Abstract:
A pump cassette is disclosed. The pump cassette includes a housing having at least one fluid inlet line and at least one fluid outlet line. The cassette also includes at least one reciprocating pressure displacement membrane pump (820) within the housing. The pressure pump pumps a fluid from the fluid inlet line to the fluid outlet line. A hollow spike (902) is also included on the housing as well as at least one metering pump (830). The metering pump (830) is fluidly connected to the hollow spike (902) on the housing and to a metering pump fluid line. The metering pump fluid line is fluidly connected to the fluid outlet line.
Abstract:
An apparatus and method are disclosed for detecting the disconnection of a vascular access device such as a needle, cannula or catheter from a blood vessel or vascular graft segment. A pair of electrodes is placed in direct contact with fluid or blood in fluid communication with the vascular segment. In one embodiment, the electrodes are incorporated into a pair of connectors connecting arterial and venous catheters to arterial and venous tubes leading to and from an extracorporeal blood flow apparatus. Wires leading from the electrodes to a detecting circuit can be incorporated into a pair of double lumen arterial and venous tubes connecting the blood flow apparatus to the blood vessel or vascular graft. The detecting circuit is configured to provide a low-voltage alternating current signal to the electrodes to measure the electrical resistance between the electrodes, minimizing both the duration and amount of current being delivered. Detection of an increase in electrical resistance between the electrodes exceeding a pre-detepnined threshold value may be used to indicate a possible disconnection of the vascular access device.
Abstract:
Pumping cassettes (500, 600, 700) are disclosed. Each cassette includes a housing, at least one fluid inlet and at least one fluid outlet as well as at least one reciprocating pressure displacement membrane pump (602, 604) in fluid relation to the cassette. The balancing cassette includes at least one balancing pod (706, 708) in fluid connection. The mixing cassette includes at least one mixing chamber in fluid connection. The system includes a mixing cassette (500), a balancing cassette (700), and an outer or middle cassette (600) fluidly connected to the mixing cassette and the balancing cassette and at least one pod. The mixing cassette is fluidly connected to the middle cassette by at least one fluid line and the middle cassette is fluidly connected to the balancing cassette by at least one fluid line. The at least one pod is connected to at least two of the cassettes wherein the pod is located in an area between the cassettes.
Abstract:
There is disclosed herein 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.
Abstract:
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.
Abstract:
Pumping cassettes are disclosed. Each cassette includes a housing, at least one fluid inlet and at least one fluid outlet as well as at least one reciprocating pressure displacement membrane pomp in fluid relation to the cassette. The balancing cassette includes at least one balancing pod in fluid connection. The mixing cassette includes at least one mixing chamber in fluid connection. The system includes a mixing cassette, a balancing cassette, and an outer or middle cassette fluid! y connected to the mixing cassette and the balancing cassette and at least one pod. The mixing cassette is flαidly connected to the middle cassette by at least one fluid line and the middle cassette is fluidiy connected to the balancing cassette by at least one fluid line. The at least one pod is connected to at least two of the cassettes wherein the pod is located in an area between the cassettes.
Abstract:
Hemodialysis dialysis systems comprising a dialysis unit and user interface unit adapted to display safety critical information related to a dialysis process 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 device (s), 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.
Abstract:
A drain cassette for a dialysis unit has a fluid channel between venous and arterial connection ports, and a valve may controllably open and close fluid communication between a drain outlet port and the venous connection port or the arterial connection port. A blood circuit assembly and drain cassette may be removable from the dialysis unit, e.g., by hand and without the use of tools. A blood circuit assembly may include a single, unitary member that defines portions of a pair of blood pumps, control valves, channels to accurately position flexible tubing for an occluder, an air trap support, and/or other portions of the assembly. A blood circuit assembly engagement device may assist with retaining a blood circuit assembly on the dialysis unit, and/or with removal of the assembly. An actuator may operate a retainer element and an ejector element that interact with the assembly.