title: Assessing the mechanical properties of tissue-mimicking phantoms at different depths as an approach to measure biomechanical gradient of crystalline lens.
abstract: We demonstrate the feasibility of using the dominant frequency of the sample surface response to a mechanical stimulation as an effective indicator for sensing the depthwise distribution of elastic properties in transparent layered phantom samples simulating the cortex and nucleus of the crystalline lens. Focused ultrasound waves are used to noninvasively interrogate the sample surface. A phase-sensitive optical coherence tomography system is utilized to capture the surface dynamics over time with nanometer scale sensitivity. Spectral analysis is performed on the sample surface response to ultrasound stimulation and the dominant frequency is calculated under particular loading parameters. Pilot experiments were conducted on homogeneous and layered tissue-mimicking phantoms. Results indicate that the mechanical layers located at different depths introduce different frequencies to the sample surface response, which are correlated with the depth-dependent elasticity of the sample. The duration and the frequency of the ultrasound excitation are also investigated for their influences on this spectrum-based detection. This noninvasive method may be potentially applied for localized and rapid assessment of the depth dependence of the mechanical properties of the crystalline lens.
authors.affiliation: Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, Texas 77204, USA.
authors.forename: Shang
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Biomedical Engineering, The University of Texas at Austin, 107 W Dean Keeton Street, Austin, Texas 78712, USA.
authors.forename: Salavat
authors.initials: S
authors.lastname: Aglyamov
authors.affiliation: Department of Biomedical Engineering, The University of Texas at Austin, 107 W Dean Keeton Street, Austin, Texas 78712, USA.
authors.forename: Andrei
authors.initials: A
authors.lastname: Karpiouk
authors.affiliation: Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, Texas 77204, USA.
authors.forename: Jiasong
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, The University of Texas at Austin, 107 W Dean Keeton Street, Austin, Texas 78712, USA.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Emelianov
authors.affiliation: Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, Miami, Florida 33136, USA ; Biomedical Optics and Laser Laboratory, Department of Biomedical Engineering, University of Miami College of Engineering, 1251 Memorial Drive, Coral Gables, Florida 33146, USA.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Manns
authors.affiliation: Department of Biomedical Engineering, University of Houston, 3605 Cullen Boulevard, Houston, Texas 77204, USA ; Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77584, USA.
authors.forename: Kirill V
authors.initials: KV
authors.lastname: Larin
keywords: (110.4500) Optical coherence tomography; (120.5050) Phase measurement; (120.7280) Vibration analysis; (170.0170) Medical optics and biotechnology; (170.7170) Ultrasound