Device for extracorporeal treatment of blood and method for determining the loss of moisture in a membrane gas exchanger of a device for extracorporeal treatment of blood

Abstract

A method for determining a moisture loss in a membrane gas exchanger of a device for extracorporeal treatment of blood, comprising: obtaining a sweep gas flow (Q gas ) in a gas side (202) of the membrane gas exchanger (19); obtaining a saturated moisture content (C saturation_out ) at a gas outlet (19d) of the membrane gas exchanger (19); calculating a moisture loss (Q eccor ) depending on at least the sweep gas flow (Q gas ) and the saturated moisture content (C saturation_out ).

Description

TECHNICAL FIELD

[0001] The present invention relates to a device for extracorporeal treatment of blood, in particular a device provided with a membrane gas exchanger, for example for the purpose of removing CO2, and to a method for detecting the loss of moisture in a membrane gas exchanger of a device for extracorporeal treatment of blood. BACKGROUND

[0002] In the field of extracorporeal treatment of blood, in hemodialysis treatment, the blood of a patient and a treatment fluid, which is isotonic to the blood flow, are circulated in respective compartments of a hemodialyzer, so that impurities and undesired substances present in the blood (urea, creatinine, etc.) can migrate from the blood to the treatment fluid by diffusion transfer. The ionic concentration of the treatment fluid is chosen so as to correct the ionic concentration of the patient's blood. In a treatment by hemodiafiltration, a convective transfer by ultrafiltration, generated by a positive pressure difference established between the blood side and the treatment fluid side of the membrane of a hemodiafiltration filter, is added to the diffusion transfer obtained by dialysis.

[0003] In the field of extracorporeal blood treatment and therapy of blood, membrane gas exchangers are used for extracorporeal membrane oxygenation (ECMO) and / or extracorporeal CO2 removal (ECCO2R). While initially used for dedicated systems, the development of extracorporeal CO2 removal has recently allowed the introduction of membrane gas exchangers in dialysis systems for continuous renal replacement therapy (CRRT). Carbon dioxide CO2 is removed by diffusion through a gas exchange membrane from the blood into a gas (sweep gas flow) flowing on the other membrane side. CRRT systems can provide ECCO2R therapy (stand-alone ECCO2R), as well as CRRT and ECCO2R combined in the same blood circuit.

[0004] During CO2 removal, while CO2 is extracted, part of the water is transferred and evaporated into the sweep gas flow, causing a loss of both heat and moisture of the blood compartment.

[0005] The loss of moisture is neglected in prior art devices and introduces a system bias in the same order of magnitude as the system fluid balance accuracy in the patient fluid balance.

[0006] In fact, the evaporation of water into the sweep gas flow has two main consequences:

[0007] - it adds an uncontrolled amount to the patient fluid removal;

[0008] - it cools the blood (significant latent heat associated with water evaporation).

[0009] The fluid balance aspect can have clinical consequences since the water loss through the gas exchanger can be in the range of several hundreds of milliliters per day and therefore it is comparable to the claimed accuracy of the fluid balance system of the device.

[0010] It is therefore an object of the present application to provide a device for extracorporeal treatment of blood configured to provide a correct fluid balance for a patient during extracorporeal blood treatment to avoid or reduce the risk of clinical consequences for the patient.

[0011] In particular, it is an object of the present application to improve the accuracy of the existing fluid balance system of a device for extracorporeal treatment of blood provided with a gas exchanger for CO2 removal purposes.

[0012] Moreover, it is an object to provide a device capable of ensuring a correct fluid balance which does not require any additional and special components / devices. SUMMARY

[0013] At least one of the above objects is substantially achieved by a device for extracorporeal treatment of blood and a method for determining the water loss in a membrane gas exchanger of the device according to embodiments of the present application.

[0014] The device and the method according to the present application are described hereinafter and are capable of achieving one or more of the above objects.

[0015] A first aspect relates to a device for extracorporeal treatment of blood comprising:

[0016] optionally a blood treatment unit;

[0017] an extracorporeal blood circuit, optionally coupled to the blood treatment unit;

[0018] a blood pump configured to be coupled to a pump section of the extracorporeal blood circuit;

[0019] optionally a fluid circuit coupled to the blood treatment unit;

[0020] at least one membrane gas exchanger operatively coupled to the extracorporeal blood circuit and / or to the fluid circuit to exchange gas with blood flowing in the extracorporeal blood circuit and / or with fluid flowing in the fluid circuit, wherein the membrane gas exchanger comprises: a blood side or fluid side having a blood inlet or fluid inlet and a blood outlet or fluid outlet in fluid communication with the extracorporeal blood circuit or the fluid circuit; and a gas side across which a sweep gas is passed and having a gas inlet and a gas outlet;

[0021] a control unit configured to command the execution of a task comprising at least the steps of:

[0022] - exchanging gas between blood or fluid flowing through a blood side or fluid side of a membrane gas exchanger and a sweep gas flowing through a gas side of the membrane gas exchanger;

[0023] - determining a water loss of the blood or fluid occurring in the membrane gas exchanger due to the gas exchange;

[0024] - signaling a notification of the water loss and / or at least partially compensating for the water loss, optionally automatically signaling a notification of the water loss and / or at least partially compensating for the water loss.

[0025] A second aspect relates to a method for exchanging gas in a device for extracorporeal treatment of blood, wherein the device for extracorporeal treatment of blood comprises:

[0026] optionally, a blood treatment unit;

[0027] an extracorporeal blood circuit, optionally coupled to the blood treatment unit;

[0028] a blood pump configured to be coupled to a pump section of the extracorporeal blood circuit;

[0029] optionally, a fluid circuit coupled to the blood treatment unit;

[0030] at least one membrane gas exchanger operatively coupled to the extracorporeal blood circuit and / or the fluid circuit to exchange gas with blood flowing in the extracorporeal blood circuit and / or with fluid flowing in the fluid circuit, wherein the membrane gas exchanger comprises a blood side or fluid side in fluid communication with the extracorporeal blood circuit or the fluid circuit and a gas side across which a sweep gas is flowing;

[0031] wherein the method comprises:

[0032] - exchanging gas between blood or fluid in the membrane gas exchanger and the sweep gas;

[0033] - determining a water loss of the blood or fluid occurring in the membrane gas exchanger due to the gas exchange;

[0034] - signaling a notification of the water loss and / or at least partially compensating for the water loss, optionally automatically signaling a notification of the water loss and / or at least partially compensating for the water loss.

[0035] A third aspect relates to a method for determining a water loss in a membrane gas exchanger of a device for extracorporeal treatment of blood, wherein the device for extracorporeal treatment of blood comprises:

[0036] optionally, a blood treatment unit;

[0037] an extracorporeal blood circuit, optionally coupled to the blood treatment unit;

[0038] a blood pump configured to be coupled to a pump section of the extracorporeal blood circuit;

[0039] optionally a fluid circuit coupled to the blood treatment unit;

[0040] at least one membrane gas exchanger operatively coupled to the extracorporeal blood circuit to exchange gas with blood flowing in the extracorporeal blood circuit and / or with fluid flowing in the fluid circuit, wherein the membrane gas exchanger comprises a blood side or fluid side in fluid communication with the blood circuit or the fluid circuit and a gas side across which a sweep gas is passed;

[0041] wherein the method comprises:

[0042] - obtaining a flow rate of the sweep gas in the gas side of the membrane gas exchanger;

[0043] - calculating a water loss of the blood or fluid at least from the flow rate of the sweep gas.

[0044] In a fourth aspect according to any of the preceding aspects, the membrane gas exchanger is a carbon dioxide CO2 remover and / or the exchanged gas is carbon dioxide (CO2) and is removed from the blood or fluid; optionally wherein the membrane gas exchanger is an oxygenator and / or the exchanged gas is oxygen and is added to the blood or fluid; optionally wherein the membrane gas exchanger is a carbon dioxide CO2 remover and an oxygenator and / or carbon dioxide (CO2) is removed from the blood or fluid while oxygen is added to the blood or fluid.

[0045] In a fifth aspect according to any of the preceding aspects, the membrane gas exchanger comprises a gas permeable membrane separating the blood side or fluid side from the gas side, wherein optionally the gas permeable membrane comprises a plurality of hollow fibers.

[0046] In a sixth aspect according to the preceding aspects, a sweep gas source is connected to the gas inlet to supply sweep gas through the gas side of the membrane gas exchanger, wherein optionally the sweep gas is dry gas or humidified gas, wherein optionally the sweep gas is air, optionally dry air or humidified air, molecular oxygen or a mixture of air and molecular oxygen; wherein optionally a device for humidifying the sweep gas is placed between the sweep gas source and the gas inlet.

[0047] In a seventh aspect according to any of the preceding aspects, the extracorporeal blood circuit comprises a blood withdrawal line and a blood return line connectable to a patient, wherein the blood withdrawal line is connected to the blood inlet of the membrane gas exchanger and the blood return line is connected to the blood outlet of the membrane gas exchanger.

[0048] In an eighth aspect according to any of the preceding aspects one to six, the device comprises a blood treatment unit, wherein the extracorporeal blood circuit is coupled to the blood treatment unit.

[0049] In a ninth aspect according to the preceding aspect eight, the blood treatment unit comprises a primary chamber and a secondary chamber separated by a semi-permeable membrane, wherein the extracorporeal blood circuit comprises a blood withdrawal line connected to an inlet of the primary chamber and a blood return line connected to an outlet of the primary chamber; optionally, wherein the fluid circuit is connected to the secondary chamber; optionally, wherein the fluid circuit comprises an effluent fluid line connected to an outlet of the secondary chamber and a dialysis fluid line connected to an inlet of the secondary chamber; optionally, wherein in at least one configuration, the fluid circuit presents a closed loop connected to the secondary chamber.

[0050] In a tenth aspect according to any of the preceding aspects eight or nine, the membrane gas exchanger is placed on the blood return line or on the blood withdrawal line and / or the membrane gas exchanger is placed on the fluid circuit, optionally on the closed loop.

[0051] In an eleventh aspect according to any of the preceding aspects, determining the water loss of the blood comprises:

[0052] - obtaining a sweep gas flow rate in the gas side of the membrane gas exchanger;

[0053] - optionally, obtaining a water saturation content at the gas outlet of the membrane gas exchanger;

[0054] - optionally, obtaining a water saturation content at the gas inlet of the membrane gas exchanger;

[0055] - calculating the water loss of the blood or of the fluid at least as a function of the sweep gas flow rate and optionally of the water saturation content at the gas outlet and optionally of the water saturation content at the gas inlet.

[0056] In a twelfth aspect according to the preceding aspect eleven, determining the water loss of the blood further comprises:

[0057] - obtaining a relative humidity at the gas outlet of the membrane gas exchanger;

[0058] - optionally, obtaining a relative humidity at the gas inlet of the membrane gas exchanger;

[0059] - calculating the water loss of the blood also as a function of the relative humidity at the gas outlet and optionally of the relative humidity at the gas inlet.

[0060] In a thirteenth aspect according to any of the preceding aspects eleven or twelve, obtaining the sweep gas flow rate comprises:

[0061] - direct or indirect measurement of the purge gas flow; or

[0062] - collecting a prescribed value of the purge gas flow.

[0063] In a fourteenth aspect according to any of the preceding aspects eleven to thirteen, obtaining the saturation moisture content at the gas outlet comprises:

[0064] - obtaining a blood inlet temperature or fluid inlet temperature at the blood inlet or fluid inlet of the membrane gas exchanger;

[0065] - calculating the saturation moisture content from the blood inlet temperature or fluid inlet temperature;

[0066] Optionally, if the purge gas is humidified, wherein obtaining the saturation moisture content at the gas inlet comprises:

[0067] - obtaining a humidification temperature, wherein optionally the humidification temperature is measured or calculated or a constant default value, optionally room temperature;

[0068] - calculating the saturation moisture content at the gas inlet from the humidification temperature.

[0069] In a fifteenth aspect according to the preceding aspects, the blood inlet temperature or fluid inlet temperature is measured or calculated or is a constant default value.

[0070] In a sixteenth aspect according to any of the preceding aspects twelve or thirteen to fifteen, when according to aspect twelve, obtaining the relative humidity at the gas outlet comprises:

[0071] - deriving the relative humidity at the gas outlet from the type of the membrane gas exchanger and optionally the purge gas flow; or

[0072] - assuming the relative humidity at the gas outlet to be equal to 100% if the type of the membrane gas exchanger is unknown, for example;

[0073] wherein, optionally, obtaining the relative humidity at the gas inlet comprises:

[0074] - assuming the relative humidity at the gas inlet to be equal to 100% if the purge gas is humidified;

[0075] - assuming the relative humidity at the gas inlet to be equal to 0% if the purge gas is not humidified.

[0076] In a seventeenth aspect according to any of the preceding aspects, at least partially compensating for the water loss of the blood or fluid comprises adding water to the extracorporeal blood or fluid circuit, optionally via a solution, optionally via a glucose or electrolyte / infusion solution.

[0077] In an eighteenth aspect according to any of the preceding aspects, at least partially compensating for the water loss of the blood or fluid comprises reducing the net fluid removal from the extracorporeal blood circuit.

[0078] In a nineteenth aspect according to any of the preceding aspects, when according to aspect nine, the fluid circuit comprises an outflow fluid line connected to the outlet of the secondary chamber and an outflow pump running on the outflow fluid line, wherein at least partially compensating for the water loss of the blood or fluid comprises adjusting the outflow pump.

[0079] In a twentieth aspect according to the preceding aspects, the control unit is configured to adjust the outflow pump by adjusting, optionally reducing, the pump speed of the outflow pump in dependence on the calculated water loss of the blood or fluid.

[0080] In a twenty-first aspect according to any of the preceding aspects, a water source, optionally a solution source, optionally a glucose solution or electrolyte / infusion solution, is connected to the extracorporeal blood circuit by a water line, directly or indirectly, e.g. through a fluid circuit or infusion line, wherein a water pump runs on the water line, wherein at least partially compensating for the water loss of the blood or fluid comprises infusing water into the extracorporeal blood circuit, optionally via a solution, optionally via a glucose solution or electrolyte / infusion solution; optionally, wherein the water or solution infusion is not balanced by the outflow pump.

[0081] In a twenty-second aspect according to the preceding aspects, the control unit is configured to adjust the flow of water or solution infused into the extracorporeal blood circuit in dependence on the calculated water loss of the blood.

[0082] In a twenty-third aspect according to the preceding aspects twenty-one or twenty-two, at least partially compensating for the water loss comprises adjusting the water pump.

[0083] In a twenty-fourth aspect according to aspects twenty-one or twenty-two or twenty-three, the water line terminates in the extracorporeal blood circuit, optionally at a mixing site to minimize hemolysis.

[0084] In a twenty-fifth aspect according to the preceding aspect twenty-four, the water line is connected to the blood circuit between the blood pump and the membrane gas exchanger, optionally between the blood pump and the blood treatment unit, and / or downstream of the membrane gas exchanger.

[0085] In a twenty-sixth aspect according to any of the aspects twenty-one to twenty-three, when according to aspect nine, the fluid circuit comprises: a dialysis fluid line connected to the inlet of the secondary chamber and to a source of dialysate; and optionally at least one dialysis pump coupled to or configured to be coupled to a pump section of the dialysis fluid line; wherein the water line terminates in the dialysis fluid line.

[0086] In a twenty-seventh aspect according to the foregoing aspect twenty-six, the water line is connected to the dialysis fluid line at a connection point located between the dialysis pump and the blood treatment unit.

[0087] In a twenty-eighth aspect according to any of the foregoing aspects twenty-one to twenty-three, an infusion circuit, the infusion circuit comprising: one or more infusion lines of substitution fluid connected to the extracorporeal blood circuit; and optionally at least one infusion pump coupled to or configured to be coupled to a pump section of the infusion line; wherein the water line terminates in at least one of the infusion lines.

[0088] In a twenty-ninth aspect according to the foregoing aspects, the water line is connected to the infusion line at a connection point located between the infusion pump and the extracorporeal blood circuit.

[0089] In a thirtieth aspect according to the foregoing aspects twenty-eight or twenty-nine, the infusion line is connected to the extracorporeal blood circuit between the blood pump and the membrane gas exchanger (optionally between the blood pump and the blood treatment unit); optionally wherein the infusion line is connected upstream of the blood pump.

[0090] In a thirty-first aspect according to the foregoing aspects twenty-eight or twenty-nine, the infusion line is connected to the blood circuit downstream of the membrane gas exchanger.

[0091] In a thirty-second aspect, the one or more signals informing of the water loss are visual signals indicative of a value of said water loss; wherein optionally said signals are shown on a display, optionally on a display of a control panel connected to the control unit or on a display of a remote device.

[0092] In a thirty-third aspect, determining the water loss of the blood comprises:

[0093] - obtaining a sweep gas flow rate of a gas side of the membrane gas exchanger;

[0094] - obtaining a blood inlet temperature or fluid inlet temperature at a blood inlet or fluid inlet of the membrane gas exchanger;

[0095] - obtaining a room temperature;

[0096] - calculating the water loss of the blood or fluid at least from the sweep gas flow rate and the blood inlet temperature or fluid inlet temperature, and optionally the room temperature.

[0097] In a thirty-fourth aspect according to the previous aspects, determining the water loss of the blood comprises:

[0098] - calculating the water rate at the gas outlet as a function of the blood inlet temperature or the fluid inlet temperature;

[0099] - calculating the water rate at the gas inlet as a function of the room temperature;

[0100] - calculating the water loss of the blood or fluid as the difference between the water rate at the gas outlet and the water rate at the gas inlet.

[0101] In a thirty-fifth aspect according to the previous aspects, the parameters related to the water rate at the gas outlet and the blood inlet temperature or the fluid inlet temperature are derived by calculation, and the parameters related to the water rate at the gas inlet and the room temperature are derived by experimental tests. BRIEF DESCRIPTION OF DRAWINGS

[0102] Aspects of the present application are illustrated in the attached drawings, which are provided by way of non-limiting examples, in which:

[0103] Figure 1 a schematic view of a device for extracorporeal treatment of blood is shown;

[0104] Figure 2 a schematic view of an alternative embodiment of a device for extracorporeal treatment of blood is shown;

[0105] Figure 3 a schematic view of a further embodiment of a device for extracorporeal treatment of blood is shown;

[0106] Figure 4 is a flow chart of the method of the present application. DETAILED DESCRIPTION

[0107] Figure 1 , Figure 2 and Figure 3 A non-limiting embodiment of a device 1 for extracorporeal treatment of blood is shown in Figure 1 , Figure 2 and Figure 3 In the following description and drawings, identical components are identified by the same reference numerals.

[0108] In Figure 1In the middle, a device 1 for extracorporeal treatment of blood is shown, comprising a blood treatment unit 2 (e.g. a hemofilter, an ultrafilter, a hemodiafilter, a dialyzer, a plasmapheresis filter, etc.) having a primary chamber 3 and a secondary chamber 4 separated by a semipermeable membrane 5; depending on the treatment, the semipermeable membrane 5 of the blood treatment unit 2 can be selected to have different characteristics and properties. A blood withdrawal line 6 is connected to an inlet 3a of the primary chamber 3, and a blood return line 7 is connected to an outlet 3b of the primary chamber 3. In use, the blood withdrawal line 6 and the blood return line 7 are connected to a needle or a catheter or other access device (not shown) which is then placed in fluid communication with the vascular system of a patient “P” so that blood can be withdrawn through the blood withdrawal line 6, flow through the primary chamber 3, and then be returned to the vascular system of the patient through the blood return line 7. An air separator (e.g. a deaeration chamber 8) can be present on the blood return line 7. Furthermore, a safety return clamp 9 controlled by a control unit 10 can be present on the blood return line 7 downstream of the deaeration chamber 8. A bubble sensor can be present, e.g. associated with the deaeration chamber 8 or coupled to the portion of the line 7 between the deaeration chamber 8 and the return clamp 9: the bubble sensor (if present) is connected to the control unit 10 and sends a signal to the control unit 10 in case one or more bubbles above a safety threshold are detected, to make the control unit 10 cause the return clamp 9 to close. The blood flow through the blood lines is controlled by a blood pump 11 (e.g. a peristaltic blood pump) acting on the blood withdrawal line 6 or on the blood return line 7. Figure 1 、 Figure 2 and Figure 3 Embodiments of the device 1 show the blood pump 11 coupled to the pump section of the withdrawal line 6.

[0109] The operator can input a set value of the blood flow rate Q B through the user interface, and the control unit 10 is configured to control the blood pump 11 during the treatment based on the set blood flow rate Q B .

[0110] The control unit 10 can comprise a digital processor (CPU) with memory (or memories), an analog type circuit or a combination of one or more digital processing units and one or more analog processing circuits. In the present description and claims, it is indicated that the control unit 10 is "configured" or "programmed" to perform a step: in practice, this can be achieved by any means which allows to configure or program the control unit 10. For example, in case the control unit 10 comprises one or more CPUs, one or more programs are stored in a suitable memory: the one or more programs contain instructions which, when executed by the control unit 10, cause the control unit 10 to perform the steps described and / or claimed in connection with the control unit 10. Alternatively, if the control unit 10 is of the analog type, the circuit of the control unit 10 is designed to comprise a circuit configured to process electrical signals in use to perform the steps of the control unit 10 disclosed herein.

[0111] The effluent fluid line 12 or waste dialysis fluid line is connected at one end to the fluid outlet 4b of the secondary chamber 4 and at the other end to a waste, which can be an effluent fluid container or a drain pipe which collects the fluid extracted from the secondary chamber. An effluent pump 13 operating on the effluent fluid line 12 regulates the flow rate Q eff .

[0112] Figure 1 The apparatus comprises a dialysis fluid line 14 connected at one end to a source of fresh dialysis fluid and at the other end to the fluid inlet 4a of the secondary chamber 4 of the treatment unit 2 to supply fresh dialysis fluid to the secondary chamber 4. A dialysis fluid pump 15 operates on the dialysis fluid line 14 under the control of the control unit 10 to supply fluid from a dialysis fluid container (not shown) to the secondary chamber 4 at a flow rate Q dial .

[0113] The effluent fluid line 12, the dialysis fluid line 14 and the secondary chamber 4 of the blood treatment unit 2 are part of a fluid circuit of the apparatus 1.

[0114] Figure 1 An embodiment of the apparatus presents an infusion line 16 connected to the blood withdrawal line 6 between the blood pump 11 and the treatment unit 2. This infusion line 16 supplies replacement fluid from an infusion fluid container 17 connected at one end of the infusion line 16. Note that, in alternative or in addition to the infusion line 16, Figure 1The apparatus of the'1 1 1 patent can also include a post-dilution fluid line (not shown) connecting the infusion fluid container to the blood return line 7 and / or a pre-blood pump infusion line 16' having its own infusion fluid container 17'. Furthermore, an infusion pump 18 operates on the infusion line 16 and an infusion pump 18' operates on the pre-blood pump infusion line 16' to regulate the respective flow Q rep Note that in case of two or more infusion lines (pre-dilution and post-dilution and pre-blood pump infusion line 16'), each infusion line can be provided with a respective infusion pump.

[0115] The apparatus 1 for extracorporeal treatment of blood further comprises a membrane gas exchanger 19 placed on the blood return line 7, i.e. downstream of the blood treatment unit 2 with respect to the blood flow direction during treatment. The membrane gas exchanger 19 comprises a gas permeable membrane 200 separating a blood side 201 and a gas side 202. A first section 7a of the blood return line 7 from the blood treatment unit 2 is connected to a blood inlet 19a of the blood side 201 of the membrane gas exchanger 19 and a second section 7b of the blood return line 7 connected to the needle or catheter is connected to a blood outlet 19b of the blood side 201 of the membrane gas exchanger 19. The gas side 202 of the membrane gas exchanger 19 is provided with a respective gas inlet 19c and gas outlet 19d for a purge gas, e.g. air or molecular oxygen or a mixture of air and molecular oxygen.

[0116] The internal structure of the membrane gas exchanger 19 can be known per se. The gas permeable membrane 200 separates the blood side 201 and the gas side 202. The gas permeable membrane 200 can comprise a plurality of hollow fibers defining said membrane. A purge or ventilation gas, e.g. oxygen, air, dry air, humidified air, passes through the interior of the hollow fibers (gas side), while blood passes around the hollow fibers (blood side) to accomplish gas exchange by diffusion. The membrane gas exchanger 19 is operatively coupled to the extracorporeal blood circuit to exchange gas with blood flowing in the extracorporeal blood circuit. Figure 1 、 Figure 2 and Figure 3 The membrane gas exchanger 19 of the disclosed embodiments is a CO2 remover. Carbon dioxide CO2 diffuses from the blood side 201 into the gas for treatment. Figure 1 The apparatus 1 of the'1 1 1 patent can deliver independent CO2 removal as well as dialysis and CO2 removal combined in the same blood circuit.

[0117] In other embodiments, the membrane gas exchanger 19 can be an oxygenator configured to add oxygen to the blood or can be configured to add oxygen to the blood while removing carbon dioxide CO2.

[0118] A source of purge gas 20, like a gas cylinder, is connected to the gas inlet 19c to supply purge gas through the gas side of the membrane gas exchanger 19.

[0119] In a variant embodiment, the membrane gas exchanger 19 can be placed on the blood withdrawal line 6.

[0120] Optionally, a blood warmer 21 can be placed on the blood return line 7 between the membrane gas exchanger 19 and the bubble trap 8.

[0121] The blood withdrawal line 6, the blood return line 7, the main chamber 3 of the treatment unit 2 and the blood side 201 of the membrane gas exchanger 19 form part of an extracorporeal blood circuit of the apparatus 1. The infusion lines 16, 16' form part of an infusion circuit of the apparatus 1.

[0122] The blood pump 11, the effluent pump 13, the dialysis fluid pump 15, the infusion pumps 18, 18' and possibly other pumps are operatively connected to a control unit 10 which controls said pumps. The control unit 10 is also operatively connected to sensors (e.g. flow sensors and / or pressure sensors) on the blood circuit and / or the fluid circuit and / or the infusion circuit. The control unit 10 is also operatively connected to clamps and valves, such as the return clamp 9. The control unit 10 is also connected to a user interface (not shown), e.g. a graphical user interface, which receives inputs from an operator and displays outputs of the apparatus. For example, the graphical user interface can comprise a touch screen, a display screen and hard keys for inputting user inputs or a combination thereof. During extracorporeal blood treatment, the control unit 10 is configured to control at least the pumps 11, 13, 15, 18, 18' to ensure that a preset patient net fluid removal is achieved over the course of the treatment time, e.g. a patient net fluid removal required by a prescription provided to the control unit 10 via the user interface.

[0123] Figure 1 The apparatus 1 of Fig. 1 further comprises a water line 22 which is connected to a source 23 of water in a solution (e.g. a glucose solution in a bag) and to the infusion line 16 at a connection point located between the infusion pump 18 and the extracorporeal blood circuit. A water pump 24 operates on the water line 22 to regulate the flow rate Q water of water through the water line 22. According to a variant embodiment (dashed lines in Fig. 1), the water line 22 is directly connected to the extracorporeal blood circuit between the blood pump 11 and the blood treatment unit 2. Figure 1

[0124] Another water line 22' connected to a water source 23' and coupled to a water pump 24' is connected to the dialysis fluid line 14 at a connection point located between the dialysis pump 15 and the fluid inlet 4a of the secondary chamber 4 of the blood treatment unit 2.

[0125] ​Figure 1 The device 1 is configured to deliver continuous renal replacement therapy (CRRT) in combination with ECCO2R or to provide ECCO2R therapy alone.

[0126] Control unit 10 is configured to control the device to treat patient “P” via extracorporeal blood treatment unit 2 and membrane gas exchanger 19. Control unit 10 is also configured to command the execution of tasks according to the method of the invention, taking into account the loss of blood moisture Q due to CO2 removal in membrane gas exchanger 19. eccor ( Figure 4 ).

[0127] The task includes at least the following steps:

[0128] - Removes gas (CO2) from the blood flowing through the blood side of the membrane gas exchanger 19;

[0129] - Determine the blood water loss Q that occurs in the membrane gas exchanger 19 due to gas exchange (i.e., water evaporation into purge gas). eccor ;

[0130] - Signaling of moisture loss and / or at least partially compensating for said moisture loss Q eccor .

[0131] Gas is removed from the blood by passing a purge gas or ventilation gas (e.g., oxygen, air, dry air, humidified air) through the interior of the hollow fibers of the membrane gas exchanger 19 (gas side 202), while the blood passes around the hollow fibers (blood side 201) to complete the gas exchange by diffusion.

[0132] To determine the moisture loss Q in membrane gas exchanger 19 eccor The control unit 10 is configured to perform calculations using the following formula:

[0133] i)Q eccor =Q gas x C saturation_out x(RH outlet / 100)

[0134] in:

[0135] Q eccor Water loss from the blood in gas exchanger 19;

[0136] Q gas The purge gas flow rate through gas exchanger 19;

[0137] C saturation_out Saturated moisture content at the gas outlet 19d;

[0138] RH outlet Relative humidity at gas outlet 19d.

[0139] In the embodiment, the gas flow rate Q gas The flow rate (L / min) can be measured directly, for example, by a flow sensor (not shown) operatively connected to the control unit 10. In an embodiment, the gas flow rate Q gas The value may be collected from the memory of the control unit 10 or entered by the operator, for example, via a keyboard or touchscreen, after being asked by the operator.

[0140] In the embodiment, the saturated moisture content C at the gas outlet 19d is... saturation_out This is derived under the assumption that the gas leaves the membrane gas exchanger 19 at the same temperature as the blood inflow and that the blood temperature from the patient "P" or the extracorporeal blood circuit at the blood inlet 19a of the membrane gas exchanger 19 is known. In an embodiment, a temperature sensor is placed at the blood inlet 19a and measures the blood inlet temperature T. in In one embodiment, a temperature sensor may be placed at the gas outlet 19d. In another embodiment, different temperatures (e.g., temperature from the patient "P" or temperature from different points in the extracorporeal blood circuit) are measured, and the blood inlet temperature T... in The control unit 10 calculates the heat loss using a mathematical model that integrates atmospheric and / or fluid exchange. In this embodiment, the constant default temperature can be considered as the blood inlet temperature T. in Then, the saturated water content C saturation_out It is based on the blood inlet temperature T in It is used for calculation.

[0141] In the embodiment, the relative humidity (RH) at gas outlet 19d is... outlet (%) is based on the type of membrane gas exchanger 19 and the purge gas flow rate Q. gas Derived; it is a value associated with the type of membrane gas exchanger 19. For large gas flow rates Q gas The combined small membrane gas exchanger 19 may have a relative humidity (RH) of less than 100%. In embodiments, for example, if the type of membrane gas exchanger 19 is unknown, the relative humidity (RH) may be... outlet It is set to equal 100%.

[0142] In this embodiment, the purge gas entering the gas inlet 19c is humidified, for example, by means of a device placed between the purge gas source 20 and the gas inlet 19c. Therefore, the control unit 10 is configured to also take into account the humidification and perform calculations using the following formula:

[0143] ii)Q eccor =Qgas x((C saturation_out x(RH outlet / 100))-(C saturation_in x(RH inlet / 100)))

[0144] in:

[0145] Q eccor Water loss from the blood in gas exchanger 19;

[0146] Q gas The purge gas flow rate through gas exchanger 19;

[0147] C saturation_out Saturated moisture content at the gas outlet 19d;

[0148] RH outlet Relative humidity at gas outlet 19d;

[0149] C saturation_in Saturated moisture content at gas inlet 19c;

[0150] RH inlet Relative humidity at gas inlet 19c.

[0151] Saturated moisture content C at gas inlet 19c saturation_in Calculated as humidification temperature T hum The function, usually room temperature T room The function of the room temperature T room It can be measured or calculated, or it can be a constant default value. If the purge gas is humidified, the relative humidity (RH) at the gas inlet 19c is assumed to be... inlet It equals 100%, or if the purge gas is not humidified, it is assumed to equal 0%.

[0152] In another embodiment, the control unit 10 is configured to also consider gas humidification when performing calculations using the following formula:

[0153] iii)Q eccor =[Q gas x(α(T in ))]–[Q gas x(β(T room ))]

[0154] in:

[0155] Q gas x(α(T in The water volume at the gas outlet is 19d.

[0156] Q gasx (β(T room ) is the amount of water at the gas inlet 19c;

[0157] T in is the blood temperature at the blood inlet 19a;

[0158] T room is the room temperature.

[0159] The functions a and β are derived by calculation and / or experimental tests, possibly having the following form:

[0160] 1) a(T in ) = (a + b x T in )

[0161] 2) β(T room ) = d + e x T room

[0162] Equations 1 and 2 can be derived from air moisture saturation tables or from experimental measurements.

[0163] Compensation of the water loss Q eccor can be achieved by adding water to the extracorporeal blood circuit and / or by reducing the net fluid removal from the extracorporeal blood circuit.

[0164] The control unit 10 can be configured to signal to alert the operator of the calculated loss Q eccor and to inform the operator of the calculated value. The control unit 10 can display such value on the screen of the control panel or can send a signal to a remote device, for example a laptop. This allows a possible medical intervention. The operator can adjust the net fluid removal prescription or provide infusion water to the extracorporeal blood circuit or directly into the patient "P" via a solution (for example, a dextrose solution or an electrolyte / infusion solution).

[0165] In embodiments, the control unit 10 is configured to automatically compensate by directly infusing water in the extracorporeal blood circuit or in the infusion line 16 via the water source 23, the water line 22 and the water pump 24 with the calculated water loss Q eccor . In embodiments, water is infused in the dialysis fluid line 14 via the water line 22', the water source 23' and the water pump 24'. The control unit 10 is configured to adjust the flow rate of water or solution infused in the extracorporeal blood circuit according to the calculated water loss Q eccor of blood. The water flow rate is adjusted by adjusting the speed of the water pump 24, 24'. In these embodiments, the speed of the effluent pump 13 is unchanged with respect to the standard treatment. The water can be infused as pure water or via a solution (for example, a dextrose solution or an electrolyte / infusion solution). The water or solution infusion is not equilibrated by the effluent pump 13.

[0166] In embodiments, when a glucose solution is used, the automatic infusion can be performed directly in the blood circuit of the patient "P".

[0167] If pure water is directly infused in the extracorporeal blood circuit, the water line 22 ends in the extracorporeal blood circuit at a mixing site to minimize hemolysis.

[0168] In embodiments, the compensation by reducing the net fluid removal from the extracorporeal blood circuit is achieved by adjusting the effluent pump 13. The control unit 10 is configured to adjust the flow rate of the water or glucose solution infused in the extracorporeal blood circuit according to the calculated water loss Q eccor The speed of the effluent pump 13 is automatically adjusted (e.g. decreased).

[0169] Figure 2 Different embodiments of the extracorporeal blood treatment 1 are shown. For Figure 1 The same reference signs are used for the same elements in the different embodiments. Figure 2 The extracorporeal blood treatment 1 of Fig. 1 does not comprise a blood treatment unit 2, but is only equipped with a membrane gas exchanger 19. The membrane gas exchanger 19 is the only device in the circuit, and the apparatus 1 is configured to deliver only an ECCO2R treatment (stand-alone ECCO2R).

[0170] The blood withdrawal line 6 is connected to the blood inlet 19a of the membrane gas exchanger 19, and the blood return line 7 is connected to the blood outlet 19b of the membrane gas exchanger 19.

[0171] The water line 22 is connected to a source 23 of water in a solution (e.g. a glucose solution in a bag), and to the extracorporeal blood circuit between the blood pump 11 and the membrane gas exchanger 19. A water pump 24 is operated on the water line 22 to adjust the flow rate Q water of water through the water line 22. According to a variant embodiment (not shown), the water line 22 is connected downstream of the membrane gas exchanger 19.

[0172] In this embodiment, the compensation of the water loss Q eccor is achieved by directly adding water to the extracorporeal blood circuit via a glucose solution through the water line 22. The control unit 10 is configured to adjust the flow rate of the water or glucose solution infused in the extracorporeal blood circuit according to the calculated water loss Q eccor of blood. The water flow rate is adjusted by adjusting the speed of the water pump 24.

[0173] Figure 3 Another embodiment of the extracorporeal blood treatment 1 is shown. For Figure 1 The same reference signs are used for the same elements in the different embodiments.

[0174] Figure 3 The extracorporeal blood treatment 1 of Fig. 1 does not comprise a blood treatment unit 2, but is only equipped with a membrane gas exchanger 19. The membrane gas exchanger 19 is the only device in the circuit, and the apparatus 1 is configured to deliver only an ECCO2R treatment (stand-alone ECCO2R).Figure 1 The difference in the embodiment is that the fluid circuit including the dialysis fluid line 14 and the outflow fluid line 12 includes a closed loop with a loop pump 100 connected to the sub-chamber 4, and the difference is that the membrane gas exchanger 19 is placed on the fluid circuit instead of the extracorporeal blood circuit.

[0175] Dialysis fluid line 14 includes a first line 101 connected to a fresh dialysate source (not shown). Effluent line 12 includes a second line 102 connected to a waste section (not shown). A bridging line 103 connects the dialysis fluid line 14 upstream of the first line 101 to the effluent line 12 downstream of the second line 102. Dialysis fluid line 14, effluent line 12, and bridging line 103 form a loop that exits from fluid outlet 4b and terminates at fluid inlet 4a. Valves and / or clamps (not shown) allow for changes in the configuration of the fluid loop. In one configuration, dialysate from a fresh dialysate source flows into the secondary chamber 4 in the dialys fluid line 14, while waste dialysate flows from the secondary chamber 4 into the effluent fluid line 12 and then into the waste section. In another configuration, dialysate is recirculated in a closed loop.

[0176] exist Figure 3 In one embodiment, the membrane gas exchanger 19 is placed on the dialysis fluid line 14 between the first line 101 and the fluid inlet 4a. The membrane gas exchanger 19 includes a fluid side 201 and a gas side 202, the fluid side 201 having a fluid inlet 19a and a fluid outlet 19b in fluid communication with the fluid loop, purge gas crossing the gas side 202, and the gas side 202 having a gas inlet 19c and a gas outlet 19d.

[0177] In this embodiment, carbon dioxide (CO2) moves from the blood in the main chamber 3 of the blood treatment unit 2 to the recirculated dialysate in the secondary chamber 4 of the blood treatment unit 2 in the form of dissolved gas and / or bicarbonate. Then, in the membrane gas exchanger 19, gas is exchanged between the fluid flowing through the fluid side 201 of the membrane gas exchanger 19 and the purge gas flowing through the gas side 202 of the membrane gas exchanger 19. In the membrane gas exchanger 19, carbon dioxide (CO2) moves from the recirculated dialysate in the fluid side 201 to the purge gas in the gas side 202.

[0178] The determination of moisture loss in membrane gas exchanger 19 is essentially the same as disclosed above. Control unit 10 is configured to measure the calculated moisture loss Q via water line 22, water source 23, and water pump 24. eccor Water is automatically compensated by being directly injected into the extracorporeal blood circuit, and / or water is injected into the dialysis fluid line 14 via water line 22', water source 23' and water pump 24'.

[0179] While this application has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the application is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. An apparatus for extracorporeal treatment of blood, comprising: Extracorporeal blood circuit; A blood pump (11) is configured to be coupled to the pump section of the extracorporeal blood circuit; At least one membrane gas exchanger (19) is operatively coupled to the extracorporeal blood circuit to exchange gases with blood flowing in the extracorporeal blood circuit, wherein the membrane gas exchanger (19) includes: a blood side (201) having a blood inlet (19a) and a blood outlet (19b) in fluid communication with the extracorporeal blood circuit; and a gas side (202) through which purge gas passes and the gas side (202) has a gas inlet (19c) and a gas outlet (19d); Control unit (10) is configured to instruct the execution of a task, the task comprising at least the following steps: - Gas exchange occurs between the blood flowing through the blood side (201) of the membrane gas exchanger (19) and the purge gas flowing through the gas side (202) of the membrane gas exchanger (19); - Determine the blood water loss (Q) that occurs in the membrane gas exchanger (19) due to gas exchange. eccor ); - signaling a notification of the water loss (Q eccor ) and / or at least partially compensating for the water loss (Q eccor ).

2. The apparatus according to claim 1, wherein, Determining the water loss of the blood includes: - obtaining a purge gas flow rate (Q gas ) in a gas side (202) of the membrane gas exchanger (19); - calculating the water loss (Q eccor ) of the blood at least as a function of the sweep gas flow rate (Q gas ).

3. The apparatus according to claim 2, wherein, Determining the water loss of the blood also includes: - obtaining a saturated moisture content (C saturation_out ) at the gas outlet (19d) of the membrane gas exchanger (19); wherein the water loss of the blood (Q eccor ) is calculated based on at least the purge gas flow (Q gas ) and the saturated water content (C saturation_out ) at the gas outlet (19d). eccor ) is calculated based on at least the purge gas flow (Q gas ) and the saturated water content (C saturation_out ) at the gas outlet (19d).

4. The apparatus according to claim 3, wherein, Determining the water loss of the blood also includes: - obtaining a saturated moisture content (C saturation_in ) at a gas inlet (19c) of the membrane gas exchanger (19); wherein the water loss of the blood (Q eccor ) is calculated at least from the purge gas flow (Q gas ), the saturated water content (C saturation_out ) at the gas outlet (19d) and the saturated water content (C saturation_in ) at the gas inlet (19c). eccor ) 5. The apparatus according to any one of claims 3 to 4, wherein, Determining the water loss of the blood also includes: - obtaining a relative humidity (RH) at a gas outlet (19d) of the membrane gas exchanger (19) outlet ) wherein the water loss of the blood (Q eccor ) is calculated based on at least the purge gas flow (Q gas ), the saturated water content (C saturation_out ) at the gas outlet (19d), the saturated water content (C saturation_in ) at the gas inlet (19c), and the relative humidity (RH outlet ) at the gas outlet (19d). eccor ) 6. The apparatus according to claim 5, wherein, Determining the water loss of the blood also includes: - obtaining a relative humidity (RH) at a gas inlet (19c) of the membrane gas exchanger (19) inlet ) wherein the water loss of the blood (Q eccor ) is calculated based on at least the purge gas flow (Q gas ), the saturated water content (C saturation_out ) at the gas outlet (19d), the saturated water content (C saturation_in ) at the gas inlet (19c), the relative humidity (RH outlet ) at the gas outlet (19d), and the relative humidity (RH inlet ) at the gas inlet (19c). eccor ) 7. The apparatus according to claim 2, wherein, obtaining the purge gas flow rate (Q gas ) comprises: - directly or indirectly measuring the purge gas flow (Q gas ) ; or - collecting a prescribed value of the purge gas flow rate (Q gas ).

8. The apparatus according to claim 3, wherein, obtaining the saturation moisture content (C saturation_out ) at the gas outlet (19d) comprises: - obtaining a blood inlet temperature (Tinlet) at the blood inlet (19a) of the membrane gas exchanger (19) in ), - calculating the saturated moisture content (C saturation_out ) at the gas outlet (19d) as a function of the blood inlet temperature (T in ).

9. The apparatus according to claim 8, wherein, The blood inlet temperature (T in ) is measured or calculated, or is a constant default value.

10. The apparatus according to claim 4, wherein, obtaining the saturation moisture content (C saturation_in ) at the gas inlet (19c) comprises: - obtaining a humidification temperature (T hum ), - calculating the saturated moisture content (C saturation_in ) at the gas inlet (19c) as a function of the humidification temperature (T hum ).

11. The apparatus according to claim 10, wherein, The humidification temperature (T hum ) is measured or calculated or is a constant default value.

12. The apparatus according to claim 5, wherein, obtaining a relative humidity (RH outlet ) at the gas outlet (19d) comprises: -Based on the type of the membrane gas exchanger (19) and the purge gas flow rate (Q) gas The relative humidity (RH) at the gas outlet (19d) is derived. outlet );or - assuming that the relative humidity (RH outlet ) at the gas outlet (19d) is equal to 100%.

13. The apparatus according to claim 6, wherein, obtaining a relative humidity (RH inlet ) at the gas inlet (19c) comprises: - if the purge gas is humidified, it is assumed that the relative humidity (RH inlet ) at the gas inlet (19c) is equal to 100%; or - if the purge gas is not humidified, it is assumed that the relative humidity (RH inlet ) at the gas inlet (19c) is equal to 0%. - if the purge gas is not humidified, it is assumed that the relative humidity (RH inlet ) at the gas inlet (19c) is equal to 0%.

14. The apparatus according to any one of claims 1 to 4, wherein, At least partially compensating for the water loss of the blood includes adding water to the extracorporeal blood circuit and / or reducing net fluid removal from the extracorporeal blood circuit.

15. The apparatus according to claim 14, wherein, Water is added to the extracorporeal blood circuit without using an effluent pump to achieve balance.

16. The apparatus according to any one of claims 1 to 4, comprising a water source (23, 23') directly or indirectly connected to the extracorporeal blood circuit via water lines (22, 22'), wherein, Water pumps (24, 24') operate on the water lines (22, 22'), wherein at least partially compensating for the water loss includes: infusing water into the extracorporeal blood circuit.

17. The apparatus according to claim 16, wherein, The water source (23, 23') is the source of the solution.

18. The apparatus according to claim 17, wherein, The source of the solution (23, 23') is a glucose solution or an electrolyte / infusion solution.

19. The apparatus according to claim 18, wherein, Water is infused into the extracorporeal blood circuit via the solution.

20. The apparatus according to claim 19, wherein, The control unit (10) is configured to adjust the flow rate (Q eccor ) of water or solution infused into the extracorporeal blood circuit as a function of the calculated water loss (Q water ) of the blood.

21. The apparatus according to claim 16, wherein, The water line (22) is directly connected to the extracorporeal blood circuit at the connection point.

22. The apparatus according to claim 21, wherein, The connection point is located downstream of the blood pump (11).

23. The apparatus of claim 16, further comprising an infusion circuit, the infusion circuit comprising: One or more infusion lines (16) for displacement fluid connected to the extracorporeal blood circuit; and at least one infusion pump (18) coupled to or configured to be coupled to a pump section of the infusion lines (16); wherein the water line (22) terminates at at least one of the infusion lines (16).

24. The apparatus according to claim 1, wherein, Determining the water loss of the blood includes: - obtaining a purge gas flow (Q gas ) in a gas side (202) of the membrane gas exchanger (19); - obtaining a blood inlet temperature (T in ) at a blood inlet of the membrane gas exchanger (19); - obtaining room temperature (T room ); - calculating a water loss (Q gas ) of the blood at least as a function of the sweep gas flow rate (Q in ) and the blood inlet temperature (T eccor ).

25. The apparatus according to claim 24, wherein, calculating a water loss (Q eccor ) of the blood gas ) includes calculating the water loss (Q in ) of the blood based on at least the sweep gas flow (Q room ), the blood inlet temperature (T eccor ).

26. The apparatus according to any one of claims 24 to 25, wherein, Determining the water loss of the blood includes: - calculating the amount of water (Q gas- out) at the gas outlet as a function of the blood inlet temperature (T in ); - calculating the amount of water (Q gas-in ) at the gas inlet as a function of the room temperature (T room ); - calculating the water loss (Q eccor ) of the blood as the difference between the amount of water at the gas outlet and the amount of water at the gas inlet.

27. The apparatus according to claim 26, wherein, The water loss (Q eccor ) of the blood is calculated according to the following formula: Q eccor = [Q gas-out x (a(T in ))] - [Q gas-in x (b(T room ))] in: Q gas-out x(α(T in )) is the water quantity at the gas outlet (19d); Q gas-in x(β(T room ) is the amount of water at the gas inlet (19c); T in is the blood temperature at the blood inlet (19a); T room is the room temperature; and where the parameter related to the amount of water (Q gas-out ) at the gas outlet and the blood inlet temperature is derived from calculations, and the parameter related to the amount of water (Q gas-in ) at the gas inlet and the chamber temperature is derived from experimental tests.

28. The apparatus according to any one of claims 1 to 4, wherein, The membrane gas exchanger includes a gas-permeable membrane separating the blood side from the gas side and is a carbon dioxide (CO2) remover, and the exchanged gas is carbon dioxide (CO2) removed from the blood, wherein the gas-permeable membrane includes a plurality of hollow fibers.

29. The apparatus according to any one of claims 1 to 4, wherein, A purge gas source is connected to the gas inlet to supply purge gas through the gas side of the membrane gas exchanger, wherein the purge gas is a dry gas or a humidifying gas.

30. The apparatus according to claim 29, wherein, The purging gas is dry air or humidified air, molecular oxygen, or a mixture of air and molecular oxygen.

31. The apparatus according to claim 29, wherein, The device for humidifying the purge gas is placed between the purge gas source and the gas inlet.

32. An apparatus for extracorporeal treatment of blood, comprising: Blood processing unit (2); An external blood circuit is coupled to the blood processing unit (2); A blood pump (11) is configured to be coupled to the pump section of the extracorporeal blood circuit; A fluid circuit is coupled to the blood processing unit (2); At least one membrane gas exchanger (19) is operatively coupled to the extracorporeal blood circuit or the fluid circuit to exchange gas with blood flowing in the extracorporeal blood circuit or with fluid flowing in the fluid circuit, wherein the membrane gas exchanger (19) includes: a blood side or fluid side (201) having a blood inlet or fluid inlet (19a) and a blood outlet or fluid outlet (19b) in fluid communication with the extracorporeal blood circuit or the fluid circuit; and a gas side (202) through which purge gas passes and the gas side (202) has a gas inlet (19c) and a gas outlet (19d); Control unit (10) is configured to instruct the execution of a task, the task comprising at least the following steps: - The blood or fluid flowing through the blood side or fluid side (201) of the membrane gas exchanger (19) exchanges gases with the purge gas flowing through the gas side (202) of the membrane gas exchanger (19); - determining a water loss (Q eccor ) of the blood or fluid occurring in the membrane gas exchanger (19) due to the gas exchange; - signaling a notification of the water loss (Q eccor ) and / or at least partially compensating for the water loss (Q eccor ).

33. The apparatus according to claim 32, wherein, Determining the water loss of the blood or fluid includes: - obtaining a purge gas flow rate (Q gas ) in a gas side (202) of the membrane gas exchanger (19); - calculating the water loss (Q gas ) of the blood or fluid at least as a function of the sweep gas flow (Q eccor ).

34. The apparatus according to claim 33, wherein, Determining the water loss of the blood or fluid also includes: - obtaining a saturated moisture content (C saturation_out ) at the gas outlet (19d) of the membrane gas exchanger (19); wherein the water loss (Q eccor ) of the blood or fluid is calculated based on at least the purge gas flow (Q gas ) and the saturated water content (C saturation_out ) at the gas outlet (19d). eccor ) of the blood or fluid is calculated based on at least the purge gas flow (Q gas ) and the saturated water content (C saturation_out ) at the gas outlet (19d).

35. The apparatus according to claim 34, wherein, Determining the water loss of the blood or fluid also includes: - obtaining a saturated moisture content (C saturation_in ) at a gas inlet (19c) of the membrane gas exchanger (19); Among them, the water loss (Q) of the blood or fluid is calculated. eccor This includes at least based on the purge gas flow rate (Q) gas The saturated moisture content (C) at the gas outlet (19d) saturation_out ) and the saturated moisture content (C) at the gas inlet (19c). saturation_in To calculate the water loss (Q) of the blood or fluid. eccor ).

36. The apparatus according to any one of claims 34 to 35, wherein, Determining the water loss of the blood or fluid also includes: - obtaining a relative humidity (RH) at a gas outlet (19d) of the membrane gas exchanger (19) outlet ) Among them, the water loss (Q) of the blood or fluid is calculated. eccor This includes at least based on the purge gas flow rate (Q) gas The saturated moisture content (C) at the gas outlet (19d) saturation_out The saturated moisture content (C) at the gas inlet (19c) saturation_in The relative humidity (RH) at the gas outlet (19d) and the relative humidity at the gas outlet (19d) outlet To calculate the water loss (Q) of the blood or fluid. eccor ).

37. The apparatus according to claim 36, wherein, Determining the water loss of the blood or fluid also includes: - obtaining a relative humidity (RH) at a gas inlet (19c) of the membrane gas exchanger (19) inlet ) Among them, the water loss (Q) of the blood or fluid is calculated. eccor This includes at least based on the purge gas flow rate (Q) gas The saturated moisture content (C) at the gas outlet (19d) saturation_out The saturated moisture content (C) at the gas inlet (19c) saturation_in The relative humidity (RH) at the gas outlet (19d) outlet The relative humidity (RH) at the gas inlet (19c) and the relative humidity (RH) inlet To calculate the water loss (Q) of the blood or fluid. eccor ).

38. The apparatus according to claim 33, wherein, obtaining the purge gas flow rate (Q gas ) comprises: - directly or indirectly measuring the purge gas flow (Q gas ) ; or - Collect purge gas flow rate (Q) gas The specified value.

39. The apparatus according to claim 34, wherein, The saturated moisture content (C) at the gas outlet (19d) was obtained. saturation_out )include: - Obtain the blood inlet temperature or fluid inlet temperature (T) at the blood inlet or fluid inlet (19a) of the membrane gas exchanger (19). in ); -Based on the blood inlet temperature or fluid inlet temperature (T) in The saturated moisture content (C) at the gas outlet (19d) was calculated to determine the saturated moisture content. saturation_out ).

40. The apparatus according to claim 39, wherein, The blood inlet temperature or fluid inlet temperature (Tin) is measured or calculated, or is a constant default value.

41. The apparatus according to claim 35, wherein, The saturated moisture content (C) at the gas inlet (19c) is obtained. saturation_in )include: - Obtain the humidification temperature (T) hum ); -According to the humidification temperature (T) hum To calculate the saturated moisture content (C) at the gas inlet (19c). saturation_in ).

42. The apparatus of claim 41, wherein the humidification temperature (T) hum () is a measurement or calculation or a constant default value.

43. The apparatus according to claim 36, wherein, The relative humidity (RH) at the gas outlet (19d) is obtained. outlet )include: -Based on the type of the membrane gas exchanger (19) and the purge gas flow rate (Q) gas The relative humidity (RH) at the gas outlet (19d) is derived. outlet );or -Assuming the relative humidity (RH) at the gas outlet (19d) outlet ) equals 100%.

44. The apparatus according to claim 37, wherein, The relative humidity (RH) at the gas inlet (19c) is obtained. inlet )include: - If the purge gas is humidified, then assume the relative humidity (RH) at the gas inlet (19c) is... inlet ) equals 100%; or - If the purge gas is not humidified, then assume the relative humidity (RH) at the gas inlet (19c) is... inlet ) equals 0%.

45. The apparatus according to any one of claims 32 to 35, wherein, Compensating for at least partial water loss of the blood or fluid includes adding water to the extracorporeal blood circuit or the fluid circuit and / or reducing net fluid removal from the extracorporeal blood circuit.

46. ​​The apparatus according to claim 45, wherein, Water is added to the extracorporeal blood circuit or the fluid circuit to achieve equilibrium without the use of an effluent pump.

47. The apparatus according to any one of claims 32 to 35, wherein, The blood processing unit (2) includes a main chamber (3) and a secondary chamber (4) separated by a semipermeable membrane (5); wherein the extracorporeal blood circuit includes a blood extraction line (6) connected to the inlet (3a) of the main chamber (3) and a blood return line (7) connected to the outlet (3b) of the main chamber (3); wherein the fluid circuit includes an effluent fluid line (12) connected to the outlet (4b) of the secondary chamber (4) and an effluent pump (13) running on the effluent fluid line (12); wherein at least partially compensating for water loss (Q) of the blood or fluid. eccor This includes: adjusting the effluent pump (13).

48. The apparatus according to claim 47, wherein, The control unit is configured to adjust the effluent pump by reducing the pump speed of the effluent pump based on a calculated loss of moisture in the blood or fluid.

49. The apparatus according to any one of claims 32 to 35, comprising a water source (23, 23') directly or indirectly connected to the extracorporeal blood circuit via water lines (22, 22'), wherein, Water pumps (24, 24') operate on the water lines (22, 22'), wherein at least partially compensating for the water loss includes: infusing water into the extracorporeal blood circuit.

50. The apparatus according to claim 49, wherein, The water source (23, 23') is the source of the solution.

51. The apparatus according to claim 50, wherein, The source of the solution (23, 23') is a glucose solution or an electrolyte / infusion solution.

52. The apparatus according to claim 51, wherein, Water is infused into the extracorporeal blood circuit via the solution.

53. The apparatus according to claim 52, wherein, The control unit (10) is configured to calculate the water loss (Q) of blood or fluid. eccor To adjust the flow rate (Q) of water or solution infused into the extracorporeal blood circuit. water ).

54. The apparatus according to claim 49, wherein, The water line (22) is directly connected to the extracorporeal blood circuit at the connection point.

55. The apparatus according to claim 54, wherein, The connection point is located downstream of the blood pump (11).

56. The apparatus according to claim 49, wherein, The blood processing unit (2) includes a main chamber (3) and a secondary chamber (4) separated by a semipermeable membrane (5); wherein the extracorporeal blood circuit includes a blood extraction line (6) connected to the inlet (3a) of the main chamber (3) and a blood return line (7) connected to the outlet (3b) of the main chamber (3); wherein a dialysis fluid line (14) is connected to the inlet (4a) of the secondary chamber (4) and a dialysis fluid source, and at least one dialysis pump (15) is coupled to or configured to be coupled to a pump section of the dialysis fluid line (14); wherein the water line (22') terminates at the dialysis fluid line (14).

57. The apparatus according to claim 56, wherein, The water line (22') is connected to the dialysis fluid line (14) at the connection point between the dialysis pump (15) and the blood processing unit (2).

58. The apparatus according to claim 49, further comprising an infusion circuit, the infusion circuit comprising: One or more infusion lines (16) for displacement fluid connected to the extracorporeal blood circuit; and at least one infusion pump (18) coupled to or configured to be coupled to a pump section of the infusion lines (16); wherein the water line (22) terminates at at least one of the infusion lines (16).

59. The apparatus according to any one of claims 32 to 35, wherein, The blood processing unit (2) includes a main chamber (3) and a secondary chamber (4) separated by a semipermeable membrane (5), and in at least one configuration, the fluid circuit presents a closed loop connected to the secondary chamber (4).

60. The apparatus according to claim 32, wherein, Determining the water loss of the blood or fluid includes: - Obtain the purge gas flow rate (Q) in the gas side (202) of the membrane gas exchanger (19). gas ); - Obtain the blood inlet temperature or fluid inlet temperature (T) at the blood inlet or fluid inlet of the membrane gas exchanger (19). in ); - Obtain room temperature (T) room ); -At least according to the purge gas flow rate (Q) gas ) and the blood inlet temperature or fluid inlet temperature (T in To calculate the water loss (Q) of the blood or fluid. eccor ).

61. The apparatus according to claim 60, wherein, Calculate the water loss (Q) of the blood or fluid. eccor )include: -At least according to the purge gas flow rate (Q) gas The blood inlet temperature or fluid inlet temperature (T) in ) and the room temperature (T) room To calculate the water loss (Q) of the blood or fluid. eccor ).

62. The apparatus according to any one of claims 60 to 61, wherein, Determining the water loss of the blood or fluid includes: -Based on the blood inlet temperature or fluid inlet temperature (T) in To calculate the water volume (Q) at the gas outlet. gas-out ) -According to the stated room temperature (T) room To calculate the water volume (Q) at the gas inlet. gas-in ); -The loss of water from the blood or fluid (Q eccor The value is calculated as the difference between the water volume at the gas outlet and the water volume at the gas inlet.

63. The apparatus according to claim 62, wherein, The water loss (Q) of the blood or fluid is calculated using the following formula. eccor ): Q eccor =[Q gas-out x(α(T in ))]–[Q gas-in x(β(T room ))] in: Q gas-out x(α(T in The amount of water at the gas outlet (19d) is the amount of water. Q gas-in x(β(T room ) is the amount of water at the gas inlet (19c); T in It is the blood temperature at the blood inlet (19a); T room It is the stated room temperature; and Among them, the amount of water (Q) at the gas outlet gas-out The parameters related to the blood inlet temperature or the fluid inlet temperature are derived by calculation and are related to the water volume (Q) at the gas inlet. gas-in The parameters related to room temperature were derived through experimental testing.

64. The apparatus according to any one of claims 32 to 35, wherein, The membrane gas exchanger includes a gas-permeable membrane that separates the blood side or fluid side from the gas side and is a carbon dioxide (CO2) remover, wherein the gas exchanged is carbon dioxide (CO2) and is removed from the blood or fluid, and wherein the gas-permeable membrane includes a plurality of hollow fibers.

65. The apparatus according to any one of claims 32 to 35, wherein, A purge gas source is connected to the gas inlet to supply purge gas through the gas side of the membrane gas exchanger, wherein the purge gas is a dry gas or a humidifying gas.

66. The apparatus according to claim 65, wherein, The purging gas is dry air or humidified air, molecular oxygen, or a mixture of air and molecular oxygen.

67. The apparatus according to claim 65, wherein, The device for humidifying the purge gas is placed between the purge gas source and the gas inlet.

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