1. Articles in category: Other Non-Medical

    1-24 of 137 1 2 3 4 5 6 »
    1. En-face full-field optical coherence tomography for fast and efficient fingerprints acquisition

      En-face full-field optical coherence tomography for fast and efficient fingerprints acquisition

      Optical coherence tomography (OCT) has been recently proposed by a number of laboratories as a promising tool for fingerprints acquisitions and for fakes discrimination. Indeed OCT being a non-contact, non-destructive optical method that virtually sections the volume of biological tissues that strongly scatter light it appears obvious to use it for fingerprints. Nevertheless most of the OCT setups have to go through the long acquisition of a full 3D image to isolate an “en-face” image suitable for fingerprint analysis. A few “en-face” OCT approaches have been proposed that use either a complex 2D scanning setup and image processing, or a ...

      Read Full Article
    2. Improved inspection and micrometrology of embedded structures in multi-layered ceramics: Development of optical coherence tomographic methods and tools (Thesis)

      Improved inspection and micrometrology of embedded structures in multi-layered ceramics: Development of optical coherence tomographic methods and tools (Thesis)

      Roll-to-roll manufacturing of micro components based on advanced printing, structuring and lamination of ceramic tapes is rapidly progressing. This large-scale and cost-effective manufacturing process of ceramic micro devices is however prone to hide defects within the visually opaque tape stacks. To achieve a sustainable manufacturing with zero defects in the future, there is an urgent need for reliable inspection systems. The systems to be developed have to perform high-resolution in-process quality control at high speed. Optical coherence tomography (OCT) is a promising technology for detailed in-depth inspection and metrology. Combined with infrared screening of larger areas it can solve the ...

      Read Full Article
    3. Growth Kinetics of Concave Nanocubes Studied by Optical Coherence Tomography

      Growth Kinetics of Concave Nanocubes Studied by Optical Coherence Tomography

      This work presents the analysis of the growth kinetics of two syntheses of concave gold nanocubes with a mean size of 72 and 108 nm followed by the optical coherence tomography (OCT) technique by acquiring B-scan images each 5 s. In addition, ultra violet-visible (UV-Vis) spectra and mean size from dynamic light scattering (DLS) were acquired during nanoparticle growth to generate kinetic plots in order to corroborate the OCT results. Kinetic plots from OCT images were obtained by plotting contrast enhancement of B-scan images as function of time. Fitting parameters values given by using the classical Kolmogorov-Johnson-Mehl-Avrami (KJMA) equation show ...

      Read Full Article
    4. Spectroscopic measurement of absorptive thin films by Spectral-Domain Optical Coherence Tomography

      Spectroscopic measurement of absorptive thin films by Spectral-Domain Optical Coherence Tomography

      A non-invasive method for measuring the refractive index, extinction coefficient and film thickness of absorptive thin films using spectral-domain optical coherent tomography is proposed, analyzed and experimentally demonstrated. Such an optical system employing a normal-incident beam of light exhibits a high spatial resolution. There are no mechanical moving parts involved for the measurement except the transversal scanning module for the measurement at various transversal locations. The method was experimentally demonstrated on two absorptive thin-film samples coated on transparent glass substrates. The refractive index and extinction coefficient spectra from 510 to 580 nm wavelength range and film thickness were simultaneously measured ...

      Read Full Article
    5. Evaluation of fingerprint deformation using optical coherence tomography

      Evaluation of fingerprint deformation using optical coherence tomography

      Biometric identification systems have important applications to privacy and security. The most widely used of these, print identification, is based on imaging patterns present in the fingers, hands and feet that are formed by the ridges, valleys and pores of the skin. Most modern print sensors acquire images of the finger when pressed against a sensor surface. Unfortunately, this pressure may result in deformations, characterized by changes in the sizes and relative distances of the print patterns, and such changes have been shown to negatively affect the performance of fingerprint identification algorithms. Optical coherence tomography (OCT) is a novel imaging ...

      Read Full Article
    6. Cost-effective optical coherence tomography spectrometer based on a tilted fiber Bragg grating

      Cost-effective optical coherence tomography spectrometer based on a tilted fiber Bragg grating

      A compact, fiber-based spectrometer for biomedical application utilizing a tilted fiber Bragg grating (TFBG) as integrated dispersive element is demonstrated. Based on a 45° UV-written PS750 TFBG a refractive spectrometer with 2.06 radiant/μm dispersion and a numerical aperture of 0.1 was set up and tested as integrated detector for an optical coherence tomography (OCT) system. Featuring a 23 mm long active region at the fiber the spectrum is projected via a cylindrical lens for vertical beam collimation and focused by an achromatic doublet onto the detector array. Covering 740 nm to 860 nm the spectrometer was optically ...

      Read Full Article
    7. Optical characterization of ultra-short Bragg grating on lithium niobate ridge waveguide

      Optical characterization of ultra-short Bragg grating on lithium niobate ridge waveguide

      In this Letter, we report a technique to etch giant aspect ratio nanostructures in lithium niobate. An 8 μm long Bragg grating on a Ti : LiNbO 3 ridge waveguide was fabricated by combining optical-grade dicing and focused ion beam milling. The reflectivity was evaluated using an optical coherence tomography system: it is measured to be 53% for the TM wave and 47% for the TE wave. We study by 2D-FDTD the modeled behavior of the electromagnetic field when an angle exists between two consecutive sidewalls of the grating in order to understand the difference between ideal Bragg grating and experimental ...

      Read Full Article
    8. Feasibility of non-invasive detection of engineered nanoparticles in food mimicking matrices by Optical Coherence Tomography

      Feasibility of non-invasive detection of engineered nanoparticles in food mimicking matrices by Optical Coherence Tomography

      The study was dedicated towards the detection of Engineered Nanoparticles (ENPs) by means ofOptical Coherence Tomography (OCT). Polymeric films were produced to mimic complex food matrices whereas gold nanorods (AuNRs) were embedded to act as ENPs. The straightforward coating application resulted in a sufficient film wetting, adhesion and homogenous AuNR distribution. Compared to food samples, these films are simpler and better defined. Such artefacts are therefore promising candidate materials for quality assurance and regulatory matters. The OCT investigations revealed a dependency of the measured signal intensity on the AuNR concentration in the film. The limit of detection for the setup ...

      Read Full Article
    9. Optical Coherence Tomography as a Characterization Method in Printed Electronics (Thesis)

      Optical Coherence Tomography as a Characterization Method in Printed Electronics (Thesis)

      This Thesis proposes and describes the use of optical coherence tomography (OCT) as a non-contact and non-destructive characterization technique for printed electronics. It is based on and includes the first published results of such an application of the OCT technique. Several different types of structures were studied to evaluate the feasibility of the application. The measurement data was used to define the surface topography, physical dimensions of the specimen features, and to evaluate the ability to characterize multi-layered and multi-material structures. Presented OCT measurements were done for: screen-printed conductive and insulating structures, microfluidic channels, microscopy glass and organic field effect ...

      Read Full Article
    10. Characterization of PET preforms using spectral domain optical coherence tomography

      Characterization of PET preforms using spectral domain optical coherence tomography

      Polyethylene terephthalate (PET) preforms are massively produced nowadays with the purpose of producing food and beverages packaging and liquid containers. Some varieties of these preforms are produced as multilayer structures, where very thin inner film(s) act as a barrier for nutrients leakage. The knowledge of the thickness of this thin inner layer is important in the production line. The quality control of preforms production requires a fast approach and normally the thickness control is performed by destructive means out of the production line. A spectral domain optical coherence tomography (SD-OCT) method was proposed to examine the thin layers in ...

      Read Full Article
    11. CAPTURING THE VITAL VASCULAR FINGERPRINT WITH OPTICAL COHERENCE TOMOGRAPHY

      CAPTURING THE VITAL VASCULAR FINGERPRINT WITH OPTICAL COHERENCE TOMOGRAPHY

      Using fingerprints as a method to identify an individual has been accepted in forensics since the 19 th century, and the fingerprint has become one of the most widely used biometric characteristics. Most of the modern fingerprint recognition systems are based on the print pattern of the finger surface and are not robust against spoof attaching. There may be problems where there are scars or cuts on fingertips. Optical coherence tomography (OCT) is a noncontact imaging technique which can capture high resolution, 3D images from within highly scattering biological tissues. There has been great interest to use OCT for fingerprint ...

      Read Full Article
    12. Volume Determination of Fresh and Dried Bloodstains by Means of Optical Coherence Tomography

      Volume Determination of Fresh and Dried Bloodstains by Means of Optical Coherence Tomography

      The volume of bloodstains found on crime scenes may help forensic investigators reconstruct the location and kinematics of bloodletting events, as stain size, volume, and impact velocity are related. Optical coherence tomography was used as a method to determine the volume and volume ratio of dried and fresh bloodstains on both glass and irregular surfaces or deposited with an impact velocity. The volume of blood drops deposited on smooth glass surfaces was measured within a deviation of 2%. This deviation increased for droplets on irregular surfaces or deposited with an impact velocity. The volume ratio of dried and fresh bloodstains ...

      Read Full Article
    13. Highly accurate measurement of lens surface distances within optical assemblies for quality testing

      Highly accurate measurement of lens surface distances within optical assemblies for quality testing

      In the assembly of multi-component optical systems the precise positioning of every single lens element respectively lens surface is key to reach an optical performance that corresponds to the optical design. Here, in addition to lateral decentering of single elements – such as shift and tilt – the accurate positioning of the optical surfaces along the optical axis is an essential requirement. In this contribution we present the highly accurate determination of lens center thicknesses and air gaps of optical assemblies in a non-contact manner. The measurement technique is based on time-domain low coherent interferometry (also known as A-scan optical coherence tomography ...

      Read Full Article
    14. Pearl Thickness Measurements from Optical Coherence Tomography Images

      Pearl Thickness Measurements from Optical Coherence Tomography Images

      By measuring the thickness of the nacreous layer, pearl optical coherence tomography (OCT) images are now increasingly used in identification and characterization. An approach to automated thickness measurement of pearl OCT image has been reported in this paper. A Total Variational (TV) Model filter has been used to remove noise in images. After the image filtering, edges are detected by self-adaptive Canny operator. In the end we used circle fitting technologies to archive the goal of automated thickness measurement. The experimental results show this approach is accurate and adaptable.

      Read Full Article
    15. Imaging of the interaction of low-frequency electric fields with biological tissues by optical coherence tomography

      Imaging of the interaction of low-frequency electric fields with biological tissues by optical coherence tomography

      Low-frequency electric fields propagating in ex vivo biological tissues have been observed by using double-correlation optical coherence tomography (OCT). An adaptive Wiener filtering approach has been used to remove background noise, and a Fourier domain correlation algorithm has been applied to the sequence of OCT images. The results present the first direct observation (to our knowledge) of the scope of the electric field influencing biological tissues with OCT. The results show that variation in voltage and frequency of the applied electric field relates exponentially to the magnitude of its influence on biological tissue. The magnitude of influence is about twice ...

      Read Full Article
    16. Capturing the vital vascular fingerprint with optical coherence tomography

      Capturing the vital vascular fingerprint with optical coherence tomography

      Using fingerprints as a method to identify an individual has been accepted in forensics since the nineteenth century, and the fingerprint has become one of the most widely used biometric characteristics. Most of the modern fingerprint recognition systems are based on the print pattern of the finger surface and are not robust against spoof attaching. We demonstrate a novel vital vascular fingerprint system using Doppler optical coherence tomography that provides highly sensitive and reliable personal identification. Because the system is based on blood flow, which only exists in a livng person, the technique is robust against spoof attaching.

      Read Full Article
    17. Wafer alignment system with optical coherence tomography

      Wafer alignment system with optical coherence tomography

      A system for performing alignment of two wafers is disclosed. The system comprises an optical coherence tomography system and a wafer alignment system. The wafer alignment system is configured and disposed to control the relative position of a first wafer and a second wafer. The optical coherence tomography system is configured and disposed to compute coordinate data for a plurality of alignment marks on the first wafer and second wafer, and send that coordinate data to the wafer alignment system

      Read Full Article
    18. Optical coherence tomography as a reference method for the detection of nanoparticles in thin-film polymer matrices

      Optical coherence tomography as a reference method for the detection of nanoparticles in thin-film polymer matrices

      In food and feed production an emerging issue is the use of nanoparticles as additives to control specific properties of the products. In this context, one focus in food chemistry is the development and evaluation of measurement techniques, which could allow the detection and quantification of nanoparticles in food products. For this purpose, special noninvasive and non-destructive reference methods are required, which allow subsequent analysis with other measurement techniques. Additionally, non-invasive and fast imaging techniques are potentially appropriate for applications in the food production. Optical coherence tomography is sensitive to the backscattering of particles and is regarded as a promising ...

      Read Full Article
    19. Elimination of honeycomb patterns in fiber bundle imaging by a superimposition method

      Elimination of honeycomb patterns in fiber bundle imaging by a superimposition method

      A superimposition method for alleviating the characteristic artifact structure of an imaging fiber bundle is demonstrated. This method can reduce the inherent honeycomb patterns of fiber bundle images and restore hidden information by using pixelated images captured from neighboring locations. The pixelation effect is suppressed when multiple adjacent images, with centers separated by one core radius and arranged in a square pattern, are superimposed for summation. The restored image has preserved edge sharpness in cellular and vascular structure boundaries, compared to the reference image without pixelation and identical imaging modality, as found by optical coherence tomography.

      Read Full Article
      Mentions: Korea University
    20. Optical coherence tomography biospeckle imaging for fast monitoring varying surface responses of a plant leaf under ozone stress

      Optical coherence tomography biospeckle imaging for fast monitoring varying surface responses of a plant leaf under ozone stress

      In this study, Optical Coherence Tomography (OCT) was used to investigate the effect of short term ozone exposure on both front and back surfaces of the leaves of Allium tuberosum plant. Plant leaves were subjected to treat with 240ppb level of ozone, and imaging data were acquired from back and front surfaces of the leaves. Variations of the biological activations were monitored based on the biospeckles. Standard deviations (SD) of OCT temporal signal at each point were calculated and used to visualize the effect of ozone exposure. Leaf back surface showed higher SDs in biospeckle OCT signal in comparison to ...

      Read Full Article
    21. Feature Of The Week 5/19/13: Using Optical Coherence Tomography For Anti-Spoof Fingerprint Detection

      Feature Of The Week 5/19/13: Using Optical Coherence Tomography For Anti-Spoof Fingerprint Detection

      Fingerprint biometrics, including automated fingerprint identification systems (AFIS), currently occupy two-thirds of the biometric market and are expected to remain the dominant player in this area. The technology can be integrated into small, compact devices and the instruments are relatively fast. However, the overall success of using fingerprints for identification and verification purposes greatly depends upon the quality of the fingerprints initially enrolled. For example, fingerprints captured from older people are significantly lower quality than those from younger people due primarily to ridge-wearing and difficulty of interacting effectively with conventional fingerprint scanners. The ramification is that the problem of obtaining ...

      Read Full Article
    22. Accurate prediction of collapse temperature using optical coherence tomography-based freeze-drying microscopy

      Accurate prediction of collapse temperature using optical coherence tomography-based freeze-drying microscopy

      The objective of this study was to assess the feasibility of developing and applying a laboratory tool that can provide three-dimensional product structural information during freeze-drying and which can accurately characterize the collapse temperature ( T c ) of pharmaceutical formulations designed for freeze-drying. A single-vial freeze dryer coupled with optical coherence tomography freeze-drying microscopy (OCT–FDM) was developed to investigate the structure and T c of formulations in pharmaceutically relevant products containers (i.e., freeze-drying in vials). OCT–FDM was used to measure the T c and eutectic melt of three formulations in freeze-drying vials. The T c as measured by ...

      Read Full Article
    23. Optical coherence tomography for vulnerability assessment of sandstone

      Optical coherence tomography for vulnerability assessment of sandstone

      Sandstone is an important cultural heritage material, in both architectural and natural settings, such as neolithic rock art panels. The majority of deterioration effects in porous materials such as sandstone are influenced by the presence and movement of water through the material. The presence of water within the porous network of a material results in changes in the optical coherence tomography signal intensity that can be used to monitor the wetting front of water penetration of dry porous materials at various depths. The technique is able to detect wetting front velocities from 1     cm     s − 1 to 10 − 6     cm ...

      Read Full Article
    1-24 of 137 1 2 3 4 5 6 »
  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