Improvements in speckle tracking algorithms for vibrational analysis using optical coherence tomography.

We report on improvements in speckle tracking algorithms for analyzing subsurface vibrations using an optical coherence tomography system. Our technique uses axial deconvolution and linear interpolation of depth scans before using cross-correlation-based speckle tracking. We applied this method on M-mode images of a test sample and on wrist pulses to perform depth-resolved measurements of displacement, velocity, and frequencies of vibrations. Speckle pattern displacements and features spanning 0.5 pixels were tracked clearly. Extension of this technique to two dimensions can provide improved performance in the field of optical coherence elastography.