Computer compatible patient contour plotter

The use of a compact, mobile, relatively inexpensive electromechanical patient‐contouring mechanism is described. The system utilizes a Numonics Model 224 graphics digitizer suspended over the patient. The digital X and Y coordinates of the patient contour in either of multiple, parallel transverse, or sagittal planes are inherently accurate to within ±0.25 mm over a total reading area of 60×90 cm. Display features include the interface to an analog 11‐in.×17‐in. X–Y plotter with a variable scale‐down factor for those contours which would otherwise be larger than the plotting surface. The system is easy to use and may also be readily interfaced for on‐line entry of patient contours to calculator‐ or minicomputer‐based treatment‐planning systems.