EP1043071A1 - Apparatus for centrifuging liquids and use of the apparatus - Google Patents

Abstract

A first coupling (16) is attached to the first driver, and a second coupling (11) to the centrifuge. An elastic means (18) h the two together. A movable controller (17) is connected to the elastic means to disengage the coupling. The second coupling als has a cam surface (11b) which exerts on the elastic means a greater and opposite force to that holding the couplings together. The centrifuge has coaxial first (1) and second (22) drivers mounted to pivot, means (23-33) of driving the first and secon drivers with a rotation ratio of 2/1 between them, a circular centrifuge (2) for the liquid which has at least three channels (4,5,6) connecting its center to a peripheral separation chamber (3), means (11-18) of coupling the centrifuge to the first driv and three channels (4a,5a,6a) made of elastically deformable material with one end fixed to each of the three channels in the centrifuge. These channels each form an open circuit around the centrifuge, with the second end coaxial with the first and fixed angularly. One channel is connected to the source of the liquid to be centrifuged and the other two act to recover the different density components produced by the centrifuge. One of the drivers has an axial passage at the internal end of which is a ball bearing. The other driver has a lug with a diameter and length corresponding to the passage. The part of the lug which fits into passage has an annular groove which is dimensioned to partially receive the ball bearing and a conical end. A tubular piston has end designed to receive the ball bearing and connected to the elastic means to press the piston axially towards the end of the passage near the ball bearing. This provides a centripetal pressure on the ball bearing in the annular groove. A tensioning elem is fixed to the piston to allow it to be displaced against the elastic means. A detector on one of the channels detects the puri of the liquid in the pipe. The detector is a light source and double prism, with a photoelectric detector to measure the angular value of the part of the double prism in the layer of blood cells. When the liquid reaches a certain purity, the elastic means a used to separate the centrifuge from the first driver. The liquid is pressurized to overcome pressure losses in the system.

Description

The present invention relates to a centrifuge apparatus liquid, especially blood, containing suspended particles comprising a first drive member rotatably mounted, a second drive member rotatably mounted, coaxial with the first drive member, means for training said first and said second drive member, with a rotation ratio of 2/1 between them, a member for centrifuging said liquid, with at least three channels connecting its center to a room separation device, means for rendering said centrifuge member integral with said first member drive, three conduits made of elastically deformable material, each having a first integral end from the central end of one of the three channels of said centrifuge member, these conduits each forming a open loop around said centrifuge member, the second end of this loop being substantially coaxial at the first and angularly fixed, a portion of each loop being kinematically integral with said second member one of said conduits being connected to a power source for said liquid to be centrifuged, both others used to recover components of different densities from centrifugation. This invention relates also to use this device.

Such centrifuge devices are well known especially in the field of blood centrifugation, since they allow to connect the centrifuge rotor outside to supply it with liquid to be centrifuged and remove the separate components without using seal. Indeed, it is known from US 3,586,413 that if you have a flexible duct forming an open loop and whose two ends are coaxial, that one is fixed while the other rotates at 2ω speed around the axis common to these two ends and that the loop is driven at speed ω, the flexible conduit rotates around its own axis at speed -ω, canceling the induced twist by the rotation of the rotor.

In the case of blood centrifugation, the separation must be changed for each donor or each different patient. Given the centrifugal forces required to obtain the desired separation of the constituents, the centrifuge rotor must be able to withstand the forces centrifugal to which it is subjected, it must be sized appropriately, it must be balanced to avoid unbalance and it must be fixed securely on the axle of rotation.

Different ways have been adopted to satisfy these requirements, one is to use a rotor integral with the centrifuge and drive system provide positioning means to receive one or more several centrifuge chambers. Such a solution is described for example in US 4,164,318.

Another solution described in US 4,834,890 consists to provide a rotor having an annular housing intended to receive a flexible bag serving as a separation enclosure. The placement of the bag in the annular housing is an extremely delicate operation. To give back this easier operation, we proposed in US 4,934 995 to make the rotor in two parts between which is provided the housing intended to receive the flexible bag for liquid separation.

Another system comprising a rigid rotor intended for receive a flexible bag for liquid separation a have been offered in US 4,007,871.

US 4,790,807 relates to a rigid enclosure but flexible formed by a split ring, both of which end are spread apart. To set up this speaker in the support rotor, the two ends are brought together of the split ring which is then retained in a housing of the rotor by its elasticity.

Finally, we have also proposed, in US 4,330,080 a rigid and disposable rotor in the form of a disc in two parts, one comprising two annular chambers for separation of constituents of different densities and channels to bring the liquid to centrifuge and to allow the evacuation of the constituents resulting from the separation.

The drive shaft of this rotor is constituted by a tubular element allowing the passage of the liquid conduits to centrifuge and constituents from the separation. The outside of the tube has an annular surface gear intended to engage a pinion of the mechanism device drive, a first profile disc convex is placed on one side of the annular toothed surface and is intended to engage with three guide pulleys with concave profiles. A second disc, placed on the other side of this toothed annular surface is engaged with three other guide rollers. Such a drive mechanism and guidance is extremely complex. To remove the disposable rotor, you must be able to spread one of the associated rollers to each of the guide surfaces, so that these rollers must also be mounted on mobile supports which must be locked during the centrifugation process. It is therefore a system in which change disposable rotor is not an easy operation, neither quick to achieve.

We can therefore see that it does not exist in this domain an assembly formed by a rigid separation enclosure forming a bowl and its supply conduits and which allows a quick and easy change.

The object of the present invention is to remedy, less in part to the disadvantages of the above-mentioned solutions.

To this end, this invention relates to an apparatus for centrifuging liquid, especially blood, of the type above, as defined by claim 1.

This invention also relates to a use of this centrifuge, as defined by claim 15.

The apparatus according to the invention is therefore of the type in which the circular centrifuge member forms a single disposable member, integral with the conduits used for feeding and the collection of liquids. The fixation of the organ circular centrifugation on its drive member is obtained by manual latching. The fixing system is not subject to centrifugal forces since it works axially. Once the attachment is obtained, there is therefore no risk of untimely separation. The dropout of the centrifuge unit requires only a simple pull axial against spring elastic pressure holding. No other mechanical element than the second coupling element is not located on the centrifuge member, so this one constitutes a simple piece and cheap to make. The simplicity and speed of centrifuge member change operations as well that the price of it therefore allow to realize a gain substantial, on the one hand on the price of the material, on the other share on the cost of centrifugation. This economy is extremely important especially when the device according the invention is used for the collection of plasma.

la figure 1 est une vue en coupe d'une élévation de cette forme d'exécution;

la figure 2 est une vue partielle en coupe, selon la ligne II-II de la figure 1,

la figure 3 est une vue schématique de la cinématique du mécanisme d'entraínement,

la figure 4 est une vue agrandie en coupe selon la ligne IV-IV de la figure 1,

la figure 5 est une vue partielle en coupe, d'une variante de la forme d'exécution de la figure 1,

la figure 6 est une vue selon la ligne VI-VI de la figure 5;

la figure 7 est une vue semblable aux figures 1 et 5 d'une autre variante.

The invention will be better understood on reading the following description of an embodiment and a variant of the liquid centrifugation apparatus according to the present invention, illustrated schematically and by way of example by the appended drawing in which,

Figure 1 is a sectional view of an elevation of this embodiment;

FIG. 2 is a partial sectional view, along the line II-II of FIG. 1,

FIG. 3 is a schematic view of the kinematics of the drive mechanism,

FIG. 4 is an enlarged sectional view along the line IV-IV of FIG. 1,

FIG. 5 is a partial sectional view of a variant of the embodiment of FIG. 1,

Figure 6 is a view along line VI-VI of Figure 5;

Figure 7 is a view similar to Figures 1 and 5 of another variant.

The centrifuge apparatus illustrated in FIG. 1, intended in particular for plasmapheresis, comprises a rotor centrifugation, having the shape of a disc 1 arranged at the end of a tubular body 1a, pivotally mounted in two ball bearings P1, P2. This centrifuge rotor 1 carries a disposable centrifuge bowl 2, formed itself by the union of two parts welded or glued one to the other, the lower one, formed by a disc 2a and the other upper 2b, having two cylindrical side walls and concentric, one inside 2c and the other 2d exterior between which an enclosure is formed separation ring 3 (Figures 1 and 2). Three channels radials 4, 5, 6, formed in the upper part 2b of the centrifuge bowl 2, connect this annular enclosure separation 3 in the center of this bowl 2. Channel 4 constitutes the blood supply channel to be centrifuged. he has a partition 7 which joins the side wall 2d of the annular separation enclosure 3, while the other wall of this feed channel 4 stops at the side wall internal 2c of this separation enclosure 3.

The partition 7 also serves to separate the channel 4 from the channel 5 intended for the recovery of blood cells, of which the other partition 8 stops at a certain distance from the 2d external side wall of the annular enclosure of separation 3. This partition 8 therefore separates channels 5 and 6 and communicates them respectively with the external party of the annular separation enclosure 3, that is to say that where the blood cells are concentrated, that of lower density where the plasma is concentrated. Of course, subsequent separation of the recovered blood cells is possible to separate red blood cells, red blood cells blanks and pads. In a variant of the bowl 2, we could also consider having more than two output channels to achieve this separation.

These three channels 4, 5 and 6 lead to the center of the bowl 2 where they are connected to three conduits 4a, 5a, respectively 6a (Figure 4) which are preferably arranged parallel in the same flexible tubular element 9. The portion of this tubular element 9, adjacent to its end connected to channels 4, 5 and 6 is held in a housing tubular 10 formed coaxially with the axis of rotation of the bowl 2, on the upper part 2b thereof. The sections of the three conduits 4a, 5a, 6a are elliptical, the major axes of these ellipses being tangent to at least one circle concentric with the longitudinal axis of the tubular element 9. This orientation of the elliptical sections of the conduits 4a, 5a, 6a, facilitates the rotation of the tubular element around its longitudinal axis.

It appears from the above that the movable part called to be discarded after each use does not consist that of three parts, the bowl 2 formed of two parts 2a, 2b welded or glued to each other and the tubular element 9. In addition, this set does not require any seal sealing. This set is removably connected to the centrifuge rotor 1 as described below.

The bottom of the disc forming the lower part 2a of the bowl 2 carries a coupling element constituted by a tenon or a cylindrical rod 11, having a groove 11a of semi-circular section, adjacent to one end frustoconical llb. This coupling rod 11 is engaged in a coupling element formed by a ring 12, of a coupling mechanism 13, this ring and this mechanism of coupling being housed in the tubular part la of the rotor 1.

The coupling mechanism 13 includes a coupling means which, in this embodiment, consists by a ring of balls 16 which is located at the end internal of the axial passage formed by the ring 12 secured to the tubular part 1a of the rotor 1. A tubular piston 17 is slidably mounted in the tubular part 1a. Its end upper ends with a funnel-shaped surface 17a. This tubular piston 17 is pressed axially against the inner end of the ring 12 by a spring helical 18 compressed between one end of the part the la of the rotor 1 and a bearing of the tubular piston 17. This axial pressure in the direction of the ring 12 and the funnel shape 17a have the effect of exerting forces centripetals on the crown of balls 16 which presses them into the groove 11a of the coupling stud 11 of the bowl 2.

To prevent these balls from engaging in the opening axial of the ring 12, when removing the post coupling 11, a second piston 14 is slidably mounted inside the tubular piston 17 and a second spring helical 19 pushes it axially against the end of the coupling member 11.

Alternatively, the ring of balls 16 could be replaced by a split ring-type spring piano, or by a coil spring forming a O-ring spring, both ends of which would then brought together by the funnel 17a under the coil spring pressure 18, thereby reducing its diameter to keep it engaged with the throat of the coupling stud.

The outer end of the tubular piston 17 is integral a gripping member 20 intended to allow exercise an axial traction opposite to the pressure of the spring 18, to allow the balls 16 to move outward. The piston 14 subjected to the axial pressure of the spring 19 can then eject the bowl 2 upwards and maintain simultaneously the spaced balls 16.

As can be seen in Figure 1, for ensure good tightening of the bowl 2 on the rotor 1, the upper surface of the disc carrying this bowl 2 has a slight clearance 1b, which ensures good contact with the peripheral annular surface of this disc. In addition, the axial position of the groove lla of the coupling stud 11 can be chosen to be normally still very partially in the axial passage of the ring 12 of so that the engagement of the balls 16 in this groove 11a induce a very slight deflection of the center of the bottom of the bowl 2, which allows the disengagement 1b of the rotor disk 1, thus ensuring sufficient contact between this disc and the bowl 2 to guarantee a friction drive of the latter. In case this friction is not sufficient, radial grooves could be provided for prevent the bowl 2 from sliding relative to the disc rotor 1.

The ball bearings P1, P2 of the tubular part la of the rotor are mounted in a support element 21 fixed to a plate 22, itself fixed to an upper disc 26 by four columns 15, two of which are located behind bowl 2 are visible in Figures 1 and 3, the other two being arranged symmetrically with respect to a drive shaft 23 parallel to the axis of the rotor 1. Thanks to this arrangement, the side of the centrifuge opposite the shaft training is free, allowing the introduction side of the bowl 2 and the positioning of the element tubular 9. This allows easy access to the centrifugation 2 and easily carry it out and its removal.

The drive shaft 23 is pivotally mounted through two ball bearings 24, 25, respectively integral with the plate 22 and the upper disc 26 located above the bowl 2. This upper disc 26 is integral with the drive shaft 27 of a motor 28, coaxial to the axis of rotation of the rotor 1. The end of the shaft 23 which extends above the disc 26 is integral with a satellite pinion 29 in engagement with a fixed pinion 30. The ratio between the diameters of the satellite pinion 29 and the fixed gear 30 is 1/1, so that if the speed of rotation of the plate 26 is ω, that of the shaft 23 around its axis is 2ω. The lower end of this shaft 23 carries a toothed pinion 31 connected by a toothed belt 32 to a toothed pinion 33, of the same diameter as the toothed pinion 31, so that the rotor 1 is driven at speed 2ω.

The flexible tubular element 9 forms an open loop one end of which 9a is fixed and coaxial with the pivot axis of the rotor 1. This end 9a is fixed and held in a 10 'tubular connector housing similar to housing 10 supporting the other end of this element tubular 9. Each of these tubular elements 10 and 10 ' presents a sort of funnel 10a, respectively 10'a (fig. 5) which gives support to this part of the element tubular 9 when subjected to centrifugal force. This loop passes through an opening 22a formed in the plate 22, so that it is driven around the pivot axis of rotor 1 at speed ω, while its end secured to the center of the bowl 2 is driven at speed 2ω and that the other end 9a is fixed, from so that the flexible element is entrained between these two ends at speed -ω around its longitudinal axis canceling out any accumulation of torsion between these two extremities. This principle is well known since US 3,586 413 of Adams. A support surface 22b secured to the plate 22 serves to limit the deformation of the tubular element 9 under the effect of centrifugal force. Guide parts of the tubular element 9 are preferably made of a material self-lubricating or low friction, such as as Oilamid®, bronze-Teflon® or Valflon®.

Downstream of the fixed end 9a of the tubular element 9, the three conduits 4a, 5a, 6a separate and the conduit of plasma 6a is associated with a flow control valve 34 depending on the position of the separation surface between plasma and blood cells in the separation chamber 3.

For this purpose, a double prism 3a is formed at the end top of the separation enclosure 3 and came in one piece with the upper part 2b of the bowl 2 during its injection. The portion of this double prism 3a which is covered by the separated blood cells of plasma by centrifugal force following rotation of bowl 2 is opaque, while the part which emerges in the plasma is transparent. An optical device 35 comprising a laser and a photoelectric detector is arranged opposite this prism 3a, so that the detector photoelectric receives the light reflected by the part of the double prism 3a which emerges in the transparent plasma. AT each revolution of bowl 2, a proportional duration signal at the angular value of the transparent area of double prism 3a is thus supplied to an amplifier 36 whose outlet is connected to the proportional valve 34. Depending on whether this transparent area increases or decreases, the amplifier 36 will control the proportional valve 34 so that it reduces, respectively so that it increases the section of the plasma evacuation duct 6a, making it possible to maintain by this adjustment, the balance between the flows in the outlet conduits 5a and 6a, depending on a flow rate input determined by the blood supply pump into the conduit 4a, itself determined by the venous pressure from the donor arm.

The dimensioning of the centrifuge bowl 2 and of the tubular element 9 forming the open loop are chosen to reduce the size, weight, the price and volume, both of this bowl 2 and of the whole centrifuge, including the dimensioning is essentially dependent on the diameter of the centrifuge bowl. If the diameter decreases, it is necessary to increase speed. The increase in this may be limited by increasing the height of the centrifuge chamber 3, so that the maximum flow resulting remains practically constant, this being determined by obtaining good cell sedimentation blood.

For example, the diameter of the bowl is 80 mm and its height is substantially equal to its radius. Such diameter corresponds to about a third of that of the rotors of separation of the state of the art. Therefore, the length of the open loop formed by the tubular conduit 9 therefore corresponds substantially to one third of the loops of the state of the art.

By reducing the radius of the bowl 2 and thus the length of the loop formed by the tubular conduit 9, the tensile force exerted on it by the centrifugal force to which it is subjected can be kept at a constant value. Instead of using three pipes of 4 mm in diameter we have a single tubular element 9 of 7 mm in diameter, so that the resulting section is the same, that is to say 0.38 cm ² . The material of the tubular element is plasticized PVC or silicone, the specific weight of which is 1.2 g / cm ³ , as in the prior art. Given that the length of the open loop of the tubular element 9 is reduced to a third of that of the prior art, the mass of this tubular element therefore also corresponds substantially to a third. The radius of the open loop is also reduced to almost a third.

The tensile force F exerted on this pipe corresponds to: F = mω 2 .R

In the state of the art we obtain with a loop speed of 1000 rpm (ω ≅ 100) corresponding to half the speed of the rotor which is 2000 rpm and with a loop radius of 0, 13 m, a force of: F = 0.014.100 2 .0.13 = 18.2N

In the case of the example according to the present invention, with a mass of 0.0046 Kg, a loop speed of 3000 rpm (corresponding to a rotor speed 1 of 6000 rpm) and a loop radius 0.045 m, the force is: F = 0.0046.300 2 .045 = 18.6 N

The value of the tensile forces is: σ = F / S = 18/38 = 0.47 N / mm 2

où r, rayon de l'élément tubulaire

et R, rayon de la boucle formée par cet élément tubulaire.

Since the value of the forces of alternating bending on the tubular element corresponds to: σ = Er / R

where r, radius of the tubular element

and R, radius of the loop formed by this tubular element.

The radius R being smaller in the case of the present invention, to decrease σ, it is therefore necessary to decrease r and E. In the example given, E = 4 N / mm ² and σ _rupture = 12 N / mm ² . In the case of bending corresponding to 1 million alternate bending, 5 _^1/2 hours of operation, this value is reduced by a factor of 5 to account for the additional fatigue, so that σ _rupture for bending stress alternating = 2.4 N / mm ² . σ = 4.3.5 / 30 = 0.47 N / mm 2 i.e. a safety factor of 2.4 / 0.47 ≅ 5

This sizing example shows that it is completely made possible to very significantly reduce the diameter of the separation enclosure without loss of performance and without increased constraints as far as some measures are taken to this effect. Now, this reduction in diameter reduces the size of the device so extremely important. This allows to have a device much more compact, lighter and less expensive to manufacture. This device taking up little space, we can install more devices on the same surface, which is important, especially in the case of trucks used for the plasma collection where space is limited.

By way of example, the rotating part according to the invention weighs about 600 g while the rotors of the devices of the state of the art weigh almost five times what weight. This is the reason why in the collection of blood, plasmapheresis is generally not performed directly, but the blood is collected in pockets flexible tubes which are then placed in very large centrifuges. In this case, it is no longer possible to return the donor has red blood cells. However, the time for the body reproduce the amount of red blood cells is long, which is why several months must necessarily separate two blood donations for the same donor, this which would not be necessary if red blood cells could be reinjected after separation. This is not possible only if the separation is done simultaneously with the blood test.

There are other types of machines that work with a disposable centrifuge bowl, but these require a rotating joint, leading to a more solution expensive and not allowing simultaneous feeding centrifuge liquid and component discharge separated, so it is necessary to alternate supply and discharge, leading to a large volume extracorporeal.

The importance of having centrifuges light and compact and especially loudspeakers disposable separators that can be produced at low cost is so obvious. The ease of changing these speakers or separation bowls is therefore also a need. Only the meeting of all of these conditions may replace current methods of plasma collection.

Another important aspect of this invention is in that the complete circulation of the liquid is obtained by the overpressure with which the blood is brought in the centrifuge dish 2. This overpressure must compensate for the pressure losses induced in the duct supply 4a as well as in the recovery conduits blood cells 5a and plasma 6a. To create this overpressure it is advantageously possible to use a pump peristaltic, intended to ensure the desired flow downstream of the separation. No peristaltic suction pump outgoing components is therefore not necessary, the regulation of the plasma flow being obtained by the regulating valve 34, controlled by its servo system according to the variation of position of the border between the plasma and blood cells.

Of course, if this device is particularly suitable for use to perform online plasmapheresis with the blood test, it can of course also be used in therapeutic applications. We was able to observe in fact that the tubular element 9 containing the three conduits 4a, 5a, 6a is calculated with a factor of security of 5 for continuous use exceeding 5 hours, which allows its use in all applications possible.

The apparatus which is the subject of the present invention can also be used for washing blood cells by introducing alternatively with suitable means known in the domain, the cells to be washed and a washing liquid. In variant, the washing liquid could be introduced by an additional conduit, allowing to simultaneously perform separation and washing. In this case, the element tubular 9 should then have four conduits instead of the three represented.

In the variant illustrated in FIGS. 5 and 6, the two discs 22 and 26 of the previous embodiment are replaced by two diametrical arms 22 ', 26' which are come from a single piece of aluminum with two pillars 37 and 38 diametrically opposed. The arm 26 'has a hub 26 'which is driven on the shaft 27 of the motor 28. The pillar 37 has a cylindrical passage 39 intended for the passage of the drive shaft 23. The other pillar 38 is integral a support 40 having a guide chute 41 of the tubular element 9.

Support 40 is designed to support the element flexible tubular 9 in the area where its radius is greatest large, therefore where the centrifugal force is most important. the funnel 10a supports the central part of the element tubular 9.

To reduce the friction between the trough 41 of the support 40 and the tubular element 9 during the rotation of the device, the support 40 is made, like the support 22b of the embodiment of FIG. 1, made of a material with low coefficient of friction. In addition to the materials already mentioned, we could also use a high weight polyethylene molecular (PEHMW). We can still encourage sliding using when manufacturing the tubular member 9, when the latter is made of PVC, a plasticizer based on silica making its surface more slippery. It is still possible reduce friction by reducing the surface area contact of chute 41 by streaks possibly in form of tendrils.

According to a last variant illustrated by FIG. 7, the rollers 42 have the support 40 in the chute freely rotated around axes parallel to that of the element tubular 9. These rollers 42 are driven by the rotation of the tubular element 9 on itself.

The rest of the centrifuge corresponds to the embodiment described above. The variant described in relation to Figures 5 and 6 facilitates balancing and increases the security of the device when rotates at centrifugation speed. It improves also guiding and supporting the tubular element 9, which is thus very little subjected to centrifugal force.

Claims (15)

Apparatus for centrifuging liquid, in particular blood, containing particles in suspension comprising: a first drive member (1) pivotally mounted, a second drive member (22) pivotally mounted, coaxial with the first drive member (1), means (23-33) for driving said first (1) and said second (22) drive member, with a rotation ratio of 2/1 between them, a circular centrifuge member (2) of said liquid, provided with at least three channels (4, 5, 6) connecting its center to a peripheral separation chamber (3), means (11-18) for making said centrifuge member (2) integral with said first drive member (1), three conduits (4a, 5a, 6a) of elastically deformable material, each having a first end integral with the central end of one of the three channels (4, 5, 6) of said centrifuge member (2), these conduits ( 4a, 5a, 6a) each forming an open loop around said centrifuge member (2), the second end of this loop being substantially coaxial with the first and fixed angularly, a portion of each loop being kinematically integral with said second drive member (22), one of said conduits (4a, 5a, 6a) being connected to a supply source of said liquid to be centrifuged, the other two serving to recover the components of different densities resulting from centrifugation, characterized in that first coupling means (16) are integral with said first drive member (1), second coupling means (11) are integral with said centrifuge member (2), elastic means (18) are provided for exerting a force tending to engage said first (16) and second (11) coupling means with each other, a mobile control member (17), integral with a gripping element (20) is connected to said elastic means (18) to release said coupling means (11, 16) from each other and in that said second coupling means (11) further comprises a cam surface (11b) for exerting on said elastic means (18) a force greater and in opposite direction to that which tends to engage one with the other said first (16) and second (11) coupling means, during the establishment of said centrifuge member (2) on said first drive member (1). Apparatus according to claim 1, characterized in that that one (1) of said members assembled by said means coupling (11, 16) comprises an axial passage (12) to a internal end of which a crown is arranged coaxially balls (16), than the other (2) of said coupling means has a pin (11) whose diameter corresponds to that of said axial passage (12) and the length of which exceeds that of this passage, the part of this tenon (11) making projection of this axial passage (12) having a groove annular (11a), dimensioned to receive partially said ring of balls (16) and adjacent to one end frustoconical (11b) of this stud (11) and in that a piston tubular (17), one end of which is funnel-shaped (17a) shaped to receive said crown of balls (16), is associated with said elastic means (18) for axially press this piston (17) towards the end of said passage (12) adjacent to said crown of balls (16) for applying this crown (16) by exerting on it a centripetal pressure in order to apply said balls (16) in said annular groove (lla), a member gripping (20) being integral with said tubular piston (17) to allow it to be moved against said means elastic (18). Apparatus according to claim 1, characterized in that that said first and second coupling means (1, 2) comprise, on the one hand, a split annular elastic element (16), arranged coaxially at an internal end of a axial passage (12) of this first drive member (1) whose section is less than the diameter of this element elastic (16) and a tubular piston (17), one end of which has a funnel shape (17a) shaped to receiving said element (16), said elastic means (18) axially pressing this piston (17) towards the end internal of said passage (12) to apply said split annular elastic element (16) by tightening it radially so that its internal diameter is less than that of said passage (12), a gripping member (20) integral said tubular piston (17) to move it against said elastic means and, on the other hand, a post (11) whose section is complementary to that of the said passage (12), this tenon (11) having a groove (lla), located at the outlet of said passage (12) to receive said split annular element (16) and adjacent to one end conical (llb) intended to allow the opening of this split annular element (16) during the introduction of this tenon (11) in said axial passage (12), to bring said groove (lla) opposite this split annular element (16) so to allow him to engage in it and to fix this organ of centrifugation (2) to the drive member (1) and in that that a gripping member (20) is integral with said piston tubular (17) to allow it to be moved against said elastic means (18). Apparatus according to claim 2, characterized in that a second piston (14) is slidably mounted inside of said tubular piston (17), elastic means (19) pushing this second piston (14) towards the end internal of said axial passage (12), the stroke of this second piston (14) being chosen to make it penetrate into said axial passage (12) during the separation of said member centrifugation (2) of said first drive member (1) and retaining said ring of balls (16) in said funnel (17a) of said tubular piston (17). Apparatus according to claim 4, characterized in that that the pressure exerted on the second piston (14) by said elastic means (19) is capable of ejecting said member centrifugation (2) during the separation of said first and second coupling means. Apparatus according to one of the preceding claims, characterized in that one (6a) of said conduits intended to be connected to a collector of one of the components from the centrifugation comprises a proportional valve (34), detection means (35) being arranged upstream of this conduit to measure the purity of the component in front flow through said conduit, this detector being connected to said proportional valve (34) for regulating the flow in said conduit (6a) as a function of said measured degree of purity. Apparatus according to claim 6, characterized in that that a double prism (3a) is disposed in said chamber separation (3), said detection means (35) comprising a fixed light beam relative to said organ of centrifugation (2) directed in the trajectory of this double prism (3a) and a photoelectric detector to measure the angular value of the portion of this emerging double prism of the layer of blood cells in the plasma and deliver to a control member (36) of said proportional valve (34), a signal characteristic of this angular value. Apparatus according to one of the preceding claims, characterized in that a space is provided laterally to said first and second drive members (1, 22) to allow the passage of said centrifuge member (2). Apparatus according to one of the preceding claims, characterized in that said circular centrifuge member (2) comprises two parts (2a, 2b) assembled one at a the other in a sealed manner and that said three conduits (4a, 5a, 6a) form a single tubular element, in which three separate conduits are provided, one end of this element tubular being tightly fixed coaxially to the axis of rotation of said centrifuge member (2). Apparatus according to one of the preceding claims, characterized in that the parts of the apparatus in contact with said tubular element (9) are made of a material self-lubricating or low coefficient of friction. Apparatus according to one of the preceding claims, characterized in that it comprises a fourth conduit two of which are respectively connected to a pressure source of red blood cells and the other to a pressurized source washing fluid for these red blood cells. Apparatus according to one of claims 1 to 10, characterized in that one of said conduits (4a, 5a, 6a) is alternately connected to a pressurized source of blood cells red and to a pressurized source of wash fluid these red blood cells. Apparatus according to one of the preceding claims, characterized in that said second drive member (22 ') and an element (26'), integral with the means (27, 28) to train this second drive member form one and the same room. Apparatus according to one of claims 1 to 3, characterized in that radial grooves for increasing the frictional force are provided on at least one of the surfaces in contact with said first drive member (1) and said centrifuge member (2) Use of the centrifuge according to one of the preceding claims, characterized in that the liquid to be centrifuged is put under a selected pressure to overcome pressure drops and ensure the desired flow of said liquid.

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