Fig. (4) Displacement patterns in the characteristic positions. λ = 1.45 mm, and the maximum distance for the propagation = 4.35 mm. In addition to the characteristic positions in each parameter, zd, zφ1, zφ2, and zθ, the representative positions of the truncus chorii, rami chorii and ramuli chorii appear: zt, zr and zrl, which are the middle z coordinates of the truncus chorii, rami chorii, and ramuli chorii, respectively.