The device comprises means for taking a height measurement (H) and a plurality of circumference measurements (b, c, g) on the limb of the patient at different predetermined z-positions (zb, zc, zg). A first data file includes the coordinates (X.sub.0, Y.sub.0, Z.sub.0) of a first mesh of points (24) representative of the morphological characteristics of a reference limb, these points being distributed over the surface of the reference limb along a succession of outlines (26) defined at different successive Z-positions. Morphology generator means recalculate the coordinates of the first mesh of points as a function of the height measurement (H) and of the circumference measurements (b, c, g) in such a manner as to produce a second data file comprising the coordinates (x, y, z) of a second mesh of points (52) representative of morphological characteristics of the patient's limb.