A method of turning a medical device (44), having a magnetically responsive element (46) associated with its distal end, at an operating point (42) within an operating region (40) inside a patient's body from an initial direction to a desired final direction, through the movement of at least one external source magnet (38). The at least one external source magnet (38) is moved in such a way as to change the direction of the distal end of the magnetic medical device (44) from the initial direction to the desired final direction without substantial deviation from the plane containing the initial direction and the desired final direction.