The operating principle of the peristaltic pump is very simple. The fluid is transported by alternating extrusion and release of the pump tube. A section of the pump tube between the two rollers forms a pillow fluid. The size of the pillow depends on the inner diameter of the pump tube and the geometric size of the roller. The flow depends on the product of the speed of the pump head, the volume of the pillow and the number of "occipital" numbers generated by each turn of the roller.