A device for introducing a liquid (e.g., insulin) into tissue of a subject (e.g., a mammal, such as a human) in need of the liquid. The device includes a cannula having a distal tip. A cannula positioner adjustably (and incrementally) controls a position of the cannula after introduction subcutaneously into a subject. A cannula positioner body allows adjustable support of the cannula and the cannula positioner and may be worn by the subject. The cannula positioner includes a cannula position control member that is adapted to be driven (e.g., longitudinally) to advance or retract the cannula so that a subcutaneous position of the distal tip is changeable among a plurality of locations over a period of at least four days, without removal of the cannula from the subject.
