ABSTRACT
The object of this work was to develop a methodology for a three-dimensional reconstruction and an analysis of human trunk surface. This kind of methodology has application in studies of postural analyses and respiratory movements, among others. A structured slide is projected onto the trunk surface. The surface under this projection is registered by video camcorders and this sequence of images are converted to digital riles for computational processing. By using dedicated software, a set of light points on the surface is measured and their three-dimensional coordinates are reconstructed. This set of points is then projected onto a convenient plane of projection. An approximation of an analytical representation of the surface is prepared as a function f(U,V), which is assessed lust for the points (u, v) located in the outline of the projected surface. This representation allows forms of surface topological analysis such as: a) estirmate of the surface area, perimeter, among others: b) attainment of contour lines over it; c) orientation of the surface by determining normal vectors. Two application-tests of the methodology were conducted. 1) The external surface of a cylindrical object was reconstructed. The results of this appiication have indicated a satisfactory accuracy of the methodology in estimating the surface area (< 2 error). 2) The posterior surface of a subject's trunk was reconstructed as an application assessment of this methodology in human beings. The results of this study show that the developed methodology provides a reliable and detailed representation of human body surfaces, enabling the obtainment of anatomical and biomechanical information for studies and analyses of the human body.
