Fig. 2
From: Reverberant 3D optical coherence elastography maps the elasticity of individual corneal layers
Comparative analysis of Rev3D-OCE and the Lamb wave method using numerical simulations. Numerical simulation results of a 3D finite element model of cornea composed of four layers with differentiated linear elastic materials distributed monotonically from stiffer to softer: A, B, C, and D, corresponding to 2.5, 2, 1.3, and 0.8 m s−1 of shear wave speed. a Cornea model subjected to sinusoidal steady-state excitation of 2 kHz (Rev3D-OCE method) through eight circular-distributed force heads. Reverberant patterns extracted in each layer depict differentiated wavelength and are transformed into shear wave speed values using Eqs. (1)–(3) as plotted in the shear/Lamb speed vs. depth diagram. b Cornea model subjected to axisymmetric Gaussian (σ = 0.3 mm) transient (t = 1 ms) force (Lamb wave method) producing a cylindrically-shaped Lamb wave propagation. Dispersion curves (Lamb speed vs. frequency) are calculated for each layer. Dispersion curves produced from a transient (t = 0.5 ms, σ = 0.3 mm) force are also included. The Fourier transform of both temporal excitations (t = 0.5 ms, and t = 1 ms) measured in the model are also shown. Given a selected frequency (1 kHz), depth-dependent Lamb wave speed profile is plotted in the shear/Lamb speed vs. depth diagram of (a) for further comparison
