Working principle of infusion set

The general infusion set can be composed of liquid propulsion device, digital display, control part and alarm part. Push device can be divided into peristaltic type, rolling type, piston type and screw needle cylinder type. At present, peristaltic type is mostly used for infusion. It is a row of pressers successively squeeze and release the rubber strip in order to promote the liquid. In this way, the presser foot is pressed and released just like the wriggling mode. Accelerating the peristalsis frequency can increase the liquid flow rate. Micro syringe uses screw to change rotary motion into linear motion. There is a linear grating moving with the screw on one side, which can accurately measure the flow rate with the accuracy of 0.1ml/h. The power of the driving device is generally hollow cup motor, which has small moment of inertia and is easy to control. The motor voltage adopts DC pulse, and there is a grating on the motor shaft to control the rotation of the motor.

Because the liquid is directly input into the patient's vein, it is related to the patient's safety to a great extent. Therefore, there must be an alarm system to stop the infusion in time in case of any abnormal situation, and send out the light alarm and call alarm, which is timely handled by the medical staff. The alarm can have pressure alarm for whether the infusion tube is blocked, and can have liquid alarm for whether the knowledge liquid is used up and the bubble alarm in the infusion tube. The working state of all functions is executed by microprocessor.