DEVICES FOR CALIBRATING A PUMP FOR BLOOD TREATMENT

Description

[0001] The present invention relates to a control device according to claim 1 for calibrating a pump for blood treatment. It further relates to a blood treatment device according to claim 12.

[0002] Extracorporeal blood therapy is a well-known procedure. In this process, blood is drawn from the patient and circulated extracorporeally, for example, through a blood filter. A blood pump is typically used for this purpose. Since the accuracy of the blood pump, as well as other pumps, can be critical, it is necessary to calibrate them, as disclosed, for example, in EP 3 034 106 A1, US 5,200,090, or EP 3 031 485 A1.

[0003] The actual pumping rate, especially with roller pumps, can deviate from the specified flow rate. The specified flow rate can be determined, for example, by the rotational speed of the pump rotor.

[0004] One object of the present invention is to provide a control device by means of which a method for calibrating a pump for blood treatment can be carried out.

[0005] Furthermore, a blood treatment device with which the procedure can be carried out should be specified.

[0006] The problem according to the invention is solved by a control device having the features of claim 1. It is further solved by a blood treatment device having the features of claim 12.

[0007] All the advantages achievable with the method disclosed herein can also be achieved without diminishing quality in certain embodiments of the invention using the devices according to the invention.

[0008] The present invention relates to a method for determining an actual pump rate (may be volume per time) and / or for calibrating a blood pump of a blood treatment device connected to an extracorporeal blood circulation.

[0009] The method comprises, as a first of several steps, providing a blood pump to a blood treatment device or establishing a signal connection to a blood pump. The blood pump is connected or connectable to at least one first fluid source and at least one first line of an extracorporeal blood circuit, which is connected downstream of the first source. This first source is preferably not a patient, and the fluid of the source is preferably not blood. Furthermore, the blood pump is connectable or connected to at least one first receiving device for receiving fluids from the first source, the receiving device being in fluid communication with the first line. The receiving device is arranged on or attached to a first weighing device such that the weight of the receiving device and / or the weight of its contents can be determined by means of the weighing device.

[0010] The procedure includes, as a further step, setting a value for a pump rate adjustable on the blood pump as the set pump rate, or transmitting such a value to the blood pump as the set pump rate.

[0011] In the next step, the blood pump is operated at the set pumping rate for a certain delivery period in such a way that fluid from the source is pumped into the receiving area as the actual volume through the first line, or fluid that is present in the first line and is displaced by fluid from the source.

[0012] In a further step included in the procedure, the actual volume pumped during a pumping period (a time interval) is determined by the first weighing device based on a change in the weight of the receiving device and / or its contents. The density of the pumped fluid can be taken into account. The actual volume is determined, for example, based on the weight of the actual pumped volume, or based on a change in the weight of the receiving device or its contents due to the pumped volume, or based on or derived from these methods, such as known relationships between the volume and weight of the pumped fluid.

[0013] The procedure includes, as a further step, determining a mathematical relationship between the actual volume and a target volume, which results from the delivery time and the set pump rate, and / or determining the actual pump rate from the actual volume and the target volume.

[0014] The control or regulating device according to the invention is suitable and provided and / or designed and / or configured for carrying out the method.

[0015] The present invention further relates to a blood treatment device. The blood treatment device according to the invention has or is connected to an extracorporeal blood circulation system. The blood treatment device further has or is connected to at least one blood pump (which serves to pump blood during blood treatment), which is connected to at least one first fluid source and to at least one first line which connects downstream to the first source. The blood treatment device further has or is connected to at least one receiving device for fluid from the first source, wherein the receiving device is in fluid communication with the first line, and to a first weighing device for receiving the fluid.

[0016] The blood treatment device according to the invention also includes or is connected to a control device, which is configured to set a value for a pump rate adjustable on the blood pump as a pump rate set by the user. Furthermore, the control device is configured to operate at least one blood pump at the set pump rate for a certain delivery time such that fluid from the source is delivered through the first line into the receiving area. The control device, which is connected to the blood treatment device, is also configured to determine the actual volume delivered during the delivery time and / or the actual pump rate using the first weighing device. It is also configured to determine a mathematical relationship between the actual volume and the target volume, which results from the delivery time and the set pump rate.

[0017] The blood treatment device according to the invention is designed and configured and / or equipped to carry out the procedure.

[0018] The control device according to the invention is suitable and provided and / or designed and / or configured for carrying out the method in conjunction with the equipment required for this purpose, for example as described herein.

[0019] Inventory embodiments may include some, several, or all of the following features in any combination, provided that this is not technically impossible to the person skilled in the art. Advantageous further developments of the present invention are also the subject of the dependent claims.

[0020] In all the following explanations, the use of the expression "may be" or "may have" etc. is to be understood as synonymous with "is preferably" or "has preferably" etc. and is intended to explain embodiments according to the invention.

[0021] Whenever numerical terms are used herein, a person skilled in the art understands them to indicate a lower numerical limit. Unless this leads to a contradiction apparent to a person skilled in the art, they will always interpret the terms "a" or "a" as meaning "at least one" or "at least one." This understanding is encompassed by the present invention, as is the interpretation that a numerical term such as "a" can alternatively be meant as "exactly one," wherever this is technically feasible to a person skilled in the art. Both are encompassed by the present invention and apply to all numerical terms used herein.

[0022] When an embodiment is mentioned herein, it represents an exemplary embodiment according to the invention.

[0023] In certain embodiments, the blood treatment device is a hemodialysis device, hemofiltration device or hemodiafiltration device, in particular a device for chronic renal replacement therapy or for continuous renal replacement therapy (CRRT).

[0024] In some embodiments, the blood treatment device includes a control or regulating device, preferably according to the invention. The control or regulating device can be programmed and / or configured to carry out the method in conjunction with other devices, in particular a blood treatment device.

[0025] In certain embodiments of the present invention, the extracorporeal blood circulation system is a tubing set. In each case, the extracorporeal blood circulation system is intended for the extracorporeal conveyance of a patient's blood, for example during hemodialysis, hemofiltration, hemodiafiltration, or the like.

[0026] In some embodiments of the invention, the extracorporeal blood circulation is designed, at least partially, as an integral and possibly inseparable component of a blood cassette, while in others it is not. Thus, a freely movable section of tubing of the extracorporeal blood circulation can continue integrally or in one piece onto or within the functional device, for example, a blood cassette, and vice versa.

[0027] In certain embodiments of the present invention, a blood cassette is a device used in blood treatment. Examples of blood cassettes include disposable or single-use blood cassettes.

[0028] Exemplary embodiments of a blood cassette are disclosed in particular in the applicant's application with publication number DE 10 2009 018 664 A1 entitled "External functional device, blood treatment device for receiving an external functional device according to the invention, and method", which was filed with the German Patent and Trade Mark Office on 23 April 2009, and in the applicant's application with publication number DE 10 2009 024 468 A1 with the same title, which was filed with the German Patent and Trade Mark Office on 10 June 2009.

[0029] In certain embodiments of the present invention, the arterial conduit section of the extracorporeal blood circulation is that conduit section into which the patient's blood leaving the patient's body for extracorporeal blood treatment flows and in which it is located before entering the blood treatment device, e.g. a dialyzer.

[0030] In certain embodiments of the present invention, the first section of the arterial conduit section is or comprises the arterial needle connection to the patient, e.g. the arterial needle connection in a double-needle dialysis procedure.

[0031] In some embodiments, the method includes a step that determines the ratio between the set pump rate and the actual pump rate. The actual pump rate is determined taking into account the actual volume and the pumping duration.

[0032] In some embodiments, a correction factor or calibration factor for the blood pump is determined during or by means of the process. This factor is determined, calculated, or calculated based on the ratio between the pump rate set on the blood pump and the actual pump rate, and / or based on the actual volume and the target volume.

[0033] According to the invention, generating equal pressure conditions before and after pumping (or pumping time) in the first line is considered a further step of the method. The term "after pumping" can describe a point in time before determining the actual volume and / or the actual pumping rate. In some embodiments, the method includes generating equal pressure conditions in the first line during the pumping time.

[0034] "Consistent pressure conditions during pumping" can mean, for example, that two, three, or more measurements taken during the pumping period yield the same results, or results that are considered identical (because they are due to measurement fluctuations, etc.). Alternatively, it can mean that the measured pressure does not change at least over a period of time during the pumping period, or over the entire pumping period.

[0035] In some embodiments, the extracorporeal blood circulation includes or is connected to a blood filter or dialyzer, which usually has a semi-permeable membrane.

[0036] The intake is in fluid contact with the first line.

[0037] In some embodiments, the intake is located downstream of the blood filter or dialyzer and through its membrane in fluid communication with the first line.

[0038] In some embodiments of the method, the dialyzer is connected to a dialysis fluid supply line and a dialysate line. An effluent pump may be arranged in the dialysate line. A check valve and / or an occluding pump is integrated into the dialysis fluid supply line. The check valve primarily serves to prevent unwanted flow in the opposite direction to the flow direction of the dialysis fluid supply line during intended use and / or away from the blood filter.

[0039] In some embodiments, the dialyzer is connected to an arterial patient line and a venous patient line in fluid communication, with a hose clamp arranged in or on the venous patient line. The method further includes closing the hose clamp on the venous patient line during the pumping time and / or the execution of the method.

[0040] In some embodiments of the method, the blood pump and an effluent pump operate at the same pumping rate during the pumping period.

[0041] The effluent pump can be a pump for removing used dialysate from the blood filter or a filtrate pump.

[0042] In some embodiments, the method includes in one step regulating the pump to maintain constant pressure in the first line during the pumping period.

[0043] In certain embodiments, the effluent pump is rotated to generate equal pressure conditions, in particular by the control or regulating device, especially pressure-controlled.

[0044] In some embodiments, the first fluid is a saline solution, a dialysis fluid or a substitute, in particular a priming fluid.

[0045] In some embodiments, the method includes the step of providing the blood treatment device as a hemodialysis device, hemofiltration device or hemodiafiltration device, in particular as a device for chronic renal replacement therapy or for continuous renal replacement therapy (CRRT).

[0046] In some embodiments of the present invention, the venous section of the extracorporeal blood circulation is that section from which the extracorporeally treated patient blood flows to or back into the patient's body after its treatment in a blood treatment device, for example a dialyzer.

[0047] In some embodiments according to the invention, the control device is designed as a control device.

[0048] The blood treatment device according to the invention has, in certain embodiments according to the invention, at least one control device according to the invention.

[0049] Preferably, the procedure does not take place during patient treatment. Preferably, the procedure takes place without a patient being connected to the blood treatment device. Preferably, the procedure takes place without blood being drawn from the patient and / or preferably without blood being returned to the patient.

[0050] Methods for converting a set value for a pump rate adjustable on the blood pump into a set pump rate include, for example, methods that are based on the number of pump movements of the blood pumps, e.g., the number of revolutions of its rotor.

[0051] Some or all embodiments of the invention may have one, several or all of the advantages mentioned above and / or below.

[0052] An advantage achievable with certain embodiments of the present invention is that the blood flow rate can be precisely determined by the blood pump. This can be particularly important for patient treatment where medications are dosed depending on the blood flow rate, for example, in regional anticoagulation, where citrate is added to the flowing blood in specific ratios depending on the blood flow. Precise knowledge of the blood flow rate is especially advantageous in these cases. The same applies to situations where only low blood flows are generated by the blood pump, such as in pediatric applications. Here, it is particularly important to know the blood flow rate accurately.

[0053] Another advantage is that it eliminates the need for flow sensors to determine the precise blood flow. Knowing the exact blood pumping rate, the precise blood flow is known—at least with sufficient accuracy.

[0054] A further advantage may be that in some embodiments of the invention, weighing devices that are already available are used to weigh the sample in order to determine the actual volume, for example because they are used for balancing during blood treatment carried out after completion within the framework of the inventive method, in particular in continuous renal replacement therapy (CRRT).

[0055] A particular advantage of this approach is that the blood pump can be automatically calibrated and / or the correction factor automatically determined. This eliminates the need to reposition or rearrange fluid containers, for example, by placing them on scales, or to provide separate fluid containers specifically for calibration, etc. In certain configurations, this can save time and effort. It is advantageous to use existing setups that can be used without modification in subsequent blood treatments.

[0056] The present invention is described below by way of example only, with reference to the accompanying figures. In these figures, the same reference numerals denote identical or the same components. The following applies: Fig. 1 Figure 1 shows a simplified representation of a blood treatment device according to the invention with an extracorporeal blood circulation in a first embodiment; Fig. 2 Figure 1 shows a simplified representation of a blood treatment device according to the invention with an extracorporeal blood circulation in a second embodiment; and Fig. 3 Figure 1 shows a simplified representation of a blood treatment device according to the invention with an extracorporeal blood circulation in a third embodiment.

[0057] Fig. 1 Figure 1 shows a simplified representation of a blood treatment device 100 according to the invention, connected to an extracorporeal blood circulation 300, during the execution of the method described herein. Fig. 1 This demonstrates the basic principle of the present invention.

[0058] The extracorporeal blood circulation 300 has a first conduit 301, here in the form of an arterial conduit section.

[0059] The first line 301 is in fluid connection with a blood treatment device, here exemplified by a blood filter 303 or dialyzer. The blood filter 303 has a dialysis fluid chamber 303a and a blood chamber 303b, which are separated from each other by a mostly semi-permeable membrane 303c.

[0060] The extracorporeal blood circulation 300 also includes at least one second line 305, here in the form of a venous line segment. Both the first line 301 and the second line 305 can serve to connect to the vascular system of the patient (not shown).

[0061] The in Fig. 1 The blood treatment device 100, represented only by some of its components, by means of which the procedure described here is carried out, includes a blood pump 101. During the treatment of the patient, the blood pump 101 pumps blood through sections of the extracorporeal blood circulation 300 and towards the blood filter 303, as shown by the small arrowheads, which generally indicate the direction of flow in the figures.

[0062] To calibrate the blood pump 101, fluid is pumped from a source 200 along the first line 301 towards the receiving point 400 using the blood pump 101, which can optionally be designed as a roller pump or as an otherwise occluding pump.

[0063] Source 200 can be, for example, a bag or a container. The same applies to inlet 400. Source 200 can also be a fluid line from which online and / or continuously generated or mixed fluid is supplied, e.g., a hydraulic outlet or port of the blood treatment device.

[0064] The receptacle 400 is connected to a first weighing device 141 for weighing its own weight or the fluid it contains, or for determining a change in weight. For example, the receptacle 400 can lie as a collection bag on a weighing surface of the first weighing device 141 or hang from a weighing hook.

[0065] If the blood pump 101 pumps for a predetermined or determinable period, namely the pumping duration T, then, based on the pumping rate P1 set on the blood pump 101 – either by the user or by a test program – and the pumping duration T, the volume of fluid that would have been pumped if the blood pump 101 had actually pumped at the set pumping rate P1 can be determined using the simple relationship P1*T = VS. This volume is referred to here as the target volume VS.

[0066] In practice, the actual delivery volume, referred to herein as actual volume VI, may differ from the target volume.

[0067] The actual volume VI is found in the recording 400 after the conveying time T has elapsed. It can be determined by weight measurement, which is carried out here using the first weighing device 141 as an example; its weight corresponds to the increase in the weight of the recording 400 between a measurement taken before the start of the conveying time T and a measurement taken after the conveying time T.

[0068] A comparison of the measured actual volume VI with the calculated target volume VS can be used to calculate a correction factor or a calibration value of the set pump rate or the blood pump 101.

[0069] A first to Fig. 2 described and shown there control or regulating device 150 (see Fig. 2 The device can be configured to execute the above procedure. Optionally, execution can be automatic. Optionally, execution can start automatically, for example, as part of a test function, a self-check when the blood treatment device is started, during or after a priming process, etc.

[0070] Fig. 2 Figure 1 shows a simplified representation of a blood treatment device 100 according to the invention with an extracorporeal blood circulation 300 in a second embodiment.

[0071] In addition to the aforementioned blood pump 101, the one in Fig. 2 The arrangement shown also optionally includes a number of further, each optional, pumps, namely pump 111 for substitute, pump 121 for dialysis fluid, and pump 131 for dialysate and / or effluent.

[0072] The pump 121 is designed to draw dialysis fluid from a source Q4, for example a bag, and supply it via an optional bag heater and a dialysis fluid supply line 104 to a bag H2.

[0073] The dialysate supplied in this way exits again via a dialysate line 102, supported by the pump 131, and can be discarded.

[0074] An optional arterial sensor PA1 is provided for the power supply of the blood pump 101. During patient treatment, it measures the pressure in the arterial line.

[0075] Downstream of blood pump 101, but upstream of blood filter 303 and, if provided, a heparin injection point 25, a further, optional pressure sensor PA2 is provided. It measures the pressure upstream of blood filter 303 ( p rä- H amo f filter").

[0076] A further pressure sensor can be provided as PD1 downstream of the blood filter 303, but preferably upstream of the pump 131 in the dialysate line 102 to measure a filtrate pressure downstream of the blood filter 303.

[0077] Blood leaving the blood filter 303 flows through an optional venous blood chamber 29, which may have an optionally lockable venting device 31 and may be in fluid communication with a further pressure sensor PV1.

[0078] In the example of the Fig. 2 Source Q4 and an optional additional source Q4', from which substitute is drawn by pump 111 via a further bag heater with bag H3, as well as the collected or discarded dialysate, are optionally subject to balancing. For the purpose of balancing, in addition to the Fig. 1 The first known weighing device 141 may optionally be supplemented by two further scales or weighing devices 142 and 143.

[0079] The balancing method shown here as an example corresponds to a gravimetric balancing method. However, the present invention also encompasses any other balancing method, for example, using balancing chambers.

[0080] The in Fig. 2 The exemplary arrangement shown includes a control or regulating device 150. It can be connected, via wired or wireless signal link, to any of the components mentioned herein—in any case, or in particular, to the blood pump 101—for the control or regulation of the blood treatment device 100. It is optionally configured to perform the procedure described herein.

[0081] The first line 301 is optionally connected to a hose clamp 302 for locking or closing the line 301. The second line 305 is optionally connected to a hose clamp 306 for locking or closing the line 305.

[0082] Although the design of the Fig. 2 shown with a recording 400 for fluid, the weight of which is determined by the first weighing device 141, whereby the recording 400 can be assigned to the blood side due to its fluid connection with the blood circulation, here downstream of the blood filter 303.

[0083] However, the sample can alternatively be positioned on the hydraulic side or the filtrate side (i.e., not on the blood side but, for example, in the area of ​​components 102 and 131). The sample can then be weighed using the third weighing device 143, as indicated by reference numeral 400'.

[0084] Fig. 3 Figure 1 shows a simplified representation of a blood treatment device 100 according to the invention with an extracorporeal blood circulation 300 in a third embodiment.

[0085] The presentation of Fig. 3 differs from that of the Fig. 2 already by the fact that a number of components which are in Fig. 2 shown for the sake of clarity are in Fig. 3 They are not shown again. However, they can optionally be present here as well.

[0086] The in Fig. 3 The embodiment shown differs from the one in Fig. 2 This is demonstrated, at least in part, by the fact that an optional check valve 104a is arranged in the dialysis fluid supply line 104. The check valve 104a opens at a sufficiently high pressure to allow flow through the dialysis fluid supply line 104 towards the blood filter 303. However, the check valve 104a prevents flow in the opposite direction through the dialysis fluid supply line 104.

[0087] In the embodiment of the Fig. 3 The blood pump 101 pumps fluid from source 200 into the blood filter 303. Since the hose clamp 306 of the second line 305 is closed, the pumped fluid passes through the membrane 303c from the blood chamber 303b into the dialysis fluid chamber 303a. The check valve 104a—or another occlusive device, such as a roller pump instead of or in addition to the check valve—prevents the fluid that has entered the dialysis fluid chamber 303a from leaving it by any route other than through line 102. The pumping of the fluid along the path described above is ensured by the pumping action of the pump 131, the effluent pump, which is inserted into the dialysate line 102. Finally, the fluid is directed into the receiving chamber 400. Its change in weight can be determined by means of the third weighing device 143. From this, the actual volume VI, which the blood pump 101 pumped during the pumping time T, can be derived.

[0088] The following features, although not shown in the figures, can again be provided purely optionally and in any combination in each embodiment of the invention: The first line 301 can have an arterial septum, optionally in the form of an addition device.

[0089] The first line 301 and / or the second line 305 may have an air bubble detector / optical sensor.

[0090] The circulatory system can be at least partially part of a blood cassette, which has a hard part, wholly or partially covered by a film, or connected to it. Bezugszeichenliste

[0091] 25 Heparin injection point (optional) 29 Venous blood chamber (optional) 31 Venting device 100 Blood treatment device 101 Blood pump 102 Dialysate line 104 Dialysis fluid line 104a Check valve 111 Substitute pump 121 Dialysis fluid pump 131 Dialysate and / or effluent pump 141 First weighing device 142 Second weighing device 143 Third weighing device 150 Control or regulating device 200 Fluid source 300 Extracorporeal blood circuit 301 First line (arterial line section) 302 Hose clamp 303 Blood filter or dialyzer 303a Dialysis fluid chamber 303b Blood chamber 303c Semi-permeable membrane 305 Second line (venous line section) 306 Hose clamp 400 Fluid intake 400 Fluid intake H2 Bag heater with bag (dialysis fluid) H3 Bag heater with bag (substitute) PA1,PA2 arterial pressure sensor (optional) PD1 pressure sensor for measuring filter pressure PV1 pressure sensor (optional) P1 set pump rate Q4 source with dialysis fluid Q4' source (substitute), optional T pumping time VII actual volume VS target volume

Claims

1. A control or regulating device (150), suitable and provided and / or designed and / or configured to carry out a method for determining an actual pump rate and / or for calibrating a blood pump (101) of a blood treatment apparatus (100) which is connected to an extracorporeal blood circuit (300) with a dialyzer (303) having a semi-permeable membrane (303c), comprising the steps of: - establishing a signal connection to the blood pump (101) which comprises or can be connected or is connected to: - at least one first source (200) for a fluid; - at least one first line (301) of an extracorporeal blood circuit (300), which connects downstream to the first source (200); - at least one receptacle (400) for receiving fluid from the first source (200), the receptacle (400) being in fluid communication with the first line (301); - wherein the receptacle (400) is arranged on or at a first weighing device (141) such that the weight of the receptacle (400) and / or its content can be determined by means of the weighing device (141); wherein the method comprises the further steps of: - setting a value for a pump rate adjustable at the blood pump (101) as a set pump rate (P1), or transmitting such a value to the blood pump (101) as a set pump rate (P1); - operating the blood pump (101) at the set pump rate (P1) during a pumping time (T) such that fluid from the first source (200) is delivered as an actual volume (VI) through the first line (301) into the receptacle (400); - determining an actual volume (VI) delivered during the pumping time (T) by means of the first weighing device (141) based on a change in the weight of the receptacle (400) or its content; - determining a mathematical relationship between the actual volume (VI) and a target volume (VS) resulting from the pumping time (T) and the set pump rate (P1); - generating equal pressure conditions before and after the pumping time (T) in the first line (301).

2. The control or regulating device (150) according to claim 1, wherein the method comprises the step of: - determining a ratio between the set pump rate (P1) and an actual pump rate, the actual pump rate being determined by considering the actual volume (VI) and the pumping time (T).

3. The control or regulating device (150) according to claim 1 or 2, wherein the method comprises the step of: - determining a correction factor or calibration factor for the blood pump (101) based on the ratio between the pump rate (P1) set at the blood pump (101) and the actual pump rate and / or based on the actual volume (VI) and the target volume (VS).

4. The control or regulating device (150) according to any one of the preceding claims, wherein the method comprises the step of: - generating equal pressure conditions during the pumping time (T) in the first line (301).

5. The control or regulating device (150) according to any one of the preceding claims, wherein the receptacle (400) is in fluid communication with the first line (301) downstream of the dialyzer (303).

6. The control or regulating device (150) according to any one of the preceding claims, wherein the receptacle (400) is in fluid communication with the first line (301) downstream of the dialyzer (303) and through the dialyzer' s membrane (303c),7. The control or regulating device (150) according to any one of the preceding claims, wherein the dialyzer (303) is connected to a dialysis fluid supply line (104) and a dialysate line (102), wherein a non-return valve (104a) and / or an occluding pump is / are integrated into the dialysis fluid supply line (104) to prevent an undesired flow, in particular in the direction opposite to the flow direction of the dialysis fluid supply line (104) and / or in the direction away from the dialyzer (303).

8. The control or regulating device (150) according to any one of the preceding claims, wherein the dialyzer (303) is in fluid communication with an arterial patient line (301) and with a venous patient line (305), wherein a tube clamp (306) is arranged in or on the venous patient line (305), wherein the method further comprises closing the tube clamp (306) on the venous patient line (305) during the pumping time (T).

9. The control or regulating device (150) according to any one of the preceding claims, wherein the blood pump (101) and an effluent pump (131) deliver at the same pump rate during the pumping time (T).

10. The control or regulating device (150) according to claim 10, wherein, to generate equal pressure conditions, the effluent pump (131) is rotated by the control or regulating device (150), in particular in a pressure-controlled manner.

11. The control or regulating device (150) according to any one of the preceding claims, with the step of: - providing the blood treatment apparatus (100) as a hemodialysis apparatus, hemofiltration apparatus or hemodiafiltration apparatus, in particular designed as an apparatus for chronic renal replacement therapy or for continuous renal replacement therapy (CRRT).

12. A blood treatment apparatus (100) comprising or connected to an extracorporeal blood circuit (300), wherein the blood treatment apparatus (100) further comprises or is connected to: - a blood pump (101) which is connectable to or connected to: - at least one first source (200) for a fluid; - at least one first line (301) which connects downstream to the first source (200); - at least one receptacle (400) for receiving fluid from the first source (200), the receptacle (400) being in fluid communication with the first line (301); - a first weighing device (141) for the receptacle (400); a control or regulating device (150) according to any one of the claims 1-11 and / or configurated to: - set a value for a pump rate adjustable at the blood pump (101) as a set pump rate (P1) by the user or automatically by the control or regulating device (150); - operate at least one blood pump (101) at the set pump rate (P1) during a pumping time (T) such that fluid from the source (200) is delivered through the first line (301) into the receptacle (400); - determine the actual volume (VI) delivered during the pumping time (T) and / or an actual pump rate by means of the first weighing device (141); - determine a mathematical relationship between the actual volume (VI) and a target volume (VS) resulting from the pumping time (T) and the set pump rate (P1); - generate equal pressure conditions before and after the pumping time (T) in the first line (301).

13. The blood treatment apparatus according to claim 12, designed as a hemodialysis apparatus, hemofiltration apparatus or hemodiafiltration apparatus, in particular as an apparatus for chronic renal replacement therapy or for continuous renal replacement therapy (CRRT).