Assessing mechanical properties of tissue phantoms with non-contact optical coherence elastography and Michelson interferometric vibrometry

Abstract

Abstract. Purpose: Elastography is an emerging method for detecting the pathological changes in tissue biomechanical properties caused by various diseases. In this study, we have compared two methods of noncontact optical elastography for quantifying Young's modulus of tissue-mimicking agar phantoms of various concentrations: a laser Michelson interferometric vibrometer and a phase-stabilized swept source optical coherence elastography system. Methods: The elasticity of the phantoms was estimated from the velocity of air-pulse induced elastic waves as measured by these two techniques. Results: The results show that both techniques were able to accurately assess the elasticity of the samples as compared to uniaxial mechanical compression testing. Conclusion: The laser Michelson interferometric vibrometer is significantly more cost-effective, but it cannot directly provide the elastic wave temporal profile, nor can it offer in-depth information.

Nanobomb optical coherence elastography

“…The elasticity of the 2% agar phantoms was measured as 84.3 ± 2.8 kPa by mechanical testing. These results are consistent with our previous work [23]. The shear viscosity of 1% agar samples was estimated as 0.03 ± 0.02 Pa·s by nanobomb excitation and 0.04 ± 0.01 Pa·s by air-pulse stimulation.…”