Optical advantages of using a moire topographic instrument on the living body

A moire topographic instrument has been successfully used in a clinic for making topograms of the living body. This instrument has three optical advantages: (1) its sensitivity can be adjusted; (2) the gratings adopt a suitable depth and the measurable depth is 150 mm; (3) it has smooth grating lines with outfocusing for eliminating noise. Eighty-five percent of the moire topograms of a scoliotic patient agree with the x rays.