When the user selects the distance measurement tool, one or more rectangles appear on the image. Each one of these rectangles represents a calibrated region. The active region has a green color and the inactive regions have a red color. Within the active (green) region the mouse cursor has a cross shape, and within the inactive (red) region has an arrow shape. The user can take measurements in the active region.
By clicking the right mouse button, a pop-up menu appears and allows the user to select the active region.
By selecting the menu command "View US Region Details...", a dialog box appears and it displays the type, the units and the delta of the active region.
The user can easily check the accuracy of the measurements by taking the same measurement in the ultrasound machine and in the program.
