamber by elutriation.

However, centrifugal elutriation with this type of chamber has many inherent drawbacks. Specifically, as cells enter a chamber that spins around the axis of a centrifuge and plasma is pumped through the chamber, Coriolis forces, known to cause vortexes, are generated, which cause the cells to At the same time, it flows as a turbulent flow along the chamber wall facing the rotation direction of the centrifuge. This causes the cells undergoing separation in the chamber to mix and also send the cells directly from the inlet to the outlet without passing through a region where centrifugal elutriation would theoretically occur. This significantly reduces the efficiency of centrifugal elutriation. Another problem with these prior art centrifugal elutriations is the mixing of cells by concentration inversion. Since the chamber extends from the inlet to the outlet, the velocity of cells entering the chamber decreases as it moves from the inlet to the outlet. This results in a high concentration near the outlet and a low concentration near the inlet. This condition is unstable and can cause reversal and turbulent mixing when centrifugal forces push cells in the high concentration region near the outlet towards the inlet.

US Pat. No. 5,674,173 to Hlavinka et al.
A technique is described which alleviates the above-mentioned problems while enjoying the advantages of centrifugal elutriation. According to the '173 patent, a chamber having an axial cross section in the shape of a kite is provided on a centrifuge for rotation therewith. The inside of the chamber narrows from the maximum cross-sectional area near the outlet toward the inlet. Inside this there is one or more grooves surrounding the longitudinal axis of the chamber,
The Coriolis force is distributed circumferentially about this longitudinal axis. However, the shape of the chamber of this 173 patent is still approximately conical, the Coriolis forces are not well distributed through the grooves, and still the separated cells along the chamber wall oriented in the direction of rotation. Turbulent mixing of Further, the '173 patent states that a saturated bed of platelets is established in the area of maximum cross-section, which bed rejects white blood cells, but a circulating flow is formed between the bed of platelets and the plasma upstream. Yes, this can also cause eddy mixing of cells.

[0013]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improved centrifuge bowl for separating particles suspended in a liquid, especially blood components or cells of whole blood. .

Another object of the invention is to provide a centrifuge bowl for separating or harvesting platelets in high yield with significantly lower leukocyte contamination levels.

A further object of the present invention is to provide a centrifuge bowl which, while providing the above-mentioned advantages, can be mounted on a conventional apheresis device and can be operated according to conventional protocols. Is.

A further object of the present invention is to provide a centrifuge bowl that is simple in construction and cheaper to manufacture.

[0017]

In accordance with one aspect of the present invention, a centrifuge bowl has an inlet port, an outlet port, and
It comprises at least one annular cavity formed and arranged concentric with the axis of rotation of the centrifuge bowl. The annular cavity communicates at its centripetal and distal edges with an inlet port and an outlet port, respectively, whereby liquid flowing from the inlet port flows through the cavity towards the axis of rotation and then out the outlet port. The present inventor has previously proposed a centrifuge bowl of this type (Japanese Patent Application No. 2000-94690), but here, further toward the inside of this annular cavity, radially inward, that is, on the centrifugal side. It is proposed to provide a member protruding from the center to the centripetal side.

Preferably, the bowl comprises a hollow bowl body having an opening at one axial end, the inlet port and the outlet port being in fluid communication with the interior of the bowl through this opening, for example through a tube. If necessary, a rotating seal is placed to cover the opening. A core can be disposed within the hollow interior of the bowl body for rotation therewith, and an annular cavity is defined between the bowl body and the core. The bowl body and core can also form an axial gap therebetween to define a passage for directing liquid radially outward from the inlet port to the distal peripheral edge of the cavity.

This type of centrifuge bowl is suitable for treating liquids containing first and second particles of similar density but different diameters. Fractionated whole blood, which contains platelets and white blood cells suspended in plasma, is a good example of such a liquid. This bowl can be employed, for example, as a secondary centrifuge in an apheresis device and is operable to receive platelet-rich plasma from the main centrifuge and purify it by reducing the level of leukocyte contamination. . However, other uses will be apparent to those of skill in the art and are within the scope of the invention. For example, other blood components can be properly processed by the bowl. The bowl can also be scaled accordingly to process whole blood rather than blood fractions. It is possible to collect platelets containing very little leukocyte contamination from whole blood, or to collect a leukocyte fraction containing very little platelet and erythrocyte contamination from whole blood. Furthermore, it is within the skill of one in the art to provide two or more such annular cavities in series, if desired.

Basically, it is believed that the particles suspended in the liquid are separated by centrifugal elutriation as the liquid flows through the annular cavity during rotation of the centrifuge bowl. Specifically, in the case of buffy coat or plasma containing platelets and white blood cells, these particles have similar densities. However, since white blood cells have a larger diameter, the speed at which they move radially outward by the applied centrifugal force, that is, the sedimentation speed is faster than that of platelets, according to Stokes' law. Therefore, by feeding such a plasma suspension from the inlet port to the outlet port through the cavity, platelets can be collected in high yield while leaving leukocytes in the cavity. From this point of view, the present invention may have commonality with the above-mentioned prior art centrifugal elutriation.

However, the cavity according to the invention is of annular shape, whereas the prior art chamber for centrifugal elutriation is not. As mentioned above, prior art centrifugal elutriation devices suffer from the Coriolis forces adversely resulting in turbulent mixing of separated particles along the rotationally facing chamber walls. According to the invention, the cavity having an annular configuration allows the liquid in the centrifuge bowl to flow circumferentially. The Coriolis force causes the liquid to circulate exactly in the circumferential direction. This flow is called geostrophic flow. As a result, it is considered that the Coriolis force is not localized and is uniformly dispersed over the entire cavity. Therefore, according to the present invention, the problems of the prior art associated with the localization of the Coriolis force can be avoided.

Although the present inventor does not wish to be bound by a particular theory or action, it is considered that a phenomenon known as quasi-rigid rotational stratification is generated in the annular cavity. That is, when a liquid containing suspended particles is introduced during the rotation of a centrifuge bowl and fills the cavity, most of the liquid flow is formed as Stewartson and Ekman layers, which form along the walls of the cavity. It is done through known thin layers. It is believed that these layers are established quickly if the liquid entering the centrifuge bowl is sufficiently accelerated to obtain a rotational angular velocity close to that of the centrifuge bowl, which will increase the angular momentum of the system throughout the cavity. Disperse. Because of this, no turbulence occurs in the cavity. As the particles move through the Stewartson and Ekman layers, they are separated by centrifugal elutriation and particles with faster sedimentation velocity are blocked from escaping from the cavity or diverted from these layers It is taken up in the internal basin formed between. It is also envisioned that some of the particles somehow circulate in the cavity with the liquid, which also facilitates separation between the particles.

As described above, the present invention is provided with the member protruding inward in the radial direction toward the inside of the annular cavity. This is, for example, an annular plate having an outer circumference and an inner circumference, and this annular plate is attached to the wall surface of the annular cavity on the outer peripheral side, usually on the radial outer side or the centrifugal side wall surface of the annular cavity, and the inner peripheral side has It exists inside the hollow of the cavity. Of course, the annular plate may be integrally formed with the bowl body or core when creating the annular cavity. The inner peripheral end surface of the annular plate is parallel to the rotation axis,
That is, it is preferable to concentrically surround the rotating shaft. Such an annular plate forms the Stewartson layer separately along the end face on the inner peripheral side thereof. The Stewartson layer is located inside the radially outer wall surface of the annular cavity, and an annular space is formed between the two, and the liquid hardly flows in the radial direction in this space and is relatively stationary. . Described as particles are separated by centrifugal elutriation during their movement through this Stewartson bed, particles with faster sedimentation velocity in the direction of centrifugal force are
In addition to the area inside the Stewartson layer, it can also be incorporated into this annular space. This increases the efficiency of separation of platelets, for example from white blood cells within the buffy coat. The annular plate is preferably attached near the cavity inlet.

Within the framework of the invention, the annular cavity can take a variety of different forms. One suitable form for an annular cavity is that the area of the annular cross section running parallel to the axis of rotation, ie along an imaginary cylinder centered on the axis of rotation, increases as the diameter of this imaginary cylinder decreases. That is. This is 2π, where r is the radial distance from the axis of rotation and h is the height of the cavity parallel to the axis of rotation at that radial distance.
It is meant that the value described as rh increases with decreasing r. When the annular cavity satisfies this condition, the liquid flowing into the cavity from the centrifugal side peripheral edge, that is, the radial outside of the annular cavity passes through the cavity as it flows toward the centripetal side peripheral edge, that is, the radial inside of the annular cavity. The flow rate is reduced. This is usually preferred for separating particles suspended in a liquid by centrifugal elutriation. As an example, the annular cavity can have a triangular or square axial cross-sectional shape, but it should be understood that other geometric shapes are also possible. Preferably, the maximum annular cross-sectional area is located near the cavity exit, but this precludes providing an annular transition region where the annular cross-sectional area decreases from the maximum annular cross-sectional area to the cavity exit. is not.

Further, the distal peripheral edge of the annular cavity is in fluid communication with the inlet port of the centrifuge bowl and defines a peripheral slot for fluid entry into the cavity.
In fluid communication with the outlet port of the centrifuge bowl and defining a peripheral slot for fluid outflow from the cavity,
It is preferable that the center of the annular cavity is offset vertically along the axis of rotation. This configuration may prevent the fluid flow from being directed radially directly from the distal peripheral edge to the centripetal peripheral edge before the particles are sufficiently separated through the cavity. More preferably, the axial cross section of the cavity is asymmetric with respect to the straight line passing through the inlet and outlet of the cavity. It is also preferred that the cavity terminates on the centripetal side with a cylindrical wall extending along the axis of rotation and a peripheral cavity outlet is formed between the upper and lower peripheral edges of this cylindrical wall.

According to another aspect of the invention, there is provided a centrifuge bowl having a radially outer cavity and a radially inner cavity. This is especially true for particles with different densities,
And suitable for treating liquids containing particles of similar density but different diameters. Whole blood is a typical example, which is amenable to processing in this bowl. This type of centrifuge bowl can advantageously replace a conventional centrifuge bowl, such as the Latham bowl, and can be improved without substantial modification to existing apheresis equipment using the Latham bowl. Good separation can be achieved.

Preferably, the centrifuge bowl according to this aspect comprises a bowl body arranged concentrically with the axis of rotation and a core arranged within the bowl body for rotation therewith, the outer and inner annular rings. A cavity is defined between them. The outer cavity includes a distal peripheral slot in fluid communication with the inlet port and the inner cavity includes a centripetal peripheral slot in fluid communication with the outlet port. The inner and outer annular cavities are in fluid communication with each other via an annular restriction channel formed between the cavities. It is preferred that the annular restriction channels allow only radial communication between the cavities so that the overall height of the centrifuge bowl can be reduced. For the same reason, the axial position of the annular restriction channel is preferably no more than half the axial height of the outer cavity. The annular restriction channel has a low axial height and the flow from the outer cavity is throttled through the annular channel. The inner cavity is usually configured to perform the same function as the annular cavity described above, and so the above description of the annular cavity applies equally to this inner cavity. Of course, it is desirable to place a protruding member, such as the annular plate described above, in the inner cavity, but this is not always necessary. The outer cavity normally serves to separate the particles according to their density, but according to the invention the structure is arranged to produce a flow parallel and / or perpendicular to the axis of rotation. This means, in the simplest case, that the walls of the outer cavity itself are formed parallel or perpendicular to the axis of rotation, but more preferably in addition to these walls it is additionally parallel to the axis of rotation. And / or configurations that produce a vertical flow are employed.

The bowl body may have an opening at one axial end, and a rotary seal assembly having an inlet port and an outlet port may be secured to the bowl body over the opening. The bowl body has a disk-shaped bottom wall,
It can have a two-piece structure, including a molded upper member that can be formed by injection molding. To assemble the bowl, the core is placed on the bottom wall to define a radial gap or passage between the bottom surface of the core and the top surface of the bottom wall, and then the top member is placed over the core. . The top member is then integrated with the bottom wall by hermetically sealing them together at the peripheral edge, and the rotary seal assembly is inserted through and covers the axial opening in the bowl body. This type of centrifuge bowl has a simple structure and can be manufactured inexpensively.

The inlet port is in fluid communication with a radial passageway formed along the bottom wall of the bowl body through which fluid delivered into the inlet port is directed radially outwardly. And flows into the annular outer cavity at the peripheral edge of the centrifugal side. In this case, the inflow preferably takes place from the outermost radial region of the outer cavity. The fluid then enters the annular inner cavity through the annular channel and exits the outlet port in fluid communication with the annular inner cavity.

When whole blood is pumped through the inlet port and guided into the centrifuge bowl, it is directed through the radial passage and flows from the distal peripheral slot into the annular outer cavity. In this case, it is preferable that the inflow from the peripheral slot is performed from the outermost side of the outer cavity as viewed in the radial direction. Within the annular outer cavity, whole blood is separated by centrifugal force and stratified according to density. At this point, the red blood cell layer, the buffy coat layer,
And a plasma layer is formed. With continued collection of whole blood, the separated blood components, beginning with the plasma layer, flow through the annular restriction channel into the inner cavity.

As mentioned above, within the inner cavity:
The components of the buffy coat layer are separated by centrifugal elutriation, and possibly under the influence of quasi-rigid rotational stratified flow, allowing platelets to be recovered in high yield. However, in order to efficiently recover the required volume of platelets by reducing the surge volume, that is, the amount of plasma supplied during centrifugal elutriation, the separation of the buffy coat layer is promoted even in the outer cavity, It is preferable to expel platelets. Further, when the platelets are separated, they are also trapped inside the dense red blood cell layer formed in the outer cavity, but expelling the platelets improves the platelet collection efficiency.

As described above, it is considered that a quasi-rigid rotating stratified flow is generated inside the rotating annular cavity, and most of the liquid flow is formed by the Stewartson layer formed along the wall surface of the cavity. And through the Ekman layer. The present invention establishes these layers by forming the walls of the outer cavity itself parallel or perpendicular to the axis of rotation, and additionally or irrespective of the configuration of the walls of the outer cavity and / or parallel to the axis of rotation. Alternatively, we propose a configuration that separately generates a vertical flow, that is, a configuration that additionally establishes the Stewartson layer and the Ekman layer. This consists, for example, of at least one annular plate arranged inside the outer cavity. Preferably, a plurality of annular plates, for example, about 2 to 5 sheets are arranged concentrically with the rotating shaft depending on the axial height of the outer cavity, and each of the inner plate and the outer peripheral end face has a rotating shaft. Extends parallel to. The cross-sectional shape of the inner peripheral end surface and / or the outer peripheral end surface of this annular plate is preferably rectangular, but a rectangular shape with rounded corners, a semicircular shape,
Alternatively, it may be a semi-elliptical shape. The thickness of the annular plate may be such that the shape can be stably maintained under rotation. Alternatively, the Stewartson layer can be additionally established by providing a step on the inner wall surface of the outer cavity that extends in the outer cavity in parallel to the rotation axis or on the inner wall surface of the outer cavity in the radial direction. The wall surface may include a lower wall surface extending parallel to the rotation axis and an upper wall surface connected to the lower wall surface through a step. The step may extend horizontally radially inward from the lower wall surface to the upper wall surface and the annular restriction channel may be located in the step portion.
The upper wall may be vertical, ie parallel to the axis of rotation, but it will preferably be inclined at an angle of less than 20 ° towards the annular restriction channel. The outer wall surface of the outer cavity in the radial direction can also have a similar inclination.
The smaller the height of the outer cavity, that is, the ratio of the length along the axis of rotation to the radial dimension (aspect ratio), stabilizes the flow.

When the annular plate is arranged inside the outer cavity, the Ekman layer is established along the upper and lower surfaces of the annular plate, and a flow perpendicular to the rotation axis is generated. This allows the trapped platelets to be expelled from the red blood cell layer. In addition, a Stewartson layer is formed along the peripheral edge of the annular plate, particularly along the inner peripheral end surface, over the entire height of the outer cavity regardless of the axial dimension of the inner peripheral end surface. By properly positioning the annular plate so that the buffy coat is located on this inner peripheral end face, the separation within the buffy coat can be promoted. Similarly, if there is an annular wall surface rising from the bottom surface of the outer cavity or a lower wall surface of the above step, a Stewartson layer is formed over the entire height of the outer cavity regardless of their axial height. Therefore, the separation is promoted by aligning the annular wall surface and the lower wall surface with the position where the buffy coat is formed. Further, as described above, it is preferable that the aspect ratio of the outer cavities is small, but by arranging the annular plates, the outer cavities are substantially (the number of the annular plates +1) and have a plurality of reduced effective heights. Can be divided into outer cavities.

The centrifuge bowl according to this aspect of the invention, having an inner cavity and an outer cavity, is sized to have the same diameter dimensions as a conventional Latham bowl, and thus is the assignee of the present application, MA 02184. Braintree, MCS, M manufactured by Haemonetics Corporation of Woodroad 400
It can be attached to conventional apheresis devices such as ulti or CCS. Moreover, the radial positions of these cavities and annular channels are adjusted so that the bowl is compatible with existing optical and / or electronic processing systems of conventional apheresis equipment. For example, an optical sensor for sensing a plasma layer, a buffy coat layer, an erythrocyte layer, etc. is adjusted in position so that the outer cavity and the inner cavity are positioned so as to be positioned near the upper end of the wall surface radially inward of the outer cavity. A bowl can be manufactured. Examples of such optical sensors include full-color sensors such as OMRON E3MC-MY11 and OMRON F
Preferably, a visual sensor such as 150 is used to detect the change in hue.

According to a typical protocol for collecting platelet rich plasma, anticoagulated whole blood is drawn into a bowl at a rate of 20 to 200 ml / min, preferably 50 to 150 ml / min. It When this whole blood is separated inside the outer cavity and the tip of the buffy coat layer approaches the radially inner wall of the outer cavity, or when an annular plate is mounted inside the outer cavity, the buffy coat layer tip When the blood pressure approaches or reaches the inner peripheral end surface of the annular plate, blood sampling is interrupted and plasma is surged at
For example, it is recirculated at a rate in the range of 80 to 240 ml / min, preferably 100 to 200 ml / min to effectively separate platelets and leukocytes. According to this process, platelets are selectively pumped out of the inner cavity via the outlet,
White blood cells are retained within the inner cavity. The blood fraction remaining in the centrifuge bowl is then returned to the patient or donor. The dwell step can be performed prior to the surge step, where the plasma is at a constant or gradually increasing rate in the range of 60 to 160 ml / min without allowing platelets to flow out of the outlet port. Is recycled.
Moreover, during the collection of whole blood into the bowl, it is possible to dilute or compensate for the flow by circulating the plasma. This is known as the critical flow technique.

The above as well as additional objects, features, and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments illustrated in the drawings. The drawings are not necessarily drawn to scale, and exaggerations may have been made to illustrate the principles of the invention.

[0037]

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, an embodiment of a centrifuge bowl 10 having a single annular cavity 20 is shown. In the following, this bowl is a disposable, adapted to treat fractionated whole blood, for example platelets and white blood cells suspended in plasma (hereinafter "platelet-rich plasma fraction" or "PRP fraction") However, it should be understood that the present invention is not limited in any way to this. For example, the bowl of Figure 1 can be used with or without modification to process other whole blood fractions or whole blood itself. Further, as will be described later, the configuration of the annular cavity of the bowl of FIG. 1 can be applied to the inner cavity as it is, as opposed to the configuration of a centrifuge bowl having an outer cavity and an inner cavity for separating whole blood.

As shown in FIG. 1, the bowl includes a rotating seal assembly, ie, a seal and header assembly generally indicated at 30, a bowl body generally indicated at 12, and a core 14.
Consists of. The seal and header assembly 30 is shown in more detail in FIG. This is a rotatable bowl body
Between the interior of 12 and the fixed conduits 41 and 42 connected to the inflow port 31 and the outflow port 32, respectively, are provided passages for rotary seals and fluid communication. The assembly 30 comprises a fixed header, generally designated 33, a feed tube assembly, generally designated 34, an outflow tube 35, and a rotary seal, generally designated 36. The rotary seal 36 comprises a fixed seal ring 37, a diaphragm member 38, and a rotatable seal ring 39 located on the outer seal member or crown 16. The diaphragm member 38 is near its outer peripheral edge,
It is fixed around the seal ring 37. Seal ring
37 includes an annular lip that is in sliding contact with the opposing surfaces of the seal ring 39. The crown 16 may include an axially open groove at its periphery, or is otherwise suitably configured to establish a fluid tight connection with the bowl body 12. Crown 16 has a central opening through which outflow tube 35 extends. The inner peripheral edge of the diaphragm member 38 is joined to the outflow tube 35.

The header 33 is an integrally formed member having an inflow port 31 extending radially toward the axial passage 43. The axial passage 43 is connected to an internal fixed passage 41 formed by an axially extending bore within the feed tube assembly 34 and then to the feed tube stem 18 to allow the PRP fraction to be internal to the bowl body 12. It provides a non-rotating inflow path for inflow. header
33 also includes an outflow port 32, which extends radially into a channel 44 that extends coaxially around the feed tube assembly 34. Channel 44 is then coupled to stationary conduit 42 to form an outlet passage. An outer shield member 40 is formed on the header 33 so as to extend over the rotary seal 36.

The feed tube assembly 34 is formed with a radial flange 34A integral therewith, and the radial flange 35A is integrally formed with the outflow tube 35,
The collecting port 45, which opens radially outward, is connected to the outlet port 32.
Is formed in fluid communication with. Such seal and header assembly 30 is formed and assembled as a separate unit, with the core 14 as shown in FIG.
After being disposed inside 12, it is inserted from the opening 12A of the bowl body 12 and fixed to the bowl body 12 by an appropriate means such as welding or screwing.

The bowl body 12 has a two-piece construction and comprises a molded upper member 11 having an axial opening and a molded lower member or bottom disc 13. These components are suitably made of any plastic material compatible with physiological fluids, such as polycarbonate resins, acrylic resins and polystyrene resins.
After the core 14 is placed on the bottom disc 13, the top member 11
And the disk 13 are assembled and hermetically sealed together, for example by ultrasonic welding. The disk 13 or core 14 includes spacers 15, which are circumferentially arranged at predetermined intervals, eg every 60 °, to separate the disk 13 and the core 14 by an axial gap G, which feed tube stem.
It acts as a radial passage 17 for guiding the PRP fraction introduced from 18 into the cavity 20.

An annular cavity 20 is formed between and bounded by the lower surface of the upper bowl member 11 and the upper surface of the core 14. The cavity 20 has a cavity inlet 21 which is a peripheral slot formed on its centrifugal side.
And a cavity outlet 22 which is a peripheral slot formed on its centripetal side. The inlet slot 21 communicates with the radial passage 17 through an axially extending circumferentially continuous slit 19, and the outlet slot 22, the radially extending passage 23 formed between the upper bowl member 11 and the core 14. Through the collection port 45.

The annular cavity 20 has a substantially triangular shape in the axial cross section. The height of the cavity 20 increases from the inlet slot 21 towards the outlet slot 22 and thus r
Let h be the radial distance from the axis of rotation and h be the height of the cavity 20 parallel to the axis of rotation at that radial distance, the annular cross section given by 2πrh increases with decreasing r. Cavity 20 has an upper annular wall 24 that extends radially inwardly and axially upward from the inlet slot 21 toward the axis of rotation of centrifuge bowl 10 and terminates in upper peripheral wall 25. From there the upper peripheral wall 25
It extends down to the upper peripheral edge of the outlet slot 22.
From the lower perimeter of the outlet slot 22, a lower peripheral wall 26 begins and extends substantially parallel to the axis of rotation until it meets a ramped wall 27 extending radially inward and slightly axially upward from the inlet slot 21. The inclined wall 24 forms an acute angle with the rotation axis. This angle can range from 20 to 60 degrees, preferably
It is in the range of 30 to 50 degrees.

In this arrangement, the inlet slot 21 and the outlet slot 22 are axially offset from each other by a distance approximately equal to the axial length of the lower peripheral wall 26. The amount of this offset can be arbitrarily determined, and the offset may be zero. However, it is generally desirable not to have the inlet slot 21 and outlet slot 22 in a coplanar relationship so that no direct radial passages are formed between these slots as previously described. More preferably, the cavity 20 is formed and the inlet slot 21 and outlet slot 22 are arranged so that the cavity is asymmetric when viewed in axial cross section with respect to the straight line drawn through the slots 21 and 22. Is.

An annular plate is provided near the inlet slot 21.
29 are arranged. The annular plate is attached to the radially outer end of the upper annular wall 24 on the outer peripheral side, and projects on the inner peripheral side toward the inside of the annular cavity 20 in a cantilever manner.
The end surface on the inner peripheral side is parallel to the rotation axis.

Now, with reference to FIG. 2, an expected operation of the annular cavity 20 will be described. Platelet rich plasma or P
When the RP fraction is delivered into the bowl 10 from the inlet port 31, it flows through the conduit 41 and then the stem 18 to the bottom of the bowl. The PRP fraction is guided through the radial passage 17 and the peripheral slit 19 and flows into the radial cavity 20 through the inlet slot 21.

Continued delivery of the PRP fraction into bowl 10 causes cavity 20 to be filled thereby. Bowl 10
Is of sufficient speed, for example 2000 to 7000 rpm, preferably 300
Since it is rotating at 0 to 5000 rpm, a flow field called quasi-rigid rotating stratified flow is created inside the annular cavity 20. PRP fraction goes into bowl 10, 20 to 200 ml /
Min, preferably 50 to 150 ml / min.
This flow rate can be substantially constant over time. Alternatively, the flow rate can increase over time, and a combination of constant and increasing flow rates can be used.

Under the quasi-rigid rotating stratified flow field, Stewartson layers S1 and S2 are generated along the walls 25 and 26, and further Stewartson layer S3 is generated axially along the inner end of the annular plate 29. To be done. Ekman layers E1, E2, and E3 are walls
It is formed along the lower surface of 24 and 27 and the annular plate 29. Most of the flow of the PRP fraction occurs along these layers, with little flow through the interior region indicated by I1.
Also, almost no flow occurs in the inside I2 of the portion surrounded by the annular plate 29 and the wall 24 behind the Stewartson layer S3.

When the platelets and white blood cells contained in the PRP fraction flow into the cavity 20, they flow from the Ekman layer E2 to the Stewartson layer S2, or the Ekman layer E3,
It moves along the Stewartson layer S3, Ekman layer E1, and Stewartson layer S1 and is separated by centrifugal elutriation. When the PRP fraction flows through the Ekman layer, the sedimentation rate of platelets is slower than that of white blood cells, so that the flow of liquid causes the platelets to be dragged toward the exit slot 22 faster than the white blood cells. Most, if not all, leukocytes are retained in the Ekman layers E1 and E2 because leukocytes sediment faster in the centrifugal direction. The remaining white blood cells pass through the Ekman layer and reach the Stewartson layers S1 and S2. In the Stewartson's layers S1, S2, platelets (represented by "x") are subject to the axial drag D created by the viscous plasma flow and are allowed to travel towards the exit slot 22, Larger white blood cells (represented by “◯”) receive the centrifugal force C generated by the rotation of the centrifuge bowl 10 and are given a sedimentation velocity Vs in the centrifugal direction larger than that of the platelets, so that they reach the outlet slot 22. Then, it is taken into the internal area I1. The white blood cells in the Stewartson layer S3 also reach the inner region before reaching the Ekman layer E1.
Captured by I2. Due to the inwardly diverging profile of the cavity 20, the flow rate of the PRP fraction is reduced as it moves inwardly towards the axial walls 25,26. The cells in the PRP fraction are thus centrifugally elutriated through the Ekman and Stewartson layers, and also under quasi-rigid rotating stratified flow fields, the turbulence due to Coriolis forces is suppressed or generated. It is believed that the fact that they do not achieve good separation between platelets and white blood cells. In particular, according to the invention, the Stewartson layer S3 formed by the installation of the annular plate 29, together with the inner region I2 behind it, provides an additional separating field.

Platelets and plasma flowing out of the outlet slot 22 are guided through the radial passage 23 and into the collection chamber 46.
There, a collection port 45 opens radially outward. When the tip of the plasma moving from the chamber 20 and the passage 23 moves inward in the radial direction and reaches the collection port 45, air cannot escape from the inside of the bowl, and therefore the collection chamber overflows with the plasma. It should be noted that there is no.

Typically, the diameter of the bowl 10 is 10-30 cm, depending on the processing capacity required. Preferably 15-20 cm
, Which allows it to be fitted to a conventional apheresis device without substantial modification.

Referring now to FIG. 4, a centrifuge bowl having an inner annular cavity 120 and an outer annular cavity 150.
One embodiment of 110 is shown. The centrifuge bowl 110 comprises a disposable centrifuge rotor or bowl 112 having an opening 112A at one end and a rotary seal assembly 1
It consists of 30 and core 160. The rotary seal assembly 130 is of substantially the same construction as the rotary seal assembly 30 described above with reference to FIG. 3, and thus will not be described in detail here.

As with bowl 10, bowl body 112
Can be made of any suitable plastic material such as transparent polycarbonate resin, acrylic resin, polystyrene resin, or the like, and comprises an upper molding member 111 and a lower molding member or bottom disk 113. The crown 116 of the rotary seal assembly 130 is fixed to the opening 112A by screwing, welding, or the like.

A core 160 disposed inside the bowl body 112
Is a hub 161 having a stepped profile and including a tapered bore 162, a radial disc 163 extending radially outward from one end of the hub 161, and an annulus sandwiched between the hub 161 and the disc 163. Includes shoulder 164. Such a core can be easily manufactured by injection molding. Spacers 115 are angularly spaced, for example 60 ° apart, between the bottom disk 113 of the bowl and the core 160 to guide the liquid introduced from the feed tube stem 118 into the bowl. It defines an axial gap G, which acts as a passage 117.

The upper molding member 111 cooperates with the core 160 having a stepped contour to form the inner and outer annular cavities 12.
It has a shape that defines 0,150. Specifically, in the illustrated example, the upper molding member 111 includes an outer cylindrical portion 151 having inner and outer walls 152, 153, a conical sloping portion 154, and an inner wall 152 and a sloping portion 154. It consists of a straddling neck portion 155. Together with the radial disc 163 of the core 160, the outer cylindrical portion 151 defines an outer cavity 150, which is of generally annular shape with a rectangular cross section. The outer cavity 150 communicates with the radial passage 117 at the lower, peripheral edge. Neck portion 155 and beveled portion 154 cooperate with shoulder 164 of core 160 to define an inner annular cavity 120 having a shape similar to annular cavity 20 of FIG. Outer cavity 150
And the inner cavity 120 are in radial communication with one another via an annular channel 121 located between the rising portion of the shoulder 164 and the neck portion 155.

As shown in FIG. 4, the inner cavity 120 has an upper annular wall 124 defined by a beveled portion 154 extending radially inward and axially upward from the upper end of the annular channel or inlet slot 121. A shoulder 164 extending radially inward and axially upward from the lower end of the annular channel 121.
Bounded axially between the lower annular walls 127 defined by the upper surface of the. The upper side wall 124 forms an acute angle with the rotation axis, and the lower side wall 127 forms an obtuse angle with the rotation axis. The upper annular wall 124 is therefore steeper than the lower annular wall 127, so that the axial height of the inner cavity 120 increases as the distance from the axis of rotation decreases. Preferably, the radial distance decrement is less than the axial height increment, Δr <Δh, and the annular cross-sectional area of the annular cavity 120 given by 2πrh increases as the value of r decreases.

The inner cavity 120 terminates at its radially inner end in upper and lower peripheral walls 125 and 126, with a circumferential exit slot 122 defined therebetween. An annular plate 129 is attached near the inlet slot 121. The upper peripheral wall 125 is defined by the outer peripheral wall of the inner cylindrical portion 156 and the lower peripheral wall 126 is defined by the outer peripheral wall of the hub 161. The inner cylindrical portion 156 is formed from the upper surface of the hub 161 from the radial passage 12
Separated by 3, this passageway is the inner cavity 1
The 20 is in communication with a collection chamber 146 defined between the inner wall 158 of the cylindrical portion 156 and the collection port 145.

Inside the outer cavity 150 is an annular plate 170.
-173 are concentric with the axis of rotation and axially spaced. These annular plates may be connected to the radially outer wall 153 of the outer cavity 150, as shown at 175, for example at 60 ° intervals. This connection is shown only for the annular plate 170, and the remaining annular plates 1
71-173 are omitted for the sake of simplicity. These annular plates 170-173 have an inner peripheral end surface 176 and an outer peripheral end surface 177 extending parallel to the rotation axis, as shown for the annular plate 173. Bowl 110 is particularly suitable for fractionating whole blood and collecting platelets in high yield. The bowl is preferably comparable in diameter dimension to a conventional Latham bowl, but may have a low axial height. Therefore, by mounting an adapter or the like appropriately formed to compensate for this height, the bowl 110 can be made to have the above-mentioned MCS,
It can be attached to a conventional apheresis device, such as a Multi or CCS, and can be operated with existing protocols using existing optical and / or electronic processing systems. In this case, the inner peripheral end surface 176 of the annular plates 170-173 is preferably substantially aligned with the position of the optical sensor BO of the conventional apheresis device in the radial direction. But of course, this does not exclude other bowl configurations. Broadly speaking, the bowl 110 can have a diameter of 10-30 cm, preferably 15-20 cm.

First, by using a peristaltic pump (not shown), anticoagulated whole blood is drawn from the patient or donor, guided into the bowl 110 via the inlet port 131, and rotation of the bowl is prevented. Be started. Blood collection is usually performed at a flow rate of 20 to 150 ml / min, preferably 50 to 100 ml / min, and the bowl is 2000 to 7000 rpm, preferably 3
It can be rotated at a speed of 000 to 5000 rpm. During this blood draw, the flow rate can be substantially constant over time. Alternatively, it can be increased continuously or in steps over time, or a combination of constant and increasing flow rates can also be used.

Whole blood is directed from the inlet port 131 through the feed tube stem 118 into the radial passage 117 and into the outer annular cavity 150 from its lower circumferential edge.
Whole blood is centrifuged and stratified in the outer cavity 150 into a radially outermost layer of red blood cells, and the inner buffy coat and plasma layers. When the whole blood is continuously collected, the separated blood component flows into the inner cavity 120, with the plasma layer as a head. The fractionated blood component is then moved from inner cavity 120 through radial passageway 123 and collected by collection port 145. As in the case of the bowl in Figure 1, the tip of the transferred component is at the collection port.
Upon reaching 145, air is trapped in the center of the bowl and therefore the collection chamber 146 is not flooded with blood components. The fractionated plasma flows out of the outlet port 132 and is collected in a storage bag (not shown).

When the tip of the buffy coat layer approaches or reaches the inner wall of the outer cavity, or when the annular plate is present, approaches or reaches the inner peripheral end surface thereof.
A surge phase can be initiated to separate the platelets and leukocytes present in the buffy coat layer. This surge is earlier or slower, for example, when the tip of the buffy coat layer is still passing through the annular plate, when it approaches the annular channel or inlet slot 121, or when it enters the inlet slot 121 or inner cavity 120. You can start at a point. The tip of the buffy coat layer, as well as other boundaries between separated blood components, may be, for example, optical sensor BO.
Can be detected by. It monitors the radius of the area occupied by the separated blood components in the centrifuge,
It outputs a signal when the radius reaches a specific value.

To perform the surge, the whole blood collection is stopped and a portion of the collected plasma is transferred from the storage bag into the bowl 110 at an increased flow rate, eg 120 to 240 ml /
Min, preferably at a selected flow rate in the range of 160 to 220 ml / min. Prior to this, the components in the buffy coat were removed from the inner cavity 12 with the whole blood collection stopped.
It is also possible to carry out a so-called dwell, which circulates the plasma without letting it flow to zero. Dwell improves the separation of platelets and leukocytes within the buffy coat.
Subsequent surges cause the components in the buffy coat layer to enter the inner cavity 120 and by centrifugal elutriation as they travel through the Ekman and Stewartson layers, as in cavity 20 shown and described with respect to FIG. To be separated. The introduction of plasma is stopped after most of the platelets have been collected in the storage bag. As will be appreciated by those skilled in the art, the dwell step can be performed prior to the surge step, if desired. This process can be repeated as often as desired until sufficient platelets have been collected. The resulting formulation contains high yields of platelets and reduced leukocyte contaminants.

During such a process, the outer cavity
Along the respective radial planes of the annular plates 170-173 within 150, Ekman layers E4 and E5 are established and an inner peripheral end face 176
And Stewartson layers S4 and S5 are established along the outer peripheral surface 177 over the entire axial height of the outer cavity 150. Along these lines, a flow that is parallel or perpendicular to the axis of rotation is created to improve separation. For example, in the Stewartson layer S4, the platelets in the buffy coat are moved in the axial direction by receiving the drag force D, while the larger leukocytes are subjected to the centrifugal force C and are given the sedimentation velocity Vs in the centrifugal direction larger than that of the platelets to flow. Are captured in the area where no. Also, for example, in the Ekman layer E4, platelets are
Washed out of the concentrated red blood cell layer.

FIG. 5 shows still another embodiment. In this embodiment, inside the outer cavity 150, as in FIG.
Again, annular plates 180-182 are concentric with the axis of rotation and axially spaced. The fixation of these annular plates is in this case carried out by means of a pole 183 which extends axially in the outer cavity 150 and which penetrates the annular plates 180-182,
The poles 183 are arranged at intervals of 60 °, for example,
The upper and lower ends are connected to the outer cylindrical portion 151 of the bowl body 112 and the radial disc 163 of the core 160, respectively. In this embodiment, the inner wall 152 of the outer cavity 150 is
It is composed of a lower wall 184 which is an annular wall surface extending parallel to the rotation axis, and an upper wall 186 which forms a step 185 with the lower wall 184. The step 185 is continuous with the annular channel 121, and the upper wall 186 is inclined toward the annular channel 121. The functions of the annular plates 180-182 are the same as those described in FIG. In this configuration, the vertically extending lower wall 184 forms the Stewartson layer S6, which produces a flow field parallel to the axis of rotation similar to the Stewartson layers S4 and S5 described in FIG. The lower wall 184 realizes the function of the inner peripheral end surface of the annular plate in another way by utilizing the configuration of the annular channel 121. Even if the height is low, for example, even about 1 mm, Stewart The Sonn layer S6 is well established for improved separation. Figure 5 shows an annular plate
Although the combination with 180-182 is shown, an excellent effect can be obtained only by the lower wall 184 without providing the annular plate.

[0065]

EXAMPLE A centrifuge bowl having the structure shown in FIG. 4 but having no annular plate in the outer cavity but having an annular plate attached to the inner cavity was used. The outer cavity has a radial outer wall distance of 59 mm from the axis of rotation, the inner radial wall has a distance of 45 mm from the axis of rotation, and the inner cavity has a radial inner wall of 23 mm from the axis of rotation. The maximum heights of the outer cavity and the inner cavity were 34 mm and 20 mm, respectively, and the outlet of the inner cavity was set at a position about 11 mm higher than the inlet. The volume of the outer cavity and the inner cavity is 155m each.
1 and 36 ml. This centrifuge bowl is a CCS which is a blood component centrifuge made by Haemonetics.
It was attached to the centrifugal rotation device (product name) and rotated at a predetermined rotation speed. Using a peristaltic pump, anti-coagulant-added human whole blood collected the day before was fed into a centrifuge bowl at a rate of 60 ml / min. When the buffy coat (a milky white layer consisting of platelets and white blood cells and formed inside the red blood cell layer) reaches a position 2 mm from the inner wall in the radial direction of the outer cavity, the delivery of whole blood is stopped and collected in advance. The surge operation was started using the stored plasma. Until the concentration of platelets in the outflowing plasma is reduced, the outflowing plasma is reduced to 10
Each tube was collected in a test tube. The surge operation is a method in which blood plasma is sent to a centrifuge bowl while gradually increasing its speed to selectively flow out and collect only platelets. It takes 30 seconds to change from a predetermined initial speed to a predetermined final speed. Manipulated to increase to speed. After that, liquid transfer was continued while maintaining the final speed. The number of platelets and white blood cells in the collected plasma was measured, the yield was calculated with respect to the number of platelets introduced into the centrifuge bowl, and 10 units of platelets (2
The number of white blood cells likely to be mixed when (x10 ¹¹ ) were collected was determined by extrapolation. The operating conditions and results are summarized in the table below.

[0066]

[Table 1]

[0067]

The results of Table 1 show that the bowl of the present invention can efficiently collect platelets with very little white blood cell contamination. As explained above, the present invention provides an improved and very advantageous centrifuge bowl for treating particles, in particular blood cells such as platelets and white blood cells. In particular, but not exclusively according to the invention, an improved centrifuge bowl is provided which makes it possible to produce a platelet preparation with a significantly lower leukocyte contamination level. For example, using the bowl of the present invention, it is possible to collect a leukocyte fraction containing very little platelets and red blood cells from whole blood, and it can be expected to have a wide range of applications in the field of stem cell separation and the like.

The terminology and expressions used herein are used as terms of description and not of limitation, and the use of such terms and expressions is illustrated and described in terms of features and There is no intent to exclude anything equivalent to that part. Rather, it will be appreciated that various modifications are possible within the scope of the claimed invention.

[Brief description of drawings]

FIG. 1 is an axial cross-sectional view of one embodiment of a single annular cavity centrifuge bowl according to the present invention.

FIG. 2 is an axial cross-sectional view illustrating a possible operation of the annular cavity shown in FIG.

FIG. 3 is a partially cutaway elevational view illustrating a rotary seal assembly used in the centrifuge bowl of FIG.

FIG. 4 is an axial cross-sectional view of an embodiment of a centrifuge bowl consisting of inner and outer annular cavities according to the present invention. (A) shows the whole and (B) shows the details inside the outer annular cavity.

FIG. 5 is an axial cross-sectional view of another embodiment of a centrifuge bowl consisting of inner and outer annular cavities according to the present invention.

[Explanation of symbols]

10, 110 centrifuge bowl 20 annular cavity 20 annular cavity 21 Cavity inlet 22 Cavity outlet 29 annular plate 30, 130 rotating seal assembly 31, 131 Inflow port 32, 132 Exit port 120 inner annular cavity 121 annular channel 150 outer annular cavity 170-173 annular plate 176 Inner peripheral end face 177 Outer peripheral face 180-182 annular plate 184 Lower wall 185 steps 186 Upper wall S1-S6 Stewartson layer E1-E5 Ekman layer I1-I2 internal area

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Koichiro Sakoda             2-13-3 Shibasaki, Chofu City, Tokyo, A716 F term (reference) 4C077 AA12 BB04 EE01 KK11                 4D057 AA03 AB01 AC01 AC06 AD01                       AE02 AF07 BA13 BC05 BC11

Claims (24)

[Claims] 1. A bowl body adapted to rotate about an axis of rotation, an inlet port, an outlet port, and at least one annular cavity formed in the bowl body concentric with the axis of rotation. An annular cavity configured such that the area of the cylindrical cross section taken around the rotation axis increases from the centrifugal side to the centripetal side, and a cavity inlet formed in the annular cavity on the centrifugal side and communicating with the inlet port And a cavity outlet formed in the annular cavity on the centripetal side and communicating with the outlet port, and a member protruding radially inward into the annular cavity. 2. The bowl body has an opening at one axial end thereof, a rotary seal assembly is secured to the bowl body over the opening, and the inlet port and the outlet port are rotatable. The centrifuge bowl of claim 1 provided in a seal assembly. 3. The centrifuge bowl of claim 1, wherein the cavity inlet comprises a peripheral slot formed in the annular cavity on the centrifugal side. 4. The centrifuge bowl of claim 1, wherein the cavity outlet comprises a peripheral slot formed in the annular cavity on the centripetal side. 5. The projecting member is an annular plate, the outer peripheral side of which is attached to the wall surface of the annular cavity, and the inner peripheral side of the annular plate defines an end surface inside the annular cavity that is parallel to the rotation axis. The centrifuge bowl of claim 1, wherein: 6. The centrifuge bowl according to claim 5, wherein the outer peripheral side of the annular plate is attached near the cavity inlet. 7. A bowl body adapted to rotate about an axis of rotation, an inlet port, an outlet port, an annular inner cavity concentric with the axis of rotation within the bowl body, and the inner side. An annular outer cavity formed concentrically with the rotation axis in the bowl body radially outward of the cavity, and a cavity inlet formed on the centrifugal side of the outer cavity for communicating the outer cavity with the inlet port. A cavity outlet formed on the centripetal side of the inner cavity for communicating the inner cavity with the outlet port, and an annular restriction channel for communicating the inner cavity with the outer cavity, wherein the outer cavity is A centrifuge bowl configured to generate a flow parallel and / or perpendicular to the axis of rotation. 8. The bowl body has an opening at one axial end thereof, a rotary seal assembly is secured to the bowl body over the opening and the inlet port and the outlet port are rotatable. The centrifuge bowl of claim 7, wherein the centrifuge bowl is provided in a seal assembly. 9. The centrifuge bowl of claim 7, wherein the cavity inlet comprises a peripheral slot formed on the centrifugal side of the outer cavity. 10. The centrifuge bowl of claim 7, wherein the cavity outlet comprises a peripheral slot formed on the centripetal side of the inner cavity. 11. The centrifuge bowl of claim 7, wherein the outer cavity comprises therein means for producing a flow parallel and / or perpendicular to the axis of rotation. 12. The means as claimed in claim 11, wherein the means is at least one annular plate located inside the outer cavity.
Centrifuge bowl. 13. The centrifuge bowl according to claim 12, wherein the annular plate is arranged concentrically with the rotation shaft, and an inner peripheral end surface and / or an outer peripheral end surface of the annular plate extends parallel to the rotation shaft. 14. The centrifuge bowl according to claim 12, wherein an inner peripheral end surface and / or an outer peripheral end surface of the annular plate has a rectangular, rounded rectangular, semicircular, or semielliptical cross-sectional shape. 15. The centrifuge bowl according to claim 12, wherein a plurality of the annular plates are provided concentrically with the rotation shaft and spaced along the rotation shaft. 16. The centrifuge bowl of claim 11, wherein said means is an annular wall surface located inside said outer cavity and extending parallel to said axis of rotation. 17. The outer cavity has a wall surface with a step on the centripetal side, and the wall surface has a lower wall surface extending parallel to the rotation axis and an upper wall surface connected to the lower wall surface through the step. 12. The centrifuge bowl of claim 11, comprising: and the means is defined by the lower wall surface. 18. The step extends radially inward from the lower wall surface to the upper wall surface, the annular restriction channel is disposed at the step, and the upper wall surface is inclined toward the annular restriction channel. The centrifuge bowl of claim 17, wherein. 19. The outer cavity has a wall surface with a step on the centripetal side, and the wall surface has an upper wall surface extending parallel to the rotation axis and a lower wall surface connected to the upper wall surface through the step. 12. The centrifuge bowl of claim 11, comprising: and the means is defined by the upper wall surface. 20. The centrifuge bowl of claim 11, wherein the inner cavity is configured such that the area of the cylindrical cross section taken about the axis of rotation increases from the centrifugal side to the centripetal side. 21. The centrifuge bowl of claim 20, further comprising a member that projects radially inward into the inner cavity. 22. The projecting member is an annular plate, the outer peripheral side of which is attached to the wall surface of the inner cavity, and the inner peripheral side of the annular plate defines an end surface parallel to the rotation axis inside the inner cavity. 22. The centrifuge bowl of claim 21, wherein: 23. The centrifuge bowl of claim 22, wherein the outer peripheral side of the annular plate is attached near the annular restriction channel. 24. A buffy coat, wherein the outer cavity contains red blood cells, platelets and white blood cells by centrifuging whole blood,
The centrifuge bowl of claim 11, wherein the centrifuge bowl is adapted to separate into blood plasma and plasma, and the inner cavity is adapted to separate platelets and white blood cells by centrifugal elutriation.