Float method: when using, connect the inlet connecting tube to the infusion bottle (the outlet connecting tube and infusion tube are integrated). At the beginning of infusion, the liquid medicine enters the lumen with a magnetic float, which floats on the liquid surface, squeezes the lumen, and adjusts the height of the liquid surface in the lumen to make the float higher than the alarm control point.
Working principle:
Because infusion alarm is of great significance to hospitals and patients, there are many researches in this field. In the past 10 years, there were more than 100 patents, including electrode insertion method, float method, capacitance method, microwave method, photoelectric method and other principles. Mainly introduce the following principles:
Using mechanical and geometric principles, this principle is to detect the remaining amount of liquid medicine by weighing. The spring is pulled up by force, and objects with different masses act on the spring, and the length will change differently, thus subtly modifying the spring scale.
Hang the infusion bottle on the hook of the spring tensiometer, and the spring is pulled down. With the decrease of infusion volume in the bottle, the quality of the retractor decreases, and the spring gradually retracts until the final quality is close to the empty bottle, and the alarm device starts to alarm.
Capacitance: according to the phenomenon that the dielectric constant will change when there is liquid or no liquid in the infusion tube, the infusion tube is clamped between two capacitor plates, and whether there is liquid in the infusion tube can be judged by measuring the change of capacitance. When the liquid drops out or the infusion is abnormal, the channel will be automatically cut off and give an alarm, so as to achieve the purpose of monitoring the infusion.