Research And Implementation Of The Infusion Control/Monitoring Apparatus

Vein infusion is a most common therapy method in the clinical. In practice, the nurses adjust the speed of infusion by hand through observation and experience, but the effect is not very good, because the too fast infusion speed can make the patients discomfort, even lead to bad effects, and the slow infusion speed have a bad effect on treatment. Although the infusion pumps which can control the speed and dosage of medicine accurately based on the given requirements, and is an effective way to solve the speed of infusion, the price is so high that it is only suit for emergencies and critical care. It is so hard to be used widely that it can not meet the needs of medical stuff and patients.Therefore, the paper has a research on the distribution infusion control/monitoring apparatus. This system consists of a PC and some monitors. The PC settled in the nurse's office, and the monitors can be placed in the infusion room. The monitors are used to measure the infusion speed and send the information of the infusion speed to the PC. The PC examines, controls and shows every bed in different rooms. If the infusion speed is out of the range that is given or the process is finished, both the PC and the monitor alarm with sound and light to make the nurse to take actions timely.The infusion control/monitoring apparatus has single pattern and online pattern, the former can control and monitor the whole process of the vein infusion and the later may be used as the subsystem of the distributed infusion control/monitoring system in the process of vein infusion.The hardware of the infusion control/monitoring apparatus mainly includes MSP430F149, power circuit, interface of droplet detection circuit, keyboard circuit, alarm circuit, data receive/send circuit, step motor control circuit, JTAG interface circuit, and liquid crystal display interface etc. MSP430F149 receives the rectangle pulse that photoelectric switches outputted via the external interrupt wire, computes the speed of infusion using the pulses, makes adjustments compared with the speed set before, in the meantime, predicts the left time of infusion and displayed the result on the LCD, then transmitted the information of infusion to the PC through nRF401 module. Step motor control institution is a wooden involutes top which presses and looses infusion pipe to control infusion speed driven by step motor. The software of infusion control/monitor apparatus is composed by main program, system boot module, liquid crystal module, and step motor module, interrupt service of droplet detection, interrupt service of the timer and interrupt service of keyboard.Moreover, by analyzing the reasons why infusions control/monitoring apparatus has been disturbed, the system adopts the PCB anti-jamming hardware and watchdog software to resist the disturbance.It is demonstrated that the measurement error of monitor is±2 drop per minutes, the error of rest time is +5 minutes and alarm can be started timely through the simulation test of infusions control/monitoring apparatus, which basically meets the requirements of medical staff about infusions speed control/monitoring clinically.