Otolaryngology -Optical Coherence Tomography News

Articles in category: Otolaryngology

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1. Motion of intracochlear structures measured with a commercial optical coherence tomography (OCT) system
  
  Explore asa.scitation.org Jun 25 2017 Otolaryngology
  
  Most knowledge of the motion of cochlear structures has been limited to measurements through the round window at the extreme base of the cochlea or through a hole made in the cochlear capsule, which can modify cochlear mechanics. Optical coherence tomography (OCT) provides the ability to measure shape or motion of structures through a thin layer of tissue or bone. The motion of cochlear structures has been measured in the mouse cochlear apex without making an opening into the cochlea, using a custom OCT system. Here we describe intracochlear vibrometry using a commercial OCT system. Specimens were prepared by opening ...
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  Mentions: Thorlabs
2. Integrating optical coherence tomography with laryngeal videostroboscopy
  
  Explore asa.scitation.org Jun 25 2017 Otolaryngology
  
  During clinical voice assessment, laryngologists and speech-language pathologists rely heavily on laryngeal endoscopy with videostroboscopy to evaluate pathology and dysfunction of the vocal folds. The cost effectiveness, ease of use, and synchronized audio and visual feedback provided by videostroboscopic assessment serve to maintain its predominant clinical role in laryngeal imaging. However, significant drawbacks include only two-dimensional spatial imaging and the lack of subsurface morphological information. A novel endoscope will be presented that integrates optical coherence tomography that is spatially and temporally co-registered with laryngeal videoendoscopic technology through a common path probe. Optical coherence tomography is a non-contact, micron-resolution imaging technology ...
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  Mentions: Massachusetts General Hospital Harvard University Physical Sciences Incorporated
3. Stroboscope, High-Speed Imaging, Videokymography and Optical Coherence Tomography (Book Chapter)
  
  Explore Google Books Jun 20 2017 Otolaryngology , Textbooks
  
  Dysphonia is the consequence of a number of structural, neurological or developmental anomalies of the larynx...
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4. Stanford University Receives NIH Grant for Cochlear Mechanics in the Mouse
  
  Explore Optical Coherence Tomography News May 9 2017 Otolaryngology , Funding
  
  Stanford University Receives a 2017 NIH Grant for $307,982 for Cochlear Mechanics in the Mouse. The principal investigator is John Oghalai. The program began in 2015 and ends in 2020. Below is a summary of the proposed work. Sound pressure produces force across the mammalian cochlear partition, ultimately creating a vibratory traveling wave that propagates longitudinally up the cochlear duct. The key feature distinguishing this process from the non-mammalian cochlea is amplification, whereby forces produced by thousands of outer hair cells (OHCs) sharpen and amplify the traveling wave. Our overarching objective is to understand how the complex biomechanics of ...
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  Mentions: National Institutes of Health Stanford University
5. Stanford Receives NIH Grant for Optical Coherence Tomography for 3D Measures of Cochlear Mechanics In Vivo
  
  Explore Optical Coherence Tomography News Apr 4 2017 Otolaryngology , Funding
  
  Stanford University Receives a 2017 NIH Grant for $364,249 for Optical Coherence Tomography for 3D Measures of Cochlear Mechanics In Vivo. The principal investigator is John Oghalai. The program began in 2015 and ends in 2020. Below is a summary of the proposed work. The function of the cochlea is to transduce complex sound pressure waves into electrical signals. Organ of Corti vibration is based upon a complex interplay between passive mechanical structures and active OHC- based processes. While laser Doppler vibrometry has added tremendously to our understanding of cochlear physiology, this technique is limited. Only motion from one ...
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  Mentions: National Institutes of Health Stanford University
6. Stanford Receives NIH Grant f for Influence of Hair Bundle Properties on Cochlear Mechanics
  
  Explore Optical Coherence Tomography News Apr 4 2017 Otolaryngology , Funding
  
  Stanford University Receives a 2017 NIH Grant for $56,694 for Influence of Hair Bundle Properties on Cochlear Mechanics. The principal investigator is James Dewey. The program began in 20-17 and ends in 2020. Below is a summary of the proposed work. Normal hearing depends on the delicate mechanotransduction apparatus of inner ear hair cells – the stereociliary hair bundle. Cochlear vibrations deflect the hair bundle, which converts mechanical stimulation to electrical signals via gating of mechanosensitive ion channels. Hair bundle transduction is critical for hearing, as it is required for afferent signaling by inner hair cells, and for activation of ...
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  Mentions: National Institutes of Health Stanford University
7. In vivo 3D imaging of the human tympanic membrane using a wide-field diagonal-scanning optical coherence tomography probe
  
  Explore OSA | OSA Publishing Feb 27 2017 Otolaryngology , Probes
  
  A wide-field optical coherence tomography (OCT) probe was developed that adapts a diagonal-scanning scheme for three-dimensional (3D) in vivo imaging of the human tympanic membrane. The probe consists of a relay lens to enhance the lateral scanning range up to 7 mm. Motion artifacts that occur with the use of handheld probes were found to be decreased owing to the diagonal-scanning pattern, which crosses the center of the sample to facilitate entire 3D scans. 3D images could be constructed from a small number of two-dimensional OCT images acquired using the diagonal-scanning technique. To demonstrate the usefulness and performance of the ...
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  Mentions: Stephen A. Boppart Harvard University University of Illinois at Urbana-Champaign
8. Seeing, understanding how we hear
  
  Explore Nova Scotia News Feb 24 2017 Otolaryngology
  
  Cutting-edge technology is giving QEII Health Sciences Centre clinicians a close up look at the inner workings of the human ear. “We are the only place in the world that has managed to measure ear vibrations in humans. We are definitely the furthest ahead,” says Dr. Manohar Bance, QEII ear surgeon. When it comes to middle ear dysfunctions, surgeries to cut open the tympanic membrane, or eardrum, are frequently conducted on patients in attempt to identify problems and restore vibrating connections. Anything that can block the passage of vibrations will lead to hearing loss. Fluid is one thing, which is ...
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  Mentions: Dalhousie University
9. Intraoperative assessment of laryngeal pathologies with optical coherence tomography integrated into a surgical microscope
  
  Explore Wiley Online Library Feb 23 2017 Oncology , Otolaryngology
  
  Objective Endoscopic examination followed by tissue biopsy is the gold standard in the evaluation of lesions of the upper aerodigestive tract. However, it can be difficult to distinguish between healthy mucosa, dysplasia, and invasive carcinoma. Optical coherence tomography (OCT) is a non-invasive technique which acquires high-resolution, cross-sectional images of tissue in vivo . Integrated into a surgical microscope, it allows the intraoperative evaluation of lesions simultaneously with microscopic visualization. Study Design In a prospective case series, we evaluated the use of OCT integrated into a surgical microscope during microlaryngoscopy to help differentiating various laryngeal pathologies. Methods 33 patients with laryngeal pathologies ...
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  Mentions: Haag-Streit Herbert Stepp OPMedt
10. Extratympanic imaging of middle and inner ear structures of mouse and rat using optical coherence tomography
  
  Explore Conference Proceedings Feb 11 2017 Otolaryngology
  
  ackground and Objective: Noninvasive middle and inner ear imaging using optical coherence tomography (OCT) presents some unique challenges for real-time, clinical use in animals and humans. The goal of this study was to investigate whether OCT provides information about the middle and inner ear microstructures by examining extratympanic structures. Materials and Methods: Five mice and rats were included in the experiment, and the swept-source OCT system was tested to identify the middle and inner ear microstructures and to measure the length or thickness of various structures. Results: It was possible to see middle ear structures through the tympanic membrane with ...
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11. Signal competition in optical coherence tomography and its relevance for cochlear vibrometry
  
  Explore asa.scitation.org Jan 25 2017 Otolaryngology
  
  The usual technique for measuring vibration within the cochlear partition is heterodyne interferometry. Recently, spectral domain phase microscopy (SDPM) was introduced and offers improvements over standard heterodyneinterferometry. In particular, it has a penetration depth of several mm due to working in the infrared range, has narrow and steep optical sectioning due to using a wideband light source, and is able to measure from several cochlear layers simultaneously. However, SDPM is susceptible to systematic error due to “phase leakage,” in which the signal from one layer competes with the signal from other layers. Here, phase leakage is explored in vibration measurements ...
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  Mentions: Christine Hendon
12. Low-cost hand-held probe for depth-resolved low-coherence interferometry
  
  Explore OSA | OSA Publishing Jan 20 2017 Otolaryngology , Probes
  
  We report on the development of a low-cost hand-held low-coherence interferometric imaging system based on the principle of linear optical coherence tomography (Linear OCT), a technique which was first proposed in the early 2000s as a simpler alternative to the conventional time-domain and Fourier-domain OCT. A bench-top implementation of the proposed technique is first presented and validated. The axial resolution, SNR, and sensitivity roll-of of the system was estimated to be 5.2 μm and 80 dB, and 3.7 dB over a depth of 0.15 mm, respectively. After validating the bench-top system, two hand-held probe implementations for contact-based ...
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  Mentions: Stephen A. Boppart University of Illinois at Urbana-Champaign Ryan L. Shelton
13. Experimental Visualization of Labyrinthine Structure with Optical Coherence Tomography
  
  Explore Iranian Journal of Otorhinolaryngology Dec 30 2016 Otolaryngology
  
  Introduction: Visualization of inner ear structures is a valuable strategy for researchers and clinicians working on hearing pathologies. Optical coherence tomography (OCT) is a high-resolution imaging technology which may be used for the visualization of tissues. In this experimental study we aimed to evaluate inner ear anatomy in well-prepared human labyrinthine bones. Materials and Methods: Three fresh human explanted temporal bones were trimmed, chemically decalcified with ethylenediaminetetraacetic acid (EDTA), and mechanically drilled under visual control using OCT in order to reveal the remaining bone shell. After confirming decalcification with a computed tomography (CT) scan, the samples were scanned with OCT ...
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  Mentions: University of Hannover
14. Mesenchymal stem cell-laden hybrid scaffold for regenerating subacute tympanic membrane perforation
  
  Explore ScienceDirect Dec 3 2016 Otolaryngology
  
  ympanic membrane (TM) perforation is one of the most common otology complications. To date, there has not been reported TM regeneration using bioprinted scaffold. The purpose of this study was to evaluate the efficacy and feasibility of bioprinted polycaprolactone/collagen/alginate-mesenchymal stem cell (PCAMSC) scaffolds for the regeneration of subacute TM perforation. Sprague-Dawley rats were used in an animal model of subacute TM perforation. In the experimental group (n = 7), bioprinted 3D PCAMSC scaffold was placed on the perforation. The control group (n = 7) were treated with polycaprolactone/collagen/alginate (PCA) scaffold. Healing time, acoustic-mechanical properties, and morphological analysis were ...
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  Mentions: Byeong Ha Lee
15. Dynamic nanomechanical analysis of the vocal fold structure in excised larynges
  
  Explore Wiley Online Library Nov 22 2016 Otolaryngology
  
  Objectives/Hypothesis Quantification of clinical outcomes after vocal fold (VF) interventions is challenging with current technology. High-speed digital imaging and optical coherence tomography (OCT) of excised larynges assess intact laryngeal function, but do not provide critical biomechanical information. We developed a protocol to quantify tissue properties in intact, excised VFs using dynamic nanomechanical analysis (nano-DMA) to obtain precise biomechanical properties in the micrometer scale. Study Design Experimental animal study. Methods Three pig larynges were bisected in the sagittal plane, maintaining an intact anterior commissure, and subjected to nano-DMA at nine locations with a 250-μm flat-tip punch and frequency sweep ...
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16. Human ex-vivo oral tissue imaging using spectral domain polarization sensitive optical coherence tomography
  
  Explore Home - Springer Nov 9 2016 Otolaryngology
  
  We report the use of spectral domain polarization sensitive optical coherence tomography for ex-vivo imaging of human oral mandibular tissue samples. Our results show that compared to the changes observed in the epithelium thickness and the decay constant of A-scan intensity profile, a much larger degree of change was observed in the phase retardation for tissue sites progressing from normal to the malignant state. These results suggest that monitoring of tissue retardance can help in better differentiation of normal and cancerous oral tissue sites.
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  Mentions: Massachusetts General Hospital Harvard University Khageswar Sahu
17. Doppler optical coherence tomography as a promising tool for detecting fluid in the human middle ear
  
  Explore Home Oct 23 2016 Otolaryngology
  
  The treatment of otitis media requires classifying the effusion in the tympanic cavity for choosing appropriate therapeutic strategies. Otoscopic examination of the middle ear depends on the expertise of the physician and is often hampered in case of inflammatory alterations of the tympanic membrane. In otologic research, optical coherence tomography is an innovative non-invasive imaging technique utilized for visualizing the tympanic membrane. This ex vivo study presents the possibility of OCT and Doppler-OCT for the detection of effusions in the tympanic cavity. Structural OCT imaging allows the direct visualization of scattering fluids behind the tympanic membrane. In addition, the measurement ...
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  Mentions: Dresden University of Technology Edmund Koch Lars Kirsten
18. Long-range, wide-field swept-source optical coherence tomography with GPU accelerated digital lock-in Doppler vibrography for real-time, in vivo middle ear diagnostics
  
  Explore OSA | OSA Publishing Oct 18 2016 Otolaryngology
  
  We present the design, implementation and validation of a swept-source optical coherence tomography (OCT) system for real-time imaging of the human middle ear in live patients. Our system consists of a highly phase-stable Vernier-tuned distributed Bragg-reflector laser along with a real-time processing engine implemented on a graphics processing unit. We use the system to demonstrate, for the first time in live subjects, real-time Doppler measurements of middle ear vibration in response to sound, video rate 2D B-mode imaging of the middle ear and 3D volumetric B-mode imaging. All measurements were performed non-invasively through the intact tympanic membrane demonstrating that the ...
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  Mentions: Dalhousie University
19. Micro-optical coherence tomography of the mammalian cochlea
  
  Explore Nature Publishing Group Sep 20 2016 Otolaryngology
  
  The mammalian cochlea has historically resisted attempts at high-resolution, non-invasive imaging due to its small size, complex three-dimensional structure, and embedded location within the temporal bone. As a result, little is known about the relationship between an individual’s cochlear pathology and hearing function, and otologists must rely on physiological testing and imaging methods that offer limited resolution to obtain information about the inner ear prior to performing surgery. Micro-optical coherence tomography (μOCT) is a non-invasive, low-coherence interferometric imaging technique capable of resolving cellular-level anatomic structures. To determine whether μOCT is capable of resolving mammalian intracochlear anatomy, fixed guinea pig ...
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  Mentions: Guillermo J. Tearney Massachusetts General Hospital Harvard University
20. A Mosaicking Approach for In Vivo Thickness Mapping of the Human Tympanic Membrane Using Low Coherence Interferometry
  
  Explore Home - Springer Sep 17 2016 Otolaryngology
  
  The thickness of the human tympanic membrane (TM) is known to vary considerably across different regions of the TM. Quantitative determination of the thickness distribution and mapping of the TM is of significant importance in hearing research, particularly in mathematical modeling of middle-ear dynamics. Change in TM thickness is also associated with several middle-ear pathologies. Determination of the TM thickness distribution could therefore also enable a more comprehensive diagnosis of various otologic diseases. Despite its importance, very limited data on human TM thickness distribution, obtained almost exclusively from ex vivo samples, are available in the literature. In this study, the ...
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  Mentions: Stephen A. Boppart University of Illinois at Urbana-Champaign Ryan L. Shelton
21. Biomedical Optics in Otorhinolaryngology (Textbook)
  
  Explore Springer US Sep 1 2016 Otolaryngology , Textbooks
  
  Biomedical Optics in Otorhinolaryngology: Head and Neck Surgery gives an overview of current technology in biomedical optics relevant to the field of Otorhinolaryngology and head and neck surgery. It provides a comprehensive source of knowledge for researchers and active clinicians seeking information on the principles and practical use of novel diagnostic and therapeutic technology. While most books focus exclusively on laser surgery, which has been largely unchanged for the past 15 years, optical diagnostics and head and neck PDT (photodynamic therapy) are usually entirely overlooked. This book contains a basic introduction into the physics of light and its propagation, lasers ...
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  Mentions: UC Irvine RWTH Aachen University Brian J. F. Wong
22. Diagnosis of subglottic stenosis in a rabbit model using long-range optical coherence tomography
  
  Explore Wiley Online Library Aug 25 2016 Otolaryngology
  
  Objectives/Hypothesis Current imaging modalities lack the necessary resolution to diagnose subglottic stenosis. The aim of this study was to use optical coherence tomography (OCT) to evaluate nascent subglottic mucosal injury and characterize mucosal thickness and structural changes using texture analysis in a simulated intubation rabbit model. Study Design Prospective animal study in rabbits. Methods Three-centimeter-long sections of endotracheal tubes (ETT) were endoscopically placed in the subglottis and proximal trachea of New Zealand White rabbits (n = 10) and secured via suture. OCT imaging and conventional endoscopic video was performed just prior to ETT segment placement (day 0), immediately after tube ...
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  Mentions: Zhongping Chen UC Irvine Brian J. F. Wong
23. OPTICAL COHERENCE TOMOGRAPHY IN THE LARYNGEAL ARYTENOID MUCOSA FOR DOCUMENTATION OF PHARMACOLOGICAL TREATMENTS AND GENETIC ASPECTS: A PROTOCOL
  
  Explore Co-Action Publishing JOURNALS Aug 2 2016 Otolaryngology
  
  Background : Optical coherence tomography (OCT) is an imaging technology that provides cross-sectional images of subsurface tissue structures in the larynx without biopsy. Focus has until now been on the vocal folds. Since many kinds of mucosal disorders can be defined in the arytenoid regions behind the vocal folds, and not on the vocal folds, we focus on this area in this protocol. Objective : A superficial oedema, grading 1–5 of the arytenoid regions, can be made with high-speed films of 4,000 pictures/sec. A supplementary larynx set up with a clinical probe for OCT with cross-sectional measures can be ...
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24. Minimal basilar membrane motion in low-frequency hearing
  
  Explore pnas.org Jul 12 2016 Otolaryngology
  
  To perceive speech, the brain relies on inputs from sensory cells located near the top of the spiral-shaped cochlea. This low-frequency region of the inner ear is anatomically difficult to access, and it has not previously been possible to study its mechanical response to sound in intact preparations. Here, we used optical coherence tomography to image sound-evoked vibration inside the intact cochlea. We show that low-frequency sound moves a small portion of the basilar membrane, and that the motion declines in an exponential manner across the basilar membrane. Hence, the response of the hearing organ to speech-frequency sounds is different ...
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  Mentions: Imperial College London Oregon Health & Science University University of Washington
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