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 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. Improved heater control circuitry is also disclosed, to provide added or redundant safety measures, or to reduce current leakage from a heater element during pulse width modulation control of the heater element. Improvements are also disclosed in an application of negative pressure during a drain phase in peritoneal dialysis therapy, and to control an amount of intraperitoneal fluid accumulation during the therapy. Improvements in efficiency are also disclosed in movement of fluid into and out of a two-pump cassette and a heater bag of the peritoneal dialysis cycler, and in synchronization of operation of two or more pumps in the peritoneal dialysis cycler or other fluid handling devices using a multi-pump arrangement.

Peritoneal dialysis admixing and/or treatment devices, methods, and systems are disclosed. The systems, methods, and devices provide high-level guarantees of sterility and employs relatively inexpensive disposable components to provide pumping. Disclosed systems, methods, and devices and features thereof are adapted for point of use generation of medicament. In particular admixing systems that employ independently-replaceable long term concentrate are disclosed. Features are directed to assurance of sterility and accurate admixing of water and concentrate to generate ready-to-use medicaments and other benefits.

Dialysis systems are disclosed comprising new fluid flow circuits. Systems may include blood and dialysate flow paths, where the dialysate flow path includes balancing, mixing, and/or directing circuits. Dialysate preparation may be decoupled from patient dialysis. Circuits may be defined within one or more cassettes. The fluid circuit fluid flow paths may be isolated from electrical components. A gas supply in fluid communication with the dialysate flow path and/or the dialyzer able to urge dialysate through the dialyzer and urge blood back to the patient may be included for certain emergency situations. Fluid handling devices, such as pumps, valves, and mixers that can be actuated using a control fluid may be included. Control fluid may be delivered by an external pump or other device, which may be detachable and/or generally rigid, optionally with a diaphragm dividing the device into first and second compartments.

The invention relates to a system for treating blood, which includes a single cassette capable of carrying out the various CRRT treatments.

The invention relates to the balancing of fluid streams in a dialysis system. In particular the invention relates to a cassette for conveying a first and a second fluid stream in a dialysis system, wherein the first and the second fluid streams can be medical fluid streams such as for example dialysate streams or blood streams, wherein the cassette has a sensor as a device for balancing the first and the second fluid stream, and wherein the sensor has a first channel for the first fluid stream and a second channel for the second fluid stream. The invention further relates to a dialysis system, which is configured to accommodate at least one cassette which is configured as described above. Furthermore, the present invention relates to an arrangement by which two channels for the first and the second fluid streams are formed. In addition, the invention relates to a method for construction of the two channels or the arrangement.

The present specification describes a modular, portable hemofiltration system, for providing improved clearance levels of blood toxins, which includes at least one roller pump that is designed and operated to generate a rapidly varying pressure profile of fluid within at least a blood circuit of the hemofiltration system.

The hemodialysis system includes a closed loop dialysate flow path which includes a dialyzer and a reservoir for storing dialysate, and a closed loop blood flow path which passes through the dialyzer in the opposite direction as the dialysate flow path. In addition, the hemodialysis system includes pumps for pumping dialysate and blood through their respective flow paths, a flow sensor for measuring the flow rate of dialysate in the dialysate flow path, and a level sensor for measuring the level of dialysate in the dialysate reservoir. A processor is connected to the flow sensor, reservoir level sensor and pumps to provide a first closed loop control system including the processor, flow sensor and a first dialysate pump, and a second closed loop control system including the processor, level sensor and a second dialysate pump which enable the processor to initiate, monitor and maintain ultrafiltration.

Disclosed are example embodiments of a dialysis machine having a frame, a cartridge cassette, one or more alignment-locking features, and an actuation mechanism. The frame is fixedly coupled to the dialysis machine, and the cassette is slidably coupled to the frame. The cassette can have one or more track structures, with each of the one or more track structures having a rotor and one or more rollers. The one or more alignment-locking features extend from the frame and are configured to be inserted into one or more alignment features of a disposable cartridge that functions to secure or release the disposable cartridge. The actuation mechanism is made to slide the cassette with respect to the one or more track structures.

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 method for testing the rigidity of a particular disposable for volumetric balancing, for a blood treatment device. The method includes filling the disposable or portion thereof with a liquid, enclosing the filled liquid, so that a certain volume of liquid is present in the disposable unit or the portion thereof, supplying and/or discharging a certain volume of liquid, and measuring the change in pressure caused by the supply and/or discharge of the volume of liquid. A blood treatment device is also provided.