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 to 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 pumping cassette including a housing having at least two inlet fluid lines and at least two outlet fluid lines. At least one balancing pod within the housing and in fluid connection with the fluid paths. The balancing pod balances the flow of a first fluid and the flow of a second fluid such that the volume of the first fluid equals the volume of the second fluid. The balancing pod also includes a membrane that forms two balancing chambers. Also included in the cassette is at least two reciprocating pressure displacement membrane pumps. The pumps are within the housing and they pump the fluid from a fluid inlet to a fluid outlet line and pump the second fluid from a fluid inlet to a fluid outlet.

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.

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.

Described are fluid pumping and fluid handling systems, which may be suitable for use in medical devices, such as artificial or extracorporeal blood pumping systems. The systems can include a dual housing configuration for pneumatic actuation comprising a main housing containing a pump cassette comprising a pneumatically actuated pump and pneumatically actuated valves. The pump can include a pump actuation chamber and pump pneumatic port, and the valves can each include a valve actuation chamber and valve pneumatic port. Connecting tubes can be used to fluidly connect the pump actuation ports and valve actuation ports to a tube-support housing having a first side receiving one end of each connecting tube and a second side providing a pneumatic interface arranged to connect to an array of pneumatic receptacles on a base unit of the system to facilitate easy, compact and accurate pneumatic interconnection between the pump cassette and the base unit.

Described are fluid pumping and fluid handling systems, which may be suitable for use in medical devices, such as artificial or extracorporeal blood pumping systems. The systems can include a dual housing configuration for pneumatic actuation comprising a main housing containing a pump cassette comprising a pneumatically actuated pump and pneumatically actuated valves. The pump can include a pump actuation chamber and pump pneumatic port, and the valves can each include a valve actuation chamber and valve pneumatic port. Connecting tubes can be used to fluidly connect the pump actuation ports and valve actuation ports to a tube-support housing having a first side receiving one end of each connecting tube and a second side providing a pneumatic interface arranged to connect to an array of pneumatic receptacles on a base unit of the system to facilitate easy, compact and accurate pneumatic interconnection between the pump cassette and the base unit.

Improvements in fluid volume measurement systems are disclosed for a pneumatically actuated diaphragm pump in general, and a peritoneal dialysis cycler using a pump cassette in particular. Pump fluid volume measurements are based on pressure measurements in a pump control chamber and a reference chamber in a two-chamber model, with different sections of the apparatus being modeled using a combination of adiabatic, isothermal and polytropic processes. Real time or instantaneous fluid flow measurements in a pump chamber of a diaphragm pump are also disclosed, in this case using a one-chamber ideal gas model and using a high speed processor to obtain and process pump control chamber pressures during fluid flow into or out of the pump chamber.

Improvements in fluid volume measurement systems are disclosed for a pneumatically actuated diaphragm pump in general, and a peritoneal dialysis cycler using a pump cassette in particular. Pump fluid volume measurements are based on pressure measurements in a pump control chamber and a reference chamber in a two-chamber model, with different sections of the apparatus being modeled using a combination of adiabatic, isothermal and polytropic processes. Real time or instantaneous fluid flow measurements in a pump chamber of a diaphragm pump are also disclosed, in this case using a one-chamber ideal gas model and using a high speed processor to obtain and process pump control chamber pressures during fluid flow into or out of the pump chamber.

An implantable pump includes a rigid housing with an oblate spheroid shape and having an inner chamber divided by a movable elastomeric membrane into a gas sub-chamber which is connectible through a drive line to an external pneumatic source, and a blood sub-chamber which is connectible through a graft assembly to an anatomical heart. The housing includes a blood port opening oriented at an angle and at the upper apex of the housing and connected to the blood sub-chamber, and a gas port opening to the gas sub-chamber that is situated at a lower apex of the housing. The pump is provided with a drive line that includes a gas conduit and a heart sensor, the drive line connectible to a drive system that is capable of delivering gas flow through the drive line gas conduit in response to signals driven by the heart sensor.

An implantable pump includes a rigid housing with an oblate spheroid shape and having an inner chamber divided by a movable elastomeric membrane into a gas sub-chamber which is connectible through a drive line to an external pneumatic source, and a blood sub-chamber which is connectible through a graft assembly to an anatomical heart. The housing includes a blood port opening oriented at an angle and at the upper apex of the housing and connected to the blood sub-chamber, and a gas port opening to the gas sub-chamber that is situated at a lower apex of the housing. The pump is provided with a drive line that includes a gas conduit and a heart sensor, the drive line connectible to a drive system that is capable of delivering gas flow through the drive line gas conduit in response to signals driven by the heart sensor.