We demonstrate the use of a modified Rayleigh–Lamb frequency equation in conjunction with noncontact optical coherence elastography to quantify the viscoelastic properties of the cornea. Phase velocities of air-pulse-induced elastic waves were extracted by spectral analysis and used for calculating the Young’s moduli of the samples using the Rayleigh–Lamb frequency equation (RLFE). Validation experiments were performed on 2% agar phantoms ( n = 3 ) and then applied to porcine corneas ( n = 3 ) in situ . The Young’s moduli of the porcine corneas were estimated to be ∼ 60 kPa with a shear viscosity ∼ 0.33 Pa ⋅ s . The results demonstrate ...
Purpose: To evaluate the capability of a novel co-aligned focused ultrasound and phase-sensitive optical coherence elastography (US-OCE) system to assess age-related changes in biomechanical properties of the crystalline lens in situ. Methods: Low-amplitude elastic deformations in young and mature rabbit lenses were measured by the US-OCE system consisting of a spectral-domain optical coherence tomography (OCT) system co-aligned with focused ultrasound used to produce a transient force on the lens surface. Uniaxial compressional tests were used to confirm the OCE data. Results: The OCE measurements showed that the maximum displacements of the young rabbit lenses were significantly larger than those of ...
The ability to conduct highly localized delivery of contrast agents, viral vectors, therapeutic or pharmacological agents, and signaling molecules or dyes to live mammalian embryos is greatly desired to enable a variety of studies in the field of developmental biology, such as investigating the molecular regulation of cardiovascular morphogenesis. To meet such a demand, we introduce, for the first time, the concept of employing optical coherence tomography (OCT)-guide microinjections in live mouse embryos, which provides precisely targeted manipulation with spatial resolution at the micrometer scale. The feasibility demonstration is performed with experimental studies on cultured live mouse embryos at ...
The cardiovascular system is the first functional organ system to develop within the mammalian embryo. During the early stages of cardiovascular development, the heart and blood vessels undergo rapid growth and remodeling required for embryo viability, proper morphogenesis, and the function of all organ systems. Live imaging of these dynamic events in early mouse embryos is critical to understanding when and how these morphological changes occur during normal development and how mutations and pharmacological agents affect cardiovascular structure and function in vivo. The use of optical coherence tomography (OCT) allows for rapid, three-dimensional structural and functional imaging of mouse embryos ...
The development of an effective system to monitor the changes in the elastic properties of cartilage tissue with increasing temperature in laser reconstruction is an urgent practical task. In this paper, the use of phase-sensitive optical coherence elastography for detection of elastic waves in the sample has allowed Young's modulus of cartilage tissue to be measured directly during heating. Young's modulus was calculated from the group velocity of propagation of elastic waves excited by means of a system supplying focused air pulses. The measurement results are in agreement with the results of measurements of the modulus of elasticity ...
Current technique for tumor resection requires biopsy of the tumor region and histological confirmation before the surgeon can be certain that the entire tumor has been resected. This confirmation process is time consuming both for the surgeon and the patient and also requires sacrifice of healthy tissue, motivating the development of novel technologies which can enable real-time detection of tumor-healthy tissue boundary for faster and more efficient surgeries. In this study, the potential of combining structural information from optical coherence tomography (OCT) and molecular information from line-scan Raman microscopy (LSRM) for such an application is presented. The results show a ...
Kirill V. Larin is Assistant Professor of Biomedical Engineering at the University of Houston, Houston, TX. His research interests focuses on development and application of OCT for noninvasive and nondestructive imaging and diagnostics of tissues and cells. Larin has authored more than 40 peer-reviewed journal publications and chapters in two textbooks on Biomedical Optics. He is recipient of Boris Yeltsin Presidential Award, Wallace Coulter Young Investigator Translation Award, Office of Naval Research Young Investigator Award, and Outstanding Young Investigator Award from the Houston Society for Engineers in Medicine and Biology.
We are using OCT to image mouse and rat embryos, looking at video taken about seven days after conception, out of a 20-day typical mammalian pregnancy...this way, we are able to capture video of the embryonic heart before it begins beating, and a day later we can see the heart beginning to form in the shape of a tube and see whether or not the chambers are contracting. Then, we begin to see blood distribution and the heart rate.In The Embryonic Heart: Imaging Life as it Happens - University of Houston Professor Captures Video of Heart Before it Begins to Beat (Video Snippet)
Our primary objective is to develop noninvasive, early detection methods to diagnose various diseases.In U. Houston professor expands Optics research