Method and device for detecting blocked condition in a tube of a liquid infusion pump

摘要

A detector for a blocked condition in a tube of a liquid infusion pump includes a moveable shaft which is kept in contact with the outer wall of a flexible tube for transporting a liquid therethrough and moves according to the changes in the outer diameter of the tube corresponding to changes in the internal pressure of the liquid. A magnet core is affixed to this shaft and affects the inductance of a solenoid coil which is affixed at a fixed position. A blocked condition in the tube is detected by monitoring the change in the inductance of this coil.