1. Articles from Xing Liang

    1-12 of 12
    1. In vivo three-dimensional optical coherence elastography

      In vivo three-dimensional optical coherence elastography
      Abstract: We present the first three-dimensional (3D) data sets recorded using optical coherence elastography (OCE). Uni-axial strain rate was measured on human skin in vivo using a spectral-domain optical coherence tomography (OCT) system providing >450 times higher line rate than previously reported for in vivo OCE imaging. Mechanical excitation was applied at a frequency of 125 Hz using a ring actuator sample arm with, for the first time in OCE measurements, a controlled static preload. We performed 3D-OCE, processed in 2D and displayed in 3D, on normal and hydrated skin and observed a more elastic response of the stratum corneum ...
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    2. Spectroscopic optical coherence elastography

      Spectroscopic optical coherence elastography
      We present an optical technique to image the frequency-dependent complex mechanical response of a viscoelastic sample. Three-dimensional hyperspectral data, comprising two-dimensional B-mode images and a third dimension corresponding to vibration frequency, were acquired from samples undergoing external mechanical excitation in the audio-frequency range. We describe the optical coherence tomography (OCT) signal when vibration is applied to a sample and detail the processing and acquisition techniques used to extract the local complex mechanical response from three-dimensional data that, due to a wide range of vibration frequencies, possess a wide range of sample velocities. We demonstrate frequency-dependent contrast of the displacement amplitude ...
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    3. Magnetomotive optical coherence tomography

      Magnetomotive optical coherence tomography
      A spectral-domain magnetomotive optical coherence tomography apparatus, includes (a) a spectral-domain optical coherence tomography device, and (b) a magnet. The magnet is coupled with the optical coherence tomography device so that changes in the magnetic field are coordinated with collection of data by the optical coherence tomography device. This device may be used to examine a sample by spectral-domain magnetomotive optical coherence tomography, which includes examining the sample with a spectral-domain optical coherence tomography device, to collect optical coherence tomography data. The sample contains magnetic particles, and the magnetic particles are subjected to a changing magnetic field during the examining.
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    4. Dynamic spectral-domain optical coherence elastography for tissue characterization

      Dynamic spectral-domain optical coherence elastography for tissue characterization
      A dynamic spectral-domain optical coherence elastography (OCE) imaging technique is reported. In this technique, audio-frequency compressive vibrations are generated by a piezoelectric stack as external excitation, and strain rates in the sample are calculated and mapped quantitatively using phase-sensitive spectral-domain optical coherence tomography. At different driving frequencies, this technique provides contrast between sample regions with different mechanical properties, and thus is used to mechanically characterize tissue. We present images of a three-layer silicone tissue phantom and rat tumor tissue ex vivo, based on quantitative strain rate. Both acquisition speed and processing speed are improved dramatically compared with previous OCE imaging ...
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    5. Feature Of The Week 2/21/10: Measurements of Biomechanics by Dynamic Optical Coherence Elastography

      Feature Of The Week 2/21/10: Measurements of Biomechanics by Dynamic Optical Coherence Elastography
      Feature Of The Week 2/21/10: Optical coherence elastograhy (OCE) is a novel elastography technique that can measure tissue biomechanical properties using mechanical excitations and in vivo optical coherence tomography (OCT). This technique has great potential for detecting mechanical property changes in the tissue micro-structure, such as tumor invasion, due to its high resolution, high speed and non-invasive features. OCE techniques can be classified as static and dynamic depending on its mechanical excitation approaches. Static methods are commonly used in conventional OCE studies, and are based on cross-correlation algorithms1. We concentrated on dynamic OCE techniques in which the sample ...
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    6. Magnetomotive nanoparticle transducers for optical rheology of viscoelastic materials

      Magnetomotive nanoparticle transducers for optical rheology of viscoelastic materials
      The availability of a real-time non-destructive modality to interrogate the mechanical properties of viscoelastic materials would facilitate many new investigations. We introduce a new optical method for measuring elastic properties of samples which employs magnetite nanoparticles as perturbative agents. Magnetic nanoparticles distributed in silicone-based samples are displaced upon probing with a small external magnetic field gradient and depth-resolved optical coherence phase shifts allow for the tracking of scatterers in the sample with nanometer-scale sensitivity. The scatterers undergo underdamped oscillations when the magnetic field is applied step-wise, allowing for the measurement of the natural frequencies of oscillation of the samples. Validation ...
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    7. Dynamic optical coherence elastography and applications

      Dynamic optical coherence elastography, an emerging optical technique to measure material mechanical properties using the non-invasive imaging modality of optical coherence tomography is introduced. Dynamic mechanical excitations were applied to the samples while a spectral domain optical coherence tomography system was used for detection. Based on a simple mechanical model, material mechanical properties such as Young's moduli can be extracted from detected phaseresolved signals. Biological tissues and their biomechanical properties are currently the main objects for this technique due to its micron-scale resolution and relatively deep penetration. Quantitative results were achieved by this technique on tissue phantoms and rat ...
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    8. Biomechanical Properties of in Vivo Human Skin From Dynamic Optical Coherence Elastography

      Biomechanical Properties of in Vivo Human Skin From Dynamic Optical Coherence Elastography
      Dynamic optical coherence elastography is used to determine in vivoskin biomechanical properties based on mechanical surface wave propagation. Quantitative Youngs moduli are measured on human skin from different sites, orientations, and frequencies. Skin thickness, including measurements from different layers, are also measured simultaneously. Experimental results show significant differences among measurements from different skin sites, between directions parallel and orthogonal to Langers lines, and under different skin hydration states. Results also suggest surface waves with different driving frequencies represent skin biomechanical properties from different layers in depth. With features such as micron-scale resolution, non-invasive imaging, and real-time processing from the optical ...
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    9. Acoustomotive optical coherence elastography for measuring material mechanical properties

      Acoustomotive optical coherence elastography for measuring material mechanical properties
      Acoustomotive optical coherence elastography (AM-OCE), a dynamic and internal excitation optical coherence elastography technique, is reported. Acoustic radiation force was used for internal mechanical excitation, and spectral-domain optical coherence tomography was used for detection. Mechanical properties of gelatin tissue phantoms were measured by AM-OCE and verified using rheometry results. Measured mechanical properties including shear moduli and shear damping parameters of the gelatin samples double when their polymer concentration increases from 3% to 4%. Spectral analysis was also performed on the acquired data, which improved the processing speed by a factor of 5 compared with a least-square fitting approach. Quantitative measurement ...
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    10. Imaging engineered tissues using structural and functional optical coherence tomography

      As the field of tissue engineering evolves, there will be an increasingly important need to visualize and track the complex dynamic changes that occur within three-dimensional constructs. Optical coherence tomography (OCT), as an emerging imaging technology applied to biological materials, offers a number of significant advantages to visualize these changes. Structural OCT has been used to investigate the longitudinal development of engineered tissues and cell dynamics such as migration, proliferation, detachment, and cell-material interactions. Optical techniques that image functional parameters or integrate multiple imaging modalities to provide complementary contrast mechanisms have been developed, such as the integration of optical coherence ...
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    11. Optical micro-scale mapping of dynamic biomechanical tissue properties

      Optical micro-scale mapping of dynamic biomechanical tissue properties
      Xing Liang, Amy L. Oldenburg, Vasilica Crecea, Eric J. Chaney, Stephen A. Boppart Mechanical forces such as adhesion, shear stress and compression play crucial roles in tissue growth, patterning and development. To understand the role of these mechanical stimuli, it is of great importance to measure biomechanical properties of developing, engineered, and natural tissues. To ... [Opt. Express 16, 11052-11065 (2008)]
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    12. Modeling and measurement of tissue elastic moduli using optical coherence elastography

      Xing Liang, Amy L. Oldenburg, Vasilica Crecea et al. Mechanical forces play crucial roles in tissue growth, patterning and development. To understand the role of mechanical stimuli, biomechanical properties are of great importance, as well as our ability to measure biomechanical properties of developing and engineered tissues. To enable these measurem ... [Proc. SPIE Int. Soc. Opt. Eng. 6858, 685803 (2008)] published Tue Feb 5, 2008.
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    1-12 of 12
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  2. Topics in the News

    1. (12 articles) Xing Liang
    2. (11 articles) University of Illinois at Urbana-Champaign
    3. (11 articles) Stephen A. Boppart
    4. (4 articles) Amy L. Oldenburg
    5. (3 articles) Vasilica Crecea
    6. (3 articles) Steven G. Adie
    7. (2 articles) University of Western Australia
    8. (2 articles) David D. Sampson
    9. (2 articles) Brendan F. Kennedy
    10. (2 articles) Kyungpook National University
    11. (2 articles) University of Washington
    12. (2 articles) Jeehyun Kim
    13. (2 articles) Ruchire Eranga Wijesinghe
    14. (2 articles) Mansik Jeon
    15. (1 articles) Eric J. Chaney
    16. (1 articles) University of Ulsan
    17. (1 articles) Tokyo Medical & Dental University
    18. (1 articles) University of Toronto
    19. (1 articles) Yasunori Sumi
    20. (1 articles) Ali M. Fard
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    Optical micro-scale mapping of dynamic biomechanical tissue properties Acoustomotive optical coherence elastography for measuring material mechanical properties Magnetomotive nanoparticle transducers for optical rheology of viscoelastic materials Feature Of The Week 2/21/10: Measurements of Biomechanics by Dynamic Optical Coherence Elastography Dynamic spectral-domain optical coherence elastography for tissue characterization Magnetomotive optical coherence tomography Spectroscopic optical coherence elastography In vivo three-dimensional optical coherence elastography A Generic Framework for Fourier-Domain Optical Coherence Tomography Imaging: Software Architecture and Hardware Implementations Vision-Inspection-Synchronized Dual Optical Coherence Tomography for High-Resolution Real-Time Multidimensional Defect Tracking in Optical Thin Film Industry Relative retinal flow velocity detection using optical coherence tomography angiography imaging Comparison of Optical Flow Ratio and Fractional Flow Ratio in Stent-Treated Arteries Immediately After Percutaneous Coronary Intervention