A5019754966- Optical Coherence Tomography Applications
- Photoacoustic and Ultrasonic Imaging
- Advanced Fluorescence Microscopy Techniques
- Optical Imaging and Spectroscopy Techniques
- Coronary Interventions and Diagnostics
- Retinal and Macular Surgery
- Cell Image Analysis Techniques
- Retinal Diseases and Treatments
- Photodynamic Therapy Research Studies
- Medical Imaging Techniques and Applications
- Energy Load and Power Forecasting
- Preterm Birth and Chorioamnionitis
- Nanoplatforms for cancer theranostics
- Advanced MEMS and NEMS Technologies
- Single-cell and spatial transcriptomics
- Esophageal Cancer Research and Treatment
- Electrowetting and Microfluidic Technologies
- Angiogenesis and VEGF in Cancer
- Laser-Matter Interactions and Applications
- Ultrasound Imaging and Elastography
- Photoreceptor and optogenetics research
- Endometrial and Cervical Cancer Treatments
- Digital Holography and Microscopy
- Optical measurement and interference techniques
- Cardiac Ischemia and Reperfusion
Johns Hopkins University
2014-2024
University of Science and Technology of China
2022-2024
Suzhou University of Science and Technology
2022-2024
Columbia University
2019-2022
Northwestern Polytechnical University
2022
Beijing University of Posts and Telecommunications
2022
University of International Business and Economics
2021
Brain (Germany)
2020
Optica
2019
Johns Hopkins Medicine
2012-2018
This manuscript reports on the first two-photon, label-free, metabolic imaging of biological tissues in vivo at histological resolution an extremely compact, fiber-optic endomicroscopy platform. system provides new opportunities for performing non-invasive and functional internal organs vivo, situ real time. As a routine clinical procedure, traditional histology has made significant impacts medicine. However, procedure is invasive time consuming, suffers random sampling errors, cannot...
Abstract Cancer is known to alter the local optical properties of tissues. The detection OCT-based attenuation provides a quantitative method efficiently differentiate cancer from non-cancer In particular, intraoperative use OCT able provide direct visual guidance in real time for accurate identification tissues, especially these without any obvious structural layers, such as brain cancer. However, current methods are suboptimal providing high-speed and mapping detection. this paper, we...
We investigated the optimal operational conditions for utilizing a broadband supercontinuum (SC) source in portable 800 nm spectral-domain (SD) endoscopic OCT system to enable high resolution, high-sensitivity, and high-speed imaging vivo. A SC with 3-dB bandwidth of ∼246 was employed obtain an axial resolution ∼2.7 μm (in air) detection sensitivity ∼-107 dB speed up 35 frames/s (at 70 k A-scans/s). The performance SC-based SD-OCT endoscopy demonstrated by guinea pig esophagus vivo,...
We present a novel design for an endoscopic imaging catheter utilizing diffractive optics ultrahigh-resolution optical coherence tomography (OCT) at 800 nm. A microlens was developed to alleviate severe chromatic aberration when broadband light source employed the nm wavelength range. Combined with home-built fiber rotary joint and Ti:sapphire laser, achieved lateral resolution of 6.2 μm axial 3.0 in air. The performance demonstrated by three-dimensional full-circumferential OCT guinea pig...
Lightweight and head-mountable scanning nonlinear fiberscope technologies offer an exciting opportunity for enabling mechanistic exploration of ensemble neural activities with subcellular resolution on freely behaving rodents. The tether the fiberscope, consisting optical fiber scanner drive wires, however, restricts mouse's movement consequently precludes free rotation limits freedom walking. Here we present first twist-free two-photon technology neuroimaging rotating/walking mice. equips a...
We compare the illumination uniformity and associated effects of spiral Lissajous scanning patterns that are commonly used in an endomicroscope. Theoretical analyses numerical simulations were first performed to quantitatively investigate area density pattern. The results revealed potential problem manifest photodamage due very high center scan. Similar pattern, which can be conveniently implemented on same endomicroscope with no hardware modifications, showed a more uniform about 80-fold...
Endoscopic optical coherence tomography (OCT) instruments are mostly side viewing and rely on at least one proximal scan, thus limiting accuracy of volumetric imaging en face visualization. Previous forward-viewing OCT devices had limited axial scan speeds. We report a fiber scanning 3D-OCT probe with 900 μm field view 5 transverse resolution, 1 MHz rate in the human gastrointestinal tract. The is 3.3 mm diameter 20 rigid length, enabling passage through endoscopic channel. scanner has 1.8...
Optical coherence tomography (OCT) has proven useful for detecting various oral maxillofacial abnormalities. To apply it to clinical applications including biopsy guidance and routine screening, a handheld imaging probe is indispensable. OCT probes reported were either based on bulky galvanometric mirror pair (not compact or long enough) distal-end microelectromechanical systems (MEMS) scanner (raised safety concerns), adapted from fiber-optic catheters (ill-suited cavity geometry).To...
We present the first, most compact, ultrahigh-resolution, high-speed, distal scanning optical coherence tomography (OCT) endoscope operating at 800 nm. Achieving high speed imaging while maintaining an ultrahigh axial resolution is one of significant challenges with endoscopic OCT Maintaining requires preservation broad spectral bandwidth light source throughout system. To overcome this critical limitation we implemented a diffractive optics to minimize loss in throughput. In paper, employed...
Endoscopic optical coherence tomography (OCT) is a noninvasive technology allowing for imaging of tissue microanatomies luminal organs in real time. Conventional endoscopic OCT operates at 1300 nm wavelength region with suboptimal axial resolution limited to 8‐20 μm. In this paper, we present the first ultrahigh‐resolution tethered capsule operating 800 and offering about 3‐ 4‐fold improvement (plus enhanced contrast). The uses diffractive optics manage chromatic aberration over full ~200...
In this work, we report a biopsy‐needle compatible rigid probe, capable of performing three‐dimensional (3D) two‐photon optical biopsy. The probe has small outer diameter 1.75 mm and fits inside gauge‐14 biopsy needle to reach internal organs. A carefully designed focus scanning mechanism been implemented in the which, along with rapid two‐dimensional MEMS scanner, enables 3D imaging. Fast image acquisition up 10 frames per second is possible, dramatically reducing motion artifacts during...
Compactness, among several others, is one unique and very attractive feature of a scanning fiber-optic two-photon endomicroscope. To increase the area total number resolvable pixels (i.e., imaging throughput), it typically requires longer cantilever which, however, leads to much undesired, reduced speed (and thus frame rate). Herein we introduce new design strategy for endomicroscope, where overall numerical aperture (NA) or beam focusing power distributed over two stages: 1) mode-field...
We report a generic method for automatic segmentation of endoscopic optical coherence tomography (OCT) images. In this method, OCT images are first processed with L1 -L0 norm minimization based de-noising and smoothing algorithms to increase the signal-to-noise ratio (SNR) enhance contrast between adjacent layers. The smoothed then formulated into cost graphs on their vertical gradients. After that, tissue-layer is performed shortest path search algorithm. efficacy capability demonstrated by...
Visualizing activity patterns of distinct cell types during complex behaviors is essential to understand neural networks. It remains challenging excite multiple fluorophores simultaneously so that different neurons can be imaged. In this Letter, we report a multicolor fiber-optic two-photon endomicroscopy platform in which two pulses from Ti:sapphire laser and an optical parametric oscillator were synchronized delivered through single customized double-clad fiber chromophores. A third...
NADH intensity and fluorescence lifetime characteristics have proved valuable intrinsic biomarkers for profiling the cellular metabolic status of living biological tissues. To fully leverage potential imaging microscopy (FLIM) in (pre)clinical studies translational applications, a compact flexible endomicroscopic embodiment is essential. Herein we present our newly developed two-photon (2PF) endomicroscope (2p-FLeM) that features an about 2 mm diameter, subcellular resolution, excellent...
Fiber-optic endomicroscopes open new avenues for the application of non-linear optics to novel in vivo applications. To achieve focus scanning vivo, shape memory alloy (SMA) wires have been used move optical elements miniature endomicroscopes. However, this method has various limitations, making it difficult accurate and reliable depth scanning. Here we present a feedback-controlled SMA scanner. With Hall effect sensor, contraction wire can be tracked real time, rendering robust control...
Depth-resolved optical attenuation coefficient is a valuable tissue parameter that complements the intensity-based structural information in coherent tomography (OCT) imaging. Herein we systematically analyzed under- and over-estimation bias of existing depth-resolved methods when applied to real biological tissues, then proposed new algorithm remedies these issues accommodates general OCT data contain incomplete decay noise floor, thereby affording consistent estimation accuracy for...
Objective: this study is to investigate the feasibility of our recently developed nonlinear fiberscope for label-free in situ breast tumor detection and lymph node status assessment based on second harmonic generation (SHG) imaging fibrillar collagen matrix with histological details. The long-term goal improve current biopsy-based cancer paradigm reduced sampling errors. Methods: pilot we undertook retrospective SHG ex vivo invasive ductal carcinoma human biopsy tissue samples, carried out...
The emerging fiber-optic two-photon endomicroscopy technology holds a strong promise for enabling translational applications of nonlinear optical imaging. Effective femtosecond pulse dispersion management is critical achieving high-quality Here we report systematic analyses and performance characterization dual-fiber spectro-temporal scheme involving grating pair as the stretcher. Compared with conventional linear-only compensation, grating-based compensation also takes into account effects...