1. Zhongping Chen

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    1. Mentioned In 238 Articles

    2. High resolution optical coherence tomography with an improved depth range using an axicon lens

      In optical coherence tomography (OCT), Axial and lateral resolutions are determined by the source coherence length and numerical aperture of the sampling lens, respectively. While axial resolution can be improved using a broadband light source, there is a trade-off between lateral resolution and focusing depth when conventional optical elements are used. The incorporation of an axicon lens into the sample arm of the interferometer overcomes this limitation. Using an axicon ...
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    3. Phase-resolved functional optical coherence tomography: simultaneous imaging of the stokes vectors, structure, blood flow velocity, standard deviation and birefringence in biological samples

      A phase-resolved functional optical coherence tomography system simultaneously obtains the Stokes vectors, structure, blood flow velocity, standard deviation, and birefringence images in human skin. The multifunctional images were obtained by processing the analytical interference fringe signals derived from the two perpendicular polarization detection channels. The blood flow velocity and standard deviation images were obtained by comparing the phase from the pairs of analytical signals in the neighboring A-lines in the ...
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    4. Imaging transverse flow velocity using spectral bandwidth of the doppler frequency shift in phase-resolved optical doppler tomography

      The Doppler bandwidth extracted from the standard deviation of the frequency shift in phase-resolved optical Doppler tomography (ODT) is used to image the velocity component transverse to the probing beam. The effective numerical aperture (NA) of the optical objective determines the slope of the dependence of the standard deviation on velocity. In the case where the angle between the probing beam and flow direction is within .+-.15 degrees to the ...
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    5. Advances in oral cancer detection using optical coherence tomography

      Advances in oral cancer detection using optical coherence tomography
      Optical coherence tomography (OCT) is a new modality capable of cross sectional imaging of biological tissue. Due to its many technical advantages such as high image resolution, fast acquisition time, and noninvasive capabilities, OCT is potentially useful in various medical applications. Because OCT systems can function with a fiber optic probe, they are applicable to almost any anatomic structures accessible either directly, or by endoscopy. OCT has the potential to ...
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    6. High-resolution second-harmonic optical coherence tomography of collagen in rat-tail tendon

      High-resolution second-harmonic optical coherence tomography of collagen in rat-tail tendon
      A high-resolution second-harmonic optical coherence tomography (SH-OCT) system is demonstrated using a spectrum broadened femtosecond Ti:sapphire laser. An axial resolution of 4.2 μm at the second-harmonic wave center wavelength of 400 nm has been achieved. Because the SH-OCT system uses the second-harmonic generation signals that strongly depend on the orientation, polarization, and local symmetry properties of chiral molecules, this technique provides unique contrast enhancement to conventional optical coherence ...
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    7. Ultrahigh-resolution optical coherence tomography with a fiber laser source at 1 µm

      Ultrahigh-resolution optical coherence tomography with a fiber laser source at 1 µm
      We report a compact, high-power, fiber-based source for ultrahigh-resolution optical coherence tomography (OCT) near 1 µm. The practical source is based on a short-pulse, ytterbium-doped fiber laser and on generation of a continuum spectrum in a photonic crystal fiber. The broadband emission has an average power of 140 mW and offers an axial resolution of 2.1 µm in air (1.6 µm in biological tissue). The generation of a ...
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    8. System for real time, non-invasive metrology of microfluidic chips

      A system integration of multicomponent technologies includes an automated microfluidic probe station and the use of that station for the systematic study of nonideal, nonhomogeneous biological fluids such as blood in microfluidic chips. The probe station provides for real-time, non-invasive metrology of microfluidic chips employing optical coherence tomography and optical Doppler tomography to allow for collection of flow data at any location or depth within a microfluidics chip. Also included ...
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    9. Phase-resolved optical coherence tomography and optical doppler tomography for imaging fluid flow in tissue with fast scanning speed and high velocity sensitivity

      The invention is a fast-scanning ODT system that uses phase information derived from a Hilbert transformation to increase the sensitivity of flow velocity measurements while maintaining high spatial resolution. The significant increases in scanning speed and velocity sensitivity realized by the invention make it possible to image in vivo blood flow in human skin. The method of the invention overcomes the inherent limitations of the prior art ODT by using ...
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    10. Method and apparatus for optical Doppler tomographic imaging of fluid flow velocity in highly scattering media

      Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived ...
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    11. 226-238 of 238 « 1 2 ... 13 14 15 16
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  2. About Zhongping Chen

    Zhongping Chen

    Zhongping Chen is a Professor of Biomedical Engineering and Director of the F-OCT Laboratory at the University of California, Irvine. He is a Co-founder and Chairman of OCT Medical Imaging Inc. Dr. Chen received his B.S. degree in Applied Physics from Shanghai Jiao Tong University in 1982, his M.S. degree in Electrical Engineering in 1987, and his Ph.D. degree in Applied Physics from Cornell University in 1993. Dr. Chen’s research interests encompass the areas of biomedical photonics, microfabrication, biomaterials and biosensors. His research group has pioneered the development of functional optical coherence tomography, which simultaneously provides high resolution 3-D images of tissue structure, blood flow, and birefringence. These functional extensions of OCT offer contrast enhancements and provide mapping of many clinically important parameters. In addition, his group has developed a number of endoscopic and intravascular rotational and linear 2-D probes for OCT and MPM imaging and translated these technologies to clinical applications through collaboration with clinicians. He has led numerous major research projects funded by NIH, NSF, DOD, and DARPA, including several interdisciplinary research projects such as the NIH Biomedical Research Partnership (BRP) grant and NSF Biophotonics Partnership Initiative grant. Dr. Chen has published more than 200 peer-reviewed papers and review articles and holds a number of patents in the fields of biomaterials, biosensors, and biomedical imaging. Dr. Chen is a Fellow of the American Institute of Medical and Biological Engineering (AIMBE), a Fellow of SPIE, and a Fellow of the Optical Society of America.