Abstract: A peristaltic infusion pump tube segment comprises a first tube portion having a surrounding wall adapted for an upstream occlusion detection, a second tube portion downstream of said first tube portion and adapted to be temporally engaged by an engagement structure, wherein said second tube portion comprises a surrounding wall being at least partly thicker than the wall of said first tube portion and made of an elastic material which allows said second tube portion to be essentially reformed at those portions which are currently not subject to the engagement by the engagement structure, a third tube portion downstream of said second tube portion and having a surrounding wall adapted for an air in line detection, and a fourth tube portion adapted for a downstream pressure detection. The peristaltic infusion pump tube segment is provided in an infusion pump device which comprises a pump mechanism configured as a peristaltic mechanism.