Abstract:We report on a quantitative optical elastographic method based on shear wave imaging optical coherence tomography (SWI-OCT) for biomechanical characterization of cardiac muscle through noncontact elasticity measurement. The SWI-OCT system employs a focused air-puff device for localized loading of the cardiac muscle and utilizes phasesensitive OCT to monitor the induced tissue deformation. Phase information from the optical interferometry is used to reconstruct 2-D depth-resolved shear wave propagation inside the muscle tissue. Cross-correlation of the displacement profiles at various spatial locations in the propagation direction is applied to measure the group velocity of the shear waves, based on which the Young's modulus of tissue is quantified. The quantitative feature and measurement accuracy of this method is demonstrated from the experiments on tissue-mimicking phantoms with the verification using uniaxial compression test. The experiments are performed on ex vivo cardiac muscle tissue from mice with normal and genetically altered myocardium. Our results indicate this optical elastographic technique is useful as a noncontact tool to assist the cardiac muscle studies. shear wave propagation using phase-sensitive optical coherence tomography for dynamic elastography," Opt. Lett. 39(4), 838-841 (2014). 33. C. Li, G. Guan, Z. Huang, M. Johnstone, and R. K. Wang, "Noncontact all-optical measurement of corneal elasticity," Opt. Lett. 37(10), 1625-1627 (2012). 34. C. Li, G. Guan, R. Reif, Z. Huang, and R. K. Wang, "Determining elastic properties of skin by measuring surface waves from an impulse mechanical stimulus using phase-sensitive optical coherence tomography," J. R. Soc. Interface 9(70), 831-841 (2012). 35. X. Liang and S. A. Boppart, "Biomechanical properties of In vivo human skin from dynamic optical coherence elastography," IEEE Trans. Biomed. Eng. 57(4), 953-959 (2010). 36.