Peritoneal dialysis system having a 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), and a filter set (100) in fluid communication with the patient line (50), the filter set (100) including a filter membrane (120, such as a sterilizing grade filter membrane or a bacterial reduction filter membrane) positioned and arranged such that fresh PD fluid flows through the filter membrane (120) into a filtered fluid compartment (106f), the filtered fluid compartment (106f) including an outlet (106o) to a port (106p), the port (106p) in fluid communication with a spent PD fluid channel (106u) positioned and arranged to transport spent PD fluid around the filter membrane (120) without contacting the filter membrane (120). Methods for priming the filter set (100) are also disclosed.

Description

[Technical field]

[0001] (Priority Claim) This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 291,043, 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 otherwise 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 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 to provide a convective transport mechanism that is particularly beneficial for removing middle and large molecules.

[0007] Hemodiafiltration ("HDF") is a therapy that combines convective and diffusive clearance. HDF uses dialysis fluid flowing through a dialyzer, similar to standard hemodialysis, 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 because 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 experience less interdialytic fluid overload 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 regions, 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 may be performed overnight or during the day while the patient relaxes, works, or is otherwise 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 the patient's peritoneal cavity via a catheter. The PD fluid contacts the peritoneal membrane in the patient's peritoneal chamber. Waste, toxins and excess water pass from the patient's bloodstream through capillaries in the peritoneal membrane 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 gradient. Spent PD fluid is pumped out of the patient to remove 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 to allow 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 to infuse fresh PD fluid into the patient through the catheter. 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 chamber. APD machines also allow the PD fluid to dwell in the chamber and for waste, toxins and excess water to be transported. The source may contain multiple liters of dialysis fluid, including several solution bags.

[0012] APD machines pump and drain spent PD fluid from the patient's peritoneal cavity through a catheter. As with the manual process, several drain, fill and dwell cycles occur during dialysis. A "last fill" may occur at the end of an APD treatment. The last 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 fluids need to be sterile or very close to sterile because they are injected into the patient's peritoneal cavity and are therefore considered drugs. Bagged PD fluids are generally adequately sterilized for treatment, but PD fluids made on-line, or PD machines or cyclers that use 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 merged into the disposable patient line. In either configuration, the distal end of the filter set may be connected to a patient transfer set that is 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 the pump itself without the use of disposable components, or 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 pumping chamber. The PD machine or cycler similarly includes a plurality of valves that may be flow-through and durable without 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.

[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. Although a single PD fluid pump may be used, it should be understood that dedicated fresh and spent PD fluid pumps may alternatively be used. The single PD fluid pump may also include multiple pumping chambers for a more continuous flow of PD fluid.

[0018] The fresh and spent PD fluid lumens may again be reusable or disposable. If the fresh and spent PD fluid lumens are reusable, the lumens terminate in connectors that connect to the lumen connectors of the filter set, which may be sealed (e.g., ultrasonically sealed, heat sealed, or solvent bonded) to the body of the filter set or molded with the body of the filter set. The body is then sealed (e.g., ultrasonically sealed, heat sealed, or solvent bonded) to the transfer set connector 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 disposed between the body and the patient's transfer set. Alternatively, the transfer set connector may be located at the end of a short tube extending from the body. Here, the body includes a transfer set port (e.g., molded with a transfer set port) and the short tube extends into or over the transfer set port for welding to the port. The body, lumen side connector, and transferset side connector or port may be referred to herein as the filter housing.

[0019] The lumen connector and the body form a fresh PD fluid passageway and a spent PD fluid passageway. The fresh PD fluid passageway extends through a fresh PD fluid port in the lumen connector toward an inner wall located in the body of the filter housing. The inner wall redirects the fresh PD fluid over the wall and into a pressurized compartment that resides above and outside the flat sheet filter membrane. The fresh PD fluid is pressurized in the pressurized compartment. The pressurization forces the fresh PD fluid through the pores of the flat sheet filter membrane and into the filtered fluid compartment of the body, which is primarily bounded by the inner surface of the flat sheet filter membrane and the bottom surface of the body. In one embodiment, a series of ribs extend upward from the bottom surface of the body. The series of ribs support the flat sheet filter membrane under both positive patient fill pressure and negative patient drain pressure. However, the ribs are spaced apart to allow fresh filtered PD fluid to flow through the ribs.

[0020] In one embodiment, the inner wall that pushes fresh PD up the filter membrane extends all the way around the series of ribs. The continuous inner wall is located inside the continuous outer wall of the body. Thus, a circumferential spent PD fluid channel is formed between the continuous inner wall and the continuous outer wall. The circumferential spent PD fluid channel allows spent PD fluid to flow from the patient back around the series of ribs and out of the body with little or no contact with the filter membrane.

[0021] The filter membrane may be a sterilizing grade or bacteria reducing hydrophilic flat sheet membrane with a pore size of about 0.2 microns through which the fresh PD fluid flows for further filtration. The flat sheet filter membrane, in one embodiment, is sized to provide the necessary filtration required over multiple patient fills of PD therapy before being discarded.

[0022] In one embodiment, fresh additional filtered PD fluid flows from the filtered fluid compartment of the body through an outlet, e.g., a hole or opening, provided in an end of the continuous inner wall opposite the fresh PD fluid inlet end of the continuous inner wall. The filtered fresh PD fluid flows through the outlet into the transferset side port, through the transferset side port, through the short tube of the filter set (if provided), through the patient's transferset, and into the patient's peritoneal cavity. In one embodiment, the short tube extends over the transferset side port and is ultrasonically sealed, heat sealed, or solvent bonded to the transferset side port.

[0023] The short tube and the transfer set side port also receive spent PD fluid from the patient after the patient's residence. The spent PD fluid flows from the transfer set side port to the circumferential spent PD fluid channel. As previously described, the circumferential spent PD fluid channel allows the spent PD fluid to be drawn through the body of the filter housing without contacting and potentially clogging the filter membrane. The circumferential spent PD fluid channel provides an unobstructed path for the spent PD fluid, which also helps to mitigate pressure loss through the filter set. Although it is fluidically possible for the spent PD fluid to flow through an outlet provided in the continuous inner wall into the body's filtered fluid compartment, negative pressure is applied only from within the circumferential spent PD fluid channel, and therefore there is little incentive for the spent PD fluid to flow into the filtered fluid compartment. Similarly, while it is fluidly possible for fresh PD fluid to flow into the spent PD fluid channels surrounding the circular periphery, the change in direction required for the fresh PD fluid to do so would make such a path more tortuous than simply flowing through a transfer set side port to the patient. Furthermore, the spent PD fluid channels and spent PD fluid lumens surrounding the dual lumen patient tube will likely fill with PD fluid during patient fill, and because the spent PD fluid lumens are closed in the PD machine or cycler, there is little or no room for fresh PD fluid to enter the spent PD fluid channels surrounding the periphery.

[0024] The spent PD fluid removed through the patient transfer set passes under negative pressure through the filter set via the circumferential spent PD fluid channel (thus bypassing the filter membrane) and through the spent PD fluid lumen of the dual lumen patient line back to the machine or cycler. The machine or cycler pumps and drains the spent PD fluid under positive pressure. The cycler includes a pressure sensor located along the spent PD fluid side of its internal tubing, which measures the negative pressure applied to the spent PD fluid by the PD fluid pump during patient drain. The same pressure sensor can be used to measure the positive pumping pressure during patient fill, which can be returned to the pressure sensor through the spent PD fluid channel that surrounds the periphery of the filter set and the spent PD fluid lumen of the patient line. Measuring the positive pumping pressure using a spent PD fluid side pressure sensor is desirable because the measured pressure is the pressure of the fresh PD fluid downstream (after filtration) of the filter membrane. Thus, the measured pressure takes into account any pressure drop across the filter membrane, which may more accurately reflect the pressure at which the PD fluid is being delivered to the patient.

[0025] As previously described, a series of ribs disposed within the filtered fluid compartment of the body supports the flat sheet filter membrane under both (i) positive pressure from above and (ii) positive pressure from below when the surrounding spent PD fluid channel is under negative pressure (which can be transferred to the filtered fluid compartment via an outlet (hole or opening) provided in the continuous inner wall). The series of ribs allows the filter membrane (e.g., flat sheet) to be as large as necessary to provide the desired filtration capacity. In one embodiment, the series of ribs are co-molded with the bottom surface of the body, the continuous inner wall, the continuous outer wall, the lumen side connector, and the transfer set side connector. In one embodiment, the flat sheet filter membrane is sealed in place via ultrasonic sealing, heat sealing, or solvent bonding to the continuous inner wall and does not cover the surrounding spent PD fluid channel.

[0026] The pressurized compartment and the circumferentially surrounding spent PD fluid channel of the filter housing body are enclosed by a lid, which may be formed from the same material as the remainder of the body. In this embodiment, the lid forms the outside of the pressurized compartment into which fresh PD fluid flows before passing through the filter membrane. The lid is ultrasonically sealed, heat sealed, or solvent bonded to the continuous inner and outer walls of the body to fluidically isolate the circumferentially surrounding spent PD fluid channel from the pressurized compartment. A tongue and groove fit is provided between the lid and one or both of the continuous inner and / or outer walls for sealing.

[0027] The lid may be formed with one or more vent holes. Each vent hole is covered on the inside of the lid with a hydrophobic membrane, which may be ultrasonically sealed, heat sealed, or solvent bonded to the inside surface of the lid around at least one vent opening. The one or more vent holes and hydrophobic membrane allow air to be vented to the atmosphere when fresh PD fluid is pressurized in the pressurized compartment of the body before being filtered through the hydrophilic membrane, which may improve the performance of the membrane in addition to removing air from the filter set. In one embodiment, the lid is provided with one or more protective protrusions disposed adjacent to the one or more vent holes. The one or more protective protrusions serve to prevent the one or more vent holes from being covered by the patient, blanket, etc. while the patient is sleeping during PD therapy.

[0028] A gasket, such as a silicone or polyvinyl chloride ("PVC") rubber gasket, may be fitted over and / or into the fresh and used PD fluid ports of the lumen-side connector of the filter housing. The patient line connector may then include fresh and used ports that extend into the fresh and used PD fluid ports of the lumen-side connector. The gasket provides a port seal between the mated fresh and used PD fluid ports of the patient line connector and the lumen-side connector.

[0029] In a first aspect of the present disclosure, which in light of the disclosure set forth herein is in no way limiting to the present disclosure but which may be combined with any other aspect or portion thereof, a peritoneal dialysis ("PD") system includes a PD machine, a patient line extending from the PD machine, and a filter set in fluid communication with the patient line, the filter set including a filter membrane, the filter membrane positioned and arranged such that fresh PD fluid flows through the filter membrane to a filtered fluid compartment, the filtered fluid compartment including an outlet to a port, the port in fluid communication with a circumferentially surrounding spent PD fluid channel, the circumferentially surrounding spent PD fluid channel positioned and arranged to transport the spent PD fluid around the filter membrane without contacting or limiting contact with the filter membrane.

[0030] In a second 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 fresh PD fluid lumen and a spent PD fluid lumen, the spent PD fluid lumen being placed in fluid communication with a surrounding spent PD fluid channel.

[0031] In a third aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the filter set includes a fresh PD fluid port for fluid communication with the fresh PD fluid lumen and a spent PD fluid port for fluid communication with the spent PD fluid lumen.

[0032] In a fourth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the circumferential spent PD fluid channel is in fluid communication with the spent PD fluid port.

[0033] In a fifth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the port extends to a circumferentially used PD fluid channel.

[0034] In a sixth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the circumferential spent PD fluid channel is located between a continuous inner wall and a continuous outer wall.

[0035] In a seventh aspect of the present disclosure that may be combined with any other aspect or portion thereof, the filter set includes a lid sealed to at least one of the continuous inner wall and the continuous outer wall.

[0036] In an eighth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the lid includes at least one vent opening and at least one hydrophobic membrane sealingly covering the at least one vent opening.

[0037] In a ninth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the continuous inner wall is positioned and arranged to deflect incoming fresh PD fluid above the filter membrane.

[0038] In a tenth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the PD system includes at least one rib located in the filtered fluid compartment to support the filter membrane.

[0039] In an eleventh aspect of the present disclosure that may be combined with any other aspect or portion thereof, the filter membrane is a flat sheet filter membrane, and the filter set includes a pressurized compartment located on an opposite side of the flat sheet filter membrane from the filtered fluid compartment.

[0040] In a twelfth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the filter set includes a fresh PD fluid port positioned and arranged to introduce fresh PD fluid into the pressurized compartment.

[0041] In a thirteenth aspect of the present disclosure that 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.

[0042] In a fourteenth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the PD machine includes a pressure sensor positioned and arranged to sense the pressure of fresh PD fluid downstream of the filter membrane during patient fill.

[0043] In a fifteenth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the PD machine is configured to close a spent PD fluid valve during patient fill and force filtered fresh PD fluid to flow to the port rather than along the surrounding spent PD fluid channel.

[0044] In a sixteenth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the PD machine is configured to close the fresh PD fluid valve during patient drain and force the spent PD fluid to flow along the surrounding spent PD fluid channel rather than within the filtered fluid compartment.

[0045] In a seventeenth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the filter membrane is a sterilizing grade filter membrane or a bacteria reducing filter membrane.

[0046] In an eighteenth aspect of the present disclosure that may be combined with any other aspect or portion thereof, a filter set includes a filtered fluid compartment including an outlet, a filter membrane positioned and arranged such that fresh PD fluid flows through the filter membrane into the filtered fluid compartment, and a circumferential spent PD fluid channel in fluid communication with the outlet, the circumferential spent PD fluid channel positioned and arranged to transport the spent PD fluid around the filter membrane without contacting or limiting contact with the filter membrane.

[0047] In a nineteenth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the filter set includes a port, the outlet is in fluid communication with the port, and the surrounding used PD fluid channel is in fluid communication with the port.

[0048] In a twentieth aspect of the present disclosure that may be combined with any other aspect or portion thereof, there is provided a method of priming a filter set connected to a dual lumen patient line, where during treatment, tubing is located between the filter set and a patient's transfer set, the method including: (i) directing fresh peritoneal dialysis ("PD") fluid to the filter set through a fresh PD fluid lumen of the dual lumen patient line; (ii) forcing the fresh PD fluid through at least one filter membrane of the filter set such that the fresh PD fluid displaces air towards the spent PD fluid lumen of the dual lumen patient line; and drawing spent PD fluid from the patient, through the patient's transfer set, via the tubing, through the spent PD fluid portion of the filter set and into the spent PD fluid lumen of the dual lumen patient line.

[0049] In a twenty-first aspect of the present disclosure that may be combined with any other aspect or portion thereof, withdrawal of spent PD fluid is provided as part of the initial patient drain.

[0050] In a twenty-second aspect of the present disclosure, which may be combined with any other aspect or portion thereof, between forcing fresh PD fluid through the filter membrane and drawing spent PD fluid from the patient, the patient is prompted to connect a tube to the patient's transfer set.

[0051] In a twenty-third aspect of the present disclosure, which may be combined with any other aspect or portion thereof, between pushing fresh PD fluid through the filter membrane and drawing spent PD fluid from the patient, the patient is prompted to open a clamp on the patient's transfer set.

[0052] In a twenty-fourth aspect of the present disclosure that may be combined with any other aspect or portion thereof, air is primed through at least one vent opening of the filter set while sending fresh PD fluid through the fresh PD fluid lumen of the dual lumen patient line.

[0053] In a twenty-fifth aspect of the present disclosure that may be combined with any other aspect or portion thereof, while pumping fresh PD fluid through the fresh PD fluid lumen of the dual lumen patient line, the fresh PD fluid valve is opened and the used PD fluid valve is closed.

[0054] In a twenty-sixth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the spent PD fluid valve is open while forcing fresh PD fluid through the filter membranes of the filter set.

[0055] In a twenty-seventh aspect of the present disclosure that may be combined with any other aspect or portion thereof, the spent PD fluid valve is open while drawing spent PD fluid from the patient.

[0056] In a twenty-eighth aspect of the present disclosure that may be combined with any other aspect or portion thereof, a method includes accumulating known volumetric pump strokes to control the amount of fresh PD fluid pumped to force through a filter membrane.

[0057] In a twenty-ninth aspect of the present disclosure, which may be combined with any other aspect or portion thereof, the method includes sensing a pressure increase from (i) sending fresh PD fluid through a fresh PD fluid lumen of a dual lumen patient line to a filter set to (ii) forcing the fresh PD fluid through a filter membrane.

[0058] In a thirtieth aspect of the present disclosure that may be combined with any other aspect or portion thereof, the spent PD fluid portion of the filter set includes a circumferentially surrounding spent PD fluid channel.

[0059] In a thirty-first aspect of the present disclosure that may be combined with any other aspect or portion thereof, the spent PD fluid drawn from the patient is residual effluent from a previous treatment that is left for the purpose of priming the tubing.

[0060] In a thirty-second aspect of the present disclosure that may be combined with any other aspect or portion thereof, the amount of residual effluent is at least 50 ml.

[0061] In a thirty-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 8 may be combined with any of the features, functions, and alternatives described in association with any other of Figures 1 to 8.

[0062] In light of the above aspects and the description herein, it is an advantage of the present disclosure to provide a filter set that operates in such a dual lumen patient line.

[0063] Another advantage of the present disclosure is to provide a filter set that filters fresh PD fluid and allows spent PD fluid to pass through without contacting the filter membrane (or with minimal contact with the filter membrane).

[0064] A further advantage of the present disclosure is providing a filter set having a spent PD fluid channel through which spent PD fluid can be transported reliably and unobstructed through the filter set.

[0065] Yet another advantage of the present disclosure is to provide a filter set that evacuates air from fresh PD fluid before the fluid is filtered by the filter membrane.

[0066] 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. Also, any particular embodiment need not have all the advantages listed herein, and it is expressly contemplated to separately claim each advantageous embodiment. 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 subject matter of the present invention. [Brief description of the drawings]

[0067] [Figure 1] FIG. 1 is a schematic diagram of one embodiment of a peritoneal dialysis system having a filter set of the present disclosure.

[0068] [Diagram 2] FIG. 2 is a perspective view of one embodiment of a filter housing of the filter set of the present disclosure;

[0069] [Diagram 3] FIG. 13 is a top view of one embodiment of the body of the filter housing of the filter set of the present disclosure, with the housing lid removed to show the fresh and spent PD fluid paths.

[0070] [Figure 4] FIG. 1 is a cross-sectional perspective view highlighting the flow of fresh PD fluid through a filter membrane (partially removed) supported by a series of filter membrane support ribs and a transfer set side connector that distributes filtered fresh PD fluid to the patient.

[0071] [Diagram 5] FIG. 13 is a cross-sectional perspective view of one embodiment of a filter housing of a filter set of the present disclosure highlighting the circumferential spent PD fluid channel that returns spent PD fluid from the patient.

[0072] [Figure 6] FIG. 13 is a cross-sectional perspective view of an alternative dual lumen, lumen side connector of the filter housing of the present disclosure.

[0073] [Figure 7] FIG. 13 is a top perspective view of one embodiment of a lid that is sealed to the body of the filter housing of the filter set of the present disclosure.

[0074] [Figure 8] 8 is a cross-sectional front view of the lid shown in FIG. 7 along the line VIII-VIII. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0075] 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 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 (e.g., via a short flexible tubing 108) to a patient's transfer set 58, which is in turn in fluid communication with the patient P's indwelling catheter.

[0076] The PD machine or cycler 20 may include a housing 22 that includes a durable PD fluid pump 24 that pumps the PD fluid through the pump itself without the use of disposable parts. 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 accurate 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 be less accurate, whereby the machine or cycler 20 provides a volume control device, such as one or more flow meters (not shown).

[0077] Alternatively, pump 24 may be a disposable type PD fluid pump that includes a pump actuator that actuates disposable fluid-contacting pumping components such as peristaltic pump tubing or flexible pumping 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 dedicated fresh and used PD fluid pumps may alternatively be used. A single PD fluid pump 24 may also include multiple pumping chambers for a more continuous PD fluid flow.

[0078] The PD machine or cycler 20 also includes a number of valves 26a, 26b, 26m, 26n, which may similarly be flow-through and durable without operating with disposable components, or may be disposable type valves with valve actuators that actuate disposable fluid-contacting valve components, such as valve seats on tube segments or cassette bases. 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.

[0079] 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 the fresh PD fluid lumen 52 of the dual lumen patient line 50 to the 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 through the spent PD fluid lumen 54 of the dual lumen patient line 50 under negative pressure. The valves further include one or more supply valves 26m that are controlled to open to allow fresh PD fluid to be drawn from one or more fresh PD fluid sources 12 via one or more solution lines 14. The valves further include a drain valve 26n that is controlled to open to allow the spent PD fluid to be sent to a house drain or drain container 16 via a drain line 18.

[0080] The machine 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 26. 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 pressure of the fresh PD fluid upstream of a filter membrane 120 described herein during patient fill. Pressure sensor 28b is, perhaps more importantly, positioned to sense the pressure of the fresh PD fluid downstream (post-filtration) of filter membrane 120 (FIG. 4) during patient fill. Thus, the pressure measured via pressure sensor 28b takes into account any pressure drop across the filter membrane 120 (FIG. 4), which may more accurately reflect the pressure at which fresh PD fluid is being delivered to the patient P.

[0081] Pump 24 and valves 26a-26n 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 can use 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 the positive pressure to the patient's peritoneal cavity and within −.10 bar (−1.5 psig) of the negative pressure from the patient's peritoneal cavity).

[0082] Control unit 40 uses temperature feedback from one or more temperature sensors 30 to control heater 32, such as an in-line heater, to heat fresh PD fluid to a desired temperature (e.g., body temperature or 37° C.). In one embodiment, heater 32 is further used to heat a disinfectant fluid, such as fresh PD fluid, to prepare the device or cycler for the next treatment by disinfecting PD fluid pump 24, valves 26a through 26n, heater 32, and all reusable fluid lines within device or cycler 20. Additional filtration as discussed herein provides a layer of protection in addition to heated fluid disinfection to ensure that the fresh PD fluid is safe for delivery to patient P.

[0083] The video controller 46 of the control unit 40 interfaces with a user interface 48 of the machine or cycler 20, which may include a display screen that operates in conjunction 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 that operates in conjunction 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, to transmit treatment data to and receive prescription orders from a physician or clinician server that interacts with a physician or clinician's computer.

[0084] 1 and 2, the fresh and used PD fluid lumens 52 and 54 of the dual lumen patient line 50 may again be reusable or disposable. In the instance where the dual lumen patient line 50 is reusable, the lumens terminate in a connector 56 that connects to a lumen connector 104 of the filter set 100, which is sealed (e.g., ultrasonically welded, heat sealed, solvent bonded) to (or alternatively molded with) the body 106 of the filter set. As shown in FIG. 1, the body 106 is connected to a short (e.g., flexible) tube 108 that extends to a transfer set connector 110 that connects directly to a mating connector of the patient's transfer set 58. The short (e.g., flexible) tube 108 allows the rigid lumen connector 104 and body 106 to be separated from the rigid transfer set connector 110 to aid in patient comfort. Forming the body 106 to include the transferset connector 110 or attaching the transferset connector 110 to the body 106 and then connecting these rigid structures to the patient's rigid transferset 58 can result in a combined rigid assembly that is uncomfortable and tethered to the patient P. The space provided by the tube 108 separates the body 106 from the transferset connector 110, such that only the rigid transferset connector is mechanically connected to the patient's transferset 58. However, in alternative embodiments, the transferset connector 110 can be formed with or attached to the body 106.

[0085] The packaged filter set 100 may be provided with removable caps (not shown, assuming the dual lumen patient line 50 is reusable) on both ends of the filter set 100 to maintain sterility after the set has been sterilized, for example via gamma radiation, steam or ethylene oxide. To use the filter set 100, the patient or user removes and discards the caps.

[0086] 2, the lumen side connector 104 may simply include ports, such as fresh and used PD fluid ports 104f and 104u, over which or into which the fresh and used PD fluid lumens 52 and 54 extend for sealing, respectively. If the dual lumen patient line 50 is reusable, the patient line connector 56 may include releasable clamps that releasably clamp onto the fresh and used PD fluid ports 104f and 104u (e.g., compressing gaskets that interact between the patient line connector 56 and the PD fluid ports 104f and 104u). If the dual lumen patient line 50 is disposable, the fresh and used PD fluid lumens 52 and 54 may be ultrasonically sealed, heat sealed, or solvent bonded to the fresh PD fluid port 104f and the used PD fluid port 104u, respectively.

[0087] 2, in one embodiment, the fresh and used ports 104f and 104u of the lumen side connector 104 are surrounded by a threaded shroud 104s, which may form a threaded luer-type connection with a mating patient line connector 56, where the patient line connector 56 is configured to thread into the threaded shroud 104s to cause the patient line connector 56 to compress a gasket (not shown) and seal the mating fresh and used PD fluid ports of the patient line connector 56 to the fresh PD fluid port 104f and used PD fluid port 104u, respectively. The gasket may be fitted over and / or into the fresh and used PD fluid ports 104f and 104u of the lumen side connector 104. The patient line connector 56 can include fresh and used PD fluid ports 104f and 104u that extend into the fresh and used PD fluid ports 104f and 104u of the lumen side connector 104. In one embodiment, a gasket provides a port seal between the mating fresh and used PD fluid ports of the patient line connector 56 and the lumen side connector 104.

[0088] 3, the lumen-side connector 104 and the body 106 may be referred to herein as the filter housing 102. The filter housing 102, the transfer set-side connector 110, the cap (not shown), and any other rigid or semi-rigid polymers associated with the filter set 100 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"). The compressible gasket 112 may be formed from silicone rubber, PVC, or other similar elastomeric materials, such as styrene-ethylene-butylene-styrene ("SEBS") or isoprene. The flexible tube 108 may be made of PVC or a non-PVC material such as polybutadiene ("PBD") or PP.

[0089] FIG. 3 shows a top view of the body 106 of the filter housing 102 with its lid 1061 (FIG. 2) and filter membrane 120 (FIG. 4) removed, thereby exposing the filtered fluid compartment 106f of the body 106. Fresh PD fluid filtered through the filter membrane 120 (FIG. 4) flows into the filtered fluid compartment 106f. FIGS. 1-3 further illustrate that, in one embodiment, fresh, further filtered PD fluid flows from the filtered fluid compartment 106f of the body 106 through the transfer set side port 106p, through the short tubing 108 of the filter set 100, through the patient's transfer set 58, and into the peritoneal cavity of the patient P. The transfer set side port 106p extends from, e.g., is molded therewith, the body 106 of the filter housing 102. A short tube 108 (FIG. 1) extends over (or alternatively into) the transferset side port 106p and is ultrasonically sealed, heat sealed, or solvent bonded to the transferset side port 106p.

[0090] 3 and 4 show that the body 106 includes a bottom surface 106b from which extends a series of support ribs 106r (FIGS. 3-5). The series of ribs 106r extend upwardly from the bottom surface 106b to support the flat sheet filter membrane 120 under both positive pressure applied above the flat sheet filter membrane 120 and negative patient drain pressure applied below the flat sheet filter membrane 120. The support ribs 106r are spaced apart from one another to allow fresh filtered PD fluid to flow through the filtered fluid compartment 106f to the outlet 106o in the direction of the arrow (left to right) adjacent the support ribs 106r in FIG. 4. In one embodiment, the series of ribs 106r, the bottom surface 106b, the continuous inner wall 106i and the continuous outer wall 106s of the body 106 are molded as a single piece. The lumen side connector 104 and the transfer set side port 106p may also be molded as part of the single piece body 106.

[0091] A cross section of the filter membrane 120 is shown in FIG. 4, where a series of ribs 106r can also be seen. However, it should be understood that the filter membrane 120, in one embodiment, is sized to extend across the entire series of ribs 106r and seal (e.g., ultrasonically seal, heat seal or solvent bond) against the continuous inner wall 106i of the body 106, such as the continuous raised lip 106j formed in the continuous inner wall 106i. The flat sheet filter membrane 120, in one embodiment, is made of a hydrophilic material that may have a pore size of about 0.2 microns, and fresh PD fluid flows through the membrane for further filtration. The filter membrane 120 may be made of, for example, polysulfone or polyethersulfone mixed with polyvinylpyrrolidone. The flat sheet filter membrane 120 is sized (length and width) to provide the necessary filtration required over multiple patient fills of PD treatment before being discarded after treatment. The flat sheet filter membrane 120 may be a sterilizing grade filter membrane or a bacteria reduction filter membrane.

[0092] 4 and 5 show that the continuous inner wall 106i defines an outlet 106o (e.g., a hole or opening). The outlet 106o is provided at an end of the continuous inner wall opposite the fresh PD fluid inlet end of the continuous inner wall. The outlet 106o allows fresh filtered PD fluid to exit the filtered fluid compartment 106f (bounded by the bottom of the filter membrane 120, the inside of the continuous inner wall 106i, and the top end of the bottom surface 106b of the body 106) and flow through the transfer set side port 106p to the patient. In one embodiment, the outlet 106o is molded into the continuous inner wall 106i.

[0093] 3-5 further illustrate that the body 106 includes or forms a continuous outer wall 106s. The lumen connector 104 and the transfer set port 106p in the illustrated embodiment extend from the continuous outer wall 106s, for example. The continuous outer wall 106s and the continuous inner wall 106i are spaced apart to form an intermediate circumferential spent PD fluid channel 106c. The circumferential spent PD fluid channel 106c can have a width of 1 millimeter ("mm") or more, e.g., about 1 mm, and a depth of 4 mm or more, e.g., about 5 mm. The overall cross-sectional area of ​​the circumferentially surrounding spent PD fluid channel 106c is large enough to allow spent PD fluid (which typically contains patient material such as fibrin and proteins, which clog the flat sheet filter membrane 120 over the course of multiple patient drains) to flow rather freely around the flat sheet filter membrane 120 toward the spent PD fluid lumen 54 of the dual lumen patient line 50 (FIG. 1).

[0094] 4 perhaps best illustrates that the lid 106l is ultrasonically sealed, heat sealed, or solvent bonded to both (i) the continuous inner wall 106i and (ii) the continuous outer wall 106s of the body 106 to complete the filter housing 102. Prior to sealing the lid 106l to the (i) the continuous inner wall 106i and (ii) the continuous outer wall 106s of the body 106, the flat-sheet filter membrane 120 is ultrasonically sealed, heat sealed, or solvent bonded around its periphery to the continuous raised lip 106j formed in the continuous inner wall 106i. The lid 106l is then sealed to the outer portion of the continuous inner wall 106i, thereby sealing both the flat-sheet filter membrane 120 and the lid 106l to the continuous inner wall. Sealing the lid 106l to both (i) the continuous inner wall 106i and (ii) the continuous outer wall 106s encloses a top-circumferential spent PD fluid channel 106c, thereby preventing spent PD fluid returning from the patient from spilling into the pressurized compartment 106e (FIG. 4) located upstream of the flat sheet filter membrane 120.

[0095] In one embodiment, the continuous outer wall 106s includes or defines a continuous centering seal rib (not shown) that receives a mating groove (not shown) formed along the underside perimeter of the lid 106l (or vice versa). The fit of the seal rib into the groove ensures that the lid 106l is properly positioned for ultrasonic sealing, heat sealing or solvent bonding to the continuous outer wall 106s. A rib-and-groove fit may also be made for ultrasonic sealing, heat sealing or solvent bonding between the lid 106l and the continuous inner wall 106i. Similarly, the interior of the continuous inner wall 106i may be provided with a continuous (or beaded) ring of material (not shown) that indicates the location of the installed flat-sheet filter membrane 120. The ring of material may help center the installed flat-sheet filter membrane 120 and / or provide additional material to help ultrasonically seal, heat seal or solvent bond the filter membrane 120 to the continuous inner wall 106i.

[0096] The arrows in Figure 3 show the flow path of both fresh and spent PD fluid through filter set 100. The arrows in Figure 4 show the flow path of fresh PD fluid through filter set 100. The arrows in Figure 5 show the flow path of spent PD fluid through filter set 100.

[0097] 3 and 4 show that fresh PD fluid enters the filter set 100 through the fresh PD fluid port 104f in the lumen-side connector 104 and flows toward the continuous inner wall 106i. The continuous inner wall 106i deflects and urges the fresh PD fluid, causing it to change direction and flow upward over the continuous inner wall 106i and into the pressurized section 106e, which is upstream of the flat sheet filter membrane 120. The pressurized section 106e is sized to distribute the fresh PD fluid across the upstream of the filter membrane 120 for uniform distribution of the PD fluid through the porous membrane. The fresh PD fluid is pressurized in the pressurized section 106e (FIG. 4). Pressurization forces the fresh PD fluid through small pores in the flat-sheet filter membrane 120 and into the filtered fluid compartment 106f (FIG. 4) of the body 106, which is bounded primarily by the lower surface of the flat-sheet filter membrane 120, the bottom surface 106b of the body 106, and a continuous interior wall 106i. The fresh PD fluid flows along and between a series of ribs 106r in the filtered fluid compartment 106f until it exits through an outlet 106o formed in the continuous interior wall 106i. The exiting fresh filtered PD fluid flows to the patient through a transfer set-side port 106p.

[0098] 3 and 5 show the flow of spent PD fluid through the filter set 100, where the transferset side port 106p extends to the entrance of the spent PD fluid channel 106c, which resides between and is defined by a continuous inner wall 106i and a continuous outer wall 106s. The spent PD fluid channel 106c in the illustrated embodiment extends from the transferset side port 106p to the spent PD fluid port 104u of the lumen side connector 104. The spent PD fluid channel 106c also extends below the fresh PD fluid port 104f, such that spent PD fluid can flow through the spent PD fluid channel 106c in both clockwise and counterclockwise directions, as shown in FIG. 3. The spent PD fluid port 104u is in sealed and fluid communication with the spent PD fluid lumen 54 of the dual lumen patient line 50 during operation, as previously described.

[0099] The spent PD fluid channel 106c allows the spent PD fluid to be drawn bidirectionally around the body 106 of the filter housing 102 without contacting (or very minimally contacting) the filter membrane 120 and potentially clogging the filter membrane 120. The spent PD fluid channel 106c provides an unobstructed, streamlined path for the spent PD fluid, which helps to mitigate pressure loss through the filter set 100.

[0100] Although it is fluidly possible for the spent PD fluid to flow through the outlet 106o provided in the continuous inner wall 106i and into the filtered fluid compartment 106f of the body 106, there is little incentive for the spent PD fluid to flow into the filtered fluid compartment 106f because negative pressure is applied only from within the spent PD fluid port 104u and the spent PD fluid channel 106c. The control unit 40 of the PD machine 20 is also configured to close the fresh PD fluid valve 26a during patient drain, urging the spent PD fluid to flow along the spent PD fluid channel 106c rather than into the filtered fluid compartment 106f. Similarly, it is fluidly possible for the fresh PD fluid to flow in the reverse direction back up the spent PD fluid channel 106c during patient fill, but the required change of direction makes such a path much more tortuous than simply flowing to the patient P through the transfer set side port 106p. The spent PD fluid channel 106c and the spent PD fluid lumen 54 of the dual lumen patient tubing 50 will also likely fill with fresh and / or used PD fluid during patient fill, and the spent PD fluid lumen 54 will be closed via the spent PD fluid valve 26b in the PD machine or cycler 20, thus leaving little or no room for fresh PD fluid to enter the spent PD fluid channel 106c.

[0101] FIG. 6 illustrates an alternative lumen side connector 104, where the connector 104 includes a dual lumen connector 104d instead of individual fresh and used PD fluid ports 104f. The dual lumen connector 104d includes or defines a fresh PD fluid opening 104g and a used PD fluid opening 104h, with corresponding dual lumen connectors 56 for the fresh PD fluid lumen 52 and the used PD fluid lumen 54 extending into the fresh PD fluid opening 104g and the used PD fluid opening 104h, respectively, for sealing. If the dual lumen patient line 50 is reusable, the patient line connector 56 may compress a gasket that interacts between the patient line connector 56 and the fresh and used PD fluid openings 104g, 104h. If the dual lumen patient line 50 is disposable, the fresh and used PD fluid lumens 52 and 54 may be ultrasonically sealed, heat sealed, or solvent bonded to the fresh PD fluid port 104f and the used PD fluid port 104u, respectively. The lumen side connector 104, including the dual lumen connector 104d, may be provided with a threaded shroud 104s that may form a threaded luer type connection with a mating patient line connector 56, where the patient line connector 56 is configured to thread into the threaded shroud 104s to cause the patient line connector 56 to compress a gasket (not shown) to seal mating fresh and spent PD fluid ports of the patient line connector 56 to fresh PD fluid openings 104g and spent PD fluid openings 104h, respectively. The lumen side connector 104, including the dual lumen connector 104d, may be molded with the body 106 of the filter housing 102, as described herein.

[0102] 2, 7, and 8 further show that the lid 106l may be provided with vent openings 106v, which allow air to escape from the fresh PD fluid before being filtered through the filter membrane 120. To maintain sterility within the body 106, one or more hydrophobic membranes 122a, 122b (FIG. 8), etc., are ultrasonically sealed, heat sealed, or solvent bonded to the inner surface of the lid 106 around its / their respective vent openings 106v so as to surround and cover them. The hydrophobic membranes 122a, 122b, etc. may be made, for example, from polytetrafluoroethylene ("PTFE"). Although multiple sets of vent openings 106v and corresponding hydrophobic membranes 122a, 122b are shown as being provided in the lid 106l, only a single set of vent openings and corresponding hydrophobic membranes may be provided in the lid 106l.

[0103] The one or more hydrophobic membranes 122a, 122b, etc., allow air to be vented to the atmosphere when fresh PD fluid is pressurized in the pressurized compartment 106e located below the lid 106l before being filtered through the hydrophilic filter membrane 120, which may improve the performance of the filter membrane 120 in addition to removing air from the filter set 100. In the illustrated embodiment of Figures 2, 4, 7 and 8, the lid 106l is provided with one or more protective protrusions 106t disposed adjacent the one or more vent holes 106v. The one or more protective protrusions 106t serve to prevent the one or more vent holes 106v from being covered by the patient, a blanket, etc. while the patient is sleeping during PD therapy.

[0104] With regard to priming the filter set 100 for treatment, the fresh PD fluid lumen 52 of the patient line 50 and the filter set 100 may or may not be primed with fresh PD fluid before the short tubing 108 is connected to the patient's transfer set 58. If primed, the user interface 48 may audibly, visually or audibly prompt the patient P to clip the patient line connector 56 and / or the filter set 100 to clips provided by the housing 22 of the PD machine or cycler 20. The short tubing 108 may first be attached with a cap (not shown) so that when the patient line connector 56 or the filter set 100 is clipped to the housing 22, the short tubing 108 hangs down from the filter set 100 and is closed to the environment via the cap. The control unit 40 then opens the fresh PD fluid valve 26a and causes the PD fluid pump 24 to prime the fresh PD fluid lumen 52 up to the filter membrane 120 with fresh PD fluid with the spent PD fluid valve 26b closed. Here, air is forced out through vent openings 106v.

[0105] Once the fresh PD fluid lumen 52 is fully primed, the pressure sensors 28a and 28b detect a pressure rise since the fresh PD fluid has nowhere to go with the spent PD fluid valve 26b closed. Now, experiencing a pressure rise, with the filter membrane 120 fully wetted, the control unit 40 causes the spent PD fluid valve 26b to open, allowing the PD fluid pump 24 to push fresh PD fluid through the hydrophilic filter membrane 120 to the filtered fluid compartment 106f, which pushes air through the inner compartment, into and through the circumferential spent PD fluid channel 106c to a portion of the spent PD fluid lumen 54. Thus, the air is forced up the spent PD fluid lumen 54 towards the system drain. Now, the control unit 40 can be programmed to know and actuate the number of known volumetric strokes of the PD fluid pump 24 required to adequately prime the desired portion of the filtered fluid compartment 106f, the circumferential spent PD fluid channel 106c, and the spent PD fluid lumen 54. At this point, the body 106 of the filter set 100 is fully primed. It should be appreciated that it is not necessary to clamp the filter set 100 to the housing 22 to perform the above-described priming of the body 106 of the filter set 100, although doing so may help prevent the dual lumen patient line 50 from kinking during such priming.

[0106] The user interface 48 of the PD machine or cycler 20 then audibly, visually or audiovisually prompts the patient P to remove the filter set 100 from the clip on the housing 22, remove the cap from the short tube 108, connect the short tube 108 to the patient's transfer set 58, and open the clamp on the patient's transfer set 58. Next, in one embodiment, the control unit 40, with the spent PD fluid valve 26b open and the fresh PD fluid valve 26a open or closed (likely closed), causes the PD fluid pump 24 to draw spent PD fluid from the patient to prime the short tube 108, which now draws air from the short tube through the spent PD fluid channel 106c that circumscribes the used PD fluid lumen 54 of the dual lumen patient line 50, toward the drain of the PD machine or cycler 20. Such drawing of spent PD fluid may be part of the patient's initial drain. Thus, the amount of spent PD fluid removed from the patient, in one embodiment, is counted in the control unit 40 (eg, by accumulating known volumetric strokes of the PD fluid pump 24) as part of the initial drain amount of the treatment.

[0107] Alternatively, if a patient fill is the first operation to be performed after priming the fresh PD fluid lumen 52 and the body 106 of the filter set 100, the control unit 40 may or may not fully prime the short tube 108 to draw effluent from the patient before beginning the initial patient fill. That is, it is contemplated that the control unit 40 may allow a small amount of air present in the short tube 108 to be pushed back into the patient. However, if the control unit 40 draws an initial amount of effluent from the patient to prime the short tube 108, the control unit 40 may count any amount of effluent drawn from the patient (e.g., by accumulating known volumetric strokes of the PD fluid pump 24) as part of the subsequent initial drain.

[0108] In an alternative embodiment, the filter set 100 is not clipped on the housing 22 and the short tubing 108 is first connected to the patient transfer set 58. The user interface 48 now audibly, visually or audiovisually advises the patient P to keep the patient transfer set 58 clamp closed until instructed to open the clamp. The procedure described above is then performed, with the patient transfer set clamp now performing the function of the cap on the end of the short tubing 108 in the above example. With the patient transfer set clamp closed, the control unit 40 causes fresh PD fluid to be primed through the fresh PD fluid lumen 52, the filter set body 106 and a portion of the spent PD fluid lumen 54 using the PD fluid pump 24 while sequencing the valves 26a and 26b as previously described.

[0109] In one embodiment, user interface 48 then prompts patient P to open the clamps on patient transfer set 58 and press a confirm button on user interface 48. When the confirm button is then pressed, control unit 40 sequences valves 26a and 26b and activates pump 24 as previously described to draw spent PD fluid from patient P's peritoneal cavity and prime short tube 108 and surrounding spent PD fluid channel 106c with patient effluent. The effluent priming of short tube 108 may again be part of the initial patient drain.

[0110] Drawing spent PD fluid from the patient to prime the short tube 108 assumes that there is spent PD fluid to be removed from the patient at the beginning of the treatment. This is the case in many cases where the patient is full of spent PD fluid at the beginning of the treatment from the last fill of a previous treatment or from a midday exchange. However, in some cases, the patient is dry at the beginning of the treatment. It is conceivable that the control unit 40 of the PD machine or cycler 20, which may be dedicated to a single patient at a given time, knows the treatment schedule of the patient and therefore knows when the next treatment begins with the patient in a dry state with no or little PD fluid used. Here, it is conceivable that the control unit 40, instead of attempting to completely drain the patient at the final drain of the previous treatment, allows some residual amount of effluent to remain in the patient's peritoneal cavity after the treatment. The residual amount may be, for example, 50 milliliters ("ml") or more as required to ensure that the patient's indwelling PD catheter has access to the residual effluent. The residual amount should be sufficient to prime any air through the proximal end of the short tube 108 at least at the junction of the filter set 100.

[0111] The above priming procedure is advantageous for several reasons. First, it may eliminate having the patient clip the patient line connector 56 to a clip provided by the housing 22 of the PD machine or cycler 20. It may also eliminate the need for the patient line connector 56 to be mated with a vent cap and / or for the housing 22 of the PD machine or cycler 20 to have a sensor to detect when fresh PD fluid reaches the patient line connector 56. Both savings reduce cost and complexity. Second, after treatment, the patient may disconnect the transfer set connector 110 from the patient's transfer set 58 and then seal the transfer set 58 with a cap (not shown) having a disinfectant such as iodine, helping to prevent peritonitis due to, for example, patient contact contamination. The cap is then removed and replaced with a new transfer set connector 110 of a new filter set 100 at the start of the next treatment. However, residual disinfectant, such as residual iodine, remains. The priming method disclosed herein carries residual disinfectant away under negative pressure into the spent PD fluid lumen 54 of the dual lumen patient line 50 instead of sending it to the patient. Doing so prevents health issues, especially for sensitive patients.

[0112] It should be understood that various modifications and changes to the presently preferred embodiment described herein will be apparent to those skilled in the art.It is therefore intended that any or all of such modifications and changes may be covered by the appended claims.For example, the dual lumen patient line 50 may alternatively be a single lumen patient line, and the filter set 100 may include check valves provided in the fresh and spent PD fluid ports 104f, 104u of the lumen side connector 104, for example, to direct the fresh and spent PD fluid to desired locations within the set.

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); Equipped with The filter set (100) includes a filter membrane (120) positioned and arranged so that fresh PD fluid flows through the filter membrane (120) into a filtered fluid compartment (106f), the filtered fluid compartment (106f) including an outlet (106o) to a port (106p) that is in fluid communication with a circumferentially surrounding spent PD fluid channel (106c), the circumferentially surrounding spent PD fluid channel (106c) positioned and arranged to transport spent PD fluid bidirectionally around the filter membrane (120) without contacting or limiting contact with the filter membrane (120).

2. 2. The PD system of claim 1, wherein the patient line is a dual lumen patient line including a fresh PD fluid lumen and a spent PD fluid lumen, the spent PD fluid lumen being positioned in fluid communication with the surrounding spent PD fluid channel.

3. 3. The PD system of claim 2, wherein the filter set includes a fresh PD fluid port for fluid communication with the fresh PD fluid lumen and a spent PD fluid port for fluid communication with the spent PD fluid lumen.

4. The PD system (10) of claim 3, wherein the circumferential spent PD fluid channel (106c) is in fluid communication with the spent PD fluid port (104u).

5. The PD system (10) of any one of claims 1 to 4, wherein the port (106p) extends to a circumferentially surrounding spent PD fluid channel (106c).

6. The PD system (10) of any one of claims 1 to 4, wherein the circumferential spent PD fluid channel (106c) is located between a continuous inner wall (106i) and a continuous outer wall (106s).

7. The PD system (10) of claim 6, wherein the filter set (100) includes a lid (106l) sealed to at least one of the continuous inner wall (106i) and the continuous outer wall (106s).

8. 8. The PD system (10) of claim 7, wherein the lid (106l) includes at least one vent opening (106v) and at least one hydrophobic membrane (122a, 122b) sealingly covering the at least one vent opening (106v).

9. 7. The PD system of claim 6, wherein the continuous inner wall is positioned and arranged to deflect incoming fresh PD fluid above the filter membrane.

10. The PD system (10) of any one of claims 1 to 4, comprising at least one rib (106r) located within the filtered fluid compartment (106f) for supporting the filter membrane (120).

11. 5. The PD system (10) of claim 1, wherein the filter membrane (120) is a flat-sheet filter membrane, and the filter set (100) includes a pressurization compartment (106e) located on the opposite side of the flat-sheet filter membrane from the filtered fluid compartment (106f).

12. 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 (108) configured to connect to the patient's transfer set.

13. 5. The PD system of claim 1, wherein the PD machine is configured to close a spent PD fluid valve during patient fill and force the filtered fresh PD fluid to flow to the port rather than along the circumferential spent PD fluid channel.

14. 5. The PD system of claim 1, wherein the PD machine is configured to close a fresh PD fluid valve during patient drainage, forcing spent PD fluid to flow along the circumferential spent PD fluid channel rather than into the filtered fluid compartment.

15. A filter set (100), comprising: a filtered fluid compartment (106f) including an outlet (106o); a filter membrane (120) positioned and arranged so that fresh PD fluid flows through the filter membrane (120) into the filtered fluid compartment (106f); a surrounding spent PD fluid channel (106c) in fluid communication with the outlet (106o); Equipped with The filter set (100) has a circumferentially surrounding spent PD fluid channel (106c) positioned and arranged to transport spent PD fluid in two directions around the filter membrane (120) without contacting or limiting contact with the filter membrane (120).

Images