Manually-operated compressional optical coherence elastography with effective aperiodic averaging: demonstrations for corneal and cartilaginous tissues

Compressional elastography in optical coherence tomography (OCT) is based on relating the sought spatial distribution of stiffness with initially reconstructed strain distribution by comparing OCT scans of the tissue in reference and deformed states. To ensure acceptable signal-to-noise ratio, tissue straining with auxiliary periodic sources (e.g. piezo-actuators) allowing for periodic averaging is often used. However, for many practical biomedical applications and translation of optical coherence elastography (OCE) to clinics, realization of strain mapping in manually-operated regime is of key importance. Here, we demonstrate possibilities to realize manually-operated OCE, in which effective averaging does not require periodic actuation. Advantages of the proposed approach are discussed including possibilities of obtaining quantitative nonlinear stress–strain curves and estimating high-contrast stiffness differences. Experimental demonstrations are given using cornea and cartilage samples representing fairly 'soft' and 'stiff' tissues, respectively.