Microscopy -Optical Coherence Tomography News

Articles in category: Microscopy

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1. Cornea characterization using a combined multiphoton microscopy and optical coherence tomography system
  
  Explore opticsinfobase.org Apr 14 2014 Microscopy , Ophthalmology
  
  We present a multimodal imaging system which combines multiphoton microscopy and optical coherence tomography to visualize the morphological structures, and to quantify the refractive index (RI) and thickness of cornea. The morphological similarities and differences at different corneal layers across various species are identified. In the piscine and human corneas, the stromata exhibit thin fibers that indicate an overall collagen direction. Human corneas display collagen micro-folds which cause increased light attenuation. In the murine, porcine and bovine corneas, the stromata show interwoven collagen patterns. The Bowman’s layer and the Descemet’s membrane are also distinguished in some species. The ...
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  Mentions: University of British Columbia
2. Label-free cell-based assay with spectral-domain optical coherence phase microscopy
  
  Explore SPIE | Journal Apr 12 2014 Microscopy
  
  Quantitative measurement of dynamic responses of unstained living cells is of great importance in many applications ranging from investigation of fundamental cellular functions to drug discoveries. Conventional optical methods for label-free cell-based assay examine cellular structural changes proximal to sensor surfaces under external stimuli, but require dedicated nanostructure-patterned substrates for operation. Here, we present a quantitative imaging method, spectral-domain optical coherence phase microscopy (SD-OCPM), as a viable optical platform for label-free cell-based assay. The instrument is based on a low-coherence interferometric microscope that enables quantitative depth-resolved phase measurement of a transparent specimen with high phase stability. We demonstrate SD-OCPM measurement ...
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  Mentions: Yonsei University Chulmin Joo
3. In vivo imaging of middle-ear and inner-ear microstructures of a mouse guided by SD-OCT combined with a surgical microscope
  
  Explore opticsinfobase.org Apr 7 2014 Microscopy , Otolaryngology
  
  We developed an augmented-reality system that combines optical coherence tomography (OCT) with a surgical microscope. By sharing the common optical path in the microscope and OCT, we could simultaneously acquire OCT and microscope views. The system was tested to identify the middle-ear and inner-ear microstructures of a mouse. Considering the probability of clinical application including otorhinolaryngology, diseases such as middle-ear effusion were visualized using in vivo mouse and OCT images simultaneously acquired through the eyepiece of the surgical microscope during surgical manipulation using the proposed system. This system is expected to realize a new practical area of OCT application.
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  Mentions: Jeehyun Kim Kyungpook National University
4. Low coherence interferometric second harmonic generation microscopy for non-destructive material testing using a broadband 1550 nm fs-fiber laser
  
  Explore IOPscience Mar 31 2014 Microscopy , NDE/NDT
  
  In this paper low coherence interferometric second harmonic generation (SHG) imaging is successfully demonstrated using a compact broadband fs-fiber laser operating around 1550 nm. In combination with linear optical coherence microscopy, this SHG technique is tailored for structural and functional investigations of surfaces and subsurface regions of non-biological samples, like corrosion sites formed on metals below organic coatings.
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  Mentions: David Stifter Johannes Kepler University of Linz
5. Simultaneous detection of optical retardation and axis orientation by polarization-sensitive full-field optical coherence microscopy for material testing
  
  Explore IOPscience Mar 31 2014 Microscopy , NDE/NDT
  
  We present a polarization-sensitive full-field optical coherence microscopy modality which is capable of simultaneously delivering depth resolved information on the reflectivity, optical retardation and optical axis orientation. In this way local birefringence, inherent stress–strain fields and optical anisotropies can be visualized with high resolution, as exemplified for various technical material applications.
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  Mentions: David Stifter Bettina Heise Stefan E. Schausberger
6. Label-free evaluation of angiogenic sprouting in microengineered devices using ultrahigh-resolution optical coherence microscopy
  
  Explore SPIE | Journal Jan 11 2014 Microscopy
  
  Understanding the mechanism of angiogenesis could help to decipher wound healing and embryonic development and to develop better treatment for diseases such as cancer. Microengineered devices were developed to reveal the mechanisms of angiogenesis, but monitoring the angiogenic process nondestructively in these devices is a challenge. In this study, we utilized a label-free imaging technique, ultrahigh-resolution optical coherence microscopy (OCM), to evaluate angiogenic sprouting in a microengineered device. The OCM system was capable of providing ∼ 1.5 - μ m axial resolution and ∼ 2.3 - μ m transverse resolution. Three-dimensional (3-D) distribution of the sprouting vessels in the microengineered device was imaged over ...
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  Mentions: Lehigh University University of Pennsylvania Harvard University
7. Quantitative cerebral blood flow imaging with extended-focus optical coherence microscopy
  
  Explore opticsinfobase.org Dec 16 2013 Microscopy
  
  Quantitative three-dimensional blood flow imaging is a valuable technique to investigate the physiology of the brain. Two-photon microscopy (2PM) allows quantification of the local blood flow velocity with micrometric resolution by performing repeated line scans, but prohibitively long measurement times would be required to apply this technique to full three-dimensional volumes. By multiplexing the image acquisition over depth, Fourier domain optical coherence tomography (FDOCT) enables quantification of blood flow velocities with a high volume acquisition rate, albeit at a relatively low spatial resolution. Extended-focus optical coherence microscopy (xfOCM) increases the lateral resolution without sacrificing depth of field and therefore combines ...
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  Mentions: Ecole Polytechnique Fédérale de Lausanne Daniel Szlag Theo Lasser
8. LLTech and Research Partners win a 800K€ grant for FF-OCT NOCT project
  
  Explore Optical Coherence Tomography News Nov 5 2013 Microscopy
  
  NOCT program is research program who is awarded a 800K€ grant from the ANR (Agence Nationale de la Recherche). The target is to develop a 3D guided needle endoscope system. LLTech collaborates with Institut Langevin, SurgiQual Institute, Université Joseph Fourier and Centre Hospitalier de Grenoble. The current biopsy procedure is to introduce a needle inside the patient towards a given target using echography imaging for control of the position. Reaching the target at the right position is a real issue for diagnosis, therapy and also prognosis, for example concerning tumors or abscess. The NOCT project aims at developing two apparatus ...
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  Mentions: LLTech Bertrand de Poly LLTech Light-CT Scanner
9. Full-field optical coherence tomography for the analysis of fresh unstained human lobectomy specimens
  
  Explore Journal of Pathology Informatics Nov 4 2013 Microscopy , Pulmonology
  
  Full-field optical coherence tomography (FFOCT) is a real-time imaging technique that generates high-resolution three-dimensional tomographic images from unprocessed and unstained tissues. Lack of tissue processing and associated artifacts, along with the ability to generate large-field images quickly, warrants its exploration as an alternative diagnostic tool. Materials and Methods: One section each from the tumor and from adjacent non-neoplastic tissue was collected from 13 human lobectomy specimens. They were imaged fresh with FFOCT and then submitted for routine histopathology. Two blinded pathologists independently rendered diagnoses based on FFOCT images. Results: Normal lung architecture (alveoli, bronchi, pleura and blood vessels) was readily ...
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  Mentions: Cornell University Claude Boccara LLTech
10. Methods, systems, and computer readable media for synthetic wavelength-based phase unwrapping in optical coherence tomography and spectral domain phase microscopy
  
  Explore uspto.gov Oct 22 2013 Microscopy , Patents
  
  In accordance with this disclosure, methods, systems, and computer readable media for synthetic wavelength-based phase unwrapping in optical coherence tomography are provided. Synthetic wavelength phase unwrapping can be applied to OCT data and can correctly resolve sample motions that are larger than .lamda..sub.o/2. A method for phase unwrapping of an OCT signal can include acquiring raw OCT signal data, interpolating and processing the OCT signal data to obtain a DC spectrum, comparing the raw OCT signal data to the DC spectrum to generate an interference signal, applying Gaussian windows to the interference signal to generate a two ...
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  Mentions: Joseph A. Izatt Duke University Mingtao Zhao
11. Three-dimensional optical coherence tomography confocal imaging apparatus
  
  Explore uspto.gov Oct 8 2013 Microscopy , Patents
  
  A 3D OCT confocal imaging apparatus includes a light source module for providing an illumination beam with wider bandwidth from a crystal fiber; a reference source module; a pickup module; a beam splitter; an optical filter; and a sensor module. When the illumination beam illuminates a sample, a pickup objective lens and a piezoelectric actuator of the pickup module together provide an image beam scanning the sample in depth direction. The image beam and a reference beam from the reference source module together form an interference image beam, which is converted by a photosensor into a coherence image electric signal ...
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  Mentions: National Taiwan University Sheng-Lung Huang Chien-Chung Tsai
12. Common detector for combined raman spectroscopy-optical coherence tomography
  
  Explore uspto.gov Oct 8 2013 Microscopy , Patents
  
  An apparatus includes first and second light sources for respectively generating broadband and monochromatic lights, a beamsplitter optically coupled to the first light source for splitting the broadband light into a reference light and a sample light, a reference arm optically coupled to the beamsplitter for receiving the reference light and returning the received reference light into the beamsplitter, a sample arm optically coupled to the beamsplitter and the second light source for combining the sample and monochromatic lights, delivering the combined light to the target of interest, collecting a backscattering light and a Raman scattering light generated from interaction ...
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  Mentions: Vanderbilt University Academic Medical Center at the University of Amsterdam Jeroen Kalkman
13. Volumetric imaging and quantification of cytoarchitecture and myeloarchitecture with intrinsic scattering contrast
  
  Explore opticsinfobase.org Sep 15 2013 Microscopy
  
  We present volumetric imaging and computational techniques to quantify neuronal and myelin architecture with intrinsic scattering contrast. Using spectral / Fourier domain Optical Coherence Microscopy (OCM) and software focus-tracking we validate imaging of neuronal cytoarchitecture and demonstrate quantification in the rodent cortex in vivo . Additionally, by ex vivo imaging in conjunction with optical clearing techniques, we demonstrate that intrinsic scattering contrast is preserved in the brain, even after sacrifice and fixation. We volumetrically image cytoarchitecture and myeloarchitecture ex vivo across the entire depth of the rodent cortex. Cellular-level imaging up to the working distance of our objective (~3 mm) is demonstrated ...
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  Mentions: Vivek J. Srinivasan UC Davis Harsha Radhakrishnan
14. Dark-field circular depolarization optical coherence microscopy
  
  Explore opticsinfobase.org Aug 24 2013 Microscopy
  
  Optical coherence microscopy (OCM) is a widely used structural imaging modality. To extend its application in molecular imaging, gold nanorods are widely used as contrast agents for OCM. However, they very often offer limited sensitivity as a result of poor signal to background ratio. Here we experimentally demonstrate that a novel OCM implementation based on dark-field circular depolarization detection can efficiently detect circularly depolarized signal from gold nanorods and at the same time efficiently suppress the background signals. This results into a significant improvement in signal to background ratio.
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  Mentions: National University of Singapore
15. Tri-modal microscopy with multiphoton and optical coherence microscopy/tomography for multi-scale and multi-contrast imaging
  
  Explore opticsinfobase.org Aug 8 2013 Microscopy
  
  Multi-scale multimodal microscopy is a very useful technique by providing multiple imaging contrasts with adjustable field of views and spatial resolutions. Here, we present a tri-modal microscope combining multiphoton microscopy (MPM), optical coherence microscopy (OCM) and optical coherence tomography (OCT) for subsurface visualization of biological tissues. The advantages of the tri-modal system are demonstrated on various biological samples. It enables the visualization of multiple intrinsic contrasts including scattering, two-photon excitation fluorescence (TPEF), and second harmonic generation (SHG). It also enables a rapid scanning over a large tissue area and a high resolution zoom-in for cellular-level structures on regions of interest ...
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  Mentions: University of British Columbia
16. Quantitative lateral and axial flow imaging with optical coherence microscopy and tomography
  
  Explore opticsinfobase.org Aug 5 2013 Microscopy , Velocimetry
  
  Optical coherence tomography (OCT) and optical coherence microscopy (OCM) allow the acquisition of quantitative three-dimensional axial flow by estimating the Doppler shift caused by moving scatterers. Measuring the velocity of red blood cells is currently the principal application of these methods. In many biological tissues, blood flow is often perpendicular to the optical axis, creating the need for a quantitative measurement of lateral flow. Previous work has shown that lateral flow can be measured from the Doppler bandwidth, albeit only for simplified optical systems. In this work, we present a generalized model to analyze the influence of relevant OCT/OCM ...
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  Mentions: Maciej Wojtkowski Nicolaus Copernicus University Ecole Polytechnique Fédérale de Lausanne
17. Swept source optical coherence microscopy using a 1310 nm VCSEL light source
  
  Explore opticsinfobase.org Jul 22 2013 Microscopy
  
  We demonstrate high speed, swept source optical coherence microscopy (OCM) using a MEMS tunable vertical cavity surface-emitting laser (VCSEL) light source. The light source had a sweep rate of 280 kHz, providing a bidirectional axial scan rate of 560 kHz. The sweep bandwidth was 117 nm centered at 1310 nm, corresponding to an axial resolution of 13.1 µm in air, corresponding to 8.1 µm (9.6 µm spectrally shaped) in tissue. Dispersion mismatch from different objectives was compensated numerically, enabling magnification and field of view to be easily changed. OCM images were acquired with transverse resolutions between 0 ...
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  Mentions: Massachusetts Institute of Technology James G. Fujimoto Thorlabs
18. Control of focusing in high resolution eye imaging and microscopy using a deformable mirror
  
  Explore Conference Proceedings Jun 23 2013 Microscopy , Ophthalmology
  
  We use a deformable mirror (DM) in an adaptive optics dual channel optical coherence tomography/en-face eye fundus setup to control focus on the sample by adding aberrations to the wavefront. A program was created to sweep the equivalent focus created by the DM. Using this device we are able to sweep the focus between two extremes. This system is also used to measure and monitor any existing aberrations in the system, caused by the optical elements or the target object.
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  Mentions: Adrian G. Podoleanu University of Kent John A. Rogers
19. Full-field optical coherence tomography using immersion Mirau interference microscope
  
  Explore opticsinfobase.org Jun 18 2013 Microscopy
  
  In this study, an immersion Mirau interference microscope was developed for full-field optical coherence tomography (FFOCT). Both the reference and measuring arms of the Mirau interferometer were filled with water to prevent the problems associated with imaging a sample in air with conventional FFOCT systems. The almost-common path interferometer makes the tomographic system less sensitive to environmental disturbances. En face OCT images at various depths were obtained with phase-shifting interferometry and Hariharan algorithm. This immersion interferometric method improves depth and quality in three-dimensional OCT imaging of scattering tissue.
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20. Microscope For Monitoring Optical Coherence Tomography
  
  Explore patentscope.wipo.int Jun 1 2013 Microscopy , Patents
  
  The present invention relates to a microscope for monitoring optical coherence tomography. The microscope includes: a microscope image providing part in which a first object lens, a beam splitter, and an ocular lens are successively disposed from the front surface of a sample support; and an OCT image providing part providing an optical coherent tomography image into the beam splitter of the microscope image providing part after the optical coherent tomography image is generated. The OCT image providing part generates an OCT image having the same position as that of the surface image of a sample to provide the OCT ...
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  Mentions: Kyungpook National University
21. Portable Optical Coherence Tomography (OCT) Systems
  
  Explore patentscope.wipo.int May 17 2013 Microscopy , Patents
  
  Portable optical coherence tomography (OCT) devices including at least one mirror configured to scan at least two directions are provided. The portable OCT devices are configured to provide a portable interface to a sample that can be aligned to the sample without repositioning the sample. Related systems are also provided.
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  Mentions: Joseph A. Izatt Eric L. Buckland Bioptigen
22. High-resolution corneal topography and tomography of fish eye using wide-field white light interference microscopy
  
  Explore Linking to Scitation Content Apr 26 2013 Microscopy , Ophthalmology
  
  Topography and tomography of fish cornea is reconstructed using high resolution white light interference microscopy. White light interferograms at different depths were recorded by moving the object axially. For each depth position, five phase shifted interferograms were recorded and analyzed. From the reconstructed phase maps, the corneal topography and hence the refractive index was determined and from amplitude images the cross-sectional image of fish cornea was reconstructed. In the present method, we utilize a nearly common-path interference microscope and wide field illumination and hence do not require any mechanical B-scan. Therefore, the phase stability of the recorded data is improved.
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  Mentions: Dalip Singh Mehta Indian Institute of Technology at Delhi
23. Method And Apparatus For Optical Imaging Via Spectral Encoding
  
  Explore patentscope.wipo.int Apr 26 2013 Microscopy , Patents
  
  Exemplary method, apparatus and arrangement can be provided for obtaining information associated with a sample such as a portion of an anatomical structure. The information can be generated using first data, which can be based on a signal obtained from a location on the sample, and second data, where the second data can be obtained by combining a second signal received from the sample with a third reference signal. An image of a portion of the sample can also be generated based on the information. For example, the first data can be associated with spectral encoding microscopy data, and the ...
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  Mentions: Guillermo J. Tearney Brett E. Bouma Massachusetts General Hospital
24. Optical probe design with extended depth-of-focus for optical coherence microscopy and optical coherence tomography
  
  Explore Conference Proceedings Mar 18 2013 Microscopy
  
  In this report, Optical probe system for modality, optical coherence tomography (OCT) and optical coherence microscope (OCM), is presented. In order to control the back focal length from 2.2 mm to 27 mm, optical probe is designed using two liquid lenses and several lenses. The narrow depth of focus (DOF) in microscope is extended by phase filter such as cubic filter. The filter is modified so that DOF is extended only In the OCM mode. The section for the extended DOF of probe is controlled by iris. Therefore in OCT mode, the phase filter does not affect on the ...
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