The present invention relates to a novel type of tubular insert 28 for connecting an extra corporeal circuit 26 to a peristaltic pump 22. This tubular insert 28 comprises a loop 32 formed by a tube portion 20 the loop 32 comprises a curve 38 which extends around an axis. The tube 20 which forms the curve 38 has an oval cross section with a major axis and a minor axis perpendicular to each other where the major axis is longer than the minor axis . Finally in the tubular insert 28 according to the invention the minor axis of each cross section of the tube 20 along the curve 38 is parallel to the axis The invention further relates to a method for producing the tubular insert 28 and to a peristaltic pump 22 suitable for operating wi th tubular inserts according both to the invention and to the prior art.
