Patent ID: 6165154
Filing Date: 2000-12-26
Classification: A61M,F04B,F16K,G01N

Abstract:
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,wherein 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.