Peritoneal dialysis cycler with thermal washing

Abstract

A peritoneal dialysis ("PD") system includes a dialysate pump having a reusable pump body that receives PD fluid for pumping, a dialysate in-line heater including a reusable heater body that receives PD fluid for heating, a patient line connector, a drain line connector, a first reusable PD fluid line including a first connector configured to mate with the patient line connector, a second reusable PD fluid line including a second connector configured to mate with the drain line connector, and a control unit configured to perform a thermal cleaning (e.g., thermal disinfection or thermal sterilization) sequence after a PD treatment, wherein a first connector of the first reusable PD fluid line mates with the patient line connector and a second connector of the second reusable PD fluid line mates with the drain line connector, and the dialysate pump and, if necessary, the dialysate in-line heater are activated.

Description

Technical Field

[0001] Priority Claim This application claims the priority and benefit of U.S. Provisional Patent Application No. 63 / 131,442, entitled "Peritoneal Dialysis Cycler Having Heat Cleaning," filed on December 29, 2020, the entire content of which is incorporated herein by reference and relied upon.

[0002] Background The present disclosure relates generally to medical fluid treatment, and particularly to dialysate treatment.

Background Art

[0003] For various reasons, a person's renal system may cease to function. Renal failure results in several physiological impairments. It is no longer possible to maintain the balance of water and minerals or to excrete the daily metabolic load. Toxic end products of metabolism such as urea, creatinine, and uric acid may accumulate in the patient's blood and tissues.

[0004] Reduced kidney function, particularly renal failure, is treated by dialysis. Dialysis removes excreta, toxins, and excess water from the body that a normally functioning kidney would otherwise remove. Dialysis treatment for the replacement of kidney function is important for many people because the treatment is life-saving.

[0005] One type of renal failure treatment is hemodialysis ("HD"), which generally uses diffusion to remove waste products from a patient's blood. A diffusion gradient occurs across a semipermeable dialyzer between the blood and an electrolyte solution called the dialysate or dialysis fluid, causing diffusion.

[0006] Hemofiltration ("HF") is an alternative renal replacement therapy that relies on the convective transport of toxins from a patient's blood. HF is achieved by adding a replacement fluid or substitute fluid to an extracorporeal circuit during the procedure. The replacement fluid and fluid accumulated by the patient during the procedure are ultrafiltered throughout the course of the HF procedure, providing a convective transport mechanism that is particularly beneficial for removing medium and large molecules.

[0007] Hemodiafiltration ("HDF") is a treatment method that combines convective and diffusion clearance. HDF provides diffusion clearance using dialysate flowing through a dialyzer, similar to standard hemodialysis. Furthermore, an alternative solution is supplied directly to an extracorporeal circuit to provide convective clearance.

[0008] Most HD, HF, and HDF procedures are performed in a facility. The current trend toward home hemodialysis ("HHD") exists because HHD can be performed daily and offers more therapeutic benefits than in-facility hemodialysis, which is typically performed two or three times a week. Studies have shown that more frequent procedures remove more toxins and waste products and less interdialysis overload than patients receiving less frequent but potentially longer procedures. Patients receiving more frequent procedures do not experience as much downcycling (fluid and toxin fluctuations) as in-facility patients who have accumulated two or three days' worth of toxins prior to the procedure. In certain areas, the nearest dialysis facility may be miles from the patient's home, causing door-to-door procedure time to consume a significant portion of the day. Procedures at a facility closer to the patient's home can also consume a significant portion of the patient's day. HHD can occur overnight or during the day, while the patient is relaxed, working, or otherwise productive.

[0009] Another type of renal failure treatment is peritoneal dialysis ("PD"), which involves injecting a dialysis solution, also called dialysate, into the patient's peritoneal cavity via a catheter. The dialysate is in contact with the peritoneum within the patient's peritoneal cavity. Waste, toxins, and excess water enter the dialysate from the patient's bloodstream through capillaries in the peritoneal membrane, by diffusion and osmosis, i.e., an osmotic gradient is created across the membrane. Osmotic agents in the PD dialysate provide the osmotic gradient. Used or spent dialysate is drained from the patient, removing waste products, toxins, and excess water from the patient. This cycle is repeated, for example, multiple times.

[0010] Peritoneal dialysis therapy includes various types, including continuous ambulatory peritoneal dialysis ("CAPD"), automated peritoneal dialysis ("APD"), tidal flow dialysis, and continuous flow peritoneal dialysis ("CFPD"). CAPD is a manual dialysis procedure. Here, the patient manually connects an implanted catheter to the drainage site, allowing used or spent dialysate to be drained from the peritoneal cavity. The patient then switches the fluid connection so that the patient catheter communicates with a bag of fresh dialysate, allowing fresh dialysate to be injected into the patient through the catheter. The patient then disconnects the catheter from the fresh dialysate bag, allowing the dialysate to remain in the peritoneal cavity, during which waste products, toxins, and excess water are transferred. After the retention period, the patient repeats the manual dialysis procedure, for example, four times a day. Manual peritoneal dialysis requires a considerable amount of time and effort from the patient and leaves ample room for improvement.

[0011] Automated peritoneal dialysis ("APD") is similar to CAPD in that the dialysis procedure involves draining, filling, and retention cycles. However, APD devices typically perform the cycles automatically while the patient sleeps. APD devices eliminate the need for the patient to manually perform the procedure cycles and the need to transport supplies during the day. An APD device has a fluid connection to an implanted catheter, a source or bag of fresh dialysate, and a fluid drain. The APD device pumps fresh dialysate from the dialysate source through the catheter into the patient's peritoneal cavity. The APD device also allows the dialysate to remain in the chamber, allowing for the transfer of waste, toxins, and excess water. The source may contain multiple liters of dialysate, including several solution bags.

[0012] The APD device pumps used or spent dialysis material through a catheter to drain it from the patient's peritoneal cavity. Similar to the manual process, several draining, filling, and retention cycles occur during dialysis. A "final filling" may occur at the end of an APD procedure. The final filling fluid may remain in the patient's peritoneal cavity until the start of the next procedure, or it may be manually emptied at some point during the day.

[0013] In any of the above modalities that use automated machinery, the automated machinery typically operates with disposable sets, which are discarded after a single use. Depending on the complexity of the disposable sets, the cost of using one set per day can be substantial. Additionally, daily disposable supplies require storage space, which can be a nuisance for homeowners and businesses. Furthermore, daily disposable replacements require daily setting time and effort from the patient or caregiver at home or in the clinic.

[0014] For the reasons stated above, it is desirable to provide APD machines that reduce disposable waste. [Overview of the project] [Means for solving the problem]

[0015] overview Known automated peritoneal dialysis ("PD") systems typically include a machine or cycler that receives and operates a pressurized cassette having a rigid section and a flexible section that is deformable to perform pressurization and valve operation. The rigid section is attached to a tube that extends to various bags. Disposable cassettes and associated tubes and bags can be cumbersome for patients to load at home for treatment. The total number of disposable items can also lead to multiple setup procedures that require input from the patient, potentially exposing room for error.

[0016] On the other hand, the APD system and related methodologies of this disclosure convert many of the fluid transport components of the APD system into reusable components that are heat-cleaned after treatment. Fluid lines within the machine or cycler are reused. Remaining disposable items may include patient and discharge lines, dialysate containers or bags, and optionally additional dialysate containers and tubes or lines extending from the containers to the APD cycler.

[0017] The APD system of this disclosure includes an APD cycler having a housing. At least one, and possibly three or more, reusable PD fluid lines extend from the housing. In one embodiment, if not connected to a PD fluid container or bag, the reusable PD fluid lines may be connected to a patient line cycler connector, a discharge line cycler connector, and additional cycler connectors, and used to connect a fourth dialysate container or bag to the cycler.

[0018] In another embodiment, if not connected to a PD fluid container or bag, the reusable PD fluid line is connected to a dedicated heat wash connector. In either embodiment, the reconnected PD fluid line forms a closed loop, enabling post-treatment heat wash. The remaining dialysate is used as the heat wash fluid and is intended to be heated to a disinfection temperature, for example, 70°C to 130°C, for example, 70°C for disinfection or 120°C or higher for sterilization.

[0019] Reusable PD fluid lines may be color-coded and / or keyed to match the colored or keyed connectors of the PD fluid containers or bags. The containers or bags may hold the last bags of dialysates with different dextrose or glucose levels, e.g., 1.36% glucose dialysate, 2.27% glucose dialysate, and / or different formulations of PD fluid, e.g., icodextrin.

[0020] Inside the housing, the reusable tubing in the first primary embodiment extends from each of the reusable dialysate lines through the dialysate line valves of each dialysate line to the dialysate inline heater. In embodiments, one of the valves of the APD cycler may be an electrically operated solenoid valve having a reusable valve body that closes (e.g., when power is not supplied) or opens (e.g., when power is not supplied) to allow the PD fluid to flow through the body. A bistable valve may be used as an alternative. The dialysate inline heater is also, in one embodiment, an electrically operated resistance heater having, for example, a reusable heater body that accepts the PD fluid for heating. The inline heater in embodiments can heat the PD fluid from room temperature to body temperature, e.g., 37°C, at a flow rate of at least 300 milliliters ("ml") / min. A temperature sensor is located adjacent to the heater, for example, downstream of the heater, to provide feedback for temperature control.

[0021] Reusable tubing extends from the outlet of the dialysate inline heater to a dedicated flow meter for draining used dialysate. Any tubing within the cycler housing may be metal, e.g., stainless steel, or plastic, e.g., polyetheretherketone ("PEEK"), polyvinyl chloride ("PVC"), or non-PVC materials such as polyethylene ("PE"), polyurethane ("PU"), or polycarbonate ("PC"). A reusable dialysate pump is positioned between a dedicated discharge flow meter and a dedicated filling flow meter to measure the flow of fresh dialysate to the patient. The reusable pump includes a reusable pump body that receives the PD fluid for pumping. That is, the pump does not require the PD fluid to flow through disposable items such as tubing or cassettes. The PD fluid pump may be an electric piston, membrane, gear pump, or centrifugal pump, which can be inherently volumetrically accurate, thus eliminating the need for a separate PD fluid volumetric measuring device, such as an equilibrium chamber or a device using the law of ideal gases. The inclusion of filling and discharging flow meters may reduce the accuracy of reusable PD fluid pumps, such as gear pumps, centrifugal pumps, or other types of pumps. In any case, the PD fluid pump may be controllable to pump to and from the patient below a pressure limit by controlling the level of current, voltage, or voltage pulse train supplied to the PD fluid pump. The positive pressure limit for the patient may be, for example, 1 to 5 psig. The negative pressure limit may be, for example, -1.5 psig to -3.0 psig. In one embodiment, the PD fluid pump may be bidirectional and continuous, and a single pump may be provided.

[0022] A first primary embodiment includes, in one embodiment, an air trap which may be located at different locations along the main dialysate or pumping line. In one embodiment, the air trap is located between a dedicated filling flow meter and a reusable PD fluid pump. A vent valve may be provided at the top of the air trap to discharge air for removal from the air trap. In one embodiment, one or more level sensors are located adjacent to the air trap so that a desired level or range of PD fluid level can be maintained within the air trap.

[0023] In the first primary embodiment, the pressure sensor is located between the filling flow meter and the disposable patient line, downstream of the dedicated filling flow meter. The disposable patient line connects to a patient connector provided by the cycler housing. A durable, reusable tube extends from the patient connector along the line within the housing to the dedicated filling flow meter. A pressure sensor is located along this line and may output positive and negative patient feeding pressure signals used to ensure that the patient's feeding pressure limits are not exceeded. One or more sterile filters may be placed in the disposable patient line to provide a final stage of PD fluid filtration before delivery to the patient. The PD filter may be, for example, a pass filter without a reject line. The pore size of the sterile filter may be less than a micron, for example, 0.1 or 0.2 microns.

[0024] The discharge line is also disposable in one embodiment and connects to a discharge line connector extending from the housing of the APD cycler during treatment. In addition to the valves provided on each of the dialysate line and vent valve, additional valves may be provided upstream of the inline heater, adjacent to the patient line connector, adjacent to the discharge line connector, and adjacent to an additional connector used to connect a fourth dialysate container or bag to the cycler.

[0025] After the procedure, the patient line, discharge line, and lines connected to additional connectors are removed and discarded. The PD fluid container or bag is removed from the reusable PD fluid line. The reusable PD fluid line is then reconnected to the patient line connector, discharge line connector, and additional connectors. The APD cycler and reusable PD fluid line are now fluidically closed, and a thermal cleaning fluid, such as heated fresh PD fluid, may be pumped multiple times through the closed thermal cleaning circuit in one or more directions via a pump to heat-clean (e.g., heat disinfection or heat sterilization) the internal lines, internal components (heaters, air traps, pumps, flow meters, valves, etc.), and reusable PD fluid line for the next procedure.

[0026] The APD cycler of the APD system of the present disclosure includes a control unit having one or more processors, one or more memories that receive signals or outputs from a flow meter, one or more pressure sensors, and one or more temperature sensors, and processes the signals or outputs as feedback. The control unit uses pressure feedback to control the dialysate pump and operates within a safe patient pressure limit during treatment and a safe system limit during thermal cleaning. The control unit uses temperature feedback to control the dialysate heater and heats fresh dialysate, for example, to body temperature. The control unit may also integrate the flow meter signal to determine the total amount of fresh PD fluid delivered to the patient and the total amount of used PD fluid removed from the patient. These amounts can be compared to determine the total amount of ultrafiltration ("UF") removed from the patient.

[0027] The control unit also opens and closes the dialysate valves in combination with the dialysate pump and heater to execute a priming sequence, a patient fill sequence, a patient drain sequence, and a thermal cleaning (e.g., thermal disinfection or sterilization) sequence after a PD treatment, and each of at least one reusable PD fluid line is connected to one of the line connectors as described above. The control unit described herein is provided for each of the alternative main embodiments discussed in this specification.

[0028] In a second main embodiment, the reusable PD fluid line is not plugged into the patient line and the drain line connectors, but instead is plugged into its own dedicated connectors for thermal cleaning. Instead, the patient line and the drain line connectors are provided with dedicated recirculation caps that are attached to the connectors after the procedure for thermal cleaning. The second main embodiment replaces the flow meter of the first main embodiment with a piston pump that is very substantially volumetrically accurate. The accuracy of the piston pump can be checked using a dialysate in-line heater. Here, at the start of each patient fill, the first few milliliters of fresh PD fluid are pumped through the heater without heating the fluid. A first temperature measurement value T1 is obtained. The heater is turned on, and the effect required to raise the temperature to T2, for example a fill temperature of 37°C, provides a measurement of the PD fluid flow. That is, the specific heat capacity of water is known as the temperature delta (T2 - T1) that the system control unit uses to convert the heating effect (energy / time) to flow rate (mass / time). If the difference between what the control unit calculates the fluid pump has pumped and the value determined via the heater is outside the limit, the fluid pump is recalibrated.

[0029] A third main embodiment, like the second main embodiment, provides dedicated connectors for the reusable PD fluid line, recirculation caps for the patient and drain line connectors, and a high-precision piston pump. The third main embodiment separates the internal reusable line within the cycler housing into a PD fluid line and a working fluid line, and the working fluid line is filled with a different working fluid such as reverse osmosis (“RO”) water. RO water can also be advantageously used as a flush flow for the piston pump.

[0030] The PD fluid line and the working fluid line are separated by a flexible membrane located within a pair of equilibrium chambers. The working fluid drives one side of each equilibrium chamber in a loop that includes a piston pump and an air trap to ensure there is sufficient working fluid in each stroke. In each stroke, the RO pump (i) draws RO water from one equilibrium chamber and adds an equal amount of fresh or used dialysate to that chamber on the other side of the flexible membrane, and (ii) delivers RO water to the other equilibrium chamber and removes an equal amount of fresh or used dialysate from that chamber on the other side of the flexible membrane. Thus, the equilibrium chambers provide an additional layer of precision in case the piston pump becomes inaccurate for any reason.

[0031] A third primary embodiment includes an arrangement of equilibrium chambers and a plurality of fluid valves for guiding the desired fresh or used PD fluid from a desired source to a desired destination. In one embodiment, the equilibrium chambers are alternated so that fresh or used PD fluid flows to or from the patient during the procedure, respectively. A fluid pump arranges the equilibrium chambers in RO water to move the heated PD fluid around the PD fluid thermal wash circuit. The same RO water is used over multiple procedures and may be replaced at regular service intervals.

[0032] The fourth primary embodiment is similar to the second and third primary embodiments in that it provides a dedicated connector for the reusable PD fluid line and recirculation caps for the patient and discharge line connectors. The fourth primary embodiment is also similar to the first primary embodiment in that a low-precision gear pump, centrifugal pump or other type of pump may be used, in this case two gears or other pumps. The fourth primary embodiment also provides a volumetric measuring chamber having a flexible membrane similar to the equilibrium chamber of the third primary embodiment. However, here, in contrast to the dual fluid of the third primary embodiment, fresh or used PD fluid is delivered and removed from one side of the volumetric measuring chamber membrane, while air is moved back and forth on the other side of the membrane. In one embodiment, one of the gears, centrifugal pump or other type of pump is for delivering fresh or used PD fluid to the volumetric measuring chamber (from the PD fluid container or patient, respectively), and a second gear or other pump is for removing fresh or used PD fluid from the volumetric measuring chamber (to the patient or discharge section, respectively).

[0033] In the embodiment, a fourth embodiment provides a plurality of three-way valves for controlling the flow of PD fluid. A first three-way valve is located upstream of the gear pump and is dedicated to delivering fresh or used PD fluid to the volume measurement chamber. The first three-way valve determines whether fresh or used PD fluid is delivered. A second three-way valve is located downstream of the gear pump and is dedicated to delivering fresh or used PD fluid to the volume measurement chamber. The second three-way valve determines whether the PD fluid is delivered to the first or second volume measurement chamber of the volume measurement chamber. A third three-way valve is located upstream of the gear pump and is dedicated to removing fresh or used PD fluid from the volume measurement chamber. The third three-way valve determines whether the PD fluid is removed from the first or second volume measurement chamber. A fourth three-way valve is located downstream of the gear pump and is dedicated to removing fresh or used PD fluid from the volume measurement chamber. A fourth three-way valve determines whether fresh PD fluid is delivered to the patient or used PD fluid is delivered to the discharge section. A fifth three-way valve is provided to move back and forth between the first volumetric measuring chamber and the second volumetric measuring chamber, for example during thermal cleaning.

[0034] In one embodiment, one or more pressure sensors are provided to detect the air pressure on the "dry" side of each membrane in the first and / or second volumetric measuring chamber, which reflects the PD fluid pressure on the other side of the membrane. If pressure sensors are provided in each volumetric measuring chamber, the control unit may compare readings from the two sensors, for example at the start of a procedure, to confirm that the pressure sensors are measuring the same pressure. If not, the control unit may determine that one of the pressure sensors has drifted and post a service notification on the APD cycler user interface. In one embodiment, additional pressure sensors are added along the patient line to provide feedback to ensure that the positive and negative patient pumping pressures are within safety limits.

[0035] The fifth embodiment begins with the structure of the fourth embodiment and adds a flow sensor to track the amount of fresh and used PD fluid delivered to and removed from the patient. The goal of the fourth primary embodiment is to determine the total volume of fresh and used PD fluid delivered by counting the number of strokes, relying on the accuracy of the volume measuring chamber per stroke. However, if the accuracy of the volume measuring chamber per stroke proves to be insufficiently accurate, an additional flow sensor may be used, the output of which is integrated over time to determine the overall fresh and used PD volume. In one embodiment, the flow sensor is positioned to detect the flow of both fresh and used PD fluid.

[0036] The sixth embodiment begins with the configuration of the fifth embodiment, which includes a flow sensor, again provided to track the amount of fresh and used PD fluid delivered to and taken out of the patient. The sixth embodiment adds one or more valves and fluid lines so that the PD fluid flows in the same direction through the sensor, regardless of whether the PD fluid is fresh or used. The sixth embodiment increases the number of different flow sensors that may be used, since not all flow sensors are bidirectional.

[0037] The seventh embodiment may have the same general flow path as the previous embodiments, but the membrane fluid pump and valve are driven by air. The advantage here is that the membrane fluid pump is reusable and can be calibrated with high precision during production. Also, the fluid pump chamber can be made relatively large, which should result in less frequent operation of the associated membrane valve and thus improve reliability.

[0038] In a first embodiment, which may be combined with any other embodiment or part thereof described herein, the peritoneal dialysis ("PD") system includes a housing; a dialysate pump, which includes a reusable pump body housed by the housing and receiving PD fluid for pumping; a dialysate inline heater, which includes a reusable heater body housed by the housing and receiving PD fluid for heating; a patient line connector presented by the housing; a discharge line connector presented by the housing; a first reusable PD fluid line, which includes a first connector extending from the housing and configured to mate with the patient line connector; a second reusable PD fluid line, which includes a second connector extending from the housing and configured to mate with the discharge line connector; and a control unit configured to perform a heat wash sequence after a PD procedure, wherein the first connector of the first reusable PD fluid line mates with the patient line connector, the second connector of the second reusable PD fluid line mates with the discharge line connector, and the dialysate pump and, if applicable, the dialysate inline heater are operated during the heat wash sequence.

[0039] In a second embodiment, which may be combined with any other embodiment or part thereof described herein, the PD system includes an additional connector presented by the housing and a third reusable PD fluid line including a third connector extending from the housing and configured to mate with the additional connector for thermal cleaning.

[0040] In a third embodiment, which may be combined with any other embodiment or part thereof described herein, the PD system includes a fourth fluid line, which includes a fourth connector configured to mate with an additional connector during treatment.

[0041] In a fourth embodiment, which may be combined with any other embodiment or part thereof described herein, the fourth fluid line is used to provide a place to store additional PD fluid or spillage sample for treatment.

[0042] In a fifth embodiment, which may be combined with any other embodiment or part thereof described herein, the PD system includes first and second PD fluid vessels configured to connect to first and second connectors, respectively.

[0043] In a sixth embodiment, which may be combined with any other embodiment or part thereof described herein, the first and second connectors are different from each other.

[0044] In a seventh embodiment, which may be combined with any other embodiment or part thereof described herein, the PD includes a disposable patient line configured to connect to a patient line connector and a disposable discharge line configured to connect to a discharge line connector.

[0045] In an eighth embodiment, which may be combined with any other embodiment or part thereof described herein, at least one of the first or second reusable PD fluid lines is provided with one or more covers, one or more of which are opened and closed to disconnect and connect the first connector to and from the patient line connector, or the second connector to and from the discharge line connector, respectively.

[0046] In a ninth embodiment, which may be combined with any other embodiment or part thereof described herein, the control unit is configured to (i) cause a dialysate inline heater to heat the PD fluid to at least 70°C or at least 120°C for the sterilization level of the heat wash, and (ii) cause a dialysate pump to recirculate the heated PD fluid during the heat wash sequence.

[0047] In a tenth embodiment, which may be combined with any other embodiment or part thereof described herein, the dialysate pump is a piston, gear, or membrane pump, and the reusable pump body of the piston, gear, or membrane pump receives the PD fluid for pumping.

[0048] In an eleventh embodiment, which may be combined with any other embodiment or part thereof described herein, the peritoneal dialysis ("PD") system includes a housing; a dialysate pump, which is housed by the housing and includes a reusable pump body for receiving PD fluid for pumping; a dialysate inline heater, which is housed by the housing and includes a reusable heater body for receiving PD fluid for heating; a patient line connector presented by the housing, which includes a patient line recirculation cap that, when sealed by a patient line recirculation cap, allows the PD fluid to be recirculated through the patient line connector; and a discharge line connector presented by the housing, which, when sealed by a discharge line recirculation cap, allows the PD fluid to be recirculated through the discharge line connector. The device includes a discharge line connector, which includes a discharge line recirculation cap that allows the fluid to be recirculated; at least one reusable PD fluid line; at least one heat wash connector, which is supported by a housing and configured to accept one of the at least one reusable PD fluid lines; and a control unit configured to perform a heat wash sequence after a PD procedure, wherein the patient line connector is capped by a patient line recirculation cap, the discharge line connector is capped by a discharge line recirculation cap, each of the at least one reusable PD fluid line is connected to one of the at least one heat wash connector, and at least one of a dialysate pump or a dialysate inline heater is operated during the heat wash sequence.

[0049] In a twelfth embodiment, which may be combined with any other embodiment or part thereof described herein, the control unit is configured to perform a first PD fluid flow rate determination using first and second dialysate temperature measurements of the PD fluid heated by a heater under the control of the control unit, and to compare the first PD fluid flow rate determination with a second PD fluid flow rate determination based on the corresponding operation of a dialysate pump.

[0050] In a thirteenth embodiment, which may be combined with any other embodiment or part thereof described herein, the PD system includes at least one cover positioned and arranged to releasably and securely cap at least one heat cleaning connector during a heat cleaning sequence.

[0051] In a 14th embodiment, which may be combined with any other embodiment or part thereof described herein, at least one of the patient line recirculation cap or the discharge line recirculation cap includes an internal passage for recirculation.

[0052] In a 15th embodiment, which may be combined with any other embodiment or part thereof described herein, the PD system includes at least one PD fluid vessel configured to receive one of at least one reusable PD fluid lines.

[0053] In a 16th embodiment, which may be combined with any other embodiment or part thereof described herein, the PD system includes a disposable patient line configured to connect to a patient line connector and a disposable discharge line configured to connect to a discharge line connector.

[0054] In a 17th embodiment, which may be combined with any other embodiment or part thereof described herein, the control unit is configured to (i) cause a dialysate inline heater to heat the PD fluid to at least 70°C or at least 120°C for the sterilization level of the heat wash, and (ii) cause a dialysate pump to recirculate the heated PD fluid during the heat wash sequence.

[0055] In an 18th embodiment, which may be combined with any other embodiment or part thereof described herein, the dialysate pump is a piston, gear, or membrane pump, and the reusable pump body of the piston, gear, or membrane pump receives the PD fluid for pumping.

[0056] In a 19th embodiment, which may be combined with any other embodiment or part thereof described herein, the peritoneal dialysis ("PD") system includes a housing; a patient line connector presented by the housing, comprising a patient line recirculation cap that enables recirculation of PD fluid through the patient line connector when sealed by a patient line recirculation cap; a discharge line connector presented by the housing, comprising a discharge line recirculation cap that enables recirculation of PD fluid through the discharge line connector when sealed by a discharge line recirculation cap; at least one reusable PD fluid line; at least one heat cleaning connector supported by the housing and configured to accept at least one reusable PD fluid line; and at least one fixed housing comprising a flexible membrane that separates the process fluid side of the chamber from the PD fluid side of the chamber. The device comprises a stacking chamber, a process fluid pump configured to pump process fluid to and from the process fluid side of at least one fixed volume chamber, to discharge PD fluid from the PD fluid side of at least one fixed volume chamber, and to draw PD fluid into the PD fluid side, respectively, a dialysate inline heater housed in a housing and in fluid communication with the PD fluid side of at least one fixed volume chamber, and a control unit configured to perform a heat wash sequence after a PD treatment, wherein the patient line connector is capped by a patient line recirculation cap, the discharge line connector is capped by a discharge line recirculation cap, each of at least one reusable PD fluid lines is connected to one of at least one heat wash connectors, and the process fluid pump and optionally the dialysate inline heater are operated during the heat wash sequence.

[0057] In a 20th embodiment, which may be combined with any other embodiment or part thereof described herein, the dialysate inline heater selectively communicates with the PD fluid side of at least one fixed-volume chamber via at least one valve.

[0058] In a 21st embodiment, which may be combined with any other embodiment or part thereof described herein, at least one fixed-volume chamber comprises first and second fixed-volume chambers, each chamber comprising a flexible membrane separating the process fluid side of the first or second chamber from the PD fluid side of the first or second chamber, and a process fluid pump is positioned and arranged to pump process fluid from the other of the first or second chamber while pumping process fluid to the process fluid side of one of the first or second chambers.

[0059] In a 22nd embodiment, which may be combined with any other embodiment or part thereof described herein, the process fluid is water or air.

[0060] In a 23rd embodiment, which may be combined with any other embodiment or part thereof described herein, the process fluid pump is a piston pump, and the process fluid is further used as a flush fluid for the piston pump.

[0061] In a 24th embodiment, which may be combined with any other embodiment or part thereof described herein, the process fluid pump is in fluid communication with the process fluid side of at least one fixed-volume chamber via a process fluid circuit, the process fluid circuit includes a storage chamber for storing an additional amount of process fluid.

[0062] In a 25th embodiment, which may be combined with any other embodiment or part thereof described herein, the dialysate inline heater is positioned between at least one reusable PD fluid line and the PD fluid side of at least one fixed-volume chamber.

[0063] In a 26th embodiment, which may be combined with any other embodiment or part thereof described herein, the PD system includes a first valve between each of at least one reusable PD fluid lines and a dialysate inline heater, and at least one second valve between the dialysate inline heater and each of the PD fluid sides of at least one fixed volume chamber.

[0064] In a 27th embodiment, which may be combined with any other embodiment or part thereof described herein, when sealed by a patient line recirculation cap, the patient line connector is in fluid communication with (i) fresh or used PD fluid lines extending from each PD fluid side of at least one fixed volume chamber, and (ii) a heat cleaning line extending to each of at least one heat cleaning connector.

[0065] In a 28th embodiment, which may be combined with any other embodiment or part thereof described herein, when not capped by a patient line recirculation cap, the patient line connector is in fluid communication with (i) fresh or used PD fluid lines extending from each PD fluid side of at least one fixed volume chamber, and (ii) disposable patient lines.

[0066] In a 29th embodiment, which may be combined with any other embodiment or part thereof described herein, when sealed by a discharge line recirculation cap, the discharge line connector is in fluid communication with (i) spent PD fluid lines extending from each PD fluid side of at least one fixed volume chamber, and (ii) thermal cleaning lines extending to each of at least one thermal cleaning connectors.

[0067] In a 30th embodiment, which may be combined with any other embodiment or part thereof described herein, when not capped by a patient line recirculation cap, the discharge line connector (i) is in fluid communication with used PD fluid lines extending from the respective PD fluid sides of at least one fixed volume chamber and a disposable discharge line.

[0068] In a 31st embodiment, which may be combined with any other embodiment or part thereof described herein, the peritoneal dialysis ("PD") system includes a housing; a patient line connector presented by the housing, comprising a patient line recirculation cap that enables recirculation of PD fluid through the patient line connector when sealed by a patient line recirculation cap; a discharge line connector presented by the housing, comprising a discharge line recirculation cap that enables recirculation of PD fluid through the discharge line connector when sealed by a discharge line recirculation cap; at least one reusable PD fluid line; at least one heat cleaning connector supported by the housing and configured to accept at least one reusable PD fluid line; and a few flexible membranes separating the compressible fluid side of the chamber from the PD fluid side of the chamber. The device comprises at least one fixed-volume chamber, at least one PD fluid pump configured to pump PD fluid to and from the PD fluid side of at least one fixed-volume chamber to pressurize and depressurize a compressible fluid, respectively, at least one PD fluid pump, at least one PD fluid pump, at least one PD fluid pump configured to pressurize and depressurize a compressible fluid by pumping PD fluid to and from the PD fluid side of at least one fixed-volume chamber, a dialysate inline heater housed in a housing and in fluid communication with the PD fluid side of at least one fixed-volume chamber, and a control unit configured to perform a heat wash sequence after a PD treatment, wherein the patient line connector is capped by a patient line recirculation cap, the discharge line connector is capped by a discharge line recirculation cap, each of at least one reusable PD fluid lines is connected to one of at least one heat wash connectors, and the PD fluid pump and optionally the dialysate inline heater are operated during the heat wash sequence.

[0069] In a 32nd embodiment, which may be combined with any other embodiment or part thereof described herein, the dialysate inline heater selectively communicates with the PD fluid side of at least one fixed-volume chamber via at least one valve.

[0070] In a 33rd embodiment, which may be combined with any other embodiment or part thereof described herein, at least one fixed-volume chamber comprises first and second fixed-volume chambers, each chamber comprising a flexible membrane separating the compressible fluid side of the first or second chamber from the PD fluid side of the first or second chamber, and at least one PD fluid pump is positioned and arranged to pump PD fluid from the other of the first or second chamber while pumping PD fluid to the PD fluid side of one of the first or second chambers.

[0071] In a 34th embodiment, which may be combined with any other embodiment or part thereof described herein, the PD system includes a compressible fluid circuit extending between the compressible fluid sides of first and second fixed-volume chambers, the compressible fluid circuit enabling (i) compressible fluid pushed from one compressible fluid side into the other compressible fluid side, or (ii) compressible fluid to be discharged into the atmosphere.

[0072] In a 35th embodiment, which may be combined with any other embodiment or part thereof described herein, the compressible fluid is air.

[0073] In a 36th embodiment, which may be combined with any other embodiment or part thereof described herein, at least one PD fluid pump includes first and second PD fluid pumps, each positioned and arranged to pump fresh and used PD fluid into and from at least one fixed-volume chamber.

[0074] In a 37th embodiment, which may be combined with any other embodiment or part thereof described herein, the PD system includes at least one three-way valve selected from: (i) a first three-way valve positioned and arranged to guide fresh or used PD fluid into a first or second fixed-volume chamber; (ii) a second three-way valve positioned and arranged to guide fresh or used PD fluid into a first or second fixed-volume chamber; (iii) a third three-way valve positioned and arranged to guide fresh PD fluid from the first or second fixed-volume chamber and used PD fluid into the first or second fixed-volume chamber; (iv) a fourth three-way valve positioned and arranged to guide fresh PD fluid to a patient line connector or from there used PD fluid and used PD fluid, or air, or fresh PD fluid to a discharge line connector; or (v) a fifth three-way valve positioned and arranged to move back and forth between the first or second fixed-volume chambers during a heat wash sequence.

[0075] In a 38th embodiment, which may be combined with any other embodiment or part thereof described herein, the dialysate inline heater is positioned between at least one reusable PD fluid line and the PD fluid side of at least one fixed-volume chamber.

[0076] In a 39th embodiment, which may be combined with any other embodiment or part thereof described herein, when sealed by a patient line recirculation cap, the patient line connector is in fluid communication with (i) a fresh or used PD fluid line and (ii) a heat cleaning line extending to each of at least one heat cleaning connector.

[0077] In a 40th embodiment, which may be combined with any other embodiment or part thereof described herein, when not capped by a patient line recirculation cap, the patient line connector is in fluid communication with (i) a fresh or used PD fluid line and (ii) a disposable patient line.

[0078] In a 41st embodiment, which may be combined with any other embodiment or part thereof described herein, when sealed by a discharge line recirculation cap, the discharge line connector is in fluid communication with (i) a spent PD fluid line and (ii) a heat cleaning line extending to each of at least one heat cleaning connector.

[0079] In a 42nd embodiment, which may be combined with any other embodiment or part thereof described herein, when not capped by a patient line recirculation cap, the discharge line connector is in fluid communication with (i) a used PF fluid line and (ii) a disposable discharge line.

[0080] In a 43rd embodiment, which may be combined with any other embodiment or part thereof described herein, the PD system includes a flow meter that outputs to a control unit, the flow meter being positioned and arranged to measure the flow rates of fresh and used PD fluid.

[0081] In a 40th embodiment, which may be combined with any other embodiment or part thereof described herein, the PD system is configured such that fresh and used PD fluids move in the same direction through a flow meter.

[0082] In the 45th aspect, any feature, function, and alternative example described in relation to one or more of Figures 1 to 6 may be combined with any feature, function, and alternative example described in relation to any other of Figures 1 to 6.

[0083] Therefore, the advantage of this disclosure is to provide an automated peritoneal dialysis ("APD") cycler that reuses many components that would otherwise be disposable.

[0084] Another advantage of this disclosure is to provide an APD cycler having a fluid handling component that directly receives peritoneal dialysis fluid without the need to handle disposable items such as tubes or flexible sheets.

[0085] A further advantage of this disclosure is to provide an APD cycler that can utilize any remaining unused PD fluid during thermal cleaning.

[0086] Another advantage of this disclosure is the provision of a volumetrically accurate automated peritoneal dialysis (APD) cycler.

[0087] Another advantage of this disclosure is to provide an APD cycler having hydraulic pressure control for the fluid being pumped between the patient and the patient.

[0088] Another advantage of this disclosure is that it provides a relatively quiet APD cycler.

[0089] A further advantage of this disclosure is that it provides a relatively simple disposable set.

[0090] Another advantage of the present disclosure is to provide a reusable fluid circuit having a small total volume such that the PD fluid remaining in the PD fluid container at the end of the procedure is sufficient to fill the entire volume of the reusable fluid circuit and perform thermal cleaning.

[0091] Another advantage of this disclosure is to provide an APD system in which the patient line from a first APD procedure is used as the discharge line in a second APD procedure.

[0092] Additional features and advantages will be described in the following detailed description and drawings and will be apparent therefrom. The features and advantages described herein are not exhaustive, and many additional features and advantages will be apparent to those skilled in the art in consideration of the drawings and description. Furthermore, no particular embodiment is required to possess all of the advantages enumerated herein, and it is clearly intended that individual advantageous embodiments be claimed separately. In addition, it should be noted that the language used herein has been chosen primarily for readability and explanatory purposes and does not limit the scope of the subject matter of the invention. The present invention provides, for example, the following: (Item 1) A peritoneal dialysis ("PD") system, Housing and A dialysate pump, including a reusable pump body housed in the above housing and receiving PD fluid for pressurization, A dialysate inline heater, which includes a reusable heater body housed in the above housing and receiving PD fluid for heating, The patient line connector presented by the above housing, The discharge line connector provided by the above housing, A first reusable PD fluid line including a first connector extending from the housing and configured to mate with the patient line connector, A second reusable PD fluid line, including a second connector extending from the housing and configured to mate with the discharge line connector, A control unit configured to perform a heat wash sequence after PD treatment, wherein the first connector of the first reusable PD fluid line is mated with the patient line connector, the second connector of the second reusable PD fluid line is mated with the discharge line connector, and the dialysate pump and, if necessary, the dialysate inline heater are operated during the heat wash sequence, and the control unit and A PD system equipped with this feature. (Item 2) The PD system according to item 1, comprising an additional connector presented by the housing and a third reusable PD fluid line including a third connector extending from the housing and configured to mate with the additional connector for thermal cleaning. (Item 3) The PD system according to item 2, including a fourth fluid line including a fourth connector configured to mate with the additional connector mentioned above during treatment. (Item 4) The fourth fluid line described above is used to provide a place to store additional PD fluid or spilled samples for treatment, as described in item 3 of the PD system. (Item 5) The PD system according to item 1, comprising first and second PD fluid vessels configured to be connected to the first and second connectors described above, respectively. (Item 6) The first and second connectors described above are different from each other, as per item 1 of the PD system. (Item 7) The PD system according to item 1, comprising a disposable patient line configured to connect to the above-mentioned patient line connector, and a disposable discharge line configured to connect to the above-mentioned discharge line connector. (Item 8) The PD system according to item 1, wherein at least one of the first or second reusable PD fluid lines is provided with one or more lids, and the one or more lids are opened and closed to disconnect and connect the first connector to and from the patient line connector, or the second connector to and from the discharge line connector, respectively. (Item 9) The PD system according to item 1, wherein the control unit is configured to (i) cause the dialysate inline heater to heat the PD fluid to at least 70°C or at least 120°C for a sterilization level of thermal washing, and (ii) cause the dialysate pump to recirculate the heated PD fluid during the thermal washing sequence. (Item 10) The above-mentioned dialysate pump is a piston, gear, or membrane pump, and the above-mentioned reusable pump body of the piston, gear, or membrane pump receives the PD fluid for pressurization in the PD system as described in item 1. (Item 11) A peritoneal dialysis ("PD") system, Housing and A dialysate pump, including a reusable pump body housed in the above housing and receiving PD fluid for pressurization, A dialysate inline heater, which includes a reusable heater body housed in the above housing and receiving PD fluid for heating, A patient line connector presented by the housing, wherein the patient line connector includes a patient line recirculation cap that allows PD fluid to be recirculated through the patient line connector when it is sealed by the patient line recirculation cap, A discharge line connector presented by the above housing, wherein the discharge line connector includes a discharge line recirculation cap that allows PD fluid to be recirculated through the discharge line connector when it is sealed by the discharge line recirculation cap, At least one reusable PD fluid line, Supported by the above housing, at least one heat cleaning connector configured to accept one of the at least one reusable PD fluid lines, A control unit configured to perform a heat wash sequence after PD treatment, wherein the patient line connector is capped by the patient line recirculation cap, the discharge line connector is capped by the discharge line recirculation cap, each of the at least one reusable PD fluid lines is connected to one of the at least one heat wash connectors, and at least one of the dialysate pump or the dialysate inline heater is operated during the heat wash sequence, and A PD system equipped with this feature. (Item 12) The PD system according to item 11, wherein the control unit is configured to perform a first PD fluid flow rate determination using first and second dialysate temperature measurements of the PD fluid heated by a heater under the control of the control unit, and to compare the first PD fluid flow rate determination with a second PD fluid flow rate determination based on the corresponding operation of the dialysate pump. (Item 13) The PD system according to item 11, comprising at least one cover positioned and arranged to releasably and securely cap the at least one heat cleaning connector during the heat cleaning sequence described above. (Item 14) The PD system according to item 11, wherein at least one of the above-mentioned patient line recirculation cap or the above-mentioned discharge line recirculation cap includes an internal passage for recirculation. (Item 15) The PD system according to item 11, comprising at least one PD fluid container configured to receive one of the above-mentioned reusable PD fluid lines. (Item 16) The PD system according to item 11, comprising a disposable patient line configured to connect to the above-mentioned patient line connector, and a disposable discharge line configured to connect to the above-mentioned discharge line connector. (Item 17) The PD system according to item 11, wherein the control unit is configured to (i) cause the dialysate inline heater to heat the PD fluid to at least 70°C or at least 120°C for a sterilization level of thermal washing, and (ii) cause the dialysate pump to recirculate the heated PD fluid during the thermal washing sequence. (Item 18) The above-mentioned dialysate pump is a piston, gear, or membrane pump, and the above-mentioned reusable pump body of the piston, gear, or membrane pump receives the PD fluid for pressurization in the PD system as described in item 11. (Item 19) A peritoneal dialysis ("PD") system, Housing and A patient line connector presented by the housing, wherein the patient line connector includes a patient line recirculation cap that allows PD fluid to be recirculated through the patient line connector when it is sealed by the patient line recirculation cap, A discharge line connector presented by the above housing, wherein the discharge line connector includes a discharge line recirculation cap that allows PD fluid to be recirculated through the discharge line connector when it is sealed by the discharge line recirculation cap, At least one reusable PD fluid line, Supported by the housing described above, at least one heat cleaning connector configured to accept at least one reusable PD fluid line, A fixed-volume chamber comprising a flexible membrane that separates the process fluid side of the chamber from the PD fluid side of the chamber, A process fluid pump, wherein the process fluid pump is configured to pump process fluid to and from the process fluid side of the at least one fixed volume chamber, to discharge PD fluid from the PD fluid side of the at least one fixed volume chamber, and to draw PD fluid into the PD fluid side, respectively. A dialysate inline heater housed in the above housing and in fluid communication with the PD fluid side of the at least one fixed volume chamber, A control unit configured to perform a heat wash sequence after PD treatment, wherein the patient line connector is capped by the patient line recirculation cap, the discharge line connector is capped by the discharge line recirculation cap, each of the at least one reusable PD fluid lines is connected to one of the at least one heat wash connectors, and the process fluid pump and optionally the dialysate inline heater are operated during the heat wash sequence, and A PD system equipped with this feature. (Item 20) The PD system according to item 19, wherein the dialysate inline heater selectively communicates with the PD fluid side of the at least one fixed volume chamber via at least one valve. (Item 21) The PD system according to item 19, wherein the at least one fixed volume chamber comprises first and second fixed volume chambers, each chamber comprising a flexible membrane separating the process fluid side of the first or second chamber from the PD fluid side of the first or second chamber, and the process fluid pump is positioned and arranged to pump the process fluid from the other of the first or second chamber while pumping the process fluid to the process fluid side of one of the first or second chambers. (Item 22) The above process fluid is water or air, as described in item 19 of the PD system. (Item 23) The above process fluid pump is a piston pump, and the above process fluid is further used as a flush fluid for the above piston pump, as described in item 19 of the PD system. (Item 24) The PD system according to item 19, wherein the process fluid pump is in fluid communication with the process fluid side of the at least one fixed volume chamber via a process fluid circuit, and the process fluid circuit includes a storage chamber for storing an additional amount of process fluid. (Item 25) The dialysis fluid inline heater is positioned between the at least one reusable PD fluid line and the PD fluid side of the at least one fixed volume chamber, as described in item 19 of the PD system. (Item 26) The PD system according to item 25, comprising a first valve between each of the at least one reusable PD fluid lines and the dialysate inline heater, and at least one second valve between the dialysate inline heater and the PD fluid side of each of the at least one fixed volume chambers. (Item 27) The PD system according to item 19, wherein when sealed by the patient line recirculation cap, the patient line connector is in fluid communication with (i) fresh or used PD fluid lines extending from the PD fluid side of each of the at least one fixed volume chambers, and (ii) a heat cleaning line extending to each of the at least one heat cleaning connector. (Item 28) When not capped by the patient line recirculation cap, the patient line connector is in fluid communication with (i) the fresh or used PD fluid lines extending from each of the PD fluid sides of the at least one fixed volume chamber, and (ii) the disposable patient line, as described in item 27 of the PD system. (Item 29) The PD system according to item 27, wherein the discharge line connector is in fluid communication with (i) a used PD fluid line extending from the PD fluid side of each of the at least one fixed volume chambers, and (ii) a heat cleaning line extending to each of the at least one heat cleaning connector. (Item 30) The PD system according to item 29, wherein the discharge line connector, when not capped by the patient line recirculation cap, (i) is in fluid communication with the used PD fluid line extending from the PD fluid side of each of the at least one fixed volume chamber and disposable discharge line. (Item 31) A peritoneal dialysis ("PD") system, Housing and A patient line connector presented by the housing, wherein the patient line connector includes a patient line recirculation cap that allows PD fluid to be recirculated through the patient line connector when it is sealed by the patient line recirculation cap, A discharge line connector presented by the above housing, wherein the discharge line connector includes a discharge line recirculation cap that allows PD fluid to be recirculated through the discharge line connector when it is sealed by the discharge line recirculation cap, At least one reusable PD fluid line, Supported by the housing described above, at least one heat cleaning connector configured to accept at least one reusable PD fluid line, A fixed-volume chamber comprising a flexible membrane that separates the compressible fluid side of the chamber from the PD fluid side of the chamber, At least one PD fluid pump, the at least one PD fluid pump is configured to pressurize the compressible fluid and depressurize the compressible fluid by pumping PD fluid to and from the PD fluid side of the at least one fixed volume chamber, respectively. A dialysate inline heater housed in the above housing and in fluid communication with the PD fluid side of the at least one fixed volume chamber, A control unit configured to perform a heat wash sequence after PD treatment, wherein the patient line connector is capped by the patient line recirculation cap, the discharge line connector is capped by the discharge line recirculation cap, each of the at least one reusable PD fluid lines is connected to one of the at least one heat wash connectors, and the PD fluid pump and optionally the dialysate inline heater are operated during the heat wash sequence, and the control unit and A PD system equipped with this feature. (Item 32) The PD system according to item 31, wherein the dialysate inline heater selectively communicates with the PD fluid side of the at least one fixed volume chamber via at least one valve. (Item 33) The PD system according to item 31, wherein the at least one fixed volume chamber comprises first and second fixed volume chambers, each chamber comprising a flexible membrane separating the compressible fluid side of the first or second chamber from the PD fluid side of the first or second chamber, and the at least one PD fluid pump is positioned and arranged to pump PD fluid from the other of the first or second chamber while pumping PD fluid to the PD fluid side of one of the first or second chambers. (Item 34) The PD system according to item 33, comprising a compressible fluid circuit extending between the compressible fluid sides of the first and second fixed-volume chambers, wherein the compressible fluid circuit allows (i) a compressible fluid pushed from one of the compressible fluid sides to enter the other of the compressible fluid sides, or (ii) a compressible fluid to be discharged into the atmosphere. (Item 35) The compressible fluid is air, as described in item 31 of the PD system. (Item 36) The PD system according to item 31, wherein the at least one PD fluid pump includes first and second PD fluid pumps positioned and arranged to pump fresh and used PD fluid into and from the at least one fixed-volume chamber. (Item 37) A PD system according to item 31, comprising at least one three-way valve selected from (i) a first three-way valve positioned and arranged to guide fresh or used PD fluid into a first or second fixed-volume chamber, (ii) a second three-way valve positioned and arranged to guide fresh or used PD fluid into the first or second fixed-volume chamber, (iii) a third three-way valve positioned and arranged to guide fresh PD fluid from the first or second fixed-volume chamber and used PD fluid into the first or second fixed-volume chamber, (iv) a fourth three-way valve positioned and arranged to guide fresh PD fluid to the patient line connector or from there used PD fluid and used PD fluid, or air, or fresh PD fluid to the discharge line connector, or (v) a fifth three-way valve positioned and arranged to move back and forth between the first or second fixed-volume chamber during the heat wash sequence. (Item 38) The PD system according to item 31, wherein the dialysate inline heater is positioned between the at least one reusable PD fluid line and the PD fluid side of the at least one fixed volume chamber. (Item 39) The PD system according to item 31, wherein the patient line connector is in fluid communication with (i) a fresh or used PD fluid line and (ii) a heat cleaning line extending to each of the at least one heat cleaning connector, when sealed by the patient line recirculation cap described above. (Item 40) When not capped by the patient line recirculation cap, the patient line connector is in fluid communication with (i) the fresh or used PD fluid line and (ii) the disposable patient line, as described in item 39 of the PD system. (Item 41) The PD system according to item 39, wherein the discharge line connector is in fluid communication with (i) a used PD fluid line and (ii) a heat cleaning line extending to each of the at least one heat cleaning connector, when sealed by the discharge line recirculation cap. (Item 42) When not capped by the patient line recirculation cap, the discharge line connector is in fluid communication with (i) the used PF fluid line and (ii) the disposable discharge line, as described in item 41 of the PD system. (Item 43) The PD system according to item 31, comprising a flow meter that outputs to the control unit, wherein at least one flow meter is positioned and arranged to measure the flow rates of fresh and used PD fluids. (Item 44) The PD system described in item 43, wherein fresh and used PD fluids are configured to move in the same direction through the flow meter described above. [Brief explanation of the drawing]

[0093] [Figure 1] Figure 1 is a schematic diagram of one embodiment of an associated system using the automated peritoneal dialysis ("APD") cycler and thermal washing described herein.

[0094] [Figure 2] Figure 2 is a schematic diagram of a second embodiment of an APD cycler and associated system using the thermal cleaning of the present disclosure.

[0095] [Figure 3] Figure 3 is a schematic diagram of a third embodiment of an APD cycler and associated system using the thermal cleaning of the present disclosure.

[0096] [Figure 4] Figure 4 is a schematic diagram of a fourth embodiment of an APD cycler and associated system using the thermal cleaning of the present disclosure.

[0097] [Figure 5] Figure 5 is a schematic diagram of a fifth embodiment of an APD cycler and associated system using the thermal cleaning of the present disclosure.

[0098] [Figure 6] Figure 6 is a schematic diagram of a sixth embodiment of an APD cycler and associated system using the thermal cleaning of the present disclosure. [Modes for carrying out the invention]

[0099] Detailed explanation Referring here to the drawings, particularly Figure 1, the automated peritoneal dialysis ("APD") system 10a and associated methodologies of this disclosure include an APD machine or cycler 20a. The system 10a and cycler 20a (as with other systems and cyclers described herein) seek to eliminate disposable items as much as possible and instead provide most of its fluid transport portion as reusable components, which are disinfected or sterilized along with the flow paths of the cycler 20a between procedures. The fluid lines within the machine or cycler are reused. In particular, Figure 1 shows that the cycler 20a includes a housing 22 from which reusable PD fluid lines 24a to 24c extend. The reusable PD fluid lines 24a to 24c extend to reusable line connectors 26a to 26c, respectively. In the illustrated embodiment, the reusable PD fluid lines 24a to 24c and line connectors 26a to 26c are provided on lids 28a to 28c and may be attached to the housing 22, for example, via hinges. The lids 28a to 28c open on a hinge, allowing the line connectors 26a to 26c to connect to the disposable PD fluid containers 102a to 102c. The lids 28a to 28c close on a hinge, allowing the line connectors 26a to 26c to connect to reusable cycler connectors 30a to 30c, respectively.

[0100] As used herein, “heat washing” may mean “heating over time to at least a sufficient disinfection level, and possibly to a sterilization level.” The practical difference between disinfection and sterilization levels is that if the cycler channels and components are sterilized or washed to a sterilization level, no further filtration is required. If the cycler channels and components are disinfected or washed to a disinfection level, some kind of filtration is provided, e.g., one or more sterilized, sterile-grade filters (not shown, which may be sterilized themselves) in the patient line 104. The goal of each of the systems 10a to 10f described herein is to heat wash the cycler channels and components to a sterilization level so that no additional filtration is required. However, if it is found that a sterilization level cannot be consistently met, additional filtration, e.g., sterile-grade filters in the patient line 104 (not shown), must be provided. Thus, as used herein, “heat washing” may mean at least disinfected and sterilized, if possible.

[0101] PD fluid containers 102a to 102c may be provided as part of the disposable set 100, for example, sterilized, together with a disposable patient line 104, a disposable discharge line 106, and an optional additional disposable supply line 108. In an alternative embodiment, for example, the sterilized disposable set 100 includes a disposable patient line 104, a disposable discharge line 106, and optionally an additional disposable supply line 108, but the PD fluid containers 102a to 102c are provided separately to connect to reusable PD fluid lines 24a to 24c at the start of the procedure. The disposable patient line 104 may extend to the patient for the procedure, and the disposable discharge line 106 may extend to a disposable discharge container or a house discharge section. The disposable set 100 may further include an optional fourth PD fluid container 102d that connects to a reusable cycler connector 30c via a disposable supply line 108 during the procedure. Any of the reusable PD fluid lines 24a to 24c, any of the reusable tubes located within the cycler 20a, any part of the housing 22, and any part of the disposable set 100 may be made from metal, such as stainless steel, steel, or plastic, such as polyetheretherketone ("PEEK"), polyvinyl chloride ("PVC"), or non-PVC material such as polyethylene ("PE"), polyurethane ("PU"), or polycarbonate ("PC").

[0102] In one embodiment, the disposable patient line 104 in the first procedure is used as the disposable discharge line 106 in the second procedure. Reusing the disposable patient line 104 as a future discharge line further reduces disposable waste and is intended for each of the systems 10a to 10f described herein.

[0103] Multiple embodiments are contemplated to prevent a used patient line from being reused as a new patient line. One method for this is mechanical. For example, if the patient cycler connector 30a is different from the discharge cycler connector 30b, the disposable patient line 104 is configured such that, after treatment, the end previously connected to the patient cycler connector 30a is instead connected to the other end of the disposable patient line 104 that was connected to the patient transport set, forming a loop for storage between treatments, and the connection forming the loop is permanent, so that the end previously connected to the patient cycler connector 30a cannot be reconnected to the patient cycler connector. A connector for connecting to the discharge cycler connector 30b is provided elsewhere in the loop, covered by a fragile cover that is removed for a second treatment to expose the disposable discharge connector, for example, by loosening a screw from the mating connector to make the loop excessive.

[0104] In another mechanical example, where again the patient cycler connector 30a is different from the discharge cycler connector 30b, the disposable patient line 104 is configured such that the disposable patient connector previously connected to the patient cycler connector 30a is connected at the other end to a disposable discharge connector or a short line leading to a disposable discharge connector. Here, the disposable discharge connector must be exposed first before use.

[0105] Another or additional method to help prevent the reuse of disposable patient line 104 as a patient line in a second procedure is to chemically modify the patient line. In one example, a reusable patient cycler connector 30a and a reusable discharge cycler connector 30b have the same configuration so that the discharge cycler connector 30b accepts the same end of a disposable patient line 104 that has been previously used as a patient line. For example, it is intended that the end of the patient line 104 has a patient / discharge line connector with an indicator that changes color when in contact with PD fluid, so that a patient or caregiver installing patient line 104 and discharge line 106 for a new procedure can easily identify which line to install into the discharge cycler connector 30b.

[0106] PD fluid containers 102a to 102d may hold dialyzes with different dextrose or glucose levels, such as 1.36% glucose dialyze, 2.27% glucose dialyze, and / or final bags of different formulations of PD fluid, such as icodextrin. In the illustrated embodiment, PD fluid containers 102b to 102d hold one or more filled volumes of 1.36% glucose or 2.27% glucose dialyze, for example, PD fluid, while PD fluid container 102a holds a single final filled volume of icodextrin formulated to remain in the patient for an extended period.

[0107] In the illustrated embodiment, all components located within the cycler 20a are reusable, reducing the amount of disposable materials to those listed above for the disposable set 100. PD fluid valves 32a to 32e allow selected PD fluid to flow along the reusable inlet line 34a to the reusable heater 36. In the embodiment, each of the valves in the APD cycler 20a, including the PD fluid valves 32a to 32e, is an electrically operated valve having a reusable valve body that closes (e.g., when power is supplied) or opens (e.g., when power is not supplied for fail-safe operation) to allow PD fluid to flow through the body. Bistable valves may be used alternatively, perhaps only in non-critical safety positions. The dialysate inline heater 36 is also, in one embodiment, a resistance heater having a reusable heater body that is electrically operated and accepts PD fluid for treatment and thermal cleaning (e.g., thermal disinfection or thermal sterilization).

[0108] In this embodiment, the inline heater 36 can heat the PD fluid from room temperature or lower (e.g., if the PD fluid is stored in a low-temperature environment) to body temperature, for example, 37°C, at a flow rate of at least 300 milliliters ("ml") / min. Lower flow rates may also be achieved, for example, for children or infants. The temperature sensor 38 is located adjacent to the heater 36, for example, downstream of the heater, and provides feedback for temperature control. A second temperature sensor (not shown) may be provided upstream of the heater 36 to allow the heating algorithm to take into account the inflow temperature of the fresh PD fluid, if necessary. The heater 36 and temperature sensor 38 can function as flow meters, e.g., control or protective / safety flow meters, as described in more detail herein.

[0109] A reusable pumping line 34b extends downstream from the inline heater 36. Several fluid components, including a first flow meter 40a, a second flow meter 40b, and a PD fluid pump 42 positioned between the first and second flow meters 40a and 40b, are arranged along the reusable pumping line 34b. The flow meters 40a and 40b in this embodiment are electromagnetic or Coriolis flow meters. The flow meters 40a and 40b are reusable and can be used not only to regulate the flow rate but also to consolidate the volumes of fresh and used PD fluid over the course of the procedure, so that at the end of the procedure, it is known how much fresh PD fluid has been delivered to the patient and how much used PD fluid has been removed from the patient. The difference between the two is equal to the total amount of fluid removed from the patient over the course of the procedure, at least a portion of which may be removed by ultrafiltration ("UF"), which is an important parameter to achieve and monitor.

[0110] In one embodiment of patient filling (fresh PD fluid flowing from right to left) shown in Figure 1, flowmeter 40b is used as a primary control flowmeter because it is more accurate due to the removal of air bubbles in the air trap 44 upstream of flowmeter 40b (flowmeter 40a is used as a protective or safety flowmeter). During patient discharge (used PD fluid flowing from left to right), where the flow direction reverses, flowmeter 40a is used as a primary control flowmeter because it is more accurate due to the removal of air bubbles in the air trap 44 upstream of flowmeter 40a (flowmeter 40b is used as a protective or safety flowmeter).

[0111] The provision of flow meters 40a and 40b allows the use of less precise PD fluid pumps 42, such as gear pumps, centrifugal pumps, or other types of pumps. The PD fluid pump 42 includes a reusable pump body that receives the PD fluid for pumping. That is, the PD pump 42 does not require the PD fluid to flow through disposable items such as tubes or cassettes. The reusable pump body of the pump 42 itself receives the PD fluid. The dialysate pump 42 can be controlled to pump to and from the patient below a pressure limit by controlling the level of current, voltage, or voltage pulse train to the PD fluid pump. The positive pressure limit for the patient may be, for example, 1 to 5 psig (e.g., 2 psig (14 kPa)). The negative pressure limit for the patient may be, for example, -1.0 psig to -3.0 psig (e.g., -1.3 psig (-9 kPa)). The pump 42 can also supply lower pressures as needed, for example, for infants or young children. In one embodiment, the dialysate pump 42 is bidirectional and continuous, so that a single pump may be provided.

[0112] Two-way flowmeters 40a and 40b may be provided so that their outputs can be compared to ensure accuracy. Alternatively, a particular flowmeter may be unidirectional, with one of the flowmeters 40b used for patient filling and the other for patient discharge. Also, if a particular flowmeter functions better under positive or negative pressure, flowmeters 40a and 40b may be positioned accordingly on the appropriate side of the PD fluid pump 42. If two unidirectional flowmeters 40a and 40b are provided, two additional unidirectional flowmeters, or possibly a single bidirectional flowmeter, may be provided, with the unidirectional flowmeters 40a and 40b used for control and one or more other flowmeters used for redundancy / protection in case of hazardous situations due to malfunction of the components.

[0113] In the illustrated embodiment, the air trap 44 is located between the PD fluid pump 42 and the flow meters 40a and 40b, but the air trap 44 may be located in an alternative location along the reusable pumping line 34b. In one preferred embodiment, the air trap 44 is located somewhere between the flow meters 40a and 40b. The air trap 44 removes air from the fresh PD fluid before it reaches the patient. Additional volume may be useful, for example, during thermal cleaning (e.g., thermal disinfection or thermal sterilization). The air trap 44 may also be provided with any of the cyclers 20a to 20f of each system described herein, even if not illustrated.

[0114] The pressure sensor 46 is positioned along the reusable patient line 34c between the flow meter 40b and the patient. The pressure sensor 46 records the pressure of the fresh PD fluid delivered to the patient and the used PD fluid withdrawn from the patient. The pressure readings are used to control the PD fluid pump 42, thereby ensuring that the pressures of the fresh and used PD fluid flows remain within the patient pressure limits listed above.

[0115] The reusable patient line 34c extends from the flow meter 40b to the reusable patient cycler connector 30a. The reusable discharge line 34d extends from the patient line 34b to the reusable discharge cycler connector 30b. The reusable vent line 34e extends from the top of the air trap 44 to the discharge line 34d, allowing air to be directed to the discharge section. The patient valve 32f is located along the reusable patient line 34c. The discharge valve 32g is located along the reusable discharge line 34d. The vent valve 32h is located along the reusable vent line 34e. Valves 32f through 32h may also be electrically actuated valves having reusable valve bodies that close (e.g., if power is supplied) or open (e.g., if power is not supplied for fail-safe operation) to allow fresh or used PD fluid or air to flow through the body (e.g., if power is supplied).

[0116] Figure 1 shows that the APD cycler 20a of the system 10a of the present disclosure includes a control unit 50 having one or more processors 52 and one or more memories 54 that receive, store, and process signals or outputs from flow meters 40a, 40b, pressure sensor 46, temperature sensor 38, optional conductivity sensor (shown below), and lid position sensor for detecting whether connectors 26a to 26c of lids 28a to 28c are installed, respectively (to enable the start of a procedure or an alarm, respectively). The control unit 50 uses pressure feedback to control the dialysate pump 42 to pump fresh and used PD fluid at safe patient and system pressure limits. The control unit 50 uses temperature feedback to control the inline dialysate heater 36 to heat fresh dialysate to, for example, body temperature, and at the end of a procedure to heat the wash fluid to wash (disinfect or sterilize) the reusable fluid pathways of the cycler 20a. The control unit 50 analyzes fresh and / or used dialysate using temperature-compensated conductivity readings for the reasons discussed herein.

[0117] The control unit 50 also includes a video controller 56 that interfaces with a user interface 58, which may include a display screen operated by one or more electromechanical buttons such as a touchscreen and / or membrane switches. The user interface 58 may also include one or more speakers for outputting alarms, warnings, and / or voice induction commands. The user interface 58 may also include a cycler 20a as shown in Figure 1 and / or a remote user interface operated by the control unit 50. The control unit 50 may also include transceivers (not shown) and wired or wireless connections to a network, such as the Internet, for transmitting treatment data to a physician's or clinician's server that interfaces with the physician's or clinician's computer and receiving prescription orders from the physician's or clinician's server.

[0118] The control unit 50 also opens and closes the dialysate valves 32a to 32h in different combinations of operation with the dialysate pump 42 and heater 36 to perform a priming sequence, a multi-patient filling sequence, a multi-patient draining sequence, and a heat washing (e.g., heat disinfection or heat sterilization) sequence at the end of the PD procedure.

[0119] The cycler 20a shown in Figure 1 is configured with lids 28a to 28c open to allow (i) a reusable PD fluid line 24a to be connected to a disposable PD fluid container 102a, (ii) a reusable PD fluid line 24b to be connected to a disposable PD fluid container 102b, (iii) a reusable PD fluid line 24c to be connected to a disposable PD fluid container 102c, (iv) a reusable patient cycler connector 30a to be connected to a disposable patient line 104, and (v) a reusable discharge cycler connector 30b to be connected to a disposable discharge line 106. The containers 102a to 102c may be disposable and may include ports or small disposable lines for connecting to the reusable lines 24a to 24c, respectively. In the illustrated embodiment, any disposable PD fluid container 102d is connected to the reusable supply connector 30c via a disposable supply line 108. If no disposable PD fluid container 102d and disposable supply line 108 are provided, the reusable supply connector 30c may be configured to close itself in a spring mechanism or to close via a separate (potentially connected) cap.

[0120] At the end of the procedure, after each of the PD fluid containers 102a to 102d has been emptied, the disposable items are removed as follows: (i) disposable PD fluid container 102a is removed from the reusable line connector 26a; (ii) disposable PD fluid container 102b is removed from the reusable line connector 26b; (iii) disposable PD fluid container 102c is removed from the reusable line connector 26c; (iv) patient line 104 is removed from the reusable patient cycler connector 30a; (v) disposable discharge line 106 is removed from the reusable discharge cycler connector 30b; and (v) disposable supply line 108, if provided, is removed from the reusable cycler connector 30c. For thermal cleaning (e.g., thermal disinfection or thermal sterilization), the user closes the lid 28a so that (i) the reusable line connector 26a is connected to the reusable patient cycler connector 30a, (ii) the lid 28b is connected to the reusable discharge cycler connector 30b, and (iii) the lid 28c is connected to the reusable line connector 26c is connected to the reusable cycler connector 30c.

[0121] Providing covers 28a to 28c makes improper connection of reusable line connectors 26a to 26c to reusable cycler connectors 30a to 30c less likely; nevertheless, in all other systems and cycler embodiments described herein, the line connectors 26a to 26c and cycler connectors 30a to 30c are intended to be color-coded and / or keyed to match the pairs of connectors.

[0122] With the covers 28a to 28c closed and the connectors 26a / 30a, 26b / 30b, and 26c / 30c connected, the fluid circuit of the cycler 20a is also closed for thermal cleaning (e.g., thermal disinfection or thermal sterilization). In the embodiment, the control unit 50 opens all valves 32a to 32h, activates the PD fluid pump 42, and energizes the heater to circulate the heated cleaning fluid, for example multiple times, through a closed cleaning loop including reusable PD fluid lines 24a to 24c, a reusable inlet line 34a, a reusable pressure line 34b, a reusable patient line 34c, a reusable discharge line 34d, and a reusable ventilation line 34e. In one embodiment, the cleaning fluid is PD fluid, for example, fresh PD fluid, which is heated to a disinfection or sterilization temperature, for example, 70°C to 130°C, for example, 70°C for disinfection and 120°C or higher for sterilization. Various valves 32a to 32h may be opened and closed as needed, and the PD fluid pump 42 may reverse direction one or more times. The thermal cleaning (e.g., thermal disinfection or thermal sterilization) sequence for system 10a continues until a sufficient thermal cleaning dose (e.g., dose A0) is provided to adequately clean (disinfect or sterilize) each and all components of the lines and all components that come into contact with the reusable fluid pathways listed above and discussed herein.

[0123] In an alternative embodiment, the reusable cycler connectors 30a to 30c become line connectors and are moved to the ends of the patient line 104, the discharge line 106, and the supply line 108, respectively. If any supply container 102d is not used, the reusable line connector may again be configured to close itself with a spring, or it may be capped via a separate, for example, connected cap. At the end of the procedure, all disposable PD fluid containers 102a to 102d are removed, and the line connectors 30a to 30c are connected to the reusable PD fluid lines 24a to 24c to close the heat wash loop. The control unit 50 performs the heat wash (e.g., thermal disinfection or thermal sterilization) sequence as described above. In this alternative embodiment, the lids 28a to 28c may or may not be provided.

[0124] Referring here to Figure 2, the alternative APD system 10b and related methodologies of this disclosure include an APD machine or cycler 20b. System 10b includes many of the same components as system 10a, which are numbered the same and may or may not be described in relation to system 10b, but in any case include all the structures, functions and alternative forms described in relation to system 10a. In particular, the cycler 20b includes a housing 22 that holds PD fluid valves 32a to 32c and discharge valve 32g, a reusable inlet line 34a, an inline heater 36, at least one temperature sensor 38, an air trap 44, a reusable pressurized line 34b, at least one pressure sensor 46, a reusable patient line 34c, a reusable discharge line 34d, a reusable vent line 34e, a discharge valve 32g, a control unit 50, and a user interface 58. The cycler 20b also includes reusable PD fluid lines 24a to 24c extending to reusable line connectors 26a to 26c, respectively. A reusable patient cycler connector 30a and a reusable discharge cycler connector 30b are also provided.

[0125] The differences from the alternative APD system 10b include the removal of flow meters 40a and 40b and the replacement of pump 42, e.g., a less accurate gear or other pump, with an essentially more accurate piston or membrane pump 142 under the control of the control unit 50, which accurately pumps all fresh PD fluid being delivered and all used PD fluid being removed, thereby enabling the control unit 50 to accurately calculate the patient fluid (e.g., UF) removed during the course of treatment. The piston pump 142 may require a flush flow of fluid, such as reverse osmosis ("RO") water, during treatment for lubrication, which is supplied, for example, from an RO water source via a water pump (not shown) under the control of the control unit 50. Like all pumps herein, the piston pump 142 includes a body that accepts fresh or used dialysate and does not operate with disposable components.

[0126] To verify the inherent accuracy of the piston pump 142, the control unit 50 may, at the start of each patient filling, pump a few milliliters of fresh PD fluid through the heater 36 without heating the fluid. The initial temperature measurement T1 is obtained at the temperature sensor 38. The heater 36 is then energized, and the effect required to raise the temperature to T2, for example, a filling temperature of 37°C, as measured at the temperature sensor 38, provides a measurement of the PD fluid flow. The accuracy of the piston pump 142 can be checked using the dialysate inline heater 36. Here, at the start of each patient filling, the control unit 50 pumps a few milliliters of fresh PD fluid through the heater 36 without heating the fluid. The control unit 50 obtains the initial temperature measurement T1. The control unit 50 then energizes the heater 36 and measures the effect required to raise the temperature to T2, for example, a filling temperature of 37°C, providing a measurement of the PD fluid flow. The control unit 50 knows the specific heat capacity and temperature delta (T2-T1) of water, and uses this to convert the heating effect (energy / time) into flow rate (mass / time). If the difference between the value calculated by the control unit 50 for the fluid pump 142 and the value determined via the heater 36 is outside the limit, the control unit 50 has the user interface 58 notify the user that the pump 142 needs to be recalibrated and / or sends a communication via the network to the service portal indicating this. Redundant volume calculations and related checks using the heater 36 may be performed in any of the systems 10a to 10f described herein.

[0127] Another difference from system 10b is the inclusion of one or more level sensors 48 (which may be included in system 10a) equipped with an air trap 44, which output to the control unit 50. The one or more level sensors 48 allow for the maintenance of a specific level or range of fresh PD fluid within the air trap 44. The one or more level sensors 48 may be equipped with any of the air traps described herein. System 10b includes a conductivity sensor 60 positioned along the reusable discharge line 34d, which outputs to the control unit 50 and may be temperature compensated. The conductivity sensor 60 may be used, for example during priming, to detect the conductivity of fresh PD fluid to ensure that it is of a predetermined type, for example, a predetermined glucose or dextrose concentration. A conductivity sensor 74 may be used alternatively or additionally, for example during priming, to detect the conductivity of fresh PD fluid to ensure that it is properly mixed, for example, when an online PD fluid source is instead connected to one of the reusable PD fluid lines 24a to 24c. Alternatively or additionally, a conductivity sensor 74 may be used to detect the conductivity of the PD fluid being used to assess the effectiveness of the procedure and / or to look for patient diseases such as peritonitis. A temperature sensor 58b is placed near the conductivity sensor 74 so that the conductivity readings from the sensor can be temperature compensated.

[0128] A further difference from system 10b is the provision of three-way valves 132a and 132b, each under the control of control unit 50. The three-way valves 132a and 132b are switched back and forth between allowing fresh or used PD fluid to flow in one direction or a second direction. The three-way valve 132a is switched between (i) allowing fresh or used dialysate to flow between the piston pump 142 and the patient cycler connector 30a (connected to the disposable patient line 104), or (ii) allowing PD fluid for priming or heat washing, such as heated fresh PD fluid, to flow from valve 132a through the reusable priming / heat washing line 34f, the discharge valve 32g, the conductivity sensor 60, and the reusable discharge line 34d (connected to the disposable discharge line 106 for priming) to flow to the house or container discharge section for priming, or in the same and / or other directions. The three-way valve 132b switches between (i) allowing fresh or used dialysate to flow between the reusable pressurized line 34b and the patient cycler connector 30a (connected to the disposable patient line 104), and (ii) allowing air, PD fluid, or mixtures thereof for priming, treatment, or heat washing to be discharged from the air trap 44 through the reusable vent line 34e, a portion of the pressurized line 34b, and the three-way valve 132b as described above, through the reusable discharge line 34d and the cycler connector 30b (connected to the disposable discharge line 106).

[0129] Another difference from system 10b is that after the PD fluid containers 102a to 102c are disconnected following the treatment for thermal cleaning, line connectors 26a to 26c are instead plugged into the thermal cleaning connector or ports 62a to 62c to form a closed thermal cleaning loop. In the illustrated embodiment, ports 62a to 62c are each protected by, for example, a cover 64 hinged to the cycler 20b, which is moved out of the way so that line connectors 26a to 26c can be connected to or plugged into the thermal cleaning connector or ports 62a to 62c. The thermal cleaning connector or ports 62a to 62c may be either self-closing, e.g., spring-loaded, or properly sealed via the cover 64. The thermal cleaning connector or ports 62a to 62c as shown are fluid-connected to a second thermal cleaning line 34g.

[0130] To perform thermal cleaning and form a closed thermal cleaning loop, the patient cycler connector 30a and the discharge cycler connector 30b are each provided with recirculation caps 66, which seal tightly to the connectors 30a and 30b during thermal cleaning, returning the thermal cleaning fluid flowing through the reusable lines 34c and 34d back to the second thermal cleaning line 34g (or returning the thermal cleaning fluid flowing through the second thermal cleaning line 34g back to the reusable lines 34c and 34d). When closed to the connectors 30a and 30b, the recirculation caps 66 include or define an internal fluid lumen or pathway 68 that fluidizes both the second thermal cleaning line 34g and either the reusable line 34c or the reusable line 34d. The flow during disinfection / sterilization of system 10b has many alternatives as all lines are disinfected / sterilized. One of the main heat cleaning pathways starts from pump 42, flows through reusable priming / heat cleaning line 34f and reusable discharge line 34d, is discharged to discharge connector 30b, then passes through reusable line 34g to patient connector 30a, flows through heat cleaning connector or port 62a to 62c, and returns to pump 42 through heater 36 and air trap 44.

[0131] With the heat cleaning loop closed in this manner, the control unit 50 executes the heat cleaning (e.g., thermal disinfection or thermal sterilization) sequence as described above, for example, by using heated fresh PD fluid, pumping it in multiple directions, and switching valves as needed. The three-way valves 132a and 132b in the embodiment are switched back and forth to allow the heat cleaning fluid to flow through each alternative path. The heat cleaning sequence of system 10b continues until a sufficient heat cleaning dose (e.g., dose A0) is provided to properly sterilize each of the lines forming the closed heat cleaning loop provided in cycler 10b.

[0132] Referring here to Figure 3, another alternative APD system 10c and related methodology of this disclosure includes an APD machine or cycler 20c. System 10c includes many of the same components as systems 10a and 10b, which are numbered and may or may not be described in relation to system 10c, but in either case, it includes all the structures, functions, and alternative forms described in relation to systems 10a and 10b. In particular, the cycler 20c includes a housing 22 that holds PD fluid valves 32a to 32c, a reusable inlet line 34a, an inline heater 36, at least one temperature sensor 38, an air trap 44, a reusable pressure feed line 34b, pressure sensors 46a and 46b, a reusable patient line 34c, a reusable discharge line 34d, a reusable vent line 34e, a reusable heat wash line 34g, a discharge valve 32g, a vent valve 32h, a control unit 50, a conductivity sensor 60 along the reusable discharge line 34d, and a user interface 58.

[0133] The cycler 20c also includes reusable PD fluid lines 24a to 24c extending to reusable line connectors 26a to 26c, respectively. A reusable patient cycler connector 30a and a reusable discharge cycler connector 30b are also provided. The cycler 20c of system 10c forms a closed thermal cleaning loop in the same manner as the cycler 10b of system 10b, using thermal cleaning connectors or ports 62a to 62c and a movable cover 64 for connecting the reusable PD fluid lines 24a to 24c via the reusable line connectors 26a to 26c, as described above for system 10b. The cycler 20c also provides a recirculation cap 66 having an internal fluid lumen or path for connecting to and closing the reusable patient cycler connector 30a and the reusable discharge cycler connector 30b for thermal cleaning, as described for system 10b.

[0134] The cycler 20c of system 10c also includes a highly precise piston or membrane pump 142 under the control of the control unit 50, as described above for the cycler 10b of system 10b. A piston pump 142, like all pumps herein, includes a body that accepts fresh or used dialysate and does not operate on disposable components. The piston pump 142 may require a flush flow of fluid, such as reverse osmosis ("RO") water, during lubrication procedures (although a flush flow may not be necessary as the piston pump 142 pumps RO water, etc.). The cycler 20c, as described, provides a source of such RO water. In particular, the cycler 20c separates the internal reusable line or tube PD fluid line from the working fluid line, and the working fluid line is filled with a different working fluid, such as reverse osmosis ("RO") water. Although not shown, in one embodiment, the working fluid loop 70 (described later), including the piston pump 142, is arranged so that the fluid enters the inlet of the piston pump 142 from the outlet flash flow port through the flash flow port of the piston pump 142. Such an arrangement is likely to reduce the amount of tubing required for the flash flow and provide a speed that exceeds a sufficient velocity for the flash flow.

[0135] The PD fluid line and the working fluid line are separated by a flexible membrane provided within a pair of equilibrium chambers 72a and 72b. The working fluid (e.g., RO water) drives one side of each of the equilibrium chambers 72a and 72b within a working fluid loop 70, which includes a piston pump 142 and a storage chamber 144 for holding the working fluid (e.g., RO water), thereby ensuring that there is sufficient working fluid in each stroke of the equilibrium chambers 72a and 72b. The working fluid loop 70 also includes working fluid valves 32i and 32j under the control of a control unit 50, which are arranged in the stroke equilibrium chambers 72a and 72b. The control unit 50 closes the valves 32i and 32j during treatment to lock the working fluid in place and make the working side fluidly rigid. The valves 32i and 32j may be opened during the thermal cleaning phase for circulation if it is desirable to allow some heat to reach the working side. Valves 32i and 32j may also be opened to allow fresh working fluid into the piston pump 142 in order to compensate for the inherent leakage flow between the piston and the cylinder of the piston pump 142.

[0136] In each stroke of the equilibrium chambers 72a and 72b, the RO pump 142 (i) draws RO water from one equilibrium chamber 72a or 72b and delivers a similar volume of fresh or used dialysate to that equilibrium chamber on the other side of the flexible membrane, and (ii) delivers the RO water to the other equilibrium chamber 72a or 72b and delivers a similar volume of fresh or used dialysate from that equilibrium chamber on the other side of the flexible membrane. The equilibrium chambers 72a and 72b provide an additional layer of accuracy in case the piston pump 142 becomes inaccurate for any reason. That is, since the volumes of the equilibrium chambers 72a or 72b are known, the control unit can assume that each time they are stroked, either a chamber volume of fresh dialysate is delivered to the equilibrium chamber or used dialysate is removed from the patient. Thus, counting the strokes of the equilibrium chambers 72a or 72b allows the control unit 50 to accumulate the total amount of fresh and used PD fluid delivered. The amount can be compared to the sum of fresh and used PD fluid calculated by the control unit 50, which counts the known volumetric pumping strokes of the RO piston pump 142.

[0137] In the illustrated embodiment, during treatment, the control unit 50 closes the working fluid valves 32i and 32j, causing the piston pump 142 to pump RO water in either opposite directions: (i) drawing RO water from the equilibrium chamber 72a and pushing it into the equilibrium chamber 72b, or (ii) drawing RO water from the equilibrium chamber 72b and pushing it into the equilibrium chamber 72a. When not in treatment, the control unit 50 may open one or both of the working fluid valves 32i and 32j (or switch between opening and closing the valves) for the various reasons described above, and for a fresh flush flow of RO in the piston pump 142.

[0138] On the treatment fluid side, the cycler 20c includes a pair of patient valves 32f1 and 32f2, each under the control of the control unit 50. Patient valve 32f1 allows fresh PD fluid to flow from the output stroke of the equilibrium chamber 72a to the patient via the reusable patient line 34c, or used PD fluid to flow from the patient to the equilibrium chamber 72a via the reusable patient line 34c during the inspiratory stroke. Similarly, patient valve 32f2 allows fresh PD fluid to flow from the output stroke of the equilibrium chamber 72b to the patient via the reusable patient line 34c, or used PD fluid to flow from the patient to the equilibrium chamber 72b via the reusable patient line 34c during the inspiratory stroke.

[0139] On the treatment fluid side, the cycler 20c also includes a plurality of supply and / or discharge valves 32k to 32n, each under the control of the control unit 50. The supply and discharge valves 32k allow fresh PD fluid to flow into the equilibrium chamber 72a via the reusable pressurized line 34b during the intake stroke, or used PD fluid to be discharged from the equilibrium chamber 72a via the discharge line 34d during the output stroke. The supply valve 32l is used to allow fresh PD fluid to flow into either the equilibrium chamber 72a or the equilibrium chamber 72b via the reusable pressurized line 34b during the intake stroke. The supply valve 32m allows fresh PD fluid to flow into the equilibrium chamber 72b via the reusable pressurized line 34b during the fresh PD fluid intake stroke, and allows used PD fluid to be discharged from the equilibrium chamber 72a via the reusable discharge cycler connector 30b during the used PD fluid discharge stroke. The supply and discharge valves 32n allow fresh PD fluid to flow into the equilibrium chamber 72b via the reusable pressure line 34b during the intake stroke, or used PD fluid to flow from the equilibrium chamber 72b to the discharge section via the discharge line 34d during the output stroke. The control unit 50 also sequences the supply and / or discharge valves 32k to 32n during thermal cleaning to guide fresh heated PD fluid in the desired manner during the sequence.

[0140] The cycler 20c offers several advantages, including the ability to position pressure sensors 46a and 46b along the working fluid loop 70, which means that if a fluid leak occurs involving the pressure sensors, the leak will contain RO water rather than dialysate. Nevertheless, pressure sensors 46a and 46b provide accurate positive and negative PD fluid pressure readings, and the PD fluid pressure is accurately transmitted across the flexible membranes of the equilibrium chambers 72a and 72b. Also, the piston pump 142 pumps RO water instead of fresh or used PD fluid, which at least partially reduces wear and extends the lifespan of components (e.g., pressure sensors 46a and 46b) because the piston pump 142 does not need to be exposed to heated or chemical heat cleaning fluids. Placing the components within the working fluid loop 70 makes the cycler 20c well suited to the higher temperatures and cleaning times associated with sterilization versus heat cleaning as described above. Furthermore, as described above, the working fluid loop 70 and storage chamber 144 provide a ready supply of flash flow fluid for the piston pump 142.

[0141] After the procedure, with the heat cleaning loop closed as described in relation to the cycler 20b (with the PD fluid lines 24a to 24c connected to the cycler and recirculation cap 66 closed), the control unit 50 performs a heat cleaning (e.g., thermal disinfection or thermal sterilization) sequence of the cycler 20c using, for example, heated fresh PD fluid, pumping in multiple directions and switching valves as needed. The cycler 20c may, under the control of the control unit 50, provide additional heat cleaning pumps 242, such as low-precision gear pumps, centrifugal pumps or other types of pumps, along, for example, the reusable heat cleaning line 34g as needed. The heat cleaning (e.g., cleaning activity) sequence of the system 10c continues until a sufficient heat cleaning dose is provided and each treatment fluid line forming the closed heat cleaning loop supplied to the cycler 10c is properly sterilized. Again, the working fluid loop 70 does not need to be disinfected.

[0142] Referring here to Figure 4, another alternative APD system 10d and related methodology of this disclosure includes an APD machine or cycler 20d. System 10d includes many of the same components as systems 10a to 10c, which are numbered the same and include all the structures, functions, and alternative forms described in relation to systems 10a to 10c, whether or not they are described in relation to system 10d. In particular, cycler 20d includes a housing 22 that holds PD fluid valves 32a to 32c, a reusable inlet line 34a, an inline heater 36, at least one temperature sensor 38, a reusable pressurized line 34b, a pressure sensor 46, a reusable patient line 34c, a reusable used PD fluid line 34d, a reusable thermal cleaning line 34g, a recirculation valve 32g, a conductivity sensor 60 positioned along the reusable used PD fluid line 34d, a control unit 50, and a user interface 58.

[0143] The cycler 20d also includes reusable PD fluid lines 24a to 24c extending to reusable line connectors 26a to 26c, respectively. A reusable patient cycler connector 30a and a reusable discharge cycler connector 30b are also provided. The cycler 20d of system 10d forms a closed thermal cleaning loop in the same manner as the cyclers 20b and 20c of systems 10b and 10c, using thermal cleaning connectors or ports 62a to 62c and a movable, for example, hinged cover 64 for connecting the reusable PD fluid lines 24a to 24c via the reusable line connectors 26a to 26c, as described above for systems 10b and 10c. The cycler 20d also provides a recirculation cap 66 having an internal fluid lumen or path for connecting to the reusable patient cycler connector 30a and the reusable discharge cycler connector 30b for fluidic closing, as described for systems 10b and 10c.

[0144] The cycler 20d of system 10d is also similar to the cycler 20a of system 10a, and under the control of the control unit 50, a less precise gear, centrifugal or other type of pump, here two gear or other pumps 42a and 42b may be used. The cycler 20d also provides volumetric measuring chambers 82a and 82b having a flexible membrane similar to the equilibrium chambers 72a and 72b of the cycler 20c. However, in Figure 4, in contrast to the dual fluid of the third main embodiment, fresh or used PD fluid is delivered and removed from one side of the volumetric measuring chamber membrane, while air is moved back and forth on the other side of the membrane. In one embodiment, during the filling stage, a gear pump 42a is used to draw fresh PD fluid from at least one of the PD fluid containers 102a and 102c and deliver the fluid to one of the volumetric measuring chambers 82a and 82b, while a gear pump 42b delivers fresh fluid to the patient from the other of the volumetric measuring chambers 82a and 82b. During the discharge phase, the gear pump 42b is used instead to draw the used PD fluid from the patient and deliver this fluid to one of the volume measurement chambers 82a and 82b, while the gear pump 42a delivers the used PD fluid from the other of the volume measurement chambers 82a and 82b and discharges it through the discharge port 30b.

[0145] The other side of the membranes in volume measurement chambers 82a and 82b is sequentially filled with air, and the air is purged from the chambers. The air side of volume measurement chambers 82a and 82b communicates with the air circuit 80 by air pressure. The air circuit 80 in the illustrated embodiment includes two air valves 32o and 32p, each under the control of the control unit 50.

[0146] In one embodiment, air valves 32o and 32p are closed during the procedure to lock the volume of air in the volume measuring chambers 82a and 82b (different locked volumes are possible, as the volume depends on the position of the membrane when valve 32o or 32p is closed). When one of the chambers 82a or 82b is filled with fresh or used PD fluid, the corresponding pressure sensors 146a or 146b measure the pressure rise. The control unit 50 of system 10d knows the pressure profile and stops filling with PD fluid at a predetermined pressure value. The flow rate may be lowered at the end of the chamber filling stroke to more easily detect the switching point and minimize the risk of high pressure in the chamber 82a or 82b during operation. For example, both air valves 32o and 32p may be opened during thermal cleaning to allow both the PD fluid sides of the volume measuring chambers 82a and 82b to be filled with, for example, heated fresh PD thermal cleaning fluid. The vent valve 32p is opened while the air valve 32o is closed, allowing the membrane in the volume measurement chamber 82a to move as needed without correspondingly moving the membrane in the volume measurement chamber 82b.

[0147] In the illustrated embodiment, the cycler 20d includes a number of three-way valves under the control of the control unit 50, which control the PD fluid and heat the flow of the cleaning fluid. A first three-way valve 132c is located upstream of the gear or other type of pump 42a and is dedicated to directing fresh PD fluid (from the heater 36) to the volume measurement chamber 82a or 82b (depending on the phase) or to using PD fluid (from the patient) from there. A second three-way valve 132d is located downstream of the gear pump 42a and is dedicated to directing fresh PD fluid to the volume measurement chambers 82a and 82b or to using used PD fluid from there. A third three-way valve 132e is located upstream of the gear pump 42b and is used to direct fresh PD fluid from the volume measurement chambers 82a and 82b or used PD fluid to the volume measurement chamber. A fourth three-way valve 132f is located downstream of the gear pump 42b and is dedicated to guiding fresh PD fluid to the patient, guiding used PD fluid away from the patient, and guiding the discharge of air and / or fresh PD fluid during the priming or air removal phase. A fifth three-way valve 132g is provided, for example, to move back and forth between the first volumetric measuring chamber 82a and the second volumetric measuring chamber 82b during thermal washing.

[0148] In the illustrated embodiment, the pressure sensor 46 is positioned between the downstream pump 42b and the reusable patient cycler connector 30a and outputs to the control unit 50 to control the patient pressure as described herein. Furthermore, pneumatic sensors 146a and 146b are provided to detect the pneumatic pressure on the "dry" side of the membranes of the first and second volumetric measuring chambers 82a and 82b, respectively, which reflect the fresh and used PD fluid pressures on the other side of the membranes. The control unit 50 may, for example at the start of a procedure, compare the readings from pressure sensors 146a and 146b and pressure sensor 46 to confirm that the pressure sensors are measuring the same pressure. If not, the control unit 50 may determine that one of the pressure sensors 146a, 146b, or 46 has drifted and cause a service notification to be posted to the user interface 58 of the APD cycler 20d.

[0149] After the procedure, with the heat cleaning loop closed as described in relation to cycler 20b (with PD fluid lines 24a to 24c connected to the cycler and recirculation cap 66 closed), the control unit 50 performs a heat cleaning (e.g., thermal disinfection or thermal sterilization) sequence on cycler 20d, for example, using heated fresh PD fluid, pumping in multiple directions and switching valves as needed. During heat cleaning, cycler 20d may switch each three-way valve 132c to 132g multiple times to ensure that the heat cleaning fluid comes into contact with each path of the cycler's closed heat cleaning loop. The heat cleaning (e.g., thermal disinfection or thermal sterilization) sequence of system 10d continues until a sufficient heat cleaning dose (e.g., dose A0) is provided to adequately sterilize each treatment fluid line forming the closed heat cleaning loop supplied to cycler 10d.

[0150] Referring here to Figure 5, another alternative APD system 10e and associated methodology of this disclosure includes an APD machine or cycler 20e including a housing 22. System 10e includes all the structures, functions and alternative forms described above for cycler 20d of system 10d, including all valve and pump sequences for the procedures and thermal cleaning procedures (including connections for closing the thermal cleaning loop) described above for cycler 20d. The cycler 20e adds a flow sensor 90 that outputs to a control unit 50 to track the amount of fresh and used PD fluid delivered to and taken out of the patient. The goal of cycler 20d of system 10e is to rely on the accuracy of the stroke-by-stroke volume measurement chambers 82a and 82b, so that the control unit 50 counts the number of strokes to determine the total volume of fresh and used PD fluid delivered. However, if the accuracy per stroke of the volume measurement chambers 82a and 82b is found to be insufficiently accurate, an additional flow sensor 90 may be used, the output of which is integrated over time by the control unit 50 to determine the overall fresh and used PD volume delivered and the resulting removal of patient body fluids (e.g., UF).

[0151] In Figure 5, the flow sensor 90 is located elsewhere. If the flow sensor is a unidirectional flow sensor, it may be positioned upstream of the three-way valve 132c so that it sees only fresh PD fluid, helping to maintain accuracy by preventing the accumulation of proteins and other substances from the patient on its surface. Here, the control unit 50 is intended to monitor the flow of fresh PD fluid related to the movement of the membranes in the volumetric measurement chambers 82a and 82b. A specific membrane movement during the patient filling phase correlates with a specific fresh PD fluid flow rate measured by the flow sensor 90. The same membrane movement during the patient discharge phase, where the flow sensor 90 is not used, can be assumed to result in the same used PD flow rate (or the extrapolated flow rate may correlate with a different membrane movement). In either case, the discharge flow can be determined based on measurements performed during the filling phase. If the flow sensor 90 is a bidirectional flow sensor, it may be positioned downstream of the three-way valve 132c so that the flow sensor can measure fresh and used PD flow rates in multiple directions (dashed line).

[0152] Referring here to Figure 6, a further alternative APD system 10f and related methodology of this disclosure includes an APD machine or cycler 20f including a housing 22. System 10f includes all the structures, functions and alternative forms described above for cycler 20d, including all valve and pump sequences for the treatment and thermal cleaning procedures (including connections for closing the thermal cleaning loop) described for cycler 20d. System 10f also includes a flow meter 90 outputting to a control unit 50, which is again provided to track the amount of fresh and used PD fluid delivered to and taken out of the patient. The cycler 20f adds additional three-way valves 132h and 132i and associated fluid lines so that the PD fluid can flow in the same direction through the flow sensor 90, regardless of whether the PD fluid is fresh or used. The cycler 20f of system 10f increases the number of different flow sensors 90 that may be used, since not all flow sensors are bidirectional.

[0153] A seventh embodiment, not shown, may use any of the same general flow paths as the cyclers 20d to 20f of systems 10d to 10f, but the driving force is air, which may be supplied from positive and negative tanks pressurized via pneumatic pumps under the control of control unit 50. The tanks may supply positive and negative pneumatic regulators, respectively, which provide regulated positive and negative air pressures to, for example, electronically controlled pneumatic solenoid valves that drive the membrane fluid pump and valves. The advantage is that the membrane fluid pump is reusable and can be calibrated with high precision in production. Also, the membrane pump chamber may be relatively large, which should result in less frequent operation of the membrane fluid valves that can be operated by the membrane fluid pump, and thus improved reliability.

[0154] It should be understood that various modifications and changes to the currently preferred embodiments described herein will be obvious to those skilled in the art. Therefore, such modifications and changes are intended to be covered by the appended claims. For example, while thermal cleaning (e.g., thermal disinfection or thermal sterilization) is disclosed, chemical cleaning, such as citric acid, may be provided instead of, or in addition to, thermal cleaning. There may be chemical advantages to using used dialysate as a cleaning fluid. Other types of disinfection, such as ultraviolet light, may also be used. Furthermore, while system 10c in Figure 3 is described as using RO water as its process fluid, air or a different process fluid may be used as an alternative. Additionally, while systems 10d to 10f in Figures 4 to 6 are described as using air as its compressible fluid, other gases or compressible fluids may be used as an alternative.

Claims

1. A peritoneal dialysis ("PD") system, Housing and A dialysate pump, which includes a reusable pump body housed in the aforementioned housing and receiving PD fluid for pressurization, A dialysate inline heater, which includes a reusable heater body housed in the aforementioned housing and receiving PD fluid for heating, The patient line connector presented by the housing, The discharge line connector presented by the housing, A first reusable PD fluid line includes a first connector extending from the housing and configured to mate with the patient line connector for a heat cleaning sequence, and a first PD fluid container for PD treatment, A second reusable PD fluid line including a second connector extending from the housing and configured to mate with the discharge line connector for the heat cleaning sequence, and a second PD fluid container for the PD treatment, A control unit configured to execute the heat wash sequence after the PD treatment, wherein the first connector of the first reusable PD fluid line is disconnected from the first PD fluid container and mated with the patient line connector, the second connector of the second reusable PD fluid line is disconnected from the second PD fluid container and mated with the discharge line connector, and the dialysate pump and the dialysate inline heater are operated during the heat wash sequence, and the control unit and A PD system equipped with this feature.

2. The PD system according to claim 1, comprising an additional connector presented by the housing and a third reusable PD fluid line including a third connector extending from the housing and configured to mate with the additional connector for thermal cleaning.

3. The PD system according to claim 2, comprising a fourth fluid line including a fourth connector configured to mate with the additional connector during treatment.

4. The PD system according to claim 3, wherein the fourth fluid line is used to provide a place for storing additional PD fluid or spillage samples for treatment.

5. The PD system according to claim 1, comprising the first and second PD fluid vessels configured to be connected to the first and second connectors, respectively.

6. The PD system according to claim 1, wherein the first and second connectors are different from each other.

7. The PD system according to claim 1, comprising a disposable patient line configured to be connected to the patient line connector, and a disposable discharge line configured to be connected to the discharge line connector.

8. The PD system according to claim 1, wherein at least one of the first or second reusable PD fluid lines is provided with one or more covers, the one or more covers being opened and closed to disconnect and connect the first connector to and from the patient line connector, or the second connector to and from the discharge line connector, respectively.

9. The PD system according to claim 1, wherein the control unit is configured to (i) cause the dialysate inline heater to heat the PD fluid to at least 70°C or at least 120°C for a sterilization level of thermal washing, and (ii) cause the dialysate pump to recirculate the heated PD fluid during the thermal washing sequence.

10. The PD system according to claim 1, wherein the dialysate pump is a piston, gear, or membrane pump, and the reusable pump body of the piston, gear, or membrane pump receives the PD fluid for pressurization.

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