1. Articles from Guillermo J. Tearney

    1-24 of 186 1 2 3 4 5 6 7 8 »
    1. Flexible, high-resolution micro-optical coherence tomography endobronchial probe toward in vivo imaging of cilia

      Flexible, high-resolution micro-optical coherence tomography endobronchial probe toward in vivo imaging of cilia

      We report the design and fabrication of a flexible, longitudinally scanning high-resolution micro-optical coherence tomography (μOCT) endobronchial probe, optimized for micro-anatomical imaging in airways. The 2.4 mm diameter and flexibility of the probe allows it to be inserted into the instrument channel of a standard bronchoscope, enabling real-time video guidance of probe placement. To generate a depth-of-focus enhancing annular beam, we utilized a new fabrication method, whereby a hollow glass ferrule was angle-polished and gold-coated to produce an elongated annular reflector. We present validation data that verifies the preservation of linear scanning, despite the use of flexible materials. When ...

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    2. Passively scanned, single-fiber optical coherence tomography probes for gastrointestinal devices

      Passively scanned, single-fiber optical coherence tomography probes for gastrointestinal devices

      Background/objectives: Optical coherence tomography (OCT) uses low coherence interferometry to obtain depth-resolved tissue reflectivity profiles (M-mode) and transverse beam scanning to create images of two-dimensional tissue morphology (B-mode). Endoscopic OCT imaging probes typically employ proximal or distal mechanical beam scanning mechanisms that increase cost, complexity, and size. Here, we demonstrate in the gastrointestinal (GI) tracts of unsedated human patients, that a passive, single-fiber probe can be used to guide device placement, conduct device-tissue physical contact sensing, and obtain two-dimensional OCT images via M-to-B-mode conversion. Materials and methods: We designed and developed ultrasmall, manually scannable, side- and forward-viewing single fiber-optic ...

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    3. Optical coherence tomography in coronary atherosclerosis assessment and intervention

      Optical coherence tomography in coronary atherosclerosis assessment and intervention

      Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing ...

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    4. Extended depth of focus by self-imaging wavefront division with the mirror tunnel

      Extended depth of focus by self-imaging wavefront division with the mirror tunnel

      The mirror tunnel is a component used to extend the depth of focus for compact imaging probes used in endoscopic optical coherence tomography (OCT). A fast and accurate method for mirror tunnel probe simulation, characterization, and optimization is needed, with the aim of reconciling wave- and ray-optics simulation methods and providing a thorough description of the physical operating principle of the mirror tunnel. BeamLab software, employing the beam propagation method, was used to explore the parameter space and quantify lateral resolution and depth of focus extension. The lateral resolution performance was found to depend heavily on the metric chosen, implying ...

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    5. Histopathological correlation of near infrared autofluorescence in human cadaver coronary arteries

      Histopathological correlation of near infrared autofluorescence in human cadaver coronary arteries

      Background and aims Prior coronary optical coherence tomography (OCT)-near infrared fluorescence (NIRAF) imaging data has shown a correlation between high-risk morphological features and NIRAF signal intensity. This study aims to understand the histopathological origins of NIRAF in human cadaver coronary arteries. Methods Ex vivo intracoronary OCT-NIRAF imaging was performed on coronary arteries prosected from 23 fresh human cadaver hearts. Arteries with elevated NIRAF were formalin-fixed and paraffin-embedded. Microscopic images of immunostained Glycophorin A (indicating intraplaque hemorrhage) and Sudan Black (indicating ceroid after fixation) stained slides were compared with confocal NIRAF images (ex. 635 nm, em. 655–755 nm) from ...

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    6. Optical design, optimization and validation of an extended-depth-of-field optical coherence tomography probe based on mirror-tunneling

      Optical design, optimization and validation of an extended-depth-of-field optical coherence tomography probe based on mirror-tunneling

      We present results from optimizing mirror-tunnel based optical coherence tomography probes, achieving extended depth of field at high resolution. We achieved 6 µm spot diameter over 1 mm depth in simulations and validated experimentally.

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    7. Advances in Imaging of Subbasal Corneal Nerves With Micro–Optical Coherence Tomography

      Advances in Imaging of Subbasal Corneal Nerves With Micro–Optical Coherence Tomography

      Purpose: To investigate the most peripheral corneal nerve plexus using high-resolution micro-optical coherence tomography (µOCT) imaging and to assess µOCT's clinical potential as a screening tool for corneal and systemic diseases. Methods: An experimental high-resolution (1.5 × 1.5 × 1 µm) µOCT setup was applied for three-dimensional imaging of the subbasal nerve plexus in nonhuman primates (NHPs) and swine within 3 hours postmortem. Morphologic features of subbasal nerves in µOCT were compared to β3 tubulin-stained fluorescence confocal microscopy (FCM). Parameters such as nerve density, nerve distribution, and imaging repeatability were evaluated, using semiautomatic image analysis in form of a ...

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    8. Systems, methods, and media for multiple reference arm spectral domain optical coherence tomography

      Systems, methods, and media for multiple reference arm spectral domain optical coherence tomography

      In some embodiments, systems, methods, and media for multiple reference arm spectral domain optical coherence tomography are provided which, in some embodiments, includes: a sample arm coupled to a light source; a first reference arm having a first path length; a second reference arm having a longer second path length; a first optical coupler that combines light from the sample arm and the first reference arm; a second coupler that combines light from the sample arm and the second reference arm; and an optical switch comprising: a first input port coupled to the first optical coupler; a second input coupled ...

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    9. Endomicroscopy of the human cochlea using a micro-optical coherence tomography catheter

      Endomicroscopy of the human cochlea using a micro-optical coherence tomography catheter

      Sensorineural hearing loss (SNHL) is one of the most profound public health concerns of the modern era, affecting 466 million people today, and projected to affect 900 million by the year 2050. Advances in both diagnostics and therapeutics for SNHL have been impeded by the human cochlea's inaccessibility for in vivo imaging, resulting from its extremely small size, convoluted coiled configuration, fragility, and deep encasement in dense bone. Here, we develop and demonstrate the ability of a sub-millimeter-diameter, flexible endoscopic probe interfaced with a micro-optical coherence tomography (μOCT) imaging system to enable micron-scale imaging of the inner ear's ...

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    10. Clinical outcomes of low-intensity area without attenuation and cholesterol crystals in non-culprit lesions assessed by optical coherence tomography

      Clinical outcomes of low-intensity area without attenuation and cholesterol crystals in non-culprit lesions assessed by optical coherence tomography

      Background and aims Pathologists have shown that intraplaque hemorrhage contributes to plaque destabilization and is frequently co-located with cholesterol crystals (CC). Optical coherence tomography (OCT)-detected low-intensity area without attenuation (LIA) may represent intraplaque hemorrhage. We aimed to examine the prevalence and impact of OCT-detected LIA + CC in untreated non-culprit lesions (NCLs) on subsequent major adverse cardiac events (MACE). Methods OCT imaged NCLs in the culprit vessel in the patients who underwent OCT-guided percutaneous coronary intervention were included. An NCL was a lesion with >90° of diseased arc (≥0.5 mm intimal thickness), length ≥2 mm, and >5 mm away ...

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    11. Dual-modality optical coherence tomography and fluorescence tethered capsule endomicroscopy

      Dual-modality optical coherence tomography and fluorescence tethered capsule endomicroscopy

      OCT tethered capsule endomicroscopy (TCE) is an emerging noninvasive diagnostic imaging technology for gastrointestinal (GI) tract disorders. OCT measures tissue reflectivity that provides morphologic image contrast, and thus is incapable of ascertaining molecular information that can be useful for improving diagnostic accuracy. Here, we introduce an extension to OCT TCE that includes a fluorescence (FL) imaging channel for attaining complementary, co-registered molecular contrast. We present the development of an OCT-FL TCE capsule and a portable, plug-and-play OCT-FL imaging system. The technology is validated in phantom experiments and feasibility is demonstrated in a methylene blue (MB)-stained swine esophageal injury model ...

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    12. Multi-channel optical fiber rotary junction

      Multi-channel optical fiber rotary junction

      Exemplary apparatus, systems, methods of making, and methods of using a rotary junction are provided. A rotary junction having multiple channels is provided herein. The rotary junction has a first coupling optic and a second coupling optic where the rotating optical fiber or other waveguide comping from the first coupling optic passes through the second coupling optics. 5271076 December 1993 5287423 February 1994 Anthony 5337734 August 1994 5347990 September 1994 Ebling et al.

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    13. Modeling, optimization, and validation of an extended-depth-of-field optical coherence tomography probe based on a mirror tunnel

      Modeling, optimization, and validation of an extended-depth-of-field optical coherence tomography probe based on a mirror tunnel

      The diagnostic capability of high-resolution optical coherence tomography (OCT) may be enhanced by using extended depth-of-field (EDOF) imaging that retains high transverse resolution over long depths. A recently developed mirror-tunnel optical probe design (single-mode fiber to multimode fiber to lens structure) that generates coaxially focused modes has been previously shown to enable EDOF for endoscopic OCT applications. Here, we present ray-tracing optical modeling of this optical configuration, which has the potential to guide performance improvement through optimization. The Huygens wave propagation of the field was traced through probe components with initial lengths. The irradiance along the

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    14. Improved sensitivity roll-off in dual reference, buffered spectral-domain optical coherence tomography

      Improved sensitivity roll-off in dual reference, buffered spectral-domain optical coherence tomography

      Significance: While spectral-domain optical coherence tomography (SD-OCT) is a preferred form of OCT imaging, sensitivity roll-off limits its applicability for certain biomedical imaging applications. Aim: The aim of this work is to extend the imaging range of conventional SD-OCT systems for imaging large luminal organs such as the gastrointestinal tract. Approach: We present an SD-OCT system operating at a center wavelength of 1300 nm that uses two delayed reference arms to reduce sensitivity roll-off and an optical switch and a fiber optic delay line to ensure that the interference spectra are acquired from the same sample time window. Result: The ...

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    15. Apparatus, devices and methods for in vivo imaging and diagnosis

      Apparatus, devices and methods for in vivo imaging and diagnosis

      Exemplary method and apparatus for diagnosing or characterizing an inflammation within an anatomical structure can be provided. For example, using at least one source arrangement, it is possible to provide at least one first electro-magnetic radiation to the anatomical structure at least one first wavelength in vivo. With at least one detector arrangement, it is possible to detect at least one second electro-magnetic radiation at least one second wavelength provided from the anatomical structure. The second radiation can be associated with the first radiation, and the first wavelength can be shorter than the second wavelength. The second radiation can be ...

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    16. Micro-optical coherence tomography for high-resolution morphologic imaging of cellular and nerval corneal micro-structures

      Micro-optical coherence tomography for high-resolution morphologic imaging of cellular and nerval corneal micro-structures

      We demonstrate the highest resolution (1.5×1.5×1 µm) micrometer optical coherence tomography (µOCT) imaging of the morphologic micro-structure of excised swine and non-human primate corneas. Besides epithelial, stromal, and endothelial cell morphology, this report focuses on investigating the most peripheral corneal nerve fibers, the nerve fibers of the subbasal plexus (SBP). Alterations of SBP nerve density and composition are reportedly linked to major neurologic disorders, such as diabetic neuropathy, potentially indicating earliest onsets of denervation. Here, the fine, hyperreflective, epithelial nerve structures located just above Bowman’s membrane, are i) visualized using our µOCT prototype, ii) validated ...

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    17. OCT and CMR for the Diagnosis of Patients Presenting With MINOCA and Suspected Epicardial Causes

      OCT and CMR for the Diagnosis of Patients Presenting With MINOCA and Suspected Epicardial Causes

      Background OCT is able to identify different morphologic features of coronary plaques that are well known causes of MINOCA. Furthermore, CMR has become the gold standard for detection of myocardial infarction in the setting of MINOCA. Methods In a prospective 2-center study, consecutive patients with MINOCA including ECG features of ischemia associated with corresponding WMAs underwent OCT and CMR. Results Forty patients (mean age: 50 ± 11 years, 62.5% male, 32.5% with ST-segment elevation) were enrolled. Coronary arteries were normal on coronary angiography in 10 patients (25%); 18 patients (45%) presented minimal lumen irregularities, whereas the remaining 12 patients ...

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    18. System and method for facilitating manual and/or automatic volumetric imaging with real-time tension or force feedback using a tethered imaging device

      System and method for facilitating manual and/or automatic volumetric imaging with real-time tension or force feedback using a tethered imaging device

      According to exemplary embodiments of the present disclosure, apparatus, device and method can be provided which can provide imaging of biological tissues, e.g., luminal organs in vivo, using optical techniques in an automatic or semiautomatic manner. The exemplary apparatus, device and method can utilize a tethered capsule catheter with a mechanism for manual, semi-automatic or automatic traversing in the luminal organ with a controlled velocity and/or image quality. The exemplary apparatus can include feedback information about tension applied to the catheter during its movement that can be used to adjust velocity and assure patient comfort and safety for ...

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    19. Imaging intracellular motion with dynamic micro-optical coherence tomography

      Imaging intracellular motion with dynamic micro-optical coherence tomography

      This paper describes a new technology that uses 1-µm-resolution optical coherence tomography (µOCT) to obtain cross-sectional images of intracellular dynamics with dramatically enhanced image contrast. This so-called dynamic µOCT (d-µOCT) is accomplished by acquiring a time series of µOCT images and conducting power frequency analysis of the temporal fluctuations that arise from intracellular motion on a pixel-per-pixel basis. Here, we demonstrate d-µOCT imaging of freshly excised human esophageal and cervical biopsy samples. Depth-resolved d-µOCT images of intact tissue show that intracellular dynamics provides a new contrast mechanism for µOCT that highlights subcellular morphology and activity in ...

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    20. Stromal Nerve Imaging and Tracking Using Micro-Optical Coherence Tomography

      Stromal Nerve Imaging and Tracking Using Micro-Optical Coherence Tomography

      urpose : To image, track and map the nerve fiber distribution in excised rabbit corneas over the entire stromal thickness using micro-optical coherence tomography (µOCT) to develop a screening tool for early peripheral neuropathy. Methods : Excised rabbit corneas were consecutively imaged by a custom-designed µOCT prototype and a commercial laser scanning fluorescence confocal microscope. The µOCT images with a field of view of approximately 1 × 1 mm were recorded with axial and transverse resolutions of approximately 1 µm and approximately 4 µm, respectively. In the volumetric µOCT image data, network maps of hyper-reflective, branched structures traversing different stromal compartments were segmented ...

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    21. Devices, systems, methods and storage mediums using full range optical coherence tomography

      Devices, systems, methods and storage mediums using full range optical coherence tomography

      One or more devices, systems, methods and storage mediums for performing continuously, full range optical coherence tomography (OCT) without losing A-lines are provided. Examples of such applications include imaging, evaluating and diagnosing biological objects, such as, but not limited to, for cardio and/or ophthalmic applications, and being obtained via one or more optical instruments, such as, but not limited to, optical probes (e.g., common path probes), catheters, endoscopes, phase shift units (e.g., galvanometer scanner) and bench top systems. Preferably, the OCT devices, systems methods and storage mediums include or involve a phase shift device including at least ...

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    22. All fiber polarization insensitive detection for spectrometer based optical coherence tomography using optical switch

      All fiber polarization insensitive detection for spectrometer based optical coherence tomography using optical switch

      Polarization dependent image artifacts are common in optical coherence tomography imaging. Polarization insensitive detection scheme for swept source based optical coherence tomography systems is well established but is yet to be demonstrated for all fiber spectrometer-based Fourier domain optical coherence tomography systems. In this work, we present an all fiber polarization insensitive detection scheme for spectrometer based optical coherence tomography systems. Images from chicken breast muscle tissue were acquired to demonstrate the effectiveness of this scheme for the conventional Fourier domain optical coherence tomography system.

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    23. 3D cellular-resolution imaging in arteries using few-mode interferometry

      3D cellular-resolution imaging in arteries using few-mode interferometry

      Article Open Access Published: 21 November 2019 3D cellular-resolution imaging in arteries using few-mode interferometry Biwei Yin , Zhonglie Piao , Kensuke Nishimiya , Chulho Hyun , Joseph A. Gardecki , Adam Mauskapf , Farouc A. Jaffer & Guillermo J. Tearney Light: Science & Applications volume 8 , Article number: 104 ( 2019 ) Cite this article Article metrics 3 Altmetric Metrics details Abstract Cross-sectional visualisation of the cellular and subcellular structures of human atherosclerosis in vivo is significant, as this disease is fundamentally caused by abnormal processes that occur at this scale in a depth-dependent manner. However, due to the inherent resolution-depth of focus tradeoff of conventional focusing optics, today ...

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    24. Excess mucus viscosity and airway dehydration impact COPD airway clearance

      Excess mucus viscosity and airway dehydration impact COPD airway clearance

      The mechanisms by which cigarette smoking impairs airway mucus clearance are not well understood. We recently established a ferret model of cigarette smoke-induced chronic obstructive pulmonary disease (COPD) exhibiting chronic bronchitis. We investigated the effects of cigarette smoke on mucociliary transport (MCT). Adult ferrets were exposed to cigarette smoke for 6 months, with in vivo mucociliary clearance (MCC) measured by Tc-labeled DTPA (Tc-DTPA) retention. Excised tracheae were imaged with micro-optical coherence tomography. Mucus changes in primary human airway epithelial cells and ex vivo ferret airways were assessed by histology and particle tracking microrheology. Linear mixed models for repeated measures identified ...

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    1-24 of 186 1 2 3 4 5 6 7 8 »
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    Handbook of Optical Coherence Tomography (Book) Heart wall velocimetry and exogenous contrast-based cardiac flow imaging in Drosophila melanogaster using Doppler optical coherence tomography Automated segmentation and characterization of esophageal wall in vivo by tethered capsule optical coherence tomography endomicroscopy Feature of the Week 04/24/2016: μOCT Imaging Using Depth of Focus Extension by Self-Imaging Wavefront Division in a Common-Path Fiber Optic Probe Postdoctoral Research Fellowships in Optical Coherence Tomography at Massachusetts General Hosptial Interplay between traveling wave propagation and amplification at the apex of the mouse cochlea Postdoctoral Position in Advanced Ophthalmic imaging at Johns Hopkins Revealing how maltodextrin-containing droplets dry using optical coherence tomography Repeatability and Agreement of Two Swept-Source Optical Coherence Tomographers for Anterior Segment Parameter Measurements Machine Learning Utility for Optical Coherence Tomography in Multiple Sclerosis: Is the Future Now? The Role of OCT Criteria and Machine Learning in Multiple Sclerosis and Optic Neuritis Diagnosis Ray Tracing versus Thin-Lens Formulas for IOL Power Calculation Using Swept-Source Optical Coherence Tomography Biometry