An insertion system for inserting a sensor into fatty tissue, comprising an insertion device and an insertion needle containing a sensor, wherein the insertion device comprises a holder for the insertion needle, and a piercing mechanism so as to move the holder, with the needle held by the same, in a feed direction for a puncture. The piercing mechanism changes the feed direction during the puncture so that, at the end of the puncture, an insertion needle held by the holder is oriented obliquely or perpendicular to the initial feed direction. Also provided are methods for controlling a needle moved by an insertion device.
