Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Reverse transduction measured in the living cochlea by low-coherence heterodyne interferometry.

ABSTRACT: It is generally believed that the remarkable sensitivity and frequency selectivity of mammalian hearing depend on outer hair cell-generated force, which amplifies sound-induced vibrations inside the cochlea. This 'reverse transduction' force production has never been demonstrated experimentally, however, in the living ear. Here by directly measuring microstructure vibrations inside the cochlear partition using a custom-built interferometer, we demonstrate that electrical stimulation can evoke both fast broadband and slow sharply tuned responses of the reticular lamina, but only a slow tuned response of the basilar membrane. Our results indicate that outer hair cells can generate sufficient force to drive the reticular lamina over all audible frequencies in living cochleae. Contrary to expectations, the cellular force causes a travelling wave rather than an immediate local vibration of the basilar membrane; this travelling wave vibrates in phase with the reticular lamina at the best frequency, and results in maximal vibration at the apical ends of outer hair cells.

SUBMITTER: Ren T

PROVIDER: S-EPMC4729828 | biostudies-other | 2016 Jan

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Focus Tracking System for Femtosecond Laser Machining using Low Coherence Interferometry.

Project description:We designed a real time, single-laser focus tracking system using low coherence properties of the machining femtosecond laser itself in order to monitor and correct the sample position relative to the focal plane. Using a Michelson Interferometer, the system collects data arising from part of the beam backscattered at the ablation spot. The data is analyzed by a custom software for position correction (employing an XYZ automated translation stage). With the focus tracking enabled we were able to etch channels with a stable cross-section profile on a bovine tooth with relief amplitude tens of times greater than the Rayleigh length of the system, keeping the sample inside the confocal parameter during most of the processing time. Moreover, the system is also capable of monitoring crater depth evolution during the ablation process, allowing for material removal assessment.

| S-EPMC6414527 | biostudies-literature

Angle-resolved low coherence interferometry for detection of dysplasia in Barrett's esophagus.

Project description: Not available

| S-EPMC3152604 | biostudies-literature

Two-color heterodyne laser interferometry for long-distance stage measurement with correction of uncertainties in measured optical distances.

Project description:We designed a new system that eliminates deviations by correcting uncertainty in optical distance measurements in the laser two-color heterodyne interferometer. In simulations, eliminating the uncertainty from the atmosphere, the deviation in the uncertainty of the optical distance was 50 times greater with the two-color method than with the one-color method. Adding a correction arm reduces the deviation caused by the uncertainties in measured optical distances. The uncertainty in the measured path length is reduced to 20 nm over a path length of 1500 mm, giving a relative uncertainty of 1.34 × 10 -8.

| S-EPMC5558020 | biostudies-other

Complex conjugate resolved heterodyne swept source optical coherence tomography using coherence revival.

Project description:We describe a simple and low-cost technique for resolving the complex conjugate ambiguity in Fourier domain optical coherence tomography (OCT) that is applicable to many swept source OCT (SSOCT) systems. First, we review the principles of coherence revival, wherein an interferometer illuminated by an external cavity tunable laser (ECTL) exhibits interference fringes when the two arms of the interferometer are mismatched by an integer multiple of the laser cavity length. Second, we report observations that the spectral interferogram obtained from SSOCT systems employing certain ECTLs are automatically phase modulated when the arm lengths are mismatched this way. This phase modulation results in a frequency-shifted interferogram, effectively creating an extended-depth heterodyne SSOCT system without the use of acousto-optic or electro-optic modulators. We suggest that this phase modulation may be caused by the ECTL cavity optical pathlength varying slightly over the laser sweep, and support this hypothesis with numerical simulations. We also report on the successful implementation of this technique with two commercial swept source lasers operating at 840nm and 1040nm, with sweep rates of 8kHz and 100kHz respectively. The extended imaging depth afforded by this technique was demonstrated by measuring the sensitivity fall-off profiles of each laser with matched and mismatched interferometer arms. The feasibility of this technique for clinical systems is demonstrated by imaging the ocular anterior segments of healthy human volunteers.

| S-EPMC3296548 | biostudies-literature

Comparison study of the axial length measured using the new swept-source optical coherence tomography ANTERION and the partial coherence interferometry IOL Master.

Project description:PurposeTo compare a biometer using swept-source optical coherence tomography (SS-OCT) with a partial coherence interferometry (PCI)-based biometer in measurements of two ocular biometry parameters, i.e., the axial length and anterior cornea curvature.MethodsWe compared the two biometers SS-OCT (ANTERION, Heidelberg Engineering Inc., Heidelberg, Germany) and PCI (IOL Master, Carl Zeiss Meditec, Jena, Germany) in terms of the axial length (AL) and corneal curvature (K) measurements of 175 eyes. Paired t-tests were used to compare the two biometers. Agreement between the biometers was evaluated using the Bland-Altman method.ResultsThe mean age was 36.0 ± 25.6 years (range: 5 to 85 years). The mean axial length was 24.42 ± 0.13 mm for SS-OCT and 24.45 ± 0.14 mm for PCI. The mean corneal curvature was significantly different between the two biometry in flat K (K1) but not in steep K (K2). The limit of agreement was -0.15 to 0.21 in the axial length, -1.18 to 0.83 in K1, and -1.06 to 0.95 in K2. All above ocular biometric measurements between SS-OCT and PCI correlated significantly (Pearson's correlation, p<0.001).ConclusionsThe axial length measured using SS-OCT is useful in clinical practice. It shows a good correlation and agreement with that measured using PCI. However, the axial length and corneal curvature measured using SS-OCT cannot be used interchangeably with that measured using PCI in clinical practice.

| S-EPMC7775111 | biostudies-literature

Depth-resolved dual-beamlet vibrometry based on Fourier domain low coherence interferometry.

Project description:We present an optical vibrometer based on delay-encoded, dual-beamlet phase-sensitive Fourier domain interferometric system to provide depth-resolved subnanometer scale vibration information from scattering biological specimens. System characterization, calibration, and preliminary vibrometry with biological specimens were performed. The proposed system has the potential to provide both amplitude and direction of vibration of tissue microstructures on a single two-dimensional plane.

| S-EPMC3584824 | biostudies-other

Micro-optical coherence tomography of the mammalian cochlea.

Project description: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 inner ears were imaged as whole temporal bones with cochlea in situ. Anatomical structures such as the tunnel of Corti, space of Nuel, modiolus, scalae, and cell groupings were visualized, in addition to individual cell types such as neuronal fibers, hair cells, and supporting cells. Visualization of these structures, via volumetrically-reconstructed image stacks and endoscopic perspective videos, represents an improvement over previous efforts using conventional OCT. These are the first μOCT images of mammalian cochlear anatomy, and they demonstrate μOCT's potential utility as an imaging tool in otology research.

| S-EPMC5025881 | biostudies-literature

Non-contact characterization of compound optical elements using reflectance confocal microscopy, low-coherence interferometry, and computational ray-tracing.

Project description:Advances in microscopy have enabled us to see at unprecedented depths and resolutions, even breaking the diffraction-limit by several fold. These improvements have come at the expense of system complexity with microscopes routinely employing multiple objective lenses and custom optical relays. Optimal system design is paramount for imaging performance, but research systems are limited by the use of commercial components because optical prescriptions are often inaccessible. System performance can be further degraded when these components are implemented in nonstandard configurations outside of manufacturer specifications. Here, we describe a method for characterization of compound optical elements including curvatures, material and air-gap thicknesses, and glass types. We present validation data for doublets and a commercial broadband scan lens. Our method is both non-contact and non-destructive, and we believe it addresses a unique gap in optical design that may be extended to broad applications in both research and industrial manufacturing.

| S-EPMC6864052 | biostudies-literature

Feasibility of clinical detection of cervical dysplasia using angle-resolved low coherence interferometry measurements of depth-resolved nuclear morphology.

Project description:This study sought to establish the feasibility of using in situ depth-resolved nuclear morphology measurements for detection of cervical dysplasia. Forty enrolled patients received routine cervical colposcopy with angle-resolved low coherence interferometry (a/LCI) measurements of nuclear morphology. a/LCI scans from 63 tissue sites were compared to histopathological analysis of co-registered biopsy specimens which were classified as benign, low-grade squamous intraepithelial lesion (LSIL), or high-grade squamous intraepithelial lesion (HSIL). Results were dichotomized as dysplastic (LSIL/HSIL) versus non-dysplastic and HSIL versus LSIL/benign to determine both accuracy and potential clinical utility of a/LCI nuclear morphology measurements. Analysis of a/LCI data was conducted using both traditional Mie theory based processing and a new hybrid algorithm that provides improved processing speed to ascertain the feasibility of real-time measurements. Analysis of depth-resolved nuclear morphology data revealed a/LCI was able to detect a significant increase in the nuclear diameter at the depth bin containing the basal layer of the epithelium for dysplastic versus non-dysplastic and HSIL versus LSIL/Benign biopsy sites (both p?<?0.001). Both processing techniques resulted in high sensitivity and specificity (>0.80) in identifying dysplastic biopsies and HSIL. The hybrid algorithm demonstrated a threefold decrease in processing time at a slight cost in classification accuracy. The results demonstrate the feasibility of using a/LCI as an adjunctive clinical tool for detecting cervical dysplasia and guiding the identification of optimal biopsy sites. The faster speed from the hybrid algorithm offers a promising approach for real-time clinical analysis.

| S-EPMC5512428 | biostudies-literature

Predictive accuracy of partial coherence interferometry and swept-source optical coherence tomography for intraocular lens power calculation.

Project description:The purpose of this study is to compare the predictive accuracy of intraocular lens (IOL) calculations made with partial coherence interferometry (PCI, IOLMaster, version 5) and swept-source optical coherence tomography (SS-OCT, Argos). Axial length (AL), mean keratometry value (K), and anterior chamber depth (ACD) were obtained using PCI and SS-OCT optical biometers. Intraocular lens (IOL) power calculations were made using the Barret-Universal II, Haigis, Hoffer Q, SRK/T, and T2 formulas and compared the predictive accuracy between biometers. In 153 eyes (153 patients), axial length measurements made with PCI (24.65?±?2.35?mm) and SS-OCT (24.62?±?2.29?mm) were significantly different (P?<?0.001). Corneal power (P?=?0.97) and anterior chamber depth (P?=?0.51) were not significantly different between biometer. The mean absolute error was not significantly different between the five IOL power calculation formulas for either PCI or SS-OCT measurements. When AL was 24.5-26.0?mm, mean absolute error derived from SS-OCT was smaller than mean absolute error derived from PCI for all five IOL power calculation formulas (all P?<?0.05). In conclusion, predictive accuracy of PCI and SS-OCT were nearly the same. However, in medium-long eyes, the predictive accuracy of SS-OCT for IOL calculations was higher.

| S-EPMC6137182 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data