Peritoneal dialysis system including a patient line filter having a membrane sheet - Patents.com

Abstract

The peritoneal dialysis ("PD") system (10) includes a PD machine (20), a patient line (50) extending from the PD machine (20); a filter housing (102) having an upper housing plate (102u) and a lower housing plate (102l), and a filter set (100) including a filter membrane (112) (such as a sterilizing grade filter membrane or a bacteria reduction filter membrane) located between the upper housing plate (102u) and the lower housing plate (102l), the filter set (100) further including a luminal connector (104) configured to connect to the patient line (50), the luminal connector (104) being connected to the filter housing (102) via at least one of a fresh PD fluid tube (106a) or a used PD fluid tube (106b). A method for manufacturing the filter set (100) is also disclosed.

Description

[Technical field]

[0001] (Priority Claim) This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 291,018, filed December 17, 2021, the entire contents of which are incorporated herein by reference.

[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to medical fluid therapy, and more particularly to filtration of therapy fluid during dialysate therapy. [Background technology]

[0003] A variety of causes can cause a person's renal system to fail. Renal failure results in several physiological disturbances: it is no longer possible to balance water and minerals or to excrete the daily metabolic load. Toxic end products of metabolism such as urea, creatinine, and uric acid can accumulate in the patient's blood and tissues.

[0004] Reduced kidney function, especially kidney failure, is treated by dialysis, which removes waste products, toxins and excess water from the body that normally functioning kidneys would remove. Dialysis treatments for kidney function replacement are vital for many people, as the treatment is life-threatening.

[0005] One type of renal failure therapy is hemodialysis ("HD"), which generally 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 the dialysate or dialysate, causing diffusion.

[0006] Hemofiltration ("HF") is an alternative renal replacement therapy that relies on convective transport of toxins from the patient's blood. HF is achieved by adding replacement or substitution fluid to the extracorporeal circuit during treatment. The replacement fluid, and fluid accumulated by the patient between treatments, is ultrafiltered during HF treatment, providing a convective transport mechanism associated with filtration that is particularly beneficial in removing middle and large molecules.

[0007] Hemodiafiltration ("HDF") is a treatment modality that combines convective and diffusive clearance. HDF, like standard hemodialysis, uses dialysate flowing through a dialyzer to provide diffusive clearance. In addition, replacement solution is delivered directly to the extracorporeal circuit to provide convective clearance.

[0008] Most HD, HF, and HDF treatments are performed in facilities. Today, there is a trend toward home hemodialysis ("HHD"), in part because HHD can be performed daily, providing therapeutic benefits over in-center hemodialysis treatments that are typically performed twice or three times a week. Studies have shown that more frequent treatments remove more toxins and waste products and result in less fluid overload between dialysis sessions than patients receiving less frequent but perhaps longer treatments. Patients receiving more frequent treatments do not experience as many down cycles (fluid and toxin fluctuations) as in-center patients who build up two or three days' worth of toxins before treatment. In certain areas, the nearest dialysis facility may be many miles away from the patient's home, causing door-to-door treatment times to consume a large portion of the day. Treatments at facilities closer to the patient's home may also consume a large portion of the patient's day. HHD can be performed at night or during the day, when the patient is relaxing, working, or otherwise productive.

[0009] Another type of renal failure therapy is peritoneal dialysis ("PD"), in which dialysis solution, also called dialysate or PD fluid, is infused through a catheter into the patient's peritoneal cavity. The PD fluid contacts the peritoneal membrane within the patient's peritoneal cavity. Waste, toxins and excess water enter the PD fluid from the patient's bloodstream through capillaries in the peritoneum by diffusion and osmosis, i.e., an osmotic gradient across the membrane is created. An osmotic agent in the PD fluid provides the osmotic gradient. The spent PD fluid is pumped out of the patient, removing the waste, toxins and excess water from the patient. This cycle may be repeated, for example, multiple times.

[0010] There are various types of peritoneal dialysis therapies, 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, in which the patient manually connects an implanted catheter to a drain, allowing spent PD fluid to drain from the patient's peritoneal cavity. The patient then switches the fluid communication so that the patient catheter is in communication with a bag of fresh PD fluid and infuses fresh PD fluid through the catheter into the patient. The patient disconnects the catheter from the bag of fresh PD fluid, allowing the PD fluid to dwell in the patient's peritoneal cavity, where waste, toxins, and excess water are transported. After a dwell period, the patient repeats the manual dialysis procedure, for example, four times a day. Manual peritoneal dialysis requires significant time and effort from the patient, leaving significant room for improvement.

[0011] APD is similar to CAPD in that the dialysis treatment involves drain, fill and dwell cycles. However, APD devices perform these cycles automatically, usually while the patient sleeps. APD devices eliminate the need for the patient to manually perform the treatment cycles and transport supplies during the day. APD devices fluidly connect to an implanted catheter, a source or bag of fresh PD fluid, and a fluid drain. The APD device pumps fresh PD fluid from the dialysate source through the catheter and into the patient's peritoneal cavity. APD devices also allow the PD fluid to dwell within the cavity, allowing transport of waste, toxins and excess water to occur. The source may contain multiple liters of dialysate, including several solution bags.

[0012] The APD machine pumps spent PD fluid from the patient's peritoneal cavity and out through the catheter. As with the manual process, several drain, fill and dwell cycles occur during dialysis. A "final fill" may occur at the end of an APD treatment. The final fill fluid may remain in the patient's peritoneal cavity until the start of the next treatment, or it may be manually emptied at some point during the day.

[0013] PD fluid needs to be sterile or very close to sterile because it is infused into the patient's peritoneal cavity and is therefore considered a drug. Although bagged PD fluid is usually adequately sterilized for treatment, PD fluid made on-line, or PD devices or cyclers that employ disinfection, may require further sterilization.

[0014] Therefore, there is a need for an effective, low-cost method of providing additional sterilization to fresh PD fluid before it is delivered to the patient. Summary of the Invention [Means for solving the problem]

[0015] The present disclosure provides a peritoneal dialysis ("PD") system having a PD device or cycler that pumps fresh PD fluid to a patient through a patient line and removes spent PD fluid from the patient via the patient line. The patient line may be reusable or disposable, and in either case operates with and is in fluid communication with a filter set. If the patient line is reusable, the reusable patient line is connected to the filter set during treatment. If the patient line is disposable, in one embodiment, the filter set is integrated into the disposable patient line. In either configuration, the distal end of the filter set may be connected to a patient transfer set, which is in fluid communication with the patient's indwelling catheter.

[0016] The PD device or cycler may include a durable PD fluid pump that pumps PD fluid through itself without the use of disposable components, or it may include a disposable-type PD fluid pump that includes a pump actuator that actuates disposable, fluid-contacting pumping components such as peristaltic pump tubing and a flexible pump chamber. The PD device or cycler may also include a number of valves, which may similarly be flow-through and durable, not operated with disposable components, or disposable-type valves with valve actuators that actuate disposable, fluid-contacting valve components such as tubing segments or cassette-based valve seats.

[0017] The pumps and valves are under the automatic control of a control unit provided by the device or cycler. In an embodiment, the valves include a fresh PD fluid valve that the control unit opens to allow the PD fluid pump to pump fresh PD fluid to the patient through the fresh PD fluid lumen of the dual lumen patient line. The valves also include a spent PD fluid valve that the control unit opens to allow the PD fluid pump to pump spent PD fluid from the patient through the spent PD fluid lumen of the dual lumen patient line. It should be understood that while a single PD fluid pump may be used, alternatively, dedicated fresh and spent PD fluid pumps may be used. A single PD fluid pump may also include multiple pump chambers for more continuous PD fluid flow.

[0018] The fresh and spent PD fluid lumens may again be reusable or disposable. In instances where the fresh and spent PD fluid lumens are reusable, the lumens terminate in a patient line connector that connects to the luminal connector of the filter set. The luminal connector in one embodiment includes a fresh PD fluid port for communicating with the fresh PD fluid lumen of the dual lumen patient line and a spent PD fluid port for communicating with the spent PD fluid lumen of the dual lumen patient line. The luminal connector also includes threads for threadably engaging mating threads of the patient line connector. Threading of the patient line connector into the luminal connector seals (e.g., via one or more gaskets in one embodiment) the mating ports of the patient line connector to the fresh and spent PD fluid ports of the luminal connector.

[0019] A pair of tubes, including a tube of fresh PD fluid and a tube of spent PD fluid, extend from the luminal connector to the filter housing. The tubes of fresh PD fluid and spent PD fluid, in one embodiment, are rigid and bent to position the luminal connector and the filter housing relative to one another in a desired manner. The filter housing, in one embodiment, is a thin structure having upper and lower housing plates. Each plate has a slightly raised section for receiving PD fluid. The raised section, in one embodiment, is surrounded by the periphery of the upper and lower plates. The plates may also be molded to each have a cylindrical tube receiving portion. The cylindrical tube receiving portion may be angled to match the bend angle of the tube of fresh or spent PD fluid to be received. The plates may be molded plastic and may be sealed to one another along their mating peripheries. The periphery of one of the upper or lower plates may be formed with a polygonal, e.g., rectangular, tongue that fits into a similarly shaped groove formed in the other of the upper or lower plate. The tongue and groove fit helps to center the upper and lower plates together during the sealing process. The upper and lower plates may be ultrasonically sealed, heat sealed, or solvent bonded to one another.

[0020] The filter membrane is sealed along its periphery between the upper and lower plates. The filter membrane, in one embodiment, is a flat sheet that roughly bisects the upper and lower plates. The filter membrane may be a sterilizing grade or bacteria reducing hydrophilic membrane, which may be formed with porous walls having a pore size of approximately 0.2 microns through which fresh PD fluid flows for further filtration.

[0021] The lower plate may be molded with a second cylindrical tube receiving portion for receiving the transfer set side tubing that extends to the transfer set side connector. The transfer set side tubing, like the fresh and used PD fluid tubing, may be stiff and bent so that the transfer set side connector and the filter housing are angled relative to one another in a desired manner. The second cylindrical tube receiving portion may similarly be angled to match the angle formed by the transfer set side tubing. The transfer set side connector then connects directly to a mating connector on the patient's transfer set or directly to a mating connector of a short tube placed between the filter housing and the patient's transfer set. The transfer set side connector may alternatively simply be a port with a short tube extending to it for welding to the port.

[0022] During patient fill, fresh PD fluid flows from the fresh PD fluid lumen, through the lumen connector, through the fresh PD fluid tubing, and into the raised compartment of the upper plate. Inside the raised compartment, fresh PD fluid is forced under positive pressure from the PD fluid pump through the filter membrane sheet into the raised compartment of the lower plate. The filter membrane sheet is sized to provide sufficient filtration over multiple patient fills while being small enough to avoid discomfort to the patient, who is likely asleep during treatment.

[0023] The final filtered fresh PD fluid exits the lower plate's raised section through the transfer set tubing and transfer set connector into the patient's transfer set, either directly or via a short flexible tube. The hydrophilic nature of the filter membrane prevents air from migrating across it once it is fully wetted with fresh PD fluid, thus serving a secondary end-stage air removal purpose. However, it is also contemplated to provide one or more hydrophobic membranes upstream of the filter membrane (from the perspective of the fresh PD fluid), for example along the surface of the upper plate, if necessary. The one or more hydrophobic membranes would allow air to be vented to the atmosphere before the fresh PD fluid flows through the filter membrane.

[0024] The spent PD fluid removed through the patient's transfer set enters the raised compartment of the lower plate of the filter set via the transfer set connector and the transfer set tubing, flows from the lower peritoneal cavity under negative pressure by the PD fluid pump, through the spent PD fluid tubing, through the spent PD fluid port and spent PD fluid lumen of the luminal connector, and returns to the PD device or cycler. The PD device or cycler pumps the spent PD fluid under positive pressure to drain. The spent PD fluid contacts the underside of the filter membrane sheet, but in a contacting manner, so that fibrin, proteins and other particulates in the patient's effluent are less likely to be captured by and trapped on the filter membrane. Thus, the filter membrane remains usable during multiple fills of therapy before being discarded with the filter set.

[0025] In a first aspect of the present disclosure, which in light of the disclosure set forth herein may be combined with any other aspect or portion thereof described herein without limiting the disclosure in any respect, a peritoneal dialysis ("PD") system includes a PD device; a patient line extending from the PD device; and a filter set including a filter housing having an upper housing plate and a lower housing plate and a filter membrane located between the upper housing plate and the lower housing plate, the filter set further including a luminal connector configured to connect to the patient line, the luminal connector being connected to the filter housing via at least one of a tube of fresh PD fluid or a tube of used PD fluid.

[0026] In a second aspect of the present disclosure, which may be combined with any other aspect or portion thereof described herein, the patient line is a dual lumen patient line including a fresh PD fluid lumen disposed in fluid communication with the fresh PD fluid tube of the filter set, and the dual lumen patient line further includes a spent PD fluid lumen disposed in fluid communication with the spent PD fluid tube of the filter set.

[0027] In a third aspect of the present disclosure, which may be combined with any other aspect or portion thereof described herein, the fresh PD fluid lumen is disposed in fluid communication with the fresh PD fluid tubing of the filter set via a fresh PD fluid port of the luminal connector, and the spent PD fluid lumen is disposed in fluid communication with the spent PD fluid tubing of the filter set via a spent PD fluid port of the luminal connector.

[0028] In a fourth aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, the fresh PD fluid port and the spent PD fluid port are surrounded by a shroud of the luminal connector, and the shroud includes threads for mating with a patient line connector.

[0029] In a fifth aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, the fresh PD fluid port and the spent PD fluid port are surrounded by a shroud of the luminal connector, the shroud including a keyed opening for receiving a patient line connector in a desired orientation.

[0030] In a sixth aspect of the present disclosure, which may be combined with any other aspect or portion thereof described herein, the PD system includes a compressible gasket configured to seal around a fresh PD fluid port and a used PD fluid port between the luminal connector and the patient line connector.

[0031] In a seventh aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, at least one of the fresh PD fluid tube or the used PD fluid tube is rigid.

[0032] In an eighth aspect of the present disclosure, which may be combined with any other aspect or portion thereof described herein, at least one of the fresh PD fluid tube or the used PD fluid tube is bent such that the luminal connector and the filter housing are positioned relative to each other in a desired manner.

[0033] In a ninth aspect of the present disclosure, which may be combined with any other aspect or portion thereof described herein, the filter membrane is a sheet-like hydrophilic membrane, and the upper and lower housing plates include raised compartments for receiving PD fluid.

[0034] In a tenth aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, an upper housing plate and a lower housing plate are formed and sealed together with a filter membrane to form a filter housing by a combined process of online sealing and deep drawing.

[0035] In an eleventh aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, the filter housing is configured to allow spent PD fluid to flow tangentially along the filter membrane.

[0036] In a twelfth aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, the PD system includes at least one hydrophobic membrane positioned to evacuate air from the fresh PD fluid upstream of the filter membrane.

[0037] In a thirteenth aspect of the present disclosure, which may be combined with any other aspect or portion thereof described herein, the filter set is configured to connect directly to a patient transport set, or the filter set includes a flexible tube configured to connect to a patient transport set.

[0038] In a fourteenth aspect of the present disclosure, which may be combined with any other aspect or portion thereof described herein, the filter set includes a transport set side connector for connecting to a patient's transport set, the transport set side connector being connected to the filter housing via a transport set side tubing.

[0039] In a fifteenth aspect of the present disclosure, which may be combined with any other aspect or portion thereof described herein, the PD device includes a pressure sensor positioned to sense the pressure of fresh PD fluid downstream of the filter membrane during patient fill.

[0040] In a sixteenth aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, the filter membrane is a sterilizing grade filter membrane or a bacteria reducing filter membrane.

[0041] In a seventeenth aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, a filter set for connecting to a patient line includes a filter housing including an upper housing plate and a lower housing plate, a filter membrane in the form of a sheet located between the upper housing plate and the lower housing plate, and a luminal connector configured to connect to the patient line, the luminal connector being connected to the filter housing via at least one of a tube of fresh PD fluid or a tube of used PD fluid.

[0042] In an eighteenth aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, a method of manufacturing a filter set for connection to a patient line includes heating at a softening temperature and applying a vacuum to form a plurality of upper and lower housing plates, spreading a filter membrane in the form of a sheet between each of the formed upper housing plates and each of the formed lower housing plates, and heating at a sealing temperature to seal the filter membrane in place and sealing the upper housing plate to the lower housing plate.

[0043] In a nineteenth aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, spreading the filter membranes includes spreading a filter membrane sheet dimensioned to provide multiple filter membranes between an upper housing plate and a lower housing plate during formation, and separating the filter set after heating and sealing the upper housing plate to the lower housing plate.

[0044] In a twentieth aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, a method of manufacturing includes separating a plurality of formed upper housing plates and a formed lower housing plate, drilling at least one opening for at least one hydrophobic membrane, and sealing the at least one hydrophobic membrane over the at least one opening before heating and sealing the upper housing plate to the lower housing plate. The drilling may be performed during the separating.

[0045] In a twenty-first aspect of the present disclosure that may be combined with any other aspect or portion thereof described herein, the sealing temperature is higher than the softening temperature.

[0046] In a twenty-second aspect of the present disclosure, which may be combined with any other aspect or portion thereof described herein, any of the features, functions, and alternatives described in connection with any one or more of Figures 1 to 4 may be combined with any of the features, functions, and alternatives described in connection with any other of Figures 1 to 4.

[0047] In light of the above aspects and the present disclosure herein, one advantage of the present disclosure is to provide a filter set that operates with a dual lumen patient line.

[0048] Another advantage of the present disclosure is to provide a filter set that filters fresh PD fluid and allows used PD fluid to pass through without clogging.

[0049] A further advantage of the present disclosure is to provide a filter set having a filtration capacity that is easily adjustable by varying the size of the filter membrane sheets.

[0050] Yet another advantage of the present disclosure is that it provides a filter set that is easy to manufacture and has a venting feature that functions regardless of filter orientation.

[0051] Yet another advantage of the present disclosure is to provide a filter set having a filter housing that may be manufactured using a continuous on-line deep drawing process.

[0052] Further features and advantages will be described in and will be apparent from the following detailed description and drawings. The features and advantages described herein are not all-inclusive, and many further features and advantages will be apparent to those skilled in the art, particularly upon consideration of the drawings and description. It is not necessary for any particular embodiment to have all the advantages described herein, and it is expressly contemplated that each advantageous embodiment may be separately claimed. Furthermore, it should be noted that the language used herein has been selected primarily for readability and educational purposes, and is not intended to limit the scope of the subject matter of the present invention. [Brief description of the drawings]

[0053] [Figure 1] FIG. 1 is a schematic diagram of one embodiment of a peritoneal dialysis system including a patient line filter set having a filter membrane sheet of the present disclosure.

[0054] [Diagram 2] FIG. 2 is a perspective view of one embodiment of a patient line filter set having a filter membrane sheet of the present disclosure.

[0055] [Diagram 3] FIG. 3 is a perspective view of the patient line filter set of FIG. 2 during patient fill.

[0056] [Figure 4] FIG. 4 is a perspective view of the patient line filter set of FIG. 2 during patient drainage. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] Referring now to the drawings, and in particular to FIG. 1, a peritoneal dialysis ("PD") system 10 is illustrated. The PD system 10 includes a PD machine or cycler 20 that pumps fresh PD fluid to a patient P through a patient line 50 and removes spent PD fluid from the patient P via the patient line 50. The patient line 50 may be reusable or disposable, and in either case operates in conjunction with and is in fluid communication with a filter set 100. If the patient line 50 is reusable, the reusable patient line is connected to the filter set 100 during treatment. If the patient line 50 is instead disposable, in one embodiment, the filter set 100 is merged into or formed with the disposable patient line 50. In either configuration, the distal end of the filter set 100 may be connected to a patient transport set 58, which is in turn in fluid communication with the patient P's indwelling catheter.

[0058] The PD device or cycler 20 may include a housing 22 that provides a durable PD fluid pump 24 that pumps PD fluid through itself without the use of disposable components. Examples of durable pumps that may be used for the PD fluid pump 24 include piston pumps, gear pumps, and centrifugal pumps. Certain durable pumps, such as piston pumps, are inherently precise, such that the device or cycler 20 does not require additional volume control components. Other durable pumps, such as gear pumps and centrifugal pumps, may not be precise, such that the device or cycler 20 provides a volume control device, such as one or more flow meters (not shown).

[0059] Pump 24 may alternatively be a disposable type PD fluid pump that includes a pump actuator that actuates disposable fluid-contacting pumping components, such as peristaltic pump tubing and flexible pump chambers. Examples of disposable PD fluid pumps that may be used for PD fluid pump 24 include rotary or linear peristaltic pump actuators that actuate tubing, pneumatic pump actuators that actuate cassette seats, electromechanical pump actuators that actuate cassette seats, and platen pump actuators that actuate tubing. While a single PD fluid pump 24 may be used, it should be understood that alternatively, dedicated fresh and used PD fluid pumps may be used. A single PD fluid pump 24 may also include multiple pump chambers for a more continuous PD fluid flow.

[0060] The PD device or cycler 20 may also include a number of valves 26a, 26b, 26m, 26n, which may also be flow-through and durable, not operating with disposable components, or disposable type valves with valve actuators that actuate disposable fluid-contacting valve components (such as tubing segments or cassette-based valve seats). Examples of durable valves that may be used for the valves 26a, 26b, 26m, 26n include flow-through solenoid valves. Such valves may be two-way or three-way valves. Examples of disposable valves that may be used for the valves 26a, 26b, 26m, 26n include solenoid pinch valves that pinch closed flexible tubing, pneumatic valve actuators that actuate cassette seats, and electromechanical valve actuators that actuate cassette seats.

[0061] Apparatus or cycler 20 will likely include a number of valves 26a-26n. For ease of illustration, apparatus or cycler 20 is shown as having fresh PD fluid valve 26a, which is controlled to open to allow PD fluid pump 24 to pump fresh PD fluid under positive pressure through fresh PD fluid lumen 52 of dual lumen patient line 50 to patient P. The valves also include spent PD fluid valve 26b, which is controlled to open to allow PD fluid pump 24 to draw spent PD fluid under negative pressure from patient P through spent PD fluid lumen 54 of dual lumen patient line 50. Valve 26m is provided to allow selective access to one or more PD fluid sources, and valve 26n is provided to allow selective access to a drain, such as a drain container or a house drain.

[0062] The device or cycler 20 in the illustrated embodiment also includes pressure sensors, such as pressure sensors 28a, 28b. Pressure sensor 28a is located immediately downstream of fresh PD fluid valve 26a, and pressure sensor 28b is located immediately upstream of spent PD fluid valve 26b. Thus, pressure sensor 28a can sense the pressure in the fresh PD fluid lumen 52 of dual lumen patient line 50 even when fresh PD fluid valve 26a is closed, and pressure sensor 28b can sense the pressure in the spent PD fluid lumen 54 of dual lumen patient line 50 even when spent PD fluid valve 26b is closed. Additionally, pressure sensor 28a is positioned to sense the fresh PD fluid pressure upstream of the filter membrane discussed herein during patient fill. Pressure sensor 28b, perhaps more importantly, is positioned to sense the fresh PD fluid pressure downstream of the filter membrane discussed herein during patient fill.

[0063] The pump 24 and valves 26a, 26b in the illustrated embodiment are under the automated control of a control unit 40 provided by the device or cycler 20 of the system 10 to which the pressure sensors 28a, 28b (and other sensors) output. The control unit 40 in the illustrated embodiment includes one or more processors 42, one or more memories 44, and a video controller 46. The control unit 40 receives, stores, and processes signals or outputs from the pressure sensors 28a, 28b and other sensors provided by the device or cycler 20, such as one or more temperature sensors 30 and one or more conductivity sensors (not shown). Control unit 40 uses pressure feedback from one or more of pressure sensors 28a, 28b to control PD fluid pump 24 to pump dialysis fluid at a desired pressure or within safe pressure limits (e.g., within 0.21 bar (3 psig) of positive pressure into the patient's peritoneal cavity and within -10 bar (-1.5 psig) of negative pressure from the patient's peritoneal cavity).

[0064] The control unit 40 uses temperature feedback from one or more temperature sensors 30 to control a heater 32, such as an in-line heater, to heat the fresh PD fluid to a desired temperature (e.g., body temperature or 37° C.). In one embodiment, the heater 32 is further used to heat a disinfectant fluid (such as fresh PD fluid) to disinfect the PD fluid pump 24, valves 26a-26n, heater 32, and all reusable fluid lines within the device or cycler 20 and prepare the device or cycler for the next treatment. The additional filtration discussed herein provides an additional layer of protection in addition to the heated fluid disinfection to ensure that the PD fluid is safe for delivery to the patient P.

[0065] The video controller 46 of the control unit 40 interacts with a user interface 48 of the device or cycler 20, which may include a display screen operated with one or more electromechanical buttons, such as a touch screen and / or membrane switches. The user interface 48 may also include one or more speakers for outputting alerts, warnings, and / or voice guidance commands. The user interface 48 may be provided with the device or cycler 20 as illustrated in FIG. 1 and / or may be a remote user interface operating with the control unit 40. The control unit 40 may also include a transceiver (not shown) and a wired or wireless connection to a network (e.g., the Internet) for transmitting treatment data to, and receiving prescription orders from, a physician or clinician server that interacts with a physician or clinician's computer.

[0066] 1 and 2, as discussed above, the fresh PD fluid lumen 52 and the spent PD fluid lumen 54 of the dual lumen patient line 50 may again be reusable or disposable. In instances where the dual lumen patient line 50 is reusable, the lumens terminate in a connector 56 that connects to a luminal connector 104 of the filter set 100. The luminal connector 104 in one embodiment includes a fresh PD fluid port 104a for communicating with the fresh PD fluid lumen 52 of the dual lumen patient line 50 and a spent PD fluid port 104b for communicating with the spent PD fluid lumen 54 of the dual lumen patient line 50. The fresh PD fluid port 104a and the spent PD fluid port 104b are surrounded by a shroud 104s of the luminal connector 104, which is formed with threads 104c for threadedly engaging mating threads of the patient line connector 56. Threading of the patient line connector 56 into the luminal connector 104 seals mating ports (not shown) of the patient line connector 56 to fresh PD fluid port 104a and used PD fluid port 104b of the luminal connector 104 via one or more compressible gaskets (not shown, e.g., silicone or other suitable rubber gaskets, etc.) in one embodiment. In the illustrated embodiment, the front face of the shroud 104s is formed with a keyed opening 104k. The patient line connector 56 is formed with a mating key so that the patient line connector can only be introduced into the shroud 104s in the proper orientation to align the fresh PD fluid lumen 52 with the fresh PD fluid port 104a and the used PD fluid lumen 54 with the used PD fluid port 104b.

[0067] A pair of tubes, including a tube of fresh PD fluid 106a and a tube of used PD fluid 106b, extend from the luminal connector 104 to the filter housing 102. The tubes of fresh PD fluid 106a and used PD fluid 106b are rigid in one embodiment, which are bent to position the luminal connector 104 and the filter housing 102 relative to one another in a desired manner. In the illustrated embodiment, the luminal connector 104 is molded with cylindrical tube receiving portions 104d, 104e, which receive the tubes of fresh PD fluid 106a and used PD fluid 106b, respectively. The proximal ends of the tubes of fresh PD fluid 106a and used PD fluid 106b, respectively, may be sealed within the cylindrical tube receiving portions 104d, 104e ultrasonically, by heat sealing, and / or by adhesion, for example, by solvent bonding. In an alternative embodiment, the fresh PD fluid tube 106 a and the spent PD fluid tube 106 b are molded with the luminal connector 104 .

[0068] 3 and 4, the filter housing 102, in one embodiment, is a thin structure having an upper housing plate 102u and a lower housing plate 102l. Each plate 102u, 102l has a slightly raised section 102r for receiving PD fluid. The raised section 102r, in one embodiment, is surrounded by the outer periphery 102p of the upper plate 102u and the lower plate 102l. The plates 102u, 102l may also be shaped to each have a respective cylindrical tube receiving portion 102a, 102b. The cylindrical tube receiving portions 102a, 102b may be angled to match the bend angle of the tube of fresh PD fluid 106a or the tube of used PD fluid 106b being received. The distal ends of the fresh PD fluid tube 106a and the used PD fluid tube 106b may be sealed within the cylindrical tube receiving portions 102a, 102b, respectively, ultrasonically, by heat sealing, and / or by adhesive bonding, for example, by solvent bonding.

[0069] The plates 102u, 102l may be molded plastic and may be sealed together along their mating perimeters 102p ultrasonically, by heat sealing, and / or by adhesive bonding, for example, by solvent bonding. The perimeter of one of the upper plate 102u or lower plate 102l may be formed with a polygonal (e.g., rectangular) tongue 102t that fits into a similarly shaped groove 102g formed in the other of the upper plate 102u or lower plate 102l. The mating tongue and groove helps center the upper and lower plates 102u, 102l together during the sealing process.

[0070] The filter membrane 112 is sealed along its periphery between the outer periphery 102p of the upper plate 102u and the lower plate 102l. The filter membrane 112 is a flat sheet that, in the illustrated embodiment, roughly bisects the raised section 102r of the upper plate 102u and the lower plate 102l. The filter membrane 112 may be a sterilizing grade or bacteria reducing hydrophilic membrane, which may be formed with porous walls having a pore size of about 0.2 microns through which the fresh PD fluid flows for further filtration. The filter membrane sheet 112 may be made of, for example, polysulfone or polyethersulfone mixed with polyvinylpyrrolidone.

[0071] In the illustrated embodiment, the lower plate 102l is molded with a second lower cylindrical tube receiving portion 102c for receiving the transfer set side tubing 106c that extends to the transfer set side connector 108. The transfer set side tubing 106c, like the fresh PD fluid tube 106a and the used PD fluid tube 106b, is rigid and can be bent so that the transfer set side connector 108 and the filter housing 102 are angled relative to one another in a desired manner. The second lower cylindrical tube receiving portion 102c can likewise be angled to match the angle formed by the transfer set side tubing 106c. Any of the filter housing 102, luminal connector 104, tubing 106a-106c, and transfer set connector 108 may be made from any one or more plastics, such as polystyrene ("PS"), polycarbonate ("PC"), a blend of polycarbonate and acrylonitrile butadiene styrene ("PC / ABS"), polyvinyl chloride ("PVC"), polyethylene ("PE"), polypropylene ("PP"), a polyester such as polyethylene terephthalate ("PET"), or polyurethane ("PU").

[0072] The transfer set side connector 108 connects directly to a mating connector on the patient transfer set 58 or to a mating connector on a short flexible tube 110 disposed between the filter housing 102 and the patient transfer set 58. The transfer set side connector 108 may include a port (not shown) and a threaded shroud 108a for a luer-type connection to a mating connector. The transfer set side connector 108 may alternatively simply be a port with the short flexible tube 110 extending to the port for welding to the port. Similarly, if the dual lumen patient line 50 is disposable, the lumen side connector 104 may alternatively simply include ports (e.g., fresh PD fluid port 104a and used PD fluid port 104b) with the fresh PD fluid lumen 52 and used PD fluid lumen 54 extending to the port for welding to the port.

[0073] The filter housings 102 may start with an array having blanks for multiple upper plates 102u formed together as a large blank, and blanks for the same number of lower plates 102l formed together as a large blank. The array of large blanks is stacked on top of each other and fed by a combination process of on-line sealing and deep drawing with rollers. At the same time, a large sheet of material for forming the multiple filter membranes 112 is fed between the large blanks for the multiple upper plates 102u and the large blanks for the multiple lower plates 102l. The deep drawing process forms the upper and lower raised sections 102r for each filter housing 102. The simultaneous sealing process seals the perimeter 102p of the upper plates 102u and the lower plates 102l for each filter housing 102, thereby sealing the filter membranes 112 in place. The drawn and sealed large array is then cut or slit into separate individual filter housings 102. Cylindrical tube receiving portions 102a-102c and other components of filter set 100 may be secured together after separation, for example by gluing, using the roller process described above.

[0074] In a simplified embodiment of the manufacturing process for the filter housing 102, the degassing hydrophobic membrane 114 is not provided and the air is treated as described below. The manufacturing process is then carried out as described above, in one embodiment, using a single tool to thermoform the upper plate 102u and the lower plate 102l and apply a vacuum to each of the large sheets of material. In an embodiment, drawing is performed before sealing, as drawing requires a lower temperature. The drawing temperature used with the tool depends at least in part on the material used for the filter housing 102. The temperature in one embodiment need only be high enough to soften the material for drawing or thermoforming. In a particular example, a tool temperature in the range of 130-145°C may be used for PP, a tool temperature in the range of 120-160°C may be used for PS, a tool temperature in the range of 70-90°C may be used for PET, and a tool temperature in the range of 150-180°C may be used for PC. The vacuum pressure applied by the tool for thermoforming in the manufacturing process of the filter housing 102 may be selected from a range of, for example, -100 millibar gauge ("mbar(g)") to -900 mbar(g) (-1.5 psig to -13 psig). Sealing using a single tool may follow drawing, which may require higher temperatures, for example, 200°C to 250°C.

[0075] For the filter housing 102 providing one or more degassing hydrophobic membranes 114, the manufacturing process may be different. Here, the upper plate 102u and the lower plate 102l may pass through a heating zone separately and then are thermoformed by applying a tool having a stamp and a mold that forms the upper and lower raised sections 102r. For the upper plate 102u, the stamp cuts or punches one or more openings for the one or more hydrophobic membranes 114, and then the one or more membranes are sealed to the inside of the upper plate 102u by any of the techniques described herein, in one embodiment. The formed upper and lower plates 102u and 102l and the filter membrane sheet 112 are then joined and sealed in a separate sealing tool.

[0076] Subsequent finishing steps can be the same whether or not at least one hydrophobic membrane 114 is provided. The filter housings 102 can be separated from one another using a die cutter. A cut perpendicular to the direction of travel of the belt or roller can be made by a roller featuring a vertical blade. The cylindrical tube receiving parts 102a-102c and other components of the filter set 100 can be fixed to the filter housing 102 after separation, for example by gluing. Gluing the hydrophobic membrane 114 to the outside of the filter housing 102 is also an option, but has the disadvantage that the membrane is not protected from accidental contact and damage by the patient or caregiver.

[0077] During patient fills with filter set 100, fresh PD fluid flows from fresh PD fluid lumen 52, through lumen connector 104, through fresh PD fluid tubing 106a, and into raised section 102r of upper plate 102u. Inside raised section 102r, fresh PD fluid is forced under positive pressure from PD fluid pump 24 through filter membrane sheet 112 into raised section 102r of lower plate 102l. Filter membrane sheet 112 is sized to provide sufficient filtration over multiple patient fills while being small enough to avoid discomfort to the patient, who is likely to be asleep during treatment.

[0078] The final filtered fresh PD fluid exits the raised section 102r of the lower plate 102l through the second lower cylindrical tube receiver 102c, the transfer set side tube 106c and the transfer set side connector 108 into the patient transfer set 58, either directly or via a short flexible tube 110. The hydrophilic nature of the filter membrane 112 prevents air from migrating across it once the membrane is fully wetted with fresh PD fluid, thus serving a secondary end-stage air removal purpose. However, if necessary, it is also contemplated to provide one or more hydrophobic membranes 114 upstream of the filter membrane 112 (from the perspective of the fresh PD fluid), along the surface of the upper plate 102u, for example, as illustrated in Figures 2-4. The one or more hydrophobic membranes 114 allow air to be vented to the atmosphere before the fresh PD fluid flows through the filter membrane sheet 112. The hydrophobic membrane 114 may be constructed of, for example, polytetrafluoroethylene ("PTFE").

[0079] Spent PD fluid removed through the patient transport 58 set enters the raised section 102r of the lower plate 102l of the filter set 100 via the transfer set connector 108 and the transfer set tubing 106c, and flows from the lower raised section 102r under negative pressure from the PD fluid pump 24, through the spent PD fluid tubing 106b, through the spent PD fluid port 104b of the lumen connector 104 and the spent PD fluid lumen 54, and back to the PD device or cycler 20. The PD device or cycler 20 pumps the spent PD fluid under positive pressure from the PD fluid pump 24 to drain via the drain line 60. The spent PD fluid contacts the underside of the filter membrane 112 sheet, but in a tangential manner, so that fibrin, proteins and other particulates in the patient effluent are less likely to be trapped by or on the filter membrane. Thus, filter membrane 112 remains usable for multiple fills of therapy before being discarded along with filter set 100.

[0080] It should be understood that various variations and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. It is therefore intended that any or all such changes and modifications may be covered by the appended claims. For example, while dual lumen patient line 50 is shown to operate with fresh PD fluid port 104a and used PD fluid port 104b of luminal connector 104, the patient line may alternatively be a single lumen patient line that communicates with a single port in luminal connector 104, which may communicate with both fresh PD fluid tube 106a and used PD fluid tube 106b. Here, check valves may be sealed and oriented within fresh PD fluid tube 106a and used PD fluid tube 106b such that fresh PD fluid is prevented from flowing into used PD fluid tube 106b and used PD fluid is prevented from flowing through fresh PD fluid tube 106a.

Claims

1. A peritoneal dialysis ("PD") system (10), comprising: a PD device (20); a patient line (50) extending from the PD device (20); a filter set (100) including a filter housing (102) having an upper housing plate (102u) and a lower housing plate (102l), and a filter membrane (112) located between the upper housing plate (102u) and the lower housing plate (102l); Equipped with The PD system (10) further includes a luminal connector (104) configured to connect to the patient line (50), the luminal connector (104) being connected to the filter housing (102) via at least one of a fresh PD fluid tube (106a) or a used PD fluid tube (106b).

2. 2. The PD system of claim 1, wherein the patient line is a dual lumen patient line, the dual lumen patient line including a fresh PD fluid lumen disposed in fluid communication with the fresh PD fluid tubing of the filter set, and the dual lumen patient line further including a spent PD fluid lumen disposed in fluid communication with the spent PD fluid tubing of the filter set.

3. 3. The PD system (10) of claim 2, wherein the fresh PD fluid lumen (52) is arranged in fluid communication with the fresh PD fluid tubing (106a) of the filter set (100) via a fresh PD fluid port (104a) of the luminal connector (104), and the used PD fluid lumen (54) is arranged in fluid communication with the used PD fluid tubing (106b) of the filter set (100) via a used PD fluid port (104b) of the luminal connector (104).

4. 4. The PD system (10) of claim 3, wherein the fresh PD fluid port (104a) and the used PD fluid port (104b) are surrounded by a shroud (104s) of the luminal connector (104), and the shroud (104s) includes threads for mating with a patient line connector.

5. 5. The PD system (10) of claim 3 or 4, wherein the fresh PD fluid port (104a) and the used PD fluid port (104b) are surrounded by a shroud (104s) of the luminal connector (104), the shroud (104s) including a keyed opening (104k) for receiving a patient line connector in a desired orientation.

6. 5. The PD system (10) of claim 3 or 4, comprising a compressible gasket configured to seal around the fresh PD fluid port and the used PD fluid port (104a, 104b) between the luminal connector (104) and a patient line connector.

7. The PD system (10) of any one of claims 1 to 4, wherein the at least one of the fresh PD fluid tubing (106a) or the used PD fluid tubing (106b) is rigid.

8. The PD system (10) of any one of claims 1 to 4, wherein at least one of the fresh PD fluid tubing (106a) or the used PD fluid tubing (106b) is bent so that the luminal connector (104) and the filter housing (102) are positioned relative to each other in a desired manner.

9. 5. The PD system (10) of claim 1, wherein the filter membrane (112) is a sheet-like hydrophilic membrane, and the upper housing plate (102u) and the lower housing plate (102l) include raised compartments (102r) for receiving PD fluid.

10. 5. The PD system (10) of claim 1, wherein the upper housing plate (102u) and the lower housing plate (102l) are formed and sealed together with the filter membrane (112) to form the filter housing (102) by a combined process of online sealing and deep drawing.

11. The PD system (10) of any one of claims 1 to 4, wherein the filter housing (102) is configured to allow spent PD fluid to flow tangentially along the filter membrane (112).

12. 5. The PD system (10) of claim 1, comprising at least one hydrophobic membrane (114) positioned upstream of the filter membrane (112) to expel air from the fresh PD liquid.

13. The PD system (10) of any one of claims 1 to 4, wherein the filter set (100) is configured to connect directly to a patient transport set, or the filter set (100) includes a flexible tube (110) configured to connect to the patient transport set.

14. 5. The PD system of claim 1, wherein the filter set includes a transfer set connector for connecting to a patient's transfer set, the transfer set connector being connected to the filter housing via a transfer set tubing.

15. The PD system (10) of any one of claims 1 to 4, wherein the PD device (20) includes a pressure sensor (28b) positioned to sense the pressure of fresh PD fluid downstream of the filter membrane (112) during patient filling.

16. The PD system (10) of any one of claims 1 to 4, wherein the filter membrane (112) is a sterilizing grade filter membrane or a bacteria reducing filter membrane.

17. A filter set (100) for connection to a patient line, said filter set (100) comprising: a filter housing (102) including an upper housing plate (102u) and a lower housing plate (102l); a filter membrane (112) in the form of a sheet located between the upper housing plate (102u) and the lower housing plate (102l); a luminal connector (104) configured to connect to the patient line; Equipped with The filter set (100) has a luminal connector (104) connected to the filter housing (102) via at least one of a fresh PD fluid tube (106a) or a used PD fluid tube (106b).

18. 1. A method of manufacturing a filter set (100) for connection to a patient line, the method comprising: forming a plurality of upper and lower housing plates (102u, 102l) by heating at a softening temperature and applying a vacuum; spreading a filter membrane (112) in sheet form between each of the formed upper housing plate (102u) and the formed lower housing plate (102l); heating the upper housing plate (102u) to a sealing temperature and sealing it to the lower housing plate (102l) so as to seal the filter membrane (112) in place; A method comprising:

19. 20. The method of claim 18, wherein spreading the filter membranes includes spreading a filter membrane sheet sized to provide a plurality of filter membranes between the upper housing plate and the lower housing plate during formation, and separating the filter set after heating and sealing the upper housing plate to the lower housing plate.

20. 20. The method of claim 18, further comprising separating the plurality of formed upper housing plates (102u) and formed lower housing plates (102l); drilling at least one opening for at least one hydrophobic membrane (114); and sealing the at least one hydrophobic membrane (114) across the at least one opening before heating the upper housing plate (102u) and sealing it to the lower housing plate (102l).

21. The method of claim 20 , wherein the perforating occurs during the separating.

22. The manufacturing method according to any one of claims 18 to 21, wherein the sealing temperature is higher than the softening temperature.

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