The disclosed subject matter relates to extracorporeal blood processing or other processing of fluids. Volumetric fluid balance, a required element of many such processes, may be achieved with multiple pumps or other proportioning or balancing devices which are to some extent independent of each other. This need may arise in treatments that involve multiple fluids. Safe and secure mechanisms to ensure fluid balance in such systems are described.

The invention relates to a control unit (30) for detecting an overshoot of a first limit value (G1) of a first blood concentration (B1) in a first portion (17a) of a dialysate discharge line (17) downstream of a dialysate chamber (7) of a dialyser (4) of a blood treatment device and upstream of a node point (110) at which a bypass line (100) bypassing the dialyser (4) leads into the dialysate discharge line (17), wherein the bypass line (100) branches off, upstream of the dialysate chamber (7), from a dialysate supply line (15) suitable for supplying dialysate from a dialysate source (16) to the dialysate chamber (7).

A device for extracorporeal blood treatment includes a balancing system and calculates an ultrafiltration volume (UF.sub.D) as a volume withdrawal on the basis of a pressure difference (.sub.P) and a temperature difference (.sub.T) at an inlet and an outlet of at least two balance chambers. To this end, pressure sensors are arranged directly behind an inlet and an outlet of the at least two balance chambers, respectively, and determine a fluid pressure at their respective position, and temperature sensors are arranged at inputs of the at least two balance chambers and determine a temperature in the inlet and the outlet of the balance chamber. The ultrafiltration volume (UD.sub.F) is calculated using the pressure difference (.sub.P) established on the basis of fluid pressure values determined by the pressure sensors, and the temperature difference (.sub.T) established on the basis of temperature values determined by the temperature sensors.

A device for extracorporeal blood treatment, in particular a dialysis machine, including an internal fluidic system to which a blood treatment unit, in particular a dialyzer, can be connected, the internal fluidic system comprising at least one balancing chamber on the fresh flow side for balancing fresh treatment fluid flowing to the blood treatment unit and at least one balancing chamber on the used flow side for balancing used treatment fluid flowing off the blood treatment unit, wherein the device has a measuring device for gravimetric detection of treatment fluid in the balancing chamber on the fresh flow side and/or a measuring device for gravimetric detection of treatment fluid in the balancing chamber on the used flow side. A method of balancing treatment fluid in such a device.

Dialysis systems comprising actuators that cooperate to perform dialysis functions and sensors that cooperate to monitor dialysis functions are disclosed. According to one aspect, such a hemodialysis system comprises a user interface model layer, a therapy layer, below the user interface model layer, and a machine layer below the therapy layer. The user interface model layer is configured to manage the state of a graphical user interface and receive inputs from a graphical user interface. The therapy layer is configured to run state machines that generate therapy commands based at least in part on the inputs from the graphical user interface. The machine layer is configured to provide commands for the actuators based on the therapy commands

Dialysis systems comprising actuators that cooperate to perform dialysis functions and sensors that cooperate to monitor dialysis functions are disclosed. According to one aspect, such a hemodialysis system comprises a user interface model layer, a therapy layer, below the user interface model layer, and a machine layer below the therapy layer. The user interface model layer is configured to manage the state of a graphical user interface and receive inputs from a graphical user interface. The therapy layer is configured to run state machines that generate therapy commands based at least in part on the inputs from the graphical user interface. The machine layer is configured to provide commands for the actuators based on the therapy commands.

A hemodialysis system is disclosed. The hemodialysis system includes a disposable set including a blood pumping tube, a fresh dialysate pumping tube, and a spent dialysate pumping tube. The hemodialysis system also includes a dialysis instrument including a blood pump head, a fresh dialysate pump head, a spent dialysate pump head, a first motor positioned and arranged to operate the blood pump head, a second motor positioned and arranged to operate the fresh dialysate pump head, and a third motor positioned and arranged to operate the spent dialysate pump head. When the disposable set is loaded into the dialysis instrument, the blood pumping tube comes into registry with the blood pump head, the fresh dialysate pumping tube comes into registry with the fresh dialysate pump head, and spent dialysate pumping tube comes into registry with the spent dialysate pump head.

Embodiments of the present disclosure include a dialysis system having a disposable cartridge which includes one or more flowpaths arranged on or within the cartridge, where the one or more flowpaths including at least one of a blood flowpath for carrying a volume of blood to be treated in a dialyser and a dialysate flowpath, isolated from the blood flowpath, for delivering a flow of dialysate solution through the dialyser.

A dialysis machine has a dialyzer (D), a water inlet system for supplying the dialyzer (D) with fresh dialysis fluid which is connected to the dialyzer and an external water supply and with a line for used dialysis fluid, which is in communication with the dialyzer (D). The water inlet system includes a container for water or other liquid, in particular for RO water. The dialysis machine includes a heat exchanger connected with the line for used dialysis fluid and with the water inlet system so that heat is transferred from the used dialysis fluid to the liquid present in the water inlet system. The container includes means for physical separation of the external water supply and the downstream portions of the water inlet system, preferably a free-fall path for incoming liquid from the water supply, and the heat exchanger is arranged downstream of the container.

Medical fluid management assembly includes: a pneumatic manifold including multiple plates forming pneumatic passageways, a pneumatic valve chamber and a pneumatic pump chamber, the valve chamber in pneumatic communication with at least one passageway, the pump chamber in pneumatic communication with at least one passageway; and a fluid manifold including multiple fluid pathways, a fluid valve chamber in selective fluid communication with a fluid pump chamber and at least one fluid pathway, wherein (a) the pneumatic valve chamber and the fluid valve chamber are mated together to compress a membrane and (b) the pneumatic pump chamber and the fluid pump chamber are mated together to compress a membrane, wherein at least one of the pneumatic valve chamber or the pneumatic pump chamber extends from the at least one plate, or the fluid valve chamber or the fluid pump chamber extends from the fluid manifold to aid in compressing the membranes.