A fluid handling cassette, such as that useable with an automated peritoneal dialysis (APD) cycler device or other infusion apparatus, may include a generally planar body having at least one pump chamber formed as a depression in a first side of the body and a plurality of flowpaths for a fluid that includes a channel. A patient line port may be arranged for connection to a patient line and be in fluid communication with the at least one pump chamber via at least a first one of said flowpaths, and an optional membrane may be attached to the first side of the body over the at least one pump chamber. In one embodiment, the membrane may have a pump chamber portion with an unstressed shape that generally conforms to the depression of the at least one pump chamber in the body and is arranged to be movable for movement of the fluid in a useable space of the at least one pump chamber. One or more spacers may be provided in the at least one pump chamber to prevent the membrane from contacting an inner wall of the at least one pump chamber. The patient line, a drain line, and/or a heater bag line may be positioned to be separately occludable in relation to one or more solution lines that are connectable to the cassette.

A pump cassette is disclosed. The pump cassette includes a housing having at least one fluid inlet line and at least one fluid outlet line. The cassette also includes at least one reciprocating pressure displacement membrane pump within the housing. The pressure pump pumps a fluid from the fluid inlet line to the fluid outlet line. A hollow spike is also included on the housing as well as at least one metering pump. The metering pump is fluidly connected to the hollow spike on the housing and to a metering pump fluid line. The metering pump fluid line is fluidly connected to the fluid outlet line.

A fluid-handling cassette comprising a plurality of diaphragm valves and pumps is configured to have its actuation ports located along a thin or narrow edge of the cassette. Actuation channels within the cassette lead from the actuation ports to actuation chambers of the valves and pumps in a space between plates that comprise the cassette. The individual plates have a nominal thickness that is sufficient to provide a rigid ceiling for the actuation channels, but sufficiently thin to minimize the overall thickness of the cassette. The cassette can be plugged into or unplugged from an actuation receptacle or a manifold by its narrow edge. A plurality of such cassettes can be stacked together or spaced apart from each other to form a cassette assembly, providing for a convenient way to install and remove the cassette assembly from its actuation receptacle. The arrangement allows for an improved way of connecting a complex cassette assembly to its associated pressure distribution manifold without the use of a plurality of flexible connecting tubes between the two.

A peritoneal dialysis system includes a cycler having a pumping actuator configured to move an incompressible fluid, a positive pressure actuator, and a control unit; and a disposable set including a chamber including an opening, and at least one plate (e.g., rigid plate) located within the chamber, wherein the control unit is programmed to cause (i) the pumping actuator to move the incompressible fluid to discharge fresh or used dialysis fluid from the chamber through the opening and (ii) the positive pressure actuator to expand the at least one plate to create negative pressure within the chamber to pull fresh or used dialysis fluid into the chamber through the opening.

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.

Components for a medical infusion fluid handling system, such as an APD system, in which one or more lines (such as solution lines), spikes or other connection ports may be automatically capped and/or de-capped. This feature may provide advantages, such as a reduced likelihood of contamination since no human interaction is required to de-cap and connect the lines, spikes or other connections. For example, a fluid handling cassette may include one or more caps that cover a corresponding spike and include a raised and/or recessed feature to assist in removal of the cap from the cassette. A solution line cap may include a hole and recess, groove or other feature to engage with a spike cap and enable removal of the cap.

A hemodialysis system is disclosed. The hemodialysis system includes a dialyzer, a saline container including saline, and a disposable set comprising a blood pumping tube fluidly connected to a first end of the dialyzer, an arterial line fluidly connected to a first end of the blood pumping tube, a venous line fluidly connected to a second end of the dialyzer, a saline line fluidly connected to the blood pumping tube and the saline container, and a dialyzer line fluidly connected to a second end of the blood pumping tube and a second end of the dialyzer. The hemodialysis system also includes a dialysis instrument comprising an arterial line clamp, a venous line clamp, and a saline valve. The saline rinses blood out of the arterial line when the venous line clamp is closed, the arterial line clamp is opened, and the saline value is opened.

A peritoneal dialysis system includes first and second concentrate sources in selective fluid communication with a medical fluid pumping cassette, the first and second concentrate sources holding first and second peritoneal dialysis concentrates, respectively; a pump actuator configured to cause the medical fluid pumping cassette to pump the first and second concentrates; and a processor and memory configured to (i) determine a cumulative volume of at least one of the first or second peritoneal dialysis concentrates pumped from the medical fluid pumping cassette by the pump actuator, (ii) compare the cumulative volume to a threshold, and (iii) if the cumulative volume is outside of the threshold, modify a subsequent stroke volume of at least one of the first or second pump chambers actuated by the pump actuator in an attempt to cause an updated cumulative volume for the at least one peritoneal dialysis concentrate to be within the threshold.

Improvements in fluid volume measurement systems are disclosed for a pneumatically actuated diaphragm pump in general, and a peritoneal dialysis cycler using a pump cassette in particular. Pump fluid volume measurements are based on pressure measurements in a pump control chamber and a reference chamber in a two-chamber model, with different sections of an apparatus being modeled using a combination of adiabatic, isothermal and polytropic processes. Real time or instantaneous fluid flow measurements in a pump chamber of the diaphragm pump are also disclosed, in this case using a one-chamber ideal gas model and using a high speed processor to obtain and process pump control chamber pressures during fluid flow into or out of the pump chamber.

A method for performing a peritoneal dialysis therapy includes performing a plurality of peritoneal dialysis cycles for a patient and tracking an amount of dialysis fluid provided by at least one dialysis fluid pump during the plurality of peritoneal dialysis cycles. The method also includes determining an amount of ultrafiltrate (“UF”) removed from the patient based on the amount of dialysis fluid provided by the at least one dialysis fluid pump. The method further includes updating a UF trend using previous amounts of UF removed from the patient and the amount of UF removed from the patient during the most recent dialysis treatment and generating an alert if the UF trend changes by more than a preset percentage.