A medical device includes a constant-flow pump configured to pump a fluid through a fluid conduit and a rotary valve fluidically connected to the pump. The rotary valve includes at least one rotatable valve member configured to be operatively connected to and rotate relative to the fluid conduit. The rotatable valve member includes at least one aperture. The rotatable valve member is capable of being positioned in a plurality of positions relative to the conduit. The position of the at least one first aperture of the rotatable valve member controls fluid flow through the rotary valve, and thereby through the conduit.

The invention relates to an apparatus for extracorporeal blood treatment, comprising a blood treatment unit 1 that comprises at least one compartment 3. The invention further relates to an apparatus 15A, 15B for collecting blood clots for a blood line 5, 7 for supplying blood to or removing blood from a blood treatment unit 1 of an extracorporeal blood treatment apparatus, and to a method for determining a hemodynamic parameter during extracorporeal blood treatment using an extracorporeal blood treatment apparatus. In order to determine the hemodynamic parameter, the conveying direction of the blood pump 10 is reversed from a “normal” blood flow to a “reversed” blood flow. It has been found in practice that, in the event of a reversal in the conveying direction of the blood pump in order to carry out a measurement for determining a hemodynamic parameter, there is a risk of blood clots reaching the patients, although the dialyser traps blood clots. The apparatus according to the invention provides an apparatus 15A for catching blood clots, at least in the blood line of the extracorporeal blood circuit I that leads to the blood treatment unit 1 during a “normal blood flow”. The blood treatment unit traps blood clots during blood treatment having a “normal” blood flow. In the case of a “reversed” blood flow, the apparatus for catching blood clots in the blood line that leads to the blood treatment unit 1 during a “normal blood flow” traps blood clots that may have previously accumulated at the inlet of the blood treatment unit.

The present invention generally relates to hemodialysis and similar dialysis systems, including a variety of systems and methods that would make hemodialysis more efficient, easier, and/or more affordable. One aspect of the invention is generally directed to new fluid circuits for fluid flow. In one set of embodiments, a hemodialysis system may include a blood flow path and a dialysate flow path, where the dialysate flow path includes one or more of a balancing circuit, a mixing circuit, and/or a directing circuit. Preparation of dialysate by the preparation circuit, in some instances, may be decoupled from patient dialysis. In some cases, the circuits are defined, at least partially, within one or more cassettes, optionally interconnected with conduits, pumps, or the like. In one embodiment, the fluid circuit and/or the various fluid flow paths may be at least partially isolated, spatially and/or thermally, from electrical components of the hemodialysis system. In some cases, a gas supply may be provided in fluid communication with the dialysate flow path and/or the dialyzer that, when activated, is able to urge dialysate to pass through the dialyzer and urge blood in the blood flow path back to the patient. Such a system may be useful, for example, in certain emergency situations (e.g., a power failure) where it is desirable to return as much blood to the patient as possible. The hemodialysis system may also include, in another aspect of the invention, one or more fluid handling devices, such as pumps, valves, mixers, or the like, which can be actuated using a control fluid, such as air. In some cases, the control fluid may be delivered to the fluid handling devices using an external pump or other device, which may be detachable in certain instances. In one embodiment, one or more of the fluid handling devices may be generally rigid (e.g., having a spheroid shape), optionally with a diaphragm contained within the device, dividing it into first and second compartments.

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.

Automated control mechanisms and methods for controlling fluid flow in a hemodialysis apparatus are described. The methods can involve a controller receiving information from a pressure sensor in a control chamber of a reciprocating diaphragm-based blood pump and causing the application of a time-varying pressure waveform on a diaphragm of the blood pump during a fill-stroke of the blood pump. The controller can be configured and programmed to monitor a pressure variation in the control chamber measured by the pressure sensor and to compare the measured pressure variation to a pre-determined value. Based on such comparison, the controller can initiate a procedure to pause or stop a dialysate pump of the hemodialysis apparatus if the magnitude of the measured pressure variation deviates from the pre-determined value.

The present disclosure relates to an effluent bag for collecting accumulated blood treatment effluent. The effluent bag comprises a closeable effluent opening or connection to an exterior of the effluent bag. The disclosure further relates to methods, a blood treatment apparatus, and a discharge hose system.

This document describes stepper motor drive systems. The stepper motor drive systems can be used in many different applications including, for example, to drive a stepper motor of an occluder device in association with a heart-lung machine.

A method of performing dialysis includes: recirculating a dialysis fluid from a patient or a dialyzer for at least two cycles, each cycle contacting the dialysis fluid first with a zirconium phosphate layer followed by at least one of a urease layer, a zirconium oxide layer, or a carbon layer; storing the recirculated dialysis fluid in a storage container; and transferring the dialysis fluid from the storage container to the patient or the dialyzer. In one example, the zirconium phosphate layer and the at least one of the urease layer, the zirconium oxide layer, or the carbon layer is provided by a sorbent cartridge.

A blood filtration device comprising a generally cylindrical housing having an interior wall. An interior member is mounted interior of the housing and comprises an outer surface having a porous membrane disposed thereon. The housing and interior member are relatively rotatable and define an annular gap therebetween. The blood filtration device also comprises an inlet for directing fluid into the annular gap, a first outlet for exiting filtrate passing through the membrane, and a second outlet for directing from the annular gap the remaining retentate. The porous membrane comprises a first layer and a second layer.

The invention relates to an apparatus and to a method for supplying dialysate. The invention also relates to a dialysis apparatus comprising an apparatus for supplying dialysate. The apparatus for supplying dialysate has a balancing device 8, which comprises at least one balancing chamber 9, 10 for balancing fresh and used dialysate, and a metering device 28 for filling the at least one balancing chamber with permeate and concentrates in a specified mixing ratio for producing dialysate. The metering device 28 is designed such that specified volumes of concentrates are conveyed into the at least one balancing chamber 9, 10 in successive working cycles. Given that the specified volumes of concentrates are not added simultaneously, the concentrates can be conveyed using just one single metering pump. This is advantageous in that the metering pump is a relatively expensive component of the mixer circuit. In practice, the design is simpler and compact and the maintenance costs are reduced.