1. Articles in category: Probes

    241-264 of 357 « 1 2 ... 8 9 10 11 12 13 14 15 »
    1. Pixelation effect removal from fiber bundle probe based optical coherence tomography imaging

      Pixelation effect removal from fiber bundle probe based optical coherence tomography imaging
      A method of eliminating pixelization effect from en face optical coherence tomography (OCT) image when a fiber bundle is used as an OCT imaging probe is presented. We have demonstrated that applying a histogram equalization process before performing a weighted-averaged Gaussian smoothing filter to the original lower gray level intensity based image not only removes the structural artifact of the bundle but also enhances the image quality with minimum blurring of object’s image features. The measured contrast-to-noise ratio (CNR) for an image of the US Air Force test target was 14.7dB (4.9dB), after (before) image processing. In ...
      Read Full Article
    2. System and method for positioning a probe

      System and method for positioning a probe
      An adapter couples a length of optical fiber to a hollow probe and to an optical coherence tomography instrument. The length of optical fiber may be greater than the length of the adapter itself. The optical fiber is fixed to an optical coupler at a proximal end of the adapter and may be maintained in a curved configuration by features located in an internal cavity of the adapter. An optical fiber advance mechanism be used to advance and/or retract the length of optical fiber to align it within the hollow probe.
      Read Full Article
    3. Arterial probe for OCT

      Arterial probe for OCT
      An apparatus and associated method for detecting vulnerable plaque within a lumen defined by an intraluminal wall is described. The apparatus includes a probe having a distal portion and a proximal portion. The apparatus includes an optical waveguide extending along the probe. The optical waveguide is configured to carry optical radiation between the distal and proximal portions, and has a distal end in communication with the intraluminal wall. The apparatus includes an interferometer coupled to the optical waveguide and configured to provide an interference signal for sub-surface imaging of the intraluminal wall, and a processing module configured to provide spectroscopic ...
      Read Full Article
    4. Progress toward inexpensive endoscopic high-resolution common-path OCT

      Progress toward inexpensive endoscopic high-resolution common-path OCT
      Presented in this work is our effort to develop a simple, inexpensive high resolution fiber-optic Optical Coherence Tomography. The approach is based on common-path Fourier Domain OCT (CP-FDOCT), which can lead to applications for both microsurgical tool control and high-resolution endoscopic imaging. The system utilizes a combination of standard fiber optic components and novel signal processing techniques in order to achieve high axial resolution and to simplify the system. High axial resolution is achieved by implementing the Enhanced Lee filter to reduce speckle noise in the OCT image and Richardson-Lucy deconvolution algorithm afterwards to suppress sidelobes induced by the system ...
      Read Full Article
    5. Integrated intravascular optical coherence tomography (OCT) - ultrasound (US) imaging system

      Integrated intravascular optical coherence tomography (OCT) - ultrasound (US) imaging system
      Optical coherence tomography (OCT) and intravascular ultrasound (IVUS) are considered two complementary imaging techniques in the detection and diagnosis of atherosclerosis. OCT permits visualization of micron-scale features of atherosclerosis plaque, and IVUS offers full imaging depth of vessel wall. Under the guidance of IVUS, minimal amount of flushing agent will be needed to obtain OCT imaging of the interested area. We report on a dual-modality optical coherence tomography (OCT) - ultrasound (US) system for intravascular imaging. To the best of our knowledge, we have developed the first integrated OCT-US probe that combines OCT optical components with an ultrasound transducer. The OCT ...
      Read Full Article
    6. Perspectives of optical scanning in OCT

      Perspectives of optical scanning in OCT
      We present an overview of our contributions and directions of research in the domain of optical scanners, with regard to their perspectives of use in optical coherence tomography (OCT). The performances, advantages and drawbacks of the different types of scanning systems are summarized. Both 1-D and 2-D scanners for various applications in OCT, from swept source filters to flying the beam over the target are considered. We briefly present our developments of polygon mirror (PM) scanners. We study galvoscanners (GS) in order to increase their duty cycle in general and for high speed scanners in particular. The limitations in reaching ...
      Read Full Article
    7. The OCT penlight: in-situ image guidance for microsurgery

      The OCT penlight: in-situ image guidance for microsurgery
      , , et al. We have developed a new image-based guidance system for microsurgery using optical coherence tomography (OCT), which presents a virtual image in its correct location inside the scanned tissue. Applications include surgery of the cornea, skin, and other surfaces below which shallow targets may advant ... [Proc. SPIE 7625, 762502 (2010)] published Tue Feb 23, 2010.
      Read Full Article
    8. Optical micro-endoscopes for 3D in-vivo imaging

      Optical micro-endoscopes for 3D in-vivo imaging
      Electrothermal micromirrors and a flexible printed circuit board permit fast, small optical coherence tomography of internal organs. Optical coherence tomography (OCT) is a medical optical imaging technique that can achieve high-resolution 3D images (1-15μm)1 by detecting infrared light scattered by body tissue. It has an imaging depth range of about 3mm in highly-scattered tissue and has already been widely used for external imaging, e.g., for eye diseases and skin cancer diagnosis. It would be useful to apply OCT to internal imaging, since about 85% of all cancers originate from the surface layers of internal organs. As these layers ...
      Read Full Article
    9. Integrated intravascular optical coherence tomography ultrasound imaging system

      Integrated intravascular optical coherence tomography ultrasound imaging system
      We report on a dual-modality optical coherence tomography (OCT) ultrasound (US) system for intravascular imaging. To the best of our knowledge, we have developed the first integrated OCT-US probe that combines OCT optical components with an US transducer. The OCT optical components mainly consist of a single-mode fiber, a gradient index lens for light-beam focusing, and a right-angled prism for reflecting light into biological tissue. A 40-MHz piezoelectric transducer (PZT-5H) side-viewing US transducer was fabricated to obtain the US image. These components were integrated into a single probe, enabling both OCT and US imaging at the same time. In vitro ...
      Read Full Article
    10. High speed optical coherence microscopy with autofocus adjustment and a miniaturized endoscopic imaging probe

      High speed optical coherence microscopy with autofocus adjustment and a miniaturized endoscopic imaging probe
      ical coherence microscopy (OCM) is a promising technique for high resolution cellular imaging in human tissues. An OCM system for high-speed en face cellular resolution imaging was developed at 1060 nm wavelength at frame rates up to 5 Hz with resolutions of < 4 µm axial and < 2 µm transverse. The system utilized a novel polarization compensation method to combat wavelength dependent source polarization and achieve broadband electro-optic phase modulation compatible with ultrahigh axial resolution. In addition, the system incorporated an auto-focusing feature that enables precise, near real-time alignment of the confocal and coherence gates in tissue, allowing user-friendly optimization of ...
      Read Full Article
    11. In vivo 3D and Doppler OCT imaging using electrothermal MEMS scanning mirrors

      In vivo 3D and Doppler OCT imaging using electrothermal MEMS scanning mirrors
      Most cancers occur inside human body, so endoscopic high-resolution imaging modalities are required for early cancer detection and surgical removal. This paper reports in vivo endoscopic 3D imaging based on optical coherence tomography (OCT). Endoscopic imaging is enabled by integrating rapid-scanning MEMS mirror into a miniature imaging probe. The MEMS mirror has an aperture size of 1 mm by 1 mm and a chip size of 2 mm by 2 mm. The optical scan angle exceeds ±25 V at 6 Vdc, and thus large, constant-velocity, linear scan can be realized. The outer diameter of the probe is only 5 mm ...
      Read Full Article
    12. Investigation of gold-coated bare fiber probe for in situ intra-vitreous coherence domain optical imaging and sensing

      Investigation of gold-coated bare fiber probe for in situ intra-vitreous coherence domain optical imaging and sensing
      Abstract  We have investigated the usage of gold-plated bare fiber probes for in situ imaging of retinal layers and surrounding ocular tissues using time-domain common-path optical coherence tomography. The fabricated intra-vitreous gold-plated micro-fiber probe can be fully integrated with surgical tools working in close proximity to the tissue to provide subsurface images having a self-contained reference plane independent to the Fresnel reflection between the distal end of the probe and the following medium for achieving reference in typical common-path optical coherence tomography. We have fully characterized the probe in an aqueous medium equivalent to the vitreous humor in the eye ...
      Read Full Article
    13. Miniature actuator mechanism for intravascular imaging

      Miniature actuator mechanism for intravascular imaging
      The present invention relates to a new intravascular imaging device based on a Shape Memory Alloy (SMA) actuator mechanism embedded inside an elongate member such as a guide wire or catheter. The present invention utilizes a novel SMA mechanism to provide side-looking imaging by providing movement for an ultrasound transducer element. This novel SMA actuator mechanism can be easily fabricated in micro-scale, providing an advantage over existing imaging devices because it offers the ability to miniaturize the overall size of the device, while the use of multiple transducer crystals maximizes field of view. Also disclosed are methods of using the ...
      Read Full Article
    14. Quantification of glycerol diffusion in human normal and cancer breast tissues in vitro with optical coherence tomography

      Quantification of glycerol diffusion in human normal and cancer breast tissues in vitro with optical coherence tomography
      Optical coherence tomography (OCT) holds great promise as a routine research tool for analysis of identifying the boundaries between normal and diseased breast tissue in vitro and in vivo. However, despite the depth penetration afforded by this imaging modality, light attenuation in tissues imposes limitations. Here we studied the optical clearing effect of glycerol in human cancer and normal breast tissues with OCT for functional imaging to monitor. Depth- and time-resolved profiles for OCT signal enhancement were presented. The results show that the OCT imaging depth and imaging contrast of breast tissues have been improved after application of 60% glycerol ...
      Read Full Article
    15. Feature Of The Week 2/7/10: Manual-Scanning Optical Coherence Tomography (OCT) Probe Based on Position Tracking

      Feature Of The Week 2/7/10: Manual-Scanning Optical Coherence Tomography (OCT) Probe Based on Position Tracking
      Feature Of The Week 2/7/10: Optical Coherence Tomography (OCT) is now an important modality in the field of biomedical imaging for its high resolution and non-invasive nature. People have been developing OCT endoscopes to penetrate into deep biological tissues and extend the limited light penetration depth in near infrared wavelength region. Different ways of steering the probing beam have been developed over the years. As most of them need some form of mechanical actuation, they usually come with the associated cost of additional hardware that must be integrated onto the probes. An OCT probe that can be manually ...
      Read Full Article
    16. Ablation And Monitoring System Including A Fiber Optic Imaging Catheter And An Optical Coherence Tomography System (Wo 2010/011820)

      An ablation and monitoring system comprises a catheter, an optical coherence tomography (OCT) system, and an ablation generator. The catheter comprises one or more optical fibers to transmit a light beam to a tissue material and collect a reflected light from the tissue material. The OCT system is in optical communication with the catheter via the one or more optical fibers, providing the light beam to the one or more optical fibers and receiving the reflected light from the one or more optical fibers. The ablation generator is in electrical communication with the OCT system and with the catheter. The ...
      Read Full Article
    17. High-resolution OCT explores the gut

      High-resolution OCT explores the gut
      Fourier domain detection has greatly improved the speed and resolution of optical coherence tomography (OCT), opening up the possibility of in vivo clinical imaging. A team of Toronto-based researchers has now shown how this technology could be applied inside the gastrointestinal tract, a technique that could replace invasive biopsies when looking for early signs of cancer (Phys. Med. Biol. 55 615). The miniaturized OCT imager is the result of collaboration between the University of Toronto (Toronto, CA), Princess Margaret Hospital (Toronto, CA) and Michelson Diagnostics in the UK. The core technology is a multi-beam Fourier domain OCT system that uses ...
      Read Full Article
    18. Common-path optical coherence tomography guided fibre probe for spatially precise optical nerve stimulation

      Common-path optical coherence tomography guided fibre probe for spatially precise optical nerve stimulation
      A simple and effective common-path optical coherence tomography guided fibre probe for optical nerve stimulation has been developed and tested. The probe is capable of real-time monitoring of the fibre-to-nerve distance up to more than 1 mm at an axial resolution of approximately 3 μm, thus improving the precision and safety of stimulation laser power delivery.
      Read Full Article
    19. Touching a nerve

      Touching a nerve
      A new method to guide and control microsurgical tools using optical coherence tomography (OCT) is being developed by researchers at Johns Hopkins University and the US Food and Drug Administration Center for Devices and Radiological Health. In their recent work, which appears in this issue of Electronics Letters, the team have demonstrated a fi bre nerve stimulation probe integrated with an OCT distance sensor which can be controlled much more precisely; therefore signifi cantly improving the safety of the technique.
      Read Full Article
    20. Doppler optical coherence tomography for interventional cardiovascular guidance: in vivo feasibility and forward-viewing probe flow phantom demonstration

      Doppler optical coherence tomography for interventional cardiovascular guidance: in vivo feasibility and forward-viewing probe flow phantom demonstration
      We demonstrate the potential of a forward-looking Doppler optical coherence tomography (OCT) probe for color flow imaging in several commonly seen narrowed artery morphologies. As a proof of concept, we present imaging results of a surgically exposed thrombotic occlusion model that was imaged superficially to demonstrate that Doppler OCT can identify flow within the recanalization channels of a blocked artery. We present Doppler OCT images in which the flow is nearly antiparallel to the imaging direction. These images are acquired using a flexible 2.2-mm-diam catheter that used electrostatic actuation to scan up to 30 deg ahead of the distal ...
      Read Full Article
    21. Quantitative Methods For Obtaining Tissue Characteristics From Optical Coherence Tomography Images (Wo 2009/149131)

      Quantitative Methods For Obtaining Tissue Characteristics From Optical Coherence Tomography Images (Wo 2009/149131)
      A method and apparatus for determining properties of a tissue or tissues imaged by optical coherence tomography (OCT). In one embodiment the backscatter and attenuation of the OCT optical beam is measured and based on these measurements and indicium such as color is assigned for each portion of the image corresponding to the specific value of the backscatter and attenuation for that portion. The image is then displayed with the indicia and a user can then determine the tissue characteristics. In an alternative embodiment the tissue characteristics is classified automatically by a program given the combination of backscatter and attenuation ...
      Read Full Article
    241-264 of 357 « 1 2 ... 8 9 10 11 12 13 14 15 »
  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, Velocimetry
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Popular Articles

  3. Organizations in the News

    1. (1 articles) Sunnybrook Health Sciences Centre
    2. (1 articles) Vanderbilt University
    3. (1 articles) Ryerson University
    4. (1 articles) Seoul National University
    5. (1 articles) University of Toronto
  4. People in the News

    1. (1 articles) Victor X. D. Yang
    2. (1 articles) Stephen Lam
  5. OCT Companies in the News

    1. (1 articles) Bioptigen