Peritoneal dialysis system having air return patient line filter - 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 set (100) in fluid communication with the patient line (50), the filter set (100) including an air diversion net (112) configured to divert air from the PD fluid passing through the filter set (100), and an air return line (58) positioned to return the air-containing PD fluid to the PD machine (20).

Description

[Technical field]

[0001] (Priority Claim) This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 291,036, 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 fluids during dialysis fluid therapy. [Background technology]

[0003] Due to various causes, a person's renal system may 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 may accumulate in the patient's blood and tissues.

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

[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 dialysis fluid, causing diffusion.

[0006] 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 substitution or replacement fluid to the extracorporeal circuit during treatment. Substitution fluid and fluids accumulated by the patient between treatments are ultrafiltered over the course of HF treatment, providing a convective transport mechanism that is particularly beneficial in removing middle and large molecules.

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

[0008] Most HD, HF, and HDF treatments are performed in centers. There is a trend toward home hemodialysis ("HHD") today. In part, HHD can be performed daily, providing therapeutic benefits over in-center hemodialysis treatments, which are typically performed two or three times a week. Studies have shown that more frequent treatments remove more toxins and waste products and cause less fluid overload between dialysis 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 center 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 overnight or during the day while the patient is relaxing, working, or being productive.

[0009] Another type of renal failure therapy is peritoneal dialysis ("PD"), in which dialysis solution, also called dialysis fluid or PD fluid, is infused into a patient's peritoneal cavity via a catheter. The PD fluid contacts the peritoneal membrane within the patient's peritoneal cavity. Waste, toxins and excess water pass from the patient's bloodstream through capillaries in the peritoneum and enter the PD fluid by diffusion and osmosis (i.e., an osmotic gradient occurs across the membrane). An osmotic agent in the PD fluid provides the osmotic pressure 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, whereby the patient catheter communicates 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 fresh PD fluid bag, allowing the PD fluid to remain in the patient's peritoneal cavity, where waste, toxins, and excess water transfer occurs. After a dwell period, the patient repeats the manual dialysis procedure, for example, four times a day. Manual peritoneal dialysis requires a significant amount of time and effort from the patient, leaving ample room for improvement.

[0011] APD is similar to CAPD in that the dialysis treatment includes drain, fill and dwell cycles. However, APD machines perform the cycles automatically, usually while the patient sleeps. APD machines relieve the patient from having to manually perform the treatment cycles and from having to transport supplements during the day. APD machines fluidly connect to an implanted catheter, a source or bag of fresh PD fluid, and a fluid drain. The APD machine pumps fresh PD fluid from the dialysis fluid source through the catheter and into the patient's peritoneal cavity. APD machines also allow the PD fluid to dwell in the peritoneal cavity and for waste, toxins and excess water to be transported. The source may contain multiple liters of dialysis fluid, including several solution bags.

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

[0013] PD fluids need to be sterile or very close to sterile because they are infused into the patient's peritoneal cavity and are therefore considered drugs. Bagged PD fluids are typically adequately sterilized for treatment, but PD fluids made on-line, or in PD machines or cyclers that employ disinfection, may require additional sterilization.

[0014] Therefore, there is a need for an effective, low-cost method of providing additional sterilization to fresh PD fluid before it is sent 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 machine 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 in conjunction 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 is connected to the patient's transfer set, which is then in fluid communication with the patient's indwelling catheter.

[0016] The PD machine or cycler may include a durable PD fluid pump that pumps the PD fluid through itself without using disposable components, or a disposable type PD fluid pump that includes a pump actuator that operates disposable, fluid-contacting pumping components, such as peristaltic pump tubing or flexible pump chambers. A single PD fluid pump may be used, but it should be understood that dedicated fresh and used PD fluid pumps may alternatively be used. A single PD fluid pump may also include multiple pump chambers for a more continuous PD fluid flow. The PD machine or cycler may similarly include multiple valves that may be flow-through and durable without operating with disposable components, or disposable type valves with valve actuators that operate disposable, fluid-contacting valve components, such as valve seats on tube segments or cassette bases.

[0017] The pumps and valves are under the automatic control of a control unit provided by the machine or cycler. In one 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. The valves further include a supply valve that allows the flow of fresh PD fluid from one or more fresh PD fluid sources, a drain valve that allows the spent PD fluid to be sent to a drain, and an air return valve that allows PD fluid containing air to be returned to the machine or cycler.

[0018] The fresh and spent PD fluid lumens can again be reusable or disposable. If the fresh and spent PD fluid lumens are reusable, they terminate in connectors that connect to the lumen connectors of the filter set, which can be sealed (e.g., ultrasonically sealed, heat sealed, or solvent bonded) to or molded with the body of the filter set. The body is then sealed (e.g., ultrasonically sealed, heat sealed, or solvent bonded) to or molded with the transfer set connector, which connects directly to a mating connector on the patient's transfer set or to a mating connector on a short tube placed between the body and the patient's transfer set. Alternatively, the transfer set connector can simply be a port through which a short tube extends and is welded.

[0019] The body of the filter set includes one or more filter membranes that further filter and sterilize the fresh PD fluid to make it suitable for delivery to the patient's peritoneal cavity. The one or more filter membranes may have any suitable shape, such as a tubular, capillary or flat shape. The filter membranes may be sterilizing grade or sterile hydrophilic membranes and may be formed with porous walls having a pore size of about 0.2 microns through which the fresh PD fluid passes for further filtration.

[0020] Spent PD fluid removed through the patient's transfer set enters the body of the filter set via the transfer set connector and flows through the body, lumen connector, and the spent PD fluid lumen under negative pressure back to the machine or cycler. The machine or cycler pumps the spent PD fluid to a drain under positive pressure. The spent PD fluid may contact the outside of one or more filter membranes, but in a tangential or tangential manner, so that fibrin, proteins, and other particulates in the patient's effluent are less likely to be captured by or lodged on the filter membrane. Thus, the filter membrane remains effective through multiple fills in a treatment before being discarded with the filter set.

[0021] In one embodiment, the fresh PD fluid lumen and the spent PD fluid lumen are formed concentrically, with the fresh PD fluid lumen located outside the spent PD fluid lumen. In an alternative embodiment, the fresh PD fluid lumen and the spent PD fluid lumen are formed side-by-side. A patient line connector may be provided at either end of the concentric or side-by-side lumens of the dual lumen patient line. The patient line connector connects to a lumen-side connector of the filter set. The lumen-side connector is provided with an air diverting net, in one embodiment, located along the fresh PD fluid inlet flow path so as to be upstream of the filter membrane. The air diverting net has mesh openings fine enough to divert air when wetted, but the mesh openings are open enough not to significantly impede the flow of fresh PD fluid.

[0022] The lumen side connector includes multiple ports, e.g., tapered luer type ports, for sealing to mating ports of the patient line connector. The lumen side connector ports include a fresh PD fluid port and a spent PD fluid port. The fresh PD fluid port is provided with openings, such as slots, which may be evenly distributed around the cylindrical fresh PD fluid port. The openings or slots allow a small amount of fresh PD fluid, including air, diverted by the air diverting net in the lumen side connector to be pushed back to the PD machine or cycler via a third or air return line. The lumen side connector may also include an outer port, which partially defines a channel located between an inner wall of the outer port and an outer wall of the fresh PD fluid port. The channel directs the small amount of fresh PD fluid, including air, to a sealed collection area in the patient line connector. The small amount of fresh PD fluid, including air, leaves the sealed area of ​​the patient line connector via the air return port and the flexible air return line to the machine or cycler under negative pressure, e.g., from a PD fluid pump. The air return port and flexible air return line can be small in diameter because the volume of returned PD fluid is small. The flexible air return line is reusable or disposable depending on whether the dual lumen patient line is reusable or disposable. The flexible air return line can be independent or co-extruded with the dual lumen patient line.

[0023] The flexible air return line connects to an internal durable air return line located within the machine or cycler. The internal or durable air return line may extend to a location upstream or downstream of one or more supply valves. If the location is upstream of one or more supply valves, the one or more supply valves may also function as valves to open and close the flow of air return PD fluid. If the location is downstream of one or more supply valves, the air return line may be provided with an air return valve that is selectively opened during patient fill to allow air-entrained PD fluid to be returned upstream of the PD fluid pump. The flow of air return PD fluid may be throughout the entire patient fill or intermittent during the patient fill.

[0024] The PD machine or cycler includes an air trap located between the location where the air return line reconnects to the primary PD fluid line and the PD fluid pump. The air trap provides a volume of relatively stagnant PD fluid that allows air to escape the fluid via buoyancy. Thus, the air trap serves to remove air that is diverted to the PD machine or cycler via the air return mechanism described herein.

[0025] In a first aspect of the present disclosure, which may be combined with any other aspect or portion thereof in light of the disclosure set forth herein and without limiting the present disclosure in any manner, a peritoneal dialysis ("PD") system includes a PD machine, a patient line extending from the PD machine, a filter set in fluid communication with the patient line, the filter set including an air diversion net configured to divert air from the PD fluid passing through the filter set, and an air return line arranged to return the air-containing PD fluid to the PD machine (20).

[0026] In a second aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the air diversion net is further configured to allow fresh PD fluid to pass through the air diversion net.

[0027] In a third aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the filter set further includes at least one filter membrane configured to filter the PD fluid that has passed through the air redirection net.

[0028] In a fourth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the filter set is configured such that the spent PD fluid flows tangentially along at least one filter membrane.

[0029] In a fifth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, a PD machine includes a PD fluid pump, an air return line extends to an air return line of the PD machine, and the air return line of the PD machine extends to an inlet of the PD fluid pump.

[0030] In a sixth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the PD machine includes an air trap, the air return line extends to an air return line of the PD machine, and the air return line of the PD machine is in fluid communication with the air trap.

[0031] In a seventh aspect of the present disclosure that may be combined with any other aspect or portion thereof, the air return line is co-extruded with the patient line.

[0032] In an eighth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the patient line includes a patient line connector for connecting to the lumen side connector of the filter set, and an air return line extends from the patient line connector to the PD machine.

[0033] In a ninth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the lumen side connector includes a fresh PD fluid port for receiving fresh PD fluid from the patient line, and the fresh PD fluid port includes at least one opening for allowing air diverted by the air diversion net to be returned to the PD machine via the air return line.

[0034] In a tenth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, at least one opening is fluidly connected to a channel formed by the lumen side connector, and the channel extends to direct air diverted by the air diversion net to an air return port of the patient line connector.

[0035] In an eleventh aspect of the present disclosure that may be combined with any other aspect or a portion thereof, a patient line connects to the lumen side connector of the filter set, and an air return line extends from the lumen side connector to the PD machine.

[0036] In a twelfth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the patient line is a dual lumen patient line including a lumen for fresh PD fluid and a lumen for used PD fluid, and the air return line is a third line extending between the filter set and the PD machine.

[0037] In a thirteenth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the PD system includes a patient line connector for connecting to the lumen side connector of the filter set, and the lumen of fresh PD fluid and the lumen of used PD fluid are connected to the patient line connector.

[0038] In a fourteenth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the filter set includes a lumen side connector, and the lumen of the fresh PD fluid and the lumen of the spent PD fluid are connected to the lumen side connector.

[0039] In a fifteenth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the filter set is configured to connect directly to a patient transfer set or the filter set includes a flexible tube configured to connect to a patient transfer set.

[0040] In a sixteenth aspect of the present disclosure which may be combined with any other aspect or portion thereof, the filter membrane is a sterilizing grade filter membrane or a sterile filter membrane.

[0041] In a seventeenth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, a filter set includes a body holding at least one filter membrane, the at least one filter membrane being positioned and arranged such that the fresh PD fluid flows through at least one porous wall of the at least one filter membrane before exiting the body, an air diversion net configured to divert air from the fresh PD fluid before it reaches the at least one filter membrane, and a fresh PD fluid port for receiving the fresh PD fluid, the fresh PD fluid port including at least one opening for allowing the air diverted by the air diversion net to be returned to the PD machine.

[0042] In an eighteenth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the filter set includes a channel in fluid communication with at least one opening, the channel extending to direct air diverted by the air diversion net back to the PD machine.

[0043] In a nineteenth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the filter set includes a connector for connecting to a patient line connector, and the air diversion net is provided by the connector.

[0044] In a twentieth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the filter set includes a connector for connecting to a patient line connector, and a port for fresh PD fluid is provided by the connector.

[0045] In a twenty-first aspect of the present disclosure which may be combined with any other aspect or portion thereof, the at least one filter membrane has a tubular shape, a capillary shape or a flat shape.

[0046] In a twenty-second aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the filter set includes (i) a transfer set side connector configured to connect to a patient's transfer set, or (ii) a flexible line configured to connect to a patient's transfer set.

[0047] In a twenty-third aspect of the present disclosure, which may be used in conjunction with any other aspect or portion thereof, any of the features, functions, and alternatives described in association with any one or more of Figures 1 to 4 may be combined with any of the features, functions, and alternatives described in association with any other of Figures 1 to 4.

[0048] In light of the above aspects and discussion herein, it is an advantage of the present disclosure to provide a filter set that operates with a dual lumen patient line.

[0049] 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.

[0050] A further advantage of the present disclosure is to provide a filter set that removes air before it reaches the filter membrane.

[0051] Yet another advantage of the present disclosure is providing a filter set that removes air without the need for a hydrophobic membrane.

[0052] Further features and advantages are described in and will be apparent from the following detailed description and drawings. The features and advantages described herein are not all-inclusive, and in particular many further features and advantages will be apparent to those skilled in the art in view of the drawings and description. Any particular embodiment need not have all of the advantages listed herein, and it is expressly contemplated that each advantageous embodiment may be separately claimed. Furthermore, it should be noted that the language used in this specification has been selected primarily for ease of reading and description purposes, and is not intended to limit the scope of the inventive subject matter. [Brief description of the drawings]

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

[0054] [Diagram 2] FIG. 2 is a cross-sectional perspective view of one embodiment of a lumen side connector of the patient line filter set of the present disclosure.

[0055] [Diagram 3] FIG. 3 is a cross-sectional view of the lumen side connector and mating patient line connector of FIG. 2 of the present disclosure.

[0056] [Figure 4] FIG. 4 is a simplified flow schematic showing various flow paths, including the air return path of the present disclosure. 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 shown. 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 a filter set 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 disposable, in one embodiment, the filter set 100 is integrated into or formed with the disposable patient line 50. In either configuration, the distal end of the filter set 100 is connected to the patient's transfer set 60, which is then in fluid communication with the patient P's indwelling catheter.

[0058] The PD machine or cycler 20 may include a housing 22 that provides a durable PD fluid pump 24, which 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 machine 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 machine or cycler 20 provides a volume control device, such as one or more flow meters (not shown).

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

[0060] The PD machine or cycler 20 also includes a number of valves 26a-26e, which may similarly be flow-through and durable without operating on disposable components, or disposable type valves having 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-26e 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-26e include electromagnetic pinch valves that pinch closed flexible tubing, pneumatic valve actuators that actuate cassette seats, and electromechanical valve actuators that actuate cassette seats.

[0061] The machine or cycler 20 will likely include a number of valves 26a-26n. For ease of illustration, the machine or cycler 20 is shown as having a fresh PD fluid valve 26a that is controlled to open to allow the PD fluid pump 24 to pump fresh PD fluid under positive pressure through a fresh PD fluid lumen 52 for a dual lumen patient line 50 to a patient P. The valves also include a spent PD fluid valve 26b that is controlled to open to allow the PD fluid pump 24 to draw spent PD fluid from the patient P under negative pressure through a spent PD fluid lumen 54 for a dual lumen patient line 50. One or more supply valves 26c are provided that allow a flow of fresh PD fluid from one or more sources of fresh PD fluid to be pumped to the cycler 20 via the PD fluid pump 24. A drain valve 26d is provided that allows the spent PD fluid to be sent to a drain. Air return valve 26 e , described in more detail below, allows PD fluid, including air that has been diverted within filter set 100 , to be returned to the PD machine or cycler 20 .

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

[0063] Pump 24 and valves 26a-26e in the illustrated embodiment are under the automated control of a control unit 40 provided by machine or cycler 20 of system 10, to which pressure sensors 28a, 28b (and other sensors) output. Control unit 40 in the illustrated embodiment includes one or more processors 42, one or more memories 44, and a video controller 46. Control unit 40 receives, stores, and processes signals or outputs from pressure sensors 28a, 28b and other sensors provided by machine or cycler 20, such as one or more temperature sensors 30 and one or more conductivity sensors (not shown). The control unit 40 uses pressure feedback from one or more of the pressure sensors 28a, 28b to control the 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 to 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, for example, an in-line heater to heat 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 machine or cycler 20, and to prepare the machine or cycler for the next treatment. The additional filtration described herein provides a 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 machine 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 alarms, warnings, and / or voice guidance commands. The user interface 48 may be provided with the machine or cycler 20 as shown 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 described above, the fresh PD fluid lumen 52 and the spent PD fluid lumen 54 for the dual lumen patient line 50 may again be reusable or disposable. If the dual lumen patient line 50 is reusable, the lumens terminate in connectors 56 that connect to lumen connectors 104 of the filter set 100, which may be sealed (e.g., ultrasonically sealed, heat sealed, or solvent bonded) to or molded with the filter set body 106. A third or air return line 58, described in more detail below, returns the air-laden PD fluid from the filter set 100 to the PD machine or cycler 20. The body 106 is then sealed (e.g., ultrasonically sealed, heat sealed, or solvent bonded) or molded with the transferset connector 108, which connects directly to a mating connector on the patient's transferset 60 or to a mating connector on a short length of flexible tubing 110 disposed between the transferset connector 108 and the patient's transferset 60. The body 106, lumen connector 104, and transferset connector 108 may be made of 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").

[0067] FIG. 2 details one embodiment of the lumen side connector 104. The illustrated version of the lumen side connector 104 is for a concentric lumen 52 and lumen 54 relationship for a dual lumen patient line 50. However, it should be understood that the teachings associated with FIG. 2 are equally applicable to a side-by-side relationship of the lumen 52 and lumen 54 for a dual lumen patient line 50. The lumen side connector 104 is provided with an air diversion net 112 located along the fresh PD fluid inlet flow path, such that it is upstream (from the perspective of the fresh PD fluid) of the filter membrane 114 in both the concentric and side-by-side embodiments. The air diversion net 112 has mesh openings fine enough to divert air when wetted, but the mesh openings are open enough not to significantly impede the flow of fresh PD fluid. The air diversion net 112 may be made of, for example, a medically safe metal or hydrophobic polymer, and may have a pore size ranging from about 0.1 mm to about 0.3 mm. The air diversion net 112 may be sealed to the lumen side connector 104 by ultrasound, heat and / or adhesive. The filter membrane 114 may be a sterilizing grade or sterile hydrophilic membrane, which may be formed with porous walls having a pore size of about 0.2 microns through which the fresh PD fluid passes for further filtration. The filter membrane 114 may be made, for example, from polysulfone or polyethersulfone mixed with polyvinylpyrrolidone. The filter membrane 114 in the illustrated embodiment has a capillary shape, but may alternatively have a tubular or flat shape.

[0068] The lumen side connector 104 shown in FIG. 2 includes multiple ports, e.g., tapered luer type ports, for sealing to mating ports of the patient line connector 56. The lumen side connector ports include a fresh PD fluid port 104a and a spent PD fluid port 104b, each of which may be a cylindrical port concentric with one another. Spent PD fluid removed through the patient transfer set 60 enters the filter set body 106 via the transfer set side connector 108, flows under negative pressure through the body 106, the spent PD fluid port 104b of the lumen side connector as shown in FIG. 2, and the spent PD fluid lumen 54, and returns to the PD machine or cycler 20. The PD machine or cycler 20 pumps the spent PD fluid under positive pressure to drain via drain line 62. While the spent PD fluid may contact the outside of one or more of the filter membranes 114, it may do so in a tangential or non-tangential manner, such that fibrin, proteins and other particulates in the patient's effluent are less likely to be captured by or lodged on the filter membranes, and thus the filter membranes 114 remain effective through multiple fills in a treatment before being discarded along with the filter set 100.

[0069] The fresh PD fluid port 104a is provided with openings 104o, such as slots, which may be evenly (e.g., evenly radially) distributed around the cylindrical fresh PD fluid port. In the illustrated example, there are four slots 104o evenly spaced 90° apart from each other. Alternatively, the openings 104o may be, for example, a series of holes, a row of holes, a rectangular shape. The openings or slots 104o allow a small amount of fresh PD fluid, including air (shown as air bubbles in FIG. 2) diverted by the air diverting net 112 in the lumen side connector 104, to be pushed back into the PD machine or cycler 20 via the third or air return line 58.

[0070] The lumen connector 104 in the illustrated embodiment also includes an outer cylindrical port 104c that partially defines a cylindrical channel 104d located between an inner wall of the cylindrical outer port 104c and an outer wall of the cylindrical fresh PD fluid port 104a. In one embodiment, each of the ports 104a-104c are molded with the remainder of the lumen connector 104.

[0071] 3 illustrates one possible mating arrangement between the lumen side connector 104 and the patient line connector 56, which may be similarly molded and made of any of the materials described herein. The mating arrangement of FIG. 3 is specific to the concentric relationship between lumen 52 and lumen 54. The mating arrangement between the lumen side connector 104 and the patient line connector 56 is different due to the side-by-side relationship for lumen 52 and lumen 54, but still includes a third or air return line 58 as described herein. In the illustrated embodiment, the patient line connector 56 includes a cylindrical fresh PD fluid port 56a that is radially sized such that its outer surface seals against the inner surface of the cylindrical fresh PD fluid port 104a via a gasket, such as, for example, silicone or other suitable rubber. The length of fresh PD fluid port 56a is sized short enough to allow at least a portion of opening or slot 104o of fresh PD fluid port 104a to be exposed to the flowing fresh PD fluid, whereby air is carried away through the exposed portion of opening or slot 104o.

[0072] The patient line connector 56 also includes a cylindrical spent PD fluid port 56b, the inner surface of which is radially sized to seal against the outer surface of the cylindrical spent PD fluid port 104b via a gasket, such as silicone or other suitable rubber. The patient line connector 56 further includes a cylindrical outer wall 56c, the inner surface of which is radially sized to seal against the outer surface of the cylindrical outer cylindrical port 104c via a gasket, such as silicone or other suitable rubber. The cylindrical outer wall 56c in the illustrated embodiment includes outwardly facing threads configured to mate with and releasably threadably engage the inwardly facing threads of the outer wall 104e of the lumen side connector 104. Threading the lumen side connector 104 into the patient line connector 56 creates each of the three seals described above in one embodiment.

[0073] FIG. 3 shows the fresh PD fluid lumen 52 for the dual lumen patient line 50, which is sealed (e.g., ultrasonically, heat and / or adhesively sealed) to the fresh PD fluid port 56a of the patient line connector 56. The spent PD fluid lumen 54 is sealed in any desired manner to the spent PD fluid port 56b. The third or air return line 58 is sealed in any desired manner to the air return port 56d of the patient line connector 56. When the lumen side connector 104 is mated to the patient line connector 56 during patient fill, the channel 104d directs a small amount of fresh PD fluid, including air, to a sealed collection area 56e located within the patient line connector 56. The small amount of fresh PD fluid, including air, exits the sealed area 56e, for example, under negative pressure from the PD fluid pump 24, via the air return port 56d and the flexible air return line 58, to the PD machine or cycler 20. The air return port 56d and the flexible air return line 58 can be small in diameter because the amount of PD fluid returned is small. The flexible air return line 58 is either reusable or disposable depending on whether the dual lumen patient line 50 is reusable or disposable. The flexible air return line 58 can be separate or co-extruded with the dual lumen patient line 50.

[0074] FIG. 1 shows that the flexible air return line 58 connects to an internal durable air return line 34 located within the PD machine or cycler 20. The internal or durable air return line 34 may extend to a location upstream or downstream of one or more supply valves 26c. If the location is upstream of one or more supply valves 26c, the one or more supply valves may also function as valves to open and close the flow of air return PD fluid through lines 58 and 34. If the location is downstream of one or more supply valves 26c, the cycler air return line 34 may be provided with an air return valve 26e that is selectively opened during patient fill to allow air-entrained PD fluid to be returned upstream of the PD fluid pump 24. The flow of air return PD fluid through lines 58 and 34 may occur throughout the entire patient fill or may occur intermittently via the opening and closing of valve 26e during the patient fill.

[0075] The PD machine or cycler 20 includes an air trap 36 that is located between the location where the air return line reconnects to the primary PD fluid line 38 and the PD fluid pump 24. The air trap 36 provides a volume of relatively stagnant PD fluid that allows air to escape the fluid via buoyancy. Thus, the air trap 36 serves to remove air that is diverted into the PD machine or cycler 20 via the air return mechanisms described herein.

[0076] 4 shows a simplified flow schematic summarizing the air return flow of the system 10 of the present disclosure. Fresh PD fluid pumped by the PD fluid pump 24 flows along the primary PD fluid line 38 and the fresh PD fluid lumen 52 to the filter set 100. An air diversion net 112 in the filter set 100 diverts the air in the fresh PD fluid while one or more sterile grade or sterile filter membranes 114 further filter the fresh PD fluid which is sent to the patient P via a short flexible tube 110 (if provided) and the patient transfer set 60. Spent PD fluid is removed from the patient P via the PD fluid pump 24 and sent to the drain via the patient transfer set 60, the short flexible tube 110 (if provided), the filter set 100, the spent PD fluid lumen 54, and the drain line 62. The air and small amount of PD fluid diverted through the air diversion net 112 is returned to the PD fluid pump 24 via the flexible air return line 58, the cycler air return line 34 and the primary PD fluid line 38. Along the way, air is degassed from the PD fluid through the air trap 36.

[0077] 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. It is therefore intended that any or all of such changes and modifications may be covered by the appended claims. For example, in the concentric embodiment for the dual lumen patient line 50, the lumen 52 of fresh PD fluid is shown as being located outside the lumen 54 of spent PD fluid, but instead, the lumen 54 of spent PD fluid may be located outside the lumen 52 of fresh PD fluid. In another example, the air return mechanism of the present disclosure is used with a single lumen patient line, i.e., a dual lumen patient line is not required for the air return mechanism of the present disclosure. In a further example, if the dual lumen patient line 50 is disposable, the patient line connector 56 may be eliminated, the spent PD fluid lumen 54 is instead welded to the spent PD fluid port 104b of the lumen side connector 104, the fresh PD fluid lumen 52 is instead welded to the fresh PD fluid port 104a, and the flexible air return line 58 is instead welded to an additional fluid port that is in fluid communication with the cylindrical air / PD fluid return channel 104d.

Claims

1. A peritoneal dialysis ("PD") system (10), comprising: A PD machine (20), a patient line (50) extending from the PD machine (20); a filter set (100) in fluid communication with the patient line (50), the filter set (100) including an air diverting net (112) configured to divert air from the PD fluid passing through the filter set (100); an air return line (58) positioned to return air-laden PD fluid to the PD machine (20); A PD system (10) comprising:

2. The PD system (10) of claim 1, wherein the air diversion net (112) is further configured to allow fresh PD fluid to pass through the air diversion net (112).

3. The PD system (10) of claim 2, wherein the filter set (100) further comprises at least one filter membrane (114) configured to filter the PD fluid that has passed through the air diversion net.

4. The PD system (10) of claim 3, wherein the filter set (100) is configured to allow spent PD fluid to flow tangentially along the at least one filter membrane (114).

5. 5. The PD system (10) of claim 3 or 4, wherein the at least one filter membrane (114) is a sterilizing grade filter membrane or a sterile filter membrane.

6. 5. The PD system of claim 1, wherein the PD machine includes a PD fluid pump, the air return line extends to an air return line of the PD machine, and the PD machine air return line extends to an inlet of the PD fluid pump.

7. 5. The PD system (10) of claim 1, wherein the PD machine (20) includes an air trap (36), the air return line (58) extends to an air return line (34) of the PD machine (20), and the PD machine air return line (34) is in fluid communication with the air trap (36).

8. The PD system (10) of any one of claims 1 to 4, wherein the air return line (58) is co-extruded with the patient line (50).

9. The PD system (10) of any one of claims 1 to 4, wherein the patient line (50) includes a patient line connector (56) for connection to the lumen-side connector (104) of the filter set (100), and the air return line (58) extends from the patient line connector (56) to the PD machine (20).

10. 10. The PD system (10) of claim 9, wherein the lumen-side connector (104) includes a fresh PD fluid port (104a) for receiving fresh PD fluid from the patient line (50), and the fresh PD fluid port (104a) includes at least one opening (104o) for allowing air diverted by the air diverting net (112) to be returned to the PD machine (20) via the air return line (58).

11. 11. The PD system (10) of claim 10, wherein the at least one opening (104o) is fluidly connected to a channel (104d) formed by the lumen side connector (104), the channel extending to direct air diverted by the air diverting net (112) to an air return port (56d) of the patient line connector (56).

12. The PD system (10) of any one of claims 1 to 4, wherein the patient line (50) connects to a lumen-side connector (104) of the filter set (100), and the air return line (58) extends from the lumen-side connector (104) to the PD machine (20).

13. 5. The PD system (10) of claim 1, wherein the patient line (50) is a dual lumen patient line including a lumen (52) for fresh PD fluid and a lumen (54) for spent PD fluid, and the air return line (58) is a third line extending between the filter set (100) and the PD machine (20).

14. 14. The PD system (10) of claim 13, further comprising a patient line connector (56) for connecting to the lumen side connector (104) of the filter set (100), wherein the fresh PD fluid lumen and the used PD fluid lumen (52, 54) are connected to the patient line connector (56).

15. 14. The PD system (10) of claim 13, wherein the filter set (100) includes a lumen-side connector (104), and the fresh PD fluid lumen and the used PD fluid lumen (52, 54) are connected to the lumen-side connector (104).

16. 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's transfer set, or the filter set (100) includes flexible tubing (110) configured to connect to the patient's transfer set.

17. A filter set (100), comprising: a body (106) carrying at least one filter membrane (114), the at least one filter membrane (114) positioned and arranged such that fresh PD fluid flows through at least one porous wall of the at least one filter membrane (114) before exiting the body (106); an air diversion net (112) configured to divert air from the fresh PD fluid before it reaches the at least one filter membrane (114); a fresh PD fluid port (104a) for receiving said fresh PD fluid; Including, The fresh PD fluid port (104a) includes at least one opening (104o) for allowing air diverted by the air diverting net (112) to be returned to the PD machine.

18. 18. The filter set (100) of claim 17, including a channel (104d) in fluid communication with the at least one opening (104o), the channel (104d) extending to direct air diverted by the air diverting net (112) for return to the PD machine.

19. 19. The filter set (100) of claim 17 or 18, including a connector (104) for connection to a patient line connector, the air diverting net (112) being provided by the connector (104).

20. 19. The filter set (100) of claim 17 or 18, comprising a connector (104) for connection to a patient line connector, the fresh PD fluid port (104a) being provided by the connector (104).

21. 19. The filter set (100) of claim 17 or 18, wherein the at least one filter membrane (114) has a tubular shape, a capillary shape, or a flat shape.

22. 19. The filter set (100) of claim 17 or 18, comprising: (i) a transferset connector (108) configured to connect to a patient's transferset; or (ii) a flexible line (110) configured to connect to the patient's transferset.

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