1. 1-18 of 18
    1. 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 tissue? Classical optical microscopy requires first to retrieve, then to process and finally to stain the sample, which is usually not possible to be performed in vivo. One of the ...

      Read Full Article
    2. 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 and the results of enhanced processing and quantitative analysis for those are presented in this letter.

      Read Full Article
    3. One-dimensional, portable optical coherence tomography system

      One-dimensional, portable optical coherence tomography system

      Imaging methods are an expanding branch of technology, which involves data acquisition and analysis of images for research and diagnostics. This paper has been devoted to describe the optical design for one-dimensional, portable optical coherence tomography (OCT) system. The Mach-Zehnder interferometer has been designed in the presented study. Description of the construction and applied hardware solutions have been written. Moreover, a dedicated software tools for signal processing and data acquisition have been developed

      Read Full Article
    4. Polarization-sensitive optical coherence tomography for ceramic materials inspection

      Polarization-sensitive optical coherence tomography for ceramic materials inspection

      Ceramics production is looking for a fast, reliable and non-destructive method that can be implemented on site for defect detection and analysis. In this paper we present polarization-sensitive optical coherence tomography (PS-OCT) as a method for defect inspection. Proposed extensions to standard OCT provide additional information for complete characterization of tested object. We compare OCT and microscope imaging that can easily detect enamel layer defects. The object under test is a sample ceramic plate with several defects occurring in production process. Results of OCT imaging show those defects are only in enamel layer without any effect on potsherd layer.

      Read Full Article
    5. Simultaneous shape measurement and layers detection by means of low coherence interferometry and optical coherence tomography

      Simultaneous shape measurement and layers detection by means of low coherence interferometry and optical coherence tomography

      In this paper authors show the application of low coherence interferometry and optical coherence tomography with non-Gaussian light source, which are applicable in simultaneous measurement of micromembrane and detection of layers deposited on silicon wafer. The exemplary measurement results obtained with laboratory setup are presented.

      Read Full Article
    6. Breast phantom for comparison X-ray and polarimetric optical tomography imaging

      Breast phantom for comparison X-ray and polarimetric optical tomography imaging

      Breast phantom made as combination of paraffin and INTRALIPIDTM was tested by use of conventional X-ray computed tomography and polarimetric optical tomography. The INTRALIPIDTM is a liquid commonly used for simulation breast tissues optical properties but it is useless as X-ray phantom. During our tests we have observed that X-ray tomography allows to reconstruct correctly the positions of INTRALIPIDTM inclusions inside paraffin medium but we cannot distinguish different densities of INTRALIPIDTM in each inclusion. On the other hand the polarimetric optical tomography allows to distinguish densities of INTRALIPIDTM (0%, 10%, 20%) in inclusions but with relatively low accuracy of their ...

      Read Full Article
    7. Comparison of polarization and polarimetric optical tomography methods for recognition of tissue simulators inside breast phantom

      Comparison of polarization and polarimetric optical tomography methods for recognition of tissue simulators inside breast phantom
      In the paper we present results of recognition of tissues simulators inside breast phantom based on polarization analysis of scattered light as well as polarimetric optical tomography method based on Mueller Stokes formalism. Blood, fat and muscle tissues were simulated by 10mm diameter probes with red dye, 20% Intralipid™ and water with polarizing foil respectively. All tissue simulators were placed inside container (diameter 120mm) filled by 0.1% solution of Intralipid™. Different kind of polarization state of laser beam (670nm, 35 mW) was used for lighting the container (breast phantom). Results of measurement show that polarization optical tomography easier allows ...
      Read Full Article
    8. Performance of 97-elements ALPAO membrane magnetic deformable mirror in Adaptive Optics - Optical Coherence Tomography system for in vivo imaging of human retina

      Performance of 97-elements ALPAO membrane magnetic deformable mirror in Adaptive Optics - Optical Coherence Tomography system for in vivo imaging of human retina
      We present an evaluation of two different configurations of the ALPAO 97-actuator membrane magnetic deformable mirror for wavefront correction, using either 7 or 9 actuators across the eye pupil. These tests included monitoring of aberration correction for a human subject. This AO-sub system is part of the UC Davis high-resolution human retinal imaging adaptive optics - optical coherence tomography (AO-OCT) instrument. AO-OCT allows the three-dimensional (3D) visualization of different retinal structures in vivo with high volumetric resolution (3x3x3µm3). Full Text: PDF References: [1] R.J. Zawadzki, S. Jones, S. Olivier, M. Zhao, B. Bower, J. Izatt, S. Choi, S. Laut, and ...
      Read Full Article
    9. Optical frequency domain imaging system and catheters for volumetric imaging of the human esophagus

      Optical frequency domain imaging system and catheters for volumetric imaging of the human esophagus

      Barrett's esophagus (BE) is a metaplastic disorder that can undergo dysplastic progression, leading to esophageal adenocarcinoma. Upper endoscopy is the standard of care for screening for BE, but this technique has a relatively low diagnostic accuracy and high cost due to the requirement of conscious sedation. Optical frequency domain imaging (OFDI) is a high-speed imaging modality that generates cross-sectional images of tissues with a resolution of approximately 10µm that is sufficient for detecting microscopic tissue architecture. In combination with a balloon-centering catheter, this method enables BE diagnosis over the entire distal esophagus.   Full Text: PDFReferences S. H. Yun ...

      Read Full Article
    10. Analysis of ocular hemodynamic using combined STdOCT and ultrasonic methods

      Analysis of ocular hemodynamic using combined STdOCT and ultrasonic methods
      Optical coherence microscopy (OCM) is relatively new, noninvasive method of biomedical imaging. It uses Michelson interferometer to locate successive layers in tissue and enables reconstructing cross-sectional images that can be useful for medical diagnosis. In this work, we propose to develop new light sources for OCM to increase the resolution of images by introducing blue light. To achieve this goal, we decided to test a method known as achromatic second harmonic generation in our own, new configuration. Full Text: PDF References: A.M. Zysk et al., "Optical coherence tomography: a review of clinical development from bench to bedside", J Biomed ...
      Read Full Article
    11. Broadband blue light for Optical Coherence Microscopy

      Broadband blue light for Optical Coherence Microscopy
      Optical coherence microscopy (OCM) is relatively new, noninvasive method of biomedical imaging. It uses Michelson interferometer to locate successive layers in tissue and enables reconstructing cross-sectional images that can be useful for medical diagnosis. In this work, we propose to develop new light sources for OCM to increase the resolution of images by introducing blue light. To achieve this goal, we decided to test a method known as achromatic second harmonic generation in our own, new configuration. Full Text: PDF References: A.M. Zysk et al., "Optical coherence tomography: a review of clinical development from bench to bedside", J Biomed ...
      Read Full Article
    12. High-resolution phase mapping with parallel Fourier domain optical coherence microscopy for dispersion contrast imaging

      High-resolution phase mapping with parallel Fourier domain optical coherence microscopy for dispersion contrast imaging

      We demonstrate a high-speed parallel line field optical coherence microscopy (OCM) system that exhibits intrinsically high phase stability even with lateral scanning. The presented Fourier domain (FD) OCM system employs a high speed CMOS detector and achieves up to 512 000 equivalent A-scans per second. The microscopy system is shown to resolve the smallest elements of the USAF resolution test target (Group 7, Element 6), indicating the transverse (Y- non-scanning parallel direction)) resolution and resolution in X (scanning) direction less than 2.2 µm. The capability of imaging biological samples is demonstrated on human red blood cells (RBC). The high ...

      Read Full Article
    13. Imaging limbal and scleral vasculature using Swept Source Optical Coherence Tomography

      Imaging limbal and scleral vasculature using Swept Source Optical Coherence Tomography

      We demonstrate application of high-speed swept source optical coherence tomography for vessel visualization in the anterior segment of the human eye. The human corneo-scleral junction and sclera was imaged in vivo. Imaging was performed using a swept source OCT system operating at 1050nm wavelength range and 100kHz A-scan rate. The high imaging speed enables generation of 3D depth-resolved vasculature maps. The vessel visualization method revealed the rich vascular system in the conjunctiva and episclera. Full Text: PDF References: D. Huang et al., "Optical coherence tomography", Science 254, 1178 (1991). [CrossRef] W. Drexler, J. G. Fujimoto (ed.), Optical Coherence Tomography. Technology ...

      Read Full Article
    14. Spectroscopic analysis for polarization sensitive optical coherent tomography

      Spectroscopic analysis for polarization sensitive optical coherent tomography
      Polarization Sensitive Optical Coherent Tomography (PS-OCT) is a novel optical method to examine a broad range of scattering materials. PS-OCT is an extension of OCT systems, which enables cross-sectional visualization of the device inner structure, as well as analysis of the polarization state of light backscattered from particular points inside the tested device. Polarization sensitive analysis is a very useful tool in OCT measurements. However, it brings a number of problems referring to measurement signal processing, birefringence changes of the investigated sample over the spectral width of a broadband light source. In this paper these problems have been discussed and ...
      Read Full Article
    15. Determination of suspension viscosity from the flow velocity profile measured by Doppler Optical Coherence Tomography

      Determination of suspension viscosity from the flow velocity profile measured by Doppler Optical Coherence Tomography
      In this paper we present, for the first time to our knowledge, the experimental results for determining suspension viscosity in a capillary type viscometer from flow velocity profiles measured by Doppler Optical Coherence Tomography. The suspension of 0.3?m polystyrene microspheres in a glycerol-water solution was used as a model fluid. The viscosity of the suspension was controlled by glycerol concentration. The shear rate and the shear stress at the capillary wall were measured at six flow rates. The corresponding viscosities were calculated. The comparison of the measured shear rates with the values calculated according to the flow rate ...
      Read Full Article
    16. Real-time imaging for Spectral Optical Coherence Tomography with massively parallel data processing

      Real-time imaging for Spectral Optical Coherence Tomography with massively parallel data processing
      In this paper the application of massively parallel processing of Spectral Optical Coherence Tomography (SOCT) data with the aid of a low-cost Graphic Processing Unit (GPU) is presented. The reported system may be used for real-time imaging of high resolution 2D tomograms or for presenting volume data. The overall imaging speed is over 100 frames/second for 2D tomograms built of 1024 A-scans and 9 frames/second for 3D volume images containing 100 slices of 100 A-scans. This includes t he acquisition of 2048 pixels from a CCD camera per A-scan, data transfer to the processor, all necessary processing and ...
      Read Full Article
    17. Multilayered structures examination using polarization sensitive optical coherence tomography

      Multilayered structures examination using polarization sensitive optical coherence tomography
      Optical Coherence Tomography (OCT) is an optical method for non-contact and non-destructive examination of inner structure of multi-layered structures. Polarization sensitive OCT (PS-OCT) is also capable of measuring local optical anisotropy changes. The measurement results, obtained using our custom-built PS-OCT setup, for multilayered birefringent structures demonstrate the applicability of the PS-OCT to characterization of multilayered material stacks containing birefringent polymer layers used e.g. in display technology. In this Letter we present some aspects of our research and experiments and discuss usefulness of polarization sensitive analysis in OCT for examination of technical materials.
      Read Full Article
    18. 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 ...
      Read Full Article
    1-18 of 18
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks