Key points are not available for this paper at this time.
A system is described which monitors a point in space and displays discontinuities of radiodensity as the point is moved in a scanning fashion through a plane. A high degree of isolation of this point from other points in the plane is achieved by putting these changes in radiodensity of the moving point into an electrical form which allows them to be separated from all other discontinuities within the plane.
William H. Oldendorf (Sun,) studied this question.