Quantification of skin aging by three-dimensional measurement of skin surface contour

In order to quantify the skin aging, the skin surface contours for 72 male subjects from in his 20's to in his 60's were measured three-dimensionally and analyzed by 2D Fourier transform method. The measuring part of the body was the back of the hand. Results of the 3D measurements showed that the pattern composed of longitudinal, oblique, and transverse ridges on the skin surface changed with age. Results of the 2D Fourier analysis of skin surface contours showed that the skin surface contours of young male subjects included much of high spatial frequency components while the skin surface contours of aged male subjects included low spatial frequency components mainly. The aging parameter for 72 male subjects, which expressed the skin aging quantitatively, was calculated by summing up the Fourier coefficients within a specified area on the X-Y spatial frequency plane. The aging parameter decreased with age. However the aging parameter showed wide scattering. The wide scattering of the aging parameter can be removed by applying the high pass digital filter to the skin surface contours.