The present invention involves, in some embodiments, systems and methods for pumping fluid into or out of a patient via a cartridge. The cartridge may include a membrane defining a chamber and mechanisms to supply, measure and control pressure in the chamber. The system further includes a processor that can be configured to compare certain pressure measurements to each other to facilitate determining if an error condition exists in the medical system if the difference between measurements is greater than a threshold. In certain cases the error condition may indicate leakage of the membrane, for example due to a pinhole in the membrane.

The present invention involves, in some embodiments apparatus, such as dialysis apparatus, and methods for pumping fluid. Certain embodiments comprise a housing enclosing a pump drive assembly for actuating at least one pump on a removable fluid pumping cassette. The housing may comprise a door connected to the housing for enclosing an installed cassette in the housing upon closure of the door. The pump drive assembly may comprise a mating block configured for operative association with an installed cassette and may be configured to permit a sealing engagement with an installed cassette upon closure of the door. To facilitate sealing, certain embodiments of the door include a movable compression plate configured to exert a compressive force on an installed cassette against the mating block when the door is in a closed position.

The present disclosure includes systems and methods for hemodialysis, such as including a first dialysis module and an auxiliary module detachably connectable to the first dialysis module. The first dialysis module can include a dialyzer, a blood circuit, a dialysate circuit, and a sorbent. The auxiliary module can include an ultrafiltrate collector operably couplable to the dialysate circuit for removing excess fluid therefrom.

A hemodialysis system is disclosed. The hemodialysis system includes a dialyzer and an online dialysate generation system comprising a water inlet line and a drain line. The hemodialysis system also includes a disposable set comprising a supply tube fluidly connected to online dialysate generation system and a dialysate pumping tube fluidly connected to the dialyzer. The hemodialysis system further includes a dialysis instrument comprising a dialysate pump head and a motor positioned and arranged to operate the dialysate pump head. The dialysis instrument operates the dialysate pump head to move fresh dialysate from the online dialysate generation system through the dialysate pumping tube to the dialyzer.

This invention relates to a dialysis apparatus which ultra-filters blood and to a related method of ultra-filtering blood ex-vivo. More preferably the invention relates to haemodiafiltration using protein-losing membranes and a secondary ultrafiltration and partial re-infusion of haemodiafiltrate for increasing extraction of middle molecules and protein bound uraemic toxins and reducing albumin loss.