Assessing Tissue Biomechanical Properties with Noncontact Dynamic Optical Coherence Elastography


This dissertation reports the development of noncontact techniques to quantify the biomechanical properties of various tissues utilizing optical coherence elastography. These techniques are critical for screening, detection, and monitoring of disease onset and progression as well as evaluating the effectiveness of various therapeutic procedures. The dissertation is divided into two major sections: 1) analyzing the localized dynamic deformation and 2) analyzing elastic wave propagation to quantify tissue biomechanical properties. Each of these sections is further divided. The localized dynamic tissue deformation analysis section has two sub-sections: a) real-time visual feedback and biomechanical assessment of dermal filler injections and b) evaluating the changes in local cardiac biomechanical properties after myocardial infarction. The elastic wave propagation analysis section has seven sub-sections: a) evaluating the changes in corneal biomechanical properties due to riboflavin/UV-A corneal collagen cross-linking, b) comparing the changes in corneal biomechanical properties induced by riboflavin/UV-A and rose-bengal/green light collagen cross-linking, c) quantifying the effects of tissue hydration on the stiffness of the cornea, d) assessing the elastic anisotropy of the cornea as a function of intraocular pressure, e) evaluating the changes in cardiac elastic anisotropy after myocardial infarction, f) development of an ultra-fast, single-shot, elastography technique, and g) development of a noncontact technique ca pable of assessing corneal geometry, eye-globe intraocular pressure, and corneal stiffness with a single instrument. Finally, the spatio-temporal properties of air-pulse induced displacement were characterized, and the repeatability and sensitivity of the OCE techniques described in this dissertation were compared to the “gold standard” of mechanical testing. The contributions of this work are crucial steps for the further development and clinical application of rapid, accurate, robust, and safe techniques capable of evaluating tissue biomechanical properties for early detection and monitoring of diseases.



Optical coherence tomography (OCT), Optical coherence elastography, Vision sciences, Biomechanical properties, Viscoelasticity