A portable therapeutic apparatus and a method for controlling the apparatus are provided. In one aspect the apparatus and the method can be implemented using a patch unit (100, 200) removably attachable to a cradle unit (20), said cradle unit removably attachable to the body of the patient; a position detector (1000) comprising a patch portion (900) and a cradle portion (800), said patch portion coupled to the patch unit, said cradle portion coupled to the cradle unit; a processor adapted for receiving a position indication signal from the at least one position detector, said position indication signal corresponding to a physical proximity of the patch portion to the cradle portion, and, wherein the portable therapeutic apparatus is adapted for at least one therapeutic function selected from the group consisting of delivering a therapeutic fluid into the body of the patient and sensing a bodily analyte.