The present invention relates generally to motion-based, sterile image control system for medical care. Accordingly, the system includes: a) a motion based system capable of providing a touch-free user interface for digital image projections; b) a body joint registration of user in communicating with a defined gesture through the motion based system; wherein the motion based system enables the user to execute tasks including image selection, zoom in, and zoom out, translation, rotation, reset of the images; such that the all the interaction commands are mapped to various gestures in controller free system interface, by interactive modification of transfer function without going into complex calibrations; and wherein all the commands are executed by formulating distance maps of the hand and arm gestures signalled from a distance without touching anything.