Positioning systems and related methods

Apparatus for correcting positional deviations of at least one area of a subject along one or more subject position axes. The apparatus comprises: (a) a distance-measuring component which employs a phase difference between two oscillatory signals to measure and monitor changes in the position of a subject area; (b) storage means for storing information corresponding to the prior and later spatial positions of the area; (c) a support upon which the subject may lie; (d) calculating means for determining, from the stored information, a deviation in spatial position of the area from its prior spatial position along the first subject position axis and translatory motion of the area which will restore the area to its prior spatial position along the first subject position axis, and generating at least one repositioning signal which transmits information corresponding to the translatory motion of either the support or the area necessary to restore the area to its prior spatial position along the first subject position axis; and (e) a position controller which can at least reposition the support in response to the repositioning signal.