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Sample records for 3d confocal laser

  1. 3-D reconstruction of neurons from multichannel confocal laser scanning image series.

    PubMed

    Wouterlood, Floris G

    2005-08-01

    A confocal laser scanning microscope (CLSM) collects information from a thin, focal plane and ignores out-of-focus information. The operator configures separate channels (laser, filters, detector settings) for each fluorochrome used in a particular experiment. Then, 3-D reconstructions are made from Z-series of confocal images: one series per channel. Channel signal separation is extremely important and measures to avoid bleaching are vital. Post-acquisition deconvolution of the image series is then performed to increase resolution. In the 3-D reconstruction program described in this unit, reconstructions can be inspected in real time from any viewing angle. By altering viewing angles and by switching channels off and on, the spatial relationship of 3-D-reconstructed structures with respect to structures seen in other channels can be studied. Since each brand of CLSM, computer program, and 3-D reconstruction package has its own proprietary set of procedures, a general approach is provided wherever possible.

  2. 3-D reconstruction of neurons from multichannel confocal laser scanning image series.

    PubMed

    Wouterlood, Floris G

    2014-04-10

    A confocal laser scanning microscope (CLSM) collects information from a thin, focal plane and ignores out-of-focus information. Scanning of a specimen, with stepwise axial (Z-) movement of the stage in between each scan, produces Z-series of confocal images of a tissue volume, which then can be used to 3-D reconstruct structures of interest. The operator first configures separate channels (e.g., laser, filters, and detector settings) for each applied fluorochrome and then acquires Z-series of confocal images: one series per channel. Channel signal separation is extremely important. Measures to avoid bleaching are vital. Post-acquisition deconvolution of the image series is often performed to increase resolution before 3-D reconstruction takes place. In the 3-D reconstruction programs described in this unit, reconstructions can be inspected in real time from any viewing angle. By altering viewing angles and by switching channels off and on, the spatial relationships of 3-D-reconstructed structures with respect to structures visualized in other channels can be studied. Since each brand of CLSM, computer program, and 3-D reconstruction package has its own proprietary set of procedures, a general approach is provided in this protocol wherever possible.

  3. Confocal laser scanning microscopy and 3-D reconstructions of neuronal structures in human brain cortex.

    PubMed

    Belichenko, P V; Dahlström, A

    1995-09-01

    Human brain material was studied with Lucifer yellow (LY) microinjections, indirect Texas red immunofluorescence, and confocal laser scanning microscopy (CLSM). The scanned images were transferred to a Silicon Graphics (SG) IRIS computer equipped with software for reconstructing the 3-D architecture of cells. By employing dual channel CLSM (Bio-Rad MRC 600), LY-injected cells and Texas red immunofluorescence could be studied simultaneously. Autopsy material with 2- to 48-h postmortem delays (6 control and 2 Rett's syndrome cases) as well as biopsy material (14 cases with therapy-resistant partial epilepsy--TRPE--undergoing neurosurgery) were used. In each specimen, 100-200 pyramidal and nonpyramidal neurons were visualized by LY microinjection. Single neurons were imaged and 2-D reconstructions of each neuron were made using z-projections of serial optical images; 3-D reconstructions and rotations were computed using the SG workstation, with VoxelView software from Vital Images (UK), and stored in a "neuronal library" on laser or magnetic optical disks. In Ret's syndrome cases and in patients with TRPE various abnormalities in the dendritic geometry of pyramidal and nonpyramidal cells have been found. The combination of LY injections with immunofluorescence allows the investigation of transmitter-related substances around the LY-injected cells. Using antibodies to synaptic vesicle proteins, presynaptic elements docking onto individual spines have been demonstrated. This approach may contribute to the understanding of different neurological and psychiatric disorders and may be useful in the Mapping of the Human Brain project. It may also be integrated with functional imaging by PET scan and with the human genome project.

  4. 3D Quantitative Confocal Laser Microscopy of Ilmenite Volume Distribution in Alpe Arami Olivine

    NASA Astrophysics Data System (ADS)

    Bozhilov, K. N.

    2001-12-01

    The deep origin of the Alpe Arami garnet lherzolite massif in the Swiss Alps proposed by Dobrzhinetskaya et al. (Science, 1996) has been a focus of heated debate. One of the lines of evidence supporting an exhumation from more than 200 km depth includes the abundance, distribution, and orientation of magnesian ilmenite rods in the oldest generation of olivine. This argument has been disputed in terms of the abundance of ilmenite and consequently the maximum TiO2 content in the discussed olivine. In order to address this issue, we have directly measured the volume fraction of ilmenite of the oldest generation of olivine by applying confocal laser scanning microscopy (CLSM). CLSM is a method which allows for three-dimensional imaging and quantitative volume determination by optical sectioning of the objects. The images for 3D reconstruction and measurements were acquired from petrographic thin sections in reflected laser light with 488 nm wavelength. Measurements of more than 80 olivine grains in six thin sections of our material yielded an average volume fraction of 0.31% ilmenite in the oldest generation of olivine from Alpe Arami. This translates into 0.23 wt.% TiO2 in olivine with error in determination of ±0.097 wt.%, a value significantly different from that of 0.02 to 0.03 wt.% TiO2 determined by Hacker et al. (Science, 1997) by a broad-beam microanalysis technique. During the complex geological history of the Alpe Arami massif, several events of metamorphism are recorded which all could have caused increased mobility of the mineral components. Evidence for loss of TiO2 from olivine is the tendency for high densities of ilmenite to be restricted to cores of old grains, the complete absence of ilmenite inclusions from the younger, recrystallized, generation of olivine, and reduction in ilmenite size and abundance in more serpentinized specimens. These observations suggest that only olivine grains with the highest concentrations of ilmenite are close to the

  5. 3-D confocal laser scanning microscopy used in morphometric analysis of rat Purkinje cell dendritic spines after chronic ethanol consumption.

    PubMed

    Wenisch, S; Fortmann, B; Steinmetz, T; Kriete, A; Leiser, R; Bitsch, I

    1998-12-01

    A confocal laser scanning microscope (with a 543 nm laser) was used for imaging rat Purkinje cell dendritic spines at high 3-D resolution. In a nutritionally controlled study of the rat, 5 months of ethanol consumption was demonstrated to alter the spines of Purkinje cell dendrites in rat cerebellum. Intact spines showed significant elongation after ethanol exposure, whereas this neuromorphological alteration could not be detected in controls. Spine elongation could be regarded as compensative growth of spines in search of new synaptic contacts due to alcohol induced cell loss.

  6. Nondestructive 3D confocal laser imaging with deconvolution of seven whole stardust tracks with complementary XRF and quantitative analysis

    SciTech Connect

    Greenberg, M.; Ebel, D.S.

    2009-03-19

    We present a nondestructive 3D system for analysis of whole Stardust tracks, using a combination of Laser Confocal Scanning Microscopy and synchrotron XRF. 3D deconvolution is used for optical corrections, and results of quantitative analyses of several tracks are presented. The Stardust mission to comet Wild 2 trapped many cometary and ISM particles in aerogel, leaving behind 'tracks' of melted silica aerogel on both sides of the collector. Collected particles and their tracks range in size from submicron to millimeter scale. Interstellar dust collected on the obverse of the aerogel collector is thought to have an average track length of {approx}15 {micro}m. It has been our goal to perform a total non-destructive 3D textural and XRF chemical analysis on both types of tracks. To that end, we use a combination of Laser Confocal Scanning Microscopy (LCSM) and X Ray Florescence (XRF) spectrometry. Utilized properly, the combination of 3D optical data and chemical data provides total nondestructive characterization of full tracks, prior to flattening or other destructive analysis methods. Our LCSM techniques allow imaging at 0.075 {micro}m/pixel, without the use of oil-based lenses. A full textural analysis on track No.82 is presented here as well as analysis of 6 additional tracks contained within 3 keystones (No.128, No.129 and No.140). We present a method of removing the axial distortion inherent in LCSM images, by means of a computational 3D Deconvolution algorithm, and present some preliminary experiments with computed point spread functions. The combination of 3D LCSM data and XRF data provides invaluable information, while preserving the integrity of the samples for further analysis. It is imperative that these samples, the first extraterrestrial solids returned since the Apollo era, be fully mapped nondestructively in 3D, to preserve the maximum amount of information prior to other, destructive analysis.

  7. Parallel deconvolution of large 3D images obtained by confocal laser scanning microscopy.

    PubMed

    Pawliczek, Piotr; Romanowska-Pawliczek, Anna; Soltys, Zbigniew

    2010-03-01

    Various deconvolution algorithms are often used for restoration of digital images. Image deconvolution is especially needed for the correction of three-dimensional images obtained by confocal laser scanning microscopy. Such images suffer from distortions, particularly in the Z dimension. As a result, reliable automatic segmentation of these images may be difficult or even impossible. Effective deconvolution algorithms are memory-intensive and time-consuming. In this work, we propose a parallel version of the well-known Richardson-Lucy deconvolution algorithm developed for a system with distributed memory and implemented with the use of Message Passing Interface (MPI). It enables significantly more rapid deconvolution of two-dimensional and three-dimensional images by efficiently splitting the computation across multiple computers. The implementation of this algorithm can be used on professional clusters provided by computing centers as well as on simple networks of ordinary PC machines.

  8. 3-D laser confocal microscopy study of the oxidation of NdFeB magnets in atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Meakin, J. P.; Speight, J. D.; Sheridan, R. S.; Bradshaw, A.; Harris, I. R.; Williams, A. J.; Walton, A.

    2016-08-01

    Neodymium iron boron (NdFeB) magnets are used in a number of important applications, such as generators in gearless wind turbines, motors in electric vehicles and electronic goods (e.g.- computer hard disk drives, HDD). Hydrogen can be used as a processing gas to separate and recycle scrap sintered Nd-Fe-B magnets from end-of-life products to form a powder suitable for recycling. However, the magnets are likely to have been exposed to atmospheric conditions prior to processing, and any oxidation could lead to activation problems for the hydrogen decrepitation reaction. Many previous studies on the oxidation of NdFeB magnets have been performed at elevated temperatures; however, few studies have been formed under atmospheric conditions. In this paper a combination of 3-D laser confocal microscopy and Raman spectroscopy have been used to assess the composition, morphology and rate of oxidation/corrosion on scrap sintered NdFeB magnets. Confocal microscopy has been employed to measure the growth of surface reaction products at room temperature, immediately after exposure to air. The results showed that there was a significant height increase at the triple junctions of the Nd-rich grain boundaries. Using Raman spectroscopy, the product was shown to consist of Nd2O3 and formed only on the Nd-rich triple junctions. The diffusion coefficient of the triple junction reaction product growth at 20 °C was determined to be approximately 4 × 10-13 cm2/sec. This value is several orders of magnitude larger than values derived from the diffusion controlled oxide growth observations at elevated temperatures in the literature. This indicates that the growth of the room temperature oxidation products are likely defect enhanced processes at the NdFeB triple junctions.

  9. 3D Imaging of Porous Media Using Laser Scanning Confocal Microscopy with Application to Microscale Transport Processes

    SciTech Connect

    Fredrich, J.T.

    1999-02-10

    We present advances in the application of laser scanning confocal microscopy (LSCM) to image, reconstruct, and characterize statistically the microgeometry of porous geologic and engineering materials. We discuss technical and practical aspects of this imaging technique, including both its advantages and limitations. Confocal imaging can be used to optically section a material, with sub-micron resolution possible in the lateral and axial planes. The resultant volumetric image data, consisting of fluorescence intensities for typically {approximately}50 million voxels in XYZ space, can be used to reconstruct the three-dimensional structure of the two-phase medium. We present several examples of this application, including studying pore geometry in sandstone, characterizing brittle failure processes in low-porosity rock deformed under triaxial loading conditions in the laboratory, and analyzing the microstructure of porous ceramic insulations. We then describe approaches to extract statistical microgeometric descriptions from volumetric image data, and present results derived from confocal volumetric data sets. Finally, we develop the use of confocal image data to automatically generate a three-dimensional mesh for numerical pore-scale flow simulations.

  10. 3D imaging of cement-based materials at submicron resolution by combining laser scanning confocal microscopy with serial sectioning.

    PubMed

    Yio, M H N; Mac, M J; Wong, H S; Buenfeld, N R

    2015-05-01

    In this paper, we present a new method to reconstruct large volumes of nontransparent porous materials at submicron resolution. The proposed method combines fluorescence laser scanning confocal microscopy with serial sectioning to produce a series of overlapping confocal z-stacks, which are then aligned and stitched based on phase correlation. The method can be extended in the XY plane to further increase the overall image volume. Resolution of the reconstructed image volume does not degrade with increase in sample size. We have used the method to image cementitious materials, hardened cement paste and concrete and the results obtained show that the method is reliable. Possible applications of the method such as three-dimensional characterization of the pores and microcracks in hardened concrete, three-dimensional particle shape characterization of cementitious materials and three-dimensional characterization of other porous materials such as rocks and bioceramics are discussed.

  11. Characterization of a subwavelength-scale 3D void structure using the FDTD-based confocal laser scanning microscopic image mapping technique.

    PubMed

    Choi, Kyongsik; Chon, James W; Gu, Min; Lee, Byoungho

    2007-08-20

    In this paper, a simple confocal laser scanning microscopic (CLSM) image mapping technique based on the finite-difference time domain (FDTD) calculation has been proposed and evaluated for characterization of a subwavelength-scale three-dimensional (3D) void structure fabricated inside polymer matrix. The FDTD simulation method adopts a focused Gaussian beam incident wave, Berenger's perfectly matched layer absorbing boundary condition, and the angular spectrum analysis method. Through the well matched simulation and experimental results of the xz-scanned 3D void structure, we first characterize the exact position and the topological shape factor of the subwavelength-scale void structure, which was fabricated by a tightly focused ultrashort pulse laser. The proposed CLSM image mapping technique based on the FDTD can be widely applied from the 3D near-field microscopic imaging, optical trapping, and evanescent wave phenomenon to the state-of-the-art bio- and nanophotonics.

  12. 3D digital image processing for biofilm quantification from confocal laser scanning microscopy: Multidimensional statistical analysis of biofilm modeling

    NASA Astrophysics Data System (ADS)

    Zielinski, Jerzy S.

    The dramatic increase in number and volume of digital images produced in medical diagnostics, and the escalating demand for rapid access to these relevant medical data, along with the need for interpretation and retrieval has become of paramount importance to a modern healthcare system. Therefore, there is an ever growing need for processed, interpreted and saved images of various types. Due to the high cost and unreliability of human-dependent image analysis, it is necessary to develop an automated method for feature extraction, using sophisticated mathematical algorithms and reasoning. This work is focused on digital image signal processing of biological and biomedical data in one- two- and three-dimensional space. Methods and algorithms presented in this work were used to acquire data from genomic sequences, breast cancer, and biofilm images. One-dimensional analysis was applied to DNA sequences which were presented as a non-stationary sequence and modeled by a time-dependent autoregressive moving average (TD-ARMA) model. Two-dimensional analyses used 2D-ARMA model and applied it to detect breast cancer from x-ray mammograms or ultrasound images. Three-dimensional detection and classification techniques were applied to biofilm images acquired using confocal laser scanning microscopy. Modern medical images are geometrically arranged arrays of data. The broadening scope of imaging as a way to organize our observations of the biophysical world has led to a dramatic increase in our ability to apply new processing techniques and to combine multiple channels of data into sophisticated and complex mathematical models of physiological function and dysfunction. With explosion of the amount of data produced in a field of biomedicine, it is crucial to be able to construct accurate mathematical models of the data at hand. Two main purposes of signal modeling are: data size conservation and parameter extraction. Specifically, in biomedical imaging we have four key problems

  13. Excitation beyond the monochromatic laser limit: simultaneous 3-D confocal and multiphoton microscopy with a tapered fiber as white-light laser source.

    PubMed

    Betz, Timo; Teipel, Jörn; Koch, Daniel; Härtig, Wolfgang; Guck, Jochen; Käs, Josef; Giessen, Harald

    2005-01-01

    Confocal and multiphoton microscopy are essential tools in modern life sciences. They allow fast and highly resolved imaging of a steadily growing number of fluorescent markers, ranging from fluorescent proteins to quantum dots and other fluorophores, used for the localization of molecules and the quantitative detection of molecular properties within living cells and organisms. Up to now, only one physical limitation seemed to be unavoidable. Both confocal and multiphoton microscopy rely on lasers as excitation sources, and their monochromatic radiation allows only a limited number of simultaneously usable dyes, which depends on the specific number of laser lines available in the used microscope. We have overcome this limitation by successfully replacing all excitation lasers in a standard confocal microscope with pulsed white light ranging from 430 to 1300 nm generated in a tapered silica fiber. With this easily reproducible method, simultaneous confocal and multiphoton microscopy was demonstrated. By developing a coherent and intense laser source with spectral width comparable to a mercury lamp, we provide the flexibility to excite any desired fluorophore combination.

  14. 3D confocal reconstruction of gene expression in mouse.

    PubMed

    Hecksher-Sørensen, J; Sharpe, J

    2001-01-01

    Three-dimensional computer reconstructions of gene expression data will become a valuable tool in biomedical research in the near future. However, at present the process of converting in situ expression data into 3D models is a highly specialized and time-consuming procedure. Here we present a method which allows rapid reconstruction of whole-mount in situ data from mouse embryos. Mid-gestation embryos were stained with the alkaline phosphotase substrate Fast Red, which can be detected using confocal laser scanning microscopy (CLSM), and cut into 70 microm sections. Each section was then scanned and digitally reconstructed. Using this method it took two days to section, digitize and reconstruct the full expression pattern of Shh in an E9.5 embryo (a 3D model of this embryo can be seen at genex.hgu.mrc.ac.uk). Additionally we demonstrate that this technique allows gene expression to be studied at the single cell level in intact tissue.

  15. Frames-Based Denoising in 3D Confocal Microscopy Imaging.

    PubMed

    Konstantinidis, Ioannis; Santamaria-Pang, Alberto; Kakadiaris, Ioannis

    2005-01-01

    In this paper, we propose a novel denoising method for 3D confocal microscopy data based on robust edge detection. Our approach relies on the construction of a non-separable frame system in 3D that incorporates the Sobel operator in dual spatial directions. This multidirectional set of digital filters is capable of robustly detecting edge information by ensemble thresholding of the filtered data. We demonstrate the application of our method to both synthetic and real confocal microscopy data by comparing it to denoising methods based on separable 3D wavelets and 3D median filtering, and report very encouraging results.

  16. 3D Image Analysis of Geomaterials using Confocal Microscopy

    NASA Astrophysics Data System (ADS)

    Mulukutla, G.; Proussevitch, A.; Sahagian, D.

    2009-05-01

    Confocal microscopy is one of the most significant advances in optical microscopy of the last century. It is widely used in biological sciences but its application to geomaterials lingers due to a number of technical problems. Potentially the technique can perform non-invasive testing on a laser illuminated sample that fluoresces using a unique optical sectioning capability that rejects out-of-focus light reaching the confocal aperture. Fluorescence in geomaterials is commonly induced using epoxy doped with a fluorochrome that is impregnated into the sample to enable discrimination of various features such as void space or material boundaries. However, for many geomaterials, this method cannot be used because they do not naturally fluoresce and because epoxy cannot be impregnated into inaccessible parts of the sample due to lack of permeability. As a result, the confocal images of most geomaterials that have not been pre-processed with extensive sample preparation techniques are of poor quality and lack the necessary image and edge contrast necessary to apply any commonly used segmentation techniques to conduct any quantitative study of its features such as vesicularity, internal structure, etc. In our present work, we are developing a methodology to conduct a quantitative 3D analysis of images of geomaterials collected using a confocal microscope with minimal amount of prior sample preparation and no addition of fluorescence. Two sample geomaterials, a volcanic melt sample and a crystal chip containing fluid inclusions are used to assess the feasibility of the method. A step-by-step process of image analysis includes application of image filtration to enhance the edges or material interfaces and is based on two segmentation techniques: geodesic active contours and region competition. Both techniques have been applied extensively to the analysis of medical MRI images to segment anatomical structures. Preliminary analysis suggests that there is distortion in the

  17. 3D imaging of neutron tracks using confocal microscopy

    NASA Astrophysics Data System (ADS)

    Gillmore, Gavin; Wertheim, David; Flowers, Alan

    2016-04-01

    Neutron detection and neutron flux assessment are important aspects in monitoring nuclear energy production. Neutron flux measurements can also provide information on potential biological damage from exposure. In addition to the applications for neutron measurement in nuclear energy, neutron detection has been proposed as a method of enhancing neutrino detectors and cosmic ray flux has also been assessed using ground-level neutron detectors. Solid State Nuclear Track Detectors (or SSNTDs) have been used extensively to examine cosmic rays, long-lived radioactive elements, radon concentrations in buildings and the age of geological samples. Passive SSNTDs consisting of a CR-39 plastic are commonly used to measure radon because they respond to incident charged particles such as alpha particles from radon gas in air. They have a large dynamic range and a linear flux response. We have previously applied confocal microscopy to obtain 3D images of alpha particle tracks in SSNTDs from radon track monitoring (1). As a charged particle traverses through the polymer it creates an ionisation trail along its path. The trail or track is normally enhanced by chemical etching to better expose radiation damage, as the damaged area is more sensitive to the etchant than the bulk material. Particle tracks in CR-39 are usually assessed using 2D optical microscopy. In this study 6 detectors were examined using an Olympus OLS4100 LEXT 3D laser scanning confocal microscope (Olympus Corporation, Japan). The detectors had been etched for 2 hours 50 minutes at 85 °C in 6.25M NaOH. Post etch the plastics had been treated with a 10 minute immersion in a 2% acetic acid stop bath, followed by rinsing in deionised water. The detectors examined had been irradiated with a 2mSv neutron dose from an Am(Be) neutron source (producing roughly 20 tracks per mm2). We were able to successfully acquire 3D images of neutron tracks in the detectors studied. The range of track diameter observed was between 4

  18. Note: development of high speed confocal 3D profilometer.

    PubMed

    Ang, Kar Tien; Fang, Zhong Ping; Tay, Arthur

    2014-11-01

    A high-speed confocal 3D profilometer based on the chromatic confocal technology and spinning Nipkow disk technique has been developed and tested. It can measure a whole surface topography by taking only one image that requires less than 0.3 s. Surface height information is retrieved based on the ratios of red, green, and blue color information. A new vector projection technique has developed to enhance the vertical resolution of the measurement. The measurement accuracy of the prototype system has been verified via different test samples.

  19. Novel application of confocal laser scanning microscopy and 3D volume rendering toward improving the resolution of the fossil record of charcoal.

    PubMed

    Belcher, Claire M; Punyasena, Surangi W; Sivaguru, Mayandi

    2013-01-01

    Variations in the abundance of fossil charcoals between rocks and sediments are assumed to reflect changes in fire activity in Earth's past. These variations in fire activity are often considered to be in response to environmental, ecological or climatic changes. The role that fire plays in feedbacks to such changes is becoming increasingly important to understand and highlights the need to create robust estimates of variations in fossil charcoal abundance. The majority of charcoal based fire reconstructions quantify the abundance of charcoal particles and do not consider the changes in the morphology of the individual particles that may have occurred due to fragmentation as part of their transport history. We have developed a novel application of confocal laser scanning microscopy coupled to image processing that enables the 3-dimensional reconstruction of individual charcoal particles. This method is able to measure the volume of both microfossil and mesofossil charcoal particles and allows the abundance of charcoal in a sample to be expressed as total volume of charcoal. The method further measures particle surface area and shape allowing both relationships between different size and shape metrics to be analysed and full consideration of variations in particle size and size sorting between different samples to be studied. We believe application of this new imaging approach could allow significant improvement in our ability to estimate variations in past fire activity using fossil charcoals.

  20. Unsupervised noise removal algorithms for 3-D confocal fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Roysam, Badrinath; Bhattacharjya, Anoop K.; Srinivas, Chukka; Szarowski, Donald H.; Turner, James N.

    1992-06-01

    Fast algorithms are presented for effective removal of the noise artifact in 3-D confocal fluorescence microscopy images of extended spatial objects such as neurons. The algorithms are unsupervised in the sense that they automatically estimate and adapt to the spatially and temporally varying noise level in the microscopy data. An important feature of the algorithms is the fact that a 3-D segmentation of the field emerges jointly with the intensity estimate. The role of the segmentation is to limit any smoothing to the interiors of regions and hence avoid the blurring that is associated with conventional noise removal algorithms. Fast computation is achieved by parallel computation methods, rather than by algorithmic or modelling compromises. The noise-removal proceeds iteratively, starting from a set of approximate user- supplied, or default initial guesses of the underlying random process parameters. An expectation maximization algorithm is used to obtain a more precise characterization of these parameters, that are then input to a hierarchical estimation algorithm. This algorithm computes a joint solution of the related problems corresponding to intensity estimation, segmentation, and boundary-surface estimation subject to a combination of stochastic priors and syntactic pattern constraints. Three-dimensional stereoscopic renderings of processed 3-D images of murine hippocampal neurons are presented to demonstrate the effectiveness of the method. The processed images exhibit increased contrast and significant smoothing and reduction of the background intensity while avoiding any blurring of the neuronal structures.

  1. Tracking tissue section surfaces for automated 3D confocal cytometry

    NASA Astrophysics Data System (ADS)

    Agustin, Ramses; Price, Jeffrey H.

    2002-05-01

    Three-dimensional cytometry, whereby large volumes of tissue would be measured automatically, requires a computerized method for detecting the upper and lower tissue boundaries. In conventional confocal microscopy, the user interactively sets limits for axial scanning for each field-of-view. Biological specimens vary in section thickness, thereby driving the requirement for setting vertical scan limits. Limits could be set arbitrarily large to ensure the entire tissue is scanned, but automatic surface identification would eliminate storing undue numbers of empty optical sections and forms the basis for incorporating lateral microscope stage motion to collect unlimited numbers of stacks. This walk-away automation of 3D confocal scanning for biological imaging is the first sep towards practical, computerized statistical sampling from arbitrarily large tissue volumes. Preliminary results for automatic tissue surface tracking were obtained for phase-contrast microscopy by measuring focus sharpness (previously used for high-speed autofocus by our group). Measurements were taken from 5X5 fields-of-view from hamster liver sections, varying from five to twenty microns in thickness, then smoothed to lessen variations of in-focus information at each axial position. Because image sharpness (as the power of high spatial frequency components) drops across the axial boundaries of a tissue section, mathematical quantities including the full-width at half-maximum, extrema in the first derivative, and second derivative were used to locate the proximal and distal surfaces of a tissue. Results from these tests were evaluated against manual (i.e., visual) determination of section boundaries.

  2. Optimum conditions for high-quality 3D reconstruction in confocal scanning microscopy

    NASA Astrophysics Data System (ADS)

    Kim, Taehoon; Kim, Taejoong; Lee, SeungWoo; Gweon, Dae-Gab; Seo, Jungwoo

    2006-02-01

    Confocal Scanning Microscopy (CSM) is very useful to reconstruct 3D image of Bio-cells and the objects that have specification shape in higher axial and lateral resolution and widely used as measurement instrument. A 3D reconstruction is used to visualize confocal images and consists of following processes. The First process is to get 3D data by collecting a series of images at regular focus intervals (Optical Sectioning). The Second process is to fit a curve to a series of 3D data points each pixel. The Third process is to search height information that has maximum value from curve-fitting. However, because of various systematic errors (NOISE) occurred when collecting the information of images through Optical Sectioning and large peak deviation occurred from curve-fitting error, high quality 3D reconstruction is not expected. Also, it takes much time to 3d Reconstruction by using many 3D data in order to acquire high quality and much cost to improve signal-to-noise (SNR) using a higher power laser. So, we are going to define SNR, peak deviation and the order of curve-fitting as important factors and simulate the relation between the factors in order to find a optimum condition for high quality 3D reconstruction in Confoal Scanning Microscopy. If we use optimum condition obtained by this simulation, using a suitable SNR and the suitable number of data and the suitable n-th order curve-fitting, small peak deviation is expected and then, 3D reconstruction of little better quality is expected. Also, it is expected to save.

  3. Laser Based 3D Volumetric Display System

    DTIC Science & Technology

    1993-03-01

    Literature, Costa Mesa, CA July 1983. 3. "A Real Time Autostereoscopic Multiplanar 3D Display System", Rodney Don Williams, Felix Garcia, Jr., Texas...8217 .- NUMBERS LASER BASED 3D VOLUMETRIC DISPLAY SYSTEM PR: CD13 0. AUTHOR(S) PE: N/AWIU: DN303151 P. Soltan, J. Trias, W. Robinson, W. Dahlke 7...laser generated 3D volumetric images on a rotating double helix, (where the 3D displays are computer controlled for group viewing with the naked eye

  4. High resolution 3D confocal microscope imaging of volcanic ash particles.

    PubMed

    Wertheim, David; Gillmore, Gavin; Gill, Ian; Petford, Nick

    2017-07-15

    We present initial results from a novel high resolution confocal microscopy study of the 3D surface structure of volcanic ash particles from two recent explosive basaltic eruptions, Eyjafjallajökull (2010) and Grimsvötn (2011), in Iceland. The majority of particles imaged are less than 100μm in size and include PM10s, known to be harmful to humans if inhaled. Previous studies have mainly used 2D microscopy to examine volcanic particles. The aim of this study was to test the potential of 3D laser scanning confocal microscopy as a reliable analysis tool for these materials and if so to what degree high resolution surface and volume data could be obtained that would further aid in their classification. First results obtained using an Olympus LEXT scanning confocal microscope with a ×50 and ×100 objective lens are highly encouraging. They reveal a range of discrete particle types characterised by sharp or concave edges consistent with explosive formation and sudden rupture of magma. Initial surface area/volume ratios are given that may prove useful in subsequent modelling of damage to aircraft engines and human tissue where inhalation has occurred.

  5. New data-driven method from 3D confocal microscopy for calculating phytoplankton cell biovolume.

    PubMed

    Roselli, L; Paparella, F; Stanca, E; Basset, A

    2015-06-01

    Confocal laser scanner microscopy coupled with an image analysis system was used to directly determine the shape and calculate the biovolume of phytoplankton organisms by constructing 3D models of cells. The study was performed on Biceratium furca (Ehrenberg) Vanhoeffen, which is one of the most complex-shaped phytoplankton. Traditionally, biovolume is obtained from a standardized set of geometric models based on linear dimensions measured by light microscopy. However, especially in the case of complex-shaped cells, biovolume is affected by very large errors associated with the numerous manual measurements that this entails. We evaluate the accuracy of these traditional methods by comparing the results obtained using geometric models with direct biovolume measurement by image analysis. Our results show cell biovolume measurement based on decomposition into simple geometrical shapes can be highly inaccurate. Although we assume that the most accurate cell shape is obtained by 3D direct biovolume measurement, which is based on voxel counting, the intrinsic uncertainty of this method is explored and assessed. Finally, we implement a data-driven formula-based approach to the calculation of biovolume of this complex-shaped organism. On one hand, the model is obtained from 3D direct calculation. On the other hand, it is based on just two linear dimensions which can easily be measured by hand. This approach has already been used for investigating the complexities of morphology and for determining the 3D structure of cells. It could also represent a novel way to generalize scaling laws for biovolume calculation.

  6. Microfabricating 3D Structures by Laser Origami

    DTIC Science & Technology

    2011-11-09

    technique generates 3D microstructures by controlled out-of- plane folding of 2D patterns through a variety of laser-based digital fabrication...processes. Digital microfabrication techniques such as laser direct-write (LDW) offer a viable alternative for generating 3D self-folding designs. These...folding at the microscale where manual or mechanized actuation of the smaller struc- tures is not practical. LDW techniques allow micromachining and

  7. Estimation of single cell volume from 3D confocal images using automatic data processing

    NASA Astrophysics Data System (ADS)

    Chorvatova, A.; Cagalinec, M.; Mateasik, A.; Chorvat, D., Jr.

    2012-06-01

    Cardiac cells are highly structured with a non-uniform morphology. Although precise estimation of their volume is essential for correct evaluation of hypertrophic changes of the heart, simple and unified techniques that allow determination of the single cardiomyocyte volume with sufficient precision are still limited. Here, we describe a novel approach to assess the cell volume from confocal microscopy 3D images of living cardiac myocytes. We propose a fast procedure based on segementation using active deformable contours. This technique is independent on laser gain and/or pinhole settings and it is also applicable on images of cells stained with low fluorescence markers. Presented approach is a promising new tool to investigate changes in the cell volume during normal, as well as pathological growth, as we demonstrate in the case of cell enlargement during hypertension in rats.

  8. Laser printing of 3D metallic interconnects

    NASA Astrophysics Data System (ADS)

    Beniam, Iyoel; Mathews, Scott A.; Charipar, Nicholas A.; Auyeung, Raymond C. Y.; Piqué, Alberto

    2016-04-01

    The use of laser-induced forward transfer (LIFT) techniques for the printing of functional materials has been demonstrated for numerous applications. The printing gives rise to patterns, which can be used to fabricate planar interconnects. More recently, various groups have demonstrated electrical interconnects from laser-printed 3D structures. The laser printing of these interconnects takes place through aggregation of voxels of either molten metal or of pastes containing dispersed metallic particles. However, the generated 3D structures do not posses the same metallic conductivity as a bulk metal interconnect of the same cross-section and length as those formed by wire bonding or tab welding. An alternative is to laser transfer entire 3D structures using a technique known as lase-and-place. Lase-and-place is a LIFT process whereby whole components and parts can be transferred from a donor substrate onto a desired location with one single laser pulse. This paper will describe the use of LIFT to laser print freestanding, solid metal foils or beams precisely over the contact pads of discrete devices to interconnect them into fully functional circuits. Furthermore, this paper will also show how the same laser can be used to bend or fold the bulk metal foils prior to transfer, thus forming compliant 3D structures able to provide strain relief for the circuits under flexing or during motion from thermal mismatch. These interconnect "ridges" can span wide gaps (on the order of a millimeter) and accommodate height differences of tens of microns between adjacent devices. Examples of these laser printed 3D metallic bridges and their role in the development of next generation electronics by additive manufacturing will be presented.

  9. Counter-sniper 3D laser radar

    NASA Astrophysics Data System (ADS)

    Shepherd, Orr; LePage, Andrew J.; Wijntjes, Geert J.; Zehnpfennig, Theodore F.; Sackos, John T.; Nellums, Robert O.

    1999-01-01

    Visidyne, Inc., teaming with Sandia National Laboratories, has developed the preliminary design for an innovative scannerless 3-D laser radar capable of acquiring, tracking, and determining the coordinates of small caliber projectiles in flight with sufficient precision, so their origin can be established by back projecting their tracks to their source. The design takes advantage of the relatively large effective cross-section of a bullet at optical wavelengths. Kay to its implementation is the use of efficient, high- power laser diode arrays for illuminators and an imaging laser receiver using a unique CCD imager design, that acquires the information to establish x, y (angle-angle) and range coordinates for each bullet at very high frame rates. The detection process achieves a high degree of discrimination by using the optical signature of the bullet, solar background mitigation, and track detection. Field measurements and computer simulations have been used to provide the basis for a preliminary design of a robust bullet tracker, the Counter Sniper 3-D Laser Radar. Experimental data showing 3-D test imagery acquired by a lidar with architecture similar to that of the proposed Counter Sniper 3-D Lidar are presented. A proposed Phase II development would yield an innovative, compact, and highly efficient bullet-tracking laser radar. Such a device would meet the needs of not only the military, but also federal, state, and local law enforcement organizations.

  10. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: LASER POWER MEASUREMENTS

    EPA Science Inventory

    Laser power abstract
    The reliability of the confocal laser-scanning microscope (CLSM) to obtain intensity measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. The laser power test appears to be one ...

  11. Laser 3D micro-manufacturing

    NASA Astrophysics Data System (ADS)

    Piqué, Alberto; Auyeung, Raymond C. Y.; Kim, Heungsoo; Charipar, Nicholas A.; Mathews, Scott A.

    2016-06-01

    Laser-based materials processing techniques are gaining widespread use in micro-manufacturing applications. The use of laser microfabrication techniques enables the processing of micro- and nanostructures from a wide range of materials and geometries without the need for masking and etching steps commonly associated with photolithography. This review aims to describe the broad applications space covered by laser-based micro- and nanoprocessing techniques and the benefits offered by the use of lasers in micro-manufacturing processes. Given their non-lithographic nature, these processes are also referred to as laser direct-write and constitute some of the earliest demonstrations of 3D printing or additive manufacturing at the microscale. As this review will show, the use of lasers enables precise control of the various types of processing steps—from subtractive to additive—over a wide range of scales with an extensive materials palette. Overall, laser-based direct-write techniques offer multiple modes of operation including the removal (via ablative processes) and addition (via photopolymerization or printing) of most classes of materials using the same equipment in many cases. The versatility provided by these multi-function, multi-material and multi-scale laser micro-manufacturing processes cannot be matched by photolithography nor with other direct-write microfabrication techniques and offer unique opportunities for current and future 3D micro-manufacturing applications.

  12. Point scanning confocal microscopy facilitates 3D human hair follicle imaging in tissue sections.

    PubMed

    Kloepper, Jennifer E; Bíró, Tamás; Paus, Ralf; Cseresnyés, Zoltán

    2010-07-01

    Efficiency is a key factor in determining whether a scientific method becomes widely accepted in practical applications. In dermatology, morphological characterisation of intact hair follicles by traditional methods can be rather inefficient. Samples are embedded, sliced, imaged and digitally reconstructed, which can be time-consuming. Confocal microscopy, on the other hand, is more efficient and readily applicable to study intact hair follicles. Modern confocal microscopes deliver and collect light very efficiently and thus allow high spatial resolution imaging of relatively thick samples. In this letter, we report that we successfully imaged entire intact human hair follicles using point scanning confocal microscopy. Light delivery and light-collection were further improved by preparing the samples in 2,2'-Thiodiethanol (TDE), thus reducing refractive index gradients. The relatively short total scan times and the high quality of the acquired 3D images make confocal microscopy a desirable method for studying intact hair follicles under normal and pathological conditions.

  13. Slate characterization using 3D laser scanning

    NASA Astrophysics Data System (ADS)

    López, M.; Taboada, J.; Martínez, J.; Matías, J. M.; Vilán, J. A.

    2012-12-01

    Quality control is a necessary component of the slate slab manufacturing process so as to evaluate defects as defined by the current standard for slate. Quality control has traditionally been performed manually by an expert in the field, with the consequent human subjectivity. We studied the feasibility of using a 3D laser scanner to measure slate slabs and analyze possible defects that would lead to the rejection of slabs for particular industrial processes. The application requires slate characterization to be performed in real time and thereby requires a short computation time. We describe an optimized calibration method based on Tsai's approach that reduces calculation complexity and cost in this key 3D laser scanning stage. Configured and implemented for slate slab characterization, the system produces the required information in real time during the production process.

  14. Laser processing in 3D diamond detectors

    NASA Astrophysics Data System (ADS)

    Murphy, S. A.; Booth, M.; Li, L.; Oh, A.; Salter, P.; Sun, B.; Whitehead, D.; Zadoroshnyj, A.

    2017-02-01

    A technique for electrode production within diamond using a femtosecond laser system is described. Diagnosis tests to quantify the stress, the diamond to graphite ratio, and the resistivity of these electrodes are discussed. A 3D electronic grade single crystal diamond detector produced using this technique is shown, and the electrodes have a resistivity of O(1 Ω cm). An improvement to the technique through the use of an adaptive wavefront shows a reduction of the diamond to graphite ratio, and smaller, higher quality electrodes were manufactured.

  15. Confocal Microscopy of thick tissue sections: 3D Visualization of rat kidney glomeruli

    EPA Science Inventory

    Confocal laser scanning microscopy (CLSM) as a technique capable of generating serial sections of whole-mount tissue and then reassembling the computer-acquired images as a virtual 3-dimentional structure. In many ways CLSM offers an alternative to traditional sectioning approac...

  16. Confocal microscopy of thick tissue sections: 3D visualizaiton of rat kidney glomeruli

    EPA Science Inventory

    Confocal laser scanning microscopy (CLSM) as a technique capable of generating serial sections of whole-mount tissue and then reassembling the computer-acquired images as a virtual 3-dimentional structure. In many ways CLSM offers an alternative to traditional sectioning approac...

  17. Automated identification of neurons in 3D confocal datasets from zebrafish brainstem

    PubMed Central

    KAMALI, M.; DAY, L. J.; BROOKS, D. H.; ZHOU, X.; O’MALLEY, D. M.

    2009-01-01

    Summary Many kinds of neuroscience data are being acquired regarding the dynamic behaviour and phenotypic diversity of nerve cells. But as the size, complexity and numbers of 3D neuroanatomical datasets grow ever larger, the need for automated detection and analysis of individual neurons takes on greater importance. We describe here a method that detects and identifies neurons within confocal image stacks acquired from the zebrafish brainstem. The first step is to create a template that incorporates the location of all known neurons within a population – in this case the population of reticulospinal cells. Once created, the template is used in conjunction with a sequence of algorithms to determine the 3D location and identity of all fluorescent neurons in each confocal dataset. After an image registration step, neurons are segmented within the confocal image stack and subsequently localized to specific locations within the brainstem template – in many instances identifying neurons as specific, individual reticulospinal cells. This image-processing sequence is fully automated except for the initial selection of three registration points on a maximum projection image. In analysing confocal image stacks that ranged considerably in image quality, we found that this method correctly identified on average ~80% of the neurons (if we assume that manual detection by experts constitutes ‘ground truth’). Because this identification can be generated approximately 100 times faster than manual identification, it offers a considerable time savings for the investigation of zebrafish reticulospinal neurons. In addition to its cell identification function, this protocol might also be integrated with stereological techniques to enhance quantification of neurons in larger databases. Our focus has been on zebrafish brainstem systems, but the methods described should be applicable to diverse neural architectures including retina, hippocampus and cerebral cortex. PMID:19196418

  18. Comparison of 3D Orientation Distribution Functions Measured with Confocal Microscopy and Diffusion MRI

    PubMed Central

    Schilling, Kurt; Janve, Vaibhav; Gao, Yurui; Stepniewska, Iwona; Landman, Bennett A; Anderson, Adam W

    2016-01-01

    The ability of diffusion MRI (dMRI) fiber tractography to non-invasively map three-dimensional (3D) anatomical networks in the human brain has made it a valuable tool in both clinical and research settings. However, there are many assumptions inherent to any tractography algorithm that can limit the accuracy of the reconstructed fiber tracts. Among them is the assumption that the diffusion-weighted images accurately reflect the underlying fiber orientation distribution (FOD) in the MRI voxel. Consequently, validating dMRI’s ability to assess the underlying fiber orientation in each voxel is critical for its use as a biomedical tool. Here, using post-mortem histology and confocal microscopy, we present a method to perform histological validation of orientation functions in 3D, which has previously been limited to two-dimensional analysis of tissue sections. We demonstrate the ability to extract the 3D FOD from confocal z-stacks, and quantify the agreement between the MRI estimates of orientation information obtained using constrained spherical deconvolution (CSD) and the true geometry of the fibers. We find an orientation error of approximately 6° in voxels containing nearly parallel fibers, and 10-11° in crossing fiber regions, and note that CSD was unable to resolve fibers crossing at angles below 60° in our dataset. This is the first time the 3D white matter orientation distribution is calculated from histology and compared to dMRI. Thus, this technique serves as a gold standard for dMRI validation studies - providing the ability to determine the extent to which the dMRI signal is consistent with the histological FOD, and to establish how well different dMRI models can predict the ground truth FOD. PMID:26804781

  19. The three-dimensional elemental distribution based on the surface topography by confocal 3D-XRF analysis

    NASA Astrophysics Data System (ADS)

    Yi, Longtao; Qin, Min; Wang, Kai; Lin, Xue; Peng, Shiqi; Sun, Tianxi; Liu, Zhiguo

    2016-09-01

    Confocal three-dimensional micro-X-ray fluorescence (3D-XRF) is a good surface analysis technology widely used to analyse elements and elemental distributions. However, it has rarely been applied to analyse surface topography and 3D elemental mapping in surface morphology. In this study, a surface adaptive algorithm using the progressive approximation method was designed to obtain surface topography. A series of 3D elemental mapping analyses in surface morphology were performed in laboratories to analyse painted pottery fragments from the Majiayao Culture (3300-2900 BC). To the best of our knowledge, for the first time, sample surface topography and 3D elemental mapping were simultaneously obtained. Besides, component and depth analyses were also performed using synchrotron radiation confocal 3D-XRF and tabletop confocal 3D-XRF, respectively. The depth profiles showed that the sample has a layered structure. The 3D elemental mapping showed that the red pigment, black pigment, and pottery coat contain a large amount of Fe, Mn, and Ca, respectively. From the 3D elemental mapping analyses at different depths, a 3D rendering was obtained, clearly showing the 3D distributions of the red pigment, black pigment, and pottery coat. Compared with conventional 3D scanning, this method is time-efficient for analysing 3D elemental distributions and hence especially suitable for samples with non-flat surfaces.

  20. The relaxed confocal scanning laser ophthalmoscope.

    PubMed

    Van de Velde, F J

    2006-01-01

    The development of the Scanning Laser Ophthalmoscope is reviewed from a historical perspective. Since a flying-spot scanning principle for an electro-optical ophthalmoscope was first disclosed in 1950, enabling milestones have included the introduction of the laser and inversion of the usual Gullstrand's configuration of optical pupils in 1977, and the application of the optical principle of confocality by means of double or de-scanning in 1983. As a result, high resolution and high contrast confocal infra-red ophthalmoscopy with a 790 nm diode laser, at video rates, is a major novel imaging modality when compared to traditional optical techniques. This imaging mode is ideal to provide the necessary fiducial landmarks for microperimetry, therapeutic laser and SD-OCT based optical sectioning of the retina. DPSS or He-Ne lasers emitting at 532, 543, 561 or 575 nm are used for complimentary red-free fundus imaging. The diode 790 nm and DPSS 490 nm lasers are also used for fluorescence excitation.

  1. 3D scene reconstruction based on 3D laser point cloud combining UAV images

    NASA Astrophysics Data System (ADS)

    Liu, Huiyun; Yan, Yangyang; Zhang, Xitong; Wu, Zhenzhen

    2016-03-01

    It is a big challenge capturing and modeling 3D information of the built environment. A number of techniques and technologies are now in use. These include GPS, and photogrammetric application and also remote sensing applications. The experiment uses multi-source data fusion technology for 3D scene reconstruction based on the principle of 3D laser scanning technology, which uses the laser point cloud data as the basis and Digital Ortho-photo Map as an auxiliary, uses 3DsMAX software as a basic tool for building three-dimensional scene reconstruction. The article includes data acquisition, data preprocessing, 3D scene construction. The results show that the 3D scene has better truthfulness, and the accuracy of the scene meet the need of 3D scene construction.

  2. 3D optical sectioning with a new hyperspectral confocal fluorescence imaging system.

    SciTech Connect

    Nieman, Linda T.; Sinclair, Michael B.; Davidson, George S.; Van Benthem, Mark Hilary; Haaland, David Michael; Timlin, Jerilyn Ann; Sasaki, Darryl Yoshio; Bachand, George David; Jones, Howland D. T.

    2007-02-01

    A novel hyperspectral fluorescence microscope for high-resolution 3D optical sectioning of cells and other structures has been designed, constructed, and used to investigate a number of different problems. We have significantly extended new multivariate curve resolution (MCR) data analysis methods to deconvolve the hyperspectral image data and to rapidly extract quantitative 3D concentration distribution maps of all emitting species. The imaging system has many advantages over current confocal imaging systems including simultaneous monitoring of numerous highly overlapped fluorophores, immunity to autofluorescence or impurity fluorescence, enhanced sensitivity, and dramatically improved accuracy, reliability, and dynamic range. Efficient data compression in the spectral dimension has allowed personal computers to perform quantitative analysis of hyperspectral images of large size without loss of image quality. We have also developed and tested software to perform analysis of time resolved hyperspectral images using trilinear multivariate analysis methods. The new imaging system is an enabling technology for numerous applications including (1) 3D composition mapping analysis of multicomponent processes occurring during host-pathogen interactions, (2) monitoring microfluidic processes, (3) imaging of molecular motors and (4) understanding photosynthetic processes in wild type and mutant Synechocystis cyanobacteria.

  3. MEMS-BASED 3D CONFOCAL SCANNING MICROENDOSCOPE USING MEMS SCANNERS FOR BOTH LATERAL AND AXIAL SCAN

    PubMed Central

    Liu, Lin; Wang, Erkang; Zhang, Xiaoyang; Liang, Wenxuan; Li, Xingde; Xie, Huikai

    2014-01-01

    A fiber-optic 3D confocal scanning microendoscope employing MEMS scanners for both lateral and axial scan was designed and constructed. The MEMS 3D scan engine achieved a lateral scan range of over ± 26° with a 2D MEMS scanning micromirror and a depth scan of over 400 μm with a 1D MEMS tunable microlens. The lateral resolution and axial resolution of this system were experimentally measured as 1.0 μm and 7.0 μm, respectively. 2D and 3D confocal reflectance images of micro-patterns, micro-particles, onion skins and acute rat brain tissue were obtained by this MEMS-based 3D confocal scanning microendoscope. PMID:25013304

  4. 3D-confocal microscopy for surface analysis of microstructured materials

    NASA Astrophysics Data System (ADS)

    Kagerer, Bernd; Brodmann, Rainer; Valentin, Juergen; Filzek, Jan; Popp, Uwe

    2002-06-01

    The surface of technical materials is playing an ever more important part in modern production processes. However, standard roughness values, which are obtained from a profile, frequently no longer provide sufficient descriptions. What are desired are three-dimensional measurements of surfaces over a macroscopic range with a high degree of vertical and lateral resolution. This has become necessary to be able to describe both deterministic and non-deterministic structures in the same fashion. Due to increased requirements for data and the measuring speed demanded by industry, only optical systems are a possibility. Using the example of tribology, the capability of this technology is shown in this article on the basis of the commercial confocal 3D white light microscope, the NanoFocusTMμSurfTM. On the one hand, the technology and data preparation used are discussed, and on the other, a comparison is drawn with other standard optical measuring methods.

  5. Automated 3-D tracking of centrosomes in sequences of confocal image stacks.

    PubMed

    Kerekes, Ryan A; Gleason, Shaun S; Trivedi, Niraj; Solecki, David J

    2009-01-01

    In order to facilitate the study of neuron migration, we propose a method for 3-D detection and tracking of centrosomes in time-lapse confocal image stacks of live neuron cells. We combine Laplacian-based blob detection, adaptive thresholding, and the extraction of scale and roundness features to find centrosome-like objects in each frame. We link these detections using the joint probabilistic data association filter (JPDAF) tracking algorithm with a Newtonian state-space model tailored to the motion characteristics of centrosomes in live neurons. We apply our algorithm to image sequences containing multiple cells, some of which had been treated with motion-inhibiting drugs. We provide qualitative results and quantitative comparisons to manual segmentation and tracking results showing that our average motion estimates agree to within 13% of those computed manually by neurobiologists.

  6. Automatic segmentation and analysis of fibrin networks in 3D confocal microscopy images

    NASA Astrophysics Data System (ADS)

    Liu, Xiaomin; Mu, Jian; Machlus, Kellie R.; Wolberg, Alisa S.; Rosen, Elliot D.; Xu, Zhiliang; Alber, Mark S.; Chen, Danny Z.

    2012-02-01

    Fibrin networks are a major component of blood clots that provides structural support to the formation of growing clots. Abnormal fibrin networks that are too rigid or too unstable can promote cardiovascular problems and/or bleeding. However, current biological studies of fibrin networks rarely perform quantitative analysis of their structural properties (e.g., the density of branch points) due to the massive branching structures of the networks. In this paper, we present a new approach for segmenting and analyzing fibrin networks in 3D confocal microscopy images. We first identify the target fibrin network by applying the 3D region growing method with global thresholding. We then produce a one-voxel wide centerline for each fiber segment along which the branch points and other structural information of the network can be obtained. Branch points are identified by a novel approach based on the outer medial axis. Cells within the fibrin network are segmented by a new algorithm that combines cluster detection and surface reconstruction based on the α-shape approach. Our algorithm has been evaluated on computer phantom images of fibrin networks for identifying branch points. Experiments on z-stack images of different types of fibrin networks yielded results that are consistent with biological observations.

  7. Advances in automated 3-D image analyses of cell populations imaged by confocal microscopy.

    PubMed

    Ancin, H; Roysam, B; Dufresne, T E; Chestnut, M M; Ridder, G M; Szarowski, D H; Turner, J N

    1996-11-01

    Automated three-dimensional (3-D) image analysis methods are presented for rapid and effective analysis of populations of fluorescently labeled cells or nuclei in thick tissue sections that have been imaged three dimensionally using a confocal microscope. The methods presented here greatly improve upon our earlier work (Roysam et al.:J Microsc 173: 115-126, 1994). The principal advances reported are: algorithms for efficient data pre-processing and adaptive segmentation, effective handling of image anisotrophy, and fast 3-D morphological algorithms for separating overlapping or connected clusters utilizing image gradient information whenever available. A particular feature of this method is its ability to separate densely packed and connected clusters of cell nuclei. Some of the challenges overcome in this work include the efficient and effective handling of imaging noise, anisotrophy, and large variations in image parameters such as intensity, object size, and shape. The method is able to handle significant inter-cell, intra-cell, inter-image, and intra-image variations. Studies indicate that this method is rapid, robust, and adaptable. Examples were presented to illustrate the applicability of this approach to analyzing images of nuclei from densely packed regions in thick sections of rat liver, and brain that were labeled with a fluorescent Schiff reagent.

  8. Automatic analysis for neuron by confocal laser scanning microscope

    NASA Astrophysics Data System (ADS)

    Satou, Kouhei; Aoki, Yoshimitsu; Mataga, Nobuko; Hensh, Takao K.; Taki, Katuhiko

    2005-12-01

    The aim of this study is to develop a system that recognizes both the macro- and microscopic configurations of nerve cells and automatically performs the necessary 3-D measurements and functional classification of spines. The acquisition of 3-D images of cranial nerves has been enabled by the use of a confocal laser scanning microscope, although the highly accurate 3-D measurements of the microscopic structures of cranial nerves and their classification based on their configurations have not yet been accomplished. In this study, in order to obtain highly accurate measurements of the microscopic structures of cranial nerves, existing positions of spines were predicted by the 2-D image processing of tomographic images. Next, based on the positions that were predicted on the 2-D images, the positions and configurations of the spines were determined more accurately by 3-D image processing of the volume data. We report the successful construction of an automatic analysis system that uses a coarse-to-fine technique to analyze the microscopic structures of cranial nerves with high speed and accuracy by combining 2-D and 3-D image analyses.

  9. Overview of 3D laser materials processing concepts

    NASA Astrophysics Data System (ADS)

    Tsoukantas, George; Salonitis, Konstantinos; Stavropoulos, Panagiotis; Chryssolouris, George

    2003-04-01

    The term of 3D laser processing has been used so far to describe a group of different three-dimensional laser processing concepts. At each of these concepts the 3D aspect refers to a different manipulation of one or more laser beams, as to process and/or produce three-dimensional geometries by performing material removal, welding or heat treating. The most important concepts are focused mainly in laser machining and laser welding processes by incorporating one or two laser beams simultaneously. This paper overviews a number of these concepts that have been developed in research or industrial level, along with their advantages, drawbacks and fields of application.

  10. Oscillating optical tweezer-based 3-D confocal microrheometer for investigating the intracellular micromechanics and structures

    NASA Astrophysics Data System (ADS)

    Ou-Yang, H. D.; Rickter, E. A.; Pu, C.; Latinovic, O.; Kumar, A.; Mengistu, M.; Lowe-Krentz, L.; Chien, S.

    2005-08-01

    Mechanical properties of living biological cells are important for cells to maintain their shapes, support mechanical stresses and move through tissue matrix. The use of optical tweezers to measure micromechanical properties of cells has recently made significant progresses. This paper presents a new approach, the oscillating optical tweezer cytorheometer (OOTC), which takes advantage of the coherent detection of harmonically modulated particle motions by a lock-in amplifier to increase sensitivity, temporal resolution and simplicity. We demonstrate that OOTC can measure the dynamic mechanical modulus in the frequency range of 0.1-6,000 Hz at a rate as fast as 1 data point per second with submicron spatial resolution. More importantly, OOTC is capable of distinguishing the intrinsic non-random temporal variations from random fluctuations due to Brownian motion; this capability, not achievable by conventional approaches, is particular useful because living systems are highly dynamic and often exhibit non-thermal, rhythmic behavior in a broad time scale from a fraction of a second to hours or days. Although OOTC is effective in measuring the intracellular micromechanical properties, unless we can visualize the cytoskeleton in situ, the mechanical property data would only be as informative as that of "Blind men and the Elephant". To solve this problem, we take two steps, the first, to use of fluorescent imaging to identify the granular structures trapped by optical tweezers, and second, to integrate OOTC with 3-D confocal microscopy so we can take simultaneous, in situ measurements of the micromechanics and intracellular structure in living cells. In this paper, we discuss examples of applying the oscillating tweezer-based cytorheometer for investigating cultured bovine endothelial cells, the identification of caveolae as some of the granular structures in the cell as well as our approach to integrate optical tweezers with a spinning disk confocal microscope.

  11. Confocal fluorometer for diffusion tracking in 3D engineered tissue constructs

    NASA Astrophysics Data System (ADS)

    Daly, D.; Zilioli, A.; Tan, N.; Buttenschoen, K.; Chikkanna, B.; Reynolds, J.; Marsden, B.; Hughes, C.

    2016-03-01

    We present results of the development of a non-contacting instrument, called fScan, based on scanning confocal fluorometry for assessing the diffusion of materials through a tissue matrix. There are many areas in healthcare diagnostics and screening where it is now widely accepted that the need for new quantitative monitoring technologies is a major pinch point in patient diagnostics and in vitro testing. With the increasing need to interpret 3D responses this commonly involves the need to track the diffusion of compounds, pharma-active species and cells through a 3D matrix of tissue. Methods are available but to support the advances that are currently only promised, this monitoring needs to be real-time, non-invasive, and economical. At the moment commercial meters tend to be invasive and usually require a sample of the medium to be removed and processed prior to testing. This methodology clearly has a number of significant disadvantages. fScan combines a fiber based optical arrangement with a compact, free space optical front end that has been integrated so that the sample's diffusion can be measured without interference. This architecture is particularly important due to the "wet" nature of the samples. fScan is designed to measure constructs located within standard well plates and a 2-D motion stage locates the required sample with respect to the measurement system. Results are presented that show how the meter has been used to evaluate movements of samples through collagen constructs in situ without disturbing their kinetic characteristics. These kinetics were little understood prior to these measurements.

  12. Jamming of a soft granular system of hollow elastic shells in 3D using confocal microscopy

    NASA Astrophysics Data System (ADS)

    Jose, Jissy; van Blaaderen, Alfons; Imhof, Arnout

    2014-03-01

    We introduce a new system for jammed matter research consisting of monodisperse, fluorescent, hollow deformable shells, dispersed in an index matched solvent. The interesting fact about these elastic shells is that they undergo buckling: in each contact one of the shells receives an indentation from its neighbor under compressive stress. This kind of deformation is different from the soft granular systems experimentally studied so far like photo elastic disks, emulsions and foams, where the particles are flattened in the region of contact and conserve their volume. Using confocal microscopy and image analysis routines (ImageJ software) we identified the 3D position of the particles with sub pixel resolution. The force law to find the contact forces between pairs of particle is derived from the theory of elasticity of thin shells, where force is proportional to the square root of indentation depth. The distribution of normalized contact forces showed a similar trend like other jammed systems with a peak around the mean and a tail that decayed faster than exponential away from jamming threshold. Further, we also investigated the structure of the jammed packings and contact number distribution with distance to jamming.

  13. Streaming level set algorithm for 3D segmentation of confocal microscopy images.

    PubMed

    Gouaillard, Alexandre; Mosaliganti, Kishore; Gelas, Arnaud; Souhait, Lydie; Obholzer, Nikolaus; Megason, Sean

    2009-01-01

    We present a high performance variant of the popular geodesic active contours which are used for splitting cell clusters in microscopy images. Previously, we implemented a linear pipelined version that incorporates as many cues as possible into developing a suitable level-set speed function so that an evolving contour exactly segments a cell/nuclei blob. We use image gradients, distance maps, multiple channel information and a shape model to drive the evolution. We also developed a dedicated seeding strategy that uses the spatial coherency of the data to generate an over complete set of seeds along with a quality metric which is further used to sort out which seed should be used for a given cell. However, the computational performance of any level-set methodology is quite poor when applied to thousands of 3D data-sets each containing thousands of cells. Those data-sets are common in confocal microscopy. In this work, we explore methods to stream the algorithm in shared memory, multi-core environments. By partitioning the input and output using spatial data structures we insure the spatial coherency needed by our seeding algorithm as well as improve drastically the speed without memory overhead. Our results show speed-ups up to a factor of six.

  14. 3D Laser Scanning in Technology Education.

    ERIC Educational Resources Information Center

    Flowers, Jim

    2000-01-01

    A three-dimensional laser scanner can be used as a tool for design and problem solving in technology education. A hands-on experience can enhance learning by captivating students' interest and empowering them with creative tools. (Author/JOW)

  15. 3D laser imaging for concealed object identification

    NASA Astrophysics Data System (ADS)

    Berechet, Ion; Berginc, Gérard; Berechet, Stefan

    2014-09-01

    This paper deals with new optical non-conventional 3D laser imaging. Optical non-conventional imaging explores the advantages of laser imaging to form a three-dimensional image of the scene. 3D laser imaging can be used for threedimensional medical imaging, topography, surveillance, robotic vision because of ability to detect and recognize objects. In this paper, we present a 3D laser imaging for concealed object identification. The objective of this new 3D laser imaging is to provide the user a complete 3D reconstruction of the concealed object from available 2D data limited in number and with low representativeness. The 2D laser data used in this paper come from simulations that are based on the calculation of the laser interactions with the different interfaces of the scene of interest and from experimental results. We show the global 3D reconstruction procedures capable to separate objects from foliage and reconstruct a threedimensional image of the considered object. In this paper, we present examples of reconstruction and completion of three-dimensional images and we analyse the different parameters of the identification process such as resolution, the scenario of camouflage, noise impact and lacunarity degree.

  16. A 3D imaging and visualization workflow, using confocal microscopy and advanced image processing for brachyuran crab larvae.

    PubMed

    Kamanli, S A; Kihara, T C; Ball, A D; Morritt, D; Clark, P F

    2017-03-07

    Confocal laser scanning microscopy is an excellent tool for nondestructive imaging of arthropods and can provide detailed information on morphology including fine surface detail. A methodology is presented here for the visualization by confocal microscopy of arthropods, using brachyuran crab zoeal stages as examples and postprocessing techniques derived from micro-CT protocols to improve the final images. This protocol is divided into description of the preprocessing steps (cleaning, staining, digesting and mounting), confocal laser scanning microscopy and data visualization using open-source, freeware programs ImageJ and Drishti. The advantages of using ImageJ to standardize stack data and Drishti for surface rendering are discussed. The methodology has been comprehensively tested using data acquired from all four brands of confocal microscope (Leica, Nikon, Olympus and Zeiss).

  17. CONFOCAL LASER SCANNING MICROSCOPY OF RAT FOLLICLE DEVELOPMENT

    EPA Science Inventory

    This study used confocal laser scanning microscopy (CLSM) to study follicular development in millimeter pieces of rat ovary. To use this technology, it is essential to stain the tissue before laser excitation with the confocal microscope. Various fluorescent stains (Yo-Pro, Bo-Pr...

  18. Imaging Single ZnO Vertical Nanowire Laser Cavities using UV-Laser Scanning Confocal Microscopy

    SciTech Connect

    Gargas, D.J.; Toimil-Molares, M.E.; Yang, P.

    2008-11-17

    We report the fabrication and optical characterization of individual ZnO vertical nanowire laser cavities. Dilute nanowire arrays with interwire spacing>10 ?m were produced by a modified chemical vapor transport (CVT) method yielding an ideal platform for single nanowire imaging and spectroscopy. Lasing characteristics of a single vertical nanowire are presented, as well as high-resolution photoluminescence imaging by UV-laser scanning confocal microscopy. In addition, three-dimensional (3D) mapping of the photoluminescence emission performed in both planar and vertical dimensions demonstrates height-selective imaging useful for vertical nanowires and heteronanostructures emerging in the field of optoelectronics and nanophotonics.

  19. Segmentation of densely populated cell nuclei from confocal image stacks using 3D non-parametric shape priors.

    PubMed

    Ong, Lee-Ling S; Wang, Mengmeng; Dauwels, Justin; Asada, H Harry

    2014-01-01

    An approach to jointly estimate 3D shapes and poses of stained nuclei from confocal microscopy images, using statistical prior information, is presented. Extracting nuclei boundaries from our experimental images of cell migration is challenging due to clustered nuclei and variations in their shapes. This issue is formulated as a maximum a posteriori estimation problem. By incorporating statistical prior models of 3D nuclei shapes into level set functions, the active contour evolutions applied on the images is constrained. A 3D alignment algorithm is developed to build the training databases and to match contours obtained from the images to them. To address the issue of aligning the model over multiple clustered nuclei, a watershed-like technique is used to detect and separate clustered regions prior to active contour evolution. Our method is tested on confocal images of endothelial cells in microfluidic devices, compared with existing approaches.

  20. A handheld laser scanning confocal reflectance imaging–confocal Raman microspectroscopy system

    PubMed Central

    Patil, Chetan A.; Arrasmith, Christopher L.; Mackanos, Mark A.; Dickensheets, David L.; Mahadevan-Jansen, Anita

    2012-01-01

    Confocal reflectance microscopy and confocal Raman spectroscopy have shown potential for non-destructive analysis of samples at micron-scale resolutions. Current studies utilizing these techniques often employ large bench-top microscopes, and are not suited for use outside of laboratory settings. We have developed a microscope which combines laser scanning confocal reflectance imaging and confocal Raman spectroscopy into a compact handheld probe that is capable of high-resolution imaging and spectroscopy in a variety of settings. The compact size of the probe is largely due to the use of a MEMS mirror for beam scanning. The probe is capable of axial resolutions of up to 4 μm for the confocal imaging channel and 10 μm for the confocal Raman spectroscopy channel. Here, we report instrument design, characterize optical performance, and provide images and spectra from normal skin to demonstrate the instrument’s capabilities for clinical diagnostics. PMID:22435097

  1. A linear programming approach to reconstructing subcellular structures from confocal images for automated generation of representative 3D cellular models.

    PubMed

    Wood, Scott T; Dean, Brian C; Dean, Delphine

    2013-04-01

    This paper presents a novel computer vision algorithm to analyze 3D stacks of confocal images of fluorescently stained single cells. The goal of the algorithm is to create representative in silico model structures that can be imported into finite element analysis software for mechanical characterization. Segmentation of cell and nucleus boundaries is accomplished via standard thresholding methods. Using novel linear programming methods, a representative actin stress fiber network is generated by computing a linear superposition of fibers having minimum discrepancy compared with an experimental 3D confocal image. Qualitative validation is performed through analysis of seven 3D confocal image stacks of adherent vascular smooth muscle cells (VSMCs) grown in 2D culture. The presented method is able to automatically generate 3D geometries of the cell's boundary, nucleus, and representative F-actin network based on standard cell microscopy data. These geometries can be used for direct importation and implementation in structural finite element models for analysis of the mechanics of a single cell to potentially speed discoveries in the fields of regenerative medicine, mechanobiology, and drug discovery.

  2. Needle-based confocal laser endomicroscopy

    PubMed Central

    Giovannini, Marc

    2015-01-01

    New applications of confocal laser endomicroscopy were developed as pCLE in the bile duct and nCLE for pancreatic cystic tumors, pancreatic masses and lymph nodes. The aim of this paper would be to give you an update in this new technology and to try to define its place in the diagnosis of cystic and solid pancreatic masses. The material used was a 19G EUS-needle in which the stylet was replaced by the Confocal mini-probe. The mini-probe (0.632 mm of diameter) is pre-loaded and screwed by a locking device in the EUS-Needle and guided endosonographically in the target. Regarding pancreatic cystic lesion, the presence of epithelial villous structures based on nCLE was associated with pancreatic cystic neoplasm (IPMN) (P = 0.004) and provided a sensitivity of 59%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 50%. A superficial vascular network pattern visualized on nCLE was identified in serous cystadenomas. It corresponded on pathological specimen to a dense and subepithelial capillary vascularization. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of this sign for the diagnosis of SCA were 87%, 69%, 100%, 100%, and 82%, respectively. In pancreatic adenocarcinomas, nCLE found vascular leakage with irregular vessels with leakage of fluorescein into the tumor, large dark clumps which correspond to humps of malignant cells. These criteria correlate with the histological structure of those tumors which are characterized by tumoral glands, surrounded by fibrosis in case of fibrous stroma tumor. Neuroendocrine tumors showed a dense network of small vessels on a dark background, which fits with the histological structure based on cord of cells surrounded by vessels and by fibrosis. nCLE is feasible during a EUS examination; these preliminary results are very encouraging and may be used in the future in case of inconclusive EUS-FNA. PMID:26643694

  3. A semi-automatic 3D laser scan system design

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Pan, Ming; Zhang, Xiangwei

    2009-11-01

    Digital 3D models are now used everywhere, from traditional fields of industrial design, artistic design, to heritage conservation. Although laser scan is very useful to get densely samples of the objects, nowadays, such an instrument is expensive and always need to be connected to a computer with stable power supply, which prevent it from usage for fieldworks. In this paper, a new semi-automatic 3D laser scan method is proposed using two line laser sources. The planes projected from the laser sources are orthogonal, one of which is fixed relative to the camera, and the other can be rotated along a settled axis. Before scanning, the system must be calibrated, from which the parameters of the camera, the position of the fixed laser plane and the settled axis are introduced. In scanning process, the fixed laser plane and the camera form a conventional structured light system, and the 3d positions of the intersection curves of the fixed laser plane with the object can be computed. The other laser plane is rotated manually or mechanically, and its position can be determined from the cross point intersecting with the fixed laser plane on the object, so the coordinates of sweeping points can be obtained. The new system can be used without a computer (The data can be processed later), which make it suitable for fieldworks. A scanning case is given in the end.

  4. Innovative simultaneous confocal full-field 3D surface profilometry for in situ automatic optical inspection (AOI)

    NASA Astrophysics Data System (ADS)

    Chen, Liang-Chia; Chang, Yi-Wei

    2010-06-01

    Rapid acquisition of surface 3D contour information using optical detection has attracted tremendous interest in the field of automatic optical inspection (AOI) and how to avoid or minimize environmental vibration or disturbance has become a critical issue in in situ inspection. Owing to its high longitudinal measurability and excellent vertical resolution, optical confocal microscopy has become extremely important for surface profilometry. This study presents a novel simultaneous confocal full-field 3D surface profilometer using structured fringe projection. The developed confocal optical system is capable of acquiring multiple images at various object depths to perform surface 3D reconstruction by a single image shot without the need for time-consuming vertical scanning. In this method, four conjugate image-sensing modules are configured at four different designated focusing positions, which are controlled by a specially designed beam-splitting optical module. A focal-depth response (FDR) curve can be established by fitting the four focus measurements obtained from these designated positions to achieve simultaneous confocal vertical scanning. In addition, using the principle of optical grating projection, a structured fringe pattern is generated for lateral scanning to enhance the spatial measurement resolution. To examine the performance of the developed system, an accurate step-height target and some industrial micro semiconductor components were measured. The results show that the depth measurement resolution can reach up to 0.1 µm and the maximum measurement error is within 1.5% of the overall range, indicating both accuracy and repeatability of the proposed confocal measurement approach.

  5. 3D Lasers Increase Efficiency, Safety of Moving Machines

    NASA Technical Reports Server (NTRS)

    2015-01-01

    Canadian company Neptec Design Group Ltd. developed its Laser Camera System, used by shuttles to render 3D maps of their hulls for assessing potential damage. Using NASA funding, the firm incorporated LiDAR technology and created the TriDAR 3D sensor. Its commercial arm, Neptec Technologies Corp., has sold the technology to Orbital Sciences, which uses it to guide its Cygnus spacecraft during rendezvous and dock operations at the International Space Station.

  6. Laser origami: a new technique for assembling 3D microstructures

    NASA Astrophysics Data System (ADS)

    Piqué, Alberto; Mathews, Scott A.; Charipar, Nicholas A.; Birnbaum, Andrew J.

    2012-03-01

    The ability to manufacture and assemble complex three-dimensional (3D) systems via traditional photolithographic techniques has attracted increasing attention. However, most of the work to date still utilizes the traditional patterning and etching processes designed for the semiconductor industry where 2D structures are first fabricated, followed by some alternative technique for releasing these structures out-of-plane. Here we present a novel technique called Laser Origami, which has demonstrated the ability to generate 3D microstructures through the controlled out-of-plane folding of 2D patterns. This non-lithographic, and non silicon-based process is capable of microfabricating 3D structures of arbitrary shape and geometric complexity on a variety of substrates. The Laser Origami technique allows for the design and fabrication of arrays of 3D microstructures, where each microstructure can be made to fold independently of the others. Application of these folded micro-assemblies might make possible the development of highly complex and interconnected electrical, optical and mechanical 3D systems. This article will describe the unique advantages and capabilities of Laser Origami, discuss its applications and explore its role for the assembly and generation of 3D microstructures.

  7. Detection of latent fingerprints using high-resolution 3D confocal microscopy in non-planar acquisition scenarios

    NASA Astrophysics Data System (ADS)

    Kirst, Stefan; Vielhauer, Claus

    2015-03-01

    In digitized forensics the support of investigators in any manner is one of the main goals. Using conservative lifting methods, the detection of traces is done manually. For non-destructive contactless methods, the necessity for detecting traces is obvious for further biometric analysis. High resolutional 3D confocal laser scanning microscopy (CLSM) grants the possibility for a detection by segmentation approach with improved detection results. Optimal scan results with CLSM are achieved on surfaces orthogonal to the sensor, which is not always possible due to environmental circumstances or the surface's shape. This introduces additional noise, outliers and a lack of contrast, making a detection of traces even harder. Prior work showed the possibility of determining angle-independent classification models for the detection of latent fingerprints (LFP). Enhancing this approach, we introduce a larger feature space containing a variety of statistical-, roughness-, color-, edge-directivity-, histogram-, Gabor-, gradient- and Tamura features based on raw data and gray-level co-occurrence matrices (GLCM) using high resolutional data. Our test set consists of eight different surfaces for the detection of LFP in four different acquisition angles with a total of 1920 single scans. For each surface and angles in steps of 10, we capture samples from five donors to introduce variance by a variety of sweat compositions and application influences such as pressure or differences in ridge thickness. By analyzing the present test set with our approach, we intend to determine angle- and substrate-dependent classification models to determine optimal surface specific acquisition setups and also classification models for a general detection purpose for both, angles and substrates. The results on overall models with classification rates up to 75.15% (kappa 0.50) already show a positive tendency regarding the usability of the proposed methods for LFP detection on varying surfaces in non

  8. Managing multiple image stacks from confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Zerbe, Joerg; Goetze, Christian H.; Zuschratter, Werner

    1999-05-01

    A major goal in neuroanatomy is to obtain precise information about the functional organization of neuronal assemblies and their interconnections. Therefore, the analysis of histological sections frequently requires high resolution images in combination with an overview about the structure. To overcome this conflict we have previously introduced a software for the automatic acquisition of multiple image stacks (3D-MISA) in confocal laser scanning microscopy. Here, we describe a Windows NT based software for fast and easy navigation through the multiple images stacks (MIS-browser), the visualization of individual channels and layers and the selection of user defined subregions. In addition, the MIS browser provides useful tools for the visualization and evaluation of the datavolume, as for instance brightness and contrast corrections of individual layers and channels. Moreover, it includes a maximum intensity projection, panning and zoom in/out functions within selected channels or focal planes (x/y) and tracking along the z-axis. The import module accepts any tiff-format and reconstructs the original image arrangement after the user has defined the sequence of images in x/y and z and the number of channels. The implemented export module allows storage of user defined subregions (new single image stacks) for further 3D-reconstruction and evaluation.

  9. 3-D laser patterning process utilizing horizontal and vertical patterning

    DOEpatents

    Malba, Vincent; Bernhardt, Anthony F.

    2000-01-01

    A process which vastly improves the 3-D patterning capability of laser pantography (computer controlled laser direct-write patterning). The process uses commercially available electrodeposited photoresist (EDPR) to pattern 3-D surfaces. The EDPR covers the surface of a metal layer conformally, coating the vertical as well as horizontal surfaces. A laser pantograph then patterns the EDPR, which is subsequently developed in a standard, commercially available developer, leaving patterned trench areas in the EDPR. The metal layer thereunder is now exposed in the trench areas and masked in others, and thereafter can be etched to form the desired pattern (subtractive process), or can be plated with metal (additive process), followed by a resist stripping, and removal of the remaining field metal (additive process). This improved laser pantograph process is simpler, faster, move manufacturable, and requires no micro-machining.

  10. The 3D laser radar vision processor system

    NASA Technical Reports Server (NTRS)

    Sebok, T. M.

    1990-01-01

    Loral Defense Systems (LDS) developed a 3D Laser Radar Vision Processor system capable of detecting, classifying, and identifying small mobile targets as well as larger fixed targets using three dimensional laser radar imagery for use with a robotic type system. This processor system is designed to interface with the NASA Johnson Space Center in-house Extra Vehicular Activity (EVA) Retriever robot program and provide to it needed information so it can fetch and grasp targets in a space-type scenario.

  11. CONFOCAL LASER SCANNING MICROSCOPY OF APOPTOSIS IN WHOLE MOUSE OVARIES

    EPA Science Inventory

    Confocal Laser Scanning Microscopy of Apoptosis in Whole Mouse Ovaries. Robert M. Zucker Susan C. Jeffay and Sally D. Perreault Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle...

  12. Precision Control Module For UV Laser 3D Micromachining

    NASA Astrophysics Data System (ADS)

    Wu, Wen-Hong; Hung, Min-Wei; Chang, Chun-Li

    2011-01-01

    UV laser has been widely used in various micromachining such as micro-scribing or patterning processing. At present, most of the semiconductors, LEDs, photovoltaic solar panels and touch panels industries need the UV laser processing system. However, most of the UV laser processing applications in the industries utilize two dimensional (2D) plane processing. And there are tremendous business opportunities that can be developed, such as three dimensional (3D) structures of micro-electromechanical (MEMS) sensor or the precision depth control of indium tin oxide (ITO) thin films edge insulation in touch panels. This research aims to develop a UV laser 3D micromachining module that can create the novel applications for industries. By special designed beam expender in optical system, the focal point of UV laser can be adjusted quickly and accurately through the optical path control lens of laser beam expender optical system. Furthermore, the integrated software for galvanometric scanner and focal point adjustment mechanism is developed as well, so as to carry out the precise 3D microstructure machining.

  13. 3-D Imaging of Partly Concealed Targets by Laser Radar

    DTIC Science & Technology

    2005-10-01

    laser in the green wavelength region was used for illumination. 3-D Imaging of Partly Concealed Targets by Laser Radar 11 - 8 RTO-MP-SET-094...acknowledge Marie Carlsson and Ann Charlotte Gustavsson for their assistance in some of the experiments. 7.0 REFERENCES [1] U. Söderman, S. Ahlberg...SPIE Vol. 3707, pp. 432-448, USA, 1999. [14] D. Letalick, H. Larsson, M. Carlsson, and A.-C. Gustavsson , “Laser sensors for urban warfare,” FOI

  14. Extraction of features from 3D laser scanner cloud data

    NASA Astrophysics Data System (ADS)

    Chan, Vincent H.; Bradley, Colin H.; Vickers, Geoffrey W.

    1997-12-01

    One of the road blocks on the path of automated reverse engineering has been the extraction of useful data from the copious range data generated from 3-D laser scanning systems. A method to extract the relevant features of a scanned object is presented. A 3-D laser scanner is automatically directed to obtain discrete laser cloud data on each separate patch that constitutes the object's surface. With each set of cloud data treated as a separate entity, primitives are fitted to the data resulting in a geometric and topologic database. Using a feed-forewarn neural network, the data is analyzed for geometric combinations that make up machine features such as through holes and slots. These features are required for the reconstruction of the solid model by a machinist or feature based CAM algorithms, thus completing the reverse engineering cycle.

  15. Measurement of Laser Weld Temperatures for 3D Model Input

    SciTech Connect

    Dagel, Daryl; Grossetete, Grant; Maccallum, Danny O.

    2016-10-01

    Laser welding is a key joining process used extensively in the manufacture and assembly of critical components for several weapons systems. Sandia National Laboratories advances the understanding of the laser welding process through coupled experimentation and modeling. This report summarizes the experimental portion of the research program, which focused on measuring temperatures and thermal history of laser welds on steel plates. To increase confidence in measurement accuracy, researchers utilized multiple complementary techniques to acquire temperatures during laser welding. This data serves as input to and validation of 3D laser welding models aimed at predicting microstructure and the formation of defects and their impact on weld-joint reliability, a crucial step in rapid prototyping of weapons components.

  16. Fiber optic coherent laser radar 3D vision system

    SciTech Connect

    Clark, R.B.; Gallman, P.G.; Slotwinski, A.R.; Wagner, K.; Weaver, S.; Xu, Jieping

    1996-12-31

    This CLVS will provide a substantial advance in high speed computer vision performance to support robotic Environmental Management (EM) operations. This 3D system employs a compact fiber optic based scanner and operator at a 128 x 128 pixel frame at one frame per second with a range resolution of 1 mm over its 1.5 meter working range. Using acousto-optic deflectors, the scanner is completely randomly addressable. This can provide live 3D monitoring for situations where it is necessary to update once per second. This can be used for decontamination and decommissioning operations in which robotic systems are altering the scene such as in waste removal, surface scarafacing, or equipment disassembly and removal. The fiber- optic coherent laser radar based system is immune to variations in lighting, color, or surface shading, which have plagued the reliability of existing 3D vision systems, while providing substantially superior range resolution.

  17. Confocal scanning beam laser microscope/macroscope: applications in fluorescence

    NASA Astrophysics Data System (ADS)

    Dixon, Arthur E.; Damaskinos, Savvas; Ribes, Alfonso

    1996-03-01

    A new confocal scanning beam laser microscope/macroscope is described that combines the rapid scan of a scanning beam laser microscope with the large specimen capability of a scanning stage microscope. This instrument combines an infinity-corrected confocal scanning laser microscope with a scanning laser macroscope that uses a telecentric f*(Theta) laser scan lens to produce a confocal imaging system with a resolution of 0.25 microns at a field of view of 25 microns and 5 microns at a field of view of 75,000 microns. The frame rate is 5 seconds per frame for a 512 by 512 pixel image, and 25 seconds for a 2048 by 2048 pixel image. Applications in fluorescence are discussed that focus on two important advantages of the instrument over a confocal scanning laser microscope: an extremely wide range of magnification, and the ability to image very large specimens. Examples are presented of fluorescence and reflected-light images of high quality printing, fluorescence images of latent fingerprints, packaging foam, and confocal autofluorescence images of a cricket.

  18. Fiber optic coherent laser radar 3d vision system

    SciTech Connect

    Sebastian, R.L.; Clark, R.B.; Simonson, D.L.

    1994-12-31

    Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic of coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  19. Diffusion of photoacid generators by laser scanning confocal microscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Ping L.; Webber, Stephen E.; Mendenhall, J.; Byers, Jeffrey D.; Chao, Keith K.

    1998-06-01

    Diffusion of the photogenerated acid during the period of time between exposure and development can cause contrast loss and ultimately loss of the latent image. This is especially relevant for chemically amplified photoresists that require a post-exposure baking step, which in turn facilitates acid diffusion due to the high temperature normally employed. It is thus important to develop techniques with good spatial resolution to monitor the photogeneration of acid. More precisely, we need techniques that provide two distinct types of information: spatial resolution on various length scales within the surface layer and also sufficient depth resolution so that one can observe the transition from very surface layer to bulk structure in the polymer blend coated on silicon substrate. Herein laser scanning confocal microscopy is used to evaluate the resist for the first time. We report the use of the confocal microscopy to map the pag/dye distribution in PHS matrices, with both reflectance images and fluorescence images. A laser beam is focused onto a small 3D volume element, termed a voxel. It is typically 200 nm X 200 nm laterally and 800 nm axially. The illuminated voxel is viewed such that only signals emanating from this voxel are detected, i.e., signal from outside the probed voxel is not detected. By adjusting the vertical position of the laser focal point, the voxel can be moved to the designated lateral plane to produce an image. Contrast caused by topology difference between the exposed and unexposed area can be eliminated. Bis-p-butylphenyl iodonium triflat (7% of polyhydroxystyrene) is used as photoacid generators. 5% - 18% (by weight, PHS Mn equals 13 k) resist in PGMEA solution is spin cast onto the treated quartz disk with thickness of 1.4 micrometers , 5 micrometers space/10 micrometers pitch chrome mask is used to generate the pattern with mercury DUV illumination. Fluoresceinamine, the pH-sensitive dye, is also used to enhance the contrast of

  20. A New Multichannel Spectral Imaging Laser Scanning Confocal Microscope

    PubMed Central

    Zhang, Yunhai; Hu, Bian; Dai, Yakang; Yang, Haomin; Huang, Wei; Xue, Xiaojun; Li, Fazhi; Zhang, Xin; Jiang, Chenyu; Gao, Fei; Chang, Jian

    2013-01-01

    We have developed a new multichannel spectral imaging laser scanning confocal microscope for effective detection of multiple fluorescent labeling in the research of biological tissues. In this paper, the design and key technologies of the system are introduced. Representative results on confocal imaging, 3-dimensional sectioning imaging, and spectral imaging are demonstrated. The results indicated that the system is applicable to multiple fluorescent labeling in biological experiments. PMID:23585775

  1. 3D segmentations of neuronal nuclei from confocal microscope image stacks.

    PubMed

    Latorre, Antonio; Alonso-Nanclares, Lidia; Muelas, Santiago; Peña, José-María; Defelipe, Javier

    2013-01-01

    In this paper, we present an algorithm to create 3D segmentations of neuronal cells from stacks of previously segmented 2D images. The idea behind this proposal is to provide a general method to reconstruct 3D structures from 2D stacks, regardless of how these 2D stacks have been obtained. The algorithm not only reuses the information obtained in the 2D segmentation, but also attempts to correct some typical mistakes made by the 2D segmentation algorithms (for example, under segmentation of tightly-coupled clusters of cells). We have tested our algorithm in a real scenario-the segmentation of the neuronal nuclei in different layers of the rat cerebral cortex. Several representative images from different layers of the cerebral cortex have been considered and several 2D segmentation algorithms have been compared. Furthermore, the algorithm has also been compared with the traditional 3D Watershed algorithm and the results obtained here show better performance in terms of correctly identified neuronal nuclei.

  2. 3D segmentations of neuronal nuclei from confocal microscope image stacks

    PubMed Central

    LaTorre, Antonio; Alonso-Nanclares, Lidia; Muelas, Santiago; Peña, José-María; DeFelipe, Javier

    2013-01-01

    In this paper, we present an algorithm to create 3D segmentations of neuronal cells from stacks of previously segmented 2D images. The idea behind this proposal is to provide a general method to reconstruct 3D structures from 2D stacks, regardless of how these 2D stacks have been obtained. The algorithm not only reuses the information obtained in the 2D segmentation, but also attempts to correct some typical mistakes made by the 2D segmentation algorithms (for example, under segmentation of tightly-coupled clusters of cells). We have tested our algorithm in a real scenario—the segmentation of the neuronal nuclei in different layers of the rat cerebral cortex. Several representative images from different layers of the cerebral cortex have been considered and several 2D segmentation algorithms have been compared. Furthermore, the algorithm has also been compared with the traditional 3D Watershed algorithm and the results obtained here show better performance in terms of correctly identified neuronal nuclei. PMID:24409123

  3. Developing a confocal acoustic holography microscope for non-invasive 3D temperature and composition measurements.

    PubMed

    Herring, Rodney A; Jacquemin, Peter; Sawicka, Barbara D; Atalick, Stefan

    2009-06-01

    A confocal acoustic holography microscope (CAHM) has been designed, simulated and partially verified experimentally to take holograms for non-invasive, three-dimensional measurements of a specimen's refractive indices from one view point. The designed and simulated prototype CAHM used a frequency of 2.25 MHz and measured sound speed changes of 16 m/s, temperature changes of 5 degrees C and had a spatial resolution of 660 microm. With future improvements utilizing the latest technologies such as two-dimensional array detectors, Micro-Electro-Mechanical Systems (MEMS), and acoustic lenses, resolutions of 1m/s, 0.5 degrees C, and 150 microm are expected. The CAHM is expected to have many useful applications, including non-invasive mass and heat transfer measurements in fluids and materials and as a medical diagnostic tool to non-intrusively visualize compositions and temperatures within the human body.

  4. 3D imaging of lung tissue by confocal microscopy and micro-CT

    NASA Astrophysics Data System (ADS)

    Kriete, Andres; Breithecker, Andreas; Rau, Wigbert D.

    2001-07-01

    Two complementary techniques for the imaging of tissue subunits are discussed. A computer guided light microscopic imaging technique is described first, which confocally resolves thick serial sections axially. The lateral area of interest is increased by scanning a mosaic of images in each plane. Subsequently, all images are fused digitally to form a highly resolved volume exhibiting the fine structure of complete respiratory units of lung. A different technique described is based on microtomography. This method allows to image volumes up to 3x3x3 cm at a resolution of up to 7 microns. Due to the lack of strong density differences, a contrast enhancement procedure is introduced which makes this technique applicable for the imaging of lung tissue. Imaging, visualization and analysis described here are parts of an ongoing project to model structure and to simulate function of tissue subunits and complete organs.

  5. Fast 3D visualization of endogenous brain signals with high-sensitivity laser scanning photothermal microscopy

    PubMed Central

    Miyazaki, Jun; Iida, Tadatsune; Tanaka, Shinji; Hayashi-Takagi, Akiko; Kasai, Haruo; Okabe, Shigeo; Kobayashi, Takayoshi

    2016-01-01

    A fast, high-sensitivity photothermal microscope was developed by implementing a spatially segmented balanced detection scheme into a laser scanning microscope. We confirmed a 4.9 times improvement in signal-to-noise ratio in the spatially segmented balanced detection compared with that of conventional detection. The system demonstrated simultaneous bi-modal photothermal and confocal fluorescence imaging of transgenic mouse brain tissue with a pixel dwell time of 20 μs. The fluorescence image visualized neurons expressing yellow fluorescence proteins, while the photothermal signal detected endogenous chromophores in the mouse brain, allowing 3D visualization of the distribution of various features such as blood cells and fine structures probably due to lipids. This imaging modality was constructed using compact and cost-effective laser diodes, and will thus be widely useful in the life and medical sciences. PMID:27231615

  6. Influences of edges and steep slopes in 3D interference and confocal microscopy

    NASA Astrophysics Data System (ADS)

    Xie, Weichang; Hagemeier, Sebastian; Woidt, Carsten; Hillmer, Harmut; Lehmann, Peter

    2016-04-01

    Optical measurement techniques are widely applied in high-resolution contour, topography and roughness measurement. In this context vertical scanning white-light interferometers and confocal microscopes have become mature instruments over the last decades. The accuracy of measurement results is highly related not only to the type and physical properties of the measuring instruments, but also to the measurement object itself. This contribution focuses on measurement effects occurring at edges and height steps using white-light interferometers of different numerical apertures. If the edge is perfectly perpendicular, batwing effects appear at height steps. These batwings show maximum height if the height-to-wavelength-ratio (HWR) is about one forth or three forth, and they disappear if the HWR value is about an integer multiple of one half. The wavelength that is relevant in this context is the effective wavelength, i.e. the center wavelength of the illuminating light multiplied by a correction factor known as the numerical aperture correction. However, in practice the edges are usually not perfectly perpendicular. In this case, the measurement results depend also on the derivative of the surface height function and they may differ from theory and the prediction according to the HWR value. Measurements of such steps show systematical effects depending on the lateral resolution of the instrument. In this context, a Linnik interferometer with a magnification of 100x and NA = 0.9 is used to characterize the three dimensional topography of more or less rectangular calibration specimens and quasi-perpendicular structures produced by the nanoimprint technology. The Linnik interferometer is equipped with LED light sources emitting at different wavelengths, so that the HWR value can be changed. This is possible since the high NA objective lenses show a rather limited depth of focus such that the temporal coherence gating may be replaced by focal gating in this particular

  7. Pavement cracking measurements using 3D laser-scan images

    NASA Astrophysics Data System (ADS)

    Ouyang, W.; Xu, B.

    2013-10-01

    Pavement condition surveying is vital for pavement maintenance programs that ensure ride quality and traffic safety. This paper first introduces an automated pavement inspection system which uses a three-dimensional (3D) camera and a structured laser light to acquire dense transverse profiles of a pavement lane surface when it carries a moving vehicle. After the calibration, the 3D system can yield a depth resolution of 0.5 mm and a transverse resolution of 1.56 mm pixel-1 at 1.4 m camera height from the ground. The scanning rate of the camera can be set to its maximum at 5000 lines s-1, allowing the density of scanned profiles to vary with the vehicle's speed. The paper then illustrates the algorithms that utilize 3D information to detect pavement distress, such as transverse, longitudinal and alligator cracking, and presents the field tests on the system's repeatability when scanning a sample pavement in multiple runs at the same vehicle speed, at different vehicle speeds and under different weather conditions. The results show that this dedicated 3D system can capture accurate pavement images that detail surface distress, and obtain consistent crack measurements in repeated tests and under different driving and lighting conditions.

  8. New methods for the computer-assisted 3-D reconstruction of neurons from confocal image stacks.

    PubMed

    Schmitt, Stephan; Evers, Jan Felix; Duch, Carsten; Scholz, Michael; Obermayer, Klaus

    2004-12-01

    Exact geometrical reconstructions of neuronal architecture are indispensable for the investigation of neuronal function. Neuronal shape is important for the wiring of networks, and dendritic architecture strongly affects neuronal integration and firing properties as demonstrated by modeling approaches. Confocal microscopy allows to scan neurons with submicron resolution. However, it is still a tedious task to reconstruct complex dendritic trees with fine structures just above voxel resolution. We present a framework assisting the reconstruction. User time investment is strongly reduced by automatic methods, which fit a skeleton and a surface to the data, while the user can interact and thus keeps full control to ensure a high quality reconstruction. The reconstruction process composes a successive gain of metric parameters. First, a structural description of the neuron is built, including the topology and the exact dendritic lengths and diameters. We use generalized cylinders with circular cross sections. The user provides a rough initialization by marking the branching points. The axes and radii are fitted to the data by minimizing an energy functional, which is regularized by a smoothness constraint. The investigation of proximity to other structures throughout dendritic trees requires a precise surface reconstruction. In order to achieve accuracy of 0.1 microm and below, we additionally implemented a segmentation algorithm based on geodesic active contours that allow for arbitrary cross sections and uses locally adapted thresholds. In summary, this new reconstruction tool saves time and increases quality as compared to other methods, which have previously been applied to real neurons.

  9. 3D Laser Triangulation for Plant Phenotyping in Challenging Environments

    PubMed Central

    Kjaer, Katrine Heinsvig; Ottosen, Carl-Otto

    2015-01-01

    To increase the understanding of how the plant phenotype is formed by genotype and environmental interactions, simple and robust high-throughput plant phenotyping methods should be developed and considered. This would not only broaden the application range of phenotyping in the plant research community, but also increase the ability for researchers to study plants in their natural environments. By studying plants in their natural environment in high temporal resolution, more knowledge on how multiple stresses interact in defining the plant phenotype could lead to a better understanding of the interaction between plant responses and epigenetic regulation. In the present paper, we evaluate a commercial 3D NIR-laser scanner (PlantEye, Phenospex B.V., Herleen, The Netherlands) to track daily changes in plant growth with high precision in challenging environments. Firstly, we demonstrate that the NIR laser beam of the scanner does not affect plant photosynthetic performance. Secondly, we demonstrate that it is possible to estimate phenotypic variation amongst the growth pattern of ten genotypes of Brassica napus L. (rapeseed), using a simple linear correlation between scanned parameters and destructive growth measurements. Our results demonstrate the high potential of 3D laser triangulation for simple measurements of phenotypic variation in challenging environments and in a high temporal resolution. PMID:26066990

  10. 3D Laser Triangulation for Plant Phenotyping in Challenging Environments.

    PubMed

    Kjaer, Katrine Heinsvig; Ottosen, Carl-Otto

    2015-06-09

    To increase the understanding of how the plant phenotype is formed by genotype and environmental interactions, simple and robust high-throughput plant phenotyping methods should be developed and considered. This would not only broaden the application range of phenotyping in the plant research community, but also increase the ability for researchers to study plants in their natural environments. By studying plants in their natural environment in high temporal resolution, more knowledge on how multiple stresses interact in defining the plant phenotype could lead to a better understanding of the interaction between plant responses and epigenetic regulation. In the present paper, we evaluate a commercial 3D NIR-laser scanner (PlantEye, Phenospex B.V., Herleen, The Netherlands) to track daily changes in plant growth with high precision in challenging environments. Firstly, we demonstrate that the NIR laser beam of the scanner does not affect plant photosynthetic performance. Secondly, we demonstrate that it is possible to estimate phenotypic variation amongst the growth pattern of ten genotypes of Brassica napus L. (rapeseed), using a simple linear correlation between scanned parameters and destructive growth measurements. Our results demonstrate the high potential of 3D laser triangulation for simple measurements of phenotypic variation in challenging environments and in a high temporal resolution.

  11. Ellipsoid Segmentation Model for Analyzing Light-Attenuated 3D Confocal Image Stacks of Fluorescent Multi-Cellular Spheroids

    PubMed Central

    Barbier, Michaël; Jaensch, Steffen; Cornelissen, Frans; Vidic, Suzana; Gjerde, Kjersti; de Hoogt, Ronald; Graeser, Ralph; Gustin, Emmanuel; Chong, Yolanda T.

    2016-01-01

    In oncology, two-dimensional in-vitro culture models are the standard test beds for the discovery and development of cancer treatments, but in the last decades, evidence emerged that such models have low predictive value for clinical efficacy. Therefore they are increasingly complemented by more physiologically relevant 3D models, such as spheroid micro-tumor cultures. If suitable fluorescent labels are applied, confocal 3D image stacks can characterize the structure of such volumetric cultures and, for example, cell proliferation. However, several issues hamper accurate analysis. In particular, signal attenuation within the tissue of the spheroids prevents the acquisition of a complete image for spheroids over 100 micrometers in diameter. And quantitative analysis of large 3D image data sets is challenging, creating a need for methods which can be applied to large-scale experiments and account for impeding factors. We present a robust, computationally inexpensive 2.5D method for the segmentation of spheroid cultures and for counting proliferating cells within them. The spheroids are assumed to be approximately ellipsoid in shape. They are identified from information present in the Maximum Intensity Projection (MIP) and the corresponding height view, also known as Z-buffer. It alerts the user when potential bias-introducing factors cannot be compensated for and includes a compensation for signal attenuation. PMID:27303813

  12. MDL constrained 3-D grayscale skeletonization algorithm for automated extraction of dendrites and spines from fluorescence confocal images.

    PubMed

    Yuan, Xiaosong; Trachtenberg, Joshua T; Potter, Steve M; Roysam, Badrinath

    2009-12-01

    This paper presents a method for improved automatic delineation of dendrites and spines from three-dimensional (3-D) images of neurons acquired by confocal or multi-photon fluorescence microscopy. The core advance presented here is a direct grayscale skeletonization algorithm that is constrained by a structural complexity penalty using the minimum description length (MDL) principle, and additional neuroanatomy-specific constraints. The 3-D skeleton is extracted directly from the grayscale image data, avoiding errors introduced by image binarization. The MDL method achieves a practical tradeoff between the complexity of the skeleton and its coverage of the fluorescence signal. Additional advances include the use of 3-D spline smoothing of dendrites to improve spine detection, and graph-theoretic algorithms to explore and extract the dendritic structure from the grayscale skeleton using an intensity-weighted minimum spanning tree (IW-MST) algorithm. This algorithm was evaluated on 30 datasets organized in 8 groups from multiple laboratories. Spines were detected with false negative rates less than 10% on most datasets (the average is 7.1%), and the average false positive rate was 11.8%. The software is available in open source form.

  13. Confocal (micro)-XRF for 3D anlaysis of elements distribution in hot environmental particles

    SciTech Connect

    Bielewski, M; Eriksson, M; Himbert, J; Simon, R; Betti, M; Hamilton, T F

    2007-11-27

    Studies on the fate and transport of radioactive contaminates in the environment are often constrained by a lack of knowledge on the elemental distribution and general behavior of particulate bound radionuclides contained in hot particles. A number of hot particles were previously isolated from soil samples collected at former U.S. nuclear test sites in the Marshall Islands and characterized using non-destructive techniques [1]. The present investigation at HASYLAB is a part of larger research program at ITU regarding the characterization of environmental radioactive particles different locations and source-terms. Radioactive particles in the environment are formed under a number of different release scenarios and, as such, their physicochemical properties may provide a basis for identifying source-term specific contamination regimes. Consequently, studies on hot particles are not only important in terms of studying the elemental composition and geochemical behavior of hot particles but may also lead to advances in assessing the long-term impacts of radioactive contamination on the environment. Six particles isolated from soil samples collected at the Marshall Islands were studied. The element distribution in the particles was determined by confocal {micro}-XRF analysis using the ANKA FLUO beam line. The CRL (compound refractive lens) was used to focus the exciting beam and the polycapillary half lens to collimate the detector. The dimensions of confocal spot were measured by 'knife edge scanning' method with thin gold structure placed at Si wafer. The values of 3.1 x 1.4 x 18.4 {micro}m were achieved if defined as FWHMs of measured L?intensity profiles and when the19.1 keV exciting radiation was used. The collected XRF spectra were analyzed offline with AXIL [2] software to obtain net intensities of element characteristic lines.Further data processing and reconstruction of element distribution was done with the software 'R' [3] dedicated for statistical

  14. Laser embedding electronics on 3D printed objects

    NASA Astrophysics Data System (ADS)

    Kirleis, Matthew A.; Simonson, Duane; Charipar, Nicholas A.; Kim, Heungsoo; Charipar, Kristin M.; Auyeung, Ray C. Y.; Mathews, Scott A.; Piqué, Alberto

    2014-03-01

    Additive manufacturing techniques such as 3D printing are able to generate reproductions of a part in free space without the use of molds; however, the objects produced lack electrical functionality from an applications perspective. At the same time, techniques such as inkjet and laser direct-write (LDW) can be used to print electronic components and connections onto already existing objects, but are not capable of generating a full object on their own. The approach missing to date is the combination of 3D printing processes with direct-write of electronic circuits. Among the numerous direct write techniques available, LDW offers unique advantages and capabilities given its compatibility with a wide range of materials, surface chemistries and surface morphologies. The Naval Research Laboratory (NRL) has developed various LDW processes ranging from the non-phase transformative direct printing of complex suspensions or inks to lase-and-place for embedding entire semiconductor devices. These processes have been demonstrated in digital manufacturing of a wide variety of microelectronic elements ranging from circuit components such as electrical interconnects and passives to antennas, sensors, actuators and power sources. At NRL we are investigating the combination of LDW with 3D printing to demonstrate the digital fabrication of functional parts, such as 3D circuits. Merging these techniques will make possible the development of a new generation of structures capable of detecting, processing, communicating and interacting with their surroundings in ways never imagined before. This paper shows the latest results achieved at NRL in this area, describing the various approaches developed for generating 3D printed electronics with LDW.

  15. 3D laser optoacoustic ultrasonic imaging system for preclinical research

    NASA Astrophysics Data System (ADS)

    Ermilov, Sergey A.; Conjusteau, André; Hernandez, Travis; Su, Richard; Nadvoretskiy, Vyacheslav; Tsyboulski, Dmitri; Anis, Fatima; Anastasio, Mark A.; Oraevsky, Alexander A.

    2013-03-01

    In this work, we introduce a novel three-dimensional imaging system for in vivo high-resolution anatomical and functional whole-body visualization of small animal models developed for preclinical or other type of biomedical research. The system (LOUIS-3DM) combines a multi-wavelength optoacoustic and ultrawide-band laser ultrasound tomographies to obtain coregistered maps of tissue optical absorption and acoustic properties, displayed within the skin outline of the studied animal. The most promising applications of the LOUIS-3DM include 3D angiography, cancer research, and longitudinal studies of biological distribution of optoacoustic contrast agents (carbon nanotubes, metal plasmonic nanoparticles, etc.).

  16. Automating laser scanning of 3D surfaces for reverse engineering

    NASA Astrophysics Data System (ADS)

    Chan, Vincent H.; Bradley, Colin H.; Vickers, Geoffrey W.

    1997-12-01

    Application of current 3-D laser scanning systems to reverse engineering is limited by two obstacles. The meticulous guidance of the laser scanner over the surface of the object being scanned and the segmentation of the cloud data which is collected by the laser scanner. Presently, both obstacles are being manually solved. The guidance of the laser scanning sensor at the correct surface to sensor distance is dependent on operator judgement and the segmentation of the collected data is reliant on the user to manually define surface boundaries on a computer screen. By applying a 2-D CCD camera, both of these problems can be resolved. Depth information on the location of the object surface can be derived from a pair of stereo images from the CCD camera. Using this depth information, the scanner path can be automatically calculated. Segmentation of the object surface can be accomplished by employing a Kohonen neural network into the CCD image. Successful segmentation of the image is conditional on the locations selected to start neural nodes as well as the prevention of the neuron connectors from bleeding onto neighboring patches. Thus the CCD camera allows for the automatic path planning of the laser scanner as well as the segmentation of the surface into patches defined along its natural boundaries.

  17. 3D image reconstruction using optical sectioning in confocal scanning microscopy

    NASA Astrophysics Data System (ADS)

    Seo, Jungwoo; Kang, Dong Kyun; Park, Sunglim; Gweon, Dae gab

    2001-10-01

    Confocal scanning microscopy (CSM) has been used in biological application, materials science, semiconductor quality measurement and other non-destructive microscopic application. Small spot of light illuminates a sample, and a small detector that is ideally a point detector collects the reflected or transmitted light having the information of specimen. An image distribution can be reconstructed by a correlation analysis of spots with the high bandwidth. The mechanism for two-dimensional beam scanning and optical sectioning has an important role in CSM as the three-dimensional profiler. The parasitic motion of focus on the detector gives rise to the fatal distortion of an image profile named the extinction effect while using acousto-optical (AO) deflector. The intensity profile for the open loop scanning should be matched with its response for the standard. The non-linearity can be minimized with the optical sectioning or the optical probe of the closed loop control. This paper shows the mathematical expression of the light such as the extinction curve in the optical fields of system using AO deflector, the axial/lateral response experimentally when the error sources change, and the methods of optical sectioning. We propose the progressive methods for the high quality image as the following. At first, for having the corrected image, small spot and long scan range, this paper shows that the optimal design having the multi-objects can be used by choosing the unitary lens device in CSM. At second, in order to compensate for the intensity cancellation at the end profile that may be the cause of waviness for the optical image, this paper shows that it is efficient to schedule the frequency of scan. According to characteristics of the extinction curve and axial/lateral response having the error property, we can define the frequency and sensitivity of as their robustness. Finally, the axial response gives an important motive for the optical section, and the limit of

  18. High-contrast step-index waveguides in borate nonlinear laser crystals by 3D laser writing.

    PubMed

    Rodenas, Airan; Kar, Ajoy K

    2011-08-29

    We report the ultrafast fabrication of high-contrast step-index channel waveguides in Nd(3+):YCa(4)O(BO(3))(3) borate laser crystals by means of 3D direct laser writing. Guiding up to 3.4 μm wavelength is demonstrated for the first time in a laser written crystalline waveguide. Modeling the measured fundamental modes at the wavelengths of 1.9 µm and 3.4 µm allowed us to estimate the high laser-induced refractive index increments (index contrasts) to be 0.010 (0.59%), and 0.005 (0.29%), respectively. Confocal µ-Raman spectral imaging of the waveguides cross-sections confirmed that the cores have very well defined step profiles, and that the increase in the refractive index can be linked to the localized creation of permanent intrinsic defects. These results indicate that this crystalline waveguides are a potential candidate for the development of 3D active waveguide circuits, due to the laser and electro-optic properties of rare earth doped borate crystals.

  19. Laboratory-based characterization of plutonium in soil particles using micro-XRF and 3D confocal XRF

    SciTech Connect

    McIntosh, Kathryn Gallagher; Cordes, Nikolaus Lynn; Patterson, Brian M.; Havrilla, George Joseph

    2015-03-29

    The investigation of plutonium (Pu) in a soil matrix is of interest in safeguards, nuclear forensics, and environmental remediation activities. The elemental composition of two plutonium contaminated soil particles was characterized nondestructively using a pair of micro X-ray fluorescence spectrometry (micro-XRF) techniques including high resolution X-ray (hiRX) and 3D confocal XRF. The three dimensional elemental imaging capability of confocal XRF permitted the identification two distinct Pu particles within the samples: one external to the Ferich soil matrix and another co-located with Cu within the soil matrix. The size and morphology of the particles was assessed with X-ray transmission microscopy and micro X-ray computed tomography (micro-CT) providing complementary morphological information. Limits of detection for a 30 μm Pu particle are <10 ng for each of the XRF techniques. Ultimately, this study highlights the capability for lab-based, nondestructive, spatially resolved characterization of heterogeneous matrices on the micrometer scale with nanogram sensitivity.

  20. Laboratory-based characterization of plutonium in soil particles using micro-XRF and 3D confocal XRF

    DOE PAGES

    McIntosh, Kathryn Gallagher; Cordes, Nikolaus Lynn; Patterson, Brian M.; ...

    2015-03-29

    The investigation of plutonium (Pu) in a soil matrix is of interest in safeguards, nuclear forensics, and environmental remediation activities. The elemental composition of two plutonium contaminated soil particles was characterized nondestructively using a pair of micro X-ray fluorescence spectrometry (micro-XRF) techniques including high resolution X-ray (hiRX) and 3D confocal XRF. The three dimensional elemental imaging capability of confocal XRF permitted the identification two distinct Pu particles within the samples: one external to the Ferich soil matrix and another co-located with Cu within the soil matrix. The size and morphology of the particles was assessed with X-ray transmission microscopy andmore » micro X-ray computed tomography (micro-CT) providing complementary morphological information. Limits of detection for a 30 μm Pu particle are <10 ng for each of the XRF techniques. Ultimately, this study highlights the capability for lab-based, nondestructive, spatially resolved characterization of heterogeneous matrices on the micrometer scale with nanogram sensitivity.« less

  1. Design of a compact 3D laser scanner

    NASA Astrophysics Data System (ADS)

    Geusen, Mark, Jr.; van Amstel, Willem D.; Baumer, Stefan M. B.; Horijon, Jef L.

    1999-08-01

    A design study for a compact 3D scanner, called Coplan, is presented. The Coplan is intended to be used for high speed, in-line coplanarity and shape measurement of electronic components, like Ball Grid Arrays and Surface Mount Devices. The scanner should have a scan length of at least 2 inches and a resolution of 5 micrometers in all 3 dimensions. First an analysis of two different scan schemes is made: a so-called pre-objective scheme using an F-(theta) scan lens and a post- objective scheme using a so-called banana field flattener, consisting of a convex, cylindrical hyperbolic mirror and a concave, cylindrical parabolic mirror. Secondly, an analysis of height resolution requirements for triangulation and confocal depth sensing has been made. It is concluded that for both methods of depth sensing a synchronous scheme with a 50-60 degrees detection angle in cross scan direction is required. It is shown that a post-objective scheme consisting of a banana mirror system combined with triangulation height detection offers the best solution for the optical requirements.

  2. FOOD SURFACE TEXTURE MEASUREMENT USING REFLECTIVE CONFOCAL LASER SCANNING MICROSCOPY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Confocal laser scanning microscopy (CLSM) was used in the reflection mode to characterize the surface texture (roughness) of sliced food surfaces. Sandpapers of grit size between 150 and 600 were used as the height reference to standardize the CLSM hardware settings. Sandpaper particle sizes were v...

  3. An omnidirectional 3D sensor with line laser scanning

    NASA Astrophysics Data System (ADS)

    Xu, Jing; Gao, Bingtuan; Liu, Chuande; Wang, Peng; Gao, Shuanglei

    2016-09-01

    An active omnidirectional vision owns the advantages of the wide field of view (FOV) imaging, resulting in an entire 3D environment scene, which is promising in the field of robot navigation. However, the existing omnidirectional vision sensors based on line laser can measure points only located on the optical plane of the line laser beam, resulting in the low-resolution reconstruction. Whereas, to improve resolution, some other omnidirectional vision sensors with the capability of projecting 2D encode pattern from projector and curved mirror. However, the astigmatism property of curve mirror causes the low-accuracy reconstruction. To solve the above problems, a rotating polygon scanning mirror is used to scan the object in the vertical direction so that an entire profile of the observed scene can be obtained at high accuracy, without of astigmatism phenomenon. Then, the proposed method is calibrated by a conventional 2D checkerboard plate. The experimental results show that the measurement error of the 3D omnidirectional sensor is approximately 1 mm. Moreover, the reconstruction of objects with different shapes based on the developed sensor is also verified.

  4. Three-dimensional scanning confocal laser microscope

    DOEpatents

    Anderson, R. Rox; Webb, Robert H.; Rajadhyaksha, Milind

    1999-01-01

    A confocal microscope for generating an image of a sample includes a first scanning element for scanning a light beam along a first axis, and a second scanning element for scanning the light beam at a predetermined amplitude along a second axis perpendicular to the first axis. A third scanning element scans the light beam at a predetermined amplitude along a third axis perpendicular to an imaging plane defined by the first and second axes. The second and third scanning element are synchronized to scan at the same frequency. The second and third predetermined amplitudes are percentages of their maximum amplitudes. A selector determines the second and third predetermined amplitudes such that the sum of the percentages is equal to one-hundred percent.

  5. Automatic Detection, Segmentation and Classification of Retinal Horizontal Neurons in Large-scale 3D Confocal Imagery

    SciTech Connect

    Karakaya, Mahmut; Kerekes, Ryan A; Gleason, Shaun Scott; Martins, Rodrigo; Dyer, Michael

    2011-01-01

    Automatic analysis of neuronal structure from wide-field-of-view 3D image stacks of retinal neurons is essential for statistically characterizing neuronal abnormalities that may be causally related to neural malfunctions or may be early indicators for a variety of neuropathies. In this paper, we study classification of neuron fields in large-scale 3D confocal image stacks, a challenging neurobiological problem because of the low spatial resolution imagery and presence of intertwined dendrites from different neurons. We present a fully automated, four-step processing approach for neuron classification with respect to the morphological structure of their dendrites. In our approach, we first localize each individual soma in the image by using morphological operators and active contours. By using each soma position as a seed point, we automatically determine an appropriate threshold to segment dendrites of each neuron. We then use skeletonization and network analysis to generate the morphological structures of segmented dendrites, and shape-based features are extracted from network representations of each neuron to characterize the neuron. Based on qualitative results and quantitative comparisons, we show that we are able to automatically compute relevant features that clearly distinguish between normal and abnormal cases for postnatal day 6 (P6) horizontal neurons.

  6. Ultrafast laser inscription of 3D components for spatial multiplexing

    NASA Astrophysics Data System (ADS)

    Thomson, Robert R.

    2016-02-01

    The thirst for bandwidth in telecommunications networks is becoming ever larger due to bandwidth hungry applications such as video-on-demand. To further increase the bandwidth capacity, engineers are now seeking to imprint information on the last remaining degree of freedom of the lightwave carrier - space. This has given rise to the field of Space Division Multiplexing (SDM). In essence, the concept of SDM simple; we aim to use the different spatial modes of an optical fibre as multiplexed data transmission channels. These modes could either be in the form of separate singlemodes in a multicore optical fibre, individual spatial modes of a multimode fibre, or indeed the individual spatial modes of a multimode multicore optical fibre. Regardless of the particular "flavour" of SDM in question, it is clear that significant interfacing issues exist between the optical fibres used in SDM and the conventional single-mode planar lightwave circuits that are essential to process the light (e.g. arrayed waveguide gratings and splitters), and efficient interconnect technologies will be required. One fabrication technology that has emerged as a possible route to solve these interconnection issues is ultrafast laser inscription (ULI), which relies on the use of focused ultrashort laser pulses to directly inscribe three-dimensional waveguide structures inside a bulk dielectric. In this paper, I describe some of the work that has been conducted around the world to apply the unique waveguide fabrication capabilities of ULI to the development of 3D photonic components for applications in SDM.

  7. Confocal scanning laser ophthalmoscopy in glaucoma diagnosis and management.

    PubMed

    Alexandrescu, C; Dascalu, A M; Panca, A; Sescioreanu, A; Mitulescu, C; Ciuluvica, R; Voinea, L; Celea, C

    2010-01-01

    The early diagnosis and detection of progression are two key-elements in the actual management of glaucoma. The current opinion in clinical practice is to quantify the structural damage for a better follow-up of the patient and the standardization of the results. The present review is a concise survey of literature covering the period of 1990-2010, documenting the evidence-based role of confocal scanning laser ophthalmoscopy in glaucoma diagnosis and management.

  8. Compact confocal readout system for three-dimensional memories using a laser-feedback semiconductor laser.

    PubMed

    Nakano, Masaharu; Kawata, Yoshimasa

    2003-08-01

    We present a compact confocal readout system for three-dimensional optical memories that uses the thresholding property of a semiconductor laser for feedback light. The system has higher axial resolution than a conventional confocal system with a pinhole. We demonstrate readout results for data recorded in two recording layers with the developed system.

  9. A method for simultaneously delineating multiple targets in 3D-FISH using limited channels, lasers, and fluorochromes.

    PubMed

    Zhao, F Y; Yang, X; Chen, D Y; Ma, W Y; Zheng, J G; Zhang, X M

    2014-01-01

    Many studies have suggested a link between the spatial organization of genomes and fundamental biological processes such as genome reprogramming, gene expression, and differentiation. Multicolor fluorescence in situ hybridization on three-dimensionally preserved nuclei (3D-FISH), in combination with confocal microscopy, has become an effective technique for analyzing 3D genome structure and spatial patterns of defined nucleus targets including entire chromosome territories and single gene loci. This technique usually requires the simultaneous visualization of numerous targets labeled with different colored fluorochromes. Thus, the number of channels and lasers must be sufficient for the commonly used labeling scheme of 3D-FISH, "one probe-one target". However, these channels and lasers are usually restricted by a given microscope system. This paper presents a method for simultaneously delineating multiple targets in 3D-FISH using limited channels, lasers, and fluorochromes. In contrast to other labeling schemes, this method is convenient and simple for multicolor 3D-FISH studies, which may result in widespread adoption of the technique. Lastly, as an application of the method, the nucleus locations of chromosome territory 18/21 and centromere 18/21/13 in normal human lymphocytes were analyzed, which might present evidence of a radial higher order chromatin arrangement.

  10. Imaging System With Confocally Self-Detecting Laser.

    DOEpatents

    Webb, Robert H.; Rogomentich, Fran J.

    1996-10-08

    The invention relates to a confocal laser imaging system and method. The system includes a laser source, a beam splitter, focusing elements, and a photosensitive detector. The laser source projects a laser beam along a first optical path at an object to be imaged, and modulates the intensity of the projected laser beam in response to light reflected from the object. A beam splitter directs a portion of the projected laser beam onto a photodetector. The photodetector monitors the intensity of laser output. The laser source can be an electrically scannable array, with a lens or objective assembly for focusing light generated by the array onto the object of interest. As the array is energized, its laser beams scan over the object, and light reflected at each point is returned by the lens to the element of the array from which it originated. A single photosensitive detector element can generate an intensity-representative signal for all lasers of the array. The intensity-representative signal from the photosensitive detector can be processed to provide an image of the object of interest.

  11. The design and construction of a cost-efficient confocal laser scanning microscope

    NASA Astrophysics Data System (ADS)

    Xi, Peng; Rajwa, Bartlomiej; Jones, James T.; Robinson, J. Paul

    2007-03-01

    The optical dissection ability of confocal microscopy makes it a powerful tool for biological materials. However, the cost and complexity of confocal scanning laser microscopy hinders its wide application in education. We describe the construction of a simplified confocal scanning laser microscope and demonstrate three-dimensional projection based on cost-efficient commercial hardware, together with available open source software.

  12. 3D reconstruction and characterization of laser induced craters by in situ optical microscopy

    NASA Astrophysics Data System (ADS)

    Casal, A.; Cerrato, R.; Mateo, M. P.; Nicolas, G.

    2016-06-01

    A low-cost optical microscope was developed and coupled to an irradiation system in order to study the induced effects on material during a multipulse regime by an in situ visual inspection of the surface, in particular of the spot generated at different pulses. In the case of laser ablation, a reconstruction of the crater in 3D was made from the images of the sample surface taken during the irradiation process, and the subsequent profiles of ablated material were extracted. The implementation of this homemade optical device gives an added value to the irradiation system, providing information about morphology evolution of irradiated area when successive pulses are applied. In particular, the determination of ablation rates in real time can be especially useful for a better understanding and controlling of the ablation process in applications where removal of material is involved, such as laser cleaning and in-depth characterization of multilayered samples and diffusion processes. The validation of the developed microscope was made by a comparison with a commercial confocal microscope configured for the characterization of materials where similar results of crater depth and diameter were obtained for both systems.

  13. Mobile 3D laser scanning technology application in the surveying of urban underground rail transit

    NASA Astrophysics Data System (ADS)

    Han, Youmei; Yang, Bogang; Zhen, Yinan

    2016-11-01

    Mobile 3D laser scanning technology is one hot kind of digital earth technology. 3D completion surveying is relative new concept in surveying and mapping. A kind of mobile 3D laser scanning system was developed for the urban underground rail 3D completion surveying. According to the characteristics of underground rail environment and the characters of the mobile laser scanning system, it designed a suitable test scheme to improving the accuracy of this kind of mobile laser scanning system when it worked under no GPS signal environment. Then it completed the application of this technology in the No.15 rail 3D completion surveying. Meanwhile a set of production process was made for the 3D completion surveying based on this kind of mobile 3D laser scanning technology. These products were also proved the efficiency of the new technology in the rail 3D completion surveying. Using mobile 3D laser scanning technology to complete underground rail completion surveying has been the first time in China until now. It can provide a reference for 3D measurement of rail completion surveying or the 3D completion surveying of other areas.

  14. [Application of confocal laser scanning microscope in forensic pathology].

    PubMed

    Zhuo, Luo; Hu, Le-Sheng; Zhou, Lan; Zheng, Na; Liang, Man; Yang, Fan; Liu, Liang

    2009-12-01

    Confocal laser scanning microscopy(CLSM) is a new technique for microscopic imaging, which can collect the transverse section image of the samples and produce three-dimensional reconstruction and present higher spatial resolution than the conventional light microscope. As a precision instrument for the microscopic image, it plays an important role in forensic pathology. The article reviews the recent research achievements from sudden cardiac death, bullet wound and nervous system damage, etc, and explores the potential applications of the forensic pathology research and forensic practice.

  15. Femtosecond laser fabricated electrofluidic devices in glass for 3D manipulation of biological samples

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Midorikawa, Katsumi; Sugioka, Koji

    2016-03-01

    Novel electrofluidic microdevices based on monolithic integration of 3D metal electrodes into 3D glass microchannels have been prepared by femtosecond (fs) laser hybrid microfabrication. 3D microchannels with smooth internal walls are first prepared in photosensitive glass by fs laser-assisted chemical wet etching process combined with post-annealing. Then, 3D electrode patterning in prepared glass channels is carried out by water-assisted fs-laser direct-write ablation using the same laser followed by electroless metal plating. Laser processing parameters are optimized and the roles of water during the laser irradiation are discussed. The fabricated electrofluidic devices are applied to demonstrate 3D electro-orientation of cells in microfluidic environments.

  16. Probe based confocal laser endomicroscopy of the pancreatobiliary system

    PubMed Central

    Almadi, Majid A; Neumann, Helmut

    2015-01-01

    AIM: To review applications of confocal laser endomicroscopy (CLE) in pancreatobiliary lesions and studies that assessed training and interpretation of images. METHODS: A computerized literature search was performed using OVID MEDLINE, EMBASE, Cochrane library, and the ISI Web of Knowledge from 1980 to October 2014. We also searched abstracts from major meetings that included the Digestive Disease Week, Canadian Digestive Disease Week and the United European Gastroenterology Week using a combination of controlled vocabulary and text words related to pCLE, confocal, endomicroscopy, probe-based confocal laser endomicroscopy, and bile duct to identify reports of trials. In addition, recursive searches and cross-referencing was performed, and manual searches of articles identified after the initial search was also completed. We included fully published articles and those in abstract form. Given the relatively recent introduction of CLE we included randomized trials and cohort studies. RESULTS: In the evaluation of indeterminate pancreatobiliary strictures CLE with ERCP compared to ERCP alone can increase the detection of cancerous strictures with a sensitivity of (98% vs 45%) and has a negative predictive value (97% vs 69%), but decreased the specificity (67% vs 100%) and the positive predictive value (71% vs 100%) when compared to index pathology. Modifications in the classification systems in indeterminate biliary strictures have increased the specificity of pCLE from 67% to 73%. In pancreatic cystic lesions there is a need to develop similar systems to interpret and characterize lesions based on CLE images obtained. The presence of superficial vascular network predicts serous cystadenomas accurately. Also training in acquiring and interpretation of images is feasible in those without any prior knowledge in CLE in a relatively simple manner and computer-aided diagnosis software is a promising innovation. CONCLUSION: The role of pCLE in the evaluation of

  17. Error analysis for a laser differential confocal radius measurement system.

    PubMed

    Wang, Xu; Qiu, Lirong; Zhao, Weiqian; Xiao, Yang; Wang, Zhongyu

    2015-02-10

    In order to further improve the measurement accuracy of the laser differential confocal radius measurement system (DCRMS) developed previously, a DCRMS error compensation model is established for the error sources, including laser source offset, test sphere position adjustment offset, test sphere figure, and motion error, based on analyzing the influences of these errors on the measurement accuracy of radius of curvature. Theoretical analyses and experiments indicate that the expanded uncertainty of the DCRMS is reduced to U=0.13  μm+0.9  ppm·R (k=2) through the error compensation model. The error analysis and compensation model established in this study can provide the theoretical foundation for improving the measurement accuracy of the DCRMS.

  18. Laser confocal microscope with wavelet-profiled point spread function

    NASA Astrophysics Data System (ADS)

    Romero, Mary Jacquiline; Bautista, Godofredo; Daria, Vincent Ricardo; Saloma, Caesar

    2010-04-01

    We report a laser-scanning confocal reflectance microscope with a wavelet-profiled point spread function (PSF) for rapid multi-resolution extraction and analysis of microscopic object features. The PSF is generated via holography by encoding a π-phase shifting disk unto a collimated laser beam via a phase-only spatial light modulator (SLM) that is positioned at the pupil plane of the focusing objective lens. Scaling of the transverse PSF distribution is achieved by selecting a suitable ratio of the π-phase shifting disk radius and the pupil aperture radius. With one and the same objective lens and one SLM to control the phase profile of the pupil function, we produce amplitude PSF distributions that are accurate scaled representations of the circularly-symmetric Mexican hat mother wavelet.

  19. Characterization of hydrogel microstructure using laser tweezers particle tracking and confocal reflection imaging

    NASA Astrophysics Data System (ADS)

    Kotlarchyk, M. A.; Botvinick, E. L.; Putnam, A. J.

    2010-05-01

    Hydrogels are commonly used as extracellular matrix mimetics for applications in tissue engineering and increasingly as cell culture platforms with which to study the influence of biophysical and biochemical cues on cell function in 3D. In recent years, a significant number of studies have focused on linking substrate mechanical properties to cell function using standard methodologies to characterize the bulk mechanical properties of the hydrogel substrates. However, current understanding of the correlations between the microstructural mechanical properties of hydrogels and cell function in 3D is poor, in part because of a lack of appropriate techniques. Here we have utilized a laser tracking system, based on passive optical microrheology instrumentation, to characterize the microstructure of viscoelastic fibrin clots. Trajectories and mean square displacements were observed as bioinert PEGylated (PEG: polyethylene glycol) microspheres (1, 2 or 4.7 µm in diameter) diffused within confined pores created by the protein phase of fibrin hydrogels. Complementary confocal reflection imaging revealed microstructures comprised of a highly heterogeneous fibrin network with a wide range of pore sizes. As the protein concentration of fibrin gels was increased, our quantitative laser tracking measurements showed a corresponding decrease in particle mean square displacements with greater resolution and sensitivity than conventional imaging techniques. This platform-independent method will enable a more complete understanding of how changes in substrate mechanical properties simultaneously influence other microenvironmental parameters in 3D cultures.

  20. Characterization of hydrogel microstructure using laser tweezers particle tracking and confocal reflection imaging.

    PubMed

    Kotlarchyk, M A; Botvinick, E L; Putnam, A J

    2010-05-19

    Hydrogels are commonly used as extracellular matrix mimetics for applications in tissue engineering and increasingly as cell culture platforms with which to study the influence of biophysical and biochemical cues on cell function in 3D. In recent years, a significant number of studies have focused on linking substrate mechanical properties to cell function using standard methodologies to characterize the bulk mechanical properties of the hydrogel substrates. However, current understanding of the correlations between the microstructural mechanical properties of hydrogels and cell function in 3D is poor, in part because of a lack of appropriate techniques. Here we have utilized a laser tracking system, based on passive optical microrheology instrumentation, to characterize the microstructure of viscoelastic fibrin clots. Trajectories and mean square displacements were observed as bioinert PEGylated (PEG: polyethylene glycol) microspheres (1, 2 or 4.7 μm in diameter) diffused within confined pores created by the protein phase of fibrin hydrogels. Complementary confocal reflection imaging revealed microstructures comprised of a highly heterogeneous fibrin network with a wide range of pore sizes. As the protein concentration of fibrin gels was increased, our quantitative laser tracking measurements showed a corresponding decrease in particle mean square displacements with greater resolution and sensitivity than conventional imaging techniques. This platform-independent method will enable a more complete understanding of how changes in substrate mechanical properties simultaneously influence other microenvironmental parameters in 3D cultures.

  1. Bore-Sight Calibration of Multiple Laser Range Finders for Kinematic 3D Laser Scanning Systems.

    PubMed

    Jung, Jaehoon; Kim, Jeonghyun; Yoon, Sanghyun; Kim, Sangmin; Cho, Hyoungsig; Kim, Changjae; Heo, Joon

    2015-05-04

    The Simultaneous Localization and Mapping (SLAM) technique has been used for autonomous navigation of mobile systems; now, its applications have been extended to 3D data acquisition of indoor environments. In order to reconstruct 3D scenes of indoor space, the kinematic 3D laser scanning system, developed herein, carries three laser range finders (LRFs): one is mounted horizontally for system-position correction and the other two are mounted vertically to collect 3D point-cloud data of the surrounding environment along the system's trajectory. However, the kinematic laser scanning results can be impaired by errors resulting from sensor misalignment. In the present study, the bore-sight calibration of multiple LRF sensors was performed using a specially designed double-deck calibration facility, which is composed of two half-circle-shaped aluminum frames. Moreover, in order to automatically achieve point-to-point correspondences between a scan point and the target center, a V-shaped target was designed as well. The bore-sight calibration parameters were estimated by a constrained least squares method, which iteratively minimizes the weighted sum of squares of residuals while constraining some highly-correlated parameters. The calibration performance was analyzed by means of a correlation matrix. After calibration, the visual inspection of mapped data and residual calculation confirmed the effectiveness of the proposed calibration approach.

  2. Bore-Sight Calibration of Multiple Laser Range Finders for Kinematic 3D Laser Scanning Systems

    PubMed Central

    Jung, Jaehoon; Kim, Jeonghyun; Yoon, Sanghyun; Kim, Sangmin; Cho, Hyoungsig; Kim, Changjae; Heo, Joon

    2015-01-01

    The Simultaneous Localization and Mapping (SLAM) technique has been used for autonomous navigation of mobile systems; now, its applications have been extended to 3D data acquisition of indoor environments. In order to reconstruct 3D scenes of indoor space, the kinematic 3D laser scanning system, developed herein, carries three laser range finders (LRFs): one is mounted horizontally for system-position correction and the other two are mounted vertically to collect 3D point-cloud data of the surrounding environment along the system’s trajectory. However, the kinematic laser scanning results can be impaired by errors resulting from sensor misalignment. In the present study, the bore-sight calibration of multiple LRF sensors was performed using a specially designed double-deck calibration facility, which is composed of two half-circle-shaped aluminum frames. Moreover, in order to automatically achieve point-to-point correspondences between a scan point and the target center, a V-shaped target was designed as well. The bore-sight calibration parameters were estimated by a constrained least squares method, which iteratively minimizes the weighted sum of squares of residuals while constraining some highly-correlated parameters. The calibration performance was analyzed by means of a correlation matrix. After calibration, the visual inspection of mapped data and residual calculation confirmed the effectiveness of the proposed calibration approach. PMID:25946627

  3. Three-dimensional imaging of plant cuticle architecture using confocal scanning laser microscopy.

    PubMed

    Buda, Gregory J; Isaacson, Tal; Matas, Antonio J; Paolillo, Dominick J; Rose, Jocelyn K C

    2009-10-01

    Full appreciation of the roles of the plant cuticle in numerous aspects of physiology and development requires a comprehensive understanding of its biosynthesis and deposition; however, much is still not known about cuticle structure, trafficking and assembly. To date, assessment of cuticle organization has been dominated by 2D imaging, using histochemical stains in conjunction with light and fluorescence microscopy. This strategy, while providing valuable information, has limitations because it attempts to describe a complex 3D structure in 2D. An imaging technique that could accurately resolve 3D architecture would provide valuable additions to the growing body of information on cuticle molecular biology and biochemistry. We present a novel application of 3D confocal scanning laser microscopy for visualizing the architecture, deposition patterns and micro-structure of plant cuticles, using the fluorescent stain auramine O. We demonstrate the utility of this technique by contrasting the fruit cuticle of wild-type tomato (Solanum lycopersicum cv. M82) with those of cutin-deficient mutants. We also introduce 3D cuticle modeling based on reconstruction of serial optical sections, and describe its use in identification of several previously unreported features of the tomato fruit cuticle.

  4. Toward real-time virtual biopsy of oral lesions using confocal laser endomicroscopy interfaced with embedded computing

    NASA Astrophysics Data System (ADS)

    Thong, Patricia S. P.; Tandjung, Stephanus S.; Movania, Muhammad Mobeen; Chiew, Wei-Ming; Olivo, Malini; Bhuvaneswari, Ramaswamy; Seah, Hock-Soon; Lin, Feng; Qian, Kemao; Soo, Khee-Chee

    2012-05-01

    Oral lesions are conventionally diagnosed using white light endoscopy and histopathology. This can pose a challenge because the lesions may be difficult to visualise under white light illumination. Confocal laser endomicroscopy can be used for confocal fluorescence imaging of surface and subsurface cellular and tissue structures. To move toward real-time "virtual" biopsy of oral lesions, we interfaced an embedded computing system to a confocal laser endomicroscope to achieve a prototype three-dimensional (3-D) fluorescence imaging system. A field-programmable gated array computing platform was programmed to enable synchronization of cross-sectional image grabbing and Z-depth scanning, automate the acquisition of confocal image stacks and perform volume rendering. Fluorescence imaging of the human and murine oral cavities was carried out using the fluorescent dyes fluorescein sodium and hypericin. Volume rendering of cellular and tissue structures from the oral cavity demonstrate the potential of the system for 3-D fluorescence visualization of the oral cavity in real-time. We aim toward achieving a real-time virtual biopsy technique that can complement current diagnostic techniques and aid in targeted biopsy for better clinical outcomes.

  5. Large-scale three-dimensional measurement via combining 3D scanner and laser rangefinder.

    PubMed

    Shi, Jinlong; Sun, Zhengxing; Bai, Suqin

    2015-04-01

    This paper presents a three-dimensional (3D) measurement method of large-scale objects by integrating a 3D scanner and a laser rangefinder. The 3D scanner, used to perform partial section measurement, is fixed on a robotic arm which can slide on a guide rail. The laser rangefinder, used to compute poses of the 3D scanner, is rigidly connected to the 3D scanner. During large-scale measurement, after measuring a partial section, the 3D scanner is straightly moved forward along the guide rail to measure another section. Meanwhile, the poses of the 3D scanner are estimated according to its moved distance for different partial section alignments. The performance and effectiveness are evaluated by experiments.

  6. Laser welding on trough panel: 3D body part

    NASA Astrophysics Data System (ADS)

    Shirai, Masato; Hisano, Hirohiko

    2003-03-01

    Laser welding for automotive bodies has been introduced mainly by European car manufacturers since more than 10 years ago. Their purposes of laser welding introduction were mainly vehicle performance improvement and lightweight. And laser welding was applied to limited portion where shapes of panels are simple and easy to fit welded flanges. Toyota also has introduced laser welding onto 3 dimensional parts named trough panel since 1999. Our purpose of the introduction was common use of equipment. Trough panel has a complex shape and different shapes in each car type. In order to realize common use of welding equipment, we introduced parts locating equipment which had unique, small & simple jigs fo each car type and NC (Numerical Controlled) locators and air-cooled small laser head developed by ourselves to the trough welding process. Laser welding replaced spot welding and was applied linearly like stitches. Length of laser welding was determined according to comparison with statistic tensile strength and fatigue strength of spot welding.

  7. Laser multi-reflection confocal long focal-length measurement

    NASA Astrophysics Data System (ADS)

    Li, Zhigang; Qiu, Lirong; Zhao, Weiqian; Xiao, Yang

    2016-06-01

    We propose a new laser multi-reflection confocal focal-length measurement (MCFM) method to meet the requirements of a high-precision measurement for a long focal-length more than 2 m. It places an optical flat and a reflector behind the test lens for reflecting the measuring beam repeatedly, and then, uses the property that the peak points of confocal response curves precisely corresponds to the convergence points of a multi-reflected measuring beam to exactly identify the positions of the convergence points. Subsequently, it obtains the position variation of the reflector with a different number of reflections by a distance measuring instrument, and thereby achieving the high precise long focal-length measurement. The theoretical analyses and preliminary experimental results indicate that MCFM has a relative standard uncertainty of 0.066% for a test lens with the focal-length of 9.76 m. MCFM can provide a novel approach for the high-precision focal-length measurement.

  8. Confocal laser endomicroscopy in inflammatory bowel diseases: Dream or reality?

    PubMed Central

    De Palma, Giovanni Domenico; Rispo, Antonio

    2013-01-01

    Confocal laser endomicroscopy (CLE) is a newly introduced procedure that provide real-time, high-resolution imaging of the gastrointestinal mucosa during endoscopy, allowing the visualization of the pathology of the mucosal epithelium with its cellular and subcellular structures. Recently, the use of CLE was reported in the study of colonic mucosa in patients with inflammatory bowel diseases and in particular in patients affected by ulcerative colitis. CLE has the potential to have an important role in management of inflammatory bowel diseases (IBD) patients as it can be used to assess the grading of colitis and in detection of microscopic colitis in endoscopically silent segments. Moreover, CLE can be used in surveillance programs especially in high-risk patients. Finally, CLE has been effectively used in diagnosing a biliary dysplasia/neoplasia in patients with primary sclerosing cholangitis, a pathological condition frequently associated with IBD, with a coexisting bile duct stricture. PMID:24039350

  9. Confocal Laser Endomicroscopy for Diagnosis of Barrett’s Esophagus

    PubMed Central

    Neumann, Helmut; Langner, Cord; Neurath, Markus F.; Vieth, Michael

    2012-01-01

    Barrett’s esophagus (BE) is established as a premalignant condition in the distal esophagus. Current surveillance guidelines recommend random biopsies every 1–2 cm at intervals of 3–5 years. Advanced endoscopic imaging of BE underwent several technical revolutions within the last decade including broad-field (red-flag) techniques (e.g., chromoendoscopy) and small-field techniques with confocal laser endomicroscopy (CLE) at the forefront. In this review we will focus on advanced endoscopic imaging using CLE for the diagnosis and characterization of BE and associated neoplasia. In addition, we will critically discuss the technique of CLE and provide some tricks and hints for the daily routine practice of CLE for diagnosis of BE. PMID:22645719

  10. Laser confocal feedback tomography and nano-step height measurement

    PubMed Central

    Tan, Yidong; Wang, Weiping; Xu, Chunxin; Zhang, Shulian

    2013-01-01

    A promising method for tomography and step height measurement is proposed, which combines the high sensitivity of the frequency-shifted feedback laser and the axial positioning ability of confocal microscopy. By demodulating the feedback-induced intensity modulation signals, the obtained amplitude and phase information are used to respectively determine the coarse and fine measurement of the samples. Imaging the micro devices and biological samples by the demodulated amplitude, this approach is proved to be able to achieve the cross-sectional image in highly scattered mediums. And then the successful height measurement of nano-step on a glass-substrate grating by combination of both amplitude and phase information indicates its axial high resolution (better than 2 nm) in a non-ambiguous range of about ten microns. PMID:24145717

  11. Adaptive optics for confocal laser scanning microscopy with adjustable pinhole

    NASA Astrophysics Data System (ADS)

    Yoo, Han Woong; van Royen, Martin E.; van Cappellen, Wiggert A.; Houtsmuller, Adriaan B.; Verhaegen, Michel; Schitter, Georg

    2016-04-01

    The pinhole plays an important role in confocal laser scanning microscopy (CLSM) for adaptive optics (AO) as well as in imaging, where the size of the pinhole denotes a trade-off between out-of-focus rejection and wavefront distortion. This contribution proposes an AO system for a commercial CLSM with an adjustable square pinhole to cope with such a trade-off. The proposed adjustable pinhole enables to calibrate the AO system and to evaluate the imaging performance. Experimental results with fluorescence beads on the coverslip and at a depth of 40 μm in the human hepatocellular carcinoma cell spheroid demonstrate that the proposed AO system can improve the image quality by the proposed calibration method. The proposed pinhole intensity ratio also indicates the image improvement by the AO correction in intensity as well as resolution.

  12. Surface microstructure profilometry based on laser confocal feedback

    NASA Astrophysics Data System (ADS)

    Wang, Weiping; Zhang, Shulian; Li, Yan

    2015-10-01

    We demonstrate a surface microstructure profile measurement method, which utilizes the positioning ability of confocal technology and the high sensitivity of frequency-shift feedback of a microchip laser. The surface profile is measured by combination of the amplitude and phase information of the feedback light reflected by the sample. The amplitude information is used for coarse measurement and to determine the integral number of half lasing wavelengths contained in the sample profile variation. The phase information is used for fine measurement and to determine the fractional number. The measurement realizes both a large axial measuring range of tens of microns and a high axial resolution of ˜2 nm. Meanwhile, a heterodyne phase measurement approach is introduced to compensate for environmental disturbance and to realize high axial resolution measurement under common room conditions. The surface profile of a grating is measured and proves the feasibility of the method.

  13. Quantitative single-molecule imaging by confocal laser scanning microscopy.

    PubMed

    Vukojevic, Vladana; Heidkamp, Marcus; Ming, Yu; Johansson, Björn; Terenius, Lars; Rigler, Rudolf

    2008-11-25

    A new approach to quantitative single-molecule imaging by confocal laser scanning microscopy (CLSM) is presented. It relies on fluorescence intensity distribution to analyze the molecular occurrence statistics captured by digital imaging and enables direct determination of the number of fluorescent molecules and their diffusion rates without resorting to temporal or spatial autocorrelation analyses. Digital images of fluorescent molecules were recorded by using fast scanning and avalanche photodiode detectors. In this way the signal-to-background ratio was significantly improved, enabling direct quantitative imaging by CLSM. The potential of the proposed approach is demonstrated by using standard solutions of fluorescent dyes, fluorescently labeled DNA molecules, quantum dots, and the Enhanced Green Fluorescent Protein in solution and in live cells. The method was verified by using fluorescence correlation spectroscopy. The relevance for biological applications, in particular, for live cell imaging, is discussed.

  14. Adaptive-weighted cubic B-spline using lookup tables for fast and efficient axial resampling of 3D confocal microscopy images.

    PubMed

    Indhumathi, C; Cai, Y Y; Guan, Y Q; Opas, M; Zheng, J

    2012-01-01

    Confocal laser scanning microscopy has become a most powerful tool to visualize and analyze the dynamic behavior of cellular molecules. Photobleaching of fluorochromes is a major problem with confocal image acquisition that will lead to intensity attenuation. Photobleaching effect can be reduced by optimizing the collection efficiency of the confocal image by fast z-scanning. However, such images suffer from distortions, particularly in the z dimension, which causes disparities in the x, y, and z directions of the voxels with the original image stacks. As a result, reliable segmentation and feature extraction of these images may be difficult or even impossible. Image interpolation is especially needed for the correction of undersampling artifact in the axial plane of three-dimensional images generated by a confocal microscope to obtain cubic voxels. In this work, we present an adaptive cubic B-spline-based interpolation with the aid of lookup tables by deriving adaptive weights based on local gradients for the sampling nodes in the interpolation formulae. Thus, the proposed method enhances the axial resolution of confocal images by improving the accuracy of the interpolated value simultaneously with great reduction in computational cost. Numerical experimental results confirm the effectiveness of the proposed interpolation approach and demonstrate its superiority both in terms of accuracy and speed compared to other interpolation algorithms.

  15. Reducing Costs and Increasing Productivity in Ship Maintenance Using Product Lifecycle Management, 3D Laser Scanning and 3D Printing

    DTIC Science & Technology

    2014-03-01

    Advantages ........................................................ 28 7. 3D Printer Usage in the Department of Defense ................. 29 a. Army...28 Figure 17. 3D Printer Forecast (from 3D Systems, 2013) .................................... 29 Figure 18. History...Several companies, including 3D Systems and Stratasys, produce 3D printers for both personal and industrial use. In addition, open source models

  16. Pulsetrain-burst mode, ultrafast-laser interactions with 3D viable cell cultures as a model for soft biological tissues.

    PubMed

    Qian, Zuoming; Mordovanakis, Aghapi; Schoenly, Joshua E; Covarrubias, Andrés; Feng, Yuanfeng; Lilge, Lothar; Marjoribanks, Robin S

    2013-12-13

    A 3D living-cell culture in hydrogel has been developed as a standardized low-tensile-strength tissue proxy for study of ultrafast, pulsetrain-burst laser-tissue interactions. The hydrogel is permeable to fluorescent biomarkers and optically transparent, allowing viable and necrotic cells to be imaged in 3D by confocal microscopy. Good cell-viability allowed us to distinguish between typical cell mortality and delayed subcellular tissue damage (e.g., apoptosis and DNA repair complex formation), caused by laser irradiation. The range of necrosis depended on laser intensity, but not on pulsetrain-burst duration. DNA double-strand breaks were quantified, giving a preliminary upper limit for genetic damage following laser treatment.

  17. Laser direct writing 3D structures for microfluidic channels: flow meter and mixer

    NASA Astrophysics Data System (ADS)

    Lin, Chih-Lang; Liu, Yi-Jui; Lin, Zheng-Da; Wu, Bo-Long; Lee, Yi-Hsiung; Shin, Chow-Shing; Baldeck, Patrice L.

    2015-03-01

    The 3D laser direct-writing technology is aimed at the modeling of arbitrary three-dimensional (3D) complex microstructures by scanning a laser-focusing point along predetermined trajectories. Through the perspective technique, the details of designed 3D structures can be properly fabricated in a microchannel. This study introduces a direct reading flow meter and a 3D passive mixer fabricated by laser direct writing for microfluidic applications. The flow meter consists of two rod-shaped springs, a pillar, an anchor, and a wedge-shaped indicator, installed inside a microfluidic channel. The indicator is deflected by the flowing fluid while restrained by the spring to establish an equilibrium indication according to the flow rate. The measurement is readily carried out by optical microscopy observation. The 3D passive Archimedes-screw-shaped mixer is designed to disturb the laminar flow 3D direction for enhancing the mixing efficiency. The simulation results indicate that the screw provides 3D disturbance of streamlines in the microchannel. The mixing demonstration for fluids flowing in the micrchannel approximately agrees with the simulation result. Thanks to the advantage of the laser direct writing technology, this study performs the ingenious applications of 3D structures for microchannels.

  18. Fabrication of Conductive 3D Gold-Containing Microstructures via Direct Laser Writing.

    PubMed

    Blasco, Eva; Müller, Jonathan; Müller, Patrick; Trouillet, Vanessa; Schön, Markus; Scherer, Torsten; Barner-Kowollik, Christopher; Wegener, Martin

    2016-05-01

    3D conductive microstructures containing gold are fabricated by simultaneous photopolymerization and photoreduction via direct laser writing. The photoresist employed consists of water-soluble polymers and a gold precursor. The fabricated microstructures show good conductivity and are successfully employed for 3D connections between gold pads.

  19. Bioceramic 3D Implants Produced by Laser Assisted Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Lusquiños, Fernando; del Val, Jesús; Arias-González, Felipe; Comesaña, Rafael; Quintero, Félix; Riveiro, Antonio; Boutinguiza, Mohamed; Jones, Julian R.; Hill, Robert G.; Pou, Juan

    Cranial defect restoration requires a suitable implant capable to fulfill protective and aesthetic functions, such as polymeric and metallic implants. Nevertheless, the former materials cannot provide osteointegration of the implant within the host bone nor implant resorption, which is also required in pediatricorthopedics for normal patient growth. Resorbable and osteoconductivebioceramics are employed, such as silicate bioactive glasses. Nevertheless, manufacturing based on conventional casting in graphite moulds is not effective for warped shape implants suitable for patient tailored treatments. In this work, we analyze the application of rapid prototyping based on laser cladding to manufacture bioactive glass implants for low load bearing bone restoration. This laser-assisted additive technique is capable to produce three-dimensional geometries tailored to patient, with reduced fabrication time and implant composition modification. The obtained samples were characterized; the relationships between the processing conditions and the measured features were studied, in addition to the biological behavior analysis.

  20. Laser Provides First 3-D View of Mars' North Pole

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This first three-dimensional picture of Mars' north pole enables scientists to estimate the volume of its water ice cap with unprecedented precision, and to study its surface variations and the heights of clouds in the region for the first time.

    Approximately 2.6 million of these laser pulse measurements were assembled into a topographic grid of the north pole with a spatial resolution of 0.6 miles (one kilometer) and a vertical accuracy of 15-90 feet (5-30 meters).

    The principal investigator for MOLA is Dr. David E. Smith of Goddard. The MOLA instrument was designed and built by the Laser Remote Sensing Branch of Laboratory for Terrestrial Physics at Goddard. The Mars Global Surveyor Mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for the NASA Office of Space Science.

  1. Investigation Into the Utilization of 3D Printing in Laser Cooling Experiments

    NASA Astrophysics Data System (ADS)

    Hazlett, Eric; Nelson, Brandon; de Leon, Sam Diaz; Shaw, Jonah

    2016-05-01

    With the advancement of 3D printing new opportunities are abound in many different fields, but with the balance between the precisions of atomic physics experiments and the material properties of current 3D printers the benefit of 3D printing technology needs to be investigated. We report on the progress of two investigations of 3D printing of benefit to atomic physics experiments: laser feedback module and the other being an optical chopper. The first investigation looks into creation of a 3D printed laser diode feedback module. This 3D printed module would allow for the quick realization of an external cavity diode laser that would have an adjustable cavity distance. We will report on the first tests of this system, by looking at Rb spectroscopy and mode-hop free tuning range as well as possibilities of using these lasers for MOT generation. We will also discuss our investigation into a 3D-printed optical chopper that utilizes an Arduino and a computer hard drive motor. By implementing an additional Arduino we create a low cost way to quickly measure laser beam waists.

  2. Investigation Into the Utilization of 3D Printing in Laser Cooling Experiments

    NASA Astrophysics Data System (ADS)

    Hazlett, Eric

    With the advancement of 3D printing new opportunities are abound in many different fields, but with the balance between the precisions of atomic physics experiments and the material properties of current 3D printers the benefit of 3D printing technology needs to be investigated. We report on the progress of two investigations of 3D printing of benefit to atomic physics experiments: laser feedback module and the other being an optical chopper. The first investigation looks into creation of a 3D printed laser diode feedback module. This 3D printed module would allow for the quick realization of an external cavity diode laser that would have an adjustable cavity distance. We will report on the first tests of this system, by looking at Rb spectroscopy and mode-hop free tuning range as well as possibilities of using these lasers for MOT generation. We will also discuss our investigation into a 3D-printed optical chopper that utilizes an Arduino and a computer hard drive motor. By implementing an additional Arduino we create a low cost way to quickly measure laser beam waists

  3. 3D photomechanical model of tooth enamel ablation by Er-laser radiation

    NASA Astrophysics Data System (ADS)

    Belikov, Andrey V.; Shatilova, Ksenia V.; Skrypnik, Alexei V.

    2014-02-01

    The three-dimensional (3D) photomechanical model of human tooth enamel ablation is described. It takes into account: the structural peculiarities of enamel, Er-laser beam energy spatial distribution and laser radiation attenuation in the tissue. Dynamics change of enamel coefficient of absorption during ablation is also discussed. We consider the 3D photomechanical model of incomplete removal (modification) of the enamel rods by the pressure of water contained in the enamel pores and heated by laser radiation, and complete removal (ablation) of the enamel rods as result of hydroxyapatite heated by laser radiation and evaporation. Modeling results are in close agreement with the experimental results.

  4. Laser-assisted direct ink writing of planar and 3D metal architectures

    NASA Astrophysics Data System (ADS)

    Skylar-Scott, Mark A.; Gunasekaran, Suman; Lewis, Jennifer A.

    2016-05-01

    The ability to pattern planar and freestanding 3D metallic architectures at the microscale would enable myriad applications, including flexible electronics, displays, sensors, and electrically small antennas. A 3D printing method is introduced that combines direct ink writing with a focused laser that locally anneals printed metallic features “on-the-fly.” To optimize the nozzle-to-laser separation distance, the heat transfer along the printed silver wire is modeled as a function of printing speed, laser intensity, and pulse duration. Laser-assisted direct ink writing is used to pattern highly conductive, ductile metallic interconnects, springs, and freestanding spiral architectures on flexible and rigid substrates.

  5. Laser-assisted direct ink writing of planar and 3D metal architectures.

    PubMed

    Skylar-Scott, Mark A; Gunasekaran, Suman; Lewis, Jennifer A

    2016-05-31

    The ability to pattern planar and freestanding 3D metallic architectures at the microscale would enable myriad applications, including flexible electronics, displays, sensors, and electrically small antennas. A 3D printing method is introduced that combines direct ink writing with a focused laser that locally anneals printed metallic features "on-the-fly." To optimize the nozzle-to-laser separation distance, the heat transfer along the printed silver wire is modeled as a function of printing speed, laser intensity, and pulse duration. Laser-assisted direct ink writing is used to pattern highly conductive, ductile metallic interconnects, springs, and freestanding spiral architectures on flexible and rigid substrates.

  6. Laser-assisted direct ink writing of planar and 3D metal architectures

    PubMed Central

    Skylar-Scott, Mark A.; Gunasekaran, Suman; Lewis, Jennifer A.

    2016-01-01

    The ability to pattern planar and freestanding 3D metallic architectures at the microscale would enable myriad applications, including flexible electronics, displays, sensors, and electrically small antennas. A 3D printing method is introduced that combines direct ink writing with a focused laser that locally anneals printed metallic features “on-the-fly.” To optimize the nozzle-to-laser separation distance, the heat transfer along the printed silver wire is modeled as a function of printing speed, laser intensity, and pulse duration. Laser-assisted direct ink writing is used to pattern highly conductive, ductile metallic interconnects, springs, and freestanding spiral architectures on flexible and rigid substrates. PMID:27185932

  7. Toward 3D Printing of Pure Metals by Laser-Induced Forward Transfer.

    PubMed

    Visser, Claas Willem; Pohl, Ralph; Sun, Chao; Römer, Gert-Willem; Huis in 't Veld, Bert; Lohse, Detlef

    2015-07-15

    3D printing of common metals is highly challenging because metals are generally solid at room conditions. Copper and gold pillars are manufactured with a resolution below 5 μm and a height up to 2 mm, using laser-induced forward transfer to create and eject liquid metal droplets. The solidified drop's shape is crucial for 3D printing and is discussed as a function of the laser energy.

  8. Determination of Percent Body Fat Using 3D Whole Body Laser Scanning: A Preliminary Investigation

    DTIC Science & Technology

    2006-11-01

    circumferences, 3D whole body laser scans and DEXA scans were performed on fifty-one men and women age 18-62. Mean percent body fat was not statistically...3D whole body laser scan , and DEXA scan to measure individuals during a one hour measurement session. 1 Report Documentation Page Form...underwent a 6 minute whole body DEXA scan using a GE Lunar Prodigy DEXA scanner running software version 7.53. Percent body fat was calculated from the

  9. 3D reconstruction with two webcams and a laser line projector

    NASA Astrophysics Data System (ADS)

    Li, Dongdong; Hui, Bingwei; Qiu, Shaohua; Wen, Gongjian

    2014-09-01

    Three-dimensional (3D) reconstruction is one of the most attractive research topics in photogrammetry and computer vision. Nowadays 3D reconstruction with simple and consumable equipment plays an important role. In this paper, a 3D reconstruction desktop system is built based on binocular stereo vision using a laser scanner. The hardware requirements are a simple commercial hand-held laser line projector and two common webcams for image acquisition. Generally, 3D reconstruction based on passive triangulation methods requires point correspondences among various viewpoints. The development of matching algorithms remains a challenging task in computer vision. In our proposal, with the help of a laser line projector, stereo correspondences are established robustly from epipolar geometry and the laser shadow on the scanned object. To establish correspondences more conveniently, epipolar rectification is employed using Bouguet's method after stereo calibration with a printed chessboard. 3D coordinates of the observed points are worked out with rayray triangulation and reconstruction outliers are removed with the planarity constraint of the laser plane. Dense 3D point clouds are derived from multiple scans under different orientations. Each point cloud is derived by sweeping the laser plane across the object requiring 3D reconstruction. The Iterative Closest Point algorithm is employed to register the derived point clouds. Rigid body transformation between neighboring scans is obtained to get the complete 3D point cloud. Finally polygon meshes are reconstructed from the derived point cloud and color images are used in texture mapping to get a lifelike 3D model. Experiments show that our reconstruction method is simple and efficient.

  10. Formation and properties of 3D metamaterial composites fabricated using nanometer scale laser lithography (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Prokes, Sharka M.; Perkins, Frank K.; Glembocki, Orest J.

    2015-08-01

    Metamaterials designed for the visible or near IR wavelengths require patterning on the nanometer scale. To achieve this, e-beam lithography is used, but it is extremely difficult and can only produce 2D structures. A new alternative technique to produce 2D and 3D structures involves laser fabrication using the Nanoscribe 3D laser lithography system. This is a direct laser writing technique which can form arbitrary 3D nanostructures on the nanometer scale and is based on multi-photon polymerization. We are creating 2D and 3D metamaterials via this technique, and subsequently conformally coating them using Atomic Layer Deposition of oxides and Ag. We will discuss the optical properties of these novel composite structures and their potential for dual resonant metamaterials.

  11. High-speed 3-D measurement with a large field of view based on direct-view confocal microscope with an electrically tunable lens.

    PubMed

    Jeong, Hyeong-jun; Yoo, Hongki; Gweon, DaeGab

    2016-02-22

    We propose a new structure of confocal imaging system based on a direct-view confocal microscope (DVCM) with an electrically tunable lens (ETL). Since it has no mechanical moving parts to scan both the lateral (x-y) and axial (z) directions, the DVCM with an ETL allows for high-speed 3-dimensional (3-D) imaging. Axial response and signal intensity of the DVCM were analyzed theoretically according to the pinhole characteristics. The system was designed to have an isotropic spatial resolution of 20 µm in both lateral and axial direction with a large field of view (FOV) of 10 × 10 mm. The FOV was maintained according to the various focal shifts as a result of an integrated design of an objective lens with the ETL. The developed system was calibrated to have linear focal shift over a range of 9 mm with an applied current to the ETL. The system performance of 3-D volume imaging was demonstrated using standard height specimens and a dental plaster.

  12. Filtering method for 3D laser scanning point cloud

    NASA Astrophysics Data System (ADS)

    Liu, Da; Wang, Li; Hao, Yuncai; Zhang, Jun

    2015-10-01

    In recent years, with the rapid development of the hardware and software of the three-dimensional model acquisition, three-dimensional laser scanning technology is utilized in various aspects, especially in space exploration. The point cloud filter is very important before using the data. In the paper, considering both the processing quality and computing speed, an improved mean-shift point cloud filter method is proposed. Firstly, by analyze the relevance of the normal vector between the upcoming processing point and the near points, the iterative neighborhood of the mean-shift is selected dynamically, then the high frequency noise is constrained. Secondly, considering the normal vector of the processing point, the normal vector is updated. Finally, updated position is calculated for each point, then each point is moved in the normal vector according to the updated position. The experimental results show that the large features are retained, at the same time, the small sharp features are also existed for different size and shape of objects, so the target feature information is protected precisely. The computational complexity of the proposed method is not high, it can bring high precision results with fast speed, so it is very suitable for space application. It can also be utilized in civil, such as large object measurement, industrial measurement, car navigation etc. In the future, filter with the help of point strength will be further exploited.

  13. A hand-held 3D laser scanning with global positioning system of subvoxel precision

    NASA Astrophysics Data System (ADS)

    Arias, Néstor; Meneses, Néstor; Meneses, Jaime; Gharbi, Tijani

    2011-01-01

    In this paper we propose a hand-held 3D laser scanner composed of an optical head device to extract 3D local surface information and a stereo vision system with subvoxel precision to measure the position and orientation of the 3D optical head. The optical head is manually scanned over the surface object by the operator. The orientation and position of the 3D optical head is determined by a phase-sensitive method using a 2D regular intensity pattern. This phase reference pattern is rigidly fixed to the optical head and allows their 3D location with subvoxel precision in the observation field of the stereo vision system. The 3D resolution achieved by the stereo vision system is about 33 microns at 1.8 m with an observation field of 60cm x 60cm.

  14. Confocal laser scanning microscopy in study of bone calcification

    NASA Astrophysics Data System (ADS)

    Nishikawa, Tetsunari; Kokubu, Mayu; Kato, Hirohito; Imai, Koichi; Tanaka, Akio

    2012-12-01

    Bone regeneration in mandible and maxillae after extraction of teeth or tumor resection and the use of rough surface implants in bone induction must be investigated to elucidate the mechanism of calcification. The calcified tissues are subjected to chemical decalcification or physical grinding to observe their microscopic features with light microscopy and transmission electron microscopy where the microscopic tissue morphology is significantly altered. We investigated the usefulness of confocal laser scanning microscopy (CLSM) for this purpose. After staggering the time of administration of calcein and alizarin red to experimental rats and dogs, rat alveolar bone and dog femur grafted with coral as scaffold or dental implants were observed with CLSM. In rat alveolar bone, the calcification of newly-formed bone and net-like canaliculi was observed at the mesial bone from the roots progressed at the rate of 15 μm/day. In dog femur grafted with coral, newly-formed bones along the space of coral were observed in an orderly manner. In dog femur with dental implants, after 8 weeks, newly-formed bone proceeded along the rough surface of the implants. CLSM produced high-magnification images of newly-formed bone and thin sections were not needed.

  15. Semiquantitative confocal laser scanning microscopy applied to marine invertebrate ecotoxicology.

    PubMed

    Chandler, G Thomas; Volz, David C

    2004-01-01

    Confocal laser scanning microscopy (CLSM) represents a powerful, but largely unexplored ecotoxicologic tool for rapidly assessing in vivo effects of toxicants on marine invertebrate embryo quality and development. We describe here a new semiquantitative CLSM approach for assessing relative yolk quantity in marine invertebrate embryos (harpacticoid copepods) produced by parents reared from hatching to adult in the polycylic aromatic hydrocarbon chrysene. This method is based on fluorogenic labeling of embryo yolk and subsequent statistical analysis of areal pixel intensities over multiple Z-series using a general linear model (GLM)-nested analysis of variance. The fluorescent yolk-labeling method described here was able to detect statistically significant differences in yolk concentrations in marine copepod (Amphiascus tenuiremis) eggs or embryos from females exposed to ultraviolet light and chrysene-contaminated sediments. Yolk intensities in embryos from females cultured throughout their life cycles in clean sediments were statistically identical with or without UV exposure. In contrast, yolk intensities in embryos of females cultured throughout their life cycle in chrysene-contaminated sediments were significantly higher in the non-UV-exposed treatment with chrysene at 2500 ng/g sediment (65.7% higher) and the UV-exposed treatment with chrysene at 500 ng/g sediment (76.6% higher).

  16. Intracellular phthalocyanine localization: confocal laser scanning microscopy studies

    NASA Astrophysics Data System (ADS)

    Chernyaeva, Elena B.; Greve, Jan; de Grooth, Bart G.; Van Leeuwen, A. G.

    1994-02-01

    Phthalocyanines (Pc) are promising second-generation photosensitizers for the photodynamic therapy (PDT) of cancer. We report on the tetrasulfonated aluminum phthalocyanine (AlPcS4) localization in cultured Chinese hamster lung cells studied by means of confocal laser scanning microscopy (CLSM). In these cells AlPcS4 was found in granules surrounding Golgi apparatus and in the peripheral cytoplasmic region. Peripheral Pc-containing granules partially coincided with the acidic cellular compartments. The effect of irradiation with light on Pc intracellular distribution was also studied. In the Pc-free medium disruption of some Pc- containing granules was observed followed by appearance of Pc fluorescence in the cell plasma membrane, the nuclear envelope, and the near-nuclear region. When cells were irradiated in the presence of Pc in external medium a drastic increase of membrane permeability to Pc was observed, followed by Pc binding the cell plasma membrane, nuclear envelope, and some structures in the cytoplasm. Diffusive Pc fluorescence in the nucleus was also observed. The implication of observed Pc redistribution caused by irradiation with light for the PDT protocol is discussed.

  17. Confocal laser endomicroscopy features of sessile serrated adenomas/polyps

    PubMed Central

    Parikh, Neil D; Gibson, Joanna; Nagar, Anil; Ahmed, Ali A

    2015-01-01

    Background and aims Sessile serrated adenomas/polyps (SSA/Ps) are difficult to differentiate from non-neoplastic tissue on white-light endoscopy. Confocal laser endomicroscopy (CLE) provides subcellular imaging and real-time “optical biopsy”. The aim of this study was to prospectively describe CLE features of SSA/Ps. Patients and methods Consecutive patients with SSA/Ps were prospectively evaluated with probe-based CLE imaging. CLE images and polyp histology were independently reviewed by three endoscopists and an expert gastrointestinal (GI) pathologist. Distinguishing CLE features of SSA/Ps were identified in conjunction with pathologic correlation. Results In total, 260 CLE images were generated from nine SSA/Ps evaluated in seven patients. Four consensus CLE features of SSA/P were identified: (1) a mucus cap with a bright, cloud-like appearance; (2) thin, branching crypts; (3) increased number of goblet cells and microvesicular mucin-containing cells; and (4) architectural disarray, with dystrophic goblet cells and lack of regular circular crypts Conclusion This is a novel description of characteristic CLE features of SSA/Ps. The four features we identified are easy to detect and may allow for CLE to serve as a diagnostic modality. PMID:27536371

  18. Laser ablation of basal cell carcinomas guided by confocal microscopy

    NASA Astrophysics Data System (ADS)

    Sierra, Heidy; Cordova, Miguel; Nehal, Kishwer; Rossi, Anthony; Chen, Chih-Shan Jason; Rajadhyaksha, Milind

    2016-02-01

    Laser ablation offers precise and fast removal of superficial and early nodular types of basal cell carcinomas (BCCs). Nevertheless, the lack of histological confirmation has been a limitation. Reflectance confocal microscopy (RCM) imaging combined with a contrast agent can offer cellular-level histology-like feedback to detect the presence (or absence) of residual BCC directly on the patient. We conducted an ex vivo bench-top study to provide a set of effective ablation parameters (fluence, number of passes) to remove superficial BCCs while also controlling thermal coagulation post-ablation to allow uptake of contrast agent. The results for an Er:YAG laser (2.9 um and pulse duration 250us) show that with 6 passes of 25 J/cm2, thermal coagulation can be effectively controlled, to allow both the uptake of acetic acid (contrast agent) and detection of residual (or absence) BCCs. Confirmation was provided with histological examination. An initial in vivo study on 35 patients shows that the uptake of contrast agent aluminum chloride) and imaging quality is similar to that observed in the ex vivo study. The detection of the presence of residual tumor or complete clearance was confirmed in 10 wounds with (additional) histology and in 25 lesions with follow-up imaging. Our results indicate that resolution is sufficient but further development and use of appropriate contrast agent are necessary to improve sensitivity and specificity. Advances in RCM technology for imaging of lateral and deep margins directly on the patient may provide less invasive, faster and less expensive image-guided approaches for treatment of BCCs.

  19. Beat the diffraction limit in 3D direct laser writing in photosensitive glass.

    PubMed

    Bellec, Matthieu; Royon, Arnaud; Bousquet, Bruno; Bourhis, Kevin; Treguer, Mona; Cardinal, Thierry; Richardson, Martin; Canioni, Lionel

    2009-06-08

    Three-dimensional (3D) femtosecond laser direct structuring in transparent materials is widely used for photonic applications. However, the structure size is limited by the optical diffraction. Here we report on a direct laser writing technique that produces subwavelength nanostructures independently of the experimental limiting factors. We demonstrate 3D nanostructures of arbitrary patterns with feature sizes down to 80 nm, less than one tenth of the laser processing wavelength. Its ease of implementation for novel nanostructuring, with its accompanying high precision will open new opportunities for the fabrication of nanostructures for plasmonic and photonic devices and for applications in metamaterials.

  20. The investigation of the dynamic morphology of block copolymer solutions by laser scanning confocal microscopy (LSCM)

    NASA Astrophysics Data System (ADS)

    Lee, Hyunjung

    2005-03-01

    Recently we applied laser scanning confocal microscopy (LSCM) for the study of block copolymer 3D morphology. Besides static measurement of microstructures (direct 3-D imaging of block copolymer morphology), LSCM also enables the tracking of the fast dynamic process which has been impossible by conventional microscopic techniques such as TEM (transmission electron microscopy) or AFM (atomic force microscopy). In this study, in-situ LSCM investigation of the morphology of confined photonic BCP solution was performed in conjunction with spectroscopic measurement for the first time. When a lamellar forming polystyrene-b-isoprene (480k-360k, PS/PI) in cumene was placed between cover glasses, the continuous evaporation of the solvent induced a shear field along the radial direction (evaporation direction). As a result, the photonic lamellar BCP solution over the whole area developed a series of concentric ring pattern covering entire visible colors (blue to red). Comparison of the experimental result with theoretical calculation (transfer matrix method) revealed that this phenomenon mainly comes from the change of the orientation of BCP lamella based on the reflectivity at each region along the radius..

  1. Presynaptic structure of Aplysia single live neuron by atomic force and confocal laser scanning microscope.

    PubMed

    Park, Aee-Young; Chae, Yeon-Su; Lee, Seung-Hee; Kaang, Bong-Kiun; Lee, Seonghoon

    2013-05-02

    The structural and functional plasticity of Aplysia mechanosensory presynaptic neurons has been studied in relation with the mechanism underlying learning and memory. Long-term facilitation (LTF), which is a well-known cellular model for long-term memory in Aplysia, is accompanied by new synaptic structural growth or change. We developed a combined atomic force microscope and confocal laser scanning microscope (AFM-CLSM) system integrated with a MATLAB routine for image processing to concurrently obtain high-resolution 3-dimensional (3D) outer-surface morphological images and 3D interior fluorescence images. With our combined AFM-CLSM system, volumetric changes in the presynaptic structures (varicosities) of Aplysia live sensory-motor neuron cocultures were observed. The spatial distribution of synaptic vesicle molecules in the preexisting varicosities was monitored together with a volumetric change in the varicosities. Our combined AFM-CLSM system is successfully adapted for measuring learning-related structural changes and the movement of synaptic molecules in the single live neuron through interaction force and fluorescence imaging.

  2. CONFOCAL LASER SCANNING MICROSCOPY OF APOPTOSIS IN WHOLE MOUSE AND RAT OVARIES

    EPA Science Inventory

    Confocal Laser Scanning Microscopy of Apoptosis in Whole Mouse and Rat Ovaries. Robert M. Zucker Susan C. Jeffay and Sally D. Perreault Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research ...

  3. Laser nanostructuring 3-D bioconstruction based on carbon nanotubes in a water matrix of albumin

    NASA Astrophysics Data System (ADS)

    Gerasimenko, Alexander Y.; Ichkitidze, Levan P.; Podgaetsky, Vitaly M.; Savelyev, Mikhail S.; Selishchev, Sergey V.

    2016-04-01

    3-D bioconstructions were created using the evaporation method of the water-albumin solution with carbon nanotubes (CNTs) by the continuous and pulsed femtosecond laser radiation. It is determined that the volume structure of the samples created by the femtosecond radiation has more cavities than the one created by the continuous radiation. The average diameter for multi-walled carbon nanotubes (MWCNTs) samples was almost two times higher (35-40 nm) than for single-walled carbon nanotubes (SWCNTs) samples (20-30 nm). The most homogenous 3-D bioconstruction was formed from MWCNTs by the continuous laser radiation. The hardness of such samples totaled up to 370 MPa at the nanoscale. High strength properties and the resistance of the 3-D bioconstructions produced by the laser irradiation depend on the volume nanotubes scaffold forming inside them. The scaffold was formed by the electric field of the directed laser irradiation. The covalent bond energy between the nanotube carbon molecule and the oxygen of the bovine serum albumin aminoacid residue amounts 580 kJ/mol. The 3-D bioconstructions based on MWCNTs and SWCNTs becomes overgrown with the cells (fibroblasts) over the course of 72 hours. The samples based on the both types of CNTs are not toxic for the cells and don't change its normal composition and structure. Thus the 3-D bioconstructions that are nanostructured by the pulsed and continuous laser radiation can be applied as implant materials for the recovery of the connecting tissues of the living body.

  4. Laparoscopic manipulation of a probe-based confocal laser endomicroscope using a steerable intravascular catheter.

    PubMed

    Schneider, Crispin; Desjardins, Adrien E; Gurusamy, Kurinchi; Hawkes, David J; Davidson, Brian R

    2015-04-01

    Probe-based confocal laser endomicroscopy is an emerging imaging modality that enables visualization of histologic details during endoscopy and surgery. A method of guiding the probe with millimeter accuracy is required to enable imaging in all regions of the abdomen accessed during laparoscopy. On the basis of a porcine model of laparoscopic liver resection, we report our experience of using a steerable intravascular catheter to guide a probe-based confocal laser endomicroscope.

  5. Laparoscopic Manipulation of a Probe-based Confocal Laser Endomicroscope Using a Steerable Intravascular Catheter

    PubMed Central

    Desjardins, Adrien E.; Gurusamy, Kurinchi; Hawkes, David J.; Davidson, Brian R.

    2015-01-01

    Probe-based confocal laser endomicroscopy is an emerging imaging modality that enables visualization of histologic details during endoscopy and surgery. A method of guiding the probe with millimeter accuracy is required to enable imaging in all regions of the abdomen accessed during laparoscopy. On the basis of a porcine model of laparoscopic liver resection, we report our experience of using a steerable intravascular catheter to guide a probe-based confocal laser endomicroscope. PMID:25807277

  6. Highlighting the impact of aging on type I collagen: label-free investigation using confocal reflectance microscopy and diffuse reflectance spectroscopy in 3D matrix model.

    PubMed

    Guilbert, Marie; Roig, Blandine; Terryn, Christine; Garnotel, Roselyne; Jeannesson, Pierre; Sockalingum, Ganesh D; Manfait, Michel; Perraut, François; Dinten, Jean-Marc; Koenig, Anne; Piot, Olivier

    2016-02-23

    During aging, alterations of extracellular matrix proteins contribute to various pathological phenotypes. Among these alterations, type I collagen cross-linking and associated glycation products accumulation over time detrimentally affects its physico-chemical properties, leading to alterations of tissue biomechanical stability. Here, different-age collagen 3D matrices using non-destructive and label-free biophotonic techniques were analysed to highlight the impact of collagen I aging on 3D constructs, at macroscopic and microscopic levels. Matrices were prepared with collagens extracted from tail tendons of rats (newborns, young and old adults) to be within the physiological aging process. The data of diffuse reflectance spectroscopy reveal that aging leads to an inhibition of fibril assembly and a resulting decrease of gel density. Investigations by confocal reflectance microscopy highlight poor-fibrillar structures in oldest collagen networks most likely related to the glycation products accumulation. Complementarily, an infrared analysis brings out marked spectral variations in the Amide I profile, specific of the peptidic bond conformation and for carbohydrates vibrations as function of collagen-age. Interestingly, we also highlight an unexpected behavior for newborn collagen, exhibiting poorly-organized networks and microscopic features close to the oldest collagen. These results demonstrate that changes in collagen optical properties are relevant for investigating the incidence of aging in 3D matrix models.

  7. Highlighting the impact of aging on type I collagen: label-free investigation using confocal reflectance microscopy and diffuse reflectance spectroscopy in 3D matrix model

    PubMed Central

    Terryn, Christine; Garnotel, Roselyne; Jeannesson, Pierre; Sockalingum, Ganesh D.; Manfait, Michel; Perraut, François; Dinten, Jean-Marc; Koenig, Anne; Piot, Olivier

    2016-01-01

    During aging, alterations of extracellular matrix proteins contribute to various pathological phenotypes. Among these alterations, type I collagen cross-linking and associated glycation products accumulation over time detrimentally affects its physico-chemical properties, leading to alterations of tissue biomechanical stability. Here, different-age collagen 3D matrices using non-destructive and label-free biophotonic techniques were analysed to highlight the impact of collagen I aging on 3D constructs, at macroscopic and microscopic levels. Matrices were prepared with collagens extracted from tail tendons of rats (newborns, young and old adults) to be within the physiological aging process. The data of diffuse reflectance spectroscopy reveal that aging leads to an inhibition of fibril assembly and a resulting decrease of gel density. Investigations by confocal reflectance microscopy highlight poor-fibrillar structures in oldest collagen networks most likely related to the glycation products accumulation. Complementarily, an infrared analysis brings out marked spectral variations in the Amide I profile, specific of the peptidic bond conformation and for carbohydrates vibrations as function of collagen-age. Interestingly, we also highlight an unexpected behavior for newborn collagen, exhibiting poorly-organized networks and microscopic features close to the oldest collagen. These results demonstrate that changes in collagen optical properties are relevant for investigating the incidence of aging in 3D matrix models. PMID:26885896

  8. Laser Transfer of Metals and Metal Alloys for Digital Microfabrication of 3D Objects.

    PubMed

    Zenou, Michael; Sa'ar, Amir; Kotler, Zvi

    2015-09-02

    3D copper logos printed on epoxy glass laminates are demonstrated. The structures are printed using laser transfer of molten metal microdroplets. The example in the image shows letters of 50 µm width, with each letter being taller than the last, from a height of 40 µm ('s') to 190 µm ('l'). The scanning microscopy image is taken at a tilt, and the topographic image was taken using interferometric 3D microscopy, to show the effective control of this technique.

  9. Laser fabrication of 2D and 3D metal nanoparticle structures and arrays.

    PubMed

    Kuznetsov, A I; Kiyan, R; Chichkov, B N

    2010-09-27

    A novel method for fabrication of 2D and 3D metal nanoparticle structures and arrays is proposed. This technique is based on laser-induced transfer of molten metal nanodroplets from thin metal films. Metal nanoparticles are produced by solidification of these nanodroplets. The size of the transferred nanoparticles can be controllably changed in the range from 180 nm to 1500 nm. Several examples of complex 2D and 3D microstructures generated form gold nanoparticles are demonstrated.

  10. Fabrication of 3D embedded hollow structures inside polymer dielectric PMMA with femtosecond laser

    NASA Astrophysics Data System (ADS)

    Zheng, Chong; Chen, Tao; Hu, Anming; Liu, Shibing; Li, Junwei

    2016-11-01

    Recent progresses in femtosecond laser (fs) manufacturing have already proved that fs laser is a powerful tool in three dimensional internal structure fabrications. However, most studies are mainly focused on realize such structures in inorganic transparent dielectric, such as photosensitive glass and fused silica, etc. In this study, we present two methods to fabricate embedded internal 3D structures in a polymer dielectric material polymethyl methacrylate (PMMA). Both continuous hollow structure such as microfluidic channels and discrete hollow structures such as single microcavities are successfully fabricated with the help of femtosecond lasers. Among them, complicated 3D microchannel with a total length longer than 10mm and diameters around 80μm to 200μm are fabricated with a low repetition rate Ti: sapphire femtosecond laser by direct laser writing at a speed ranging from 25μm/s to 2000μm/s microcavities which function as concave microball lenses (CMBLs) and can be applied in super-wide-angle imaging are fabricated with a high repetition rate femtosecond fiber laser due to the distinct heat accumulation effect after 5s irradiation with the tightly focused fs laser beam. These new approaches proved that femtosecond laser direct writing technology has great application potential in 3D integrated devices manufacturing in the future.

  11. The research of 3D visualization techniques for the test of laser energy distribution

    NASA Astrophysics Data System (ADS)

    Liu, Lixin; Wang, Bo

    2013-07-01

    In the process of laser transmission in the atmosphere, the complexity and instability of the atmospheric composition that seriously interfere with, even change, the performance of the laser beam. The image of laser energy distribution can be captured and analyzed through infrared CCD and digital image processing technology. The basic features of laser energy density distribution, such as the location and power of the peak point and other basic parameters could be acquired; laser energy density distribution can display in real time continuous multi-frame; the 3D visualization of pseudo-color for laser energy density distribution could be displayed, that reflect the relative size and position of the energy distribution in the different regions of the laser spot, using the VC++, windows APIs and OpenGL programming. The laser energy density distribution can be observed from all angles.

  12. Indoor space 3D visual reconstruction using mobile cart with laser scanner and cameras

    NASA Astrophysics Data System (ADS)

    Gashongore, Prince Dukundane; Kawasue, Kikuhito; Yoshida, Kumiko; Aoki, Ryota

    2017-02-01

    Indoor space 3D visual reconstruction has many applications and, once done accurately, it enables people to conduct different indoor activities in an efficient manner. For example, an effective and efficient emergency rescue response can be accomplished in a fire disaster situation by using 3D visual information of a destroyed building. Therefore, an accurate Indoor Space 3D visual reconstruction system which can be operated in any given environment without GPS has been developed using a Human-Operated mobile cart equipped with a laser scanner, CCD camera, omnidirectional camera and a computer. By using the system, accurate indoor 3D Visual Data is reconstructed automatically. The obtained 3D data can be used for rescue operations, guiding blind or partially sighted persons and so forth.

  13. A Laser Line Auto-Scanning System for Underwater 3D Reconstruction.

    PubMed

    Chi, Shukai; Xie, Zexiao; Chen, Wenzhu

    2016-09-20

    In this study, a laser line auto-scanning system was designed to perform underwater close-range 3D reconstructions with high accuracy and resolution. The system changes the laser plane direction with a galvanometer to perform automatic scanning and obtain continuous laser strips for underwater 3D reconstruction. The system parameters were calibrated with the homography constraints between the target plane and image plane. A cost function was defined to optimize the galvanometer's rotating axis equation. Compensation was carried out for the refraction of the incident and emitted light at the interface. The accuracy and the spatial measurement capability of the system were tested and analyzed with standard balls under laboratory underwater conditions, and the 3D surface reconstruction for a sealing cover of an underwater instrument was proved to be satisfactory.

  14. Fabrication of 3D solenoid microcoils in silica glass by femtosecond laser wet etch and microsolidics

    NASA Astrophysics Data System (ADS)

    Meng, Xiangwei; Yang, Qing; Chen, Feng; Shan, Chao; Liu, Keyin; Li, Yanyang; Bian, Hao; Du, Guangqing; Hou, Xun

    2015-02-01

    This paper reports a flexible fabrication method for 3D solenoid microcoils in silica glass. The method consists of femtosecond laser wet etching (FLWE) and microsolidics process. The 3D microchannel with high aspect ratio is fabricated by an improved FLWE method. In the microsolidics process, an alloy was chosen as the conductive metal. The microwires are achieved by injecting liquid alloy into the microchannel, and allowing the alloy to cool and solidify. The alloy microwires with high melting point can overcome the limitation of working temperature and improve the electrical property. The geometry, the height and diameter of microcoils were flexibly fabricated by the pre-designed laser writing path, the laser power and etching time. The 3D microcoils can provide uniform magnetic field and be widely integrated in many magnetic microsystems.

  15. A Laser Line Auto-Scanning System for Underwater 3D Reconstruction

    PubMed Central

    Chi, Shukai; Xie, Zexiao; Chen, Wenzhu

    2016-01-01

    In this study, a laser line auto-scanning system was designed to perform underwater close-range 3D reconstructions with high accuracy and resolution. The system changes the laser plane direction with a galvanometer to perform automatic scanning and obtain continuous laser strips for underwater 3D reconstruction. The system parameters were calibrated with the homography constraints between the target plane and image plane. A cost function was defined to optimize the galvanometer’s rotating axis equation. Compensation was carried out for the refraction of the incident and emitted light at the interface. The accuracy and the spatial measurement capability of the system were tested and analyzed with standard balls under laboratory underwater conditions, and the 3D surface reconstruction for a sealing cover of an underwater instrument was proved to be satisfactory. PMID:27657074

  16. Fabrication of 2D and 3D photonic structures using laser lithography

    NASA Astrophysics Data System (ADS)

    Gaso, P.; Jandura, D.; Pudis, D.

    2016-12-01

    In this paper we demonstrate possibilities of three-dimensional (3D) printing technology based on two photon polymerization. We used three-dimensional dip-in direct-laser-writing (DLW) optical lithography to fabricate 2D and 3D optical structures for optoelectronics and for optical sensing applications. DLW lithography allows us use a non conventional way how to couple light into the waveguide structure. We prepared ring resonator and we investigated its transmission spectral characteristic. We present 3D inverse opal structure from its design to printing and scanning electron microscope (SEM) imaging. Finally, SEM images of some prepared photonic crystal structures were performed.

  17. 3D printing of weft knitted textile based structures by selective laser sintering of nylon powder

    NASA Astrophysics Data System (ADS)

    Beecroft, M.

    2016-07-01

    3D printing is a form of additive manufacturing whereby the building up of layers of material creates objects. The selective laser sintering process (SLS) uses a laser beam to sinter powdered material to create objects. This paper builds upon previous research into 3D printed textile based material exploring the use of SLS using nylon powder to create flexible weft knitted structures. The results show the potential to print flexible textile based structures that exhibit the properties of traditional knitted textile structures along with the mechanical properties of the material used, whilst describing the challenges regarding fineness of printing resolution. The conclusion highlights the potential future development and application of such pieces.

  18. Use of a white light supercontinuum laser for confocal interference-reflection microscopy

    PubMed Central

    Chiu, L-D; Su, L; Reichelt, S; Amos, WB

    2012-01-01

    Shortly after its development, the white light supercontinuum laser was applied to confocal scanning microscopy as a more versatile substitute for the multiple monochromatic lasers normally used for the excitation of fluorescence. This light source is now available coupled to commercial confocal fluorescence microscopes. We have evaluated a supercontinuum laser as a source for a different purpose: confocal interferometric imaging of living cells and artificial models by interference reflection. We used light in the range 460–700 nm where this source provides a reasonably flat spectrum, and obtained images free from fringe artefacts caused by the longer coherence length of conventional lasers. We have also obtained images of cytoskeletal detail that is difficult to see with a monochromatic laser. PMID:22432542

  19. Use of a white light supercontinuum laser for confocal interference-reflection microscopy.

    PubMed

    Chiu, L-D; Su, L; Reichelt, S; Amos, W B

    2012-05-01

    Shortly after its development, the white light supercontinuum laser was applied to confocal scanning microscopy as a more versatile substitute for the multiple monochromatic lasers normally used for the excitation of fluorescence. This light source is now available coupled to commercial confocal fluorescence microscopes. We have evaluated a supercontinuum laser as a source for a different purpose: confocal interferometric imaging of living cells and artificial models by interference reflection. We used light in the range 460-700 nm where this source provides a reasonably flat spectrum, and obtained images free from fringe artefacts caused by the longer coherence length of conventional lasers. We have also obtained images of cytoskeletal detail that is difficult to see with a monochromatic laser.

  20. Temperature distributions in the laser-heated diamond anvil cell from 3-D numerical modeling

    SciTech Connect

    Rainey, E. S. G.; Kavner, A.; Hernlund, J. W.

    2013-11-28

    We present TempDAC, a 3-D numerical model for calculating the steady-state temperature distribution for continuous wave laser-heated experiments in the diamond anvil cell. TempDAC solves the steady heat conduction equation in three dimensions over the sample chamber, gasket, and diamond anvils and includes material-, temperature-, and direction-dependent thermal conductivity, while allowing for flexible sample geometries, laser beam intensity profile, and laser absorption properties. The model has been validated against an axisymmetric analytic solution for the temperature distribution within a laser-heated sample. Example calculations illustrate the importance of considering heat flow in three dimensions for the laser-heated diamond anvil cell. In particular, we show that a “flat top” input laser beam profile does not lead to a more uniform temperature distribution or flatter temperature gradients than a wide Gaussian laser beam.

  1. 3D transient model to predict temperature and ablated areas during laser processing of metallic surfaces

    NASA Astrophysics Data System (ADS)

    Naghshine, Babak. B.; Kiani, Amirkianoosh

    2017-02-01

    Laser processing is one of the most popular small-scale patterning methods and has many applications in semiconductor device fabrication and biomedical engineering. Numerical modelling of this process can be used for better understanding of the process, optimization, and predicting the quality of the final product. An accurate 3D model is presented here for short laser pulses that can predict the ablation depth and temperature distribution on any section of the material in a minimal amount of time. In this transient model, variations of thermal properties, plasma shielding, and phase change are considered. Ablation depth was measured using a 3D optical profiler. Calculated depths are in good agreement with measured values on laser treated titanium surfaces. The proposed model can be applied to a wide range of materials and laser systems.

  2. LATIS3D: The Gold Standard for Laser-Tissue-Interaction Modeling

    SciTech Connect

    London, R.A.; Makarewicz, A.M.; Kim, B.M.; Gentile, N.A.; Yang, Y.B.; Brlik, M.; Vincent, L.

    2000-02-29

    The goal of this LDRD project has been to create LATIS3D--the world's premier computer program for laser-tissue interaction modeling. The development was based on recent experience with the 2D LATIS code and the ASCI code, KULL. With LATIS3D, important applications in laser medical therapy were researched including dynamical calculations of tissue emulsification and ablation, photothermal therapy, and photon transport for photodynamic therapy. This project also enhanced LLNL's core competency in laser-matter interactions and high-energy-density physics by pushing simulation codes into new parameter regimes and by attracting external expertise. This will benefit both existing LLNL programs such as ICF and SBSS and emerging programs in medical technology and other laser applications.

  3. Multiscale 3D manufacturing: combining thermal extrusion printing with additive and subtractive direct laser writing

    NASA Astrophysics Data System (ADS)

    Malinauskas, Mangirdas; Lukoševičius, Laurynas; MackevičiÅ«tÄ--, DovilÄ--; BalčiÅ«nas, Evaldas; RekštytÄ--, Sima; Paipulas, Domas

    2014-05-01

    A novel approach for efficient manufacturing of three-dimensional (3D) microstructured scaffolds designed for cell studies and tissue engineering applications is presented. A thermal extrusion (fused filament fabrication) 3D printer is employed as a simple and low-cost tabletop device enabling rapid materialization of CAD models out of biocompatible and biodegradable polylactic acid (PLA). Here it was used to produce cm- scale microporous (pore size varying from 100 to 400 µm) scaffolds. The fabricated objects were further laser processed in a direct laser writing (DLW) subtractive (ablation) and additive (lithography) manners. The first approach enables precise surface modification by creating micro-craters, holes and grooves thus increasing the surface roughness. An alternative way is to immerse the 3D PLA scaffold in a monomer solution and use the same DLW setup to refine its inner structure by fabricating dots, lines or a fine mesh on top as well as inside the pores of previously produced scaffolds. The DLW technique is empowered by ultrafast lasers - it allows 3D structuring with high spatial resolution in a great variety of photosensitive materials. Structure geometry on macro- to micro- scales could be finely tuned by combining these two fabrication techniques. Such artificial 3D substrates could be used for cell growth or as biocompatible-biodegradable implants. This combination of distinct material processing techniques enables rapid fabrication of diverse functional micro- featured and integrated devices. Hopefully, the proposed approach will find numerous applications in the field of ms, microfluidics, microoptics and many others.

  4. Thoracic Pedicle Screw Placement Guide Plate Produced by Three-Dimensional (3-D) Laser Printing

    PubMed Central

    Chen, Hongliang; Guo, Kaijing; Yang, Huilin; Wu, Dongying; Yuan, Feng

    2016-01-01

    Background The aim of this study was to evaluate the accuracy and feasibility of an individualized thoracic pedicle screw placement guide plate produced by 3-D laser printing. Material/Methods Thoracic pedicle samples of 3 adult cadavers were randomly assigned for 3-D CT scans. The 3-D thoracic models were established by using medical Mimics software, and a screw path was designed with scanned data. Then the individualized thoracic pedicle screw placement guide plate models, matched to the backside of thoracic vertebral plates, were produced with a 3-D laser printer. Screws were placed with assistance of a guide plate. Then, the placement was assessed. Results With the data provided by CT scans, 27 individualized guide plates were produced by 3-D printing. There was no significant difference in sex and relevant parameters of left and right sides among individuals (P>0.05). Screws were placed with assistance of guide plates, and all screws were in the correct positions without penetration of pedicles, under direct observation and anatomic evaluation post-operatively. Conclusions A thoracic pedicle screw placement guide plate can be produced by 3-D printing. With a high accuracy in placement and convenient operation, it provides a new method for accurate placement of thoracic pedicle screws. PMID:27194139

  5. An overview of avalanche photodiodes and pulsed lasers as they are used in 3D laser radar type applications

    NASA Astrophysics Data System (ADS)

    Dion, Bruno; Bertone, Nick

    2004-08-01

    This paper will examine how Avalanche Photodiodes (APD) and Infrared Pulsed lasers (PL) are used and optimized to provide the "intelligence" to smart weapons. The basics of APD's and PL will be covered and the principle "time of flight ranging" which is the underlining principle of 3D laser radar will be illustrated. The time of flight principle is used for range finding, lidar, 3D laser radar and speed measurements - this information can then be used to provide intelligence to the smart weapon. Examples of such systems are discussed and illustrated, for example: Cluster bombs, Proximity fuses, and how laser range finding systems can be incorporated with GPS to produce effective and lethal weapons. The APD's that are discussed include silicon APD's for cost effective weapons, and 1550nm APDs for eye-safe systems. An overview of the different PL's will be outlined, but the focus will be on 905nm laser pulsars for cost effective laser weapons.

  6. Ship Maintenance Processes with Collaborative Product Lifecycle Management and 3D Terrestrial Laser Scanning Tools: Reducing Costs and Increasing Productivity

    DTIC Science & Technology

    2012-04-30

    approach that incorporates the 3D terrestrial laser scanning (3D TLS) and collaborative product lifecycle management (collab- PLM ) tool suite. Results...incorporated into final implementation of the 3D TLS and collab- PLM tools. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...terrestrial laser scanning (3D TLS) and collaborative product lifecycle management (collab- PLM ) tool suite. Results suggest that when the SHIPMAIN process

  7. Clinical applications of in vivo fluorescence confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Oh, Chilhwan; Park, Sangyong; Kim, Junhyung; Ha, Seunghan; Park, Gyuman; Lee, Gunwoo; Lee, Onseok; Chun, Byungseon; Gweon, Daegab

    2008-02-01

    Living skin for basic and clinical research can be evaluated by Confocal Laser Scanning Microscope (CLSM) non-invasively. CLSM imaging system can achieve skin image its native state either "in vivo" or "fresh biopsy (ex vivo)" without fixation, sectioning and staining that is necessary for routine histology. This study examines the potential fluorescent CLSM with a various exogenous fluorescent contrast agent, to provide with more resolution images in skin. In addition, in vivo fluorescent CLSM researchers will be extended a range of potential clinical application. The prototype of our CLSM system has been developed by Prof. Gweon's group. The operating parameters are composed of some units, such as illuminated wavelength 488 nm, argon illumination power up to 20mW on the skin, objective lens, 0.9NA oil immersion, axial resolution 1.0μm, field of view 200μm x 100μm (lateral resolution , 0.3μm). In human volunteer, fluorescein sodium was administrated topically and intradermally. Animal studies were done in GFP transgenic mouse, IRC mouse and pig skin. For imaging of animal skin, fluorescein sodium, acridine orange, and curcumine were used for fluorescein contrast agent. We also used the GFP transgenic mouse for fluorescein CLSM imaging. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. Curcumin is a yellow food dye that has similar fluorescent properties to fluorescein sodium. Acridin Orange can be highlight nuclei in viable keratinocyte. In vivo CLSM of transgenic GFP mouse enable on in vivo, high resolution view of GFP expressing skin tissue. GFP signals are brightest in corneocyte, kertinocyte, hair and eccrine gland. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. In

  8. Interobserver Agreement of Confocal Laser Endomicroscopy for Bladder Cancer

    PubMed Central

    Chang, Timothy C.; Liu, Jen-Jane; Hsiao, Shelly T.; Pan, Ying; Mach, Kathleen E.; Leppert, John T.; McKenney, Jesse K.; Rouse, Robert V.

    2013-01-01

    Abstract Background and Purpose Emerging optical imaging technologies such as confocal laser endomicroscopy (CLE) hold promise in improving bladder cancer diagnosis. The purpose of this study was to determine the interobserver agreement of image interpretation using CLE for bladder cancer. Methods Experienced CLE urologists (n=2), novice CLE urologists (n=6), pathologists (n=4), and nonclinical researchers (n=5) were recruited to participate in a 2-hour computer-based training consisting of a teaching and validation set of intraoperative white light cystoscopy (WLC) and CLE video sequences from patients undergoing transurethral resection of bladder tumor. Interobserver agreement was determined using the κ statistic. Results Of the 31 bladder regions analyzed, 19 were cancer and 12 were benign. For cancer diagnosis, experienced CLE urologists had substantial agreement for both CLE and WLC+CLE (90%, κ 0.80) compared with moderate agreement for WLC alone (74%, κ 0.46), while novice CLE urologists had moderate agreement for CLE (77%, κ 0.55), WLC (78%, κ 0.54), and WLC+CLE (80%, κ 0.59). Pathologists had substantial agreement for CLE (81%, κ 0.61), and nonclinical researchers had moderate agreement (77%, κ 0.49) in cancer diagnosis. For cancer grading, experienced CLE urologists had fair to moderate agreement for CLE (68%, κ 0.64), WLC (74%, κ 0.67), and WLC+CLE (53%, κ 0.33), as did novice CLE urologists for CLE (53%, κ 0.39), WLC (66%, κ 0.50), and WLC+CLE (61%, κ 0.49). Pathologists (65%, κ 0.55) and nonclinical researchers (61%, κ 0.56) both had moderate agreement for CLE in cancer grading. Conclusions CLE is an adoptable technology for cancer diagnosis in novice CLE observers after a short training with moderate interobserver agreement and diagnostic accuracy similar to WLC alone. Experienced CLE observers may be capable of achieving substantial levels of agreement for cancer diagnosis that is higher than with WLC alone. PMID:23072435

  9. Variation in the measurement of cranial volume and surface area using 3D laser scanning technology.

    PubMed

    Sholts, Sabrina B; Wärmländer, Sebastian K T S; Flores, Louise M; Miller, Kevin W P; Walker, Phillip L

    2010-07-01

    Three-dimensional (3D) laser scanner models of human crania can be used for forensic facial reconstruction, and for obtaining craniometric data useful for estimating age, sex, and population affinity of unidentified human remains. However, the use of computer-generated measurements in a casework setting requires the measurement precision to be known. Here, we assess the repeatability and precision of cranial volume and surface area measurements using 3D laser scanner models created by different operators using different protocols for collecting and processing data. We report intraobserver measurement errors of 0.2% and interobserver errors of 2% of the total area and volume values, suggesting that observer-related errors do not pose major obstacles for sharing, combining, or comparing such measurements. Nevertheless, as no standardized procedure exists for area or volume measurements from 3D models, it is imperative to report the scanning and postscanning protocols employed when such measurements are conducted in a forensic setting.

  10. Model studies of blood flow in basilar artery with 3D laser Doppler anemometer

    NASA Astrophysics Data System (ADS)

    Frolov, S. V.; Sindeev, S. V.; Liepsch, D.; Balasso, A.; Proskurin, S. G.; Potlov, A. Y.

    2015-03-01

    It is proposed an integrated approach to the study of basilar artery blood flow using 3D laser Doppler anemometer for identifying the causes of the formation and development of cerebral aneurysms. Feature of the work is the combined usage of both mathematical modeling and experimental methods. Described the experimental setup and the method of measurement of basilar artery blood flow, carried out in an interdisciplinary laboratory of Hospital Rechts der Isar of Technical University of Munich. The experimental setup used to simulate the blood flow in the basilar artery and to measure blood flow characteristics using 3D laser Doppler anemometer (3D LDA). Described a method of numerical studies carried out in Tambov State Technical University and the Bakoulev Center for Cardiovascular Surgery. Proposed an approach for sharing experimental and numerical methods of research to identify the causes of the basilar artery aneurysms.

  11. Fusion of laser and image sensory data for 3-D modeling of the free navigation space

    NASA Technical Reports Server (NTRS)

    Mass, M.; Moghaddamzadeh, A.; Bourbakis, N.

    1994-01-01

    A fusion technique which combines two different types of sensory data for 3-D modeling of a navigation space is presented. The sensory data is generated by a vision camera and a laser scanner. The problem of different resolutions for these sensory data was solved by reduced image resolution, fusion of different data, and use of a fuzzy image segmentation technique.

  12. Experimental investigation of 3D scanheads for laser micro-processing

    NASA Astrophysics Data System (ADS)

    Penchev, Pavel; Dimov, Stefan; Bhaduri, Debajyoti

    2016-07-01

    The broader use of laser micro-processing technology increases the demand for executing complex machining and joining operations on free-from (3D) workpieces. To satisfy these growing requirements it is necessary to utilise 3D scanheads that integrate beam deflectors (X and Y optical axes) and Z modules with high dynamics. The research presented in this communication proposes an experimental technique to quantify the dynamic capabilities of Z modules, also called Dynamic Focusing Modules (DFM), of such 3D scanheads that are essential for efficient, accurate and repeatable laser micro-processing of free form surfaces. The proposed experimental technique is validated on state-of-art laser micro-machining platform and the results show that the DFM dynamic capabilities are substantially inferior than those of X and Y beam deflectors, in particular the maximum speed of the Z module is less than 10% of the maximum speeds achievable with X and Y optical axes of the scanhead. Thus, the DFM dynamics deficiencies can become a major obstacle for the broader use of high frequency laser sources that necessitate high dynamics 3D scanheads for executing cost effectively free-form surface processing operations.

  13. Sensor Fusion of Cameras and a Laser for City-Scale 3D Reconstruction

    PubMed Central

    Bok, Yunsu; Choi, Dong-Geol; Kweon, In So

    2014-01-01

    This paper presents a sensor fusion system of cameras and a 2D laser sensor for large-scale 3D reconstruction. The proposed system is designed to capture data on a fast-moving ground vehicle. The system consists of six cameras and one 2D laser sensor, and they are synchronized by a hardware trigger. Reconstruction of 3D structures is done by estimating frame-by-frame motion and accumulating vertical laser scans, as in previous works. However, our approach does not assume near 2D motion, but estimates free motion (including absolute scale) in 3D space using both laser data and image features. In order to avoid the degeneration associated with typical three-point algorithms, we present a new algorithm that selects 3D points from two frames captured by multiple cameras. The problem of error accumulation is solved by loop closing, not by GPS. The experimental results show that the estimated path is successfully overlaid on the satellite images, such that the reconstruction result is very accurate. PMID:25375758

  14. Sensor fusion of cameras and a laser for city-scale 3D reconstruction.

    PubMed

    Bok, Yunsu; Choi, Dong-Geol; Kweon, In So

    2014-11-04

    This paper presents a sensor fusion system of cameras and a 2D laser sensorfor large-scale 3D reconstruction. The proposed system is designed to capture data on afast-moving ground vehicle. The system consists of six cameras and one 2D laser sensor,and they are synchronized by a hardware trigger. Reconstruction of 3D structures is doneby estimating frame-by-frame motion and accumulating vertical laser scans, as in previousworks. However, our approach does not assume near 2D motion, but estimates free motion(including absolute scale) in 3D space using both laser data and image features. In orderto avoid the degeneration associated with typical three-point algorithms, we present a newalgorithm that selects 3D points from two frames captured by multiple cameras. The problemof error accumulation is solved by loop closing, not by GPS. The experimental resultsshow that the estimated path is successfully overlaid on the satellite images, such that thereconstruction result is very accurate.

  15. A Marked Poisson Process Driven Latent Shape Model for 3D Segmentation of Reflectance Confocal Microscopy Image Stacks of Human Skin.

    PubMed

    Ghanta, Sindhu; Jordan, Michael I; Kose, Kivanc; Brooks, Dana H; Rajadhyaksha, Milind; Dy, Jennifer G

    2016-10-05

    Segmenting objects of interest from 3D datasets is a common problem encountered in biological data. Small field of view and intrinsic biological variability combined with optically subtle changes of intensity, resolution and low contrast in images make the task of segmentation difficult, especially for microscopy of unstained living or freshly excised thick tissues. Incorporating shape information in addition to the appearance of the object of interest can often help improve segmentation performance. However, shapes of objects in tissue can be highly variable and design of a flexible shape model that encompasses these variations is challenging. To address such complex segmentation problems, we propose a unified probabilistic framework that can incorporate the uncertainty associated with complex shapes, variable appearance and unknown locations. The driving application which inspired the development of this framework is a biologically important segmentation problem: the task of automatically detecting and segmenting the dermal-epidermal junction (DEJ) in 3D reflectance confocal microscopy (RCM) images of human skin. RCM imaging allows noninvasive observation of cellular, nuclear and morphological detail. The DEJ is an important morphological feature as it is where disorder, disease and cancer usually start. Detecting the DEJ is challenging because it is a 2D surface in a 3D volume which has strong but highly variable number of irregularly spaced and variably shaped "peaks and valleys". In addition, RCM imaging resolution, contrast and intensity vary with depth. Thus a prior model needs to incorporate the intrinsic structure while allowing variability in essentially all its parameters. We propose a model which can incorporate objects of interest with complex shapes and variable appearance in an unsupervised setting by utilizing domain knowledge to build appropriate priors of the model. Our novel strategy to model this structure combines a spatial Poisson process with

  16. A Marked Poisson Process Driven Latent Shape Model for 3D Segmentation of Reflectance Confocal Microscopy Image Stacks of Human Skin.

    PubMed

    Ghanta, Sindhu; Jordan, Michael I; Kose, Kivanc; Brooks, Dana H; Rajadhyaksha, Milind; Dy, Jennifer G

    2017-01-01

    Segmenting objects of interest from 3D data sets is a common problem encountered in biological data. Small field of view and intrinsic biological variability combined with optically subtle changes of intensity, resolution, and low contrast in images make the task of segmentation difficult, especially for microscopy of unstained living or freshly excised thick tissues. Incorporating shape information in addition to the appearance of the object of interest can often help improve segmentation performance. However, the shapes of objects in tissue can be highly variable and design of a flexible shape model that encompasses these variations is challenging. To address such complex segmentation problems, we propose a unified probabilistic framework that can incorporate the uncertainty associated with complex shapes, variable appearance, and unknown locations. The driving application that inspired the development of this framework is a biologically important segmentation problem: the task of automatically detecting and segmenting the dermal-epidermal junction (DEJ) in 3D reflectance confocal microscopy (RCM) images of human skin. RCM imaging allows noninvasive observation of cellular, nuclear, and morphological detail. The DEJ is an important morphological feature as it is where disorder, disease, and cancer usually start. Detecting the DEJ is challenging, because it is a 2D surface in a 3D volume which has strong but highly variable number of irregularly spaced and variably shaped "peaks and valleys." In addition, RCM imaging resolution, contrast, and intensity vary with depth. Thus, a prior model needs to incorporate the intrinsic structure while allowing variability in essentially all its parameters. We propose a model which can incorporate objects of interest with complex shapes and variable appearance in an unsupervised setting by utilizing domain knowledge to build appropriate priors of the model. Our novel strategy to model this structure combines a spatial Poisson

  17. Fusion of Terrestrial and Airborne Laser Data for 3D modeling Applications

    NASA Astrophysics Data System (ADS)

    Mohammed, Hani Mahmoud

    This thesis deals with the 3D modeling phase of the as-built large BIM projects. Among several means of BIM data capturing, such as photogrammetric or range tools, laser scanners have been one of the most efficient and practical tool for a long time. They can generate point clouds with high resolution for 3D models that meet nowadays' market demands. The current 3D modeling projects of as-built BIMs are mainly focused on using one type of laser scanner data, such as Airborne or Terrestrial. According to the literatures, no significant (few) efforts were made towards the fusion of heterogeneous laser scanner data despite its importance. The importance of the fusion of heterogeneous data arises from the fact that no single type of laser data can provide all the information about BIM, especially for large BIM projects that are existing on a large area, such as university buildings, or Heritage places. Terrestrial laser scanners are able to map facades of buildings and other terrestrial objects. However, they lack the ability to map roofs or higher parts in the BIM project. Airborne laser scanner on the other hand, can map roofs of the buildings efficiently and can map only small part of the facades. Short range laser scanners can map the interiors of the BIM projects, while long range scanners are used for mapping wide exterior areas in BIM projects. In this thesis the long range laser scanner data obtained in the Stop-and-Go mapping mode, the short range laser scanner data, obtained in a fully static mapping mode, and the airborne laser data are all fused together to bring a complete effective solution for a large BIM project. Working towards the 3D modeling of BIM projects, the thesis framework starts with the registration of the data, where a new fast automatic registration algorithm were developed. The next step is to recognize the different objects in the BIM project (classification), and obtain 3D models for the buildings. The last step is the development of an

  18. Inscription of 3D waveguides in diamond using an ultrafast laser

    NASA Astrophysics Data System (ADS)

    Courvoisier, Arnaud; Booth, Martin J.; Salter, Patrick S.

    2016-07-01

    Three dimensional waveguides within the bulk of diamond are manufactured using ultrafast laser fabrication. High intensities within the focal volume of the laser cause breakdown of the diamond into a graphitic phase leading to a stress induced refractive index change in neighboring regions. Type II waveguiding is thus enabled between two adjacent graphitic tracks, but supporting just a single polarization state. We show that adaptive aberration correction during the laser processing allows the controlled fabrication of more complex structures beneath the surface of the diamond which can be used for 3D waveguide splitters and Type III waveguides which support both polarizations.

  19. Reliability of a 3D surface laser scanner for orthodontic applications.

    PubMed

    Kusnoto, Budi; Evans, Carla A

    2002-10-01

    A device for recreating three-dimensional (3D) objects on a computer is the surface laser scanner. By triangulating distances between the reflecting laser beam and the scanned surface, the surface laser scanner can detect not only an object's length and width but also its depth. The scanner's ease of use has opened various possibilities in laboratory research and clinical investigation. We assessed the reliability of generating 3D object reconstructions using the Minolta Vivid700 3D surface laser scanner (Minolta USA, Ramsey, NJ). Accuracy and reproducibility were tested on a geometrical calibrated cylinder, a dental study model, and a plaster facial model. Tests were conducted at varying distances between the object and the scanner. It was found that (1) in the calibrated cylinder tests, spatial distance measurement was accurate to 0.5 mm (+/- 0.1 mm) in the vertical dimension and 0.3 mm (+/- 0.3 mm) in the horizontal dimension; (2) in the study model test, molar width was accurate to 0.2 mm (+/- 0.1 mm, P >.05), and palatal vault depth could be measured to 0.7 mm (+/- 0.2 mm, P > 0.05); and (3) for the facial model, an accuracy of 1.9 +/- 0.8 mm was obtained. The findings suggest that the surface laser scanner has great research potential because of its accuracy and ease of use. Treatment changes, growth, surgical simulations, and many other orthodontic applications can be approached 3-dimensionally with this device.

  20. An efficient solid modeling system based on a hand-held 3D laser scan device

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Xu, Jun; Xu, Chenxi; Pan, Ming

    2014-12-01

    The hand-held 3D laser scanner sold in the market is appealing for its port and convenient to use, but price is expensive. To develop such a system based cheap devices using the same principles as the commercial systems is impossible. In this paper, a simple hand-held 3D laser scanner is developed based on a volume reconstruction method using cheap devices. Unlike convenient laser scanner to collect point cloud of an object surface, the proposed method only scan few key profile curves on the surface. Planar section curve network can be generated from these profile curves to construct a volume model of the object. The details of design are presented, and illustrated by the example of a complex shaped object.

  1. Rapid 3D video/laser sensing and digital archiving with immediate on-scene feedback for 3D crime scene/mass disaster data collection and reconstruction

    NASA Astrophysics Data System (ADS)

    Altschuler, Bruce R.; Oliver, William R.; Altschuler, Martin D.

    1996-02-01

    We describe a system for rapid and convenient video data acquisition and 3-D numerical coordinate data calculation able to provide precise 3-D topographical maps and 3-D archival data sufficient to reconstruct a 3-D virtual reality display of a crime scene or mass disaster area. Under a joint U.S. army/U.S. Air Force project with collateral U.S. Navy support, to create a 3-D surgical robotic inspection device -- a mobile, multi-sensor robotic surgical assistant to aid the surgeon in diagnosis, continual surveillance of patient condition, and robotic surgical telemedicine of combat casualties -- the technology is being perfected for remote, non-destructive, quantitative 3-D mapping of objects of varied sizes. This technology is being advanced with hyper-speed parallel video technology and compact, very fast laser electro-optics, such that the acquisition of 3-D surface map data will shortly be acquired within the time frame of conventional 2-D video. With simple field-capable calibration, and mobile or portable platforms, the crime scene investigator could set up and survey the entire crime scene, or portions of it at high resolution, with almost the simplicity and speed of video or still photography. The survey apparatus would record relative position, location, and instantly archive thousands of artifacts at the site with 3-D data points capable of creating unbiased virtual reality reconstructions, or actual physical replicas, for the investigators, prosecutors, and jury.

  2. Laser excited confocal microscope fluorescence scanner and method

    DOEpatents

    Mathies, Richard A.; Peck, Konan

    1992-01-01

    A fluorescent scanner for scanning the fluorescence from a fluorescence labeled separated sample on a sample carrier including a confocal microscope for illuminating a predetermined volume of the sample carrier and/or receiving and processing fluorescence emissions from said volume to provide a display of the separated sample.

  3. Laser excited confocal microscope fluorescence scanner and method

    DOEpatents

    Mathies, R.A.; Peck, K.

    1992-02-25

    A fluorescent scanner is designed for scanning the fluorescence from a fluorescence labeled separated sample on a sample carrier. The scanner includes a confocal microscope for illuminating a predetermined volume of the sample carrier and/or receiving and processing fluorescence emissions from the volume to provide a display of the separated sample. 8 figs.

  4. Improving Resolution of Confocal Laser Induced Fluorescence in Argon Helicon Plasma

    NASA Astrophysics Data System (ADS)

    Soderholm, Mark; Vandervort, Robert; Scime, Earl; McKee, John; McCarren, Dustin

    2014-10-01

    Laser Induced Fluorescence (LIF) provides measurements of flow speed, temperature and when absolutely calibrated, density of ions or neutrals in a plasma. Traditionally, laser induced fluorescence requires two ports on a plasma device. One port is used for laser injection and the other is used for fluorescence emission collection. Traditional LIF is tedious and time consuming to align. These difficulties motivate the development of an optical configuration that requires a single port and remains fully aligned at all times; confocal LIF. Our confocal optical design employs a single two inch diameter lens to both inject the laser light and collect the stimulated emission from an argon plasma. A dichroic mirror is used to separate the injected laser light from the collected emission. The measurement location is scanned radially by manually adjusting the final focusing lens position. In the initial version of the confocal optical system, measurements were poorly resolved radially because they were integrated over a fairly large path length (~4 cm) centered at the focal point. Here we present collected data from a modified configuration that significantly improves the special resolution of confocal measurements. The confocal measurements are compared to traditional, two-port, LIF measurements over the same radial range.

  5. The 3D scanner prototype utilize object profile imaging using line laser and octave software

    NASA Astrophysics Data System (ADS)

    Nurdini, Mugi; Manunggal, Trikarsa Tirtadwipa; Samsi, Agus

    2016-11-01

    Three-dimensional scanner or 3D Scanner is a device to reconstruct the real object into digital form on a computer. 3D Scanner is a technology that is being developed, especially in developed countries, where the current 3D Scanner devices is the advanced version with a very expensive prices. This study is basically a simple prototype of 3D Scanner with a very low investment costs. 3D Scanner prototype device consists of a webcam, a rotating desk system controlled by a stepper motor and Arduino UNO, and a line laser. Objects that limit the research is the object with same radius from its center point (object pivot). Scanning is performed by using object profile imaging by line laser which is then captured by the camera and processed by a computer (image processing) using Octave software. On each image acquisition, the scanned object on a rotating desk rotated by a certain degree, so for one full turn multiple images of a number of existing side are finally obtained. Then, the profile of the entire images is extracted in order to obtain digital object dimension. Digital dimension is calibrated by length standard, called gage block. Overall dimensions are then digitally reconstructed into a three-dimensional object. Validation of the scanned object reconstruction of the original object dimensions expressed as a percentage error. Based on the results of data validation, horizontal dimension error is about 5% to 23% and vertical dimension error is about +/- 3%.

  6. Femtosecond laser 3D nanofabrication in glass: enabling direct write of integrated micro/nanofluidic chips

    NASA Astrophysics Data System (ADS)

    Cheng, Ya; Liao, Yang; Sugioka, Koji

    2014-03-01

    The creation of complex three-dimensional (3D) fluidic systems composed of hollow micro- and nanostructures embedded in transparent substrates has attracted significant attention from both scientific and applied research communities. However, it is by now still a formidable challenge to build 3D micro- and nanofluidic structures with arbitrary configurations using conventional planar lithographic fabrication methods. As a direct and maskless fabrication technique, femtosecond laser micromachining provides a straightforward approach for high-precision spatial-selective modification inside transparent materials through nonlinear optical absorption. Here, we demonstrate rapid fabrication of high-aspect-ratio micro- and/or nanofluidic structures with various 3D configurations in glass substrates by femtosecond laser direct writing. Based on this approach, we demonstrate several functional micro- and nanofluidic devices including a 3D passive microfluidic mixer, a capillary electrophoresis (CE) analysis chip, and an integrated micro-nanofluidic system for single DNA analysis. This technology offers new opportunities to develop novel 3D micro-nanofluidic systems for a variety of lab-on-a-chip applications.

  7. Femtosecond fiber laser additive manufacturing and welding for 3D manufacturing

    NASA Astrophysics Data System (ADS)

    Huang, Huan; Nie, Bai; Wan, Peng; Yang, Lih-Mei; Bai, Shuang; Liu, Jian

    2015-03-01

    Due to the unique ultra-short pulse duration and high peak power, femtosecond (fs) laser has emerged as a powerful tool for many applications but has rarely been studied for 3D printing. In this paper, welding of both bulk and powder materials is demonstrated for the first time by using high energy and high repetition rate fs fiber lasers. It opens up new scenarios and opportunities for 3D printing with the following advantages - greater range of materials especially with high melting temperature, greater-than-ever level of precision (sub-micron) and less heat-affected-zone (HAZ). Mechanical properties (strength and hardness) and micro-structures (grain size) of the fabricated parts are investigated. For dissimilar materials bulk welding, good welding quality with over 210 MPa tensile strength is obtained. Also full melting of the micron-sized refractory powders with high melting temperature (above 3000 degree C) is achieved for the first time. 3D parts with shapes like ring and cube are fabricated. Not only does this study explore the feasibility of melting dissimilar and high melting temperature materials using fs lasers, but it also lays out a solid foundation for 3D printing of complex structure with designed compositions, microstructures and properties. This can greatly benefit the applications in automobile, aerospace and biomedical industries, by producing parts like nozzles, engines and miniaturized biomedical devices.

  8. A Survey Study of the Blast Furnace at Kuangshan Village Using 3D Laser Scanning

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Huang, Xing; Qian, Wei

    2017-01-01

    The blast furnace from the Northern Song Dynasty at Kuangshan Village is the tallest blast furnace that remains from ancient China. Previous studies have assumed that the furnace had a closed mouth. In this paper, a three-dimensional (3D) model of the blast furnace is constructed using 3D laser scanning technology, and accurate profile data are obtained using software. It is shown that the furnace throat is smaller than had been previously thought and that the furnace mouth is of the open type. This new furnace profile constitutes a discovery in the history of iron-smelting technology.

  9. Relativistic Laser Pulse Intensification with 3D Printed Micro-Tube Plasma Target

    NASA Astrophysics Data System (ADS)

    Ji, Liangliang; Snyder, Joseph; Pukhov, Alexander; Akli, Kramer

    2015-11-01

    The potential and applications of laser-plasma interactions (LPI) are restricted by the parameter space of existing lasers and targets. Advancing the laser intensity to the extreme regime is motivated by the production of energetic particle beams and by the quest to explore the exotic regimes of light-matter interaction. Target density and dimensions can always be varied to optimize the outcome. Here, we propose to create another degree of freedom in the parameter space of LPI using recent advances in 3D printing of materials. Fine structures at nm scale with high repetition and accuracy can nowadays be manufactured, allowing for a full precise control of the target. We demonstrate, via particle-in-cell (PIC) simulations, that 3D-printed micro-tube plasma (MTP) targets yield an intensity enhancement factor of 2-5. The novel MTP targets not only act as a plasma optical device to reach the 1023W/cm2 threshold based on today's intensities, but can also boost the generation of secondary particle and radiation sources. This work demonstrates that the combination of high contrast high power lasers and nano-3D printing techniques opens new paths in the intensity frontier and LPI micro-engineering.

  10. Post-processing of 3D-printed parts using femtosecond and picosecond laser radiation

    NASA Astrophysics Data System (ADS)

    Mingareev, Ilya; Gehlich, Nils; Bonhoff, Tobias; Meiners, Wilhelm; Kelbassa, Ingomar; Biermann, Tim; Richardson, Martin C.

    2014-03-01

    Additive manufacturing, also known as 3D-printing, is a near-net shape manufacturing approach, delivering part geometry that can be considerably affected by various process conditions, heat-induced distortions, solidified melt droplets, partially fused powders, and surface modifications induced by the manufacturing tool motion and processing strategy. High-repetition rate femtosecond and picosecond laser radiation was utilized to improve surface quality of metal parts manufactured by laser additive techniques. Different laser scanning approaches were utilized to increase the ablation efficiency and to reduce the surface roughness while preserving the initial part geometry. We studied post-processing of 3D-shaped parts made of Nickel- and Titanium-base alloys by utilizing Selective Laser Melting (SLM) and Laser Metal Deposition (LMD) as additive manufacturing techniques. Process parameters such as the pulse energy, the number of layers and their spatial separation were varied. Surface processing in several layers was necessary to remove the excessive material, such as individual powder particles, and to reduce the average surface roughness from asdeposited 22-45 μm to a few microns. Due to the ultrafast laser-processing regime and the small heat-affected zone induced in materials, this novel integrated manufacturing approach can be used to post-process parts made of thermally and mechanically sensitive materials, and to attain complex designed shapes with micrometer precision.

  11. Three-dimensional volume reconstruction of extracellular matrix proteins in uveal melanoma from fluorescent confocal laser scanning microscope images

    PubMed Central

    BAJCSY, P.; LEE, S-C.; LIN, A.; FOLBERG, R.

    2006-01-01

    Summary The distribution of looping patterns of laminin in uveal melanomas and other tumours has been associated with adverse outcome. Moreover, these patterns are generated by highly invasive tumour cells through the process of vasculogenic mimicry and are not therefore blood vessels. Nevertheless, these extravascular matrix patterns conduct plasma. The three-dimensional (3D) configuration of these laminin-rich patterns compared with blood vessels has been the subject of speculation and intensive investigation. We have developed a method for the 3D reconstruction of volume for these extravascular matrix proteins from serial paraffin sections cut at 4 μm thicknesses and stained with a fluorescently labelled antibody to laminin (Maniotis et al., 2002). Each section was examined via confocal laser-scanning focal microscopy (CLSM) and 13 images were recorded in the Z-dimension for each slide. The input CLSM imagery is composed of a set of 3D subvolumes (stacks of 2D images) acquired at multiple confocal depths, from a sequence of consecutive slides. Steps for automated reconstruction included (1) unsupervised methods for selecting an image frame from a subvolume based on entropy and contrast criteria, (2) a fully automated registration technique for image alignment and (3) an improved histogram equalization method that compensates for spatially varying image intensities in CLSM imagery due to photo-bleaching. We compared image alignment accuracy of a fully automated method with registration accuracy achieved by human subjects using a manual method. Automated 3D volume reconstruction was found to provide significant improvement in accuracy, consistency of results and performance time for CLSM images acquired from serial paraffin sections. PMID:16438687

  12. Design and development of multi functional confocal laser scanning microscope with UV / VIS laser source

    NASA Astrophysics Data System (ADS)

    Kanai, Yoshikazu; Kanzaki, Yousuke; Wakaki, Moriaki; Takeyama, Norihide

    2005-08-01

    A high resolution Confocal Laser Scanning Microscope (CLSM) with UV / VIS light sources was developed as the first step of multi-functional microscope. The optical system is designed to optimize for both UV and VIS wavelengths. An UV laser is used to achieve higher resolution, and a VIS is for multi functions. A new objective lens specialized for this application was designed and fabricated. Specification of the lens and the optical system is NA:0.95, EFL:2.5mm, WD:1.5mm, Resolution:160nm and achromatic for two wavelengths of UV 325.0nm / VIS 632.8nm. Several specimens were characterized to check the performance of the system. Some optical materials under study were measured for evaluation, and interesting results could be obtained. Multi-functional measurements are being planed as a next step. This system will help the research of nano-structures, photonic-crystals and biology.

  13. Laser jetting of femto-liter metal droplets for high resolution 3D printed structures

    PubMed Central

    Zenou, M.; Sa’ar, A.; Kotler, Z.

    2015-01-01

    Laser induced forward transfer (LIFT) is employed in a special, high accuracy jetting regime, by adequately matching the sub-nanosecond pulse duration to the metal donor layer thickness. Under such conditions, an effective solid nozzle is formed, providing stability and directionality to the femto-liter droplets which are printed from a large gap in excess of 400 μm. We illustrate the wide applicability of this method by printing several 3D metal objects. First, very high aspect ratio (A/R > 20), micron scale, copper pillars in various configuration, upright and arbitrarily bent, then a micron scale 3D object composed of gold and copper. Such a digital printing method could serve the generation of complex, multi-material, micron-scale, 3D materials and novel structures. PMID:26602432

  14. A 3D Polymer Based Printed Two-Dimensional Laser Scanner

    NASA Astrophysics Data System (ADS)

    Oyman, H. A.; Gokdel, Y. D.; Ferhanoglu, O.; Yalcinkaya, A. D.

    2016-10-01

    A two-dimensional (2D) polymer based scanning mirror with magnetic actuation is developed for imaging applications. Proposed device consists of a circular suspension holding a rectangular mirror and can generate a 2D scan pattern. Three dimensional (3D) printing technology which is used for implementation of the device, offers added flexibility in controlling the cross-sectional profile as well as the stress distribution compared to the traditional planar process technologies. The mirror device is developed to meet a portable, miniaturized confocal microscope application in mind, delivering 4.5 and 4.8 degrees of optical scan angles at 111 and 267 Hz, respectively. As a result of this mechanical performance, the resulting microscope incorporating the mirror is estimated to accomplish a field of view (FOV) of 350 µm × 350 µm.

  15. Angle extended linear MEMS scanning system for 3D laser vision sensor

    NASA Astrophysics Data System (ADS)

    Pang, Yajun; Zhang, Yinxin; Yang, Huaidong; Zhu, Pan; Gai, Ye; Zhao, Jian; Huang, Zhanhua

    2016-09-01

    Scanning system is often considered as the most important part for 3D laser vision sensor. In this paper, we propose a method for the optical system design of angle extended linear MEMS scanning system, which has features of huge scanning degree, small beam divergence angle and small spot size for 3D laser vision sensor. The principle of design and theoretical formulas are derived strictly. With the help of software ZEMAX, a linear scanning optical system based on MEMS has been designed. Results show that the designed system can extend scanning angle from ±8° to ±26.5° with a divergence angle small than 3.5 mr, and the spot size is reduced for 4.545 times.

  16. Monitoring UVR induced damage in single cells and isolated nuclei using SR-FTIR microspectroscopy and 3D confocal Raman imaging.

    PubMed

    Lipiec, Ewelina; Bambery, Keith R; Heraud, Philip; Kwiatek, Wojciech M; McNaughton, Don; Tobin, Mark J; Vogel, Christian; Wood, Bayden R

    2014-09-07

    SR-FTIR in combination with Principal Component Analysis (PCA) was applied to investigate macromolecular changes in a population of melanocytes and their extracted nuclei induced by environmentally relevant fluxes of UVR (Ultraviolet Radiation). Living cells and isolated cellular nuclei were investigated post-irradiation for three different irradiation dosages (130, 1505, 15,052 Jm(-2) UVR, weighted) after either 24 or 48 hours of incubation. DNA conformational changes were observed in cells exposed to an artificial UVR solar-simulator source as evidenced by a shift in the DNA asymmetric phosphodiester vibration from 1236 cm(-1) to 1242 cm(-1) in the case of the exposed cells and from 1225 cm(-1) to 1242 cm(-1) for irradiated nuclei. PCA Scores plots revealed distinct clustering of spectra from irradiated cells and nuclei from non-irradiated controls in response to the range of applied UVR radiation doses. 3D Raman confocal imaging in combination with k-means cluster analysis was applied to study the effect of the UVR radiation exposure on cellular nuclei. Chemical changes associated with apoptosis were detected and included intra-nuclear lipid deposition along with chromatin condensation. The results reported here demonstrate the utility of SR-FTIR and Raman spectroscopy to probe in situ DNA damage in cell nuclei resulting from UVR exposure. These results are in agreement with the increasing body of evidence that lipid accumulation is a characteristic of aggressive cancer cells, and are involved in the production of membranes for rapid cell proliferation.

  17. 3D printing of gas jet nozzles for laser-plasma accelerators

    NASA Astrophysics Data System (ADS)

    Döpp, A.; Guillaume, E.; Thaury, C.; Gautier, J.; Ta Phuoc, K.; Malka, V.

    2016-07-01

    Recent results on laser wakefield acceleration in tailored plasma channels have underlined the importance of controlling the density profile of the gas target. In particular, it was reported that the appropriate density tailoring can result in improved injection, acceleration, and collimation of laser-accelerated electron beams. To achieve such profiles, innovative target designs are required. For this purpose, we have reviewed the usage of additive layer manufacturing, commonly known as 3D printing, in order to produce gas jet nozzles. Notably we have compared the performance of two industry standard techniques, namely, selective laser sintering (SLS) and stereolithography (SLA). Furthermore we have used the common fused deposition modeling to reproduce basic gas jet designs and used SLA and SLS for more sophisticated nozzle designs. The nozzles are characterized interferometrically and used for electron acceleration experiments with the Salle Jaune terawatt laser at Laboratoire d'Optique Appliquée.

  18. Combining laser scan and photogrammetry for 3D object modeling using a single digital camera

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Zhang, Hong; Zhang, Xiangwei

    2009-07-01

    In the fields of industrial design, artistic design and heritage conservation, physical objects are usually digitalized by reverse engineering through some 3D scanning methods. Laser scan and photogrammetry are two main methods to be used. For laser scan, a video camera and a laser source are necessary, and for photogrammetry, a digital still camera with high resolution pixels is indispensable. In some 3D modeling tasks, two methods are often integrated to get satisfactory results. Although many research works have been done on how to combine the results of the two methods, no work has been reported to design an integrated device at low cost. In this paper, a new 3D scan system combining laser scan and photogrammetry using a single consumer digital camera is proposed. Nowadays there are many consumer digital cameras, such as Canon EOS 5D Mark II, they usually have features of more than 10M pixels still photo recording and full 1080p HD movie recording, so a integrated scan system can be designed using such a camera. A square plate glued with coded marks is used to place the 3d objects, and two straight wood rulers also glued with coded marks can be laid on the plate freely. In the photogrammetry module, the coded marks on the plate make up a world coordinate and can be used as control network to calibrate the camera, and the planes of two rulers can also be determined. The feature points of the object and the rough volume representation from the silhouettes can be obtained in this module. In the laser scan module, a hand-held line laser is used to scan the object, and the two straight rulers are used as reference planes to determine the position of the laser. The laser scan results in dense points cloud which can be aligned together automatically through calibrated camera parameters. The final complete digital model is obtained through a new a patchwise energy functional method by fusion of the feature points, rough volume and the dense points cloud. The design

  19. 3-D aluminum nanostructure with microhole array synthesized by femtosecond laser radiation for enhanced light extinction.

    PubMed

    Mahmood, Abdul Salam; Venkatakrishnan, Krishnan; Tan, Bo

    2013-11-14

    This article presents 3-D aluminum micro-nanostructures for enhanced light absorption. Periodic microhole arrays were created by firing a train of femtosecond laser pulses at megahertz pulse frequency onto the surface of an aluminum target at ambient conditions. The laser trains ablated the target surface and created microholes leading to the generation of deposited nanostructures inside and around the microholes. These micro-nanostructures showed enhanced light absorption, which is attributed to surface plasmonics induced by the generation of both nano- and microstructures. These micro-nanostructures may be promising for solar cell applications.

  20. 3-D aluminum nanostructure with microhole array synthesized by femtosecond laser radiation for enhanced light extinction

    NASA Astrophysics Data System (ADS)

    Mahmood, Abdul Salam; Venkatakrishnan, Krishnan; Tan, Bo

    2013-11-01

    This article presents 3-D aluminum micro-nanostructures for enhanced light absorption. Periodic microhole arrays were created by firing a train of femtosecond laser pulses at megahertz pulse frequency onto the surface of an aluminum target at ambient conditions. The laser trains ablated the target surface and created microholes leading to the generation of deposited nanostructures inside and around the microholes. These micro-nanostructures showed enhanced light absorption, which is attributed to surface plasmonics induced by the generation of both nano- and microstructures. These micro-nanostructures may be promising for solar cell applications.

  1. 3-D aluminum nanostructure with microhole array synthesized by femtosecond laser radiation for enhanced light extinction

    PubMed Central

    2013-01-01

    This article presents 3-D aluminum micro-nanostructures for enhanced light absorption. Periodic microhole arrays were created by firing a train of femtosecond laser pulses at megahertz pulse frequency onto the surface of an aluminum target at ambient conditions. The laser trains ablated the target surface and created microholes leading to the generation of deposited nanostructures inside and around the microholes. These micro-nanostructures showed enhanced light absorption, which is attributed to surface plasmonics induced by the generation of both nano- and microstructures. These micro-nanostructures may be promising for solar cell applications. PMID:24225364

  2. Printing Functional 3D Microdevices by Laser-Induced Forward Transfer.

    PubMed

    Luo, Jun; Pohl, Ralph; Qi, Lehua; Römer, Gert-Willem; Sun, Chao; Lohse, Detlef; Visser, Claas Willem

    2017-03-01

    Slender, out-of-plane metal microdevices are made in a new spatial domain, by using laser-induced forward transfer (LIFT) of metals. Here, a thermocouple with a thickness of 10 µm and a height of 250 µm, consisting of platinum and gold pillars is demonstrated. Multimaterial LIFT enables manufacturing in the micrometer to millimeter range, i.e., between lithography and other 3D printing technologies.

  3. Mobile large scale 3D coordinate measuring system based on network of rotating laser automatic theodolites

    NASA Astrophysics Data System (ADS)

    Liu, Zhigang; Liu, Zhongzheng; Wu, Jianwei; Xu, Yaozhong

    2010-08-01

    This paper presents a mobile 3D coordinate measuring system for large scale metrology. This system is composed of a network of rotating laser automatic theodolites (N-RLATs) and a portable touch probe. In the N-RLAT system, each RLAT consists of two laser fans which rotate about its own Z axis at a constant speed and scan the whole metrology space. The optical sensors mounted on the portable touch probe receive the sweeping laser fans and generate the corresponding pulse signals, which establish a relationship between rotating angle of laser fan and time, and then the space angle measurement is converted into the corresponding peak time precision measurement of pulse signal. The rotating laser fans are modeled mathematically as a time varying parametrical vector in its local framework. A two steps on-site calibration method for solving the parameters of each RLAT and coordinate transformation among the N-RLATs. The portable probe is composed of optical sensors array with specified geometrical features and a touch point, on which the coordinates of optical sensors is determined by the N-RLATs and the touch point is estimated by solving a non-linear system. A prototype mobile 3D coordinate measuring system is developed and experiment results show its validity.

  4. Femtosecond pulsed light polarization induced effects in direct laser writing 3D nanolithography

    NASA Astrophysics Data System (ADS)

    Malinauskas, Mangirdas; RekštytÄ--, Sima; Jonavičius, Tomas; Gailevičius, Darius; Mizeikis, Vygantas; Gamaly, Eugene; Juodkazis, Saulius

    2016-03-01

    We demonstrate how the coupling between (i) polarization of the writing laser beam, (ii) tight focusing and (iii) heat conduction affects the size, shape and absorption in the laser-affected area and therefore the polymerization process. It is possible to control the sizes of 3D laser-produced structure at the scale of several nanometers. Specifically we were able to tune the aspect ratio of 3D suspended line up to 20% in hybrid SZ2080 resist. The focal spot of tightly focused linearly polarized beam has an elliptical form with the long axis in the field direction. It is shown here that this effect is enhanced by increase in the electronic heat conduction when polarization coincide with temperature gradient along with the absorption. Overlapping of three effects (i- iii) results in the difference of several tens of nanometers between two axes of the focal ellipse. Narrow line appears when polarization and scan direction coincide, while the wide line is produced when these directions are perpendicular to each other. The effect scales with the laser intensity giving a possibility to control the width of the structure on nanometer scale as demonstrated experimentally in this work. These effects are of general nature and can be observed in any laser-matter interaction experiments where plasma produced by using tight focusing of linear-polarized light.

  5. Laser-assisted direct manufacturing of functionally graded 3D objects

    NASA Astrophysics Data System (ADS)

    Iakovlev, A.; Trunova, E.; Grevey, Dominique; Smurov, Igor

    2003-09-01

    Coaxial powder injection into a laser beam was applied for the laser-assisted direct manufacturing of 3D functionally graded (FG) objects. The powders of Stainless Steel 316L and Stellite grade 12 were applied. The following laser sources were used: (1) quasi-cw CO2 Rofin Sinar laser with 120 μm focal spot diameter and (2) pulsed-periodic Nd:YAG (HAAS HL 304P) with 200 μm focal spot diameter. The objects were fabricated layer-by-layer in the form of "walls", having the thickness of about 200 μm for CO2 laser and 300 μm for Nd:YAG laser. SEM analysis was applied for the FG objects fabricated by CO2 laser, yielding wall elements distribution in vertical direction. It was found that microhardness distribution is fully correlated with the components distribution. The compositional gradient can be smooth or sharp. Periodic multi-layered structures can be obtained as well. Minimal thickness of a layer with the fixed composition (for cw CO2 laser) is about 50 μm. Minimal thickness of a graded material zone, i.e. zone with composition variation from pure stainless steel to pure stellite is about 30 μm.

  6. 3-D Laser-Based Multiclass and Multiview Object Detection in Cluttered Indoor Scenes.

    PubMed

    Zhang, Xuesong; Zhuang, Yan; Hu, Huosheng; Wang, Wei

    2017-01-01

    This paper investigates the problem of multiclass and multiview 3-D object detection for service robots operating in a cluttered indoor environment. A novel 3-D object detection system using laser point clouds is proposed to deal with cluttered indoor scenes with a fewer and imbalanced training data. Raw 3-D point clouds are first transformed to 2-D bearing angle images to reduce the computational cost, and then jointly trained multiple object detectors are deployed to perform the multiclass and multiview 3-D object detection. The reclassification technique is utilized on each detected low confidence bounding box in the system to reduce false alarms in the detection. The RUS-SMOTEboost algorithm is used to train a group of independent binary classifiers with imbalanced training data. Dense histograms of oriented gradients and local binary pattern features are combined as a feature set for the reclassification task. Based on the dalian university of technology (DUT)-3-D data set taken from various office and household environments, experimental results show the validity and good performance of the proposed method.

  7. 3D indoor modeling using a hand-held embedded system with multiple laser range scanners

    NASA Astrophysics Data System (ADS)

    Hu, Shaoxing; Wang, Duhu; Xu, Shike

    2016-10-01

    Accurate three-dimensional perception is a key technology for many engineering applications, including mobile mapping, obstacle detection and virtual reality. In this article, we present a hand-held embedded system designed for constructing 3D representation of structured indoor environments. Different from traditional vehicle-borne mobile mapping methods, the system presented here is capable of efficiently acquiring 3D data while an operator carrying the device traverses through the site. It consists of a simultaneous localization and mapping(SLAM) module, a 3D attitude estimate module and a point cloud processing module. The SLAM is based on a scan matching approach using a modern LIDAR system, and the 3D attitude estimate is generated by a navigation filter using inertial sensors. The hardware comprises three 2D time-flight laser range finders and an inertial measurement unit(IMU). All the sensors are rigidly mounted on a body frame. The algorithms are developed on the frame of robot operating system(ROS). The 3D model is constructed using the point cloud library(PCL). Multiple datasets have shown robust performance of the presented system in indoor scenarios.

  8. Estimation of line dimensions in 3D direct laser writing lithography

    NASA Astrophysics Data System (ADS)

    Guney, M. G.; Fedder, G. K.

    2016-10-01

    Two photon polymerization (TPP) based 3D direct laser writing (3D-DLW) finds application in a wide range of research areas ranging from photonic and mechanical metamaterials to micro-devices. Most common structures are either single lines or formed by a set of interconnected lines as in the case of crystals. In order to increase the fidelity of these structures and reach the ultimate resolution, the laser power and scan speed used in the writing process should be chosen carefully. However, the optimization of these writing parameters is an iterative and time consuming process in the absence of a model for the estimation of line dimensions. To this end, we report a semi-empirical analytic model through simulations and fitting, and demonstrate that it can be used for estimating the line dimensions mostly within one standard deviation of the average values over a wide range of laser power and scan speed combinations. The model delimits the trend in onset of micro-explosions in the photoresist due to over-exposure and of low degree of conversion due to under-exposure. The model guides setting of high-fidelity and robust writing parameters of a photonic crystal structure without iteration and in close agreement with the estimated line dimensions. The proposed methodology is generalizable by adapting the model coefficients to any 3D-DLW setup and corresponding photoresist as a means to estimate the line dimensions for tuning the writing parameters.

  9. 3D laser scanning and modelling of the Dhow heritage for the Qatar National Museum

    NASA Astrophysics Data System (ADS)

    Wetherelt, A.; Cooper, J. P.; Zazzaro, C.

    2014-08-01

    Curating boats can be difficult. They are complex structures, often demanding to conserve whether in or out of the water; they are usually large, difficult to move on land, and demanding of gallery space. Communicating life on board to a visiting public in the terra firma context of a museum can be difficult. Boats in their native environment are inherently dynamic artifacts. In a museum they can be static and divorced from the maritime context that might inspire engagement. New technologies offer new approaches to these problems. 3D laser scanning and digital modeling offers museums a multifaceted means of recording, monitoring, studying and communicating watercraft in their care. In this paper we describe the application of 3D laser scanning and subsequent digital modeling. Laser scans were further developed using computer-generated imagery (CGI) modeling techniques to produce photorealistic 3D digital models for development into interactive, media-based museum displays. The scans were also used to generate 2D naval lines and orthographic drawings as a lasting curatorial record of the dhows held by the National Museum of Qatar.

  10. Analysis of uncertainty and repeatability of a low-cost 3D laser scanner.

    PubMed

    Polo, María-Eugenia; Felicísimo, Angel M

    2012-01-01

    Portable 3D laser scanners are a valuable tool for compiling elaborate digital collections of archaeological objects and analysing the shapes and dimensions of pieces. Although low-cost desktop 3D laser scanners have powerful capacities, it is important to know their limitations. This paper performs an analysis of the uncertainty and repeatability of the NextEngine™ portable low-cost 3D laser scanner by scanning an object 20 times in two different resolution modes-Macro and Wide. Some dimensions of the object were measured using a digital calliper, and these results were used as the "true" or control data. In comparing the true and the scanned data, we verified that the mean uncertainty in the Macro Mode is approximately half that of the Wide Mode, at ± 0.81 mm and ± 1.66 mm, respectively. These experimental results are significantly higher than the accuracy specifications provided by the manufacturer. An analysis of repeatability shows that the successive replicates do not match in the same position. The results are better in Macro Mode than in Wide Mode; it is observed that the repeatability factor is slightly larger than the corresponding mode accuracy, with ± 0.84 vs. ± 0.81 mm in Macro Mode and ± 1.82 vs. ± 1.66 mm in Wide Mode. We suggest several improvements, such as adding an external reference scale or providing a calibrated object to allow for a self-calibration operation of the scanner.

  11. Integrated approach to laser delivery and confocal signal detection.

    PubMed

    Ismail, Nur; Akca, Bakiye Imran; Sun, Fei; Wörhoff, Kerstin; de Ridder, René M; Pollnau, Markus; Driessen, Alfred

    2010-08-15

    We present an on-chip arrayed waveguide grating (AWG) sensor based on the confocal arrangement of two AWGs, one acting as focusing illuminator and one as signal collector. The chip can be close to, or in direct contact with, a sample, e.g., biological tissue, without the need of external optics. The collection efficiency of our device can be more than 1 order of magnitude higher than that of a standard AWG, in which light is collected by one input channel. Experimental results on the collection efficiency and volume are presented, together with a demonstration of multiwavelength imaging.

  12. Laser processes and analytics for high power 3D battery materials

    NASA Astrophysics Data System (ADS)

    Pfleging, W.; Zheng, Y.; Mangang, M.; Bruns, M.; Smyrek, P.

    2016-03-01

    Laser processes for cutting, modification and structuring of energy storage materials such as electrodes, separator materials and current collectors have a great potential in order to minimize the fabrication costs and to increase the performance and operational lifetime of high power lithium-ion-batteries applicable for stand-alone electric energy storage devices and electric vehicles. Laser direct patterning of battery materials enable a rather new technical approach in order to adjust 3D surface architectures and porosity of composite electrode materials such as LiCoO2, LiMn2O4, LiFePO4, Li(NiMnCo)O2, and Silicon. The architecture design, the increase of active surface area, and the porosity of electrodes or separator layers can be controlled by laser processes and it was shown that a huge impact on electrolyte wetting, lithium-ion diffusion kinetics, cell life-time and cycling stability can be achieved. In general, the ultrafast laser processing can be used for precise surface texturing of battery materials. Nevertheless, regarding cost-efficient production also nanosecond laser material processing can be successfully applied for selected types of energy storage materials. A new concept for an advanced battery manufacturing including laser materials processing is presented. For developing an optimized 3D architecture for high power composite thick film electrodes electrochemical analytics and post mortem analytics using laser-induced breakdown spectroscopy were performed. Based on mapping of lithium in composite electrodes, an analytical approach for studying chemical degradation in structured and unstructured lithium-ion batteries will be presented.

  13. Adaptive laser beam forming for laser shock micro-forming for 3D MEMS devices fabrication

    NASA Astrophysics Data System (ADS)

    Zou, Ran; Wang, Shuliang; Wang, Mohan; Li, Shuo; Huang, Sheng; Lin, Yankun; Chen, Kevin P.

    2016-07-01

    Laser shock micro-forming is a non-thermal laser forming method that use laser-induced shockwave to modify surface properties and to adjust shapes and geometry of work pieces. In this paper, we present an adaptive optical technique to engineer spatial profiles of the laser beam to exert precision control on the laser shock forming process for free-standing MEMS structures. Using a spatial light modulator, on-target laser energy profiles are engineered to control shape, size, and deformation magnitude, which has led to significant improvement of the laser shock processing outcome at micrometer scales. The results presented in this paper show that the adaptive-optics laser beam forming is an effective method to improve both quality and throughput of the laser forming process at micrometer scales.

  14. Precision-guided surgical navigation system using laser guidance and 3D autostereoscopic image overlay.

    PubMed

    Liao, Hongen; Ishihara, Hirotaka; Tran, Huy Hoang; Masamune, Ken; Sakuma, Ichiro; Dohi, Takeyoshi

    2010-01-01

    This paper describes a precision-guided surgical navigation system for minimally invasive surgery. The system combines a laser guidance technique with a three-dimensional (3D) autostereoscopic image overlay technique. Images of surgical anatomic structures superimposed onto the patient are created by employing an animated imaging method called integral videography (IV), which can display geometrically accurate 3D autostereoscopic images and reproduce motion parallax without the need for special viewing or tracking devices. To improve the placement accuracy of surgical instruments, we integrated an image overlay system with a laser guidance system for alignment of the surgical instrument and better visualization of patient's internal structure. We fabricated a laser guidance device and mounted it on an IV image overlay device. Experimental evaluations showed that the system could guide a linear surgical instrument toward a target with an average error of 2.48 mm and standard deviation of 1.76 mm. Further improvement to the design of the laser guidance device and the patient-image registration procedure of the IV image overlay will make this system practical; its use would increase surgical accuracy and reduce invasiveness.

  15. Confocal laser spectroscopy of glasses modified by ultrashort laser pulses for waveguide fabrication

    NASA Astrophysics Data System (ADS)

    Chan, James Wai-Jeung

    2002-08-01

    The work described in this thesis involves the fabrication of waveguiding structures inside glasses using femtosecond (fs) laser pulses and the study of the different atomic scale changes associated with refractive index modification that occur in the fs laser modified glasses. This study helps elucidate the possible processes that occur during fs laser writing of waveguides in glasses. Waveguide writing inside fused silica and phosphate glass using focused fs laser pulses has been demonstrated. The modification induced inside both glasses is determined to be different. Inside fused silica, the modification involves a single high index region while inside the phosphate glass (IOG-1, Schott Glass Technologies, Inc.), the modification results in a central, low index, non-guiding region bordered by two, high index, waveguiding regions. The waveguides inside both glasses have an index change on the order of 10 -4. Color center defects have been identified in modified glasses using confocal fluorescence spectroscopy. Modified fused silica exhibits a fluorescence band at 630 nm and at 540 nm, which are attributed to the non-bridging oxygen hole center (NBOHC) and oxygen vacancy defects created by the fs pulses. A fluorescence band at 600 nm is observed in modified phosphate glass, which is assigned to the phosphorus oxygen hole center (POHC) defect. A quantitative analysis of the photobleaching of these defects with exposure to 488 nm light is conducted. Fluorescence imaging of the modified materials is performed to elucidate the location of these defects within the exposed regions in the glass. Using confocal Raman spectroscopy, atomic scale structural changes in the glass network of modified fused silica are reported and correlated to the changes in the physical properties of the material. The changes in the Raman spectrum of modified fused silica, specifically increases in the 490 cm-1 and 605 cm-1 peaks, indicate that fs pulses induce densification in fused silica

  16. MAMMALIAN APOPTOSIS IN WHOLE NEONATAL OVARIES USING CONFOCAL LASER SCANNING MICROSCOPY

    EPA Science Inventory

    MAMMALIAN APOPTOSIS IN WHOLE NEONATAL OVARIES USING CONFOCAL LASER SCANNING MICROSCOPY

    Robert M. Zucker Susan C. Jeffery and Sally D. Perreault

    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Prot...

  17. Confocal laser scanning microscopy of apoptosis in organogenesis-stage mouse embryos

    EPA Science Inventory

    Confocal laser scanning microscopy combined with a vital stain has been used to study apoptosis in organogenesis-stage mouse embryos. In order to achieve optical sectioning through embryos, it was necessary to use low power objectives and to prepare the sample appropriately. Mous...

  18. Long-range laser scanning and 3D imaging for the Gneiss quarries survey

    NASA Astrophysics Data System (ADS)

    Schenker, Filippo Luca; Spataro, Alessio; Pozzoni, Maurizio; Ambrosi, Christian; Cannata, Massimiliano; Günther, Felix; Corboud, Federico

    2016-04-01

    In Canton Ticino (Southern Switzerland), the exploitation of natural stone, mostly gneisses, is an important activity of valley's economies. Nowadays, these economic activities are menaced by (i) the exploitation costs related to geological phenomena such as fractures, faults and heterogeneous rocks that hinder the processing of the stone product, (ii) continuously changing demand because of the evolving natural stone fashion and (iii) increasing administrative limits and rules acting to protect the environment. Therefore, the sustainable development of the sector for the next decades needs new and effective strategies to regulate and plan the quarries. A fundamental step in this process is the building of a 3D geological model of the quarries to constrain the volume of commercial natural stone and the volume of waste. In this context, we conducted Terrestrial Laser Scanning surveys of the quarries in the Maggia Valley to obtain a detailed 3D topography onto which the geological units were mapped. The topographic 3D model was obtained with a long-range laser scanning Riegl VZ4000 that can measure from up to 4 km of distance with a speed of 147,000 points per second. It operates with the new V-line technology, which defines the surface relief by sensing differentiated signals (echoes), even in the presence of obstacles such as vegetation. Depending on the esthetics of the gneisses, we defined seven types of natural stones that, together with faults and joints, were mapped onto the 3D models of the exploitation sites. According to the orientation of the geological limits and structures, we projected the different rock units and fractures into the excavation front. This way, we obtained a 3D geological model from which we can quantitatively estimate the volume of the seven different natural stones (with different commercial value) and waste (with low commercial value). To verify the 3D geological models and to quantify exploited rock and waste volumes the same

  19. 3rd Tech DeltaSphere-3000 Laser 3D Scene Digitizer infrared laser scanner hazard analysis.

    SciTech Connect

    Augustoni, Arnold L.

    2005-02-01

    A laser hazard analysis and safety assessment was performed for the 3rd Tech model DeltaSphere-3000{reg_sign} Laser 3D Scene Digitizer, infrared laser scanner model based on the 2000 version of the American National Standard Institute's Standard Z136.1, for the Safe Use of Lasers. The portable scanner system is used in the Robotic Manufacturing Science and Engineering Laboratory (RMSEL). This scanning system had been proposed to be a demonstrator for a new application. The manufacture lists the Nominal Ocular Hazard Distance (NOHD) as less than 2 meters. It was necessary that SNL validate this NOHD prior to its use as a demonstrator involving the general public. A formal laser hazard analysis is presented for the typical mode of operation for the current configuration as well as a possible modified mode and alternative configuration.

  20. Topographical surveys: Classical method versus 3D laser scanning. Case study - An application in civil engineering

    NASA Astrophysics Data System (ADS)

    Grigoraş, I.-R.; Covăsnianu, A.; Pleşu, G.; Benedict, B.

    2009-04-01

    The paper describes an experiment which took place in Iasi town, Romania, consisted in two different topographical survey techniques applied for one and the same objective placed in a block within the city (western part) - a thermal power station. The purpose was to compare those methods and to determine which one is proper to be used in this domain in terms of fastness, optimization and speed of data processing. First technique applied for our survey was the classical one, with a total station. Using the CAD technique, we obtained a final product (a dwg file) and a list of coordinates (a text file). The second method, which we focused our attention more, was the measurement with a very precise 3D laser scanstation, also very suitable in archeology. The data obtained were processed with special software. Result was a 3D model of the thermal power plant composed of measurable cloud point data. Finally, analyzing the advantages and disadvantages of each method, we came to the conclusion that the 3D laser scanning which we used matches well the application, in this case civil engineering, but the future of accepting and implementing this technique is in the hands of Romanian authorities.

  1. Geoarchaeological site documentation and analysis of 3D data derived by terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Hoffmeister, D.; Zellmann, S.; Kindermann, K.; Pastoors, A.; Lang, U.; Bubenzer, O.; Weniger, G.-C.; Bareth, G.

    2014-05-01

    Terrestrial laser scanning was conducted to document and analyse sites of geoarchaeological interest in Jordan, Egypt and Spain. In those cases, the terrestrial laser scanner LMS-Z420i from Riegl was used in combination with an accurate RTK-GPS for georeferencing of the point clouds. Additionally, local surveying networks were integrated by established transformations and used for indirect registration purposes. All data were integrated in a workflow that involves different software and according results. The derived data were used for the documentation of the sites by accurate plans and cross-sections. Furthermore, the 3D data were analysed for geoarchaeological research problems, such as volumetric determinations, the ceiling thickness of a cave and lighting simulations based on path tracing. The method was reliable in harsh environmental conditions, but the weight of the instrument, the measuring time and the minimum measurement distance were a drawback. However, generally an accurate documentation of the sites was possible. Overall, the integration in a 3D GIS is easily possible by the accurate georeference of the derived data. In addition, local survey results are also implemented by the established transformations. Enhanced analyses based on the derived 3D data shows promising results.

  2. Reconstruction of 3D tree stem models from low-cost terrestrial laser scanner data

    NASA Astrophysics Data System (ADS)

    Kelbe, Dave; Romanczyk, Paul; van Aardt, Jan; Cawse-Nicholson, Kerry

    2013-05-01

    With the development of increasingly advanced airborne sensing systems, there is a growing need to support sensor system design, modeling, and product-algorithm development with explicit 3D structural ground truth commensurate to the scale of acquisition. Terrestrial laser scanning is one such technique which could provide this structural information. Commercial instrumentation to suit this purpose has existed for some time now, but cost can be a prohibitive barrier for some applications. As such we recently developed a unique laser scanning system from readily-available components, supporting low cost, highly portable, and rapid measurement of below-canopy 3D forest structure. Tools were developed to automatically reconstruct tree stem models as an initial step towards virtual forest scene generation. The objective of this paper is to assess the potential of this hardware/algorithm suite to reconstruct 3D stem information for a single scan of a New England hardwood forest site. Detailed tree stem structure (e.g., taper, sweep, and lean) is recovered for trees of varying diameter, species, and range from the sensor. Absolute stem diameter retrieval accuracy is 12.5%, with a 4.5% overestimation bias likely due to the LiDAR beam divergence.

  3. Laser 3-D measuring system and real-time visual feedback for teaching and correcting breathing.

    PubMed

    Povšič, Klemen; Fležar, Matjaž; Možina, Janez; Jezeršek, Matija

    2012-03-01

    We present a novel method for real-time 3-D body-shape measurement during breathing based on the laser multiple-line triangulation principle. The laser projector illuminates the measured surface with a pattern of 33 equally inclined light planes. Simultaneously, the camera records the distorted light pattern from a different viewpoint. The acquired images are transferred to a personal computer, where the 3-D surface reconstruction, shape analysis, and display are performed in real time. The measured surface displacements are displayed with a color palette, which enables visual feedback to the patient while breathing is being taught. The measuring range is approximately 400×600×500 mm in width, height, and depth, respectively, and the accuracy of the calibrated apparatus is ±0.7 mm. The system was evaluated by means of its capability to distinguish between different breathing patterns. The accuracy of the measured volumes of chest-wall deformation during breathing was verified using standard methods of volume measurements. The results show that the presented 3-D measuring system with visual feedback has great potential as a diagnostic and training assistance tool when monitoring and evaluating the breathing pattern, because it offers a simple and effective method of graphical communication with the patient.

  4. Grammar-based Automatic 3D Model Reconstruction from Terrestrial Laser Scanning Data

    NASA Astrophysics Data System (ADS)

    Yu, Q.; Helmholz, P.; Belton, D.; West, G.

    2014-04-01

    The automatic reconstruction of 3D buildings has been an important research topic during the last years. In this paper, a novel method is proposed to automatically reconstruct the 3D building models from segmented data based on pre-defined formal grammar and rules. Such segmented data can be extracted e.g. from terrestrial or mobile laser scanning devices. Two steps are considered in detail. The first step is to transform the segmented data into 3D shapes, for instance using the DXF (Drawing Exchange Format) format which is a CAD data file format used for data interchange between AutoCAD and other program. Second, we develop a formal grammar to describe the building model structure and integrate the pre-defined grammars into the reconstruction process. Depending on the different segmented data, the selected grammar and rules are applied to drive the reconstruction process in an automatic manner. Compared with other existing approaches, our proposed method allows the model reconstruction directly from 3D shapes and takes the whole building into account.

  5. Triangular mesh establishment of 3D laser scanning data based on ellipsoidal projection

    NASA Astrophysics Data System (ADS)

    Zheng, De-hua; Xu, Jia; Li, Jia; Wang, Xin-sen

    2011-10-01

    The establishment of high quality triangular mesh is one of the key steps in 3D laser scanning data processing. Traditional triangulation algorithms have been proposed directly on the basis of adjacency relation between points in 3D space. However, when the point density is non-uniform or the noise exists, the problems such as surface hole, dough sheet overlapping and inconsistent normal appear easily. In this paper, a triangular mesh establishing algorithm based on ellipsoidal projection is proposed. After comparing the theory of ellipsoidal projection and cylindrical projection, the proposed triangular mesh establishing algorithm is analyzed in detail including basic idea and implementation method. To evaluate the performance and efficiency of the proposed algorithm, two experiments are then carried out on the 3D point cloud data of a foundation pit. The results indicate that though the computational efficiency of proposed algorithm is a little inferior to the algorithm based on cylindrical projection, the proposed algorithm is more effective for establishing point cloud of both top and bottom of the object and the original topological relation of 3D scanning points can be maintained better.

  6. Easy performance of 6-color confocal immunofluorescence with 4-laser line microscopes.

    PubMed

    Eissing, Nathalie; Heger, Lukas; Baranska, Anna; Cesnjevar, Robert; Büttner-Herold, Maike; Söder, Stephan; Hartmann, Arndt; Heidkamp, Gordon F; Dudziak, Diana

    2014-09-01

    Confocal laser scanning microscopy is an advanced technique for imaging tissue samples in vitro and in vivo at high optical resolution. The development of new fluorochrome variants do not only make it possible to perform multicolor flow cytometry of single cells, but in combination with high resolution laser scanning systems also to investigate the distribution of cells in lymphoid tissues by confocal immunofluorescence analyses, thus allowing the distinction of various cell populations directly in the tissue. Here, we provide a protocol for the visualization of at least six differently fluorochrome-labeled antibodies at the same time using a conventional confocal laser scanning microscope with four laser lines (405 nm, 488 nm, 555 nm, and 639 nm laser wavelength) in both murine and human tissue samples. We further demonstrate that compensation correction algorithms are not necessary to reduce spillover of fluorochromes into other channels when the used fluorochromes are combined according to their specific emission bands and the varying Stokes shift for co-excited fluorochromes with the same laser line.

  7. Local intracellular ion measurements with luminescent indicators using confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Opitz, N.; Merten, E.; Acker, H.

    1995-09-01

    Ion sensitive fluoroprobes such as BCECF (pH) and FURA-II (Ca2+) are frequently used indicators for determination of ion activities in single cells and subcellular compartments, e.g. by video enhanced or video intensified microscopy. Moreover, using confocal laser scanning microscopy (CLSM) with its inherent potential for noninvasive optical sectioning of cells and tissues and subsequent 3D image reconstruction, intracellular ion topographies can be monitored via pseudocolor encoded ratio imaging from pixel to pixel enabling in vivo measurements of dynamic intracellular processes. Regardless of the degree of spatial resolution, reliable qualtitative determinations essentially depend on accurate calibration of the intracellularly entrapped fluoroprobe. Calibration is either established on the basis of a whole cell or within a more or less extended subcellular compartment and the characteristics are displayed as concentration encoded pseudocolor bar within the image frame. This calibration is assumed to be valid for other cellular compartments and, in case of ion imaging, it is even thought to be valid for every single pixel of the complete pixel field. However, the assumption of a topographically invariant intracellular calibration requires a reliable behavior of the intracellularly applied indicator. This intracellular integrity of the dyes often does not seem to exist since intracellular calibration curves considerably deviate from in vitro calibration characteristics. Deviations may be due to intracellular interactions of indicator molecules with cytoplasmic macromolecules, e.g. proteins, resulting in spectral distortions and/or sensitivity deficits as demonstrated by the indicators BCECF and FURA-RED (a FURA-II analogue) or to intracellular redistribution of the indicator as exemplified by pH measurements using carboxy-SNARF-1. Consequences of these investigations as well as further potential interferences are discussed with special respect to ion imaging

  8. Laser scanning confocal microscopy characterization of water repellent distribution in a sandstone pore network.

    PubMed

    Zoghlami, Karima; Gómez-Gras, David; Corbella, Mercè; Darragi, Fadila

    2008-11-01

    In the present work, we propose the use of the Laser Scanning Confocal Microscopy (LSCM) to determine the effect of water repellents on rock's pore-network configuration and interconnection. The rocks studied are sandstones of Miocene age, a building material that is commonly found in the architectural heritage of Tunisia. The porosity quantitative data of treated and untreated samples, obtained by mercury porosimetry tests, were compared. The results show a slight decrease in total porosity with the water repellent treatment, which reduced both microporosity and macroporosity. This reduction produced a modification in pore size distribution and a shift of the pore access size mode interval toward smaller pore diameters (from the 30-40 microm to the 20-30 microm intervals). The water repellent was observed in SEM images as a continuous film coating grain surfaces; moreover, it was easily visualized in LSCM, by staining the water repellent with Epodye fluorochrome, and the coating thickness was straightforwardly measured (1.5-2 microm). In fact, the combination of mercury intrusion porosimetry data and LSCM observations suggests that the porosity reduction and the shift of the pore diameter mode were mainly due to the general reduction of pore diameters, but also to the plugging of the smallest pores (less than 3-4 microm in diameter) by the water repellent film. Finally, the LSCM technique enabled the reconstruction of 3D views of the water repellent coating film in the pore network, indicating that its distribution was uniform and continuous over the 100 microm thick sample. The LSCM imaging facilitates the integration and interpretation of mercury porosimetry and SEM data.

  9. 3D real-time measurement system of seam with laser

    NASA Astrophysics Data System (ADS)

    Huang, Min-shuang; Huang, Jun-fen

    2014-02-01

    3-D Real-time Measurement System of seam outline based on Moiré Projection is proposed and designed. The system is composed of LD, grating, CCD, video A/D, FPGA, DSP and an output interface. The principle and hardware makeup of high-speed and real-time image processing circuit based on a Digital Signal Processor (DSP) and a Field Programmable Gate Array (FPGA) are introduced. Noise generation mechanism in poor welding field conditions is analyzed when Moiré stripes are projected on a welding workpiece surface. Median filter is adopted to smooth the acquired original laser image of seam, and then measurement results of a 3-D outline image of weld groove are provided.

  10. Creating stable Floquet-Weyl semimetals by laser-driving of 3D Dirac materials.

    PubMed

    Hübener, Hannes; Sentef, Michael A; De Giovannini, Umberto; Kemper, Alexander F; Rubio, Angel

    2017-01-17

    Tuning and stabilizing topological states, such as Weyl semimetals, Dirac semimetals or topological insulators, is emerging as one of the major topics in materials science. Periodic driving of many-body systems offers a platform to design Floquet states of matter with tunable electronic properties on ultrafast timescales. Here we show by first principles calculations how femtosecond laser pulses with circularly polarized light can be used to switch between Weyl semimetal, Dirac semimetal and topological insulator states in a prototypical three-dimensional (3D) Dirac material, Na3Bi. Our findings are general and apply to any 3D Dirac semimetal. We discuss the concept of time-dependent bands and steering of Floquet-Weyl points and demonstrate how light can enhance topological protection against lattice perturbations. This work has potential practical implications for the ultrafast switching of materials properties, such as optical band gaps or anomalous magnetoresistance.

  11. 3D Micropatterned Surface Inspired by Salvinia molesta via Direct Laser Lithography

    PubMed Central

    2015-01-01

    Biomimetic functional surfaces are attracting increasing attention for their relevant technological applications. Despite these efforts, inherent limitations of microfabrication techniques prevent the replication of complex hierarchical microstructures. Using a 3D laser lithography technique, we fabricated a 3D patterned surface bioinspired to Salvinia molesta leaves. The artificial hairs, with crownlike heads, were reproduced by scaling down (ca. 100 times smaller) the dimensions of natural features, so that microscale hairs with submicrometric resolution were attained. The micropatterned surface, in analogy with the natural model, shows interesting properties in terms of hydrophobicity and air retention when submerged by water, even if realized with a hydrophilic material. Furthermore, we successfully demonstrated the capability to promote localized condensation of water droplets from moisture in the atmosphere. PMID:26558410

  12. Creating stable Floquet-Weyl semimetals by laser-driving of 3D Dirac materials

    NASA Astrophysics Data System (ADS)

    Hübener, Hannes; Sentef, Michael A.; de Giovannini, Umberto; Kemper, Alexander F.; Rubio, Angel

    2017-01-01

    Tuning and stabilizing topological states, such as Weyl semimetals, Dirac semimetals or topological insulators, is emerging as one of the major topics in materials science. Periodic driving of many-body systems offers a platform to design Floquet states of matter with tunable electronic properties on ultrafast timescales. Here we show by first principles calculations how femtosecond laser pulses with circularly polarized light can be used to switch between Weyl semimetal, Dirac semimetal and topological insulator states in a prototypical three-dimensional (3D) Dirac material, Na3Bi. Our findings are general and apply to any 3D Dirac semimetal. We discuss the concept of time-dependent bands and steering of Floquet-Weyl points and demonstrate how light can enhance topological protection against lattice perturbations. This work has potential practical implications for the ultrafast switching of materials properties, such as optical band gaps or anomalous magnetoresistance.

  13. 3D Micropatterned Surface Inspired by Salvinia molesta via Direct Laser Lithography.

    PubMed

    Tricinci, Omar; Terencio, Tercio; Mazzolai, Barbara; Pugno, Nicola M; Greco, Francesco; Mattoli, Virgilio

    2015-11-25

    Biomimetic functional surfaces are attracting increasing attention for their relevant technological applications. Despite these efforts, inherent limitations of microfabrication techniques prevent the replication of complex hierarchical microstructures. Using a 3D laser lithography technique, we fabricated a 3D patterned surface bioinspired to Salvinia molesta leaves. The artificial hairs, with crownlike heads, were reproduced by scaling down (ca. 100 times smaller) the dimensions of natural features, so that microscale hairs with submicrometric resolution were attained. The micropatterned surface, in analogy with the natural model, shows interesting properties in terms of hydrophobicity and air retention when submerged by water, even if realized with a hydrophilic material. Furthermore, we successfully demonstrated the capability to promote localized condensation of water droplets from moisture in the atmosphere.

  14. 3D Imaging of Nanoparticle Distribution in Biological Tissue by Laser-Induced Breakdown Spectroscopy

    NASA Astrophysics Data System (ADS)

    Gimenez, Y.; Busser, B.; Trichard, F.; Kulesza, A.; Laurent, J. M.; Zaun, V.; Lux, F.; Benoit, J. M.; Panczer, G.; Dugourd, P.; Tillement, O.; Pelascini, F.; Sancey, L.; Motto-Ros, V.

    2016-07-01

    Nanomaterials represent a rapidly expanding area of research with huge potential for future medical applications. Nanotechnology indeed promises to revolutionize diagnostics, drug delivery, gene therapy, and many other areas of research. For any biological investigation involving nanomaterials, it is crucial to study the behavior of such nano-objects within tissues to evaluate both their efficacy and their toxicity. Here, we provide the first account of 3D label-free nanoparticle imaging at the entire-organ scale. The technology used is known as laser-induced breakdown spectroscopy (LIBS) and possesses several advantages such as speed of operation, ease of use and full compatibility with optical microscopy. We then used two different but complementary approaches to achieve 3D elemental imaging with LIBS: a volume reconstruction of a sliced organ and in-depth analysis. This proof-of-concept study demonstrates the quantitative imaging of both endogenous and exogenous elements within entire organs and paves the way for innumerable applications.

  15. Laser irradiated fluorescent perfluorocarbon microparticles in 2-D and 3-D breast cancer cell models

    NASA Astrophysics Data System (ADS)

    Niu, Chengcheng; Wang, Long; Wang, Zhigang; Xu, Yan; Hu, Yihe; Peng, Qinghai

    2017-03-01

    Perfluorocarbon (PFC) droplets were studied as new generation ultrasound contrast agents via acoustic or optical droplet vaporization (ADV or ODV). Little is known about the ODV irradiated vaporization mechanisms of PFC-microparticle complexs and the stability of the new bubbles produced. In this study, fluorescent perfluorohexane (PFH) poly(lactic-co-glycolic acid) (PLGA) particles were used as a model to study the process of particle vaporization and bubble stability following excitation in two-dimensional (2-D) and three-dimensional (3-D) cell models. We observed localization of the fluorescent agent on the microparticle coating material initially and after vaporization under fluorescence microscopy. Furthermore, the stability and growth dynamics of the newly created bubbles were observed for 11 min following vaporization. The particles were co-cultured with 2-D cells to form 3-D spheroids and could be vaporized even when encapsulated within the spheroids via laser irradiation, which provides an effective basis for further work.

  16. Creating stable Floquet–Weyl semimetals by laser-driving of 3D Dirac materials

    PubMed Central

    Hübener, Hannes; Sentef, Michael A.; De Giovannini, Umberto; Kemper, Alexander F.; Rubio, Angel

    2017-01-01

    Tuning and stabilizing topological states, such as Weyl semimetals, Dirac semimetals or topological insulators, is emerging as one of the major topics in materials science. Periodic driving of many-body systems offers a platform to design Floquet states of matter with tunable electronic properties on ultrafast timescales. Here we show by first principles calculations how femtosecond laser pulses with circularly polarized light can be used to switch between Weyl semimetal, Dirac semimetal and topological insulator states in a prototypical three-dimensional (3D) Dirac material, Na3Bi. Our findings are general and apply to any 3D Dirac semimetal. We discuss the concept of time-dependent bands and steering of Floquet–Weyl points and demonstrate how light can enhance topological protection against lattice perturbations. This work has potential practical implications for the ultrafast switching of materials properties, such as optical band gaps or anomalous magnetoresistance. PMID:28094286

  17. Robust Locally Weighted Regression For Ground Surface Extraction In Mobile Laser Scanning 3D Data

    NASA Astrophysics Data System (ADS)

    Nurunnabi, A.; West, G.; Belton, D.

    2013-10-01

    A new robust way for ground surface extraction from mobile laser scanning 3D point cloud data is proposed in this paper. Fitting polynomials along 2D/3D points is one of the well-known methods for filtering ground points, but it is evident that unorganized point clouds consist of multiple complex structures by nature so it is not suitable for fitting a parametric global model. The aim of this research is to develop and implement an algorithm to classify ground and non-ground points based on statistically robust locally weighted regression which fits a regression surface (line in 2D) by fitting without any predefined global functional relation among the variables of interest. Afterwards, the z (elevation)-values are robustly down weighted based on the residuals for the fitted points. The new set of down weighted z-values along with x (or y) values are used to get a new fit of the (lower) surface (line). The process of fitting and down-weighting continues until the difference between two consecutive fits is insignificant. Then the final fit represents the ground level of the given point cloud and the ground surface points can be extracted. The performance of the new method has been demonstrated through vehicle based mobile laser scanning 3D point cloud data from urban areas which include different problematic objects such as short walls, large buildings, electric poles, sign posts and cars. The method has potential in areas like building/construction footprint determination, 3D city modelling, corridor mapping and asset management.

  18. Effects of scanning orientation on outlier formation in 3D laser scanning of reflective surfaces

    NASA Astrophysics Data System (ADS)

    Wang, Yutao; Feng, Hsi-Yung

    2016-06-01

    Inspecting objects with reflective surfaces using 3D laser scanning is a demanded but challenging part inspection task due to undesirable specular reflections, which produce extensive outliers in the scanned point cloud. These outliers need to be removed in order to alleviate subsequent data processing issues. Many existing automatic outlier removal methods do not detect outliers according to the outlier formation properties. As a result, these methods only offer limited capabilities in removing extensive and complex outliers from scanning objects with reflective surfaces. This paper reports an empirical study which experimentally investigates the outlier formation characteristics in relation to the scanning orientation of the laser probe. The objective is to characterize the scanning orientation effects on outlier formation in order to facilitate the development of an effective outlier detection and removal method. Such an experimental investigation was hardly done before. It has been found in this work that scanning orientation can directly affect outlier extensity and occurrence in 3D laser scanning. A general guidance on proper scan path planning can then be provided with an aim to reduce the occurrence of outliers. Further, the observed dependency of outlier formation on scanning orientation can be exploited to facilitate effective and automatic outlier detection and removal.

  19. 3-D patterning of silicon by laser-initiated, liquid-assisted colloidal (LILAC) lithography.

    PubMed

    Ulmeanu, M; Grubb, M P; Jipa, F; Quignon, B; Ashfold, M N R

    2015-06-01

    We report a comprehensive study of laser-initiated, liquid-assisted colloidal (LILAC) lithography, and illustrate its utility in patterning silicon substrates. The method combines single shot laser irradiation (frequency doubled Ti-sapphire laser, 50fs pulse duration, 400nm wavelength) and medium-tuned optical near-field effects around arrays of silica colloidal particles to achieve 3-D surface patterning of silicon. A monolayer (or multilayers) of hexagonal close packed silica colloidal particles act as a mask and offer a route to liquid-tuned optical near field enhancement effects. The resulting patterns are shown to depend on the difference in refractive index of the colloidal particles (ncolloid) and the liquid (nliquid) in which they are immersed. Two different topographies are demonstrated experimentally: (a) arrays of bumps, centred beneath the original colloidal particles, when using liquids with nliquidncolloid - and explained with the aid of complementary Mie scattering simulations. The LILAC lithography technique has potential for rapid, large area, organized 3-D patterning of silicon (and related) substrates.

  20. Application of a hybrid 3D-2D laser scanning system to the characterization of slate slabs.

    PubMed

    López, Marcos; Martínez, Javier; Matías, José María; Vilán, José Antonio; Taboada, Javier

    2010-01-01

    Dimensional control based on 3D laser scanning techniques is widely used in practice. We describe the application of a hybrid 3D-2D laser scanning system to the characterization of slate slabs with structural defects that are difficult for the human eye to characterize objectively. Our study is based on automating the process using a 3D laser scanner and a 2D camera. Our results demonstrate that the application of this hybrid system optimally characterizes slate slabs in terms of the defects described by the Spanish UNE-EN 12326-1 standard.

  1. Automatic Reconstruction of 3D Building Models from Terrestrial Laser Scanner Data

    NASA Astrophysics Data System (ADS)

    El Meouche, R.; Rezoug, M.; Hijazi, I.; Maes, D.

    2013-11-01

    With modern 3D laser scanners we can acquire a large amount of 3D data in only a few minutes. This technology results in a growing number of applications ranging from the digitalization of historical artifacts to facial authentication. The modeling process demands a lot of time and work (Tim Volodine, 2007). In comparison with the other two stages, the acquisition and the registration, the degree of automation of the modeling stage is almost zero. In this paper, we propose a new surface reconstruction technique for buildings to process the data obtained by a 3D laser scanner. These data are called a point cloud which is a collection of points sampled from the surface of a 3D object. Such a point cloud can consist of millions of points. In order to work more efficiently, we worked with simplified models which contain less points and so less details than a point cloud obtained in situ. The goal of this study was to facilitate the modeling process of a building starting from 3D laser scanner data. In order to do this, we wrote two scripts for Rhinoceros 5.0 based on intelligent algorithms. The first script finds the exterior outline of a building. With a minimum of human interaction, there is a thin box drawn around the surface of a wall. This box is able to rotate 360° around an axis in a corner of the wall in search for the points of other walls. In this way we can eliminate noise points. These are unwanted or irrelevant points. If there is an angled roof, the box can also turn around the edge of the wall and the roof. With the different positions of the box we can calculate the exterior outline. The second script draws the interior outline in a surface of a building. By interior outline we mean the outline of the openings like windows or doors. This script is based on the distances between the points and vector characteristics. Two consecutive points with a relative big distance will form the outline of an opening. Once those points are found, the interior outline

  2. Mesoscale 3D manufacturing: varying focusing conditions for efficient direct laser writing of polymers

    NASA Astrophysics Data System (ADS)

    Jonušauskas, Linas; Malinauskas, Mangirdas

    2014-05-01

    In this paper, we report a novel approach for efficient fabrication of mesoscale polymer 3D microstructures. It is implemented by direct laser writing varying exposure beam focusing conditions. By carefully optimizing the fabrication parameters (laser intensity, scanning velocity/exposure time, changing objective lens) complex 3D geometries of the microstructures can be obtained rapidly. Additionally, we demonstrate this without the use of the photoinitiator as photosensitizer doped in the pre-polymer material (SZ2080). At femtosecond pulsed irradiation ~TW/cm² intensities the localized free radical polymerization is achieved via avalanche induced bond braking. Such microstructures have unique biocompatibility and optical transparency as well as optical damage threshold value. By creating the bulk part of the structure using low-NA (0.45) objective and subsequently fabricating the fine features using oil immersion high-NA (1.4) objective the manufacturing time is reduced dramatically (30x is demonstrated). Using this two objective method a prototype of functional microdevice was produced: 80 and 85 µm diameter microfluidic tubes with the fine filter consisting of 4 µm period grating structure that has 400 nm wide threads, which corresponds to a feature precision aspect ratio of ~200. Therefore, such method has great potential as a polymer fabrication tool for mesoscale optical, photonic and biomedical applications as well as highly integrated 3D µ-systems. Furthermore, the proposed approach is not limited to lithography and can be implemented in a more general type of laser writing, such as inscription within transparent materials or substractive manufacturing by ablation.

  3. Analysis of Uncertainty and Repeatability of a Low-Cost 3D Laser Scanner

    PubMed Central

    Polo, María-Eugenia; Felicísimo, Ángel M.

    2012-01-01

    Portable 3D laser scanners are a valuable tool for compiling elaborate digital collections of archaeological objects and analysing the shapes and dimensions of pieces. Although low-cost desktop 3D laser scanners have powerful capacities, it is important to know their limitations. This paper performs an analysis of the uncertainty and repeatability of the NextEngine™ portable low-cost 3D laser scanner by scanning an object 20 times in two different resolution modes—Macro and Wide. Some dimensions of the object were measured using a digital calliper, and these results were used as the “true” or control data. In comparing the true and the scanned data, we verified that the mean uncertainty in the Macro Mode is approximately half that of the Wide Mode, at ±0.81 mm and ±1.66 mm, respectively. These experimental results are significantly higher than the accuracy specifications provided by the manufacturer. An analysis of repeatability shows that the successive replicates do not match in the same position. The results are better in Macro Mode than in Wide Mode; it is observed that the repeatability factor is slightly larger than the corresponding mode accuracy, with ±0.84 vs. ±0.81 mm in Macro Mode and ±1.82 vs. ±1.66 mm in Wide Mode. We suggest several improvements, such as adding an external reference scale or providing a calibrated object to allow for a self-calibration operation of the scanner. PMID:23012532

  4. Determining the 3-D structure and motion of objects using a scanning laser range sensor

    NASA Astrophysics Data System (ADS)

    Nandhakumar, N.; Smith, Philip W.

    1993-12-01

    In order for the EVAHR robot to autonomously track and grasp objects, its vision system must be able to determine the 3-D structure and motion of an object from a sequence of sensory images. This task is accomplished by the use of a laser radar range sensor which provides dense range maps of the scene. Unfortunately, the currently available laser radar range cameras use a sequential scanning approach which complicates image analysis. Although many algorithms have been developed for recognizing objects from range images, none are suited for use with single beam, scanning, time-of-flight sensors because all previous algorithms assume instantaneous acquisition of the entire image. This assumption is invalid since the EVAHR robot is equipped with a sequential scanning laser range sensor. If an object is moving while being imaged by the device, the apparent structure of the object can be significantly distorted due to the significant non-zero delay time between sampling each image pixel. If an estimate of the motion of the object can be determined, this distortion can be eliminated; but, this leads to the motion-structure paradox - most existing algorithms for 3-D motion estimation use the structure of objects to parameterize their motions. The goal of this research is to design a rigid-body motion recovery technique which overcomes this limitation. The method being developed is an iterative, linear, feature-based approach which uses the non-zero image acquisition time constraint to accurately recover the motion parameters from the distorted structure of the 3-D range maps. Once the motion parameters are determined, the structural distortion in the range images is corrected.

  5. Directionality in laser fabrication of 3D graphitic microwires in diamond

    NASA Astrophysics Data System (ADS)

    Sun, B.; Salter, P. S.; Booth, M. J.

    2016-03-01

    Graphitic wires embedded beneath the surface of single crystal diamond are promising for a variety of applications. Through a combination of ultra short (femtosecond) pulsed fabrication, high numerical aperture focusing and adaptive optics, graphitic wires can be written along any 3D path. Here, we demonstrate a non-reciprocal directional dependence to the graphitization process: the features are distinct when the fabrication direction is reversed. The non-reciprocal effects are significantly determined by the laser power, the fabrication speed, the light polarization and pulse front tilt. The influences of these factors are studied.

  6. 3D handheld laser scanner based approach for automatic identification and localization of EEG sensors.

    PubMed

    Koessler, Laurent; Cecchin, Thierry; Ternisien, Eric; Maillard, Louis

    2010-01-01

    This paper describes and assesses for the first time the use of a handheld 3D laser scanner for scalp EEG sensor localization and co-registration with magnetic resonance images. Study on five subjects showed that the scanner had an equivalent accuracy, a better repeatability, and was faster than the reference electromagnetic digitizer. According to electrical source imaging, somatosensory evoked potentials experiments validated its ability to give precise sensor localization. With our automatic labeling method, the data provided by the scanner could be directly introduced in the source localization studies.

  7. Robust statistical approaches for local planar surface fitting in 3D laser scanning data

    NASA Astrophysics Data System (ADS)

    Nurunnabi, Abdul; Belton, David; West, Geoff

    2014-10-01

    This paper proposes robust methods for local planar surface fitting in 3D laser scanning data. Searching through the literature revealed that many authors frequently used Least Squares (LS) and Principal Component Analysis (PCA) for point cloud processing without any treatment of outliers. It is known that LS and PCA are sensitive to outliers and can give inconsistent and misleading estimates. RANdom SAmple Consensus (RANSAC) is one of the most well-known robust methods used for model fitting when noise and/or outliers are present. We concentrate on the recently introduced Deterministic Minimum Covariance Determinant estimator and robust PCA, and propose two variants of statistically robust algorithms for fitting planar surfaces to 3D laser scanning point cloud data. The performance of the proposed robust methods is demonstrated by qualitative and quantitative analysis through several synthetic and mobile laser scanning 3D data sets for different applications. Using simulated data, and comparisons with LS, PCA, RANSAC, variants of RANSAC and other robust statistical methods, we demonstrate that the new algorithms are significantly more efficient, faster, and produce more accurate fits and robust local statistics (e.g. surface normals), necessary for many point cloud processing tasks. Consider one example data set used consisting of 100 points with 20% outliers representing a plane. The proposed methods called DetRD-PCA and DetRPCA, produce bias angles (angle between the fitted planes with and without outliers) of 0.20° and 0.24° respectively, whereas LS, PCA and RANSAC produce worse bias angles of 52.49°, 39.55° and 0.79° respectively. In terms of speed, DetRD-PCA takes 0.033 s on average for fitting a plane, which is approximately 6.5, 25.4 and 25.8 times faster than RANSAC, and two other robust statistical methods, respectively. The estimated robust surface normals and curvatures from the new methods have been used for plane fitting, sharp feature

  8. Laser scanning confocal microscopy and laser tweezers based experiments to understand dentine-bacteria interactions

    NASA Astrophysics Data System (ADS)

    Peng, Sum Chee; Mohanty, Samarendra; Gupta, P. K.; Kishen, Anil

    2007-02-01

    Failure of endodontic treatment is commonly due to Enterococcal infection. In this study influence of chemical treatments of type-I collagen membrane by chemical agents commonly used in endodontic treatment on Enterococcus faecalis cell adherence was evaluated. In order to determine the change in number of adhering bacteria after chemical treatment, confocal laser scanning microscopy was used. For this, overnight culture of E faecalis in All Culture broth was applied to chemically treated type-I collagen membrane. It was found that Ca(OH) II treated groups had statistically significant (p value=0.05) increase in population of bacteria adherence. The change in adhesion force between bacteria and collagen was determined by using optical tweezers (1064 nm). For this experiment, Type-I collagen membrane was soaked for 5 mins in a media that contained 50% all culture media and 50% saturated Ca(OH) II . The membrane was spread on the coverslip, on which diluted bacterial suspension was added. The force of laser tweezers on the bacteria was estimated at different trap power levels using viscous drag method and trapping stiffness was calculated using Equipartition theorem method. Presence of Ca(OH) II was found to increase the cell-substrate adherence force from 0.38pN to >2.1pN. Together, these experiments show that it was highly probable that the increase in adherence to collagen was due to a stronger adhesion in the presence of Ca (OH) II.

  9. Some Experiences in 3D Laser Scanning for Assisting Restoration and Evaluating Damage in Cultural Heritage

    NASA Astrophysics Data System (ADS)

    Fuentes, L. M.; Finat, Javier; Fernández-Martin, J. J.; Martínez, J.; SanJose, J. I.

    The recent incorporation of laser devices provides advanced tools for assisting the conservation and restoration of Cultural Heritage. It is necessary to have as complete as possible understanding of the object state before evaluating or defining the reach of the restoration process. Thus, a special effort is devoted to surveying, measuring and generating a high-resolution 3D model prior to restoration planning. This work presents results of several experiments performed on damaged pieces for evaluation purposes in Cultural Heritage. Some software tools are applied for carving-work analysis, conservation-state monitoring, and simulation of weathering processes for evaluating temporal changes. In all cases considered, a high resolution information capture has been performed with a laser scanner, the Minolta 910. Our approach is flexible enough to be adapted to other kinds of pieces or Cultural Heritage artefacts, in order to provide an assessment for intervention planning in conservation and restoration tasks.

  10. Fusion of 3D laser scanner and depth images for obstacle recognition in mobile applications

    NASA Astrophysics Data System (ADS)

    Budzan, Sebastian; Kasprzyk, Jerzy

    2016-02-01

    The problem of obstacle detection and recognition or, generally, scene mapping is one of the most investigated problems in computer vision, especially in mobile applications. In this paper a fused optical system using depth information with color images gathered from the Microsoft Kinect sensor and 3D laser range scanner data is proposed for obstacle detection and ground estimation in real-time mobile systems. The algorithm consists of feature extraction in the laser range images, processing of the depth information from the Kinect sensor, fusion of the sensor information, and classification of the data into two separate categories: road and obstacle. Exemplary results are presented and it is shown that fusion of information gathered from different sources increases the effectiveness of the obstacle detection in different scenarios, and it can be used successfully for road surface mapping.

  11. A confocal scanning laser ophthalmoscope for retinal vessel oximetry

    NASA Astrophysics Data System (ADS)

    Lompado, Arthur

    Measurement of a person's blood oxygen saturation has long been recognized as a useful metric for the characterizing ailments ranging from chronic respiratory disorders to acute, potentially life threatening, traumas. The ubiquity of oxygen saturation monitors in the medical field, including portable pulse oximeters and laboratory based CO-oximeters, is a testament to the importance of this technique. The work presented here documents the design, fabrication and development of a unique type of oxygen saturation monitor, a confocal scanning retinal vessel oximeter, with the potential to expand the usefulness of the present devices. A large part of the knowledge base required to construct the instrument comes from the consideration of light scattering by red blood cells in a blood vessel. Therefore, a substantial portion of this work is devoted to the process of light scattering by whole human blood and its effects on the development of a more accurate oximeter. This light scattering effect has been both measured and modeled stochastically to determine its contribution to the measured oximeter signal. It is shown that, although well accepted in the published literature, the model only correlates marginally to the measurements due to inherent limitations imposed by the model assumptions. Nonetheless, enough material has been learned about the scattering to allow development of a mathematical model for the interaction of light with blood in a vessel, and this knowledge has been applied to the data reduction of the present oximeter. This data reduction technique has been tested in a controlled experiment employing a model eye with a blood filled mock retinal vessel. It will be shown that the presently developed technique exhibited strong correlation between the known blood oxygen saturation and that calculated by the new system.

  12. Multispectral confocal scanning laser ophthalmoscope for retinal vessel oximetry

    NASA Astrophysics Data System (ADS)

    Lompado, Arthur; Smith, Matthew H.; Hillman, Lloyd W.; Denninghoff, Kurt R.

    2000-03-01

    Scanning laser microscopy is a widely used technique in ophthalmoscopy for providing high-resolution real time images of the retina. We describe a scanning laser ophthalmoscope that acquires retinal images at four wavelengths for the purpose of measuring the oxygen saturation of blood in retinal arteries and veins. Images at all four wavelengths are obtained across a single video frame using a temporal interlacing technique. An extraction procedure then permits analysis of four monochromatic images. A technique for calculating oxygen saturation from a multi-spectral image set is presented, along with preliminary measurements. The choice of wavelengths dramatically affects the oxygen saturation calculation accuracy and we present an optimized wavelength set and the calculated oxygen saturation results. The potential applications for this technology range from the diagnosis of various ophthalmic diseases to the detection of blood loss in trauma victims.

  13. Photoinitiator-free 3D scaffolds fabricated by excimer laser photocuring.

    PubMed

    Farkas, Balázs; Dante, Silvia; Brandi, Fernando

    2017-01-20

    Photoinitiator-free fabrication of poly(ethylene glycol) diacrylate (PEGDA) scaffolds is achieved using a novel three-dimensional (3D) printing method called mask projected excimer laser stereolithography (MPExSL). The spatial resolution of photoinitiator-free curing is suitable for 3D layer-by-layer fabrication with a single layer thickness well controllable at tens to hundreds of microns using 248 nm wavelength for the irradiation. The photoinitiator-free scaffolds are superior compared to their counterparts fabricated by using photoinitiator molecules, showing a higher level of biocompatibility. A release of toxic chemicals from the photoinitiator containing scaffolds is proven by cell proliferation tests. In contrast, no toxic release is found from the photoinitiator-free scaffolds, resulting in the very same level of cell proliferation as the control sample. The demonstration of photoinitiator-free PEGDA scaffolds enables the fabrication of 3D scaffolds with the highest level of biocompatibility for both in vitro and in vivo applications.

  14. Error Analysis of Terrestrial Laser Scanning Data by Means of Spherical Statistics and 3D Graphs

    PubMed Central

    Cuartero, Aurora; Armesto, Julia; Rodríguez, Pablo G.; Arias, Pedro

    2010-01-01

    This paper presents a complete analysis of the positional errors of terrestrial laser scanning (TLS) data based on spherical statistics and 3D graphs. Spherical statistics are preferred because of the 3D vectorial nature of the spatial error. Error vectors have three metric elements (one module and two angles) that were analyzed by spherical statistics. A study case has been presented and discussed in detail. Errors were calculating using 53 check points (CP) and CP coordinates were measured by a digitizer with submillimetre accuracy. The positional accuracy was analyzed by both the conventional method (modular errors analysis) and the proposed method (angular errors analysis) by 3D graphics and numerical spherical statistics. Two packages in R programming language were performed to obtain graphics automatically. The results indicated that the proposed method is advantageous as it offers a more complete analysis of the positional accuracy, such as angular error component, uniformity of the vector distribution, error isotropy, and error, in addition the modular error component by linear statistics. PMID:22163461

  15. Photoinitiator-free 3D scaffolds fabricated by excimer laser photocuring

    NASA Astrophysics Data System (ADS)

    Farkas, Balázs; Dante, Silvia; Brandi, Fernando

    2017-01-01

    Photoinitiator-free fabrication of poly(ethylene glycol) diacrylate (PEGDA) scaffolds is achieved using a novel three-dimensional (3D) printing method called mask projected excimer laser stereolithography (MPExSL). The spatial resolution of photoinitiator-free curing is suitable for 3D layer-by-layer fabrication with a single layer thickness well controllable at tens to hundreds of microns using 248 nm wavelength for the irradiation. The photoinitiator-free scaffolds are superior compared to their counterparts fabricated by using photoinitiator molecules, showing a higher level of biocompatibility. A release of toxic chemicals from the photoinitiator containing scaffolds is proven by cell proliferation tests. In contrast, no toxic release is found from the photoinitiator-free scaffolds, resulting in the very same level of cell proliferation as the control sample. The demonstration of photoinitiator-free PEGDA scaffolds enables the fabrication of 3D scaffolds with the highest level of biocompatibility for both in vitro and in vivo applications.

  16. Laser-Micro/Nanofabricated 3D Polymers for Tissue Engineering Applications

    NASA Astrophysics Data System (ADS)

    Danilevičius, P.; Žukauskas, A.; Bičkauskaitė, G.; Purlys, V.; Rutkauskas, M.; Gertus, T.; Paipulas, D.; Matukaitė, J.; Baltriukienė, D.; Malinauskas, M.

    2011-01-01

    A multi-photon polymerization system has been designed based on a pulsed irradiation light source (diode-pumped solid state femtosecond laser Yb:KGW, 300 fs, 1030 nm, 1-200 kHz) in combination with large working area and high precision linear motor driven stages (100×100×50 mm3). The system is intended for high resolution and throughput 3D micro- and nanofabrication and enables manufacturing the polymeric templates up to 1 cm2 areas with sub-micrometer resolution. These can be used for producing 3D artificial polymeric scaffolds to be applied for growing cells, specifically, in the tissue engineering. The bio-compatibility of different acrylate, hybrid organic-inorganic and biodegradable polymeric materials is evaluated experimentally in vitro. Variously sized and shaped polymeric scaffolds of biocompatible photopolymers with intricate 3D geometry were successfully fabricated. Proliferation tests for adult rabbit myogenic stem cells have shown the applicability of artificial scaffolds in biomedicine practice.

  17. Novel eye-safe line scanning 3D laser-radar

    NASA Astrophysics Data System (ADS)

    Eberle, B.; Kern, Tobias; Hammer, Marcus; Schwanke, Ullrich; Nowak, Heinrich

    2014-10-01

    Today, the civil market provides quite a number of different 3D-Sensors covering ranges up to 1 km. Typically these sensors are based on single element detectors which suffer from the drawback of spatial resolution at larger distances. Tasks demanding reliable object classification at long ranges can be fulfilled only by sensors consisting of detector arrays. They ensure sufficient frame rates and high spatial resolution. Worldwide there are many efforts in developing 3D-detectors, based on two-dimensional arrays. This paper presents first results on the performance of a recently developed 3D imaging laser radar sensor, working in the short wave infrared (SWIR) at 1.5 μm. It consists of a novel Cadmium Mercury Telluride (CMT) linear array APD detector with 384x1 elements at a pitch of 25 μm, developed by AIM Infrarot Module GmbH. The APD elements are designed to work in the linear (non-Geiger) mode. Each pixel will provide the time of flight measurement, and, due to the linear detection mode, allowing the detection of three successive echoes. The resolution in depth is 15 cm, the maximum repetition rate is 4 kHz. We discuss various sensor concepts regarding possible applications and their dependence on system parameters like field of view, frame rate, spatial resolution and range of operation.

  18. Ultra-Rapid 2-D and 3-D Laser Microprinting of Proteins

    NASA Astrophysics Data System (ADS)

    Scott, Mark Andrew

    When viewed under the microscope, biological tissues reveal an exquisite microarchitecture. These complex patterns arise during development, as cells interact with a multitude of chemical and mechanical cues in the surrounding extracellular matrix. Tissue engineers have sought for decades to repair or replace damaged tissue, often relying on porous scaffolds as an artificial extracellular matrix to support cell development. However, these grafts are unable to recapitulate the complexity of the in vivo environment, limiting our ability to regenerate functional tissue. Biomedical engineers have developed several methods for printing two- and three-dimensional patterns of proteins for studying and directing cell development. Of these methods, laser microprinting of proteins has shown the most promise for printing sub-cellular resolution gradients of cues, but the photochemistry remains too slow to enable large-scale applications for screening and therapeutics In this work, we demonstrate a novel high-speed photochemistry based on multi-photon photobleaching of fluorescein, and we build the fastest 2-D and 3-D laser microprinter for proteins to date. First, we show that multiphoton photobleaching of a deoxygenated solution of biotin-4-fluorescein onto a PEG monolayer with acrylate end-group can enable print speeds of almost 20 million pixels per second at 600 nanometer resolution. We discovered that the mechanism of fluorescein photobleaching evolves from a 2-photon to 3- and 4-photon regime at higher laser intensities, unlocking faster printing kinetics. Using this 2-D printing system, we develop a novel triangle-ratchet method for directing the polarization of single hippocampal neurons. This ability to determine which neurite becomes an axon, and which neuritis become dendrites is an essential step for developing defined in vitro neural networks. Next, we modify our multiphoton photobleaching system to print in three dimensions. For the first time, we demonstrate 3

  19. Documentation and Instructions for Running Two Python Scripts that Aid in Setting up 3D Measurements using the Polytec 3D Scanning Laser Doppler Vibrometer.

    SciTech Connect

    Rohe, Daniel Peter

    2015-08-24

    Sandia National Laboratories has recently purchased a Polytec 3D Scanning Laser Doppler Vibrometer for vibration measurement. This device has proven to be a very nice tool for making vibration measurements, and has a number of advantages over traditional sensors such as accelerometers. The non-contact nature of the laser vibrometer means there is no mass loading due to measuring the response. Additionally, the laser scanning heads can position the laser spot much more quickly and accurately than placing an accelerometer or performing a roving hammer impact. The disadvantage of the system is that a significant amount of time must be invested to align the lasers with each other and the part so that the laser spots can be accurately positioned. The Polytec software includes a number of nice tools to aid in this procedure; however, certain portions are still tedious. Luckily, the Polytec software is readily extensible by programming macros for the system, so tedious portions of the procedure can be made easier by automating the process. The Polytec Software includes a WinWrap (similar to Visual Basic) editor and interface to run macros written in that programming language. The author, however, is much more proficient in Python, and the latter also has a much larger set of libraries that can be used to create very complex macros, while taking advantage of Python’s inherent readability and maintainability.

  20. Electromagnetic induction sounding and 3D laser imaging in support of a Mars methane analogue mission

    NASA Astrophysics Data System (ADS)

    Boivin, A.; Lai, P.; Samson, C.; Cloutis, E.; Holladay, S.; Monteiro Santos, F. A.

    2013-07-01

    The Mars Methane Analogue Mission simulates a micro-rover mission whose purpose is to detect, analyze, and determine the source of methane emissions on the planet's surface. As part of this project, both an electromagnetic induction sounder (EMIS) and a high-resolution triangulation-based 3D laser scanner were tested at the Jeffrey open-pit asbestos mine to identify and characterize geological environments favourable to the occurrence of methane. The presence of serpentinite in the form of chrysotile (asbestos), magnesium carbonate, and iron oxyhydroxides make the mine a likely location for methane production. The EMIS clearly delineated the contacts between the two geological units found at the mine, peridotite and slate, which are separated by a shear zone. Both the peridotite and slate units have low and uniform apparent electrical conductivity and magnetic susceptibility, while the shear zone has much higher conductivity and susceptibility, with greater variability. The EMIS data were inverted and the resulting model captured lateral conductivity variations through the different bedrock geological units buried beneath a gravel road. The 3D point cloud data acquired by the laser scanner were fitted with triangular meshes where steeply dipping triangles were plotted in dark grey to accentuate discontinuities. The resulting images were further processed using Sobel edge detection to highlight networks of fractures which are potential pathways for methane seepage.

  1. Mapping Nearby Terrain in 3D by Use of a Grid of Laser Spots

    NASA Technical Reports Server (NTRS)

    Padgett, Curtis; Liebe, Carl; Chang, Johnny; Brown, Kenneth

    2007-01-01

    A proposed optoelectronic system, to be mounted aboard an exploratory robotic vehicle, would be used to generate a three-dimensional (3D) map of nearby terrain and obstacles for purposes of navigating the vehicle across the terrain and avoiding the obstacles. The difference between this system and the other systems would lie in the details of implementation. In this system, the illumination would be provided by a laser. The beam from the laser would pass through a two-dimensional diffraction grating, which would divide the beam into multiple beams propagating in different, fixed, known directions. These beams would form a grid of bright spots on the nearby terrain and obstacles. The centroid of each bright spot in the image would be computed. For each such spot, the combination of (1) the centroid, (2) the known direction of the light beam that produced the spot, and (3) the known baseline would constitute sufficient information for calculating the 3D position of the spot.

  2. Freeform drop-on-demand laser printing of 3D alginate and cellular constructs.

    PubMed

    Xiong, Ruitong; Zhang, Zhengyi; Chai, Wenxuan; Huang, Yong; Chrisey, Douglas B

    2015-12-22

    Laser printing is an orifice-free printing approach and has been investigated for the printing of two-dimensional patterns and simple three-dimensional (3D) constructs. To demonstrate the potential of laser printing as an effective bioprinting technique, both straight and Y-shaped tubes have been freeform printed using two different bioinks: 8% alginate solution and 2% alginate-based mouse fibroblast suspension. It has been demonstrated that 3D cellular tubes, including constructs with bifurcated overhang structures, can be adequately fabricated under optimal printing conditions. The post-printing cell viabilities immediately after printing as well as after 24 h incubation are above 60% for printed straight and Y-shaped fibroblast tubes. During fabrication, overhang and spanning structures can be printed using a dual-purpose crosslinking solution, which also functions as a support material. The advancement distance of gelation reaction front after a cycle time of the receiving platform downward motion should be estimated for experimental planning. The optimal downward movement step size of receiving platform should be chosen to be equal to the height of ungelled portion of a previously printed layer.

  3. Development of a high-resolution laser radar for 3D imaging in artwork cataloging

    NASA Astrophysics Data System (ADS)

    Bordone, Andrea; Ferri De Collibus, Mario; Fantoni, Roberta; Fornetti, Giorgio G.; Guarneri, Marianna; Poggi, Claudio; Ricci, Roberto

    2003-04-01

    A high resolution Amplitude Modulation Laser Radar (AM-LR) sensor has recently been developed, aimed at accurately reconstructing 3D digital models of real targets -- either single objects or complex scenes. The sensor sounding beam can be swept linearly across the object or circularly around it, by placing the object on a controlled rotation platform. Both intensity and phase shift of the back-scattered light are then collected and processed, providing respectively a shade-free photographic-like picture and accurate range data in the form of a range or depth image, with resolution depending mainly on the laser modulation frequency. Starting from the sample points, with an uncertainty that can be made as small as 100 μm, the complete object surface can be reconstructed by using specifically developed software tools. The system has been successfully applied to scan different types of real surfaces (stone, wood, bones) and is expected to have significant applications in industrial machining, artwork cataloguing and medical diagnostics. Examples of 3D reconstructions are presented and the relevance of this technology for reverse engineering applied to artwork restoration and conservation is briefly discussed.

  4. The development of laser-plasma interaction program LAP3D on thousands of processors

    SciTech Connect

    Hu, Xiaoyan Hao, Liang; Liu, Zhanjun; Zheng, Chunyang; Li, Bin Guo, Hong

    2015-08-15

    Modeling laser-plasma interaction (LPI) processes in real-size experiments scale is recognized as a challenging task. For explorering the influence of various instabilities in LPI processes, a three-dimensional laser and plasma code (LAP3D) has been developed, which includes filamentation, stimulated Brillouin backscattering (SBS), stimulated Raman backscattering (SRS), non-local heat transport and plasmas flow computation modules. In this program, a second-order upwind scheme is applied to solve the plasma equations which are represented by an Euler fluid model. Operator splitting method is used for solving the equations of the light wave propagation, where the Fast Fourier translation (FFT) is applied to compute the diffraction operator and the coordinate translations is used to solve the acoustic wave equation. The coupled terms of the different physics processes are computed by the second-order interpolations algorithm. In order to simulate the LPI processes in massively parallel computers well, several parallel techniques are used, such as the coupled parallel algorithm of FFT and fluid numerical computation, the load balance algorithm, and the data transfer algorithm. Now the phenomena of filamentation, SBS and SRS have been studied in low-density plasma successfully with LAP3D. Scalability of the program is demonstrated with a parallel efficiency above 50% on about ten thousand of processors.

  5. Laser Scanning for 3D Object Characterization: Infrastructure for Exploration and Analysis of Vegetation Signatures

    NASA Astrophysics Data System (ADS)

    Koenig, K.; Höfle, B.

    2012-04-01

    Mapping and characterization of the three-dimensional nature of vegetation is increasingly gaining in importance. Deeper insight is required for e.g. forest management, biodiversity assessment, habitat analysis, precision agriculture, renewable energy production or the analysis of interaction between biosphere and atmosphere. However the potential of 3D vegetation characterization has not been exploited so far and new technologies are needed. Laser scanning has evolved into the state-of-the-art technology for highly accurate 3D data acquisition. By now several studies indicated a high value of 3D vegetation description by using laser data. The laser sensors provide a detailed geometric presentation (geometric information) of scanned objects as well as a full profile of laser energy that was scattered back to the sensor (radiometric information). In order to exploit the full potential of these datasets, profound knowledge on laser scanning technology for data acquisition, geoinformation technology for data analysis and object of interest (e.g. vegetation) for data interpretation have to be joined. A signature database is a collection of signatures of reference vegetation objects acquired under known conditions and sensor parameters and can be used to improve information extraction from unclassified vegetation datasets. Different vegetation elements (leaves, branches, etc.) at different heights above ground with different geometric composition contribute to the overall description (i.e. signature) of the scanned object. The developed tools allow analyzing tree objects according to single features (e.g. echo width and signal amplitude) and to any relation of features and derived statistical values (e.g. ratio of laser point attributes). For example, a single backscatter cross section value does not allow for tree species determination, whereas the average echo width per tree segment can give good estimates. Statistical values and/or distributions (e.g. Gaussian

  6. 3D integration of microcomponents in a single glass chip by femtosecond laser direct writing for biochemical analysis

    NASA Astrophysics Data System (ADS)

    Sugioka, Koji; Hanada, Yasutaka; Midorikawa, Katsumi

    2007-05-01

    3D integration of microcomponents in a single glass chip by femtosecond laser direct writing followed by post annealing and successive wet etching is described for application to biochemical analysis. Integration of microfluidics and microoptics realized some functional microdevices like a μ-fluidic dye laser and a biosensor. As one of practical applications, we demonstrate inspection of living microorganisms using the microchip with 3D microfluidic structures fabricated by the present technique.

  7. 3D modelling of facade features on large sites acquired by vehicle based laser scanning

    NASA Astrophysics Data System (ADS)

    Boulaassal, H.; Landes, T.; Grussenmeyer, P.

    2011-12-01

    Mobile mapping laser scanning systems have become more and more widespread for the acquisition of millions of 3D points on large and geometrically complex urban sites. Vehicle-based Laser Scanning (VLS) systems travel many kilometers while acquiring raw point clouds which are registered in real time in a common coordinate system. Improvements of the acquisition steps as well as the automatic processing of the collected point clouds are still a conundrum for researchers. This paper shows some results obtained by application, on mobile laser scanner data, of segmentation and reconstruction algorithms intended initially to generate individual vector facade models using stationary Terrestrial Laser Scanner (TLS) data. The operating algorithms are adapted so as to take into account characteristics of VLS data. The intrinsic geometry of a point cloud as well as the relative geometry between registered point clouds are different from that obtained by a static TLS. The amount of data provided by this acquisition technique is another issue. Such particularities should be taken into consideration while processing this type of point clouds. The segmentation of VLS data is carried out based on an adaptation of RANSAC algorithm. Edge points of each element are extracted by applying a second algorithm. Afterwards, the vector models of each facade element are reconstructed. In order to validate the results, large samples with different characteristics have been introduced in the developed processing chain. The limitations as well as the capabilities of each process will be emphasized in terms of geometry and processing time.

  8. Production of 3D consistent image representation of outdoor scenery for multimedia ambiance communication from multiviewpoint range data measured with a 3D laser scanner

    NASA Astrophysics Data System (ADS)

    Saito, Takahiro; Imamura, Hiroshi; Sunaga, Shin-ichi; Komatsu, Takashi

    2002-03-01

    Toward future 3D image communication, we have started studying the Multimedia Ambiance Communication, a kind of shared-space communication, and adopted an approach to design the 3D-image space using actual images of outdoor scenery, by introducing the concept of the three-layer model of long-, mid- and short-range views. The long- and mid-range views do not require precise representation of their 3D structure, and hence we employ the setting representation like stage settings to approximate their 3D structure according to the slanting-plane-model. We deal with an approach to produce the consistent setting representation for describing long- and mid-range views from range and texture data measured with a laser scanner and a digital camera located at multiple viewpoints. The production of such a representation requires the development of several techniques: nonlinear smoothing of raw range data, plane segmentation of range data, registration of multi-viewpoint range data, integration of multi-viewpoint setting representations and texture mapping onto each setting plane. In this paper, we concentrate on the plane segmentation and the multi-viewpoint data registration. Our plane segmentation method is based on the concept of the region competition, and can precisely extract fitting planes from the range data. Our registration method uses the equations of the segmented planes corresponding between two different viewpoints to determine the 3D Euclidean transformation between them. A unifying consistent setting representation can be constructed by integrating multiple setting representations for multiple viewpoints.

  9. Methylene-blue aided rapid confocal laser endomicroscopy of breast cancer

    NASA Astrophysics Data System (ADS)

    Vyas, Khushi; Hughes, Michael; Leff, Daniel Richard; Yang, Guang-Zhong

    2017-02-01

    Breast conserving surgery allows complete tumor resection while maintaining acceptable cosmesis for patients. Safe and rapid intraoperative margin assessment during the procedure is important to establish the completeness of tumor excision and minimizes the need for reoperation. Confocal laser endomicroscopy has demonstrated promise for real-time intraoperative margin assessment using acriflavine staining, but it is not approved for routine in-human use. We describe a custom high-speed line-scan confocal laser endomicroscopy (LS-CLE) system at 660 nm that enables high-resolution histomorphological imaging of breast tissue stained with methylene-blue, an alternative fluorescent stain for localizing sentinel nodes during breast surgery. Preliminary imaging results on freshly excised human breast tissue specimens are presented, demonstrating the potential of methylene-blue aided rapid LS-CLE to determine the oncological status of surgical margins in-vivo.

  10. Confocal laser endomicroscopy and immunoendoscopy for real-time assessment of vascularization in gastrointestinal malignancies.

    PubMed

    Gheonea, Dan Ionuţ; Cârţână, Tatiana; Ciurea, Tudorel; Popescu, Carmen; Bădărău, Anca; Săftoiu, Adrian

    2011-01-07

    Gastrointestinal cancers represent a major cause of morbidity and mortality, with incomplete response to chemotherapy in the advanced stages and poor prognosis. Angiogenesis plays a crucial part in tumor growth and metastasis, with most gastrointestinal cancers depending strictly on the development of a new and devoted capillary network. Confocal laser endomicroscopy is a new technology which allows in vivo microscopic analysis of the gastrointestinal mucosa and its microvascularization during ongoing endoscopy by using topically or systemically administered contrast agents. Targeting markers of angiogenesis in association with confocal laser endomicroscopic examination (immunoendoscopy), as a future challenge, will add functional analysis to the morphological aspect of the neoplastic process. This review describes previous experience in endomicroscopic examination of the upper and lower digestive tract with emphasis on vascularization, resulting in a broad spectrum of potential clinical applications, and also preclinical research that could be translated to human studies.

  11. Confocal scanning laser microscopy and quantitative image analysis: application to cream cheese microstructure investigation.

    PubMed

    Fenoul, F; Le Denmat, M; Hamdi, F; Cuvelier, G; Michon, C

    2008-04-01

    The naked eye observation of cream cheese confocal scanning laser microscopy images only provides qualitative information about its microstructure. Because those products are dense dairy gels, confocal scanning laser microscopy images of 2 different cream cheeses may appear close. Quantitative image analysis is then necessary to compensate for human eye deficiency (e.g., lack of precision, subjectivity). Two kinds of quantitative image analysis were performed in this study: high-order statistical methods and grayscale mathematical morphology. They were applied to study the microstructure of 3 different cream cheeses (same manufacturing process, same dry matter content, but different fat and protein contents). Advantages and drawbacks of both methods are reviewed. The way they may be used to describe cream cheese microstructure is also presented.

  12. Ultrasonic enrichment of microspheres for ultrasensitive biomedical analysis in confocal laser-scanning fluorescence detection

    NASA Astrophysics Data System (ADS)

    Wiklund, M.; Toivonen, J.; Tirri, M.; Hänninen, P.; Hertz, H. M.

    2004-07-01

    An ultrasonic particle concentrator based on a standing-wave hemispherical resonator is combined with confocal laser-scanning fluorescence detection. The goal is to perform ultrasensitive biomedical analysis by concentration of biologically active microspheres. The standing-wave resonator consists of a 4 MHz focusing ultrasonic transducer combined with the optically transparent plastic bottom of a disposable 96-well microplate platform. The ultrasonic particle concentrator collects suspended microspheres into dense, single-layer aggregates at well-defined positions in the sample vessel of the microplate, and the fluorescence from the aggregates is detected by the confocal laser-scanning system. The biochemical properties of the system are investigated using a microsphere-based human thyroid stimulating hormone assay.

  13. Application of laser differential confocal technique in back vertex power measurement for phoropters

    NASA Astrophysics Data System (ADS)

    Li, Fei; Li, Lin; Ding, Xiang; Liu, Wenli

    2012-10-01

    A phoropter is one of the most popular ophthalmic instruments used in optometry and the back vertex power (BVP) is one of the most important parameters to evaluate the refraction characteristics of a phoropter. In this paper, a new laser differential confocal vertex-power measurement method which takes advantage of outstanding focusing ability of laser differential confocal (LDC) system is proposed for measuring the BVP of phoropters. A vertex power measurement system is built up. Experimental results are presented and some influence factor is analyzed. It is demonstrated that the method based on LDC technique has higher measurement precision and stronger environmental anti-interference capability compared to existing methods. Theoretical analysis and experimental results indicate that the measurement error of the method is about 0.02m-1.

  14. Fiber optic confocal laser Doppler velocimeter using an all-fiber laser source for high resolution measurements.

    PubMed

    Sharma, Utkarsh; Chen, Gang; Kang, Jin; Ilev, Ilko; Waynant, Ronald

    2005-08-08

    We demonstrate and analyze a novel fiber optic confocal laser Doppler velocimeter using an ultra-narrow linewidth all-fiber laser source centered at around 1550 nm (eye-safe region). The narrow spectral linewidth of the fiber laser (<10 kHz) is used to achieve an extremely high velocity resolution (~0.0075 m/s), which is an order of magnitude better as compared to the commonly used semiconductor diode lasers or He-Ne lasers based systems. The directional optical circulator based design used in our system is much simpler to implement and is power conserving compared to the conventional Michelson interferometer based designs. We perform Gaussian beam propagation analysis by using the ABCD law to study the performance of the confocal design. The analysis is in good accord with our experimental results. The confocal design is capable of providing ultrahigh spatial resolution (~5microm, in both lateral and longitudinal directions) for high-precision velocity distribution measurement applications.

  15. UNDERSTANDING THE EFFECTS OF SURFACTANT ADDITION ON RHEOLOGY USING LASER SCANNING CONFOCAL MICROSCOPY

    SciTech Connect

    White, T

    2007-05-08

    The effectiveness of three dispersants to modify rheology was examined using rheology measurements and laser scanning confocal microscopy (LSCM) in simulated waste solutions. All of the dispersants lowered the yield stress of the slurries below the baseline samples. The rheology curves were fitted reasonably to a Bingham Plastic model. The three-dimensional LSCM images of simulants showed distinct aggregates were greatly reduced after the addition of dispersants leading to a lowering of the yield stress of the simulated waste slurry solutions.

  16. Video rate confocal laser scanning reflection microscopy in the investigation of normal and neoplastic living cell dynamics.

    PubMed

    Vesely, P; Boyde, A

    1996-01-01

    The introduction of video rate confocal laser scanning microscopes (VRCLSM) used in reflection mode with high magnification, high aperture objective lenses and with further magnification by a zoom facility allowed the first detailed observations of the activity of living cytoplasm and offered a new tool for investigation of the structural transition from the living state to the specimen fixed for electron microscopy (EM). We used a Noran Odyssey VRCLSM in reflection (backscattered) mode. A greater degree of oversampling and more comfortable viewing of the liver or taped video image was achieved at zoom factor 5, giving a display monitor field width of 10 microns. A series of mesenchyme derived cell lines--from normal cells to sarcoma cells of different malignancy--was used to compare behaviour of the observed intracellular structures and results of fixation. We contrasted the dynamic behaviour of fine features in the cytoplasm of normal and neoplastic living cells and changes induced by various treatments. The tubulomembraneous 3D structure of cytoplasm in living cells is dynamic with motion observable at the new limits of resolution provided by VRCLSM. All organelles appear integrated into one functional compartment supporting the continuous 3D trafficking of small particles (vesicles). This integrated dynamic spatial network (IDSN) was found to be largest in neoplastic cells.

  17. Visualization and quantification of dentin structure using confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Kimura, Yuichi; Wilder-Smith, Petra B.; Krasieva, Tatiana B.; Arrastia-Jitosho, Anna-Marie A.; Liaw, Lih-Huei L.; Matsumoto, Koukichi

    1997-07-01

    Dentin was visualized using a new fluorescence technique and confocal laser scanning microscopy. Thirty extracted human teeth showing no clinical signs of caries were investigated. All teeth were horizontally sectioned to approximately 200 micrometers thickness and sections were subjected to different pretreatment conditions as follows: vacuum only, ultrasonication only, sodium hypochlorite only, sodium hypochlorite and vacuum, sodium hypochlorite and ultrasonication, and a combination of sodium hypochlorite, vacuum, and ultrasonication. Some samples were left untreated to serve as control. Following pretreatment, rhodamine 123 fluorescent dye was used for staining at concentrations ranging from 10-3 to 10-7 M for 1 to 24 h at pH 6.0, 6.5, or 7.4. Optical staining occurred at pH 7.4 and concentrations >= 10-5 M over 3 h or longer. Surface images obtained using confocal laser scanning microscopy were similar to those observed by scanning electron microscopy without the need for sample- altering conventional scanning electron microscope preparation techniques. Subsurface imaging to a depth of approximately 60 micrometers was achieved using confocal laser microscope techniques. This fluorescence technique offers a useful new alternative for visualization and quantification of dentin.

  18. Laser machining for smooth continuous 3-D contouring for micro airflow blades

    NASA Astrophysics Data System (ADS)

    Heaton, Mark

    2005-06-01

    This paper describes an innovative excimer laser fabrication approach for profiling optimally smooth airflow contours. The research merit of the process is its use in producing a new type of electrical transducer micro-turbine using a novel axial format. The necessary micro-machining precision for this was achieved by computer-controlling a laser beam using an elevating stage to step a moving mask across a fixed mask, i.e. a variant of dynamic mask-dragging or mask-aperturing. The moving mask image was projected on to a series of flat 600 μm wide, 1000 μm deep preform surfaces, reducing each to 50 μm thickness with curvature. Precise control of each mask increment to ablation depth and focus allowed a range of 3-D curves to be realized. The ablation rate versus surface quality was optimized throughout by ablating just 300 nm per laser pulse and using 2000 pulses spread over 90 sites. The process represents a cost effective means of using basic masks to continuously shape flat surfaces in the axial direction with high aspect ratios, high speed and precision, and is applicable to both micro streamlining and the manufacture of micro expansion nozzles.

  19. Performance evaluation of laser line scanner for in-process inspection of 3D geometries

    NASA Astrophysics Data System (ADS)

    Zhou, Sen; Xu, Jian; Tao, Lei; Yan, Yu

    2016-09-01

    Non-contact measurement techniques using laser scanning have the power to deliver tremendous benefits to most notably manufacturing, and have the advantage of high speed and high detail output. However, a major obstacle to their widespread adoption in more complex on-line producing environments is their geometric constraints and low accuracy compared to the contact-based counterparts. The work presented in this paper introduces a performance evaluation test of laser line scanning for in-process inspection of 3D geometries. Some straightforward test methods that use a designed artifact are proposed. First, one work aims to experimentally investigate the location accuracy of knee point or corner point of edge features using a commercial laser stripe scanner, which is common in mechanical parts. Another work experimentally investigates the formation of outliers that may be usually promoted by reflective surfaces around surrounding area of corner point, and these outliers are characterized with large measurement errors, which significantly deteriorate the quality of the scanned point cloud data. Scanning path planning and outlier filter design are respectively discussed.

  20. Laser Fabrication of Affective 3D Objects with 1/f Fluctuation

    NASA Astrophysics Data System (ADS)

    Maekawa, Katsuhiro; Nishii, Tomohiro; Hayashi, Terutake; Akabane, Hideo; Agu, Masahiro

    The present paper describes the application of Kansei Engineering to the physical design of engineering products as well as its realization by laser sintering. We have investigated the affective information that might be included in three-dimensional objects such as a ceramic bowl for the tea ceremony. First, an X-ray CT apparatus is utilized to retrieve surface data from the teabowl, and then a frequency analysis is carried out after noise has been filtered. The surface fluctuation is characterized by a power spectrum that is in inverse proportion to the wave number f in circumference. Second, we consider how to realize the surface with a 1/f fluctuation on a computer screen using a 3D CAD model. The fluctuation is applied to a reference shape assuming that the outer surface has a spiral flow line on which unevenness is superimposed. Finally, the selective laser sintering method has been applied to the fabrication of 1/f fluctuation objects. Nylon powder is sintered layer by layer using a CO2 laser to form an artificial teabowl with complicated surface contours.

  1. Application of Confocal and Spectrally Resolved Techniques to Scanning Laser Photoluminescence Microscopy.

    NASA Astrophysics Data System (ADS)

    Bowron, John William

    Both confocal microscopes and photoluminescence wafer mapping systems are well-developed technologies, however the application of confocal techniques to photoluminescence microscopy is not common in the literature. While developing this microscope a novel design for a spectrally-resolved detection arm was implemented. The microscope shows full confocal capabilities in reflected light operation, good spectral sensitivity in the visible region and a range of possible spectral resolutions between 10 nm and 0.1 nm, however the axial response in photoluminescence operation was found to be broader than expected by a factor of two. Calculations were performed to model and understand the new microscope. Simulations of the axial-response of an infinity-connected microscope in reflected light agreed well with experimental data. A new prediction showed that under certain circumstances the maximum signal is not always obtained at best focus. This prediction was confirmed later by experiment. These calculations were extended to understand the broadening observed in photoluminescence imaging. Three factors were considered: absorption in the material, diffusion of photo-excited carriers and the high refractive index of the material. The utility of the microscope was demonstrated by using it to image several different samples. Near-infrared fluorescence imaging was demonstrated for a stained biological specimen. Auto-fluorescence imaging was demonstrated using an ultra-violet laser and spectrally-resolved images were used to distinguish between various materials in the specimen. Confocal image stacking was demonstrated in photoluminescence on a CuO sample. Confocal photoluminescence images were shown to have higher spatial resolution than non-confocal images. Quantitative information was obtained for a SiC sample containing several polytypes. The optical measurements were then correlated with X-ray diffraction measurements in order to arrive at a polytype identification scheme

  2. In vivo confocal imaging of the retina in animal models using scanning laser ophthalmoscopy.

    PubMed

    Seeliger, Mathias W; Beck, Susanne C; Pereyra-Muñoz, Naira; Dangel, Susann; Tsai, Jen-Yue; Luhmann, Ulrich F O; van de Pavert, Serge A; Wijnholds, Jan; Samardzija, Marijana; Wenzel, Andreas; Zrenner, Eberhart; Narfström, Kristina; Fahl, Edda; Tanimoto, Naoyuki; Acar, Niyazi; Tonagel, Felix

    2005-12-01

    Scanning-laser ophthalmoscopy is a technique for confocal imaging of the eye in vivo. The use of lasers of different wavelengths allows to obtain information about specific tissues and layers due to their reflection and transmission characteristics. In addition, fluorescent dyes excitable in the blue and infrared range offer a unique access to the vascular structures associated with each layer. In animal models, a further enhancement in specificity can be obtained by GFP expression under control of tissue-specific promotors. Important fields of application are studies in retinal degenerations and the follow-up of therapeutic intervention.

  3. Solid state synthesis of chitosan and its unsaturated derivatives for laser microfabrication of 3D scaffolds

    NASA Astrophysics Data System (ADS)

    Akopova, T. A.; Demina, T. S.; Bagratashvili, V. N.; Bardakova, K. N.; Novikov, M. M.; Selezneva, I. I.; Istomin, A. V.; Svidchenko, E. A.; Cherkaev, G. V.; Surin, N. M.; Timashev, P. S.

    2015-07-01

    Chitosans with various degrees of deacetylation and molecular weights and their allyl substituted derivatives were obtained through a solvent-free reaction under shear deformation in an extruder. Structure and physical-chemical analysis of the samples were carried out using nuclear magnetic resonance (NMR), ultraviolet (UV) and infrared radiation (IR) spectroscopy. Photosensitive materials based on the synthesized polymers were successfully used for microfabrication of 3D well-defined architectonic structures by laser stereolithography. Study on the metabolic activity of NCTC L929 cultured in the presence of the cured chitosan extracts indicates that the engineered biomaterials could support adhesion, spreading and growth of adherent-dependent cells, and thus could be considered as biocompatible scaffolds.

  4. A portable instrument for 3-D dynamic robot measurements using triangulation and laser tracking

    SciTech Connect

    Mayer, J.R.R. . Mechanical Engineering Dept.); Parker, G.A. . Dept. of Mechanical Engineering)

    1994-08-01

    The paper describes the development and validation of a 3-D measurement instrument capable of determining the static and dynamic performance of industrial robots to ISO standards. Using two laser beams to track an optical target attached to the robot end-effector, the target position coordinates may be estimated, relative to the instrument coordinate frame, to a high accuracy using triangulation principles. The effect of variations in the instrument geometry from the nominal model is evaluated through a kinematic model of the tracking head. Significant improvements of the measurement accuracy are then obtained by a simple adjustment of the main parameters. Extensive experimental test results are included to demonstrate the instrument performance. Finally typical static and dynamic measurement results for an industrial robot are presented to illustrate the effectiveness and usefulness of the instrument.

  5. Laser irradiated fluorescent perfluorocarbon microparticles in 2-D and 3-D breast cancer cell models

    PubMed Central

    Niu, Chengcheng; Wang, Long; Wang, Zhigang; Xu, Yan; Hu, Yihe; Peng, Qinghai

    2017-01-01

    Perfluorocarbon (PFC) droplets were studied as new generation ultrasound contrast agents via acoustic or optical droplet vaporization (ADV or ODV). Little is known about the ODV irradiated vaporization mechanisms of PFC-microparticle complexs and the stability of the new bubbles produced. In this study, fluorescent perfluorohexane (PFH) poly(lactic-co-glycolic acid) (PLGA) particles were used as a model to study the process of particle vaporization and bubble stability following excitation in two-dimensional (2-D) and three-dimensional (3-D) cell models. We observed localization of the fluorescent agent on the microparticle coating material initially and after vaporization under fluorescence microscopy. Furthermore, the stability and growth dynamics of the newly created bubbles were observed for 11 min following vaporization. The particles were co-cultured with 2-D cells to form 3-D spheroids and could be vaporized even when encapsulated within the spheroids via laser irradiation, which provides an effective basis for further work. PMID:28262671

  6. Straightforward 3D hydrodynamic focusing in femtosecond laser fabricated microfluidic channels.

    PubMed

    Paiè, Petra; Bragheri, Francesca; Vazquez, Rebeca Martinez; Osellame, Roberto

    2014-06-07

    We report on the use of femtosecond laser irradiation followed by chemical etching as a microfabrication tool for innovative microfluidic networks that implement hydrodynamic focusing. The capability of our microfabrication technology to interconnect microchannels in three dimensions was exploited to demonstrate 2D hydrodynamic focusing, either in the horizontal or in the vertical plane, and full 3D hydrodynamic focusing. In all cases only two inlets were required, one for the sample and one for the sheath flows. Fluidic characterization of all devices was provided. In addition, taking advantage of the possibility to write optical waveguides using the same technology, a monolithic cell counter based on 3D hydrodynamic focusing and integrated optical detection was validated. Counting rates up to 5000 cells s(-1) were achieved in this very compact device, where focusing and counting operations were implemented in less than 1 mm(3). Integration of this hydrodynamic focusing module into several devices fabricated by the same technology as optical cell stretchers and cell sorters is envisaged.

  7. The study of craniofacial growth patterns using 3D laser scanning and geometric morphometrics

    NASA Astrophysics Data System (ADS)

    Friess, Martin

    2006-02-01

    Throughout childhood, braincase and face grow at different rates and therefore exhibit variable proportions and positions relative to each other. Our understanding of the direction and magnitude of these growth patterns is crucial for many ergonomic applications and can be improved by advanced 3D morphometrics. The purpose of this study is to investigate this known growth allometry using 3D imaging techniques. The geometry of the head and face of 840 children, aged 2 to 19, was captured with a laser surface scanner and analyzed statistically. From each scan, 18 landmarks were extracted and registered using General Procrustes Analysis (GPA). GPA eliminates unwanted variation due to position, orientation and scale by applying a least-squares superimposition algorithm to individual landmark configurations. This approach provides the necessary normalization for the study of differences in size, shape, and their interaction (allometry). The results show that throughout adolescence, boys and girls follow a different growth trajectory, leading to marked differences not only in size but also in shape, most notably in relative proportions of the braincase. These differences can be observed during early childhood, but become most noticeable after the age of 13 years, when craniofacial growth in girls slows down significantly, whereas growth in boys continues for at least 3 more years.

  8. 3D Imaging of Nanoparticle Distribution in Biological Tissue by Laser-Induced Breakdown Spectroscopy

    PubMed Central

    Gimenez, Y.; Busser, B.; Trichard, F.; Kulesza, A.; Laurent, J. M.; Zaun, V.; Lux, F.; Benoit, J. M.; Panczer, G.; Dugourd, P.; Tillement, O.; Pelascini, F.; Sancey, L.; Motto-Ros, V.

    2016-01-01

    Nanomaterials represent a rapidly expanding area of research with huge potential for future medical applications. Nanotechnology indeed promises to revolutionize diagnostics, drug delivery, gene therapy, and many other areas of research. For any biological investigation involving nanomaterials, it is crucial to study the behavior of such nano-objects within tissues to evaluate both their efficacy and their toxicity. Here, we provide the first account of 3D label-free nanoparticle imaging at the entire-organ scale. The technology used is known as laser-induced breakdown spectroscopy (LIBS) and possesses several advantages such as speed of operation, ease of use and full compatibility with optical microscopy. We then used two different but complementary approaches to achieve 3D elemental imaging with LIBS: a volume reconstruction of a sliced organ and in-depth analysis. This proof-of-concept study demonstrates the quantitative imaging of both endogenous and exogenous elements within entire organs and paves the way for innumerable applications. PMID:27435424

  9. Diatom-inspired templates for 3D replication: natural diatoms versus laser written artificial diatoms.

    PubMed

    Belegratis, M R; Schmidt, V; Nees, D; Stadlober, B; Hartmann, P

    2014-03-01

    The diatoms are ubiquitous, exist in large numbers and show a great diversity of features on their porous silica structures. Therefore, they inspire the fabrication of nanostructured templates for nanoimprint processes (NIL), where large structured areas with nanometer precision are required. In this study, two approaches regarding the respective challenges and potential exploitations are followed and discussed: the first one takes advantage of a template that is directly made of natural occurring diatoms. Here, two replication steps via soft lithography are needed to obtain a template which is subsequently used for NIL. The second approach exploits the technical capabilities of the precise 3D laser lithography (3DLL) based on two-photon polymerization of organic materials. This method enables the fabrication of arbitrary artificial diatom-inspired micro- and nanostructures and the design of an inverse structure. Therefore, only one replication step is needed to obtain a template for NIL. In both approaches, a replication technique for true 3D structures is shown.

  10. Low-level laser therapy in 3D cell culture model using gingival fibroblasts.

    PubMed

    Basso, Fernanda G; Soares, Diana G; de Souza Costa, Carlos Alberto; Hebling, Josimeri

    2016-07-01

    Besides extensive data about the effects of low-level laser therapy (LLLT) on different cell types, so far, these results were obtained from monolayer cell culture models, which have limitations in terms of cell morphology and phenotype expression. Therefore, for better in vitro evaluation of the effects of LLLT, this study was performed with a 3D cell culture model, where gingival fibroblasts were seeded in collagen matrix. Cells isolated from a healthy patient were seeded in wells of 24-well plates with culture medium (DMEM) supplemented with 10 % fetal bovine serum and collagen type I solution. After 5 days, a serum-free DMEM was added to the matrices with cells that were subjected or not to three consecutive irradiations of LLLT by means of the LaserTABLE diode device (780 nm, 25 mW) at 0.5, 1.5, and 3 J/cm(2). Twenty-four hours after the last irradiation, cell viability and morphology as well as gene expression of growth factors were assessed. Histological evaluation of matrices demonstrated uniform distribution and morphology of gingival fibroblasts within the collagen matrix. LLLT at 3 J/cm(2) increased gingival fibroblast viability. Enhanced gene expression of hCOL-I and hEGF was observed for 0.5 J/cm(2), while no significant changes were detected for the other irradiation densities tested. In conclusion, LLLT promoted biostimulation of gingival fibroblasts seeded in a 3D cell culture model, demonstrating that this model can be applied for phototherapy studies and that LLLT could penetrate the collagen matrix to increase cell functions related to tissue repair.

  11. High-resolution laser radar for 3D imaging in artwork cataloging, reproduction, and restoration

    NASA Astrophysics Data System (ADS)

    Ricci, Roberto; Fantoni, Roberta; Ferri de Collibus, Mario; Fornetti, Giorgio G.; Guarneri, Massimiliano; Poggi, Claudio

    2003-10-01

    A high resolution Amplitude Modulated Laser Radar (AM-LR) sensor has recently been developed, aimed at accurately reconstructing 3D digital models of real targets, either single objects or complex scenes. The sensor sounding beam can be swept linearly across the object or circularly around it, by placing the object on a controlled rotating platform, enabling to obtain respectively linear and cylindrical range maps. Both amplitude and phase shift of the modulating wave of back-scattered light are collected and processed, providing respectively a shade-free, high resolution, photographic-like picture and accurate range data in the form of a range image. The resolution of range measurements depends mainly on the laser modulation frequency, provided that the power of the backscattered light reaching the detector is at least a few nW (current best performances are ~100 μm). The complete object surface can be reconstructed from the sampled points by using specifically developed software tools. The system has been successfully applied to scan different types of real surfaces (stone, wood, alloys, bones), with relevant applications in different fields, ranging from industrial machining to medical diagnostics, to vision in hostile environments. Examples of artwork reconstructed models (pottery, marble statues) are presented and the relevance of this technology for reverse engineering applied to cultural heritage conservation and restoration are discussed. Final 3D models can be passed to numeric control machines for rapid-prototyping, exported in standard formats for CAD/CAM purposes and made available on the Internet by adopting a virtual museum paradigm, thus possibly enabling specialists to perform remote inspections on high resolution digital reproductions of hardly accessible masterpieces.

  12. Low-Cost 3D Laser Scanning in Air or Water Using Self-Calibrating Structured Light

    NASA Astrophysics Data System (ADS)

    Bleier, M.; Nüchter, A.

    2017-02-01

    In-situ calibration of structured light scanners in underwater environments is time-consuming and complicated. This paper presents a self-calibrating line laser scanning system, which enables the creation of dense 3D models with a single fixed camera and a freely moving hand-held cross line laser projector. The proposed approach exploits geometric constraints, such as coplanarities, to recover the depth information and is applicable without any prior knowledge of the position and orientation of the laser projector. By employing an off-the-shelf underwater camera and a waterproof housing with high power line lasers an affordable 3D scanning solution can be built. In experiments the performance of the proposed technique is studied and compared with 3D reconstruction using explicit calibration. We demonstrate that the scanning system can be applied to above-the-water as well as underwater scenes.

  13. Examination of heterogeneous crossing sequences between toner and rollerball pen strokes by digital microscopy and 3-D laser profilometry.

    PubMed

    Montani, Isabelle; Mazzella, Williams; Guichard, Marion; Marquis, Raymond

    2012-07-01

    The determination of line crossing sequences between rollerball pens and laser printers presents difficulties that may not be overcome using traditional techniques. This research aimed to study the potential of digital microscopy and 3-D laser profilometry to determine line crossing sequences between a toner and an aqueous ink line. Different paper types, rollerball pens, and writing pressure were tested. Correct opinions of the sequence were given for all case scenarios, using both techniques. When the toner was printed before the ink, a light reflection was observed in all crossing specimens, while this was never observed in the other sequence types. The 3-D laser profilometry, more time-consuming, presented the main advantage of providing quantitative results. The findings confirm the potential of the 3-D laser profilometry and demonstrate the efficiency of digital microscopy as a new technique for determining the sequence of line crossings involving rollerball pen ink and toner.

  14. Thin film passivation of laser generated 3D micro patterns in lithium manganese oxide cathodes

    NASA Astrophysics Data System (ADS)

    Pröll, J.; Kohler, R.; Bruns, M.; Oberst, V.; Weidler, P. G.; Heißler, S.; Kübel, C.; Scherer, T.; Prang, R.; Seifert, H. J.; Pfleging, W.

    2013-03-01

    The increasing need for long-life lithium-ion batteries requires the further development of electrode materials. Especially on the cathode side new materials or material composites are needed to increase the cycle lifetime. On the one hand, spinel-type lithium manganese oxide is a promising candidate to be used as cathode material due to its non-toxicity, low cost and good thermal stability. On the other hand, the spinel structure suffers from change in the oxidation state of manganese during cycling which is also accompanied by loss of active material into the liquid electrolyte. The general trend is to enhance the active surface area of the cathode in order to increase lithium-ion mobility through the electrode/electrolyte interface, while an enhanced surface area will also promote chemical degradation. In this work, laser microstructuring of lithium manganese oxide thin films was applied in a first step to increase the active surface area. This was done by using 248 nm excimer laser radiation and chromium/quartz mask imaging techniques. In a second step, high power diode laser-annealing operating at a wavelength of 940 nm was used for forming a cubic spinel-like battery phase. This was verified by means of Raman spectroscopy and cyclic voltammetric measurements. In a last step, the laser patterned thin films were coated with indium tin oxide (ITO) layers with a thickness of 10 nm to 50 nm. The influence of the 3D surface topography as well as the ITO thickness on the electrochemical performance was studied by cyclic voltammetry. Post-mortem studies were carried out by using scanning electron microscopy and focused ion beam analysis.

  15. Nondestructive Sectioning Of Fixed And Living Specimens Using A Confocal Scanning Laser Fluorescence Microscope: Microtomoscopy

    NASA Astrophysics Data System (ADS)

    Stelzer, Ernst H...; Wijnaendts-Van-Resandt, Roelof W.

    1987-08-01

    Modern molecular biologists and in particular cell biologists have a large set of experimental tools at their disposal. Immunocytochemistry, fluorescence labels, and microscopy are only subsets of the entire spectrum of methods. Depending on the fields in which biologists work a lot of results are obtained with classical biochemistry, gel electrophoresis and blotting techniques. Gathering morphological data may not be the least important task, but will in many cases be considered only after all other methods have failed. With the advent of video microscopes and the availability of high speed image processing devices, microscopy can also be used for quantitation. Confocal scanning laser fluorescence microscopy (Ft-CSCM) [Cox 1984] is in fact another technique or method that is entering the rapidly developing field of quantitative microscopy. It is therefore very important to understand the physical properties of the CSCLM in detail and to compare a confocal microscope not only with other confocal microscopes, but also with all the other techniques and methods. The confocal microscope has to find its particular application and it should be understood that it will replace neither conventional microscopy, nor video microscopy, nor electron microscopy. It will not be used for every application and every type of investigation. The CSCM has to find its niche in the laboratories and this paper will present two applications in which it proves its usefulness.

  16. Applications of Tunable Lasers to Laser Radar and 3D Imaging.

    DTIC Science & Technology

    2007-11-02

    The resulting form for U(z) is elliptical in shape: U(z) = &nf(a) cot2a^a2 sin2a - z2 for |z|<|ösina| . (21) This result is intuitive because...the range-resolved laser radar cross section of a disk is proportional to the length of the straight-line integration path, which varies elliptically ...autocorrelation functions of real quantities are even functions, the replicated U(z) curves on either side of the origin are mirror images of each other. If the

  17. Comparison between 3D model of Pisciarelli area (Campi Flegrei caldera) through Terrestrial Laser Scanner

    NASA Astrophysics Data System (ADS)

    Caputo, Teresa; Somma, Renato; Marino, Ermanno; Terracciano, Rosario; Troise, Claudia; De Natale, Giuseppe

    2016-04-01

    The volcanic/geothermal area of Pisciarelli is located within Campi Flegrei caldera .This last is a densely populated area, including the Pozzuoli town and bordering the western side of the Naples city, this causes a high vulnerability and consequently a high volcanic risk. In the recent decades this area has experienced minor ground uplift episodes accompanied by low magnitude seismicity and by strong intensification of degassing activity in particular localized at Pisciarelli area. We present the results of the Terrestrial Laser Scanner (TLS), using a Reigl VZ1000®, analysis of Pisciarelli area performed in June 2013 and the comparison with the data acquired later in March 2014. We apply the TLS technique based on Time of Flight (TOF) method in order to define an accurate 3D digital model for detailed analysis of this area performing numerous scans from different points of view in the area. In this ways was ensured a good coverage of the whole investigated area in order to avoid shaded portion due to the high soil degassing activity. Such fact limits the capacity of laser penetration is caused by wavelength near infrared range. For each survey was obtained a Digital Terrain Model (DTM) from the reconstructed data and both were compared. In particular, we have identified two "critical" areas of interest that will be monitored more frequently. These are: 1) in the lower part of the studied area a major fault line that bounding the Agnano caldera moderately NE-dipping; 2) in the upper part of the study area a zone of depletion with its zone of accumulation. The DTM were georeferenced into the UTM-WGS84 reference frame. The aim of this work is to define a procedure to compare between 3D model applied to monitoring of this area. Also to evaluate of volumetric and morphologic changes and to recognizing unstable masses by comparison of 3D data. For this purpose other TLS surveys will be performed in the upcoming in this active volcanic/geothermal area.

  18. Laser Scanning Holographic Lithography for Flexible 3D Fabrication of Multi-Scale Integrated Nano-structures and Optical Biosensors.

    PubMed

    Yuan, Liang Leon; Herman, Peter R

    2016-02-29

    Three-dimensional (3D) periodic nanostructures underpin a promising research direction on the frontiers of nanoscience and technology to generate advanced materials for exploiting novel photonic crystal (PC) and nanofluidic functionalities. However, formation of uniform and defect-free 3D periodic structures over large areas that can further integrate into multifunctional devices has remained a major challenge. Here, we introduce a laser scanning holographic method for 3D exposure in thick photoresist that combines the unique advantages of large area 3D holographic interference lithography (HIL) with the flexible patterning of laser direct writing to form both micro- and nano-structures in a single exposure step. Phase mask interference patterns accumulated over multiple overlapping scans are shown to stitch seamlessly and form uniform 3D nanostructure with beam size scaled to small 200 μm diameter. In this way, laser scanning is presented as a facile means to embed 3D PC structure within microfluidic channels for integration into an optofluidic lab-on-chip, demonstrating a new laser HIL writing approach for creating multi-scale integrated microsystems.

  19. Laser Scanning Holographic Lithography for Flexible 3D Fabrication of Multi-Scale Integrated Nano-structures and Optical Biosensors

    NASA Astrophysics Data System (ADS)

    Yuan, Liang (Leon); Herman, Peter R.

    2016-02-01

    Three-dimensional (3D) periodic nanostructures underpin a promising research direction on the frontiers of nanoscience and technology to generate advanced materials for exploiting novel photonic crystal (PC) and nanofluidic functionalities. However, formation of uniform and defect-free 3D periodic structures over large areas that can further integrate into multifunctional devices has remained a major challenge. Here, we introduce a laser scanning holographic method for 3D exposure in thick photoresist that combines the unique advantages of large area 3D holographic interference lithography (HIL) with the flexible patterning of laser direct writing to form both micro- and nano-structures in a single exposure step. Phase mask interference patterns accumulated over multiple overlapping scans are shown to stitch seamlessly and form uniform 3D nanostructure with beam size scaled to small 200 μm diameter. In this way, laser scanning is presented as a facile means to embed 3D PC structure within microfluidic channels for integration into an optofluidic lab-on-chip, demonstrating a new laser HIL writing approach for creating multi-scale integrated microsystems.

  20. Laser Scanning Holographic Lithography for Flexible 3D Fabrication of Multi-Scale Integrated Nano-structures and Optical Biosensors

    PubMed Central

    Yuan, Liang (Leon); Herman, Peter R.

    2016-01-01

    Three-dimensional (3D) periodic nanostructures underpin a promising research direction on the frontiers of nanoscience and technology to generate advanced materials for exploiting novel photonic crystal (PC) and nanofluidic functionalities. However, formation of uniform and defect-free 3D periodic structures over large areas that can further integrate into multifunctional devices has remained a major challenge. Here, we introduce a laser scanning holographic method for 3D exposure in thick photoresist that combines the unique advantages of large area 3D holographic interference lithography (HIL) with the flexible patterning of laser direct writing to form both micro- and nano-structures in a single exposure step. Phase mask interference patterns accumulated over multiple overlapping scans are shown to stitch seamlessly and form uniform 3D nanostructure with beam size scaled to small 200 μm diameter. In this way, laser scanning is presented as a facile means to embed 3D PC structure within microfluidic channels for integration into an optofluidic lab-on-chip, demonstrating a new laser HIL writing approach for creating multi-scale integrated microsystems. PMID:26922872

  1. Make or Buy: Cost Impacts of Additive Manufacturing, 3D Laser Scanning Technology, and Collaborative Product Lifecycle Management on Ship Maintenance and Modernization

    DTIC Science & Technology

    2015-05-01

    1 Make or Buy: Cost Impacts of Additive Manufacturing , 3D Laser Scanning Technology, and Collaborative Product Lifecycle Management on Ship...DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Make or Buy: Cost Impacts of Additive Manufacturing , 3D Laser Scanning Technology...management during operations 4 Potential Technology 3: Additive Manufacturing (“3D Printing”) 5 • 3D design/image (e.g. from 3D LS) of final part

  2. Laser-induced cartilage damage: an ex-vivo model using confocal microscopy

    NASA Astrophysics Data System (ADS)

    Frenz, Martin; Zueger, Benno J.; Monin, D.; Weiler, C.; Mainil-Varlet, P. M.; Weber, Heinz P.; Schaffner, Thomas

    1999-06-01

    Although there is an increasing popularity of lasers in orthopedic surgery, there is a growing concern about negative side effects of this therapy e.g. prolonged restitution time, radiation damage to adjacent cartilage or depth effects like bone necrosis. Despite case reports and experimental investigations over the last few years little is known about the extent of acute cartilage damage induced by different lasers types and energies. Histological examination offers only limited insights in cell viability and metabolism. Ho:YAG and Er:YAG lasers emitting at 2.1 micrometer and 2.94 micrometer, respectively, are ideally suited for tissue treatment because these wavelengths are strongly absorbed in water. The Purpose of the present study is to evaluate the effect of laser type and energy on chondrocyte viability in an ex vivo model. Free running Er:YAG (E equals 100 and 150 mJ) and Ho:YAG (E equals 500 and 800 mJ) lasers were used at different energy levels using a fixed pulse length of 400 microseconds. The energy was delivered at 8 Hz through optical fibers. Fresh bovine hyaline cartilage samples were mounted in a water bath at room temperature and the fiber was positioned at 30 degree and 180 degree angles relative to the tissue surface. After laser irradiation the samples were assessed by a life-dead cell viability test using a confocal microscope and by standard histology. Thermal damage was much deeper with Ho:YAG (up to 1800 micrometer) than with the Er:YAG laser (up to 70 micrometer). The cell viability test revealed a damage zone about twice the one determined by standard histology. Confocal microscopy is a powerful tool for assessing changes in tissue structure after laser treatment. In addition this technique allows to quantify these alterations without necessitating time consuming and expensive animal experiments.

  3. Laser scanning confocal microscope with programmable amplitude, phase, and polarization of the illumination beam.

    PubMed

    Boruah, B R; Neil, M A A

    2009-01-01

    We describe the design and construction of a laser scanning confocal microscope with programmable beam forming optics. The amplitude, phase, and polarization of the laser beam used in the microscope can be controlled in real time with the help of a liquid crystal spatial light modulator, acting as a computer generated hologram, in conjunction with a polarizing beam splitter and two right angled prisms assembly. Two scan mirrors, comprising an on-axis fast moving scan mirror for line scanning and an off-axis slow moving scan mirror for frame scanning, configured in a way to minimize the movement of the scanned beam over the pupil plane of the microscope objective, form the XY scan unit. The confocal system, that incorporates the programmable beam forming unit and the scan unit, has been implemented to image in both reflected and fluorescence light from the specimen. Efficiency of the system to programmably generate custom defined vector beams has been demonstrated by generating a bottle structured focal volume, which in fact is the overlap of two cross polarized beams, that can simultaneously improve both the lateral and axial resolutions if used as the de-excitation beam in a stimulated emission depletion confocal microscope.

  4. Multi-laser QED cascades in 2D and 3D geometry

    NASA Astrophysics Data System (ADS)

    Vranic, Marija; Grismayer, Thomas; Fonseca, Ricardo A.; Silva, Luis O.

    2015-11-01

    Studying the plasma dynamics in the presence of extreme laser fields requires taking into account physics beyond classical electrodynamics. Pair production seeded by an electron has a lowest threshold among the first quantum mechanisms that appear as the intensity increases, which makes it relevant for the future experiments planned at ELI and other facilities. We have included the two-step pair production process (non linear Compton scattering + Breit-Wheeler) in a massively parallel PIC code (Osiris 2.0 framework) via a Monte Carlo module. With this approach, we take self-consistently into account the interaction of the intense fields with the generated pair plasma. We have also developed a macroparticle merging algorithm that reduces the number of macroparticles in the simulations, while conserving local particle distributions. This algorithm is crucial for simulating scenarios where a large number of pairs are being created, such as QED cascades. We present 2D and 3D PIC-QED study of pair cascades induced with multiple laser pulses. The polarization dependence is discussed, together with the properties of the emitted radiation and experimental signatures. Supported by PRACE and ERC-2010-AdG Grant 267841.

  5. Development of 3D functionally graded models by laser-assisted coaxial powder injection

    NASA Astrophysics Data System (ADS)

    Yakovlev, Artem; Bertrand, Ph.; Smurov, Igor Y.

    2004-04-01

    Relatively new method of producing 3D objects with Functionally Graded Material (FGM) structure is realized by coaxial powder injection with variable composition into the zone of laser beam action. The desired 3-dimensional material distribution is realized by repetitive deposition process. Theoretical analysis and experimental results show essential role of radiation mode and powder granularity as optimization parameters. Applied laser sources are continuous wave Nd:YAG(HAAS 2006D, 2kW), pulse-periodic Nd:YAG(HAAS HL304P, avg. power 300 W), quazi-cw CO2 (Rofin-Sinar, 300 W). Among applied materials are nanostructured WC/Co, CuSn, Stainless steel 316L, 430L, Co-base alloy, nanostructured FeCu, etc. The originality of obtained results is that different gradient types are produced "in situ" and combined within one sample: smooth, sharp or multilayered gradients. The number of samples is produced and examined with metallographical and SEM analysis. The minimal spatial gradient resolution (transition zone between two different materials) is starting from 10 microns and can be varied in a wide range; the surface roughness depends from powder granularity, best value of Ra is about 5 μm, microhardness of differet zones of samples is varied from 120 to 450 HV. The achieved geometry spatial resolution is 200 μm.

  6. 3D Functional Elements Deep Inside Silicon with Nonlinear Laser Lithography

    NASA Astrophysics Data System (ADS)

    Tokel, Onur; Turnali, Ahmet; Ergecen, Emre; Pavlov, Ihor; Ilday, Fatih Omer

    Functional optical and electrical elements fabricated on silicon (Si) constitute fundamental building blocks of electronics and Si-photonics. However, since the highly successful established lithography are geared towards surface processing, elements embedded inside Si simply do not exist. Here, we present a novel direct-laser writing method for positioning buried functional elements inside Si wafers. This new phenomenon is distinct from previous work, in that the surface of Si is not modified. By exploiting nonlinear interactions of a focused laser, permanent refractive index changes are induced inside Si. The imprinted index contrast is then used to demonstrate a plethora of functional elements and capabilities embedded inside Si. In particular, we demonstrate the first functional optical element inside Si, the first information-storage capability inside Si, creation of high-resolution subsurface holograms, buried multilevel structures, and complex 3D architectures in Si, none of which is currently possible with other methods. This new approach complements available techniques by taking advantage of the real estate under Si, and therefore can pave the way for creating entirely new multilevel devices through electronic-photonic integration.

  7. EEG-MRI co-registration and sensor labeling using a 3D laser scanner.

    PubMed

    Koessler, L; Cecchin, T; Caspary, O; Benhadid, A; Vespignani, H; Maillard, L

    2011-03-01

    This paper deals with the co-registration of an MRI scan with EEG sensors. We set out to evaluate the effectiveness of a 3D handheld laser scanner, a device that is not widely used for co-registration, applying a semi-automatic procedure that also labels EEG sensors. The scanner acquired the sensors' positions and the face shape, and the scalp mesh was obtained from the MRI scan. A pre-alignment step, using the position of three fiducial landmarks, provided an initial value for co-registration, and the sensors were automatically labeled. Co-registration was then performed using an iterative closest point algorithm applied to the face shape. The procedure was conducted on five subjects with two scans of EEG sensors and one MRI scan each. The mean time for the digitization of the 64 sensors and three landmarks was 53 s. The average scanning time for the face shape was 2 min 6 s for an average number of 5,263 points. The mean residual error of the sensors co-registration was 2.11 mm. These results suggest that the laser scanner associated with an efficient co-registration and sensor labeling algorithm is sufficiently accurate, fast and user-friendly for longitudinal and retrospective brain sources imaging studies.

  8. Comparison of simulated and experimental 3D laser images using a GmAPD array: application to long range detection

    NASA Astrophysics Data System (ADS)

    Coyac, Antoine; Riviere, Nicolas; Hespel, Laurent; Briottet, Xavier

    2016-05-01

    In this paper, we show the feasibility and the benefit to use a Geiger-mode Avalanche Photo-Diode (GmAPD) array for long range detection, up to several kilometers. A simulation of a Geiger detection sensor is described, which is a part of our end-to-end laser simulator, to generate simulated 3D laser images from synthetic scenes. Resulting 3D point clouds have been compared to experimental acquisitions, performed with our GmAPD 3D camera on similar scenarios. An operational case of long range detection is presented: a copper cable outstretched above the ground, 1 kilometer away the experimental system and with a horizontal line-of-sight (LOS). The detection of such a small object from long distance observation strongly suggests that GmAPD focal plane arrays could be easily used for real-time 3D mapping or surveillance applications from airborne platforms, with good spatial and temporal resolutions.

  9. In vivo observation of papillae of the human tongue using confocal laser scanning microscopy.

    PubMed

    Just, Tino; Stave, Joachim; Pau, Hans Wilhelm; Guthoff, Rudolf

    2005-01-01

    The aim of this investigation was to visualize the epithelial structures of the tongue using confocal laser scanning microscopy (LSM). The human tongue epithelium of 28 healthy subjects, aged 21-67 years, mean age 38 years, 14 women and 14 men, was examined in vivo by LSM. Using LSM, a combination of the Heidelberg Retina Tomograph HRT II and the Rostock Cornea Module, up to 800-fold magnifications were obtained. On the tongue surface both filiform and fungiform papillae and their taste pores were easily identified. The epithelium of the tongue with its subcellular structures could be observed up to a depth of 50 microm, cellular structures up to 150 microm and subepithelial vessels up to 300 microm. Additionally the papillary crests and blood flow were visible. Confocal LSM seems suitable for noninvasive in vivo examination of the tongue. The hydraulic z scan, the manual start setting and the measurement of the depth allow a clear classification of the observed structures.

  10. Active segmentation of 3D axonal images.

    PubMed

    Muralidhar, Gautam S; Gopinath, Ajay; Bovik, Alan C; Ben-Yakar, Adela

    2012-01-01

    We present an active contour framework for segmenting neuronal axons on 3D confocal microscopy data. Our work is motivated by the need to conduct high throughput experiments involving microfluidic devices and femtosecond lasers to study the genetic mechanisms behind nerve regeneration and repair. While most of the applications for active contours have focused on segmenting closed regions in 2D medical and natural images, there haven't been many applications that have focused on segmenting open-ended curvilinear structures in 2D or higher dimensions. The active contour framework we present here ties together a well known 2D active contour model [5] along with the physics of projection imaging geometry to yield a segmented axon in 3D. Qualitative results illustrate the promise of our approach for segmenting neruonal axons on 3D confocal microscopy data.

  11. X-Ray and Optical Videography for 3D Measurement of Capillary and Melt Pool Geometry in Laser Welding

    NASA Astrophysics Data System (ADS)

    Boley, M.; Abt, F.; Weber, R.; Graf, T.

    This paper describes a method to reconstruct the 3D shape of the melt pool and the capillary of a laser keyhole welding process. Three different diagnostic methods, including X-Ray and optical videography as well as metallographic cross sections are combined to gain the three dimensional data of the solidus-liquidus-surface. A detailed description of the experimental setup and a discussion of different methods to combine the 2D data sets of the three different diagnostic methods to a 3D-model will be given. The result will be a static 3D description of the welding process.

  12. Low-power laser effects at the single-cell level: a confocal microscopy study

    NASA Astrophysics Data System (ADS)

    Alexandratou, Eleni; Yova, Dido M.; Atlamazoglou, Vassilis; Handris, Panagiotis; Kletsas, Dimitris; Loukas, Spyros

    2000-11-01

    Confocal microscopy was used for irradiation and observation of the same area of interest, allowing the imaging of low power laser effects in subcellular components and functions, at the single cell level. Coverslips cultures of human fetal foreskin fibroblasts (HFFF2) were placed in a small incubation chamber for in vivo microscopic observation. Cells were stimulated by the 647 nm line of the Argon- Krypton laser of the confocal microscope (0.1 mW/cm2). Membrane permeability, mitochondrial membrane potential ((delta) Psim), intracellular pHi, calcium alterations and nuclear chromatin accessibility were monitored, at different times after irradiation, using specific fluorescent vital probes. Images were stored to the computer and quantitative evaluation was performed using image- processing software. After irradiation, influx and efflux of the appropriate dyes monitored changes in cell membrane permeability. Laser irradiation caused alkalizatoin of the cytosolic pHi and increase of the mitochondrial membrane potential ((delta) Psim). Temporary global Ca2+ responses were also observed. No such effects were noted in microscopic fields other than the irradiated ones. No toxic effects were observed, during time course of the experiment.

  13. The use of custom 3D printed stereotactic frames for laser interstitial thermal ablation: technical note.

    PubMed

    Brandmeir, Nicholas J; McInerney, James; Zacharia, Brad E

    2016-10-01

    Over the last several years, laser interstitial thermotherapy (LITT) has gained wide acceptance for the treatment of a myriad of cranial lesions. A wide variety of techniques for placement of the laser fiber have been reported with a spectrum of perceived benefits and drawbacks. The authors present the first report of a customized 3D printed stereotactic frame for LITT. Approximately 1 week prior to surgery, 3-4 skull fiducials were placed after each of 5 patients received a local anesthetic as an outpatient. Radiographs with these fiducials were then used to create a trajectory to the lesion that would be treated with LITT. After the plan was completed, software was used to render a customized frame. On the day of surgery, the frame was attached to the implanted skull fiducials and the LITT catheter was placed. This procedure was carried out in 5 consecutive patients. In 2 patients, a needle biopsy was also performed. Intraoperative and postoperative imaging studies confirmed the accurate placement of the LITT catheter and the lesion created. Mean operating room time for all patients was 45 minutes but only 26 minutes when excluding the cases in which a biopsy was performed. To the best of the authors' knowledge, this is the first report of the use of a specific system, the STarFix microTargeting system, for use with LITT and brain biopsy. This system offers several advantages including fast operating times, extensive preoperative planning, no need for cranial fixation, and no need for frame or fiducial placement on the day of surgery. The accuracy of the system combined with these advantages may make this a preferred stereotactic method for LITT, especially in centers where LITT is performed in a diagnostic MRI suite.

  14. 3D-Laser-Scanning Technique Applied to Bulk Density Measurements of Apollo Lunar Samples

    NASA Technical Reports Server (NTRS)

    Macke, R. J.; Kent, J. J.; Kiefer, W. S.; Britt, D. T.

    2015-01-01

    In order to better interpret gravimetric data from orbiters such as GRAIL and LRO to understand the subsurface composition and structure of the lunar crust, it is import to have a reliable database of the density and porosity of lunar materials. To this end, we have been surveying these physical properties in both lunar meteorites and Apollo lunar samples. To measure porosity, both grain density and bulk density are required. For bulk density, our group has historically utilized sub-mm bead immersion techniques extensively, though several factors have made this technique problematic for our work with Apollo samples. Samples allocated for measurement are often smaller than optimal for the technique, leading to large error bars. Also, for some samples we were required to use pure alumina beads instead of our usual glass beads. The alumina beads were subject to undesirable static effects, producing unreliable results. Other investigators have tested the use of 3d laser scanners on meteorites for measuring bulk volumes. Early work, though promising, was plagued with difficulties including poor response on dark or reflective surfaces, difficulty reproducing sharp edges, and large processing time for producing shape models. Due to progress in technology, however, laser scanners have improved considerably in recent years. We tested this technique on 27 lunar samples in the Apollo collection using a scanner at NASA Johnson Space Center. We found it to be reliable and more precise than beads, with the added benefit that it involves no direct contact with the sample, enabling the study of particularly friable samples for which bead immersion is not possible

  15. Comparison of 3D representations depicting micro folds: overlapping imagery vs. time-of-flight laser scanner

    NASA Astrophysics Data System (ADS)

    Vaiopoulos, Aristidis D.; Georgopoulos, Andreas; Lozios, Stylianos G.

    2012-10-01

    A relatively new field of interest, which continuously gains grounds nowadays, is digital 3D modeling. However, the methodologies, the accuracy and the time and effort required to produce a high quality 3D model have been changing drastically the last few years. Whereas in the early days of digital 3D modeling, 3D models were only accessible to computer experts in animation, working many hours in expensive sophisticated software, today 3D modeling has become reasonably fast and convenient. On top of that, with online 3D modeling software, such as 123D Catch, nearly everyone can produce 3D models with minimum effort and at no cost. The only requirement is panoramic overlapping images, of the (still) objects the user wishes to model. This approach however, has limitations in the accuracy of the model. An objective of the study is to examine these limitations by assessing the accuracy of this 3D modeling methodology, with a Terrestrial Laser Scanner (TLS). Therefore, the scope of this study is to present and compare 3D models, produced with two different methods: 1) Traditional TLS method with the instrument ScanStation 2 by Leica and 2) Panoramic overlapping images obtained with DSLR camera and processed with 123D Catch free software. The main objective of the study is to evaluate advantages and disadvantages of the two 3D model producing methodologies. The area represented with the 3D models, features multi-scale folding in a cipollino marble formation. The most interesting part and most challenging to capture accurately, is an outcrop which includes vertically orientated micro folds. These micro folds have dimensions of a few centimeters while a relatively strong relief is evident between them (perhaps due to different material composition). The area of interest is located in Mt. Hymittos, Greece.

  16. Confocal laser scanning microscopy of porcine skin: implications for human wound healing studies

    PubMed Central

    VARDAXIS, N. J.; BRANS, T. A.; BOON, M. E.; KREIS, R. W.; MARRES, L. M.

    1997-01-01

    The structure of porcine skin as examined by light microscopy is reviewed and its similarities to and differences from human skin are highlighted. Special imaging techniques and staining procedures are described and their use in gathering morphological information in porcine skin is discussed. Confocal laser scanning microscopy (CLSM) was employed to examine the structure of porcine skin and the findings are presented as an adjunct to the information already available in the literature. It is concluded that CLSM provides valuable additional morphological information to material examined by conventional microscopy and is useful for wound healing studies in the porcine model. PMID:9183682

  17. Measurement of oxygen saturation in small retinal vessels with adaptive optics confocal scanning laser ophthalmoscope.

    PubMed

    Li, Hao; Lu, Jing; Shi, Guohua; Zhang, Yudong

    2011-11-01

    We have used an adaptive optics confocal scanning laser ophthalmoscope to assess oxygen saturation in small retinal vessels. Images of the vessels with a diameter smaller than 50 μm are recorded at oxygen sensitive and isosbestic wavelengths (680 and 796 nm, respectively). The vessel optical densities (ODs) are determined by a computer algorithm. Then, OD ratios (ODRs), which are inversely proportional to oxygen saturation, are calculated. The results show that arterial ODRs are significantly smaller than venous ODRs, indicating that oxygen saturation in the artery is higher than that in the vein. To the best of our knowledge, this is the first noninvasive measurement of oxygen saturation in small retinal vessels.

  18. Re-description of Craspodema reflectans (Nematoda, Cyatholaimidae) using confocal laser scanning microscopy.

    PubMed

    Semprucci, Federica; Burattini, Sabrina

    2015-06-12

    Craspodema reflectans, erected by Gerlach 1964, is here re-described from some specimens recently found in the Maldivian archipelago and the implication of the new findings for the taxonomy of the Craspodema genus is discussed. Accordingly, an emended diagnosis of Craspodema genus and C. reflectans species are proposed. New data are also provided with the aid of the confocal laser scanning microscopy, using the natural fluorescence of the nematodes. The approach described here lays new foundations for the study of Museum collection material and it may be decisive for capture of new morphological details.

  19. Ti-6Al-4V electron beam weld qualification using laser scanning confocal microscopy

    SciTech Connect

    Wanjara, P. . E-mail: priti.wanjara@cnrc-nrc.gc.ca; Brochu, M.; Jahazi, M.

    2005-03-15

    Processing conditions for manufacturing Ti-6Al-4V components by welding using an electron beam source are known to influence the transformation microstructure in the narrow fusion and heat-affected zones of the weld region. This work examined the effect of multiple-sequence welding on the characteristics of the transformed beta microstructure, using laser scanning confocal microscopy to resolve the Widmanstaetten alpha-beta structure in the fusion zone. The evolution in the alpha interlamellar spacing and plate thickness with processing was then related to microhardness measurements in the weld region.

  20. Characterization of microporous membranes using confocal scanning laser microscopy in fluorescence mode

    NASA Astrophysics Data System (ADS)

    Charcosset, C.; Bernengo, J.-C.

    2000-12-01

    Confocal Scanning Laser Microscopy (CSLM) in fluorescence mode was used to characterize microporous membranes. Two microfiltration membranes were investigated: a mixed ester (cellulose nitrate/cellulose acetate) 1.2 μm-rated membrane and a polycarbonate track-etched membrane with cylindrical pores of 2 μm diameter. Optical sections of the membranes stained with rhodamine and mounted in glycerol were performed at 1 μm intervals, from 0 to 10 μm. CSLM was found useful for microporous membrane characterization, as it gives some insight into bulk membrane morphology.

  1. Laser confocal measurement system for curvature radius of lenses based on grating ruler

    NASA Astrophysics Data System (ADS)

    Tian, Jiwei; Wang, Yun; Zhou, Nan; Zhao, Weirui; Zhao, Weiqian

    2015-02-01

    In the modern optical measurement field, the radius of curvature (ROC) is one of the fundamental parameters of optical lens. Its measurement accuracy directly affects the other optical parameters, such as focal length, aberration and so on, which significantly affect the overall performance of the optical system. To meet the demand of measurement instruments for radius of curvature (ROC) with high accuracy in the market, we develop a laser confocal radius measurement system with grating ruler. The system uses the peak point of the confocal intensity curve to precisely identify the cat-eye and confocal positions and then measure the distance between these two positions by using the grating ruler, thereby achieving the high-precision measurement for the ROC. The system has advantages of high focusing sensitivity and anti-environment disturbance ability. And the preliminary theoretical analysis and experiments show that the measuring repeatability can be up to 0.8 um, which can provide an effective way for the accurate measurement of ROC.

  2. The application of dermal papillary rings in dermatology by in vivo confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Xiang, W. Z.; Xu, A. E.; Xu, J.; Bi, Z. G.; Shang, Y. B.; Ren, Q. S.

    2010-08-01

    Confocal laser scanning microscopy (CLSM) allows noninvasive visualization of human skin in vivo, without needing to fix or section the tissue. Melanocytes and pigmented keratinocytes at the level of the basal layer form bright dermal papillary rings which are readily amenable to identify in confocal images. Our purpose was to explore the role of dermal papillary rings in assessment of lesion location, the diagnosis, differential diagnosis of lesions and assessment of therapeutic efficacy by in vivo CLSM. Seventy-one patients were imaged with the VivaScope 1500 reflectance confocal microscope provided by Lucid, Inc. The results indicate that dermal papillary rings can assess the location of lesion; the application of dermal papillary rings can provide diagnostic support and differential diagnosis for vitiligo, nevus depigmentosus, tinea versicolor, halo nevus, common nevi, and assess the therapeutic efficacy of NBUVB phototherapy plus topical 0.1 percent tacrolimus ointment for vitiligo. In conclusion, our findings indicate that the dermal papillary rings play an important role in the assessment the location of lesion, diagnosis, differential diagnosis of lesions and assessment of therapeutic efficacy by in vivo CLSM. CLSM may be a promising tool for noninvasive examination in dermatology. However, larger studies are needed to expand the application of dermal papillary rings in dermatology.

  3. Reliability of 3D laser-based anthropometry and comparison with classical anthropometry

    PubMed Central

    Kuehnapfel, Andreas; Ahnert, Peter; Loeffler, Markus; Broda, Anja; Scholz, Markus

    2016-01-01

    Anthropometric quantities are widely used in epidemiologic research as possible confounders, risk factors, or outcomes. 3D laser-based body scans (BS) allow evaluation of dozens of quantities in short time with minimal physical contact between observers and probands. The aim of this study was to compare BS with classical manual anthropometric (CA) assessments with respect to feasibility, reliability, and validity. We performed a study on 108 individuals with multiple measurements of BS and CA to estimate intra- and inter-rater reliabilities for both. We suggested BS equivalents of CA measurements and determined validity of BS considering CA the gold standard. Throughout the study, the overall concordance correlation coefficient (OCCC) was chosen as indicator of agreement. BS was slightly more time consuming but better accepted than CA. For CA, OCCCs for intra- and inter-rater reliability were greater than 0.8 for all nine quantities studied. For BS, 9 of 154 quantities showed reliabilities below 0.7. BS proxies for CA measurements showed good agreement (minimum OCCC > 0.77) after offset correction. Thigh length showed higher reliability in BS while upper arm length showed higher reliability in CA. Except for these issues, reliabilities of CA measurements and their BS equivalents were comparable. PMID:27225483

  4. 3D microscale laser dynamic forming: Multiscale modeling and experimental validation

    SciTech Connect

    Gao Huang; Cheng, Gary J.

    2011-05-15

    Microscale laser dynamic forming ({mu}LDF) shows great potential in fabricating robust and high-aspect-ratio metallic microcomponents. Experiments revealed that strain rate and sample size play important roles in determining the dynamic plasticity and final results of {mu}LDF. To further understand these effects, a multiscale modeling methodology is adopted to characterize the microscale dynamic plasticity considering the evolutions of nano-to-submicron dislocations avalanches under shock loading. In this methodology, 3D discrete dislocation dynamics simulations are implemented to derive the yield strength and the initial strain hardening dependence on size and strain rate. It is observed that there exist three dynamic stages during deformation process. The initial strain hardening rate in Stage II increases with strain rate. The mechanical threshold stress model, intrinsically equipped with strain-rate-dependent flow stress and initial hardening, is chosen and modified to incorporate size effect quantitatively. This scale-dependent model, implemented in abaqus/explicit, provides deformation depths and thickness variations in good agreement with experimental results in {mu}LDF.

  5. Optimization of 3D laser scanning speed by use of combined variable step

    NASA Astrophysics Data System (ADS)

    Garcia-Cruz, X. M.; Sergiyenko, O. Yu.; Tyrsa, Vera; Rivas-Lopez, M.; Hernandez-Balbuena, D.; Rodriguez-Quiñonez, J. C.; Basaca-Preciado, L. C.; Mercorelli, P.

    2014-03-01

    The problem of 3D TVS slow functioning caused by constant small scanning step becomes its solution in the presented research. It can be achieved by combined scanning step application for the fast search of n obstacles in unknown surroundings. Such a problem is of keynote importance in automatic robot navigation. To maintain a reasonable speed robots must detect dangerous obstacles as soon as possible, but all known scanners able to measure distances with sufficient accuracy are unable to do it in real time. So, the related technical task of the scanning with variable speed and precise digital mapping only for selected spatial sectors is under consideration. A wide range of simulations in MATLAB 7.12.0 of several variants of hypothetic scenes with variable n obstacles in each scene (including variation of shapes and sizes) and scanning with incremented angle value (0.6° up to 15°) is provided. The aim of such simulation was to detect which angular values of interval still permit getting the maximal information about obstacles without undesired time losses. Three of such local maximums were obtained in simulations and then rectified by application of neuronal network formalism (Levenberg-Marquradt Algorithm). The obtained results in its turn were applied to MET (Micro-Electro-mechanical Transmission) design for practical realization of variable combined step scanning on an experimental prototype of our previously known laser scanner.

  6. 3D laser measurements of bare and shod feet during walking.

    PubMed

    Novak, Boštjan; Možina, Janez; Jezeršek, Matija

    2014-01-01

    This article presents a new system for 3D foot-shape measurements during walking. It is based on the laser-triangulation, multiple-line-illumination and color-modulation techniques. It consists of a walking stage and four measuring modules that simultaneously acquire the foot shape from the top, bottom and side views. The measuring speed is 30 fps. Custom-developed software makes it possible to analyze the foot's dimensions at an arbitrary cross-section by means of the width, height, girth and section orientation. Six subjects were measured during bare and shod walking, and the bare foot and the outside dimensions of the footwear during the entire stance phase are presented. The relative measurement repeatability of a single subject is 0.5% for bare foot and 1% for shod foot. This means that it is possible to study the differences between various influences on the foot-shape dynamics, such as a bare/shod foot, different loading conditions and the shoe's stiffness condition.

  7. Automated analysis of barley organs using 3D laser scanning: an approach for high throughput phenotyping.

    PubMed

    Paulus, Stefan; Dupuis, Jan; Riedel, Sebastian; Kuhlmann, Heiner

    2014-07-15

    Due to the rise of laser scanning the 3D geometry of plant architecture is easy to acquire. Nevertheless, an automated interpretation and, finally, the segmentation into functional groups are still difficult to achieve. Two barley plants were scanned in a time course, and the organs were separated by applying a histogram-based classification algorithm. The leaf organs were represented by meshing algorithms, while the stem organs were parameterized by a least-squares cylinder approximation. We introduced surface feature histograms with an accuracy of 96% for the separation of the barley organs, leaf and stem. This enables growth monitoring in a time course for barley plants. Its reliability was demonstrated by a comparison with manually fitted parameters with a correlation R(2) = 0:99 for the leaf area and R(2) = 0:98 for the cumulated stem height. A proof of concept has been given for its applicability for the detection of water stress in barley, where the extension growth of an irrigated and a non-irrigated plant has been monitored.

  8. Concomitant use of Congo red staining and confocal laser scanning microscopy to detect amyloidosis in oral biopsy: A clinicopathological study of 16 patients.

    PubMed

    Scivetti, Michele; Favia, Gianfranco; Fatone, Laura; Maiorano, Eugenio; Crincoli, Vito

    2016-01-01

    Twenty oral biopsies from 16 patients were analyzed both by traditional microscopy and by confocal laser scanning microscopy. Using conventional histopathological techniques, the diagnosis of amyloidosis was confirmed only in 15 biopsies. Using confocal laser scanning microscopy, amyloid deposits were detected in all of the samples. The current study shows that confocal laser scanning analysis helps to identify minimal amyloid deposits that could be overlooked using traditional microscopy, thus raising the sensitivity of oral biopsy up to 100%.

  9. A 3-d laser scanning system and scan data processing method for the monitoring of tunnel deformations

    NASA Astrophysics Data System (ADS)

    Chmelina, Klaus; Jansa, Josef; Hesina, Gerd; Traxler, Christoph

    2012-11-01

    The paper presents the mobile multi-sensor system Orthos Plus for the monitoring and mapping of tunnel walls, a scan data processing method for the evaluation of 3-d tunnel wall displacements from subsequent wall scans and, finally, a virtual reality tool supporting the interpretation of data. The measuring system consists of a 3-d laser scanner, a motorised total station and a digital camera that are integrated on a light metal frame that is installed on a mobile platform. It has been designed to perform tunnel measurements most efficiently and to meet the special requirements of tunnels under construction. The evaluation of 3-d displacements is based on a 3-d matching algorithm that takes advantage of the particular conditions of tunnel (shotcrete) surfaces. The virtual reality tool allows viewing of data in a 3-d virtual reality tunnel model and their animation in time and space in order supports understanding in an optimal way. The measuring system Orthos Plus has been developed in the course of a national research project, the 3-d matching method in the frame of the Austrian Christian Doppler Laboratory Spatial Data from Laser Scanning and Remote Sensing and the VR tool in the Austrian COMET K1 Competence Center VRVis Center (www.vrvis.at).

  10. Evaluation of conjunctival inflammatory status by confocal scanning laser microscopy and conjunctival brush cytology in patients with atopic keratoconjunctivitis (AKC)

    PubMed Central

    Wakamatsu, Tais Hitomi; Okada, Naoko; Kojima, Takashi; Matsumoto, Yukihiro; Ibrahim, Osama M.A.; Adan, Enrique Sato; Fukagawa, Kazumi; Katakami, Chikako; Tsubota, Kazuo; Shimazaki, Jun; Fujishima, Hiroshi

    2009-01-01

    Purpose To elucidate the status of the conjunctival inflammation in atopic keratoconjunctivitis (AKC) using laser scanning confocal microscopy and compare the relevant findings with conjunctival brush cytology in a prospective controlled study. Methods Twenty eyes from 20 AKC patients as well as 16 eyes from 16 age and sex matched normal subjects were studied. The subjects underwent tear film break-up time (BUT), fluorescein and Rose Bengal staining of the ocular surface, conjunctival confocal microscopy, Schirmer test, and brush cytology. Brush cytology specimens and in vivo confocal microscopy scans underwent evaluation for inflammatory cell densities. Results Brush cytology specimens and in vivo confocal microscopy scans from AKC patients revealed significantly higher numbers of inflammatory cells (p<0.05). Conjunctival inflammatory cell density showed a negative correlation with tear stability and a positive correlation with vital staining scores and conjunctival injection grades. The extent of conjunctival inflammation assessed by in vivo confocal microscopy showed a strong positive linear correlation with the inflammation status evaluated by brush cytology. The corneal inflammatory cell density assessed by in vivo confocal microscopy showed a significant negative correlation with tear stability and a positive linear correlation with corneal fluorescein staining. Conclusions Confocal scanning laser microscopy is an efficient, noninvasive, and a promising tool for the quantitative assessment of conjunctival inflammation, a parameter of this new technology which correlated well with subjective and objective ocular surface clinical findings. PMID:19693288

  11. Estimating mass properties of dinosaurs using laser imaging and 3D computer modelling.

    PubMed

    Bates, Karl T; Manning, Phillip L; Hodgetts, David; Sellers, William I

    2009-01-01

    Body mass reconstructions of extinct vertebrates are most robust when complete to near-complete skeletons allow the reconstruction of either physical or digital models. Digital models are most efficient in terms of time and cost, and provide the facility to infinitely modify model properties non-destructively, such that sensitivity analyses can be conducted to quantify the effect of the many unknown parameters involved in reconstructions of extinct animals. In this study we use laser scanning (LiDAR) and computer modelling methods to create a range of 3D mass models of five specimens of non-avian dinosaur; two near-complete specimens of Tyrannosaurus rex, the most complete specimens of Acrocanthosaurus atokensis and Strutiomimum sedens, and a near-complete skeleton of a sub-adult Edmontosaurus annectens. LiDAR scanning allows a full mounted skeleton to be imaged resulting in a detailed 3D model in which each bone retains its spatial position and articulation. This provides a high resolution skeletal framework around which the body cavity and internal organs such as lungs and air sacs can be reconstructed. This has allowed calculation of body segment masses, centres of mass and moments or inertia for each animal. However, any soft tissue reconstruction of an extinct taxon inevitably represents a best estimate model with an unknown level of accuracy. We have therefore conducted an extensive sensitivity analysis in which the volumes of body segments and respiratory organs were varied in an attempt to constrain the likely maximum plausible range of mass parameters for each animal. Our results provide wide ranges in actual mass and inertial values, emphasizing the high level of uncertainty inevitable in such reconstructions. However, our sensitivity analysis consistently places the centre of mass well below and in front of hip joint in each animal, regardless of the chosen combination of body and respiratory structure volumes. These results emphasize that future

  12. Estimating Mass Properties of Dinosaurs Using Laser Imaging and 3D Computer Modelling

    PubMed Central

    Bates, Karl T.; Manning, Phillip L.; Hodgetts, David; Sellers, William I.

    2009-01-01

    Body mass reconstructions of extinct vertebrates are most robust when complete to near-complete skeletons allow the reconstruction of either physical or digital models. Digital models are most efficient in terms of time and cost, and provide the facility to infinitely modify model properties non-destructively, such that sensitivity analyses can be conducted to quantify the effect of the many unknown parameters involved in reconstructions of extinct animals. In this study we use laser scanning (LiDAR) and computer modelling methods to create a range of 3D mass models of five specimens of non-avian dinosaur; two near-complete specimens of Tyrannosaurus rex, the most complete specimens of Acrocanthosaurus atokensis and Strutiomimum sedens, and a near-complete skeleton of a sub-adult Edmontosaurus annectens. LiDAR scanning allows a full mounted skeleton to be imaged resulting in a detailed 3D model in which each bone retains its spatial position and articulation. This provides a high resolution skeletal framework around which the body cavity and internal organs such as lungs and air sacs can be reconstructed. This has allowed calculation of body segment masses, centres of mass and moments or inertia for each animal. However, any soft tissue reconstruction of an extinct taxon inevitably represents a best estimate model with an unknown level of accuracy. We have therefore conducted an extensive sensitivity analysis in which the volumes of body segments and respiratory organs were varied in an attempt to constrain the likely maximum plausible range of mass parameters for each animal. Our results provide wide ranges in actual mass and inertial values, emphasizing the high level of uncertainty inevitable in such reconstructions. However, our sensitivity analysis consistently places the centre of mass well below and in front of hip joint in each animal, regardless of the chosen combination of body and respiratory structure volumes. These results emphasize that future

  13. Ship-in-a-bottle integration by hybrid femtosecond laser technology for fabrication of true 3D biochips

    NASA Astrophysics Data System (ADS)

    Sima, Felix; Wu, Dong; Xu, Jian; Midorikawa, Katsumi; Sugioka, Koji

    2015-03-01

    We propose herein the "ship-in-a-bottle" integration of three-dimensional (3D) polymeric sinusoidal ridges inside photosensitive glass microfluidic channel by a hybrid subtractive - additive femtosecond laser processing method. It consists of Femtosecond Laser Assisted Wet Etching (FLAE) of a photosensitive Foturan glass followed by Two-Photon Polymerization (TPP) of a SU-8 negative epoxy-resin. Both subtractive and additive processes are carried out using the same set-up with the change of laser focusing objective only. A 522 nm wavelength of the second harmonic generation from an amplified femtosecond Yb-fiber laser (FCPA µJewel D-400, IMRA America, 1045 nm; pulse width 360 fs, repetition rate 200 kHz) was employed for irradiation. The new method allows lowering the size limit of 3D objects created inside channels to smaller details down to the dimensions of a cell, and improve the structure stability. Sinusoidal periodic patterns and ridges are of great use as base scaffolds for building up new structures on their top or for modulating cell migration, guidance and orientation while created interspaces can be exploited for microfluidic applications. The glass microchannel offers robustness and appropriate dynamic flow conditions for cellular studies while the integrated patterns are reducing the size of structure to the level of cells responsiveness. Taking advantage of the ability to directly fabricate 3D complex shapes, both glass channels and polymeric integrated patterns enable us to 3D spatially design biochips for specific applications.

  14. Combination of thermal extrusion printing and ultrafast laser fabrication for the manufacturing of 3D composite scaffolds

    NASA Astrophysics Data System (ADS)

    Balčiūnas, Evaldas; Lukoševičius, Laurynas; Mackevičiūtė, Dovilė; Rekštytė, Sima; Rutkūnas, Vygandas; Paipulas, Domas; Stankevičiūtė, Karolina; Baltriukienė, Daiva; Bukelskienė, Virginija; Piskarskas, Algis P.; Malinauskas, Mangirdas

    2014-03-01

    We present a novel approach to manufacturing 3D microstructured composite scaffolds for tissue engineering applications. A thermal extrusion 3D printer - a simple, low-cost tabletop device enabling rapid materialization of CAD models in plastics - was used to produce cm-scale microporous scaffolds out of polylactic acid (PLA). The fabricated objects were subsequently immersed in a photosensitive monomer solution and direct laser writing technique (DLW) was used to refine its inner structure by fabricating a fine mesh inside the previously produced scaffold. In addition, a composite material structure out of four different materials fabricated via DLW is presented. This technique, empowered by ultrafast lasers allows 3D structuring with high spatial resolution in a great variety of photosensitive materials. A composite scaffold made of distinct materials and periodicities is acquired after the development process used to wash out non-linked monomers. Another way to modify the 3D printed PLA surfaces was also demonstrated - ablation with femtosecond laser beam. Structure geometry on macro- to micro- scales could be finely tuned by combining these fabrication techniques. Such artificial 3D substrates could be used for cell growth or as biocompatible-biodegradable implants. To our best knowledge, this is the first experimental demonstration showing the creation of composite 3D scaffolds using convenient 3D printing combined with DLW. This combination of distinct material processing techniques enables rapid fabrication of diverse functional micro-featured and integrated devices. Hopefully, the proposed approach will find numerous applications in the field of tissue engineering, as well as in microelectromechanical systems, microfluidics, microoptics and others.

  15. Cardiac muscle organization revealed in 3-D by imaging whole-mount mouse hearts using two-photon fluorescence and confocal microscopy.

    PubMed

    Sivaguru, Mayandi; Fried, Glenn; Sivaguru, Barghav S; Sivaguru, Vignesh A; Lu, Xiaochen; Choi, Kyung Hwa; Saif, M Taher A; Lin, Brian; Sadayappan, Sakthivel

    2015-11-01

    The ability to image the entire adult mouse heart at high resolution in 3-D would provide enormous advantages in the study of heart disease. However, a technique for imaging nuclear/cellular detail as well as the overall structure of the entire heart in 3-D with minimal effort is lacking. To solve this problem, we modified the benzyl alcohol:benzyl benzoate (BABB) clearing technique by labeling mouse hearts with periodic acid Schiff (PAS) stain. We then imaged the hearts with a combination of two-photon fluorescence microscopy and automated tile-scan imaging/stitching. Utilizing the differential spectral properties of PAS, we could identify muscle and nuclear compartments in the heart. We were also able to visualize the differences between a 3-month-old normal mouse heart and a mouse heart that had undergone heart failure due to the expression of cardiac myosin binding protein-C (cMyBP-C) gene mutation (t/t). Using 2-D and 3-D morphometric analysis, we found that the t/t heart had anomalous ventricular shape, volume, and wall thickness, as well as a disrupted sarcomere pattern. We further validated our approach using decellularized hearts that had been cultured with 3T3 fibroblasts, which were tracked using a nuclear label. We were able to detect the 3T3 cells inside the decellularized intact heart tissue, achieving nuclear/cellular resolution in 3-D. The combination of labeling, clearing, and two-photon microscopy together with tiling eliminates laborious and time-consuming physical sectioning, alignment, and 3-D reconstruction.

  16. Development of confocal laser microscope system for examination of microscopic characteristics of radiophotoluminescence glass dosemeters.

    PubMed

    Maki, Daisuke; Ishii, Tetsuya; Sato, Fuminobu; Kato, Yushi; Yamamoto, Takayoshi; Iida, Toshiyuki

    2011-03-01

    A confocal laser microscope system was developed for the measurement of radiophotoluminescence (RPL) photons emitted from a minute alpha-ray-irradiated area in an RPL glass dosemeter. The system was composed mainly of an inverted-type microscope, an ultraviolet laser, an XY movable stage and photon-counting circuits. The photon-counting circuits were effective in the reduction of the background noise level in the measurement of RPL photons. The performance of this microscope system was examined by the observation of standard RPL glass samples irradiated using (241)Am alpha rays. The spatial resolution of this system was ∼ 3 μm, and with regard to the sensitivity of this system, a hit of more than four to five alpha rays in unit area produced enough amount of RPL photons to construct the image.

  17. A high-throughput comparative characterization of laser-induced soft tissue damage using 3D digital microscopy.

    PubMed

    Das, Debobrato; Reed, Stephanie; Klokkevold, Perry R; Wu, Benjamin M

    2013-02-01

    3D digital microscopy was used to develop a rapid alternative approach to quantify the effects of specific laser parameters on soft tissue ablation and charring in vitro without the use of conventional tissue processing techniques. Two diode lasers operating at 810 and 980 nm wavelengths were used to ablate three tissue types (bovine liver, turkey breast, and bovine muscle) at varying laser power (0.3, 1.0, and 2.0 W) and velocities (1-50 mm/s). Spectrophotometric analyses were performed on each tissue to determine tissue-specific absorption coefficients and were considered in creating wavelength-dependent energy attenuation models to evaluate minimum heat of tissue ablations. 3D surface contour profiles characterizing tissue damage revealed that ablation depth and tissue charring increased with laser power and decreased with lateral velocity independent of wavelength and tissue type. While bovine liver ablation and charring were statistically higher at 810 than 980 nm (p < 0.05), turkey breast and bovine muscle ablated and charred more at 980 than 810 nm (p < 0.05). Spectrophotometric analysis revealed that bovine liver tissue had a greater tissue-specific absorption coefficient at 810 than 980 nm, while turkey breast and bovine muscle had a larger absorption coefficient at 980 nm (p < 0.05). This rapid 3D microscopic analysis of robot-driven laser ablation yielded highly reproducible data that supported well-defined trends related to laser-tissue interactions and enabled high throughput characterization of many laser-tissue permutations. Since 3D microscopy quantifies entire lesions without altering the tissue specimens, conventional and immunohistologic techniques can be used, if desired, to further interrogate specific sections of the digitized lesions.

  18. EUS-Guided Needle-Based Confocal Laser Endomicroscopy: A Novel Technique With Emerging Applications.

    PubMed

    Bhutani, Manoop S; Koduru, Pramoda; Joshi, Virendra; Karstensen, John G; Saftoiu, Adrian; Vilmann, Peter; Giovannini, Marc

    2015-04-01

    Endoscopic ultrasound (EUS) has emerged as an excellent tool for imaging the gastrointestinal tract, as well as surrounding structures. EUS-guided fine-needle aspiration (EUS-FNA) has become the standard of care for the tissue sampling of a variety of masses and lymph nodes within and around the gut, providing further diagnostic and staging information. Confocal laser endomicroscopy (CLE) is a novel endoscopic method that enables imaging at a subcellular level of resolution during endoscopy, allowing up to 1000-fold magnification of tissue and providing an optical biopsy. A new procedure that has been developed in the past few years is needle-based confocal laser endomicroscopy (nCLE), which involves a mini-CLE probe that can be passed through a 1 9-gauge needle during EUS-FNA. This enables the real-time visualization of tissue at a microscopic level, with the potential to further improve the diagnostic accuracy of EUS-FNA. The device has been studied in animals as well as in humans, and the results so far have been promising. Recently, this method has also been used for the visualization of regulatory proteins and receptors in the pancreas, setting a cornerstone for nCLE in molecular imaging. The aim of this article is to review the role of EUS-guided nCLE in modern endoscopy and its implications in molecular imaging.

  19. Technique of laser confocal and Raman spectroscopy for living cell analysis

    NASA Astrophysics Data System (ADS)

    Meng, Xiaochen; Zhu, Lianqing

    2013-10-01

    Because of the shortcomings of the main methods used to analysis single cell, the need of single living cell analysis with no damage, unmarked and in situ dynamic multi-parameter measurement is urgent in the life sciences and biomedical advanced research field. And the method of for living cells analysis is proposed. The spectral pretreatment technology of living cell is the key work of laser confocal Raman spectroscopy. To study the spectrum processing methods for Raman spectrum on single living cell and develop the pre-process techniques to enhance the signal-to-noise ratio, sensitivity, and decrease the influence of fluorescence, elimination the cosmic rays was used to improve the spectrum. The classification, average and filtration of spectrum were applied to enhance signal-to-noise ratio. The fluorescence was depressed for quantity analysis or utilized for analysis by comparing the background and the spectrum. The results show that the proposed technique for laser confocal Raman spectrum of single cell can perform the sensitive and weak intensity peaks and reflect the information of molecules structures very well.

  20. Confocal Laser Microscope Scanning Applied To Three-Dimensional Studies Of Biological Specimens.

    NASA Astrophysics Data System (ADS)

    Franksson, Olof; Liljeborg, Anders; Carlsson, Kjell; Forsgren, Per-Ola

    1987-08-01

    The depth-discriminating property of confocal laser microscope scanners can be used to record the three-dimensional structure of specimens. A number of thin sections (approx. 1 μm thick) can be recorded by a repeated process of image scanning and refocusing of the microscope. We have used a confocal microscope scanner in a number of feasibility studies to investigate its possibilities and limitations. It has proved to be well suited for examining fluorescent specimens with a complicated three-dimensional structure, such as nerve cells. It has also been used to study orchid seeds, as well as cell colonies, greatly facilitating evaluation of such specimens. Scanning of the specimens is performed by a focused laser beam that is deflected by rotating mirrors, and the reflected or fluorescent light from the specimen is detected. The specimen thus remains stationary during image scanning, and is only moved stepwise in the vertical direction for refocusing between successive sections. The scanned images consist of 256*256 or 512*512 pixels, each pixel containing 8 bits of data. After a scanning session a large number of digital images, representing consecutive sections of the specimen, are stored on a disk memory. In a typical case 200 such 256*256 images are stored. To display and process this information in a meaningful way requires both appropriate software and a powerful computer. The computer used is a 32-bits minicomputer equipped with an array processor (FPS 100). The necessary software was developed at our department.

  1. Plasmon resonance and the imaging of metal-impregnated neurons with the laser scanning confocal microscope

    PubMed Central

    Thompson, Karen J; Harley, Cynthia M; Barthel, Grant M; Sanders, Mark A; Mesce, Karen A

    2015-01-01

    The staining of neurons with silver began in the 1800s, but until now the great resolving power of the laser scanning confocal microscope has not been utilized to capture the in-focus and three-dimensional cytoarchitecture of metal-impregnated cells. Here, we demonstrate how spectral confocal microscopy, typically reserved for fluorescent imaging, can be used to visualize metal-labeled tissues. This imaging does not involve the reflectance of metal particles, but rather the excitation of silver (or gold) nanoparticles and their putative surface plasmon resonance. To induce such resonance, silver or gold particles were excited with visible-wavelength laser lines (561 or 640 nm), and the maximal emission signal was collected at a shorter wavelength (i.e., higher energy state). Because the surface plasmon resonances of noble metal nanoparticles offer a superior optical signal and do not photobleach, our novel protocol holds enormous promise of a rebirth and further development of silver- and gold-based cell labeling protocols. DOI: http://dx.doi.org/10.7554/eLife.09388.001 PMID:26670545

  2. Cross-Sectional Shape of Rat Mesenteric Arterioles at Branching Studied by Confocal Laser Microscopy

    NASA Astrophysics Data System (ADS)

    Nakano, Atushi; Minamiyama, Motomu; Niimi, Hideyuki

    This study was aimed to investigate the cross-sectional shape of mesenteric arterioles at branching, using confocal laser microscopy. Wistar rats (8 weeks, male) were anesthetized with thiobutabarbital sodium. Blood flow and microvascular network in the mesentery were observed using video microscopy. The rat intestine with mesentery was extracted and the intestinal vasculature was perfused with Krebs-Ringer and then fixed with paraformaldehyde under a static pressure of 100mmHg. A section of mesentery was isolated from the intestine, and spread up to the in vivo geometry based on the intravital microscopic observation. The mesentery section was stained with tetramethyl rhodamine isothiocyanate (TRITC)-phalloidin. The samples were observed under a confocal laser microscope. The cross-sectional image was re-sliced to measure the cross-sectional area and major/minor axes of the best fitting ellipse. The aspect ratio was defined in terms of the minor/major diameter ratio. The extended focus image of mesenteric arterioles showed that the cross-sectional shape was not circular but elliptic-like. The cross-sectional area of the parent vessel decreased from proximal to distal positions. The mean aspect ratio of the parent vessel was approximately 0.5, while that of the branching vessel was approximately 0.8. The flattened shape and variation of the cross-sectional area of arterioles requires some correction of in vivo data of the two-dimensional mesenteric microvasculature obtained using intravital microscopy.

  3. Probe-based confocal laser endomicroscopy in head and neck malignancies: early preclinical experience

    NASA Astrophysics Data System (ADS)

    Englhard, Anna; Girschick, Susanne; Mack, Brigitte; Volgger, Veronika; Gires, Oliver; Conderman, Christian; Stepp, Herbert; Betz, Christian Stephan

    2013-06-01

    Background: Malignancies of the upper aerodigestive tract (UADT) are conventionally diagnosed by white light endoscopy, biopsy and histopathology. Probe-based Confocal Laser Endomicroscopy (pCLE) is a novel non-invasive technique which offers in vivo surface and sub-surface imaging of tissue. It produces pictures of cellular architecture comparable to histology without the need for biopsy. It has already been successfully used in different clinical subspecialties to help in the diagnosis and treatment planning of inflammatory and neoplastic diseases. PCLE needs to be used in combination with specific or non-specific contrast agents. In this study we evaluated the potential use of pCLE in combination with non-specific and specific contrast agents to distinguish between healthy mucosa and invasive carcinoma. Methods: Tissue samples from healthy mucosa and squamous cell carcinoma of the head and neck were taken during surgery. After topical application of three different contrast agents, samples were examined using different pCLE-probes and a Confocal Laser Scanning Microscope (CLSM). Images were then compared to the corresponding histological slides and cryosections. Results: Initial results show that pCLE in combination with fluorophores allows visualization of cellular and structural components. Imaging of different layers was possible using three distinct pCLEprobes. Conclusion: pCLE is a promising non-invasive technique that may be a useful adjunct in the evaluation, diagnosis and treatment planning of head and neck malignancies.

  4. Permanent 3D laser scanning system for an active landslide in Gresten (Austria)

    NASA Astrophysics Data System (ADS)

    Canli, Ekrem; Höfle, Bernhard; Hämmerle, Martin; Benni, Thiebes; Glade, Thomas

    2015-04-01

    Terrestrial laser scanners (TLS) have widely been used for high spatial resolution data acquisition of topographic features and geomorphic analyses. Existing applications encompass different landslides including rockfall, translational or rotational landslides, debris flow, but also coastal cliff erosion, braided river evolution or river bank erosion. The main advantages of TLS are (a) the high spatial sampling density of XYZ-measurements (e.g. 1 point every 2-3 mm at 10 m distance), particularly in comparison with the low data density monitoring techniques such as GNSS or total stations, (b) the millimeter accuracy and precision of the range measurement to centimeter accuracy of the final DEM, and (c) the highly dense area-wide scanning that enables to look through vegetation and to measure bare ground. One of its main constraints is the temporal resolution of acquired data due to labor costs and time requirements for field campaigns. Thus, repetition measurements are generally performed only episodically. However, for an increased scientific understanding of the processes as well as for early warning purposes, we present a novel permanent 3D monitoring setup to increase the temporal resolution of TLS measurements. This accounts for different potential monitoring deliverables such as volumetric calculations, spatio-temporal movement patterns, predictions and even alerting. This system was installed at the active Salcher landslide in Gresten (Austria) that is situated in the transition zone of the Gresten Klippenbelt (Helvetic) and the Flyschzone (Penninic). The characteristic lithofacies are the Gresten Beds of Early Jurassic age that are covered by a sequence of marly and silty beds with intercalated sandy limestones. Permanent data acquisition can be implemented into our workflow with any long-range TLS system offering fully automated capturing. We utilize an Optech ILRIS-3D scanner. The time interval between two scans is currently set to 24 hours, but can be

  5. 3D leaf water content mapping using terrestrial laser scanner backscatter intensity with radiometric correction

    NASA Astrophysics Data System (ADS)

    Zhu, Xi; Wang, Tiejun; Darvishzadeh, Roshanak; Skidmore, Andrew K.; Niemann, K. Olaf

    2015-12-01

    Leaf water content (LWC) plays an important role in agriculture and forestry management. It can be used to assess drought conditions and wildfire susceptibility. Terrestrial laser scanner (TLS) data have been widely used in forested environments for retrieving geometrically-based biophysical parameters. Recent studies have also shown the potential of using radiometric information (backscatter intensity) for estimating LWC. However, the usefulness of backscatter intensity data has been limited by leaf surface characteristics, and incidence angle effects. To explore the idea of using LiDAR intensity data to assess LWC we normalized (for both angular effects and leaf surface properties) shortwave infrared TLS data (1550 nm). A reflectance model describing both diffuse and specular reflectance was applied to remove strong specular backscatter intensity at a perpendicular angle. Leaves with different surface properties were collected from eight broadleaf plant species for modeling the relationship between LWC and backscatter intensity. Reference reflectors (Spectralon from Labsphere, Inc.) were used to build a look-up table to compensate for incidence angle effects. Results showed that before removing the specular influences, there was no significant correlation (R2 = 0.01, P > 0.05) between the backscatter intensity at a perpendicular angle and LWC. After the removal of the specular influences, a significant correlation emerged (R2 = 0.74, P < 0.05). The agreement between measured and TLS-derived LWC demonstrated a significant reduction of RMSE (root mean square error, from 0.008 to 0.003 g/cm2) after correcting for the incidence angle effect. We show that it is possible to use TLS to estimate LWC for selected broadleaved plants with an R2 of 0.76 (significance level α = 0.05) at leaf level. Further investigations of leaf surface and internal structure will likely result in improvements of 3D LWC mapping for studying physiology and ecology in vegetation.

  6. Fs-laser microstructuring of laser-printed LiMn2O4 electrodes for manufacturing of 3D microbatteries

    NASA Astrophysics Data System (ADS)

    Pröll, J.; Kim, H.; Mangang, M.; Seifert, H. J.; Piqué, A.; Pfleging, W.

    2014-03-01

    Lithium manganese oxide composite cathodes are realized by laser-printing. The printed cathode is a composite and consists of active powder, binder and conductive agents. Laser-printed cathodes are first calendered and then laser structured using femtosecond-laser radiation in order to form three-dimensional (3D) micro-grids in the cathode material. Three-dimensional micro-grids in calendered/laser structured cathodes exhibit improved discharge capacity retention at a 1 C discharging rate. Calendered but unstructured cathodes indicate the poorest cycling behavior at 1 C discharge. The improved capacity retention and the reduced degradation of calendered/structured cathodes can be attributed to both the increased electrical contact through calendering as well as shortened Li-ion pathways due to laser-induced 3D microgrids.

  7. Accuracy and precision of the three-dimensional assessment of the facial surface using a 3-D laser scanner.

    PubMed

    Kovacs, L; Zimmermann, A; Brockmann, G; Baurecht, H; Schwenzer-Zimmerer, K; Papadopulos, N A; Papadopoulos, M A; Sader, R; Biemer, E; Zeilhofer, H F

    2006-06-01

    Three-dimensional (3-D) recording of the surface of the human body or anatomical areas has gained importance in many medical specialties. Thus, it is important to determine scanner precision and accuracy in defined medical applications and to establish standards for the recording procedure. Here we evaluated the precision and accuracy of 3-D assessment of the facial area with the Minolta Vivid 910 3D Laser Scanner. We also investigated the influence of factors related to the recording procedure and the processing of scanner data on final results. These factors include lighting, alignment of scanner and object, the examiner, and the software used to convert measurements into virtual images. To assess scanner accuracy, we compared scanner data to those obtained by manual measurements on a dummy. Less than 7% of all results with the scanner method were outside a range of error of 2 mm when compared to corresponding reference measurements. Accuracy, thus, proved to be good enough to satisfy requirements for numerous clinical applications. Moreover, the experiments completed with the dummy yielded valuable information for optimizing recording parameters for best results. Thus, under defined conditions, precision and accuracy of surface models of the human face recorded with the Minolta Vivid 910 3D Scanner presumably can also be enhanced. Future studies will involve verification of our findings using test persons. The current findings indicate that the Minolta Vivid 910 3D Scanner might be used with benefit in medicine when recording the 3-D surface structures of the face.

  8. One-step direct-laser metal writing of sub-100 nm 3D silver nanostructures in a gelatin matrix

    NASA Astrophysics Data System (ADS)

    Kang, SeungYeon; Vora, Kevin; Mazur, Eric

    2015-03-01

    Developing an ability to fabricate high-resolution, 3D metal nanostructures in a stretchable 3D matrix is a critical step to realizing novel optoelectronic devices such as tunable bulk metal-dielectric optical devices and THz metamaterial devices that are not feasible with alternative techniques. We report a new chemistry method to fabricate high-resolution, 3D silver nanostructures using a femtosecond-laser direct metal writing technique. Previously, only fabrication of 3D polymeric structures or single-/few-layer metal structures was possible. Our method takes advantage of unique gelatin properties to overcome such previous limitations as limited freedom in 3D material design and short sample lifetime. We fabricate more than 15 layers of 3D silver nanostructures with a resolution of less than 100 nm in a stable dielectric matrix that is flexible and has high large transparency that is well-matched for potential applications in the optical and THz metamaterial regimes. This is a single-step process that does not require any further processing. This work will be of interest to those interested in fabrication methods that utilize nonlinear light-matter interactions and the realization of future metamaterials.

  9. A Pilot Study of In Vivo Confocal Laser Endomicroscopy of Upper Tract Urothelial Carcinoma

    PubMed Central

    Bui, Daniel; Mach, Kathleen E.; Zlatev, Dimitar V.; Rouse, Robert V.; Leppert, John T.

    2015-01-01

    Abstract Purpose: Tissue diagnosis of upper tract urothelial carcinoma (UTUC) is limited by variance in tumor sampling by standard ureteroscopic biopsy. Optical imaging technologies can potentially improve UTUC diagnosis, surveillance, and endoscopic treatment. We previously demonstrated in vivo optical biopsy of urothelial carcinoma of the bladder using confocal laser endomicroscopy (CLE). In this study, we evaluated a new 0.85-mm imaging probe in the upper urinary tract and demonstrated feasibility and compatibility with standard ureteroscopes to achieve in vivo optical biopsy of UTUC. Materials and Methods: Fourteen patients scheduled for ureteroscopy of suspected upper tract lesions or surveillance of UTUC were recruited. After intravenous (IV) administration of fluorescein, CLE was performed using a 0.85-mm-diameter imaging probe inserted through the working channel of standard ureteroscopes. Acquired confocal video sequences were reviewed and analyzed. A mosaicing algorithm was used to compile a series of images into a single larger composite image. Processed CLE images were compared with standard histopathologic analysis. Results: Optical biopsy of the UTUC using CLE was effectively achieved during standard ureteroscopy. There were no adverse events related to IV fluorescein administration or image acquisition. Confocal imaging of UTUC showed characteristic features similar to urothelial carcinoma of the bladder, including papillary structure, fibrovascular stalks, and pleomorphism. Lamina propria in normal areas of the renal pelvis and ureter was also identified. Conclusions: We report an initial feasibility of CLE of UTUC. Pending further clinical investigation, CLE may become a useful adjunct to ureteroscopic biopsy, endoscopic ablation, and surveillance of UTUC. PMID:26413927

  10. Roughness of biopores and cracks in Bt-horizons by confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Leue, Martin; Gerke, Horst H.

    2016-04-01

    During preferential flow events in structured soils, the movement of water and reactive solutes is mostly restricted to larger inter-aggregate pores, cracks, and biopores. The micro-topography of such macropores in terms of pore shapes, geometry, and roughness is crucial for describing the exchange of water and solutes between macropores and the soil matrix. The objective of this study was to determine the surface roughness of intact structural surfaces from the Bt-horizon of Luvisols by confocal laser scanning microscopy. For this purpose, samples with the structural surface types including cracks with and without clay-organic coatings from Bt-horizons developed on loess and glacial till were compared. The surface roughness of these structures was calculated in terms of three parameters from selected surface regions of 0.36 mm² determined with a confocal laser scanning microscope of the type Keyence VK-X100K. These data were evaluated in terms of the root-mean-squared roughness, Rq, the curvature, Rku, and the ratio between surface area and base area, RA. Values of Rq and RA were smaller for coated as compared to uncoated cracks and earthworm burrows of the Bt-horizons from both parent materials. The results indicated that the illuviation of clayey material led to a "smoothing" of the crack surfaces, which was similar for the coarser textured till-Bt and the finer-textured loess-Bt surfaces. The roughness indicated by Rq and RA values was only slightly smaller and that indicated by Rku slightly higher for the structural surfaces from the loess as compared to those from the glacial till. These results suggest a minor importance of the parent material on the roughness of structural surfaces in the Bt-horizon. The similarity of Rq, RA, and Rku values between surfaces of earthworm burrows and uncoated cracks did not confirm an expected smoothing effect of the burrow walls by the earthworm. In contrast to burrow walls, root channels from the loess-Bt were smoother

  11. Time-resolved fuel injector flow characterisation based on 3D laser Doppler vibrometry

    NASA Astrophysics Data System (ADS)

    Crua, Cyril; Heikal, Morgan R.

    2014-12-01

    Hydrodynamic turbulence and cavitation are known to play a significant role in high-pressure atomizers, but the small geometries and extreme operating conditions hinder the understanding of the flow’s characteristics. Diesel internal flow experiments are generally conducted using x-ray techniques or on transparent, and often enlarged, nozzles with different orifice geometries and surface roughness to those found in production injectors. In order to enable investigations of the fuel flow inside unmodified injectors, we have developed a new experimental approach to measure time-resolved vibration spectra of diesel nozzles using a 3D laser vibrometer. The technique we propose is based on the triangulation of the vibrometer and fuel pressure transducer signals, and enables the quantitative characterisation of quasi-cyclic internal flows without requiring modifications to the injector, the working fluid, or limiting the fuel injection pressure. The vibrometer, which uses the Doppler effect to measure the velocity of a vibrating object, was used to scan injector nozzle tips during the injection event. The data were processed using a discrete Fourier transform to provide time-resolved spectra for valve-closed-orifice, minisac and microsac nozzle geometries, and injection pressures ranging from 60 to 160 MPa, hence offering unprecedented insight into cyclic cavitation and internal mechanical dynamic processes. A peak was consistently found in the spectrograms between 6 and 7.5 kHz for all nozzles and injection pressures. Further evidence of a similar spectral peak was obtained from the fuel pressure transducer and a needle lift sensor mounted into the injector body. Evidence of propagation of the nozzle oscillations to the liquid sprays was obtained by recording high-speed videos of the near-nozzle diesel jet, and computing the fast Fourier transform for a number of pixel locations at the interface of the jets. This 6-7.5 kHz frequency peak is proposed to be the

  12. Real-time confocal imaging of trafficking of nestin-expressing multipotent stem cells in mouse whiskers in long-term 3-D histoculture.

    PubMed

    Duong, Jennifer; Mii, Sumiyuki; Uchugonova, Aisada; Liu, Fang; Moossa, A R; Hoffman, Robert M

    2012-05-01

    We have previously demonstrated that nestin-expressing multipotent hair follicle stem cells are located above the hair follicle bulge and can differentiate into neurons and other cell types in vitro. The nestin-expressing hair follicle stem cells promoted the recovery of pre-existing axons when they were transplanted to the severed sciatic nerve or injured spinal cord. We have also previously demonstrated that the whisker hair follicle contains nestin-expressing stem cells in the dermal papilla (DP) as well as in the bulge area (BA), but that their origin is in the BA. In the present study, we established the technique of long-term Gelfoam® histoculture of whiskers isolated from transgenic mice in which nestin drives green fluorescent protein (ND-GFP). Confocal imaging was used to monitor ND-GFP-expressing stem cells trafficking in real time between the BA and DP to determine the fate of the stem cells. It was observed over a 2-week period that the stem cells trafficked from the BA toward the DP area and extensively grew out onto Gelfoam® forming nerve-like structures. This new method of long-term histoculture of whiskers from ND-GFP mice will enable the extensive study of the behavior of nestin-expressing multipotent stem cells of the hair follicle.

  13. Spectral imaging technique for retinal perfusion detection using confocal scanning laser ophthalmoscopy.

    PubMed

    Rasta, Seyed Hossein; Manivannan, Ayyakkannu; Sharp, Peter F

    2012-11-01

    To evaluate retinal perfusion in the human eye, a dual-wavelength confocal scanning laser ophthalmoscope (cSLO) was developed that provides spectral imaging of the fundus using a combination of red (670 nm) and near-infrared (810 nm) wavelengths. The image of the ocular fundus was analyzed to find out if quantitative measurements of the reflectivity of tissue permit assessment of the oxygen perfusion of tissue. We explored problems that affect the reproducibility of patient measurements such as non-uniformity errors on the image. For the first time, an image processing technique was designed and used to minimize the errors of oxygen saturation measurements by illumination correction in retina wide field by increasing SNR. Retinal images were taken from healthy and diabetic retinopathy eyes using the cSLO with a confocal aperture of 100 μm. The ratio image (RI) of red/IR, as oxygen saturation (SO2) index, was calculated for normal eyes. The image correction technique improved the reproducibility of the measurements. Average RI intensity variation of healthy retina tissue was determined within a range of about 5.5%. The capability of the new technique to discriminate oxygenation levels of retinal artery and vein was successfully demonstrated and showed good promise in the diagnosis of the perfused retina.

  14. Spectral imaging technique for retinal perfusion detection using confocal scanning laser ophthalmoscopy

    NASA Astrophysics Data System (ADS)

    Rasta, Seyed Hossein; Manivannan, Ayyakkannu; Sharp, Peter F.

    2012-11-01

    To evaluate retinal perfusion in the human eye, a dual-wavelength confocal scanning laser ophthalmoscope (cSLO) was developed that provides spectral imaging of the fundus using a combination of red (670 nm) and near-infrared (810 nm) wavelengths. The image of the ocular fundus was analyzed to find out if quantitative measurements of the reflectivity of tissue permit assessment of the oxygen perfusion of tissue. We explored problems that affect the reproducibility of patient measurements such as non-uniformity errors on the image. For the first time, an image processing technique was designed and used to minimize the errors of oxygen saturation measurements by illumination correction in retina wide field by increasing SNR. Retinal images were taken from healthy and diabetic retinopathy eyes using the cSLO with a confocal aperture of 100 μm. The ratio image (RI) of red/IR, as oxygen saturation (SO2) index, was calculated for normal eyes. The image correction technique improved the reproducibility of the measurements. Average RI intensity variation of healthy retina tissue was determined within a range of about 5.5%. The capability of the new technique to discriminate oxygenation levels of retinal artery and vein was successfully demonstrated and showed good promise in the diagnosis of the perfused retina.

  15. Scanning a microhabitat: plant-microbe interactions revealed by confocal laser microscopy

    PubMed Central

    Cardinale, Massimiliano

    2014-01-01

    No plant or cryptogam exists in nature without microorganisms associated with its tissues. Plants as microbial hosts are puzzles of different microhabitats, each of them colonized by specifically adapted microbiomes. The interactions with such microorganisms have drastic effects on the host fitness. Since the last 20 years, the combination of microscopic tools and molecular approaches contributed to new insights into microbe-host interactions. Particularly, confocal laser scanning microscopy (CLSM) facilitated the exploration of microbial habitats and allowed the observation of host-associated microorganisms in situ with an unprecedented accuracy. Here I present an overview of the progresses made in the study of the interactions between microorganisms and plants or plant-like organisms, focusing on the role of CLSM for the understanding of their significance. I critically discuss risks of misinterpretation when procedures of CLSM are not properly optimized. I also review approaches for quantitative and statistical analyses of CLSM images, the combination with other molecular and microscopic methods, and suggest the re-evaluation of natural autofluorescence. In this review, technical aspects were coupled with scientific outcomes, to facilitate the readers in identifying possible CLSM applications in their research or to expand their existing potential. The scope of this review is to highlight the importance of confocal microscopy in the study of plant-microbe interactions and also to be an inspiration for integrating microscopy with molecular techniques in future researches of microbial ecology. PMID:24639675

  16. High resolution fundus imaging by confocal scanning laser ophthalmoscopy in the mouse.

    PubMed

    Paques, Michel; Simonutti, Manuel; Roux, Michel J; Picaud, Serge; Levavasseur, Etienne; Bellman, Caren; Sahel, José-Alain

    2006-04-01

    We evaluated fundus imaging using a modified confocal scanning laser ophthalmoscope (cSLO) in mice. Examinations were performed in conscious, untrained mice. The largest field of view measured 1,520 x 1,520 mu, with a significant interindividual variability, itself correlated to biometric variability. The composite field of view extended up to the ora serrata. The reflectance imaging associated light reflection from nerve fiber bundles and vessel walls, and absorption by hemoglobin and melanin. Light absorption by the pigment epithelium indeed increased the contrast of the nerve fiber layer, but impaired viewing of the choroid. Due to the confocal mode, fluorescence angiograms with clear separation of retinal and choroidal fluorescence could be obtained even in albino mice. Micrometric-scale transverse resolution and several planes of optical sectioning within the retina were obtained. This permitted for instance tridimensional, subcellular viewing of gfp-expressing retinal microglial cells in CX(3)CR1 mice. We concluded that cSLO is a promising tool for noninvasive, multimodal intravital microscopy of the fundus in the mouse.

  17. 3D digitization methods based on laser excitation and active triangulation: a comparison

    NASA Astrophysics Data System (ADS)

    Aubreton, Olivier; Mériaudeau, Fabrice; Truchetet, Frédéric

    2016-04-01

    3D reconstruction of surfaces is an important topic in computer vision and corresponds to a large field of applications: industrial inspection, reverse engineering, object recognition, biometry, archeology… Because of the large varieties of applications, one can find in the literature a lot of approaches which can be classified into two families: passive and active [1]. Certainly because of their reliability, active approaches, using imaging system with an additional controlled light source, seem to be the most commonly used in the industrial field. In this domain, the 3D digitization approach based on active 3D triangulation has had important developments during the last ten years [2] and seems to be mature today if considering the important number of systems proposed by manufacturers. Unfortunately, the performances of active 3D scanners depend on the optical properties of the surface to digitize. As an example, on Fig 1.a, a 3D shape with a diffuse surface has been digitized with Comet V scanner (Steinbichler). The 3D reconstruction is presented on Fig 1.b. The same experiment was carried out on a similar object (same shape) but presenting a specular surface (Fig 1.c and Fig 1.d) ; it can clearly be observed, that the specularity influences of the performance of the digitization.

  18. Remote z-scanning with a macroscopic voice coil motor for fast 3D multiphoton laser scanning microscopy

    PubMed Central

    Rupprecht, Peter; Prendergast, Andrew; Wyart, Claire; Friedrich, Rainer W

    2016-01-01

    There is a high demand for 3D multiphoton imaging in neuroscience and other fields but scanning in axial direction presents technical challenges. We developed a focusing technique based on a remote movable mirror that is conjugate to the specimen plane and translated by a voice coil motor. We constructed cost-effective z-scanning modules from off-the-shelf components that can be mounted onto standard multiphoton laser scanning microscopes to extend scan patterns from 2D to 3D. Systems were designed for large objectives and provide high resolution, high speed and a large z-scan range (>300 μm). We used these systems for 3D multiphoton calcium imaging in the adult zebrafish brain and measured odor-evoked activity patterns across >1500 neurons with single-neuron resolution and high signal-to-noise ratio. PMID:27231612

  19. In vivo analysis of solar lentigines by reflectance confocal microscopy before and after Q-switched ruby laser treatment.

    PubMed

    Richtig, Erika; Hofmann-Wellenhof, Rainer; Kopera, Daisy; El-Shabrawi-Caelen, Laila; Ahlgrimm-Siess, Verena

    2011-03-01

    Solar lentigines are benign lesions usually found on sun-damaged skin. We investigated twelve cases of solar lentigines through dermoscopy and reflectance confocal microscopy, performed before, and 30 min and 10 days after, a single treatment with a Q-switched ruby laser. At baseline, all lesions showed characteristic features of solar lentigines in reflectance confocal microscopy analysis: regular honeycomb patterns, edged dermal papillae and cord-like rete ridges at the dermoepidermal junction. Thirty minutes post-laser treatment, blurred epidermal intercellular connections, dark structureless areas of different sizes and shapes in the lower epidermal layers, and hyporeflective dermal papillae, reflecting epidermal and dermal oedema, were observed. Ten days post-treatment highly reflective round-to polygonal areas and aggregated granules, representing extracellular melanin, were detected in all epidermal layers featuring regular honeycomb patterns. Reflectance confocal microscopy can be used to visualise dynamic skin processes, allowing non-invasive in vivo follow-up of skin lesions after treatment.

  20. Simultaneous Confocal Scanning Laser Ophthalmoscopy Combined with High-Resolution Spectral-Domain Optical Coherence Tomography: A Review

    PubMed Central

    Castro Lima, Verônica; Rodrigues, Eduardo B.; Nunes, Renata P.; Sallum, Juliana F.; Farah, Michel E.; Meyer, Carsten H.

    2011-01-01

    We aimed to evaluate technical aspects and the clinical relevance of a simultaneous confocal scanning laser ophthalmoscope and a high-speed, high-resolution, spectral-domain optical coherence tomography (SDOCT) device for retinal imaging. The principle of confocal scanning laser imaging provides a high resolution of retinal and choroidal vasculature with low light exposure. Enhanced contrast, details, and image sharpness are generated using confocality. The real-time SDOCT provides a new level of accuracy for assessment of the angiographic and morphological correlation. The combined system allows for simultaneous recordings of topographic and tomographic images with accurate correlation between them. Also it can provide simultaneous multimodal imaging of retinal pathologies, such as fluorescein and indocyanine green angiographies, infrared and blue reflectance (red-free) images, fundus autofluorescence images, and OCT scans (Spectralis HRA + OCT; Heidelberg Engineering, Heidelberg, Germany). The combination of various macular diagnostic tools can lead to a better understanding and improved knowledge of macular diseases. PMID:22132313

  1. Further study of trichosanthin's effect on mouse embryos with confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Xu, Hui; Zhang, Chunyang; Ma, Hui; Chen, Die Yan

    2001-09-01

    Trichosanthin(TCS), a ribosome inactivating protein extracted from the root tuber of a traditional Chinese medicine herb Tian Huo Fen(THF), possessed abortifacient, anti-tumor and anti-human immunodeficiency virus(HIV) activities. For centuries in China, THF has been used as an effective folk medicine to terminate early and midtrimester pregnancies and to treat ectopic pregnancies, hydatidiform moles and trophoblastic tumor. We observed the changes in reactive oxygen species and intracellular calcium in mouse embryos induced by TCS with confocal laser scanning microscopy in combination with the fluorescene diacetate (DCFHDA) and Fluo-3-AM. The results indicated that TCS induced increase in intracellular calcium and production of reactive oxygen species in mouse embryos , and TCS inhibited the development of mouse embryos effectively. Mouse embryos of different developmental stages before implantation are used in the experiments. This provides new insight into mechanism for abortifacient activity of TCS.

  2. Aerogel Track Morphology: Measurement, Three Dimensional Reconstruction and Particle Location using Confocal Laser Scanning Microscopy

    NASA Technical Reports Server (NTRS)

    Kearsley, A. T.; Ball, A. D.; Wozniakiewicz, P. A.; Graham, G. A.; Burchell, M. J.; Cole, M. J.; Horz, F.; See, T. H.

    2007-01-01

    The Stardust spacecraft returned the first undoubted samples of cometary dust, with many grains embedded in the silica aerogel collector . Although many tracks contain one or more large terminal particles of a wide range of mineral compositions , there is also abundant material along the track walls. To help interpret the full particle size, structure and mass, both experimental simulation of impact by shots and numerical modeling of the impact process have been attempted. However, all approaches require accurate and precise measurement of impact track size parameters such as length, width and volume of specific portions. To make such measurements is not easy, especially if extensive aerogel fracturing and discoloration has occurred. In this paper we describe the application and limitations of laser confocal imagery for determination of aerogel track parameters, and for the location of particle remains.

  3. Evaluation of the Cytotoxic Behavior of Fungal Extracellular Synthesized Ag Nanoparticles Using Confocal Laser Scanning Microscope

    PubMed Central

    Salaheldin, Taher A.; Husseiny, Sherif M.; Al-Enizi, Abdullah M.; Elzatahry, Ahmed; Cowley, Alan H.

    2016-01-01

    Silver nanoparticles have been synthesized by subjecting a reaction medium to a Fusarium oxysporum biomass at 28 °C for 96 h. The biosynthesized Ag nanoparticles were characterized on the basis of their anticipated peak at 405 nm using UV-Vis-NIR spectroscopy. Structural confirmation was evident from the characteristic X-ray diffraction (XRD) pattern, high-resolution transmission electron Microscopy (HRTEM) and the particle size analyzer. The Ag nanoparticles were of dimension 40 ± 5 nm and spherical in shape. The study mainly focused on using the confocal laser scanning microscope (CLSM) to examine the cytotoxic activities of fungal synthesized Ag nanoparticles on a human breast carcinoma cell line MCF7 cell, which featured remarkable vacuolation, thus indicating a potent cytotoxic activity. PMID:26950118

  4. Confocal laser scanning microscopy detection of chlorophylls and carotenoids in chloroplasts and chromoplasts of tomato fruit.

    PubMed

    D'Andrea, Lucio; Amenós, Montse; Rodríguez-Concepción, Manuel

    2014-01-01

    Plant cells are unique among eukaryotic cells because of the presence of plastids, including chloroplasts and chromoplasts. Chloroplasts are found in green tissues and harbor the photosynthetic machinery (including chlorophyll molecules), while chromoplasts are present in non-photosynthetic tissues and accumulate large amounts of carotenoids. During tomato fruit development, chloroplasts are converted into chromoplasts that accumulate high levels of lycopene, a linear carotenoid responsible for the characteristic red color of ripe fruit. Here, we describe a simple and fast method to detect both types of fully differentiated plastids (chloroplasts and chromoplasts), as well as intermediate stages, in fresh tomato fruits. The method is based on the differential autofluorescence of chlorophylls and carotenoids (lycopene) detected by Confocal Laser Scanning Microscopy.

  5. Measurement of buried undercut structures in microfluidic devices by laser fluorescent confocal microscopy

    SciTech Connect

    Li Shiguang; Liu Jing; Nguyen, Nam-Trung; Fang Zhongping; Yoon, Soon Fatt

    2009-11-20

    Measuring buried, undercut microstructures is a challenging task in metrology. These structures are usually characterized by measuring their cross sections after physically cutting the samples. This method is destructive and the obtained information is incomplete. The distortion due to cutting also affects the measurement accuracy. In this paper, we first apply the laser fluorescent confocal microscopy and intensity differentiation algorithm to obtain the complete three-dimensional profile of the buried, undercut structures in microfluidic devices, which are made by the soft lithography technique and bonded by the oxygen plasma method. The impact of material wettability and the refractive index (n) mismatch among the liquid, samples, cover layer, and objective on the measurement accuracy are experimentally investigated.

  6. Characterization of acoustic lenses with the Foucault test by confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Ahmed Mohamed, E. T.; Abdelrahman, A.; Pluta, M.; Grill, W.

    2010-03-01

    In this work, the Foucault knife-edge test, which has traditionally been known as the classic test for optical imaging devices, is used to characterize an acoustic lens for operation at 1.2 GHz. A confocal laser scanning microscope (CLSM) was used as the illumination and detection device utilizing its pinhole instead of the classical knife edge that is normally employed in the Foucault test. Information about the geometrical characteristics, such as the half opening angle of the acoustic lens, were determined as well as the quality of the calotte of the lens used for focusing. The smallest focal spot size that could be achieved with the examined lens employed as a spherical reflector was found to be about 1 μm. By comparison to the idealized resolution a degradation of about a factor of 2 can be deduced. This limits the actual quality of the acoustic focus.

  7. Visualization of microcrack anisotropy in granite affected by afault zone, using confocal laser scanning microscope

    SciTech Connect

    Onishi, Celia T.; Shimizu, Ichiko

    2004-01-02

    Brittle deformation in granite can generate a fracture system with different patterns. Detailed fracture analyses at both macroscopic and microscopic scales, together with physical property data from a drill-core, are used to classify the effects of reverse fault deformation in four domains: (1) undeformed granite, (2) fractured granite with cataclastic seams, (3) fractured granite from the damage zone, and (4) foliated cataclasite from the core of the fault. Intact samples from two orthogonal directions, horizontal (H) and vertical (V), from the four domains indicate a developing fracture anisotropy toward the fault, which is highly developed in the damage zone. As a specific illustration of this phenomenon, resin impregnation, using a confocal laser scanning microscope (CLSM) technique is applied to visualize the fracture anisotropy developed in the Toki Granite, Japan. As a result, microcrack networks have been observed to develop in H sections and elongate open cracks in V sections, suggesting that flow pathways can be determined by deformation.

  8. Pharmaceutical applications of confocal laser scanning microscopy: the physical characterisation of pharmaceutical systems.

    PubMed

    Pygall, Samuel R; Whetstone, Joanne; Timmins, Peter; Melia, Colin D

    2007-12-10

    The application of confocal laser scanning microscopy (CLSM) to the physicochemical characterisation of pharmaceutical systems is not as widespread as its application within the field of cell biology. However, methods have been developed to exploit the imaging capabilities of CLSM to study a wide range of pharmaceutical systems, including phase-separated polymers, colloidal systems, microspheres, pellets, tablets, film coatings, hydrophilic matrices, and chromatographic stationary phases. Additionally, methods to measure diffusion in gels, bioadhesives, and for monitoring microenvironmental pH change within dosage forms have been utilised. CLSM has also been used in the study of the physical interaction of dosage forms with biological barriers such as the eye, skin and intestinal epithelia, and in particular, to determine the effectiveness of a plethora of pharmaceutical systems to deliver drugs through these barriers. In the future, there is continuing scope for wider exploitation of existing techniques, and continuing advancements in instrumentation.

  9. Trypan blue as a fluorochrome for confocal laser scanning microscopy of arbuscular mycorrhizae in three mangroves.

    PubMed

    Kumar, T; Majumdar, A; Das, P; Sarafis, V; Ghose, M

    2008-06-01

    Roots of three mangroves, Acanthus ilicifolius, Ceriops tagal and Excoecaria agallocha, collected from forests of the Sundarbans of India were stained with trypan blue to observe arbuscular mycorrhizal colonization. Spores of arbuscular mycorrhizal fungi isolated from rhizospheric soil, collected together with the root samples, also were stained for testing the suitability of the dye as a fluorochrome. Confocal laser scanning microscopy images were constructed. A. ilicifolius and E. agallocha exhibited "Arum" type colonization with highly branched arbuscules, whereas C. tagal showed "Paris" type association with clumped and collapsed arbuscules. We demonstrated that trypan blue is a suitable fluorochrome for staining arbuscular mycorrhizal fungal spores, fungal hyphae, arbuscules and vesicles, which presumably have a considerable amount of surface chitin. It appears that as the integration of chitin into the fungal cell wall changes, its accessibility to trypan blue dye also changes.

  10. An alternative method of promoter assessment by confocal laser scanning microscopy.

    PubMed

    Sahoo, Dipak K; Ranjan, Rajiv; Kumar, Deepak; Kumar, Alok; Sahoo, Bhabani S; Raha, Sumita; Maiti, Indu B; Dey, Nrisingha

    2009-10-01

    A rapid and useful method of promoter activity analysis using techniques of confocal laser scanning microscopy (CLSM) is described in the present study. The activities of some pararetroviral promoters such as CaMV35S (Cauliflower mosaic virus), FMVSgt3 (Figwort mosaic virus sub-genomic transcript) and MMVFLt12 (Mirabilis mosaic virus full-length transcript) coupled to GFP (green fluorescent protein) and GUS (beta-glucuronidase) reporter genes were determined simultaneously by the CLSM technique and other available conventional methods for reporter gene assay based on relevant biochemical and molecular approaches. Consistent and comparable results obtained by CLSM as well as by other conventional assay methods confirm the effectiveness of the CLSM approach for assessment of promoter activity. Hence the CLSM method can be suggested as an alternative way for promoter analysis on the basis of high throughput.

  11. A Review of Probe-Based Confocal Laser Endomicroscopy for Pancreaticobiliary Disease.

    PubMed

    Karia, Kunal; Kahaleh, Michel

    2016-09-01

    Confocal laser endomicroscopy (CLE) is a novel in vivo imaging technique that can provide real-time optical biopsies in the evaluation of pancreaticobiliary strictures and pancreatic cystic lesions (PCLs), both of which are plagued by low sensitivities of routine evaluation techniques. Compared to pathology alone, CLE is associated with a higher sensitivity and accuracy for the evaluation of indeterminate pancreaticobiliary strictures. CLE has the ability to determine the malignant potential of PCLs. As such, CLE can increase the diagnostic yield of endoscopic retrograde cholangiopancreatography and endoscopic ultrasound, reducing the need for repeat procedures. It has been shown to be safe, with an adverse event rate of ≤1%. Published literature regarding its cost-effectiveness is needed.

  12. A Review of Probe-Based Confocal Laser Endomicroscopy for Pancreaticobiliary Disease

    PubMed Central

    Karia, Kunal; Kahaleh, Michel

    2016-01-01

    Confocal laser endomicroscopy (CLE) is a novel in vivo imaging technique that can provide real-time optical biopsies in the evaluation of pancreaticobiliary strictures and pancreatic cystic lesions (PCLs), both of which are plagued by low sensitivities of routine evaluation techniques. Compared to pathology alone, CLE is associated with a higher sensitivity and accuracy for the evaluation of indeterminate pancreaticobiliary strictures. CLE has the ability to determine the malignant potential of PCLs. As such, CLE can increase the diagnostic yield of endoscopic retrograde cholangiopancreatography and endoscopic ultrasound, reducing the need for repeat procedures. It has been shown to be safe, with an adverse event rate of ≤1%. Published literature regarding its cost-effectiveness is needed. PMID:27642847

  13. Simultaneous acquisition of 3D shape and deformation by combination of interferometric and correlation-based laser speckle metrology

    PubMed Central

    Dekiff, Markus; Berssenbrügge, Philipp; Kemper, Björn; Denz, Cornelia; Dirksen, Dieter

    2015-01-01

    A metrology system combining three laser speckle measurement techniques for simultaneous determination of 3D shape and micro- and macroscopic deformations is presented. While microscopic deformations are determined by a combination of Digital Holographic Interferometry (DHI) and Digital Speckle Photography (DSP), macroscopic 3D shape, position and deformation are retrieved by photogrammetry based on digital image correlation of a projected laser speckle pattern. The photogrammetrically obtained data extend the measurement range of the DHI-DSP system and also increase the accuracy of the calculation of the sensitivity vector. Furthermore, a precise assignment of microscopic displacements to the object’s macroscopic shape for enhanced visualization is achieved. The approach allows for fast measurements with a simple setup. Key parameters of the system are optimized, and its precision and measurement range are demonstrated. As application examples, the deformation of a mandible model and the shrinkage of dental impression material are measured. PMID:26713197

  14. A review on powder-based additive manufacturing for tissue engineering: selective laser sintering and inkjet 3D printing

    NASA Astrophysics Data System (ADS)

    Farid Seyed Shirazi, Seyed; Gharehkhani, Samira; Mehrali, Mehdi; Yarmand, Hooman; Metselaar, Hendrik Simon Cornelis; Adib Kadri, Nahrizul; Azuan Abu Osman, Noor

    2015-06-01

    Since most starting materials for tissue engineering are in powder form, using powder-based additive manufacturing methods is attractive and practical. The principal point of employing additive manufacturing (AM) systems is to fabricate parts with arbitrary geometrical complexity with relatively minimal tooling cost and time. Selective laser sintering (SLS) and inkjet 3D printing (3DP) are two powerful and versatile AM techniques which are applicable to powder-based material systems. Hence, the latest state of knowledge available on the use of AM powder-based techniques in tissue engineering and their effect on mechanical and biological properties of fabricated tissues and scaffolds must be updated. Determining the effective setup of parameters, developing improved biocompatible/bioactive materials, and improving the mechanical/biological properties of laser sintered and 3D printed tissues are the three main concerns which have been investigated in this article.

  15. Simultaneous acquisition of 3D shape and deformation by combination of interferometric and correlation-based laser speckle metrology.

    PubMed

    Dekiff, Markus; Berssenbrügge, Philipp; Kemper, Björn; Denz, Cornelia; Dirksen, Dieter

    2015-12-01

    A metrology system combining three laser speckle measurement techniques for simultaneous determination of 3D shape and micro- and macroscopic deformations is presented. While microscopic deformations are determined by a combination of Digital Holographic Interferometry (DHI) and Digital Speckle Photography (DSP), macroscopic 3D shape, position and deformation are retrieved by photogrammetry based on digital image correlation of a projected laser speckle pattern. The photogrammetrically obtained data extend the measurement range of the DHI-DSP system and also increase the accuracy of the calculation of the sensitivity vector. Furthermore, a precise assignment of microscopic displacements to the object's macroscopic shape for enhanced visualization is achieved. The approach allows for fast measurements with a simple setup. Key parameters of the system are optimized, and its precision and measurement range are demonstrated. As application examples, the deformation of a mandible model and the shrinkage of dental impression material are measured.

  16. A review on powder-based additive manufacturing for tissue engineering: selective laser sintering and inkjet 3D printing.

    PubMed

    Shirazi, Seyed Farid Seyed; Gharehkhani, Samira; Mehrali, Mehdi; Yarmand, Hooman; Metselaar, Hendrik Simon Cornelis; Adib Kadri, Nahrizul; Osman, Noor Azuan Abu

    2015-06-01

    Since most starting materials for tissue engineering are in powder form, using powder-based additive manufacturing methods is attractive and practical. The principal point of employing additive manufacturing (AM) systems is to fabricate parts with arbitrary geometrical complexity with relatively minimal tooling cost and time. Selective laser sintering (SLS) and inkjet 3D printing (3DP) are two powerful and versatile AM techniques which are applicable to powder-based material systems. Hence, the latest state of knowledge available on the use of AM powder-based techniques in tissue engineering and their effect on mechanical and biological properties of fabricated tissues and scaffolds must be updated. Determining the effective setup of parameters, developing improved biocompatible/bioactive materials, and improving the mechanical/biological properties of laser sintered and 3D printed tissues are the three main concerns which have been investigated in this article.

  17. A review on powder-based additive manufacturing for tissue engineering: selective laser sintering and inkjet 3D printing

    PubMed Central

    Shirazi, Seyed Farid Seyed; Gharehkhani, Samira; Mehrali, Mehdi; Yarmand, Hooman; Metselaar, Hendrik Simon Cornelis; Adib Kadri, Nahrizul; Osman, Noor Azuan Abu

    2015-01-01

    Since most starting materials for tissue engineering are in powder form, using powder-based additive manufacturing methods is attractive and practical. The principal point of employing additive manufacturing (AM) systems is to fabricate parts with arbitrary geometrical complexity with relatively minimal tooling cost and time. Selective laser sintering (SLS) and inkjet 3D printing (3DP) are two powerful and versatile AM techniques which are applicable to powder-based material systems. Hence, the latest state of knowledge available on the use of AM powder-based techniques in tissue engineering and their effect on mechanical and biological properties of fabricated tissues and scaffolds must be updated. Determining the effective setup of parameters, developing improved biocompatible/bioactive materials, and improving the mechanical/biological properties of laser sintered and 3D printed tissues are the three main concerns which have been investigated in this article. PMID:27877783

  18. 3D finite element model for writing long-period fiber gratings by CO2 laser radiation.

    PubMed

    Coelho, João M P; Nespereira, Marta; Abreu, Manuel; Rebordão, José

    2013-08-12

    In the last years, mid-infrared radiation emitted by CO2 lasers has become increasing popular as a tool in the development of long-period fiber gratings. However, although the development and characterization of the resulting sensing devices have progressed quickly, further research is still necessary to consolidate functional models, especially regarding the interaction between laser radiation and the fiber's material. In this paper, a 3D finite element model is presented to simulate the interaction between laser radiation and an optical fiber and to determine the resulting refractive index change. Dependence with temperature of the main parameters of the optical fiber materials (with special focus on the absorption of incident laser radiation) is considered, as well as convection and radiation losses. Thermal and residual stress analyses are made for a standard single mode fiber, and experimental results are presented.

  19. 3D Finite Element Model for Writing Long-Period Fiber Gratings by CO2 Laser Radiation

    PubMed Central

    Coelho, João M. P.; Nespereira, Marta; Abreu, Manuel; Rebordão, José

    2013-01-01

    In the last years, mid-infrared radiation emitted by CO2 lasers has become increasing popular as a tool in the development of long-period fiber gratings. However, although the development and characterization of the resulting sensing devices have progressed quickly, further research is still necessary to consolidate functional models, especially regarding the interaction between laser radiation and the fiber's material. In this paper, a 3D finite element model is presented to simulate the interaction between laser radiation and an optical fiber and to determine the resulting refractive index change. Dependence with temperature of the main parameters of the optical fiber materials (with special focus on the absorption of incident laser radiation) is considered, as well as convection and radiation losses. Thermal and residual stress analyses are made for a standard single mode fiber, and experimental results are presented. PMID:23941908

  20. Fourier-Space Nonlinear Rayleigh-Taylor Growth Measurements of 3D Laser-Imprinted Modulations in Planar Targets

    SciTech Connect

    Smalyuk, V.A.; Sadot, O.; Delettrez, J.A.; Meyerhofer, D.D.; Regan, S.P.; Sangster, T.C.

    2005-12-05

    Nonlinear growth of 3-D broadband nonuniformities was measured near saturation levels using x-ray radiography in planar foils accelerated by laser light. The initial target modulations were seeded by laser nonuniformities and later amplified during acceleration by Rayleigh-Taylor instability. The nonlinear saturation velocities are measured for the first time and are found to be in excellent agreement with Haan predictions. The measured growth of long-wavelength modes is consistent with enhanced, nonlinear, long-wavelength generation in ablatively driven targets.

  1. 3-D TECATE/BREW: Thermal, stress, and birefringent ray-tracing codes for solid-state laser design

    NASA Astrophysics Data System (ADS)

    Gelinas, R. J.; Doss, S. K.; Nelson, R. G.

    1994-07-01

    This report describes the physics, code formulations, and numerics that are used in the TECATE (totally Eulerian code for anisotropic thermo-elasticity) and BREW (birefringent ray-tracing of electromagnetic waves) codes for laser design. These codes resolve thermal, stress, and birefringent optical effects in 3-D stationary solid-state systems. This suite of three constituent codes is a package referred to as LASRPAK.

  2. Use of a High-Resolution 3D Laser Scanner for Minefield Surface Modeling and Terrain Characterization: Temperature Region

    DTIC Science & Technology

    2005-08-01

    al. 2005). Background The highly accurate and dense point data (or point clouds ) captured by terrestrial 3D laser scanners, such as the Leica...intensity value. The sophisticated design of the scanner enables point clouds to be captured that 1...additional analyses. A ScanWorld can be defined as a collection of scanned point clouds that are derived from consecutive scans at the same scanner

  3. Experimental investigation and 3D-simulation of the ablated morphology of titanium surface using femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Liu, Dong; Chen, Chuansong; Man, Baoyuan; Meng, Xue; Sun, Yanna; Li, Feifei

    2015-12-01

    The femtosecond laser ablated morphology on titanium surface is investigated theoretically and experimentally. A three dimensional two temperature model (3D-TTM) is used to simulate the surface morphology of titanium sample which is irradiated by femtosecond laser pulses. The electron heat capacity and electron-phonon coupling coefficient of titanium (transition metal) are complex temperature dependent, so the two parameters are corrected based on the theory of electron density of states (DOS). The model is solved by the finite difference time domain (FDTD) method. The 3D temperature field near the target surface is achieved. The radius and depth of the ablated crater are obtained based on the temperature field. The evolutions of the crate's radius and depth with laser fluence are discussed and compared with the experimental results. It is found that the back-flow of the molten material and the deposition of the material vapor should be responsible for the little discrepancy between the simulated and experimental results. The present work makes a better understanding of the thermodynamic process of femtosecond laser ablating metal and meanwhile provides an effective method tool to predict the micro manufacturing process on metals with femtosecond laser.

  4. Digital holographic interferometer using simultaneously three lasers and a single monochrome sensor for 3D displacement measurements.

    PubMed

    Saucedo-A, Tonatiuh; De la Torre-Ibarra, M H; Santoyo, F Mendoza; Moreno, Ivan

    2010-09-13

    The use of digital holographic interferometry for 3D measurements using simultaneously three illumination directions was demonstrated by Saucedo et al. (Optics Express 14(4) 2006). The technique records two consecutive images where each one contains three holograms in it, e.g., one before the deformation and one after the deformation. A short coherence length laser must be used to obtain the simultaneous 3D information from the same laser source. In this manuscript we present an extension of this technique now illuminating simultaneously with three different lasers at 458, 532 and 633 nm, and using only one high resolution monochrome CMOS sensor. This new configuration gives the opportunity to use long coherence length lasers allowing the measurement of large object areas. A series of digital holographic interferograms are recorded and the information corresponding to each laser is isolated in the Fourier spectral domain where the corresponding phase difference is calculated. Experimental results render the orthogonal displacement components u, v and w during a simple load deformation.

  5. Standing-wave-excited multiplanar fluorescence in a laser scanning microscope reveals 3D information on red blood cells.

    PubMed

    Amor, Rumelo; Mahajan, Sumeet; Amos, William Bradshaw; McConnell, Gail

    2014-12-08

    Standing-wave excitation of fluorescence is highly desirable in optical microscopy because it improves the axial resolution. We demonstrate here that multiplanar excitation of fluorescence by a standing wave can be produced in a single-spot laser scanning microscope by placing a plane reflector close to the specimen. We report here a variation in the intensity of fluorescence of successive planes related to the Stokes shift of the dye. We show by the use of dyes specific for the cell membrane how standing-wave excitation can be exploited to generate precise contour maps of the surface membrane of red blood cells, with an axial resolution of ≈90 nm. The method, which requires only the addition of a plane mirror to an existing confocal laser scanning microscope, may well prove useful in studying diseases which involve the red cell membrane, such as malaria.

  6. Standing-wave-excited multiplanar fluorescence in a laser scanning microscope reveals 3D information on red blood cells

    NASA Astrophysics Data System (ADS)

    Amor, Rumelo; Mahajan, Sumeet; Amos, William Bradshaw; McConnell, Gail

    2014-12-01

    Standing-wave excitation of fluorescence is highly desirable in optical microscopy because it improves the axial resolution. We demonstrate here that multiplanar excitation of fluorescence by a standing wave can be produced in a single-spot laser scanning microscope by placing a plane reflector close to the specimen. We report here a variation in the intensity of fluorescence of successive planes related to the Stokes shift of the dye. We show by the use of dyes specific for the cell membrane how standing-wave excitation can be exploited to generate precise contour maps of the surface membrane of red blood cells, with an axial resolution of ~90 nm. The method, which requires only the addition of a plane mirror to an existing confocal laser scanning microscope, may well prove useful in studying diseases which involve the red cell membrane, such as malaria.

  7. Probe-based confocal laser endomicroscopy of the urinary tract: the technique.

    PubMed

    Chang, Timothy C; Liu, Jen-Jane; Liao, Joseph C

    2013-01-10

    Probe-based confocal laser endomicroscopy (CLE) is an emerging optical imaging technology that enables real-time in vivo microscopy of mucosal surfaces during standard endoscopy. With applications currently in the respiratory and gastrointestinal tracts, CLE has also been explored in the urinary tract for bladder cancer diagnosis. Cellular morphology and tissue microarchitecture can be resolved with micron scale resolution in real time, in addition to dynamic imaging of the normal and pathological vasculature. The probe-based CLE system (Cellvizio, Mauna Kea Technologies, France) consists of a reusable fiberoptic imaging probe coupled to a 488 nm laser scanning unit. The imaging probe is inserted in the working channels of standard flexible and rigid endoscopes. An endoscope-based CLE system (Optiscan, Australia), in which the confocal endomicroscopy functionality is integrated onto the endoscope, is also used in the gastrointestinal tract. Given the larger scope diameter, however, application in the urinary tract is currently limited to ex vivo use. Confocal image acquisition is done through direct contact of the imaging probe with the target tissue and recorded as video sequences. As in the gastrointestinal tract, endomicroscopy of the urinary tract requires an exogenenous contrast agent-most commonly fluorescein, which can be administered intravenously or intravesically. Intravesical administration is a well-established method to introduce pharmacological agents locally with minimal systemic toxicity that is unique to the urinary tract. Fluorescein rapidly stains the extracellular matrix and has an established safety profile. Imaging probes of various diameters enable compatibility with different caliber endoscopes. To date, 1.4 and 2.6 mm probes have been evaluated with flexible and rigid cystoscopy. Recent availability of a < 1 mm imaging probe opens up the possibility of CLE in the upper urinary tract during ureteroscopy. Fluorescence cystoscopy (i

  8. 3D integration of microfluidics and microoptics inside photosensitive glass by femtosecond laser direct writing for photonic biosensing

    NASA Astrophysics Data System (ADS)

    Sugioka, Koji; Wang, Zhongke; Midorikawa, Katsumi

    2008-02-01

    Optical waveguides with a propagation loss of around 0.5 dB/cm are written inside photosensitive Foturan glass by internal modification of refractive index using femtosecond (fs) laser. Integration of the optical wafveguides with a micromirror enables us to bend the guided laser beam at an angle of 90° with a bending loss of less than 0.3 dB. In the meanwhile, a plano-convex microlens is completely embedded inside the Foturan glass chip via formation of a three-dimensional (3D) hollow microstructure using fs laser direct writing followed by heat treatment and successive wet etching. This technique can also be used to fabricate microfluidic devices and therefore realizes 3D integration of microoptical and microfluidic components by one continuous procedure. Subsequently, microoptical waveguides are further integrated into the single glass chip. Demonstration of optical measurements using the integrated microchip reveals that photonic biosensing can be performed with an efficiency increased by a factor of 8 for fluorescence detection and by a factor of 3 for absorption detection.

  9. Mean cell size and collagen orientation from 2D Fourier analysis on confocal laser scanning microscopy and two-photon fluorescence microscopy on human skin in vivo

    NASA Astrophysics Data System (ADS)

    Lucassen, Gerald W.; Bakker, Bernard L.; Neerken, Sieglinde; Hendriks, Rob F. M.

    2003-07-01

    We present results from 2D Fourier analysis on 3D stacks of images obtained by confocal laser scanning reflectance microscopy (CLSM) and two-photon fluorescence microscopy (2PM) on human skin in vivo. CLSM images were obtained with a modified commercial system (Vivascope1000, Lucid Inc, excitation wavelength 830 nm) equipped with a piezo-focusing element (350 μm range) for depth positioning of the objective lens. 2PM was performed with a specially designed set-up with excitation wavelength 730 nm. Mean cell size in the epidermal layer and structural orientation in the dermal layer have been determined as a function of depth by 2D Fourier analysis. Fourier analysis on microscopic images enables automatic non-invasive quantitative structural analysis (mean cell size and orientation) of living human skin.

  10. SYDESCO: a laser-video scanner for 3D scoliosis evaluations.

    PubMed

    Treuillet, S; Lucas, Y; Crepin, G; Peuchot, B; Pichaud, J C

    2002-01-01

    SYDESCO is a new 3D vision system developed for trunk surface topography. This structured light surface scanner uses the principle of triangulation-based range sensing to infer 3D shape. The complete trunk acquisition is fast (2 seconds). The accuracy of the metric data is ensured by a subpixel image detection and a calibration process, which rectifies image deformations. A preliminary study presents results on 50 children in a gymnastics school. These children, aged between eight to sixteen years, are particularly exposed to spinal deformities. An asymmetry index is calculated from the 3D data to detect the pathologic cases. These results have been compared to an independent medical diagnosis. The system results have been confirmed for 72,1% of the patients.

  11. Increase of Readability and Accuracy of 3d Models Using Fusion of Close Range Photogrammetry and Laser Scanning

    NASA Astrophysics Data System (ADS)

    Gašparović, M.; Malarić, I.

    2012-07-01

    The development of laser scanning technology has opened a new page in geodesy and enabled an entirely new way of presenting data. Products obtained by the method of laser scanning are used in many sciences, as well as in archaeology. It should be noted that 3D models of archaeological artefacts obtained by laser scanning are fully measurable, written in 1:1 scale and have high accuracy. On the other hand, texture and RGB values of the surface of the object obtained by a laser scanner have lower resolution and poorer radiometric characteristics in relation to the textures captured with a digital camera. Scientific research and the goal of this paper are to increase the accuracy and readability of the 3D model with textures obtained with a digital camera. Laser scanning was performed with triangulation scanner of high accuracy, Vivid 9i (Konica Minolta), while for photogrammetric recording digital camera Nikon D90 with a lens of fixed focal length 20 mm, was used. It is important to stress that a posteriori accuracy score of the global registration of point clouds in the form of the standard deviation was ± 0.136 mm while the average distance was only ± 0.080 mm. Also research has proven that the quality projection texture model increases readability. Recording of archaeological artefacts and making their photorealistic 3D model greatly contributes to archaeology as a science, accelerates processing and reconstruction of the findings. It also allows the presentation of findings to the general public, not just to the experts.

  12. Femtosecond laser subsurface scleral treatment in cadaver human sclera and evaluation using two-photon and confocal microscopy

    NASA Astrophysics Data System (ADS)

    Sun, Hui; Fan, Zhongwei; Yan, Ying; Lian, Fuqiang; Kurtz, Ron; Juhasz, Tibor

    2016-03-01

    Glaucoma is the second-leading cause of blindness worldwide and is often associated with elevated intraocular pressure (IOP). Partial-thickness drainage channels can be created with femtosecond laser in the translucent sclera for the potential treatment of glaucoma. We demonstrate the creation of partial-thickness subsurface drainage channels with the femtosecond laser in the cadaver human eyeballs and describe the application of two-photon microscopy and confocal microscopy for noninvasive imaging of the femtosecond laser created partial-thickness scleral channels in cadaver human eyes. A femtosecond laser operating at a wavelength of 1700 nm was scanned along a rectangular raster pattern to create the partial thickness subsurface drainage channels in the sclera of cadaver human eyes. Analysis of the dimensions and location of these channels is important in understanding their effects. We describe the application of two-photon microscopy and confocal microscopy for noninvasive imaging of the femtosecond laser created partial-thickness scleral channels in cadaver human eyes. High-resolution images, hundreds of microns deep in the sclera, were obtained to allow determination of the shape and dimension of such partial thickness subsurface scleral channels. Our studies suggest that the confocal and two-photon microscopy can be used to investigate femtosecond-laser created partial-thickness drainage channels in the sclera of cadaver human eyes.

  13. See-Through Imaging of Laser-Scanned 3d Cultural Heritage Objects Based on Stochastic Rendering of Large-Scale Point Clouds

    NASA Astrophysics Data System (ADS)

    Tanaka, S.; Hasegawa, K.; Okamoto, N.; Umegaki, R.; Wang, S.; Uemura, M.; Okamoto, A.; Koyamada, K.

    2016-06-01

    We propose a method for the precise 3D see-through imaging, or transparent visualization, of the large-scale and complex point clouds acquired via the laser scanning of 3D cultural heritage objects. Our method is based on a stochastic algorithm and directly uses the 3D points, which are acquired using a laser scanner, as the rendering primitives. This method achieves the correct depth feel without requiring depth sorting of the rendering primitives along the line of sight. Eliminating this need allows us to avoid long computation times when creating natural and precise 3D see-through views of laser-scanned cultural heritage objects. The opacity of each laser-scanned object is also flexibly controllable. For a laser-scanned point cloud consisting of more than 107 or 108 3D points, the pre-processing requires only a few minutes, and the rendering can be executed at interactive frame rates. Our method enables the creation of cumulative 3D see-through images of time-series laser-scanned data. It also offers the possibility of fused visualization for observing a laser-scanned object behind a transparent high-quality photographic image placed in the 3D scene. We demonstrate the effectiveness of our method by applying it to festival floats of high cultural value. These festival floats have complex outer and inner 3D structures and are suitable for see-through imaging.

  14. Laser printing and femtosecond laser structuring of electrode materials for the manufacturing of 3D lithium-ion micro-batteries

    NASA Astrophysics Data System (ADS)

    Smyrek, P.; Kim, H.; Zheng, Y.; Seifert, H. J.; Piqué, A.; Pfleging, W.

    2016-04-01

    Recently, three-dimensional (3D) electrode architectures have attracted great interest for the development of lithium-ion micro-batteries applicable for Micro-Electro-Mechanical Systems (MEMS), sensors, and hearing aids. Since commercial available micro-batteries are mainly limited in overall cell capacity by their electrode footprint, new processing strategies for increasing both capacity and electrochemical performance have to be developed. In case of such standard microbatteries, two-dimensional (2D) electrode arrangements are applied with thicknesses up to 200 μm. These electrode layers are composed of active material, conductive agent, graphite, and polymeric binder. Nevertheless, with respect to the type of active material, the active material to conductive agent ratio, and the film thickness, such thick-films suffer from low ionic and electronic conductivities, poor electrolyte accessibility, and finally, limited electrochemical performance under challenging conditions. In order to overcome these drawbacks, 3D electrode arrangements are under intense investigation since they allow the reduction of lithium-ion diffusion pathways in between inter-digitated electrodes, even for electrodes with enhanced mass loadings. In this paper, we present how to combine laser-printing and femtosecond laser-structuring for the development of advanced 3D electrodes composed of Li(Ni1/3Mn1/3Co1/3)O2 (NMC). In a first step, NMC thick-films were laser-printed and calendered to achieve film thicknesses in the range of 50 μm - 80 μm. In a second step, femtosecond laser-structuring was carried out in order to generate 3D architectures directly into thick-films. Finally, electrochemical cycling of laser-processed films was performed in order to evaluate the most promising 3D electrode designs suitable for application in long life-time 3D micro-batteries.

  15. Study of the formation of 3-D titania nanofibrous structure by MHz femtosecond laser in ambient air

    SciTech Connect

    Tavangar, Amirhossein; Venkatakrishnan, K.; Tan Bo

    2013-01-14

    In this study, we describe the formation mechanism of web-like three-dimensional (3-D) titania nanofibrous structures during femtosecond laser ablation of titanium (Ti) targets in the presence of background air. First, we demonstrate the mechanism of ablation of Ti targets by multiple femtosecond laser pulses at ambient air in an explicit analytical form. The formulas for evaporation rates and the number of ablated particles, which is analogous to the deposition rate of the synthesized nanofibers, for the ablation by a single pulse and multiple pulses as a function of laser parameters, background gas, and material properties are predicted and compared to experimental results. Afterwards, the formation of nanofibrous structures is demonstrated by applying an existing simplified kinetic model to Ti targets and ambient conditions. The predicted theory provides nanofiber diameter dependency with the combination of laser parameters, target properties, and ambient gas characteristics. Experimental studies are then performed on titania nanofibrous structures synthesized by laser ablation of Ti targets using MHz repletion-rate femtosecond laser at ambient air. The models' predictions are then compared with the experimental results, where nanostructures with different morphologies are manufactured by altering laser parameters. Our results indicate that femtosecond laser ablation of Ti targets at air background yields crystalline titania nanostructures. The formation of crystalline titania nanostructures is preceded by thermal mechanism of nucleation and growth. The results point out that laser pulse repetition and dwell time can control the density, size, and pore size of the engineered nanofibrous structure. As the deposition rate of nanostructures is analogous to the ablation rate of the target, higher density of nanofibrous structure is seen at greater laser fluences. The predicted theory can be applied to predict ablation mechanism and nanofiber formation of different

  16. Clumped Isotope Thermometry of Geologic Methane (13CH3D) using Tunable Laser Mid-Infrared Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ono, S.; Zahniser, M. S.; McManus, J. B.; Nelson, D. D.

    2013-12-01

    Methane is both an alternative energy source as well as a significant greenhouse gas, and holds the potential for rapid release to the atmosphere, possibly triggering abrupt climate change in the past and in the future. The majority of methane on the Earth is biogenic, originating from microbial methanogenesis, or thermogenic sourced from previously formed biogenic organic materials. Methane can be also produced abiogenically during serpentinization and even mantle-sourced methane has been implicated. Carbon (13C/12C) and hydrogen (D/H) isotope ratios of methane and associated short chain hydrocarbons provide critical information about the abiogenic/biogenic origin of methane but data can be inconclusive. We have developed and tested a Tunable Infrared Laser Direct Absorption Spectroscopy (TILDAS) Instrument to be used for precise measurements of the abundance of doubly isotope-substituted methane (13CH3D). The TILDAS instrument measures direct absorption in the mid-infrared (~ 8 μm) region using continuous wave quantum cascade laser combined with a 76 m pathlength astigmatic absorption cell. Initial test result indicates the precision for 13CH4, 12CH3D and 13CH3D for 0.2 ‰ or better for comparison between two reference gases. Accuracy of the methods for δ13C and δD is evaluated by comparing measurements by conventional isotope ratio mass spectrometry. Calibration of clumped isotope scale (δ13CH3D) is underway using methane produced at various temperatures. Following an isotope exchange reaction (13CH4 + 12CH3D ↔ 13CH3D + 12CH4), precise measurements of 13CH3D abundance is expected to provide new and critical information about the temperature at which methane was formed (or thermally equilibrated). Biogenic origin becomes highly unlikely, for example, if the estimated temperature is higher than 120°C, i.e., current high-temperature limit of microbial methanogenesis. Although significant questions remain regarding isotope exchange kinetics, and clumped

  17. Real time diagnosis of bladder cancer with probe-based confocal laser endomicroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Jen-Jane; Wu, Katherine; Adams, Winifred; Hsiao, Shelly T.; Mach, Kathleen E.; Beck, Andrew H.; Jensen, Kristin C.; Liao, Joseph C.

    2011-02-01

    Probe-based confocal laser endomicroscopy (pCLE) is an emerging technology for in vivo optical imaging of the urinary tract. Particularly for bladder cancer, real time optical biopsy of suspected lesions will likely lead to improved management of bladder cancer. With pCLE, micron scale resolution is achieved with sterilizable imaging probes (1.4 or 2.6 mm diameter), which are compatible with standard cystoscopes and resectoscopes. Based on our initial experience to date (n = 66 patients), we have demonstrated the safety profile of intravesical fluorescein administration and established objective diagnostic criteria to differentiate between normal, benign, and neoplastic urothelium. Confocal images of normal bladder showed organized layers of umbrella cells, intermediate cells, and lamina propria. Low grade bladder cancer is characterized by densely packed monomorphic cells with central fibrovascular cores, whereas high grade cancer consists of highly disorganized microarchitecture and pleomorphic cells with indistinct cell borders. Currently, we are conducting a diagnostic accuracy study of pCLE for bladder cancer diagnosis. Patients scheduled to undergo transurethral resection of bladder tumor are recruited. Patients undergo first white light cystocopy (WLC), followed by pCLE, and finally histologic confirmation of the resected tissues. The diagnostic accuracy is determined both in real time by the operative surgeon and offline after additional image processing. Using histology as the standard, the sensitivity, specificity, positive and negative predictive value of WLC and WLC + pCLE are calculated. With additional validation, pCLE may prove to be a valuable adjunct to WLC for real time diagnosis of bladder cancer.

  18. Height control of laser metal-wire deposition based on iterative learning control and 3D scanning

    NASA Astrophysics Data System (ADS)

    Heralić, Almir; Christiansson, Anna-Karin; Lennartson, Bengt

    2012-09-01

    Laser Metal-wire Deposition is an additive manufacturing technique for solid freeform fabrication of fully dense metal structures. The technique is based on robotized laser welding and wire filler material, and the structures are built up layer by layer. The deposition process is, however, sensitive to disturbances and thus requires continuous monitoring and adjustments. In this work a 3D scanning system is developed and integrated with the robot control system for automatic in-process control of the deposition. The goal is to ensure stable deposition, by means of choosing a correct offset of the robot in the vertical direction, and obtaining a flat surface, for each deposited layer. The deviations in the layer height are compensated by controlling the wire feed rate on next deposition layer, based on the 3D scanned data, by means of iterative learning control. The system is tested through deposition of bosses, which is expected to be a typical application for this technique in the manufacture of jet engine components. The results show that iterative learning control including 3D scanning is a suitable method for automatic deposition of such structures. This paper presents the equipment, the control strategy and demonstrates the proposed approach with practical experiments.

  19. Synthesis of 3D nanostructured metal alloy of immiscible materials induced by megahertz-repetition femtosecond laser pulses

    PubMed Central

    2012-01-01

    In this work, we have proposed a concept for the generation of three-dimensional (3D) nanostructured metal alloys of immiscible materials induced by megahertz-frequency ultrafast laser pulses. A mixture of two microparticle materials (aluminum and nickel oxide) and nickel oxide microparticles coated onto an aluminum foil have been used in this study. After laser irradiation, three different types of nanostructure composites have been observed: aluminum embedded in nickel nuclei, agglomerated chain of aluminum and nickel nanoparticles, and finally, aluminum nanoparticles grown on nickel microparticles. In comparison with current nanofabrication methods which are used only for one-dimensional nanofabrication, this technique enables us to fabricate 3D nanostructured metal alloys of two or more nanoparticle materials with varied composite concentrations under various predetermined conditions. This technique can lead to promising solutions for the fabrication of 3D nanostructured metal alloys in applications such as fuel-cell energy generation and development of custom-designed, functionally graded biomaterials and biocomposites. PMID:22999219

  20. Adjustment of Sonar and Laser Acquisition Data for Building the 3D Reference Model of a Canal Tunnel.

    PubMed

    Moisan, Emmanuel; Charbonnier, Pierre; Foucher, Philippe; Grussenmeyer, Pierre; Guillemin, Samuel; Koehl, Mathieu

    2015-12-11

    In this paper, we focus on the construction of a full 3D model of a canal tunnel by combining terrestrial laser (for its above-water part) and sonar (for its underwater part) scans collected from static acquisitions. The modeling of such a structure is challenging because the sonar device is used in a narrow environment that induces many artifacts. Moreover, the location and the orientation of the sonar device are unknown. In our approach, sonar data are first simultaneously denoised and meshed. Then, above- and under-water point clouds are co-registered to generate directly the full 3D model of the canal tunnel. Faced with the lack of overlap between both models, we introduce a robust algorithm that relies on geometrical entities and partially-immersed targets, which are visible in both the laser and sonar point clouds. A full 3D model, visually promising, of the entrance of a canal tunnel is obtained. The analysis of the method raises several improvement directions that will help with obtaining more accurate models, in a more automated way, in the limits of the involved technology.

  1. Adjustment of Sonar and Laser Acquisition Data for Building the 3D Reference Model of a Canal Tunnel †

    PubMed Central

    Moisan, Emmanuel; Charbonnier, Pierre; Foucher, Philippe; Grussenmeyer, Pierre; Guillemin, Samuel; Koehl, Mathieu

    2015-01-01

    In this paper, we focus on the construction of a full 3D model of a canal tunnel by combining terrestrial laser (for its above-water part) and sonar (for its underwater part) scans collected from static acquisitions. The modeling of such a structure is challenging because the sonar device is used in a narrow environment that induces many artifacts. Moreover, the location and the orientation of the sonar device are unknown. In our approach, sonar data are first simultaneously denoised and meshed. Then, above- and under-water point clouds are co-registered to generate directly the full 3D model of the canal tunnel. Faced with the lack of overlap between both models, we introduce a robust algorithm that relies on geometrical entities and partially-immersed targets, which are visible in both the laser and sonar point clouds. A full 3D model, visually promising, of the entrance of a canal tunnel is obtained. The analysis of the method raises several improvement directions that will help with obtaining more accurate models, in a more automated way, in the limits of the involved technology. PMID:26690444

  2. Analysis of thin baked-on silicone layers by FTIR and 3D-Laser Scanning Microscopy.

    PubMed

    Funke, Stefanie; Matilainen, Julia; Nalenz, Heiko; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang

    2015-10-01

    Pre-filled syringes (PFS) and auto-injection devices with cartridges are increasingly used for parenteral administration. To assure functionality, silicone oil is applied to the inner surface of the glass barrel. Silicone oil migration into the product can be minimized by applying a thin but sufficient layer of silicone oil emulsion followed by thermal bake-on versus spraying-on silicone oil. Silicone layers thicker than 100nm resulting from regular spray-on siliconization can be characterized using interferometric profilometers. However, the analysis of thin silicone layers generated by bake-on siliconization is more challenging. In this paper, we have evaluated Fourier transform infrared (FTIR) spectroscopy after solvent extraction and a new 3D-Laser Scanning Microscopy (3D-LSM) to overcome this challenge. A multi-step solvent extraction and subsequent FTIR spectroscopy enabled to quantify baked-on silicone levels as low as 21-325μg per 5mL cartridge. 3D-LSM was successfully established to visualize and measure baked-on silicone layers as thin as 10nm. 3D-LSM was additionally used to analyze the silicone oil distribution within cartridges at such low levels. Both methods provided new, highly valuable insights to characterize the siliconization after processing, in order to achieve functionality.

  3. 3D modelling of Mt. Talaga Bodas Crater (Indonesia) by using terrestrial laser scanner for volcano hazard mitigation

    NASA Astrophysics Data System (ADS)

    Gumilar, Irwan; Abidin, Hasanuddin Z.; Putra, Andreas D.; Haerani, Nia

    2015-04-01

    Indonesia is a country with many volcanoes. Each volcano in Indonesia typically has its own crater characteristics. One of them is the Mt.Talaga Bodas, located in Garut, West Java. Researches regarding the crater characteristics are necessary for volcanic disaster mitigation process. One of them is the modelling of the shape of the crater. One of the methods that can be used to model the volcanic crater is using Terrestrial Laser Scanner (TLS). This research aims to create a 3 dimensional (3D) model of the crater of the Mt. Talaga Bodas, that hopefully can be utilized for volcanic disaster mitigation. The methodology used in this research is by obtaining the scanning data using TLS and GPS measurements to obtain the coordinates of the reference points. The data processing methods consist of several steps, namely target to target registration, filterization, georeference, meshing point cloud, surface making, drawing, and 3D modelling. These steps were done using the Cyclone 7 software, and also using 3DS MAX for 3D modelling. The result of this data processing is a 3D model of the crater of the Mt. Talaga Bodas which is similar with the real shape. The calculation result shows that the height of the crater is 62.522 m, the diameter of the crater is 467.231 m, and the total area is 2961054.652 m2. The main obstacle in this research is the dense vegetation which becomes the noise and affects the crater model.

  4. Development of a low cost, 3-DOF desktop laser cutter using 3D printer hardware

    NASA Astrophysics Data System (ADS)

    Jivraj, Jamil; Huang, Yize; Wong, Ronnie; Lu, Yi; Vuong, Barry; Ramjist, Joel; Gu, Xijia; Yang, Victor X. D.

    2015-03-01

    This paper presents the development of a compact, desktop laser-cutting system capable of cutting materials such as wood, metal and plastic. A re-commissioned beheaded MakerBot® Replicator 2X is turned into a 3-DOF laser cutter by way of integration with 800W (peak power) fiber laser. Special attention is paid to tear-down, modification and integration of the objective lens in place of the print head. Example cuts in wood and metal will be presented, as well as design of an exhaust system.

  5. Benchmarking Naval Shipbuilding With 3D Laser Scanning, Additive Manufacturing, and Collaborative Product Lifecycle Management

    DTIC Science & Technology

    2016-04-30

    methods use subtractive processes (e.g., machining), but AM builds a 3D object by gradually adding successive layers of material that are laid down...practice. For example, RFID is frequently used to control construction material flows (CoreRFID, 2008). Damen Industries is developing animated... build -up part • Variety of possible materials (plastic, titanium) & methods (e.g. for material bonding) • No dominant method, materials

  6. Determination of the sequence of line crossings by means of 3D laser profilometry

    NASA Astrophysics Data System (ADS)

    Schirripa Spagnolo, Giuseppe; Simonetti, Carla; Cozzella, Lorenzo

    2005-09-01

    The determination of the sequence of line crossings is still a current problem in the field of forensic documents examination. This paper presents the potentiality of the 3D micro-topography to resolve the writing order of signatures (if partially superimposed), to detect the tampering of manuscripts (if the added inscription superimposes itself on parts already written), to analyze pressure variation, and to identify strokes in handwritten. The system used, in this paper for creating 3D micro-topography, is based on conoscopic holography. It is a non-contact three-dimensional measuring system that allows producing holograms, even with incoherent light, with fringe periods that can be measured precisely to determine the exact distance to the point measured. This technique is suitable to obtain 3D micro-topography with high resolution also on surfaces with unevenness reflectivity (which is usual on the surface of the handwritten document). The proposed technique is able to obtained 3D profile in non-invading way. Therefore, the original draft do not be physically or chemically modified, allowing the possibility of multi-analysis in different time, also in case of forensic analysis with the necessity to preserving the original sample. The experiments performed with line crossings data base show that the proposed method is able of "positive identification" of writing sequence in the majority of the tests. When we have not had a positive identification, the result has been "inconclusive". The proposed technique, if correctly used, does not supply "false positive" or "probable" identifications. The possible results are only: "positive identification" and "inconclusive".

  7. Suspect Height Estimation Using the Faro Focus(3D) Laser Scanner.

    PubMed

    Johnson, Monique; Liscio, Eugene

    2015-11-01

    At present, very little research has been devoted to investigating the ability of laser scanning technology to accurately measure height from surveillance video. The goal of this study was to test the accuracy of one particular laser scanner to estimate suspect height from video footage. The known heights of 10 individuals were measured using an anthropometer. The individuals were then recorded on video walking along a predetermined path in a simulated crime scene environment both with and without headwear. The difference between the known heights and the estimated heights obtained from the laser scanner software were compared using a one-way t-test. The height estimates obtained from the software were not significantly different from the known heights whether individuals were wearing headwear (p = 0.186) or not (p = 0.707). Thus, laser scanning is one technique that could potentially be used by investigators to determine suspect height from video footage.

  8. CD87-positive tumor cells in bone marrow aspirates identified by confocal laser scanning fluorescence microscopy.

    PubMed

    Noack, F; Helmecke, D; Rosenberg, R; Thorban, S; Nekarda, H; Fink, U; Lewald, J; Stich, M; Schutze, K; Harbeck, N; Magdolen, V; Graeff, H; Schmitt, M

    1999-10-01

    Dissemination of single tumor cells to the bone marrow is a common event in cancer. The clinical significance of cytokeratin-positive cells detected in the bone marrow of cancer patients is still a matter of debate. In gastric cancer, overexpression of the receptor (uPAR or CD87) for the serine protease urokinase-type plasminogen activator (uPA) in disseminated cancer cells indicates shorter survival of cancer patients. A new immunofluorescence approach, applying confocal laser scanning microscopy, is introduced to locate CD87 antigen in cytokeratin-positive tumor cells and to quantify the CD87 antigen by consecutive scanning. At first, cytokeratin 8/18/19-positive carcinoma cells are identified at excitation wavelength 488 nm using monoclonal antibody A45B/B3 to the cytokeratins and goat anti-mouse IgG labeled with the fluorochrome Alexa488. Next, CD87 in tumor cells is identified by chicken antibody HU277 to the uPA-receptor and goat anti-chicken IgY labeled with fluorochrome Alexa568 (excitation wavelength 568 nm) and the fluorescence signal quantified on a single cell basis using fluorescently labeled latex beads as the fluorescence reference. From 16 patients with gastric or esophageal carcinoma, bone marrow aspirates were obtained, stained for cytokeratins and CD87 and then subjected to laser scanning fluorescence microscopy. Three of six gastric cancer patients had tumor cells present in the bone marrow of which 2 stained for CD87. Three of ten esophageal carcinoma patients had tumor cells in the bone marrow, all three samples stained for CD87. CD87-positive tumor cells were also dissected from stained bone marrow aspirates by laser microdissection microscope to allow analysis of single cells at the gene level.

  9. Utilizing confocal laser endomicroscopy for evaluating the adequacy of laparoscopic liver ablation

    PubMed Central

    Johnson, Sean P.; Walker‐Samuel, Simon; Gurusamy, Kurinchi; Clarkson, Matthew J.; Thompson, Stephen; Song, Yi; Totz, Johannes; Cook, Richard J.; Desjardins, Adrien E.; Hawkes, David J.; Davidson, Brian R.

    2015-01-01

    Background Laparoscopic liver ablation therapy can be used for the treatment of primary and secondary liver malignancy. The increased incidence of cancer recurrence associated with this approach, has been attributed to the inability of monitoring the extent of ablated liver tissue. Methods The feasibility of assessing liver ablation with probe‐based confocal laser endomicroscopy (CLE) was studied in a porcine model of laparoscopic microwave liver ablation. Following the intravenous injection of the fluorophores fluorescein and indocyanine green, CLE images were recorded at 488 nm and 660 nm wavelength and compared to liver histology. Statistical analysis was performed to assess if fluorescence intensity change can predict the presence of ablated liver tissue. Results CLE imaging of fluorescein at 488 nm provided good visualization of the hepatic microvasculature; whereas, CLE imaging of indocyanine green at 660 nm enabled detailed visualization of hepatic sinusoid architecture and interlobular septations. Fluorescence intensity as measured in relative fluorescence units was found to be 75–100% lower in ablated compared to healthy liver regions. General linear mixed modeling and ROC analysis found the decrease in fluorescence to be statistically significant. Conclusion Laparoscopic, dual wavelength CLE imaging using two different fluorophores enables clinically useful visualization of multiple liver tissue compartments, in greater detail than is possible at a single wavelength. CLE imaging may provide valuable intraoperative information on the extent of laparoscopic liver ablation. Lasers Surg. Med. 48:299–310, 2016. © 2015 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc. PMID:26718623

  10. Time-dependent 3-D modelling of laser surface heating for the hardening of metallic materials

    NASA Astrophysics Data System (ADS)

    Colombo, V.; Mentrelli, A.; Trombetti, T.

    2003-12-01

    A numerical code for the time-dependent three-dimensional modelling of the laser surface heating for the hardening of metallic materials has been developed by the authors. The temperature-dependence of the thermal properties of the material (stainless steel) is taken into account in the frame of a heating process that doesn’t lead to material melting or evaporation. Calculations have been carried out for various dimensions of the parallelepiped-shaped and of the square-shaped spot of the laser beam, as well as for different scanning velocity and for different levels of the laser source power. Various patterns of the laser spot path have also been studied, including a single-pass hardening pattern, a double-pass hardening pattern with and without overlapping, multiple discontinuous and continuous hardening patterns and spiral hardening patterns. The presented results show how the proposed model can be usefully employed in the prediction of the time-evolution of temperature distribution which arises in the workpiece as a consequence of the laser-workpiece interaction under operating conditions typically encountered in industrial applications of the laser hardening process.

  11. Automatic construction of 3D basic-semantic models of inhabited interiors using laser scanners and RFID sensors.

    PubMed

    Valero, Enrique; Adan, Antonio; Cerrada, Carlos

    2012-01-01

    This paper is focused on the automatic construction of 3D basic-semantic models of inhabited interiors using laser scanners with the help of RFID technologies. This is an innovative approach, in whose field scarce publications exist. The general strategy consists of carrying out a selective and sequential segmentation from the cloud of points by means of different algorithms which depend on the information that the RFID tags provide. The identification of basic elements of the scene, such as walls, floor, ceiling, windows, doors, tables, chairs and cabinets, and the positioning of their corresponding models can then be calculated. The fusion of both technologies thus allows a simplified 3D semantic indoor model to be obtained. This method has been tested in real scenes under difficult clutter and occlusion conditions, and has yielded promising results.

  12. Automatic Construction of 3D Basic-Semantic Models of Inhabited Interiors Using Laser Scanners and RFID Sensors

    PubMed Central

    Valero, Enrique; Adan, Antonio; Cerrada, Carlos

    2012-01-01

    This paper is focused on the automatic construction of 3D basic-semantic models of inhabited interiors using laser scanners with the help of RFID technologies. This is an innovative approach, in whose field scarce publications exist. The general strategy consists of carrying out a selective and sequential segmentation from the cloud of points by means of different algorithms which depend on the information that the RFID tags provide. The identification of basic elements of the scene, such as walls, floor, ceiling, windows, doors, tables, chairs and cabinets, and the positioning of their corresponding models can then be calculated. The fusion of both technologies thus allows a simplified 3D semantic indoor model to be obtained. This method has been tested in real scenes under difficult clutter and occlusion conditions, and has yielded promising results. PMID:22778609

  13. Technical note: Reliability of Suchey-Brooks and Buckberry-Chamberlain methods on 3D visualizations from CT and laser scans.

    PubMed

    Villa, Chiara; Buckberry, Jo; Cattaneo, Cristina; Lynnerup, Niels

    2013-05-01

    Previous studies have reported that the ageing method of Suchey-Brooks (pubic bone) and some of the features applied by Lovejoy et al. and Buckberry-Chamberlain (auricular surface) can be confidently performed on 3D visualizations from CT-scans. In this study, seven observers applied the Suchey-Brooks and the Buckberry-Chamberlain methods on 3D visualizations based on CT-scans and, for the first time, on 3D visualizations from laser scans. We examined how the bone features can be evaluated on 3D visualizations and whether the different modalities (direct observations of bones, 3D visualization from CT-scan and from laser scans) are alike to different observers. We found the best inter-observer agreement for the bones versus 3D visualizations, with the highest values for the auricular surface. Between the 3D modalities, less variability was obtained for the 3D laser visualizations. Fair inter-observer agreement was obtained in the evaluation of the pubic bone in all modalities. In 3D visualizations of the auricular surfaces, transverse organization and apical changes could be evaluated, although with high inter-observer variability; micro-, macroporosity and surface texture were very difficult to score. In conclusion, these methods were developed for dry bones, where they perform best. The Suchey-Brooks method can be applied on 3D visualizations from CT or laser, but with less accuracy than on dry bone. The Buckberry-Chamberlain method should be modified before application on 3D visualizations. Future investigation should focus on a different approach and different features: 3D laser scans could be analyzed with mathematical approaches and sub-surface features should be explored on CT-scans.

  14. ROMY - The First Large 3D Ring Laser Structure for Seismology and Geodesy

    NASA Astrophysics Data System (ADS)

    Schreiber, Karl Ulrich; Igel, Heiner; Wassermann, Joachim; Lin, Chin-Jen; Gebauer, André; Wells, Jon-Paul

    2016-04-01

    Large ring laser gyroscopes have matured to the point that they can routinely observe rotational motions from geophysical processes that can be used in geodesy and seismology. The ring lasers used for this purpose enclose areas between 16 and 800 square meters and have in common that they can only measure rotations around the vertical axis because the structures are horizontally placed on the floor. With the ROMY project we have embarked on the construction of a full 3-dimensional rotation sensor. The actual apparatus consists of four individual triangular ring lasers arranged in the shape of a tetrahedron with 12 m of length on each side. At each corner of the tetrahedron three of the ring lasers are rigidly tied together to the same mechanical reference. The overall size of the installation provides a promising compromise between sensor stability on one side and sensor resolution on the other side. This talk introduces the technical concept of the ROMY ring laser installation and will also briefly outline the requirements for applications in space geodesy.

  15. Multi-frequency, 3D ODS measurement by continuous scan laser Doppler vibrometry

    NASA Astrophysics Data System (ADS)

    Weekes, Ben; Ewins, David

    2015-06-01

    Continuous scan laser Doppler vibrometry (CSLDV) is a technique which has been described and explored in the literature for over two decades, but remains niche compared to SLDV inspection by a series of discrete-point measurements. This is in part because of the unavoidable phenomenon of laser speckle, which deteriorates signal quality when velocity data is captured from a moving spot measurement. Further, applicability of CSLDV has typically been limited to line scans and rectangular areas by the application of sine, step, or ramp functions to the scanning mirrors which control the location of the measurement laser spot. In this paper it is shown that arbitrary functions to scan any area can easily be derived from a basic calibration routine, equivalent to the calibration performed in conventional discrete-point laser vibrometry. This is extended by performing the same scan path upon a test surface from three independent locations of the laser head, and decomposing the three sets of one-dimensional deflection shapes into a single set of three-dimensional deflection shapes. The test was performed with multi-sine excitation, yielding 34 operating deflection shapes from each scan.

  16. Amplitude-modulated laser range-finder for 3D imaging with multi-sensor data integration capabilities

    NASA Astrophysics Data System (ADS)

    Bartolini, L.; Ferri de Collibus, M.; Fornetti, G.; Guarneri, M.; Paglia, E.; Poggi, C.; Ricci, R.

    2005-06-01

    A high performance Amplitude Modulated Laser Rangefinder (AM-LR) is presented, aimed at accurately reconstructing 3D digital models of real targets, either single objects or complex scenes. The scanning system enables to sweep the sounding beam either linearly across the object or circularly around it, by placing the object on a controlled rotating platform. Both phase shift and amplitude of the modulating wave of back-scattered light are collected and processed, resulting respectively in an accurate range image and a shade-free, high resolution, photographic-like intensity image. The best performances obtained in terms of range resolution are ~100 μm. Resolution itself can be made to depend mainly on the laser modulation frequency, provided that the power of the backscattered light reaching the detector is at least a few nW. 3D models are reconstructed from sampled points by using specifically developed software tools, optimized so as to take advantage of the system peculiarities. Special procedures have also been implemented to perform precise matching of data acquired independently with different sensors (LIF laser sensors, thermographic cameras, etc.) onto the 3D models generated using the AM-LR. The system has been used to scan different types of real surfaces (stone, wood, alloys, bones) and ca be applied in various fields, ranging from industrial machining to medical diagnostics, vision in hostile environments cultural heritage conservation and restoration. The relevance of this technology in cultural heritage applications is discussed in special detail, by providing results obtained in different campaigns with an emphasis on the system's multi-sensor data integration capabilities.

  17. Multi-user 3D display using a head tracker and RGB laser illumination source

    NASA Astrophysics Data System (ADS)

    Surman, Phil; Sexton, Ian; Hopf, Klaus; Bates, Richard; Lee, Wing Kai; Buckley, Edward

    2007-05-01

    A glasses-free (auto-stereoscopic) 3D display that will serve several viewers who have freedom of movement over a large viewing region is described. This operates on the principle of employing head position tracking to provide regions referred to as exit pupils that follow the positions ofthe viewers' eyes in order for appropriate left and right images to be seen. A non-intrusive multi-user head tracker controls the light sources of a specially designed backlight that illuminates a direct-view LCD.

  18. The measurement of 3-D asymmetric temperature field by using real time laser interferometric tomography

    NASA Astrophysics Data System (ADS)

    Wang, Dezhong; Zhuang, Tiange

    2001-09-01

    A real time nondestructive temperature measurement technique based on laser holographic interference tomography technique is presented. An He-Ne laser is used as light source, and a CCD video camera is used to grab the interferogram. This laser holographic tomography technique is applied to the measurement of the temperature fields generated by two heated rods. Since data error is inevitable in engineering measurement, it is necessary to study the reconstruction techniques for reconstructing the temperature field. Three techniques including convolution back projection (CBP), algebra reconstruction technique (ART) and simultaneous iterative reconstruction technique (SIRT) are studied. Based on the reconstruction techniques and experimental situation, ART is used to reconstruct the asymmetric temperature fields. The thermocouples are used to measure the temperatures of the two heated rods. Comparing the reconstructed result with the measured temperature value, a satisfactory result is obtained.

  19. Femtosecond laser 3D micromachining and its applications to biochip fabrication

    NASA Astrophysics Data System (ADS)

    Sugioka, Koji

    2014-03-01

    Femtosecond lasers have opened up new avenues in materials processing due to their unique characteristics of ultra-short pulse widths and extremely high peak intensities that induce strong absorption in even transparent materials due to nonlinear multiphoton absorption. Then, the femtosecond laser can directly fabricate three-dimensional microfluidic, micromechanic, microelectronic, and micro-optical components in glass. These microcomponents can be easily integrated in a single glass microchip, which enable us to fabricate functional biochips quickly screening large number of biological analytes. In this talk, the detailed fabrication procedure of biochips using the femtosecond laser and applications of the fabricated biochips to material synthesis, analysis of biochemical samples, and determination of functions of microorganisms are introduced.

  20. Visualization of calcium and zinc ions in Saccharomyces cerevisiae cells treated with PEFs (pulse electric fields) by laser confocal microscopy.

    PubMed

    Urszula, Pankiewicz; Jerzy, Jamroz; Sujka, Monika; Kowalski, Radosław

    2015-12-01

    The aim of the present work was to visualize the areas of increased concentration of calcium and zinc ions inside Saccharomyces cerevisiae cells with the use of confocal microscopy and to make an attempt to asses semi-quantitatively their concentration within the limits of the cells. Semi-quantitative analysis revealed that fluorescence inside cells from control samples was three-times lower than that observed for cells from the sample enriched with calcium. Differences in distribution of fluorescence intensity between cells originated from the samples enriched with zinc and control samples were also observed. On the basis of the optical sections, the 3D reconstructions of ion-rich areas distribution in the cell were made. The obtained results showed that confocal microscopy is a useful technique for visualization of the areas in S. cerevisiae cells which contain higher amount of calcium and zinc and it may be also used for semi-quantitative analysis.

  1. Evaluation of Yogurt Microstructure Using Confocal Laser Scanning Microscopy and Image Analysis.

    PubMed

    Skytte, Jacob L; Ghita, Ovidiu; Whelan, Paul F; Andersen, Ulf; Møller, Flemming; Dahl, Anders B; Larsen, Rasmus

    2015-06-01

    The microstructure of protein networks in yogurts defines important physical properties of the yogurt and hereby partly its quality. Imaging this protein network using confocal scanning laser microscopy (CSLM) has shown good results, and CSLM has become a standard measuring technique for fermented dairy products. When studying such networks, hundreds of images can be obtained, and here image analysis methods are essential for using the images in statistical analysis. Previously, methods including gray level co-occurrence matrix analysis and fractal analysis have been used with success. However, a range of other image texture characterization methods exists. These methods describe an image by a frequency distribution of predefined image features (denoted textons). Our contribution is an investigation of the choice of image analysis methods by performing a comparative study of 7 major approaches to image texture description. Here, CSLM images from a yogurt fermentation study are investigated, where production factors including fat content, protein content, heat treatment, and incubation temperature are varied. The descriptors are evaluated through nearest neighbor classification, variance analysis, and cluster analysis. Our investigation suggests that the texton-based descriptors provide a fuller description of the images compared to gray-level co-occurrence matrix descriptors and fractal analysis, while still being as applicable and in some cases as easy to tune.

  2. Combined molecular ecological and confocal laser scanning microscopic analysis of peat bog methanogen populations.

    PubMed

    Upton, M; Hill, B; Edwards, C; Saunders, J R; Ritchie, D A; Lloyd, D

    2000-12-15

    Confocal laser scanning microscopy, using fluorescently labelled oligonucleotide probes targeting the 16S rRNA of different physiological groups of methanogens, was used to identify which methanogenic genera were present and to describe their in situ spatial locations in samples taken at different depths from blanket peat bog cores. Total bacterial DNA was also extracted and purified from the samples and used as template for amplification of 16S rRNA and regions of methyl CoM reductase-encoding genes using the polymerase chain reaction, as well as for oligonucleotide hybridisation experiments. These techniques, used in concert, demonstrated that methanogens of several physiological groups were present in highest numbers in the mid regions of 25 cm deep peat cores. Some discrepancies were apparent in the findings of the microscopic and molecular methods, though these may be partially accounted for by the different sensitivities of the techniques employed. The combined approaches used in this study gave an insight into the diversity and distribution of methanogens in peat environments not possible using molecular ecological methods alone.

  3. Three-dimensional imaging of the intact mouse cochlea by fluorescent laser scanning confocal microscopy

    PubMed Central

    MacDonald, Glen H.; Rubel, Edwin W

    2008-01-01

    The complex anatomy of the mammalian cochlea is most readily understood by representation in three-dimensions. However, the cochlea is often sectioned to minimize the effects of its anatomic complexity and optical properties on image acquisition by light microscopy. We have found that optical aberrations present in the decalcified cochlea can be greatly reduced by dehydration through graded ethanols followed by clearing with a mixture of 5 parts methyl salicylate and 3 parts benzyl benzoate (MSBB). Clearing the cochlea with MSBB enables acquisition of high-resolution images with multiple fluorescent labels, through the full volume of the cochlea by laser scanning confocal microscopy. The resulting images are readily applicable to three-dimensional morphometric analysis and volumetric visualizations. This method promises to be particularly useful for three-dimensional characterization of anatomy, innervation and expression of genes or proteins in the many new animal models of hearing and balance generated by genetic manipulation. Furthermore, the MSBB is compatible with most non-protein fluorophores used for histological labeling, and may be removed with traditional transitional solvents to allow subsequent epoxy embedding for sectioning. PMID:18573326

  4. Reflective confocal laser scanning microscopy and nonlinear microscopy of cross-linked rabbit cornea

    NASA Astrophysics Data System (ADS)

    Krueger, Alexander; Hovakimyan, Marina; Ramirez, Diego F.; Stachs, Oliver; Guthoff, Rudolf F.; Heisterkamp, Alexander

    2009-07-01

    Cross-linking of the cornea with application of Ribovlavin and UV-A light is an evolving clinical treatment of the eye disease keratoconus. Despite the positive clinical track record of corneal cross-linking, the complex wound healing process after the treatment is still under investigation. In this study an animal model was used to clarify the state of wound healing 5 weeks after treatment. Cross-linked rabbit corneae were imaged with reflective confocal laser scanning and nonlinear microscopy, namely second harmonic imaging microscopy (SHIM) and two-photon excited autofluorescence. First results show that the NAD(P) H-autofluorescence of the corneal keratocytes and their scattering signal still show a signature of the treatment five weeks after the cross-linking procedure. The SHIM signals show the structural morphology of the fibrous collagen sheets in the stroma of the cornea. SHIM detected in the forward direction differs substantially from backward SHIM, but no signature of treatment was found in both detection channels of the SHIM signal.

  5. Spatial Gradients in Particle Reinforced Polymers Characterized by X-Ray Attenuation and Laser Confocal Microscopy

    SciTech Connect

    LAGASSE,ROBERT R.; THOMPSON,KYLE R.

    2000-06-12

    The goal of this work is to develop techniques for measuring gradients in particle concentration within filled polymers, such as encapsulant. A high concentration of filler particles is added to such materials to tailor physical properties such as thermal expansion coefficient. Sedimentation and flow-induced migration of particles can produce concentration gradients that are most severe near material boundaries. Therefore, techniques for measuring local particle concentration should be accurate near boundaries. Particle gradients in an alumina-filled epoxy resin are measured with a spatial resolution of 0.2 mm using an x-ray beam attenuation technique, but an artifact related to the finite diameter of the beam reduces accuracy near the specimen's edge. Local particle concentration near an edge can be measured more reliably using microscopy coupled with image analysis. This is illustrated by measuring concentration profiles of glass particles having 40 {micro}m median diameter using images acquired by a confocal laser fluorescence microscope. The mean of the measured profiles of volume fraction agrees to better than 3% with the expected value, and the shape of the profiles agrees qualitatively with simple theory for sedimentation of monodisperse particles. Extending this microscopy technique to smaller, micron-scale filler particles used in encapsulant for microelectronic devices is illustrated by measuring the local concentration of an epoxy resin containing 0.41 volume fraction of silica.

  6. Applicability of confocal laser scanning microscopy for evaluation and monitoring of cutaneous wound healing

    NASA Astrophysics Data System (ADS)

    Lange-Asschenfeldt, Susanne; Bob, Adrienne; Terhorst, Dorothea; Ulrich, Martina; Fluhr, Joachim; Mendez, Gil; Roewert-Huber, Hans-Joachim; Stockfleth, Eggert; Lange-Asschenfeldt, Bernhard

    2012-07-01

    There is a high demand for noninvasive imaging techniques for wound assessment. In vivo reflectance confocal laser scanning microscopy (CLSM) represents an innovative optical technique for noninvasive evaluation of normal and diseased skin in vivo at near cellular resolution. This study was designed to test the feasibility of CLSM for noninvasive analysis of cutaneous wound healing in 15 patients (7 male/8 female), including acute and chronic, superficial and deep dermal skin wounds. A commercially available CLSM system was used for the assessment of wound bed and wound margins in order to obtain descriptive cellular and morphological parameters of cutaneous wound repair noninvasively and over time. CLSM was able to visualize features of cutaneous wound repair in epidermal and superficial dermal wounds, including aspects of inflammation, neovascularisation, and tissue remodelling in vivo. Limitations include the lack of mechanic fixation of the optical system on moist surfaces restricting the analysis of chronic skin wounds to the wound margins, as well as a limited optical resolution in areas of significant slough formation. By describing CLSM features of cutaneous inflammation, vascularisation, and epithelialisation, the findings of this study support the role of CLSM in modern wound research and management.

  7. Confocal laser-scanning microscopy of capillaries in normal and psoriatic skin

    NASA Astrophysics Data System (ADS)

    Archid, Rami; Patzelt, Alexa; Lange-Asschenfeldt, Bernhard; Ahmad, Sufian S.; Ulrich, Martina; Stockfleth, Eggert; Philipp, Sandra; Sterry, Wolfram; Lademann, Juergen

    2012-10-01

    An important and most likely active role in the pathogenesis of psoriasis has been attributed to changes in cutaneous blood vessels. The purpose of this study was to use confocal laser-scanning microscopy (CLSM) to investigate dermal capillaries in psoriatic and normal skin. The structures of the capillary loops in 5 healthy participants were compared with those in affected skin of 13 psoriasis patients. The diameters of the capillaries and papillae were measured for each group with CLSM. All investigated psoriasis patients showed elongated, widened, and tortuous microvessels in the papillary dermis, whereas all healthy controls showed a single capillary loop in each dermal papilla. The capillaries of the papillary loop and the dermal papilla were significantly enlarged in the psoriatic skin lesions (diameters 24.39±2.34 and 146.46±28.52 μm, respectively) in comparison to healthy skin (diameters 9.53±1.8 and 69.48±17.16 μm, respectively) (P<0.001). CLSM appears to represent a promising noninvasive technique for evaluating dermal capillaries in patients with psoriasis. The diameter of the vessels could be seen as a well-quantifiable indicator for the state of psoriatic skin. CLSM could be useful for therapeutic monitoring to delay possible recurrences.

  8. Visualization of ultradeformable liposomes penetration pathways and their skin interaction by confocal laser scanning microscopy.

    PubMed

    Subongkot, Thirapit; Wonglertnirant, Nanthida; Songprakhon, Pucharee; Rojanarata, Theerasak; Opanasopit, Praneet; Ngawhirunpat, Tanasait

    2013-01-30

    The objective of this study was to elucidate the skin penetration pathway of the generated ultradeformable liposomes (ULs) with terpenes for transdermal drug delivery of fluorescein sodium (NaFl). ULs with d-limonene were selected to investigate the penetration pathways and vesicle-skin interaction in terms of release and attachment processes via Confocal Laser Scanning Microscopy (CLSM). A co-localization technique was employed to visualize the skin penetration behavior of UL-labeled red fluorescence (Rh-PE) and fluorescence-entrapped drug (NaFl) through porcine skin. Our results suggested that ULs with entrapped drug might attach to any part of the skin before releasing the entrapped drug into the skin. Most ULs and entrapped drug penetrated through hair follicles more than through the nonfollicular region. In summary, the transfollicular pathway was the major penetration pathway of ULs with d-limonene for transdermal drug delivery of NaFl, whereas the intercellular and transcellular pathways were the minor penetration pathways.

  9. Two-dimensional confocal laser scanning microscopy image correlation for nanoparticle flow velocimetry

    NASA Astrophysics Data System (ADS)

    Jun, Brian; Giarra, Matthew; Golz, Brian; Main, Russell; Vlachos, Pavlos

    2016-11-01

    We present a methodology to mitigate the major sources of error associated with two-dimensional confocal laser scanning microscopy (CLSM) images of nanoparticles flowing through a microfluidic channel. The correlation-based velocity measurements from CLSM images are subject to random error due to the Brownian motion of nanometer-sized tracer particles, and a bias error due to the formation of images by raster scanning. Here, we develop a novel ensemble phase correlation with dynamic optimal filter that maximizes the correlation strength, which diminishes the random error. In addition, we introduce an analytical model of CLSM measurement bias error correction due to two-dimensional image scanning of tracer particles. We tested our technique using both synthetic and experimental images of nanoparticles flowing through a microfluidic channel. We observed that our technique reduced the error by up to a factor of ten compared to ensemble standard cross correlation (SCC) for the images tested in the present work. Subsequently, we will assess our framework further, by interrogating nanoscale flow in the cell culture environment (transport within the lacunar-canalicular system) to demonstrate our ability to accurately resolve flow measurements in a biological system.

  10. In vivo assessment of the structure of skin microcirculation by reflectance confocal-laser-scanning microscopy

    NASA Astrophysics Data System (ADS)

    Sugata, Keiichi; Osanai, Osamu; Kawada, Hiromitsu

    2012-02-01

    One of the major roles of the skin microcirculation is to supply oxygen and nutrition to the surrounding tissue. Regardless of the close relationship between the microcirculation and the surrounding tissue, there are few non-invasive methods that can evaluate both the microcirculation and its surrounding tissue at the same site. We visualized microcapillary plexus structures in human skin using in vivo reflectance confocal-laser-scanning microscopy (CLSM), Vivascope 3000® (Lucid Inc., USA) and Image J software (National Institutes of Health, USA) for video image processing. CLSM is a non-invasive technique that can visualize the internal structure of the skin at the cellular level. In addition to internal morphological information such as the extracellular matrix, our method reveals capillary structures up to the depth of the subpapillary plexus at the same site without the need for additional optical systems. Video images at specific depths of the inner forearm skin were recorded. By creating frame-to-frame difference images from the video images using off-line video image processing, we obtained images that emphasize the brightness depending on changes of intensity coming from the movement of blood cells. Merging images from different depths of the skin elucidates the 3-dimensional fine line-structure of the microcirculation. Overall our results show the feasibility of a non-invasive, high-resolution imaging technique to characterize the skin microcirculation and the surrounding tissue.

  11. Probe-Based Confocal Laser Endomicroscopy for Indeterminate Biliary Strictures: Refinement of the Image Interpretation Classification

    PubMed Central

    Giovannini, Marc; Jamidar, Priya; Gan, S. Ian; Cesaro, Paola; Caillol, Fabrice; Filoche, Bernard; Karia, Kunal; Smith, Ioana; Slivka, Adam

    2015-01-01

    Background. Accurate diagnosis and clinical management of indeterminate biliary strictures are often a challenge. Tissue confirmation modalities during Endoscopic Retrograde Cholangiopancreatography (ERCP) suffer from low sensitivity and poor diagnostic accuracy. Probe-based confocal laser endomicroscopy (pCLE) has been shown to be sensitive for malignant strictures characterization (98%) but lacks specificity (67%) due to inflammatory conditions inducing false positives. Methods. Six pCLE experts validated the Paris Classification, designed for diagnosing inflammatory biliary strictures, using a set of 40 pCLE sequences obtained during the prospective registry (19 inflammatory, 6 benign, and 15 malignant). The 4 criteria used included (1) multiple thin white bands, (2) dark granular pattern with scales, (3) increased space between scales, and (4) thickened reticular structures. Interobserver agreement was further calculated on a separate set of 18 pCLE sequences. Results. Overall accuracy was 82.5% (n = 40 retrospectively diagnosed) versus 81% (n = 89 prospectively collected) for the registry, resulting in a sensitivity of 81.2% (versus 98% for the prospective study) and a specificity of 83.3% (versus 67% for the prospective study). The corresponding interobserver agreement for 18 pCLE clips was fair (k = 0.37). Conclusion. Specificity of pCLE using the Paris Classification for the characterization of indeterminate bile duct stricture was increased, without impacting the overall accuracy. PMID:25866506

  12. Usefulness and Future Prospects of Confocal Laser Endomicroscopy for Gastric Premalignant and Malignant Lesions

    PubMed Central

    Lee, Sang Kil

    2015-01-01

    Confocal laser endomicroscopy (CLE) is a new technology enabling endoscopists to visualize tissue at the cellular level. CLE has the fundamental potential to provide a histologic diagnosis, and may theoretically replace or reduce the need for performing biopsy for histology. The clinical benefits of CLE are more obvious in esophageal disease, including Barrett’s esophagus. Currently, this technology has been adapted to the diagnosis and surveillance of Barrett’s esophagus and related neoplasia. Standard white light endoscopy is the primary tool for gastric cancer screening. Currently, the only method available to precisely diagnose these lesions is upper endoscopy with an appropriate biopsy. A recent study showed that CLE could characterize dysplasia or cancer and identify the risk factors for gastric cancer, such as intestinal metaplasia and the presence of Helicobacter pylori in vivo, although fewer studies on CLE were performed on the stomach than on Barrett’s esophagus and other esophageal diseases. However, the application of CLE to routine clinical endoscopy continues to be refined. This review focused on the usefulness and future prospects of CLE for gastric premalignant and malignant lesions. PMID:26668797

  13. Confocal Laser Endomicroscopy in Gastrointestinal and Pancreatobiliary Diseases: A Systematic Review and Meta-Analysis

    PubMed Central

    Fugazza, Alessandro; Gaiani, Federica; Carra, Maria Clotilde; Brunetti, Francesco; Lévy, Michaël; Sobhani, Iradj; Azoulay, Daniel; Catena, Fausto; de'Angelis, Gian Luigi; de'Angelis, Nicola

    2016-01-01

    Confocal laser endomicroscopy (CLE) is an endoscopic-assisted technique developed to obtain histopathological diagnoses of gastrointestinal and pancreatobiliary diseases in real time. The objective of this systematic review is to analyze the current literature on CLE and to evaluate the applicability and diagnostic yield of CLE in patients with gastrointestinal and pancreatobiliary diseases. A literature search was performed on MEDLINE, EMBASE, Scopus, and Cochrane Oral Health Group Specialized Register, using pertinent keywords without time limitations. Both prospective and retrospective clinical studies that evaluated the sensitivity, specificity, or accuracy of CLE were eligible for inclusion. Of 662 articles identified, 102 studies were included in the systematic review. The studies were conducted between 2004 and 2015 in 16 different countries. CLE demonstrated high sensitivity and specificity in the detection of dysplasia in Barrett's esophagus, gastric neoplasms and polyps, colorectal cancers in inflammatory bowel disease, malignant pancreatobiliary strictures, and pancreatic cysts. Although CLE has several promising applications, its use has been limited by its low availability, high cost, and need of specific operator training. Further clinical trials with a particular focus on cost-effectiveness and medicoeconomic analyses, as well as standardized institutional training, are advocated to implement CLE in routine clinical practice. PMID:26989684

  14. Optical Biopsy of Peripheral Nerve Using Confocal Laser Endomicroscopy: A New Tool for Nerve Surgeons?

    PubMed Central

    Liao, Joseph C; Curtin, Catherine M

    2015-01-01

    Peripheral nerve injuries remain a challenge for reconstructive surgeons with many patients obtaining suboptimal results. Understanding the level of injury is imperative for successful repair. Current methods for distinguishing healthy from damaged nerve are time consuming and possess limited efficacy. Confocal laser endomicroscopy (CLE) is an emerging optical biopsy technology that enables dynamic, high resolution, sub-surface imaging of live tissue. Porcine sciatic nerve was either left undamaged or briefly clamped to simulate injury. Diluted fluorescein was applied topically to the nerve. CLE imaging was performed by direct contact of the probe with nerve tissue. Images representative of both damaged and undamaged nerve fibers were collected and compared to routine H&E histology. Optical biopsy of undamaged nerve revealed bands of longitudinal nerve fibers, distinct from surrounding adipose and connective tissue. When damaged, these bands appear truncated and terminate in blebs of opacity. H&E staining revealed similar features in damaged nerve fibers. These results prompt development of a protocol for imaging peripheral nerves intraoperatively. To this end, improving surgeons' ability to understand the level of injury through real-time imaging will allow for faster and more informed operative decisions than the current standard permits. PMID:26430636

  15. Appraisal of needle-based confocal laser endomicroscopy in the diagnosis of pancreatic cysts

    PubMed Central

    Krishna, Somashekar G; Lee, Jeffery H

    2016-01-01

    Nearly 2.5% of cross-sectional imaging studies will report a finding of a cystic pancreatic lesion. Even though most of these are incidental findings, it remains very concerning for both patients and treating clinicians. Differentiating and predicting malignant transformation in pancreatic cystic lesions is clinically challenging. Current evaluation of suspicious cystic lesions includes a combination of radiologic imaging, endoscopic ultrasound (EUS) and cyst fluid analyses. Despite these attempts, precise diagnostic stratification among non-mucinous, mucinous, and malignant cystic lesions is often not possible until surgical resection. EUS-guided needle based confocal laser endomicroscopy (nCLE) for evaluation of pancreatic cysts is emerging as a powerful technique with remarkable potential. Though limited imaging data from 3 large clinical trials (INSPECT, DETECT and CONTACT) are currently the reference standard for nCLE imaging, nonetheless these have not been validated in large studies. The aim of this review article is to review the evolving role of EUS-guided nCLE in management of pancreatic cystic lesions in terms of its significance, adverse events, limitations, and implications. PMID:26819534

  16. Laser scanning confocal microscopy for in situ monitoring of alkali-silica reaction.

    PubMed

    Collins, C L; Ideker, J H; Kurtis, K E

    2004-02-01

    Alkali-silica reaction (ASR) occurs in concrete between reactive siliceous components in the aggregate and the strongly alkaline pore solution, resulting in the formation of a potentially expansive gel product. Lithium additives have been shown to reduce expansion associated with ASR, but the mechanism(s) by which lithium reduces expansion have not been understood. Therefore, development of an in situ method to observe reactions associated with ASR is highly desirable, as it will allow for non-destructive observation of the reaction product formation and damage evolution over time, as the reaction progresses. A technique to image into mortar through glass aggregate by laser scanning confocal microscopy (LSCM), producing three-dimensional representations of the sample was developed. This LSCM technique was utilized to monitor the progress of alkali-silica reaction in mortar samples prepared with alkali-reactive glass aggregate both in the presence and in the absence of lithium additives: LiNO3, LiCl or LiOH. The method proved to be effective in qualitatively monitoring crack formation and growth and product formation, within cracks and at the paste/aggregate interface. In particular, dendritic products were observed at the paste/aggregate interface only in those samples containing lithium, suggesting that these products may play a role in ASR mitigation.

  17. Visualization and quantification of healthy and carious dentin structure using confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Kimura, Yuichi; Wilder-Smith, Petra B. B.; Krasieva, Tatiana B.; Arrastia-Jitosho, Anna-Marie A.; Liaw, Lih-Huei L.; Matsumoto, Koukichi; Berns, Michael W.

    1996-04-01

    In this study, a fluorescence technique was developed for visualization of dentin using confocal laser scanning microscopy (CLSM). Eighteen extracted human teeth were used: 13 showing no clinical signs of caries and 5 with visually apparent decay. Preliminary study: All teeth were horizontally sectioned to approx. 200 micrometers thickness and pre-treated as follows: no pretreatment; vacuum only; ultrasonication only; sodium hypochlorite (NaOCl) only; vacuum and NaOCl; ultrasonication and NaOCl; or vacuum, ultrasonication and NaOCl. Samples were stained with Rhodamine 123 fluorescent dye at a concentration of 10-5 M in phosphate buffer saline for 1 to 24 hours. Caries study: Dentin surfaces, some with pre-existing caries, were visualized using CLSM. Most dentin tubules in sound dentin appeared open using CLSM, but most dentin tubules in carious dentin appeared closed or narrowed. Surface images obtained using CLSM were similar to those seen by SEM, but additional subsurface imaging was possible using CLSM at depth intervals of 1 micrometers to a depth of 30 - 50 micrometers . This technique shows good potential for non-invasive surface and subsurface imaging of dentin structures.

  18. Elastomeric photo-actuators and their investigation by confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Czaniková, Klaudia; Ilčíková, Markéta; Krupa, Igor; Mičušík, Matej; Kasák, Peter; Pavlova, Ewa; Mosnáček, Jaroslav; Chorvát, Dušan, Jr.; Omastová, Mária

    2013-10-01

    The photo-actuation behavior of nanocomposites based on ethylene-vinylacetate copolymer (EVA) and styrene-isoprene-styrene (SIS) block copolymer filled with well-dispersed and modified multiwalled carbon nanotubes (MWCNTs) is discussed in this paper. The nanocomposites were prepared by casting from solution. To improve the dispersion of the MWCNTs in EVA, the MWCNT surface was modified with a non-covalent surfactant, cholesteryl 1-pyrenecarboxylate (PyChol). To prepare SIS nanocomposites, the MWCNT surface was covalently modified with polystyrene chains. The good dispersion of the filler was confirmed by transmission electron microscopy (TEM). Special, custom-made punch/die molds were used to create a Braille element (BE)-like shape, which under shear forces induces a uniaxial orientation of the MWCNTs within the matrix. The uniaxial orientation of MWCNTs is an essential precondition to ensure the photo-actuating behavior of MWCNTs in polymeric matrices. The orientation of the MWCNTs within the matrices was examined by scanning electron microscopy (SEM). Nanocomposite BEs were illuminated from the bottom by a red light-emitting diode (LED), and the photo-actuation was investigated by confocal laser scanning microscopy (CLSM). When the BEs were exposed to light, a temporary increase in the height of the element was detected. This process was observed to be reversible: after switching off the light, the BEs returned to their original shape and height.

  19. Laser-wakefield accelerators as hard x-ray sources for 3D medical imaging of human bone.

    PubMed

    Cole, J M; Wood, J C; Lopes, N C; Poder, K; Abel, R L; Alatabi, S; Bryant, J S J; Jin, A; Kneip, S; Mecseki, K; Symes, D R; Mangles, S P D; Najmudin, Z

    2015-08-18

    A bright μm-sized source of hard synchrotron x-rays (critical energy Ecrit > 30 keV) based on the betatron oscillations of laser wakefield accelerated electrons has been developed. The potential of this source for medical imaging was demonstrated by performing micro-computed tomography of a human femoral trabecular bone sample, allowing full 3D reconstruction to a resolution below 50 μm. The use of a 1 cm long wakefield accelerator means that the length of the beamline (excluding the laser) is dominated by the x-ray imaging distances rather than the electron acceleration distances. The source possesses high peak brightness, which allows each image to be recorded with a single exposure and reduces the time required for a full tomographic scan. These properties make this an interesting laboratory source for many tomographic imaging applications.

  20. Laser-wakefield accelerators as hard x-ray sources for 3D medical imaging of human bone

    PubMed Central

    Cole, J. M.; Wood, J. C.; Lopes, N. C.; Poder, K.; Abel, R. L.; Alatabi, S.; Bryant, J. S. J.; Jin, A.; Kneip, S.; Mecseki, K.; Symes, D. R.; Mangles, S. P. D.; Najmudin, Z.

    2015-01-01

    A bright μm-sized source of hard synchrotron x-rays (critical energy Ecrit > 30 keV) based on the betatron oscillations of laser wakefield accelerated electrons has been developed. The potential of this source for medical imaging was demonstrated by performing micro-computed tomography of a human femoral trabecular bone sample, allowing full 3D reconstruction to a resolution below 50 μm. The use of a 1 cm long wakefield accelerator means that the length of the beamline (excluding the laser) is dominated by the x-ray imaging distances rather than the electron acceleration distances. The source possesses high peak brightness, which allows each image to be recorded with a single exposure and reduces the time required for a full tomographic scan. These properties make this an interesting laboratory source for many tomographic imaging applications. PMID:26283308

  1. Distribution of ALA metabolic products in esophageal carcinoma cells using spectrally resolved confocal laser microscopy

    NASA Astrophysics Data System (ADS)

    Smolka, Jozef; Mateasik, Anton

    2006-08-01

    Aminolevulinic acid (ALA) is an efficient substance used in photodynamic therapy (PDT). It is a precursor of light-sensitive products that can selectively accumulate in malignant cells following the altered activity of the heme biosynthetic pathway enzymes in such cells. These products are synthesized in mitochondria and distributed to various cellular structures [1]. The localization of ALA products in subcellular structures depends on their chemical characteristics as well as on the properties of the intracellular environment [2]. Characterization of such properties is possible by means of fluorescent probes like JC-1 and carboxy SNARF-1. However, the emission spectra of these probes are overlapped with spectral pattern of typical ALA product -protoporphyrin IX (PpIX). Spectral overlap of fluorescence signals prevents to clearly separate a distribution of probes from PpIX distribution what can completely mess the applicability of these probes in characterization of cell properties. The spectrally resolved confocal laser microscopy can be used to overcome this problem. In this study, a distribution of ALA metabolic products in relation to the mitochondrial membrane potential and intracellular pH was examined. Human cell lines (KYSE-450, KYSE-70) from esophageal squamous cell carcinoma were used. Cells were incubated with 1mM solution of ALA for four hours. Two fluorescent probes, carboxy SNARF-1 and JC-1 , were used to monitor intracellular pH levels and to determine membrane potential changes, respectively. The samples were scanned by spectrally resolved laser scanning microscope. Spectral linear unmixing method was used to discriminate and separate regions of accumulation of ALA metabolic products of JC-1 and carboxy SNARF-1.

  2. Confocal microscopy in microgravity research.

    PubMed

    Goede, A P; Brakenhoff, G J; Woldringh, C L; Aalders, J W; Imhof, J P; van Kralingen, P; Mels, W A; Schreinemakers, P; Zegers, A

    1992-01-01

    We have studied the application and the feasibility of confocal scanning laser microscopy (CSLM) in microgravity research. Its superior spatial resolution and 3D imaging capabilities and its use of light as a probe, render this instrument ideally suited for the study of living biological material on a (sub-)cellular level. In this paper a number of pertinent biological microgravity experiments is listed, concentrating on the direct observation of developing cells and cellular structures under microgravity condition. A conceptual instrument design is also presented, aimed at sounding rocket application followed by Biorack/Biolab application at a later stage.

  3. 3D printed facial laser scans for the production of localised radiotherapy treatment masks - A case study.

    PubMed

    Briggs, Matthew; Clements, Helen; Wynne, Neil; Rennie, Allan; Kellett, Darren

    This study investigates the use of 3D printing for patients that require localised radiotherapy treatment to the face. The current process involves producing a lead mask in order to protect the healthy tissue from the effects of the radiotherapy. The mask is produced by applying a thermoplastic sheet to the patient's face and allowing to set hard. This can then be used as a mould to create a plaster impression of the patient's face. A sheet of lead is then hammered on to the plaster to create a bespoke fitted face mask. This process can be distressing for patients and can be problematic when the patient is required to remain motionless for a prolonged time while the thermoplastic sets. In this study, a 1:1 scale 3D print of a patient's face was generated using a laser scanner. The lead was hammered directly on to the surface of the 3D print in order to create a bespoke fitted treatment mask. This eliminated the thermoplastic moulding stage and significantly reduced the time needed for the patient to be in clinic. The higher definition impression of the the face resulted in a more accurate, better fitting treatment mask.

  4. Semi-automated extraction and delineation of 3D roads of street scene from mobile laser scanning point clouds

    NASA Astrophysics Data System (ADS)

    Yang, Bisheng; Fang, Lina; Li, Jonathan

    2013-05-01

    Accurate 3D road information is important for applications such as road maintenance and virtual 3D modeling. Mobile laser scanning (MLS) is an efficient technique for capturing dense point clouds that can be used to construct detailed road models for large areas. This paper presents a method for extracting and delineating roads from large-scale MLS point clouds. The proposed method partitions MLS point clouds into a set of consecutive "scanning lines", which each consists of a road cross section. A moving window operator is used to filter out non-ground points line by line, and curb points are detected based on curb patterns. The detected curb points are tracked and refined so that they are both globally consistent and locally similar. To evaluate the validity of the proposed method, experiments were conducted using two types of street-scene point clouds captured by Optech's Lynx Mobile Mapper System. The completeness, correctness, and quality of the extracted roads are over 94.42%, 91.13%, and 91.3%, respectively, which proves the proposed method is a promising solution for extracting 3D roads from MLS point clouds.

  5. Laser scanner data processing and 3D modeling using a free and open source software

    SciTech Connect

    Gabriele, Fatuzzo; Michele, Mangiameli Giuseppe, Mussumeci; Salvatore, Zito

    2015-03-10

    The laser scanning is a technology that allows in a short time to run the relief geometric objects with a high level of detail and completeness, based on the signal emitted by the laser and the corresponding return signal. When the incident laser radiation hits the object to detect, then the radiation is reflected. The purpose is to build a three-dimensional digital model that allows to reconstruct the reality of the object and to conduct studies regarding the design, restoration and/or conservation. When the laser scanner is equipped with a digital camera, the result of the measurement process is a set of points in XYZ coordinates showing a high density and accuracy with radiometric and RGB tones. In this case, the set of measured points is called “point cloud” and allows the reconstruction of the Digital Surface Model. Even the post-processing is usually performed by closed source software, which is characterized by Copyright restricting the free use, free and open source software can increase the performance by far. Indeed, this latter can be freely used providing the possibility to display and even custom the source code. The experience started at the Faculty of Engineering in Catania is aimed at finding a valuable free and open source tool, MeshLab (Italian Software for data processing), to be compared with a reference closed source software for data processing, i.e. RapidForm. In this work, we compare the results obtained with MeshLab and Rapidform through the planning of the survey and the acquisition of the point cloud of a morphologically complex statue.

  6. 3D analysis of thermal and stress evolution during laser cladding of bioactive glass coatings.

    PubMed

    Krzyzanowski, Michal; Bajda, Szymon; Liu, Yijun; Triantaphyllou, Andrew; Mark Rainforth, W; Glendenning, Malcolm

    2016-06-01

    Thermal and strain-stress transient fields during laser cladding of bioactive glass coatings on the Ti6Al4V alloy basement were numerically calculated and analysed. Conditions leading to micro-cracking susceptibility of the coating have been investigated using the finite element based modelling supported by experimental results of microscopic investigation of the sample coatings. Consecutive temperature and stress peaks are developed within the cladded material as a result of the laser beam moving along the complex trajectory, which can lead to micro-cracking. The preheated to 500°C base plate allowed for decrease of the laser power and lowering of the cooling speed between the consecutive temperature peaks contributing in such way to achievement of lower cracking susceptibility. The cooling rate during cladding of the second and the third layer was lower than during cladding of the first one, in such way, contributing towards improvement of cracking resistance of the subsequent layers due to progressive accumulation of heat over the process.

  7. 3D model for laser heating of a heterogeneous turbid medium

    NASA Astrophysics Data System (ADS)

    Rossacci, Michael J.; DiMarzio, Charles A.; Lindberg, Scott C.; Pankratov, Michail M.

    1997-05-01

    In order to better understand the interaction of laser light with biological tissue, a light-transport model is integrated with a heat-transport model. The outputs include temperature as a function of position and time, given the illumination conditions and the optical and thermal properties of the tissue. The optical portion of the algorithm is based on the theory of radiative transfer through a turbid medium. Our computer program models multiple scattering in three dimensions using seven discrete irradiances which approximate the radiative transport equation. The distribution of absorbed light in the tissue is calculated and used as the source term in a discrete approximation to the thermal diffusion equation. Recently, we have been using the model to better understand the laser-heating of heterogeneous tissue. Rather than modeling a homogeneous mixture having properties given by weighted averages of those of tissue and blood, we model this medium as an array of blood vessels in a bloodless dermis background. We are currently analyzing temporal and spatial variations of temperature in homogeneous and heterogeneous tissue having identical blood concentrations. A particular application of the model is to the study of laser coagulation tonsillectomy.

  8. Fabrication of 3D components by laser-aided direct metal deposition

    NASA Astrophysics Data System (ADS)

    Mazumder, Jyotirmoy; Qi, Huan

    2005-03-01

    Breinan and Kear first reported fabrication of three-dimensional metallic components via layer by layer laser cladding in 1978 and subsequently a patent was issued to Brown et al. in 1982. Recently, various groups are working world wide on different types of layered manufacturing techniques for fabrication of near net shape metallic components. Integration of lasers with multi-axis presently available CNC machines, CAD/CAM, sensors and powder metal delivery through co-axial nozzles along with the laser beam are the main innovations for fabrication of 3-Dimensional components. Continuous corrective measures during the manufacturing process are necessary to fabricate net shape functional parts with close tolerances and acceptable residual stress. The closed loop Direct Metal Deposition(DMD) System, using an optical feedback loop along with a CNC working under the instructions from a CAD/CAM software, indicate that it can produce three dimensional components directly from the CAD data eliminating intermediate machining and reduces final machining considerably. This technology is now being commercialized.

  9. A fast 3D image simulation algorithm of moving target for scanning laser radar

    NASA Astrophysics Data System (ADS)

    Li, Jicheng; Shi, Zhiguang; Chen, Xiao; Chen, Dong

    2014-10-01

    Scanning Laser Radar has been widely used in many military and civil areas. Usually there are relative movements between the target and the radar, so the moving target image modeling and simulation is an important research content in the field of signal processing and system design of scan-imaging laser radar. In order to improve the simulation speed and hold the accuracy of the image simulation simultaneously, a novel fast simulation algorithm is proposed in this paper. Firstly, for moving target or varying scene, an inequation that can judge the intersection relations between the pixel and target bins is obtained by deriving the projection of target motion trajectories on the image plane. Then, by utilizing the time subdivision and approximate treatments, the potential intersection relations of pixel and target bins are determined. Finally, the goal of reducing the number of intersection operations could be achieved by testing all the potential relations and finding which of them is real intersection. To test the method's performance, we perform computer simulations of both the new proposed algorithm and a literature's algorithm for six targets. The simulation results show that the two algorithm yield the same imaging result, whereas the number of intersection operations of former is equivalent to only 1% of the latter, and the calculation efficiency increases a hundredfold. The novel simulation acceleration idea can be applied extensively in other more complex application environments and provide equally acceleration effect. It is very suitable for the case to produce a great large number of laser radar images.

  10. New laser driver for physics modeling codes using unstructured 3d grids

    SciTech Connect

    Kaiser, T; Milovich, J L; Prasad, M K; Shestakov, A I

    1999-02-01

    We present a status report on the current state of development, testing and application of a new scheme for laser beam evolution and power deposition on three-dimensional unstructured grids. The scheme is being encapsulated in a C++ library for convenient porting to existing modeling codes. We have added a new ray propagator that is second order in time, allowing rays to refract within computational zones as well as at zone interfaces. In a globally constant free-electron density gradient on a randomized hexahedral mesh,the new integrator produces ray trajectories that agree with analytic results to within machine roundoff. A new method for computing the inverse-bremmstrahlung energy deposition rate that captures its highly non-uniform spatial dependence within a zone has also been added. This allows accurate trajectories without the necessity of sub-stepping in time. Other enhancements (not discussed) include multiple user-configurable beams, computation of the electron oscillation velocity in the laser electric field and energy-deposition accounting. Results of laser-driven simulations are presented in a companion paper.

  11. Estimation of regeneration coverage in a temperate forest by 3D segmentation using airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Amiri, Nina; Yao, Wei; Heurich, Marco; Krzystek, Peter; Skidmore, Andrew K.

    2016-10-01

    Forest understory and regeneration are important factors in sustainable forest management. However, understanding their spatial distribution in multilayered forests requires accurate and continuously updated field data, which are difficult and time-consuming to obtain. Therefore, cost-efficient inventory methods are required, and airborne laser scanning (ALS) is a promising tool for obtaining such information. In this study, we examine a clustering-based 3D segmentation in combination with ALS data for regeneration coverage estimation in a multilayered temperate forest. The core of our method is a two-tiered segmentation of the 3D point clouds into segments associated with regeneration trees. First, small parts of trees (super-voxels) are constructed through mean shift clustering, a nonparametric procedure for finding the local maxima of a density function. In the second step, we form a graph based on the mean shift clusters and merge them into larger segments using the normalized cut algorithm. These segments are used to obtain regeneration coverage of the target plot. Results show that, based on validation data from field inventory and terrestrial laser scanning (TLS), our approach correctly estimates up to 70% of regeneration coverage across the plots with different properties, such as tree height and tree species. The proposed method is negatively impacted by the density of the overstory because of decreasing ground point density. In addition, the estimated coverage has a strong relationship with the overstory tree species composition.

  12. Guided wave-based J-integral estimation for dynamic stress intensity factors using 3D scanning laser Doppler vibrometry

    NASA Astrophysics Data System (ADS)

    Ayers, J.; Owens, C. T.; Liu, K. C.; Swenson, E.; Ghoshal, A.; Weiss, V.

    2013-01-01

    The application of guided waves to interrogate remote areas of structural components has been researched extensively in characterizing damage. However, there exists a sparsity of work in using piezoelectric transducer-generated guided waves as a method of assessing stress intensity factors (SIF). This quantitative information enables accurate estimation of the remaining life of metallic structures exhibiting cracks, such as military and commercial transport vehicles. The proposed full wavefield approach, based on 3D laser vibrometry and piezoelectric transducer-generated guided waves, provides a practical means for estimation of dynamic stress intensity factors (DSIF) through local strain energy mapping via the J-integral. Strain energies and traction vectors can be conveniently estimated from wavefield data recorded using 3D laser vibrometry, through interpolation and subsequent spatial differentiation of the response field. Upon estimation of the Jintegral, it is possible to obtain the corresponding DSIF terms. For this study, the experimental test matrix consists of aluminum plates with manufactured defects representing canonical elliptical crack geometries under uniaxial tension that are excited by surface mounted piezoelectric actuators. The defects' major to minor axes ratios vary from unity to approximately 133. Finite element simulations are compared to experimental results and the relative magnitudes of the J-integrals are examined.

  13. Documentation and Visualization of AN As-Built Tunnel by Combining 3d Laser Scanning and Web Mapping

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Arditi, D.; Chen, Z.

    2013-08-01

    A new way to document and visualize the as-built condition of an urban tunnel project with high accuracy is described in this paper, based on recent developments of laser scanning technology. In traditional surveying, the components of a tunnel are organized on the basis of the location of stations and offsets along the project alignment specified in the drawings. It is difficult for people without an engineering background to understand the information involved in surveying reports, drawings, and engineering data. However, in the interest of transparency, public agencies that commission construction projects have to make project information available to government officials and to the general public. This paper discusses the combined use of laser scanning technology and web mapping services to improve the documentation and visualization of an urban metro tunnel. Laser scanning technology is introduced to perform the surveyor's task, document the as-built condition, and geo-reference the construction elements. A set of panoramic pictures is generated by laser scanning that allows for taking measurements and extracting 3D coordinates. An XML file that contains geo-reference information is appended to each panoramic picture. Using application programming interface (API), this information is referenced to a web mapping service. A case study of the CTA Red line Tunnel in Chicago, IL demonstrates this method in a real life project.

  14. 3D noninvasive, high-resolution imaging using a photoacoustic tomography (PAT) system and rapid wavelength-cycling lasers

    NASA Astrophysics Data System (ADS)

    Sampathkumar, Ashwin; Gross, Daniel; Klosner, Marc; Chan, Gary; Wu, Chunbai; Heller, Donald F.

    2015-05-01

    Globally, cancer is a major health issue as advances in modern medicine continue to extend the human life span. Breast cancer ranks second as a cause of cancer death in women in the United States. Photoacoustic (PA) imaging (PAI) provides high molecular contrast at greater depths in tissue without the use of ionizing radiation. In this work, we describe the development of a PA tomography (PAT) system and a rapid wavelength-cycling Alexandrite laser designed for clinical PAI applications. The laser produces 450 mJ/pulse at 25 Hz to illuminate the entire breast, which eliminates the need to scan the laser source. Wavelength cycling provides a pulse sequence in which the output wavelength repeatedly alternates between 755 nm and 797 nm rapidly within milliseconds. We present imaging results of breast phantoms with inclusions of different sizes at varying depths, obtained with this laser source, a 5-MHz 128-element transducer and a 128-channel Verasonics system. Results include PA images and 3D reconstruction of the breast phantom at 755 and 797 nm, delineating the inclusions that mimic tumors in the breast.

  15. Direct laser-writing of ferroelectric single-crystal waveguide architectures in glass for 3D integrated optics

    PubMed Central

    Stone, Adam; Jain, Himanshu; Dierolf, Volkmar; Sakakura, Masaaki; Shimotsuma, Yasuhiko; Miura, Kiyotaka; Hirao, Kazuyuki; Lapointe, Jerome; Kashyap, Raman

    2015-01-01

    Direct three-dimensional laser writing of amorphous waveguides inside glass has been studied intensely as an attractive route for fabricating photonic integrated circuits. However, achieving essential nonlinear-optic functionality in such devices will also require the ability to create high-quality single-crystal waveguides. Femtosecond laser irradiation is capable of crystallizing glass in 3D, but producing optical-quality single-crystal structures suitable for waveguiding poses unique challenges that are unprecedented in the field of crystal growth. In this work, we use a high angular-resolution electron diffraction method to obtain the first conclusive confirmation that uniform single crystals can be grown inside glass by femtosecond laser writing under optimized conditions. We confirm waveguiding capability and present the first quantitative measurement of power transmission through a laser-written crystal-in-glass waveguide, yielding loss of 2.64 dB/cm at 1530 nm. We demonstrate uniformity of the crystal cross-section down the length of the waveguide and quantify its birefringence. Finally, as a proof-of-concept for patterning more complex device geometries, we demonstrate the use of dynamic phase modulation to grow symmetric crystal junctions with single-pass writing. PMID:25988599

  16. Mobile connected dermatoscope and confocal laser scanning microscope: a useful combination applied in facial simple sensitive skin.

    PubMed

    Zha, W F; Song, W M; Ai, J J; Xu, A E

    2012-08-01

    Little is known as the effects of mobile connected dermatoscope services on diagnostic accuracy for sensitive skin. Confocal laser scanning microscope (CLSM) can non-invasively measure the thickness of epidermis. Combination of the two devices to observe sensitive skin may receive unexpected effects. To evaluate the application effect on sensitive skin with the combination of Handyscope and confocal laser scanning microscope. Twenty simple sensitive-skinned patients and 20 volunteers participated in the study. Cheek, typically, dermoscopic images were obtained from patients, and the changes in the skin texture were observed. Their epidermis thicknesses as well as the volunteers' were measured so that the thicknesses of the two groups were compared. Dermoscopic pictures of the skin texture obviously showed that dilated capillaries looked like earthworms with pigmented patches more or less floating above, and skin roughness as well as deepened dermatoglyph were also conspicuously present in some patients. The mean epidermal thickness of the patients was 79.01 μm and the volunteers' was 85.78 μm. The difference between the two groups reached 6.77 μm. There was a statistical significance (P = 0.001). Mobile connected dermatoscope and confocal laser scanning microscope might be the choice for simple sensitive skin investigation.

  17. Cytosolic pH gradients in cultured neuronal cell lines studied by laser scanning confocal microscopy, real-time confocal microscopy, and spectral imaging microscopy

    NASA Astrophysics Data System (ADS)

    Sanchez-Armass, Sergio; Sennoune, Souad; Martinez, Gloria M.; Ortega, Filiberta; Martinez-Zaguilan, Raul

    2002-06-01

    Changes in intracellular pH are important for the regulation of many physiological processes including: cell growth and differentiation, exocytosis, synaptic transmission, cell motility and invasion, to name a few. In pathological states such as cancer and diabetes, pH regulation is known to be altered. Nevertheless the physiological and pathological significance of this ion, there are still many gaps in our knowledge. The advent of fluorescent pH probes to monitor this ion, has substantially accelerated its study. New advances in the methods of detection of this ion by fluorescence-based approaches have also helped us to understand more about the regulation of cytosolic pH. This study evaluates the usefulness of real time confocal imaging microscopy, laser scanning confocal microscopy, and spectral imaging microscopy to the study of pH. These approaches exhibit unsurpassed temporal, spatial, and spectral resolution and are complementary. We employed cell lines derived from the brain exhibiting soma and dendrites. The existence of cell polarity suggests that the different protein composition/micro environment in discrete subcellular domains may affect the properties of fluorescent ion indicators. We performed in situ calibration of pH probes in discrete cellular regions of the neuronal cell lines to eliminate any bias in data interpretation because of differences in cell thickness/micro environment. We show that there are distinct in situ calibration parameters in different cellular domains. These indicate that in situ titrations in discrete cellular domains are needed to assign pH values. We concluded that there are distinct pH micro domains in discrete cellular regions of neuronal cell lines.

  18. Three-dimensional recording of the human face with a 3D laser scanner.

    PubMed

    Kovacs, L; Zimmermann, A; Brockmann, G; Gühring, M; Baurecht, H; Papadopulos, N A; Schwenzer-Zimmerer, K; Sader, R; Biemer, E; Zeilhofer, H F

    2006-01-01

    Three-dimensional recording of the surface of the human body or of certain anatomical areas has gained an ever increasing importance in recent years. When recording living surfaces, such as the human face, not only has a varying degree of surface complexity to be accounted for, but also a variety of other factors, such as motion artefacts. It is of importance to establish standards for the recording procedure, which will optimise results and allow for better comparison and validation. In the study presented here, the faces of five male test persons were scanned in different experimental settings using non-contact 3D digitisers, type Minolta Vivid 910). Among others, the influence of the number of scanners used, the angle of recording, the head position of the test person, the impact of the examiner and of examination time on accuracy and precision of the virtual face models generated from the scanner data with specialised software were investigated. Computed data derived from the virtual models were compared to corresponding reference measurements carried out manually between defined landmarks on the test persons' faces. We describe experimental conditions that were of benefit in optimising the quality of scanner recording and the reliability of three-dimensional surface imaging. However, almost 50% of distances between landmarks derived from the virtual models deviated more than 2mm from the reference of manual measurements on the volunteers' faces.

  19. Wavelength-scale light concentrator made by direct 3D laser writing of polymer metamaterials.

    PubMed

    Moughames, J; Jradi, S; Chan, T M; Akil, S; Battie, Y; Naciri, A En; Herro, Z; Guenneau, S; Enoch, S; Joly, L; Cousin, J; Bruyant, A

    2016-10-04

    We report on the realization of functional infrared light concentrators based on a thick layer of air-polymer metamaterial with controlled pore size gradients. The design features an optimum gradient index profile leading to light focusing in the Fresnel zone of the structures for two selected operating wavelength domains near 5.6 and 10.4 μm. The metamaterial which consists in a thick polymer containing air holes with diameters ranging from λ/20 to λ/8 is made using a 3D lithography technique based on the two-photon polymerization of a homemade photopolymer. Infrared imaging of the structures reveals a tight focusing for both structures with a maximum local intensity increase by a factor of 2.5 for a concentrator volume of 1.5 λ(3), slightly limited by the residual absorption of the selected polymer. Such porous and flat metamaterial structures offer interesting perspectives to increase infrared detector performance at the pixel level for imaging or sensing applications.

  20. Feature-constrained surface reconstruction approach for point cloud data acquired with 3D laser scanner

    NASA Astrophysics Data System (ADS)

    Wang, Yongbo; Sheng, Yehua; Lu, Guonian; Tian, Peng; Zhang, Kai

    2008-04-01

    Surface reconstruction is an important task in the field of 3d-GIS, computer aided design and computer graphics (CAD & CG), virtual simulation and so on. Based on available incremental surface reconstruction methods, a feature-constrained surface reconstruction approach for point cloud is presented. Firstly features are extracted from point cloud under the rules of curvature extremes and minimum spanning tree. By projecting local sample points to the fitted tangent planes and using extracted features to guide and constrain the process of local triangulation and surface propagation, topological relationship among sample points can be achieved. For the constructed models, a process named consistent normal adjustment and regularization is adopted to adjust normal of each face so that the correct surface model is achieved. Experiments show that the presented approach inherits the convenient implementation and high efficiency of traditional incremental surface reconstruction method, meanwhile, it avoids improper propagation of normal across sharp edges, which means the applicability of incremental surface reconstruction is greatly improved. Above all, appropriate k-neighborhood can help to recognize un-sufficient sampled areas and boundary parts, the presented approach can be used to reconstruct both open and close surfaces without additional interference.