1. Articles from Arnaud Dubois

    1-24 of 28 1 2 »
    1. Co-localized line-field confocal optical coherence tomography and confocal Raman microspectroscopy for three-dimensional high-resolution morphological and molecular characterization of skin tissues ex vivo

      Co-localized line-field confocal optical coherence tomography and confocal Raman microspectroscopy for three-dimensional high-resolution morphological and molecular characterization of skin tissues ex vivo

      Line-field confocal optical coherence tomography (LC-OCT) is an optical modality that provides three-dimensional (3D) images of the skin at cellular resolution. Confocal Raman microspectroscopy (CRM) is a label-free optical technique that can provide point measurement of the molecular content of the skin. This work presents a method to co-localize LC-OCT and CRM acquisitions for morpho-molecular analysis of ex vivo skin tissues at cellular level. The co-localization method allows acquisition of Raman spectra at specific locations in a sample identified from a 3D LC-OCT image, with an accuracy of ± 20 µm. The method was applied to the characterization of tattooed skin ...

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    2. Non-invasive scoring of cellular atypia in keratinocyte cancers in 3D LC-OCT images using Deep Learning

      Non-invasive scoring of cellular atypia in keratinocyte cancers in 3D LC-OCT images using Deep Learning

      Diagnosis based on histopathology for skin cancer detection is today's gold standard and relies on the presence or absence of biomarkers and cellular atypia. However it suffers drawbacks: it requires a strong expertise and is time-consuming. Moreover the notion of atypia or dysplasia of the visible cells used for diagnosis is very subjective, with poor inter-rater agreement reported in the literature. Lastly, histology requires a biopsy which is an invasive procedure and only captures a small sample of the lesion, which is insufficient in the context of large fields of cancerization. Here we demonstrate that the notion of cellular ...

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    3. Line-field confocal optical coherence tomography as a tool for three-dimensional in vivo quantification of healthy epidermis: a pilot study

      Line-field confocal optical coherence tomography as a tool for three-dimensional in vivo quantification of healthy epidermis: a pilot study

      Epidermal three-dimensional (3D) topography/quantification have not been completely characterized yet. The recently developed line-field confocal optical coherence tomography (LC-OCT) provides real-time, high-resolution, in-vivo 3D imaging of the skin. This pilot study aimed at quantifying epidermal metrics [epidermal thicknesses, dermal-epidermal junction (DEJ) undulation and keratinocyte number/shape/size] using 3D LC-OCT. For each study participant (8 female, skin-type-II, younger/older volunteers), seven body sites were imaged with LC-OCT. Epidermal metrics were calculated by segmentations and measurements assisted by artificial intelligence (AI) when appropriate. Thicknesses of epidermis/SC, DEJ undulation and keratinocyte nuclei volume varied across body sites. Evidence of keratinocyte ...

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    4. Line-field confocal optical coherence tomography for three-dimensional skin imaging

      Line-field confocal optical coherence tomography for three-dimensional skin imaging

      This paper reports on the latest advances in line-field confocal optical coherence tomography (LC-OCT), a recently invented imaging technology that now allows the generation of either horizontal ( x × y ) section images at an adjustable depth or vertical ( x × z ) section images at an adjustable lateral position, as well as three-dimensional images. For both two-dimensional imaging modes, images are acquired in real-time, with real-time control of the depth and lateral positions. Three-dimensional ( x × y × z ) images are acquired from a stack of horizontal section images. The device is in the form of a portable probe. The handle of the probe has ...

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    5. Mirau-based line-field confocal optical coherence tomography

      Mirau-based line-field confocal optical coherence tomography

      Line-field confocal optical coherence tomography (LC-OCT) is an imaging technique in which A-scans are acquired in parallel through line illumination with a broadband laser and line detection with a line-scan camera. B-scan imaging at high spatial resolution is achieved by dynamic focusing in a Linnik interferometer. This paper presents an LC-OCT device based on a custom-designed Mirau interferometer that offers similar spatial resolution and detection sensitivity. The device has the advantage of being more compact and lighter. In vivo imaging of human skin with a resolution of 1.3 µm × 1.1 µm (lateral × axial) is demonstrated over a field ...

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      Mentions: Damae Medical
    6. Dual-mode line-field confocal optical coherence tomography for ultrahigh-resolution vertical and horizontal section imaging of human skin in vivo

      Dual-mode line-field confocal optical coherence tomography for ultrahigh-resolution vertical and horizontal section imaging of human skin in vivo

      Line-field confocal optical coherence tomography (LC-OCT) is a recently introduced technique for ultrahigh-resolution vertical section (B-scan) imaging of human skin in vivo . This work presents a new implementation of the LC-OCT technique to obtain horizontal section images (C-scans) in addition to B-scans. C-scan imaging is achieved with this dual-mode LC-OCT system using a mirror galvanometer for lateral scanning along with a piezoelectric chip for modulation of the interferometric signal. A quasi-identical spatial resolution of ∼ 1 µm is measured for both B-scans and C-scans. The images are acquired in both modes at a rate of 10 frames per second. The horizontal ...

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      Mentions: Damae Medical
    7. Comparison of line‐field confocal optical coherence tomography images with histological sections: Validation of a new method for in vivo and non‐invasive quantification of superficial dermis thickness

      Comparison of line‐field confocal optical coherence tomography images with histological sections: Validation of a new method for in vivo and non‐invasive quantification of superficial dermis thickness

      Background Line‐field confocal optical coherence tomography (LC‐OCT) is an imaging technique providing “optical biopsies” of the skin in real time and non‐invasively. At a center optical wavelength of 1.3 µm, this innovative technology can be applied to dermo‐cosmetic product development due to both high image resolution (~2 µm) and sufficient penetration (~0.5 mm). Nevertheless, the precise dermal area analyzed with LC‐OCT has never been identified. In this study, the objective was to compare LC‐OCT images with histological sections of the same area, in order to validate a new method for in vivo ...

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    8. Simultaneous dual-band line-field confocal optical coherence tomography: application to skin imaging

      Simultaneous dual-band line-field confocal optical coherence tomography: application to skin imaging

      Line-field confocal optical coherence tomography (LC-OCT) operating in two distinct spectral bands centered at 770 nm and 1250 nm is reported, using a single supercontinuum light source and two different line-scan cameras. B-scans are acquired simultaneously in the two bands at 4 frames per second. Greyscale representation and color fusion of the images are performed to either produce a single image with both high resolution (1.3 µm × 1.2 µm, lateral × axial, measured at the surface) in the superficial part of the image and deep penetration, or to highlight the spectroscopic properties of the sample. In vivo images of ...

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    9. Line-field confocal time-domain optical coherence tomography with dynamic focusing

      Line-field confocal time-domain optical coherence tomography with dynamic focusing

      A time-domain optical coherence tomography technique is introduced for high-resolution B-scan imaging in real-time. The technique is based on a two-beam interference microscope with line illumination and line detection using a broadband spatially coherent light source and a line-scan camera. Multiple (2048) A-scans are acquired in parallel by scanning the sample depth while adjusting the focus. Quasi-isotropic spatial resolution of 1.3 µm × 1.1 µm (lateral × axial) is achieved. In vivo cellular-level resolution imaging of human skin is demonstrated at 10 frames per second with a penetration depth of ∼500 µm.

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      Mentions: Damae Medical
    10. Line-field confocal optical coherence tomography for high-resolution noninvasive imaging of skin tumors

      Line-field confocal optical coherence tomography for high-resolution noninvasive imaging of skin tumors

      An optical technique called line-field confocal optical coherence tomography (LC-OCT) is introduced for high-resolution, noninvasive imaging of human skin in vivo . LC-OCT combines the principles of time-domain optical coherence tomography and confocal microscopy with line illumination and detection using a broadband laser and a line-scan camera. LC-OCT measures the echo-time delay and amplitude of light backscattered from cutaneous microstructures through low-coherence interferometry associated with confocal spatial filtering. Multiple A-scans are acquired simultaneously while dynamically adjusting the focus. The resulting cross-sectional B-scan image is produced in real time at 10  frame  /  s. With an isotropic spatial resolution of ∼1  μm, the ...

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      Mentions: Damae Medical
    11. A compact high‐speed full‐field optical coherence microscope for high‐resolution in vivo skin imaging

      A compact high‐speed full‐field optical coherence microscope for high‐resolution in vivo skin imaging

      A compact high‐speed full‐field optical coherence microscope has been developed for high‐resolution in vivo imaging of biological tissues. The interferometer, in the Linnik configuration, has a size of 11×11×5 cm 3 and a weight of 210 g. Full‐field illumination with low‐coherence light is achieved with a high‐brightness broadband light‐emitting diode. High‐speed full‐field detection is achieved by using part of the image sensor of a high‐dynamic range CMOS camera. En face tomographic images are acquired at a rate of 50 Hz, with an integration time of 0.9 ms ...

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    12. Advances in optical coherence tomography for dermatology

      Advances in optical coherence tomography for dermatology

      This paper reports on advances in optical coherence tomography (OCT) for application in dermatology. Full-field OCT is a particular approach of OCT based on white-light interference microscopy. FF-OCT produces en face tomographic images by arithmetic combination of interferometric images acquired with an area camera and by illuminating the whole field of view with low-coherence light. The major interest of FF-OCT lies in its high imaging spatial resolution (∼ 1.0 µm) in both lateral and axial directions, using a simple and robust experimental arrangement. Line-field OCT (LFOCT) is a recent evolution of FF-OCT with line illumination and line detection using a ...

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    13. Focus defect and dispersion mismatch in full-field optical coherence microscopy

      Focus defect and dispersion mismatch in full-field optical coherence microscopy

      Full-field optical coherence microscopy (FFOCM) is an optical technique, based on low-coherence interference microscopy, for tomographic imaging of semi-transparent samples with micrometer-scale spatial resolution. The differences in refractive index between the sample and the immersion medium of the microscope objectives may degrade the FFOCM image quality because of focus defect and optical dispersion mismatch. These phenomena and their consequences are discussed in this theoretical paper. Experimental methods that have been implemented in FFOCM to minimize the adverse effects of these phenomena are summarized and compared.

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    14. A simplified algorithm for digital fringe analysis in two-wave interferometry with sinusoidal phase modulation

      A simplified algorithm for digital fringe analysis in two-wave interferometry with sinusoidal phase modulation

      A compact simplified algorithm for digital detection of the amplitude and phase of the interferometric signal delivered by a two-wave interferometer with sinusoidal phase modulation is presented. The algorithm consists of simple mathematical combinations of four frames obtained by integration by a camera of the time-varying intensity in an interference pattern during the four successive quarters of the modulation period. The algorithm is invariant by circular permutation of the four image frames. Any set of four consecutive frames can be used for the calculations, which simplifies the practical implementation of the method. A numerical simulation has been carried out to ...

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    15. Handbook of Full-Field Optical Coherence Microscopy: Technology and Applications (Textbook)

      Handbook of Full-Field Optical Coherence Microscopy: Technology and Applications (Textbook)

      Full-field optical coherence microscopy (FF-OCM) is an imaging technique that provides cross-sectional views of the subsurface microstructure of semitransparent objects. The technology is based on low-coherence interference microscopy, which uses an area camera for en face imaging of the full-field illuminated object. FF-OCM benefits from the lateral imaging resolution of optical microscopy along with the capacity of optical axial sectioning at micrometer-scale resolution. The technique can be employed in diverse applications, in particular for non-invasive examination of biological tissues. This handbook is the first to be entirely devoted to FF-OCM. It is organized into four parts with a total of ...

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    16. Full-field optical coherence microscopy with optimized ultrahigh spatial resolution

      Full-field optical coherence microscopy with optimized ultrahigh spatial resolution

      Full-field optical coherence microscopy (FF-OCM) with isotropic spatial resolution of 0.5 μm (in water), at 700 nm center wavelength, is reported. A theoretical study of the FF-OCM axial response is carried out for maximizing the axial resolution of the system, considering the effect of optical dispersion. The lateral resolution is optimized by using water-immersion microscope objectives with a numerical aperture of 1.2. This ultrahigh-resolution FF-OCM system is applied to animal and human skin tissue imaging, revealing ultra-fine in-depth structures at the sub-cellular level.

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    17. Wide-field, full-field optical coherence microscopy for high-axial-resolution phase and amplitude imaging

      Wide-field, full-field optical coherence microscopy for high-axial-resolution phase and amplitude imaging

      An original single-objective, full-field optical coherence microscopy system is reported that is capable of imaging both the phase and the amplitude of semi-transparent samples over a field of view of 17.5     mm × 17.5     mm with an axial sectioning resolution of 1.5 μm. A special stack acquisition arrangement ensures optimal reachable imaging depth. Several phase-shifting interferometry algorithms for phase measurement with broadband light are compared theoretically and experimentally. Using the phase information, noninvasive depth-resolved topographic images of multilayer samples are produced to characterize each layer by measuring their defects and curvature with a nanometric scale precision. Using the ...

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    18. Ultrahigh resolution spectral-domain optical coherence tomography at 1.3 μm using a broadband superluminescent diode light source

      Ultrahigh resolution spectral-domain optical coherence tomography at 1.3 μm using a broadband superluminescent diode light source

      We present an ultrahigh resolution spectral-domain optical coherence tomography imaging system using a broadband superluminescent diode light source emitting at a center wavelength of 1.3 μm. The light source consists of two spectrally shifted superluminescent diodes that are coupled together into a single mode fiber. The effective emission power spectrum has a full width at half maximum of 200 nm and the source output power is 10 mW. The imaging system has an axial resolution of 3.9 μm in air (<3.0 μm in biological tissue), and a lateral resolution of 6.5 μm. The sensitivity and the ...

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    19. Extended full-field optical coherence microscopy

      Extended full-field optical coherence microscopy

      Full-field optical coherence microscopy (FF-OCM) is a recent optical technology based on low-coherence interference microscopy for semi-transparent sample imaging with ~ 1 μm spatial resolution. FF-OCM has been successfully applied to three-dimensional imaging of various biological tissues at cellular-level resolution. The contrast of FF-OCM images results from the intensity of light backscattered by the sample microstructures. This contrast mechanism, based on refractive index changes, provides information on the internal architectural morphology of the sample. In this paper, we present a multimodal FF-OCM system, capable of measuring simultaneously the intensity, the power spectrum and the phase-retardation of light backscattered by the sample ...

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    20. Simultaneous optically sectioned fluorescence and optical coherence microscopy with full-field illumination

      Simultaneous optically sectioned fluorescence and optical coherence microscopy with full-field illumination

      Full-field optical coherence microscopy (FF-OCM) and optically sectioned fluorescence microscopy are two imaging techniques that are implemented here in a novel dual modality instrument. The two imaging modalities use a broad field illumination to acquire the entire field of view without raster scanning. Optical sectioning is achieved in both imaging modalities owing to the coherence gating property of light for FF-OCM, and a structured illumination setup for fluorescence microscopy. Complementary image data are provided by the dual modality instrument in the context of biological tissue screening. FF-OCM imaging modality shows the tissue microarchitecture, while fluorescence microscopy highlights specific tissue features ...

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    21. Guiding glaucoma laser surgery using Fourier-domain optical coherence tomography at 1.3 μm

      Guiding glaucoma laser surgery using Fourier-domain optical coherence tomography at 1.3 μm

      Glaucoma is a disease of the optic nerve that is usually associated with an increased internal pressure of the eye and can lead to a decreased vision and eventually blindness. It is the second leading cause of blindness worldwide with more than 80 million people affected and approximately 6 million blind. The standard clinical treatment for glaucoma, after unsuccessful administration of eyedrops and other treatments, is performing incisional surgery. However, due to post-surgical complications like scarring and wound healing, this conventional method has a global success rate of only about 60%. In comparison, as femtosecond laser surgery may be performed ...

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    22. Spectroscopic polarization-sensitive full-field optical coherence tomography

      Spectroscopic polarization-sensitive full-field optical coherence tomography

      Full-field optical coherence tomography (FF-OCT) is a recent optical imaging technology based on low-coherence interference microscopy for imaging of semi-transparent samples with ~1 µm spatial resolution. FF-OCT produces en-face tomographic images obtained by arithmetic combination of interferometric images acquired by an array camera. In this paper, we demonstrate a unique multimodal FF-OCT system, capable of measuring simultaneously the intensity, the power spectrum and the phase-retardation of light backscattered by the sample being imaged. Compared to conventional FF-OCT, this multimodal system provides enhanced imaging contrasts at the price of a moderate increase in experimental complexity and cost.

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    23. Full-field optical coherence tomography at 800 nm and 1300 nm simultaneously

      Full-field optical coherence tomography at 800 nm and 1300 nm simultaneously
      Optical coherence tomography (OCT) is a technique of choice for micrometer-scale resolution imaging of biological specimens [1,2]. Full-field optical coherence tomography (FF-OCT) was introduced a few years ago as an alternative method to conventional OCT. FF-OCT is based on an interference microscope with a camera as an array detector combined with a low coherence illumination source for parallel acquisition of en-face oriented tomographic images [3- 5]. FF-OCT is a technique of choice for noninvasive three-dimensional imaging of ex vivo biological tissues with ultrahigh spatial resolution (~ 1 µm) [6,7]. FF-OCT is based on phase-shifting interferometry: several interferometric images are ...
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    24. Study and suppression of motion artifacts in full-field optical coherence tomography

      Study and suppression of motion artifacts in full-field optical coherence tomography
      Delphine Sacchet, Julien Moreau, Patrick Georges et al. Significant motion artifacts limit performance of conventional full-field optical coherence tomography for in vivo imaging. A theoretical and experimental study of those limitations is presented and a new FF-OCT system suppressing most of artifacts due to sample motions is demonstrated using instant ... [Proc. SPIE 7715, 77150A (2010)] published Fri May 14, 2010.
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    1-24 of 28 1 2 »
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    Spectroscopic ultrahigh-resolution full-field optical coherence microscopy Simultaneous dual-band ultra-high resolution full-field optical coherence tomography Motion artifact suppression in full-field optical coherence tomography Study and suppression of motion artifacts in full-field optical coherence tomography Full-field optical coherence tomography at 800 nm and 1300 nm simultaneously Spectroscopic polarization-sensitive full-field optical coherence tomography Simultaneous optically sectioned fluorescence and optical coherence microscopy with full-field illumination Extended full-field optical coherence microscopy Ultrahigh resolution spectral-domain optical coherence tomography at 1.3 μm using a broadband superluminescent diode light source Optical coherence tomography findings in patients with transfusion-dependent β-thalassemia Higher-order regression three-dimensional motion-compensation method for real-time optical coherence tomography volumetric imaging of the cornea Optical coherence tomography image based eye disease detection using deep convolutional neural network