Mounting device for a filter unit for a biological fluid

Description

[0001] The present invention relates to a device for holding a filtration unit as well as an assembly comprising said holding device and said filtration unit.

[0002] The invention applies to the field of medical devices and in particular to medical devices intended for the filtration of blood or a blood component.

[0003] Whole blood consists of two types of components: blood cells, including red blood cells, white blood cells, and platelets, and plasma, a pale yellow liquid in which the blood cells are suspended. Currently, only the blood components needed by patients are transfused.

[0004] In blood processing centers, these different blood components are generally obtained by centrifugation: a donor's whole blood is collected in a primary bag of a bag system. Then, the bag system is placed in a centrifuge to separate the blood contained in the primary bag into blood components such as a packed red blood cells (PRBCs) and either platelet-rich plasma (PRP) or platelet-poor plasma (PPP) and a buffy coat.

[0005] The bag system is then placed in a blood component separation and extraction device such as that described in document EP 2 869 864 A1. In this separation device, the primary bag containing the separated blood components is compressed so as to extract, for example, the red blood cell concentrate from the primary bag to a first satellite bag and the plasma from the primary bag to a second satellite bag of the bag system.

[0006] In addition, in the field of transfusion, it is classic to treat blood or blood components to remove undesirable substances such as leukocytes, pathogens, certain proteins - for example prion - and / or substances used in processes of inactivation, reduction and / or elimination of pathogens.

[0007] To remove these undesirable substances by filtration, a filtration unit is used in which a filtration medium capable of removing undesirable substances from the fluid is enclosed.

[0008] These filtration units are generally integrated into the bag systems described above, allowing for the treatment of blood and blood components in a closed circuit.

[0009] There are two main categories of filtration units: so-called flexible filtration units comprising a flexible outer casing, and so-called rigid filtration units comprising a rigid casing.

[0010] With rigid filtration units, during the centrifugation step to separate blood components, there is a risk not only that the rigid filtration units will be damaged but also that these rigid filtration units will damage adjacent bags, rendering bag systems unusable and possibly contaminating the external environment and the user.

[0011] Flexible filtration units, such as the one described in EP-A-526678, prevent damage to bag systems during centrifugation. However, with this type of flexible filtration unit, a pressure drop occurs during filtration due to the resistance of the filter medium, leading to swelling of the inlet compartment of the filtration unit and increasing fluid loss within the unit.

[0012] Finally, two types of filtration are distinguished: gravity and pressure filtration. Gravity filtration involves filtering blood or blood components by simply suspending the bag system with the filtration unit from a stand. Pressure filtration, for example, is performed simultaneously with extraction during separation by a separation device as described above.

[0013] In the case of plasma filtration, pressure filtration has the following advantages: the bag system has one less bag since the plasma transfer bag before filtration is no longer necessary, the installation of the system in the centrifugation pots is thus facilitated, the filtration time is shorter and the use is simpler since it is not necessary to suspend the bags from a stand.

[0014] However, pressure filtration with a flexible filtration unit increases the drawbacks associated with this type of unit: the pressure difference due to the resistance of the filtration medium is greater, as is the swelling of the filtration unit and the associated blood loss. Therefore, conformers for filtration units have been developed.

[0015] For example, document JP2001149444 describes several rigid support designs for flexible filters to prevent filter swelling.

[0016] In an initial embodiment of document JP2001149444, the filter support comprises two parallel flat walls separated by a distance equal to or greater than the filter thickness. The support also includes notches for the filter's inlet and outlet tubes. With this type of support, it is difficult to slide the filter between the two walls, particularly when the filter thickness is substantially equal to the distance between the two walls. Furthermore, increasing the distance between the two walls of the filter support to facilitate filter insertion results in insufficient filter compression to limit the volume of fluid loss within the filter.

[0017] Document JP2001149444 provides an alternative support embodiment in which the two sides of the support pivot relative to each other around a hinge, allowing the support to be opened and closed. A fastening element is provided on each side for closing the support.

[0018] Document WO 03 / 033066A2 also discloses a hinged filter holder whose flat walls are held in a closed position by means of a removable lock.

[0019] The disadvantage with this type of hinged filter support is the risk that the wall fixing element will not withstand the pressure exerted by the expansion of the filter during pressure filtration and will open during filtration.

[0020] Indeed, the filtration pressure is directly related to the difference in elevation between the blood bag to be filtered and the filtered blood bag. For example, for a difference in elevation of 1.2 m, the filtration pressure is approximately 0.12 bar. In a separation and extraction device, the filtration pressure can be almost three times higher and can reach approximately 0.3 bar.

[0021] The retaining device according to the invention makes it possible to overcome these drawbacks by providing a retaining device that is easy to use and can withstand high filtration pressures.

[0022] According to a first aspect, the invention relates to a device for holding a biological fluid filtration unit comprising a first plate and a second plate movable relative to each other between an open state in which the first plate and the second plate are separated from each other in order to be able to place said filtration unit in said holding device, and a closed state in which the first plate and the second plate are opposite each other in order to hold said filtration unit tightly, said holding device further comprising a fastening element movable between a free position in which the first plate and the second plate are free to move between the open state and the closed state and a locking position in which the first plate and the second plate are held in the closed state,said retaining device further comprising a locking element configured to hold the fastening element in said locked position.

[0023] According to a second aspect, the invention relates to an assembly comprising a holding device according to the first aspect of the invention and a filtration unit.

[0024] The attached drawings illustrate the invention: [ Fig.1 [ ] represents a perspective view of the device for maintaining the invention in an open state, in which a filtration unit is placed. ] Fig.2 ] represents a perspective view of the device for maintaining the figure 1 in a closed state and in which a filtration unit is placed. Fig.3 ] represents an exploded view of the various elements of the device for holding the figure 1 . [ Fig.4 ] represents a perspective and bottom view of the fastening element of the retaining device figure 1 . [ Fig.5 ] represents a perspective view of the outer face of the first plate of the retaining device of the figure 1 . [ Fig.6 ] represents a schematic view of a bag system comprising a filtration unit that can be held by the holding device of the figure 1 .

[0025] The invention relates to a device for maintaining a filtration unit of a biological fluid, such as blood or a blood component, in particular blood plasma.

[0026] In connection with the figures 1 à 3 , the retaining device 1 comprises a first plate 2 and a second plate 3 movable relative to each other between an open state ( figure 1 ) in which the first plate 2 and the second plate 3 are separated from each other in order to allow a filtration unit 4 to be placed in said holding device 1, and a closed state ( figure 2 ) in which the first plate 2 and second plate 3 are opposite each other and hold said filtration unit 4 tightly.

[0027] In particular, the filtration unit 4 comprises a flexible casing containing a filtration medium designed to retain undesirable substances from the blood, such as leukocytes. The filtration unit 4 further comprises an inlet tube 24 for the fluid to be filtered and an outlet tube 25 for the filtered fluid.

[0028] In the open state, the first plate 2 and the second plate 3 are sufficiently far apart to allow easy positioning of the filtration unit 4 on the first plate 2.

[0029] In the closed state, the first plate 2 and the second plate 3 are substantially parallel to each other.

[0030] In a particular configuration, the first plate 2 and the second plate 3 are separated by a distance less than the thickness of the filter unit 4. The distance between the first plate 2 and the second plate 3 is determined so that, when plates 2 and 3 are in the closed state, the filter unit 4 is tightly clamped to prevent swelling but not completely compressed, thus allowing the fluid to be filtered to flow through the filter unit. Limiting the swelling of the filter unit that occurs during filtration reduces the volume loss of the fluid to be filtered.

[0031] In a particular configuration, the first plate 2 and the second plate 3 are connected to each other by a joint formed by a hinge 5.

[0032] In particular, the hinge 5 is formed by a first cylindrical part 6 arranged on the first plate 2 and a second cylindrical part 7 arranged on the second plate 3, said first and second cylindrical parts 6, 7 cooperating to align themselves. The first cylindrical part 6 and the second cylindrical part 7 are joined by a pin 8 forming an axis of rotation, which passes through the first and second cylindrical parts 6, 7.

[0033] The retaining device 1 further includes a movable fixing element 9 between a free position ( figure 1 ) in which the first plate 2 and the second plate 3 are free to move between the open state and the closed state and a blocking position ( figure 2 ) in which the first plate 2 and the second plate 3 are held in the closed state.

[0034] According to a particular configuration and as shown in the figures, the fastening element 9 includes a part having a slot 10 designed to receive at least a portion of said first plate 2 and said second plate 3 when they are in the closed state.

[0035] More specifically, the part of the fixing element 9 is formed of a first plate 11 and a second plate 12 facing each other, connected to each other by a base 13. To keep the first plate 2 and the second plate 3 in the closed state, the first plate 11 and the second plate 12 are separated by a distance substantially equal to the thickness of the first plate 2 and the second plate 3 in the closed state with the filter unit held tight in the holding device.

[0036] As shown in the figures, the fastening element 9 is configured to pivot between the locked position and the free position. For this purpose, the fastening element 9 includes, at one end, a rod 14 forming an axis of rotation. The rod 14 is arranged at one end of the fastening element 9, between the first plate 11 and the second plate 12.

[0037] The first plate 2 includes a pivot 15 designed to support the rod 14 of the fixing element 9 and thus allow the pivoting of said fixing element 9.

[0038] The retaining device 1 further includes a locking element 16 configured to hold the fastening element 9 in the locked position illustrated in the figure 2 .

[0039] According to a particular configuration, the locking element 16 comprises a female part formed of an orifice 17 and a male part formed of a tab 18 provided with a lug 19, said female part and said male part cooperating so that the lug 19 engages in the orifice 17 of the female part.

[0040] In the figures, the female part is arranged on the second plate 12 of the fixing element 9 and the male part is arranged on the second plate 3 of the retaining device 1.

[0041] When the lug 19 is engaged in the orifice 17, the female and male parts of the locking element 16 are locked, placing the fixing element 9 in the locking position.

[0042] The tab 18 is deformable to allow the locking element 16 to be unlocked by pressing on said tab 18 in order to disengage the lug 19 from the orifice 17.

[0043] Thanks to the special arrangement of this locking element 16, when the fixing element 9 changes from the open state to the closed state, the locking element 16 simultaneously changes from the free position to the locking position.

[0044] Advantageously, the locking element 16 and the filter unit 4 are superimposed when the filter unit is placed in the retaining device in the closed position. Thus, during filtration, the flexible filter unit tends to inflate and exerts pressure on the tab 18 of the locking element 16. This pressure ensures that the lug 19 remains engaged in the orifice 17 throughout the filtration process.

[0045] In connection with the figures 1 And 3 , each of the first and second plates 2,3 include on their inner face cavities 20,21,22,23 configured to receive inlet tubes 24 and outlet tubes 25 of the filtration unit 4.

[0046] The terms "internal" and "external" are defined in relation to the retaining device in the closed state. The internal face of a plate faces the inside of the retaining device. The external face of a plate is the face visible from the outside.

[0047] More specifically, the first plate 2 comprises a first cavity 20 and a second cavity 21 designed to receive the inlet tube 24 and the outlet tube 25 of the filtration unit 4, respectively. The second plate 3 comprises a third cavity 22 and a fourth cavity 23 designed to receive the inlet tube 24 and the outlet tube 25 of the filtration unit 4, respectively. The third cavity 22 and the fourth cavity 23 are opposite the first cavity 20 and the second cavity 21, respectively, when the retaining device is in the closed state.

[0048] The cavities 20, 21, 22, 23 allow the filtration unit 4 to be held tightly between the first plate 2 and the second plate 3 without compressing the inlet tubes 24 and outlet tubes 25. Thus, the fluid flows into the filtration unit 4 even when the filtration unit is held tightly in the holding device.

[0049] To facilitate the installation and holding of the filtration unit in the holding device, one of the first plate 2 or second plate 3 includes at least one projection 26, 27, 28, 29 cooperating with at least one notch 30, 31, 32, 33 provided on the other of the first plate 2 or second plate 3.

[0050] According to the figure 3 , a first pair of projections 26,27 is arranged on the first plate 2 and frames the first cavity 20 intended to receive the inlet tube 24 of the filtration unit 4. The first plate 2 further includes a second pair of projections 28,29 framing the second cavity 21 intended to receive the outlet tube 25 of the filtration unit 4.

[0051] A first pair of notches 30,31 frames the third cavity 22 and faces the first pair of projections 26,27. In addition, a second pair of notches 32,33 frames the fourth cavity 23 and faces the second pair of projections 28,29.

[0052] Advantageously, the inner face of the first plate 2 or the second plate 3 includes an imprint 34 of the filtration unit 4. This imprint 34 marks the location of the filtration unit 4 in the retaining device 1 and helps the user to correctly position the filtration unit 4.

[0053] On the figure 3 , the inner face of the first plate 2 includes an imprint 34 of the filtration unit.

[0054] Advantageously, the retaining device 1 is transparent in order to visualize the flow of the fluid in the filtration unit.

[0055] The retaining device is made of a rigid thermoplastic material such as polycarbonate or an acrylonitrile butadiene styrene copolymer.

[0056] According to one embodiment, the elements of the retaining device 1, namely the first plate 2, the second plate 3, and the fixing element 9, are produced by injection molding and then assembled together. The pin 8 is advantageously made of metal.

[0057] As shown on the figures 2 And 5The external faces of the first plate 2 and the second plate 3 each comprise a plurality of recesses 35, 36, respectively. These recesses ensure good rigidity and resistance to pressure while minimizing the amount of material in the retaining device.

[0058] The use of the support device is described below. figures 1 à 5 .

[0059] Initially, the first plate 2 and the second plate 3 of the retaining device 1 are in the closed state ( figure 2 ). The user presses the lug 19 of the locking element 16 to unlock the fixing element 9 from its locking position and simultaneously rotates the fixing element 9 into its free position. The user then rotates the second plate 3 around the hinge 5 to put the first plate 2 and the second plate 3 in the open state ( figure 1 The user then places the filter unit 4 onto the indentation 34 of the first plate 2 and rotates the second plate 3 again to bring the first plate 2 and the second plate 3 into the closed position, with the filter unit 4 in the retaining device 1. The user rotates the retaining element 9 around the rod 14 to move it from the free position to the locked position, thus locking the first plate 2 and the second plate 3 in the closed position. Simultaneously, as the retaining element 9 moves into the locked position, the lug 19 engages in the opening 17 of the locking element 16. Filtration of the fluid through the filter unit 4 can then begin.

[0060] At the end of the filtration process, the user presses the lug 19 of the locking element 16 again to release the retaining element 9 from its locking position. The user rotates the retaining element 9 around the rod 14 to move it into the free position. The user then rotates the second plate 3 to open the retaining device 1 and allow the filtration unit 4 to be removed from the retaining device 1.

[0061] After removing the filter unit 4, the retaining device 1 is closed again with the fastening element 9 in the locked position as described previously. Alternatively, the retaining device is left open until the next use.

[0062] This support device is reusable to support other filtration units.

[0063] According to a second aspect, the invention relates to an assembly comprising a holding device according to the first aspect of the invention and a filtration unit.

[0064] In particular, the filtration unit 4 comprises a flexible casing containing a filtration medium. The retaining device specifically prevents the filtration unit from swelling during the filtration of a fluid through said filtration unit.

[0065] There figure 6 The diagram shows a bag system 37 comprising a filtration unit 4 that can be retained in the holding device 1 described above. The bag system 37 further comprises at least one filtrate collection bag 39 corresponding to the first satellite bag of the bag system described below.

[0066] The 37 pocket system of the figure 6is designed to collect whole blood and prepare leukoreduced plasma and leukoreduced red blood cell concentrate.

[0067] The bag system 37 includes a primary bag 38 for receiving whole blood collected from a donor. This primary bag is connected via a first satellite bag 39 through a first tube 40, a second satellite bag 41 through a second tube 42, and a collection needle 43 through a third tube 44. The second satellite bag 41 is also connected via a third satellite bag 45 through a fourth tube 46. The first tube 40 includes a filtration unit 4 for removing leukocytes from the blood plasma. The fourth tube 46 includes another filtration unit 47 for removing leukocytes from a red blood cell concentrate.

[0068] In a particular embodiment, the first satellite bag 39 is intended to collect leukoreduced blood plasma, the second satellite bag 41 is intended to collect red blood cell concentrate and the third satellite bag 45 is intended to collect leukoreduced red blood cell concentrate.

[0069] An example of the use of the pocket system and the retention device is described below.

[0070] Donor blood is collected in the primary bag 38 via the collection needle 43. The bag system 37 is placed in a centrifuge to separate the blood in the primary bag 38 into a lower layer comprising the red blood cell concentrate and an upper layer comprising the plasma.

[0071] The 37-bag system is mounted on a blood component separation and extraction device, such as the one described in the document

[0072] EP 2 869 864 A1. The flexible filtration unit 4 is housed in a retaining device 1 as described above.

[0073] The separation and extraction device compresses the primary bag 38 so as to transfer the plasma into the first satellite bag 39 via the filtration unit 4 and the red blood cell concentrate into the second satellite bag 41. The satellite bag 3.9 then contains the leukoreduced plasma.

[0074] Finally, the bag system 37 is removed from the separation and extraction apparatus and the second satellite bag 41 is suspended so as to filter by gravity the red blood cell concentrate through the other filtration unit 47. The leukoreduced red blood cell concentrate is collected in the third satellite bag 45.

Claims

1. Holding device (1) for a biological fluid filtration unit (4) comprising a first plate (2) and a second plate (3) that are movable in relation to each other between an open state in which the first plate (2) and the second plate (3) are remote from each other in order to be able to arrange said filtration unit (4) in said holding device (1), and a closed state in which the first plate (2) and the second plate (3) are facing each other in order to hold said filtration unit (4) clamped, said holding device (1) further comprising a fixing element (9) movable between a free position in which the first plate (2) and the second plate (3) are free to move between the open state and the closed state and a blocking position in which the first plate (2) and the second plate (3) are held in the closed state, characterized in that it further comprises a locking element (16) configured to hold the fixing element (9) in said blocking position.

2. Holding device according to claim 1, characterized in that the fixing element (9) comprises a part having a slot (10) designed to receive at least a portion of said first plate (2) and said second plate (3) when they are in the closed state.

3. Holding device according to claim 2, characterized in that said part is formed by a first small plate (11) and a second small plate (12) facing each other and connected to each other by a bottom (13), said first plate (11) and said second plate (12) being separated by a distance equal to the thickness of the first plate (2) and the second plate (3) in the closed state with the filtration unit held clamped in said holding device.

4. Holding device according to any one of claims 1 to 3, characterized in that the fixing element (9) is configured to pivot between said blocking position and said free position.

5. Holding device according to any one of claims 1 to 4, characterized in that the fixing element (9) comprises, at one end, a rod (14) forming an axis of rotation.

6. Holding device according to claim 5, characterized in that the first plate (2) comprises a pivot (15) designed to support the rod (14) of the fixing element (9).

7. Holding device according to any one of claims 1 to 6, characterized in that the locking element (16) comprises a female part formed by an orifice (17) and a male part formed by a tongue (18) provided with a lug (19), said female part and said male part cooperating so that the lug (19) engages in the orifice (17) of the female part.

8. Holding device according to claim 7, characterized in that the tongue (18) is deformable to allow unlocking of the locking element (16).

9. Holding device according to any one of claims 1 to 8, characterized in that the first plate (2) and the second plate (3) are connected to each other by a joint formed by a hinge (5).

10. Holding device according to any one of claims 1 to 9, characterized in that each of the first plate (2) and the second plate (3) comprises on their inner face cavities (20, 21, 22, 23) configured to receive inlet (24) and outlet (25) tubes of the filtration unit (4).

11. Holding device according to any one of claims 1 to 10, characterized in that one of the first plate (2) or the second plate (3) comprises at least one projection (26, 27, 28, 29) cooperating with at least one notch (30, 31, 32, 33) provided on the other of the first plate (2) or second plate (3).

12. Holding device according to any one of claims 1 to 11, characterized in that an inner face of the first plate (2) or the second plate (3) comprises an imprint (34) of the filtration unit (4).

13. Assembly comprising a holding device (1) according to any one of claims 1 to 12 and a filtration unit (4), characterized in that said filtration unit (4) comprises a flexible envelope enclosing a filtration medium.

14. Assembly according to claim 13, characterized in that the filtration unit (4) is comprised in a bag system (37) further comprising at least one filtrate collection bag (39).