초록 ▼

A cassette for controlling the flow of IV fluid from a patient to a source. The cassette preferably includes, along the fluid passage through the cassette, first and second membrane-based valves (6, 7) on either side of a pressure-conduction chamber (50), and a stopcock-type valve (20). The stopcock

A cassette for controlling the flow of IV fluid from a patient to a source. The cassette preferably includes, along the fluid passage through the cassette, first and second membrane-based valves (6, 7) on either side of a pressure-conduction chamber (50), and a stopcock-type valve (20). The stopcock valve is preferably located downstream of the second membrane-based valve (7), which is preferably located downstream of the pressure-conduction chamber (50). The membrane defining the valving chamber of the second membrane-based valve (7) is preferably large and resilient, so that the valving chamber (75) may provide a supply of pressurized intravenous fluid to the patient, when the valve is closed and the stopcock valve provides a restriction downstream of the valve. The pressure-conduction chamber (50) preferably has a membrane (41) that is stable in the empty-chamber position but relatively unstable in the filled-chamber position.

대표청구항 ▼

[ What is claimed is:] [1.] A method for controlling the flow of intravenous fluid from a source to a patient, the method comprising:providing a cassette having a rigid housing, a membrane disposed adjacent the rigid housing, the rigid housing and the membrane defining a pressure-conduction chamber,

[ What is claimed is:] [1.] A method for controlling the flow of intravenous fluid from a source to a patient, the method comprising:providing a cassette having a rigid housing, a membrane disposed adjacent the rigid housing, the rigid housing and the membrane defining a pressure-conduction chamber, rein a pressure-conduction chamber portion of the rigid housing is generally dome-shaped, the membrane has a filled-chamber position, in which position the pressure-conduction chamber is substantially at its greatest volume, and an empty-chamber position, in which position the pressure-conduction chamber is substantially at its smallest volume, and in which position the membrane rests against the rigid housing and assumes the dome shape of the pressure-conduction chamber portion of the rigid housing, the membrane having an interior surface that comes into contact with the fluid and an exterior surface, and wherein the membrane includes a tab extending from the exterior surface from a point adjacent where the rigid housing meets the membrane;providing a control unit for receiving the cassette, the control unit having an actuator for urging the tab towards the rigid housing;placing the cassette into the control unit;causing the actuator to urge the tab towards the rigid housing so as to lift a portion of the membrane away from the rigid housing; andalternately dispensing fluid into and out of the pressure-conduction chamber.