Science.gov

Sample records for 3d optical surface

  1. 3D Human cartilage surface characterization by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Brill, Nicolai; Riedel, Jörn; Schmitt, Robert; Tingart, Markus; Truhn, Daniel; Pufe, Thomas; Jahr, Holger; Nebelung, Sven

    2015-10-01

    Early diagnosis and treatment of cartilage degeneration is of high clinical interest. Loss of surface integrity is considered one of the earliest and most reliable signs of degeneration, but cannot currently be evaluated objectively. Optical Coherence Tomography (OCT) is an arthroscopically available light-based non-destructive real-time imaging technology that allows imaging at micrometre resolutions to millimetre depths. As OCT-based surface evaluation standards remain to be defined, the present study investigated the diagnostic potential of 3D surface profile parameters in the comprehensive evaluation of cartilage degeneration. To this end, 45 cartilage samples of different degenerative grades were obtained from total knee replacements (2 males, 10 females; mean age 63.8 years), cut to standard size and imaged using a spectral-domain OCT device (Thorlabs, Germany). 3D OCT datasets of 8  ×  8, 4  ×  4 and 1  ×  1 mm (width  ×  length) were obtained and pre-processed (image adjustments, morphological filtering). Subsequent automated surface identification algorithms were used to obtain the 3D primary profiles, which were then filtered and processed using established algorithms employing ISO standards. The 3D surface profile thus obtained was used to calculate a set of 21 3D surface profile parameters, i.e. height (e.g. Sa), functional (e.g. Sk), hybrid (e.g. Sdq) and segmentation-related parameters (e.g. Spd). Samples underwent reference histological assessment according to the Degenerative Joint Disease classification. Statistical analyses included calculation of Spearman’s rho and assessment of inter-group differences using the Kruskal Wallis test. Overall, the majority of 3D surface profile parameters revealed significant degeneration-dependent differences and correlations with the exception of severe end-stage degeneration and were of distinct diagnostic value in the assessment of surface integrity. None of the 3D

  2. Active optical system for advanced 3D surface structuring by laser remelting

    NASA Astrophysics Data System (ADS)

    Pütsch, O.; Temmler, A.; Stollenwerk, J.; Willenborg, E.; Loosen, P.

    2015-03-01

    Structuring by laser remelting enables completely new possibilities for designing surfaces since material is redistributed but not wasted. In addition to technological advantages, cost and time benefits yield from shortened process times, the avoidance of harmful chemicals and the elimination of subsequent finishing steps such as cleaning and polishing. The functional principle requires a completely new optical machine technology that maintains the spatial and temporal superposition and manipulation of three different laser beams emitted from two laser sources of different wavelength. The optical system has already been developed and demonstrated for the processing of flat samples of hot and cold working steel. However, since particularly the structuring of 3D-injection molds represents an application example of high innovation potential, the optical system has to take into account the elliptical beam geometry that occurs when the laser beams irradiate a curved surface. To take full advantage of structuring by remelting for the processing of 3D surfaces, additional optical functionality, called EPS (elliptical pre-shaping) has to be integrated into the existing set-up. The development of the beam shaping devices not only requires the analysis of the mechanisms of the beam projection but also a suitable optical design. Both aspects are discussed in this paper.

  3. Optically Trapped Surface-Enhanced Raman Probes Prepared by Silver Photoreduction to 3D Microstructures.

    PubMed

    Vizsnyiczai, Gaszton; Lestyán, Tamás; Joniova, Jaroslava; Aekbote, Badri L; Strejčková, Alena; Ormos, Pál; Miskovsky, Pavol; Kelemen, Lóránd; Bánó, Gregor

    2015-09-15

    3D microstructures partially covered by silver nanoparticles have been developed and tested for surface-enhanced Raman spectroscopy (SERS) in combination with optical tweezers. The microstructures made by two-photon polymerization of SU-8 photoresist were manipulated in a dual beam optical trap. The active area of the structures was covered by a SERS-active silver layer using chemically assisted photoreduction from silver nitrate solutions. Silver layers of different grain size distributions were created by changing the photoreduction parameters and characterized by scanning electron microscopy. The structures were tested by measuring the SERS spectra of emodin and hypericin.

  4. Extended volume and surface scatterometer for optical characterization of 3D-printed elements

    NASA Astrophysics Data System (ADS)

    Dannenberg, Florian; Uebeler, Denise; Weiß, Jürgen; Pescoller, Lukas; Weyer, Cornelia; Hahlweg, Cornelius

    2015-09-01

    The use of 3d printing technology seems to be a promising way for low cost prototyping, not only of mechanical, but also of optical components or systems. It is especially useful in applications where customized equipment repeatedly is subject to immediate destruction, as in experimental detonics and the like. Due to the nature of the 3D-printing process, there is a certain inner texture and therefore inhomogeneous optical behaviour to be taken into account, which also indicates mechanical anisotropy. Recent investigations are dedicated to quantification of optical properties of such printed bodies and derivation of corresponding optimization strategies for the printing process. Beside mounting, alignment and illumination means, also refractive and reflective elements are subject to investigation. The proposed measurement methods are based on an imaging nearfield scatterometer for combined volume and surface scatter measurements as proposed in previous papers. In continuation of last year's paper on the use of near field imaging, which basically is a reflective shadowgraph method, for characterization of glossy surfaces like printed matter or laminated material, further developments are discussed. The device has been extended for observation of photoelasticity effects and therefore homogeneity of polarization behaviour. A refined experimental set-up is introduced. Variation of plane of focus and incident angle are used for separation of various the images of the layers of the surface under test, cross and parallel polarization techniques are applied. Practical examples from current research studies are included.

  5. Focus Variation - A New Technology for High Resolution Optical 3D Surface Metrology

    NASA Astrophysics Data System (ADS)

    Scherer, S.

    2009-04-01

    Focus Variation - A New Technology for High Resolution Optical 3D Surface Metrology S. Scherer1, E. Cristea1, O. Huber1, A. Krenn1 1 ALICONA GmbH Graz, Austria The need for increasing accuracy is a characteristic of all geo-applications, and hence of the instruments contributing to obtaining relevant data. Small and fine sensors are being developed, measuring different parameters of our geosystem and requiring continuous validation and calibration. These sensors have often very small components (fine sensors able to sense dust, atmospheric water vapour characteristics, pressure change, gravimeters, satellite micro-components), showing complex topographies including steep flanks and having varying reflective properties. In order to get valid and reliable results, quality assurance of these instruments and sensors is required. The optical technology Focus-Variation, developed by Alicona and added in the latest draft of the upcoming ISO standard 25178, provides high resolution 3D surface metrology even at those complex topographies. The technique of Focus-Variation combines the small depth of focus of an optical system with vertical scanning to provide topographical and color information from the variation of focus. It is used for high-resolution optical 3D surface measurements. The traceable and repeatable measurement results are further being used for calibration and validation purposes. Some of the characteristics of the technology are: - Measurement of instruments / samples with steep flanks up to 80° - Measurement of materials with strongly varying reflection properties - Measurement of surfaces presenting fine (from 10nm) or strong roughness Here, we present the operating principle and possible applications of the optical 3D measurement system "InfiniteFocus", which is based on the technology of Focus-Variation and used for quality assurance in the lab and in production. With the vertical resolution of up to 10nm, InfiniteFocus yields meaningful form and

  6. Accuracy assessment of human trunk surface 3D reconstructions from an optical digitising system.

    PubMed

    Pazos, V; Cheriet, F; Song, L; Labelle, H; Dansereau, J

    2005-01-01

    The lack of reliable techniques to follow up scoliotic deformity from the external asymmetry of the trunk leads to a general use of X-rays and indices of spinal deformity. Young adolescents with idiopathic scoliosis need intensive follow-ups for many years and, consequently, they are repeatedly exposed to ionising radiation, which is hazardous to their long-term health. Furthermore, treatments attempt to improve both spinal and surface deformities, but internal indices do not describe the external asymmetry. The purpose of this study was to assess a commercial, optical 3D digitising system for the 3D reconstruction of the entire trunk for clinical assessment of external asymmetry. The resulting surface is a textured, high-density polygonal mesh. The accuracy assessment was based on repeated reconstructions of a manikin with markers fixed on it. The average normal distance between the reconstructed surfaces and the reference data (markers measured with CMM) was 1.1 +/- 0.9 mm. PMID:15742714

  7. Laser electro-optic system for rapid three-dimensional /3-D/ topographic mapping of surfaces

    NASA Technical Reports Server (NTRS)

    Altschuler, M. D.; Altschuler, B. R.; Taboada, J.

    1981-01-01

    It is pointed out that the generic utility of a robot in a factory/assembly environment could be substantially enhanced by providing a vision capability to the robot. A standard videocamera for robot vision provides a two-dimensional image which contains insufficient information for a detailed three-dimensional reconstruction of an object. Approaches which supply the additional information needed for the three-dimensional mapping of objects with complex surface shapes are briefly considered and a description is presented of a laser-based system which can provide three-dimensional vision to a robot. The system consists of a laser beam array generator, an optical image recorder, and software for controlling the required operations. The projection of a laser beam array onto a surface produces a dot pattern image which is viewed from one or more suitable perspectives. Attention is given to the mathematical method employed, the space coding technique, the approaches used for obtaining the transformation parameters, the optics for laser beam array generation, the hardware for beam array coding, and aspects of image acquisition.

  8. Focus Variation - A New Technology for High Resolution Optical 3D Surface Metrology in the Micro- and Nanometer Range

    NASA Astrophysics Data System (ADS)

    Huber, O.

    2009-04-01

    Focus Variation - A New Technology for High Resolution Optical 3D Surface Metrology in the Micro- and Nanometer Range S. Scherer1, E. Cristea1, O. Huber1, A. Krenn1 1 ALICONA GmbH Graz, Austria The need for increasing accuracy is a characteristic of all geo-applications, and hence of the instruments contributing to obtaining relevant data. Small and fine sensors are being developed, measuring different parameters of our geosystem and requiring continuous validation and calibration. These sensors have often very small components (fine sensors able to sense dust, atmospheric water vapour characteristics, pressure change, gravimeters, satellite micro-components), showing complex topographies including steep flanks and having varying reflective properties. In order to get valid and reliable results, quality assurance of these instruments and sensors is required. The optical technology Focus-Variation, developed by Alicona and added in the latest draft of the upcoming ISO standard 25178, provides high resolution 3D surface metrology even at those complex topographies. The technique of Focus-Variation combines the small depth of focus of an optical system with vertical scanning to provide topographical and color information from the variation of focus. It is used for high-resolution optical 3D surface measurements. The traceable and repeatable measurement results are further being used for e.g. calibration and validation purposes. Some of the characteristics of the technology are: - Measurement of instruments / samples with steep flanks up to 80° - Measurement of materials with strongly varying reflection properties - Measurement of surfaces presenting fine (from 10nm) or strong roughness Here, we present the operating principle and possible applications of the optical 3D measurement system "InfiniteFocus", which is based on the technology of Focus-Variation. With the vertical resolution of up to 10nm, InfiniteFocus yields meaningful form and roughness measurements. The

  9. High-resolution 3-D imaging of surface damage sites in fused silica with Optical Coherence Tomography

    SciTech Connect

    Guss, G; Bass, I; Hackel, R; Mailhiot, C; Demos, S G

    2007-10-30

    In this work, we present the first successful demonstration of a non-contact technique to precisely measure the 3D spatial characteristics of laser induced surface damage sites in fused silica for large aperture laser systems by employing Optical Coherence Tomography (OCT). What makes OCT particularly interesting in the characterization of optical materials for large aperture laser systems is that its axial resolution can be maintained with working distances greater than 5 cm, whether viewing through air or through the bulk of thick optics. Specifically, when mitigating surface damage sites against further growth by CO{sub 2} laser evaporation of the damage, it is important to know the depth of subsurface cracks below the damage site. These cracks are typically obscured by the damage rubble when imaged from above the surface. The results to date clearly demonstrate that OCT is a unique and valuable tool for characterizing damage sites before and after the mitigation process. We also demonstrated its utility as an in-situ diagnostic to guide and optimize our process when mitigating surface damage sites on large, high-value optics.

  10. Modular optical topometric sensor for 3D acquisition of human body surfaces and long-term monitoring of variations.

    PubMed

    Bischoff, Guido; Böröcz, Zoltan; Proll, Christian; Kleinheinz, Johannes; von Bally, Gert; Dirksen, Dieter

    2007-08-01

    Optical topometric 3D sensors such as laser scanners and fringe projection systems allow detailed digital acquisition of human body surfaces. For many medical applications, however, not only the current shape is important, but also its changes, e.g., in the course of surgical treatment. In such cases, time delays of several months between subsequent measurements frequently occur. A modular 3D coordinate measuring system based on the fringe projection technique is presented that allows 3D coordinate acquisition including calibrated color information, as well as the detection and visualization of deviations between subsequent measurements. In addition, parameters describing the symmetry of body structures are determined. The quantitative results of the analysis may be used as a basis for objective documentation of surgical therapy. The system is designed in a modular way, and thus, depending on the object of investigation, two or three cameras with different capabilities in terms of resolution and color reproduction can be utilized to optimize the set-up.

  11. FIT3D: Fitting optical spectra

    NASA Astrophysics Data System (ADS)

    Sánchez, S. F.; Pérez, E.; Sánchez-Blázquez, P.; González, J. J.; Rosales-Ortega, F. F.; Cano-Díaz, M.; López-Cobá, C.; Marino, R. A.; Gil de Paz, A.; Mollá, M.; López-Sánchez, A. R.; Ascasibar, Y.; Barrera-Ballesteros, J.

    2016-09-01

    FIT3D fits optical spectra to deblend the underlying stellar population and the ionized gas, and extract physical information from each component. FIT3D is focused on the analysis of Integral Field Spectroscopy data, but is not restricted to it, and is the basis of Pipe3D, a pipeline used in the analysis of datasets like CALIFA, MaNGA, and SAMI. It can run iteratively or in an automatic way to derive the parameters of a large set of spectra.

  12. 3D optical measuring technologies and systems

    NASA Astrophysics Data System (ADS)

    Chugui, Yuri V.

    2005-02-01

    The results of the R & D activity of TDI SIE SB RAS in the field of the 3D optical measuring technologies and systems for noncontact 3D optical dimensional inspection applied to atomic and railway industry safety problems are presented. This activity includes investigations of diffraction phenomena on some 3D objects, using the original constructive calculation method. The efficient algorithms for precise determining the transverse and longitudinal sizes of 3D objects of constant thickness by diffraction method, peculiarities on formation of the shadow and images of the typical elements of the extended objects were suggested. Ensuring the safety of nuclear reactors and running trains as well as their high exploitation reliability requires a 100% noncontact precise inspection of geometrical parameters of their components. To solve this problem we have developed methods and produced the technical vision measuring systems LMM, CONTROL, PROFIL, and technologies for noncontact 3D dimensional inspection of grid spacers and fuel elements for the nuclear reactor VVER-1000 and VVER-440, as well as automatic laser diagnostic COMPLEX for noncontact inspection of geometric parameters of running freight car wheel pairs. The performances of these systems and the results of industrial testing are presented and discussed. The created devices are in pilot operation at Atomic and Railway Companies.

  13. Pulse electrochemical machining on Invar alloy: Optical microscopic/SEM and non-contact 3D measurement study of surface analyses

    NASA Astrophysics Data System (ADS)

    Kim, S. H.; Choi, S. G.; Choi, W. K.; Yang, B. Y.; Lee, E. S.

    2014-09-01

    In this study, Invar alloy (Fe 63.5%, Ni 36.5%) was electrochemically polished by PECM (Pulse Electro Chemical Machining) in a mixture of NaCl, glycerin, and distilled water. A series of PECM experiments were carried out with different voltages and different electrode shapes, and then the surfaces of polished Invar alloy were investigated. The polished Invar alloy surfaces were investigated by optical microscope, scanning electron microscope (SEM), and non-contact 3D measurement (white light microscopes) and it was found that different applied voltages produced different surface characteristics on the Invar alloy surface because of the locally concentrated applied voltage on the Invar alloy surface. Moreover, we found that the shapes of electrode also have an effect on the surface characteristics on Invar alloy surface by influencing the applied voltage. These experimental findings provide fundamental knowledge for PECM of Invar alloy by surface analysis.

  14. Nonlaser-based 3D surface imaging

    SciTech Connect

    Lu, Shin-yee; Johnson, R.K.; Sherwood, R.J.

    1994-11-15

    3D surface imaging refers to methods that generate a 3D surface representation of objects of a scene under viewing. Laser-based 3D surface imaging systems are commonly used in manufacturing, robotics and biomedical research. Although laser-based systems provide satisfactory solutions for most applications, there are situations where non laser-based approaches are preferred. The issues that make alternative methods sometimes more attractive are: (1) real-time data capturing, (2) eye-safety, (3) portability, and (4) work distance. The focus of this presentation is on generating a 3D surface from multiple 2D projected images using CCD cameras, without a laser light source. Two methods are presented: stereo vision and depth-from-focus. Their applications are described.

  15. Optical 3D Deformation Measurement Utilizing Non-planar Surface for the Development of an “Intelligent Tire”

    NASA Astrophysics Data System (ADS)

    Matsuzaki, Ryosuke; Hiraoka, Naoki; Todoroki, Akira; Mizutani, Yoshihiro

    Intelligent tires, also known as smart tires, are equipped with sensors to monitor the strain of the interior surface and the rolling radius of tire, and are expected to improve the reliability of tires and tire control systems such as anti-lock braking systems (ABS). However, the high stiffness of an attached sensor like a strain gauge causes sensors to debond from the tire rubber. In the present study, a novel optical method is used for the concurrent monitoring of in-plane strain and out-of-plane displacement (rolling radius) utilizing the non-planar surface of the monitoring object. The optical method enables noncontact measurement of strain distribution. The in-plane strain and out-of-plane displacement are calculated by using image processing with an image of the interior surface of a tire that is taken with a single CCD camera fixed on the wheel rim. This new monitoring system is applied to an aluminum beam and a commercially available radial tire. As a result, the monitoring system provides concurrent measurement of in-plane strain, out-of-plane displacement and tire pressure, and is shown to be an effective monitoring system for intelligent tires.

  16. Automatic optical inspection system for 3D surface profile measurement of multi-microlenses using the optimal inspection path

    NASA Astrophysics Data System (ADS)

    Yang, Shih-Wei; Lin, Shir-Kuan

    2014-07-01

    In this paper, an automatic optical inspection system is proposed for measuring the three-dimensional surface profile of multi-microlenses according to the optimal inspection path. The proposed system is applicable for full and sampling inspection of microlens arrays, and has the following contributions: (1) the optimal inspection path of sampling inspection is derived by a Genetic Algorithm considering the acceleration characteristic of the XY-table. (2) The incomplete microlens fringe is removed, and the center of each microlens can be automatically positioned. (3) The phase difference of each neighboring pixel is calculated through the concept of sign reversal in order to rebuild the surface profile. According to the experimental results, the lens sag of microlenses in different sizes can be correctly measured by the proposed system, and a relative error of 3.4% (max) can be achieved. Compared with other methods, the positioning time of the proposed method is shortened by 10% to 30%, validating the practicability of this system.

  17. 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.

  18. Multi-Surface and Multi-Field Co-Segmentation of 3-D Retinal Optical Coherence Tomography

    PubMed Central

    Sonka, Milan; Kwon, Young H.; Kemp, Pavlina; Abràmoff, Michael D.; Wu, Xiaodong

    2015-01-01

    When segmenting intraretinal layers from multiple optical coherence tomography (OCT) images forming a mosaic or a set of repeated scans, it is attractive to exploit the additional information from the overlapping areas rather than discarding it as redundant, especially in low contrast and noisy images. However, it is currently not clear how to effectively combine the multiple information sources available in the areas of overlap. In this paper, we propose a novel graph-theoretic method for multi-surface multi-field co-segmentation of intraretinal layers, assuring consistent segmentation of the fields across the overlapped areas. After 2-D en-face alignment, all the fields are segmented simultaneously, imposing a priori soft interfield-intrasurface constraints for each pair of overlapping fields. The constraints penalize deviations from the expected surface height differences, taken to be the depth-axis shifts that produce the maximum cross-correlation of pairwise-overlapped areas. The method’s accuracy and reproducibility are evaluated qualitatively and quantitatively on 212 OCT images (20 nine-field, 32 single-field acquisitions) from 26 patients with glaucoma. Qualitatively, the obtained thickness maps show no stitching artifacts, compared to pronounced stitches when the fields are segmented independently. Quantitatively, two ophthalmologists manually traced four intraretinal layers on 10 patients, and the average error (4.58±1.46 μm) was comparable to the average difference between the observers (5.86±1.72 μm). Furthermore, we show the benefit of the proposed approach in co-segmenting longitudinal scans. As opposed to segmenting layers in each of the fields independently, the proposed co-segmentation method obtains consistent segmentations across the overlapped areas, producing accurate, reproducible, and artifact-free results. PMID:25020067

  19. Optical fabrication of lightweighted 3D printed mirrors

    NASA Astrophysics Data System (ADS)

    Herzog, Harrison; Segal, Jacob; Smith, Jeremy; Bates, Richard; Calis, Jacob; De La Torre, Alyssa; Kim, Dae Wook; Mici, Joni; Mireles, Jorge; Stubbs, David M.; Wicker, Ryan

    2015-09-01

    Direct Metal Laser Sintering (DMLS) and Electron Beam Melting (EBM) 3D printing technologies were utilized to create lightweight, optical grade mirrors out of AlSi10Mg aluminum and Ti6Al4V titanium alloys at the University of Arizona in Tucson. The mirror prototypes were polished to meet the λ/20 RMS and λ/4 P-V surface figure requirements. The intent of this project was to design topologically optimized mirrors that had a high specific stiffness and low surface displacement. Two models were designed using Altair Inspire software, and the mirrors had to endure the polishing process with the necessary stiffness to eliminate print-through. Mitigating porosity of the 3D printed mirror blanks was a challenge in the face of reconciling new printing technologies with traditional optical polishing methods. The prototypes underwent Hot Isostatic Press (HIP) and heat treatment to improve density, eliminate porosity, and relieve internal stresses. Metal 3D printing allows for nearly unlimited topological constraints on design and virtually eliminates the need for a machine shop when creating an optical quality mirror. This research can lead to an increase in mirror mounting support complexity in the manufacturing of lightweight mirrors and improve overall process efficiency. The project aspired to have many future applications of light weighted 3D printed mirrors, such as spaceflight. This paper covers the design/fab/polish/test of 3D printed mirrors, thermal/structural finite element analysis, and results.

  20. Surface reconstruction for 3D remote sensing

    NASA Astrophysics Data System (ADS)

    Baran, Matthew S.; Tutwiler, Richard L.; Natale, Donald J.

    2012-05-01

    This paper examines the performance of the local level set method on the surface reconstruction problem for unorganized point clouds in three dimensions. Many laser-ranging, stereo, and structured light devices produce three dimensional information in the form of unorganized point clouds. The point clouds are sampled from surfaces embedded in R3 from the viewpoint of a camera focal plane or laser receiver. The reconstruction of these objects in the form of a triangulated geometric surface is an important step in computer vision and image processing. The local level set method uses a Hamilton-Jacobi partial differential equation to describe the motion of an implicit surface in threespace. An initial surface which encloses the data is allowed to move until it becomes a smooth fit of the unorganized point data. A 3D point cloud test suite was assembled from publicly available laser-scanned object databases. The test suite exhibits nonuniform sampling rates and various noise characteristics to challenge the surface reconstruction algorithm. Quantitative metrics are introduced to capture the accuracy and efficiency of surface reconstruction on the degraded data. The results characterize the robustness of the level set method for surface reconstruction as applied to 3D remote sensing.

  1. Automatic respiration tracking for radiotherapy using optical 3D camera

    NASA Astrophysics Data System (ADS)

    Li, Tuotuo; Geng, Jason; Li, Shidong

    2013-03-01

    Rapid optical three-dimensional (O3D) imaging systems provide accurate digitized 3D surface data in real-time, with no patient contact nor radiation. The accurate 3D surface images offer crucial information in image-guided radiation therapy (IGRT) treatments for accurate patient repositioning and respiration management. However, applications of O3D imaging techniques to image-guided radiotherapy have been clinically challenged by body deformation, pathological and anatomical variations among individual patients, extremely high dimensionality of the 3D surface data, and irregular respiration motion. In existing clinical radiation therapy (RT) procedures target displacements are caused by (1) inter-fractional anatomy changes due to weight, swell, food/water intake; (2) intra-fractional variations from anatomy changes within any treatment session due to voluntary/involuntary physiologic processes (e.g. respiration, muscle relaxation); (3) patient setup misalignment in daily reposition due to user errors; and (4) changes of marker or positioning device, etc. Presently, viable solution is lacking for in-vivo tracking of target motion and anatomy changes during the beam-on time without exposing patient with additional ionized radiation or high magnet field. Current O3D-guided radiotherapy systems relay on selected points or areas in the 3D surface to track surface motion. The configuration of the marks or areas may change with time that makes it inconsistent in quantifying and interpreting the respiration patterns. To meet the challenge of performing real-time respiration tracking using O3D imaging technology in IGRT, we propose a new approach to automatic respiration motion analysis based on linear dimensionality reduction technique based on PCA (principle component analysis). Optical 3D image sequence is decomposed with principle component analysis into a limited number of independent (orthogonal) motion patterns (a low dimension eigen-space span by eigen-vectors). New

  2. Surface Plasmons in 3D Topological Insulators

    NASA Astrophysics Data System (ADS)

    Kogar, Anshul; Vig, Sean; Cho, Gil; Thaler, Alexander; Xiao, Yiran; Hughes, Taylor; Wong, Man-Hong; Chiang, Tai-Chang; MacDougall, Greg; Abbamonte, Peter

    2015-03-01

    Most studies of three-dimensional (3D) topological insulators have concentrated on their one-electron properties as exhibited by angle-resolved photoemission spectroscopy (ARPES) or by scanning tunneling microscopy (STM). Many-body interactions are often neglected in the treatment of models of topological insulators, such as in the Kane-Mele and Bernevig-Hughes-Zhang models. Using angle-resolved inelastic electron scattering from the surface, I will present data on the collective mode that owes its existence to the presence of many-body interactions, the surface plasmon (SP), in two known 3D topological insulators, Bi2Se3 and Bi0.5Sb1.5Se1 . 5 + xTe1 . 5 - x. Surprisingly, the SP was prominent even after depressing the Fermi energy into the bulk band gap. Having studied the SP as a function of doping, momentum transfer and its aging properties, I will present evidence to suggest that bulk-surface coupling is crucial in explaining many of its properties. A simple model with dynamic bulk screening will be presented showing qualitative agreement with the observations. Lastly, the relation of the observed surface plasmon to the predicted spin-plasmon mode and to the kinks seen in the electronic dispersion as measured by ARPES will be discussed. The work was supported as part of the Center for Emergent Superconductivity, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science.

  3. Diffractive optical element for creating visual 3D images.

    PubMed

    Goncharsky, Alexander; Goncharsky, Anton; Durlevich, Svyatoslav

    2016-05-01

    A method is proposed to compute and synthesize the microrelief of a diffractive optical element to produce a new visual security feature - the vertical 3D/3D switch effect. The security feature consists in the alternation of two 3D color images when the diffractive element is tilted up/down. Optical security elements that produce the new security feature are synthesized using electron-beam technology. Sample optical security elements are manufactured that produce 3D to 3D visual switch effect when illuminated by white light. Photos and video records of the vertical 3D/3D switch effect of real optical elements are presented. The optical elements developed can be replicated using standard equipment employed for manufacturing security holograms. The new optical security feature is easy to control visually, safely protected against counterfeit, and designed to protect banknotes, documents, ID cards, etc. PMID:27137530

  4. 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.

  5. Implementation of 3D Optical Scanning Technology for Automotive Applications.

    PubMed

    Kuş, Abdil

    2009-01-01

    Reverse engineering (RE) is a powerful tool for generating a CAD model from the 3D scan data of a physical part that lacks documentation or has changed from the original CAD design of the part. The process of digitizing a part and creating a CAD model from 3D scan data is less time consuming and provides greater accuracy than manually measuring the part and designing the part from scratch in CAD. 3D optical scanning technology is one of the measurement methods which have evolved over the last few years and it is used in a wide range of areas from industrial applications to art and cultural heritage. It is also used extensively in the automotive industry for applications such as part inspections, scanning of tools without CAD definition, scanning the casting for definition of the stock (i.e. the amount of material to be removed from the surface of the castings) model for CAM programs and reverse engineering. In this study two scanning experiments of automotive applications are illustrated. The first one examines the processes from scanning to re-manufacturing the damaged sheet metal cutting die, using a 3D scanning technique and the second study compares the scanned point clouds data to 3D CAD data for inspection purposes. Furthermore, the deviations of the part holes are determined by using different lenses and scanning parameters. PMID:22573995

  6. Implementation of 3D Optical Scanning Technology for Automotive Applications

    PubMed Central

    Kuş, Abdil

    2009-01-01

    Reverse engineering (RE) is a powerful tool for generating a CAD model from the 3D scan data of a physical part that lacks documentation or has changed from the original CAD design of the part. The process of digitizing a part and creating a CAD model from 3D scan data is less time consuming and provides greater accuracy than manually measuring the part and designing the part from scratch in CAD. 3D optical scanning technology is one of the measurement methods which have evolved over the last few years and it is used in a wide range of areas from industrial applications to art and cultural heritage. It is also used extensively in the automotive industry for applications such as part inspections, scanning of tools without CAD definition, scanning the casting for definition of the stock (i.e. the amount of material to be removed from the surface of the castings) model for CAM programs and reverse engineering. In this study two scanning experiments of automotive applications are illustrated. The first one examines the processes from scanning to re-manufacturing the damaged sheet metal cutting die, using a 3D scanning technique and the second study compares the scanned point clouds data to 3D CAD data for inspection purposes. Furthermore, the deviations of the part holes are determined by using different lenses and scanning parameters. PMID:22573995

  7. Implementation of 3D Optical Scanning Technology for Automotive Applications.

    PubMed

    Kuş, Abdil

    2009-01-01

    Reverse engineering (RE) is a powerful tool for generating a CAD model from the 3D scan data of a physical part that lacks documentation or has changed from the original CAD design of the part. The process of digitizing a part and creating a CAD model from 3D scan data is less time consuming and provides greater accuracy than manually measuring the part and designing the part from scratch in CAD. 3D optical scanning technology is one of the measurement methods which have evolved over the last few years and it is used in a wide range of areas from industrial applications to art and cultural heritage. It is also used extensively in the automotive industry for applications such as part inspections, scanning of tools without CAD definition, scanning the casting for definition of the stock (i.e. the amount of material to be removed from the surface of the castings) model for CAM programs and reverse engineering. In this study two scanning experiments of automotive applications are illustrated. The first one examines the processes from scanning to re-manufacturing the damaged sheet metal cutting die, using a 3D scanning technique and the second study compares the scanned point clouds data to 3D CAD data for inspection purposes. Furthermore, the deviations of the part holes are determined by using different lenses and scanning parameters.

  8. 3D geophysical inversion for contact surfaces

    NASA Astrophysics Data System (ADS)

    Lelièvre, Peter; Farquharson, Colin

    2014-05-01

    Geologists' interpretations about the Earth typically involve distinct rock units with contacts (interfaces) between them. In contrast, standard minimum-structure volumetric inversions (performed on meshes of space-filling cells) recover smooth models inconsistent with such interpretations. There are several approaches through which geophysical inversion can help recover models with the desired characteristics. Some authors have developed iterative strategies in which several volumetric inversions are performed with regularization parameters changing to achieve sharper interfaces at automatically determined locations. Another approach is to redesign the regularization to be consistent with the desired model characteristics, e.g. L1-like norms or compactness measures. A few researchers have taken approaches that limit the recovered values to lie within particular ranges, resulting in sharp discontinuities; these include binary inversion, level set methods and clustering strategies. In most of the approaches mentioned above, the model parameterization considers the physical properties in each of the many space-filling cells within the volume of interest. The exception are level set methods, in which a higher dimensional function is parameterized and the contact surface is determined from the zero-level of that function. However, even level-set methods rely on an underlying volumetric mesh. We are researching a fundamentally different type of inversion that parameterizes the Earth in terms of the contact surfaces between rock units. 3D geological Earth models typically comprise wireframe surfaces of tessellated triangles or other polygonal planar facets. This wireframe representation allows for flexible and efficient generation of complicated geological structures. Therefore, a natural approach for representing a geophysical model in an inversion is to parameterize the wireframe contact surfaces as the coordinates of the nodes (facet vertices). The geological and

  9. Rapid prototyping with optical 3D measurement systems

    NASA Astrophysics Data System (ADS)

    Gaessler, J.; Blount, G. N.; Jones, R. M.

    1994-11-01

    One of the important tools for speeding up the prototyping of an new industrial or consumer product is the rapid generation of CAD data from hand-made styling models and moulds. We present a new optical 3D digitizing system which produces in a fully automatic way non- ambiguous, absolute and complete surface coordinate data of very complex objects in a short time. The system named `OptoShape' is based on a projection of sinusoidal fringes with a true grey-level matrix projector. The system measures both non-ambiguous and absolute XYZ surface data with a pronounced robustness towards optical surface properties. By moving the 3D sensor head around the object to be digitized with a 3/5 axes manipulator, multiple range images are obtained and automatically merged into a unified cloud of point coordinates. This set of surface coordinates are transferred to a software package where interactive manipulation, sectioning and semi-automatic generation of CAD surface descriptions are performed. CNC data can also be directly generated from the point surface coordinate data set.

  10. Precision 3-D microscopy with intensity modulated fibre optic scanners

    NASA Astrophysics Data System (ADS)

    Olmos, P.

    2016-01-01

    Optical 3-D imagers constitute a family of precision and useful instruments, easily available on the market in a wide variety of configurations and performances. However, besides their cost they usually provide an image of the object (i.e. a more or less faithful representation of the reality) instead of a truly object's reconstruction. Depending on the detailed working principles of the equipment, this reconstruction may become a challenging task. Here a very simple yet reliable device is described; it is able to form images of opaque objects by illuminating them with an optical fibre and collecting the reflected light with another fibre. Its 3-D capability comes from the spatial filtering imposed by the fibres together with their movement (scanning) along the three directions: transversal (surface) and vertical. This unsophisticated approach allows one to model accurately the entire optical process and to perform the desired reconstruction, finding that information about the surface which is of interest: its profile and its reflectance, ultimately related to the type of material.

  11. Manufacturing: 3D printed micro-optics

    NASA Astrophysics Data System (ADS)

    Juodkazis, Saulius

    2016-08-01

    Uncompromised performance of micro-optical compound lenses has been achieved by high-fidelity shape definition during two-photon absorption microfabrication. The lenses have been made directly onto image sensors and even onto the tip of an optic fibre.

  12. Optical monitoring of scoliosis by 3D medical laser scanner

    NASA Astrophysics Data System (ADS)

    Rodríguez-Quiñonez, Julio C.; Sergiyenko, Oleg Yu.; Preciado, Luis C. Basaca; Tyrsa, Vera V.; Gurko, Alexander G.; Podrygalo, Mikhail A.; Lopez, Moises Rivas; Balbuena, Daniel Hernandez

    2014-03-01

    Three dimensional recording of the human body surface or anatomical areas have gained importance in many medical applications. In this paper, our 3D Medical Laser Scanner is presented. It is based on the novel principle of dynamic triangulation. We analyze the method of operation, medical applications, orthopedically diseases as Scoliosis and the most common types of skin to employ the system the most proper way. It is analyzed a group of medical problems related to the application of optical scanning in optimal way. Finally, experiments are conducted to verify the performance of the proposed system and its method uncertainty.

  13. Deconvolution in 3-D optical microscopy.

    PubMed

    Shaw, P

    1994-09-01

    Fluorescent probes are becoming ever more widely used in the study of subcellular structure, and determination of their three-dimensional distributions has become very important. Confocal microscopy is now a common technique for overcoming the problem of out-of-focus flare in fluorescence imaging, but an alternative method uses digital image processing of conventional fluorescence images--a technique often termed 'deconvolution' or 'restoration'. This review attempts to explain image deconvolution in a non-technical manner. It is also applicable to 3-D confocal images, and can provide a further significant improvement in clarity and interpretability of such images. Some examples of the application of image deconvolution to both conventional and confocal fluorescence images are shown.

  14. 3D-additive manufactured optical mount

    NASA Astrophysics Data System (ADS)

    Mammini, Paul V.; Ciscel, David; Wooten, John

    2015-09-01

    The Area Defense Anti-Munitions (ADAM) is a low cost and effective high power laser weapon system. It's designed to address and negate important threats such as short-range rockets, UAVs, and small boats. Many critical optical components operate in the system. The optics and mounts must accommodate thermal and mechanical stresses, plus maintain an exceptional wave front during operation. Lockheed Martin Space Systems Company (LMSSC) developed, designed, and currently operates ADAM. This paper covers the design and development of a key monolithic, flexured, titanium mirror mount that was manufactured by CalRAM using additive processes.

  15. 3D reconstruction of SEM images by use of optical photogrammetry software.

    PubMed

    Eulitz, Mona; Reiss, Gebhard

    2015-08-01

    Reconstruction of the three-dimensional (3D) surface of an object to be examined is widely used for structure analysis in science and many biological questions require information about their true 3D structure. For Scanning Electron Microscopy (SEM) there has been no efficient non-destructive solution for reconstruction of the surface morphology to date. The well-known method of recording stereo pair images generates a 3D stereoscope reconstruction of a section, but not of the complete sample surface. We present a simple and non-destructive method of 3D surface reconstruction from SEM samples based on the principles of optical close range photogrammetry. In optical close range photogrammetry a series of overlapping photos is used to generate a 3D model of the surface of an object. We adapted this method to the special SEM requirements. Instead of moving a detector around the object, the object itself was rotated. A series of overlapping photos was stitched and converted into a 3D model using the software commonly used for optical photogrammetry. A rabbit kidney glomerulus was used to demonstrate the workflow of this adaption. The reconstruction produced a realistic and high-resolution 3D mesh model of the glomerular surface. The study showed that SEM micrographs are suitable for 3D reconstruction by optical photogrammetry. This new approach is a simple and useful method of 3D surface reconstruction and suitable for various applications in research and teaching.

  16. 3D printed long period gratings for optical fibers.

    PubMed

    Iezzi, Victor Lambin; Boisvert, Jean-Sébastien; Loranger, Sébastien; Kashyap, Raman

    2016-04-15

    We demonstrate a simple technique for implementing long period grating (LPG) structures by the use of a 3D printer. This Letter shows a way of manipulating the mode coupling within an optical fiber by applying stress through an external 3D printed periodic structure. Different LPG lengths and periods have been studied, as well as the effect of the applied stress on the coupling efficiency from the fundamental mode to cladding modes. The technique is very simple, highly flexible, affordable, and easy to implement without the need of altering the optical fiber. This Letter is part of a growing line of interest in the use of 3D printers for optical applications.

  17. New 3D optical digitizer for orthodontic applications

    NASA Astrophysics Data System (ADS)

    Canal Bienzobas, Fernando; Dios, Federico; Garcia-Mateos, Jorge; Rivera, Alejandro

    2002-05-01

    A new three-dimensional optical digitizer working with white light and high accuracy has been developed for applications in orthodontic diagnosis, to store and analyze data taken from plaster dental casts. The scanner consists basically of a triangulation device made of a CCD camera and an active light projector using Gray code and the phase stepping method to sample the surfaces under tests. Dense clouds of 3D points of the object's surface, related to the device's reference system, are generated, from which very exact measurements can be taken. This technique allows us to greatly improve the accuracy of results that previously were obtained by using mainly manual methods. Our system has been tested successfully on many different samples.

  18. Optical characterization and measurements of autostereoscopic 3D displays

    NASA Astrophysics Data System (ADS)

    Salmimaa, Marja; Järvenpää, Toni

    2008-04-01

    3D or autostereoscopic display technologies offer attractive solutions for enriching the multimedia experience. However, both characterization and comparison of 3D displays have been challenging when the definitions for the consistent measurement methods have been lacking and displays with similar specifications may appear quite different. Earlier we have investigated how the optical properties of autostereoscopic (3D) displays can be objectively measured and what are the main characteristics defining the perceived image quality. In this paper the discussion is extended to cover the viewing freedom (VF) and the definition for the optimum viewing distance (OVD) is elaborated. VF is the volume inside which the eyes have to be to see an acceptable 3D image. Characteristics limiting the VF space are proposed to be 3D crosstalk, luminance difference and color difference. Since the 3D crosstalk can be presumed to be dominating the quality of the end user experience and in our approach is forming the basis for the calculations of the other optical parameters, the reliability of the 3D crosstalk measurements is investigated. Furthermore the effect on the derived VF definition is evaluated. We have performed comparison 3D crosstalk measurements with different measurement device apertures and the effect of different measurement geometry on the results on actual 3D displays is reported.

  19. Flexydos3D: A new deformable anthropomorphic 3D dosimeter readout with optical CT scanning

    NASA Astrophysics Data System (ADS)

    De Deene, Yves; Hill, Robin; Skyt, Peter S.; Booth, Jeremy

    2015-01-01

    A new deformable polydimethylsiloxane (PDMS) based dosimeter is proposed that can be cast in an anthropomorphic shape and that can be used for 3D radiation dosimetry of deformable targets. The new material has additional favorable characteristics as it is tissue equivalent for high-energy photons, easy to make and is non-toxic. In combination with dual wavelength optical scanning, it is a powerful dosimeter for dose verification of image gated or organ tracked radiotherapy with moving and deforming targets.

  20. 3D Surface Reconstruction and Automatic Camera Calibration

    NASA Technical Reports Server (NTRS)

    Jalobeanu, Andre

    2004-01-01

    Illustrations in this view-graph presentation are presented on a Bayesian approach to 3D surface reconstruction and camera calibration.Existing methods, surface analysis and modeling,preliminary surface reconstruction results, and potential applications are addressed.

  1. Test target for characterizing 3D resolution of optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Hu, Zhixiong; Hao, Bingtao; Liu, Wenli; Hong, Baoyu; Li, Jiao

    2014-12-01

    Optical coherence tomography (OCT) is a non-invasive 3D imaging technology which has been applied or investigated in many diagnostic fields including ophthalmology, dermatology, dentistry, cardiovasology, endoscopy, brain imaging and so on. Optical resolution is an important characteristic that can describe the quality and utility of an image acquiring system. We employ 3D printing technology to design and fabricate a test target for characterizing 3D resolution of optical coherence tomography. The test target which mimics USAF 1951 test chart was produced with photopolymer. By measuring the 3D test target, axial resolution as well as lateral resolution of a spectral domain OCT system was evaluated. For comparison, conventional microscope and surface profiler were employed to characterize the 3D test targets. The results demonstrate that the 3D resolution test targets have the potential of qualitatively and quantitatively validating the performance of OCT systems.

  2. Optical-CT imaging of complex 3D dose distributions

    NASA Astrophysics Data System (ADS)

    Oldham, Mark; Kim, Leonard; Hugo, Geoffrey

    2005-04-01

    The limitations of conventional dosimeters restrict the comprehensiveness of verification that can be performed for advanced radiation treatments presenting an immediate and substantial problem for clinics attempting to implement these techniques. In essence, the rapid advances in the technology of radiation delivery have not been paralleled by corresponding advances in the ability to verify these treatments. Optical-CT gel-dosimetry is a relatively new technique with potential to address this imbalance by providing high resolution 3D dose maps in polymer and radiochromic gel dosimeters. We have constructed a 1st generation optical-CT scanner capable of high resolution 3D dosimetry and applied it to a number of simple and increasingly complex dose distributions including intensity-modulated-radiation-therapy (IMRT). Prior to application to IMRT, the robustness of optical-CT gel dosimetry was investigated on geometry and variable attenuation phantoms. Physical techniques and image processing methods were developed to minimize deleterious effects of refraction, reflection, and scattered laser light. Here we present results of investigations into achieving accurate high-resolution 3D dosimetry with optical-CT, and show clinical examples of 3D IMRT dosimetry verification. In conclusion, optical-CT gel dosimetry can provide high resolution 3D dose maps that greatly facilitate comprehensive verification of complex 3D radiation treatments. Good agreement was observed at high dose levels (>50%) between planned and measured dose distributions. Some systematic discrepancies were observed however (rms discrepancy 3% at high dose levels) indicating further work is required to eliminate confounding factors presently compromising the accuracy of optical-CT 3D gel-dosimetry.

  3. S3D: An interactive surface grid generation tool

    NASA Technical Reports Server (NTRS)

    Luh, Raymond Ching-Chung; Pierce, Lawrence E.; Yip, David

    1992-01-01

    S3D, an interactive software tool for surface grid generation, is described. S3D provides the means with which a geometry definition based either on a discretized curve set or a rectangular set can be quickly processed towards the generation of a surface grid for computational fluid dynamics (CFD) applications. This is made possible as a result of implementing commonly encountered surface gridding tasks in an environment with a highly efficient and user friendly graphical interface. Some of the more advanced features of S3D include surface-surface intersections, optimized surface domain decomposition and recomposition, and automated propagation of edge distributions to surrounding grids.

  4. 3D printed long period gratings for optical fibers.

    PubMed

    Iezzi, Victor Lambin; Boisvert, Jean-Sébastien; Loranger, Sébastien; Kashyap, Raman

    2016-04-15

    We demonstrate a simple technique for implementing long period grating (LPG) structures by the use of a 3D printer. This Letter shows a way of manipulating the mode coupling within an optical fiber by applying stress through an external 3D printed periodic structure. Different LPG lengths and periods have been studied, as well as the effect of the applied stress on the coupling efficiency from the fundamental mode to cladding modes. The technique is very simple, highly flexible, affordable, and easy to implement without the need of altering the optical fiber. This Letter is part of a growing line of interest in the use of 3D printers for optical applications. PMID:27082365

  5. Optically Addressed Spatial Light Modulators for 3d Display

    NASA Astrophysics Data System (ADS)

    Collings, N.

    An optically addressed spatial light modulator (OASLM) records the image on a write beam and transfers it to a read beam. Some example application areas are: image transduction; optical correlation; adaptive optics; and optical neural networks. Current interest in OASLMs has been generated by the work of Qinetiq on 3D display. This work is based on Active tiling, where an image can be recorded in one part of the device and is memorised, whilst the remainder of the device is updated with images. This paper will explain this system and survey the technological alternatives for this application.

  6. 3D SEM for surface topography quantification - a case study on dental surfaces

    NASA Astrophysics Data System (ADS)

    Glon, F.; Flys, O.; Lööf, P.-J.; Rosén, B.-G.

    2014-03-01

    3D analysis of surface topography is becoming a more used tool for industry and research. New ISO standards are being launched to assist in quantifying engineering surfaces. The traditional optical measuring instrumentation used for 3D surface characterization has been optical interferometers and confocal based instrumentation. However, the resolution here is limited in the lateral dimension to the wavelength of visible light to about 500 nm. The great advantage using the SEM for topography measurements is the high flexibility to zoom from low magnifications and locating interesting areas to high magnification of down to nanometer large surface features within seconds. This paper presents surface characterization of dental implant micro topography. 3D topography data was created from SEM images using commercial photogrammetric software. A coherence scanning interferometer was used for reference measurements to compare with the 3D SEM measurements on relocated areas. As a result of this study, measurements emphasizes that the correlation between the accepted CSI measurements and the new technology represented by photogrammetry based on SEM images for many areal characterization parameters are around or less than 20%. The importance of selecting sampling and parameter sensitivity to varying sampling is high-lighted. Future work includes a broader study of limitations of the photogrammetry technique on certified micro-geometries and more application surfaces at different scales.

  7. Optical 3D-coordinate measuring system using structured light

    NASA Astrophysics Data System (ADS)

    Schreiber, Wolfgang; Notni, Gunther; Kuehmstedt, Peter; Gerber, Joerg; Kowarschik, Richard M.

    1996-09-01

    The paper is aimed at the description of an optical shape measuring technique based on a consistent principle using fringe projection technique. We demonstrate a real 3D- coordinate measuring system where the sale of coordinates is given only by the illumination-structures. This method has the advantages that the aberration of the observing system and the depth-dependent imaging scale have no influence on the measuring accuracy and, moreover, the measurements are independent of the position of the camera with respect to the object under test. Furthermore, it is shown that the influence of specular effects of the surface on the measuring result can be eliminated. Moreover, we developed a very simple algorithm to calibrate the measuring system. The measuring examples show that a measuring accuracy of 10-4 (i.e. 10 micrometers ) within an object volume of 100 X 100 X 70 mm3 is achievable. Furthermore, it is demonstrated that the set of coordinate values can be processed in CNC- and CAD-systems.

  8. Tactile-optical 3D sensor applying image processing

    NASA Astrophysics Data System (ADS)

    Neuschaefer-Rube, Ulrich; Wissmann, Mark

    2009-01-01

    The tactile-optical probe (so-called fiber probe) is a well-known probe in micro-coordinate metrology. It consists of an optical fiber with a probing element at its end. This probing element is adjusted in the imaging plane of the optical system of an optical coordinate measuring machine (CMM). It can be illuminated through the fiber by a LED. The position of the probe is directly detected by image processing algorithms available in every modern optical CMM and not by deflections at the fixation of the probing shaft. Therefore, the probing shaft can be very thin and flexible. This facilitates the measurement with very small probing forces and the realization of very small probing elements (diameter: down to 10 μm). A limitation of this method is that at present the probe does not have full 3D measurement capability. At the Physikalisch-Technische Bundesanstalt (PTB), several arrangements and measurement principles for a full 3D tactile-optical probe have been implemented and tested successfully in cooperation with Werth-Messtechnik, Giessen, Germany. This contribution provides an overview of the results of these activities.

  9. Optical Sensors and Methods for Underwater 3D Reconstruction

    PubMed Central

    Massot-Campos, Miquel; Oliver-Codina, Gabriel

    2015-01-01

    This paper presents a survey on optical sensors and methods for 3D reconstruction in underwater environments. The techniques to obtain range data have been listed and explained, together with the different sensor hardware that makes them possible. The literature has been reviewed, and a classification has been proposed for the existing solutions. New developments, commercial solutions and previous reviews in this topic have also been gathered and considered. PMID:26694389

  10. 3D face recognition based on matching of facial surfaces

    NASA Astrophysics Data System (ADS)

    Echeagaray-Patrón, Beatriz A.; Kober, Vitaly

    2015-09-01

    Face recognition is an important task in pattern recognition and computer vision. In this work a method for 3D face recognition in the presence of facial expression and poses variations is proposed. The method uses 3D shape data without color or texture information. A new matching algorithm based on conformal mapping of original facial surfaces onto a Riemannian manifold followed by comparison of conformal and isometric invariants computed in the manifold is suggested. Experimental results are presented using common 3D face databases that contain significant amount of expression and pose variations.

  11. Open-source 3D-printable optics equipment.

    PubMed

    Zhang, Chenlong; Anzalone, Nicholas C; Faria, Rodrigo P; Pearce, Joshua M

    2013-01-01

    Just as the power of the open-source design paradigm has driven down the cost of software to the point that it is accessible to most people, the rise of open-source hardware is poised to drive down the cost of doing experimental science to expand access to everyone. To assist in this aim, this paper introduces a library of open-source 3-D-printable optics components. This library operates as a flexible, low-cost public-domain tool set for developing both research and teaching optics hardware. First, the use of parametric open-source designs using an open-source computer aided design package is described to customize the optics hardware for any application. Second, details are provided on the use of open-source 3-D printers (additive layer manufacturing) to fabricate the primary mechanical components, which are then combined to construct complex optics-related devices. Third, the use of the open-source electronics prototyping platform are illustrated as control for optical experimental apparatuses. This study demonstrates an open-source optical library, which significantly reduces the costs associated with much optical equipment, while also enabling relatively easily adapted customizable designs. The cost reductions in general are over 97%, with some components representing only 1% of the current commercial investment for optical products of similar function. The results of this study make its clear that this method of scientific hardware development enables a much broader audience to participate in optical experimentation both as research and teaching platforms than previous proprietary methods.

  12. Open-Source 3D-Printable Optics Equipment

    PubMed Central

    Zhang, Chenlong; Anzalone, Nicholas C.; Faria, Rodrigo P.; Pearce, Joshua M.

    2013-01-01

    Just as the power of the open-source design paradigm has driven down the cost of software to the point that it is accessible to most people, the rise of open-source hardware is poised to drive down the cost of doing experimental science to expand access to everyone. To assist in this aim, this paper introduces a library of open-source 3-D-printable optics components. This library operates as a flexible, low-cost public-domain tool set for developing both research and teaching optics hardware. First, the use of parametric open-source designs using an open-source computer aided design package is described to customize the optics hardware for any application. Second, details are provided on the use of open-source 3-D printers (additive layer manufacturing) to fabricate the primary mechanical components, which are then combined to construct complex optics-related devices. Third, the use of the open-source electronics prototyping platform are illustrated as control for optical experimental apparatuses. This study demonstrates an open-source optical library, which significantly reduces the costs associated with much optical equipment, while also enabling relatively easily adapted customizable designs. The cost reductions in general are over 97%, with some components representing only 1% of the current commercial investment for optical products of similar function. The results of this study make its clear that this method of scientific hardware development enables a much broader audience to participate in optical experimentation both as research and teaching platforms than previous proprietary methods. PMID:23544104

  13. Open-source 3D-printable optics equipment.

    PubMed

    Zhang, Chenlong; Anzalone, Nicholas C; Faria, Rodrigo P; Pearce, Joshua M

    2013-01-01

    Just as the power of the open-source design paradigm has driven down the cost of software to the point that it is accessible to most people, the rise of open-source hardware is poised to drive down the cost of doing experimental science to expand access to everyone. To assist in this aim, this paper introduces a library of open-source 3-D-printable optics components. This library operates as a flexible, low-cost public-domain tool set for developing both research and teaching optics hardware. First, the use of parametric open-source designs using an open-source computer aided design package is described to customize the optics hardware for any application. Second, details are provided on the use of open-source 3-D printers (additive layer manufacturing) to fabricate the primary mechanical components, which are then combined to construct complex optics-related devices. Third, the use of the open-source electronics prototyping platform are illustrated as control for optical experimental apparatuses. This study demonstrates an open-source optical library, which significantly reduces the costs associated with much optical equipment, while also enabling relatively easily adapted customizable designs. The cost reductions in general are over 97%, with some components representing only 1% of the current commercial investment for optical products of similar function. The results of this study make its clear that this method of scientific hardware development enables a much broader audience to participate in optical experimentation both as research and teaching platforms than previous proprietary methods. PMID:23544104

  14. Large optical 3D MEMS switches in access networks

    NASA Astrophysics Data System (ADS)

    Madamopoulos, Nicholas; Kaman, Volkan; Yuan, Shifu; Jerphagnon, Olivier; Helkey, Roger; Bowers, John E.

    2007-09-01

    Interest is high among residential customers and businesses for advanced, broadband services such as fast Internet access, electronic commerce, video-on-demand, digital broadcasting, teleconferencing and telemedicine. In order to satisfy such growing demand of end-customers, access technologies such as fiber-to-the-home/building (FTTH/B) are increasingly being deployed. Carriers can reduce maintenance costs, minimize technology obsolescence and introduce new services easily by reducing active elements in the fiber access network. However, having a passive optical network (PON) also introduces operational and maintenance challenges. Increased diagnostic monitoring capability of the network becomes a necessity as more and more fibers are provisioned to deliver services to the end-customers. This paper demonstrates the clear advantages that large 3D optical MEMS switches offer in solving these access network problems. The advantages in preventative maintenance, remote monitoring, test and diagnostic capability are highlighted. The low optical insertion loss for all switch optical connections of the switch enables the monitoring, grooming and serving of a large number of PON lines and customers. Furthermore, the 3D MEMS switch is transparent to optical wavelengths and data formats, thus making it easy to incorporate future upgrades, such higher bit rates or DWDM overlay to a PON.

  15. Quantum Degenerate Strontium in a 3D Optical Lattice

    NASA Astrophysics Data System (ADS)

    Aman, J. A.; Desalvo, B. J.; Killian, T. C.

    2014-05-01

    We present our experiments with quantum degenerate neutral strontium in a 3-D optical lattice formed with 532 nm light. Precision control and manipulation of quantum degenerate gases in optical lattices allows for the realization and investigation of tunable many-body systems. Strontium, in particular, has been studied extensively in optical lattices due to the narrow 5s21S0 --> 5 s 5 p3Pj transitions for use as an atomic clock. However, in the present work, we take advantage of these narrow transitions together with strontium's unique isotopic properties to investigate interaction regimes inaccessible to alkali atoms. Among the topics we plan to explore are formation of ultracold molecules using an optical Feshbach resonance as well as the effects of dissipation on atom dynamics. This work was supported by Rice University, Shell, the Welch Foundation (C-1579) and the National Science Foundation (PHY-1205946).

  16. Quantifying the surface chemistry of 3D matrices in situ

    NASA Astrophysics Data System (ADS)

    Tzeranis, Dimitrios S.; So, Peter T. C.; Yannas, Ioannis V.

    2014-03-01

    Despite the major role of the matrix (the insoluble environment around cells) in physiology and pathology, there are very few and limited methods that can quantify the surface chemistry of a 3D matrix such as a biomaterial or tissue ECM. This study describes a novel optical-based methodology that can quantify the surface chemistry (density of adhesion ligands for particular cell adhesion receptors) of a matrix in situ. The methodology utilizes fluorescent analogs (markers) of the receptor of interest and a series of binding assays, where the amount of bound markers on the matrix is quantified via spectral multi-photon imaging. The study provides preliminary results for the quantification of the ligands for the two major collagen-binding integrins (α1β1, α2β1) in porous collagen scaffolds that have been shown to be able to induce maximum regeneration in transected peripheral nerves. The developed methodology opens the way for quantitative descriptions of the insoluble microenvironment of cells in physiology and pathology, and for integrating the matrix in quantitative models of cell signaling. α

  17. Constructing 3D microtubule networks using holographic optical trapping

    PubMed Central

    Bergman, J.; Osunbayo, O.; Vershinin, M.

    2015-01-01

    Developing abilities to assemble nanoscale structures is a major scientific and engineering challenge. We report a technique which allows precise positioning and manipulation of individual rigid filaments, enabling construction of custom-designed 3D filament networks. This approach uses holographic optical trapping (HOT) for nano-positioning and microtubules (MTs) as network building blocks. MTs are desirable engineering components due to their high aspect ratio, rigidity, and their ability to serve as substrate for directed nano-transport, reflecting their roles in the eukaryotic cytoskeleton. The 3D architecture of MT cytoskeleton is a significant component of its function, however experimental tools to study the roles of this geometric complexity in a controlled environment have been lacking. We demonstrate the broad capabilities of our system by building a self-supporting 3D MT-based nanostructure and by conducting a MT-based transport experiment on a dynamically adjustable 3D MT intersection. Our methodology not only will advance studies of cytoskeletal networks (and associated processes such as MT-based transport) but will also likely find use in engineering nanostructures and devices. PMID:26657337

  18. Studies of the 3D surface roughness height

    NASA Astrophysics Data System (ADS)

    Avisane, Anita; Rudzitis, Janis; Kumermanis, Maris

    2013-12-01

    Nowadays nano-coatings occupy more and more significant place in technology. Innovative, functional coatings acquire new aspects from the point of view of modern technologies, considering the aggregate of physical properties that can be achieved manipulating in the production process with the properties of coatings' surfaces on micro- and nano-level. Nano-coatings are applied on machine parts, friction surfaces, contacting parts, corrosion surfaces, transparent conducting films (TCF), etc. The equipment available at present for the production of transparent conducting oxide (TCO) coatings with highest quality is based on expensive indium tin oxide (ITO) material; therefore cheaper alternatives are being searched for. One such offered alternative is zink oxide (ZnO) nano-coatings. Evaluating the TCF physical and mechanical properties and in view of the new ISO standard (EN ISO 25178) on the introduction of surface texture (3D surface roughness) in the engineering calculations, it is necessary to examine the height of 3D surface roughness, which is one of the most significant roughness parameters. The given paper studies the average values of 3D surface roughness height and the most often applied distribution laws are as follows: the normal distribution and Rayleigh distribution. The 3D surface is simulated by a normal random field.

  19. Studies of the 3D surface roughness height

    SciTech Connect

    Avisane, Anita; Rudzitis, Janis; Kumermanis, Maris

    2013-12-16

    Nowadays nano-coatings occupy more and more significant place in technology. Innovative, functional coatings acquire new aspects from the point of view of modern technologies, considering the aggregate of physical properties that can be achieved manipulating in the production process with the properties of coatings’ surfaces on micro- and nano-level. Nano-coatings are applied on machine parts, friction surfaces, contacting parts, corrosion surfaces, transparent conducting films (TCF), etc. The equipment available at present for the production of transparent conducting oxide (TCO) coatings with highest quality is based on expensive indium tin oxide (ITO) material; therefore cheaper alternatives are being searched for. One such offered alternative is zink oxide (ZnO) nano-coatings. Evaluating the TCF physical and mechanical properties and in view of the new ISO standard (EN ISO 25178) on the introduction of surface texture (3D surface roughness) in the engineering calculations, it is necessary to examine the height of 3D surface roughness, which is one of the most significant roughness parameters. The given paper studies the average values of 3D surface roughness height and the most often applied distribution laws are as follows: the normal distribution and Rayleigh distribution. The 3D surface is simulated by a normal random field.

  20. Multimodal 3D cancer-mimicking optical phantom

    PubMed Central

    Smith, Gennifer T.; Lurie, Kristen L.; Zlatev, Dimitar V.; Liao, Joseph C.; Ellerbee Bowden, Audrey K.

    2016-01-01

    Three-dimensional (3D) organ-mimicking phantoms provide realistic imaging environments for testing various aspects of optical systems, including for evaluating new probe designs, characterizing the diagnostic potential of new technologies, and assessing novel image processing algorithms prior to validation in real tissue. We introduce and characterize the use of a new material, Dragon Skin (Smooth-On Inc.), and fabrication technique, air-brushing, for fabrication of a 3D phantom that mimics the appearance of a real organ under multiple imaging modalities. We demonstrate the utility of the material and technique by fabricating the first 3D, hollow bladder phantom with realistic normal and multi-stage pathology features suitable for endoscopic detection using the gold standard imaging technique, white light cystoscopy (WLC), as well as the complementary imaging modalities of optical coherence tomography and blue light cystoscopy, which are aimed at improving the sensitivity and specificity of WLC to bladder cancer detection. The flexibility of the material and technique used for phantom construction allowed for the representation of a wide range of diseased tissue states, ranging from inflammation (benign) to high-grade cancerous lesions. Such phantoms can serve as important tools for trainee education and evaluation of new endoscopic instrumentation. PMID:26977369

  1. Optic flow aided navigation and 3D scene reconstruction

    NASA Astrophysics Data System (ADS)

    Rollason, Malcolm

    2013-10-01

    An important enabler for low cost airborne systems is the ability to exploit low cost inertial instruments. An Inertial Navigation System (INS) can provide a navigation solution, when GPS is denied, by integrating measurements from inertial sensors. However, the gyrometer and accelerometer biases of low cost inertial sensors cause compound errors in the integrated navigation solution. This paper describes experiments to establish whether (and to what extent) the navigation solution can be aided by fusing measurements from an on-board video camera with measurements from the inertial sensors. The primary aim of the work was to establish whether optic flow aided navigation is beneficial even when the 3D structure within the observed scene is unknown. A further aim was to investigate whether an INS can help to infer 3D scene content from video. Experiments with both real and synthetic data have been conducted. Real data was collected using an AR Parrot quadrotor. Empirical results illustrate that optic flow provides a useful aid to navigation even when the 3D structure of the observed scene is not known. With optic flow aiding of the INS, the computed trajectory is consistent with the true camera motion, whereas the unaided INS yields a rapidly increasing position error (the data represents ~40 seconds, after which the unaided INS is ~50 metres in error and has passed through the ground). The results of the Monte Carlo simulation concur with the empirical result. Position errors, which grow as a quadratic function of time when unaided, are substantially checked by the availability of optic flow measurements.

  2. Beam Optics Analysis - An Advanced 3D Trajectory Code

    SciTech Connect

    Ives, R. Lawrence; Bui, Thuc; Vogler, William; Neilson, Jeff; Read, Mike; Shephard, Mark; Bauer, Andrew; Datta, Dibyendu; Beal, Mark

    2006-01-03

    Calabazas Creek Research, Inc. has completed initial development of an advanced, 3D program for modeling electron trajectories in electromagnetic fields. The code is being used to design complex guns and collectors. Beam Optics Analysis (BOA) is a fully relativistic, charged particle code using adaptive, finite element meshing. Geometrical input is imported from CAD programs generating ACIS-formatted files. Parametric data is inputted using an intuitive, graphical user interface (GUI), which also provides control of convergence, accuracy, and post processing. The program includes a magnetic field solver, and magnetic information can be imported from Maxwell 2D/3D and other programs. The program supports thermionic emission and injected beams. Secondary electron emission is also supported, including multiple generations. Work on field emission is in progress as well as implementation of computer optimization of both the geometry and operating parameters. The principle features of the program and its capabilities are presented.

  3. Beam Optics Analysis — An Advanced 3D Trajectory Code

    NASA Astrophysics Data System (ADS)

    Ives, R. Lawrence; Bui, Thuc; Vogler, William; Neilson, Jeff; Read, Mike; Shephard, Mark; Bauer, Andrew; Datta, Dibyendu; Beal, Mark

    2006-01-01

    Calabazas Creek Research, Inc. has completed initial development of an advanced, 3D program for modeling electron trajectories in electromagnetic fields. The code is being used to design complex guns and collectors. Beam Optics Analysis (BOA) is a fully relativistic, charged particle code using adaptive, finite element meshing. Geometrical input is imported from CAD programs generating ACIS-formatted files. Parametric data is inputted using an intuitive, graphical user interface (GUI), which also provides control of convergence, accuracy, and post processing. The program includes a magnetic field solver, and magnetic information can be imported from Maxwell 2D/3D and other programs. The program supports thermionic emission and injected beams. Secondary electron emission is also supported, including multiple generations. Work on field emission is in progress as well as implementation of computer optimization of both the geometry and operating parameters. The principle features of the program and its capabilities are presented.

  4. Single 3D cell segmentation from optical CT microscope images

    NASA Astrophysics Data System (ADS)

    Xie, Yiting; Reeves, Anthony P.

    2014-03-01

    The automated segmentation of the nucleus and cytoplasm regions in 3D optical CT microscope images has been achieved with two methods, a global threshold gradient based approach and a graph-cut approach. For the first method, the first two peaks of a gradient figure of merit curve are selected as the thresholds for cytoplasm and nucleus segmentation. The second method applies a graph-cut segmentation twice: the first identifies the nucleus region and the second identifies the cytoplasm region. Image segmentation of single cells is important for automated disease diagnostic systems. The segmentation methods were evaluated with 200 3D images consisting of 40 samples of 5 different cell types. The cell types consisted of columnar, macrophage, metaplastic and squamous human cells and cultured A549 cancer cells. The segmented cells were compared with both 2D and 3D reference images and the quality of segmentation was determined by the Dice Similarity Coefficient (DSC). In general, the graph-cut method had a superior performance to the gradient-based method. The graph-cut method achieved an average DSC of 86% and 72% for nucleus and cytoplasm segmentations respectively for the 2D reference images and 83% and 75% for the 3D reference images. The gradient method achieved an average DSC of 72% and 51% for nucleus and cytoplasm segmentation for the 2D reference images and 71% and 51% for the 3D reference images. The DSC of cytoplasm segmentation was significantly lower than for the nucleus since the cytoplasm was not differentiated as well by image intensity from the background.

  5. Calibration of optical 3D-measuring instruments

    NASA Astrophysics Data System (ADS)

    Brand, Uwe

    1998-09-01

    For the inspection and measurement of microstructures small accurate three-dimensional coordinate measuring machines are needed. Typical measurement volumes are 10 mm by 10 mm by 3 mm and the desired 3D-measurement uncertainty is 0.1 micrometer. Up to now only optical coordinate measuring machines (CMM) offer the necessary lateral measurement ranges. But optical CMMs are restricted to two-dimensional measurements and moreover the aimed uncertainty has not been achieved yet. Since a few years new optical techniques are available which are able to measure nearly three-dimensionally (scanning white light, fringe projection, confocal microscopy, photogrammetry). In order to use these instruments and to specify their measurement uncertainty, calibration of these instruments is necessary. The calibration of the three measurement axes is divided into calibration of the lateral axes and calibration of the vertical axis. The contribution focuses on the development of new depth setting standards (1 micrometer - 1 milimeter) and their traceability.

  6. Optimized 3D watermarking for minimal surface distortion.

    PubMed

    Bors, Adrian G; Luo, Ming

    2013-05-01

    This paper proposes a new approach to 3D watermarking by ensuring the optimal preservation of mesh surfaces. A new 3D surface preservation function metric is defined consisting of the distance of a vertex displaced by watermarking to the original surface, to the watermarked object surface as well as the actual vertex displacement. The proposed method is statistical, blind, and robust. Minimal surface distortion according to the proposed function metric is enforced during the statistical watermark embedding stage using Levenberg-Marquardt optimization method. A study of the watermark code crypto-security is provided for the proposed methodology. According to the experimental results, the proposed methodology has high robustness against the common mesh attacks while preserving the original object surface during watermarking.

  7. Innovations in 3D printing: a 3D overview from optics to organs.

    PubMed

    Schubert, Carl; van Langeveld, Mark C; Donoso, Larry A

    2014-02-01

    3D printing is a method of manufacturing in which materials, such as plastic or metal, are deposited onto one another in layers to produce a three dimensional object, such as a pair of eye glasses or other 3D objects. This process contrasts with traditional ink-based printers which produce a two dimensional object (ink on paper). To date, 3D printing has primarily been used in engineering to create engineering prototypes. However, recent advances in printing materials have now enabled 3D printers to make objects that are comparable with traditionally manufactured items. In contrast with conventional printers, 3D printing has the potential to enable mass customisation of goods on a large scale and has relevance in medicine including ophthalmology. 3D printing has already been proved viable in several medical applications including the manufacture of eyeglasses, custom prosthetic devices and dental implants. In this review, we discuss the potential for 3D printing to revolutionise manufacturing in the same way as the printing press revolutionised conventional printing. The applications and limitations of 3D printing are discussed; the production process is demonstrated by producing a set of eyeglass frames from 3D blueprints. PMID:24288392

  8. Innovations in 3D printing: a 3D overview from optics to organs.

    PubMed

    Schubert, Carl; van Langeveld, Mark C; Donoso, Larry A

    2014-02-01

    3D printing is a method of manufacturing in which materials, such as plastic or metal, are deposited onto one another in layers to produce a three dimensional object, such as a pair of eye glasses or other 3D objects. This process contrasts with traditional ink-based printers which produce a two dimensional object (ink on paper). To date, 3D printing has primarily been used in engineering to create engineering prototypes. However, recent advances in printing materials have now enabled 3D printers to make objects that are comparable with traditionally manufactured items. In contrast with conventional printers, 3D printing has the potential to enable mass customisation of goods on a large scale and has relevance in medicine including ophthalmology. 3D printing has already been proved viable in several medical applications including the manufacture of eyeglasses, custom prosthetic devices and dental implants. In this review, we discuss the potential for 3D printing to revolutionise manufacturing in the same way as the printing press revolutionised conventional printing. The applications and limitations of 3D printing are discussed; the production process is demonstrated by producing a set of eyeglass frames from 3D blueprints.

  9. A 3D surface imaging system for assessing human obesity

    NASA Astrophysics Data System (ADS)

    Xu, B.; Yu, W.; Yao, M.; Yao, X.; Li, Q.; Pepper, M. R.; Freeland-Graves, J. H.

    2009-08-01

    The increasing prevalence of obesity suggests a need to develop a convenient, reliable and economical tool for assessment of this condition. Three-dimensional (3D) body surface imaging has emerged as an exciting technology for estimation of body composition. This paper presents a new 3D body imaging system, which was designed for enhanced portability, affordability, and functionality. In this system, stereo vision technology was used to satisfy the requirements for a simple hardware setup and fast image acquisitions. The portability of the system was created via a two-stand configuration, and the accuracy of body volume measurements was improved by customizing stereo matching and surface reconstruction algorithms that target specific problems in 3D body imaging. Body measurement functions dedicated to body composition assessment also were developed. The overall performance of the system was evaluated in human subjects by comparison to other conventional anthropometric methods, as well as air displacement plethysmography, for body fat assessment.

  10. 3DSEM++: Adaptive and intelligent 3D SEM surface reconstruction.

    PubMed

    Tafti, Ahmad P; Holz, Jessica D; Baghaie, Ahmadreza; Owen, Heather A; He, Max M; Yu, Zeyun

    2016-08-01

    Structural analysis of microscopic objects is a longstanding topic in several scientific disciplines, such as biological, mechanical, and materials sciences. The scanning electron microscope (SEM), as a promising imaging equipment has been around for decades to determine the surface properties (e.g., compositions or geometries) of specimens by achieving increased magnification, contrast, and resolution greater than one nanometer. Whereas SEM micrographs still remain two-dimensional (2D), many research and educational questions truly require knowledge and facts about their three-dimensional (3D) structures. 3D surface reconstruction from SEM images leads to remarkable understanding of microscopic surfaces, allowing informative and qualitative visualization of the samples being investigated. In this contribution, we integrate several computational technologies including machine learning, contrario methodology, and epipolar geometry to design and develop a novel and efficient method called 3DSEM++ for multi-view 3D SEM surface reconstruction in an adaptive and intelligent fashion. The experiments which have been performed on real and synthetic data assert the approach is able to reach a significant precision to both SEM extrinsic calibration and its 3D surface modeling. PMID:27200484

  11. Overview of 3D surface digitization technologies in Europe

    NASA Astrophysics Data System (ADS)

    D'Apuzzo, Nicola

    2006-02-01

    This paper presents an overview of the different 3D surface digitization technologies commercially available in the European market. The solutions for 3D surface measurement offered by major European companies can be divided into different groups depending on various characteristics, such as technology (e.g. laser scanning, white light projection), system construction (e.g. fix, on CMM/robot/arm) or measurement type (e.g. surface scanning, profile scanning). Crossing between the categories is possible, however, the majority of commercial products can be divided into the following groups: (a) laser profilers mounted on CMM, (b) portable coded light projection systems, (c) desktop solutions with laser profiler or coded light projectin system and multi-axes platform, (d) laser point measurement systems where both sensor and object move, (e) hand operated laser profilers, hand held laser profiler or point measurement systems, (f) dedicated systems. This paper presents the different 3D surface digitization technologies and describes them with their advantages and disadvantages. Various examples of their use are shown for different application fields. A special interest is given to applications regarding the 3D surface measurement of the human body.

  12. Recent advances in 3D SEM surface reconstruction.

    PubMed

    Tafti, Ahmad P; Kirkpatrick, Andrew B; Alavi, Zahrasadat; Owen, Heather A; Yu, Zeyun

    2015-11-01

    The scanning electron microscope (SEM), as one of the most commonly used instruments in biology and material sciences, employs electrons instead of light to determine the surface properties of specimens. However, the SEM micrographs still remain 2D images. To effectively measure and visualize the surface attributes, we need to restore the 3D shape model from the SEM images. 3D surface reconstruction is a longstanding topic in microscopy vision as it offers quantitative and visual information for a variety of applications consisting medicine, pharmacology, chemistry, and mechanics. In this paper, we attempt to explain the expanding body of the work in this area, including a discussion of recent techniques and algorithms. With the present work, we also enhance the reliability, accuracy, and speed of 3D SEM surface reconstruction by designing and developing an optimized multi-view framework. We then consider several real-world experiments as well as synthetic data to examine the qualitative and quantitative attributes of our proposed framework. Furthermore, we present a taxonomy of 3D SEM surface reconstruction approaches and address several challenging issues as part of our future work.

  13. 3DSEM++: Adaptive and intelligent 3D SEM surface reconstruction.

    PubMed

    Tafti, Ahmad P; Holz, Jessica D; Baghaie, Ahmadreza; Owen, Heather A; He, Max M; Yu, Zeyun

    2016-08-01

    Structural analysis of microscopic objects is a longstanding topic in several scientific disciplines, such as biological, mechanical, and materials sciences. The scanning electron microscope (SEM), as a promising imaging equipment has been around for decades to determine the surface properties (e.g., compositions or geometries) of specimens by achieving increased magnification, contrast, and resolution greater than one nanometer. Whereas SEM micrographs still remain two-dimensional (2D), many research and educational questions truly require knowledge and facts about their three-dimensional (3D) structures. 3D surface reconstruction from SEM images leads to remarkable understanding of microscopic surfaces, allowing informative and qualitative visualization of the samples being investigated. In this contribution, we integrate several computational technologies including machine learning, contrario methodology, and epipolar geometry to design and develop a novel and efficient method called 3DSEM++ for multi-view 3D SEM surface reconstruction in an adaptive and intelligent fashion. The experiments which have been performed on real and synthetic data assert the approach is able to reach a significant precision to both SEM extrinsic calibration and its 3D surface modeling.

  14. Towards 3-D laser nano patterning in polymer optical materials

    NASA Astrophysics Data System (ADS)

    Scully, Patricia J.; Perrie, Walter

    2015-03-01

    Progress towards 3-D subsurface structuring of polymers using femtosecond lasers is presented. Highly localised refractive index changes can be generated deep in transparent optical polymers without pre doping for photosensitisation or post processing by annealing. Understanding the writing conditions surpasses the limitations of materials, dimensions and chemistry, to facilitate unique structures entirely formed by laser-polymeric interactions to overcome materials, dimensional, refractive index and wavelength constraints.. Numerical aperture, fluence, temporal pulselength, wavelength and incident polarisation are important parameters to be considered, in achieving the desired inscription. Non-linear aspects of multiphoton absorption, plasma generation, filamentation and effects of incident polarisation on the writing conditions will be presented.

  15. Performance assessment of 3D surface imaging technique for medical imaging applications

    NASA Astrophysics Data System (ADS)

    Li, Tuotuo; Geng, Jason; Li, Shidong

    2013-03-01

    Recent development in optical 3D surface imaging technologies provide better ways to digitalize the 3D surface and its motion in real-time. The non-invasive 3D surface imaging approach has great potential for many medical imaging applications, such as motion monitoring of radiotherapy, pre/post evaluation of plastic surgery and dermatology, to name a few. Various commercial 3D surface imaging systems have appeared on the market with different dimension, speed and accuracy. For clinical applications, the accuracy, reproducibility and robustness across the widely heterogeneous skin color, tone, texture, shape properties, and ambient lighting is very crucial. Till now, a systematic approach for evaluating the performance of different 3D surface imaging systems still yet exist. In this paper, we present a systematic performance assessment approach to 3D surface imaging system assessment for medical applications. We use this assessment approach to exam a new real-time surface imaging system we developed, dubbed "Neo3D Camera", for image-guided radiotherapy (IGRT). The assessments include accuracy, field of view, coverage, repeatability, speed and sensitivity to environment, texture and color.

  16. 3D reconstruction of concave surfaces using polarisation imaging

    NASA Astrophysics Data System (ADS)

    Sohaib, A.; Farooq, A. R.; Ahmed, J.; Smith, L. N.; Smith, M. L.

    2015-06-01

    This paper presents a novel algorithm for improved shape recovery using polarisation-based photometric stereo. The majority of previous research using photometric stereo involves 3D reconstruction using both the diffuse and specular components of light; however, this paper suggests the use of the specular component only as it is the only form of light that comes directly off the surface without subsurface scattering or interreflections. Experiments were carried out on both real and synthetic surfaces. Real images were obtained using a polarisation-based photometric stereo device while synthetic images were generated using PovRay® software. The results clearly demonstrate that the proposed method can extract three-dimensional (3D) surface information effectively even for concave surfaces with complex texture and surface reflectance.

  17. 3D phase stepping optical profilometry using a fiber optic Lloyd's mirror

    NASA Astrophysics Data System (ADS)

    Kosoglu, Gulsen; Yuksel, Heba; Inci, M. Naci

    2016-04-01

    This study defines measurements of three-dimensional rigid-body shapes by using a fiber optic Lloyd's mirror. A fiber optic Lloyd's mirror assembly is basically a technique to create an optical interference pattern using the real light point sources and their images. The generated fringe pattern thanks to this technique is deformed when it is projected on an object's surface. The introduced surface profilometry algorithm depends on a multi-step phase shifting process. The deformed fringe patterns containing information of the object's surface profile are captured by a digital CCD camera. While each frames are captured, required π/2 phase shifts for interference fringe pattern are obtained by mechanically sliding the Lloyd assembly via an ordinary micrometer stage. Some preprocess algorithms are applied to the frames and are processed with an algorithm to accomplish 3D topographies. Finally, the continuous data determines the depth information and the surface topography of the object. The experimental setup is simple and low cost to construct, and is insensitive to the ambient temperature fluctuations and environmental vibrations that cause unwanted effects on the projected fringe pattern. Such a fiber optic Lloyd's system which provides an accurate non-contact measurement without contaminating and harming the object surface has a wide range of applications from laser interference based lithography in nano-scale to macro-scale interferometers.

  18. 3D refractive index measurements of special optical fibers

    NASA Astrophysics Data System (ADS)

    Yan, Cheng; Huang, Su-Juan; Miao, Zhuang; Chang, Zheng; Zeng, Jun-Zhang; Wang, Ting-Yun

    2016-09-01

    A digital holographic microscopic chromatography-based approach with considerably improved accuracy, simplified configuration and performance stability is proposed to measure three dimensional refractive index of special optical fibers. Based on the approach, a measurement system is established incorporating a modified Mach-Zehnder interferometer and lab-developed supporting software for data processing. In the system, a phase projection distribution of an optical fiber is utilized to obtain an optimal digital hologram recorded by a CCD, and then an angular spectrum theory-based algorithm is adopted to extract the phase distribution information of an object wave. The rotation of the optic fiber enables the experimental measurements of multi-angle phase information. Based on the filtered back projection algorithm, a 3D refraction index of the optical fiber is thus obtained at high accuracy. To evaluate the proposed approach, both PANDA fibers and special elliptical optical fiber are considered in the system. The results measured in PANDA fibers agree well with those measured using S14 Refractive Index Profiler, which is, however, not suitable for measuring the property of a special elliptical fiber.

  19. Synthesizing 3D Surfaces from Parameterized Strip Charts

    NASA Technical Reports Server (NTRS)

    Robinson, Peter I.; Gomez, Julian; Morehouse, Michael; Gawdiak, Yuri

    2004-01-01

    We believe 3D information visualization has the power to unlock new levels of productivity in the monitoring and control of complex processes. Our goal is to provide visual methods to allow for rapid human insight into systems consisting of thousands to millions of parameters. We explore this hypothesis in two complex domains: NASA program management and NASA International Space Station (ISS) spacecraft computer operations. We seek to extend a common form of visualization called the strip chart from 2D to 3D. A strip chart can display the time series progression of a parameter and allows for trends and events to be identified. Strip charts can be overlayed when multiple parameters need to visualized in order to correlate their events. When many parameters are involved, the direct overlaying of strip charts can become confusing and may not fully utilize the graphing area to convey the relationships between the parameters. We provide a solution to this problem by generating 3D surfaces from parameterized strip charts. The 3D surface utilizes significantly more screen area to illustrate the differences in the parameters and the overlayed strip charts, and it can rapidly be scanned by humans to gain insight. The selection of the third dimension must be a parallel or parameterized homogenous resource in the target domain, defined using a finite, ordered, enumerated type, and not a heterogeneous type. We demonstrate our concepts with examples from the NASA program management domain (assessing the state of many plans) and the computers of the ISS (assessing the state of many computers). We identify 2D strip charts in each domain and show how to construct the corresponding 3D surfaces. The user can navigate the surface, zooming in on regions of interest, setting a mark and drilling down to source documents from which the data points have been derived. We close by discussing design issues, related work, and implementation challenges.

  20. Surface classification and detection of latent fingerprints based on 3D surface texture parameters

    NASA Astrophysics Data System (ADS)

    Gruhn, Stefan; Fischer, Robert; Vielhauer, Claus

    2012-06-01

    In the field of latent fingerprint detection in crime scene forensics the classification of surfaces has importance. A new method for the scientific analysis of image based information for forensic science was investigated in the last years. Our image acquisition based on a sensor using Chromatic White Light (CWL) with a lateral resolution up to 2 μm. The used FRT-MicroProf 200 CWL 600 measurement device is able to capture high-resolution intensity and topography images in an optical and contact-less way. In prior work, we have suggested to use 2D surface texture parameters to classify various materials, which was a novel approach in the field of criminalistic forensic using knowledge from surface appearance and a chromatic white light sensor. A meaningful and useful classification of different crime scene specific surfaces is not existent. In this work, we want to extend such considerations by the usage of fourteen 3D surface parameters, called 'Birmingham 14'. In our experiment we define these surface texture parameters and use them to classify ten different materials in this test set-up and create specific material classes. Further it is shown in first experiments, that some surface texture parameters are sensitive to separate fingerprints from carrier surfaces. So far, the use of surface roughness is mainly known within the framework of material quality control. The analysis and classification of the captured 3D-topography images from crime scenes is important for the adaptive preprocessing depending on the surface texture. The adaptive preprocessing in dependency of surface classification is necessary for precise detection because of the wide variety of surface textures. We perform a preliminary study in usage of these 3D surface texture parameters as feature for the fingerprint detection. In combination with a reference sample we show that surface texture parameters can be an indication for a fingerprint and can be a feature in latent fingerprint detection.

  1. 3D surface configuration modulates 2D symmetry detection.

    PubMed

    Chen, Chien-Chung; Sio, Lok-Teng

    2015-02-01

    We investigated whether three-dimensional (3D) information in a scene can affect symmetry detection. The stimuli were random dot patterns with 15% dot density. We measured the coherence threshold, or the proportion of dots that were the mirror reflection of the other dots in the other half of the image about a central vertical axis, at 75% accuracy with a 2AFC paradigm under various 3D configurations produced by the disparity between the left and right eye images. The results showed that symmetry detection was difficult when the corresponding dots across the symmetry axis were on different frontoparallel or inclined planes. However, this effect was not due to a difference in distance, as the observers could detect symmetry on a slanted surface, where the depth of the two sides of the symmetric axis was different. The threshold was reduced for a hinge configuration where the join of two slanted surfaces coincided with the axis of symmetry. Our result suggests that the detection of two-dimensional (2D) symmetry patterns is subject to the 3D configuration of the scene; and that coplanarity across the symmetry axis and consistency between the 2D pattern and 3D structure are important factors for symmetry detection.

  2. Objective breast symmetry evaluation using 3-D surface imaging.

    PubMed

    Eder, Maximilian; Waldenfels, Fee V; Swobodnik, Alexandra; Klöppel, Markus; Pape, Ann-Kathrin; Schuster, Tibor; Raith, Stefan; Kitzler, Elena; Papadopulos, Nikolaos A; Machens, Hans-Günther; Kovacs, Laszlo

    2012-04-01

    This study develops an objective breast symmetry evaluation using 3-D surface imaging (Konica-Minolta V910(®) scanner) by superimposing the mirrored left breast over the right and objectively determining the mean 3-D contour difference between the 2 breast surfaces. 3 observers analyzed the evaluation protocol precision using 2 dummy models (n = 60), 10 test subjects (n = 300), clinically tested it on 30 patients (n = 900) and compared it to established 2-D measurements on 23 breast reconstructive patients using the BCCT.core software (n = 690). Mean 3-D evaluation precision, expressed as the coefficient of variation (VC), was 3.54 ± 0.18 for all human subjects without significant intra- and inter-observer differences (p > 0.05). The 3-D breast symmetry evaluation is observer independent, significantly more precise (p < 0.001) than the BCCT.core software (VC = 6.92 ± 0.88) and may play a part in an objective surgical outcome analysis after incorporation into clinical practice.

  3. Quantitative 3D Optical Imaging: Applications in Dosimetry and Biophysics

    NASA Astrophysics Data System (ADS)

    Thomas, Andrew Stephen

    Optical-CT has been shown to be a potentially useful imaging tool for the two very different spheres of biologists and radiation therapy physicists, but it has yet to live up to that potential. In radiation therapy, researchers have used optical-CT for the readout of 3D dosimeters, but it is yet to be a clinically relevant tool as the technology is too slow to be considered practical. Biologists have used the technique for structural imaging, but have struggled with emission tomography as the reality of photon attenuation for both excitation and emission have made the images quantitatively irrelevant. Dosimetry. The DLOS (Duke Large field of view Optical-CT Scanner) was designed and constructed to make 3D dosimetry utilizing optical-CT a fast and practical tool while maintaining the accuracy of readout of the previous, slower readout technologies. Upon construction/optimization/implementation of several components including a diffuser, band pass filter, registration mount & fluid filtration system the dosimetry system provides high quality data comparable to or exceeding that of commercial products. In addition, a stray light correction algorithm was tested and implemented. The DLOS in combination with the 3D dosimeter it was designed for, PREAGETM, then underwent rigorous commissioning and benchmarking tests validating its performance against gold standard data including a set of 6 irradiations. DLOS commissioning tests resulted in sub-mm isotropic spatial resolution (MTF >0.5 for frequencies of 1.5lp/mm) and a dynamic range of ˜60dB. Flood field uniformity was 10% and stable after 45minutes. Stray light proved to be small, due to telecentricity, but even the residual can be removed through deconvolution. Benchmarking tests showed the mean 3D passing gamma rate (3%, 3mm, 5% dose threshold) over the 6 benchmark data sets was 97.3% +/- 0.6% (range 96%-98%) scans totaling ˜10 minutes, indicating excellent ability to perform 3D dosimetry while improving the speed of

  4. 3D mapping of elastic modulus using shear wave optical micro-elastography

    PubMed Central

    Zhu, Jiang; Qi, Li; Miao, Yusi; Ma, Teng; Dai, Cuixia; Qu, Yueqiao; He, Youmin; Gao, Yiwei; Zhou, Qifa; Chen, Zhongping

    2016-01-01

    Elastography provides a powerful tool for histopathological identification and clinical diagnosis based on information from tissue stiffness. Benefiting from high resolution, three-dimensional (3D), and noninvasive optical coherence tomography (OCT), optical micro-elastography has the ability to determine elastic properties with a resolution of ~10 μm in a 3D specimen. The shear wave velocity measurement can be used to quantify the elastic modulus. However, in current methods, shear waves are measured near the surface with an interference of surface waves. In this study, we developed acoustic radiation force (ARF) orthogonal excitation optical coherence elastography (ARFOE-OCE) to visualize shear waves in 3D. This method uses acoustic force perpendicular to the OCT beam to excite shear waves in internal specimens and uses Doppler variance method to visualize shear wave propagation in 3D. The measured propagation of shear waves agrees well with the simulation results obtained from finite element analysis (FEA). Orthogonal acoustic excitation allows this method to measure the shear modulus in a deeper specimen which extends the elasticity measurement range beyond the OCT imaging depth. The results show that the ARFOE-OCE system has the ability to noninvasively determine the 3D elastic map. PMID:27762276

  5. Satellite and Surface Data Synergy for Developing a 3D Cloud Structure and Properties Characterization Over the ARM SGP. Stage 1: Cloud Amounts, Optical Depths, and Cloud Heights Reconciliation

    NASA Technical Reports Server (NTRS)

    Genkova, I.; Long, C. N.; Heck, P. W.; Minnis, P.

    2003-01-01

    One of the primary Atmospheric Radiation Measurement (ARM) Program objectives is to obtain measurements applicable to the development of models for better understanding of radiative processes in the atmosphere. We address this goal by building a three-dimensional (3D) characterization of the cloud structure and properties over the ARM Southern Great Plains (SGP). We take the approach of juxtaposing the cloud properties as retrieved from independent satellite and ground-based retrievals, and looking at the statistics of the cloud field properties. Once these retrievals are well understood, they will be used to populate the 3D characterization database. As a first step we determine the relationship between surface fractional sky cover and satellite viewing angle dependent cloud fraction (CF). We elaborate on the agreement intercomparing optical depth (OD) datasets from satellite and ground using available retrieval algorithms with relation to the CF, cloud height, multi-layer cloud presence, and solar zenith angle (SZA). For the SGP Central Facility, where output from the active remote sensing cloud layer (ARSCL) valueadded product (VAP) is available, we study the uncertainty of satellite estimated cloud heights and evaluate the impact of this uncertainty for radiative studies.

  6. Ultracold polar molecules in a 3D optical lattice

    NASA Astrophysics Data System (ADS)

    Yan, Bo

    2015-05-01

    Ultracold polar molecules, with their long-range electric dipolar interactions, offer new opportunities for studying quantum magnetism and many-body physics. KRb molecules loaded into a three-dimensional (3D) optical lattice allow one to study such a spin-lattice system in a stable environment without losses arising from chemical reactions. In the case with strong lattice confinement along two directions and a weak lattice potential along the third, we find the loss rate is suppressed by the quantum Zeno effect. In a deep 3D lattice with no tunneling, we observe evidences for spin exchange interactions. We use Ramsey spectroscopy to investigate the spin dynamics. By choosing the appropriate lattice polarizations and implementing a spin echo sequence, the single particle dephasing is largely suppressed, leaving the dipolar exchange interactions as the dominant contribution to the observed dynamics. This is supported by many-body theoretical calculations. While this initial demonstration was done with low lattice fillings, our current experimental efforts are focused on increasing the lattice filling fraction. This will greatly benefit the study of complex many-body dynamics with long-range interactions, such as transport of excitations in an out-of-equilibrium system and spin-orbit coupling in a lattice.

  7. Characterisation of the surface structure of 3D printed scaffolds for cell infiltration and surgical suturing.

    PubMed

    Ruiz-Cantu, Laura; Gleadall, Andrew; Faris, Callum; Segal, Joel; Shakesheff, Kevin; Yang, Jing

    2016-03-01

    3D printing is of great interest for tissue engineering scaffolds due to the ability to form complex geometries and control internal structures, including porosity and pore size. The porous structure of scaffolds plays an important role in cell ingrowth and nutrition infusion. Although the internal porosity and pore size of 3D printed scaffolds have been frequently studied, the surface porosity and pore size, which are critical for cell infiltration and mass transport, have not been investigated. The surface geometry can differ considerably from the internal scaffold structure depending on the 3D printing process. It is vital to be able to control the surface geometry of scaffolds as well as the internal structure to fabricate optimal architectures. This work presents a method to control the surface porosity and pore size of 3D printed scaffolds. Six scaffold designs have been printed with surface porosities ranging from 3% to 21%. We have characterised the overall scaffold porosity and surface porosity using optical microscopy and microCT. It has been found that surface porosity has a significant impact on cell infiltration and proliferation. In addition, the porosity of the surface has been found to have an effect on mechanical properties and on the forces required to penetrate the scaffold with a surgical suturing needle. To the authors' knowledge, this study is the first to investigate the surface geometry of extrusion-based 3D printed scaffolds and demonstrates the importance of surface geometry in cell infiltration and clinical manipulation. PMID:26930179

  8. Characterisation of the surface structure of 3D printed scaffolds for cell infiltration and surgical suturing.

    PubMed

    Ruiz-Cantu, Laura; Gleadall, Andrew; Faris, Callum; Segal, Joel; Shakesheff, Kevin; Yang, Jing

    2016-03-01

    3D printing is of great interest for tissue engineering scaffolds due to the ability to form complex geometries and control internal structures, including porosity and pore size. The porous structure of scaffolds plays an important role in cell ingrowth and nutrition infusion. Although the internal porosity and pore size of 3D printed scaffolds have been frequently studied, the surface porosity and pore size, which are critical for cell infiltration and mass transport, have not been investigated. The surface geometry can differ considerably from the internal scaffold structure depending on the 3D printing process. It is vital to be able to control the surface geometry of scaffolds as well as the internal structure to fabricate optimal architectures. This work presents a method to control the surface porosity and pore size of 3D printed scaffolds. Six scaffold designs have been printed with surface porosities ranging from 3% to 21%. We have characterised the overall scaffold porosity and surface porosity using optical microscopy and microCT. It has been found that surface porosity has a significant impact on cell infiltration and proliferation. In addition, the porosity of the surface has been found to have an effect on mechanical properties and on the forces required to penetrate the scaffold with a surgical suturing needle. To the authors' knowledge, this study is the first to investigate the surface geometry of extrusion-based 3D printed scaffolds and demonstrates the importance of surface geometry in cell infiltration and clinical manipulation.

  9. Molecular cartography of the human skin surface in 3D

    PubMed Central

    Bouslimani, Amina; Porto, Carla; Rath, Christopher M.; Wang, Mingxun; Guo, Yurong; Gonzalez, Antonio; Berg-Lyon, Donna; Ackermann, Gail; Moeller Christensen, Gitte Julie; Nakatsuji, Teruaki; Zhang, Lingjuan; Borkowski, Andrew W.; Meehan, Michael J.; Dorrestein, Kathleen; Gallo, Richard L.; Bandeira, Nuno; Knight, Rob; Alexandrov, Theodore; Dorrestein, Pieter C.

    2015-01-01

    The human skin is an organ with a surface area of 1.5–2 m2 that provides our interface with the environment. The molecular composition of this organ is derived from host cells, microbiota, and external molecules. The chemical makeup of the skin surface is largely undefined. Here we advance the technologies needed to explore the topographical distribution of skin molecules, using 3D mapping of mass spectrometry data and microbial 16S rRNA amplicon sequences. Our 3D maps reveal that the molecular composition of skin has diverse distributions and that the composition is defined not only by skin cells and microbes but also by our daily routines, including the application of hygiene products. The technological development of these maps lays a foundation for studying the spatial relationships of human skin with hygiene, the microbiota, and environment, with potential for developing predictive models of skin phenotypes tailored to individual health. PMID:25825778

  10. Molecular cartography of the human skin surface in 3D.

    PubMed

    Bouslimani, Amina; Porto, Carla; Rath, Christopher M; Wang, Mingxun; Guo, Yurong; Gonzalez, Antonio; Berg-Lyon, Donna; Ackermann, Gail; Moeller Christensen, Gitte Julie; Nakatsuji, Teruaki; Zhang, Lingjuan; Borkowski, Andrew W; Meehan, Michael J; Dorrestein, Kathleen; Gallo, Richard L; Bandeira, Nuno; Knight, Rob; Alexandrov, Theodore; Dorrestein, Pieter C

    2015-04-28

    The human skin is an organ with a surface area of 1.5-2 m(2) that provides our interface with the environment. The molecular composition of this organ is derived from host cells, microbiota, and external molecules. The chemical makeup of the skin surface is largely undefined. Here we advance the technologies needed to explore the topographical distribution of skin molecules, using 3D mapping of mass spectrometry data and microbial 16S rRNA amplicon sequences. Our 3D maps reveal that the molecular composition of skin has diverse distributions and that the composition is defined not only by skin cells and microbes but also by our daily routines, including the application of hygiene products. The technological development of these maps lays a foundation for studying the spatial relationships of human skin with hygiene, the microbiota, and environment, with potential for developing predictive models of skin phenotypes tailored to individual health.

  11. Molecular cartography of the human skin surface in 3D.

    PubMed

    Bouslimani, Amina; Porto, Carla; Rath, Christopher M; Wang, Mingxun; Guo, Yurong; Gonzalez, Antonio; Berg-Lyon, Donna; Ackermann, Gail; Moeller Christensen, Gitte Julie; Nakatsuji, Teruaki; Zhang, Lingjuan; Borkowski, Andrew W; Meehan, Michael J; Dorrestein, Kathleen; Gallo, Richard L; Bandeira, Nuno; Knight, Rob; Alexandrov, Theodore; Dorrestein, Pieter C

    2015-04-28

    The human skin is an organ with a surface area of 1.5-2 m(2) that provides our interface with the environment. The molecular composition of this organ is derived from host cells, microbiota, and external molecules. The chemical makeup of the skin surface is largely undefined. Here we advance the technologies needed to explore the topographical distribution of skin molecules, using 3D mapping of mass spectrometry data and microbial 16S rRNA amplicon sequences. Our 3D maps reveal that the molecular composition of skin has diverse distributions and that the composition is defined not only by skin cells and microbes but also by our daily routines, including the application of hygiene products. The technological development of these maps lays a foundation for studying the spatial relationships of human skin with hygiene, the microbiota, and environment, with potential for developing predictive models of skin phenotypes tailored to individual health. PMID:25825778

  12. Volumetric (3D) compressive sensing spectral domain optical coherence tomography

    PubMed Central

    Xu, Daguang; Huang, Yong; Kang, Jin U.

    2014-01-01

    In this work, we proposed a novel three-dimensional compressive sensing (CS) approach for spectral domain optical coherence tomography (SD OCT) volumetric image acquisition and reconstruction. Instead of taking a spectral volume whose size is the same as that of the volumetric image, our method uses a sub set of the original spectral volume that is under-sampled in all three dimensions, which reduces the amount of spectral measurements to less than 20% of that required by the Shan-non/Nyquist theory. The 3D image is recovered from the under-sampled spectral data dimension-by-dimension using the proposed three-step CS reconstruction strategy. Experimental results show that our method can significantly reduce the sampling rate required for a volumetric SD OCT image while preserving the image quality. PMID:25426320

  13. Volumetric (3D) compressive sensing spectral domain optical coherence tomography.

    PubMed

    Xu, Daguang; Huang, Yong; Kang, Jin U

    2014-11-01

    In this work, we proposed a novel three-dimensional compressive sensing (CS) approach for spectral domain optical coherence tomography (SD OCT) volumetric image acquisition and reconstruction. Instead of taking a spectral volume whose size is the same as that of the volumetric image, our method uses a sub set of the original spectral volume that is under-sampled in all three dimensions, which reduces the amount of spectral measurements to less than 20% of that required by the Shan-non/Nyquist theory. The 3D image is recovered from the under-sampled spectral data dimension-by-dimension using the proposed three-step CS reconstruction strategy. Experimental results show that our method can significantly reduce the sampling rate required for a volumetric SD OCT image while preserving the image quality.

  14. Real-time 3D surface-image-guided beam setup in radiotherapy of breast cancer

    SciTech Connect

    Djajaputra, David; Li Shidong

    2005-01-01

    We describe an approach for external beam radiotherapy of breast cancer that utilizes the three-dimensional (3D) surface information of the breast. The surface data of the breast are obtained from a 3D optical camera that is rigidly mounted on the ceiling of the treatment vault. This 3D camera utilizes light in the visible range therefore it introduces no ionization radiation to the patient. In addition to the surface topographical information of the treated area, the camera also captures gray-scale information that is overlaid on the 3D surface image. This allows us to visualize the skin markers and automatically determine the isocenter position and the beam angles in the breast tangential fields. The field sizes and shapes of the tangential, supraclavicular, and internal mammary gland fields can all be determined according to the 3D surface image of the target. A least-squares method is first introduced for the tangential-field setup that is useful for compensation of the target shape changes. The entire process of capturing the 3D surface data and subsequent calculation of beam parameters typically requires less than 1 min. Our tests on phantom experiments and patient images have achieved the accuracy of 1 mm in shift and 0.5 deg. in rotation. Importantly, the target shape and position changes in each treatment session can both be corrected through this real-time image-guided system.

  15. Design Application Translates 2-D Graphics to 3-D Surfaces

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Fabric Images Inc., specializing in the printing and manufacturing of fabric tension architecture for the retail, museum, and exhibit/tradeshow communities, designed software to translate 2-D graphics for 3-D surfaces prior to print production. Fabric Images' fabric-flattening design process models a 3-D surface based on computer-aided design (CAD) specifications. The surface geometry of the model is used to form a 2-D template, similar to a flattening process developed by NASA's Glenn Research Center. This template or pattern is then applied in the development of a 2-D graphic layout. Benefits of this process include 11.5 percent time savings per project, less material wasted, and the ability to improve upon graphic techniques and offer new design services. Partners include Exhibitgroup/Giltspur (end-user client: TAC Air, a division of Truman Arnold Companies Inc.), Jack Morton Worldwide (end-user client: Nickelodeon), as well as 3D Exhibits Inc., and MG Design Associates Corp.

  16. Study of 3D printing method for GRIN micro-optics devices

    NASA Astrophysics Data System (ADS)

    Wang, P. J.; Yeh, J. A.; Hsu, W. Y.; Cheng, Y. C.; Lee, W.; Wu, N. H.; Wu, C. Y.

    2016-03-01

    Conventional optical elements are based on either refractive or reflective optics theory to fulfill the design specifications via optics performance data. In refractive optical lenses, the refractive index of materials and radius of curvature of element surfaces determine the optical power and wavefront aberrations so that optical performance can be further optimized iteratively. Although gradient index (GRIN) phenomenon in optical materials is well studied for more than a half century, the optics theory in lens design via GRIN materials is still yet to be comprehensively investigated before realistic GRIN lenses are manufactured. In this paper, 3D printing method for manufacture of micro-optics devices with special features has been studied based on methods reported in the literatures. Due to the additive nature of the method, GRIN lenses in micro-optics devices seem to be readily achievable if a design methodology is available. First, derivation of ray-tracing formulae is introduced for all possible structures in GRIN lenses. Optics simulation program is employed for characterization of GRIN lenses with performance data given by aberration coefficients in Zernike polynomial. Finally, a proposed structure of 3D printing machine is described with conceptual illustration.

  17. Real-time 3D-surface-guided head refixation useful for fractionated stereotactic radiotherapy

    SciTech Connect

    Li Shidong; Liu Dezhi; Yin Gongjie; Zhuang Ping; Geng, Jason

    2006-02-15

    Accurate and precise head refixation in fractionated stereotactic radiotherapy has been achieved through alignment of real-time 3D-surface images with a reference surface image. The reference surface image is either a 3D optical surface image taken at simulation with the desired treatment position, or a CT/MRI-surface rendering in the treatment plan with corrections for patient motion during CT/MRI scans and partial volume effects. The real-time 3D surface images are rapidly captured by using a 3D video camera mounted on the ceiling of the treatment vault. Any facial expression such as mouth opening that affects surface shape and location can be avoided using a new facial monitoring technique. The image artifacts on the real-time surface can generally be removed by setting a threshold of jumps at the neighboring points while preserving detailed features of the surface of interest. Such a real-time surface image, registered in the treatment machine coordinate system, provides a reliable representation of the patient head position during the treatment. A fast automatic alignment between the real-time surface and the reference surface using a modified iterative-closest-point method leads to an efficient and robust surface-guided target refixation. Experimental and clinical results demonstrate the excellent efficacy of <2 min set-up time, the desired accuracy and precision of <1 mm in isocenter shifts, and <1 deg. in rotation.

  18. Investigation Into the Accuracy of 3D Surface Roughness Characteristics

    NASA Astrophysics Data System (ADS)

    Kumermanis, M.; Rudzitis, J.; Mozga, N.; Ancans, A.; Grislis, A.

    2014-04-01

    The existing standards for surface roughness cover only two dimensions, while in reality this is three-dimensional (3D). In particular, the 3D surface roughness parameters are important for solving the contact surface mechanics problems as related to the accuracy of 3D surface roughness characteristics. One of the most important factors for determination of 3D characteristics is the number of data points (NDP) on the x- and y-axes (i.e. in cut-off length). The NDP has a profound effect on the accuracy of measurement results, measuring time and volume of the output data (especially along the y-axis, where the NDP is identical to the number of parallel profiles). At a too small NDP the results will be incorrect and with too broad scatter, while a too large NDP - though not enlarging the range of basic information - considerably increases the measuring time. Therefore, the aim of the work was to find the optimal NDP for such surface processing methods as grinding, spark erosion and shot methods of surface treatment. Eksistējošie virsmas raupjuma standarti apskata virsmas raupjumu tikai divās dimensijās. Tomēr reālais virsmas raupjums pēc savas dabas ir trīsdimensiju (3D) objekts. Līdz ar to virsmas raupjums ir jāraksturo ar 3D parametriem. Un no šo parametru noteikšanas precizitātes ir atkarīgi tālākie virsmas aprēķini, piemēram, virsmu kontaktēšanās process. Viens no svarīgākajiem faktoriem, raksturojot virsmas raupjumu 3D, pielietojot kontakta tipa mēriekārtas, ir datu punktu skaits pa abām mērīšanas asīm x un y. Ar datu punktu skaitu mēs saprotam to skaitu mērīšanas bāzes garumā. Datu punktu skaits būtiski ietekmē sagaidāmo mērījumu rezultātu precizitāti, mērīšanai nepieciešamo laiku un izejas datu faila izmērus (sevišķi y-ass virzienā, kur katrs datu punkts ir paralēls profils). Datu punktu skaitam ir jābūt optimālam. Pārāk mazs punktu skaits noved pie neprecīziem rezultātiem un lielas to izkliedes, savuk

  19. Visualizing 3D velocity fields near contour surfaces. Revision 1

    SciTech Connect

    Max, N.; Crawfis, R.; Grant, C.

    1994-08-08

    Vector field rendering is difficult in 3D because the vector icons overlap and hide each other. We propose four different techniques for visualizing vector fields only near surfaces. The first uses motion blurred particles in a thickened region around the surface. The second uses a voxel grid to contain integral curves of the vector field. The third uses many antialiased lines through the surface, and the fourth uses hairs sprouting from the surface and then bending in the direction of the vector field. All the methods use the graphics pipeline, allowing real time rotation and interaction, and the first two methods can animate the texture to move in the flow determined by the velocity field.

  20. Visualizing 3D velocity fields near contour surfaces

    SciTech Connect

    Max, N.; Crawfis, R.; Grant, C.

    1994-03-01

    Vector field rendering is difficult in 3D because the vector icons overlap and hide each other. We propose four different techniques for visualizing vector fields only near surfaces. The first uses motion blurred particles in a thickened region around the surface. The second uses a voxel grid to contain integral curves of the vector field. The third uses many antialiased lines through the surface, and the fourth uses hairs sprouting from the surface and then bending in the direction of the vector field. All the methods use the graphite pipeline, allowing real time rotation and interaction, and the first two methods can animate the texture to move in the flow determined by the velocity field.

  1. 3D surface topology guides stem cell adhesion and differentiation.

    PubMed

    Viswanathan, Priyalakshmi; Ondeck, Matthew G; Chirasatitsin, Somyot; Ngamkham, Kamolchanok; Reilly, Gwendolen C; Engler, Adam J; Battaglia, Giuseppe

    2015-06-01

    Polymerized high internal phase emulsion (polyHIPE) foams are extremely versatile materials for investigating cell-substrate interactions in vitro. Foam morphologies can be controlled by polymerization conditions to result in either open or closed pore structures with different levels of connectivity, consequently enabling the comparison between 2D and 3D matrices using the same substrate with identical surface chemistry conditions. Additionally, here we achieve the control of pore surface topology (i.e. how different ligands are clustered together) using amphiphilic block copolymers as emulsion stabilizers. We demonstrate that adhesion of human mesenchymal progenitor (hES-MP) cells cultured on polyHIPE foams is dependent on foam surface topology and chemistry but is independent of porosity and interconnectivity. We also demonstrate that the interconnectivity, architecture and surface topology of the foams has an effect on the osteogenic differentiation potential of hES-MP cells. Together these data demonstrate that the adhesive heterogeneity of a 3D scaffold could regulate not only mesenchymal stem cell attachment but also cell behavior in the absence of soluble growth factors.

  2. 3D Surface Topology Guides Stem Cell Adhesion and Differentiation

    PubMed Central

    Viswanathan, Priyalakshmi; Ondeck, Matthew G.; Chirasatitsin, Somyot; Nghamkham, Kamolchanok; Reilly, Gwendolen C.; Engler, Adam J.; Battaglia, Giuseppe

    2015-01-01

    Polymerized high internal phase emulsion (polyHIPE) foams are extremely versatile materials for investigating cell-substrate interactions in vitro. Foam morphologies can be controlled by polymerization conditions to result in either open or closed pore structures with different levels of connectivity, consequently enabling the comparison between 2D and 3D matrices using the same substrate with identical surface chemistry conditions. Additionally, here we achieve the control of pore surface topology (i.e. how different ligands are clustered together) using amphiphilic block copolymers as emulsion stabilisers. We demonstrate that adhesion of human mesenchymal progenitor (hES-MP) cells cultured on polyHIPE foams is dependent on foam surface topology and chemistry but is independent of porosity and interconnectivity. We also demonstrate that the interconnectivity, architecture and surface topology of the foams has an effect on the osteogenic differentiation potential of hES-MP cells. Together these data demonstrate that the adhesive heterogeneity of a 3D scaffold could regulate not only mesenchymal stem cell attachment but also cell behavior in the absence of soluble growth factors. PMID:25818420

  3. A 3D integral imaging optical see-through head-mounted display.

    PubMed

    Hua, Hong; Javidi, Bahram

    2014-06-01

    An optical see-through head-mounted display (OST-HMD), which enables optical superposition of digital information onto the direct view of the physical world and maintains see-through vision to the real world, is a vital component in an augmented reality (AR) system. A key limitation of the state-of-the-art OST-HMD technology is the well-known accommodation-convergence mismatch problem caused by the fact that the image source in most of the existing AR displays is a 2D flat surface located at a fixed distance from the eye. In this paper, we present an innovative approach to OST-HMD designs by combining the recent advancement of freeform optical technology and microscopic integral imaging (micro-InI) method. A micro-InI unit creates a 3D image source for HMD viewing optics, instead of a typical 2D display surface, by reconstructing a miniature 3D scene from a large number of perspective images of the scene. By taking advantage of the emerging freeform optical technology, our approach will result in compact, lightweight, goggle-style AR display that is potentially less vulnerable to the accommodation-convergence discrepancy problem and visual fatigue. A proof-of-concept prototype system is demonstrated, which offers a goggle-like compact form factor, non-obstructive see-through field of view, and true 3D virtual display.

  4. Effective 3-D surface modeling for geographic information systems

    NASA Astrophysics Data System (ADS)

    Yüksek, K.; Alparslan, M.; Mendi, E.

    2016-01-01

    In this work, we propose a dynamic, flexible and interactive urban digital terrain platform with spatial data and query processing capabilities of geographic information systems, multimedia database functionality and graphical modeling infrastructure. A new data element, called Geo-Node, which stores image, spatial data and 3-D CAD objects is developed using an efficient data structure. The system effectively handles data transfer of Geo-Nodes between main memory and secondary storage with an optimized directional replacement policy (DRP) based buffer management scheme. Polyhedron structures are used in digital surface modeling and smoothing process is performed by interpolation. The experimental results show that our framework achieves high performance and works effectively with urban scenes independent from the amount of spatial data and image size. The proposed platform may contribute to the development of various applications such as Web GIS systems based on 3-D graphics standards (e.g., X3-D and VRML) and services which integrate multi-dimensional spatial information and satellite/aerial imagery.

  5. Cordless hand-held optical 3D sensor

    NASA Astrophysics Data System (ADS)

    Munkelt, Christoph; Bräuer-Burchardt, Christian; Kühmstedt, Peter; Schmidt, Ingo; Notni, Gunther

    2007-07-01

    A new mobile optical 3D measurement system using phase correlation based fringe projection technique will be presented. The sensor consist of a digital projection unit and two cameras in a stereo arrangement, whereby both are battery powered. The data transfer to a base station will be done via WLAN. This gives the possibility to use the system in complicate, remote measurement situations, which are typical in archaeology and architecture. In the measurement procedure the sensor will be hand-held by the user, illuminating the object with a sequence of less than 10 fringe patterns, within a time below 200 ms. This short sequence duration was achieved by a new approach, which combines the epipolar constraint with robust phase correlation utilizing a pre-calibrated sensor head, containing two cameras and a digital fringe projector. Furthermore, the system can be utilized to acquire the all around shape of objects by using the phasogrammetric approach with virtual land marks introduced by the authors 1, 2. This way no matching procedures or markers are necessary for the registration of multiple views, which makes the system very flexible in accomplishing different measurement tasks. The realized measurement field is approx. 100 mm up to 400 mm in diameter. The mobile character makes the measurement system useful for a wide range of applications in arts, architecture, archaeology and criminology, which will be shown in the paper.

  6. Brain surface maps from 3-D medical images

    NASA Astrophysics Data System (ADS)

    Lu, Jiuhuai; Hansen, Eric W.; Gazzaniga, Michael S.

    1991-06-01

    The anatomic and functional localization of brain lesions for neurologic diagnosis and brain surgery is facilitated by labeling the cortical surface in 3D images. This paper presents a method which extracts cortical contours from magnetic resonance (MR) image series and then produces a planar surface map which preserves important anatomic features. The resultant map may be used for manual anatomic localization as well as for further automatic labeling. Outer contours are determined on MR cross-sectional images by following the clear boundaries between gray matter and cerebral-spinal fluid, skipping over sulci. Carrying this contour below the surface by shrinking it along its normal produces an inner contour that alternately intercepts gray matter (sulci) and white matter along its length. This procedure is applied to every section in the set, and the image (grayscale) values along the inner contours are radially projected and interpolated onto a semi-cylindrical surface with axis normal to the slices and large enough to cover the whole brain. A planar map of the cortical surface results by flattening this cylindrical surface. The projection from inner contour to cylindrical surface is unique in the sense that different points on the inner contour correspond to different points on the cylindrical surface. As the outer contours are readily obtained by automatic segmentation, cortical maps can be made directly from an MR series.

  7. Axial-Stereo 3-D Optical Metrology for Inner Profile of Pipes Using a Scanning Laser Endoscope

    PubMed Central

    Gong, Yuanzheng; Johnston, Richard S.; Melville, C. David; Seibel, Eric J.

    2015-01-01

    As the rapid progress in the development of optoelectronic components and computational power, 3D optical metrology becomes more and more popular in manufacturing and quality control due to its flexibility and high speed. However, most of the optical metrology methods are limited to external surfaces. This paper proposed a new approach to measure tiny internal 3D surfaces with a scanning fiber endoscope and axial-stereo vision algorithm. A dense, accurate point cloud of internally machined threads was generated to compare with its corresponding X-ray 3D data as ground truth, and the quantification was analyzed by Iterative Closest Points algorithm. PMID:26640425

  8. Axial-Stereo 3-D Optical Metrology for Inner Profile of Pipes Using a Scanning Laser Endoscope

    NASA Astrophysics Data System (ADS)

    Gong, Yuanzheng; Johnston, Richard S.; Melville, C. David; Seibel, Eric J.

    2015-07-01

    As the rapid progress in the development of optoelectronic components and computational power, 3-D optical metrology becomes more and more popular in manufacturing and quality control due to its flexibility and high speed. However, most of the optical metrology methods are limited to external surfaces. This article proposed a new approach to measure tiny internal 3-D surfaces with a scanning fiber endoscope and axial-stereo vision algorithm. A dense, accurate point cloud of internally machined threads was generated to compare with its corresponding X-ray 3-D data as ground truth, and the quantification was analyzed by Iterative Closest Points algorithm.

  9. Poly(acrylic acid) brushes pattern as a 3D functional biosensor surface for microchips

    NASA Astrophysics Data System (ADS)

    Wang, Yan-Mei; Cui, Yi; Cheng, Zhi-Qiang; Song, Lu-Sheng; Wang, Zhi-You; Han, Bao-Hang; Zhu, Jin-Song

    2013-02-01

    Poly(acrylic acid) (PAA) brushes, a novel three dimensional (3D) precursor layer of biosensor or protein microarrays, possess high protein loading level and low non-specific protein adsorption. In this article, we describe a simple and convenient way to fabricate 3D PAA brushes pattern by microcontact printing (μCP) and characterize it with FT-IR and optical microscopy. The carboxyl groups of PAA brushes can be applied to covalently immobilize protein for immunoassay. Thriving 3D space made by patterning PAA brushes thin film is available to enhance protein immobilization, which is confirmed by measuring model protein interaction between human immunoglobulin G (H-IgG) and goat anti-H-IgG (G-H-IgG) with fluorescence microscopy and surface plasmon resonance imaging (SPRi). As expected, the SPRi signals of H-IgG coating on 3D PAA brushes pattern and further measuring specific binding with G-H-IgG are all larger than that of 3D PAA brushes without pattern and 2D bare gold surface. We further revealed that this surface can be used for high-throughput screening and clinical diagnosis by label-free assaying of Hepatitis-B-Virus surface antibody (HBsAb) with Hepatitis-B-Virus surface antigen (HBsAg) concentration array chip. The linearity range for HBsAb assay is wider than that of conventional ELISA method.

  10. Conveying the 3D Shape of Transparent Surfaces Via Texture

    NASA Technical Reports Server (NTRS)

    Interrante, Victoria; Fuchs, Henry; Pizer, Stephen

    1997-01-01

    Transparency can be a useful device for depicting multiple overlapping surfaces in a single image. The challenge is to render the transparent surfaces in such a way that their three-dimensional shape can be readily understood and their depth distance from underlying structures clearly perceived. This paper describes our investigations into the use of sparsely-distributed discrete, opaque texture as an 'artistic device' for more explicitly indicating the relative depth of a transparent surface and for communicating the essential features of its 3D shape in an intuitively meaningful and minimally occluding way. The driving application for this work is the visualization of layered surfaces in radiation therapy treatment planning data, and the technique is illustrated on transparent isointensity surfaces of radiation dose. We describe the perceptual motivation and artistic inspiration for defining a stroke texture that is locally oriented in the direction of greatest normal curvature (and in which individual strokes are of a length proportional to the magnitude of the curvature in the direction they indicate), and discuss several alternative methods for applying this texture to isointensity surfaces defined in a volume. We propose an experimental paradigm for objectively measuring observers' ability to judge the shape and depth of a layered transparent surface, in the course of a task relevant to the needs of radiotherapy treatment planning, and use this paradigm to evaluate the practical effectiveness of our approach through a controlled observer experiment based on images generated from actual clinical data.

  11. Wear Analysis of Thermal Spray Coatings on 3D Surfaces

    NASA Astrophysics Data System (ADS)

    Tillmann, W.; Luo, W.; Selvadurai, U.

    2014-01-01

    Even though the application of thermal spray coatings on complex geometries gained a greater interest in the last decade, the effect of different geometrical features on the wear behavior is still ill-defined. In this study, the wear resistance of FTC-FeCSiMn coated 3D surfaces was investigated. The wear test was carried out by means of two innovative testing procedures. The first test is a Pin-on-Tubes test where the rotating motion is realized by a lathe chuck. The specimens in the second test were fixed on the table and a robot arm operated the pin. This wear test was applied on specimens with concave or convex surfaces. The residual stresses, which were determined by means of an incremental hole-drilling method, show a dependency on the substrate geometry. The obtained stresses were put in relation to the different radii. After the wear test, a 3D-profilometer determined the wear volume and the sections of the coatings were characterized by a scanning electron microscope. The results indicate that the wear resistance is strongly influenced by the geometry of the substrate.

  12. 3D Additive Construction with Regolith for Surface Systems

    NASA Technical Reports Server (NTRS)

    Mueller, Robert P.

    2014-01-01

    Planetary surface exploration on Asteroids, the Moon, Mars and Martian Moons will require the stabilization of loose, fine, dusty regolith to avoid the effects of vertical lander rocket plume impingement, to keep abrasive and harmful dust from getting lofted and for dust free operations. In addition, the same regolith stabilization process can be used for 3 Dimensional ( 3D) printing, additive construction techniques by repeating the 2D stabilization in many vertical layers. This will allow in-situ construction with regolith so that materials will not have to be transported from Earth. Recent work in the NASA Kennedy Space Center (KSC) Surface Systems Office (NE-S) Swamp Works and at the University of Southern California (USC) under two NASA Innovative Advanced Concept (NIAC) awards have shown promising results with regolith (crushed basalt rock) materials for in-situ heat shields, bricks, landing/launch pads, berms, roads, and other structures that could be fabricated using regolith that is sintered or mixed with a polymer binder. The technical goals and objectives of this project are to prove the feasibility of 3D printing additive construction using planetary regolith simulants and to show that they have structural integrity and practical applications in space exploration.

  13. THE THOMSON SURFACE. III. TRACKING FEATURES IN 3D

    SciTech Connect

    Howard, T. A.; DeForest, C. E.; Tappin, S. J.; Odstrcil, D.

    2013-03-01

    In this, the final installment in a three-part series on the Thomson surface, we present simulated observations of coronal mass ejections (CMEs) observed by a hypothetical polarizing white light heliospheric imager. Thomson scattering yields a polarization signal that can be exploited to locate observed features in three dimensions relative to the Thomson surface. We consider how the appearance of the CME changes with the direction of trajectory, using simulations of a simple geometrical shape and also of a more realistic CME generated using the ENLIL model. We compare the appearance in both unpolarized B and polarized pB light, and show that there is a quantifiable difference in the measured brightness of a CME between unpolarized and polarized observations. We demonstrate a technique for using this difference to extract the three-dimensional (3D) trajectory of large objects such as CMEs. We conclude with a discussion on how a polarizing heliospheric imager could be used to extract 3D trajectory information about CMEs or other observed features.

  14. 3D stochastic geophysical inversion for contact surface geometry

    NASA Astrophysics Data System (ADS)

    Lelièvre, Peter; Farquharson, Colin; Bijani, Rodrigo

    2015-04-01

    Geologists' interpretations about the Earth typically involve distinct rock units with contacts (interfaces) between them. As such, 3D geological Earth models typically comprise wireframe contact surfaces of tessellated triangles or other polygonal planar facets. In contrast, standard minimum-structure geophysical inversions are performed on meshes of space-filling cells (typically prisms or tetrahedra) and recover smoothly varying physical property distributions that are inconsistent with typical geological interpretations. There are several approaches through which mesh-based geophysical inversion can help recover models with some of the desired characteristics. However, a more effective strategy is to consider a fundamentally different type of inversion that works directly with models that comprise surfaces representing contacts between rock units. We are researching such an approach, our goal being to perform geophysical forward and inverse modelling directly with 3D geological models of any complexity. Geological and geophysical models should be specified using the same parameterization such that they are, in essence, the same Earth model. We parameterize the wireframe contact surfaces in a 3D model as the coordinates of the nodes (facet vertices). The physical properties of each rock unit in a model remain fixed while the geophysical inversion controls the position of the contact surfaces via the control nodes, perturbing the surfaces as required to fit the geophysical data responses. This is essentially a "geometry inversion", which can be used to recover the unknown geometry of a target body or to investigate the viability of a proposed Earth model. We apply global optimization strategies to solve the inverse problem, including stochastic sampling to obtain statistical information regarding the likelihood of particular features in the model, helping to assess the viability of a proposed model. Jointly inverting multiple types of geophysical data is simple

  15. Introductory review on `Flying Triangulation': a motion-robust optical 3D measurement principle

    NASA Astrophysics Data System (ADS)

    Ettl, Svenja

    2015-04-01

    'Flying Triangulation' (FlyTri) is a recently developed principle which allows for a motion-robust optical 3D measurement of rough surfaces. It combines a simple sensor with sophisticated algorithms: a single-shot sensor acquires 2D camera images. From each camera image, a 3D profile is generated. The series of 3D profiles generated are aligned to one another by algorithms, without relying on any external tracking device. It delivers real-time feedback of the measurement process which enables an all-around measurement of objects. The principle has great potential for small-space acquisition environments, such as the measurement of the interior of a car, and motion-sensitive measurement tasks, such as the intraoral measurement of teeth. This article gives an overview of the basic ideas and applications of FlyTri. The main challenges and their solutions are discussed. Measurement examples are also given to demonstrate the potential of the measurement principle.

  16. Subtractive 3D printing of optically active diamond structures.

    PubMed

    Martin, Aiden A; Toth, Milos; Aharonovich, Igor

    2014-05-21

    Controlled fabrication of semiconductor nanostructures is an essential step in engineering of high performance photonic and optoelectronic devices. Diamond in particular has recently attracted considerable attention as a promising platform for quantum technologies, photonics and high resolution sensing applications. Here we demonstrate the fabrication of optically active, functional diamond structures using gas-mediated electron beam induced etching (EBIE). The technique achieves dry chemical etching at room temperature through the dissociation of surface-adsorbed H2O molecules by energetic electrons in a water vapor environment. Parallel processing is possible by electron flood exposure and the use of an etch mask, while high resolution, mask-free, iterative editing is demonstrated by direct write etching of inclined facets of diamond microparticles. The realized structures demonstrate the potential of EBIE for the fabrication of optically active structures in diamond.

  17. Simultaneous electrochemical and 3D optical imaging of silver nanoparticle oxidation

    NASA Astrophysics Data System (ADS)

    Batchelor-McAuley, Christopher; Martinez-Marrades, Ariadna; Tschulik, Kristina; Patel, Anisha N.; Combellas, Catherine; Kanoufi, Frédéric; Tessier, Gilles; Compton, Richard G.

    2014-03-01

    The oxidation of AgNPs at a thin-film gold electrode is simultaneously investigated via digital holography and electrochemistry. The use of holography allows, for the first time, the 3D visualization of the electrochemical interfacial region at a relatively high acquisition rate. It is demonstrated how the coupling of these two techniques provides complementary chemical information. The ensemble response of the oxidation of surface-adsorbed silver nanoparticles to AgCl is monitored electrochemically, whereas this process is difficult to observe optically. Conversely, the subsequent chemical dissolution of individual AgCl nanocrystals can be tracked optically due to the associated decrease in the scattered light intensity.

  18. Surface-preserving robust watermarking of 3-D shapes.

    PubMed

    Luo, Ming; Bors, Adrian G

    2011-10-01

    This paper describes a new statistical approach for watermarking mesh representations of 3-D graphical objects. A robust digital watermarking method has to mitigate among the requirements of watermark invisibility, robustness, embedding capacity and key security. The proposed method employs a mesh propagation distance metric procedure called the fast marching method (FMM), which defines regions of equal geodesic distance width calculated with respect to a reference location on the mesh. Each of these regions is used for embedding a single bit. The embedding is performed by changing the normalized distribution of local geodesic distances from within each region. Two different embedding methods are used by changing the mean or the variance of geodesic distance distributions. Geodesic distances are slightly modified statistically by displacing the vertices in their existing triangle planes. The vertex displacements, performed according to the FMM, ensure a minimal surface distortion while embedding the watermark code. Robustness to a variety of attacks is shown according to experimental results.

  19. In vivo bioluminescence tomography based on multi-view projection and 3D surface reconstruction

    NASA Astrophysics Data System (ADS)

    Zhang, Shuang; Wang, Kun; Leng, Chengcai; Deng, Kexin; Hu, Yifang; Tian, Jie

    2015-03-01

    Bioluminescence tomography (BLT) is a powerful optical molecular imaging modality, which enables non-invasive realtime in vivo imaging as well as 3D quantitative analysis in preclinical studies. In order to solve the inverse problem and reconstruct inner light sources accurately, the prior structural information is commonly necessary and obtained from computed tomography or magnetic resonance imaging. This strategy requires expensive hybrid imaging system, complicated operation protocol and possible involvement of ionizing radiation. The overall robustness highly depends on the fusion accuracy between the optical and structural information. In this study we present a pure optical bioluminescence tomographic system (POBTS) and a novel BLT method based on multi-view projection acquisition and 3D surface reconstruction. The POBTS acquired a sparse set of white light surface images and bioluminescent images of a mouse. Then the white light images were applied to an approximate surface model to generate a high quality textured 3D surface reconstruction of the mouse. After that we integrated multi-view luminescent images based on the previous reconstruction, and applied an algorithm to calibrate and quantify the surface luminescent flux in 3D.Finally, the internal bioluminescence source reconstruction was achieved with this prior information. A BALB/C mouse with breast tumor of 4T1-fLuc cells mouse model were used to evaluate the performance of the new system and technique. Compared with the conventional hybrid optical-CT approach using the same inverse reconstruction method, the reconstruction accuracy of this technique was improved. The distance error between the actual and reconstructed internal source was decreased by 0.184 mm.

  20. Air-structured optical fiber drawn from a 3D-printed preform.

    PubMed

    Cook, Kevin; Canning, John; Leon-Saval, Sergio; Reid, Zane; Hossain, Md Arafat; Comatti, Jade-Edouard; Luo, Yanhua; Peng, Gang-Ding

    2015-09-01

    A structured optical fiber is drawn from a 3D-printed structured preform. Preforms containing a single ring of holes around the core are fabricated using filament made from a modified butadiene polymer. More broadly, 3D printers capable of processing soft glasses, silica, and other materials are likely to come on line in the not-so-distant future. 3D printing of optical preforms signals a new milestone in optical fiber manufacture.

  1. Application issues when using optical 3D systems in place of CMMs

    NASA Astrophysics Data System (ADS)

    Harding, Kevin G.

    2002-02-01

    A primary application of optical 3D measurement systems has been in the replacement of mechanical coordinate measurement machines (CMMs). The advantage of optical 3D systems is typically greater speed and flexibility of operation over even the best CMMs. However, the two technologies are not necessarily one to one replacements, requiring new methods of use and in general proof of performance. This paper will present specific data that highlights the differences between CMMs and optical 3D systems and suggests a method to properly achieve CMM compatible results with an optical 3D system and the problems seen in this study.

  2. Minimizing camera-eye optical aberrations during the 3D reconstruction of retinal structures

    NASA Astrophysics Data System (ADS)

    Aldana-Iuit, Javier; Martinez-Perez, M. Elena; Espinosa-Romero, Arturo; Diaz-Uribe, Rufino

    2010-05-01

    3D reconstruction of blood vessels is a powerful visualization tool for physicians, since it allows them to refer to qualitative representation of their subject of study. In this paper we propose a 3D reconstruction method of retinal vessels from fundus images. The reconstruction method propose herein uses images of the same retinal structure in epipolar geometry. Images are preprocessed by RISA system for segmenting blood vessels and obtaining feature points for correspondences. The correspondence points process is solved using correlation. The LMedS analysis and Graph Transformation Matching algorithm are used for outliers suppression. Camera projection matrices are computed with the normalized eight point algorithm. Finally, we retrieve 3D position of the retinal tree points by linear triangulation. In order to increase the power of visualization, 3D tree skeletons are represented by surfaces via generalized cylinders whose radius correspond to morphological measurements obtained by RISA. In this paper the complete calibration process including the fundus camera and the optical properties of the eye, the so called camera-eye system is proposed. On one hand, the internal parameters of the fundus camera are obtained by classical algorithms using a reference pattern. On the other hand, we minimize the undesirable efects of the aberrations induced by the eyeball optical system assuming that contact enlarging lens corrects astigmatism, spherical and coma aberrations are reduced changing the aperture size and eye refractive errors are suppressed adjusting camera focus during image acquisition. Evaluation of two self-calibration proposals and results of 3D blood vessel surface reconstruction are presented.

  3. Design of 3D isotropic metamaterial device using smart transformation optics.

    PubMed

    Shin, Dongheok; Kim, Junhyun; Yoo, Do-Sik; Kim, Kyoungsik

    2015-08-24

    We report here a design method for a 3 dimensional (3D) isotropic transformation optical device using smart transformation optics. Inspired by solid mechanics, smart transformation optics regards a transformation optical medium as an elastic solid and deformations as coordinate transformations. Further developing from our previous work on 2D smart transformation optics, we introduce a method of 3D smart transformation optics to design 3D transformation optical devices by maintaining isotropic materials properties for all types of polarizations imposing free or nearly free boundary conditions. Due to the material isotropy, it is possible to fabricate such devices with structural metamaterials made purely of common dielectric materials. In conclusion, the practical importance of the method reported here lies in the fact that it enables us to fabricate, without difficulty, arbitrarily shaped 3D devices with existing 3D printing technology.

  4. Design of 3D isotropic metamaterial device using smart transformation optics.

    PubMed

    Shin, Dongheok; Kim, Junhyun; Yoo, Do-Sik; Kim, Kyoungsik

    2015-08-24

    We report here a design method for a 3 dimensional (3D) isotropic transformation optical device using smart transformation optics. Inspired by solid mechanics, smart transformation optics regards a transformation optical medium as an elastic solid and deformations as coordinate transformations. Further developing from our previous work on 2D smart transformation optics, we introduce a method of 3D smart transformation optics to design 3D transformation optical devices by maintaining isotropic materials properties for all types of polarizations imposing free or nearly free boundary conditions. Due to the material isotropy, it is possible to fabricate such devices with structural metamaterials made purely of common dielectric materials. In conclusion, the practical importance of the method reported here lies in the fact that it enables us to fabricate, without difficulty, arbitrarily shaped 3D devices with existing 3D printing technology. PMID:26368165

  5. Application of an optical 3D sensor for automated disassembling

    NASA Astrophysics Data System (ADS)

    Knackfuss, Peter; Schmidt, Achim

    1996-08-01

    The application of an active vision 3D sensor is described for the development and control of an autonomous intelligent robot cell for the disassembling of end-of-life-vehicle components. The research and development work was done concurrently by three European development teams at different locations. During this phase, the virtual environment was distributed on the local development platforms of these teams. Intermediate development results and 3D sensor data were exchanged through network communication to be mutually tested and verified. The physical environment of the disassembling cell demonstrator and its sensor systems is currently being integrated at the BIBA institute.

  6. Determination of 3D optic axis orientation in cartilage by polarization-sensitive optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Ugryumova, Nadya; Matcher, Stephen J.

    2007-02-01

    Polarization-sensitive optical coherence tomography has been used to solve fast-axis fibre orientation in three dimension space. Previously we have demonstrated that the apparent variations in polar angle orientation of collagen fibers along sagittal ridge of equine third metacarpophalangeal joint exist. A quantitative method based on multiple angles of illumination has been proposed to determine the polar angle of the collagen fibers. This method however ignored the full 3-D structure by assuming that the collagen fibers long-axis lay within the plane of incidence. A new quantitative method based on the theory of light propagation in uniaxial materials is described which avoids this assumption. To test this method we have performed control experiments on a sample of equine tendon (this tissue has well defined c-axis lying along the long-axis of the tendon). Several samples of tendon were cut to achieve a planar surface inclined at -20° to the long axis. Additional 30° rotation provided non-zero azimuthal angle. The surface was then imaged using incident beam angles -40°, -20°, 0, +20°, +40° in two orthogonal planes. Values for both the polar and azimuthal angles were then derived using a numerical optimisation procedure. Results agreed qualitatively with the nominal values but suggested that the accuracy was limited by our method of determining the apparent birefringence.

  7. Determination of 3D optic axis orientation in cartilage by polarization-sensitive optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Ugryumova, Nadya; Bonesi, Marco; Matcher, Stephen J.

    2008-02-01

    Polarization-sensitive optical coherence tomography has been used to solve fast-axis fibre orientation in three dimension space. Previously we have demonstrated that the apparent variations in polar angle orientation of collagen fibers along sagittal ridge of equine third metacarpophalangeal joint exist. A quantitative method based on multiple angles of illumination has been proposed to determine the polar angle of the collagen fibers. This method however ignored the full 3D structure by assuming that the collagen fibers long-axis lay within the plane of incidence. A new quantitative method based on the theory of light propagation in uniaxial materials is described which avoids this assumption. To test this method we have performed control experiments on a sample of equine tendon (this tissue has well defined c-axis lying along the long-axis of the tendon). Several samples of tendon were cut to achieve a planar surface inclined at -20° to the long axis. Additional 30° rotation provided non-zero azimuthal angle. The surface was then imaged using incident beam angles -40°, -20°, 0, +20°, +40° in two orthogonal planes. Values for both the polar and azimuthal angles were then derived using a numerical optimisation procedure. Results agreed qualitatively with the nominal values but suggested that the accuracy was limited by our method of determining the apparent birefringence.

  8. 3D Printing of Molecular Potential Energy Surface Models

    ERIC Educational Resources Information Center

    Lolur, Phalgun; Dawes, Richard

    2014-01-01

    Additive manufacturing, commonly known as 3D printing, is gaining popularity in a variety of applications and has recently become routinely available. Today, 3D printing services are not only found in engineering design labs and through online companies, but also in university libraries offering student access. In addition, affordable options for…

  9. Surface modified alginate microcapsules for 3D cell culture

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Wen; Kuo, Chiung Wen; Chueh, Di-Yen; Chen, Peilin

    2016-06-01

    Culture as three dimensional cell aggregates or spheroids can offer an ideal platform for tissue engineering applications and for pharmaceutical screening. Such 3D culture models, however, may suffer from the problems such as immune response and ineffective and cumbersome culture. This paper describes a simple method for producing microcapsules with alginate cores and a thin shell of poly(L-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) to encapsulate mouse induced pluripotent stem (miPS) cells, generating a non-fouling surface as an effective immunoisolation barrier. We demonstrated the trapping of the alginate microcapsules in a microwell array for the continuous observation and culture of a large number of encapsulated miPS cells in parallel. miPS cells cultured in the microcapsules survived well and proliferated to form a single cell aggregate. Droplet formation of monodisperse microcapsules with controlled size combined with flow cytometry provided an efficient way to quantitatively analyze the growth of encapsulated cells in a high-throughput manner. The simple and cost-effective coating technique employed to produce the core-shell microcapsules could be used in the emerging field of cell therapy. The microwell array would provide a convenient, user friendly and high-throughput platform for long-term cell culture and monitoring.

  10. Computational-optical microscopy for 3D biological imaging beyond the diffraction limit

    NASA Astrophysics Data System (ADS)

    Grover, Ginni

    In recent years, super-resolution imaging has become an important fluorescent microscopy tool. It has enabled imaging of structures smaller than the optical diffraction limit with resolution less than 50 nm. Extension to high-resolution volume imaging has been achieved by integration with various optical techniques. In this thesis, development of a fluorescent microscope to enable high resolution, extended depth, three dimensional (3D) imaging is discussed; which is achieved by integration of computational methods with optical systems. In the first part of the thesis, point spread function (PSF) engineering for volume imaging is discussed. A class of PSFs, referred to as double-helix (DH) PSFs, is generated. The PSFs exhibit two focused spots in the image plane which rotate about the optical axis, encoding depth in rotation of the image. These PSFs extend the depth-of-field up to a factor of ˜5. Precision performance of the DH-PSFs, based on an information theoretical analysis, is compared with other 3D methods with conclusion that the DH-PSFs provide the best precision and the longest depth-of-field. Out of various possible DH-PSFs, a suitable PSF is obtained for super-resolution microscopy. The DH-PSFs are implemented in imaging systems, such as a microscope, with a special phase modulation at the pupil plane. Surface-relief elements which are polarization-insensitive and ˜90% light efficient are developed for phase modulation. The photon-efficient DH-PSF microscopes thus developed are used, along with optimal position estimation algorithms, for tracking and super-resolution imaging in 3D. Imaging at depths-of-field of up to 2.5 microm is achieved without focus scanning. Microtubules were imaged with 3D resolution of (6, 9, 39) nm, which is in close agreement with the theoretical limit. A quantitative study of co-localization of two proteins in volume was conducted in live bacteria. In the last part of the thesis practical aspects of the DH-PSF microscope are

  11. Potential of ILRIS3D Intensity Data for Planar Surfaces Segmentation.

    PubMed

    Wang, Chi-Kuei; Lu, Yao-Yu

    2009-01-01

    Intensity value based point cloud segmentation has received less attention because the intensity value of the terrestrial laser scanner is usually altered by receiving optics/hardware or the internal propriety software, which is unavailable to the end user. We offer a solution by assuming the terrestrial laser scanners are stable and the behavior of the intensity value can be characterized. Then, it is possible to use the intensity value for segmentation by observing its behavior, i.e., intensity value variation, pattern and presence of location of intensity values, etc. In this study, experiment results for characterizing the intensity data of planar surfaces collected by ILRIS3D, a terrestrial laser scanner, are reported. Two intensity formats, grey and raw, are employed by ILRIS3D. It is found from the experiment results that the grey intensity has less variation; hence it is preferable for point cloud segmentation. A warm-up time of approximate 1.5 hours is suggested for more stable intensity data. A segmentation method based on the visual cues of the intensity images sequence, which contains consecutive intensity images, is proposed in order to segment the 3D laser points of ILRIS3D. This method is unique to ILRIS3D data and does not require radiometric calibration. PMID:22346726

  12. Optical turbulence above mountains seen in 3D

    NASA Astrophysics Data System (ADS)

    Els, S. G.; Vogiatzis, K.; Otárola, A.; Riddle, R.; Schöck, M.; Skidmore, W.; Travouillon, T.

    2010-07-01

    Atmospheric optical turbulence is the main driver of wavefront distortions which affect optical telescope performance. Therefore, many techniques have been developed to measure the optical turbulence strength along the line of sight. Based on data collected with the MASS (Multi Aperture Scintillation Sensor), we show that a large sample of such measurements can be used to assess the average three dimensional turbulence distribution above ground. The use of, and a more sophisticated instrumental setup for, such turbulence tomography will be discussed.

  13. 3D optical printing of piezoelectric nanoparticle-polymer composite materials.

    PubMed

    Kim, Kanguk; Zhu, Wei; Qu, Xin; Aaronson, Chase; McCall, William R; Chen, Shaochen; Sirbuly, Donald J

    2014-10-28

    Here we demonstrate that efficient piezoelectric nanoparticle-polymer composite materials can be optically printed into three-dimensional (3D) microstructures using digital projection printing. Piezoelectric polymers were fabricated by incorporating barium titanate (BaTiO3, BTO) nanoparticles into photoliable polymer solutions such as polyethylene glycol diacrylate and exposing to digital optical masks that could be dynamically altered to generate user-defined 3D microstructures. To enhance the mechanical-to-electrical conversion efficiency of the composites, the BTO nanoparticles were chemically modified with acrylate surface groups, which formed direct covalent linkages with the polymer matrix under light exposure. The composites with a 10% mass loading of the chemically modified BTO nanoparticles showed piezoelectric coefficients (d(33)) of ∼ 40 pC/N, which were over 10 times larger than composites synthesized with unmodified BTO nanoparticles and over 2 times larger than composites containing unmodified BTO nanoparticles and carbon nanotubes to boost mechanical stress transfer efficiencies. These results not only provide a tool for fabricating 3D piezoelectric polymers but lay the groundwork for creating highly efficient piezoelectric polymer materials via nanointerfacial tuning.

  14. Parallel Imaging of 3D Surface Profile with Space-Division Multiplexing.

    PubMed

    Lee, Hyung Seok; Cho, Soon-Woo; Kim, Gyeong Hun; Jeong, Myung Yung; Won, Young Jae; Kim, Chang-Seok

    2016-01-01

    We have developed a modified optical frequency domain imaging (OFDI) system that performs parallel imaging of three-dimensional (3D) surface profiles by using the space division multiplexing (SDM) method with dual-area swept sourced beams. We have also demonstrated that 3D surface information for two different areas could be well obtained in a same time with only one camera by our method. In this study, double field of views (FOVs) of 11.16 mm × 5.92 mm were achieved within 0.5 s. Height range for each FOV was 460 µm and axial and transverse resolutions were 3.6 and 5.52 µm, respectively.

  15. Focusing optics of a parallel beam CCD optical tomography apparatus for 3D radiation gel dosimetry.

    PubMed

    Krstajić, Nikola; Doran, Simon J

    2006-04-21

    Optical tomography of gel dosimeters is a promising and cost-effective avenue for quality control of radiotherapy treatments such as intensity-modulated radiotherapy (IMRT). Systems based on a laser coupled to a photodiode have so far shown the best results within the context of optical scanning of radiosensitive gels, but are very slow ( approximately 9 min per slice) and poorly suited to measurements that require many slices. Here, we describe a fast, three-dimensional (3D) optical computed tomography (optical-CT) apparatus, based on a broad, collimated beam, obtained from a high power LED and detected by a charged coupled detector (CCD). The main advantages of such a system are (i) an acquisition speed approximately two orders of magnitude higher than a laser-based system when 3D data are required, and (ii) a greater simplicity of design. This paper advances our previous work by introducing a new design of focusing optics, which take information from a suitably positioned focal plane and project an image onto the CCD. An analysis of the ray optics is presented, which explains the roles of telecentricity, focusing, acceptance angle and depth-of-field (DOF) in the formation of projections. A discussion of the approximation involved in measuring the line integrals required for filtered backprojection reconstruction is given. Experimental results demonstrate (i) the effect on projections of changing the position of the focal plane of the apparatus, (ii) how to measure the acceptance angle of the optics, and (iii) the ability of the new scanner to image both absorbing and scattering gel phantoms. The quality of reconstructed images is very promising and suggests that the new apparatus may be useful in a clinical setting for fast and accurate 3D dosimetry. PMID:16585845

  16. Focusing optics of a parallel beam CCD optical tomography apparatus for 3D radiation gel dosimetry

    NASA Astrophysics Data System (ADS)

    Krstajic, Nikola; Doran, Simon J.

    2006-04-01

    Optical tomography of gel dosimeters is a promising and cost-effective avenue for quality control of radiotherapy treatments such as intensity-modulated radiotherapy (IMRT). Systems based on a laser coupled to a photodiode have so far shown the best results within the context of optical scanning of radiosensitive gels, but are very slow (~9 min per slice) and poorly suited to measurements that require many slices. Here, we describe a fast, three-dimensional (3D) optical computed tomography (optical-CT) apparatus, based on a broad, collimated beam, obtained from a high power LED and detected by a charged coupled detector (CCD). The main advantages of such a system are (i) an acquisition speed approximately two orders of magnitude higher than a laser-based system when 3D data are required, and (ii) a greater simplicity of design. This paper advances our previous work by introducing a new design of focusing optics, which take information from a suitably positioned focal plane and project an image onto the CCD. An analysis of the ray optics is presented, which explains the roles of telecentricity, focusing, acceptance angle and depth-of-field (DOF) in the formation of projections. A discussion of the approximation involved in measuring the line integrals required for filtered backprojection reconstruction is given. Experimental results demonstrate (i) the effect on projections of changing the position of the focal plane of the apparatus, (ii) how to measure the acceptance angle of the optics, and (iii) the ability of the new scanner to image both absorbing and scattering gel phantoms. The quality of reconstructed images is very promising and suggests that the new apparatus may be useful in a clinical setting for fast and accurate 3D dosimetry.

  17. Coupling 3D Monte Carlo light transport in optically heterogeneous tissues to photoacoustic signal generation

    PubMed Central

    Jacques, Steven L.

    2014-01-01

    The generation of photoacoustic signals for imaging objects embedded within tissues is dependent on how well light can penetrate to and deposit energy within an optically absorbing object, such as a blood vessel. This report couples a 3D Monte Carlo simulation of light transport to stress wave generation to predict the acoustic signals received by a detector at the tissue surface. The Monte Carlo simulation allows modeling of optically heterogeneous tissues, and a simple MATLAB™ acoustic algorithm predicts signals reaching a surface detector. An example simulation considers a skin with a pigmented epidermis, a dermis with a background blood perfusion, and a 500-μm-dia. blood vessel centered at a 1-mm depth in the skin. The simulation yields acoustic signals received by a surface detector, which are generated by a pulsed 532-nm laser exposure before and after inserting the blood vessel. A MATLAB™ version of the acoustic algorithm and a link to the 3D Monte Carlo website are provided. PMID:25426426

  18. Coupling 3D Monte Carlo light transport in optically heterogeneous tissues to photoacoustic signal generation.

    PubMed

    Jacques, Steven L

    2014-12-01

    The generation of photoacoustic signals for imaging objects embedded within tissues is dependent on how well light can penetrate to and deposit energy within an optically absorbing object, such as a blood vessel. This report couples a 3D Monte Carlo simulation of light transport to stress wave generation to predict the acoustic signals received by a detector at the tissue surface. The Monte Carlo simulation allows modeling of optically heterogeneous tissues, and a simple MATLAB™ acoustic algorithm predicts signals reaching a surface detector. An example simulation considers a skin with a pigmented epidermis, a dermis with a background blood perfusion, and a 500-μm-dia. blood vessel centered at a 1-mm depth in the skin. The simulation yields acoustic signals received by a surface detector, which are generated by a pulsed 532-nm laser exposure before and after inserting the blood vessel. A MATLAB™ version of the acoustic algorithm and a link to the 3D Monte Carlo website are provided.

  19. Brightness-compensated 3-D optical flow algorithm for monitoring cochlear motion patterns

    NASA Astrophysics Data System (ADS)

    von Tiedemann, Miriam; Fridberger, Anders; Ulfendahl, Mats; de Monvel, Jacques Boutet

    2010-09-01

    A method for three-dimensional motion analysis designed for live cell imaging by fluorescence confocal microscopy is described. The approach is based on optical flow computation and takes into account brightness variations in the image scene that are not due to motion, such as photobleaching or fluorescence variations that may reflect changes in cellular physiology. The 3-D optical flow algorithm allowed almost perfect motion estimation on noise-free artificial sequences, and performed with a relative error of <10% on noisy images typical of real experiments. The method was applied to a series of 3-D confocal image stacks from an in vitro preparation of the guinea pig cochlea. The complex motions caused by slow pressure changes in the cochlear compartments were quantified. At the surface of the hearing organ, the largest motion component was the transverse one (normal to the surface), but significant radial and longitudinal displacements were also present. The outer hair cell displayed larger radial motion at their basolateral membrane than at their apical surface. These movements reflect mechanical interactions between different cellular structures, which may be important for communicating sound-evoked vibrations to the sensory cells. A better understanding of these interactions is important for testing realistic models of cochlear mechanics.

  20. Combining supine MRI and 3D optical scanning for improved surgical planning of breast conserving surgeries

    NASA Astrophysics Data System (ADS)

    Pallone, Matthew J.; Poplack, Steven P.; Barth, Richard J., Jr.; Paulsen, Keith D.

    2012-02-01

    Image-guided wire localization is the current standard of care for the excision of non-palpable carcinomas during breast conserving surgeries (BCS). The efficacy of this technique depends upon the accuracy of wire placement, maintenance of the fixed wire position (despite patient movement), and the surgeon's understanding of the spatial relationship between the wire and tumor. Notably, breast shape can vary significantly between the imaging and surgical positions. Despite this method of localization, re-excision is needed in approximately 30% of patients due to the proximity of cancer to the specimen margins. These limitations make wire localization an inefficient and imprecise procedure. Alternatively, we investigate a method of image registration and finite element (FE) deformation which correlates preoperative supine MRIs with 3D optical scans of the breast surface. MRI of the breast can accurately define the extents of very small cancers. Furthermore, supine breast MR reduces the amount of tissue deformation between the imaging and surgical positions. At the time of surgery, the surface contour of the breast may be imaged using a handheld 3D laser scanner. With the MR images segmented by tissue type, the two scans are approximately registered using fiducial markers present in both acquisitions. The segmented MRI breast volume is then deformed to match the optical surface using a FE mechanical model of breast tissue. The resulting images provide the surgeon with 3D views and measurements of the tumor shape, volume, and position within the breast as it appears during surgery which may improve surgical guidance and obviate the need for wire localization.

  1. 3-D Adaptive Sparsity Based Image Compression with Applications to Optical Coherence Tomography

    PubMed Central

    Fang, Leyuan; Li, Shutao; Kang, Xudong; Izatt, Joseph A.; Farsiu, Sina

    2015-01-01

    We present a novel general-purpose compression method for tomographic images, termed 3D adaptive sparse representation based compression (3D-ASRC). In this paper, we focus on applications of 3D-ASRC for the compression of ophthalmic 3D optical coherence tomography (OCT) images. The 3D-ASRC algorithm exploits correlations among adjacent OCT images to improve compression performance, yet is sensitive to preserving their differences. Due to the inherent denoising mechanism of the sparsity based 3D-ASRC, the quality of the compressed images are often better than the raw images they are based on. Experiments on clinical-grade retinal OCT images demonstrate the superiority of the proposed 3D-ASRC over other well-known compression methods. PMID:25561591

  2. Light sheet adaptive optics microscope for 3D live imaging

    NASA Astrophysics Data System (ADS)

    Bourgenot, C.; Taylor, J. M.; Saunter, C. D.; Girkin, J. M.; Love, G. D.

    2013-02-01

    We report on the incorporation of adaptive optics (AO) into the imaging arm of a selective plane illumination microscope (SPIM). SPIM has recently emerged as an important tool for life science research due to its ability to deliver high-speed, optically sectioned, time-lapse microscope images from deep within in vivo selected samples. SPIM provides a very interesting system for the incorporation of AO as the illumination and imaging paths are decoupled and AO may be useful in both paths. In this paper, we will report the use of AO applied to the imaging path of a SPIM, demonstrating significant improvement in image quality of a live GFP-labeled transgenic zebrafish embryo heart using a modal, wavefront sensorless approach and a heart synchronization method. These experimental results are linked to a computational model showing that significant aberrations are produced by the tube holding the sample in addition to the aberration from the biological sample itself.

  3. Towards a 3-D Magneto-Optical Trap for Molecules

    NASA Astrophysics Data System (ADS)

    Collopy, Alejandra; Hummon, Matthew; Yeo, Mark; Stuhl, Benjamin; Hemmerling, Boerge; Drayna, Garrett; Chae, Eunmi; Ravi, Aakash; Lu, Hsin-I.; Doyle, John; Ye, Jun

    2013-05-01

    As the magneto-optical trap revolutionized atomic physics, we anticipate the molecular counterpart to open doors to unexplored molecular physics, including ultra-cold chemistry. While molecules possess more complex structure than atoms, quasi-cycling cooling transitions are still attainable in a variety of species, including the polar molecule YO. In order to remix dark states, we RF modulate the polarization of the light in our trap. In order to maintain a restoring force, we modulate the orientation of our magnetic fields in phase with the light using LC resonant in-vacuum magnetic coils. We demonstrate magneto-optical trapping in two dimensions for YO, and present progress towards a three dimensional implementation of a MOT loaded from a two-stage buffer gas cell source. We acknowledge support from the AFOSR (MURI), DOE, NIST and the NSF.

  4. A fast method to measure the 3D surface of the human heart

    NASA Astrophysics Data System (ADS)

    Cao, Yiping; Su, Xianyu; Xiang, Liqun; Chen, Wenjing; Zhang, Qican

    2003-12-01

    Three-dimensional (3-D) automatic measurement of an object is widely used in many fields. In Biology and Medicine society, it can be applicable for surgery, orthopedics, viscera disease analysis and diagnosis etc. Here a new fast method to measure the 3D surface of human heart is proposed which can provide doctors a lot of information, such as the size of heart profile, the sizes of the left or right heart ventricle, and the curvature center and radius of heart ventricle, to fully analyze and diagnose pathobiology of human heart. The new fast method is optically and noncontacted and based upon the Phase Measurement Profilometry (PMP), which has higher measuring precision. A human heart specimen experiment has verified our method.

  5. State of the art of 3D scanning systems and inspection of textile surfaces

    NASA Astrophysics Data System (ADS)

    Montilla, M.; Orjuela-Vargas, S. A.; Philips, W.

    2014-02-01

    The rapid development of hardware and software in the digital image processing field has boosted research in computer vision for applications in industry. The development of new electronic devices and the tendency to decrease their prices makes possible new developments that few decades ago were possible only in the imagination. This is the case of 3D imaging technology which permits to detect failures in industrial products by inspecting aspects on their 3D surface. In search of an optimal solution for scanning textiles we present in this paper a review of existing techniques for digitizing 3D surfaces. Topographic details of textiles can be obtained by digitizing surfaces using laser line triangulation, phase shifting optical triangulation, projected-light, stereo-vision systems and silhouette analysis. Although we are focused on methods that have been used in the textile industry, we also consider potential mechanisms used for other applications. We discuss the advantages and disadvantages of the evaluated methods and state a summary of potential implementations for the textile industry.

  6. Damage and deterioration monitoring of artwork by data fusion of 3D surface and hyperspectral measurements

    NASA Astrophysics Data System (ADS)

    Groves, Roger M.; Caballero, José; Quinzan, Ianisse; Ribes-Gómez, Emilio

    2014-05-01

    This paper describes the processing algorithm methodology and preliminary results from a novel optical-based system for the assessment of chemical and mechanical deterioration of artworks. The FP7 Syddarta Project prototype is composed of two optical channels: 1) a 3D imaging channel which acquires 3D surface data and multiband information in the visible spectral range; 2) an infrared hyperspectral imaging channel in the spectral range 900 to 2500 nm. The processing algorithms developed perform the system calibration, damage detection and chemical deterioration analysis. Both photometric and geometric calibrations have been implemented. The photometric calibration is based on a white reference and intensity map and compensates for variation in light intensities. The geometric calibration is based on planar homographies to determine the interior and exterior orientation of the projector and the two cameras. This is used to map the acquired data of the different sensors into a single reference frame. To acquire 3D data, a set of phase-shifted fringe patterns is projected on the object which are processed by Fourier transform. To identify mechanical deterioration, the acquired 3D cloud of points is meshed and differences in surface normals for a given radius are computed. To analyse the chemical deterioration of the pigments a supervised classification method has been implemented. First of all, spectral data is normalized with the Extended Multiplicative Scatter Correction algorithm. Then, data dimensionality is reduced by applying Principal Component Analysis and classification is done with Support Vector Machine. Results are presented showing the performance of the described algorithms.

  7. 3D parameter reconstruction in hyperspectral diffuse optical tomography

    NASA Astrophysics Data System (ADS)

    Saibaba, Arvind K.; Krishnamurthy, Nishanth; Anderson, Pamela G.; Kainerstorfer, Jana M.; Sassaroli, Angelo; Miller, Eric L.; Fantini, Sergio; Kilmer, Misha E.

    2015-03-01

    The imaging of shape perturbation and chromophore concentration using Diffuse Optical Tomography (DOT) data can be mathematically described as an ill-posed and non-linear inverse problem. The reconstruction algorithm for hyperspectral data using a linearized Born model is prohibitively expensive, both in terms of computation and memory. We model the shape of the perturbation using parametric level-set approach (PaLS). We discuss novel computational strategies for reducing the computational cost based on a Krylov subspace approach for parameteric linear systems and a compression strategy for the parameter-to-observation map. We will demonstrate the validity of our approach by comparison with experiments.

  8. Gloss optical elementary representative surface.

    PubMed

    Vernhes, Pierre; Bloch, Jean-Francis; Blayo, Anne; Pineaux, Bernard

    2008-10-10

    Roughness measurements are of main importance in characterizing the optical properties of papers and prints. However, there is a lack of knowledge concerning the surface size and the spacing of the measures to be optically representative of the surface structure. Paper is a multiscale medium, and the roughness parameters extracted from the three-dimensional (3D) surface mapping depend on both the size and the step of discretization. Ray tracing, based on optical geometry, could be a tool to model the light reflection on a paper surface. Ray-tracer software was therefore developed. A new optical device was used to measure paper surface topographies at various scales. Ray tracing simulations were then performed on the 3D mapping and compared to the scattering indicatrix obtained with a classical goniometer. Hence it was possible to identify a magnification for various types of paper grades that is optically representative of the specular gloss.

  9. Snapshot 3D optical coherence tomography system using image mappingspectrometry

    PubMed Central

    Nguyen, Thuc-Uyen; Pierce, Mark C; Higgins, Laura; Tkaczyk, Tomasz S

    2013-01-01

    A snapshot 3-Dimensional Optical Coherence Tomography system was developed using Image MappingSpectrometry. This system can give depth information (Z) at different spatial positions (XY) withinone camera integration time to potentially reduce motion artifact and enhance throughput. Thecurrent (x,y,λ) datacube of (85×356×117) provides a 3Dvisualization of sample with 400 μm depth and 13.4μm in transverse resolution. Axial resolution of 16.0μm can also be achieved in this proof-of-concept system. We present ananalysis of the theoretical constraints which will guide development of future systems withincreased imaging depth and improved axial and lateral resolutions. PMID:23736629

  10. Controllable 3D atomic Brownian motor in optical lattices

    NASA Astrophysics Data System (ADS)

    Dion, C. M.; Sjölund, P.; Petra, S. J. H.; Jonsell, S.; Nylén, M.; Sanchez-Palencia, L.; Kastberg, A.

    2008-06-01

    We study a Brownian motor, based on cold atoms in optical lattices, where atomic motion can be induced in a controlled manner in an arbitrary direction, by rectification of isotropic random fluctuations. In contrast with ratchet mechanisms, our Brownian motor operates in a potential that is spatially and temporally symmetric, in apparent contradiction to the Curie principle. Simulations, based on the Fokker-Planck equation, allow us to gain knowledge on the qualitative behaviour of our Brownian motor. Studies of Brownian motors, and in particular ones with unique control properties, are of fundamental interest because of the role they play in protein motors and their potential applications in nanotechnology. In particular, our system opens the way to the study of quantum Brownian motors.

  11. 3D Printing Optical Engine for Controlling Material Microstructure

    NASA Astrophysics Data System (ADS)

    Huang, Wei-Chin; Chang, Kuang-Po; Wu, Ping-Han; Wu, Chih-Hsien; Lin, Ching-Chih; Chuang, Chuan-Sheng; Lin, De-Yau; Liu, Sung-Ho; Horng, Ji-Bin; Tsau, Fang-Hei

    Controlling the cooling rate of alloy during melting and resolidification is the most commonly used method for varying the material microstructure and consequently the resuling property. However, the cooling rate of a selective laser melting (SLM) production is restricted by a preset optimal parameter of a good dense product. The head room for locally manipulating material property in a process is marginal. In this study, we invent an Optical Engine for locally controlling material microstructure in a SLM process. It develops an invovative method to control and adjust thermal history of the solidification process to gain desired material microstucture and consequently drastically improving the quality. Process parameters selected locally for specific materials requirement according to designed characteristics by using thermal dynamic principles of solidification process. It utilize a technique of complex laser beam shape of adaptive irradiation profile to permit local control of material characteristics as desired. This technology could be useful for industrial application of medical implant, aerospace and automobile industries.

  12. An optical real-time 3D measurement for analysis of facial shape and movement

    NASA Astrophysics Data System (ADS)

    Zhang, Qican; Su, Xianyu; Chen, Wenjing; Cao, Yiping; Xiang, Liqun

    2003-12-01

    Optical non-contact 3-D shape measurement provides a novel and useful tool for analysis of facial shape and movement in presurgical and postsurgical regular check. In this article we present a system, which allows a precise 3-D visualization of the patient's facial before and after craniofacial surgery. We discussed, in this paper, the real time 3-D image capture, processing and the 3-D phase unwrapping method to recover complex shape deformation when the movement of the mouth. The result of real-time measurement for facial shape and movement will be helpful for the more ideal effect in plastic surgery.

  13. Full optical characterization of autostereoscopic 3D displays using local viewing angle and imaging measurements

    NASA Astrophysics Data System (ADS)

    Boher, Pierre; Leroux, Thierry; Bignon, Thibault; Collomb-Patton, Véronique

    2012-03-01

    Two commercial auto-stereoscopic 3D displays are characterized a using Fourier optics viewing angle system and an imaging video-luminance-meter. One display has a fixed emissive configuration and the other adapts its emission to the observer position using head tracking. For a fixed emissive condition, three viewing angle measurements are performed at three positions (center, right and left). Qualified monocular and binocular viewing spaces in front of the display are deduced as well as the best working distance. The imaging system is then positioned at this working distance and crosstalk homogeneity on the entire surface of the display is measured. We show that the crosstalk is generally not optimized on all the surface of the display. Display aspect simulation using viewing angle measurements allows understanding better the origin of those crosstalk variations. Local imperfections like scratches and marks generally increase drastically the crosstalk, demonstrating that cleanliness requirements for this type of display are quite critical.

  14. Underwater 3D Surface Measurement Using Fringe Projection Based Scanning Devices

    PubMed Central

    Bräuer-Burchardt, Christian; Heinze, Matthias; Schmidt, Ingo; Kühmstedt, Peter; Notni, Gunther

    2015-01-01

    In this work we show the principle of optical 3D surface measurements based on the fringe projection technique for underwater applications. The challenges of underwater use of this technique are shown and discussed in comparison with the classical application. We describe an extended camera model which takes refraction effects into account as well as a proposal of an effective, low-effort calibration procedure for underwater optical stereo scanners. This calibration technique combines a classical air calibration based on the pinhole model with ray-based modeling and requires only a few underwater recordings of an object of known length and a planar surface. We demonstrate a new underwater 3D scanning device based on the fringe projection technique. It has a weight of about 10 kg and the maximal water depth for application of the scanner is 40 m. It covers an underwater measurement volume of 250 mm × 200 mm × 120 mm. The surface of the measurement objects is captured with a lateral resolution of 150 μm in a third of a second. Calibration evaluation results are presented and examples of first underwater measurements are given. PMID:26703624

  15. Underwater 3D Surface Measurement Using Fringe Projection Based Scanning Devices.

    PubMed

    Bräuer-Burchardt, Christian; Heinze, Matthias; Schmidt, Ingo; Kühmstedt, Peter; Notni, Gunther

    2015-12-23

    In this work we show the principle of optical 3D surface measurements based on the fringe projection technique for underwater applications. The challenges of underwater use of this technique are shown and discussed in comparison with the classical application. We describe an extended camera model which takes refraction effects into account as well as a proposal of an effective, low-effort calibration procedure for underwater optical stereo scanners. This calibration technique combines a classical air calibration based on the pinhole model with ray-based modeling and requires only a few underwater recordings of an object of known length and a planar surface. We demonstrate a new underwater 3D scanning device based on the fringe projection technique. It has a weight of about 10 kg and the maximal water depth for application of the scanner is 40 m. It covers an underwater measurement volume of 250 mm × 200 mm × 120 mm. The surface of the measurement objects is captured with a lateral resolution of 150 μm in a third of a second. Calibration evaluation results are presented and examples of first underwater measurements are given.

  16. Kinetic depth effect and optic flow--I. 3D shape from Fourier motion.

    PubMed

    Dosher, B A; Landy, M S; Sperling, G

    1989-01-01

    Fifty-three different 3D shapes were defined by sequences of 2D views (frames) of dots on a rotating 3D surface. (1) Subjects' accuracy of shape identifications dropped from over 90% to less than 10% when either the polarity of the stimulus dots was alternated from light-on-gray to dark-on-gray on successive frames or when neutral gray interframe intervals were interposed. Both manipulations interfere with motion extraction by spatio-temporal (Fourier) and gradient first-order detectors. Second-order (non-Fourier) detectors that use full-wave rectification are unaffected by alternating-polarity but disrupted by interposed gray frames. (2) To equate the accuracy of two-alternative forced-choice (2AFC) planar direction-of-motion discrimination in standard and polarity-alternated stimuli, standard contrast was reduced. 3D shape discrimination survived contrast reduction in standard stimuli whereas it failed completely with polarity-alternation even at full contrast. (3) When individual dots were permitted to remain in the image sequence for only two frames, performance showed little loss compared to standard displays where individual dots had an expected lifetime of 20 frames, showing that 3D shape identification does not require continuity of stimulus tokens. (4) Performance in all discrimination tasks is predicted (up to a monotone transformation) by considering the quality of first-order information (as given by a simple computation on Fourier power) and the number of locations at which motion information is required. Perceptual first-order analysis of optic flow is the primary substrate for structure-from-motion computations in random dot displays because only it offers sufficient quality of perceptual motion at a sufficient number of locations.

  17. Surface strain-field determination of tympanic membrane using 3D-digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Hernandez-Montes, María del S.; Mendoza Santoyo, Fernando; Muñoz, Silvino; Perez, Carlos; de la Torre, Manuel; Flores, Mauricio; Alvarez, Luis

    2015-08-01

    In order to increase the understanding of soft tissues mechanical properties, 3D Digital Holographic Interferometry (3D-DHI) was used to quantify the strain-field on a cat tympanic membrane (TM) surface. The experiments were carried out applying a constant sound-stimuli pressure of 90 dB SPL (0.632 Pa) on the TM at 1.2 kHz. The technique allows the accurate acquisition of the micro-displacement data along the x, y and z directions, which is a must for a full characterization of the tissue mechanical behavior under load, and for the calculation of the strain-field in situ. The displacements repeatability in z direction shows a standard deviation of 0.062 μm at 95% confidence level. In order to realize the full 3D characterization correctly the contour of the TM surface was measured employing the optically non-contact two-illumination positions contouring method. The x, y and z displacements combined with the TM contour data allow the evaluation its strain-field by spatially differentiating the u(m,n), v(m,n), and w(m,n) deformation components. The accurate and correct determination of the TM strain-field leads to describing its elasticity, which is an important parameter needed to improve ear biomechanics studies, audition processes and TM mobility in both experimental measurements and theoretical analysis of ear functionality and its modeling.

  18. Design of a large area 3D surface structure measurement system

    NASA Astrophysics Data System (ADS)

    Wang, Shenghuai; Li, Xin; Chen, Yurong; Xie, Tiebang

    2010-10-01

    Surface texture plays a vital role in modern engineering products. Currently surface metrology discipline is undergoing a paradigm shift from 2D profile to 3D areal and from stochastic to structured surface characterization. Areal surface texture measurements have greater fully functional significance parameters, better repeatability and more effectively visual express than profile measurements. The existing white light microscopy interference measurement can be used for the non-contact measurement of areal surface texture. However, the measurement field and lateral resolution of this method is restricted to the numerical aperture of objective. To address this issue, a type of vertical scanning white light interference stitching measurement system with large area and seamless has been built up in this paper. This system is based on the compound optical microscopy system and 3D precision displacement system with large travel, nanometer level and displacement measurement. The CCD calibration and angles calculation between CCD and level worktables are settled depending on the measurement system itself. A non-orthogonal worktable moving strategy is used for the seamless stitching measurement of this measurement method, which reduces the cost of stitching and enlarges the measurement field. Therefore the problem, which the lateral resolution and the measurement filed are restricted to the numerical aperture of objective, is solved. An automatic search and location method of fringe for white light interference measurement based on the normalized standard deviation of gray value of interference microscopy images is proposed to solve the problem of inefficiency for the search of interference fringe by hand.

  19. Fast 3D Surface Extraction 2 pages (including abstract)

    SciTech Connect

    Sewell, Christopher Meyer; Patchett, John M.; Ahrens, James P.

    2012-06-05

    Ocean scientists searching for isosurfaces and/or thresholds of interest in high resolution 3D datasets required a tedious and time-consuming interactive exploration experience. PISTON research and development activities are enabling ocean scientists to rapidly and interactively explore isosurfaces and thresholds in their large data sets using a simple slider with real time calculation and visualization of these features. Ocean Scientists can now visualize more features in less time, helping them gain a better understanding of the high resolution data sets they work with on a daily basis. Isosurface timings (512{sup 3} grid): VTK 7.7 s, Parallel VTK (48-core) 1.3 s, PISTON OpenMP (48-core) 0.2 s, PISTON CUDA (Quadro 6000) 0.1 s.

  20. Use of laser 3D surface digitizer in data collection and 3D modeling of anatomical structures

    NASA Astrophysics Data System (ADS)

    Tse, Kelly; Van Der Wall, Hans; Vu, Dzung H.

    2006-02-01

    A laser digitizer (Konica-Minolta Vivid 910) is used to obtain 3-dimensional surface scans of anatomical structures with a maximum resolution of 0.1mm. Placing the specimen on a turntable allows multiple scans allaround because the scanner only captures data from the portion facing its lens. A computer model is generated using 3D modeling software such as Geomagic. The 3D model can be manipulated on screen for repeated analysis of anatomical features, a useful capability when the specimens are rare or inaccessible (museum collection, fossils, imprints in rock formation.). As accurate measurements can be performed on the computer model, instead of taking measurements on actual specimens only at the archeological excavation site e.g., a variety of quantitative data can be later obtained on the computer model in the laboratory as new ideas come to mind. Our group had used a mechanical contact digitizer (Microscribe) for this purpose, but with the surface digitizer, we have been obtaining data sets more accurately and more quickly.

  1. Dynamic complex optical fields for optical manipulation, 3D microscopy, and photostimulation of neurotransmitters

    NASA Astrophysics Data System (ADS)

    Daria, Vincent R.; Stricker, Christian; Bekkers, John; Redman, Steve; Bachor, Hans

    2010-08-01

    We demonstrate a multi-functional system capable of multiple-site two-photon excitation of photo-sensitive compounds as well as transfer of optical mechanical properties on an array of mesoscopic particles. We use holographic projection of a single Ti:Sapphire laser operating in femtosecond pulse mode to show that the projected three-dimensional light patterns have sufficient spatiotemporal photon density for multi-site two-photon excitation of biological fluorescent markers and caged neurotransmitters. Using the same laser operating in continuous-wave mode, we can use the same light patterns for non-invasive transfer of both linear and orbital angular momentum on a variety of mesoscopic particles. The system also incorporates high-speed scanning using acousto-optic modulators to rapidly render 3D images of neuron samples via two-photon microscopy.

  2. Integration of 3D anatomical data obtained by CT imaging and 3D optical scanning for computer aided implant surgery

    PubMed Central

    2011-01-01

    Background A precise placement of dental implants is a crucial step to optimize both prosthetic aspects and functional constraints. In this context, the use of virtual guiding systems has been recognized as a fundamental tool to control the ideal implant position. In particular, complex periodontal surgeries can be performed using preoperative planning based on CT data. The critical point of the procedure relies on the lack of accuracy in transferring CT planning information to surgical field through custom-made stereo-lithographic surgical guides. Methods In this work, a novel methodology is proposed for monitoring loss of accuracy in transferring CT dental information into periodontal surgical field. The methodology is based on integrating 3D data of anatomical (impression and cast) and preoperative (radiographic template) models, obtained by both CT and optical scanning processes. Results A clinical case, relative to a fully edentulous jaw patient, has been used as test case to assess the accuracy of the various steps concurring in manufacturing surgical guides. In particular, a surgical guide has been designed to place implants in the bone structure of the patient. The analysis of the results has allowed the clinician to monitor all the errors, which have been occurring step by step manufacturing the physical templates. Conclusions The use of an optical scanner, which has a higher resolution and accuracy than CT scanning, has demonstrated to be a valid support to control the precision of the various physical models adopted and to point out possible error sources. A case study regarding a fully edentulous patient has confirmed the feasibility of the proposed methodology. PMID:21338504

  3. Automated multilayer segmentation and characterization in 3D spectral-domain optical coherence tomography images

    NASA Astrophysics Data System (ADS)

    Hu, Zhihong; Wu, Xiaodong; Hariri, Amirhossein; Sadda, SriniVas R.

    2013-03-01

    Spectral-domain optical coherence tomography (SD-OCT) is a 3-D imaging technique, allowing direct visualization of retinal morphology and architecture. The various layers of the retina may be affected differentially by various diseases. In this study, an automated graph-based multilayer approach was developed to sequentially segment eleven retinal surfaces including the inner retinal bands to the outer retinal bands in normal SD-OCT volume scans at three different stages. For stage 1, the four most detectable and/or distinct surfaces were identified in the four-times-downsampled images and were used as a priori positional information to limit the graph search for other surfaces at stage 2. Eleven surfaces were then detected in the two-times-downsampled images at stage 2, and refined in the original image space at stage 3 using the graph search integrating the estimated morphological shape models. Twenty macular SD-OCT (Heidelberg Spectralis) volume scans from 20 normal subjects (one eye per subject) were used in this study. The overall mean and absolute mean differences in border positions between the automated and manual segmentation for all 11 segmented surfaces were -0.20 +/- 0.53 voxels (-0.76 +/- 2.06 μm) and 0.82 +/- 0.64 voxels (3.19 +/- 2.46 μm). Intensity and thickness properties in the resultant retinal layers were investigated. This investigation in normal subjects may provide a comparative reference for subsequent investigations in eyes with disease.

  4. 3D range image resampling using B-spline surface fitting

    NASA Astrophysics Data System (ADS)

    Li, Songtao; Zhao, Dongming

    2000-05-01

    Many optical range sensors use an Equal Angle Increment (EAI) sampling. This type of sensors uses rotating mirrors with constant angular velocity for radar and triangulation techniques, where the sensor sends and receives modulated coherent light through the mirror. Such an EAI model generates data for surface geometrical description that has to be converted, in many applications, into data which meet the desired Equal Distance Increment orthographic projection model. For an accurate analysis in 3D images, an interpolation scheme is needed to resample the range data into spatially equally-distance sampling data that emulate the Cartesian orthographic projection model. In this paper, a resampling approach using a B-Spline surface fitting is proposed. The first step is to select a new scale for all X, Y, Z directions based on the 3D Cartesian coordinates of range data obtained from the sensor parameters. The size of the new range image and the new coordinates of each point are then computed. The new range value is obtained using a B-Spline surface fitting based on the new Cartesian coordinates. The experiments show that this resampling approach provides a geometrically accurate solution for many industrial applications which deploy the EAI sampling sensors.

  5. Visual Short-Term Memory Benefit for Objects on Different 3-D Surfaces

    ERIC Educational Resources Information Center

    Xu, Yaoda; Nakayama, Ken

    2007-01-01

    Visual short-term memory (VSTM) plays an important role in visual cognition. Although objects are located on different 3-dimensional (3-D) surfaces in the real world, how VSTM capacity may be influenced by the presence of multiple 3-D surfaces has never been examined. By manipulating binocular disparities of visual displays, the authors found that…

  6. Surface-Area-Based Attribute Filtering in 3D

    NASA Astrophysics Data System (ADS)

    Kiwanuka, Fred N.; Ouzounis, Georgios K.; Wilkinson, Michael H. F.

    In this paper we describe a rotation-invariant attribute filter based on estimating the sphericity or roundness of objects by efficiently computing surface area and volume of connected components. The method is based on an efficient algorithm to compute all iso-surfaces of all nodes in a Max-Tree. With similar properties to moment-based attributes like sparseness, non-compactness, and elongation, our sphericity attribute can supplement these in finding blood-vessels in time-of-flight MR angiograms. We compare the method to a discrete surface area method based on adjacency, which has been used for urinary stone detection. Though the latter is faster, it is less accurate, and lacks rotation invariance.

  7. Inspection, 3D modelling, and rapid prototyping of cultural heritage by means of a 3D optical digitiser

    NASA Astrophysics Data System (ADS)

    Docchio, F.; Sansoni, G.; Trebeschi, M.

    2005-06-01

    This paper presents the activity carried out to perform the three-dimensional acquisition of the "Vittoria Alata", a 2m-high, bronze statue, symbol of our City, located at the Civici Musei di Arte e Storia (S. Giulia) of Brescia. The acquisition of the statue has been performed by using a three-dimensional vision system based on active triangulation and on the projection of non-coherent light. This system, called OPL-3D, represents one of the research products of our Laboratory, which has been active for years in the development of techniques and systems for the contactless acquisition of free-form, complex shapes. The study, originally motivated by the need to explore a new hypothesis on the origin of the "Vittoria Alata", led to its complete digitization and description in terms of both polygonal and NURBS-based models. A suite of copies of the whole statue has been obtained in the framework of the collaboration between the City Museum and the EOS Electro Optical Systems GmbH, located in Munich, Germany. As a first step, one 30 cm-high replica of the whole statue has been produced using a low-resolution triangle model of the statue (3.5 millions of triangles). As a second step, two 1:1 scale copies of the statue have been produced. For them, the Laboratory has provided the high resolution STL file (16 millions of triangles). The paper discusses in detail the hardware and the software facilities used to implement the whole process, and gives a comprehensive description of the results.

  8. Nanoimprint of a 3D structure on an optical fiber for light wavefront manipulation

    NASA Astrophysics Data System (ADS)

    Calafiore, Giuseppe; Koshelev, Alexander; Allen, Frances I.; Dhuey, Scott; Sassolini, Simone; Wong, Edward; Lum, Paul; Munechika, Keiko; Cabrini, Stefano

    2016-09-01

    Integration of complex photonic structures onto optical fiber facets enables powerful platforms with unprecedented optical functionalities. Conventional nanofabrication technologies, however, do not permit viable integration of complex photonic devices onto optical fibers owing to their low throughput and high cost. In this paper we report the fabrication of a three-dimensional structure achieved by direct nanoimprint lithography on the facet of an optical fiber. Nanoimprint processes and tools were specifically developed to enable a high lithographic accuracy and coaxial alignment of the optical device with respect to the fiber core. To demonstrate the capability of this new approach, a 3D beam splitter has been designed, imprinted and optically characterized. Scanning electron microscopy and optical measurements confirmed the good lithographic capabilities of the proposed approach as well as the desired optical performance of the imprinted structure. The inexpensive solution presented here should enable advancements in areas such as integrated optics and sensing, achieving enhanced portability and versatility of fiber optic components.

  9. Nanoimprint of a 3D structure on an optical fiber for light wavefront manipulation.

    PubMed

    Calafiore, Giuseppe; Koshelev, Alexander; Allen, Frances I; Dhuey, Scott; Sassolini, Simone; Wong, Edward; Lum, Paul; Munechika, Keiko; Cabrini, Stefano

    2016-09-16

    Integration of complex photonic structures onto optical fiber facets enables powerful platforms with unprecedented optical functionalities. Conventional nanofabrication technologies, however, do not permit viable integration of complex photonic devices onto optical fibers owing to their low throughput and high cost. In this paper we report the fabrication of a three-dimensional structure achieved by direct nanoimprint lithography on the facet of an optical fiber. Nanoimprint processes and tools were specifically developed to enable a high lithographic accuracy and coaxial alignment of the optical device with respect to the fiber core. To demonstrate the capability of this new approach, a 3D beam splitter has been designed, imprinted and optically characterized. Scanning electron microscopy and optical measurements confirmed the good lithographic capabilities of the proposed approach as well as the desired optical performance of the imprinted structure. The inexpensive solution presented here should enable advancements in areas such as integrated optics and sensing, achieving enhanced portability and versatility of fiber optic components.

  10. Emergent surface superconductivity in a 3D topological insulator

    NASA Astrophysics Data System (ADS)

    Krusin-Elbaum, Lia

    Surfaces of three-dimensional topological insulators have emerged as one of the most remarkable states of condensed quantum matter where exotic charge and spin phases of Dirac particles could form. This work reports on novel mesoscopic superconductivity in the topological insulator Sb2Te3 with transition to zero resistance induced through a minor tuning of growth chemistry that depletes bulk conduction channels. The depletion shifts Fermi energy towards the Dirac point as witnessed by a factor of 300 reduction of bulk carrier density and by the largest carrier mobility (>25, 000 cm2V-1s-1) found in any topological material of this class. Direct evidence from transport, the unprecedentedly large diamagnetic screening, and the presence of ~ 25 meV gaps detected by scanning tunneling spectroscopy reveal the superconducting condensate to emerge first in surface puddles at unexpectedly high temperature of ~ 50 K, with the onset of global phase coherence at ~ 9 K. The unconventional spin response of Sb2Te3 and the presence of subsurface 2DEG quantum well states arising from charge transfer to the surface are likely to play a role in the emergent superconducting state. The rich structure of this state lends itself to manipulation via growth conditions and the material parameters such as Fermi velocity and mean free path. This work was supported by NSF DMR-1122594, DMR-1420634, DMR-1322483, and DOD-W911NF-13-1-0159.

  11. Snapshots: a novel local surface descriptor and matching algorithm for robust 3D surface alignment.

    PubMed

    Malassiotis, Sotiris; Strintzis, Michael G

    2007-07-01

    In this paper, a novel local surface descriptor is proposed and applied to the problem of aligning partial views of a 3D object. The descriptor is based on taking "snapshots" of the surface over each point using a virtual camera oriented perpendicularly to the surface. This representation has the advantage of imposing minimal loss of information be robust to self-occlusions and also be very efficient to compute. Then, we describe an efficient search technique to deal with the rotation ambiguity of our representation and experimentally demonstrate the benefits of our approaches which are pronounced especially when we align views with small overlap. PMID:17496386

  12. To 3D or Not to 3D, That Is the Question: Do 3D Surface Analyses Improve the Ecomorphological Power of the Distal Femur in Placental Mammals?

    PubMed Central

    Gould, Francois D. H.

    2014-01-01

    Improvements in three-dimensional imaging technologies have renewed interest in the study of functional and ecological morphology. Quantitative approaches to shape analysis are used increasingly to study form-function relationships. These methods are computationally intensive, technically demanding, and time-consuming, which may limit sampling potential. There have been few side-by-side comparisons of the effectiveness of such approaches relative to more traditional analyses using linear measurements and ratios. Morphological variation in the distal femur of mammals has been shown to reflect differences in locomotor modes across clades. Thus I tested whether a geometric morphometric analysis of surface shape was superior to a multivariate analysis of ratios for describing ecomorphological patterns in distal femoral variation. A sample of 164 mammalian specimens from 44 genera was assembled. Each genus was assigned to one of six locomotor categories. The same hypotheses were tested using two methods. Six linear measurements of the distal femur were taken with calipers, from which four ratios were calculated. A 3D model was generated with a laser scanner, and analyzed using three dimensional geometric morphometrics. Locomotor category significantly predicted variation in distal femoral morphology in both analyses. Effect size was larger in the geometric morphometric analysis than in the analysis of ratios. Ordination reveals a similar pattern with arboreal and cursorial taxa as extremes on a continuum of morphologies in both analyses. Discriminant functions calculated from the geometric morphometric analysis were more accurate than those calculated from ratios. Both analysis of ratios and geometric morphometric surface analysis reveal similar, biologically meaningful relationships between distal femoral shape and locomotor mode. The functional signal from the morphology is slightly higher in the geometric morphometric analysis. The practical costs of conducting these

  13. Brownian nanoimaging of interface dynamics and ligand-receptor binding at cell surfaces in 3-D.

    PubMed

    Kuznetsov, Igor R; Evans, Evan A

    2013-04-01

    We describe a method for nanoimaging interfacial dynamics and ligand-receptor binding at surfaces of live cells in 3-D. The imaging probe is a 1-μm diameter glass bead confined by a soft laser trap to create a "cloud" of fluctuating states. Using a facile on-line method of video image analysis, the probe displacements are reported at ~10 ms intervals with bare precisions (±SD) of 4-6 nm along the optical axis (elevation) and 2 nm in the transverse directions. We demonstrate how the Brownian distributions are analyzed to characterize the free energy potential of each small probe in 3-D taking into account the blur effect of its motions during CCD image capture. Then, using the approach to image interactions of a labeled probe with lamellae of leukocytic cells spreading on cover-glass substrates, we show that deformations of the soft distribution in probe elevations provide both a sensitive long-range sensor for defining the steric topography of a cell lamella and a fast telemetry for reporting rare events of probe binding with its surface receptors. Invoking established principles of Brownian physics and statistical thermodynamics, we describe an off-line method of super resolution that improves precision of probe separations from a non-reactive steric boundary to ~1 nm.

  14. Nondestructive optical testing of 3D disperse systems with micro- and nano-particles

    NASA Astrophysics Data System (ADS)

    Bezrukova, Alexandra G.

    2005-04-01

    Nondestructive testing and analysis of three-dimensional (3D) disperse systems (DS) with micro- and nano-particles of different nature by complex of optical compatible methods can provide further progress in on-line control of water and air. The simultaneous analysis of 3D-DS by refractometry, absorbency, fluorescence and by different types of light scattering can help to elaborate the sensing elements for specific impurity control. In our research we have investigated by complex of optical methods different 3D-DS such as: proteins, nucleoproteids, lipoproteids, liposomes, viruses, virosomes, lipid emulsions, blood substitutes, latexes, liquid crystals, biological cells with various form and size (including bacterial cells), metallic powders, clays, kimberlites, zeolites, oils, crude oils, etc., and mixtures -- proteins with nucleic acids, liposomes and viruses, liquid crystals with surfactants, mixtures of clay with bacterial cells, samples of natural and water-supply waters, etc. This experience suggests that the set of optical parameters of so called second class is unique for each 3D-DS. In another words each DS can be characterized by n-dimensional vector in n-dimensional space of optical parameters. Mixtures can be considered as polycomponent and polymodal 3D-DS (such as natural water and air). Due to the fusion of various optical data it is possible to indicate by information statistical theory the inverse physical problem on the presence of impurities in mixtures (viruses, bacteria, oil, metallic particles, etc.), and in this case polymodality of particle size distribution is not an obstacle. Bank of optical data for 3D-DS is the base for analysis by information-statistical method.

  15. Surface gloss and color perception of 3D objects

    PubMed Central

    Xiao, Bei; Brainard, David H.

    2008-01-01

    Two experiments explore the color perception of objects in complex scenes. The first experiment examines the color perception of objects across variation in surface gloss. Observers adjusted the color appearance of a matte sphere to match that of a test sphere. Across conditions we varied the body color and glossiness of the test sphere. The data indicate that observers do not simply match the average light reflected from the test. Indeed, the visual system compensates for the physical effect of varying the gloss, so that appearance is stabilized relative to what is predicted by the spatial average. The second experiment examines how people perceive color across locations on an object. We replaced the test sphere with a soccer ball that had one of its hexagonal faces colored. Observers were asked to adjust the match sphere have the same color appearance as this test patch. The test patch could be located at either an upper or lower location on the soccer ball. In addition, we varied the surface gloss of the entire soccer ball (including the test patch). The data show that there is an effect of test patch location on observers’ color matching, but this effect is small compared to the physical change in the average light reflected from the test patch across the two locations. In addition, the effect of glossy highlights on the color appearance of the test patch was consistent with the results from Experiment 1. PMID:18598406

  16. Improving segmentation of 3D touching cell nuclei using flow tracking on surface meshes.

    PubMed

    Li, Gang; Guo, Lei

    2012-01-01

    Automatic segmentation of touching cell nuclei in 3D microscopy images is of great importance in bioimage informatics and computational biology. This paper presents a novel method for improving 3D touching cell nuclei segmentation. Given binary touching nuclei by the method in Li et al. (2007), our method herein consists of several steps: surface mesh reconstruction and curvature information estimation; direction field diffusion on surface meshes; flow tracking on surface meshes; and projection of surface mesh segmentation to volumetric images. The method is validated on both synthesised and real 3D touching cell nuclei images, demonstrating its validity and effectiveness.

  17. Complementary cellophane optic gate and its use for a 3D iPad without glasses

    NASA Astrophysics Data System (ADS)

    Iizuka, K.

    2012-04-01

    A complementary cellophane optic gate was fabricated using a birefringent cellophane sheet. Previous versions of the optic gate required the retardance of the cellophane to be as close to 180° as possible throughout the entire visible wavelength range, which meant it was often difficult to find a cellophane sheet with the right thickness and dispersion characteristics to meet this requirement. The complementary optic gate reported in this paper has no restriction on the thickness, composition, or wavelength range of the cellophane sheet except that the cellophane must have some birefringence. Even with an arbitrary retardance, an extinction ratio of 5 × 10-3 was achieved at λ = 0.63 μm. The optic gate was used to convert an iPad into a 3D display without the need for the observer to wear glasses. The high extinction ratio of the optic gate resulted in a 3D display of supreme quality.

  18. 3-D segmentation of retinal blood vessels in spectral-domain OCT volumes of the optic nerve head

    NASA Astrophysics Data System (ADS)

    Lee, Kyungmoo; Abràmoff, Michael D.; Niemeijer, Meindert; Garvin, Mona K.; Sonka, Milan

    2010-03-01

    Segmentation of retinal blood vessels can provide important information for detecting and tracking retinal vascular diseases including diabetic retinopathy, arterial hypertension, arteriosclerosis and retinopathy of prematurity (ROP). Many studies on 2-D segmentation of retinal blood vessels from a variety of medical images have been performed. However, 3-D segmentation of retinal blood vessels from spectral-domain optical coherence tomography (OCT) volumes, which is capable of providing geometrically accurate vessel models, to the best of our knowledge, has not been previously studied. The purpose of this study is to develop and evaluate a method that can automatically detect 3-D retinal blood vessels from spectral-domain OCT scans centered on the optic nerve head (ONH). The proposed method utilized a fast multiscale 3-D graph search to segment retinal surfaces as well as a triangular mesh-based 3-D graph search to detect retinal blood vessels. An experiment on 30 ONH-centered OCT scans (15 right eye scans and 15 left eye scans) from 15 subjects was performed, and the mean unsigned error in 3-D of the computer segmentations compared with the independent standard obtained from a retinal specialist was 3.4 +/- 2.5 voxels (0.10 +/- 0.07 mm).

  19. 3D printing of tissue-simulating phantoms as a traceable standard for biomedical optical measurement

    NASA Astrophysics Data System (ADS)

    Dong, Erbao; Wang, Minjie; Shen, Shuwei; Han, Yilin; Wu, Qiang; Xu, Ronald

    2016-01-01

    Optical phantoms are commonly used to validate and calibrate biomedical optical devices in order to ensure accurate measurement of optical properties in biological tissue. However, commonly used optical phantoms are based on homogenous materials that reflect neither optical properties nor multi-layer heterogeneities of biological tissue. Using these phantoms for optical calibration may result in significant bias in biological measurement. We propose to characterize and fabricate tissue simulating phantoms that simulate not only the multi-layer heterogeneities but also optical properties of biological tissue. The tissue characterization module detects tissue structural and functional properties in vivo. The phantom printing module generates 3D tissue structures at different scales by layer-by-layer deposition of phantom materials with different optical properties. The ultimate goal is to fabricate multi-layer tissue simulating phantoms as a traceable standard for optimal calibration of biomedical optical spectral devices.

  20. Air-structured optical fibre drawn from a 3D-printed preform

    NASA Astrophysics Data System (ADS)

    Cook, Kevin; Leon-Saval, Sergio; Canning, John; Reid, Zane; Hossain, Md. Arafat; Peng, Gang-Ding

    2015-09-01

    We report the first optical fibre drawn from a 3D-printed preform. An air-structured polymer preform is printed using a modified butadiene plastic called Bendlay as opposed to the more-common Acrylonitrile Butadiene Styrene (ABS). The preform is subsequently drawn to fibre form at a relatively low temperature of 160 °C and maintains its air-structured cladding holes. Such ability to freely-design and 3D-print complex preform structures, such as photonic bandgap and photonic crystal structures, opens up an exciting new front in optical fibre fabrication.

  1. Near-infrared optical imaging of human brain based on the semi-3D reconstruction algorithm

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Meng, Wei; Qin, Zhuanping; Zhou, Xiaoqing; Zhao, Huijuan; Gao, Feng

    2013-03-01

    In the non-invasive brain imaging with near-infrared light, precise head model is of great significance to the forward model and the image reconstruction. To deal with the individual difference of human head tissues and the problem of the irregular curvature, in this paper, we extracted head structure with Mimics software from the MRI image of a volunteer. This scheme makes it possible to assign the optical parameters to every layer of the head tissues reasonably and solve the diffusion equation with the finite-element analysis. During the solution of the inverse problem, a semi-3D reconstruction algorithm is adopted to trade off the computation cost and accuracy between the full 3-D and the 2-D reconstructions. In this scheme, the changes in the optical properties of the inclusions are assumed either axially invariable or confined to the imaging plane, while the 3-D nature of the photon migration is still retained. This therefore leads to a 2-D inverse issue with the matched 3-D forward model. Simulation results show that comparing to the 3-D reconstruction algorithm, the Semi-3D reconstruction algorithm cut 27% the calculation time consumption.

  2. Quantifying axis orientation in 3D using polarization-sensitive optical coherence tomography (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Liu, Chao; Black, Adam J.; Wang, Hui; Akkin, Taner

    2016-03-01

    The optic axis of birefringent tissues indicates the direction of structural anisotropy. Polarization-sensitive Optical Coherence Tomography (PS-OCT) can provide reflectivity contrast as well as retardance and optic axis orientation contrasts that originate from tissue birefringence. We introduce imaging 3D tissue anisotropy by using a single-camera and polarization-maintaining fiber (PMF) based PS-OCT, which utilizes normal and angled illuminations. Because environmental factors such as the movement of PMF and temperature fluctuations induce arbitrary phase changes, the optic axis orientation measurement has a time-varying offset. In order to measure the absolute axis orientation, we add a calibration path which dynamically provides the arbitrary offset to be subtracted from the relative axis orientation values. The axis orientation on the normal plane is the 2D projection of the fiber direction in 3D space. We propose to characterize the axis orientation in different planes (xy, xy' and x'y planes) by using normal and angled illuminations. This allows calculation of the polar angle that completes the orientation information in 3D. Polarization-based optical systems relying on one illumination angle measure the "apparent birefringence" that light encounters rather than the "true birefringence". Birefringence as a measure of anisotropy is quantified with the orientation information in 3D. The method and validation with a biological tissue are presented. The study can facilitate imaging and mapping the structural connections in anisotropic tissues including the brain.

  3. Sub-millimeter resolution 3D optical imaging of living tissue using laminar optical tomography

    PubMed Central

    Hillman, Elizabeth M. C.; Burgess, Sean A.

    2009-01-01

    In-vivo imaging of optical contrast in living tissues can allow measurement of functional parameters such as blood oxygenation and detection of targeted and active fluorescent contrast agents. However, optical imaging must overcome the effects of light scattering, which limit the penetration depth and can affect quantitation and sensitivity. This article focuses on a technique for high-resolution, high-speed depth-resolved optical imaging of superficial living tissues called laminar optical tomography (LOT), which is capable of imaging absorbing and fluorescent contrast in living tissues to depths of 2–3 mm with 100–200 micron resolution. An overview of the advantages and challenges of in-vivo optical imaging is followed by a review of currently available techniques for high-resolution optical imaging of tissues. LOT is then described, including a description of the imaging system design and discussion of data analysis and image reconstruction approaches. Examples of recent applications of LOT are then provided and compared to other existing technologies. By measuring multiply-scattered light, Laminar Optical Tomography can probe beneath the surface of living tissues such as the skin and brain. PMID:19844595

  4. Viewpoint-independent 3D object segmentation for randomly stacked objects using optical object detection

    NASA Astrophysics Data System (ADS)

    Chen, Liang-Chia; Nguyen, Thanh-Hung; Lin, Shyh-Tsong

    2015-10-01

    This work proposes a novel approach to segmenting randomly stacked objects in unstructured 3D point clouds, which are acquired by a random-speckle 3D imaging system for the purpose of automated object detection and reconstruction. An innovative algorithm is proposed; it is based on a novel concept of 3D watershed segmentation and the strategies for resolving over-segmentation and under-segmentation problems. Acquired 3D point clouds are first transformed into a corresponding orthogonally projected depth map along the optical imaging axis of the 3D sensor. A 3D watershed algorithm based on the process of distance transformation is then performed to detect the boundary, called the edge dam, between stacked objects and thereby to segment point clouds individually belonging to two stacked objects. Most importantly, an object-matching algorithm is developed to solve the over- and under-segmentation problems that may arise during the watershed segmentation. The feasibility and effectiveness of the method are confirmed experimentally. The results reveal that the proposed method is a fast and effective scheme for the detection and reconstruction of a 3D object in a random stack of such objects. In the experiments, the precision of the segmentation exceeds 95% and the recall exceeds 80%.

  5. Cell Proliferation on Macro/Nano Surface Structure and Collagen Immobilization of 3D Polycaprolactone Scaffolds.

    PubMed

    Park, Young-Ouk; Myung, Sung-Woon; Kook, Min-Suk; Jung, Sang-Chul; Kim, Byung-Hoon

    2016-02-01

    In this study, 3D polycaprolactone (PCL) scaffolds were fabricated by 3D printing technique. The macro/nano morphology of, 3D PCL scaffolds surface was etched with oxygen plasma. Acrylic acid (AA) plasma-polymerization was performed to functionalize the macro/nano surface with carboxyl groups and then collagen was immobilized with plasma-polymerized 3D PCL scaffolds. After O2 plasma and AA plasma-polymerization, contact angles were decreased. The FE-SEM and AFM results showed that O2 plasma is increased the surface roughness. The MTT assay results showed that proliferation of the M3CT3-E1 cells increased on the oxygen plasma treated and collagen immobilized 3D PCL scaffolds. PMID:27433597

  6. 3D reconstruction of coronary arteries using frequency domain optical coherence tomography images and biplane angiography.

    PubMed

    Athanasiou, L S; Bourantas, C V; Siogkas, P K; Sakellarios, A I; Exarchos, T P; Naka, K K; Papafaklis, M I; Michalis, L K; Prati, F; Fotiadis, D I

    2012-01-01

    The aim of this study is to describe a new method for three-dimensional (3D) reconstruction of coronary arteries using Frequency Domain Optical Coherence Tomography (FD-OCT) images. The rationale is to fuse the information about the curvature of the artery, derived from biplane angiographies, with the information regarding the lumen wall, which is produced from the FD-OCT examination. The method is based on a three step approach. In the first step the lumen borders in FD-OCT images are detected. In the second step a 3D curve is produced using the center line of the vessel from the two biplane projections. Finally in the third step the detected lumen borders are placed perpendicularly onto the path based on the centroid of each lumen border. The result is a 3D reconstructed artery produced by all the lumen borders of the FD-OCT pullback representing the 3D arterial geometry of the vessel.

  7. Metal-mesh based transparent electrode on a 3-D curved surface by electrohydrodynamic jet printing

    NASA Astrophysics Data System (ADS)

    Seong, Baekhoon; Yoo, Hyunwoong; Dat Nguyen, Vu; Jang, Yonghee; Ryu, Changkook; Byun, Doyoung

    2014-09-01

    Invisible Ag mesh transparent electrodes (TEs), with a width of 7 μm, were prepared on a curved glass surface by electrohydrodynamic (EHD) jet printing. With a 100 μm pitch, the EHD jet printed the Ag mesh on the convex glass which had a sheet resistance of 1.49 Ω/□. The printing speed was 30 cm s-1 using Ag ink, which had a 10 000 cPs viscosity and a 70 wt% Ag nanoparticle concentration. We further showed the performance of a 3-D transparent heater using the Ag mesh transparent electrode. The EHD jet printed an invisible Ag grid transparent electrode with good electrical and optical properties with promising applications on printed optoelectronic devices.

  8. Solving tolerancing and 3D beam shaping problems by multifunctional wave optical design

    NASA Astrophysics Data System (ADS)

    Buehling, Sven; Wyrowski, Frank

    2000-10-01

    A strategy for designing optical systems that are optimized for multiple optical functions on the basis of wave optics is presented. Each optical function is composed of an input field, a set of fixed system parameters, and a merit function. A design algorithm is proposed which is applicable for optical systems consisting of an transmission operator followed by an arbitrary linear operator. The goal is to find the transmission operator which is optimal for all optical functions simultaneously. In later design steps, the found transmission operator can be transformed to real optical elements, for instance by using the thin element approximation. It is shown that the algorithm is efficiently applicable by investigating two sample applications for multifunctional wave optical design: the design of tolerant systems and 3D beam shaping.

  9. Review of three-dimensional (3D) surface imaging for oncoplastic, reconstructive and aesthetic breast surgery.

    PubMed

    O'Connell, Rachel L; Stevens, Roger J G; Harris, Paul A; Rusby, Jennifer E

    2015-08-01

    Three-dimensional surface imaging (3D-SI) is being marketed as a tool in aesthetic breast surgery. It has recently also been studied in the objective evaluation of cosmetic outcome of oncological procedures. The aim of this review is to summarise the use of 3D-SI in oncoplastic, reconstructive and aesthetic breast surgery. An extensive literature review was undertaken to identify published studies. Two reviewers independently screened all abstracts and selected relevant articles using specific inclusion criteria. Seventy two articles relating to 3D-SI for breast surgery were identified. These covered endpoints such as image acquisition, calculations and data obtainable, comparison of 3D and 2D imaging and clinical research applications of 3D-SI. The literature provides a favourable view of 3D-SI. However, evidence of its superiority over current methods of clinical decision making, surgical planning, communication and evaluation of outcome is required before it can be accepted into mainstream practice.

  10. Quality Analysis of 3d Surface Reconstruction Using Multi-Platform Photogrammetric Systems

    NASA Astrophysics Data System (ADS)

    Lari, Z.; El-Sheimy, N.

    2016-06-01

    In recent years, the necessity of accurate 3D surface reconstruction has been more pronounced for a wide range of mapping, modelling, and monitoring applications. The 3D data for satisfying the needs of these applications can be collected using different digital imaging systems. Among them, photogrammetric systems have recently received considerable attention due to significant improvements in digital imaging sensors, emergence of new mapping platforms, and development of innovative data processing techniques. To date, a variety of techniques haven been proposed for 3D surface reconstruction using imagery collected by multi-platform photogrammetric systems. However, these approaches suffer from the lack of a well-established quality control procedure which evaluates the quality of reconstructed 3D surfaces independent of the utilized reconstruction technique. Hence, this paper aims to introduce a new quality assessment platform for the evaluation of the 3D surface reconstruction using photogrammetric data. This quality control procedure is performed while considering the quality of input data, processing procedures, and photo-realistic 3D surface modelling. The feasibility of the proposed quality control procedure is finally verified by quality assessment of the 3D surface reconstruction using images from different photogrammetric systems.

  11. Analysis of 3D-printed metal for rapid-prototyped reflective terahertz optics.

    PubMed

    Headland, Daniel; Withayachumnankul, Withawat; Webb, Michael; Ebendorff-Heidepriem, Heike; Luiten, Andre; Abbott, Derek

    2016-07-25

    We explore the potential of 3D metal printing to realize complex conductive terahertz devices. Factors impacting performance such as printing resolution, surface roughness, oxidation, and material loss are investigated via analytical, numerical, and experimental approaches. The high degree of control offered by a 3D-printed topology is exploited to realize a zone plate operating at 530 GHz. Reflection efficiency at this frequency is found to be over 90%. The high-performance of this preliminary device suggest that 3D metal printing can play a strong role in guided-wave and general beam control devices in the terahertz range. PMID:27464185

  12. Analysis of 3D-printed metal for rapid-prototyped reflective terahertz optics

    NASA Astrophysics Data System (ADS)

    Headland, Daniel; Withayachumnankul, Withawat; Webb, Michael; Ebendorff-Heidepriem, Heike; Luiten, Andre; Abbott, Derek

    2016-07-01

    We explore the potential of 3D metal printing to realize complex conductive terahertz devices. Factors impacting performance such as printing resolution, surface roughness, oxidation, and material loss are investigated via analytical, numerical, and experimental approaches. The high degree of control offered by a 3D-printed topology is exploited to realize a zone plate operating at 530 GHz. Reflection efficiency at this frequency is found to be over 90%. The high-performance of this preliminary device suggest that 3D metal printing can play a strong role in guided-wave and general beam control devices in the terahertz range.

  13. Analysis of 3D-printed metal for rapid-prototyped reflective terahertz optics.

    PubMed

    Headland, Daniel; Withayachumnankul, Withawat; Webb, Michael; Ebendorff-Heidepriem, Heike; Luiten, Andre; Abbott, Derek

    2016-07-25

    We explore the potential of 3D metal printing to realize complex conductive terahertz devices. Factors impacting performance such as printing resolution, surface roughness, oxidation, and material loss are investigated via analytical, numerical, and experimental approaches. The high degree of control offered by a 3D-printed topology is exploited to realize a zone plate operating at 530 GHz. Reflection efficiency at this frequency is found to be over 90%. The high-performance of this preliminary device suggest that 3D metal printing can play a strong role in guided-wave and general beam control devices in the terahertz range.

  14. Bone tissue phantoms for optical flowmeters at large interoptode spacing generated by 3D-stereolithography

    PubMed Central

    Binzoni, Tiziano; Torricelli, Alessandro; Giust, Remo; Sanguinetti, Bruno; Bernhard, Paul; Spinelli, Lorenzo

    2014-01-01

    A bone tissue phantom prototype allowing to test, in general, optical flowmeters at large interoptode spacings, such as laser-Doppler flowmetry or diffuse correlation spectroscopy, has been developed by 3D-stereolithography technique. It has been demonstrated that complex tissue vascular systems of any geometrical shape can be conceived. Absorption coefficient, reduced scattering coefficient and refractive index of the optical phantom have been measured to ensure that the optical parameters reasonably reproduce real human bone tissue in vivo. An experimental demonstration of a possible use of the optical phantom, utilizing a laser-Doppler flowmeter, is also presented. PMID:25136496

  15. Bone tissue phantoms for optical flowmeters at large interoptode spacing generated by 3D-stereolithography.

    PubMed

    Binzoni, Tiziano; Torricelli, Alessandro; Giust, Remo; Sanguinetti, Bruno; Bernhard, Paul; Spinelli, Lorenzo

    2014-08-01

    A bone tissue phantom prototype allowing to test, in general, optical flowmeters at large interoptode spacings, such as laser-Doppler flowmetry or diffuse correlation spectroscopy, has been developed by 3D-stereolithography technique. It has been demonstrated that complex tissue vascular systems of any geometrical shape can be conceived. Absorption coefficient, reduced scattering coefficient and refractive index of the optical phantom have been measured to ensure that the optical parameters reasonably reproduce real human bone tissue in vivo. An experimental demonstration of a possible use of the optical phantom, utilizing a laser-Doppler flowmeter, is also presented.

  16. Optical design for uniform scanning in MEMS-based 3D imaging lidar.

    PubMed

    Lee, Xiaobao; Wang, Chunhui

    2015-03-20

    This paper proposes a method for the optical system design of uniform scanning in a larger scan field of view (FOV) in 3D imaging lidar. The theoretical formulas are derived for the design scheme. By employing the optical design software ZEMAX, a foldaway uniform scanning optical system based on MEMS has been designed, and the scanning uniformity and spot size of the system on the target plane, perpendicular to optical axis, are analyzed and discussed. Results show that the designed system can scan uniformly within the FOV of 40°×40° with small spot size for the target at distance of about 100 m. PMID:25968504

  17. Bone tissue phantoms for optical flowmeters at large interoptode spacing generated by 3D-stereolithography.

    PubMed

    Binzoni, Tiziano; Torricelli, Alessandro; Giust, Remo; Sanguinetti, Bruno; Bernhard, Paul; Spinelli, Lorenzo

    2014-08-01

    A bone tissue phantom prototype allowing to test, in general, optical flowmeters at large interoptode spacings, such as laser-Doppler flowmetry or diffuse correlation spectroscopy, has been developed by 3D-stereolithography technique. It has been demonstrated that complex tissue vascular systems of any geometrical shape can be conceived. Absorption coefficient, reduced scattering coefficient and refractive index of the optical phantom have been measured to ensure that the optical parameters reasonably reproduce real human bone tissue in vivo. An experimental demonstration of a possible use of the optical phantom, utilizing a laser-Doppler flowmeter, is also presented. PMID:25136496

  18. Rapid 3D µ-printing of polymer optical whispering-gallery mode resonators.

    PubMed

    Wu, Jushuai; Guo, Xin; Zhang, A Ping; Tam, Hwa-Yaw

    2015-11-16

    A novel microfabrication method for rapid printing of polymer optical whispering-gallery mode (WGM) resonators is presented. A 3D micro-printing technology based on high-speed optical spatial modulator (SLM) and high-power UV light source is developed to fabricate suspended-disk WGM resonator array using SU-8 photoresist. The optical spectral responses of the fabricated polymer WGM resonators were measured with a biconically tapered optical fiber. Experimental results reveal that the demonstrated method is very flexible and time-saving for rapid fabrication of complex polymer WGM resonators. PMID:26698452

  19. Tracking left ventricular borders in 3D echocardiographic sequences using motion-guided optical flow

    NASA Astrophysics Data System (ADS)

    Leung, K. Y. Esther; Danilouchkine, Mikhail G.; van Stralen, Marijn; de Jong, Nico; van der Steen, Antonius F. W.; Bosch, Johan G.

    2009-02-01

    For obtaining quantitative and objective functional parameters from three-dimensional (3D) echocardiographic sequences, automated segmentation methods may be preferable to cumbersome manual delineation of 3D borders. In this study, a novel optical-flow based tracking method is proposed for propagating 3D endocardial contours of the left ventricle throughout the cardiac cycle. To take full advantage of the time-continuous nature of cardiac motion, a statistical motion model was explicitly embedded in the optical flow solution. The cardiac motion was modeled as frame-to-frame affine transforms, which were extracted using Procrustes analysis on a set of training contours. Principal component analysis was applied to obtain a compact model of cardiac motion throughout the whole cardiac cycle. The parameters of this model were resolved in an optical flow manner, via spatial and temporal gradients in image intensity. The algorithm was tested on 36 noncontrast and 28 contrast enhanced 3D echocardiographic sequences in a leave-one-out manner. Good results were obtained using a combination of the proposed motion-guided method and a purely data-driven optical flow approach. The improvement was particularly noticeable in areas where the LV wall was obscured by image artifacts. In conclusion, the results show the applicability of the proposed method in clinical quality echocardiograms.

  20. A new technique of recognition for coded targets in optical 3D measurement

    NASA Astrophysics Data System (ADS)

    Guo, Changye; Cheng, Xiaosheng; Cui, Haihua; Dai, Ning; Weng, Jinping

    2014-11-01

    A new technique for coded targets recognition in optical 3D-measurement application is proposed in this paper. Traditionally, point cloud registration is based on homologous features, such as the curvature, which is time-consuming and not reliable. For this, we paste some coded targets onto the surface of the object to be measured to improve the optimum target location and accurate correspondence among multi-source images. Circular coded targets are used, and an algorithm to automatically detecting them is proposed. This algorithm extracts targets with intensive bimodal histogram features from complex background, and filters noise according to their size, shape and intensity. In addition, the coded targets' identification is conducted out by their ring codes. We affine them around the circle inversely, set foreground and background respectively as 1 and 0 to constitute a binary number, and finally shift one bit every time to calculate a decimal one of the binary number to determine a minimum decimal number as its code. In this 3Dmeasurement application, we build a mutual relationship between different viewpoints containing three or more coded targets with different codes. Experiments show that it is of efficiency to obtain global surface data of an object to be measured and is robust to the projection angles and noise.

  1. Towards non-invasive 3D hepatotoxicity assays with optical coherence phase microscopy

    NASA Astrophysics Data System (ADS)

    Nelson, Leonard J.; Koulovasilopoulos, Andreas; Treskes, Philipp; Hayes, Peter C.; Plevris, John N.; Bagnaninchi, Pierre O.

    2015-03-01

    Three-dimensional tissue-engineered models are increasingly recognised as more physiologically-relevant than standard 2D cell culture for pre-clinical drug toxicity testing. However, many types of conventional toxicity assays are incompatible with dense 3D tissues. This study investigated the use of optical coherence phase microscopy (OCPM) as a novel approach to assess cell death in 3D tissue culture. For 3D micro-spheroid formation Human hepatic C3A cells were encapsulated in hyaluronic acid gels and cultured in 100μl MEME/10%FBS in 96-well plates. After spheroid formation the 3D liver constructs were exposed to acetaminophen on culture day 8. Acetaminophen hepatotoxicity in 3D cultures was evaluated using standard biochemical assays. An inverted OCPM in common path configuration was developed with a Callisto OCT engine (Thorlabs), centred at 930nm and a custom scanning head. Intensity data were used to perform in-depth microstructural imaging. In addition, phase fluctuations were measured by collecting several successive B scans at the same location, and statistics on the first time derivative of the phase, i.e. time fluctuations, were analysed over the acquisition time interval to retrieve overall cell viability. OCPM intensity (cell cluster size) and phase fluctuation statistics were directly compared with biochemical assays. In this study, we investigated optical coherence phase tomography to assess cell death in a 3d liver model after exposure to a prototypical hepatotoxin, acetaminophen. We showed that OCPM has the potential to assess noninvasively and label-free drug toxicity in 3D tissue models.

  2. Performance of an improved first generation optical CT scanner for 3D dosimetry

    NASA Astrophysics Data System (ADS)

    Qian, Xin; Adamovics, John; Wuu, Cheng-Shie

    2013-12-01

    Performance analysis of a modified 3D dosimetry optical scanner based on the first generation optical CT scanner OCTOPUS is presented. The system consists of PRESAGE™ dosimeters, the modified 3D scanner, and a new developed in-house user control panel written in Labview program which provides more flexibility to optimize mechanical control and data acquisition technique. The total scanning time has been significantly reduced from initial 8 h to ∼2 h by using the modified scanner. The functional performance of the modified scanner has been evaluated in terms of the mechanical integrity uncertainty of the data acquisition process. Optical density distribution comparison between the modified scanner, OCTOPUS and the treatment plan system has been studied. It has been demonstrated that the agreement between the modified scanner and treatment plans is comparable with that between the OCTOPUS and treatment plans.

  3. Analytical description of 3D optical pulse diffraction by a phase-shifted Bragg grating.

    PubMed

    Golovastikov, Nikita V; Bykov, Dmitry A; Doskolovich, Leonid L; Soifer, Victor A

    2016-08-22

    Diffraction of a three-dimensional (3D) spatiotemporal optical pulse by a phase-shifted Bragg grating (PSBG) is considered. The pulse diffraction is described in terms of signal transmission through a linear system with a transfer function determined by the reflection or transmission coefficient of the PSBG. Resonant approximations of the reflection and transmission coefficients of the PSBG as functions of the angular frequency and the in-plane component of the wave vector are obtained. Using these approximations, a hyperbolic partial differential equation (Klein-Gordon equation) describing a general class of transformations of the incident 3D pulse envelope is derived. A solution to this equation is found in the form of a convolution integral. The presented rigorous simulation results fully confirm the proposed theoretical description. The obtained results may find application in the design of new devices for spatiotemporal pulse shaping and for optical information processing and analog optical computing. PMID:27557167

  4. Optical clearing based cellular-level 3D visualization of intact lymph node cortex

    PubMed Central

    Song, Eunjoo; Seo, Howon; Choe, Kibaek; Hwang, Yoonha; Ahn, Jinhyo; Ahn, Soyeon; Kim, Pilhan

    2015-01-01

    Lymph node (LN) is an important immune organ that controls adaptive immune responses against foreign pathogens and abnormal cells. To facilitate efficient immune function, LN has highly organized 3D cellular structures, vascular and lymphatic system. Unfortunately, conventional histological analysis relying on thin-sliced tissue has limitations in 3D cellular analysis due to structural disruption and tissue loss in the processes of fixation and tissue slicing. Optical sectioning confocal microscopy has been utilized to analyze 3D structure of intact LN tissue without physical tissue slicing. However, light scattering within biological tissues limits the imaging depth only to superficial portion of LN cortex. Recently, optical clearing techniques have shown enhancement of imaging depth in various biological tissues, but their efficacy for LN are remained to be investigated. In this work, we established optical clearing procedure for LN and achieved 3D volumetric visualization of the whole cortex of LN. More than 4 times improvement in imaging depth was confirmed by using LN obtained from H2B-GFP/actin-DsRed double reporter transgenic mouse. With adoptive transfer of GFP expressing B cells and DsRed expressing T cells and fluorescent vascular labeling by anti-CD31 and anti-LYVE-1 antibody conjugates, we successfully visualized major cellular-level structures such as T-cell zone, B-cell follicle and germinal center. Further, we visualized the GFP expressing metastatic melanoma cell colony, vasculature and lymphatic vessels in the LN cortex. PMID:26504662

  5. Generation of nearly 3D-unpolarized evanescent optical near fields using total internal reflection.

    PubMed

    Hassinen, Timo; Popov, Sergei; Friberg, Ari T; Setälä, Tero

    2016-07-01

    We analyze the time-domain partial polarization of optical fields composed of two evanescent waves created in total internal reflection by random electromagnetic beams with orthogonal planes of incidence. We show that such a two-beam configuration enables to generate nearly unpolarized, genuine three-component (3D) near fields. This result complements earlier studies on spectral polarization, which state that at least three symmetrically propagating beams are required to produce a 3D-unpolarized near field. The degree of polarization of the near field can be controlled by adjusting the polarization states and mutual correlation of the incident beams.

  6. Generation of nearly 3D-unpolarized evanescent optical near fields using total internal reflection.

    PubMed

    Hassinen, Timo; Popov, Sergei; Friberg, Ari T; Setälä, Tero

    2016-07-01

    We analyze the time-domain partial polarization of optical fields composed of two evanescent waves created in total internal reflection by random electromagnetic beams with orthogonal planes of incidence. We show that such a two-beam configuration enables to generate nearly unpolarized, genuine three-component (3D) near fields. This result complements earlier studies on spectral polarization, which state that at least three symmetrically propagating beams are required to produce a 3D-unpolarized near field. The degree of polarization of the near field can be controlled by adjusting the polarization states and mutual correlation of the incident beams. PMID:27367071

  7. Real-time visualization of 3-D dynamic microscopic objects using optical diffraction tomography.

    PubMed

    Kim, Kyoohyun; Kim, Kyung Sang; Park, Hyunjoo; Ye, Jong Chul; Park, Yongkeun

    2013-12-30

    3-D refractive index (RI) distribution is an intrinsic bio-marker for the chemical and structural information about biological cells. Here we develop an optical diffraction tomography technique for the real-time reconstruction of 3-D RI distribution, employing sparse angle illumination and a graphic processing unit (GPU) implementation. The execution time for the tomographic reconstruction is 0.21 s for 96(3) voxels, which is 17 times faster than that of a conventional approach. We demonstrated the real-time visualization capability with imaging the dynamics of Brownian motion of an anisotropic colloidal dimer and the dynamic shape change in a red blood cell upon shear flow.

  8. 3D surface topography study of the biofunctionalized nanocrystalline Ti-6Zr-4Nb/Ca-P

    SciTech Connect

    Jakubowicz, J.; Adamek, G.; Jurczyk, M.U.; Jurczyk, M.

    2012-08-15

    In this work surface of the sintered Ti-6Zr-4Nb nanocrystalline alloy was electrochemically biofunctionalized. The porous surface was produced by anodic oxidation in 1 M H{sub 3}PO{sub 4} + 2%HF electrolyte at 10 V for 30 min. Next the calcium-phosphate (Ca-P) layer was deposited, onto the formed porous surface, using cathodic potential - 5 V kept for 60 min in 0.042 M Ca(NO{sub 3}){sub 2} + 0.025 M (NH{sub 4}){sub 2}HPO{sub 4} + 0.1 M HCl electrolyte. The deposited Ca-P layer anchored in the pores. The biofunctionalized surface was studied by XRD, SEM and EDS. In vitro tests culture of normal human osteoblast (NHOst) cells showed very good cells proliferation, colonization and multilayering. Using optical profiler, roughness and hybrid 3D surface topography parameters were estimated. Correlation between surface composition, morphology, roughness and biocompatibility results was done. It has been shown by us that surface with appropriate chemical composition and topography, after combined electrochemical anodic and cathodic surface treatment, supports osteoblast adhesion and proliferation. 3D topography measurements using optical profiler play a key role in the biomaterials surface analysis. - Highlights: Black-Right-Pointing-Pointer Nanocrystalline Ti-6Zr-4Nb/Ca-P material was produced for hard tissue implant applications. Black-Right-Pointing-Pointer Calcium-phosphate results in surface biofunctionalization. Black-Right-Pointing-Pointer The biofunctionalized surface shows good in-vitro behavior.

  9. Optical design of wavelength selective CPVT system with 3D/2D hybrid concentration

    NASA Astrophysics Data System (ADS)

    Ahmad, N.; Ijiro, T.; Yamada, N.; Kawaguchi, T.; Maemura, T.; Ohashi, H.

    2012-10-01

    Optical design of a concentrating photovoltaic/thermal (CPVT) system is carried out. Using wavelength-selective optics, the system demonstrates 3-D concentration onto a solar cell and 2-D concentration onto a thermal receiver. Characteristics of the two types of concentrator systems are examined with ray-tracing analysis. The first system is a glazed mirror-based concentrator system mounted on a 2-axis pedestal tracker. The size of the secondary optical element is minimized to decrease the cost of the system, and it has a wavelength-selective function for performing 3-D concentration onto a solar cell and 2-D concentration onto a thermal receiver. The second system is a non-glazed beamdown concentrator system containing parabolic mirrors in the lower part. The beam-down selective mirror performs 3-D concentration onto a solar cell placed above the beam-down selective mirror, and 2-D concentration down to a thermal receiver placed at the bottom level. The system is mounted on a two-axis carousel tracker. A parametric study is performed for those systems with different geometrical 2-D/3-D concentration ratios. Wavelength-selective optics such as hot/cold mirrors and spectrum-splitting technologies are taken into account in the analysis. Results show reduced heat load on the solar cell and increased total system efficiency compared to a non-selective CPV system. Requirements for the wavelength-selective properties are elucidated. It is also shown that the hybrid concept with 2-D concentration onto a thermal receiver and 3-D concentration onto a solar cell has an advantageous geometry because of the high total system efficiency and compatibility with the piping arrangement of the thermal receiver.

  10. Combined scanning probe nanotomography and optical microspectroscopy: a correlative technique for 3D characterization of nanomaterials.

    PubMed

    Mochalov, Konstantin E; Efimov, Anton E; Bobrovsky, Alexey; Agapov, Igor I; Chistyakov, Anton A; Oleinikov, Vladimir; Sukhanova, Alyona; Nabiev, Igor

    2013-10-22

    Combination of 3D structural analysis with optical characterization of the same sample area on the nanoscale is a highly demanded approach in nanophotonics, materials science, and quality control of nanomaterial. We have developed a correlative microscopy technique where the 3D structure of the sample is reconstructed on the nanoscale by means of a "slice-and-view" combination of ultramicrotomy and scanning probe microscopy (scanning probe nanotomography, SPNT), and its optical characteristics are analyzed using microspectroscopy. This approach has been used to determine the direct quantitative relationship of the 3D structural characteristics of nanovolumes of materials with their microscopic optical properties. This technique has been applied to 3D structural and optical characterization of a hybrid material consisting of cholesteric liquid crystals doped with fluorescent quantum dots (QDs) that can be used for photochemical patterning and image recording through the changes in the dissymmetry factor of the circular polarization of QD emission. The differences in the polarization images and fluorescent spectra of this hybrid material have proved to be correlated with the arrangement of the areas of homogeneous distribution and heterogeneous clustering of QDs. The reconstruction of the 3D nanostructure of the liquid crystal matrix in the areas of homogeneous QDs distribution has shown that QDs do not perturb the periodic planar texture of the cholesteric liquid crystal matrix, whereas QD clusters do perturb it. The combined microspectroscopy-nanotomography technique will be important for evaluating the effects of nanoparticles on the structural organization of organic and liquid crystal matrices and biomedical materials, as well as quality control of nanotechnology fabrication processes and products.

  11. Combined scanning probe nanotomography and optical microspectroscopy: a correlative technique for 3D characterization of nanomaterials.

    PubMed

    Mochalov, Konstantin E; Efimov, Anton E; Bobrovsky, Alexey; Agapov, Igor I; Chistyakov, Anton A; Oleinikov, Vladimir; Sukhanova, Alyona; Nabiev, Igor

    2013-10-22

    Combination of 3D structural analysis with optical characterization of the same sample area on the nanoscale is a highly demanded approach in nanophotonics, materials science, and quality control of nanomaterial. We have developed a correlative microscopy technique where the 3D structure of the sample is reconstructed on the nanoscale by means of a "slice-and-view" combination of ultramicrotomy and scanning probe microscopy (scanning probe nanotomography, SPNT), and its optical characteristics are analyzed using microspectroscopy. This approach has been used to determine the direct quantitative relationship of the 3D structural characteristics of nanovolumes of materials with their microscopic optical properties. This technique has been applied to 3D structural and optical characterization of a hybrid material consisting of cholesteric liquid crystals doped with fluorescent quantum dots (QDs) that can be used for photochemical patterning and image recording through the changes in the dissymmetry factor of the circular polarization of QD emission. The differences in the polarization images and fluorescent spectra of this hybrid material have proved to be correlated with the arrangement of the areas of homogeneous distribution and heterogeneous clustering of QDs. The reconstruction of the 3D nanostructure of the liquid crystal matrix in the areas of homogeneous QDs distribution has shown that QDs do not perturb the periodic planar texture of the cholesteric liquid crystal matrix, whereas QD clusters do perturb it. The combined microspectroscopy-nanotomography technique will be important for evaluating the effects of nanoparticles on the structural organization of organic and liquid crystal matrices and biomedical materials, as well as quality control of nanotechnology fabrication processes and products. PMID:23991901

  12. 3D Optical Measuring Systems and Laser Technologies for Scientific and Industrial Applications

    NASA Astrophysics Data System (ADS)

    Chugui, Yu.; Verkhoglyad, A.; Poleshchuk, A.; Korolkov, V.; Sysoev, E.; Zavyalov, P.

    2013-12-01

    Modern industry and science require novel 3D optical measuring systems and laser technologies with micro/nanometer resolution for solving actual problems. Such systems, including the 3D dimensional inspection of ceramic parts for electrotechnical industry, laser inspection of wheel pair diagnostic for running trains and 3D superresolution low-coherent micro- /nanoprofilometers are presented. The newest results in the field of laser technologies for high-precision synthesis of microstructures by updated image generator using the semiconductor laser are given. The measuring systems and the laser image generator developed and produced by TDI SIE and IAE SB RAS have been tested by customers and used in different branches of industry and science.

  13. An optical system for detecting 3D high-speed oscillation of a single ultrasound microbubble

    PubMed Central

    Liu, Yuan; Yuan, Baohong

    2013-01-01

    As contrast agents, microbubbles have been playing significant roles in ultrasound imaging. Investigation of microbubble oscillation is crucial for microbubble characterization and detection. Unfortunately, 3-dimensional (3D) observation of microbubble oscillation is challenging and costly because of the bubble size—a few microns in diameter—and the high-speed dynamics under MHz ultrasound pressure waves. In this study, a cost-efficient optical confocal microscopic system combined with a gated and intensified charge-coupled device (ICCD) camera were developed to detect 3D microbubble oscillation. The capability of imaging microbubble high-speed oscillation with much lower costs than with an ultra-fast framing or streak camera system was demonstrated. In addition, microbubble oscillations along both lateral (x and y) and axial (z) directions were demonstrated. Accordingly, this system is an excellent alternative for 3D investigation of microbubble high-speed oscillation, especially when budgets are limited. PMID:24049677

  14. Mesoscopic in vivo 3-D tracking of sparse cell populations using angular multiplexed optical projection tomography

    PubMed Central

    Chen, Lingling; Alexandrov, Yuriy; Kumar, Sunil; Andrews, Natalie; Dallman, Margaret J.; French, Paul M. W.; McGinty, James

    2015-01-01

    We describe an angular multiplexed imaging technique for 3-D in vivo cell tracking of sparse cell distributions and optical projection tomography (OPT) with superior time-lapse resolution and a significantly reduced light dose compared to volumetric time-lapse techniques. We demonstrate that using dual axis OPT, where two images are acquired simultaneously at different projection angles, can enable localization and tracking of features in 3-D with a time resolution equal to the camera frame rate. This is achieved with a 200x reduction in light dose compared to an equivalent volumetric time-lapse single camera OPT acquisition with 200 projection angles. We demonstrate the application of this technique to mapping the 3-D neutrophil migration pattern observed over ~25.5 minutes in a live 2 day post-fertilisation transgenic LysC:GFP zebrafish embryo following a tail wound. PMID:25909009

  15. An optical system for detecting 3D high-speed oscillation of a single ultrasound microbubble.

    PubMed

    Liu, Yuan; Yuan, Baohong

    2013-01-01

    As contrast agents, microbubbles have been playing significant roles in ultrasound imaging. Investigation of microbubble oscillation is crucial for microbubble characterization and detection. Unfortunately, 3-dimensional (3D) observation of microbubble oscillation is challenging and costly because of the bubble size-a few microns in diameter-and the high-speed dynamics under MHz ultrasound pressure waves. In this study, a cost-efficient optical confocal microscopic system combined with a gated and intensified charge-coupled device (ICCD) camera were developed to detect 3D microbubble oscillation. The capability of imaging microbubble high-speed oscillation with much lower costs than with an ultra-fast framing or streak camera system was demonstrated. In addition, microbubble oscillations along both lateral (x and y) and axial (z) directions were demonstrated. Accordingly, this system is an excellent alternative for 3D investigation of microbubble high-speed oscillation, especially when budgets are limited. PMID:24049677

  16. In Situ Fabrication of 3D Ag@ZnO Nanostructures for Microfluidic Surface-Enhanced Raman Scattering Systems

    PubMed Central

    2015-01-01

    In this work, we develop an in situ method to grow highly controllable, sensitive, three-dimensional (3D) surface-enhanced Raman scattering (SERS) substrates via an optothermal effect within microfluidic devices. Implementing this approach, we fabricate SERS substrates composed of Ag@ZnO structures at prescribed locations inside microfluidic channels, sites within which current fabrication of SERS structures has been arduous. Conveniently, properties of the 3D Ag@ZnO nanostructures such as length, packing density, and coverage can also be adjusted by tuning laser irradiation parameters. After exploring the fabrication of the 3D nanostructures, we demonstrate a SERS enhancement factor of up to ∼2 × 106 and investigate the optical properties of the 3D Ag@ZnO structures through finite-difference time-domain simulations. To illustrate the potential value of our technique, low concentrations of biomolecules in the liquid state are detected. Moreover, an integrated cell-trapping function of the 3D Ag@ZnO structures records the surface chemical fingerprint of a living cell. Overall, our optothermal-effect-based fabrication technique offers an effective combination of microfluidics with SERS, resolving problems associated with the fabrication of SERS substrates in microfluidic channels. With its advantages in functionality, simplicity, and sensitivity, the microfluidic-SERS platform presented should be valuable in many biological, biochemical, and biomedical applications. PMID:25402207

  17. Optical absorption enhancement in 3D silicon oxide nano-sandwich type solar cell.

    PubMed

    Kiani, Amirkianoosh; Venkatakrishnan, Krishnan; Tan, Bo

    2014-01-13

    Recent research in the field of photovoltaic and solar cell fabrication has shown the potential to significantly enhance light absorption in thin-film solar cells by using surface texturing and nanostructure coating techniques. In this paper, for the first time, we propose a new method for nano sandwich type thin-film solar cell fabrication by combining the laser amorphization (2nd solar cell generation) and laser nanofibers generation (3rd solar cell generation) techniques. In this novel technique, the crystalline silicon is irradiated by megahertz frequency femtosecond laser pulses under ambient conditions and the multi-layer of amorphorized silicon and nano fibrous layer are generated in the single-step on top of the silicon substrate. Light spectroscopy results show significant enhancement of light absorption in the generated multi layers solar cells (Silicon Oxide nanofibers / thin-film amorphorized silicon). This method is single step and no additional materials are added and both layers of the amorphorized thin-film silicon and three-dimensional (3D) silicon oxide nanofibrous structures are grown on top of the silicon substrate after laser irradiation. Finally, we suggest how to maximize the light trapping and optical absorption of the generated nanofibers/thin-film cells by optimizing the laser pulse duration. PMID:24921988

  18. 3D printing method for freeform fabrication of optical phantoms simulating heterogeneous biological tissue

    NASA Astrophysics Data System (ADS)

    Wang, Minjie; Shen, Shuwei; Yang, Jie; Dong, Erbao; Xu, Ronald

    2014-03-01

    The performance of biomedical optical imaging devices heavily relies on appropriate calibration. However, many of existing calibration phantoms for biomedical optical devices are based on homogenous materials without considering the multi-layer heterogeneous structures observed in biological tissue. Using such a phantom for optical calibration may result in measurement bias. To overcome this problem, we propose a 3D printing method for freeform fabrication of tissue simulating phantoms with multilayer heterogeneous structure. The phantom simulates not only the morphologic characteristics of biological tissue but also absorption and scattering properties. The printing system is based on a 3D motion platform with coordinated control of the DC motors. A special jet nozzle is designed to mix base, scattering, and absorption materials at different ratios. 3D tissue structures are fabricated through layer-by-layer printing with selective deposition of phantom materials of different ingredients. Different mixed ratios of base, scattering and absorption materials have been tested in order to optimize the printing outcome. A spectrometer and a tissue spectrophotometer are used for characterizing phantom absorption and scattering properties. The goal of this project is to fabricate skin tissue simulating phantoms as a traceable standard for the calibration of biomedical optical spectral devices.

  19. Wave optics theory and 3-D deconvolution for the light field microscope

    PubMed Central

    Broxton, Michael; Grosenick, Logan; Yang, Samuel; Cohen, Noy; Andalman, Aaron; Deisseroth, Karl; Levoy, Marc

    2013-01-01

    Light field microscopy is a new technique for high-speed volumetric imaging of weakly scattering or fluorescent specimens. It employs an array of microlenses to trade off spatial resolution against angular resolution, thereby allowing a 4-D light field to be captured using a single photographic exposure without the need for scanning. The recorded light field can then be used to computationally reconstruct a full volume. In this paper, we present an optical model for light field microscopy based on wave optics, instead of previously reported ray optics models. We also present a 3-D deconvolution method for light field microscopy that is able to reconstruct volumes at higher spatial resolution, and with better optical sectioning, than previously reported. To accomplish this, we take advantage of the dense spatio-angular sampling provided by a microlens array at axial positions away from the native object plane. This dense sampling permits us to decode aliasing present in the light field to reconstruct high-frequency information. We formulate our method as an inverse problem for reconstructing the 3-D volume, which we solve using a GPU-accelerated iterative algorithm. Theoretical limits on the depth-dependent lateral resolution of the reconstructed volumes are derived. We show that these limits are in good agreement with experimental results on a standard USAF 1951 resolution target. Finally, we present 3-D reconstructions of pollen grains that demonstrate the improvements in fidelity made possible by our method. PMID:24150383

  20. Writing of 3D optical integrated circuits with ultrashort laser pulses in the presence of strong spherical aberration

    NASA Astrophysics Data System (ADS)

    Bukharin, M. A.; Skryabin, N. N.; Khudyakov, D. V.; Vartapetov, S. K.

    2016-09-01

    A novel technique was proposed for 3D femtosecond writing of waveguides and optical integrated circuits in the presence of strong spherical aberration, caused by inscription at significantly different depth under the surface of optical glasses and crystals. Strong negative effect of spherical aberration and related asymmetry of created structures was reduced due to transition to the cumulative thermal regime of femtosecond interaction with the material. The differences in the influence of spherical aberration effect in a broad depth range (larger than 200 µm) was compensated by dynamic adjustment of laser pulse energy during the process of waveguides recording. The presented approach has been experimentally implemented in fused silica. Obtained results can be used in production of a broad class of femtosecond written three-dimensional integrated optical systems, inscripted at non-optimal (for focusing lens) optical depth or in significantly extended range of depths.

  1. Estimation of 3-D Cloud Effects on TOMS Satellite Retrieval of Surface UV Irradiance

    NASA Technical Reports Server (NTRS)

    Krotkov, Nickolay A.; Geogdzhayev, I.; Herman, J. R.

    1998-01-01

    To improve surface UV irradiance retrieval from the Total Ozone Mapping Spectrometer (TOMS) we simulate errors of the TOMS cloud correction algorithm for summertime broken cloud conditions. Cloud scenes (50 km by 50 km) are modeled by a normal random (Gaussian) field with a fixed lower boundary and conservative scattering. The model relates stochastic field characteristics with the cloud amount, mean cloud diameter and aspect ratio. Clouds are embedded into Rayleigh atmosphere with standard ozone profile. Radiative transfer calculations of the radiance at the top of the atmosphere and irradiance at the surface were performed using 3-D Monte Carlo (MC) code. The results are averaged over the satellite field of view on the surface (50 km by 50 km) and compared with TOMS predicted surface irradiance for the same scene reflectance. The TOMS algorithm assumes horizontally homogeneous Cl-type cloud between 3 km and 5.5 km. The effective optical depth is determined by fitting observed (MC) radiance at 380 nm. Having the same radiance at the satellite the homogeneous and broken cloud models predict different average irradiances at the surface. This is due to the differences in Bidirectional Reflection Distribution Function (BRDF) for homogeneous and broken cloud scenes with the same hemispherical albedo. For typical TOMS observational geometry at mid-latitudes the simulated single pixels errors may be as large as +/- 20%. Qualitatively these errors are due to the dominance of the non-horizontal cloud surfaces, which are not accounted for in the homogeneous cloud model. However, due to high variability of the real cloud shapes and types it is unclear how these single pixel errors would affect TOMS time-integrated UV exposure over extended periods (weeks to months) for different regions.

  2. Fish body surface data measurement based on 3D digital image correlation

    NASA Astrophysics Data System (ADS)

    Jiang, Ming; Qian, Chen; Yang, Wenkai

    2016-01-01

    To film the moving fish in the glass tank, light will be bent at the interface of air and glass, glass and water. Based on binocular stereo vision and refraction principle, we establish a mathematical model of 3D image correlation to reconstruct the 3D coordinates of samples in the water. Marking speckle in fish surface, a series of real-time speckle images of swimming fish will be obtained by two high-speed cameras, and instantaneous 3D shape, strain, displacement etc. of fish will be reconstructed.

  3. Laminar cortical dynamics of 3D surface perception: stratification, transparency, and neon color spreading.

    PubMed

    Grossberg, Stephen; Yazdanbakhsh, Arash

    2005-06-01

    The 3D LAMINART neural model is developed to explain how the visual cortex gives rise to 3D percepts of stratification, transparency, and neon color spreading in response to 2D pictures and 3D scenes. Such percepts are sensitive to whether contiguous image regions have the same contrast polarity and ocularity. The model predicts how like-polarity competition at V1 simple cells in layer 4 may cause these percepts when it interacts with other boundary and surface processes in V1, V2, and V4. The model also explains how: the Metelli Rules cause transparent percepts, bistable transparency percepts arise, and attention influences transparency reversal.

  4. Parametric estimation of 3D tubular structures for diffuse optical tomography

    PubMed Central

    Larusson, Fridrik; Anderson, Pamela G.; Rosenberg, Elizabeth; Kilmer, Misha E.; Sassaroli, Angelo; Fantini, Sergio; Miller, Eric L.

    2013-01-01

    We explore the use of diffuse optical tomography (DOT) for the recovery of 3D tubular shapes representing vascular structures in breast tissue. Using a parametric level set method (PaLS) our method incorporates the connectedness of vascular structures in breast tissue to reconstruct shape and absorption values from severely limited data sets. The approach is based on a decomposition of the unknown structure into a series of two dimensional slices. Using a simplified physical model that ignores 3D effects of the complete structure, we develop a novel inter-slice regularization strategy to obtain global regularity. We report on simulated and experimental reconstructions using realistic optical contrasts where our method provides a more accurate estimate compared to an unregularized approach and a pixel based reconstruction. PMID:23411913

  5. Design and verification of diffractive optical elements for speckle generation of 3-D range sensors

    NASA Astrophysics Data System (ADS)

    Du, Pei-Qin; Shih, Hsi-Fu; Chen, Jenq-Shyong; Wang, Yi-Shiang

    2016-09-01

    The optical projection using speckles is one of the structured light methods that have been applied to three-dimensional (3-D) range sensors. This paper investigates the design and fabrication of diffractive optical elements (DOEs) for generating the light field with uniformly distributed speckles. Based on the principles of computer generated holograms, the iterative Fourier transform algorithm was adopted for the DOE design. It was used to calculate the phase map for diffracting the incident laser beam into a goal pattern with distributed speckles. Four patterns were designed in the study. Their phase maps were first examined by a spatial light modulator and then fabricated on glass substrates by microfabrication processes. Finally, the diffraction characteristics of the fabricated devices were verified. The experimental results show that the proposed methods are applicable to the DOE design of 3-D range sensors. Furthermore, any expected diffraction area and speckle density could be possibly achieved according to the relations presented in the paper.

  6. Computational optical-sectioning microscopy for 3D quantization of cell motion: results and challenges

    NASA Astrophysics Data System (ADS)

    McNally, James G.

    1994-09-01

    How cells move and navigate within a 3D tissue mass is of central importance in such diverse problems as embryonic development, wound healing and metastasis. This locomotion can now be visualized and quantified by using computation optical-sectioning microscopy. In this approach, a series of 2D images at different depths in a specimen are stacked to construct a 3D image, and then with a knowledge of the microscope's point-spread function, the actual distribution of fluorescent intensity in the specimen is estimated via computation. When coupled with wide-field optics and a cooled CCD camera, this approach permits non-destructive 3D imaging of living specimens over long time periods. With these techniques, we have observed a complex diversity of motile behaviors in a model embryonic system, the cellular slime mold Dictyostelium. To understand the mechanisms which control these various behaviors, we are examining motion in various Dictyostelium mutants with known defects in proteins thought to be essential for signal reception, cell-cell adhesion or locomotion. This application of computational techniques to analyze 3D cell locomotion raises several technical challenges. Image restoration techniques must be fast enough to process numerous 1 Gbyte time-lapse data sets (16 Mbytes per 3D image X 60 time points). Because some cells are weakly labeled and background intensity is often high due to unincorporated dye, the SNR in some of these images is poor. Currently, the images are processed by a regularized linear least- squares restoration method, and occasionally by a maximum-likelihood method. Also required for these studies are accurate automated- tracking procedures to generate both 3D trajectories for individual cells and 3D flows for a group of cells. Tracking is currently done independently for each cell, using a cell's image as a template to search for a similar image at the next time point. Finally, sophisticated visualization techniques are needed to view the

  7. Land surface temperature from INSAT-3D imager data: Retrieval and assimilation in NWP model

    NASA Astrophysics Data System (ADS)

    Singh, Randhir; Singh, Charu; Ojha, Satya P.; Kumar, A. Senthil; Kishtawal, C. M.; Kumar, A. S. Kiran

    2016-06-01

    A new algorithm is developed for retrieving the land surface temperature (LST) from the imager radiance observations on board geostationary operational Indian National Satellite (INSAT-3D). The algorithm is developed using the two thermal infrared channels (TIR1 10.3-11.3 µm and TIR2 11.5-12.5 µm) via genetic algorithm (GA). The transfer function that relates LST and thermal radiances is developed using radiative transfer model simulated database. The developed algorithm has been applied on the INSAT-3D observed radiances, and LST retrieved from the developed algorithm has been validated with Moderate Resolution Imaging Spectroradiometer land surface temperature (LST) product. The developed algorithm demonstrates a good accuracy, without significant bias and standard deviations of 1.78 K and 1.41 K during daytime and nighttime, respectively. The newly proposed algorithm performs better than the operational algorithm used for LST retrieval from INSAT-3D satellite. Further, a set of data assimilation experiments is conducted with the Weather Research and Forecasting (WRF) model to assess the impact of INSAT-3D LST on model forecast skill over the Indian region. The assimilation experiments demonstrated a positive impact of the assimilated INSAT-3D LST, particularly on the lower tropospheric temperature and moisture forecasts. The temperature and moisture forecast errors are reduced (as large as 8-10%) with the assimilation of INSAT-3D LST, when compared to forecasts that were obtained without the assimilation of INSAT-3D LST. Results of the additional experiments of comparative performance of two LST products, retrieved from operational and newly proposed algorithms, indicate that the impact of INSAT-3D LST retrieved using newly proposed algorithm is significantly larger compared to the impact of INSAT-3D LST retrieved using operational algorithm.

  8. 3D printed sensing patches with embedded polymer optical fibre Bragg gratings

    NASA Astrophysics Data System (ADS)

    Zubel, Michal G.; Sugden, Kate; Saez-Rodriguez, D.; Nielsen, K.; Bang, O.

    2016-05-01

    The first demonstration of a polymer optical fibre Bragg grating (POFBG) embedded in a 3-D printed structure is reported. Its cyclic strain performance and temperature characteristics are examined and discussed. The sensing patch has a repeatable strain sensitivity of 0.38 pm/μepsilon. Its temperature behaviour is unstable, with temperature sensitivity values varying between 30-40 pm/°C.

  9. Imaging and 3-D dosimetry: top tips for MRI and optical CT

    NASA Astrophysics Data System (ADS)

    Doran, Simon J.

    2010-11-01

    The conference "refresher session" associated with this abstract reviews the main principles of the two most important imaging readout modalities for 3-D dosimetry: MRI and optical CT. Best practices for both these techniques are already described in several different places in the literature, but, for the uninitiated, there are a number of pitfalls. Here, I list some of the important considerations required to obtain good results from these methods and point to relevant prior work.

  10. Rapid fabrication of complex 3D extracellular microenvironments by dynamic optical projection stereolithography.

    PubMed

    Zhang, A Ping; Qu, Xin; Soman, Pranav; Hribar, Kolin C; Lee, Jin W; Chen, Shaochen; He, Sailing

    2012-08-16

    The topographic features of the extracelluar matrix (ECM) lay the foundation for cellular behavior. A novel biofabrication method using a digital-mirror device (DMD), called dynamic optical projection stereolithography (DOPsL) is demonstrated. This robust and versatile platform can generate complex biomimetic scaffolds within seconds. Such 3D scaffolds have promising potentials for studying cell interactions with microenvironments in vitro and in vivo.

  11. Fast 3D optical reconstruction in turbid media using spatially modulated light

    PubMed Central

    D’Andrea, Cosimo; Ducros, Nicolas; Bassi, Andrea; Arridge, Simon; Valentini, Gianluca

    2010-01-01

    A method to perform fast 3-D optical reconstruction, based on structured light, in thick samples is demonstrated and experimentally validated. The experimental and reconstruction procedure, based on Finite Elements Method, used to reconstruct absorbing heterogeneities, with arbitrary arrangement in space, is discussed. In particular we demonstrated that a 2D sampling of the source Fourier plane is required to improve the imaging capability. PMID:21258482

  12. Constructing topologically connected surfaces for the comprehensive analysis of 3-D medical structures

    NASA Astrophysics Data System (ADS)

    Kalvin, Alan D.; Cutting, Court B.; Haddad, Betsy; Noz, Marilyn E.

    1991-06-01

    Three-dimensional (3D) medical imaging deals with the visualization, manipulation, and measuring of objects in 3D medical images. So far, research efforts have concentrated primarily on visualization, using well-developed methods from computer graphics. Very little has been achieved in developing techniques for manipulating medical objects, or for extracting quantitative measurements from them beyond volume calculation (by counting voxels), and computing distances and angles between manually located surface points. A major reason for the slow pace in the development of manipulation and quantification methods lies with the limitations of current algorithms for constructing surfaces from 3D solid objects. We show that current surface construction algorithms either (a) do not construct valid surface descriptions of solid objects or (b) produce surface representations that are not particularly suitable for anything other than visualization. We present ALLIGATOR, a new surface construction algorithm that produces valid, topologically connected surface representations of solid objects. We have developed a modeling system based on the surface representations created by ALLIGATOR that is suitable for developing algorithms to visualize, manipulate, and quantify 3D medical objects. Using this modeling system we have developed a method for efficiently computing principle curvatures and directions on surfaces. These measurements form the basis for a new metric system being developed for morphometrics. The modeling system is also being used in the development of systems for quantitative pre-surgical planning and surgical augmentation.

  13. Performance of a commercial optical CT scanner and polymer gel dosimeters for 3-D dose verification

    SciTech Connect

    Xu, Y.; Wuu, C.-S.; Maryanski, Marek J.

    2004-11-01

    Performance analysis of a commercial three-dimensional (3-D) dose mapping system based on optical CT scanning of polymer gels is presented. The system consists of BANG{sup reg}3 polymer gels (MGS Research, Inc., Madison, CT), OCTOPUS{sup TM} laser CT scanner (MGS Research, Inc., Madison, CT), and an in-house developed software for optical CT image reconstruction and 3-D dose distribution comparison between the gel, film measurements and the radiation therapy treatment plans. Various sources of image noise (digitization, electronic, optical, and mechanical) generated by the scanner as well as optical uniformity of the polymer gel are analyzed. The performance of the scanner is further evaluated in terms of the reproducibility of the data acquisition process, the uncertainties at different levels of reconstructed optical density per unit length and the effects of scanning parameters. It is demonstrated that for BANG{sup registered}3 gel phantoms held in cylindrical plastic containers, the relative dose distribution can be reproduced by the scanner with an overall uncertainty of about 3% within approximately 75% of the radius of the container. In regions located closer to the container wall, however, the scanner generates erroneous optical density values that arise from the reflection and refraction of the laser rays at the interface between the gel and the container. The analysis of the accuracy of the polymer gel dosimeter is exemplified by the comparison of the gel/OCT-derived dose distributions with those from film measurements and a commercial treatment planning system (Cadplan, Varian Corporation, Palo Alto, CA) for a 6 cmx6 cm single field of 6 MV x rays and a 3-D conformal radiotherapy (3DCRT) plan. The gel measurements agree with the treatment plans and the film measurements within the '3%-or-2 mm' criterion throughout the usable, artifact-free central region of the gel volume. Discrepancies among the three data sets are analyzed.

  14. Automated generation of NC part programs for excimer laser ablation micromachining from known 3D surfaces

    NASA Astrophysics Data System (ADS)

    Mutapcic, Emir; Iovenitti, Pio G.; Hayes, Jason P.

    2002-11-01

    The purpose of this research project is to improve the capability of the laser micromachinning process, so that any desired 3D surface can be produced by taking the 3D information from a CAD system and automatically generating the NC part programs. In addition, surface quality should be able to be controlled by specifying optimised parameters. This paper presents the algorithms and a software system, which processes 3D geometry in an STL file format from a CAD system and produces the NC part program to mill the surface using the Excimer laser ablation process. Simple structures are used to demonstrate the prototype system's part programming capabilities, and an actual surface is machined.

  15. Characterization of a parallel beam CCD optical-CT apparatus for 3D radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Krstajić, Nikola; Doran, Simon J.

    2006-12-01

    This paper describes the initial steps we have taken in establishing CCD based optical-CT as a viable alternative for 3-D radiation dosimetry. First, we compare the optical density (OD) measurements from a high quality test target and variable neutral density filter (VNDF). A modulation transfer function (MTF) of individual projections is derived for three positions of the sinusoidal test target within the scanning tank. Our CCD is then characterized in terms of its signal-to-noise ratio (SNR). Finally, a sample reconstruction of a scan of a PRESAGETM (registered trademark of Heuris Pharma, NJ, Skillman, USA.) dosimeter is given, demonstrating the capabilities of the apparatus.

  16. 3-D Surface Depression Profiling Using High Frequency Focused Air-Coupled Ultrasonic Pulses

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Kautz, Harold E.; Abel, Phillip B.; Whalen, Mike F.; Hendricks, J. Lynne; Bodis, James R.

    1999-01-01

    Surface topography is an important variable in the performance of many industrial components and is normally measured with diamond-tip profilometry over a small area or using optical scattering methods for larger area measurement. This article shows quantitative surface topography profiles as obtained using only high-frequency focused air-coupled ultrasonic pulses. The profiles were obtained using a profiling system developed by NASA Glenn Research Center and Sonix, Inc (via a formal cooperative agreement). (The air transducers are available as off-the-shelf items from several companies.) The method is simple and reproducible because it relies mainly on knowledge and constancy of the sound velocity through the air. The air transducer is scanned across the surface and sends pulses to the sample surface where they are reflected back from the surface along the same path as the incident wave. Time-of-flight images of the sample surface are acquired and converted to depth/surface profile images using the simple relation (d = V*t/2) between distance (d), time-of-flight (t), and the velocity of sound in air (V). The system has the ability to resolve surface depression variations as small as 25 microns, is useable over a 1.4 mm vertical depth range, and can profile large areas only limited by the scan limits of the particular ultrasonic system. (Best-case depth resolution is 0.25 microns which may be achievable with improved isolation from vibration and air currents.) The method using an optimized configuration is reasonably rapid and has all quantitative analysis facilities on-line including 2-D and 3-D visualization capability, extreme value filtering (for faulty data), and leveling capability. Air-coupled surface profilometry is applicable to plate-like and curved samples. In this article, results are shown for several proof-of-concept samples, plastic samples burned in microgravity on the STS-54 space shuttle mission, and a partially-coated cylindrical ceramic

  17. A joint estimation detection of Glaucoma progression in 3D spectral domain optical coherence tomography optic nerve head images

    NASA Astrophysics Data System (ADS)

    Belghith, Akram; Bowd, Christopher; Weinreb, Robert N.; Zangwill, Linda M.

    2014-03-01

    Glaucoma is an ocular disease characterized by distinctive changes in the optic nerve head (ONH) and visual field. Glaucoma can strike without symptoms and causes blindness if it remains without treatment. Therefore, early disease detection is important so that treatment can be initiated and blindness prevented. In this context, important advances in technology for non-invasive imaging of the eye have been made providing quantitative tools to measure structural changes in ONH topography, an essential element for glaucoma detection and monitoring. 3D spectral domain optical coherence tomography (SD-OCT), an optical imaging technique, has been commonly used to discriminate glaucomatous from healthy subjects. In this paper, we present a new framework for detection of glaucoma progression using 3D SD-OCT images. In contrast to previous works that the retinal nerve fiber layer (RNFL) thickness measurement provided by commercially available spectral-domain optical coherence tomograph, we consider the whole 3D volume for change detection. To integrate a priori knowledge and in particular the spatial voxel dependency in the change detection map, we propose the use of the Markov Random Field to handle a such dependency. To accommodate the presence of false positive detection, the estimated change detection map is then used to classify a 3D SDOCT image into the "non-progressing" and "progressing" glaucoma classes, based on a fuzzy logic classifier. We compared the diagnostic performance of the proposed framework to existing methods of progression detection.

  18. A novel 3D stitching method for WLI based large range surface topography measurement

    NASA Astrophysics Data System (ADS)

    Lei, Zili; Liu, Xiaojun; Zhao, Li; Chen, Liangzhou; Li, Qian; Yuan, Tengfei; Lu, Wenlong

    2016-01-01

    3D image stitching is an important technique for large range surface topography measurement in White-Light Interferometry (WLI). However, the stitching accuracy is inevitably influenced by noise. To solve this problem, a novel method for 3D image stitching is proposed in this paper. In this method, based on noise mechanism analysis in WLI measurement, a new definition of noise in 3D image is given by an evaluation model for difference between the practical WLI interference signal and the ideal signal. By this new definition, actual noises in 3D image are identified while those practical singular heights on surface will not be wrongly attributed to noise. With the definition, a binary matrix for noise mark corresponding to 3D image is obtained. Then, the matrix is devoted, as an important component, to establish a series of new algorithms of capability for suppressing the adverse effects of noises in each process of the proposed stitching method. By this method, the influence of the noises on stitching is substantially reduced and the stitching accuracy is improved. Through 3D image stitching experiments with noises in WLI, effectiveness of the proposed method is verified.

  19. A novel method for fabricating curved frequency selective surface via 3D printing technology

    NASA Astrophysics Data System (ADS)

    Liang, Fengchao; Gao, Jinsong

    2014-12-01

    A novel method for fabricating curved frequency selective surfaces with undevelopable curved shape using 3D printing technology was proposed in this paper. First, FSS composed of Y slotted elements that adapt to 0° ~ 70 ° incidences was designed. Then, the 3D model of the curved FSS was created in a 3D modeling software. Next, the 3D model was digitalized into stl format file and then the stl file was inputted into a stereo lithography 3D printer. Next, the prototype of the curved FSS was fabricated by the 3D printer layer by layer. Finally, a 10 μm thick aluminum film was coated on the outer surface of the prototype of the curved FSS by a vacuum coater. The transmission performance of the metallised curved FSS was tested using free space method. It was shown that frequency selection characteristic of the metallised curved FSS reached the requirements of simulation design. The pass-band was in the Ku-band and the transmission rate on center frequency was 63% for nose cone incident direction. This method provides a new way to apply the FSS to arbitrary curved electromagnetic window.

  20. Development of 3D PPF/DEF scaffolds using micro-stereolithography and surface modification.

    PubMed

    Lan, Phung Xuan; Lee, Jin Woo; Seol, Young-Joon; Cho, Dong-Woo

    2009-01-01

    Poly(propylene fumarate) (PPF) is an ultraviolet-curable and biodegradable polymer with potential applications for bone regeneration. In this study, we designed and fabricated three-dimensional (3D) porous scaffolds based on a PPF polymer network using micro-stereolithography (MSTL). The 3D scaffold was well fabricated with a highly interconnected porous structure and porosity of 65%. These results provide a new scaffold fabrication method for tissue engineering. Surface modification is a commonly used and effective method for improving the surface characteristics of biomaterials without altering their bulk properties that avoids the expense and long time associated with the development of new biomaterials. Therefore, we examined surface modification of 3D scaffolds by applying accelerated biomimetic apatite and arginine-glycine-aspartic acid (RGD) peptide coating to promote cell behavior. The apatite coating uniformly covered the scaffold surface after immersion for 24 h in 5-fold simulated body fluid (5SBF) and then the RGD peptide was applied. Finally, the coated 3D scaffolds were seeded with MC3T3-E1 pre-osteoblasts and their biologic properties were evaluated using an MTS assay and histologic staining. We found that 3D PPF/diethyl fumarate (DEF) scaffolds fabricated with MSTL and biomimetic apatite coating can be potentially used in bone tissue engineering.

  1. A continuous surface reconstruction method on point cloud captured from a 3D surface photogrammetry system

    SciTech Connect

    Liu, Wenyang; Cheung, Yam; Sabouri, Pouya; Arai, Tatsuya J.; Sawant, Amit; Ruan, Dan

    2015-11-15

    achieved submillimeter reconstruction RMSE under different configurations, demonstrating quantitatively the faith of the proposed method in preserving local structural properties of the underlying surface in the presence of noise and missing measurements, and its robustness toward variations of such characteristics. On point clouds from the human subject, the proposed method successfully reconstructed all patient surfaces, filling regions where raw point coordinate readings were missing. Within two comparable regions of interest in the chest area, similar mean curvature distributions were acquired from both their reconstructed surface and CT surface, with mean and standard deviation of (μ{sub recon} = − 2.7 × 10{sup −3} mm{sup −1}, σ{sub recon} = 7.0 × 10{sup −3} mm{sup −1}) and (μ{sub CT} = − 2.5 × 10{sup −3} mm{sup −1}, σ{sub CT} = 5.3 × 10{sup −3} mm{sup −1}), respectively. The agreement of local geometry properties between the reconstructed surfaces and the CT surface demonstrated the ability of the proposed method in faithfully representing the underlying patient surface. Conclusions: The authors have integrated and developed an accurate level-set based continuous surface reconstruction method on point clouds acquired by a 3D surface photogrammetry system. The proposed method has generated a continuous representation of the underlying phantom and patient surfaces with good robustness against noise and missing measurements. It serves as an important first step for further development of motion tracking methods during radiotherapy.

  2. The 3D manipulation of a microsphere for nano-CMM probe using single fiber optical trapping

    NASA Astrophysics Data System (ADS)

    Eom, Sang In; Takaya, Yasuhiro; Miyoshi, Takashi; Hayashi, Terutake

    2006-08-01

    We suggest a novel 3-D probing technique for measuring micro parts which have high aspect ratio such as a groove or a deep-hole. This technique uses the optical force exerted on a dielectric microsphere at the tip of optical fiber so called the fiber optical trapping. A microsphere is trapped at the tip of an optical fiber which has micrometer size of the diameter and sub micrometer size of the tapered tip. The optical source is a Nd:YAG laser with the wavelength of 1064 nm. A fiber optical trapping system is quite similar to a conventional CMM. The roll of a microsphere is the same as the probe sphere of a conventional CMM and an optical fiber works as a stylus shaft. The micro optical fiber part is thinner than the diameter of the microsphere and longer than the depth of shapes such as deep holes and grooves, which enable to make an approach to a steep angle surface of a work piece with high aspect ratio.

  3. Numerical Investigation of 3D multichannel analysis of surface wave method

    NASA Astrophysics Data System (ADS)

    Wang, Limin; Xu, Yixian; Luo, Yinhe

    2015-08-01

    Multichannel analysis of surface wave (MASW) method is an efficient tool to obtain near-surface S-wave velocity, and it has gained popularity in engineering practice. Up to now, most examples of using the MASW technique are focused on 2D models or data from a 1D linear receiver spread. We propose a 3D MASW scheme. A finite-difference (FD) method is used to investigate the method using linear and fan-shaped receiver spreads. Results show that the 3D topography strongly affects propagation of Rayleigh waves. The energy concentration of dispersion image is distorted and bifurcated because of the influence of free-surface topography. These effects are reduced with the 3D MASW method. Lastly we investigate the relation between the array size and the resolution of dispersion measurement.

  4. Characterizing the influence of surface roughness and inclination on 3D vision sensor performance

    NASA Astrophysics Data System (ADS)

    Hodgson, John R.; Kinnell, Peter; Justham, Laura; Jackson, Michael R.

    2015-12-01

    This paper reports a methodology to evaluate the performance of 3D scanners, focusing on the influence of surface roughness and inclination on the number of acquired data points and measurement noise. Point clouds were captured of samples mounted on a robotic pan-tilt stage using an Ensenso active stereo 3D scanner. The samples have isotropic texture and range in surface roughness (Ra) from 0.09 to 0.46 μm. By extracting the point cloud quality indicators, point density and standard deviation, at a multitude of inclinations, maps of scanner performance are created. These maps highlight the performance envelopes of the sensor, the aim being to predict and compare scanner performance on real-world surfaces, rather than idealistic artifacts. The results highlight the need to characterize 3D vision sensors by their measurement limits as well as best-case performance, determined either by theoretical calculation or measurements in ideal circumstances.

  5. 3D numerical simulation analysis of passive drag near free surface in swimming

    NASA Astrophysics Data System (ADS)

    Zhan, Jie-min; Li, Tian-zeng; Chen, Xue-bin; Li, Yok-sheung; Wai, Wing-hong Onyx

    2015-04-01

    The aim of this work is to build a 3D numerical model to study the characteristics of passive drag on competitive swimmers taking into account the impact of the free surface. This model solves the 3D incompressible Navier-Stokes equations using RNG k- ɛ turbulence closure. The volume of fluid (VOF) method is used to locate the free surface. The 3D virtual model is created by Computer Aided Industrial Design (CAID) software, Rhinoceros. Firstly, a specific posture of swimming is studied. The simulation results are in good agreement with the data from mannequin towing experiments. The effects of a swimmer's arms and legs positions on swimming performance are then studied. Finally, it is demonstrated that the present method is capable of simulating gliding near the free surface.

  6. Stereoscopic 3D display with dynamic optical correction for recovering from asthenopia

    NASA Astrophysics Data System (ADS)

    Shibata, Takashi; Kawai, Takashi; Otsuki, Masaki; Miyake, Nobuyuki; Yoshihara, Yoshihiro; Iwasaki, Tsuneto

    2005-03-01

    The purpose of this study was to consider a practical application of a newly developed stereoscopic 3-D display that solves the problem of discrepancy between accommodation and convergence. The display uses dynamic optical correction to reduce the discrepancy, and can present images as if they are actually remote objects. The authors thought the display may assist in recovery from asthenopia, which is often caused when the eyes focus on a nearby object for a long time, such as in VDT (Visual Display Terminal) work. In general, recovery from asthenopia, and especially accommodative asthenopia, is achieved by focusing on distant objects. In order to verify this hypothesis, the authors performed visual acuity tests using Landolt rings before and after presenting stereoscopic 3-D images, and evaluated the degree of recovery from asthenopia. The experiment led to three main conclusions: (1) Visual acuity rose after viewing stereoscopic 3-D images on the developed display. (2) Recovery from asthenopia was particularly effective for the dominant eye in comparison with the other eye. (3) Interviews with the subjects indicated that the Landolt rings were particularly clear after viewing the stereoscopic 3-D images.

  7. Examination of asthenopia recovery using stereoscopic 3D display with dynamic optical correction

    NASA Astrophysics Data System (ADS)

    Shibata, Takashi; Kawai, Takashi; Ohta, Keiji; Lee, JaeLin; Otsuki, Masaki; Miyake, Nobuyuki; Yoshihara, Yoshihiro; Iwasaki, Tsuneto

    2006-02-01

    A common cause of asthenopia is viewing objects from a short distance, as is the case when working at a VDT (Visual Display Terminal). In general, recovery from asthenopia, especially accommodative asthenopia, is aided by looking into the distance. The authors have developed a stereoscopic 3-D display with dynamic optical correction that may reduce asthenopia. The display does this by reducing the discrepancy between accommodation and convergence, thereby presenting images as if they were actually in the distance. The results of visual acuity tests given before and after presenting stereoscopic 3-D images with this display show a tendency towards less asthenopia. In this study, the authors developed a refraction feedback function that makes the viewer's distance vision more effective when viewing stereoscopic 3-D images on the this display. Using this function, refraction is fed back during viewing and the viewer gradually acquires distance vision. The results of the study suggest that stereoscopic 3-D images are more effective than 2-D images for recovery from asthenopia.

  8. A comprehensive evaluation of the PRESAGE∕optical-CT 3D dosimetry system

    PubMed Central

    Sakhalkar, H. S.; Adamovics, J.; Ibbott, G.; Oldham, M.

    2009-01-01

    This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco-dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical-CT scanner (OCTOPUS 5× scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head-and-neck (H&N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields (1×3 cm2) impinging on the flat circular face of the dosimeter. A repetitious sequence of three dose levels (4, 2.88, and 1.28 Gy) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS 5× commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to ∼2%) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference, 1 mm distance-to-agreement criteria indicating excellent intradosimeter uniformity even at low dose levels. Postirradiation, the dosimeters were all found to exhibit a slight increase in opaqueness

  9. A comprehensive evaluation of the PRESAGE/optical-CT 3D dosimetry system.

    PubMed

    Sakhalkar, H S; Adamovics, J; Ibbott, G; Oldham, M

    2009-01-01

    This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco-dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical-CT scanner (OCTOPUS 5x scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head-and-neck (H&N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields (1 x 3 cm2) impinging on the flat circular face of the dosimeter. A repetitious sequence of three dose levels (4, 2.88, and 1.28 Gy) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS 5x commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to approximately 2%) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference, 1 mm distance-to-agreement criteria indicating excellent intradosimeter uniformity even at low dose levels. Postirradiation, the dosimeters were all found to exhibit a slight increase in

  10. A comprehensive evaluation of the PRESAGE/optical-CT 3D dosimetry system

    SciTech Connect

    Sakhalkar, H. S.; Adamovics, J.; Ibbott, G.; Oldham, M.

    2009-01-15

    This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco-dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical-CT scanner (OCTOPUS 5x scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head-and-neck (H and N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields (1x3 cm{sup 2}) impinging on the flat circular face of the dosimeter. A repetitious sequence of three dose levels (4, 2.88, and 1.28 Gy) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS 5x commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to {approx}2%) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference, 1 mm distance-to-agreement criteria indicating excellent intradosimeter uniformity even at low dose levels. Postirradiation, the dosimeters were all found to exhibit a slight increase in

  11. surf3d: A 3-D finite-element program for the analysis of surface and corner cracks in solids subjected to mode-1 loadings

    NASA Technical Reports Server (NTRS)

    Raju, I. S.; Newman, J. C., Jr.

    1993-01-01

    A computer program, surf3d, that uses the 3D finite-element method to calculate the stress-intensity factors for surface, corner, and embedded cracks in finite-thickness plates with and without circular holes, was developed. The cracks are assumed to be either elliptic or part eliptic in shape. The computer program uses eight-noded hexahedral elements to model the solid. The program uses a skyline storage and solver. The stress-intensity factors are evaluated using the force method, the crack-opening displacement method, and the 3-D virtual crack closure methods. In the manual the input to and the output of the surf3d program are described. This manual also demonstrates the use of the program and describes the calculation of the stress-intensity factors. Several examples with sample data files are included with the manual. To facilitate modeling of the user's crack configuration and loading, a companion program (a preprocessor program) that generates the data for the surf3d called gensurf was also developed. The gensurf program is a three dimensional mesh generator program that requires minimal input and that builds a complete data file for surf3d. The program surf3d is operational on Unix machines such as CRAY Y-MP, CRAY-2, and Convex C-220.

  12. Machining Error Compensation Based on 3D Surface Model Modified by Measured Accuracy

    NASA Astrophysics Data System (ADS)

    Abe, Go; Aritoshi, Masatoshi; Tomita, Tomoki; Shirase, Keiichi

    Recently, a demand for precision machining of dies and molds with complex shapes has been increasing. Although CNC machine tools are utilized widely for machining, still machining error compensation is required to meet the increasing demand of machining accuracy. However, the machining error compensation is an operation which takes huge amount of skill, time and cost. This paper deals with a new method of the machining error compensation. The 3D surface data of the machined part is modified according to the machining error measured by CMM (Coordinate Measuring Machine). A compensated NC program is generated from the modified 3D surface data for the machining error compensation.

  13. Changes in quantitative 3D shape features of the optic nerve head associated with age

    NASA Astrophysics Data System (ADS)

    Christopher, Mark; Tang, Li; Fingert, John H.; Scheetz, Todd E.; Abramoff, Michael D.

    2013-02-01

    Optic nerve head (ONH) structure is an important biological feature of the eye used by clinicians to diagnose and monitor progression of diseases such as glaucoma. ONH structure is commonly examined using stereo fundus imaging or optical coherence tomography. Stereo fundus imaging provides stereo views of the ONH that retain 3D information useful for characterizing structure. In order to quantify 3D ONH structure, we applied a stereo correspondence algorithm to a set of stereo fundus images. Using these quantitative 3D ONH structure measurements, eigen structures were derived using principal component analysis from stereo images of 565 subjects from the Ocular Hypertension Treatment Study (OHTS). To evaluate the usefulness of the eigen structures, we explored associations with the demographic variables age, gender, and race. Using regression analysis, the eigen structures were found to have significant (p < 0.05) associations with both age and race after Bonferroni correction. In addition, classifiers were constructed to predict the demographic variables based solely on the eigen structures. These classifiers achieved an area under receiver operating characteristic curve of 0.62 in predicting a binary age variable, 0.52 in predicting gender, and 0.67 in predicting race. The use of objective, quantitative features or eigen structures can reveal hidden relationships between ONH structure and demographics. The use of these features could similarly allow specific aspects of ONH structure to be isolated and associated with the diagnosis of glaucoma, disease progression and outcomes, and genetic factors.

  14. Automated 3D Damaged Cavity Model Builder for Lower Surface Acreage Tile on Orbiter

    NASA Technical Reports Server (NTRS)

    Belknap, Shannon; Zhang, Michael

    2013-01-01

    The 3D Automated Thermal Tool for Damaged Acreage Tile Math Model builder was developed to perform quickly and accurately 3D thermal analyses on damaged lower surface acreage tiles and structures beneath the damaged locations on a Space Shuttle Orbiter. The 3D model builder created both TRASYS geometric math models (GMMs) and SINDA thermal math models (TMMs) to simulate an idealized damaged cavity in the damaged tile(s). The GMMs are processed in TRASYS to generate radiation conductors between the surfaces in the cavity. The radiation conductors are inserted into the TMMs, which are processed in SINDA to generate temperature histories for all of the nodes on each layer of the TMM. The invention allows a thermal analyst to create quickly and accurately a 3D model of a damaged lower surface tile on the orbiter. The 3D model builder can generate a GMM and the correspond ing TMM in one or two minutes, with the damaged cavity included in the tile material. A separate program creates a configuration file, which would take a couple of minutes to edit. This configuration file is read by the model builder program to determine the location of the damage, the correct tile type, tile thickness, structure thickness, and SIP thickness of the damage, so that the model builder program can build an accurate model at the specified location. Once the models are built, they are processed by the TRASYS and SINDA.

  15. 3D surface reconstruction and visualization of the Drosophila wing imaginal disc at cellular resolution

    NASA Astrophysics Data System (ADS)

    Bai, Linge; Widmann, Thomas; Jülicher, Frank; Dahmann, Christian; Breen, David

    2013-01-01

    Quantifying and visualizing the shape of developing biological tissues provide information about the morphogenetic processes in multicellular organisms. The size and shape of biological tissues depend on the number, size, shape, and arrangement of the constituting cells. To better understand the mechanisms that guide tissues into their final shape, it is important to investigate the cellular arrangement within tissues. Here we present a data processing pipeline to generate 3D volumetric surface models of epithelial tissues, as well as geometric descriptions of the tissues' apical cell cross-sections. The data processing pipeline includes image acquisition, editing, processing and analysis, 2D cell mesh generation, 3D contourbased surface reconstruction, cell mesh projection, followed by geometric calculations and color-based visualization of morphological parameters. In their first utilization we have applied these procedures to construct a 3D volumetric surface model at cellular resolution of the wing imaginal disc of Drosophila melanogaster. The ultimate goal of the reported effort is to produce tools for the creation of detailed 3D geometric models of the individual cells in epithelial tissues. To date, 3D volumetric surface models of the whole wing imaginal disc have been created, and the apicolateral cell boundaries have been identified, allowing for the calculation and visualization of cell parameters, e.g. apical cross-sectional area of cells. The calculation and visualization of morphological parameters show position-dependent patterns of cell shape in the wing imaginal disc. Our procedures should offer a general data processing pipeline for the construction of 3D volumetric surface models of a wide variety of epithelial tissues.

  16. Development of scanning laser sensor for underwater 3D imaging with the coaxial optics

    NASA Astrophysics Data System (ADS)

    Ochimizu, Hideaki; Imaki, Masaharu; Kameyama, Shumpei; Saito, Takashi; Ishibashi, Shoujirou; Yoshida, Hiroshi

    2014-06-01

    We have developed the scanning laser sensor for underwater 3-D imaging which has the wide scanning angle of 120º (Horizontal) x 30º (Vertical) with the compact size of 25 cm diameter and 60 cm long. Our system has a dome lens and a coaxial optics to realize both the wide scanning angle and the compactness. The system also has the feature in the sensitivity time control (STC) circuit, in which the receiving gain is increased according to the time of flight. The STC circuit contributes to detect a small signal by suppressing the unwanted signals backscattered by marine snows. We demonstrated the system performance in the pool, and confirmed the 3-D imaging with the distance of 20 m. Furthermore, the system was mounted on the autonomous underwater vehicle (AUV), and demonstrated the seafloor mapping at the depth of 100 m in the ocean.

  17. Optical absorption enhancement in 3D nanofibers coated on polymer substrate for photovoltaic devices.

    PubMed

    Kiani, Amirkianoosh; Venkatakrishnan, Krishnan; Tan, Bo

    2015-06-01

    Recent research in the field of photovoltaics has shown that polymer solar cells have great potential to provide low-cost, lightweight and flexible electronic devices to harvest solar energy. In this paper, we propose a new method for the generation of three-dimensional nanofibers coated on polymer substrate induced by femtosecond laser pulses. In this new method, a thin layer of polymer is irradiated by megahertz femtosecond laser pulses under ambient conditions, and a thin fibrous layer is generated on top of the polymer substrate. This method is single step; no additional materials are added, and the layers of the three-dimensional (3D) polymer nanofibrous structures are grown on top of the substrate after laser irradiation. Light spectroscopy results show significant enhancement of light absorption in the generated 3D nanofibrous layers of polymer. Finally, we suggest how to maximize the light trapping and optical absorption of the generated nanofiber cells by optimizing the laser parameters. PMID:26072881

  18. 3D scanning electron microscopy applied to surface characterization of fluorosed dental enamel.

    PubMed

    Limandri, Silvina; Galván Josa, Víctor; Valentinuzzi, María Cecilia; Chena, María Emilia; Castellano, Gustavo

    2016-05-01

    The enamel surfaces of fluorotic teeth were studied by scanning electron stereomicroscopy. Different whitening treatments were applied to 25 pieces to remove stains caused by fluorosis and their surfaces were characterized by stereomicroscopy in order to obtain functional and amplitude parameters. The topographic features resulting for each treatment were determined through these parameters. The results obtained show that the 3D reconstruction achieved from the SEM stereo pairs is a valuable potential alternative for the surface characterization of this kind of samples.

  19. Intrathoracic tumour motion estimation from CT imaging using the 3D optical flow method

    NASA Astrophysics Data System (ADS)

    Guerrero, Thomas; Zhang, Geoffrey; Huang, Tzung-Chi; Lin, Kang-Ping

    2004-09-01

    The purpose of this work was to develop and validate an automated method for intrathoracic tumour motion estimation from breath-hold computed tomography (BH CT) imaging using the three-dimensional optical flow method (3D OFM). A modified 3D OFM algorithm provided 3D displacement vectors for each voxel which were used to map tumour voxels on expiration BH CT onto inspiration BH CT images. A thoracic phantom and simulated expiration/inspiration BH CT pairs were used for validation. The 3D OFM was applied to the measured inspiration and expiration BH CT images from one lung cancer and one oesophageal cancer patient. The resulting displacements were plotted in histogram format and analysed to provide insight regarding the tumour motion. The phantom tumour displacement was measured as 1.20 and 2.40 cm with full-width at tenth maximum (FWTM) for the distribution of displacement estimates of 0.008 and 0.006 cm, respectively. The maximum error of any single voxel's motion estimate was 1.1 mm along the z-dimension or approximately one-third of the z-dimension voxel size. The simulated BH CT pairs revealed an rms error of less than 0.25 mm. The displacement of the oesophageal tumours was nonuniform and up to 1.4 cm, this was a new finding. A lung tumour maximum displacement of 2.4 cm was found in the case evaluated. In conclusion, 3D OFM provided an accurate estimation of intrathoracic tumour motion, with estimated errors less than the voxel dimension in a simulated motion phantom study. Surprisingly, oesophageal tumour motion was large and nonuniform, with greatest motion occurring at the gastro-oesophageal junction. Presented at The IASTED Second International Conference on Biomedical Engineering (BioMED 2004), Innsbruck, Austria, 16-18 February 2004.

  20. Three-Axis Distributed Fiber Optic Strain Measurement in 3D Woven Composite Structures

    NASA Technical Reports Server (NTRS)

    Castellucci, Matt; Klute, Sandra; Lally, Evan M.; Froggatt, Mark E.; Lowry, David

    2013-01-01

    Recent advancements in composite materials technologies have broken further from traditional designs and require advanced instrumentation and analysis capabilities. Success or failure is highly dependent on design analysis and manufacturing processes. By monitoring smart structures throughout manufacturing and service life, residual and operational stresses can be assessed and structural integrity maintained. Composite smart structures can be manufactured by integrating fiber optic sensors into existing composite materials processes such as ply layup, filament winding and three-dimensional weaving. In this work optical fiber was integrated into 3D woven composite parts at a commercial woven products manufacturing facility. The fiber was then used to monitor the structures during a VARTM manufacturing process, and subsequent static and dynamic testing. Low cost telecommunications-grade optical fiber acts as the sensor using a high resolution commercial Optical Frequency Domain Reflectometer (OFDR) system providing distributed strain measurement at spatial resolutions as low as 2mm. Strain measurements using the optical fiber sensors are correlated to resistive strain gage measurements during static structural loading. Keywords: fiber optic, distributed strain sensing, Rayleigh scatter, optical frequency domain reflectometry

  1. Modeling Images of Natural 3D Surfaces: Overview and Potential Applications

    NASA Technical Reports Server (NTRS)

    Jalobeanu, Andre; Kuehnel, Frank; Stutz, John

    2004-01-01

    Generative models of natural images have long been used in computer vision. However, since they only describe the of 2D scenes, they fail to capture all the properties of the underlying 3D world. Even though such models are sufficient for many vision tasks a 3D scene model is when it comes to inferring a 3D object or its characteristics. In this paper, we present such a generative model, incorporating both a multiscale surface prior model for surface geometry and reflectance, and an image formation process model based on realistic rendering, the computation of the posterior model parameter densities, and on the critical aspects of the rendering. We also how to efficiently invert the model within a Bayesian framework. We present a few potential applications, such as asteroid modeling and Planetary topography recovery, illustrated by promising results on real images.

  2. Generation of 3-D surface maps in waste storage silos using a structured light source

    NASA Technical Reports Server (NTRS)

    Burks, B. L.; Rowe, J. C.; Dinkins, M. A.; Christensen, B.; Selleck, C.; Jacoboski, D.; Markus, R.

    1992-01-01

    Surface contours inside the large waste storage tanks typical of the Department of Energy (DOE) complex are, in general, highly irregular. In addition to pipes and other pieces of equipment in the tanks, the surfaces may have features such as mounds, fissures, crystalline structures, and mixed solid and liquid forms. Prior to remediation activities, it will be necessary to characterize the waste to determine the most effective remediation approaches. Surface contour data will be required both prior to and during remediation. The use is described of a structured light source to generate 3-D surface contour maps of the interior of waste storage silos at the Feed Materials Production Center at Fernald, OH. The landscape inside these large waste storage tanks bears a strong resemblance to some of the landscapes that might be encountered during lunar or planetary exploration. Hence, these terrestrial 3-D mapping techniques may be directly applicable to extraterrestrial exploration. In further development, it will be demonstrated that these 3-D data can be used for robotic task planning just as 3-D surface contour data of a satellite could be used to plan maintenance tasks for a space-based servicing robot.

  3. 3D surface imaging for guidance in breast cancer radiotherapy: organs at risk

    NASA Astrophysics Data System (ADS)

    Alderliesten, Tanja; Betgen, Anja; van Vliet-Vroegindeweij, Corine; Remeijer, Peter

    2013-03-01

    Purpose: To evaluate the variability in heart position in deep-inspiration breath-hold (DIBH) radiotherapy for breast cancer when 3D surface imaging would be used for monitoring the depth of the breath hold during treatment. Materials and Methods: Ten patients who received DIBH radiotherapy after breast-conserving surgery (BCS) were included. Retrospectively, heart-based registrations were performed for cone-beam computed tomography (CBCT) to planning CT and breast surface registrations were performed for a 3D surface (two different regions of interest [ROIs]), captured concurrently with CBCT, to planning CT. The resulting setup errors were compared with linear regression analysis and receiver operating characteristic (ROC) analysis was performed to investigate the prediction quality of 3D surface imaging for 3D heart displacement. Further, the residual setup errors (systematic [Σ] and random [σ]) of the heart were estimated relative to the surface registrations. Results: When surface imaging [ROIleft-side;ROIboth-sides] would be used for monitoring, the residual errors of the heart position are in left-right: Σ=[0.360.12], σ=[0.160.14] cranio-caudal: Σ=[0.540.54], σ=[0.280.31] and in anteriorposterior: Σ=[0.180.14], σ=[0.200.19] cm. Correlations between setup errors were: R2 = [0.23;0.73], [0.67;0.65], [0.65;0.73] in left-right, cranio-caudal, and anterior-posterior direction, respectively. ROC analysis resulted in an area under the ROC curve of [0.82;0.78]. Conclusion: The use of ROIboth-sides provided promising results. However, considerable variability in the heart position, particularly in CC direction, is observed when 3D surface imaging would be used for guidance in DIBH radiotherapy after BCS. Planning organ at risk volume margins should be used to take into account the heart-position variability.

  4. 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.

  5. Controlled surface topography regulates collective 3D migration by epithelial-mesenchymal composite embryonic tissues.

    PubMed

    Song, Jiho; Shawky, Joseph H; Kim, YongTae; Hazar, Melis; LeDuc, Philip R; Sitti, Metin; Davidson, Lance A

    2015-07-01

    Cells in tissues encounter a range of physical cues as they migrate. Probing single cell and collective migratory responses to physically defined three-dimensional (3D) microenvironments and the factors that modulate those responses are critical to understanding how tissue migration is regulated during development, regeneration, and cancer. One key physical factor that regulates cell migration is topography. Most studies on surface topography and cell mechanics have been carried out with single migratory cells, yet little is known about the spreading and motility response of 3D complex multi-cellular tissues to topographical cues. Here, we examine the response to complex topographical cues of microsurgically isolated tissue explants composed of epithelial and mesenchymal cell layers from naturally 3D organized embryos of the aquatic frog Xenopus laevis. We control topography using fabricated micropost arrays (MPAs) and investigate the collective 3D migration of these multi-cellular systems in these MPAs. We find that the topography regulates both collective and individual cell migration and that dense MPAs reduce but do not eliminate tissue spreading. By modulating cell size through the cell cycle inhibitor Mitomycin C or the spacing of the MPAs we uncover how 3D topographical cues disrupt collective cell migration. We find surface topography can direct both single cell motility and tissue spreading, altering tissue-scale processes that enable efficient conversion of single cell motility into collective movement. PMID:25933063

  6. Controlled surface topography regulates collective 3D migration by epithelial-mesenchymal composite embryonic tissues.

    PubMed

    Song, Jiho; Shawky, Joseph H; Kim, YongTae; Hazar, Melis; LeDuc, Philip R; Sitti, Metin; Davidson, Lance A

    2015-07-01

    Cells in tissues encounter a range of physical cues as they migrate. Probing single cell and collective migratory responses to physically defined three-dimensional (3D) microenvironments and the factors that modulate those responses are critical to understanding how tissue migration is regulated during development, regeneration, and cancer. One key physical factor that regulates cell migration is topography. Most studies on surface topography and cell mechanics have been carried out with single migratory cells, yet little is known about the spreading and motility response of 3D complex multi-cellular tissues to topographical cues. Here, we examine the response to complex topographical cues of microsurgically isolated tissue explants composed of epithelial and mesenchymal cell layers from naturally 3D organized embryos of the aquatic frog Xenopus laevis. We control topography using fabricated micropost arrays (MPAs) and investigate the collective 3D migration of these multi-cellular systems in these MPAs. We find that the topography regulates both collective and individual cell migration and that dense MPAs reduce but do not eliminate tissue spreading. By modulating cell size through the cell cycle inhibitor Mitomycin C or the spacing of the MPAs we uncover how 3D topographical cues disrupt collective cell migration. We find surface topography can direct both single cell motility and tissue spreading, altering tissue-scale processes that enable efficient conversion of single cell motility into collective movement.

  7. Controlled Surface Topography regulates Collective 3D Migration by Epithelial-Mesenchymal Composite Embryonic Tissues

    PubMed Central

    Song, Jiho; Shawky, Joseph H.; Kim, YongTae; Hazar, Melis; LeDuc, Philip R.; Sitti, Metin; Davidson, Lance A.

    2015-01-01

    Cells in tissues encounter a range of physical cues as they migrate. Probing single cell and collective migratory responses to physically defined three-dimensional (3D) microenvironments and the factors that modulate those responses are critical to understanding how tissue migration is regulated during development, regeneration, and cancer. One key physical factor that regulates cell migration is topography. Most studies on surface topography and cell mechanics have been carried out with single migratory cells, yet little is known about the spreading and motility response of 3D complex multicellular tissues to topographical cues. Here, we examine the response to complex topographical cues of microsurgically isolated tissue explants composed of epithelial and mesenchymal cell layers from naturally 3D organized embryos of the aquatic frog Xenopus laevis. We control topography using fabricated micropost arrays (MPAs) and investigate the collective 3D migration of these multicellular systems in these MPAs. We find that the topography regulates both collective and individual cell migration and that dense MPAs reduce but do not eliminate tissue spreading. By modulating cell size through the cell cycle inhibitor Mitomycin C or the spacing of the MPAs we uncover how 3D topographical cues disrupt collective cell migration. We find surface topography can direct both single cell motility and tissue spreading, altering tissue-scale processes that enable efficient conversion of single cell motility into collective movement. PMID:25933063

  8. Operational Retrieval of aerosol optical depth over Indian subcontinent and Indian Ocean using INSAT-3D/Imager product validation

    NASA Astrophysics Data System (ADS)

    Mishra, M. K.; Rastogi, G.; Chauhan, P.

    2014-11-01

    Aerosol optical depth (AOD) over Indian subcontinent and Indian Ocean region is derived operationally for the first time from the geostationary earth orbit (GEO) satellite INSAT-3D Imager data at 0.65 μm wavelength. Single visible channel algorithm based on clear sky composites gives larger retrieval error in AOD than other multiple channel algorithms due to errors in estimating surface reflectance and atmospheric property. However, since MIR channel signal is insensitive to the presence of most aerosols, therefore in present study, AOD retrieval algorithm employs both visible (centred at 0.65 μm) and mid-infrared (MIR) band (centred at 3.9 μm) measurements, and allows us to monitor transport of aerosols at higher temporal resolution. Comparisons made between INSAT-3D derived AOD (τI) and MODIS derived AOD (τM) co-located in space (at 1° resolution) and time during January, February and March (JFM) 2014 encompasses 1165, 1052 and 900 pixels, respectively. Good agreement found between τI and τM during JFM 2014 with linear correlation coefficients (R) of 0.87, 0.81 and 0.76, respectively. The extensive validation made during JFM 2014 encompasses 215 co-located AOD in space and time derived by INSAT 3D (τI) and 10 sun-photometers (τA) that includes 9 AERONET (Aerosol Robotic Network) and 1 handheld sun-photometer site. INSAT-3D derived AOD i.e. τI, is found within the retrieval errors of τI = ±0.07 ±0.15τA with linear correlation coefficient (R) of 0.90 and root mean square error equal (RMSE) to 0.06. Present work shows that INSAT-3D aerosol products can be used quantitatively in many applications with caution for possible residual clouds, snow/ice, and water contamination.

  9. 3D-modeling of Callisto's sputtered surface-exosphere environment

    NASA Astrophysics Data System (ADS)

    Lammer, Helmut; Pfleger, Martin; Lindqvist, Jesper; Lichtenegger, Herbert; Holmström, Mats; Vorburger, Audrey; Wurz, Peter; Barabash, Stas

    2016-04-01

    We study the stoichiometrical release of various surface elements caused by plasma sputtering from an assumed icy and non-icy (i.e., chondritic) surface into the exosphere of the Jovian satellite Callisto. We apply a 3D plasma planetary interaction hybrid model that is used for the evaluation of precipitation maps of magnetospheric H+, O+ and S+ sputter agents onto Callisto's surface. The obtained precipitation maps are then applied to the assumed surface compositions where the related sputter yields are calculated by means of the 2013 SRIM code and are coupled with a 3D exosphere model. Sputtered surface particles are followed on their individual trajectories until they either escape Callisto's gravitational attraction or return to the surface. We study also the effect of collisions between sputter species and ambient O2 molecules which form a tiny atmosphere near the satellite's surface and compare the exosphere densities that are obtained from the 3D model with and without a background gaseous envelope with recent 1D model results. Finally we discuss if the Neutral gas and Ion Mass (NIM) spectrometer, that is part of the Particle Environment Package (PEP) on board of the JUICE mission will be able to detect sputtered particles from Callisto's icy and non-icy surface.

  10. Two-dimensional evaluation of 3D needled Cf/SiC composite fiber bundle surface

    NASA Astrophysics Data System (ADS)

    Wei, Jinhua; Lin, Bin; Cao, Xiaoyan; Zhang, Xiaofeng; Fang, Sheng

    2015-11-01

    The variations of fiber bundle surface microstructure have direct influence on the material performance, especially the friction and wear properties. Therefore, fiber bundle is the smallest evaluation unit of Cf/SiC composite surface. However, due to the anisotropy and inhomogeneity of Cf/SiC composite, it is difficult to evaluate the surface characteristics. Researchers think that two-dimensional evaluation is not suitable for the composites surface assessment any more because of its complex composition and varied surface structure. In this paper, a novel method is introduced for the evaluation of 3D needled Cf/SiC composite fiber bundle surface. On the level of Cf/SiC composite fiber bundle surface, two-dimensional evaluation method is adopted, with which the fiber bundle surface quality can be quantitatively evaluated by the two-dimensional surface roughness Ra. As long as the extracted surface profiles averagely distributed on Cf/SiC composite fiber bundle surface, with appropriate sampling length and sampling number, the mean value of Ra can estimate the whole surface roughness, thus reflecting the roughness degree of surface accurately. This study not only benefits the detection of 3D needled Cf/SiC composite fiber bundle surface quality, and lays a foundation on the evaluation of material functional features in further. And it corresponds to the convenient application in engineering practice.

  11. New light-trapping concept by means of several optical components applied to compact holographic 3D concentration solar module

    NASA Astrophysics Data System (ADS)

    Villamarín Villegas, Ayalid M.; Pérez López, Francisco J.; Calo López, Antonio; Rodríguez San Segundo, Hugo-José

    2014-05-01

    A new light-trapping concept is presented, which joins broad bandwidth volume phase reflection holograms (VPRH) working together with three other optical components: specifically designed three-dimensional (3D) cavities, Total Internal Reflection (TIR) within an optical medium, and specular reflection by means of a highly reflective surface. This concept is applied to the design and development of both low concentration photovoltaic (LCPV) and solar thermal modules reaching a concentration factor of up to 3X. Higher concentrations are feasible for use in concentrated solar power (CSP) devices. The whole system is entirely made of polymeric materials (except for the solar cells or fluid carrying pipes), thus reducing cost by up to 40%. The module concentrates solar light onto solar cells - or fluid carrying pipes - with no need for active tracking of the sun, covering the whole seasonal and daily incident angle spectrum while it also minimizes optical losses. In this work we analyze the first experimentally measured optical characteristics and performance of VPRH in dichromated gelatin film (DCG) in our concept. The VPRH can reach high diffraction efficiencies (˜98%, ignoring Fresnel reflection losses). Thanks to specifically designed raw material, coating and developing process specifications, also very broad selective spectral (higher than 300 nm) and angular bandwidths (˜+20º) per grating are achieved. The VPRH was optimized to use silicon solar cells, but designs for other semiconductor devices or for fluid heating are feasible. The 3D shape, the hologram's and reflective surface's optical quality, the TIR effect and the correct coupling of all the components are key to high performance of the concentration solar module.

  12. Hotspot-engineered 3D multipetal flower assemblies for surface-enhanced Raman spectroscopy.

    PubMed

    Jung, Kinam; Hahn, Jungsuk; In, Sungjun; Bae, Yongjun; Lee, Heechul; Pikhitsa, Peter V; Ahn, Kwangjun; Ha, Kyungyeon; Lee, Jong-Kwon; Park, Namkyoo; Choi, Mansoo

    2014-09-10

    Novel 3D metallic structures composed of multipetal flowers consisting of nanoparticles are presented. The control of surface plasmon hotspots is demonstrated in terms of location and intensity as a function of petal number for uniform and reproducible surfaceenhanced Raman spectroscopy (SERS) with high field enhancement.

  13. The use of 3D surface scanning for the measurement and assessment of the human foot

    PubMed Central

    2010-01-01

    Background A number of surface scanning systems with the ability to quickly and easily obtain 3D digital representations of the foot are now commercially available. This review aims to present a summary of the reported use of these technologies in footwear development, the design of customised orthotics, and investigations for other ergonomic purposes related to the foot. Methods The PubMed and ScienceDirect databases were searched. Reference lists and experts in the field were also consulted to identify additional articles. Studies in English which had 3D surface scanning of the foot as an integral element of their protocol were included in the review. Results Thirty-eight articles meeting the search criteria were included. Advantages and disadvantages of using 3D surface scanning systems are highlighted. A meta-analysis of studies using scanners to investigate the changes in foot dimensions during varying levels of weight bearing was carried out. Conclusions Modern 3D surface scanning systems can obtain accurate and repeatable digital representations of the foot shape and have been successfully used in medical, ergonomic and footwear development applications. The increasing affordability of these systems presents opportunities for researchers investigating the foot and for manufacturers of foot related apparel and devices, particularly those interested in producing items that are customised to the individual. Suggestions are made for future areas of research and for the standardization of the protocols used to produce foot scans. PMID:20815914

  14. Fiber optic vibration sensor for high-power electric machines realized using 3D printing technology

    NASA Astrophysics Data System (ADS)

    Igrec, Bojan; Bosiljevac, Marko; Sipus, Zvonimir; Babic, Dubravko; Rudan, Smiljko

    2016-03-01

    The objective of this work was to demonstrate a lightweight and inexpensive fiber-optic vibration sensor, built using 3D printing technology, for high-power electric machines and similar applications. The working principle is based on modulating the light intensity using a blade attached to a bendable membrane. The sensor prototype was manufactured using PolyJet Matrix technology with DM 8515 Grey 35 Polymer. The sensor shows linear response, expected bandwidth (< 150 Hz), and from our measurements we estimated the damping ratio for used polymer to be ζ ≍ 0.019. The developed prototype is simple to assemble, adjust, calibrate and repair.

  15. Ultra-compact on-chip LED collimation optics by 3D femtosecond direct laser writing.

    PubMed

    Thiele, Simon; Gissibl, Timo; Giessen, Harald; Herkommer, Alois M

    2016-07-01

    By using two-photon lithographic 3D printing, we demonstrate additive manufacturing of a dielectric concentrator directly on a LED chip. With a size of below 200 μm in diameter and length, light output is increased by a factor of 6.2 in collimation direction, while the emission half-angle is reduced by 50%. We measure excellent form fidelity and irradiance patterns close to simulation. Additionally, a more complex shape design is presented, which exhibits a nonconventional triangular illumination pattern. The introduced method features exceptional design freedoms which can be used to tailor high-quality miniature illumination optics for specific lighting tasks, for example, endoscopy. PMID:27367093

  16. 3D imaging of translucent media with a plenoptic sensor based on phase space optics

    NASA Astrophysics Data System (ADS)

    Zhang, Xuanzhe; Shu, Bohong; Du, Shaojun

    2015-05-01

    Traditional stereo imaging technology is not working for dynamical translucent media, because there are no obvious characteristic patterns on it and it's not allowed using multi-cameras in most cases, while phase space optics can solve the problem, extracting depth information directly from "space-spatial frequency" distribution of the target obtained by plenoptic sensor with single lens. This paper discussed the presentation of depth information in phase space data, and calculating algorithms with different transparency. A 3D imaging example of waterfall was given at last.

  17. XPS for non-destructive depth profiling and 3D imaging of surface nanostructures.

    PubMed

    Hajati, Shaaker; Tougaard, Sven

    2010-04-01

    Depth profiling of nanostructures is of high importance both technologically and fundamentally. Therefore, many different methods have been developed for determination of the depth distribution of atoms, for example ion beam (e.g. O(2)(+) , Ar(+)) sputtering, low-damage C(60) cluster ion sputtering for depth profiling of organic materials, water droplet cluster ion beam depth profiling, ion-probing techniques (Rutherford backscattering spectroscopy (RBS), secondary-ion mass spectroscopy (SIMS) and glow-discharge optical emission spectroscopy (GDOES)), X-ray microanalysis using the electron probe variation technique combined with Monte Carlo calculations, angle-resolved XPS (ARXPS), and X-ray photoelectron spectroscopy (XPS) peak-shape analysis. Each of the depth profiling techniques has its own advantages and disadvantages. However, in many cases, non-destructive techniques are preferred; these include ARXPS and XPS peak-shape analysis. The former together with parallel factor analysis is suitable for giving an overall understanding of chemistry and morphology with depth. It works very well for flat surfaces but it fails for rough or nanostructured surfaces because of the shadowing effect. In the latter method shadowing effects can be avoided because only a single spectrum is used in the analysis and this may be taken at near normal emission angle. It is a rather robust means of determining atom depth distributions on the nanoscale both for large-area XPS analysis and for imaging. We critically discuss some of the techniques mentioned above and show that both ARXPS imaging and, particularly, XPS peak-shape analysis for 3D imaging of nanostructures are very promising techniques and open a gateway for visualizing nanostructures. PMID:20091159

  18. Active illumination based 3D surface reconstruction and registration for image guided medialization laryngoplasty

    NASA Astrophysics Data System (ADS)

    Jin, Ge; Lee, Sang-Joon; Hahn, James K.; Bielamowicz, Steven; Mittal, Rajat; Walsh, Raymond

    2007-03-01

    The medialization laryngoplasty is a surgical procedure to improve the voice function of the patient with vocal fold paresis and paralysis. An image guided system for the medialization laryngoplasty will help the surgeons to accurately place the implant and thus reduce the failure rates of the surgery. One of the fundamental challenges in image guided system is to accurately register the preoperative radiological data to the intraoperative anatomical structure of the patient. In this paper, we present a combined surface and fiducial based registration method to register the preoperative 3D CT data to the intraoperative surface of larynx. To accurately model the exposed surface area, a structured light based stereo vision technique is used for the surface reconstruction. We combined the gray code pattern and multi-line shifting to generate the intraoperative surface of the larynx. To register the point clouds from the intraoperative stage to the preoperative 3D CT data, a shape priori based ICP method is proposed to quickly register the two surfaces. The proposed approach is capable of tracking the fiducial markers and reconstructing the surface of larynx with no damage to the anatomical structure. We used off-the-shelf digital cameras, LCD projector and rapid 3D prototyper to develop our experimental system. The final RMS error in the registration is less than 1mm.

  19. Reconstruction Accuracy Assessment of Surface and Underwater 3D Motion Analysis: A New Approach.

    PubMed

    de Jesus, Kelly; de Jesus, Karla; Figueiredo, Pedro; Vilas-Boas, João Paulo; Fernandes, Ricardo Jorge; Machado, Leandro José

    2015-01-01

    This study assessed accuracy of surface and underwater 3D reconstruction of a calibration volume with and without homography. A calibration volume (6000 × 2000 × 2500 mm) with 236 markers (64 above and 88 underwater control points--with 8 common points at water surface--and 92 validation points) was positioned on a 25 m swimming pool and recorded with two surface and four underwater cameras. Planar homography estimation for each calibration plane was computed to perform image rectification. Direct linear transformation algorithm for 3D reconstruction was applied, using 1600000 different combinations of 32 and 44 points out of the 64 and 88 control points for surface and underwater markers (resp.). Root Mean Square (RMS) error with homography of control and validations points was lower than without it for surface and underwater cameras (P ≤ 0.03). With homography, RMS errors of control and validation points were similar between surface and underwater cameras (P ≥ 0.47). Without homography, RMS error of control points was greater for underwater than surface cameras (P ≤ 0.04) and the opposite was observed for validation points (P ≤ 0.04). It is recommended that future studies using 3D reconstruction should include homography to improve swimming movement analysis accuracy.

  20. 3D surface topography of cylinder liner forecasting during plateau honing process

    NASA Astrophysics Data System (ADS)

    Reizer, R.; Pawlus, P.

    2011-08-01

    Areal surface topographies after plateau honing process were measured. A correlation analysis of surface texture parameters was then carried out. As the results, the following parameters describing plateau honed cylinder 3D surface topography were selected: amplitude Sq, Sz, spatial: Str, Std, hybrid SΔq as well as functional: Spq, Svq and Smq. 3D surface topographies were modeled. The modeled surface topographies were correctly matched to measured ones in 77% of all analyzed cases. The plateau honing experiment was then carried out using an orthogonal selective research plan. Two machining parameters were input variables: coarse honing pressure pv and plateau honing time t. Chosen cylinder liners texture parameters were output values. As the result of the experiment, regression equations connecting plateau honing process parameters pv and t with recommended 3D surface topography parameters were obtained. Finally, cylinder liner surface topographies were predicted for various values of machining parameters. Proper matching accuracy of modeled to measured textures was assured in 67% of analyzed cases.

  1. Optimal Image Stitching for Concrete Bridge Bottom Surfaces Aided by 3d Structure Lines

    NASA Astrophysics Data System (ADS)

    Liu, Yahui; Yao, Jian; Liu, Kang; Lu, Xiaohu; Xia, Menghan

    2016-06-01

    Crack detection for bridge bottom surfaces via remote sensing techniques is undergoing a revolution in the last few years. For such applications, a large amount of images, acquired with high-resolution industrial cameras close to the bottom surfaces with some mobile platform, are required to be stitched into a wide-view single composite image. The conventional idea of stitching a panorama with the affine model or the homographic model always suffers a series of serious problems due to poor texture and out-of-focus blurring introduced by depth of field. In this paper, we present a novel method to seamlessly stitch these images aided by 3D structure lines of bridge bottom surfaces, which are extracted from 3D camera data. First, we propose to initially align each image in geometry based on its rough position and orientation acquired with both a laser range finder (LRF) and a high-precision incremental encoder, and these images are divided into several groups with the rough position and orientation data. Secondly, the 3D structure lines of bridge bottom surfaces are extracted from the 3D cloud points acquired with 3D cameras, which impose additional strong constraints on geometrical alignment of structure lines in adjacent images to perform a position and orientation optimization in each group to increase the local consistency. Thirdly, a homographic refinement between groups is applied to increase the global consistency. Finally, we apply a multi-band blending algorithm to generate a large-view single composite image as seamlessly as possible, which greatly eliminates both the luminance differences and the color deviations between images and further conceals image parallax. Experimental results on a set of representative images acquired from real bridge bottom surfaces illustrate the superiority of our proposed approaches.

  2. 3D surface roughness measurement for scaliness scoring of psoriasis lesions.

    PubMed

    Ahmad Fadzil, M Hani; Prakasa, Esa; Asirvadam, Vijanth Sagayan; Nugroho, Hermawan; Affandi, Azura Mohd; Hussein, Suraiya Hani

    2013-11-01

    Psoriasis is an incurable skin disorder affecting 2-3% of the world population. The scaliness of psoriasis is a key assessment parameter of the Psoriasis Area and Severity Index (PASI). Dermatologists typically use visual and tactile senses in PASI scaliness assessment. However, the assessment can be subjective resulting in inter- and intra-rater variability in the scores. This paper proposes an assessment method that incorporates 3D surface roughness with standard clustering techniques to objectively determine the PASI scaliness score for psoriasis lesions. A surface roughness algorithm using structured light projection has been applied to 1999 3D psoriasis lesion surfaces. The algorithm has been validated with an accuracy of 94.12%. Clustering algorithms were used to classify the surface roughness measured using the proposed assessment method for PASI scaliness scoring. The reliability of the developed PASI scaliness algorithm was high with kappa coefficients>0.84 (almost perfect agreement).

  3. 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.

  4. Polymer optical fibers integrated directly into 3D orthogonal woven composites for sensing

    NASA Astrophysics Data System (ADS)

    Hamouda, Tamer; Seyam, Abdel-Fattah M.; Peters, Kara

    2015-02-01

    This study demonstrates that standard polymer optical fibers (POF) can be directly integrated into composites from 3D orthogonal woven preforms during the weaving process and then serve as in-situ sensors to detect damage due to bending or impact loads. Different composite samples with embedded POF were fabricated of 3D orthogonal woven composites with different parameters namely number of y-/x-layers and x-yarn density. The signal of POF was not affected significantly by the preform structure. During application of resin using VARTM technique, significant drop in backscattering level was observed due to pressure caused by vacuum on the embedded POF. Measurements of POF signal while in the final composites after resin cure indicated that the backscattering level almost returned to the original level of un-embedded POF. The POF responded to application of bending and impact loads to the composite with a reduction in the backscattering level. The backscattering level almost returned back to its original level after removing the bending load until damage was present in the composite. Similar behavior occurred due to impact events. As the POF itself is used as the sensor and can be integrated throughout the composite, large sections of future 3D woven composite structures could be monitored without the need for specialized sensors or complex instrumentation.

  5. Diffractive 3D XUV optics at Helmholtz-Zentrum Berlin, recent developments

    NASA Astrophysics Data System (ADS)

    Brzhezinskaya, Maria; Firsov, Alexander; Erko, Alexei

    2014-09-01

    The 2-Dimensional and 3-Dimensional variable line spacing (VLS) gratings based on total external reflection give the unique possibility for spectroscopy and focusing in application to 4th and 5th generation synchrotron sources. We focus on the elaboration of novel approaches for design and fabrication of 3D VLS working in the entire energy range, from THz to hard X-rays. These optical elements have unique combination of properties and can operate at all XUV sources including Free Electron Lasers (FELs), Energy Recovery Linacs (ERLs) and High Harmonic Generators (HHGs). Such 3D DOEs are able to cover the energy range of up to 20 keV with energy resolution λ/Δλ ≥ 1000 for soft x-ray and λ/Δλ ≥ 10000 for hard x-ray. We fabricate 3D VLS for time-resolved spectroscopy (energy range 100 - 2000 eV, 7500-9500 eV), FELs and ERLs (energy range up to 3 keV), and HHGs (energy range 10 - 200 eV).

  6. Controlled implant/soft tissue interaction by nanoscale surface modifications of 3D porous titanium implants.

    PubMed

    Rieger, Elisabeth; Dupret-Bories, Agnès; Salou, Laetitia; Metz-Boutigue, Marie-Helene; Layrolle, Pierre; Debry, Christian; Lavalle, Philippe; Vrana, Nihal Engin

    2015-06-01

    Porous titanium implants are widely employed in the orthopaedics field to ensure good bone fixation. Recently, the use of porous titanium implants has also been investigated in artificial larynx development in a clinical setting. Such uses necessitate a better understanding of the interaction of soft tissues with porous titanium structures. Moreover, surface treatments of titanium have been generally evaluated in planar structures, while the porous titanium implants have complex 3 dimensional (3D) architectures. In this study, the determining factors for soft tissue integration of 3D porous titanium implants were investigated as a function of surface treatments via quantification of the interaction of serum proteins and cells with single titanium microbeads (300-500 μm in diameter). Samples were either acid etched or nanostructured by anodization. When the samples are used in 3D configuration (porous titanium discs of 2 mm thickness) in vivo (in subcutis of rats for 2 weeks), a better integration was observed for both anodized and acid etched samples compared to the non-treated implants. If the implants were also pre-treated with rat serum before implantation, the integration was further facilitated. In order to understand the underlying reasons for this effect, human fibroblast cell culture tests under several conditions (directly on beads, beads in suspension, beads encapsulated in gelatin hydrogels) were conducted to mimic the different interactions of cells with Ti implants in vivo. Physical characterization showed that surface treatments increased hydrophilicity, protein adsorption and roughness. Surface treatments also resulted in improved adsorption of serum albumin which in turn facilitated the adsorption of other proteins such as apolipoprotein as quantified by protein sequencing. The cellular response to the beads showed considerable difference with respect to the cell culture configuration. When the titanium microbeads were entrapped in cell

  7. An improved parallel SPH approach to solve 3D transient generalized Newtonian free surface flows

    NASA Astrophysics Data System (ADS)

    Ren, Jinlian; Jiang, Tao; Lu, Weigang; Li, Gang

    2016-08-01

    In this paper, a corrected parallel smoothed particle hydrodynamics (C-SPH) method is proposed to simulate the 3D generalized Newtonian free surface flows with low Reynolds number, especially the 3D viscous jets buckling problems are investigated. The proposed C-SPH method is achieved by coupling an improved SPH method based on the incompressible condition with the traditional SPH (TSPH), that is, the improved SPH with diffusive term and first-order Kernel gradient correction scheme is used in the interior of the fluid domain, and the TSPH is used near the free surface. Thus the C-SPH method possesses the advantages of two methods. Meanwhile, an effective and convenient boundary treatment is presented to deal with 3D multiple-boundary problem, and the MPI parallelization technique with a dynamic cells neighbor particle searching method is considered to improve the computational efficiency. The validity and the merits of the C-SPH are first verified by solving several benchmarks and compared with other results. Then the viscous jet folding/coiling based on the Cross model is simulated by the C-SPH method and compared with other experimental or numerical results. Specially, the influences of macroscopic parameters on the flow are discussed. All the numerical results agree well with available data, and show that the C-SPH method has higher accuracy and better stability for solving 3D moving free surface flows over other particle methods.

  8. 3D Surface Reconstruction of Plant Seeds by Volume Carving: Performance and Accuracies

    PubMed Central

    Roussel, Johanna; Geiger, Felix; Fischbach, Andreas; Jahnke, Siegfried; Scharr, Hanno

    2016-01-01

    We describe a method for 3D reconstruction of plant seed surfaces, focusing on small seeds with diameters as small as 200 μm. The method considers robotized systems allowing single seed handling in order to rotate a single seed in front of a camera. Even though such systems feature high position repeatability, at sub-millimeter object scales, camera pose variations have to be compensated. We do this by robustly estimating the tool center point from each acquired image. 3D reconstruction can then be performed by a simple shape-from-silhouette approach. In experiments we investigate runtimes, theoretically achievable accuracy, experimentally achieved accuracy, and show as a proof of principle that the proposed method is well sufficient for 3D seed phenotyping purposes. PMID:27375628

  9. Reconstructing White Walls: Multi-View Multi-Shot 3d Reconstruction of Textureless Surfaces

    NASA Astrophysics Data System (ADS)

    Ley, Andreas; Hänsch, Ronny; Hellwich, Olaf

    2016-06-01

    The reconstruction of the 3D geometry of a scene based on image sequences has been a very active field of research for decades. Nevertheless, there are still existing challenges in particular for homogeneous parts of objects. This paper proposes a solution to enhance the 3D reconstruction of weakly-textured surfaces by using standard cameras as well as a standard multi-view stereo pipeline. The underlying idea of the proposed method is based on improving the signal-to-noise ratio in weakly-textured regions while adaptively amplifying the local contrast to make better use of the limited numerical range in 8-bit images. Based on this premise, multiple shots per viewpoint are used to suppress statistically uncorrelated noise and enhance low-contrast texture. By only changing the image acquisition and adding a preprocessing step, a tremendous increase of up to 300% in completeness of the 3D reconstruction is achieved.

  10. 3D displacement field measurement with correlation based on the micro-geometrical surface texture

    NASA Astrophysics Data System (ADS)

    Bubaker-Isheil, Halima; Serri, Jérôme; Fontaine, Jean-François

    2011-07-01

    Image correlation methods are widely used in experimental mechanics to obtain displacement field measurements. Currently, these methods are applied using digital images of the initial and deformed surfaces sprayed with black or white paint. Speckle patterns are then captured and the correlation is performed with a high degree of accuracy to an order of 0.01 pixels. In 3D, however, stereo-correlation leads to a lower degree of accuracy. Correlation techniques are based on the search for a sub-image (or pattern) displacement field. The work presented in this paper introduces a new correlation-based approach for 3D displacement field measurement that uses an additional 3D laser scanner and a CMM (Coordinate Measurement Machine). Unlike most existing methods that require the presence of markers on the observed object (such as black speckle, grids or random patterns), this approach relies solely on micro-geometrical surface textures such as waviness, roughness and aperiodic random defects. The latter are assumed to remain sufficiently small thus providing an adequate estimate of the particle displacement. The proposed approach can be used in a wide range of applications such as sheet metal forming with large strains. The method proceeds by first obtaining cloud points using the 3D laser scanner mounted on a CMM. These points are used to create 2D maps that are then correlated. In this respect, various criteria have been investigated for creating maps consisting of patterns, which facilitate the correlation procedure. Once the maps are created, the correlation between both configurations (initial and moved) is carried out using traditional methods developed for field measurements. Measurement validation was conducted using experiments in 2D and 3D with good results for rigid displacements in 2D, 3D and 2D rotations.

  11. Optically clearing tissue as an initial step for 3D imaging of core biopsies to diagnose pancreatic cancer

    NASA Astrophysics Data System (ADS)

    Das, Ronnie; Agrawal, Aishwarya; Upton, Melissa P.; Seibel, Eric J.

    2014-02-01

    The pancreas is a deeply seated organ requiring endoscopically, or radiologically guided biopsies for tissue diagnosis. Current approaches include either fine needle aspiration biopsy (FNA) for cytologic evaluation, or core needle biopsies (CBs), which comprise of tissue cores (L = 1-2 cm, D = 0.4-2.0 mm) for examination by brightfield microscopy. Between procurement and visualization, biospecimens must be processed, sectioned and mounted on glass slides for 2D visualization. Optical information about the native tissue state can be lost with each procedural step and a pathologist cannot appreciate 3D organization from 2D observations of tissue sections 1-8 μm in thickness. Therefore, how might histological disease assessment improve if entire, intact CBs could be imaged in both brightfield and 3D? CBs are mechanically delicate; therefore, a simple device was made to cut intact, simulated CBs (L = 1-2 cm, D = 0.2-0.8 mm) from porcine pancreas. After CBs were laid flat in a chamber, z-stack images at 20x and 40x were acquired through the sample with and without the application of an optical clearing agent (FocusClear®). Intensity of transmitted light increased by 5-15x and islet structures unique to pancreas were clearly visualized 250-300 μm beneath the tissue surface. CBs were then placed in index matching square capillary tubes filled with FocusClear® and a standard optical clearing agent. Brightfield z-stack images were then acquired to present 3D visualization of the CB to the pathologist.

  12. Three-axis distributed fiber optic strain measurement in 3D woven composite structures

    NASA Astrophysics Data System (ADS)

    Castellucci, Matt; Klute, Sandra; Lally, Evan M.; Froggatt, Mark E.; Lowry, David

    2013-03-01

    Recent advancements in composite materials technologies have broken further from traditional designs and require advanced instrumentation and analysis capabilities. Success or failure is highly dependent on design analysis and manufacturing processes. By monitoring smart structures throughout manufacturing and service life, residual and operational stresses can be assessed and structural integrity maintained. Composite smart structures can be manufactured by integrating fiber optic sensors into existing composite materials processes such as ply layup, filament winding and three-dimensional weaving. In this work optical fiber was integrated into 3D woven composite parts at a commercial woven products manufacturing facility. The fiber was then used to monitor the structures during a VARTM manufacturing process, and subsequent static and dynamic testing. Low cost telecommunications-grade optical fiber acts as the sensor using a high resolution commercial Optical Frequency Domain Reflectometer (OFDR) system providing distributed strain measurement at spatial resolutions as low as 2mm. Strain measurements using the optical fiber sensors are correlated to resistive strain gage measurements during static structural loading.

  13. SU-F-BRF-08: Conformal Mapping-Based 3D Surface Matching and Registration

    SciTech Connect

    Song, Y; Zeng, W; Gu, X; Liu, C

    2014-06-15

    Purpose: Recently, non-rigid 3D surface matching and registration has been used extensively in engineering and medicine. However, matching 3D surfaces undergoing non-rigid deformation accurately is still a challenging mathematical problem. In this study, we present a novel algorithm to address this issue by introducing intrinsic symmetry to the registration Methods: Our computational algorithm for symmetric conformal mapping is divided into three major steps: 1) Finding the symmetric plane; 2) Finding feature points; and 3) Performing cross registration. The key strategy is to preserve the symmetry during the conformal mapping, such that the image on the parameter domain is symmetric and the area distortion factor on the parameter image is also symmetric. Several novel algorithms were developed using different conformal geometric tools. One was based on solving Riemann-Cauchy equation and the other one employed curvature flow Results: Our algorithm was implemented using generic C++ on Windows XP and used conjugate gradient search optimization for acceleration. The human face 3D surface images were acquired using a high speed 3D scanner based on the phase-shifting method. The scanning speed was 30 frames/sec. The image resolution for each frame was 640 × 480. For 3D human face surfaces with different expressions, postures, and boundaries, our algorithms were able to produce consistent result on the texture pattern on the overlapping region Conclusion: We proposed a novel algorithm to improve the robustness of conformal geometric methods by incorporating the symmetric information into the mapping process. To objectively evaluate its performance, we compared it with most existing techniques. Experimental results indicated that our method outperformed all the others in terms of robustness. The technique has a great potential in real-time patient monitoring and tracking in image-guided radiation therapy.

  14. Optical-CT 3D Dosimetry Using Fresnel Lenses with Minimal Refractive-Index Matching Fluid

    PubMed Central

    Bache, Steven; Malcolm, Javian; Adamovics, John; Oldham, Mark

    2016-01-01

    Telecentric optical computed tomography (optical-CT) is a state-of-the-art method for visualizing and quantifying 3-dimensional dose distributions in radiochromic dosimeters. In this work a prototype telecentric system (DFOS—Duke Fresnel Optical-CT Scanner) is evaluated which incorporates two substantial design changes: the use of Fresnel lenses (reducing lens costs from $10-30K t0 $1-3K) and the use of a ‘solid tank’ (which reduces noise, and the volume of refractively matched fluid from 1ltr to 10cc). The efficacy of DFOS was evaluated by direct comparison against commissioned scanners in our lab. Measured dose distributions from all systems were compared against the predicted dose distributions from a commissioned treatment planning system (TPS). Three treatment plans were investigated including a simple four-field box treatment, a multiple small field delivery, and a complex IMRT treatment. Dosimeters were imaged within 2h post irradiation, using consistent scanning techniques (360 projections acquired at 1 degree intervals, reconstruction at 2mm). DFOS efficacy was evaluated through inspection of dose line-profiles, and 2D and 3D dose and gamma maps. DFOS/TPS gamma pass rates with 3%/3mm dose difference/distance-to-agreement criteria ranged from 89.3% to 92.2%, compared to from 95.6% to 99.0% obtained with the commissioned system. The 3D gamma pass rate between the commissioned system and DFOS was 98.2%. The typical noise rates in DFOS reconstructions were up to 3%, compared to under 2% for the commissioned system. In conclusion, while the introduction of a solid tank proved advantageous with regards to cost and convenience, further work is required to improve the image quality and dose reconstruction accuracy of the new DFOS optical-CT system. PMID:27019460

  15. Optical-CT 3D Dosimetry Using Fresnel Lenses with Minimal Refractive-Index Matching Fluid.

    PubMed

    Bache, Steven; Malcolm, Javian; Adamovics, John; Oldham, Mark

    2016-01-01

    Telecentric optical computed tomography (optical-CT) is a state-of-the-art method for visualizing and quantifying 3-dimensional dose distributions in radiochromic dosimeters. In this work a prototype telecentric system (DFOS-Duke Fresnel Optical-CT Scanner) is evaluated which incorporates two substantial design changes: the use of Fresnel lenses (reducing lens costs from $10-30K t0 $1-3K) and the use of a 'solid tank' (which reduces noise, and the volume of refractively matched fluid from 1 ltr to 10 cc). The efficacy of DFOS was evaluated by direct comparison against commissioned scanners in our lab. Measured dose distributions from all systems were compared against the predicted dose distributions from a commissioned treatment planning system (TPS). Three treatment plans were investigated including a simple four-field box treatment, a multiple small field delivery, and a complex IMRT treatment. Dosimeters were imaged within 2 h post irradiation, using consistent scanning techniques (360 projections acquired at 1 degree intervals, reconstruction at 2mm). DFOS efficacy was evaluated through inspection of dose line-profiles, and 2D and 3D dose and gamma maps. DFOS/TPS gamma pass rates with 3%/3mm dose difference/distance-to-agreement criteria ranged from 89.3% to 92.2%, compared to from 95.6% to 99.0% obtained with the commissioned system. The 3D gamma pass rate between the commissioned system and DFOS was 98.2%. The typical noise rates in DFOS reconstructions were up to 3%, compared to under 2% for the commissioned system. In conclusion, while the introduction of a solid tank proved advantageous with regards to cost and convenience, further work is required to improve the image quality and dose reconstruction accuracy of the new DFOS optical-CT system.

  16. Optical-CT 3D Dosimetry Using Fresnel Lenses with Minimal Refractive-Index Matching Fluid.

    PubMed

    Bache, Steven; Malcolm, Javian; Adamovics, John; Oldham, Mark

    2016-01-01

    Telecentric optical computed tomography (optical-CT) is a state-of-the-art method for visualizing and quantifying 3-dimensional dose distributions in radiochromic dosimeters. In this work a prototype telecentric system (DFOS-Duke Fresnel Optical-CT Scanner) is evaluated which incorporates two substantial design changes: the use of Fresnel lenses (reducing lens costs from $10-30K t0 $1-3K) and the use of a 'solid tank' (which reduces noise, and the volume of refractively matched fluid from 1 ltr to 10 cc). The efficacy of DFOS was evaluated by direct comparison against commissioned scanners in our lab. Measured dose distributions from all systems were compared against the predicted dose distributions from a commissioned treatment planning system (TPS). Three treatment plans were investigated including a simple four-field box treatment, a multiple small field delivery, and a complex IMRT treatment. Dosimeters were imaged within 2 h post irradiation, using consistent scanning techniques (360 projections acquired at 1 degree intervals, reconstruction at 2mm). DFOS efficacy was evaluated through inspection of dose line-profiles, and 2D and 3D dose and gamma maps. DFOS/TPS gamma pass rates with 3%/3mm dose difference/distance-to-agreement criteria ranged from 89.3% to 92.2%, compared to from 95.6% to 99.0% obtained with the commissioned system. The 3D gamma pass rate between the commissioned system and DFOS was 98.2%. The typical noise rates in DFOS reconstructions were up to 3%, compared to under 2% for the commissioned system. In conclusion, while the introduction of a solid tank proved advantageous with regards to cost and convenience, further work is required to improve the image quality and dose reconstruction accuracy of the new DFOS optical-CT system. PMID:27019460

  17. Reconstruction and Visualization of Coordinated 3D Cell Migration Based on Optical Flow.

    PubMed

    Kappe, Christopher P; Schütz, Lucas; Gunther, Stefan; Hufnagel, Lars; Lemke, Steffen; Leitte, Heike

    2016-01-01

    Animal development is marked by the repeated reorganization of cells and cell populations, which ultimately determine form and shape of the growing organism. One of the central questions in developmental biology is to understand precisely how cells reorganize, as well as how and to what extent this reorganization is coordinated. While modern microscopes can record video data for every cell during animal development in 3D+t, analyzing these videos remains a major challenge: reconstruction of comprehensive cell tracks turned out to be very demanding especially with decreasing data quality and increasing cell densities. In this paper, we present an analysis pipeline for coordinated cellular motions in developing embryos based on the optical flow of a series of 3D images. We use numerical integration to reconstruct cellular long-term motions in the optical flow of the video, we take care of data validation, and we derive a LIC-based, dense flow visualization for the resulting pathlines. This approach allows us to handle low video quality such as noisy data or poorly separated cells, and it allows the biologists to get a comprehensive understanding of their data by capturing dynamic growth processes in stills. We validate our methods using three videos of growing fruit fly embryos.

  18. Fast parallel interferometric 3D tracking of numerous optically trapped particles and their hydrodynamic interaction.

    PubMed

    Ruh, Dominic; Tränkle, Benjamin; Rohrbach, Alexander

    2011-10-24

    Multi-dimensional, correlated particle tracking is a key technology to reveal dynamic processes in living and synthetic soft matter systems. In this paper we present a new method for tracking micron-sized beads in parallel and in all three dimensions - faster and more precise than existing techniques. Using an acousto-optic deflector and two quadrant-photo-diodes, we can track numerous optically trapped beads at up to tens of kHz with a precision of a few nanometers by back-focal plane interferometry. By time-multiplexing the laser focus, we can calibrate individually all traps and all tracking signals in a few seconds and in 3D. We show 3D histograms and calibration constants for nine beads in a quadratic arrangement, although trapping and tracking is easily possible for more beads also in arbitrary 2D arrangements. As an application, we investigate the hydrodynamic coupling and diffusion anomalies of spheres trapped in a 3 × 3 arrangement. PMID:22109012

  19. How effective can optical-CT 3D dosimetry be without refractive fluid matching?

    PubMed Central

    Rankine, L; Oldham

    2013-01-01

    Achieving accurate optical CT 3D dosimetry without the use of viscous refractive index (RI) matching fluids would greatly increase convenience. Software has been developed to simulate optical CT 3D dosimetry for a range of scanning configurations including parallel-beam, point and converging light sources. For each configuration the efficacy of 3 refractive media were investigated: air, water, and a fluid closely matched to Presage (RI = 1.00, 1.33 and 1.49 respectively). The results revealed that the useable radius of the dosimeter (i.e. where data was within 2% of truth) reduced to 68% for water-matching, and 31% for dry-scanning in air. Point source incident ray geometry produced slightly more favourable results, although variation between the three geometries was relatively small. The required detector size however, increased by a factor six for dry-scanning, introducing cost penalties. For applications where dose information is not required in the periphery, some dry and low-viscous matching configurations may be feasible. PMID:24454520

  20. Improved Uav-Borne 3d Mapping by Fusing Optical and Laserscanner Data

    NASA Astrophysics Data System (ADS)

    Jutzi, B.; Weinmann, M.; Meidow, J.

    2013-08-01

    In this paper, a new method for fusing optical and laserscanner data is presented for improved UAV-borne 3D mapping. We propose to equip an unmanned aerial vehicle (UAV) with a small platform which includes two sensors: a standard low-cost digital camera and a lightweight Hokuyo UTM-30LX-EW laserscanning device (210 g without cable). Initially, a calibration is carried out for the utilized devices. This involves a geometric camera calibration and the estimation of the position and orientation offset between the two sensors by lever-arm and bore-sight calibration. Subsequently, a feature tracking is performed through the image sequence by considering extracted interest points as well as the projected 3D laser points. These 2D results are fused with the measured laser distances and fed into a bundle adjustment in order to obtain a Simultaneous Localization and Mapping (SLAM). It is demonstrated that an improvement in terms of precision for the pose estimation is derived by fusing optical and laserscanner data.

  1. 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. PMID:26558410

  2. 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

  3. Consistent Multi-View Texturing of Detailed 3d Surface Models

    NASA Astrophysics Data System (ADS)

    Davydova, K.; Kuschk, G.; Hoegner, L.; Reinartz, P.; Stilla, U.

    2015-03-01

    Texture mapping techniques are used to achieve a high degree of realism for computer generated large-scale and detailed 3D surface models by extracting the texture information from photographic images and applying it to the object surfaces. Due to the fact that a single image cannot capture all parts of the scene, a number of images should be taken. However, texturing the object surfaces from several images can lead to lighting variations between the neighboring texture fragments. In this paper we describe the creation of a textured 3D scene from overlapping aerial images using a Markov Random Field energy minimization framework. We aim to maximize the quality of the generated texture mosaic, preserving the resolution from the original images, and at the same time to minimize the seam visibilities between adjacent fragments. As input data we use a triangulated mesh of the city center of Munich and multiple camera views of the scene from different directions.

  4. Dynamics of tokamak plasma surface current in 3D ideal MHD model

    NASA Astrophysics Data System (ADS)

    Galkin, Sergei A.; Svidzinski, V. A.; Zakharov, L. E.

    2013-10-01

    Interest in the surface current which can arise on perturbed sharp plasma vacuum interface in tokamaks was recently generated by a few papers (see and references therein). In dangerous disruption events with plasma-touching-wall scenarios, the surface current can be shared with the wall leading to the strong, damaging forces acting on the wall A relatively simple analytic definition of δ-function surface current proportional to a jump of tangential component of magnetic field nevertheless leads to a complex computational problem on the moving plasma-vacuum interface, requiring the incorporation of non-linear 3D plasma dynamics even in one-fluid ideal MHD. The Disruption Simulation Code (DSC), which had recently been developed in a fully 3D toroidal geometry with adaptation to the moving plasma boundary, is an appropriate tool for accurate self-consistent δfunction surface current calculation. Progress on the DSC-3D development will be presented. Self-consistent surface current calculation under non-linear dynamics of low m kink mode and VDE will be discussed. Work is supported by the US DOE SBIR grant #DE-SC0004487.

  5. SU-E-J-209: Verification of 3D Surface Registration Between Stereograms and CT Images

    SciTech Connect

    Han, T; Gifford, K; Smith, B; Salehpour, M

    2014-06-01

    Purpose: Stereography can provide a visualization of the skin surface for radiation therapy patients. The aim of this study was to verify the registration algorithm in a commercial image analysis software, 3dMDVultus, for the fusion of stereograms and CT images. Methods: CT and stereographic scans were acquired of a head phantom and a deformable phantom. CT images were imported in 3dMDVultus and the surface contours were generated by threshold segmentation. Stereograms were reconstructed in 3dMDVultus. The resulting surfaces were registered with Vultus algorithm and then exported to in-house registration software and compared with four algorithms: rigid, affine, non-rigid iterative closest point (ICP) and b-spline algorithm. RMS (root-mean-square residuals of the surface point distances) error between the registered CT and stereogram surfaces was calculated and analyzed. Results: For the head phantom, the maximum RMS error between registered CT surfaces to stereogram was 6.6 mm for Vultus algorithm, whereas the mean RMS error was 0.7 mm. For the deformable phantom, the maximum RMS error was 16.2 mm for Vultus algorithm, whereas the mean RMS error was 4.4 mm. Non-rigid ICP demonstrated the best registration accuracy, as the mean of RMS errors were both within 1 mm. Conclusion: The accuracy of registration algorithm in 3dMDVultus was verified and exceeded RMS of 2 mm for deformable cases. Non-rigid ICP and b-spline algorithms improve the registration accuracy for both phantoms, especially in deformable one. For those patients whose body habitus deforms during radiation therapy, more advanced nonrigid algorithms need to be used.

  6. Segmentation of whole cells and cell nuclei from 3-D optical microscope images using dynamic programming.

    PubMed

    McCullough, D P; Gudla, P R; Harris, B S; Collins, J A; Meaburn, K J; Nakaya, M A; Yamaguchi, T P; Misteli, T; Lockett, S J

    2008-05-01

    Communications between cells in large part drive tissue development and function, as well as disease-related processes such as tumorigenesis. Understanding the mechanistic bases of these processes necessitates quantifying specific molecules in adjacent cells or cell nuclei of intact tissue. However, a major restriction on such analyses is the lack of an efficient method that correctly segments each object (cell or nucleus) from 3-D images of an intact tissue specimen. We report a highly reliable and accurate semi-automatic algorithmic method for segmenting fluorescence-labeled cells or nuclei from 3-D tissue images. Segmentation begins with semi-automatic, 2-D object delineation in a user-selected plane, using dynamic programming (DP) to locate the border with an accumulated intensity per unit length greater that any other possible border around the same object. Then the two surfaces of the object in planes above and below the selected plane are found using an algorithm that combines DP and combinatorial searching. Following segmentation, any perceived errors can be interactively corrected. Segmentation accuracy is not significantly affected by intermittent labeling of object surfaces, diffuse surfaces, or spurious signals away from surfaces. The unique strength of the segmentation method was demonstrated on a variety of biological tissue samples where all cells, including irregularly shaped cells, were accurately segmented based on visual inspection.

  7. Controlled implant/soft tissue interaction by nanoscale surface modifications of 3D porous titanium implants

    NASA Astrophysics Data System (ADS)

    Rieger, Elisabeth; Dupret-Bories, Agnès; Salou, Laetitia; Metz-Boutigue, Marie-Helene; Layrolle, Pierre; Debry, Christian; Lavalle, Philippe; Engin Vrana, Nihal

    2015-05-01

    Porous titanium implants are widely employed in the orthopaedics field to ensure good bone fixation. Recently, the use of porous titanium implants has also been investigated in artificial larynx development in a clinical setting. Such uses necessitate a better understanding of the interaction of soft tissues with porous titanium structures. Moreover, surface treatments of titanium have been generally evaluated in planar structures, while the porous titanium implants have complex 3 dimensional (3D) architectures. In this study, the determining factors for soft tissue integration of 3D porous titanium implants were investigated as a function of surface treatments via quantification of the interaction of serum proteins and cells with single titanium microbeads (300-500 μm in diameter). Samples were either acid etched or nanostructured by anodization. When the samples are used in 3D configuration (porous titanium discs of 2 mm thickness) in vivo (in subcutis of rats for 2 weeks), a better integration was observed for both anodized and acid etched samples compared to the non-treated implants. If the implants were also pre-treated with rat serum before implantation, the integration was further facilitated. In order to understand the underlying reasons for this effect, human fibroblast cell culture tests under several conditions (directly on beads, beads in suspension, beads encapsulated in gelatin hydrogels) were conducted to mimic the different interactions of cells with Ti implants in vivo. Physical characterization showed that surface treatments increased hydrophilicity, protein adsorption and roughness. Surface treatments also resulted in improved adsorption of serum albumin which in turn facilitated the adsorption of other proteins such as apolipoprotein as quantified by protein sequencing. The cellular response to the beads showed considerable difference with respect to the cell culture configuration. When the titanium microbeads were entrapped in cell

  8. A neural model of 3D shape-from-texture: multiple-scale filtering, boundary grouping, and surface filling-in.

    PubMed

    Grossberg, Stephen; Kuhlmann, Levin; Mingolla, Ennio

    2007-03-01

    A neural model is presented of how cortical areas V1, V2, and V4 interact to convert a textured 2D image into a representation of curved 3D shape. Two basic problems are solved to achieve this: (1) Patterns of spatially discrete 2D texture elements are transformed into a spatially smooth surface representation of 3D shape. (2) Changes in the statistical properties of texture elements across space induce the perceived 3D shape of this surface representation. This is achieved in the model through multiple-scale filtering of a 2D image, followed by a cooperative-competitive grouping network that coherently binds texture elements into boundary webs at the appropriate depths using a scale-to-depth map and a subsequent depth competition stage. These boundary webs then gate filling-in of surface lightness signals in order to form a smooth 3D surface percept. The model quantitatively simulates challenging psychophysical data about perception of prolate ellipsoids [Todd, J., & Akerstrom, R. (1987). Perception of three-dimensional form from patterns of optical texture. Journal of Experimental Psychology: Human Perception and Performance, 13(2), 242-255]. In particular, the model represents a high degree of 3D curvature for a certain class of images, all of whose texture elements have the same degree of optical compression, in accordance with percepts of human observers. Simulations of 3D percepts of an elliptical cylinder, a slanted plane, and a photo of a golf ball are also presented.

  9. Development of portable 3D optical measuring system using structured light projection method

    NASA Astrophysics Data System (ADS)

    Aoki, Hiroshi

    2014-05-01

    Three-dimensional (3D) scanners are becoming increasingly common in many industries. However most of these scanning technologies have drawbacks for practical use due to size, weight, accessibility, and ease-of-use. Depending on the application, speed, flexibility and portability can often be deemed more important than accuracy. We have developed a solution to address this market requirement and overcome the aforementioned limitations. To counteract shortcomings such as heavy weight and large size, an optical sensor is used that consists of a laser projector, a camera system, and a multi-touch screen. Structured laser light is projected onto the measured object with a newly designed laser projector employing a single Micro Electro Mechanical Systems (MEMS) mirror. The optical system is optimized for the combination of a Laser Diode (LD), the MEMS mirror and the size of measurement area to secure the ideal contrast of structured light. Also, we developed a new calibration algorithm for this sensor with MEMS laser projector that uses an optical camera model for point cloud calculation. These technical advancements make the sensor compact, save power consumption, and reduce heat generation yet still allows for rapid calculation. Due to the principle of the measurement, structured light triangulation utilizing phase-shifting technology, resolution is improved. To meet requirements for practical applications, the optics, electronics, image processing, display and data management capabilities have been integrated into a single compact unit.

  10. Fiber based optical tweezers for simultaneous in situ force exertion and measurements in a 3D polyacrylamide gel compartment.

    PubMed

    Ti, Chaoyang; Thomas, Gawain M; Ren, Yundong; Zhang, Rui; Wen, Qi; Liu, Yuxiang

    2015-07-01

    Optical tweezers play an important role in biological applications. However, it is difficult for traditional optical tweezers based on objective lenses to work in a three-dimensional (3D) solid far away from the substrate. In this work, we develop a fiber based optical trapping system, namely inclined dual fiber optical tweezers, that can simultaneously apply and measure forces both in water and in a 3D polyacrylamide gel matrix. In addition, we demonstrate in situ, non-invasive characterization of local mechanical properties of polyacrylamide gel by measurements on an embedded bead. The fiber optical tweezers measurements agree well with those of atomic force microscopy (AFM). The inclined dual fiber optical tweezers provide a promising and versatile tool for cell mechanics study in 3D environments.

  11. Fiber based optical tweezers for simultaneous in situ force exertion and measurements in a 3D polyacrylamide gel compartment

    PubMed Central

    Ti, Chaoyang; Thomas, Gawain M; Ren, Yundong; Zhang, Rui; Wen, Qi; Liu, Yuxiang

    2015-01-01

    Optical tweezers play an important role in biological applications. However, it is difficult for traditional optical tweezers based on objective lenses to work in a three-dimensional (3D) solid far away from the substrate. In this work, we develop a fiber based optical trapping system, namely inclined dual fiber optical tweezers, that can simultaneously apply and measure forces both in water and in a 3D polyacrylamide gel matrix. In addition, we demonstrate in situ, non-invasive characterization of local mechanical properties of polyacrylamide gel by measurements on an embedded bead. The fiber optical tweezers measurements agree well with those of atomic force microscopy (AFM). The inclined dual fiber optical tweezers provide a promising and versatile tool for cell mechanics study in 3D environments. PMID:26203364

  12. A Generalized Approach to the Modeling and Analysis of 3D Surface Morphology in Organisms

    PubMed Central

    Pappas, Janice L.; Miller, Daniel J.

    2013-01-01

    The surface geometry of an organism represents the boundary of its three-dimensional (3D) form and can be used as a proxy for the phenotype. A mathematical approach is presented that describes surface morphology using parametric 3D equations with variables expressed as x, y, z in terms of parameters u, v. Partial differentiation of variables with respect to parameters yields elements of the Jacobian representing tangent lines and planes of every point on the surface. Jacobian elements provide a compact size-free summary of the entire surface, and can be used as variables in principal components analysis to produce a morphospace. Mollusk and echinoid models are generated to demonstrate that whole organisms can be represented in a common morphospace, regardless of differences in size, geometry, and taxonomic affinity. Models can be used to simulate theoretical forms, novel morphologies, and patterns of phenotypic variation, and can also be empirically-based by designing them with reference to actual forms using reverse engineering principles. Although this study uses the Jacobian to summarize models, they can also be analyzed with 3D methods such as eigensurface, spherical harmonics, wavelet analysis, and geometric morphometrics. This general approach should prove useful for exploring broad questions regarding morphological evolution and variation. PMID:24204866

  13. Illustrating Surface Shape in Volume Data via Principal Direction-Driven 3D Line Integral Convolution

    NASA Technical Reports Server (NTRS)

    Interrante, Victoria

    1997-01-01

    The three-dimensional shape and relative depth of a smoothly curving layered transparent surface may be communicated particularly effectively when the surface is artistically enhanced with sparsely distributed opaque detail. This paper describes how the set of principal directions and principal curvatures specified by local geometric operators can be understood to define a natural 'flow' over the surface of an object, and can be used to guide the placement of the lines of a stroke texture that seeks to represent 3D shape information in a perceptually intuitive way. The driving application for this work is the visualization of layered isovalue surfaces in volume data, where the particular identity of an individual surface is not generally known a priori and observers will typically wish to view a variety of different level surfaces from the same distribution, superimposed over underlying opaque structures. By advecting an evenly distributed set of tiny opaque particles, and the empty space between them, via 3D line integral convolution through the vector field defined by the principal directions and principal curvatures of the level surfaces passing through each gridpoint of a 3D volume, it is possible to generate a single scan-converted solid stroke texture that may intuitively represent the essential shape information of any level surface in the volume. To generate longer strokes over more highly curved areas, where the directional information is both most stable and most relevant, and to simultaneously downplay the visual impact of directional information in the flatter regions, one may dynamically redefine the length of the filter kernel according to the magnitude of the maximum principal curvature of the level surface at the point around which it is applied.

  14. Towards a noninvasive intracranial tumor irradiation using 3d optical imaging and multimodal data registration.

    PubMed

    Posada, R; Daul, Ch; Wolf, D; Aletti, P

    2007-01-01

    Conformal radiotherapy (CRT) results in high-precision tumor volume irradiation. In fractioned radiotherapy (FRT), lesions are irradiated in several sessions so that healthy neighbouring tissues are better preserved than when treatment is carried out in one fraction. In the case of intracranial tumors, classical methods of patient positioning in the irradiation machine coordinate system are invasive and only allow for CRT in one irradiation session. This contribution presents a noninvasive positioning method representing a first step towards the combination of CRT and FRT. The 3D data used for the positioning is point clouds spread over the patient's head (CT-data usually acquired during treatment) and points distributed over the patient's face which are acquired with a structured light sensor fixed in the therapy room. The geometrical transformation linking the coordinate systems of the diagnosis device (CT-modality) and the 3D sensor of the therapy room (visible light modality) is obtained by registering the surfaces represented by the two 3D point sets. The geometrical relationship between the coordinate systems of the 3D sensor and the irradiation machine is given by a calibration of the sensor position in the therapy room. The global transformation, computed with the two previous transformations, is sufficient to predict the tumor position in the irradiation machine coordinate system with only the corresponding position in the CT-coordinate system. Results obtained for a phantom show that the mean positioning error of tumors on the treatment machine isocentre is 0.4 mm. Tests performed with human data proved that the registration algorithm is accurate (0.1 mm mean distance between homologous points) and robust even for facial expression changes.

  15. Algorithms for Accurate and Fast Plotting of Contour Surfaces in 3D Using Hexahedral Elements

    NASA Astrophysics Data System (ADS)

    Singh, Chandan; Saini, Jaswinder Singh

    2016-07-01

    In the present study, Fast and accurate algorithms for the generation of contour surfaces in 3D are described using hexahedral elements which are popular in finite element analysis. The contour surfaces are described in the form of groups of boundaries of contour segments and their interior points are derived using the contour equation. The locations of contour boundaries and the interior points on contour surfaces are as accurate as the interpolation results obtained by hexahedral elements and thus there are no discrepancies between the analysis and visualization results.

  16. 3D scanning electron microscopy applied to surface characterization of fluorosed dental enamel.

    PubMed

    Limandri, Silvina; Galván Josa, Víctor; Valentinuzzi, María Cecilia; Chena, María Emilia; Castellano, Gustavo

    2016-05-01

    The enamel surfaces of fluorotic teeth were studied by scanning electron stereomicroscopy. Different whitening treatments were applied to 25 pieces to remove stains caused by fluorosis and their surfaces were characterized by stereomicroscopy in order to obtain functional and amplitude parameters. The topographic features resulting for each treatment were determined through these parameters. The results obtained show that the 3D reconstruction achieved from the SEM stereo pairs is a valuable potential alternative for the surface characterization of this kind of samples. PMID:26930005

  17. Scanning all-fiber-optic endomicroscopy system for 3D nonlinear optical imaging of biological tissues

    PubMed Central

    Wu, Yicong; Leng, Yuxin; Xi, Jiefeng; Li, Xingde

    2009-01-01

    An extremely compact all-fiber-optic scanning endomicroscopy system was developed for two-photon fluorescence (TPF) and second harmonic generation (SHG) imaging of biological samples. A conventional double-clad fiber (DCF) was employed in the endomicroscope for single-mode femtosecond pulse delivery, multimode nonlinear optical signals collection and fast two-dimensional scanning. A single photonic bandgap fiber (PBF) with negative group velocity dispersion at two-photon excitation wavelength (i.e. ~810 nm) was used for pulse prechirping in replacement of a bulky grating/lens-based pulse stretcher. The combined use of DCF and PBF in the endomicroscopy system made the endomicroscope basically a plug-and-play unit. The excellent imaging ability of the extremely compact all-fiber-optic nonlinear optical endomicroscopy system was demonstrated by SHG imaging of rat tail tendon and depth-resolved TPF imaging of epithelial tissues stained with acridine orange. The preliminary results suggested the promising potential of this extremely compact all-fiber-optic endomicroscopy system for real-time assessment of both epithelial and stromal structures in luminal organs. PMID:19434122

  18. Importance of a 3D forward modeling tool for surface wave analysis methods

    NASA Astrophysics Data System (ADS)

    Pageot, Damien; Le Feuvre, Mathieu; Donatienne, Leparoux; Philippe, Côte; Yann, Capdeville

    2016-04-01

    Since a few years, seismic surface waves analysis methods (SWM) have been widely developed and tested in the context of subsurface characterization and have demonstrated their effectiveness for sounding and monitoring purposes, e.g., high-resolution tomography of the principal geological units of California or real time monitoring of the Piton de la Fournaise volcano. Historically, these methods are mostly developed under the assumption of semi-infinite 1D layered medium without topography. The forward modeling is generally based on Thomson-Haskell matrix based modeling algorithm and the inversion is driven by Monte-Carlo sampling. Given their efficiency, SWM have been transfered to several scale of which civil engineering structures in order to, e.g., determine the so-called V s30 parameter or assess other critical constructional parameters in pavement engineering. However, at this scale, many structures may often exhibit 3D surface variations which drastically limit the efficiency of SWM application. Indeed, even in the case of an homogeneous structure, 3D geometry can bias the dispersion diagram of Rayleigh waves up to obtain discontinuous phase velocity curves which drastically impact the 1D mean velocity model obtained from dispersion inversion. Taking advantages of high-performance computing center accessibility and wave propagation modeling algorithm development, it is now possible to consider the use of a 3D elastic forward modeling algorithm instead of Thomson-Haskell method in the SWM inversion process. We use a parallelized 3D elastic modeling code based on the spectral element method which allows to obtain accurate synthetic data with very low numerical dispersion and a reasonable numerical cost. In this study, we choose dike embankments as an illustrative example. We first show that their longitudinal geometry may have a significant effect on dispersion diagrams of Rayleigh waves. Then, we demonstrate the necessity of 3D elastic modeling as a forward

  19. Surface and curve skeletonization of large 3D models on the GPU.

    PubMed

    Jalba, Andrei C; Kustra, Jacek; Telea, Alexandru C

    2013-06-01

    We present a GPU-based framework for extracting surface and curve skeletons of 3D shapes represented as large polygonal meshes. We use an efficient parallel search strategy to compute point-cloud skeletons and their distance and feature transforms (FTs) with user-defined precision. We regularize skeletons by a new GPU-based geodesic tracing technique which is orders of magnitude faster and more accurate than comparable techniques. We reconstruct the input surface from skeleton clouds using a fast and accurate image-based method. We also show how to reconstruct the skeletal manifold structure as a polygon mesh and the curve skeleton as a polyline. Compared to recent skeletonization methods, our approach offers two orders of magnitude speed-up, high-precision, and low-memory footprints. We demonstrate our framework on several complex 3D models.

  20. Direct ambient noise tomography for 3-D near surface shear velocity structure: methodology and applications

    NASA Astrophysics Data System (ADS)

    Yao, H.; Fang, H.; Li, C.; Liu, Y.; Zhang, H.; van der Hilst, R. D.; Huang, Y. C.

    2014-12-01

    Ambient noise tomography has provided essential constraints on crustal and uppermost mantle shear velocity structure in global seismology. Recent studies demonstrate that high frequency (e.g., ~ 1 Hz) surface waves between receivers at short distances can be successfully retrieved from ambient noise cross-correlation and then be used for imaging near surface or shallow crustal shear velocity structures. This approach provides important information for strong ground motion prediction in seismically active area and overburden structure characterization in oil and gas fields. Here we propose a new tomographic method to invert all surface wave dispersion data for 3-D variations of shear wavespeed without the intermediate step of phase or group velocity maps.The method uses frequency-dependent propagation paths and a wavelet-based sparsity-constrained tomographic inversion. A fast marching method is used to compute, at each period, surface wave traveltimes and ray paths between sources and receivers. This avoids the assumption of great-circle propagation that is used in most surface wave tomographic studies, but which is not appropriate in complex media. The wavelet coefficients of the velocity model are estimated with an iteratively reweighted least squares (IRLS) algorithm, and upon iterations the surface wave ray paths and the data sensitivity matrix are updated from the newly obtained velocity model. We apply this new method to determine the 3-D near surface wavespeed variations in the Taipei basin of Taiwan, Hefei urban area and a shale and gas production field in China using the high-frequency interstation Rayleigh wave dispersion data extracted from ambient noisecross-correlation. The results reveal strong effects of off-great-circle propagation of high-frequency surface waves in these regions with above 30% shear wavespeed variations. The proposed approach is more efficient and robust than the traditional two-step surface wave tomography for imaging complex

  1. From 2D Mesoscale Surface Expressions to 3D Upper Ocean Dynamics

    NASA Astrophysics Data System (ADS)

    Johannessen, J. A.; Chapron, B.; Kudryavtsev, V.; Collard, F.

    2013-03-01

    This paper discusses the establishment of a new framework for synergetic use of satellite data. The motivation is to advance the understanding and ability to more consistently transfer the 2-dimensional (2D) satellite observations of the surface expressions of mesoscale to submesoscale features in the upper ocean to 3D upper ocean dynamics. This will strongly capitalize on both existing and approved high resolution and coarser resolution satellite data in synergy with high quality in-situ data and reliable ocean models.

  2. 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.

  3. Dephasing effect on backscattering of helical surface states in 3D topological insulators.

    PubMed

    Liu, Haiwen; Jiang, Hua; Sun, Qing-Feng; Xie, X C

    2014-07-25

    We analyze the dephasing effect on the backscattering behavior of the helical surface states in 3D topological insulators. We show that the combination of dephasing and impurity scattering can cause backscattering in the helical states. Especially for the charge impurity case, the backscattering cross section becomes extremely large around the Dirac point. This large backscattering behavior can lead to the anomalous "gaplike" features found in recent experiments [T. Sato et al., Nat. Phys. 7, 840 (2011)].

  4. Using 3D Printers to Model Earth Surface Topography for Increased Student Understanding and Retention

    NASA Astrophysics Data System (ADS)

    Thesenga, David; Town, James

    2014-05-01

    In February 2000, the Space Shuttle Endeavour flew a specially modified radar system during an 11-day mission. The purpose of the multinational Shuttle Radar Topography Mission (SRTM) was to "obtain elevation data on a near-global scale to generate the most complete high-resolution digital topographic database of Earth" by using radar interferometry. The data and resulting products are now publicly available for download and give a view of the landscape removed of vegetation, buildings, and other structures. This new view of the Earth's topography allows us to see previously unmapped or poorly mapped regions of the Earth as well as providing a level of detail that was previously unknown using traditional topographic mapping techniques. Understanding and appreciating the geographic terrain is a complex but necessary requirement for middle school aged (11-14yo) students. Abstract in nature, topographic maps and other 2D renderings of the Earth's surface and features do not address the inherent spatial challenges of a concrete-learner and traditional methods of teaching can at times exacerbate the problem. Technological solutions such as 3D-imaging in programs like Google Earth are effective but lack the tactile realness that can make a large difference in learning comprehension and retention for these young students. First developed in the 1980's, 3D printers were not commercial reality until recently and the rapid rise in interest has driven down the cost. With the advent of sub US1500 3D printers, this technology has moved out of the high-end marketplace and into the local office supply store. Schools across the US and elsewhere in the world are adding 3D printers to their technological workspaces and students have begun rapid-prototyping and manufacturing a variety of projects. This project attempted to streamline the process of transforming SRTM data from a GeoTIFF format by way of Python code. The resulting data was then inputted into a CAD-based program for

  5. Modeling of 3d Space-time Surface of Potential Fields and Hydrogeologic Modeling of Nuclear Waste Disposal Sites

    NASA Astrophysics Data System (ADS)

    Shestopalov, V.; Bondarenko, Y.; Zayonts, I.; Rudenko, Y.

    Introduction After the Chernobyl Nuclear Power Plant (CNPP) disaster (04.26.1986) a huge amount (over 2000 sq. km) of nuclear wastes appeared within so-called "Cher- nobyl Exclusion Zone" (CEZ). At present there are not enough storage facilities in the Ukraine for safe disposal of nuclear wastes and hazardous chemical wastes. The urgent problem now is safe isolation of these dangerous wastes. According to the developed state program of radioactive waste management, the construction of a na- tional storage facility of nuclear wastes is planned. It is also possible to create regional storage facilities for hazardous chemical wastes. The region of our exploration cov- ers the eastern part of the Korosten Plutone and its slope, reaching the CNPP. 3D Space-Time Surface Imaging of Geophysical Fields. There are only three direct meth- ods of stress field reconstruction in present practice, namely the field investigations based on the large-scale fracturing tests, petrotectonic and optical polarization meth- ods. Unfortunately, all these methods are extremely laborious and need the regular field tests, which is difficult to conduct in the areas of anisotropic rock outcrops. A compilation of magnetic and gravity data covering the CNPP area was carried out as a prelude to an interpretation study. More than thirty map products were generated from magnetic, gravity and geodesy data to prepare the 3D Space-Time Surface Images (3D STSI). Multi-layer topography and geophysic surfaces included: total magnetic intensity, isostatically-corrected Bouguer gravity, aspect and slope, first and second derivatives, vertical and horizontal curvature, histogram characteristics and space cor- relation coefficients between the gradient fields. Many maps shows the first and sec- ond derivatives of the potential fields, with the results of lineament (edge) structure detection superimposed. The lineament or edges of the potential fields are located from maximal gradient in many directions

  6. 3D active surfaces for liver segmentation in multisequence MRI images.

    PubMed

    Bereciartua, Arantza; Picon, Artzai; Galdran, Adrian; Iriondo, Pedro

    2016-08-01

    Biopsies for diagnosis can sometimes be replaced by non-invasive techniques such as CT and MRI. Surgeons require accurate and efficient methods that allow proper segmentation of the organs in order to ensure the most reliable intervention planning. Automated liver segmentation is a difficult and open problem where CT has been more widely explored than MRI. MRI liver segmentation represents a challenge due to the presence of characteristic artifacts, such as partial volumes, noise and low contrast. In this paper, we present a novel method for multichannel MRI automatic liver segmentation. The proposed method consists of the minimization of a 3D active surface by means of the dual approach to the variational formulation of the underlying problem. This active surface evolves over a probability map that is based on a new compact descriptor comprising spatial and multisequence information which is further modeled by means of a liver statistical model. This proposed 3D active surface approach naturally integrates volumetric regularization in the statistical model. The advantages of the compact visual descriptor together with the proposed approach result in a fast and accurate 3D segmentation method. The method was tested on 18 healthy liver studies and results were compared to a gold standard made by expert radiologists. Comparisons with other state-of-the-art approaches are provided by means of nine well established quality metrics. The obtained results improve these methodologies, achieving a Dice Similarity Coefficient of 98.59. PMID:27282235

  7. Feature, design intention and constraint preservation for direct modeling of 3D freeform surfaces

    NASA Astrophysics Data System (ADS)

    Fu, Luoting; Kara, Levent Burak; Shimada, Kenji

    2012-06-01

    Direct modeling has recently emerged as a suitable approach for 3D free-form shape modeling in industrial design. It has several advantages over the conventional, parametric modeling techniques, including natural user interactions, as well as the underlying, automatic feature-preserving shape deformation algorithms. However, current direct modeling packages still lack several capabilities critical for product design, such as managing aesthetic design intentions, and enforcing dimensional, geometric constraints. In this paper, we describe a novel 3D surface editing system capable of jointly accommodating aesthetic design intentions expressed in the form of surface painting and color-coded annotations, as well as engineering constraints expressed as dimensions. The proposed system is built upon differential coordinates and constrained least squares, and is intended for conceptual design that involves frequent shape tuning and explorations. We also provide an extensive review of the state-of-the-art direct modeling approaches for 3D mesh-based, freeform surfaces, with an emphasis on the two broad categories of shape deformation algorithms developed in the relevant field of geometric modeling. [Figure not available: see fulltext.

  8. 3D surface scan of biological samples with a Push-broom Imaging Spectrometer

    NASA Astrophysics Data System (ADS)

    Yao, Haibo; Kincaid, Russell; Hruska, Zuzana; Brown, Robert L.; Bhatnagar, Deepak; Cleveland, Thomas E.

    2013-08-01

    The food industry is always on the lookout for sensing technologies for rapid and nondestructive inspection of food products. Hyperspectral imaging technology integrates both imaging and spectroscopy into unique imaging sensors. Its application for food safety and quality inspection has made significant progress in recent years. Specifically, hyperspectral imaging has shown its potential for surface contamination detection in many food related applications. Most existing hyperspectral imaging systems use pushbroom scanning which is generally used for flat surface inspection. In some applications it is desirable to be able to acquire hyperspectral images on circular objects such as corn ears, apples, and cucumbers. Past research describes inspection systems that examine all surfaces of individual objects. Most of these systems did not employ hyperspectral imaging. These systems typically utilized a roller to rotate an object, such as an apple. During apple rotation, the camera took multiple images in order to cover the complete surface of the apple. The acquired image data lacked the spectral component present in a hyperspectral image. This paper discusses the development of a hyperspectral imaging system for a 3-D surface scan of biological samples. The new instrument is based on a pushbroom hyperspectral line scanner using a rotational stage to turn the sample. The system is suitable for whole surface hyperspectral imaging of circular objects. In addition to its value to the food industry, the system could be useful for other applications involving 3-D surface inspection.

  9. 3D optical coherence tomography image registration for guiding cochlear implant insertion

    NASA Astrophysics Data System (ADS)

    Cheon, Gyeong-Woo; Jeong, Hyun-Woo; Chalasani, Preetham; Chien, Wade W.; Iordachita, Iulian; Taylor, Russell; Niparko, John; Kang, Jin U.

    2014-03-01

    In cochlear implant surgery, an electrode array is inserted into the cochlear canal to restore hearing to a person who is profoundly deaf or significantly hearing impaired. One critical part of the procedure is the insertion of the electrode array, which looks like a thin wire, into the cochlear canal. Although X-ray or computed tomography (CT) could be used as a reference to evaluate the pathway of the whole electrode array, there is no way to depict the intra-cochlear canal and basal turn intra-operatively to help guide insertion of the electrode array. Optical coherent tomography (OCT) is a highly effective way of visualizing internal structures of cochlea. Swept source OCT (SSOCT) having center wavelength of 1.3 micron and 2D Galvonometer mirrors was used to achieve 7-mm depth 3-D imaging. Graphics processing unit (GPU), OpenGL, C++ and C# were integrated for real-time volumetric rendering simultaneously. The 3D volume images taken by the OCT system were assembled and registered which could be used to guide a cochlear implant. We performed a feasibility study using both dry and wet temporal bones and the result is presented.

  10. Assessment of Ulcer Wounds Size Using 3D Skin Surface Imaging

    NASA Astrophysics Data System (ADS)

    Hani, Ahmad Fadzil M.; Eltegani, Nejood M.; Hussein, Suraiya H.; Jamil, Adawiyah; Gill, Priya

    In this work 3D surface scans of wounds are used to obtain several measurement including wound top area, true surface area (rue area), depth, and volume for the purpose of assessing the progress of ulcer wounds throughout treatment. KONICA MINOLTA 910 laser scanner is used to obtain the surface scans. The algorithm for estimating top area and true surface area from surface scan can reduce the inaccuracy that might result when using manual method. Two methods for solid construction and volume computation were considered; namely mid-point projection and convex hull approximation (Delaunay tetrahedralization). The performance of convex hull approximation method for volume estimation is improved by performing surface subdivision prior to the approximation. The performance of these algorithms on different patterns of simulated wound models is presented. Furthermore the algorithms are tested in two molded wounds printed using rapid prototyping (RP) technique.

  11. Particle-based optical pressure sensors for 3D pressure mapping.

    PubMed

    Banerjee, Niladri; Xie, Yan; Chalaseni, Sandeep; Mastrangelo, Carlos H

    2015-10-01

    This paper presents particle-based optical pressure sensors for in-flow pressure sensing, especially for microfluidic environments. Three generations of pressure sensitive particles have been developed- flat planar particles, particles with integrated retroreflectors and spherical microballoon particles. The first two versions suffer from pressure measurement dependence on particles orientation in 3D space and angle of interrogation. The third generation of microspherical particles with spherical symmetry solves these problems making particle-based manometry in microfluidic environment a viable and efficient methodology. Static and dynamic pressure measurements have been performed in liquid medium for long periods of time in a pressure range of atmospheric to 40 psi. Spherical particles with radius of 12 μm and balloon-wall thickness of 0.5 μm are effective for more than 5 h in this pressure range with an error of less than 5%.

  12. 3D optical phase reconstruction within PMMA samples using a spectral OCT system

    NASA Astrophysics Data System (ADS)

    Briones-R., Manuel d. J.; De La Torre-Ibarra, Manuel H.; Mendoza Santoyo, Fernando

    2015-08-01

    The optical coherence tomography (OCT) technique has proved to be a useful method in biomedical areas such as ophthalmology, dentistry, dermatology, among many others. In all these applications the main target is to reconstruct the internal structure of the samples from which the physician's expertise may recognize and diagnose the existence of a disease. Nowadays OCT has been applied one step further and is used to study the mechanics of some particular type of materials, where the resulting information involves more than just their internal structure and the measurement of parameters such as displacements, stress and strain. Here we report on a spectral OCT system used to image the internal 3D microstructure and displacement maps from a PMMA (Poly-methyl-methacrylate) sample, subjected to a deformation by a controlled three point bending and tilting. The internal mechanical response of the polymer is shown as consecutive 2D images.

  13. Holographic microscopy and microfluidics platform for measuring wall stress and 3D flow over surfaces textured by micro-pillars

    PubMed Central

    Bocanegra Evans, Humberto; Gorumlu, Serdar; Aksak, Burak; Castillo, Luciano; Sheng, Jian

    2016-01-01

    Understanding how fluid flow interacts with micro-textured surfaces is crucial for a broad range of key biological processes and engineering applications including particle dispersion, pathogenic infections, and drag manipulation by surface topology. We use high-speed digital holographic microscopy (DHM) in combination with a correlation based de-noising algorithm to overcome the optical interference generated by surface roughness and to capture a large number of 3D particle trajectories in a microfluidic channel with one surface patterned with micropillars. It allows us to obtain a 3D ensembled velocity field with an uncertainty of 0.06% and 2D wall shear stress distribution at the resolution of ~65 μPa. Contrary to laminar flow in most microfluidics, we find that the flow is three-dimensional and complex for the textured microchannel. While the micropillars affect the velocity flow field locally, their presence is felt globally in terms of wall shear stresses at the channel walls. These findings imply that micro-scale mixing and wall stress sensing/manipulation can be achieved through hydro-dynamically smooth but topologically rough micropillars. PMID:27353632

  14. Holographic microscopy and microfluidics platform for measuring wall stress and 3D flow over surfaces textured by micro-pillars

    NASA Astrophysics Data System (ADS)

    Bocanegra Evans, Humberto; Gorumlu, Serdar; Aksak, Burak; Castillo, Luciano; Sheng, Jian

    2016-06-01

    Understanding how fluid flow interacts with micro-textured surfaces is crucial for a broad range of key biological processes and engineering applications including particle dispersion, pathogenic infections, and drag manipulation by surface topology. We use high-speed digital holographic microscopy (DHM) in combination with a correlation based de-noising algorithm to overcome the optical interference generated by surface roughness and to capture a large number of 3D particle trajectories in a microfluidic channel with one surface patterned with micropillars. It allows us to obtain a 3D ensembled velocity field with an uncertainty of 0.06% and 2D wall shear stress distribution at the resolution of ~65 μPa. Contrary to laminar flow in most microfluidics, we find that the flow is three-dimensional and complex for the textured microchannel. While the micropillars affect the velocity flow field locally, their presence is felt globally in terms of wall shear stresses at the channel walls. These findings imply that micro-scale mixing and wall stress sensing/manipulation can be achieved through hydro-dynamically smooth but topologically rough micropillars.

  15. Intra-retinal layer segmentation of 3D optical coherence tomography using coarse grained diffusion map

    PubMed Central

    Kafieh, Raheleh; Rabbani, Hossein; Abramoff, Michael D.; Sonka, Milan

    2013-01-01

    Optical coherence tomography (OCT) is a powerful and noninvasive method for retinal imaging. In this paper, we introduce a fast segmentation method based on a new variant of spectral graph theory named diffusion maps. The research is performed on spectral domain (SD) OCT images depicting macular and optic nerve head appearance. The presented approach does not require edge-based image information in localizing most of boundaries and relies on regional image texture. Consequently, the proposed method demonstrates robustness in situations of low image contrast or poor layer-to-layer image gradients. Diffusion mapping applied to 2D and 3D OCT datasets is composed of two steps, one for partitioning the data into important and less important sections, and another one for localization of internal layers. In the first step, the pixels/voxels are grouped in rectangular/cubic sets to form a graph node. The weights of the graph are calculated based on geometric distances between pixels/voxels and differences of their mean intensity. The first diffusion map clusters the data into three parts, the second of which is the area of interest. The other two sections are eliminated from the remaining calculations. In the second step, the remaining area is subjected to another diffusion map assessment and the internal layers are localized based on their textural similarities. The proposed method was tested on 23 datasets from two patient groups (glaucoma and normals). The mean unsigned border positioning errors (mean ± SD) was 8.52 ± 3.13 and 7.56 ± 2.95 μm for the 2D and 3D methods, respectively. PMID:23837966

  16. Defining an optimal surface chemistry for pluripotent stem cell culture in 2D and 3D

    NASA Astrophysics Data System (ADS)

    Zonca, Michael R., Jr.

    Surface chemistry is critical for growing pluripotent stem cells in an undifferentiated state. There is great potential to engineer the surface chemistry at the nanoscale level to regulate stem cell adhesion. However, the challenge is to identify the optimal surface chemistry of the substrata for ES cell attachment and maintenance. Using a high-throughput polymerization and screening platform, a chemically defined, synthetic polymer grafted coating that supports strong attachment and high expansion capacity of pluripotent stem cells has been discovered using mouse embryonic stem (ES) cells as a model system. This optimal substrate, N-[3-(Dimethylamino)propyl] methacrylamide (DMAPMA) that is grafted on 2D synthetic poly(ether sulfone) (PES) membrane, sustains the self-renewal of ES cells (up to 7 passages). DMAPMA supports cell attachment of ES cells through integrin beta1 in a RGD-independent manner and is similar to another recently reported polymer surface. Next, DMAPMA has been able to be transferred to 3D by grafting to synthetic, polymeric, PES fibrous matrices through both photo-induced and plasma-induced polymerization. These 3D modified fibers exhibited higher cell proliferation and greater expression of pluripotency markers of mouse ES cells than 2D PES membranes. Our results indicated that desirable surfaces in 2D can be scaled to 3D and that both surface chemistry and structural dimension strongly influence the growth and differentiation of pluripotent stem cells. Lastly, the feasibility of incorporating DMAPMA into a widely used natural polymer, alginate, has been tested. Novel adhesive alginate hydrogels have been successfully synthesized by either direct polymerization of DMAPMA and methacrylic acid blended with alginate, or photo-induced DMAPMA polymerization on alginate nanofibrous hydrogels. In particular, DMAPMA-coated alginate hydrogels support strong ES cell attachment, exhibiting a concentration dependency of DMAPMA. This research provides a

  17. Surface states in a 3D topological insulator: The role of hexagonal warping and curvature

    SciTech Connect

    Repin, E. V.; Burmistrov, I. S.

    2015-09-15

    We explore a combined effect of hexagonal warping and a finite effective mass on both the tunneling density of electronic surface states and the structure of Landau levels of 3D topological insulators. We find the increasing warping to transform the square-root van Hove singularity into a logarithmic one. For moderate warping, an additional logarithmic singularity and a jump in the tunneling density of surface states appear. By combining the perturbation theory and the WKB approximation, we calculate the Landau levels in the presence of hexagonal warping. We predict that due to the degeneracy removal, the evolution of Landau levels in the magnetic field is drastically modified.

  18. Rat Optic Nerve Head Anatomy within 3D Histomorphometric Reconstructions of Normal Control Eyes

    PubMed Central

    Pazos, Marta; Yang, Hongli; Gardiner, Stuart K.; Cepurna, William O.; Johnson, Elaine C.; Morrison, John C.; Burgoyne, Claude F.

    2015-01-01

    The purpose of this study is to three-dimensionally (3D) characterize the principal macroscopic and microscopic relationships within the rat optic nerve head (ONH) and quantify them in normal control eyes. Perfusion-fixed, trephinated ONH from 8 normal control eyes of 8 Brown Norway Rats were 3D histomorphometrically reconstructed, visualized, delineated and parameterized. The rat ONH consists of 2 scleral openings, (a superior neurovascular and inferior arterial) separated by a thin connective tissue strip we have termed the “scleral sling”. Within the superior opening, the nerve abuts a prominent extension of Bruch's Membrane (BM) superiorly and is surrounded by a vascular plexus, as it passes through the sclera, that is a continuous from the choroid into and through the dural sheath and contains the central retinal vein (CRV), (inferiorly). The inferior scleral opening contains the central retinal artery and three long posterior ciliary arteries which obliquely pass through the sclera to obtain the choroid. Bruch's Membrane Opening (BMO) is irregular and vertically elongated, enclosing the nerve (superiorly) and CRV and CRA (inferiorly). Overall mean BMO Depth, BMO Area, Choroidal Thickness and peripapillary Scleral Thickness were 29 μm, 56.5 × 103 μm2, 57 μm and 104 μm respectively. Mean anterior scleral canal opening (ASCO) and posterior scleral canal opening (PSCO) radii were 201 ± 15 μm and 204 ± 16 μm, respectively. Mean optic nerve area at the ASCO and PSCO were 46.3 × 103 ± 4.4 × 103 μm2 and 44.1 × 103 ± 4.5 × 103 μm2 respectively. In conclusion, the 3D complexity of the rat ONH and the extent to which it differs from the primate have been under-appreciated within previous 2D studies. Properly understood, these anatomic differences may provide new insights into the relative susceptibilities of the rat and primate ONH to elevated intraocular pressure. PMID:26021973

  19. SU-E-J-128: 3D Surface Reconstruction of a Patient Using Epipolar Geometry

    SciTech Connect

    Kotoku, J; Nakabayashi, S; Kumagai, S; Ishibashi, T; Kobayashi, T; Haga, A; Saotome, N; Arai, N

    2014-06-01

    Purpose: To obtain a 3D surface data of a patient in a non-invasive way can substantially reduce the effort for the registration of patient in radiation therapy. To achieve this goal, we introduced the multiple view stereo technique, which is known to be used in a 'photo tourism' on the internet. Methods: 70 Images were taken with a digital single-lens reflex camera from different angles and positions. The camera positions and angles were inferred later in the reconstruction step. A sparse 3D reconstruction model was locating by SIFT features, which is robust for rotation and shift variance, in each image. We then found a set of correspondences between pairs of images by computing the fundamental matrix using the eight-point algorithm with RANSAC. After the pair matching, we optimized the parameter including camera positions to minimize the reprojection error by use of bundle adjustment technique (non-linear optimization). As a final step, we performed dense reconstruction and associate a color with each point using the library of PMVS. Results: Surface data were reconstructed well by visual inspection. The human skin is reconstructed well, althogh the reconstruction was time-consuming for direct use in daily clinical practice. Conclusion: 3D reconstruction using multi view stereo geometry is a promising tool for reducing the effort of patient setup. This work was supported by JSPS KAKENHI(25861128)

  20. Magellan 3D perspective of Venus surface in western Eistla Regio

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Magellan synthetic aperture radar data was used to create this three- dimensional (3D) perspective view of Venus' western Eistla Regio. This viewpoint is located at 1,310 kilometers (812 miles) southwest of Gula Mons at an elevation of 0.178 kilometers (0.48 miles). The view is of the northeast with Gula Mons appearing on the horizon. Gula Mons, a 3 kilometer (1.86 mile) high volcano, is located at approximately 22 degrees north latitude, 359 degrees east longitude. The impact crater Cunitz, named for the astronomer and mathematician Maria Cunitz, is visible in the center of the image. The crater is 48.5 kilometers (30 miles) in diameter and is 215 kilometers (133 miles) from the viewer's position. Magellan synthetic aperture radar data is combined with radar altimetry to develop a 3D map of the surface. Rays cast in a computer intersect the surface to create a 3D view. Simulated color and a digital elevation map developed by the United States (U.S.) Geological Survey is used to enhanc

  1. Surface processes on the asteroid deduced from the external 3D shapes and surface features of Itokawa particles

    NASA Astrophysics Data System (ADS)

    Tsuchiyama, A.; Matsumoto, T.

    2015-10-01

    Particles on the surface of S-type Asteroid 25143 Itokawa were successfully recovered by the Hayabusa mission of JAXA (e.g., [1,2]). They are not only the first samples recovered from an asteroid, but also the second extraterrestrial regolith to have been sampled, the first being the Moon by Apollo and Luna missions. The analysis of tiny sample particles (20-200 μm) shows that the Itokawa surface material is consistent with LL chondrites suffered by space weathering as expected and brought an end to the origin of meteorites (e.g., [2-4]). In addition, the examination of Itokawa particles allow studies of surface processes on the asteroid because regolith particles can be regarded as an interface with the space environment, where the impacts of small objects and irradiation by the solar wind and galactic cosmic rays should have been recorded. External 3D shapes and surface features of Itokawa regolith particles were examined. Two kinds of surface modification, formation of space-weathering rims mainly by solar wind implantation and surface abrasion by grain migration, were recognized. Spectral change of the asteroid proceeded by formation of space-weathering rims and refreshment of the regolith surfaces. External 3D shapes and surface morphologies of the regolith particles can provide information about formation and evolution history of regolith particles in relation to asteroidal surface processes. 3D shapes of Itokawa regolith particles were obtained using microtomography [3]. The surface nanomiromorpholgy of Itokawa particles were also observed using FE-SEM [5]. However, the number of particles was limited and genial feature on the surface morphology has not been understood. In this study, the surface morphology of Itokawa regolith particles was systematically investigated together with their 3D structures.

  2. Compact encoding of 3-D voxel surfaces based on pattern code representation.

    PubMed

    Kim, Chang-Su; Lee, Sang-Uk

    2002-01-01

    In this paper, we propose a lossless compression algorithm for three-dimensional (3-D) binary voxel surfaces, based on the pattern code representation (PCR). In PCR, a voxel surface is represented by a series of pattern codes. The pattern of a voxel v is defined as the 3 x 3 x 3 array of voxels, centered on v. Therefore, the pattern code for informs of the local shape of the voxel surface around . The proposed algorithm can achieve the coding gain, since the patterns of adjacent voxels are highly correlated to each other. The performance of the proposed algorithm is evaluated using various voxel surfaces, which are scan-converted from triangular mesh models. It is shown that the proposed algorithm requires only 0.5 approximately 1 bits per black voxel (bpbv) to store or transmit the voxel surfaces.

  3. 3D interferometric microscope: color visualization of engineered surfaces for industrial applications

    NASA Astrophysics Data System (ADS)

    Schmit, Joanna; Novak, Matt; Bui, Son

    2015-09-01

    3D microscopes based on white light interference (WLI) provide precise measurement for the topography of engineering surfaces. However, the display of an object in its true colors as observed under white illumination is often desired; this traditionally has presented a challenge for WLI-based microscopes. Such 3D color display is appealing to the eye and great for presentations, and also provides fast evaluation of certain characteristics like defects, delamination, or deposition of different materials. Determination of color as observed by interferometric objectives is not straightforward; we will present how color imaging capabilities similar to an ordinary microscope can be obtained in interference microscopes based on WLI and we will give measurement and imaging examples of a few industrial samples.

  4. Identification of Fe 3d empty states from the total current spectra of an ?(0001) surface

    NASA Astrophysics Data System (ADS)

    Møller, P. J.; Komolov, S. A.; Lazneva, E. F.

    1996-09-01

    An intensive triplet line is revealed in the total current spectrum (TCS) of a reconstructed 0953-8984/8/36/009/img7 surface. The nature of the observed structure in the TCS is discussed in comparison with previously reported data from photoemission, inverse photoemission and theoretical investigations. It is found to be a consequence of the electron transitions into an Fe 3d band of empty states. Energy locations of Fe 3d-band extrema (0953-8984/8/36/009/img8 and 0953-8984/8/36/009/img9 above the bottom of the conduction band) and its splitting 0953-8984/8/36/009/img10 are estimated from the proposed schemes of electron transitions.

  5. Automated 3-D reconstruction of the surface of live early-stage amphibian embryos.

    PubMed

    Bootsma, Gregory J; Brodland, G Wayne

    2005-08-01

    Although three-dimensional (3-D) reconstructions of the surfaces of live embyos are vital to understanding embryo development, morphogenetic tissue movements and other factors have prevented the automation of this task. Here, we report an integrated set of software algorithms that overcome these challenges, making it possible to completely automate the reconstruction of embryo surfaces and other textured surfaces from multiview images. The process involves: 1) building accurate point correspondences using a robust deformable template block matching algorithm; 2) removing outliers using fundamental matrix calculations in conjunction with a RANSAC algorithm; 3) generating 3-D point clouds using a bundle adjustment algorithm that includes camera position and distortion corrections; 4) meshing the point clouds into triangulated surfaces using a Tight Cocone algorithm that produces water tight models; 5) refining surfaces using midpoint insertion and Laplacian smoothing algorithms; and 6) repeating these steps until a measure of convergence G, the rms difference between successive reconstructions, is below a specified threshold. Reconstructions were made of 2.2-mm diameter, neurulation-stage axolotl (amphibian) embryos using 44 multiview images collected with a robotic microscope. A typical final model (sixth iteration) contained 3787 points and 7562 triangles and had an error measure of G = 5.9 microm.

  6. Maximum likelihood estimation of parameterized 3-D surfaces using a moving camera

    NASA Technical Reports Server (NTRS)

    Hung, Y.; Cernuschi-Frias, B.; Cooper, D. B.

    1987-01-01

    A new approach is introduced to estimating object surfaces in three-dimensional space from a sequence of images. A surface of interest here is modeled as a 3-D function known up to the values of a few parameters. The approach will work with any parameterization. However, in work to date researchers have modeled objects as patches of spheres, cylinders, and planes - primitive objects. These primitive surfaces are special cases of 3-D quadric surfaces. Primitive surface estimation is treated as the general problem of maximum likelihood parameter estimation based on two or more functionally related data sets. In the present case, these data sets constitute a sequence of images taken at different locations and orientations. A simple geometric explanation is given for the estimation algorithm. Though various techniques can be used to implement this nonlinear estimation, researches discuss the use of gradient descent. Experiments are run and discussed for the case of a sphere of unknown location. These experiments graphically illustrate the various advantages of using as many images as possible in the estimation and of distributing camera positions from first to last over as large a baseline as possible. Researchers introduce the use of asymptotic Bayesian approximations in order to summarize the useful information in a sequence of images, thereby drastically reducing both the storage and amount of processing required.

  7. 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.

  8. Color 3D electronic imaging of the surface of the human body

    NASA Astrophysics Data System (ADS)

    Rioux, Marc

    1994-10-01

    The NRC laboratories have developed a laser scanning technique to digitize shapes and colors in registration. The technique, known as synchronized scanning, is capable of digitizing topography as small as the relief of a bare finger tip, showing a clear picture of the skin structure (essentially a clean fingerprint without distortion), as well as the shape and size of body components such as hands, face, and feet, and the full body of one or more subjects simultaneously. The laser scanner uses a RGB laser, coupled to an optical fiber, which is projected in the field of view. The 3D color measurements are made by optical triangulation to a resolution of 10 micrometers for finger tip scans and a resolution of 1 mm for whole body scans. Experimental results are presented and discussed. Potential applications of this technology in the field of identification and inspection of humans include face recognition, finger, foot and teeth print identification, and 3D mugshots that can be rapidly broadcast through satellite communication. One of the unique properties of this technology is that absolute measurements, not only appearance and relative position of features, can be used for identification purposes.

  9. Beyond optical molasses: 3D raman sideband cooling of atomic cesium to high phase-space density

    PubMed

    Kerman; Vuletic; Chin; Chu

    2000-01-17

    We demonstrate a simple, general purpose method to cool neutral atoms. A sample containing 3x10(8) cesium atoms prepared in a magneto-optical trap is cooled and simultaneously spin polarized in 10 ms at a density of 1.1x10(11) cm (-3) to a phase space density nlambda(3)(dB) = 1/500, which is almost 3 orders of magnitude higher than attainable in free space with optical molasses. The technique is based on 3D degenerate Raman sideband cooling in optical lattices and remains efficient even at densities where the mean lattice site occupation is close to unity.

  10. Ab initio study of interaction between 3d adatoms on the vicinal Cu(111) surface

    NASA Astrophysics Data System (ADS)

    Syromyatnikov, A. G.; Kabanov, N. S.; Saletsky, A. M.; Klavsyuk, A. L.

    2016-06-01

    Density functional theory is used to resolve the adatom-step and adatom-adatom interactions on vicinal Cu(111) surface. We demonstrated that the interactions between 3d adatoms appreciably depend on the distance from a surface step. Our calculations show that the magnitude of the repulsive barrier related to the surface step is larger for 3d adatoms located at the upper surface terrace than for adatoms located at the lower surface terrace.

  11. On-machine measurement of the grinding wheels' 3D surface topography using a laser displacement sensor

    NASA Astrophysics Data System (ADS)

    Pan, Yongcheng; Zhao, Qingliang; Guo, Bing

    2014-08-01

    A method of non-contact, on-machine measurement of three dimensional surface topography of grinding wheels' whole surface was developed in this paper, focusing on an electroplated coarse-grained diamond grinding wheel. The measuring system consists of a Keyence laser displacement sensor, a Keyence controller and a NI PCI-6132 data acquisition card. A resolution of 0.1μm in vertical direction and 8μm in horizontal direction could be achieved. After processing the data by LabVIEW and MATLAB, the 3D topography of the grinding wheel's whole surface could be reconstructed. When comparing the reconstructed 3D topography of the grinding wheel's marked area to its real topography captured by a high-depth-field optical digital microscope (HDF-ODM) and scanning electron microscope (SEM), they were very similar to each other, proving that this method is accurate and effective. By a subsequent data processing, the topography of every grain could be extracted and then the active grain number, the active grain volume and the active grain's bearing ration could be calculated. These three parameters could serve as the criterion to evaluate the grinding performance of coarse-grained diamond grinding wheels. Then the performance of the grinding wheel could be evaluated on-machine accurately and quantitatively.

  12. Automatic registration of optical imagery with 3d lidar data using local combined mutual information

    NASA Astrophysics Data System (ADS)

    Parmehr, E. G.; Fraser, C. S.; Zhang, C.; Leach, J.

    2013-10-01

    Automatic registration of multi-sensor data is a basic step in data fusion for photogrammetric and remote sensing applications. The effectiveness of intensity-based methods such as Mutual Information (MI) for automated registration of multi-sensor image has been previously reported for medical and remote sensing applications. In this paper, a new multivariable MI approach that exploits complementary information of inherently registered LiDAR DSM and intensity data to improve the robustness of registering optical imagery and LiDAR point cloud, is presented. LiDAR DSM and intensity information has been utilised in measuring the similarity of LiDAR and optical imagery via the Combined MI. An effective histogramming technique is adopted to facilitate estimation of a 3D probability density function (pdf). In addition, a local similarity measure is introduced to decrease the complexity of optimisation at higher dimensions and computation cost. Therefore, the reliability of registration is improved due to the use of redundant observations of similarity. The performance of the proposed method for registration of satellite and aerial images with LiDAR data in urban and rural areas is experimentally evaluated and the results obtained are discussed.

  13. Label-free optical detection of cells grown in 3D silicon microstructures.

    PubMed

    Merlo, Sabina; Carpignano, Francesca; Silva, Gloria; Aredia, Francesca; Scovassi, A Ivana; Mazzini, Giuliano; Surdo, Salvatore; Barillaro, Giuseppe

    2013-08-21

    We demonstrate high aspect-ratio photonic crystals that could serve as three-dimensional (3D) microincubators for cell culture and also provide label-free optical detection of the cells. The investigated microstructures, fabricated by electrochemical micromachining of standard silicon wafers, consist of periodic arrays of silicon walls separated by narrow deeply etched air-gaps (50 μm high and 5 μm wide) and feature the typical spectral properties of photonic crystals in the wavelength range 1.0-1.7 μm: their spectral reflectivity is characterized by wavelength regions where reflectivity is high (photonic bandgaps), separated by narrow wavelength regions where reflectivity is very low. In this work, we show that the presence of cells, grown inside the gaps, strongly affects light propagation across the photonic crystal and, therefore, its spectral reflectivity. Exploiting a label-free optical detection method, based on a fiberoptic setup, we are able to probe the extension of cells adherent to the vertical silicon walls with a non-invasive direct testing. In particular, the intensity ratio at two wavelengths is the experimental parameter that can be well correlated to the cell spreading on the silicon wall inside the gaps.

  14. In situ 3D characterization of historical coatings and wood using multimodal nonlinear optical microscopy.

    PubMed

    Latour, Gaël; Echard, Jean-Philippe; Didier, Marie; Schanne-Klein, Marie-Claire

    2012-10-22

    We demonstrate multimodal nonlinear optical imaging of historical artifacts by combining Second Harmonic Generation (SHG) and Two-Photon Excited Fluorescence (2PEF) microscopies. We first identify the nonlinear optical response of materials commonly encountered in coatings of cultural heritage artifacts by analyzing one- and multi-layered model samples. We observe 2PEF signals from cochineal lake and sandarac and show that pigments and varnish films can be discriminated by exploiting their different emission spectral ranges as in luminescence linear spectroscopy. We then demonstrate SHG imaging of a filler, plaster, composed of bassanite particles which exhibit a non centrosymmetric crystal structure. We also show that SHG/2PEF imaging enables the visualization of wood microstructure through typically 60 µm-thick coatings by revealing crystalline cellulose (SHG signal) and lignin (2PEF signal) in the wood cell walls. Finally, in situ multimodal nonlinear imaging is demonstrated in a historical violin. SHG/2PEF imaging thus appears as a promising non-destructive and contactless tool for in situ 3D investigation of historical coatings and more generally for wood characterization and coating analysis at micrometer scale. PMID:23187225

  15. Exploring the surface reactivity of 3d metal endofullerenes: a density-functional theory study.

    PubMed

    Estrada-Salas, Rubén E; Valladares, Ariel A

    2009-09-24

    Changes in the preferential sites of electrophilic, nucleophilic, and radical attacks on the pristine C60 surface with endohedral doping using 3d transition metal atoms were studied via two useful reactivity indices, namely the Fukui functions and the molecular electrostatic potential. Both of these were calculated at the density functional BPW91 level of theory with the DNP basis set. Our results clearly show changes in the preferential reactivity sites on the fullerene surface when it is doped with Mn, Fe, Co, or Ni atoms, whereas there are no significant changes in the preferential reactivity sites on the C60 surface upon endohedral doping with Cu and Zn atoms. Electron affinities (EA), ionization potentials (IP), and HOMO-LUMO gaps (Eg) were also calculated to complete the study of the endofullerene's surface reactivity. These findings provide insight into endofullerene functionalization, an important issue in their application.

  16. Automatic segmentation of pulmonary fissures in computed tomography images using 3D surface features.

    PubMed

    Yu, Mali; Liu, Hong; Gong, Jianping; Jin, Renchao; Han, Ping; Song, Enmin

    2014-02-01

    Pulmonary interlobar fissures are important anatomic structures in human lungs and are useful in locating and classifying lung abnormalities. Automatic segmentation of fissures is a difficult task because of their low contrast and large variability. We developed a fully automatic training-free approach for fissure segmentation based on the local bending degree (LBD) and the maximum bending index (MBI). The LBD is determined by the angle between the eigenvectors of two Hessian matrices for a pair of adjacent voxels. It is used to construct a constraint to extract the candidate surfaces in three-dimensional (3D) space. The MBI is a measure to discriminate cylindrical surfaces from planar surfaces in 3D space. Our approach for segmenting fissures consists of five steps, including lung segmentation, plane-like structure enhancement, surface extraction with LBD, initial fissure identification with MBI, and fissure extension based on local plane fitting. When applying our approach to 15 chest computed tomography (CT) scans, the mean values of the positive predictive value, the sensitivity, the root-mean square (RMS) distance, and the maximal RMS are 91 %, 88 %, 1.01 ± 0.99 mm, and 11.56 mm, respectively, which suggests that our algorithm can efficiently segment fissures in chest CT scans.

  17. Real-time 3D Fourier-domain optical coherence tomography guided microvascular anastomosis

    NASA Astrophysics Data System (ADS)

    Huang, Yong; Ibrahim, Zuhaib; Lee, W. P. A.; Brandacher, Gerald; Kang, Jin U.

    2013-03-01

    Vascular and microvascular anastomosis is considered to be the foundation of plastic and reconstructive surgery, hand surgery, transplant surgery, vascular surgery and cardiac surgery. In the last two decades innovative techniques, such as vascular coupling devices, thermo-reversible poloxamers and suture-less cuff have been introduced. Intra-operative surgical guidance using a surgical imaging modality that provides in-depth view and 3D imaging can improve outcome following both conventional and innovative anastomosis techniques. Optical coherence tomography (OCT) is a noninvasive high-resolution (micron level), high-speed, 3D imaging modality that has been adopted widely in biomedical and clinical applications. In this work we performed a proof-of-concept evaluation study of OCT as an assisted intraoperative and post-operative imaging modality for microvascular anastomosis of rodent femoral vessels. The OCT imaging modality provided lateral resolution of 12 μm and 3.0 μm axial resolution in air and 0.27 volume/s imaging speed, which could provide the surgeon with clearly visualized vessel lumen wall and suture needle position relative to the vessel during intraoperative imaging. Graphics processing unit (GPU) accelerated phase-resolved Doppler OCT (PRDOCT) imaging of the surgical site was performed as a post-operative evaluation of the anastomosed vessels and to visualize the blood flow and thrombus formation. This information could help surgeons improve surgical precision in this highly challenging anastomosis of rodent vessels with diameter less than 0.5 mm. Our imaging modality could not only detect accidental suture through the back wall of lumen but also promptly diagnose and predict thrombosis immediately after reperfusion. Hence, real-time OCT can assist in decision-making process intra-operatively and avoid post-operative complications.

  18. TRAIL protein localization in human primary T cells by 3D microscopy using 3D interactive surface plot: a new method to visualize plasma membrane.

    PubMed

    Gras, Christophe; Smith, Nikaïa; Sengmanivong, Lucie; Gandini, Mariana; Kubelka, Claire Fernandes; Herbeuval, Jean-Philippe

    2013-01-31

    The apoptotic ligand TNF-related apoptosis ligand (TRAIL) is expressed on the membrane of immune cells during HIV infection. The intracellular stockade of TRAIL in human primary CD4(+) T cells is not known. Here we investigated whether primary CD4(+) T cells expressed TRAIL in their intracellular compartment and whether TRAIL is relocalized on the plasma membrane under HIV activation. We found that TRAIL protein was stocked in intracellular compartment in non activated CD4(+) T cells and that the total level of TRAIL protein was not increased under HIV-1 stimulation. However, TRAIL was massively relocalized on plasma membrane when cells were cultured with HIV. Using three dimensional (3D) microscopy we localized TRAIL protein in human T cells and developed a new method to visualize plasma membrane without the need of a membrane marker. This method used the 3D interactive surface plot and bright light acquired images. PMID:23085529

  19. TRAIL protein localization in human primary T cells by 3D microscopy using 3D interactive surface plot: a new method to visualize plasma membrane.

    PubMed

    Gras, Christophe; Smith, Nikaïa; Sengmanivong, Lucie; Gandini, Mariana; Kubelka, Claire Fernandes; Herbeuval, Jean-Philippe

    2013-01-31

    The apoptotic ligand TNF-related apoptosis ligand (TRAIL) is expressed on the membrane of immune cells during HIV infection. The intracellular stockade of TRAIL in human primary CD4(+) T cells is not known. Here we investigated whether primary CD4(+) T cells expressed TRAIL in their intracellular compartment and whether TRAIL is relocalized on the plasma membrane under HIV activation. We found that TRAIL protein was stocked in intracellular compartment in non activated CD4(+) T cells and that the total level of TRAIL protein was not increased under HIV-1 stimulation. However, TRAIL was massively relocalized on plasma membrane when cells were cultured with HIV. Using three dimensional (3D) microscopy we localized TRAIL protein in human T cells and developed a new method to visualize plasma membrane without the need of a membrane marker. This method used the 3D interactive surface plot and bright light acquired images.

  20. Nonlinear Optical Macroscopic Assessment of 3-D Corneal Collagen Organization and Axial Biomechanics

    PubMed Central

    Winkler, Moritz; Chai, Dongyul; Kriling, Shelsea; Nien, Chyong Jy; Brown, Donald J.; Jester, Bryan; Juhasz, Tibor

    2011-01-01

    Purpose. To characterize and quantify the collagen fiber (lamellar) organization of human corneas in three dimensions by using nonlinear optical high-resolution macroscopy (NLO-HRMac) and to correlate these findings with mechanical data obtained by indentation testing of corneal flaps. Methods. Twelve corneas from 10 donors were studied. Vibratome sections, 200 μm thick, from five donor eyes were cut along the vertical meridian from limbus to limbus (arc length, 12 mm). Backscattered second harmonic–generated (SHG) NLO signals from these sections were collected as a series of overlapping 3-D images, which were concatenated to form a single 3-D mosaic (pixel resolution: 0.44 μm lateral, 2 μm axial). Collagen fiber intertwining was quantified by determining branching point density as a function of stromal depth. Mechanical testing was performed on corneal flaps from seven additional eyes. Corneas were cut into three layers (anterior, middle, and posterior) using a femtosecond surgical laser system and underwent indentation testing to determine the elastic modulus for each layer. Results. The 3-D reconstructions revealed complex collagen fiber branching patterns in the anterior cornea, with fibers extending from the anterior limiting lamina (ALL, Bowman's layer), intertwining with deeper fibers and reinserting back to the ALL, forming bow spring–like structures. Measured branching-point density was four times higher in the anterior third of the cornea than in the posterior third and decreased logarithmically with increasing distance from the ALL. Indentation testing showed an eightfold increase in elastic modulus in the anterior stroma. Conclusions. The axial gradient in lamellar intertwining appears to be associated with an axial gradient in the effective elastic modulus of the cornea, suggesting that collagen fiber intertwining and formation of bow spring–like structures provide structural support similar to cross-beams in bridges and large-scale structures

  1. Additive manufactured polymeric 3D scaffolds with tailored surface topography influence mesenchymal stromal cells activity.

    PubMed

    Neves, Sara C; Mota, Carlos; Longoni, Alessia; Barrias, Cristina C; Granja, Pedro L; Moroni, Lorenzo

    2016-06-01

    Additive manufactured three-dimensional (3D) scaffolds with tailored surface topography constitute a clear advantage in tissue regeneration strategies to steer cell behavior. 3D fibrous scaffolds of poly(ethylene oxide terephthalate)/poly(butylene terephthalate) block copolymer presenting different fiber surface features were successfully fabricated by additive manufacturing combined with wet-spinning, in a single step, without any post-processing. The optimization of the processing parameters, mainly driven by different solvent/non-solvent combinations, led to four distinct scaffold types, with average surface roughness values ranging from 0.071 ± 0.012 μm to 1.950 ± 0.553 μm, average pore sizes in the x- and y-axis between 351.1 ± 33.6 μm and 396.1 ± 32.3 μm, in the z-axis between 36.5 ± 5.3 μm and 70.7 ± 8.8 μm, average fiber diameters between 69.4 ± 6.1 μm and 99.0 ± 9.4 μm, and porosity values ranging from 60.2 ± 0.8% to 71.7 ± 2.6%. Human mesenchymal stromal cells (hMSCs) cultured on these scaffolds adhered, proliferated, and produced endogenous extracellular matrix. The effect of surface roughness and topography on hMSCs differentiation was more evident for cells seeded at lower density, where the percentage of cells in direct contact with the surface was higher compared to more densely seeded scaffolds. Under osteogenic conditions, lower surface roughness values (0.227 ± 0.035 μm) had a synergistic effect on hMSCs behavior, while chondrogenesis was favored on rougher surfaces (1.950 ± 0.553 μm). PMID:27219645

  2. Performance analysis of different surface reconstruction algorithms for 3D reconstruction of outdoor objects from their digital images.

    PubMed

    Maiti, Abhik; Chakravarty, Debashish

    2016-01-01

    3D reconstruction of geo-objects from their digital images is a time-efficient and convenient way of studying the structural features of the object being modelled. This paper presents a 3D reconstruction methodology which can be used to generate photo-realistic 3D watertight surface of different irregular shaped objects, from digital image sequences of the objects. The 3D reconstruction approach described here is robust, simplistic and can be readily used in reconstructing watertight 3D surface of any object from its digital image sequence. Here, digital images of different objects are used to build sparse, followed by dense 3D point clouds of the objects. These image-obtained point clouds are then used for generation of photo-realistic 3D surfaces, using different surface reconstruction algorithms such as Poisson reconstruction and Ball-pivoting algorithm. Different control parameters of these algorithms are identified, which affect the quality and computation time of the reconstructed 3D surface. The effects of these control parameters in generation of 3D surface from point clouds of different density are studied. It is shown that the reconstructed surface quality of Poisson reconstruction depends on Samples per node (SN) significantly, greater SN values resulting in better quality surfaces. Also, the quality of the 3D surface generated using Ball-Pivoting algorithm is found to be highly depend upon Clustering radius and Angle threshold values. The results obtained from this study give the readers of the article a valuable insight into the effects of different control parameters on determining the reconstructed surface quality. PMID:27386376

  3. Performance analysis of different surface reconstruction algorithms for 3D reconstruction of outdoor objects from their digital images.

    PubMed

    Maiti, Abhik; Chakravarty, Debashish

    2016-01-01

    3D reconstruction of geo-objects from their digital images is a time-efficient and convenient way of studying the structural features of the object being modelled. This paper presents a 3D reconstruction methodology which can be used to generate photo-realistic 3D watertight surface of different irregular shaped objects, from digital image sequences of the objects. The 3D reconstruction approach described here is robust, simplistic and can be readily used in reconstructing watertight 3D surface of any object from its digital image sequence. Here, digital images of different objects are used to build sparse, followed by dense 3D point clouds of the objects. These image-obtained point clouds are then used for generation of photo-realistic 3D surfaces, using different surface reconstruction algorithms such as Poisson reconstruction and Ball-pivoting algorithm. Different control parameters of these algorithms are identified, which affect the quality and computation time of the reconstructed 3D surface. The effects of these control parameters in generation of 3D surface from point clouds of different density are studied. It is shown that the reconstructed surface quality of Poisson reconstruction depends on Samples per node (SN) significantly, greater SN values resulting in better quality surfaces. Also, the quality of the 3D surface generated using Ball-Pivoting algorithm is found to be highly depend upon Clustering radius and Angle threshold values. The results obtained from this study give the readers of the article a valuable insight into the effects of different control parameters on determining the reconstructed surface quality.

  4. 3D surface reconstruction and FIB microscopy of worn alumina hip prostheses

    NASA Astrophysics Data System (ADS)

    Zeng, P.; Inkson, B. J.; Rainforth, W. M.; Stewart, T.

    2008-08-01

    Interest in alumina-on-alumina total hip replacements (THR) continues to grow for the young and active patient due to their superior wear performance and biocompatibility compared to the alternative traditional polymer/metal prostheses. While alumina on alumina bearings offer an excellent solution, a region of high wear, known as stripe wear, is commonly observed on retrieved alumina hip components that poses concern. These in-vivo stripe wear mechanisms can be replicated in vitro by the introduction of micro-separation during the simulated walking cycle in hip joint simulation. However, the understanding of the mechanisms behind the stripe wear processes is relatively poor. 3D topographic reconstructions of titled SEM stereo pairs from different zones have been obtained to determine the local worn surface topography. Focused ion beam (FIB) microscopy was applied to examine the subsurface damage across the stripe wear. The paper presents novel images of sub-surface microcracks in alumina along with 3D reconstructions of the worn ceramic surfaces and a classification of four distinct wear zones following microseparation in hip prostheses.

  5. A 3-D enlarged cell technique (ECT) for elastic wave modelling of a curved free surface

    NASA Astrophysics Data System (ADS)

    Wei, Songlin; Zhou, Jianyang; Zhuang, Mingwei; Liu, Qing Huo

    2016-09-01

    The conventional finite-difference time-domain (FDTD) method for elastic waves suffers from the staircasing error when applied to model a curved free surface because of its structured grid. In this work, an improved, stable and accurate 3-D FDTD method for elastic wave modelling on a curved free surface is developed based on the finite volume method and enlarged cell technique (ECT). To achieve a sufficiently accurate implementation, a finite volume scheme is applied to the curved free surface to remove the staircasing error; in the mean time, to achieve the same stability as the FDTD method without reducing the time step increment, the ECT is introduced to preserve the solution stability by enlarging small irregular cells into adjacent cells under the condition of conservation of force. This method is verified by several 3-D numerical examples. Results show that the method is stable at the Courant stability limit for a regular FDTD grid, and has much higher accuracy than the conventional FDTD method.

  6. A 3-D enlarged cell technique (ECT) for elastic wave modelling of a curved free surface

    NASA Astrophysics Data System (ADS)

    Wei, Songlin; Zhou, Jianyang; Zhuang, Mingwei; Liu, Qing Huo

    2016-07-01

    The conventional finite-difference time-domain (FDTD) method for elastic waves suffers from the staircasing error when applied to model a curved free surface because of its structured grid. In this work, an improved, stable and accurate 3-D FDTD method for elastic wave modelling on a curved free surface is developed based on the finite volume method and enlarged cell technique (ECT). To achieve a sufficiently accurate implementation, a finite volume scheme is applied to the curved free surface to remove the staircasing error; in the mean time, to achieve the same stability as the FDTD method without reducing the time step increment, the ECT is introduced to preserve the solution stability by enlarging small irregular cells into adjacent cells under the condition of conservation of force. This method is verified by several 3-D numerical examples. Results show that the method is stable at the Courant stability limit for a regular FDTD grid, and has much higher accuracy than the conventional FDTD method.

  7. 3D Surface Profile and Color Stability of Tooth Colored Filling Materials after Bleaching.

    PubMed

    Irawan, Bryant Anthony; Irawan, Stacey Natalie; Masudi, Sam'an Malik; Sukminingrum, Ninin; Alam, Mohammad Khursheed

    2015-01-01

    This study aims to evaluate the effects of vital tooth bleaching with carbamide peroxide home bleaching and in-office bleaching on the color stability and 3D surface profile of dental restorative filling materials. Thirty discs (n = 30) measure 6 mm in diameter and 2 mm thick for each of three restorative materials. These are nanofilled composite Filtek Z350 XT, the submicron composite Estelite Σ Quick, and nanofilled glass ionomer Ketac N100 nanoionomer and were fabricated in shade A2. Each group was further divided into three subgroups (n = 10): subgroup A (Opalescence PF), subgroup B (Opalescence Boost in-office bleaching), and subgroup C (distilled water) serving as control. Samples were bleached according to the manufacturer's instructions for a period of two weeks. The Commission Internationale de L'Eclairage (CIE L(*), a(*), b(*)) system was chosen for image processing, while 3D surface profile was tested with atomic force microscopy (AFM). Statistical analyses were performed with the Mann-Whitney tests and Krusal-Wallis with a P value of ≤ 0.05. The three restorative materials showed significant color changes (ΔE); P ≤ 0.05. In diminishing order, the mean color changes recorded were Estelite Σ (3.82 ± 1.6) > Ketac Nano (2.97 ± 1.2) > Filtek Z350 XT (2.25 ± 1.0). However, none of the tested materials showed statistically significant changes in surface roughness; P > 0.05. PMID:26558267

  8. Mapping gray-scale image to 3D surface scanning data by ray tracing

    NASA Astrophysics Data System (ADS)

    Li, Peng; Jones, Peter R. M.

    1997-03-01

    The extraction and location of feature points from range imaging is an important but difficult task in machine vision based measurement systems. There exist some feature points which are not able to be detected from pure geometric characteristics, particularly in those measurement tasks related to the human body. The Loughborough Anthropometric Shadow Scanner (LASS) is a whole body surface scanner based on structured light technique. Certain applications of LASS require accurate location of anthropometric landmarks from the scanned data. This is sometimes impossible from existing raw data because some landmarks do not appear in the scanned data. Identification of these landmarks has to resort to surface texture of the scanned object. Modifications to LASS were made to allow gray-scale images to be captured before or after the object was scanned. Two-dimensional gray-scale image must be mapped to the scanned data to acquire the 3D coordinates of a landmark. The method to map 2D images to the scanned data is based on the colinearity conditions and ray-tracing method. If the camera center and image coordinates are known, the corresponding object point must lie on a ray starting from the camera center and connecting to the image coordinate. By intersecting the ray with the scanned surface of the object, the 3D coordinates of a point can be solved. Experimentation has demonstrated the feasibility of the method.

  9. 3D Cloud Radiative Effects on Aerosol Optical Thickness Retrievals in Cumulus Cloud Fields in the Biomass Burning Region in Brazil

    NASA Technical Reports Server (NTRS)

    Wen, Guo-Yong; Marshak, Alexander; Cahalan, Robert F.

    2004-01-01

    Aerosol amount in clear regions of a cloudy atmosphere is a critical parameter in studying the interaction between aerosols and clouds. Since the global cloud cover is about 50%, cloudy scenes are often encountered in any satellite images. Aerosols are more or less transparent, while clouds are extremely reflective in the visible spectrum of solar radiation. The radiative transfer in clear-cloudy condition is highly three- dimensional (3D). This paper focuses on estimating the 3D effects on aerosol optical thickness retrievals using Monte Carlo simulations. An ASTER image of cumulus cloud fields in the biomass burning region in Brazil is simulated in this study. The MODIS products (i-e., cloud optical thickness, particle effective radius, cloud top pressure, surface reflectance, etc.) are used to construct the cloud property and surface reflectance fields. To estimate the cloud 3-D effects, we assume a plane-parallel stratification of aerosol properties in the 60 km x 60 km ASTER image. The simulated solar radiation at the top of the atmosphere is compared with plane-parallel calculations. Furthermore, the 3D cloud radiative effects on aerosol optical thickness retrieval are estimated.

  10. Measuring surface topography with scanning electron microscopy. I. EZEImage: a program to obtain 3D surface data.

    PubMed

    Ponz, Ezequiel; Ladaga, Juan Luis; Bonetto, Rita Dominga

    2006-04-01

    Scanning electron microscopy (SEM) is widely used in the science of materials and different parameters were developed to characterize the surface roughness. In a previous work, we studied the surface topography with fractal dimension at low scale and two parameters at high scale by using the variogram, that is, variance vs. step log-log graph, of a SEM image. Those studies were carried out with the FERImage program, previously developed by us. To verify the previously accepted hypothesis by working with only an image, it is indispensable to have reliable three-dimensional (3D) surface data. In this work, a new program (EZEImage) to characterize 3D surface topography in SEM has been developed. It uses fast cross correlation and dynamic programming to obtain reliable dense height maps in a few seconds which can be displayed as an image where each gray level represents a height value. This image can be used for the FERImage program or any other software to obtain surface topography characteristics. EZEImage also generates anaglyph images as well as characterizes 3D surface topography by means of a parameter set to describe amplitude properties and three functional indices for characterizing bearing and fluid properties. PMID:17481354

  11. Preliminary study of surface modification of 3D Poly (ɛ - caprolactone) scaffolds by ultrashort laser irradiation

    NASA Astrophysics Data System (ADS)

    Daskalova, A.; Bliznakova, I.; Iordanova, E.; Yankov, G.; Grozeva, M.; Ostrowska, B.

    2016-02-01

    Three - dimensional poly (e- caprolactone) (PCL) scaffolds as suitable biocompatible material for manufacturing tissue replacements are utilized for tissue engineering purposes. The porous structures are fabricated by rapid prototyping method (Bioscaffolder) based on hypodermic dispensing process. The consecution of experiments demonstrated the possibility on creation of surface micro formations, applying different laser fluences, at 1 kHz repetition rate for fixed time of exposure 1 sec at 800 nm central wavelength. The combination of both methods offers possibilities for successful production of 3D matrices with modified surfaces. The obtained results of laser - induced surface modifications of PCL demonstrate the potential of the method to microprocess this kind of material for possible applications in regenerative medicine.

  12. An adaptive learning approach for 3-D surface reconstruction from point clouds.

    PubMed

    Junior, Agostinho de Medeiros Brito; Neto, Adrião Duarte Dória; de Melo, Jorge Dantas; Goncalves, Luiz Marcos Garcia

    2008-06-01

    In this paper, we propose a multiresolution approach for surface reconstruction from clouds of unorganized points representing an object surface in 3-D space. The proposed method uses a set of mesh operators and simple rules for selective mesh refinement, with a strategy based on Kohonen's self-organizing map (SOM). Basically, a self-adaptive scheme is used for iteratively moving vertices of an initial simple mesh in the direction of the set of points, ideally the object boundary. Successive refinement and motion of vertices are applied leading to a more detailed surface, in a multiresolution, iterative scheme. Reconstruction was experimented on with several point sets, including different shapes and sizes. Results show generated meshes very close to object final shapes. We include measures of performance and discuss robustness.

  13. Segmentation of the brain from 3D MRI using a hierarchical active surface template

    NASA Astrophysics Data System (ADS)

    Snell, John W.; Merickel, Michael B.; Ortega, James M.; Goble, John C.; Brookeman, James R.; Kassell, Neal F.

    1994-05-01

    The accurate segmentation of the brain from three-dimensional medical imagery is important as the basis for visualization, morphometry, surgical planning and intraoperative navigation. The complex and variable nature of brain anatomy makes recognition of the brain boundaries a difficult problem and frustrates segmentation schemes based solely on local image features. We have developed a deformable surface model of the brain as a mechanism for utilizing a priori anatomical knowledge in the segmentation process. The active surface template uses an energy minimization scheme to find a globally consistent surface configuration given a set of potentially ambiguous image features. Solution of the entire 3D problem at once produces superior results to those achieved using a slice by slice approach. We have achieved good results with MR image volumes of both normal and abnormal subjects. Evaluation of the segmentation results has been performed using cadaver studies.

  14. A prototype fan-beam optical CT scanner for 3D dosimetry

    SciTech Connect

    Campbell, Warren G.; Rudko, D. A.; Braam, Nicolas A.; Jirasek, Andrew; Wells, Derek M.

    2013-06-15

    Purpose: The objective of this work is to introduce a prototype fan-beam optical computed tomography scanner for three-dimensional (3D) radiation dosimetry. Methods: Two techniques of fan-beam creation were evaluated: a helium-neon laser (HeNe, {lambda} = 543 nm) with line-generating lens, and a laser diode module (LDM, {lambda} = 635 nm) with line-creating head module. Two physical collimator designs were assessed: a single-slot collimator and a multihole collimator. Optimal collimator depth was determined by observing the signal of a single photodiode with varying collimator depths. A method of extending the dynamic range of the system is presented. Two sample types were used for evaluations: nondosimetric absorbent solutions and irradiated polymer gel dosimeters, each housed in 1 liter cylindrical plastic flasks. Imaging protocol investigations were performed to address ring artefacts and image noise. Two image artefact removal techniques were performed in sinogram space. Collimator efficacy was evaluated by imaging highly opaque samples of scatter-based and absorption-based solutions. A noise-based flask registration technique was developed. Two protocols for gel manufacture were examined. Results: The LDM proved advantageous over the HeNe laser due to its reduced noise. Also, the LDM uses a wavelength more suitable for the PRESAGE{sup TM} dosimeter. Collimator depth of 1.5 cm was found to be an optimal balance between scatter rejection, signal strength, and manufacture ease. The multihole collimator is capable of maintaining accurate scatter-rejection to high levels of opacity with scatter-based solutions (T < 0.015%). Imaging protocol investigations support the need for preirradiation and postirradiation scanning to reduce reflection-based ring artefacts and to accommodate flask imperfections and gel inhomogeneities. Artefact removal techniques in sinogram space eliminate streaking artefacts and reduce ring artefacts of up to {approx}40% in magnitude. The

  15. Optical absorption in 3D topological insulator Bi2Te3 with applications to THz detectors (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Sengupta, Parijat; Bellotti, Enrico

    2015-08-01

    Topological insulators (TI) are a new class of materials that have an energy gap in bulk but possess gapless states bound to the sample surface or edge that have been theoretically predicted and experimentally observed [1]. The topological state in Bi2Te3 is characterized by a linear dispersion and a Dirac cone at the Γpoint. The optical absorption on the surface of a TI is given by the standard graphene-like απ/2 when a linear dispersion is assumed. Realistically, at k-points away from Γ, higher order cubic terms in k that represent the underlying hexagonal symmetry [2] of the crystal dominate and give rise to warping of bands. The optical absorption of a ferromagnetic coated gapped 3D TI film with warping terms considered is longer απ/2 but significantly modified. We demonstrate, by using wave functions from a continuum-Hamiltonian and Fermi-golden rule, the absorption spectrum on the surface of a TI as a function of the chemical potential, film-thickness and incident photon energy. A linear response theory based calculation is also performed using the Kubo formula to determine the longitudinal optical conductivity whose real part gives absorption as a function of photon frequency. The absorption in materials with Dirac fermions which is significantly higher than in normal THz detectors [3] can be further modulated in a TI by explicitly including the warping term making them highly efficient and tunable photodetectors. [1] M.Hasan and C.Kane, Rev.Mod.Phys. 82, 3045(2010) [2] L.Fu, Phys.Rev.Lett.103, 266801(2009) [3] X.Zhang et al., Phys. Rev B, 82, 245107(2010)

  16. Persistent and automatic intraoperative 3D digitization of surfaces under dynamic magnifications of an operating microscope

    PubMed Central

    Kumar, Ankur N.; Miga, Michael I.; Pheiffer, Thomas S.; Chambless, Lola B.; Thompson, Reid C.; Dawant, Benoit M.

    2014-01-01

    One of the major challenges impeding advancement in image-guided surgical (IGS) systems is the soft-tissue deformation during surgical procedures. These deformations reduce the utility of the patient’s preoperative images and may produce inaccuracies in the application of preoperative surgical plans. Solutions to compensate for the tissue deformations include the acquisition of intraoperative tomographic images of the whole organ for direct displacement measurement and techniques that combines intraoperative organ surface measurements with computational biomechanical models to predict subsurface displacements. The later solution has the advantage of being less expensive and amenable to surgical workflow. Several modalities such as textured laser scanners, conoscopic holography, and stereo-pair cameras have been proposed for the intraoperative 3D estimation of organ surfaces to drive patient-specific biomechanical models for the intraoperative update of preoperative images. Though each modality has its respective advantages and disadvantages, stereo-pair camera approaches used within a standard operating microscope is the focus of this article. A new method that permits the automatic and near real-time estimation of 3D surfaces (at 1Hz) under varying magnifications of the operating microscope is proposed. This method has been evaluated on a CAD phantom object and on full-length neurosurgery video sequences (~1 hour) acquired intraoperatively by the proposed stereovision system. To the best of our knowledge, this type of validation study on full-length brain tumor surgery videos has not been done before. The method for estimating the unknown magnification factor of the operating microscope achieves accuracy within 0.02 of the theoretical value on a CAD phantom and within 0.06 on 4 clinical videos of the entire brain tumor surgery. When compared to a laser range scanner, the proposed method for reconstructing 3D surfaces intraoperatively achieves root mean square

  17. ALE3D Simulations of Gap Closure and Surface Ignition for Cookoff Modeling

    SciTech Connect

    Howard, W M; McClelland, M A; Nichols, A L

    2006-06-22

    We are developing ALE3D models to describe the thermal, chemical and mechanical behavior during the heating, ignition and explosive phases of various cookoff phenomena. The candidate models and numerical strategies are being evaluated using benchmark cookoff experiments. ALE3D is a three-dimensional computer code capable of solving the model equations in a coupled fashion through all the phases of the cookoff in a single calculation. For the cookoff experiments, we are interested in representing behavior on widely varying timescales. We have used an implicit hydrodynamics option during the heating phase and an explicit solution method during the explosive phase. To complicate the modeling problem, high heat fluxes cause rapid temperature increases in boundary layers and lead to the formation of gaps between energetic and structural materials and ignition on surfaces. The initially solid energetic and structural materials react to produce gases, which fill the gaps. These materials can also melt and flow. Since an implicit solution method is used, simple no-strength materials models can no longer be used for liquids and gases. In this paper, we discuss and demonstrate choices of materials models for solid/liquid/gas mixtures to be used in conjunction with the implicit solution method. In addition, results are given for mesh movement strategies applied to the opening, closing, and surface ignition within gaps.

  18. Efficient 3D geometric and Zernike moments computation from unstructured surface meshes.

    PubMed

    Pozo, José María; Villa-Uriol, Maria-Cruz; Frangi, Alejandro F

    2011-03-01

    This paper introduces and evaluates a fast exact algorithm and a series of faster approximate algorithms for the computation of 3D geometric moments from an unstructured surface mesh of triangles. Being based on the object surface reduces the computational complexity of these algorithms with respect to volumetric grid-based algorithms. In contrast, it can only be applied for the computation of geometric moments of homogeneous objects. This advantage and restriction is shared with other proposed algorithms based on the object boundary. The proposed exact algorithm reduces the computational complexity for computing geometric moments up to order N with respect to previously proposed exact algorithms, from N(9) to N(6). The approximate series algorithm appears as a power series on the rate between triangle size and object size, which can be truncated at any desired degree. The higher the number and quality of the triangles, the better the approximation. This approximate algorithm reduces the computational complexity to N(3). In addition, the paper introduces a fast algorithm for the computation of 3D Zernike moments from the computed geometric moments, with a computational complexity N(4), while the previously proposed algorithm is of order N(6). The error introduced by the proposed approximate algorithms is evaluated in different shapes and the cost-benefit ratio in terms of error, and computational time is analyzed for different moment orders. PMID:20714011

  19. 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.

  20. 2D and 3D micro-XRF based on polycapillary optics at XLab Frascati

    NASA Astrophysics Data System (ADS)

    Polese, C.; Cappuccio, G.; Dabagov, S. B.; Hampai, D.; Liedl, A.; Pace, E.

    2015-08-01

    XRF imaging spectrometry is a powerful tool for materials characterization. A high spatial resolution is often required, in order to appreciate very tiny details of the studied object. With respect to simple pinholes, polycapillary optics allows much more intense fluxes to be achieved. This is fundamental to detect elements in trace and to strongly reduce the global acquisition time that is actually among the main reasons, in addition to radioprotection issues, affecting the competitiveness of XRF imaging with respect to other faster imaging techniques such as multispectral imaging. Unlike other well-known X-ray optics, principally employed for high brilliant radiation source such as synchrotron facilities, polyCO can be efficiently coupled also with conventional X-ray tubes. All these aspects make them the most suitable choice to realize portable, safe and high performing μXRF spectrometers. In this work preliminary results achieved with a novel 2D and 3D XRF facility, called Rainbow X-Ray (RXR), are reported, with particular attention to the spatial resolution achieved. RXR is based on the confocal arrangement of three polycapillary lenses, one focusing the primary beam and the other two capturing the fluorescence signal. The detection system is split in two couples of lens-detector in order to cover a wider energy range. The entire device is a laboratory user-friendly facility and, though it allows measurements on medium-size objects, its dimensions do not preclude it to be transported for in situ analysis on request, thanks also to a properly shielded cabinet.

  1. Best fit refractive index of matching liquid for 3D NIPAM gel dosimeters using optical CT

    NASA Astrophysics Data System (ADS)

    Chen, Chin-Hsing; Wu, Jay; Hsieh, Bor-Tsung; Chen, De-Shiou; Wang, Tzu-Hwei; Chien, Sou-Hsin; Chang, Yuan-Jen

    2014-11-01

    The accuracy of an optical computed tomography (CT)-based dosimeter is significantly affected by the refractive index (RI) of the matching liquid. Mismatched RI induces reflection and refraction as the laser beam passes through the gel phantom. Moreover, the unwanted light rays collected by the photodetector produce image artifacts after image reconstruction from the collected data. To obtain the best image quality, this study investigates the best-fit RI of the matching liquid for a 3D NIPAM gel dosimeter. The three recipes of NIPAM polymer gel used in this study consisted of 5% gelatin, 5% NIPAM and 3% N,N'-methylene bisacrylamide, which were combined with three compositions (5, 10, and 20 mM) of Tetrakis (hydroxymethyl) phosphonium chloride. Results were evaluated using a quantitative evaluation method of the gamma evaluation technique. Results showed that the best-fit RI for the non-irradiated NIPAM gel ranges from 1.340 to 1.346 for various NIPAM recipes with sensitivities ranging from 0.0113 to 0.0227. The greatest pass rate of 88.00% is achieved using best-fit RI=1.346 of the matching liquid. The adoption of mismatching RI decreases the gamma pass rate by 2.63% to 16.75% for all three recipes of NIPAM gel dosimeters. In addition, the maximum average deviation is less than 0.1% for the red and transparent matching liquids. Thus, the color of the matching liquid does not affect the measurement accuracy of the NIPAM gel dosimeter, as measured by optical CT.

  2. Spatially monitoring oxygen level in 3D microfabricated cell culture systems using optical oxygen sensing beads.

    PubMed

    Wang, Lin; Acosta, Miguel A; Leach, Jennie B; Carrier, Rebecca L

    2013-04-21

    Capability of measuring and monitoring local oxygen concentration at the single cell level (tens of microns scale) is often desirable but difficult to achieve in cell culture. In this study, biocompatible oxygen sensing beads were prepared and tested for their potential for real-time monitoring and mapping of local oxygen concentration in 3D micro-patterned cell culture systems. Each oxygen sensing bead is composed of a silica core loaded with both an oxygen sensitive Ru(Ph2phen3)Cl2 dye and oxygen insensitive Nile blue reference dye, and a poly-dimethylsiloxane (PDMS) shell rendering biocompatibility. Human intestinal epithelial Caco-2 cells were cultivated on a series of PDMS and type I collagen based substrates patterned with micro-well arrays for 3 or 7 days, and then brought into contact with oxygen sensing beads. Using an image analysis algorithm to convert florescence intensity of beads to partial oxygen pressure in the culture system, tens of microns-size oxygen sensing beads enabled the spatial measurement of local oxygen concentration in the microfabricated system. Results generally indicated lower oxygen level inside wells than on top of wells, and local oxygen level dependence on structural features of cell culture surfaces. Interestingly, chemical composition of cell culture substrates also appeared to affect oxygen level, with type-I collagen based cell culture systems having lower oxygen concentration compared to PDMS based cell culture systems. In general, results suggest that oxygen sensing beads can be utilized to achieve real-time and local monitoring of micro-environment oxygen level in 3D microfabricated cell culture systems.

  3. Real Time Gabor-Domain Optical Coherence Microscopy for 3D Imaging.

    PubMed

    Rolland, Jannick P; Canavesi, Cristina; Tankam, Patrice; Cogliati, Andrea; Lanis, Mara; Santhanam, Anand P

    2016-01-01

    Fast, robust, nondestructive 3D imaging is needed for the characterization of microscopic tissue structures across various clinical applications. A custom microelectromechanical system (MEMS)-based 2D scanner was developed to achieve, together with a multi-level GPU architecture, 55 kHz fast-axis A-scan acquisition in a Gabor-domain optical coherence microscopy (GD-OCM) custom instrument. GD-OCM yields high-definition micrometer-class volumetric images. A dynamic depth of focusing capability through a bio-inspired liquid lens-based microscope design, as in whales' eyes, was developed to enable the high definition instrument throughout a large field of view of 1 mm3 volume of imaging. Developing this technology is prime to enable integration within the workflow of clinical environments. Imaging at an invariant resolution of 2 μm has been achieved throughout a volume of 1 × 1 × 0.6 mm3, acquired in less than 2 minutes. Volumetric scans of human skin in vivo and an excised human cornea are presented. PMID:27046601

  4. Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components.

    PubMed

    Malkov, Serghei; Shepherd, John

    2014-02-17

    We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed.

  5. Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components

    PubMed Central

    Malkov, Serghei; Shepherd, John

    2014-01-01

    We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed. PMID:25083118

  6. Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components

    NASA Astrophysics Data System (ADS)

    Malkov, Serghei; Shepherd, John

    2014-02-01

    We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed.

  7. Large area 3-D optical coherence tomography imaging of lumpectomy specimens for radiation treatment planning

    NASA Astrophysics Data System (ADS)

    Wang, Cuihuan; Kim, Leonard; Barnard, Nicola; Khan, Atif; Pierce, Mark C.

    2016-02-01

    Our long term goal is to develop a high-resolution imaging method for comprehensive assessment of tissue removed during lumpectomy procedures. By identifying regions of high-grade disease within the excised specimen, we aim to develop patient-specific post-operative radiation treatment regimens. We have assembled a benchtop spectral-domain optical coherence tomography (SD-OCT) system with 1320 nm center wavelength. Automated beam scanning enables "sub-volumes" spanning 5 mm x 5 mm x 2 mm (500 A-lines x 500 B-scans x 2 mm in depth) to be collected in under 15 seconds. A motorized sample positioning stage enables multiple sub-volumes to be acquired across an entire tissue specimen. Sub-volumes are rendered from individual B-scans in 3D Slicer software and en face (XY) images are extracted at specific depths. These images are then tiled together using MosaicJ software to produce a large area en face view (up to 40 mm x 25 mm). After OCT imaging, specimens were sectioned and stained with HE, allowing comparison between OCT image features and disease markers on histopathology. This manuscript describes the technical aspects of image acquisition and reconstruction, and reports initial qualitative comparison between large area en face OCT images and HE stained tissue sections. Future goals include developing image reconstruction algorithms for mapping an entire sample, and registering OCT image volumes with clinical CT and MRI images for post-operative treatment planning.

  8. GlaRe, a GIS tool to reconstruct the 3D surface of palaeoglaciers

    NASA Astrophysics Data System (ADS)

    Pellitero, Ramón; Rea, Brice R.; Spagnolo, Matteo; Bakke, Jostein; Ivy-Ochs, Susan; Frew, Craig R.; Hughes, Philip; Ribolini, Adriano; Lukas, Sven; Renssen, Hans

    2016-09-01

    Glacier reconstructions are widely used in palaeoclimatic studies and this paper presents a new semi-automated method for generating glacier reconstructions: GlaRe, is a toolbox coded in Python and operating in ArcGIS. This toolbox provides tools to generate the ice thickness from the bed topography along a palaeoglacier flowline applying the standard flow law for ice, and generates the 3D surface of the palaeoglacier using multiple interpolation methods. The toolbox performance has been evaluated using two extant glaciers, an icefield and a cirque/valley glacier from which the subglacial topography is known, using the basic reconstruction routine in GlaRe. Results in terms of ice surface, ice extent and equilibrium line altitude show excellent agreement that confirms the robustness of this procedure in the reconstruction of palaeoglaciers from glacial landforms such as frontal moraines.

  9. Effects of 3D Toroidally Asymmetric Magnetic Field on Tokamak Magnetic Surfaces

    NASA Astrophysics Data System (ADS)

    Lao, L. L.

    2005-10-01

    The effects of 3D error magnetic field on magnetic surfaces are investigated using the DIII-D internal coils (I-Coils). Slowly rotating n=1 traveling waves at 5 Hz and various amplitudes were applied to systematically perturb the edge surfaces by programming the I-Coil currents. The vertical separatrix location difference between EFIT magnetic reconstructions that assumes toroidal symmetry and Thomson scattering Te measurements responds in phase to the applied perturbed field. The oscillation amplitudes increase with the strength of the applied field but are much smaller than those expected from the applied field alone. The results indicate that plasma response is important. Various plasma response models based on results from the MHD codes MARS and GATO are being developed and compared to the experimental observations. To more accurately evaluate the effects of magnetic measurement errors, a new form of the magnetic uncertainty matrix is also being implemented into EFIT. Details will be presented.

  10. 3D Ag/ZnO hybrids for sensitive surface-enhanced Raman scattering detection

    NASA Astrophysics Data System (ADS)

    Huang, Chenyue; Xu, Chunxiang; Lu, Junfeng; Li, Zhaohui; Tian, Zhengshan

    2016-03-01

    To combine the surface plasma resonance of metal and local field enhancement in metal/semiconductor interface, Ag nanoparticles (NPs) were assembled on a ZnO nanorod array which was grown by hydrothermally on carbon fibers. The construction of dimensional (3D) Surface-Enhanced Raman Scattering (SERS) substrate is used for the sensitive detection of organic pollutants with the advantages such as facile synthesis, short detection time and low cost. The hybrid substrate was manifested a high sensitivity to phenol red at a lower concentration of 1 × 10-9 M and a higher enhancement factor of 3.18 × 109. Moreover, the ZnO nanostructures decorated with Ag NPs were demonstrated self-cleaning function under UV irradiation via photocatalytic degradation of the analytic molecules. The fabrication process of the materials and sensors, optimization of the SERS behaviors for different sized Ag NPs, the mechanism of SERS and recovery were presented with a detailed discussion.

  11. Uncertainty studies of topographical measurements on steel surface corrosion by 3D scanning electron microscopy.

    PubMed

    Kang, K W; Pereda, M D; Canafoglia, M E; Bilmes, P; Llorente, C; Bonetto, R

    2012-02-01

    Pitting corrosion is a damage mechanism quite serious and dangerous in both carbon steel boiler tubes for power plants which are vital to most industries and stainless steels for orthopedic human implants whose demand, due to the increase of life expectation and rate of traffic accidents, has sharply increased. Reliable methods to characterize this kind of damage are becoming increasingly necessary, when trying to evaluate the advance of damage and to establish the best procedures for component inspection in order to determine remaining lives and failure mitigation. A study about the uncertainties on the topographies of corrosion pits from 3D SEM images, obtained at low magnifications (where errors are greater) and different stage tilt angles were carried out using an in-house software previously developed. Additionally, measurements of pit depths on biomaterial surfaces, subjected to two different surface treatments on stainless steels, were carried out. The different depth distributions observed were in agreement with electrochemical measurements.

  12. Construction of Extended 3D Field of Views of the Internal Bladder Wall Surface: A Proof of Concept

    NASA Astrophysics Data System (ADS)

    Ben-Hamadou, Achraf; Daul, Christian; Soussen, Charles

    2016-09-01

    3D extended field of views (FOVs) of the internal bladder wall facilitate lesion diagnosis, patient follow-up and treatment traceability. In this paper, we propose a 3D image mosaicing algorithm guided by 2D cystoscopic video-image registration for obtaining textured FOV mosaics. In this feasibility study, the registration makes use of data from a 3D cystoscope prototype providing, in addition to each small FOV image, some 3D points located on the surface. This proof of concept shows that textured surfaces can be constructed with minimally modified cystoscopes. The potential of the method is demonstrated on numerical and real phantoms reproducing various surface shapes. Pig and human bladder textures are superimposed on phantoms with known shape and dimensions. These data allow for quantitative assessment of the 3D mosaicing algorithm based on the registration of images simulating bladder textures.

  13. Region-Based 3d Surface Reconstruction Using Images Acquired by Low-Cost Unmanned Aerial Systems

    NASA Astrophysics Data System (ADS)

    Lari, Z.; Al-Rawabdeh, A.; He, F.; Habib, A.; El-Sheimy, N.

    2015-08-01

    Accurate 3D surface reconstruction of our environment has become essential for an unlimited number of emerging applications. In the past few years, Unmanned Aerial Systems (UAS) are evolving as low-cost and flexible platforms for geospatial data collection that could meet the needs of aforementioned application and overcome limitations of traditional airborne and terrestrial mobile mapping systems. Due to their payload restrictions, these systems usually include consumer-grade imaging and positioning sensor which will negatively impact the quality of the collected geospatial data and reconstructed surfaces. Therefore, new surface reconstruction surfaces are needed to mitigate the impact of using low-cost sensors on the final products. To date, different approaches have been proposed to for 3D surface construction using overlapping images collected by imaging sensor mounted on moving platforms. In these approaches, 3D surfaces are mainly reconstructed based on dense matching techniques. However, generated 3D point clouds might not accurately represent the scanned surfaces due to point density variations and edge preservation problems. In order to resolve these problems, a new region-based 3D surface renostruction trchnique is introduced in this paper. This approach aims to generate a 3D photo-realistic model of individually scanned surfaces within the captured images. This approach is initiated by a Semi-Global dense Matching procedure is carried out to generate a 3D point cloud from the scanned area within the collected images. The generated point cloud is then segmented to extract individual planar surfaces. Finally, a novel region-based texturing technique is implemented for photorealistic reconstruction of the extracted planar surfaces. Experimental results using images collected by a camera mounted on a low-cost UAS demonstrate the feasibility of the proposed approach for photorealistic 3D surface reconstruction.

  14. Surface 3D nanostructuring by tightly focused laser pulse: simulations by Lagrangian code and molecular dynamics

    NASA Astrophysics Data System (ADS)

    Inogamov, Nail A.; Zhakhovsky, Vasily V.

    2016-02-01

    There are many important applications in which the ultrashort diffraction-limited and therefore tightly focused laser pulses irradiates metal films mounted on dielectric substrate. Here we present the detailed picture of laser peeling and 3D structure formation of the thin (relative to a depth of a heat affected zone in the bulk targets) gold films on glass substrate. The underlying physics of such diffraction-limited laser peeling was not well understood previously. Our approach is based on a physical model which takes into consideration the new calculations of the two-temperature (2T) equation of state (2T EoS) and the two-temperature transport coefficients together with the coupling parameter between electron and ion subsystems. The usage of the 2T EoS and the kinetic coefficients is required because absorption of an ultrashort pulse with duration of 10-1000 fs excites electron subsystem of metal and transfers substance into the 2T state with hot electrons (typical electron temperatures 1-3 eV) and much colder ions. It is shown that formation of submicrometer-sized 3D structures is a result of the electron-ion energy transfer, melting, and delamination of film from substrate under combined action of electron and ion pressures, capillary deceleration of the delaminated liquid metal or semiconductor, and ultrafast freezing of molten material. We found that the freezing is going in non-equilibrium regime with strongly overcooled liquid phase. In this case the Stefan approximation is non-applicable because the solidification front speed is limited by the diffusion rate of atoms in the molten material. To solve the problem we have developed the 2T Lagrangian code including all this reach physics in. We also used the high-performance combined Monte- Carlo and molecular dynamics code for simulation of surface 3D nanostructuring at later times after completion of electron-ion relaxation.

  15. Feasibility study on 3-D shape analysis of high-aspect-ratio features using through-focus scanning optical microscopy

    PubMed Central

    Attota, Ravi Kiran; Weck, Peter; Kramar, John A.; Bunday, Benjamin; Vartanian, Victor

    2016-01-01

    In-line metrologies currently used in the semiconductor industry are being challenged by the aggressive pace of device scaling and the adoption of novel device architectures. Metrology and process control of three-dimensional (3-D) high-aspect-ratio (HAR) features are becoming increasingly important and also challenging. In this paper we present a feasibility study of through-focus scanning optical microscopy (TSOM) for 3-D shape analysis of HAR features. TSOM makes use of 3-D optical data collected using a conventional optical microscope for 3-D shape analysis. Simulation results of trenches and holes down to the 11 nm node are presented. The ability of TSOM to analyze an array of HAR features or a single isolated HAR feature is also presented. This allows for the use of targets with area over 100 times smaller than that of conventional gratings, saving valuable real estate on the wafers. Indications are that the sensitivity of TSOM may match or exceed the International Technology Roadmap for Semiconductors (ITRS) measurement requirements for the next several years. Both simulations and preliminary experimental results are presented. The simplicity, lowcost, high throughput, and nanometer scale 3-D shape sensitivity of TSOM make it an attractive inspection and process monitoring solution for nanomanufacturing. PMID:27464112

  16. Feasibility study on 3-D shape analysis of high-aspect-ratio features using through-focus scanning optical microscopy.

    PubMed

    Attota, Ravi Kiran; Weck, Peter; Kramar, John A; Bunday, Benjamin; Vartanian, Victor

    2016-07-25

    In-line metrologies currently used in the semiconductor industry are being challenged by the aggressive pace of device scaling and the adoption of novel device architectures. Metrology and process control of three-dimensional (3-D) high-aspect-ratio (HAR) features are becoming increasingly important and also challenging. In this paper we present a feasibility study of through-focus scanning optical microscopy (TSOM) for 3-D shape analysis of HAR features. TSOM makes use of 3-D optical data collected using a conventional optical microscope for 3-D shape analysis. Simulation results of trenches and holes down to the 11 nm node are presented. The ability of TSOM to analyze an array of HAR features or a single isolated HAR feature is also presented. This allows for the use of targets with area over 100 times smaller than that of conventional gratings, saving valuable real estate on the wafers. Indications are that the sensitivity of TSOM may match or exceed the International Technology Roadmap for Semiconductors (ITRS) measurement requirements for the next several years. Both simulations and preliminary experimental results are presented. The simplicity, lowcost, high throughput, and nanometer scale 3-D shape sensitivity of TSOM make it an attractive inspection and process monitoring solution for nanomanufacturing. PMID:27464112

  17. COMPUTER SIMULATIONS OF SPRAY RETENTION BY A 3D BARLEY PLANT: EFFECT OF FORMULATION SURFACE TENSION.

    PubMed

    Massinon, M; De Cock, N; Salah, S Ouled Taleb; Lebeau, F

    2015-01-01

    A spray retention model was used in this study to explore theoretically the effect of a range of mixture surface tension on the spray retention and the variability of deposits. The spray retention model was based on an algorithm that tested whether droplets from a virtual nozzle intercepted a 3D plant model. If so, the algorithm determined the contribution of the droplet to the overall retention depending on the droplet impact behaviour on the leaf; adhesion, rebound or splashing. The impact outcome probabilities, function of droplet impact energy, were measured using high-speed imaging on an excised indoor grown barley leaf (BBCH12) both for pure water (surface tension of 0.072 N/m) and a non-ionic super spreader (static surface tension of 0.021 N/m) depending on the surface orientation. The modification of spray mixture properties in the simulations was performed by gradually changing the spray the droplet impact probabilities between pure water and a solution with non-ionic surfactant exhibiting super spreading properties. The plant architecture was measured using a structured light scanner. The final retention was expressed as the volume of liquid retained by the whole plant relative to the projected leaf surface area in the main spray direction. One hundred simulations were performed at different volumes per hectare and flat-fan nozzles for each formulation surface tension. The coefficient of variation was used as indicator of variability of deposits. The model was able to discriminate between mixture surface tension. The spray retention increased as the mixture surface tension decreased. The variability of deposits also decreased as the surface tension decreased. The proposed modelling approach provides a suited tool for sensitivity analysis: nozzle kind, pressure, volume per hectare applied, spray mixture physicochemical properties, plant species, growth stage could be screened to determine the best spraying characteristics maximizing the retention. The

  18. 3D Imaging of Water-Drop Condensation on Hydrophobic and Hydrophilic Lubricant-Impregnated Surfaces.

    PubMed

    Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

    2016-01-01

    Condensation of water from the atmosphere on a solid surface is an ubiquitous phenomenon in nature and has diverse technological applications, e.g. in heat and mass transfer. We investigated the condensation kinetics of water drops on a lubricant-impregnated surface, i.e., a micropillar array impregnated with a non-volatile ionic liquid. Growing and coalescing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. Different stages of condensation can be discriminated. On a lubricant-impregnated hydrophobic micropillar array these are: (1) Nucleation on the lubricant surface. (2) Regular alignment of water drops between micropillars and formation of a three-phase contact line on a bottom of the substrate. (3) Deformation and bridging by coalescence which eventually leads to a detachment of the drops from the bottom substrate. The drop-substrate contact does not result in breakdown of the slippery behaviour. Contrary, on a lubricant-impregnated hydrophilic micropillar array, the condensed water drops replace the lubricant. Consequently, the surface loses its slippery property. Our results demonstrate that a Wenzel-like to Cassie transition, required to maintain the facile removal of condensed water drops, can be induced by well-chosen surface hydrophobicity. PMID:27040483

  19. Multi-sensor system for surface inspection and 3D-geometry assessment

    NASA Astrophysics Data System (ADS)

    Becker, Markus; Weber, Juergen; Schubert, Erhard

    1997-09-01

    This paper addresses an installed application in quality control where a 100% inspection of geometry (3D) and surface of cuboid (parallelpiped) and ring-shaped magnets is done using a system of 2 CCD matrix cameras, one of which is equipped with on-board processing components and a transmitted-light sensor with microcontroller based data processing for the measurement of the height of the objects. The geometry and surface properties are measured with a diffuse indirect IR-LED flash, mounted in a ring around the object and a telecentric lens to avoid perspective distortions due to different heights of the measured objects. The surface inspection looks for broken pieces, surface faults due to spalling/chipping and for cracks. The second CCD camera uses the same illumination and algorithm to inspect the surface of the other side of the objects after it has been turned around in a return conveyor belt. All components are triggered by separate light barriers and perform their tasks independently. The integration of the results of each measurement is done by an SPC which also controls the actors that handle the three different classes of objects (good, bad, rework). These actors are valves and the objects are separated by pressurized air. The main concern of this paper is the system aspect, how the measurement results are evaluated and combined to achieve a correct classification of the objects which are inspected by three independent sensors and arrive at unpredictable time intervals.

  20. 3D Imaging of Water-Drop Condensation on Hydrophobic and Hydrophilic Lubricant-Impregnated Surfaces

    PubMed Central

    Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

    2016-01-01

    Condensation of water from the atmosphere on a solid surface is an ubiquitous phenomenon in nature and has diverse technological applications, e.g. in heat and mass transfer. We investigated the condensation kinetics of water drops on a lubricant-impregnated surface, i.e., a micropillar array impregnated with a non-volatile ionic liquid. Growing and coalescing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. Different stages of condensation can be discriminated. On a lubricant-impregnated hydrophobic micropillar array these are: (1) Nucleation on the lubricant surface. (2) Regular alignment of water drops between micropillars and formation of a three-phase contact line on a bottom of the substrate. (3) Deformation and bridging by coalescence which eventually leads to a detachment of the drops from the bottom substrate. The drop-substrate contact does not result in breakdown of the slippery behaviour. Contrary, on a lubricant-impregnated hydrophilic micropillar array, the condensed water drops replace the lubricant. Consequently, the surface loses its slippery property. Our results demonstrate that a Wenzel-like to Cassie transition, required to maintain the facile removal of condensed water drops, can be induced by well-chosen surface hydrophobicity. PMID:27040483

  1. 3D Imaging of Water-Drop Condensation on Hydrophobic and Hydrophilic Lubricant-Impregnated Surfaces

    NASA Astrophysics Data System (ADS)

    Kajiya, Tadashi; Schellenberger, Frank; Papadopoulos, Periklis; Vollmer, Doris; Butt, Hans-Jürgen

    2016-04-01

    Condensation of water from the atmosphere on a solid surface is an ubiquitous phenomenon in nature and has diverse technological applications, e.g. in heat and mass transfer. We investigated the condensation kinetics of water drops on a lubricant-impregnated surface, i.e., a micropillar array impregnated with a non-volatile ionic liquid. Growing and coalescing drops were imaged in 3D using a laser scanning confocal microscope equipped with a temperature and humidity control. Different stages of condensation can be discriminated. On a lubricant-impregnated hydrophobic micropillar array these are: (1) Nucleation on the lubricant surface. (2) Regular alignment of water drops between micropillars and formation of a three-phase contact line on a bottom of the substrate. (3) Deformation and bridging by coalescence which eventually leads to a detachment of the drops from the bottom substrate. The drop-substrate contact does not result in breakdown of the slippery behaviour. Contrary, on a lubricant-impregnated hydrophilic micropillar array, the condensed water drops replace the lubricant. Consequently, the surface loses its slippery property. Our results demonstrate that a Wenzel-like to Cassie transition, required to maintain the facile removal of condensed water drops, can be induced by well-chosen surface hydrophobicity.

  2. Surface functionalization of 3D glass-ceramic porous scaffolds for enhanced mineralization in vitro

    NASA Astrophysics Data System (ADS)

    Ferraris, Sara; Vitale-Brovarone, Chiara; Bretcanu, Oana; Cassinelli, Clara; Vernè, Enrica

    2013-04-01

    Bone reconstruction after tissue loosening due to traumatic, pathological or surgical causes is in increasing demand. 3D scaffolds are a widely studied solution for supporting new bone growth. Bioactive glass-ceramic porous materials can offer a three-dimensional structure that is able to chemically bond to bone. The ability to surface modify these devices by grafting biologically active molecules represents a challenge, with the aim of stimulating physiological bone regeneration with both inorganic and organic signals. In this research work glass ceramic scaffolds with very high mechanical properties and moderate bioactivity have been functionalized with the enzyme alkaline phosphatase (ALP). The material surface was activated in order to expose hydroxyl groups. The activated surface was further grafted with ALP both via silanization and also via direct grafting to the surface active hydroxyl groups. Enzymatic activity of grafted samples were measured by means of UV-vis spectroscopy before and after ultrasonic washing in TRIS-HCl buffer solution. In vitro inorganic bioactivity was investigated by soaking the scaffolds after the different steps of functionalization in a simulated body fluid (SBF). SEM observations allowed the monitoring of the scaffold morphology and surface chemical composition after soaking in SBF. The presence of ALP enhanced the in vitro inorganic bioactivity of the tested material.

  3. 3D Surface Reconstruction of Rills in a Spanish Olive Grove

    NASA Astrophysics Data System (ADS)

    Brings, Christine; Gronz, Oliver; Seeger, Manuel; Wirtz, Stefan; Taguas, Encarnación; Ries, Johannes B.

    2016-04-01

    The low-cost, user-friendly photogrammetric Structure from Motion (SfM) technique is used for 3D surface reconstruction and difference calculation of an 18 meter long rill in South Spain (Andalusia, Puente Genil). The images were taken with a Canon HD video camera before and after a rill experiment in an olive grove. Recording with a video camera has compared to a photo camera a huge time advantage and the method also guarantees more than adequately overlapping sharp images. For each model, approximately 20 minutes of video were taken. As SfM needs single images, the sharpest image was automatically selected from 8 frame intervals. The sharpness was estimated using a derivative-based metric. Then, VisualSfM detects feature points in each image, searches matching feature points in all image pairs and recovers the camera and feature positions. Finally, by triangulation of camera positions and feature points the software reconstructs a point cloud of the rill surface. From the point cloud, 3D surface models (meshes) are created and via difference calculations of the pre and post model a visualization of the changes (erosion and accumulation areas) and quantification of erosion volumes are possible. The calculated volumes are presented in spatial units of the models and so real values must be converted via references. The results show that rills in olive groves have a high dynamic due to the lack of vegetation cover under the trees, so that the rill can incise until the bedrock. Another reason for the high activity is the intensive employment of machinery.

  4. 3D Surface Profile and Color Stability of Tooth Colored Filling Materials after Bleaching

    PubMed Central

    Irawan, Bryant Anthony; Irawan, Stacey Natalie; Masudi, Sam'an Malik; Sukminingrum, Ninin; Alam, Mohammad Khursheed

    2015-01-01

    This study aims to evaluate the effects of vital tooth bleaching with carbamide peroxide home bleaching and in-office bleaching on the color stability and 3D surface profile of dental restorative filling materials. Thirty discs (n = 30) measure 6 mm in diameter and 2 mm thick for each of three restorative materials. These are nanofilled composite Filtek Z350 XT, the submicron composite Estelite Σ Quick, and nanofilled glass ionomer Ketac N100 nanoionomer and were fabricated in shade A2. Each group was further divided into three subgroups (n = 10): subgroup A (Opalescence PF), subgroup B (Opalescence Boost in-office bleaching), and subgroup C (distilled water) serving as control. Samples were bleached according to the manufacturer's instructions for a period of two weeks. The Commission Internationale de L'Eclairage (CIE L*, a*, b*) system was chosen for image processing, while 3D surface profile was tested with atomic force microscopy (AFM). Statistical analyses were performed with the Mann-Whitney tests and Krusal-Wallis with a P value of ≤0.05. The three restorative materials showed significant color changes (ΔE); P ≤ 0.05. In diminishing order, the mean color changes recorded were Estelite Σ (3.82 ± 1.6) > Ketac Nano (2.97 ± 1.2) > Filtek Z350 XT (2.25 ± 1.0). However, none of the tested materials showed statistically significant changes in surface roughness; P > 0.05. PMID:26558267

  5. 3D face recognition using simulated annealing and the surface interpenetration measure.

    PubMed

    Queirolo, Chauã C; Silva, Luciano; Bellon, Olga R P; Segundo, Maurício Pamplona

    2010-02-01

    This paper presents a novel automatic framework to perform 3D face recognition. The proposed method uses a Simulated Annealing-based approach (SA) for range image registration with the Surface Interpenetration Measure (SIM), as similarity measure, in order to match two face images. The authentication score is obtained by combining the SIM values corresponding to the matching of four different face regions: circular and elliptical areas around the nose, forehead, and the entire face region. Then, a modified SA approach is proposed taking advantage of invariant face regions to better handle facial expressions. Comprehensive experiments were performed on the FRGC v2 database, the largest available database of 3D face images composed of 4,007 images with different facial expressions. The experiments simulated both verification and identification systems and the results compared to those reported by state-of-the-art works. By using all of the images in the database, a verification rate of 96.5 percent was achieved at a False Acceptance Rate (FAR) of 0.1 percent. In the identification scenario, a rank-one accuracy of 98.4 percent was achieved. To the best of our knowledge, this is the highest rank-one score ever achieved for the FRGC v2 database when compared to results published in the literature. PMID:20075453

  6. Automated surface micro-machining mask creation from a 3D model.

    SciTech Connect

    Schiek, Richard Louis; Schmidt, Rodney Cannon

    2004-06-01

    We have developed and implemented a method, which given a three-dimensional object can infer from topology the two-dimensional masks needed to produce that object with surface micromachining. The masks produced by this design tool can be generic, process independent masks, or if given process constraints, specific for a target process. This design tool calculates the two-dimensional mask set required to produce a given three-dimensional model by investigating the vertical topology to the model. The 3D model is first separated into bodies that are non-intersecting, made from different materials or only linked through a ground plane. Next, for each body unique vertical cross sections are located and arranged into a tree based on their topological relationship. A branch-wise search of the tree uncovers locations where deposition boundaries must lie and identifies candidate masks creating a generic mask set for the 3D model. Finally, in the last step specific process requirements are considered that may constrain the generic mask set. Constraints can include the thickness or number of deposition layers, specific ordering of masks as required by a process and type of material used in a given layer. Candidate masks are reconciled with the process constraints through a constrained optimization.

  7. 3D Simulation of Missing Pellet Surface Defects in Light Water Reactor Fuel Rods

    SciTech Connect

    B.W. Spencer; J.D. Hales; S.R. Novascone; R.L. Williamson

    2012-09-01

    The cladding on light water reactor (LWR) fuel rods provides a stable enclosure for fuel pellets and serves as a first barrier against fission product release. Consequently, it is important to design fuel to prevent cladding failure due to mechanical interactions with fuel pellets. Cladding stresses can be effectively limited by controlling power increase rates. However, it has been shown that local geometric irregularities caused by manufacturing defects known as missing pellet surfaces (MPS) in fuel pellets can lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. Nuclear fuel performance codes commonly use a 1.5D (axisymmetric, axially-stacked, one-dimensional radial) or 2D axisymmetric representation of the fuel rod. To study the effects of MPS defects, results from 1.5D or 2D fuel performance analyses are typically mapped to thermo-mechanical models that consist of a 2D plane-strain slice or a full 3D representation of the geometry of the pellet and clad in the region of the defect. The BISON fuel performance code developed at Idaho National Laboratory employs either a 2D axisymmetric or 3D representation of the full fuel rod. This allows for a computational model of the full fuel rod to include local defects. A 3D thermo-mechanical model is used to simulate the global fuel rod behavior, and includes effects on the thermal and mechanical behavior of the fuel due to accumulation of fission products, fission gas production and release, and the effects of fission gas accumulation on thermal conductivity across the fuel-clad gap. Local defects can be modeled simply by including them in the 3D fuel rod model, without the need for mapping between two separate models. This allows for the complete set of physics used in a fuel performance analysis to be included naturally in the computational representation of the local defect, and for the effects of the

  8. Effects of Surface Morphology on the 3D Topological Insulator Samarium Hexaboride

    NASA Astrophysics Data System (ADS)

    Wolgast, Steven; Eo, Yun Suk; Kurdak, Cagliyan; Kim, Dae-Jeong; Fisk, Zachary

    2015-03-01

    The recent verification of a topologically-protected surface state in SmB6 at low temperatures has led to several transport studies of the surface states. This task is complicated because current can flow on all surfaces of a topological insulator, each of which can have different transport characteristics. Our own measurements using a Corbino disc geometry overcome this difficulty, limiting the conduction to individual surfaces. However, the sheet conductivities of our samples counter-intuitively decrease with finer surface polishing. We therefore investigate surface and sub-surface morphology as a factor affecting the surface conductivity. Specifically, surface cracks may themselves harbor surface states and contribute to the total electrical conduction, yielding a higher measured sheet conductivity than that of a flat surface. This situation may contribute to the (sometimes unphysically) large surface conductivities already observed in SmB6. Performed in part at the Lurie Nanofabrication Facility and the Electron Microbeam Analysis Laboratory. Funded by NSF Grant #DMR-1006500 and DMR-1441965. Thanks to Gang Li and Fan Yu for optical imaging.

  9. Moiré deflectometry under incoherent illumination: 3D profiler for specular surfaces

    NASA Astrophysics Data System (ADS)

    Hirose, Tomohiro; Kitayama, Tsunaji

    2013-04-01

    We present a novel method for measuring a curved specular surface profile, which is the moiré deflectometry under incoherent (white light) illumination. In our proposed system, moiré is produced by a superposition of two pairs of Ronchi gratings to obtain orthogonal components of a normal vector on a surface under test. The grating pair was moved along an axis perpendicular to the grating plane to modulate a spatial frequency of the moiré. The moiré is reflected by a specular object, then observed with a calibrated stereo camera. Normal vector distribution of the tested surface was measured by analysis of intensity oscillations captured by the stereo camera as a function of the position of the moved grating. A surface profile was reconstructed by an integration calculation. We successfully measured surface profiles of deeply curved mirrors with the curvature from -20 to 20 m-1 by our system. Moreover, part of a miniature vehicle body, which has a complex curved specular surface, was also measured. Additionally, we theoretically and experimentally studied a measurable angle variation of the normal vector on the tested surface by our measurement system. We found that our system can allow to measure the angle deviation of 0.05 deg of the normal vector. This method has no ambiguity of slope and height measurements which is appeared in conventional deflectmetric metrologies. Furthermore, our proposed system only needs a single step calibration. Hence, the methodology we proposed has a potential to be developed into a 3D profiler for complex specular surfaces.

  10. Creation of quantum-degenerate gases of ytterbium in a compact 2D-/3D-magneto-optical trap setup

    SciTech Connect

    Doerscher, Soeren; Thobe, Alexander; Hundt, Bastian; Kochanke, Andre; Le Targat, Rodolphe; Windpassinger, Patrick; Becker, Christoph; Sengstock, Klaus

    2013-04-15

    We report on the first experimental setup based on a 2D-/3D-magneto-optical trap (MOT) scheme to create both Bose-Einstein condensates and degenerate Fermi gases of several ytterbium isotopes. Our setup does not require a Zeeman slower and offers the flexibility to simultaneously produce ultracold samples of other atomic species. Furthermore, the extraordinary optical access favors future experiments in optical lattices. A 2D-MOT on the strong {sup 1}S{sub 0}{yields}{sup 1}P{sub 1} transition captures ytterbium directly from a dispenser of atoms and loads a 3D-MOT on the narrow {sup 1}S{sub 0}{yields}{sup 3}P{sub 1} intercombination transition. Subsequently, atoms are transferred to a crossed optical dipole trap and cooled evaporatively to quantum degeneracy.

  11. Development of a strain analyzer system for sheet metal stamped parts based on an optical 3D digitizer

    NASA Astrophysics Data System (ADS)

    Carasusan, Eusebio; Canal, Fernando

    2003-05-01

    In this paper a new automatic strain analyzer system for sheet metal stamped parts is presented. This device is based on an optic 3D scanner working with structure white light, that performs measurements with high speed and accuracy. This new device can be a very useful tool in manufacturing industry.

  12. Comparison of two different surfaces for 3d model abstraction in support of remote sensing simulations

    SciTech Connect

    Pope, Paul A; Ranken, Doug M

    2010-01-01

    A method for abstracting a 3D model by shrinking a triangular mesh, defined upon a best fitting ellipsoid surrounding the model, onto the model's surface has been previously described. This ''shrinkwrap'' process enables a semi-regular mesh to be defined upon an object's surface. This creates a useful data structure for conducting remote sensing simulations and image processing. However, using a best fitting ellipsoid having a graticule-based tessellation to seed the shrinkwrap process suffers from a mesh which is too dense at the poles. To achieve a more regular mesh, the use of a best fitting, subdivided icosahedron was tested. By subdividing each of the twenty facets of the icosahedron into regular triangles of a predetermined size, arbitrarily dense, highly-regular starting meshes can be created. Comparisons of the meshes resulting from these two seed surfaces are described. Use of a best fitting icosahedron-based mesh as the seed surface in the shrinkwrap process is preferable to using a best fitting ellipsoid. The impacts to remote sensing simulations, specifically generation of synthetic imagery, is illustrated.

  13. White light interferometer with color CCD for 3D-surface profiling of microsystems

    NASA Astrophysics Data System (ADS)

    Upputuri, Paul K.; Pramanik, Manojit; Nandigana, Krishna M.; Kothiyal, Mahendra P.

    2015-03-01

    White light interferometry (WLI) is a state-of-the-art technique for high resolution full-filed 3-D surface profiling of Microsystems. However, the WLI is rather slow, because the number of frames to be recorded and evaluated is large compared to the single wavelength phase shifting interferometry. In this paper, we combine white light interferometer with a single-chip color CCD camera which makes the measurement faster, simpler, and cost-effective. The red-bluegreen (RGB) color interferogram stored in a computer is then decomposed into its individual components and corresponding phase maps for red, green, and blue components are calculated independently. The usefulness of the technique is demonstrated on reflective micro-scale-samples.

  14. Automatic extraction of discontinuity orientation from rock mass surface 3D point cloud

    NASA Astrophysics Data System (ADS)

    Chen, Jianqin; Zhu, Hehua; Li, Xiaojun

    2016-10-01

    This paper presents a new method for extracting discontinuity orientation automatically from rock mass surface 3D point cloud. The proposed method consists of four steps: (1) automatic grouping of discontinuity sets using an improved K-means clustering method, (2) discontinuity segmentation and optimization, (3) discontinuity plane fitting using Random Sample Consensus (RANSAC) method, and (4) coordinate transformation of discontinuity plane. The method is first validated by the point cloud of a small piece of a rock slope acquired by photogrammetry. The extracted discontinuity orientations are compared with measured ones in the field. Then it is applied to a publicly available LiDAR data of a road cut rock slope at Rockbench repository. The extracted discontinuity orientations are compared with the method proposed by Riquelme et al. (2014). The results show that the presented method is reliable and of high accuracy, and can meet the engineering needs.

  15. 3D Hydrodynamical Simulations of Evolved Stars and Observations of Stellar Surfaces

    NASA Astrophysics Data System (ADS)

    Chiavassa, A.; Freytag, B.

    2015-08-01

    Evolved stars are among the largest and brightest stars and they are ideal targets for the new generation of sensitive, high resolution instrumentation that provides spectrophotometric, interferometric, astrometric, and imaging observables. The interpretation of the complex stellar surface images requires numerical simulations of stellar convection that take into account multi-dimensional time-dependent radiation hydrodynamics with realistic input physics. We show how the evolved star simulations are obtained using the radiative hydrodynamics code CO5BOLD and how the accurate observables are computed with the post-processing radiative transfer code OPTIM3D. The synergy between observations and theoretical work is supported by a proper and quantitative analysis using these simulations, and by strong constraints from the observational side.

  16. Design of a 3D surface scanner prototype suitable for MR.

    PubMed

    Cavalleri, M; Romei, M; Reni, G

    2010-01-01

    The detection of body movements during MR examination could help in reducing motion artifacts or to get patient responses during functional magnetic resonance. It can be supported by a slit scanner, that combines a camera with a light stripe projector to obtain 3D coordinates of points forming the external surface of the body. In this work we propose a slit scanner prototype based on a miniaturized projector without moving parts. Just small sized hardware is required to analyze the video signal, operating in time domain instead of spatial domain. To accomplish this, the camera is placed with its pixel columns as more parallel as possible to the projected light stripes and the camera video signal is analyzed by a resistor transistor logic after analog processing.

  17. 3D Cloud Tomography, Followed by Mean Optical and Microphysical Properties, with Multi-Angle/Multi-Pixel Data

    NASA Astrophysics Data System (ADS)

    Davis, A. B.; von Allmen, P. A.; Marshak, A.; Bal, G.

    2010-12-01

    -type model is used where the cloud surface "emits" either reflected (sunny-side) or transmitted (shady-side) light at different levels. As it turns out, the reflected/transmitted light ratio yields an approximate cloud optical thickness. Another approach is to invoke tomography techniques to define the volume occupied by the cloud using, as it were, cloud masks for each direction of observation. In the shape and opacity refinement phase, initial guesses along with solar and viewing geometry information are used to predict radiance in each pixel using a fast diffusion model for the 3D RT in MISR's non-absorbing red channel (275 m resolution). Refinement is constrained and stopped when optimal resolution is reached. Finally, multi-pixel/mono-angle MODIS data for the same cloud (at comparable 250 m resolution) reveals the desired droplet size information, hence the volume-averaged LWC. This is an ambitious remote sensing science project drawing on cross-disciplinary expertise gained in medical imaging using both X-ray and near-IR sources and detectors. It is high risk but with potentially high returns not only for the cloud modeling community but also aerosol and surface characterization in the presence of broken 3D clouds.

  18. UAV based 3D digital surface model to estimate paleolandscape in high mountainous environment

    NASA Astrophysics Data System (ADS)

    Mészáros, János; Árvai, Mátyás; Kohán, Balázs; Deák, Márton; Nagy, Balázs

    2016-04-01

    Our method to present current state of a peat bog was focused on the possible use of a UAV-system and later Structure-from-motion algorithms as processing technique. The peat bog site is located on the Vinderel Plateau, Farcǎu Massif, Maramures Mountains (Romania). The peat bog (1530 m a.s.l., N47°54'11", E24°26'37") lies below Rugasu ridge (c. 1820 m a.s.l.) and the locality serves as a conservation area for fallen down coniferous trees. Peat deposits were formed in a landslide concavity on the western slope of Farcǎu Massif. Nowadays the site is surrounded by a completely deforested landscape, and Farcǎu Massif lies above the depressed treeline. The peat bog has an extraordinary geomorphological situation, because a gully reached the bog and drained the water. In the recent past sedimentological and dendrochronological researches have been initiated. However, an accurate 3D digital surface model also needed for a complex paleoenvironmental research. Last autumn the bog and its surroundings were finally surveyed by a multirotor UAV developed in-house based on an open-source flight management unit and its firmware. During this survey a lightweight action camera (mainly to decrease payload weight) was used to take aerial photographs. While our quadcopter is capable to fly automatically on a predefined flight route, several over- and sidelapping flight lines were generated prior to the actual survey on the ground using a control software running on a notebook. Despite those precautions, limited number of batteries and severe weather affected our final flights, resulting a reduced surveyed area around peat bog. Later, during the processing we looked for a reliable tool which powerful enough to process more than 500 photos taken during flights. After testing several software Agisoft PhotoScan was used to create 3D point cloud and mesh about bog and its environment. Due to large number of photographs PhotoScan had to be configured for network processing to get

  19. Characterization of 3D printing output using an optical sensing system

    NASA Astrophysics Data System (ADS)

    Straub, Jeremy

    2015-05-01

    This paper presents the experimental design and initial testing of a system to characterize the progress and performance of a 3D printer. The system is based on five Raspberry Pi single-board computers. It collects images of the 3D printed object, which are compared to an ideal model. The system, while suitable for printers of all sizes, can potentially be produced at a sufficiently low cost to allow its incorporation into consumer-grade printers. The efficacy and accuracy of this system is presented and discussed. The paper concludes with a discussion of the benefits of being able to characterize 3D printer performance.

  20. Analyzing the Evolution of Membrane Fouling via a Novel Method Based on 3D Optical Coherence Tomography Imaging.

    PubMed

    Li, Weiyi; Liu, Xin; Wang, Yi-Ning; Chong, Tzyy Haur; Tang, Chuyang Y; Fane, Anthony G

    2016-07-01

    The development of novel tools for studying the fouling behavior during membrane processes is critical. This work explored optical coherence tomography (OCT) to quantitatively interpret the formation of a cake layer during a membrane process; the quantitative analysis was based on a novel image processing method that was able to precisely resolve the 3D structure of the cake layer on a micrometer scale. Fouling experiments were carried out with foulants having different physicochemical characteristics (silica nanoparticles and bentonite particles). The cake layers formed at a series of times were digitalized using the OCT-based characterization. The specific deposit (cake volume/membrane surface area) and surface coverage were evaluated as a function of time, which for the first time provided direct experimental evidence for the transition of various fouling mechanisms. Axial stripes were observed in the grayscale plots showing the deposit distribution in the scanned area; this interesting observation was in agreement with the instability analysis that correlated the polarized particle groups with the small disturbances in the boundary layer. This work confirms that the OCT-based characterization is able to provide deep insights into membrane fouling processes and offers a powerful tool for exploring membrane processes with enhanced performance.

  1. ALPINE3D: a detailed model of mountain surface processes and its application to snow hydrology

    NASA Astrophysics Data System (ADS)

    Lehning, Michael; Völksch, Ingo; Gustafsson, David; Nguyen, Tuan Anh; Stähli, Manfred; Zappa, Massimiliano

    2006-06-01

    Current models of snow cover distribution, soil moisture, surface runoff and river discharge typically have very simple parameterizations of surface processes, such as degree-day factors or single-layer snow cover representation. For the purpose of reproducing catchment runoff, simple snowmelt routines have proven to be accurate, provided that they are carefully calibrated specifically for the catchment they are applied to. The use of more detailed models is, however, useful to understand and quantify the role of individual surface processes for catchment hydrology, snow cover status and soil moisture distribution.We introduce ALPINE3D, a model for the high-resolution simulation of alpine surface processes, in particular snow processes. The model can be driven by measurements from automatic weather stations or by meteorological model outputs. As a preprocessing alternative, specific high-resolution meteorological fields can be created by running a meteorological model. The core three-dimensional ALPINE3D modules consist of a radiation balance model (which uses a view-factor approach and includes shortwave scattering and longwave emission from terrain and tall vegetation) and a drifting snow model solving a diffusion equation for suspended snow and a saltation transport equation. The processes in the atmosphere are thus treated in three dimensions and are coupled to a distributed (in the hydrological sense of having a spatial representation of the catchment properties) one-dimensional model of vegetation, snow and soil (SNOWPACK) using the assumption that lateral exchange is small in these media. The model is completed by a conceptual runoff module. The model can be run with a choice of modules, thus generating more or less detailed surface forcing data as input for runoff generation simulations. The model modules can be run in a parallel (distributed) mode using a GRID infrastructure to allow computationally demanding tasks. In a case study from the Dischma Valley

  2. Understanding surface processes 3D imaging from micro-scale to regional scale

    NASA Astrophysics Data System (ADS)

    Jaboyedoff, Michel; Abellan, Antonio; Carrea, Dario; Derron, Marc-Henri; Franz, Martin; Guerin, Antoine; Humair, Florian; Matasci, Battista; Michoud, Clément; Nicolet, Pierrick; Penna, Ivanna; Rudaz, Benjamin; Voumard, Jeremie; Wyser, Emmanuel

    2015-04-01

    The production of topography using remote sensing techniques has considerably been improved during the last fifteen years due to the advances in electronics and to the increase of computing power. The earth surface is monitored at all the scales using Space Shuttle Missions (SRTM) digital elevation model (DEM), or using laser scanner (LS), both terrestrial (TLS) and airborne (ALS), with accuracies that can reach up to less than 50 microns for observations of objects at meter scale. Recently, photogrammetry has been pushed by the progress of LiDAR and thanks to the advance in image recognition. It led to the development of new techniques such as structure-from-motion (SFM), which allows obtaining 3D point cloud based on several pictures of the same object taken from several point of views. Both LiDAR and Photogrammetry produce 3D point clouds. One of the current 3D applications is the surface changes, which is often based simply on the subtraction of DEM at different time intervals, leading to a simple superficial description of the natural processes without information on the mass transport. However, a point cloud has much more information than a simple surface. For instance, shape recognition can be used to track objects or deformations such as a rock mass toppling, either using the shape of the point cloud or a specific moving element. Such method permits, for instance, to study in detail pre-failure accelerations, and are now routinely used in mining industry. Other methods are coupling images and DEMs and are used, for example, to capture the surface vectors of displacements in order to deduce the surface deformations of landslides. These types of surveys have now broad applications to all kinds of erosional processes. The coastal retreat can be monitored, and it displays in some places several centimetres per year of retreat on average. The sediment transports in torrent are now better constraint showing clearly pulses. The seasonal cycles can as well be

  3. 3D imaging of cone photoreceptors over extended time periods using optical coherence tomography with adaptive optics

    NASA Astrophysics Data System (ADS)

    Kocaoglu, Omer P.; Lee, Sangyeol; Jonnal, Ravi S.; Wang, Qiang; Herde, Ashley E.; Besecker, Jason; Gao, Weihua; Miller, Donald T.

    2011-03-01

    Optical coherence tomography with adaptive optics (AO-OCT) is a highly sensitive, noninvasive method for 3D imaging of the microscopic retina. The purpose of this study is to advance AO-OCT technology by enabling repeated imaging of cone photoreceptors over extended periods of time (days). This sort of longitudinal imaging permits monitoring of 3D cone dynamics in both normal and diseased eyes, in particular the physiological processes of disc renewal and phagocytosis, which are disrupted by retinal diseases such as age related macular degeneration and retinitis pigmentosa. For this study, the existing AO-OCT system at Indiana underwent several major hardware and software improvements to optimize system performance for 4D cone imaging. First, ultrahigh speed imaging was realized using a Basler Sprint camera. Second, a light source with adjustable spectrum was realized by integration of an Integral laser (Femto Lasers, λc=800nm, ▵λ=160nm) and spectral filters in the source arm. For cone imaging, we used a bandpass filter with λc=809nm and ▵λ=81nm (2.6 μm nominal axial resolution in tissue, and 167 KHz A-line rate using 1,408 px), which reduced the impact of eye motion compared to previous AO-OCT implementations. Third, eye motion artifacts were further reduced by custom ImageJ plugins that registered (axially and laterally) the volume videos. In two subjects, cone photoreceptors were imaged and tracked over a ten day period and their reflectance and outer segment (OS) lengths measured. High-speed imaging and image registration/dewarping were found to reduce eye motion to a fraction of a cone width (1 μm root mean square). The pattern of reflections in the cones was found to change dramatically and occurred on a spatial scale well below the resolution of clinical instruments. Normalized reflectance of connecting cilia (CC) and OS posterior tip (PT) of an exemplary cone was 54+/-4, 47+/-4, 48+/-6, 50+/-5, 56+/-1% and 46+/-4, 53+/-4, 52+/-6, 50+/-5, 44

  4. Optical low-cost and portable arrangement for full field 3D displacement measurement using a single camera

    NASA Astrophysics Data System (ADS)

    López-Alba, E.; Felipe-Sesé, L.; Schmeer, S.; Díaz, F. A.

    2016-11-01

    In the current paper, an optical low-cost system for 3D displacement measurement based on a single camera and 3D digital image correlation is presented. The conventional 3D-DIC set-up based on a two-synchronized-cameras system is compared with a proposed pseudo-stereo portable system that employs a mirror system integrated in a device for a straightforward application achieving a novel handle and flexible device for its use in many scenarios. The proposed optical system splits the image by the camera into two stereo images of the object. In order to validate this new approach and quantify its uncertainty compared to traditional 3D-DIC systems, solid rigid in and out-of-plane displacements experiments have been performed and analyzed. The differences between both systems have been studied employing an image decomposition technique which performs a full image comparison. Therefore, results of all field of view are compared with those using a stereoscopy system and 3D-DIC, discussing the accurate results obtained with the proposed device not having influence any distortion or aberration produced by the mirrors. Finally, the adaptability of the proposed system and its accuracy has been tested performing quasi-static and dynamic experiments using a silicon specimen under high deformation. Results have been compared and validated with those obtained from a conventional stereoscopy system showing an excellent level of agreement.

  5. Developed Design for Humeral Head Replacement Using 3D Surface Mapping

    NASA Astrophysics Data System (ADS)

    Salah, H. R.

    2014-12-01

    Assessment of dimensional and geometrical data on the humeral head replacement (HHR) objects is essential for solving the relevant designing problems in the physics of reverse engineering (RE). In this work, 2D-assessment for human humerus was performed using the computed tomography (CT) technique within the RE plan, after which the 2D images of humeral objects were converted into 3D images. The conversion was successful and indicated a clear difference in the 2D and 3D estimates of sizes and geometry of the humerus. The authors have analyzed and confirmed experimentally the statistical information on the relevant anatomical objects. The results of finite-element simulation of the compressive stresses affecting the geometry of 3D surface mapping were analyzed using SolidWorks software. For developing the biomechanical design of an HHR object suitable biomaterials were selected, and different metal-based biomaterials are discussed as applied at various loads. New methodology is presented for the size estimation of humeral head - both anatomical and artificial - in 3D-shape. A detailed interpretation is given for the results of CT D-measurements. Izmēru un ģeometrisko datu novērtējums, kas attiecas uz pleca kaula galviņas nomaiņas (PKGN) objektiem, nepieciešams, lai risinātu virkni reversīvās inženierijas (RI) problēmu. Šajā darbā cilvēka pleca kaula galviņas divdimensiju novērtējums tika veikts ar datortomogrāfijas palīdzību (RI) ietvaros, un pēc tam objekta divdimensiju attēlojums tika pārveidots trīsdimensiju. Pārveidojums bija sekmīgs, parādot pleca kaula galviņas izmēru un ģeometrijas atšķirības starp 2D un 3D novērtējumiem. Autori izanalizēja un eksperimentāli apstiprināja statistisko informāciju pēc dotā veida anatomiskiem objektiem. Saspiešanas sasprindzinājumi, kuri ietekmē trīsdimensiju virsmas attēlojuma ģeometriju, tika analizēti ar gala-elementu simulācijas metodi, lietojot programmu Solid

  6. Tuning 3D topography on biomimetic surface for efficient self-cleaning and microfluidic manipulation

    NASA Astrophysics Data System (ADS)

    Guan, Wei-Sheng; Huang, Han-Xiong; Chen, An-Fu

    2015-03-01

    Currently, micro-/nanotopography on polymeric replica is generally limited to 2D when a mechanical demolding approach is applied. In this work, one-step replication of bio-inspired 3D topography is achieved using microinjection compression molding with novel dual-layer molds. Using a proposed flexible template, the replica topography and wettability are highly tunable during molding. Moreover, dual-scale topography on the mold is developed by coating the micropatterned insert with submicron silica particles. Contact angle and roll-off angle measurements indicate the lotus leaf, rose petal and rice leaf effects on biomimetic surfaces. Among the three kinds of surfaces, the petal-inspired surface possesses the superior performance in self-cleaning submicron contaminants and mechanical robustness, which is highly correlated to the low roughness-induced adhesive superhydrophobicity and the absence of fragile submicron-/nanostructure, respectively. Furthermore, a multi-layer mold structure is proposed for fabricating the open microfluidic devices. The embedment of the hydrophilic and hydrophobic silica particles in the microstructured open channel and the hydrophobic silica particles in the background area during replication renders the wettability contrast sharp, realizing the self-driven flow of microfluid confined within the open microchannel.

  7. Evaluating Dense 3d Reconstruction Software Packages for Oblique Monitoring of Crop Canopy Surface

    NASA Astrophysics Data System (ADS)

    Brocks, S.; Bareth, G.

    2016-06-01

    Crop Surface Models (CSMs) are 2.5D raster surfaces representing absolute plant canopy height. Using multiple CMSs generated from data acquired at multiple time steps, a crop surface monitoring is enabled. This makes it possible to monitor crop growth over time and can be used for monitoring in-field crop growth variability which is useful in the context of high-throughput phenotyping. This study aims to evaluate several software packages for dense 3D reconstruction from multiple overlapping RGB images on field and plot-scale. A summer barley field experiment located at the Campus Klein-Altendorf of University of Bonn was observed by acquiring stereo images from an oblique angle using consumer-grade smart cameras. Two such cameras were mounted at an elevation of 10 m and acquired images for a period of two months during the growing period of 2014. The field experiment consisted of nine barley cultivars that were cultivated in multiple repetitions and nitrogen treatments. Manual plant height measurements were carried out at four dates during the observation period. The software packages Agisoft PhotoScan, VisualSfM with CMVS/PMVS2 and SURE are investigated. The point clouds are georeferenced through a set of ground control points. Where adequate results are reached, a statistical analysis is performed.

  8. Nondestructive testing of 3D disperse systems with micro- and nano-particles: N-dimensional space of optical parameters

    NASA Astrophysics Data System (ADS)

    Bezrukova, Alexandra G.

    2006-04-01

    The simultaneous analysis of 3D disperse systems (DS) with micro- and nano- particles by refractometry, absorbency, fluorescence and by different types of light scattering, can help to elaborate the sensing elements for specffic impurity control. Our research has investigated by complex of optical methods different 3D DS such as: proteins, nucleoproteids, lipoproteids, liposomes, viruses, virosomes, lipid emulsions, blood substitutes, latexes, liquid crystals, biological cells with various form and size (including bacterial cells), metallic powders, clays, kimberlites, zeolites, oils, crude oils, samples of natural and water-supply waters, etc. This experience suggests that each 3D DS can be charactensed by N-dimensional vector in N-dimensional space of optical parameters. Due to the fusion of various optical data it is possible to solve the inverse physical problem on the presence of impurity in mixtures of 3D DS by information statistical theory methods. It is important that in this case polymodality of particle size distribution is not an obstacle.

  9. Analytic 3D imaging of mammalian nucleus at nanoscale using coherent x-rays and optical fluorescence microscopy.

    PubMed

    Song, Changyong; Takagi, Masatoshi; Park, Jaehyun; Xu, Rui; Gallagher-Jones, Marcus; Imamoto, Naoko; Ishikawa, Tetsuya

    2014-09-01

    Despite the notable progress that has been made with nano-bio imaging probes, quantitative nanoscale imaging of multistructured specimens such as mammalian cells remains challenging due to their inherent structural complexity. Here, we successfully performed three-dimensional (3D) imaging of mammalian nuclei by combining coherent x-ray diffraction microscopy, explicitly visualizing nuclear substructures at several tens of nanometer resolution, and optical fluorescence microscopy, cross confirming the substructures with immunostaining. This demonstrates the successful application of coherent x-rays to obtain the 3D ultrastructure of mammalian nuclei and establishes a solid route to nanoscale imaging of complex specimens.

  10. Reproducibility of 3D kinematics and surface electromyography measurements of mastication.

    PubMed

    Remijn, Lianne; Groen, Brenda E; Speyer, Renée; van Limbeek, Jacques; Nijhuis-van der Sanden, Maria W G

    2016-03-01

    The aim of this study was to determine the measurement reproducibility for a procedure evaluating the mastication process and to estimate the smallest detectable differences of 3D kinematic and surface electromyography (sEMG) variables. Kinematics of mandible movements and sEMG activity of the masticatory muscles were obtained over two sessions with four conditions: two food textures (biscuit and bread) of two sizes (small and large). Twelve healthy adults (mean age 29.1 years) completed the study. The second to the fifth chewing cycle of 5 bites were used for analyses. The reproducibility per outcome variable was calculated with an intraclass correlation coefficient (ICC) and a Bland-Altman analysis was applied to determine the standard error of measurement relative error of measurement and smallest detectable differences of all variables. ICCs ranged from 0.71 to 0.98 for all outcome variables. The outcome variables consisted of four bite and fourteen chewing cycle variables. The relative standard error of measurement of the bite variables was up to 17.3% for 'time-to-swallow', 'time-to-transport' and 'number of chewing cycles', but ranged from 31.5% to 57.0% for 'change of chewing side'. The relative standard error of measurement ranged from 4.1% to 24.7% for chewing cycle variables and was smaller for kinematic variables than sEMG variables. In general, measurements obtained with 3D kinematics and sEMG are reproducible techniques to assess the mastication process. The duration of the chewing cycle and frequency of chewing were the best reproducible measurements. Change of chewing side could not be reproduced. The published measurement error and smallest detectable differences will aid the interpretation of the results of future clinical studies using the same study variables. PMID:26617403

  11. Reproducibility of 3D kinematics and surface electromyography measurements of mastication.

    PubMed

    Remijn, Lianne; Groen, Brenda E; Speyer, Renée; van Limbeek, Jacques; Nijhuis-van der Sanden, Maria W G

    2016-03-01

    The aim of this study was to determine the measurement reproducibility for a procedure evaluating the mastication process and to estimate the smallest detectable differences of 3D kinematic and surface electromyography (sEMG) variables. Kinematics of mandible movements and sEMG activity of the masticatory muscles were obtained over two sessions with four conditions: two food textures (biscuit and bread) of two sizes (small and large). Twelve healthy adults (mean age 29.1 years) completed the study. The second to the fifth chewing cycle of 5 bites were used for analyses. The reproducibility per outcome variable was calculated with an intraclass correlation coefficient (ICC) and a Bland-Altman analysis was applied to determine the standard error of measurement relative error of measurement and smallest detectable differences of all variables. ICCs ranged from 0.71 to 0.98 for all outcome variables. The outcome variables consisted of four bite and fourteen chewing cycle variables. The relative standard error of measurement of the bite variables was up to 17.3% for 'time-to-swallow', 'time-to-transport' and 'number of chewing cycles', but ranged from 31.5% to 57.0% for 'change of chewing side'. The relative standard error of measurement ranged from 4.1% to 24.7% for chewing cycle variables and was smaller for kinematic variables than sEMG variables. In general, measurements obtained with 3D kinematics and sEMG are reproducible techniques to assess the mastication process. The duration of the chewing cycle and frequency of chewing were the best reproducible measurements. Change of chewing side could not be reproduced. The published measurement error and smallest detectable differences will aid the interpretation of the results of future clinical studies using the same study variables.

  12. 3-D Surface Visualization of pH Titration "Topos": Equivalence Point Cliffs, Dilution Ramps, and Buffer Plateaus

    ERIC Educational Resources Information Center

    Smith, Garon C.; Hossain, Md Mainul; MacCarthy, Patrick

    2014-01-01

    3-D topographic surfaces ("topos") can be generated to visualize how pH behaves during titration and dilution procedures. The surfaces are constructed by plotting computed pH values above a composition grid with volume of base added in one direction and overall system dilution on the other. What emerge are surface features that…

  13. Building a 3D geological near surface model from borehole and laboratory data

    NASA Astrophysics Data System (ADS)

    Sala, P.; Tisato, N.; Pfiffner, O. A.; Frehner, M.

    2012-04-01

    The interpretation of active seismic survey data usually results in a subsurface P-wave velocity model. Such models commonly do not include the near surface, but end a few hundreds of meters beneath the Earth's surface. However, near surface effects, such as low-velocity zones or topography can influence the seismic signal significantly. Therefore, it is important to extend the P-wave velocity model all the way to the Earth's surface. As a test site of this study, we use the underground gas storage facility in Chémery (France), located at the south-western border of the Paris Basin. Velocities and lithological data of the shallow formations can be found in a public dataset, which collects data of a large number of short boreholes (BRGM online catalog: infoterre.brgm.fr/viewer). From the lithological data a structural model defined by surfaces gridded from well markers and faults derived from the analysis of these surfaces, is generated. The generation of the structural model comprised some major challenges, mainly because the borehole data represent 1D vertical pinpoints into the subsurface, rather than 2D sections as it is the case for most seismic surveys. This complicated the cross-correlation between the boreholes and the interpolation of the lithological formations in the 3D space. After the structural model has been generated, the velocity logs were upscaled to the model and interpolated to generate a near-surface P wave velocity model. To better constrain the velocity model, laboratory measurements of P-wave velocity were conducted. We collected 24 hand specimens from outcrops, from which we drilled core plugs. The sampled lithologies are 6 different sedimentary rock types, mostly calcarenites. The measurements were conducted employing the pulse transmission method for compression (Vp) and shear (Vs) waves in dry and fully water saturated conditions. Density and porosity were measured with two different methods: (1) with a helium pycnometer, and (2

  14. Skyrmion-induced bound states on the surface of 3D Topological Insulators

    NASA Astrophysics Data System (ADS)

    Andrikopoulos, Dimitrios; Soree, Bart

    In this work, we study the interaction between the surface state of a 3D Topological Insulator and a skyrmion magnetic texture. The skyrmion texture couples to the spin of the surface state electron with strength ΔS. Vortex and hedgehog skyrmion and anti-skyrmion structures are considered and their interaction is compared. Due to the vortex structure, the interaction of the in-plane components can be neglected and a step function is used to describe the skyrmion magnetization profile. In the hedgehog case, it is shown that the in-plane components cannot be disregarded and thus a realistic description for the skyrmion is required. Working in the micromagnetic framework, we derive a macrospin description for the skyrmion using the variational principle and then numerically solve for the bound states. It is shown that the existense and properties of these states as a function of skyrmion size, strongly depend on the skyrmion type. Both vortex and hedgehog skyrmions or anti-skyrmions can induce bound states with energies | E | < ΔS . For the hedgehog skyrmion case however, bound state appearance depends on the chirality. Finally, the probability densities in these states are computed and it is demonstrated that the electrons are localized throughout the skyrmion region. Also affiliated with imec, Belgium.

  15. RKKY interaction in P-N junction based on surface states of 3D topological insulator

    NASA Astrophysics Data System (ADS)

    Zhang, Shuhui; Yang, Wen; Chang, Kai

    The RKKY interaction mediated by conduction electrons supplies a mechanism to realize the long-range coupling of localized spins which is desired for the spin devices. Here, we examine the controllability of RKKY interaction in P-N junction (PNJ) based on surface states of 3D topological insulator (3DTI). In this study, through quantum way but not usual classical analogy to light propagation, the intuitive picture for electron waves across the interface of PNJ is obtained, e.g., Klein tunneling, negative refraction and focusing. Moreover, we perform the numerical calculations for all kinds of RKKY interaction including the Heisenberg, Ising, and Dzyaloshinskii-Moriya terms. We find the focusing of surface states leads to the local augmentation of RKKY interaction. Most importantly, a dimension transition occurs, i.e., the decay rate of RKKY interaction from the deserved 1/R 2 to 1/ R . In addition, the quadratic gate-dependence of RKKY interaction is also beneficial to the application of 3DTI PNJ in the fields of spintronics and quantum computation. This work was supported by the MOST (Grant No. 2015CB921503, and No. 2014CB848700) and NSFC (Grant No. 11434010, No. 11274036, No. 11322542, and No. 11504018).

  16. Euro-Maps 3D- A Transnational, High-Resolution Digital Surface Model For Europe

    NASA Astrophysics Data System (ADS)

    Uttenthaler, A.; Barner, F.; Hass, T.; Makiola, J.; d'Angelo, P.; Reinartz, P.; Carl, S.; Steiner, K.

    2013-12-01

    Euro-Maps 3D is a homogeneous 5 m spaced digital surface model (DSM) semi-automatically derived by Euromap from 2.5 m in-flight stereo data provided by the Indian IRS-P5 Cartosat-1 satellite. This new and innovative product has been developed in close co- operation with the Remote Sensing Technology Institute (IMF) of the German Aerospace Center (DLR) and is being jointly exploited. The very detailed and accurate representation of the surface is achieved by using a sophisticated and well adapted algorithm implemented on the basis of the Semi-Global Matching approach. In addition, the final product includes detailed flanking information consisting of several pixel-based quality and traceability layers also including an ortho layer. The product is believed to provide maximum accuracy and transparency. The DSM product meets and exceeds HRE80 qualification standards. The DSM product will be made available transnational in a homogeneous quality for most parts of Europe, North Africa and Turkey by Euromap step-by-step. Other areas around the world are processed on demand.

  17. Correlations of Surface Deformation and 3D Flow Field in a Compliant Wall Turbulent Channel Flow.

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Zhang, Cao; Katz, Joseph

    2015-11-01

    This study focuses on the correlations between surface deformation and flow features, including velocity, vorticity and pressure, in a turbulent channel flow over a flat, compliant Polydimethylsiloxane (PDMS) wall. The channel centerline velocity is 2.5 m/s, and the friction Reynolds number is 2.3x103. Analysis is based on simultaneous measurements of the time resolved 3D velocity and surface deformation using tomographic PIV and Mach-Zehnder Interferometry. The volumetric pressure distribution is calculated plane by plane by spatially integrating the material acceleration using virtual boundary, omni-directional method. Conditional sampling based on local high/low pressure and deformation events reveals the primary flow structures causing the deformation. High pressure peaks appear at the interface between sweep and ejection, whereas the negative deformations peaks (dent) appear upstream, under the sweeps. The persistent phase lag between flow and deformations are presumably caused by internal damping within the PDMS. Some of the low pressure peaks and strong ejections are located under the head of hairpin vortices, and accordingly, are associated with positive deformation (bump). Others bumps and dents are correlated with some spanwise offset large inclined quasi-streamwise vortices that are not necessarily associated with hairpins. Sponsored by ONR.

  18. Surface modeling and segmentation of the 3D airway wall in MSCT

    NASA Astrophysics Data System (ADS)

    Ortner, Margarete; Fetita, Catalin; Brillet, Pierre-Yves; Pr"teux, Françoise; Grenier, Philippe

    2011-03-01

    Airway wall remodeling in asthma and chronic obstructive pulmonary disease (COPD) is a well-known indicator of the pathology. In this context, current clinical studies aim for establishing the relationship between the airway morphological structure and its function. Multislice computed tomography (MSCT) allows morphometric assessment of airways, but requires dedicated segmentation tools for clinical exploitation. While most of the existing tools are limited to cross-section measurements, this paper develops a fully 3D approach for airway wall segmentation. Such approach relies on a deformable model which is built up as a patient-specific surface model at the level of the airway lumen and deformed to reach the outer surface of the airway wall. The deformation dynamics obey a force equilibrium in a Lagrangian framework constrained by a vector field which avoids model self-intersections. The segmentation result allows a dense quantitative investigation of the airway wall thickness with a deeper insight at bronchus subdivisions than classic cross-section methods. The developed approach has been assessed both by visual inspection of 2D cross-sections, performed by two experienced radiologists on clinical data obtained with various protocols, and by using a simulated ground truth (pulmonary CT image model). The results confirmed a robust segmentation in intra-pulmonary regions with an error in the range of the MSCT image resolution and underlined the interest of the volumetric approach versus purely 2D methods.

  19. Geometric Neural Computing for 2D Contour and 3D Surface Reconstruction

    NASA Astrophysics Data System (ADS)

    Rivera-Rovelo, Jorge; Bayro-Corrochano, Eduardo; Dillmann, Ruediger

    In this work we present an algorithm to approximate the surface of 2D or 3D objects combining concepts from geometric algebra and artificial neural networks. Our approach is based on the self-organized neural network called Growing Neural Gas (GNG), incorporating versors of the geometric algebra in its neural units; such versors are the transformations that will be determined during the training stage and then applied to a point to approximate the surface of the object. We also incorporate the information given by the generalized gradient vector flow to select automatically the input patterns, and also in the learning stage in order to improve the performance of the net. Several examples using medical images are presented, as well as images of automatic visual inspection. We compared the results obtained using snakes against the GSOM incorporating the gradient information and using versors. Such results confirm that our approach is very promising. As a second application, a kind of morphing or registration procedure is shown; namely the algorithm can be used when transforming one model at time t 1 into another at time t 2. We include also examples applying the same procedure, now extended to models based on spheres.

  20. A thermographic approach for surface crack depth evaluation through 3D finite element modeling

    NASA Astrophysics Data System (ADS)

    Basheer, Mohammed; PV, Nithin; Ravindran, Parag; Balasubramaniam, Krishnan

    2015-03-01

    Laser Thermography has been reported earlier by several researchers as a tool for detecting surface breaking cracks in metals. A high energy laser (pulsed Nd-YAG) was used to produce a highly localized thermal spot from which heat diffuses (predominantly) in the radial direction. The crack that is perpendicular to the surface and close to this thermal spot will perturb the lateral heat flow and this disturbance can be observed by an IR camera. The laser spot is then scanned over a region to map the crack; this allows remote imaging of crack morphology even in elevated temperatures. The present study involves a 3D finite element simulation using COMSOL Multiphysics as a tool to simulate the thermal flow from a pulsed laser source in the proximity of a crack. The modeling helped to understand the various parameters affecting the thermal images of laser heated spots. The influence of depth of the crack on temperature changes across the crack and the relationship between crack depth and temperature changes due to the crack was simulated and subsequently validated experimentally.

  1. Interview: bioreactors and surfaced-modified 3D-scaffolds for stem cell research.

    PubMed

    Weibezahn, Karl-Friedrich

    2008-01-01

    A Nature Editorial in 2003 asked the question "Good-bye, flat biology?" What does this question imply? In the past, many in vitro culture systems, mainly monolayer cultures, often suffered from the disadvantage that differentiated primary cells had a relatively short life-span and de-differentiated during culture. As a consequence, most of their organ-specific functions were lost rapidly. Thus, in order to reproduce better conditions for these cells in vitro, modifications and adaptations have been made to conventional monolayer cultures. The last generation of CellChips--micro-thermoformed containers--a specific technology was developed, which offers the additional possibility to modify the whole surface of the 3D formed containers. This allows a surface-patterning on a submicron scale with distinct signalling molecules. Sensors and signal electrodes may be incorporated. Applications range from basic research in cell biology to toxicology and pharmacology. Using biodegradable polymers, clinical applications become a possibility. Furthermore, the last generation of micro-thermoformed chips has been optimized to allow for cheap mass production.

  2. Interview: Bioreactors and Surfaced-Modified 3D-Scaffolds for Stem Cell Research

    PubMed Central

    Weibezahn, Karl-Friedrich

    2008-01-01

    A Nature Editorial in 2003 asked the question "Good-bye, flat biology?" What does this question imply? In the past, many in vitro culture systems, mainly monolayer cultures, often suffered from the disadvantage that differentiated primary cells had a relatively short life-span and de-differentiated during culture. As a consequence, most of their organ-specific functions were lost rapidly. Thus, in order to reproduce better conditions for these cells in vitro, modifications and adaptations have been made to conventional monolayer cultures. The last generation of CellChips -- micro-thermoformed containers -- a specific technology was developed, which offers the additional possibility to modify the whole surface of the 3D formed containers. This allows a surface-patterning on a submicron scale with distinct signalling molecules. Sensors and signal electrodes may be incorporated. Applications range from basic research in cell biology to toxicology and pharmacology. Using biodegradable polymers, clinical applications become a possibility. Furthermore, the last generation of micro-thermoformed chips has been optimized to allow for cheap mass production. PMID:19066581

  3. 3D Dynamics of Freshwater Lenses in the Near-Surface Layer of the Tropical Ocean

    NASA Astrophysics Data System (ADS)

    Soloviev, Alexander; Dean, Cayla

    2015-04-01

    Convective rains in the Intertropical Convergence Zone (ITCZ) produce lenses of freshened water on the ocean surface. These lenses are localized in space and typically involve both salinity and temperature anomalies. Due to significant density anomalies, strong pressure gradients develop, which result in lateral spreading of freshwater lenses in a form resembling gravity currents. Gravity currents inherently involve three-dimensional dynamics. As a type of organized structure, gravity currents in the upper layer of the ocean may also interact with, and be shaped by, the ambient oceanic environment and atmospheric conditions. Among the important factors are the background stratification, wind stress, wind/wave mixing and spatially coherent organized motions in the near-surface layer of the ocean. Under certain conditions, a resonant interaction between a propagating freshwater lens and internal waves in the underlying pycnocline (e.g., barrier layer) may develop, whereas interaction with wind stress may produce an asymmetry in the freshwater lens and associated mixing. These two types of interactions working in concert may explain the series of sharp frontal interfaces, which have been observed in association with freshwater lenses during TOGA COARE. In this work, we have conducted a series of numerical experiments using computational fluid dynamics tools. These numerical simulations were designed to elucidate the relationship between vertical mixing and horizontal advection of salinity under various environmental conditions and potential impact on the Aquarius and SMOS satellite image formation. Available near-surface data from field experiments served as a guidance for numerical simulations. The results of this study indicate that 3D dynamics of freshwater lenses are essential within a certain range of wind/wave conditions and the freshwater influx in the surface layer of the ocean.

  4. A compact acousto-optic lens for 2D and 3D femtosecond based 2-photon microscopy

    PubMed Central

    Kirkby, Paul A.; Naga Srinivas, N.K.M.; Silver, R. Angus

    2010-01-01

    We describe a high speed 3D Acousto-Optic Lens Microscope (AOLM) for femtosecond 2-photon imaging. By optimizing the design of the 4 AO Deflectors (AODs) and by deriving new control algorithms, we have developed a compact spherical AOL with a low temporal dispersion that enables 2-photon imaging at 10-fold lower power than previously reported. We show that the AOLM can perform high speed 2D raster-scan imaging (>150 Hz) without scan rate dependent astigmatism. It can deflect and focus a laser beam in a 3D random access sequence at 30 kHz and has an extended focusing range (>137 μm; 40X 0.8NA objective). These features are likely to make the AOLM a useful tool for studying fast physiological processes distributed in 3D space PMID:20588506

  5. A global model simulation for 3-D radiative transfer impact on surface hydrology over Sierra Nevada and Rocky Mountains

    DOE PAGES

    Lee, W. -L.; Gu, Y.; Liou, K. N.; Leung, L. R.; Hsu, H. -H.

    2014-12-15

    We investigate 3-D mountain effects on solar flux distributions and their impact on surface hydrology over the Western United States, specifically the Rocky Mountains and Sierra Nevada using CCSM4 (CAM4/CLM4) global model with a 0.23° × 0.31° resolution for simulations over 6 years. In 3-D radiative transfer parameterization, we have updated surface topography data from a resolution of 1 km to 90 m to improve parameterization accuracy. In addition, we have also modified the upward-flux deviation [3-D - PP (plane-parallel)] adjustment to ensure that energy balance at the surface is conserved in global climate simulations based on 3-D radiation parameterization.more » We show that deviations of the net surface fluxes are not only affected by 3-D mountains, but also influenced by feedbacks of cloud and snow in association with the long-term simulations. Deviations in sensible heat and surface temperature generally follow the patterns of net surface solar flux. The monthly snow water equivalent (SWE) deviations show an increase in lower elevations due to reduced snowmelt, leading to a reduction in cumulative runoff. Over higher elevation areas, negative SWE deviations are found because of increased solar radiation available at the surface. Simulated precipitation increases for lower elevations, while decreases for higher elevations with a minimum in April. Liquid runoff significantly decreases in higher elevations after April due to reduced SWE and precipitation.« less

  6. Intraoperative handheld probe for 3D imaging of pediatric benign vocal fold lesions using optical coherence tomography (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Benboujja, Fouzi; Garcia, Jordan; Beaudette, Kathy; Strupler, Mathias; Hartnick, Christopher J.; Boudoux, Caroline

    2016-02-01

    Excessive and repetitive force applied on vocal fold tissue can induce benign vocal fold lesions. Children affected suffer from chronic hoarseness. In this instance, the vibratory ability of the folds, a complex layered microanatomy, becomes impaired. Histological findings have shown that lesions produce a remodeling of sup-epithelial vocal fold layers. However, our understanding of lesion features and development is still limited. Indeed, conventional imaging techniques do not allow a non-invasive assessment of sub-epithelial integrity of the vocal fold. Furthermore, it remains challenging to differentiate these sub-epithelial lesions (such as bilateral nodules, polyps and cysts) from a clinical perspective, as their outer surfaces are relatively similar. As treatment strategy differs for each lesion type, it is critical to efficiently differentiate sub-epithelial alterations involved in benign lesions. In this study, we developed an optical coherence tomography (OCT) based handheld probe suitable for pediatric laryngological imaging. The probe allows for rapid three-dimensional imaging of vocal fold lesions. The system is adapted to allow for high-resolution intra-operative imaging. We imaged 20 patients undergoing direct laryngoscopy during which we looked at different benign pediatric pathologies such as bilateral nodules, cysts and laryngeal papillomatosis and compared them to healthy tissue. We qualitatively and quantitatively characterized laryngeal pathologies and demonstrated the added advantage of using 3D OCT imaging for lesion discrimination and margin assessment. OCT evaluation of the integrity of the vocal cord could yield to a better pediatric management of laryngeal diseases.

  7. Q AS A LITHOLOGICAL/HYDROCARBON INDICATOR: FROM FULL WAVEFORM SONIC TO 3D SURFACE SEISMIC

    SciTech Connect

    Jorge O. Parra; C.L. Hackert; L. Wilson; H.A. Collier; J. Todd Thomas

    2006-03-31

    The goal of this project was to develop a method to exploit viscoelastic rock and fluid properties to greatly enhance the sensitivity of surface seismic measurements to the presence of hydrocarbon saturation. To reach the objective, Southwest Research Institute scientists used well log, lithology, production, and 3D seismic data from an oil reservoir located on the Waggoner Ranch in north central Texas. The project was organized in three phases. In the first phase, we applied modeling techniques to investigate seismic- and acoustic-frequency wave attenuation and its effect on observable wave attributes. We also gathered existing data and acquired new data from the Waggoner Ranch field, so that all needed information was in place for the second phase. During the second phase, we developed methods to extract attenuation from borehole acoustic and surface seismic data. These methods were tested on synthetic data constructed from realistic models and real data. In the third and final phase of the project, we applied this technology to a full data set from the Waggoner site. The results presented in this Final Report show that geological conditions at the site did not allow us to obtain interpretable results from the Q processing algorithm for 3D seismic data. However, the Q-log processing algorithm was successfully applied to full waveform sonic data from the Waggoner site. A significant part of this project was technology transfer. We have published several papers and conducted presentations at professional conferences. In particular, we presented the Q-log algorithm and applications at the Society of Exploration Geophysicists (SEG) Development and Production Forum in Austin, Texas, in May 2005. The presentation attracted significant interest from the attendees and, at the request of the SEG delegates, it was placed on the Southwest Research Institute Internet site. The presentation can be obtained from the following link: http://www.swri.org/4org/d15/elecsys

  8. 3d-shell contribution to the energy loss of protons during grazing scattering from Cu(111) surfaces

    SciTech Connect

    Gravielle, M. S.; Alducin, M.; Juaristi, J. I.; Silkin, V. M.

    2007-10-15

    Motivated by a recent experimental work [S. Lederer and H. Winter, Phys. Rev. A 73, 054901 (2006)] we study the contribution of the 3d shell electrons to the energy loss of 100 keV protons scattered off from the Cu(111) surface. To describe this process we use a multiple collision formalism, where the interaction of the projectile with 3d electrons is described by means of a sequence of single encounters with atoms belonging to the first atomic layer. In order to compare the theoretical energy loss with the experimental data, we add the contribution of valence electrons, which is evaluated in linear response theory using a response function that incorporates information on the surface band structure. For completeness, the energy lost by protons is also calculated within a jellium model that includes 3d and valence electrons with equal footing. Fair agreement between theory and experiment exists when the 3d shell is taken into account in the calculation.

  9. 3D nanostar dimers with a sub-10-nm gap for single-/few-molecule surface-enhanced raman scattering.

    PubMed

    Chirumamilla, Manohar; Toma, Andrea; Gopalakrishnan, Anisha; Das, Gobind; Zaccaria, Remo Proietti; Krahne, Roman; Rondanina, Eliana; Leoncini, Marco; Liberale, Carlo; De Angelis, Francesco; Di Fabrizio, Enzo

    2014-04-16

    Plasmonic nanostar-dimers, decoupled from the substrate, have been fabricated by combining electron-beam lithography and reactive-ion etching techniques. The 3D architecture, the sharp tips of the nanostars and the sub-10 nm gap size promote the formation of giant electric-field in highly localized hot-spots. The single/few molecule detection capability of the 3D nanostar-dimers has been demonstrated by Surface-Enhanced Raman Scattering.

  10. 3D papillary image capturing by the stereo fundus camera system for clinical diagnosis on retina and optic nerve

    NASA Astrophysics Data System (ADS)

    Motta, Danilo A.; Serillo, André; de Matos, Luciana; Yasuoka, Fatima M. M.; Bagnato, Vanderlei S.; Carvalho, Luis A. V.

    2014-03-01

    Glaucoma is the second main cause of the blindness in the world and there is a tendency to increase this number due to the lifetime expectation raise of the population. Glaucoma is related to the eye conditions, which leads the damage to the optic nerve. This nerve carries visual information from eye to brain, then, if it has damage, it compromises the visual quality of the patient. In the majority cases the damage of the optic nerve is irreversible and it happens due to increase of intraocular pressure. One of main challenge for the diagnosis is to find out this disease, because any symptoms are not present in the initial stage. When is detected, it is already in the advanced stage. Currently the evaluation of the optic disc is made by sophisticated fundus camera, which is inaccessible for the majority of Brazilian population. The purpose of this project is to develop a specific fundus camera without fluorescein angiography and red-free system to accomplish 3D image of optic disc region. The innovation is the new simplified design of a stereo-optical system, in order to make capable the 3D image capture and in the same time quantitative measurements of excavation and topography of optic nerve; something the traditional fundus cameras do not do. The dedicated hardware and software is developed for this ophthalmic instrument, in order to permit quick capture and print of high resolution 3D image and videos of optic disc region (20° field-of-view) in the mydriatic and nonmydriatic mode.

  11. Artefacts for optical surface measurement

    NASA Astrophysics Data System (ADS)

    Robson, Stuart; Beraldin, J.-Angelo; Brownhill, Andrew; MacDonald, Lindsay

    2011-07-01

    Flexible manufacturing technologies are supporting the routine production of components with freeform surfaces in a wide variety of materials and surface finishes. Such surfaces may be exploited for both aesthetic and performance criteria for a wide range of industries, for example automotive, aircraft, small consumer goods and medial components. In order to ensure conformance between manufactured part and digital design it is necessary to understand, validate and promote best practice of the available measurement technologies. Similar, but currently less quantifiable, measurement requirements also exist in heritage, museum and fine art recording where objects can be individually hand crafted to extremely fine levels of detail. Optical 3D measurement systems designed for close range applications are typified by one or more illumination sources projecting a spot, line or structured light pattern onto a surface or surfaces of interest. Reflections from the projected light are detected in one or more imaging devices and measurements made concerning the location, intensity and optionally colour of the image. Coordinates of locations on the surface may be computed either directly from an understanding of the illumination and imaging geometry or indirectly through analysis of the spatial frequencies of the projected pattern. Regardless of sensing configuration some independent means is necessary to ensure that measurement capability will meet the requirements of a given level of object recording and is consistent for variations in surface properties and structure. As technologies mature, guidelines for best practice are emerging, most prominent at the current time being the German VDI/VDE 2634 and ISO/DIS 10360-8 guidelines. This considers state of the art capabilities for independent validation of optical non-contact measurement systems suited to the close range measurement of table top sized manufactured or crafted objects.

  12. The systematic and random errors determination using realtime 3D surface tracking system in breast cancer

    NASA Astrophysics Data System (ADS)

    Kanphet, J.; Suriyapee, S.; Dumrongkijudom, N.; Sanghangthum, T.; Kumkhwao, J.; Wisetrintong, M.

    2016-03-01

    The purpose of this study to determine the patient setup uncertainties in deep inspiration breath-hold (DIBH) radiation therapy for left breast cancer patients using real-time 3D surface tracking system. The six breast cancer patients treated by 6 MV photon beams from TrueBeam linear accelerator were selected. The patient setup errors and motion during treatment were observed and calculated for interfraction and intrafraction motions. The systematic and random errors were calculated in vertical, longitudinal and lateral directions. From 180 images tracking before and during treatment, the maximum systematic error of interfraction and intrafraction motions were 0.56 mm and 0.23 mm, the maximum random error of interfraction and intrafraction motions were 1.18 mm and 0.53 mm, respectively. The interfraction was more pronounce than the intrafraction, while the systematic error was less impact than random error. In conclusion the intrafraction motion error from patient setup uncertainty is about half of interfraction motion error, which is less impact due to the stability in organ movement from DIBH. The systematic reproducibility is also half of random error because of the high efficiency of modern linac machine that can reduce the systematic uncertainty effectively, while the random errors is uncontrollable.

  13. A new method for automated discontinuity trace mapping on rock mass 3D surface model

    NASA Astrophysics Data System (ADS)

    Li, Xiaojun; Chen, Jianqin; Zhu, Hehua

    2016-04-01

    This paper presents an automated discontinuity trace mapping method on a 3D surface model of rock mass. Feature points of discontinuity traces are first detected using the Normal Tensor Voting Theory, which is robust to noisy point cloud data. Discontinuity traces are then extracted from feature points in four steps: (1) trace feature point grouping, (2) trace segment growth, (3) trace segment connection, and (4) redundant trace segment removal. A sensitivity analysis is conducted to identify optimal values for the parameters used in the proposed method. The optimal triangular mesh element size is between 5 cm and 6 cm; the angle threshold in the trace segment growth step is between 70° and 90°; the angle threshold in the trace segment connection step is between 50° and 70°, and the distance threshold should be at least 15 times the mean triangular mesh element size. The method is applied to the excavation face trace mapping of a drill-and-blast tunnel. The results show that the proposed discontinuity trace mapping method is fast and effective and could be used as a supplement to traditional direct measurement of discontinuity traces.

  14. 3-D FEM Modeling of fiber/matrix interface debonding in UD composites including surface effects

    NASA Astrophysics Data System (ADS)

    Pupurs, A.; Varna, J.

    2012-02-01

    Fiber/matrix interface debond growth is one of the main mechanisms of damage evolution in unidirectional (UD) polymer composites. Because for polymer composites the fiber strain to failure is smaller than for the matrix multiple fiber breaks occur at random positions when high mechanical stress is applied to the composite. The energy released due to each fiber break is usually larger than necessary for the creation of a fiber break therefore a partial debonding of fiber/matrix interface is typically observed. Thus the stiffness reduction of UD composite is contributed both from the fiber breaks and from the interface debonds. The aim of this paper is to analyze the debond growth in carbon fiber/epoxy and glass fiber/epoxy UD composites using fracture mechanics principles by calculation of energy release rate GII. A 3-D FEM model is developed for calculation of energy release rate for fiber/matrix interface debonds at different locations in the composite including the composite surface region where the stress state differs from the one in the bulk composite. In the model individual partially debonded fiber is surrounded by matrix region and embedded in a homogenized composite.

  15. Voice Morphing Using 3D Waveform Interpolation Surfaces and Lossless Tube Area Functions

    NASA Astrophysics Data System (ADS)

    Lavner, Yizhar; Porat, Gidon

    2005-12-01

    Voice morphing is the process of producing intermediate or hybrid voices between the utterances of two speakers. It can also be defined as the process of gradually transforming the voice of one speaker to that of another. The ability to change the speaker's individual characteristics and to produce high-quality voices can be used in many applications. Examples include multimedia and video entertainment, as well as enrichment of speech databases in text-to-speech systems. In this study we present a new technique which enables production of a given number of intermediate voices or of utterances which gradually change from one voice to another. This technique is based on two components: (1) creation of a 3D prototype waveform interpolation (PWI) surface from the LPC residual signal, to produce an intermediate excitation signal; (2) a representation of the vocal tract by a lossless tube area function, and an interpolation of the parameters of the two speakers. The resulting synthesized signal sounds like a natural voice lying between the two original voices.

  16. Monitoring adipose-derived stem cells within 3D carrier by combined dielectric spectroscopy and spectral domain optical coherence topography

    NASA Astrophysics Data System (ADS)

    Bagnaninchi, P. O.

    2010-02-01

    Monitoring non-invasively the cellular events in three dimensional carriers is a major challenge for tissue engineering and regenerative medicine that prevents time-lapsed studies over large population of sample. The potential of optical coherence tomography has been demonstrated to assess tissue formation within porous matrices. In this study we explore the combination of dielectric spectroscopy (DS) and spectral domain optical coherence tomography (SDOCT) to quality assess ADSCs loaded in three dimensional carriers. A SDOCT (930nm, FWHM 90nm) was combined to an open ended coaxial probe connected to material analyser, and broadband measurements between 20MHz and 1GHz were synchronized with Labview. Both ADSCs maintained in undifferentiated state within 3D carrier and induced towards osteoblasts were monitored with this multimodality technique and their DS spectra were acquired at high cell concentration simultaneously to 3D imaging. This multimodality technique will be instrumental to assess non-invasively cell loaded carriers for cell therapy.

  17. Characterizing interstate vibrational coherent dynamics of surface adsorbed catalysts by fourth-order 3D SFG spectroscopy

    NASA Astrophysics Data System (ADS)

    Li, Yingmin; Wang, Jiaxi; Clark, Melissa L.; Kubiak, Clifford P.; Xiong, Wei

    2016-04-01

    We report the first fourth-order 3D SFG spectroscopy of a monolayer of the catalyst Re(diCN-bpy)(CO)3Cl on a gold surface. Besides measuring the vibrational coherences of single vibrational modes, the fourth-order 3D SFG spectrum also measures the dynamics of interstate coherences and vibrational coherences states between two vibrational modes. By comparing the 3D SFG to the corresponding 2D and third-order 3D IR spectroscopy of the same molecules in solution, we found that the interstate coherences exist in both liquid and surface systems, suggesting that the interstate coherence is not disrupted by surface interactions. However, by analyzing the 3D spectral lineshape, we found that the interstate coherences also experience non-negligible homogenous dephasing dynamics that originate from surface interactions. This unique ability of determining interstate vibrational coherence dynamics of the molecular monolayer can help in understanding of how energy flows within surface catalysts and other molecular monolayers.

  18. Surface amplitude data: 3D-seismic for interpretation of sea floor geology (Louisiana Slope)

    SciTech Connect

    Roberts, H.H.

    1996-09-01

    Proliferation of 3D-seismic in support of hydrocarbon exploration/production has created new data for improved interpretation of sea floor and shallow subsurface geology. Processing of digital seismic data to enhance amplitude anomalies produces information for improved assessment of geohazards and identification of sensitive benthic communities protected by environmental regulations. Coupled with high resolution acoustic data and direct observation/sampling using a manned research submersible, surface amplitude maps add critical interpretive information for identification of sea floor features. Non-reflective zones (acoustic wipeouts) are associated with many slope features. Mud diapirs, mud mounds, mud volcanoes, gas-changed sediments, gas hydrates, slump deposits, carbonate hardgrounds, and various types of carbonate mounds are all features that exhibit this common response on high resolution seismic profiles. Amplitude data help make specific identifications. Since 1988, submersible data from mid-to-upper slope features (Garden Banks, Green Canyon, and Mississippi Canyon lease block areas) have been analyzed with conventional high resolution acoustic data and 313-amplitude extraction maps. Areas of rapid venting of sediment and hydrocarbon-charged formation fluids are clearly distinguishable from mud diapirs and areas of carbonate mounds (slow seepage). Gas hydrates occur as mounds and mounded zones along faults; products of moderate flux rates below (approx.) 500 in water depths. Gas hydrates function as stored trophic resources that support sensitive chemosynthetic communities. Amplitude extraction maps clearly identify these features by a strong low impedance amplitude anomaly. Refinement and {open_quotes}field calibration{close_quotes} of the surface amplitude extraction method may eventually lead to a new standard for evaluating geohazards and sensitive benthic communities.

  19. SU-E-T-04: 3D Printed Patient-Specific Surface Mould Applicators for Brachytherapy Treatment of Superficial Lesions

    SciTech Connect

    Cumming, I; Lasso, A; Rankin, A; Fichtinger, G; Joshi, C P; Falkson, C; Schreiner, L John

    2014-06-01

    Purpose: Evaluate the feasibility of constructing 3D-printed patient-specific surface mould applicators for HDR brachytherapy treatment of superficial lesions. Methods: We propose using computer-aided design software to create 3D printed surface mould applicators for brachytherapy. A mould generation module was developed in the open-source 3D Slicer ( http://www.slicer.org ) medical image analysis platform. The system extracts the skin surface from CT images, and generates smooth catheter paths over the region of interest based on user-defined start and end points at a specified stand-off distance from the skin surface. The catheter paths are radially extended to create catheter channels that are sufficiently wide to ensure smooth insertion of catheters for a safe source travel. An outer mould surface is generated to encompass the channels. The mould is also equipped with fiducial markers to ensure its reproducible placement. A surface mould applicator with eight parallel catheter channels of 4mm diameters was fabricated for the nose region of a head phantom; flexible plastic catheters of 2mm diameter were threaded through these channels maintaining 10mm catheter separations and a 5mm stand-off distance from the skin surface. The apparatus yielded 3mm thickness of mould material between channels and the skin. The mould design was exported as a stereolithography file to a Dimension SST1200es 3D printer and printed using ABS Plus plastic material. Results: The applicator closely matched its design and was found to be sufficiently rigid without deformation during repeated application on the head phantom. Catheters were easily threaded into channels carved along catheter paths. Further tests are required to evaluate feasibility of channel diameters smaller than 4mm. Conclusion: Construction of 3D-printed mould applicators show promise for use in patient specific brachytherapy of superficial lesions. Further evaluation of 3D printing techniques and materials is required

  20. 3D non-rigid surface-based MR-TRUS registration for image-guided prostate biopsy

    NASA Astrophysics Data System (ADS)

    Sun, Yue; Qiu, Wu; Romagnoli, Cesare; Fenster, Aaron

    2014-03-01

    Two dimensional (2D) transrectal ultrasound (TRUS) guided prostate biopsy is the standard approach for definitive diagnosis of prostate cancer (PCa). However, due to the lack of image contrast of prostate tumors needed to clearly visualize early-stage PCa, prostate biopsy often results in false negatives, requiring repeat biopsies. Magnetic Resonance Imaging (MRI) has been considered to be a promising imaging modality for noninvasive identification of PCa, since it can provide a high sensitivity and specificity for the detection of early stage PCa. Our main objective is to develop and validate a registration method of 3D MR-TRUS images, allowing generation of volumetric 3D maps of targets identified in 3D MR images to be biopsied using 3D TRUS images. Our registration method first makes use of an initial rigid registration of 3D MR images to 3D TRUS images using 6 manually placed approximately corresponding landmarks in each image. Following the manual initialization, two prostate surfaces are segmented from 3D MR and TRUS images and then non-rigidly registered using a thin-plate spline (TPS) algorithm. The registration accuracy was evaluated using 4 patient images by measuring target registration error (TRE) of manually identified corresponding intrinsic fiducials (calcifications and/or cysts) in the prostates. Experimental results show that the proposed method yielded an overall mean TRE of 2.05 mm, which is favorably comparable to a clinical requirement for an error of less than 2.5 mm.

  1. 3D Surface Mapping of Capsule Fill-Tube Assemblies used in Laser-Driven Fusion Targets

    SciTech Connect

    Buice, E S; Alger, E T; Antipa, N A; Bhandarkar, S D; Biesiada, T A; Conder, A D; Dzenitis, E G; Flegel, M S; Hamza, A V; Heinbockel, C L; Horner, J; Johnson, M A; Kegelmeyer, L M; Meyer, J S; Montesanti, R C; Reynolds, J L; Taylor, J S; Wegner, P J

    2011-02-18

    This paper presents the development of a 3D surface mapping system used to measure the surface of a fusion target Capsule Fill-Tube Assembly (CFTA). The CFTA consists of a hollow Ge-doped plastic sphere, called a capsule, ranging in outer diameter between 2.2 mm and 2.6 mm and an attached 150 {micro}m diameter glass-core fill-tube that tapers down to a 10{micro} diameter at the capsule. The mapping system is an enabling technology to facilitate a quality assurance program and to archive 3D surface information of each capsule used in fusion ignition experiments that are currently being performed at the National Ignition Facility (NIF). The 3D Surface Mapping System is designed to locate and quantify surface features with a height of 50 nm and 300 nm in width or larger. Additionally, the system will be calibrated such that the 3D measured surface can be related to the capsule surface angular coordinate system to within 0.25 degree (1{sigma}), which corresponds to approximately 5 {micro}m linear error on the capsule surface.

  2. Visualization of Buffer Capacity with 3-D "Topo" Surfaces: Buffer Ridges, Equivalence Point Canyons and Dilution Ramps

    ERIC Educational Resources Information Center

    Smith, Garon C.; Hossain, Md Mainul

    2016-01-01

    BufCap TOPOS is free software that generates 3-D topographical surfaces ("topos") for acid-base equilibrium studies. It portrays pH and buffer capacity behavior during titration and dilution procedures. Topo surfaces are created by plotting computed pH and buffer capacity values above a composition grid with volume of NaOH as the x axis…

  3. Integrated ray tracing simulation of annual variation of spectral bio-signatures from cloud free 3D optical Earth model

    NASA Astrophysics Data System (ADS)

    Ryu, Dongok; Kim, Sug-Whan; Kim, Dae Wook; Lee, Jae-Min; Lee, Hanshin; Park, Won Hyun; Seong, Sehyun; Ham, Sun-Jeong

    2010-09-01

    Understanding the Earth spectral bio-signatures provides an important reference datum for accurate de-convolution of collapsed spectral signals from potential earth-like planets of other star systems. This study presents a new ray tracing computation method including an improved 3D optical earth model constructed with the coastal line and vegetation distribution data from the Global Ecological Zone (GEZ) map. Using non-Lambertian bidirectional scattering distribution function (BSDF) models, the input earth surface model is characterized with three different scattering properties and their annual variations depending on monthly changes in vegetation distribution, sea ice coverage and illumination angle. The input atmosphere model consists of one layer with Rayleigh scattering model from the sea level to 100 km in altitude and its radiative transfer characteristics is computed for four seasons using the SMART codes. The ocean scattering model is a combination of sun-glint scattering and Lambertian scattering models. The land surface scattering is defined with the semi empirical parametric kernel method used for MODIS and POLDER missions. These three component models were integrated into the final Earth model that was then incorporated into the in-house built integrated ray tracing (IRT) model capable of computing both spectral imaging and radiative transfer performance of a hypothetical space instrument as it observes the Earth from its designated orbit. The IRT model simulation inputs include variation in earth orientation, illuminated phases, and seasonal sea ice and vegetation distribution. The trial simulation runs result in the annual variations in phase dependent disk averaged spectra (DAS) and its associated bio-signatures such as NDVI. The full computational details are presented together with the resulting annual variation in DAS and its associated bio-signatures.

  4. Effects of surface reflectance and 3D shape on perceived rotation axis.

    PubMed

    Doerschner, Katja; Yilmaz, Ozgur; Kucukoglu, Gizem; Fleming, Roland W

    2013-09-10

    Surface specularity distorts the optic flow generated by a moving object in a way that provides important cues for identifying surface material properties (Doerschner, Fleming et al., 2011). Here we show that specular flow can also affect the perceived rotation axis of objects. In three experiments, we investigate how three-dimensional shape and surface material interact to affect the perceived rotation axis of unfamiliar irregularly shaped and isotropic objects. We analyze observers' patterns of errors in a rotation axis estimation task under four surface material conditions: shiny, matte textured, matte untextured, and silhouette. In addition to the expected large perceptual errors in the silhouette condition, we find that the patterns of errors for the other three material conditions differ from each other and across shape category, yielding the largest differences in error magnitude between shiny and matte, textured isotropic objects. Rotation axis estimation is a crucial implicit computational step to perceive structure from motion; therefore, we test whether a structure from a motion-based model can predict the perceived rotation axis for shiny and matte, textured objects. Our model's predictions closely follow observers' data, even yielding the same reflectance-specific perceptual errors. Unlike previous work (Caudek & Domini, 1998), our model does not rely on the assumption of affine image transformations; however, a limitation of our approach is its reliance on projected correspondence, thus having difficulty in accounting for the perceived rotation axis of smooth shaded objects and silhouettes. In general, our findings are in line with earlier research that demonstrated that shape from motion can be extracted based on several different types of optical deformation (Koenderink & Van Doorn, 1976; Norman & Todd, 1994; Norman, Todd, & Orban, 2004; Pollick, Nishida, Koike, & Kawato, 1994; Todd, 1985).

  5. Activation of electroplated-Cu surface via plasma pretreatment for low temperature Cu-Sn bonding in 3D interconnection

    NASA Astrophysics Data System (ADS)

    Wang, Junqiang; Wang, Qian; Liu, Ziyu; Wu, Zijian; Cai, Jian; Wang, Dejun

    2016-10-01

    The pretreatment with Ar mixed 5% H2 plasma was applied to improve surface properties of electroplated Cu for low temperature Cu-Sn bonding in 3D interconnection. Measurement results revealed that the Ar(5% H2) plasma effectively increased the surface activity by reducing oxygen content of the Cu surface. Lower surface roughness obtained by optimizing the pretreatment condition could help to suppress oxygen adsorption. Relationships between surface energy and surface oxygen content, surface oxygen content and surface roughness were also established. Evaluation of low temperature (200 °C) Cu-Sn bonding with optimal plasma pretreatment exhibited a defect-free interface and high shear strength.

  6. Flattop beam illumination for 3D imaging ladar with simple optical devices in the wide distance range

    NASA Astrophysics Data System (ADS)

    Tsuji, Hidenobu; Nakano, Takayuki; Matsumoto, Yoshihiro; Kameyama, Shumpei

    2016-04-01

    We have developed an illumination optical system for 3D imaging ladar (laser detection and ranging) which forms flattop beam shape by transformation of the Gaussian beam in the wide distance range. The illumination is achieved by beam division and recombination using a prism and a negative powered lens. The optimum condition of the transformation by the optical system is derived. It is confirmed that the flattop distribution can be formed in the wide range of the propagation distance from 1 to 1000 m. The experimental result with the prototype is in good agreement with the calculation result.

  7. Optical fibre sensing in metals by embedment in 3D printed metallic structures

    NASA Astrophysics Data System (ADS)

    Maier, R. R. J.; Havermann, D.; Schneller, O.; Mathew, J.; Polyzos, D.; MacPherson, W. N.; Hand, D. P.

    2014-05-01

    Additive manufacturing or 3D printing of structural components in metals has potential to revolutionise the manufacturing industry. Embedded sensing in such structures opens a route towards SMART metals, providing added functionality, intelligence and enhanced performance in many components. Such embedded sensors would be capable of operating at extremely high temperatures by utilizing regenerated fibre Bragg gratings and in-fibre Fabry-Perot cavities.

  8. Using High Frequency Focused Water-Coupled Ultrasound for 3-D Surface Depression Profiling

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Whalen, Mike F.; Hendricks, J. Lynne; Bodis, James R.

    1999-01-01

    Surface topography is an important variable in the performance of many industrial components and is normally measured with diamond-tip profilometry over a small area or using optical scattering methods for larger area measurement. A prior study was performed demonstrating that focused air-coupled ultrasound at 1 MHz was capable of profiling surfaces with 25 micron depth resolution and 400 micron lateral resolution over a 1.4 mm depth range. In this article, the question of whether higher-frequency focused water-coupled ultrasound can improve on these specifications is addressed. 10 and 25 MHz focused ultrasonic transducers were employed in the water-coupled mode. Time-of-flight images of the sample surface were acquired and converted to depth / surface profile images using the simple relation (d = V*t/2) between distance (d), time-of-flight (t), and the velocity of sound in water (V). Results are compared for the two frequencies used and with those from the 1 MHz air-coupled configuration.

  9. Pre-Processing of Point-Data from Contact and Optical 3D Digitization Sensors

    PubMed Central

    Budak, Igor; Vukelić, Djordje; Bračun, Drago; Hodolič, Janko; Soković, Mirko

    2012-01-01

    Contemporary 3D digitization systems employed by reverse engineering (RE) feature ever-growing scanning speeds with the ability to generate large quantity of points in a unit of time. Although advantageous for the quality and efficiency of RE modelling, the huge number of point datas can turn into a serious practical problem, later on, when the CAD model is generated. In addition, 3D digitization processes are very often plagued by measuring errors, which can be attributed to the very nature of measuring systems, various characteristics of the digitized objects and subjective errors by the operator, which also contribute to problems in the CAD model generation process. This paper presents an integral system for the pre-processing of point data, i.e., filtering, smoothing and reduction, based on a cross-sectional RE approach. In the course of the proposed system development, major emphasis was placed on the module for point data reduction, which was designed according to a novel approach with integrated deviation analysis and fuzzy logic reasoning. The developed system was verified through its application on three case studies, on point data from objects of versatile geometries obtained by contact and laser 3D digitization systems. The obtained results demonstrate the effectiveness of the system. PMID:22368513

  10. 2D and 3D optical diagnostic techniques applied to Madonna dei Fusi by Leonardo da Vinci

    NASA Astrophysics Data System (ADS)

    Fontana, R.; Gambino, M. C.; Greco, M.; Marras, L.; Materazzi, M.; Pampaloni, E.; Pelagotti, A.; Pezzati, L.; Poggi, P.; Sanapo, C.

    2005-06-01

    3D measurement and modelling have been traditionally applied to statues, buildings, archeological sites or similar large structures, but rarely to paintings. Recently, however, 3D measurements have been performed successfully also on easel paintings, allowing to detect and document the painting's surface. We used 3D models to integrate the results of various 2D imaging techniques on a common reference frame. These applications show how the 3D shape information, complemented with 2D colour maps as well as with other types of sensory data, provide the most interesting information. The 3D data acquisition was carried out by means of two devices: a high-resolution laser micro-profilometer, composed of a commercial distance meter mounted on a scanning device, and a laser-line scanner. The 2D data acquisitions were carried out using a scanning device for simultaneous RGB colour imaging and IR reflectography, and a UV fluorescence multispectral image acquisition system. We present here the results of the techniques described, applied to the analysis of an important painting of the Italian Reinassance: `Madonna dei Fusi', attributed to Leonardo da Vinci.

  11. Efficient near-real-time monitoring of 3D surface displacements in complex landslide scenarios

    NASA Astrophysics Data System (ADS)

    Allasia, Paolo; Manconi, Andrea; Giordan, Daniele; Baldo, Marco; Lollino, Giorgio

    2013-04-01

    Ground deformation measurements play a key role in monitoring activities of landslides. A wide spectrum of instruments and methods is nowadays available, going from in-situ to remote sensing approaches. In emergency scenarios, monitoring is often based on automated instruments capable to achieve accurate measurements, possibly with a very high temporal resolution, in order to achieve the best information about the evolution of the landslide in near-real-time, aiming at early warning purposes. However, the available tools for a rapid and efficient exploitation, understanding and interpretation of the retrieved measurements is still a challenge. This issue is particularly relevant in contexts where monitoring is fundamental to support early warning systems aimed at ensuring safety to people and/or infrastructures. Furthermore, in many cases the results obtained might be of difficult reading and divulgation, especially when people of different backgrounds are involved (e.g. scientists, authorities, civil protection operators, decision makers, etc.). In this work, we extend the concept of automatic and near real time from the acquisition of measurements to the data processing and divulgation, in order to achieve an efficient monitoring of surface displacements in landslide scenarios. We developed an algorithm that allows to go automatically and in near-real-time from the acquisition of 3D displacements on a landslide area to the efficient divulgation of the monitoring results via WEB. This set of straightforward procedures is called ADVICE (ADVanced dIsplaCement monitoring system for Early warning), and has been already successfully applied in several emergency scenarios. The algorithm includes: (i) data acquisition and transfer protocols; (ii) data collection, filtering, and validation; (iii) data analysis and restitution through a set of dedicated software, such as ©3DA [1]; (iv) recognition of displacement/velocity threshold and early warning (v) short term

  12. New method for detection of complex 3D fracture motion - Verification of an optical motion analysis system for biomechanical studies

    PubMed Central

    2012-01-01

    Background Fracture-healing depends on interfragmentary motion. For improved osteosynthesis and fracture-healing, the micromotion between fracture fragments is undergoing intensive research. The detection of 3D micromotions at the fracture gap still presents a challenge for conventional tactile measurement systems. Optical measurement systems may be easier to use than conventional systems, but, as yet, cannot guarantee accuracy. The purpose of this study was to validate the optical measurement system PONTOS 5M for use in biomechanical research, including measurement of micromotion. Methods A standardized transverse fracture model was created to detect interfragmentary motions under axial loadings of up to 200 N. Measurements were performed using the optical measurement system and compared with a conventional high-accuracy tactile system consisting of 3 standard digital dial indicators (1 μm resolution; 5 μm error limit). Results We found that the deviation in the mean average motion detection between the systems was at most 5.3 μm, indicating that detection of micromotion was possible with the optical measurement system. Furthermore, we could show two considerable advantages while using the optical measurement system. Only with the optical system interfragmentary motion could be analyzed directly at the fracture gap. Furthermore, the calibration of the optical system could be performed faster, safer and easier than that of the tactile system. Conclusion The PONTOS 5 M optical measurement system appears to be a favorable alternative to previously used tactile measurement systems for biomechanical applications. Easy handling, combined with a high accuracy for 3D detection of micromotions (≤ 5 μm), suggests the likelihood of high user acceptance. This study was performed in the context of the deployment of a new implant (dynamic locking screw; Synthes, Oberdorf, Switzerland). PMID:22405047

  13. Analysis of surface cracks at hole by a 3-D weight function method with stresses from finite element method

    NASA Technical Reports Server (NTRS)

    Zhao, W.; Newman, J. C., Jr.; Sutton, M. A.; Shivakumar, K. N.; Wu, X. R.

    1995-01-01

    Parallel with the work in Part-1, stress intensity factors for semi-elliptical surface cracks emanating from a circular hole are determined. The 3-D weight function method with the 3D finite element solutions for the uncracked stress distribution as in Part-1 is used for the analysis. Two different loading conditions, i.e. remote tension and wedge loading, are considered for a wide range in geometrical parameters. Both single and double surface cracks are studied and compared with other solutions available in the literature. Typical crack opening displacements are also provided.

  14. User's manual for FRAC3D: Supplement to report on stress analysis for structures with surface cracks

    NASA Technical Reports Server (NTRS)

    Bell, J. C.; Hopper, A. T.; Hayes, P. A.

    1978-01-01

    The FRAC3D computer program, designed for use in analyzing stresses in structures (including plates, bars, or blocks) which may contain part-circular surface cracks or embedded circular cracks is described. Instructions are provided for preparing input, including that for the supporting programs LATTICE and MATSOL as well as for FRAC3D. The course of a substantial illustrative calculation is shown with both input and output. The formulas underlying the calculations are summarized and related to the subroutines in which they are used. Many issues of strategy in using this program for analysing stresses around surface cracks are elucidated.

  15. Correlation between Optic Nerve Parameters Obtained Using 3D Nonmydriatic Retinal Camera and Optical Coherence Tomography: Interobserver Agreement on the Disc Damage Likelihood Scale.