INFUSION PUMP WITH DISPOSABLE CASSETTE

摘要

INFUSION PUMP WITH DISPOSABLE CASSETTE An infusion pump incorporates a cassette formed by bonding of two substantially flat sheets. The fluid to be infused to the patient comes into contact only with the cassette. The cassette includes first and second flexible sheets which define a pumping chamber therebetween. The infusion pump is provided with a pumping member having a hub and a plurality of petal-shaped sections extending radially outward therefrom and pivotal relative thereto. A stepping motor can be operated to move the pumping member against the second flexible sheet to decrease the volume of the pumping chamber and pump fluid to the patient. A load cell monitors the force exerted by the stepping motor on the hub. An outlet restriction valve is electronically controlled by a second stepping motor in response to the pressure sensed by the load cell to control pumping to a predetermined pressure. The pressure can be selectively varied which permits the use of a low pressure at low flow rates to decrease the time necessary to detect an occlusion in the output line.