Peritoneal dialysis cycler with thermal cleaning

Abstract

A peritoneal dialysis ("PD") system includes a dialysis fluid pump having a reusable pump body that accepts PD fluid for pumping, a dialysis fluid inline heater including a reusable heater body that accepts 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 run a hot clean (e.g., hot disinfect or hot sterilize) sequence after a PD treatment, 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 drain line connector, and the dialysis fluid pump and possibly the dialysis fluid inline heater are actuated.

Description

[0001] Priority requirements

[0002] This application claims priority and benefit to U.S. Provisional Application No. 63 / 131,442, filed December 29, 2020, entitled “Peritoneal Dialysis Cycler Having Heat Cleaning,” the entire contents of which are incorporated herein by reference and are based. Technical Field

[0003] This disclosure relates generally to medical fluid therapy, and more particularly to dialysis fluid therapy. Background Technology

[0004] The kidneys can fail for various reasons. Kidney failure causes several physiological disorders. The body can no longer balance water and minerals or excrete the daily metabolic load. Toxic metabolic end products (such as urea, creatinine, uric acid, etc.) may accumulate in the patient's blood and tissues.

[0005] Decreased kidney function, and most importantly, kidney failure, is treated with dialysis. Dialysis removes waste, toxins, and excess water from the body that normally functioning kidneys would otherwise remove. Dialysis, a replacement therapy for kidney function, is crucial for many people because it is a life-saving treatment.

[0006] One type of treatment for kidney failure is hemodialysis (“HD”), which typically uses diffusion to remove waste products from a patient’s blood. A diffusion gradient occurs across a semi-permeable dialyzer between the blood and an electrolyte solution (called dialysate or dialysate fluid) to induce diffusion.

[0007] Hemofiltration (“HF”) is an alternative renal replacement therapy that relies on the convective transport of toxins from the patient’s blood. HF is achieved by adding a replacement or displacement fluid to the extracorporeal circuit during treatment. The replacement fluid and the fluid that accumulates in the patient between treatments are ultrafiltered during HF treatment, thus providing a convective transport mechanism that is particularly beneficial in removing medium-sized molecules.

[0008] Hemodiafiltration (“HDF”) is a treatment modality that combines convective and diffusion clearance. Similar to standard hemodialysis, HDF uses dialysate flowing through the dialyzer to provide diffusion clearance. Additionally, a replacement solution is provided directly to the extracorporeal circuit to provide convective clearance.

[0009] Most HD, HF, and HDF treatments occur in centers. There is a growing trend towards home hemodialysis (“HHD”), partly because HHD can be performed daily, offering superior treatment benefits compared to center hemodialysis, which typically occurs every two or three weeks. Studies have shown that more frequent treatments remove more toxins and waste products and result in less inter-dialysis fluid overload compared to patients receiving less frequent but potentially longer treatments. Patients receiving more frequent treatments do not experience as many downcycles (fluid and toxin fluctuations) as center patients, who have accumulated two or three days of toxins before treatment. In some areas, the nearest dialysis center may be many miles from a patient's home, resulting in door-to-door treatment taking up most of the day. Treatment at a center closer to the patient's home can also take up most of the patient's day. HHD can be performed at night or during the day when the patient is relaxing, working, or performing other procedures.

[0010] Another type of treatment for kidney failure is peritoneal dialysis (“PD”), which involves infusing a dialysis solution (also known as dialysate) through a catheter into the patient’s peritoneal cavity. The dialysate comes into contact with the peritoneum in the patient’s peritoneal cavity. Waste, toxins, and excess water enter the dialysate from the patient’s bloodstream through capillaries in the peritoneum and due to diffusion and osmosis (i.e., the osmotic gradient that occurs across the membrane). The osmotic agent in the PD dialysate provides this osmotic gradient. Used or discarded dialysate is drained from the patient, thus removing waste, toxins, and excess water. This cycle is repeated, for example, multiple times.

[0011] Various types of peritoneal dialysis therapies exist, including continuous ambulatory peritoneal dialysis (“CAPD”), automated peritoneal dialysis (“APD”), tidal flow dialysis, and continuous flow peritoneal dialysis (“CFPD”). CAPD is a manual dialysis treatment. Here, the patient manually connects the implanted catheter to the drainage tube to allow used or discarded dialysis fluid to drain from the peritoneal cavity. The patient then switches the fluid connection so that the catheter is connected to a fresh dialysis fluid bag to infuse fresh dialysis fluid into the patient through the catheter. The patient disconnects the catheter from the fresh dialysis fluid bag, allowing the dialysis fluid to remain in the peritoneal cavity, where waste, 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 significant investment of time and effort from the patient, thus leaving considerable room for improvement.

[0012] Automated peritoneal dialysis (“APD”) is similar to CAPD in that the dialysis treatment includes drainage, filling, and retention cycles. However, an APD machine typically performs these cycles automatically while the patient is asleep. The APD machine eliminates the need for patients to manually perform treatment cycles and to transport supplies during the day. The APD machine is fluidly connected to an implanted catheter, a source or bag of fresh dialysis fluid, and a fluid drainage tube. The APD machine pumps fresh dialysis fluid from the source through the catheter and into the patient's peritoneal cavity. The APD machine also allows the dialysis fluid to remain in the cavity and allows the removal of waste, toxins, and excess water. The source may include multiple liters of dialysis fluid, comprising several solution bags.

[0013] The APD machine pumps used or discarded dialysate from the patient's peritoneal cavity through a catheter for drainage. Similar to the manual procedure, several cycles of drainage, filling, and retention occur during dialysis. The "final filling" can occur at the end of an APD treatment. The final filling fluid can be retained in the patient's peritoneal cavity until the next treatment begins, or it can be manually emptied at some point during the day.

[0014] In any of the aforementioned models of using automated machines, the machines typically operate using disposable kits that are discarded after a single use. Depending on the complexity of the disposable kit, the cost of using one kit per day can become very high. Additionally, the need for storage space for daily disposable supplies can be a hassle for homeowners and businesses. Furthermore, daily replacement of disposable items requires patients or caregivers to spend time and effort at home or in the clinic every day.

[0015] For each of the above reasons, the goal is to provide an APD machine that reduces single-use waste. Summary of the Invention

[0016] Typically, known automated peritoneal dialysis (“PD”) systems include a machine or circulator that receives and actuates a pump cartridge having rigid parts and flexible parts that deformable to perform pumping and valve adjustment operations. The rigid parts are attached to tubing extending into various bags. The aforementioned disposable cartridges and associated tubing and bags can be cumbersome for patients at home to load for treatment. The sheer number of disposable items can also result in multiple setup procedures requiring input from the patient, potentially exposing room for error.

[0017] On the other hand, the APD system and associated methods of this disclosure convert a large portion of the fluid transport portion of the APD system into reusable components that are thermally cleaned after treatment. Fluid tubing within the machine or circulator is reused. Remaining disposable items may include patient tubing and drainage tubing, dialysis fluid containers or bags, and possibly additional dialysis fluid containers and tubing or tubing extending from the containers to the APD circulator.

[0018] The APD system disclosed herein includes an APD circulator with a housing. At least one, and possibly three or more, reusable PD fluid lines extend from the housing. In one embodiment, when not connected to a PD fluid container or bag, the reusable PD fluid lines are connected to a patient line circulator connector, a drainage line circulator connector, and an additional circulator connector that can be used to connect a fourth dialysis fluid container or bag to the circulator.

[0019] In another embodiment, when not connected to a PD fluid container or bag, the reusable PD fluid tubing is connected to a dedicated thermal cleaning connector. In either embodiment, the reconnected PD fluid tubing forms a closed loop that allows for thermal cleaning after treatment. It is envisioned to use residual dialysis fluid as the thermal cleaning fluid and heat it to a sterilization temperature, for example, between 70°C and 130°C, such as 70°C for sterilization or 120°C and higher for sterilization.

[0020] Reusable PD fluid lines can be color-coded and / or keyed to match the color-coded or keyed connectors of the PD fluid containers or bags. Containers or bags can hold dialysis fluids with different levels of dextran or glucose, such as 1.36% glucose dialysis fluid, 2.27% glucose dialysis fluid, and / or PD fluids of different formulations (such as icodextrin) in the final bag.

[0021] Inside the housing, in the first primary embodiment, reusable tubing extends from each of the reusable dialysis fluid lines through a dialysis fluid line valve for each line and to a dialysis fluid inline heater. In an embodiment, any valve in the APD circulator may be an electrically actuated solenoid valve with a reusable valve body that is closed (e.g., when not energized) or open (e.g., when energized) to allow PD fluid to flow through the body. Alternatively, a bistable valve may be used. In one embodiment, the dialysis fluid inline heater is also electrically actuated and is, for example, a resistance heater with a reusable heater body that receives PD fluid for heating. In an embodiment, the inline heater is capable of heating the PD fluid from room temperature to body temperature, such as 37°C, at a flow rate of at least 300 ml / min. A temperature sensor is located near the heater, for example, downstream of the heater, to provide feedback for temperature control.

[0022] Reusable tubing extends from the outlet of the dialysis fluid inline heater to a flow meter dedicated to draining used dialysis fluid. Any tubing within the circulator housing can 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 dialysis fluid pump is located between a dedicated drainage flow meter and a dedicated filler flow meter that measures the flow rate of fresh dialysis fluid to the patient. The reusable pump includes a reusable pump body that receives PD fluid for pumping. That is, the pump does not require PD fluid to flow within a disposable object such as tubing or a cartridge. The PD fluid pump can be an electrically operated piston pump, diaphragm pump, gear pump, or centrifugal pump, which can be inherently volumetally accurate, thus eliminating the need for separate PD fluid volume measurement devices, such as equilibration chambers or devices using the ideal gas law. The provision of filler flow meters and drainage flow meters allows for less precise, reusable PD fluid pumps, such as gear pumps, centrifugal pumps, or other types of pumps. In any case, the PD fluid pump can be controllable to pump to and from the patient at or below pressure limits by controlling the level of current, voltage, or voltage pulse sequences supplied to it. Positive patient pressure limits can be, for example, 1 to 5 psig. Negative pressure limits can be, for example, -1.5 psig to -3.0 psig. In one embodiment, the PD fluid pump is bidirectional and continuous, allowing for the provision of a single pump.

[0023] The first primary embodiment includes an air trap in one embodiment, which may be located at different locations along the main dialysis fluid line or pump line. In one embodiment, the air trap is located between a dedicated filler flow meter and a reusable PD fluid pump. An vent valve may be located on top of the air trap to vent air from the air trap for drainage. In an embodiment, one or more level sensors are located near the air trap so that PD fluid at a desired level or level range can be maintained in the air trap.

[0024] For the first primary embodiment, a pressure sensor is located downstream of a dedicated filler flow meter, between the filler flow meter and a disposable patient line. The disposable patient line connects to a patient connector provided by the circulator's housing. A durable, reusable tubing extends from the patient connector along the tubing inside the housing to the dedicated filler flow meter. The pressure sensor can be positioned along this tubing and outputs positive and negative patient pump pressure signals used to ensure that patient pump pressure limits are not exceeded. One or more sterile filters may be located within 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 straight-through filter without a rejection line. The pore size of the sterile filter may be, for example, less than one micrometer, such as 0.1 or 0.2 micrometers.

[0025] In one embodiment, the drainage line is also disposable and is connected during treatment to a drainage line connector extending from the housing of the APD circulator. In addition to the vent valve and the valve provided for each of the dialysis fluid lines, an additional valve may be located upstream of the inline heater, adjacent to the patient line connector, adjacent to the drainage line connector, and adjacent to an additional connector for connecting a fourth dialysis fluid container or bag to the circulator.

[0026] After treatment, the patient tubing, drainage tubing, and tubing connected to the additional connector are removed and discarded. The PD fluid container or bag is removed from the reusable PD fluid tubing. The reusable PD fluid tubing is then reconnected to the patient tubing connector, drainage tubing connector, and additional connector. The APD circulator and reusable PD fluid tubing are now fluid-closed, allowing a thermal cleaning fluid, such as heated fresh PD fluid, to be pumped multiple times in one or more directions through the closed thermal cleaning loop to thermally clean (e.g., thermally sterilize or disinfect) the internal tubing, internal components (heaters, air traps, pumps, flow meters, valves, etc.) and reusable PD fluid tubing for the next treatment.

[0027] The APD circulation device of the disclosed APD system includes a control unit having one or more processors and one or more memories, which receive signals or outputs from flow meters, one or more pressure sensors, and one or more temperature sensors, and process these signals or outputs as feedback. The control unit uses pressure feedback to control the dialysis fluid pump to operate at safe patient pressure limits during treatment and at safe system limits during thermal cleansing. The control unit uses temperature feedback to control the dialysis fluid heater to heat fresh dialysis fluid to, for example, body temperature. The control unit may also integrate flow meter signals 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.

[0028] The control unit also opens and closes the dialysis fluid valve, as well as the dialysis fluid pump and heater, to run a pre-infusion sequence, a patient filling sequence, a patient drainage sequence, and a thermal cleaning (e.g., thermal sterilization) sequence after PD treatment, wherein each of the at least one reusable PD fluid line is connected to one of the line connectors, as discussed above. The control unit described above is provided for each of the alternative main embodiments discussed herein.

[0029] In the second primary embodiment, the reusable PD fluid tubing is not inserted into the patient tubing connector and drainage tubing connector, but instead into their own dedicated connectors for thermal cleaning. The patient tubing connector and drainage tubing connector are instead equipped with dedicated recirculation caps, which are fitted onto the connectors after treatment for thermal cleaning. The second primary embodiment replaces the flow meter of the first primary embodiment with a piston pump that is inherently highly volumetrically accurate. The accuracy of the piston pump can be checked using a dialysis fluid inline heater. Here, at the start of each patient filling, the first few milliliters of fresh PD fluid are pumped through the heater without heating the fluid. A first temperature measurement T1 is performed. The heater is turned on, and the pneumatic force required to raise the temperature to T2 (e.g., the filling temperature of 37°C) is used to measure the PD fluid flow rate. That is, the specific heat capacity of water is referred to as the temperature increment (T2-T1), which the system control unit uses to convert the heating effect (energy / time) into flow rate (mass / time). If the difference between the value calculated by the control unit as the fluid pump has pumped and the value determined via the heater exceeds a limit, the fluid pump is recalibrated.

[0030] Similar to the second principal embodiment, the third principal embodiment provides a dedicated connector for the reusable PD fluid line, a recirculation cap for the patient connector and drainage line connector, and a high-precision piston pump. The third principal embodiment separates the internal reusable tubing within the circulator housing into a PD fluid line and an operating fluid line, wherein the operating fluid line is filled with different operating fluids, such as reverse osmosis (“RO”) water. Advantageously, the RO water can also be used as a flushing flow for the piston pump.

[0031] The PD fluid line and the operating fluid line are separated by a flexible membrane housed in a pair of balancing chambers. The operating fluid drives one side of each balancing chamber in a loop that includes a piston pump and an air trap to ensure sufficient operating fluid is available for each stroke. In each stroke, the RO pump (i) draws RO water from one balancing chamber, causing an equal volume of fresh or used dialysis fluid to enter the balancing chamber on the other side of the flexible membrane, and (ii) delivers RO water to the other balancing chamber, causing an equal volume of fresh or used dialysis fluid to exit the balancing chamber on the other side of the flexible membrane. Therefore, the balancing chambers provide an additional layer of accuracy should the piston pump become inaccurate for any reason.

[0032] The third primary embodiment includes multiple fluid valves for sequencing the balancing chambers and for directing desired fresh or used PD fluid from a desired source to a desired destination. In this embodiment, the balancing chambers are alternated, such that fresh or used PD fluid flows to or from the patient, respectively, during treatment. A fluid pump causes RO water to sequence the balancing chambers to move the heated PD fluid around the PD fluid thermal cleaning circuit. The same RO water can be used for multiple treatments and can be replaced at regular maintenance intervals.

[0033] The fourth principal embodiment is similar to the second and third principal embodiments because it provides a dedicated connector for the reusable PD fluid line and a recirculation cap for the patient connector and drainage line connector. The fourth principal embodiment is also similar to the first principal embodiment because less precise gear pumps, centrifugal pumps, or other types of pumps can be used; here, two gear pumps or other pumps are used. The fourth principal embodiment also provides a volumetric chamber with a flexible membrane, similar to the balancing chamber of the third principal embodiment. However, here, fresh or used PD fluid is delivered and removed from one side of the volumetric chamber membrane while air moves back and forth on the other side of the membrane, which is the opposite of the dual-fluid configuration of the third principal embodiment. In one embodiment, one of the gear pumps, centrifugal pumps, or other types of pumps is dedicated to delivering fresh or used PD fluid to the volumetric chamber (from the PD fluid container or the patient, respectively), while the second gear pump or other pump is dedicated to removing fresh or used PD fluid from the volumetric chamber (to the patient or drainage line, respectively).

[0034] In one embodiment, a fourth embodiment provides multiple three-way valves to control 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 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 chamber. The second three-way valve determines whether PD fluid is delivered to either the first or second volume chamber within the volume 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 chamber. The third three-way valve determines whether PD fluid is removed from either the first or second volume 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 chamber. The fourth three-way valve determines whether fresh PD fluid is delivered to the patient or used PD fluid is delivered to a drainage tube. A fifth three-way valve is provided for circulating between the first and second volume chambers, for example, during thermal cleaning.

[0035] In one embodiment, one or more pressure sensors are provided to sense the air pressure on the "dry" side of each diaphragm in the first and / or second volume chambers, which reflects the PD fluid pressure on the other side of the diaphragm. With pressure sensors provided for each volume chamber, the control unit can compare readings from the two sensors, for example, at the start of treatment, to confirm that the pressure sensors are measuring the same pressure. If not, the control unit can determine that one of the pressure sensors has drifted and cause a maintenance notification to be posted on the APD circulator's user interface. In one embodiment, additional pressure sensors are added along the patient tubing to provide feedback to ensure that both positive and negative patient pump pressures are within safe limits.

[0036] The fifth embodiment begins with the structure of the fourth embodiment and adds a flow sensor to track the volume of fresh and used PD fluid delivered to and removed from the patient. The goal of the fourth main embodiment was to rely on the accuracy of the volumetric chamber on a per-stroke basis and to count the number of strokes to determine the total volume of fresh and used PD fluid delivered. However, if the per-stroke accuracy of the volumetric chamber is found to be insufficient, an additional flow sensor can be used, in which its output is integrated over time to determine the total volume of fresh and used PD. In one embodiment, the flow sensor is placed in a location such that it can sense the flow rate of both fresh and used PD fluid.

[0037] The sixth embodiment begins with the structure of the fifth embodiment and includes a flow sensor, which is again provided for tracking the volume of fresh and used PD fluid delivered to and removed from the patient. The sixth embodiment adds one or more valves and fluid lines such that the PD fluid flows through the sensor in the same direction, regardless of whether the PD fluid is fresh or used. The sixth embodiment expands the number of different flow sensors that can be used, since not all flow sensors are bidirectional.

[0038] The seventh embodiment can have the same overall flow path as the previous embodiments, but in which the driving force for the diaphragm fluid pump and valve is air. The advantage here is that the diaphragm fluid pump is reusable and can be calibrated to high precision in production. Additionally, the fluid pump chamber can be relatively large, allowing for less frequent actuation of the associated diaphragm valve, which in turn improves reliability.

[0039] Based on the disclosure set forth herein, and without limiting this disclosure in any way, in a first aspect that may be combined with any other aspect or part thereof described herein, a peritoneal dialysis (“PD”) system includes: a housing; a dialysis fluid pump housed within the housing and including a reusable pump body receiving PD fluid for pumping; a dialysis fluid inline heater housed within the housing and including a reusable heater body receiving PD fluid for heating; a patient line connector provided by the housing; a drainage line connector provided by the housing; and a first reusable PD fluid... The device includes a body tubing extending from the housing and including a first connector configured to mate with a patient tubing connector; a second reusable PD fluid tubing extending from the housing and including a second connector configured to mate with a drainage tubing connector; and a control unit configured to run a thermal cleansing sequence after PD treatment, wherein the first connector of the first reusable PD fluid tubing mates with the patient tubing connector, the second connector of the second reusable PD fluid tubing mates with the drainage tubing connector, and wherein, during the thermal cleansing sequence, a dialysis fluid pump and optionally a dialysis fluid inline heater are actuated.

[0040] In a second aspect, which may be combined with any other aspect or part thereof described herein, the PD system includes an additional connector provided by the housing and a third reusable PD fluid line extending from the housing, the third reusable PD fluid line including a third connector configured to mate with the additional connector for thermal cleaning.

[0041] In a third aspect, which may be combined with any other aspect or part thereof described herein, the PD system includes a fourth fluid line comprising a fourth connector configured to mate with an additional connector during treatment.

[0042] In a fourth aspect, which may be combined with any other aspect or part thereof described herein, the fourth fluid line is used to provide additional PD fluid for treatment or to provide a location for storing effluent samples.

[0043] In a fifth aspect, which may be combined with any other aspect or part thereof described herein, the PD system includes first and second PD fluid containers configured for connection to first and second connectors, respectively.

[0044] In a sixth aspect, which can be combined with any other aspect or part thereof described herein, the first and second connectors are different from each other.

[0045] In a seventh aspect, which may be combined with any other aspect or part thereof described herein, PD includes a disposable patient line configured for connection to a patient line connector and a disposable drainage line configured for connection to a drainage line connector.

[0046] In an eighth aspect, which may be combined with any other aspect or part thereof described herein, at least one of the first or second reusable PD fluid lines is provided with one or more caps that are opened and closed to disconnect a first connector from a patient line connector and connect the first connector to a patient line connector, or to disconnect a second connector from a drainage line connector and connect the second connector to a drainage line connector.

[0047] In a ninth aspect, which may be combined with any other aspect or part thereof described herein, 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 to achieve a sterilization level for thermal cleaning; and (ii) cause the dialysate pump to recirculate the heated PD fluid during the thermal cleaning sequence.

[0048] In a tenth aspect, which may be combined with any other aspect or part thereof described herein, the dialysis fluid pump is a piston pump, gear pump, or diaphragm pump, the reusable pump body of which receives PD fluid for pumping.

[0049] In an eleventh aspect, which may be combined with any other aspect or part thereof described herein, a peritoneal dialysis (“PD”) system includes: a housing; a dialysis fluid pump housed within the housing and including a reusable pump body receiving PD fluid for pumping; a dialysis fluid inline heater housed within the housing and including a reusable heater body receiving PD fluid for heating; a patient line connector provided by the housing, the patient line connector including a patient line recirculation cap that allows PD fluid to recirculate through the patient line connector when the patient line connector is sealed by the patient line recirculation cap; and a drainage line connector provided by the housing, the drainage line connector including a drainage line recirculation cap that allows PD fluid to recirculate through the drainage line connector when the drainage line connector is sealed by the drainage line recirculation cap. When the patient line recirculation cap is closed, the drainage line recirculation cap allows PD fluid to be recirculated through the drainage line connector; at least one reusable PD fluid line; at least one thermal cleaning 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 run a thermal cleaning sequence after PD treatment, wherein the patient line connector is closed by the patient line recirculation cap, wherein the drainage line connector is closed by the drainage line recirculation cap, wherein each of the at least one reusable PD fluid lines is connected to one of the at least one thermal cleaning connectors, and wherein, during the thermal cleaning sequence, at least one of the dialysis fluid pump or the dialysis fluid inline heater is actuated.

[0050] In a twelfth aspect, which may be combined with any other aspect 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 PD fluid heated by a heater under the control of the control unit; and compare the first PD fluid flow rate determination with a second PD fluid flow rate determination based on a corresponding actuation of the dialysate pump.

[0051] In a thirteenth aspect, which may be combined with any other aspect or part thereof described herein, the PD system includes at least one cover positioned and arranged to releasably and sealingly enclose the at least one thermal cleaning connector during a thermal cleaning sequence.

[0052] In the fourteenth aspect, which may be combined with any other aspect or part thereof described herein, at least one of the patient line recirculation cap or drainage line recirculation cap includes an internal channel for recirculation.

[0053] In a fifteenth aspect, which may be combined with any other aspect or part thereof described herein, the PD system includes at least one PD fluid container configured to receive one of the at least one reusable PD fluid lines.

[0054] In a sixteenth aspect, which may be combined with any other aspect or part thereof described herein, the PD system includes a disposable patient line configured for connection to a patient line connector and a disposable drainage line configured for connection to a drainage line connector.

[0055] In a seventeenth aspect, which may be combined with any other aspect or part thereof described herein, 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 to achieve a sterilization level for thermal cleaning; and (ii) cause the dialysate pump to recirculate the heated PD fluid during a thermal cleaning sequence.

[0056] In the eighteenth aspect, which may be combined with any other aspect or part thereof described herein, the dialysis fluid pump is a piston pump, gear pump, or diaphragm pump, the reusable pump body of which receives PD fluid for pumping.

[0057] In a nineteenth aspect, which may be combined with any other aspect or part thereof described herein, a peritoneal dialysis (“PD”) system includes: a housing; a patient line connector provided by the housing, the patient line connector including a patient line recirculation cap that, when the patient line connector is sealed by the patient line recirculation cap, allows PD fluid to recirculate through the patient line connector; a drainage line connector provided by the housing, the drainage line connector including a drainage line recirculation cap that, when the drainage line connector is sealed by the drainage line recirculation cap, allows PD fluid to recirculate through the drainage line connector; at least one reusable PD fluid line; at least one thermally cleanable connector supported by the housing and configured to receive the at least one reusable PD fluid line; at least one fixed-volume chamber including a flexible membrane separating the process fluid side of the chamber from the PD fluid side of the chamber; process A fluid pump configured to pump process fluid to and from the process fluid side of the at least one fixed volume chamber, respectively discharging PD fluid from the PD fluid side of the at least one fixed volume chamber and drawing PD fluid into the PD fluid side of the at least one fixed volume chamber; a dialysis fluid inline heater housed in a housing and in fluid communication with the PD fluid side of the at least one fixed volume chamber; and a control unit configured to run a thermal cleaning sequence after PD treatment, wherein the patient line connector is capped with a patient line recirculation cap, wherein the drainage line connector is capped with a drainage line recirculation cap, wherein each of the at least one reusable PD fluid lines is connected to one of the at least one thermal cleaning connectors, and wherein, during the thermal cleaning sequence, the process fluid pump and optionally the dialysis fluid inline heater are actuated.

[0058] In a twentieth aspect, which may be combined with any other aspect or part thereof described herein, the dialysis fluid inline heater is selectively fluidly connected to the PD fluid side of the at least one fixed volume chamber via at least one valve.

[0059] In a twenty-first aspect, which may be combined with any other aspect or part thereof described herein, the at least one fixed volume chamber includes first and second fixed volume chambers, each chamber including 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 wherein a process fluid pump is positioned and arranged to pump process fluid to the process fluid side of one of the first or second chambers while pumping process fluid out of the other of the first or second chambers.

[0060] In the twenty-second aspect, which may be combined with any other aspect or part thereof described herein, the process fluid is water or air.

[0061] In the twenty-third aspect, which may be combined with any other aspect or part thereof described herein, the process fluid pump is a piston pump, and wherein the process fluid is additionally used as the flushing fluid for the piston pump.

[0062] In a twenty-fourth aspect, which may be combined with any other aspect or part thereof described herein, 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 wherein the process fluid circuit includes a storage chamber for storing additional amounts of process fluid.

[0063] In a twenty-fifth aspect, which may be combined with any other aspect or part thereof described herein, the dialysis fluid inline heater is located between the at least one reusable PD fluid line and the PD fluid side of the at least one fixed volume chamber.

[0064] In a twenty-sixth aspect, which may be combined with any other aspect or part thereof described herein, the PD system includes a first valve and at least one second valve, the first valve being located between each of the at least one reusable PD fluid lines and a dialysate inline heater, and the at least one second valve being located between the dialysate inline heater and the PD fluid side of each of the at least one fixed volume chambers.

[0065] In a twenty-seventh aspect, which may be combined with any other aspect or part thereof described herein, the patient line connector, when sealed by the patient line recirculation cap, (i) is in fluid communication with a fresh or used PD fluid line extending from the PD fluid side of each of the at least one fixed volume chamber, and (ii) is in fluid communication with a thermal cleaning line extending to each of the at least one thermal cleaning connector.

[0066] In a twenty-eighth aspect, which may be combined with any other aspect or part thereof described herein, the patient line connector, when opened by the patient line recirculation cap, (i) is in fluid communication with a fresh or used PD fluid line extending from the PD fluid side of each of the at least one fixed volume chamber and (ii) is in fluid communication with a disposable patient line.

[0067] In a twenty-ninth aspect, which may be combined with any other aspect or part thereof described herein, the drain line connector, when sealed by the drain 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 (ii) is in fluid communication with the thermal cleaning line extending to each of the at least one thermal cleaning connector.

[0068] In a thirtieth aspect, which may be combined with any other aspect or part thereof described herein, the drainage line connector, when opened 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 with the disposable drainage line.

[0069] In a thirty-first aspect, which may be combined with any other aspect or part thereof described herein, a peritoneal dialysis (“PD”) system includes: a housing; a patient line connector provided by the housing, the patient line connector including a patient line recirculation cap that, when the patient line connector is sealed by the patient line recirculation cap, allows PD fluid to recirculate through the patient line connector; a drainage line connector provided by the housing, the drainage line connector including a drainage line recirculation cap that, when the drainage line connector is sealed by the drainage line recirculation cap, allows PD fluid to recirculate through the drainage line connector; at least one reusable PD fluid line; at least one thermally cleanable connector supported by the housing and configured to receive the at least one reusable PD fluid line; and at least one fixed-volume chamber including a compressible fluid side of the chamber connected to the chamber. The system comprises: a flexible membrane separated from the PD fluid side; at least one PD fluid pump configured to pump PD fluid to and from the PD fluid side of the at least one fixed volume chamber, to pressurize and depressurize the compressible fluid, respectively; a dialysate inline heater housed in a housing and in fluid communication with the PD fluid side of the at least one fixed volume chamber; and a control unit configured to run a thermal cleaning sequence after PD treatment, wherein the patient line connector is capped with a patient line recirculation cap, wherein the drainage line connector is capped with a drainage line recirculation cap, wherein each of the at least one reusable PD fluid lines is connected to one of the at least one thermal cleaning connectors, and wherein, during the thermal cleaning sequence, the PD fluid pump and optionally the dialysate inline heater are actuated.

[0070] In a thirty-second aspect, which may be combined with any other aspect or part thereof described herein, the dialysis fluid inline heater is selectively fluidly connected to the PD fluid side of the at least one fixed volume chamber via at least one valve.

[0071] In a thirty-third aspect, which may be combined with any other aspect or part thereof described herein, 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 wherein the at least one PD fluid pump is positioned and arranged to pump PD fluid to the PD fluid side of one of the first or second chambers while pumping PD fluid out of the other of the first or second chambers.

[0072] In a thirty-fourth aspect, which may be combined with any other aspect or part thereof described herein, the PD system includes a compressible fluid loop extending between a compressible fluid side of a first fixed volume chamber and a compressible fluid side of a second fixed volume chamber, the compressible fluid loop (i) enabling compressible fluid pushed from one of the compressible fluid sides to enter the other compressible fluid side, or (ii) enabling compressible fluid to be discharged into the atmospheric environment.

[0073] In the thirty-fifth aspect, which may be combined with any other aspect or part thereof described herein, the compressible fluid is air.

[0074] In a thirty-sixth aspect, which may be combined with any other aspect or part thereof described herein, the at least one PD fluid pump comprises first and second PD fluid pumps, each positioned and arranged to pump fresh and used PD fluid into or out of the at least one fixed volume chamber.

[0075] In a thirty-seventh aspect, which may be combined with any other aspect 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 direct fresh or used PD fluid to a first or second fixed volume chamber; (ii) a second three-way valve positioned and arranged to direct fresh or used PD fluid to the first or second fixed volume chamber; (iii) a third three-way valve positioned and arranged to direct fresh PD fluid from the first or second fixed volume chamber and to direct used PD fluid to the first or second fixed volume chamber; (iv) a fourth three-way valve positioned and arranged to direct fresh PD fluid to or from the patient line connector and to direct used PD fluid or air or fresh PD fluid to a drainage line connector; or (v) a fifth three-way valve positioned and arranged to switch back and forth between the first or second fixed volume chamber during a thermal cleaning sequence.

[0076] In the thirty-eighth aspect, which may be combined with any other aspect or part thereof described herein, the dialysis fluid inline heater is located between the at least one reusable PD fluid line and the PD fluid side of the at least one fixed volume chamber.

[0077] In a thirty-ninth aspect, which may be combined with any other aspect or part thereof described herein, the patient line connector, when sealed by the patient line recirculation cap, (i) is in fluid communication with a fresh or used PD fluid line, and (ii) is in fluid communication with a thermal cleaning line extending to each of the at least one thermal cleaning connector.

[0078] In the fortieth aspect, which may be combined with any other aspect or part thereof described herein, the patient line connector, when opened by the patient line recirculation cap, (i) is in fluid communication with a fresh or used PD fluid line and (ii) is in fluid communication with a disposable patient line.

[0079] In a forty-first aspect, which may be combined with any other aspect or part thereof described herein, the drain line connector, when sealed by the drain line recirculation cap, (i) is in fluid communication with the used PD fluid line and (ii) is in fluid communication with the thermal cleaning line extending to each of the at least one thermal cleaning connector.

[0080] In the forty-second aspect, which may be combined with any other aspect or part thereof described herein, the drainage line connector, when opened by the patient line recirculation cap, (i) is in fluid communication with a used PF fluid line and (ii) is in fluid communication with a disposable drainage line.

[0081] In the forty-third aspect, which may be combined with any other aspect or part thereof described herein, the PD system includes a flow meter output to a control unit, said at least one flow meter being positioned and arranged to measure the flow rate of fresh and used PD fluid.

[0082] In the forty-fourth aspect, which may be combined with any other aspect or part thereof described herein, the PD system is configured such that fresh and used PD fluid travel through the flow meter in the same direction.

[0083] In the forty-fifth aspect, combined with Figures 1 to 6 Any of the features, functions, and alternatives described in any one or more of the images can be combined with Figures 1 to 6 Any combination of features, functions, and alternatives described in any other diagram.

[0084] Therefore, an advantage of this disclosure is that it provides an automated peritoneal dialysis (“APD”) cycler that reuses many components that would otherwise be disposable.

[0085] Another advantage of this disclosure is that it provides an APD circulator with fluid handling components that directly receive peritoneal dialysis fluid without the need for operation using disposable items such as tubing or flexible sheets.

[0086] Another advantage of this disclosure is that it provides an APD circulator that can utilize unused residual PD fluid during thermal cleaning.

[0087] Another advantage of this disclosure is that it provides a volume-accurate automated peritoneal dialysis (APD) circulation system.

[0088] Another advantage of this disclosure is that it provides an APD circulator with fluid pressure control for pumping fluid into and out of the patient.

[0089] Another advantage of this disclosure is that it provides a relatively quiet APD circulator.

[0090] Another advantage of this disclosure is that it provides a relatively simple, disposable kit.

[0091] Another advantage of this disclosure is that it provides a reusable fluid circuit with a small overall volume, such that the PD fluid remaining in the PD fluid container at the end of treatment is sufficient to fill and thermally clean the entire volume of the reusable fluid circuit.

[0092] Another advantage of this disclosure is that it provides an APD system in which a patient line from a first APD treatment is used as a drainage line in a second APD treatment.

[0093] Additional features and advantages are described in the following detailed description and accompanying drawings, and will be apparent from them. The features and advantages described herein are not exhaustive, and in particular, many additional features and advantages will be apparent to those skilled in the art based on the accompanying drawings and description. Furthermore, no particular embodiment is required to possess all the advantages listed herein, and it is explicitly contemplated that individual advantageous embodiments are claimed separately. Moreover, it should be noted that the language used in the specification has been chosen primarily for readability and instructional purposes and is not intended to limit the scope of the subject matter of the invention. Attached Figure Description

[0094] Figure 1 This is a schematic diagram of one embodiment of the automated peritoneal dialysis (“APD”) cycler and associated system using heat-cleaned equipment disclosed herein.

[0095] Figure 2 This is a schematic diagram of a second embodiment of the APD circulator and associated system using thermal cleaning as disclosed herein.

[0096] Figure 3 This is a schematic diagram of a third embodiment of the APD circulator and associated system using thermal cleaning as disclosed herein.

[0097] Figure 4 This is a schematic diagram of a fourth embodiment of the APD circulator and associated system using thermal cleaning as disclosed herein.

[0098] Figure 5 This is a schematic diagram of a fifth embodiment of the APD circulator and associated system using thermal cleaning as disclosed herein.

[0099] Figure 6 This is a schematic diagram of a sixth embodiment of the APD circulator and associated system using thermal cleaning as disclosed herein. Detailed Implementation

[0100] Now refer to the accompanying drawings, and especially to... Figure 1 The automated peritoneal dialysis (“APD”) system 10a and associated methods disclosed herein include an APD machine or circulator 20a. System 10a and circulator 20a (like other systems and circulators described herein) attempt to eliminate as many disposable items as possible and instead provide a large portion of their fluid-carrying components as reusable parts, which are sterilized or disinfected along with the flow path of circulator 20a between treatments. Fluid lines within the machine or circulator are reused. In particular, Figure 1The illustration shows a circulator 20a including 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 the line connectors 26a to 26c are respectively housed in covers 28a to 28c, which can be attached to the housing 22, for example, via hinges. The covers 28a to 28c are hinged open to allow the line connectors 26a to 26c to connect to disposable PD fluid containers 102a to 102c. The covers 28a to 28c are hinged closed to allow the line connectors 26a to 26c to instead connect to reusable circulator connectors 30a to 30c.

[0101] As used herein, “thermal cleaning” can mean “heating over time to at least a sufficient level of sterilization, and possibly to a sterilization level.” The practical difference between a sterilization level and a sterilization level is that if the circulator flow path and components are sterilized or cleaned to a sterilization level, no further filtration is required. If the circulator flow path and components are sterilized or cleaned to a sterilization level, some form of filtration is provided, such as one or more sterile, sterile-grade filters (not shown, and which may themselves be sterile) in patient line 104. The goal of each of the systems 10a to 10f described herein is to thermally clean the circulator flow path and components to a sterilization level such that no additional filters are required. However, if it is found that a sterilization level cannot be met or is consistently not met, additional filtration is required, such as a sterile-grade filter (not shown) in patient line 104. Therefore, “thermal cleaning” as used herein can mean at least sterilized and sterile (if possible).

[0102] PD fluid containers 102a to 102c may be provided as part of a disposable kit 100 (e.g., a sterilized disposable kit 100) along with disposable patient tubing 104, disposable drainage tubing 106, and possibly an additional disposable supply tubing 108. In an alternative embodiment, the disposable kit 100 (e.g., a sterilized disposable kit 100) includes disposable patient tubing 104, disposable drainage tubing 106, and possibly an additional disposable supply tubing 108, but in which case PD fluid containers 102a to 102c are provided separately to connect to reusable PD fluid tubing 24a to 24c at the start of treatment. Disposable patient tubing 104 extends to the patient for treatment, while disposable drainage tubing 106 may extend to a disposable drainage container or a house drain. The disposable kit 100 may also include an optional fourth PD fluid container 102d, which connects to a reusable circulator connector 30c via disposable supply tubing 108 during treatment. Any of the reusable PD fluid lines 24a to 24c, any of the reusable tubing located within the circulator 20a, any part of the housing 22, and any part of the disposable kit 100 may be made of metal (e.g., stainless steel, steel) or plastic (e.g., polyetheretherketone (“PEEK”), polyvinyl chloride (“PVC”), or non-PVC materials such as polyethylene (“PE”), polyurethane (“PU”), or polycarbonate (“PC”).

[0103] In one embodiment, the disposable patient tubing 104 used in the first treatment is used as a disposable drainage tubing 106 in the second treatment. Reusing the disposable patient tubing 104 as a future drainage tubing further reduces single-use waste and is envisioned for use in each of the systems 10a to 10f discussed herein.

[0104] Several embodiments are envisioned to prevent used patient tubing from being reused as new patient tubing. One way to do this is mechanical. For example, in cases where the patient circulator connector 30a differs from the drainage circulator connector 30b, the disposable patient tubing 104 is configured such that, after treatment, the end previously connected to the patient circulator connector 30a is reconnected to the other end of the disposable patient tubing 104, which has been connected to the patient's transfer kit, thereby forming a loop for storage between treatments, and wherein the connection forming the loop is permanent, such that the end previously connected to the patient circulator connector 30a cannot be reconnected to the patient circulator connector. The connector for connecting to the drainage circulator connector 30b is located elsewhere in the loop, covered by a fragile shield, which is removed during the second treatment to expose the disposable drainage connector, which is unscrewed, for example, from the mating connector to undue the loop.

[0105] In another mechanical example, again where the patient circulation connector 30a differs from the drainage circulation connector 30b, the disposable patient tubing 104 is configured such that the disposable patient connector previously connected to the patient circulation connector 30a is connected at its other end to a disposable drainage connector or to a short tubing leading to the disposable drainage connector. Here, the disposable drainage connector must first be exposed before use.

[0106] Another way, or additional way, to help prevent the single-use patient tubing 104 from being reused as a patient tubing in a second treatment is to chemically modify the patient tubing. In one example, a reusable patient circulation device connector 30a and a reusable drainage circulation device connector 30b have the same construction, such that the drainage circulation device connector 30b receives the same end of the single-use patient tubing 104 previously used as a patient tubing. It is envisioned to provide this end of the patient tubing 104 with a patient / drainage tubing connector having an indicator that changes color, for example, upon contact with PD fluid, so that the patient or caregiver attaching the patient tubing 104 and the drainage tubing 106 for a new treatment can easily identify which tubing is attached to the drainage circulation device connector 30b.

[0107] PD fluid containers 102a to 102d can contain dialysis fluids with different levels of dextran or glucose, such as 1.36% glucose dialysis fluid, 2.27% glucose dialysis fluid, and / or different formulations of PD fluid (such as icodextrin) for the final bag. In the illustrated embodiment, PD fluid containers 102b to 102d contain 1.36% glucose or 2.27% glucose dialysis fluid, such as one or more fill volumes of PD fluid, while PD fluid container 102a contains a single final fill volume of icodextrin, which is formulated to remain in the patient for an extended period of time.

[0108] In the illustrated embodiment, all components within the circulator 20a are reusable, thereby reducing disposable materials to those listed above for the disposable kit 100. PD fluid valves 32a to 32e allow selected PD fluid to flow along a reusable inlet line 34a to a reusable heater 36. In the embodiment, each valve of the APD circulator 20a, including the PD fluid valves 32a to 32e, is an electrically actuated valve with a reusable valve body that is closed (e.g., when not energized for fail-safe operation) or open (e.g., when energized) to allow PD fluid flow through the body. Alternatively, a dual-stabilized valve may be used, perhaps only in non-critical, safe locations. In one embodiment, the dialysate inline heater 36 is also electrically actuated and is, for example, a resistance heater with a reusable heater body that receives PD fluid for treatment and thermal cleaning (e.g., thermal sterilization or thermal disinfection).

[0109] In this embodiment, the inline heater 36 is capable of heating the PD fluid from room temperature or colder temperatures (e.g., if the PD fluid is stored in a cold environment) to body temperature, such as 37°C, at a flow rate of at least 300 ml / min. Lower flow rates may also be achieved, for example, for children or infants. A temperature sensor 38 is located near the heater 36, for example, downstream of the heater, to provide feedback for temperature control. If desired, a second temperature sensor (not shown) may be positioned upstream of the heater 36 so that the inlet temperature of the fresh PD fluid can be taken into account in the heating algorithm. The heater 36 and temperature sensor 38 can be used as flow meters as discussed in more detail herein, such as control flow meters or protection / safety flow meters.

[0110] A reusable pump line 34b extends downstream from the inline heater 36. Numerous fluid components are positioned along the reusable pump line 34b, including a first flow meter 40a, a second flow meter 40b, and a PD fluid pump 42 located between the first and second flow meters 40a and 40b. In an embodiment, flow meters 40a and 40b are electromagnetic flow meters or Coriolis flow meters. Flow meters 40a and 40b are reusable and can be used not only to regulate flow rates but also to integrate the volumes of fresh and used PD fluid during treatment, allowing for the determination of how much fresh PD fluid has been delivered to the patient and how much used PD fluid has been removed from the patient at the end of treatment. The difference between the two is equal to the total amount of fluid removed from the patient during treatment, at least some of which can be removed by ultrafiltration (“UF”), an important parameter for implementation and monitoring.

[0111] exist Figure 1 In one implementation of patient filling (fresh PD fluid flows from right to left), flow meter 40b is used as the primary control flow meter because flow meter 40b is more accurate since air bubbles have been removed in the air trap 44 upstream of flow meter 40b (flow meter 40a is used as a protection or safety flow meter). During patient drainage with reversed flow direction (used PD fluid flows from left to right), flow meter 40a is used as the primary control flow meter because flow meter 40a is now more accurate since air bubbles have been removed in the air trap 44 upstream of flow meter 40a (flow meter 40b is used as a protection or safety flow meter).

[0112] The provision of flow meters 40a and 40b enables the use of a lower-precision PD fluid pump 42, such as a gear pump, centrifugal pump, or other type of pump. The PD fluid pump 42 includes a reusable pump body that receives PD fluid for pumping. That is, the PD pump 42 does not require the PD fluid to flow within a disposable object such as tubing or a cartridge. The reusable pump body of the pump 42 itself receives PD fluid. By controlling the level of the current, voltage, or voltage pulse sequence flowing to the PD fluid pump, the dialysis fluid pump 42 is controllable to pump into and out of the patient at or below pressure limits. Positive patient pressure limits can be, for example, 1 to 5 psig (e.g., 2 psig (14 kPa)). Negative patient pressure limits can 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 if needed, for example, for children or infants. In one embodiment, the dialysis fluid pump 42 is bidirectional and continuous, allowing a single pump to be provided.

[0113] Two bidirectional flow meters 40a and 40b can be provided, allowing their outputs to be compared to ensure accuracy. Alternatively, some flow meters are unidirectional, with one of the flow meters 40b used for patient filling and the other for patient drainage. Furthermore, if a flow meter performs better under positive or negative pressure, flow meters 40a and 40b can be arranged accordingly on the appropriate side of the PD fluid pump 42. If two unidirectional flow meters 40a and 40b are provided, two additional unidirectional flow meters can be provided, or possibly a single bidirectional flow meter can be provided, where the unidirectional flow meters 40a and 40b are used for control, and one or more additional flow meters are used for redundancy / protection in case of hazardous situations due to component failure.

[0114] In the illustrated embodiment, the air trap 44 is located between the PD fluid pump 42 and the flow meters 40a and 40b; however, the air trap 44 may be located in an alternative location along the reusable pumping line 34b. In a 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. The additional volume may be useful, for example, during thermal cleaning (e.g., thermal sterilization or heat disinfection). Even if not illustrated, the air trap 44 may be provided with any of the circulators 20a to 20f of the corresponding systems described herein.

[0115] Pressure sensor 46 is positioned between flow meter 40b and the patient along reusable patient tubing 34c. Pressure sensor 46 records the pressure of fresh PD fluid delivered to the patient and used PD fluid removed from the patient. The pressure readings are used to control PD fluid pump 42 so that the pressure of the fresh and used PD fluid flows is maintained within the patient pressure limits listed above.

[0116] A reusable patient tubing 34c extends from the flow meter 40b to the reusable patient circulator connector 30a. A reusable drainage tubing 34d extends from the patient tubing 34b to the reusable drainage circulator connector 30b. A reusable venting tubing 34e extends from the top of the air trap 44 to the drainage tubing 34d to allow air to be delivered to the drainage tubing. A patient valve 32f is positioned along the reusable patient tubing 34c. A drainage valve 32g is positioned along the reusable drainage tubing 34d. A venting valve 32h is positioned along the reusable venting tubing 34e. Valves 32f to 32h can also be electrically actuated valves with a reusable valve body that is closed (e.g., when not energized for fail-safe operation) or open (e.g., when energized) to allow fresh or used PD fluid or air to flow through the body.

[0117] Figure 1 The illustrated system 10a of this disclosure includes an APD circulation device 20a comprising a control unit 50 having one or more processors 52 and one or more memories 54, which receive, store, and process signals or outputs from flow meters 40a and 40b, a pressure sensor 46, a temperature sensor 38, an optional conductivity sensor (shown below), and possibly a cap position sensor, to detect whether connectors 26a to 26c of caps 28a to 28c are attached (so that treatment can be initiated or an alarm can be triggered accordingly). The control unit 50 uses pressure feedback to control the dialysis fluid 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 dialysis fluid heater 36 to heat fresh dialysis fluid to, for example, body temperature, and to heat clean fluid at the end of treatment to clean (disinfect or sterilize) the reusable fluid pathway of the circulation device 20a. For the purposes of this discussion, the control unit 50 uses temperature-compensated conductivity readings to analyze fresh and / or used dialysis fluid.

[0118] The control unit 50 also includes a video controller 56 associated with a user interface 58, which may include a display screen operated by a touchscreen and / or one or more electromechanical buttons (such as membrane switches). The user interface 58 may also include one or more speakers for outputting alarms, warnings, and / or voice-guided commands. The user interface 58 may be configured as follows: Figure 1 The circulator 20a illustrated herein may be a remote user interface operating in conjunction with the control unit 50. The control unit 50 may also include a transceiver (not shown) and a wired or wireless connection to a network (e.g., the Internet) for sending treatment data to and receiving prescription instructions from a doctor's or clinician's server in connection with the doctor's or clinician's computer.

[0119] The control unit 50 also opens and closes the dialysis fluid valves 32a to 32h in different combinations in conjunction with the operation of the dialysis fluid pump 42 and the heater 36 to run a pre-infusion sequence, multiple patient filling sequences, multiple patient drainage sequences, and a thermal cleaning (e.g., thermal sterilization) sequence at the end of PD treatment.

[0120] like Figure 1The circulator 20a illustrated in the diagram is in a treatment configuration, with caps 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 circulator connector 30a to be connected to a disposable patient line 104, and (v) a reusable drainage circulator connector 30b to be connected to a disposable drainage line 106. Containers 102a to 102c may be disposable and include ports for connection to the reusable lines 24a to 24c, or smaller disposable lines. In the illustrated embodiment, an optional disposable PD fluid container 102d is connected to the reusable supply connector 30c via a disposable supply line 108. If the optional disposable PD fluid container 102d and disposable supply line 108 are not provided, the reusable supply connector 30c can be configured to close by its own spring or by means of a separate (possibly tethered) cap.

[0121] At the end of treatment and, possibly after each of the PD fluid containers 102a to 102d has been emptied, the disposable items are removed: (i) the disposable PD fluid container 102a is removed from the reusable line connector 26a, (ii) the disposable PD fluid container 102b is removed from the reusable line connector 26b, (iii) the disposable PD fluid container 102c is removed from the reusable line connector 26c, (iv) the patient line 104 is removed from the reusable patient circulator connector 30a, (v) the disposable drainage line 106 is removed from the reusable drainage circulator connector 30b, and (v) the disposable supply line 108 (if provided) is removed from the reusable circulator connector 30c. For heat cleaning (e.g., heat sterilization or heat disinfection), the user (i) closes the cover 28a, so that the reusable tubing connector 26a is connected to the reusable patient circulation device connector 30a, (ii) closes the cover 28b, so that the reusable tubing connector 26b is connected to the reusable drainage circulation device connector 30b, and (iii) closes the cover 28c, so that the reusable tubing connector 26c is connected to the reusable circulation device connector 30c.

[0122] The provision of covers 28a to 28c makes it unlikely that the reusable line connectors 26a to 26c will be incorrectly connected to the reusable circulator connectors 30a to 30c. However, here and in all other system and circulator embodiments described herein, it is contemplated that the line connectors 26a to 26c and the circulator connectors 30a to 30c be color-coded and / or keyed to match the paired connectors.

[0123] With caps 28a to 28c closed and connectors 26a / 30a, 26b / 30b, and 26c / 30c connected, the fluid loop of the circulator 20a is also closed for thermal cleaning (e.g., thermal sterilization or thermal disinfection). In an embodiment, control unit 50 causes all valves 32a to 32h to open, activating PD fluid pump 42 and energizing the heater to circulate (e.g., multiple times) the heated cleaning fluid through a closed cleaning loop, which includes reusable PD fluid lines 24a to 24c, a reusable inlet line 34a, a reusable pumping line 34b, a reusable patient line 34c, a reusable drainage line 34d, and a reusable exhaust line 34e. In one embodiment, the cleaning fluid is a PD fluid, such as fresh PD fluid, heated to a sterilization or disinfection temperature, for example, between 70°C and 130°C, e.g., 70°C for sterilization and 120°C and above for disinfection. If desired, the various valves 32a to 32h can be switched on and off, and the PD fluid pump 42 can be reversed once or multiple times. The thermal cleaning (e.g., thermal sterilization or thermal disinfection) sequence of system 10a continues until a sufficient thermal cleaning dose (e.g., A0 dose) is provided to properly clean (sterilize or disinfect) each of the lines and components in contact with the reusable fluid paths listed above and discussed herein.

[0124] In an alternative embodiment, the reusable circulator connectors 30a to 30c become line connectors and are moved to the ends of the patient line 104, drainage line 106, and supply line 108, respectively. If the optional supply container 102d is not used, the reusable line connectors can again be configured to close via a self-spring or be capped via a separate (e.g., tethered) cap. At the end of treatment, 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 thermal cleaning loop. The control unit 50 operates the thermal cleaning (e.g., thermal sterilization or thermal disinfection) sequence as described above. In this alternative embodiment, caps 28a to 28c may or may not be provided.

[0125] Now for reference Figure 2Alternative APD systems 10b and associated methods disclosed herein include APD machines or circulators 20b. System 10b includes many of the same components as system 10a, which are numbered the same and may be described in conjunction with or without system 10b, but in any case includes all structures, functions, and alternatives discussed in conjunction with system 10a. In particular, circulator 20b includes a housing 22 that houses PD fluid valves 32a to 32c and a drainage valve 32g, a reusable inlet line 34a, an inline heater 36, at least one temperature sensor 38, an air trap 44, a reusable pump line 34b, at least one pressure sensor 46, a reusable patient line 34c, a reusable drainage line 34d, a reusable exhaust line 34e, a drainage valve 32g, a control unit 50, and a user interface 58. The circulator 20b also includes reusable PD fluid lines 24a to 24c, which extend to reusable line connectors 26a to 26c, respectively. A reusable patient circulator connector 30a and a reusable drainage circulator connector 30b are also provided.

[0126] 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 precise gear pump or other pump) with a highly inherently precise piston or diaphragm pump 142 under the control of control unit 50. This piston or diaphragm pump 142 precisely pumps all delivered fresh PD fluid and all removed used PD fluid, allowing control unit 50 to accurately calculate the patient fluid (e.g., UF) removed during treatment. Piston pump 142 may require a flushing flow of fluid (such as reverse osmosis (“RO”) water) for lubrication during treatment, which is supplied from an RO water source, for example, via a water pump (not shown), under the control of control unit 50. Like all pumps herein, piston pump 142 includes a body that accepts fresh or used dialysis fluid and operates without utilizing disposable parts.

[0127] To verify the inherent accuracy of the piston pump 142, the control unit 50 can pump the first few milliliters of fresh PD fluid through the heater 36 at the start of each patient filling without heating the fluid. A first temperature measurement T1 is performed at the temperature sensor 38. The heater 36 is then energized, and the pneumatic force required to raise the temperature to T2 (e.g., a filling temperature of 37°C) as measured at the temperature sensor 38 provides a measurement of the PD fluid flow rate. The accuracy of the piston pump 142 can be checked using the dialysis fluid inline heater 36. Here, at the start of each patient filling, the control unit 50 causes the first few milliliters of fresh PD fluid to be pumped through the heater 36 without heating the fluid. The control unit 50 causes a first temperature measurement T1 to be performed. The control unit 50 then causes the heater 36 to be energized, and the pneumatic force required to raise the temperature to T2 (e.g., a filling temperature of 37°C) is measured, providing a measurement of the PD fluid flow rate. Control unit 50 knows the specific heat capacity of water and the temperature increment (T2-T1). The control unit uses this temperature increment (T2-T1) to convert the thermal effect (energy / time) into a flow rate (mass / time). If the difference between the value of fluid pumped by pump 142 calculated by control unit 50 and the value determined via heater 36 exceeds a limit, control unit 50 causes user interface 58 to notify the user that pump 142 needs to be recalibrated and / or sends a communication indicating this situation to the service portal via the network. Redundancy volume calculation and the associated checks using heater 36 can be performed using any of the systems 10a to 10f discussed herein.

[0128] Another difference from system 10b includes the provision of one or more level sensors 48 (which may also be provided with system 10a) having an air trap 44 and an output to control unit 50. The one or more level sensors 48 allow fresh PD fluid at a specific level or level range to be maintained in the air trap 44. The one or more level sensors 48 can be provided with any air trap discussed herein. System 10b includes a conductivity sensor 60 positioned along a reusable drainage line 34d, which outputs to control unit 50 and can be temperature compensated. The conductivity sensor 60 can be used, for example, to detect the conductivity of the fresh PD fluid during pre-filling to ensure it has the type opened, such as having the opened glucose or dextrose level. Alternatively or additionally, a conductivity sensor 74 can be used, for example, to detect the conductivity of the fresh PD fluid during pre-filling to ensure it has been properly mixed (e.g., if the online PD fluid source is instead connected to one of the reusable PD fluid lines 24a to 24c). Alternatively or additionally, the conductivity sensor 74 can be used to detect the conductivity of the used PD fluid to assess treatment effectiveness and / or identify patient conditions such as peritonitis. A temperature sensor 58b is located near the conductivity sensor 74, allowing the conductivity readings from the sensor to be temperature-compensated.

[0129] Another difference from system 10b is the provision of three-way valves 132a and 132b, each under the control of control unit 50. Three-way valves 132a and 132b switch back and forth between allowing fresh or used PD fluid to flow in one direction or a second direction. Three-way valve 132a switches between (i) allowing fresh or used dialysis fluid to flow between piston pump 142 and patient circulation connector 30a (connected to disposable patient tubing 104), or (ii) allowing PD fluid for pre-injection or thermal cleaning (such as heated fresh PD fluid) to flow from valve 132a through reusable pre-injection / thermal cleaning tubing 34f, drainage valve 32g, conductivity sensor 60, reusable drainage tubing 34d (connected to disposable drainage tubing 106 for pre-injection) to a house drain or container drain for pre-injection or for thermal cleaning in the same direction and / or in the other direction. The three-way valve 132b switches between the following operations: (i) allowing fresh or used dialysis fluid to flow between the reusable pump line 34b and the patient circulation device connector 30a (connected to the disposable patient line 104), or (ii) allowing air, PD fluid, or mixtures thereof for pre-injection, treatment, or thermal cleaning from the air trap 44 through the reusable exhaust line 34e, a portion of the pump line 34b, and the three-way valve 132b as discussed above through the reusable drainage line 34d to the drainage circulation device connector 30b (connected to the disposable drainage line 106).

[0130] Another difference from system 10b is that after the PD fluid containers 102a to 102c are disconnected for thermal cleaning following treatment, the line connectors 26a to 26c are instead inserted into the thermal cleaning connectors or ports 62a to 62c to form a closed thermal cleaning loop. In the illustrated embodiment, each of ports 62a to 62c is protected, for example, by a cover 64 hinged to the circulator 20b, which is removed to allow the line connectors 26a to 26c to connect to or be inserted into the thermal cleaning connectors or ports 62a to 62c. The thermal cleaning connectors or ports 62a to 62c may be self-closing, such as spring-loaded, or suitably sealed closed via the cover 64. As illustrated, the thermal cleaning connectors or ports 62a to 62c are fluidly connected to the second thermal cleaning line 34g.

[0131] For thermal cleaning to form a closed thermal cleaning loop, the patient circulation device connector 30a and the drainage circulation device connector 30b are each provided with a recirculation cap 66, which seals off the connectors 30a and 30b during thermal cleaning to redirect the thermal cleaning fluid flowing through the reusable lines 34c and 34d back to the second thermal cleaning line 34g (or redirect the thermal cleaning fluid flowing through the second thermal cleaning line 34g back to the reusable lines 34c and 34d). The recirculation cap 66 includes or defines an internal fluid lumen or passage 68, which is in fluid communication with the second thermal cleaning line 34g and the reusable line 34c or reusable line 34d when closed against the connectors 30a and 30b. Flow during the sterilization / disinfection of system 10b will have many alternatives, as all lines will be sterilized / disinfected. A primary thermal cleaning path will begin at pump 42, drain through reusable pre-injection / thermal cleaning line 34f and reusable drainage line 34d to drainage connector 30b, then through reusable line 34g to patient connector 30a, drain through thermal cleaning connector or ports 62a to 62c, and return to pump 42 via heater 36 and air trap 44.

[0132] With the thermal cleaning loop closed as described above, control unit 50 performs the thermal cleaning (e.g., thermal sterilization or thermal disinfection) sequence as described above, for example, by pumping heated fresh PD fluid in multiple directions and switching valves as needed. In an embodiment, three-way valves 132a and 132b are switched back and forth to force the thermal cleaning fluid to flow in each of the alternative pathways. The thermal cleaning sequence of system 10b continues until a sufficient thermal cleaning dose (e.g., A0 dose) is provided to properly sterilize each line forming the closed thermal cleaning loop provided by circulator 10b.

[0133] Now for reference Figure 3Another alternative APD system 10c and associated method disclosed herein includes an APD machine or circulator 20c. System 10c includes many of the same components as systems 10a and 10b, which are numbered the same and may be described in conjunction with or without system 10c, but in any case includes all the structures, functions and alternatives discussed in conjunction with systems 10a and 10b. Specifically, the circulator 20c includes a housing 22 that houses 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 pump line 34b, pressure sensors 46a and 46b, a reusable patient line 34c, a reusable drainage line 34d, a reusable exhaust line 34e, a reusable thermal cleaning line 34g, a drainage valve 32g, an exhaust valve 32h, a control unit 50, a conductivity sensor 60 along the reusable drainage line 34d, and a user interface 58.

[0134] The circulator 20c also includes reusable PD fluid lines 24a to 24c, which extend to reusable line connectors 26a to 26c, respectively. A reusable patient circulator connector 30a and a reusable drainage circulator connector 30b are also provided. The circulator 20c of system 10c forms a closed thermal cleaning loop in the same manner as the circulator 10b of system 10b, using thermal cleaning connectors or ports 62a to 62c and a movable cap 64 for connecting the reusable PD fluid lines 24a to 24c via the reusable line connectors 26a to 26c, as discussed above for system 10b. The circulator 20c also provides a recirculation cap 66 with an internal fluid lumen or passage for connecting to and closing the reusable patient circulator connector 30a and the reusable drainage circulator connector 30b for thermal cleaning, as described for system 10b.

[0135] The circulator 20c of system 10c also includes a highly inherently precise piston pump or diaphragm pump 142 under the control of control unit 50, as described above for the circulator 10b of system 10b. Like all pumps herein, the piston pump 142 includes a body that receives fresh or used dialysis fluid and is not operated using disposable parts. The piston pump 142 may require a flushing flow of fluid such as reverse osmosis (“RO”) water during treatment for lubrication (but may not be necessary since the piston pump 142 is pumping RO water or the like). The circulator 20c, as described, provides such a source of RO water. In particular, the circulator 20c separates internal reusable tubing or tubing (i.e., PD fluid tubing) from the operating fluid tubing, which is filled with different operating fluids, such as reverse osmosis (“RO”) water. Although not shown, in one embodiment, the operating fluid loop 70 including the piston pump 142 (discussed below) is arranged to extend through the flush flow port of the piston pump 142 and enter the inlet of the piston pump 142 from the outlet flush flow port. Such an arrangement may reduce the amount of piping required for the flush flow and provide more than sufficient flush flow rate.

[0136] The PD fluid line and the operating fluid line are separated by a flexible membrane disposed within a pair of balancing chambers 72a and 72b. The operating fluid (e.g., RO water) drives one side of each of the balancing chambers 72a and 72b in an operating fluid loop 70, which includes a piston pump 142 and a storage chamber 144 for containing the operating fluid (e.g., RO water). This ensures sufficient operating fluid for each stroke of the balancing chambers 72a and 72b. The operating fluid loop 70 also includes operating fluid valves 32i and 32j, controlled by a control unit 50, which are sequentially connected to tap the balancing chambers 72a and 72b. The control unit 50 causes valves 32i and 32j to close during treatment to lock the operating fluid in place, making the operating side fluid-rigid. If it is desired to allow some heat to reach the operating side, valves 32i and 32j can be opened during a thermal cleaning phase for circulation. Valves 32i and 32j can also be opened to allow new operating fluid to enter piston pump 142 to compensate for any inherent leakage flow between the piston and cylinder of piston pump 142.

[0137] In each stroke of balancing chambers 72a and 72b, RO pump 142 (i) draws RO water from one balancing chamber 72a or 72b, resulting in an equal volume of fresh or used dialysis fluid entering the balancing chamber on the other side of the flexible membrane, and (ii) delivers RO water to the other balancing chamber 72a or 72b, resulting in an equal volume of fresh or used dialysis fluid leaving the balancing chamber on the other side of the flexible membrane. Balancing chambers 72a and 72b provide an additional layer of accuracy should the piston pump 142 become inaccurate for any reason. That is, the volume of balancing chambers 72a or 72b is known, so each time they are struck, the control unit can infer the volume of fresh dialysis fluid delivered to the balancing chamber or the volume of used dialysis fluid removed from the patient. Therefore, stroke counting of balancing chambers 72a or 72b allows control unit 50 to accumulate the total delivered fresh and used PD fluid. This amount can be compared with the total amount of fresh and used PD fluid calculated by the control unit 50 counting the known volumetric pumping strokes of the RO piston pump 142.

[0138] In the illustrated embodiment, during treatment, control unit 50 closes operating fluid valves 32i and 32j, causing piston pump 142 to pump in opposite directions to (i) draw RO water from balance chamber 72a and push it to balance chamber 72b or (ii) draw RO water from balance chamber 72b and push it to balance chamber 72a. During non-treatment periods, control unit 50 may open one or both operating fluid valves 32i and 32j (or switch the valves to open and closed) for various reasons discussed above and additionally for a fresh flushing flow of RO at piston pump 142.

[0139] On the treatment fluid side, the circulator 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 balance chamber 72a to the patient via the reusable patient line 34c, or allows used PD fluid to flow from the patient to the balance chamber 72a via the reusable patient line 34c during the inhalation stroke. Similarly, patient valve 32f2 allows fresh PD fluid to flow from the output stroke of the balance chamber 72b to the patient via the reusable patient line 34c, or allows used PD fluid to flow from the patient to the balance chamber 72b via the reusable patient line 34c during the inhalation stroke.

[0140] On the treatment fluid side, the circulator 20c also includes multiple supply and / or drainage outlet valves 32k to 32n, each under the control of the control unit 50. The supply and drainage outlet valves 32k either allow fresh PD fluid to flow to the balance chamber 72a via the reusable pump line 34b during the inhalation stroke, or allow used PD fluid to flow from the balance chamber 72a to the drainage tube via the drainage line 34d during the output stroke. The supply valve 32l allows fresh PD fluid to flow to the balance chamber 72a or balance chamber 72b via the reusable pump line 34b during the inhalation stroke. The supply valve 32m allows fresh PD fluid to flow to the balance chamber 72b via the reusable pump line 34b during the inhalation stroke, and allows used PD fluid to flow from the balance chamber 72a to the drainage tube via the reusable drainage circulator connector 30b during the output stroke. The supply and drain outlet valves 32n either allow fresh PD fluid to flow to the balance chamber 72b via the reusable pump line 34b during the suction stroke, or allow used PD fluid to flow from the balance chamber 72b to the drain line via the drain line 34d during the output stroke. The control unit 50 also sequences the supply and / or drain outlet valves 32k to 32n during hot cleaning to guide fresh, heated PD fluid in a desired manner during the sequence.

[0141] The circulator 20c offers several advantages, including enabling pressure sensors 46a and 46b to be positioned along the operating fluid loop 70. This means that if a fluid leak involving the pressure sensors occurs, the leak involves RO water, not dialysis fluid. However, pressure sensors 46a and 46b provide accurate positive and negative PD fluid pressure readings, with the PD fluid pressure precisely transmitted across the flexible membranes of the balancing chambers 72a and 72b. Additionally, the piston pump 142 pumps RO water instead of fresh or used PD fluid, which reduces wear and increases component life (e.g., wear and component life of pressure sensors 46a and 46b), at least in part because the piston pump 142 does not need to be subjected to heated or chemically treated thermal cleaning fluids. Placing components within the operating fluid loop 70 makes the circulator 20c well-suited for the higher temperatures and cleaning times associated with sterilization and thermal cleaning discussed above. Furthermore, as mentioned above, the operating fluid loop 70 and storage chamber 144 provide a readily available supply of flushing fluid for the piston pump 142.

[0142] Following treatment, with the thermal cleaning loop closed as described in conjunction with the circulator 20b (PD fluid lines 24a to 24c connected to the circulator and recirculation cap 66 closed), the control unit 50 performs a thermal cleaning (e.g., thermal sterilization or thermal disinfection) sequence on the circulator 20c using, for example, heated fresh PD fluid, pumped in multiple directions, and switching valves as needed. If necessary, the circulator 20c may be supplied with an additional thermal cleaning pump 242, under the control of the control unit 50, along the reusable thermal cleaning line 34g. This pump may be a less precise gear pump, centrifugal pump, or other type of pump. The thermal cleaning (e.g., cleaning activity) sequence of the system 10c continues until a sufficient thermal cleaning dose is provided to properly sterilize each of the treatment fluid lines forming the closed thermal cleaning loop provided by the circulator 10c. Again, sterilization is not required for the operating fluid loop 70.

[0143] Now for reference Figure 4 Another alternative APD system 10d and associated method disclosed herein includes an APD machine or circulator 20d. System 10d includes many of the same components as systems 10a to 10c, which are numbered the same and may be described in conjunction with or without system 10d, but in any case includes all the structures, functions and alternatives discussed in conjunction with systems 10a to 10c. In particular, circulator 20d includes a housing 22 that houses PD fluid valves 32a to 32c, a reusable inlet line 34a, an inline heater 36, at least one temperature sensor 38, a reusable pump 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.

[0144] The circulator 20d also includes reusable PD fluid lines 24a to 24c, which extend to reusable line connectors 26a to 26c, respectively. A reusable patient circulator connector 30a and a reusable drainage circulator connector 30b are also provided. The circulator 20d of system 10d forms a closed thermally cleaned loop in the same manner as the circulators 20b and 20c of systems 10b and 10c, using thermally cleaned connectors or ports 62a to 62c and a movable (e.g., hinged) cover 64 for connecting the reusable PD fluid lines 24a to 24c via the reusable line connectors 26a to 26c, as discussed above for systems 10b and 10c. The circulator 20d also provides a recirculation cap 66 with an internal fluid lumen or passage for connection to and fluid shut-off reusable patient circulator connector 30a and reusable drainage circulator connector 30b for thermal cleaning, as described for systems 10b and 10c.

[0145] The circulator 20d of system 10d is similar to the circulator 20a of system 10a because it can use less precise gear pumps, centrifugal pumps, or other types of pumps, each under the control of control unit 50; here, two gear pumps or other pumps 42a and 42b are used. Circulator 20d also provides volumetric chambers 82a and 82b similar to the balancing chambers 72a and 72b of circulator 20c, which have flexible membranes. However, in Figure 4 In this embodiment, fresh or used PD fluid is delivered and removed from one side of the volume chamber membrane, while air moves back and forth on the other side of the membrane, which is the opposite of the dual-fluid configuration of the third main embodiment. In one embodiment, during the filling phase, gear pump 42a is used to draw fresh PD fluid from at least one of the PD fluid containers 102a to 102c and deliver the fluid to one of the volume chambers 82a and 82b, while gear pump 42b delivers fresh fluid from the other of the volume chambers 82a and 82b to the patient. During the drainage phase, gear pump 42b is instead used to draw used PD fluid from the patient and deliver the fluid to one of the volume chambers 82a and 82b, while gear pump 42a delivers used PD fluid from the other of the volume chambers 82a and 82b to a drainage tube via drainage port 30b.

[0146] The other side of the membrane in volume chambers 82a and 82b is sequentially filled with air and then purged from the chamber. The air side of volume chambers 82a and 82b is pneumatically connected to air circuit 80. In the illustrated embodiment, air circuit 80 includes two air valves 32o and 32p, each under the control of control unit 50.

[0147] In one embodiment, air valves 32o and 32p are closed during treatment, thereby locking multiple volumes of air in chambers 82a and 82b (different locked volumes are possible because the volume depends on the position of the membrane when valve 32o or 32p is closed). When one of chambers 82a or 82b is filled with fresh or used PD fluid, the corresponding pressure sensor 146a or 146b measures a pressure rise. The control unit 50 of system 10d knows the pressure profile and stops the filling of PD fluid at a predetermined pressure value. At the end of the chamber filling stroke, the flow rate can be lower to more easily detect the switching point and minimize the risk of high pressure in chambers 82a or 82b during operation. Both air valves 32o and 32p can be opened during thermal cleaning, for example, to allow both the PD fluid sides of chambers 82a and 82b to be filled with, for example, heated fresh PD thermal cleaning fluid. If desired, the exhaust valve 32p can be opened while the air valve 32o is closed, so as to move the membrane in the volume chamber 82a without moving the membrane in the volume chamber 82b accordingly.

[0148] In the illustrated embodiment, the circulator 20d includes multiple three-way valves under the control of the control unit 50, which are used to control the flow of PD fluid and hot cleaning fluid. A first three-way valve 132c is located upstream of the gear pump or other type of pump 42a and is dedicated to directing fresh (from heater 36) PD fluid into or out of volume chambers 82a or 82b (depending on the stage). A second three-way valve 132d is located downstream of the gear pump 42a and is also dedicated to directing fresh PD fluid into or out of volume chambers 82a and 82b. A third three-way valve 132e is located upstream of the gear pump 42b and is used to direct fresh PD fluid out of or into volume chambers 82a and 82b. A fourth three-way valve 132f is located downstream of the gear pump 42b and is also dedicated to directing fresh PD fluid to the patient and draining used PD fluid from the patient, and directing air and / or fresh PD fluid to the drainage tube during pre-injection or air removal phases. A fifth three-way valve 132g is configured to circulate back and forth between the first volume chamber 82a and the second volume chamber 82b, for example, during thermal cleaning.

[0149] In the illustrated embodiment, pressure sensor 46 is located between downstream pump 42b and reusable patient circulation device connector 30a to output to control unit 50 for controlling patient pressure, as described herein. Additionally, air pressure sensors 146a and 146b are provided to sense air pressure on the “dry” side of each membrane of the first and second volume chambers 82a and 82b, respectively, reflecting the fresh and used PD fluid pressure on the other side of the membrane. Control unit 50 can compare readings from pressure sensors 146a and 146b with pressure sensor 46, for example, at the start of treatment, to confirm that the pressure sensors are measuring the same pressure. If not, control unit 50 can determine that one of pressure sensors 146a, 146b, or 46 has drifted, resulting in a maintenance notification being issued on the user interface 58 of the APD circulation device 20d.

[0150] Following treatment, with the thermal cleaning loop closed as described in conjunction with the circulator 20b (PD fluid lines 24a to 24c connected to the circulator and recirculation cap 66 closed), the control unit 50 performs a thermal cleaning (e.g., thermal sterilization or thermal disinfection) sequence on the circulator 20d by using, for example, heated fresh PD fluid, pumping in multiple directions, and switching valves as needed. The circulator 20d may switch each three-way valve 132c to 132g multiple times during thermal cleaning to ensure that the thermal cleaning fluid contacts each passage of the closed thermal cleaning loop of the circulator. The thermal cleaning (e.g., thermal sterilization or thermal disinfection) sequence of the system 10d continues until a sufficient thermal cleaning dose (e.g., A0 dose) is provided to properly sterilize each of the treatment fluid lines forming the closed thermal cleaning loop provided by the circulator 10d.

[0151] Now for reference Figure 5Another alternative APD system 10e and associated method disclosed herein includes an APD machine or circulator 20e comprising a housing 22. System 10e includes all the structures, functions, and alternatives described above for circulator 20d for system 10d, including all valve and pump sequences for the treatment and thermal cleaning procedures (including connections for closing the thermal cleaning loop) described for circulator 20d. Circulator 20e adds a flow sensor 90 output to control unit 50 for tracking the volume of fresh and used PD fluid delivered to and removed from the patient. The goal of circulator 20d in system 10e is based on the accuracy of the volume chambers 82a and 82b on a per-stroke basis, and control unit 50 counts the number of strokes to determine the total volume of fresh and used PD fluid delivered. However, if the per-stroke accuracy of the volume chambers 82a and 82b is found to be insufficient, an additional flow sensor 90 can be used, the output of which is integrated over time by the control unit 50 to determine the total volume of fresh and used PD delivered and the resulting amount of patient fluid removed (e.g., UF).

[0152] exist Figure 5 In this configuration, the flow sensor 90 is placed in an alternative location. If the flow sensor is a unidirectional flow sensor, it can be placed upstream of the three-way valve 132c, so that the flow sensor 90 only sees fresh PD fluid (without the accumulation of proteins, etc., from the patient on its surface), which helps maintain accuracy. Here, it is envisioned that the control unit 50 monitors the flow of fresh PD fluid in relation to the movement of the membranes in the volume chambers 82a and 82b. A specific membrane movement during the patient filling phase is correlated with a specific fresh PD fluid flow rate measured by the flow sensor 90. It can then be assumed that the same membrane movement during the patient drainage phase, without the flow sensor 90, produces the same used PD flow rate (or the extrapolated flow rate can be correlated with different membrane movements). In any case, the drainage flow rate can be determined based on measurements performed during the filling phase. If the flow sensor 90 is a bidirectional flow sensor, it can be placed downstream of the three-way valve 132c (dashed line), so that the flow sensor can measure both fresh and used PD flow rates in multiple directions.

[0153] Now for reference Figure 6Another alternative APD system 10f and associated method disclosed herein includes an APD machine or circulator 20f, which includes a housing 22. System 10f includes all the structures, functions, and alternatives described above for circulator 20d, including all the valve and pump sequences for the treatment and thermal cleaning procedures (including connections for closed thermal cleaning loops) described for circulator 20d. System 10f also includes a flow meter 90 output to control unit 50, which is again provided for tracking the volume of fresh and used PD fluid delivered to and removed from the patient. Circulator 20f adds additional three-way valves 132h and 132i and associated fluid lines, allowing PD fluid to flow in the same direction through flow sensor 90, regardless of whether the PD fluid is fresh or used. System 10f's circulator 20f expands the number of different flow sensors 90 that can be used, since not all flow sensors are bidirectional.

[0154] A seventh embodiment (not shown) can use any of the overall flow paths of the circulators 20d to 20f of systems 10d to 10f, but in which the driving force is air, supplied from positive and negative pressure tanks pressurized via pneumatic pumps under the control of control unit 50. The tanks can be supplied with positive and negative pneumatic pressure regulators, respectively, which provide regulated positive and negative pneumatic pressures to, for example, electronically controlled pneumatic solenoid valves that drive the diaphragm fluid pump and valves. The advantage is that the diaphragm fluid pump is reusable and can be calibrated to high precision in production. Additionally, the pump chamber of the diaphragm pump can be relatively large, resulting in less frequent actuation of the diaphragm fluid valves that operate with the diaphragm fluid pump, which in turn improves reliability.

[0155] It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Therefore, it is intended that such changes and modifications be covered by the appended claims. For example, while thermal cleaning (e.g., thermal sterilization or heat disinfection) is disclosed, chemical cleaning, such as citric acid, may be provided instead of or in addition to thermal cleaning. Using used dialysis fluid as a cleaning fluid may have chemical benefits. Other types of disinfection, such as ultraviolet light, may also be used. Additionally, although... Figure 3 System 10c is described as using RO water as its process fluid; however, alternatively, air or a different process fluid can be used. Furthermore, although... Figures 4 to 6 Systems 10d to 10f are described as using air as their compressible fluid, but alternatively, other gases or compressible fluids may be used.

Claims

1. A peritoneal dialysis system, comprising: case; A dialysis fluid pump, the dialysis fluid pump being housed in the housing and including a reusable pump body that receives peritoneal dialysis fluid for pumping; An intra-dialysis fluid heater, the intra-dialysis fluid heater being housed in the housing and including a reusable heater body that receives peritoneal dialysis fluid for heating; A patient tubing connector, provided by the housing and configured to connect to a disposable patient tubing, the patient tubing connector and the disposable patient tubing being configured to supply peritoneal dialysis fluid from the dialysis fluid pump to the patient for peritoneal dialysis treatment; A drainage line connector, provided by the housing and configured to connect to a disposable drainage line for the peritoneal dialysis treatment, wherein the drainage line connector, together with the disposable drainage line, is configured to provide used peritoneal dialysis fluid from the patient to a drain line for the peritoneal dialysis treatment; A first reusable peritoneal dialysis fluid line extends from the housing and includes a first connector configured to mate with the patient line connector for a heated cleaning sequence, and the first connector is configured to mate with a first peritoneal dialysis fluid container for the peritoneal dialysis treatment. A second reusable peritoneal dialysis fluid line extends from the housing and includes a second connector configured to mate with the drainage line connector for the heated cleaning sequence, and the second connector is configured to mate with a second peritoneal dialysis fluid container for the peritoneal dialysis treatment. as well as A control unit configured to run the thermal cleansing sequence after the peritoneal dialysis treatment, wherein the first connector of the first reusable peritoneal dialysis fluid line is disconnected from the first peritoneal dialysis fluid container and mates with the patient line connector, the second connector of the second reusable peritoneal dialysis fluid line is disconnected from the second peritoneal dialysis fluid container and mates with the drainage line connector, and wherein, during the thermal cleansing sequence, the dialysis fluid pump and the dialysis fluid inline heater are actuated.

2. The peritoneal dialysis system of claim 1, further comprising an additional connector provided by the housing, a third reusable peritoneal dialysis fluid line extending from the housing, and a third connector configured to mate with the additional connector for use in the thermal cleaning sequence.

3. The peritoneal dialysis system of claim 2 further includes a fourth fluid line, the fourth fluid line including a fourth connector configured to mate with the additional connector during the peritoneal dialysis treatment.

4. The peritoneal dialysis system according to claim 3, wherein, The fourth fluid line is configured to provide additional peritoneal dialysis fluid for the peritoneal dialysis treatment or is configured to serve as a location for storing effluent samples.

5. The peritoneal dialysis system of claim 1 further includes the first peritoneal dialysis fluid container and the second peritoneal dialysis fluid container, the first peritoneal dialysis fluid container and the second peritoneal dialysis fluid container being configured to be connected to the first connector and the second connector, respectively.

6. The peritoneal dialysis system according to claim 1, wherein, The first connector and the second connector are different from each other.

7. The peritoneal dialysis system of claim 1, further comprising the disposable patient tubing configured for connection to the patient tubing connector and the disposable drainage tubing configured for connection to the drainage tubing connector.

8. The peritoneal dialysis system according to claim 1, wherein, At least one of the first reusable peritoneal dialysis fluid lines or the second reusable peritoneal dialysis fluid line is provided with a cap that is opened and closed to disconnect and connect the first connector from the patient line connector, or to disconnect and connect the second connector from the drainage line connector.

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

10. The peritoneal dialysis system according to claim 1, wherein, The dialysis fluid pump is a piston pump, gear pump, or diaphragm pump, and wherein the reusable pump body of the piston pump, gear pump, or diaphragm pump is configured to receive peritoneal dialysis fluid for pumping.

11. A peritoneal dialysis system, comprising: case; A dialysis fluid pump, the dialysis fluid pump being housed in the housing and including a reusable pump body that receives peritoneal dialysis fluid for pumping; An intra-dialysis fluid heater, the intra-dialysis fluid heater being housed in the housing and including a reusable heater body that receives peritoneal dialysis fluid for heating; A patient line connector, provided by the housing, includes a patient line recirculation cap that allows peritoneal dialysis fluid to be recirculated through the patient line connector when the patient line connector is sealed by the patient line recirculation cap. A drainage line connector, provided by the housing, includes a drainage line recirculation cap that allows peritoneal dialysis fluid to be recirculated through the connector when the connector is sealed by the drainage line recirculation cap. At least one reusable peritoneal dialysis fluid line; At least one heated cleaning connector, supported by the housing and configured to accept one of the at least one reusable peritoneal dialysis fluid lines; as well as A control unit configured to run a thermal cleanup sequence after the peritoneal dialysis treatment, wherein the patient line connector is capped by the patient line recirculation cap, the drainage line connector is capped by the drainage line recirculation cap, each of the at least one reusable peritoneal dialysis fluid line is connected to one of the at least one thermal cleanup connectors, and at least one of the dialysis fluid pump or the dialysis fluid inline heater is actuated during the thermal cleanup sequence.

12. The peritoneal dialysis system according to claim 11, wherein, The control unit is configured to: Using the first and second dialysis fluid temperature measurements, which are obtained under the control of the control unit and heated by the heater, the first peritoneal dialysis fluid flow rate is determined; and The first peritoneal dialysis fluid flow rate determination is compared with the second peritoneal dialysis fluid flow rate determination based on the corresponding actuation of the dialysis fluid pump.

13. The peritoneal dialysis system of claim 11, further comprising at least one cover, the at least one cover being positioned and arranged such that, during the thermal cleaning sequence, the at least one cover releasably and sealingly covers the at least one thermal cleaning connector.

14. The peritoneal dialysis system according to claim 11, wherein, At least one of the patient line recirculation cap or the drainage line recirculation cap includes an internal channel for recirculation.

15. The peritoneal dialysis system of claim 11, further comprising at least one peritoneal dialysis fluid container configured to receive one of the at least one reusable peritoneal dialysis fluid lines.

16. The peritoneal dialysis system of claim 11, further comprising a disposable patient line configured for connection to the patient line connector and a disposable drainage line configured for connection to the drainage line connector.

17. The peritoneal dialysis system according to claim 11, wherein, The control unit is configured to: (i) The dialysis fluid inline heater heats the peritoneal dialysis fluid to at least 70°C or at least 120°C to achieve a thermal cleaning sterilization level, and (ii) the dialysis fluid pump recirculates the heated peritoneal dialysis fluid during the thermal cleaning sequence.

18. The peritoneal dialysis system according to claim 11, wherein, The dialysis fluid pump is a piston pump, gear pump, or diaphragm pump, and wherein the reusable pump body of the piston pump, gear pump, or diaphragm pump is configured to receive peritoneal dialysis fluid for pumping.

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