DIALYSIS SYSTEMS

Abstract

A dialysis system comprising a dialysis machine (100) having a main body portion, a water purification system, the water purification system being separate to the dialysis machine, and a liquid sanitizer (200). The liquid sanitizer (200) is provided within the main body portion of the dialysis machine. The liquid sanitizer (200) is fluidly connected between the dialysis machine (100) and the water purification system. The liquid sanitizer (200) has a heater (240) arranged to heat a volume of liquid, a temperature sensor arranged to sense the temperature of the volume of liquid and a liquid sanitizer controller (250). The dialysis system defines a first closed fluid circuit comprising the dialysis machine and the liquid sanitizer and a second closed fluid circuit comprising the water purification system, the dialysis machine and the liquid sanitizer. The liquid sanitizer (200) is configured to effect sanitization of the first closed fluid circuit and the second closed fluid circuit. A method of heat sanitization of a dialysis system.

Claims

1-18. (canceled)

19. A dialysis system comprising: a dialysis machine having a main body portion; a water purification system, the water purification system being separate to the dialysis machine; and a liquid sanitizer; wherein: the liquid sanitizer is provided within the main body portion of the dialysis machine; the liquid sanitizer is fluidly connected between the dialysis machine and the water purification system, the liquid sanitizer having a heater arranged to heat a volume of liquid, a temperature sensor arranged to sense the temperature of the volume of liquid and a liquid sanitizer controller, the dialysis system defining a first closed fluid circuit comprising the dialysis machine and the liquid sanitizer, wherein the first closed fluid circuit is wholly within the dialysis machine main body portion, and a second closed fluid circuit comprising the water purification system, the dialysis machine and the liquid sanitizer; and the liquid sanitizer is configured to effect sanitization of the first closed fluid circuit and the second closed fluid circuit.

20. The dialysis system of claim 19, wherein the liquid sanitizer controller is controlled by a dialysis machine controller.

21. The dialysis system of claim 20, wherein the dialysis machine is provided with a graphical user interface, wherein the graphical user interface can provide instructions to the dialysis machine controller.

22. The dialysis system of claim 19, wherein the water purification system comprises a reverse osmosis (RO) machine.

23. The dialysis system of claim 24, wherein the reverse osmosis machine has a RO machine controller.

24. The dialysis system of claim 19, wherein the liquid sanitizer controller is configured to determine a time-temperature value for the volume of liquid periodically once a threshold temperature has been exceeded and calculate a cumulative time-temperature value for the first closed fluid circuit and the second closed fluid circuit.

25. The dialysis system of claim 19, wherein the liquid sanitizer temperature sensor is an inlet water temperature sensor arranged on a tank inlet adjacent a liquid sanitizer tank.

26. The dialysis system of claim 19, wherein a liquid sanitizer outlet valve is positioned adjacent a liquid sanitizer outlet to control the flow via either the liquid sanitizer outlet or a liquid sanitizer return line.

27. The dialysis system of claim 23, wherein the RO machine controller is controlled by the dialysis machine controller.

28. A method of heat sanitization of a dialysis system, the method comprising the steps of: providing a dialysis machine having a main body portion, a water purification system, the water purification system being separate to the dialysis machine, and a liquid sanitizer, wherein the liquid sanitizer is provided within the main body portion of the dialysis machine; wherein: the liquid sanitizer being fluidly connected between the dialysis machine and the water purification system, and the liquid sanitizer having a heater arranged to heat a volume of liquid and a temperature sensor arranged to sense the temperature of the volume of liquid; heating the volume of liquid from an initial temperature to exceed a threshold temperature, maintaining the volume of water above the threshold temperature; circulating the volume of liquid through a first closed fluid circuit comprising the dialysis machine and the liquid sanitizer; and circulating the volume of liquid through a second closed fluid circuit comprising the water purification system, the dialysis machine and the liquid sanitizer to effect a sanitizing dose in the first fluid circuit and the second fluid circuit.

29. The method according to claim 28, wherein the steps of circulating the volume of liquid through the first closed fluid circuit and circulating the volume of liquid through the second closed fluid circuit are terminated in a sequential fashion.

30. The method according to claim 28, further comprising: determining a time-temperature value for the volume of liquid periodically once the threshold temperature has been exceeded and calculating a cumulative time-temperature value based upon the determined time-temperature value.

31. The method according to claim 30, wherein the cumulative time-temperature value is calculated according to $A_0=\mathrm{\Sigma 10}{e}^{\frac{T-80}{z}}\mathrm{dt}$ A.sub.0 is the A value when z is 10° C.; t is the chosen time interval, in seconds; and is the temperature in the load in ° C.

32. The method according to claim 31, where the A.sub.0 value for the first closed fluid circuit is equal to A.sub.O1 and the A.sub.0 value for the second closed fluid circuit is equal to A.sub.O2, where A.sub.O2 is greater than A.sub.O1.

33. The method according to claim 28, wherein the step of circulating the volume of liquid through a second closed fluid circuit includes using a water purification system pump.

34. The method according to claim 30, further comprising providing an output signal once the cumulative time-temperature value has reached a level indicative of a sanitizing dose in both the first fluid circuit and the second closed fluid circuit.

35. The method according to claim 30, further comprising ceasing circulation through the second closed fluid circuit once the cumulative time-temperature value equals a target cumulative time-temperature value.

36. The method according to claim 35, further comprising setting at least one of the threshold temperature, the upper temperature or the target cumulative time-temperature value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] One or more of the embodiments of the invention can now be described, by way of example only, with reference to the accompanying drawings, in which:

[0042] FIG. 1 is a schematic view of a system comprising of a reverse osmosis machine connected to a dialysis machine; and

[0043] FIG. 2 is a schematic of the system shown in FIG. 1.

DETAILED DESCRIPTION

[0044] A dialysis system liquid sanitization system 10 comprises a dialysis machine 100, a water purification system and a liquid sanitizer 200 fluidly connected there between. The water purification system is separate to the dialysis machine 100. In the specific example, the water purification system comprises a reverse osmosis (RO) machine 300.

[0045] The dialysis machine 100 has a main body 112 with a door 114 hinged to a forward-facing side of the main body 112. The door 114 has a graphical user interface. The graphical user interface is a Liquid Crystal Display (LCD) unit 116 disposed on an outward-facing door surface and a door platen disposed on an inward-facing surface. The LCD unit 116 is touch sensitive allowing user inputs to control the dialysis machine 100 and liquid sanitization system 10 as will be described in more detail below. In alternative embodiments user input can be provided using buttons, dials or other suitable pieces of apparatus.

[0046] The door 114 closes against the main body 112 to define a recess 118 there-between. A dialysis fluid mixing and pumping cartridge 130 may be housed in the recess 118 as disclosed in WO2006120415, WO2015022537, WO2018/178651, the contents of which are expressly incorporated herein by reference. The main body 112 has a platen 120 behind which is an engine portion (not shown for clarity). The platen 120 is configured to receive the dialysis fluid mixing and pumping cartridge 130 within the recess 118. The engine portion includes a pneumatic pump for providing pressure and vacuum to operate the dialysis machine 100.

[0047] The dialysis machine 100 is further provided with a dialysis machine controller 150.

[0048] The liquid sanitizer 200 is provided within the dialysis machine 100. The liquid sanitizer 200 is provided within the main body 112 of the dialysis machine 100. A dialysis machine fluid circuit 140 is fluidly connected to the liquid sanitizer 200 as will be described in more detail below.

[0049] The dialysis machine has a network of fluid pathways generally designated fluid circuit 140. In dialysis use—the dialysis treatment mode—the dialysis machine fluid circuit 140 is connectable to the dialysis fluid mixing and pumping cartridge 130, where dialysis water heated to approximately 37 degrees Celsius is drawn off. In sanitization use—liquid sanitization mode—the dialysis machine fluid circuit 140 is not connected to the dialysis fluid mixing and pumping cartridge 130, instead dialysis water heated to approximately 80 to 85 degrees Celsius is not drawn off to the dialysis fluid mixing and pumping cartridge 130 but follows the arrows on FIG. 1 along the dialysis machine fluid circuit 140.

[0050] The liquid sanitizer 200 has a number of fluid connections comprising a liquid sanitizer inlet 202, a liquid sanitizer outlet 204, a liquid sanitizer drain port 206 and a liquid sanitizer return line 222. The liquid sanitizer drain port 206 is fluidly connected to a drain 208.

[0051] The liquid sanitizer 200 has an inlet water temperature sensor 210, a liquid sanitizer tank 220, a liquid sanitizer pump 230, and a liquid sanitizer controller 250. The liquid sanitizer pump 230 may be a de-aeration pump, or another form of suitable pump. The liquid sanitizer pump 230 is disposed downstream of the liquid sanitizer tank 220 and inlet water temperature sensor 210. The liquid sanitizer tank 220 has a liquid sanitizer heater 240.

[0052] The liquid sanitizer inlet 202 is fluidly connected to the liquid sanitizer tank 220 with the inlet water temperature sensor 210 adjacent the liquid sanitizer inlet 202, upstream of the liquid sanitizer tank 220. The liquid sanitizer pump 230 is fluidly connected to the liquid sanitizer tank 220. The dialysis machine fluid circuit 140 is fluidly connected to the liquid sanitizer pump 230. The dialysis machine fluid circuit 140 is fluidly connected to the liquid sanitizer outlet 204 and separately, to the inlet water temperature sensor 210 via a liquid sanitizer return line 222. A liquid sanitizer outlet valve 205 positioned adjacent the liquid sanitizer outlet 204 controls the flow via either the liquid sanitizer outlet 204 or the liquid sanitizer return line 222.

[0053] Thus within the liquid sanitization system 10 a closed fluid circuit is provided comprising the inlet water temperature sensor 210, the liquid sanitizer tank 220, the liquid sanitizer pump 230, the dialysis machine fluid circuit 140 and the liquid sanitizer return line 222. This is the first closed fluid circuit.

[0054] The detailed structure of the liquid sanitizer 200 is shown in FIG. 2. The liquid sanitizer tank 220 contains, in use, a volume of water 224. The liquid sanitizer tank 220 has a tank inlet 226, a tank drain 228 and a tank outlet 232. The tank inlet 226 is fluidly connectable to a water source (the reverse osmosis machine). The tank drain 228 is fluidly connectable to the drain 208. The tank outlet 232 is fluidly connected to the liquid sanitizer pump 230.

[0055] The liquid sanitizer heater 240 has a heating element 248 arranged to heat the volume of water 224 contained within the liquid sanitizer tank 220, in this case by immersion in the volume of water 224. The liquid sanitizer heater 240 is electronically connected to the dialysis machine controller 150 by a heater connector 152.

[0056] Temperature sensors are arranged in the liquid sanitizer 200. An outlet temperature sensor 242 is arranged on the tank outlet 232 adjacent the liquid sanitizer tank 220. The inlet water temperature sensor 210 is arranged on the tank inlet 226 adjacent the liquid sanitizer tank 220. The temperature sensors 242, 210 are electronically connected to the dialysis machine controller 150 via sensor connectors. The connectors may be wired or wireless. The dialysis machine controller 150 may be remote to both the liquid sanitizer tank 220 and liquid sanitizer heater 240. The dialysis machine controller 150 thereby controls both the heating of the water and receives the temperature values for the sanitizing water circuit.

[0057] Referring back to FIG. 1, the reverse osmosis (RO) machine 300 has an RO pump 330, an RO filter membrane 340 and an RO controller 350.

[0058] The RO controller 350 is connected to the dialysis machine controller 150. The dialysis machine controller 150 can communicate with and control the RO controller 350.

[0059] The reverse osmosis (RO) machine 300 has a number of fluid connections comprising an RO inlet 312, an RO outlet 314, an RO return 316, an RO drain 318. The RO inlet 312 is connected to a water source 50, such as a domestic tap, via a prefiltration stage.

[0060] The RO inlet 312 is fluidly connected to the RO pump 330 with an RO non-return valve (NRV) 322 adjacent the RO inlet 312. A common fluid line 336 fluidly connects the RO inlet 312 to the RO pump 330 downstream of the RO inlet NRV 322. The RO pump 330 is fluidly connected to the RO filter membrane 340. The RO filter membrane 340 is fluidly connected to the RO outlet 314, and separately to the RO drain.

[0061] The RO return 316 is fluidly connected to the RO pump 330, with a RO return NRV 324 adjacent the RO return 316. The common fluid line 336 fluidly connects the RO return 316 to the RO pump 330 downstream of the RO return NRV 324.

[0062] The RO drain 318 is fluidly connected to the common fluid line 336, downstream of both the RO inlet NRV 322 and RO return NRV 324.

Liquid Sanitization System

[0063] The RO machine 300 is fluidly connected to a dialysis machine 100 and liquid sanitiser 200 as shown in FIG. 1. The RO outlet 314 is fluidly connected to the liquid sanitizer inlet 202. The RO return 316 is fluidly connected to the liquid sanitizer outlet 204.

[0064] The fluid connections are made by fluid lines shown schematically in FIG. 1. The fluid lines may be made of medical grade plastic or other suitable material. The fluid lines may be provided with thermally insulating covers which prevent thermal losses due to heat conduction.

[0065] Thus within the liquid sanitization system 10 a further closed circuit is provided comprising the inlet water temperature sensor 210, the liquid sanitizer tank 220, the liquid sanitizer pump 230, the dialysis machine fluid circuit 140, the RO return 316, the RO return NRV 324, the RO pump 330, the RO filter membrane 340 and the RO outlet 314. This is the second closed fluid circuit.

General Setup

[0066] Depending upon the treatment setup, the dialysis machine 100 may be setup alone, or as part of a dialysis system liquid sanitization system 10 comprising the dialysis machine 100 and the water purification system. A portable unit may be used, as described in GB2006488.7, the entire contents of each are expressly incorporated herein by reference. The water purification system is removably provided within the portable unit, whereas the dialysis machine 100 is removably provided on an upper surface of the portable unit.

Dialysis Treatment Mode

[0067] The dialysis machine 100 is used in a treatment mode to perform dialysis on a patient in a treatment session. The dialysis fluid mixing and pumping cartridge 130 is used to mix dialysis fluid constituent parts together with dialysis water from the RO machine 300, and supply the mixed dialysis fluid to a dialyser in specific quantities at specific flow rates.

[0068] The RO machine 300 in the treatment mode is operable to pump water at high pressure using the RO pump 330 (between 5 and 40 bar) across the RO filter membrane 340. This generates purified water and waste water. The purified water is pumped to the dialysis machine 100 via the RO outlet 314. The waste water is pumped to the drain 208 via the RO drain 318. The ratio of generated purified water and waste water is known as the RO recovery rate. Typically, 50% of the supplied water results in dialysis water and 50% of the supplied water results in waste water.

Liquid Sanitization Mode

[0069] In between treatment sessions, it is necessary to sanitize the fluid connections of the dialysis machine 100 and the RO machine 300. This can be done to the dialysis machine 100 individually or to the dialysis machine 100 and the RO machine 300 combined at the same time.

[0070] The user turns on liquid sanitization system 10 via the graphical user interface of the dialysis machine 100. The appropriate Liquid Sanitization Mode is selected and thus the appropriate fluid circuit is made available.

[0071] To select the first closed fluid circuit, liquid sanitizer outlet valve 205 diverts dialysis water along the liquid sanitizer return line 222. To select the second first closed fluid circuit, liquid sanitizer outlet valve 205 diverts dialysis water out of liquid sanitizer outlet 204.

[0072] The appropriate fluid circuit is primed with dialysis water from the RO machine 300, which includes filling the liquid sanitizer tank 220 of the liquid sanitizer 200.

[0073] For the first closed fluid circuit the liquid sanitizer pump 230 is activated to pump the dialysis water around the first closed fluid circuit. The dialysis water is gradually heated from a typical initial temperature of 10 degrees Celsius to a target temperature of 80 to 85 degrees Celsius as it passes through the liquid sanitizer tank 220.

[0074] For the second closed fluid circuit the liquid sanitizer pump 230 and the RO pump 330 are activated to pump the dialysis water around the second closed fluid circuit. The RO machine controller 350 is controlled by the dialysis machine controller 150 in order to activate the RO pump 330. The dialysis water is gradually heated from a typical initial temperature of 10 degrees Celsius to a target temperature of 80 to 85 degrees Celsius as it passes through the liquid sanitizer tank 220.

[0075] Thus in both cases, the dialysis machine controller 150 activates the liquid sanitizer heater 240 to heat the volume of water 224 passing through the liquid sanitizer tank 220 via the heating element 248.

[0076] When sanitizing the dialysis machine only (first closed fluid circuit), the heated water is circulated around from the liquid sanitizer tank 220, the liquid sanitizer pump 230, the dialysis machine fluid circuit 140, the liquid sanitizer return line 222 and back to the liquid sanitizer tank 220 past inlet water temperature sensor 210.

[0077] When sanitizing the dialysis machine and the reverse osmosis machine (second closed fluid circuit), the heated water is circulated around from the liquid sanitizer tank 220, the liquid sanitizer pump 230, the dialysis machine fluid circuit 140, the RO return 316, the RO return NRV 324, the RO pump 330, the RO filter membrane 340 and the RO outlet 314 and back to the liquid sanitizer tank 220 past inlet water temperature sensor 210.

[0078] Again, in both cases, the dialysis water passes the inlet water temperature sensor 210 before re-entering the liquid sanitizer tank 220 as the dialysis water circulates around either the first or second closed fluid circuit.

[0079] The temperature of the water exiting the liquid sanitizer tank 220 via tank outlet 232 is periodically sensed by outlet temperature sensor 242, and the temperature data is periodically sent to liquid sanitizer controller 250. The temperature of the water returning to the liquid sanitizer tank 220 via tank inlet 226 is periodically sensed by inlet water temperature sensor 210, and the temperature data is periodically sent to liquid sanitizer controller 250. The liquid sanitizer controller 250 therefore periodically receives sensed temperature data to provide a feedback loop to moderate the heating of the volume of water 224 to maintain the temperature of the volume of water 224 above a threshold temperature. The threshold temperature is typically between 55 degrees Celsius and 65 degrees Celsius. The liquid sanitizer controller 250 may also moderate the heating of the volume of water 224 to maintain the temperature of the volume of water 224 below an upper temperature. The upper temperature may be between 85 degrees Celsius and 99 degrees Celsius.

[0080] When the liquid sanitizer controller 250 receives data from the inlet water temperature sensor 210 that the volume of water 224 has exceeded the threshold temperature, the liquid sanitizer controller 250 periodically samples the temperature of the volume of water 224 via the inlet water temperature sensor 210, which theoretically represents the lowest possible temperature of the water on either of first and second closed fluid circuits.

[0081] The sampling is performed periodically at, for example, 1 second intervals. The sampling intervals may be varied as appropriate. Each sampled temperature represents a time-temperature value, which can be calculated by the liquid sanitizer controller 250. The liquid sanitizer controller 250 calculates a cumulative time-temperature value for the volume of water 224 by summing the sampled time-temperature values. This is compared to a target total time-temperature value indicative of a sanitizing dose for either the first and second closed fluid circuits as appropriate.

[0082] Once the calculated cumulative time-temperature value and the target cumulative time-temperature value are equal, the liquid sanitizer controller 250 sends an output signal to indicate that a sanitizing dose has been reached. The output signal is received by the liquid sanitizer heater 240 and automatically switches off the liquid sanitizer heater 240. The output signal is received by the liquid sanitizer pump 230 which is automatically switched off. In the case of the second closed fluid circuit, the output signal is also received by the RO controller 350 which relays the signal to the RO pump 330 which is automatically switched off.

[0083] In an alternate embodiment, the liquid sanitizer controller 250 may switch off the liquid sanitizer heater 240 in advance of a sanitizing dose being reached, by calculating that there is sufficient thermal energy contained within the appropriate closed fluid circuit that the water temperature will remain above the threshold temperature for long enough to ensure a sanitizing dose is reached. In that case, periodic sampling would be continued, such that the liquid sanitizer controller 250 is able to send the output signal to indicate that a sanitizing dose had indeed been reached.

[0084] The output signal is received by the graphical user interface, which displays the text “COMPLETE” in reference to the completed sanitizing dose. In alternate embodiments, the graphical user interface includes an audible alarm. The audible alarm can be configured to bleep repeatedly until the liquid sanitization system 10 is turned off.

[0085] In alternate embodiments the liquid sanitizer controller 250 calculates two cumulative time-temperature values and two target total time-temperature value indicative of a sanitizing dose. A first cumulative time-temperature value for the first closed fluid circuit and a first target time-temperature value indicative of a sanitizing dose in the first closed fluid circuit. A second cumulative time-temperature value for the second closed fluid circuit and a second target time-temperature value indicative of a sanitizing dose in the second closed fluid circuit. Having two separate cumulative time-temperature values and target time-temperature values allows for optimised control of the sanitization of the RO and dialysis machine. The sanitization can be tailored to each component using the different sanitization target times.

[0086] The heat sanitization processes may be achieved by means of the AO method which uses a knowledge of the lethality to biofilms of the particular process at different temperatures to assess the overall lethality to biofilms of the cycle and express this as the equivalent exposure time at a specified temperature.

[0087] The A value is a measure of the heat resistance of a microorganism. A is defined as the equivalent time in seconds at 80° C. to give a sanitization effect. The z value indicates the temperature sensitivity of the reaction. It is defined as the change in temperature required to change the A value by a factor of 10. When the z value is 10° C., the term A0 is used. The A0 value of moist heat sanitization process is the equivalent time in seconds at a temperature of 80° C. delivered by that process to the product with reference to microorganisms possessing a z value of 10° C.

[00002]$A_0=\mathrm{\Sigma 10}{e}^{\frac{T-80}{z}}\mathrm{dt}$ [0088] A0 is the A value when z is 10° C.; [0089] t is the chosen time interval, in seconds; [0090] and is the temperature in the load in ° C.

[0091] In calculating A0 values a temperature threshold for the integration is set at 65° C. since for temperatures below 65° C. the z and D value of thermophilic organisms may change dramatically and below 55° C. there are a number or organisms which will actively replicate. In dialysis current practice, raising the temperature to 80° C. for 30 minutes gives a benchmark value A0 equal to 1800.

[0092] The A0 value for the first fluid circuit comprising the dialysis machine is equal to A0.sub.1. The A0 value for the second fluid circuit comprising the water purification system is equal to A0.sub.2. A0.sub.2 is greater than A0.sub.1.

List of Reference Numerals

[0093] liquid sanitization system 10

[0094] water source 50

[0095] dialysis machine 100

[0096] main body 112

[0097] door 114

[0098] Liquid Crystal Display (LCD) unit 116

[0099] recess 118

[0100] platen 120

[0101] dialysis fluid mixing and pumping cartridge 130

[0102] dialysis machine fluid circuit 140

[0103] dialysis machine controller 150

[0104] heater connector 152

[0105] liquid sanitizer 200

[0106] liquid sanitizer inlet 202

[0107] liquid sanitizer outlet 204

[0108] liquid sanitizer outlet valve 205

[0109] liquid sanitizer drain port 206

[0110] drain 208

[0111] inlet water temperature sensor 210

[0112] liquid sanitizer tank 220

[0113] liquid sanitizer return line 222

[0114] volume of water 224

[0115] tank inlet 226

[0116] tank drain 228

[0117] liquid sanitizer pump 230

[0118] tank outlet 232

[0119] liquid sanitizer heater 240

[0120] outlet temperature sensor 242

[0121] heating element 248

[0122] liquid sanitizer controller 250

[0123] reverse osmosis (RO) machine 300

[0124] RO inlet 312

[0125] RO outlet 314

[0126] RO return 316

[0127] RO drain 318

[0128] RO non-return valve (NRV) 322

[0129] RO return NRV 324

[0130] RO pump 330

[0131] common fluid line 336

[0132] RO filter membrane 340

[0133] RO controller 350