Systems and methods for processing hemorrhagic fluids for autologous transfusion

Abstract

The present invention relates to a method for treating a hemorrhagic fluid contained in a container by filtration for subsequent autologous transfusion, the method comprising at least one step of concentrating by filtering the hemorrhagic fluid in order to increase the concentration of red blood cells in the hemorrhagic fluid so as to reach a target hematocrit level, while removing a filtrate comprising compounds not required for autologous transfusion from the hemorrhagic fluid, characterized in that the method further comprises the following steps: - a preliminary step which measures the hematocrit level of the hemorrhagic fluid; and - a dilution step which comprises adding a determined volume of dilution liquid to the volume of the hemorrhagic fluid to be treated, the determined volume of dilution fluid being calculated based on the measured hematocrit level and the target hematocrit level of the hemorrhagic fluid. The present invention also relates to a corresponding system for treating a hemorrhagic fluid by filtration.

Description

Technical field

[0001] The present invention relates to the field of treating hemorrhagic fluids, such as blood, for autologous transfusion of a patient, especially during a surgical intervention. Background art

[0002] Autologous transfusion, that is to say, the introduction of his or her own blood into the patient's body, is increasingly used during surgical interventions because it avoids the incompatibilities that may exist with homologous or allogeneic transfusion (that is to say, transfusion from the blood of another person), and it significantly prevents the transmission of infectious diseases.

[0003] In the case of intraoperative autologous transfusion, it is advisable to be able to convey almost continuously the blood collected directly from the patient, that is to say, by significantly limiting the dead time due to blood treatment, which is carried out using a treatment device independent of the patient. However, during collection, in a known manner, these bloods that are already diluted under operating conditions must also be supplemented with an anticoagulant so as to be able to be treated by the autologous transfusion device and to maintain their transfusion quality and the functionality of the blood components. These measures seem necessary because the use of a carrier fluid for the collected hemorrhagic blood can thus protect the red blood cells from direct physical trauma during mechanical contact with filters and other tubes. This dilution in the carrier fluid also reduces the contact of the red blood cells with air, thus greatly limiting their hemolysis. Finally, it can also control and prevent the coagulation activity of the blood and avoid the formation of blood clots that cannot recover the blood components, especially red blood cells. The recovered blood must then be conveyed to the patient in order to compensate for the loss of blood volume, but important problems are encountered. In fact, in the case of conveying a volume of blood that is too dilute, for the same reasons, these excessive volumes of transfusion fluid and the hypocoagulable syndrome can lead to a phenomenon of hypervolemia, and / or if not clean, an excessive volume of transfusion fluid with anticoagulant can also lead to a phenomenon of hypervolemia.

[0004] Furthermore, during the autologous transfusion of blood collected directly and only anticoagulated and blood-diluted, it is possible to convey activated or degraded biological substances that can cause secondary effects. It is possible to find, for example, histamine, kallikrein or kinins, more or less degraded plasma factors, which are preferably removed or replaced by small proteins and other cell debris resulting from cell trauma.

[0005] For intraoperative autologous blood transfusion conditions, the treatment of the blood thus consists of collecting the blood, anticoagulating it while collecting (which results in dilution), then pre-filtering the blood in a pre-filtering tank and treating the blood through a treatment device in order to separate the liquid phase from the phase containing the cellular components, so that on the one hand the collected and intended-to-be-transported phase can be concentrated, and on the other hand the liquid phase to be eliminated can be collected. It is recommended that these steps be completed as quickly as possible because, under intraoperative conditions, the patient usually requires emergency blood transfusion.

[0006] Different more or less complex and efficient techniques have been developed for autologous blood transfusion of patients during surgical interventions.

[0007] For example, there are autologous blood transfusion systems based on centrifugation techniques. Centrifuging the blood collected in autologous blood transfusion separates red blood cells (RBCs), platelet-rich plasma (PRP), and proteins. Therefore, it is not possible to obtain a high platelet recovery rate by this method.

[0008] In addition, in order to make the process proceed quickly, intensified centrifugation can be carried out, but then a layer called the buffy coat, which is a mixture of platelets and white blood cells (WBCs), will form at the interface between the red blood cells and the plasma. Therefore, this layer is not suitable for direct blood transfusion.

[0009] Therefore, complementary treatment is necessary to recover platelets and eliminate unwanted components, such as the buffy coat. In addition, when the centrifugation is too strong, platelets will be eliminated, resulting in a decrease in the quality of the concentrate to be transported.

[0010] The vacuum aspiration of blood and biological fluids by surgeons causes trauma to red blood cells, resulting in mechanical hemolysis of the most fragile cells. Centrifugation, a known and widely used autologous blood transfusion mechanism, also causes slight mechanical hemolysis. During the process of treating blood by centrifugation during surgery, red blood cells are thus traumatized, resulting in severe hemolysis, and the hemolysis rate can be as high as 19%. In the emergency mode (intensifying centrifugation to reduce the treatment time), this hemolysis level can reach 33%.

[0011] An alternative method to the current one used for intraoperative blood treatment by centrifugation is needed because, in addition to the hemolysis problem, centrifugation also eliminates most platelets (the recovery rate is less than 10%). This direct loss of the relevant cells that directly leads to primary hemostasis (platelet aggregation at the wound level) is problematic during surgery, which is easy to understand. This is why when the loss is too large, doctors resort to transfusing unstable blood products containing one or more homologous platelet concentrates. Therefore, a method that can preserve and transport the patient's platelets (preferably with a recovery level greater than 50%) would be desirable.

[0012] Accordingly, alternative autologous blood transfusion systems based on membrane filtration devices have been developed. For example, this is the case for the autologous blood transfusion systems described in Patent US 4,886,487, Patent US 5,215,519, Patent Application US 2003 / 229302, and International Applications WO 93 / 01858 and WO 98 / 29149. These systems are advantageous because they are capable of truly separating the components that are not required for blood transfusion without eliminating important components such as platelets as in the case of the centrifugation process. However, such systems have some drawbacks, especially in terms of efficiency.

[0013] Cells (RBC, WBC, and platelets) exhibit important membrane deformability, enabling them to pass through microvessels or wounds. However, during membrane filtration, a decrease in filtration flow rate can be observed throughout the process. The flow rate decrease can be explained by several factors, namely adsorption, steric hindrance, the effect of viscosity, pore blockage and clogging, and the concentration gradient at the membrane / solution interface.

[0014] In the case of filtration, the pore size and the hydrophilicity of the material must be controlled to allow these cells to pass through or not. In the case of using a membrane with a pore diameter less than 10 μm (especially less than 1 μm), in pre-filtration, it is inevitable that the membrane will be clogged by cells, so tangential filtration is necessary. Platelets also have high adhesiveness after activation and tend to adsorb on the membrane surface or plasma proteins and clog the membrane.

[0015] Tangential filtration is affected by the amount of material that can pass through the membrane per unit time, which generally limits the processing speed. This is referred to as the transmembrane flow rate or filtration coefficient. However, a patient suffering from massive bleeding cannot increase their opportunity loss coefficient due to a longer filtration time. Therefore, it is crucial that the time for processing blood during surgery through filtration should be comparable to that of the conventional centrifugation method, in which for a 500 ml volume of collected blood, the separation of red blood cells and plasma can be completed in a rapid time of 4 - 6 minutes.

[0016] Similarly, for the processing time, the performance of processing through the filtration membrane must be at least comparable to that of intraoperative blood processing by the centrifugation method (RBC recovery level greater than 80%, heparin amount less than 0.5 IU / ml). Summary of the Invention

[0017] There is now a need for an improved system for processing blood for autologous blood transfusion, which can in particular solve at least one of the above-mentioned drawbacks.

[0018] Another object of the present invention is to provide a blood treatment system for autotransfusion, which is easy to use and intuitive, and can be used by professionals with little or no training.

[0019] To this end, a system for treating hemorrhagic fluid previously obtained from a patient for autotransfusion is proposed, the system comprising a unit for treating the hemorrhagic fluid, the treatment unit comprising:

[0020] - a filtration device for tangential filtration, comprising a filtration membrane arranged in a housing so as to separate an inhalation chamber from a discharge chamber, the inhalation chamber and the discharge chamber each having an inlet and an outlet for the fluid;

[0021] - a treatment bag having an inlet and an outlet, the inlet and the outlet being fluidly connected to the outlet and the inlet of the inhalation chamber of the filtration device respectively through a recirculation line, such that the circulation of the hemorrhagic fluid in the recirculation line can pass through the inhalation chamber of the filtration device in a direction from the outlet of the treatment bag to the inlet of the treatment bag;

[0022] - an inhalation line fluidly connected to the recirculation line between the outlet of the treatment bag and the inlet of the inhalation chamber of the filtration device, so as to be able to supply the collected hemorrhagic fluid to the treatment unit for filtration through the filtration membrane of the filtration device, thereby removing the filtrate containing compounds not required for autotransfusion from the hemorrhagic fluid;

[0023] - a blood transfusion line fluidly connected to the recirculation line between the outlet of the treatment bag and the inlet of the inhalation chamber of the filtration device, so as to be able to recover the treated hemorrhagic fluid contained in the treatment bag;

[0024] - a discharge line fluidly connected to the outlet of the discharge chamber of the filtration device for discharging the filtrate passing through the filtration membrane from the inhalation chamber;

[0025] It is characterized in that the treatment unit further comprises

[0026] - a cleaning line fluidly connected to the inlet of the discharge chamber of the filtration device for delivering a cleaning fluid into the discharge chamber; and

[0027] - a first flow rate regulating member arranged for regulating the flow rate in the cleaning line; and a second flow rate regulating member arranged for regulating the flow rate in the discharge line so as to be able to control the pressure of the cleaning fluid in the discharge chamber.

[0028] The preferred but non-limiting aspects (alone or in combination) of the treatment system are as follows:

[0029] - The cleaning line is further fluidly connected to the recirculation line at a first position between the outlet of the treatment bag and the inlet of the suction chamber of the filtration device. The treatment unit further includes a dilution line configured to deliver a dilution fluid into the treatment unit. The dilution line is fluidly connected to the recirculation line at a second position between the outlet of the treatment bag and the inlet of the suction chamber of the filtration device. The dilution fluid can be used as the cleaning fluid.

[0030] - The treatment unit includes a third flow regulation member arranged for flow regulation in the dilution line, a fourth flow regulation member arranged for flow regulation in the recirculation line at the outlet of the treatment bag, and a fifth flow regulation member arranged for flow regulation in the recirculation line at the inlet of the suction chamber of the filtration device.

[0031] - During the treatment of the hemorrhagic fluid, the second position is upstream of the first position in the fluid circulation direction in the recirculation line.

[0032] - The system includes a single peristaltic pump arranged such that the hemorrhagic fluid circulates in the recirculation line in a direction from the outlet of the treatment bag through the suction chamber of the filtration device to the inlet of the treatment bag. The peristaltic pump is positioned in the recirculation line between the outlet of the treatment bag and the inlet of the suction chamber of the filtration device between the second position and the first position.

[0033] - The system includes at least one peristaltic pump arranged such that the hemorrhagic fluid circulates in the recirculation line in a direction from the outlet of the treatment bag through the suction chamber of the filtration device to the inlet of the treatment bag.

[0034] - The treatment bag includes a separator device that can be actuated to separate the treatment bag into a first treatment chamber on the inlet side of the treatment bag and a second treatment chamber on the outlet side of the treatment bag.

[0035] - The treatment bag has a generally parallelepiped shape, where the inlet and outlet are located along a diagonal on either side of the treatment bag. The treatment bag further has an inner cavity that has a tapered shape on the outlet side.

[0036] - The filter membrane of the filtration device is a filter membrane with hollow fibers, and the hollow fibers form a filter membrane that extends longitudinally into the housing.

[0037] - The hollow fiber filter membrane of the filtration device includes hollow fibers formed from a mixture of polysulfone and polyvinylpyrrolidone.

[0038] - The overall porosity of the filter membrane of the filtration device is between 0.1 μm and 1 μm, preferably around 0.6 μm.

[0039] - The total filtration surface area of the filter membrane of the filtration device is between 0.1 m 2 and 1 m 2 , preferably between 0.2 m 2 and 0.6 m 2 .

[0040] - The processing unit includes a sixth flow rate regulating member which is arranged for flow rate regulation in the blood transfusion pipeline.

[0041] - The processing system includes a plurality of regulating valves, each of which is respectively used to cooperate with one of the regulating members so as to regulate the corresponding flow rate.

[0042] - The processing unit includes a template capable of fixing the suction pipeline, the discharge pipeline, the recirculation pipeline, the blood transfusion pipeline and the cleaning pipeline.

[0043] - The processing system includes a support unit. The template of the processing unit has a foolproof shape, so that the processing unit can be preferably removably connected to the support unit according to a unique positioning.

[0044] - The support unit forms a horizontal support plane. The filtration device of the processing unit is designed to be connected to the support unit such that the hollow fibers of the filter membrane extend along a direction not included in the horizontal support plane.

[0045] - The processing system includes a blood transfusion unit, and the blood transfusion unit includes a blood transfusion bag which has an inlet for connecting to the blood transfusion pipeline so as to collect the processed hemorrhagic fluid from the processing bag before blood transfusion to a patient.

[0046] - The processing system includes a filtrate recovery unit. The recovery unit includes a recovery bag which has an inlet for fluid connection to the discharge pipeline. The recovery bag is further designed to be connected to a device for decompressing the recovery bag so as to circulate the filtrate from the discharge chamber of the filtration device through the discharge pipeline to the recovery bag.

[0047] - The processing system includes a filtrate recovery unit. The recovery unit includes a recovery bag which has an inlet for fluid connection to the discharge pipeline. The recovery bag is further arranged relative to the filtration device of the processing unit to decompress the recovery bag relative to the filtration device, so as to circulate the filtrate from the discharge chamber of the filtration device through the discharge pipeline to the recovery bag.

[0048] - The processing system includes a hemorrhagic fluid collection unit. The hemorrhagic fluid collection unit includes a receiving part which is used for collecting the hemorrhagic fluid previously collected from a patient. The collection receiving part has an outlet fluidly connected to the suction pipeline. The collection receiving part is preferably integrated with a pre-filtering device, so that the hemorrhagic fluid can be pre-filtered before being transmitted to the processing unit.

[0049] - The processing system further includes an additional pre-filtering device disposed in the suction line.

[0050] A method is also proposed for processing a hemorrhagic fluid previously obtained from a patient using the system for subsequent autologous transfusion, wherein, after partial or total treatment of the hemorrhagic fluid with the filtering device, the filter membrane is cleaned by generating a transmembrane countercurrent, which is generated by blocking the discharge line at the level of the second flow regulating member and by injecting a cleaning fluid from the cleaning line into the discharge chamber, and the pressure generated in the discharge chamber by injecting the cleaning fluid generates a countercurrent through the filter membrane, so that all or part of the components retained on the filter membrane can be stripped off.

[0051] Preferred but non-limiting aspects of the method for using the processing system (alone or in combination) are as follows:

[0052] - Countercurrent cleaning is performed periodically during the treatment of a determined volume of hemorrhagic fluid.

[0053] - Countercurrent cleaning is performed after complete treatment of a determined volume of hemorrhagic fluid.

[0054] - Countercurrent cleaning is performed by changing the circulation speed of the cleaning fluid, in particular by increasing and decreasing the circulation speed of the cleaning fluid.

[0055] - A determined volume of hemorrhagic fluid from the suction line is treated by circulating in the circulation line so as to pass through the filtering device multiple times to remove compounds not required for autologous transfusion, and the treatment bag enables a flow with a continuous flow rate to be maintained in the circulation line regardless of the volume of the hemorrhagic fluid to be treated.

[0056] - During the treatment of a determined volume of hemorrhagic fluid, the outlet of the treatment bag is blocked, and then a dilution fluid is injected into the circulation line, which is intended to pass through the filtering device in order to eliminate the hemorrhagic fluid present in the circulation line, and then the treated hemorrhagic fluid present in the treatment bag is isolated when the fluid present in the circulation line has a hematocrit level below a threshold.

[0057] According to another preferred but non-limiting aspect of the method for using the processing system, alone or in combination with the foregoing aspects, before and / or after countercurrent cleaning, the filter membrane is cleaned by rinsing, which is performed by blocking the outlet of the treatment bag, by blocking the discharge line at the outlet level of the discharge chamber of the filtering device, and by injecting a dilution fluid intended to pass through the filtering device into the suction chamber.

[0058] Furthermore, a system for processing hemorrhagic fluid previously obtained from a patient for autologous transfusion is proposed, the system comprising a unit for processing the hemorrhagic fluid, the processing unit comprising:

[0059] - A filtration device, which includes a filtration membrane for tangential filtration, the filtration membrane being arranged in a housing so as to separate an inhalation chamber from a discharge chamber, the inhalation chamber and the discharge chamber respectively having an inlet and an outlet for the fluid;

[0060] - A processing bag, which has an inlet and an outlet, the inlet and the outlet being fluidly connected respectively to the outlet and the inlet of the inhalation chamber of the filtration device through a recirculation pipeline, such that the circulation of the hemorrhagic fluid in the recirculation pipeline can pass through the inhalation chamber of the filtration device in a direction from the outlet of the processing bag to the inlet of the processing bag;

[0061] - An inhalation pipeline, which is fluidly connected to the recirculation pipeline between the outlet of the processing bag and the inlet of the inhalation chamber of the filtration device, so as to be able to supply the collected hemorrhagic fluid to the processing unit for filtration through the filtration membrane of the filtration device, thereby removing the filtrate including compounds not required for autologous transfusion from the hemorrhagic fluid;

[0062] - A transfusion pipeline, which is fluidly connected to the recirculation pipeline between the outlet of the processing bag and the inlet of the inhalation chamber of the filtration device, so as to be able to recover the processed hemorrhagic fluid contained in the processing bag;

[0063] - A discharge pipeline, which is fluidly connected to the outlet of the discharge chamber of the filtration device, so as to discharge the filtrate passing through the filtration membrane from the inhalation chamber;

[0064] It is characterized in that the processing unit further comprises

[0065] - A first flow rate regulating member, which is arranged for regulating the flow rate in the recirculation pipeline at the outlet of the processing bag, and

[0066] - A dilution pipeline, which is intended to convey a dilution fluid into the processing unit, the dilution pipeline being fluidly connected to the recirculation pipeline at a position between the outlet of the processing bag and the inlet of the inhalation chamber of the filtration device.

[0067] The preferred but non-limiting aspects (alone or in combination) of the processing system are as follows:

[0068] - The processing unit includes a hematocrit sensor, which is arranged to measure the hematocrit level of the hemorrhagic fluid circulating in the processing unit.

[0069] - The processing system further includes means for controlling the dilution line, which is programmed to control the delivery of dilution fluid into the processing unit based on the hematocrit level measured by the hematocrit sensor.

[0070] - An optical sensor is arranged at the level of the processing bag inlet to detect the nature of the fluid reaching the inlet level.

[0071] - The processing bag includes a separator device that can be actuated to separate the processing bag into a first processing chamber on the processing bag inlet side and a second processing chamber on the processing bag outlet side.

[0072] - The processing unit includes a second flow regulating member arranged for flow regulation in the dilution line and a third flow regulating member arranged for flow regulation in the recirculation line at the inlet of the suction chamber of the filtration device.

[0073] - The processing bag has a generally parallelepiped shape, with the inlet and outlet located along the diagonal on either side of the processing bag. The processing bag further has an inner cavity that has a tapered shape on the outlet side.

[0074] - The filter membrane of the filtration device is a filter membrane with hollow fibers, and the hollow fibers form a filter membrane that extends longitudinally into the housing.

[0075] - The hollow fiber filter membrane of the filtration device includes hollow fibers formed from a mixture of polysulfone and polyvinylpyrrolidone.

[0076] - The overall porosity of the filter membrane of the filtration device is between 0.1 μm and 1 μm, preferably around 0.6 μm.

[0077] - The overall filtration surface area of the filter membrane of the filtration device is between 0.1 m 2 and 1 m 2 preferably between 0.2 m 2 and 0.6 m 2 between.

[0078] - The processing system includes at least one peristaltic pump arranged such that the hemorrhagic fluid circulates in the recirculation line in the direction from the outlet of the processing bag through the suction chamber of the filtration device to the inlet of the processing bag.

[0079] - The processing system includes a plurality of regulating valves, each regulating valve being respectively used to cooperate with one of the regulating members to regulate the corresponding flow rate.

[0080] - The processing unit includes a template capable of fixing the suction line, discharge line, recirculation line, dilution line, and transfusion line.

[0081] - The processing system includes a support unit. The template of the processing unit has a foolproof shape, enabling it to connect the processing unit to the support unit according to a unique orientation.

[0082] - The support unit forms a horizontal support plane. The filtration device of the processing unit is designed to be connected to the support unit such that the hollow fibers of the filtration membrane extend along a direction not included in the horizontal support plane.

[0083] - The processing system includes a blood transfusion unit. The blood transfusion unit includes a blood transfusion bag that has an inlet for connection to a blood transfusion pipeline to collect the processed hemorrhagic fluid from the processing bag before blood transfusion to a patient.

[0084] - The processing system includes a filtrate recovery unit. The recovery unit includes a recovery bag that has an inlet for fluid connection to a discharge pipeline. The recovery bag is further designed to be connected to a device for decompressing the recovery bag so that the filtrate circulates from the discharge chamber of the filtration device through the discharge pipeline to the recovery bag.

[0085] - The processing system includes a filtrate recovery unit. The recovery unit includes a recovery bag that has an inlet for fluid connection to a discharge pipeline. The recovery bag is further arranged relative to the filtration device of the processing unit to decompress the recovery bag relative to the filtration device, so that the filtrate circulates from the discharge chamber of the filtration device through the discharge pipeline to the recovery bag.

[0086] - The processing system includes a unit for collecting hemorrhagic fluid. The unit includes a receiving part for collecting the hemorrhagic fluid previously obtained from a patient. The collection receiving part has an outlet that is fluidly connected to an inhalation pipeline. The collection receiving part is preferably integrated with a pre-filtering device so that it can pre-filter the hemorrhagic fluid before transmitting it to the processing unit.

[0087] - The processing system further includes an additional pre-filtering device placed in the inhalation pipeline.

[0088] There is also proposed a method for using the system to process the hemorrhagic fluid previously obtained from a patient for subsequent autologous blood transfusion. In this method, after partially or fully processing the hemorrhagic fluid with the filtration device, a dilution fluid is injected from a dilution pipeline into a circulation pipeline to pass through the filtration device.

[0089] According to a preferred aspect of this method of using the processing system, the filtration membrane is cleaned by flushing. This flushing is carried out by blocking the outlet of the processing bag at the level of a first flow regulating member, by blocking the discharge pipeline at the level of a second flow regulating member, and by injecting a cleaning fluid from the dilution pipeline into the inhalation chamber.

[0090] In this case, once the optical sensor detects the presence of the dilution fluid, the flushing can be stopped.

[0091] In a preferred manner, prior to flushing, the separator device can be controlled to isolate the hemorrhagic fluid being processed in the second processing chamber.

[0092] According to another preferred aspect of the method for using the processing system, in a complementary or alternative manner, the hemorrhagic fluid contained in the processing system is diluted by blocking the outlet of the processing bag at the level of the first flow regulating member, then injecting the cleaning fluid from the dilution line into the suction chamber, and then operating the dilution by isolating the processed hemorrhagic fluid present in the processing bag when the fluid present in the circulation line has a hematocrit level below the threshold.

[0093] Finally, a method is proposed for processing the hemorrhagic fluid contained in a container by filtration for subsequent autologous transfusion, the method comprising at least one step of concentrating by filtering the hemorrhagic fluid in order to increase the concentration of red blood cells in the hemorrhagic fluid, thereby reaching the target hematocrit level, while removing the filtrate comprising compounds not required for autologous transfusion from the hemorrhagic fluid, characterized in that the method further comprises the following steps:

[0094] - A preliminary step that measures the hematocrit level of the hemorrhagic fluid; and

[0095] - A dilution step that comprises adding a determined volume of dilution fluid to the volume of the hemorrhagic fluid to be processed, the determined volume of dilution fluid being calculated based on the measured hematocrit level of the hemorrhagic fluid and the target hematocrit level.

[0096] Preferably, the hemorrhagic fluid contained in the container is previously obtained from a patient. After being processed according to the method of processing by filtration, the processed hemorrhagic fluid can preferably be transfused to the patient from whom the fluid was obtained. It should be noted that the method of processing the hemorrhagic fluid by filtration is carried out without connection to the patient.

[0097] Preferred but non-limiting aspects of the method of processing by filtration, used alone or in combination, are as follows:

[0098] - The dilution step is carried out prior to the step of concentrating by filtration in order to increase the volume of the hemorrhagic fluid to be processed, thereby increasing the volume of the filtrate comprising compounds not required for autologous transfusion obtained during the step of concentrating by filtration to reach a given target hematocrit level.

[0099] - Further parameterize the process to obtain a concentration of a compound not required for autologous transfusion that is below the target concentration of the compound not required for autologous transfusion, and the target concentration of the compound not required for autologous transfusion is also used to calculate the determined volume of the dilution fluid for the dilution step.

[0100] - The initial concentration of the compound not required for autologous transfusion in the hemorrhagic fluid to be processed is also used to calculate the determined volume of the dilution fluid for the dilution step.

[0101] - Optimize the number of steps for concentration by filtration and dilution steps to minimize the overall processing time of the hemorrhagic fluid.

[0102] - Optimization is achieved by setting a maximum value for the volume of the dilution fluid for each dilution step and by increasing the number of steps for concentration by filtration.

[0103] - The processing method includes a number of steps for concentration by filtration that were previously followed by dilution steps respectively, wherein during the final dilution step, the determined volume of the dilution fluid is calculated based on the measured hematocrit level of the hemorrhagic fluid, the volume of the hemorrhagic fluid to be processed, the target hematocrit level, and the target concentration of the compound not required for autologous transfusion, while during the previous dilution steps, the determined volume of the dilution fluid is fixed.

[0104] - The processing method includes a number of steps for concentration by filtration that were previously followed by dilution steps respectively, wherein for each dilution step, the determined volume of the dilution fluid is calculated based on the measured hematocrit level of the hemorrhagic fluid, the volume of the hemorrhagic fluid to be processed, the target hematocrit level, and the target concentration of the compound not required for autologous transfusion.

[0105] - The processing method includes at least two steps for concentration by filtration that were previously followed by dilution steps respectively, and preferably exactly two steps for concentration by filtration that were previously followed by dilution steps respectively (i.e., a total of two dilution steps, each dilution step preceding the concentration step).

[0106] - Provide the dilution volume for the first dilution step before the first concentration step to eliminate at least 75% of the compound not required for autologous transfusion present in the hemorrhagic fluid before the first dilution and concentration steps.

[0107] - The processing method includes at least three steps for concentration by filtration that were previously followed by dilution steps respectively, and preferably exactly three steps for concentration by filtration that were previously followed by dilution steps respectively (i.e., a total of three dilution steps, each dilution step preceding the concentration step).

[0108] - Provide the dilution volume of the first dilution step before the first concentration step to eliminate at least 65% of the compounds not required for autologous transfusion present in the hemorrhagic fluid before the first dilution and concentration steps, and provide the dilution volume of the second dilution step before the second concentration step to also eliminate at least 65% of the compounds not required for autologous transfusion present in the hemorrhagic fluid before the second dilution and concentration steps.

[0109] - The treatment method includes a first step of concentration by filtration, which does not require pre-diluting the volume of the hemorrhagic fluid to be treated, followed by at least a dilution step and a step of concentration by filtration.

[0110] - The treatment method includes a first step of simple filtration, which does not require concentration and does not require pre-diluting the volume of the hemorrhagic fluid to be treated, followed by at least a dilution step and a step of concentration by filtration.

[0111] - According to the proposed treatment method:

[0112] - If the hematocrit level of the hemorrhagic fluid is greater than the threshold hematocrit level value, the first treatment step includes simple filtration, where no concentration is performed and no dilution of the volume of the hemorrhagic fluid to be treated is carried out first; and

[0113] - If the hematocrit level of the hemorrhagic fluid is less than or equal to the threshold hematocrit level value, the first treatment step includes concentration by filtration, where no dilution of the volume of the hemorrhagic fluid to be treated is carried out first.

[0114] - Determine the volume of the hemorrhagic fluid to be treated based on the measured hematocrit level and the target hematocrit level of the said hemorrhagic fluid. Description of the Drawings

[0115] Other features and advantages of the present invention will become more apparent from the following description, which is purely illustrative and non-limiting and should be read with reference to the accompanying drawings, in which:

[0116] Figure 1 is a schematic perspective view of a treatment system according to the present invention;

[0117] Figure 2 is a schematic diagram of a first arrangement of fluid connections for a treatment system according to the present invention;

[0118] Figure 3 is a schematic diagram of a treatment unit of a treatment system according to a first embodiment of the first arrangement;

[0119] Figure 4 is a schematic diagram of a treatment unit of a treatment system according to a second embodiment of the first arrangement;

[0120] Figure 5 is a schematic view of a processing bag of a processing unit of a processing system according to the present invention;

[0121] Figure 6 is a schematic view of a second arrangement of fluid connections for a processing system according to the present invention;

[0122] Figure 7 is a schematic view showing an exemplary positioning of an additional pre-filtering device for the described processing system. Detailed Description

[0123] Description of a system for processing hemorrhagic fluids for autologous transfusion

[0124] Figure 1 shows a non-limiting example of a system for processing a patient's hemorrhagic fluid, in particular blood, for autologous transfusion in particular.

[0125] The proposed processing system includes a certain number of functional units that are removable relative to each other to facilitate use by a practitioner, especially during a surgical intervention.

[0126] One of the particularities of the proposed processing system is the blood processing unit 100, which will be described in detail below.

[0127] The proposed processing system preferably includes a support unit 10, which can be in various forms, especially as Figure 1 shown, the main support body can be mounted on wheels. Preferably, the support unit 10 integrates the non-consumable elements of the processing system, that is, those elements that can be reused in a number of consecutive processing cycles, especially the system elements that do not come into direct contact with the patient's hemorrhagic fluid or any other substance that may cause contamination.

[0128] The support unit 10 can in particular integrate data processing means, for example in the form of one or more processors, but can also integrate control means so as to be able to control the processing of the hemorrhagic fluid according to predetermined processing parameters and / or according to control information input by the user of the system. In this regard, the support unit 10 can include control information input means, such as a keyboard, a tactile actuator, a voice recognition system or others. Preferably, information broadcasting means are also provided to inform the user of the processing cycle, and these information broadcasting means can be visual, auditory and / or tactile, including for example a screen, a lamp or a light emitting diode, a speaker, a vibrator or others.

[0129] The support unit 10 is also preferably integrated with elements for the energy supply of the processing system, in particular the power supply. The support unit 10 can integrate a battery to supply energy to the system, and in any case, it includes an electrical connector so that the support unit 10 can be connected to an electrical socket, such as a wall socket in a hospital.

[0130] The fluid circulation in the processing system is carried out by a fluid driving device, which is integrated in the support unit 10 or externally.

[0131] As the fluid driving device, for example, one or more peristaltic pumps 160 can be provided, so that the fluid existing in the processing system circulation loop can be moved in a specific direction of fluid movement, but can also be moved in the opposite direction. Preferably, the (multiple) peristaltic pumps are integrated in the support unit 10, where they can be directly powered. Preferably, the fluid driving device is arranged so that the hemorrhagic fluid can circulate in the processing unit 100 at a flow rate between 10 ml / min and 4000 ml / min, preferably between 100 ml / min and 2000 ml / min, and further preferably between 200 ml / min and 1400 ml / min.

[0132] In the fluid driving device, a vacuum system can also be provided, which is connected to the fluid circulation loop to generate a reduced pressure that is conducive to the movement of the fluid in the circulation loop in a specific movement direction. In this regard, one or more vacuum pumps can be integrated in the processing system, more specifically in the support unit 10, to generate the required reduced pressure. It can also be provided that the processing system includes a connector that can be connected to a wall vacuum socket at the place where the processing system is used, and a vacuum regulator so that the vacuum can be specifically controlled. Preferably, a device that can apply a vacuum of 0 to 100 kPa is provided.

[0133] The support unit 10 can further integrate other elements that can be reused in a number of consecutive processing cycles, and these elements are functionally associated with the operations performed by the processing unit 100, which will be described in detail below.

[0134] Therefore, the support unit can integrate a flow regulating valve, such as a solenoid valve that operates together with, for example, an electromagnet or a stepper motor, which is arranged to cooperate with the pipes of the processing unit 100 so as to be able to regulate the flow rate of the fluid circulating in the processing unit 100.

[0135] Sensors can also be provided so as to be able to monitor the progress of the processing during a specific processing cycle. For example, such sensors can include pressure sensors, weighing devices, and in particular sensors such as optical sensors for calculating the hematocrit level (for example, for calculating the hematocrit level of the fluid circulating in the processing unit).

[0136] As described above, these reusable elements are preferably integrated in the support unit 10, but it is also conceivable that one or more of them are integrated in the processing unit 100.

[0137] The processing system further includes a hemorrhagic fluid collection unit 200, which is adapted to be positioned on the support unit 10, as Figure 1 shown.

[0138] Such a collection unit 200 includes a receiving portion 210 for collecting hemorrhagic fluid obtained, for example, during a surgical intervention or beforehand from a patient.

[0139] As can be seen from Figure 2 shown, the collection receiving portion 210 has an outlet 210b, which is in fluid connection with the suction line 120 provided in the processing unit 100.

[0140] The collection receiving portion further includes an inlet 210a, which is intended to be connected to a blood collection device known per se, which generally includes a suction cannula for sucking hemorrhagic fluid and a device specifically for quantifying diluents and anticoagulants. Specific sources of these diluents and / or anticoagulants, such as a heparinized crystal composition, can be directly connected to the inlet 210a of the collection receiving portion 210.

[0141] More preferably, the collection receiving portion 210 is integrated with a pre-filtering device 220 so that the collected hemorrhagic fluid can be pre-filtered before being transferred to the processing unit 100. Such pre-filtering generally aims to filter out relatively large-sized particles to remove, for example, blood clots, bone fragments, and even tissue fragments present in the collected hemorrhagic fluid.

[0142] It is noted that pre-filtering is carried out to retain particles larger than a few tens of micrometers.

[0143] For example, a pre-filtering device 220 of the pre-filtering type with a porosity gradient can be used to retain particles of decreasing size, for example, with a porosity gradient gradually changing from 150 μm to 40 μm.

[0144] For example, the pre-filtering device 220 can be a multi-layer type filter, more specifically, a woven mesh layer that retains the largest components, a non-woven mesh layer whose thickness will retain smaller components by steric hindrance, and a final fine woven layer that retains the smallest components.

[0145] In a preferred manner, the collection unit 200 is further connected to a vacuum source, such as a wall vacuum socket 20a, via a vacuum regulator 250 to optimize the use of the pre-filtering of the pre-filtering device 220.

[0146] The weighing system 230 can be further provided in the collection unit 200, such as a force sensor forming a weight indicator, which is arranged to measure the amount of collected hemorrhagic fluid present in the collection receiving part 210. The weighing system 230 will enable information to be given for controlling the processing cycle, so that the processing cycle can be started, for example, when the collection receiving part 210 contains sufficient hemorrhagic fluid to start the processing cycle. The weighing system 230 can also control the amount of hemorrhagic fluid injected into the processing unit 100.

[0147] The processing system further includes a blood transfusion unit 400, which is intended to be arranged on the support unit 10 and connected to the blood transfusion pipeline 170 of the processing unit 100.

[0148] More specifically, the blood transfusion unit 400 includes a blood transfusion bag 410, which has an inlet 410a intended to be connected to the blood transfusion pipeline 170 in order to collect the processed hemorrhagic fluid from the processing bag 140 integrated in the processing unit 100 before blood transfusion to a patient. More specifically, when it is desired to perform a blood transfusion on a patient, it is recommended to disconnect the blood transfusion bag 410 from the processing system and connect it to the patient for the delivery of the processed hemorrhagic fluid.

[0149] The processing system also includes a recovery unit 300, which is also mounted on the support unit 10 and is intended to recover the filtrate from the processing unit 100, that is, the waste collected from the hemorrhagic fluid that is not suitable for being delivered to the patient.

[0150] Therefore, the recovery unit 300 includes a recovery bag 310 having an inlet 310a, which is intended to be in fluid connection with the discharge pipeline 130 of the processing unit 100.

[0151] Preferably, the recovery bag 310 is further arranged to be decompressed in such a way that it drives the fluid to circulate from the discharge pipeline 130 to the recovery bag 310.

[0152] For this purpose, the recovery bag 310 can be connected to a vacuum device, such as a vacuum system using a wall vacuum socket 20b and a vacuum regulator 330 and / or an autonomous system including at least a vacuum pump and an electronic regulator. Fine control of the applied vacuum can control the applied decompression to avoid it being too low and slowing down the processing speed or too high and damaging the red blood cells or the filter. Cut-off valves and exhaust valves 320 can also be provided as required for separating the vacuum system.

[0153] Alternatively or additionally, the decompression of the recovery bag 310 can be generated by a specific arrangement relative to the processing unit 100, especially by the height difference between the two units. For example, as from Figure 1As can be seen, the recovery unit 300 is preferably arranged at the lower part of the support unit 10, for example near the wheels, while the treatment unit 100 is arranged at the upper part, or at least at a level higher than the recovery unit 300. It should be noted that the decompression of the recovery bag 310 by a simple arrangement of the elements between them without using an artificial vacuum (such as using a vacuum pump) may help significantly limit the risk of hemolysis.

[0154] For example, a vertical distance separating the treatment unit 100 from the recovery unit 300 may be provided, and this vertical distance is at least 10 cm, preferably included between 20 cm and 100 cm, preferably included between 30 cm and 70 cm, and further preferably included between 30 cm and 60 cm.

[0155] Specifically, when the decompression of the recovery bag 310 is uniquely generated by a specific arrangement relative to the treatment unit 100, the vertical distance separating the treatment unit 100 and the recovery unit 300 is preferably selected to be greater than 30 cm, for example included between 50 cm and 70 cm, preferably included between 60 cm and 65 cm, and further preferably about 65 cm. A particularity of the proposed treatment system lies in the treatment unit 100, which is removable relative to the support unit 10 so as to be able to be easily and quickly replaced for each new patient, and has a configuration capable of quickly treating the collected hemorrhagic fluid without the drawbacks of the systems existing in the prior art, especially those based on centrifugation.

[0156] It should be noted that all the elements considered to be consumable of the treatment system that are intended to come into contact with the hemorrhagic fluid to be treated are removable relative to the support unit 10, and can therefore be replaced very easily. In addition to the treatment unit 100, this particularly concerns the collection unit 200, the recovery unit 300, and the transfusion unit 400.

[0157] The proposed treatment unit 100 is provided to be able to effectively treat the hemorrhagic fluid of a patient and be used several times continuously for the same patient so as to be able to perform several treatment cycles, thereby treating a larger amount of hemorrhagic fluid.

[0158] As described above, tangential filtration is preferably carried out, that is to say a filtration in which the hemorrhagic fluid to be filtered circulates parallel to the filtration membrane and is filtered when in contact with the filtration membrane.

[0159] For this purpose, the proposed processing unit 100 thus includes a filtering device 110 for tangential filtration, which has a filter membrane 113 that is arranged in a housing 114 so as to separate a suction chamber 111 from a discharge chamber 112, and the suction chamber 111 and the discharge chamber 112 each have an inlet (111a; 112a) and an outlet (111b; 112b) for a fluid. The hemorrhagic fluid to be processed circulates in the suction chamber 111 from the inlet 111a to the outlet 111b and undergoes tangential filtration through the filter membrane 113 in order to remove a filtrate from the hemorrhagic fluid, which filtrate includes compounds that are not required for autologous blood transfusion. The filtrate passes through the filter membrane 113 and enters the discharge chamber 112.

[0160] Preferably, the filtering device 110 for tangential filtration includes a filter membrane 113 that has hollow fibers arranged in a housing 114, and the hollow fibers form a filter membrane that extends longitudinally into the housing 114. The remainder of this description mainly refers to the processing unit with the filtering device 110 that has a filter membrane 113 with hollow fibers, but the corresponding teachings can be applied to all types of tangential filtration devices, especially for the clogging problem after continuous filtration.

[0161] In a preferred manner, the filter membrane 113 of the filtering device 110 with hollow fibers includes fibers formed of a material having properties that are conducive to its hydrophilicity. The fact that the filter membrane 113 has increased hydrophilicity can especially reduce the phenomenon of membrane clogging that occurs as filtration progresses. Reducing the fouling of the filter membrane 113 can maintain the improved efficiency of the filtering device 110.

[0162] Therefore, preferably, the hollow fibers of the filter membrane 113 are formed of a mixture of polysulfone (PES) and polyvinylpyrrolidone (PVP). For example, a PES membrane mixed with PVP before extrusion of the fibers is provided. The base material of the hollow fibers can also be selected from other biocompatible and commonly used materials, such as blood filtration membranes, such as in addition to PES, there are polymethyl methacrylate (PMMA), acrylonitrile-based copolymers or terpolymers.

[0163] In addition, the filter membrane 113 of the filtering device 110 with hollow fibers preferably has an overall porosity that is included between 0 μm and 1 μm. Pores of this size can allow proteins and other drug molecules that are not suitable for blood transfusion to pass through, while relevant compounds of the hemorrhagic fluid, namely red blood cells, white blood cells, and platelets, can be preserved.

[0164] In the proposed filtering device 110, the filter membrane 113 has an overall filtration surface area that is, for example, greater than 0.04 m 2 and, for example, is included between 0.1 m 2 and 3 m 2between, and preferably between 0.2 m 2 and 0.6 m 2 between. More specifically, the filtration surface area is selected to be sufficient to be able to rapidly filter the hemorrhagic fluid at the same time, usually within 5 minutes or less, but not so large as to avoid excessive protein adhesion and thus associated platelet loss. Preferably, a filtration device is selected that can perform filtration in less than 5 minutes to process a 500 ml volume of hemorrhagic fluid.

[0165] According to the first example, the filtration device may include a filtration membrane having hollow fibers longitudinally arranged in a cylindrical housing, the filtration membrane having an average pore size of 0.6 μm, a filtration surface area of 0.2 m 2 and the hollow fibers are formed of a mixture of polysulfone (PES) and polyvinylpyrrolidone (PVP), having an inner diameter of 300 μm, an outer diameter of 470 μm, and a wall thickness of 85 μm.

[0166] According to the second example, the filtration device has the same characteristics as according to the first example, but the filtration surface area is 0.6 m 2 .

[0167] According to the third example, the filtration device has the same characteristics as according to the first example, but the filtration surface area is 0.4 m 2 .

[0168] The processing unit 100 further includes a processing bag 140 that is fluidly connected to the filtration device 110 through a recirculation line 150.

[0169] More specifically, the processing bag 140 has an inlet 140a and an outlet 140b, and the inlet and outlet are fluidly connected to the outlet 111b and the inlet 111a of the suction chamber 111 of the filtration device 110 through the recirculation line 150, respectively.

[0170] This arrangement particularly enables the circulation of the hemorrhagic fluid in the recirculation line 150 in the direction from the outlet 140b of the processing bag 140 through the suction chamber 111 of the filtration device 110 to the inlet 140a of the processing bag 140.

[0171] The shape of the processing bag 140 is also set to be conducive to internal flow from the inlet 140a to the outlet 140b and to facilitate the mixing of the processed blood fluid, but at the expense of sedimentation effects and favorable circulation at the bottom of the bag. For example, as Figure 5As shown, the treatment bag 140 has a generally parallelepiped shape, with an inlet 140a and an outlet 140b located along a diagonal on either side of the treatment bag. More preferably, the treatment bag further has a lumen with a tapered shape on one side of the outlet 140b so as to converge the fluid contained in the treatment bag 140 towards the outlet 140b.

[0172] The treatment bag 140 has an active role during the treatment cycle of the hemorrhagic fluid. First, as will be seen from below, the treatment bag is capable of recirculating the hemorrhagic fluid during the treatment cycle, that is, several consecutive cycles in the filtration device 110, without changing the circulation flow rate of the hemorrhagic fluid during said treatment cycle. The treatment bag actually acts as a buffer zone, thus being able to absorb potential flow rate variations. The treatment bag 140 can also be used as a region where the hemorrhagic fluid to be treated is mixed with a dilution fluid so as to facilitate the filtration and elimination of soluble components, such as proteins and pharmaceutical substances, through the filtration device 110.

[0173] The treatment bag 140 can be equipped with a separator device 141, which can be actuated to divide the treatment bag 140 into a first treatment chamber 142 on the inlet 140a side of the treatment bag 140 and a second treatment chamber 143 on the outlet 140b side of the treatment bag 140, but this is not necessary. For example, such a separator device 141 can take the form of an electromechanical clamp, which can be actuated according to the sequence of the treatment cycle to form said first and second treatment chambers.

[0174] The fluid driving devices of the support unit 10 are arranged to mainly carry out the circulation of the hemorrhagic fluid in the above-mentioned direction from the outlet 140b of the treatment bag 140 through the suction chamber 111 of the filtration device 110 towards the inlet 140a of the treatment bag 140, and this direction is called the treatment direction. As will be seen from below, these fluid driving devices are also capable of selectively circulating certain specific stages of the treatment cycle in the opposite direction.

[0175] According to Figure 2 an exemplary embodiment, a peristaltic pump 160 is arranged in a recirculation line in the recirculation line 150 located between the outlet 140b of the treatment bag 140 and the inlet 111a of the suction chamber 111 of the filtration device 110. The peristaltic pump enables the hemorrhagic fluid to circulate in the above two circulation directions.

[0176] In addition, the treatment unit 100 includes various conduits, which enable the fluid to circulate within the treatment unit 100 itself using the aforementioned recirculation line 150 and also to reach / come from other units of the treatment system.

[0177] Accordingly, the processing unit 100 includes a suction line 120 that is fluidly connected to a recirculation line 150 between an outlet 140b of the processing bag 140 and an inlet 111a of a suction chamber 111 of the filtration device 110, so that the collected hemorrhagic fluid can be supplied to the processing unit 110 for filtration through a filtration membrane 113 having hollow fibers of the filtration device 110, thereby removing residues including compounds unnecessary for autologous blood transfusion from the hemorrhagic fluid. In addition, the suction line 120 is also intended to be removably connected to the above-mentioned collection unit 200.

[0178] As Figure 7 shown, it can be stipulated that on the side intended to be connected to the collection unit 200, an additional pre-filter device 122 is inserted into the suction line 120, so that additional filtration can be performed before the actual filtration by the filtration device 110 of the processing unit 100. The purpose of this additional pre-filter device 122 is to retain coagulated mass blocks called coagulants, which can form at the outlet of the collection receiving part 210 despite the optional pre-filter device 220.

[0179] The additional pre-filter device 122 operates like a dynamic filter, that is, it must be able to operate at the flow rate applied by the processing unit without degrading the processing time performance. The additional pre-filter device 122 preferably has a higher filtration level than the filtration level of the optional pre-filter device 220 of the collection receiving part 210.

[0180] For example, the additional pre-filter device 122 can have a filtration level between 40 μm and 200 μm, preferably between 100 μm and 170 μm, and further preferably about 150 μm. The retention volume of the coagulants can be between 5 ml and 100 ml, preferably between 20 ml and 50 ml.

[0181] Preferably, the additional pre-filter device 122 forms an integral part of the processing unit 100. However, it is also conceivable that the additional pre-filter device is integrated in the collection unit 200 at the outlet level of the collection receiving part 210.

[0182] Preferably, the additional pre-filter device 122 is removably mounted in the processing system, which enables, for example, the removal of the device and its cleaning in case of blockage.

[0183] The processing unit 100 further includes a blood transfusion line 170 which is also fluidly connected to a recirculation line 150 between an outlet 140b of the processing bag 140 and an inlet 111a of the suction chamber 111 of the filtration device 110, so that the processed hemorrhagic fluid contained in the processing bag 140 can be recovered. In addition, the blood transfusion line 170 is also intended to be removably connected to the above-mentioned blood transfusion unit 400.

[0184] In a preferred manner, as Figure 2 shown, the suction line 120 and the blood transfusion line 170 are tapped at the same position on the recirculation line 150, for example, by means of a multi-fluid connector 156. Therefore, a 3-way connector 156 as shown in Figure 2 , 3 and 4 can be used, wherein the inlet path is fluidly connected to the recirculation line 150 in the direction of the outlet 140b of the processing bag 140, the first outlet path is fluidly connected to the recirculation line 150 in the direction of the inlet 111a of the suction chamber 111 of the filtration device 110, the second outlet is fluidly connected to the suction line 120, and the third outlet is fluidly connected to the blood transfusion line 170.

[0185] As will be seen from the following, and as shown in, for example Figure 6 shown, however, it can be provided that the suction line is tapped at the level of the outlet 140b of the processing bag 140, upstream of the peristaltic pump 160. In this case, the blood transfusion line is connected to the recirculation line by means of a standard 2-way fluid connector. In this case, the peristaltic pump 160 does not have to be adapted to circulate the hemorrhagic fluid in two circulation directions, and it is sufficient to have a pump so that the hemorrhagic fluid can be circulated in a single direction, i.e., the processing direction.

[0186] In addition, the processing unit 100 includes a discharge line 130 which is fluidly connected to an outlet 112b of the discharge chamber 112 of the filtration device 110 in order to discharge the filtrate from the suction chamber 111, which has passed through the filtration membrane 113 with hollow fibers. In addition, the discharge line 130 is also used to be removably connected to the above-mentioned discharge unit 130.

[0187] When the collection bag 310 is set to be depressurized, for example, by a vacuum system, this can accelerate the filtration through the filtration membrane 113 of the filtration device 110, because the decompression enters the discharge chamber 112 through the discharge line 130.

[0188] In addition, the processing unit 100 may include a cleaning line 180 which is fluidly connected to an inlet 112a of the discharge chamber 112 of the filtration device 110 to deliver a cleaning fluid into the discharge chamber 112. It should be noted that in all the described exemplary embodiments, the cleaning line 180 is not necessary.

[0189] The purpose of the cleaning line 180 is to be able to convey a fluid into the discharge chamber 112 and to create a transmembrane countercurrent, that is, a flow in a direction opposite to the normal flow direction through the filtration membrane 113 with hollow fibers of the filtration device 110 during filtration. This countercurrent through the filtration membrane 113 is very useful for stripping all or part of the components retained on the hollow fibers of the filtration membrane 113 and is therefore very useful for regenerating the filtration capacity of the filtration membrane 113, especially in terms of filtration efficiency and speed. The proposed countercurrent is also advantageous because it enables the filtration membrane to be cleaned in a simple and rapid manner during or between treatment cycles.

[0190] A flow regulating member 181 arranged for flow regulation in the cleaning line 180 and another flow regulating member 131 arranged for flow regulation in the discharge line 130 can be provided so as to be able to control the pressure of the cleaning fluid in the discharge chamber 112.

[0191] Thus, by blocking the discharge line 130 at the level of the flow regulating member 131 and by injecting the cleaning fluid from the cleaning line 180 into the discharge chamber 112, a countercurrent can be generated, and the pressure generated in the discharge chamber 112 by injecting the cleaning fluid will create the desired transmembrane countercurrent.

[0192] When it is necessary to generate a countercurrent, the cleaning fluid can be directly injected into the cleaning line 180, and then an external source containing the cleaning fluid is provided.

[0193] Whether or not the treatment unit 100 includes a cleaning line 180, a dilution line 190 that can convey a dilution fluid into the treatment unit 100 can be further provided. Then, the dilution line 190 is preferably fluidly connected to the recirculation line 150 at a position between the outlet 140b of the treatment bag 140 and the inlet 111a of the suction chamber 111 of the filtration device 110. Preferably, the dilution line 190 is tapped upstream of the peristaltic pump 160.

[0194] In addition, the dilution line 190 is intended to be removably connected to a dilution unit 500 that includes a dilution receiving portion 510 having an inlet / outlet orifice 510a intended to be coupled to the dilution line. The dilution receiving portion 510 contains a dilution fluid intended to be injected into the treatment unit 100. The dilution fluid can be a crystalline composition, preferably an isotonic solution compatible with red blood cells, free of carbohydrates or proteins, including, for example, sodium chloride, sodium lactate, and / or potassium chloride diluted in water to form an injectable preparation.

[0195] A flow regulating member 191 is preferably provided to be able to perform flow regulation in the dilution line 190.

[0196] Apparatus for controlling the dilution line 190 may be provided, which is programmed, for example, to control the delivery of dilution fluid into the processing unit according to the hematocrit level measured by a hematocrit sensor, in particular according to the hematocrit level of the hemorrhagic fluid to be processed, as will be described in detail hereinafter.

[0197] For example, a control device may be provided to actuate the flow regulating member 191.

[0198] In a preferred manner, the cleaning line 180 is fluidly connected to the recirculation line 150 at a position between the outlet 140b of the processing bag 140 and the inlet 111a of the suction chamber 111 of the filtration device 110. When the processing unit 100 includes a dilution line 190, then the dilution fluid may be used to supply the cleaning line 180 and thus serve as a cleaning fluid.

[0199] Preferably, another flow regulating member 151 is provided in the processing unit 100 and is arranged for flow regulation in the recirculation line 150 at the level of the outlet 140b of the processing bag 140.

[0200] Preferably, yet another flow regulating member 152 is provided to enable flow regulation in the recirculation line 150 at the level of the inlet 111a of the suction chamber 111 of the filtration device 110.

[0201] A flow regulating member 171 arranged for flow regulation in the blood transfusion line 170 may also be provided, so that the flow transmitted to the blood transfusion unit 400 can be controlled.

[0202] Figures 2 to 4 and Figure 6 The exemplary embodiment shown in is a processing system in which the processing unit 100 requires a single peristaltic pump 160 to circulate fluid in a loop, and the peristaltic pump 160 is arranged such that the hemorrhagic fluid in the recirculation line 150 circulates in a specified processing direction from the outlet 140b of the processing bag 140 through the suction chamber 111 of the filtration device 110 to the inlet 140a of the processing bag 140.

[0203] Preferably, the peristaltic pump 160 can also circulate the flow in a direction opposite to the processing direction, that is, from the inlet 111a of the suction chamber 111 of the filtration device 110 to the outlet 140b of the processing bag 140. This is in Figure 2This is particularly advantageous in an exemplary embodiment, where the suction line 120 branches off downstream of the peristaltic pump 160, that is, at the level of the inlet 111a of the suction chamber 111 of the filtration device 110. Preferably, the peristaltic pump 160 is located in the recirculation line 150 between the outlet 140b of the treatment bag 140 and the inlet 111a of the suction chamber 111 of the filtration device 110, between the position where the dilution line 190 is fluidly connected to the recirculation line 150 and the position where the cleaning line 180 is fluidly connected to the recirculation line 150.

[0204] According to the intended operation of the treatment unit 100, as Figure 2 shown, the suction line 120 branches off the recirculation line 150 downstream of the peristaltic pump 160, that is, on one side of the inlet 112a of the suction chamber 112 of the filtration device, or as Figure 6 shown, it branches off the recirculation line 150 upstream of the peristaltic pump 160, that is, on one side of the outlet 140b of the treatment bag 140.

[0205] As Figure 2 shown, in the case where the suction line 120 branches off the recirculation line 150 downstream of the peristaltic pump 160, during the start of the treatment cycle, the hemorrhagic fluid will preferably be transferred from the collection receptacle 210 to the treatment bag 140.

[0206] In the case where the suction line 120 branches off the recirculation line 150 upstream of the peristaltic pump 160, during the start of the treatment cycle, the hemorrhagic fluid will preferably be transferred directly through the filtration device 110 from the collection receptacle 210. This has the advantage that the peristaltic pump 160 does not have to operate in both directions of the fluid circulation.

[0207] As described above, the treatment system preferably includes sensors so that the progress of the treatment can be monitored during a specific treatment cycle. In this regard, a pressure sensor 153 can be provided within the circulation line 150, particularly arranged to detect pressure fluctuations downstream of the peristaltic pump 160 along the treatment direction.

[0208] A hematocrit sensor 154 can be further provided to measure the hematocrit level of the fluid circulating in the treatment unit 100. Preferably, the hematocrit sensor is arranged such that it can also measure the hematocrit level of the fluid entering the system, that is, before any treatment.

[0209] By positioning it in a suitable manner, such as according to the arrangement shown in the figure, a single hematocrit sensor 154 can be used to measure the hematocrit level of the hemorrhagic fluid before, during, and after treatment.

[0210] Optionally, a number of hematocrit sensors are located at different points of the processing system. For example, specific positions of different hematocrit sensors can be provided so as to be able to measure the hematocrit level of the hemorrhagic fluid before, during and after processing.

[0211] For example, such a hematocrit sensor 154 can be an optical sensor formed by a component of an infrared emitting diode and a receiver.

[0212] A weighing system 155 can also be provided, such as a force sensor forming a weight indicator, which is arranged to measure the amount of fluid present in the processing bag 140. This weighing system 155 will be able to give information for controlling the processing cycle, so as to trigger, for example, the transfer of the processed hemorrhagic fluid to the transfusion unit 400 when a target parameter, especially the hematocrit level, is reached.

[0213] The processing unit 100 is a consumable, which is intended to be replaced for each new patient, and in particular, preferably, its processing is simple and easy. Since the processing unit 100 includes a certain number of different components and tubes forming fluid circulation pipelines, a template 101 can be provided (if necessary), which is especially capable of fixing the suction pipeline 120, the discharge pipeline 130, the recirculation pipeline 150, the transfusion pipeline 170, and the cleaning pipeline 180 and / or the dilution pipeline 190. The filtering device 110 and the processing bag 140 are components of the processing unit 100 and are thus pre-connected to the corresponding tubes and the template 101. Therefore, the processing unit 100 proposed in this way can be proposed as a consumable in the form of a kit for replacement as needed.

[0214] The template 101 is also arranged to be able to be easily placed in a proper position on the support unit 10 and has the shape of a foolproof device in this regard, so that the processing unit 100 can be connected to the support unit 10 according to a unique positioning.

[0215] In addition, the filtering device 110 of the processing unit 100 is intended to be connected to the support unit 10 such that the hollow fibers of the filter membrane 113 extend in a direction not included in the horizontal support plane defined by the support unit 10, that is to say, the filtering device 110 is inclined with respect to the water support plane. It should be noted that this horizontal support plane corresponds to the transverse plane of the support unit 10, which is parallel to the horizontal plane when the support unit 10 is placed on the ground.

[0216] Figure 3The example of shows a processing unit 100 with a template 101, which is arranged for the vertical placement of the template 101, that is to say, the template 101 is fixed in a plane different from the horizontal support plane of the support unit 10, for example, an inclined plane, and preferably a vertical plane (that is, perpendicular to the horizontal support plane). According to this embodiment, the filtering device 110 can also be fixed to the template 101, because placing the template 101 in place will necessarily result in an inclined arrangement of the filtering device 110.

[0217] Figure 4 The example of shows a processing unit 100 with a template 101, which is arranged for the horizontal placement of the template 101, that is to say, the template 101 is fixed in a plane parallel to the horizontal support plane of the support unit 10. According to this embodiment, the filtering device 110 is not fixed to the template 101 and will have to be fixed to the support unit 10 in an independent manner for an inclined arrangement relative to the horizontal support plane.

[0218] As Figure 3 and Figure 4 shown, the previously described flow regulating member can take the form of an orifice, which is arranged opposite to the pipe forming the fluid circulation pipeline whose flow must be controlled. Then a regulating valve is provided, for example, a solenoid valve operated by an electromagnet, which is arranged to abut the pipe through the orifice so as to control the cross-section of the pipe and thus control the flow of the fluid that can pass through it. In a preferred manner, these regulating valves are directly mounted on the support unit 10 and can thus be used for different successive processing units 100.

[0219] Placing the processing unit 100 including the template 101 in place is very simple. In fact, it is sufficient to position the template 101 in the housing provided for this purpose on the bracket. When the flow regulating member is an orifice designed to cooperate with the solenoid valve of the support unit 101, due to the anti-fooling device shape of the template 101, the relative placement is automatic. Once the template 101 is in place on the support unit 10, it is recommended to connect the suction pipeline 120 to the suction unit 200, the discharge pipeline 130 to the discharge unit 300, the blood transfusion pipeline 170 to the blood transfusion unit 400, and optionally the dilution pipeline 190 to the dilution unit 500. It should be noted that some units can be pre-connected to their corresponding pipelines, that is to say, they have been connected to the processing unit 100 before being placed in place on the support unit 10. For example, the blood transfusion unit 400 is preferably pre-connected to the blood transfusion pipeline 170, and the discharge unit 300 can also be pre-connected to the discharge pipeline 130. When the filtering device 110 and / or the processing bag 140 are not fixed to the template 101, it is recommended to fix them to the support unit 10.

[0220] Select a processing flow rate high enough to apply a large amount of shear force to limit the adhesion of proteins and platelets at the level of the filtration device, but not too much, otherwise undesirable hemolysis will occur. The selected flow rate is much larger than the flow rate typically recommended for filtration devices using a filtration membrane with hollow fibers, usually 5 to 10 times larger. In fact, it has been observed that in terms of cell concentration, the filtration results are very positive, and the high circulation flow rate is not an obstacle because the processing system is not directly connected to the patient, but is uniquely indirectly connected via the collection unit 200 on the one hand and via the transfusion unit 400 when the transfusion unit is connected to the patient on the other hand. In practice, as described above, the processing unit 100 preferably operates at a flow rate included between 10 ml / min and 4000 ml / min, and preferably between 100 ml / min and 2100 ml / min, for example 1400 ml / min or 700 ml / min.

[0221] A controlled vacuum between 0 and 100 kPa is applied at the level of the recovery unit 300 through the discharge line 130, so that the filtration speed can be increased and maintained constant. In addition, during the reverse process of transmembrane flow (especially during the countercurrent cleaning process), if the decompression is not continuously applied, de-priming of the filtration may be observed, thus making it impossible to continue the blood treatment.

[0222] In addition to the above advantages in terms of cleaning to extend the life and filtration efficiency of the filtration device 110, the passage of the dilution fluid used to rinse the filtration membrane 113 with hollow fibers between two treatment cycles also contributes to platelet recovery.

[0223] The proposed processing system for treating hemorrhagic fluids for autologous transfusion is simple to use and is capable of rapidly treating hemorrhagic fluids obtained from patients with quality performance superior to existing devices. In fact, all or part of the following performances can be achieved by the proposed processing device:

[0224] - The average yield of platelets is greater than or equal to 40%, or even greater than or equal to 50%, or even greater than or equal to 60%, even greater than or equal to 70%;

[0225] - The average yield of red blood cells (RBC) is greater than or equal to 80%, or even greater than or equal to 90%, even greater than or equal to 95%, or even around 99%;

[0226] - The average yield of white blood cells (WBC) is greater than or equal to 80%, or even greater than or equal to 90%, even greater than or equal to 95%, or even around 97%;

[0227] - Hemolysis is reduced, or even zero hemolysis or near-zero hemolysis. The target hemolysis will be able to be, for example, less than 1%, preferably less than 0.8%;

[0228] - The elimination of free hemoglobin is greater than or equal to 95%, or even greater than or equal to 98%;

[0229] - The residual concentration of heparin in the transfusion bag after treatment is less than or equal to 0.5 UI / ml;

[0230] - The processing time of 500 ml of hemorrhagic fluid to make it suitable for transfusion is less than or equal to 10 min, preferably less than or equal to 8 min, preferably less than or equal to 6 min, and the transfusion is carried out in an optimal way around 5 min or less than or equal to 5 min.

[0231] It should be noted that the levels of the above quality performances must be adjusted according to the operating conditions.

[0232] For example, if the processing has to be carried out very rapidly, then the performance may decline.

[0233] In the same way, if it is decided to concentrate the treated hemorrhagic fluid several times, for example, during three concentration processes, in order to ensure the elimination of compounds not required for autologous transfusion, such as heparin products not required for transfusion, some performances may decline. However, compared with the existing systems, the overall performance of the proposed processing system will not be reduced.

[0234] Operation of the system for treating hemorrhagic fluid for autologous transfusion

[0235] The exemplary operation of the proposed processing system is described below according to a standard mode and is in no way restrictive. In fact, the proposed processing system can be used in a standard mode according to different specific phases, adjusted according to the needs of surgical intervention or transfusion. The operation of the proposed processing system can also be adapted to specific operating situations, such as in an emergency situation where transfusion is required even if the processing is not completely finished, or when the volume of the hemorrhagic fluid to be treated is not optimal for the standard processing cycle.

[0236] Below, for example, with reference to Figures 2 to 4The first arrangement of the processing unit 100 shown presents an exemplary operation. According to this arrangement, the hemorrhagic fluid can be diluted before starting the concentration through the filtration device. The volume of the dilution fluid used can be fixed in advance or adjusted according to the initial concentration of the collected blood, that is, according to the hematocrit level of the hemorrhagic fluid to be processed. For a 500 ml bolus of hemorrhagic fluid, the volume of the flushing fluid used for dilution can be 200 ml, but the volume of this flushing fluid can be much higher, for example, around 18 liters (depending on the initial concentration of the anticoagulant in the hemorrhagic fluid). This dilution volume can be added at the start of the treatment, or during the treatment, in doses of from a few milliliters to several hundred milliliters, after the first concentration or without concentrating the volume of the hemorrhagic fluid.

[0237] In an exemplary operation according to, for example, Figure 6 In the exemplary operation of the second arrangement of the processing unit 100 shown, the hemorrhagic fluid entering the processing unit is concentrated as it passes through the filtration device before the flushing fluid is added. In fact, the hemorrhagic fluid passes directly through the filtration device 113 during its transfer from the collection unit 200 to the processing bag 140. The advantage of filtering before adding the dilution fluid is that soluble components are directly eliminated during the transfer to the processing bag. In this case, the fact that the filtration device can be unclogged is particularly advantageous because the filtration device will tend to foul more quickly.

[0238] A. Preparation stage of the processing system

[0239] First, the preparation phase of the proposed processing system will be described, including the installation phase of the components of the processing system, followed by the initialization and testing phase of the processing system.

[0240] All clamps for regulating the fluid flow formed by solenoid valves are in the open position.

[0241] The collection unit 200, the recovery unit 300, the blood transfusion unit 400, and the dilution unit 500 are installed on the support unit 10.

[0242] Next, the processing unit 100 is installed on the support unit 10. The clamps of the regulating valve 121 of the suction pipeline 120 and the clamps of the regulating valve 191 of the dilution pipeline 190 are closed.

[0243] The different units are finally connected by means of the pipes of the corresponding fluid circulation pipelines and the associated connectors, for example, these connectors are of the "Luer lock" type.

[0244] The collection unit 200 and the recovery unit 300 are connected to the wall vacuum sockets (20a; 20b). In addition, a source of heparinized crystal solution can be connected to the inlet 210a of the collection receiver 210.

[0245] Once all the components are connected to the support unit 10, the processing system can be started (powered on), and the initialization and testing phases of the processing system are started, controlled by the central unit of the support unit 10.

[0246] During this testing phase, it is verified that all the units are correctly connected to the support unit 10 and to each other. For example, optical contacts placed at the level of the support unit 10 can also be used, in particular so that the central unit obtains this type of information.

[0247] During the initialization process, the controller of the central unit controls the clamps of the different pipelines so that the regulating valves are all in the closed position.

[0248] Now, a vacuum source is supplied, and the processing system is operable to start a processing cycle.

[0249] B. Preparation stage of the pre-processing unit circuit before the first processing cycle

[0250] Before starting the actual processing cycle, a preparation phase of the processing cycle can be carried out in a preferred but optional manner, which can improve the efficiency of the actual processing cycle.

[0251] This preparation phase can be carried out before a surgical intervention, but is preferably carried out during a surgical intervention once bleeding is observed and autotransfusion is envisaged.

[0252] The perfusion of the collection unit 200 is first carried out by aspirating a heparinized crystal solution to fill the collection receptacle 210 until a certain volume is obtained in the collection receptacle 210. For example, such aspiration can be carried out by applying a vacuum of about 300 mbar in the collection receptacle 210. The collection receptacle 210 is filled with, for example, 200 ml of heparinized crystal solution. This perfusion of the collection unit with the heparinized crystal solution can moisten the collection unit 200, which will facilitate pre-filtration therein, especially in terms of filtration speed. In addition, this can heparinize the material, thus limiting the coagulation phenomenon.

[0253] Then, prime the recirculation line of the processing unit 100 that performs the actual processing. This priming can be started especially when the bleeding is active. To this end, activate the decompression of the recovery unit 300. For example, while activating the valve 320, apply a vacuum through the filtration device 110, while closing the regulating valve 121 of the suction line 120 and the regulating valve 191 of the dilution line 190, and open all other clamps. Next, close the clamp of the regulating valve 181 of the cleaning line 180, the clamp of the regulating valve 151 of the recirculation line 150, the clamp of the regulating valve 171 of the blood transfusion line 170, and open the clamp of the regulating valve 191 of the dilution line 190. Start the peristaltic pump 160, and the recirculation line 150 is filled with the dilution fluid from the dilution unit 500. The air present in the circuit is discharged via the discharge line 130, and the dilution fluid gradually fills the different empty chambers, especially the filtration device 110 and the processing bag 140, using the components of the processing unit 100.

[0254] After a time delay for filling the recirculation line, if necessary, prime the cleaning line 180. In this regard, while the decompression of the recovery unit 300 is still active, for example, apply a vacuum through the recovery unit 300, open the clamp of the regulating valve 181 of the cleaning line 180, and then close the clamp of the regulating valve 152 and the clamp of the regulating valve 151 of the recirculation line 150. Then, the dilution fluid circulates through the cleaning line 180 into the discharge chamber 112 of the filtration device 110, and then flows countercurrently through the hollow fibers of the filtration membrane 113.

[0255] This priming of the recirculation line and the cleaning line 180 of the processing unit 100 gradually fills the processing bag 140 with the dilution fluid.

[0256] Preferably, these priming phases continue until there is a certain volume of dilution fluid in the processing bag 140, which will be used to dilute / wash the hemorrhagic fluid to be processed. Preferably, close the clamp of the regulating valve 131 of the discharge line 130, and also close the vacuum valve 320 to fill the processing bag 140 with the dilution fluid more quickly. In the processing bag, continuing to fill with the dilution fluid to reach the specified washing volume is useful for the first processing cycle. For example, when it is desired to process a dose of about 500 ml of hemorrhagic fluid, a washing volume of 200 ml is used. As will be seen below, this washing volume will be able to vary, especially according to the hematocrit level of the hemorrhagic fluid to be processed. When the weight indicator 155 of the processing bag 144 detects that the washing weight (i.e., volume) has been reached, the pump 160 stops.

[0257] It is also conceivable that, after the perfusion phase, the processing bag 140 is not filled, but instead emptied via the discharge unit 300. In this case, when the hemorrhagic fluid is injected into the circuit of the processing unit 100, dilution of the dose of the hemorrhagic fluid will be carried out directly during the processing phase.

[0258] Accordingly, the processing unit 100 is ready to receive the first dose of the hemorrhagic fluid to be processed and perform the first processing cycle. While waiting for the collection receiver 210 to hold a sufficient amount of the hemorrhagic fluid (e.g., approximately 500 ml) for the first processing cycle, the clamps of the regulating valve 181 of the cleaning line 180 and the clamps of the regulating valve 191 of the dilution line 190 are closed so that all the clamps are closed.

[0259] When the amount of the hemorrhagic fluid to be processed is sufficient, the weight indicator 230 of the collection receiver 210 will trigger the start of the processing.

[0260] It should be noted that the opening / closing sequence of different clamps is selected so that the pump can operate continuously, thus having a continuous fluid circulation in the processing unit 100.

[0261] C. Processing stage of the hemorrhagic fluid

[0262] During the overall autologous blood transfusion process, there are three consecutive steps that are independent of each other:

[0263] E1. Collecting the hemorrhagic fluid, where patient intervention is required. In fact, the hemorrhagic fluid is collected from the patient and transferred to the collection receiver 210 of the collection unit 200.

[0264] E2. Processing the collected hemorrhagic fluid, which is done without any connection to the patient. This processing step is carried out by the proposed processing system, especially in the processing unit 100.

[0265] E3. Transfusing the processed hemorrhagic fluid, where patient intervention is required. The hemorrhagic fluid processed by the processing unit 100 and then transferred to the blood transfusion bag 410 of the blood transfusion unit 400 can be transfused into the patient. For this purpose, it is preferred to disconnect the blood transfusion bag 410 from the processing system to connect it to the patient.

[0266] The following description specifies step E2 of processing the hemorrhagic fluid previously collected from the patient during step E1. Regardless of whether there is a preparation phase for the circuit of the processing unit 100 as described above, when the volume of the hemorrhagic fluid in the collection receiver 210 reaches a threshold value, the first processing cycle will start, and this threshold value preferably corresponds to the volume of the dose that is desired to be processed in the processing cycle. For example, the dose of this hemorrhagic fluid is selected to be about 500 ml.

[0267] Therefore, in order to process a larger volume of hemorrhagic fluid than the fixed volume of the dose to be processed during the treatment cycle, it is recommended to perform several consecutive treatment cycles.

[0268] It should be noted that, in certain specific cases, the treatment cycle can be carried out when the volume of the hemorrhagic fluid is less than the fixed volume of the treatment dose, such as at the end of the treatment (when there is less hemorrhagic fluid remaining to be processed), at the end of bleeding, or at any appropriate time chosen by the practitioner. However, it should be noted that it is still necessary for the volume of the hemorrhagic fluid to be processed to be greater than, preferably at least twice the dead volume (VmTT) of the treatment circuit, that is, the volume included between the outlet 140b of the treatment bag 140 and the inlet 140a of the treatment bag 140, that is, the volume of the recirculation line 150 and the volume within the filtration device 113.

[0269] According to another embodiment, the volume of the hemorrhagic fluid to be processed is not fixed in advance but variable.

[0270] In this case, the volume of the dose of the hemorrhagic fluid to be processed is calculated in particular based on the number of red blood cells desired to be obtained in the volume of the hemorrhagic fluid to be retransfused.

[0271] For example, the volume of the dose of the hemorrhagic fluid to be processed can be calculated based on the hematocrit level of the hemorrhagic fluid to be processed and the target hematocrit level desired to be obtained in the volume of the hemorrhagic fluid to be retransfused.

[0272] In this case, the hematocrit level of the hemorrhagic fluid to be processed can be measured before treatment, for example, using the hematocrit sensor of the treatment system.

[0273] As already pointed out, once the weight indicator 230 of the collection receiving unit 210 has measured the target amount of the dose, the treatment cycle will be able to start automatically. For example, this dose can be equal to 500 ml of hemorrhagic fluid. During the pretreatment and perfusion phases of the treatment unit 100, this dose will be able to be mixed with the dilution fluid (for example, a volume of 200 ml) stored in the treatment bag 140. In the absence of a dilution volume in the treatment bag 140, for example, when the pretreatment phase is not started, or when the treatment starts with the filtration phase in the filtration device 113, it will be possible to directly introduce the required volume of dilution fluid from the dilution unit 500 into the recirculation line 150.

[0274] In order to mix the hemorrhagic fluid collected by the collection receiving unit 210 with the dilution fluid present in the treatment chamber 140, the treatment bag 140 should first be filled with the hemorrhagic fluid. To this end, the clamp of the regulating valve 121 of the suction line 120 and the clamp of the regulating valve 151 of the recirculation line 150 are opened, and the peristaltic pump 160 is started with reverse rotation, that is, the hemorrhagic fluid is driven in the direction opposite to the treatment direction to the outlet 140b of the treatment chamber 140. When the weight indicator 155 of the treatment bag 140 detects that the target treatment volume has been reached, the peristaltic pump 160 stops. It should be noted that this mixing step can be carried out by first injecting the hemorrhagic fluid into the treatment bag 140, or by first performing filtration and concentration, and then, if the dilution fluid does not exist yet, by injecting the dilution fluid into the same treatment bag 140.

[0275] Next, the actual stage of treating the hemorrhagic fluid may begin, using filtration and concentration until the target hematocrit level is obtained. Generally speaking, the pursued hematocrit level is about 45% + / - 5%, but it may also be about 50% + / - 5%, about 55% + / - 5%, or even up to 60% + / - 5%. For this stage, the clamp of the regulating valve 121 of the suction line 120 will thus be closed, and then the clamps of the regulating valve 152 of the recirculation line 150 and the regulating valve 131 of the discharge line 130 are opened; the electric control valve 320 is also actuated to apply a vacuum on the discharge chamber 112 through the recovery unit 300. Then, the peristaltic pump 160 is actuated along the treatment direction, so that the fluid contained in the treatment bag 140 circulates from the outlet 140b to the inlet 111a of the suction chamber 111 of the filtration device 110, and then circulates from the outlet 111b of the suction chamber 111 of the filtration device 110 to the inlet 140a of the treatment bag 140.

[0276] When passing through the filtration device 110, the hemorrhagic fluid to be treated is filtered by the filtration membrane 113 having hollow fibers, and compounds that are not required for autologous blood transfusion (such as proteins and other drug molecules not suitable for blood transfusion) are gradually removed. These compounds pass through the filtration membrane 113 until the discharge chamber 112, and then are sucked by the reduced pressure of the recovery unit 300 through the discharge line 130. The recirculation of the hemorrhagic fluid in the recirculation line 150 continuously passes through the filtration device 110 and the treatment bag 140 until the target hematocrit level is obtained, and this hematocrit level is detected, for example, at the level of the hematocrit sensor 154. The stop of the treatment can also be controlled by calculating the theoretical hematocrit level of the hemorrhagic fluid present in the treatment bag 140 based on the weight of the treatment bag (measured, for example, by the weighing system 155) and the hematocrit level of the input hemorrhagic fluid, that is, based on the hematocrit level of the hemorrhagic fluid before treatment and the volume of the hemorrhagic fluid to be treated.

[0277] This is referred to as concentration by filtration, that is, the hemorrhagic fluid is filtered until a specific red blood cell concentration corresponding to the target hematocrit level for transfusion is reached, while removing the filtrate from the hemorrhagic fluid, which includes compounds not required for transfusion, such as heparin. Thus, the concentration of the hemorrhagic fluid generally includes successive filtrations through the filtration device 110 and recirculation through the treatment bag 140.

[0278] Once the target hematocrit level is reached and once the volume of the concentrate (corresponding to the treated hemorrhagic fluid) in the treatment bag 140 is sufficient (e.g., greater than 100 ml), it is contemplated to transfer this concentrate to the transfusion bag 410 of the transfusion unit 400.

[0279] Preferably, but not mandatorily, the recirculation line 150 and the filter membrane 113 of the filtration device 110 are rinsed. More specifically, it is contemplated to rinse the dead volume (VmCF) of the filtration circuit, which corresponds to the circuit volume passing through the filtration device 110 between the transfusion unit 400 and the treatment bag 140. In this regard, the clamp of the regulating valve 151 of the recirculation line 150 and the clamp of the regulating valve 131 of the discharge line 130 are closed, and the clamp of the regulating valve 191 of the dilution line 190 is opened. The peristaltic pump 160 restarts its operation in the treatment direction to convey the dilution fluid from the dilution unit 500 towards the filtration device 110, and this dilution fluid is injected in order to push the blood column from the VmCF, and then the fluid can be stored in the treatment bag 140.

[0280] The rinsing of the suction line 120 can also be carried out simultaneously or not simultaneously with the rinsing of the recirculation line 150 and the filter membrane 113, in order to avoid any condensation inside the suction line 120. Preferably, the suction line 120 is rinsed between different treatment cycles, and for example, the dilution fluid of the dilution unit 500 or the fluid present in the treatment bag 140 can be used. An optical sensor can be provided at the level of the inlet 140a of the treatment bag 140, which can detect the nature of the fluid reaching the level of the inlet 140a. If such a sensor is used, then once the optical sensor detects the presence of the dilution fluid, the pump 160 can be stopped to stop the rinsing phase. This optical sensor enables the control of the stop of the pump 160 before the washing fluid enters the treatment bag.

[0281] For this rinsing phase, it is desirable that the processing bag 140 integrate a separator device 141 that can confine the concentrate in the processing chamber 142 at the lower part of the processing bag 140 on the outlet 140b side of the processing bag 140. Another processing chamber 141 formed by the separator device 141 in the upper part of the processing bag 140 on the inlet 140a side of the processing bag 140 can recover the fluid contained in the circuit and pushed by the dilution fluid during the rinsing phase.

[0282] It should be noted that several consecutive concentration phases can also be carried out on the same dose of the hemorrhagic fluid to be processed. This can especially better eliminate compounds not required for autotransfusion, such as heparin-type products not required for transfusion. Preferably, three concentrations are carried out on the same dose of the hemorrhagic fluid to be processed.

[0283] In an advantageous manner, when several consecutive concentrations are carried out, once the dose of the hemorrhagic fluid to be processed reaches the target hematocrit level after the concentration phase, the processed hemorrhagic fluid will be diluted again to remove impurities during a new concentration process.

[0284] When transfer is required after an optional rinsing or directly after the filtration and concentration phases, and / or after several concentration phases, it is recommended to close the clamp of the regulating valve 152 of the recirculation line 150 and the clamp of the regulating valve 191 of the dilution line 190 (if not already done), and open the clamp of the regulating valve 171 of the blood transfusion line 170 and the clamp of the regulating valve 151 of the recirculation line 150 (if not already done). Then, start the peristaltic pump 160 in the processing direction, and the concentrate is thus transferred from the processing bag 140 to the blood transfusion bag 410 of the blood transfusion unit 400.

[0285] It should be noted that the volume of the concentrate present in the processing chamber 140 can be preserved and thus not immediately transferred to the blood transfusion unit 400. Then, the concentrate will accumulate with the concentrate generated in subsequent processing cycles, that is, with another dose.

[0286] Once all or part of the concentrate is transferred to the blood transfusion unit 400, the processing cycle terminates, and another processing cycle can be triggered with another dose of the hemorrhagic fluid.

[0287] In particular, by disconnecting the blood transfusion bag 410 from the processing system and connecting it to the patient, step E3 of delivering the processed hemorrhagic fluid to the patient can be carried out. If immediate blood transfusion is not required, the blood transfusion bag 410 can also be stored, and a new blood transfusion bag 410 can be connected to the processing system to enable recovery of the newly processed hemorrhagic fluid.

[0288] As described above, the processing of the hemorrhagic fluid can be optimized by controlling the volume of the hemorrhagic fluid to be processed.

[0289] This is particularly advantageous for ensuring that the dose of hemorrhagic fluid to be processed can obtain the number of red blood cells required to reach the target hematocrit level after processing.

[0290] If the processing includes several successive concentration steps and a dilution step is provided before each concentration step, this control of the volume of the hemorrhagic fluid to be processed is also beneficial for adjusting and determining the optimal volume of the dilution fluid, such that the overall processing may be most effective, particularly while significantly limiting the hemolysis phenomenon and enabling the processing to be carried out as quickly as possible.

[0291] Therefore, the starting volume contained in the collection unit 200 and transferred to the processing unit 100 can be calculated by a program whose purpose is to obtain a certain amount of red blood cells in the processing bag, regardless of the initial concentration of red blood cells in the hemorrhagic fluid to be processed. This amount of red blood cells corresponds to the minimum fixed amount capable of delivering a certain volume of hemorrhagic fluid.

[0292] For example, when it is desired to obtain a 300 ml volume of concentrate with a hematocrit level of 45%, a certain volume of the hemorrhagic fluid to be processed needs to be used, which will enable at least 135 ml of red blood cells to be obtained after processing. Thus, the volume of the hemorrhagic fluid to be processed is calculated to obtain the minimum amount of red blood cells after filtration, here 135 ml.

[0293] Therefore, in addition to considering the target hematocrit level, the optimal volume of the hemorrhagic fluid to be processed can be determined based on the measured hematocrit level of the said hemorrhagic fluid to be processed.

[0294] According to the first embodiment, the volume of the hemorrhagic fluid to be processed can be directly controlled based on the measured value of the hematocrit level of this hemorrhagic fluid. Thus, the volume of the dose of the hemorrhagic fluid to be processed is fixed, which is greater than or equal to the theoretical volume required to obtain the required amount of red blood cells in the processed hemorrhagic fluid.

[0295] In order to compensate for potential errors in the measurement of the hematocrit level of the hemorrhagic fluid to be processed and / or to compensate for possible losses of red blood cells during the processing, a volume of the dose of the hemorrhagic fluid to be processed greater than the theoretical volume can be used, for example greater than 5%, 10%, 15% or 20%.

[0296] Preferably, the volume of the dose for the hemorrhagic fluid to be processed is not greater than 50% more than the theoretical volume.

[0297] According to the second embodiment, the volume of the dose of the hemorrhagic fluid to be processed is based on the volume V of the hemorrhagic fluid transferred to the processing bag 140 before starting the processing Tis calculated. It should be remembered that, depending on the arrangement of the processing unit, the hemorrhagic fluid can be transferred directly to the processing bag 140 without passing through the filtration device 110 ( Figures 2 to 4 as shown in the example), or it can be transferred to the processing bag 140 when passing through the filtration device 110 at least once ( Figure 6 as shown in the example).

[0298] Let us take as an example a processing system in which the hemorrhagic fluid to be processed enters the processing unit from the collection unit 200 at a certain collection flow rate D P The filtration flow rate D f through the filtration device of the processing unit is also known.

[0299] According to the first example of this second embodiment, the processing system can calculate the collection time in the collection unit 200.

[0300] In order to obtain Xe ml (= ET) of red blood cells in the processing bag from the hemorrhagic fluid with an input hematocrit level of Y E %, it is necessary to collect Zp (= V P ) ml of the hemorrhagic fluid to be processed from the collection unit 200: Zp = Xe / Ye.

[0301] Therefore, for the collection flow rate D P , the time to obtain this amount of red blood cells in the processing bag will be:

[0302] Tp = Zp / D P (F1)

[0303] According to the second example of this second embodiment, a processing system is provided to control the volume Za (= V T ) of blood entering the processing bag. The collection flow rate D P and the filtration flow rate Df are known parameters of the processing system (for example, D P is between 900 ml / min and 1200 ml / min, and Df is between 150 ml / min and 500 ml / min), and the input hematocrit level Y E of the hemorrhagic fluid to be processed is measured, and this hematocrit level is variable.

[0304] The processing system can be programmed to estimate the hematocrit level Ys at the outlet of the filtration module.

[0305] If the concentration of the hemorrhagic fluid obtained at the inlet of the filtration device 110 with a filtration flow rate of Df is Y E and the collection flow rate is D P , then the flow rate of the filtered hemorrhagic fluid with a concentration of Ys obtained at the outlet of the filtration device is D TTherefore, D T = D P - Df.

[0306] After filtration, there will be a transfer volume = V T , a collection volume V P and a filtrate volume V F , such that V T = V P - V F .

[0307] The input hematocrit level of the hemorrhagic fluid to be processed is given by Y E = Qe htie / V P , where Qe is the number of red blood cells present in the volume of hemorrhagic fluid to be processed.

[0308] The output hematocrit level of the filtered hemorrhagic fluid is given by Ys = Qs htie / V T , where Qs is the number of red blood cells present in the volume of filtered hemorrhagic fluid.

[0309] Therefore, we have: Ys = Qs htie / (V P – V f )

[0310] Considering Qs htie = Qe htie, we get: Ys = Qe htie / (V P – V f )

[0311] Therefore, since Qe htie = Y E * V P , it follows that: Ys = Y E * V P / (V P – V f )

[0312] That is, equivalently: Ys = Y E * D P / (D P – Df) (F2)

[0313] The processing system measures the volume in the processing bag, for example by means of a corresponding weighing system, and will thus fill the processing bag until the number of red blood cells in it reaches its target value: Qtéhtie in the processing bag = V T target * Ys.

[0314] And thus: V T target = Qs htie / Ys (F3)

[0315] Thus, a certain amount of hemorrhagic fluid to be processed is transferred from the collection unit 200 to the processing unit 100 to obtain a certain volume of hemorrhagic fluid V in the processing bag 140 T , which is the result of the procedure according to one or another example of the second embodiment, especially when the fluid to be processed passes through the filtration device 110 before reconnecting the processing bag 140.

[0316] Thus, the measured value of the hematocrit level of the hemorrhagic fluid to be processed can control the processing in a more refined manner, especially optimizing the sequence of concentration by filtration.

[0317] It is specifically determined that the higher the hematocrit level of the hemorrhagic fluid to be processed, the greater the volume to be washed. In addition, the washing volume is preferably adjusted to achieve a specific goal of eliminating compounds unnecessary for transfusion, such as heparin.

[0318] Therefore, if the hemorrhagic fluid to be processed has a high concentration of red blood cells, it will quickly reach the target hematocrit level at the outlet of the filtration device, and the volume of blood to be washed will be greater.

[0319] The processing of the hemorrhagic fluid may include several consecutive steps to obtain the desired characteristics of the hemorrhagic fluid to be retransfused according to the required performance, which have been described in the above description.

[0320] Thus, the method for processing the hemorrhagic fluid includes at least one stage of concentrating the hemorrhagic fluid to obtain the required target hematocrit level. As described above, this concentration step may include several consecutive steps of filtration and recirculation through the processing bag and the recirculation pipeline. This is called concentration by filtration.

[0321] Preferably, the processing method includes at least one dilution step, which includes adding a determined volume of diluent to the volume of the hemorrhagic fluid to be processed. As described above, the determined volume of the diluent is preferably calculated based on the measured hematocrit level and the target hematocrit level of the hemorrhagic fluid to be processed.

[0322] More preferably, the dilution step is carried out before the step of concentration by filtration, so as to increase the volume of the hemorrhagic fluid to be processed, thereby increasing the volume of the filtrate including compounds unnecessary for autologous transfusion obtained during the step of concentration by filtration to reach a given target hematocrit level.

[0323] Once the hemorrhagic fluid to be processed is circulated in the processing unit 100, the first step of the processing will vary according to the measured hematocrit level and the target hematocrit level of the hemorrhagic fluid to be processed.

[0324] It may be advantageous to set a critical value for the initial hematocrit level of the hemorrhagic fluid to be treated such that the hematocrit level at the outlet of the filtration device is not greater than the critical value, as being greater than the critical value would increase hemolysis and clogging of the filtration device in the case of recirculation.

[0325] Thus, the first step of the treatment may include a step of concentration by filtration, where the volume of the hemorrhagic fluid to be treated is not diluted first. This can be particularly the case when the measured hematocrit level of the hemorrhagic fluid to be treated is less than a certain value, for example less than 35%.

[0326] The first step may alternatively include a simple filtration step, where no concentration is carried out and the volume of the hemorrhagic fluid to be treated is not diluted first. This can be particularly the case when the measured hematocrit level of the hemorrhagic fluid to be treated is greater than or equal to a certain value, for example greater than or equal to 35%.

[0327] When the treatment system allows, it is also conceivable to start with a dilution step before the step of concentration by filtration. This will also be preferred when the hemorrhagic fluid to be treated has a relatively high measured hematocrit level, for example greater than 35%.

[0328] When the measured hematocrit level of the hemorrhagic fluid to be treated is relatively high (generally greater than or equal to 35%), it is actually preferred not to directly carry out a cycle of concentration by filtration to avoid hemolysis, cell degradation and clogging of the filtration device in the case of recirculation.

[0329] It is preferred to have several steps of concentration by filtration, where each step of concentration by filtration is preceded by a dilution step.

[0330] The number of steps of concentration by filtration and dilution steps is optimized to minimize the overall treatment time of the hemorrhagic fluid on the one hand to reach the target hematocrit level, and also to obtain the required treatment performance, particularly regarding the final concentration of compounds not required for autotransfusion (such as heparin).

[0331] In a surprising manner, it has been found that in order to reach the target hematocrit level, it is possible to be more efficient and faster to treat a certain volume of hemorrhagic fluid with a given hematocrit level by carrying out several dilution steps followed by concentration by filtration respectively, rather than carrying out a single step of concentration by filtration after the dilution step.

[0332] In fact, the fractionation of the overall treatment can be carried out in shorter intermediate steps and ultimately reduce the overall treatment time for the same treatment performance. In fact, fractionation will reduce the total dilution volume used for the entire treatment process. Therefore, due to fractionation, the washing efficiency is higher.

[0333] The following table illustrates the number of dilution steps and their characteristics for washing the hemorrhagic fluid to be processed according to the amount of red blood cells, where the hemorrhagic fluid to be processed has an initial hematocrit level of 15%, and the treatment end target is 50%, and has an initial heparin concentration of 12 UI / ml, and the treatment end target is less than 0.5 UI / ml.

[0334] [Table 1]

[0335]

[0336]

[0337] From these data, it can be observed that it is preferable to fractionate the overall washing to reduce the overall total dilution volume, thereby reducing the treatment time. In fact, for example, it has been observed that for washing a volume of hemorrhagic fluid containing 150 ml of red blood cells, two dilutions before concentration are more effective than a single dilution before concentration; the overall dilution volume is reduced by nearly three times, which will reduce the treatment time by the same amount.

[0338] Under the above conditions, it can be clearly seen that it is preferable to use two or three dilution steps rather than a single dilution step. If the difference in the overall dilution volume between several washing options is not significant, the washing option involving the least amount of washing can be selected, as this can reduce the number of different steps in the overall treatment of the hemorrhagic fluid, thereby reducing the non-compressible time between each of these different steps. In addition, it should be noted that the diversity of washing poses an additional risk to cell quality, especially the risk of hemolysis.

[0339] Therefore, the number of dilution steps followed by a concentration step respectively depends on the total dilution volume received by the treatment system and according to the duration of the treatment and the hemolysis factors generated by these successive dilutions and concentrations.

[0340] In all cases, the dilution volume is a function, on the one hand, of the difference in the substances to be eliminated (and thus the initial concentration and the concentration to be obtained), and on the other hand, of the volume of the concentrate to be delivered and the hematocrit level (and thus the amount of red blood cells included in the concentrate at a given hematocrit level).

[0341] The higher the volume of the concentrate, the hematocrit level, and the substance concentration, the greater the washing volume, and thus the more important it is to select a multiple sequence, and vice versa.

[0342] In a preferred manner, the proposed treatment method includes two or three dilution steps before the concentration step respectively.

[0343] In practice, for a small amount of red blood cells (e.g., less than 150 ml of red blood cells), a sequence with 2 washes is preferred, while for a large amount of red blood cells (e.g., greater than or equal to 150 ml of red blood cells), a sequence with 3 washes is preferred.

[0344] It should be noted that a single dilution step can preferably be carried out before the concentration step, especially when the starting concentration of the compound not suitable for transfusion is low, e.g., when the starting concentration of heparin is less than 5 IU / ml, especially less than 3 IU / ml.

[0345] As described above, it is preferred to calculate the determined volume of the dilution fluid for the dilution step based on the measured hematocrit level and the target hematocrit level of the hemorrhagic fluid to be treated.

[0346] When treating the concentration of a compound not required for autologous transfusion which is also parameterized to obtain a target concentration lower than that of the compound not required for autologous transfusion, the target concentration of the compound not required for autologous transfusion can also be used to calculate the determined volume of the dilution fluid for the dilution step.

[0347] The initial concentration of the compound not required for autologous transfusion of the hemorrhagic fluid to be treated can also be used to calculate the determined volume of the dilution fluid for the dilution step. In this case, it should be possible to monitor the amount of heparin introduced into the hemorrhagic fluid to be treated to deduce the concentration therefrom. This can be done by monitoring, for example, the flow rate of the device into which heparin can be injected. The concentration can also be estimated based on existing clinical data, and for safety reasons, the maximum value of the risks present in the blood and to be eliminated can be taken.

[0348] When the treatment includes several dilution steps respectively followed by a step of concentration by filtration, then during the last dilution step, the determined volume of the dilution fluid is calculated based on the measured hematocrit level of the hemorrhagic fluid, the volume of the hemorrhagic fluid to be treated, the target hematocrit level and the target concentration of the compound not required for autologous transfusion.

[0349] In this case, in the previous dilution steps, the determined volume of the dilution fluid can be fixed. In this case, the dilution volume can be fixed according to the characteristics of the treatment unit. In particular, the minimum volume of the dilution fluid is selected to avoid the phenomena of hemolysis of the hemorrhagic fluid and clogging of the filtration device. For example, the dilution volume can be fixed between 250 ml and 350 ml.

[0350] According to another possible embodiment, for each successive dilution step, the determined volume of the dilution fluid is calculated based on the measured hematocrit level of the hemorrhagic fluid, the volume of the hemorrhagic fluid to be treated, the target hematocrit level and the target concentration of the compound not required for autologous transfusion.

[0351] The higher the target hematocrit value of the concentrate, the more of the unwanted compounds in massive transfusions are eliminated at each concentration. However, there is a limit which preferably should not be exceeded so as not to damage the cells, especially red blood cells, and cause hemolysis by rupturing the red blood cells.

[0352] Thus, for a treatment sequence with two dilution steps each followed by a concentration step by filtration, for example, the dilution volume of the first dilution step can be calculated so as to eliminate at least 75% (e.g., 80%) of the unwanted substances (e.g., heparin) contained in the concentrate. The dilution volume of the second dilution may be subject to the target concentration of the unwanted substance.

[0353] For a treatment sequence with three dilution steps each followed by a concentration step by filtration, for example, the dilution volumes of the first dilution step and the second dilution step can be calculated so as to eliminate at least 65% (e.g., 66%) of the unwanted substances (e.g., heparin) contained in the previous concentrate. The dilution volume of the third dilution may be subject to the target concentration of the unwanted substance.

[0354] The above parameters are particularly advantageous for a target hematocrit level of 50%.

[0355] D. Cleaning stage of the filtration device

[0356] During filtration on the membrane, during successive treatment cycles, a decrease in the filtration flow rate is generally observed throughout the process. This decrease in the filtration capacity of the filtration membrane is caused by several phenomena, especially by adsorption and the blocking and clogging of the pores by the compounds to be filtered. Fouling caused by adsorption can lead to a permeability loss of up to 90%, and even to a complete blockage of the filtration.

[0357] The proposed treatment system, particularly the specific treatment unit 100 proposed in this document, can clean the filtration device 110 during the treatment of the hemorrhagic fluid for the same patient without having to remove the filtration device 110 from the treatment unit 100, and thus the overall treatment of the hemorrhagic fluid does not experience or experiences very little interruption.

[0358] It is conceivable to carry out several types of cleaning of the filtration device 110 by the proposed treatment system, and these types of cleaning can be carried out separately or complement each other.

[0359] The first type of cleaning consists of flushing the suction chamber 111 of the filtration device 110, which is carried out by introducing a dilution fluid in the direction of the inlet 111a of the suction chamber 111 of the filtration device 110 from the dilution unit 500. This type of flushing has been described above during the last stage of the treatment cycle before the effective transfer of the concentrate.

[0360] The second type of cleaning involves flushing the suction chamber 112 of the filtration device 110, which is carried out by introducing a dilution fluid from the dilution unit 500 in the direction of the inlet 112a of the discharge chamber 112 of the filtration device 110. This flushing can empty the filtrate that may still be present in the discharge chamber 112 and discharge it into the recovery bag 310 via the discharge line 130. For this purpose, the clamp of the regulating valve 171 of the blood transfusion line 170 and the clamp of the regulating valve 151 of the recirculation line 150 can be closed, and the clamp of the regulating valve 191 of the dilution line 190 and the clamp of the regulating valve 181 of the cleaning line 180 can be opened. It is also preferable to close the clamp of the regulating valve 152 of the recirculation line 150. Then, the peristaltic pump is started to circulate the dilution fluid along the treatment direction of the dilution bag 500 to the filtration device 110.

[0361] The third type of cleaning involves unclogging the filter membrane 113 of the filtration device 110 by generating a transmembrane countercurrent as described above. For this purpose, the electric control valve 320 for stopping the vacuum in the recovery unit 300 and the clamp of the regulating valve 131 of the discharge line 130 are closed. The clamp of the regulating valve 171 of the blood transfusion line 170, the clamp of the regulating valve 151 of the recirculation line 150, and the clamp of the regulating valve 152 of the recirculation line 150 are also closed, and the clamp of the regulating valve 191 of the dilution line 190 and the clamp of the regulating valve 181 of the cleaning line 180 are opened. In fact, the discharge line 130 is blocked, and the pressure of the cleaning fluid in the discharge chamber 112 increases, thus stripping the compounds fixed on the filter membrane 113. The pressure in this discharge chamber 112 can be controlled by changing the driving speed of the pump 160 or by changing the flow rate at the level of the regulating valve 181 of the cleaning line 180. Once the compounds are stripped from the filter membrane 113, as described previously, the discharge chamber 112 can be flushed by opening the clamp of the regulating valve 131 of the discharge line 130. It should be noted that the unclogging flow rate, that is, the circulation flow rate of the cleaning fluid for generating the transmembrane countercurrent, is preferably at least equal to the treatment flow rate, that is, the circulation flow rate of the hemorrhagic fluid in the treatment unit 100. In fact, it has been observed that this will result in a faster overall treatment time while reducing the loss of red blood cells per cycle. For example, when the unclogging flow rate changes from 1200 ml / min to 600 ml / min, the loss of red blood cells is only 5% compared to 10%. The performance of the cleaning fibers is also improved.

[0362] The above three types of cleaning can be carried out separately or in combination one after another.

[0363] For example, the following cleaning sequence in two stages can be envisaged:

[0364] -a1. According to the cleaning of the above-mentioned third type, the filter membrane 113 of the filtration device 110 is dredged, especially cleaning the filter membrane from the outside to the inside; then

[0365] -b1. According to the cleaning of the above-mentioned first type, the suction chamber 111 of the filtration device 110 is rinsed.

[0366] According to another example, the following cleaning sequence of three stages can be envisaged:

[0367] -a1. According to the cleaning of the above-mentioned first type, the suction chamber 111 of the filtration device 110 is rinsed; then

[0368] -b2. According to the cleaning of the above-mentioned third type, the filter membrane 113 of the filtration device 110 is dredged, especially cleaning the filter membrane from the outside to the inside; then

[0369] -c2. According to the cleaning of the above-mentioned first type, the suction chamber 111 of the filtration device 110 is rinsed.

[0370] Once the filtration device 110 has been cleaned, the dilution volume present in the treatment chamber 140 can be adjusted, and this dilution volume can be used for subsequent treatment cycles, as explained above with reference to the preparation stage of the treatment cycle. Therefore, after the cleaning stage, it is recommended to close the clamp of the regulating valve 181 of the cleaning pipeline 180, while maintaining the clamp of the regulating valve 131 of the discharge pipeline 130 closed, and open the clamp of the regulating valve 152 of the recirculation pipeline 150, while continuing to circulate the dilution fluid through the pump 160.

Claims

1. A method for processing a hemorrhagic fluid contained in a container by filtration for subsequent autologous transfusion, the method comprising at least one step of concentrating by filtering the hemorrhagic fluid so as to increase the concentration of red blood cells in the hemorrhagic fluid, thereby achieving a target hematocrit level while removing a filtrate comprising compounds not required for autologous transfusion from the hemorrhagic fluid, characterized in that, The method further comprises the following steps: - A preliminary step that measures the hematocrit level of the hemorrhagic fluid; and - A dilution step that comprises adding a determined volume of dilution fluid to the volume of the hemorrhagic fluid to be treated, the determined volume of dilution fluid being calculated based on the measured hematocrit level and a target hematocrit level of the hemorrhagic fluid, wherein the method comprises at least two steps of concentration by filtration that are preceded separately by dilution steps, and a dilution volume of a first dilution step is provided before a first concentration step to eliminate at least 75% of the compounds not required for autologous transfusion present in the hemorrhagic fluid before the first dilution and concentration steps.

2. The method according to claim 1, wherein, The dilution step is carried out before the step of concentration by filtration so as to increase the volume of the hemorrhagic fluid to be treated, thereby increasing the volume of the filtrate comprising the compounds not required for autologous transfusion obtained during the step of concentration by filtration to reach a given target hematocrit level.

3. The method according to claim 2, wherein, The treatment is further parameterized to obtain a concentration of the compounds not required for autologous transfusion that is lower than a target concentration of the compounds not required for autologous transfusion, and the target concentration of the compounds not required for autologous transfusion is also used to calculate the determined volume of dilution fluid for the dilution step.

4. The method according to claim 3, wherein, The initial concentration of the compounds not required for autologous transfusion of the hemorrhagic fluid to be treated is also used to calculate the determined volume of dilution fluid for the dilution step.

5. The method according to claim 3, wherein, The number of steps of concentration by filtration and dilution steps is optimized to minimize the overall treatment time of the hemorrhagic fluid, the optimization being achieved by fixing a maximum value of the volume of dilution fluid for each dilution step and by increasing the number of steps of concentration by filtration.

6. The method according to claim 2, comprising a number of concentration steps by filtration that were previously diluted separately, wherein, During a final dilution step, the determined volume of dilution fluid is calculated based on the measured hematocrit level of the hemorrhagic fluid, the volume of the hemorrhagic fluid to be treated, the target hematocrit level, and the target concentration of the compounds not required for autologous transfusion, while during a previous dilution step, the determined volume of dilution fluid is fixed.

7. The method according to claim 2, comprising a number of steps of concentration by filtration that are preceded separately by dilution steps, wherein for each dilution step, the determined volume of dilution fluid is calculated based on the measured hematocrit level of the hemorrhagic fluid, the volume of the hemorrhagic fluid to be treated, the target hematocrit level, and the target concentration of the compounds not required for autologous transfusion.

8. The method according to claim 1, comprising at least three steps of concentration by filtration that are preceded separately by dilution steps.

9. The method according to any one of claims 1 to 7, comprising a first step of concentration by filtration that is not preceded by dilution of the volume of the hemorrhagic fluid to be treated and is followed at least by a dilution step and a step of concentration by filtration.

10. The method according to any one of claims 1 to 7, comprising a first simple filtration step that does not perform concentration and does not first dilute the volume of the hemorrhagic fluid to be treated, the first simple filtration step being at least followed by a dilution step and a step of concentration by filtration.

11. The method according to any one of claims 1 to 7, further comprising a first treatment step, for which: - if the hematocrit level of the hemorrhagic fluid is greater than a threshold hematocrit level value, the first treatment step comprises simple filtration, where concentration is not performed and the volume of the hemorrhagic fluid to be treated is not first diluted; and - if the hematocrit level of the hemorrhagic fluid is less than or equal to the threshold hematocrit level value, the first treatment step comprises concentration by filtration, where the volume of the hemorrhagic fluid to be treated is not first diluted.

12. The method according to claim 1, wherein, Determine the volume of the hemorrhagic fluid to be treated based on the measured hematocrit level and the target hematocrit level of the hemorrhagic fluid.

13. A system for treating a hemorrhagic fluid for autologous transfusion, the system comprising a unit (100) for treating the hemorrhagic fluid, the treatment unit (100) comprising: - a filtration device (110), the filtration device comprising a filtration membrane (113) for tangential filtration, the filtration membrane being arranged in a housing (114) so as to separate a suction chamber (111) from a discharge chamber (112), the suction chamber (111) and the discharge chamber (112) each having an inlet (111a; 112a) and an outlet (111b; 112b) for the fluid; - a treatment bag (140), the treatment bag having an inlet (140a) and an outlet (140b), the inlet and the outlet being fluidly connected to the outlet (111b) and the inlet (111a) of the suction chamber (111) of the filtration device (110) respectively via a recirculation line (150), such that the circulation of the hemorrhagic fluid in the recirculation line (150) can pass through the suction chamber (111) of the filtration device (110) in a direction from the outlet (140b) of the treatment bag (140) to the inlet (140a) of the treatment bag (140); - a suction line (120), the suction line being fluidly connected to the recirculation line (150) between the outlet (140b) of the treatment bag (140) and the inlet (111a) of the suction chamber (111) of the filtration device (110), so as to be able to supply the collected hemorrhagic fluid to the treatment unit (100) for filtration through the filtration membrane (113) of the filtration device (110), thereby removing a filtrate comprising compounds not required for autologous transfusion from the hemorrhagic fluid; - A blood transfusion line (170) fluidly connected to a recirculation line (150) between an outlet (140b) of the treatment bag (140) and an inlet (111a) of an inhalation chamber (111) of the filtration device (110), so as to be able to recover the treated hemorrhagic fluid contained in the treatment bag (140); - A discharge line (130) fluidly connected to an outlet (112b) of a discharge chamber (112) of the filtration device (110) for discharging the filtrate that has passed through the filtration membrane (113) from the inhalation chamber (111); Characterized in that the treatment unit further comprises: - A first flow rate regulating member (151) arranged for regulating the flow rate in the recirculation line (150) at the outlet (140b) of the treatment bag (140); - A dilution line (190) for delivering a dilution fluid into the treatment unit (100), the dilution line (190) being fluidly connected to the recirculation line (150) at a position between the outlet (140b) of the treatment bag (140) and the inlet (111a) of the inhalation chamber (111) of the filtration device (110); - A hematocrit sensor (154) arranged to measure the hematocrit level of the hemorrhagic fluid circulating in the treatment unit (100); And, the treatment system further comprises means for controlling the dilution line (190), the means being programmed to control the delivery of the dilution fluid into the treatment unit (100) according to the hematocrit level measured by the hematocrit sensor (154).

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