1. Maciej Wojtkowski

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    1. Mentioned In 119 Articles

    2. In vivo imaging of human cornea with highspeed and high-resolution Fourier-domain full-field optical coherence tomography

      In vivo imaging of human cornea with highspeed and high-resolution Fourier-domain full-field optical coherence tomography
      : Corneal evaluation in ophthalmology necessitates cellular-resolution and fast imaging techniques allowing accurate diagnoses. Currently, the fastest volumetric imaging technique is Fourier-domain full-field optical coherence tomography (FD-FF-OCT) that uses a fast camera and a rapidly tunable laser source. Here, we demonstrate high-resolution, highspeed, non-contact corneal volumetric imaging in vivo with FD-FF-OCT that can acquire a single 3D volume with a voxel rate of 7.8 GHz. The spatial coherence of the ...
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    3. In vivo brain imaging with multimodal optical coherence microscopy in a mouse model of thromboembolic photochemical stroke

      In vivo brain imaging with multimodal optical coherence microscopy in a mouse model of thromboembolic photochemical stroke
      We used a new multimodal imaging system that combines optical coherence microscopy and brightfield microscopy. Using this in vivo brain monitoring approach and cranial window implantation, we three-dimensionally visualized the vascular network during thrombosis, with high temporal (18 s) and spatial (axial, 2.5m; lateral, 2.2m) resolution. We used a modified mouse model of photochemical thromboembolic stroke in order to more accurately parallel human stroke. Specifically, we applied green ...
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    4. Computational aberration correction in spatiotemporal optical coherence (STOC) imaging

      Computational aberration correction in spatiotemporal optical coherence (STOC) imaging
      Spatiotemporal optical coherence (STOC) imaging is a new technique for suppressing coherent crosstalk noise in Fourier-domain full-field optical coherence tomography (FD-FF-OCT). In STOC imaging, the timevarying inhomogeneous phase masks modulate the incident light to alter the interferometric signal. Resulting interference images are then processed as in standard FDFF-OCT and averaged incoherently or coherently to produce crosstalk-free volumetric OCT images of the sample. Here, we show that coherent averaging is suitable ...
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    5. Crosstalk-free volumetric in vivo imaging of a human retina with Fourier-domain full-field optical coherence tomography

      Crosstalk-free volumetric in vivo imaging of a human retina with Fourier-domain full-field optical coherence tomography
      Fourier-domain full-field optical coherence tomography (FD-FF-OCT) is currently the fastest volumetric imaging technique that is able to generate a single 3-D volume of retina in less than 9 ms, corresponding to a voxel rate of 7.8 GHz. FD-FF-OCT is based on a fast camera, a rapidly tunable laser source, and Fourier-domain signal detection. However, crosstalk appearing due to multiply scattered light corrupts images with the speckle pattern, and therefore ...
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    6. Feature Of The Week 05/26/2019: In vivo volumetric imaging by crosstalk-free full-field OCT

      Feature Of The Week 05/26/2019: In vivo volumetric imaging by crosstalk-free full-field OCT
      Cellular resolution imaging of biological structures has always been a challenge due to strong scattering that limits the achievable transverse resolution or imaging penetration depth. Recently, a major advancement toward high-resolution and volumetric imaging was achieved by implementing a parallel detection (i.e., full field) into Fourier-domain optical coherence tomography. The drawback of using parallel detection is that scattered light can travel laterally and get mapped improperly at a camera ...
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    7. In vivo volumetric imaging by crosstalk-free full-field OCT

      In vivo volumetric imaging by crosstalk-free full-field OCT
      Cellular resolution imaging of biological structures has always been a challenge due to strong scattering that limits the achievable transverse resolution or imaging penetration depth. Recently, a major advancement toward high-resolution and volumetric imaging was achieved by implementing a parallel detection (i.e., full field) into Fourier-domain optical coherence tomography. The drawback of using parallel detection is that scattered light can travel laterally and get mapped improperly at a camera ...
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    8. Air-Puff-Induced Dynamics of Ocular Components Measured with Optical Biometry

      Air-Puff-Induced Dynamics of Ocular Components Measured with Optical Biometry
      Purpose : To analyze the dynamics of all optical components of the eye and the behavior of the eyeball under air-puff conditions in vivo. To determine the impact of the intraocular pressure (IOP) on the air-puff-induced deformation of the eye. Methods : Twenty eyes of 20 healthy subjects were included in this study. The dynamics of the ocular components, such as the cornea, the crystalline lens, and the retina, was measured by ...
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    9. Spatiotemporal optical coherence (STOC) manipulation suppresses coherent cross-talk in full-field swept-source optical coherence tomography

      Spatiotemporal optical coherence (STOC) manipulation suppresses coherent cross-talk in full-field swept-source optical coherence tomography
      Full-field swept-source optical coherence tomography (FF-SS-OCT) provides high-resolution depth-resolved images of the sample by parallel Fourier-domain interferometric detection. Although FF-SS-OCT implements high-speed volumetric imaging, it suffers from the cross-talk-generated noise from spatially coherent lasers. This noise reduces the transversal image resolution, which in turn, limits the wide adaptation of FF-SS-OCT for practical and clinical applications. Here, we introduce the novel spatiotemporal optical coherence (STOC) manipulation. In STOC the time-varying inhomogeneous ...
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    10. Non invasive optical cellular imaging in humans

      Non invasive optical cellular imaging in humans
      One of the most appealing and still unsolved problems in biological and medical imaging is the possibility of noninvasive visualization of tissue in vivo with an accuracy of microscopic examination. A major difficulty to solve in biomedical imaging is a degradation of image quality caused by the presence of optical inhomogeneity of tissue. Is there any chance to develop a microscopic method that allows non-invasive observation of cells in living ...
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    11. Enhancing microvasculature maps for Optical Coherence Tomography - Angiography (OCT-A)

      Enhancing microvasculature maps for Optical Coherence Tomography - Angiography (OCT-A)
      OCT-A is becoming more popular in recent years and there is a high demand to improve the quality of angiograms as well as to extract quantitative information. We applied various processing methods for microvasculature enhancement like Hessian-Frangi to a data set obtained with Bessel and Gaussian OCT systems. We used angiogenesis, fractal and multifractal analysis to extract more quantitative information. We applied the processing methods for healthy, stroke, tumor progression ...
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    12. Assessment of the influence of viscoelasticity of cornea in animal ex vivo model using air‐puff optical coherence tomography and corneal hysteresis

      Assessment of the influence of viscoelasticity of cornea in animal ex vivo model using air‐puff optical coherence tomography and corneal hysteresis
      Application of the air‐puff swept source OCT (SS‐OCT) instrument to determine the influence of viscoelasticity on the relation between overall the air‐puff force and corneal apex displacement of porcine corneas ex vivo is demonstrated. Simultaneous recording of time‐evolution of the tissue displacement and air pulse stimulus allows obtaining valuable information related in part to the mechanical properties of the cornea. A novel approach based on quantitative ...
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    13. Feature Of The Week 10/08/2017: Optical Coherence Microscopy as a Novel, Non-Invasive Method for the 4D Live Imaging of Early Mammalian Embryos

      Feature Of The Week 10/08/2017: Optical Coherence Microscopy as a Novel, Non-Invasive Method for the 4D Live Imaging of Early Mammalian Embryos
      Imaging of living cells based on traditional fluorescence and confocal laser scanning microscopy has delivered an enormous amount of information critical for understanding biological processes in single cells. However, the requirement for a high numerical aperture and fluorescent markers still limits researchers ability to visualize the cellular architecture without causing short- and long-term photodamage. Optical coherence microscopy (OCM) is a promising alternative that circumvents the technical limitations of fluorescence imaging ...
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    14. Classification of biological micro-objects using optical coherence tomography

      Classification of biological micro-objects using optical coherence tomography
      We report on the development of a technique for differentiating between biological micro-objects using a rigorous, full-wave model of OCT image formation. We model an existing experimental prototype which uses OCT to interrogate a microfluidic chip containing the blood cells. A full-wave model is required since the technique uses light back-scattered by a scattering substrate, rather than by the cells directly. The light back-scattered by the substrate is perturbed upon ...
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    15. Optical coherence microscopy as a novel, non-invasive method for the 4D live imaging of early mammalian embryos

      Optical coherence microscopy as a novel, non-invasive method for the 4D live imaging of early mammalian embryos
      Imaging of living cells based on traditional fluorescence and confocal laser scanning microscopy has delivered an enormous amount of information critical for understanding biological processes in single cells. However, the requirement for a high numerical aperture and fluorescent markers still limits researchers ability to visualize the cellular architecture without causing short- and long-term photodamage. Optical coherence microscopy (OCM) is a promising alternative that circumvents the technical limitations of fluorescence imaging ...
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    16. Twenty-five years of optical coherence tomography: the paradigm shift in sensitivity and speed provided by Fourier domain OCT

      Twenty-five years of optical coherence tomography: the paradigm shift in sensitivity and speed provided by Fourier domain OCT
      Optical coherence tomography (OCT) has become one of the most successful optical technologies implemented in medicine and clinical practice mostly due to the possibility of non-invasive and non-contact imaging by detecting back-scattered light. OCT has gone through a tremendous development over the past 25 years. From its initial inception in 1991 [Science 254 , 1178 (1991)] it has become an indispensable medical imaging technology in ophthalmology. Also in fields like cardiology ...
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    17. 1-15 of 119 1 2 3 4 5 6 7 8 »
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  2. About Maciej Wojtkowski

    Maciej Wojtkowski

    Maciej Wojtkowski is a renowned scientist active in the field of biomedical imaging. His research interests include optical coherence imaging and microscopy applied to biomedical imaging. He has a pioneering contribution to design and development of ultra-high speed Optical Coherence Tomography (OCT), which is commonly used in ophthalmic and cardiologic diagnosis. Multiple OCT prototypes developed by Prof. Wojtkowski served as the basis for many instruments in ophthalmology clinics across the World.

  3. Quotes

    1. For our group at NCU it was more about having an industrial partner, which in the long term could give job opportunities for MSc and PhD students and PhDs from our group one of the conditions of our collaboration was creation by Optopol a R&D office at NCU.
      In Optical Coherence Tomography Used $500M of Federally Funded Research Over The Past Decade: How was it Used, What was Accomplished, and What’s to Come?