1. Articles from Zhongping Chen

    1-24 of 215 1 2 3 4 5 6 7 8 9 »
    1. High speed photo-mediated ultrasound therapy integrated with OCTA

      High speed photo-mediated ultrasound therapy integrated with OCTA

      Photo-mediated Ultrasound Therapy (PUT), as a new anti-vascular technique, can promote cavitation activity to selectively destruct blood vessels with a significantly lower amount of energy when compared to energy level required by other laser and ultrasound treatment therapies individually. Here, we report the development of a high speed PUT system based on a 50-kHz pulsed laser to achieve faster treatment, decreasing the treatment time by a factor of 20. Furthermore, we integrated it with optical coherence tomography angiography (OCTA) for real time monitoring. The feasibility of the proposed OCTA-guided PUT was validated through in vivo rabbit experiments. The addition of ...

      Read Full Article
    2. OCT Evaluation of Vaginal Epithelial Thickness during CO2 Laser Treatment: A Pilot Study

      OCT Evaluation of Vaginal Epithelial Thickness during CO2 Laser Treatment: A Pilot Study

      Genitourinary syndrome of menopause (GSM) negatively affects more than half of postmenopausal women. Energy-based therapy has been explored as a minimally invasive treatment for GSM; however, its mechanism of action and efficacy is controversial. Here, we report on a pilot imaging study conducted on a small group of menopause patients undergoing laser treatment. Intravaginal optical coherence tomography (OCT) endoscope was used to quantitatively monitor the changes in the vaginal epithelial thickness (VET) during fractional-pixel CO 2 laser treatment. 11 patients with natural menopause and 1 surgically induced menopause patient were recruited in this clinical study. Following the laser treatment, the ...

      Read Full Article
      Mentions: UC Irvine
    3. Visualization of ex vivo rabbit olfactory mucosa and foramina with three-dimensional optical coherence tomography

      Visualization of ex vivo rabbit olfactory mucosa and foramina with three-dimensional optical coherence tomography

      There is increasing interest in developing a minimally invasive imaging modality to safely evaluate dynamic microscopic changes of the olfactory mucosa and cribriform foramina. Herein, we utilized three-dimensional (3D) optical coherence tomography (OCT) to characterize the ex vivo stratified substructure of olfactory mucosa in rabbits and create 3D reconstructed images of olfactory foramina. Olfactory mucosa and cribriform plates from four New Zealand White rabbits were dissected and imaged using two swept-source OCT systems: (1) 1.3-µm (μm) center wavelength, 100-nm bandwidth, 200-kHz sweep rate, and (2) 1.7-μm center wavelength, 120-nm bandwidth, 90-kHz sweep rate. Volumetric OCT images ...

      Read Full Article
      Mentions: UC Irvine
    4. Intravascular polarization-sensitive optical coherence tomography based on polarization mode delay

      Intravascular polarization-sensitive optical coherence tomography based on polarization mode delay

      Intravascular polarization-sensitive optical coherence tomography (IV-PSOCT) provides depth-resolved tissue birefringence which can be used to evaluate the mechanical stability of a plaque. In our previous study, we reported a new strategy to construct polarization-sensitive optical coherence tomography in a microscope platform. Here, we demonstrated that this technology can be implemented in an endoscope platform, which has many clinical applications. A conventional intravascular OCT system can be modified for IV-PSOCT by introducing a 12-m polarization-maintaining fiber-based imaging probe. Its two polarization modes separately produce OCT images of polarization detection channels spatially distinguished by an image separation of 2.7 mm. We ...

      Read Full Article
      Mentions: UC Irvine
    5. Enhance the delivery of light energy ultra-deep into turbid medium by controlling multiple scattering photons to travel in open channels

      Enhance the delivery of light energy ultra-deep into turbid medium by controlling multiple scattering photons to travel in open channels

      Multiple light scattering is considered as the major limitation for deep imaging and focusing in turbid media. In this paper, we present an innovative method to overcome this limitation and enhance the delivery of light energy ultra-deep into turbid media with significant improvement in focusing. Our method is based on a wide-field reflection matrix optical coherence tomography (RM-OCT). The time-reversal decomposition of the RM is calibrated with the Tikhonov regularization parameter in order to get more accurate reversal results deep inside the scattering sample. We propose a concept named model energy matrix, which provides a direct mapping of light energy ...

      Read Full Article
      Mentions: UC Irvine
    6. Surface kinematic and depth-resolved analysis of human vocal folds in vivo during phonation using optical coherence tomography

      Surface kinematic and depth-resolved analysis of human vocal folds in vivo during phonation using optical coherence tomography

      Significance: The human vocal fold (VF) oscillates in multiple vectors and consists of distinct layers with varying viscoelastic properties that contribute to the mucosal wave. Office-based and operative laryngeal endoscopy are limited to diagnostic evaluation of the VF epithelial surface only and are restricted to axial-plane characterization of the horizontal mucosal wave. As such, understanding of the biomechanics of human VF motion remains limited. Aim: Optical coherence tomography (OCT) is a micrometer-resolution, high-speed endoscopic imaging modality which acquires cross-sectional images of tissue. Our study aimed to leverage OCT technology and develop quantitative methods for analyzing the anatomy and kinematics of ...

      Read Full Article
    7. 1.7-micron Optical Coherence Tomography Angiography for Characterization of Skin Lesions – A Feasibility Study

      1.7-micron Optical Coherence Tomography Angiography for Characterization of Skin Lesions – A Feasibility Study

      Optical coherence tomography (OCT) is a non-invasive diagnostic method that offers real-time visualization of the layered architecture of the skin in vivo. The 1.7-micron OCT system has been applied in cardiology, gynecology and dermatology, demonstrating an improved penetration depth in contrast to conventional 1.3-micron OCT. To further extend the capability, we developed a 1.7-micron OCT/OCT angiography (OCTA) system that allows for a visualization of both morphology and microvasculature in the deeper layers of the skin. Using this imaging system, we imaged human skin with different benign lesions and described the corresponding features of both structure and ...

      Read Full Article
      Mentions: UC Irvine
    8. Monitoring Response to Platelet-Rich Plasma in Patients with Alopecia Areata with Optical Coherence Tomography: A Case Series

      Monitoring Response to Platelet-Rich Plasma in Patients with Alopecia Areata with Optical Coherence Tomography: A Case Series

      Alopecia areata (AA) is an autoimmune hair loss condition that is difficult to treat and frequently disruptive to the psychosocial well-being of patients. Platelet-rich plasma (PRP) is an innovative therapy that provides concentrated GFs that impart anti-inflammatory effects. Optical coherence tomography (OCT) is a noninvasive imaging modality with the potential for providing quantitative monitoring of AA response to PRP. Our objective is to share our experience using OCT to monitor the therapeutic progress of patients with AA treated with PRP. Two patients with patchy AA and one with alopecia universalis were treated with PRP three times at 6-week intervals as ...

      Read Full Article
    9. Advances in Doppler optical coherence tomography and angiography

      Advances in Doppler optical coherence tomography and angiography

      Since the first demonstration of Doppler optical coherence tomography (OCT) in 1997, several functional extensions of Doppler OCT have been developed, including velocimetry, angiogram, and optical coherence elastography. These functional techniques have been widely used in research and clinical applications, particularly in ophthalmology. Here, we review the principles, representative methods, and applications of different Doppler OCT techniques, followed by discussion on the innovations, limitations, and future directions of each of these techniques

      Read Full Article
      Mentions: UC Irvine
    10. Coupling Pressure Sensing with Optical Coherence Tomography to Evaluate the Internal Nasal Valve

      Coupling Pressure Sensing with Optical Coherence Tomography to Evaluate the Internal Nasal Valve

      Purpose: To evaluate endoscopic long-range optical coherence tomography system combined with a pressure sensor to concurrently measure internal nasal valve cross-sectional area and intraluminal pressure. Methods: A pressure sensor was constructed using an Arduino platform and calibrated using a limiter-controlled vacuum system and industrial absolute pressure gauge. Long-range optical coherence tomography imaging and pressure transduction were performed concurrently in the naris of eight healthy adult subjects during normal respiration and forced inspiration. The internal nasal valve was manually segmented using Mimics software and cross-sectional area was measured. Internal nasal valve cross-sectional area measurements were correlated with pressure recordings. Results: Mean ...

      Read Full Article
      Mentions: UC Irvine
    11. Ultrahigh-sensitive optical coherence elastography

      Ultrahigh-sensitive optical coherence elastography

      The phase stability of an optical coherence elastography (OCE) system is the key determining factor for achieving a precise elasticity measurement, and it can be affected by the signal-to-noise ratio (SNR), timing jitters in the signal acquisition process, and fluctuations in the optical path difference (OPD) between the sample and reference arms. In this study, we developed an OCE system based on swept-source optical coherence tomography (SS-OCT) with a common-path configuration (SS-OCECP). Our system has a phase stability of 4.2 mrad without external stabilization or extensive post-processing, such as averaging. This phase stability allows us to detect a ...

      Read Full Article
      Mentions: UC Irvine
    12. Optical Vaginal Biopsy Using Optical Coherence Tomography

      Optical Vaginal Biopsy Using Optical Coherence Tomography

      Objective Optical coherence tomography is a noninvasive technology that visualizes tissue microstructure with high spatial resolution. We designed a novel vaginal system that demonstrates a clear distinction between vaginal tissues planes. In this study, we sought to compare vaginal tomographic images of premenopausal, perimenopausal, and postmenopausal women, demonstrate feasibility of tracking vaginal tissue changes after treatment with fractional-pixel CO 2 laser therapy, and obtain a histologic correlation of these findings. Methods Enrolled subjects underwent imaging and were divided into 3 groups based on menopausal status. Women with genitourinary syndrome of menopause who received fractional-pixel CO 2 laser therapy were assessed ...

      Read Full Article
      Mentions: UC Irvine
    13. Extended imaging depth of en-face optical coherence tomography based on fast measurement of a reflection matrix by wide-field heterodyne detection

      Extended imaging depth of en-face optical coherence tomography based on fast measurement of a reflection matrix by wide-field heterodyne detection

      Multiple light scattering in biomedical tissue limits the penetration depth of optical imaging systems such as optical coherence tomography. To increase the imaging depth in scattering media, a computational method based on coherent reflection matrix measurement has been developed using low coherence interferometry. The complex reflection matrix is obtained via point-by-point scanning followed by a phase-shifting method; then singular value decomposition is used to retrieve the singly back-scattered light. However, the in vivo application of the current reported method is limited due to the slow acquisition speed of the matrix. In this Letter, a wide-field heterodyne-detection method is adopted to ...

      Read Full Article
      Mentions: UC Irvine
    14. In vivo evaluation of posterior eye elasticity using shaker-based optical coherence elastography

      In vivo evaluation of posterior eye elasticity using shaker-based optical coherence elastography

      Age-related macular degeneration (AMD) is a progressive retinal disease and becomes the leading cause of blindness. It is well established that early detection is the key to preservation of functional vision. However, it is very difficult to diagnose AMD in very early stages, before structural changes are evident. Consequently, investigating the biomechanical properties of the retina maybe essential for understanding its physiological function. In this study, we present a shear wave-based quantitative method for estimating the elasticity of the posterior eye using shaker-based optical coherence elastography. This technique has been developed and validated on both a homogeneous phantom and a ...

      Read Full Article
    15. Spatiotemporal dynamics of pial collateral blood flow following permanent middle cerebral artery occlusion in a rat model of sensory-based protection: a Doppler optical coherence tomography study

      Spatiotemporal dynamics of pial collateral blood flow following permanent middle cerebral artery occlusion in a rat model of sensory-based protection: a Doppler optical coherence tomography study

      There is a growing recognition regarding the importance of pial collateral flow in the protection from impending ischemic stroke both in preclinical and clinical studies. Collateral flow is also a major player in sensory stimulation-based protection from impending ischemic stroke. Doppler optical coherence tomography has been employed to image spatiotemporal patterns of collateral flow within the dorsal branches of the middle cerebral artery (MCA) as it provides a powerful tool for quantitative in vivo flow parameters imaging (velocity, flux, direction of flow, and radius of imaged branches). It was employed prior to and following dorsal permanent MCA occlusion (pMCAo) in ...

      Read Full Article
      Mentions: UC Irvine
    16. The Use of Optical Coherence Tomography and Convolutional Neural Networks to Distinguish Normal and Abnormal Oral Mucosa

      The Use of Optical Coherence Tomography and Convolutional Neural Networks to Distinguish Normal and Abnormal Oral Mucosa

      Incomplete surgical resection of head and neck squamous cell carcinoma (HNSCC) is the most common cause of local HNSCC recurrence. Currently, surgeons rely on pre‐operative imaging, direct visualization, palpation, and frozen section to determine the extent of tissue resection. It has been demonstrated that optical coherence tomography (OCT), a minimally invasive, non‐ionizing near infrared mesoscopic imaging modality can resolve subsurface differences between normal and abnormal head and neck mucosa. Previous work has utilized 2‐D OCT imaging which is limited to the evaluation of a small regions of interest generated frame by frame. OCT technology is capable of ...

      Read Full Article
      Mentions: UC Irvine
    17. Method to characterize cut gemstones using optical coherence tomography

      Method to characterize cut gemstones using optical coherence tomography

      The invention includes an improvement in a method of assessing a gemstone having at least one planar face with an internally reflecting surface including the steps of optically modifying the at least one planar face of the gemstone to return a sample beam from an internally reflecting plane corresponding to the at least one planar face to an optical coherence tomography (OCT) system; selectively directing the sample beam from an optical coherence tomography (OCT) system onto the gemstone; and generating an OCT image map of the gemstone to determine volume, gem carat weight and/or quality.

      Read Full Article
      Mentions: UC Irvine
    18. Acoustic Radiation Force Optical Coherence Elastography

      Acoustic Radiation Force Optical Coherence Elastography

      Mechanical properties, such as the elasticity and viscosity, are often major indicators of diseases. Over the years, tissue mechanical properties have been demonstrated to be an early indicator for cardiovascular disease. Mechanical imaging technologies have been quickly evolving with a goal to effectively diagnose coronary artery disease and atherosclerosis in their early stages. By combining the advantages of acoustic and optical properties, acoustic radiation force optical coherence elastography (ARF-OCE) has become an imaging tool with a high potential for translation into clinics. In this chapter, we review the principles of OCE and describe the development of ARF-OCE systems for imaging ...

      Read Full Article
    19. Endoscopic Optical Coherence Tomography for Assessing Inhalation Airway Injury: A Technical Review

      Endoscopic Optical Coherence Tomography for Assessing Inhalation Airway Injury: A Technical Review

      Diagnosis of inhalation injury has been clinically challenging. Currently, assessment of inhalation injury relies on subjective clinical exams and bronchoscopy, which provides little understanding of tissue conditions and results in limited prognostics. Endoscopic Optical coherence tomography (OCT) technology has been recently utilized in the airway for direct assessment of respiratory tract disorders and injuries. Endoscopic OCT is capable of capturing highresolution images of tissue morphology 1-3 mm beneath the surface as well as the complex 3D anatomical shape. Previous studies indicate that changes in airway histopathology can be found in the OCT image almost immediately after inhalation of smoke and ...

      Read Full Article
      Mentions: UC Irvine
    20. Dynamic programming and automated segmentation of optical coherence tomography images of the neonatal subglottis: enabling efficient diagnostics to manage subglottic stenosis

      Dynamic programming and automated segmentation of optical coherence tomography images of the neonatal subglottis: enabling efficient diagnostics to manage subglottic stenosis

      Subglottic stenosis (SGS) is a challenging disease to diagnose in neonates. Long-range optical coherence tomography (OCT) is an optical imaging modality that has been described to image the subglottis in intubated neonates. A major challenge associated with OCT imaging is the lack of an automated method for image analysis and micrometry of large volumes of data that are acquired with each airway scan (1 to 2 Gb). We developed a tissue segmentation algorithm that identifies, measures, and conducts image analysis on tissue layers within the mucosa and submucosa and compared these automated tissue measurements with manual tracings. We noted small ...

      Read Full Article
      Mentions: UC Irvine
    21. Assessment of blood coagulation using an acoustic radiation force based optical coherence elastography (ARF-OCE)

      Assessment of blood coagulation using an acoustic radiation force based optical coherence elastography (ARF-OCE)

      An apparatus and method of using an optical coherence elastography (OCE) under acoustic radiation force (ARF) excitation includes the steps of inducing an excitation wave in a blood sample by use of an ultrasound beam from an ultrasonic transducer; measuring an elastic property of the blood sample by use of an optical coherence tomography (OCT) beam transverse to the ultrasound beam to dynamically measure the elastic property of the blood sample during coagulation and assessing the clot formation/dissolution kinetics and strength.

      Read Full Article
      Mentions: UC Irvine
    22. Fiber-based polarization-sensitive optical coherence tomography of a minimalistic system configuration

      Fiber-based polarization-sensitive optical coherence tomography of a minimalistic system configuration

      We present a very simple method of constructing a polarization-sensitive optical coherence tomography (PS-OCT) system. An ordinary fiber-based swept-source OCT system was reconfigured for PS-OCT by adding a long section of polarization-maintaining fiber in the sample arm. Two polarization modes of a large group-delay difference formed spatially distinguished polarization channels. The depth-encoded information on the polarization states was retrieved by an amplitude-based analysis. We found that our method provides an economic scheme of PS-OCT. It demonstrates that an ordinary OCT system can be easily reconfigured for PS-OCT imaging if it has sufficient margins in the imaging range.

      Read Full Article
      Mentions: UC Irvine
    23. Multimodal endoscopy for colorectal cancer detection by optical coherence tomography and near-infrared fluorescence imaging

      Multimodal endoscopy for colorectal cancer detection by optical coherence tomography and near-infrared fluorescence imaging

      While colonoscopy is the gold standard for diagnosis and classification of colorectal cancer (CRC), its sensitivity and specificity are operator-dependent and are especially poor for small and flat lesions. Contemporary imaging modalities, such as optical coherence tomography (OCT) and near-infrared (NIR) fluorescence, have been investigated to visualize microvasculature and morphological changes for detecting early stage CRC in the gastrointestinal (GI) tract. In our study, we developed a multimodal endoscopic system with simultaneous co-registered OCT and NIR fluorescence imaging. By introducing a contrast agent into the vascular network, NIR fluorescence is able to highlight the cancer-suspected area based on significant change ...

      Read Full Article
      Mentions: UC Irvine
    24. Automatic Proximal Airway Volume Segmentation Using Optical Coherence Tomography for Assessment of Inhalation Injury

      Automatic Proximal Airway Volume Segmentation Using Optical Coherence Tomography for Assessment of Inhalation Injury

      Background Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury with a mortality rate of up to 40%. Early management of ARDS has been difficult due to the lack of sensitive imaging tools and robust analysis software. We previously designed an optical coherence tomography (OCT) system to evaluate mucosa thickness (MT) post smoke inhalation, but the analysis relied on manual segmentation. The aim of this study is to assess in vivo proximal airway volume (PAV) after inhalation injury using automated OCT segmentation and correlate the PAV to lung function for rapid indication of ARDS. Methods Anesthetized ...

      Read Full Article
    1-24 of 215 1 2 3 4 5 6 7 8 9 »
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Topics in the News

    1. (205 articles) UC Irvine
    2. (22 articles) University of Southern California
    3. (4 articles) UCLA
    4. (4 articles) Pusan National University
    5. (3 articles) Ludwig-Maximilians University
    6. (3 articles) Gwangju Institute of Science and Technology
    7. (3 articles) OCT Medical Imaging Inc
    8. (2 articles) Fudan University
    9. (2 articles) National Institutes of Health
    10. (2 articles) Zhejiang University
    11. (1 articles) Mount Sinai School of Medicine
    12. (1 articles) Tokyo Medical & Dental University
  3. Popular Articles

  4. Picture Gallery

    High-speed and wide bandwidth Fourier domain mode-locked wavelength swept laser with multiple SOAs High-dynamic-range quantitative phase imaging with spectral domain phase microscopy Integrated intravascular optical coherence tomography (OCT) - ultrasound (US) imaging system Ultrawideband photonic crystal fiber coupler for multiband optical imaging system A dual-modality probe utilizing intravascular ultrasound and optical coherence tomography for intravascular imaging applications Feature Of The Week 11/24/13 : Miniature OCT/IVUS probe for automatically co-registered three-dimensional intracoronary imaging with real-time display Feature of The Week 05/19/2017: Longitudinal Shear Wave Imaging for Elasticity Mapping Using Optical Coherence Elastography Diagnostic accuracy of OCTA and OCT for myopic choroidal neovascularisation: a systematic review and meta-analysis Intraoperative Use of Wide-Field Optical Coherence Tomography to Evaluate Tissue Microstructure in the Oral Cavity and Oropharynx Assessment of optic disk by disk damage likelihood scale staging using slit-lamp biomicroscopy and optical coherence tomography in diagnosing primary open-angle glaucoma Central macular thickness and subfoveal choroidal thickness changes on spectral domain optical coherence tomography after cataract surgery in pediatric population Anterior segment optical coherence tomography characteristics and management of a unique spectrum of foreign bodies in the cornea and anterior chamber