1. Articles from Shanshan Liang

    1-10 of 10
    1. Balanced detection spectral-domain optical coherence tomography with a single line-scan camera

      Balanced detection spectral-domain optical coherence tomography with a single line-scan camera

      This paper describes a balanced detection spectral-domain optical coherence tomography (BD-SD-OCT) system for suppressing autocorrelation (AC) artifacts and increasing the signal-to-noise ratio (SNR). The system employed three optical fiber couplers to generate two phase-opposed interference spectra that were acquired by a single line-scan camera simultaneously. When compared with conventional unbalanced detection SD-OCT systems, the developed BD-SD-OCT system improved the SNR by 5.4-6 dB and suppressed the AC term by 5-10 dB. The imaging quality of the BD-SD-OCT system was evaluated by in vivo imaging of human nail folds and retinas.

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    2. Dynamic-range compression and contrast enhancement in swept-source optical coherence tomography systems with a frequency gain compensation amplifier

      Dynamic-range compression and contrast enhancement in swept-source optical coherence tomography systems with a frequency gain compensation amplifier

      Significance: Optical coherence tomography (OCT) has been widely used in clinical studies. However, the image quality of OCT decreases with increasing imaging depth since the light is rapidly attenuated in biological tissues. Aim: We present a compensation approach to preserve weak high-frequency signals from deep structures and compress the dynamic range of the detected signal for superior analog-to-digital conversion and image display capability. Approach: A homemade frequency gain compensation amplifier is designed and fabricated to amplify the electrical signal from a balanced photodetector and compensate for the signal attenuation in swept-source OCT (SSOCT). Results: It is demonstrated in imaging various ...

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    3. Integrated Multifunctional Laryngoscope for Medical Diagnosis and Treatment

      Integrated Multifunctional Laryngoscope for Medical Diagnosis and Treatment

      Laryngeal lesions can cause great inconvenience to patients. Early diagnosis and corresponding treatments are critical to the survival of patients. However, the diagnosis and precise removal of tumors remain a challenge under the use of a white light laryngoscope. In this work, an integrated, multifunctional laryngoscope was designed and tested for the imaging evaluation and precision laser surgery for laryngeal tissue. This integrated diagnostic and therapeutic endoscopic system included two imaging modes (i.e., optical coherence tomography and white light endoscopy) and a laser ablation treatment mode. The endoscope had a common-path design to ensure that the same position could ...

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    4. Multi-modal Anterior Eye Imager Combining Ultra-High Resolution OCT and Microvascular Imaging for Structural and Functional Evaluation of the Human Eye

      Multi-modal Anterior Eye Imager Combining Ultra-High Resolution OCT and Microvascular Imaging for Structural and Functional Evaluation of the Human Eye

      To establish complementary information for the diagnosis and evaluation of ocular surface diseases, we developed a multi-modal, non-invasive optical imaging platform by combining ultra-high resolution optical coherence tomography (UHR-OCT) with a microvascular imaging system based on slit-lamp biomicroscopy. Our customized UHR-OCT module achieves an axial resolution of ≈2.9 μm in corneal tissue with a broadband light source and an A-line acquisition rate of 24 kHz with a line array CCD camera. The microvascular imaging module has a lateral resolution of 3.5 μm under maximum magnification of ≈187.5× with an imaging rate of 60 frames/s, which is ...

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    5. Correction of saturation effects in endoscopic swept-source optical coherence tomography based on dual-channel detection

      Correction of saturation effects in endoscopic swept-source optical coherence tomography based on dual-channel detection

      Saturation artifacts that are commonly observed in endoscopic swept-source optical coherence tomography (SSOCT) images cause image degradation and loss of image information. We present work on the correction of saturation effects in endoscopic SSOCT imaging. This method utilizes a broadband power divider with excellent pick-off flatness to divide the detected interference signal into the two channels of an analog-to-digital converter. Based on the precise calibration of the splitting ratio between the two channels, the maximum measurable signal power of the system was drastically increased by using the low level signal in one channel to correct the saturated signal in the ...

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    6. Contrast improvement for swept source optical coherence tomography image of sub-surface tissue

      Contrast improvement for swept source optical coherence tomography image of sub-surface tissue

      Swept source optical coherence tomography (SSOCT) is an attractive biological imaging technology due to its advantages of simple setup and high imaging speed. As the light intensity attenuated rapidly in high scattering biological tissues, the contrast of OCT image will drop with depth. In this paper a new method was introduced to compensate the attenuation of imaging contrast in SSOCT. The interference signal was divided into two channels of analog to digital converter (ADC) with a splitting ratio of 1:5. The higher level signal in one channel was used to reconstruct deeper structure of tissue and the lower level ...

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    7. Suppression of saturation artifacts in swept source optical coherence tomography using dual channel detection

      Suppression of saturation artifacts in swept source optical coherence tomography using dual channel detection

      A technique to suppress saturation artifacts in swept source optical coherence tomography (SSOCT) system was presented. The detected signal was split into two channels of a high speed data acquisition card with two levels by a power divider. The signal in one channel with higher level was used to reconstruct OCT images and the signal in the other channel with lower level was used to compensate the saturated signal in the first channel by calibrating the splitting ratio between the two channels. Based on dual channel detection, this technique can enhance the dynamic range of SSOCT system and remove saturation ...

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    8. Trimodality imaging system and intravascular endoscopic probe: combined optical coherence tomography, fluorescence imaging and ultrasound imaging

      Trimodality imaging system and intravascular endoscopic probe: combined optical coherence tomography, fluorescence imaging and ultrasound imaging

      In this Letter, we present a trimodality imaging system and an intravascular endoscopic probe for the detection of early-stage atherosclerotic plaques. The integrated system is able to acquire optical coherence tomography (OCT), fluorescence, and ultrasound images and simultaneously display them in real time. A trimodality intravascular endoscopic probe of 1.2 mm in diameter and 7 mm in length was fabricated based on a dual-modality optical probe that integrates OCT and fluorescence imaging functions and a miniature ultrasound transducer. The probe is capable of rotating at up to 600 rpm. Ex vivo images from rabbit aorta and human coronary arteries ...

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    9. Integrated IVUS-OCT for Real-Time Imaging of Coronary Atherosclerosis

      Integrated IVUS-OCT for Real-Time Imaging of Coronary Atherosclerosis

      Accurate assessment of atherosclerotic plaque characteristics and the subsequent tailoring of optimal therapy holds great promise for preventing acute coronary syndromes (ACS) and life-threatening sequelae 1 . Combined use of optical coherence tomography (OCT) and intravascular ultrasound (IVUS) was proposed as a potential method for accurate assessment of plaque characteristics and vulnerability ( 2 , ). However, significant challenges remain in trying to adapt an integrated OCT-IVUS system for clinical applications. We report here a fully integrated intracoronary OCT-IVUS imaging technique to visualize atherosclerotic plaque in living animals and human coronary arteries from cadavers with high resolution and deep penetration capability simultaneously.

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    10. Intravascular atherosclerotic imaging with combined fluorescence and optical coherence tomography probe based on a double-clad fiber combiner

      Intravascular atherosclerotic imaging with combined fluorescence and optical coherence tomography probe based on a double-clad fiber combiner

      We developed a multimodality fluorescence and optical coherence tomography probe based on a double-clad fiber (DCF) combiner. The probe is composed of a DCF combiner, grin lens, and micromotor in the distal end. An integrated swept-source optical coherence tomography and fluorescence intensity imaging system was developed based on the combined probe for the early diagnoses of atherosclerosis. This system is capable of real-time data acquisition and processing as well as image display. For fluorescence imaging, the inflammation of atherosclerosis and necrotic core formed with the annexin V–conjugated Cy5.5 were imaged. Ex vivo imaging of New Zealand white rabbit ...

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      Mentions: UC Irvine
    1-10 of 10
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  2. Topics in the News

    1. (7 articles) Sun Yat-Sen University
    2. (2 articles) University of Southern California
    3. (2 articles) UC Irvine
    4. (1 articles) University of Bologna
    5. (1 articles) University of Cambridge
    6. (1 articles) FDA
    7. (1 articles) Notal Vision
    8. (1 articles) Topcon Medical Systems
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    Intravascular atherosclerotic imaging with combined fluorescence and optical coherence tomography probe based on a double-clad fiber combiner Integrated IVUS-OCT for Real-Time Imaging of Coronary Atherosclerosis Trimodality imaging system and intravascular endoscopic probe: combined optical coherence tomography, fluorescence imaging and ultrasound imaging Suppression of saturation artifacts in swept source optical coherence tomography using dual channel detection Contrast improvement for swept source optical coherence tomography image of sub-surface tissue Correction of saturation effects in endoscopic swept-source optical coherence tomography based on dual-channel detection Multi-modal Anterior Eye Imager Combining Ultra-High Resolution OCT and Microvascular Imaging for Structural and Functional Evaluation of the Human Eye Integrated Multifunctional Laryngoscope for Medical Diagnosis and Treatment Dynamic-range compression and contrast enhancement in swept-source optical coherence tomography systems with a frequency gain compensation amplifier Balanced detection spectral-domain optical coherence tomography with a single line-scan camera Comparison of Anterior Segment Measurements with a New Multifunctional Unit and Five Other Devices Efficacy of Notal Vision Home OCT demonstrated by a series of scientific and clinical work