Measurement of all orthogonal components of displacement in the volume of scattering materials using wavelength scanning interferometry

Elastic stiffness characterization using three-dimensional full-field deformation obtained with optical coherence tomography and digital volume correlation

“…Even though most phase-sensitive OCT elastography systems have so far focused on phase measurements with only axial sensitivity, a new system with sensitivity to all displacement components has been recently developed based on a wavelength scanning OCT system using multiple illumination directions and a single observation direction. 49 In this work, strain was evaluated with a centered finite difference operator applied to the displacement field. No displacement smoothing was used before strain calculation in order to achieve maximal spatial resolution with a view to further studies on thin biological tissues such as the vertebrate eye cornea.…”

Tomographic sensing of displacement fields

“…In order to separate the microstructure reconstructions in the frequency domain, a different carrier frequency is used for each illumination direction by simply setting different optical delays betwe en them and the reference beam -see Ref. [8] for details. Figure 1 illustrates the optical setup: Light from a tunable laser (TSL-510 Type A, Santec Ltd., tunable from 1260nm to 1360nm in ~0.011nm steps ) is split with a 24 fibre splitter in three illumination and one reference beams.…”

“…In the optical domain, optical coherence tomography (OCT) can also provide depth -resolved displacement measurements either by using phase information [4,5], polarization sensitive detection and material photoelasticity [6], or detecting changes in the microstructure using digital volume correlation, known as OCT elastography [7]. In this paper, a novel approach is presented in which all the orthogonal components of the displacement field are measured simultaneously using wavelength scanning interferometry (WSI) [8]. Each voxel in the digital reconstruction of the sample behaves effectively as a multicomponent displacement sensor.…”

Depth-Resolved Full-Field Measurement of Corneal Deformation by Optical Coherence Tomography and Digital Volume Correlation

“…deformation in anisotropic material) as well as the prerequisite for the identification of 3D constitutive parameters using inversion methods such as finite element model updating (FEMU) [41][42][43], the virtual fields method (VFM) [44][45][46][47] or the constitutive compatibility method (CCM) [48], measurement of the depthresolved 3D deformation is required to avoid simplistic assumptions of isotropy or depth independent properties. This can be implemented by either 1) using a system with sensitivity to all deformation components based on a wavelength scanning OCT system with multiple illumination directions as introduced by Chakraborty and Ruiz [49] or 2) using a single channel OCT system to reconstruct the corneal internal structure, followed by digital volume correlation (DVC) to provide deformation fields with all displacement components. DVC is the 3-D extension of the widely applied DIC used to measure surface deformations.…”