1. Pete H. Tomlins

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    1. Mentioned In 33 Articles

    2. Scanning Methods And Apparatus

      Scanning Methods And Apparatus

      There is provided a method of identifying a region of interest in sample. The method comprises obtaining one or more optical coherence tomography (OCT) axial scans at one or more locations over the sample surface; for each axial scan, determining an integrated total of OCT intensity over the depth of the scan, and determining an attenuation depth into the sample at which a predetermined fraction of the integrated total is reached; and determining the from the one or more attenuation depths a region of interest in the sample. Generally, the method does not rely the accuracy (or inaccuracy) of any ...

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    3. Multi-system comparison of optical coherence tomography performance with point spread function phantoms

      Multi-system comparison of optical coherence tomography performance with point spread function phantoms

      Point spread function (PSF) phantoms based on unstructured distributions of sub-resolution particles in a transparent matrix have proven effective for evaluating resolution and its spatial variation in optical coherence tomography (OCT) systems. Measurements based on PSF phantoms have the potential to become a standard test method for consistent, objective and quantitative inter-comparison of OCT system performance. Towards this end, we have evaluated three PSF phantoms and investigated their ability to compare the performance of four OCT systems. The phantoms are based on 260-nm-diameter gold nanoshells, submicron-diameter iron oxide particles and 1.5-micron-diameter silica particles. The OCT systems included spectral-domain and ...

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    4. Quantitative optical coherence tomography of fluid-filled oral mucosal lesions

      Quantitative optical coherence tomography of fluid-filled oral mucosal lesions

      The decision of selecting the most representative site for the biopsy of fluid-filled lesions can be difficult. This may be attributed to the poor delineation of the correct lesional site by clinical observation alone. In this study, optical coherence tomography is used to quantify the contrast between solid- and fluid-filled lesions by measuring the light intensity change at the tissue–fluid interface (intensity drop). This parameter was measured from sequential axial scans (n ≈ 106 per sample) of 3D optical coherence tomography (OCT) datasets from control tissues (n = 14) and fluid-filled lesions (n = 7) and displayed as a 2D-scaled intensity drop ...

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    5. Scanning Methods And Apparatus

      Scanning Methods And Apparatus

      There is provided a method of identifying a region of interest in sample. The method comprises obtaining one or more optical coherence tomography (OCT) axial scans at one or more locations over the sample surface; for each axial scan, determining an integrated total of OCT intensity over the depth of the scan, and determining an attenuation depth into the sample at which a predetermined fraction of the integrated total is reached; and determining from the one or more attenuation depths a region of interest in the sample. Generally, the method does not rely the accuracy (or inaccuracy) of any particular ...

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    6. Feature Of The Week 2/5/12: Queen Mary University of London Researchers Investigate Quantitative Analysis of OCT and Histopathology Images of Normal and Dysplastic Oral Mucosal Tissues

      Feature Of The Week 2/5/12: Queen Mary University of London Researchers Investigate Quantitative Analysis of OCT and Histopathology Images of Normal and Dysplastic Oral Mucosal Tissues

      Selecting the most representative site for biopsy is crucial in establishing a definitive diagnosis of oral epithelial dysplasia. The current process involves clinical examination that can be subjective and prone to sampling errors. The aim of this study was therefore to investigate the use of optical coherence tomography (OCT) for differentiation of normal and dysplastic oral epithelial samples, with a view to developing an objective and reproducible approach for biopsy site selection. Biopsy samples from patients with fibro-epithelial polyps (n = 13), mild dysplasia (n = 2), and moderate/severe dysplasia (n = 4) were scanned at 5-μm intervals using an OCT microscope ...

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    7. OCT Phantoms Initiative: A new effort to bring standardized tools for OCT system characterization and validation to the community

      OCT Phantoms Initiative: A new effort to bring standardized tools for OCT system characterization and validation to the community
      ...nistration Brendan Kennedy, University of Western Australia Guy Lamouche, National Research Council Canada Pete Tomlins, Queen Mary, University of London   If you are attending Photonics West this week, please come ...
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    8. Feature Of The Week 1/8/12: Ultrafast Processing and Rendering of OCT Data using a GPU

      Feature Of The Week 1/8/12: Ultrafast Processing and Rendering of OCT Data using a GPU
      Processing of the large volumetric data is the bottleneck of the current FD-OCT systems. Solving this issue enables real time visualisation. Various groups have applied utilising the full power of GPU for OCT data processing allows to realise the full potential of OCT. GPU based data processing to OCT. Here we present a GPU-CPU based processing methodology as well evaluates the performance of various GPUs.In standard processing, interference data are copied to GPU and entire computation is carried out on GPU. Processed data are stored in GPU memory, which allows rendering and visualising the data.To benchmark the processing ...
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    9. Estimating the resolution of a commercial optical coherence tomography system with limited spatial sampling

      Estimating the resolution of a commercial optical coherence tomography system with limited spatial sampling
      Optical coherence tomography (OCT) is becoming increasingly widespread as an experimental tool for clinical investigation, facilitated by the development of commercial instruments. In situ performance evaluation of such 'black box' systems presents a challenge, where the instrument hardware and software can limit access to important configuration parameters and raw data. Two key performance metrics for imaging systems are the point-spread function (PSF) and the associated modulation transfer function (MTF). However, previously described experimental measurement techniques assume user-variable spatial sampling and may not be appropriate for the characterization of deployed commercial instruments. Characterization methods developed for other modalities do not address ...
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    10. Femtosecond laser micro-inscription of optical coherence tomography resolution test artifacts

      Femtosecond laser micro-inscription of optical coherence tomography resolution test artifacts
      Optical coherence tomography (OCT) systems are becoming more commonly used in biomedical imaging and, to enable continued uptake, a reliable method of characterizing their performance and validating their operation is required. This paper outlines the use of femtosecond laser subsurface micro-inscription techniques to fabricate an OCT test artifact for validating the resolution performance of a commercial OCT system. The key advantage of this approach is that by utilizing the nonlinear absorption a three dimensional grid of highly localized point and line defects can be written in clear fused silica substrates.
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    11. The modulation transfer function of an optical coherence tomography imaging system in turbid media

      The modulation transfer function of an optical coherence tomography imaging system in turbid media
      In this paper we describe measurements of the contrast transfer function, modulation transfer function and point-spread function of an optical coherence tomography (OCT) imaging system through scattering layers having a dimension-less scattering depth over the range 0.2–6.9. The results were found to be insensitive to scattering density, indicating that these measurement parameters alone do not well characterize the practical imaging ability of an OCT instrument. Attenuation and increased noise floor due to optical scattering were found to be the primary imaging limit and the effect of multiple scattering on OCT resolution was negligible.
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    12. 1-15 of 33 1 2 3 »
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  2. About Pete H. Tomlins

    Pete H. Tomlins

    Pete Tomlins is at Queen Mary University of London.  Formerly, Dr. Tomlins was a Senior Scientist in the Optical Technologies Group at the UK’s National Physical Laboratory (NPL), where he leads a portfolio of projects in biomedical optics. His primary research interest is in quantitative OCT and understanding the physical origin of contrast in OCT images. A particular interest is cell and tissue optics where Pete is developing experimental methods to determine the spatially distributed optical properties of human tissue, correlating these with the presence and progress of disease. Optical properties of particular interest are refractive index, dispersion, absorption and scattering. A multiple-angle variant of OCT has been developed by Pete Tomlins group to perform these measurements, along with computational models and optical phantoms. Further interests include tissue engineering, where Pete has used Doppler OCT to determine the complex fluid flow within artificial tissue scaffolds, and dental composites research.

    Pete manages a number of collaborations with leading commercial and research organisation, and plans to increase the number and scope of such partnerships along with the activity at NPL.

  3. Quotes

    1. We anticipate that eventually such phantoms will be shipped with OCT systems when they are used clinically, together with a set of guidelines highlighting how they are to be used.
      In Spotting the signs: Improving resolution of systems used to image human tissue could help early identification of life-threatening diseases
    2. By removing the point-spread function from the data, we have actually seen an improvement of several microns in resolution of an OCT instrument, which is very exciting. We have demonstrated that you can now resolve two points that previously couldn't be resolved.
      In Spotting the signs: Improving resolution of systems used to image human tissue could help early identification of life-threatening diseases