Category: Otolaryngology

Chronic rhinosinusitis with nasal polyposis (CRSwNP) is a multifactorial disease that seems to be associated with the presence of microbial biofilms and corresponding subepithelial inflammatory reactions. Optical coherence tomography (OCT) might be applied to detect bacterial and fungal biofilms in patients with CRSwNP. A total of 27 patients with CRSwNP undergoing endoscopic sinus surgery (ESS) were analyzed. The negative control group consisted of six patients undergoing septoplasty for nasal obstruction without CRSwNP. The nasal polyps and inferior turbinate mucosa specimens applied as negative controls were processed to OCT analysis and H.E. and Gram staining. Biofilm was detected in 22 ...

One current challenge of studying human tympanic membranes (TM) with optical coherence tomography (OCT) is the implementation of optics that avoid direct contact with the inflamed tissue. At the moment, no commercial device is available. We report an optics design for contactless forward imaging endoscopic optical coherence tomography (EOCT) with a large working distance (WD) and a broad field of view (FOV) by restricting the overall diameter of the probe to be small (3.5 mm), ensuring a sufficient numerical aperture. Our system uses a gradient-index (GRIN) relay lens and a GRIN objective lens, and executes a fan-shaped optical scanning ...

Background Mammalian hearing is refined by amplification of the sound-evoked vibration of the cochlear partition. This amplification is at least partly due to forces produced by protein motors residing in the cylindrical body of the outer hair cell. To transmit power to the cochlear partition, it is required that the outer hair cells dynamically change their length, in addition to generating force. These length changes, which have not previously been measured in vivo, must be correctly timed with the acoustic stimulus to produce amplification. Methodology/Principal Findings Using in vivo optical coherence tomography, we demonstrate that outer hair cells in ...

A sensing system for implant surgery includes an insertion device for moving an implant into a narrow cavity in a patient's body. A sensor measures the distance from an end of the insertion device to anatomic surfaces at a distance from the end of the insertion device. An optical coherence tomography (OCT) system integrates the sensor and produces OCT images, which can be quantified to distance measurements. The system is particularly useful for cochlear implant surgery.

A method and apparatus for generating a three dimensional representation of an ear canal are disclosed whereby an ear canal of a patient is imaged using optical coherence tomography (OCT). In a first embodiment, cross-section images of an ear canal are taken by, for example, rotating an OCT imaging sensor about a predetermined axis at each of a plurality of positions. In accordance with another embodiment, a contour line is then identified in each of the cross section images and a flow algorithm is used to identify the boundary of the ear canal cross section. Once the boundaries of each ...

We describe a novel method for the detection of the tiny motions of the middle ear (ME) ossicles and their morphological features with a spectral-domain phase sensitive optical coherence tomography (PS-OCT). Laser Doppler Vibrometry (LDV) and its variations are the most extensively used methods for studding the vibrational modes of the ME. However, most techniques are limited to single point analysis methods, and do not have the ability to provide depth resolved simultaneous imaging of multiple points on the ossicles especially with the intact eardrum. Consequently, the methods have the limited ability to provide relative vibration information at these points ...

Direct measurement of absolute vibration parameters from different locations within the mammalian organ of Corti is crucial for understanding the hearing mechanics such as how sound propagates through the cochlea and how sound stimulates the vibration of various structures of the cochlea, namely, basilar membrane (BM), recticular lamina, outer hair cells and tectorial membrane (TM). In this study we demonstrate the feasibility a modified phase-sensitive spectral domain optical coherence tomography system to provide subnanometer scale vibration information from multiple angles within the imaging beam. The system has the potential to provide depth resolved absolute vibration measurement of tissue microstructures from ...

Clinical diagnosis of cochlear dysfunction typically remains incomplete due to a lack of proper diagnostic methods. Medical imaging modalities can only detect gross changes in the cochlea, and non-invasive in vivo cochlear measurements are scarce. As a result, extensive efforts have been made to adapt optical coherence tomography (OCT) techniques to analyze and study the cochlea. Herein, we detail the methods for measuring vibration using OCT. We used spectral domain OCT with ~950 nm as the center wavelength and a bandwidth of ~80 nm. The custom spectrometer used was based on a high speed line scan camera which is capable ...

A method of forming an image of tissue. The method includes non-invasively inserting a fiber-based device into a patient's ear canal and acquiring OCT data from ear tissue while the fiber-based device is in the ear canal. The method also includes converting the OCT data into at least one image.

Background The purpose of the present study was to determine normal values of epithelial thickness within the oral cavity by using optical coherence tomography (OCT). MethodsIn a total of 143 healthy test persons, epithelial thickness of the oral mucosa was determined with the help of OCT separately for each side at 7 different locations. Special attention was directed to those sites having the highest incidence for the development of dysplasias and carcinomas.ResultsThe epithelium demonstrated a varying thickness depending on its location within the oral cavity. The highest values were found in the region of the buccal mucosa (294 μm ...

A miniature endoscope probe for forward viewing in a 50 kHz swept source optical coherence tomography (SS-OCT) configuration was developed. The work presented here is an intermediate step in our research towards in vivo endoscopic laryngeal cancer screening. The endoscope probe consists of a miniature tubular lead zirconate titanate (PZT) actuator, a single mode fiber (SMF) cantilever and a GRIN lens, with a diameter of 2.4 mm. The outer surface of the PZT actuator is divided into four quadrants that form two pairs of orthogonal electrodes (X and Y). When sinusoidal waves of opposite polarities are applied to one ...

Emerging Applications for Optical Coherence Tomography in the Head, Neck, and Upper Airway spie.org From the BiOS Hot Topics session at SPIE Photonics West 2012. Brian Wong from the Beckman Laser Institute and Medical Clinic gave this presentation titled "Emerging Applications for Optical Coherence Tomography in the Head, Neck, and Upper Airway"

Vocal fold vibration is vital in voice production and the correct pitch of speech. University of California Irvine researchers have developed a high speed functional optical coherence tomography (OCT) system with a center wavelength of 1050 nm and an imaging speed of 100,000 A-lines per second and demonstrated imaging of the vibration of an ex-vivo swine vocal fold. High quality vocal fold images during vibration was demonstrated at an imaging speed of 100 frames per second. Functional information, such as vibration frequency and vibration amplitude, was obtained by analyzing the tissue surface during vibration. The axial direction velocity distribution ...

Vibratory measurements of the structures of the ear are key to understanding much of the pathology in mouse models of hearing loss. Unfortunately the high-speed sampling required to interrogate the high end of the mouse hearing spectrum is beyond the reach of most optical coherence tomography (OCT) systems. To address this issue, we have developed an algorithm that enables phase-sensitive OCT measurements over the full range of the mouse hearing spectrum (4–90 kHz). The algorithm phase-locks the line-trigger to the acoustic stimulation and then uses interleaved sampling to reconstruct the signal with higher temporal sampling. The algorithm was evaluated ...

Measuring the sound stimulated vibration from various structures in the organ of Corti is important in understanding how the small vibrations are amplified and detected. In this study we examine the feasibility of using phase-sensitive Fourier domain optical coherence tomography (PSFD-OCT) to measure vibration of the cellular structures of the organ of Corti. PSFD-OCT is a low coherence interferrometry system where the interferrogram is detected as a function of wavelength. The phase of the Fourier transformation of the detected spectra contains path deference (between the sample arm and the reference arm) information of the interferometer. In PSFD-OCT this phase is ...