A control system for an intravenous feed tube is provided that functions by sensing weight changes with respect to time, i.e., dw/dt, of an intravenous solution supplied to a patient, the solution being maintained as a free hanging load. The weight changes are detected by strain gauge sensors, and then...http://www.google.com.hk/patents/US4457750?utm_source=gb-gplus-share專利 US4457750 - Microprocessor controlled intravenous feed system
