A peritoneal dialysis system is provided that includes a hardware unit, a disposable unit received by the hardware unit, and a controller. The hardware unit includes a recessed area, a piston having a contact surface, a pneumatic source for supplying a negative pressure, and an actuator configured to move the contact surface of the piston into and out of at least a portion of the recessed area. The disposable unit includes an outer member fitted at least partially within the recessed area of the hardware unit and a moveable membrane positioned between the contact surface of the piston and the outer member when the disposable unit is received by the hardware unit. The controller is configured to cause the pneumatic source to apply the negative pressure to the moveable membrane so as to conform the moveable membrane to a shape of the contact surface of the piston and follow the contact surface when the piston is moved towards and away from the outer member fitted at least partially within the recessed area.

A machine is provided with a slot to releasably receive and retain a cartridge in which dialysis is effected. The machine is configured for supplying to the cartridge, at a controlled temperature and rate, sterile water for use in haemodialysis and is operable to maintain, in a sterile condition, residual water contained therein after completion of a haemodialysis treatment.

A dialysis system includes a dialysis instrument including a blood pump, a dialysate inlet pump, a dialysate outlet pump, and at least one fluid velocity sensor, each sensor including an emitter and a receiver, a dialyzer arranged (i) to receive blood pumped by the blood pump, (ii) to receive fresh dialysate pumped by the dialysate inlet pump and (iii) such that used dialysate is pumped from the dialyzer by the dialysate outlet pump, and a disposable cassette including a to-dialyzer dialysate pathway carrying dialysate pumped by the dialysate inlet pump and a from-dialyzer dialysate pathway carrying used dialysate pumped by the dialysate outlet pump, wherein at least one of the to-dialyzer dialysate pathway or the from-dialyzer dialysate pathway includes at least one sensing area so positioned and arranged such that when the disposable cassette is mounted to the instrument, the sensing area is coupled operably with both the emitter and the receiver of the at least one fluid velocity sensor.

A method is provided for detecting leaks in a disposable medical fluid cassette that includes a base and a flexible membrane attached to the base in such a way that the base and the flexible membrane cooperate to at least partially form a fluid passageway. The method includes applying a first force to the flexible membrane, measuring a first physical property of a system that includes the medical fluid cassette a medical fluid pumping machine, removing the first force from the flexible membrane, applying a second force to the flexible membrane, measuring a second physical property of the system, and determining whether the medical fluid cassette leaks based on a comparison of the first physical property and the second physical property.

A system for dialysis is disclosed. An example peritoneal dialysis system includes a peritoneal dialysis machine including a pumping mechanism, and a sensor configured to measure a property of peritoneal dialysis fluid. The peritoneal dialysis system also includes a disposable cassette operable with the peritoneal dialysis machine. The disposable cassette includes a fluid source inlet for accepting fluid from a fluid source and a fluid flow path in fluid communication with the fluid source inlet. The fluid flow path includes a pump chamber operable with the pumping mechanism to pump fluid through the fluid flow path. The disposable cassette also includes a concentrate inlet for fluidly communicating concentrate to the fluid flow path, and a sensor chamber located along the fluid flow path and operable with the sensor. The sensor is configured to provide feedback to the peritoneal dialysis machine for mixing the concentrate for forming peritoneal dialysis fluid.

A dialysis system has a module with a dialyzer configured to remove one or more substances from a dialysis solution as it passes through a dialyzer. The module has a fluid line, a sorbent cartridge, and a sodium control system adapted to actively alter a sodium concentration of dialysis solution passing through the fluid line as the dialysis solution exits the sorbent cartridge. The sodium control system has a conductivity sensor that sends a signal indicating the conductivity of the dialysis solution as the dialysis solution exits the sorbent cartridge, the conductivity meter being in communication with the sodium control system, a processor configured to receive the signal from the conductivity sensor, compare the conductivity signal to a threshold value lower than a prescription value, and cause the sodium control system to stop actively altering the sodium concentration if the signal is greater than the threshold value.

A dialysis machine (e.g., a peritoneal dialysis (PD) machine) can include a control unit configured to monitor an amount of fluid withdrawn from a heater bag line during a PD treatment. A processor in the control unit is configured to operate a first pump to draw fluid into a first pump chamber and measure a first fluid volume in the first pump chamber. The processor is further configured to operate the first pump and a second pump to transfer fluid from the first pump chamber to a second pump chamber, measure a second fluid volume in the second pump chamber, and determine a measured fluid volume for a single pump cycle based on the first fluid volume and the second fluid volume. The first fluid volume is correlated to the second fluid volume and, therefore, the multiple independent measurements increase an accuracy of the fluid volume measurement.

A medical infusion fluid handling system, such as an automated peritoneal dialysis system, may be arranged to de-cap and connect one or more lines (such as solution lines) with one or more spikes or other connection ports on a fluid handling cassette. This feature may reduce a likelihood of contamination since no human interaction is required to de-cap and connect the one or more lines and the one or more spikes. For example, the automated peritoneal dialysis system may include a carriage arranged to receive the one or more lines each having a connector end and a cap. The carriage may move along a first direction so as to move the connector ends of the one or more lines along the first direction, and a cap stripper may be arranged to engage with the caps on the the one or more lines on the carriage. The cap stripper may move in a second direction transverse to the first direction, as well as to move with the carriage along the first direction.

A pump cassette comprising an outer flexible membrane covering flowpaths, valve chambers and pump chambers of the cassette is designed to be actuated by a control gasket on a base unit arranged to move designated valve and pump portions of the cassette membrane. The performance of a cassette valve may improved by optimizing the configuration of the valve control region of the control gasket overlying the cassette valve. This may improve both fluid flow through the valve and reduce the amount of vibratory noise associated with opening the valve. The gasket valve control or actuation region is at least partially bounded by a vacuum channel facing the outside of the gasket so that a constant vacuum can be applied between the gasket valve control or actuation region and the adjacent portion of the cassette membrane. An improved version of the vacuum channel comprises a flexible inner wall (contiguous with the valve control region) so that the inner wall flexes or partially collapses away from the cassette valve seat, while still maintaining patency of the vacuum channel during the application of negative pressure on the gasket valve actuation region to open the cassette valve.

A peritoneal dialysis system includes a cycler including a pump actuator, a heater and a heating pan operable with the heater, and a disposable set operable with the cycler. The heating pan includes a sidewall forming a slot. The disposable set includes a pumping cassette and a heater/mixing container. The pumping cassette includes a pump chamber configured to be actuated by the pump actuator. Additionally, the heater/mixing container is in fluid communication with the pumping cassette and is sized to be received at the heating pan. The heater/mixing container includes a port configured such that when the port is slid into the slot of the heater pan sidewall, the port is prevented from rotating about an axis transverse to a direction of flow through the port.