WorldWideScience

Sample records for optical scanners

  1. Microfabrication of fiber optic scanners

    Science.gov (United States)

    Fauver, Mark; Crossman-Bosworth, Janet L.; Seibel, Eric J.

    2002-06-01

    A cantilevered optical fiber is micromachined to function as a miniature resonant opto-mechanical scanner. By driving the base of the cantilevered fiber at a resonance frequency using a piezoelectric actuator, the free end of the cantilever beam becomes a scanned light source. The fiber scanners are designed to achieve wide field-of-view (FOV) and high scan frequency. We employ a non-linearly tapered profile fiber to achieve scan amplitudes of 1 mm at scan frequencies above 20 KHz. Scan angles of over 120 degree(s) (full angle) have been achieved. Higher order modes are also employed for scanning applications that require compactness while maintaining large angular FOV. Etching techniques are used to create the non-linearly tapered sections in single mode optical fiber. Additionally, micro-lenses are fabricated on the tips of the etched fibers, with lens diameters as small as 15 microns. Such lenses are capable of reducing the divergence angle of the emitted light to 5 degree(s) (full angle), with greater reduction expected by employing novel lens shaping techniques. Microfabricated optical fiber scanners have display applications ranging from micro-optical displays to larger panoramic displays. Applications for micro-image acquisition include small barcode readers to medical endoscopes.

  2. Metal Optics For Laser Profile Scanners

    Science.gov (United States)

    Klauke, T.; Hock, F.

    1987-01-01

    Laser scanners are a valuable tool for qualitiy control in hostile hot and vibrating environments. Their high measuring speed allows time minimisation of disturbing influences. The loss of accuracy of systems due to thermal distortion could be minimised by designing mechanical-optical systems with low temperature gradients and small differences between thermal expansions of the components. For application in the forging production a laser scanner measuring in situ a series of profile lines describing the hot forging tools has been designed using aluminium for all distortion sensitive mechanical and optical components.

  3. A general solution for the registration of optical multispectral scanners

    Science.gov (United States)

    Rader, M. L.

    1974-01-01

    The paper documents a general theory for registration (mapping) of data sets gathered by optical scanners such as the ERTS satellite MSS and the Skylab S-192 MSS. This solution is generally applicable to scanners which have rotating optics. Navigation data and ground control points are used in a statistically weighted adjustment based on a mathematical model of the dynamics of the spacecraft and the scanner system. This adjustment is very similar to the well known photogrammetric adjustments used in aerial mapping. Actual tests have been completed on NASA aircraft 24 channel MSS data, and the results are very encouraging.

  4. Free-space wavelength-multiplexed optical scanner.

    Science.gov (United States)

    Yaqoob, Z; Rizvi, A A; Riza, N A

    2001-12-10

    A wavelength-multiplexed optical scanning scheme is proposed for deflecting a free-space optical beam by selection of the wavelength of the light incident on a wavelength-dispersive optical element. With fast tunable lasers or optical filters, this scanner features microsecond domain scan setting speeds and large- diameter apertures of several centimeters or more for subdegree angular scans. Analysis performed indicates an optimum scan range for a given diffraction order and grating period. Limitations include beam-spreading effects based on the varying scanner aperture sizes and the instantaneous information bandwidth of the data-carrying laser beam.

  5. Free-space wavelength-multiplexed optical scanner demonstration.

    Science.gov (United States)

    Yaqoob, Zahid; Riza, Nabeel A

    2002-09-10

    Experimental demonstration of a no-moving-parts free-space wavelength-multiplexed optical scanner (W-MOS) is presented. With fast tunable lasers or optical filters and planar wavelength dispersive elements such as diffraction gratings, this microsecond-speed scanner enables large several-centimeter apertures for subdegree angular scans. The proposed W-MOS design incorporates a unique optical amplifier and variable optical attenuator combination that enables the calibration and modulation of the scanner response, leading to any desired scanned laser beam power shaping. The experimental setup uses a tunable laser centered at 1560 nm and a 600-grooves/mm blazed reflection grating to accomplish an angular scan of 12.92 degrees as the source is tuned over an 80-nm bandwidth. The values for calculated maximum optical beam divergance, required wavelength resolution, beam-pointing accuracy, and measured scanner insertion loss are 1.076 mrad, 0.172 nm, 0.06 mrad, and 4.88 dB, respectively.

  6. A micron resolution optical scanner for characterization of silicon detectors

    Science.gov (United States)

    Shukla, R. A.; Dugad, S. R.; Garde, C. S.; Gopal, A. V.; Gupta, S. K.; Prabhu, S. S.

    2014-02-01

    The emergence of high position resolution (˜10 μm) silicon detectors in recent times have highlighted the urgent need for the development of new automated optical scanners of micron level resolution suited for characterizing microscopic features of these detectors. More specifically, for the newly developed silicon photo-multipliers (SiPM) that are compact, possessing excellent photon detection efficiency with gain comparable to photo-multiplier tube. In a short time, since their invention the SiPMs are already being widely used in several high-energy physics and astrophysics experiments as the photon readout element. The SiPM is a high quantum efficiency, multi-pixel photon counting detector with fast timing and high gain. The presence of a wide variety of photo sensitive silicon detectors with high spatial resolution requires their performance evaluation to be carried out by photon beams of very compact spot size. We have designed a high resolution optical scanner that provides a monochromatic focused beam on a target plane. The transverse size of the beam was measured by the knife-edge method to be 1.7 μm at 1 - σ level. Since the beam size was an order of magnitude smaller than the typical feature size of silicon detectors, this optical scanner can be used for selective excitation of these detectors. The design and operational details of the optical scanner, high precision programmed movement of target plane (0.1 μm) integrated with general purpose data acquisition system developed for recording static and transient response photo sensitive silicon detector are reported in this paper. Entire functionality of scanner is validated by using it for selective excitation of individual pixels in a SiPM and identifying response of active and dead regions within SiPM. Results from these studies are presented in this paper.

  7. A micron resolution optical scanner for characterization of silicon detectors.

    Science.gov (United States)

    Shukla, R A; Dugad, S R; Garde, C S; Gopal, A V; Gupta, S K; Prabhu, S S

    2014-02-01

    The emergence of high position resolution (∼10 μm) silicon detectors in recent times have highlighted the urgent need for the development of new automated optical scanners of micron level resolution suited for characterizing microscopic features of these detectors. More specifically, for the newly developed silicon photo-multipliers (SiPM) that are compact, possessing excellent photon detection efficiency with gain comparable to photo-multiplier tube. In a short time, since their invention the SiPMs are already being widely used in several high-energy physics and astrophysics experiments as the photon readout element. The SiPM is a high quantum efficiency, multi-pixel photon counting detector with fast timing and high gain. The presence of a wide variety of photo sensitive silicon detectors with high spatial resolution requires their performance evaluation to be carried out by photon beams of very compact spot size. We have designed a high resolution optical scanner that provides a monochromatic focused beam on a target plane. The transverse size of the beam was measured by the knife-edge method to be 1.7 μm at 1 - σ level. Since the beam size was an order of magnitude smaller than the typical feature size of silicon detectors, this optical scanner can be used for selective excitation of these detectors. The design and operational details of the optical scanner, high precision programmed movement of target plane (0.1 μm) integrated with general purpose data acquisition system developed for recording static and transient response photo sensitive silicon detector are reported in this paper. Entire functionality of scanner is validated by using it for selective excitation of individual pixels in a SiPM and identifying response of active and dead regions within SiPM. Results from these studies are presented in this paper.

  8. Visual stimulus presentation using fiber optics in the MRI scanner.

    Science.gov (United States)

    Huang, Ruey-Song; Sereno, Martin I

    2008-03-30

    Imaging the neural basis of visuomotor actions using fMRI is a topic of increasing interest in the field of cognitive neuroscience. One challenge is to present realistic three-dimensional (3-D) stimuli in the subject's peripersonal space inside the MRI scanner. The stimulus generating apparatus must be compatible with strong magnetic fields and must not interfere with image acquisition. Virtual 3-D stimuli can be generated with a stereo image pair projected onto screens or via binocular goggles. Here, we describe designs and implementations for automatically presenting physical 3-D stimuli (point-light targets) in peripersonal and near-face space using fiber optics in the MRI scanner. The feasibility of fiber-optic based displays was demonstrated in two experiments. The first presented a point-light array along a slanted surface near the body, and the second presented multiple point-light targets around the face. Stimuli were presented using phase-encoded paradigms in both experiments. The results suggest that fiber-optic based displays can be a complementary approach for visual stimulus presentation in the MRI scanner.

  9. Advanced optical 3D scanners using DMD technology

    Science.gov (United States)

    Muenstermann, P.; Godding, R.; Hermstein, M.

    2017-02-01

    Optical 3D measurement techniques are state-of-the-art for highly precise, non-contact surface scanners - not only in industrial development, but also in near-production and even in-line configurations. The need for automated systems with very high accuracy and clear implementation of national precision standards is growing extremely due to expanding international quality guidelines, increasing production transparency and new concepts related to the demands of the fourth industrial revolution. The presentation gives an overview about the present technical concepts for optical 3D scanners and their benefit for customers and various different applications - not only in quality control, but also in design centers or in medical applications. The advantages of DMD-based systems will be discussed and compared to other approaches. Looking at today's 3D scanner market, there is a confusing amount of solutions varying from lowprice solutions to high end systems. Many of them are linked to a very special target group or to special applications. The article will clarify the differences of the approaches and will discuss some key features which are necessary to render optical measurement systems suitable for industrial environments. The paper will be completed by examples for DMDbased systems, e. g. RGB true-color systems with very high accuracy like the StereoScan neo of AICON 3D Systems. Typical applications and the benefits for customers using such systems are described.

  10. A biaxial PZT optical scanner for pico-projector applications

    Science.gov (United States)

    Ikegami, K.; Koyama, T.; Saito, T.; Yasuda, Y.; Toshiyoshi, H.

    2015-02-01

    We report a newly developed two-dimensional MEMS optical scanner based on the ADRIP (Arc Discharge Reactive Ion-Plating) deposited piezoelectric PZT film of typical 4 μm. A circular mirror of 1.2 mm in diameter is suspended within a pair of resonant mechanism that oscillates at 25 kHz for ±12° mechanical angle with a typical voltage of 10 V. A gimbal plate including the mirror is supported with another pair of meandering suspensions to tilt the plate in the orthogonal direction at 60 Hz for the off-resonant vertical motion of ±8° mechanical. Overall power consumption of the piezoelectric actuation was 100 mW or less. As a mechanical reinforce, a rib-structure was designed on the backside of the mirror by using a structural optimization tool TOSCA to suppress the dynamic curvature to 100 nm or less. A piezoelectric sensor was also integrated in the identical PZT film after optimizing the electrode shape to pick up the mechanical angle of the scanner and to give a trigger signal to the control system. A plug-in type pico-projector optics and electronics has been assembled in a 7.5 cm × 12 cm × 5 cm volume with RGB lasers to demonstrate a HD (high definition) class image projection of 720 horizontal lines. The fundamental resonance of the entire scanner mechanism was made to be 1 kHz or higher, thereby exhibiting a compatibility with vehicle applications.

  11. A noble refractive optical scanner with linear response

    Science.gov (United States)

    Mega, Yair J.; Lai, Zhenhua; DiMarzio, Charles A.

    2013-03-01

    Many applications in various fields of science and engineering use steered optical beam systems. Currently, many methods utilize mirrors in order to steer the beam. However, this approach is an off-axis solution, which normally increases the total size of the system as well as its error and complexity. Other methods use a "Risely Prisms" based solution, which is on-axis solution, however it poses some difficulties from an engineering standpoint, and therefore isn't widely used. We present here a novel technique for steering a beam on its optical axis with a linear deflection response. We derived the formulation for the profile required of the refractive optical component necessary for preforming the beam steering. The functionality of the device was simulated analytically using Matlab, as well as using a ray-tracing software, Zemax, and showed agreement with the analytical model. An optical element was manufactured based on the proposed design and the device was tested. The results show agreement with our hypothesis. We also present some proposed geometries of the several other devices, all based on the same concept, which can be used for higher performance applications such as two-dimensional scanner, video rate scanner etc.

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

    Science.gov (United States)

    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. Evaluation of Fingerprint Images Captured by Optical Fingerprint Scanner

    Science.gov (United States)

    Takeuchi, Hideyo; Matsumoto, Noriyuki; Kuwayama, Kiyoaki; Umezaki, Taizo

    In this paper, we propose the way to evaluate fingerprint image-quality and how to discriminate remnants from captured images. First, we investigate evaluating fingerprint image-quality. Fingerprint image-quality can be digitized using the "measure" we proposed. We simulate using the dataset consists of 1425 fingerprint images captured from 57 people in Feb, which contains a lot of faded images. In the simulation using all our database, recognition rate is 95.6% while type II error is 0.01%. Recognition rate is improved to 98.1%, with rejecting 3.7% faded images evaluated by our measure from the database. Recognition rate is improved to 99.6%, rejecting 14.2% faded images. And we investigate the way to apply the measure of image-quality to fingerprint verification device with customer’s satisfaction in real world. Next we propose the way to discriminate between remnants and fingerprint images captured from optical scanner by using frequency analysis. We can perfectly prevent the fingerprint verification device from malfunctioning caused by remnant, when strong flashlight or direct sunlight slant in optical scanner in real world.

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

    Science.gov (United States)

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

    2013-12-21

    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.

  15. The optimal optical readout for the x-ray light valve—Document scanners

    OpenAIRE

    Oakham, P.; MacDougall, Robert D.; Rowlands, J. A.

    2008-01-01

    The x-ray light valve (XLV) is a novel, potentially low-cost, x-ray detector that converts an x-ray exposure into an optical image stored in a liquid crystal cell. This optical image is then transferred from the liquid crystal cell to a computer through an optical-to-digital imaging readout system. Previously, CCD-based cameras were used for the optical readout, but recently it was proposed that an inexpensive optical scanner, such as an office document scanner, is a better match to the optic...

  16. Laser identification system based on acousto-optical barcode scanner principles

    Science.gov (United States)

    Khansuvarov, Ruslan A.; Korol, Georgy I.; Preslenev, Leonid N.; Bestugin, Aleksandr R.; Paraskun, Arthur S.

    2016-09-01

    The main purpose of the bar code in the modern world is the unique identification of the product, service, or any of their features, so personal and stationary barcode scanners so widely used. One of the important parameters of bar code scanners is their reliability, accuracy of the barcode recognition, response time and performance. Nowadays, the most popular personal barcode scanners contain a mechanical part, which extremely impairs the reliability indices. Group of SUAI engineers has proposed bar code scanner based on laser beam acoustic deflection effect in crystals [RU patent No 156009 issued 4/16/2015] Through the use of an acousto-optic deflector element in barcode scanner described by a group of engineers SUAI, it can be implemented in the manual form factor, and the stationary form factor of a barcode scanner. Being a wave electronic device, an acousto-optic element in the composition of the acousto-optic barcode scanner allows you to clearly establish a mathematical link between the encoded function of the bar code with the accepted input photodetector intensities function that allows you to speak about the great probability of a bar code clear definition. This paper provides a description of the issued patent, the description of the principles of operation based on the mathematical analysis, a description of the layout of the implemented scanner.

  17. Electro-Optic Laser Scanners for Space-Based Lidar Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this phase II SBIR is to design and build new non-mechanical, electro-optic (EO) laser scanners that will be suitable for space based laser ranging,...

  18. Electro-Optic Laser Scanners for Space-Based Lidar Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Vescent Photonics propose to design and build revolutionary non-mechanical, electro-optic (EO) laser scanners that will be suitable for space based laser ranging,...

  19. Scanners, optical character readers, Cyrillic alphabet and Russian translations

    Science.gov (United States)

    Johnson, Gordon G.

    1995-01-01

    The writing of code for capture, in a uniform format, of bit maps of words and characters from scanner PICT files is presented. The coding of Dynamic Pattern Matched for the identification of the characters, words and sentences in preparation for translation is discussed.

  20. Applicability of optical scanner method for fine root dynamics

    Science.gov (United States)

    Kume, Tomonori; Ohashi, Mizue; Makita, Naoki; Khoon Kho, Lip; Katayama, Ayumi; Matsumoto, Kazuho; Ikeno, Hidetoshi

    2016-04-01

    Fine root dynamics is one of the important components in forest carbon cycling, as ~60 % of tree photosynthetic production can be allocated to root growth and metabolic activities. Various techniques have been developed for monitoring fine root biomass, production, mortality in order to understand carbon pools and fluxes resulting from fine roots dynamics. The minirhizotron method is now a widely used technique, in which a transparent tube is inserted into the soil and researchers count an increase and decrease of roots along the tube using images taken by a minirhizotron camera or minirhizotron video camera inside the tube. This method allows us to observe root behavior directly without destruction, but has several weaknesses; e.g., the difficulty of scaling up the results to stand level because of the small observation windows. Also, most of the image analysis are performed manually, which may yield insufficient quantitative and objective data. Recently, scanner method has been proposed, which can produce much bigger-size images (A4-size) with lower cost than those of the minirhizotron methods. However, laborious and time-consuming image analysis still limits the applicability of this method. In this study, therefore, we aimed to develop a new protocol for scanner image analysis to extract root behavior in soil. We evaluated applicability of this method in two ways; 1) the impact of different observers including root-study professionals, semi- and non-professionals on the detected results of root dynamics such as abundance, growth, and decomposition, and 2) the impact of window size on the results using a random sampling basis exercise. We applied our new protocol to analyze temporal changes of root behavior from sequential scanner images derived from a Bornean tropical forests. The results detected by the six observers showed considerable concordance in temporal changes in the abundance and the growth of fine roots but less in the decomposition. We also examined

  1. A modified commercial scanner as an image plate for table-top optical applications

    Energy Technology Data Exchange (ETDEWEB)

    Casado-Rojo, S; Lorenzana, H E; Baonza, V G

    2008-12-09

    A reliable, accurate, and inexpensive optical detector for table-top applications is described here. Based on a commercial high resolution office scanner coupled to a projection on plate, it enables a large image plate surface, allowing recording of large images without systematic errors associated to coupling optics' aberrations. Several tests on distance-dependent and steady interference patterns will be presented and discussed. The extension to other types of optical measurement by substituting the projection on plate is proposed.

  2. An innovative optical and chemical drill core scanner

    Science.gov (United States)

    Sjöqvist, A. S. L.; Arthursson, M.; Lundström, A.; Calderón Estrada, E.; Inerfeldt, A.; Lorenz, H.

    2015-05-01

    We describe a new innovative drill core scanner that semi-automatedly analyses drill cores directly in drill core trays with X-ray fluorescence spectrometry, without the need for much sample preparation or operator intervention. The instrument is fed with entire core trays, which are photographed at high resolution and scanned by a 3-D profiling laser. Algorithms recognise the geometry of the core tray, number of slots, location of the drill cores, calculate the optimal scanning path, and execute a continuous XRF analysis of 2 cm width along the core. The instrument is equipped with critical analytical components that allow an effective QA/QC routine to be implemented. It is a mobile instrument that can be manoeuvred by a single person with a manual pallet jack.

  3. Step-height measurements on sand surfaces: A comparison between optical scanner and coordinate measuring machine

    DEFF Research Database (Denmark)

    Mohaghegh, Kamran; Yazdanbakhsh, Seyed Alireza; Tiedje, Niels Skat

    2016-01-01

    the same routine to touch the different positions on the polygonised mesh. Each measurement was repeated 5 times. The results of step height measurements on sand surfaces showed a maximum error of ± 12 µm for CMM, while scanner shows only ± 4 µm. Generally speaking, optical step height values were measured...

  4. Reliability and validity of measurements of facial swelling with a stereophotogrammetry optical three-dimensional scanner

    NARCIS (Netherlands)

    van der Meer, Wicher J.; Dijkstra, Pieter U.; Visser, Anita; Vissink, Arjan; Ren, Yijin

    2014-01-01

    Volume changes in facial morphology can be assessed using the 3dMD DSP400 stereo-optical 3-dimensional scanner, which uses visible light and has a short scanning time. Its reliability and validity have not to our knowledge been investigated for the assessment of facial swelling. Our aim therefore wa

  5. Fabrication of Diffractive Optical Elements for an Integrated Compact Optical-MEMS Laser Scanner

    Energy Technology Data Exchange (ETDEWEB)

    WENDT,JOEL R.; KRYGOWSKI,T.W.; VAWTER,GREGORY A.; SPAHN,OLGA B.; SWEATT,WILLIAM C.; WARREN,MIAL E.; REYES,DAVID NMN

    2000-07-13

    The authors describe the microfabrication of a multi-level diffractive optical element (DOE) onto a micro-electromechanical system (MEMS) as a key element in an integrated compact optical-MEMS laser scanner. The DOE is a four-level off-axis microlens fabricated onto a movable polysilicon shuttle. The microlens is patterned by electron beam lithography and etched by reactive ion beam etching. The DOE was fabricated on two generations of MEMS components. The first generation design uses a shuttle suspended on springs and displaced by a linear rack. The second generation design uses a shuttle guided by roller bearings and driven by a single reciprocating gear. Both the linear rack and the reciprocating gear are driven by a microengine assembly. The compact design is based on mounting the MEMS module and a vertical cavity surface emitting laser (VCSEL) onto a fused silica substrate that contains the rest of the optical system. The estimated scan range of the system is {+-}4{degree} with a spot size of 0.5 mm.

  6. 3D optical two-mirror scanner with focus-tunable lens.

    Science.gov (United States)

    Pokorny, Petr; Miks, Antonin

    2015-08-01

    The paper presents formulas for a ray tracing in the optical system of two-mirror optical scanner with a focus-tunable lens. Furthermore, equations for the calculation of focal length which ensure focusing of a beam in the desired point in a detection plane are derived. The uncertainty description of such focal length follows as well. The chosen vector approach is general; therefore, the application of formulas in various configurations of the optical systems is possible. In the example situation, the authors derived formulas for mirrors' rotations and the focal length depending on the position of the point in the detection plane.

  7. Fast beam steering with full polarization control using a galvanometric optical scanner and polarization controller

    CERN Document Server

    Jofre, M; Steinlechner, F; Oliverio, N; Torres, J P; Pruneri, V; Mitchell, M W; 10.1364/OE.20.012247

    2012-01-01

    Optical beam steering is a key element in many industrial and scientific applications like in material processing, information technologies, medical imaging and laser display. Even though galvanometer-based scanners offer flexibility, speed and accuracy at a relatively low cost, they still lack the necessary control over the polarization required for certain applications. We report on the development of a polarization steerable system assembled with a fiber polarization controller and a galvanometric scanner, both controlled by a digital signal processor board. The system implements control of the polarization decoupled from the pointing direction through a feed-forward control scheme. This enables to direct optical beams to a desired direction without affecting its initial polarization state. When considering the full working field of view, we are able to compensate polarization angle errors larger than 0.2 rad, in a temporal window of less than $\\sim 20$ ms. Given the unification of components to fully cont...

  8. Monitoring of Landslide at Tuncbilek Open Pit Stripping Area with Terrestrial Laser Scanner and Optical Images

    Science.gov (United States)

    Ozdogan, Mehmet Volkan; Hamdi Deliormanli, Ahmet

    2016-10-01

    Remote sensing techniques used for providing data on earth sciences have rapidly developed in recent years. Usage of remote sensing for monitoring of slopes have made a lot of progress in the last decade. The most important benefit of remote sensing applications on slope monitoring is safe working conditions with high accurate results. Terrestrial laser scanners are one of the ground-based remote sensing equipment which provide detailed and highly accurate 3D data. In this study terrestrial laser scanner method was carried out for monitoring the landslide at Tuncbilek Open pit stripping area and also optical images were evaluated for determining the development of landslide. The head part of landslide was measured with terrestrial laser scanner at three various dates and the point cloud of head part of landslide were created. Then the three-point cloud were compared. Also six optical satellite image with resolution 1m and below were examined for determining the development of landslide between 2001 and 2013

  9. Optical coordinate scanners applied for the inspection of large scale housings produced in foundry technology

    Directory of Open Access Journals (Sweden)

    M. Grzelka

    2010-01-01

    Full Text Available The paper presents possibilities of the dimensional and geometry measurement of the large scale casting details with a coordinate measuring technique. In particular, the analysis has been devoted to the measurement strategy in case of the measurement of large scale detail (larger than 1000 mm made in foundry technology, with the 3D optical scanner. The attention was paid on the possibility created by the advanced software attached to the scanner for measurement data processing. Preparation to the geometrical accuracy analysis of the measured objects consisted of the identification of particular geometrical features based on the large number of probing points, as well as the creation of the coordinate systems derived from the best-fitting algorithms which calculate the inscribed or circumscribed geometrical elements. Analysis of accuracy in every probing point has been performed through the comparison of their coordinates with nominal values set by 3D model. Application of the 3D optical coordinate scanner with advanced measurement software for the manufacturing accuracy inspection is very useful in case of large scale details produced with foundry technologies and allows to carry out full accuracy analysis of the examined detail.

  10. Scanner-free and wide-field endoscopic imaging by using a single multimode optical fiber

    Science.gov (United States)

    Choi, Youngwoon; Yoon, Changhyeong; Kim, Moonseok; Yang, Taeseok Daniel; Fang-Yen, Christopher; Dasari, Ramachandra R.; Lee, Kyoung Jin; Choi, Wonshik

    2013-01-01

    A single multimode fiber has been considered an ideal optical element for endoscopic imaging due to the possibility of the direct image transmission via multiple spatial modes. However, the wave distortion induced by the mode dispersion has been a fundamental limitation. In this Letter, we proposed a method for eliminating the effect of the mode dispersion and therefore realized wide-field endoscopic imaging by using only a single multimode fiber with no scanner attached to the fiber. Our method will potentially revolutionize endoscopy in various fields encompassing medicine and industry. PMID:23215488

  11. Does restorer need a scanner? Optical methods in canvas painting diagnostic

    Science.gov (United States)

    Górecka, Katarzyna; Rzeszutek, Aleksandra

    2015-09-01

    The principal rule of the conservation process is an individual approach to every piece of art. Easel paintings are varying regarding their forms (shape), technique and technology and behave differently in various conditions. In order to carry out initial researches of the particular object several noninvasive analyzes are performed. However, none of these methods give information about geometric shape of the object and metric analysis of its surface. This gap in the field of initial optical analysis, may be filled with optical 3D scanning. From conservators' point of view, we may say that a laser scanner slowly becomes an indispensable and daily work tool in the diagnosis and conservation methodology of the canvas paintings.

  12. Phame: a novel phase metrology tool of Carl Zeiss for in-die phase measurements under scanner relevant optical settings

    Science.gov (United States)

    Perlitz, Sascha; Buttgereit, Ute; Scherübl, Thomas

    2007-03-01

    Meeting the demands of the lithography mask manufacturing industry moving toward 45nm and 32nm node for in-die phase metrology on phase shifting masks, Zeiss is currently developing an optical phase measurement tool (Phame TM), providing the capability of extending process control from large CD test features to in-die phase shifting features with high spatial resolution. In collaboration with Intel, the necessity of designing this optical metrology tool according to the optical setup of a lithographic exposure tool (scanner) has been researched to be fundamental for the acquisition of phase information generated from features the size of the used wavelength. Main cause is the dependence of the image phase of a scanner on polarization and the angle of incidence of the illumination light due to rigorous effects, and on the imaging NA of the scanner due to the loss of phase information in the imaging pupil. The resulting scanner phase in the image plane only coincides with the etch-depth equivalent phase for large test features, exceeding the size of the in-die feature by an order of magnitude. In this paper we introduce the Phame TM phase metrology tool, using a 193nm light source with the optical capability of phase measurement at scanner NA up to the equivalent of a NA1.6 immersion scanner, under varying, scanner relevant angle of incidence for EAPSMs and CPLs, and with the possibility of polarizing the illuminating light. New options for phase shifting mask process control on in-die features will be outlined with first measurement results.

  13. Fast, high-resolution 3D dosimetry utilizing a novel optical-CT scanner incorporating tertiary telecentric collimation

    OpenAIRE

    Sakhalkar, H. S.; Oldham, M

    2008-01-01

    This study introduces a charge coupled device (CCD) area detector based optical-computed tomography (optical-CT) scanner for comprehensive verification of radiation dose distributions recorded in nonscattering radiochromic dosimeters. Defining characteristics include: (i) a very fast scanning time of ~5 min to acquire a complete three-dimensional (3D) dataset, (ii) improved image formation through the use of custom telecentric optics, which ensures accurate projection images and minimizes art...

  14. Fiber optic video monitoring system for remote CT/MR scanners clinically accepted

    Science.gov (United States)

    Tecotzky, Raymond H.; Bazzill, Todd M.; Eldredge, Sandra L.; Tagawa, James; Sayre, James W.

    1992-07-01

    With the proliferation of CT travel to distant scanners to review images before their patients can be released. We designed a fiber-optic broadband video system to transmit images from seven scanner consoles to fourteen remote monitoring stations in real time. This system has been used clinically by radiologists for over one years. We designed and conducted a user survey to categorize the levels of system use by section (Chest, GI, GU, Bone, Neuro, Peds, etc.), to measure operational utilization and acceptance of the system into the clinical environment, to clarify the system''s importance as a clinical tool for saving radiologists travel-time to distant CT the system''s performance and limitations as a diagnostic tool. The study was administered directly to radiologists using a printed survey form. The results of the survey''s compiled data show a high percentage of system usage by a wide spectrum of radiologists. Clearly, this system has been accepted into the clinical environment as a highly valued diagnostic tool in terms of time savings and functional flexibility.

  15. 3D micro-optical lens scanner made by multi-wafer bonding technology

    Science.gov (United States)

    Bargiel, S.; Gorecki, C.; Barański, M.; Passilly, N.; Wiemer, M.; Jia, C.; Frömel, J.

    2013-03-01

    We present the preliminary design, construction and technology of a microoptical, millimeter-size 3-D microlens scanner, which is a key-component for a number of optical on-chip microscopes with emphasis on the architecture of confocal microscope. The construction of the device relies on the vertical integration of micromachined building blocks: top glass lid, silicon electrostatic comb-drive X-Y and Z microactuators with integrated scanning microlenses, ceramic LTCC spacer, and bottom lid with focusing microlens. All components are connected on the wafer level only by sequential anodic bonding. The technology of through wafer vias is applied to create electrical connections through a stack of wafers. More generally, the presented bonding/connection technologies are also of a great importance for the development of various silicon-based devices based on vertical integration scheme. This approach offers a space-effective integration of complex MOEMS devices and an effective integration of various heterogeneous technologies.

  16. Multimodal photoacoustic and optical coherence tomography scanner using an all optical detection scheme for 3D morphological skin imaging.

    Science.gov (United States)

    Zhang, Edward Z; Povazay, Boris; Laufer, Jan; Alex, Aneesh; Hofer, Bernd; Pedley, Barbara; Glittenberg, Carl; Treeby, Bradley; Cox, Ben; Beard, Paul; Drexler, Wolfgang

    2011-08-01

    A noninvasive, multimodal photoacoustic and optical coherence tomography (PAT/OCT) scanner for three-dimensional in vivo (3D) skin imaging is described. The system employs an integrated, all optical detection scheme for both modalities in backward mode utilizing a shared 2D optical scanner with a field-of-view of ~13 × 13 mm(2). The photoacoustic waves were detected using a Fabry Perot polymer film ultrasound sensor placed on the surface of the skin. The sensor is transparent in the spectral range 590-1200 nm. This permits the photoacoustic excitation beam (670-680 nm) and the OCT probe beam (1050 nm) to be transmitted through the sensor head and into the underlying tissue thus providing a backward mode imaging configuration. The respective OCT and PAT axial resolutions were 8 and 20 µm and the lateral resolutions were 18 and 50-100 µm. The system provides greater penetration depth than previous combined PA/OCT devices due to the longer wavelength of the OCT beam (1050 nm rather than 829-870 nm) and by operating in the tomographic rather than the optical resolution mode of photoacoustic imaging. Three-dimensional in vivo images of the vasculature and the surrounding tissue micro-morphology in murine and human skin were acquired. These studies demonstrated the complementary contrast and tissue information provided by each modality for high-resolution 3D imaging of vascular structures to depths of up to 5 mm. Potential applications include characterizing skin conditions such as tumors, vascular lesions, soft tissue damage such as burns and wounds, inflammatory conditions such as dermatitis and other superficial tissue abnormalities.

  17. Portable optical fiber probe-based spectroscopic scanner for rapid cancer diagnosis: a new tool for intraoperative margin assessment.

    Science.gov (United States)

    Lue, Niyom; Kang, Jeon Woong; Yu, Chung-Chieh; Barman, Ishan; Dingari, Narahara Chari; Feld, Michael S; Dasari, Ramachandra R; Fitzmaurice, Maryann

    2012-01-01

    There continues to be a significant clinical need for rapid and reliable intraoperative margin assessment during cancer surgery. Here we describe a portable, quantitative, optical fiber probe-based, spectroscopic tissue scanner designed for intraoperative diagnostic imaging of surgical margins, which we tested in a proof of concept study in human tissue for breast cancer diagnosis. The tissue scanner combines both diffuse reflectance spectroscopy (DRS) and intrinsic fluorescence spectroscopy (IFS), and has hyperspectral imaging capability, acquiring full DRS and IFS spectra for each scanned image pixel. Modeling of the DRS and IFS spectra yields quantitative parameters that reflect the metabolic, biochemical and morphological state of tissue, which are translated into disease diagnosis. The tissue scanner has high spatial resolution (0.25 mm) over a wide field of view (10 cm × 10 cm), and both high spectral resolution (2 nm) and high spectral contrast, readily distinguishing tissues with widely varying optical properties (bone, skeletal muscle, fat and connective tissue). Tissue-simulating phantom experiments confirm that the tissue scanner can quantitatively measure spectral parameters, such as hemoglobin concentration, in a physiologically relevant range with a high degree of accuracy (tissues showed that the tissue scanner can detect small foci of breast cancer in a background of normal breast tissue. This tissue scanner is simpler in design, images a larger field of view at higher resolution and provides a more physically meaningful tissue diagnosis than other spectroscopic imaging systems currently reported in literatures. We believe this spectroscopic tissue scanner can provide real-time, comprehensive diagnostic imaging of surgical margins in excised tissues, overcoming the sampling limitation in current histopathology margin assessment. As such it is a significant step in the development of a platform technology for intraoperative management of cancer, a

  18. Portable optical fiber probe-based spectroscopic scanner for rapid cancer diagnosis: a new tool for intraoperative margin assessment.

    Directory of Open Access Journals (Sweden)

    Niyom Lue

    Full Text Available There continues to be a significant clinical need for rapid and reliable intraoperative margin assessment during cancer surgery. Here we describe a portable, quantitative, optical fiber probe-based, spectroscopic tissue scanner designed for intraoperative diagnostic imaging of surgical margins, which we tested in a proof of concept study in human tissue for breast cancer diagnosis. The tissue scanner combines both diffuse reflectance spectroscopy (DRS and intrinsic fluorescence spectroscopy (IFS, and has hyperspectral imaging capability, acquiring full DRS and IFS spectra for each scanned image pixel. Modeling of the DRS and IFS spectra yields quantitative parameters that reflect the metabolic, biochemical and morphological state of tissue, which are translated into disease diagnosis. The tissue scanner has high spatial resolution (0.25 mm over a wide field of view (10 cm × 10 cm, and both high spectral resolution (2 nm and high spectral contrast, readily distinguishing tissues with widely varying optical properties (bone, skeletal muscle, fat and connective tissue. Tissue-simulating phantom experiments confirm that the tissue scanner can quantitatively measure spectral parameters, such as hemoglobin concentration, in a physiologically relevant range with a high degree of accuracy (<5% error. Finally, studies using human breast tissues showed that the tissue scanner can detect small foci of breast cancer in a background of normal breast tissue. This tissue scanner is simpler in design, images a larger field of view at higher resolution and provides a more physically meaningful tissue diagnosis than other spectroscopic imaging systems currently reported in literatures. We believe this spectroscopic tissue scanner can provide real-time, comprehensive diagnostic imaging of surgical margins in excised tissues, overcoming the sampling limitation in current histopathology margin assessment. As such it is a significant step in the development of a

  19. Fast, high-resolution 3D dosimetry utilizing a novel optical-CT scanner incorporating tertiary telecentric collimation.

    Science.gov (United States)

    Sakhalkar, H S; Oldham, M

    2008-01-01

    This study introduces a charge coupled device (CCD) area detector based optical-computed tomography (optical-CT) scanner for comprehensive verification of radiation dose distributions recorded in nonscattering radiochromic dosimeters. Defining characteristics include: (i) a very fast scanning time of approximately 5 min to acquire a complete three-dimensional (3D) dataset, (ii) improved image formation through the use of custom telecentric optics, which ensures accurate projection images and minimizes artifacts from scattered and stray-light sources, and (iii) high resolution (potentially 50 microm) isotropic 3D dose readout. The performance of the CCD scanner for 3D dose readout was evaluated by comparison with independent 3D readout from the single laser beam OCTOPUS-scanner for the same PRESAGE dosimeters. The OCTOPUS scanner was considered the "gold standard" technique in light of prior studies demonstrating its accuracy. Additional comparisons were made against calculated dose distributions from the ECLIPSE treatment-planning system. Dose readout for the following treatments were investigated: (i) a single rectangular beam irradiation to investigate small field and very steep dose gradient dosimetry away from edge effects, (ii) a 2-field open beam parallel-opposed irradiation to investigate dosimetry along steep dose gradients, and (iii) a 7-field intensity modulated radiation therapy (IMRT) irradiation to investigate dosimetry for complex treatment delivery involving modulation of fluence and for dosimetry along moderate dose gradients. Dose profiles, dose-difference plots, and gamma maps were employed to evaluate quantitative estimates of agreement between independently measured and calculated dose distributions. Results indicated that dose readout from the CCD scanner was in agreement with independent gold-standard readout from the OCTOPUS-scanner as well as the calculated ECLIPSE dose distribution for all treatments, except in regions within a few

  20. A prototype fan-beam optical CT scanner for 3D dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Warren G.; Rudko, D. A.; Braam, Nicolas A.; Jirasek, Andrew [University of Victoria, Victoria, British Columbia V8P 5C2 (Canada); Wells, Derek M. [British Columbia Cancer Agency, Vancouver Island Centre, Victoria, British Columbia V8R 6V5 (Canada)

    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

  1. Laser-based satellite communication systems stabilized by non-mechanical electro-optic scanners

    Science.gov (United States)

    Ziemkiewicz, Michael; Davis, Scott R.; Rommel, Scott D.; Gann, Derek; Luey, Benjamin; Gamble, Joseph D.; Anderson, Mike

    2016-05-01

    Laser communications systems provide numerous advantages for establishing satellite-to-ground data links. As a carrier for information, lasers are characterized by high bandwidth and directionality, allowing for fast and secure transfer of data. These systems are also highly resistant to RF influences since they operate in the infrared portion of the electromagnetic spectrum, far from radio bands. In this paper we will discuss an entirely non-mechanical electro-optic (EO) laser beam steering technology, with no moving parts, which we have used to form robust 400 Mbps optical data connections through air. This technology will enable low cost, compact, and rugged free space optical (FSO) communication modules for small satellite applications. The EO beam-steerer at the heart of this system is used to maintain beam pointing as the satellite orbits. It is characterized by extremely low values for size, weight and power consumption (SWaP) - approximately 300 cm3, 300 g, and 5 W respectively, which represents a marked improvement compared to heavy, and power-consuming gimbal mechanisms. It is capable of steering a 500 mW, 1 mm short wave infrared (SWIR) beam over a field of view (FOV) of up to 50° x 15°, a range which can be increased by adding polarization gratings, which provide a coarse adjust stage at the EO beam scanner output. We have integrated this device into a communication system and demonstrated the capability to lock on and transmit a high quality data stream by modulation of SWIR power.

  2. Optimization of a fast optical CT scanner for nPAG gel dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Vandecasteele, Jan; De Deene, Yves [Research group QMRI, Department for experimental cancer research, nuclear medicine and radiotherpy (ECNURAD), Ghent University Hospital, De Pintelaan 185, 9000 Gent (Belgium)], E-mail: Jan.Vandecasteele@ugent.be

    2009-05-01

    A fast laser scanning optical CT scanner was constructed and optimized at the Ghent university. The first images acquired were contaminated with several imaging artifacts. The origins of the artifacts were investigated. Performance characteristics of different components were measured such as the laser spot size, light attenuation by the lenses and the dynamic range of the photo-detector. The need for a differential measurement using a second photo-detector was investigated. Post processing strategies to compensate for hardware related errors were developed. Drift of the laser and of the detector was negligible. Incorrectly refractive index matching was dealt with by developing an automated matching process. When scratches on the water bath and phantom container are present, these pose a post processing challenge to eliminate the resulting artifacts from the reconstructed images Secondary laser spots due to multiple reflections need to be further investigated. The time delay in the control of the galvanometer and detector was dealt with using black strips that serve as markers of the projection position. Still some residual ringing artifacts are present. Several small volumetric test phantoms were constructed to obtain an overall picture of the accuracy.

  3. Optical CT scanner for in-air readout of gels for external radiation beam 3D dosimetry.

    Science.gov (United States)

    Ramm, Daniel; Rutten, Thomas P; Shepherd, Justin; Bezak, Eva

    2012-06-21

    Optical CT scanners for a 3D readout of externally irradiated radiosensitive hydrogels currently require the use of a refractive index (RI) matching liquid bath to obtain suitable optical ray paths through the gel sample to the detector. The requirement for a RI matching liquid bath has been negated by the design of a plastic cylindrical gel container that provides parallel beam geometry through the gel sample for the majority of the projection. The design method can be used for various hydrogels. Preliminary test results for the prototype laser beam scanner with ferrous xylenol-orange gel show geometric distortion of 0.2 mm maximum, spatial resolution limited to beam spot size of about 0.4 mm and 0.8% noise (1 SD) for a uniform irradiation. Reconstruction of a star pattern irradiated through the cylinder walls demonstrates the suitability for external beam applications. The extremely simple and cost-effective construction of this optical CT scanner, together with the simplicity of scanning gel samples without RI matching fluid increases the feasibility of using 3D gel dosimetry for clinical external beam dose verifications.

  4. Effect of light source instability on uniformity of 3D reconstructions from a cone beam optical CT scanner.

    Science.gov (United States)

    Begg, J; Taylor, M L; Holloway, L; Kron, T; Franich, R D

    2014-12-01

    Temporally varying light intensity during acquisition of projection images in an optical CT scanner can potentially be misinterpreted as physical properties of the sample. This work investigated the impact of LED light source intensity instability on measured attenuation coefficients. Different scenarios were investigated by conducting one or both of the reference and data scans in a 'cold' scanner, where the light source intensity had not yet stabilised. Uniform samples were scanned to assess the impact on measured uniformity. The orange (590 nm) light source decreased in intensity by 29 % over the first 2 h, while the red (633 nm) decreased by 9 %. The rates of change of intensity at 2 h were 0.1 and 0.03 % respectively over a 5 min period-corresponding to the scan duration. The normalisation function of the reconstruction software does not fully account for the intensity differences and discrepancies remain. Attenuation coefficient inaccuracies of up to 8 % were observed for data reconstructed from projection images acquired with a cold scanner. Increased noise was observed for most cases where one or both of the scans was acquired without sufficient warm-up. The decrease in accuracy and increase in noise were most apparent for data reconstructed from reference and data scans acquired with a cold scanner on different days.

  5. Microarray Scanner for Fluorescence Detection

    Institute of Scientific and Technical Information of China (English)

    Wang Liqiang; Lu zukang; Li Yingsheng; Zheng Xufeng

    2003-01-01

    A novel pseudo confocal microarray scanner is introduced, in which one dimension scanning is performed by a galvanometer optical scanner and a telecentric objective, another dimension scanning is performed by a stepping motor.

  6. Using flatbed scanners in the undergraduate optics laboratory—An example of frugal science

    Science.gov (United States)

    Koopman, Thomas; Gopal, Venkatesh

    2017-05-01

    We describe the use of a low-cost commercial flatbed scanner in the undergraduate teaching laboratory to image large (˜25 cm) interference and diffraction patterns in two dimensions. Such scanners usually have an 8-bit linear photosensor array that can scan large areas (˜28 cm × 22 cm) at very high spatial resolutions (≥100 Megapixels), which makes them versatile large-format imaging devices. We describe how the scanner can be used to image interference and diffraction from rectangular single-slit, double-slit, and circular apertures. The experiments are very simple to setup and require no specialized components besides a small laser and a flatbed scanner. Due to the presence of Automatic Gain Control in the scanner, which we were not able to override, we were unable to get an excellent fit to the data. Interestingly, we found that the less-than-ideal data were actually pedagogically superior as it forced the students to think about the process of data acquisition in much greater detail instead of simply performing the experiment mechanically.

  7. Quantitative wound healing studies using a portable, low cost, handheld near-infrared optical scanner: preliminary sensitivity and specificity analysis

    Science.gov (United States)

    Lei, Jiali; Rodriguez, Suset; Jayachandran, Maanasa; Solis, Elizabeth; Gonzalez, Stephanie; Perez-Clavijo, Francesco; Wigley, Stephen; Godavarty, Anuradha

    2016-03-01

    Lower extremity ulcers are devastating complications that are still un-recognized. To date, clinicians employ visual inspection of the wound site during its standard 4-week of healing process via monitoring of surface granulation. A novel ultra-portable near-infrared optical scanner (NIROS) has been developed at the Optical Imaging Laboratory that can perform non-contact 2D area imaging of the wound site. From preliminary studies it was observed that the nonhealing wounds had a greater absorption contrast with respect to the normal site, unlike in the healing wounds. Currently, non-contact near-infrared (NIR) imaging studies were carried out on 22 lower extremity wounds at two podiatric clinics, and the sensitivity and specificity of the scanner evaluated. A quantitative optical biometric was developed that differentiates healing from non-healing wounds, based on the threshold values obtained during ROC analysis. In addition, optical images of the wound obtained from weekly imaging studies are also assessed to determine the ability of the device to predict wound healing consistently on a periodic basis. This can potentially impact early intervention in the treatment of lower extremity ulcers when an objective and quantitative wound healing approach is developed. Lastly, the incorporation of MATLAB graphical user interface (GUI) to automate the process of image acquisition, image processing and image analysis realizes the potential of NIROS to perform non-contact and real-time imaging on lower extremity wounds.

  8. A spatio-temporally compensated acousto-optic scanner for two-photon microscopy providing large field of view.

    Science.gov (United States)

    Kremer, Y; Léger, J-F; Lapole, R; Honnorat, N; Candela, Y; Dieudonné, S; Bourdieu, L

    2008-07-07

    Acousto-optic deflectors (AOD) are promising ultrafast scanners for non-linear microscopy. Their use has been limited until now by their small scanning range and by the spatial and temporal dispersions of the laser beam going through the deflectors. We show that the use of AOD of large aperture (13mm) compared to standard deflectors allows accessing much larger field of view while minimizing spatio-temporal distortions. An acousto-optic modulator (AOM) placed at distance of the AOD is used to compensate spatial and temporal dispersions. Fine tuning of the AOM-AOD setup using a frequency-resolved optical gating (GRENOUILLE) allows elimination of pulse front tilt whereas spatial chirp is minimized thanks to the large aperture AOD.

  9. The Traveling Optical Scanner – Case Study on 3D Shape Models of Ancient Brazilian Skulls

    DEFF Research Database (Denmark)

    Trinderup, Camilla Himmelstrup; Dahl, Vedrana Andersen; Gregersen, Kristian Murphy

    2016-01-01

    morphological modelling is possible with accurate description of the specimens provided by the models. Furthermore, performing studies on models reduces the risk of damage to the original specimen. In our work we employ a high resolution structured light scanner for digitalizing a collection of 8500 year old...

  10. Dental wear estimation using a digital intra-oral optical scanner and an automated 3D computer vision method.

    Science.gov (United States)

    Meireles, Agnes Batista; Vieira, Antonio Wilson; Corpas, Livia; Vandenberghe, Bart; Bastos, Flavia Souza; Lambrechts, Paul; Campos, Mario Montenegro; Las Casas, Estevam Barbosa de

    2016-01-01

    The objective of this work was to propose an automated and direct process to grade tooth wear intra-orally. Eight extracted teeth were etched with acid for different times to produce wear and scanned with an intra-oral optical scanner. Computer vision algorithms were used for alignment and comparison among models. Wear volume was estimated and visual scoring was achieved to determine reliability. Results demonstrated that it is possible to directly detect submillimeter differences in teeth surfaces with an automated method with results similar to those obtained by direct visual inspection. The investigated method proved to be reliable for comparison of measurements over time.

  11. Total body irradiation with a compensator fabricated using a 3D optical scanner and a 3D printer

    Science.gov (United States)

    Park, So-Yeon; Kim, Jung-in; Joo, Yoon Ha; Lee, Jung Chan; Park, Jong Min

    2017-05-01

    We propose bilateral total body irradiation (TBI) utilizing a 3D printer and a 3D optical scanner. We acquired surface information of an anthropomorphic phantom with the 3D scanner and fabricated the 3D compensator with the 3D printer, which could continuously compensate for the lateral missing tissue of an entire body from the beam’s eye view. To test the system’s performance, we measured doses with optically stimulated luminescent dosimeters (OSLDs) as well as EBT3 films with the anthropomorphic phantom during TBI without a compensator, conventional bilateral TBI, and TBI with the 3D compensator (3D TBI). The 3D TBI showed the most uniform dose delivery to the phantom. From the OSLD measurements of the 3D TBI, the deviations between the measured doses and the prescription dose ranged from  -6.7% to 2.4% inside the phantom and from  -2.3% to 0.6% on the phantom’s surface. From the EBT3 film measurements, the prescription dose could be delivered to the entire body of the phantom within  ±10% accuracy, except for the chest region, where tissue heterogeneity is extreme. The 3D TBI doses were much more uniform than those of the other irradiation techniques, especially in the anterior-to-posterior direction. The 3D TBI was advantageous, owing to its uniform dose delivery as well as its efficient treatment procedure.

  12. Total body irradiation with a compensator fabricated using a 3D optical scanner and a 3D printer.

    Science.gov (United States)

    Park, So-Yeon; Kim, Jung-In; Joo, Yoon Ha; Lee, Jung Chan; Park, Jong Min

    2017-05-07

    We propose bilateral total body irradiation (TBI) utilizing a 3D printer and a 3D optical scanner. We acquired surface information of an anthropomorphic phantom with the 3D scanner and fabricated the 3D compensator with the 3D printer, which could continuously compensate for the lateral missing tissue of an entire body from the beam's eye view. To test the system's performance, we measured doses with optically stimulated luminescent dosimeters (OSLDs) as well as EBT3 films with the anthropomorphic phantom during TBI without a compensator, conventional bilateral TBI, and TBI with the 3D compensator (3D TBI). The 3D TBI showed the most uniform dose delivery to the phantom. From the OSLD measurements of the 3D TBI, the deviations between the measured doses and the prescription dose ranged from  -6.7% to 2.4% inside the phantom and from  -2.3% to 0.6% on the phantom's surface. From the EBT3 film measurements, the prescription dose could be delivered to the entire body of the phantom within  ±10% accuracy, except for the chest region, where tissue heterogeneity is extreme. The 3D TBI doses were much more uniform than those of the other irradiation techniques, especially in the anterior-to-posterior direction. The 3D TBI was advantageous, owing to its uniform dose delivery as well as its efficient treatment procedure.

  13. Design and implementation of a torque-enhancement 2-axis magnetostatic SOI optical scanner

    Science.gov (United States)

    Tang, Tsung-Lin; Hsu, Chia-Pao; Chen, Wen-Chien; Fang, Weileun

    2010-02-01

    This study demonstrates the torque-enhancement design for a 2-axis magnetostatic SOI scanner driven by a double-side electroplating ferromagnetic film. The present design has two merits: (1) the slender ferromagnetic material patterns with higher length-to-width ratio enhance the magnetization, (2) the backside electroplating of the ferromagnetic film increases the volume of the ferromagnetic materials. This study also establishes the fabrication processes to implement the proposed design. The processes also have two merits: (1) the handle-layer of the SOI wafer is exploited as the shadow mask to pattern the seed-layer at the backside of the device layer, (2) the device layer of the SOI wafer acts as the cathode to enable simultaneous double-side electroplating. In applications, a 2-axis SOI scanner was implemented and characterized. Measurements show a 149% torque enhancement from the double-side electroplating design. The vertical slender ferromagnetic material patterns further increase the magnetostatic torque to 211%. This study also successfully demonstrates the Lissajous scanning using the presented 2-axis SOI scanner.

  14. A multi-view time-domain non-contact diffuse optical tomography scanner with dual wavelength detection for intrinsic and fluorescence small animal imaging.

    Science.gov (United States)

    Lapointe, Eric; Pichette, Julien; Bérubé-Lauzière, Yves

    2012-06-01

    We present a non-contact diffuse optical tomography (DOT) scanner with multi-view detection (over 360°) for localizing fluorescent markers in scattering and absorbing media, in particular small animals. It relies on time-domain detection after short pulse laser excitation. Ultrafast time-correlated single photon counting and photomultiplier tubes are used for time-domain measurements. For light collection, seven free-space optics non-contact dual wavelength detection channels comprising 14 detectors overall are placed around the subject, allowing the measurement of time point-spread functions at both excitation and fluorescence wavelengths. The scanner is endowed with a stereo camera pair for measuring the outer shape of the subject in 3D. Surface and DOT measurements are acquired simultaneously with the same laser beam. The hardware and software architecture of the scanner are discussed. Phantoms are used to validate the instrument. Results on the localization of fluorescent point-like inclusions immersed in a scattering and absorbing object are presented. The localization algorithm relies on distance ranging based on the measurement of early photons arrival times at different positions around the subject. This requires exquisite timing accuracy from the scanner. Further exploiting this capability, we show results on the effect of a scattering hetereogenity on the arrival time of early photons. These results demonstrate that our scanner provides all that is necessary for reconstructing images of small animals using full tomographic reconstruction algorithms, which will be the next step. Through its free-space optics design and the short pulse laser used, our scanner shows unprecedented timing resolution compared to other multi-view time-domain scanners.

  15. Note: Optical and electronic design of an amplitude-modulated continuous-wave laser scanner for high-accuracy distance measurement.

    Science.gov (United States)

    Jang, Junhwan; Hwang, Sungui; Park, Kyihwan

    2015-04-01

    To utilize a time-of-flight-based laser scanner as a distance measurement sensor, the measurable distance and accuracy are the most important performance parameters to consider. For these purposes, the optical system and electronic signal processing of the laser scanner should be optimally designed in order to reduce a distance error caused by the optical crosstalk and wide dynamic range input. Optical system design for removing optical crosstalk problem is proposed in this work. Intensity control is also considered to solve the problem of a phase-shift variation in the signal processing circuit caused by object reflectivity. The experimental results for optical system and signal processing design are performed using 3D measurements.

  16. Note: Optical and electronic design of an amplitude-modulated continuous-wave laser scanner for high-accuracy distance measurement

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Junhwan; Hwang, Sungui; Park, Kyihwan, E-mail: khpark@gist.ac.kr [School of Mechatronics, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju (Korea, Republic of)

    2015-04-15

    To utilize a time-of-flight-based laser scanner as a distance measurement sensor, the measurable distance and accuracy are the most important performance parameters to consider. For these purposes, the optical system and electronic signal processing of the laser scanner should be optimally designed in order to reduce a distance error caused by the optical crosstalk and wide dynamic range input. Optical system design for removing optical crosstalk problem is proposed in this work. Intensity control is also considered to solve the problem of a phase-shift variation in the signal processing circuit caused by object reflectivity. The experimental results for optical system and signal processing design are performed using 3D measurements.

  17. Duplication of complete dentures using general-purpose handheld optical scanner and 3-dimensional printer: Introduction and clinical considerations.

    Science.gov (United States)

    Kurahashi, Kosuke; Matsuda, Takashi; Goto, Takaharu; Ishida, Yuichi; Ito, Teruaki; Ichikawa, Tetsuo

    2017-01-01

    To introduce a new clinical procedure for fabricating duplicates of complete dentures by bite pressure impression using digital technology, and to discuss its clinical significance. The denture is placed on a rotary table and the 3-dimensional form of the denture is digitized using a general-purpose handheld optical scanner. The duplicate denture is made of polylactic acid by a 3-dimensional printer using the 3-dimensional data. This procedure has the advantages of wasting less material, employing less human power, decreasing treatment time at the chair side, lowering the rates of contamination, and being readily fabricated at the time of the treatment visit. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  18. Security enhancement of hand geometry scanners using optical blood flow detection

    Science.gov (United States)

    Crihalmeanu, Musat C.; Jerabek, Mark A.; Meehan, Kathleen

    2004-08-01

    In today's security conscious society the efficiency of biometric systems has an increasing tendency to replace the classic but less effective keys and passwords. Hand geometry readers are popular biometrics used for acces control and time and attendance applications. One of their weaknesses is vulnerability to spoofing using fake hands (latex, play-doh or dead-hands). The object of this paper is to design a feature to be added to the hand geometry scanner in order to detect vitality in the hand, reducing the possibilities for spoofing. This paper demonstrates how the hand reader was successfully spoofed and shows the implementation of the vitality detection feature through an inexpensive but efficient electronic design. The method used for detection is photo-plethysmography. The Reflectance Sensor built is of original conception. After amplifying, filtering and processing the sensor's signal, a message is shown via an LCD display, concerning the liveness of the hand and the pulse rate.

  19. Biochip scanner device

    Energy Technology Data Exchange (ETDEWEB)

    Perov, Alexander (Troitsk, RU); Belgovskiy, Alexander I. (Mayfield Heights, OH); Mirzabekov, Andrei D. (Darien, IL)

    2001-01-01

    A biochip scanner device used to detect and acquire fluorescence signal data from biological microchips or biochips and method of use are provided. The biochip scanner device includes a laser for emitting a laser beam. A modulator, such as an optical chopper modulates the laser beam. A scanning head receives the modulated laser beam and a scanning mechanics coupled to the scanning head moves the scanning head relative to the biochip. An optical fiber delivers the modulated laser beam to the scanning head. The scanning head collects the fluorescence light from the biochip, launches it into the same optical fiber, which delivers the fluorescence into a photodetector, such as a photodiode. The biochip scanner device is used in a row scanning method to scan selected rows of the biochip with the laser beam size matching the size of the immobilization site.

  20. Scanner Art

    Science.gov (United States)

    Jaworski, Joy; Murphy, Kris

    2009-01-01

    In this article, the authors describe how they incorporated environmental awareness into their art curriculum. Here, they describe a digital photography project in which their students used flatbed scanners as cameras. Their students composed their objects directly on the scanner. The lesson enabled students to realize that artists have voices…

  1. Remote sensing of atmospheric properties with the Modular Optical Scanner (MOS)

    Science.gov (United States)

    Krawczyk, Harald; Pflug, Bringfried M.; Gerasch, Birgit

    1998-12-01

    Satellite remote sensing of atmospheric properties is important for investigation of atmospheric pollution and also for remote sensing of the underlying surface, where an atmospheric correction is needed. For the proof of new methodological concepts the multispectral imaging spectrometer MOS was developed in the DLR Institute of Space Sensor Technology and launched on the Indian satellite IRS- P3. It has 13 bands in the VIS/NIR region with 10nm bandwidth. MOS successfully provides data for more than 2 years over European and Northern African coasts. The paper will introduce a standard atmospheric correction scheme for MOS data over water regions using measurements in the near IR form 685 nm to 1000 nm. This method is based on a 2- channel correction, estimating the aerosol optical depth and the Angstrom coefficient for the spectral behavior of the optical thickness. After extrapolation of the visible region the atmospheric correction is applied. Examples will be shown from the Baltic and North Sea regions. The obtained result will be compared and discussed with available in situ measurements taken simultaneously with MOS overflights. Lastly, this algorithm is applied to an observation of forest fire smoke over Malaysia.

  2. Design and construction of an optical computed tomography scanner for polymer gel dosimetry application.

    Science.gov (United States)

    Zakariaee, Seyed Salman; Mesbahi, Asghar; Keshtkar, Ahmad; Azimirad, Vahid

    2014-04-01

    Polymer gel dosimeter is the only accurate three dimensional (3D) dosimeter that can measure the absorbed dose distribution in a perfect 3D setting. Gel dosimetry by using optical computed tomography (OCT) has been promoted by several researches. In the current study, we designed and constructed a prototype OCT system for gel dosimetry. First, the electrical system for optical scanning of the gel container using a Helium-Neon laser and a photocell was designed and constructed. Then, the mechanical part for two rotational and translational motions was designed and step motors were assembled to it. The data coming from photocell was grabbed by the home-built interface and sent to a personal computer. Data processing was carried out using MATLAB software. To calibrate the system and tune up the functionality of it, different objects was designed and scanned. Furthermore, the spatial and contrast resolution of the system was determined. The system was able to scan the gel dosimeter container with a diameter up to 11 cm inside the water phantom. The standard deviation of the pixels within water flask image was considered as the criteria for image uniformity. The uniformity of the system was about ±0.05%. The spatial resolution of the system was approximately 1 mm and contrast resolution was about 0.2%. Our primary results showed that this system is able to obtain two-dimensional, cross-sectional images from polymer gel samples.

  3. Monte Carlo simulation of an x-ray luminescence optical tomography scanner prototype

    Energy Technology Data Exchange (ETDEWEB)

    Rosas-González, S., E-mail: sarahi@fisica.unam.mx, E-mail: arnulfo@fisica.unam.mx; Martínez-Dávalos, A., E-mail: sarahi@fisica.unam.mx, E-mail: arnulfo@fisica.unam.mx; Rodríguez-Villafuerte, M., E-mail: sarahi@fisica.unam.mx, E-mail: arnulfo@fisica.unam.mx; Murrieta-Rodríguez, T., E-mail: sarahi@fisica.unam.mx, E-mail: arnulfo@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, A.P. 20-364, 01000 (Mexico)

    2014-11-07

    In this work we report the calculation of the deposited energy distribution produced by an x-ray luminescence optical tomography (XLOT) system in a phantom containing different concentrations of Gd{sub 2}O{sub 2}S:Eu nanoparticles. The calculations were performed via Monte Carlo simulation considering spectra from a W target x-ray tube operating between 30 and 90 kVp, with 1.0 mm Al added filtration. CT and XLOT tomographic images were reconstructed from the same data. The results show that XLOT has better detectability than CT alone, that the dose scales linearly with kVp for a fixed concentration of Gd{sub 2}O{sub 2}S:Eu and air-kerma rate, the scattered radiation contribution to the total dose and signal is about 20% and that the dose ratio for a 3 mm diameter insert containing 10 mg/ml Gd{sub 2}O{sub 2}S embedded in a 30 mm diameter water phantom is 6:1. This ratio drops to less than 2:1 for a 1 mg/ml concentration. Finally we show that the method of conjugate images can be used to correct for artifacts due to attenuation effects in XLOT images.

  4. Portable biochip scanner device

    Energy Technology Data Exchange (ETDEWEB)

    Perov, Alexander (Troitsk, RU); Sharonov, Alexei (Moscow, RU); Mirzabekov, Andrei D. (Darien, IL)

    2002-01-01

    A portable biochip scanner device used to detect and acquire fluorescence signal data from biological microchips (biochips) is provided. The portable biochip scanner device employs a laser for emitting an excitation beam. An optical fiber delivers the laser beam to a portable biochip scanner. A lens collimates the laser beam, the collimated laser beam is deflected by a dichroic mirror and focused by an objective lens onto a biochip. The fluorescence light from the biochip is collected and collimated by the objective lens. The fluorescence light is delivered to a photomultiplier tube (PMT) via an emission filter and a focusing lens. The focusing lens focuses the fluorescence light into a pinhole. A signal output of the PMT is processed and displayed.

  5. Boresight calibration of construction misalignments for 3D scanners built with a 2D laser range finder rotating on its optical center.

    Science.gov (United States)

    Morales, Jesús; Martínez, Jorge L; Mandow, Anthony; Reina, Antonio J; Pequeño-Boter, Alejandro; García-Cerezo, Alfonso

    2014-10-24

    Many applications, like mobile robotics, can profit from acquiring dense, wide-ranging and accurate 3D laser data. Off-the-shelf 2D scanners are commonly customized with an extra rotation as a low-cost, lightweight and low-power-demanding solution. Moreover, aligning the extra rotation axis with the optical center allows the 3D device to maintain the same minimum range as the 2D scanner and avoids offsets in computing Cartesian coordinates. The paper proposes a practical procedure to estimate construction misalignments based on a single scan taken from an arbitrary position in an unprepared environment that contains planar surfaces of unknown dimensions. Inherited measurement limitations from low-cost 2D devices prevent the estimation of very small translation misalignments, so the calibration problem reduces to obtaining boresight parameters. The distinctive approach with respect to previous plane-based intrinsic calibration techniques is the iterative maximization of both the flatness and the area of visible planes. Calibration results are presented for a case study. The method is currently being applied as the final stage in the production of a commercial 3D rangefinder.

  6. Modeling of a piezoelectric micro-scanner

    CERN Document Server

    Chaehoi, A; Cornez, D; Kirk, K

    2008-01-01

    Micro-scanners have been widely used in many optical applications. The micro-scanner presented in this paper uses multimorph-type bending actuators to tilt a square plate mirror. This paper presents a complete analytical model of the piezoelectric micro-scanner. This theoretical model based on strength of material equations calculates the force generated by the multimorphs on the mirror, the profile of the structure and the angular deflection of the mirror. The proposed model, used to optimize the design of the piezoelectric silicon micro-scanner, is intended for further HDL integration, allowing in this way system level simulation and optimization.

  7. Micro-optical design of a three-dimensional microlens scanner for vertically integrated micro-opto-electro-mechanical systems.

    Science.gov (United States)

    Baranski, Maciej; Bargiel, Sylwester; Passilly, Nicolas; Gorecki, Christophe; Jia, Chenping; Frömel, Jörg; Wiemer, Maik

    2015-08-01

    This paper presents the optical design of a miniature 3D scanning system, which is fully compatible with the vertical integration technology of micro-opto-electro-mechanical systems (MOEMS). The constraints related to this integration strategy are considered, resulting in a simple three-element micro-optical setup based on an afocal scanning microlens doublet and a focusing microlens, which is tolerant to axial position inaccuracy. The 3D scanning is achieved by axial and lateral displacement of microlenses of the scanning doublet, realized by micro-electro-mechanical systems microactuators (the transmission scanning approach). Optical scanning performance of the system is determined analytically by use of the extended ray transfer matrix method, leading to two different optical configurations, relying either on a ball lens or plano-convex microlenses. The presented system is aimed to be a core component of miniature MOEMS-based optical devices, which require a 3D optical scanning function, e.g., miniature imaging systems (confocal or optical coherence microscopes) or optical tweezers.

  8. How flatbed scanners upset accurate film dosimetry.

    Science.gov (United States)

    van Battum, L J; Huizenga, H; Verdaasdonk, R M; Heukelom, S

    2016-01-21

    Film is an excellent dosimeter for verification of dose distributions due to its high spatial resolution. Irradiated film can be digitized with low-cost, transmission, flatbed scanners. However, a disadvantage is their lateral scan effect (LSE): a scanner readout change over its lateral scan axis. Although anisotropic light scattering was presented as the origin of the LSE, this paper presents an alternative cause. Hereto, LSE for two flatbed scanners (Epson 1680 Expression Pro and Epson 10000XL), and Gafchromic film (EBT, EBT2, EBT3) was investigated, focused on three effects: cross talk, optical path length and polarization. Cross talk was examined using triangular sheets of various optical densities. The optical path length effect was studied using absorptive and reflective neutral density filters with well-defined optical characteristics (OD range 0.2-2.0). Linear polarizer sheets were used to investigate light polarization on the CCD signal in absence and presence of (un)irradiated Gafchromic film. Film dose values ranged between 0.2 to 9 Gy, i.e. an optical density range between 0.25 to 1.1. Measurements were performed in the scanner's transmission mode, with red-green-blue channels. LSE was found to depend on scanner construction and film type. Its magnitude depends on dose: for 9 Gy increasing up to 14% at maximum lateral position. Cross talk was only significant in high contrast regions, up to 2% for very small fields. The optical path length effect introduced by film on the scanner causes 3% for pixels in the extreme lateral position. Light polarization due to film and the scanner's optical mirror system is the main contributor, different in magnitude for the red, green and blue channel. We concluded that any Gafchromic EBT type film scanned with a flatbed scanner will face these optical effects. Accurate dosimetry requires correction of LSE, therefore, determination of the LSE per color channel and dose delivered to the film.

  9. Network Security Scanner

    OpenAIRE

    2011-01-01

    Network Security Scanner (NSS) is a tool that allows auditing and monitoring remote network computers for possible vulnerabilities, checks your network for all potential methods that a hacker might use to attack it. Network Security Scanner is a complete networking utilities package that includes a wide range of tools for network security auditing, vulnerability Auditing, scanning, monitoring and more. Network Security Scanner (NSS) is an easy to use, intuitive network security scanner that c...

  10. A high-field 3He Metastability Exchange Optical Pumping polarizer operating in a 1.5 T medical scanner for lung MRI

    CERN Document Server

    Collier, G; Wojna, A; Głowacz, B; Suchanek, M; Olejniczak, Z; Dohnalik, T

    2013-01-01

    After being hyperpolarized using the technique of Metastability Exchange Optical Pumping (MEOP), 3He can be used as a contrast agent for lung magnetic resonance imaging (MRI). MEOP is usually performed at low magnetic field (~ 1 mT) and low pressure (~ 1 mbar), which results in a low magnetization production rate. A delicate polarization-preserving step of compression is also required. It was demonstrated in sealed cells that high nuclear polarization values can be obtained at higher pressures with MEOP, if performed at high magnetic field (non-standard conditions). In this work the feasibility of building a high-field polarizer that operates within a commercial 1.5 T scanner was evaluated. Preliminary measurements of nuclear polarization with sealed cells filled at different 3He gas pressures (1.33 to 267 mbar) were performed. The use of an annular shape for the laser beam increased by 25 % the achievable nuclear polarization equilibrium value (Meq) at 32 and 67 mbar as compared to a Gaussian beam shape. Meq...

  11. Microscopy system of atomic force based on a digital optical reading unit and a buzzer-scanner; Sistema de microscopia de fuerza atomica basada en una unidad de lectura optica digital y un escaner-zumbador

    Energy Technology Data Exchange (ETDEWEB)

    Dabirian, R.; Loza M, D. [Universidad de las Fuerzas Armadas-ESPE, Departamento de Ciencias de la Energia y Mecanica, Sangolqui (Ecuador); Wang, W. M.; Hwu, E. T., E-mail: whoand@gmail.com [Academia Sinica, Institute of Physics, Taipei, 11529 Taiwan (China)

    2015-07-01

    An astigmatic detection system (Ads) based on a compact disk/digital-versatile-disk (Cd-DVD) astigmatic optical pickup unit is presented. It can achieve a resolution better than 0.3 nm in detection of the vertical displacement and is able to detect the two-dimensional angular tilt of the object surface. Furthermore, a novel scanner design actuated by piezoelectric disk buzzers is presented. The scanner is composed of a quad-rod actuation structure and several piezoelectric disks. It can be driven directly with low-voltage and low-current sources, such as analogue outputs of a data acquisition card and enables a sufficient scanning range of up to μm. In addition, an economic, high-performance streamlined atomic force microscopy (AFM) was constructed, using the buzzer-scanner to move the sample relative to the probe, and using a Cd/DVD optical pickup unit to detect the mechanical resonance of a micro fabricated cantilever. The performance of the AFM is evaluated. The high sensitivity and high bandwidth of the detection system makes the equipment suitable for characterizing nano scale elements. An AFM using our detection system for detecting the deflection of micro fabricated cantilevers can resolve individual atomic steps on graphite surfaces. (Author)

  12. Colorimetric Scanner Characterisation

    Directory of Open Access Journals (Sweden)

    Jon Y. Hardeberg

    2003-12-01

    Full Text Available In this paper, methods for the colorimetric characterisation of colour scanners are proposed and evaluated. These methods apply equally to other colour image input devices such as digital cameras. The goal of our characterisation is to establish the relationship between the device-dependent colour space of the scanner and the device-independent CIELAB colour space. The scanner characterisation is based on polynomial regression techniques. Several regression schemes have been tested. The retained method consists in applying a non-linear correction to the scanner RGB values followed by a 3rd order 3D polynomial regression function directly to CIELAB space. This method gives very good results in terms of residual colour differences. This is partly due to the fact that the RMS error that is minimised in the regression corresponds to ΔE*ab which is well correlated to visual colour differences.

  13. Verification of a CT scanner using a miniature step gauge

    DEFF Research Database (Denmark)

    Cantatore, Angela; Andreasen, J.L.; Carmignato, S.;

    2011-01-01

    The work deals with performance verification of a CT scanner using a 42mm miniature replica step gauge developed for optical scanner verification. Errors quantification and optimization of CT system set-up in terms of resolution and measurement accuracy are fundamental for use of CT scanning...

  14. Twisting wire scanner

    CERN Document Server

    Gharibyan, V; Krouptchenkov, I; Nölle, D; Tiessen, H; Werner, M; Wittenburg, K

    2012-01-01

    A new type of 'two-in-one' wire scanner is proposed. Recent advances in linear motors' technology make it possible to combine translational and rotational movements. This will allow to scan the beam in two perpendicular directions using a single driving motor and a special fork attached to it. Vertical or horizontal mounting will help to escape problems associated with the 45 deg scanners. Test results of the translational part with linear motors is presented.

  15. Cobalt-60 Container Scanner

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    This paper presents a special container scanner in which the radiation source is a conventional radiography 60Co projector of (100-300)×3 .7×1010Bq. With a specia l sensitive array detector, invented by Institute of Nuclear Energy Technology ( INET) of Tsinghua University and other technical innovations, t he characteristics of the 60Co scanner qualify it for use in c ontainer insp ection. Its contrast indicator (CI) and image quality indicator (IQI) for 10 0 mm steel are equal to 0.7% and 2.5%, respectively, and the steel penetration ( SP) is about 240 mm. The 60Co container scanner is much more ec onomical and more reliable than those scanners using an accelerator source. Also, its penetr ation ability is much better than that of an X-ray machine scanner. This paper p resents the system design, the main difficulties and their technical solutions, the inspection characteristics and the special features of the 60Co sc anner.

  16. Rail profile control using laser triangulation scanners

    Science.gov (United States)

    Boronahin, Ð. ńlexandr M.; Larionov, Daniil Yu.; Podgornaya, Liudmila N.; Shalymov, Roman V.; Filatov, Yuri V.; Bokhman, Evgueny D.

    2016-11-01

    Rail track geometric parameters measurement requires knowledge of left and right rail head location in each section. First of all displacement in transverse plane of rail head point located at a distance of 14 mm below the running surface, must be controlled [1]. It is carried out by detecting of each rail profile using triangulation laser scanners. Optical image recognition is carried out successfully in the laboratory, approaches used for this purpose are widely known. However, laser scanners operation has several features on railways leading to necessity of traditional approaches adaptation for solving these particular problems. The most significant problem is images noisiness due to the solar flashes and the effect of "Moon path" on the smooth rail surface. Using of optical filters gives inadequate result, because scanner laser diodes radiation frequency varies with temperature changes that forbid the use of narrow-band filters. Consideration of these features requires additional constructive and algorithmic solutions, including involvement of information from other sensors of the system. The specific usage of optical scanners for rail profiles control is the subject of the paper.

  17. MEMS temperature scanner: principles, advances, and applications

    Science.gov (United States)

    Otto, Thomas; Saupe, Ray; Stock, Volker; Gessner, Thomas

    2010-02-01

    Contactless measurement of temperatures has gained enormous significance in many application fields, ranging from climate protection over quality control to object recognition in public places or military objects. Thereby measurement of linear or spatially temperature distribution is often necessary. For this purposes mostly thermographic cameras or motor driven temperature scanners are used today. Both are relatively expensive and the motor drive devices are limited regarding to the scanning rate additionally. An economic alternative are temperature scanner devices based on micro mirrors. The micro mirror, attached in a simple optical setup, reflects the emitted radiation from the observed heat onto an adapted detector. A line scan of the target object is obtained by periodic deflection of the micro scanner. Planar temperature distribution will be achieved by perpendicularly moving the target object or the scanner device. Using Planck radiation law the temperature of the object is calculated. The device can be adapted to different temperature ranges and resolution by using different detectors - cooled or uncooled - and parameterized scanner parameters. With the basic configuration 40 spatially distributed measuring points can be determined with temperatures in a range from 350°C - 1000°C. The achieved miniaturization of such scanners permits the employment in complex plants with high building density or in direct proximity to the measuring point. The price advantage enables a lot of applications, especially new application in the low-price market segment This paper shows principle, setup and application of a temperature measurement system based on micro scanners working in the near infrared range. Packaging issues and measurement results will be discussed as well.

  18. Confocal Scanner for Vertical Particle Tracks in the Nuclear Photoemulsion

    CERN Document Server

    Soroko, L M

    2005-01-01

    A confocal scanner for selective observation of the vertical particle tracks in the nuclear photoemulsion is described. The particle track being searched for is imaging at an angle of 45$^\\circ$ with respect to the optical axis of the system. The confocal scanner is provided with a new optical element, an "image hogonalizator", by means of which the extended image of the inclined vertical particle track is rotated over an angle of 90$^\\circ$. The stereoscopic version of the confocal scanner is presented as well. The described systems will be used in the experiments for investigation of the neutrino oscillations in the accelerators experiments.

  19. Ionization beam scanner

    CERN Multimedia

    CERN PhotoLab

    1973-01-01

    Inner structure of an ionization beam scanner, a rather intricate piece of apparatus which permits one to measure the density distribution of the proton beam passing through it. On the outside of the tank wall there is the coil for the longitudinal magnetic field, on the inside, one can see the arrangement of electrodes creating a highly homogeneous transverse electric field.

  20. Development of a new laser-line and CCD based optical-CT scanner for the readout of 3D radiation dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Papadakis, A E; Maris, T G; Zacharakis, G; Ripoll, J; Varveris, C; Damilakis, J, E-mail: apapadak@edu.med.uoc.g

    2010-11-01

    We present initial results on the comparison of the dose readout from a three dimensional polymer gel dosimeter using two different optical-CT systems; i) a common wide field and a wide area detector optical-CT system and ii) a new 'laser-line' and wide area detector based optical-CT system. The findings presented herein highlight the advantage of the laser based over the wide field optical-CT concept for the readout of scattering 3D dosimeters. Moreover, the new 'laser-line' based optical-CT system overcomes the disadvantage of the long acquisition times required by the existing laser-based instruments.

  1. Scanner calibration revisited.

    Science.gov (United States)

    Pozhitkov, Alexander E

    2010-07-01

    Calibration of a microarray scanner is critical for accurate interpretation of microarray results. Shi et al. (BMC Bioinformatics, 2005, 6, Art. No. S11 Suppl. 2.) reported usage of a Full Moon BioSystems slide for calibration. Inspired by the Shi et al. work, we have calibrated microarray scanners in our previous research. We were puzzled however, that most of the signal intensities from a biological sample fell below the sensitivity threshold level determined by the calibration slide. This conundrum led us to re-investigate the quality of calibration provided by the Full Moon BioSystems slide as well as the accuracy of the analysis performed by Shi et al. Signal intensities were recorded on three different microarray scanners at various photomultiplier gain levels using the same calibration slide from Full Moon BioSystems. Data analysis was conducted on raw signal intensities without normalization or transformation of any kind. Weighted least-squares method was used to fit the data. We found that initial analysis performed by Shi et al. did not take into account autofluorescence of the Full Moon BioSystems slide, which led to a grossly distorted microarray scanner response. Our analysis revealed that a power-law function, which is explicitly accounting for the slide autofluorescence, perfectly described a relationship between signal intensities and fluorophore quantities. Microarray scanners respond in a much less distorted fashion than was reported by Shi et al. Full Moon BioSystems calibration slides are inadequate for performing calibration. We recommend against using these slides.

  2. Scanner calibration revisited

    Directory of Open Access Journals (Sweden)

    Pozhitkov Alexander E

    2010-07-01

    Full Text Available Abstract Background Calibration of a microarray scanner is critical for accurate interpretation of microarray results. Shi et al. (BMC Bioinformatics, 2005, 6, Art. No. S11 Suppl. 2. reported usage of a Full Moon BioSystems slide for calibration. Inspired by the Shi et al. work, we have calibrated microarray scanners in our previous research. We were puzzled however, that most of the signal intensities from a biological sample fell below the sensitivity threshold level determined by the calibration slide. This conundrum led us to re-investigate the quality of calibration provided by the Full Moon BioSystems slide as well as the accuracy of the analysis performed by Shi et al. Methods Signal intensities were recorded on three different microarray scanners at various photomultiplier gain levels using the same calibration slide from Full Moon BioSystems. Data analysis was conducted on raw signal intensities without normalization or transformation of any kind. Weighted least-squares method was used to fit the data. Results We found that initial analysis performed by Shi et al. did not take into account autofluorescence of the Full Moon BioSystems slide, which led to a grossly distorted microarray scanner response. Our analysis revealed that a power-law function, which is explicitly accounting for the slide autofluorescence, perfectly described a relationship between signal intensities and fluorophore quantities. Conclusions Microarray scanners respond in a much less distorted fashion than was reported by Shi et al. Full Moon BioSystems calibration slides are inadequate for performing calibration. We recommend against using these slides.

  3. Use of an optical digital reader for establishing criterion of quality control in clinical beams; Uso de un lector optico digital (scanner) para establecer criterios de control de calidad en haces clinicos

    Energy Technology Data Exchange (ETDEWEB)

    Genis S, R. [Unidad de Radioterapia, Hospital Medica Sur, S.A. Pte. de Piedra 150, Col. Toriello Guerra, 14050 Mexico D.F. (Mexico)

    1998-12-31

    The goal of this work is to present a procedure for realizing the control of the clinical radiation fields through typical radiographic film of verification in radiotherapy and showing the results of the analysis carried out in the expositions of reference fields for photons and electrons using an optical digital reader of high resolution (600 x 1200 dpi) named scanner and a computer program for images edition. It was possible to obtain the quantification of the following parameters: alinement of the radiation beam with the luminous beam, homogeneity or levelling of the radiation field, and self symmetry with respect to the center of the luminous field. With the purpose to compare the results versus an usual method it was realized measurements of the same images with a luminous photo densitometer with 1 mm collimation window. (Author)

  4. A volume scanner for diffuse imaging

    Science.gov (United States)

    Vafa, Elham; Roberts, Nicolas; Sharafutdinova, Galiya; Holdsworth, John

    2016-11-01

    Non-invasive optical screening mammography has a significant barrier in the extreme scatter of human tissue at optical wavelengths. A volume scanner suited for high numerical aperture capture of scattered light from diffuse media has been designed, modelled using Trace Pro software and experimentally constructed. Modelling results indicate the presence of an embedded volume with different scatter properties from the bulk yields a measurable difference in the overall scatter pattern and intensity recorded. Work towards a full tomographic reconstruction from scattered light recorded on the two dimensional array detector is currently underway.

  5. A new fiber-optic non-contact compact laser-ultrasound scanner for fast non-destructive testing and evaluation of aircraft composites.

    Science.gov (United States)

    Pelivanov, Ivan; Buma, Takashi; Xia, Jinjun; Wei, Chen-Wei; O'Donnell, Matthew

    2014-03-21

    Laser ultrasonic (LU) inspection represents an attractive, non-contact method to evaluate composite materials. Current non-contact systems, however, have relatively low sensitivity compared to contact piezoelectric detection. They are also difficult to adjust, very expensive, and strongly influenced by environmental noise. Here, we demonstrate that most of these drawbacks can be eliminated by combining a new generation of compact, inexpensive fiber lasers with new developments in fiber telecommunication optics and an optimally designed balanced probe scheme. In particular, a new type of a balanced fiber-optic Sagnac interferometer is presented as part of an all-optical LU pump-probe system for non-destructive testing and evaluation of aircraft composites. The performance of the LU system is demonstrated on a composite sample with known defects. Wide-band ultrasound probe signals are generated directly at the sample surface with a pulsed fiber laser delivering nanosecond laser pulses at a repetition rate up to 76 kHz rate with a pulse energy of 0.6 mJ. A balanced fiber-optic Sagnac interferometer is employed to detect pressure signals at the same point on the composite surface. A- and B-scans obtained with the Sagnac interferometer are compared to those made with a contact wide-band polyvinylidene fluoride transducer.

  6. A Cost Effective Multi-Spectral Scanner for Natural Gas Detection

    Energy Technology Data Exchange (ETDEWEB)

    Yudaya Sivathanu; Jongmook Lim; Vinoo Narayanan; Seonghyeon Park

    2005-12-07

    The objective of this project is to design, fabricate and demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at EnUrga Inc. The multi-spectral scanner was also evaluated using a blind Department of Energy study at the Rocky Mountain Oilfield Testing Center. The performance of the scanner was inconsistent during the blind study. However, most of the leaks were outside the view of the multi-spectral scanner that was developed during the first year of the project. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner. During the second year, the optical design of the scanner was changed to improve the sensitivity of the system. Laboratory tests show that the system can reliably detect small leaks (20 SCFH) at 30 to 50 feet. A prototype scanner was built and evaluated during the second year of the project. Only laboratory evaluations were completed during the second year. The laboratory evaluations show the feasibility of using the scanner to determine natural gas pipeline leaks. Further field evaluations and optimization of the scanner are required before commercialization of the scanner can be initiated.

  7. APLIKASI INFO HALAL MENGGUNAKAN BARCODE SCANNER UNTUK SMARTPHONE ANDROID

    Directory of Open Access Journals (Sweden)

    Beki Subeki

    2016-05-01

    Full Text Available Abstract – In the production and trade of food products in the era of globalization, people are consuming, especially Muslims need to be given the knowledge, information and access to adequate in order to obtain the correct information about the halal status of products bought. The use of barcode scanners halal product information using the mobile platform is effective and useful for the public to find out information on a product. Barcode scanners can be read by optical scanners called barcode readers or scanned from an image by special software. In Indonesia, most mobile phones have the scanning software for 2D codes, and similar devices available via smartphone.   Keywords : Barcode Scanner, Mobile Platform, Halal Products, Smartphone     Abstrak - Dalam kegiatan produksi dan perdagangan produk pangan di era globalisasi ini, masyarakat yang mengkonsumsi, khususnya umat islam perlu diberikan pengetahuan tentang kehalalan produk, informasi dan akses yang memadai agar memperoleh informasi yang benar tentang status kehalalan produk yang dibelinya. Penggunaan barcode scanner informasi produk halal dengan menggunakan mobile platform dinilai cukup efektif dan berguna bagi masyarakat luas untuk mengetahui informasi sebuah produk. Barcode scanner dapat dibaca oleh pemindai optik yang disebut pembaca kode batang atau dipindai dari sebuah gambar oleh perangkat lunak khusus. Di Indonesia, kebanyakan telepon genggam memiliki perangkat lunak pemindai untuk kode 2D, dan perangkat sejenis tersedia melalui smartphone.   Kata Kunci: Barcode Scanner, Mobile Platform, Produk Halal, Smartphone

  8. Effects of sitting versus standing and scanner type on cashiers.

    Science.gov (United States)

    Lehman, K R; Psihogios, J P; Meulenbroek, R G

    2001-06-10

    In the retail supermarket industry where cashiers perform repetitive, light manual material-handling tasks when scanning and handling products, reports of musculoskeletal disorders and discomfort are high. Ergonomics tradeoffs exist between sitting and standing postures, which are further confounded by the checkstand design and point-of-sale technology, such as the scanner. A laboratory experiment study was conducted to understand the effects of working position (sitting versus standing) and scanner type (bi-optic versus single window) on muscle activity, upper limb and spinal posture, and subjective preference of cashiers. Ten cashiers from a Dutch retailer participated in the study. Cashiers exhibited lower muscle activity in the neck and shoulders when standing and using a bi-optic scanner. Shoulder abduction was also less for standing conditions. In addition, all cashiers preferred using the bi-optic scanner with mixed preferences for sitting (n = 6) and standing (n = 4). Static loading of the muscles was relatively high compared with benchmarks, suggesting that during the task of scanning, cashiers may not have adequate recovery time to prevent fatigue. It is recommended that retailers integrate bi-optic scanners into standing checkstands to minimize postural stress, fatigue and discomfort in cashiers.

  9. Laser Scanner Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Fuss, B.

    2005-09-06

    In the Summer of 2004 a request for proposals went out to potential vendors to offer a three-dimensional laser scanner for a number of unique metrology tasks at the Stanford Linear Accelerator Center (SLAC). Specifications were established including range, accuracy, scan density, resolution and field of view in consideration of anticipated department requirements. Four vendors visited the site to present their system and they were asked to perform three unique tests with their system on a two day visit to SLAC. Two of the three tests were created to emulate real-world applications at SLAC while the third was an accuracy and resolution series of experiments. The scope of these tests is presented and some of the vendor's results are included.

  10. BEPC II wire scanner system

    Institute of Scientific and Technical Information of China (English)

    SUI Yan-Feng; WANG Lin; ZHAO Ying; YUE Jun-Hui; LI Xiao-Ping; CAO Jian-She; MA Li

    2010-01-01

    To monitor the beam profile at the end of the linac non-destructively,a wire scanner as a new diagnostic instrument was designed,manufactured and installed in 2007.Since then,several measurements have been carried out using this device.This paper describes the whole system of the wire scanner and the testing results.

  11. Pure Nano-Rotation Scanner

    Directory of Open Access Journals (Sweden)

    Moo-Yeon Lee

    2012-01-01

    Full Text Available We developed and tested a novel rotation scanner for nano resolution and accurate rotary motion about the rotation center. The scanner consists of circular hinges and leaf springs so that the parasitic error at the center of the scanner in the X and Y directions is minimized, and rotation performance is optimized. Each sector of the scanner's system was devised to have nano resolution by minimizing the parasitic errors of the rotation center that arise due to displacements other than rotation. The analytic optimal design results of the proposed scanner were verified using finite element analyses. The piezoelectric actuators were used to attain nano-resolution performances, and a capacitive sensor was used to measure displacement. A feedback controller was used to minimize the rotation errors in the rotation scanner system under practical conditions. Finally, the performance evaluation test results showed that the resonance frequency was 542 Hz, the resolution was 0.09 μrad, and the rotation displacement was 497.2 μrad. Our test results revealed that the rotation scanner exhibited accurate rotation about the center of the scanner and had good nano precision.

  12. A near-infrared confocal scanner

    Science.gov (United States)

    Lee, Seungwoo; Yoo, Hongki

    2014-06-01

    In the semiconductor industry, manufacturing of three-dimensional (3D) packages or 3D integrated circuits is a high-performance technique that requires combining several functions in a small volume. Through-silicon vias, which are vertical electrical connections extending through a wafer, can be used to direct signals between stacked chips, thus increasing areal density by stacking and connecting multiple patterned chips. While defect detection is essential in the semiconductor manufacturing process, it is difficult to identify defects within a wafer or to monitor the bonding results between bonded surfaces because silicon and many other semiconductor materials are opaque to visible wavelengths. In this context, near-infrared (NIR) imaging is a promising non-destructive method to detect defects within silicon chips, to inspect bonding between chips and to monitor the chip alignment since NIR transmits through silicon. In addition, a confocal scanner provides high-contrast, optically-sectioned images of the specimen due to its ability to reject out-of-focus noise. In this study, we report an NIR confocal scanner that rapidly acquires high-resolution images with a large field of view through silicon. Two orthogonal line-scanning images can be acquired without rotating the system or the specimen by utilizing two orthogonally configured resonant scanning mirrors. This NIR confocal scanner can be efficiently used as an in-line inspection system when manufacturing semiconductor devices by rapidly detecting defects on and beneath the surface.

  13. Intraoral 3D scanner

    Science.gov (United States)

    Kühmstedt, Peter; Bräuer-Burchardt, Christian; Munkelt, Christoph; Heinze, Matthias; Palme, Martin; Schmidt, Ingo; Hintersehr, Josef; Notni, Gunther

    2007-09-01

    Here a new set-up of a 3D-scanning system for CAD/CAM in dental industry is proposed. The system is designed for direct scanning of the dental preparations within the mouth. The measuring process is based on phase correlation technique in combination with fast fringe projection in a stereo arrangement. The novelty in the approach is characterized by the following features: A phase correlation between the phase values of the images of two cameras is used for the co-ordinate calculation. This works contrary to the usage of only phase values (phasogrammetry) or classical triangulation (phase values and camera image co-ordinate values) for the determination of the co-ordinates. The main advantage of the method is that the absolute value of the phase at each point does not directly determine the coordinate. Thus errors in the determination of the co-ordinates are prevented. Furthermore, using the epipolar geometry of the stereo-like arrangement the phase unwrapping problem of fringe analysis can be solved. The endoscope like measurement system contains one projection and two camera channels for illumination and observation of the object, respectively. The new system has a measurement field of nearly 25mm × 15mm. The user can measure two or three teeth at one time. So the system can by used for scanning of single tooth up to bridges preparations. In the paper the first realization of the intraoral scanner is described.

  14. Nogle muligheder i scanner data

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn

    2000-01-01

    I artiklen gives en diskussion af en række af de muligheder for effektivisering af marketingaktiviteter, der er til stede for såvel mærkevareudbyder som detaillist, ved udnyttelse af information fra scanner data......I artiklen gives en diskussion af en række af de muligheder for effektivisering af marketingaktiviteter, der er til stede for såvel mærkevareudbyder som detaillist, ved udnyttelse af information fra scanner data...

  15. Phosphor Scanner For Imaging X-Ray Diffraction

    Science.gov (United States)

    Carter, Daniel C.; Hecht, Diana L.; Witherow, William K.

    1992-01-01

    Improved optoelectronic scanning apparatus generates digitized image of x-ray image recorded in phosphor. Scanning fiber-optic probe supplies laser light stimulating luminescence in areas of phosphor exposed to x rays. Luminescence passes through probe and fiber to integrating sphere and photomultiplier. Sensitivity and resolution exceed previously available scanners. Intended for use in x-ray crystallography, medical radiography, and molecular biology.

  16. Quantification of leaf greenness and leaf spectral profile in plant diagnosis using an optical scanner Quantificação do nível de verde e padrão espectral foliar no diagnóstico de plantas através de um scanner ótico

    Directory of Open Access Journals (Sweden)

    Ryoichi Doi

    2012-06-01

    Full Text Available Observation of leaf spectral profile (color enables suitable management measures to be taken for crop production. An optical scanner was used: 1 to obtain an equation to determine the greenness of plant leaves and 2 to examine the power to discriminate among plants grown under different nutritional conditions. Sweet basil seedlings grown on vermiculite were supplemented with one-fifth-strength Hoagland solutions containing 0, 0.2, 1, 5, 20, and 50 mM NH4+. The 5 mM treatment resulted in the greatest leaf and shoot weights, indicating a quadratic growth response pattern to the NH4+ gradient. An equation involving b*, black and green to describe the greenness of leaves was provided by the spectral profiling of a color scale for rice leaves as the standard. The color scale values for the basil leaves subjected to 0.2 and 1 mM NH4+ treatments were 1.00 and 1.12, respectively. The other treatments resulted in significantly greater values of 2.25 to 2.42, again indicating a quadratic response pattern. Based on the spectral data set consisting of variables of red-green-blue and other color models and color scale values, in discriminant analysis, 81% of the plants were correctly classified into the six NH4+ treatment groups. Combining the spectral data set with the growth data set consisting of leaf and shoot weights, 92% of the plant samples were correctly classified whereas, using the growth data set, only 53% of plants were correctly classified. Therefore, the optical scanning of leaves and the use of spectral profiles helped plant diagnosis when biomass measurements were not effective.A observação do perfil espectral da folha (cor permite medidas de gestão adequadas a serem consideradas na produção. Um scanner óptico foi usado para: 1 obter uma equação para determinar o verde das folhas e 2 examinar o poder de discriminar entre as plantas cultivadas sob diferentes condições nutricionais. Mudas de manjericão cultivadas em vermiculita foram

  17. Wire Scanner Motion Control Card

    CERN Document Server

    Forde, S E

    2006-01-01

    Scientists require a certain beam quality produced by the accelerator rings at CERN. The discovery potential of LHC is given by the reachable luminosity at its interaction points. The luminosity is maximized by minimizing the beam size. Therefore an accurate beam size measurement is required for optimizing the luminosity. The wire scanner performs very accurate profile measurements, but as it can not be used at full intensity in the LHC ring, it is used for calibrating other profile monitors. As the current wire scanner system, which is used in the present CERN accelerators, has not been made for the required specification of the LHC, a new design of a wire scanner motion control card is part of the LHC wire scanner project. The main functions of this card are to control the wire scanner motion and to acquire the position of the wire. In case of further upgrades at a later stage, it is required to allow an easy update of the firmware, hence the programmable features of FPGAs will be used for this purpose. The...

  18. Aircraft Scanners = NASA Digital Aerial Scanners (TMS, TIMS, NS001): Pre 1996

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Aircraft Scanners data set contains digital imagery acquired from several multispectral scanners including NS-001 Mutispectral scanner, Daedalus thematic mapper...

  19. The joint measuring technique for auto panel dies based on CMM and optical scanner%采用CMM与光学扫描仪的汽车覆盖件模具联合测量技术

    Institute of Scientific and Technical Information of China (English)

    万军

    2013-01-01

    汽车覆盖件模具型面复杂、特征众多,为保证测量的效率、足够的测点密度及几何特征与模具边界的测量精度,提出采用三坐标测量机与光学扫描仪联合的方式开展汽车覆盖件模具三维测量;分析了联合测量的过程,包括模具清理、模具表面处理与建立参考点系统、测量实施、数据点预处理、数据格式转换,以及数据重定位整合等步骤.阐述了数据重定位整合过程,提出一种基于刚性变换的重定位整合方法,通过移动对齐公共参考点将两种测量数据变换至同一坐标系下,以轿车前围模具的三维测量为例,说明了联合测量技术的实施过程.%As the surface of the auto panel dies is complex and full of features,the coordinate measuring machine and the optical scanner are used jointly in mould measuring to ensure the efficiency and the accuracy. The process of joint measuring includes the cleaning of mould,mould surface treatment and establishing the reference points system, implementing of measurement,pre-processing of data points,format conversion of data points,the relocation of data points and so on. A method based on rigid transformation is put forward, which is used to transform two types of data points to one coordinate system. The procedure of joint measuring is demonstrated by the digitization of auto front longitudinal beam die.

  20. Interferometric Laser Scanner for Direction Determination.

    Science.gov (United States)

    Kaloshin, Gennady; Lukin, Igor

    2016-01-21

    In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5-10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km.

  1. Interferometric Laser Scanner for Direction Determination

    Directory of Open Access Journals (Sweden)

    Gennady Kaloshin

    2016-01-01

    Full Text Available In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5–10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km.

  2. A case study in scanner optimisation.

    Science.gov (United States)

    Dudley, N J; Gibson, N M

    2014-02-01

    Ultrasound scanner preset programmes are factory set or tailored to user requirements. Scanners may, therefore, have different settings for the same application, even on similar equipment in a single department. The aims of this study were: (1) to attempt to match the performance of two scanners, where one was preferred and (2) to assess differences between six scanners used for breast ultrasound within our organisation. The Nottingham Ultrasound Quality Assurance software was used to compare imaging performance. Images of a Gammex RMI 404GS test object were collected from six scanners, using default presets, factory presets and settings matched to a preferred scanner. Resolution, low contrast performance and high contrast performance were measured. The performance of two scanners was successfully matched, where one had been preferred. Default presets varied across the six scanners, three different presets being used. The most used preset differed in settings across the scanners, most notably in the use of different frequency modes. The factory preset was more consistent across the scanners, the main variation being in dynamic range (55-70 dB). Image comparisons showed significant differences, which were reduced or eliminated by adjustment of settings to match a reference scanner. It is possible to match scanner performance using the Nottingham Ultrasound Quality Assurance software as a verification tool. Ultrasound users should be aware that scanners may not behave in a similar fashion, even with apparently equivalent presets. It should be possible to harmonise presets by consensus amongst users.

  3. Compensation strategies for PET scanners with unconventional scanner geometry

    CERN Document Server

    Gundlich, B; Oehler, M

    2006-01-01

    The small animal PET scanner ClearPET®Neuro, developed at the Forschungszentrum Julich GmbH in cooperation with the Crystal Clear Collaboration (CERN), represents scanners with an unconventional geometry: due to axial and transaxial detector gaps ClearPet®Neuro delivers inhomogeneous sinograms with missing data. When filtered backprojection (FBP) or Fourier rebinning (FORE) are applied, strong geometrical artifacts appear in the images. In this contribution we present a method that takes the geometrical sensitivity into account and converts the measured sinograms into homogeneous and complete data. By this means artifactfree images are achieved using FBP or FORE. Besides an advantageous measurement setup that reduces inhomogeneities and data gaps in the sinograms, a modification of the measured sinograms is necessary. This modification includes two steps: a geometrical normalization and corrections for missing data. To normalize the measured sinograms, computed sinograms are used that describe the geometric...

  4. High-speed two-dimensional laser scanner based on Bragg gratings stored in photothermorefractive glass.

    Science.gov (United States)

    Yaqoob, Zahid; Arain, Muzammil A; Riza, Nabeel A

    2003-09-10

    A high-speed free-space wavelength-multiplexed optical scanner with high-speed wavelength selection coupled with narrowband volume Bragg gratings stored in photothermorefractive (PTR) glass is reported. The proposed scanner with no moving parts has a modular design with a wide angular scan range, accurate beam pointing, low scanner insertion loss, and two-dimensional beam scan capabilities. We present a complete analysis and design procedure for storing multiple tilted Bragg-grating structures in a single PTR glass volume (for normal incidence) in an optimal fashion. Because the scanner design is modular, many PTR glass volumes (each having multiple tilted Bragg-grating structures) can be stacked together, providing an efficient throughput with operations in both the visible and the infrared (IR) regions. A proof-of-concept experimental study is conducted with four Bragg gratings in independent PTR glass plates, and both visible and IR region scanner operations are demonstrated.

  5. Whole-body 35-GHz security scanner

    Science.gov (United States)

    Appleby, Roger; Anderton, Rupert N.; Price, Sean; Sinclair, Gordon N.; Coward, Peter R.

    2004-08-01

    A 35GHz imager designed for Security Scanning has been previously demonstrated. That imager was based on a folded conical scan technology and was constructed from low cost materials such as expanded polystyrene and printed circuit board. In conjunction with an illumination chamber it was used to collect indoor imagery of people with weapons and contraband hidden under their clothing. That imager had a spot size of 20mm and covered a field of view of 20 x 10 degrees that partially covered the body of an adult from knees to shoulders. A new variant of this imager has been designed and constructed. It has a field of view of 36 x 18 degrees and is capable of covering the whole body of an adult. This was achieved by increasing the number of direct detection receivers from the 32 used in the previous design to 58, and by implementing an improved optical design. The optics consist of a front grid, a polarisation device which converts linear to circular polarisation and a rotating scanner. This new design uses high-density expanded polystyrene as a correcting element on the back of the front grid. This gives an added degree of freedom that allows the optical design to be diffraction limited over a very wide field of view. Obscuration by the receivers and associated components is minimised by integrating the post detection electronics at the receiver array.

  6. A New Proton CT Scanner

    CERN Document Server

    Coutrakon, G; Boi, S; Dyshkant, A; Erdelyi, B; Hedin, D; Johnson, E; Krider, J; Rykalin, V; Uzunyan, S A; Zutshi, V; Fordt, R; Sellberg, G; Rauch, J E; Roman, M; Rubinov, P; Wilson, P; Naimuddin, M

    2014-01-01

    The design, construction, and preliminary testing of a second generation proton CT scanner is presented. All current treatment planning systems at proton therapy centers use X-ray CT as the primary imaging modality for treatment planning to calculate doses to tumor and healthy tissues. One of the limitations of X-ray CT is in the conversion of X-ray attenuation coefficients to relative (proton) stopping powers, or RSP. This results in more proton range uncertainty, larger target volumes and therefore, more dose to healthy tissues. To help improve this, we present a novel scanner capable of high dose rates, up to 2~MHz, and large area coverage, 20~x~24~cm$^2$, for imaging an adult head phantom and reconstructing more accurate RSP values.

  7. 采用体积轮廓扫描仪直接测量口腔印模材料的尺寸变化率%Evaluatoin of the accuracy of 4 impression materials by a 3D optical scanner

    Institute of Scientific and Technical Information of China (English)

    罗子源; 唐亮; 许晶晶; 刘迪生

    2015-01-01

    目的:测量4种临床常用 EP 模材的三维形变率。方法:制作母模及个别托盘,使用2种藻酸盐和2种橡胶 EP 模材在母模上分别制取 EP 模材试件(n =3),用三维轮廓测量扫描仪进行扫描及建模,通过计算机测量模型3个轴向上标记线段长度的变化。结果:在印模120 min 后,Zhermark 藻酸盐在3个轴向上的变化率分别为3.615%、3.037%、2.836%;CAVEX 藻酸盐的变化率分别为2.836%、3.358%、4.276%;在印模8 h 后,Impregum Penta 聚醚橡胶在3个轴向上的变化率分别为0.039%、0.071%、0.057%;ExpressXT Penta H 加成硅橡胶的变化率分别为0.033%、0.088%、0.084%。结论:4种材料线性尺寸变化率均达到 ISO1563∶1990标准,藻酸盐类 EP 模材在3个轴向上的形变率均明显大于橡胶类 EP 模材。%Objective:To study the 3D accuracy of 4 impression materials.Methods:A metal mould with a custom tray was prepared for the measurement.Impression samples of 2 alginate and 2 rubber impression materials were prepared in the metal mould(n =3)re-spectively.The length of three tagged lines,along X,Y,Z axis directions of the samples was measured with a 3D optical scanner.Re-sults:120 min after sampling the variable rates of the length along X,Y,Z axis of Zhermark alginate samples were 3.615%,3.037%and 2.836%,those of CAVEX alginate samples were 2.836%,3.358% and 4.276% respectively;8 h after sampling the variable rates of Impregum Penta polyether rubber samples were 0.039%,0.071% and 0.057%,those of ExpressXT Penta H addition-curing silicone rubber samples were 0.033%,0.088% and 0.084% respectively.Conclusion:The variable rates of the 4 impression materi-als are in accordance with ISO1563∶1990.The variable rate of alginate impression material is greater than that of rubber.

  8. In vivo cellular imaging with microscopes enabled by MEMS scanners

    Science.gov (United States)

    Ra, Hyejun

    High-resolution optical imaging plays an important role in medical diagnosis and biomedical research. Confocal microscopy is a widely used imaging method for obtaining cellular and sub-cellular images of biological tissue in reflectance and fluorescence modes. Its characteristic optical sectioning capability also enables three-dimensional (3-D) image reconstruction. However, its use has mostly been limited to excised tissues due to the requirement of high numerical aperture (NA) lenses for cellular resolution. Microscope miniaturization can enable in vivo imaging to make possible early cancer diagnosis and biological studies in the innate environment. In this dissertation, microscope miniaturization for in vivo cellular imaging is presented. The dual-axes confocal (DAC) architecture overcomes limitations of the conventional single-axis confocal (SAC) architecture to allow for miniaturization with high resolution. A microelectromechanical systems (MEMS) scanner is the central imaging component that is key in miniaturization of the DAC architecture. The design, fabrication, and characterization of the two-dimensional (2-D) MEMS scanner are presented. The gimbaled MEMS scanner is fabricated on a double silicon-on-insulator (SOI) wafer and is actuated by self-aligned vertical electrostatic combdrives. The imaging performance of the MEMS scanner in a DAC configuration is shown in a breadboard microscope setup, where reflectance and fluorescence imaging is demonstrated. Then, the MEMS scanner is integrated into a miniature DAC microscope. The whole imaging system is integrated into a portable unit for research in small animal models of human biology and disease. In vivo 3-D imaging is demonstrated on mouse skin models showing gene transfer and siRNA silencing. The siRNA silencing process is sequentially imaged in one mouse over time.

  9. Scanner color management model based on improved back-propagation neural network

    Institute of Scientific and Technical Information of China (English)

    Xinwu Li

    2008-01-01

    Scanner color management is one of the key techniques for color reproduction in information optics.A new scanner color management model is presented based on analyzing rendering principle of scanning objects.In this model,a standard color target is taken as experimental sample.Color blocks in color shade area are used to substitute complete color space to solve the difficulties in selecting experimental color blocks.Immune genetic algorithm is used to correct back-propagation neural network(BPNN)to speed up the convergence of the model.Experimental results show that the model can improve the accuracy of scanner color management.

  10. Optimization of PET scanner geometry

    Energy Technology Data Exchange (ETDEWEB)

    Adam, Lars-Eric; Karp, J.S. [Univ. of Pennsylvania, Department of Radiology, Philadelphia, PA (United States)

    2000-12-01

    Modern positron emission tomographs (PET), when used for 3D imaging, have a wide open gantry without intra plane septa and only little shielding. In order to reduce the scatter contamination from activity inside and outside the field-of-view (FOV), and to block radiation originating from activity outside-the-FOV, we have investigated the implementation of septa and additional patient shielding on our existing whole body PET scanner. A series of Monte Carlo simulations, based on EGS4, were performed to predict the potential benefits. Our simulations include point and line sources at various radial and axial positions in the FOV of the scanner, and different sized uniform cylinders (up to 100 cm long and 50 cm in diameter). The scanner itself is based on 6 continuous NaI(Tl) crystals, an axial FOV of 25.6 cm, a ring diameter of 90 cm, and a transaxial FOV of 56 cm. The results show that septa can reduce the relative scatter fraction and effectively block radiation from outside-the-FOV, but they also reduce the sensitivity for true events, leading to a decrease of the trues-to-singles ratio that is not desirable. The use of septa is only advantageous for large objects, if the loss of true events is compensated for by increasing the injected activity. Patient shields that are mounted outside-the-FOV reduce the contamination from scattered and single events without interfering with true events. They are more effective for objects with a small diameter and less effective for objects with a large diameter. (author)

  11. Open magnetic resonance imaging (MRI) scanners.

    Science.gov (United States)

    Hailey, D

    2006-11-01

    (1) In most MRI scanners, the patient examination table fits inside a long cylindrical tube. Large patients cannot be accommodated, and some persons experience claustrophobic reactions. Open MRI systems, in which the patient is placed between two plates, overcome these disadvantages. (2) Open MRI scanners are widely used in health care. High-field closed MRI systems are preferred for many examinations. (3) Early versions of open MRI scanners had low magnetic field strength, gave poorer image quality than most closed systems, and required longer examination times. Newer open scanners include machines with higher magnetic field strengths and improved image quality. (4) Closed high magnetic field scanners with short magnets and wide bore tubes offer improved comfort to patients, and may be an alternative to open scanners. (5) There is interest in using open systems for intra-operative and image-guided interventions.

  12. Development of a high resolution module for PET scanners

    Science.gov (United States)

    Stringhini, G.; Pizzichemi, M.; Ghezzi, A.; Stojkovic, A.; Tavernier, S.; Niknejad, T.; Varela, J.; Paganoni, M.; Auffray, E.

    2017-02-01

    Positron Emission Tomography (PET) scanners require high performances in term of spatial resolution and sensitivity to allow early detection of cancer masses. In small animal and organ dedicated PET scanners the Depth of Interaction (DOI) information has to be obtained to avoid parallax errors and to reconstruct high resolution images. In the whole body PET, the DOI information can be useful to correct for the time jitter of the optical photons along the main axis of the scintillator, improving the time performances. In this work we present the development of PET module designed to reach high performance as compared to the current scanners while keeping the complexity of the system reasonably low. The module presented is based on a 64 LYSO (Lutetium-yttrium oxyorthosilicate) crystals matrix and on a 4×4 MPPC (Multi Pixels Photon Counter) array as detector in a 4 to 1 coupling between the crystals and the detector and a single side readout. The lateral surfaces of the crystals are optically treated to be unpolished. The DOI and the energy resolution of the PET module are presented and a fast method to obtain the DOI calibration is discussed.

  13. Lensless image scanner using multilayered aperture array for noncontact imaging

    Science.gov (United States)

    Kawano, Hiroyuki

    2016-10-01

    We propose a new imaging system of a simple structure that uses a set of layered aperture arrays above a linear image sensor instead of an imaging lens. The image scanner transfers the image information by detecting the scattering rays from the object directly without any collecting power, as if it were an optical stamp. Since the aperture arrays shield the stray rays propagating obliquely, the image information can be read with high resolution even if the object floats within a few millimeters. The aperture arrays with staggered alignment in two lines widen the space with the adjacent pixel without decimating information. We manufactured a prototype model of 300-dpi resolution, whose height is as little as 5 mm. The experimental result shows that ghost images can be restricted sufficiently, and our scanner can clearly read an object within a space of <3.5 mm, meaning that it has a large depth of field of 3.5 mm.

  14. Absolute dosimetric characterization of Gafchromic EBT3 and HDv2 films using commercial flat-bed scanners and evaluation of the scanner response function variability

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S. N.; Revet, G.; Fuchs, J. [LULI-CNRS, Ecole Polytechnique, CEA: Universite Paris-Saclay, UPMC Univ Paris 06, Sorbonne Universities, F-91128 Palaiseau Cedex (France); Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation); Gauthier, M.; Glenzer, S.; Propp, A. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Bazalova-Carter, M. [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8P 5C2 (Canada); Bolanos, S. [LULI-CNRS, Ecole Polytechnique, CEA: Universite Paris-Saclay, UPMC Univ Paris 06, Sorbonne Universities, F-91128 Palaiseau Cedex (France); Riquier, R. [LULI-CNRS, Ecole Polytechnique, CEA: Universite Paris-Saclay, UPMC Univ Paris 06, Sorbonne Universities, F-91128 Palaiseau Cedex (France); CEA, DAM, DIF, F-91297 Arpajon (France); Antici, P. [INRS-EMT, Varennes, J3X1S2 Québec (Canada); Morabito, A. [ELI-ALPS, ELI-HU non profit kft, Dugonics ter 13, H-6720, Szeged (Hungary); Starodubtsev, M. [Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod (Russian Federation)

    2016-07-15

    Radiochromic films (RCF) are commonly used in dosimetry for a wide range of radiation sources (electrons, protons, and photons) for medical, industrial, and scientific applications. They are multi-layered, which includes plastic substrate layers and sensitive layers that incorporate a radiation-sensitive dye. Quantitative dose can be retrieved by digitizing the film, provided that a prior calibration exists. Here, to calibrate the newly developed EBT3 and HDv2 RCFs from Gafchromic™, we used the Stanford Medical LINAC to deposit in the films various doses of 10 MeV photons, and by scanning the films using three independent EPSON Precision 2450 scanners, three independent EPSON V750 scanners, and two independent EPSON 11000XL scanners. The films were scanned in separate RGB channels, as well as in black and white, and film orientation was varied. We found that the green channel of the RGB scan and the grayscale channel are in fact quite consistent over the different models of the scanner, although this comes at the cost of a reduction in sensitivity (by a factor ∼2.5 compared to the red channel). To allow any user to extend the absolute calibration reported here to any other scanner, we furthermore provide a calibration curve of the EPSON 2450 scanner based on absolutely calibrated, commercially available, optical density filters.

  15. Laser Scanner For Automatic Storage

    Science.gov (United States)

    Carvalho, Fernando D.; Correia, Bento A.; Rebordao, Jose M.; Rodrigues, F. Carvalho

    1989-01-01

    The automated magazines are beeing used at industry more and more. One of the problems related with the automation of a Store House is the identification of the products envolved. Already used for stock management, the Bar Codes allows an easy way to identify one product. Applied to automated magazines, the bar codes allows a great variety of items in a small code. In order to be used by the national producers of automated magazines, a devoted laser scanner has been develloped. The Prototype uses an He-Ne laser whose beam scans a field angle of 75 degrees at 16 Hz. The scene reflectivity is transduced by a photodiode into an electrical signal, which is then binarized. This digital signal is the input of the decodifying program. The machine is able to see barcodes and to decode the information. A parallel interface allows the comunication with the central unit, which is responsible for the management of automated magazine.

  16. Non-Destructive Testing Scanner

    Science.gov (United States)

    1990-01-01

    Bio-Imaging Research's technology that originated in an aerospace program has come full circle with a new aerospace adaptation called the Advanced Computed Tomography Inspection System, or ACTIS. The medical version of CT scans the human body for tumors or other abnormalities, the ACTIS system finds imperfections in aerospace structures and components, such as castings, assemblies, rocket motors and nozzles. ACTIS is described by its developer as the most versatile CT scanner available for non-destructive testing applications. ACTIS is a variable geometry system. ACTIS source and detectors can be moved closer together or farther apart to optimize the geometry for different sizes of test objects. The combination of variable geometry, three sources, and focusing detectors makes ACTIS cost effective for a broad range of applications. System can scan anything from very small turbine blades to large rocket assemblies.

  17. Combined PET/MRI scanner

    Science.gov (United States)

    Schlyer, David; Woody, Craig L.; Rooney, William; Vaska, Paul; Stoll, Sean; Pratte, Jean-Francois; O'Connor, Paul

    2007-10-23

    A combined PET/MRI scanner generally includes a magnet for producing a magnetic field suitable for magnetic resonance imaging, a radiofrequency (RF) coil disposed within the magnetic field produced by the magnet and a ring tomograph disposed within the magnetic field produced by the magnet. The ring tomograph includes a scintillator layer for outputting at least one photon in response to an annihilation event, a detection array coupled to the scintillator layer for detecting the at least one photon outputted by the scintillator layer and for outputting a detection signal in response to the detected photon and a front-end electronic array coupled to the detection array for receiving the detection signal, wherein the front-end array has a preamplifier and a shaper network for conditioning the detection signal.

  18. 3D whole body scanners revisited

    NARCIS (Netherlands)

    Daanen, H.A.M.; Haar, F.B. ter

    2013-01-01

    An overview of whole body scanners in 1998 (H.A.M. Daanen, G.J. Van De Water. Whole body scanners, Displays 19 (1998) 111-120) shortly after they emerged to the market revealed that the systems were bulky, slow, expensive and low in resolution. This update shows that new developments in sensing and

  19. Long-Range WindScanner System

    DEFF Research Database (Denmark)

    Vasiljevic, Nikola; Lea, Guillaume; Courtney, Michael

    2016-01-01

    The technical aspects of a multi-Doppler LiDAR instrument, the long-range WindScanner system, are presented accompanied by an overview of the results from several field campaigns. The long-range WindScanner system consists of three spatially-separated, scanning coherent Doppler LiDARs and a remot...

  20. Polarization property analysis of a periscopic scanner with three-dimensional polarization ray-tracing calculus.

    Science.gov (United States)

    Yang, Yufei; Yan, Changxiang

    2016-02-20

    The polarization properties of a two-axis periscopic optical scanner constituted by a pair of rotating planar mirrors have been studied by using the three-dimensional polarization ray-tracing matrix method. The separate and cumulative matrices that define the transformation of the polarization state are obtained and expressed in terms of the rotation angles of two mirrors. The variations of diattenuation and retardance are investigated and graphically shown as functions of the rotation angles. On this basis, a further investigation about the cumulative polarization aberrations of three different metal-coated periscopic scanners is accomplished. Finally, the output polarization states of the three metal-coated scanners are calculated with the input beam of the arbitrary polarization states, and the results show that aluminum film is more appropriate than gold film or silver film for the polarization-maintaining periscopic scanner.

  1. Evaluating Commercial Scanners for Astronomical Image Digitization

    Science.gov (United States)

    Simcoe, R. J.

    2009-08-01

    Many organizations have been interested in understanding if commercially available scanners are adequate for scientifically useful digitization. These scanners range in price from a few hundred to a few tens of thousands of dollars (USD), often with little apparent difference in performance specifications. This paper describes why the underlying technology used in flatbed scanners tends to effectively limit resolutions to the 600-1200 dots per inch (dpi) range and how the overall system Modulation Transfer Function (MTF) can be used to evaluate the quality of the digitized data for the small feature sizes found in astronomical images. Two scanners, the Epson V750 flatbed scanner and the Nikon Cool Scan 9000ED film strip scanner, are evaluated through their Modulation Transfer Functions (MTF). The MTF of the Harvard DASCH scanner is also shown for comparison. The particular goal of this evaluation was to understand if the scanners could be used for digitizing spectral plates at the University of Toronto. The plates of primary interest were about 15 mm (5/8 inch) wide by 180 mm (7~inches) long and ˜50 mm x 80 mm (2 x 3 inches). The results of the MTF work show that the Epson scanner, despite claims of high resolution, is of limited value for scientific imaging of feature sizes below about 50 μm and therefore not a good candidate for digitizing the spectral plates and problematic for scanning direct plates. The Nikon scanner is better and, except for some frustrating limitations in its software, its performance seems to hold promise as a digitizer for spectral plates in the University of Toronto collection.

  2. Using Laser Scanners to Augment the Systematic Error Pointing Model

    Science.gov (United States)

    Wernicke, D. R.

    2016-08-01

    The antennas of the Deep Space Network (DSN) rely on precise pointing algorithms to communicate with spacecraft that are billions of miles away. Although the existing systematic error pointing model is effective at reducing blind pointing errors due to static misalignments, several of its terms have a strong dependence on seasonal and even daily thermal variation and are thus not easily modeled. Changes in the thermal state of the structure create a separation from the model and introduce a varying pointing offset. Compensating for this varying offset is possible by augmenting the pointing model with laser scanners. In this approach, laser scanners mounted to the alidade measure structural displacements while a series of transformations generate correction angles. Two sets of experiments were conducted in August 2015 using commercially available laser scanners. When compared with historical monopulse corrections under similar conditions, the computed corrections are within 3 mdeg of the mean. However, although the results show promise, several key challenges relating to the sensitivity of the optical equipment to sunlight render an implementation of this approach impractical. Other measurement devices such as inclinometers may be implementable at a significantly lower cost.

  3. Label-free tissue scanner for colorectal cancer screening

    Science.gov (United States)

    Kandel, Mikhail E.; Sridharan, Shamira; Liang, Jon; Luo, Zelun; Han, Kevin; Macias, Virgilia; Shah, Anish; Patel, Roshan; Tangella, Krishnarao; Kajdacsy-Balla, Andre; Guzman, Grace; Popescu, Gabriel

    2017-06-01

    The current practice of surgical pathology relies on external contrast agents to reveal tissue architecture, which is then qualitatively examined by a trained pathologist. The diagnosis is based on the comparison with standardized empirical, qualitative assessments of limited objectivity. We propose an approach to pathology based on interferometric imaging of "unstained" biopsies, which provides unique capabilities for quantitative diagnosis and automation. We developed a label-free tissue scanner based on "quantitative phase imaging," which maps out optical path length at each point in the field of view and, thus, yields images that are sensitive to the "nanoscale" tissue architecture. Unlike analysis of stained tissue, which is qualitative in nature and affected by color balance, staining strength and imaging conditions, optical path length measurements are intrinsically quantitative, i.e., images can be compared across different instruments and clinical sites. These critical features allow us to automate the diagnosis process. We paired our interferometric optical system with highly parallelized, dedicated software algorithms for data acquisition, allowing us to image at a throughput comparable to that of commercial tissue scanners while maintaining the nanoscale sensitivity to morphology. Based on the measured phase information, we implemented software tools for autofocusing during imaging, as well as image archiving and data access. To illustrate the potential of our technology for large volume pathology screening, we established an "intrinsic marker" for colorectal disease that detects tissue with dysplasia or colorectal cancer and flags specific areas for further examination, potentially improving the efficiency of existing pathology workflows.

  4. Experimental characterization of the Clear-PEM scanner spectrometric performance

    Science.gov (United States)

    Bugalho, R.; Carriço, B.; Ferreira, C. S.; Frade, M.; Ferreira, M.; Moura, R.; Ortigão, C.; Pinheiro, J. F.; Rodrigues, P.; Rolo, I.; Silva, J. C.; Trindade, A.; Varela, J.

    2009-10-01

    In the framework of the Clear-PEM project for the construction of a high-resolution and high-specificity scanner for breast cancer imaging, a Positron Emission Mammography tomograph has been developed and installed at the Instituto Português de Oncologia do Porto hospital. The Clear-PEM scanner is mainly composed by two planar detector heads attached to a robotic arm, trigger/data acquisition electronics system and computing servers. The detector heads hold crystal matrices built from 2 × 2 × 20 mm3 LYSO:Ce crystals readout by Hamamatsu S8550 APD arrays. The APDs are optically coupled to both ends of the 6144 crystals in order to extract the DOI information for each detected event. Each one of 12288 APD's pixels is read and controlled by Application Specific Integrated Circuits water-cooled by an external cooling unit. The Clear-PEM frontend boards innovative design results in a unprecedented integration of the crystal matrices, APDs and ASICs, making Clear-PEM the PET scanner with the highest number of APD pixels ever integrated so far. In this paper, the scanner's main technical characteristics, calibration strategies and the first spectrometric performance evaluation in a clinical environment are presented. The first commissioning results show 99.7% active channels, which, after calibration, have inter-pixel and absolute gain distributions with dispersions of, respectively, 12.2% and 15.3%, demonstrating that despite the large number of channels, the system is uniform. The mean energy resolution at 511 keV is of 15.9%, with a 8.8% dispersion, and the mean CDOI-1 is 5.9%/mm, with a 7.8% dispersion. The coincidence time resolution, at 511 keV, for a energy window between 400 and 600 keV, is 5.2 ns FWHM.

  5. Dynamic 3D computed tomography scanner for vascular imaging

    Science.gov (United States)

    Lee, Mark K.; Holdsworth, David W.; Fenster, Aaron

    2000-04-01

    A 3D dynamic computed-tomography (CT) scanner was developed for imaging objects undergoing periodic motion. The scanner system has high spatial and sufficient temporal resolution to produce quantitative tomographic/volume images of objects such as excised arterial samples perfused under physiological pressure conditions and enables the measurements of the local dynamic elastic modulus (Edyn) of the arteries in the axial and longitudinal directions. The system was comprised of a high resolution modified x-ray image intensifier (XRII) based computed tomographic system and a computer-controlled cardiac flow simulator. A standard NTSC CCD camera with a macro lens was coupled to the electro-optically zoomed XRII to acquire dynamic volumetric images. Through prospective cardiac gating and computer synchronized control, a time-resolved sequence of 20 mm thick high resolution volume images of porcine aortic specimens during one simulated cardiac cycle were obtained. Performance evaluation of the scanners illustrated that tomographic images can be obtained with resolution as high as 3.2 mm-1 with only a 9% decrease in the resolution for objects moving at velocities of 1 cm/s in 2D mode and static spatial resolution of 3.55 mm-1 with only a 14% decrease in the resolution in 3D mode for objects moving at a velocity of 10 cm/s. Application of the system for imaging of intact excised arterial specimens under simulated physiological flow/pressure conditions enabled measurements of the Edyn of the arteries with a precision of +/- kPa for the 3D scanner. Evaluation of the Edyn in the axial and longitudinal direction produced values of 428 +/- 35 kPa and 728 +/- 71 kPa, demonstrating the isotropic and homogeneous viscoelastic nature of the vascular specimens. These values obtained from the Dynamic CT systems were not statistically different (p less than 0.05) from the values obtained by standard uniaxial tensile testing and volumetric measurements.

  6. Experimental characterization of the Clear-PEM scanner spectrometric performance

    Energy Technology Data Exchange (ETDEWEB)

    Bugalho, R; Carrico, B; Ferreira, C S; Frade, M; Ferreira, M; Moura, R; Ortigao, C; Pinheiro, J F; Rodrigues, P; Rolo, I; Silva, J C; Trindade, A; Varela, J [Laboratorio de Instrumentacao e Fisica Experimental de Particulas (LIP), Av. Elias Garcia 14-1, 1000-149 Lisboa (Portugal)], E-mail: frade@lip.pt

    2009-10-15

    In the framework of the Clear-PEM project for the construction of a high-resolution and high-specificity scanner for breast cancer imaging, a Positron Emission Mammography tomograph has been developed and installed at the Instituto Portugues de Oncologia do Porto hospital. The Clear-PEM scanner is mainly composed by two planar detector heads attached to a robotic arm, trigger/data acquisition electronics system and computing servers. The detector heads hold crystal matrices built from 2 x 2 x 20 mm{sup 3} LYSO:Ce crystals readout by Hamamatsu S8550 APD arrays. The APDs are optically coupled to both ends of the 6144 crystals in order to extract the DOI information for each detected event. Each one of 12288 APD's pixels is read and controlled by Application Specific Integrated Circuits water-cooled by an external cooling unit. The Clear-PEM frontend boards innovative design results in a unprecedented integration of the crystal matrices, APDs and ASICs, making Clear-PEM the PET scanner with the highest number of APD pixels ever integrated so far. In this paper, the scanner's main technical characteristics, calibration strategies and the first spectrometric performance evaluation in a clinical environment are presented. The first commissioning results show 99.7% active channels, which, after calibration, have inter-pixel and absolute gain distributions with dispersions of, respectively, 12.2% and 15.3%, demonstrating that despite the large number of channels, the system is uniform. The mean energy resolution at 511 keV is of 15.9%, with a 8.8% dispersion, and the mean C{sub DOI}{sup -1} is 5.9%/mm, with a 7.8% dispersion. The coincidence time resolution, at 511 keV, for a energy window between 400 and 600 keV, is 5.2 ns FWHM.

  7. A Cross-Platform Smartphone Brain Scanner

    DEFF Research Database (Denmark)

    Larsen, Jakob Eg; Stopczynski, Arkadiusz; Stahlhut, Carsten

    We describe a smartphone brain scanner with a low-costwireless 14-channel Emotiv EEG neuroheadset interfacingwith multiple mobile devices. This personal informaticssystem enables minimally invasive and continuouscapturing of brain imaging data in natural settings. Thesystem applies an inverse...

  8. Improved Scanners for Microscopic Hyperspectral Imaging

    Science.gov (United States)

    Mao, Chengye

    2009-01-01

    Improved scanners to be incorporated into hyperspectral microscope-based imaging systems have been invented. Heretofore, in microscopic imaging, including spectral imaging, it has been customary to either move the specimen relative to the optical assembly that includes the microscope or else move the entire assembly relative to the specimen. It becomes extremely difficult to control such scanning when submicron translation increments are required, because the high magnification of the microscope enlarges all movements in the specimen image on the focal plane. To overcome this difficulty, in a system based on this invention, no attempt would be made to move either the specimen or the optical assembly. Instead, an objective lens would be moved within the assembly so as to cause translation of the image at the focal plane: the effect would be equivalent to scanning in the focal plane. The upper part of the figure depicts a generic proposed microscope-based hyperspectral imaging system incorporating the invention. The optical assembly of this system would include an objective lens (normally, a microscope objective lens) and a charge-coupled-device (CCD) camera. The objective lens would be mounted on a servomotor-driven translation stage, which would be capable of moving the lens in precisely controlled increments, relative to the camera, parallel to the focal-plane scan axis. The output of the CCD camera would be digitized and fed to a frame grabber in a computer. The computer would store the frame-grabber output for subsequent viewing and/or processing of images. The computer would contain a position-control interface board, through which it would control the servomotor. There are several versions of the invention. An essential feature common to all versions is that the stationary optical subassembly containing the camera would also contain a spatial window, at the focal plane of the objective lens, that would pass only a selected portion of the image. In one version

  9. Uncertainty Propagation for Terrestrial Mobile Laser Scanner

    Science.gov (United States)

    Mezian, c.; Vallet, Bruno; Soheilian, Bahman; Paparoditis, Nicolas

    2016-06-01

    Laser scanners are used more and more in mobile mapping systems. They provide 3D point clouds that are used for object reconstruction and registration of the system. For both of those applications, uncertainty analysis of 3D points is of great interest but rarely investigated in the literature. In this paper we present a complete pipeline that takes into account all the sources of uncertainties and allows to compute a covariance matrix per 3D point. The sources of uncertainties are laser scanner, calibration of the scanner in relation to the vehicle and direct georeferencing system. We suppose that all the uncertainties follow the Gaussian law. The variances of the laser scanner measurements (two angles and one distance) are usually evaluated by the constructors. This is also the case for integrated direct georeferencing devices. Residuals of the calibration process were used to estimate the covariance matrix of the 6D transformation between scanner laser and the vehicle system. Knowing the variances of all sources of uncertainties, we applied uncertainty propagation technique to compute the variance-covariance matrix of every obtained 3D point. Such an uncertainty analysis enables to estimate the impact of different laser scanners and georeferencing devices on the quality of obtained 3D points. The obtained uncertainty values were illustrated using error ellipsoids on different datasets.

  10. Three-Dimensional Accuracy of Facial Scan for Facial Deformities in Clinics: A New Evaluation Method for Facial Scanner Accuracy

    OpenAIRE

    Zhao, Yi-jiao; Xiong, Yu-xue; Wang, Yong

    2017-01-01

    In this study, the practical accuracy (PA) of optical facial scanners for facial deformity patients in oral clinic was evaluated. Ten patients with a variety of facial deformities from oral clinical were included in the study. For each patient, a three-dimensional (3D) face model was acquired, via a high-accuracy industrial “line-laser” scanner (Faro), as the reference model and two test models were obtained, via a “stereophotography” (3dMD) and a “structured light” facial scanner (FaceScan) ...

  11. Fret Replica Inspection Laser Scanner (FRILS)

    Energy Technology Data Exchange (ETDEWEB)

    Kretz, S.; Hanley, K., E-mail: steve.kretz@opg.com, E-mail: kelly.hanley@opg.com [Ontario Power Generation, Inspection Maintenance and Commercial Services, Pickering, Ontario (Canada)

    2008-07-01

    provides the knowledge of the flaw geometry that could ease restrictions placed on the unit based on the cycle limitations due to the flaw assessment.Once the replica is produced it is inspected utilizing the Fret Replication Inspection Laser Scanner System (FRILS). The results obtained from the FRILS scans are utilized in the flaw assessment. These scans provide information on the flaw geometry - length, width, depth, and root radius of the flaw. In basic terms, root radius is a measure of how sharp the edges are in the defect. The resultant data is utilized in the stress analysis calculation that ultimately determines how many shutdown cycles that the reactor can have before that flaw must be re-inspected. The FRILS System utilizes light profilometry. A narrow light stripe is projected onto the replica surface, a camera with zoom optics is positioned at a calculated angle to the surface and this image is then projected onto a calibrated monitor. An image processor extracts and digitizes the surface profile. FRILS custom designed software is used in the collection and analysis of this data. This paper will present details of the FRILS system capabilities, the evolution to the second generation FRILS system and field execution of the FRILS Inspections at Ontario Power Generation reactors. (author)

  12. Sensitivity of linear CCD array based film scanners used for film dosimetry.

    Science.gov (United States)

    Devic, Slobodan; Wang, Yi-Zhen; Tomic, Nada; Podgorsak, Ervin B

    2006-11-01

    Film dosimetry is commonly performed by using linear CCD array transmission optical densitometers. However, these devices suffer from a variation in response along the detector array. If not properly corrected for, this nonuniformity may lead to significant overestimations of the measured dose as one approaches regions close to the edges of the scanning region. In this note, we present measurements of the spatial response of an AGFA Arcus II document scanner used for radiochromic film dosimetry. Results and methods presented in this work can be generalized to other CCD based transmission scanners used for film dosimetry employing either radiochromic or radiographic films.

  13. Manually operated small envelope scanner system

    Energy Technology Data Exchange (ETDEWEB)

    Sword, Charles Keith

    2017-04-18

    A scanner system and method for acquisition of position-based ultrasonic inspection data are described. The scanner system includes an inspection probe and a first non-contact linear encoder having a first sensor and a first scale to track inspection probe position. The first sensor is positioned to maintain a continuous non-contact interface between the first sensor and the first scale and to maintain a continuous alignment of the first sensor with the inspection probe. The scanner system may be used to acquire two-dimensional inspection probe position data by including a second non-contact linear encoder having a second sensor and a second scale, the second sensor positioned to maintain a continuous non-contact interface between the second sensor and the second scale and to maintain a continuous alignment of the second sensor with the first sensor.

  14. A flexible and wearable terahertz scanner

    Science.gov (United States)

    Suzuki, D.; Oda, S.; Kawano, Y.

    2016-12-01

    Imaging technologies based on terahertz (THz) waves have great potential for use in powerful non-invasive inspection methods. However, most real objects have various three-dimensional curvatures and existing THz technologies often encounter difficulties in imaging such configurations, which limits the useful range of THz imaging applications. Here, we report the development of a flexible and wearable THz scanner based on carbon nanotubes. We achieved room-temperature THz detection over a broad frequency band ranging from 0.14 to 39 THz and developed a portable THz scanner. Using this scanner, we performed THz imaging of samples concealed behind opaque objects, breakages and metal impurities of a bent film and multi-view scans of a syringe. We demonstrated a passive biometric THz scan of a human hand. Our results are expected to have considerable implications for non-destructive and non-contact inspections, such as medical examinations for the continuous monitoring of health conditions.

  15. Characterization of the Ferrara animal PET scanner

    CERN Document Server

    Di Domenico, G; Damiani, C; Del Guerra, A; Gilardi, M C; Motta, A; Zavattini, G

    2002-01-01

    A dedicated small animal PET scanner, YAPPET, was designed and built at Ferrara University. Each detector consists of a 20x20 matrix of 2x2x30 mm sup 3 YAP:Ce finger-like crystals glued together and directly coupled to a Hamamatsu position sensitive photomultiplier. The scanner is made from four detectors positioned on a rotating gantry at a distance of 7.5 cm from the center and the field of view (FOV) is 4 cm both in the transaxial direction and in the axial direction. The system operates in 3D acquisition mode. The performance parameters of YAPPET scanner such as spatial, energy and time resolution, as well as its sensitivity and counting rate have been determined. The average spatial resolution over the whole FOV is 1.8 mm at FWHM and 4.2 mm at FWTM. The sensitivity at the center is 640 cps/mu Ci.

  16. Advancements on galvanometer scanners for high-end applications

    Science.gov (United States)

    Duma, Virgil-Florin; Rolland, Jannick P.

    2014-03-01

    Galvanometer-based scanners (GSs) are the most utilized devices for lateral scanning. Their applications range from commercial and industrial to biomedical imaging. They are used mostly for 2-D scanning (with typically two GSs), but also for 1-D or 3-D scanning (the latter by example with GSs in combination with Risley prisms). This paper presents an overview of our contributions in the field of GSs with regard to the requirements of their most challenging applications. Specifically, we studied the optimal scanning functions - to produce the maximum possible duty cycleη, and we found that, contrary to what has been stated in the literature, the scanning function that provides the highest η is not linear plus sinusoidal, but linear plus parabolic. The most common GS input signals (i.e., sawtooth, triangular, and sinusoidal) were investigated experimentally to determine the scanning regimes that produce the minimum image artifacts, for example in Optical Coherence Tomography (OCT). The triangular signal was thus shown to be the best from this point of view, and several rules-of-thumb were extracted to make the best of GSs in OCT. We also discuss aspects of the command functions of GSs that are necessary to achieve a trade-off between a performance criteria related to the duty cycle and voltage regimes of the device. We finally review aspects of the control solutions of GSs we investigated, to obtain the highest possible precision or the fastest possible response of the scanner.

  17. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  18. Dedicated PET scanners for breast imaging

    Energy Technology Data Exchange (ETDEWEB)

    Freifelder, Richard; Karp, Joel S. [University of Pennsylvania, Department of Radiology, 110 Donner, 3400 Spruce Street, Philadelphia, PA 19104 (United States)

    1997-12-01

    We have used computer simulations to compare two designs for a PET scanner dedicated to breast imaging with a whole-body PET scanner. The new designs combine high spatial resolution, high sensitivity, and good energy resolution to detect small, low-contrast masses. The detectors are position sensitive NaI(Tl) scintillators. The first design is a ring scanner surrounding the breast and the second consists of two planar detectors placed on opposite sides of the breast. We have employed standard performance measures to compare the different designs: contrast, percentage standard deviation of the background, and signal-to-noise ratios of reconstructed images. The results of the simulations show that both of the proposed designs have better lesion detectability than a whole-body scanner. The results also show that contrast is higher in the ring breast system but that the noise is lower in the planar breast system. Overall, the ring system yields images with the best signal-to-noise ratios, although the planar system offers practical advantages for imaging the breast and axilla. (author)

  19. Dedicated PET scanners for breast imaging.

    Science.gov (United States)

    Freifelder, R; Karp, J S

    1997-12-01

    We have used computer simulations to compare two designs for a PET scanner dedicated to breast imaging with a whole-body PET scanner. The new designs combine high spatial resolution, high sensitivity, and good energy resolution to detect small, low-contrast masses. The detectors are position sensitive NaI(Tl) scintillators. The first design is a ring scanner surrounding the breast and the second consists of two planar detectors placed on opposite sides of the breast. We have employed standard performance measures to compare the different designs: contrast, percentage standard deviation of the background, and signal-to-noise ratios of reconstructed images. The results of the simulations show that both of the proposed designs have better lesion detectability than a whole-body scanner. The results also show that contrast is higher in the ring breast system but that the noise is lower in the planar breast system. Overall, the ring system yields images with the best signal-to-noise ratios, although the planar system offers practical advantages for imaging the breast and axilla.

  20. Dedicated PET scanners for breast imaging

    Science.gov (United States)

    Freifelder, Richard; Karp, Joel S.

    1997-12-01

    We have used computer simulations to compare two designs for a PET scanner dedicated to breast imaging with a whole-body PET scanner. The new designs combine high spatial resolution, high sensitivity, and good energy resolution to detect small, low-contrast masses. The detectors are position sensitive NaI(Tl) scintillators. The first design is a ring scanner surrounding the breast and the second consists of two planar detectors placed on opposite sides of the breast. We have employed standard performance measures to compare the different designs: contrast, percentage standard deviation of the background, and signal-to-noise ratios of reconstructed images. The results of the simulations show that both of the proposed designs have better lesion detectability than a whole-body scanner. The results also show that contrast is higher in the ring breast system but that the noise is lower in the planar breast system. Overall, the ring system yields images with the best signal-to-noise ratios, although the planar system offers practical advantages for imaging the breast and axilla.

  1. The PS Booster Fast Wire Scanner

    CERN Document Server

    Burger, S; Priestnall, K; Raich, U

    2003-01-01

    The very tight emittance budget for LHC type beams makes precise emittance measurements in the injector complex a necessity. The PS machine uses 2 fast wire scanners per transverse plane for emittance measurement of the circulating beams. In order to ease comparison the same type of wire scanners have been newly installed in the upstream machine, the PS Booster, where each of the 4 rings is equipped with 2 wire scanners measuring the horizontal and vertical profiles. Those wire scanners use new and more modern control and readout electronics featuring dedicated intelligent motor movement controllers, which relieves the very stringent real time constraints due to the very high speed of 20m/s. In order to be able to measure primary beams at the very low injection energy of the Booster (50MeV) secondary emission currents from the wire can be measured as well as secondary particle flows at higher primary particle energies during and after acceleration. The solution adopted for the control of the devices is descri...

  2. submitter Dynamical Models of a Wire Scanner

    CERN Document Server

    Barjau, Ana; Dehning, Bernd

    2016-01-01

    The accuracy of the beam profile measurements achievable by the current wire scanners at CERN is limited by the vibrations of their mechanical parts. In particular, the vibrations of the carbon wire represent the major source of wire position uncertainty which limits the beam profile measurement accuracy. In the coming years, due to the Large Hadron Collider (LHC) luminosity upgrade, a wire traveling speed up to 20 $m s^{−1}$ and a position measurement accuracy of the order of 1 μm will be required. A new wire scanner design based on the understanding of the wire vibration origin is therefore needed. We present the models developed to understand the main causes of the wire vibrations observed in an existing wire scanner. The development and tuning of those models are based on measurements and tests performed on that CERN proton synchrotron (PS) scanner. The final model for the (wire + fork) system has six degrees-of-freedom (DOF). The wire equations contain three different excitation terms: inertia...

  3. Learning and Teaching with a Computer Scanner

    Science.gov (United States)

    Planinsic, G.; Gregorcic, B.; Etkina, E.

    2014-01-01

    This paper introduces the readers to simple inquiry-based activities (experiments with supporting questions) that one can do with a computer scanner to help students learn and apply the concepts of relative motion in 1 and 2D, vibrational motion and the Doppler effect. We also show how to use these activities to help students think like…

  4. Inter laboratory comparison of industrial CT scanners

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; Cantatore, Angela; De Chiffre, Leonardo

    2012-01-01

    In this report results from an intercomparison of industrial CT scanners are presented. Three audit items, similar to common industrial parts, were selected for circulation: a single polymer part with complex geometry (Item 1), a simple geometry part made of two polymers (Item 2) and a miniature...

  5. A PET scanner developed by CERN

    CERN Multimedia

    Laurent Guiraud

    1998-01-01

    This image shows a Position Emission Tomography (PET) scanner at the Hopital Cantonal Universitaire de Genève. Development of the multiwire proportional chamber at CERN in the mid-1970s was soon seen as a potential device for medical imaging. It is much more sensitive than previous devices and greatly reduced the dose of radiation received by the patient.

  6. Occurrence and characteristics of mutual interference between LIDAR scanners

    Science.gov (United States)

    Kim, Gunzung; Eom, Jeongsook; Park, Seonghyeon; Park, Yongwan

    2015-05-01

    The LIDAR scanner is at the heart of object detection of the self-driving car. Mutual interference between LIDAR scanners has not been regarded as a problem because the percentage of vehicles equipped with LIDAR scanners was very rare. With the growing number of autonomous vehicle equipped with LIDAR scanner operated close to each other at the same time, the LIDAR scanner may receive laser pulses from other LIDAR scanners. In this paper, three types of experiments and their results are shown, according to the arrangement of two LIDAR scanners. We will show the probability that any LIDAR scanner will interfere mutually by considering spatial and temporal overlaps. It will present some typical mutual interference scenario and report an analysis of the interference mechanism.

  7. Advanced Multispectral Scanner (AMS) study. [aircraft remote sensing

    Science.gov (United States)

    1978-01-01

    The status of aircraft multispectral scanner technology was accessed in order to develop preliminary design specifications for an advanced instrument to be used for remote sensing data collection by aircraft in the 1980 time frame. The system designed provides a no-moving parts multispectral scanning capability through the exploitation of linear array charge coupled device technology and advanced electronic signal processing techniques. Major advantages include: 10:1 V/H rate capability; 120 deg FOV at V/H = 0.25 rad/sec; 1 to 2 rad resolution; high sensitivity; large dynamic range capability; geometric fidelity; roll compensation; modularity; long life; and 24 channel data acquisition capability. The field flattening techniques of the optical design allow wide field view to be achieved at fast f/nos for both the long and short wavelength regions. The digital signal averaging technique permits maximization of signal to noise performance over the entire V/H rate range.

  8. Calibration and equivalency analysis of image plate scanners

    Energy Technology Data Exchange (ETDEWEB)

    Williams, G. Jackson, E-mail: williams270@llnl.gov; Maddox, Brian R.; Chen, Hui [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Kojima, Sadaoki [Institute of Laser Engineering, Osaka University, Yamada-oka, 2-6, Suita, Osaka 565-0871 (Japan); Millecchia, Matthew [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623 (United States)

    2014-11-15

    A universal procedure was developed to calibrate image plate scanners using radioisotope sources. Techniques to calibrate scanners and sources, as well as cross-calibrate scanner models, are described to convert image plate dosage into physical units. This allows for the direct comparison of quantitative data between any facility and scanner. An empirical relation was also derived to establish sensitivity response settings for arbitrary gain settings. In practice, these methods may be extended to any image plate scanning system.

  9. 21 CFR 892.1330 - Nuclear whole body scanner.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1330 Nuclear whole body scanner. (a) Identification. A nuclear whole body scanner is a device intended to measure and image the distribution of... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nuclear whole body scanner. 892.1330 Section...

  10. The use of mobile 3D scanners in maxillofacial surgery.

    Science.gov (United States)

    Peters, Florian; Möhlhenrich, Stephan Christian; Ayoub, Nassim; Goloborodko, Evgeny; Ghassemi, Alireza; Lethaus, Bernd; Hölzle, Frank; Modabber, Ali

    There are many possibilities for the use of three-dimensional (3D) scanners in maxillofacial surgery. This study aimed to investigate whether the bundling and syncing of two 3D scanners has advantages over single-scanner acquisition in terms of scan quality and the time required to scan an object. Therefore, the speed and precision of 3D data acquisition with one scanner versus two synced scanners was measured in 30 subjects. This was done by analyzing the results obtained by scanning test objects attached to the forehead and cheeks of the subjects. Statistical methods included the Student t test for paired samples. Single-scanner recording resulted in significantly lower mean error of measurement than synced recording with two scanners for length (P scanner method resulted in a significantly lowermean error of measurement than the two-scanner method for frontal/lower plane angles (P scanners resulted in a significant reduction of scanning time (P 3D scanner, the bundling of two 3D scanners resulted in faster scanning times but lower scan quality.

  11. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  12. Ghost signals in Allison emittance scanners

    Energy Technology Data Exchange (ETDEWEB)

    Stockli, Martin P.; /SNS Project, Oak Ridge /Tennessee U.; Leitner, M.; /LBL, Berkeley; Moehs, D.P.; /Fermilab; Keller, R.; /LBL, Berkeley; Welton, R.F.; /SNS Project, Oak

    2004-12-01

    For over 20 years, Allison scanners have been used to measure emittances of low-energy ion beams. We show that scanning large trajectory angles produces ghost signals caused by the sampled beamlet impacting on an electric deflection plate. The ghost signal strength is proportional to the amount of beam entering the scanner. Depending on the ions, and their velocity, the ghost signals can have the opposite or the same polarity as the main beam signals. The ghost signals cause significant errors in the emittance estimates because they appear at large trajectory angles. These ghost signals often go undetected because they partly overlap with the real signals, are mostly below the 1% level, and often hide in the noise. A simple deflection plate modification is shown to reduce the ghost signal strength by over 99%.

  13. Laser scanner 3D terrestri e mobile

    Directory of Open Access Journals (Sweden)

    Mario Ciamba

    2013-08-01

    Full Text Available Recentemente si è svolto a Roma un evento dimostrativo per informare, professionisti e ricercatori del settore inerente il rilievo strumentale, sulle recenti innovazioni che riguardano i laser scanner 3d. Il mercato della strumentazione dedicata al rilevamento architettonico e dell'ambiente, offre molte possibilità di scelta. Oggi i principali marchi producono strumenti sempre più efficienti ed ideati per ambiti di applicazione specifici, permettendo ai professionisti, la giusta scelta in termini di prestazioni ed economia.A demonstration event was recently held in Rome with the aim to inform professionals and researchers on recent innovations on instrumental survey related to the 3d laser scanner. The market of instrumentation for architectural survey offers many possibilitiesof choice. Today the major brands produce instruments that are more efficient and designed for specific areas of application, allowing the right choice in terms of performance and economy.

  14. Compact beamforming in medical ultrasound scanners

    DEFF Research Database (Denmark)

    Tomov, Borislav Gueorguiev

    2003-01-01

    This Ph.D. project was carried out at the Center for Fast Ultrasound Imaging, Technical University of Denmark, under the supervision of Prof. Jørgen Arendt Jensen, Assoc. Prof. Jens Sparsø and Prof. Erik Bruun. The goal was to investigate methods for efficient beamforming, which make it possible...... compact implementation of the beamformer compared to the case where conventional A/D conversion is used. The compact and economic beamforming is a key aspect in the progress of medical ultrasound imaging. Currently, 64 or 128 channels are widely used in scanners, top-of-the-range scanners have 256...... with an introduction into medical ultrasound, its basic principles, system evolution and its place among medical imaging techniques. Then, ultrasound acoustics is introduced, as a necessary base for understanding the concepts of acoustic focusing and beamforming, which follow. The necessary focusing information...

  15. Get Mobile – The Smartphone Brain Scanner

    DEFF Research Database (Denmark)

    Stahlhut, Carsten; Stopczynski, Arkadiusz; Petersen, Michael Kai

    This demonstration will provide live-interaction with a smartphone brain scanner consisting of a low-cost wireless 14-channel EEG headset (Emotiv Epoc) and a mobile device. With our system it is possible to perform real-time functional brain imaging on a smartphone device, including stimulus deli......) that are based on Linux operating systems. Thus our system runs on multiple platforms, including Maemo/MeeGo based smartphones, Android-based smartphones and tablet devices....

  16. Three-Dimensional Accuracy of Facial Scan for Facial Deformities in Clinics: A New Evaluation Method for Facial Scanner Accuracy.

    Science.gov (United States)

    Zhao, Yi-Jiao; Xiong, Yu-Xue; Wang, Yong

    2017-01-01

    In this study, the practical accuracy (PA) of optical facial scanners for facial deformity patients in oral clinic was evaluated. Ten patients with a variety of facial deformities from oral clinical were included in the study. For each patient, a three-dimensional (3D) face model was acquired, via a high-accuracy industrial "line-laser" scanner (Faro), as the reference model and two test models were obtained, via a "stereophotography" (3dMD) and a "structured light" facial scanner (FaceScan) separately. Registration based on the iterative closest point (ICP) algorithm was executed to overlap the test models to reference models, and "3D error" as a new measurement indicator calculated by reverse engineering software (Geomagic Studio) was used to evaluate the 3D global and partial (upper, middle, and lower parts of face) PA of each facial scanner. The respective 3D accuracy of stereophotography and structured light facial scanners obtained for facial deformities was 0.58±0.11 mm and 0.57±0.07 mm. The 3D accuracy of different facial partitions was inconsistent; the middle face had the best performance. Although the PA of two facial scanners was lower than their nominal accuracy (NA), they all met the requirement for oral clinic use.

  17. Three-Dimensional Accuracy of Facial Scan for Facial Deformities in Clinics: A New Evaluation Method for Facial Scanner Accuracy

    Science.gov (United States)

    Zhao, Yi-jiao; Xiong, Yu-xue; Wang, Yong

    2017-01-01

    In this study, the practical accuracy (PA) of optical facial scanners for facial deformity patients in oral clinic was evaluated. Ten patients with a variety of facial deformities from oral clinical were included in the study. For each patient, a three-dimensional (3D) face model was acquired, via a high-accuracy industrial “line-laser” scanner (Faro), as the reference model and two test models were obtained, via a “stereophotography” (3dMD) and a “structured light” facial scanner (FaceScan) separately. Registration based on the iterative closest point (ICP) algorithm was executed to overlap the test models to reference models, and “3D error” as a new measurement indicator calculated by reverse engineering software (Geomagic Studio) was used to evaluate the 3D global and partial (upper, middle, and lower parts of face) PA of each facial scanner. The respective 3D accuracy of stereophotography and structured light facial scanners obtained for facial deformities was 0.58±0.11 mm and 0.57±0.07 mm. The 3D accuracy of different facial partitions was inconsistent; the middle face had the best performance. Although the PA of two facial scanners was lower than their nominal accuracy (NA), they all met the requirement for oral clinic use. PMID:28056044

  18. MEMS Lens Scanners for Free-Space Optical Interconnects

    Science.gov (United States)

    2011-12-15

    89 Fig. 8.7. Matlab Simulink simulation of the optoelectronic PLL . (a) Shows the block diagram of the feedback loop. (b) Shows the linear...with a 20 kHz sample rate on a personal computer running the Labview real-time operating system. Fig. 4.12. Block diagram setup with... PLL ) circuit has been demonstrated by Satyan et. al, to linearize the frequency to current relationship, as shown in Fig. 8.6 [116]. Chapter 8

  19. Recent micro-CT scanner developments at UGCT

    Science.gov (United States)

    Dierick, Manuel; Van Loo, Denis; Masschaele, Bert; Van den Bulcke, Jan; Van Acker, Joris; Cnudde, Veerle; Van Hoorebeke, Luc

    2014-04-01

    This paper describes two X-ray micro-CT scanners which were recently developed to extend the experimental possibilities of microtomography research at the Centre for X-ray Tomography (www.ugct.ugent.be) of the Ghent University (Belgium). The first scanner, called Nanowood, is a wide-range CT scanner with two X-ray sources (160 kVmax) and two detectors, resolving features down to 0.4 μm in small samples, but allowing samples up to 35 cm to be scanned. This is a sample size range of 3 orders of magnitude, making this scanner well suited for imaging multi-scale materials such as wood, stone, etc. Besides the traditional cone-beam acquisition, Nanowood supports helical acquisition, and it can generate images with significant phase-contrast contributions. The second scanner, known as the Environmental micro-CT scanner (EMCT), is a gantry based micro-CT scanner with variable magnification for scanning objects which are not easy to rotate in a standard micro-CT scanner, for example because they are physically connected to external experimental hardware such as sensor wiring, tubing or others. This scanner resolves 5 μm features, covers a field-of-view of about 12 cm wide with an 80 cm vertical travel range. Both scanners will be extensively described and characterized, and their potential will be demonstrated with some key application results.

  20. Recent micro-CT scanner developments at UGCT

    Energy Technology Data Exchange (ETDEWEB)

    Dierick, Manuel, E-mail: Manuel.Dierick@UGent.be [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Van Loo, Denis, E-mail: info@XRE.be [XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Masschaele, Bert [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Van den Bulcke, Jan [UGCT-Woodlab-UGent, Department of Forest and Water Management, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent (Belgium); Van Acker, Joris, E-mail: Joris.VanAcker@UGent.be [UGCT-Woodlab-UGent, Department of Forest and Water Management, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent (Belgium); Cnudde, Veerle, E-mail: Veerle.Cnudde@UGent.be [UGCT-SGIG, Department of Geology and Soil Science, Faculty of Sciences, Ghent University, Krijgslaan 281, S8, 9000 Ghent (Belgium); Van Hoorebeke, Luc, E-mail: Luc.VanHoorebeke@UGent.be [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium)

    2014-04-01

    This paper describes two X-ray micro-CT scanners which were recently developed to extend the experimental possibilities of microtomography research at the Centre for X-ray Tomography ( (www.ugct.ugent.be)) of the Ghent University (Belgium). The first scanner, called Nanowood, is a wide-range CT scanner with two X-ray sources (160 kV{sub max}) and two detectors, resolving features down to 0.4 μm in small samples, but allowing samples up to 35 cm to be scanned. This is a sample size range of 3 orders of magnitude, making this scanner well suited for imaging multi-scale materials such as wood, stone, etc. Besides the traditional cone-beam acquisition, Nanowood supports helical acquisition, and it can generate images with significant phase-contrast contributions. The second scanner, known as the Environmental micro-CT scanner (EMCT), is a gantry based micro-CT scanner with variable magnification for scanning objects which are not easy to rotate in a standard micro-CT scanner, for example because they are physically connected to external experimental hardware such as sensor wiring, tubing or others. This scanner resolves 5 μm features, covers a field-of-view of about 12 cm wide with an 80 cm vertical travel range. Both scanners will be extensively described and characterized, and their potential will be demonstrated with some key application results.

  1. Ultra-compact imaging plate scanner module using a MEMS mirror and specially designed MPPC

    Science.gov (United States)

    Miyamoto, Yuichi; Sasaki, Kensuke; Takasaka, Masaomi; Fujimoto, Masatoshi; Yamamoto, Koei

    2017-02-01

    Computed radiography (CR), which is one of the most useful methods for dental imaging and nondestructive testing, uses a phosphor imaging plate (IP) because it is flexible, reusable, and inexpensive. Conventional IP scanners utilize a galvanometer or a polygon mirror as a scanning device and a photomultiplier as an optical sensor. Microelectromechanical systems (MEMS) technology currently provides silicon-based devices and has the potential to replace such discrete devices and sensors. Using these devices, we constructed an ultra-compact IP scanner. Our extremely compact plate scanner utilizes a module that is composed of a one-dimensional MEMS mirror and a long multi-pixel photon counter (MPPC) that is combined with a specially designed wavelength filter and a rod lens. The MEMS mirror, which is a non-resonant electromagnetic type, is 2.6 mm in diameter with a recommended optical scanning angle up to +/-15°. The CR's wide dynamic range is maintained using a newly developed MPPC. The MPPC is a sort of silicon photomultiplier and is a high-sensitivity photon-counting device. To achieve such a wide dynamic range, we developed a long MPPC that has over 10,000 pixels. For size reduction and high optical efficiency, we set the MPPC close to an IP across the rod lens. To prevent the MPPC from detecting excitation light, which is much more intense than photo-stimulated light, we produced a sharp-cut wavelength filter that has a wide angle (+/-60°) of tolerance. We evaluated our constructed scanner module through gray chart and resolution chart images.

  2. Positron Scanner for Locating Brain Tumors

    Science.gov (United States)

    Rankowitz, S.; Robertson, J. S.; Higinbotham, W. A.; Rosenblum, M. J.

    1962-03-01

    A system is described that makes use of positron emitting isotopes for locating brain tumors. This system inherently provides more information about the distribution of radioactivity in the head in less time than existing scanners which use one or two detectors. A stationary circular array of 32 scintillation detectors scans a horizontal layer of the head from many directions simultaneously. The data, consisting of the number of counts in all possible coincidence pairs, are coded and stored in the memory of a Two-Dimensional Pulse-Height Analyzer. A unique method of displaying and interpreting the data is described that enables rapid approximate analysis of complex source distribution patterns. (auth)

  3. A Cartographic Electron Beam Scanner Design Study.

    Science.gov (United States)

    1981-04-01

    0132 UNCLASSIFIED 6005 ETL-0257 NLEhmnnnnnununu lllhllIIhhlh EIIIIIIIIuuh hhhhhhhw-: o~"c ETL OVDFR U-C0EESE25SR7TINULIiE U..ARMYCOPSOFENINER ENINE ...17 2.3.4.4 Data Retrieval Process . . . . 2-21 2.3.5 Software .. ........... ... 2-25 2.4 Details of Scanner Experiments. 2-26 2.4.1 General...point processor and suitable interfaces were installed in the experimental Cartographic EBR System to provide complete compatibility with the software

  4. The Lick Observatory image-dissector scanner.

    Science.gov (United States)

    Robinson, L. B.; Wampler, E. J.

    1972-01-01

    A scanner that uses an image dissector to scan the output screen of an image tube has proven to be a sensitive and linear detector for faint astronomical spectra. The image-tube phosphor screen acts as a short-term storage element and allows the system to approach the performance of an ideal multichannel photon counter. Pulses resulting from individual photons, emitted from the output phosphor and detected by the image dissector, trigger an amplifier-discriminator and are counted in a 24-bit, 4096-word circulating memory. Aspects of system performance are discussed, giving attention to linearity, dynamic range, sensitivity, stability, and scattered light properties.

  5. Circumference estimation using 3D-whole body scanners and shadow scanner

    NARCIS (Netherlands)

    Daanen, H.A.M.

    1998-01-01

    Clothing designers and manufacturers use traditional body dimensions as their basis. When 3D-whole body scanners are introduced to determine the body dimensions, a conversion has to be made, since scan determined circumference measures are slightly larger than the traditional values. This pilot stud

  6. Antenna Near-Field Probe Station Scanner

    Science.gov (United States)

    Zaman, Afroz J. (Inventor); Lee, Richard Q. (Inventor); Darby, William G. (Inventor); Barr, Philip J. (Inventor); Lambert, Kevin M (Inventor); Miranda, Felix A. (Inventor)

    2011-01-01

    A miniaturized antenna system is characterized non-destructively through the use of a scanner that measures its near-field radiated power performance. When taking measurements, the scanner can be moved linearly along the x, y and z axis, as well as rotationally relative to the antenna. The data obtained from the characterization are processed to determine the far-field properties of the system and to optimize the system. Each antenna is excited using a probe station system while a scanning probe scans the space above the antenna to measure the near field signals. Upon completion of the scan, the near-field patterns are transformed into far-field patterns. Along with taking data, this system also allows for extensive graphing and analysis of both the near-field and far-field data. The details of the probe station as well as the procedures for setting up a test, conducting a test, and analyzing the resulting data are also described.

  7. Recent micro-CT scanner developments at UGCT

    OpenAIRE

    Dierick, Manuel; Van Loo, Denis; Masschaele, Bert; Boone, Matthieu; Van Hoorebeke, Luc; Cnudde, Veerle

    2013-01-01

    UGCT is a user facility for multidisciplinary micro-CT research. The scanners at UGCT are custom designed and built by the Radiation Physics research group (UGent). This paper describes the two latest scanners that were developed in collaboration with XRE: HECTOR, a high energy micro-CT scanner, and EMCT, a gantry based micro-CT scanner with variable magnification. HECTOR is a 240 kV 280 W system with a nominal resolution of 4 micrometer. A 40x40 cm² flat panel detector which can be tiled res...

  8. Was the Scanner Calibration Slide used for its intended purpose?

    Science.gov (United States)

    2011-01-01

    In the article, Scanner calibration revisited, BMC Bioinformatics 2010, 11:361, Dr. Pozhitkov used the Scanner Calibration Slide, a key product of Full Moon BioSystems to generate data in his study of microarray scanner PMT response and proposed a mathematic model for PMT response [1]. In the end, the author concluded that "Full Moon BioSystems calibration slides are inadequate for performing calibration," and recommended "against using these slides." We found these conclusions are seriously flawed and misleading, and his recommendation against using the Scanner Calibration Slide was not properly supported. PMID:21510874

  9. Was the Scanner Calibration Slide used for its intended purpose?

    Directory of Open Access Journals (Sweden)

    Zong Yaping

    2011-04-01

    Full Text Available Abstract In the article, Scanner calibration revisited, BMC Bioinformatics 2010, 11:361, Dr. Pozhitkov used the Scanner Calibration Slide, a key product of Full Moon BioSystems to generate data in his study of microarray scanner PMT response and proposed a mathematic model for PMT response 1. In the end, the author concluded that "Full Moon BioSystems calibration slides are inadequate for performing calibration," and recommended "against using these slides." We found these conclusions are seriously flawed and misleading, and his recommendation against using the Scanner Calibration Slide was not properly supported.

  10. Using mid-range laser scanners to digitize cultural-heritage sites.

    Science.gov (United States)

    Spring, Adam P; Peters, Caradoc; Minns, Tom

    2010-01-01

    Here, we explore new, more accessible ways of modeling 3D data sets that both professionals and amateurs can employ in areas such as architecture, forensics, geotechnics, cultural heritage, and even hobbyist modeling. To support our arguments, we present images from a recent case study in digital preservation of cultural heritage using a mid-range laser scanner. Our appreciation of the increasing variety of methods for capturing 3D spatial data inspired our research. Available methods include photogrammetry, airborne lidar, sonar, total stations (a combined electronic and optical survey instrument), and midand close-range scanning.1 They all can produce point clouds of varying density. In our case study, the point cloud produced by a mid-range scanner demonstrates how open source software can make modeling and disseminating data easier. Normally, researchers would model this data using expensive specialized software, and the data wouldn't extend beyond the laser-scanning community.

  11. Identification of scanner models by comparison of scanned hologram images.

    Science.gov (United States)

    Sugawara, Shigeru

    2014-08-01

    A method to identify scanner models that had been used to forge low-level counterfeit currencies was proposed in this study. The method identified a scanner model by characterizing differences between hologram images that exist in low-level counterfeit currencies. Twenty scanners of 18 different models were used to make samples of hologram images used in this study. The method was divided into two steps: identification of capturing conditions and identification of the scanner model. The first proposed protocol used correlations of spatial distribution of brightness to identify capturing conditions. A second proposed protocol used correlations of color distributions to identify a scanner model. The effectiveness of the protocols was demonstrated with numerical methods and sample images. The preliminary study revealed that it is necessary to consider the orientation of the holograms when the scanner models were identified, but 180° rotations can be ignored. Moreover, it is necessary to consider position in the main scanning direction of the bed for charged-coupled-device scanners. The demonstration showed that the first protocol could correctly identify the capturing conditions of almost all hologram images. However, one image could not be identified correctly; the protocol could distinguish images captured by charged-coupled-device scanners and those captured by contact image sensor scanners if the hologram was placed on the right or left edge of the scanner bed, but could not distinguish them if the hologram was placed on the inside. The demonstration also showed that the second protocol could correctly identify scanner models of all hologram images.

  12. A scanning probe microscope for magnetoresistive cantilevers utilizing a nested scanner design for large-area scans

    Directory of Open Access Journals (Sweden)

    Tobias Meier

    2015-02-01

    Full Text Available We describe an atomic force microscope (AFM for the characterization of self-sensing tunneling magnetoresistive (TMR cantilevers. Furthermore, we achieve a large scan-range with a nested scanner design of two independent piezo scanners: a small high resolution scanner with a scan range of 5 × 5 × 5 μm3 is mounted on a large-area scanner with a scan range of 800 × 800 × 35 μm3. In order to characterize TMR sensors on AFM cantilevers as deflection sensors, the AFM is equipped with a laser beam deflection setup to measure the deflection of the cantilevers independently. The instrument is based on a commercial AFM controller and capable to perform large-area scanning directly without stitching of images. Images obtained on different samples such as calibration standard, optical grating, EPROM chip, self-assembled monolayers and atomic step-edges of gold demonstrate the high stability of the nested scanner design and the performance of self-sensing TMR cantilevers.

  13. Development of scintillation materials for PET scanners

    CERN Document Server

    Korzhik, Mikhail; Annenkov, Alexander N; Borissevitch, Andrei; Dossovitski, Alexei; Missevitch, Oleg; Lecoq, Paul

    2007-01-01

    The growing demand on PET methodology for a variety of applications ranging from clinical use to fundamental studies triggers research and development of PET scanners providing better spatial resolution and sensitivity. These efforts are primarily focused on the development of advanced PET detector solutions and on the developments of new scintillation materials as well. However Lu containing scintillation materials introduced in the last century such as LSO, LYSO, LuAP, LuYAP crystals still remain the best PET species in spite of the recent developments of bright, fast but relatively low density lanthanum bromide scintillators. At the same time Lu based materials have several drawbacks which are high temperature of crystallization and relatively high cost compared to alkali-halide scintillation materials. Here we describe recent results in the development of new scintillation materials for PET application.

  14. Gigapixel microscopy using a flatbed scanner

    CERN Document Server

    Zheng, Guoan; Yang, Changhuei

    2012-01-01

    Microscopy imaging systems with a very wide field-of-view (FOV) are highly sought in biomedical applications. In this paper, we report a wide FOV microscopy imaging system that uses a low-cost scanner and a closed-circuit-television (CCTV) lens. We show that such an imaging system is capable to capture a 10 mm * 7.5 mm FOV image with 0.77 micron resolution, resulting in 0.54 gigapixels (109 pixels) across the entire image (26400 pixels * 20400 pixels). The resolution and field curve of the proposed system were characterized by imaging a USAF resolution target and a hole-array target. A 1.6 gigapixel microscopy image (0.54 gigapixel with 3 colors) of a pathology slide was acquired by using such a system for application demonstration.

  15. Vision Assisted Laser Scanner Navigation for Autonomous Robots

    DEFF Research Database (Denmark)

    Andersen, Jens Christian; Andersen, Nils Axel; Ravn, Ole

    2008-01-01

    This paper describes a navigation method based on road detection using both a laser scanner and a vision sensor. The method is to classify the surface in front of the robot into traversable segments (road) and obstacles using the laser scanner, this classifies the area just in front of the robot ...

  16. Convenient integrating sphere scanner for accurate luminous flux measurements

    Science.gov (United States)

    Winter, S.; Lindemann, M.; Jordan, W.; Binder, U.; Anokhin, M.

    2009-08-01

    Measurement results and applications of a recently developed device for the measurement of the spatial uniformity of integrating spheres are presented. Due to the complexity of their implementation, sphere scanners are mainly used by national metrology institutes to increase the accuracy of relative and absolute luminous flux measurements (Ohno et al 1997 J. IES 26 107-14, Ohno and Daubach 2001 J. IES 30 105-15, Ohno 1998 Metrologia 35 473-8, Hovila et al 2004 Metrologia 41 407-13). The major drawback of traditional scanners for integrating spheres is the necessity of a complex and time-consuming sphere modification, as the lamp holder has to be replaced by a new scanner holder with additional cables for power supply and for communication with the stepping motor control unit (Ohno et al 1997 J. IES 26 107-14). Therefore, with traditional scanners the relative spatial sphere responsivity already changes due to the installation of a special scanner holder. The new scanner simply substitutes the lamp under test: it can be screwed into an E27 lamp socket, as it needs only two electrical contacts. Two wires are simultaneously used for the power supply of the stepping motor control unit, the scanner light source (LED) and for the signal transmission of commands and results. The benefits of scanner-assisted measurements are shown for spotlight lamp calibrations.

  17. Quantitative Assay for Starch by Colorimetry Using a Desktop Scanner

    Science.gov (United States)

    Matthews, Kurt R.; Landmark, James D.; Stickle, Douglas F.

    2004-01-01

    The procedure to produce standard curve for starch concentration measurement by image analysis using a color scanner and computer for data acquisition and color analysis is described. Color analysis is performed by a Visual Basic program that measures red, green, and blue (RGB) color intensities for pixels within the scanner image.

  18. Thermionic scanner pinpoints work function of emitter surfaces

    Science.gov (United States)

    Rasor, N. S.

    1966-01-01

    In the electron tube testing, a thermionic scanner makes accurate spatial resolution measurements of the metallic surface work functions of emitters. The scanner determines the emitter function and its local departures from the mean value on a point-by-point basis for display on an oscilloscope.

  19. Flux profile scanners for scattered high-energy electrons

    Science.gov (United States)

    Hicks, R. S.; Decowski, P.; Arroyo, C.; Breuer, M.; Celli, J.; Chudakov, E.; Kumar, K. S.; Olson, M.; Peterson, G. A.; Pope, K.; Ricci, J.; Savage, J.; Souder, P. A.

    2005-11-01

    The paper describes the design and performance of flux integrating Cherenkov scanners with air-core reflecting light guides used in a high-energy, high-flux electron scattering experiment at the Stanford Linear Accelerator Center. The scanners were highly radiation resistant and provided a good signal to background ratio leading to very good spatial resolution of the scattered electron flux profile scans.

  20. A ’Millipede’ scanner model - Energy consumption and performance

    NARCIS (Netherlands)

    Engelen, Johan B.C.; Khatib, Mohammed G.

    2008-01-01

    This short report (1) describes an energy model for the seek and read/write operations in a mass-balanced Y-scanner for parallel-probe storage by IBM [1] and (2) updates the settings of the MEMS model in DiskSim with recent published figures from this XY-scanner. To speedup system simulations, a str

  1. Study of PET scanner designs using clinical metrics to optimize the scanner axial FOV and crystal thickness

    Science.gov (United States)

    Surti, S.; Werner, M. E.; Karp, J. S.

    2013-06-01

    The aim of this study is to understand the trade-off between crystal thickness and scanner axial field-of-view FOV (AFOV) for clinical PET imaging. Clinical scanner design has evolved towards 20-25 mm thick crystals and 16-22 cm long scanner AFOV, as well as time-of-flight (TOF) imaging. While Monte Carlo studies demonstrate that longer AFOV and thicker crystals will lead to higher scanner sensitivity, cost has prohibited the building of commercial scanners with >22 cm AFOV. In this study, we performed a series of system simulations to optimize the use of a given amount of crystal material by evaluating the impact on system sensitivity and noise equivalent counts (NEC), as well as image quality in terms of lesion detectability. We evaluated two crystal types (LSO and LaBr3) and fixed the total crystal volume used for each type (8.2 L of LSO and 17.1 L of LaBr3) while varying the crystal thickness and scanner AFOV. In addition, all imaging times were normalized so that the total scan time needed to scan a 100 cm long object with multiple bed positions was kept constant. Our results show that the highest NEC cm-1 in a 35 cm diameter ×70 cm long line source cylinder is achieved for an LSO scanner with 10 mm long crystals and AFOV of 36 cm, while for LaBr3 scanners, the highest NEC cm-1 is obtained with 20 mm long crystals and an AFOV of 38 cm. Lesion phantom simulations show that the best lesion detection performance is achieved in scanners with long AFOV (≥36 cm) and using thin crystals (≤10 mm of LSO and ≤20 mm of LaBr3). This is due to a combination of improved NEC, as well as improved lesion contrast estimation due to better spatial resolution in thinner crystals. Alternatively, for lesion detection performance similar to that achieved in standard clinical scanner designs, the long AFOV scanners can be used to reduce the total scan time without increasing the amount of crystal used in the scanner. In addition, for LaBr3 based scanners, the reduced lesion

  2. The Surface Wave Scattering-Microwave Scanner (SWS-MS)

    Science.gov (United States)

    Geffrin, Jean-Michel; Chamtouri, Maha; Merchiers, Olivier; Tortel, Hervé; Litman, Amélie; Bailly, Jean-Sébastien; Lacroix, Bernard; Francoeur, Mathieu; Vaillon, Rodolphe

    2016-01-01

    The Surface Wave Scattering-Microwave Scanner (SWS-MS) is a device that allows the measurement of the electromagnetic fields scattered by objects totally or partially submerged in surface waves. No probe is used to illuminate the sample, nor to guide or scatter the local evanescent waves. Surface waves are generated by total internal reflection and the amplitude and phase of the fields scattered by the samples are measured directly, both in the far-field and the near-field regions. The device's principles and their practical implementation are described in details. The surface wave generator is assessed by measuring the spatial distribution of the electric field above the surface. Drift correction and the calibration method for far-field measurements are explained. Comparison of both far-field and near-field measurements against simulation data shows that the device provides accurate results. This work suggests that the SWS-MS can be used for producing experimental reference data, for supporting a better understanding of surface wave scattering, for assisting in the design of near-field optical or infrared systems thanks to the scale invariance rule in electrodynamics, and for performing nondestructive control of defects in materials.

  3. On the spectral quality of scanner illumination with LEDs

    Science.gov (United States)

    Cui, Chengwu

    2013-01-01

    Document scanner illumination has evolved along with general illumination technologies. LEDs have become more and more popular as the illumination sources for document scanning. LED technologies provide a wide range of choices both in terms of structural design and spectral compositions. In this report, we examine some popular LED technologies used for document scanner. We evaluate the color rendering performance of scanner models with different illumination technologies by examining their rendering of the Macbeth ColorChecker™ in sRGB. We found that more phosphors in phosphor conversion types of white LEDs may not be necessarily advantageous in terms of scanner color rendering performance. Also CIS type of scanner may be sensitive to the peak wavelength shift and can be particularly problematic when the peaks are out of certain range.

  4. Ultra-Miniature Lidar Scanner for Launch Range Data Collection

    Science.gov (United States)

    Geng, Jason

    2012-01-01

    The most critical component in lidar is its laser scanner, which delivers pulsed or CW laser to target with desirable field of view (FOV). Most existing lidars use a rotating or oscillating mirror for scanning, resulting in several drawbacks. A lidar scanning technology was developed that could achieve very high scanning speed, with an ultra-miniature size and much lighter weight. This technology promises at least a 10x performance improvement in these areas over existing lidar scanners. Features of the proposed ultra-miniature lidar scanner include the ability to make the entire scanner <2 mm in diameter; very high scanning speed (e.g. 5 - 20 kHz, in contrast to several hundred Hz in existing scanners); structure design to meet stringent requirements on size, weight, power, and compactness for various applications; and the scanning speed and FOV can be altered for obtaining high image resolutions of targeted areas and for diversified uses.

  5. A new correction method serving to eliminate the parabola effect of flatbed scanners used in radiochromic film dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Poppinga, D., E-mail: daniela.poppinga@uni-oldenburg.de; Schoenfeld, A. A.; Poppe, B. [Medical Radiation Physics, Carl v. Ossietzky University, Oldenburg 26127, Germany and Department for Radiation Oncology, Pius Hospital, Oldenburg 26121 (Germany); Doerner, K. J. [Radiotherapy Department, General Hospital, Celle 29223 (Germany); Blanck, O. [CyberKnife Center Northern Germany, Güstrow 18273, Germany and Department for Radiation Oncology, University Clinic Schleswig-Holstein, Lübeck 23562 (Germany); Harder, D. [Medical Physics and Biophysics, Georg-August-University, Göttingen 37073 (Germany)

    2014-02-15

    Purpose: The purpose of this study is the correction of the lateral scanner artifact, i.e., the effect that, on a large homogeneously exposed EBT3 film, a flatbed scanner measures different optical densities at different positions along thex axis, the axis parallel to the elongated light source. At constant dose, the measured optical densitiy profiles along this axis have a parabolic shape with significant dose dependent curvature. Therefore, the effect is shortly called the parabola effect. The objective of the algorithm developed in this study is to correct for the parabola effect. Any optical density measured at given position x is transformed into the equivalent optical density c at the apex of the parabola and then converted into the corresponding dose via the calibration of c versus dose. Methods: For the present study EBT3 films and an Epson 10000XL scanner including transparency unit were used for the analysis of the parabola effect. The films were irradiated with 6 MV photons from an Elekta Synergy accelerator in a RW3 slab phantom. In order to quantify the effect, ten film pieces with doses graded from 0 to 20.9 Gy were sequentially scanned at eight positions along thex axis and at six positions along the z axis (the movement direction of the light source) both for the portrait and landscape film orientations. In order to test the effectiveness of the new correction algorithm, the dose profiles of an open square field and an IMRT plan were measured by EBT3 films and compared with ionization chamber and ionization chamber array measurement. Results: The parabola effect has been numerically studied over the whole measuring field of the Epson 10000XL scanner for doses up to 20.9 Gy and for both film orientations. The presented algorithm transforms any optical density at positionx into the equivalent optical density that would be measured at the same dose at the apex of the parabola. This correction method has been validated up to doses of 5.2 Gy all over the

  6. A new correction method serving to eliminate the parabola effect of flatbed scanners used in radiochromic film dosimetry.

    Science.gov (United States)

    Poppinga, D; Schoenfeld, A A; Doerner, K J; Blanck, O; Harder, D; Poppe, B

    2014-02-01

    The purpose of this study is the correction of the lateral scanner artifact, i.e., the effect that, on a large homogeneously exposed EBT3 film, a flatbed scanner measures different optical densities at different positions along the x axis, the axis parallel to the elongated light source. At constant dose, the measured optical density profiles along this axis have a parabolic shape with significant dose dependent curvature. Therefore, the effect is shortly called the parabola effect. The objective of the algorithm developed in this study is to correct for the parabola effect. Any optical density measured at given position x is transformed into the equivalent optical density c at the apex of the parabola and then converted into the corresponding dose via the calibration of c versus dose. For the present study EBT3 films and an Epson 10000XL scanner including transparency unit were used for the analysis of the parabola effect. The films were irradiated with 6 MV photons from an Elekta Synergy accelerator in a RW3 slab phantom. In order to quantify the effect, ten film pieces with doses graded from 0 to 20.9 Gy were sequentially scanned at eight positions along the x axis and at six positions along the z axis (the movement direction of the light source) both for the portrait and landscape film orientations. In order to test the effectiveness of the new correction algorithm, the dose profiles of an open square field and an IMRT plan were measured by EBT3 films and compared with ionization chamber and ionization chamber array measurement. The parabola effect has been numerically studied over the whole measuring field of the Epson 10000XL scanner for doses up to 20.9 Gy and for both film orientations. The presented algorithm transforms any optical density at position x into the equivalent optical density that would be measured at the same dose at the apex of the parabola. This correction method has been validated up to doses of 5.2 Gy all over the scanner bed with 2D dose

  7. Flying spot laser triangulation scanner using lateral synchronization for surface profile precision measurement.

    Science.gov (United States)

    Zhang, Hanlin; Ren, Yongjie; Liu, Changjie; Zhu, Jigui

    2014-07-10

    High-speed surface profile measurement with high precision is crucial for target inspection and quality control. In this study, a laser scanner based on a single point laser triangulation displacement sensor and a high-speed rotating polygon mirror is proposed. The autosynchronized scanning scheme is introduced to alleviate the trade-off between the field of view and the range precision, which is the inherent deficiency of the conventional triangulation. The lateral synchronized flying spot technology has excellent characteristics, such as programmable and larger field of view, high immunity to ambient light or secondary reflections, high optical signal-to-noise ratio, and minimum shadow effect. Owing to automatic point-to-point laser power control, high accuracy and superior data quality are possible when measuring objects featuring varying surface characteristics even in demanding applications. The proposed laser triangulation scanner is validated using a laboratory-built prototype and practical considerations for design and implementation of the system are described, including speckle noise reduction method and real-time signal processing. A method for rapid and accurate calibration of the laser triangulation scanner using lookup tables is also devised, and the system calibration accuracy is generally smaller than ±0.025  mm. Experimental results are presented and show a broad application prospect for fast surface profile precision measurement.

  8. Foveated scanning: dynamic monodimensional enlargement of resolved field of view in lenses of scanner systems.

    Science.gov (United States)

    Javaherian, Farhang; Rashidian, Bizhan

    2016-09-10

    An inconsistency between the circular symmetric geometry of conventional optical imagers and the geometry of long linear sensors used in today's line-scan cameras results in suboptimal separate design of optics and electronics of scanner systems. Based on the method of foveated optical imaging, a technique named foveated scanning (FS) is proposed in this paper. The FS technique is employed to enlarge the one-dimensional resolved field of view (RFOV) of conventional lenses and permits optimized performance on a line-of-interest in the image plane where the optoelectronic sensor is located. The achieved enlargement of RFOV is verified on a proof-of-concept basic telephoto lens. Both modulation transfer function analysis and the imaging simulation of a standard target have been performed. Results show a twofold increase in RFOV by this technique.

  9. [Innovation and Future Technologies for PET Scanners].

    Science.gov (United States)

    Yamaya, Taiga

    2015-01-01

    Positron emission tomography (PET) plays important roles in cancer diagnosis, neuroimaging and molecular imaging research; but potential points remain for which big improvements could be made, including spatial resolution, sensitivity and manufacturing costs. Higher spatial resolution is essential to enable earlier diagnosis, and improved sensitivity results in reduced radiation exposure and shortened measurement time. Therefore, research on next generation PET technologies remains a hot topic worldwide. In this paper, innovation and future technologies for the next generation PET scanners, such as time-of-flight measurement and simultaneous PET/MRI measurement, are described. Among them, depth-of-interaction (DOI) measurement in the radiation sensor will be a key technology to get any significant improvement in sensitivity while maintaining high spatial resolution. DOI measurement also has a potential to expand PET application fields because it allows for more flexible detector arrangement. As an example, the world's first, open-type PET geometry "OpenPET", which is expected to lead to PET imaging during treatment, is under development. The DOI detector itself continues to evolve with the help of recently developed semiconductor photodetectors, often referred to as silicon photomultipliers.

  10. Fast and High Accuracy Wire Scanner

    CERN Document Server

    Koujili, M; Koopman, J; Ramos, D; Sapinski, M; De Freitas, J; Ait Amira, Y; Djerdir, A

    2009-01-01

    Scanning of a high intensity particle beam imposes challenging requirements on a Wire Scanner system. It is expected to reach a scanning speed of 20 m.s-1 with a position accuracy of the order of 1 μm. In addition a timing accuracy better than 1 millisecond is needed. The adopted solution consists of a fork holding a wire rotating by a maximum of 200°. Fork, rotor and angular position sensor are mounted on the same axis and located in a chamber connected to the beam vacuum. The requirements imply the design of a system with extremely low vibration, vacuum compatibility, radiation and temperature tolerance. The adopted solution consists of a rotary brushless synchronous motor with the permanent magnet rotor installed inside of the vacuum chamber and the stator installed outside. The accurate position sensor will be mounted on the rotary shaft inside of the vacuum chamber, has to resist a bake-out temperature of 200°C and ionizing radiation up to a dozen of kGy/year. A digital feedback controller allows maxi...

  11. From Beamline to Scanner with 225Ac

    Science.gov (United States)

    Robertson, Andrew K. H.; Ramogida, Caterina F.; Kunz, Peter; Rodriguez-Rodriguez, Cristina; Schaffer, Paul; Sossi, Vesna

    2016-09-01

    Due to the high linear energy transfer and short range of alpha-radiation, targeted radiation therapy using alpha-emitting pharmaceuticals that successfully target small disease clusters will kill target cells with limited harm to healthy tissue, potentially treating the most aggressive forms of cancer. As the parent of a decay chain with four alpha- and two beta-decays, 225Ac is a promising candidate for such a treatment. However, this requires retention of the entire decay chain at the target site, preventing the creation of freely circulating alpha-emitters that reduce therapeutic effect and increase toxicity to non-target tissues. Two major challenges to 225Ac pharmaceutical development exist: insufficient global supply, and the difficulty of preventing toxicity by retaining the entire decay chain at the target site. While TRIUMF works towards large-scale (C i amounts) production of 225Ac, we already use our Isotope Separation On-Line facility to provide small (overview of this research program and the journey of 225Ac from the beamline to the scanner. This research is funded by the Natural Sciences and Engineering Research Council of Canada.

  12. The origin of the flatbed scanner artifacts in radiochromic film dosimetry-key experiments and theoretical descriptions.

    Science.gov (United States)

    Schoenfeld, Andreas A; Wieker, Soeren; Harder, Dietrich; Poppe, Bjoern

    2016-11-07

    The optical origin of the lateral response and orientation artifacts, which occur when using EBT3 and EBT-XD radiochromic films together with flatbed scanners, has been reinvestigated by experimental and theoretical means. The common feature of these artifacts is the well-known parabolic increase in the optical density OD(x)  =  -log10 I(x)/I 0(x) versus offset x from the scanner midline (Poppinga et al 2014 Med. Phys. 41 021707). This holds for landscape and portrait orientations as well as for the three color channels. Dose-independent optical subjects, such as neutral density filters, linear polarizers, the EBT polyester foil and diffusive glass, also present the parabolic lateral artifact when scanned with a flatbed scanner. The curvature parameter c of the parabola function OD(x)  =  c 0  +  cx (2) is found to be a linear function of the dose, the parameters of which are influenced by the film orientation and film type, EBT3 or EBT-XD. The ubiquitous parabolic shape of function OD(x) is attributed (a) to the optical path-length effect (van Battum et al 2016 Phys. Med. Biol. 61 625-49), due to the increasing obliquity of the optical scanner light associated with increasing offset x from the scanner midline, and (b) and (c) to the partial polarization and scattering of the light leaving the film, which affect the ratio [Formula: see text], thus making OD(x) increase with x (2). The orientation effect results from the changes of effects (b) and (c) associated with turning the film position, and thereby the orientation of the polymer structure of the sensitive film layer. In a comparison of experimental results obtained with selected optical subjects, the relative weights of the contributions of the optical path-length effect and the polarization and scattering of light leaving the films to the lateral response artifact have been estimated to be of the same order of magnitude. Mathematical models of these causes for the parabolic shape of

  13. The origin of the flatbed scanner artifacts in radiochromic film dosimetry—key experiments and theoretical descriptions

    Science.gov (United States)

    Schoenfeld, Andreas A.; Wieker, Soeren; Harder, Dietrich; Poppe, Bjoern

    2016-11-01

    The optical origin of the lateral response and orientation artifacts, which occur when using EBT3 and EBT-XD radiochromic films together with flatbed scanners, has been reinvestigated by experimental and theoretical means. The common feature of these artifacts is the well-known parabolic increase in the optical density OD(x)  =  -log10 I(x)/I 0(x) versus offset x from the scanner midline (Poppinga et al 2014 Med. Phys. 41 021707). This holds for landscape and portrait orientations as well as for the three color channels. Dose-independent optical subjects, such as neutral density filters, linear polarizers, the EBT polyester foil and diffusive glass, also present the parabolic lateral artifact when scanned with a flatbed scanner. The curvature parameter c of the parabola function OD(x)  =  c 0  +  cx 2 is found to be a linear function of the dose, the parameters of which are influenced by the film orientation and film type, EBT3 or EBT-XD. The ubiquitous parabolic shape of function OD(x) is attributed (a) to the optical path-length effect (van Battum et al 2016 Phys. Med. Biol. 61 625-49), due to the increasing obliquity of the optical scanner light associated with increasing offset x from the scanner midline, and (b) and (c) to the partial polarization and scattering of the light leaving the film, which affect the ratio ~I(x)/{{I}0}(x) , thus making OD(x) increase with x 2. The orientation effect results from the changes of effects (b) and (c) associated with turning the film position, and thereby the orientation of the polymer structure of the sensitive film layer. In a comparison of experimental results obtained with selected optical subjects, the relative weights of the contributions of the optical path-length effect and the polarization and scattering of light leaving the films to the lateral response artifact have been estimated to be of the same order of magnitude. Mathematical models of these causes for the parabolic shape of function

  14. 21 CFR 892.1300 - Nuclear rectilinear scanner.

    Science.gov (United States)

    2010-04-01

    ...) Identification. A nuclear rectilinear scanner is a device intended to image the distribution of radionuclides in the body by means of a detector (or detectors) whose position moves in two directions with respect...

  15. Whole-body 3D scanner and scan data report

    Science.gov (United States)

    Addleman, Stephen R.

    1997-03-01

    With the first whole-body 3D scanner now available the next adventure confronting the user is what to do with all of the data. While the system was built for anthropologists, it has created interest among users from a wide variety of fields. Users with applications in the fields of anthropology, costume design, garment design, entertainment, VR and gaming have a need for the data in formats unique to their fields. Data from the scanner is being converted to solid models for art and design and NURBS for computer graphics applications. Motion capture has made scan data move and dance. The scanner has created a need for advanced application software just as other scanners have in the past.

  16. Landsat 1-5 Multispectral Scanner V1

    Data.gov (United States)

    National Aeronautics and Space Administration — Abstract: The Landsat Multispectral Scanner (MSS) was a sensor onboard Landsats 1 through 5 and acquired images of the Earth nearly continuously from July 1972 to...

  17. APLIKASI INFO HALAL MENGGUNAKAN BARCODE SCANNER UNTUK SMARTPHONE ANDROID

    National Research Council Canada - National Science Library

    Beki Subeki; M Rahmat Jauhari

    2016-01-01

    ... to obtain the correct information about the halal status of products bought. The use of barcode scanners halal product information using the mobile platform is effective and useful for the public to find out information on a product...

  18. Building a 3D Computed Tomography Scanner From Surplus Parts.

    Science.gov (United States)

    Haidekker, Mark A

    2014-01-01

    Computed tomography (CT) scanners are expensive imaging devices, often out of reach for small research groups. Designing and building a CT scanner from modular components is possible, and this article demonstrates that realization of a CT scanner from components is surprisingly easy. However, the high costs of a modular X-ray source and detector limit the overall cost savings. In this article, the possibility of building a CT scanner with available surplus X-ray parts is discussed, and a practical device is described that incurred costs of less than $16,000. The image quality of this device is comparable with commercial devices. The disadvantage is that design constraints imposed by the available components lead to slow scan speeds and a resolution of 0.5 mm. Despite these limitations, a device such as this is attractive for imaging studies in the biological and biomedical sciences, as well as for advancing CT technology itself.

  19. Computer vision and laser scanner road environment perception

    OpenAIRE

    García, Fernando; Ponz Vila, Aurelio; Martín Gómez, David; Escalera, Arturo de la; Armingol, José M.

    2014-01-01

    Data fusion procedure is presented to enhance classical Advanced Driver Assistance Systems (ADAS). The novel vehicle safety approach, combines two classical sensors: computer vision and laser scanner. Laser scanner algorithm performs detection of vehicles and pedestrians based on pattern matching algorithms. Computer vision approach is based on Haar-Like features for vehicles and Histogram of Oriented Gradients (HOG) features for pedestrians. The high level fusion procedure uses Kalman Filter...

  20. Determining organ doses from computed tomography scanners using cadaveric subjects

    Science.gov (United States)

    Griglock, Thomas M.

    The use of computed tomographic (CT) imaging has increased greatly since its inception in 1972. Technological advances have increased both the applicability of CT exams for common health problems as well as the radiation doses used to perform these exams. The increased radiation exposures have garnered much attention in the media and government agencies, and have brought about numerous attempts to quantify the amount of radiation received by patients. While the overwhelming majority of these attempts have focused on creating models of the human body (physical or computational), this research project sought to directly measure the radiation inside an actual human being. Three female cadaveric subjects of varying sizes were used to represent live patients. Optically-stimulated luminescent (OSL) dosimeters were used to measure the radiation doses. A dosimeter placement system was developed, tested, and optimized to allow accurate and reproducible placement of the dosimeters within the cadaveric subjects. A broad-beam, 320-slice, volumetric CT scanner was utilized to perform all CT exams, including five torso exams, four cardiac exams, and three organ perfusion exams. Organ doses ranged in magnitude from less than 1 to over 120 mGy, with the largest doses measured for perfusion imaging. A methodology has been developed that allows fast and accurate measurement of actual organ doses resulting from CT exams. The measurements made with this methodology represent the first time CT organ doses have been directly measured within a human body. These measurements are of great importance because they allow comparison to the doses measured using previous methods, and can be used to more accurately assess the risks from CT imaging.

  1. Analysis of the regimes in the scanner-based laser hardening process

    Science.gov (United States)

    Martínez, S.; Lamikiz, A.; Ukar, E.; Calleja, A.; Arrizubieta, J. A.; Lopez de Lacalle, L. N.

    2017-03-01

    Laser hardening is becoming a consolidated process in different industrial sectors such as the automotive industry or in the die and mold industry. The key to ensure the success in this process is to control the surface temperature and the hardened layer thickness. Furthermore, the development of reliable scanners, based on moving optics for guiding high power lasers at extremely fast speeds allows the rapid motion of laser spots, resulting on tailored shapes of swept areas by the laser. If a scanner is used to sweep a determined area, the laser energy density distribution can be adapted by varying parameters such us the scanning speed or laser power inside this area. Despite its advantages in terms of versatility, the use of scanners for the laser hardening process has not yet been introduced in the thermal hardening industry because of the difficulty of the temperature control and possible non-homogeneous hardness thickness layers. In the present work the laser hardening process with scanning optics applied to AISI 1045 steel has been studied, with special emphasis on the influence of the scanning speed and the results derived from its variation, the evolution of the hardened layer thickness and different strategies for the control of the process temperature. For this purpose, the hardened material has been studied by measuring microhardness at different points and the shape of the hardened layer has also been evaluated. All tests have been performed using an experimental setup designed to keep a nominal temperature value using a closed-loop control. The tests results show two different regimes depending on the scanning speed and feed rate values. The experimental results conclusions have been validated by means of thermal simulations at different conditions.

  2. Digital dental surface registration with laser scanner for orthodontics set-up planning

    Science.gov (United States)

    Alcaniz-Raya, Mariano L.; Albalat, Salvador E.; Grau Colomer, Vincente; Monserrat, Carlos A.

    1997-05-01

    We present an optical measuring system based on laser structured light suitable for its diary use in orthodontics clinics that fit four main requirements: (1) to avoid use of stone models, (2) to automatically discriminate geometric points belonging to teeth and gum, (3) to automatically calculate diagnostic parameters used by orthodontists, (4) to make use of low cost and easy to use technology for future commercial use. Proposed technique is based in the use of hydrocolloids mould used by orthodontists for stone model obtention. These mould of the inside of patient's mouth are composed of very fluent materials like alginate or hydrocolloids that reveal fine details of dental anatomy. Alginate mould are both very easy to obtain and very low costly. Once captured, alginate moulds are digitized by mean of a newly developed and patented 3D dental scanner. Developed scanner is based in the optical triangulation method based in the projection of a laser line on the alginate mould surface. Line deformation gives uncalibrated shape information. Relative linear movements of the mould with respect to the sensor head gives more sections thus obtaining a full 3D uncalibrated dentition model. Developed device makes use of redundant CCD in the sensor head and servocontrolled linear axis for mould movement. Last step is calibration to get a real and precise X, Y, Z image. All the process is done automatically. The scanner has been specially adapted for 3D dental anatomy capturing in order to fulfill specific requirements such as: scanning time, accuracy, security and correct acquisition of 'hidden points' in alginate mould. Measurement realized on phantoms with known geometry quite similar to dental anatomy present errors less than 0,1 mm. Scanning of global dental anatomy is 2 minutes, and generation of 3D graphics of dental cast takes approximately 30 seconds in a Pentium-based PC.

  3. A study of artefacts in simultaneous PET and MR imaging using a prototype MR compatible PET scanner.

    Science.gov (United States)

    Slates, R B; Farahani, K; Shao, Y; Marsden, P K; Taylor, J; Summers, P E; Williams, S; Beech, J; Cherry, S R

    1999-08-01

    We have assessed the possibility of artefacts that can arise in attempting to perform simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) using a small prototype MR compatible PET scanner (McPET). In these experiments, we examine MR images for any major artefacts or loss in image quality due to inhomogeneities in the magnetic field, radiofrequency interference or susceptibility effects caused by operation of the PET system inside the MR scanner. In addition, possible artefacts in the PET images caused by the static and time-varying magnetic fields or radiofrequency interference from the MR system were investigated. Biological tissue and a T2-weighted spin echo sequence were used to examine susceptibility artefacts due to components of the McPET scanner (scintillator, optical fibres) situated in the MR field of view. A range of commonly used MR pulse sequences was studied while acquiring PET data to look for possible artefacts in either the PET or MR images. Other than a small loss in signal-to-noise using gradient echo sequences, there was no significant interaction between the two imaging systems. Simultaneous PET and MR imaging of simple phantoms was also carried out in different MR systems with field strengths ranging from 0.2 to 4.7 T. The results of these studies demonstrate that it is possible to acquire PET and MR images simultaneously, without any significant artefacts or loss in image quality, using our prototype MR compatible PET scanner.

  4. Design of a 3-D surface scanner for lower limb prosthetics: a technical note.

    Science.gov (United States)

    Commean, P K; Smith, K E; Vannier, M W

    1996-07-01

    A three-dimensional (3-D) noncontact optical surface range sensing imaging system that captures the entire circumferential and distal end surfaces of lower limb residua in less than 1 second has been developed. The optical surface scanner (OSS) consists of four charge injection device (CID) cameras and three white light projectors, mounted on a rigid frame surrounding the subject's residuum, allowing 360 degrees surface coverage of the lower residual limb. Anatomic 3-D computer graphics reconstruction of a residuum surface, recorded with the OSS imaging system, is used for visualization and measurement. One cubical and two spherical calibration test objects were used to obtain a system precision of less than 1 mm. In a study conducted with 13 persons with below knee (BK) amputation, the OSS system was compared to calipers, electromagnetic digitizer, and volumetric computed tomography with better than 1 mm precision on plaster positive casts and approximately 2 mm on the residual limbs.

  5. Improved spatial resolution in PET scanners using sampling techniques

    Science.gov (United States)

    Surti, Suleman; Scheuermann, Ryan; Werner, Matthew E.; Karp, Joel S.

    2009-01-01

    Increased focus towards improved detector spatial resolution in PET has led to the use of smaller crystals in some form of light sharing detector design. In this work we evaluate two sampling techniques that can be applied during calibrations for pixelated detector designs in order to improve the reconstructed spatial resolution. The inter-crystal positioning technique utilizes sub-sampling in the crystal flood map to better sample the Compton scatter events in the detector. The Compton scatter rejection technique, on the other hand, rejects those events that are located further from individual crystal centers in the flood map. We performed Monte Carlo simulations followed by measurements on two whole-body scanners for point source data. The simulations and measurements were performed for scanners using scintillators with Zeff ranging from 46.9 to 63 for LaBr3 and LYSO, respectively. Our results show that near the center of the scanner, inter-crystal positioning technique leads to a gain of about 0.5-mm in reconstructed spatial resolution (FWHM) for both scanner designs. In a small animal LYSO scanner the resolution improves from 1.9-mm to 1.6-mm with the inter-crystal technique. The Compton scatter rejection technique shows higher gains in spatial resolution but at the cost of reduction in scanner sensitivity. The inter-crystal positioning technique represents a modest acquisition software modification for an improvement in spatial resolution, but at a cost of potentially longer data correction and reconstruction times. The Compton scatter rejection technique, while also requiring a modest acquisition software change with no increased data correction and reconstruction times, will be useful in applications where the scanner sensitivity is very high and larger improvements in spatial resolution are desirable. PMID:19779586

  6. Hologon Laser Scanners For Nonimpact Printing

    Science.gov (United States)

    Kramer, Charles J.

    1983-09-01

    A novel holographic laser beam deflector is described which is invariant with regard to deflector wobble and centration errors, has high radiometric efficiency and provides a bow free scan. The deflector's insensitivity to mechanical error and absence of facet pyramidal error enables a flat field, linearized, high resolution image to be generated utilizing only a simple spherical optical system. In addition to the cost benefits derived from using spherical optical elements, the inherent symmetry they provide readily enables the deflector system to be extended to two dimensional scanning applications. Performance data for a hologon deflector system operating at 633 nm will be presented. Also, a procedure for determining what parameters must be incorporated into the hologon deflector element for nonimpact printing applications will be outlined.

  7. Characterization of a Large, Low-Cost 3D Scanner

    Directory of Open Access Journals (Sweden)

    Jeremy Straub

    2015-01-01

    Full Text Available Imagery-based 3D scanning can be performed by scanners with multiple form factors, ranging from small and inexpensive scanners requiring manual movement around a stationary object to large freestanding (nearly instantaneous units. Small mobile units are problematic for use in scanning living creatures, which may be unwilling or unable to (or for the very young and animals, unaware of the need to hold a fixed position for an extended period of time. Alternately, very high cost scanners that can capture a complete scan within a few seconds are available, but they are cost prohibitive for some applications. This paper seeks to assess the performance of a large, low-cost 3D scanner, presented in prior work, which is able to concurrently capture imagery from all around an object. It provides the capabilities of the large, freestanding units at a price point akin to the smaller, mobile ones. This allows access to 3D scanning technology (particularly for applications requiring instantaneous imaging at a lower cost. Problematically, prior analysis of the scanner’s performance was extremely limited. This paper characterizes the efficacy of the scanner for scanning both inanimate objects and humans. Given the importance of lighting to visible light scanning systems, the scanner’s performance under multiple lighting configurations is evaluated, characterizing its sensitivity to lighting design.

  8. EGRONOMIC FINGERPRINT SCANNER DESIGN FOR PEOPLE WITH MOTOR NEURON DISEASES

    Directory of Open Access Journals (Sweden)

    Abdulkareem Al-Alwani

    2013-01-01

    Full Text Available Fingerprint devices have evolved with time for authentication and identification purposes. It is used in generic security and social applications where identification and logging is required when entering that premises. In some circumstances the lag time increases due to increase in human entrees such as at immigration points, airports, random security checkups, attendance loggers. The increase in overall time due to individual human delay factors present a major hindrance in smooth security as well as organizational operations. The delay could occur due to non-technical factor such as not placing the fingers firmly in the surface of the device. This is a major cause of concern for senior citizens and people with motor neuron diseases such as Parkinson’s, Huntington’s and Alzheimer’s disease. Therefore, a design is proposed in this research which can help the scanner to acquire fast and precise fingerprint scan of senior citizens and people with motor neuron diseases. This design uses ergonomically designed cover head for the scanner whose working is based on the Poka Yoke principle which assists firm finger placement on the scanner. In this research, 250 fingerprint scans were taken for statistical analysis using a normal fingerprint scanner and our proposed model scanner. Statistical comparison between the two results shows that our proposed model performs much better in terms of time consumption and accuracy.

  9. Moths on the Flatbed Scanner: The Art of Joseph Scheer

    Directory of Open Access Journals (Sweden)

    Stephen L. Buchmann

    2011-12-01

    Full Text Available During the past decade a few artists and even fewer entomologists discovered flatbed scanning technology, using extreme resolution graphical arts scanners for acquiring high magnification digital images of plants, animals and inanimate objects. They are not just for trip receipts anymore. The special attributes of certain scanners, to image thick objects is discussed along with the technical features of the scanners including magnification, color depth and shadow detail. The work of pioneering scanner artist, Joseph Scheer from New York’s Alfred University is highlighted. Representative flatbed-scanned images of moths are illustrated along with techniques to produce them. Collecting and preparing moths, and other objects, for scanning are described. Highlights of the Fulbright sabbatical year of professor Scheer in Arizona and Sonora, Mexico are presented, along with comments on moths in science, folklore, art and pop culture. The use of flatbed scanners is offered as a relatively new method for visualizing small objects while acquiring large files for creating archival inkjet prints for display and sale.

  10. Moths on the Flatbed Scanner: The Art of Joseph Scheer.

    Science.gov (United States)

    Buchmann, Stephen L

    2011-12-14

    During the past decade a few artists and even fewer entomologists discovered flatbed scanning technology, using extreme resolution graphical arts scanners for acquiring high magnification digital images of plants, animals and inanimate objects. They are not just for trip receipts anymore. The special attributes of certain scanners, to image thick objects is discussed along with the technical features of the scanners including magnification, color depth and shadow detail. The work of pioneering scanner artist, Joseph Scheer from New York's Alfred University is highlighted. Representative flatbed-scanned images of moths are illustrated along with techniques to produce them. Collecting and preparing moths, and other objects, for scanning are described. Highlights of the Fulbright sabbatical year of professor Scheer in Arizona and Sonora, Mexico are presented, along with comments on moths in science, folklore, art and pop culture. The use of flatbed scanners is offered as a relatively new method for visualizing small objects while acquiring large files for creating archival inkjet prints for display and sale.

  11. Applications and requirements for MEMS scanner mirrors

    Science.gov (United States)

    Wolter, Alexander; Hsu, Shu-Ting; Schenk, Harald; Lakner, Hubert K.

    2005-01-01

    Micro scanning mirrors are quite versatile MEMS devices for the deflection of a laser beam or a shaped beam from another light source. The most exciting application is certainly in laser-scanned displays. Laser television, home cinema and data projectors will display the most brilliant colors exceeding even plasma, OLED and CRT. Devices for front and rear projection will have advantages in size, weight and price. These advantages will be even more important in near-eye virtual displays like head-mounted displays or viewfinders in digital cameras and potentially in UMTS handsets. Optical pattern generation by scanning a modulated beam over an area can be used also in a number of other applications: laser printers, direct writing of photo resist for printed circuit boards or laser marking and with higher laser power laser ablation or material processing. Scanning a continuous laser beam over a printed pattern and analyzing the scattered reflection is the principle of barcode reading in 1D and 2D. This principle works also for identification of signatures, coins, bank notes, vehicles and other objects. With a focused white-light or RGB beam even full color imaging with high resolution is possible from an amazingly small device. The form factor is also very interesting for the application in endoscopes. Further applications are light curtains for intrusion control and the generation of arbitrary line patterns for triangulation. Scanning a measurement beam extends point measurements to 1D or 2D scans. Automotive LIDAR (laser RADAR) or scanning confocal microscopy are just two examples. Last but not least there is the field of beam steering. E.g. for all-optical fiber switches or positioning of read-/write heads in optical storage devices. The variety of possible applications also brings a variety of specifications. This publication discusses various applications and their requirements.

  12. Productive Scanner For The Business Imaging Market

    Science.gov (United States)

    Wiggins, Douglas

    1988-05-01

    A substantial effort has been made to understand the requirements for a high-productivity scanning machine intended for the business imaging market. A system intended to handle business imaging applications would consist of a computer system, mass storage capability, scanning equipment and printing equipment. The advent of optical-disk and other high-density storage techniques has made possible economical digital storage. This is leading to the need for scanning capacity to utilize this capability. This paper will describe what productivity is for this market, the machine requirements and the implementation strategy. All of the concept work has been done to prove that the suggested approach is viable.

  13. Design and performance of HEAD PENN-PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Freifelder, R.; Karp, J.S. (Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Radiology); Geagan, M.; Muehllehner, G. (UGM Medical Systems Inc., Philadelphia, PA (United States))

    1994-08-01

    A new PET scanner for brain imaging (and animals) has been designed with very high sensitivity and spatial resolution. The design is an evolution of the PENN-PET scanner, which uses large position-sensitive NaI(Tl) detectors, with Anger-type positioning logic, and which allows 3-D volume imaging, without septa. The new design is built with a single annular crystal coupled to 180 photomultiplier tubes, and uses local triggering electronics to subdivide the detector into small zones and to determine coincident events within the detector. The axial acceptance angle of [+-] 27 deg, with a field-of-view of 25.6 cm, is larger than any currently operating PET scanner. Performance measurements are presented.

  14. Calibration procedure for a laser triangulation scanner with uncertainty evaluation

    Science.gov (United States)

    Genta, Gianfranco; Minetola, Paolo; Barbato, Giulio

    2016-11-01

    Most of low cost 3D scanning devices that are nowadays available on the market are sold without a user calibration procedure to correct measurement errors related to changes in environmental conditions. In addition, there is no specific international standard defining a procedure to check the performance of a 3D scanner along time. This paper aims at detailing a thorough methodology to calibrate a 3D scanner and assess its measurement uncertainty. The proposed procedure is based on the use of a reference ball plate and applied to a triangulation laser scanner. Experimental results show that the metrological performance of the instrument can be greatly improved by the application of the calibration procedure that corrects systematic errors and reduces the device's measurement uncertainty.

  15. Spectral reflectance estimation using a six-color scanner

    Science.gov (United States)

    Tominaga, Shoji; Kohno, Satoshi; Kakinuma, Hirokazu; Nohara, Fuminori; Horiuchi, Takahiko

    2009-01-01

    A method is proposed for estimating the spectral reflectance function of an object surface by using a six-color scanner. The scanner is regarded as a six-band spectral imaging system, since it captures six color channels in total from two separate scans using two difference lamps. First, we describe the basic characteristics of the imaging systems for a HP color scanner and a multiband camera used for comparison. Second, we describe a computational method for recovering surface-spectral reflectances from the noisy sensor outputs. A LMMSE estimator is presented as an optimal estimator. We discuss the reflectance estimation for non-flat surfaces with shading effect. A solution method is presented for the reliable reflectance estimation. Finally, the performance of the proposed method is examined in detail on experiments using the Macbeth Color Checker and non-flat objects.

  16. Dental impressions using 3D digital scanners: virtual becomes reality.

    Science.gov (United States)

    Birnbaum, Nathan S; Aaronson, Heidi B

    2008-10-01

    The technologies that have made the use of three-dimensional (3D) digital scanners an integral part of many industries for decades have been improved and refined for application to dentistry. Since the introduction of the first dental impressioning digital scanner in the 1980s, development engineers at a number of companies have enhanced the technologies and created in-office scanners that are increasingly user-friendly and able to produce precisely fitting dental restorations. These systems are capable of capturing 3D virtual images of tooth preparations, from which restorations may be fabricated directly (ie, CAD/CAM systems) or fabricated indirectly (ie, dedicated impression scanning systems for the creation of accurate master models). The use of these products is increasing rapidly around the world and presents a paradigm shift in the way in which dental impressions are made. Several of the leading 3D dental digital scanning systems are presented and discussed in this article.

  17. Restoration of Hyperspectral Push-Broom Scanner Data

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Nielsen, Allan Aasbjerg; Conradsen, Knut

    1997-01-01

    Several effects combine to distort the multispectral data that are obtained from push-broom scanners. We develop an algorithm for restoration of such data, illustrated on images from the ROSIS scanner. In push-broom scanners variation between elements in the detector array results in a strong...... striping along flight lines. A non-systematic striping is also present along flight lines. Furthermore, line drop-outs occur, and finally, various types of electronic noise of salt-and-pepper type are also present. We describe techniques for the correction for all these types of effects. Line drop...... back into the original spectral space results in noise corrected variables. The noise components will now have been removed from the entire original data set by working on a smaller set of noise contaminated transformed variables only. The application of the above techniques results in a dramatic...

  18. Fluorescent imaging over an ultra-large field-of-view of 532 cm2 using a flatbed scanner

    Science.gov (United States)

    Göröcs, Zoltán. S.; Ling, Yuye; Yu, Meng D.; Karahalios, Dimitri; Mogharabi, Kian; Lu, Kenny; Wei, Qingshan; Ozcan, Aydogan

    2014-03-01

    We introduce a fluorescent imaging method that is capable of detecting fluorescent micro-particles over an ultra-wide field of view of 19 cm × 28 cm using a modified flatbed scanner. We added a custom-designed absorbing emission filter, a computer controlled two dimensional LED array, and modified the driver of the scanner to maximize the sensitivity, exposure time, and gain for fluorescent detection of micro-objects. This high-throughput fluorescent imaging device used in conjunction with a microfluidic sample holder enables rapid screening of fluorescent micro-objects inside more than 2.2mL of optically dense media (i.e., whole blood) within 5 minutes. The device is sensitive enough to detect fluorescently labeled cells, and generates images that have an effective pixel count of 2.2 Giga-pixels.

  19. Scanner-based image quality measurement system for automated analysis of EP output

    Science.gov (United States)

    Kipman, Yair; Mehta, Prashant; Johnson, Kate

    2003-12-01

    Inspection of electrophotographic print cartridge quality and compatibility requires analysis of hundreds of pages on a wide population of printers and copiers. Although print quality inspection is often achieved through the use of anchor prints and densitometry, more comprehensive analysis and quantitative data is desired for performance tracking, benchmarking and failure mode analysis. Image quality measurement systems range in price and performance, image capture paths and levels of automation. In order to address the requirements of a specific application, careful consideration was made to print volume, budgetary limits, and the scope of the desired image quality measurements. A flatbed scanner-based image quality measurement system was selected to support high throughput, maximal automation, and sufficient flexibility for both measurement methods and image sampling rates. Using an automatic document feeder (ADF) for sample management, a half ream of prints can be measured automatically without operator intervention. The system includes optical character recognition (OCR) for automatic determination of target type for measurement suite selection. This capability also enables measurement of mixed stacks of targets since each sample is identified prior to measurement. In addition, OCR is used to read toner ID, machine ID, print count, and other pertinent information regarding the printing conditions and environment. This data is saved to a data file along with the measurement results for complete test documentation. Measurement methods were developed to replace current methods of visual inspection and densitometry. The features that were being analyzed visually could be addressed via standard measurement algorithms. Measurement of density proved to be less simple since the scanner is not a densitometer and anything short of an excellent estimation would be meaningless. In order to address the measurement of density, a transfer curve was built to translate the

  20. Management Concerns for Optical Based Filing Systems

    Science.gov (United States)

    1990-03-01

    terminals, WORM Palo Alto, CA 94303 drives, optical jukeboxes, printers, scanners. Candi Technology Inc. Systems integrators providing 2354 Calle Del Mundo ...n.3, p. 68, 6 February 1989. Dortch, M., "A Storage Media Primer ", LAN Times, v.6, n.1, pp. 38-39, January 1989. Dukeman, John, "Optical Disk - A

  1. Calibration of Images with 3D range scanner data

    OpenAIRE

    Adalid López, Víctor Javier

    2009-01-01

    Projecte fet en col.laboració amb EPFL 3D laser range scanners are used in extraction of the 3D data in a scene. Main application areas are architecture, archeology and city planning. Thought the raw scanner data has a gray scale values, the 3D data can be merged with colour camera image values to get textured 3D model of the scene. Also these devices are able to take a reliable copy in 3D form objects, with a high level of accuracy. Therefore, they scanned scenes can be use...

  2. Performance Assessment of Wire-Scanners at CERN

    CERN Document Server

    Baud, G; Emery, J; Gras, JJ; Guerrero, A; Piselli, E

    2013-01-01

    This article describes the current fast wire-scanner devices installed in circular accelerators at CERN with an emphasis on the error studies carried out during the last two runs. At present the wire-scanners have similar acquisition systems but are varied in terms of mechanics. Several measurement campaigns were performed aimed at establishing optimal operational settings and to identify and assess systematic errors. In several cases the results led to direct performance improvements while in others this helped in defining the requirements for new detectors.

  3. Satellite orientation and position for geometric correction of scanner imagery.

    Science.gov (United States)

    Salamonowicz, P.H.

    1986-01-01

    The USGS Mini Image Processing System currently relies on a polynomial method for geometric correction of Landsat multispectral scanner (MSS) data. A large number of ground control points are required because polynomials do not model the sources of error. In order to reduce the number of necessary points, a set of mathematical equations modeling the Landsat satellite motions and MSS scanner has been derived and programmed. A best fit to the equations is obtained by using a least-squares technique that permits computation of the satellite orientation and position parameters based on only a few control points.-from Author

  4. Impact of lighting and attire on 3D scanner performance

    Science.gov (United States)

    Ajjimaporn, Pann; Feist, Dakota; Straub, Jeremy; Kerlin, Scott

    2015-05-01

    This paper considers the impact of lighting and attire on the performance of a previously created low-cost 3D scanning system. It considers the effect of adjusting the lighting configuration and of the subject's clothing on the quality of the scans and the number and types of objects that can be scanned. The experimentation performed tested different types (colors and textures) of clothing to assess which produced the best scans and multiple lighting configurations. This paper presents the results from this experimentation and, from this, make generalizations about optimizing visible light scanner performance before concluding with a discussion of scanner efficacy.

  5. Scanner baseliner monitoring and control in high volume manufacturing

    Science.gov (United States)

    Samudrala, Pavan; Chung, Woong Jae; Aung, Nyan; Subramany, Lokesh; Gao, Haiyong; Gomez, Juan-Manuel

    2016-03-01

    We analyze performance of different customized models on baseliner overlay data and demonstrate the reduction in overlay residuals by ~10%. Smart Sampling sets were assessed and compared with the full wafer measurements. We found that performance of the grid can still be maintained by going to one-third of total sampling points, while reducing metrology time by 60%. We also demonstrate the feasibility of achieving time to time matching using scanner fleet manager and thus identify the tool drifts even when the tool monitoring controls are within spec limits. We also explore the scanner feedback constant variation with illumination sources.

  6. Localization of a mobile laser scanner via dimensional reduction

    Science.gov (United States)

    Lehtola, Ville V.; Virtanen, Juho-Pekka; Vaaja, Matti T.; Hyyppä, Hannu; Nüchter, Andreas

    2016-11-01

    We extend the concept of intrinsic localization from a theoretical one-dimensional (1D) solution onto a 2D manifold that is embedded in a 3D space, and then recover the full six degrees of freedom for a mobile laser scanner with a simultaneous localization and mapping algorithm (SLAM). By intrinsic localization, we mean that no reference coordinate system, such as global navigation satellite system (GNSS), nor inertial measurement unit (IMU) are used. Experiments are conducted with a 2D laser scanner mounted on a rolling prototype platform, VILMA. The concept offers potential in being extendable to other wheeled platforms.

  7. A ’Millipede’ scanner model - Energy consumption and performance

    OpenAIRE

    Engelen, Johan B.C.; Khatib, Mohammed G.

    2008-01-01

    This short report (1) describes an energy model for the seek and read/write operations in a mass-balanced Y-scanner for parallel-probe storage by IBM [1] and (2) updates the settings of the MEMS model in DiskSim with recent published figures from this XY-scanner. To speedup system simulations, a straight forward second-order model is used without control loop. Read/write operation is modeled by quasi-static calculations. To approximate seek behavior, ’bang-bang’ control is assumed; the result...

  8. Tunable micro-optics

    CERN Document Server

    Duppé, Claudia

    2015-01-01

    Presenting state-of-the-art research into the dynamic field of tunable micro-optics, this is the first book to provide a comprehensive survey covering a varied range of topics including novel materials, actuation concepts and new imaging systems in optics. Internationally renowned researchers present a diverse range of chapters on cutting-edge materials, devices and subsystems, including soft matter, artificial muscles, tunable lenses and apertures, photonic crystals, and complete tunable imagers. Special contributions also provide in-depth treatment of micro-optical characterisation, scanners, and the use of natural eye models as inspiration for new concepts in advanced optics. With applications extending from medical diagnosis to fibre telecommunications, Tunable Micro-optics equips readers with a solid understanding of the broader technical context through its interdisciplinary approach to the realisation of new types of optical systems. This is an essential resource for engineers in industry and academia,...

  9. Using Contactless Scanners for Quality Inspection

    Directory of Open Access Journals (Sweden)

    Mendřický Radomír

    2017-01-01

    Full Text Available The article presents the research of use of modern 3D measurement contactless methods for quality inspection in automotive industry production. The experience with measuring functional assemblies and parts of complex shapes as well as advantages of optical measurement methods are shown on practical research example, whose aim was to find effective procedures and methods of obtaining 3-dimensional high-definition models of measured components. The obtained models were then subjected to inspection of their dimensional and shape accuracy, which was performed by means of comparison with the nominal CAD model, as well as to analyses of the assembly functionality by searching or collision situations of the movable parts of this mechanism.

  10. Estimating Single Tree Stem Volume of Pinus sylvestris Using Airborne Laser Scanner and Multispectral Line Scanner Data

    Directory of Open Access Journals (Sweden)

    Barbara Koch

    2011-05-01

    Full Text Available So far, only a few studies have been carried out in central European forests to estimate individual tree stem volume of pine trees from high resolution remote sensing data. In this article information derived from airborne laser scanner and multispectral line scanner data were tested to predict the stem volume of 178 pines (Pinus sylvestris in a study site in the south-west of Germany. First, tree crowns were automatically delineated using both multispectral and laser scanner data. Next, tree height, crown diameter and crown volume were derived for each crown segment. All combinations of the derived tree features were used as explanatory variables in allometric models to predict the stem volume. A model with tree height and crown diameter had the best performance with respect to the prediction accuracy determined by a leave-one-out cross-validation: Root Mean Square Error (RMSE = 24.02% and Bias = 1.36%.

  11. QUICK DETERMINATION OF CRYSTAL SIZE DISTRIBUTIONS OF ROCKS BY MEANS OF A COLOR SCANNER

    Directory of Open Access Journals (Sweden)

    Simone Tarquini

    2011-05-01

    Full Text Available An acquisition and analysis method based on a commercial, low-cost, high-resolution film scanner is presented. It allows to collect data from standard rock thin sections with a resolution up to 9.4 μm per pixel. Common and general purpose facilities (scanner + PC + image analysis software may thus be transformed in an appropriate tool for quantitative textural analysis of rocks. The procedure implies the acquisition of four images with crossed polarizers and one parallel light image. Crystal boundaries are extracted from fields in crossed polarizers, while markers for mineral recognition are obtained thresholding the parallel light image. The method is tested for fresh rocks with simple mineralogy (harzburgites and marbles with no more than three phases, all exhibiting well distinct optical properties. Image processing is performed developing procedures with VISILOG 5.2 package. 2-D size data from binary images are converted to 3-D size data applying stereological corrections. 3-D data are reported in bi-logarithmic diagrams, plotting the crystal number density versus characteristic lengths. The harzburgite samples show a scale invariance of size distributions of olivine while mosaic equant marbles exhibit a different size distribution pattern, without scale invariance and a relative maximum.

  12. Design and operation of a portable scanner for high performance microchip capillary array electrophoresis.

    Science.gov (United States)

    Scherer, James R; Liu, Peng; Mathies, Richard A

    2010-11-01

    We have developed a compact, laser-induced fluorescence detection scanner, the multichannel capillary array electrophoresis portable scanner (McCAEPs) as a platform for electrophoretic detection and control of high-throughput, integrated microfluidic devices for genetic and other analyses. The instrument contains a confocal optical system with a rotary objective for detecting four different fluorescence signals, a pneumatic system consisting of two pressure/vacuum pumps and 28 individual addressable solenoid valves for control of on-chip microvalves and micropumps, four Polymerase Chain Reaction (PCR) temperature control systems, and four high voltage power supplies for electrophoresis. The detection limit of the instrument is ~20 pM for on-chip capillary electrophoresis of fluorescein dyes. To demonstrate the system performance for forensic short tandem repeat (STR) analysis, two experiments were conducted: (i) electrophoretic separation and detection of STR samples on a 96-lane microfabricated capillary array electrophoresis microchip. Fully resolved PowerPlex(®) 16 STR profiles amplified from 1 ng of 9947A female standard DNA were successfully obtained; (ii) nine-plex STR amplification, sample injection, separation, and fluorescence detection of 100-copy 9948 male standard DNA in a single integrated PCR- capillary electrophoresis microchip. These results demonstrate that the McCAEPs can be used as a versatile control and detection instrument that operates integrated microfluidic devices for high-performance forensic human identification.

  13. Demonstration: A smartphone 3D functional brain scanner

    DEFF Research Database (Denmark)

    Stahlhut, Carsten; Stopczynski, Arkadiusz; Larsen, Jakob Eg

    We demonstrate a fully portable 3D real-time functional brain scanner consisting of a wireless 14-channel ‘Neuroheadset‘ (Emotiv EPOC) and a Nokia N900 smartphone. The novelty of our system is the ability to perform real-time functional brain imaging on a smartphone device, including stimulus del......, tablet computers, and netbooks) that are based on Linux operating systems....

  14. Feature-space transformation improves supervised segmentation across scanners

    DEFF Research Database (Denmark)

    van Opbroek, Annegreet; Achterberg, Hakim C.; de Bruijne, Marleen

    2015-01-01

    Image-segmentation techniques based on supervised classification generally perform well on the condition that training and test samples have the same feature distribution. However, if training and test images are acquired with different scanners or scanning parameters, their feature distributions...

  15. Measurement Report for the PS-boosterWire Scanner

    CERN Document Server

    Vollinger, Christine; Kramer, Patrick; CERN. Geneva. ATS Department

    2017-01-01

    This Note discusses the EM-measurements carried out on the prototype of the PS-Booster wire scanner. The aim of these measurements was to identify intrinsic resonances that are to be evaluated for their contribution to the longitudinal beam impedance of the machine.

  16. Sea surface temperature mapping using a thermal infrared scanner

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Pandya, R.M.; Mathur, K.M.; Charyulu, R.J.K.; Rao, L.V.G.

    1 metre water column below the sea surface. A thermal infrared scanner developed by the Space Applications Centre (ISRO), Ahmedabad was operated on board R.V. Gaveshani in April/May 1984 for mapping SST over the eastern Arabian Sea. SST values...

  17. Benchmarking Advanced Control Algorithms for a Laser Scanner System

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Ordys, A.W.; Smillie, I.

    1996-01-01

    The paper describes tests performed on the laser scanner system toassess feasibility of modern control techniques in achieving a requiredperformance in the trajectory following problem. The two methods tested areQTR H-infinity and Predictive Control. The results are ilustated ona simulation example....

  18. NMR of geophysical drill cores with a mobile Halbach scanner

    Energy Technology Data Exchange (ETDEWEB)

    Talnishnikh, E.

    2007-08-21

    This thesis is devoted to a mobile NMR with an improved Halbach scanner. This is a lightweight tube-shaped magnet with sensitive volume larger and a homogeneity of the magnetic field higher than the previous prototype version. The improved Halbach scanner is used for analysis of water-saturated drill cores and plugs with diameters up to 60 mm. To provide the analysis, the standard 1D technique with the CPMG sequence as well as 2D correlation experiments were successfully applied and adapted to study properties of fluid-saturated sediments. Afterwards the Halbach scanner was calibrated to fast non-destructive measurements of porosity, relaxation time distributions, and estimation of permeability. These properties can be calculated directly from the NMR data using the developed methodology. Any independent measurements of these properties with other methods are not needed. One of the main results of this work is the development of a new NMR on-line core scanner for measurements of porosity in long cylindrical and semi cylindrical drill cores. Also dedicated software was written to operate the NMR on-line core scanner. The physical background of this work is the study of the diffusion influence on transverse relaxation. The diffusion effect in the presence of internal gradients in porous media was probed by 1D and 2D experiments. The transverse relaxation time distributions obtained from 1D and from 2D experiments are comparable but different in fine details. Two new methodologies were developed based on the results of this study. First is the methodology quantifying the influence of diffusion in the internal gradients of water-saturated sediments on transverse relaxation from 2D correlation experiments. The second one is the correction of the permeability estimation from the NMR data taking in account the influence of the diffusion. Furthermore, PFG NMR technique was used to study restricted diffusion in the same kind of samples. Preliminary results are reported

  19. Raising the Barcode Scanner: Technology and Productivity in the Retail Sector

    OpenAIRE

    Emek Basker

    2011-01-01

    Barcodes and barcode scanners transformed the grocery industry in the 1970s. I use store-level data from the 1972, 1977, and 1982 Census of Retail Trade, matched to data on store scanner installations, to estimate scanners' effect on labor productivity. I find that early scanners increased a store's labor productivity, on average, by approximately 4.5 percent in the first few years. The effect was larger in stores carrying more packaged products, consistent with the presence of network extern...

  20. Guide to quickly build high-quality three-dimensional models with a structured light range scanner.

    Science.gov (United States)

    Shi, Bao-Quan; Liang, Jin

    2016-12-20

    In literature, there are many reports about how to build high-precision, high-speed, and/or flexibly structured light range scanners. Whereas, there are few papers reported about how to implement the scanning to reach the full potential of the scanners when digitizing various objects. In this paper, some scanning strategies adopted by the structured light range scanner XJTUOM are introduced. In order to build high-quality three-dimensional (3D) models for various applications, such as 3D inspection, if necessary, the object surface is prepared in advance by an application of coating spray. Then, a precise 3D coordinate control network (CNN) is established to control the overall measurement accuracy. When the sensor is adjusted to face the object, a visual measuring volume, which can guide the scanning, is automatically aligned to the established CNN. Meanwhile, to maintain the local region scanning accuracy, simple rules are developed to check the low-quality regions in each scanning. Finally, the advantages and limitations of these scanning strategies are discussed in detail. We hope our work will be helpful in order for others to make their own scanning plans with similar optical devices at hand.

  1. Standardizing CT lung density measure across scanner manufacturers.

    Science.gov (United States)

    Chen-Mayer, Huaiyu Heather; Fuld, Matthew K; Hoppel, Bernice; Judy, Philip F; Sieren, Jered P; Guo, Junfeng; Lynch, David A; Possolo, Antonio; Fain, Sean B

    2017-03-01

    Computed Tomography (CT) imaging of the lung, reported in Hounsfield Units (HU), can be parameterized as a quantitative image biomarker for the diagnosis and monitoring of lung density changes due to emphysema, a type of chronic obstructive pulmonary disease (COPD). CT lung density metrics are global measurements based on lung CT number histograms, and are typically a quantity specifying either the percentage of voxels with CT numbers below a threshold, or a single CT number below which a fixed relative lung volume, nth percentile, falls. To reduce variability in the density metrics specified by CT attenuation, the Quantitative Imaging Biomarkers Alliance (QIBA) Lung Density Committee has organized efforts to conduct phantom studies in a variety of scanner models to establish a baseline for assessing the variations in patient studies that can be attributed to scanner calibration and measurement uncertainty. Data were obtained from a phantom study on CT scanners from four manufacturers with several protocols at various tube potential voltage (kVp) and exposure settings. Free from biological variation, these phantom studies provide an assessment of the accuracy and precision of the density metrics across platforms solely due to machine calibration and uncertainty of the reference materials. The phantom used in this study has three foam density references in the lung density region, which, after calibration against a suite of Standard Reference Materials (SRM) foams with certified physical density, establishes a HU-electron density relationship for each machine-protocol. We devised a 5-step calibration procedure combined with a simplified physical model that enabled the standardization of the CT numbers reported across a total of 22 scanner-protocol settings to a single energy (chosen at 80 keV). A standard deviation was calculated for overall CT numbers for each density, as well as by scanner and other variables, as a measure of the variability, before and after the

  2. Beam dumping ghost signals in electric sweep scanners

    Energy Technology Data Exchange (ETDEWEB)

    Stockli, M.P.; /SNS Project, Oak Ridge /Tennessee U.; Leitner, M.; /LBL, Berkeley; Moehs, D.P.; /Fermilab; Keller, R.; /LBL, Berkeley; Welton, R.F.; /SNS Project, Oak Ridge

    2004-12-01

    Over the last 20 years many labs started to use Allison scanners to measure low-energy ion beam emittances. We show that large trajectory angles produce ghost signals due to the impact of the beamlet on the electric deflection plates. The strength of the ghost signal is proportional to the amount of beam entering the scanner. Depending on the ions and their velocity, ghost signals can have the opposite polarity as the main beam signals or the same polarity. These ghost signals are easily overlooked because they partly overlap the real signals, they are mostly below the 1% level, and they are often hidden in the noise. However, they cause significant errors in emittance estimates because they are associated with large trajectory angles. The strength of ghost signals, and the associated errors, can be drastically reduced with a simple modification of the deflection plates.

  3. Object 3D surface reconstruction approach using portable laser scanner

    Science.gov (United States)

    Xu, Ning; Zhang, Wei; Zhu, Liye; Li, Changqing; Wang, Shifeng

    2017-06-01

    The environment perception plays the key role for a robot system. The 3D surface of the objects can provide essential information for the robot to recognize objects. This paper present an approach to reconstruct objects' 3D surfaces using a portable laser scanner we designed which consists of a single-layer laser scanner, an encoder, a motor, power supply and mechanical components. The captured point cloud data is processed to remove the discrete points, denoise filtering, stitching and registration. Then the triangular mesh generation of point cloud is accomplished by using Gaussian bilateral filtering, ICP real-time registration and greedy triangle projection algorithm. The experiment result shows the feasibility of the device designed and the algorithm proposed.

  4. Quality of Plate Copies Digitized with a Commercially Available Scanner

    Science.gov (United States)

    Strelnitski, V.; Davis, A.

    2004-12-01

    Digitization of all the (ca. 8,000) 8"x10" plates of the Maria Mitchell Observatory's plate collection with the commercially available scanner AgfaScan T5000 took about 1.5 years. Scanning these plates with the same nominal resolution (10-20 microns) using one of the best astronomical digital microdensitometers would be about 8 times longer, and, correspondingly, 8 times more expensive. Such a fast job may raise doubts in the quality of the scans. We show, by comparison with the control scans obtained with the STScI's GAMMA laser microdensitometer, that the additional random errors for stellar photometry introduced by AgfaScan T5000 are, typically, less than 0.05 mag, and that this scanner does not produce any detectable additional astrometric errors. This project was supported by the NSF/REU grant AST-0354056 and the Nantucket Maria Mitchell Association.

  5. Alignment and resolution studies of a MARS scanner

    CERN Document Server

    Butler, A P; Bell, S T; Chelkov, G; Demichev, M; Gongadze, A; Kotov, S; Kozhevnikov, D; Kruchonak, U; Potrap, I; Smolyanskiy, P; Zhemchugov, A

    2015-01-01

    The MARS scanner is designed for the x-ray spectroscopic study of samples with the aid of computer tomography methods. Computer tomography allows the reconstruction of slices of an investigated sample using a set of shadow projections obtained for different angles. Projections in the MARS scanner are produced using a cone x-ray beam geometry. Correct reconstruction in this scheme requires precise knowledge of several geometrical parameters of a tomograph, such as displacement of a rotation axis, x-ray source position with respect to a camera, and camera inclinations. Use of inaccurate parameters leads to a poor sample reconstruction. Non-ideal positioning of camera, x-ray source and cylindrical rotating frame (gantry) itself on which these parts are located, leads to the need for tomograph alignment. In this note we describe the alignment procedure that was used to get different geometrical corrections for the reconstruction. Also, several different estimations of the final spatial resolution for reconstructe...

  6. Robust Object Segmentation Using a Multi-Layer Laser Scanner

    Directory of Open Access Journals (Sweden)

    Beomseong Kim

    2014-10-01

    Full Text Available The major problem in an advanced driver assistance system (ADAS is the proper use of sensor measurements and recognition of the surrounding environment. To this end, there are several types of sensors to consider, one of which is the laser scanner. In this paper, we propose a method to segment the measurement of the surrounding environment as obtained by a multi-layer laser scanner. In the segmentation, a full set of measurements is decomposed into several segments, each representing a single object. Sometimes a ghost is detected due to the ground or fog, and the ghost has to be eliminated to ensure the stability of the system. The proposed method is implemented on a real vehicle, and its performance is tested in a real-world environment. The experiments show that the proposed method demonstrates good performance in many real-life situations.

  7. Robust object segmentation using a multi-layer laser scanner.

    Science.gov (United States)

    Kim, Beomseong; Choi, Baehoon; Yoo, Minkyun; Kim, Hyunju; Kim, Euntai

    2014-10-29

    The major problem in an advanced driver assistance system (ADAS) is the proper use of sensor measurements and recognition of the surrounding environment. To this end, there are several types of sensors to consider, one of which is the laser scanner. In this paper, we propose a method to segment the measurement of the surrounding environment as obtained by a multi-layer laser scanner. In the segmentation, a full set of measurements is decomposed into several segments, each representing a single object. Sometimes a ghost is detected due to the ground or fog, and the ghost has to be eliminated to ensure the stability of the system. The proposed method is implemented on a real vehicle, and its performance is tested in a real-world environment. The experiments show that the proposed method demonstrates good performance in many real-life situations.

  8. Photoacoustic imaging using an 8-beam Fabry-Perot scanner

    Science.gov (United States)

    Huynh, Nam; Ogunlade, Olumide; Zhang, Edward; Cox, Ben; Beard, Paul

    2016-03-01

    The planar Fabry Perot (FP) photoacoustic scanner has been shown to provide exquisite high resolution 3D images of soft tissue structures in vivo to depths up to approximately 10mm. However a significant limitation of current embodiments of the concept is low image acquisition speed. To increase acquisition speed, a novel multi-beam scanner architecture has been developed. This enables a line of equally spaced 8 interrogation beams to be scanned simultaneously across the FP sensor and the photoacoustic signals detected in parallel. In addition, an excitation laser operating at 200Hz was used. The combination of parallelising the detection and the high pulse repetition frequency (PRF) of the excitation laser has enabled dramatic reductions in image acquisition time to be achieved. A 3D image can now be acquired in 10 seconds and 2D images at video rates are now possible.

  9. Acoustic noise reduction in a 4 T MRI scanner.

    Science.gov (United States)

    Mechefske, Chris K; Geris, Ryan; Gati, Joseph S; Rutt, Brian K

    2002-01-01

    High-field, high-speed magnetic resonance imaging (MRI) can generate high levels of noise. There is ongoing concern in the medical and imaging research communities regarding the detrimental effects of high acoustic levels on auditory function, patient anxiety, verbal communication between patients and health care workers and ultimately MR image quality. In order to effectively suppress the noise levels inside MRI scanners, the sound field needs to be accurately measured and characterized. This paper presents the results of measurements of the sound radiation from a gradient coil cylinder within a 4 T MRI scanner under a variety of conditions. These measurement results show: (1) that noise levels can be significantly reduced through the use of an appropriately designed passive acoustic liner; and (2) the true noise levels that are experienced by patients during echo planar imaging.

  10. Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development

    Energy Technology Data Exchange (ETDEWEB)

    Gilpatrick, John D. [Los Alamos National Laboratory; Batygin, Yuri K. [Los Alamos National Laboratory; Gonzales, Fermin [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory; Kutac, Vincent G. [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Pillai, Chandra [Los Alamos National Laboratory; Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory

    2012-05-15

    The Los Alamos Neutron Science Center (LANSCE) is replacing Wire Scanner (WS) beam profile measurement systems. Three beam development tests have taken place to test the new wire scanners under beam conditions. These beam development tests have integrated the WS actuator, cable plant, electronics processors and associated software and have used H{sup -} beams of different beam energy and current conditions. In addition, the WS measurement-system beam tests verified actuator control systems for minimum profile bin repeatability and speed, checked for actuator backlash and positional stability, tested the replacement of simple broadband potentiometers with narrow band resolvers, and tested resolver use with National Instruments Compact Reconfigurable Input and Output (cRIO) Virtual Instrumentation. These beam tests also have verified how trans-impedance amplifiers react with various types of beam line background noise and how noise currents were not generated. This paper will describe these beam development tests and show some resulting data.

  11. Scanner tags, comic book piracy and participatory culture

    OpenAIRE

    Delwiche, Aaron

    2014-01-01

    To learn more about the motivations of individuals who scan and distribute comic books, this study reports findings from a content analysis of 389 scanner tags extracted from comic books posted on the torrent network Pirate Bay. Coded according to four categories linked to the literature on comic fandom and participatory culture, tags were analyzed in terms of recognition, aesthetic style, textual signifiers, and visual signifiers. Though comic book pirates seek recognition from their peers, ...

  12. Whole brain CT perfusion on a 320-slice CT scanner

    Directory of Open Access Journals (Sweden)

    Jai Jai Shiva Shankar

    2011-01-01

    Full Text Available Computed tomography perfusion (CTP has been criticized for limited brain coverage. This may result in inadequate coverage of the lesion, inadequate arterial input function, or omission of the lesion within the target perfusion volume. The availability of 320-slice CT scanners offers whole brain coverage. This minimizes the chances of misregistration of lesions regardless of location, and makes the selection of the arterial input function easy. We present different clinical scenarios in which whole brain CTP is especially useful.

  13. Software platform for simulation of a prototype proton CT scanner.

    Science.gov (United States)

    Giacometti, Valentina; Bashkirov, Vladimir A; Piersimoni, Pierluigi; Guatelli, Susanna; Plautz, Tia E; Sadrozinski, Hartmut F-W; Johnson, Robert P; Zatserklyaniy, Andriy; Tessonnier, Thomas; Parodi, Katia; Rosenfeld, Anatoly B; Schulte, Reinhard W

    2017-03-01

    Proton computed tomography (pCT) is a promising imaging technique to substitute or at least complement x-ray CT for more accurate proton therapy treatment planning as it allows calculating directly proton relative stopping power from proton energy loss measurements. A proton CT scanner with a silicon-based particle tracking system and a five-stage scintillating energy detector has been completed. In parallel a modular software platform was developed to characterize the performance of the proposed pCT. The modular pCT software platform consists of (1) a Geant4-based simulation modeling the Loma Linda proton therapy beam line and the prototype proton CT scanner, (2) water equivalent path length (WEPL) calibration of the scintillating energy detector, and (3) image reconstruction algorithm for the reconstruction of the relative stopping power (RSP) of the scanned object. In this work, each component of the modular pCT software platform is described and validated with respect to experimental data and benchmarked against theoretical predictions. In particular, the RSP reconstruction was validated with both experimental scans, water column measurements, and theoretical calculations. The results show that the pCT software platform accurately reproduces the performance of the existing prototype pCT scanner with a RSP agreement between experimental and simulated values to better than 1.5%. The validated platform is a versatile tool for clinical proton CT performance and application studies in a virtual setting. The platform is flexible and can be modified to simulate not yet existing versions of pCT scanners and higher proton energies than those currently clinically available. © 2017 American Association of Physicists in Medicine.

  14. Building a 3D scanner system based on monocular vision.

    Science.gov (United States)

    Zhang, Zhiyi; Yuan, Lin

    2012-04-10

    This paper proposes a three-dimensional scanner system, which is built by using an ingenious geometric construction method based on monocular vision. The system is simple, low cost, and easy to use, and the measurement results are very precise. To build it, one web camera, one handheld linear laser, and one background calibration board are required. The experimental results show that the system is robust and effective, and the scanning precision can be satisfied for normal users.

  15. Determining the surface roughness coefficient by 3D Scanner

    Directory of Open Access Journals (Sweden)

    Karmen Fifer Bizjak

    2010-12-01

    Full Text Available Currently, several test methods can be used in the laboratory to determine the roughness of rock joint surfaces.However, true roughness can be distorted and underestimated by the differences in the sampling interval of themeasurement methods. Thus, these measurement methods produce a dead zone and distorted roughness profiles.In this paper a new rock joint surface roughness measurement method is presented, with the use of a camera-typethree-dimensional (3D scanner as an alternative to current methods. For this study, the surfaces of ten samples oftuff were digitized by means of a 3D scanner, and the results were compared with the corresponding Rock JointCoefficient (JRC values. Up until now such 3D scanner have been mostly used in the automotive industry, whereastheir use for comparison with obtained JRC coefficient values in rock mechanics is presented here for the first time.The proposed new method is a faster, more precise and more accurate than other existing test methods, and is apromising technique for use in this area of study in the future.

  16. An endoscopic 3D scanner based on structured light.

    Science.gov (United States)

    Schmalz, Christoph; Forster, Frank; Schick, Anton; Angelopoulou, Elli

    2012-07-01

    We present a new endoscopic 3D scanning system based on Single Shot Structured Light. The proposed design makes it possible to build an extremely small scanner. The sensor head contains a catadioptric camera and a pattern projection unit. The paper describes the working principle and calibration procedure of the sensor. The prototype sensor head has a diameter of only 3.6mm and a length of 14mm. It is mounted on a flexible shaft. The scanner is designed for tubular cavities and has a cylindrical working volume of about 30mm length and 30mm diameter. It acquires 3D video at 30 frames per second and typically generates approximately 5000 3D points per frame. By design, the resolution varies over the working volume, but is generally better than 200μm. A prototype scanner has been built and is evaluated in experiments with phantoms and biological samples. The recorded average error on a known test object was 92μm.

  17. Efficient system modeling for a small animal PET scanner with tapered DOI detectors.

    Science.gov (United States)

    Zhang, Mengxi; Zhou, Jian; Yang, Yongfeng; Rodríguez-Villafuerte, Mercedes; Qi, Jinyi

    2016-01-21

    A prototype small animal positron emission tomography (PET) scanner for mouse brain imaging has been developed at UC Davis. The new scanner uses tapered detector arrays with depth of interaction (DOI) measurement. In this paper, we present an efficient system model for the tapered PET scanner using matrix factorization and a virtual scanner geometry. The factored system matrix mainly consists of two components: a sinogram blurring matrix and a geometrical matrix. The geometric matrix is based on a virtual scanner geometry. The sinogram blurring matrix is estimated by matrix factorization. We investigate the performance of different virtual scanner geometries. Both simulation study and real data experiments are performed in the fully 3D mode to study the image quality under different system models. The results indicate that the proposed matrix factorization can maintain image quality while substantially reduce the image reconstruction time and system matrix storage cost. The proposed method can be also applied to other PET scanners with DOI measurement.

  18. Fibre-optical microendoscopy.

    Science.gov (United States)

    Gu, M; Bao, H; Kang, H

    2014-04-01

    Microendoscopy has been an essential tool in exploring micro/nano mechanisms in vivo due to high-quality imaging performance, compact size and flexible movement. The investigations into optical fibres, micro-scanners and miniature lens have boosted efficiencies of remote light delivery to sample site and signal collection. Given the light interaction with materials in the fluorescence imaging regime, this paper reviews two classes of compact microendoscopy based on a single fibre: linear optical microendoscopy and nonlinear optical microendoscopy. Due to the fact that fluorescence occurs only in the focal volume, nonlinear optical microendoscopy can provide stronger optical sectioning ability than linear optical microendoscopy, and is a good candidate for deep tissue imaging. Moreover, one-photon excited fluorescence microendoscopy as the linear optical microendoscopy suffers from severe photobleaching owing to the linear dependence of photobleaching rate on excitation laser power. On the contrary, nonlinear optical microendoscopy, including two-photon excited fluorescence microendoscopy and second harmonic generation microendoscopy, has the capability to minimize or avoid the photobleaching effect at a high excitation power and generate high image contrast. The combination of various nonlinear signals gained by the nonlinear optical microendoscopy provides a comprehensive insight into biophenomena in internal organs. Fibre-optical microendoscopy overcomes physical limitations of traditional microscopy and opens up a new path to achieve early cancer diagnosis and microsurgery in a minimally invasive and localized manner.

  19. Analysis of adaptive laser scanning optical system with focus-tunable components

    Science.gov (United States)

    Pokorný, P.; Mikš, A.; Novák, J.; Novák, P.

    2015-05-01

    This work presents a primary analysis of an adaptive laser scanner based on two-mirror beam-steering device and focustunable components (lenses with tunable focal length). It is proposed an optical scheme of an adaptive laser scanner, which can focus the laser beam in a continuous way to a required spatial position using the lens with tunable focal length. This work focuses on a detailed analysis of the active optical or opto-mechanical components (e.g. focus-tunable lenses) mounted in the optical systems of laser scanners. The algebraic formulas are derived for ray tracing through different configurations of the scanning optical system and one can calculate angles of scanner mirrors and required focal length of the tunable-focus component provided that the position of the focused beam in 3D space is given with a required tolerance. Computer simulations of the proposed system are performed using MATLAB.

  20. Effective duty cycle of galvanometer-based scanners: impact on OCT imaging

    Science.gov (United States)

    Duma, Virgil-Florin; Tankam, Patrice; Huang, Jinxin; Won, Jungeun; Rolland, Jannick P.

    2015-03-01

    We study experimentally the scanning functions of galvanometer-based scanners (GSs) in order to optimize them for biomedical imaging in general, and for Optical Coherence Tomography (OCT) in particular. The main scanning parameters of the scanning process are taken into account: theoretical duty cycle (of the input signal of the GS), scan frequency (fs), and scan amplitude (θm). Triangular to sawtooth scanning regimes are thus considered. We demonstrate that when increasing the scan frequency and amplitude, the scanning function (i.e., the angular position of the galvomirror) is not able to follow anymore the input signal. Furthermore, as the theoretical duty cycle is increased, the result is unexpected: the effective duty cycle actually decreases - for high fs and θm. A saturation of the device therefore occurs. The practical limits of this phenomenon are discussed. GS users are thus provided with a multi-parameter analysis that allows them for optimizing their scanning regimes and to avoid pushing the devices to their limit - when that actually results in decreasing the quality of the images obtained, by example in OCT. Gabor Domain Optical Coherence Microscopy (GD-OCM) images are made to show effects of this phenomenon.

  1. Comparison of three-dimensional scanner systems for craniomaxillofacial imaging.

    Science.gov (United States)

    Knoops, Paul G M; Beaumont, Caroline A A; Borghi, Alessandro; Rodriguez-Florez, Naiara; Breakey, Richard W F; Rodgers, William; Angullia, Freida; Jeelani, N U Owase; Schievano, Silvia; Dunaway, David J

    2017-04-01

    Two-dimensional photographs are the standard for assessing craniofacial surgery clinical outcomes despite lacking three-dimensional (3D) depth and shape. Therefore, 3D scanners have been gaining popularity in various fields of plastic and reconstructive surgery, including craniomaxillofacial surgery. Head shapes of eight adult volunteers were acquired using four 3D scanners: 1.5T Avanto MRI, Siemens; 3dMDface System, 3dMD Inc.; M4D Scan, Rodin4D; and Structure Sensor, Occipital Inc. Accuracy was evaluated as percentage of data within a range of 2 mm from the 3DMDface System reconstruction, by surface-to-surface root mean square (RMS) distances, and with facial distance maps. Precision was determined by RMS. Relative to the 3dMDface System, accuracy was the highest for M4D Scan (90% within 2 mm; RMS of 0.71 mm ± 0.28 mm), followed by Avanto MRI (86%; 1.11 mm ± 0.33 mm) and Structure Sensor (80%; 1.33 mm ± 0.46). M4D Scan and Structure Sensor precision were 0.50 ± 0.04 mm and 0.51 ± 0.03 mm, respectively. Clinical and technical requirements govern scanner choice; however, 3dMDface System and M4D Scan provide high-quality results. It is foreseeable that compact, handheld systems will become more popular in the near future.

  2. Comparative evaluation of ultrasound scanner accuracy in distance measurement

    Science.gov (United States)

    Branca, F. P.; Sciuto, S. A.; Scorza, A.

    2012-10-01

    The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

  3. Compact implementation of dynamic receive apodization in ultrasound scanners

    DEFF Research Database (Denmark)

    Tomov, Borislav Gueorguiev; Jensen, Jørgen Arendt

    2004-01-01

    The image quality in medical ultrasound scanners is determined by several factors, one of which is the ability of the receive beamformer to change the aperture weighting function with depth and beam angle. In digital beamformers, precise dynamic apodization can be achieved by representing...... the function by numeric sequences. For a 15 cm scan depth and 100 lines per image, a 64-channel, 40 MHz ultrasound beamformer may need almost 50 million coefficients. A more coarse representation of the aperture relieves the memory requirements but does not enable compact and precise beamforming. Previously...

  4. Detective quantum efficiency (DQE) in PET scanners: A simulation study.

    Science.gov (United States)

    Karpetas, George E; Michail, Christos M; Fountos, George P; Kalyvas, Nektarios I; Valais, Ioannis G; Kandarakis, Ioannis S; Panayiotakis, George S

    2017-07-01

    The aim of the present study is to introduce the detective quantum efficiency (DQE) for the image quality assessment of positron emission tomography (PET) scanners. For this purpose, a thin layer chromatography (TLC) plane source was simulated using a previously validated, scanner and source geometry, Monte Carlo (MC) model. The model was developed with the Geant4 application for tomographic emission (GATE) MC package and reconstructed images obtained with the software for tomographic image reconstruction (STIR), with cluster computing. The GE Discovery ST PET scanner was simulated by using a previously validated code. A plane source consisting of a TLC plate, was simulated by a layer of silica gel on aluminum (Al) foil substrate, immersed in 18F-FDG bath solution (1MBq). Image quality was assessed in terms of the modulation transfer function (MTF) and the normalized noise power spectrum (NNPS) in order to obtain the detective quantum efficiency (DQE). MTF curves were estimated from transverse reconstructed images of the plane source, whereas the NNPS data were estimated from the corresponding coronal images. Images were reconstructed by the maximum likelihood estimation ordered subsets maximum a posteriori one step late (MLE)-OS-MAP-OSL algorithm, by using various subsets 1-21) and iterations 1-20). MTF values were found to increase up to the 12th iteration whereas remain almost constant thereafter. However, the range of the increase in the MTF is limited as the number of subsets increases. The noise levels were found to increase with the corresponding increase of both the number of iterations and subsets. The maximum NNPS value (0.517mm(2)) was observed for the 420 MLEM-equivalent iterations reconstructed image at 0cycles/mm. Finally DQE values were found to increase for spatial frequencies up to 0.038cycles/mm and to decrease thereafter with the corresponding increase in both number of iterations and subsets. The maximum DQE value (0.48 at 0.038cycles/mm) was

  5. Investigation of a near-infrared-ray computed tomography scanner

    Science.gov (United States)

    Sato, Eiichi; Oda, Yasuyuki; Satoi, Yuichi; Yamaguchi, Satoshi; Ishii, Tomotaka; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Watanabe, Manabu; Kusachi, Shinya

    2016-10-01

    In the near-infrared-ray computed tomography (NIR-CT) scanner, NIR rays are produced from a light-emitting diode (LED) and detected using an NIR phototransistor (PT). The wavelengths of the LED peak intensity and the PT high sensitivity in the data table are both 940 nm. The photocurrents flowing through the PTR are converted into voltages using an emitter-follower circuit, and the output voltages are sent to a personal computer through an analog-digital converter. The NIR projection curves for tomography are obtained by repeated linear scans and rotations of the object, and the scanning is conducted in both directions of its movement.

  6. Performance evaluation of an Inveon PET preclinical scanner

    Science.gov (United States)

    Constantinescu, Cristian C.; Mukherjee, Jogeshwar

    2009-05-01

    We evaluated the performance of an Inveon preclinical PET scanner (Siemens Medical Solutions), the latest MicroPET system. Spatial resolution was measured with a glass capillary tube (0.26 mm inside diameter, 0.29 mm wall thickness) filled with 18F solution. Transaxial and axial resolutions were measured with the source placed parallel and perpendicular to the axis of the scanner. The sensitivity of the scanner was measured with a 22Na point source, placed on the animal bed and positioned at different offsets from the center of the field of view (FOV), as well as at different energy and coincidence windows. The noise equivalent count rates (NECR) and the system scatter fraction were measured using rat-like (Φ = 60, L = 150 mm) and mouse-like (Φ = 25 mm, L = 70 mm) cylindrical phantoms. Line sources filled with high activity 18F (>250 MBq) were inserted parallel to the axes of the phantoms (13.5 and 10 mm offset). For each phantom, list-mode data were collected over 24 h at 350-650 keV and 250-750 keV energy windows and 3.4 ns coincidence window. System scatter fraction was measured when the random event rates were below 1%. Performance phantoms consisting of cylinders with hot rod inserts filled with 18F were imaged. In addition, we performed imaging studies that show the suitability of the Inveon scanner for imaging small structures such as those in mice with a variety of tracers. The radial, tangential and axial resolutions at the center of FOV were 1.46 mm, 1.49 and 1.15 mm, respectively. At a radial offset of 2 cm, the FWHM values were 1.73, 2.20 and 1.47 mm, respectively. At a coincidence window of 3.4 ns, the sensitivity was 5.75% for EW = 350-650 keV and 7.4% for EW = 250-750 keV. For an energy window of 350-650 keV, the peak NECR was 538 kcps at 131.4 MBq for the rat-like phantom, and 1734 kcps at 147.4 MBq for the mouse-like phantom. The system scatter fraction values were 0.22 for the rat phantom and 0.06 for the mouse phantom. The Inveon system

  7. Analysis framework for the J-PET scanner

    CERN Document Server

    Krzemień, W; Gruntowski, A; Stola, K; Trybek, D; Bednarski, T; Białas, P; Czerwiński, E; Kamińska, D; Kapłon, L; Kochanowski, A; Korcyl, G; Kowal, J; Kowalski, P; Kozik, T; Kubicz, E; Moskal, P; Niedźwiecki, Sz; Pałka, M; Raczyński, L; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; Słomski, A; Smyrski, J; Strzelecki, A; Wieczorek, A; Wiślicki, W; Zieliński, M; Zoń, N

    2015-01-01

    J-PET analysis framework is a flexible, lightweight, ROOT-based software package which provides the tools to develop reconstruction and calibration procedures for PET tomography. In this article we present the implementation of the full data-processing chain in the J-PET framework which is used for the data analysis of the J-PET tomography scanner. The Framework incorporates automated handling of PET setup parameters' database as well as high level tools for building data reconstruction procedures. Each of these components is briefly discussed.

  8. Scatter fraction of the J-PET tomography scanner

    CERN Document Server

    Kowalski, P; Raczyński, L; Alfs, D; Bednarski, T; Białas, P; Czerwiński, E; Gajos, A; Głowacz, B; Jasińska, J; Kamińska, D; Korcyl, G; Kozik, T; Krzemień, W; Kubicz, E; Mohammad, M; Niedźwiecki, Sz; Pałka, M; Pawlik-Niedźwiecka, M; Rudy, Z; Silarski, M; Smyrski, J; Strzelecki, A; Wieczorek, A; Zgardzińska, B; Zieliński, M; Moskal, P

    2016-01-01

    A novel Positron Emission Tomography system, based on plastic scintillators, is being developed by the J-PET collaboration. In this article we present the simulation results of the scatter fraction, representing one of the parameters crucial for background studies defined in the NEMA-NU-2-2012 norm. We elaborate an event selection methods allowing to suppress events in which gamma quanta were scattered in the phantom or underwent the multiple scattering in the detector. The estimated scatter fraction for the single-layer J-PET scanner varies from 37% to 53% depending on the applied energy threshold.

  9. Demonstration: A smartphone 3D functional brain scanner

    DEFF Research Database (Denmark)

    Stahlhut, Carsten; Stopczynski, Arkadiusz; Larsen, Jakob Eg

    We demonstrate a fully portable 3D real-time functional brain scanner consisting of a wireless 14-channel ‘Neuroheadset‘ (Emotiv EPOC) and a Nokia N900 smartphone. The novelty of our system is the ability to perform real-time functional brain imaging on a smartphone device, including stimulus...... tools are preferred. Source localization is implemented locally on the phone with a 3D brain model consisting of 1,028 vertices and 2,048 triangles stored in the mobile application. Our system design benefits from the possibility of being able to integrate with multiple hardware platforms (smartphones...

  10. A new electronic read-out for the YAPPET scanner

    CERN Document Server

    Damiani, C; Malaguti, R; Guerra, A D; Domenico, G D; Zavattini, G

    2002-01-01

    A small animal PET-SPECT scanner (YAPPET) prototype was built at the Physics Department of the Ferrara University and is presently being used at the Nuclear Medicine Department for radiopharmaceutical studies on rats. The first YAPPET prototype shows very good performances, but needs some improvements before it can be fully used for intensive radiopharmaceutical research. The main problem of the actual prototype is its heavy electronics, based on NIM and CAMAC standard modules. For this reason a new, compact read-out electronics was developed and tested. The results of a first series of tests made on the first prototype will be presented in the paper.

  11. Comparison of back side chrome focus monitor to focus self-metrology of an immersion scanner

    Science.gov (United States)

    D'havé, Koen; Machida, Takahiro; Laidler, David; Cheng, Shaunee

    2007-03-01

    Monitoring of the focus performance is recognized to be an important part of a periodic scanner health check, but can one simply apply all techniques that have been used for dry scanners to immersion scanners? And if so how do such techniques compare to scanner self-metrology tests that are used to set up the tool? In this paper we look at one specific off-line focus characterization technique, Back Side Chrome (BSC), which we then try to match with results obtained from two self-metrology focus tests, available on the scanner chosen for this work. The latter tests are also used to set up the immersion scanner. We point out a few concerns, discuss their effect and indicate that for each generation of immersion tool one should redo the entire exercise.

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

    Science.gov (United States)

    Shi, Jinlong; Sun, Zhengxing; Bai, Suqin

    2015-04-01

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

  13. Irradiation in helical scanner: doses estimation, parameters choice; Irradiation en scanner helicoidal: estimation des doses, choix des parametres

    Energy Technology Data Exchange (ETDEWEB)

    Cordoliani, Y.S.; Boyer, B.; Jouan, E.; Beauvais, H

    2001-07-01

    The new generation of helical scanners improves the diagnosis abilities and the service done to the patients. The rational use allows to give the patients a ratio benefit/risk far better than the almost medical examinations. It is particularly true for over sixty years old aged people, that have a null genetic risk and a practically null carcinogen risk; However, for young adults and children, it is necessary to banish any useless irradiation and limit exposure to the strict necessary for the diagnosis. It is necessary to develop a radiation protection culture, possible by the radiation doses index display and doses benchmarks knowledge. (N.C.)

  14. Deformation Measurement Using Terrestrial Laser Scanner for Cultural Heritage

    Science.gov (United States)

    Selbesoglu, M. O.; Bakirman, T.; Gokbayrak, O.

    2016-10-01

    Historical structures are one of the most essential element of cultural heritage. They reflect history, lifestyle and tradition of a country and society. However, they are damaged through the years due to human activities and natural hazards. Therefore, digital documentation of structures and monuments is critical for preservation, sustainability and protection of cultural heritage. Terrestrial laser scanner is a widespread used tool for obtaining 3D representation of real world. In this study, we aimed to measure deformation of deformed minaret of a historical mosque using terrestrial laser scanner. In order to represent the geometry of the deformed minaret with high accuracy, 31 horizontal sections were created from the transition segment to the spire of the minaret with 30 cm intervals. The changing curvatures of the minaret were analysed in three parts; cylindrical part, balcony part and upper part. The offsets from the vertical axes for the parts of the minaret were found as 10.14 cm, 13.97 cm and 16.51 cm, respectively.

  15. Adaptation of Industrial Hyperspectral Line Scanner for Archaeological Applications

    Science.gov (United States)

    Miljković, V.; Gajski, D.

    2016-06-01

    The spectral characteristic of the visible light reflected from any of archaeological artefact is the result of the interaction of its surface illuminated by incident light. Every particular surface depends on what material it is made of and/or which layers put on it has its spectral signature. Recent archaeometry recognises this information as very valuable data to extend present documentation of artefacts and as a new source for scientific exploration. However, the problem is having an appropriate hyperspectral imaging system available and adopted for applications in archaeology. In this paper, we present the new construction of the hyperspectral imaging system, made of industrial hyperspectral line scanner ImSpector V9 and CCD-sensor PixelView. The hyperspectral line scanner is calibrated geometrically, and hyperspectral data are geocoded and converted to the hyperspectral cube. The system abilities are evaluated for various archaeological artefacts made of different materials. Our experience in applications, visualisations, and interpretations of collected hyperspectral data are explored and presented.

  16. Source mask optimization study based on latest Nikon immersion scanner

    Science.gov (United States)

    Zhu, Jun; Wei, Fang; Chen, Lijun; Zhang, Chenming; Zhang, Wei; Nishinaga, Hisashi; El-Sewefy, Omar; Gao, Gen-Sheng; Lafferty, Neal; Meiring, Jason; Zhang, Recoo; Zhu, Cynthia

    2016-03-01

    The 2x nm logic foundry node has many challenges since critical levels are pushed close to the limits of low k1 ArF water immersion lithography. For these levels, improvements in lithographic performance can translate to decreased rework and increased yield. Source Mask Optimization (SMO) is one such route to realize these image fidelity improvements. During SMO, critical layout constructs are intensively optimized in both the mask and source domain, resulting in a solution for maximum lithographic entitlement. From the hardware side, advances in source technology have enabled free-form illumination. The approach allows highly customized illumination, enabling the practical application of SMO sources. The customized illumination sources can be adjusted for maximum versatility. In this paper, we present a study on a critical layer of an advanced foundry logic node using the latest ILT based SMO software, paired with state-of-the-art scanner hardware and intelligent illuminator. Performance of the layer's existing POR source is compared with the ideal SMO result and the installed source as realized on the intelligent illuminator of an NSR-S630D scanner. Both simulation and on-silicon measurements are used to confirm that the performance of the studied layer meets established specifications.

  17. Commissioning of a passive rod scanner at INB

    Energy Technology Data Exchange (ETDEWEB)

    Junqueira, Fabio da Silva; Oliveira, Carlos A.; Palheiros, Franklin, E-mail: carlossilva@inb.gov.br, E-mail: franklin@inb.gov.br [Industrias Nucleares do Brasil (INB), Resende, RJ (Brazil). Superintendencia de Engenharia do Combustivel; Fernandez, Pablo Jesus Piñer, E-mail: pineiro@tecnatom.es [Tecnatom, San Sebastian de los Reyes, Madrid (Spain)

    2015-07-01

    For the 21st reload for Angra 1, a shift from Standard to Advanced fuel design will be introduced, where the fuel assemblies under the new design will contain fuel rods with axial blanket, in line with ELETRONUCLEAR's requirement for a higher energy efficient reactor fuel. Additionally, fuel rods for Angra 2 and 3, using gadolinium type burnable poison, have to be submitted to inspections due to the demand for the same type of inspection, which cannot be certified at INB currently. In keeping with CNEN regulations, every fuel-assembly component must be inspected and certified by a qualified method. Nevertheless, INB lacks the means to perform the certification-required inspection aimed at determining the uranium enrichment and presence of gadolinium pellets inside the closed rods. Hence, the use is necessary of a scanner capable of inspecting differently enriched fuel rods and/or gadolinium pellets (axial blanket). This work aims to present the recent Passive Rod Scanner installed at INB with most advance technology in the area, making possible to completely fulfill Angra 1, 2 and 3 rods inspection at INB Resende site. (author)

  18. Noninvasive thermometry with a clinical x-ray CT scanner

    Energy Technology Data Exchange (ETDEWEB)

    Fallone, B.G.; Moran, P.R.; Podgorsak, E.B.

    1982-09-01

    A CT scanner yields CT numbers which are proportional to the fractional difference in effective local electron density of the subject material with respect to that of calibration material. A homogeneous water-equivalent material is used as a calibration phantom under isothermal conditions. Any temperature variation (spatial or temporal) in the subject material subsequently scanned, will generate a CT-number shift in the CT image because of density changes due to thermal expansion. The potential use of the thermally generated CT-number shift in noninvasive thermometry during cancer hyperthermia was studied in vitro in samples of water and muscle tissue. The reproducibility of the area-averaged CT-number measurement on our EMI-7070 scanner was found to depend strongly on the time interval between successive counterclockwise scans and on the size of the region of interest used for area averaging. A linear relationship was found between the CT number and water density in the water temperature range from 10 to 55 /sup 0/C. In the hyperthermia temperature range (36--50 /sup 0/C), the relationship between the CT number and temperature itself is linear, with a CT-number thermal shift of about 0.4 and 0.45 HU//sup 0/C for water and muscle tissue, respectively. The achievable temperature discrimination is a fraction of /sup 0/C at spatial resolutions of the order of a centimeter.

  19. Operation of the preclinical head scanner for proton CT

    Science.gov (United States)

    Sadrozinski, H. F.-W.; Geoghegan, T.; Harvey, E.; Johnson, R. P.; Plautz, T. E.; Zatserklyaniy, A.; Bashkirov, V.; Hurley, R. F.; Piersimoni, P.; Schulte, R. W.; Karbasi, P.; Schubert, K. E.; Schultze, B.; Giacometti, V.

    2016-09-01

    We report on the operation and performance tests of a preclinical head scanner developed for proton computed tomography (pCT). After extensive preclinical testing, pCT is intended to be employed in support of proton therapy treatment planning and pre-treatment verification in patients undergoing particle-beam therapy. In order to assess the performance of the scanner, we have performed CT scans with 200 MeV protons from both the synchrotron of the Loma Linda University Medical Center (LLUMC) and the cyclotron of the Northwestern Medicine Chicago Proton Center (NMCPC). The very high sustained rate of data acquisition, exceeding one million protons per second, allowed a full 360° scan to be completed in less than 7 min. The reconstruction of various phantoms verified accurate reconstruction of the proton relative stopping power (RSP) and the spatial resolution in a variety of materials. The dose for an image with better than 1% uncertainty in the RSP is found to be close to 1 mGy.

  20. Operation of the preclinical head scanner for proton CT

    Energy Technology Data Exchange (ETDEWEB)

    Sadrozinski, H.F.-W., E-mail: hartmut@ucsc.edu [SCIPP, U.C. Santa Cruz, Santa Cruz, CA 95064 (United States); Geoghegan, T.; Harvey, E.; Johnson, R.P.; Plautz, T.E.; Zatserklyaniy, A. [SCIPP, U.C. Santa Cruz, Santa Cruz, CA 95064 (United States); Bashkirov, V.; Hurley, R.F.; Piersimoni, P.; Schulte, R.W. [Division of Radiation Research, Loma Linda University, Loma Linda, CA 92354 (United States); Karbasi, P.; Schubert, K.E.; Schultze, B. [School of Engineering and Computer Science, Baylor University, Waco, TX 76798 (United States); Giacometti, V. [Center for Medical Radiation Physics, University of Wollongong, NSW (Australia)

    2016-09-21

    We report on the operation and performance tests of a preclinical head scanner developed for proton computed tomography (pCT). After extensive preclinical testing, pCT is intended to be employed in support of proton therapy treatment planning and pre-treatment verification in patients undergoing particle-beam therapy. In order to assess the performance of the scanner, we have performed CT scans with 200 MeV protons from both the synchrotron of the Loma Linda University Medical Center (LLUMC) and the cyclotron of the Northwestern Medicine Chicago Proton Center (NMCPC). The very high sustained rate of data acquisition, exceeding one million protons per second, allowed a full 360° scan to be completed in less than 7 min. The reconstruction of various phantoms verified accurate reconstruction of the proton relative stopping power (RSP) and the spatial resolution in a variety of materials. The dose for an image with better than 1% uncertainty in the RSP is found to be close to 1 mGy.

  1. Towards a mechanical MPI scanner based on atomic magnetometry

    CERN Document Server

    Colombo, Simone; Tonyushkin, Alexey; Grujic, Zoran D; Dolgovskiy, Vladimir; Weis, Antoine

    2016-01-01

    We report on our progress in the development of an atomic magnetometer (AM) based low-frequency X-space MPI scanner, expected to be free from SAR and PNS constraints. We address major challenges in coil and sensor design due to specificAMproperties. Compared to our previous workwe have changed the AM's mode of operation towards its implementation for detecting weak SPIO response fields in the presence of nearby-located strong drive/selection fields. We demonstrate that a pump-probe AM scheme in a buffer gas filled alkali vapour cell can tolerate mT/m gradients while maintaining a sensitivity in the one-digit pT/Hz^(1/2) range over a bandwidth from DC to several kHz. We give a detailed description of the drive/selection coils' geometry and their hardware implementations that will provide both field-free-line (FFL) and field-free-point (FFP) modes of operation, compatible with a best performance AM operation. We estimate the achievable field of view and spatial resolution of the scanner as well as its sensitivi...

  2. The accuracy of the CAD system using intraoral and extraoral scanners for designing of fixed dental prostheses.

    Science.gov (United States)

    Shimizu, Sakura; Shinya, Akikazu; Kuroda, Soichi; Gomi, Harunori

    2017-07-26

    The accuracy of prostheses affects clinical success and is, in turn, affected by the accuracy of the scanner and CAD programs. Thus, their accuracy is important. The first aim of this study was to evaluate the accuracy of an intraoral scanner with active triangulation (Cerec Omnicam), an intraoral scanner with a confocal laser (3Shape Trios), and an extraoral scanner with active triangulation (D810). The second aim of this study was to compare the accuracy of the digital crowns designed with two different scanner/CAD combinations. The accuracy of the intraoral scanners and extraoral scanner was clinically acceptable. Marginal and internal fit of the digital crowns fabricated using the intraoral scanner and CAD programs were inferior to those fabricated using the extraoral scanner and CAD programs.

  3. Improving CT scan capabilities with a new trauma workflow concept: Simulation of hospital logistics using different CT scanner scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Fung Kon Jin, P.H.P., E-mail: p.fungkonjin@amc.uva.nl [Trauma Unit Department of Surgery, Academic Medical Center, Amsterdam (Netherlands); Dijkgraaf, M.G.W., E-mail: m.dijkgraaf@amc.uva.nl [Department of Clinical Epidemiology, Biostatistics, and Bioinformatics, Academic Medical Center, Amsterdam (Netherlands); Alons, C.L., E-mail: clalons@few.vu.nl [Department of Mathematics, VU University Amsterdam, Amsterdam (Netherlands); Kuijk, C. van, E-mail: c.vankuijk@vumc.nl [Department of Radiology, VU Medical Center, Amsterdam (Netherlands); Beenen, L.F.M., E-mail: l.beenen@amc.uva.nl [Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Koole, G.M., E-mail: koole@few.vu.nl [Department of Mathematics, VU University Amsterdam, Amsterdam (Netherlands); Goslings, J.C., E-mail: j.c.goslings@amc.uva.nl [Trauma Unit Department of Surgery, Academic Medical Center, Amsterdam (Netherlands)

    2011-11-15

    Introduction: The Amsterdam Trauma Workflow (ATW) concept includes a sliding gantry CT scanner serving two mirrored (trauma) rooms. In this study, several predefined scenarios with a varying number of CT scanners and CT locations are analyzed to identify the best performing patient flow management strategy from an institutional perspective on process quality. Materials and methods: A total of six clinically relevant scenarios with variables that included the number of CT scanners, CT scanner location, and different patient categories (regular, urgent, and trauma patients) were evaluated using computer simulation. Each scenario was simulated using institutional data and was assessed for patient waiting times, idle time of CT scanners, and overtime due to scheduling. The best 2- and 3-scanner scenarios were additionally evaluated with the ATW-concept. Results: Based on institutional data, the best 2-scanner scenario distributes all 3 patient categories over both scanners and plans 4 urgent patients per hour while locating both scanners outside of the trauma room. The best 3-scanner scenario distributes urgent and regular patients over all 3 scanners and trauma patients on only 1 scanner and locates all CT scanners outside of the trauma room. The ATW concept reduces waiting times and overtime, while increasing idle time. Conclusion: Choosing the optimal planning and distribution strategies depends on the number and location of available CT scanners, along with number of trauma, urgent and regular patients. The Amsterdam Trauma Workflow concept could provide institutions with the ability of early CT scanning in trauma patients without influencing regular and urgent CT scanning.

  4. Monte Carlo simulation of sensitivity and NECR of an entire-body PET scanner.

    Science.gov (United States)

    Isnaini, Ismet; Obi, Takashi; Yoshida, Eiji; Yamaya, Taiga

    2014-07-01

    The current positron emission tomography (PET) design is aimed toward establishing an entire-body PET scanner. An entire-body PET scanner is a scanner whose axial field of view (FOV) covers the whole body of a patient, whereas whole-body PET scanner can be of any axial FOV length, but was designed for a whole-body scan. Despite its high production cost, an entire-body depth-of-interaction PET scanner offers many benefits, such as shorter and dynamic PET time acquisition, as well as higher sensitivity and count rate performance. This PET scanner may be cost-effective for clinical PET scanners with high scan throughput. In this work, we evaluated the sensitivity and count rate performance of a 2-m-long PET scanner with conventional data acquisition (DAQ) architecture, using Monte Carlo simulation, and we evaluated two ring diameters (60 and 80 cm) to reduce the scanner cost. From simulation of scanning with a 2-m axial FOV, the sensitivity for a 2-m-long PET scanner of 60 and 80-cm diameter is around 80 and 68 times higher, respectively, than that of the conventional PET scanner. In addition, for the 2-m-long PET scanner with 60-cm diameter, the peak noise equivalent count rate (NECR) was 843 kcps at 125 MBq, whereas the peak for the 80-cm diameter was 989 kcps at 200 MBq. This shows gains of 15.3 and 17.95, respectively, in comparison with that of the conventional PET scanner. The 2-m-long PET scanner with 60-cm ring diameter could not only reduce the number of detectors by 21 %, but also had a 17 % higher sensitivity compared to that with an 80-cm ring diameter. On the other hand, despite the higher sensitivity, the NECR of the 60-cm ring diameter was smaller than that of the 80-cm ring diameter. This results from the single data loss due to dead time, whereas grouping of axially stacked detectors was used in the conventional DAQ architecture. Parallelization of the DAQ architecture is therefore important for the 2-m-long PET scanner to achieve its optimal

  5. Optics/Optical Diagnostics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Optics/Optical Diagnostics Laboratory supports graduate instruction in optics, optical and laser diagnostics and electro-optics. The optics laboratory provides...

  6. Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner.

    Directory of Open Access Journals (Sweden)

    Ryutaro Kakinuma

    Full Text Available The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT scanners.This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from both scanners were reconstructed at 0.1-mm intervals; the slice thickness was 0.25 mm for the U-HRCT scanner and 0.5 mm for the C-HRCT scanners. For both scanners, the display field of view was 80 mm. The image noise of each scanner was evaluated using a phantom. U-HRCT and C-HRCT images of 53 images selected from 37 lung nodules were then observed and graded using a 5-point score by 10 board-certified thoracic radiologists. The images were presented to the observers randomly and in a blinded manner.The image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU] was greater than that for C-HRCT (40.41 ± 0.52 HU; P < .0001. The image quality of U-HRCT was graded as superior to that of C-HRCT (P < .0001 for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary vessels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures.Despite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners.

  7. Quantitative evaluation of three-dimensional facial scanners measurement accuracy for facial deformity

    Science.gov (United States)

    Zhao, Yi-jiao; Xiong, Yu-xue; Sun, Yu-chun; Yang, Hui-fang; Lyu, Pei-jun; Wang, Yong

    2015-07-01

    Objective: To evaluate the measurement accuracy of three-dimensional (3D) facial scanners for facial deformity patients from oral clinic. Methods: 10 patients in different types of facial deformity from oral clinical were included. Three 3D digital face models for each patient were obtained by three facial scanners separately (line laser scanner from Faro for reference, stereophotography scanner from 3dMD and structured light scanner from FaceScan for test). For each patient, registration based on Iterative Closest Point (ICP) algorithm was executed to align two test models (3dMD data & Facescan data) to the reference models (Faro data in high accuracy) respectively. The same boundaries on each pair models (one test and one reference models) were obtained by projection function in Geomagic Stuido 2012 software for trimming overlapping region, then 3D average measurement errors (3D errors) were calculated for each pair models also by the software. Paired t-test analysis was adopted to compare the 3D errors of two test facial scanners (10 data for each group). 3D profile measurement accuracy (3D accuracy) that is integrated embodied by average value and standard deviation of 10 patients' 3D errors were obtained by surveying analysis for each test scanner finally. Results: 3D accuracies of 2 test facial scanners in this study for facial deformity were 0.44+/-0.08 mm and 0.43+/-0.05 mm. The result of structured light scanner was slightly better than stereophotography scanner. No statistical difference between them. Conclusions: Both test facial scanners could meet the accuracy requirement (0.5mm) of 3D facial data acquisition for oral clinic facial deformity patients in this study. Their practical measurement accuracies were all slightly lower than their nominal accuracies.

  8. Vegetated landslide monitoring: target tracking with terrestrial laser scanner

    Science.gov (United States)

    Franz, Martin; Carrea, Dario; Abellan, Antonio; Derron, Marc-Henri; Jaboyedoff, Michel

    2013-04-01

    Monitoring landslides with terrestrial LiDAR is currently a well-known technique. One problem often encountered is the vegetation that produces shadow areas on the scans. Indeed, the points behind the obstacle are hidden and are absent from the point cloud. Thereby, locations monitored with terrestrial laser scanner are mostly rock instabilities and few vegetated landslides, being difficult or even impossible to survey vegetated slopes using this method. The Peney landslide (Geneva, Switzerland) is partially vegetated by bushes and trees, and in order to monitor its displacements during the drawdown of the Verbois reservoir located at its base, which activates the movement, an alternative solution has to be found. The Goal of this study are: (1) to illustrate a technique to monitor vegetated landslides with a terrestrial laser scanner and (2) to compare the both manual and automatic methods for displacement vectors extraction. We installed 14 targets, four of which are in stable areas which are considered as references. Targets are made of expanded polystyrene, two are spherical and 12 are cubic. They were installed on metallic poles ranging between 2 to 4 meters high. The LiDAR device was located on a fixed point on a pontoon on the reservoir opposite bank. The whole area, including the targets, needed three scans to be entirely covered and was scanned 10 times along on two weeks (duration of drawdown - filling). The acquired point clouds were cleaned and georeferenced. In order to determine the displacements for every target, two methods (manual and automatic) were used. The manual method consists on manual selection of, for example, the apex of the cubes, and so to have its 3D coordinates for a comparison in time. The automatic method uses an algorithm that recognises shapes trough time series. The obtained displacements were compared with classical measurement methods (theodolite and extensometer) showing good resemblance of results, indicating the validity of

  9. Design, construction, characterization, and application of a hyperspectral microarray scanner.

    Science.gov (United States)

    Sinclair, Michael B; Timlin, Jerilyn A; Haaland, David M; Werner-Washburne, Margaret

    2004-04-01

    We describe the design, construction, and operation of a hyperspectral microarray scanner for functional genomic research. The hyperspectral instrument operates with spatial resolutions ranging from 3 to 30 microm and records the emission spectrum between 490 and 900 nm with a spectral resolution of 3 nm for each pixel of the microarray. This spectral information, when coupled with multivariate data analysis techniques, allows for identification and elimination of unwanted artifacts and greatly improves the accuracy of microarray experiments. Microarray results presented in this study clearly demonstrate the separation of fluorescent label emission from the spectrally overlapping emission due to the underlying glass substrate. We also demonstrate separation of the emission due to green fluorescent protein expressed by yeast cells from the spectrally overlapping autofluorescence of the yeast cells and the growth media.

  10. Vibration measurements of a wire scanner - Experimental setup and models

    Science.gov (United States)

    Herranz, Juan; Barjau, Ana; Dehning, Bernd

    2016-03-01

    In the next years the luminosity of the LHC will be significantly increased. This will require a much higher accuracy of beam profile measurement than actually achievable by the current wire scanner. The new performance demands a wire travelling speed up to 20 m s-1 and a position measurement accuracy of the order of 1 μm. The vibrations of the mechanical parts of the system and particularly the vibrations of the thin carbon wire have been identified as the major error sources of wire position uncertainty. Therefore the understanding of the wire vibrations has been given high priority for the design and operation of the new device. This article presents a new strategy to measure the wire vibrations based on the piezoresistive effect of the wire itself. An electronic readout system based on a Wheatstone bridge is used to measure the variation of the carbon wire resistance, which is directly proportional to the wire elongation caused by the oscillations.

  11. An intensity-based stochastic model for terrestrial laser scanners

    Science.gov (United States)

    Wujanz, D.; Burger, M.; Mettenleiter, M.; Neitzel, F.

    2017-03-01

    Up until now no appropriate models have been proposed that are capable to describe the stochastic characteristics of reflectorless rangefinders - the key component of terrestrial laser scanners. This state has to be rated as unsatisfactory especially from the perception of Geodesy where comprehensive knowledge about the precision of measurements is of vital importance, for instance to weigh individual observations or to reveal outliers. In order to tackle this problem, a novel intensity-based stochastic model for the reflectorless rangefinder of a Zoller + Fröhlich Imager 5006 h is experimentally derived. This model accommodates the influence of the interaction between the emitted signal and object surface as well as the acquisition configuration on distance measurements. Based on two different experiments the stochastic model has been successfully verified for three chosen sampling rates.

  12. Modeling of estuarne chlorophyll a from an airborne scanner

    Science.gov (United States)

    Khorram, Siamak; Catts, Glenn P.; Cloern, James E.; Knight, Allen W.

    1987-01-01

    Near simultaneous collection of 34 surface water samples and airborne multispectral scanner data provided input for regression models developed to predict surface concentrations of estuarine chlorophyll a. Two wavelength ratios were employed in model development. The ratios werechosen to capitalize on the spectral characteristics of chlorophyll a, while minimizing atmospheric influences. Models were then applied to data previously acquired over the study area thre years earlier. Results are in the form of color-coded displays of predicted chlorophyll a concentrations and comparisons of the agreement among measured surface samples and predictions basedon coincident remotely sensed data. The influence of large variations in fresh-water inflow to the estuary are clearly apparent in the results. The synoptic view provided by remote sensing is another method of examining important estuarine dynamics difficult to observe from in situ sampling alone.

  13. Crop water-stress assessment using an airborne thermal scanner

    Science.gov (United States)

    Millard, J. P.; Jackson, R. D.; Reginato, R. J.; Idso, S. B.; Goettelman, R. C.

    1978-01-01

    An airborne thermal scanner was used to measure the temperature of a wheat crop canopy in Phoenix, Arizona. The results indicate that canopy temperatures acquired about an hour and a half past solar noon were well correlated with presunrise plant water tension, a parameter directly related to plant growth and development. Pseudo-colored thermal images reading directly in stress degree days, a unit indicative of crop irrigation needs and yield potential, were produced. The aircraft data showed significant within-field canopy temperature variability, indicating the superiority of the synoptic view provided by aircraft over localized ground measurements. The standard deviation between airborne and ground-acquired canopy temperatures was 2 C or less.

  14. Detector characterization for an inline PET scanner in hadrontherapy

    Energy Technology Data Exchange (ETDEWEB)

    Taverne, Marina [IPNL, Universite Claude Bernard Lyon 1, 4 rue Enrico Fermi, 69100 Villeurbanne (France); Boutemeur, Madjid [IPNL, Universite Claude Bernard Lyon 1, 4 rue Enrico Fermi, 69100 Villeurbanne (France); Buthod, Anthony [IPNL, Universite Claude Bernard Lyon 1, 4 rue Enrico Fermi, 69100 Villeurbanne (France); Guigues, Laurent [CREATIS, INSA Lyon, avenue Albert Einstein, 69100 Villeurbanne (France); Henriquet, Pierre [IPNL, Universite Claude Bernard Lyon 1, 4 rue Enrico Fermi, 69100 Villeurbanne (France); Lollierou, Julien [IPNL, Universite Claude Bernard Lyon 1, 4 rue Enrico Fermi, 69100 Villeurbanne (France); Ricol, Marie-Charlotte [IPNL, Universite Claude Bernard Lyon 1, 4 rue Enrico Fermi, 69100 Villeurbanne (France); Rosset-Lanchet, Remi [IPNL, Universite Claude Bernard Lyon 1, 4 rue Enrico Fermi, 69100 Villeurbanne (France); Roubin, Mathieu [IPNL, Universite Claude Bernard Lyon 1, 4 rue Enrico Fermi, 69100 Villeurbanne (France); Saidi, Reda [IPNL, Universite Claude Bernard Lyon 1, 4 rue Enrico Fermi, 69100 Villeurbanne (France); Sappey-Marinier, Dominique [CREATIS, INSA Lyon, avenue Albert Einstein, 69100 Villeurbanne (France); Testa, Etienne [IPNL, Universite Claude Bernard Lyon 1, 4 rue Enrico Fermi, 69100 Villeurbanne (France)]. E-mail: taverne@ipnl.in2p3.fr

    2007-02-01

    Our group at the 'Institut de Physique Nucleaire de Lyon' (IPNL) is working on physics and detectors for medical imaging. We are presently developing a small animal Positron Emission Tomograph (PET) scanner prototype with an innovative slow control and data acquisition features, for a demonstration purpose and within the crystal clear international collaboration. We also investigate a feasibility study of an online PET dedicated for inline and in situ dose deposition control in hadrontherapy. Here, we present the characterization setup and method we used to calibrate the detector heads of our PET prototype. Each of these heads consists of a single block continuous scintillating LySO crystal coupled to a multi-anode photomultiplier equipped with its proper acquisition readout chain.

  15. ARIES segmented gamma-ray scanner user manual

    Energy Technology Data Exchange (ETDEWEB)

    Biddle, R.S.; Sheppard, G.A.; Schneider, C.M.

    1998-04-16

    The segmented gamma-ray scatter (SGS) designated as Win{_}SGS at the Los Alamos Plutonium Facility has been installed and is intended for use in quantifying the radioisotope content of DOE-STD-3013-96 equivalent containers. The SGS features new software written in C and a new user interface that runs under Microsoft Windows{trademark}. The operation of the ARIES Segmented Gamma-ray Scanner is documented in this manual. It covers user instructions as well as hardware and software details. Additional information is found in the documentation for the commercially available components and modules that compose the SGS. The objective of the ARIES project is to demonstrate technology to dismantle plutonium pits from excess nuclear weapons, convert the plutonium to a metal ingot or an oxide powder, package the metal or oxide, and verify the contents of the package by nondestructive assay.

  16. Coincidence measurements on detectors for microPET II: A 1 mm3 resolution PET scanner for small animal imaging

    CERN Document Server

    Chatziioannou, A; Shao, Y; Doshi, N K; Silverman, B; Meadors, K; Cherry, SR

    2000-01-01

    We are currently developing a small animal PET scanner with a design goal of 1 mm3 image resolution. We have built three pairs of detectors and tested performance in terms of crystal identification, spatial, energy and timing resolution. The detectors consisted of 12 multiplied by 12 arrays of 1 multiplied by 1 multiplied by 10mm LSO crystals (1.15 mm pitch) coupled to Hamamatsu H7546 64 channel PMTs via 5cm long coherent glass fiber bundles. Optical fiber connection is necessary to allow high packing fraction in a ring geometry scanner. Fiber bundles with and without extramural absorber (EMA) were tested. The results demonstrated an intrinsic spatial resolution of 1.12 mm (direct coupled LSO array), 1.23 mm (bundle without EMA) and 1.27 mm (bundle with EMA) using a similar to 500 micron diameter Na-22 source. Using a 330 micron line source filled with F-18, intrinsic resolution for the EMA bundle improved to 1.05 mm. The respective timing and energy resolution values were 1.96 ns, 21% (direct coupled), 2.20 ...

  17. 21 CFR 862.2400 - Densitometer/scanner (integrating, reflectance, TLC, or radiochromatogram) for clinical use.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Densitometer/scanner (integrating, reflectance, TLC, or radiochromatogram) for clinical use. 862.2400 Section 862.2400 Food and Drugs FOOD AND DRUG..., reflectance, TLC, or radiochromatogram) for clinical use. (a) Identification. A densitometer/scanner...

  18. Digitisation of electron microscope films: Six useful tests applied to three film scanners

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, R. [MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH (United Kingdom)]. E-mail: rh15@mrc-lmb.cam.ac.uk; Cattermole, D. [MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH (United Kingdom); McMullan, G. [MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH (United Kingdom); Scotcher, S. [MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH (United Kingdom); Fordham, M. [MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH (United Kingdom); Amos, W.B. [MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH (United Kingdom); Faruqi, A.R. [MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH (United Kingdom)

    2007-02-15

    A series of simple tests have been used to measure the performance of flat-bed film scanners suitable for digitisation of electron micrographs. Two of the film scanners evaluated are commercially available and one has been constructed in the laboratory paying special attention to the needs of the electron microscopist. The tests may be useful for others.

  19. Development of a proton Computed Tomography (pCT) scanner at NIU

    CERN Document Server

    Uzunyan, S A; Boi, S; Coutrakon, G; Dyshkant, A; Erdelyi, B; Gearhart, A; Hedin, D; Johnson, E; Krider, J; Zutshi, V; Ford, R; Fitzpatrick, T; Sellberg, G; Rauch, J E; Roman, M; Rubinov, P; Wilson, P; Lalwani, K; Naimuddin, M

    2013-01-01

    We describe the development of a proton Computed Tomography (pCT) scanner at Northern Illinois University (NIU) in collaboration with Fermilab and Delhi University. This paper provides an overview of major components of the scanner and a detailed description of the data acquisition system (DAQ).

  20. Application of intra-oral dental scanners in the digital workflow of implantology

    NARCIS (Netherlands)

    van der Meer, Wicher J; Andriessen, Frank S; Wismeijer, Daniel; Ren, Yijin

    2012-01-01

    UNLABELLED: Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared. MATERIALS AND METHODS: A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned wit

  1. Application of intra-oral dental scanners in the digital workflow of implantology

    NARCIS (Netherlands)

    van der Meer, W.J.; Andriessen, F.S.; Wismeijer, D.; Ren, Y.

    2012-01-01

    Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared. Materials and methods: A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned with three intr

  2. Validity and Repeatability of the Sizestream 3D Scanner and Poikos Modeling System

    NARCIS (Netherlands)

    Vonk, T.E.; Daanen, H.A.M.

    2015-01-01

    Three-dimensional (3D) body scanning becomes increasingly important in the medical, ergonomical and apparel industry. The SizeStream 3D body scanner is a 3D body scanner in the shape of a fitting room that can generate a 3D copy of the human body in a few seconds. The Poikos modeling system

  3. Calibration between a Laser Range Scanner and an Industrial Robot Manipulator

    DEFF Research Database (Denmark)

    Andersen, Thomas Timm; Andersen, Nils Axel; Ravn, Ole

    2014-01-01

    In this paper we present a method for findingthe transformation between a laser scanner and a robotmanipulator. We present the design of a flat calibration targetthat can easily fit between a laser scanner and a conveyor belt,making the method easily implementable in a manufacturingline.We prove...

  4. Application of intra-oral dental scanners in the digital workflow of implantology

    NARCIS (Netherlands)

    van der Meer, W.J.; Andriessen, F.S.; Wismeijer, D.; Ren, Y.

    2012-01-01

    Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared. Materials and methods: A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned with three intr

  5. The estimation of pre- and postpromotion dips with store-level scanner data

    NARCIS (Netherlands)

    Heerde, Harald J. van; Leeflang, Peter S.H.; Wittink, Dick R.

    1999-01-01

    One of the mysteries of store-level scanner data modeling is the lack of a dip in sales in the week(s) following a promotion. Researchers expect to find a postpromotion dip because analyses of household scanner panel data indicate that consumers tend to accelerate their purchases in response to a pr

  6. The estimation of pre- and postpromotion dips with store-level scanner data

    NARCIS (Netherlands)

    Van Heerde, HJ; Leeflang, PSH; Wittink, DR

    2000-01-01

    One of the mysteries of store-level scanner data modeling is the lack of a dip in sales in the weeks following a promotion. Researchers expect to find a postpromotion dip because analyses of household scanner panel data indicate that consumers tend to accelerate their purchases in response to a prom

  7. Validity and Repeatability of the Sizestream 3D Scanner and Poikos Modeling System

    NARCIS (Netherlands)

    Vonk, T.E.; Daanen, H.A.M.

    2015-01-01

    Three-dimensional (3D) body scanning becomes increasingly important in the medical, ergonomical and apparel industry. The SizeStream 3D body scanner is a 3D body scanner in the shape of a fitting room that can generate a 3D copy of the human body in a few seconds. The Poikos modeling system generate

  8. Performance of the Transverse Oscillation method using beamformed data from a commercial scanner

    DEFF Research Database (Denmark)

    Pihl, Michael Johannes; Nikolov, S.; Haugaard, P.

    2009-01-01

    of this is evaluated on a commercial platform. Beamformed data are acquired using a commercial BK Medical scanner as opposed to the previously reported results obtained with the experimental scanner RASMUS. The implementation is evaluated using an in-house circulating flow rig by calculating the relative mean standard...

  9. Oscillatory disturbance in force calibration of optical tweezers

    Institute of Scientific and Technical Information of China (English)

    Liu Chun-Xiang; Guo Hong-Lian; Jiang Yu-Qiang; Li Zhao-Lin; Cheng Bing-Ying; Zhang Dao-Zhong

    2005-01-01

    In the calibration of the optical trap stiffness, it is found that there appears an attenuating oscillation as an oscillatory disturbance added to the trapped bead movement, when the scanner is driven by a triangular wave input.An equivalent oscillator model is put forward to explain the mechanism of the oscillatory disturbance. Both the measurements and calculations show that the attenuating oscillation comes from the oscillation of the scanner and the triangular wave drive causes this additional oscillation of the scanner. Furthermore, the analysis indicates that the oscillatory disturbance will become stronger, when the stiffness of the trap increases or the natural frequency of the scanner decreases. We adopt another driving way, i.e. a sinusoidal wave input is used instead of the triangular wave input. Our experiment has verified that in this case the oscillatory disturbance is eliminated completely.

  10. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    Energy Technology Data Exchange (ETDEWEB)

    Liao, S; Wang, Y; Weng, H [Chiayi Chang Gung Memorial Hospital of The C.G.M.F, Puzi City, Chiayi County, Taiwan (China)

    2015-06-15

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle.

  11. 2D MEMS electrostatic cantilever waveguide scanner for potential image display application

    Directory of Open Access Journals (Sweden)

    Gu Kebin

    2015-01-01

    Full Text Available This paper presents the current status of our micro-fabricated SU-8 2D electrostatic cantilever waveguide scanner. The current design utilizes a monolithically integrated electrostatic push-pull actuator. A 4.0 μm SU-8 rib waveguide design allows a relatively large core cross section (4μm in height and 20 μm in width to couple with existing optical fiber and a broad band single mode operation (λ= 0.7μm to 1.3μm with minimal transmission loss (85% to 87% output transmission efficiency with Gaussian beam profile input. A 2D scanning motion has been successfully demonstrated with two fundamental resonances found at 202 and 536 Hz in vertical and horizontal directions. A 130 μm and 19 μm, corresponding displacement and 0.062 and 0.009 rad field of view were observed at a +150V input. Beam divergence from the waveguide was corrected by a focusing GRIN lens and a 5μm beam diameter is observed at the focal plane. The transmission efficiency is low (~10% and cantilever is slightly under tensile residual stress due to inherent imperfection in the process and tooling in fabrication. However, 2D light scanning pattern was successfully demonstrated using 1-D push-pull actuation.

  12. Experimental results of the laserwire emittance scanner for LINAC4 at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Thomas, E-mail: thomas.hofmann@cern.ch [CERN, Geneva 1211 (Switzerland); John Adams Institute at Royal Holloway, University of London, Egham TW20 0EX (United Kingdom); Friedrich-Alexander-University, Erlangen 91054 (Germany); Boorman, Gary E.; Bosco, Alessio [John Adams Institute at Royal Holloway, University of London, Egham TW20 0EX (United Kingdom); Bravin, Enrico [CERN, Geneva 1211 (Switzerland); Gibson, Stephen M.; Kruchinin, Konstantin O. [John Adams Institute at Royal Holloway, University of London, Egham TW20 0EX (United Kingdom); Raich, Uli; Roncarolo, Federico; Zocca, Francesca [CERN, Geneva 1211 (Switzerland)

    2016-09-11

    Within the framework of the LHC Injector Upgrade (LIU), the new LINAC4 is currently being commissioned to replace the existing LINAC2 proton source at CERN. After the expected completion at the end of 2016, the LINAC4 will accelerate H{sup −} ions to 160 MeV. To measure the transverse emittance of the H{sup −} beam, a method based on photo-detachment is proposed. This system will operate using a pulsed laser with light delivered via an optical fibre and subsequently focused onto the H{sup −} beam. The laser photons have sufficient energy to detach the outer electron and create H{sup 0}/e{sup −} pairs. In a downstream dipole, the created H{sup 0} particles are separated from the unstripped H{sup −} ions and their distribution is measured with a dedicated detector. By scanning the focused laser beam across the H{sup −} beam, the transverse emittance of the H{sup −} beam can be reconstructed. This paper will first discuss the concept, design and simulations of the laser emittance scanner and then present results from a prototype system used during the 12 MeV commissioning of the LINAC4.

  13. Experimental investigations of the scanning functions of galvanometer-based scanners with applications in OCT.

    Science.gov (United States)

    Duma, Virgil-Florin; Lee, Kye-sung; Meemon, Panomsak; Rolland, Jannick P

    2011-10-10

    We analyze the three most common profiles of scanning functions for galvanometer-based scanners (GSs): the sawtooth, triangular and sinusoidal functions. They are determined experimentally with regard to the scan parameters of the input signal (i.e., frequency and amplitude). We study the differences of the output function of the GS measured as the positional error of the oscillatory mirror from the ideal function given by the input signal of the device. The limits in achieving the different types of scanning functions in terms of duty cycle and linearity are determined experimentally for the possible range of scan parameters. Of particular importance are the preservation of an imposed duty cycle and profile for the sawtooth function, the quantification of the linearity for the sinusoidal function, and the effective duty cycle for the triangular, as well as for the other functions. The range of scan amplitudes for which the stability of the oscillatory regime of the galvo mirror is stable for different frequencies is also highlighted. While the use of the device in certain scanning regimes is studied, certain rules of thumb are deduced to make the best out of the galvoscanner. Finally, the three types of scanning functions are tested with a Fourier domain optical coherence tomography (FD OCT) setup and the conclusions of the study are demonstrated in an imaging application by correlating the determined limits of the scanning regimes with the requirements of OCT.

  14. Sampling FEE and Trigger-less DAQ for the J-PET Scanner

    CERN Document Server

    Korcyl, G; Bednarski, T; Białas, P; Czerwiński, E; Dulski, K; Gajos, A; Głowacz, B; Jasińska, B; Kamińska, D; Kapłon, Ł; Kowalski, P; Kozik, T; Krzemień, W; Kubicz, E; Mohammed, M; Niedźwiecki, Sz; Pałka, M; Pawlik-Niedźwiecka, M; Raczyński, L; Rudy, Z; Rundel, O; Sharma, N G; Silarski, M; Słomski, A; Stoła, K; Strzelecki, A; Wieczorek, A; Wiślicki, W; Zgardzińska, B K; Zieliński, M; Moskal, P

    2016-01-01

    In this paper, we present a complete Data Acquisition System (DAQ) together with the readout mechanisms for the J-PET tomography scanner. In general detector readout chain is constructed out of Front-End Electronics (FEE), measurement devices like Time-to-Digital or Analog-to-Digital Converters (TDCs or ADCs), data collectors and storage. We have developed a system capable for maintaining continuous readout of digitized data without preliminary selection. Such operation mode results in up to 8 Gbps data stream, therefore it is required to introduce a dedicated module for online event building and feature extraction. The Central Controller Module, equipped with Xilinx Zynq SoC and 16 optical transceivers serves as such true real time computing facility. Our solution for the continuous data recording (trigger-less) is a novel approach in such detector systems and assures that most of the information is preserved on the storage for further, high-level processing. Signal discrimination applies an unique method of...

  15. Experimental results of the laserwire emittance scanner for LINAC4 at CERN

    Science.gov (United States)

    Hofmann, Thomas; Boorman, Gary E.; Bosco, Alessio; Bravin, Enrico; Gibson, Stephen M.; Kruchinin, Konstantin O.; Raich, Uli; Roncarolo, Federico; Zocca, Francesca

    2016-09-01

    Within the framework of the LHC Injector Upgrade (LIU), the new LINAC4 is currently being commissioned to replace the existing LINAC2 proton source at CERN. After the expected completion at the end of 2016, the LINAC4 will accelerate H- ions to 160 MeV. To measure the transverse emittance of the H- beam, a method based on photo-detachment is proposed. This system will operate using a pulsed laser with light delivered via an optical fibre and subsequently focused onto the H- beam. The laser photons have sufficient energy to detach the outer electron and create H0/e- pairs. In a downstream dipole, the created H0 particles are separated from the unstripped H- ions and their distribution is measured with a dedicated detector. By scanning the focused laser beam across the H- beam, the transverse emittance of the H- beam can be reconstructed. This paper will first discuss the concept, design and simulations of the laser emittance scanner and then present results from a prototype system used during the 12 MeV commissioning of the LINAC4.

  16. Surface curvature of pelvic joints from three laser scanners: separating anatomy from measurement error.

    Science.gov (United States)

    Villa, Chiara; Gaudio, Daniel; Cattaneo, Cristina; Buckberry, Jo; Wilson, Andrew S; Lynnerup, Niels

    2015-03-01

    Recent studies have reported that quantifying symphyseal and auricular surface curvature changes on 3D models acquired by laser scanners has a potential for age estimation. However, no tests have been carried out to evaluate the repeatability of the results between different laser scanners. 3D models of the two pelvic joints were generated using three laser scanners (Custom, Faro, and Minolta). The surface curvature, the surface area, and the distance between co-registered meshes were investigated. Close results were found for surface areas (differences between 0.3% and 2.4%) and for distance deviations (average laser scanners, but still showing similar trends with increasing phases/scores. Applying a smoothing factor to the 3D models, it was possible to separate anatomy from the measurement error of each instrument, so that similar curvature values could be obtained (p laser scanner.

  17. Design considerations for a limited angle, dedicated breast, TOF PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Surti, S; Karp, J S [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States)], E-mail: surti@mail.med.upenn.edu, E-mail: joelkarp@mail.med.upenn.edu

    2008-06-07

    Development of partial ring, dedicated breast positron emission tomography (PET) scanners is an active area of research. Due to the limited angular coverage, generation of distortion and artifact-free, fully 3D tomographic images is not possible without rotation of the detectors. With time-of-flight (TOF) information, it is possible to achieve the 3D tomographic images with limited angular coverage and without detector rotation. We performed simulations for a breast scanner design with a ring diameter and an axial length of 15 cm and comprising a full (180{sup 0} in-plane angular coverage), 2/3 (120{sup 0} in-plane angular coverage) or 1/2 (90{sup 0} in-plane angular coverage) ring detector. Our results show that as the angular coverage decreases, improved timing resolution is needed to achieve distortion-free and artifact-free images with TOF. The contrast recovery coefficient (CRC) value for small hot lesions in a partial ring scanner is similar to a full ring non-TOF scanner. Our results indicate that a timing resolution of 600 ps is needed for a 2/3 ring scanner, while a timing resolution of 300 ps is needed for a 1/2 ring scanner. We also analyzed the ratio of lesion CRC to the background pixel noise (SNR) and concluded that TOF improves the SNR values of the partial ring scanner, and helps to compensate for the loss in sensitivity due to reduced geometric sensitivity in a limited angle coverage PET scanner. In particular, it is possible to maintain similar SNR characteristic in a 2/3 ring scanner with a timing resolution of 300 ps as in a full ring non-TOF scanner.

  18. Design considerations for a limited angle, dedicated breast, TOF PET scanner

    Science.gov (United States)

    Surti, S.; Karp, J. S.

    2008-06-01

    Development of partial ring, dedicated breast positron emission tomography (PET) scanners is an active area of research. Due to the limited angular coverage, generation of distortion and artifact-free, fully 3D tomographic images is not possible without rotation of the detectors. With time-of-flight (TOF) information, it is possible to achieve the 3D tomographic images with limited angular coverage and without detector rotation. We performed simulations for a breast scanner design with a ring diameter and an axial length of 15 cm and comprising a full (180° in-plane angular coverage), 2/3 (120° in-plane angular coverage) or 1/2 (90° in-plane angular coverage) ring detector. Our results show that as the angular coverage decreases, improved timing resolution is needed to achieve distortion-free and artifact-free images with TOF. The contrast recovery coefficient (CRC) value for small hot lesions in a partial ring scanner is similar to a full ring non-TOF scanner. Our results indicate that a timing resolution of 600 ps is needed for a 2/3 ring scanner, while a timing resolution of 300 ps is needed for a 1/2 ring scanner. We also analyzed the ratio of lesion CRC to the background pixel noise (SNR) and concluded that TOF improves the SNR values of the partial ring scanner, and helps to compensate for the loss in sensitivity due to reduced geometric sensitivity in a limited angle coverage PET scanner. In particular, it is possible to maintain similar SNR characteristic in a 2/3 ring scanner with a timing resolution of 300 ps as in a full ring non-TOF scanner.

  19. A Structured Light Scanner for Hyper Flexible Industrial Automation

    DEFF Research Database (Denmark)

    Hansen, Kent; Pedersen, Jeppe; Sølund, Thomas

    2014-01-01

    A current trend in industrial automation implies a need for doing automatic scene understanding, from optical 3D sensors, which in turn imposes a need for a lightweight and reliable 3D optical sensor to be mounted on a collaborative robot e.g., Universal Robot UR5 or Kuka LWR. Here, we empirically...

  20. Airborne Radiative Transfer Spectral Scanner: A new airborne hyperspectral imager for hyperspectral volcano observations

    Science.gov (United States)

    Jitsufuchi, T.

    2007-12-01

    In 2006, a new airborne hyperspectral imager, the Airborne Radiative Transfer Spectral Scanner (ARTS), was developed for hyperspectral volcano observations. ARTS provides hyperspectral images to support developing algorithms for the remote sensing of the geothermal distribution, the ash fall areas, and the volcanic gasses columnar content from the air. ARTS will be used mainly to assess volcanic activity and to mitigate volcanic disasters. ARTS is a pushbroom imaging spectrometer covering wavelengths from 380 to 2450nm and 8000 to 11500nm with 421 bands. The ARTS imaging spectrometer consists of three sensor head units (SHUs). These SHUs are the visible - near infrared (VNIR) SHU, the shortwave infrared (SWIR) SHU, and the long-wave infrared (LWIR) SHU. These sensor head units operate as a line scanner in the pushbroom mode from an aircraft. The VNIR SHU covers wavelengths from 380 to 1050nm with 288 spectrum bands. The field of view (FOV) is 40 degrees, and the image of this SHU is 1500 pixels wide cross-track, making the instantaneous field of view (IFOV) 0.49mrad. The SWIR SHU covers wavelengths from 900 to 2450nm with 101 spectrum bands. The LWIR SHU covers wavelengths from 8000 to 11500nm with 32 spectrum bands. SWIR SHU and LWIR SHU have FOVs of 40 degrees and 600-pixel-wide images cross-track, giving them an IFOV of 1.2mrad. ARTS has precise position and attitude measurement systems (GPS/IMU). Direct, accurate geo-corrections of each SHU image can be made using the GPS/IMU systems. ARTS will be used for the operational volcano observation beginning in 2008. We are now validating the in-flight performance of this sensor. In this study, we describe the ARTS optical, electrical, and mechanical systems; its data acquisition and system design; and present some preliminary in- flight performance test results obtained from measurements acquired aboard the Beechcraft King Air B200 aircraft. The validation results indicate that the geo-correction accuracy is

  1. Integrated monolithic 3D MEMS scanner for switchable real time vertical/horizontal cross-sectional imaging.

    Science.gov (United States)

    Li, Haijun; Duan, Xiyu; Qiu, Zhen; Zhou, Quan; Kurabayashi, Katsuo; Oldham, Kenn R; Wang, Thomas D

    2016-02-08

    We present an integrated monolithic, electrostatic 3D MEMS scanner with a compact chip size of 3.2 × 2.9 mm(2). Use of parametric excitation near resonance frequencies produced large optical deflection angles up to ± 27° and ± 28.5° in the X- and Y-axes and displacements up to 510 μm in the Z-axis with low drive voltages at atmospheric pressure. When packaged in a dual axes confocal endomicroscope, horizontal and vertical cross-sectional images can be collected seamlessly in tissue with a large field-of-view of >1 × 1 mm(2) and 1 × 0.41 mm(2), respectively, at 5 frames/sec.

  2. A low-cost and versatile system for projecting wide-field visual stimuli within fMRI scanners.

    Science.gov (United States)

    Greco, V; Frijia, F; Mikellidou, K; Montanaro, D; Farini, A; D'Uva, M; Poggi, P; Pucci, M; Sordini, A; Morrone, M C; Burr, D C

    2016-06-01

    We have constructed and tested a custom-made magnetic-imaging-compatible visual projection system designed to project on a very wide visual field (~80°). A standard projector was modified with a coupling lens, projecting images into the termination of an image fiber. The other termination of the fiber was placed in the 3-T scanner room with a projection lens, which projected the images relayed by the fiber onto a screen over the head coil, viewed by a participant wearing magnifying goggles. To validate the system, wide-field stimuli were presented in order to identify retinotopic visual areas. The results showed that this low-cost and versatile optical system may be a valuable tool to map visual areas in the brain that process peripheral receptive fields.

  3. MRI-derived measurements of human subcortical, ventricular and intracranial brain volumes: Reliability effects of scan sessions, acquisition sequences, data analyses, scanner upgrade, scanner vendors and field strengths.

    Science.gov (United States)

    Jovicich, Jorge; Czanner, Silvester; Han, Xiao; Salat, David; van der Kouwe, Andre; Quinn, Brian; Pacheco, Jenni; Albert, Marilyn; Killiany, Ronald; Blacker, Deborah; Maguire, Paul; Rosas, Diana; Makris, Nikos; Gollub, Randy; Dale, Anders; Dickerson, Bradford C; Fischl, Bruce

    2009-05-15

    Automated MRI-derived measurements of in-vivo human brain volumes provide novel insights into normal and abnormal neuroanatomy, but little is known about measurement reliability. Here we assess the impact of image acquisition variables (scan session, MRI sequence, scanner upgrade, vendor and field strengths), FreeSurfer segmentation pre-processing variables (image averaging, B1 field inhomogeneity correction) and segmentation analysis variables (probabilistic atlas) on resultant image segmentation volumes from older (n=15, mean age 69.5) and younger (both n=5, mean ages 34 and 36.5) healthy subjects. The variability between hippocampal, thalamic, caudate, putamen, lateral ventricular and total intracranial volume measures across sessions on the same scanner on different days is less than 4.3% for the older group and less than 2.3% for the younger group. Within-scanner measurements are remarkably reliable across scan sessions, being minimally affected by averaging of multiple acquisitions, B1 correction, acquisition sequence (MPRAGE vs. multi-echo-FLASH), major scanner upgrades (Sonata-Avanto, Trio-TrioTIM), and segmentation atlas (MPRAGE or multi-echo-FLASH). Volume measurements across platforms (Siemens Sonata vs. GE Signa) and field strengths (1.5 T vs. 3 T) result in a volume difference bias but with a comparable variance as that measured within-scanner, implying that multi-site studies may not necessarily require a much larger sample to detect a specific effect. These results suggest that volumes derived from automated segmentation of T1-weighted structural images are reliable measures within the same scanner platform, even after upgrades; however, combining data across platform and across field-strength introduces a bias that should be considered in the design of multi-site studies, such as clinical drug trials. The results derived from the young groups (scanner upgrade effects and B1 inhomogeneity correction effects) should be considered as preliminary and in

  4. Micromachined microscanners for optical scanning

    Science.gov (United States)

    Kiang, Meng-Hsiung; Solgaard, Olav; Muller, Richard S.; Lau, Kam Y.

    1997-04-01

    We present the design and fabrication of surface- micromachined electrostatic-comb driven microscanners that have high angular precision over a large scan angle. When used as resonant scanners, these mirrors have fast scan rates with very low operating power. We use polysilicon microhinges, which allow the micromirrors to be lifted out of the plane of the substrate after processing is completed, to create high-aspect-ratio optical surfaces with dimensions in the hundreds of micrometers s while taking advantage of the planar surface-micromachining processing technology. Microscanners that are capable of high-speed scanning over large scan angles with high precision have been fabricated. Application of these actuated micromirrors in laser barcode scanning and optical-fiber switches have been demonstrated. These single-mirror scanners can be combined to form more complicated microscanners such as a two-mirror, two-axis raster scanner that have a wide range of applications in areas such as medicine, displays, printing, data storage, and communications.

  5. MR thermometry analysis program for laser- or high-intensity focused ultrasound (HIFU)-induced heating at a clinical MR scanner

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Ju; Jeong, Ki Young; Oh, Seung Jae; Park, Eun Hae; Lee, Young Han; Suh, Jin Suck [Yonsei University College of Medicine, Seoul (Korea, Republic of); Kim, Dae Hong [National Cancer Center, Goyang (Korea, Republic of)

    2014-12-15

    Magnetic resonance (MR) thermometry is a noninvasive method for monitoring local temperature change during thermal therapy. In this study, a MR temperature analysis program was established for a laser with gold nanorods (GNRs) and high-intensity focused ultrasound (HIFU)-induced heating MR thermometry. The MR temperature map was reconstructed using the water proton resonance frequency (PRF) method. The temperature-sensitive phase difference was acquired by using complex number subtraction instead of direct phase subtraction in order to avoid another phase unwrapping process. A temperature map-analyzing program was developed and implemented in IDL (Interactive Data Language) for effective temperature monitoring. This one program was applied to two different heating devices at a clinical MR scanner. All images were acquired with the fast spoiled gradient echo (fSPGR) pulse sequence on a 3.0 T GE Discovery MR750 scanner with an 8-channel knee array coil or with a home-built small surface coil. The analyzed temperature values were confirmed by using values simultaneously measured with an optical temperature probe (R{sup 2} = 0.996). The temperature change in small samples induced by a laser or by HIFU was analyzed by using a raw data, that consisted of complex numbers. This study shows that our MR thermometry analysis program can be used for thermal therapy study with a laser or HIFU at a clinical MR scanner. It can also be applied to temperature monitoring for any other thermal therapy based on the PRF method.

  6. Comparison of working efficiency of terrestrial laser scanner in day and night conditions

    Science.gov (United States)

    Arslan, A. E.; Kalkan, K.

    2013-10-01

    Terrestrial Laser Scanning is a popular and widely used technique to scan existing objects, document historical sites and items, and remodel them if and when needed. Their ability to collect thousands of point data per second makes them an invaluable tool in many areas from engineering to historical reconstruction. There are many scanners in the market with different technical specifications. One main technical specification of laser scanners is range and illumination. In this study, it is tested to be determined the optimal working times of a laser scanner and the scanners consistency with its specifications sheet. In order to conduct this work, series of GNSS measurements in Istanbul Technical University have been carried out, connected to the national reference network, to determine precise positions of target points and the scanner, which makes possible to define a precise distance between the scanner and targets. Those ground surveys has been used for calibration and registration purposes. Two different scan campaigns conducted at 12 am and 11 pm to compare working efficiency of laser scanner in different illumination conditions and targets are measured with a handheld spectro-radiometer in order to determine their reflective characteristics. The obtained results are compared and their accuracies have been analysed.

  7. Accuracy evaluation of a lower-cost and four higher-cost laser scanners.

    Science.gov (United States)

    Campanelli, Valentina; Howell, Stephen M; Hull, Maury L

    2016-01-04

    Knowing the accuracy of laser scanners is imperative to select the best scanner to generate bone models. However, errors stated by manufacturers may not apply to bones. The three objectives of this study were to determine: 1) whether the overall error stated by the manufacturers of five laser scanners was different from the root mean squared error (RMSE) computed by scanning a gage block; 2) the repeatability of 3D models generated by the laser scanners when scanning a complex freeform surface such as a distal femur and whether this differed from the repeatability when scanning a gage block; 3) whether the errors for one lower-cost laser scanner are comparable to those of four higher-cost laser scanners. The RMSEs in scanning the gage block were 2 to 52µm lower than the overall errors stated by the manufacturers. The repeatability in scanning the bovine femur 10 times was significantly worse than that in scanning the gage block 10 times. The precision of the lower-cost laser scanner was comparable to that of the higher-cost laser scanners, but the bias was an order of magnitude greater. The contributions of this study are that 1) the overall errors stated by the manufacturers are an upper bound when simple geometric objects like a gage block are scanned, 2) the repeatability is worse on average three times when scanning a complex freeform surface compared to scanning the gage block, and 3) the main difference between the lower-cost and the higher-cost laser scanners is the bias.

  8. Revised benchmarking of contact-less fingerprint scanners for forensic fingerprint detection: challenges and results for chromatic white light scanners (CWL)

    Science.gov (United States)

    Kiltz, Stefan; Leich, Marcus; Dittmann, Jana; Vielhauer, Claus; Ulrich, Michael

    2011-02-01

    Mobile contact-less fingerprint scanners can be very important tools for the forensic investigation of crime scenes. To be admissible in court, data and the collection process must adhere to rules w.r.t. technology and procedures of acquisition, processing and the conclusions drawn from that evidence. Currently, no overall accepted benchmarking methodology is used to support some of the rules regarding the localisation, acquisition and pre-processing using contact-less fingerprint scanners. Benchmarking is seen essential to rate those devices according to their usefulness for investigating crime scenes. Our main contribution is a revised version of our extensible framework for methodological benchmarking of contact-less fingerprint scanners using a collection of extensible categories and items. The suggested main categories describing a contact-less fingerprint scanner are properties of forensic country-specific legal requirements, technical properties, application-related aspects, input sensory technology, pre-processing algorithm, tested object and materials. Using those it is possible to benchmark fingerprint scanners and describe the setup and the resulting data. Additionally, benchmarking profiles for different usage scenarios are defined. First results for all suggested benchmarking properties, which will be presented in detail in the final paper, were gained using an industrial device (FRT MicroProf200) and conducting 18 tests on 10 different materials.

  9. Development of a Confocal Optical System Design for Molecular Imaging Applications of Biochip

    Directory of Open Access Journals (Sweden)

    Guoliang Huang

    2007-01-01

    Full Text Available A novel confocal optical system design and a dual laser confocal scanner have been developed to meet the requirements of highly sensitive detection of biomolecules on microarray chips, which is characterized by a long working distance (wd>3.0 mm, high numerical aperture (NA=0.72, and only 3 materials and 7 lenses used. This confocal optical system has a high scanning resolution, an excellent contrast and signal-to-noise ratio, and an efficiency of collected fluorescence of more than 2-fold better than that of other commercial confocal biochip scanners. The scanner is as equally good for the molecular imaging detection of enclosed biochips as for the detection of biological samples on a slide surface covered with a cover-slip glass. Some applications of gene and protein imagings using the dual laser confocal scanner are described.

  10. The Experiment and Design of Confocal Laser Scanner for Biochip

    Institute of Scientific and Technical Information of China (English)

    Guangzhao Zhang; Huijie Huang; Hao Ruan; Dan Chen; Bingqiang Ren

    2003-01-01

    In this article ,we chiefly discuss optical part and photoelectrical part, and analyze the result data to make out the relationship between pinhole and special resolution and the influence of PMT on the result data.

  11. Novel Hemispherical Scanner for a Coherent Fiber LIDAR System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SibellOptics proposes to develop an eye-safe, long-range, compact, versatile, all-fiber wind LIDAR system for atmospheric wind velocity measurement applications that...

  12. Mechanical optimisation of a high-precision fast wire scanner at CERN

    CERN Document Server

    Samuelsson, Sebastian; Veness, Raymond

    Wire scanners are instruments used to measure the transverse beam prole in particle accelerators by passing a thin wire through the particle beam. To avoid the issues of vacuum leakage through the bellows and wire failure related to current designs of wire scanners, a new concept for a wire scanner has been developed at CERN. This design has all moving parts inside the beam vacuum and has a nominal wire scanning speed of 20 m/s. The demands on the design associated with this together with the high precision requirements create a need for\

  13. 3D handheld laser scanner based approach for automatic identification and localization of EEG sensors.

    Science.gov (United States)

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

    2010-01-01

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

  14. High Resolution Aircraft Scanner Mapping of Geothermal and Volcanic Areas

    Energy Technology Data Exchange (ETDEWEB)

    Mongillo, M.A.; Cochrane, G.R.; Wood, C.P.; Shibata, Y.

    1995-01-01

    High spectral resolution GEOSCAN Mkll multispectral aircraft scanner imagery has been acquired, at 3-6 m spatial resolutions, over much of the Taupo Volcanic Zone as part of continuing investigations aimed at developing remote sensing techniques for exploring and mapping geothermal and volcanic areas. This study examined the 24-band: visible, near-IR (NIR), mid-IR (MIR) and thermal-IR (TIR) imagery acquired over Waiotapu geothermal area (3 m spatial resolution) and White Island volcano (6 m resolution). Results show that color composite images composed of visible and NIR wavelengths that correspond to color infrared (CIR) photographic wavelengths can be useful for distinguishing among bare ground, water and vegetation features and, in certain cases, for mapping various vegetation types. However, combinations which include an MIR band ({approx} 2.2 {micro}m) with either visible and NIR bands, or two NIR bands, are the most powerful for mapping vegetation types, water bodies, and bare and hydrothermally altered ground. Combinations incorporating a daytime TIR band with NIR and MIR bands are also valuable for locating anomalously hot features and distinguishing among different types of surface hydrothermal alteration.

  15. Vacuum Actuator and Controller Design for a Fast Wire Scanner

    CERN Document Server

    Dehning, B; Herranz Alvarez, J; Koujili, M; Sirvent Blasco, J L

    2012-01-01

    To cope with increasing requirements in terms of accuracy and beam intensity limits a beam wire scanner (BWS) design is under development for the CERN accelerators complex. The main parameters have been determined; the wire speed should be 20 m·s -1 when interacting with the beam and a beam width determination accuracy of 2µm under the harsh radioactive environment should be reached. To meet this goal, the proposed solution locates all moveable parts of the actuator and the angular sensors in the beam vacuum pipe in order to reduce the friction and to allow a direct position measurement. One absolute positioning sensor will be used for the brushless motor feedback and one custom, high precision incremental design will target the beam size determination. The laboratory tests set up for the actuator and the incremental sensor will be presented along with the motor control feedback loops developed with the DSpace environment using Simulink and MatLab tools. Finally, the development of the digital...

  16. Fast Automatic Precision Tree Models from Terrestrial Laser Scanner Data

    Directory of Open Access Journals (Sweden)

    Mathias Disney

    2013-01-01

    Full Text Available This paper presents a new method for constructing quickly and automatically precision tree models from point clouds of the trunk and branches obtained by terrestrial laser scanning. The input of the method is a point cloud of a single tree scanned from multiple positions. The surface of the visible parts of the tree is robustly reconstructed by making a flexible cylinder model of the tree. The thorough quantitative model records also the topological branching structure. In this paper, every major step of the whole model reconstruction process, from the input to the finished model, is presented in detail. The model is constructed by a local approach in which the point cloud is covered with small sets corresponding to connected surface patches in the tree surface. The neighbor-relations and geometrical properties of these cover sets are used to reconstruct the details of the tree and, step by step, the whole tree. The point cloud and the sets are segmented into branches, after which the branches are modeled as collections of cylinders. From the model, the branching structure and size properties, such as volume and branch size distributions, for the whole tree or some of its parts, can be approximated. The approach is validated using both measured and modeled terrestrial laser scanner data from real trees and detailed 3D models. The results show that the method allows an easy extraction of various tree attributes from terrestrial or mobile laser scanning point clouds.

  17. Evaluation of a laser scanner for surface topography.

    Science.gov (United States)

    Hill, D L; Berg, D C; Raso, V J; Lou, E; Durdle, N G; Mahood, J K; Moreau, M J

    2002-01-01

    A Minolta VIVID 700 portable non-contact 3D laser scanner was evaluated on 15 subjects with idiopathic scoliosis. The 3D map was compared to two structured light pattern (lines and dots) techniques to determine the reliability, ease of use, speed, and quality. The parameters used for the clinical assessment of scoliosis were measured twice for the Minolta and light projection systems. The edges of the image and areas where occlusion typically occur were examined. The absolute distance in calculated depth between adjacent points was examined to determine errors. The Minolta system and the dot pattern produced regular grids of points. The light projection pattern produced an irregular grid, with more resolution along the video line and less resolution between projected lines, resulted in a somewhat jagged appearance of the surface map. The Minolta system was less sensitive to edge effects, occlusion, and sharp transitions of depth. The comparison of clinical parameters showed good results between repetitions but moderate results between techniques.

  18. 2D MEMS scanner integrating a position feedback

    Directory of Open Access Journals (Sweden)

    Lani Sebastien

    2015-01-01

    Full Text Available An integrated position sensor for a dual-axis electromagnetic tilting mirror is presented. This tilting mirror is composed of a silicon based mirror directly assembled on a silicon membrane supported by flexible beams. The position sensors are constituted by 4 Wheatstone bridges of piezoresistors which are fabricated by doping locally the flexible beams. A permanent magnet is attached to the membrane and the scanner is mounted above planar coils deposited on a ceramic substrate to achieve electromagnetic actuation. The performances of the piezoresistive sensors are evaluated by measuring the output signal of the piezoresistors as a function of the tilt of the mirror and the temperature. White light interferometry was performed for all measurement to measure the exact tilt angle. The minimum detectable angle with such sensors was 30μrad (around 13bits in the range of the minimum resolution of the interferometer. The tilt reproducibility was 0.0186%, obtained by measuring the tilt after repeated actuations with a coil current of 50mA during 30 min and the stability over time was 0.05% in 1h without actuation. The maximum measured tilt angle was 6° (mechanical limited by nonlinearity of the MEMS system.

  19. a Light-Weight Laser Scanner for Uav Applications

    Science.gov (United States)

    Tommaselli, A. M. G.; Torres, F. M.

    2016-06-01

    Unmanned Aerial Vehicles (UAV) have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP) as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

  20. A LIGHT-WEIGHT LASER SCANNER FOR UAV APPLICATIONS

    Directory of Open Access Journals (Sweden)

    A. M. G. Tommaselli

    2016-06-01

    Full Text Available Unmanned Aerial Vehicles (UAV have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

  1. Modified robust sliding-mode control method for wafer scanner

    Directory of Open Access Journals (Sweden)

    Yiguang Wang

    2015-03-01

    Full Text Available This article studies the precision motion control of a long-stroke reticle stage driven by the permanent magnet linear motor in wafer scanner. A robust sliding-mode control method is proposed for tracking the reference trajectory in the presence of un-modeled dynamics, parametric uncertainty and external disturbances including force ripple, cogging and friction in the controlled system. A modified sliding-mode term based on the variable structure technique for eliminating the tracking error is employed in the proposed control law. The system stability and tracking convergence of the closed-loop control system are guaranteed by Lyapunov theory theoretically. The feasibility and effectiveness of the proposed method are demonstrated by comparative experiments on a linear motion testbed. The experimental results show that better tracking performance can be achieved by the proposed method compared with the conventional proportional–integral–derivative method and it can be considered as a possible alternative in the precision motion control system.

  2. Physical performance evaluation of a 256-slice CT-scanner for four-dimensional imaging.

    Science.gov (United States)

    Mori, Shinichiro; Endo, Masahiro; Tsunoo, Takanori; Kandatsu, Susumu; Tanada, Shuji; Aradate, Hiroshi; Saito, Yasuo; Miyazaki, Hiroaki; Satoh, Kazumasa; Matsushita, Satoshi; Kusakabe, Masahiro

    2004-06-01

    We have developed a prototype 256-slice CT-scanner for four-dimensional (4D) imaging that employs continuous rotations of a cone-beam. Since a cone-beam scan along a circular orbit does not collect a complete set of data to make an exact reconstruction of a volume [three-dimensional (3D) image], it might cause disadvantages or artifacts. To examine effects of the cone-beam data collection on image quality, we have evaluated physical performance of the prototype 256-slice CT-scanner with 0.5 mm slices and compared it to that of a 16-slice CT-scanner with 0.75 mm slices. As a result, we found that image noise, uniformity, and high contrast detectability were independent of z coordinate. A Feldkamp artifact was observed in distortion measurements. Full width at half maximum (FWHM) of slice sensitivity profiles (SSP) increased with z coordinate though it seemed to be caused by other reasons than incompleteness of data. With regard to low contrast detectability, smaller objects were detected more clearly at the midplane (z = 0 mm) than at z = 40 mm, though circular-band like artifacts affected detection. The comparison between the 16-slice and the 256-slice scanners showed better performance for the 16-slice scanner regarding the SSP, low contrast detectability, and distortion. The inferiorities of the 256-slice scanner in other than distortion measurement (Feldkamp artifact) seemed to be partly caused by the prototype nature of the scanner and should be improved in the future scanner. The image noise, uniformity, and high contrast detectability were almost identical for both CTs. The 256-slice scanner was superior to the 16-slice scanner regarding the PSF, though it was caused by the smaller transverse beam width of the 256-slice scanner. In order to compare both scanners comprehensively in terms of exposure dose, noise, slice thickness, and transverse spatial resolution, K=Dsigma2ha3 was calculated, where D was exposure dose (CT dose index), sigma was magnitude of

  3. Design, Implementation, and Evaluation of a Fluorescence Laminar Optical Tomography Scanner for Brain Imaging

    Science.gov (United States)

    Sheikhzadeh, Mahya

    Recent theoretical work published in Nature Chemistry postulates the existence of cesium in high oxidation states when bonding with fluorine. It is thus predicted to behave as a p-block element (such as xenon) at pressures above 5 GPa. At these pressures, fluorine atoms may bond with the inner p-shell electrons forming CsFn, where n may vary from 2 up to 6; thus the oxidation state of Cs may change up to 6+. My research focused on physically synthesizing these compounds and to verify that, given the right conditions, bonding doesn't only occur with valence electrons, but with the inner p-shell electrons as well, much like what occurs in xenon chemistry. The difficulty of proving this experimentally is that working with fluorine is extremely difficult and dangerous, and has only been studied at high pressure in one earlier study. For the past two years our group has been working on developing a new field of science we call: Useful Hard X-ray Photochemistry. By utilizing the highly penetrating, highly focused, and highly ionizing characteristics of hard x-rays, we can decompose relatively safe and inert solid and liquid samples into simple molecules. We have successfully used our technique to produce O2, H2 , N2, Cl2, and most recently F2 in situ within a diamond anvil cell. We have also successfully and safely combusted O2 and H2 into water by creating a segregated mixture of potassium perchlorate and ammonia borate within a diamond anvil cell. We have developed a new method to produce molecular fluorine in situ, giving us a safe mechanism to supply excess fluorine that is available to react with cesium in order to experimentally verify the theoretical prediction of the unexpected stoichiometries of cesium compounds. By using techniques such as x-ray absorption fine structure spectroscopy, x-ray diffraction, and Raman spectroscopy, coupled with our new techniques of in situ hard x-ray photochemistry, we sought to experimentally demonstrate this theoretical behavior of inner shell bonding and open the door to a better understanding of chemical bonding under extreme conditions. This thesis discusses the results of our attempt to synthesize these novel CsFn (n>1) compounds.

  4. Optical properties of barcode symbols for laser scanning

    Science.gov (United States)

    Quinn, Anna M.; Eastman, Jay M.

    1991-02-01

    Not all bar code symbols are alike. This paper will discuss the characteristics of bar code symbols which can make or break a bar code laser scanner''s performance in a specific application. These characteristics can be broken down into three catergories: Substrates " inks" ( inks toners dyes etc. ) and the light source used to read the symbol. The characteristics of the substrate can be further separated into three groups: the medium used the scattering properties of the the medium and overlaminates. Intrinsic properties of the medium can include " paper noise" resulting from the grain of paper metal grain or a retro-reflective background. Scattering characteristics cover angular distribution of the scattered light absolute scatter levels from the substrate internal scatter and specularly reflected light. Overlaminates contribute their own assets and liabilities in successfully choosing a scanner that will perform for all your needs. The inks used and the light source utilized work in conjunction with each other in determining the performance of a laser scanner. The spectral characteristics and composition of the ink determine which light source the scanner must employ to be used to successfully interpret the symbol. The three common light sources available in laser bar code scanners are helium-neon lasers visible laser diodes and infra-red laser diodes. Experimental data will be presented illustrating the optical properties discussedIbove.

  5. Traceability of Height Measurements on Green Sand Molds using Optical 3D Scanning

    DEFF Research Database (Denmark)

    Mohaghegh, Kamran; Yazdanbakhsh, S.A.; Tiedje, N. S.

    2016-01-01

    (CMM) which is traceable to the meter unit. Optical scanners are increasingly used for dimensional metrology without the risk of damaging the surface, but lack of international standards makes it difficult to establish traceability of their measurements and compare them to tactile instruments....... This paper presents a metrological approach for height measurement on green sand molds using an optical 3D scanner with fringe projection. A new sand sample was developed with a hard binder to withstand the contact force of a touch probe, while keeping optical cooperativeness similar to green sand...

  6. Scanner Certification Tool for the Standardization of Digitized Documents : Focusing on Target Factors and Measurement Programs

    National Research Council Canada - National Science Library

    Hyung-Ju Park; Dong-Hwan Har

    2010-01-01

    .... Moreover, to produce a scanner certification standard, we overcome existing problems related to the growing market. We anticipate that this new standard will see a high degree of application in the current environment.

  7. Symptoms and Cognitive Effects of Exposure to Magnetic Stray Fields of MRI Scanners

    NARCIS (Netherlands)

    Vocht, Frank Gérard de

    2006-01-01

    People working routinely with magnetic resonance imaging (MRI) systems report a number of symptoms related to their presence in the inhomogeneous static magnetic fields (the stray field) surrounding these scanners. Experienced symptoms and neurobehavioral performance among engineers manufacturing

  8. 'What does a scanner see?' Techno-fascination and unreliability in the mind-game film.

    NARCIS (Netherlands)

    Schuster, L.

    2008-01-01

    In popular cinema, paranoia and conspiracy plots often go hand in hand with questions of technological innovation. For example, A Scanner Darkly (Richard Linklater, US 2006) combines issues such as audiovisual surveillance, conspiracy, and manipulation without disambiguating between paranoid delusio

  9. 'What does a scanner see?' Techno-fascination and unreliability in the mind-game film.

    NARCIS (Netherlands)

    Schuster, L.

    2008-01-01

    In popular cinema, paranoia and conspiracy plots often go hand in hand with questions of technological innovation. For example, A Scanner Darkly (Richard Linklater, US 2006) combines issues such as audiovisual surveillance, conspiracy, and manipulation without disambiguating between paranoid

  10. Symptoms and Cognitive Effects of Exposure to Magnetic Stray Fields of MRI Scanners

    NARCIS (Netherlands)

    Vocht, Frank Gérard de

    2006-01-01

    People working routinely with magnetic resonance imaging (MRI) systems report a number of symptoms related to their presence in the inhomogeneous static magnetic fields (the stray field) surrounding these scanners. Experienced symptoms and neurobehavioral performance among engineers manufacturing 0.

  11. 'What does a scanner see?' Techno-fascination and unreliability in the mind-game film.

    NARCIS (Netherlands)

    Schuster, L.

    2008-01-01

    In popular cinema, paranoia and conspiracy plots often go hand in hand with questions of technological innovation. For example, A Scanner Darkly (Richard Linklater, US 2006) combines issues such as audiovisual surveillance, conspiracy, and manipulation without disambiguating between paranoid delusio

  12. The mechatronic design of a fast wire scanner in IHEP U-70 accelerator

    Science.gov (United States)

    Baranov, V. T.; Makhov, S. S.; Savin, D. A.; Terekhov, V. I.

    2016-10-01

    This paper presents the mechatronic design of a fast wire scanner based on a servomotor. The design of the wire scanner is motivated by the need to measure the transverse profile of the high power proton and carbon beams at the IHEP U-70 accelerator. This paper formulates the requirements to the fast wire scanner system for the high intensity proton beam at the U-70 accelerator. The results on the design of electro-mechanical device for the wire scanner with a wire traveling speed 10-20 m/s are presented. The solution consists in a brushless servomotor and standard motor control electronics. High radiation levels in the accelerator enclosure dictate the use of a resolver as the position feedback element.

  13. Scanner external calibration algorithm based on fixed point in robot remanufacturing system

    Institute of Scientific and Technical Information of China (English)

    ZHU Sheng; CUI Pei-zhi; SHEN Chan-duo; GUO Ying-chun

    2005-01-01

    This paper deals with the scanner exterior calibration algorithm when the scanner is arranged by the robot and the object scanned is fixed on a rotate device in the Robot Remanufacturing System. The method of calibrating the relationship between the scanner coordinate and the robot Tool0, such as the rotation, Rx, Ry, R,, and the transformation X, Y, Z is studied. The data of Tool0 can be directly obtained from the relationship with the robot base-coordinate. So, the coordinate relationship between the scanner coordinate and the robot base coordinate can be easily gotten. This paper explains the basic algorithm theory, computing method, data collecting process and the resulted data in detail. The calibration algorithm is deduced under the orthogonal coordinate.

  14. Mobile network architecture of the long-range WindScanner system

    DEFF Research Database (Denmark)

    Vasiljevic, Nikola; Lea, Guillaume; Hansen, Per

    In this report we have presented the network architecture of the long-range WindScanner system that allows utilization of mobile network connections without the use of static public IP addresses. The architecture mitigates the issues of additional fees and contractual obligations that are linked...... to the acquisition of the mobile network connections with static public IP addresses. The architecture consists of a hardware VPN solution based on the network appliances Z1 and MX60 from Cisco Meraki with additional 3G or 4G dongles. With the presented network architecture and appropriate configuration, we fulfill...... the requirements of running the long-range WindScanner system using a mobile network such as 3G. This architecture allows us to have the WindScanners and the master computer in different geographical locations, and in general facilitates deployments of the long-range WindScanner system....

  15. Terrestrial laser scanner data from Hetch Hetchy area, Yosemite National Park, California, USA

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data are 3D point cloud data collected by laser scanner in the Hetch Hetchy area of Yosemite National Park, USA. The data were collected to assess landscape...

  16. [Determination of loganin in Cornus officinalis Sieb. et Zucc. by TLC scanner].

    Science.gov (United States)

    Li, K M; Yang, X J; Yu, M Q; Xie, C; Xu, L Z

    1994-12-01

    The content of loganin extracted from Cornus of ficinalis was determined directly on a CS-930 TLC scanner. The method is simple and sensitive, and can serve as an index for checking the quality of C. of ficinalis.

  17. Effects of injected dose, BMI and scanner type on NECR and image noise in PET imaging.

    Science.gov (United States)

    Chang, Tingting; Chang, Guoping; Kohlmyer, Steve; Clark, John W; Rohren, Eric; Mawlawi, Osama R

    2011-08-21

    Noise equivalent count rate (NECR) and image noise are two different but related metrics that have been used to predict and assess image quality, respectively. The aim of this study is to investigate, using patient studies, the relationships between injected dose (ID), body mass index (BMI) and scanner type on NECR and image noise measurements in PET imaging. Two groups of 90 patients each were imaged on a GE DSTE and a DRX PET/CT scanner, respectively. The patients in each group were divided into nine subgroups according to three BMI (20-24.9, 25-29.9, 30-45 kg m(-2)) and three ID (296-444, 444-555, 555-740 MBq) ranges, resulting in ten patients/subgroup. All PET data were acquired in 3D mode and reconstructed using the VuePoint HD® fully 3D OSEM algorithm (2 iterations, 21(DRX) or 20 (DSTE) subsets). NECR and image noise measurements for bed positions covering the liver were calculated for each patient. NECR was calculated from the trues, randoms and scatter events recorded in the DICOM header of each patient study, while image noise was determined as the standard deviation of 50 non-neighboring voxels in the liver of each patient. A t-test compared the NECR and image noise for different scanners but with the same BMI and ID. An ANOVA test on the other hand was used to compare the results of patients with different BMI but the same ID and scanner type as well as different ID but the same BMI and scanner type. As expected the t-test showed a significant difference in NECR between the two scanners for all BMI and ID subgroups. However, contrary to what is expected no such findings were observed for image noise measurement. The ANOVA results showed a statistically significant difference in both NECR and image noise among the different BMI for each ID and scanner subgroup. However, there was no statistically significant difference in NECR and image noise across different ID for each BMI and scanner subgroup. Although the GE DRX PET/CT scanner has better count rate

  18. Effects of injected dose, BMI and scanner type on NECR and image noise in PET imaging

    Science.gov (United States)

    Chang, Tingting; Chang, Guoping; Kohlmyer, Steve; Clark, John W., Jr.; Rohren, Eric; Mawlawi, Osama R.

    2011-08-01

    Noise equivalent count rate (NECR) and image noise are two different but related metrics that have been used to predict and assess image quality, respectively. The aim of this study is to investigate, using patient studies, the relationships between injected dose (ID), body mass index (BMI) and scanner type on NECR and image noise measurements in PET imaging. Two groups of 90 patients each were imaged on a GE DSTE and a DRX PET/CT scanner, respectively. The patients in each group were divided into nine subgroups according to three BMI (20-24.9, 25-29.9, 30-45 kg m-2) and three ID (296-444, 444-555, 555-740 MBq) ranges, resulting in ten patients/subgroup. All PET data were acquired in 3D mode and reconstructed using the VuePoint HD® fully 3D OSEM algorithm (2 iterations, 21(DRX) or 20 (DSTE) subsets). NECR and image noise measurements for bed positions covering the liver were calculated for each patient. NECR was calculated from the trues, randoms and scatter events recorded in the DICOM header of each patient study, while image noise was determined as the standard deviation of 50 non-neighboring voxels in the liver of each patient. A t-test compared the NECR and image noise for different scanners but with the same BMI and ID. An ANOVA test on the other hand was used to compare the results of patients with different BMI but the same ID and scanner type as well as different ID but the same BMI and scanner type. As expected the t-test showed a significant difference in NECR between the two scanners for all BMI and ID subgroups. However, contrary to what is expected no such findings were observed for image noise measurement. The ANOVA results showed a statistically significant difference in both NECR and image noise among the different BMI for each ID and scanner subgroup. However, there was no statistically significant difference in NECR and image noise across different ID for each BMI and scanner subgroup. Although the GE DRX PET/CT scanner has better count rate

  19. Two-Dimensional Metrology with Flatbed Scanners at Room and Liquid Nitrogen Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A. [CIEMAT. Madrid (Spain)

    2000-07-01

    We study the capability of the commercial flatbed scanner as a measuring instrument of two-coordinate sample both at room and liquid nitrogen temperatures. We describes simple procedure to calibrate the scanner, and the most adequate standard configuration to carry out the measurements. To illustrate the procedure, we measure the relative positions of the conductors in a cross-section of a superconducting magnet of CERN. (Author) 8 refs.

  20. Development of Monte Carlo simulations to provide scanner-specific organ dose coefficients for contemporary CT

    Science.gov (United States)

    Jansen, Jan T. M.; Shrimpton, Paul C.

    2016-07-01

    The ImPACT (imaging performance assessment of CT scanners) CT patient dosimetry calculator is still used world-wide to estimate organ and effective doses (E) for computed tomography (CT) examinations, although the tool is based on Monte Carlo calculations reflecting practice in the early 1990’s. Subsequent developments in CT scanners, definitions of E, anthropomorphic phantoms, computers and radiation transport codes, have all fuelled an urgent need for updated organ dose conversion factors for contemporary CT. A new system for such simulations has been developed and satisfactorily tested. Benchmark comparisons of normalised organ doses presently derived for three old scanners (General Electric 9800, Philips Tomoscan LX and Siemens Somatom DRH) are within 5% of published values. Moreover, calculated normalised values of CT Dose Index for these scanners are in reasonable agreement (within measurement and computational uncertainties of  ±6% and  ±1%, respectively) with reported standard measurements. Organ dose coefficients calculated for a contemporary CT scanner (Siemens Somatom Sensation 16) demonstrate potential deviations by up to around 30% from the surrogate values presently assumed (through a scanner matching process) when using the ImPACT CT Dosimetry tool for newer scanners. Also, illustrative estimates of E for some typical examinations and a range of anthropomorphic phantoms demonstrate the significant differences (by some 10’s of percent) that can arise when changing from the previously adopted stylised mathematical phantom to the voxel phantoms presently recommended by the International Commission on Radiological Protection (ICRP), and when following the 2007 ICRP recommendations (updated from 1990) concerning tissue weighting factors. Further simulations with the validated dosimetry system will provide updated series of dose coefficients for a wide range of contemporary scanners.

  1. Predicting the Impact of Full Body Scanners on Air Travel and Passenger Safety

    Science.gov (United States)

    2010-06-01

    porn is among the legal and operational issues under discussion. Simon Davies of Privacy International voiced his concern over the current privacy...May 31, 2010, from http://www.tampaairport.com/security/index.asp Travis, A. (2010). New scanners break child porn laws. Guardian.co.uk. Retrieved...May 20, 2010, from http://www.guardian.co.uk/politics/2010/jan/04/new-scanners- child- porn -laws TSA.gov, Transportaion Security Administration. (2010

  2. Preprocessing techniques to reduce atmospheric and sensor variability in multispectral scanner data.

    Science.gov (United States)

    Crane, R. B.

    1971-01-01

    Multispectral scanner data are potentially useful in a variety of remote sensing applications. Large-area surveys of earth resources carried out by automated recognition processing of these data are particularly important. However, the practical realization of such surveys is limited by a variability in the scanner signals that results in improper recognition of the data. This paper discusses ways by which some of this variability can be removed from the data by preprocessing with resultant improvements in recognition results.

  3. ANALYSIS OF THE PERFORMANCE OF A LASER SCANNER FOR PREDICTIVE AUTOMOTIVE APPLICATIONS

    OpenAIRE

    Zeisler, J; Maas, H.-G.

    2015-01-01

    In this paper we evaluate the use of a laser scanner for future advanced driver assistance systems. We focus on the important task of predicting the target vehicle for longitudinal ego vehicle control. Our motivation is to decrease the reaction time of existing systems during cut-in maneuvers of other traffic participants. A state-of-the-art laser scanner, the Ibeo Scala B2 R , is presented, providing its sensing characteristics and the subsequent high level object data output. We ev...

  4. Optimizing spatial resolution with the mechanical design of an X-ray computed tomography scanner

    Science.gov (United States)

    Harris, Lowell D.; Bernardi, Richard T.; Hughes, Simon H. C.; Slocum, Robert E.

    The most important factor limiting spatial resolution in a well-designed CT scanner - the width of the X-ray beam as it passes through the object being examined - is described. The Advanced Computed Tomography Inspection System (ACTIS), a second-generation CT scanner that has a variable geometry to allow a wide variety of objects to be scanned at peak spatial resolution, even with different radiation sources, is described.

  5. A Surface-Based Spatial Registration Method Based on Sense Three-Dimensional Scanner.

    Science.gov (United States)

    Fan, Yifeng; Xu, Xiufang; Wang, Manning

    2017-01-01

    The purpose of this study was to investigate the feasibility of a surface-based registration method based on a low-cost, hand-held Sense three-dimensional (3D) scanner in image-guided neurosurgery system. The scanner was calibrated prior and fixed on a tripod before registration. During registration, a part of the head surface was scanned at first and the spatial position of the adapter was recorded. Then the scanner was taken off from the tripod and the entire head surface was scanned by moving the scanner around the patient's head. All the scan points were aligned to the recorded spatial position to form a unique point cloud of the head by the automatic mosaic function of the scanner. The coordinates of the scan points were transformed from the device space to the adapter space by a calibration matrix, and then to the patient space. A 2-step patient-to-image registration method was then performed to register the patient space to the image space. The experimental results showed that the mean target registration error of 15 targets on the surface of the phantom was 1.61±0.09 mm. In a clinical experiment, the mean target registration error of 7 targets on the patient's head surface was 2.50±0.31 mm, which was sufficient to meet clinical requirements. It is feasible to use the Sense 3D scanner for patient-to-image registration, and the low-cost Sense 3D scanner can take the place of the current used scanner in the image-guided neurosurgery system.

  6. Development of a computed tomographic scanner for radiation therapy treatment planning.

    Science.gov (United States)

    Smith, V; Parker, D L; Stanley, J H; Phillips, T L; Boyd, D P; Kan, P T

    1980-08-01

    The authors describe a low-cost CT scanner integrated with a radiotherapy simulator and designed for treatment planning. The standard rotational gantry and x-ray tube of the simulator are used with a multiwire xenon lonization chamber and simple current-proportional readout system to measure patient attenuation, avoiding problems associated with diagnostic CT scanners in treatment planning. Although design constraints limit performance, software compensation techniques have reduced artifacts and given satisfactory images.

  7. Development of Monte Carlo simulations to provide scanner-specific organ dose coefficients for contemporary CT.

    Science.gov (United States)

    Jansen, Jan T M; Shrimpton, Paul C

    2016-07-21

    The ImPACT (imaging performance assessment of CT scanners) CT patient dosimetry calculator is still used world-wide to estimate organ and effective doses (E) for computed tomography (CT) examinations, although the tool is based on Monte Carlo calculations reflecting practice in the early 1990's. Subsequent developments in CT scanners, definitions of E, anthropomorphic phantoms, computers and radiation transport codes, have all fuelled an urgent need for updated organ dose conversion factors for contemporary CT. A new system for such simulations has been developed and satisfactorily tested. Benchmark comparisons of normalised organ doses presently derived for three old scanners (General Electric 9800, Philips Tomoscan LX and Siemens Somatom DRH) are within 5% of published values. Moreover, calculated normalised values of CT Dose Index for these scanners are in reasonable agreement (within measurement and computational uncertainties of  ±6% and  ±1%, respectively) with reported standard measurements. Organ dose coefficients calculated for a contemporary CT scanner (Siemens Somatom Sensation 16) demonstrate potential deviations by up to around 30% from the surrogate values presently assumed (through a scanner matching process) when using the ImPACT CT Dosimetry tool for newer scanners. Also, illustrative estimates of E for some typical examinations and a range of anthropomorphic phantoms demonstrate the significant differences (by some 10's of percent) that can arise when changing from the previously adopted stylised mathematical phantom to the voxel phantoms presently recommended by the International Commission on Radiological Protection (ICRP), and when following the 2007 ICRP recommendations (updated from 1990) concerning tissue weighting factors. Further simulations with the validated dosimetry system will provide updated series of dose coefficients for a wide range of contemporary scanners.

  8. Optic glioma

    Science.gov (United States)

    Glioma - optic; Optic nerve glioma; Juvenile pilocytic astrocytoma; Brain cancer - optic glioma ... Optic gliomas are rare. The cause of optic gliomas is unknown. Most optic gliomas are slow-growing ...

  9. Forest attributes estimation using aerial laser scanner and TM data

    Energy Technology Data Exchange (ETDEWEB)

    Shataee, S.

    2013-07-01

    Aim of study: The aim of this study was performance of four non-parametric algorithms including the k-NN, SVR, RF and ANN to estimate forest volume and basal area attributes using combination of Aerial Laser Scanner and Landsat- TM data. Area of study: Data in small part of a mixed managed forest in the Waldkirch region, Germany. Material and methods: The volume/ha and basal area/ha in the 411 circular plots were estimated based on DBH and height of trees using volume functions of study area. The low density ALS raw data as first and last pulses were prepared and automatically classified into vegetation and ground returns to generate two fine resolution digital terrain and surface models after noise removing. Plot-based height and density metrics were extracted from ALS data and used both separated and combined with orthorectified and processed TM bands. The algorithms implemented with different options including k-NN with different distance measures, SVR with the best regularized parameters for four kernel types, RF with regularized decision tree parameters and ANN with different types of networks. The algorithm performances were validated using computing absolute and percentage RMSe and bias on unused test samples. Main results: Results showed that among four methods, SVR using the RBF kernel could better estimate volume/ha with lower RMSe and bias (156.02 m{sup 3} ha{sup -}1 and 0.48, respectively) compared to others. In basal area/ha, k-NN could generate results with similar RMSe (11.79 m{sup 3} ha{sup -}1) but unbiased (0.03) compared to SVR with RMSe of 11.55 m{sup 3} ha{sup -}1 but slightly biased (-1.04). Research highlights: Results exposed that combining Lidar with TM data could improve estimations compared to using only Lidar or TM data. (Author)

  10. Design and experimental tests of free electron laser wire scanners

    Science.gov (United States)

    Orlandi, G. L.; Heimgartner, P.; Ischebeck, R.; Loch, C. Ozkan; Trovati, S.; Valitutti, P.; Schlott, V.; Ferianis, M.; Penco, G.

    2016-09-01

    SwissFEL is a x-rays free electron laser (FEL) driven by a 5.8 GeV linac under construction at Paul Scherrer Institut. In SwissFEL, wire scanners (WSCs) will be complementary to view-screens for emittance measurements and routinely used to monitor the transverse profile of the electron beam during FEL operations. The SwissFEL WSC is composed of an in-vacuum beam-probe—motorized by a stepper motor—and an out-vacuum pick-up of the wire signal. The mechanical stability of the WSC in-vacuum hardware has been characterized on a test bench. In particular, the motor induced vibrations of the wire have been measured and mapped for different motor speeds. Electron-beam tests of the entire WSC setup together with different wire materials have been carried out at the 250 MeV SwissFEL Injector Test Facility (SITF, Paul Scherrer Institut, CH) and at FERMI (Elettra-Sincrotrone Trieste, Italy). In particular, a comparative study of the relative measurement accuracy and the radiation-dose release of Al (99 )∶Si (1 ) and tungsten (W) wires has been carried out. On the basis of the outcome of the bench and electron-beam tests, the SwissFEL WSC can be qualified as a high resolution and machine-saving diagnostic tool in consideration of the mechanical stability of the scanning wire at the micrometer level and the choice of the wire material ensuring a drastic reduction of the radiation-dose release with respect to conventional metallic wires. The main aspects of the design, laboratory characterization and electron beam tests of the SwissFEL WSCs are presented.

  11. Transient foam flow in porous media with CAT Scanner

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dianbin; Brigham, W.E.

    1992-03-01

    Transient behavior is likely to dominate over most of the duration of a foam injection field project. Due to the lack of date, little is presently known about transient foam flow behavior. Foam flow does not follow established models such as the Buckley-Leverett theory, and no general predictive model has been derived. Therefore, both experimental data and a foam flow theory are needed. In this work, foam was injected at a constant mass rate into one-dimensional sandpacks of 1-in diameter and 24-in or 48-in length that had initially been saturate with distilled water. The system was placed in a cat Scanner. Data, obtained at room temperature and low pressure at various times, include both the pressure and saturation distributions. Pressure profiles showed that the pressure gradient is much greater behind the foam front than ahead of it. Moreover, the pressure gradients keep changing as the foam advances in the sandpack. This behavior differs from Buckley-Leverett theory. The CT scan results demonstrated gas channeling near the front, but eventually the foam block all these channels and sweeps the entire cross section after many pore volumes of injection. Three series of experiments were run: (1) surfactant adsorption measurements; (2) gas displacements of surfactant-laden solutions and (3) foam displacements. The first two series of experiments were made to provide the necessary parameters required to match the foam displacements. To this end, it was necessary to smooth the saturation history data, using a Langmuir-type formula. A theory was proposed based on the principles of the fractional flow curve construction method. This foam theory treats the foam as composed of infinitesimal slugs of gas of varying viscosities. The foam front has the lowest viscosity and foam at the injection end has the highest.

  12. Forest Attributes Estimation Using Aerial Laser Scanner and TM Data

    Directory of Open Access Journals (Sweden)

    S. Shataee Joibary

    2013-12-01

    Full Text Available Aim of study: The aim of this study was performance of four non-parametric algorithms including the k-NN, SVR, RF and ANN to estimate forest volume and basal area attributes using combination of Aerial Laser Scanner and Landsat-TM data.Area of study: Data in small part of a mixed managed forest in the Waldkirch region, Germany.Material and methods: The volume/ha and basal area/ha in the 411 circular plots were estimated based on DBH and height of trees using volume functions of study area. The low density ALS raw data as first and last pulses were prepared and automatically classified into vegetation and ground returns to generate two fine resolution digital terrain and surface models after noise removing. Plot-based height and density metrics were extracted from ALS data and used both separated and combined with orthorectified and processed TM bands. The algorithms implemented with different options including k-NN with different distance measures, SVR with the best regularized parameters for four kernel types, RF with regularized decision tree parameters and ANN with different types of networks. The algorithm performances were validated using computing absolute and percentage RMSe and bias on unused test samples.Main results: Results showed that among four methods, SVR using the RBF kernel could better estimate volume/ha with lower RMSe and bias (156.02 m3 ha–1 and 0.48, respectively compared to others. In basal area/ha, k-NN could generate results with similar RMSe (11.79 m3 ha–1 but unbiased (0.03 compared to SVR with RMSe of 11.55 m3 ha–1 but slightly biased (–1.04.Research highlights: Results exposed that combining Lidar with TM data could improve estimations compared to using only Lidar or TM data.Key words: forest attributes estimation; ALS; TM; non-parametric algorithms.

  13. Boat's hull modeling with low-cost triangulation scanners

    Science.gov (United States)

    Guidi, Gabriele; Micoli, Laura L.; Russo, Michele

    2005-01-01

    In a 3D acquisition project range maps collected around the object to be modeled, need to be integrated. With portable range cameras these range maps are taken from unknown positions and their coordinate systems are local to the sensor. The problem of unifying all the measurements in a single reference system is solved by taking contiguous range maps with a suitable overlap level; taking one map as reference and doing a rototranslation of the adjacent ones by using an "Iterative Closest Point" (ICP) method. Depending on the 3D features over the acquired surface and on the amount of overlapping, the ICP algorithm convergence can be more or less satisfactory. Anyway it always has a random component depending on measurement uncertainty. Therefore, although each individual scan has a very good accuracy, the error's propagation may produce deviations in the aligned set respect to real surface points. In this paper a systematic study of the different alignment modality and the consequent total metric distortions on the final model, is shown. In order to experiment these techniques a case-study of industrial interest was chosen: the 3D modeling of a boat's hull mold. The experiments involved a triangulation based laser scanner integrated with a digital photogrammetry system. In order to check different alignment procedures, a Laser Radar capable to scan all the object surface with a single highly accurate scan, was used to create a "gold-standard" data set. All the experiments were compared with this reference and from the comparison several interesting methodological conclusions have been obtained.

  14. Hybrid approach for attenuation correction in PET/MR scanners

    Energy Technology Data Exchange (ETDEWEB)

    Santos Ribeiro, A., E-mail: afribeiro@fc.ul.pt [Institute of Biophysics and Biomedical Engineering, Faculty of Sciences, University of Lisbon, Lisbon (Portugal); Rota Kops, E.; Herzog, H. [Institute of Neuroscience and Medicine, Forschungszentrum Juelich, Juelich (Germany); Almeida, P. [Institute of Biophysics and Biomedical Engineering, Faculty of Sciences, University of Lisbon, Lisbon (Portugal)

    2014-01-11

    Aim: Attenuation correction (AC) of PET images is still one of the major limitations of hybrid PET/MR scanners. Different methods have been proposed to obtain the AC map from morphological MR images. Although, segmentation methods normally fail to differentiate air and bone regions, while template or atlas methods usually cannot accurately represent regions anatomically different from the template image. In this study a feed forward neural network (FFNN) algorithm is presented which directly outputs the attenuation coefficients by non-linear regression of the images acquired with an ultrashort echo time (UTE) sequence guided by the template-based AC map (TAC-map). Materials and methods: MR as well as CT data were acquired in four subjects. The UTE images and the TAC-map were the inputs of the presented FFNN algorithm for training as well as classification. The resulting attenuation maps were compared with CT-based, PNN-based and TAC maps. All the AC maps were used to reconstruct the PET emission data which were then compared for the different methods. Results: For each subject dice coefficients D were calculated between each method and the respective CT-based AC maps. The resulting Ds show higher values for all FFNN-based tissues comparatively to both TAC-based and PNN-based methods, particularly for bone tissue (D=0.77, D=0.51 and D=0.71, respectively). The AC-corrected PET images with the FFNN-based map show an overall lower relative difference (RD=3.90%) than those AC-corrected with the PNN-based (RD=4.44%) or template-based (RD=4.43%) methods. Conclusion: Our results show that an enhancement of current methods can be performed by combining both information of new MR image sequence techniques and general information provided from template techniques. Nevertheless, the number of tested subjects is statistically low and current analysis for a larger dataset is being carried out.

  15. A new nonuniformity correction algorithm for infrared line scanners

    Science.gov (United States)

    Sui, Jing; Jin, Wei-qi; Dong, Li-quan; Wang, Xia

    2006-05-01

    Nonuniformity correction (NUC) is a critical task for achieving higher performances in modern infrared imaging systems. The striping fixed pattern noise produced by the scanning-type infrared imaging system can hardly be removed clearly by many scene-based non-uniformity correction methods, which can work effectively for staring focal plane arrays (FPA). We proposed an improved nonuniformity algorithm that corrects the aggregate nonuniformity by two steps for the infrared line scanners (IRLS). The novel contribution in our approach is the integration of local constant statistics (LCS) constraint and neural networks. First, the nonuniformity due to the readout electronics is corrected by treating every row of pixels as one channel and normalizing the channel outputs so that each channel produces pixels with the same mean and standard deviation as median value of the local channels statistics. Second, for IRLS every row is generated by pushbrooming one detector on line sensors, we presume each detector has one neuron with a weight and an offset as correction parameters, which can update column by column recursively at Least Mean Square sense. A one-dimensional median filter is used to produce ideal output of linear neural network and some optimization strategies are added to increase the robustness of learning process. Applications to both simulated and real infrared images demonstrated that this algorithm is self-adaptive and able to complete NUC by only one frames. If the nonuniformity is not so severe then only the first step can obtain a good correction result. Combination of two steps can achieve a higher correction level and remove stripe pattern noise clearly.

  16. An investigation of sensitivity limits in PET scanners

    Science.gov (United States)

    Eriksson, L.; Townsend, D.; Conti, M.; Eriksson, M.; Rothfuss, H.; Schmand, M.; Casey, M. E.; Bendriem, B.

    2007-10-01

    Current systems for positron emission tomography (PET) generally cover a small solid angle which implies low sensitivity and therefore patient studies are relatively lengthy with acquisition comprising multiple bed positions. For cylindrical geometry, the axial field-of-view (FOV) may be increased by incorporating additional rings of block detectors in order to increase the solid angle coverage and hence the overall sensitivity. In this study we have taken that approach to the limit and studied an ultimate configuration with an axial extent up to 1 m or more. We have estimated the point source sensitivity and the absolute sensitivity (NEMA NU-2 2001). These sensitivity values can then be converted into count rates, for a particular phantom. A system comprising three rings of blocks based on the HIREZ block detector (Siemens Molecular Imaging) with 48 blocks/ring is taken as the starting point. Additional rings of blocks are then added. The diameter of the system for this study is 85.5 cm and the axial extent ranged from 16.4 cm, that of the current HIREZ system, up to over 3 m in order to obtain data points with a solid angle close to 4 π. In all calculations, the detectors were assumed to be lutetium oxyorthosilicate (LSO) with a crystal thickness of 2 cm. The calculated count rate values are based on actual experimental data from the Siemens HIREZ scanner and then scaled based on the ratio of the calculated absolute sensitivity to the measured HIREZ absolute sensitivity. The point source sensitivity is given by the solid angle, the square of the crystal sensitivity and the square of the detector packing fraction. The point source sensitivity as a function of the axial extent shows an exponential increase reaching a limiting value as the solid angle approaches 4 π. A system with 100 cm axial extent has a solid angle of ˜75% of 4 π.

  17. High-resolution label-free vascular imaging using a commercial, clinically approved dermatological OCT scanner

    Science.gov (United States)

    Byers, R. A.; Tozer, G.; Brown, N. J.; Matcher, S. J.

    2016-02-01

    Background and Aim: Recently developed decorrelative techniques such as speckle-variance optical coherence tomography (svOCT) have demonstrated non-invasive depth-resolved imaging of the microcirculation in-vivo. However, bulk tissue motion (BTM) originating from the subject's breathing or heartbeat remains problematic at low imaging speeds, often resulting in full frame decorrelation and a loss of vascular contrast. The aim of this study was to build upon existing svOCT techniques through utilisation of a commercially available, probe-based VivoSight OCT system running at 20 kHz Axial-scan rate. Methods and results: Custom four-dimensional scanning strategies were developed and utilised in order to maximise the interframe correlation during image acquisition. Volumes of structural OCT data were collected from various anatomical regions and processed using the aforementioned svOCT algorithm to reveal angiographic information. Following data collection, three dimensional image registration and novel filtering algorithms were applied to each volume in order to ensure that BTM artefacts were sufficiently suppressed. This enabled accurate visualisation of the microcirculation within the papillary dermis, to a depth of approximately 2mm. Applications of this technique, including quantitative capillary loop density measurement and visualisation of wound healing are demonstrated and enhanced through widefield mosaicing of the svOCT data. Conclusions: Non-invasive microcirculation imaging using an FDA 510(k) approved OCT scanner such as the VivoSight allows direct clinical utilisation of these techniques, in particular for the pathological analysis of skin diseases. This research was supported by BBSRC Doctoral Training Grant: BB/F016840/1. The authors also gratefully acknowledge the use of equipment funded by MRC grant: MR/L012669/1.

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

    Science.gov (United States)

    Kusnoto, Budi; Evans, Carla A

    2002-10-01

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

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

    Science.gov (United States)

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

    2016-11-01

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

  20. Three-dimensional surface scanners compared with standard anthropometric measurements for head shape.

    Science.gov (United States)

    Beaumont, Caroline A A; Knoops, Paul G M; Borghi, Alessandro; Jeelani, N U Owase; Koudstaal, Maarten J; Schievano, Silvia; Dunaway, David J; Rodriguez-Florez, Naiara

    2017-06-01

    Three-dimensional (3D) surface imaging devices designed to capture and quantify craniofacial surface morphology are becoming more common in clinical environments. Such scanners overcome the limitations of two-dimensional photographs while avoiding the ionizing radiation of computed tomography. The purpose of this study was to compare standard anthropometric cranial measurements with measurements taken from images acquired with 3D surface scanners. Two 3D scanners of different cost were used to acquire head shape data from thirteen adult volunteers: M4D scan and Structure Sensor. Head circumference and cephalic index were measured directly on the patients as well as on 3D scans acquired with the two scanners. To compare head volume measurements with a gold standard, magnetic resonance imaging scans were used. Repeatability and accuracy of both devices were evaluated. Intra-rater repeatability for both scanners was excellent (intraclass correlation coefficients > 0.99, p < 0.001). Direct and digital measures of head circumference, cephalic index and head volume were strongly correlated (0.85 < r < 0.91, p < 0.001). Compared to direct measurements, accuracy was highest for M4D scan. Both 3D scanners provide reproducible data of head circumference, cephalic index and head volume and show a strong correlation with traditional measurements. However, care must be taken when using absolute values. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  1. POINT-BASED VERSUS PLANE-BASED SELF-CALIBRATION OF STATIC TERRESTRIAL LASER SCANNERS

    Directory of Open Access Journals (Sweden)

    J. C. K. Chow

    2012-09-01

    Full Text Available Systematic trends are apparent when studying the self-calibration residuals of many modern static terrestrial laser scanners. Since the operation of terrestrial laser scanners is comparable to an efficient robotic total station, the sensor modelling parameters are developed in the spherical coordinate system where the raw observables of the scanner are range, horizontal angle, and vertical angle. Sensor calibration parameters are already well established for both hybrid and panoramic type laser scanners through the signalized target-based self-calibration method. In this paper, a less labour-intensive and more efficient planar-feature based terrestrial laser scanner self-calibration method, which is more suitable for in-situ self-calibration, is presented. Through simulation it will be demonstrated that the point-based self-calibration and plane-based self-calibration shares many common characteristics. Plane-based self-calibration results from real data captured with the panoramic type Leica HDS6100 and hybrid type Trimble GS200 scanner are also presented to show the practicality of the proposed method and as a comparison to the point-based self-calibration.

  2. En-face coherence imaging using galvanometer scanner modulation.

    Science.gov (United States)

    Podoleanu, A G; Dobre, G M; Jackson, D A

    1998-02-01

    We introduce a novel optical path-modulation technique for a low-coherence interferometric imaging system based on transverse scanning of the target with a galvanometric scanning-mirror pair. The path modulation arises when the beam that is incident upon one of the scanning mirrors does not fall on its axis of rotation. The method is demonstrated by the production of en-face low-coherence images of different objects such as a fiber-optic tip and a human retina invivo .

  3. Optical design and development of a small barcode scanning module

    Science.gov (United States)

    Wike, Charles K., Jr.; Lindacher, Joseph M.

    1991-04-01

    High quality molded optical components and strict optomechanical tolerances have led to a new class of barcode scanner. Dynamic analysis of the scanning system and diffraction analysis of the thru focus laser spots are used to optimize the design. The outcome of this analysis is presented herein. 2 . 0

  4. XRF core scanners as a quick and good screening tool for detecting pollution in sediment cores

    Directory of Open Access Journals (Sweden)

    Belén Rubio

    2014-05-01

    Full Text Available The capabilities of X-Ray Fluorescence (XRF core scanners, to acquire high-resolution geochemical data sets in relatively short time, have made them an increasingly popular geochemical screening tool to study sediment cores for palaeoclimatologic and palaeoceanographic purposes (Peck et al., 2007; Rebolledo et al., 2008. These scanners are able to obtain optical images, X-ray radiographs, and continuous geochemical data with a maximum resolution of 200 µm directly from sediment cores (Croudace et al., 2006. Geochemical results are obtained as peak areas of counts per second that are proportional to element concentrations in the sediment, and thus the assumed semi-quantitative nature of these analyses have hampered the use of this type of instruments to monitor and detect pollution at large; where the availability of a fast screening tool that could substantially cut analytical and time costs will certainly be an advantage. This study explores the sensitivity of a ITRAX core scanner (Cox Analytical Systems on sedimentary records from estuarine-like environments in NW (Rías Baixas Galicia and SW Spain (Ría de Huelva. The Galician Rías Baixas sediments are characterized by high contents of organic matter, but in general terms, are not heavily polluted. We have selected one core in the Marín harbour (Ría de Pontevedra and another in the intertidal area of San Simón Bay (inner Ría de Vigo, close to a ceramic factory, which is relatively highly polluted by lead. By the contrary, the Ría de Huelva is one of the most polluted areas in western Europe because of the high acid mining activity together with the chemical industries located in its margins. We have selected a core in the Padre Santo Channel in the confluence of the Odiel and Tinto rivers. ITRAX sensitivity was obtained by establishing equivalences between peak areas and concentrations obtained by traditional analytical techniques such as ICP-MS, ICP-OES and/or conventional XRF of

  5. In vivo photoacoustic imaging of nude mice vasculature using a photoacoustic imaging system based on a commercial ultrasound scanner

    Science.gov (United States)

    Jankovic, Ladislav; Shahzad, Khalid; Wang, Yao; Burcher, Michael; Scholle, Frank-Detlef; Hauff, Peter; Mofina, Sabine; Skobe, Mihaela

    2008-02-01

    In-vivo photoacoustic/ultrasound (PA/US) imaging of nude mice was investigated using a photoacoustic imaging system based on a commercial ultrasound scanner HDI-5000. Raw per-channel data was captured and beamformed to generate each individual photoacoustic image with a single laser shot. An ultra-broadband CL15-7 linear array with a center frequency of 8 MHz, combined with a Schott Glass fiber bundle, was used as a compact high resolution imaging probe, with lateral and axial PA resolutions of about 300µm and 200µm, respectively. The imaging system worked in a dual PA-US mode, with the ultrasound outlining the tissue structure and the photoacoustic image showing the blood vessels. PA signals were generated by exposing mice to ultra-short optical pulses from a Nd:YAG-pumped OPO laser operating in a wavelength range of 700-950nm. The corresponding ultrasound images were generated in the regular B-mode with standard delay-and-sum beamforming algorithm. The system resolution was sufficiently high to identify and clearly distinguish the dorsal artery and the two lateral veins in the mouse tail. Both the saphena artery and the ischiatic vein on the cross-section of the mouse leg were clearly outlined in the PA images and correctly overlaid on the ultrasound image of the tissue structure. Similarly, cross-section PA images of the mouse abdomen revealed mesenteric vasculatures located below the abdominal wall. Finally, a successful PA imaging of the mouse thoracic cavity unveiled the ascending and descending aorta. These initial results demonstrate a great potential for a dual photoacoustic/ultrasound imaging modality implemented on a commercial ultrasound imaging scanner.

  6. Phantom-based comparison of the accuracy of point clouds extracted from stereo cameras and laser range scanner

    Science.gov (United States)

    Kumar, Ankur N.; Pheiffer, Thomas S.; Simpson, Amber L.; Thompson, Reid C.; Miga, Michael I.; Dawant, Benoit M.

    2013-03-01

    Using computational models, images acquired pre-operatively can be updated to account for intraoperative brain shift in image-guided surgical (IGS) systems. An optically tracked textured laser range scanner (tLRS) furnishes the 3D coordinates of cortical surface points (3D point clouds) over the surgical field of view and provides a correspondence between these and the pre-operative MR image. However, integration of the acquired tLRS data into a clinically acceptable system compatible throughout the clinical workflow of tumor resection has been challenging. This is because acquiring the tLRS data requires moving the scanner in and out of the surgical field, thus limiting the number of acquisitions. Large differences between acquisitions caused by tumor resection and tissue manipulation make it difficult to establish correspondence and estimate brain motion. An alternative to the tLRS is to use temporally dense feature-rich stereo surgical video data provided by the operating microscope. This allows for quick digitization of the cortical surface in 3D and can help continuously update the IGS system. In order to understand the tradeoffs between these approaches as input to an IGS system, we compare the accuracy of the 3D point clouds extracted from the stereo video system of the surgical microscope and the tLRS for phantom objects in this paper. We show that the stereovision system of the surgical microscope achieves accuracy in the 0.46-1.5mm range on our phantom objects and is a viable alternative to the tLRS for neurosurgical applications.

  7. Traceability of optical length measurements on sand surfaces

    DEFF Research Database (Denmark)

    Mohaghegh, Kamran; Yazdanbakhsh, Seyed Alireza; Tiedje, Niels Skat

    2016-01-01

    This work concerns traceable measurements on moulds used in automatic casting lines made of green sand, which has a very low strength against the force of a contact probe. A metrological set-up was made based on the use of calibrated workpieces following ISO 15530-3 to determine the uncertainty...... of optical measurements on a sand surface. A new customised sand sample was developed using a hard binder to withstand the contact force of a touch probe, while keeping optical cooperativeness similar to that of green sand. The length of the sample was calibrated using a dial gauge set-up. An optical 3D...... scanner with fringe pattern projection was used to measure the length of a green sand sample (soft sample) with traceability transfer through the hard sample. Results confirm that the uncertainty of the optical scanner on the substituted hard sample is similar to that of the soft sample, so the hard...

  8. Fast and accurate line scanner based on white light interferometry

    Science.gov (United States)

    Lambelet, Patrick; Moosburger, Rudolf

    2013-04-01

    White-light interferometry is a highly accurate technology for 3D measurements. The principle is widely utilized in surface metrology instruments but rarely adopted for in-line inspection systems. The main challenges for rolling out inspection systems based on white-light interferometry to the production floor are its sensitivity to environmental vibrations and relatively long measurement times: a large quantity of data needs to be acquired and processed in order to obtain a single topographic measurement. Heliotis developed a smart-pixel CMOS camera (lock-in camera) which is specially suited for white-light interferometry. The demodulation of the interference signal is treated at the level of the pixel which typically reduces the acquisition data by one orders of magnitude. Along with the high bandwidth of the dedicated lock-in camera, vertical scan-speeds of more than 40mm/s are reachable. The high scan speed allows for the realization of inspection systems that are rugged against external vibrations as present on the production floor. For many industrial applications such as the inspection of wafer-bumps, surface of mechanical parts and solar-panel, large areas need to be measured. In this case either the instrument or the sample are displaced laterally and several measurements are stitched together. The cycle time of such a system is mostly limited by the stepping time for multiple lateral displacements. A line-scanner based on white light interferometry would eliminate most of the stepping time while maintaining robustness and accuracy. A. Olszak proposed a simple geometry to realize such a lateral scanning interferometer. We demonstrate that such inclined interferometers can benefit significantly from the fast in-pixel demodulation capabilities of the lock-in camera. One drawback of an inclined observation perspective is that its application is limited to objects with scattering surfaces. We therefore propose an alternate geometry where the incident light is

  9. Performance evaluation of a high resolution dedicated breast PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    García Hernández, Trinitat, E-mail: mtrinitat@eresa.com; Vicedo González, Aurora; Brualla González, Luis; Granero Cabañero, Domingo [Department of Medical Physics, ERESA, Hospital General Universitario, Valencia 46014 (Spain); Ferrer Rebolleda, Jose; Sánchez Jurado, Raúl; Puig Cozar Santiago, Maria del [Department of Nuclear Medicine, ERESA, Hospital General Universitario, Valencia 46014 (Spain); Roselló Ferrando, Joan [Department of Medical Physics, ERESA, Hospital General Universitario, Valencia 46014 (Spain); Department of Physiology, University of Valencia, Valencia 46010 (Spain)

    2016-05-15

    Purpose: Early stage breast cancers may not be visible on a whole-body PET scan. To overcome whole-body PET limitations, several dedicated breast positron emission tomography (DbPET) systems have emerged nowadays aiming to improve spatial resolution. In this work the authors evaluate the performance of a high resolution dedicated breast PET scanner (Mammi-PET, Oncovision). Methods: Global status, uniformity, sensitivity, energy, and spatial resolution were measured. Spheres of different sizes (2.5, 4, 5, and 6 mm diameter) and various 18 fluorodeoxyglucose ({sup 18}F-FDG) activity concentrations were randomly inserted in a gelatine breast phantom developed at our institution. Several lesion-to-background ratios (LBR) were simulated, 5:1, 10:1, 20:1, 30:1, and 50:1. Images were reconstructed using different voxel sizes. The ability of experienced reporters to detect spheres was tested as a function of acquisition time, LBR, sphere size, and matrix reconstruction voxel size. For comparison, phantoms were scanned in the DbPET camera and in a whole body PET (WB-PET). Two patients who just underwent WB-PET/CT exams were imaged with the DbPET system and the images were compared. Results: The measured absolute peak sensitivity was 2.0%. The energy resolution was 24.0% ± 1%. The integral and differential uniformity were 10% and 6% in the total field of view (FOV) and 9% and 5% in the central FOV, respectively. The measured spatial resolution was 2.0, 1.9, and 1.7 mm in the radial, tangential, and axial directions. The system exhibited very good detectability for spheres ≥4 mm and LBR ≥10 with a sphere detection of 100% when acquisition time was set >3 min/bed. For LBR = 5 and acquisition time of 7 min the detectability was 100% for spheres of 6 mm and 75% for spheres of 5, 4, and 2.5 mm. Lesion WB-PET detectability was only comparable to the DbPET camera for lesion sizes ≥5 mm when acquisition time was >3 min and LBR > 10. Conclusions: The DbPET has a good

  10. Automating slope monitoring in mines with terrestrial lidar scanners

    Science.gov (United States)

    Conforti, Dario

    2014-05-01

    Static terrestrial laser scanners (TLS) have been an important component of slope monitoring for some time, and many solutions for monitoring the progress of a slide have been devised over the years. However, all of these solutions have required users to operate the lidar equipment in the field, creating a high cost in time and resources, especially if the surveys must be performed very frequently. This paper presents a new solution for monitoring slides, developed using a TLS and an automated data acquisition, processing and analysis system. In this solution, a TLS is permanently mounted within sight of the target surface and connected to a control computer. The control software on the computer automatically triggers surveys according to a user-defined schedule, parses data into point clouds, and compares data against a baseline. The software can base the comparison against either the original survey of the site or the most recent survey, depending on whether the operator needs to measure the total or recent movement of the slide. If the displacement exceeds a user-defined safety threshold, the control computer transmits alerts via SMS text messaging and/or email, including graphs and tables describing the nature and size of the displacement. The solution can also be configured to trigger the external visual/audio alarm systems. If the survey areas contain high-traffic areas such as roads, the operator can mark them for exclusion in the comparison to prevent false alarms. To improve usability and safety, the control computer can connect to a local intranet and allow remote access through the software's web portal. This enables operators to perform most tasks with the TLS from their office, including reviewing displacement reports, downloading survey data, and adjusting the scan schedule. This solution has proved invaluable in automatically detecting and alerting users to potential danger within the monitored areas while lowering the cost and work required for

  11. Indirect identification and compensation of lateral scanner resonances in atomic force microscopes.

    Science.gov (United States)

    Burns, D J; Youcef-Toumi, K; Fantner, G E

    2011-08-05

    Improving the imaging speed of atomic force microscopy (AFM) requires accurate nanopositioning at high speeds. However, high speed operation excites resonances in the AFM's mechanical scanner that can distort the image, and therefore typical users of commercial AFMs elect to operate microscopes at speeds below which scanner resonances are observed. Although traditional robust feedforward controllers and input shaping have proven effective at minimizing the influence of scanner distortions, the lack of direct measurement and use of model-based controllers have required disassembling the microscope to access lateral scanner motion with external sensors in order to perform a full system identification experiment, which places excessive demands on routine microscope operators. Further, since the lightly damped instrument dynamics often change from experiment to experiment, model-based controllers designed from offline system identification experiments must trade off high speed performance for robustness to modeling errors. This work represents a new way to automatically characterize the lateral scanner dynamics without addition of lateral sensors, and shape the commanded input signals in such a way that disturbing dynamics are not excited. Scanner coupling between the lateral and out-of-plane directions is exploited and used to build a minimal model of the scanner that is also sufficient to describe the nature of the distorting resonances. This model informs the design of an online input shaper used to suppress spectral components of the high speed command signals. The method presented is distinct from alternative approaches in that neither an information-complete system identification experiment nor microscope modification are required. Because the system identification is performed online immediately before imaging, no tradeoff of performance is required. This approach has enabled an increase in the scan rates of unmodified commercial AFMs from 1-4 lines s(-1) to

  12. Optical correlation filters for large-class OCR applications

    Science.gov (United States)

    Casasent, David P.; Iyer, Anand K.; Gopalaswamy, Srinivasan

    1991-08-01

    The performance of two new optical correlation filters (G-MACE and MINACE) for large class (many fonts and true class words) OCR (optical character recognition) applications is considered. We consider filters that can recognize many key words in upper case (UC) and mixed case (MC) and various point sizes in the presence of OCR scanner sampling errors. New results are presented and guidelines for large class filters are advanced.

  13. Video Scanning Hartmann Optical Tester (VSHOT) Uncertainty Analysis: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowski, A.; Gray, A.

    2010-10-01

    This purely analytical work is based primarily on the geometric optics of the system and shows sensitivities to various design and operational parameters. We discuss sources of error with measuring devices, instrument calibrations, and operator measurements for a parabolic trough test. In this paper, we include both the random (precision) and systematic (bias) errors for VSHOT testing and their contributions to the uncertainty. The contributing factors that we considered in this study are target tilt, target face to laser output distance, instrument vertical offset, scanner tilt, distance between the tool and the test piece, camera calibration, and scanner/calibration.

  14. Development of CT scanner models for patient organ dose calculations using Monte Carlo methods

    Science.gov (United States)

    Gu, Jianwei

    There is a serious and growing concern about the CT dose delivered by diagnostic CT examinations or image-guided radiation therapy imaging procedures. To better understand and to accurately quantify radiation dose due to CT imaging, Monte Carlo based CT scanner models are needed. This dissertation describes the development, validation, and application of detailed CT scanner models including a GE LightSpeed 16 MDCT scanner and two image guided radiation therapy (IGRT) cone beam CT (CBCT) scanners, kV CBCT and MV CBCT. The modeling process considered the energy spectrum, beam geometry and movement, and bowtie filter (BTF). The methodology of validating the scanner models using reported CTDI values was also developed and implemented. Finally, the organ doses to different patients undergoing CT scan were obtained by integrating the CT scanner models with anatomically-realistic patient phantoms. The tube current modulation (TCM) technique was also investigated for dose reduction. It was found that for RPI-AM, thyroid, kidneys and thymus received largest dose of 13.05, 11.41 and 11.56 mGy/100 mAs from chest scan, abdomen-pelvis scan and CAP scan, respectively using 120 kVp protocols. For RPI-AF, thymus, small intestine and kidneys received largest dose of 10.28, 12.08 and 11.35 mGy/100 mAs from chest scan, abdomen-pelvis scan and CAP scan, respectively using 120 kVp protocols. The dose to the fetus of the 3 month pregnant patient phantom was 0.13 mGy/100 mAs and 0.57 mGy/100 mAs from the chest and kidney scan, respectively. For the chest scan of the 6 month patient phantom and the 9 month patient phantom, the fetal doses were 0.21 mGy/100 mAs and 0.26 mGy/100 mAs, respectively. For MDCT with TCM schemas, the fetal dose can be reduced with 14%-25%. To demonstrate the applicability of the method proposed in this dissertation for modeling the CT scanner, additional MDCT scanner was modeled and validated by using the measured CTDI values. These results demonstrated that the

  15. Advanced mix-and-match using a high-NA i-line scanner

    Science.gov (United States)

    Kuijten, Jan P.; Harris, Thomas A.; van der Heijden, Ludo; Witko, David; Cossins, John; Foster, James; Ritchie, Douglas R.

    2000-07-01

    Step and Scan technology has matured for the current generation of semiconductor lithography tools and has become the standard for most new fabs and fab expansions. It is estimated that for the year 1999, more than 64 percent of new exposure tool shipments from all vendors were step and scan platforms. For economical mass production in sub 180 nm applications, DUV and i-line lithography have to be combined with critical layers that are exposure during DUV. Semi- critical and non-critical layers are exposed using i-line. The choice to use a stepper ora scanner for the i-line platform becomes critical in terms of operating cost and technical capability. This paper reports on the performance of high resolution, high throughput i-line scanners that are used in mix and match with DUV scanners. Advanced imaging capability is demonstrated on the ASML PAS 5500/400 i-line scanner as well as alignment performance on the most difficult layers using the ATHENA advanced alignment system. Matching strategies are presented along with a cost analysis showing the merits of using i-line scanners for semi- critical and non-critical layers in mix and match.

  16. Development of a mixed pixel filter for improved dimension estimation using AMCW laser scanner

    Science.gov (United States)

    Wang, Qian; Sohn, Hoon; Cheng, Jack C. P.

    2016-09-01

    Accurate dimension estimation is desired in many fields, but the traditional dimension estimation methods are time-consuming and labor-intensive. In the recent decades, 3D laser scanners have become popular for dimension estimation due to their high measurement speed and accuracy. Nonetheless, scan data obtained by amplitude-modulated continuous-wave (AMCW) laser scanners suffer from erroneous data called mixed pixels, which can influence the accuracy of dimension estimation. This study develops a mixed pixel filter for improved dimension estimation using AMCW laser scanners. The distance measurement of mixed pixels is firstly formulated based on the working principle of laser scanners. Then, a mixed pixel filter that can minimize the classification errors between valid points and mixed pixels is developed. Validation experiments were conducted to verify the formulation of the distance measurement of mixed pixels and to examine the performance of the proposed mixed pixel filter. Experimental results show that, for a specimen with dimensions of 840 mm × 300 mm, the overall errors of the dimensions estimated after applying the proposed filter are 1.9 mm and 1.0 mm for two different scanning resolutions, respectively. These errors are much smaller than the errors (4.8 mm and 3.5 mm) obtained by the scanner's built-in filter.

  17. Quantitative image reconstruction for total-body PET imaging using the 2-meter long EXPLORER scanner.

    Science.gov (United States)

    Zhang, Xuezhu; Zhou, Jian; Cherry, Simon R; Badawi, Ramsey D; Qi, Jinyi

    2017-03-21

    The EXPLORER project aims to build a 2 meter long total-body PET scanner, which will provide extremely high sensitivity for imaging the entire human body. It will possess a range of capabilities currently unavailable to state-of-the-art clinical PET scanners with a limited axial field-of-view. The huge number of lines-of-response (LORs) of the EXPLORER poses a challenge to the data handling and image reconstruction. The objective of this study is to develop a quantitative image reconstruction method for the EXPLORER and compare its performance with current whole-body scanners. Fully 3D image reconstruction was performed using time-of-flight list-mode data with parallel computation. To recover the resolution loss caused by the parallax error between crystal pairs at a large axial ring difference or transaxial radial offset, we applied an image domain resolution model estimated from point source data. To evaluate the image quality, we conducted computer simulations using the SimSET Monte-Carlo toolkit and XCAT 2.0 anthropomorphic phantom to mimic a 20 min whole-body PET scan with an injection of 25 MBq (18)F-FDG. We compare the performance of the EXPLORER with a current clinical scanner that has an axial FOV of 22 cm. The comparison results demonstrated superior image quality from the EXPLORER with a 6.9-fold reduction in noise standard deviation comparing with multi-bed imaging using the clinical scanner.

  18. Preclinical positron emission tomography scanner based on a monolithic annulus of scintillator: initial design study.

    Science.gov (United States)

    Stolin, Alexander V; Martone, Peter F; Jaliparthi, Gangadhar; Raylman, Raymond R

    2017-01-01

    Positron emission tomography (PET) scanners designed for imaging of small animals have transformed translational research by reducing the necessity to invasively monitor physiology and disease progression. Virtually all of these scanners are based on the use of pixelated detector modules arranged in rings. This design, while generally successful, has some limitations. Specifically, use of discrete detector modules to construct PET scanners reduces detection sensitivity and can introduce artifacts in reconstructed images, requiring the use of correction methods. To address these challenges, and facilitate measurement of photon depth-of-interaction in the detector, we investigated a small animal PET scanner (called AnnPET) based on a monolithic annulus of scintillator. The scanner was created by placing 12 flat facets around the outer surface of the scintillator to accommodate placement of silicon photomultiplier arrays. Its performance characteristics were explored using Monte Carlo simulations and sections of the NEMA NU4-2008 protocol. Results from this study revealed that AnnPET's reconstructed spatial resolution is predicted to be [Formula: see text] full width at half maximum in the radial, tangential, and axial directions. Peak detection sensitivity is predicted to be 10.1%. Images of simulated phantoms (mini-hot rod and mouse whole body) yielded promising results, indicating the potential of this system for enhancing PET imaging of small animals.

  19. Temporal Stability of the Velodyne HDL-64E S2 Scanner for High Accuracy Scanning Applications

    Directory of Open Access Journals (Sweden)

    Craig Glennie

    2011-03-01

    Full Text Available The temporal stability and static calibration and analysis of the Velodyne HDL‑64E S2 scanning LiDAR system is discussed and analyzed. The mathematical model for measurements for the HDL-64E S2 scanner is updated to include misalignments between the angular encoder and scanner axis of rotation, which are found to be a marginally significant source of error. It is reported that the horizontal and vertical laser offsets cannot reliably be obtained with the current calibration model due to their high correlation with the horizontal and vertical offsets. By analyzing observations from two separate HDL-64E S2 scanners it was found that the temporal stability of the horizontal angle offset is near the quantization level of the encoder, but the vertical angular offset, distance offset and distance scale are slightly larger than expected. This is felt to be due to long term variations in the scanner range, whose root cause is as of yet unidentified. Nevertheless, a temporally averaged calibration dataset for each of the scanners resulted in a 25% improvement in the 3D planar misclosure residual RMSE over the standard factory calibration model.

  20. A LabVIEW® based generic CT scanner control software platform.

    Science.gov (United States)

    Dierick, M; Van Loo, D; Masschaele, B; Boone, M; Van Hoorebeke, L

    2010-01-01

    UGCT, the Centre for X-ray tomography at Ghent University (Belgium) does research on X-ray tomography and its applications. This includes the development and construction of state-of-the-art CT scanners for scientific research. Because these scanners are built for very different purposes they differ considerably in their physical implementations. However, they all share common principle functionality. In this context a generic software platform was developed using LabVIEW® in order to provide the same interface and functionality on all scanners. This article describes the concept and features of this software, and its potential for tomography in a research setting. The core concept is to rigorously separate the abstract operation of a CT scanner from its actual physical configuration. This separation is achieved by implementing a sender-listener architecture. The advantages are that the resulting software platform is generic, scalable, highly efficient, easy to develop and to extend, and that it can be deployed on future scanners with minimal effort.

  1. Multipurpose Pressure Vessel Scanner and Photon Doppler Velocimetry

    Science.gov (United States)

    Ellis, Tayera

    2015-01-01

    Critical flight hardware typically undergoes a series of nondestructive evaluation methods to screen for defects before it is integrated into the flight system. Conventionally, pressure vessels have been inspected for flaws using a technique known as fluorescent dye penetrant, which is biased to inspector interpretation. An alternate method known as eddy current is automated and can detect small cracks better than dye penetrant. A new multipurpose pressure vessel scanner has been developed to perform internal and external eddy current scanning, laser profilometry, and thickness mapping on pressure vessels. Before this system can be implemented throughout industry, a probability of detection (POD) study needs to be performed to validate the system’s eddy current crack/flaw capabilities. The POD sample set will consist of 6 flight-like metal pressure vessel liners with defects of known size. Preparation for the POD includes sample set fabrication, system operation, procedure development, and eddy current settings optimization. For this, collaborating with subject matter experts was required. This technical paper details the preparation activities leading up to the POD study currently scheduled for winter 2015/2016. Once validated, this system will be a proven innovation for increasing the safety and reliability of necessary flight hardware.Additionally, testing of frangible joint requires Photon Doppler Velocimetry (PDV) and Digital Image Correlation instrumentation. There is often noise associated with PDV data, which necessitates a frequency modulation (FM) signal-to-noise pre-test. Generally, FM radio works by varying the carrier frequency and mixing it with a fixed frequency source, creating a beat frequency which is represented by audio frequency that can be heard between about 20 to 20,000 Hz. Similarly, PDV reflects a shifted frequency (a phenomenon known as the Doppler Effect) from a moving source and mixes it with a fixed source frequency, which results in

  2. Preliminary hyperspectral volcano observations using Airborne Radiative Spectral Scanner (ARTS)

    Science.gov (United States)

    Jitsufuchi, T.

    2008-12-01

    Airborne-imaging spectral systems can often efficiently identify volcanic phenomena that are difficult to detect by satellite imagery. Since 1990, the National Research Institute for Earth Science and Disaster Prevention (NIED) has been developing our original airborne-imaging spectral systems for volcano observations. In 2006, we developed a new airborne hyperspectral sensor, the Airborne Radiative Transfer Spectral Scanner (ARTS), for hyperspectral volcano observations. ARTS is a push-broom imaging spectrometer covering wavelengths from 380 to 1100nm (VNIR; 288 bands), 950 to 2450nm (SWIR; 101 bands), and 8000 to 11500nm (LWIR; 32 bands) and has precise position and attitude measurement systems (GPS/IMU) to achieve direct geo-correction of the acquired image. The ARTS specifications were planned to provide hyperspectral images to support developing algorithms for remotely sensing the geothermal distribution, ash- fall areas, and content of volcanic gas columns. ARTS will also be useful for operational volcanic observations to assess volcanic activity and to mitigate volcanic disasters.Before beginning the operational use of ARTS, it is important to validate its in-flight performance. Therefore, we have been conducting validation on the B200 platform. In this study, we present the results of two experiment observations, the overflight of ARTS instrument at the NIED building site on April 5, 2007, and the volcano observations flight over active volcano (Sakurajima volcano) just after its eruption on April 8, 2008. At the NIED building site, we validated the radiometric fidelity of all bands and the accuracy of geo-corrections. At the Sakurajima volcano, we tried to demonstrate the functions of ARTS, especially those for volcano observation. At the NIED building site, the validation results indicate that the geo-correction accuracy is typically less than a two-pixel difference (RMS), and that there was good agreement between the predicted radiance at the sensor and

  3. Accuracy and precision of the three-dimensional assessment of the facial surface using a 3-D laser scanner.

    Science.gov (United States)

    Kovacs, L; Zimmermann, A; Brockmann, G; Baurecht, H; Schwenzer-Zimmerer, K; Papadopulos, N A; Papadopoulos, M A; Sader, R; Biemer, E; Zeilhofer, H F

    2006-06-01

    Three-dimensional (3-D) recording of the surface of the human body or anatomical areas has gained importance in many medical specialties. Thus, it is important to determine scanner precision and accuracy in defined medical applications and to establish standards for the recording procedure. Here we evaluated the precision and accuracy of 3-D assessment of the facial area with the Minolta Vivid 910 3D Laser Scanner. We also investigated the influence of factors related to the recording procedure and the processing of scanner data on final results. These factors include lighting, alignment of scanner and object, the examiner, and the software used to convert measurements into virtual images. To assess scanner accuracy, we compared scanner data to those obtained by manual measurements on a dummy. Less than 7% of all results with the scanner method were outside a range of error of 2 mm when compared to corresponding reference measurements. Accuracy, thus, proved to be good enough to satisfy requirements for numerous clinical applications. Moreover, the experiments completed with the dummy yielded valuable information for optimizing recording parameters for best results. Thus, under defined conditions, precision and accuracy of surface models of the human face recorded with the Minolta Vivid 910 3D Scanner presumably can also be enhanced. Future studies will involve verification of our findings using test persons. The current findings indicate that the Minolta Vivid 910 3D Scanner might be used with benefit in medicine when recording the 3-D surface structures of the face.

  4. Evaluation of a rotary laser body scanner for body volume and fat assessment.

    Science.gov (United States)

    Pepper, M Reese; Freeland-Graves, Jeanne H; Yu, Wurong; Stanforth, Philip R; Xu, Bugao

    2010-07-08

    This paper reports the evaluation tests on the reliability and validity of a 3-dimensional (3D) laser body scanner for estimation of body volume and % fat. Repeated measures of body imaging were performed for reproducibility analysis. Validity of the instrument was assessed by comparison of measures of body volume by imaging to hydrodensitometry, and body fat was compared to hydrodensitometry and dual energy X-ray absorptiometry. Reproducibility analysis showed little difference between within-subjects measurements of volume (ICC ≥ 0.99, p laser body scanner and hydrodensitometry were strongly related (r = 0.99, p 0.05). These findings indicate that the 3D laser body scanner is a reliable and valid technique for the estimation of body volume. Furthermore, body imaging is an accurate measure of body fat, as compared to dual energy X-ray absorptiometry. This new instrument is promising as a quick, simple to use, and inexpensive method of body composition analysis.

  5. [Prospects of the use of mobile MRI scanner in medical service of the Armed Forces].

    Science.gov (United States)

    Troyan, V N; Dydykin, A V; Rikun, A O; Filisteev, P A; Zayats, V V; Zhigalov, A A

    2015-10-01

    Computed tomography is currently one of the most informative methods of diagnostics of a broad range of injuries and diseases, as well as an effective additional mean for various surgical interventions thank to intraoperative use. In this regard, the question of the necessity of the use of this diagnostic technology in mobile hospitals is one of the current tasks. The article analyses the experience of the use of mobile CT scanners at the medical service of the armed forces of foreign states and provides calculations indicating the necessity of the introduction of mobile CT scanners into the hospital link. The review and classification of mobile CT scanners have allowed to formulate technical requirements for their hardware capabilities, as well as to draw conclusions about the conditions of their effective use.

  6. Effective energy measurement using radiochromic film: application of a mobile scanner

    Science.gov (United States)

    Gotanda, Tatsuhiro; Katsuda, Toshizo; Gotanda, Rumi; Kuwano, Tadao; Akagawa, Takuya; Tanki, Nobuyoshi; Tabuchi, Akihiko; Shimono, Tetsunori; Kawaji, Yasuyuki; Takeda, Yoshihiro

    2016-12-01

    The effective energy calculated using the half-value layer (HVL) is an important parameter for quality assurance (QA) and quality control (QC). However constant monitoring has not been performed because measurements using an ionization chamber (IC) are time-consuming and complicated. To solve these problems, a method using radiochromic film (GAFCHROMIC EBT2 dosimetry film (GAF-EBT2) with slight energy dependency errors), a mobile scanner and step-shaped aluminum (SSAl) filter is developed. The results of the method using a mobile scanner were compared with those of the recommended method using an IC in order to evaluate its applicability. The difference ratios of the effective energies by each method using a mobile scanner with GAF-EBT2 were less than 5% compared with results of an IC. It is considered that this method offers a simple means of determining HVL for QA and QC consistently and quickly without the need for an IC dosimeter.

  7. MRI compatible small animal monitoring and trigger system for whole body scanners

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Karl-Heinz; Krumbein, Ines; Reichenbach, Juergen R. [Jena University Hospital (Germany). Medical Physics Group; Pfeiffer, Norman [Jena University Hospital (Germany). Medical Physics Group; Ernst-Abbe-Fachhochschule Jena (Germany); Herrmann, Lutz [Ernst-Abbe-Fachhochschule Jena (Germany)

    2014-03-01

    Performing magnetic resonance imaging (MRI) experiments with small animals requires continuous monitoring of vital parameters, especially the respiration rate. Clinical whole-body MR scanners represent an attractive option for preclinical imaging as dedicated animal scanners are cost-intensive in both investment and maintenance, thus limiting their availability. Even though impressive image quality is achievable with clinical MR systems in combination with special coils, their built-in physiologic monitoring and triggering units are often not suited for small animal imaging. In this work, we present a simple, MRI compatible low cost solution to monitor the respiration and heart rate of small animals in a clinical whole-body MR scanner. The recording and processing of the biosignals as well as the optimisation of the respiratory trigger generation is described. Additionally rat and mouse in-vivo MRI experiments are presented to illustrate the effectiveness of the monitoring and respiratory trigger system in suppressing motion artifacts. (orig.)

  8. On Ground Surface Extraction Using Full-Waveform Airborne Laser Scanner for Cim

    Science.gov (United States)

    Nakano, K.; Chikatsu, H.

    2015-05-01

    Satellite positioning systems such as GPS and GLONASS have created significant changes not only in terms of spatial information but also in the construction industry. It is possible to execute a suitable construction plan by using a computerized intelligent construction. Therefore, an accurate estimate of the amount of earthwork is important for operating heavy equipment, and measurement of ground surface with high accuracy is required. A full-waveform airborne laser scanner is expected to be capable of improving the accuracy of ground surface extraction for forested areas, in contrast to discrete airborne laser scanners, as technological innovation. For forested areas, fundamental studies for construction information management (CIM) were conducted to extract ground surface using full-waveform airborne laser scanners based on waveform information.

  9. ON GROUND SURFACE EXTRACTION USING FULL-WAVEFORM AIRBORNE LASER SCANNER FOR CIM

    Directory of Open Access Journals (Sweden)

    K. Nakano

    2015-05-01

    Full Text Available Satellite positioning systems such as GPS and GLONASS have created significant changes not only in terms of spatial information but also in the construction industry. It is possible to execute a suitable construction plan by using a computerized intelligent construction. Therefore, an accurate estimate of the amount of earthwork is important for operating heavy equipment, and measurement of ground surface with high accuracy is required. A full-waveform airborne laser scanner is expected to be capable of improving the accuracy of ground surface extraction for forested areas, in contrast to discrete airborne laser scanners, as technological innovation. For forested areas, fundamental studies for construction information management (CIM were conducted to extract ground surface using full-waveform airborne laser scanners based on waveform information.

  10. Risks of exposure to ionizing and millimeter-wave radiation from airport whole-body scanners.

    Science.gov (United States)

    Moulder, John E

    2012-06-01

    Considerable public concern has been expressed around the world about the radiation risks posed by the backscatter (ionizing radiation) and millimeter-wave (nonionizing radiation) whole-body scanners that have been deployed at many airports. The backscatter and millimeter-wave scanners currently deployed in the U.S. almost certainly pose negligible radiation risks if used as intended, but their safety is difficult-to-impossible to prove using publicly accessible data. The scanners are widely disliked and often feared, which is a problem made worse by what appears to be a veil of secrecy that covers their specifications and dosimetry. Therefore, for these and future similar technologies to gain wide acceptance, more openness is needed, as is independent review and regulation. Publicly accessible, and preferably peer-reviewed evidence is needed that the deployed units (not just the prototypes) meet widely-accepted safety standards. It is also critical that risk-perception issues be handled more competently.

  11. Comparison of solid shapes geometry derived by a laser scanner and a total station

    Science.gov (United States)

    Sidiropoulos, Andreas; Lakakis, Konstantinos

    2016-08-01

    The laser scanning technology has become a common method for the daily applications of a large variety of scientists and professionals. Even for more sophisticated projects, laser scanners have been proved a very useful tool at researchers' and engineers' disposal. In this paper, we investigated the ability of a laser scanner compared to the ability of a total station to provide the geometry of solids. The tests were made in the laboratory facilities of the Aristotle University of Thessaloniki, in a variety of distances between the measuring instrument and the object. The solids that were used differ in shape, material and color. The objects are a wooden cube, a metal cube and a wooden pyramid. The absolute dimensions of the solid shapes were provided by the use of a caliper and were compared to the dimensions that were calculated by the coordinates produced by the total station and laser scanner measurements.

  12. Transmitting Performance Evaluation of ASICs for CMUT-Based Portable Ultrasound Scanners

    DEFF Research Database (Denmark)

    Llimos Muntal, Pere; Diederichsen, Søren Elmin; Jørgensen, Ivan Harald Holger

    2017-01-01

    Portable ultrasound scanners (PUS) have, in recent years, raised a lot of attention, as they can potentially overcome some of the limitations of static scanners. However, PUS have a lot of design limitations including size and power consumption. These restrictions can compromise the image quality...... of the scanner. In order to overcome these restrictions, application specific integrated circuits (ASICs) are needed to implement the electronics. In this work, a comparative study of the transmitting performance of a capacitive micromachined ultrasonic transducer (CMUT) driven by a commercial generic ultrasound...... in the time and frequency domains. The difference in normalized signal amplitude evaluated at the center frequency of the CMUT is −1.9 dB and the measured bandwidth is equivalent. The ASIC consumes only 1.3% of the total power consumption used by the commercial transmitter....

  13. Design and Test of Wire-Scanners for SwissFEL

    CERN Document Server

    Orlandi, G L; Brands, H; Heimgartner, P; Ischebeck, R; Kammerer, A; Löhl, F; Lüscher, R; Mohanmurthy, P; Ozkan, C; Schlott, V; Schulz, L; Rippstein, B; Seiler, C; Trovati, S; Valitutti, P; Zimoch, D

    2016-01-01

    The SwissFEL light-facility will provide coherent X-rays in the wavelength region 7-0.7 nm and 0.7-0.1 nm. In SwissFEL, view-screens and wire-scanners will be used to monitor the transverse profile of a 200/10pC electron beam with a normalized emittance of 0.4/0.2 mm.mrad and a final energy of 5.8 GeV. Compared to view screens, wire-scanners offer a quasi-non-destructive monitoring of the beam transverse profile without suffering from possible micro-bunching of the electron beam. The main aspects of the design, laboratory characterization and beam-test of the SwissFEL wire-scanner prototype will be discussed.

  14. Effect of temperature on calibration quality of structured-light three-dimensional scanners.

    Science.gov (United States)

    Adamczyk, M; Kamiński, M; Sitnik, R; Bogdan, A; Karaszewski, M

    2014-08-10

    This paper presents the outcome of research into the effects of ambient temperature changes on structured-light three-dimensional (3D) scanners. The tests were conducted in a thermal chamber and consisted of a comparison of the 3D measurement of a special reference unit (made of a carbon composite) performed at different temperatures, with measurements performed at the calibration temperature. A contact measuring arm with temperature compensation was used as a reference. Based on the results of these experiments, we propose a method that allows us to extend the existing scanner calibration method by using a temperature-correction procedure that is based on linear and nonlinear mathematical models. An exemplary application of this procedure has shown that the range of temperatures in which scanner accuracy is within declared limits can be increased 11-fold.

  15. Effects of ramp vibrational states on flexural intrinsic vibrations in Besocke-style scanners

    Institute of Scientific and Technical Information of China (English)

    Zhang Hui; Jiang Guo-Zhu; Liu Zhao-Qun; Zhang Shu-Yi; Fan Li

    2013-01-01

    For both the vibrating and steady supporting surfaces of a scanning disk in a Besocke-style piezoelectric scanner,a theoretical model is given by considering the nonlinear lateral friction at the micro-contact interface between the positioning legs and the supporting surface.Numerical simulations demonstrate that unexpected flexural vibrations can arise from a vibrating ramp,and their frequencies are lower than the eigenfrequencies of the scanner in the linearly elastic regime.The vibrations essentially depend on 1) the vibrational states of the supporting ramp and the steel ball tips on the three piezoelectric positioning legs,and 2) the tribological characteristics of the contacts between the tips and the ramp.The results give an insight into the intrinsic vibrations of the scanners,and are applicable in designing and optimizing piezoelectric scanning systems.

  16. Flexural resonance vibrations of piezoelectric ceramic tubes in Besocke-style scanners

    Institute of Scientific and Technical Information of China (English)

    Zhang Hui; Zhang Shu-Yi; Fan Li

    2012-01-01

    Flexural resonance vibrations of piezoelectric ceramic tubes in Besocke-style scanners with nanometer resolution are studied by using an electro-mechanical coupling Timoshenko beam model.Meanwhile,the effects of friction,the first moment,and moment of inertia induced by mass loads are considered.The predicted resonance frequencies of the ceramic tubes are sensitive to not only the mechanical parameters of the scanners,but also the friction acting on the attached shaking ball and corresponding bending moment on the tubes,The theoretical results are in excellent agreement with the related experimental measurements.This model and corresponding results are applicable for optimizing the structures and performances of the scanners.

  17. A Method for Measuring Orientation within a Magnetic Resonance Imaging Scanner using Gravity and the Static Magnetic Field (VectOrient).

    Science.gov (United States)

    van Niekerk, Adam; van der Kouwe, Andre; Meintjes, Ernesta

    2017-01-25

    In MRI brain imaging, subject motion limits obtainable image clarity. Due to the hardware layout of an MRI scanner, gradient excitations can be used to rapidly detect position. Orientation, however, is more difficult to detect and is commonly calculated by comparing the position measurements of multiple spatially constrained points to a reference dataset. The result is increased size of the apparatus the subject must wear, which can influence the imaging workflow. In optical based methods marker attachment sites are limited due to the line of sight requirement between the camera and marker, and an external reference frame is introduced. To address these challenges a method called VectOrient is proposed for orientation measurement that is based on vector observations of gravity and the MRI scanner's static magnetic field. A prototype device comprising of an accelerometer, magnetometer and angular rate sensor shows good MRI compatibility. Phantom scans of a pineapple with zero scanner specific calibration achieve comparable results to a rigid body registration algorithm with deviations less than 0.8 degrees over 28 degree changes in orientation. Dynamic performance shows potential for prospective motion correction as rapid changes in orientation (peak 20 degrees per second) can be corrected. The pulse sequence implemented achieves orientation updates with a latency estimated to be less than 12.7 ms, of which only a small fraction (<1 ms) is used for computing orientation from the raw sensor signals. The device is capable of quantifying subject respiration and heart rates. The proposed approach for orientation estimation could help address some limitations of existing methods such as orientation measurement range, temporal resolution, ease of use and marker placement.

  18. MFP scanner diagnostics using a self-printed target to measure the modulation transfer function

    Science.gov (United States)

    Wang, Weibao; Bauer, Peter; Wagner, Jerry; Allebach, Jan P.

    2014-01-01

    In the current market, reduction of warranty costs is an important avenue for improving profitability by manufacturers of printer products. Our goal is to develop an autonomous capability for diagnosis of printer and scanner caused defects with mid-range laser multifunction printers (MFPs), so as to reduce warranty costs. If the scanner unit of the MFP is not performing according to specification, this issue needs to be diagnosed. If there is a print quality issue, this can be diagnosed by printing a special test page that is resident in the firmware of the MFP unit, and then scanning it. However, the reliability of this process will be compromised if the scanner unit is defective. Thus, for both scanner and printer image quality issues, it is important to be able to properly evaluate the scanner performance. In this paper, we consider evaluation of the scanner performance by measuring its modulation transfer function (MTF). The MTF is a fundamental tool for assessing the performance of imaging systems. Several ways have been proposed to measure the MTF, all of which require a special target, for example a slanted-edge target. It is unacceptably expensive to ship every MFP with such a standard target, and to expect that the customer can keep track of it. To reduce this cost, in this paper, we develop new approach to this task. It is based on a self-printed slanted-edge target. Then, we propose algorithms to improve the results using a self-printed slanted-edge target. Finally, we present experimental results for MTF measurement using self-printed targets and compare them to the results obtained with standard targets.

  19. Optimization of 3-dimensional imaging of the breast region with 3-dimensional laser scanners.

    Science.gov (United States)

    Kovacs, Laszlo; Yassouridis, Alexander; Zimmermann, Alexander; Brockmann, Gernot; Wöhnl, Antonia; Blaschke, Matthias; Eder, Maximilian; Schwenzer-Zimmerer, Katja; Rosenberg, Robert; Papadopulos, Nikolaos A; Biemer, Edgar

    2006-03-01

    The anatomic conditions of the female breast require imaging the breast region 3-dimensionally in a normal standing position for quality assurance and for surgery planning or surgery simulation. The goal of this work was to optimize the imaging technology for the mammary region with a 3-dimensional (3D) laser scanner, to evaluate the precision and accuracy of the method, and to allow optimum data reproducibility. Avoiding the influence of biotic factors, such as mobility, we tested the most favorable imaging technology on dummy models for scanner-related factors such as the scanner position in comparison with the torso and the number of scanners and single shots. The influence of different factors of the breast region, such as different breast shapes or premarking of anatomic landmarks, was also first investigated on dummies. The findings from the dummy models were then compared with investigations on test persons, and the accuracy of measurements on the virtual models was compared with a coincidence analysis of the manually measured values. The best precision and accuracy of breast region measurements were achieved when landmarks were marked before taking the shots and when shots at 30 degrees left and 30 degrees right, relative to the sagittal line, were taken with 2 connected scanners mounted with a +10-degree upward angle. However, the precision of the measurements on test persons was significantly lower than those measured on dummies. Our findings show that the correct settings for 3D imaging of the breast region with a laser scanner can achieve an acceptable degree of accuracy and reproducibility.

  20. EU Directive 2004/40: field measurements of a 1.5 T clinical MR scanner.

    Science.gov (United States)

    Riches, S F; Collins, D J; Scuffham, J W; Leach, M O

    2007-06-01

    The European Union (EU) Physical Agents (EMF) Directive [1] must be incorporated into UK law in 2008. The directive, which applies to employees working in MRI, sets legal exposure limits for two of the three types of EMF exposure employed in MRI; time-varying gradient fields and radiofrequency (RF) fields. Limits on the static field are currently not included but may be added at a later date. Conservative action values have been set for all three types of exposure including the static field. The absolute exposure limits will exclude staff from the scanner bore and adjacent areas during scanning, impacting on many clinical activities such as anaesthetic monitoring during sedated scans, paediatric scanning and interventional MRI. When the legislation comes into force, NHS Trusts, scanner companies and academic institutions will be required to show compliance with the law. We present results of initial measurements performed on a 1.5 T clinical MRI scanner. For the static field, the proposed action value is exceeded at 40 cm from the scanner bore and would be exceeded when positioning a patient for scanning. For the RF field, the action values were only exceeded within the bore at distances of 40 cm from the scanner ends during a very RF intensive sequence; MRI employees are unlikely to be in the bore during an acquisition. For the time-varying gradient fields the action values were exceeded 52 cm out from the mouth of the bore during two clinical sequences, and estimated current densities show the exposure limit to be exceeded at 40 cm for frequencies above 333 Hz. Limiting employees to distances greater than these from the scanner during acquisition will have a severe impact on the future use and development of MRI.

  1. Static field influences on transcranial magnetic stimulation: considerations for TMS in the scanner environment.

    Science.gov (United States)

    Yau, Jeffrey M; Jalinous, Reza; Cantarero, Gabriela L; Desmond, John E

    2014-01-01

    Transcranial magnetic stimulation (TMS) can be combined with functional magnetic resonance imaging (fMRI) to simultaneously manipulate and monitor human cortical responses. Although tremendous efforts have been directed at characterizing the impact of TMS on image acquisition, the influence of the scanner's static field on the TMS coil has received limited attention. The aim of this study was to characterize the influence of the scanner's static field on TMS. We hypothesized that spatial variations in the static field could account for TMS field variations in the scanner environment. Using an MRI-compatible TMS coil, we estimated TMS field strengths based on TMS-induced voltage changes measured in a search coil. We compared peak field strengths obtained with the TMS coil positioned at different locations (B0 field vs fringe field) and orientations in the static field. We also measured the scanner's static field to derive a field map to account for TMS field variations. TMS field strength scaled depending on coil location and orientation with respect to the static field. Larger TMS field variations were observed in fringe field regions near the gantry as compared to regions inside the bore or further removed from the bore. The scanner's static field also exhibited the greatest spatial variations in fringe field regions near the gantry. The scanner's static field influences TMS fields and spatial variations in the static field correlate with TMS field variations. Coil orientation changes in the B0 field did not result in substantial TMS field variations. TMS field variations can be minimized by delivering TMS in the bore or outside of the 0-70 cm region from the bore entrance. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Monte Carlo modeling of a clinical PET scanner by using the GATE dedicated computer code; Modelagem Monte Carlo de um PET Scanner clinico utilizando o codigo dedicado GATE

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Igor Fagner; Lima, Fernando Roberto de Andrade, E-mail: falima@cnen.gov.b [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Universidade de Pernambuco (UPE), Recife, PE (Brazil). Escola Politecnica; Vieira, Jose Wilson [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2011-10-26

    This paper demonstrates more possible detailed the GATE simulated architecture involved in the 4D modeling of a General Electric PET scanner, the Advance. So, it were used data present in the literature on the configuration of GE modelled PET. The obtained results which were the 3D components of PET creation, and the simulation of 4D phenomena as the source decay and the gantry whirl, exhibit the potential of tool in emission tomograph modelling

  3. Investigation on a replica step gauge for optical 3D scanning of micro parts

    DEFF Research Database (Denmark)

    Cantatore, Angela; De Chiffre, Leonardo; Carmignato, S.

    2010-01-01

    . The stability over time of the step gauge was evaluated by repetitive measurement campaigns over a period of eight months, using measurements taken with a tactile CMM and with an optical scanner. Surface cooperativeness was investigated by measuring artefact grooves and pitch and comparing results with tactile......This work deals with investigation of the stability over time and surface cooperativeness of a calibration artefact intended for optical scanner verification. A replica step gauge with 11 grooves, made of bisacryl material for dental applications (luxabite) and previously fabricated was studied...

  4. Optical characterization of high speed microscanners based on static slit profiling method

    Science.gov (United States)

    Alaa Elhady, A.; Sabry, Yasser M.; Khalil, Diaa

    2017-01-01

    Optical characterization of high-speed microscanners is a challenging task that usually requires special high speed, extremely expensive camera systems. This paper presents a novel simple method to characterize the scanned beam spot profile and size in high-speed optical scanners under operation. It allows measuring the beam profile and the spot sizes at different scanning angles. The method is analyzed theoretically and applied experimentally on the characterization of a Micro Electro Mechanical MEMS scanner operating at 2.6 kHz. The variation of the spot size versus the scanning angle, up to ±15°, is extracted and the dynamic bending curvature effect of the micromirror is predicted.

  5. 67-116 GHz optics development for ALMA band 2-3 receivers

    Science.gov (United States)

    Yagoubov, Pavel; Gonzalez, A.; Tapia, V.; Reyes, N.; Mena, F. P.; Nesti, R.; Cuttaia, F.; Ricciardi, S.; Villa, F.

    2016-12-01

    In this paper we report the first results of the optical components development and the overall optical design for a wideband receiver to simultaneously cover ALMA bands 2 and 3. Two types of feed horns and OMTs have been designed to couple to the ALMA telescope beam using a modified Fresnel lens. Both types of hardware have been manufactured and tested in a near field beam scanner. The measured beam patterns and optical efficiencies are in good agreement with simulations.

  6. A 10 MHz Bandwidth Continuous-Time Delta-Sigma Modulator for Portable Ultrasound Scanners

    DEFF Research Database (Denmark)

    Llimos Muntal, Pere; Jørgensen, Ivan Harald Holger; Bruun, Erik

    2016-01-01

    A fourth-order 1-bit continuous-time delta-sigma modulator designed in a 65 nm process for portable ultrasound scanners is presented in this paper. The loop filter consists of RCintegrators, with programmable capacitor arrays and resistors, and the quantizer is implemented with a high-speed clocked...... comparator and a pull-down clocked latch. The feedback signal is generated with voltage DACs based on transmission gates. Using this implementation, a small and low-power solution required for portable ultrasound scanner applications is achieved. The modulator has a bandwidth of 10 MHz with an oversampling...

  7. Results from the first preclinical CT scanner with grating based phase contrast and a rotating gantry

    Science.gov (United States)

    Bech, Martin; Tapfer, Arne; Velroyen, Astrid; Yaroshenko, Andre; Pauwels, Bart; Bruyndonckx, Peter; Liu, Xuan; Sasov, Alexander; Mohr, Jürgen; Walter, Marco; Pfeiffer, Franz

    2012-07-01

    After successful demonstrations of soft-tissue phase-contrast imaging with grating interferometers at synchrotron radiation sources and at laboratory based x-ray tubes, a first preclinical CT scanner with grating based phase contrast imaging modality has been constructed. The rotating gantry is equipped with a three-grating interferometer, a 50 watt tungsten anode source and a Hamamatsu flat panel detector. The total length of the interferometer is 45 cm, and the bed of the scanner is optimized for mice, with a scanning diameter of 35 mm. From one single scan both phase-contrast and standard attenuation based tomography can be attained, providing an overall gain in image contrast.

  8. Results from the first preclinical CT scanner with grating based phase contrast and a rotating gantry

    Energy Technology Data Exchange (ETDEWEB)

    Bech, Martin; Tapfer, Arne; Velroyen, Astrid; Yaroshenko, Andre; Pauwels, Bart; Bruyndonckx, Peter; Liu Xuan; Sasov, Alexander; Mohr, Juergen; Walter, Marco; Pfeiffer, Franz [Department of Physics, Technische Universitaetet Muenchen, 85748 Garching (Germany) and Medical Radiation Physics, Lund University, 22185 Lund (Germany); Bruker microCT, 2550 Kontich (Belgium); Institute of Micro Technology, Karlsruhe Institute of Technology, 76131 Karlsruhe (Germany); Microworks GmbH, 76137 Karlsruhe (Germany)

    2012-07-31

    After successful demonstrations of soft-tissue phase-contrast imaging with grating interferometers at synchrotron radiation sources and at laboratory based x-ray tubes, a first preclinical CT scanner with grating based phase contrast imaging modality has been constructed. The rotating gantry is equipped with a three-grating interferometer, a 50 watt tungsten anode source and a Hamamatsu flat panel detector. The total length of the interferometer is 45 cm, and the bed of the scanner is optimized for mice, with a scanning diameter of 35 mm. From one single scan both phase-contrast and standard attenuation based tomography can be attained, providing an overall gain in image contrast.

  9. Performance review of a slide scanner based automated counting system for PADC radon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahimi, Z.-F. [Health Protection Agency, Radiation Protection Division, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxfordshire OX11 0RQ (United Kingdom)], E-mail: fero.ibrahimi@hpa.org.uk; Miles, J.C.H. [Health Protection Agency, Radiation Protection Division, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxfordshire OX11 0RQ (United Kingdom)

    2008-08-15

    The HPA operates a radon measuring service determining the radon concentration (Bqm{sup -3}) in enclosed areas using passive PADC (CR-39) detectors. Since 2003 over 116,000 radon detectors have been analysed in the laboratory using a Nikon LS2000 slide scanner. Digital images of the etched PADC are analysed by in-house etched-track and area counting software. The slide scanner method is briefly described along with its performance across the dynamic range of the detectors. Blind Tests, validation and other quality assurance performance results are reported and discussed.

  10. Assessment of the impact of the scanner-related factors on brain morphometry analysis with Brainvisa

    Directory of Open Access Journals (Sweden)

    Shokouhi Mahsa

    2011-12-01

    Full Text Available Abstract Background Brain morphometry is extensively used in cross-sectional studies. However, the difference in the estimated values of the morphometric measures between patients and healthy subjects may be small and hence overshadowed by the scanner-related variability, especially with multicentre and longitudinal studies. It is important therefore to investigate the variability and reliability of morphometric measurements between different scanners and different sessions of the same scanner. Methods We assessed the variability and reliability for the grey matter, white matter, cerebrospinal fluid and cerebral hemisphere volumes as well as the global sulcal index, sulcal surface and mean geodesic depth using Brainvisa. We used datasets obtained across multiple MR scanners at 1.5 T and 3 T from the same groups of 13 and 11 healthy volunteers, respectively. For each morphometric measure, we conducted ANOVA analysis and verified whether the estimated values were significantly different across different scanners or different sessions of the same scanner. The between-centre and between-visit reliabilities were estimated from their contribution to the total variance, using a random-effects ANOVA model. To estimate the main processes responsible for low reliability, the results of brain segmentation were compared to those obtained using FAST within FSL. Results In a considerable number of cases, the main effects of both centre and visit factors were found to be significant. Moreover, both between-centre and between-visit reliabilities ranged from poor to excellent for most morphometric measures. A comparison between segmentation using Brainvisa and FAST revealed that FAST improved the reliabilities for most cases, suggesting that morphometry could benefit from improving the bias correction. However, the results were still significantly different across different scanners or different visits. Conclusions Our results confirm that for morphometry

  11. Laser trepanning of CFRP with a scanner head for IR and UV lasers

    Science.gov (United States)

    Anzai, Kenji; Aoyama, Mitsuaki; Fujisaki, Akira; Miyato, Taizo; Kayahara, Takashi; Harada, Yoshihisa; Niino, Hiroyuki

    2014-03-01

    The dual beam of cw-350 W single-mode near-IR fiber laser and ns-pulsed-35 W UV laser were used in the experiments for cutting. The laser beam on the sample surface was scanned with a galvanometer scanner and focused with the f-theta lens of 400 mm focal length for IR and UV laser irradiations. A prototype remote scanner head for the multiple laser irradiations has been developed for a high-quality and high-speed laser processing of carbon fiber reinforced plastics (CFRP). In this paper, we report on the laser trepanning of circular patterns on CFRP.

  12. People counting and re-identification using fusion of video camera and laser scanner

    Science.gov (United States)

    Ling, Bo; Olivera, Santiago; Wagley, Raj

    2016-05-01

    We present a system for people counting and re-identification. It can be used by transit and homeland security agencies. Under FTA SBIR program, we have developed a preliminary system for transit passenger counting and re-identification using a laser scanner and video camera. The laser scanner is used to identify the locations of passenger's head and shoulder in an image, a challenging task in crowed environment. It can also estimate the passenger height without prior calibration. Various color models have been applied to form color signatures. Finally, using a statistical fusion and classification scheme, passengers are counted and re-identified.

  13. Performance analysis of a low-cost small animal PET/SPECT scanner

    Energy Technology Data Exchange (ETDEWEB)

    Guerra, Pedro [B104 ETS de Telecomuniacion, Universidad Politecnica de Madrid, 28040 Madrid (Spain)]. E-mail: pguerra@die.upm.es; Rubio, Jose L. [B104 ETS de Telecomuniacion, Universidad Politecnica de Madrid, 28040 Madrid (Spain); Ortuno, Juan E. [B104 ETS de Telecomuniacion, Universidad Politecnica de Madrid, 28040 Madrid (Spain); Kontaxakis, Georgios [B104 ETS de Telecomuniacion, Universidad Politecnica de Madrid, 28040 Madrid (Spain); Ledesma, Maria J. [B104 ETS de Telecomuniacion, Universidad Politecnica de Madrid, 28040 Madrid (Spain); Santos, Andres [B104 ETS de Telecomuniacion, Universidad Politecnica de Madrid, 28040 Madrid (Spain)

    2007-02-01

    In this work the performance of novel small animal positron/single-photon emission (PET/SPECT) scanner is estimated via Monte Carlo simulation, considering a YAP/LSO phoswich detector. To overcome the differences between PET and SPECT and in order to simplify the design, the system implements most signal processing digitally with programmable devices. The estimated performance of the described setup, expressed in terms of spatial image resolution and sensitivity, is 1.4 mm/0.6% for PET and 2.5 mm/0.025% for SPECT, figures that are comparable with state of the art dedicated scanners.

  14. Optimal whole-body PET scanner configurations for different volumes of LSO scintillator: a simulation study.

    Science.gov (United States)

    Poon, Jonathan K; Dahlbom, Magnus L; Moses, William W; Balakrishnan, Karthik; Wang, Wenli; Cherry, Simon R; Badawi, Ramsey D

    2012-07-07

    The axial field of view (AFOV) of the current generation of clinical whole-body PET scanners range from 15-22 cm, which limits sensitivity and renders applications such as whole-body dynamic imaging or imaging of very low activities in whole-body cellular tracking studies, almost impossible. Generally, extending the AFOV significantly increases the sensitivity and count-rate performance. However, extending the AFOV while maintaining detector thickness has significant cost implications. In addition, random coincidences, detector dead time, and object attenuation may reduce scanner performance as the AFOV increases. In this paper, we use Monte Carlo simulations to find the optimal scanner geometry (i.e. AFOV, detector thickness and acceptance angle) based on count-rate performance for a range of scintillator volumes ranging from 10 to 93 l with detector thickness varying from 5 to 20 mm. We compare the results to the performance of a scanner based on the current Siemens Biograph mCT geometry and electronics. Our simulation models were developed based on individual components of the Siemens Biograph mCT and were validated against experimental data using the NEMA NU-2 2007 count-rate protocol. In the study, noise-equivalent count rate (NECR) was computed as a function of maximum ring difference (i.e. acceptance angle) and activity concentration using a 27 cm diameter, 200 cm uniformly filled cylindrical phantom for each scanner configuration. To reduce the effect of random coincidences, we implemented a variable coincidence time window based on the length of the lines of response, which increased NECR performance up to 10% compared to using a static coincidence time window for scanners with a large maximum ring difference values. For a given scintillator volume, the optimal configuration results in modest count-rate performance gains of up to 16% compared to the shortest AFOV scanner with the thickest detectors. However, the longest AFOV of approximately 2 m with

  15. Using of scanner on the evaluation of pesticides mobility by thin-layer chromatography; Utilizacao do scanner na avaliacao da mobilidade de agrotoxicos por cromatografia de camada delgada

    Energy Technology Data Exchange (ETDEWEB)

    Tornisielo, V.L.; Costa, M.A.; Furlan, G.R. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)

    1995-12-31

    Knowledge of pesticide leaching potential is an essential information to preview environmental fate. The experiment confirms the possibility of using radiochromatogram scanning as a substitute for X-ray autoradiography, when Thin Layer Chromatografy (TLC) methodogy is used to determine mobility of a pesticide. Three types of soil from Sao Paulo state and five herbicides (metolachlor, asulan, simazing, 2,4-D and trifluralin), labeled with {sup 14} C, were used. The radiochromatogram scanners permits a quick detection of the position of the radioactive spots to determine the Rf for each pesticide, while X-ray film has to be placed on the plate on the dark room for several days or weeks and then developed to detect spots, subsequently measure and calculate Rf. The results showed that the evaluation by scanner and X-ray were similar. Hence we conclude that the use of the scanner should be considered since this methodology is faster and as accurate as the X-ray methodology. (author). 4 refs, 1 fig, 2 tabs.

  16. Digital data storage of core image using high resolution full color core scanner; Kokaizodo full color scanner wo mochiita core image no digital ka

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, W.; Ujo, S.; Osato, K.; Takasugi, S. [Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan)

    1996-05-01

    This paper reports on digitization of core images by using a new type core scanner system. This system consists of a core scanner unit (equipped with a CCD camera), a personal computer and ancillary devices. This is a modification of the old type system, with measurable core length made to 100 cm/3 scans, and resolution enhanced to 5100 pixels/m (1024 pixels/m in the old type). The camera was changed to that of a color specification, and the A/D conversion was improved to 24-bit full color. As a result of carrying out a detail reproduction test on digital images of this core scanner, it was found that objects can be identified at a level of about the size of pixels constituting the image in the case when the best contrast is obtained between the objects and the background, and that in an evaluation test on visibility of concaves and convexes on core surface, reproducibility is not very good in large concaves and convexes. 2 refs., 6 figs.

  17. Perspective and potential of smart optical materials

    Science.gov (United States)

    Choi, Sang H.; Duzik, Adam J.; Kim, Hyun-Jung; Park, Yeonjoon; Kim, Jaehwan; Ko, Hyun-U.; Kim, Hyun-Chan; Yun, Sungryul; Kyung, Ki-Uk

    2017-09-01

    convex lens are reviewed, along with the newly discovered pseudo-focal point not predicted with conventional optics modeling. Micron-sized solid state beam scanner chips for laser waveguides are reviewed as well.

  18. Mathematical modelling of scanner-specific bowtie filters for Monte Carlo CT dosimetry

    Science.gov (United States)

    Kramer, R.; Cassola, V. F.; Andrade, M. E. A.; de Araújo, M. W. C.; Brenner, D. J.; Khoury, H. J.

    2017-02-01

    The purpose of bowtie filters in CT scanners is to homogenize the x-ray intensity measured by the detectors in order to improve the image quality and at the same time to reduce the dose to the patient because of the preferential filtering near the periphery of the fan beam. For CT dosimetry, especially for Monte Carlo calculations of organ and tissue absorbed doses to patients, it is important to take the effect of bowtie filters into account. However, material composition and dimensions of these filters are proprietary. Consequently, a method for bowtie filter simulation independent of access to proprietary data and/or to a specific scanner would be of interest to many researchers involved in CT dosimetry. This study presents such a method based on the weighted computer tomography dose index, CTDIw, defined in two cylindrical PMMA phantoms of 16 cm and 32 cm diameter. With an EGSnrc-based Monte Carlo (MC) code, ratios CTDIw/CTDI100,a were calculated for a specific CT scanner using PMMA bowtie filter models based on sigmoid Boltzmann functions combined with a scanner filter factor (SFF) which is modified during calculations until the calculated MC CTDIw/CTDI100,a matches ratios CTDIw/CTDI100,a, determined by measurements or found in publications for that specific scanner. Once the scanner-specific value for an SFF has been found, the bowtie filter algorithm can be used in any MC code to perform CT dosimetry for that specific scanner. The bowtie filter model proposed here was validated for CTDIw/CTDI100,a considering 11 different CT scanners and for CTDI100,c, CTDI100,p and their ratio considering 4 different CT scanners. Additionally, comparisons were made for lateral dose profiles free in air and using computational anthropomorphic phantoms. CTDIw/CTDI100,a determined with this new method agreed on average within 0.89% (max. 3.4%) and 1.64% (max. 4.5%) with corresponding data published by CTDosimetry (www.impactscan.org) for the CTDI HEAD and BODY phantoms

  19. Technology as an Occasion for Structuring: Evidence from Observations of CT Scanners and the Social Order of Radiology Departments.

    Science.gov (United States)

    Barley, Stephen R.

    1986-01-01

    New technologies such as the CT scanner are challenging traditional role relations among radiology workers and may be altering the organizational and occupational structure of radiological work. This paper expands recent sociological thought by showing how identical CT scanners occasion similar structuring processes and created divergent forms of…

  20. A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators

    National Research Council Canada - National Science Library

    Kamińska, D; Gajos, A; Czerwiński, E; Alfs, D; Bednarski, T; Białas, P; Curceanu, C; Dulski, K; Głowacz, B; Gupta-Sharma, N; Gorgol, M; Hiesmayr, B C; Jasińska, B; Korcyl, G; Kowalski, P; Krzemień, W; Krawczyk, N; Kubicz, E; Mohammed, M; Niedźwiecki, Sz; Pawlik-Niedźwiecka, M; Raczyński, L; Rudy, Z; Silarski, M; Wieczorek, A; Wiślicki, W; Zgardzińska, B; Zieliński, M; Moskal, P

    2016-01-01

    ...) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals...

  1. Efficacy of a dynamic collimator for overranging dose reduction in a second- and third-generation dual source CT scanner

    NARCIS (Netherlands)

    R. Booij (Ronald); M.L. Dijkshoorn (Marcel); M. van Straten (Marcel)

    2017-01-01

    textabstractObjectives: The purpose of this study was to assess the efficacy of the renewed dynamic collimator in a third-generation dual source CT (DSCT) scanner and to determine the improvements over the second-generation scanner. Methods: Collimator efficacy is defined as the percentage overrangi

  2. Entrance surface dose measurements using a small OSL dosimeter with a computed tomography scanner having 320 rows of detectors.

    Science.gov (United States)

    Takegami, Kazuki; Hayashi, Hiroaki; Yamada, Kenji; Mihara, Yoshiki; Kimoto, Natsumi; Kanazawa, Yuki; Higashino, Kousaku; Yamashita, Kazuta; Hayashi, Fumio; Okazaki, Tohru; Hashizume, Takuya; Kobayashi, Ikuo

    2017-03-01

    Entrance surface dose (ESD) measurements are important in X-ray computed tomography (CT) for examination, but in clinical settings it is difficult to measure ESDs because of a lack of suitable dosimeters. We focus on the capability of a small optically stimulated luminescence (OSL) dosimeter. The aim of this study is to propose a practical method for using an OSL dosimeter to measure the ESD when performing a CT examination. The small OSL dosimeter has an outer width of 10 mm; it is assumed that a partial dose may be measured because the slice thickness and helical pitch can be set to various values. To verify our method, we used a CT scanner having 320 rows of detectors and checked the consistencies of the ESDs measured using OSL dosimeters by comparing them with those measured using Gafchromic™ films. The films were calibrated using an ionization chamber on the basis of half-value layer estimation. On the other hand, the OSL dosimeter was appropriately calibrated using a practical calibration curve previously proposed by our group. The ESDs measured using the OSL dosimeters were in good agreement with the reference ESDs from the Gafchromic™ films. Using these data, we also estimated the uncertainty of ESDs measured with small OSL dosimeters. We concluded that a small OSL dosimeter can be considered suitable for measuring the ESD with an uncertainty of 30 % during CT examinations in which pitch factors below 1.000 are applied.

  3. The Potential of Light Laser Scanners Developed for Unmanned Aerial Vehicles - The Review and Accuracy

    Science.gov (United States)

    Pilarska, M.; Ostrowski, W.; Bakuła, K.; Górski, K.; Kurczyński, Z.

    2016-10-01

    Modern photogrammetry and remote sensing have found small Unmanned Aerial Vehicles (UAVs) to be a valuable source of data in various branches of science and industry (e.g., agriculture, cultural heritage). Recently, the growing role of laser scanning in the application of UAVs has also been observed. Laser scanners dedicated to UAVs consist of four basic components: a laser scanner (LiDAR), an Inertial Measurement Unit (IMU), a Global Navigation Satellite System (GNSS) receiver and an on-board computer. The producers of the system provide users with detailed descriptions of the accuracies separately for each component. However, the final measurement accuracy is not given. This paper reviews state-of-the-art of laser scanners developed specifically for use on a UAV, presenting an overview of several constructions that are available nowadays. The second part of the paper is focussed on analysing the influence of the sensor accuracies on the final measurement accuracy. Mathematical models developed for Airborne Laser Scanning (ALS) accuracy analyses are used to estimate the theoretical accuracies of different scanners with conditions typical for UAV missions. Finally, the theoretical results derived from the mathematical simulations are compared with an experimental use case.

  4. Addressing Spatial Variability of Surface-Layer Wind with Long-Range WindScanners

    DEFF Research Database (Denmark)

    Berg, Jacob; Vasiljevic, Nikola; Kelly, Mark C.;

    2015-01-01

    This paper presents an analysis of mean wind measurements from a coordinated system of long-range WindScanners. From individual scan patterns the mean wind field was reconstructed over a large area, and hence it highlights the spatial variability. From comparison with sonic anemometers, the quality...

  5. Robustness of intrinsic connectivity networks in the human brain to the presence of acoustic scanner noise

    NARCIS (Netherlands)

    Langers, Dave R. M.; van Dijk, Pim

    2011-01-01

    Evoked responses in functional magnetic resonance imaging (fMRI) are affected by the presence of acoustic scanner noise (ASN). Particularly, stimulus-related activation of the auditory system and deactivation of the default mode network have repeatedly been shown to diminish. In contrast, little is

  6. Rapid, high-accuracy detection of strabismus and amblyopia using the pediatric vision scanner

    NARCIS (Netherlands)

    S.E. Loudon (Sjoukje); C.A. Rook (Caitlin); D.S. Nassif (Deborah); N.V. Piskun (Nadya); D.G. Hunter (David)

    2011-01-01

    textabstractPurpose. The Pediatric Vision Scanner (PVS) detects strabismus by identifying ocular fixation in both eyes simultaneously. This study was undertaken to assess the ability of the PVS to identify patients with amblyopia or strabismus, particularly anisometropic amblyopia with no measurable

  7. Three-dimensional surface scanners compared with standard anthropometric measurements for head shape

    NARCIS (Netherlands)

    Beaumont, C.A.A. (Caroline A.A.); Knoops, P.G.M. (Paul G.M.); Borghi, A. (Alessandro); Jeelani, N.U.O. (N.U. Owase); M.J. Koudstaal (Maarten); S. Schievano (Silvia); D.J. Dunaway (David); Rodriguez-Florez, N. (Naiara)

    2017-01-01

    textabstractThree-dimensional (3D) surface imaging devices designed to capture and quantify craniofacial surface morphology are becoming more common in clinical environments. Such scanners overcome the limitations of two-dimensional photographs while avoiding the ionizing radiation of computed

  8. Three-dimensional surface scanners compared with standard anthropometric measurements for head shape

    NARCIS (Netherlands)

    Beaumont, C.A.A. (Caroline A.A.); Knoops, P.G.M. (Paul G.M.); Borghi, A. (Alessandro); Jeelani, N.U.O. (N.U. Owase); M.J. Koudstaal (Maarten); S. Schievano (Silvia); D.J. Dunaway (David); Rodriguez-Florez, N. (Naiara)

    2016-01-01

    textabstractThree-dimensional (3D) surface imaging devices designed to capture and quantify craniofacial surface morphology are becoming more common in clinical environments. Such scanners overcome the limitations of two-dimensional photographs while avoiding the ionizing radiation of computed

  9. Data Acquisition and Image Reconstruction Systems from the miniPET Scanners to the CARDIOTOM Camera

    Science.gov (United States)

    Valastván, I.; Imrek, J.; Hegyesi, G.; Molnár, J.; Novák, D.; Bone, D.; Kerek, A.

    2007-11-01

    Nuclear imaging devices play an important role in medical diagnosis as well as drug research. The first and second generation data acquisition systems and the image reconstruction library developed provide a unified hardware and software platform for the miniPET-I, miniPET-II small animal PET scanners and for the CARDIOTOM™.

  10. 2D X-ray scanner and its uses in laboratory reservoir characterization measurements

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, D.; Doggett, K.

    1997-08-01

    X-ray techniques are used in petroleum laboratories for a variety of reservoir characterization measurements. This paper describes the configuration of a 2D X-ray scanner and many of the ways in which it simplifies and improves accuracy`s of laboratory measurements. Linear X-ray scanners are most often used to provide descriptions of fluid saturations within core plugs during flow tests. We configured our linear scanner for both horizontal and vertical movement. Samples can be scanned horizontally, vertically, or according to horizontal and vertical grids. X-ray measurements are fast, allowing measurements of two- and three-phase fluid saturations during both steady- and unsteady-state flow processes. Rock samples can be scanned while they are subjected to stress, pore pressure, and temperature conditions simulating those of a petroleum reservoir. Many types of measurements are possible by selecting appropriate X-ray power settings, dopes, filters, and collimator configurations. The scanner has been used for a variety of applications besides fluid saturation measurements. It is useful for measuring porosity distributions in rocks, concentrations of X-ray dopes within flow streams during tracer tests, gap widths in fracture flow cells, fluid interface levels in PVT cells and fluid separators, and other features and phenomena.

  11. Spatial resolution and sensitivity of the Inveon small-animal PET scanner.

    NARCIS (Netherlands)

    Visser, E.P.; Disselhorst, J.; Brom, M.; Laverman, P.; Gotthardt, M.; Oyen, W.J.G.; Boerman, O.C.

    2009-01-01

    The Inveon small-animal PET scanner is characterized by a large, 127-mm axial length and a 161-mm crystal ring diameter. The associated high sensitivity is obtained by using all lines of response (LORs) up to the maximum ring difference (MRD) of 79, for which the most oblique LORs form acceptance an

  12. A Movable Phantom Design for Quantitative Evaluation of Motion Correction Studies on High Resolution PET Scanners

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Svarer, C.; Sibomana, M.;

    2010-01-01

    Head movements during brain imaging using high resolution positron emission tomography (PET) impair the image quality which, along with the improvement of the spatial resolution of PET scanners, in general, raises the importance of motion correction. Here, we present a new design for an automatic...

  13. Spatial resolution of the HRRT PET scanner using 3D-OSEM PSF reconstruction

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Sibomana, Merence; Keller, Sune Høgild;

    2009-01-01

    The spatial resolution of the Siemens High Resolution Research Tomograph (HRRT) dedicated brain PET scanner installed at Copenhagen University Hospital (Rigshospitalet) was measured using a point-source phantom with high statistics. Further, it was demonstrated how the newly developed 3D-OSEM PSF...

  14. Modeling and Calibration of a Novel One-Mirror Galvanometric Laser Scanner.

    Science.gov (United States)

    Yu, Chengyi; Chen, Xiaobo; Xi, Juntong

    2017-01-15

    A laser stripe sensor has limited application when a point cloud of geometric samples on the surface of the object needs to be collected, so a galvanometric laser scanner is designed by using a one-mirror galvanometer element as its mechanical device to drive the laser stripe to sweep along the object. A novel mathematical model is derived for the proposed galvanometer laser scanner without any position assumptions and then a model-driven calibration procedure is proposed. Compared with available model-driven approaches, the influence of machining and assembly errors is considered in the proposed model. Meanwhile, a plane-constraint-based approach is proposed to extract a large number of calibration points effectively and accurately to calibrate the galvanometric laser scanner. Repeatability and accuracy of the galvanometric laser scanner are evaluated on the automobile production line to verify the efficiency and accuracy of the proposed calibration method. Experimental results show that the proposed calibration approach yields similar measurement performance compared with a look-up table calibration method.

  15. Modeling and Calibration of a Novel One-Mirror Galvanometric Laser Scanner

    Directory of Open Access Journals (Sweden)

    Chengyi Yu

    2017-01-01

    Full Text Available A laser stripe sensor has limited application when a point cloud of geometric samples on the surface of the object needs to be collected, so a galvanometric laser scanner is designed by using a one-mirror galvanometer element as its mechanical device to drive the laser stripe to sweep along the object. A novel mathematical model is derived for the proposed galvanometer laser scanner without any position assumptions and then a model-driven calibration procedure is proposed. Compared with available model-driven approaches, the influence of machining and assembly errors is considered in the proposed model. Meanwhile, a plane-constraint-based approach is proposed to extract a large number of calibration points effectively and accurately to calibrate the galvanometric laser scanner. Repeatability and accuracy of the galvanometric laser scanner are evaluated on the automobile production line to verify the efficiency and accuracy of the proposed calibration method. Experimental results show that the proposed calibration approach yields similar measurement performance compared with a look-up table calibration method.

  16. Spatial resolution and sensitivity of the Inveon small-animal PET scanner.

    NARCIS (Netherlands)

    Visser, E.P.; Disselhorst, J.; Brom, M.; Laverman, P.; Gotthardt, M.; Oyen, W.J.G.; Boerman, O.C.

    2009-01-01

    The Inveon small-animal PET scanner is characterized by a large, 127-mm axial length and a 161-mm crystal ring diameter. The associated high sensitivity is obtained by using all lines of response (LORs) up to the maximum ring difference (MRD) of 79, for which the most oblique LORs form acceptance

  17. Comparison of H-infinity control and generalized predictive control for a laser scanner system

    DEFF Research Database (Denmark)

    Ordys, A.W.; Stoustrup, Jakob; Smillie, I.

    2000-01-01

    This paper describes tests performed on a laser scanner system to assess the feasibility of H-infinity control and generalized predictive control design techniques in achieving a required performance in a trajectory folowing problem. The two methods are compared with respect to achieved scan times...

  18. Cantilevered bimorph-based scanner for high speed atomic force microscopy with large scanning range.

    Science.gov (United States)

    Zhou, Yusheng; Shang, Guangyi; Cai, Wei; Yao, Jun-en

    2010-05-01

    A cantilevered bimorph-based resonance-mode scanner for high speed atomic force microscope (AFM) imaging is presented. The free end of the bimorph is used for mounting a sample stage and the other one of that is fixed on the top of a conventional single tube scanner. High speed scanning is realized with the bimorph-based scanner vibrating at resonant frequency driven by a sine wave voltage applied to one piezolayer of the bimorph, while slow scanning is performed by the tube scanner. The other piezolayer provides information on vibration amplitude and phase of the bimorph itself simultaneously, which is used for real-time data processing and image calibration. By adjusting the free length of the bimorph, the line scan rate can be preset ranging from several hundred hertz to several kilohertz, which would be beneficial for the observation of samples with different properties. Combined with a home-made AFM system and a commercially available data acquisition card, AFM images of various samples have been obtained, and as an example, images of the silicon grating taken at a line rate of 1.5 kHz with the scan size of 20 microm are given. By manually moving the sample of polished Al foil surface while scanning, the capability of dynamic imaging is demonstrated.

  19. Wide-area scanner for high-speed atomic force microscopy.

    Science.gov (United States)

    Watanabe, Hiroki; Uchihashi, Takayuki; Kobashi, Toshihide; Shibata, Mikihiro; Nishiyama, Jun; Yasuda, Ryohei; Ando, Toshio

    2013-05-01

    High-speed atomic force microscopy (HS-AFM) has recently been established. The dynamic processes and structural dynamics of protein molecules in action have been successfully visualized using HS-AFM. However, its maximum scan ranges in the X- and Y-directions have been limited to ~1 μm and ~4 μm, respectively, making it infeasible to observe the dynamics of much larger samples, including live cells. Here, we develop a wide-area scanner with a maximum XY scan range of ~46 × 46 μm(2) by magnifying the displacements of stack piezoelectric actuators using a leverage mechanism. Mechanical vibrations produced by fast displacement of the X-scanner are suppressed by a combination of feed-forward inverse compensation and the use of triangular scan signals with rounded vertices. As a result, the scan speed in the X-direction reaches 6.3 mm/s even for a scan size as large as ~40 μm. The nonlinearity of the X- and Y-piezoelectric actuators' displacements that arises from their hysteresis is eliminated by polynomial-approximation-based open-loop control. The interference between the X- and Y-scanners is also eliminated by the same technique. The usefulness of this wide-area scanner is demonstrated by video imaging of dynamic processes in live bacterial and eukaryotic cells.

  20. Measuring Short- and Long-run Promotional Effectiveness on Scanner Data Using Persistence Modeling

    NARCIS (Netherlands)

    M.G. Dekimpe (Marnik); D.M. Hanssens (Dominique); V.R. Nijs; J-B.E.M. Steenkamp (Jan-Benedict)

    2003-01-01

    textabstractThe use of price promotions to stimulate brand and firm performance is increasing. We discuss how (i) the availability of longer scanner data time series, and (ii) persistence modeling, have lead to greater insights into the dynamic effects of price promotions, as one can now quantify th

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

    Science.gov (United States)

    Polo, María-Eugenia; Felicísimo, Angel M

    2012-01-01

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

  2. Work-related factors associated with occupational exposure to static magnetic stray fields from MRI scanners

    NARCIS (Netherlands)

    Schaap, Kristel; Christopher-De Vries, Yvette; Cambron-Goulet, Évelyne; Kromhout, Hans

    2016-01-01

    PURPOSE: This study aims to identify work-related and personal factors associated with workers' exposure to static magnetic fields (SMF) and motion-induced time-varying magnetic fields (TVMF) from MRI scanners. METHODS: Measurements of personal exposure to SMF and TVMF were performed among MRI staff

  3. Inter-laboratory comparison of medical computed tomography (CT) scanners for industrial applications in the slaughterhouses

    DEFF Research Database (Denmark)

    Christensen, Lars Bager; Angel, Jais Andreas Breusch

    2013-01-01

    differences in CT performance. The presented Round Robin scheme has demonstrated its potential as such a method. The benefit of the phantom set is that it provides a convenient way of comparing volume determination between different CT scanners. The suggested phantoms are mimicking important carcass features...

  4. Description and evaluation of the high quality photogrammetric scanner UltraScan 5000

    Science.gov (United States)

    Gruber, Michael; Leberl, Franz

    Scanning of analogue images has become a key hardware technology specific to modern digital photogrammetry. Since specialised photogrammetric scanners have been introduced in the late 1980s, a gradual development and improvement of their performance regarding hardware, software and functionality, and productivity has been observed. Originally, geometric accuracy of scanners was the overriding specification for scanners. This is increasingly being augmented by a concern for good colour and radiometric performance. This article describes the UltraScan 5000, a modern photogrammetric scanner manufactured by Vexcel Imaging Austria, and its features, assesses its radiometric and geometric performance with various well-founded tests, and discusses its versatility and use in production. The UltraScan 5000 was introduced in November 1998 and since then, a surprisingly large number of systems has been installed worldwide. Their successful operation illustrates on a daily basis the validity of the technical solution and tests at user sites have confirmed a good to excellent performance regarding geometric accuracy and resolution, radiometric performance (noise, dynamic range) and colour rendition.

  5. Evaluation of image quality and dose on a flat-panel CT-scanner

    Science.gov (United States)

    Grasruck, M.; Suess, Ch.; Stierstorfer, K.; Popescu, S.; Flohr, T.

    2005-04-01

    We developed and evaluated a prototype flat-panel detector based Volume CT (VCT) scanner. We focused on improving the image quality using different detector settings and reducing x-ray scatter intensities. For the presented results we used a Varian 4030CB flat-panel detector mounted in a multislice CT-gantry (Siemens Medical Systems). The scatter intensities may severely impair image quality in flat-panel detector CT systems. To reduce the impact of scatter we tested bowtie shaped filters, anti-scatter grids and post-processing correction algorithms. We evaluated the improvement of image quality by each method and also by a combination of the several methods. To achieve an extended dynamic range in the projection data, we implemented a novel dynamic gain-switching mode. The read out charge amplifier feedback capacitance is changing dynamically in this mode, depending on the signal level. For this scan mode dedicated corrections in the offset and gain calibration are required. We compared image quality in terms of low contrast for both, the dynamic mode and the standard fixed gain mode. VCT scanners require different types of dose parameters. We measured the dose in a 16 cm CTDI phantom and free air in the scanners iso-center and defined a new metric for a VCT dose index (VCTDI). The dose for a high quality VCT scan of this prototype scanner varied between 15 and 40 mGy.

  6. A preliminary report of multispectral scanner data from the Cleveland harbor study

    Science.gov (United States)

    Shook, D.; Raquet, C.; Svehla, R.; Wachter, D.; Salzman, J.; Coney, T.; Gedney, D.

    1975-01-01

    Imagery obtained from an airborne multispectral scanner is presented. A synoptic view of the entire study area is shown for a number of time periods and for a number of spectral bands. Using several bands, sediment distributions, thermal plumes, and Rhodamine B dye distributions are shown.

  7. Preliminary results of a proficiency testing of industrial CT scanners using small polymer items

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; Cantatore, Angela; De Chiffre, Leonardo

    2012-01-01

    This work presents preliminary results concerning a proficiency testing for intercomparison of industrial CT scanners. Two audit items, similar to common industrial parts, were selected for circulation. The two items were a single polymer complex geometry part and a simple geometry item made of two...

  8. Modeling and Calibration of a Novel One-Mirror Galvanometric Laser Scanner

    Science.gov (United States)

    Yu, Chengyi; Chen, Xiaobo; Xi, Juntong

    2017-01-01

    A laser stripe sensor has limited application when a point cloud of geometric samples on the surface of the object needs to be collected, so a galvanometric laser scanner is designed by using a one-mirror galvanometer element as its mechanical device to drive the laser stripe to sweep along the object. A novel mathematical model is derived for the proposed galvanometer laser scanner without any position assumptions and then a model-driven calibration procedure is proposed. Compared with available model-driven approaches, the influence of machining and assembly errors is considered in the proposed model. Meanwhile, a plane-constraint-based approach is proposed to extract a large number of calibration points effectively and accurately to calibrate the galvanometric laser scanner. Repeatability and accuracy of the galvanometric laser scanner are evaluated on the automobile production line to verify the efficiency and accuracy of the proposed calibration method. Experimental results show that the proposed calibration approach yields similar measurement performance compared with a look-up table calibration method. PMID:28098844

  9. SOIMUMPs micromirror scanner and its application in laser line generator

    Science.gov (United States)

    Zuo, Hui; Nia, Farzad Hossein; He, Siyuan

    2017-01-01

    A SOIMUMPs 1-D rotation micromirror is presented. The micromirror is driven by electrostatic vertical comb-drive actuators to work at resonant mode to scan a laser beam. The residual stress in the metal film coated on the SOI device layer is used to generate vertical offset in the comb-drive actuators with the combs located far from the rotation axis to increase the torque. A concave lens is designed to put after the micromirror to amplify the laser beam scanning angle, as well as to compensate for the curvature of the micromirror. A micromirror-based scanning system is used to build a laser line generator with a continuously adjustable fan angle, which solves the limitation of a fixed fan angle in conventional laser line generators. Prototypes of the micromirror and the laser line generator are fabricated and measured. A driving circuit that can generate a high-voltage square wave driving signal with adjustable amplitude and frequency is designed. All the parts are integrated in a 44 mm×88 mm×44 mm box and powered with a single 5-V power supply. The optical scanning angle under 100 V with or without the concave lens is 27 deg and 12 deg, respectively, at a resonant frequency of 900 Hz.

  10. Computed tomography dose measurements with radiochromic films and a flatbed scanner.

    Science.gov (United States)

    Rampado, O; Garelli, E; Ropolo, R

    2010-01-01

    Gafchromic XR-QA films were developed for patient dosimetry in diagnostic radiology. A possible application of these films is the measurement of doses in computed tomography. In this study a method to evaluate the CTDI using Gafchromic XR-QA film and a flatbed scanner was developed and tested. Film samples were cut to dimensions of 6 x 170 mm2 in order to have an integration area similar to that of a pencil ionization chamber, with the possibility of changing the integration length. Prior to exposing these films to a computed tomography beam, the angular dependence of the film dose response was investigated by exposing film strips to a static x-ray beam at different angles in the range 0 degrees-180 degrees. A difference of 49% was found between the response with the axis beam parallel to the film surface (90 degrees) and with the axis beam perpendicular (0 degrees and 180 degrees). Integrating over a 360 degrees exposure like the one in computed tomography, a difference of less than 2% was estimated, which is comparable with the measurement error obtainable with XR-QA film. A calibration with a CT beam in the scout mode was performed and film strips were then exposed to single axial scans and to helical scans both in air and in phantoms. Two different types of flatbed scanners were used to read the film samples, a Microtek ScanMaker 9800XL scanner and an Epson Expression 10000 XL scanner, and the accuracy of the results were compared. For beam collimations above 10 mm differences between CTDI measured by film and CTDI measured by ionization chamber below 9% were found for the Epson scanner, with an average estimated error at 1 sigma level of 5%. For the Microtek scanner and for the same film samples, differences below 11% with an average error at 1 sigma level of 8% were founded. The 1 sigma uncertainty of the measured CTDI was provided by the method for each measurement, and it was shown that about the 95% of the differences between the CTDI measurements with

  11. Rotary-scanning optical resolution photoacoustic microscopy

    Science.gov (United States)

    Qi, Weizhi; Xi, Lei

    2016-10-01

    Optical resolution photoacoustic microscopy (ORPAM) is currently one of the fastest evolving photoacoustic imaging modalities. It has a comparable spatial resolution to pure optical microscopic techniques such as epifluorescence microscopy, confocal microscopy, and two-photon microscopy, but also owns a deeper penetration depth. In this paper, we report a rotary-scanning (RS)-ORPAM that utilizes a galvanometer scanner integrated with objective to achieve rotary laser scanning. A 15 MHz cylindrically focused ultrasonic transducer is mounted onto a motorized rotation stage to follow optical scanning traces synchronously. To minimize the loss of signal to noise ratio, the acoustic focus is precisely adjusted to reach confocal with optical focus. Black tapes and carbon fibers are firstly imaged to evaluate the performance of the system, and then in vivo imaging of vasculature networks inside the ears and brains of mice is demonstrated using this system.

  12. A count-rate model for PET scanners using pixelated Anger-logic detectors with different scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Surti, S; Karp, J S [Department of Radiology, University of Pennsylvania, 110 Donner Building (HUP), 3400 Spruce Street, Philadelphia, PA 19104 (United States)

    2005-12-07

    A high count-rate simulation (HCRSim) model has been developed so that all results are derived from fundamental physics principles. Originally developed to study the behaviour of continuous sodium iodide (NaI(Tl)) detectors, this model is now applied to PET scanners based on pixelated Anger-logic detectors using lanthanum bromide (LaBr{sub 3}), gadolinium orthosilicate (GSO) and lutetium orthosilicate (LSO) scintillators. This simulation has been used to study the effect on scanner deadtime and pulse pileup at high activity levels due to the scintillator stopping power ({mu}), decay time ({tau}) and energy resolution. Simulations were performed for a uniform 20 cm diameter x 70 cm long cylinder (NEMA NU2-2001 standard) in a whole-body scanner with an 85 cm ring diameter and a 25 cm axial field-of-view. Our results for these whole-body scanners demonstrate the potential of a pixelated Anger-logic detector and the relationship of its performance with the scanner NEC rate. Faster signal decay and short coincidence timing window lead to a reduction in deadtime and randoms fraction in the LaBr{sub 3} and LSO scanners compared to GSO. The excellent energy resolution of LaBr{sub 3} leads to the lowest scatter fraction for all scanners and helps compensate for reduced sensitivity compared to the GSO and LSO scanners, leading to the highest NEC values at high activity concentrations. The LSO scanner has the highest sensitivity of all the scanner designs investigated here, therefore leading to the highest peak NEC value but at a lower activity concentration than that of LaBr{sub 3}.

  13. A count-rate model for PET scanners using pixelated Anger-logic detectors with different scintillators.

    Science.gov (United States)

    Surti, S; Karp, J S

    2005-12-07

    A high count-rate simulation (HCRSim) model has been developed so that all results are derived from fundamental physics principles. Originally developed to study the behaviour of continuous sodium iodide (NaI(Tl)) detectors, this model is now applied to PET scanners based on pixelated Anger-logic detectors using lanthanum bromide (LaBr(3)), gadolinium orthosilicate (GSO) and lutetium orthosilicate (LSO) scintillators. This simulation has been used to study the effect on scanner deadtime and pulse pileup at high activity levels due to the scintillator stopping power (mu), decay time (tau) and energy resolution. Simulations were performed for a uniform 20 cm diameter x 70 cm long cylinder (NEMA NU2-2001 standard) in a whole-body scanner with an 85 cm ring diameter and a 25 cm axial field-of-view. Our results for these whole-body scanners demonstrate the potential of a pixelated Anger-logic detector and the relationship of its performance with the scanner NEC rate. Faster signal decay and short coincidence timing window lead to a reduction in deadtime and randoms fraction in the LaBr(3) and LSO scanners compared to GSO. The excellent energy resolution of LaBr(3) leads to the lowest scatter fraction for all scanners and helps compensate for reduced sensitivity compared to the GSO and LSO scanners, leading to the highest NEC values at high activity concentrations. The LSO scanner has the highest sensitivity of all the scanner designs investigated here, therefore leading to the highest peak NEC value but at a lower activity concentration than that of LaBr(3).

  14. Sensitivity booster for DOI-PET scanner by utilizing Compton scattering events between detector blocks

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Eiji, E-mail: rush@nirs.go.jp; Tashima, Hideaki; Yamaya, Taiga

    2014-11-01

    In a conventional PET scanner, coincidence events are measured with a limited energy window for detection of photoelectric events in order to reject Compton scatter events that occur in a patient, but Compton scatter events caused in detector crystals are also rejected. Scatter events within the patient causes scatter coincidences, but inter crystal scattering (ICS) events have useful information for determining an activity distribution. Some researchers have reported the feasibility of PET scanners based on a Compton camera for tracing ICS into the detector. However, these scanners require expensive semiconductor detectors for high-energy resolution. In the Anger-type block detector, single photons interacting with multiple detectors can be obtained for each interacting position and complete information can be gotten just as for photoelectric events in the single detector. ICS events in the single detector have been used to get coincidence, but single photons interacting with multiple detectors have not been used to get coincidence. In this work, we evaluated effect of sensitivity improvement using Compton kinetics in several types of DOI-PET scanners. The proposed method promises to improve the sensitivity using coincidence events of single photons interacting with multiple detectors, which are identified as the first interaction (FI). FI estimation accuracy can be improved to determine FI validity from the correlation between Compton scatter angles calculated on the coincidence line-of-response. We simulated an animal PET scanner consisting of 42 detectors. Each detector block consists of three types of scintillator crystals (LSO, GSO and GAGG). After the simulation, coincidence events are added as information for several depth-of-interaction (DOI) resolutions. From the simulation results, we concluded the proposed method promises to improve the sensitivity considerably when effective atomic number of a scintillator is low. Also, we showed that FI estimate

  15. A UGV-based laser scanner system for measuring tree geometric characteristics

    Science.gov (United States)

    Wang, Yonghui; Lan, Yubin; Zheng, Yongjun; Lee, Kevin; Cui, Suxia; Lian, Jian-ao

    2013-09-01

    This paper introduces a laser scanner based measurement system for measuring crop/tree geometric characteristics. The measurement system, which is mounted on a Unmanned Ground Vehicle (UGV), contains a SICK LMS511 PRO laser scanner, a GPS, and a computer. The LMS511 PRO scans objects within distance up to 80 meters with a scanning frequency of 25 up to 100Hz and with an angular resolution of 0.1667° up to 1°. With an Ethernet connection, this scanner can output the measured values in real time. The UGV is a WIFI based remotely controlled agricultural robotics system. During field tests, the laser scanner was mounted on the UGV vertically to scan crops or trees. The UGV moved along the row direction with certain average travel speed. The experimental results show that the UGV's travel speed significantly affects the measurement accuracy. A slower speed produces more accurate measuring results. With the developed measurement system, crop/tree canopy height, width, and volume can be accurately measured in a real-time manner. With a higher spatial resolution, the original data set may even provide useful information in predicting crop/tree growth and productivity. In summary, the UGV based measurement system developed in this research can measure the crop/tree geometric characteristics with good accuracy and will work as a step stone for our future UGV based intelligent agriculture system, which will include variable rate spray and crop/tree growth and productivity prediction through analyzing the measured results of the laser scanner system.

  16. [Exposure to static magnetic field and health hazards during the operation of magnetic resonance scanners].

    Science.gov (United States)

    Karpowicz, Jolanta; Gryz, Krzysztof; Politański, Piotr; Zmyślony, Marek

    2011-01-01

    Magnetic resonance imaging (MRI) scanners belong to the most modern imaging diagnostic devices, which involve workers' exposure to static magnetic fields (SMF) during the preparation and performance of MRI examinations. This paper presents the data on workers' exposure to SMF in the vicinity of MRI scanners and the analysis of SMF-related biological effects and health hazards to find out whether softening the legislative requirements concerning protection against SMF exposure of workers involved in MRI diagnostics is justified. Measurements in the vicinity of 1.5 T MRI magnets showed that exposure to SMF by various scanners depends on both SMF of magnets and scanners design, as well as on work organization. In a routine examination of one patient the radiographer is exposed to SMF exceeding 0.5 mT for app. 1.5-7 min, and up to 1.3 min to SMF exceeding 70 mT. In examinations of patients who need more attention, the duration of exposure may be significantly longer. The mean values (B mean) of exposure to SMF are 5.6-85 mT (mean 30 +/- 19 mT, N = 16). These data demonstrate that only well designed procedures, proper organization of workplace and awareness of workers how to attend the patients without being exposed to strong SMF allow for meeting the requirements of labor law concerning workers' exposure to SMF. The analysis of the available literature on biological effects of SMF has disclosed the lack of data on health effects of many years exposure of workers and the abundance of data demonstrating the biological activity of SMF. Therefore, a radical softening of legislative requirements concerning the exposure of workers' head or trunk is premature, and what is more, it is not indispensable for the development of MRI diagnostic. Such an action should be preceded by extensive international investigations on the health status of workers exposed to electromagnetic fields by MRI scanners.

  17. Application of intra-oral dental scanners in the digital workflow of implantology.

    Directory of Open Access Journals (Sweden)

    Wicher J van der Meer

    Full Text Available Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared.A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned with three intra-oral scanners: the CEREC (Sirona, the iTero (Cadent and the Lava COS (3M. In software the digital files were imported and the distance between the centres of the cylinders and the angulation between the cylinders was assessed. These values were compared to the measurements made on a high accuracy 3D scan of the master model.The distance errors were the smallest and most consistent for the Lava COS. The distance errors for the Cerec were the largest and least consistent. All the angulation errors were small.The Lava COS in combination with a high accuracy scanning protocol resulted in the smallest and most consistent errors of all three scanners tested when considering mean distance errors in full arch impressions both in absolute values and in consistency for both measured distances. For the mean angulation errors, the Lava COS had the smallest errors between cylinders 1-2 and the largest errors between cylinders 1-3, although the absolute difference with the smallest mean value (iTero was very small (0,0529°. An expected increase in distance and/or angular errors over the length of the arch due to an accumulation of registration errors of the patched 3D surfaces could be observed in this study design, but the effects were statistically not significant.For making impressions of implant cases for digital workflows, the most accurate scanner with the scanning protocol that will ensure the most accurate digital impression should be used. In our study model that was the Lava COS with the high accuracy scanning protocol.

  18. Accuracy of 3-dimensional curvilinear measurements on digital models with intraoral scanners.

    Science.gov (United States)

    Mack, Spencer; Bonilla, Tammy; English, Jeryl D; Cozad, Benjamin; Akyalcin, Sercan

    2017-09-01

    Our objectives were to evaluate and compare the digital dental models generated from 2 commercial intraoral scanners with manual measurements when performing 3-dimensional surface measurements along a curved line (curvilinear). Dry mandibles (n = 61) with intact dentition were used. The mandibles were digitized using 2 chair-side intraoral scanners: Cadent iTero (Align Technology, San Jose, Calif) and Lythos Digital Impression system (Ormco, Orange, Calif). Digitized 3-dimensional models were converted to individual stereolithography files and used with commercial software to obtain the curvilinear measurements. Manual measurements were carried out directly on the mandibular teeth. Measurements were made on different locations on the dental arch in various directions. One-sample t tests and linear regression analyses were performed. To further graphically examine the accuracy between the different methods, Bland-Altman plots were computed. The level of significance was set at P 0.05). Bland-Altman analysis showed no fixed bias of 1 approach vs the other, and random errors were detected in all comparisons. Although the mean biases of the digital models obtained by the iTero and Lythos scanners, when compared with direct caliper measurements, were low, the comparison of the 2 intraoral scanners yielded the lowest mean bias. No comparison displayed statistical significance for the t scores; this indicated the absence of proportional bias in these comparisons. The intraoral scanners tested in this study produced digital dental models that were comparatively accurate when performing direct surface measurements along a curved line in 3 dimensions. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  19. Sensitivity booster for DOI-PET scanner by utilizing Compton scattering events between detector blocks

    Science.gov (United States)

    Yoshida, Eiji; Tashima, Hideaki; Yamaya, Taiga

    2014-11-01

    In a conventional PET scanner, coincidence events are measured with a limited energy window for detection of photoelectric events in order to reject Compton scatter events that occur in a patient, but Compton scatter events caused in detector crystals are also rejected. Scatter events within the patient causes scatter coincidences, but inter crystal scattering (ICS) events have useful information for determining an activity distribution. Some researchers have reported the feasibility of PET scanners based on a Compton camera for tracing ICS into the detector. However, these scanners require expensive semiconductor detectors for high-energy resolution. In the Anger-type block detector, single photons interacting with multiple detectors can be obtained for each interacting position and complete information can be gotten just as for photoelectric events in the single detector. ICS events in the single detector have been used to get coincidence, but single photons interacting with multiple detectors have not been used to get coincidence. In this work, we evaluated effect of sensitivity improvement using Compton kinetics in several types of DOI-PET scanners. The proposed method promises to improve the sensitivity using coincidence events of single photons interacting with multiple detectors, which are identified as the first interaction (FI). FI estimation accuracy can be improved to determine FI validity from the correlation between Compton scatter angles calculated on the coincidence line-of-response. We simulated an animal PET scanner consisting of 42 detectors. Each detector block consists of three types of scintillator crystals (LSO, GSO and GAGG). After the simulation, coincidence events are added as information for several depth-of-interaction (DOI) resolutions. From the simulation results, we concluded the proposed method promises to improve the sensitivity considerably when effective atomic number of a scintillator is low. Also, we showed that FI estimate

  20. Modelling the Siemens SOMATOM Sensation 64 Multi-Slice CT (MSCT) Scanner

    Science.gov (United States)

    Amin, A. T. Mohd; Rahni, A. A. Abd

    2017-05-01

    Reconstructing large volumetric 3D images with minimal radiation dosage exposure with reduced scanning time has been one of the main objectives in the advancement of CT development. One of its advancement is the introduction of multi-slice arc detector geometry from a cone-beam source in third generation scanners. In solving this complex geometry, apart from the known vast computations in CT image reconstruction due to large CT images, iterative reconstruction methods are preferred compared to analytic methods due to its flexibility in image reconstruction. A scanner of interest that has this type of geometry is the Siemens SOMATOM Sensation 64 Multi-Slice CT (MSCT) Scanner, which has a total of 32 slices with 672 detector elements on each slice. In this paper, the scanner projection is modelled via the intersecting lengths between each ray (exhibited from the source to the detector elements) with the scanned image voxels, which are evaluated using the classical Siddon’s algorithm to generate the system matrix, H. This is a prerequisite to perform various iterative reconstruction methods, which involves solving the inverse problem arising from the linear equation: S = H· I; where S is the projections produced from the image, I. Due to the ‘cone-beam geometry’ along the z-axis, the effective field-of-view (FOV) with voxel dimensions (0.4×0.4×0.4) mm3 is 512×512×32 voxels. The scanner model is demonstrated by reconstructing an image from simulated projections using the analytic Feldkamp-Davis-Kress (FDK) method against basic iterative image reconstruction methods.

  1. Visualizing epithelial expression in vertical and horizontal planes with dual axes confocal endomicroscope using compact distal scanner.

    Science.gov (United States)

    Li, Gaoming; Li, Haijun; Duan, Xiyu; Zhou, Quan; Zhou, Juan; Wang, Thomas

    2017-02-23

    The epithelium is a thin layer of tissue that lines hollow organs, such as colon. Visualizing in vertical cross-sections with sub-cellular resolution is essential to understanding early disease mechanisms that progress naturally in the plane perpendicular to the tissue surface. The dual axes confocal architecture collects optical sections in tissue by directing light at an angle incident to the surface using separate illumination and collection beams to reduce effects of scattering, enhance dynamic range, and increase imaging depth. This configuration allows for images to be collected in the vertical as well as horizontal plane. We designed a fast, compact monolithic scanner based on the principle of parametric resonance. The mirrors were fabricated using microelectromechanical systems (MEMS) technology and were coated with aluminum to maximize near-infrared reflectivity. We achieved large axial displacements >400 m and wide lateral deflections >20o. The MEMS chip has a 3.2×2.9 mm2 form factor that allows for efficient packaging in the distal end of an endomicroscope. Imaging can be performed in either the vertical or horizontal plane with 430 m depth or 1×1 mm2 area, respectively, at 5 frames per second. We systemically administered a Cy5.5-labeled peptide that is specific for EGFR, and collected near-infrared fluorescence images ex vivo from pre-malignant mouse colonic epithelium to reveal the spatial distribution of this molecular target. Here, we demonstrate a novel scanning mechanism in a dual axes confocal endomicroscope that collects optical sections of near-infrared fluorescence in either vertical or horizontal planes to visualize molecular expression in the epithelium.

  2. Evaluation of Multiple-Sampling Function used with a Microtek flatbed scanner for Radiation Dosimetry Calibration of EBT2 Film

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Liyun [Department of Medical Imaging and Radiological Sciences, I-Shou University, Kaohsiung 82445, Taiwan (China); Ho, Sheng-Yow [Department of Nursing, Chang Jung Christian University, Tainan 71101, Taiwan (China); Department of Radiation Oncology, Chi Mei Medical Center, Liouying, Tainan 73657, Taiwan (China); Ding, Hueisch-Jy [Department of Medical Imaging and Radiological Sciences, I-Shou University, Kaohsiung 82445, Taiwan (China); Hwang, Ing-Ming [Department of Medical Imaging and Radiology, Shu Zen College of Medicine and Management, Kaohsiung 82144, Taiwan (China); Chen, Pang-Yu, E-mail: pangyuchen@yahoo.com.tw [Department of Radiation Oncology, Sinlau Christian Hospital, Tainan 70142, Taiwan (China); Lee, Tsair-Fwu, E-mail: tflee@kuas.edu.tw [Medical Physics and Informatics Laboratory, Department of Electronics Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan (China)

    2016-10-01

    The radiochromic EBT2 film is a widely used quality assurance device for radiation therapy. This study evaluated the film calibration performance of the multiple-sampling function, a function of the ScanWizard Pro scanning software provided by the manufacturer, when used with Microtek 9800XL plus (9800XL{sup +}) flatbed scanner. By using the PDD method, each one of the eight EBT2 films, four delivered by 290 monitor unit (MU) and four by 88 MU via 6-MV photon beams, was tightly sandwiched in a 30{sup 3}-cm{sup 3} water equivalent polystyrene phantom prior to irradiation. Before and after irradiation, all films were scanned using the Microtek 9800XL{sup +} scanner with five different modes of the multiple-sampling function, which could generate the image with the averaged result of multiple-sampling. The net optical densities (netOD) on the beam central axis of film were assigned to corresponding depth doses for calibration. For each sampling mode with either delivered MU, the depth-dose uncertainty of a single film from repeated scans and that of a single scan of the four films were analyzed. Finally, the calibration error and the combined calibration uncertainty between film determined depth-doses and delivered depth-doses were calculated and evaluated for each sampling mode. All standard deviations and the calibration error were demonstrated to be unrelated to the number of sampling lines. The calibration error of the 2-line and 16-line mode was within 3 cGy and better than that of the other modes. The combined uncertainty of the 2-line mode was the lowest, which was generally less than 6 cGy except for the delivered dose around 100 cGy. The evaluation described herein revealed that the EBT2 film calibrated with the 2-line mode has relatively lower error, scanning time and combined uncertianty. Therefore, it is recommended for routine EBT2 film calibration and verification of treatment plans.

  3. Scan-retrace scanner model with single-direction rotational motor%单向驱动往复式扫描反射镜模型

    Institute of Scientific and Technical Information of China (English)

    李海星; 姚园; 史磊

    2013-01-01

    提出了一种正反向1:2速比扫描模式的单向驱动往复式扫描反射镜模型,通过采用不完全齿轮传动机构和弹簧阻尼元件,在驱动元件不换向的前提下可实现反射镜正反转平稳切换。系统主要依靠弹簧的变形储能实现变速换向,降低了传统直驱式单面扫描反射镜系统换向过程中的驱动力矩输出要求。在正反向匀速扫描行程中,反射镜处于弹簧和驱动元件一对反作用力矩的共同作用下运动,有效消除了齿轮传动间隙,从原理上确保了系统传动精度。与传统直驱式单面扫描反射镜系统相比,该系统的驱动元件无需正反向切换,避免了传统系统因驱动元件频繁换向给电控设计带来的问题,而且降低了系统对驱动元件性能要求,在提高扫描频率方面具更具优势。该模型在轻小化、大行程、高精度光学扫描系统研制方面具有较大的开发应用潜力。%A scan-retrace optical scanner model without rotating direction change of the driving motor, was proposed. The scanner's fly-back angular velocity doubled its scan trip. By utilizing partially-cut gear transmission and spring-damper element, the system could realize stable scanner rotating direction change without the shift of driving motor current direction. Because the energy was mainly provided by the resilient member in the scanner rotating direction changing phase, it meant the driving motor was less demanding in the system than that in the traditional one. The scanner was subject to motor's driving torque and resilient member spring-back torque in scan and retrace trip. This design helped to eliminate gear clearance efficiently and could assure transmission accuracy of the system. Compared with traditional motor directly driving scanning system, rotational driving motor doesn't need current direction shift in this system, thus control system design is simplified, performance of driving motor is

  4. Expected innovations of optical lithography in the next 10 years

    Science.gov (United States)

    Owa, Soichi; Hirayanagi, Noriyuki

    2016-03-01

    In the past 10 years, immersion lithography has been the most effective high volume manufacturing method for the critical layers of semiconductor devices. Thinking of the next 10 years, we can expect continuous improvement on existing 300 mm wafer scanners with better accuracy and throughput to enhance the total output value per input cost. This value productivity, however, can be upgraded also by larger innovations which might happen in optical lithography. In this paper, we will discuss the possibilities and the impossibilities of potential innovation ideas of optical lithography, which are 450 mm wafer, optical maskless, multicolor lithography, and metamaterial.

  5. ScaRaB (Scanner for Radiation Budget). Final report; Das Strahlungsbilanzradiometer ScaRaB (Scanner for Radiation Budget). Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, J. [VEGA Informations-Technologien GmbH, Darmstadt (Germany); Hollmann, R.; Stuhlmann, R.; Raschke, E. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    2000-07-01

    A new radiometer for radiation budget measurements (scanner for radiation budget, (ScaRaB)) was developed within a German-French-Russian framework. In 1994/1995 the first instrument was launched on the METEOR satellite. The 2{sup nd} instrument was then launched in 1998 on the sunsynchronous Resurs satellite. The report describes the work done at GKSS within the ScaRaB project: calibration and validation. It gives an overview of related international and national research programmes and the future usefulness of the derived products to the scientific community. The work was funded by DLR under the contract number: FKZ 50-EE-9218. (orig.)

  6. DARPA/TTO program IR binary optics

    Science.gov (United States)

    Veldkamp, W. B.

    1984-06-01

    Binary grating optics consist of microfine rectangular (high-low) relief patterns on a dielectric or a metallic surface. By controlling the depth, width and periodicity of the binary pattern, the amplitude and the phase of an electromagnetic wave can be controlled to produce a variety of optical transfer functions. The lithographic tools for fabrication of binary optics are the ones developed for VLSI circuit fabrication. From a single lithographic mask, planar replica optics can be made in quantity. This technology has broad applicability for tactical missile systems as well as for space systems. In addition to making optics cheaper than by conventional means, binary optics allows the fabrication of unique devices that cannot be made conventionally. These include high-speed rotary scanners, multiplexers, filters, beam shapers and coherent laser adders. The goal of this program is the development of high quality planar optical components using VLSI circuit fabrication techniques. The main elements of the plan are: (1) the development of large aperture segmented and piezoelectrically active planar optical surfaces, (2) the development of raster scanning laser telescopes and extension to broadband applications, and (3) the application of diffractive optics technology to the coherent addition of beams from modular laser systems. This report covers progress in the setup of a reactive ion-beam etching laboratory, and the feasibility demonstrations of the coherent beam addition concept with gas lasers.

  7. Performance evaluation of a high-resolution brain PET scanner using four-layer MPPC DOI detectors

    Science.gov (United States)

    Watanabe, Mitsuo; Saito, Akinori; Isobe, Takashi; Ote, Kibo; Yamada, Ryoko; Moriya, Takahiro; Omura, Tomohide

    2017-09-01

    A high-resolution positron emission tomography (PET) scanner, dedicated to brain studies, was developed and its performance was evaluated. A four-layer depth of interaction detector was designed containing five detector units axially lined up per layer board. Each of the detector units consists of a finely segmented (1.2 mm) LYSO scintillator array and an 8  ×  8 array of multi-pixel photon counters. Each detector layer has independent front-end and signal processing circuits, and the four detector layers are assembled as a detector module. The new scanner was designed to form a detector ring of 430 mm diameter with 32 detector modules and 168 detector rings with a 1.2 mm pitch. The total crystal number is 655 360. The transaxial and axial field of views (FOVs) are 330 mm in diameter and 201.6 mm, respectively, which are sufficient to measure a whole human brain. The single-event data generated at each detector module were transferred to the data acquisition servers through optical fiber cables. The single-event data from all detector modules were merged and processed to create coincidence event data in on-the-fly software in the data acquisition servers. For image reconstruction, the high-resolution mode (HR-mode) used a 1.2 mm2 crystal segment size and the high-speed mode (HS-mode) used a 4.8 mm2 size by collecting 16 crystal segments of 1.2 mm each to reduce the computational cost. The performance of the brain PET scanner was evaluated. For the intrinsic spatial resolution of the detector module, coincidence response functions of the detector module pair, which faced each other at various angles, were measured by scanning a 0.25 mm diameter 22Na point source. The intrinsic resolutions were obtained with 1.08 mm full width at half-maximum (FWHM) and 1.25 mm FWHM on average at 0 and 22.5 degrees in the first layer pair, respectively. The system spatial resolutions were less than 1.0 mm FWHM throughout the whole FOV, using a

  8. Performance evaluation of a high-resolution brain PET scanner using four-layer MPPC DOI detectors.

    Science.gov (United States)

    Watanabe, Mitsuo; Saito, Akinori; Isobe, Takashi; Ote, Kibo; Yamada, Ryoko; Moriya, Takahiro; Omura, Tomohide

    2017-08-18

    A high-resolution positron emission tomography (PET) scanner, dedicated to brain studies, was developed and its performance was evaluated. A four-layer depth of interaction detector was designed containing five detector units axially lined up per layer board. Each of the detector units consists of a finely segmented (1.2 mm) LYSO scintillator array and an 8  ×  8 array of multi-pixel photon counters. Each detector layer has independent front-end and signal processing circuits, and the four detector layers are assembled as a detector module. The new scanner was designed to form a detector ring of 430 mm diameter with 32 detector modules and 168 detector rings with a 1.2 mm pitch. The total crystal number is 655 360. The transaxial and axial field of views (FOVs) are 330 mm in diameter and 201.6 mm, respectively, which are sufficient to measure a whole human brain. The single-event data generated at each detector module were transferred to the data acquisition servers through optical fiber cables. The single-event data from all detector modules were merged and processed to create coincidence event data in on-the-fly software in the data acquisition servers. For image reconstruction, the high-resolution mode (HR-mode) used a 1.2 mm(2) crystal segment size and the high-speed mode (HS-mode) used a 4.8 mm(2) size by collecting 16 crystal segments of 1.2 mm each to reduce the computational cost. The performance of the brain PET scanner was evaluated. For the intrinsic spatial resolution of the detector module, coincidence response functions of the detector module pair, which faced each other at various angles, were measured by scanning a 0.25 mm diameter (22)Na point source. The intrinsic resolutions were obtained with 1.08 mm full width at half-maximum (FWHM) and 1.25 mm FWHM on average at 0 and 22.5 degrees in the first layer pair, respectively. The system spatial resolutions were less than 1.0 mm FWHM throughout the whole FOV, using

  9. Exposure to static and time-varying magnetic fields from working in the static magnetic stray fields of MRI scanners : A comprehensive survey in the Netherlands

    NARCIS (Netherlands)

    Schaap, Kristel; Christopher-De Vries, Yvette; Crozier, Stuart; Vocht, Frank De; Kromhout, Hans

    2014-01-01

    Clinical and research staff who work around magnetic resonance imaging (MRI) scanners are exposed to the static magnetic stray fields of these scanners. Although the past decade has seen strong developments in the assessment of occupational exposure to electromagnetic fields from MRI scanners, there

  10. Exposure to static and time-varying magnetic fields from working in the static magnetic stray fields of MRI scanners : A comprehensive survey in the Netherlands

    NARCIS (Netherlands)

    Schaap, Kristel; Christopher-De Vries, Yvette; Crozier, Stuart; Vocht, Frank De; Kromhout, Hans

    2014-01-01

    Clinical and research staff who work around magnetic resonance imaging (MRI) scanners are exposed to the static magnetic stray fields of these scanners. Although the past decade has seen strong developments in the assessment of occupational exposure to electromagnetic fields from MRI scanners, there

  11. Do we really need to thank the Beatles for the financing of the development of the computed tomography scanner?

    Science.gov (United States)

    Maizlin, Zeev V; Vos, Patrick M

    2012-01-01

    It is commonly believed that the revenues from the selling of the Beatles' records by Electric and Musical Industries (EMI) allowed the company to develop the computed tomography (CT) scanner. Some went to define this as the Beatles' gift to medicine. However, significant controversies and discrepancies arise from analysis of this statement, making its correctness doubtful. The details of financing required for the CT development and the part of EMI in financial input have never been publicly announced. This work analyzes the financial contributions to the CT development and investigates if the revenues received from the sales of the Beatles' records were used for the creation of the CT scanner. Timeline of the development of the EMI CT scanner and the financial inputs of EMI and British Department of Health and Social Security (DHSS) were assessed. Without salary expenses to Godfrey Hounsfield and his team, the development of the CT scanner cost EMI approximately £100,000. The British DHSS's expenses were £606,000. Hence, the financial contribution of DHSS into the development of the CT scanner was significantly bigger than that of EMI. Accordingly, British tax payers and officials of British DHSS are to be thanked for the CT scanner. The Beatles' input into the world's culture is valuable and does not require decoration by nonexistent connection to the development of CT. A positive aspect to this misconception is that it keeps in public memory the name of the company that developed the CT scanner.

  12. Time-invariant component-based normalization for a simultaneous PET-MR scanner.

    Science.gov (United States)

    Belzunce, M A; Reader, A J

    2016-05-07

    Component-based normalization is a method used to compensate for the sensitivity of each of the lines of response acquired in positron emission tomography. This method consists of modelling the sensitivity of each line of response as a product of multiple factors, which can be classified as time-invariant, time-variant and acquisition-dependent components. Typical time-variant factors are the intrinsic crystal efficiencies, which are needed to be updated by a regular normalization scan. Failure to do so would in principle generate artifacts in the reconstructed images due to the use of out of date time-variant factors. For this reason, an assessment of the variability and the impact of the crystal efficiencies in the reconstructed images is important to determine the frequency needed for the normalization scans, as well as to estimate the error obtained when an inappropriate normalization is used. Furthermore, if the fluctuations of these components are low enough, they could be neglected and nearly artifact-free reconstructions become achievable without performing a regular normalization scan. In this work, we analyse the impact of the time-variant factors in the component-based normalization used in the Biograph mMR scanner, but the work is applicable to other PET scanners. These factors are the intrinsic crystal efficiencies and the axial factors. For the latter, we propose a new method to obtain fixed axial factors that was validated with simulated data. Regarding the crystal efficiencies, we assessed their fluctuations during a period of 230 d and we found that they had good stability and low dispersion. We studied the impact of not including the intrinsic crystal efficiencies in the normalization when reconstructing simulated and real data. Based on this assessment and using the fixed axial factors, we propose the use of a time-invariant normalization that is able to achieve comparable results to the standard, daily updated, normalization factors used in this

  13. SU-E-J-35: Clinical Performance Evaluation of a Phase II Proton CT Scanner

    Energy Technology Data Exchange (ETDEWEB)

    Mandapaka, A; Ghebremedhin, A; Farley, D; Giacometti, V; Vence, N; Bashkirov, V; Patyal, B; Schulte, R [Loma Linda UniversityMedical Center, Loma Linda, CA (United States); Plautz, T; Zatserklyaniy, A; Johnson, R; Sadrozinski, H [University of California Santa Cruz, Santa Cruz, CA (United States)

    2014-06-01

    Purpose: To develop the methodology to evaluate the clinical performance of a Phase II Proton CT scanner Methods: Range errors on the order of 3%-5% constitute a major uncertainty in current charged particle treatment planning based on Hounsfield Unit (HU)-relative stopping power (RSP) calibration curves. Within our proton CT collaboration, we previously developed and built a Phase I proton CT scanner that provided a sensitive area of 9 cm (axial) × 18 cm (in-plane). This scanner served to get initial experience with this new treatment planning tool and to incorporate lessons learned into the next generation design. A Phase II scanner was recently completed and is now undergoing initial performance testing. It will increase the proton acquisition rate and provide a larger detection area of 9 cm x 36 cm. We are now designing a comprehensive evaluation program to test the image quality, imaging dose, and range uncertainty associated with this scanner. The testing will be performed along the lines of AAPM TG 66. Results: In our discussion of the evaluation protocol we identified the following priorities. The image quality of proton CT images, in particular spatial resolution and low-density contrast discrimination, will be evaluated with the Catphan600 phantom. Initial testing showed that the Catphan uniformity phantom did not provide sufficient uniformity; it was thus replaced by a cylindrical water phantom. The imaging dose will be tested with a Catphan dose module, and compared to a typical cone beam CT dose for comparable image quality. Lastly, we developed a dedicated dosimetry range phantom based on the CIRS pediatric head phantom HN715. Conclusion: A formal evaluation of proton CT as a new tool for proton treatment planning is an important task. The availability of the new Phase II proton CT scanner will allow us to perform this task. This research is supported by the National Institute of Biomedical Imaging and Bioengineering of the NIH under award number R01

  14. Range 7 Scanner Integration with PaR Robot Scanning System

    Science.gov (United States)

    Schuler, Jason; Burns, Bradley; Carlson, Jeffrey; Minich, Mark

    2011-01-01

    An interface bracket and coordinate transformation matrices were designed to allow the Range 7 scanner to be mounted on the PaR Robot detector arm for scanning the heat shield or other object placed in the test cell. A process was designed for using Rapid Form XOR to stitch data from multiple scans together to provide an accurate 3D model of the object scanned. An accurate model was required for the design and verification of an existing heat shield. The large physical size and complex shape of the heat shield does not allow for direct measurement of certain features in relation to other features. Any imaging devices capable of imaging the entire heat shield in its entirety suffers a reduced resolution and cannot image sections that are blocked from view. Prior methods involved tools such as commercial measurement arms, taking images with cameras, then performing manual measurements. These prior methods were tedious and could not provide a 3D model of the object being scanned, and were typically limited to a few tens of measurement points at prominent locations. Integration of the scanner with the robot allows for large complex objects to be scanned at high resolution, and for 3D Computer Aided Design (CAD) models to be generated for verification of items to the original design, and to generate models of previously undocumented items. The main components are the mounting bracket for the scanner to the robot and the coordinate transformation matrices used for stitching the scanner data into a 3D model. The steps involve mounting the interface bracket to the robot's detector arm, mounting the scanner to the bracket, and then scanning sections of the object and recording the location of the tool tip (in this case the center of the scanner's focal point). A novel feature is the ability to stitch images together by coordinates instead of requiring each scan data set to have overlapping identifiable features. This setup allows models of complex objects to be developed

  15. Time-invariant component-based normalization for a simultaneous PET-MR scanner

    Science.gov (United States)

    Belzunce, M. A.; Reader, A. J.

    2016-05-01

    Component-based normalization is a method used to compensate for the sensitivity of each of the lines of response acquired in positron emission tomography. This method consists of modelling the sensitivity of each line of response as a product of multiple factors, which can be classified as time-invariant, time-variant and acquisition-dependent components. Typical time-variant factors are the intrinsic crystal efficiencies, which are needed to be updated by a regular normalization scan. Failure to do so would in principle generate artifacts in the reconstructed images due to the use of out of date time-variant factors. For this reason, an assessment of the variability and the impact of the crystal efficiencies in the reconstructed images is important to determine the frequency needed for the normalization scans, as well as to estimate the error obtained when an inappropriate normalization is used. Furthermore, if the fluctuations of these components are low enough, they could be neglected and nearly artifact-free reconstructions become achievable without performing a regular normalization scan. In this work, we analyse the impact of the time-variant factors in the component-based normalization used in the Biograph mMR scanner, but the work is applicable to other PET scanners. These factors are the intrinsic crystal efficiencies and the axial factors. For the latter, we propose a new method to obtain fixed axial factors that was validated with simulated data. Regarding the crystal efficiencies, we assessed their fluctuations during a period of 230 d and we found that they had good stability and low dispersion. We studied the impact of not including the intrinsic crystal efficiencies in the normalization when reconstructing simulated and real data. Based on this assessment and using the fixed axial factors, we propose the use of a time-invariant normalization that is able to achieve comparable results to the standard, daily updated, normalization factors used in this

  16. Optical processing

    Science.gov (United States)

    Gustafson, S. C.

    1985-12-01

    The technical contributions were as follows: (1) Optical parallel 2-D neighborhood processor and optical processor assessment technique; (2) High accuracy with moderately accurate components and optical fredkin gate architectures; (3) Integrated optical threshold computing, pipelined polynomial processor, and all optical analog/digital converter; (4) Adaptive optical associative memory model with attention; (5) Effectiveness of parallelism and connectivity in optical computers; (6) Optical systolic array processing using an integrated acoustooptic module; (7) Optical threshold elements and networks, holographic threshold processors, adaptive matched spatial filtering, and coherence theory in optical computing; (8) Time-varying optical processing for sub-pixel targets, optical Kalman filtering, and adaptive matched filtering; (9) Optical degrees of freedom, ultra short optical pulses, number representations, content-addressable-memory processors, and integrated optical Givens rotation devices; (10) Optical J-K flip flop analysis and interfacing for optical computers; (11) Matrix multiplication algorithms and limits of incoherent optical computers; (12) Architecture for machine vision with sensor fusion, pattern recognition functions, and neural net implementations; (13) Optical computing algorithms, architectures, and components; and (14) Dynamic optical interconnections, advantages and architectures.

  17. Miniature design of galvanometer scanner circuit%小型化振镜扫描器电路设计

    Institute of Scientific and Technical Information of China (English)

    李鹏; 范璐璐

    2009-01-01

    In this paper,first of all,we analyze galvanometer scanner construction, second,we set up the model of galvanometer scanner servo theory,the end,we design the galvanometer scanner servo circuit.%分析了振镜扫描器的基本组成,建立了振镜扫描器伺服系统的理论模型,最后根据上述理论,设计了小型化振镜扫描器伺服驱动电路.

  18. Feature Based Modeling and Mapping of Tree Trunks and Natural Terrain Using 3D Laser Scanner Measurement System

    OpenAIRE

    Hyyti, Heikki; Visala, Arto

    2013-01-01

    This paper presents a novel approach to measure tree trunks and to model the ground using a 3D laser scanner. The 3D scanner, self-build using two 2D Sick scanners on a rotating base, measures each scan line approximately at 45° angle towards the ground and the trees. Single scan lines are segmented to find ground and tree returns. 3D point clouds from the surrounding forest are recorded while the measuring vehicle is moving. Sequential scan lines are joined together as the pose changes are r...

  19. WindScanner.dk - a new Remote Sensing based Research Infrastructure for on- and offshore Wind Energy Research

    DEFF Research Database (Denmark)

    Mikkelsen, Torben

    Recent measurement achievements obtained with new 3D remote sensing based WindScanners will be presented. Our new WindScanner research infrastructure (www.windscanner.dk) development based on remote sensing wind lidars will be presented and first results shown. Wind velocity 3D vector measurements...... and 3-dimensional wind vector scan measurements obtained during various WindScanner boundary-layer field campaigns. A special designed `2D upwind rotor plane scanning SpinnerLidar', mounted in the rotating spinner, and able to provide the wind turbine control systems with detailed upwind feed...

  20. Comparison of rankings for lean meat based on results from a CT scanner and a video image analysis system.

    Science.gov (United States)

    Jay, N P; van de Ven, R J; Hopkins, D L

    2014-10-01

    Coopworth cross lambs born over three years were examined in this study. Differences between two machines; a computer tomography (CT) scanner and a VIAScan® system for the estimation of carcase lean weight in lamb carcases was examined. The CT scanner provided a significantly higher estimate of carcase lean. The rank correlation (0.84) between the CT scanner and the VIAScan® system for the prediction of carcase lean was significant, but there was a different ranking for carcase lean depending on which machine was used. This has important ramifications for the use of VIAScan® data in the New Zealand Sheep Improvement Ltd genetic programme.