A protected fluid circuit can utilize osmotic membranes or other membrane types that are highly selective to urea transport. The membranes can achieve sufficient diffusional flux of urea in a forward osmosis geometry. When combined with a oxidation unit, this protected geometry can have a high selective flux of urea from the spent dialysate side to the urea removal side; balance of fluid (water) levels in patients by forward osmotic flow by controlling water evaporation rate through an vapor permeable membrane; protection of patient dialysate/blood loop from oxidation by-products; and an ability to optimize oxidation system performance (pH, ionic strength, other electrolytes, etc.) that would be otherwise incompatible with blood contact.

A peritoneal dialysis system includes a drain container; a drain line in fluid communication with the drain container and a patient's peritoneal cavity; a solenoid configured to permit a pneumatic force through a vacuum line and open a drain valve of the drain line; the vacuum source configured to apply and adjust the pneumatic force; the vacuum line; a weight sensor configured to output a weight of used dialysis fluid delivered to the drain container from the patient's peritoneal cavity; and the controller configured to: (i) determine an actual flow rate of used dialysis fluid removed from the patient's peritoneal cavity based on the output from the weight sensor; (ii) compare the actual flow rate to a desired flow rate; and (iii) adjust the pneumatic force applied by the vacuum source via the solenoid to attempt to match the actual flow rate to the optimal flow rate.

A peritoneal dialysis system includes a cycler comprising a control unit and a pump actuator. The peritoneal dialysis system also includes a disposable set operable with the cycler and in fluid communication with a source of water made suitable for peritoneal dialysis (WFPD) and a source of concentrate. The disposable set includes a pumping cassette comprising a pump chamber configured to be actuated by the pump actuator and a mixing container. The control unit is programmed to cause (i) the pump actuator to operate the pump chamber to pump a first amount of the WFPD to the mixing container, (ii) the pump actuator to operate the pump chamber to pump a prescribed amount of concentrate from the concentrate source to the mixing container, and (iii) the pump actuator to operate the pump chamber to pump a second amount of the WFPD to the mixing container.

A peritoneal dialysis system includes a water purifier, a cycler, and a disposable set operable with the cycler. The disposable set includes a pumping cassette including a water inlet port, a heater/mixing container in fluid communication with the pumping cassette, a water accumulator, a first water line segment, and a second water line segment. The first water line segment is in fluid communication with the water inlet port and the water accumulator. Additionally, the second water line segment is in fluid communication with the water accumulator and the water purifier.

A renal failure therapy system for performing a peritoneal dialysis therapy is disclosed. The renal failure therapy system performs a plurality of peritoneal dialysis cycles for a patient and tracks an amount of dialysis fluid provided by a dialysis fluid pump during the plurality of peritoneal dialysis cycles. The renal failure therapy system also determines, as an initial drain volume, how much dialysis fluid resides in the patient's peritoneal cavity at a start of a next dialysis treatment and determines an initial drain flow for the next dialysis treatment. The renal failure therapy system generates an alert when it is determined from the initial drain flow that a low drain flow or a drain flow stoppage could occur before the initial drain volume is recovered for the start of the next dialysis treatment.

An example peritoneal dialysis system is disclosed. The example peritoneal dialysis system includes an automated peritoneal dialysis (APD) machine comprising a pumping mechanism and a peritoneal dialysis fluid heater. The example peritoneal dialysis system also includes a disposable set comprising a disposable cassette operable with the pumping mechanism and a heater bag operable with the heater. The example peritoneal dialysis system additionally includes a conductivity sensor positioned and arranged to provide feedback to the APD machine. The example APD machine is configured to mix a peritoneal dialysis fluid for treatment in the heater bag using a plurality of peritoneal dialysis constituent fluids. In addition, the example APD machine is configured to use feedback from the conductivity sensor to evaluate the mixed peritoneal dialysis fluid for treatment.

A dialysis system is disclosed. The example dialysis system includes a housing, a pump actuator housed by the housing, a fluid pumping cassette coupled operably to the housing and including a flexible membrane covering a pump chamber, and a mechanically actuated piston head provided by the pump actuator and positioned to extend towards and away from the fluid pumping cassette. The fluid pumping cassette is positioned such that the flexible membrane of the fluid pumping cassette faces the piston head so that the piston head can push the flexible membrane into the pump chamber of the fluid pumping cassette to expel a fluid from the pump chamber. The example dialysis system also includes a controller programmed to perform a leak test by monitoring a sensed position of the mechanically actuated piston head while the mechanically actuated piston head applies a force to the flexible membrane of the fluid pumping cassette.

A fluid sensing device is provided, including a main body and a light sensing unit. The main body includes a casing and a rotary member. A containing chamber is formed in the casing. The rotary member is rotatably disposed in the casing, and the rotary member has at least one transparent portion. A fluid flows into the containing chamber to drive the rotary member rotating around a central axis. The light sensing unit includes a first light transceiver module and a second light transceiver module disposed near the main body in an asymmetrical manner with respect to the central axis to transmit and receive the light passing through the translucent portion.

A method that includes pumping medical fluid out of or drawing medical fluid into a chamber of a medical fluid cassette, calculating a theoretical volume of fluid pumped out of or drawn into the chamber, and multiplying the theoretical volume of fluid pumped out of or drawn into the chamber by a correction factor to determine a corrected volume of fluid pumped out of or drawn into the chamber.

A peritoneal dialysis device includes: a dialysate catheter that is connected at a first end to a dialysate container connector and at a second to a four-way joint; an injection catheter that is connected at a first end to an injection catheter connector and at a second end to the four-way joint; a waste fluid catheter that is connected at a first end to a waste fluid container connector and at a second end to the four-way joint; and a syringe catheter that is connected at a first end to a syringe and at a second end to the four-way joint.