Dialysis system and method including flow path isolator

Abstract

A peritoneal dialysis system (10) includes a cycler (20), a disposable set operable with the cycler (40) and including a patient line (50) and an exhaust line (56), one of (i) a water purifier (210) to supply water for mixed purification to form fresh dialysis fluid at the disposable set (40), (ii) at least one container of fresh dialysis fluid provided as part of the disposable set (40) for supplying fresh dialysis fluid, or (iii) a dialysis fluid preparation unit configured to supply fresh dialysis fluid to the disposable set (40), and at least one flow path isolator (250) disposed at the cycler (20), the water purifier (210), the dialysis fluid preparation unit, and / or along the exhaust line (56), the flow path isolator (250) configured to separate used dialysis fluid flowing along the exhaust line (56) into flow segments to limit any electrical current from the patient to the exhaust.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to medical devices. More particularly, the present disclosure relates to electrical isolation of medical devices. BACKGROUND

[0002] A person's renal system can fail for a variety of reasons. Kidney failure causes a variety of physiological disturbances. It is no longer possible to balance water and minerals or to excrete the daily metabolic load. Toxic metabolic end products, such as urea, creatinine, uric acid, etc., can accumulate in a patient's blood and tissues.

[0003] Kidney function decline, especially kidney failure, is treated by dialysis. Dialysis removes waste, toxins and excess water from the body that a normally functioning kidney would otherwise remove. Dialysis treatment to replace kidney function is vital for many people because the treatment is life-saving.

[0004] One type of kidney failure therapy is hemodialysis ("HD"), which generally uses diffusion to remove waste products from a patient's blood. Diffusion gradients occur across a semi-permeable dialyzer between the blood and an electrolyte solution called dialysate or dialysis fluid to cause diffusion.

[0005] Hemofiltration ("HF") is an alternative renal replacement therapy that relies on convective transport of toxins from a patient's blood. HF is accomplished by adding a replacement or substitution fluid to the extracorporeal circuit during treatment. During HF treatment, ultrafiltration of the fluid replaced and accumulated by the patient during treatment provides a convective transport mechanism that is particularly beneficial for removal of middle and large molecules.

[0006] Hemodiafiltration ("HDF") is a treatment modality that combines convective and diffusive clearance. HDF uses dialysis fluid that is passed through a dialyzer, similar to standard hemodialysis, to provide diffusive clearance. In addition, a substitution solution is provided directly to the extracorporeal circuit, providing convective clearance.

[0007] Another type of kidney failure therapy is peritoneal dialysis ("PD"), which infuses a dialysis solution, also called dialysis fluid, into a patient's peritoneal cavity via a catheter. The dialysis fluid contacts the peritoneum of the peritoneal cavity. Waste, toxins and excess water pass from the patient's blood, through the peritoneum, and into the dialysis fluid, i.e., there is an osmotic gradient across the membrane due to diffusion and osmosis. Osmotic agents in the PD dialysis fluid provide the osmotic gradient. Used or spent dialysis fluid is drained from the patient, removing waste, toxins and excess water from the patient. The cycle is repeated, for example, multiple times.

[0008] 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. Here, a patient manually connects an implanted catheter to a drain to allow used or spent dialysis fluid to drain from the peritoneal cavity. The patient then switches the fluid communication so that the patient catheter is in communication with a bag of fresh dialysis fluid to infuse fresh dialysis fluid through the catheter and into the patient. The patient disconnects the catheter from the fresh dialysis fluid bag and allows the dialysis fluid to dwell within the peritoneal cavity, where the transfer of waste, toxins, and excess water occurs. After the dwell period, the patient repeats the manual dialysis process, for example, four times per day. Manual peritoneal dialysis requires a great deal of time and effort from the patient, leaving room for improvement.

[0009] Automated peritoneal dialysis ("APD") is similar to CAPD in that the dialysis treatment includes drain, fill, and dwell cycles. However, an APD machine typically performs the cycles automatically while the patient is sleeping. The APD machine fluidly connects to the implanted catheter, a source or bag of fresh dialysis fluid, and a fluid drain. The APD machine pumps fresh dialysis fluid from the dialysis fluid source through the catheter and into the patient's peritoneal cavity. The APD machine also allows the dialysis fluid to dwell within the cavity and allows the transfer of waste, toxins, and excess water to occur. The source can include a plurality of sterile dialysis fluid solution bags.

[0010] The APD machine pumps used or spent dialysis fluid from the peritoneal cavity through the catheter and to the drain. Like the manual process, several drain, fill, and dwell cycles occur during dialysis. A "last fill" can occur at the end of the APD treatment. Fluid can remain in the patient's peritoneal cavity until the start of the next treatment, or the fluid can be manually emptied at some point during the day.

[0011] Medical devices are designated into different electrical categories. For example, cardiac float "CF" machines are machines that have components ("applied components") that can make direct conductive contact with a patient's heart. Examples of CF machines are cardiopulmonary machines, external pacemakers, electrosurgical devices, pacemakers, and defibrillators. Body float "BF" machines have applied components that can make conductive contact with a patient or intermediate or long-term contact with a patient. Examples of BF machines include monitors, incubators, and ultrasound equipment. Body ("B") machines have applied components that are generally not conductive and can be released from a patient immediately. Examples of B machines include light emitting diode ("LED") lighting, medical lasers, MRI body scanners, hospital beds, and photographic equipment. The applied components of CF and BF have a floating patient ground, while B machines can be connected to a ground.

[0012] The APD machine operates with a patient line that extends to the patient's peritoneal cavity and, in many cases, a drain line that extends to a housing drain, such as a toilet, a bath, or a sink. The toilet, bath, or sink establishes a ground relative to the patient and the APD machine. During the drain phase of an APD treatment involving the housing drain, the APD machine pumps used dialysis fluid from the patient's peritoneal cavity to the housing drain and the associated ground. Dialysis fluid, as well as used dialysis fluid, is electrically conductive. Thus, the drain path creates a potential conductive path from the patient to the housing drain. The primary resistance of the conductive path can involve only the fluid pumping mechanism, e.g., a pneumatic actuated membrane pump, for which a leaking fluid valve initiates an unbroken current path from the patient to the ground.

[0013] Thus, there is a need to provide a mechanism and associated method for preventing an unbroken current path from a patient to a ground during a peritoneal dialysis treatment. SUMMARY

[0014] The present disclosure provides a peritoneal dialysis ("PD") system and method that provides a flow path isolator that can be positioned along or operate with a drain line of a disposable set that operates with a cycler of the PD system. The flow path isolator creates a floating patient ground to protect the patient during treatment. There can be one or more portions of the drain line that operate with the flow path isolator, such as a portion of the drain line that extends along the cycler, a portion of the drain line that is downstream of the cycler, a portion of the drain line that extends to a water purifier, and / or a portion of the drain line that extends to a dialysis fluid preparation unit.

[0015] Various ways of obtaining and maintaining a flow path section or discontinuous, separate flow of used dialysis fluid are discussed in detail herein. Alternatively or additionally, the electrical resistance of the electrical current within the flow of used dialysis fluid is increased to the extent that any leakage current is reduced to a safe level.

[0016] In a first embodiment, which can be combined with any other flow path isolator embodiment described herein, a peritoneal dialysis system provides a flow path isolator that includes a first pump positioned and arranged to pump used dialysis fluid through a drain line to a first chamber and a second pump positioned and arranged to pump used dialysis fluid from an outlet of the first chamber to a second chamber. The separation of the first chamber and the second chamber creates a flow section. The first pump and the second pump can be the same or different types as the main pump of the cycler and can be, for example, peristaltic or gear pumps that operate with the drain line.

[0017] In various embodiments of the first embodiment, the first pump is disposed at the circulator, while the second pump or additional pump is disposed at (i) the water purifier, (ii) the dialysis fluid preparation unit, or (iii) along the drain line. The first pump and the second pump can alternatively both be disposed at the circulator, the water purifier, or the dialysis fluid preparation unit. In various embodiments of the first embodiment, the first chamber and the second chamber are respectively disposed at (i) the circulator, (ii) the water purifier, (iii) the dialysis fluid preparation unit, or (iv) along the drain line.

[0018] In one embodiment, the flow path isolator of the first embodiment cycles between two states. In one state, there is no flow of effluent between the first chamber and the second chamber. In the second state, there is no flow of effluent between the first pump and the first chamber. Thus, due to the no-flow conditions of the first state and the second state, there is always an air gap.

[0019] In the second embodiment, any portion of which can be combined with any other flow path isolator embodiment described herein, a peritoneal dialysis system provides a flow path isolator including a first valve operable with a first fluid line and a second valve operable with a second fluid line, the first fluid line and the second fluid line leading to a chamber, the system configured to sequentially operate the first valve and the second valve to create flow segments. In one embodiment, the second flow path isolator further includes a pump positioned and arranged to pump used dialysis fluid from an outlet of the first chamber to an additional second chamber. The valves and the pump can be (i) of the same or different type as the valves and the pump of the circulator, where the pump can be, for example, a peristaltic or gear pump operable with the drain line, and (ii) located at one or more of the circulator, the water purifier, or the dialysis fluid preparation unit. The addition of the second chamber and the pump allows for a state in which there is no flow of effluent between the first chamber and the second chamber, which is provided in addition to fluid separation due to the sequential operation of the two valves feeding the first chamber.

[0020] In the third embodiment, any portion of which can be combined with any other flow path isolator embodiment described herein, a peritoneal dialysis system provides a flow path isolator including a first pump and a second pump, the first pump positioned and arranged to pump used dialysis fluid through a drain line, the second pump positioned and arranged to introduce air or water into the drain line to create flow segments. In the case where the intermediate medium is water, the water is deionized to provide a non-conductive gap between conductive segments of used dialysis fluid. The deionized water can be provided by a water purifier or from a separate deionized water source.

[0021] In various embodiments of the third embodiment, the first pump is disposed at the cycler, e.g., is one of the cycler's main pumps, while the second pump is disposed at (i) the water purifier, (ii) the dialysis fluid preparation unit, or (iii) along the drain line. The second pump can be of the same or different type as the first pump. Alternatively, both the first and second pumps can be disposed at the cycler, water purifier, or dialysis fluid preparation unit.

[0022] In a fourth embodiment, which can be combined with any other flow path isolator embodiment described herein, a peritoneal dialysis system provides a flow path isolator comprising a length of coiled tubing configured to create high electrical resistance to any leakage current generated in the drain line. The length of coiled tubing can or can not naturally create a flow segment or pocket. The length of coiled tubing can be disposable and located downstream of the cycler, or reusable and located within, e.g., the water purifier or dialysis preparation unit. In one example, the ratio of the length (L) of the length of coiled tubing (310) to the cross-sectional area (A) of the length of coiled tubing is 10000:8.

[0023] In a fifth embodiment, which can be combined with any other flow path isolator embodiment described herein, a peritoneal dialysis system provides a flow path isolator comprising a peristaltic pump configured to create a flow segment. The rotor and rollers of the pump can be configured to create a more pulsatile segmented flow than normal. The peristaltic pump can be located in the cycler, in the water purifier, in the dialysis fluid preparation unit, or positioned along the drain line. The peristaltic pump can also be the main treatment pump of the PD cycler.

[0024] In a sixth embodiment, which can be combined with any other flow path isolator embodiment described herein, a peritoneal dialysis system provides a flow path isolator comprising a suction device configured to create a flow segment or suck in water droplets and a chamber configured to collect the flow segment or droplets from the suction device. The suction device can be provided in the form of a nozzle having multiple openings that create a spray or mist of water droplets or flow segments. The suction device can be located in the cycler, in the water purifier, in the dialysis fluid preparation unit, or positioned along the drain line.

[0025] In a seventh embodiment, any portion of which can be combined with any other flow path isolator embodiment described herein, a peritoneal dialysis system provides a flow path isolator that includes a first siphon and a second siphon positioned and arranged to produce a discontinuous drain flow to a housing drain (e.g., a toilet, a bathtub, or a sink). Each siphon includes a siphon tube and a siphon chamber. The tube of the first siphon outputs to the chamber of the second siphon. The siphons function as a flow switch that cycles between not having sufficient drain pressure to push effluent out of the siphon and having sufficient drain pressure to produce a flow of effluent. The siphons can be provided in a water purifier, a dialysis fluid preparation device, or along a drain line.

[0026] In one embodiment, the first siphon and the second siphon operate in a first state and a second state. In the first state, effluent flows from the circulator to the chamber of the first siphon, where the first siphon chamber fills, establishing a drain pressure, while the second siphon chamber drains, losing drain pressure. Here, there is an effluent air gap between the first siphon chamber and the second siphon chamber. In the second state, effluent still flows from the circulator to the chamber of the first siphon, but here the first siphon chamber drains, losing drain pressure, while the second siphon fills, gaining drain pressure. Here, there is an effluent gap between the second siphon chamber and the housing drain. In one embodiment, to produce the first state and the second state, (i) the first siphon is configured to drain at a flow rate that is greater than the drain flow rate from the circulator to the first siphon, and (ii) the first siphon and the second siphon are configured such that their switching states between the first siphon establishing drain pressure and losing drain pressure and the second siphon losing drain pressure and establishing drain pressure occur simultaneously or substantially simultaneously, or vice versa.

[0027] In an eighth embodiment, any portion of which can be combined with any other flow path isolator embodiment described herein, a peritoneal dialysis system provides a flow path isolator that has a first chamber that includes an outlet toward but separate from a second chamber to produce a flow segment. A valve can be located in one or both of the lines that output to the first chamber and the second chamber. In various embodiments of the eighth embodiment, the first chamber is provided at a circulator, while the second chamber is provided at (i) a water purifier, (ii) a dialysis fluid preparation unit, or alongside thereof, or (iii) along a drain line. In other embodiments, both chambers are provided at or alongside the circulator, the water purifier, the dialysis fluid preparation unit, or along the drain line.

[0028] In a ninth embodiment, any portion of which can be combined with any other flow path isolator embodiment described herein, the flow path isolator includes a chamber that houses used dialysis fluid. The chamber is hinged by a hinge and is configured to tilt via the weight of the used dialysis fluid entering the chamber. When the chamber is tilted, the chamber sufficiently fills a siphon such that a discharge pressure within the siphon causes the used dialysis fluid to flow from the siphon to the housing drain. The chamber can be provided with a counterweight that returns the chamber to its original position after delivery of dialysis fluid. Alternatively, a biasing device (e.g., a spring) can be positioned and arranged to return the chamber to the fill position after tilting. An electrical switch that switches from a first state to a second state when the first chamber is tilted can also be provided to prevent used dialysis fluid from flowing from the circulator to the chamber until the chamber returns to its upright position and the switch returns to its first state.

[0029] In a tenth embodiment, any portion of which can be combined with any other flow path isolator embodiment described herein, the flow path isolator includes a container positioned upstream of a first chamber, where the first chamber is positioned upstream of a first pump, where the first pump is positioned upstream of a second chamber, and where the second chamber is positioned upstream of a second pump. The first and second pumps are operated sequentially to isolate used dialysis fluid flowing along the drain line to limit the flow of electrical current from the patient to the housing drain. In one embodiment, used dialysis fluid is prevented from flowing from the first chamber to the second chamber when used dialysis fluid flows from the second chamber to the housing drain to create a separate effluent stream.

[0030] In an eleventh embodiment, any portion of which can be combined with any other flow path isolator embodiment described herein, the flow path isolator is disposed at or alongside at least one of a circulator, a water purifier, a dialysis fluid preparation unit, or along the drain line. Here, the flow path isolator is configured to isolate used dialysis fluid flowing along the drain line by pumping the used dialysis fluid to a drain container during a drain phase and pumping the used dialysis fluid from the drain container to the housing drain during a fill and / or dwell phase to limit the flow of electrical current from the patient to the housing drain. In one embodiment, the flow path isolator of the eleventh embodiment includes a chamber in fluid communication with the drain container, where the chamber creates an air gap in the used dialysis fluid. A pump can be positioned downstream of the drain container that is actuated to pull effluent from the drain container to the housing drain during the fill and / or dwell phase.

[0031] In a twelfth embodiment, which can be combined with any other flow path isolator embodiment described herein, the flow path isolator includes a first chamber, a second chamber, and a pump downstream of the first chamber and the second chamber. A first inlet valve and a second inlet valve are placed in fluid communication with the first chamber and the second chamber, respectively. A first outlet valve and a second outlet valve are placed in fluid communication with the first chamber and the second chamber, respectively. The first inlet valve and the second inlet valve and the first outlet valve and the second outlet valve are sequentially operated so that used dialysis fluid flowing into one of the first chamber or the second chamber occurs simultaneously with removal of used dialysis fluid from the other of the first chamber or the second chamber to separate used dialysis fluid flowing along the drain line to limit current flow from the patient to the housing drain. In one embodiment, (i) in a first state, the first inlet valve and the second outlet valve are opened while the second inlet valve and the first outlet valve are closed, and (ii) in a second state, the second inlet valve and the first outlet valve are opened while the first inlet valve and the second outlet valve are closed. In one embodiment, used dialysis fluid is transported to the first chamber and the second chamber via a main pump of a cycler.

[0032] In a thirteenth embodiment, which can be combined with any other flow path isolator embodiment described herein, the flow path isolator includes a pivoting device or carriage that pivots back and forth under the weight of incoming used dialysis fluid or effluent to create flow segments. Used dialysis fluid flows continuously along a drain line and into a container having a pivoting device or carriage at the top of the container, wherein the pivoting device is configured so that used dialysis fluid falling into the carriage hits or contacts one side or the other of a middle wall that divides the carriage into two compartments. The side of the wall that is currently contacted belongs to the compartment that is being filled so that the compartment is isolated from ground at the end of the drain line. The side of the wall that is not currently contacted belongs to the other compartment that drains into the container, which in turn drains to the distal end of the drain line and to the housing drain so that the other compartment is isolated from the patient.

[0033] The flow path isolator of the thirteenth embodiment can be located at a cycler, a water purifier or dialysis fluid preparation unit that operates with the cycler, or anywhere along the drain line.

[0034] It is contemplated that when any flow path isolator embodiment described herein has a chamber into which used dialysis fluid flows, the chamber is provided as part of a water purifier or a dialysis fluid preparation unit, the chamber also accommodates at least one additional incoming fluid stream, for example, a stream of water purifier waste. The water purifier can be, for example, a reverse osmosis unit, an ultrafilter, or any other purifier having a waste output. This configuration uses a single chamber for multiple purposes. The at least one additional incoming fluid stream can or can not be provided with its own flow path isolator.

[0035] In view of the technical features set forth herein, but without limitation, in a first aspect, which can be combined with any other aspect (or part thereof) described herein, a peritoneal dialysis system comprises: a cycler; a disposable set comprising a patient line and a drain line, the cycler being configured to pump fresh dialysis fluid to a patient via the patient line and to pump used dialysis fluid from the patient via the drain line; one of: (i) a water purifier to be used for mixed purifying water to form fresh dialysis fluid in the disposable set, (ii) at least one container of fresh dialysis fluid provided as part of the disposable set for supplying fresh dialysis fluid, or (iii) a dialysis fluid preparation unit configured to supply fresh dialysis fluid to the disposable set; and at least one flow path isolator provided at or alongside at least one of the cycler, the water purifier, the dialysis fluid preparation unit, or along the drain line, the flow path isolator being configured to isolate used dialysis fluid flowing along the drain line to limit electrical current flow from the patient to the housing drain.

[0036] In a second aspect, which can be combined with any other aspect (or part thereof) described herein, the drain line extends to the water purifier such that at least a portion of the flow path isolator provided at or alongside said water purifier can isolate used dialysis fluid flowing along the drain line.

[0037] In a third aspect, which can be combined with any other aspect (or part thereof) described herein, the drain line extends to the dialysis preparation unit such that at least a portion of the flow path isolator provided at or alongside said dialysis fluid preparation unit can isolate used dialysis fluid flowing along the drain line.

[0038] In a fourth aspect, which can be combined with any other aspect (or part thereof) described herein, the drain line extends along the cycler such that at least a portion of the flow path isolator located at or alongside said cycler can isolate used dialysis fluid flowing along the drain line.

[0039] In a fifth aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes a first pump positioned and arranged to pump used dialysis fluid through the drain line to the first chamber and a second pump positioned and arranged to pump used dialysis fluid from the outlet of the first chamber to the second chamber, operation of the first and second pumps isolating the used dialysis fluid to limit current flow from the patient to the housing drain.

[0040] In a sixth aspect, which can be combined with any other aspect (or portion thereof) described herein, the first pump is provided at the circulator, the second pump is provided at or alongside the water purifier, the dialysis fluid preparation unit, or along the drain line.

[0041] In a seventh aspect, which can be combined with any other aspect (or portion thereof) described herein, the first pump is a main pump of the circulator.

[0042] In an eighth aspect, which can be combined with any other aspect (or portion thereof) described herein, the first and second chambers are provided at any one of the circulator, the water purifier, the dialysis fluid preparation unit, or along the drain line, respectively.

[0043] In a ninth aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes a first valve operable with the first fluid line and a second valve operable with the second fluid line, the first and second fluid lines leading to the chamber, the system configured to operate the first and second valves in sequence to isolate the used dialysis fluid to limit current flow from the patient to the housing drain.

[0044] In a tenth aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator further includes a pump positioned and arranged to pump used dialysis fluid from the outlet of the chamber to the second chamber, the system configured to operate the first and second valves and the pump in sequence to isolate the used dialysis fluid to limit current flow from the patient to the housing drain.

[0045] In an eleventh aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes a first pump positioned and arranged to pump used dialysis fluid through the drain line and a second pump positioned and arranged to introduce air or water into the drain line to create a used dialysis fluid flow separation segment to limit current flow from the patient to the housing drain.

[0046] In a twelfth aspect, which can be combined with any other aspect (or portion thereof) described herein, the first pump is disposed at the circulator and the second pump is disposed at or alongside the water purifier, the dialysis fluid preparation unit, or along the drain line.

[0047] In a thirteenth aspect, which can be combined with any other aspect described herein, any of the pumps is a peristaltic pump or a gear pump.

[0048] In a fourteenth aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes a chamber to contain used dialysis fluid, the chamber is hinged via a hinge and configured to tilt via a weight of the used dialysis fluid such that the used dialysis fluid is sufficient to fill a siphon portion such that a discharge pressure within the siphon portion causes the used dialysis fluid to flow out of the siphon portion.

[0049] In a fifteenth aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes at least one of (i) a biasing device positioned and arranged to return the chamber to a fill position after tilting, or (ii) a switch that switches from a first state to a second state when the first chamber is tilted to prevent the used dialysis fluid from flowing to the chamber until the switch returns to the first state.

[0050] In a sixteenth aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes a peristaltic pump configured to create a flow separation segment to limit the flow of electrical current from the patient to the housing drain.

[0051] In a seventeenth aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes an aspirator configured to create a flow separation segment to limit the flow of electrical current from the patient to the housing drain and a chamber configured to collect the flow separation segment from the aspirator.

[0052] In an eighteenth aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes a first siphon portion and a second siphon portion, wherein the system is configured to prevent the first siphon portion from creating sufficient discharge pressure for the used dialysis fluid to flow from the first siphon portion to the second siphon portion until the discharge pressure in the second siphon portion drops such that the used dialysis fluid does not flow out of the second siphon portion to isolate the used dialysis fluid flowing along the drain line to limit the flow of electrical current from the patient to the housing drain.

[0053] In a nineteenth aspect, which can be combined with any other aspect (or portion thereof) described herein, the first siphon includes a first siphon tube and a first siphon chamber, and the second siphon includes a second siphon tube and a second siphon chamber.

[0054] In a twentieth aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes a first chamber having an output directed toward, but separate from, a second chamber, a first valve upstream of the first chamber, and a second valve upstream of the second chamber, the first valve and the second valve being operated in sequence to isolate used dialysis fluid flowing along the drain line to limit the flow from the patient to the housing drain.

[0055] In a twenty-first aspect, which can be combined with any other aspect (or portion thereof) described herein, the first valve and the second valve are operated in sequence such that if the second valve is opened, used dialysis fluid is prevented from flowing to the first chamber, and the second valve is opened when the second chamber is empty.

[0056] In a twenty-second aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes a reservoir upstream of a first chamber, the first chamber being upstream of a first pump, the first pump being upstream of a second chamber, the second chamber being upstream of a second pump, the first pump and the second pump being operated in sequence to isolate used dialysis fluid flowing along the drain line to limit the flow from the patient to the housing drain.

[0057] In a twenty-third aspect, which can be combined with any other aspect (or portion thereof) described herein, used dialysis fluid is prevented from flowing from the first chamber to the second chamber when used dialysis fluid flows from the second chamber.

[0058] In a twenty-fourth aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes a first chamber, a second chamber, and a pump downstream of the first chamber and the second chamber, a first inlet valve and a second inlet valve in fluid communication with the first chamber and the second chamber, respectively, a first outlet valve and a second outlet valve in fluid communication with the first chamber and the second chamber, respectively, the first inlet valve and the second inlet valve and the first outlet valve and the second outlet valve being operated in sequence such that used dialysis fluid is removed from one of the first chamber and the second chamber at the same time used dialysis fluid flows into the other of the first chamber and the second chamber to isolate used dialysis fluid flowing along the drain line to limit the flow from the patient to the housing drain.

[0059] In a twenty-fifth aspect, which can be combined with any other aspect (or portion thereof) described herein, (i) in the first state, the first inlet valve and the second outlet valve are open, while the second inlet valve and the first outlet valve are closed, and (ii) in the second state, the second inlet valve and the first outlet valve are open, while the first inlet valve and the second outlet valve are closed.

[0060] In a twenty-sixth aspect, which can be combined with any other aspect (or portion thereof) described herein, used dialysis fluid is transported to the first and second chambers via the main pump of the circulator.

[0061] In a twenty-seventh aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator includes a pivoting device that pivots about a pivot axis, the pivoting device including a first compartment and a second compartment, the first and second compartments alternatingly filling and draining used dialysis fluid to isolate used dialysis fluid flowing along the drain line to limit electrical current flow from the patient to the housing drain.

[0062] In a twenty-eighth aspect, which can be combined with any other aspect (or portion thereof) described herein, at least one flow path isolator is disposed at or alongside a water purifier or dialysis fluid preparation unit, and the at least one flow path isolator includes at least one water purification device having a waste line output to the flow path isolator.

[0063] In a twenty-ninth aspect, which can be combined with any other aspect (or portion thereof) described herein, the peritoneal dialysis system includes at least one valve disposed along at least one respective waste line, the at least one valve being sequentially opened and closed to create flow path segments.

[0064] In a thirtieth aspect, which can be combined with any other aspect (or portion thereof) described herein, the at least one flow path isolator includes valves that are sequentially opened and closed to create flow path segments.

[0065] In a thirty-first aspect, which can be combined with any other aspect (or portion thereof) described herein, a peritoneal dialysis system (10) comprises: a cycler; a disposable set comprising a patient line and a drain line, the cycler being configured to pump fresh dialysis fluid to a patient via the patient line and to pump used dialysis fluid from the patient via the drain line; one of (i) a water purifier for purifying water for mixing to form fresh dialysis fluid at the disposable set, (ii) at least one container of fresh dialysis fluid provided as part of the disposable set for supplying fresh dialysis fluid, or (iii) a dialysis fluid preparation unit configured to supply fresh dialysis fluid to the disposable set; and at least one flow path isolator disposed at or alongside at least one of the cycler, the water purifier, the dialysis fluid preparation unit, or along the drain line, the flow path isolator being configured to isolate used dialysis fluid flowing along the drain line by pumping the used dialysis fluid to a drain container during a drain phase and from the drain container to a housing drain during a fill and / or dwell phase to limit electrical current flow from the patient to the housing drain.

[0066] In a thirty-second aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator comprises a chamber in fluid communication with the drain container, the chamber creating an air gap in the used dialysis fluid.

[0067] In a thirty-third aspect, which can be combined with any other aspect (or portion thereof) described herein, the flow path isolator comprises a pump downstream of the drain container, the pump being actuated during the fill and / or dwell phase.

[0068] In a thirty-fourth aspect, which can be combined with any other aspect (or portion thereof) described herein, a peritoneal dialysis system comprises: a cycler; a disposable set comprising a patient line and a drain line, the cycler being configured to pump fresh dialysis fluid to a patient via the patient line and to pump used dialysis fluid from the patient via the drain line; one of: (i) a water purifier for purifying water for mixing to form fresh dialysis fluid at the disposable set, (ii) at least one container of fresh dialysis fluid provided as part of the disposable set for supplying fresh dialysis fluid, or (iii) a dialysis fluid preparation unit configured to supply fresh dialysis fluid to the disposable set; and at least one flow path isolator disposed at or alongside at least one of the cycler, the water purifier, the dialysis fluid preparation unit, or along the drain line, wherein the flow path isolator comprises a length of coiled tubing dimensioned to increase electrical resistance to a leakage current present in used dialysis fluid flowing through the length of coiled tubing.

[0069] In a thirty-fifth aspect, which can be combined with any other aspect (or portion thereof) described herein, a ratio of a length (L) of the length of coiled tubing (310) to a cross-sectional area (A) of the length of coiled tubing (310) is 10000:8.

[0070] In a thirty-sixth aspect, which can be combined with any other aspect (or portion thereof) described herein, the patient line also serves as part of the drain line.

[0071] In a thirty-seventh aspect, which can be combined with any other aspect (or portion thereof) described herein, wherein any pump or valve operates under control of the at least one control unit.

[0072] In a thirty-eighth aspect, which can be combined with any other aspect (or portion thereof) described herein, wherein the at least one control unit is a control unit of the cycler, the water purifier, or the dialysis fluid preparation device.

[0073] In a thirty-ninth aspect, which can be combined with any other aspect (or portion thereof) described herein, the control unit comprises one or more processors and one or more memories.

[0074] In a fortieth aspect, which can be combined with any other aspect (or portion thereof) described herein, wherein the control unit of the cycler is in wired or wireless communication with the control unit of the water purifier or the dialysis fluid preparation device.

[0075] In additional aspects of the disclosure, methods incorporating the same can be provided. Figures 1-16any of the features, functions, and alternatives described in any of the figures Figures 1-16 any of the features, functions, and alternatives described in any of the figures

[0076] Accordingly, it is an advantage of the present disclosure to provide a peritoneal dialysis ("PD") system and method with electrical isolation.

[0077] It is a further advantage of the present disclosure to provide a PD system and method that actively prevents or reduces current caused by a fault condition by creating a flow segment and / or by increasing the resistance to the current.

[0078] It is a still further advantage of the present disclosure to provide a PD system and method that actively prevents or reduces current caused by a fault condition and is relatively easy and cost effective to implement.

[0079] It is a still further advantage of the present disclosure to provide a PD system and method with electrical isolation that is suitable for different types of PD fluid supply, including bagged, mixed online at the cycler, and mixed online upstream of the cycler.

[0080] Further, it is an advantage of the present disclosure to provide a PD system and method with electrical isolation that can be separate and located at different parts of the system.

[0081] In certain embodiments, it is advantageous to utilize different cycles of peritoneal dialysis treatment to create flow isolation. Here, for example, used dialysis fluid can be separated by pumping the fluid to a drain container during a drain phase and pumping the used dialysis fluid from the drain container to the housing drain during a fill and / or dwell phase. In doing so, the patient is always isolated from the ground located at the end of the drain line.

[0082] In certain embodiments, it is advantageous to use already existing equipment to implement the flow path isolation. For example, a cycler pump that pumps fresh dialysis fluid to the patient and removes used dialysis fluid from the patient can additionally be used as the only pump or as one of multiple pumps for operating the flow path isolator of the present disclosure. In another example, a water purifier pump that pumps water for purification can additionally be used as the only pump or as one of multiple pumps for operating the flow path isolator of the present disclosure. In another example, a dialysis fluid preparation unit pump that pumps water or online generated dialysis fluid for treatment can additionally be used as the only pump or as one of multiple pumps for operating the flow path isolator of the present disclosure.

[0083] Additional features, technical effects, and advantages are described in and will be apparent from the following DETAILED DESCRIPTION and the appended drawings. The features and advantages described herein are not all-inclusive and many additional features and advantages will be readily apparent to one of ordinary skill in the art in view of the following DETAILED DESCRIPTION and the appended drawings. Also, any particular embodiment does not have to have all of the described advantages to fall within the scope of the present inventive subject matter, and specific embodiments can be practiced without having all of the described features and advantages. Furthermore, it should be noted that the language used in the specification is principally intended to be read in a context of readability and instructional purpose, and not as a way to limit the scope of the inventive subject matter. BRIEF DESCRIPTION OF DRAWINGS

[0084] Figure 1 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use.

[0085] Figure 2 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use. Figure 1 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use.

[0086] Figure 3 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use.

[0087] Figure 4 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use.

[0088] Figure 5 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use.

[0089] Figure 6 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use.

[0090] Figure 7 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use.

[0091] Figure 8 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use.

[0092] Figure 9 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use.

[0093] Figure 10 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use.

[0094] Figure 11 is a front view of one embodiment of a medical fluid delivery system of the present disclosure having a dialysis fluid generation and flow path isolator generated at the point of use.

[0095] Figure 12is a side view of a twelfth embodiment of a flow path isolator of the present disclosure.

[0096] Figure 13A and Figure 13B is a side view of an eleventh embodiment of a flow path isolator of the present disclosure.

[0097] Figure 14 is a side view of a twelfth embodiment of a flow path isolator of the present disclosure.

[0098] Figure 15 is a perspective view of a thirteenth embodiment of a flow path isolator of the present disclosure.

[0099] Figure 16 is a side view of an alternative implementation of the multiple flow path isolator embodiments discussed herein, wherein at least one additional incoming fluid stream, e.g., a water purification device reject stream, is contained in one chamber as part of a water purifier or dialysis fluid preparation unit. DETAILED DESCRIPTION

[0100] System Overview

[0101] The examples described herein are applicable to any medical fluid treatment system that delivers medical fluid, can bag or mix medical fluid such as dialysis fluid, replacement fluid, or intravenous medication at the point of use, prior to treatment, and / or during treatment. The examples are particularly applicable to renal failure therapies such as all forms of peritoneal dialysis ("PD"), hemodialysis ("HD"), hemofiltration ("HF"), hemodiafiltration ("HDF"), and continuous renal replacement therapy ("CRRT"), collectively or individually referred to herein as renal failure therapies. In addition, the machines described herein can be used in a clinical or home environment. For example, the machines and associated methods can be employed in a center PD or HD machine that runs almost continuously throughout the day. Alternatively, the machines and methods can be used in a home PD or HD machine that is capable of running, for example, overnight while the patient is sleeping. The machines and methods discussed herein are also applicable to medical delivery applications. The following examples will be described in the setting of a peritoneal dialysis system that produces dialysis fluid at the point of use, but can alternatively be used to manufacture point of use treatment fluid for any of the above modalities. In addition, the present disclosure does not require the production of dialysis fluid at the point of use, and dialysis fluid can alternatively be pre-generated, provided in a container or bag.

[0102] Reference will now be made to the drawings wherein Figure 1, system 10 illustrates one embodiment of the present disclosure having a peritoneal dialysis system that produces dialysis fluid on an as-needed basis. System 10 includes a medical fluid delivery machine or cycler 20 and a water purifier 210. Suitable cyclers for cycler 20 include, for example, the and Cycler while understanding that these cyclers can be provided with updated programming to perform production of dialysis fluid on an as-needed basis by system 10 and use of the dialysis fluid. To this end, cycler 20 includes a control unit 22 having at least one processor and at least one memory. Control unit 22 also includes a wired or wireless transceiver for sending information to and receiving information from water purifier 210. Water purifier 210 also includes a control unit 212 having at least one processor and at least one memory. Control unit 212 also includes a wired or wireless transceiver for sending information to and receiving information from control unit 22 of cycler 20. Wired communication can be via, for example, an Ethernet connection, RS232, wired USB. Wireless communication can be performed via any one of Bluetooth TM , WiFi TM , Wireless Universal Serial Bus (“USB”), or infrared protocol or via any other suitable wireless communication technology.

[0103] Cycler 20 includes a housing 24 that houses equipment programmed via control unit 22 to prepare fresh dialysis solution on an as-needed basis, pumps fresh prepared dialysis fluid to patient P, allows dialysis fluid to reside in patient P, and then pumps used dialysis fluid to a drain. In the illustrated embodiment, water purifier 210 includes a drain line 214 to a drain 216, which for the flow path isolation examples described herein is a housing drain such as a toilet, a bathtub, or a sink. In embodiments, the equipment programmed via control unit 22 to prepare fresh dialysis solution on an as-needed basis includes equipment for a pneumatic pumping system including, but not limited to, (i) positive and negative pressure reservoirs, (ii) a compressor and vacuum pump or a single pump that produces both positive and negative pressure, (iii) a plurality of pneumatic pump chambers for delivering positive and negative pressure to a plurality of fluid valve chambers, (iv) a plurality of pneumatic pump chambers for delivering positive and negative pressure to a plurality of fluid pump chambers, (v) a plurality of electrically actuated on / off pneumatic solenoid valves, (vi) a plurality of electrically actuated variable orifice pneumatic valves, (vii) a heater for heating dialysis fluid when mixing dialysis fluid in one embodiment that is controlled by control unit 22, and (viii) an occluder for closing off the patient and drain lines in the event of an alarm and other situations.

[0104] In one embodiment, the plurality of pneumatic valve chambers and the plurality of pneumatic pump chambers are located on a front face or front surface of the housing 24 of the cycler 20. A heater is located inside the housing 24 and, in embodiments, includes a heating coil that contacts a heating tray or tray that is located on top of the housing 24, below a heating cover (not visible in FIG. 1). Figure 1

[0105] The cycler 20 in the illustrated embodiment includes a user interface 30 that is controlled by a control unit 22, which in embodiments includes a video controller for interacting with a video monitor 32 of the user interface. The video monitor can operate with a touch screen that is overlaid on the video monitor 32 for entering commands into the control unit 22 via the user interface 30. The user interface 30 can also include one or more electromechanical input devices, such as membrane switches or other buttons. The control unit 22 can also include an audio controller for playing sound files, such as voice-activated commands, at one or more speakers 34.

[0106] The water purifier 210 in the illustrated embodiment also includes a user interface 220. The user interface 220 includes a video monitor 222 that can also operate with a touch screen that is overlaid on the video monitor 222 for entering commands into the control unit 212. The user interface 220 can also include one or more electromechanical input devices, such as membrane switches or other buttons. The control unit 212 can also include an audio controller for playing sound files, such as alarm or warning sounds, at one or more speakers 224 of the water purifier 210.

[0107] With additional reference to Figure 2 , one embodiment of a disposable set 40 is shown. The disposable set 40 is also shown in Figure 1 cooperating with the cycler 20 to move fluid within the disposable set 40, for example, to mix dialysis fluid as discussed herein in cooperation with the cycler 20. The disposable set 40 in the illustrated embodiment includes a disposable cassette 42 that can include a planar rigid plastic piece that is covered on one or both sides by a flexible sheet. One of the flexible sheets presses against the housing 24 of the cycler 20 to form a pump valve membrane. Figure 2 The disposable cassette 42 is shown to include fluid pump chambers 44 that operate with the pneumatic pump chambers located at the housing 24 of the cycler 20 and fluid valve chambers 46 that operate with the pneumatic valve chambers located at the housing 24 of the cycler 20. The pump chambers 44 provide the main pump or pumping mechanism for the cycler 20.

[0108] Figure 1 and Figure 2 ​A disposable set 40 is shown that includes a patient line 50 that extends from a patient line port of the cassette 42 and terminates at a patient line connector 52. Figure 1 The patient line connector 52 is shown connected to a patient transfer set 54 that in turn is connected to a resident catheter located in the peritoneal cavity of a patient P. The disposable set 40 includes a drain line 56 that extends from a drain line port of the cassette 42 and terminates at a drain line connector 58. Figure 1 The drain line 56 is also shown that extends along a length of the circulator 20 so that at least a portion of a flow path isolator 250 (multiple versions of which are described below) can be located at the circulator 20 and operable with the drain line 56. Figure 1 The drain line connector 58 is also shown removably connected to a drain portion connector 218 of the water purifier 210.

[0109] Figure 1 and Figure 2 The disposable set 40 is further shown to include a heater / mix line 60 that extends from a heater / mix line port of the cassette 42 and terminates at a heater / mix bag 62. The disposable set 40 includes an upstream water line segment 64a that extends to a water inlet leg 92 of a Y-connector 90 (or T-connector, etc.) located just upstream of a water reservoir 66. The Y-connector 90 is connected via a leg 94 to the water reservoir 66. A downstream water line segment 64b extends from a water outlet leg 96 of the Y-connector 90 to the cassette 42. In the embodiment shown, the upstream water line segment 64a begins at a water line connector 68 and is located upstream of the water reservoir 66. Figure 1 The water line connector 68 is shown removably connected to a water outlet connector 228 of the water purifier 210.

[0110] The water purifier 210 outputs water and possibly water suitable for peritoneal dialysis ("WFPD"). However, to ensure WFPD, a sterilizing grade filter 100a is placed upstream of a downstream sterilizing grade filter 100b, respectively. In one embodiment, the water purifier 210 outputs deionized water, which is particularly important for one of the flow path isolators described below.

[0111] Figure 2 A final bag or sample line 72 is also shown that extends from a final bag or sample port of the cassette 42 and terminates at a connector 74 that can be connected to a mating connector of a premixed final fill bag of dialysis fluid or to a sample bag or other sample collection container.

[0112] Figure 1 andFigure 2 The disposable set 40 is shown to include a first (e.g., glucose) concentrate line 76 that terminates at a connector 80a. A second (e.g., buffer) concentrate line 78 terminates at a second (e.g., buffer) cartridge concentrate connector 82a. A first concentrate container 84a contains a first (e.g., glucose) concentrate that is pumped through a container line 86 to a first container concentrate connector 80b that mates with the first cartridge concentrate connector 80a. A second concentrate container 84b contains a second (e.g., buffer) concentrate that is pumped through a container line 88 to a second container concentrate connector 82b that mates with the second cartridge concentrate connector 82a.

[0113] For the disposable set 40, the rigid portion of the cartridge 42 can be made of, for example, a thermoplastic polyolefin (“TOPAS”) cyclic olefin copolymer (“coc”) in an amorphous structure. The flexible membrane of the cartridge 42 can be made of, for example, a co-polyester ether (“PCCE”), and can be one or more layers. Any tubing or lines and Y-connector 90 can be made of, for example, polyvinyl chloride (“PVC”). Any connectors can be made of, for example, acrylonitrile-butadiene-styrene (“ABS”, e.g., for the Y-connector 90 (alternatively), for the connectors 70 of the heater / mix container or bag 62, and / or for the concentrate connectors 80a, 80b, 82a, 82b discussed below), acrylic (e.g., for the drain line connector 58), or PVC (e.g., for the water line connector water line connector 68). Any bag or container, such as the heater / mix container or bag 62 discussed below, can be made of PVC. The materials used for any of the above components can change over time. Further, any of the materials discussed above can be used in any of the flow path isolators 250 described herein.

[0114] The control unit 22 can be programmed to cause the cycler 20 to perform one or more mixing actions to help properly and uniformly mix the dialysis fluid for treatment. Mixing is performed at the pump chamber 44 of the cartridge 42 and / or in the heater / mix container or bag 62.

[0115] The flow path isolators 250 (referenced to any one or more or all of the isolators 250a-250l) described in detail below can be located within the water purifier 210, which connects to the drain connector 218 and separates the disposable set drain line 56 from the water purifier drain line 214, as shown in Figure 1 The flow path isolators 250 (referenced to any one or more or all of the isolators 250a-250l) can instead be located within the cycler 20 and can operate with the drain line 56, as shown in Figure 1The flow path isolators 250 (referenced collectively as any one or more or all of the isolators 250a-2501) can further alternatively be positioned along the drain line 56 of the disposable set 40, for example, at its end portions, as shown in Figure 2 Further alternatively, different portions of the flow path isolators 250 can be located at multiple locations in the purifier 210, the circulator 20, and / or the drain line 56.

[0116] In an alternative embodiment, the water purifier 210, the first and second concentrate containers 84a and 84b, and the corresponding concentrate lines 86 and 88, and the reservoir 66 and water line segments 64a and 64b including sterilizing grade filters 100a and 100b are not provided. Instead, a prefabricated and pre-sterilized fresh dialysis fluid container or bag (not shown) is placed in fluid communication with the top three ports of the disposable cassette 42, which was previously in fluid communication with the containers 84a and 84b and the reservoir 66. In this alternative embodiment, the flow path isolators 250 (referenced collectively as any one or more or all of the isolators 250a-2501) described in detail below are located (i) within the circulator 20 and operable with the drain line 56, as shown in Figure 1 or (ii) positioned along the drain line 56 of the disposable set 40, for example, at its end portions, as shown in Figure 2 Further alternatively, different portions of the isolators 250 can be located at the circulator 20 and / or the drain line 56.

[0117] In another alternative embodiment, the water purifier 210, the first and second concentrate containers 84a and 84b, and the corresponding concentrate lines 86 and 88, and the reservoir 66 and water line segments 64a and 64b including sterilizing grade filters 100a and 100b are not provided. Instead, a dialysis fluid preparation unit is provided that mixes purified water (e.g., WFPD) with one or more concentrates (e.g., PD concentrates) to produce fresh dialysis fluid (e.g., fresh PD fluid). The drain line 56 can extend from the circulator 20 to the dialysis fluid preparation unit in a similar manner as shown in Figure 1 Here, the flow path isolators 250 (referenced collectively as any one or more or all of the isolators 250a-2501) can be located (i) within the dialysis fluid preparation unit, connected to the drain connector and separating the disposable set drain line 56 from the dialysis fluid preparation unit drain line, (ii) within the circulator 20 and operable with the drain line 56, as shown in Figure 1 or (iii) positioned along the drain line 56 of the disposable set 40, for example, at its end portions, as shown in Figure 2Further alternatively, different portions of the flow path isolator 250 can be located at multiple locations in the dialysis fluid preparation device, the circulator 20, and / or the drain line 56.

[0118] It is also contemplated to provide a peritoneal dialysis machine (not shown, e.g., a single housing) that performs each of (i) water purification, (ii) peritoneal dialysis fluid mixing using purified water and one or more concentrates, and (iii) treatment, delivering fresh peritoneal dialysis fluid to a patient, allowing the fluid to reside in the patient, and removing used dialysis fluid and patient ultrafiltrate from the patient when the residence is complete. Here, any one or more of the flow path isolators 250a-l can be provided at the all-in-one machine along the drain line 56 leading therefrom, or some at the all-in-one machine and some along the drain line.

[0119] Flow Path Isolator

[0120] The flow path isolators 250 shown herein can include one or more drain fluid collection regions, e.g., chambers. The collection regions or chambers can be reusable or disposable, and can be made of any suitable metal or polymer. If metal, the collection regions or chambers can be stainless steel, steel, or aluminum. If polymer or plastic, the collection regions or chambers can be made of any of the polymers or plastics listed above. The tubing extending to or between the collection regions or chambers can likewise be reusable or disposable, and can be made of any suitable metal or polymer. If metal, the tubing can be stainless steel. If polymer or plastic, the tubing can be made of any of the polymers or plastics listed above. It should also be noted that in any of the figures below, dashed lines leading from components indicate that those components are under the control of the control unit 22 of the circulator 20 or the control unit 212 of the water purifier 210. Figures 3-14

[0121] Reference is now made to Figure 3 In the first flow path isolator embodiment, the peritoneal dialysis system 10 provides a flow path isolator 250a that includes a first pump 252a positioned and arranged to pump used dialysis fluid through the drain line 56 to a first chamber 254a, and a second pump 252b positioned and arranged to pump used dialysis fluid from an outlet 256 of the first chamber 254a to a second chamber 254b. The separation of the drain line 56 from the first chamber 254a, the separation of the outlet 256 from the second chamber 254b, and the separation of the first chamber 254a and the second chamber 254b from each other creates a flow segment 156.

[0122] ​The first and second pumps 252a and 252b can be of the same or different types as each other and as the main pump 44 of the cycler 20 and can be, for example, peristaltic or gear pumps operating with the drain line 56. In one embodiment, the first pump 252a is the main pump 44 of the cycler 20. In various implementations of the first embodiment, (i) the first and second pumps 252a and 252b and the first and second chambers 254a and 254b are each provided at the cycler 20; (ii) the first and second pumps 252a and 252b and the first chamber 254a are provided at the cycler 20, while the second chamber 254b is provided along the drain line 56, at the dialysis fluid preparation unit, or at the water purifier 210; (iii) the first pump 252a is provided at the cycler 20, while the second pump 252b and the first and second chambers 254a and 254b are provided along the drain line 56, at the dialysis fluid preparation unit, or at the water purifier 210; or (iv) the first and second pumps 252a and 252b and the first and second chambers 254a and 254b are each provided along the drain line 56, at the dialysis fluid preparation unit, or at the water purifier 210. The second chamber 254b can output to the common drain line 56 or the water purifier drain line 214, as appropriate, as shown in FIGS. 2 and 3. Figure 3

[0123] In various implementations, the first and second chambers 254a and 254b can be cylindrical or have an elliptical shape. The first and second chambers 254a and 254b can form a volume of, for example, from 20 milliliters (“ml”) to 200 ml. The outlet 256 can have the same diameter as the drain line, for example, eight millimeters (“mm”), or a larger or smaller diameter to allow for larger or restricted flow rates as desired. The outlet lines 258a and 258b from the respective pumps 252a and 252b can extend and attach to the top of the chambers 254a and 254b (not shown and possibly not provided), but as shown, do not extend into the fluid level maintained within the chambers 254a and 254b in order to allow for the formation of the flow segment 156. To this end, a level sensor (not shown, e.g., a capacitive or optical sensor) can be provided (e.g., in or along one or more of the cycler 20, the drain line 56, the dialysis preparation unit, or the water purifier 210) to ensure that the desired drain fluid level is maintained in the chambers 254a and 254b.

[0124] ​The first and second pumps 252a and 252b are operated under the control of the control unit 22 or 212 to maintain a desired drain fluid level in the chambers 254a and 254b. The pumps 252a and 252b can also be stopped and started on some desired periodic basis to help create the flow segment 156. Additionally or alternatively, the control unit 22 or 212 operates the first and second pumps 252a and 252b in two alternating states, where (i) the pump 252a is run while the pump 252b is stopped, creating an air gap between the outlet of the conduit 258b and the fluid surface in the second chamber 254b, while the chamber 254b relies on gravity to drain, and (ii) the pump 252a is stopped while the pump 252b is run to empty the chamber 254a into the chamber 254b, while the chamber 254b continues to drain, creating an air gap between the outlet of the conduit 258a and the fluid surface in the first chamber 254a. Assuming the flow path isolator 250a is operated to prevent the chamber 254b from being completely emptied, this sequence guarantees a constant air gap and a constant drain from the chamber 254b at all times.

[0125] Reference is now made to Figure 4 In the second flow path isolator embodiment, the peritoneal dialysis system 10 provides a flow path isolator 250b that includes a first valve 272a operable with a first fluid line 274a and a second valve 272b operable with a second fluid line 274b. The first and second fluid lines 274a and 274b lead to a chamber 276. The system 10 operating the flow path isolator 250b is configured to sequentially operate the first and second valves 272a and 272b to create the flow segment 156. Figure 4 It is also shown that the flow path isolator 250b optionally (dashed line) includes a pump 278 positioned and arranged to pump used dialysis fluid from an outlet 280 of the chamber 276 to a second chamber 282.

[0126] Valves 272a and 272b and pump 278 can be of the same or different type as the valves and main pump 44 of circulator 20. Pump 278 can be, for example, a peristaltic or gear pump operating with discharge line 280. In various implementations of the second embodiment, (i) first and second valves 272a and 272b, pump 278, and first and second chambers 276 and 282 are each provided at circulator 20; (ii) first and second valves 272a and 272b and first chamber 276 are provided at circulator 20, while pump 278 and second chamber 282 are provided along discharge line 56, at the dialysis fluid preparation unit, or at water purifier 210; (iii) first and second valves 272a and 272b are provided at circulator 20, while pump 278 and first and second chambers 276 and 282 are provided along discharge line 56, at the dialysis fluid preparation unit, or at water purifier 210; or (iv) first and second valves 272a and 272b, pump 278, and first and second chambers 276 and 282 are each provided along discharge line 56, at the dialysis fluid preparation unit, or at water purifier 210. Line 284 or chamber 282 can output to general discharge line 56 or water purifier discharge line 214, respectively, as Figure 4

[0127] In various implementations, first and second chambers 276 and 282 can have any of the structures, functions, and alternatives discussed above for first and second chambers 254a and 254b of flow path isolator 250a. Lines 274a and 274b extend from discharge line 56 (and thus can be of the same dimensions) and can extend and attach to the top of chambers 276 (not shown and possibly not provided), but are shown not to extend into the fluid level held within chambers 276, so as to allow flow segments 156 to be formed. The same applies to outlet line 284 from optional pump 278. To this end, a level sensor (not shown, e.g., a capacitive or optical sensor) can be provided (e.g., in or along one or more of circulator 20, discharge line 56, the dialysis preparation unit, or water purifier 210) to ensure that the desired discharge fluid level is maintained in chambers 276 and 282.

[0128] First and second valves 272a and 272b are operated in sequence, under control of control unit 22 or 212, to produce flow segments 156 extending from lines 274a and 274b, respectively, while allowing the discharge flow rate to be relatively constant. Pump 278 is operated to maintain the desired discharge fluid level in chamber 282. Pump 278 can also be stopped and started on some desired periodic basis to help or additionally produce flow segments 156.

[0129] ​In an alternative embodiment of 250b, only a single valve (e.g., valve 272a) is provided, and control unit 22 or 212 operates valve 272a and pump 278 in two alternating states, where (i) valve 272a is opened while pump 278 is stopped, creating an air gap between pump 278 and second chamber 282, while chamber 282 is emptied, or (ii) valve 272a is closed while pump 278 is run to empty first chamber 276 into second chamber 282, while second chamber 282 continues to drain, creating an air gap between valve 272a and first chamber 276. Assuming that flow path isolator 250b is operated to prevent chamber 282 from being completely emptied, this sequence guarantees that an air gap and constant drain from chamber 282 always exists.

[0130] Reference is now made to Figure 5 In a third flow path isolator embodiment, peritoneal dialysis system 10 provides a flow path isolator 250c that includes a first pump 292a positioned and arranged to pump used dialysis fluid through drain line 56 and a second pump 292b positioned and arranged to introduce air or water along an air or water line 294 into drain line 56, creating an air or water section 296 that separates used dialysis fluid or effluent into flow section 156. Thus, air or water line 294 is drawn from a water source, such as water purifier 210 or a water tank, or from an air source, e.g., from ambient air separated by a hydrophobic filter that purifies air introduced into drain line 56. Air or water line 294 can be the same size and material as drain line 56.

[0131] In various embodiments of flow path isolator 250c, drain fluid pump 292a is provided at cycler 20 and is one of the cycler's main fluid pumps 44. Here, second (water or air) pump 292b can also be provided at cycler 20, or alongside water purifier 210, dialysis fluid preparation unit, or along drain line 56. In alternative embodiments, fluid pump 292a is provided at water purifier 210, dialysis fluid preparation unit, or along drain line 56. If air is introduced into line 194, pump 292b can be an air pump that pumps purified air into drain line 56. If water is introduced into line 194, pump 292b can be a peristaltic or gear pump.

[0132] The first and second pumps 292a and 292b are operated under the control of the control unit 22 or 212 to produce alternating segments of a slug of used dialysis fluid with a slug 296 of water or air to produce the flow segments 156. The changeover is performed at a desired frequency to produce segments of a desired length. If water is used, the water is deionized so that the water is not conductive, producing non-conductive segments. The water can be deionized via a separate deionization device such as one involving a deionization filter, a capacitive deionization mechanism, or an electro-deionization mechanism. Alternatively, the deionization process can be provided as part of the water purifier 210.

[0133] Reference is now made to Figure 6 In a fourth flow path isolator embodiment, the peritoneal dialysis system 10 provides a flow path isolator 250d that includes a coiled tubing 310 configured to produce a length of flow segments 156. The length of coiled tubing 310 can be disposable and located downstream of the cycler 20 along the drain line 56, or reusable and located, for example, inside the cycler 20, inside the water purifier 210, or inside a dialysate preparation unit. The ratio of the length (L) of the coil 310 to the cross-sectional area (A) of the coil 310 is, for example, 10,000:8 (e.g., 10 m of 8 mm internal diameter tubing), selected so that the electrical resistance within the coil 310 reduces any leakage current through the patient line 50 and drain line 56 to an insignificant or safe level. The coil can also naturally create an air pocket in the drain fluid, producing flow segments 156 as shown.

[0134] Figure 6 A coiled tubing 310 is shown disposed vertically. Here, the effluent flow can be from top to bottom or from bottom to top. Alternatively, the coiled tubing 310 can be disposed horizontally or at an angle.

[0135] Reference is now made to Figure 7In a fifth flow path isolator embodiment, peritoneal dialysis system 10 provides a flow path isolator 250e that includes a peristaltic pump 322 configured to create flow segments 156. Rotors 324 extending to rollers 326 are configured to completely occlude drain line tubing segment 328 against a seat 330 in one or more locations to form segments 156. Rollers 326 can be spring loaded via springs 332 to help ensure that drain line tubing segment 328 is completely occluded against seat 330. The number of rollers 326 can also be increased as shown to create additional effluent segments 156. Peristaltic pump 322 can be located at cycler 20, positioned along drain line 56, at water purifier 210 (e.g., enter tubing segment 328 via common drain line 56 and exit chamber 346 via water purifier drain line 214), or at a dialysis fluid preparation unit. Tubing segment 328 can be reusable or disposable.

[0136] Referring now to Figure 8 In a sixth flow path isolator embodiment, peritoneal dialysis system 10 provides a flow path isolator 250f that includes a pump 342 that pumps effluent along drain line 56 to an aspirator 344 configured to create flow segments 156. A chamber 346 is provided and configured to collect flow segments 156 from aspirator 344. Aspirator 344 in the illustrated embodiment is provided in the form of a nozzle having a plurality of openings that create a spray or mist of flow segments 156. Chamber 346 can have any of the structures, functions, and alternatives discussed above for first and second chambers 254a, 254b of flow path isolator 250a.

[0137] Pump 342 can be one of the main pumps 44 of cycler 20 and can be a peristaltic pump or a gear pump. In various implementations of flow path isolator 250f, (i) pump 342, aspirator 344, and chamber 346 are each provided at cycler 20; (ii) pump 342 is provided at cycler 20 while aspirator 344 and chamber 346 are provided at water purifier 210 (e.g., enter pump 342 via common drain line 56 and exit chamber 346 via water purifier drain line 214), at a dialysis fluid preparation unit, or along drain line 56; or (iii) pump 342, aspirator 344, and chamber 346 are each provided at water purifier 210, at a dialysis fluid preparation unit, or along drain line 56.

[0138] It should be appreciated that flow segments 156 can vary in size. Flow segments 156 can be (i) very small in size or diameter (e.g., size of mist particles for aspirator flow path isolator 250f), (ii) a relatively large segment of used dialysis fluid, e.g., as shown in FIG. 6, (iii) a relatively small segment of used dialysis fluid, e.g., as shown in FIG. 7, or (iv) a combination of (i) and (ii) or (i) and (iii).Figure 5 like the isolator 250c, or (iii) a chamber that is the same size as the chambers of the isolators 250a and 250b.

[0139] Reference is now made to Figure 9 In the seventh flow path isolator embodiment, the peritoneal dialysis system 10 provides a flow path isolator 250g that includes siphons 352 and 358 configured to create a flow segment. The first siphon 352 in the illustrated embodiment includes a siphon tube 354 and a siphon chamber 356. The second siphon 358 includes a second siphon tube 360 and a second siphon chamber 362. The first siphon 352 outputs to the second siphon 358 in such a way that the siphon tube 354 does not contact the fluid level present in the second chamber 362 of the second siphon 358, which can create a flow segment 156. The bottom of the first siphon tube 354 can be attached to the top of the second siphon chamber 362 (not shown), but does not extend through the top or far enough to contact the liquid level therein. In a similar manner, the drain line 56 does not contact the fluid level within the first siphon chamber 356, which can create a flow segment 156.

[0140] The siphons 352 and 358 can be reusable or disposable. The siphon chambers 356 and 362 can include any of the structures, functions, and alternatives discussed above for the first and second chambers 254a and 254b of the flow path isolator 250a. The siphon tubes 354 and 360 can be rigid or flexible and made of any of the metals or polymers discussed herein. In various embodiments, the siphons 352 and 358 can be located within the cycler 20, within the water purifier 210 (e.g., into the chamber 356 via the common drain line 56 and out of the chamber 362 via the water purifier drain line 214), within the dialysis fluid preparation unit, or positioned along the drain line 56.

[0141] The siphon tubes 354 and 360 and the siphon chambers 356 and 362 are sized such that the siphons 352 and 358 create a discontinuous flow. Initially, when the siphon chambers 356 and 362 begin to fill, e.g., via the main pump 44 of the cycler 20, no flow exits the siphon tubes 354 and 360. When the discharge pressure of the effluent within the siphon chambers 356 and 362 increases to a threshold level, the effluent flows out of the siphon tubes 354 and 360.

[0142] In one embodiment, the first siphon 352 and the second siphon 358 operate in a first state and a second state. In the first state, effluent flows from the circulator 20 to the chamber 356 of the first siphon 352, filling the first siphon chamber 356, establishing a discharge pressure, while the second siphon chamber 362 is vented, losing discharge pressure. Here, there is an effluent air gap between the first siphon chamber 356 and the second siphon chamber 362. In the second state, effluent still flows from the circulator 20 to the chamber 356 of the first siphon 352, but here, the first siphon chamber 356 is vented, losing discharge pressure, while no siphoning occurs in the chamber 362 of the second siphon 358 because the fluid level in the chamber 362 has dropped at least below the highest point of the outlet 360, interrupting siphoning. In the second state, there is an effluent gap between the chamber 362 of the second siphon 358 and the housing vent. In one embodiment, to produce the first state and the second state, (i) the first siphon 352 is configured to discharge at a flow rate greater than the effluent flow rate from the circulator 20 to the first siphon, and (ii) the first siphon 352 and the second siphon 358 are configured such that their switching states between the first siphon 352 establishing discharge pressure and losing discharge pressure and the second siphon 358 losing discharge pressure and establishing discharge pressure occur simultaneously or substantially simultaneously, or vice versa.

[0143] Referring now to Figure 10 In the eighth flow path isolator embodiment, the peritoneal dialysis system 10 provides a flow path isolator 250h that includes a valve 372 that selectively allows effluent to flow through a first chamber 374, e.g., via the main pump 44 of the circulator 20, to create the flow segment 156, the first chamber having an output line 376 that points to but is separate from a second chamber 380. The first chamber 374 outputs to the second chamber 380 via the line 376 and a second valve 378 in a manner such that the output line 376 does not contact the fluid level present in the second chamber 380. The valves 372 and 378 can be switched to create the flow segment 156. In other words, the bottom of the output line 376 can be attached to the top of the second chamber 380 (not shown), but not extend through the top or far enough to contact the liquid level therein. In a similar manner, the vent line 56 does not contact the fluid level within the first chamber 374, further creating the flow segment 156. The valve 372 can also be switched open and closed to help create the discontinuous flow.

[0144] The first and second chambers 374 and 380 can have any of the structures, functions, and alternatives discussed above for the first and second chambers 254a and 254b of the flow path isolator 250a. In various embodiments of the flow path isolator 250h, (i) the valves 372 and 378, the first chamber 374, and the second chamber 380 are each located at the circulator 20; (ii) the valves 372 and 378 and the first chamber 374 are located at the circulator 20, while the second chamber 380 is located at the water purifier 210 (e.g., effluent enters the first chamber 374 via the general drain line 56 and exits the second chamber 380 via the water purifier drain line 214), at the dialysis fluid preparation unit, or positioned along the drain line 56; (iii) the valve 372 is located at the circulator 20, while the first chamber 374, the second valve 378, and the second chamber 380 are located at the water purifier 210, at the dialysis fluid preparation unit, or positioned along the drain line 56; or (iv) the valves 372 and 378, the first chamber 374, and the second chamber 380 are each located at the water purifier 210, at the dialysis fluid preparation unit, or positioned along the drain line 56.

[0145] Additionally or alternatively, the control unit 22 or 212 operates the first and second valves 372 and 378 in two alternating states, where (i) the valve 372 is opened while the valve 378 is closed, creating an air gap between the chamber 374 and the chamber 380, while the chamber 380 is relied upon for gravity drainage, or (ii) the valve 372 is closed while the valve 378 is opened to evacuate the chamber 374 into the chamber 380, while the chamber 380 continues to drain, creating an air gap between the valve 372 and the first chamber 374. Assuming the flow path isolator 250h is operated to prevent the second chamber 380 from being completely evacuated, this sequence guarantees an air gap and constant drain from the second chamber 380.

[0146] Reference is now made to Figure 11 In a ninth flow path isolator embodiment, the peritoneal dialysis system 10 provides a flow path isolator 250i that includes a first chamber 390 that receives effluent from the drain line 56. The first chamber 390 is hinged along a hinge 392 located at the bottom of the first chamber 390. The first chamber 390 is configured to rest in an upright position Figure 11 shown, only under its own weight after tilting and delivering dialysis fluid to the siphon 400. The first chamber 390 can also be counterweighted so that it returns Figure 11 shown, only under its own weight after tilting and delivering dialysis fluid to the siphon 400. The first chamber 390 can also be counterweighted so that it returns Figure 11 shown, only under its own weight after tilting and delivering dialysis fluid to the siphon 400. The first chamber 390 can also be counterweighted so that it returns

[0147] The flow path isolator 250i also includes a siphon portion 400. The siphon portion 400 in the illustrated embodiment includes a siphon tube 402 and a siphon chamber 404. The siphon portion 400 outputs to the drain line 62 or 214. The chamber 390 and the siphon portion 400 can be reusable or disposable. The chamber 390 and the siphon chamber 404 can include any of the structures, functions, and alternatives discussed above for the first and second chambers 254a, 254b of the flow path isolator 250a. The siphon tube 402 can be rigid or flexible and made of any of the metals or polymers discussed herein. In various embodiments, the chamber 390 and the siphon portion 400 can be located within the cycler 20, within the water purifier 210 (e.g., into the chamber 390 via the common drain line 56 and out of the siphon chamber 404 via the water purifier drain line 214), within a dialysis fluid preparation unit, and / or positioned along the drain line 56.

[0148] In operation, the chamber 390 fills with effluent while effluent drains from the siphon chamber 404 to the housing drain. Here, an air gap is created between the rotatable chamber 390 and the siphon chamber 404. At some point before the rotatable chamber 390 tilts, the drain pressure within the siphon chamber 404 drops to a point such that effluent no longer drains from the siphon chamber 404, creating an air gap between the siphon chamber 404 and the housing drain. When the weight of the effluent becomes large enough to overcome the force of the counterweight of the chamber 390 and / or the biasing device 394, the rotatable chamber 390 tilts and rotates about the hinge 392. Effluent is rapidly released from the chamber 390 into the siphon chamber 404.

[0149] Although not shown, when the rotatable chamber 390 tilts, an electrical contact located between the bottom of the chamber 390 and the top of the stop 396 breaks, which triggers the control unit 22 of the cycler 20 to temporarily stop the fluid pump chamber 44 during current consumption so that effluent does not spill out from the outside perimeter of the chamber 390. If the flow path isolator 250i is located, for example, within the water purifier 210, the trigger due to the breaking of the electrical contact causes the control unit 212 of the water purifier 210 to send a signal wired or wirelessly to the control unit 22 of the cycler 20, which then temporarily stops the pump chamber 44. The point contact can alternatively be any type of switch that switches from a first state to a second state when the chamber 390 is tilted and returns to the first state when the chamber 390 is returned to its upright position.

[0150] The transfer of effluent from the chamber 390 to the siphon chamber 404 occurs rapidly, such that the interruption of the associated drain flow is short. Once the weight of effluent is removed from the rotatable chamber 390, the chamber 390 rotates under its own weight (and / or with the aid of a biasing device 394, e.g., a spring) about the hinge 392 back into its upright position, reestablishing electrical contact with the lead or electrode located on the stop 396, which in turn triggers the control unit 22 to resume actuation of the pump chamber 44 to continue current draw. After filling by effluent from the rotatable chamber 390, the siphon chamber 404 has the necessary drain pressure to expel effluent to the housing drain.

[0151] Reference is now made to Figure 12 In a tenth flow path isolator embodiment, the peritoneal dialysis system 10 provides a flow path isolator 250j that includes a container or bag 410 positioned along the drain line 56 upstream of a valve 414 that allows or does not allow effluent flow to a first chamber 416a. A pressure sensor 412 is positioned to read the pressure within the container or bag 410 and output a signal corresponding to that pressure to one or both of the control unit 22 or the control unit 212. The first chamber 416a is separated from a second chamber 416b by a first pump 418a. In various embodiments, the first and second chambers 416a, 416b can have any of the structures, functions, and alternatives discussed above for the first and second chambers 254a, 254b of the flow path isolator 250a.

[0152] A second pump 418b is downstream of the second chamber 416b. The first and second pumps 418a, 418b can be of the same or different types as each other and as the main pump 44 of the circulator 20, and can be, for example, peristaltic or gear pumps operating with the drain line 56. In one embodiment, the first pump 418a comprises the main pump 44 of the circulator 20. In various implementations of the first embodiment, (i) the first and second pumps 418a, 418b and the first and second chambers 416a, 416b are each provided at the circulator 20; (ii) the first and second chambers 416a, 416b and the first pump 252a are provided at the circulator 20, while the second pump 418b is provided along the drain line 56, at the dialysis fluid preparation unit, or at the water purifier 210; (iii) the first chamber 416a is provided at the circulator 20, while the second chamber 416b and the first and second pumps 418a, 418b are provided along the drain line 56, at the dialysis fluid preparation unit, or at the water purifier 210; or (iv) the first and second pumps 418a, 418b and the first and second chambers 416a, 416b are each provided along the drain line 56, at the dialysis fluid preparation unit, or at the water purifier 210. The second pump 418b can output to the general drain line 56 or the water purifier drain line 214, as appropriate, as shown in Figure 12

[0153] In one embodiment, operation of the flow path isolator 250j includes operating the circulator 20 to circulate dialysis fluid from the first chamber 416a through the first pump 418a, through the second pump 418b, and through the second chamber 416b, as shown in Figure 1 ​The patient P is drained into the container or bag 410 while the valve 414 is held in a closed or no flow state. At the same time, the first pump 418a pumps fluid from the first chamber 416a to the second chamber 416b without actuating the second pump 418b. When the effluent level in the first chamber 416a drops below a certain threshold level (this condition is determined, for example, (i) as measured by a level or weight sensor (not shown) output to the at least one control unit 22 or 212, and / or (ii) by monitoring how much effluent has been removed from the first chamber 416a), the first pump 418a is stopped, for example, slightly before the valve 414 is opened (to ensure no delay in electrical contact with the ground), and the first chamber 416a is filled from the container or bag 410, for example, by gravity. The second pump 418b is then actuated to pump effluent from the second chamber 416b to the housing drain via the drain line 56 or 214. When the level of effluent in the first chamber 416a reaches an upper threshold (this condition is determined, for example, via a level sensor, a weight sensor, and / or volume monitoring), the valve 414 is closed, the second pump 418b is stopped, and the above cycle is repeated, with the first pump 418a emptying effluent from the first chamber 416a into the second chamber 416b. The above sequence ensures that there is always an air gap between the patient P and the housing drain 56 (either the second pump 418b or the first pump 416a is stopped).

[0154] At any time when the valve 414 is closed, the pump 44 of the cycler 20 can be used to refill the container or bag 410 with effluent. In one embodiment, the pump 44 of the cycler 20 operates at a flow rate prescribed for the patient. The pumps 418a and 418b operate at a flow rate sufficient to ensure that the first chamber 416a and the second chamber 416b, respectively, do not overflow. The pressure sensor 412 ensures that the container or bag 410 does not become over-pressurized. The pressure sensor 412 can also be used by the control unit 22 or 212 to know when to open the valve 414 in the above sequence.

[0155] Referring now to Figure 13A and Figure 13B In an eleventh flow path isolator embodiment, the peritoneal dialysis system 10 provides a flow path isolator 250k. The flow path isolator 250k takes advantage of the different stages involved in peritoneal dialysis (i.e., drain, fill, and dwell stages). With the flow path isolator 250k, while the cycler 20 performs a complete drain and stores the effluent until the drain stage is complete, the cycler 20, the water purifier 210, the dialysis fluid preparation unit, or other pumps remove the effluent to the housing drain during the fill and / or dwell stages. In particular, Figure 13A and Figure 13BA chamber 430 is shown disposed along the drain line, disposed at the circulator 20 along the drain line 56 between the circulator and the housing drain, disposed at the water purifier 210, or disposed at the dialysis fluid preparation unit. A drain container or bag 432 is placed in fluid communication with the chamber 430. The drain container or bag 432 can hold three liters of effluent, or it is large enough to hold the entire drain volume from the patient P, including the associated ultrafiltration volume. In various embodiments, the chamber 430 is reusable and made of any of the materials described herein, while the drain container or bag 432 is disposable and made of any of the materials described herein.

[0156] In the illustrated embodiment, valves 434a and 434b are disposed upstream and downstream, respectively, of the chamber 430. A third valve 434c can be disposed as an air vent valve. A pump 436 is disposed downstream of the valve 434b (but can also be disposed upstream of the valve), and can be any of the types of pumps discussed herein. The valves 434a-c and pump 436 can be disposed at the circulator 20, along the drain line 56 between the circulator and the housing drain, disposed at the water purifier 210, or disposed at the dialysis fluid preparation unit. If disposed at the water purifier 210, the drain line 56 outputs to the water purifier drain line 214.

[0157] Figure 13A During the drain phase, the valve 434a is shown open while the valves 434b and 434c are closed. The pump 436 is not operated. Effluent is pumped into the chamber 430 and from the chamber into the drain container or bag 432. An air gap is maintained between the point at which effluent enters the chamber 430 and the chamber level.

[0158] Figure 13B After the drain phase, during the fill and / or dwell phase, the valve 434b is shown open while the valves 434a and 434c are closed. As shown, the chamber 430 includes a partition that forces effluent on the inlet side of the partition to flow down below the partition before being pulled out of the outlet side of the chamber via the pump 436, thereby maintaining an air gap. Upon closing the valve 434a, the pump 436 pulls effluent from the container or bag 432 to the housing drain. Both the air gap and the closed valve 434a ensure that no electrical current can flow between the patient P and the housing drain.

[0159] Reference is now made to Figure 14 In a twelfth flow path isolator embodiment, the peritoneal dialysis system 10 provides a flow path isolator 2501. Figure 14Chambers 450 and 452 are shown disposed along the drain line, at the circulator 20 along the drain line 56 between the circulator 20 and the housing drain, at the water purifier 210, or at the dialysis fluid preparation unit. Chambers 450 and 452 can be reusable and made of any of the materials described herein. Chambers 450 and 452 each include a partition 454 as described above for chamber 430 that forces effluent entering the chamber down below the partition and then up and out of the outlet of the chamber. Chambers 450 and 452 operate in parallel with each other as discussed below and interface between the inlet drain line 56 and a pump 456, which can be any of the types of pumps discussed herein.

[0160] Flow path isolator 2501 includes six valves including inlet valves 458a and 458b, outlet valves 460a and 460b, and vent valve 462a and tank valve 462b. Inlet valves 458a and outlet valve 460b form a first parallel path, while inlet valve 458b and outlet valve 460a form a second parallel path. Inlet valve 458a leads to chamber 450, while inlet valve 458b leads to chamber 452. Outlet valve 460a extends from chamber 450, while outlet valve 460b extends from chamber 452. Vent valve 462a is operated to vent chambers 450 and 452 when filling. Tank valve 462b is used at the end of the emptying phase to thereafter equalize the level in the two halves of the chamber being emptied.

[0161] In operation, control unit 22 or 212 sequentially operates the valves of one parallel path to fill one of chambers 450 or 452 while emptying the other chamber to the housing drain. In the first parallel path, inlet valve 458a is opened to allow circulator pump 44 to push effluent into chamber 450, while inlet valve 458b of the second parallel path is closed. At the same time, outlet valve 460b of the second parallel path is opened to allow pump 456 to pump effluent from chamber 452 to the housing drain, while outlet valve 460a of the first parallel path is closed. Figure 14 In operation, control unit 22 or 212 sequentially operates the valves of one parallel path to fill one of chambers 450 or 452 while emptying the other chamber to the housing drain. In the first parallel path, inlet valve 458a is opened to allow circulator pump 44 to push effluent into chamber 450, while inlet valve 458b of the second parallel path is closed. At the same time, outlet valve 460b of the second parallel path is opened to allow pump 456 to pump effluent from chamber 452 to the housing drain, while outlet valve 460a of the first parallel path is closed.

[0162] The level of effluent in each chamber 450 and 452 is known via at least one of (i) one or more level sensors operating with each chamber and outputting to at least one of the control units 22 or 212, (ii) a weigh scale operating with each chamber and outputting to at least one of the control units 22 or 212, and / or (iii) monitoring the volume of effluent pumped to or from the chamber, e.g., based on the accuracy of the pump, such as counting known stroke volumes. In one embodiment, the control units 22 or 212 are programmed so that the lower level limit of the drain chamber is reached at the same time as the upper level limit of the fill of the other chamber is reached. However, it can be preferable to program the control units 22 or 212 so that the drain time of the chambers 450 and 452 is shorter than the fill time.

[0163] In different embodiments, both the lower limit (drain) and the upper limit (fill) must be reached before the valve state is switched. Here, it can be desirable to run the pump 456 faster than the circulator pump 44 to ensure that the flow path isolator 2501 is always filling one of the chambers 450 or 452. In alternative embodiments, only one of the lower limit (drain) or the upper limit (fill) must be reached before the valve state is switched. Here, the fill can occur faster than the drain, where, if necessary, the circulator pump 44 can be stopped while the circulator 20 waits for the chamber 450 or 452 to empty out.

[0164] Regardless of what can trigger the valve to switch states, when the trigger is reached in Figure 14 the control unit 22 or 212 switches the inlet valve state and the outlet valve state. Here, the inlet valve 458b of the second parallel path is opened to allow the circulator pump 44 to push effluent into the chamber 452, while the inlet valve 458a of the first parallel path is closed. At the same time, the outlet valve 460a of the first parallel path is opened to allow the pump 456 to pump effluent from the chamber 450 to the housing drain, while the outlet valve 460b of the second parallel path is closed.

[0165] An air gap exists with the flow path isolator 2501 because the fluid path extending from the circulator 20 (and the patient P) flows to one of the chambers 450 or 452, while the fluid path from the chamber to the housing drain flows from the other of the chambers 450 or 452. As shown, the chambers 450 and 452 also maintain an air gap, providing additional galvanic isolation.

[0166] Referring now to Figure 15 In a thirteenth flow path isolator embodiment, the peritoneal dialysis system 10 provides a flow path isolator 250m. Figure 15A flow path isolator 250m is shown disposed along the drain line, at the recirculator 20, disposed along the drain line 56, 214 between the recirculator 20 and the housing drain, disposed at the water purifier 210, or disposed at the dialysis fluid preparation unit. The flow path isolator 250m can be reusable and made of any of the materials described herein. The flow path isolator 250m includes a pivoting device or cradle 470 that includes compartments 472 and 474 that pivot back and forth about a pivot 476 under the weight of incoming used dialysis fluid or effluent from the drain line 56. The used dialysis fluid flows continuously along the drain line 56 and into a container 478 that is connected to or formed with the pivoting device or cradle 470 at the top of the container 478.

[0167] The compartments 472 and 474 are separated by a middle wall 480. The used dialysis fluid falling into the cradle 470 impacts or contacts one side or the other of the middle wall 480 that separates the cradle 470 into compartments 472 and 474. In Figure 15 the wall 480 that is in contact with the currently falling effluent belongs to the compartment 472 that is being filled. At the same time, the compartment 474 is emptying the used dialysis fluid into the container 478. It should be understood that in Figure 15 the illustrated state, the compartment 472 is isolated from ground at the end of the drain line 56, 214. Figure 15 the wall 480 that is not in contact with the currently falling effluent belongs to the compartment 474 that is draining into the container 478 that in turn drains to the distal end of the drain line 56, 214 and to the housing drain. If needed, a separate pump (not shown) can be provided to pump from the container 478 to the housing drain. It should be understood that Figure 15 the compartment 474 in the state of

[0168] When enough effluent enters the compartment 472 and enough effluent exits the compartment 474, the pivoting device or cradle 470 switches state and pivots about the pivot 476. At this moment, the compartment 472 is draining effluent and electrically isolated from the patient, while the compartment 474 is being filled with effluent and electrically isolated from ground. The state switching is repeated, allowing effluent to be continuously drained from the drain line 56 into the cradle 470 until the patient drain is complete.

[0169] Additional Incoming Fluid Flow

[0170] Reference is now made to Figure 16FIG. 49 shows an alternative embodiment 490 of flow path isolators 250a, 250b, 250f, 250g, 250h, 250i, 250j, and 250m. The alternative embodiment can be provided when the water purifier 210 or dialysis fluid preparation unit is installed with the flow path isolators listed above. Here, the respective outlet line 258b, outlet line 284, outlet line from pump 332, siphon 354, output line 376, rotatable chamber 390, outlet line from pump 418a, or drain line 56 lead into the second chamber 254b, chamber 282, chamber 346, chamber 362, second chamber 380, siphon chamber 404, second chamber 416b, or container 478, respectively.

[0171] Figure 16 The embodiment 490 includes additional lines to the second chamber 254b, chamber 282, chamber 346, chamber 362, second chamber 380, siphon chamber 404, second chamber 416b, or container 478, i.e., a waste line from a water purification device that can be provided with the water purification portion of the water purifier 210 or dialysis fluid preparation unit. The water purification device can be any type of device that has a waste fluid or water line. There can be any desired number of water purification devices, each having a waste line to the second chamber 254b, chamber 282, chamber 346, chamber 362, second chamber 380, siphon chamber 404, second chamber 416b, or container 478.

[0172] In the illustrated embodiment, one water purification device is a reverse osmosis unit 492 that has a fluid or water waste line 494 to the second chamber 254b, chamber 282, chamber 346, chamber 362, second chamber 380, siphon chamber 404, second chamber 416b, or container 478. Under control of the control unit 212 of the water purifier 210 or the control unit of the dialysis fluid preparation unit, waste fluid or water is selectively allowed to flow to the chambers via a valve 496 (e.g., an electrically actuated solenoid valve). The valve 496 can or can not be opened and closed sequentially to attempt to create the flow segments 156 discussed herein.

[0173] In the illustrated embodiment, another water purification device is an ultrafilter 500 that has a fluid or water waste line 502 to the second chamber 254b, chamber 282, chamber 346, chamber 362, second chamber 380, siphon chamber 404, second chamber 416b, or container 478. Under control of the control unit 212 of the water purifier 210 or the control unit of the dialysis fluid preparation unit, waste fluid or water is selectively allowed to flow to the chambers via a valve 504 (e.g., an electrically actuated solenoid valve). The valve 504 likewise can or can not be opened and closed sequentially to attempt to create the flow segments 156.

[0174] An optional valve 506 (e.g., an electrically actuated solenoid valve) can be disposed along the outlet line 258b, the outlet line 284, the outlet line from the pump 332, the siphon 354, the output line 376, the rotatable chamber 390, the outlet line from the pump 418a, or the drain line 56 under the control of the control unit 212 of the water purifier 210 or the control unit of the dialysis fluid preparation unit. The optional valve 504 can be sequentially opened and closed to attempt to create the flow segments 156 in addition to the used dialysis fluid or effluent flow separation provided by the flow path isolators 250a, 250b, 250f, 250g, 250h, 250i, 250j, and 250m.

[0175] In an alternative embodiment, the optional valve 506 is sequentially opened and closed to attempt to create the flow segments 156 instead of the flow path separation provided by the flow path isolators 250a, 250b, 250f, 250g, 250h, 250i, 250j, and 250m. Here, the sequential operation of the optional valve 506 to form the flow path segments 156 is the only mechanism to create the used dialysis fluid or effluent flow separation.

[0176] In another alternative embodiment, Figure 16 the chambers are separate additional chambers and are not the respective second chambers 254b, the chamber 282, the chamber 346, the chamber 362, the second chamber 380, the siphon chamber 404, the second chamber 416b, or the container 478 of the flow path isolators 250a, 250b, 250f, 250g, 250h, 250i, 250j, and 250m. Again, the water purification devices 492 and 500 and the associated lines 494 and 502 and valves 496 and 504 are provided. Here, the optional valve 506 can or can not be provided and, if provided, can or can not be sequentially opened and closed to attempt to create the flow segments 156. The additional chambers and the optional valve 506 in this alternative embodiment can be alternately disposed and used with the air / water injection flow path isolator 250c, the coil tubing flow path isolator 250d, the peristaltic pump flow path isolator 250e, the flow path isolator 250k, and the flow path isolator 2501.

[0177] In another alternative embodiment, Figure 16The chamber in the water purifier 210 is alternatively one or both of the first chamber 254a of the flow path isolator 250a, the first chamber 276 of the flow path isolator 250b, the first siphon chamber 356 of the flow path isolator 250g, the first chamber 374 of the flow path isolator 250h, the rotatable chamber 390 of the flow path isolator 250i, the first chamber 416a of the flow path isolator 250j, the chamber 430 of the flow path isolator 250k, or the first chamber 450 and the second chamber 452 of the flow path isolator 2501. Again, the water purifiers 492 and 500 and the associated lines 494 and 502 and valves 496 and 504 are provided. Here, the optional valve 506 can or can not be provided, and if provided, can or can not be opened and closed sequentially to attempt to create the flow segment 156.

[0178] In any of the alternative embodiments discussed above, an optional pump 508 (e.g., a peristaltic or gear pump) controlled by the control unit 212 of the water purifier 210 or the control unit of the dialysis fluid preparation unit can be provided along the drain line 214 of the water purifier 210 or a similar drain line of the dialysis fluid preparation unit, if not already provided. To empty the chamber, an optional level sensor 510 outputting to the control unit can also be provided to trigger the control unit to actuate the pump 508 when the level L of the combined used dialysis fluid and waste fluid or water rises to reach the level sensor 510.

[0179] 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. For example, while the drawings and specification generally describe a single flow path isolator 250 for each given system 10, it is contemplated that two or more flow path isolators can be provided as desired at any two or more of the recirculator 20, the water purifier 210, the dialysis fluid preparation unit, and / or along the drain line 56. Moreover, any one or more or all of the flow path isolators 250 can be operated via the control unit 22 of the recirculator 20, the control unit 212 of the water purifier 210, or a combination thereof. Such changes and modifications can be made without departing from the spirit and scope of the present application and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.

Claims

1. A peritoneal dialysis system comprising: a circulator; a disposable set comprising a patient line and a drain line, the circulator configured to pump fresh dialysis fluid to a patient via the patient line and to pump used dialysis fluid from the patient via the drain line; one of (i) a water purifier for supplying purified water for mixing to form fresh dialysis fluid at the disposable set, (ii) at least one fresh dialysis fluid container provided as part of the disposable set for supplying fresh dialysis fluid, or (iii) a dialysis fluid preparation unit configured to supply fresh dialysis fluid to the disposable set; and at least one flow path isolator provided at or alongside at least one of the circulator, the water purifier, the dialysis fluid preparation unit, or along the drain line, the flow path isolator configured to separate used dialysis fluid flowing along the drain line to limit current flow from the patient to a housing drain, wherein the flow path isolator comprises one of options a-i: a. a first valve operable with a first fluid line and a second valve operable with a second fluid line, the first and second fluid lines leading to a cavity, the system configured to operate the first and second valves in sequence to separate the used dialysis fluid to limit current flow from the patient to the housing drain; b. a first pump positioned and arranged to pump used dialysis fluid through the drain line and a second pump positioned and arranged to introduce air or water into the drain line to create a flow separation section of used dialysis fluid to limit current flow from the patient to the housing drain; c. a cavity containing used dialysis fluid, the cavity hinged via a hinge and configured to tilt via a weight of the used dialysis fluid such that the used dialysis fluid is sufficiently filled to siphon, such that a discharge pressure within the siphon causes used dialysis fluid to flow out of the siphon; d. an aspirator configured to create a flow separation section to limit current flow from the patient to the housing drain and a cavity configured to collect the flow separation section from the aspirator; e. a first siphon and a second siphon, wherein the system is configured to prevent the first siphon from creating sufficient discharge pressure for used dialysis fluid to flow from the first siphon to the second siphon until a discharge pressure in the second siphon drops such that used dialysis fluid does not flow out of the second siphon, separating used dialysis fluid flowing along the drain line to limit current flow from the patient to the housing drain; ​ f. a first chamber having an output directed toward but separate from a second chamber, a first valve upstream of the first chamber, a second valve upstream of the second chamber, the first valve and the second valve configured to operate in sequence to isolate used dialysis fluid flowing along the drain line to limit current flow from the patient to the housing drain; g. a container upstream of a first chamber, the first chamber upstream of a first pump, the first pump upstream of a second chamber, the second chamber upstream of a second pump, the first pump and the second pump configured to operate in sequence to isolate used dialysis fluid flowing along the drain line to limit current flow from the patient to the housing drain; h. a first chamber, a second chamber, and a pump downstream of the first chamber and the second chamber, a first inlet valve and a second inlet valve in fluid communication with the first chamber and the second chamber, respectively, a first outlet valve and a second outlet valve in fluid communication with the first chamber and the second chamber, respectively, the first inlet valve and the second inlet valve and the first outlet valve and the second outlet valve configured to operate in sequence such that used dialysis fluid flows into one of the first chamber and the second chamber while used dialysis fluid is removed from the other of the first chamber and the second chamber, thereby isolating used dialysis fluid flowing along the drain line to limit current flow from the patient to the housing drain; i. a pivoting device that pivots about a pivot axis, the pivoting device including a first compartment and a second compartment, the first compartment and the second compartment configured to alternately fill and drain used dialysis fluid to isolate the used dialysis fluid flowing along the drain line to limit current flow from the patient to the housing drain.

2. The peritoneal dialysis system of claim 1, wherein, For option a, the flow path isolator further includes a pump positioned and arranged to pump used dialysis fluid from an outlet of the chamber to a second chamber, the system configured to operate in sequence the first valve and the second valve and the pump to isolate the used dialysis fluid to limit current flow from the patient to the housing drain.

3. The peritoneal dialysis system of claim 1, wherein, For option b, the first pump is provided at the circulator and the second pump is provided at or beside the water purifier, the dialysis fluid preparation unit, or along the drain line.

4. The peritoneal dialysis system of claim 1, wherein, For option b, the first pump is a main pump of the circulator.

5. The peritoneal dialysis system of claim 1, wherein, For option c, the flow path isolator includes at least one of (i) a biasing device positioned and arranged to return the chamber to a fill position after tilting, or (ii) a switch that switches from a first state to a second state when the chamber is tilted to prevent used dialysis fluid from flowing to the chamber until the switch returns to the first state.

6. The peritoneal dialysis system of claim 1, wherein, For option e, the first siphon includes a first siphon tube and a first siphon chamber, and the second siphon includes a second siphon tube and a second siphon chamber.

7. The peritoneal dialysis system of claim 1, wherein, For option f, the first valve and the second valve are configured to operate sequentially, such that if the second valve is opened, used dialysis fluid is prevented from flowing to the first chamber, and the second valve is opened when the second chamber is empty.

8. The peritoneal dialysis system of claim 1, wherein, For option g, the used dialysis fluid is configured such that when used dialysis fluid flows from the second chamber, used dialysis fluid is prevented from flowing from the first chamber to the second chamber.

9. The peritoneal dialysis system of claim 1, wherein, For option h, the first inlet valve and the second inlet valve and the first outlet valve and the second outlet valve are configured to: (i) in a first state, open the first inlet valve and the second outlet valve while closing the second inlet valve and the first outlet valve, and (ii) in a second state, open the second inlet valve and the first outlet valve while closing the first inlet valve and the second outlet valve.

10. The peritoneal dialysis system of claim 1, wherein, For option h, the used dialysis fluid is delivered to the first chamber and the second chamber via a main pump of the circulator.

11. A peritoneal dialysis system, comprising: a circulator; a disposable set comprising a patient line and a drain line, the circulator being configured to pump fresh dialysis fluid to a patient via the patient line and to pump used dialysis fluid from the patient via the drain line; one of: (i) a water purifier for supplying purified water for mixing to form fresh dialysis fluid at the disposable set, (ii) at least one fresh dialysis fluid container configured as a part of the disposable set for supplying fresh dialysis fluid, or (iii) a dialysis fluid preparation unit configured to supply fresh dialysis fluid to the disposable set; and at least one flow path isolator disposed alongside at least one of the circulator, the water purifier, the dialysis fluid preparation unit, or along the drain line, wherein the flow path isolator comprises a length of coiled tubing sized to increase electrical resistance to a leakage current residing in used dialysis fluid flowing through the length of coiled tubing.

12. The peritoneal dialysis system of claim 11, wherein, A ratio of a length (L) of the length of coiled tubing to a cross-sectional area (A) of the length of coiled tubing is 10,000:8.

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