1. Articles in category: Probes

    241-264 of 422 « 1 2 ... 8 9 10 11 12 13 14 ... 16 17 18 »
    1. Optical catheter configurations combining raman spectroscopy with optical fiber-based low coherence reflectometry

      Optical catheter configurations combining raman spectroscopy with optical fiber-based low coherence reflectometry
      The present invention provides apparatuses and methods for sample analysis, such as tissue analysis, that integrate high wavenumber (HW) Raman spectroscopy for chemical composition analysis and optical coherence tomography (OCT) to provide depth and morphological information. The invention also provides side-viewing optical probes that are based on a single double clad optical fiber for performing the combined HW Raman spectroscopy and OCT. Intravascular catheter embodiments and related vascular diagnostic methods are also provided.
      Read Full Article
    2. System and method for reconstruction of the human ear canal from optical coherence tomography scans

      System and method for reconstruction of the human ear canal from optical coherence tomography scans
      A method for reconstructing an ear canal from optical coherence tomography (OCT) scan data of an ear comprises extracting frame numbers and line numbers of interference intensities corresponding to one or more markers on an OCT scan guide, receiving reference frame numbers and lines numbers for one or more markers, determining a starting position and direction for the OCT ear scan from the ear scan marker frame and line numbers and the reference marker frame and line numbers, for each scan line, finding a pixel number of a maximum interference intensity value, and determining an offset distance of said pixel ...
      Read Full Article
      Mentions: Siemens
    3. Two-dimensional scanning probe driven by a solenoid-based single actuator for optical coherence tomography

      Two-dimensional scanning probe driven by a solenoid-based single actuator for optical coherence tomography
      We propose the two-dimensional scanning probe operating with a single actuator, which is thought useful as a sample probe for optical coherence tomography (OCT). The probe was designed to use a single-body lensed fiber cantilever loaded with an iron-bead and driven by a single-solenoid actuator. Elliptic spiral trace patterns were achieved using off-axis magnetic fields of the solenoid. A three-dimensional OCT image was obtained for a scanning area of 3.8 mm×3.4 mm at an acquisition speed of 16.7 s/V. Up to 27 Hz B-scan rate, the proposed probe worked well, and 1000 A-scans were made ...
      Read Full Article
    4. Method and system for producing tomographic image by optical tomography with processing of interference light signals

      Method and system for producing tomographic image by optical tomography with processing of interference light signals
      When reflection light, reflected from a measurement target that has been irradiated with measurement light in such a manner to scan the measurement target, and reference light are combined in each wavelength sweep, interference light is detected as interference signals. When a thinning region in which the interference signals obtained by detecting the interference light in each wavelength sweep are thinned so that the interference signals that are used to produce the tomographic image remain is set, thinning is performed on the plurality of interference signals in the thinning region. Light intensity information about the measurement target in the thinning ...
      Read Full Article
    5. Single fiber endoscopic full-field optical coherence tomography (OCT) imaging probe

      Single fiber endoscopic full-field optical coherence tomography (OCT) imaging probe
      A single fiber full-field optical coherence tomography (OCT) imaging probe (300) includes a hollow tube (301), and a single fiber (305) disposed within the tube for transmitting light received from a broadband light source to a beam splitter (350) in the tube optically coupled to the single fiber (305). The beam splitter (350) splits the light into a first and a second optical beam, wherein the first beam is optically coupled to a reference arm including a MEMS reference micromirror (335) which provides axial scanning and the second beam is optically coupled to a sample arm for probing a sample ...
      Read Full Article
    6. Multisensor probe for tissue identification

      Multisensor probe for tissue identification
      A multisensor probe for continuous real-time tissue identification. The multisensor probe includes a tissue penetrating needle, a plurality of sensors useful in characterizing tissue and a position sensor to measure the depth of the needle into the tissue being diagnosed. The sensors include but are not limited to an optical scattering and absorption spectroscopy sensor, an optical coherence domain reflectometry sensor, an electrical impedance sensor, a temperature sensor, a pO.sub.2 sensor, a chemical sensor and other sensors useful in identifying tissue. The sensors may take the form of a plurality of optical fibers extending through said needle. A ...
      Read Full Article
      Mentions: Luiz B. Da Silva
    7. 3D visualization of tissue microstructures using optical coherence tomography needle probes

      3D visualization of tissue microstructures using optical coherence tomography needle probes

      Optical coherence tomography (OCT) needle probes use miniaturized focusing optics encased in a hypodermic needle. Needle probes can scan areas of the body that are too deep to be imaged by other OCT systems. This paper presents an OCT needle probe-based system that is capable of acquiring three-dimensional scans of tissue structures. The needle can be guided to a target area and scans acquired by rotating and pulling-back the probe. The system is demonstrated using ex vivo human lymph node and sheep lung samples. Multiplanar reconstructions are shown of both samples, as well as the first published 3D volume rendering ...

      Read Full Article
    8. Endoscopic optical coherence elastography using acoustic radiation force and bending vibration of optical Fiber

      Endoscopic optical coherence elastography using acoustic radiation force and bending vibration of optical Fiber
      We investigate endoscopic optical coherence elastography with micro-scale resolution using acoustic radiation force. The endoscopic optical scanner has vibration of an optical fiber for scanning the measurement light from an optical coherence tomography (OCT) system to sample tissue. The optical fiber with the length of mechanical resonance condition is vibrated in the bending mode using a cylindrical piezoelectric actuator driven by the phase-shifted voltages, and the output light from the optical fiber end is collimated by a small lens. The prototype of the scanner probe is 1 mm in diameter and 20 mm in length. Stress in the tissue is ...
      Read Full Article
    9. Numerical modelling of imaging fibre bundles and their application in optical coherence tomography

      Numerical modelling of imaging fibre bundles and their application in optical coherence tomography

      Imaging fibre bundles are widely used in image transmission systems in the visible spectral range1. Their image transmission capabilities and flexibility make them interesting for OCT endoscopy2. However, cross-talk occurring between individual fibres and multimode transmission cause deterioration of the images obtained with OCT systems. In this study, a model of light propagation in a fibre bundle is developed using the Finite Difference - Time Domain (FDTD) method in order to quantify these effects. The simulated bundle output power density distribution is compared to experimental images.

      Read Full Article
    10. Functional Diagnostic Imaging Apparatus By Endoscopic Optical Coherence Tomography

      Functional Diagnostic Imaging Apparatus By Endoscopic Optical Coherence Tomography
      The present invention relates to a functional diagnostic imaging apparatus by endoscopic optical coherence tomography comprises: a first laser diode for generating a first light signal; a second laser diode for generating a second light signal; a coupler for coupling the first and second light signals generated at the first and the second laser diodes; a circulator which receives the light signal from the coupler to transmit the received signal to a probe and receives a detection signal from the probe to transmit the received signal to a spectrometer; the probe in contact with tissue, which receives a light signal ...
      Read Full Article
    11. Opto-acoustic imaging devices and methods

      Opto-acoustic imaging devices and methods
      In one aspect, the invention relates to a probe. The probe includes a sheath, a flexible, bi-directionally rotatable, optical subsystem positioned within the sheath, the optical subsystem comprising a transmission fiber, the optical subsystem capable of transmitting and collecting light of a predetermined range of wavelengths along a first beam having a predetermined beam size. The probe also includes an ultrasound subsystem, the ultrasound subsystem positioned within the sheath and adapted to propagate energy of a predetermined range of frequencies along a second beam having a second predetermined beam size, wherein a portion of the first and second beams overlap ...
      Read Full Article
    12. Feature Of The Week 5/1/11: Caltech Researchers Develop an OCT Needle Probe for Investigating Open Angle Glaucoma

      Feature Of The Week 5/1/11: Caltech Researchers Develop an OCT Needle Probe for Investigating Open Angle Glaucoma
      Feature Of The Week 5/1/11: One major cause of Open Angle Glaucoma is the poor outflow of aqueous humor through the Trabecular Meshwork (TM). Potential treatments include the micro-bypass stents, which are implanted in the TM and shunt fluid directly to the Schlemm’s Canal (SC) to reduce intraocular pressure. Implanting the stent with the appropriate orientation near a major collector channel (CC) might maximize outflow of aqueous humor.As scleral tissue and the TM are not transparent to visible light, OCT using infrared light may be useful in visualizing and locating collector channels, hence could assist the ...
      Read Full Article
    13. Systems and methods for generating a tunable laser beam

      Systems and methods for generating a tunable laser beam
      Systems and methods of generating a tunable laser beam are disclosed. An example method includes: generating coherent optical beams from a plurality of semiconductor optical amplifiers (SOAs); combining the coherent optical beams into a combined coherent optical beam; and tuning the combined beam to a selected frequency range to output a coherent optical beam having only the selected frequency range. In some embodiments, the SOAs are arranged in parallel within a resonant cavity, and each coherent optical beam has a different center wavelength that overlaps in bandwidth with another one of the coherent optical beams.
      Read Full Article
    14. Optical rotary adaptor and optical tomographic imaging apparatus using the same

      Optical rotary adaptor and optical tomographic imaging apparatus using the same
      An optical rotary adapter is featured by including: a fixed side optical fiber which is fixedly supported by a fixed sleeve and which has an end surface inclined with respect to a plane perpendicular to the optical axis of the optical fiber; a fixed side collimator lens which is arranged to be separated from the inclined end surface of the fixed side optical fiber by a predetermined interval; a rotation side optical fiber which is fixedly supported substantially at the center of a rotatably supported rotary cylinder, which is arranged to face the fixed side collimator lens, and which has ...
      Read Full Article
    15. Optical scanning probe

      Optical scanning probe
      An optical scanning probe is provided and includes a housing, a diaphragm disposed in the housing, a rotor, a conduit, an optical fiber module, and a reflector disposed on the rotor, wherein the diaphragm and the housing forms a chamber. The rotor is movably disposed in the chamber and has several fans. The conduit is disposed in the housing to conduct fluid into the chamber, thus impelling the fans and the rotor. The optical fiber module is disposed in the housing and through the diaphragm to transmit a light beam. The reflector rotates with the rotor and reflects the light ...
      Read Full Article
    16. In situ imaging of lung alveoli with an optical coherence tomography needle probe

      In situ imaging of lung alveoli with an optical coherence tomography needle probe

      In situ imaging of alveoli and the smaller airways with optical coherence tomography (OCT) has significant potential in the assessment of lung disease. We present a minimally invasive imaging technique utilizing an OCT needle probe. The side-facing needle probe comprises miniaturized focusing optics consisting of no-core and GRIN fiber encased within a 23-gauge needle. 3D-OCT volumetric data sets were acquired by rotating and retracting the probe during imaging. The probe was used to image an intact, fresh (not fixed) sheep lung filled with normal saline, and the results validated against a histological gold standard. We present the first published images ...

      Read Full Article
    17. A common-path optical coherence tomography distance-sensor based surface tracking and motion compensation hand-held microsurgical tool

      A common-path optical coherence tomography distance-sensor based surface tracking and motion compensation hand-held microsurgical tool
      Microsurgery requires constant attention to the involuntary motion due to physiological tremors. In this work, we demonstrated a simple and compact hand-held microsurgical tool capable of surface tracking and motion compensation based on common-path optical coherence tomography (CP-OCT) distance-sensor to improve the accuracy and safety of microsurgery. This tool is miniaturized into a 15mm-diameter plastic syringe and capable of surface tracking at less than 5 micrometer resolution. A phantom made with Intralipid layers is used to simulate a real tissue surface and a single-fiber integrated micro-dissector works as a surgical tip to perform tracking and accurate incision on the phantom ...
      Read Full Article
    18. Detection of inflating balloon in optical coherence tomography images of a porcine artery in a beating heart experiment

      Detection of inflating balloon in optical coherence tomography images of a porcine artery in a beating heart experiment

      Suboptimal results of angioplasty procedures have been correlated to arterial damage during balloon inflation. We propose to monitor balloon inflation during the angioplasty procedure by detecting the balloon contours with intravascular optical coherence tomography (IVOCT). This will shed more light on the interaction between the balloon and the artery and to assess the artery's mechanical response. An automatic edge detection algorithm is applied for detection of the outer surface of an inflating balloon in a porcine artery in a beating heart experiment. A compliant balloon is inflated to deform the artery. IVOCT monitoring of balloon inflation is performed at ...

      Read Full Article
    19. Dual angle scan protocol with Doppler optical coherence tomography for retinal blood flow measurement

      Dual angle scan protocol with Doppler optical coherence tomography for retinal blood flow measurement

      To improve the scan quality of Doppler Optical coherence tomography for blood flow measurement, we investigate how to improve the Doppler signal for all vessels around optic disc. Doppler signal is depending on the Doppler angle, which is defined as angle between OCT beams and normal direction vessel. In this examination, we test the effect of different OCT beam direction on Doppler angles of all veins. We also test maximizing the Doppler angle by combining scans with different OCT beams direction. Three criteria were used to evaluate the overall quality, average Doppler angle, the percentage of vessels with Doppler angle ...

      Read Full Article
    20. Measuring soft tissue elasticity by monitoring surface acoustic waves using image plane digital holography

      Measuring soft tissue elasticity by monitoring surface acoustic waves using image plane digital holography

      The detection of tumors in soft tissues, such as breast cancer, is important to achieve at the earliest stages of the disease to improve patient outcome. Tumors often exhibit a greater elastic modulus compared to normal tissues. In this paper, we report our first study to measure elastic properties of soft tissues by mapping the surface acoustic waves (SAWs) with image plane digital holography. The experimental results show that the SAW velocity is proportional to the square root of elastic modulus over a range from 3.7-122kPa in homogeneous tissue phantoms, consistent with Rayleigh wave theory. This technique also permits ...

      Read Full Article
    21. Toward better treatment of clogged arteries

      Toward better treatment of clogged arteries
      Real-time detailed monitoring of angioplasty balloon deformation may lead to improved medical devices to treat hardened artery walls. Intravascular optical coherence tomography (IVOCT) is a catheter-based technique that provides detailed cross-sectional imaging of the artery wall with a resolution of the order of ten micrometers. The clinical relevance of IVOCT has been demonstrated in many studies for the diagnosis and treatment monitoring of atherosclerosis1 (hardening and/or thickening of arteries by deposited plaques of cholesterol and other lipids, inflammatory cells, and calcium deposits). The technology is mature enough to be distributed commercially.2 Images may be acquired during a ‘pullback ...
      Read Full Article
    22. Integrated optical coherence tomography - ultrasound system and miniaturized probes for intravascular imaging

      Integrated optical coherence tomography - ultrasound system and miniaturized probes for intravascular imaging

      We report on the development of a multimodal optical coherence tomography (OCT) - ultrasound (US) system and miniaturized OCT-US probe for intravascular imaging. Both OCT optical components and a US transducer were integrated into a single probe, enabling both OCT and US imaging at the same time. A miniaturized OCT-US probe using a single element transducer was designed with a maximum outer diameter of 0.8 mm, which is suitable for in vivo intravascular imaging. The integrated OCT-US imaging system adopted a two-channel data acquisition card to digitize both OCT and US signals. Simultaneous OCT and US data processing and image ...

      Read Full Article
    23. The impact of aberrations on object reconstruction with interferometric synthetic aperture microscopy

      The impact of aberrations on object reconstruction with interferometric synthetic aperture microscopy

      Interferometric synthetic aperture microscopy (ISAM) reconstructs the scattering potential of a sample with spatially invariant resolution, based on the incident beam profile, the beam scan pattern, the physical model of light sample interaction, and subsequent light collection by the system. In practice, aberrations may influence the beam profile, particularly at higher NA, when ISAM is expected to provide maximum benefit over optical coherence microscopy. Thus it is of interest to determine the effects of aberrations on ISAM reconstructions. In this paper we present the forward model incorporating the effects of aberrations, which forms the basis for aberration correction in ISAM ...

      Read Full Article
    24. Piezoelectric transducer based miniature catheter for ultrahigh speed endoscopic optical coherence tomography

      Piezoelectric transducer based miniature catheter for ultrahigh speed endoscopic optical coherence tomography

      We developed a piezoelectric transducer (PZT) based miniature catheter with an outer diameter of 3 mm for ultrahigh speed endoscopic optical coherence tomography (OCT) using Fourier domain modelocked (FDML) laser at a 480 kHz axial scan rate. The miniaturized PZT bender actuates a fiber to provide high scanning speed. The side-viewing probe can be pulled back for a long distance to acquire three-dimensional (3D) dataset covering a large area on the specimen. Operating with a high speed data acquisition (DAQ) system, OCT imaging with 6.5 mm imaging range, 10 μm axial resolution, 20 μm lateral resolution, and frame rate ...

      Read Full Article
    241-264 of 422 « 1 2 ... 8 9 10 11 12 13 14 ... 16 17 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
  2. Popular Articles

  3. Organizations in the News

    1. (1 articles) Massachusetts General Hospital
    2. (1 articles) Harvard University
    3. (1 articles) Delft University of Technology
    4. (1 articles) Chinese Academy of Sciences
    5. (1 articles) Erasmus University
  4. People in the News

    1. (1 articles) Gijs van Soest
    2. (1 articles) Guillermo J. Tearney
    3. (1 articles) Tianshi Wang
    4. (1 articles) Milen Shishkov
    5. (1 articles) Brett E. Bouma
    6. (1 articles) Benjamin J. Vakoc
    7. (1 articles) Norman S. Nishioka
    8. (1 articles) Anton F. W. van der Steen