91 results about "Dialysate flow" patented technology

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.

A number of improvements relating to methods and apparatuses for kidney dialysis are disclosed. These include checking of dialysate bypass status using flow measurement; using a flow sensor to confirm the absence of ultrafiltration during bypass; automatic testing of ultrafiltration function by removal of a discrete volume from a portion of the dialysate flow path coupled with a pressure test of that part of the flow path; using a touch screen user interface; bar graph profile programming of ultrafiltration, sodium, and bicarbonate parameters; using a RAM card to upload treatment instructions to, and to download treatment data from, the machine; automatic setting of proportioning mode (acetate or bicarbonate) based on connections of concentrate lines; predicting dialysate conductivity values based on brand and formulation of concentrates; minimizing no-flow dead time between dialysate pulses; initiating operation in a timed mode from a machine power-off condition; preserving machine mode during machine power-fail condition; calibration scheduling and reminding; automatic level adjusting; and blood leak flow rate detecting.

Hemodialysis dialysis systems are disclosed. Hemodialysis systems of the invention may include a dialysate flow path including a balancing circuit, a mixing circuit, and / or a directing circuit. The circuits may be defined within one or more cassettes. The fluid circuits may be at least partially isolated, spatially and / or thermally, from electrical components of the system. A gas supply may be provided in fluid communication with the dialysate flow path and / or the dialyzer to urge dialysate through the dialyzer and blood back to the patient. The hemodialysis systems may include fluid handling devices, actuated using a control fluid, optionally delivered using a detachable pump. Fluid handling devices may be generally rigid and of a spheroid shape, optionally with a diaphragm dividing the device into compartments.

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.

A method of calibrating a dialysis machine to determine the volume of a dialysate flow path of the machine including a dialysate preparation tank includes the steps of introducing a known quantity of electrically conductive chemicals into the dialysate preparation tank, filling the dialysate solution flow path with water, mixing the chemicals with water to form a solution, measuring the conductivity of the solution, calculating the system volume (Vsys) according to the relation: Vsys=M / (a1r+b1) where M is the mass in grams of the chemicals, a1 and b1 are a coefficient of linearity and a constant of linearity, respectively, for the chemicals and r is the measured conductivity of the solution.

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. Dialysis systems may include a safety system utilizing a field programmable gate array (FPGA) that monitors at least conductivity and temperature of dialysate in the flow circuit upstream of a dialyzer and enters a fail-safe state if the measured conductivity is outside of a range of values. The FPGA may be verified to be operating properly by exposing sensors in fluid paths to temperatures or conductivities that are outside pre-determined permissible ranges of values, and confirming that the FPGA safety system enters a fail-safe state in response to the temperatures or conductivities. The FPGA may be configured to monitor an amount of ultrafiltration fluid withdrawn from a patient during dialysis treatment and to enter a fail-safe state if a maximum amount is exceeded.

The application is directed to an extracorporeal blood processing system capable of using dialysate to prime the system. A plastic molded compact manifold supports molded blood and dialysate fluidic pathways along with relevant sensors, valves and pumps. The compact manifold is also disposable in one embodiment and can be detachably installed in the dialysis machine. A two-way valve in the manifold is used to direct the dialysate flow through the blood circuit to prime the circuit for use in treatment.