1. Articles from Danuta Bukowska

    1-11 of 11
    1. Imaging of the stroke-related changes in the vascular system of the mouse brain with the use of extended focus Optical Coherence Microscopy

      Imaging of the stroke-related changes in the vascular system of the mouse brain with the use of extended focus Optical Coherence Microscopy

      We used Optical Coherence Microscopy (OCM) to monitor structural and functional changes due to ischemic stroke in small animals brains in vivo. To obtain lateral resolution of 2.2 μm over the range of 600 μm we used extended focus configuration of OCM instrument involving Bessel beam. It provided access to detailed 3D information about the changes in brain vascular system up to the level of capillaries across I and II/III layers of neocortex. We used photothrombotic stroke model involving photoactive application of rose bengal to assure minimal invasiveness of the procedure and precise localization of the clot distribution ...

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    2. Differentiation of morphotic elements in human blood using optical coherence tomography and a microfluidic setup

      Differentiation of morphotic elements in human blood using optical coherence tomography and a microfluidic setup

      We demonstrate a novel optical method for the detection and differentiation between erythrocytes and leukocytes that uses amplitude and phase information provided by optical coherence tomography (OCT). Biological cells can introduce significant phase modulation with substantial scattering anisotropy and dominant forward-scattered light. Such physical properties may favor the use of a trans-illumination imaging technique. However, an epi-illumination mode may be more practical and robust in many applications. This study describes a new way of measuring the phase modulation introduced by flowing microobjects. The novel part of this invention is that it uses the backscattered signal from the substrate located below ...

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    3. Feature Of The Week 11/25/12: Nicolaus Copernicus University Presents Work on Four-Dimensional OCT Imaging Using Graphics Processing Units

      Feature Of The Week 11/25/12: Nicolaus Copernicus University Presents Work on Four-Dimensional OCT Imaging Using Graphics Processing Units

      Nicolaus Copernicus University present the application of graphics processing unit (GPU) programming for real-time three-dimensional (3-D) Fourier domain optical coherence tomography (FdOCT) imaging with implementation of flow visualization algorithms. One of the limitations of FdOCT is data processing time, which is generally longer than data acquisition time. Utilizing additional algorithms, such as Doppler analysis, further increases computation time. The general purpose computing on GPU (GPGPU) has been used successfully for structural OCT imaging, but real-time 3-D imaging of flows has so far not been presented. NCU has developed software for structural and Doppler OCT processing capable of visualization of two-dimensional ...

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    4. Four-dimensional structural and Doppler optical coherence tomography imaging on graphics processing units

      Four-dimensional structural and Doppler optical coherence tomography imaging on graphics processing units

      The authors present the application of graphics processing unit (GPU) programming for real-time three-dimensional (3-D) Fourier domain optical coherence tomography (FdOCT) imaging with implementation of flow visualization algorithms. One of the limitations of FdOCT is data processing time, which is generally longer than data acquisition time. Utilizing additional algorithms, such as Doppler analysis, further increases computation time. The general purpose computing on GPU (GPGPU) has been used successfully for structural OCT imaging, but real-time 3-D imaging of flows has so far not been presented. We have developed software for structural and Doppler OCT processing capable of visualization of two-dimensional (2-D ...

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    5. Multi-parametric imaging of murine brain using spectral and time domain optical coherence tomography

      Multi-parametric imaging of murine brain using spectral and time domain optical coherence tomography

      Examination of brain functions in small animal models may help improve the diagnosis and treatment of neurological conditions. Transcranial imaging of small rodents’ brains poses a major challenge for optical microscopy. Another challenge is to reduce the measurement time. We describe methods and algorithms for three-dimensional assessment of blood flow in the brains of small animals, through the intact skull, using spectral and time domain optical coherence tomography. By introducing a resonant scanner to the optical setup of the optical coherence tomography (OCT) system, we have developed and applied a high-speed spectral OCT technique that allows us to vary the ...

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    6. Microfluidics analysis of blood using joint spectral and time domain optical coherence tomography

      Microfluidics analysis of blood using joint spectral and time domain optical coherence tomography

      Although the Doppler Optical Coherence Tomography techniques have already enabled imaging of blood flow in large vessels in biological tissues, the generation of velocity maps of the capillary network is still a challenge. Since several important physiological and pathological phenomena occur in the microcirculation, the possibility of flow imaging and velocity assessment in microcapillaries may be important for medical diagnostics. Understanding of the origin of the Doppler signal in capillary vessels and limitations of such measurements is essential for further development of Doppler OCT methods. In the OCT flow maps of a microcapillary network randomly varying Doppler signals are observed ...

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    7. Angiogram visualization and total velocity blood flow assessment based on intensity information analysis of OCT data

      Angiogram visualization and total velocity blood flow assessment based on intensity information analysis of OCT data

      We propose two independent OCT data processing methods allowing visualization and analysis of the blood flow. These methods utilize variations in the OCT intensity images caused by flowing blood. The first method calculates standard deviation of intensity to generate retinal OCT angiograms. We present algorithm of this method and results of application for visualization of the microvasculature in the macular area of the human eye in vivo. The second method calculates cross power spectra of the volumetric intensity images to assess blood flow velocity in three dimensions. Validation of this method for OCT imaging was performed in a flow phantom.

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    8. True velocity mapping using joint spectral and time domain optical coherence tomography

      True velocity mapping using joint spectral and time domain optical coherence tomography
      We present both axial and transverse components estimation using joint Spectral and Time domain Optical Coherence Tomography (STdOCT) method. Whereas axial component of velocity vector can be determined from the time-dependent Doppler beating frequency, the transverse component can be assessed by the analysis of the broadening of flow velocity profiles (Doppler bandwidth). This enables us to quantitatively determine the absolute value of the velocity vector. The accurate analyses are performed using well-defined flow of Intralipid solution in the glass capillary. This enables performing in vivo imaging and allows to calculate velocity maps of the retinal vasculature
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    9. Simultaneous analysis of flow velocity and spectroscopic properties of scattering media with the use of joint Spectral and Time domain OCT

      In this paper we describe how to simultaneously retrieve spectroscopic and flow velocity information of scattering media such as biological tissues with the use of Optical Coherence Tomography (OCT). The main problem which must be overcome during spectral information recovery is random speckle noise. It cannot be effectively removed if the medium is stationary. However, if during the measurement time there is a continuous change of locations of scattering particles causing the phase change, an efficient averaging of speckle-affected spectra takes place. In order to implement this idea we propose to make use of the measurement protocol of joined Spectral ...
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    10. Comparison of reflectivity maps and outer retinal topography in retinal disease by 3-D Fourier domain optical coherence tomography

      Comparison of reflectivity maps and outer retinal topography in retinal disease by 3-D Fourier domain optical coherence tomography
      We demonstrate and compare two image processing methods for visualization and analysis of three-dimensional optical coherence tomography (OCT) data acquired in eyes with different retinal pathologies. A method of retinal layer segmentation based on a multiple intensity thresholding algorithm was ... [Opt. Express 17, 4189-4207 (2009)]
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    11. Three-dimensional retinal blood flow analysis using joint spectral and time domain optical coherence tomography

      In this submission we demonstrate a new application of the joint Spectral and Time domain Optical Coherence Tomography (STdOCT) technique for segmenting and measuring the retinal blood flow velocity in three dimensions. The method is based on direct detection of Doppler shift that arises in time dur ... [Proc. SPIE 7163, 71630Q (2009)] published Wed Feb 18, 2009.
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    1-11 of 11
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  2. Topics in the News

    1. (11 articles) Nicolaus Copernicus University
    2. (11 articles) Maciej Wojtkowski
    3. (10 articles) Maciej Szkulmowski
    4. (7 articles) Iwona Gorczynska
    5. (5 articles) Daniel Szlag
    6. (5 articles) Andrzej A. Kowalczyk
    7. (3 articles) Anna Szkulmowska
    8. (2 articles) Marcin Sylwestrzak
    9. (2 articles) Ireneusz Grulkowski
    10. (2 articles) Piotr Targowski
    11. (1 articles) Medical University of Vienna
    12. (1 articles) Harvard University
    13. (1 articles) NYU Langone Medical Center
    14. (1 articles) Massachusetts General Hospital
    15. (1 articles) Tianjin University
    16. (1 articles) University of Hong Kong
    17. (1 articles) Semmelweis University
    18. (1 articles) Guillermo J. Tearney
    19. (1 articles) Arnaud Dubois
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    Comparison of reflectivity maps and outer retinal topography in retinal disease by 3-D Fourier domain optical coherence tomography True velocity mapping using joint spectral and time domain optical coherence tomography Microfluidics analysis of blood using joint spectral and time domain optical coherence tomography Angiogram visualization and total velocity blood flow assessment based on intensity information analysis of OCT data Multi-parametric imaging of murine brain using spectral and time domain optical coherence tomography Four-dimensional structural and Doppler optical coherence tomography imaging on graphics processing units Feature Of The Week 11/25/12: Nicolaus Copernicus University Presents Work on Four-Dimensional OCT Imaging Using Graphics Processing Units Imaging of the stroke-related changes in the vascular system of the mouse brain with the use of extended focus Optical Coherence Microscopy Selective retinex enhancement based on the clustering algorithm and block-matching 3D for optical coherence tomography images Artificial intelligence, the internet of things, and virtual clinics: ophthalmology at the digital translation forefront Detecting glaucoma based on spectral domain optical coherence tomography imaging of peripapillary retinal nerve fiber layer: a comparison study between hand-crafted features and deep learning model 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