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.

A dialysis system is disclosed. The example dialysis system includes a housing, a pump actuator housed by the housing, a fluid pumping cassette coupled operably to the housing and including a flexible membrane covering a pump chamber, and a mechanically actuated piston head provided by the pump actuator and positioned to extend towards and away from the fluid pumping cassette. The fluid pumping cassette is positioned such that the flexible membrane of the fluid pumping cassette faces the piston head so that the piston head can push the flexible membrane into the pump chamber of the fluid pumping cassette to expel a fluid from the pump chamber. The example dialysis system also includes a controller programmed to perform a leak test by monitoring a sensed position of the mechanically actuated piston head while the mechanically actuated piston head applies a force to the flexible membrane of the fluid pumping cassette.

A hemodialysis system is disclosed. The hemodialysis system includes a dialyzer, a saline container including saline, and a disposable set comprising a blood pumping tube fluidly connected to a first end of the dialyzer, an arterial line fluidly connected to a first end of the blood pumping tube, a venous line fluidly connected to a second end of the dialyzer, a saline line fluidly connected to the blood pumping tube and the saline container, and a dialyzer line fluidly connected to a second end of the blood pumping tube and a second end of the dialyzer. The hemodialysis system also includes a dialysis instrument comprising an arterial line clamp, a venous line clamp, and a saline valve. The saline rinses blood out of the arterial line when the venous line clamp is closed, the arterial line clamp is opened, and the saline value is opened.

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.

Hemodialysis systems are described. A hemodialysis system may include a dialysate flow path through which dialysate is passed from a dialysate reservoir, which includes a valved vent to atmosphere, to an ultrafilter. The dialysate flow path includes a pneumatically actuated diaphragm-based dialysate pump for pumping fluid from the dialysate reservoir to the ultrafilter. The hemodialysis system may include a controller for controlling pneumatic actuation pressure delivered to the dialysate pump and at least one valve connecting the dialysate reservoir vent to the atmosphere. The hemodialysis system may be configured to actuate the dialysate pump and the at least one valve to introduce air into the dialysate flow path and expel liquid from the dialysate flow path to a drain.

Simple-to-use systems, methods, and devices for priming replacement blood treatment devices, for swapping the blood treatment devices out, for replacing swapped-out blood treatment devices, and other related operations are described. In embodiments, a blood treatment device can be primed while a therapy is still running. When the replacement blood treatment device is needed, the therapy can be stopped momentarily (less than a minute) for the rapid and safe swap of the blood treatment device. Blood loss can be minimized. The down time from therapy can be minimized.

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.

An extracorporeal therapy system includes: (i) a dialysis fluid circuit including dialysis fluid preparation structure configured to prepare a dialysis fluid for an extracorporeal therapy treatment; (ii) a blood circuit including a blood filter for use during the extracorporeal therapy treatment; (iii) a blood pump operable to pump blood through the blood circuit and blood filter; and (iv) a control unit operable with the dialysis fluid preparation structure and the blood pump, the control unit programmed to prepare a gas generation fluid different than the dialysis fluid for the extracorporeal therapy treatment, wherein the gas generation fluid generates carbon dioxide (“CO.sub.2”) gas, and wherein the CO.sub.2 gas is used to prime the blood circuit including the blood filter.

Simple-to-use systems, methods, and devices for priming replacement blood treatment devices, for swapping the blood treatment devices out, for replacing swapped-out blood treatment devices, and other related operations are described. In embodiments, a blood treatment device can be primed while a therapy is still running. When the replacement blood treatment device is needed, the therapy can be stopped momentarily (less than a minute) for the rapid and safe swap of the blood treatment device. Blood loss can be minimized. The down time from therapy can be minimized.