1. Articles from Jon Holmes

    1-16 of 16
    1. Vascular characteristics of port wine birthmarks as measured by dynamic optical coherence tomography

      Vascular characteristics of port wine birthmarks as measured by dynamic optical coherence tomography

      Background: Port wine birthmarks (PWB) are congenital capillary malformations. Vessel characteristics, such as diameter and depth, may impact presentation and outcomes. They can be imaged using dynamic optical coherence tomography (D-OCT), a high-resolution, non-invasive imaging method. Purpose: We conducted a cross-sectional observational study to measure in-vivo vascular characteristics as a function of PWB color. Methods: Patients undergoing treatment for PWB were recruited from three sites. PWB were classified by color, and D-OCT images with calculations were obtained. Results: 108 patients were enrolled. Mean age correlated with PWB color, with younger patients having lighter and older patients having darker birthmarks (p ...

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    2. Blood Vessel Density Measured Using Dynamic Optical Coherence Tomography is a Tool for Wound Healers

      Blood Vessel Density Measured Using Dynamic Optical Coherence Tomography is a Tool for Wound Healers

      Dynamic optical coherence tomography (D-OCT) is a relatively new technique that may be used to study the substructures in the retina, in the skin and its microcirculation. Furthermore, D-OCT is a validated method of imaging blood flow in skin microcirculation. The skin around venous and mixed arterio-venous ulcers was imaged and found to have tortuous vessels assumed to be angiogenic sprouts, and classified as dots, blobs, coils, clumps, lines, and curves. When these images were analyzed and measurements of vessel density were made, it was observed that the prevalence of coils and clumps in wound borders was significantly greater compared ...

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    3. Compensating optical coherence tomography scans

      Compensating optical coherence tomography scans

      A method of processing optical coherence tomography (OCT) scans, comprising: receiving OCT data comprising an OCT signal indicative of the level of scattering in a sample, the OCT data including the OCT signal for at least one scan through the sample, with the OCT signal having been measured at varying depth and position through the sample in each scan; processing the OCT data for each scan with depth to produce a indicative depth scan representative of the OCT signal at each depth through all of the scans; fitting a curve to the indicative depth scan, the curve comprising a first ...

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    4. Dynamic Optical Coherence Tomography of Cutaneous Blood Vessels in Melasma and Vessel Response to Oral Tranexamic Acid

      Dynamic Optical Coherence Tomography of Cutaneous Blood Vessels in Melasma and Vessel Response to Oral Tranexamic Acid

      Background and objectives: Melasma may be related to aberrant blood vessels, but there has been no report on the utility of dynamic optical coherence tomography (D-OCT) in studying vessel characteristics in melasma. We studied the characteristics of cutaneous blood vessels in melasma and the effects of oral tranexamic acid (TXA) with D-OCT. Study design/materials and methods: Six patients with moderate to severe melasma had a D-OCT scanning of the areas on the face affected by melasma and not affected by it. Three of them had scans within 3 months after starting oral TXA and at a follow-up visit. Blood ...

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    5. Morphometric Optical Imaging of Microporated Nail Tissue: An Investigation of Intermethod Agreement, Reliability, and Technical Limitations

      Morphometric Optical Imaging of Microporated Nail Tissue: An Investigation of Intermethod Agreement, Reliability, and Technical Limitations

      Background and Objectives While optical imaging is a useful technique to quantitate morphological differences and treatment effects, comparative investigations of the various techniques are lacking. This study aimed at evaluating intermethod agreement, reliability, and technical limitations of wide‐field microscopy (WFM), reflectance confocal microscopy (RCM), and optical coherence tomography (OCT) for morphometry by assessing fractionally ablated nail tissue. Study Design/Materials and Methods Fifty healthy nail clippings were processed with a fractionated CO 2 ‐laser (20 mJ/microbeam, density 15%), measured with calipers, and imaged using WFM, OCT, and RCM. Images were assessed for nail plate thickness, micropore dimensions, degree ...

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    6. OCT Image-Guided Treatment of Scars (Book Chapter)

      OCT Image-Guided Treatment of Scars (Book Chapter)

      Improved scar rehabilitation is achieved with lasers by matching laser settings to heterogeneous thickness of fibrous pathology. Optical coherence tomography (OCT) provides accurate depth measurement and demonstrates vascularity in scar and healthy tissue noninvasively providing a clinical endpoint for optimally calculating dosimetry. Real-time imaging during treatment allows personalized treatment due to varying collagen densities in cicatricial tissues

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    7. Dynamic Optical Coherence Tomography Is a New Technique for Imaging Skin Around Lower Extremity Wounds

      Dynamic Optical Coherence Tomography Is a New Technique for Imaging Skin Around Lower Extremity Wounds

      Chronic wounds such as venous leg ulcers invariably heal slowly and recur. In the case of venous leg ulcers, poor healing of chronic wounds is variously attributed to ambulatory hypertension, impaired perfusion and diffusion, presence of chronic inflammation at wound sites, lipodermatosclerosis, and senescence. The aim of this study was to investigate whether a new technique, optical coherence tomography (OCT), which permits imaging of blood capillaries in the peri-wound skin, can provide new insights into the pathology. OCT and its recent variant, dynamic OCT, permit rapid noninvasive depth-resolved imaging of the capillaries in the superficial dermis via a handheld probe ...

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    8. Advances in optical coherence tomography in dermatology—a review

      Advances in optical coherence tomography in dermatology—a review

      Optical coherence tomography (OCT) was introduced as an imaging system, but like ultrasonography, other measures, such as blood perfusion and polarization of light, have enabled the technology to approach clinical utility. This review aims at providing an overview of the advances in clinical research based on the improving technical aspects. OCT provides cross-sectional and en face images down to skin depths of 0.4 to 2.00 mm with optical resolution of 3 to 15  μm. Dynamic optical coherence tomography (D-OCT) enables the visualization of cutaneous microvasculature via detection of rapid changes in the interferometric signal of blood flow. Nonmelanoma ...

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    9. Angiographic optical coherence tomography imaging of hemangiomas and port wine birthmarks

      Angiographic optical coherence tomography imaging of hemangiomas and port wine birthmarks

      Objectives A current therapeutic challenge of vascular lesions is that they do not always respond effectively to laser treatment. Information on targeted vessels could potentially be used to guide laser treatments. Optical coherence tomography (OCT) is a useful tool for the non‐invasive imaging of tissues, including skin hemangiomas and port wine birthmarks. Dynamic OCT is able to rapidly characterize cutaneous blood vessels. The primary goal of this study was to demonstrate the ability of bedside OCT to image (i) overall vessel pattern; (ii) individual vessel morphology, diameter and depth; and (iii) total vessel density as a function of depth ...

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    10. Elastographic contrast generation in optical coherence tomography from a localized shear stress

      Elastographic contrast generation in optical coherence tomography from a localized shear stress
      A technique for generating contrast in two-dimensional shear strain elastograms from a localized stress is presented. The technique involves generating a non-uniform, localized stress via a magnetically actuated implant. Its effectiveness is demonstrated using finite-element simulations and a phantom study provides experimental verification of this. The method is applied to a superficial cancerous lesion model represented as a stiff inclusion in normal tissue. The lesion was best distinguished from its surroundings using total shear strain elastograms, rather than individual strain components. In experimental phantom studies, the lesion was imaged using optical coherence tomography (OCT) and could still be distinguished in ...
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    11. OCT technology development: Where are we now? A commercial perspective

      The field of optical coherence tomography (OCT) has grown enormously since its inception in 1991 at MIT, encompassing many areas of imaging research. Improvements in the optical technology used in OCT systems, and in the design of the OCT interferometers and probes, has resulted in steadily improving image quality and more practical probe designs. Successful commercial application of OCT occurred first in retina imaging, and many further applications now appear ripe for translation from the laboratory to the marketplace. In this paper, I review this translation process from a commercial perspective, and attempt to draw helpful conclusions. (© 2009 WILEY-VCH Verlag ...
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    12. Novel optical-signal acquisition method addresses grand challenges for silicon technology

      Novel optical-signal acquisition method addresses grand challenges for silicon technology
      The superior image definition and nondestructive testing technology provided by optical-coherence tomography targets the characterization issues posed by nanometer-scale devices. The UK's Engineering and Physical Sciences Research Council's recent consultation exercise1 reinforced the belief that future silicon technology will be advanced by new and evolving characterization techniques. Among the grand challenges identified are the development and implementation of nanometer-scale features, 3D structures, and manufacturing quality. The developing market for microelectromechanical systems (MEMS)—which integrate mechanical elements, sensors, actuators, and electronics on a common silicon substrate—provides a proof statement. Driven by the demand for smaller, cheaper, more versatile ...
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    13. Multi-channel Fourier domain OCT system with superior lateral resolution for biomedical applications

      Jon Holmes, Simon Hattersley, Nick Stone et al. The lateral resolution of Fourier domain optical coherence tomography (FD-OCT) systems is limited by the depth of focus that can be achieved over the desired imaging depth at the chosen wavelength. Various solutions have been proposed such as Bessel beams and computational methods; however these suf ... [Proc. SPIE Int. Soc. Opt. Eng. 6847, 68470O (2008)] published Mon Feb 18, 2008.
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    1-16 of 16
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  2. Topics in the News

    1. (16 articles) Michelson Diagnostics
    2. (2 articles) UK National Physical Laboratory
    3. (2 articles) University of Southampton
    4. (2 articles) University of Copenhagen
    5. (1 articles) UC Irvine
    6. (1 articles) Gloucestershire Royal Hospital
    7. (1 articles) University of Miami
    8. (1 articles) University of Connecticut
    9. (1 articles) University of Manchester
    10. (1 articles) Shanghai Jiao Tong University
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    Novel optical-signal acquisition method addresses grand challenges for silicon technology Elastographic contrast generation in optical coherence tomography from a localized shear stress OCT Lines up for Dermatology Angiographic optical coherence tomography imaging of hemangiomas and port wine birthmarks Advances in optical coherence tomography in dermatology—a review Dynamic Optical Coherence Tomography Is a New Technique for Imaging Skin Around Lower Extremity Wounds Successful Utilization of Optical Coherence Tomography as a Non-Invasive, Bedside Imaging Technique To Identify Residual Nodular Basal Cell Carcinoma at Well-Healed and Clinically Unidentifiable Biopsy Site Morphometric Optical Imaging of Microporated Nail Tissue: An Investigation of Intermethod Agreement, Reliability, and Technical Limitations Structural abnormalities associated with glaucoma using swept-source optical coherence tomography in patients with systemic sclerosis Clinical presentation does not affect acute mechanical performance of the Novolimus-eluting bioresorbable vascular scaffold as assessed by optical coherence tomography Evaluating optical coherence tomography (OCT) findings as potential biomarkers in central nervous system (CNS) lymphoma with or without ocular involvement Polarization sensitive optical coherence tomography with single input for imaging depth-resolved collagen organizations