EP3096811A1

EP3096811A1 - Device for separating blood into the components thereof and method therefor and use of said type of device

Info

Publication number: EP3096811A1
Application number: EP15701742.7A
Authority: EP
Inventors: Alexander Heide
Original assignee: Fresenius Medical Care Deutschland GmbH
Current assignee: Fresenius Medical Care Deutschland GmbH
Priority date: 2014-01-25
Filing date: 2015-01-22
Publication date: 2016-11-30
Also published as: US20160279315A1; CN105916533A; WO2015110501A1; CN105916533B; US10335533B2; DE102014000971A1

Abstract

The invention relates to a device for separating blood into the components thereof and to a method therefor and to the use of said type of device. Said device contains a magnetic drive device which offsets a container in rotation about the axis thereof, said container having at least one open end and has at least one inlet in said end and said container is mounted so that it can magnetically suspended.

Description

Device for the separation of blood into its components and methods for this and

Use of such a device

The invention relates to the field of extracorporeal treatment of blood, and more particularly to the field of blood separation, and relates to a device for separating blood into its components and a method therefor. The invention further relates to a treatment unit with a device according to the preamble of claim 1. Moreover, the invention relates to the use of a device for the separation of whole blood and recovery of individual components thereof. A separation of other medical and biological fluids by means of the aforementioned device is also conceivable. The device can thus also be used in other fields in which the separation of fluids according to their density is desired, such as e.g. in the technical, analytical and pharmaceutical fields.

Human blood contains predominantly three types of cells, erythrocytes, leukocytes and platelets, each of which has a specific function for the body. The blood cells are suspended in a complex aqueous solution of proteins and other chemicals, the plasma.

The separation of whole blood into its constituents can be useful or necessary, for example, in the extracorporeal treatment of blood, in order to selectively subject individual components to further treatment. Separation of blood into its components is also accomplished for blood transfusions when high acute or chronic blood loss, such as occurs in chronic blood disorders, such as a blood disorder, necessitates restoring a patient's volume system.

The blood components are transfused as a concentrate (eg erythrocyte, granulocyte, platelet, stem cell concentrate, immunoglobulins, human albumin or plasma or serum (plasma without coagulation factors).) The blood constituents more commonly used in transfusions include the erythrocytes and plasma, for example, plasma transfusions used to refresh spent coagulation factors.

The separation of whole blood into its constituents has the advantage that the patient only receives those blood components that are missing. The patient does not unnecessarily come into contact with other blood components in this way and thus is not exposed to the risk of infection or side effects attached to the transfusion of the other blood components. In addition, the individual blood component concentrates can be stored much longer than the whole blood. Plasma, for example, can be stored in the frozen state for months.

Methods for separating and collecting certain components from whole blood are based on mainly three different separation methods: bag centrifugation, membrane filtration and bell centrifugation or cell separation by means of separation chambers.

In bag centrifugation, a bag filled with anticoagulated whole blood is spun in a laboratory centrifuge at very high speed. The blood is exposed here to a multiple of gravity. Due to the centrifugal force, the individual blood components separate into layers according to their density. Each of the blood components can then be removed individually from the bag. The yield and thus the economic practicability of bag centrifugation are limited, since a donor can not be removed as much blood. Another method, called hemapheresis, is more burdensome for the donor, but offers more scope for the amount of extractable concentrate.

Haemapheresis differs from conventional blood donation through the use of cell separators that have an extracorporeal circuit on the donor. The fractionation of the blood takes place during the donation. Frequently, preparations of only one blood component are obtained, but in recent years, efficient multicomponent methods have also been developed in which several blood components can be collected in parallel.

Upon completion of the procedure, the unused blood components are returned to the donor. In this way, larger amounts of other components can be removed. Only in such a method is it possible to obtain from individual donors sufficient quantities of those blood components which make up only a small proportion of the blood (eg platelets, stem cells).

As a little cost-intensive type of hematopoiesis method, the so-called bell centrifugation is known: anticoagulated blood is placed in a drum, cup, cylinder or bell-shaped container.

This method is used, for example, in the Haemonetics cell separators, in which the blood is separated in a so-called "Latham bell." The container is clamped in a device which rotates the same at high speed. in which the cells are separated into layers according to their density, the denser cells are forced outward from the central axis of the container and accumulate along its inner wall, the least dense plasma remaining in the center of the container.

The bell centrifuge separation is more cost effective as it is simpler in construction and requires less material. The blood components produced, however, have a lower purity: separated plasma may still contain residual blood cells. The process described is a discontinuous process: in this case the removal or separation phase and the return phase are separated in time. However, care must be taken to ensure that the extracorporeal volume does not exceed 15% of the circulating blood volume of the donor to prevent collapse of the circulation. Discontinuous processes are thus slower and the amount of blood concentrate to be recovered is limited by the longest possible duration of use.

If the blood components are to be obtained in greater quantity and in the shortest possible time, the so-called continuous haemopheresis is used.

In the continuous hematopoiesis procedures, the blood components are obtained during the continuous withdrawal of a small amount of blood and the simultaneous return of the unused blood components. Continuous blood flow is maintained.

As a type of continuous hemapheresis method, membrane filtration is known. In this case, a membrane with a suitably small pore size (for example 0.5 μιτι) is used to filter plasma from the blood. However, because of the viscous and complex nature of whole blood, simple filtration is not sufficient because the pores of the membrane are easily clogged by cellular substances or proteins. Therefore, membrane filtration processes typically involve either internal or external rotatable filter media. The rotation relative to an opposite stationary surface causes the transport of whole blood across a membrane surface and thus creates shear forces that drive the plasma through the membrane while flushing away the corpuscular components. Prior art membrane filtration devices can often produce a purer blood product, ie, containing residual cells (eg, leukocytes). To allow collection of, for example, plasma from a single donor at an acceptable rate, a large membrane surface area is required. However, since the costs for the membrane are relatively high and the efficiency decreases with the duration of use, the membrane filtration is also limited practicable. For the extracorporeal circuit, the continuous processes today predominantly use disposable plastic sets with integrated separation chamber. The separation chambers are closed plastic inserts which generally have a separation channel into which the cell suspension to be separated is passed. In this, a separation into individual blood components takes place under the influence of the centrifugal force. In two-part separation chambers, the separation channel is formed by a flexible film part, which is placed in a rigid receiving unit.

The design of the devices used, however, is complicated, since twisting of the inlet and outlet hoses during rotation must be prevented. In addition, the preparation of concentrates with the described separation chambers often leads to an unclean or inadequate separation, in particular of platelets. Also already separated cells can be entrained by turbulence in the transition region between the individual channel sections in another fraction.

In addition to the cell-specific density and the respective cell diameter, the centrifugal acceleration (depending on centrifuge speed and radius of the centrifuge container) is of importance for the yield in a cell separation. The higher the centrifugal acceleration, the greater the separation speed, and hence the centrifugal force, and the better, i. E. more precisely, the cells are separated.

If the centrifuge container is to be as small as possible, the speed necessary to achieve sufficient centrifugal force for the separation must be higher.

The acceleration of the centrifuge chamber can be done for example via a belt drive, a gear transmission or an electric motor.

However, all types of drives have in common the resulting disadvantages such as high running noise, high maintenance, generation of frictional heat and wear.

The separation speed is thus limited and, accordingly, the centrifuge container must have a minimum radius. Many devices are already known from the prior art, which work in the separation of blood into its components according to the aforementioned principles.

A device operating discontinuously on the principle of bell centrifugation is known, for example, from document EP 1 057 534. To increase the yield and accelerate the total application time, a combined use of a centrifuging bell and a membrane filter takes place here.

In EP 1 251 922 a disposable cassette with integrated separation device for plasma separation is described, which cooperates with a reusable module.

Document DE 198 41 835 shows a device for continuous hemapheresis, which has a separation chamber with a spiral-shaped separation channel.

A magnetic transmission for a cell separation centrifuge is known, for example, from DE 198 01 767. The centrifuge has a frame on which a frame and about the axis of a centrifuge chamber are rotatably mounted. The power transmission to the chamber or the rotating frame is non-contact and wear-free via coupling elements by means of magnetic forces.

The document EP 0 819 330 discloses a rotary pump in which the impeller is suspended in the interior of the pump housing by magnetic forces and is driven by a rotating field generated by a stator arranged outside the pump housing.

The document EP 0 900 572 describes a centrifugal pump for conveying blood, in which the impeller is also mounted magnetically and non-contact in the pump housing and driven by an electromagnetic rotary field.

The invention is based on the object to provide a device and a method available, which make it possible to separate blood into its components and thereby in the shortest possible time, ie at high speed, as pure as possible, ie a few residual cells containing and produce uniform blood product. The device should also be designed as small and compact as possible and easy and inexpensive to produce.

At the same time known from the prior art disadvantages of rotary transmissions, such as high running noise, high maintenance, wear and the formation of frictional heat to be avoided.

Another object of the invention is the contamination-free or sterile applicability.

The object is achieved according to the invention with the features specified in claim 1. In this case, the device for separating blood into its components has a magnetic drive device and a container which is set by the drive device in a rotational movement about its own axis, wherein the container has at least one open end and in this at least one inlet and stored magnetically floating is.

Advantageous embodiments of the invention will become apparent from the dependent claims.

The object is further achieved by the method described in claim 9 for the separation of blood into its components. The method can be used for continuous as well as for discontinuous hemapheresis.

Advantageous embodiments of the invention will become apparent here from the dependent claims.

Due to the magnetic drive device and the floating, i. Non-contact storage no friction occurs during operation of the separator. Thus, the speed with which the container is rotated, can be increased and the container itself can be made small and compact, so that this u.a. also as a disposable item executable.

In addition, all associated with a non-floating storage disadvantages, such as the high running noise, the generation of frictional heat, the rapid wear and thus the associated high maintenance. Claim 13 relates to a medical treatment unit with a device according to claim 1, which is designed as a disposable unit.

The device according to the invention may be part of a medical treatment device as recited in claim 14.

The use of the device according to the invention for the separation of blood into its components is covered by claim 15.

In the following the invention will be explained in more detail with reference to the drawings.

Show it:

1 shows a simplified schematic representation of the device according to the invention for the separation of blood,

2 shows a simplified schematic representation of the device according to the invention for the separation of blood with a housing enclosing the container,

3a-d: various embodiments of the device according to the invention in a simplified schematic representation.

Fig. 1 shows the device according to the invention for the separation of blood 1 in a simplified schematic representation.

The device for separating blood 1 has a container 2 and at least one storage and drive device 1 1. The storage and drive device 1 1 serves as a storage for the container 2 and as a magnetic drive, which is able to put the container 2 in rotation about its own axis.

The container 2 can be vertical or horizontal or oblique, i. be positioned in steps between these two orientations.

In very high containers can be mounted to stabilize against tilting at the other end of the container 2 with respect to the storage and drive device 1 1 an abutment.

The counter bearing can be designed purely mechanically as a guide. Also conceivable is a magnetic design of the anvil in alignment with the storage and drive device 1 1, so that here also a magnetically levitating and thus non-contact storage and, if necessary, an additional drive can take place.

The container 2 has at least one inlet 5, which is located at the at least one open end 3 of the container 2.

The open end 3 of the container 2 can in this case be completely open over the entire diameter of the container 2 or less. The resulting at a less wide opening of the container 2 projection 15 can serve as overflow weir 10 for the effluent blood plasma or serum 13, while the denser abgespartten_Blutbestandteile 14 are retained by them in the container 2.

At least one outlet 6 may also be provided at an open end 3 of the container 2.

The container 2 consists of a blood-compatible, dimensionally stable material, such as glass, metal or plastic. In the case of plastics, in particular polycarbonates have proven themselves. The use of thermoplastic or other blood-compatible and dimensionally stable plastics is also conceivable.

The container 2 has a preferably cylindrical shape, wherein the diameter 2a at least 10 mm and a maximum of 100 mm and the height 2b at least 20 mm and at most 900 mm, preferably 500 mm. Diameter 2a and height 2b can be varied and influence each other. If, therefore, the diameter 2a is reduced, the height 2b must increase and vice versa, so that both parameters are in a ratio which is appropriate for the result of the separation and the volume of the container 2 does not fall below a minimum value of 2 ml and a maximum value of 600 ml does not exceed.

The container 2 is in contact with at least one magnet 9. The magnet 9 can be releasably or firmly connected to the container 2 or be an integral part of the same. If the magnet 9 is detachably connected to the container 2 in one embodiment, it can be removed and reused before disposal of the container 2.

The magnet 9 may be located inside the container 2 or outside the container 2. If the magnet is mounted inside the container, it also represents a kind of overflow weir 10, so that the plasma already separates at this point. The process of separation is thus simplified.

If the magnet is attached to the outside of the container 2, then it can be advantageously stored in the disposal of the container 2 and used again.

Conceivable is the use of different types of magnets, such as a shell or disc magnet or a ring magnet that encloses the container 2 completely or partially, It is also possible to use several smaller magnets that are grouped at a defined distance on or in the container 2.

The blood contacting parts of the device may be reusable parts but must be cleaned after each use. Advantageously, therefore, all blood-bearing parts are designed as disposable items. These can be disposed of after use.

The inventive device has a storage and drive device 1 1, which builds up a magnetic field and at the same time serves as a storage for the container 2, so that the container is held magnetically levitating. The drive device can be operated electromagnetically. Also conceivable is a drive via rotating permanent magnets, compressed air or liquid.

In operation, the container 2 rotates, driven and suspended by the interaction between the magnetically generated by the bearing and drive device 1 1 magnetic field and the magnet 9, which is either connected to the container 2 or integrated into this, to his own axis.

The speed is in operation between 1000 and 50,000 revolutions per minute. The centrifugal force resulting from the rotation leads to the separation of the blood, which is introduced via the inlet 5 at the first open end 3 'or at the second open end 3 "into the container 2 and distributes on the inside to the wall of the rotating container 2. The separated Blood constituents 14 are distributed according to their density at a different radial distance to the wall of the container 2, while the blood plasma or serum 13 collects centrally in the container 2. The blood components and the blood plasma or serum 13 become due to the continuously trailing introduced blood pressed in the direction of the open end of the container 2.

Depending on the rotational speed, a plasma flow of 1 ml / min to 300 ml / min is achieved.

A bearing and drive device 1 1 of the type described is used for example by the company Levitronix for the drive of centrifugal pumps, which serve to promote a fluid.

In the case of magnetically levitating mounting, the position of the container 2 can be corrected via a control device 18 which controls the magnets in order to ensure a secure and precisely positioned mounting of the container 2 in the storage and drive device for the duration of the operation.

The mode of operation with regard to magnetic bearing and drive is described in detail in documents EP 0 900 572 and EP 0 819 330, the contents of which are hereby incorporated into the description, and is known to the person skilled in the art.

About the magnetic interaction and the resulting reluctance forces the container is stabilized to a certain extent against tilting.

In a particularly preferred embodiment, at least one sensor 16 is integrated in the device, via which together with an evaluation unit 17 a statement about the position of the container can be made.

The execution of the blood separation device according to the invention is also conceivable in the form of a disposable cassette as a medical treatment unit. The device according to the invention can be part of a medical treatment device.

The device according to the invention can be used to separate blood.

FIG. 2 shows a simplified schematic representation of the device according to the invention for separating blood with a housing 12 enclosing the container 2.

Advantageously, the container 2 can be enclosed by a housing 12. The housing 12 physically separates blood and blood components 14 from the storage and drive device 11. Should there be any unforeseen contamination of the environment of the container 2 when introducing or removing blood constituents 14 or even the container 2 itself has a defect, the user is protected from contact with possibly infectious material. Also, all cost-intensive components, such as the storage and drive device 1 1 of the container 2, not contaminated and can continue to be used.

Conversely, the blood to be treated and its constituents are also protected from contamination and sterility is thus preserved.

If the device is operated in the manner of an overflow centrifuge, the housing 12 can also serve as a collecting vessel for overflowing blood plasma or serum 13. It is conceivable to completely flood the space around the container 2 with blood plasma or serum 13.

If the housing 12 has an outlet 12a, blood plasma or serum 13 can be removed. The remaining in the container 2 blood components 14 are removed separately.

3a shows an embodiment of the device 1 according to the invention in a simplified schematic representation, in which the magnets 9 are located at the closed end 4 of the container 2. 3b shows an embodiment of the device 1 according to the invention in a simplified schematic representation, in which the magnets 9 are located at the closed end 4 of the container 2 and an assembly 7 with means for removing the blood components 8 from the at least one open end 3 of the container. 2 is recorded.

It is also conceivable that the assembly 7 is designed so that with this even individual blood components 14 can be removed, for example, by the edge of the assembly 7 at the inner edge of the container 2 adjacent the blood components 14 dissolves from this and transported to the outside.

In the assembly 7 can also be integrated 5 and / or outlet 6.

3c shows an embodiment of the device 1 according to the invention in a simplified schematic representation, in which the magnets 9 are mounted halfway up inside the container 2. In this embodiment, the container 2 has a first open end 3 'and a second open end 3 ".

The blood is introduced via the lower open end 3 ", the denser blood constituents collect during the rotation below the magnets 9 in the lower portion 2" of the container 2, while the less dense blood plasma or serum 13 overcomes the magnets 9 and into the moved upper portion 2 'of the container 2. The magnets 9 serve as overflow weir 10.

Fig. 3d shows an embodiment of the device 1 according to the invention in a simplified schematic representation, in which the magnets 9 are mounted externally on the container 2.

In addition to the embodiments described above, of course, further embodiments with variations of the mentioned features are conceivable. LIST OF REFERENCE NUMBERS

Device for separating blood (1); Container (2); upper section of the

Container (2 '); lower section of the container (2 "); diameter of the

Container (2a); Height of the container (2b); open end (3); first open end (3 '); second open end (3 "); closed end (4); inlet (5); outlet (6); assembly (7); means for removing the blood components (8); magnet (9);

Overflow weir (10); Bearing and drive device (1 1); Housing (12); Outlet of the housing (12a); Blood plasma / serum (13); separated blood components (14);

Projection (15); Sensor (16); Evaluation unit (17); Control device (18);

Rotation axis (19)

Claims

claims

1 . Device for separating blood into its components, comprising a magnetic drive device and a container which is rotated by the drive device about its own axis, wherein the container has at least one open end and in this at least one inlet, characterized in that the container is stored magnetically floating.

2. Apparatus according to claim 1, characterized in that

at least one outlet is provided in an open end of the container.

3. Device according to claim 1, characterized in that

the inlet and / or the outlet are integrated into an assembly received from the open end of the container and containing means for removing the separated blood components.

4. Device according to one of the preceding claims, characterized in that

the container consists of a blood-compatible, dimensionally stable material, preferably plastic and in particular polycarbonate.

5. Device according to one of the preceding claims, characterized in that

the container has a preferably cylindrical shape with a diameter of at least 10 mm and a maximum of 100 mm and a height of at least 20 mm and a maximum of 900 mm, preferably 500 mm, wherein both sizes influence each other, so that the volume does not have a minimum size below and does not exceed a maximum size.

6. Apparatus according to claim 1, characterized in that

the container is in contact with at least one magnet, wherein the magnet can either be detachably or fixedly connected to the container or can be a one-piece component thereof and is located on the outside of the container or in the interior of the container.

7. Device according to one of the preceding claims, characterized in that

the container is enclosed by a housing.

8. Device according to one of the preceding claims, characterized in that

all blood-carrying parts are designed as disposable items.

9. A method of separating blood into its components with a container according to claim 1, the method comprising the steps of:

Introducing blood into the container

Drive of the container for rotation about its own axis

Removal of the blood components

characterized in that

the container is held magnetically in suspension during the separation process.

10. The method according to claim 9, characterized in that the position of the container detected by at least one sensor and stabilized and / or corrected via an evaluation unit by means of a control device.

1 1. Method according to one of the preceding claims, characterized in that

the rotation speed is between 1000 and 50,000 revolutions per minute.

12. The method according to claim 12, characterized in that a plasma flow of 1 ml / min to 300 ml / min is achieved.

13. Medical treatment unit with a device according to claim 1, which is designed as a disposable unit.

14. Device for separating blood into its components as part of a medical treatment device.

15. Use of a device according to claim 1 for the separation of blood.