A5083806662- Optical Coherence Tomography Applications
- Photoacoustic and Ultrasonic Imaging
- Semiconductor Lasers and Optical Devices
- Advanced Photonic Communication Systems
- Advanced Fluorescence Microscopy Techniques
- Photonic and Optical Devices
- Ultrasound Imaging and Elastography
- Optical Network Technologies
- Protein Degradation and Inhibitors
- Prostate Cancer Treatment and Research
- Optical Imaging and Spectroscopy Techniques
- Glaucoma and retinal disorders
- Retinal and Macular Surgery
- graph theory and CDMA systems
- Cellular Mechanics and Interactions
- Advanced Fiber Optic Sensors
- Coronary Interventions and Diagnostics
- Digital Holography and Microscopy
- Advanced Breast Cancer Therapies
- Obstructive Sleep Apnea Research
- Advanced Fiber Laser Technologies
- Corneal surgery and disorders
- Cell Image Analysis Techniques
- Retinal Diseases and Treatments
- Peptidase Inhibition and Analysis
University of Surrey
2018-2024
University of South Florida
2024
The University of Western Australia
2012-2022
Wuhan University
2022
Leibniz Institute of Photonic Technology
2022
Friedrich Schiller University Jena
2022
John Wiley & Sons (Germany)
2022
Technical University of Denmark
2022
Munster Technological University
2022
National Yang Ming Chiao Tung University
2022
The spatial presentation of mechanical information is a key parameter for cell behavior. We have developed method polymerization control in which the differential diffusion distance unreacted cross-linker and monomer into prepolymerized hydrogel sink results tunable stiffness gradient at cell-matrix interface. This simple, low-cost, robust was used to produce polyacrylamide hydrogels with gradients 0.5, 1.7, 2.9, 4.5, 6.8, 8.2 kPa/mm, spanning vivo physiological pathological landscape....
To evaluate the impact of image magnification correction on superficial retinal vessel density (SRVD) and foveal avascular zone area (FAZA) measurements using optical coherence tomography angiography (OCTA).Participants with healthy retinas were recruited for ocular biometry, refraction, RTVue XR Avanti OCTA imaging 3 × 3-mm protocol. The parafoveal SRVD FAZA quantified custom software before after error Littman modified Bennett formulae. Relative changes between corrected uncorrected...
Probing the mechanical properties of tissue on microscale could aid in identification diseased tissues that are inadequately detected using palpation or current clinical imaging modalities, with potential to guide medical procedures such as excision breast tumours. Compression optical coherence elastography (OCE) maps strain spatial resolution and can delineate microstructural features within tissues. However, without a measure locally applied stress, provides only qualitative indication...
We report a new synthetic aperture optical microscopy in which high-resolution, wide-field amplitude and phase images are synthesized from set of Fourier holograms. Each hologram records region the complex two-dimensional spatial frequency spectrum an object, determined by illumination field's spectral properties collection angle solid angle. demonstrate microscopic imaging frequencies that well outside modulation transfer function system recorded while maintaining long working distance wide...
We review the development of phantoms for optical coherence tomography (OCT) designed to replicate optical, mechanical and structural properties a range tissues. Such are key requirement continued OCT techniques applications. focus on based silicone, fibrin poly(vinyl alcohol) cryogels (PVA-C), as we believe these materials hold most promise durable accurate replication tissue properties.
We present a theoretical framework for strain estimation in optical coherence elastography (OCE), based on statistical analysis of displacement measurements obtained from mechanically loaded sample. define sensitivity, signal-to-noise ratio and dynamic range, derive estimates using three methods: finite difference, ordinary least squares weighted squares, the latter implemented first time OCE. compare predictions with experimental results demonstrate ~12 dB improvement sensitivity compared...
We present the first three-dimensional (3D) data sets recorded using optical coherence elastography (OCE). Uni-axial strain rate was measured on human skin in vivo a spectral-domain tomography (OCT) system providing >450 times higher line than previously reported for OCE imaging. Mechanical excitation applied at frequency of 125 Hz ring actuator sample arm with, time measurements, controlled static preload. performed 3D-OCE, processed 2D and displayed 3D, normal hydrated observed more...
We utilize synthetic-aperture Fourier holographic microscopy to resolve micrometer-scale microstructure over millimeter-scale fields of view. Multiple holograms are recorded, each registering a different, limited region the sample object's spectrum. They "stitched together" generate synthetic aperture. A low-numerical-aperture (NA) objective lens provides wide field view, and additional advantages long working distance, no immersion fluids, an inexpensive, simple optical system. Following...
We present a novel sample arm arrangement for dynamic optical coherence elastography based on excitation by ring actuator. The actuator enables coincident and imaging to be performed sample, facilitating in vivo operation. Sub-micrometer vibrations the audio frequency range were coupled samples that imaged using tomography. resulting vibration amplitude microstrain maps are presented bilayer silicone phantoms multiple skin sites human subject. Contrast differing elastic properties is shown,...
We present optical coherence micro-elastography, an improved form of compression elastography. demonstrate the capacity this technique to produce en face images, closely corresponding with histology, that reveal micro-scale mechanical contrast in human breast and lymph node tissues. use phase-sensitive, three-dimensional tomography (OCT) probe nanometer-to-micrometer-scale axial displacements tissues induced by compressive loading. Optical micro-elastography incorporates common-path...
We present the smallest reported side-viewing needle probe for optical coherence tomography (OCT). Design, fabrication, characterization, and initial application of a 30-gauge (outer diameter 0.31 mm) are demonstrated. Extreme miniaturization is achieved by using simple all-fiber design incorporating an angle-polished reflection-coated fiber-tip beam deflector. When inserted into biological tissue, aqueous interstitial fluids reduce probe's inherent astigmatism ratio to 1.8, resulting in...
Abstract Identifying tumour margins during breast-conserving surgeries is a persistent challenge. We have previously developed miniature needle probes that could enable intraoperative volume imaging with optical coherence tomography. In many situations, however, scattering contrast alone insufficient to clearly identify and delineate malignant regions. Additional polarization-sensitive measurements provide the means assess birefringence, which elevated in oriented collagen fibres may offer...
Abstract An accurate intraoperative identification of malignant tissue is a challenge in the surgical management breast cancer. Imaging techniques that help address this could contribute to more complete and tumor excision, thereby reduce current high reexcision rates without resorting removal excess healthy tissue. Optical coherence microelastography (OCME) three-dimensional, high-resolution imaging technique sensitive microscale variations mechanical properties As modifies tissue, OCME has...
We present optical palpation, a tactile imaging technique for mapping micrometer- to millimeter-scale mechanical variations in soft tissue. In stress sensor consisting of translucent, compliant silicone with known stress-strain behavior is placed on the tissue surface and compressive load applied. Optical coherence tomography (OCT) used measure local strain sensor, from which at sample calculated mapped onto an image. results tissue-mimicking phantoms, demonstrating detection feature...
Incomplete excision of malignant tissue is a major issue in breast-conserving surgery, with typically 20 -30% cases requiring second surgical procedure arising from postoperative detection an involved margin.We report advances the development new intraoperative tool, optical coherence micro-elastography, for assessment tumor margins on micro-scale.We demonstrate important step by conducting whole specimen imaging time frames wide-field scanning system acquiring mosaicked elastograms overall...
Measurements of upper airway size and shape are important in investigating the pathophysiology obstructive sleep apnea (OSA) devising, applying, determining effectiveness treatment modalities. We describe an endoscopic optical technique (anatomic coherence tomography, aOCT) that provides quantitative real-time imaging internal anatomy human airway.Validation studies were performed by comparing aOCT- computed tomography (CT)-derived measurements cross-sectional area (CSA) (1) conduits a wax...
We studied the effectiveness of some components a physiotherapy regimen on removal mucus from lungs 6 subjects with cystic fibrosis. On 5 randomized study days, after inhalation 99mTc-human serum albumin aerosol to label primarily large airways, lung radioactivity was measured during 40 min (a) spontaneous cough while at rest (control), (b) postural drainage, (c) drainage plus mechanical percussion, (d) combined maneuvers (postural deep breathing vibrations, and percussion) administered by...
Rationale: Our understanding of how airway remodeling affects regional elastic properties is limited due to technical difficulties in quantitatively measuring dynamic, vivo dimensions. Such knowledge could help elucidate mechanisms excessive narrowing.Objectives: To use anatomical optical coherence tomography (aOCT) compare central control subjects and those with obstructive lung diseases.Methods: After bronchodilation, lumen area (Ai) was measured using aOCT during bronchoscopy (n = 10)...
Optical coherence tomography (OCT) is a high-resolution imaging modality with the potential to provide in situ assessment distinguish normal from cancerous tissue. However, limited image penetration depth has restricted its utility. This paper demonstrates feasibility of an OCT needle probe perform interstitial deep below tissue surface. The side-facing comprises miniaturized focusing optics consisting no-core and GRIN fiber encased within either 22- or 23-gauge needle. 3-D volumetric data...