1. Articles in category: Microscopy

    1-24 of 342 1 2 3 4 ... 13 14 15 »
    1. High-resolution corneal topography and tomography of fish eye using wide-field white light interference microscopy

      High-resolution corneal topography and tomography of fish eye using wide-field white light interference microscopy

      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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    2. Method And Apparatus For Optical Imaging Via Spectral Encoding

      Method And Apparatus For Optical Imaging Via Spectral Encoding

      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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    3. Optical probe design with extended depth-of-focus for optical coherence microscopy and optical coherence tomography

      Optical probe design with extended depth-of-focus for optical coherence microscopy and optical coherence tomography

      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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    4. Imaging of non tumorous and tumorous human brain tissue with full-field optical coherence tomography

      Imaging of non tumorous and tumorous human brain tissue with full-field optical coherence tomography

      A prospective study was performed on neurosurgical samples from 18 patients to evaluate the use of Full-Field Optical Coherence Tomography (FF-OCT) in brain tumor diagnosis. FF-OCT captures en face slices of tissue samples at 1μm resolution in 3D with a typical 200μm imaging depth. A 1cm² specimen is scanned at a single depth and processed in about 5 minutes. This rapid imaging process is non-invasive and requires neither contrast agent injection nor tissue preparation, 30 which makes it particularly well suited to medical imaging applications. Temporal chronic epileptic parenchyma and brain tumors such as meningiomas, lowgrade and high-grade ...

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    5. Miniature probe combining optical-resolution photoacoustic microscopy and optical coherence tomography for in vivomicrocirculation study

      Miniature probe combining optical-resolution photoacoustic microscopy and optical coherence tomography for in vivomicrocirculation study

      Photoacoustic microscopy (PAM) is sensitive to optical absorption, while optical coherence tomography (OCT) is based on optical backscattering. Combining PAM and OCT can provide complementary information about biological tissue. Here we present a combined optical-resolution PAM (ORPAM) and OCT system that is integrated through a miniature probe with an overall diameter of 2.3 mm, suitable for insertion through a standard endoscopic or laparoscopic port during minimally invasive surgery or endoscopic exam. The hybrid probe consists of a common optical path for OCT (light delivery/detection) and ORPAM (light excitation) and a 10 MHz unfocused ultrasound transducer for photoacoustic detection ...

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    6. Quantitative polarized light microscopy of unstained mammalian cochlear sections

      Quantitative polarized light microscopy of unstained mammalian cochlear sections

      Hearing loss is the most common sensory deficit in the world, and most frequently it originates in the inner ear. Yet, the inner ear has been difficult to access for diagnosis because of its small size, delicate nature, complex three-dimensional anatomy, and encasement in the densest bone in the body. Evolving optical methods are promising to afford cellular diagnosis of pathologic changes in the inner ear. To appropriately interpret results from these emerging technologies, it is important to characterize optical properties of cochlear tissues. Here, we focus on that characterization using quantitative polarized light microscopy (qPLM) applied to unstained cochlear ...

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    7. Motility imaging via optical coherence phase microscopy enables label-free monitoring of tissue growth and viability in 3D tissue-engineering scaffolds

      Motility imaging via optical coherence phase microscopy enables label-free monitoring of tissue growth and viability in 3D tissue-engineering scaffolds

      As the field of tissue engineering continues to progress, there is a deep need for non-invasive, label-free imaging technologies that can monitor tissue growth and health within thick three-dimensional (3D) constructs. Amongst the many imaging modalities under investigation, optical coherence tomography (OCT) has emerged as a promising tool, enabling non-destructive in situ characterization of scaffolds and engineered tissues. However, the lack of optical contrast between cells and scaffold materials using this technique remains a challenge. In this communication, we show that mapping the optical phase fluctuations resulting from cellular viability and motility allows for the distinction of live cells from ...

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    8. Supercontinuum sources make their presence felt

      Supercontinuum sources make their presence felt

      Market for the ultra-broadband sources and related technology estimated at $50 million, with microscopy a key application. After transitioning from a laboratory curiosity to a genuine commercial tool in recent years, supercontinuum sources have emerged to create a fledgling marketplace. The point was one of several made by Wilhelm Kaenders, co-founder and co-president of Toptica Photonics, at the Lasers & Photonics Marketplace Seminar in San Francisco last week. “This new light source is finding applications in fields ranging from optical coherence tomography (OCT), frequency metrology, and fluorescence lifetime imaging microscopy (FLIM), to optical communications and gas sensing,” he told the conference ...

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    9. Systems and methods for surgical microscope and optical coherence tomography (OCT) imaging

      Systems and methods for surgical microscope and optical coherence tomography (OCT) imaging

      A surgical microscope assembly includes a microscope main objective and microscope imaging optics. The microscope main objective and microscope imaging optics define a viewing beam path that passes from a sample through the microscope main objective and the microscope imaging optics. The assembly includes an optical coherence tomography (OCT) unit having an illumination beam and a collection beam and a beamsplitter between the microscope main objective and the microscope imaging optics. The beamsplitter is configured to direct a portion of light from the microscope main objective to the microscope imaging optics and to direct another portion of light from the ...

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    10. Adaptive optical probe design for optical coherence tomography and microscopy using tunable optics

      Adaptive optical probe design for optical coherence tomography and microscopy using tunable optics

      We present a tunable, adaptive optical imaging probe for multimodal imaging such as optical coherence tomography and microscopy. The probe is compatible with forward-looking scanning laser imaging devices such as an endoscope. The lens configuration includes a tunable iris and two varifocal lenses, both driven by microelectrofluidics, as well as several conventional fixed focus lenses. The modulation transfer function and spot size in the focal plane is evaluated, and we show using optical simulations that there are three possible imaging modes with different transverse resolutions and focal depths. ]

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    11. Feature Of The Week 1/6/13: Johannes Kepler University Linz Investigates Full-Filed Optical Coherence Microscopy For Dynamic Imaging

      Feature Of The Week 1/6/13: Johannes Kepler University Linz Investigates Full-Filed Optical Coherence Microscopy For Dynamic Imaging

      The observation of internal dynamic processes is a crucial task in biomedicine as well as for material sciences, with full-field optical coherence microscopy (FF-OCM) exhibiting advantageous features: the full image content is taken at once at a defined depth position with a high lateral resolution. Usually two-dimensional (2D) CCD detectors are applied or - for high speed FF-OCM imaging - complementary metal oxide semiconductor (CMOS) cameras. Besides a fast optical acquisition setup, an appropriate demodulation scheme has also to be realized: In the case of the acquisition of static scenes, phase stepping is conventionally used, with multiple phase-shifted frames being recorded. However ...

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    12. Evaluation of a Completely Robotized Neurosurgical Operating Microscope

      Evaluation of a Completely Robotized Neurosurgical Operating Microscope

      BACKGROUND: Operating microscopes are essential for most neurosurgical procedures. Modern robot-assisted controls offer new possibilities, combining the advantages of conventional and automated systems. OBJECTIVE: We evaluated the prototype of a completely robotized operating microscope with an integrated optical coherence tomography module. METHODS: A standard operating microscope was fitted with motors and control instruments, with the manual control mode and balance preserved. In the robot mode, the microscope was steered by a remote control that could be fixed to a surgical instrument. External encoders and accelerometers tracked microscope movements. The microscope was additionally fitted with an optical coherence tomography-scanning module. RESULTS ...

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    13. Watching while listening to the interaction of photons with bio-tissues

      Watching while listening to the interaction of photons with bio-tissues

      Using a single light source to carry out optical coherence tomography and photoacoustic microscopy simultaneously enables novel studies of optical scattering and absorption in biological tissues. Optical coherence tomography (OCT) and photoacoustic microscopy (PAM) are two microscopic, three-dimensional, noninvasive imaging modalities that are based on different contrast mechanisms. OCT mainly images the optical scattering properties of a sample whereas PAM images optical absorption. Due to these different contrast mechanisms, OCT and PAM provide complementary information about biological tissues. OCT images the microanatomy of a sample (e.g., the histology-like cross-sectional image). It can also image the blood flow velocity by ...

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    14. Systems and methods for performing Gabor-domain optical coherence microscopy

      Systems and methods for performing Gabor-domain optical coherence microscopy

      In one embodiment, imaging a medium under evaluation includes generating acquired images of the medium, each acquired image comprising a cross-sectional image along a lateral and a depth direction of the medium that results from scanning the medium at a different depths, filtering each acquired image to remove out-of-focus portions of the images and generate filtered images, and merging the filtered images to form a high-resolution fused image.

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    15. Three-dimensional imaging of normal skin and nonmelanoma skin cancer with cellular resolution using Gabor domain optical coherence microscopy

      Three-dimensional imaging of normal skin and nonmelanoma skin cancer with cellular resolution using Gabor domain optical coherence microscopy

      We investigate morphological differences in three-dimensional (3-D) images with cellular resolution between nonmelanoma skin cancer and normal skin using Gabor domain optical coherence microscopy. As a result, we show for the first time cellular optical coherence images of 3-D features differentiating cancerous skin from normal skin. In addition, in vivo volumetric images of normal skin from different anatomic locations are shown and compared.

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    16. Optical Coherence Photoacoustic Microscopy

      Optical Coherence Photoacoustic Microscopy

      A system and method for providing an optical coherence photoacoustic (OC-PAM) microscopy. An OC-PAM microscope includes a light source that outputs light, a scanner, a detector, a transducer, and an image processing module. The scanner receives the light and scans the light across a sample. The detector receives reflected light from the sample in response to the scanned light. The transducer detects photoacoustic waves induced in the sample by the scanned light. The image processing module receives output from the detector and the transducer and generates a photoacoustic microscopy (PAM) image and an optical coherence tomography (OCT) image based on ...

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    17. A Microscope in a Needle

      A Microscope in a Needle

      A microscope small enough to fit into a needle creates many new possibilities for optics in medicine. We have developed a range of optical coherence tomography (OCT) needle probes. Connected to an OCT scanner via a single mode fiber, the probes are constructed by fusing exact lengths of no-core fiber and graded-index fiber to focus a broadband light beam. We terminated the optics with anglepolished, gold-coated no-core fiber to deflect the beam. Encased in a needle (outer diameter 310 ?m), these probes are capable of 3-D imaging. However, the important developments of 2012 have been where we have taken these ...

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    18. Full-field optical coherence microscopy with Riesz transform-based demodulation for dynamic imaging

      Full-field optical coherence microscopy with Riesz transform-based demodulation for dynamic imaging

      We present dynamic full-field optical coherence microscope imaging using a scientific complementary metal oxide semiconductor camera in conjunction with a demodulation scheme based on the Riesz transform and monogenic signals. The potential of our approach is verified by a comparison with conventional phase-stepping as well as with an analytic reconstruction method and finally exemplified for dynamic mechanical testing of a polymer/fiber composite structure.

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    19. OCT measuring method and system

      OCT measuring method and system

      A microscopy system and method allow observing a fluorescent substance accumulated in a tissue. The tissue can be observed at a same time both with visible light and with fluorescent light. It is possible to observe a series of previously recorded fluorescent light images in superposition with the visible light images. An end of the series of images may be automatically determined. A thermal protective filter may be inserted into a beam path of an illuminating system at such automatically determined end of the series. Further, the fluorescent light image may be analyzed for identifying a coherent fluorescent portion thereof ...

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    20. Label-Free Imaging of Cerebral β-Amyloidosis with Extended-Focus Optical Coherence Microscopy

      Label-Free Imaging of Cerebral β-Amyloidosis with Extended-Focus Optical Coherence Microscopy

      We demonstrate label-free imaging of cerebral β-amyloidosis ex vivo and in a living mouse model of Alzheimer's disease using extended-focus Fourier domain optical coherence microscopy (xfOCM). xfOCM provides 3D, high-resolution images of individual β-amyloid plaques in the brain parenchyma and vasculature and requires no staining of the Alzheimeric sample under investigation. xfOCM also opens the possibility to perform minimally invasive studies of β-amyloid pathology in vivo , without the use of labeling methods, which potentially confound experimental finding

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    21. Spatial and temporal coherence effects in interference microscopy and full-field optical coherence tomography

      Spatial and temporal coherence effects in interference microscopy and full-field optical coherence tomography

      Low-coherence optical microscopy or optical coherence microscopy uses light with short coherence length. The well-known case is: “white-light interferometry”, which became recently more known as: “optical coherence tomography”. However, when lenses and microscope objectives are used to create interferometric images, in what is known classically as “interference microscopy” or today as “full-field optical coherence tomography” the spatial coherence starts to play a critical role. In this article the coherence effects in low-coherence optical microscopy are reviewed. As this technology is becoming increasingly publicized due to its importance in three-dimensional imaging, particularly of scattering biological media and optical metrology, the understanding ...

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    22. LLTECH & partners receive a €3.099M European Union CORDIS Award for Non-Invasive Optical Biopsy for Cancer Assessment using ultra high resolution FF-OCT

      LLTECH & partners receive a €3.099M European Union CORDIS Award for Non-Invasive Optical Biopsy for Cancer Assessment using ultra high resolution FF-OCT

      The European Union recently made a CORDIS Award for €3,099,481 for Non-Invasive Optical Biopsy for Cancer Assessment using ultra high resolution Full-Field Optical Coherence Tomography. The principal investigator is Fabrice Harms from LLTech. The program starts in 2012 and ends in 2015. Below is a summary of the proposed work. For more information see this link. Along the cancer care workflow, existing preoperative and intraoperative procedures such as the identification of small tumourous areas or the precise resection of tumours show significant fail rates, due to the inability of current imaging techniques to perform a reliable in situ ...

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    23. Fast three-dimensional imaging of gold nanoparticles in living cells with photothermal optical lock-in Optical Coherence Microscopy

      Fast three-dimensional imaging of gold nanoparticles in living cells with photothermal optical lock-in Optical Coherence Microscopy

      We introduce photothermal optical lock-in Optical Coherence Microscopy (poli-OCM), a volumetric imaging technique, which combines the depth sectioning of OCM with the high sensitivity of photothermal microscopy while maintaining the fast acquisition speed inherent to OCM. We report on the detection of single 40 nm gold particles with a 0.5 μm lateral and 2 μm axial resolution over a 50 μm depth of field and the three-dimensional localization of gold colloids within living cells. In combination with intrinsic sample contrast measured with dark-field OCM, poli-OCM offers a versatile platform for functional cell imaging.

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    24. Systems and methods for treating glaucoma and systems and methods for imaging a portion of an eye

      Systems and methods for treating glaucoma and systems and methods for imaging a portion of an eye

      Systems and methods are described for imaging an eye portion or for treating glaucoma in an eye of a patient. In a first step an optical microscopic image of a portion of the eye is acquired. In the optical microscopic image a distinguishable anatomical structure is identified to predict a location of a volume portion to be imaged three-dimensionally. Three-dimensional imaging of the located volume portion is performed by acquiring an optical coherence tomography image of the located volume portion. The volume portion is treated by either directing a laser beam to the volume portion or inserting an implant based ...

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    1-24 of 342 1 2 3 4 ... 13 14 15 »
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