Optical coherence elastography of 3D bilayer soft solids using full-field and partial displacement measurements

Abstract

Characterizing nonhomogeneous elastic property distribution of soft tissues plays a crucial role in disease diagnosis and treatment. In this paper, we will apply the optical coherence elastography to reconstruct the shear modulus elastic property distribution of a bilayer solid. In the computational aspect, we adopt a well-established inverse technique that solves for every nodal shear modulus in the problem domain (NO method). Additionally, we also propose a novel inverse method that assumes the shear moduli merely vary along the thickness of the bilayer solid (TO method). The inversion tests using simulated data demonstrate that TO method performs better in reconstructing the shear modulus distribution. Further, we utilize the experimental data obtained from the optical coherence tomography to reconstruct the shear modulus distribution of a bilayer phantom. We observe that the quality of the reconstructed shear modulus distribution obtained by the partial displacement measurement is better than that obtained by the full-field displacement measurement. Particularly, merely using the displacement component along the loading direction significantly improves the reconstructed results. This work is of great significance in applying optical coherence elastography (OCE) to characterize the elastic property distribution of layered soft tissues such as skins and corneas.