Supplying medical fluid from first system to second system

Abstract

A first system (10) is operable to supply a medical fluid to a fluid reservoir (21) of a second system (20). A control arrangement (11) in the first system (10) performs a control method to automatically adjust the operation of the first system (10) to the operation of the second system (20). In the control method, a signal indicative of a power consumption of the second system (20) as a function of time is obtained, the signal is evaluated for determination of a time point to supply the medical fluid to the fluid reservoir (21), and the first system (10) is operated to start supplying the medical fluid at the time point.

Description

[0001] SUPPLYING MEDICAL FLUID FROM FIRST SYSTEM TO SECOND SYSTEM

[0002] Technical Field

[0003] The present disclosure relates generally to fluid distribution, and in particular to a technique of operating a first system to supply a medical fluid to a fluid reservoir of a second system with proper timing relative to the operation of the second system. The technique is suitable for use in the context of dialysis.

[0004] Background Art

[0005] In the treatment of individuals suffering from acute or chronic renal insufficiency, dialysis therapy may be needed. One category of dialysis therapy is peritoneal dialysis (PD). In PD, a treatment fluid ("dialysis fluid") is infused into the individual's peritoneal cavity, also known as abdominal cavity. This cavity is lined by a peritoneal membrane ("peritoneum") which is highly vascularized. Substances are removed from the patient's blood mainly by diffusion across the peritoneum into the treatment fluid. Excess fluid (water) is also removed by osmosis induced by the treatment fluid being hypertonic.

[0006] In automated peritoneal dialysis (APD), the dialysis treatment is controlled by a machine, commonly known as a "cycler". The cycler is connected in fluid communication with the peritoneal cavity and is operated to control the flow of fresh dialysis fluid into the peritoneal cavity and the flow of spent dialysis fluid from the peritoneal cavity.

[0007] Conventional PD cyclers are configured to prepare the dialysis fluid by mixing purified water, obtained from a water purification system, with concentrates from containers that are removably attached to the PD cycler. The mixing takes place in a disposable device, which is installed in the PD cycler before therapy. The disposable device includes fluid lines for water and concentrates, as well as a patient line for fluid communication with the peritoneal cavity and a drain line for disposal of spent dialysis fluid. The disposable device also includes a fluid bag, which is arranged to hold the dialysis fluid that is prepared by the PD cycler. An example of such a PD cycler is disclosed in WO2017 / 193073.

[0008] It is envisioned to provide a separate machine for generating the dialysis fluid and supplying the dialysis fluid to the PD cycler. By making such a fluid preparation machine available, the complexity of PD cyclers may be reduced significantly. Also, the above-mentioned disposable device may be reduced in size, resulting in less waste and improved use of resources. Such a fluid preparation machine needs to be operated with proper timing relative to the operation of the PD cycler. This may be achieved by data signaling between the fluid preparation machine and the PD cycler through dedicated communication interfaces and by use of a shared communication protocol. Such data signaling adds cost to the PD cycler and the fluid preparation machine, and reduce inter-operability between equipment from different manufacturers and between old and new equipment.

[0009] This technical challenge is applicable to other situations in which a medical fluid is actively transferred from a first system to a second system.

[0010] The prior art also comprises US2022 / 0409792.

[0011] Summary

[0012] It is an objective to at least partly overcome one or more limitations of the prior art.

[0013] One objective is to provide a technique of operating a first system to supply a medical fluid to a second system with proper timing relative to the operation of the second system.

[0014] Another objective is to provide such a technique that does not rely of the use of communication interfaces on the first and second systems.

[0015] Yet another objective is to provide such a technique that is suitable for use in a first device, which is configured to supply treatment fluid to a second device that performs PD therapy by use of the treatment fluid.

[0016] One or more of these objectives, as well as further objectives that may appear from the description below, are at least partly achieved by computer-implemented methods, control arrangements, a computer-readable medium, and systems according to the independent claims, embodiments thereof being defined by the dependent claims.

[0017] The present disclosure proposes a technique of configuring a first system, which is operable to supply a medical fluid to a fluid reservoir of a second system, to monitor the power consumption of the second system for determination of a suitable time point to supply the medical fluid to the fluid reservoir. This technique obviates the need to equip the first and second systems with conventional communication interfaces for data signaling to synchronize their operation. The power consumption may be conveniently monitored in the first system if the second system is connected to receive its electrical power via the first system. Alternatively, the power consumption of the second system may be monitored by a separate power meter and conveyed to the first system.

[0018] Still other objectives and technical effects, as well as aspects, embodiments, features and advantages may appear from the following detailed description, from the attached claims as well as from the drawings. Brief Description of the Drawings

[0019] FIG. 1 shows an example APD arrangement comprising a supply system for supplying treatment fluid, and a therapy system for performing APD by use of the treatment fluid.

[0020] FIG. 2 is a more detailed view of an example APD arrangement comprising a supply system and a therapy system.

[0021] FIGS 3A-3C are flow charts of example methods performed by a supply system in an APD arrangement in accordance with embodiments.

[0022] FIG. 4 is a flow chart of an example method performed by a therapy system in an APD arrangement in accordance with embodiments.

[0023] FIG. 5 is an example plot of intraperitoneal volume versus time during a sequence of fluid exchange cycles performed by a therapy system (top) and a corresponding amount of treatment fluid in a fluid reservoir of the therapy system (bottom).

[0024] FIG. 6 is an example plot of the power consumption of a therapy system during its operation.

[0025] FIGS 7A-7D are enlarged views of the power consumption in FIG. 6 when the therapy system changes operating state.

[0026] FIGS 8A-8B are block diagrams of example control arrangements.

[0027] Detailed Description of Example Embodiments

[0028] Embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments are shown. Indeed, the subject of the present 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.

[0029] Also, it will be understood that, where possible, any of the advantages, features, functions, devices, and / or operational aspects of any of the embodiments described and / or contemplated herein may be included in any of the other embodiments described and / or contemplated herein, and / or vice versa. In addition, where possible, any terms expressed in the singular form herein are meant to also include the plural form and / or vice versa, unless explicitly stated otherwise. As used herein, "at least one" shall mean "one or more" and these phrases are intended to be interchangeable. Accordingly, the terms "a" and / or "an" shall mean "at least one" or "one or more", even though the phrase "one or more" or "at least one" is also used herein. As used herein, except where the context requires otherwise owing to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, that is, to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments.

[0030] As used herein, the terms "multiple", "plural" and "plurality" are intended to imply provision of two or more elements. The term "and / or" includes any and all combinations of one or more of the associated listed elements.

[0031] It will furthermore 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 only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing the scope of the present disclosure.

[0032] Well-known functions or constructions may not be described in detail for brevity and / or clarity. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0033] Like reference signs refer to like elements throughout.

[0034] As used herein, "dialysis therapy" or "dialysis" refers to any therapy that replaces or supplements the renal function of a patient by use of a treatment fluid. Dialysis therapy includes, without limitation, peritoneal dialysis (PD) therapy and extracorporeal (EC) blood therapy.

[0035] As used herein, "medical fluid" refers to any fluid that is consumed as a result of therapy, wherein the therapy is any medical application that involves medical treatment for remediation of a health problem of an individual, or for maintaining or improving the health of the individual. Medical fluid includes, without limitation, purified water, infusion solutions, dialysis fluid for PD therapy or EC blood therapy, replacement fluid and substitution fluid for EC blood therapy, priming fluid, and fluid for disinfection and / or cleaning.

[0036] The present disclosure relates to a technique to timely operate a first system to supply a medical fluid to a second system that performs a function or procedure by use of the medical fluid. The technique will be described with reference to peritoneal dialysis (PD) but is applicable to any medical application in which a medical fluid is supplied between two systems or machines.

[0037] FIG. 1 is a schematic view of an example arrangement for automated peritoneal dialysis (APD). The APD arrangement comprises a first system or apparatus 10, which is configured to supply a medical fluid. The first system 10 is also denoted "fluid supply system" herein. The first system 10 includes a combination of components for performing the function of supplying the medical fluid. In FIG. 1, this combination of components ("sub-system" or "arrangement") is indicated by dashed lines and designated reference sign 10a. In one example, the sub-system 10a is configured to pump fluid from a container or bag of ready-made medical fluid. In another example, the sub-system 10a is configured to generate the medical fluid. The components in the sub-system 10a may include one or more fluid lines, one or more fluid pumps, one or more valves, one or more sensors, one or more heaters, etc.

[0038] The APD arrangement further comprises a second system 20, which is configured to receive the medical fluid from the first system 10 in a fluid reservoir 21. The second system is also denoted "downstream system" herein. The second system 20 includes a combination of components for performing a function by use of the medical fluid in the fluid reservoir 21. In FIG. 1, this combination of components ("sub-system" or "arrangement") is indicated by dashed lines and designated reference sign 20a. The components in the sub-system 20a may include one or more fluid lines, one or more fluid pumps, one or more valves, one or more sensors, one or more heaters, etc. In the example of FIG. 1, the second system 20 is configured to perform PD therapy, and the medical fluid is a treatment fluid. To perform PD therapy, as shown, the second system 20 is fluidly connected to the peritoneal cavity PC of a patient P. As indicated by a double-ended arrow, the second system 20 is operable to convey fresh treatment fluid into the PC, and to receive spent treatment fluid ("effluent") from the PC on a fluid path 22 ("patient line"). The patient line 22 may be defined by tubing that connects to an implanted catheter (not shown) in fluid communication with the peritoneal cavity PC. The fresh treatment fluid is conveyed from the fluid reservoir 21, and the effluent is conveyed on a fluid path 23 ("drain line") to a drain 100 for disposal. The drain 100 may be a sink, toilet, bag, etc. The second system 20 further includes a fluid path 24 ("external transfer line") for receiving the treatment fluid from the first system 10. The external transfer line 24 extends to the fluid reservoir 21, in which the treatment fluid is intermittently stored before being conveyed to the PC.

[0039] PD therapy is typically implemented as daily treatment sessions, each comprising a number of fluid exchange cycles. Each fluid exchange cycle consists of a fill phase, a dwell phase and a drain phase, performed in sequence. In the fill phase (FP), fresh treatment fluid is supplied to the PC on the patient line 22. In the dwell phase (DWP), the treatment fluid resides in the PC. In the drain phase (DP), spent treatment fluid (effluent) is extracted from the PC on patient line 22.

[0040] In practice, for PD therapy, the second system 20 is an electrically controlled machine ("cycler") which is fitted with a "disposable set", which includes a pumping cassette, fluid lines, and one or more bags or containers. The fluid reservoir 21 may be such a bag or container. PD cyclers and disposable sets are well-known in the art and need no further description. Non-limiting examples are found in aforesaid WO2017 / 193073.

[0041] In the illustrated example, the first and second systems 10, 20 are configured to communicate with a back-end device 30, for example a server, over a network 31. The first and second systems 10, 20 may be connected to the network 31 by wire or wirelessly. The network 31 may be a WAN, LAN, PAN or any combination thereof. As indicated by a double-ended arrow, the second system 20 may be configured to retrieve input data from and transmit output data to the back-end device 30. The input data may include settings for an up-coming treatment session, such as the composition of the treatment fluid, the number of exchange cycles, the amount of treatment fluid per fill phase, etc. One or more settings may alternatively or additionally be entered by a user into the second system 20 via an input interface (not shown). The output data may include settings for an up-coming, on-going or completed treatment session. The back-end device 30 may store the input data and output data in association with an identifier for the patient and / or an identifier for the second system. As shown in FIG. 1, the first system 10 may also be configured to retrieve input data from and transmit output data to the back-end device 30. The input data may include the above-mentioned settings, or part thereof, to allow the first system 10 to supply a proper treatment fluid to the second system 20. For example, the input data may indicate the composition of the medical fluid to be supplied, the number of exchange cycles, the amount of treatment fluid to be supplied to the fluid reservoir 21, etc.

[0042] It is realized that the first system 10 needs to be operated with proper timing relative to the operation of the second system 20, so that the first reservoir 21 contains a sufficient amount of treatment fluid whenever required by the second system 20. As discussed in the Background section, this may be achieved by providing the systems 10, 20 with communication interfaces that allow for wired or wireless data communication between the systems 10, 20. The present disclosure relates to a technique of operating the first system 10 in relation to the second system 20 without the use of such data communication.

[0043] The technique will be described with reference to an example configuration of the first and second systems 10, 20 depicted in FIG. 2. The first system 10 is configured to generate the treatment fluid. The sub-system 10a comprises a mixing arrangement, which is operable to generate the treatment fluid by mixing one or more concentrates with water. The operation of the sub-system 10a is controlled by a local control arrangement 11 ("first controller"). In the illustrated example, the sub-system 10a is configured to receive water from a water supply system 41. The water may be purified to fulfil applicable requirements, such as "water for dialysis" or "water for infusion", and the water supply system 41 may be a separate device that is configured to generate and supply water of sufficient quality. Alternatively, the water supply system 41 may be configured to provide tap water, for example at via a water tap. If receiving tap water, the sub-system 10a includes water purification equipment (not shown) to generate water of adequate quality. In such an example, the water purification equipment and the mixing arrangement are integrated within the same housing and share the same fluid path. An intake line 12b extends from the sub-system 10a to a water inlet 12b', which may be provided with an inlet connector. A water supply line 41a extends from the water supply 41 to a terminal connector 41a' for releasable connection to the water inlet 12b'. The sub-system 10a is arranged to receive a first concentrate from a first container or bag 42, which is releasably connected to the first system 10 by a terminal connector 42a' on a first concentrate supply line 42a. In the illustrated example, the sub-system 10a is further arranged to receive a second concentrate from a second container or bag 43, which is releasably connected to the first system 10 by a terminal connector 43a' on a second concentrate supply line 43a.

[0044] A mixing arrangement in the sub-system 10a is configured to mix the water and the concentrates at a given mixing ratio to produce a treatment fluid with a required composition. The mixing ratio may be predefined and fixed. Alternatively, the mixing ratio may be given or inferred from input data retrieved by the first system 10 from the back-end device 30 (FIG. 1). The mixing arrangement may be configured to produce a batch of treatment fluid before supplying the treatment fluid to the second system 20. The batch of treatment fluid may be stored in a reservoir (not shown) within the first system 10. Alternatively, the mixing arrangement may be configured to generate the treatment fluid on-demand ("on-line"). Mixing arrangements are well-known in the field of dialysis and will not be described in further detail.

[0045] The sub-system 10a is connected to a fluid supply line 12a which extends to a fluid outlet 12a', which may be provided with an outlet connector. The sub-system 10a comprises at least one fluid pump 13, which is operated to pump the treatment fluid into the fluid supply line 12a. As shown, the sub-system 10a may comprise a heater 14, which may be operated to adjust the temperature of treatment fluid and / or to heat a disinfection fluid (for example, water) during heat disinfection of the first system 10. Heat disinfection may be performed to control microbial growth within durable fluid paths of the first system 10. It is realized that the sub-system 10a may include many other components (valves, sensors, mixing chamber, gas removal device, etc.).

[0046] The second system 20 is configured to perform PD therapy by use of the treatment fluid in the fluid reservoir 21. The fluid reservoir 21 is fluidly connected to the external transfer line 24 that extends to a fluid inlet 24', which may be provided with an inlet connector 24', for releasable connection to the fluid outlet 12a' of the first system 10. An internal transfer line 25 extends from the fluid reservoir 21 to the sub-system 20a, which is electrically operable to generate a flow of treatment fluid on the patient line 22 and to retrieve effluent on patient line 22 and direct the effluent into the drain line 23 for disposal. The operation of the sub-system 20a is controlled by a local control arrangement 26 ("second controller"). In the illustrated example, the sub-system 20a comprises electrically controllable fluid pumps 27a, 27b. It is realized that the subsystem 20a may include other electrically controllable components such as valves. In the illustrated example, the second system 20 also includes an electrical heater 28 for heating the treatment fluid in the reservoir 21 to a target temperature.

[0047] Conventionally, the reservoir 21, the transfer lines 24, 25, the patient line 22, the drain line 23, as well as further fluid lines (not shown) inside the sub-system 20a are part of the above-mentioned disposable set. The fluid pumps 27a, 27b may be part of the pumping cassette in such a disposable set. The electrical heater 28 may, for example, be integrated into a tray on which the fluid reservoir 21 is placed.

[0048] The APD arrangement in FIG. 2 is configured to distribute electrical power to the first and second systems 10, 20. In the illustrated example, the second system 20 receives electrical power from the first system 10. This configuration provides a simple way of allowing the first system 10 to monitor the power consumption of the second system 20.

[0049] In the first system 10 of FIG. 2, a power input line 15 extends between the subsystem 10a and a first electrical connector or power plug 15' for receiving input power. The connector 15' may be configured for connection to a power socket, for example a wall socket. A power output line 16 is connected to the power input line 15 at a junction 15a and extends to a second electrical connector 16'. The input and output lines 15, 16 are part of a power line arrangement for distribution of electrical power from the connector 15' to the sub-system 10a and to the connector 16'. In the second system 20, a power input line 29 extends between the sub-system 20a and an electrical connector 29' for receiving input power. The connector 29' is configured for releasable connection to the second connector 16' of the first system 10. The connectors 16', 29' may be configured as plug and socket.

[0050] In the first system 10, a power meter 17 is arranged in the power output line 16 between the junction 15a and the connector 16'. The power meter 17 is configured to generate a power signal, PS, which is a time-dependent measurement signal that represents the momentary power supplied to the second system 20. In other words, PS is indicative of the power consumption of the second system 20 as a function of time. The local controller 11 is arranged to receive PS and operate the first system 10 based thereon.

[0051] FIG. 3A is a flow chart of an example method Ml of operating the first system 10 based on the power signal, PS. The method Ml may be performed by the local controller 11 in FIG. 2. Optional steps and sub-steps are indicated by dashed lines. In step S10, the controller 11 obtains the power signal, PS. In step Sil, the controller 11 evaluates PS for determination of a time point ("first time point" or "supply time point") to supply the treatment fluid to the fluid reservoir 21 in the second system 20. In step S12, the controller 11 operates the first system 10 to start supplying the fluid at the time point determined in step Sil.

[0052] The method Ml is based on the insight that the power consumption of the second system 20 is characteristic to the operation of the second system 20 and that this allows the first system 10 to detect one or more operational stages of the second system 20 by monitoring the power consumption of the second system 20 as a function of time. This opens up a simple way of synchronizing the operations of the first and second systems 10, 20 so as to ensure that there is treatment fluid in the fluid reservoir 21 as required by the second system 20. The synchronization is achieved without conventional data communication between the systems 10, 20. The method Ml thereby enables interoperability between first and second systems 10, 20 whether or not they include hardware for data communication. The first system 10 will be able to provide treatment fluid to all types of second systems 20, irrespective of manufacturer. Also, all existing second systems 20 in medical clinics can be combined with the first system 10. The first system 10 may be configured for operation with a specific type of second system 20 by tailoring step S 11 to identify the time point to supply the treatment fluid based on the power consumption of this specific type of second system 20. This may be achieved by a software update of the first system 10.

[0053] As shown, the method Ml may include a step S10A of operating the first system 10 to transfer electrical power to the second system 20 so that the electrical power represents the power consumption of the second system 20. Thus, by step S10A, the second system 20 receives its operating power from the first system 10, for example as shown in FIG. 2. This provides a simple way for the first system 10 to monitor the power consumption of the second system 20 by a power meter 17 in the first system 10. In a variant, the first and second systems 10, 20 are separately connected to one or more power outlets for electrical power, for example a wall socket, and the power inlet line 29 of the second system 20 is connected to the power outlet via a power meter, which is configured to communicate its power signal PS to the first system 10. As shown, the method Ml may include a step SI 1A of evaluating PS to determine a second time point ("prepare time point") when to prepare the first system 10 for supplying the treatment fluid to the fluid reservoir 21, and a step S12A of operating the first system 10 to start preparations for supplying the treatment fluid at the prepare time point. The preparations may include priming one or more fluid lines in the sub-system 10a, heating the treatment fluid, etc. If the sub-system 10a comprises a mixing arrangement for generating the treatment fluid, the preparations may involve operating the mixing arrangement to achieve a stable and desired composition of the treatment fluid.

[0054] The first system 10 may determine both the first time point and the second time point based on PS. However, it is also conceivable that the first system 10 only determines the second time point, with the first time point being inherently given by the second time point since the required time to complete the preparations are at least approximately known to the first system (cf. Atl in FIG. 5, below). Thus, the first system 10 may automatically start to transfer the treatment fluid when the preparations are completed.

[0055] As indicated by step SI IB, step Sil may involve detecting a characteristic pattern in PS. The characteristic pattern may be seen as a fingerprint for the power consumption of the second system 20 at a specific stage of operation. The above-mentioned supply time point may thus be set in relation to the detection of the characteristic pattern.

[0056] Similarly, the prepare time point may be set in relation to the detection of another characteristic pattern in PS.

[0057] In some embodiments, the characteristic pattern is detected by pattern matching or pattern recognition. For example, the first system 10 may have access to definition data that represents one or more characteristic patterns to be detected in the power signal. The definition data may, for example, define a characteristic pattern to include a time sequence of features, such as peaks, derivatives, plateaus, etc., and relative times for such features. The first system 10 may be configured for use with a specific second system 20 by being provided with definition data for this specific second system 20.

[0058] In some embodiments, the characteristic pattern is determined by operating a trained machine-learning model on the power signal and / or signal features extracted from the power signal. Machine learning may allow for more "fuzzy" detection, by enabling detection even if the power signal deviates somewhat from the characteristic pattern. Any conventional machine-learning model for supervised classification may be used.

[0059] Examples of suitable timing for the supply of treatment fluid by the first system 10 to the second system 20 will be given with reference to FIG. 5. In a PD treatment session, the second system 20 is operated to perform one or more fluid exchange cycles ("cycles"), optionally after an initial drain phase. The initial drain phase may be performed if the patient carries a large fluid volume in the peritoneal cavity at the start of the session.

[0060] The top graph in FIG. 5 shows fluid volume in the peritoneal cavity as a function of time during a treatment session. This fluid volume is commonly known as intraperitoneal volume, IPV. In the illustrated example, the patient has a small residual volume of fluid, VR, in the peritoneal cavity at the start of the session. Two consecutive cycles Cl, C2 are shown in FIG. 5. A cycle consists of a fill phase (FP), a dwell phase (DWP) and a drain phase (DP), performed in sequence. In FP, a fluid volume VF of fresh treatment fluid is infused into the peritoneal cavity by the second system 20 via the patient line 22 (FIGS 1-2). In DWP, the treatment fluid is left to reside in the peritoneal cavity. In DP, a volume of effluent is extracted from the peritoneal cavity. Depending on the osmotic force gradient, transport of fluid from the patient 's blood into the peritoneal cavity or vice versa via the peritoneal membrane, known as ultrafiltration (UF), can be either positive, increasing IPV, or negative, decreasing IPV. During FP, DWP and DP, UF is generally positive, due to the osmotic agent in the treatment fluid. For illustration purposes, the effect of UF is only indicated for DWP in FIG. 5. The drain phase, DP, may be controlled in different ways. In one implementation ("fixed volume extraction"), the second system 20 is operated to (if possible) extract a predefined amount of effluent from the peritoneal cavity. In another implementation ("maximized extraction"), the second system 20 is operated to extract as much effluent as possible from the peritoneal cavity. This means that the duration of the drain phase will differ depending on the ultrafiltration.

[0061] The bottom graph in FIG. 5 shows the fluid volume, Vbag, in the reservoir 21 of the second system 20 as a function of time during the treatment session. In the illustrated example, the fluid volume in the reservoir 21 reciprocates between a lower volume VI and an upper volume V2, as the reservoir 21 is gradually depleted of treatment fluid during a respective fill phase (FP) and then replenished by the first system 10 after the fill phase. The upper volume V2 need not match the maximum capacity of the reservoir 21 but may rather be matched to the fluid volume VF to be infused in the respective fill phase, FP. It is generally desirable to avoid a large V 1 since this volume of treatment fluid is wasted and sent to drain when the treatment session is completed. The upper volume V2 may be given or inferred from input data retrieved by the first system 10 from the back-end device 30 (FIG. 1).

[0062] In some embodiments, it is desirable for the first system 10 to ensure that the fluid volume in the reservoir 21 contains at least a predefined minimum amount of treatment fluid at the start of the fill phase (FP). In FIG. 5, the start of FP is designated SFP and indicated by dashed circles in the bottom graph. In the example of FIG. 5, Vbag equals V2 at each SFP. The method Ml in FIG. 3A provides a convenient way of allowing the first system 10 to determine a suitable time point to start replenishing the reservoir 21. In the example of FIG. 5, upon detecting the switch between DWP and DP, at time td, the first system 10 starts to prepare for supplying treatment fluid. In FIG. 5, this preparation phase has a duration of Atl. After the preparation phase, at time ts, the first system 10 starts to supply treatment fluid to the reservoir 21. The supply phase by the first system 10 has a duration of At2 and is completed well in advance of the next SFP. In a non-limiting example, the supply phase has a duration of 5-15 minutes.

[0063] The Applicant has found that it is relatively easy to detect when the second system 20 is switched between different operating states, since the power signal PS is likely to markedly change character at switch points between operating states.

[0064] FIG. 3B is a flow chart of a method M2 that may be performed as part of step Sil in FIG. 3A. In step S20, the controller 11 detects, based on PS, at least one operating state of the second system 20. In step S21, the controller 11 determines the supply time point (optionally via the prepare time point, step SI 1A) based on the at least one operating state. The detection in step S20 may be a detection of an on-going operating state, or a switch between an on-going operating state and an upcoming operating state.

[0065] In some embodiments, step S20 may involve detecting, based on PS, a time sequence of operating states of the second system 20, and step S21 may involve determining the supply time point based on the time sequence of operating states. Thus, the controller 11 may be configured to detect plural operating states of the second system 20 and determine the supply time point is relation to the time points when the second system 20 attained the respective operating state. In the example of FIG. 5, the first system 20 may detect the start of the first FP, the start of each subsequent FP (or equivalently, the end of the respective DP), the start of the respective DWP (or equivalently, the end of the respective FP), and the start of the respective DP (or equivalently, the end of the respective DWP). Such tracking of operating states will facilitate the determination of a correct supply time point to ensure that the reservoir 21 is sufficiently filled with treatment fluid at each SFP.

[0066] FIG. 6 shows an example of the power consumption of a second system 20 (PD cycler) over time before and during a treatment session. The curve in FIG. 6 thus corresponds to the power signal PS from the power meter 17 in FIG. 2. Numerals 0-VI designate different operating states or switch points between operating states of the cycler 20. The first system 10 may process PS for detection of one or more of these operating states or switch points. Below follows a description of the respective state and how the first system 10 may operate in relation to detected states.

[0067] Numeral 0 designates a start-up state, which is performed upon power-on of the cycler 20. In the start-up state, the cycler runs an internal function test, in which electrically controlled components of the sub-system 20a are evaluated for proper operation. This results in a pattern of power consumption that is specific to state 0. Assuming that the first system 10 also has been started, the first system 10 may detect the start-up state in the power signal. Upon detection of the start-up state, the first system 10 may run an internal function test to get ready for fluid production.

[0068] Numeral I designates a dressing state, in which the disposable set is mounted onto the cycler 20 by the user. When the disposable is mounted, the user confirms this to the cycler, for example by pressing a button on the cycler. The first system 10 may detect the dressing state, start fluid production and supply fluid to the reservoir 21.

[0069] Alternatively, the user may be instructed by the cycler to press a button on the first system 10 to cause the first system 10 to start fluid production and supply treatment fluid to the reservoir 21.

[0070] Subsequent to the dressing state, the cycler enters a priming state in which fluid is pumped from the reservoir 21 to flush the disposable set. Numeral II designates the end of the priming state, which may be detected by the first system 10 without taking specific action.

[0071] At the end of the priming state, the user may press a button on the cycler 20 to indicate readiness to begin therapy. The user connects the patient line 22 to the implanted catheter in the patient, whereupon the therapy is started, for example by the user pressing a button on the cycler. In the illustrated example, the cycler first performs an initial drain of the peritoneal cavity. Numeral III designates the start of the initial drain phase (IDP), which may be detected by the first system 10 without taking specific action. FIG. 7A is an enlarged portion in the encircled area 7A of FIG. 6. The signal comprises a sequence of power spikes overlaid on a varying baseline signal. The power spikes emanate from the power control of the heater (28 in FIG. 2). The power spikes are present in most operating states and may be of less use for determining an operating state or switch point. The baseline signal, on the other hand, is indicative of the activation of other components in the sub-system 20a, such as pumps and valves, and is specific to the on-going operating state. Thus, the evaluation step Sil may involve processing the power signal for extraction of the baseline signal, which is then evaluated for determination of the supply time point. The skilled person is well aware of techniques for baseline extraction. FIG. 7A shows an example of a characteristic pattern CPI that may be detected in the baseline signal and associated with a switch point SW1 corresponding to the start of the initial drain phase (IDP).

[0072] In FIG. 5, numeral IV designates the start of a fill phase (FP), which may be detected by the first system 10 without taking specific action. FIG. 7B is an enlarged portion of the encircled area 7B in FIG. 6. Here, a characteristic pattern CP2 may be detected in the baseline signal and associated with a switch point SW2 corresponding to the start of FP.

[0073] In FIG. 5, numeral V designates the start of a dwell phase (DWP), which may be detected by the first system 10. In some embodiments, the start of DWP triggers the first system 10 to start supplying treatment fluid to replenish the reservoir 21. In other embodiments, the start of DWP is detected by the first system 10 without taking specific action. FIG. 7C is an enlarged portion in the encircled area 7C of FIG. 6. Here, a characteristic pattern CP3 may be detected in the baseline signal and associated with a switch point SW3 corresponding to the start of DWP.

[0074] Numeral VI designates the start of a drain phase (DP), which may be detected by the first system 10. In some embodiments, for example if the reservoir 21 is not replenished during DWP, the start of DP triggers the first system 10 to start supplying treatment fluid to replenish the reservoir 21. In other embodiments, for example if the reservoir 21 is replenished during DWP, the start of DP may be detected by the first system 10 without taking specific action. FIG. 7D is an enlarged portion in the encircled area 7D of FIG. 6. Here, a characteristic pattern CP4 may be detected in the baseline signal and associated with a switch point SW4 corresponding to the start of DP.

[0075] The cycler may then proceed to perform one or more further fluid exchange cycles, and the first system 10 may operate as described with reference to FIGS 6-7 during each such fluid exchange cycle. For example, numeral VII designates the start of a further fill phase (FP), which may be detected by analogy with the start of FP at numeral IV.

[0076] In the examples of FIGS 7A-7D, the characteristic pattern has a duration of about 10-20 seconds. The length of the characteristic pattern is a trade-off between detection speed and certainty of detection. The minimum length may vary between operating states or switch points and may also differ between second systems. In some embodiments, the length of the characteristic pattern corresponds to at least 5 or 10 seconds.

[0077] FIG. 3C is a flow chart of an example method M3 which may be performed as part of the method Ml in FIG. 3 A. The method M3 is based on the insight that the second system 20 may be configured to actively and deliberately adjust its power consumption to convey a message, in a broad sense, to the first system 10. In other words, the second system 20 operates to embed a predefined pattern in the power consumption. The predefined pattern is thus not inherent to the regular operation of the second system 20 when performing dialysis therapy. For example, the second system 20 may activate one or more valves or fluid pumps (cf. pumps 27 A, 27B in FIG. 2) to generate the predefined pattern. The predefined pattern is denoted "encoded pattern" in the following.

[0078] The method M3 comprises steps S30-S31, which may be performed as part of step Sil, and a step S32, which may be performed as part of step S12. In some embodiments, the characteristic pattern detected in step SUB (FIG. 3A) is an encoded pattern. In step S30, the encoded pattern is detected in the power signal, PS. Step S30 may be performed by analogy with step SI IB. In step S31, instruction data is determined based on the encoded pattern. In step S32, the first system 10 is operated based on the instruction data.

[0079] In step S31, the encoded pattern may be converted into a code, for example a series of binary values forming a bit pattern, and mapped to a database that associates codes with instruction data. The database may be stored in internal memory of the first system 10. A binary value ("bit") may be encoded by the second system 20 changing its power consumption to attain one of two different power values, for example either above or below a power threshold. The encoded pattern may include any number of power levels. For example, ternary values may be encoded by the power consumption being controlled to attain three different power values.

[0080] In some embodiments, the instruction data comprises an instruction for the first system 10 to perform a predefined action. As shown by steps S32A-S32B, the instruction may cause the first system 10 to start supplying the treatment fluid or to start preparing for supplying the treatment fluid. The time of receipt of the encoded pattern may thus set the supply time point or the prepare time point (cf. steps SI 1, SI 1A in FIG. 3A).

[0081] In some embodiments, the instruction data comprises configuration data for the first system 10, which applies the configuration data in accordance with step S32C. The configuration data may define settings for the first system 10. The settings may include one or more of the composition of the treatment fluid to be supplied to the second system 20, the amount of the treatment fluid to be supplied to replenish the reservoir 21, the number of exchange cycles, if an initial drain phase (IDF) is to be performed, etc. The configuration data that is given by the encoded pattern may thus replace or supplement the above-mentioned input data that the first system 10 may obtain from the back-end device 30 (FIG. 1). In some embodiments, the configuration data is indicative of the supply time point or the prepare time point for each fluid exchange cycle. Assuming that the first system 10 operates in a known time frame, the supply / prepare time point may be given in this time frame, as absolute or relative time.

[0082] FIG. 3D is a flowchart of an example method M4 performed by the second system 20 to actively control the operation of the first system 10. The method M4 may be performed by the local controller 26 of the second system 20. As shown by step S40, the method M4 may be performed during on-going therapy, while the second system 20 performs a function by use of treatment fluid, for example during a fluid exchange cycle. However, it is equally possible that the method M4 is performed before start of therapy.

[0083] The method M4 comprises a step S42 of determining instruction data for the first system 10. Examples of the instruction data are given above. In step S43, a predefined pattern is obtained for the instruction data. The predefined pattern may be obtained by use of a database that associates instruction data with predefined patterns, or codes for the predefined patterns. The database may be stored in internal memory of the second system 20. In step S44, the second system 20 is operated to embed the predefined pattern in the power consumption of the second system 20. As noted, step S44 may involve a selective activation of one or more electrically powered components of the sub-system 20a, such as a valve or a fluid pump. Additionally or alternatively, step S44 may involve selective activation of the heater 28.

[0084] As shown, the method M4 may comprise a step S41 of detecting that the second system 20 is in, or is about to enter, a predefined operating stage, where step S41 triggers steps S42-S44, and step S44 is performed to embed the predefined pattern in the power consumption at the predefined operational stage of the system. The predefined operational stage may, for example, be at or shortly before any of the time points that are indicated by numerals 0-VII in FIG. 6.

[0085] FIG. 8A is a block diagram of the local controller 11 of the first system 10 in accordance with an embodiment. The local controller 11 is configured to operate on the power signal PS to generate control signals [CS] for the sub-system 10a in the first system 10. The local controller 11 comprises a plurality of modules lla-llc. A feature extraction module 1 la is configured to process the power signal PS for extraction of a time sequence of representative features [F], such as peak values, derivatives, etc. A state determination module 1 lb is configured to determine a current operating state of the second system 20 or a switch point between operating states based on the features [F] and / or based on the power signal PS. The module 1 lb may perform the above-mentioned pattern matching or pattern recognition, for example by use of a trained machine-learning model. The module 1 lb outputs a signal S2S that indicates a detected operating state or switch point. A control logic module 11c is configured to determine, based on the signal S2S, one or more actions to be performed by the first system 10 and generate the corresponding control signals [CS].

[0086] FIG. 8B is a block diagram of a computer device, which may implement the local controller 11 of the first system 10 or the local controller 26 of the second system 20 by a combination of software and hardware circuitry, or exclusively by specific hardware circuitry. For example, the computer device may implement the modules 1 la-11c in FIG. 8A. In FIG. 8B, the computer device comprises processor circuitry 81, which may be or include a central processing unit (CPU), graphics processing unit (GPU), microcontroller, microprocessor, ASIC, FPGA, or any other specific or general processing device. The computer device may execute instructions stored in a computer memory, such as memory 82, in order to control the operation of the computer device. The computer device includes a signal interface 83 for receiving input signals, for example the power signal PS. The interface 83 may include conventional hardware for wired or wireless communication. The memory 82 may comprise one or more of a buffer, flash memory, hard drive, removable medium, volatile memory, non-volatile memory, random access memory (RAM), or another suitable data storage device. Such a memory 82 is considered a non-transitory computer-readable medium. The instructions when executed by the processor circuitry 81 may cause the computer device to perform any of the methods described herein, or part thereof. The instructions may be supplied to the computer device in the form of a computer program 84 on a computer-readable medium 85, which may be a tangible (non-transitory) product (for example magnetic medium, optical disk, read-only memory, flash memory, etc.) or a propagating signal.

[0087] In the examples described hereinabove, the first system 10 is arranged to provide treatment fluid (dialysis fluid) to the second system 20, which is configured to perform PD therapy by use of the treatment fluid. In other examples, the first system 10 is arranged to provide purified water to the second system 20, which is configured to generate treatment fluid for use in PD from the purified water, and optionally perform PD therapy. Additionally or alternatively, the first system 10 may be arranged to provide fluid for use in priming and / or disinfection and / or cleaning of the second system 20.

[0088] Although the developed technique has been described with reference to PD therapy, it is generally applicable to any combination of first and second systems where the first system is operable to supply a medical fluid to the second system. For example, the technique is equally applicable to other therapies, such as extracorporeal blood therapy (including hemodialysis, hemofiltration, hemodiafiltration), liver dialysis, etc. In these other therapies, by analogy with the examples of PD therapy, the first system 10 may be arranged to supply one or more of treatment fluid, purified water, priming fluid, disinfection fluid or cleaning fluid to the second system 20. The presented technique may also be used for supplying medical fluid to infusion devices, commonly known as infusion pumps. For example, the first system 20 may be arranged to supply an infusion solution or purified water to the second system 20, which may be an infusion device that is fluidly connected to the circulatory system of an individual.

[0089] While the subject of the present disclosure has been described in connection with what is presently considered to be the most practical embodiments, it is to be understood that the subject of the present disclosure is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0090] Further, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results.

[0091] In the following, clauses are recited to summarize some aspects and embodiments as disclosed in the foregoing.

[0092] Cl. A computer-implemented method of operating a first system (10), which is operable to supply a medical fluid to a fluid reservoir (21) of a second system (20), said method comprising: obtaining (S10) a signal indicative of a power consumption of the second system (20) as a function of time; evaluating (Sil) the signal for determination of a time point to supply the medical fluid to the fluid reservoir (21); and operating (S12), at the time point, the first system (10) to start supplying the medical fluid.

[0093] C2. The method of Cl, further comprising: operating the first system (10) to transfer electrical power to the second system (10) for the second system (20) to operate, and measuring (S10A) the electrical power transferred to the second system (20), said signal being indicative of the thus-measured electrical power.

[0094] C3. The method of Cl or C2, wherein said evaluating (Sil) comprises: detecting (S20), based on the signal, at least one operating state of the second system (20), and determining (S21) said time point based on said at least one operating state.

[0095] C4. The method of any preceding clause, wherein said evaluating (Sil) comprises: detecting (S20), based on the signal, a time sequence of operating states of the second system, and determining (S21) said time point based on the time sequence of operating states.

[0096] C5. The method of any preceding clause, wherein said evaluating (Sil) further comprises: determining (SI 1A), based on the signal, a second time point to prepare the first system (10) for supplying the medical fluid to the fluid reservoir (21), and wherein said operating (S12) comprises: operating (S12A), at the second time point, the first system (10) to start preparing for supplying the medical fluid.

[0097] C6. The method of any preceding clause, wherein said evaluating (Sil) comprises: detecting (SUB) a characteristic pattern in the signal.

[0098] C7. The method of C6, wherein the characteristic pattern is detected by pattern recognition.

[0099] C8. The method of C6 or C7, wherein said evaluating (Sil) comprises: operating a trained machine-learning model (23b) on the signal and / or signal features extracted from the signal, to detect the characteristic pattern.

[0100] C9. The method of any one of C6-C8, wherein the characteristic pattern comprises an encoded pattern.

[0101] CIO. The method of C9, wherein said evaluating (Sil) comprises: detecting (S30) the encoded pattern, and determining (S31) instruction data based on the encoded pattern, wherein said operating (S12) comprises: operating (S32) the first system based on the instruction data.

[0102] Cl 1. The method of CIO, wherein the instruction data comprises at least one of an instruction for the first system (10), or configuration data for the first system (10).

[0103] C12. The method of Cl 1, wherein the instruction causes the first system (10) to start supplying the medical fluid, or to start preparing for supplying the medical fluid.

[0104] C13. The method of Cl 1 or Cl 2, wherein the configuration data comprises at least one of an amount of the medical fluid to be supplied by the first system (10) to the fluid reservoir (21), a composition of the medical fluid, or said time point.

[0105] C14. The method of any preceding clause, wherein the medical fluid is a treatment fluid for use in peritoneal dialysis.

[0106] C15. The method of Cl 4, wherein the second system (20) comprises a dialysis machine for peritoneal dialysis, which is configured to perform one or more fluid exchange cycles, wherein a respective fluid exchange cycle comprises a sequence of a fill phase (FP), in which the treatment fluid is supplied from the fluid reservoir (21) to a peritoneal cavity, a dwell phase (DWP), in which the treatment fluid resides in the peritoneal cavity, and a drain phase (DP), in which the treatment fluid is extracted from the peritoneal cavity, and wherein the time point is in the dwell phase (DWP) or the drain phase (DP) of the respective fluid exchange cycle, and wherein the treatment fluid is supplied from the first system so that the fluid reservoir (21) contains at least a predefined amount of the treatment fluid at start of the fill phase (FP).

[0107] Cl 6. The method of Cl 5, wherein said evaluating (Sil) comprises: detecting at least one of a first switch (SW3) of the second system (20) between the fill phase (FP) and the dwell phase (DWP), or a second switch (SW4) of the second system (20) between the dwell phase (DWP) and the drain phase (DP), and determining the time point based on the first switch (SW3) and / or the second switch (SW4).

[0108] Cl 7. A computer-implemented method of operating a downstream system (20) which is operable to receive, in a fluid reservoir (21), a medical fluid from a fluid supply system (10), said method comprising: determining (S42) instruction data for the fluid supply system (10); obtaining (S43) a predefined pattern corresponding to the instruction data; and operating (S44) the downstream system (20) to embed the predefined pattern in the power consumption of the downstream system (20).

[0109] C18. A control arrangement of a first system (10), which is operable to supply a medical fluid to a fluid reservoir (21) of a second system (20), said control arrangement being configured to perform the method of any one of Cl -Cl 6.

[0110] C19. A control arrangement of a downstream system (20), which is operable to receive, from a fluid supply system (10), a medical fluid in a fluid reservoir (21), said control arrangement being configured to perform the method of C17.

[0111] C20. A computer-readable medium comprising instructions which when executed by processor circuitry (81) causes the processor circuitry (81) to perform the method of any one of C1-C17.

[0112] C21. A system, comprising: a fluid outlet (12a') for connection to a fluid reservoir (21) of a downstream system (20), a fluid supply arrangement (10a), which is operable to supply a medical fluid to the fluid reservoir (21) via the fluid outlet (12a'), and a control arrangement (11) for operating the fluid supply arrangement (10a), said control arrangement (11) being configured to: obtain a signal indicative of a power consumption of the downstream system (20) as a function of time; evaluate the signal for determination of a time point to supply the medical fluid to the fluid reservoir (21); and operate, at the time point, the fluid supply arrangement (10a) to start supplying the medical fluid.

[0113] C22. The system of C21, further comprising: a first electrical connector (15') for receiving input power, a second electrical connector (16') for providing output power to the downstream system (20), a power line arrangement (15, 16) for distributing electrical power from the first electrical connector (15') to the fluid supply arrangement (10a) and to the second electrical connector (16'), and a power meter (17) for measuring a momentary supplied power to the second electrical connector (16'), wherein the control arrangement (11) is configured to obtain the signal from the power meter (17).

[0114] C23. The system of C21 or C22, which is configured to supply the medical fluid for use as a treatment fluid in peritoneal dialysis performed by the downstream system (20). C24. The system of C23, wherein the downstream system (20) comprises a dialysis machine for peritoneal dialysis, which is configured to perform one or more fluid exchange cycles, wherein a respective fluid exchange cycle comprises a sequence of a fill phase, in which the treatment fluid is supplied from the fluid reservoir to a peritoneal cavity, a dwell phase, in which the treatment fluid resides in the peritoneal cavity, and a drain phase, in which the treatment fluid is extracted from the peritoneal cavity, and wherein the time point is in the dwell phase (DWP) or the drain phase (DP) of the respective fluid exchange cycle and the control arrangement (11) is configured to operate the fluid supply arrangement (10a) to supply the treatment fluid so that the fluid reservoir (21) contains at least a predefined amount of the treatment fluid at start of the fill phase (FP).

[0115] C25. A system comprising: a fluid inlet (24') for connection to a fluid supply system (10), a fluid reservoir (21) connected to the fluid inlet (24') to receive a medical fluid from the fluid supply system (10), a sub-system (20a) which is electrically operable to perform a function by use of the medical fluid, and a control arrangement (26) for operating the sub-system (20a), said control arrangement (26) being further configured to: determine instruction data for the fluid supply system (10); obtain a predefined pattern corresponding to the instruction data; and operate the sub-system (20a) to embed the predefined pattern in the power consumption of the system.

[0116] C26. The system of C25, wherein the instruction data is related to supplying the medical fluid by the fluid supply system (10).

[0117] C27. The system of C25 or C26, wherein the control arrangement (26) is configured to operate the sub-system (20a) to embed the predefined pattern in the power consumption by selectively activating one or more of a heater (28), a fluid pump (27a, 27b) or a valve.

[0118] C28. The system of any one of C25-C27, wherein the control arrangement (26) is configured to operate the sub-system (20a) to embed the predefined pattern in the power consumption at a predefined operational stage of the system.

Claims

22CLAIMS1. A computer-implemented method of operating a first system (10), which is operable to supply a medical fluid to a fluid reservoir (21) of a second system (20), said method comprising:obtaining (S10) a signal indicative of a power consumption of the second system (20) as a function of time,evaluating (Sil) the signal for determination of a time point to supply the medical fluid to the fluid reservoir (21), andoperating (S12), at the time point, the first system (10) to start supplying the medical fluid.

2. The method of claim 1, further comprising: operating the first system (10) to transfer electrical power to the second system (10) for the second system (20) to operate, and measuring (S10A) the electrical power transferred to the second system (20), said signal being indicative of the thus-measured electrical power.

3. The method of claim 1 or 2, wherein said evaluating (Sil) comprises: detecting (S20), based on the signal, at least one operating state of the second system (20), and determining (S21) said time point based on said at least one operating state.

4. The method of any preceding claim, wherein said evaluating (Sil) comprises: detecting (S20), based on the signal, a time sequence of operating states of the second system, and determining (S21) said time point based on the time sequence of operating states.

5. The method of any preceding claim, wherein said evaluating (Sil) further comprises: determining (SI 1A), based on the signal, a second time point to prepare the first system (10) for supplying the medical fluid to the fluid reservoir (21), and wherein said operating (S12) comprises: operating (S12A), at the second time point, the first system (10) to start preparing for supplying the medical fluid.

6. The method of any preceding claim, wherein said evaluating (Sil) comprises: detecting (SUB) a characteristic pattern in the signal.

7. The method of claim 6, wherein the characteristic pattern is detected by pattern recognition.

8. The method of claim 6 or 7, wherein said evaluating (Sil) comprises: operating a trained machine-learning model (23b) on the signal and / or signal features extracted from the signal, to detect the characteristic pattern.

9. The method of any one of claims 6-8, wherein the characteristic pattern comprises an encoded pattern.

10. The method of claim 9, wherein said evaluating (Sil) comprises: detecting (S30) the encoded pattern, and determining (S31) instruction data based on the encoded pattern, wherein said operating (S12) comprises: operating (S32) the first system based on the instruction data.

11. The method of claim 10, wherein the instruction data comprises at least one of an instruction for the first system (10), or configuration data for the first system (10).

12. The method of claim 11, wherein the instruction causes the first system (10) to start supplying the medical fluid, or to start preparing for supplying the medical fluid.

13. The method of claim 11 or 12, wherein the configuration data comprises at least one of an amount of the medical fluid to be supplied by the first system (10) to the fluid reservoir (21), a composition of the medical fluid, or said time point.

14. The method of any preceding claim, wherein the medical fluid is a treatment fluid for use in peritoneal dialysis.

15. The method of claim 14, wherein the second system (20) comprises a dialysis machine for peritoneal dialysis, which is configured to perform one or more fluid exchange cycles, wherein a respective fluid exchange cycle comprises a sequence of a fill phase (FP), in which the treatment fluid is supplied from the fluid reservoir (21) to a peritoneal cavity, a dwell phase (DWP), in which the treatment fluid resides in the peritoneal cavity, and a drain phase (DP), in which the treatment fluid is extracted from the peritoneal cavity, and wherein the time point is in the dwell phase (DWP) or the drain phase (DP) of the respective fluid exchange cycle, and wherein the treatment fluid is supplied from the first system so that the fluid reservoir (21) contains at least a predefined amount of the treatment fluid at start of the fill phase (FP).

16. The method of claim 15, wherein said evaluating (Sil) comprises: detecting at least one of a first switch (SW3) of the second system (20) between the fill phase (FP) and the dwell phase (DWP), or a second switch (SW4) of the second system (20) between the dwell phase (DWP) and the drain phase (DP), and determining the time point based on the first switch (SW3) and / or the second switch (SW4).

17. A computer-implemented method of operating a downstream system (20) which is operable to receive, in a fluid reservoir (21), a medical fluid from a fluid supply system (10), said method comprising:determining (S42) instruction data for the fluid supply system (10); obtaining (S43) a predefined pattern corresponding to the instruction data; and operating (S44) the downstream system (20) to embed the predefined pattern in the power consumption of the downstream system (20).

18. A control arrangement of a first system (10), which is operable to supply a medical fluid to a fluid reservoir (21) of a second system (20), said control arrangement being configured to perform the method of any one of claims 1-16.

19. A control arrangement of a downstream system (20), which is operable to receive, from a fluid supply system (10), a medical fluid in a fluid reservoir (21), said control arrangement being configured to perform the method of claim 17.

20. A computer-readable medium comprising instructions which when executed by processor circuitry (81) causes the processor circuitry (81) to perform the method of any one of claims 1-17.

21. A system, comprising:a fluid outlet (12a') for connection to a fluid reservoir (21) of a downstream system (20),a fluid supply arrangement (10a), which is operable to supply a medical fluid to the fluid reservoir (21) via the fluid outlet (12a'), anda control arrangement (11) for operating the fluid supply arrangement (10a), said control arrangement (11) being configured to:obtain a signal indicative of a power consumption of the downstream system (20) as a function of time,evaluate the signal for determination of a time point to supply the medical fluid to the fluid reservoir (21), and25operate, at the time point, the fluid supply arrangement (10a) to start supplying the medical fluid.

22. The system of claim 21, further comprising: a first electrical connector (15') for receiving input power, a second electrical connector (16') for providing output power to the downstream system (20), a power line arrangement (15, 16) for distributing electrical power from the first electrical connector (15') to the fluid supply arrangement (10a) and to the second electrical connector (16'), and a power meter (17) for measuring a momentary supplied power to the second electrical connector (16'), wherein the control arrangement (11) is configured to obtain the signal from the power meter (17).

23. The system of claim 21 or 22, which is configured to supply the medical fluid for use as a treatment fluid in peritoneal dialysis performed by the downstream system (20).

24. The system of claim 23, wherein the downstream system (20) comprises a dialysis machine for peritoneal dialysis, which is configured to perform one or more fluid exchange cycles, wherein a respective fluid exchange cycle comprises a sequence of a fill phase, in which the treatment fluid is supplied from the fluid reservoir to a peritoneal cavity, a dwell phase, in which the treatment fluid resides in the peritoneal cavity, and a drain phase, in which the treatment fluid is extracted from the peritoneal cavity, and wherein the time point is in the dwell phase (DWP) or the drain phase (DP) of the respective fluid exchange cycle and the control arrangement (11) is configured to operate the fluid supply arrangement (10a) to supply the treatment fluid so that the fluid reservoir (21) contains at least a predefined amount of the treatment fluid at start of the fill phase (FP).

25. A system comprising:a fluid inlet (24') for connection to a fluid supply system (10),a fluid reservoir (21) connected to the fluid inlet (24') to receive a medical fluid from the fluid supply system (10),a sub-system (20a) which is electrically operable to perform a function by use of the medical fluid, anda control arrangement (26) for operating the sub-system (20a), said control arrangement (26) being further configured to:determine instruction data for the fluid supply system (10);obtain a predefined pattern corresponding to the instruction data; andoperate the sub-system (20a) to embed the predefined pattern in the power consumption of the system.

26. The system of claim 25, wherein the instruction data is related to supplying the medical fluid by the fluid supply system (10).

27. The system of claim 25 or 26, wherein the control arrangement (26) is configured to operate the sub-system (20a) to embed the predefined pattern in the power consumption by selectively activating one or more of a heater (28), a fluid pump (27a, 27b) or a valve.

28. The system of any one of claims 25-27, wherein the control arrangement (26) is configured to operate the sub-system (20a) to embed the predefined pattern in the power consumption at a predefined operational stage of the system.

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