Compression paddle deformed front-edge profiles. Three one-dimension compression paddle profiles along y-direction at × = 20 are shown, which were estimated by modifying Eq. (11) to analyze bulge along the y-direction near the paddle front perimeter. The paddle perimeter flex is less than 0.4 mm. The compression forces (dN) were 4.0, 6.0, and 8.0 from top to bottom, respectively.