1. Articles from J. Walther

    1-8 of 8
    1. Quality Assessment of Tympanoplasty by Means of Endoscopic Optical Coherence Tomography

      Quality Assessment of Tympanoplasty by Means of Endoscopic Optical Coherence Tomography

      Introduction: The endoscopic optical coherence tomography (eOCT) allows the direct, contactless representation and evaluation of the morphology and oscillation behaviour of the tympanic membrane and adjoining tympanic cavity content. After further development of the measuring technology, the eOCT will be able to be used in vivo for the assessment of tympanoplasty results. Materials and Methods: The eOCT was applied to 10 patients after a tympanoplasty with an intact ossicular chain and to 10 patients after a Type III tympanoplasty. The measurement data of the morphology – especially the thickness – and oscillation behaviour of the tympanic membrane and the prosthesis coupling to ...

      Read Full Article
    2. Endoscopic Optical Coherence Tomography in Diagnostics of Otosclerosis

      Endoscopic Optical Coherence Tomography in Diagnostics of Otosclerosis

      Introduction: Endoscopic Optical Coherence Tomography (eOCT) enables both high-resolution contact-free 3D-imaging of the tympanic membrane and spatial and frequency-resolved oscillation measurement via Doppler-OCT. Thus it is possible to detect causes of conduction hearing loss. In case of otosclerosis, changes in oscillation amplitude at the umbo had been showed via Laser-Doppler-Vibrometry. Material and Methods: The eOCT system utilizes a swept source laser with a wave length around 1300nm. Field-of-view and working distance are 10 mm. Sound stimulus was a Chirp in the frequency range between 0.5 and 5 kHz at 95 dB. Morphological and functional measurements were done on 12 ...

      Read Full Article
    3. A System for Clinical Use of Endoscopic Optical Coherence Tomography

      A System for Clinical Use of Endoscopic Optical Coherence Tomography

      Introduction: Optical Coherence Tomography (OCT) allows non-invasive high-resolution imaging of tissues. With a penetration depth of a few millimeters it's possible to image the tympanic membrane and the close-by part of the tympanum, e.g. for diagnostics of otitis media and middle ear effusion. In the field of in vivo examination there are difficulties in access to the human tympanic membrane due to the narrow and curved external ear canal. We report a compact endoscopic OCT system for use in clinical research. Methods: We use a 3,5 mm endoscopic GRIN lens for video endoscopy and OCT. OCT is ...

      Read Full Article
    4. 4D in vivo imaging of subpleural lung parenchyma by swept source optical coherence tomography

      4D in vivo imaging of subpleural lung parenchyma by swept source optical coherence tomography
      In this feasibility study we present a method for 4D imaging of healthy and injured subpleural lung tissue in a mouse model. We used triggered swept source optical coherence tomography with an A-scan frequency of 20 kHz to image murine subpleural alveoli during the ventilation cycle. The data acquisition was gated to the pulmonary airway pressure to take one B-scan in each ventilation cycle for different pressure levels. The acquired B-scans were combined offline to one C-scan for each pressure level. Due to the high acquisition rate of the used optical coherence tomography system, we are also able to perform ...
      Read Full Article
    5. Analysis of Murine Vascular Function In Vivo by Optical Coherence Tomography in Response to High-fat Diet

      In this study, we demonstrate the application of optical coherence tomography (OCT) as a contactless imaging technique to analyze vasodynamics in small blood vessels in vivo. The transluminal OCT imaging of vessels avoids micro traumata in the endothelium and circumvents surgical intervention. It can be performed in the intact perfused vessel and provides a new method to measure vascular function and dynamics in vivo. The resolution of 10 μm and the velocity of image acquisition are adequate to detect differences in the inner diameter, the maximal velocity, or the time to half-maximal diameter change of small vessels. We applied this ...
      Read Full Article
    6. Phase-resolved Doppler Fourier Domain Optical Coherence Tomography in the in vivo mouse model

      Blood flow velocities within vasodynamic measurements in the in vivo mouse model were imaged by using phase-resolved Doppler Fourier Domain Optical Coherence Tomography with a spectrum read-out rate of 12 kHz. The high temporal resolution of the system is used to quantify the pulse from real-time cross-sectional images of the murine saphenous artery. The Doppler method was evaluated by imaging a 1% Intralipid emulsion flowing through a glass capillary with an inner diameter of approximately 320 um.
      Read Full Article
    7. Transverse and oblique motion effects in Fourier Domain Optical Coherence Tomography

      In this study we describe the effects on the interference signal caused by transverse and oblique motion in spatially encoded Fourier Domain Optical Coherence Tomography (FD OCT). The artifacts caused by sample motion were analyzed theoretically and experimentally. The presented results supply an understanding of the SNR degradation caused by sample motion and demonstrates the importance of fast data acquisition in medical imaging.
      Read Full Article
    8. Velocity Analysis by Using Doppler Fourier Domain Optical Coherence Tomography with Variable Reference Length

      The measurement of blood flow is important in studying the pathophysiology and treatment of several diseases of blood vessels, like atherosclerosis. We present a method for flow measurement using resonant Doppler imaging with spectrometer based Fourier Domain Optical Coherence Tomography (FD-OCT). A modified Michelson interferometer, integrated in a 3D scanner head, with a variable reference length is used to determine velocities. Two methods are applied where cross-sectional images (B-scans) are taken while the reference arm for each depth scan (A-scan) has different states. In the 2- state method the reference mirror is moving axial towards respectively backwards in successive A-scans ...
      Read Full Article
    1-8 of 8
  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. Topics in the News

    1. (8 articles) Julia Walther
    2. (8 articles) Edmund Koch
    3. (7 articles) Dresden University of Technology
    4. (3 articles) Lars Kirsten
    5. (2 articles) Henning Morawietz
    6. (2 articles) Sven Meissner
    7. (1 articles) Mikael Timo Erkkilä
  3. Popular Articles

  4. Picture Gallery

    4D in vivo imaging of subpleural lung parenchyma by swept source optical coherence tomography A System for Clinical Use of Endoscopic Optical Coherence Tomography Endoscopic Optical Coherence Tomography in Diagnostics of Otosclerosis Quality Assessment of Tympanoplasty by Means of Endoscopic Optical Coherence Tomography An air of optimism takes hold for CF sufferers Optical coherence tomography for dynamic axial correction of an optical end-effector for robot-guided surgical laser ablation Optical Coherence Tomography Angiography to Assess Vascular Remodeling of the Choriocapillaris After Low-Fluence Photodynamic Therapy for Chronic Central Serous Chorioretinopathy Automatic Classification of Retinal Optical Coherence Tomography Images With Layer Guided Convolutional Neural Network Diagnostic accuracy of intracoronary optical coherence tomography-derived fractional flow reserve for assessment of coronary stenosis severity Segmentation of Retinal Cysts From Optical Coherence Tomography Volumes Via Selective Enhancement OCT Signs Associated With Fellow Eye AMD Progression Convective Nozaki-Bekki holes in a long cavity OCT laser