Devices for handling leakage currents in dialysis therapy

Abstract

An apparatus (100) for use in dialysis therapy, said apparatus comprising: a fluid handling unit (110) configured to interact with fluid communicating between a first fluid interface (131) and a second fluid interface (132); 5 power circuitry (120) connected to the fluid handling unit, said power circuitry including: a primary power inlet (121) connected via a primary circuit to the fluid handling unit; a secondary power inlet (122) connected via a secondary circuit to the fluid 0 handling unit; and a relay circuit (123) configured to disconnect the primary circuit based on voltage being received in the secondary power inlet.

Description

[0001] DEVICES FOR HANDLING LEAKAGE CURRENTS IN DIALYSIS

[0002] THERAPY

[0003] Technical Field

[0004] The present disclosure relates generally to dialysis therapy, and in particular to devices configured for managing leakage current limitations in connection with dialysis therapy.

[0005] Background Art

[0006] Dialysis therapy is undertaken to replace or supplement the normal blood-filtering function of the kidneys. It is used when the kidneys are not working well, which is known as kidney failure and includes acute kidney injury (AKI) and chronic kidney disease (CKD). Dialysis therapy involves removal of water from the body of the patient suffering from kidney failure, as well as exchange of solutes with the patient's blood. One example of dialysis therapy is extracorporeal (EC) blood therapy, in which blood is circulated outside of the patient and interfaced with one or more treatment fluids. Modalities of extracorporeal blood therapy include hemodialysis (HD), hemofiltration (HF) and hemodiafiltration (HDF). Another example of dialysis therapy is peritoneal dialysis (PD), in which a treatment fluid is infused into the peritoneal cavity of the patient to interface with the blood of the patient through the peritoneal membrane.

[0007] Treatment fluids used in HD and PD are commonly known as dialysis fluids. In HF, the treatment fluid is known as replacement fluid, since it is infused into the blood of the patient to replace fluid removed during therapy. In HDF, both dialysis fluid and replacement fluid are used.

[0008] Dialysis therapy may be automated by use of machines, i.e. electrical equipment. Such electrical equipment produces leakage currents. There are standards for safety and performance of medical electrical equipment. One such standard is IEC60601, which defines maximum leakage currents allowed in electrical medical equipment to reduce the risk of electrical shock based on type of applied part (AP) and based on type of leakage current. The AP is a component of the medical equipment that comes into contact with the patient during normal operation. For dialysis therapy, IEC60601-2-39:2018 applies to the basic safety and essential performance of medical electrical equipment for PD. It defines that PD equipment needs to be Class II BF (Body Floating). Class II BF require a floating patient ground and has a maximum allowed patient leakage current of I OOp A for NC and 500p A for SFC. Here, NC (Normal Condition) refers to the situation when leakage current flows from the AP via the patient to earth (grounded patient), and SFC (Single Fault Condition) refers to the situation when a component or isolation barrier breaks, causing the patient to be exposed to a potentially increased leakage current. Electrical equipment for extracorporeal blood therapy that is not connected to protective Earth needs to be Class II CF (Cardiac Floating). Class II CF requires a floating patient ground and has a maximum allowed patient leakage current of I Op A for NC and 50p A for SFC.

[0009] Although medical devices configured for use in dialysis therapy are designed to meet various criteria or limits for leakage currents, additional challenges may occur in modes of operation where a plurality of medical devices are concurrently used in connection with the patient.

[0010] Summary

[0011] It is an objective to at least partly overcome one or more limitations of the prior art.

[0012] One objective is to provide a technical solution for adhering to leakage current requirements in dialysis therapy.

[0013] A further objective is to provide a technical solution for employing dialysis therapy comprising a plurality of electrically powered devices.

[0014] One or more of these objectives, as well as further objectives that may appear from the description below, are at least partly achieved by an apparatus for use in dialysis therapy, and a system including such an apparatus, as outlined in the independent claims.

[0015] According to a first aspect, the proposed solution provides A apparatus for use in dialysis therapy, said apparatus comprising: a fluid handling unit configured to interact with fluid communicating between a first fluid interface and a second fluid interface; power circuitry connected to the fluid handling unit, said power circuitry including: a primary power inlet connected via a primary circuit to the fluid handling unit; a secondary power inlet connected via a secondary circuit to the fluid handling unit; and a relay circuit configured to disconnect the primary circuit based on voltage being received in the secondary power inlet.

[0016] According to a second aspect, the proposed solution provides a system for dialysis therapy, comprising the apparatus and a fluid supply device, wherein fluid supply device comprises: a power outlet connectable to the secondary power inlet of the apparatus, and a fluid port connectable to supply a dialysis fluid to the first fluid interface of the apparatus, wherein, upon the power outlet being connected to the secondary power inlet, the fluid handling unit is configured to be powered from the fluid supply device.

[0017] The proposed solution according to these aspects provide for a technical system for dialysis, wherein capability is obtained of electrically powering the apparatus from another device involved in the dialysis therapy, such as the fluid supply device, using the secondary power inlet. This way, power circuitry and other units in the apparatus which are otherwise powered through the primary power inlet connected to e.g., a mains outlet upon standalone operation of the apparatus, can be powered by lower voltage, such as a direct current (DC) voltage from the other device. This way, leakage current caused by the apparatus may be mitigated.

[0018] In some embodiments, wherein the relay circuit is configured to be normally closed, NC, to maintain galvanic connection between the primary power inlet and the fluid handling unit.

[0019] In some embodiments, the relay circuit is configured to obtain galvanic separation of at least 5 mm between the primary power inlet and the fluid handling unit upon disconnection. In some embodiments, the fluid handling unit comprises a fluid pump unit, connected to obtain power either from the primary circuit or the secondary circuit, based on connection state of the relay circuit.

[0020] In some embodiments, the power circuitry comprises a power supply device in the primary circuit, configured to convert voltage received from the primary power inlet and to supply converted voltage to the fluid handling unit, wherein the relay circuit is configured to disconnect the power supply device from the primary power inlet.

[0021] In some embodiments, the fluid handling unit comprises a heater element connected via the primary circuit, wherein the heater element is configured to heat fluid passed from the first fluid interface to the second fluid interface, wherein the relay circuit is configured to disconnect the heater element from the primary power inlet.

[0022] In some embodiments, the fluid handling unit comprises a temperature sensor configured to sense temperature of the fluid passed from the first fluid interface to the second fluid interface; wherein, upon the heater circuitry being disconnected, the apparatus is configured to transmit temperature control information based on sensed temperature to a fluid supply device connected to the first fluid interface.

[0023] In some embodiments, the first fluid interface is connectable to receive a dialysis fluid and to dispose fluid to drain, wherein the second fluid interface is connectable to a patient.

[0024] In some embodiments, the primary power inlet is configured to be connected to a mains outlet.

[0025] In some embodiments, the primary power inlet is configured to receive high voltage of 100-240 VAC.

[0026] In some embodiments, the secondary power inlet is configured to receive low voltage of 20-30 VDC and ground connection.

[0027] In some embodiments, the apparatus further comprises: a user interface, wherein the apparatus is configured to output information on the user interface indicative of connection or disconnection of the primary power inlet.

[0028] In some embodiments, the apparatus is configured to output an alert message responsive to detecting that voltage is obtained in the secondary power inlet while the heater element or the power supply device is detected to receive power. In some embodiments, the apparatus is configured to provide functionality as a cycler.

[0029] In some embodiments related to the system according to the second aspect, the fluid supply device comprises a control circuit, configured to selectively switch supply voltage on or off to the power outlet.

[0030] In some embodiments, the fluid supply device comprises: a control interface connectable to receive control information from the apparatus.

[0031] In some embodiments, the fluid supply device comprises: a fluid heater, configured to control temperature of the fluid supplied to the apparatus based on control information obtained from the apparatus.

[0032] In some embodiments, the fluid supply device is configured to switch supply voltage on or off to the power outlet based on control information obtained from the apparatus.

[0033] In some embodiments, the fluid supply device is configured to switch supply voltage on to the power outlet based on the control information indicating that a patient is connected to the apparatus.

[0034] Still other objectives, aspects, embodiments, and technical effects, as well as features and advantages may appear from the following detailed description, from the attached claims as well as from the drawings.

[0035] Brief Description of the Drawings

[0036] Figs 1A-1B are schematic views of example dialysis systems connected to a patient.

[0037] Fig. 2A schematically shows an apparatus for use in dialysis therapy, according to an example.

[0038] Fig. 2B schematically illustrates exemplary configurations of primary and secondary power inlets of the apparatus of Fig. 2A.

[0039] Fig. 3 schematically illustrates various details which may be included in the apparatus of Fig. 2A in different embodiments.

[0040] Fig. 4 schematically illustrates a system for dialysis therapy according to various embodiments, wherein the system comprises the apparatus of Fig. 2A and a fluid supply device connected to the apparatus. Detailed Description

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] As used herein, "dialysis therapy" refers to any therapy that replaces or supplements the renal function of a patient by use of a medical fluid. Dialysis therapy includes, without limitation, extracorporeal (EC) blood therapy and peritoneal dialysis (PD) therapy.

[0047] As used herein, "treatment fluid" refers to any fluid that is consumed as a result of dialysis therapy. Treatment fluid includes, without limitation, dialysis fluid for infusion into the peritoneal cavity during PD therapy, dialysis fluid for supply to a dialyzer during EC blood therapy, and replacement fluid and substitution fluid for infusion into blood during EC blood therapy.

[0048] Like reference signs refer to like elements throughout.

[0049] The present disclosure relates to a technique of handling leakage currents in relation to dialysis therapy performed by electric machines. The technique is applicable to both peritoneal dialysis (PD) therapy and extracorporeal (EC) blood therapy. For context only, systems for PD therapy and EC blood therapy will be briefly discussed with reference to Figs 1A-1B.

[0050] Fig. 1A is a generic overview of a system 10, also referred to herein as a dialysis system, for PD therapy. The dialysis system 10 is fluidly connected to the peritoneal cavity PC of a patient P. As indicated by a double-ended arrow, the dialysis system 10 is operable to convey fresh dialysis fluid into PC and to receive spent dialysis fluid from PC on a fluid path 11. The fluid path 11 may be defined by tubing that connects to an implanted catheter (not shown) in fluid communication with the peritoneal cavity PC. A drain line 13 is connected to the dialysis system 10 for conveying the spent dialysis fluid to a drain 25. In the illustrated example, the dialysis system 10 comprises an automated therapy sub-system 30 that performs the PD therapy. PD therapy is typically implemented as daily treatment sessions, each comprising a number of fluid exchange cycles. The respective fluid exchange cycle may include a fill phase, a dwell phase and a drain phase, performed in sequence. In the fill phase, the fresh dialysis fluid is supplied to PC on fluid path 11. In the dwell phase, the dialysis fluid resides in PC. In the drain phase, the spent dialysis fluid is extracted from PC on fluid path 11.

[0051] The therapy sub-system 100 may comprise one or more electrically controlled machines and may be implemented to provide different levels of functionality. In a first implementation, the therapy sub-system 100 may include a therapy device which is operable to control the flow of dialysis fluid to and from the PC, and the sub-system 100 receives pre-made dialysis fluid from a source 20 on a supply path 12. In PD therapy, the therapy device is commonly known as a "cycler". In a second implementation, the therapy sub-system 100 includes the cycler and a mixing device that is configured to generate the dialysis fluid for the cycler by mixing one or more concentrates with purified water, which is received from the source 20. In a third implementation, the therapy sub-system 100 includes the cycler, the mixing device and a water purification device that is configured to generate the purified water based on source water, which is received from the source 20.

[0052] Fig. IB is a generic overview of a dialysis system 10 for EC blood therapy. The dialysis system 10 is fluidly connected to the vascular system of a patient P on a fluid path. In the illustrated example, the fluid path is defined by tubing 11 A for blood extraction and tubing 1 IB for blood return. As indicated by arrows, the dialysis system 10 is operable to draw blood from the patient P through tubing 11 A, process the blood, and return the processed blood to the patient through tubing 1 IB. The tubing 11A, 1 IB is connected to an access device (for example a catheter, graph or fistula, not shown) in fluid communication with the vascular system of the patient P. The dialysis system 10 may be configured to process the blood by any form of EC blood therapy, such as HD, HF or HDF. In HD and HDF, dialysis fluid is interfaced with the blood of the patient in a filtration unit ("dialyzer"), resulting in spent dialysis fluid. A drain line 13 is connected to the dialysis system 10 for conveying the spent dialysis fluid to a drain 25. In the illustrated example, the dialysis system 10 comprises an automated therapy subsystem 100 that performs the EC blood therapy. Like in Fig. 1A, the therapy sub-system 100 may comprise one or more electrically controlled machines and may be implemented to provide different levels of functionality. The first, second and third implementation examples are equally applicable to the therapy sub-system 100 in the dialysis system 10 for EC blood therapy.

[0053] It may be acknowledged that in the field of medical therapy, such as dialysis, a plurality of electrically powered machines or devices may be employed. Specifically, a plurality of machines may be connected in a medical system (ME). The medical system has to meet leakage current requirements in order to be certified for use in connection with a patient which is fluidly connected to the system (i.e., connected to provide fluid communication between the system and the patient). By way of example, this may be the case where a first device is configured to supply and potentially produce dialysis fluid, whereas a second device is configured to handle fluid delivery to and from the patent. In another example, a first device may be configured to handle blood or fluid delivery to and from the patent, whereas second device is configured to provide heat blood or fluid extracorporeally prior to supply to the patient.

[0054] In situations where two or more medical devices connects to one patient the total leakage current still must fulfil leakage current requirement, such as those provided in the medical standard EN60601. For an apparatus operating as a PD dialysis cycler these requirements include a limit set to < lOOp A NC and <500p A SFC. So, for example if the apparatus is connected to the patient concurrently with a further device, such as a fluid supply device connected to the apparatus, the total NC patient leakage current still need to be less than 100 p A. Such a patient leakage current is very challenging to reach, both from a technical aspect and a cost aspect, when both devices have components that couple directly into the fluid path.

[0055] In various examples, the proposed solution relates to a system 10 which comprises durable flow paths, where one or more components of the system (such as vents, heaters, detectors, etc.) are directly in contact with the fluid in the flow path. The durable flow path may thus comprise non-disposable fluid lines, e.g. internal fluid paths, in the system 10, such as ducts, pipes or tubes which typically are not exchanged during normal use of the system 10. An advantage of the system 10 being configured with a durable fluid line, or fluid circuit, is that the fluid line is reusable. This reduces the efforts on the patient when preparing the system 10 for use as there is no need to set up disposable lines and / or dress the system 10 with fluid flow paths. Further, less material waste is generated. However, in contrast to other systems which use disposable flow paths, e.g., in PD therapy, where the disposable flow path acts as an insulator between the machine and the fluid, particular care must be taken in the system 10 to manage leakage currents due to the connection between the components and the fluid in the fluid path.

[0056] Based on the objective of mitigating these challenges, the proposed solution involves an apparatus and a system, which will be described with reference to the drawings. Fig. 2A shows an apparatus 100 for use in dialysis therapy, according to an example of the proposed solution. The apparatus may correspond to the therapy subsystem 100 shown in Fig. 1A or IB.

[0057] The apparatus comprises a fluid handling unit 110 configured to interact with fluid communicating between a first fluid interface 131 and a second fluid interface 132. In this context, interacting with the fluid may include having electrically powered components which interact with the fluid, and which components are configured to come in galvanic or capacitive contact with the fluid.

[0058] The fluid interfaces 131, 132 may comprise connectors for external conduits, such as tubes, hoses, pipes, or similar. The apparatus 100 may be configured to handle fluid passing from the first interface 131 to the second interface 132, or vice versa, or fluid communicated in both ways.

[0059] The apparatus 100 further comprises power circuitry 120 connected to the fluid handling unit 110. This may involve providing electric power to one or more components of the fluid handling device 110.

[0060] The power circuitry 120 comprises a primary power inlet 121 of the apparatus 100, wherein the primary power inlet 121 is connected via a primary circuit to the fluid handling unit 110.

[0061] The power circuitry 120 further comprises a secondary power inlet 122 of the apparatus 100, wherein the secondary power inlet 122 is connected via a secondary circuit to the fluid handling unit 110.

[0062] The power circuitry 120 further comprises a relay circuit 123 configured to disconnect the primary circuit, i.e., the connection between the primary power inlet 121 and the fluid handling unit 110, based on voltage being received in the secondary power inlet 122. In the drawing, a diode symbol is indicated in the relay circuit. This illustrates that the relay circuit 123 is only connected to receive power from the secondary power inlet 122, not from the primary power inlet 121 via the primary circuit.

[0063] By this configuration, the apparatus 100 is configured to operate either by using input electric power from the primary power inlet 121 or from the secondary power inlet 122. Specifically, this configuration provides the capability of powering the apparatus 100 from another device concurrently involved in therapy with a patient.

[0064] In some examples, the primary power inlet 121 is configured to be connected to a mains outlet, and may be configured to receive high voltage of 100-240 VAC. This way, the primary power inlet 121 may inter alia be used when the apparatus 100 is used for standalone operation. Further features and alternative configurations associated with the configuration of the primary power inlet 121 are discussed below with reference to Fig. 2B.

[0065] The secondary power inlet may be configured to receive comparatively lower voltage, such as a direct current (DC), e.g., a low voltage of 20-30 VDC and ground connection. This allows for concurrent operation with another device which may provide the low voltage to the apparatus 100. In this configuration, there will be no added leakage current caused by components powered by high voltage in the apparatus 100. Further features and alternative configurations associated with the configuration of the secondary power inlet 122 are discussed below with reference to Fig. 2B.

[0066] Fig. 2B schematically illustrates that the primary power inlet 121 and the secondary power inlet 122 may have different configurations, according to some embodiments of the proposed solution.

[0067] The primary power inlet 121 and the secondary power inlet 122 of the apparatus 100 may comprise different power sockets, such as different machine-mounted power sockets. A power socket is a device that provides a safe and convenient way to connect electrical devices to a power source. It may be a standardized receptacle that accepts a plug, such as a plug of a power cable. A machine-mounted power socket, also known as a machine-mounted receptacle or machine-mounted connector, is a type of power socket that is permanently attached to a machine or equipment, such as the apparatus 100. The machine-mounted power socket is designed to provide a power connection point for the apparatus 100, allowing it to be powered from a nearby power source. The machine-mounted power socket may be mounted in various ways, such as on a frame, a panel, or a cable of the apparatus 100.

[0068] In some examples, the primary power inlet 121 comprises a first power socket 1211 whereas the secondary power inlet 122 comprises a second power socket 1221, wherein the first power socket 1211 has a configuration which is different from a configuration of the second power socket 1221.

[0069] In some examples, the first power socket 1211 may be configured to mate with an associated primary type power plug (not shown) for receiving power from a primary type power source. The primary type power source may be an alternating current power source, such as a mains outlet. The first power socket 1211 may thus be a mains socket.

[0070] The first power socket 1211 may have a first physical configuration.

[0071] The first physical configuration may comprise a first recessed portion for accepting the associated primary type power plug.

[0072] The first physical configuration may comprise a set of poles 1212 of a first layout.

[0073] In some examples, the second power socket 1221 may be configured to mate with an associated secondary type power plug (not shown) for receiving power from a secondary type power source.

[0074] The secondary type power source may be a DC power source, such as a voltage transformer. As will be explained, the secondary type power source may in some examples be a fluid supply device 200 used in combination with the apparatus 100.

[0075] The second power socket 1221 may be DC voltage socket.

[0076] The second power socket 1221 may have a second physical configuration.

[0077] The second physical configuration may comprise a second recessed portion for accepting the associated secondary type power plug.

[0078] The second physical configuration may comprise a set of poles 1222 of a second layout.

[0079] In some examples, the second layout of poles 1222 of the secondary power inlet 122 is different from the first layout of poles 1212 of the primary power inlet 121.

[0080] In some examples, the first physical configuration of the first power socket 1211 is different from the second physical configuration of the second power socket 1221, to prevent or counteract wrongful connection of power sources to the primary power inlet 121 or secondary power inlet 122. This is indicated in the drawing, by way of example, by means of the first power socket 121 lhaving a substantially circular configuration, whereas the secondary power socket 1221 has a substantially rectangular configuration.

[0081] In some examples, the relay circuit 123 is configured to be normally closed (NC), to maintain galvanic connection between the primary power inlet 121 and the fluid handling unit 110. This configuration provides for convenient operation of the apparatus 100 as a standalone machine and ensures that full capability of the apparatus 100 is the default setting. Opening, or activation, of the relay circuit 123 entails that components of the fluid handling device which are configured to use power obtained from the primary power inlet 121 are incapacitated, which may lead to restricted operation capability of the apparatus 100.

[0082] In some examples, the relay circuit 123 is configured to obtain galvanic separation of at least 5 mm between the primary power inlet and the fluid handling unit upon disconnection. This allows for proper disconnection to counteract both conductive and capacitive coupling between the primary power inlet 121 and the fluid handling unit 110, even when the primary power inlet 121 is connected to a high voltage power source such as a mains outlet.

[0083] An example of the apparatus 100 is shown in Fig. 3, in which further details included in various embodiments are depicted. Initially, various details of the power supply circuitry 120 will be described.

[0084] The primary power inlet 121 may include poles, or connectors, 1212 for at least two leads, such as at least two phases or one phase and zero, and may further comprise a ground connection. The relay circuit 123 is configured to disconnect (or connect) both / all leads of the primary power inlet 121.

[0085] The power supply circuitry 120 comprises a power supply device 124, connected in the primary circuit between the primary power inlet 121 and the fluid handling unit 110. The power supply device 124 may comprise more than one power supply function, as will be described below.

[0086] In some examples, the power supply device 124 comprises a power supply unit 125, which is configured to supply power to various components of the fluid handling unit 110 based on electric power received through the primary power inlet 121. The power supply unit 125 may comprise a power or voltage converter, configured to convert high voltage received from the primary power inlet 121 to lower supply voltage connected to drive various components of the fluid handling unit 110, such as to a fixed lower direct voltage, e.g. 24VDC. For the sake of visibility, supply voltage leads are identified with a double line in the drawing. As noted, the supply voltage is not connected to trigger the relay circuit, as indicated by the diode symbol in Fig. 3. In other words, the primary circuit is not connected to trigger the relay circuit 123.

[0087] In some examples, the power supply device 124 further comprises a separate heater board 126, which is configured to supply power to a heater element of the fluid handling unit 110 based on electric power received through the primary power inlet 121. The heater board 126 may comprise a voltage converter, configured to convert high voltage received from the primary power inlet 121 to a lower heater element drive voltage, such as a variable voltage from 0 to 110VDC to control power supplied to a heater element 111 configured to heat fluid in the fluid handling unit. In other examples, the heater element in the fluid handling unit is connected to be powered from the power supply unit 125.

[0088] By means of activating the relay circuit 123 to disconnect the primary power inlet 121, any leakage current otherwise caused by the power supply unit 125 is cancelled, as well as any leakage current otherwise caused by the heater board 126 and its connected heater element, where applicable.

[0089] In the shown example, a primary circuit to the fluid handling unit 110 runs from the primary power inlet 121 through the power supply unit 125, and optionally also through the heater board 126. A secondary circuit to the fluid handling unit 110 runs from the secondary power inlet 122 and bypasses the power supply device 124, i.e., the power supply unit 125 and also the heater board 126 where this is included. In some embodiments, the secondary circuit thus does not provide power to the heater element 111 from the secondary power inlet 122. The secondary power inlet 122 may, in some examples, be configured to receive a cable configured to supply a voltage corresponding to the supply voltage delivered by the power supply unit 125.

[0090] Below, various related to the fluid handling unit 110 will be described.

[0091] The fluid handling device 110 may comprise one or more components, of which one or more are configured to interact with fluid passed between the first 131 and second 132 interfaces of the apparatus 100. For this purpose, at least one conduit 133 is arranged for communicating fluid between said interfaces 131, 132, wherein the at least one component of the fluid handling unit 110 is configured to interact with the fluid at said conduit 133. The conduit 133 may comprise one or more pipes, tubes, chambers or channels in the fluid handling unit 110. In some embodiments, the first fluid interface 131 is connectable to receive a dialysis fluid and to dispose fluid to drain 25, wherein the second fluid interface 132 is connectable to a patient P. In this context, the apparatus 100 may at least partly comprise a durable fluid line, or fluid circuit, in which various components of the apparatus 100 are arranged to come in direct contact with the fluid.

[0092] For the sake of simplicity, a single control unit 114 is shown in the example of Fig. 3, which is powered from the power supply circuitry 120. The control unit 114 is connected to a number of different components, to supply drive voltage and optionally to provide control communication to said components. In alternative embodiments, a plurality of different control units may be employed. In the drawing, power supply connection is indicated by full lines, whereas control and data lines are indicated by dashed lines.

[0093] The control unit 114 comprises logic circuitry configured to communicate or more of power, data, and control signals, to the connected components. The logic circuitry may include a processing device, including one or multiple processors, microprocessors, data processors, co-processors, and / or some other type of component that interprets and / or executes instructions and / or data. The processing device may be implemented as hardware (e.g., a microprocessor, etc.) or a combination of hardware and software (e.g., a system-on-chip (SoC), an application-specific integrated circuit (ASIC), etc.). The processing device may be configured to perform one or multiple operations based on an operating system and / or various applications or programs. The logic circuitry may further include memory storage, which may include one or multiple memories and / or one or multiple other types of storage mediums. For example, the memory storage may include a random-access memory (RAM), a dynamic random-access memory (DRAM), a cache, a read only memory (ROM), a programmable read only memory (PROM), flash memory, and / or some other type of memory. The memory storage may include a hard disk (e.g., a magnetic disk, an optical disk, a magneto-optic disk, a solid-state disk, etc.). The memory storage is configured for holding computer program code, which may be executed by the processing device, wherein the logic circuitry is configured to control the apparatus 100 to carry out any of the method steps as provided herein. Software defined by said computer program code may include an application or a program that provides a function and / or a process. The software may include device firmware, an operating system (OS), or a variety of applications that may execute in the logic circuitry.

[0094] In some examples, the fluid handling unit 110 comprises a fluid pump unit 112. The fluid pump unit 112 may be configured to drive fluid between the first fluid interface 131 and the second fluid interface 132, either in one direction or in both directions. The fluid pump unit 112 may further comprise one or more electrically controlled valves. In some examples, the fluid pump unit 112 is configured to operate in contact with the fluid in the conduit 133, thereby subjecting the fluid to the risk of a leakage current in the apparatus 100. The fluid pump unit 112 is connected to obtain power either from the primary circuit, i.e., from the primary power inlet 121, or the secondary circuit, i.e., from the secondary power inlet 122, based on connection state of the relay circuit 123. In the shown example, the fluid pump unit 112 is connected to receive power via the control unit 114.

[0095] In some examples, the fluid handling unit 110 comprises a heater element 111 configured to heat fluid passed from the first fluid interface 131 to the second fluid interface 132. In some examples, the heater element 111 is configured to operate in contact with the fluid in the conduit 133, thereby subjecting the fluid to the risk of a leakage current in the apparatus 100. In the shown example, the heater element 111 is configured to receive power obtained from the primary power inlet 121, wherein the relay circuit 123 is configured to disconnect the heater element 111 from the primary power inlet. In such an embodiment, the heater element 111 is inactivated upon the relay circuit breaking the primary circuit. In an alternative embodiment, the heater element may obtain power obtained from the secondary power inlet 122, via the secondary circuit, upon the relay circuit 123 breaking the primary circuit.

[0096] The fluid handling unit 110 may comprise one or more sensors. In some examples, the fluid handling unit 110 comprises a temperature sensor 113 configured to sense temperature of the fluid passed in the conduit 133, such as from the first fluid interface 131 to the second fluid interface 132. Input from the temperature sensor 113 may be used for controlling heater element 111, i.e., typically the amount of heat supplied by the heater element 111, to obtain a suitable target temperature in the fluid. This may be accomplished by the control unit 114, and in alternative embodiments by the heater board 126.

[0097] In some examples, the apparatus 100 may further comprise a user interface 115. The apparatus 100 may be configured to output information on the user interface 115 related to operation of the apparatus, including guide information to an operator of the apparatus 100, such as the patient P. The user interface may comprise one or more of a display, a speaker, and user input in the form of keys and / or touch screen functionality.

[0098] In some examples, the apparatus 100 may further comprise a communication interface 116, usable for conveying control signals and optionally measurement data between the apparatus 100 and a further device, such as a connected fluid supply device. The communication interface 116 may be operated under control of the control unit 114. In various examples, the communication interface 116 is configured to provide wired and / or wireless connection, such as a Universal Serial Bus (USB) and Ethernet, Wi-Fi, Bluetooth, or other.

[0099] As noted, the relay circuit 123 in the apparatus serves to disconnect the primary circuit, based on voltage being received in the secondary power inlet 122. In some examples, the relay circuit 123 is configured such that voltage, exceeding a certain activation voltage level, received in the secondary power inlet 122 will automatically disconnect the primary circuit. In other examples, the relay circuit 123 may comprise an input from a control circuit 127. In such an embodiment, the relay circuit 123 may be configured to disconnect the primary circuit based on voltage being received in the secondary power inlet 122 responsive to a disconnect signal additionally being received through the control circuit 127. Various alternatives in this context are further described below.

[0100] Fig. 4 schematically illustrates a system 10 for dialysis therapy, comprising the apparatus 100 and a fluid supply device 200 being connected to the apparatus 100. Various aspects related to the apparatus 100 and to the system 10 are described below, with reference to examples and embodiments. The use scenario of the apparatus 100 in the context of the system 10 will also emphasize various benefits of the configuration of the apparatus 100 as such.

[0101] In Fig. 4, the schematic drawing of Fig. 2A is used for the apparatus 100. However, it should be understood that the apparatus 100 used in the system 10 may in some embodiments comprise one or more further features, such as those outlined with reference to Fig. 3. Reference signs used in Figs 2A and 3 will therefore also be used when describing the subject matter of the system as shown in Fig. 4.

[0102] The fluid supply device 200 is connected to the apparatus 100 in the system 10 and comprises at least a power outlet 203 connectable to the secondary power inlet 122 of the apparatus, and a fluid port 208 connectable to supply a dialysis fluid to the first fluid interface 131 of the apparatus, e.g. by a tube 401. Specifically, upon the power outlet 203 being connected to the secondary power inlet 122, the fluid handling unit 110 is configured to be powered from the fluid supply device 200. For this purpose, a cable 402 may be connected between the power outlet 203 and the secondary power inlet 122. As described with reference to the apparatus 100 in the foregoing, voltage supply (from the fluid supply device 200) to the secondary power inlet 122 is used at least one trigger for the relay circuit 123 to disconnect the primary circuit in the apparatus, such that any high voltage outlet (e.g., mains) connected to the primary power inlet is cut off in the power circuitry 120.

[0103] Various aspects of the fluid supply device 200 and its function in the system 10 will be described below.

[0104] In some examples, the fluid supply device 200 is configured to process dialysis fluid, for use in the apparatus 100. In this context, processing dialysis fluid may comprise one or more of producing dialysis fluid, cleaning water for producing the dialysis fluid, and mixing one or more concentrates with water to obtain dialysis fluid. A fluid inlet 205 is connectable to a fluid source 20, such as a water tap or tank.

[0105] In some examples, the fluid supply device 200 comprises a dialysis fluid processing unit 209, which may be configured to process the obtained water in one or more ways. This may include cleaning (e.g., filtering), adding fluid components (e.g., electrolytes etc.), and mixing, to produce a dialysis fluid, also referred to as a treatment fluid TF.

[0106] The dialysis fluid processing unit 209 may be configured to generate product water PW from source water SW, which may be tap water or any other water of insufficient (or at least unverified) purity and / or sterility for use in dialysis therapy. In this context, a water purification device may be arranged to receive SW and to provide PW to a mixing device in the fluid processing unit 209. Water purification devices are well-known in the art and may involve, in any combination, active carbon filtration, ultrafiltration, membrane filtration, ion exchange, electrodeionization, dechlorination, disinfection, softening, etc. One commonly used membrane filtration technique for water purification is reverse osmosis (RO), in which an RO membrane is used to separate ions, molecules and larger particles from water. Reverse osmosis inherently generates a flow of so-called reject water, which has a lower purity than the product water. In some implementations, the reject water, or part thereof, is discarded to drain 25.

[0107] The mixing device of the dialysis fluid processing unit 209 may may be configured to generate the TF by mixing product water PW with one or more concentrates Cx. The respective concentrate may be in liquid form or in the form of a powder or granules. The mixing device is arranged to receive the PW to provide TF to a a fluid supply unit 211, for subsequent delivery to the apparatus 100 via fluid connector 208. The fluid supply unit 211 may in some examples be included in the mixing device of the fluid processing unit 209.

[0108] In some examples, the fluid supply device comprises a fluid heater 210, configured to control temperature of the fluid obtained from the fluid processing unit 209 which is subsequently supplied to the apparatus 100.

[0109] In various examples, the fluid supply device 200 at least partly comprise a durable fluid line, or fluid circuit, in which fluid is arranged to come in direct contact with various components, such as the fluid processing unit 209 (e.g., the mixing device) and / or the fluid heater 210.

[0110] The fluid supply unit 211 is connected to the fluid port 208. The fluid supply unit 211 may comprise one or more of a pump, valves, and sensors for detection of various fluid parameters, such as flow and temperature.

[0111] In the system 10, the fluid supply device 200 is thus configured to supply dialysis fluid TF to the apparatus, and to receive fluid from the apparatus 100 and dispose thereof to drain 25 via a fluid outlet 206. In combination, the fluid supply device 200 and the apparatus may be operated as a system 10 for PD therapy, where a connection 11 is provided between the patient and the apparatus 100, as generally described with reference to Fig. 1C.

[0112] The fluid supply device 200 may comprise a control circuit 201, which takes electric power input from an inlet 202, connectable to mains to receive high voltage. The control circuit 201 may be configured to power and manage control signaling with various components of the fluid supply device 200, such as the dialysis fluid processing unit 209, the fluid heater 210, and the fluid supply unit 211.

[0113] Although not described in detail herein, the control circuit 201 may thus comprise a voltage converter for providing suitable drive voltage to the components based on the received high voltage.

[0114] The control circuit 201 may further comprise a communication unit, configured to convey control information in communication with, at least, the apparatus 100, over a communication path 403. In various examples, the communication unit may thus comprise a communication interface 212 configured to provide wired and / or wireless connection, such as a Universal Serial Bus (USB) and Ethernet, Wi-Fi, Bluetooth, or other. The control circuit 201 may further comprise logic circuitry configured to communicate or more of power, data, and control signals, to the connected components. The logic circuitry may include a processing device, including one or multiple processors, microprocessors, data processors, co-processors, and / or some other type of component that interprets and / or executes instructions and / or data. The processing device may be implemented as hardware (e.g., a microprocessor, etc.) or a combination of hardware and software (e.g., a system-on-chip (SoC), an application-specific integrated circuit (ASIC), etc.). The processing device may be configured to perform one or multiple operations based on an operating system and / or various applications or programs. The logic circuitry may further include memory storage, which may include one or multiple memories and / or one or multiple other types of storage mediums. For example, the memory storage may include a random-access memory (RAM), a dynamic random-access memory (DRAM), a cache, a read only memory (ROM), a programmable read only memory (PROM), flash memory, and / or some other type of memory. The memory storage may include a hard disk (e.g., a magnetic disk, an optical disk, a magneto-optic disk, a solid-state disk, etc.). The memory storage is configured for holding computer program code, which may be executed by the processing device, wherein the logic circuitry is configured to control the fluid supply device 200 to carry out any of the method steps as provided herein. Software defined by said computer program code may include an application or a program that provides a function and / or a process. The software may include device firmware, an operating system (OS), or a variety of applications that may execute in the logic circuitry.

[0115] In some examples, the control circuit 201 is configured to selectively switch supply voltage on or off to the power outlet 203. This may be obtained by operating a switch 204. On and Off control of the switch may be controlled, by the control circuit 201, based on control information obtained from the apparatus 100 via the communication interface 212. In one example, the fluid supply device 200 is configured to switch supply voltage on to the power outlet 203 based on control information received from the apparatus, indicating that a patient is connected to the apparatus. Indication of connection of a patient may, in various embodiments, be obtained in the apparatus based on input using the user interface 115 or based on a sensor (not shown) connected to the fluid path 11 which, e.g., capacitively detects patient connection. Various aspects of function and operation of the system 10 will now be described, wherein the fluid supply device 200 and the apparatus 100 are connected to each other, including fluid connection 401, power connection 402, and control connection 403. Moreover, both the fluid supply device 200 and the apparatus 100 may be connected to mains by inlets 202 and 121, respectively. Meanwhile, the configuration of the apparatus 100, and of the system 10, allows for different stages or modes of operation of the system 10, e.g., for PD therapy. Specifically, the configuration of the apparatus 100 and of the system 10 mitigates challenges related leakage current management. In this context, the apparatus 100 will at least partly be operated as a so-called cycler.

[0116] In example, a cleaning stage may be carried out of the system. In this cleaning stage, the apparatus 100 is disconnected from the patient. This can be seen as part of a preparatory before use of the system 10 in dialysis, but the cleaning stage may as such be carried out as a final step after a previous dialysis session, so as to leave the system cleaned and disinfected. In this cleaning stage, clean water, possibly including a cleaning agent, may be used to rinse and optionally disinfect the system 10. The fluid supply device 200 may thus be configured to generate clean water instead of dialysis fluid for the cleaning stage, wherein the clean water is used to flush and replace any conductive solution from the system 10, i.e., both the fluid supply device 200 and the apparatus 100. In the cleaning stage, both the fluid supply device 200 and the apparatus 100 will subsequently perform disinfection individually, drawing power independently from mains power, i.e., from inlets 121 and 202, respectively. During disinfection, the apparatus 100 is configured to power the heater element 111 from the primary power inlet 121.

[0117] The preparatory stage may further comprise a priming step, in which dialysis fluid TF is prepared in the fluid supply device 200 and passed to the apparatus 100, to fill up the fluid parts in the apparatus 100 with dialysis fluid ready to be supplied to the patient. This priming stage may be carried out before connection (i.e., fluid connection) of the patient to the system 10, specifically the apparatus 100. In an alternative example, the priming stage is carried out after fluid connection of the patient to the system 10, and in such an example the apparatus 100 is powered at the secondary power inlet 122 from the fluid supply device 200, while the primary power inlet 121 is cut off by the relay circuit 123. Prior to connection of the patient to the apparatus 100, the relay circuit 123 is configured to disconnect the primary circuit, i.e., cut off the primary power inlet 121 from further connection in the apparatus 100. In various embodiments, this may be achieved in different ways. Different examples are listed below, of which one or more may be used.

[0118] In some embodiments, the apparatus 100 is configured to minimize the risk of the second fluid interface 132 being connected to the patient (using fluid line 11) prior to disconnection of the primary circuit 123.

[0119] In one example, an operator of the system 10 (such as the patient) may initiate dialysis operation using an initiation input on the user interface 115.

[0120] The control unit 114 may, in response to detecting the initiation input, provide control information to the relay circuit 123 to disconnect the primary circuit, using the control circuit 127. Alternatively, the control unit 114 is configured to signal the control circuit 201 of the fluid supply unit 200, using the control connection 403, in response to detecting the initiation input, to activate the power outlet 203, e.g., using the switch 204. The relay circuit 123 may thereby be configured to disconnect the primary circuit responsive to voltage being received in the secondary power inlet, as received from the power outlet 203.

[0121] In some examples, the user interface 215 is configured to output information indicative of connection or disconnection of the primary power inlet 121.

[0122] In some examples, the control unit 114 is configured to output information on the user interface 115 to hold connection of the patient to the secondary fluid interface 132 until the primary circuit is disconnected.

[0123] In some examples, the control unit 114 is configured to output information on the user interface 115 that the primary circuit is disconnected, such as a clearance to connect to the second fluid interface 132.

[0124] In some examples, the second fluid interface 132 is configured with a locking device 134, such as a mechanism, e.g., a lid, that covers or otherwise inhibits connection of the fluid line 11. The control unit 114 may be configured to control the locking device 134 to make connection to the patient possible (such as open or slide away the lid), responsive to the primary circuit being disconnected.

[0125] In some examples, the apparatus 100 comprises a holder 405, configured to secure the fluid path 11 (e.g., a tube). The holder 405 may be configured to engage and hold the fluid path 11, e.g. a connector member 404 of the fluid path, wherein said connector member 404 end is usable for connecting to the patient.

[0126] According to one example, disconnection of the fluid path 11 from the holder 405 triggers the relay circuit 123 to cut off the primary circuit, such that the primary power inlet 121 disconnected from any connection in the apparatus, specifically the power supply device 124 and the heater element 111. In the drawing, this is schematically indicated by a control line 406. It shall be noted, though, that the control line 406 may alternatively connect to the control unit 114, which triggers the relay circuit 123.

[0127] The holder 405 may comprise a sensor 407, e.g., an optical, magnetic, capacitive, RFID (Radio Frequency Identification) or other, which detects presence or absence of a cooperating member 408 arranged on the fluid line 11, such as on the connector member 404. The sensor 407 may be battery-powered or may obtain power from the control unit 114. The cooperating member 408 may be configured to specifically cooperate with the sensor 407 in the holder 405, such that presence or absence of the fluid line 11 in the holder 405 is accurately determined, and not just presence or absence of any object in the holder 405. This may be obtained by configuring the cooperating member 408 to provide a predetermined signal or response to the sensor, such as a certain pattern or signal level, or an RFID response, which is detectable in the sensor 407.

[0128] In an active dialysis stage, such as in PD therapy, typically after the preparatory stage, the system 10 is operated such that fluid is supplied from the fluid supply device 200 to the apparatus 100, which in turn is connected to the patient. At this stage, the primary circuit remains disconnected, wherein the apparatus 100 obtains low voltage power supply from the fluid supply device 200.

[0129] In one embodiment, the fluid heater 210 of the fluid supply device 200 is configured to control temperature of the fluid supplied to the apparatus 100, based on control information obtained from the apparatus 100, e.g., via the control connection 403. This is based on the notion of the heater element 111 of the apparatus being disconnected from power, upon the relay circuit cutting off the primary circuit. In this context, the temperature sensor 113 in the apparatus, still being operative due to power obtained from the fluid supply device 200 through the secondary circuit, is configured to output measurement data which is used for controlling the fluid heater 210 in the fluid supply device 200. In one example, the measurement data is processed in the control unit 114 based on a predetermined or preset target fluid temperature, wherein control signals are transmitted to the control circuit 201 to increase or decrease heat provided by the fluid heater 210.

[0130] In an alternative example, the measurement data obtained by the temperature sensor 113 is sent to the control circuit 201 of the fluid supply device 200, which controls the fluid heater 210 based on a predetermined or preset target fluid temperature.

[0131] In the context of both these alternative examples, the apparatus 100 is configured to transmit temperature control information based on sensed temperature to the fluid supply device 200 upon the heater element 111 being disconnected from power. As an additional security mechanism, the apparatus is in some examples configured to output an alert message, using the user interface 115, responsive to detecting that voltage is obtained in the secondary power inlet while the heater element is detected to receive power, which would indicate that the relay circuit 123 is malfunctioning.

[0132] Based on the foregoing, various solutions have been outlined related to the apparatus 100 and the system 10, for use in dialysis therapy, which provide a mechanism for managing leakage currents. The proposed solution makes it possible to connect two or more type BF Class II devices, such as the apparatus 100 in combination with the fluid supply device 200, that have electrical connection to the PD fluid and still pass the leakage current requirement from EN60601-1. The solution to power one or more devices from one device is also cost efficient since it requires few extra components, basically the relay circuit 123, the secondary power inlet, and optionally control software, while still enabling the apparatus 100 to operate as a cycler as a standalone machine.

[0133] 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 spirit and the scope of the appended claims.

[0134] 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.

Claims

26CLAIMS1. An apparatus (100) for use in dialysis therapy, said apparatus comprising: a fluid handling unit (110) configured to interact with fluid communicating between a first fluid interface (131) and a second fluid interface (132); power circuitry (120) connected to the fluid handling unit, said power circuitry including: a primary power inlet (121) connected via a primary circuit to the fluid handling unit; a secondary power inlet (122) connected via a secondary circuit to the fluid handling unit; and a relay circuit (123) configured to disconnect the primary circuit based on voltage being received in the secondary power inlet.

2. The apparatus of claim 1, wherein the relay circuit is configured to be normally closed, NC, to maintain galvanic connection between the primary power inlet and the fluid handling unit.

3. The apparatus of claim 1 or 2, wherein the relay circuit is configured to obtain galvanic separation of at least 5 mm between the primary power inlet and the fluid handling unit upon disconnection.

4. The apparatus of any preceding claim, wherein the fluid handling unit comprises a fluid pump unit (112), connected to obtain power either from the primary circuit or the secondary circuit, based on connection state of the relay circuit.

5. The apparatus of any preceding claim, wherein the power circuitry comprises a power supply device (124) in the primary circuit, configured to convert voltage received from the primary power inlet and to supply converted voltage to the fluid handling unit.

6. The apparatus of any preceding claim, wherein the fluid handling unit comprises a heater element (111) connected via the primary circuit, wherein the heaterelement is configured to heat fluid passed from the first fluid interface to the second fluid interface.

7. The apparatus of claim 6, wherein the fluid handling unit comprises a temperature sensor (113) configured to sense temperature of the fluid passed from the first fluid interface to the second fluid interface; wherein, upon the heater element being disconnected, the apparatus is configured to transmit temperature control information based on sensed temperature to a fluid supply device connected to the first fluid interface.

8. The apparatus of any preceding claim, wherein the first fluid interface is connectable to receive a dialysis fluid and to dispose fluid to drain, wherein the second fluid interface is connectable to a patient.

9. The apparatus of any preceding claim, wherein the primary power inlet is configured to be connected to a mains outlet.

10. The apparatus of any preceding claim, wherein the primary power inlet is configured to receive high voltage of 100-240 VAC.

11. The apparatus of any preceding claim, wherein the secondary power inlet is configured to receive low voltage of 20-30 VDC and ground connection.

12. The apparatus of any preceding claim, further comprising: a user interface (115), wherein the apparatus is configured to output information on the user interface indicative of connection or disconnection of the primary power inlet.

13. The apparatus of claim 12 and 6, wherein the apparatus is configured to output an alert message responsive to detecting that voltage is obtained in the secondary power inlet while the heater element is detected to receive power.

14. The apparatus of any preceding claim, comprising a cycler.

15. A system (10) for dialysis therapy, comprising: the apparatus (100) of any preceding claim; and a fluid supply device (200), wherein fluid supply device comprises: a power outlet (203) connectable to the secondary power inlet of the apparatus, and a fluid port (208) connectable to supply a dialysis fluid to the first fluid interface of the apparatus, wherein, upon the power outlet being connected to the secondary power inlet, the fluid handling unit is configured to be powered from the fluid supply device.

16. The system of claim 15, wherein the fluid supply device comprises a control circuit (201), configured to selectively switch supply voltage on or off to the power outlet.

17. The system of claim 15 or 16, wherein the fluid supply device comprises: a communication interface (212) connectable to receive control information from the apparatus.

18. The system of claim 17, wherein the fluid supply device comprises: a fluid heater (210), configured to control temperature of the fluid supplied to the apparatus based on control information obtained from the apparatus.

19. The system of any of claims 14-17, wherein the fluid supply device is configured to switch supply voltage on or off to the power outlet based on control information obtained from the apparatus.

20. The system of claims 19, wherein the fluid supply device is configured to switch supply voltage on to the power outlet based on the control information indicating that a patient is connected to the apparatus.

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