System for supplying medical fluids for renal replacement therapy and method of operating such a system

Abstract

A system comprising a first device (10) and a second device (30), the first and second devices being connected to establish a fluid path (21) between a pump (15) in the first device (10) and a container (38) in the second device (30) through a valve (32) in the second device (30). A control unit (31) in the second device (30) selectively operates the valve (32) to open the fluid path (21). The second device (30) is configured to supply medical fluid for renal replacement therapy by using a first fluid (Fl) received from the first device on the fluid path (21). A control unit (11) in the first device (10) directly or indirectly measures fluid pressure in the fluid path (21) and intermittently operates to activate the pump (15) to pump the first fluid (Fl) into the fluid path (21) and deactivate the pump (15) when the fluid pressure in the fluid path (21) indicates that the valve (32) is closed. The first device (30) is thereby operable to replenish the container (38) without synchronisation with the second device (30).

Description

Technical Field

[0001] This disclosure relates to the field of renal replacement therapy, and more particularly to the supply of medical fluids for such treatment. Background Technology

[0002] Renal replacement therapy (RRT) is a treatment that replaces the normal blood-filtration function of the kidneys. This therapy is used when the kidneys are not functioning properly, a condition known as kidney failure, and includes both acute kidney injury and chronic kidney disease. RRT involves removing solutes from the blood of patients with kidney failure, for example, through dialysis (hemodialysis (HD) or peritoneal dialysis (PD), blood filtration, or hemodialysis filtration. Depending on the therapy, RRT can be performed manually or using a machine.

[0003] In RRT, one or more medical fluids of a specific composition are used for blood therapy. These medical fluids include so-called dialysis fluids and replacement fluids.

[0004] Medical fluids used in RRT can be generated by mixing one or more fluids (e.g., one or more concentrates) with water. In some facilities, a separate water preparation unit is arranged to receive and treat tap water to produce water of sufficient purity and quality, for example, through reverse osmosis (RO). The water preparation unit is arranged to pump purified water to a fluid generation unit as needed, which mixes the purified water with the concentrate. The fluid generation unit may or may not be integrated into the dialysis machine. Dedicated communication interfaces are provided on the water preparation unit and the fluid generation unit to enable the devices to synchronize their operation, for example, by exchanging synchronization signals. This communication interface increases the cost of the water preparation unit and the fluid generation unit and reduces interoperability between different manufacturers and between older and newer equipment.

[0005] US2019 / 0262522 addresses this problem concerning a fluid generation apparatus configured to generate dialysis fluid for PD using purified water from a separate water source. US2019 / 0262522 proposes providing corresponding pumps for the water source and the fluid generation apparatus, and installing a water line between the water source and the fluid generation apparatus to establish fluid communication between the pumps. The fluid generation apparatus operates its pumps independently of the pumps in the water source. In one of the many proposed embodiments, the water source is equipped with automatic demand control by being configured to continuously monitor the pressure in the water line and control its pumps to supply purified water based on the monitored pressure. A similar solution is proposed in US2010 / 0018923. One disadvantage of these proposals is that the water source needs to be actively controlled at all times during the operation of the fluid generation apparatus. This leads to increased power consumption and may also cause significant mechanical wear on the pumps in both the water source and the fluid generation apparatus over time.

[0006] The aforementioned technical challenges also apply to transferring medical fluids from the fluid generation device to an RRT machine that is physically separated from the fluid generation device. Summary of the Invention

[0007] The aim is to at least partially overcome one or more limitations of the existing technology.

[0008] Another objective is to provide a system for supplying medical fluids for use in RRT while reducing the need for synchronization between a first device for supplying the first fluid and a second device for supplying the medical fluids using the first fluid.

[0009] Another objective is to reduce the power consumption of such systems used to supply medical fluids and / or improve their robustness.

[0010] One or more of these objectives, as well as other objectives that may be apparent from the following description, are achieved, at least in part, by the system for generating medical fluids according to the independent claims, the system and method for treating used medical fluids, and the embodiments thereof as defined in the dependent claims.

[0011] A first aspect is a system for supplying a medical fluid for renal replacement therapy. The system includes a first device configured to provide a first fluid. The first device includes a fluid pump and a first control unit. The system also includes a second device configured to supply the medical fluid using the first fluid. The second device includes a container, a control valve, and a second control unit. The first and second devices are connected to establish a fluid path between the fluid pump in the first device and the container in the second device via the control valve. The second control unit is configured to selectively operate the control valve to open the fluid path. The first control unit is connected to a sensor device configured to measure a parameter indicating the fluid pressure in the fluid path. The first control unit is configured to intermittently and independently of the parameter during operation of the second device to pump the first fluid into the fluid path, and to deactivate the fluid pump when the parameter indicates that the control valve is closed.

[0012] The second aspect is a method performed by a first device in fluid communication with a second device, the second device supplying a medical fluid for renal replacement therapy using a first fluid. The method includes: while operating the second device to supply the medical fluid, intermittently activating a fluid pump in the first device to pump the first fluid along a fluid path extending between the fluid pump in the first device and a container in the second device via a control valve in the second device; obtaining a measurement from a sensor device of a parameter indicating the fluid pressure in the fluid path; and deactivating the fluid pump when the parameter indicates that the control valve is closed.

[0013] The first and second aspects employ a trial-and-error method of operating the first device, enabling it to operate independently of the second device while still ensuring that the container in the second device is properly and timely replenished with the first fluid from the first device. Furthermore, by intermittently activating the fluid pump in the first device, the pump's lifespan can be extended and its power consumption reduced. Additionally, by incorporating a control valve in the second device to selectively open and close the fluid path between the first and second devices, the pump used to draw fluid from the first device can be eliminated in the second device. This reduces costs, saves power, and increases the system's robustness.

[0014] The first and second aspects apply to a second device configured to generate a medical fluid by processing a first fluid from a first device (e.g., by adding one or more compounds to the first fluid), and configured to supply the medical fluid for use in RRT. The first and second aspects also apply to a first device that supplies the medical fluid to the second device, configured to supply the medical fluid for use in RRT. Here, the second device does not need to process the first fluid to generate the medical fluid, because the first fluid already constitutes a medical fluid.

[0015] A third aspect is a system for processing used medical fluids from renal replacement therapy. The system includes a first device comprising a fluid pump and a first control unit. The system also includes a second device comprising a container arranged to collect the used medical fluid, a control valve, and a second control unit. The first and second devices are connected to establish a fluid path between the fluid pump in the first device and the container in the second device via the control valve. The second control unit is configured to selectively operate the control valve to open the fluid path. The first control unit is connected to a sensor device configured to measure a parameter indicating the fluid pressure in the fluid path. The first control unit is configured to intermittently and independently of this parameter to activate the fluid pump to draw used medical fluid from the fluid path, and to deactivate the fluid pump when the parameter indicates that the control valve is closed.

[0016] The fourth aspect is a method performed by a first device in fluid communication with a second device, the second device providing used medical fluid from renal replacement therapy. The method includes: intermittently activating a fluid pump in the first device to draw used medical fluid along a fluid path extending between the fluid pump in the first device and the container in the second device via a control valve in the second device; obtaining a measurement of a parameter indicating the fluid pressure in the fluid path from a sensor device; and deactivating the fluid pump when the parameter indicates that the control valve is closed.

[0017] The third and fourth aspects share technical advantages with the first and second aspects, such as enabling the first device to operate independently of the second device, and extending the life of the fluid pump and reducing power consumption through intermittent starting of the fluid pump.

[0018] The fifth aspect is a computer-readable medium comprising program instructions that, when executed by a processor, cause the processor to perform the methods of the second or fourth aspect.

[0019] Other objects, aspects, advantages, features, and embodiments may become apparent from the following detailed description, from the appended claims, and from the accompanying drawings. Attached Figure Description

[0020] Figures 1A-1B These are schematic diagrams of example systems according to the first and second embodiments, and Figure 1C yes Figures 1A-1B A schematic diagram of the control unit in the system.

[0021] Figure 2A It is control Figures 1A-1B A flowchart of an example method for the first device in the system. Figures 2B-2C It is control Figures 1A-1B A flowchart of an example method for the second device in the system. Figure 2D It is installation and startup. Figures 1A-1B A flowchart of an example method in the system. Figures 2E-2F It is a timing diagram based on the example of fluid transfer attempt through the first device and fluid entry through the second device.

[0022] Figures 3A-3B These are control Figures 1A-1B A flowchart of an example method for supplying a first fluid to a second device and receiving used medical fluid from the second device in a system. Detailed Implementation

[0023] Embodiments will now be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, of the embodiments. In fact, the subject matter of this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure may satisfy applicable legal requirements. The same reference numerals throughout refer to the same elements.

[0024] Furthermore, it should be understood that, where possible, any advantages, features, functions, apparatus and / or operational aspects of any embodiment described and / or contemplated herein may be included in any other embodiment described and / or contemplated herein, and / or vice versa. Additionally, where possible, unless expressly stated otherwise, any term expressed in the singular form herein is intended to also include the plural form and / or vice versa. As used herein, “at least one” shall mean “one or more”, and these expressions are intended to be interchangeable. Thus, the terms “a” and / or “an” shall mean “at least one” or “one or more”, even though the expressions “one or more” or “at least one” are used herein. As used herein, unless the context requires otherwise due to explicit language or necessary meaning, the word “comprising” or variations such as “including” or “containing” are used in an inclusive sense, i.e., specifying the presence of the stated feature but not excluding the presence or addition of other features in various embodiments.

[0025] Furthermore, it should be understood that although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the terms “plural,” “multiple,” and “a plurality of” are intended to imply the provision of two or more elements. The term “and / or” includes any and all combinations of one or more of the associated listed elements.

[0026] For the sake of brevity and / or clarity, well-known functions or structures may not be described in detail. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0027] The embodiments relate to a system for supplying medical fluids for use in renal replacement therapy (RRT). The system includes a first device and a second device. The first device is configured to supply a first fluid to the second device via a fluid path extending between the first and second devices. The second device is configured to supply medical fluids for use in RRT based on the first fluid. The second device may be configured to perform RRT using the medical fluid, or may not be configured to perform RRT using the medical fluid. In other words, the second device may be an RRT machine, such as a dialysis machine. The embodiments described herein assume that the second device includes a container arranged to receive the first fluid entering from the first device in the fluid path, and that the second device gradually consumes the first fluid in the container as it supplies medical fluids for use in RRT. As the first fluid in the container is consumed, the second device needs to replenish the container by receiving the first fluid in the fluid path. The embodiments described herein also assume that the container in the second device is not continuously replenished, but rather that the inlet valve is selectively opened by the second device, for example, the first fluid only intermittently entering the container whenever the amount of the first fluid in the container reaches a predetermined minimum.

[0028] The embodiments described below enable the first device to operate independently of the second device, while still ensuring that the containers in the second device are replenished appropriately and in a timely manner.

[0029] In some embodiments, this technical effect is achieved by providing a sensor device to the first device and by appropriately configuring the control unit of the first device to operate based on fluid pressure measured by the sensor device, which is configured to directly or indirectly measure the fluid pressure in the fluid path between the first and second devices. Specifically, the control unit is configured to intermittently activate a fluid pump (“supply pump”) in the first device during operation of the second device to pump first fluid into the fluid path, and to deactivate the fluid pump when the fluid pressure in the fluid path indicates that the inlet valve of the second device is closed. In these embodiments, the first device thus applies a trial-and-error (TAE) method by repeatedly attempting to push the first fluid into the container of the second device along the fluid path. These attempts are made independently of the fluid pressure in the fluid path, for example, according to a predefined schedule. Assuming the first fluid is an incompressible liquid, if the inlet valve on the second device closes in such an attempt, the fluid pressure in the fluid path will increase rapidly. The increase in fluid pressure is detected by the first device, thereby terminating the attempt. If the inlet valve on the second device opens in this manner, the first device will continue pumping the first fluid into the container of the second device according to a predefined setting, or until the second device closes the inlet valve. The TAE method allows the first device to operate independently of the second device while ensuring that the container in the second device can be replenished with the first fluid from the first device in a timely manner. Simultaneously, power consumption is limited through intermittent starting. Furthermore, at least for some types of fluid pumps, intermittent starting limits wear compared to continuous starting.

[0030] As noted, fluid transfer attempts are triggered independently of the fluid pressure in the fluid path between the first and second devices. In some embodiments, the time interval between fluid transfer attempts through the first device can be set relative to the expected time difference between replenishments of the container in the second device (“replenishment interval”) and / or the expected time from opening the inlet valve until the container is completely depleted (“depletion time”). For example, the second device can be designed to have a maximum (maximum possible) supply rate of medical fluid. The maximum supply rate of medical fluid corresponds to the maximum consumption rate of the first fluid in the container, and therefore corresponds to the minimum (minimum possible) replenishment interval. Similarly, the maximum supply rate corresponds to the minimum depletion time, which is given by dividing the amount of the first fluid remaining in the container when the inlet valve is open by the maximum consumption rate. Reference is made below. Figures 2E-2F An example is given of a standard for setting the time interval between fluid transfer attempts.

[0031] The TEA method can be applied in a similar manner when the first device is arranged to receive fluid (“second fluid”) from the second device in the second fluid path. By analogy with the foregoing embodiments, assume that the second device includes a container for collecting the second fluid and an outlet valve that opens intermittently to establish fluid communication between the container and the second fluid path. To implement the TEA method, the first device has a sensor device configured to directly or indirectly measure the fluid pressure in the second fluid path, and a control unit of the first device is configured to operate based on this fluid pressure. Specifically, in some embodiments, the control unit is configured to intermittently activate a fluid pump (“discharge pump”) in the first device during operation of the second device to draw the second fluid into the second fluid path, and deactivate the fluid pump when the fluid pressure in the second fluid path indicates that the outlet valve of the second device is closed. Thus, the first device repeatedly attempts to draw the second fluid from the second device in the second fluid path. These attempts are made independently of the fluid pressure in the second fluid path, for example, according to a predefined schedule. In some embodiments, the second fluid is used medical fluid, which is generated when the aforementioned medical fluid is used for RRT. The first device may be configured to direct incoming used medical fluid to an outlet or collect the used medical fluid in a container associated with the first device. In another alternative, the first device may be configured to generate (“regenerate”) medical fluid from the used medical fluid.

[0032] The embodiments are applicable to any type of RRT, including but not limited to hemodialysis, hemofiltration, hemodialysis filtration and peritoneal dialysis.

[0033] In some embodiments, the second device is a dialysis machine for hemodialysis, hemofiltration, or hemodialysis filtration. Such a dialysis machine can be specifically used to treat patients with acute kidney injury (AKI), commonly referred to as “acute dialysis.” AKI treatment via hemodialysis is typically performed continuously via so-called continuous renal replacement therapy (CRRT). Dialysis machines for acute dialysis typically include a scale, on which a container or “fluid bag” is releasably arranged. Operation of the dialysis machine is controlled based on the weight of the fluid bag, as indicated by the scale reading. Typically, at least one of the fluid bags is arranged to contain dialysis fluid used in dialysis treatment, and at least one of the fluid bags is arranged to receive used dialysis fluid. As is well known to those skilled in the art, dialysis treatment involves the extraction of excess fluid from a patient, commonly referred to as “ultrafiltrate.” The ultrafiltrate is included in the used dialysis fluid. The amount and rate of ultrafiltrate extracted from the patient are important therapeutic parameters during dialysis. During operation, the dialysis machine calculates and monitors these therapeutic parameters based on the scale reading, which represents the weight of the fluid bag.

[0034] Traditionally, dialysis fluid for acute dialysis is supplied in pre-filled fluid bags suspended from one or more scales on the dialysis machine. This places a burden on caregivers, who need to repeatedly replace empty fluid bags with new pre-filled ones. An alternative is to generate dialysis fluid on-site.

[0035] In one embodiment, the dialysis machine is arranged to receive dialysis fluid from a separate fluid preparation device, which can be configured to prepare the dialysis fluid from tap water or purified water. Therefore, an empty fluid bag on the scale of an existing dialysis machine used for acute dialysis can be connected to receive dialysis fluid from the fluid preparation device. During operation of the dialysis machine, this fluid bag may need to be replenished or refilled with dialysis fluid. However, the refilling process of the fluid bag may affect the operation of the dialysis machine and should therefore be performed infrequently and for limited periods of time. Referring to the foregoing discussion of the first and second devices, it is understood that the first device can be a fluid preparation device and the second device can be a dialysis machine. (See below for further details.) Figure 1B Describe the corresponding implementation example.

[0036] In another embodiment, the dialysis machine is capable of generating dialysis fluid from purified water, for example, by mixing one or more concentrates or substances with the purified water. The purified water can be received from a separate water purification unit, which can be configured to treat tap water into purified water. In an example of a dialysis machine for acute dialysis, purified water can be received in a fluid bag on the scale of the dialysis machine, and mixing can be performed in and / or downstream of this fluid bag. As with the aforementioned embodiments, it may be desirable to perform fluid bag refilling infrequently and within a limited timeframe. Therefore, the first device can be a water preparation device, and the second device can be a dialysis machine. (Refer to below) Figure 1A Describe the corresponding implementation example.

[0037] Figure 1AA treatment system 1 is schematically shown, comprising a water preparation device (WPD) 10 (“first device”) and an RRT machine 30 (“second device”), connected for fluid communication. A control unit 11 is arranged to control the operation of the WPD 10, and a control unit 31 is arranged to control the operation of the RRT machine 30. The WPD 10 includes a water treatment unit 12, a connector 13 for connecting the WPD 10 to a tap water source 40, an inlet valve 14, a supply pump 15, a first pressure sensor 16, a discharge pump 17, and a second pressure sensor 18. The control unit 11 is operable to open the inlet valve 14 to allow tap water F0 from the source 40 into the water treatment unit 12, which is configured to treat the tap water into purified water suitable for dialysis. The water treatment unit 12 can be of conventional construction and can perform one or more heating, filtration, softening, reverse osmosis (RO), deionization (DI), UV irradiation, distillation, etc. This can produce purified water that meets thresholds for chemical purity as well as microbial and endotoxin purity. A supply pump 15 is arranged to pump purified water F1 to the RRT machine 30 in a first fluid path (“supply path”) 21, and a pressure sensor 16 is arranged to measure the fluid pressure in the supply path 21. In the illustrated example, the WPD 10 is also configured to receive used dialysis fluid F2 from the RRT machine 30 in a second fluid path (“discharge path”) 22. Fluid paths 21, 22 may be defined by flexible tubing and / or channels in the housing and may be permanently or releasably connected to the WPD 10 and the RRT machine 30. A discharge pump 17 is arranged to pump used dialysis fluid from the discharge path 22 to a discharge line 19 or to a container (not shown), and a pressure sensor 18 is arranged to measure the fluid pressure in the discharge path 22. Pressure sensors 16, 18 can be seen defining a pressure sensor arrangement in the WPD 10.

[0038] exist Figure 1A In an alternative embodiment of system 1, source 40 is configured to supply at least partially purified water. In such an alternative, water treatment unit 12 can be simplified or even omitted.

[0039] The RRT machine 30 includes an inlet valve 32, an outlet valve 33, a first scale 34, a second scale 35, a fluid generation unit 36, a treatment unit 37, a first fluid bag 38, and a second fluid bag 39. The first fluid bag 38 is disposed on the scale 34, and the second fluid bag 39 is disposed on the second scale 35. The control unit 31 is operable to open the inlet valve 32 to allow purified water F1 to enter the fluid bag 38 from the WPD 10 along the supply path 21 for intermediate storage. The purified water F1 is transferred from the fluid bag 38 to the fluid generation unit 36, which is configured to generate dialysis fluid F2' from the purified water F1. As described above, the fluid generation unit 36 ​​can be configured to mix one or more concentrates or substances (powder or liquid) with purified water to form dialysis fluid. Dialysis fluid F2' is supplied to the treatment unit 37, which is configured to perform dialysis treatment on the blood of a patient (not shown). Treatment unit 37 is configured to transfer used dialysis fluid F2 to fluid bag 39 for intermediate storage. In some embodiments, control unit 31 uses readings from scale 34 to determine the amount of dialysis fluid F2' supplied to treatment unit 37, and control unit 31 uses readings from scale 35 to determine the amount of used dialysis fluid F2 provided by dialysis treatment for calculating one or more treatment parameters related to ultrafiltration. Control unit 31 is operable to open outlet valve 33 to allow used dialysis fluid F2 to be drawn into WPD 10 via discharge path 22. Dialysis treatment itself is well known to those skilled in the art and will not be described further herein. Those skilled in the art also understand that RRT machine 30 may be partially formed from disposable items that are discarded after dialysis treatment. Such disposable items may include at least a portion of fluid bags 38, 39, fluid generation unit 36, and at least a portion of treatment unit 37. For example, conventional practice is to mount disposable tubing assemblies and disposable dialyzers on RRT machine 30 to define a dialysis fluid circuit and an extracorporeal blood circuit in treatment unit 37. It can also be noted that pressure sensors 16, 18 may be included in the disposable article and connected to transmit signals to WPD 10 when the disposable article is installed. The disposable article may also include fluid paths 21, 22. In some embodiments, valves 32, 33 are pinch valves.

[0040] Figure 1B This is a schematic diagram of treatment system 1, which includes a fluid preparation device FPD 30A (“first device”) and an RRT machine 30B (“second device”), connected for fluid communication. FPD 30A is configured to generate dialysis fluid F1 and supply it to the RRT machine 30, and to receive used dialysis fluid F2 from the RRT machine 30. The following description will focus on... Figure 1AThe differences lie in the system. The FPD 30A is essentially similar to the WPD 10, including a control unit 11, connector 13, inlet valve 14, supply pump 15, first pressure sensor 16, discharge pump 17, and second pressure sensor 18. However, compared to the WPD 10, the FPD 30A connects to a source 10 of purified water F0 via connector 13 and includes a fluid generation unit 36 ​​configured to generate dialysis fluid F1. The fluid generation unit 36 ​​may correspond to... Figure 1A The fluid generation unit 36 ​​in the RRT machine 30 can have a different configuration. Typically, the fluid generation unit 36 ​​in the FPD 30A can be configured to mix one or more concentrates or substances with purified water F0 to form dialysis fluid F1.

[0041] RRT machine 30B is basically similar to Figure 1A The RRT machine 30 includes a control unit 31, an inlet valve 32, an outlet valve 33, a first scale 34, a second scale 35, a treatment unit 37, a first fluid bag 38, and a second fluid bag 39. However, the RRT machine 30B does not have a functional equivalent of the fluid generation unit 36. The control unit 31 is operable to open the inlet valve 32 to allow dialysis fluid F1 to enter the fluid bag 38 from the FPD 30A along the supply path 21 for intermediate storage. The dialysis fluid F1 is transferred from the fluid bag 38 to the treatment unit 37, which can be connected to... Figure 1A The treatment unit 37 is identical to the one described above. Treatment unit 37 is configured to transfer used dialysis fluid F2 to fluid bag 39 for intermediate storage. In some embodiments, control unit 31 uses readings from scale 34 to determine the amount of dialysis fluid F1 supplied to treatment unit 37, and control unit 31 uses readings from scale 35 to determine the amount of used dialysis fluid F2 provided by dialysis treatment for calculating one or more treatment parameters related to ultrafiltration. Control unit 31 is operable to open outlet valve 33 to allow used dialysis fluid F2 to be drawn into FPD 30A via discharge path 22.

[0042] Figure 1C yes Figures 1A-1BA schematic block diagram of the corresponding control units 11 and 31 is provided. Control units 11 and 31 are configured to generate control signals Ci for controlling the operation of the first / second device according to a control program including computer instructions. The control program can also be configured to operate based on input signals Si received by control units 11 and 31. In WPD 10, control unit 11 can be connected to provide control signals to valve 14, water treatment unit 12, and pumps 15 and 17, and to receive input signals from pressure sensors 16 and 18. In RRT machine 30, control unit 31 can be connected to provide control signals to valves 32 and 33, fluid generation unit 36, and treatment unit 37, and to receive input signals from scales 34 and 35. In FPD 30A, control unit 11 can be connected to provide control signals to valve 14, fluid generation unit 36, and pumps 15 and 17, and to receive input signals from pressure sensors 16 and 18. In the RRT machine 30B, a control unit 31 can be connected to provide control signals to valves 32, 33 and treatment unit 37, and to receive input signals from scales 34, 35. The foregoing is merely a simplified example, and the corresponding control units 11, 31 can be configured to generate additional control signals Ci and receive additional input signals Si, as readily understood by those skilled in the art.

[0043] The corresponding control units 11 and 31 include a processor 51 and a computer memory 52. ​​The control program is stored in the memory 52 and executed by the processor 51. The control program may be supplied to the control units 11 and 31 on a computer-readable medium or by transmitting signals; the computer-readable medium may be a tangible (non-transitory) product (e.g., magnetic media, optical disc, read-only memory, flash memory, etc.). In the illustrated example, the control units 11 and 31 include a signal interface 53A for providing control signals Ci and receiving input signals Si. In the illustrated example, the control units 11 and 31 also include an input interface 53B for connecting to one or more input devices 54 that enable an operator to input control data, and an output interface 53C for connecting to one or more output devices 55 for providing feedback data to the operator. For example, the input devices 54 may include a keyboard, keypad, computer mouse, control buttons, touchscreen, printer, microphone, etc., and the output devices 55 may include a display device, touchscreen, indicator light, alarm device, speaker, etc.

[0044] Figure 2A It is used for control Figure 1A and Figure 1BThe flowchart illustrates method 200 for the first devices 10, 30A in system 1. Method 200 can be executed by control unit 11. In step 201, supply pump 15 is intermittently activated to pump fluid F1 supplied by the first devices 10, 30A into supply path 21 and towards the second devices 30, 30B. Step 202 is performed during step 201 and involves measuring the fluid pressure in supply path 21, for example, in a measurement signal from pressure sensor 16. In step 203, supply pump 15 is deactivated when the fluid pressure indicates that the inlet valve 32 of the second devices 30, 30B is closed, for example, if the fluid pressure exceeds a limit value. Thus, the first devices 10, 30A implement the above-described TAE method to supply fluid F1 to the second devices 30, 30B.

[0045] It should be understood that if the inlet valve 32 opens when the supply pump 15 is started via step 201, fluid F1 will be pumped into container 38. In some embodiments, the supply pump 15 will remain started until a measured fluid pressure indicates that the inlet valve 32 is closed. It is also conceivable to control the start-up based on predefined settings (e.g., a maximum limit on the start-up duration of the supply pump 15 or the amount of fluid pumped during start-up). For example, when such a maximum limit is exceeded, the supply pump 15 can be automatically shut down even if the fluid pressure indicates that the inlet valve 32 is still open. This automatic shutdown can indicate an operational error in the first or second device, and the first device can, for example, […]. Figure 1C The output device 55 generates alarms or alerts for the operator.

[0046] If inlet valve 32 is closed when pump 15 starts, it may be necessary to quickly stop pump 15 via step 203 to avoid excessive fluid pressure buildup that could lead to leakage in supply path 21 or at its connection to the first and second devices. To mitigate the risk of excessive fluid pressure and enable the use of a simpler pump 15, compliant device 23 may be arranged in fluid communication with supply path 21, such as... Figures 1A-1BAs shown. The compliant device 23 is configured to absorb a portion of the increased pressure in the supply path 21. The compliant device 23 can be an expandable conduit section or chamber disposed anywhere between the supply pump 15 and the inlet valve 32. Alternatively or additionally, the compliant device 23 can be included in the pump 15. For example, the pump 15 can be configured to leak fluid (referred to as “slippage”) relative to the pumping direction when pressure accumulates downstream of the pump 15. In some embodiments, the pump 15 has selected slippage characteristics based on pressure. Non-limiting examples include peristaltic pumps or gear pumps configured with a selected degree of closure. Alternatively or additionally, the accumulation of excessive fluid pressure in the supply path 21 can be mitigated by configuring the inlet valve 32 to have a soft-close function. The soft-close function can be achieved by operating and / or configuring the inlet valve 32 to close slowly. In this case, “slowly” means controlling the response time of the inlet valve 32 relative to the stopping time of the pump 15 to ensure that the fluid pressure in the supply path 21 is below a limit specific to the design of the supply path 15. The response time is the time required to switch the inlet valve 32 from a fully open state to a fully closed state, and the stopping time is the time required to stop the operating pump 15. In some embodiments, the inlet valve 32 has a response time of 1-10 seconds.

[0047] In some embodiments, pressure sensor 16 is a pressure switch or includes a pressure switch configured to indicate when the fluid pressure exceeds a configurable limit pressure. Step 203 can be derived from the signal generated by the pressure switch (see...). Figure 1C The state of inlet valve 32 is inferred from the Si signal. The presence of the signal indicates that inlet valve 32 is closed, and the absence of the signal indicates that inlet valve 32 is open.

[0048] Figure 2B It is used for control Figure 1A The flowchart below shows the method 210 of the second device 30 in System 1. Method 210 can be executed by control unit 31. In step 211, the fluid generation unit 36 ​​is operated to generate dialysis fluid F2' from purified water F1 in container 38 and supplies dialysis fluid F2' to treatment unit 37. In some embodiments, step 211 can be arranged for so-called "online generation" of dialysis fluid, meaning that the dialysis fluid is generated at a rate matching the consumption of dialysis fluid by treatment unit 37. In other words, dialysis fluid is generated on demand for use by treatment unit 37. Step 212 is performed during step 211 and involves measuring the fill level in container 38. Figure 1AIn this process, the filling level can be inferred from the weight measured by scale 34. When the filling level drops below the lower limit, step 213 opens the inlet valve 32. Step 213 can keep the inlet valve 32 open until the filling level in container 38 reaches the upper limit, at which point the inlet valve 32 closes and container 38 has been replenished with purified water F1. Since the first device 10 performs method 200 and the second device 30 performs method 210, container 38 will be replenished without synchronization between the first device 10 and the second device 30.

[0049] Figure 2C It is used for control Figure 1B The flowchart shows method 210' of the second device 30B in system 1. Method 210' can be performed by control unit 31. In step 211', the second device 30B is operated to supply dialysis fluid F1 from container 38 to treatment unit 37, which is then operated to perform dialysis treatment. For example, dialysis fluid 31 can be drawn from container 38 by a pump (not shown) in treatment unit 37. Steps 212-213 of method 210' can be the same as steps 212-213 of method 210.

[0050] It can be done Figure 2A The method 200 is modified to control the first devices 10, 30A to obtain used dialysis fluid from the second devices 30, 30B. Corresponding to step 201, the discharge pump 17 is intermittently activated to draw fluid F2 from the second devices 30, 30B along the discharge path 22. Corresponding to step 202, the fluid pressure is measured in the discharge path 22, for example, in a measurement signal from the pressure sensor 18. Corresponding to step 203, the discharge pump 17 is deactivated when the fluid pressure indicates that the outlet valve 33 of the second devices 30, 30B is closed, for example, if the fluid pressure is below a limit value. Thus, the first devices 10, 30A implement the above-described TAE method to obtain fluid F2 from the second devices 30, 30B.

[0051] Similarly, the second devices 30, 30B can be controlled by modifying method 210. Corresponding to step 212, the fill level in container 39 is measured while dialysis treatment is performed by treatment unit 37 (see step 211). The fill level can be inferred from the weight measured by scale 35. Corresponding to step 213, when the fill level exceeds the upper limit, outlet valve 33 is opened to establish fluid communication between container 39 and discharge path 22.

[0052] Figure 2D It is through the use of Figures 1A-1BThe flowchart describes a method 220 for setting up dialysis treatment using a first device and a second device. In step 221, the first device and the second device are connected by installing a supply path 21. In step 222, the first device and the second device are connected by installing a discharge path 22. For example, paths 21 and 22 can be defined in a disposable article, which is installed on the first device and the second device. In step 223, the first device and the second device are activated, and the first device is operated according to method 200, and the second device is operated according to method 210 or 210'. Furthermore, the first device can be operated according to the above-described modifications to method 200 to remove used dialysis fluid from the second device, and the second device can be operated according to the above-described modifications to method 210 to selectively open the discharge path 22.

[0053] Figures 2E-2F Two examples are shown of the timing for starting the supply pump 15 in the first device and opening the inlet valve 32 in the second device.

[0054] exist Figure 2E In this process, supply pump 15 is started at regular time intervals Δ1 (see...). Figure 2A Step 201 in the text). Each startup (“supplementary attempt”) is indicated as 231. On the other hand, the inlet valve 32 is opened at the point in time when the amount of fluid F1 in container 38 drops below the lower limit (see step 201 in the text). Figures 2B-2C Step 213), and this point in time can change over time. Figure 2E In the diagram, the dashed line 232 indicates the time period during which the inlet valve 32 is open. In the following text, these time periods are referred to as "opening periods." Figure 2E As shown, when start-up 231 occurs during the opening period 232, start-up 231 continues until inlet valve 32 is closed. As described above, the second device can be associated with a minimum supplementary interval given by the constraints of the second device. Figure 2E In this context, the minimum replenishment interval is indicated as Δ2. min The actual time difference between the two consecutive opening periods 232 is indicated as Δ2. To ensure continuous operation of the second device, Δ1 can be set to be less than the aforementioned depletion time of container 38. Furthermore, Δ1 can be set to be less than Δ2. min For example, we can set Δ1 such that in Δ2... min Memory is in multiple startups 231, such as Figure 2E exemplified in .

[0055] exist Figure 2F In the process, when startup has already caused replenishment of container 38, the first device postpones the next startup 231 for a period of time Δ1'. After Δ1', the first device can resume startup 231 of the supply pump at regular time intervals Δ1. This can be relative to Δ2. minSet a time period Δ1' to ensure that no open time period 232 occurs during Δ1'. In one example, Δ1' is set to not exceed Δ2. min -Δ1.

[0056] exist Figure 2F In a variation of the timing diagram, the time interval Δ1 between startups 231 can vary according to any suitable function. In one example, the first device can decrease Δ1 over time until startup 231 causes the replenishment of container 38.

[0057] In another variation, the control unit 11 of the first devices 10, 30A includes a function to adjust the time interval Δ1 between startups 231 based on the timing of the previous opening period 232. Thus, the control unit 11 is configured to learn the operation of the second devices 30, 30B, for example, by using a machine learning-based function. The machine learning-based function can be restarted for each treatment session, or executed continuously for the same or different patients across multiple treatment sessions.

[0058] In all the examples described above, the start-up of supply pump 15 is performed according to a schedule, which can be predefined (including regular time intervals and / or variable time intervals based on predefined functions) or dynamically determined through machine learning.

[0059] Figures 2E-2F The timing diagrams and related descriptions, as well as the machine learning variants, also apply to the startup of discharge pump 17 and the opening of outlet valve 33.

[0060] Figure 3A This is a flowchart of another example method 300 for controlling a first device to provide fluid to a second device. For clarity, reference will be made to... Figures 1A-1BMethod 300 is described using System 1. In step 301, the supply pump 15 is started. In step 302, the fluid pressure in the supply path 21 is measured or monitored. If step 303 infers from the fluid pressure that the inlet valve 32 is closed, method 300 proceeds to step 304, which stops the supply pump 15. Then, step 305 pauses method 300 for a waiting period before proceeding to step 301, in which step 301, the supply pump 15 is restarted. If step 303 infers from the fluid pressure that the inlet valve 32 is open, method 300 can proceed to step 307, which can assess whether the aforementioned maximum limit (time or amount) has been exceeded. If the maximum limit has not been exceeded, step 307 proceeds to step 302, and the supply pump 15 remains running. On the other hand, if the maximum limit has been exceeded, step 307 proceeds to step 304, which stops the supply pump 15 and optionally interrupts method 300 and generates an alarm for the operator. In a variant, step 307 is omitted. As shown by the dashed line, method 300 may include step 306, which increases the rate of supply pump 15 over time according to any suitable function. Step 306 allows supply pump 15 to be started at a low pumping rate to reduce the risk of excessive pressure accumulating in the supply path before inlet valve 32 is detected to be closed in step 303, and stops supply pump 15 after being deactivated via step 304. Returning to step 305, the waiting period may be a fixed time period, for example, to achieve… Figure 2E The rule time interval Δ1 is specified in step 305. In a variant, step 305 can apply different waiting periods for different conditions. For example, if container 38 is considered to have been replenished, the waiting period can be set to Δ1'; otherwise, it can be set to Δ1.

[0061] Figure 3B This is a flowchart of a corresponding method 310 for controlling the first device to extract fluid from the second device. For clarity, reference will be made to... Figures 1A-1B Method 310 is described using System 1. In step 311, the discharge pump 17 is started. In step 312, the fluid pressure in the discharge path 22 is measured or monitored. If step 313 infers from the fluid pressure that the outlet valve 33 is closed, method 310 proceeds to step 314, which stops the discharge pump 17. Then, step 315 pauses method 310 for a waiting period before proceeding to step 311, in which step 311, the discharge pump 17 is restarted. Similar to... Figure 3ASteps 305 and 315 in method 310 can use a fixed waiting period or apply different waiting periods for different conditions. If step 313 infers from the fluid pressure that the outlet valve 33 is open, method 310 can proceed to step 317, which can assess whether the maximum limit (time or amount) has been exceeded. If the maximum limit has not been exceeded, step 317 proceeds to step 312, and the discharge pump 17 remains running. On the other hand, if the maximum limit has been exceeded, step 317 proceeds to step 314, which stops the discharge pump 17 and optionally interrupts method 310 and generates an alarm for the operator. In a variant, step 317 is omitted. As shown by the dashed line, method 310 may include step 316, which increases the speed of the discharge pump 17 corresponding to step 306 in method 300.

[0062] Figures 1A-1B The system described is given by way of example only. The embodiments are generally applicable to any system used for supplying medical fluids for use in RRT, wherein a first fluid of any type is pumped from a first device to a second device configured to supply medical fluid based on the first fluid. The second device may be configured to perform RRT, as in... Figures 1A-1B The system is as described above. Alternatively, the second device can be arranged to supply medical fluid to the separate device performing RRT. The medical fluid can be any fluid consumed during RRT. For example, instead of dialysis fluid, the medical fluid can be an alternative fluid used in convection therapy such as hemofiltration or hemodialysis filtration. It should be understood that the first device is configured to supply medical fluid at a quality suitable for its use during RRT.

[0063] In addition, the filling level of the corresponding containers 38 and 39 can be determined by other devices besides the scale, such as a level sensor that can be arranged for continuous or point level sensing. Such other devices include, but are not limited to, pneumatic sensors, conductive sensors, probe-based sensors, float-based sensors, optical sensors, or ultrasonic sensors.

[0064] It should be noted that any type of sensor device can be installed to sense the pressure in fluid paths 21, 22, directly or indirectly. Therefore, the corresponding pressure sensors disclosed herein can be replaced by another sensor configured to measure parameters indicating fluid pressure. In one example, the fluid pressure in fluid paths 21, 22 is indirectly given by the power consumption parameters of the corresponding pumps 15, 17. For example, the power consumption parameters may represent the drive current and / or drive voltage of pumps 15, 17. In another example, at least for some types of pumps, the fluid pressure may be indirectly given by the speed of pumps 15, 17.

[0065] It can also be noted that the extraction of used medical fluid from the second device by the first device can be omitted. For example, the used medical fluid can be directly pumped to a discharge pipe or storage container through the second device.

[0066] While the subject matter of this disclosure has been described in conjunction with embodiments that are now considered to be the most practical and preferred, it should be understood that the subject matter of this disclosure is not limited to the disclosed embodiments, but rather is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0067] The following section sets forth a set of provisions to summarize some aspects and embodiments of the invention as disclosed above.

[0068] C1. A system for supplying a medical fluid (F2'; F1) for renal replacement therapy, the system comprising: a first device (10; 30A) configured to provide a first fluid (F1), the first device (10) including a fluid pump (15) and a first control unit (11); a second device (30; 30B) configured to supply the medical fluid (F2'; F1) by using the first fluid (F1), the second device (30; 30B) including a container (38), a control valve (32) and a second control unit (31); wherein the first device and the second device are connected to the second device (30) via the control valve (32) in connection with the fluid pump (15) in the first device (10). A fluid path (21) is established between the containers (38) in (30B); wherein the second control unit (31) is configured to selectively operate the control valve (32) to open the fluid path (21); wherein the first control unit (11) is connected to sensor devices (16, 18) configured to measure parameters indicating the fluid pressure in the fluid path (21); and wherein the first control unit (11) is configured to intermittently and independently of the parameters during operation of the second device (30; 30B) to pump the first fluid (F1) into the fluid path (21), and to deactivate the fluid pump (15) when the parameters indicate that the control valve (32) is closed.

[0069] C2. The system according to C1, wherein the first control unit (11) is configured to start the fluid pump (15) according to a schedule.

[0070] C3. The system according to C1 or C2, wherein the first control unit (11) is configured to start the fluid pump (15) at regular time intervals (Δ1).

[0071] C4. The system according to any of the preceding clauses, wherein the first control unit (11) is configured to separate the continuous start-up of the fluid pump (15) by a time interval less than the expected time when the container (38) is depleted when the fluid path (21) is opened by the second control unit (31).

[0072] C5. A system according to any of the preceding clauses, wherein the first control unit (11) is configured to delay the start-up of the fluid pump by a waiting period (Δ1') after the first fluid (F1) has been transferred to the container (38) via the first device (10; 30A), wherein the waiting period (Δ1') is relative to a predetermined time interval (Δ2) between consecutive opening of the fluid path (21) via the second control unit (31). min To set it.

[0073] C6. The system according to any of the preceding clauses, wherein the second control unit (31) is configured to determine the fill level in the container (38) and to open the control valve (32) when the fill level is below a limit value.

[0074] C7. The system according to C6, wherein the second device (31) further includes a scale (34) arranged to measure the weight of the container (38), and wherein the second control unit (31) is connected to the scale (34) and configured to determine the filling level based on the weight measured by the scale (34).

[0075] C8. The system according to any of the preceding clauses, wherein the first control unit (11) is configured to operate the fluid pump (15) according to a predefined setting and / or operate the fluid pump (15) until the parameter indicates that the control valve (32) is closed after the fluid pump (15) is started and when the parameter indicates that the control valve (32) is open.

[0076] C9. The system according to any of the preceding clauses, wherein the first control unit (11) is configured to start the fluid pump (15) to operate at a first speed, and to operate the fluid pump (15) at a second speed higher than the first speed when parameters indicate that the control valve (32) is open.

[0077] C10. The system according to any of the preceding clauses, wherein the fluid path (21) includes a compliant device (23) configured to absorb a portion of the increase in fluid pressure caused by the start-up of the fluid pump (15) when the control valve (32) is closed.

[0078] C11. The system according to any of the preceding clauses, wherein the response time of the control valve (32) is controlled relative to the stopping time of the fluid pump (15) to maintain the fluid pressure below a limit value.

[0079] C12. The system according to any of the preceding clauses, wherein the sensor device (16, 18) includes a pressure switch configured to signal when the fluid pressure exceeds a limit pressure.

[0080] C13. The system according to any of the preceding clauses, wherein the first fluid (F1) is purified water.

[0081] C14. The system according to any one of C1-C12, wherein the first fluid (F1) is the medical fluid.

[0082] C15. The system according to any of the preceding clauses, wherein the medical fluid (F2'; F1) is a dialysis fluid.

[0083] C16. The system according to any of the preceding clauses, wherein the second device (30; 30B) is a dialysis machine.

[0084] C17. The system according to C16, wherein the second device (30; 30B) is a dialysis machine for treating acute kidney injury (AKI).

[0085] C18. A system according to any of the preceding clauses, wherein the second device (30; 30B) includes a second container (39) and a second control valve (33), the second container being arranged to contain used medical fluid (F2), wherein the first device (11) includes a second fluid pump (17), wherein the first and second devices (10, 30; 30A, 30B) are connected to establish a second fluid path (22) between the second fluid pump (17) in the first device (10) and the second container (39) in the second device (30; 30B) via the second control valve (33), wherein the second control unit (3 1) The first control unit (11) is configured to selectively operate the second control valve (33) to open the second fluid path (22), wherein the sensor devices (16, 18) are also configured to measure another parameter indicating the fluid pressure in the second fluid path (22), and wherein the first control unit (11) is configured to intermittently and independently of the other parameter during operation of the second device (30; 30B) to draw used medical fluid (F2) from the second fluid path (22), and to deactivate the second fluid pump (17) when the other parameter indicates that the second control valve (33) is closed.

[0086] C19. A system for processing used medical fluid (F2) from renal replacement therapy, the system comprising: a first device (10; 30A) including a fluid pump (17) and a first control unit (11); a second device (30; 30B) including a container (39) arranged to collect the used medical fluid (F2), a control valve (33), and a second control unit (31); wherein the first and second devices (10, 30; 30A, 30B) are connected to establish a connection between the fluid pump (17) in the first device (10; 30A) and the container (39) in the second device (30; 30B) via the control valve (33). A fluid path (22) is established; wherein the second control unit (31) is configured to selectively operate the control valve (33) to open the fluid path (22); wherein the first control unit (11) is connected to a sensor device (16, 18) configured to measure a parameter indicating the fluid pressure in the fluid path (22); and wherein the first control unit (11) is configured to intermittently and independently of the parameter to start the fluid pump (17) to draw used medical fluid (F2) from the fluid path (22), and to deactivate the fluid pump (17) when the parameter indicates that the control valve (33) is closed.

[0087] C20. A method performed by a first device (10; 30A) in fluid communication with a second device (30; 30B), the second device supplying a medical fluid (F2'; F1) for renal replacement therapy using a first fluid (F1), the method comprising: intermittently activating (201) a fluid pump in the first device to pump the first fluid along a fluid path extending between the fluid pump in the first device and a container in the second device via a control valve in the second device while operating the second device to supply the medical fluid; obtaining (202) a measurement of a parameter indicating the fluid pressure in the fluid path from a sensor device; and deactivating (203) the fluid pump when the parameter indicates that the control valve is closed.

[0088] C21. A method performed by a first device (10; 30A) in fluid communication with a second device (30; 30B), the second device providing used medical fluid (F2) from renal replacement therapy, the method comprising: intermittently activating (211) a fluid pump in the first device to draw the used medical fluid along a fluid path extending between the fluid pump in the first device and the container in the second device via a control valve in the second device while operating the second device to collect the used medical fluid in a container in the second device; obtaining (212) a measurement of a parameter indicating the fluid pressure in the fluid path from a sensor device; and deactivating (213) the fluid pump when the parameter indicates that the control valve is closed.

[0089] C22. A computer-readable medium comprising program instructions that, when executed by a processor (51), cause the processor (51) to perform the method described in accordance with clause C20 or C21.

Claims

1. A system for supplying medical fluids (F2'; F1) for renal replacement therapy, the system comprising: A first device (10; 30A) is configured to provide a first fluid (F1), the first device (10) including a fluid pump (15) and a first control unit (11). A second device (30; 30B) is configured to supply the medical fluid (F2'; F1) using the first fluid (F1), the second device (30; 30B) comprising a container (38), a control valve (32), and a second control unit (31). The first device and the second device are connected to establish a fluid path (21) between the fluid pump (15) in the first device (10) and the container (38) in the second device (30; 30B) via the control valve (32). The second control unit (31) is configured to selectively operate the control valve (32) to open the fluid path (21). The first control unit (11) is connected to sensor devices (16, 18), which are configured to measure parameters indicating the fluid pressure in the fluid path (21). The first control unit (11) is configured to intermittently and independently of the parameters to start the fluid pump (15) during operation of the second device (30; 30B) to pump the first fluid (F1) into the fluid path (21), and to deactivate the fluid pump (15) when the parameters indicate that the control valve (32) is closed.

2. The system according to claim 1, wherein, The first control unit (11) is configured to start the fluid pump (15) according to a schedule.

3. The system according to claim 1 or 2, wherein, The first control unit (11) is configured to start the fluid pump (15) at regular time intervals (Δ1).

4. The system according to any of the preceding claims, wherein, The first control unit (11) is configured to separate the continuous start-up of the fluid pump (15) by a time interval less than the expected time when the container (38) is depleted when the fluid path (21) is opened by the second control unit (31).

5. The system according to any of the preceding claims, wherein, The first control unit (11) is configured to delay the start-up of the fluid pump by a waiting period (Δ1') after the first fluid (F1) has been transferred into the container (38) via the first device (10; 30A), wherein the waiting period (Δ1') is relative to a predetermined time interval (Δ2) between consecutive opening of the fluid path (21) via the second control unit (31). min To set it.

6. The system according to any of the preceding claims, wherein, The second control unit (31) is configured to determine the filling level in the container (38) and open the control valve (32) when the filling level is below a limit value.

7. The system according to claim 6, wherein, The second device (30) further includes a scale (34) arranged to measure the weight of the container (38), wherein the second control unit (31) is connected to the scale (34) and configured to determine the filling level based on the weight measured by the scale (34).

8. The system according to any of the preceding claims, wherein, The first control unit (11) is configured to operate the fluid pump (15) according to a predefined setting and / or operate the fluid pump (15) until the parameter indicates that the control valve (32) is closed after the fluid pump (15) is started and when the parameter indicates that the control valve (32) is open.

9. The system according to any of the preceding claims, wherein, The first control unit (11) is configured to start the fluid pump (15) to operate at a first speed, and to operate the fluid pump (15) at a second speed higher than the first speed when the parameters indicate that the control valve (32) is open.

10. The system according to any of the preceding claims, wherein, The fluid path (21) includes a compliant device (23) configured to absorb a portion of the increase in fluid pressure caused by the start-up of the fluid pump (15) when the control valve (32) is closed.

11. The system according to any of the preceding claims, wherein, The response time of the control valve (32) is controlled relative to the stopping time of the fluid pump (15) to keep the fluid pressure below the limit value.

12. The system according to any of the preceding claims, wherein, The sensor devices (16, 18) include a pressure switch configured to send a signal when the fluid pressure exceeds a limit pressure.

13. The system according to any of the preceding claims, wherein, The first fluid (F1) is purified water.

14. The system according to any one of claims 1-12, wherein, The first fluid (F1) is the medical fluid.

15. The system according to any of the preceding claims, wherein, The medical fluids (F2'; F1) are dialysis fluids.

16. The system according to any of the preceding claims, wherein, The second device (30; 30B) is a dialysis machine.

17. The system according to claim 16, wherein, The second device (30; 30B) is a dialysis machine for treating acute kidney injury (AKI).

18. The system according to any of the preceding claims, wherein, The second device (30; 30B) includes a second container (39) and a second control valve (33), the second container being arranged to contain used medical fluid (F2), wherein the first device (10) includes a second fluid pump (17), wherein the first device and the second device (10, 30; 30A, 30B) are connected to establish a second fluid path (22) between the second fluid pump (17) in the first device (10) and the second container (39) in the second device (30; 30B) via the second control valve (33), wherein the second control unit (31) is configured to select The second control valve (33) is selectively operated to open the second fluid path (22), wherein the sensor devices (16, 18) are also configured to measure another parameter indicating the fluid pressure in the second fluid path (22), and wherein the first control unit (11) is configured to intermittently and independently of the other parameter during operation of the second device (30; 30B) to draw used medical fluid (F2) from the second fluid path (22), and to deactivate the second fluid pump (17) when the other parameter indicates that the second control valve (33) is closed.

19. A system for treating used medical fluid (F2) from renal replacement therapy, the system comprising: The first device (10; 30A) includes a fluid pump (17) and a first control unit (11). The second device (30; 30B) includes a container (39) arranged to collect used medical fluid (F2), a control valve (33), and a second control unit (31). The first device and the second device (10, 30; 30A, 30B) are connected to establish a fluid path (22) between the fluid pump (17) in the first device (10; 30A) and the container (39) in the second device (30; 30B) via the control valve (33). The second control unit (31) is configured to selectively operate the control valve (33) to open the fluid path (22). The first control unit (11) is connected to sensor devices (16, 18), which are configured to measure parameters indicating the fluid pressure in the fluid path (22). The first control unit (11) is configured to intermittently and independently of the parameters start the fluid pump (17) to draw used medical fluid (F2) from the fluid path (22), and to stop the fluid pump (17) when the parameters indicate that the control valve (33) is closed.

20. A method performed by a first device (10; 30A) in fluid communication with a second device (30; 30B), the second device supplying a medical fluid (F2') for renal replacement therapy using a first fluid (F1); F1), the method includes: While operating the second device to supply the medical fluid, the fluid pump in the first device is intermittently activated (201) to pump the first fluid along a fluid path that extends between the fluid pump in the first device and the container in the second device via a control valve in the second device. (202) Measured values ​​of parameters indicating fluid pressure in the fluid path are obtained from the sensor device; and When the parameter indicates that the control valve is closed, the fluid pump (203) is deactivated.

21. A first device (10; 30B) in fluid communication with a second device (30; 30B) 30A) The method performed, wherein the second device provides used medical fluid (F2) from renal replacement therapy, the method comprising: While operating the second device to collect the used medical fluid in a container in the second device, (211) the fluid pump in the first device is intermittently activated to draw the used medical fluid along a fluid path that extends between the fluid pump in the first device and the container in the second device via a control valve in the second device. (212) Measured values ​​of parameters indicating fluid pressure in the fluid path are obtained from the sensor device; and When the parameter indicates that the control valve is closed, the fluid pump (213) is deactivated.

22. A computer-readable medium comprising program instructions that, when executed by a processor (51), cause the processor (51) to perform the method according to claim 20 or 21.

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