1. Articles from Tomasz Bajraszewski

    1-21 of 21
    1. Method and apparatus for imaging of semi-transparent matter

      Method and apparatus for imaging of semi-transparent matter

      The invention relates to a method and apparatus for measuring the spatial and velocity distribution of scattering structures of a sample in semi-transparent matter. The acquired spectral data I(k, t) are transformed in two steps to image data I(z, v). A Doppler shift is imposed on the light to a separate real and mirror images in the v space to suppress the complex ambiguity artifact.

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    2. Image capturing apparatus, image capturing method, and storage medium

      Image capturing apparatus, image capturing method, and storage medium

      An image capturing apparatus includes a dividing unit configured to divide light from a light source into reference light and measurement light; a first dichroic mirror arranged in a measurement optical path for guiding the measurement light to an object to be examined; a second dichroic mirror arranged in a reference optical path for guiding the reference light to a reference object; and a light receiving unit configured to receive interference light between the measurement light passing through the first dichroic mirror and the reference light passing through the second dichroic mirror.

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    3. Spectral optical coherence tomography

      Spectral optical coherence tomography

      The invention relates to an apparatus for generating a scannable optical delay for a beam of light and an apparatus for Fourier domain optical coherence tomography having said apparatus for generating a scannable optical delay in its reference arm (15). The light beam is directed to a pivotably driven mirror (10) from where it is reflected to a fixed mirror (12), and from there back retro reflected along the reference arm (5). Lens optics (9) are provided to ensure accurate optical alignment in several pivot positions of the pivotably driven mirror (10).

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    4. Apparatus for optical frequency domain tomography with adjusting system

      Apparatus for optical frequency domain tomography with adjusting system

      In an apparatus for imaging of objects by applying optical frequency domain tomography and provided with an adjusting system for setting a relative position of photosensitive elements (174) and a spectrum image (273), the adjusting system is an automatically controlled device causing a relative displacement of at least one photosensitive element (174) of the detection device (173) of the spectrum and the spectrum image (273) between each other. The adjusting system comprises at least one actuator (14, 16) acting on the dispersion device (171) and/or the set of optical elements (172) and/or the detection device (173) and movement ...

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    5. Method And Apparatus For Optical Coherence Tomography

      Method And Apparatus For Optical Coherence Tomography
      The invention relates to optical coherence tomography (OCT), more specifically to spectral optical coherence tomography (SOCT). The invention deals with problem of artefacts occurring in certain scan positions due to sharp increases of reflection by the object under investigation. It solves this problem by using an extra intensity sensor located at an output for non-dispersed light of the dispersive element used for spectral analysis, e. g. in the zero order of a diffraction grating, and using the signal of this sensor for the modification of the interferometric data.
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    6. Method And Apparatus For Eye Movement Tracking In Spectral Optical Coherence Tomography. (SD-OCT) (Wo 2010/063416)

      Method And Apparatus For Eye Movement Tracking In Spectral Optical Coherence Tomography. (SD-OCT) (Wo 2010/063416)
      The invention relates to a method and an apparatus for collecting structural data with spectral optical coherence tomography from samples having a point of maximum reflectance. This point of maximum reflectance is used for adjusting the scanned path pattern.
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    7. Apparatus For Optical Coherence Tomography And Non-Interferometric Imaging (Wo 2010/022915)

      Apparatus For Optical Coherence Tomography And Non-Interferometric Imaging (Wo 2010/022915)
      The invention relates to an apparatus for optical coherence tomography and non-interferometric imaging of a sample. Additional splitting optics are used to arrange off the light used for the non-interferometric imaging. Interrupting means are provided for interrupting light in the reference path during measurement with the non-interferometric imaging.
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    8. Spectral Optical Coherence Tomography (SOCT) (Wo 2010/003684)

      Spectral Optical Coherence Tomography (SOCT) (Wo 2010/003684)
      The invention relates to an apparatus for generating a scannable optical delay for a beam of light and an apparatus for Fourier domain optical coherence tomography having said apparatus for generating a scannable optical delay in its reference arm (15). The light beam is directed to a pivotably driven mirror (10) from where it is reflected to a fixed mirror (12), and from there back retro reflected along the reference arm (5). Lens optics (9) are provided to ensure accurate optical alignment in several pivot positions of the pivotably driven mirror (10).
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    9. Method And Apparatus For Spectral Optical Coherence Tomography (Wo 2009/106358)

      Method And Apparatus For Spectral Optical Coherence Tomography (Wo 2009/106358)
      The invention relates to optical coherence tomography (OCT), more specifically to spectral optical coherence tomography (SOCT). The invention deals with the problem of artefacts due to sharp increases of reflection by the object under investigation. It solves this problem by splitting of a part off the returning light for modification of the interferometric data.
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    10. Fuchs’ Endothelial Dystrophy in 830-nm Spectral Domain Optical Coherence Tomography

      This article presents for the first time the potential of 830-nm spectral domain optical coherence tomography (SD-OCT) in the evaluation of Fuchs’ endothelial dystrophy. SD-OCT is an imaging technique that can be used for in vivo cross-sectional corneal visualization. The important features of SD-OCT instruments include improved sensitivity and short acquisition time, which improves the quality of the tomograms compared with conventional time domain OCT. Tomograms of the corneas of three patients in different stages of Fuchs’ endothelial dystrophy are presented. The authors conclude that 830-nm SDOCT provides clinically valuable cross-sectional assessment of pathomorphological changes in Fuchs’ endothelial dystrophy in ...
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    11. Analysis of the Outer Retina Reconstructed by High-resolution, Three-dimensional Spectral Domain Optical Coherence Tomography

      BACKGROUND AND OBJECTIVE A retrospective cross-sectional study was conducted to demonstrate an analysis of an outer retinal layer reconstructed by the three-dimensional and high-speed spectral domain optical coherence tomography (SD-OCT) instrument. PATIENTS AND METHODS New measurement protocols for SD-OCT and methods of analysis and visualization of the individual segmented retinal layer reconstructed by SD-OCT were proposed. Three contour maps representing mutual distances between the basal part of the retinal pigment epithelium, the junction between the inner and outer segments of photoreceptors, and a reference contour representing the shape of a healthy retina were introduced. RESULTS The analysis of the outer ...
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    12. Flow velocity estimation using joint Spectral and Time domain Optical Coherence Tomography

      Flow velocity estimation using joint Spectral and Time domain Optical Coherence Tomography
      Maciej Szkulmowski, Anna Szkulmowska, Tomasz Bajraszewski, Andrzej Kowalczyk, Maciej Wojtkowski We propose a modified method of acquisition and analysis of Spectral Optical Coherence Tomography (SOCT) data to provide information about flow velocities. The idea behind this method is to acquire a set of SOCT spectral fringes dependent on time followed by a numerical analysis using two ... [Opt. Express 16, 6008-6025 (2008)]
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    13. Improved spectral optical coherence tomography using optical frequency comb

      Tomasz Bajraszewski, Maciej Wojtkowski, Maciej Szkulmowski, Anna Szkulmowska, Robert Huber, Andrzej Kowalczyk. We identify and analyze factors influencing sensitivity drop-off in Spectral OCT and propose a system employing an Optical Frequency Comb (OFC) to verify this analysis. Spectral Optical Coherence Tomography using a method based on an optical frequency comb is demonstrated. Since the spectrum ... [Opt. Express 16, 4163-4176 (2008)]
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    14. Simultaneous analysis of extinction and flow velocity with joint spectral and time domain OCT

      Maciej Wojtkowski, Maciej Szkulmowski, Tomasz Bajraszewski et al. In this contribution we propose a new method of acquisition and analysis of Spectral Optical Coherence Tomography data to obtain information about depth dependent extinction in the scattering media. In joint Spectral and Time domain OCT a set of Spectral Optical Coherence Tomography fringes is acqui ... [Proc. SPIE Int. Soc. Opt. Eng. 6847, 68471M (2008)] published Mon Feb 18, 2008.
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    15. Spectral Optical Coherence Tomography in Video-Rate and 3D Imaging of Contact Lens Wear

      Optometry & Vision Science. 84(12):E1104-E1109, December 2007. KALUZNY, BARTLOMIEJ J. MD, PhD; FOJT, WOJCIECH Dipl Ing; SZKULMOWSKA, ANNA MSc; BAJRASZEWSKI, TOMASZ MSc; WOJTKOWSKI, MACIEJ PhD; KOWALCZYK, ANDRZEJ PhD Abstract: Purpose. To present the applicability of spectral optical coherence tomography (SOCT) for video-rate and three-dimensional imaging of a contact lens on the eye surface. Methods. The SOCT prototype instrument constructed at Nicolaus Copernicus University (Torun, Poland) is b
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    16. Retinal blood flow analysis using joint spectral and time domain optical coherence tomography

      Anna Szkulmowska, Maciej Szkulmowski, Tomasz Bajraszewski et al. We propose a new technique of measuring and analysis of OCT signals: joint Spectral and Time domain Optical Coherence Tomography (STdOCT). This technique is based on a multiple spectral interferogram registration in time increments. The analysis of a single spectral interferogram provides an axial s ... [Proc. SPIE Int. Soc. Opt. Eng. 6844, 68440K (2008)] published Mon Feb 11, 2008.
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    17. Mapping of photoreceptor dysfunction using high resolution three-dimensional spectral optical coherence tomography

      B. L. Sikorski, M. Szkulmowski, J. J. Kaluzny et al. The ability to obtain reliable information on functional status of photoreceptor layer is essential for assessing vision impairment in patients with macular diseases. The reconstruction of three-dimensional retinal structure in vivo using Spectral Optical Coherence Tomography (Spectral OCT) became p ... [Proc. SPIE Int. Soc. Opt. Eng. 6844, 68440J (2008)] published Mon Feb 11, 2008.
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    18. Optical Coherence Tomography for Tracking Canvas Deformation

      Optical Coherence Tomography for Tracking Canvas Deformation
      Preliminary results of the application of optical coherence tomography (OCT), in particular in its spectral mode (SOCT), to tracking of deformations in paintings on canvas caused by periodical humidity changes are presented. The setup is able to monitor the position of a chosen point at the surface of a painting with micrometre precision, simultaneously in three dimensions, every 100 seconds. This allows recording of deformations associated with crack formation. For the particular painting model examined, it was shown that the surface moves in-plane towards the corner, and bulges outwards (Z-direction) in response to a rise in humidity. Subsequent to the ...
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    19. Optical Coherence Tomography for Examination of Parchment Degradation

      Optical Coherence Tomography for Examination of Parchment Degradation
      A novel application of Optical Coherence Tomography utilizing infrared light of 830 nm central wavelength for non invasive examination of the structure of parchment, some covered with iron gall ink, is presented. It is shown that both the parchment and the ink applied are sufficiently transparent to light of this wavelength. In the study, Spectral OCT (SOCT) as well as Polarisation Sensitive OCT (PS-OCT) techniques were used to obtain cross-sectional images of samples of parchment based on scattering properties. The second technique was additionally employed to recover the birefringence properties and the optical axis orientations of the sample. It was ...
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    1-21 of 21
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  2. Topics in the News

    1. (21 articles) Tomasz Bajraszewski
    2. (18 articles) Maciej Szkulmowski
    3. (13 articles) Nicolaus Copernicus University
    4. (12 articles) Maciej Wojtkowski
    5. (9 articles) Anna Szkulmowska
    6. (8 articles) Andrzej A. Kowalczyk
    7. (8 articles) Optopol Technology
    8. (5 articles) Piotr Targowski
    9. (4 articles) Bartlomiej J. Kaluzny
    10. (2 articles) Michalina J. Góra
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