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Sample records for limb scanning based

  1. Atmospheric Waves in MGS TES Limb-Scan Temperatures

    NASA Astrophysics Data System (ADS)

    Banfield, D. J.; Conrath, B. J.; Kaelberer, M. S.; Smith, M. D.

    2014-12-01

    We have quantified the expression of the lowest zonal wavenumber forced and traveling waves evident in the MGS TES Limb-scan temperature retrievals. The results were found to be broadly consistent with the vertically limited and vertically smoothed (although better spatially and temporally resolved) results from the more numerous MGS TES nadir temperature retrievals (e.g., Wilson et al., 2002, Banfield et al., 2003, Banfield et al. 2004). The MGS TES Limb-scan retrievals were used to compute a measure of the Diurnal Kelvin Waves (DK1 And DK2). The structures revealed are consistent with theory, and indicative of the importance of these wave modes at aerobraking altitudes (e.g., Wilson 2000, Forbes & Hagan, 2000, Wilson, 2002). The stationary wave structures revealed in the limb retrievals show the winter polar waves in both hemispheres continue to have their maximum amplitude aligned along the polar vortices, even for altitudes above 4 scale heights. The phase structures in and above the stationary waves revealed by the limb retrievals are consistent with the nadir results and the heat fluxes computed in those analyses (Banfield et al., 2003). The winter polar vortex zonal wavenumber 1 traveling waves continue along the edge of the polar vortex, reaching to 6 or more scale heights altitude in the northern winter and extending between 60N and the north pole. The peak amplitudes for these zonal wavenumber 1 traveling waves were found to lie at about 4 scale heights altitude. The limb retrievals revealed more clear evidence of a northern fall equinoctial global traveling wave mode having expression not only in the mid-latitudes in both hemispheres, but also out of phase above the tropics at altitudes above 4 scale heights. Zonal wavenumber 2 & 3 traveling waves could not be reliably retrieved from the limb retrievals.

  2. Design and Implementation of a Mechanical Control System for the Scanning Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Bowden, William

    2011-01-01

    The Scanning Microwave Limb Sounder (SMLS) will use technological improvements in low noise mixers to provide precise data on the Earth's atmospheric composition with high spatial resolution. This project focuses on the design and implementation of a real time control system needed for airborne engineering tests of the SMLS. The system must coordinate the actuation of optical components using four motors with encoder readback, while collecting synchronized telemetric data from a GPS receiver and 3-axis gyrometric system. A graphical user interface for testing the control system was also designed using Python. Although the system could have been implemented with a FPGA-based setup, we chose to use a low cost processor development kit manufactured by XMOS. The XMOS architecture allows parallel execution of multiple tasks on separate threads-making it ideal for this application and is easily programmed using XC (a subset of C). The necessary communication interfaces were implemented in software, including Ethernet, with significant cost and time reduction compared to an FPGA-based approach. For these reasons, the XMOS technology is an attractive, cost effective, alternative to FPGA-based technologies for this design and similar rapid prototyping projects.

  3. System Design and Technology Development for an Azimuth Scanning Microwave Limb Sounder

    NASA Astrophysics Data System (ADS)

    Stek, P. C.; Chattopadhyay, G.; Cofield, R.; Jarnot, R.; Kawamura, J.; Lee, K.; Livesey, N.; Ward, J.

    2007-12-01

    The NRC's Earth Science and Applications from Space decadal survey calls for a mission (GACM) to study global atmospheric composition, "with sufficient vertical resolution to detect the presence, transport, and chemical transformation of atmospheric layers from the surface to the lower stratosphere." Microwave limb sounding is particularly well suited for providing this information for the upper troposphere and above. The Microwave Limb Sounders on Aura and UARS have provided global measurements that have: quantified the evolution of the ozone layer; characterized the water vapor and cloud ice feedback mechanisms affecting climate change; documented the long range transport of pollution through tracers like CO; and improved the accuracy of global circulation models used for weather and climate forecasts. The Scanning Microwave Limb Sounder (SMLS) concept builds on the success of these instruments by adding an azimuth scan and increasing the antenna height to greatly improve horizontal and vertical resolution. The measurement swath is wide enough to provide, depending on orbit inclination, six or more daily measurements over midlatitudes. SMLS will incorporate a novel antenna design that enables rapid horizontal scanning, 4 Kelvin receiver front ends, advanced digital receiver back ends, and several lessons learned from previous missions. We will discuss the instrument design, technology development and readiness, and our approach to on-orbit calibration. We will also discuss plans and goals for a demonstration instrument that takes advantage of technologies developed through ESTO and other NASA and non-NASA programs. cameo.php

  4. Modification and Development of a Control Mechanism for the Scanning Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Greene, Zach

    2011-01-01

    The scanning microwave limb sounder (SMLS) is the latest instrument to probe the Earth's atmosphere to come out of the Microwave Limb Sounder (MLS) team. Once deployed to the upper stratosphere, it will use microwave detection to measure geo-atmospheric variables such as temperature, pressure, and chemical composition. In addition to previous missions that used vertical limb scans to observe altitudinal variations, the SMLS will rotate laterally allowing it to establish two-dimensional variable dependencies with a single run. A program was originated by a previous intern that will automatically control the movement of the two rotational axes along with a switching mirror and chopper once the instrument is in flight. However, it lacked the code essential to control system's ability to function fully and reliably. By modifying and rewriting parts of the code I sought to have a finished ready-for-flight control system that would be easy to navigate. Three of the major alterations I made including instituting a gyroscope, implementing a restart button, and instigating the automatic creation of a file log with each run to record the position and orientation of the SMLS.

  5. Thermal Stability of a 4 Meter Primary Reflector for the Scanning Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Cofield, Richard; Kasl, Eldon P.

    2010-01-01

    We describe the fabrication and thermal-stability analysis and test of a composite demonstration model of the Scanning Microwave Limb Sounder (SMLS) primary reflector, having full 4m height and 1/3 the width planned for flight. SMLS is a space-borne heterodyne radiometer which will measure pressure, temperature and atmospheric constituents from thermal emission between 180 and 660 GHz. Current MLS instruments in low Earth orbit scan pencil-beam antennas (sized to resolve about one scale height) vertically over the atmospheric limb. SMLS, planned for the Global Atmospheric Composition Mission of the NRC Decadal Survey, adds azimuthal scanning for better horizontal and temporal resolution and coverage than typical orbit spacing provides. SMLS combines the wide scan range of the parabolic torus with unblocked offset Cassegrain optics. The resulting system is diffraction-limited in the vertical plane but highly astigmatic in the horizontal, having a beam aspect ratio [tilde operator]1:20. Symmetry about the nadir axis ensures that beam shape is nearly invariant over +/-65(white bullet) azimuth. The a feeds a low-noise SIS receiver whose FOV is swept over the reflector system by a small scanning mirror. Using finiteelement models of antenna reflectors and structure, we evaluate thermal deformations and the resulting optical performance for 4 orbital environments and isothermal soak. We compare deformations with photogrammetric measurements made during wide-range (ambient+[-97,+75](white bullet) C) thermal soak tests of the primary in a chamber. This range exceeds predicted orbital soak ranges by large factors, implying in-orbit thermal stability of 0.21(mu)m rms/(white bullet)C, which meets SMLS requirements.

  6. Thermal Stability of a 4 Meter Primary Reflector for the Scanning Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Cofield, Richard E.; Kasl, Eldon P.

    2011-01-01

    The Scanning Microwave Limb Sounder (SMLS) is a space-borne heterodyne radiometer which will measure pressure, temperature and atmospheric constituents from thermal emission in [180,680] GHz. SMLS, planned for the NRC Decadal Survey's Global Atmospheric Composition Mission, uses a novel toric Cassegrain antenna to perform both elevation and azimuth scanning. This provides better horizontal and temporal resolution and coverage than were possible with elevation-only scanning in the two previous MLS satellite instruments. SMLS is diffraction-limited in the vertical plane but highly astigmatic in the horizontal (beam aspect ratio approx. 1:20). Nadir symmetry ensures that beam shape is nearly invariant over plus or minus 65 deg azimuth. A low-noise receiver FOV is swept over the reflector system by a small azimuth-scanning mirror. We describe the fabrication and thermal-stability test of a composite demonstration primary reflector, having full 4m height and 1/3 the width planned for flight. Using finite-element models of reflectors and structure, we evaluate thermal deformations and optical performance for 4 orbital environments and isothermal soak. We compare deformations with photogrammetric measurements made during soak tests in a chamber. The test temperature range exceeds predicted orbital ranges by large factors, implying in-orbit thermal stability of 0.21 micron rms (root mean square)/C, which meets SMLS requirements.

  7. Study of a Vuilleumier cycle cryogenic refrigerator for detector cooling on the limb scanning infrared radiometer

    NASA Technical Reports Server (NTRS)

    Russo, S. C.

    1976-01-01

    A program to detect and monitor the presence of trace constituents in the earth's atmosphere by using the Limb Scanning Infrared Radiometer (LSIR) is reported. The LSIR, which makes radiometric measurements of the earth's limb radiance profile from a space platform, contains a detector assembly that must be cooled to a temperature of 65 + or - 2 K. The feasibility of cooling the NASA-type detector package with Vuilleumier (VM) cryogenic refrigerator was investigated to develop a preliminary conceptual design of a VM refrigerator that is compatible with a flight-type LSIR instrument. The scope of the LSIR program consists of analytical and design work to establish the size, weight, power consumption, interface requirements, and other important characteristics of a cryogenic cooler that would meet the requirements of the LSIR. The cryogenic cooling requirements under the conditions that NASA specified were defined. Following this, a parametric performance analysis was performed to define the interrelationships between refrigeration characteristics and mission requirements. This effort led to the selection of an optimum refrigerator design for the LSIR mission.

  8. A Deployable 4 Meter 180 to 680 GHz Antenna for the Scanning Microwave Limb Sounder

    NASA Technical Reports Server (NTRS)

    Cofield, Richard E.; Cohen, Eri J.; Agnes, Gregory S.; Stek, Paul C.; Livesey, Nathaniel J.; Read, William G.; Thomson, Mark W.; Kasl, Eldon

    2011-01-01

    The Scanning Microwave Limb Sounder (SMLS) is a space-borne heterodyne radiometer which will measure pressure, temperature and atmospheric constituents from thermal emission between 180 and 680 GHz. SMLS, planned for the Global Atmospheric Composition Mission of the NRC Decadal Survey, uses a novel toric Cassegrain antenna to perform both elevation and azimuth scanning. These provide better horizontal and temporal resolution and coverage than were possible with elevation-only scanning at typical Low-Earth orbit spacing in the two previous MLS satellite instruments. Development of the SMLS antenna was the focus of a 2006 Small Business Innovative Research (SBIR) program whose phase II culminated in the fabrication and thermal stability testing of a composite demonstration model of the SMLS primary reflector. This reflector has the full 4m height and 1/3 the width planned for flight. An Instrument Incubator Program (IIP) titled "A deployable 4 Meter 180 to 680 GHz antenna for the Scanning Microwave Limb Sounder" continues development of the SMLS antenna with the study of 5 topics: 1) detailed mathematical modeling of the antenna patterns from which we simulate geophysical parameter retrievals in order to establish FOV performance requirements; 2) thorough correlation of finite element model predictions with measurements made on the SBIR reflector. We will again measure deformations of this reflector, under more flight-like thermal gradients, using higher precision metrology techniques available in a new large-aperture facility at JPL; 3) fabrication of a full-width primary reflector whose asbuilt surface figure will better meet the figure requirements of SMLS than did the SBIR reflector; 4) integration of the primary with other reflectors, and with residual front ends built in a 2007 IIP, in a breadboard antenna; and finally 5) RF testing of the breadboard on a Near Field Range at JPL. We report on significant progress in 3 areas of the current IIP: development of

  9. Constraints on JN2O5 from balloon-borne limb scanning measurements of NO2 in the tropics

    NASA Astrophysics Data System (ADS)

    Kritten, L. K.; Dorf, M.; Butz, A.; Kreycy, S.; Prados-Roman, C.; Pfeilsticker, K.

    2009-12-01

    A recent study [Ravishankara et al., 2009] revealed the growing importance of N2O and the related partitioning of NOx/NOy for stratospheric ozone in the coming decades. Evidently, the related NOx/NOy photochemistry is most important in the tropical mid-stratosphere where most ozone is formed. We report on measurements of the diurnal variation of NO2 in the tropical upper troposphere and lower stratosphere, observed during stratospheric balloon flights at north eastern Brazil (5°S, 43°W) in June 2005. The diurnal variation of stratospheric NO2 profiles is inferred from limb scanning balloon-borne spectroscopic measurements in the UV/visible range. Furthermore, photochemical modelling indicates that the observed increase of stratospheric NO2 in the tropical stratosphere is primarily due to the photolysis of N2O5 at daytime. Accordingly our NO2 data is interpreted with respect to the photolysis rate of N2O5 (JN2O5). Together with calculated actinic fluxes, conclusions on the magnitude of the N2O5 absorption cross-section and its uncertainty can be drawn as e.g. compiled in the JPL-2006 data base. Diurnal variation of NO2 measured by limb scattered skylight observations on June 30, 2005.

  10. Baffle design for earth radiation rejection in the Cryogenic Limb-Scanning Interferometer/Radiometer

    NASA Astrophysics Data System (ADS)

    Bremer, J. C.

    1980-01-01

    The Cryogenic Limb-Scanning Interferometer/Radiometer (CLIR) is being developed to observe infrared emissions of the earth's upper atmosphere from space. The earth's surface is an extended source of intense background radiation with a small angular separation from the desired scene. The CLIR employs an off-axis Gregorian Telescope whose primary mirror and baffles are cooled by an open-cycle cryogen system. A system of specular annular baffles has been developed to minimize both stray light problems and cryogen consumption by retro-mapping the aperture into itself. Each off-axis ray which enters the aperture and strikes the specular baffle surface is reflected so that it passes out of the aperture and is not absorbed on a cryogenic surface. The specular baffle which lies closest to the aperture is an ellipsoid whose foci trace out the circular aperture on revolution about the axis. Its theoretical 'ray trace' efficiency is 100 percent. A subsequent baffle has an elliptical cross section whose near focus traces out the central hole in the ellipsoidal baffle and whose far focus traces out the aperture. Its theoretical efficiency is about 90 percent. These baffles reduce the earth radiation heat load on the cryogenic cooler by an order of magnitude, changing it from the dominant cause of cryogen consumption to a relatively small effect. An aperture shield is also desirable to reduce cryogen consumption, stray light, and contamination.

  11. Baffle Design For Earth Radiation Rejection In The Cryogenic Limb-Scanning Interferometer/Radiometer

    NASA Astrophysics Data System (ADS)

    Bremer, James C.

    1983-02-01

    The function of the cryogenic limb-scanning interferometer/radiometer (CLIR) is to observe infrared emissions of the earth's upper atmosphere from space. The earth's surface is an extended source of intense background radiation with a small angular separation from the desired scene. The CLIR employs an off-axis Gregorian telescope whose primary mirror and baffles are cooled by an open-cycle cryogenic system. A system of specular annular baffles has been designed to minimize both stray light problems and cryogen consumption by retromapping the aperture into itself. Off-axis rays which enter the aperture and strike the baffles are reflected so that they pass out of the aperture again and are not absorbed on cryogenic surfaces. The edge ray principle is used to configure the specular baffle surfaces. The baffle which lies closest to the aperture is an ellipsoid whose foci trace out the circular aperture on revolution about the axis. Its theoretical "ray trace" efficiency is 100 percent. A subsequent baffle has an elliptical cross section whose near focus traces out the central hole in the ellipsoidal baffle and whose far focus traces out the aperture. Its theoretical efficiency is about 90 percent. These baffles reduce the earth radiation heat load on the cryogenic cooler by an order of magnitude, changing it from the dominant cause of cryogen consumption to a relatively small effect. An aperture shield is also desirable to reduce cryogen consumption, stray light, and contamination.

  12. Observations of BrO Using Limb Scanning DOAS During the 2013 NOMADSS Campaign

    NASA Astrophysics Data System (ADS)

    Festa, J.; Stutz, J.; Tsai, J. Y.; Spolaor, M.; Zhou, X.; Ye, C.; Jaffe, D. A.; Gratz, L.; Ambrose, J. L., II; Jaegle, L.; Shah, V.; Selin, N. E.; Song, S.

    2014-12-01

    Bromine monoxide (BrO) is an important atmospheric constituent, participating in the destruction of tropospheric and stratospheric ozone and the oxidation of gaseous elemental Hg (GEM) to form reactive Hg (RM). During the Nitrogen, Oxidants, Mercury and Aerosol Distributions, Sources and Sinks (NOMADSS) campaign in the summer of 2013, our group operated a limb-scanning Differential Optical Absorption Spectroscopy (DOAS) instrument onboard the NSF/NCAR C-130 aircraft with the goal of quantifying BrO, formaldehyde (HCHO), nitrogen dioxide (NO2), and other trace gases. Here we present observations of Differential Slant Column Densities (DSCD) obtained in the limb derived using the DOAS analysis technique. A radiative transfer model (McArtim [Deutschmann et al., 2011]), constrained by in-situ measurement on the aircraft or from published literature, was utilized to simulate the DSCDs and to derive BrO mixing ratios at flight altitude. BrO mixing ratios were typically below our 2σ detection limit (ranging from 0.5 - 1 ppt) with the exception of a high altitude (~7km asl) portion of a flight over Central and West Texas (RF 6), and a marine boundary layer (~0.2km asl) flight leg off the coast of South Carolina (RF 16). Around 1.9 ± 0.25 ppt of BrO was detected for about 1.5 hours in the high altitude flight, and around 1.0 ±0.5 ppt of BrO was detected in the marine boundary layer. Several features were present in the higher altitude air-mass with detectable BrO: O3 and humidity were significantly depressed relative to other flight legs at the same altitude and large concentrations of RM were simultaneously observed. We will present possible sources for the anomalously high BrO mixing ratios in the sampled air mass and discuss the implications of our knowledge on free-tropospheric bromine chemistry and its effects on GEM oxidation.

  13. Constraints on JN2O5 from balloon-borne limb scanning measurements of NO2 in the tropics

    NASA Astrophysics Data System (ADS)

    Kritten, Lena; Butz, Andre; Deutschmann, Tim; Dorf, Marcel; Kreycy, Sebastian; Prados-Roman, Cristina; Pfeilsticker, Klaus

    2010-05-01

    The NOx ozone cycle (NOx = NO + NO2) is of great importance for the budget of stratospheric ozone and in future may even become more important due to increasing stratospheric N2O concentrations (Ravishankara et al., 2009). A regulating process for the amount of stratospheric NOx and thus for the efficiency of the NOx mediated ozone loss cycle is photolytic release of N2O5 at daytime since N2O5 acts as a nighttime reservoir gas for stratospheric NOx radicals. Observations of UV/vis scattered skylight by balloon-borne limb scanning spectrometry support the detection of time dependent trace gas and radical profiles, in particular of NO2. Here we present balloon borne measurements of time dependent NO2 profiles from the tropical stratosphere - taken at north-eastern Brazil (5° S, 43° W) in June 2005 - where excess stratospheric ozone is produced and transported to higher latitudes by the Brewer-Dobson circulation. The photolysis rate of N2O5 - uncertain by a factor of 2 (JPL-2006) - is constrained from the comparison of the measured and modelled diurnal variation of NO2. For the photochemical model initial conditions are based on our own observations of O3 and NO2, MIPAS-B measurements and on output of the 3-D SLIMCAT model. The kinetic and thermodynamic parameters and absorption cross-sections are taken from the JPL-2006 compilation (Sander et. al, 2006). Overall it is found that, the observed rate of diurnal NO2 increase requires a N2O5 photolysis frequency at the upper limit of values possible according to the uncertainty range given by the JPL-2006 compilation. In conclusion it suggested that the NOx mediated ozone loss in the tropical stratosphere is probably larger than assumed by many photochemical models, and in future may even relatively become more important.

  14. Limb-darkening functions as derived from along-track operation of the ERBE scanning radiometers for August 1985

    NASA Technical Reports Server (NTRS)

    Smith, G. Louis; Manalo, Natividad D.; Avis, Lee M.

    1990-01-01

    During August 1985, the scanning radiometers of the Earth Radiation Budget Experiment aboard the Earth Radiation Budget Satellite (ERBS) and the NOAA-9 satellite were operated in along-track scanning modes. These data were analyzed to produce limb darkening functions for Earth-emitted radiation, which relates the radiance in any given direction to the radiant exitence. Limb darkening functions are presented and shown as figures for day and night for each spacecraft. The scene types were computed using measurements within 10 deg of zenith. The models have values near zenith of 1.02 to 1.09, with values near 1.06 being typical. The typical value of the model is 1.06 for both day and night for ERBS, and for NOAA-9, the typical value at zenith is 1.06 for day and 1.05 for night. Mean models are formed for the ERBS and for the NOAA-9 results and are found to differ less than 1 percent, the ERBS results being the higher. The models vary about 1 percent with latitude near zenith.

  15. Comparison of Data From Far Ultraviolet Limb Scanning and Imaging Instrumentation Aboard the Advanced Research and Global Observation Satellite (ARGOS)

    NASA Astrophysics Data System (ADS)

    Walker, P. W.; Carruthers, G. R.; Dymond, K. F.; Finch, M. A.; McDonald, S. E.; Nicholas, A. C.; Thonnard, S. E.; Budzien, S. A.; McCoy, R. P.

    2001-05-01

    The ARGOS satellite includes two Naval Research Laboratory experiments that monitor naturally occurring far ultraviolet emissions in the Earth's upper atmosphere. Coincident observations between these two instruments, the Global Imaging Monitor of the Ionosphere (GIMI) and the Low Resolution Airglow and Auroral Spectrograph (LORAAS), have been obtained. The GIMI instrument produces 9 ° x 9 ° limb images with passband coverage between 131 and 200 nm. The LORAAS instrument provides the spectral distribution from 80 to 170 nm for 2.4 ° x 17 ° field of regard. The two instruments are coaligned aboard the spacecraft, aft-looking in the orbital plane. Preliminary comparisons of observations obtained from the imaging and scanning instruments under quiet geomagnetic conditions are reported, including irradiances and spectral distributions. By combining the GIMI data with that from LORAAS, the study of the dynamics of the ionosphere can be expanded to investigate both horizontal and vertical distrubutions and their variances. The improved capability can extend to the study of active periods with highly variable and disturbed ionospheres, and examples are discussed from data acquired during periods of high geomagnetic activity. These results provide the first direct comparison between near simultaneous limb scans and images from ARGOS, and show promise as a validation technique to improve capabilities for the study of ionospheric variability.

  16. Study on upper limb rehabilitation system based on surface EMG.

    PubMed

    Wang, Lan; Li, Hailong; Wang, Zhengyu; Meng, Fandong

    2015-01-01

    During the rehabilitation process, it is essential to accurately judge a patient's recovery in a timely manner. A reasonable and matched training program is significant in the development of rehabilitation system. This paper presents a new upper limb rehabilitation training system, which consists of an upper limb rehabilitation training device, a current detection circuit, a motor speed test circuit, a surface EMG (sEMG) sensor, and a dSPACE HIL simulation platform. The real-time output torque of the servo motor is calculated by using the motor's real-time current and speed, in order to monitor the patient's training situation. The signal of sEMG is collected in real time and is processed with root mean square (RMS) to characterize the degree of muscle activation. Based on this rehabilitation system, maximum voluntary contraction (MVC) experiments, passive training experiments under different speeds, and active training experiments under different damping are studied. The results show that this new system performs real-time and accurate monitoring of a patient's training situation. It can also assess a patient's recovery through muscle activation. To a certain extent, this system provides a platform for research and development of rehabilitation medical engineering. PMID:26406076

  17. Center to limb scans of the Saturnian equator at 20 microns

    NASA Technical Reports Server (NTRS)

    Caldwell, J.; Gillett, F. C.; Nolt, I. G.; Tokunaga, A.

    1978-01-01

    Spatially resolved area scans of the equator of Saturn through filters at 17.8, 19.7, and 22.9 microns are used to evaluate proposed model atmospheres from the literature. The present observations demonstrate that the equatorial thermal structure has not changed measurably in the last three years.

  18. Molecular bases of autosomal recessive limb-girdle muscular dystrophies.

    PubMed

    Nigro, V

    2003-09-01

    Limb-girdle muscular dystrophies (LGMD) are a heterogeneous group of genetically determined disorders with a primary or predominant involvement of the pelvic or shoulder girdle musculature. The clinical course is characterized by great variability, ranging from severe forms with rapid onset and progression to very mild forms allowing affected people to have fairly normal life spans and activity levels. Sixteen loci have been so far identified, six autosomal dominant and ten autosomal recessive. Linkage analyses indicate that there is further genetic heterogeneity both for dominant as well as for recessive LGMD. The dominant forms (LGMD1) are generally milder and relatively rare, representing less than 10% of all LGMD. The autosomal recessive forms (LGMD2) are much more common, having a cumulative prevalence of 1:15,000 with a number of geographical differences. The product of ten autosomal recessive LGMD genes has so far been identified. They are: calpain-3 (LGMD2A), dysferlin (LGMD2B), alpha-sarcoglycan (LGMD2D), beta-sarcoglycan (LGMD2E), gamma-sarcoglycan (LGMD2C), delta-sarcoglycan (LGMD2F), telethonin (LGMD2G), TRIM32 (LGMD2H), fukutin-related protein (LGMD2I) and titin (LGMD2J). There are, however, at least 25% of families who can be excluded from any known locus. The present review is devoted to outline the present advancements in the molecular bases of autosomal recessive LGMD. PMID:14959561

  19. Visual Scanning Training, Limb Activation Treatment, and Prism Adaptation for Rehabilitating Left Neglect: Who is the Winner?

    PubMed Central

    Priftis, Konstantinos; Passarini, Laura; Pilosio, Cristina; Meneghello, Francesca; Pitteri, Marco

    2013-01-01

    We compared, for the first time, the overall and differential effects of three of the most widely used left neglect (LN) treatments: visual scanning training (VST), limb activation treatment (LAT), and prism adaptation (PA). Thirty-three LN patients were assigned in quasi-random order to the three groups (VST, LAT, or PA). Each patient received only one type of treatment. LN patients’ performance on everyday life tasks was assessed four times (over a period of 6 weeks): A1 and A2 (i.e., the two pre-treatment assessments); A3 and A4 (i.e., the two post-treatment assessments). LN patients in each of the three treatment conditions were treated for the same number of sessions (i.e., 20). The results showed that improvements were present in the majority of the tests assessing the peripersonal space in everyday life activities. Our findings were independent of unspecific factors and lasted for at least 2 weeks following the end of the treatments. There were no interactions, however, between LN treatments and assessments. We suggest that all three treatments can be considered as valid rehabilitation interventions for LN and could be employed for ameliorating LN signs. PMID:23847520

  20. Making sense-data-based simulations of vertebrate limb development.

    PubMed

    Iber, Dagmar; Zeller, Rolf

    2012-12-01

    Limb bud development has been studied for decades and contributed a wealth of knowledge to our understanding of the molecular and cellular mechanisms that govern organogenesis in vertebrate embryos. However, the general regulatory paradigms that underlie the functional and structural organization of complex systems such as developing limb buds have remained largely elusive. A significant number of mathematical theories have been proposed to explain these developmental processes, but have rarely been validated by experimental analysis. In the age of systems biology, experimental and mathematical approaches have become interlinked and enable the experimental validation of computational models by molecular and genetic analysis. This in turn allows refinement of the mathematical simulations such that simulating limb bud development becomes increasingly more realistic. The resulting models not only detect inconsistencies in the interpretation of experimental data, but their predictive power facilitates identification of key regulatory interactions and definition of so-called core and accessory mechanisms. The ongoing integrative analysis of vertebrate limb organogenesis indicates that these network simulations may be suitable for in silico genetics, that is the computational modeling of complex loss-of-functions and gain-of-functions states. Such in silico genetic approaches will permit the simulation of complex mutant phenotypes tedious or impossible to generate using mouse molecular genetics. PMID:23266216

  1. A limb atmospheric radiance inversion method based on a sun-synchronous orbit satellite

    NASA Astrophysics Data System (ADS)

    Dong, Yucui; Chen, Fansheng; Wang, Yun; Su, Xiaofeng; Wang, Wei

    2015-04-01

    It is always affected by the influence of limb atmosphere when the space-based remote sensing systems detect spatial targets using limb observation mode. In this paper, the characteristics of the limb atmosphere and the impact of limb atmosphere to target observation are theoretical modeled. Based on the model, we propose an algorithm to compute the vertical structure of atmosphere radiance through the image of limb atmosphere as well as the star image. Realization of atmosphere radiance under similar situation can then be computed based on inversion algorithm proposed in the paper. The stellar images of different areas including areas over Antarctic and Equator are captured by in-orbit space borne camera. The method of how to inverse from the gray image to atmosphere limb radiance in engineering applications is described in detail and statistical analysis of the result of inversion to limb atmosphere radiance is conducted whose trend is consistent with simulation result of MODTRAN which increases at lower altitude to a peak value then drop to zero slowly while there are two peaks in the statistical radiance distribution curves illustrating the polar light over Antarctic.

  2. Mechanism of Kinect-based virtual reality training for motor functional recovery of upper limbs after subacute stroke

    PubMed Central

    Bao, Xiao; Mao, Yurong; Lin, Qiang; Qiu, Yunhai; Chen, Shaozhen; Li, Le; Cates, Ryan S.; Zhou, Shufeng; Huang, Dongfeng

    2013-01-01

    The Kinect-based virtual reality system for the Xbox 360 enables users to control and interact with the game console without the need to touch a game controller, and provides rehabilitation training for stroke patients with lower limb dysfunctions. However, the underlying mechanism remains unclear. In this study, 18 healthy subjects and five patients after subacute stroke were included. The five patients were scanned using functional MRI prior to training, 3 weeks after training and at a 12-week follow-up, and then compared with healthy subjects. The Fugl-Meyer Assessment and Wolf Motor Function Test scores of the hemiplegic upper limbs of stroke patients were significantly increased 3 weeks after training and at the 12-week follow-up. Functional MRI results showed that contralateral primary sensorimotor cortex was activated after Kinect-based virtual reality training in the stroke patients compared with the healthy subjects. Contralateral primary sensorimotor cortex, the bilateral supplementary motor area and the ipsilateral cerebellum were also activated during hand-clenching in all 18 healthy subjects. Our findings indicate that Kinect-based virtual reality training could promote the recovery of upper limb motor function in subacute stroke patients, and brain reorganization by Kinect-based virtual reality training may be linked to the contralateral sensorimotor cortex. PMID:25206611

  3. Acute limb ischemia caused by incorrect deployment of a clip-based arterial closure device

    PubMed Central

    Dzieciuchowicz, Łukasz; Stefaniak, Karolina; Oszkinis, Grzegorz

    2016-01-01

    Failure of a vascular closure device most commonly results in a hemorrhage or pseudoaneurysm formation. In this paper a rare case of severe acute limb ischemia following incorrect deployment of a clip-based closure device (Starclose SE, Abbott Vascular) in a 31-year-old woman is presented. Symptoms of acute limb ischemia occurred at the start of the ambulation, 6 h after completion of the procedure. Because of the severity of ischemia the patient was treated surgically, and limb perfusion was successfully restored. An attempt of closure of an inadvertently punctured narrow superficial femoral artery was identified as the cause of this complication. PMID:27458492

  4. Compact and Light-Weight Solar Spaceflight Instrument Designs Utilizing Newly Developed Miniature Free-Standing Zone Plates: EUV Radiometer and Limb-Scanning Monochromator

    NASA Astrophysics Data System (ADS)

    Seely, J. F.; McMullin, D. R.; Bremer, J.; Chang, C.; Sakdinawat, A.; Jones, A. R.; Vest, R.

    2014-12-01

    Two solar instrument designs are presented that utilize newly developed miniature free-standing zone plates having interconnected Au opaque bars and no support membrane resulting in excellent long-term stability in space. Both instruments are based on a zone plate having 4 mm outer diameter and 1 to 2 degree field of view. The zone plate collects EUV radiation and focuses a narrow bandpass through a pinhole aperture and onto a silicon photodiode detector. As a miniature radiometer, EUV irradiance is accurately determined from the zone plate efficiency and the photodiode responsivity that are calibrated at the NIST SURF synchrotron facility. The EUV radiometer is pointed to the Sun and measures the absolute solar EUV irradiance in high time cadence suitable for solar physics and space weather applications. As a limb-scanning instrument in low earth orbit, a miniature zone-plate monochromator measures the extinction of solar EUV radiation by scattering through the upper atmosphere which is a measure of the variability of the ionosphere. Both instruments are compact and light-weight and are attractive for CubeSats and other missions where resources are extremely limited.

  5. Low cost PC based scanning Kelvin probe

    NASA Astrophysics Data System (ADS)

    Baikie, I. D.; Estrup, P. J.

    1998-11-01

    We have developed a novel, low cost, scanning Kelvin probe (SKP) system that can measure work function (wf) and surface potential (sp) topographies to within 1 meV energy resolution. The control and measurement subcomponents are PC based and incorporate a flexible user interface, permitting software control of major parameters and allowing easy user implementation via automatic setup and scanning procedures. We review the mode of operation and design features of the SKP including the digital oscillator, the compact ambient voice-coil head-stage, and signal processing techniques. This system offers unique tip-to-sample spacing control (to within 40 nm) which provides a method of simultaneously imaging sample height topographies and is essential to avoid spurious or "apparent" wf changes due to scanning-induced spacing changes. We illustrate SKP operation in generating high resolution wf/sp profiles of metal interfaces (as a tip characterization procedure) and operational electronic devices. The SKP potentially has a very wide range of applications ranging from semiconductor quality control thin film and surface analyses to corrosion and biopotential imaging.

  6. Synthetic holography based on scanning microcavity

    NASA Astrophysics Data System (ADS)

    Di Donato, A.; Farina, M.

    2015-11-01

    Synthetic optical holography (SOH) is an imaging technique, introduced in scanning microscopy to record amplitude and phase of a scattered field from a sample. In this paper, it is described a novel implementation of SOH through a lens-free low-coherence system, based on a scanning optical microcavity. This technique combines the low-coherence properties of the source with the mutual interference of scattered waves and the resonant behavior of a micro-cavity, in order to realize a high sensitive imaging system. Micro-cavity is compact and realized by approaching a cleaved optical fiber to the sample. The scanning system works in an open-loop configuration without the need for a reference wave, usually required in interferometric systems. Measurements were performed over calibration samples and a lateral resolution of about 1 μm is achieved by means of an optical fiber with a Numerical Aperture (NA) equal to 0.1 and a Mode Field Diameter (MDF) of 5.6 μm.

  7. Spin scan tomographic array-based imager.

    PubMed

    Hovland, Harald

    2014-12-29

    This work presents a novel imaging device based on tomographic reconstruction. Similar in certain aspects to the earlier presented tomographic scanning (TOSCA) principle, it provides several important enhancements. The device described generates a stream of one-dimensional projections from a linear array of thin stripe detectors onto which the (circular) image of the scene is rotated. A two-dimensional image is then reproduced from the one-dimensional signals using tomographic processing techniques. A demonstrator is presented. Various aspects of the design and construction are discussed, and resulting images and movies are presented. PMID:25607168

  8. Self-delivered home-based mirror therapy for lower limb phantom pain.

    PubMed

    Darnall, Beth D

    2009-01-01

    Home-based patient-delivered mirror therapy is a promising approach in the treatment of phantom limb pain. Previous studies and case reports of mirror therapy have used a therapist-guided, structured protocol of exercises. No case report has described treatment for either upper or lower limb phantom pain by using home-based patient-delivered mirror therapy. The success of this case demonstrates that home-based patient-delivered mirror therapy may be an efficacious, low-cost treatment option that would eliminate many traditional barriers to care. PMID:19096290

  9. SCAN+

    SciTech Connect

    Kenneth Krebs, John Svoboda

    2009-11-01

    SCAN+ is a software application specifically designed to control the positioning of a gamma spectrometer by a two dimensional translation system above spent fuel bundles located in a sealed spent fuel cask. The gamma spectrometer collects gamma spectrum information for the purpose of spent fuel cask fuel loading verification. SCAN+ performs manual and automatic gamma spectrometer positioning functions as-well-as exercising control of the gamma spectrometer data acquisitioning functions. Cask configuration files are used to determine the positions of spent fuel bundles. Cask scanning files are used to determine the desired scan paths for scanning a spent fuel cask allowing for automatic unattended cask scanning that may take several hours.

  10. SCAN+

    Energy Science and Technology Software Center (ESTSC)

    2009-11-01

    SCAN+ is a software application specifically designed to control the positioning of a gamma spectrometer by a two dimensional translation system above spent fuel bundles located in a sealed spent fuel cask. The gamma spectrometer collects gamma spectrum information for the purpose of spent fuel cask fuel loading verification. SCAN+ performs manual and automatic gamma spectrometer positioning functions as-well-as exercising control of the gamma spectrometer data acquisitioning functions. Cask configuration files are used to determinemore » the positions of spent fuel bundles. Cask scanning files are used to determine the desired scan paths for scanning a spent fuel cask allowing for automatic unattended cask scanning that may take several hours.« less

  11. Scan MDCs for GPS-Based Gamma Radiation Surveys.

    PubMed

    Alecksen, Tyler; Whicker, Randy

    2016-08-01

    A method for estimating the minimum detectable concentration of a contaminant radionuclide in soil when scanning with gamma radiation detectors (known as the "scan MDC") is described in the Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM). This paper presents an alternate method for estimating scan MDCs for GPS-based gamma surveys based on detector efficiencies modeled with the probabilistic Monte Carlo N-Particle Extended (MCNPX) Transport simulation code. Results are compared to those provided in MARSSIM. An extensive database of MCNPX-based detection efficiencies has been developed to represent a variety of gamma survey applications and potential scanning configurations (detector size, scan height, size of contaminated soil volume, etc.), and an associated web-based user interface has been developed to provide survey designers and regulators with access to a reasonably wide range of calculated scan MDC values for survey planning purposes. PMID:27356162

  12. Handheld Thermoacoustic Scanning System Based on a Linear-array Transducer.

    PubMed

    Ji, Zhong; Ding, Wenzheng; Ye, Fanghao; Lou, Cunguang

    2016-07-01

    To receive the information necessary for imaging, traditional microwave-induced thermoacoustic imaging systems (MITISs) use a type of circular-scanning mode using single or arc detectors. However, the use of MITISs for body scanning is complicated by restrictions in space and imaging time. A linear-array detector, the most widely used transducer in medical ultrasound imaging systems for body scanning, is a possible alternative to MITISs for scanning biological tissues, such as from the breast or limbs. In this paper, a handheld MITIS, based on a linear-array detector and a multiple data acquisition system, is described, and the capacity of the system is explored experimentally. First, the vertical and lateral resolution of the system is discussed. Next, real-time imaging of a moving object, obtained with an image capture rate of 20 frame/s, is described. Finally, a phantom experiment is detailed, investigating the overall imaging capability. The results show that this system achieves rapid scanning with a large field of view. The system has the obvious advantages of being handheld, not using coupled fluids, and achieving real-time imaging with a large field of view, which make this MITIS more suitable for clinical applications. PMID:26294659

  13. Prevalence and Risk Factors for Diabetic Lower Limb Amputation: A Clinic-Based Case Control Study

    PubMed Central

    Rodrigues, Beverly T.; Vangaveti, Venkat N.

    2016-01-01

    Objective. The aim of the study was to evaluate the prevalence of and risk factors for lower limb amputation in a specialist foot clinic-based setting. Methods. A retrospective quantitative study was conducted, using clinical and biochemical profiles of diabetic foot patients attending the High Risk Foot Clinic at The Townsville Hospital, Australia, between January 1, 2011, and December 31, 2013. Results. The total study sample included 129 subjects, comprising 81 males and 48 females with M : F ratio of 1.7 : 1. Twenty-three subjects were Indigenous Australians, representing 17.8% of the study population. The average age of the cohort was 63.4 years ± 14.1 years [CI 90.98–65.89]. Lower limb amputation was identified as a common and significant outcome (n = 44), occurring in 34.1%, more commonly amongst the Indigenous Australians (56.5% versus 29.2%; p = 0.94, OR 0.94). Risk factors most closely associated with amputation included diabetic retinopathy (p = 0.00, OR 4.4), coronary artery bypass graft (CABG) surgery (p = 0.01, OR 4.1), Charcot's arthropathy (p = 0.01, OR 2.9), and Indigenous ethnicity (p = 0.01, OR 3.4). Although average serum creatinine, corrected calcium, and glycosylated haemoglobin A1c (Hba1c) levels were higher amongst amputees they were statistically insignificant. Conclusions. Lower limb amputation is a common outcome and linked to ethnicity and neurovascular diabetic complications amongst subjects with diabetic foot ulcer. Further research is needed to identify why risk of lower limb amputation seems to differ according to ethnicity. PMID:27446962

  14. Prevalence and Risk Factors for Diabetic Lower Limb Amputation: A Clinic-Based Case Control Study.

    PubMed

    Rodrigues, Beverly T; Vangaveti, Venkat N; Malabu, Usman H

    2016-01-01

    Objective. The aim of the study was to evaluate the prevalence of and risk factors for lower limb amputation in a specialist foot clinic-based setting. Methods. A retrospective quantitative study was conducted, using clinical and biochemical profiles of diabetic foot patients attending the High Risk Foot Clinic at The Townsville Hospital, Australia, between January 1, 2011, and December 31, 2013. Results. The total study sample included 129 subjects, comprising 81 males and 48 females with M : F ratio of 1.7 : 1. Twenty-three subjects were Indigenous Australians, representing 17.8% of the study population. The average age of the cohort was 63.4 years ± 14.1 years [CI 90.98-65.89]. Lower limb amputation was identified as a common and significant outcome (n = 44), occurring in 34.1%, more commonly amongst the Indigenous Australians (56.5% versus 29.2%; p = 0.94, OR 0.94). Risk factors most closely associated with amputation included diabetic retinopathy (p = 0.00, OR 4.4), coronary artery bypass graft (CABG) surgery (p = 0.01, OR 4.1), Charcot's arthropathy (p = 0.01, OR 2.9), and Indigenous ethnicity (p = 0.01, OR 3.4). Although average serum creatinine, corrected calcium, and glycosylated haemoglobin A1c (Hba1c) levels were higher amongst amputees they were statistically insignificant. Conclusions. Lower limb amputation is a common outcome and linked to ethnicity and neurovascular diabetic complications amongst subjects with diabetic foot ulcer. Further research is needed to identify why risk of lower limb amputation seems to differ according to ethnicity. PMID:27446962

  15. Correcting scan-to-scan response variability for a radiochromic film-based reference dosimetry system

    SciTech Connect

    Lewis, David; Devic, Slobodan

    2015-10-15

    Purpose: In radiochromic film dosimetry systems, measurements are usually obtained from film images acquired on a CCD-based flatbed scanner. The authors investigated factors affecting scan-to-scan response variability leading to increased dose measurement uncertainty. Methods: The authors used flatbed document scanners to repetitively scan EBT3 radiochromic films exposed to doses 0–1000 cGy, together with three neutral density filters and three blue optical filters. Scanning was performed under two conditions: scanner lid closed and scanner lid opened/closed between scans. The authors also placed a scanner in a cold room at 9 °C and later in a room at 22 °C and scanned EBT3 films to explore temperature effects. Finally, the authors investigated the effect of altering the distance between the film and the scanner’s light source. Results: Using a measurement protocol to isolate the contribution of the CCD and electronic circuitry of the scanners, the authors found that the standard deviation of response measurements for the EBT3 film model was about 0.17% for one scanner and 0.09% for the second. When the lid of the first scanner was opened and closed between scans, the average scan-to-scan difference of responses increased from 0.12% to 0.27%. Increasing the sample temperature during scanning changed the RGB response values by about −0.17, −0.14, and −0.05%/°C, respectively. Reducing the film-to-light source distance increased the RBG response values about 1.1, 1.3, and 1.4%/mm, respectively. The authors observed that films and film samples were often not flat with some areas up to 8 mm away from the scanner’s glass window. Conclusions: In the absence of measures to deal with the response irregularities, each factor the authors investigated could lead to dose uncertainty >2%. Those factors related to the film-to-light source distance could be particularly impactful since the authors observed many instances where the curl of film samples had the

  16. A Kinect-based upper limb rehabilitation system to assist people with cerebral palsy.

    PubMed

    Chang, Yao-Jen; Han, Wen-Ying; Tsai, Yu-Chi

    2013-11-01

    This study assessed the possibility of rehabilitating two adolescents with cerebral palsy (CP) using a Kinect-based system in a public school setting. The system provided 3 degrees of freedom for prescribing a rehabilitation program to achieve customized treatment. This study was carried out according to an ABAB reversal replication design in which A represented the baseline and B represented intervention phases. Data showed that the two participants significantly increased their motivation for upper limb rehabilitation, thus improving exercise performance during the intervention phases. Practical and developmental implications of the findings are discussed. PMID:24012594

  17. Gesture therapy: an upper limb virtual reality-based motor rehabilitation platform.

    PubMed

    Sucar, Luis Enrique; Orihuela-Espina, Felipe; Velazquez, Roger Luis; Reinkensmeyer, David J; Leder, Ronald; Hernández-Franco, Jorge

    2014-05-01

    Virtual reality platforms capable of assisting rehabilitation must provide support for rehabilitation principles: promote repetition, task oriented training, appropriate feedback, and a motivating environment. As such, development of these platforms is a complex process which has not yet reached maturity. This paper presents our efforts to contribute to this field, presenting Gesture Therapy, a virtual reality-based platform for rehabilitation of the upper limb. We describe the system architecture and main features of the platform and provide preliminary evidence of the feasibility of the platform in its current status. PMID:24760913

  18. Dds-Based Fast Scan Spectrometer

    NASA Astrophysics Data System (ADS)

    Alekseev, E. A.; Motiyenko, R. A.; Margulès, L.

    2010-06-01

    The technique of direct digital synthesis (DDS) has two important features which enable its application in microwave spectroscopy: micro-Hz tuning resolution and extremely fast frequency switching with continuous phase. We have applied a direct digital synthesizer in a PLL-spectrometer based on backward-wave oscillator (BWO). As result we have obtained an instrument that can cover a 100 GHz bandwidth in less than one hour with high spectral resolution and high precision of frequency measurement. The application of the spectrometer to sub-millimeter wave survey spectra records of several isotopic species of astrophysical molecules (methanol, formamide, methyl formate, aziridine) will be discussed. The support of Université de Lille 1 and le Programme National de Physique Chimie du Milieu Interstellaire is gratefully acknowledged.

  19. A lower limb exoskeleton control system based on steady state visual evoked potentials

    NASA Astrophysics Data System (ADS)

    Kwak, No-Sang; Müller, Klaus-Robert; Lee, Seong-Whan

    2015-10-01

    Objective. We have developed an asynchronous brain-machine interface (BMI)-based lower limb exoskeleton control system based on steady-state visual evoked potentials (SSVEPs). Approach. By decoding electroencephalography signals in real-time, users are able to walk forward, turn right, turn left, sit, and stand while wearing the exoskeleton. SSVEP stimulation is implemented with a visual stimulation unit, consisting of five light emitting diodes fixed to the exoskeleton. A canonical correlation analysis (CCA) method for the extraction of frequency information associated with the SSVEP was used in combination with k-nearest neighbors. Main results. Overall, 11 healthy subjects participated in the experiment to evaluate performance. To achieve the best classification, CCA was first calibrated in an offline experiment. In the subsequent online experiment, our results exhibit accuracies of 91.3 ± 5.73%, a response time of 3.28 ± 1.82 s, an information transfer rate of 32.9 ± 9.13 bits/min, and a completion time of 1100 ± 154.92 s for the experimental parcour studied. Significance. The ability to achieve such high quality BMI control indicates that an SSVEP-based lower limb exoskeleton for gait assistance is becoming feasible.

  20. Scanning near field microwave microscopy based on an active resonator

    NASA Astrophysics Data System (ADS)

    Qureshi, Naser; Kolokoltsev, Oleg; Ordonez-Romero, Cesar Leonardo

    2014-03-01

    A large number of recent implementations of near field scanning microwave microscopy (NFSMM) have been based on the perturbation of a resonant cavity connected to a sharp scanning probe. In this work we present results from an alternative approach: the perturbation of a microwave source connected to a scanning tip. Based on a yittrium iron garnet (YIG) cavity ring resonator this scanning probe system has a quality factor greater than 106, which allows us to detect very small frequency shifts, which translates to a very high sensitivity in sample impedance measurements. Using a selection of representative semiconductor, metal and biological samples we show how this approach leads to unusually high sensitivity and spatial resolution. Work supported by a grant from PAPIIT, UNAM 104513.

  1. LINEAR SCANNING METHOD BASED ON THE SAFT COARRAY

    SciTech Connect

    Martin, C. J.; Martinez-Graullera, O.; Romero, D.; Ullate, L. G.; Higuti, R. T.

    2010-02-22

    This work presents a method to obtain B-scan images based on linear array scanning and 2R-SAFT. Using this technique some advantages are obtained: the ultrasonic system is very simple; it avoids the grating lobes formation, characteristic in conventional SAFT; and subaperture size and focussing lens (to compensate emission-reception) can be adapted dynamically to every image point. The proposed method has been experimentally tested in the inspection of CFRP samples.

  2. Muscle fatigue evaluation of astronaut upper limb based on sEMG and subjective assessment

    NASA Astrophysics Data System (ADS)

    Zu, Xiaoqi; Zhou, Qianxiang; Li, Yun

    2012-07-01

    All movements are driven by muscle contraction, and it is easy to cause muscle fatigue. Evaluation of muscle fatigue is a hot topic in the area of astronaut life support training and rehabilitation. If muscle gets into fatigue condition, it may reduce work efficiency and has an impact on psychological performance. Therefore it is necessary to develop an accurate and usable method on muscle fatigue evaluation of astronaut upper limb. In this study, we developed a method based on surface electromyography (sEMG) and subjective assessment (Borg scale) to evaluate local muscle fatigue. Fifteen healthy young male subjects participated in the experiment. They performed isometric muscle contractions of the upper limb. sEMG of the biceps brachii were recorded during the entire process of isotonic muscle contraction and Borg scales of muscle fatigue were collected in certain times. sEMG were divided into several parts, and then mean energy of each parts were calculated by the one-twelfth band octave method. Equations were derived based on the relationship between the mean energy of sEMG and Borg scale. The results showed that cubic curve could describe the degree of local muscle fatigue, and could be used to evaluate and monitor local muscle fatigue during the entire process.

  3. Markov Jump Linear Systems-Based Position Estimation for Lower Limb Exoskeletons

    PubMed Central

    Nogueira, Samuel L.; Siqueira, Adriano A. G.; Inoue, Roberto S.; Terra, Marco H.

    2014-01-01

    In this paper, we deal with Markov Jump Linear Systems-based filtering applied to robotic rehabilitation. The angular positions of an impedance-controlled exoskeleton, designed to help stroke and spinal cord injured patients during walking rehabilitation, are estimated. Standard position estimate approaches adopt Kalman filters (KF) to improve the performance of inertial measurement units (IMUs) based on individual link configurations. Consequently, for a multi-body system, like a lower limb exoskeleton, the inertial measurements of one link (e.g., the shank) are not taken into account in other link position estimation (e.g., the foot). In this paper, we propose a collective modeling of all inertial sensors attached to the exoskeleton, combining them in a Markovian estimation model in order to get the best information from each sensor. In order to demonstrate the effectiveness of our approach, simulation results regarding a set of human footsteps, with four IMUs and three encoders attached to the lower limb exoskeleton, are presented. A comparative study between the Markovian estimation system and the standard one is performed considering a wide range of parametric uncertainties. PMID:24451469

  4. Electromyography-based analysis of human upper limbs during 45-day head-down bed-rest

    NASA Astrophysics Data System (ADS)

    Fu, Anshuang; Wang, Chunhui; Qi, Hongzhi; Li, Fan; Wang, Zheng; He, Feng; Zhou, Peng; Chen, Shanguang; Ming, Dong

    2016-03-01

    Muscle deconditioning occurs in response to simulated or actual microgravity. In spaceflight, astronauts become monkey-like for mainly using their upper limbs to control the operating system and to complete corresponding tasks. The changes of upper limbs' athletic ability will directly affect astronauts' working performance. This study investigated the variation trend of surface electromyography (sEMG) during prolonged simulated microgravity. Eight healthy males participating in this study performed strict 45-day head-down bed-rest (HDBR). On the 5th day of pre-HDBR, and the 15th, the 30th and the 45th days of HDBR, the subjects performed maximum pushing task and maximum pulling task, and sEMG was collected from upper limbs synchronously. Each subject's maximum volunteer contractions of both the tasks during these days were compared, showing no significant change. However, changes were detected by sEMG-based analysis. It was found that integrated EMG, root mean square, mean frequency, fuzzy entropy of deltoid, and fuzzy entropy of triceps brachii changed significantly when comparing pre-HDBR with HDBR. The variation trend showed a recovery tendency after significant decline, which is inconsistent with the monotonic variation of lower limbs that was proved by previous research. These findings suggest that EMG changes in upper limbs during prolonged simulated microgravity, but has different variation trend from lower limbs.

  5. Scan-Based Implementation of JPEG 2000 Extensions

    NASA Technical Reports Server (NTRS)

    Rountree, Janet C.; Webb, Brian N.; Flohr, Thomas J.; Marcellin, Michael W.

    2001-01-01

    JPEG 2000 Part 2 (Extensions) contains a number of technologies that are of potential interest in remote sensing applications. These include arbitrary wavelet transforms, techniques to limit boundary artifacts in tiles, multiple component transforms, and trellis-coded quantization (TCQ). We are investigating the addition of these features to the low-memory (scan-based) implementation of JPEG 2000 Part 1. A scan-based implementation of TCQ has been realized and tested, with a very small performance loss as compared with the full image (frame-based) version. A proposed amendment to JPEG 2000 Part 2 will effect the syntax changes required to make scan-based TCQ compatible with the standard.

  6. Artificial Limbs

    MedlinePlus

    ... you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which ... activities such as walking, eating, or dressing. Some artificial limbs let you function nearly as well as ...

  7. Limb Loss

    MedlinePlus

    ... accidents and military combat Cancer Birth defects Some amputees have phantom pain, which is the feeling of ... problems, if you wear an artificial limb. Many amputees use an artificial limb. Learning how to use ...

  8. Are determinants for new and persistent upper limb pain different? An analysis based on anatomical sites

    PubMed Central

    Vargas-Prada, Sergio; Serra, Consol; Coggon, David; Martínez, José Miguel; Ntani, Georgia; Delclos, George; Palmer, Keith T.; Benavides, Fernando G.

    2015-01-01

    BACKGROUND Only few longitudinal studies have explored separately predictors of pain incidence and persistence. OBJECTIVE To investigate whether biological, lifestyle, occupational and psychological risk factors for the development of new episodes of upper limb pain (ULP) differ from those for its persistence. METHODS 1105 Spanish nurses and office workers were asked at baseline about biological, lifestyle, occupational and psychological risk factors and pain in the past month at six anatomical sites in the upper limb (left and right shoulder, elbow and wrist/hand). At follow up, 12 months later, pain in the past month was again ascertained. Analysis was based on anatomical sites clustered by person. Associations were assessed by multilevel logistic regression models. RESULTS 971 participants (87.9%) completed follow-up. Job dissatisfaction and older age carried higher risk of new ULP. Somatising tendency (OR 2.2, 95%CI 1.6-3.1) was the strongest predictor of new ULP, with a risk estimate which differed significantly from that for the same exposure and persistence of ULP. Having adverse beliefs about the work-relatedness of ULP carried a significantly reduced risk for persistence of ULP. CONCLUSION Our study provides only limited evidence that risk factors predicting new ULP differ from those predicting its persistence. PMID:26409386

  9. Upper limb posture estimation in robotic and virtual reality-based rehabilitation.

    PubMed

    Cortés, Camilo; Ardanza, Aitor; Molina-Rueda, F; Cuesta-Gómez, A; Unzueta, Luis; Epelde, Gorka; Ruiz, Oscar E; De Mauro, Alessandro; Florez, Julian

    2014-01-01

    New motor rehabilitation therapies include virtual reality (VR) and robotic technologies. In limb rehabilitation, limb posture is required to (1) provide a limb realistic representation in VR games and (2) assess the patient improvement. When exoskeleton devices are used in the therapy, the measurements of their joint angles cannot be directly used to represent the posture of the patient limb, since the human and exoskeleton kinematic models differ. In response to this shortcoming, we propose a method to estimate the posture of the human limb attached to the exoskeleton. We use the exoskeleton joint angles measurements and the constraints of the exoskeleton on the limb to estimate the human limb joints angles. This paper presents (a) the mathematical formulation and solution to the problem, (b) the implementation of the proposed solution on a commercial exoskeleton system for the upper limb rehabilitation, (c) its integration into a rehabilitation VR game platform, and (d) the quantitative assessment of the method during elbow and wrist analytic training. Results show that this method properly estimates the limb posture to (i) animate avatars that represent the patient in VR games and (ii) obtain kinematic data for the patient assessment during elbow and wrist analytic rehabilitation. PMID:25110698

  10. Upper Limb Posture Estimation in Robotic and Virtual Reality-Based Rehabilitation

    PubMed Central

    Cortés, Camilo; Ardanza, Aitor; Molina-Rueda, F.; Cuesta-Gómez, A.; Ruiz, Oscar E.

    2014-01-01

    New motor rehabilitation therapies include virtual reality (VR) and robotic technologies. In limb rehabilitation, limb posture is required to (1) provide a limb realistic representation in VR games and (2) assess the patient improvement. When exoskeleton devices are used in the therapy, the measurements of their joint angles cannot be directly used to represent the posture of the patient limb, since the human and exoskeleton kinematic models differ. In response to this shortcoming, we propose a method to estimate the posture of the human limb attached to the exoskeleton. We use the exoskeleton joint angles measurements and the constraints of the exoskeleton on the limb to estimate the human limb joints angles. This paper presents (a) the mathematical formulation and solution to the problem, (b) the implementation of the proposed solution on a commercial exoskeleton system for the upper limb rehabilitation, (c) its integration into a rehabilitation VR game platform, and (d) the quantitative assessment of the method during elbow and wrist analytic training. Results show that this method properly estimates the limb posture to (i) animate avatars that represent the patient in VR games and (ii) obtain kinematic data for the patient assessment during elbow and wrist analytic rehabilitation. PMID:25110698

  11. [Moving Mirror Scanning System Based on the Flexible Hinge Support].

    PubMed

    Xie, Fei; Feng, Fei; Wang, Fu-bei; Wu, Qiong-shui; Zeng, Li-bo

    2015-08-01

    In order to improve moving mirror drive of Fourier transform infrared spectrometer, we design a dynamic scanning system based on flexible hinge support. Using the flexible hinge support way and the voice coil motor drive mode. Specifically, Using right Angle with high accuracy high stability type flexible hinge support mechanism support moving mirror, dynamic mirror can be moved forward and backward driven by voice coil motor reciprocating motion, DSP control system to control the moving mirror at a constant speed. The experimental results show that the designed of moving mirror scanning system has advantages of stability direction, speed stability, superior seismic performance. PMID:26672322

  12. Electric-controlled scanning Luneburg lens based on metamaterials

    NASA Astrophysics Data System (ADS)

    Wang, Min; Huang, Cheng; Pu, Ming-Bo; Hu, Cheng-Gang; Pan, Wen-Bo; Zhao, Ze-Yu; Luo, Xian-Gang

    2013-05-01

    The feasibility of 360∘ scanning Luneburg lens based on electric-controlled metamaterial is analyzed. When the line source is fixed in the center of the lens, the direction of radiated beam can be tuned by adjusting the bias voltages distribution applied to the varactors in each unit cell. By introducing an artificial reflective plane, the gain of the antenna can be further enhanced. The minimal step of scanning angle obtained in simulation is only 7∘, which can be further decreased by increasing the dimension and the number of unit cell used in Luneburg lens.

  13. CT Scanning Imaging Method Based on a Spherical Trajectory.

    PubMed

    Chen, Ping; Han, Yan; Gui, Zhiguo

    2016-01-01

    In industrial computed tomography (CT), the mismatch between the X-ray energy and the effective thickness makes it difficult to ensure the integrity of projection data using the traditional scanning model, because of the limitations of the object's complex structure. So, we have developed a CT imaging method that is based on a spherical trajectory. Considering an unrestrained trajectory for iterative reconstruction, an iterative algorithm can be used to realise the CT reconstruction of a spherical trajectory for complete projection data only. Also, an inclined circle trajectory is used as an example of a spherical trajectory to illustrate the accuracy and feasibility of this new scanning method. The simulation results indicate that the new method produces superior results for a larger cone-beam angle, a limited angle and tabular objects compared with traditional circle trajectory scanning. PMID:26934744

  14. CT Scanning Imaging Method Based on a Spherical Trajectory

    PubMed Central

    2016-01-01

    In industrial computed tomography (CT), the mismatch between the X-ray energy and the effective thickness makes it difficult to ensure the integrity of projection data using the traditional scanning model, because of the limitations of the object’s complex structure. So, we have developed a CT imaging method that is based on a spherical trajectory. Considering an unrestrained trajectory for iterative reconstruction, an iterative algorithm can be used to realise the CT reconstruction of a spherical trajectory for complete projection data only. Also, an inclined circle trajectory is used as an example of a spherical trajectory to illustrate the accuracy and feasibility of this new scanning method. The simulation results indicate that the new method produces superior results for a larger cone-beam angle, a limited angle and tabular objects compared with traditional circle trajectory scanning. PMID:26934744

  15. Detection of defects in optics based on scanning

    NASA Astrophysics Data System (ADS)

    Zhou, Bin; Bai, Jian; Liang, Yiyong; Wang, Kaiwei; Lu, Qianbo; Zhang, Sai

    2015-08-01

    In this paper, a method to detect internal pocks and bubbles of optical elements based on laser line source scanning is proposed. In dark field environment, a laser line source is used to illuminate from one side of the glass under test, a high-resolution CCD camera is used to take pictures in front of the glass sample. Images which contain information of defects are acquired through rough scanning and accurate scanning. Accurate three-dimensional coordinates of the internal defects are acquired after image processing, which descript the characteristic information of internal defects quantificationally. Compared with the microscope imaging measurement, this proposed detection of defects in optics based on laser line source scanning has a relative aberration smaller than 2%. In addition, the detection time is approximately reduced to 20 minutes from 1 hour dramatically. The analysis indicates that the error of the position of defects is much smaller than the size of them, which means the position of the defects can be acquired accurately by this approach.

  16. An accelerometry-based study of lower and upper limb tremor in Parkinson's disease.

    PubMed

    Scanlon, Blake K; Levin, Bonnie E; Nation, Daniel A; Katzen, Heather L; Guevara-Salcedo, Alexandra; Singer, Carlos; Papapetropoulos, Spiridon

    2013-06-01

    Over the past two decades, several studies have aimed to quantify the kinetic properties of tremor with primary focus on the upper limbs. However, there is a lack of investigation into the properties of tremor in the lower limbs. The objective of this preliminary study was to investigate the properties of oscillatory movement, at rest and in posture, in both the upper and lower limbs of Parkinson's disease (PD) patients with clinically undetectable to modest rest/postural tremor and healthy controls. PD patients (N = 16) and controls (N = 8) were examined clinically by a movement disorders specialist and oscillatory movements in all four extremities were evaluated using a portable biaxial accelerometer. While tremor intensity and frequency did not differ between groups, the intraindividual variability of rest and postural tremor frequency in the dexterity-dominant lower limb was lower in people living with PD than in healthy adults. Additionally, rest tremor frequency was discrepant between upper and lower limbs in PD. Our work introduces the possibility that minute variations in lower limb movements, which are imperceptible upon expert clinical exam, can be used to differentiate a diseased sample from a healthy one. These preliminary findings suggest that additional work using objective tremor measurement may improve our understanding of lower limb motor dysfunction in PD and lead to the refinement of current, and the development of new, metrics to enhance early diagnosis, differential diagnosis, and symptom quantification. PMID:23639618

  17. Comparison of stratospheric NO2 profiles above Kiruna, Sweden retrieved from ground-based zenith sky DOAS measurements, SAOZ balloon measurements and SCIAMACHY limb observations

    NASA Astrophysics Data System (ADS)

    Gu, Myojeong; Enell, Carl-Fredrik; Hendrick, François; Pukite, Janis; Van Roozendael, Michel; Platt, Ulrich; Raffalski, Uwe; Wagner, Thomas

    2015-04-01

    Stratospheric NO2 not only destroys ozone but acts as a buffer against halogen catalyzed ozone loss by converting halogen species into stable nitrates. These two roles of stratospheric NO2 depend on the altitude. Hence, the objective of this study is to investigate the vertical distribution of stratospheric NO2. We compare the NO2 profiles derived from the zenith sky DOAS with those obtained from, SAOZ balloon measurements and satellite limb observations. Vertical profiles of stratospheric NO2 are retrieved from ground-based zenith sky DOAS observations operated at Kiruna, Sweden (68.84°N, 20.41°E) since 1996. To determine the profile of stratospheric NO2 measured from ground-based zenith sky DOAS, we apply the Optimal Estimation Method (OEM) to retrieval of vertical profiles of stratospheric NO2 which has been developed by IASB-BIRA. The basic principle behind this profiling approach is the dependence of the mean scattering height on solar zenith angle (SZA). We compare the retrieved profiles to two additional datasets of stratospheric NO2 profile. The first one is derived from satellite limb observations by SCIAMACHY (Scanning Imaging Absorption spectrometer for Atmospheric CHartographY) on EnviSAT. The second is derived from the SAOZ balloon measurements (using a UV/Visible spectrometer) performed at Kiruna in Sweden.

  18. Realization of Intelligent Measurement and Control System for Limb Rehabilitation Based on PLC and Touch Screen

    NASA Astrophysics Data System (ADS)

    Liu, Xiangquan

    According to the treatment needs of patients with limb movement disorder, on the basis of the limb rehabilitative training prototype, function of measure and control system are analyzed, design of system hardware and software is completed. The touch screen which is adopt as host computer and man-machine interaction window is responsible for sending commands and training information display; The PLC which is adopt as slave computer is responsible for receiving control command from touch screen, collecting the sensor data, regulating torque and speed of motor by analog output according to the different training mode, realizing ultimately active and passive training for limb rehabilitation therapy.

  19. Brightness of the photosphere and faculae at the limb based on eclipse observations

    SciTech Connect

    Akimov, L.A.; Belkina, I.L.; Dyatel, N.P.

    1982-05-01

    The absolute distributions of integral and surface brightness of the photospheric continuum (lambdaroughly-equal5870 A) and in faculae at the very limb are obtained from slitless spectrograms of the total solar eclipse of July 10, 1972. Several possible reasons for the brightness increase toward the limb in the distribution of photospheric surface brightness are discussed. The faculae showed high contrasts, up to 1.76 at a height of 200 km from the limb. A comparison of the times of local contacts observed and calculated with allowance for lunar relief showed that the active regions are at about 300 km above the photosphere. A schematic model of a facula is proposed.

  20. Observational Verification of the Limb-Darkening Law Based on Kepler Data

    NASA Astrophysics Data System (ADS)

    Zola, S.; Baran, A.; Debski, B.; Jableka, D.

    2015-07-01

    We present preliminary results obtained from modeling of light curves of a sample of contact binaries observed by the Kepler spacecraft. Our study was aimed at verifying which of the three most commonly used limb-darkening formulations fits the high quality Kepler data the best. We limited our work to twelve binary systems showing flat-bottomed minima, and we found that for ten of them the square root limb-darkening law led to the best fits.

  1. Segment based shape matching in terrestrial laser scanning point clouds

    NASA Astrophysics Data System (ADS)

    Bremer, Magnus; Rutzinger, Martin; Wichmann, Volker

    2013-04-01

    Change detection of dynamic surface elements is an important application in geomorphological analysis. In order to be able to investigate such changes, the high spatial resolution and accuracy of the laser scanning technology is exploited. Dealing with laser scanning data, most change detection approaches are aiming at the assessment of volumetric changes due to erosion and deposition by geomorphologic processes. In these cases the areas of erosion and deposition are spatially separated and can be investigated in a cut-and-fill analysis. Where slow changes are controlled by interior deformation of material mixtures due to gravity, surface changes are mostly due to slight movements of objects and not to absolute material losses and gains. In complex terrain an object-based approach for the reconstruction of 3D change vectors is required. Depending on the level of scale, terrain can be subdivided into a large number of small planar patches. Using 3D point cloud data from terrestrial laser scanning, this can be done by a planar segmentation procedure grouping laser points of flat surfaces. Rotating each point cloud segment into its best fit plane, its 2D footprint shows specific local surface characteristics. Thus, each surface patch has a unique fingerprint that can be described by a variety of segment features. In an experimental framework we test the capability of shape based matching for the derivation of change vectors on dynamic surfaces. To consider different data characteristics such as varying point densities and scan perspectives, terrestrial laser scans of a rock glacier are acquired from three positions with an Optech ILRIS3D terrestrial laser scanner. Additionally, the point density is manipulated in order to simulate three different levels of point density. For the matching of surface patches, we test various non-metric shape features such as roundness, concavity and elongation. Besides, we use metric shape features such as patch area, perimeter and the

  2. Optimization of Designs for Nanotube-based Scanning Probes

    NASA Technical Reports Server (NTRS)

    Harik, V. M.; Gates, T. S.; Bushnell, Dennis M. (Technical Monitor)

    2002-01-01

    Optimization of designs for nanotube-based scanning probes, which may be used for high-resolution characterization of nanostructured materials, is examined. Continuum models to analyze the nanotube deformations are proposed to help guide selection of the optimum probe. The limitations on the use of these models that must be accounted for before applying to any design problem are presented. These limitations stem from the underlying assumptions and the expected range of nanotube loading, end conditions, and geometry. Once the limitations are accounted for, the key model parameters along with the appropriate classification of nanotube structures may serve as a basis for the design optimization of nanotube-based probe tips.

  3. Steering knuckle diameter measurement based on optical 3D scanning

    NASA Astrophysics Data System (ADS)

    Song, Li-mei; Li, Da-peng; Chang, Yu-lan; Xi, Jiang-tao; Guo, Qing-hua

    2014-11-01

    To achieve accurate measurements, the creating a fitting hole for internal diameter (CFHID) measurement method and the establishing multi-sectional curve for external diameter (EMCED) measurement method are proposed in this paper, which are based on computer vision principle and three-dimensional (3D) reconstruction. The methods are able to highlight the 3D characteristics of the scanned object and to achieve the accurate measurement of 3D data. It can create favorable conditions for realizing the reverse design and 3D reconstruction of scanned object. These methods can also be applied to dangerous work environment or the occasion that traditional contact measurement can not meet the demands, and they can improve the security in measurement.

  4. Multi-perspective scanning microscope based on Talbot effect

    NASA Astrophysics Data System (ADS)

    Sun, Yangyang; Pang, Shuo

    2016-01-01

    We report a multi-perspective scanning microscope based on the Talbot effect of a periodic focal spot array. Talbot illumination decouples the lateral scanning and the focal spots tuning. Large field of view fluorescence Talbot Microscope has been demonstrated by globally changing the incident wavefront gradient. Here, we explore the design freedom of adjusting the wavefront locally within each period and thus engineer the point spread function of the focal spots. We demonstrate an imaging system capable of reconstructing multi-perspective microscopic images in both bright field and fluorescence mode. With the multi-perspective imaging capability, we envision a more robust microscopic imaging system for large field of view fluorescence microscopy applications. This method is also suitable for compact imaging systems for multi-layer microfluidic systems.

  5. Tip Based Nanofabrication Using Multi-mode Scanning Probe Microscopy

    NASA Astrophysics Data System (ADS)

    Hu, Weihua

    Scanning probe microscopy (SPM) based nanotechnology is a promising technology in nano-device fabrication. It is able to both manipulate nanostructures and characterize the created nanopatterns using the nano-tip of the scanning probe on a mechanical basis or electrical basis. With the tip and device on similar scales, nano-tip based fabrication permits accurate control over the device geometry through tip manipulation with nanometer (or better) accuracy. However, SPM based nanofabrication is a slow process because the scanning velocity of the microscopy is low. Large, multi-tip arrays offer the possibility for parallel device fabrication, allowing mass fabrication with nanometer control. The goal of Tip-directed Field-emission Assisted Nanofabrication (TFAN) project was to realize parallel fabrication using our probe arrays. We started by fabricating nanodevice using one single probe. In this work, we investigated the study of fabricating single electron transistor (SET) using one single SPM probe. There were four stages we went through toward fabricating a SET. The first stage was to accomplish atomic-precision lithography in TFAN system. Atomic level lithography was achieved by desorbing hydrogen atoms, which were previously adsorbed to the Si(100)-2 × 1 surface, in ultrahigh vacuum scanning tunneling microscopy (UHV-STM). The second stage was to develop method for fabricating SET. SPM based local oxidation was chosen as the method to fabricate a SET on a thin titanium (Ti) film. A multi-mode SPM oxidation method was developed, in which both scanning tunneling microscopy (STM) mode and atomic microscopy (AFM) mode local oxidation were used to fabricated Ti-TiOx-Ti structures with the same conductive AFM probe. This multi-mode method enabled significantly fine feature size control by STM mode, working on insulating SiO2 substrates needed to isolate the device by AFM mode and in situ electrical characterization with conductive AFM mode. After developing the multi

  6. User training for pattern recognition-based myoelectric prostheses: improving phantom limb movement consistency and distinguishability.

    PubMed

    Powell, Michael A; Kaliki, Rahul R; Thakor, Nitish V

    2014-05-01

    We assessed the ability of four transradial amputees to control a virtual prosthesis capable of nine classes of movement both before and after a two-week training period. Subjects attended eight one-on-one training sessions that focused on improving the consistency and distinguishability of their hand and wrist movements using visual biofeedback from a virtual prosthesis. The virtual environment facilitated the precise quantification of three prosthesis control measures. During a final evaluation, the subject population saw an average increase in movement completion percentage from 70.8% to 99.0%, an average improvement in normalized movement completion time from 1.47 to 1.13, and an average increase in movement classifier accuracy from 77.5% to 94.4% (p<0.001). Additionally, all four subjects were reevaluated after eight elapsed hours without retraining the classifier, and all subjects demonstrated minimal decreases in performance. Our analysis of the underlying sources of improvement for each subject examined the sizes and separation of high-dimensional data clusters and revealed that each subject formed a unique and effective strategy for improving the consistency and/or distinguishability of his or her phantom limb movements. This is the first longitudinal study designed to examine the effects of user training in the implementation of pattern recognition-based myoelectric prostheses. PMID:24122566

  7. Large Aperture Scanning Lidar Based on Holographic Optical Elements

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.; Miller, David O.; Wilkerson, Thomas D.; Andrus, Ionio; Guerra, David V.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Lidar remote sensing instruments can make a significant contribution to satisfying many of the required measurements of atmospheric and surface parameters for future spaceborne platforms, including topographic altimeters, atmospheric profiles of, wind, humidity, temperature, trace molecules, aerosols, and clouds. It is highly desirable to have wide measurement swaths for rapid coverage rather than just the narrow ribbon of data that is obtained with a nadir only observation. For most applications global coverage is required, and for wind measurements scanning or pointing is required in order to retrieve the full 3-D wind vector from multiple line-of-sight Doppler measurements. Conventional lidar receivers make up a substantial portion of the instrument's size and weight. Wide angle scanning typically requires a large scanning mirror in front of the receiver telescope, or pointing the entire telescope and aft optics assembly, Either of these methods entails the use of large bearings, motors, gearing and their associated electronics. Spaceborne instruments also need reaction wheels to counter the torque applied to the spacecraft by these motions. NASA has developed simplified conical scanning telescopes using Holographic Optical Elements (HOEs) to reduce the size, mass, angular momentum, and cost of scanning lidar systems. NASA has developed two operating lidar systems based on 40 cm diameter HOEs. The first such system, named Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing (PHASERS) was a joint development between NASA Goddard Space Flight Center (GSFC) and the University of Maryland College Park. PHASERS is based on a reflection HOE for use at the doubled Nd:YAG laser wavelength of 532 nm and has recently undergone a number of design changes in a collaborative effort between GSFC and Saint Anselm College in New Hampshire. The next step was to develop IR transmission HOEs for use with the Nd:YAG fundamental in the Holographic Airborne

  8. LIMB demonstration project extension

    SciTech Connect

    Not Available

    1990-09-21

    The purpose of the DOE limestone injection multistage burner (LIMB) Demonstration Project Extension is to extend the data base on LIMB technology and to expand DOE's list of Clean Coal Technologies by demonstrating the Coolside process as part of the project. The main objectives of this project are: to demonstrate the general applicability of LIMB technology by testing 3 coals and 4 sorbents (total of 12 coal/sorbent combinations) at the Ohio Edison Edgewater plant; and to demonstrate that Coolside is a viable technology for improving precipitator performance and reducing sulfur dioxide emissions while acceptable operability is maintained. Progress is reported. 3 figs.

  9. Large Aperture Scanning Lidar Based on Holographic Optical Elements

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.; Miller, David O.; Wilkerson, Thomas D.; Andrus, Ionio; Guerra, David V.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Lidar remote sensing instruments can make a significant contribution to satisfying many of the required measurements of atmospheric and surface parameters for future spaceborne platforms, including topographic altimeters, atmospheric profiles of, wind, humidity, temperature, trace molecules, aerosols, and clouds. It is highly desirable to have wide measurement swaths for rapid coverage rather than just the narrow ribbon of data that is obtained with a nadir only observation. For most applications global coverage is required, and for wind measurements scanning or pointing is required in order to retrieve the full 3-D wind vector from multiple line-of-sight Doppler measurements. Conventional lidar receivers make up a substantial portion of the instrument's size and weight. Wide angle scanning typically requires a large scanning mirror in front of the receiver telescope, or pointing the entire telescope and aft optics assembly, Either of these methods entails the use of large bearings, motors, gearing and their associated electronics. Spaceborne instruments also need reaction wheels to counter the torque applied to the spacecraft by these motions. NASA has developed simplified conical scanning telescopes using Holographic Optical Elements (HOEs) to reduce the size, mass, angular momentum, and cost of scanning lidar systems. NASA has developed two operating lidar systems based on 40 cm diameter HOEs. The first such system, named Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing (PHASERS) was a joint development between NASA Goddard Space Flight Center (GSFC) and the University of Maryland College Park. PHASERS is based on a reflection HOE for use at the doubled Nd:YAG laser wavelength of 532 nm and has recently undergone a number of design changes in a collaborative effort between GSFC and Saint Anselm College in New Hampshire. The next step was to develop IR transmission HOEs for use with the Nd:YAG fundamental in the Holographic Airborne

  10. Spot-Scanning-Based Proton Therapy for Extracranial Chordoma

    SciTech Connect

    Staab, Adrian; Rutz, Hans Peter; Ares, Carmen; Timmermann, Beate; Schneider, Ralf; Bolsi, Alessandra; Albertini, Francesca; Lomax, Antony; Goitein, Gudrun; Hug, Eugen

    2011-11-15

    Purpose: To evaluate effectiveness and safety of spot-scanning-based proton-radiotherapy (PT) for extracranial chordomas (ECC). Methods and Material: Between 1999-2006, 40 patients with chordoma of C-, T-, and L-spine and sacrum were treated at Paul Scherrer Institute (PSI) with PT using spot-scanning. Median patient age was 58 years (range, 10-81 years); 63% were male, and 36% were female. Nineteen patients (47%) had gross residual disease (mean 69 cc; range, 13-495 cc) before PT, and 21 patients (53%) had undergone prior titanium-based surgical stabilization (SS) and reconstruction of the axial skeleton. Proton doses were expressed as Gy(RBE). A conversion factor of 1.1 was used to account for higher relative biological effectiveness (RBE) of protons compared with photons. Mean total dose was 72.5 Gy(RBE) [range, 59.4-75.2 Gy(RBE)] delivered at 1.8-2.0 Gy(RBE) dose per fraction. Median follow-up time was 43 months. Results: In 19 patients without surgical stabilization, actuarial local control (LC) rate at 5 years was 100%. LC for patients with gross residual disease but without surgical stabilization was also 100% at 5 years. In contrast, 12 failures occurred in 21 patients with SS, yielding a significantly decreased 5-year LC rate of 30% (p = 0.0003). For the entire cohort, 5-year LC rates were 62%, disease-free survival rates were 57%, and overall survival rates were 80%. Rates were 100% for patients without SS. No other factor, including dosimetric parameters (V95, V80) were predictive for tumor control on univariate analysis. Conclusion: Spot-scanning-based PT at PSI delivered subsequently to function-preserving surgery for tumor debulking, decompression of spinal cord, or biopsy only is safe and highly effective in patients with ECC without major surgical instrumentation even in view of large, unresectable disease.

  11. A Scan-Based Attack Based on Discriminators for AES Cryptosystems

    NASA Astrophysics Data System (ADS)

    Nara, Ryuta; Togawa, Nozomu; Yanagisawa, Masao; Ohtsuki, Tatsuo

    A scan chain is one of the most important testing techniques, but it can be used as side-channel attacks against a cryptography LSI. We focus on scan-based attacks, in which scan chains are targeted for side-channel attacks. The conventional scan-based attacks only consider the scan chain composed of only the registers in a cryptography circuit. However, a cryptography LSI usually uses many circuits such as memories, micro processors and other circuits. This means that the conventional attacks cannot be applied to the practical scan chain composed of various types of registers. In this paper, a scan-based attack which enables to decipher the secret key in an AES cryptography LSI composed of an AES circuit and other circuits is proposed. By focusing on bit pattern of the specific register and monitoring its change, our scan-based attack eliminates the influence of registers included in other circuits than AES. Our attack does not depend on scan chain architecture, and it can decipher practical AES cryptography LSIs.

  12. A Neural Network-Based Gait Phase Classification Method Using Sensors Equipped on Lower Limb Exoskeleton Robots

    PubMed Central

    Jung, Jun-Young; Heo, Wonho; Yang, Hyundae; Park, Hyunsub

    2015-01-01

    An exact classification of different gait phases is essential to enable the control of exoskeleton robots and detect the intentions of users. We propose a gait phase classification method based on neural networks using sensor signals from lower limb exoskeleton robots. In such robots, foot sensors with force sensing registers are commonly used to classify gait phases. We describe classifiers that use the orientation of each lower limb segment and the angular velocities of the joints to output the current gait phase. Experiments to obtain the input signals and desired outputs for the learning and validation process are conducted, and two neural network methods (a multilayer perceptron and nonlinear autoregressive with external inputs (NARX)) are used to develop an optimal classifier. Offline and online evaluations using four criteria are used to compare the performance of the classifiers. The proposed NARX-based method exhibits sufficiently good performance to replace foot sensors as a means of classifying gait phases. PMID:26528986

  13. Evidence-based guideline summary: Diagnosis and treatment of limb-girdle and distal dystrophies

    PubMed Central

    Narayanaswami, Pushpa; Weiss, Michael; Selcen, Duygu; David, William; Raynor, Elizabeth; Carter, Gregory; Wicklund, Matthew; Barohn, Richard J.; Ensrud, Erik; Griggs, Robert C.; Gronseth, Gary; Amato, Anthony A.

    2014-01-01

    Objective: To review the current evidence and make practice recommendations regarding the diagnosis and treatment of limb-girdle muscular dystrophies (LGMDs). Methods: Systematic review and practice recommendation development using the American Academy of Neurology guideline development process. Results: Most LGMDs are rare, with estimated prevalences ranging from 0.07 per 100,000 to 0.43 per 100,000. The frequency of some muscular dystrophies varies based on the ethnic background of the population studied. Some LGMD subtypes have distinguishing features, including pattern of muscle involvement, cardiac abnormalities, extramuscular involvement, and muscle biopsy findings. The few published therapeutic trials were not designed to establish clinical efficacy of any treatment. Principal recommendations: For patients with suspected muscular dystrophy, clinicians should use a clinical approach to guide genetic diagnosis based on clinical phenotype, inheritance pattern, and associated manifestations (Level B). Clinicians should refer newly diagnosed patients with an LGMD subtype and high risk of cardiac complications for cardiology evaluation even if they are asymptomatic from a cardiac standpoint (Level B). In patients with LGMD with a known high risk of respiratory failure, clinicians should obtain periodic pulmonary function testing (Level B). Clinicians should refer patients with muscular dystrophy to a clinic that has access to multiple specialties designed specifically to care for patients with neuromuscular disorders (Level B). Clinicians should not offer patients with LGMD gene therapy, myoblast transplantation, neutralizing antibody to myostatin, or growth hormone outside of a research study designed to determine efficacy and safety of the treatment (Level R). Detailed results and recommendations are available on the Neurology® Web site at Neurology.org. PMID:25313375

  14. Enhanced crosslimb transfer of force-field learning for dynamics that are identical in extrinsic and joint-based coordinates for both limbs

    PubMed Central

    de Rugy, Aymar; Howard, Ian S.; Ingram, James N.; Wolpert, Daniel M.

    2015-01-01

    Humans are able to adapt their motor commands to make accurate movements in novel sensorimotor environments, such as when wielding tools that alter limb dynamics. However, it is unclear to what extent sensorimotor representations, obtained through experience with one limb, are available to the opposite, untrained limb and in which form they are available. Here, we compared crosslimb transfer of force-field compensation after participants adapted to a velocity-dependent curl field, oriented either in the sagittal or the transverse plane. Due to the mirror symmetry of the limbs, the force field had identical effects for both limbs in joint and extrinsic coordinates in the sagittal plane but conflicting joint-based effects in the transverse plane. The degree of force-field compensation exhibited by the opposite arm in probe trials immediately after initial learning was significantly greater after sagittal (26 ± 5%) than transverse plane adaptation (9 ± 4%; P < 0.001), irrespective of whether participants learned initially with the left or the right arm or via abrupt or gradual exposure to the force field. Thus transfer was impaired when the orientation of imposed dynamics conflicted in intrinsic coordinates for the two limbs. The data reveal that neural representations of novel dynamics are only partially available to the opposite limb, since transfer is incomplete even when force-field perturbation is spatially compatible for the two limbs, according to both intrinsic and extrinsic coordinates. PMID:26581867

  15. Scanning-fiber-based imaging method for tissue engineering

    NASA Astrophysics Data System (ADS)

    Hofmann, Matthias C.; Whited, Bryce M.; Mitchell, Josh; Vogt, William C.; Criswell, Tracy; Rylander, Christopher; Rylander, Marissa Nichole; Soker, Shay; Wang, Ge; Xu, Yong

    2012-06-01

    A scanning-fiber-based method developed for imaging bioengineered tissue constructs such as synthetic carotid arteries is reported. Our approach is based on directly embedding one or more hollow-core silica fibers within the tissue scaffold to function as micro-imaging channels (MIC). The imaging process is carried out by translating and rotating an angle-polished fiber micro-mirror within the MIC to scan excitation light across the tissue scaffold. The locally emitted fluorescent signals are captured using an electron multiplying CCD camera and then mapped into fluorophore distributions according to fiber micro-mirror positions. Using an optical phantom composed of fluorescent microspheres, tissue scaffolds, and porcine skin, we demonstrated single-cell-level imaging resolution (20 to 30 μm) at an imaging depth that exceeds the photon transport mean free path by one order of magnitude. This result suggests that the imaging depth is no longer constrained by photon scattering, but rather by the requirement that the fluorophore signal overcomes the background ``noise'' generated by processes such as scaffold autofluorescence. Finally, we demonstrated the compatibility of our imaging method with tissue engineering by visualizing endothelial cells labeled with green fluorescent protein through a ~500 μm thick and highly scattering electrospun scaffold.

  16. Scanning-fiber-based imaging method for tissue engineering

    PubMed Central

    Hofmann, Matthias C.; Whited, Bryce M.; Mitchell, Josh; Vogt, William C.; Criswell, Tracy; Rylander, Christopher; Rylander, Marissa Nichole; Soker, Shay; Wang, Ge

    2012-01-01

    Abstract A scanning-fiber-based method developed for imaging bioengineered tissue constructs such as synthetic carotid arteries is reported. Our approach is based on directly embedding one or more hollow-core silica fibers within the tissue scaffold to function as micro-imaging channels (MIC). The imaging process is carried out by translating and rotating an angle-polished fiber micro-mirror within the MIC to scan excitation light across the tissue scaffold. The locally emitted fluorescent signals are captured using an electron multiplying CCD camera and then mapped into fluorophore distributions according to fiber micro-mirror positions. Using an optical phantom composed of fluorescent microspheres, tissue scaffolds, and porcine skin, we demonstrated single-cell-level imaging resolution (20 to 30 μm) at an imaging depth that exceeds the photon transport mean free path by one order of magnitude. This result suggests that the imaging depth is no longer constrained by photon scattering, but rather by the requirement that the fluorophore signal overcomes the background “noise” generated by processes such as scaffold autofluorescence. Finally, we demonstrated the compatibility of our imaging method with tissue engineering by visualizing endothelial cells labeled with green fluorescent protein through a ∼500  μm thick and highly scattering electrospun scaffold. PMID:22734766

  17. Ultramicrosensors based on transition metal hexacyanoferrates for scanning electrochemical microscopy.

    PubMed

    Komkova, Maria A; Holzinger, Angelika; Hartmann, Andreas; Khokhlov, Alexei R; Kranz, Christine; Karyakin, Arkady A; Voronin, Oleg G

    2013-01-01

    We report here a way for improving the stability of ultramicroelectrodes (UME) based on hexacyanoferrate-modified metals for the detection of hydrogen peroxide. The most stable sensors were obtained by electrochemical deposition of six layers of hexacyanoferrates (HCF), more specifically, an alternating pattern of three layers of Prussian Blue and three layers of Ni-HCF. The microelectrodes modified with mixed layers were continuously monitored in 1 mM hydrogen peroxide and proved to be stable for more than 5 h under these conditions. The mixed layer microelectrodes exhibited a stability which is five times as high as the stability of conventional Prussian Blue-modified UMEs. The sensitivity of the mixed layer sensor was 0.32 A·M(-1)·cm(-2), and the detection limit was 10 µM. The mixed layer-based UMEs were used as sensors in scanning electrochemical microscopy (SECM) experiments for imaging of hydrogen peroxide evolution. PMID:24205459

  18. 3D range scan enhancement using image-based methods

    NASA Astrophysics Data System (ADS)

    Herbort, Steffen; Gerken, Britta; Schugk, Daniel; Wöhler, Christian

    2013-10-01

    This paper addresses the problem of 3D surface scan refinement, which is desirable due to noise, outliers, and missing measurements being present in the 3D surfaces obtained with a laser scanner. We present a novel algorithm for the fusion of absolute laser scanner depth profiles and photometrically estimated surface normal data, which yields a noise-reduced and highly detailed depth profile with large scale shape robustness. In contrast to other approaches published in the literature, the presented algorithm (1) regards non-Lambertian surfaces, (2) simultaneously computes surface reflectance (i.e. BRDF) parameters required for 3D reconstruction, (3) models pixelwise incident light and viewing directions, and (4) accounts for interreflections. The algorithm as such relies on the minimization of a three-component error term, which penalizes intensity deviations, integrability deviations, and deviations from the known large-scale surface shape. The solution of the error minimization is obtained iteratively based on a calculus of variations. BRDF parameters are estimated by initially reducing and then iteratively refining the optical resolution, which provides the required robust data basis. The 3D reconstruction of concave surface regions affected by interreflections is improved by compensating global illumination in the image data. The algorithm is evaluated based on eight objects with varying albedos and reflectance behaviors (diffuse, specular, metallic). The qualitative evaluation shows a removal of outliers and a strong reduction of noise, while the large scale shape is preserved. Fine surface details Which are previously not contained in the surface scans, are incorporated through using image data. The algorithm is evaluated with respect to its absolute accuracy using two caliper objects of known shape, and based on synthetically generated data. The beneficial effect of interreflection compensation on the reconstruction accuracy is evaluated quantitatively in a

  19. Control of a pneumatic power active lower-limb orthosis with filter-based iterative learning control

    NASA Astrophysics Data System (ADS)

    Huang, Chia-En; Chen, Jian-Shiang

    2014-05-01

    A filter-based iterative learning control (FILC) scheme is developed in this paper, which consists in a proportional-derivative (PD) feedback controller and a feedforward filter. Moreover, based on two-dimensional system theory, the stability of the FILC system is proven. The design criteria for a wavelet transform filter (WTF) - chosen as the feedforward filter - and the PD feedback controller are also given. Finally, using a pneumatic power active lower-limb orthosis (PPALO) as the controlled plant, the wavelet-based iterative learning control (WILC) implementation and the orchestration of a trajectory tracking control simulation are given in detail and the overall tracking performance is validated.

  20. Cooperative Environment Scans Based on a Multi-Robot System

    PubMed Central

    Kwon, Ji-Wook

    2015-01-01

    This paper proposes a cooperative environment scan system (CESS) using multiple robots, where each robot has low-cost range finders and low processing power. To organize and maintain the CESS, a base robot monitors the positions of the child robots, controls them, and builds a map of the unknown environment, while the child robots with low performance range finders provide obstacle information. Even though each child robot provides approximated and limited information of the obstacles, CESS replaces the single LRF, which has a high cost, because much of the information is acquired and accumulated by a number of the child robots. Moreover, the proposed CESS extends the measurement boundaries and detects obstacles hidden behind others. To show the performance of the proposed system and compare this with the numerical models of the commercialized 2D and 3D laser scanners, simulation results are included. PMID:25789491

  1. Planar metamaterial-based beam-scanning broadband microwave antenna

    NASA Astrophysics Data System (ADS)

    Dhouibi, Abdallah; Burokur, Shah Nawaz; de Lustrac, André

    2014-05-01

    The broadband directive emission from the use of waveguided metamaterials is numerically and experimentally reported. The metamaterials, which are composed of non-resonant circular complementary closed ring structures printed on a dielectric substrate, are designed to obey the refractive index of a Luneburg lens. An arc array of planar radiating slot antennas placed at the periphery of the lens is used as wave launchers. A prototype of the lens associated with the feed structures has been fabricated using standard lithography techniques. To experimentally demonstrate the broadband focusing properties and directive emissions, far-field radiation patterns have been measured. Furthermore, this metamaterial-based lens can be used to achieve beam-scanning with a coverage of up to 120 °. Far-field measurements agree qualitatively with calculated near-field distributions.

  2. Surface skeleton generation based on 360-degree profile scan

    NASA Astrophysics Data System (ADS)

    Chen, Lujie; Sass, Lawrence; Sung, Woong Ki; Noel, Vernelle

    2013-05-01

    A rapid prototyping method is invented, which works on a specific data structure produced by an optical metrology technique: 360-degree surface profile scanning. A computer algorithm takes an object profile data, restructure the format, generate horizontal and vertical ribs, lay out the ribs on a 2D canvas and output the geometries to a file format compatible with laser cutters. A laser cutting machine is subsequently used to cut all the ribs from sheet materials. Then, the ribs are manually assembled based on computer-generated assembly codes. Through this process, the original object's 3D surface can be prototyped rapidly at an arbitrary scale, which may well exceed the working dimension of the laser cutter.

  3. Planar metamaterial-based beam-scanning broadband microwave antenna

    SciTech Connect

    Dhouibi, Abdallah; Burokur, Shah Nawaz Lustrac, André de

    2014-05-21

    The broadband directive emission from the use of waveguided metamaterials is numerically and experimentally reported. The metamaterials, which are composed of non-resonant circular complementary closed ring structures printed on a dielectric substrate, are designed to obey the refractive index of a Luneburg lens. An arc array of planar radiating slot antennas placed at the periphery of the lens is used as wave launchers. A prototype of the lens associated with the feed structures has been fabricated using standard lithography techniques. To experimentally demonstrate the broadband focusing properties and directive emissions, far-field radiation patterns have been measured. Furthermore, this metamaterial-based lens can be used to achieve beam-scanning with a coverage of up to 120 °. Far-field measurements agree qualitatively with calculated near-field distributions.

  4. Three phase bone scan interpretation based upon vascular endothelial response

    PubMed Central

    Kumar, Kush

    2015-01-01

    Objectives: A new method of interpretation of Three Phase Bone Scan (TPBS) scan based upon the normal physiological vascular endothelial related response. Materials and Methods: Fifty cases of TPBS were evaluated. Thirteen were normal. In remaining 37 positive studies, 20 showed localized hyperemic response. All localized hyperemic responses except one with vascular endothelial dysfunction were without infection (95.0%). Infection could be ruled out in absence of generalized massive flow and pool response. All 17 cases with generalized massive hyperemic response had infection, consistent with infection or CRPS/RSD. Micro-bacterial or histological confirmation of infection was obtained in 11 cases. All 11 cases with confirmed infection showed generalized massive hyperemic response (100.0%). Two were CRPS/RSD and 2 cases were of cellulitis (100.0%). Among remaining 2, one refused surgery and other was lost to follow-up. Additionally, 20 published cases in the literature of osteomyelitis were also analyzed. Nineteen cases of bone and joint infection, (osteomyelitis/arthritis/cellulitis) except one with endothelial dysfunction showed generalized massive increased flow and pool response (95.0%). All published cases of osteomyelitis in the literature showed generalized massive hyperemic response (100.0%). Results: The data clearly indicated that 100% of the cases of bone infection (osteomyelitis/arthritis/cellulitis) and cases of CRPS/RSD showed generalized massive flow and pool pattern. Infection could be ruled out in absence of generalized massive flow and pool response. All 100% published cases of osteomyelitis in the literature showed positive vascular endothelial response. Conclusion: By incorporating the concept of vascular endothelial related response causing massive vasodilatation in infection, the interpretation of the TPBS can be more précised as it is based upon the normal physiology. Larger studies are recommended. PMID:25829726

  5. Development of exoskeletal robotic limbs for a rat controlled by neural signals based on a vehicular neuro-robotic platform RatCar.

    PubMed

    Fukayama, Osamu; Otsuka, Hiroshi; Hashimoto, Ryuta; Suzuki, Takafumi; Mabuchi, Kunihiko

    2012-01-01

    A pair of exoskeletal limbs for a rat has been developed based on a vehicular Brain-Machine Interface "Rat-Car". The "RatCar" is a whole-body motor prosthesis system for a rat developed by the authors, estimating locomotion velocity according to neural signals pattern to move the rat body by the vehicle instead of its original limbs. In this paper, exoskeletal limbs have displaced the wheels for more natural modality of body control. The system was tested by applying peripheral nerve signals from a behaving rat. PMID:23366238

  6. Spectroscopic scanning tunneling microscopy insights into Fe-based superconductors

    NASA Astrophysics Data System (ADS)

    Hoffman, Jennifer E.

    2011-12-01

    In the first three years since the discovery of Fe-based high Tc superconductors, scanning tunneling microscopy (STM) and spectroscopy have shed light on three important questions. First, STM has demonstrated the complexity of the pairing symmetry in Fe-based materials. Phase-sensitive quasiparticle interference (QPI) imaging and low temperature spectroscopy have shown that the pairing order parameter varies from nodal to nodeless s± within a single family, FeTe1-xSex. Second, STM has imaged C4 → C2 symmetry breaking in the electronic states of both parent and superconducting materials. As a local probe, STM is in a strong position to understand the interactions between these broken symmetry states and superconductivity. Finally, STM has been used to image the vortex state, giving insights into the technical problem of vortex pinning, and the fundamental problem of the competing states introduced when superconductivity is locally quenched by a magnetic field. Here we give a pedagogical introduction to STM and QPI imaging, discuss the specific challenges associated with extracting bulk properties from the study of surfaces, and report on progress made in understanding Fe-based superconductors using STM techniques.

  7. Action observation for upper limb function after stroke: evidence-based review of randomized controlled trials

    PubMed Central

    Kim, KyeongMi

    2015-01-01

    [Purpose] The purpose of this study was to suggest evidenced information about action observation to improve upper limb function after stroke. [Methods] A systematic review of randomized controlled trials involving adults aged 18 years or over and including descriptions of action observation for improving upper limb function was undertaken. Electronic databases were searched, including MEDLINE, CINAHL, and PEDro (the Physiotherapy Evidence Database), for articles published between 2000 to 2014. Following completion of the searches, two reviewers independently assessed the trials and extracted data using a data extraction form. The same two reviewers independently documented the methodological quality of the trials by using the PEDro scale. [Results] Five randomized controlled trials were ultimately included in this review, and four of them (80%) reported statistically significant effects for motor recovery of upper limb using action observation intervention in between groups. [Conclusion] This review of the literature presents evidence attesting to the benefits conferred on stroke patints resulting from participation in an action observation intervention. The body of literature in this field is growing steadily. Further work needs to be done to evaluate the evidence for different conditions after stroke and different duration of intervention. PMID:26644700

  8. Optimal alignment of mirror based pentaprisms for scanning deflectometric devices

    SciTech Connect

    Barber, Samuel K.; Geckeler, Ralf D.; Yashchuk, Valeriy V.; Gubarev, Mikhail V.; Buchheim, Jana; Siewert, Frank; Zeschke, Thomas

    2011-03-04

    In the recent work [Proc. of SPIE 7801, 7801-2/1-12 (2010), Opt. Eng. 50(5) (2011), in press], we have reported on improvement of the Developmental Long Trace Profiler (DLTP), a slope measuring profiler available at the Advanced Light Source Optical Metrology Laboratory, achieved by replacing the bulk pentaprism with a mirror based pentaprism (MBPP). An original experimental procedure for optimal mutual alignment of the MBPP mirrors has been suggested and verified with numerical ray tracing simulations. It has been experimentally shown that the optimally aligned MBPP allows the elimination of systematic errors introduced by inhomogeneity of the optical material and fabrication imperfections of the bulk pentaprism. In the present article, we provide the analytical derivation and verification of easily executed optimal alignment algorithms for two different designs of mirror based pentaprisms. We also provide an analytical description for the mechanism for reduction of the systematic errors introduced by a typical high quality bulk pentaprism. It is also shown that residual misalignments of an MBPP introduce entirely negligible systematic errors in surface slope measurements with scanning deflectometric devices.

  9. Thermal Wave-Based Scanning Probe Microscopy and Its Applications

    NASA Astrophysics Data System (ADS)

    Pelzl, J.; Chirtoc, M.; Meckenstock, R.

    2013-09-01

    In the last two decades scanning thermal microscopes (SThM) with DC- and AC-heating have been developed offering resolutions down to the nanometer scale. The SThM is based on an atomic force microscope (AFM) that is equipped with a temperature sensitive nanoprobe. Most frequently a tip with a temperature-dependent electrical resistor is used which can be operated as a thermometer or as a heater. The lateral resolution of about 100 nm is determined by the tip radius. Alternatively, if the thermoelastic response is detected by a smaller AFM probe, a spatial resolution of about 10 nm can be attained. Thermal wave-based SThM-techniques (AC-SThM) are used (i) to control the thermal management of electronic devices and to image thermal parameters with submicron resolution and (ii) to study resonance absorption processes of optical, infrared, and microwave radiation on the nanometer scale. Examples presented comprise the thermal imaging of hot spots in high power and in-plane-gate transistors and local studies of the temperature dependence of the thermal conductivity of nano-structured NiTi shape memory alloys by the method. The use of the SThM as a tool for a spatially resolved spectroscopy is demonstrated by locally resolved ferromagnetic resonance measurements in thin iron and nickel films deposited on various substrates.

  10. The development of a segment-based musculoskeletal model of the lower limb: introducing FreeBody.

    PubMed

    Cleather, Daniel J; Bull, Anthony M J

    2015-06-01

    Traditional approaches to the biomechanical analysis of movement are joint-based; that is the mechanics of the body are described in terms of the forces and moments acting at the joints, and that muscular forces are considered to create moments about the joints. We have recently shown that segment-based approaches, where the mechanics of the body are described by considering the effect of the muscle, ligament and joint contact forces on the segments themselves, can also prove insightful. We have also previously described a simultaneous, optimization-based, musculoskeletal model of the lower limb. However, this prior model incorporates both joint- and segment-based assumptions. The purpose of this study was therefore to develop an entirely segment-based model of the lower limb and to compare its performance to our previous work. The segment-based model was used to estimate the muscle forces found during vertical jumping, which were in turn compared with the muscular activations that have been found in vertical jumping, by using a Geers' metric to quantify the magnitude and phase errors. The segment-based model was shown to have a similar ability to estimate muscle forces as a model based upon our previous work. In the future, we will evaluate the ability of the segment-based model to be used to provide results with clinical relevance, and compare its performance to joint-based approaches. The segment-based model described in this article is publicly available as a GUI-based Matlab® application and in the original source code (at www.msksoftware.org.uk). PMID:26543569

  11. The development of a segment-based musculoskeletal model of the lower limb: introducing FreeBody

    PubMed Central

    Cleather, Daniel J.; Bull, Anthony M. J.

    2015-01-01

    Traditional approaches to the biomechanical analysis of movement are joint-based; that is the mechanics of the body are described in terms of the forces and moments acting at the joints, and that muscular forces are considered to create moments about the joints. We have recently shown that segment-based approaches, where the mechanics of the body are described by considering the effect of the muscle, ligament and joint contact forces on the segments themselves, can also prove insightful. We have also previously described a simultaneous, optimization-based, musculoskeletal model of the lower limb. However, this prior model incorporates both joint- and segment-based assumptions. The purpose of this study was therefore to develop an entirely segment-based model of the lower limb and to compare its performance to our previous work. The segment-based model was used to estimate the muscle forces found during vertical jumping, which were in turn compared with the muscular activations that have been found in vertical jumping, by using a Geers' metric to quantify the magnitude and phase errors. The segment-based model was shown to have a similar ability to estimate muscle forces as a model based upon our previous work. In the future, we will evaluate the ability of the segment-based model to be used to provide results with clinical relevance, and compare its performance to joint-based approaches. The segment-based model described in this article is publicly available as a GUI-based Matlab® application and in the original source code (at www.msksoftware.org.uk). PMID:26543569

  12. MEMS segmented-based adaptive optics scanning laser ophthalmoscope

    PubMed Central

    Manzanera, Silvestre; Helmbrecht, Michael A.; Kempf, Carl J.; Roorda, Austin

    2011-01-01

    The performance of a MEMS (micro-electro-mechanical-system) segmented deformable mirror was evaluated in an adaptive optics (AO) scanning laser ophthalmoscope. The tested AO mirror (Iris AO, Inc, Berkeley, CA) is composed of 37 hexagonal segments that allow piston/tip/tilt motion up to 5 μm stroke and ±5 mrad angle over a 3.5 mm optical aperture. The control system that implements the closed-loop operation employs a 1:1 matched 37-lenslet Shack-Hartmann wavefront sensor whose measurements are used to apply modal corrections to the deformable mirror. After a preliminary evaluation of the AO mirror optical performance, retinal images from 4 normal subjects over a 0.9°x0.9° field size were acquired through a 6.4 mm ocular pupil, showing resolved retinal features at the cellular level. Cone photoreceptors were observed as close as 0.25 degrees from the foveal center. In general, the quality of these images is comparable to that obtained using deformable mirrors based on different technologies. PMID:21559132

  13. Dissecting enzyme function with microfluidic-based deep mutational scanning

    PubMed Central

    Romero, Philip A.; Tran, Tuan M.; Abate, Adam R.

    2015-01-01

    Natural enzymes are incredibly proficient catalysts, but engineering them to have new or improved functions is challenging due to the complexity of how an enzyme’s sequence relates to its biochemical properties. Here, we present an ultrahigh-throughput method for mapping enzyme sequence–function relationships that combines droplet microfluidic screening with next-generation DNA sequencing. We apply our method to map the activity of millions of glycosidase sequence variants. Microfluidic-based deep mutational scanning provides a comprehensive and unbiased view of the enzyme function landscape. The mapping displays expected patterns of mutational tolerance and a strong correspondence to sequence variation within the enzyme family, but also reveals previously unreported sites that are crucial for glycosidase function. We modified the screening protocol to include a high-temperature incubation step, and the resulting thermotolerance landscape allowed the discovery of mutations that enhance enzyme thermostability. Droplet microfluidics provides a general platform for enzyme screening that, when combined with DNA-sequencing technologies, enables high-throughput mapping of enzyme sequence space. PMID:26040002

  14. Recognition Method of Limb Motor Imagery EEG Signals Based on Integrated Back-propagation Neural Network

    PubMed Central

    Li, Mingyang; Chen, Wanzhong; Cui, Bingyi; Tian, Yantao

    2015-01-01

    In this paper, in order to solve the existing problems of the low recognition rate and poor real-time performance in limb motor imagery, the integrated back-propagation neural network (IBPNN) was applied to the pattern recognition research of motor imagery EEG signals (imagining left-hand movement, imagining right-hand movement and imagining no movement). According to the motor imagery EEG data categories to be recognized, the IBPNN was designed to consist of 3 single three-layer back-propagation neural networks (BPNN), and every single neural network was dedicated to recognizing one kind of motor imagery. It simplified the complicated classification problems into three mutually independent two-class classifications by the IBPNN. The parallel computing characteristic of IBPNN not only improved the generation ability for network, but also shortened the operation time. The experimental results showed that, while comparing the single BPNN and Elman neural network, IBPNN was more competent in recognizing limb motor imagery EEG signals. Also among these three networks, IBPNN had the least number of iterations, the shortest operation time and the best consistency of actual output and expected output, and had lifted the success recognition rate above 97 percent while other single network is around 93 percent. PMID:25893019

  15. A Serious Game for Upper Limb Stroke Rehabilitation Using Biofeedback and Mirror-Neurons Based Training.

    PubMed

    Cargnin, Diego João; Cordeiro d'Ornellas, Marcos; Cervi Prado, Ana Lúcia

    2015-01-01

    Upper limb stroke rehabilitation requires early, intensive and repetitive practice to be effective. Consequently, it is often difficult to keep patients committed to their rehabilitation regimen. In addition to direct measures of rehabilitation achievable through targeted assessments, other factors can indirectly lead to rehabilitation. Current levels of integration between commodity graphics software, hardware, and body-tracking devices have provided a reliable tool to build what are referred to as serious games, focusing on the rehabilitation paradigm. More specifically, serious games can captivate and engage players for a specific purpose such as developing new knowledge or skills. This paper discusses a serious game application with a focus on upper limb rehabilitation in patients with hemiplegia or hemiparesis. The game makes use of biofeedback and mirror-neurons to enhance the patient's engagement. Results from the application of a quantitative self-report instrument to assess in-game engagement suggest that the serious game is a viable instructional approach rather than an entertaining novelty and, furthermore, demonstrates the future potential for dual action therapy-focused games. PMID:26262069

  16. Perforator Based Propeller Flaps in Limb Reconstructive Surgery: Clinical Application and Literature Review

    PubMed Central

    Artiaco, Stefano; Bianchi, Pasquale; Boux, Elena; Tos, Pierluigi

    2014-01-01

    The reconstruction of loss of substance due to trauma or oncological excision may have relevant functional and aesthetic implications. We report our experience in twenty-one cases of propeller flaps for the treatment of loss of substance of the upper and lower limbs. The etiology of defect was tumor excision in nine cases, trauma in seven cases, surgical wound complications in four cases, and chronic osteomyelitis in one case. Clinical results were favorable in most cases and eighteen flaps survived. We observed an overall complication rate of 33% with four cases of superficial epidermolysis that spontaneously healed and three cases of partial flap loss ranging from 10 to 50% that required surgical revision by means of skin graft (two cases) or ALT free flap (one case). Propeller flap harvesting requires great care and experience, and potential complications may occur even in expert hands. When indicated by the characteristic of the defect, these flaps can be a useful surgical option for the treatment of loss of substance of upper and lower limbs. PMID:25250327

  17. Perforator based propeller flaps in limb reconstructive surgery: clinical application and literature review.

    PubMed

    Artiaco, Stefano; Battiston, Bruno; Colzani, Giulia; Bianchi, Pasquale; Scaravilli, Gabriele; Boux, Elena; Tos, Pierluigi

    2014-01-01

    The reconstruction of loss of substance due to trauma or oncological excision may have relevant functional and aesthetic implications. We report our experience in twenty-one cases of propeller flaps for the treatment of loss of substance of the upper and lower limbs. The etiology of defect was tumor excision in nine cases, trauma in seven cases, surgical wound complications in four cases, and chronic osteomyelitis in one case. Clinical results were favorable in most cases and eighteen flaps survived. We observed an overall complication rate of 33% with four cases of superficial epidermolysis that spontaneously healed and three cases of partial flap loss ranging from 10 to 50% that required surgical revision by means of skin graft (two cases) or ALT free flap (one case). Propeller flap harvesting requires great care and experience, and potential complications may occur even in expert hands. When indicated by the characteristic of the defect, these flaps can be a useful surgical option for the treatment of loss of substance of upper and lower limbs. PMID:25250327

  18. Fluorescence detection in capillary arrays based on galvanometer step scanning.

    PubMed

    Xue, G; Yeung, E S

    2001-10-01

    A computer-controlled galvanometer scanner is adapted for scanning a focused laser beam across a 96-capillary array for laser-induced fluorescence detection. The signal at a single photomultiplier tube is temporally sorted to distinguish among the capillaries. The limit of detection for fluoresceins is 3 x 10(-11) M (S/N = 3) for 5 mW of total laser power scanned at 4 Hz. The observed cross-talk among capillaries is 0.2%. Advantages include the efficient utilization of light due to the high duty-cycle of step scan, good detection performance due to the reduction of stray light, ruggedness due to the small mass of the galvanometer mirror, low cost due to the simplicity of components, and flexibility due to the independent paths for excitation and emission. PMID:11669531

  19. Phantom limb pain after lower limb trauma: origins and treatments.

    PubMed

    Foell, Jens; Bekrater-Bodmann, Robin; Flor, Herta; Cole, Jonathan

    2011-12-01

    Phantom sensations, that is, sensations perceived in a body part that has been lost, are a common consequence of accidental or clinical extremity amputations. Most amputation patients report a continuing presence of the limb, with some describing additional sensations such as numbness, tickling, or cramping of the phantom limb. The type, frequency, and stability of these phantom sensations can vary immensely. The phenomenon of painful phantom sensations, that is, phantom limb pain, presents a challenge for practitioners and researchers and is often detrimental to the patient's quality of life. In addition to the use of conventional therapies for chronic pain disorders, recent years have seen the development of novel treatments for phantom limb pain, based on an increasing body of research on neurophysiological changes after amputation. This article describes the current state of research in regard to the demographics, causal factors, and treatments of phantom limb pain. PMID:22184752

  20. Ta Keo Temple Reconstruction Based on Terrestrial Laser Scanning Technology

    NASA Astrophysics Data System (ADS)

    Xi, X.; Wang, C.; Wan, Y. P.; Khuon, K. N.

    2015-08-01

    Ta Keo temple is one of the very famous temple complex of Angkor Wat in northwestern Cambodia. It has been suffering massive collapse and other serious damages in recent years. Nowadays, Terrestrial Laser Scanning(TLS) technology is considered as a wellestablished resource for heritage documentation and protection (Lerma et al, 2008; Reshetyuk, 2009). This paper used TLS to reconstruct Ta Keo Temple. Firstly, we acquired 71 scanning stations of points cloud data with high density and high accuracy, and over one thousand images with high spatial resolution about the temple. Secondly, the raw points cloud data were denoised, reduced and managed efficiently, and registrated using an adjusted ICP algorithm. Thirdly, a triangulation method was used to model most objects. At last, we mapped the texture data into the digital model and a 3-D model of Ta Keo with high accuracy was achieved. The authors focus on large object reconstruction by TLS technology, and pay much attention to the scanning design, multi-station data and the whole project's data registration, and texture mapping and so on. The research result will be useful for Ta Keo restoration, reconstruction and protection. Also, it is a good reference source for large complex buildings reconstruction when using terrestrial laser scanning technology.

  1. Assessing the impact of upper limb disability following stroke: a qualitative enquiry using internet-based personal accounts of stroke survivors

    PubMed Central

    Poltawski, Leon; Allison, Rhoda; Briscoe, Simon; Freeman, Jennifer; Kilbride, Cherry; Neal, Debbie; Turton, Ailie J.; Dean, Sarah

    2016-01-01

    Abstract Purpose: Upper limb disability following stroke may have multiple effects on the individual. Existing assessment instruments tend to focus on impairment and function and may miss other changes that are personally important. This study aimed to identify personally significant impacts of upper limb disability following stroke. Methods: Accounts by stroke survivors, in the form of web-based diaries (blogs) and stories, were sought using a blog search engine and in stroke-related web-sites. Thematic analysis using the World Health Organisation’s International Classification of Functioning Disability and Health (ICF) was used to identify personal impacts of upper limb disability following stroke. Results: Ninety-nine sources from at least four countries were analysed. Many impacts were classifiable using the ICF, but a number of additional themes emerged, including emotional, cognitive and behavioural changes. Blogs and other web-based accounts were easily accessible and rich sources of data, although using them raised several methodological issues, including potential sample bias. Conclusions: A range of impacts was identified, some of which (such as use of information technology and alienation from the upper limb) are not addressed in current assessment instruments. They should be considered in post-stroke assessments. Blogs may help in the development of more comprehensive assessments.Implications for RehabilitationA comprehensive assessment of the upper limb following stroke should include the impact of upper limb problems on social participation, as well as associated emotional, cognitive and behavioural changes.Using personalised assessment instruments alongside standardised measures may help ensure that these broader domains are considered in discussions between clinicians and patients.Rehabilitation researchers should investigate whether and how these domains could be addressed and operationalised in standard upper limb assessment instruments. PMID

  2. SCAN-based hybrid and double-hybrid density functionals from models without fitted parameters.

    PubMed

    Hui, Kerwin; Chai, Jeng-Da

    2016-01-28

    By incorporating the nonempirical strongly constrained and appropriately normed (SCAN) semilocal density functional [J. Sun, A. Ruzsinszky, and J. P. Perdew, Phys. Rev. Lett. 115, 036402 (2015)] in the underlying expression of four existing hybrid and double-hybrid models, we propose one hybrid (SCAN0) and three double-hybrid (SCAN0-DH, SCAN-QIDH, and SCAN0-2) density functionals, which are free from any fitted parameters. The SCAN-based double-hybrid functionals consistently outperform their parent SCAN semilocal functional for self-interaction problems and noncovalent interactions. In particular, SCAN0-2, which includes about 79% of Hartree-Fock exchange and 50% of second-order Møller-Plesset correlation, is shown to be reliably accurate for a very diverse range of applications, such as thermochemistry, kinetics, noncovalent interactions, and self-interaction problems. PMID:26827209

  3. Microvascular quantification based on contour-scanning photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Yeh, Chenghung; Soetikno, Brian; Hu, Song; Maslov, Konstantin I.; Wang, Lihong V.

    2014-09-01

    Accurate quantification of microvasculature remains of interest in fundamental pathophysiological studies and clinical trials. Current photoacoustic microscopy can noninvasively quantify properties of the microvasculature, including vessel density and diameter, with a high spatial resolution. However, the depth range of focus (i.e., focal zone) of optical-resolution photoacoustic microscopy (OR-PAM) is often insufficient to encompass the depth variations of features of interest-such as blood vessels-due to uneven tissue surfaces. Thus, time-consuming image acquisitions at multiple different focal planes are required to maintain the region of interest in the focal zone. We have developed continuous three-dimensional motorized contour-scanning OR-PAM, which enables real-time adjustment of the focal plane to track the vessels' profile. We have experimentally demonstrated that contour scanning improves the signal-to-noise ratio of conventional OR-PAM by as much as 41% and shortens the image acquisition time by 3.2 times. Moreover, contour-scanning OR-PAM more accurately quantifies vessel density and diameter, and has been applied to studying tumors with uneven surfaces.

  4. Robust Sliding Mode Control Based on GA Optimization and CMAC Compensation for Lower Limb Exoskeleton

    PubMed Central

    Long, Yi; Du, Zhi-jiang; Wang, Wei-dong; Dong, Wei

    2016-01-01

    A lower limb assistive exoskeleton is designed to help operators walk or carry payloads. The exoskeleton is required to shadow human motion intent accurately and compliantly to prevent incoordination. If the user's intention is estimated accurately, a precise position control strategy will improve collaboration between the user and the exoskeleton. In this paper, a hybrid position control scheme, combining sliding mode control (SMC) with a cerebellar model articulation controller (CMAC) neural network, is proposed to control the exoskeleton to react appropriately to human motion intent. A genetic algorithm (GA) is utilized to determine the optimal sliding surface and the sliding control law to improve performance of SMC. The proposed control strategy (SMC_GA_CMAC) is compared with three other types of approaches, that is, conventional SMC without optimization, optimal SMC with GA (SMC_GA), and SMC with CMAC compensation (SMC_CMAC), all of which are employed to track the desired joint angular position which is deduced from Clinical Gait Analysis (CGA) data. Position tracking performance is investigated with cosimulation using ADAMS and MATLAB/SIMULINK in two cases, of which the first case is without disturbances while the second case is with a bounded disturbance. The cosimulation results show the effectiveness of the proposed control strategy which can be employed in similar exoskeleton systems. PMID:27069353

  5. Robust Sliding Mode Control Based on GA Optimization and CMAC Compensation for Lower Limb Exoskeleton.

    PubMed

    Long, Yi; Du, Zhi-Jiang; Wang, Wei-Dong; Dong, Wei

    2016-01-01

    A lower limb assistive exoskeleton is designed to help operators walk or carry payloads. The exoskeleton is required to shadow human motion intent accurately and compliantly to prevent incoordination. If the user's intention is estimated accurately, a precise position control strategy will improve collaboration between the user and the exoskeleton. In this paper, a hybrid position control scheme, combining sliding mode control (SMC) with a cerebellar model articulation controller (CMAC) neural network, is proposed to control the exoskeleton to react appropriately to human motion intent. A genetic algorithm (GA) is utilized to determine the optimal sliding surface and the sliding control law to improve performance of SMC. The proposed control strategy (SMC_GA_CMAC) is compared with three other types of approaches, that is, conventional SMC without optimization, optimal SMC with GA (SMC_GA), and SMC with CMAC compensation (SMC_CMAC), all of which are employed to track the desired joint angular position which is deduced from Clinical Gait Analysis (CGA) data. Position tracking performance is investigated with cosimulation using ADAMS and MATLAB/SIMULINK in two cases, of which the first case is without disturbances while the second case is with a bounded disturbance. The cosimulation results show the effectiveness of the proposed control strategy which can be employed in similar exoskeleton systems. PMID:27069353

  6. Stratospheric constituent distributions from balloon-based limb thermal emission measurements

    NASA Technical Reports Server (NTRS)

    Abbas, Mian M.; Kunde, Vigil G.

    1990-01-01

    This research task deals with an analysis of infrared thermal emission observations of the Earth's atmosphere for determination of trace constituent distributions. Infrared limb thermal emission spectra in the 700-2000 cm(exp -1) region were obtained with a liquid nitrogen cooled Michelson interferometer-spectrometer (SIRIS) on a balloon flight launched from Palestine, Texas, at nighttime on September 15-16, 1986. An important objective of this work is to obtain simultaneously measured vertical mixing ratio profiles of O3, H2O, N2O, NO2, N2O5, HNO3 and ClONO2 and compare with measurements made with a variety of techniques by other groups as well as with photochemical model calculations. A portion of the observed spectra obtained by SIRIS from the balloon flight on September 15-16, 1986, has been analyzed with a focus on calculation of the total nighttime odd nitrogen budget from the simultaneously measured profiles of important members of the NO(sub x) family. The measurements permit first direct determination of the nighttime total odd nitrogen concentrations NO(sub y) and the partitioning of the important elements of the NO(sub x) family.

  7. Pediatric limb differences and amputations.

    PubMed

    Le, Joan T; Scott-Wyard, Phoebe R

    2015-02-01

    Congenital limb differences are uncommon birth defects that may go undetected even with prenatal screening ultrasound scans and often go undetected until birth. For children with congenital limb differences, a diagnostic evaluation should be done to rule out syndromes involving other organ systems or known associations. The most common etiology of acquired amputation is trauma. Postamputation complications include pain and terminal bony overgrowth. A multidisciplinary approach to management with the child and family can lead to a successful, functional, and fulfilling life. PMID:25479783

  8. Tapping mode quartz crystal resonator based scanning force microscopy

    NASA Astrophysics Data System (ADS)

    Seo, Yongho; Jhe, Wonho

    2005-01-01

    We have built a high-speed, tapping mode scanning force microscope using a high frequency quartz crystal resonator. In our design, a cantilever tip was attached to the end of an optical fiber which was glued to a thickness shear mode, AT-cut quartz crystal resonator so as to vibrate in the longitudinal direction. This design allows the microscope to be operated in tapping mode with the flexibility of shear mode operation, which leads to an expected improvement of image quality. Furthermore, combining this geometry with an optical microscope leads to the possibility of commercial applications.

  9. The Society for Vascular Surgery Lower Extremity Threatened Limb Classification System: risk stratification based on wound, ischemia, and foot infection (WIfI).

    PubMed

    Mills, Joseph L; Conte, Michael S; Armstrong, David G; Pomposelli, Frank B; Schanzer, Andres; Sidawy, Anton N; Andros, George

    2014-01-01

    Critical limb ischemia, first defined in 1982, was intended to delineate a subgroup of patients with a threatened lower extremity primarily because of chronic ischemia. It was the intent of the original authors that patients with diabetes be excluded or analyzed separately. The Fontaine and Rutherford Systems have been used to classify risk of amputation and likelihood of benefit from revascularization by subcategorizing patients into two groups: ischemic rest pain and tissue loss. Due to demographic shifts over the last 40 years, especially a dramatic rise in the incidence of diabetes mellitus and rapidly expanding techniques of revascularization, it has become increasingly difficult to perform meaningful outcomes analysis for patients with threatened limbs using these existing classification systems. Particularly in patients with diabetes, limb threat is part of a broad disease spectrum. Perfusion is only one determinant of outcome; wound extent and the presence and severity of infection also greatly impact the threat to a limb. Therefore, the Society for Vascular Surgery Lower Extremity Guidelines Committee undertook the task of creating a new classification of the threatened lower extremity that reflects these important considerations. We term this new framework, the Society for Vascular Surgery Lower Extremity Threatened Limb Classification System. Risk stratification is based on three major factors that impact amputation risk and clinical management: Wound, Ischemia, and foot Infection (WIfI). The implementation of this classification system is intended to permit more meaningful analysis of outcomes for various forms of therapy in this challenging, but heterogeneous population. PMID:24126108

  10. Dopant profiling based on scanning electron and helium ion microscopy.

    PubMed

    Chee, Augustus K W; Boden, Stuart A

    2016-02-01

    In this paper, we evaluate and compare doping contrast generated inside the scanning electron microscope (SEM) and scanning helium ion microscope (SHIM). Specialised energy-filtering techniques are often required to produce strong doping contrast to map donor distributions using the secondary electron (SE) signal in the SEM. However, strong doping contrast can be obtained from n-type regions in the SHIM, even without energy-filtering. This SHIM technique is more sensitive than the SEM to donor density changes above its sensitivity threshold, i.e. of the order of 10(16) or 10(17)donorscm(-3) respectively on specimens with or without a p-n junction; its sensitivity limit is well above 2×10(17)acceptorscm(-3) on specimens with or without a p-n junction. Good correlation is found between the widths and slopes of experimentally measured doping contrast profiles of thin p-layers and the calculated widths and slopes of the potential energy distributions across these layers, at a depth of 1 to 3nm and 5 to 10nm below the surface in the SHIM and the SEM respectively. This is consistent with the mean escape depth of SEs in silicon being about 1.8nm and 7nm in the SHIM and SEM respectively, and we conclude that short escape depth, low energy SE signals are most suitable for donor profiling. PMID:26624515

  11. Home-based neurologic music therapy for upper limb rehabilitation with stroke patients at community rehabilitation stage—a feasibility study protocol

    PubMed Central

    Street, Alexander J.; Magee, Wendy L.; Odell-Miller, Helen; Bateman, Andrew; Fachner, Jorg C.

    2015-01-01

    Background: Impairment of upper limb function following stroke is more common than lower limb impairment and is also more resistant to treatment. Several lab-based studies with stroke patients have produced statistically significant gains in upper limb function when using musical instrument playing and techniques where rhythm acts as an external time-keeper for the priming and timing of upper limb movements. Methods: For this feasibility study a small sample size of 14 participants (3–60 months post stroke) has been determined through clinical discussion between the researcher and study host in order to test for management, feasibility and effects, before planning a larger trial determined through power analysis. A cross-over design with five repeated measures will be used, whereby participants will be randomized into either a treatment (n = 7) or wait list control (n = 7) group. Intervention will take place twice weekly over 6 weeks. The ARAT and 9HPT will be used to measure for quantitative gains in arm function and finger dexterity, pre/post treatment interviews will serve to investigate treatment compliance and tolerance. A lab based EEG case comparison study will be undertaken to explore audio-motor coupling, brain connectivity and neural reorganization with this intervention, as evidenced in similar studies. Discussion: Before evaluating the effectiveness of a home-based intervention in a larger scale study, it is important to assess whether implementation of the trial methodology is feasible. This study investigates the feasibility, efficacy and patient experience of a music therapy treatment protocol comprising a chart of 12 different instrumental exercises and variations, which aims at promoting measurable changes in upper limb function in hemiparetic stroke patients. The study proposes to examine several new aspects including home-based treatment and dosage, and will provide data on recruitment, adherence and variability of outcomes. PMID:26441586

  12. Electron tomography of HEK293T cells using scanning electron microscope-based scanning transmission electron microscopy.

    PubMed

    You, Yun-Wen; Chang, Hsun-Yun; Liao, Hua-Yang; Kao, Wei-Lun; Yen, Guo-Ji; Chang, Chi-Jen; Tsai, Meng-Hung; Shyue, Jing-Jong

    2012-10-01

    Based on a scanning electron microscope operated at 30 kV with a homemade specimen holder and a multiangle solid-state detector behind the sample, low-kV scanning transmission electron microscopy (STEM) is presented with subsequent electron tomography for three-dimensional (3D) volume structure. Because of the low acceleration voltage, the stronger electron-atom scattering leads to a stronger contrast in the resulting image than standard TEM, especially for light elements. Furthermore, the low-kV STEM yields less radiation damage to the specimen, hence the structure can be preserved. In this work, two-dimensional STEM images of a 1-μm-thick cell section with projection angles between ±50° were collected, and the 3D volume structure was reconstructed using the simultaneous iterative reconstructive technique algorithm with the TomoJ plugin for ImageJ, which are both public domain software. Furthermore, the cross-sectional structure was obtained with the Volume Viewer plugin in ImageJ. Although the tilting angle is constrained and limits the resulting structural resolution, slicing the reconstructed volume generated the depth profile of the thick specimen with sufficient resolution to examine cellular uptake of Au nanoparticles, and the final position of these nanoparticles inside the cell was imaged. PMID:23026379

  13. Assessment and prediction of inter-joint upper limb movement correlations based on kinematic analysis and statistical regression

    NASA Astrophysics Data System (ADS)

    Toth-Tascau, Mirela; Balanean, Flavia; Krepelka, Mircea

    2013-10-01

    Musculoskeletal impairment of the upper limb can cause difficulties in performing basic daily activities. Three dimensional motion analyses can provide valuable data of arm movement in order to precisely determine arm movement and inter-joint coordination. The purpose of this study was to develop a method to evaluate the degree of impairment based on the influence of shoulder movements in the amplitude of elbow flexion and extension based on the assumption that a lack of motion of the elbow joint will be compensated by an increased shoulder activity. In order to develop and validate a statistical model, one healthy young volunteer has been involved in the study. The activity of choice simulated blowing the nose, starting from a slight flexion of the elbow and raising the hand until the middle finger touches the tip of the nose and return to the start position. Inter-joint coordination between the elbow and shoulder movements showed significant correlation. Statistical regression was used to fit an equation model describing the influence of shoulder movements on the elbow mobility. The study provides a brief description of the kinematic analysis protocol and statistical models that may be useful in describing the relation between inter-joint movements of daily activities.

  14. Upper-limb stroke rehabilitation using electrode-array based functional electrical stimulation with sensing and control innovations.

    PubMed

    Kutlu, M; Freeman, C T; Hallewell, E; Hughes, A-M; Laila, D S

    2016-04-01

    Functional electrical stimulation (FES) has shown effectiveness in restoring upper-limb movement post-stroke when applied to assist participants' voluntary intention during repeated, motivating tasks. Recent clinical trials have used advanced controllers that precisely adjust FES to assist functional reach and grasp tasks with FES applied to three muscle groups, showing significant reduction in impairment. The system reported in this paper advances the state-of-the-art by: (1) integrating an FES electrode array on the forearm to assist complex hand and wrist gestures; (2) utilising non-contact depth cameras to accurately record the arm, hand and wrist position in 3D; and (3) employing an interactive touch table to present motivating virtual reality (VR) tasks. The system also uses iterative learning control (ILC), a model-based control strategy which adjusts the applied FES based on the tracking error recorded on previous task attempts. Feasibility of the system has been evaluated in experimental trials with 2 unimpaired participants and clinical trials with 4 hemiparetic, chronic stroke participants. The stroke participants attended 17, 1 hour training sessions in which they performed functional tasks, such as button pressing using the touch table and closing a drawer. Stroke participant results show that the joint angle error norm reduced by an average of 50.3% over 6 attempts at each task when assisted by FES. PMID:26947097

  15. Botulinum Toxin Type a Injection, Followed by Home-Based Functional Training for Upper Limb Hemiparesis after Stroke

    ERIC Educational Resources Information Center

    Takekawa, Toru; Kakuda, Wataru; Taguchi, Kensuke; Ishikawa, Atsushi; Sase, Yousuke; Abo, Masahiro

    2012-01-01

    Botulinum toxin type A (BoNT-A) has been reported to be an effective treatment for limb spasticity after stroke. However, the reduction in the spasticity after BoNT-A injection alone does not ensure an improvement in the active motor function of the affected limb. The aim of this study was to clarify the clinical effects of a BoNT-A injection,…

  16. The evaluation system of the 2-D scanning mirror based on CMOS sensor

    NASA Astrophysics Data System (ADS)

    Zeng, Gui-ying; Xie, Yuan; Chen, Jin-xing

    2010-10-01

    The high precision two-dimension scanning control technique is being developed for the next geosynchronous satellites FY-4 satellites which is using the three-axis stabilization stages. How to evaluate the point and scanning precision of the scanning mirror is one of the most important technologies. This paper describes the optoelectronic measure method based on CMOS sensors to evaluate the point and scanning precision of the scanning mirror in the laboratory, which is a 2-D dynamic angle measurement system. Some technologies, such as the sup-pixel orientation technology and the CMOS ROI technology, are used in the measurement system. The research shows that the angle measurement system based on IBIS-6600CMOS sensors can attain the 20°× 20° field of view, 2" accuracy, and 1Kframes/s speed. But the system is sensitive to the environment and it can only be worked in the laboratory.

  17. Family-based association tests for genomewide association scans.

    PubMed

    Chen, Wei-Min; Abecasis, Goncalo R

    2007-11-01

    With millions of single-nucleotide polymorphisms (SNPs) identified and characterized, genomewide association studies have begun to identify susceptibility genes for complex traits and diseases. These studies involve the characterization and analysis of very-high-resolution SNP genotype data for hundreds or thousands of individuals. We describe a computationally efficient approach to testing association between SNPs and quantitative phenotypes, which can be applied to whole-genome association scans. In addition to observed genotypes, our approach allows estimation of missing genotypes, resulting in substantial increases in power when genotyping resources are limited. We estimate missing genotypes probabilistically using the Lander-Green or Elston-Stewart algorithms and combine high-resolution SNP genotypes for a subset of individuals in each pedigree with sparser marker data for the remaining individuals. We show that power is increased whenever phenotype information for ungenotyped individuals is included in analyses and that high-density genotyping of just three carefully selected individuals in a nuclear family can recover >90% of the information available if every individual were genotyped, for a fraction of the cost and experimental effort. To aid in study design, we evaluate the power of strategies that genotype different subsets of individuals in each pedigree and make recommendations about which individuals should be genotyped at a high density. To illustrate our method, we performed genomewide association analysis for 27 gene-expression phenotypes in 3-generation families (Centre d'Etude du Polymorphisme Humain pedigrees), in which genotypes for ~860,000 SNPs in 90 grandparents and parents are complemented by genotypes for ~6,700 SNPs in a total of 168 individuals. In addition to increasing the evidence of association at 15 previously identified cis-acting associated alleles, our genotype-inference algorithm allowed us to identify associated alleles at 4

  18. iTRAQ-based proteomic analysis of adaptive response in the regenerating limb of the Cynops orientalis newt.

    PubMed

    Geng, Xiao-Fang; Guo, Jian-Lin; Zang, Xia-Yan; Sun, Jing-Yan; Li, Peng-Fei; Zhang, Fu-Chun; Xu, Cun-Shuan

    2015-01-01

    The newt has the powerful capacity to regenerate lost limbs following amputation, and represents an excellent model organism to study regenerative processes. However, the molecular basis of the adaptive response in the regenerating limb of the Chinese fire-bellied newt Cynops orientalis immediately after amputation remains unclear. To better understand the adaptive response immediately after limb amputation at the protein level, we used isobaric tags for relative and absolute quantitation (iTRAQ) coupled with LC-MS/MS methods to analyze changes in the proteome of the regenerating newt limb that occurred 2 h and 8 h after amputation. We identified 152 proteins with more than 1.5-fold change in expression compared to control. GO annotation analysis classified these proteins into several categories such as signaling, Ca(2+) binding and translocation, transcription and translation, immune response, cell death, cytoskeleton, metabolism, etc. Further ingenuity pathway analysis (IPA) showed that several signaling pathways were significantly changed at 2 h and 8 h after amputation, including EIF2 signaling, acute phase response signaling, tight junction signaling and calcium signaling, suggesting these pathways may be closely related to the adaptive response immediately after limb amputation. This work provides novel insights into understanding the molecular processes related to newt limb regeneration immediately after amputation, and a basis for further study of regenerative medicine. PMID:26864489

  19. Knowledge-Based Object Detection in Laser Scanning Point Clouds

    NASA Astrophysics Data System (ADS)

    Boochs, F.; Karmacharya, A.; Marbs, A.

    2012-07-01

    Object identification and object processing in 3D point clouds have always posed challenges in terms of effectiveness and efficiency. In practice, this process is highly dependent on human interpretation of the scene represented by the point cloud data, as well as the set of modeling tools available for use. Such modeling algorithms are data-driven and concentrate on specific features of the objects, being accessible to numerical models. We present an approach that brings the human expert knowledge about the scene, the objects inside, and their representation by the data and the behavior of algorithms to the machine. This "understanding" enables the machine to assist human interpretation of the scene inside the point cloud. Furthermore, it allows the machine to understand possibilities and limitations of algorithms and to take this into account within the processing chain. This not only assists the researchers in defining optimal processing steps, but also provides suggestions when certain changes or new details emerge from the point cloud. Our approach benefits from the advancement in knowledge technologies within the Semantic Web framework. This advancement has provided a strong base for applications based on knowledge management. In the article we will present and describe the knowledge technologies used for our approach such as Web Ontology Language (OWL), used for formulating the knowledge base and the Semantic Web Rule Language (SWRL) with 3D processing and topologic built-ins, aiming to combine geometrical analysis of 3D point clouds, and specialists' knowledge of the scene and algorithmic processing.

  20. The analysis of self-esteem based on patients` self-perception after Ilizarov limb lengthening treatment.

    PubMed

    Słomska, Beata; Pilarz, Eliza; Niedzielski, Kryspin Ryszard

    2012-01-01

    In the article there is shown the analysis of patients self-perception after the Ilizarov limb lenghening treatment due to inequality. 150 patients both sexes (78 girls and 72 boys) were tested between 1992 and 2003 in our center. The average age for girls at the time of follow-up was 19.5 years and 18.5 years for boys. In the survey there was used four point-scale SES by Irena Dzwokowska, Kinga Lachowicz-Tabaczek and Mariola Łagun which was based on Rosenberg work. The results were divided into two groups: low or high score. It was evaluated according to the table of standards which included people age and sex. Then the score was transformed into standard ten. For statistical calculations was used MicroSoft Excel spreadsheet. In the case of statistical studies was used Spss v.17.0. It was found that among survey respondents regardless of gender and age after the satisfactory completion of Ilizarov treatment patients gain a high level of self-assessment at 7 standard ten. The high self-esteem can predict the level of patients` comfort in many aspects of their lives. People with such a hight self-perception will experience more positive emotions and will be healthier and more active. PMID:23306286

  1. Based on line scan CCD print image detection system

    NASA Astrophysics Data System (ADS)

    Zhang, Lifeng; Xie, Kai; Li, Tong

    2015-12-01

    In this paper, a new method based on machine vision is proposed for the defects of the traditional manual inspection of the quality of printed matter. With the aid of on line array CCD camera for image acquisition, using stepper motor as a sampling of drive circuit. Through improvement of driving circuit, to achieve the different size or precision image acquisition. In the terms of image processing, the standard image registration algorithm then, because of the characteristics of CCD-image acquisition, rigid body transformation is usually used in the registration, so as to achieve the detection of printed image.

  2. Development of an optically scanned consultation-liaison data base.

    PubMed

    McKegney, F P; Schwartz, C E; O'Dowd, M A; Salamon, I; Kennedy, R

    1990-03-01

    Every clinical service must record certain data about its patient care activities. In low-volume services, such as Psychiatric Inpatient Services, with perhaps 20-30 admissions per month, and an average patient stay of 2-4 weeks, a large amount of data on each patient can be obtained during the contact time with the patient. On the other hand, very large-volume psychiatric services, such as Emergency and Consultation-Liaison (C-L) Services, may not need or be able to gather such a large amount of data on every patient seen. This article describes the development of a brief, optically scannable, and computerized minimal data base form for patients seen by a very large division of C-L Psychiatry. The system is feasible and easily auditable for completeness and reliability. This data base has already served many important functions beyond providing an administrative statistical summary of services rendered. It is presented as a model for the development of similarly efficient data collection methods for other high-volume psychiatric services. PMID:2307368

  3. Canoe game-based virtual reality training to improve trunk postural stability, balance, and upper limb motor function in subacute stroke patients: a randomized controlled pilot study.

    PubMed

    Lee, Myung-Mo; Shin, Doo-Chul; Song, Chang-Ho

    2016-07-01

    [Purpose] This study was aimed at investigating the preliminary therapeutic efficacy and usefulness of canoe game-based virtual reality training for stroke patients. [Subjects and Methods] Ten stroke patients were randomly assigned to an experimental group (EG; n=5) or a control group (CG; n=5). Patients in both groups participated in a conventional rehabilitation program, but those in the EG additionally participated in a 30-min canoe game-based virtual reality training program 3 days a week for 4 weeks. Therapeutic efficacy was assessed based on trunk postural stability, balance, and upper limb motor function. In addition, the usefulness of canoe game-based virtual reality training was assessed in the EG and therapist group (TG; n=20), which consisted of physical and occupational therapists, by using the System Usability Scale (SUS). [Results] Improvements in trunk postural stability, balance, and upper limb motor function were observed in the EG and CG, but were greater in the EG. The mean SUS scores in the EG and TG were 71 ± 5.2 and 74.2 ± 4.8, respectively. [Conclusion] Canoe game-based virtual reality training is an acceptable and effective intervention for improving trunk postural stability, balance, and upper limb motor function in stroke patients. PMID:27512255

  4. Canoe game-based virtual reality training to improve trunk postural stability, balance, and upper limb motor function in subacute stroke patients: a randomized controlled pilot study

    PubMed Central

    Lee, Myung-Mo; Shin, Doo-Chul; Song, Chang-Ho

    2016-01-01

    [Purpose] This study was aimed at investigating the preliminary therapeutic efficacy and usefulness of canoe game-based virtual reality training for stroke patients. [Subjects and Methods] Ten stroke patients were randomly assigned to an experimental group (EG; n=5) or a control group (CG; n=5). Patients in both groups participated in a conventional rehabilitation program, but those in the EG additionally participated in a 30-min canoe game-based virtual reality training program 3 days a week for 4 weeks. Therapeutic efficacy was assessed based on trunk postural stability, balance, and upper limb motor function. In addition, the usefulness of canoe game-based virtual reality training was assessed in the EG and therapist group (TG; n=20), which consisted of physical and occupational therapists, by using the System Usability Scale (SUS). [Results] Improvements in trunk postural stability, balance, and upper limb motor function were observed in the EG and CG, but were greater in the EG. The mean SUS scores in the EG and TG were 71 ± 5.2 and 74.2 ± 4.8, respectively. [Conclusion] Canoe game-based virtual reality training is an acceptable and effective intervention for improving trunk postural stability, balance, and upper limb motor function in stroke patients. PMID:27512255

  5. Functional splinting of upper limb injuries with gauze-based topical negative pressure wound therapy.

    PubMed

    Taylor, Christopher J; Chester, Darren L; Jeffery, Steven L

    2011-11-01

    Complex hand injuries can be difficult to dress effectively and achieve adequate splintage of the hand in a functional position. During the past 7 years, we have had a great deal of success with topical negative-pressure dressings in the management of complex blast-related extremity war injuries. We have more recently changed to using a gauze-based system and have found this particularly useful in dressing complex hand injuries. We have been able to use this vacuum dressing system to splint the hand in a position of function. This provides an easily applied dressing that, through topical negative pressure, promotes wound healing and ensures a resting functional position, thus minimizing postoperative stiffness. We have not been able to achieve this as efficiently with standard dressings and plaster-of-Paris casts. This article details the technique of functional splinting of complex hand injuries using a gauze-based, topical negative-pressure dressing system. PMID:22036283

  6. The use of virtual reality-based therapy to augment poststroke upper limb recovery

    PubMed Central

    Samuel, Geoffrey S; Choo, Min; Chan, Wai Yin; Kok, Stanley; Ng, Yee Sien

    2015-01-01

    Stroke remains one of the major causes of disability worldwide. This case report illustrates the complementary use of biomechanical and kinematic in-game markers, in addition to standard clinical outcomes, to comprehensively assess and track a patient’s disabilities. A 65-year-old patient was admitted for right-sided weakness and clinically diagnosed with acute ischaemic stroke. She participated in a short trial of standard stroke occupational therapy and physiotherapy with additional daily virtual reality (VR)-based therapy. Outcomes were tracked using kinematic data and conventional clinical assessments. Her Functional Independence Measure score improved from 87 to 113 and Fugl-Meyer motor score improved from 56 to 62, denoting clinically significant improvement. Corresponding kinematic analysis revealed improved hand path ratios and a decrease in velocity peaks. Further research is being undertaken to elucidate the optimal type, timing, setting and duration of VR-based therapy, as well as the use of neuropharmacological adjuncts. PMID:26243983

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

    PubMed

    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. PMID:22015369

  8. Identification-Based Closed-Loop NMES Limb Tracking With Amplitude-Modulated Control Input.

    PubMed

    Cheng, Teng-Hu; Wang, Qiang; Kamalapurkar, Rushikesh; Dinh, Huyen T; Bellman, Matthew; Dixon, Warren E

    2016-07-01

    An upper motor neuron lesion (UMNL) can be caused by various neurological disorders or trauma and leads to disabilities. Neuromuscular electrical stimulation (NMES) is a technique that is widely used for rehabilitation and restoration of motor function for people suffering from UMNL. Typically, stability analysis for closed-loop NMES ignores the modulated implementation of NMES. However, electrical stimulation must be applied to muscle as a modulated series of pulses. In this paper, a muscle activation model with an amplitude modulated control input is developed to capture the discontinuous nature of muscle activation, and an identification-based closed-loop NMES controller is designed and analyzed for the uncertain amplitude modulated muscle activation model. Semi-global uniformly ultimately bounded tracking is guaranteed. The stability of the closed-loop system is analyzed with Lyapunov-based methods, and a pulse frequency related gain condition is obtained. Experiments are performed with five able-bodied subjects to demonstrate the interplay between the control gains and the pulse frequency, and results are provided which indicate that control gains should be increased to maintain stability if the stimulation pulse frequency is decreased to mitigate muscle fatigue. For the first time, this paper brings together an analysis of the controller and modulation scheme. PMID:26241989

  9. Automatic registration of laser-scanned point clouds based on planar features

    NASA Astrophysics Data System (ADS)

    Li, Minglei; Gao, Xinyuan; Wang, Li; Li, Guangyun

    2016-03-01

    Automatic multistation registration of laser-scanned point clouds is a research hotspot in laser-scanned point clouds registration. Some targets such as common buildings have plenty of planar features, and using these features as constraints properly can bring about high accuracy registration results. Starting from this, a new automatic multistation registration method using homologous planar features of two scan stations was proposed. In order to recognize planes from different scan stations and get plane equations in corresponding scan station coordinate systems, k-means dynamic clustering method was improved to be adaptive and robust. And to match the homologous planes of the two scan stations, two different procedures were proposed, respectively, one of which was based on the "common" relationship between planes and the other referenced RANSAC algorithm. And the transformation parameters of the two scan station coordinate systems were calculated after homologous plane matching. Finally, the transformation parameters based on the optimal match of planes was adopted as the final registration result. Comparing with ICP algorithm in experiment, the method is proved to be effective.

  10. PE-CMOS based C-scan ultrasound for foreign object detection in soft tissue.

    PubMed

    Liu, Chu-Chuan; Lo, Shih-Chung Ben; Freedman, Matthew T; Lasser, Marvin E; Kula, John; Sarcone, Anita; Wang, Yue

    2010-01-01

    In this paper, we introduce a C-scan ultrasound prototype and three imaging modalities for the detection of foreign objects inserted in porcine soft tissue. The object materials include bamboo, plastics, glass and aluminum alloys. The images of foreign objects were acquired using the C-scan ultrasound, a portable B-scan ultrasound, film-based radiography, and computerized radiography. The C-scan ultrasound consists of a plane wave transducer, a compound acoustic lens system, and a newly developed ultrasound sensor array based on the complementary metal-oxide semiconductor coated with piezoelectric material (PE-CMOS). The contrast-to-noise ratio (CNR) of the images were analyzed to quantitatively evaluate the detectability using different imaging modalities. The experimental results indicate that the C-scan prototype has better CNR values in 4 out of 7 objects than other modalities. Specifically, the C-scan prototype provides more detail information of the soft tissues without the speckle artifacts that are commonly seen with conventional B-scan ultrasound, and has the same orientation as the standard radiographs but without ionizing radiation. PMID:20036873

  11. High-fidelity AFM scanning stage based on multilayer ceramic capacitors.

    PubMed

    Chen, Jian; Zhang, Lian Sheng; Feng, Zhi Hua

    2016-05-01

    A kind of multilayer ceramic capacitors (MLCCs) has been verified to have good micro-actuating properties, thus making them good candidates for nano-positioning. In this paper, we successfully employed the MLCCs as lateral scanners for a tripod scanning stage. The MLCC-based lateral scanners display hysteresis under 1.5% and a nonlinearity less than 2% even with the simplest open-loop voltage drive. The developed scanning stage was integrated into a commercial AFM to evaluate its imaging performance. Experimental results showed that sample images with high fidelities were obtained. SCANNING 38:184-190, 2016. © 2015 Wiley Periodicals, Inc. PMID:26367125

  12. Image Quality Analysis and Optical Performance Requirement for Micromirror-Based Lissajous Scanning Displays

    PubMed Central

    Du, Weiqi; Zhang, Gaofei; Ye, Liangchen

    2016-01-01

    Micromirror-based scanning displays have been the focus of a variety of applications. Lissajous scanning displays have advantages in terms of power consumption; however, the image quality is not good enough. The main reason for this is the varying size and the contrast ratio of pixels at different positions of the image. In this paper, the Lissajous scanning trajectory is analyzed and a new method based on the diamond pixel is introduced to Lissajous displays. The optical performance of micromirrors is discussed. A display system demonstrator is built, and tests of resolution and contrast ratio are conducted. The test results show that the new Lissajous scanning method can be used in displays by using diamond pixels and image quality remains stable at different positions. PMID:27187390

  13. Bone scanning.

    PubMed

    Greenfield, L D; Bennett, L R

    1975-03-01

    Scanning is based on the uptake of a nuclide by the crystal lattice of bone and is related to bone blood flow. Cancer cells do not take up the tracer. Normally, the scan visualizes the highly vascular bones. Scans are useful and are indicated in metastatic bone disease, primary bone tumors, hematologic malignancies and some non-neoplastic diseases. The scan is more sensitive than x-ray in the detection of malignant diseases of the skeleton. PMID:1054210

  14. A Kinect-Based System for Lower Limb Rehabilitation in Parkinson's Disease Patients: a Pilot Study.

    PubMed

    Palacios-Navarro, Guillermo; García-Magariño, Iván; Ramos-Lorente, Pedro

    2015-09-01

    This work brings together the emerging virtual reality techniques and the natural user interfaces to offer new possibilities in the field of rehabilitation. We have designed a rehabilitation game based on a low cost device (Microsoft Kinect(TM)) connected to a personal computer. It provides patients having Parkinson's Disease (PD) with a motivating way to perform several motor rehabilitation exercises to improve their rehabilitation. The experiment was tested on seven Parkinson's Disease patients and results demonstrated significant improvements in completion time score and in the 10 Meters Walk Test score. Nevertheless, additional research is needed to determine if this type of training has a long-term impact. Both the device and protocol were well accepted by subjects, being safe and easy to use. We conclude that our work provides a simple and suitable tool resulting in a more enriching rehabilitation process where motivation is highly encouraged in PD patients. Feedback coming from participants corroborate the hypothesis that the system can be applied not only in clinical rehabilitation centers but at home. PMID:26265237

  15. Modular neuron-based body estimation: maintaining consistency over different limbs, modalities, and frames of reference.

    PubMed

    Ehrenfeld, Stephan; Herbort, Oliver; Butz, Martin V

    2013-01-01

    This paper addresses the question of how the brain maintains a probabilistic body state estimate over time from a modeling perspective. The neural Modular Modality Frame (nMMF) model simulates such a body state estimation process by continuously integrating redundant, multimodal body state information sources. The body state estimate itself is distributed over separate, but bidirectionally interacting modules. nMMF compares the incoming sensory and present body state information across the interacting modules and fuses the information sources accordingly. At the same time, nMMF enforces body state estimation consistency across the modules. nMMF is able to detect conflicting sensory information and to consequently decrease the influence of implausible sensor sources on the fly. In contrast to the previously published Modular Modality Frame (MMF) model, nMMF offers a biologically plausible neural implementation based on distributed, probabilistic population codes. Besides its neural plausibility, the neural encoding has the advantage of enabling (a) additional probabilistic information flow across the separate body state estimation modules and (b) the representation of arbitrary probability distributions of a body state. The results show that the neural estimates can detect and decrease the impact of false sensory information, can propagate conflicting information across modules, and can improve overall estimation accuracy due to additional module interactions. Even bodily illusions, such as the rubber hand illusion, can be simulated with nMMF. We conclude with an outlook on the potential of modeling human data and of invoking goal-directed behavioral control. PMID:24191151

  16. Modular neuron-based body estimation: maintaining consistency over different limbs, modalities, and frames of reference

    PubMed Central

    Ehrenfeld, Stephan; Herbort, Oliver; Butz, Martin V.

    2013-01-01

    This paper addresses the question of how the brain maintains a probabilistic body state estimate over time from a modeling perspective. The neural Modular Modality Frame (nMMF) model simulates such a body state estimation process by continuously integrating redundant, multimodal body state information sources. The body state estimate itself is distributed over separate, but bidirectionally interacting modules. nMMF compares the incoming sensory and present body state information across the interacting modules and fuses the information sources accordingly. At the same time, nMMF enforces body state estimation consistency across the modules. nMMF is able to detect conflicting sensory information and to consequently decrease the influence of implausible sensor sources on the fly. In contrast to the previously published Modular Modality Frame (MMF) model, nMMF offers a biologically plausible neural implementation based on distributed, probabilistic population codes. Besides its neural plausibility, the neural encoding has the advantage of enabling (a) additional probabilistic information flow across the separate body state estimation modules and (b) the representation of arbitrary probability distributions of a body state. The results show that the neural estimates can detect and decrease the impact of false sensory information, can propagate conflicting information across modules, and can improve overall estimation accuracy due to additional module interactions. Even bodily illusions, such as the rubber hand illusion, can be simulated with nMMF. We conclude with an outlook on the potential of modeling human data and of invoking goal-directed behavioral control. PMID:24191151

  17. Integrated vision-based robotic arm interface for operators with upper limb mobility impairments.

    PubMed

    Jiang, Hairong; Wachs, Juan P; Duerstock, Bradley S

    2013-06-01

    An integrated, computer vision-based system was developed to operate a commercial wheelchair-mounted robotic manipulator (WMRM). In this paper, a gesture recognition interface system developed specifically for individuals with upper-level spinal cord injuries (SCIs) was combined with object tracking and face recognition systems to be an efficient, hands-free WMRM controller. In this test system, two Kinect cameras were used synergistically to perform a variety of simple object retrieval tasks. One camera was used to interpret the hand gestures to send as commands to control the WMRM and locate the operator's face for object positioning. The other sensor was used to automatically recognize different daily living objects for test subjects to select. The gesture recognition interface incorporated hand detection, tracking and recognition algorithms to obtain a high recognition accuracy of 97.5% for an eight-gesture lexicon. An object recognition module employing Speeded Up Robust Features (SURF) algorithm was performed and recognition results were sent as a command for "coarse positioning" of the robotic arm near the selected daily living object. Automatic face detection was also provided as a shortcut for the subjects to position the objects to the face by using a WMRM. Completion time tasks were conducted to compare manual (gestures only) and semi-manual (gestures, automatic face detection and object recognition) WMRM control modes. The use of automatic face and object detection significantly increased the completion times for retrieving a variety of daily living objects. PMID:24187264

  18. Application to monitoring of tailings dam based on 3D laser scanning technology

    NASA Astrophysics Data System (ADS)

    Ren, Fang; Zhang, Aiwu

    2011-06-01

    This paper presented a new method of monitoring of tailing dam based on 3D laser scanning technology and gave the method flow of acquiring and processing the tailing dam data. Taking the measured data for example, the author analyzed the dam deformation by generating the TIN, DEM and the curvature graph, and proved that it's feasible to global monitor the tailing dam using 3D laser scanning technology from the theory and method.

  19. LIMB PROCESS DEVELOPMENT STUDIES

    EPA Science Inventory

    The report covers basic and applied studies concerned with three Limestone Injection Multistage Burner (LIMB) process objectives: (1) avoiding degradation of collection efficiency in the electrostatic precipitator (ESP) during LIMB, (2) achieving satisfactory sulfur dioxide (SO2)...

  20. Phantom limb pain

    MedlinePlus

    ... limb is still there. This is called phantom sensation. It may feel: Tingly Prickly Numb Hot or ... your missing limb is getting shorter (telescoping) These sensations slowly get weaker and weaker. You should also ...

  1. Lipotyphla limb myology comparison.

    PubMed

    Neveu, Pauline; Gasc, Jean-Pierre

    2002-05-01

    Fore- and hindlimb muscles were dissected in four species of Lipotyphla: the western European hedgehog Erinaceus europaeus (Erinaceidae, Erinaceinae); the moonrat Echinosorex gymnura (Erinaceidae, Hylomyinae or Galericinae); the tailless tenrec Tenrec ecaudatus (Tenrecidae, Tenrecinae); and the common European white-toothed shrew Crocidura russula (Soricidae, Soricinae). This work completely reviews the limb musculature of these walking mammals. Twelve myological characters were evaluated in order to disclose phylogenetic relationships. The cladogram obtained supported previous ones based on cranial and dental characters. This study shows that myological characters are valuable in phylogenetic analyses. PMID:11921044

  2. Scan Profiles Based Method for Segmentation and Extraction of Planar Objects in Mobile Laser Scanning Point Clouds

    NASA Astrophysics Data System (ADS)

    Nguyen, Hoang Long; Belton, David; Helmholz, Petra

    2016-06-01

    The demand for accurate spatial data has been increasing rapidly in recent years. Mobile laser scanning (MLS) systems have become a mainstream technology for measuring 3D spatial data. In a MLS point cloud, the point clouds densities of captured point clouds of interest features can vary: they can be sparse and heterogeneous or they can be dense. This is caused by several factors such as the speed of the carrier vehicle and the specifications of the laser scanner(s). The MLS point cloud data needs to be processed to get meaningful information e.g. segmentation can be used to find meaningful features (planes, corners etc.) that can be used as the inputs for many processing steps (e.g. registration, modelling) that are more difficult when just using the point cloud. Planar features are dominating in manmade environments and they are widely used in point clouds registration and calibration processes. There are several approaches for segmentation and extraction of planar objects available, however the proposed methods do not focus on properly segment MLS point clouds automatically considering the different point densities. This research presents the extension of the segmentation method based on planarity of the features. This proposed method was verified using both simulated and real MLS point cloud datasets. The results show that planar objects in MLS point clouds can be properly segmented and extracted by the proposed segmentation method.

  3. Calibration of area based diameter distribution with individual tree based diameter estimates using airborne laser scanning

    NASA Astrophysics Data System (ADS)

    Xu, Qing; Hou, Zhengyang; Maltamo, Matti; Tokola, Timo

    2014-07-01

    Diameter distribution is essential for calculating stem volume and timber assortments of forest stands. A new method was proposed in this study to improve the estimation of stem volume and timber assortments, by means of combining the Area-based approach (ABA) and individual tree detection (ITD), the two main approaches to deriving forest attributes from airborne laser scanning (ALS) data. Two methods, replacement, and histogram matching were employed to calibrate ABA-derived diameter distributions with ITD-derived diameter estimates at plot level. The results showed that more accurate estimates were obtained when calibrations were applied. In view of the highest accuracy between ABA and ITD, calibrated diameter distributions decreased its relative RMSE of the estimated entire growing stock, saw log and pulpwood fractions by 2.81%, 3.05% and 7.73% points at best, respectively. Calibration improved pulpwood fraction significantly, which contributed to the negligible bias of the estimated entire growing stock.

  4. Assessing upper limb function in multiple sclerosis.

    PubMed

    Lamers, Ilse; Feys, Peter

    2014-06-01

    The need to fully assess upper limb function in multiple sclerosis (MS) has become increasingly clear with recent studies revealing a high prevalence of upper limb dysfunction in persons with MS leading to increased dependency and reduced quality of life. It is important that clinicians and researchers use tailored outcome measures to systematically describe upper limb (dys)function and evaluate potential deterioration or improvement on treatment. This topical review provides a comprehensive summary of currently used upper limb outcome measures in MS, classified according to the levels of the International Classification of Functioning (ICF). The clinical utility, strengths, weaknesses and psychometric properties of common upper limb outcome measures are discussed. Based on this information, recommendations for selecting appropriate upper limb outcome measures are given. The current shortcomings in assessment which need to be addressed are identified. PMID:24664300

  5. A Match-based approach to the estimation of polar stratospheric ozone loss using Aura Microwave Limb Sounder observations

    NASA Astrophysics Data System (ADS)

    Livesey, N. J.; Santee, M. L.; Manney, G. L.

    2015-04-01

    The well-established "Match" approach to quantifying chemical destruction of ozone in the polar lower stratosphere is applied to ozone observations from the Microwave Limb Sounder (MLS) on NASA's Aura spacecraft. Quantification of ozone loss requires distinguishing transport- and chemically induced changes in ozone abundance. This is accomplished in the Match approach by examining cases where trajectories indicate that the same airmass has been observed on multiple occasions. The method was pioneered using ozone sonde observations, for which hundreds of matched ozone observations per winter are typically available. The dense coverage of the MLS measurements, particularly at polar latitudes, allows matches to be made to thousands of observations each day. This study is enabled by recently developed MLS Lagrangian Trajectory Diagnostic (LTD) support products. Sensitivity studies indicate that the largest influence on the ozone loss estimates are the value of potential vorticity (PV) used to define the edge of the polar vortex (within which matched observations must lie) and the degree to which the PV of an airmass is allowed to vary between matched observations. Applying Match calculations to MLS observations of nitrous oxide, a long-lived tracer whose expected rate of change on these timescales is negligible, enables quantification of the impact of transport errors on the Match-based ozone loss estimates. Our loss estimates are generally in agreement with previous estimates for selected Arctic winters, though indicating smaller losses than many other studies. Arctic ozone losses are greatest during the 2010/11 winter, as seen in prior studies, with 2.0 ppmv (parts per million by volume) loss estimated at 450 K potential temperature. As expected, Antarctic winter ozone losses are consistently greater than those for the Arctic, with less interannual variability (e.g., ranging between 2.3 and 3.0 ppmv at 450 K). This study exemplifies the insights into atmospheric

  6. Long-term effects of injection of botulinum toxin type A combined with home-based functional training for post-stroke patients with spastic upper limb hemiparesis.

    PubMed

    Takekawa, Toru; Abo, Masahiro; Ebihara, Kazuaki; Taguchi, Kensuke; Sase, Yousuke; Kakuda, Wataru

    2013-12-01

    The aim of this study was to assess the effects of botulinum toxin type A (BoNT-A) injection with home-based functional training for passive and active motor function, over a 6-month period in post-stroke patients with upper limb spasticity. We studied 190 patients with at least 6-month history of stroke. They received injections of BoNT-A in upper limb muscles and detailed one-to-one instructions for home-based functional training. At baseline (before therapy), and at 1-, 3- and 6-month follow-up, Fugl-Meyer assessment (FMA) and Wolf motor function test (WMFT) were used to assess active motor function, the modified Ashworth scale (MAS) for assessment of spasticity, and the range of motion (ROM) for passive motor function. The total score for upper limb and scores of categories A and B of the FMA increased significantly at 1, 3 and 6 months, while the FMA score for category D increased significantly at 3 and 6 months, but not at 1 month. Significant decreases in the MAS scores were noted in all muscles examined at 1, 3 and 6 months, compared with baseline. The ROM for elbow joint extension significantly improved at 1, 3, and 6 months, while that for wrist joint extension increased significantly at 1 month, but not 3 or 6 months, compared with baseline. The results suggest that comprehensive improvement of motor function requires improvement of motor function in the proximal part of the upper limb and that BoNT-A followed by rehabilitation reduces spasticity and improves motor function of fingers. PMID:23716062

  7. Retrieval of atomic oxygen and temperature in the thermosphere. Part 1: Feasibility of an experiment based on the spectrally resolved 147 micrometer limb emission

    NASA Astrophysics Data System (ADS)

    Zachor, A. S.; Sharma, R. D.; Yap, B. K.; Riehl, J. P.

    1989-04-01

    The importance of atomic oxygen and translational temperature in mesospheric/thermospheric processes is the motivation to study the feasibility of recovering vertical profiles of the temperature and O-atom density from limb scan data obtained near 147 micrometer and/or 63 micrometer wavelength, corresponding to the oxygen atom ground electronic state (OI) transitions. The limb radiance data must be spectrally resolved to recover both temperature and atomic oxygen density if only one of the OI lines is used, which is the approach investigated in this report. We show how the two vertical profiles can be recovered by applying an onion-peeling method to synthetic data. The temperature and O-atom density in each peeled layer are obtained simultaneously by nonlinear least-squares spectrum fitting. Spectral data in the 147 micrometer line was found to yield reasonably accurate and stable profiles from 300 km down to an altitude between 130 and 90 km, depending on the noise level and spectral resolution, and gave better results than the stronger 63 micrometer data below 140 km. We estimate that the S/N and spectral resolution required for successful retrievals could be provided by a confocal Fabry-Perot system operating near 147 micrometer although retrievals down to 90 km from data obtained at orbital altitude would require cooled foreoptics roughly a meter in diameter.

  8. On the power for linkage detection using a test based on scan statistics.

    PubMed

    Hernández, Sonia; Siegmund, David O; de Gunst, Mathisca

    2005-04-01

    We analyze some aspects of scan statistics, which have been proposed to help for the detection of weak signals in genetic linkage analysis. We derive approximate expressions for the power of a test based on moving averages of the identity by descent allele sharing proportions for pairs of relatives at several contiguous markers. We confirm these approximate formulae by simulation. The results show that when there is a single trait-locus on a chromosome, the test based on the scan statistic is slightly less powerful than that based on the customary allele sharing statistic. On the other hand, if two genes having a moderate effect on a trait lie close to each other on the same chromosome, scan statistics improve power to detect linkage. PMID:15772104

  9. Congenital limb deficiency disorders.

    PubMed

    Wilcox, William R; Coulter, Colleen P; Schmitz, Michael L

    2015-06-01

    Congenital limb deficiency disorders (LDDs) are birth defects characterized by the aplasia or hypoplasia of bones of the limbs. Limb deficiencies are classified as transverse, those due to intrauterine disruptions of previously normal limbs, or longitudinal, those that are isolated or associated with certain syndromes as well as chromosomal anomalies. Consultation with a medical geneticist is advisable. Long-term care should occur in a specialized limb deficiency center with expertise in orthopedics, prosthetics, and occupational and physical therapy and provide emotional support and contact with other families. With appropriate care, most children with LDDs can lead productive lives. PMID:26042905

  10. Decomposing Scanned Assembly Meshes Based on Periodicity Recognition and Its Application to Kinematic Simulation Modeling

    NASA Astrophysics Data System (ADS)

    Mizoguchi, Tomohiro; Kanai, Satoshi

    Along with the rapid growth of industrial X-ray CT scanning systems, it is now possible to non-destructively acquire the entire meshes of assemblies consisting of a set of parts. For the advanced inspections of the assemblies, such as estimation of their assembling errors or examinations of their behaviors in the motions, based on their CT scanned meshes, it is necessary to accurately decompose the mesh and to extract a set of partial meshes each of which correspond to a part. Moreover it is required to create models which can be used for the real-product based simulations. In this paper, we focus on CT scanned meshes of gear assemblies as examples and propose beneficial methods for establishing such advance inspections of the assemblies. We first propose a method that accurately decomposes the mesh into partial meshes each of which corresponds to a gear based on periodicity recognitions. The key idea is first to accurately recognize the periodicity of each gear and then to extract the partial meshes as sets of topologically connected mesh elements where periodicities are valid. Our method can robustly and accurately recognize periodicities from noisy scanned meshes. In contrast to previous methods, our method can deal with single-material CT scanned meshes and can estimate the correct boundaries of neighboring parts with no previous knowledge. Moreover it can efficiently extract the partial meshes from large scanned meshes containing about one million triangles in a few minutes. We also propose a method for creating simulation models which can be used for a gear teeth contact evaluation using extracted partial meshes and their periodicities. Such an evaluation of teeth contacts is one of the most important functions in kinematic simulations of gear assemblies for predicting the power transmission efficiency, noise and vibration. We demonstrate the effectiveness of our method on a variety of artificial and CT scanned meshes.

  11. A 2-axis Polydimethylsiloxane (PDMS) based electromagnetic MEMS scanning mirror for optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Kim, Sehui; Lee, Changho; Kim, Jin Young; Lim, Geunbae; Kim, Jeehyun; Kim, Chulhong

    2016-03-01

    Optical coherence tomography (OCT) is a noninvasive imaging tool for visualizing cross-sectional images of biological tissues on a microscale. Various microelectromechanical system (MEMS) techniques have been applied to OCT for endoscopic catheters and handheld probes. Despite having several advantages such as compact sizes and high speeds for real-time imaging, the complexities of the fabrication processes and relatively high costs were bottlenecks for fast clinical translation and commercialization of the earlier MEMS scanners. To overcome these issues, we developed a 2-axis polydimethylsiloxane (PDMS)-based electromagnetic MEMS scanning mirror based on flexible, cost-effective, and handleable PDMS. The size of this MEMS scanner was 15 × 15 × 15 mm3. To realize the characteristics of the scanner, we obtained the DC/AC responses and scanning patterns. The measured maximum scanning angles were 16.6° and 11.6° along the X and Y axes, respectively. The resonance frequencies were 82 and 57 Hz along the X and Y axes, respectively. The scanning patterns (raster and Lissajous scan patterns) are also demonstrated by controlling the frequency and amplitude. Finally, we showed the in vivo 2D-OCT images of human fingers by using a spectral domain OCT system with a PDMSbased MEMS scanning mirror. We then reconstructed the 3D images of human fingers. The obtained field of view was 8 × 8 mm2. The PDMS-based MEMS scanning mirror has the potential to combine other optical modalities and be widely used in preclinical and clinical translation research.

  12. Review of P-scan computer-based ultrasonic inservice inspection system. Supplement 1

    SciTech Connect

    Harris, R.V. Jr.; Angel, L.J.

    1995-12-01

    This Supplement reviews the P-scan system, a computer-based ultrasonic system used for inservice inspection of piping and other components in nuclear power plants. The Supplement was prepared using the methodology described in detail in Appendix A of NUREG/CR-5985, and is based on one month of using the system in a laboratory. This Supplement describes and characterizes: computer system, ultrasonic components, and mechanical components; scanning, detection, digitizing, imaging, data interpretation, operator interaction, data handling, and record-keeping. It includes a general description, a review checklist, and detailed results of all tests performed.

  13. MEMS scanning laser projection based on high-Q vacuum packaged 2D-resonators

    NASA Astrophysics Data System (ADS)

    Hofmann, U.; Eisermann, C.; Quenzer, H.-J.; Janes, J.; Schroeder, C.; Schwarzelbach, O.; Jensen, B.; Ratzmann, L.; Giese, T.; Senger, F.; Hagge, J.; Weiss, M.; Wagner, B.; Benecke, W.

    2011-03-01

    Small size, low power consumption and the capability to produce sharp images without need of an objective make MEMS scanning laser based pico-projectors an attractive solution for embedded cell-phone projection displays. To fulfil the high image resolution demands the MEMS scanning mirror has to show large scan angles, a large mirror aperture size and a high scan frequency. An additional important requirement in pico-projector applications is to minimize power consumption of the MEMS scanner to enable a long video projection time. Typically high losses in power are caused by gas damping. For that reason Fraunhofer ISIT has established a fabrication process for 2D-MEMS mirrors that includes vacuum encapsulation on 8-inch wafers. Quality factors as high as 145,000 require dedicated closed loop phase control electronics to enable stable image projection even at rapidly changing laser intensities. A capacitive feedback signal is the basis for controlling the 2D MEMS oscillation and for synchronising the laser sources. This paper reports on fabrication of two-axis wafer level vacuum packaged scanning micromirrors and its use in a compact laser projection display. The paper presents different approaches of overcoming the well-known reflex problem of packaged MEMS scanning mirrors.

  14. Vertical scanning white light interfering profilometer based on Linnik interference microscope

    NASA Astrophysics Data System (ADS)

    Wang, Shuzhen; Xie, Tiebang; Chang, Suping

    2010-10-01

    In this paper we provide a vertical scanning white light interfering profilometer based on Linnik type interference microscope. A vertical scanning system with coarse-fine dual-stage actuators is developed, in which the coarse positioning is performed by inclined sliding guides, AC servo motor, ballscrew and the fine positioning is performed by parallel board flexure hinge and piezoelectric ceramic, respectively. The displacement range of the vertical scanning system is 0~2mm and 0.4nm theoretical motion resolution can be achieved. The whole interference microscope of the profilometer is driven by the vertical scanning system, which will eliminate the movement coupling error of vertical direction caused by horizontal movement of 2D precision stage. The interference fringes or the focal plane can be automatically located by moving the vertical scanning system. To eliminate the measurement errors of the profilometer caused by incorrect positioning of the vertical scanning system, its displacement is measured in real-time by a laser interferometer with theoretical resolution of 0.01nm. A single groove specimen with the depth of 1.26μm calibrated by National Institute of Metrology P.R.China, MEMS device and textured steel sheet was measured to illustrate the capabilities of the profilometer.

  15. The effect of limb crossing and limb congruency on multisensory integration in peripersonal space for the upper and lower extremities.

    PubMed

    van Elk, Michiel; Forget, Joachim; Blanke, Olaf

    2013-06-01

    The present study investigated how multisensory integration in peripersonal space is modulated by limb posture (i.e. whether the limbs are crossed or uncrossed) and limb congruency (i.e. whether the observed body part matches the actual position of one's limb). This was done separately for the upper limbs (Experiment 1) and the lower limbs (Experiment 2). The crossmodal congruency task was used to measure peripersonal space integration for the hands and the feet. It was found that the peripersonal space representation for the hands but not for the feet is dynamically updated based on both limb posture and limb congruency. Together these findings show how dynamic cues from vision, proprioception, and touch are integrated in peripersonal limb space and highlight fundamental differences in the way in which peripersonal space is represented for the upper and lower extremity. PMID:23579198

  16. A Tool-Free Calibration Method for Turntable-Based 3D Scanning Systems.

    PubMed

    Pang, Xufang; Lau, Rynson W H; Song, Zhan; Li, Yangyan; He, Shengfeng

    2016-01-01

    Turntable-based 3D scanners are popular but require calibration of the turntable axis. Existing methods for turntable calibration typically make use of specially designed tools, such as a chessboard or criterion sphere, which users must manually install and dismount. In this article, the authors propose an automatic method to calibrate the turntable axis without any calibration tools. Given a scan sequence of the input object, they first recover the initial rotation axis from an automatic registration step. Then they apply an iterative procedure to obtain the optimized turntable axis. This iterative procedure alternates between two steps: refining the initial pose of the input scans and approximating the rotation matrix. The performance of the proposed method was evaluated on a structured light-based scanning system. PMID:25137724

  17. A voice coil motor based measuring force control system for tactile scanning profiler

    NASA Astrophysics Data System (ADS)

    Feng, Shengdong; Liu, Xiaojun; Chen, Liangzhou; Zhou, Liping; Lu, Wenlong

    2015-02-01

    In tactile scanning profiler, the measuring force would change in a wide range when it was used for profile measurement in a large range, which could possibly destroy the measured surface. To solve the problem, measuring force control system for tactile scanning profiler was needed. In the paper, a voice coil motor-based measuring force control system for tactile scanning profiler was designed. In the design, a low stiffness coefficient spring was used to provide contact force, while a voice coil motor (VCM) to balance the spring force so that the contact force could be kept for constant measuring force. A VCM was designed specially, and for active measuring force control, a precision current source circuit under the control of a DSP unit was designed to drive the VCM. The performance of voice coil motor based measuring force control system had been tested, and its good characteristics were verified.

  18. Autoblocker: a system for detecting and blocking of network scanning based on analysis of netflow data

    SciTech Connect

    Bobyshev, A.; Lamore, D.; Demar, P.; /Fermilab

    2004-12-01

    In a large campus network, such at Fermilab, with tens of thousands of nodes, scanning initiated from either outside of or within the campus network raises security concerns. This scanning may have very serious impact on network performance, and even disrupt normal operation of many services. In this paper we introduce a system for detecting and automatic blocking excessive traffic of different kinds of scanning, DoS attacks, virus infected computers. The system, called AutoBlocker, is a distributed computing system based on quasi-real time analysis of network flow data collected from the border router and core switches. AutoBlocker also has an interface to accept alerts from IDS systems (e.g. BRO, SNORT) that are based on other technologies. The system has multiple configurable alert levels for the detection of anomalous behavior and configurable trigger criteria for automated blocking of scans at the core or border routers. It has been in use at Fermilab for about 2 years, and has become a very valuable tool to curtail scan activity within the Fermilab campus network.

  19. A Match-based approach to the estimation of polar stratospheric ozone loss using Aura Microwave Limb Sounder observations

    NASA Astrophysics Data System (ADS)

    Livesey, N. J.; Santee, M. L.; Manney, G. L.

    2015-09-01

    The well-established "Match" approach to quantifying chemical destruction of ozone in the polar lower stratosphere is applied to ozone observations from the Microwave Limb Sounder (MLS) on NASA's Aura spacecraft. Quantification of ozone loss requires distinguishing transport- and chemically induced changes in ozone abundance. This is accomplished in the Match approach by examining cases where trajectories indicate that the same air mass has been observed on multiple occasions. The method was pioneered using ozonesonde observations, for which hundreds of matched ozone observations per winter are typically available. The dense coverage of the MLS measurements, particularly at polar latitudes, allows matches to be made to thousands of observations each day. This study is enabled by recently developed MLS Lagrangian trajectory diagnostic (LTD) support products. Sensitivity studies indicate that the largest influence on the ozone loss estimates are the value of potential vorticity (PV) used to define the edge of the polar vortex (within which matched observations must lie) and the degree to which the PV of an air mass is allowed to vary between matched observations. Applying Match calculations to MLS observations of nitrous oxide, a long-lived tracer whose expected rate of change is negligible on the weekly to monthly timescales considered here, enables quantification of the impact of transport errors on the Match-based ozone loss estimates. Our loss estimates are generally in agreement with previous estimates for selected Arctic winters, though indicating smaller losses than many other studies. Arctic ozone losses are greatest during the 2010/11 winter, as seen in prior studies, with 2.0 ppmv (parts per million by volume) loss estimated at 450 K potential temperature (~ 18 km altitude). As expected, Antarctic winter ozone losses are consistently greater than those for the Arctic, with less interannual variability (e.g., ranging between 2.3 and 3.0 ppmv at 450 K). This

  20. Scanning microphotolysis: a new photobleaching technique based on fast intensity modulation of a scanned laser beam and confocal imaging.

    PubMed

    Wedekind, P; Kubitscheck, U; Peters, R

    1994-10-01

    The fluorescence photobleaching method has been widely used to study molecular transport in single living cells and other microsystems while confocal microscopy has opened new avenues to high-resolution, three-dimensional imaging. A new technique, scanning microphotolysis (Scamp), combines the potential of photobleaching, beam scanning and confocal imaging. A confocal scanning laser microscope was equipped with a sufficiently powerful laser and a novel device, the 'Scamper'. This consisted essentially of a filter changer, an acousto-optical modulator (AOM) and a computer. The computer was programmed to activate the AOM during scanning according to a freely defined image mask. As a result, almost any desired pattern could be bleached ('written') into fluorescent samples at high definition and then imaged ('read') at non-bleaching conditions, employing full confocal resolution. Furthermore, molecular transport could be followed by imaging the dissipation of bleach patterns. Experiments with living cells concerning dynamic processes in cytoskeletal filaments and the lateral mobility of membrane lipids suggest a wide range of potential biological applications. Thus, Scamp offers new possibilities for the optical manipulation and analysis of both technical and biological microsystems. PMID:7799426

  1. Two Simple Classroom Demonstrations for Scanning Probe Microscopy Based on a Macroscopic Analogy

    ERIC Educational Resources Information Center

    Hajkova, Zdenka; Fejfar, Antonin; Smejkal, Petr

    2013-01-01

    This article describes two simple classroom demonstrations that illustrate the principles of scanning probe microscopy (SPM) based on a macroscopic analogy. The analogy features the bumps in an egg carton to represent the atoms on a chemical surface and a probe that can be represented by a dwarf statue (illustrating an origin of the prefix…

  2. Keypoint-based 4-Points Congruent Sets - Automated marker-less registration of laser scans

    NASA Astrophysics Data System (ADS)

    Theiler, Pascal Willy; Wegner, Jan Dirk; Schindler, Konrad

    2014-10-01

    We propose a method to automatically register two point clouds acquired with a terrestrial laser scanner without placing any markers in the scene. What makes this task challenging are the strongly varying point densities caused by the line-of-sight measurement principle, and the huge amount of data. The first property leads to low point densities in potential overlap areas with scans taken from different viewpoints while the latter calls for highly efficient methods in terms of runtime and memory requirements. A crucial yet largely unsolved step is the initial coarse alignment of two scans without any simplifying assumptions, that is, point clouds are given in arbitrary local coordinates and no knowledge about their relative orientation is available. Once coarse alignment has been solved, scans can easily be fine-registered with standard methods like least-squares surface or Iterative Closest Point matching. In order to drastically thin out the original point clouds while retaining characteristic features, we resort to extracting 3D keypoints. Such clouds of keypoints, which can be viewed as a sparse but nevertheless discriminative representation of the original scans, are then used as input to a very efficient matching method originally developed in computer graphics, called 4-Points Congruent Sets (4PCS) algorithm. We adapt the 4PCS matching approach to better suit the characteristics of laser scans. The resulting Keypoint-based 4-Points Congruent Sets (K-4PCS) method is extensively evaluated on challenging indoor and outdoor scans. Beyond the evaluation on real terrestrial laser scans, we also perform experiments with simulated indoor scenes, paying particular attention to the sensitivity of the approach with respect to highly symmetric scenes.

  3. Radar Scan Strategies for the Patrick Air Force Base Weather Surveillance Radar, Model-74C, Replacement

    NASA Technical Reports Server (NTRS)

    Short, David

    2008-01-01

    The 45th Weather Squadron (45 WS) is replacing the Weather Surveillance Radar, Model 74C (WSR-74C) at Patrick Air Force Base (PAFB), with a Doppler, dual polarization radar, the Radtec 43/250. A new scan strategy is needed for the Radtec 43/250, to provide high vertical resolution data over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) launch pads, while taking advantage of the new radar's advanced capabilities for detecting severe weather phenomena associated with convection within the 45 WS area of responsibility. The Applied Meteorology Unit (AMU) developed several scan strategies customized for the operational needs of the 45 WS. The AMU also developed a plan for evaluating the scan strategies in the period prior to operational acceptance, currently scheduled for November 2008.

  4. Emulation and design of terahertz reflection-mode confocal scanning microscopy based on virtual pinhole

    NASA Astrophysics Data System (ADS)

    Yang, Yong-fa; Li, Qi

    2014-12-01

    In the practical application of terahertz reflection-mode confocal scanning microscopy, the size of detector pinhole is an important factor that determines the performance of spatial resolution characteristic of the microscopic system. However, the use of physical pinhole brings some inconvenience to the experiment and the adjustment error has a great influence on the experiment result. Through reasonably selecting the parameter of matrix detector virtual pinhole (VPH), it can efficiently approximate the physical pinhole. By using this approach, the difficulty of experimental calibration is reduced significantly. In this article, an imaging scheme of terahertz reflection-mode confocal scanning microscopy that is based on the matrix detector VPH is put forward. The influence of detector pinhole size on the axial resolution of confocal scanning microscopy is emulated and analyzed. Then, the parameter of VPH is emulated when the best axial imaging performance is reached.

  5. Optical tomographic scanning target-tracking system based on single pixel sensor

    NASA Astrophysics Data System (ADS)

    Li, Baosheng; Wang, Yicheng; Yang, Jiuchun

    2015-11-01

    Optical tomography imaging had the characteristics of high resolution. The rotating periscope system and modulating plate with 65 slits were designed. Filter back projection (FBP) algorithm was applied to the one-dimensional signals, which were obtained by multi-angle scanning in modulating plate, to reconstruct two-dimensional image. Single pixel photoelectric sensor has high frequency response and can acquire high speed real-time signal. This work had carried on the simulation and experiment about scanning system based on the analysis and determination about the modulating plate's parameters, and verify the feasibility of scanning system. In this paper, the method plays an important role in developing novel target tracking system and provides deep foundation for deeper experimental research.

  6. The correction of vibration in frequency scanning interferometry based absolute distance measurement system for dynamic measurements

    NASA Astrophysics Data System (ADS)

    Lu, Cheng; Liu, Guodong; Liu, Bingguo; Chen, Fengdong; Zhuang, Zhitao; Xu, Xinke; Gan, Yu

    2015-10-01

    Absolute distance measurement systems are of significant interest in the field of metrology, which could improve the manufacturing efficiency and accuracy of large assemblies in fields such as aircraft construction, automotive engineering, and the production of modern windmill blades. Frequency scanning interferometry demonstrates noticeable advantages as an absolute distance measurement system which has a high precision and doesn't depend on a cooperative target. In this paper , the influence of inevitable vibration in the frequency scanning interferometry based absolute distance measurement system is analyzed. The distance spectrum is broadened as the existence of Doppler effect caused by vibration, which will bring in a measurement error more than 103 times bigger than the changes of optical path difference. In order to decrease the influence of vibration, the changes of the optical path difference are monitored by a frequency stabilized laser, which runs parallel to the frequency scanning interferometry. The experiment has verified the effectiveness of this method.

  7. Learning-based scan plane identification from fetal head ultrasound images

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoming; Annangi, Pavan; Gupta, Mithun; Yu, Bing; Padfield, Dirk; Banerjee, Jyotirmoy; Krishnan, Kajoli

    2012-03-01

    Acquisition of a clinically acceptable scan plane is a pre-requisite for ultrasonic measurement of anatomical features from B-mode images. In obstetric ultrasound, measurement of gestational age predictors, such as biparietal diameter and head circumference, is performed at the level of the thalami and cavum septum pelucidi. In an accurate scan plane, the head can be modeled as an ellipse, the thalami looks like a butterfly, the cavum appears like an empty box and the falx is a straight line along the major axis of a symmetric ellipse inclined either parallel to or at small angles to the probe surface. Arriving at the correct probe placement on the mother's belly to obtain an accurate scan plane is a task of considerable challenge especially for a new user of ultrasound. In this work, we present a novel automated learning-based algorithm to identify an acceptable fetal head scan plane. We divide the problem into cranium detection and a template matching to capture the composite "butterfly" structure present inside the head, which mimics the visual cues used by an expert. The algorithm uses the stateof- the-art Active Appearance Models techniques from the image processing and computer vision literature and tie them to presence or absence of the inclusions within the head to automatically compute a score to represent the goodness of a scan plane. This automated technique can be potentially used to train and aid new users of ultrasound.

  8. Theoretical study of carbon-based tips for scanning tunnelling microscopy.

    PubMed

    González, C; Abad, E; Dappe, Y J; Cuevas, J C

    2016-03-11

    Motivated by recent experiments, we present here a detailed theoretical analysis of the use of carbon-based conductive tips in scanning tunnelling microscopy. In particular, we employ ab initio methods based on density functional theory to explore a graphitic, an amorphous carbon and two diamond-like tips for imaging with a scanning tunnelling microscope (STM), and we compare them with standard metallic tips made of gold and tungsten. We investigate the performance of these tips in terms of the corrugation of the STM images acquired when scanning a single graphene sheet. Moreover, we analyse the impact of the tip-sample distance and show that it plays a fundamental role in the resolution and symmetry of the STM images. We also explore in depth how the adsorption of single atoms and molecules in the tip apexes modifies the STM images and demonstrate that, in general, it leads to an improved image resolution. The ensemble of our results provides strong evidence that carbon-based tips can significantly improve the resolution of STM images, as compared to more standard metallic tips, which may open a new line of research in scanning tunnelling microscopy. PMID:26861537

  9. Theoretical study of carbon-based tips for scanning tunnelling microscopy

    NASA Astrophysics Data System (ADS)

    González, C.; Abad, E.; Dappe, Y. J.; Cuevas, J. C.

    2016-03-01

    Motivated by recent experiments, we present here a detailed theoretical analysis of the use of carbon-based conductive tips in scanning tunnelling microscopy. In particular, we employ ab initio methods based on density functional theory to explore a graphitic, an amorphous carbon and two diamond-like tips for imaging with a scanning tunnelling microscope (STM), and we compare them with standard metallic tips made of gold and tungsten. We investigate the performance of these tips in terms of the corrugation of the STM images acquired when scanning a single graphene sheet. Moreover, we analyse the impact of the tip-sample distance and show that it plays a fundamental role in the resolution and symmetry of the STM images. We also explore in depth how the adsorption of single atoms and molecules in the tip apexes modifies the STM images and demonstrate that, in general, it leads to an improved image resolution. The ensemble of our results provides strong evidence that carbon-based tips can significantly improve the resolution of STM images, as compared to more standard metallic tips, which may open a new line of research in scanning tunnelling microscopy.

  10. Construction of efficacious gait and upper limb functional interventions based on brain plasticity evidence and model-based measures for stroke patients.

    PubMed

    Daly, Janis J; Ruff, Robert L

    2007-01-01

    For neurorehabilitation to advance from art to science, it must become evidence-based. Historically, there has been a dearth of evidence from which to construct rehabilitation interventions that are properly framed, accurately targeted, and credibly measured. In many instances, evidence of treatment response has not been sufficiently robust to demonstrate a change in function that is clinically, statistically, and economically important. Research evidence of activity-dependent central nervous system (CNS) plasticity and the requisite motor learning principles can be used to construct an efficacious motor recovery intervention. Brain plasticity after stroke refers to the regeneration of brain neuronal structures and/or reorganization of the function of neurons. Not only can CNS structure and function change in response to injury, but also, the changes may be modified by "activity". For gait training or upper limb functional training for stroke survivors, the "activity" is motor behavior, including coordination and strengthening exercise and functional training that comprise motor learning. Critical principles of motor learning required for CNS activity-dependent plasticity include: close-to-normal movements, muscle activation driving practice of movement; focused attention, repetition of desired movements, and training specificity. The ultimate goal of rehabilitation is to restore function so that a satisfying quality of life can be experienced. Accurate measurement of dysfunction and its underlying impairments are critical to the development of accurately targeted interventions that are sufficiently robust to produce gains, not only in function, but also in quality of life. The Classification of Functioning, Disability, and Health Model (ICF) model of disablement, put forth by the World Health Organization, can provide not only some guidance in measurement level selection, but also can serve as a guide to incorporate function and quality of life enhancement as the

  11. Telescope beam-profile diagnostics and the solar limb

    SciTech Connect

    Lindsey, C.A.; Roellig, T.L. NASA, Ames Research Center, Moffett Field, CA )

    1991-07-01

    The basic method is described for determining the solar limb brightness profile properly corrected for spurious limb darkening caused by the far wings of the resolving beams encountered in large far-infrared and radio telescopes. When the far wings of the beam can be independently measured this problem is usually amenable to standard deconvolution procedures. Under a broad range of well-defined cases, solutions to the deconvolution problem are unique to within the discrimination provided by the core of the beam profile. The theory is applied to solar limb scans made recently on the James Clerk Maxwell Telscope to show solar limb brightening in 850 micron radiation. 16 refs.

  12. Telescope beam-profile diagnostics and the solar limb

    NASA Technical Reports Server (NTRS)

    Lindsey, Charles A.; Roellig, Thomas L.

    1991-01-01

    The basic method is described for determining the solar limb brightness profile properly corrected for spurious limb darkening caused by the far wings of the resolving beams encountered in large far-infrared and radio telescopes. When the far wings of the beam can be independently measured this problem is usually amenable to standard deconvolution procedures. Under a broad range of well-defined cases, solutions to the deconvolution problem are unique to within the discrimination provided by the core of the beam profile. The theory is applied to solar limb scans made recently on the James Clerk Maxwell Telscope to show solar limb brightening in 850 micron radiation.

  13. Direct absorbed dose to water determination based on water calorimetry in scanning proton beam delivery

    SciTech Connect

    Sarfehnia, A.; Clasie, B.; Chung, E.; Lu, H. M.; Flanz, J.; Cascio, E.; Engelsman, M.; Paganetti, H.; Seuntjens, J.

    2010-07-15

    Purpose: The aim of this manuscript is to describe the direct measurement of absolute absorbed dose to water in a scanned proton radiotherapy beam using a water calorimeter primary standard. Methods: The McGill water calorimeter, which has been validated in photon and electron beams as well as in HDR {sup 192}Ir brachytherapy, was used to measure the absorbed dose to water in double scattering and scanning proton irradiations. The measurements were made at the Massachusetts General Hospital proton radiotherapy facility. The correction factors in water calorimetry were numerically calculated and various parameters affecting their magnitude and uncertainty were studied. The absorbed dose to water was compared to that obtained using an Exradin T1 Chamber based on the IAEA TRS-398 protocol. Results: The overall 1-sigma uncertainty on absorbed dose to water amounts to 0.4% and 0.6% in scattered and scanned proton water calorimetry, respectively. This compares to an overall uncertainty of 1.9% for currently accepted IAEA TRS-398 reference absorbed dose measurement protocol. The absorbed dose from water calorimetry agrees with the results from TRS-398 well to within 1-sigma uncertainty. Conclusions: This work demonstrates that a primary absorbed dose standard based on water calorimetry is feasible in scattered and scanned proton beams.

  14. A knowledge-based system paradigm for automatic interpretation of CT scans.

    PubMed

    Natarajan, K; Cawley, M G; Newell, J A

    1991-01-01

    The interpretation of X-ray CT scans is a task which relies on specialized medical expertise, comprising anatomical, modality-dependent, non-visual and radiological knowledge. Most medical imaging techniques generate a single scan or sequence of two-dimensional scans. The radiologist's experience is gained by interpreting two-dimensional scans. The more complex three-dimensional anatomical knowledge becomes significant only when non-standard slice orientations are used. Hence, implicit in the radiologist's knowledge is the appearance of anatomical structures in standard two-dimensional planes, transverse, sagittal and coronal. That is, position with respect to both a coordinate reference system and other structures; intensity ranges for tissue types; contrast between structures; and size within the slices. Further to this, neurological landmarking is used to establish points of reference, i.e. more easily identifiable structures are first found and subsequent hypotheses are formed. With this in mind we have developed a knowledge-based system paradigm that partitions an image by applying the domain-dependent knowledge necessary (1) to set constraints on region-based segmentation and (2) to make explicit the expectation of the appearance of the anatomy under the imaging modality for use in the region grouping phase. This paradigm affords both expectation- and event-driven segmentation by representing grouping knowledge as production rules. PMID:1921561

  15. Climatology and trends of mesospheric (58-90) temperatures based upon 1982-1986 SME limb scattering profiles

    NASA Technical Reports Server (NTRS)

    Clancy, R. Todd; Rusch, David W.

    1989-01-01

    Atmospheric temperature profiles for the altitude range 58-90 km were calculated using data on global UV limb radiances from the SME satellite. The major elements of this climatology include a high vertical resolution (about 4 km) and the coverage of the 70-90 km altitude region. The analysis of this extensive data set provides a global definition of mesospheric-lower thermospheric temperature trends over the 1982-1986 period. The observations suggest a pattern of 1-2 K/year decreases in temperatures at 80-90-km altitudes accompanied by 0.5-1.5 K/year increases in temperatures at 65-80-km altitudes.

  16. Temporal subtraction system on torso FDG-PET scans based on statistical image analysis

    NASA Astrophysics Data System (ADS)

    Shimizu, Yusuke; Hara, Takeshi; Fukuoka, Daisuke; Zhou, Xiangrong; Muramatsu, Chisako; Ito, Satoshi; Hakozaki, Kenta; Kumita, Shin-ichiro; Ishihara, Kei-ichi; Katafuchi, Tetsuro; Fujita, Hiroshi

    2013-02-01

    Diagnostic imaging on FDG-PET scans was often used to evaluate chemotherapy results of cancer patients. Radiologists compare the changes of lesions' activities between previous and current examinations for the evaluation. The purpose of this study was to develop a new computer-aided detection (CAD) system with temporal subtraction technique for FDGPET scans and to show the fundamental usefulness based on an observer performance study. Z-score mapping based on statistical image analysis was newly applied to the temporal subtraction technique. The subtraction images can be obtained based on the anatomical standardization results because all of the patients' scans were deformed into standard body shape. An observer study was performed without and with computer outputs to evaluate the usefulness of the scheme by ROC (receiver operating characteristics) analysis. Readers responded as confidence levels on a continuous scale from absolutely no change to definitely change between two examinations. The recognition performance of the computer outputs for the 43 pairs was 96% sensitivity with 31.1 false-positive marks per scan. The average of area-under-the-ROC-curve (AUC) from 4 readers in the observer performance study was increased from 0.85 without computer outputs to 0.90 with computer outputs (p=0.0389, DBM-MRMC). The average of interpretation time was slightly decreased from 42.11 to 40.04 seconds per case (p=0.625, Wilcoxon test). We concluded that the CAD system for torso FDG-PET scans with temporal subtraction technique might improve the diagnostic accuracy of radiologist in cancer therapy evaluation.

  17. Clinical evaluation of semi-automatic landmark-based lesion tracking software for CT-scans

    PubMed Central

    2014-01-01

    Background To evaluate a semi-automatic landmark-based lesion tracking software enabling navigation between RECIST lesions in baseline and follow-up CT-scans. Methods The software automatically detects 44 stable anatomical landmarks in each thoraco/abdominal/pelvic CT-scan, sets up a patient specific coordinate-system and cross-links the coordinate-systems of consecutive CT-scans. Accuracy of the software was evaluated on 96 RECIST lesions (target- and non-target lesions) in baseline and follow-up CT-scans of 32 oncologic patients (64 CT-scans). Patients had to present at least one thoracic, one abdominal and one pelvic RECIST lesion. Three radiologists determined the deviation between lesions’ centre and the software’s navigation result in consensus. Results The initial mean runtime of the system to synchronize baseline and follow-up examinations was 19.4 ± 1.2 seconds, with subsequent navigation to corresponding RECIST lesions facilitating in real-time. Mean vector length of the deviations between lesions’ centre and the semi-automatic navigation result was 10.2 ± 5.1 mm without a substantial systematic error in any direction. Mean deviation in the cranio-caudal dimension was 5.4 ± 4.0 mm, in the lateral dimension 5.2 ± 3.9 mm and in the ventro-dorsal dimension 5.3 ± 4.0 mm. Conclusion The investigated software accurately and reliably navigates between lesions in consecutive CT-scans in real-time, potentially accelerating and facilitating cancer staging. PMID:25609496

  18. Can immersive virtual reality reduce phantom limb pain?

    PubMed

    Murray, Craig D; Patchick, Emma L; Caillette, Fabrice; Howard, Toby; Pettifer, Stephen

    2006-01-01

    This paper describes the design and implementation of a case-study based investigation using immersive virtual reality as a treatment for phantom limb pain. The authors' work builds upon prior research which has found the use of a mirror box (where the amputee sees a mirror image of their remaining anatomical limb in the phenomenal space of their amputated limb) can reduce phantom limb pain and voluntary movement to paralyzed phantom limbs for some amputees. The present project involves the transposition of movements made by amputees' anatomical limb into movements of a virtual limb which is presented in the phenomenal space of their phantom limb. The three case studies presented here provide qualitative data which provide tentative support for the use of this system for phantom pain relief. The authors suggest the need for further research using control trials. PMID:16404088

  19. Laser-based ultrasonic inspection with a fiber-coupled scanning Cassegrain system.

    PubMed

    McKie, Andrew D W; Addison, Robert C

    2002-12-01

    State-of-the-art integrally stiffened composite materials, manufactured for use in the next generation of commercial and military aircraft, are increasingly being used for structural components such as wings and fuselages. However, the complexity of the manufacturing processes can produce small variations in the shape of integrally stiffened composite structures. Thus, a priori knowledge of the nominal part shape often does not provide sufficient accuracy to allow an automated conventional ultrasonic inspection. In contrast, automated inspections of integrally stiffened structures can be performed using laser-based ultrasound techniques since a priori knowledge of the nominal part shape is adequate to scan the laser beams over the structure. This paper addresses the issues associated with the extension of laser-based ultrasonics to inspections in remote and limited access areas, and describes the implementation of a fiber-based remote and limited access LBU inspection system based upon a Cassegrain scanning and optical collection system. The ability to quickly and directly manipulate flexible low mass optical fibers equipped with specialized endoscopic scanning optics make fiber systems an attractive method for the development of limited and remote access inspection systems. The Cassegrain optical system is described in detail and both numerical and experimental validation of the system operational characteristics are presented. PMID:12441180

  20. Adaptive circle-ellipse fitting method for estimating tree diameter based on single terrestrial laser scanning

    NASA Astrophysics Data System (ADS)

    Bu, Guochao; Wang, Pei

    2016-04-01

    Terrestrial laser scanning (TLS) has been used to extract accurate forest biophysical parameters for inventory purposes. The diameter at breast height (DBH) is a key parameter for individual trees because it has the potential for modeling the height, volume, biomass, and carbon sequestration potential of the tree based on empirical allometric scaling equations. In order to extract the DBH from the single-scan data of TLS automatically and accurately within a certain range, we proposed an adaptive circle-ellipse fitting method based on the point cloud transect. This proposed method can correct the error caused by the simple circle fitting method when a tree is slanted. A slanted tree was detected by the circle-ellipse fitting analysis, then the corresponding slant angle was found based on the ellipse fitting result. With this information, the DBH of the trees could be recalculated based on reslicing the point cloud data at breast height. Artificial stem data simulated by a cylindrical model of leaning trees and the scanning data acquired with the RIEGL VZ-400 were used to test the proposed adaptive fitting method. The results shown that the proposed method can detect the trees and accurately estimate the DBH for leaning trees.

  1. Neuronal injury in the motor cortex after chronic stroke and lower limb motor impairment: a voxel-based lesion symptom mapping study

    PubMed Central

    Reynolds, Alexandria M.; Peters, Denise M.; Vendemia, Jennifer M. C.; Smith, Lenwood P.; Sweet, Raymond C.; Baylis, Gordon C.; Krotish, Debra; Fritz, Stacy L.

    2014-01-01

    Many studies have examined motor impairments using voxel-based lesion symptom mapping, but few are reported regarding the corresponding relationship between cerebral cortex injury and lower limb motor impairment analyzed using this technique. This study correlated neuronal injury in the cerebral cortex of 16 patients with chronic stroke based on a voxel-based lesion symptom mapping analysis. Neuronal injury in the corona radiata, caudate nucleus and putamen of patients with chronic stroke could predict walking speed. The behavioral measure scores were consistent with motor deficits expected after damage to the cortical motor system due to stroke. These findings suggest that voxel-based lesion symptom mapping may provide a more accurate prognosis of motor recovery from chronic stroke according to neuronal injury in cerebral motor cortex. PMID:25206888

  2. Stationary scanning x-ray source based on carbon nanotube field emitters

    NASA Astrophysics Data System (ADS)

    Yang, Guang; Zhang, Jian; Cheng, Yuan; Gao, Bo; Qiu, Qi; Lee, Yueh; Lu, Jianping; Zhou, Otto

    2006-03-01

    Carbon nanotube is an ideal field emitter thanks to its large aspect ratio and small diameter. Based on its field emission property, we have developed a stationary scanning x-ray source, which can generate a scanning x-ray beam to image an object from multiple projection angles without mechanical motion. The key component of the device is a gated carbon nanotube field emission cathode with an array of electron emitting pixels that are individually addressable via a metal-oxide-semiconductor field effect transistor-based electronic circuit. The characteristics of this x-ray source are measured and its imaging capability is demonstrated. The device can potentially lead to a fast data acquisition rate for laminography and tomosynthesis.

  3. A two-dimensional polarization interferometry based parallel scan angular surface plasmon resonance biosensor.

    PubMed

    Liu, Le; Ma, Suihua; Ji, Yanhong; Chong, Xinyuan; Liu, Zhiyi; He, Yonghong; Guo, Jihua

    2011-02-01

    We describe a two-dimensional polarization interferometry based parallel scan angular surface plasmon resonance (SPR) biosensing technique. The method of line-shaped light illumination and parallel scan offers a high throughput. The simultaneous record of SPR angular spectrum enables the system to be unaffected by the time-dependent variation of the light source. The polarization interferometry technique lowers the minimum of the SPR dip and thereby reduces the noise related to the light intensity. Refractive index resolutions of 1.4 × 10(-6) refractive index unit (RIU) under normal condition and 4.6 × 10(-7) RIU under a more time-consuming condition are achieved in our angle interrogation based sensor. Meanwhile, a manually prepared DNA microarray has been detected, showing the potential applications of this technique in microarray analysis. PMID:21361575

  4. LIMB Demonstration Project Extension

    SciTech Connect

    Not Available

    1989-06-15

    The basic goal of the Limestone Injection Multistage Burner (LIMB) demonstration is to extend LIMB technology development to a full- scale application on a representative wall-fired utility boiler. The successful retrofit of LIMB to an existing boiler is expected to demonstrate that (a) reductions of 50 percent or greater in SO{sub x} and NO{sub x} emissions can be achieved at a fraction of the cost of add-on FGD systems, (b) boiler reliability, operability, and steam production can be maintained at levels existing prior to LIMB retrofit, and (c) technical difficulties attributable to LIMB operation, such as additional slagging and fouling, changes in ash disposal requirements, and an increased particulate load, can be resolved in a cost-effective manner. The primary fuel to be used will be an Ohio bituminous coal having a nominal sulfur content of 3 percent or greater.

  5. LIMB Demonstration Project Extension

    SciTech Connect

    Not Available

    1989-11-15

    The basic goal of the Limestone Injection Mitigation Burner (LIMB) demonstration is to extend LIMB technology development to a full- scale application on a representative wall-fired utility boiler. The successful retrofit of LIMB to an existing boiler is expected to demonstrate that (a) reductions of 50 percent or greater in SO{sub x} and NO{sub x} emissions can be achieved at a fraction of the cost of add-on FGD systems, (b) boiler reliability, operability, and steam production can be maintained at levels existing prior to LIMB retrofit, and (c) technical difficulties attributable to LIMB operation, such as additional slagging and fouling, changes in ash disposal requirements, and an increased particulate load, can be resolved in a cost-effective manner. The primary fuel to be used will be an Ohio bituminous coal having a nominal sulfur content of 3 percent or greater.

  6. LIMB Demonstration Project Extension

    SciTech Connect

    Not Available

    1989-03-15

    The basic goal of the Limestone Injection Multistage Burner (LIMB) demonstration is to extend LIMB technology development to a full- scale application on a representative wall-fired utility boiler. The successful retrofit of LIMB to an existing boiler is expected to demonstrate that (a) reductions of 50 percent or greater in SO{sub x} and NO{sub x} emissions can be achieved at a fraction of the cost of add-on FGD systems, (b) boiler reliability, operability, and steam production can be maintained at levels existing prior to LIMB retrofit, and (c) technical difficulties attributable to LIMB operation, such as additional slagging and fouling, changes in ash disposal requirements, and an increased particulate load, can be resolved in a cost-effective manner. The primary fuel to be used will be an Ohio bituminous coal having a nominal sulfur content of 3 percent or greater.

  7. LIMB Demonstration Project Extension

    SciTech Connect

    Not Available

    1988-12-15

    The basic goal of the Limestone Injection Multistage Burner (LIMB) demonstration is to extend LIMB technology development to a full- scale application on a representative wall-fired utility boiler. The successful retrofit of LIMB to an existing boiler is expected to demonstrate that (a) reductions of 50 percent or greater in SO{sub x} and NO{sub x} emissions can be achieved at a fraction of the cost of add-on FGD systems, (b) boiler reliability, operability, and steam production can be maintained at levels existing prior to LIMB retrofit, and (c) technical difficulties attributable to LIMB operation, such as additional slagging and fouling, changes in ash disposal requirements, and an increased particulate load, can be resolved in a cost-effective manner. The primary fuel to be used will be an Ohio bituminous coal having a nominal sulfur content of 3 percent or greater.

  8. Automatic recognition of piping system from laser scanned point clouds using normal-based region growing

    NASA Astrophysics Data System (ADS)

    Kawashima, K.; Kanai, S.; Date, H.

    2013-10-01

    In recent years, renovations of plant equipment have been more frequent, and constructing 3D as-built models of existing plants from large-scale laser scanned data is expected to make rebuilding processes more efficient. However, laser scanned data consists of enormous number of points, captures tangled objects and includes a high noise level, so that the manual reconstruction of a 3D model is very time-consuming. Among plant equipment, piping systems especially account for the greatest proportion. Therefore, the purpose of this research was to propose an algorithm which can automatically recognize a piping system from large-scale laser scanned data of plants. The straight portion of pipes, connecting parts and connection relationship of the piping system can be automatically recognized. Normal-based region growing enables the extraction of points on the piping system. Eigen analysis of the normal tensor and cylinder surface fitting allows the algorithm to recognize portions of straight pipes. Tracing the axes of the piping system and interpolation of the axes can derive connecting parts and connection relationships between elements of the piping system. The algorithm was applied to large-scale scanned data of an oil rig and a chemical plant. The recognition rate of straight pipes, elbows, junctions achieved 93%, 88% and 87% respectively.

  9. MEMS-based non-rotatory circumferential scanning optical probe for endoscopic optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Xu, Yingshun; Singh, Janak; Siang, Teo Hui; Ramakrishna, Kotlanka; Premchandran, C. S.; Sheng, Chen Wei; Kuan, Chuah Tong; Chen, Nanguang; Olivo, Malini C.; Sheppard, Colin J. R.

    2007-07-01

    In this paper, we present a non-rotatory circumferential scanning optical probe integrated with a MEMS scanner for in vivo endoscopic optical coherence tomography (OCT). OCT is an emerging optical imaging technique that allows high resolution cross-sectional imaging of tissue microstructure. To extend its usage to endoscopic applications, a miniaturized optical probe based on Microelectromechanical Systems (MEMS) fabrication techniques is currently desired. A 3D electrothermally actuated micromirror realized using micromachining single crystal silicon (SCS) process highlights its very large angular deflection, about 45 degree, with low driving voltage for safety consideration. The micromirror is integrated with a GRIN lens into a waterproof package which is compatible with requirements for minimally invasive endoscopic procedures. To implement circumferential scanning substantially for diagnosis on certain pathological conditions, such as Barret's esophagus, the micromirror is mounted on 90 degree to optical axis of GRIN lens. 4 Bimorph actuators that are connected to the mirror on one end via supporting beams and springs are selected in this micromirror design. When actuators of the micromirror are driven by 4 channels of sinusoidal waveforms with 90 degree phase differences, beam focused by a GRIN is redirected out of the endoscope by 45 degree tilting mirror plate and achieve circumferential scanning pattern. This novel driving method making full use of very large angular deflection capability of our micromirror is totally different from previously developed or developing micromotor-like rotatory MEMS device for circumferential scanning.

  10. Infrared micro-scanning error compensation algorithm based on edge location

    NASA Astrophysics Data System (ADS)

    Gao, Hang; Chen, Qian; Sui, Xiubao

    2015-03-01

    For area-array thermal imaging devices, an essential factor affecting the system imaging quality is the sub-sampling caused by oversized discrete sampling pitch. In order to obtain higher spatial resolution, staring infrared focal plane array (IRFPA) gets multi-frame sub-sampling images by micro-scanning movement to achieve an adequate spatial sampling frequency. However, influenced by external environment and the accuracy of the scanning system itself, the relative displacement between the detector and the scene cannot be absolutely precisely controlled, but exist some error, which will affect the final performance of the reconstructed high-resolution image. We analyzed the distribution of the error and then proposed an infrared micro-scanning error compensation algorithm based on edge location, which is inspired by human retina fixational eye movement pattern. It first locates the edge point in the reconstruction unit and finds the corresponding characteristic values. Later on, matches the characteristic value with the fixed templates and reorders the pixel responses in reconstruction unit utilizing the gray correlation. Finally, it compensates the error real-timely through repeated update and iteration. We apply the algorithm in video sequences acquired by 4-step infrared micro-scanning system. The experiment results show that when aligning to a static scene or stationary region in dynamic scene, the algorithm possesses good resolution enhancement effect, particularly, can improve the clarity and the accuracy of static image edge details.

  11. High frame-rate multichannel beam-scanning microscopy based on Lissajous trajectories

    PubMed Central

    Sullivan, Shane Z.; Muir, Ryan D.; Newman, Justin A.; Carlsen, Mark S.; Sreehari, Suhas; Doerge, Chris; Begue, Nathan J.; Everly, R. Michael; Bouman, Charles A.; Simpson, Garth J.

    2014-01-01

    A simple beam-scanning optical design based on Lissajous trajectory imaging is described for achieving up to kHz frame-rate optical imaging on multiple simultaneous data acquisition channels. In brief, two fast-scan resonant mirrors direct the optical beam on a circuitous trajectory through the field of view, with the trajectory repeat-time given by the least common multiplier of the mirror periods. Dicing the raw time-domain data into sub-trajectories combined with model-based image reconstruction (MBIR) 3D in-painting algorithms allows for effective frame-rates much higher than the repeat time of the Lissajous trajectory. Since sub-trajectory and full-trajectory imaging are simply different methods of analyzing the same data, both high-frame rate images with relatively low resolution and low frame rate images with high resolution are simultaneously acquired. The optical hardware required to perform Lissajous imaging represents only a minor modification to established beam-scanning hardware, combined with additional control and data acquisition electronics. Preliminary studies based on laser transmittance imaging and polarization-dependent second harmonic generation microscopy support the viability of the approach both for detection of subtle changes in large signals and for trace-light detection of transient fluctuations. PMID:25321997

  12. Design of a MEMS-based retina scanning system for biometric authentication

    NASA Astrophysics Data System (ADS)

    Woittennek, Franziska; Knobbe, Jens; Pügner, Tino; Schelinski, Uwe; Grüger, Heinrich

    2014-05-01

    There is an increasing need for reliable authentication for a number of applications such as e commerce. Common authentication methods based on ownership (ID card) or knowledge factors (password, PIN) are often prone to manipulations and may therefore be not safe enough. Various inherence factor based methods like fingerprint, retinal pattern or voice identifications are considered more secure. Retina scanning in particular offers both low false rejection rate (FRR) and low false acceptance rate (FAR) with about one in a million. Images of the retina with its characteristic pattern of blood vessels can be made with either a fundus camera or laser scanning methods. The present work describes the optical design of a new compact retina laser scanner which is based on MEMS (Micro Electric Mechanical System) technology. The use of a dual axis micro scanning mirror for laser beam deflection enables a more compact and robust design compared to classical systems. The scanner exhibits a full field of view of 10° which corresponds to an area of 4 mm2 on the retinal surface surrounding the optical disc. The system works in the near infrared and is designed for use under ambient light conditions, which implies a pupil diameter of 1.5 mm. Furthermore it features a long eye relief of 30 mm so that it can be conveniently used by persons wearing glasses. The optical design requirements and the optical performance are discussed in terms of spot diagrams and ray fan plots.

  13. An elastography method based on the scanning contact resonance of a piezoelectric cantilever

    SciTech Connect

    Fu, Ji; Li, Faxin

    2013-12-15

    Purpose: Most tissues may become significantly stiffer than their normal states when there are lesions inside. The tissue's modulus can then act as an identification parameter for clinic diagnosis of tumors or fibrosis, which leads to elastography. This study introduces a novel elastography method that can be used for modulus imaging of superficial organs. Methods: This method is based on the scanning contact-resonance of a unimorph piezoelectric cantilever. The cantilever vibrates in its bending mode with the tip pressed tightly on the sample. The contact resonance frequency of the cantilever-sample system is tracked at each scanning point, from which the sample's modulus can be derived based on a beam dynamic model and a contact mechanics model. Scanning is performed by a three-dimensional motorized stage and the whole system is controlled by a homemade software program based on LabVIEW. Results: Testing onin vitro beef tissues indicates that the fat and the muscle can be easily distinguished using this system, and the accuracy of the modulus measurement can be comparable with that of nanoindentation. Imaging on homemade gelatin phantoms shows that the depth information of the abnormalities can be qualitatively obtained by varying the pressing force. The detection limit of this elastography method is specially examined both experimentally and numerically. Results show that it can detect the typical lesions in superficial organs with the depth of several centimeters. The lateral resolution of this elastography method/system is better than 0.5 mm, and could be further enhanced by using more scanning points. Conclusions: The proposed elastography system can be regarded as a sensitive palpation robot, which may be very promising in early diagnosis of tumors in superficial organs such as breast and thyroid.

  14. Feature-Based Laser Scan Matching and Its Application for Indoor Mapping.

    PubMed

    Li, Jiayuan; Zhong, Ruofei; Hu, Qingwu; Ai, Mingyao

    2016-01-01

    Scan matching, an approach to recover the relative position and orientation of two laser scans, is a very important technique for indoor positioning and indoor modeling. The iterative closest point (ICP) algorithm and its variants are the most well-known techniques for such a problem. However, ICP algorithms rely highly on the initial guess of the relative transformation, which will reduce its power for practical applications. In this paper, an initial-free 2D laser scan matching method based on point and line features is proposed. We carefully design a framework for the detection of point and line feature correspondences. First, distinct feature points are detected based on an extended 1D SIFT, and line features are extracted via a modified Split-and-Merge algorithm. In this stage, we also give an effective strategy for discarding unreliable features. The point and line features are then described by a distance histogram; the pairs achieving best matching scores are accepted as potential correct correspondences. The histogram cluster technique is adapted to filter outliers and provide an accurate initial value of the rigid transformation. We also proposed a new relative pose estimation method that is robust to outliers. We use the lq-norm (0 < q < 1) metric in this approach, in contrast to classic optimization methods whose cost function is based on the l₂-norm of residuals. Extensive experiments on real data demonstrate that the proposed method is almost as accurate as ICPs and is initial free. We also show that our scan matching method can be integrated into a simultaneous localization and mapping (SLAM) system for indoor mapping. PMID:27517932

  15. Effective Management of Upper Limb Parkinsonian Tremor by IncobotulinumtoxinA Injections Using Sensor-based Biomechanical Patterns

    PubMed Central

    Rahimi, Fariborz; Samotus, Olivia; Lee, Jack; Jog, Mandar

    2015-01-01

    Background Focal treatment of Parkinson’s disease tremor by botulinum toxin type A incobotulinumtoxinA (BoNT-A) injections has been inadequately investigated and at best provides modest relief with significant muscle weakness. Complexity of multi-joint tremulous movements results in non-individualized dosing regimens. This 38-week open-label study used kinematic technology to guide muscle selection and improve efficacy of incobotulinumtoxinA (BoNT-A) injections for Parkinson’s disease tremor. Methods Participants (n=28) attended study visits at weeks 0, 6, 16, 22, 32, and 38, and were injected with BoNT-A at weeks 0, 16, and 32. During each visit, clinical tremor scales, the Unified Parkinson’s Disease Rating Scale (UPDRS) and the Fahn–Tolosa–Marin (FTM), and kinematic assessments were conducted. Participants performed rest and postural scripted tasks with motion sensors placed over the wrist, elbow, and shoulder joints where tremor was quantified by angular root mean square (RMS) amplitude in multiple degrees of freedom at each joint. Injection parameters were determined using the clinician’s interpretation of which muscles would contribute to the upper limb tremor biomechanics analyzed kinematically. Results Kinematic measures of tremor amplitude allowed detailed segmentation of tremor into directional components at each arm joint permitting a statistically significant decrease in mean UPDRS item 20 (rest tremor) at week 16 (p=0.006) and at week 32 (p=0.014), and in FTM tremor severity scores at week 6 (p=0.024). Ten participants perceived mild muscle weakness following the third treatment, which did not interfere with performing activities of daily living. Discussion Kinematics is a simple method for standardizing assessments and treatment of upper limb Parkinson’s disease tremor, thereby personalizing tremor therapy and optimizing the effect of BoNT-A injections for Parkinson’s disease tremor. PMID:26566459

  16. Training modalities in robot-mediated upper limb rehabilitation in stroke: a framework for classification based on a systematic review

    PubMed Central

    2014-01-01

    Robot-mediated post-stroke therapy for the upper-extremity dates back to the 1990s. Since then, a number of robotic devices have become commercially available. There is clear evidence that robotic interventions improve upper limb motor scores and strength, but these improvements are often not transferred to performance of activities of daily living. We wish to better understand why. Our systematic review of 74 papers focuses on the targeted stage of recovery, the part of the limb trained, the different modalities used, and the effectiveness of each. The review shows that most of the studies so far focus on training of the proximal arm for chronic stroke patients. About the training modalities, studies typically refer to active, active-assisted and passive interaction. Robot-therapy in active assisted mode was associated with consistent improvements in arm function. More specifically, the use of HRI features stressing active contribution by the patient, such as EMG-modulated forces or a pushing force in combination with spring-damper guidance, may be beneficial. Our work also highlights that current literature frequently lacks information regarding the mechanism about the physical human-robot interaction (HRI). It is often unclear how the different modalities are implemented by different research groups (using different robots and platforms). In order to have a better and more reliable evidence of usefulness for these technologies, it is recommended that the HRI is better described and documented so that work of various teams can be considered in the same group and categories, allowing to infer for more suitable approaches. We propose a framework for categorisation of HRI modalities and features that will allow comparing their therapeutic benefits. PMID:25012864

  17. Comparison of sEMG-Based Feature Extraction and Motion Classification Methods for Upper-Limb Movement

    PubMed Central

    Guo, Shuxiang; Pang, Muye; Gao, Baofeng; Hirata, Hideyuki; Ishihara, Hidenori

    2015-01-01

    The surface electromyography (sEMG) technique is proposed for muscle activation detection and intuitive control of prostheses or robot arms. Motion recognition is widely used to map sEMG signals to the target motions. One of the main factors preventing the implementation of this kind of method for real-time applications is the unsatisfactory motion recognition rate and time consumption. The purpose of this paper is to compare eight combinations of four feature extraction methods (Root Mean Square (RMS), Detrended Fluctuation Analysis (DFA), Weight Peaks (WP), and Muscular Model (MM)) and two classifiers (Neural Networks (NN) and Support Vector Machine (SVM)), for the task of mapping sEMG signals to eight upper-limb motions, to find out the relation between these methods and propose a proper combination to solve this issue. Seven subjects participated in the experiment and six muscles of the upper-limb were selected to record sEMG signals. The experimental results showed that NN classifier obtained the highest recognition accuracy rate (88.7%) during the training process while SVM performed better in real-time experiments (85.9%). For time consumption, SVM took less time than NN during the training process but needed more time for real-time computation. Among the four feature extraction methods, WP had the highest recognition rate for the training process (97.7%) while MM performed the best during real-time tests (94.3%). The combination of MM and NN is recommended for strict real-time applications while a combination of MM and SVM will be more suitable when time consumption is not a key requirement. PMID:25894941

  18. Comparison of sEMG-Based Feature Extraction and Motion Classification Methods for Upper-Limb Movement.

    PubMed

    Guo, Shuxiang; Pang, Muye; Gao, Baofeng; Hirata, Hideyuki; Ishihara, Hidenori

    2015-01-01

    The surface electromyography (sEMG) technique is proposed for muscle activation detection and intuitive control of prostheses or robot arms. Motion recognition is widely used to map sEMG signals to the target motions. One of the main factors preventing the implementation of this kind of method for real-time applications is the unsatisfactory motion recognition rate and time consumption. The purpose of this paper is to compare eight combinations of four feature extraction methods (Root Mean Square (RMS), Detrended Fluctuation Analysis (DFA), Weight Peaks (WP), and Muscular Model (MM)) and two classifiers (Neural Networks (NN) and Support Vector Machine (SVM)), for the task of mapping sEMG signals to eight upper-limb motions, to find out the relation between these methods and propose a proper combination to solve this issue. Seven subjects participated in the experiment and six muscles of the upper-limb were selected to record sEMG signals. The experimental results showed that NN classifier obtained the highest recognition accuracy rate (88.7%) during the training process while SVM performed better in real-time experiments (85.9%). For time consumption, SVM took less time than NN during the training process but needed more time for real-time computation. Among the four feature extraction methods, WP had the highest recognition rate for the training process (97.7%) while MM performed the best during real-time tests (94.3%). The combination of MM and NN is recommended for strict real-time applications while a combination of MM and SVM will be more suitable when time consumption is not a key requirement. PMID:25894941

  19. Development of lower limb range of motion from early childhood to adolescence in cerebral palsy: a population-based study

    PubMed Central

    Nordmark, Eva; Hägglund, Gunnar; Lauge-Pedersen, Henrik; Wagner, Philippe; Westbom, Lena

    2009-01-01

    Background The decreasing range of joint motion caused by insufficient muscle length is a common problem in children with cerebral palsy (CP), often worsening with age. In 1994 a CP register and health care programme for children with CP was initiated in southern Sweden. The aim of this study was to analyse the development of the passive range of motion (ROM) in the lower limbs during all the growth periods in relation to gross motor function and CP subtype in the total population of children with CP. Methods In total, 359 children with CP born during 1990-1999, living in the southernmost part of Sweden in the year during which they reached their third birthday and still living in the area in the year of their seventh birthday were analysed. The programme includes a continuous standardized follow-up with goniometric measurements of ROM in the lower limbs. The assessments are made by each child's local physiotherapist twice a year until 6 years of age, then once a year. In total, 5075 assessments from the CPUP database from 1994 to 1 January 2007 were analysed. Results The study showed a decreasing mean range of motion over the period 2-14 years of age in all joints or muscles measured. The development of ROM varied according to GMFCS level and CP subtype. Conclusion We found a decreasing ROM in children with CP from 2-14 years of age. This information is important for both the treatment and follow-up planning of the individual child as well as for the planning of health care programmes for all children with CP. PMID:19863779

  20. Space-based infrared scanning sensor LOS determination and calibration using star observation

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Xu, Zhan; An, Wei; Deng, Xin-Pu; Yang, Jun-Gang

    2015-10-01

    This paper provides a novel methodology for removing sensor bias from a space based infrared (IR) system (SBIRS) through the use of stars detected in the background field of the sensor. Space based IR system uses the LOS (line of sight) of target for target location. LOS determination and calibration is the key precondition of accurate location and tracking of targets in Space based IR system and the LOS calibration of scanning sensor is one of the difficulties. The subsequent changes of sensor bias are not been taking into account in the conventional LOS determination and calibration process. Based on the analysis of the imaging process of scanning sensor, a theoretical model based on the estimation of bias angles using star observation is proposed. By establishing the process model of the bias angles and the observation model of stars, using an extended Kalman filter (EKF) to estimate the bias angles, and then calibrating the sensor LOS. Time domain simulations results indicate that the proposed method has a high precision and smooth performance for sensor LOS determination and calibration. The timeliness and precision of target tracking process in the space based infrared (IR) tracking system could be met with the proposed algorithm.

  1. Model-Based Angular Scan Error Correction of an Electrothermally-Actuated MEMS Mirror.

    PubMed

    Zhang, Hao; Xu, Dacheng; Zhang, Xiaoyang; Chen, Qiao; Xie, Huikai; Li, Suiqiong

    2015-01-01

    In this paper, the actuation behavior of a two-axis electrothermal MEMS (Microelectromechanical Systems) mirror typically used in miniature optical scanning probes and optical switches is investigated. The MEMS mirror consists of four thermal bimorph actuators symmetrically located at the four sides of a central mirror plate. Experiments show that an actuation characteristics difference of as much as 4.0% exists among the four actuators due to process variations, which leads to an average angular scan error of 0.03°. A mathematical model between the actuator input voltage and the mirror-plate position has been developed to predict the actuation behavior of the mirror. It is a four-input, four-output model that takes into account the thermal-mechanical coupling and the differences among the four actuators; the vertical positions of the ends of the four actuators are also monitored. Based on this model, an open-loop control method is established to achieve accurate angular scanning. This model-based open loop control has been experimentally verified and is useful for the accurate control of the mirror. With this control method, the precise actuation of the mirror solely depends on the model prediction and does not need the real-time mirror position monitoring and feedback, greatly simplifying the MEMS control system. PMID:26690432

  2. Model-Based Angular Scan Error Correction of an Electrothermally-Actuated MEMS Mirror

    PubMed Central

    Zhang, Hao; Xu, Dacheng; Zhang, Xiaoyang; Chen, Qiao; Xie, Huikai; Li, Suiqiong

    2015-01-01

    In this paper, the actuation behavior of a two-axis electrothermal MEMS (Microelectromechanical Systems) mirror typically used in miniature optical scanning probes and optical switches is investigated. The MEMS mirror consists of four thermal bimorph actuators symmetrically located at the four sides of a central mirror plate. Experiments show that an actuation characteristics difference of as much as 4.0% exists among the four actuators due to process variations, which leads to an average angular scan error of 0.03°. A mathematical model between the actuator input voltage and the mirror-plate position has been developed to predict the actuation behavior of the mirror. It is a four-input, four-output model that takes into account the thermal-mechanical coupling and the differences among the four actuators; the vertical positions of the ends of the four actuators are also monitored. Based on this model, an open-loop control method is established to achieve accurate angular scanning. This model-based open loop control has been experimentally verified and is useful for the accurate control of the mirror. With this control method, the precise actuation of the mirror solely depends on the model prediction and does not need the real-time mirror position monitoring and feedback, greatly simplifying the MEMS control system. PMID:26690432

  3. Optimization of attenuation correction for positron emission tomography studies of thorax and pelvis using count-based transmission scans.

    PubMed

    Boellaard, R; van Lingen, A; van Balen, S C M; Lammertsma, A A

    2004-02-21

    The quality of thorax and pelvis transmission scans and therefore of attenuation correction in PET depends on patient thickness and transmission rod source strength. The purpose of the present study was to assess the feasibility of using count-based transmission scans, thereby guaranteeing more consistent image quality and more precise quantification than with fixed transmission scan duration. First, the relation between noise equivalent counts (NEC) of 10 min calibration transmission scans and rod source activity was determined over a period of 1.5 years. Second, the relation between transmission scan counts and uniform phantom diameter was studied numerically, determining the relative contribution of counts from lines of response passing through the phantom as compared with the total number of counts. Finally, the relation between patient weight and transmission scan duration was determined for 35 patients, who were scanned at the level of thorax or pelvis. After installation of new rod sources, the NEC of transmission scans first increased slightly (5%) with decreasing rod source activity and after 3 months decreased with a rate of 2-3% per month. The numerical simulation showed that the number of transmission scan counts from lines of response passing through the phantom increased with phantom diameter up to 7 cm. For phantoms larger than 7 cm, the number of these counts decreased at approximately the same rate as the total number of transmission scan counts. Patient data confirmed that the total number of transmission scan counts decreased with increasing patient weight with about 0.5% kg(-1). It can be concluded that count-based transmission scans compensate for radioactive decay of the rod sources. With count-based transmission scans, rod sources can be used for up to 1.5 years at the cost of a 50% increased transmission scan duration. For phantoms with diameters of more than 7 cm and for patients scanned at the level of thorax or pelvis, use of count-based

  4. An EST-based genome scan using 454 sequencing in the marine snail Littorina saxatilis.

    PubMed

    Galindo, J; Grahame, J W; Butlin, R K

    2010-09-01

    Genome scans have been used in the studies of ecological speciation to find genomic regions ('outlier loci') showing reduced gene flow between divergent populations/species. High-throughput sequencing ('454') offers new opportunities in this field via transcriptome sequencing. Divergent ecotypes of the marine gastropod Littorina saxatilis represent a good example of incipient ecological speciation. We performed a 454-based genome scan between H and M ecotypes of L. saxatilis from the British Isles using cDNA of pooled individuals. Allele frequencies were calculated for 2454 single nucleotide polymorphisms (SNPs), within 572 contigs, and 7% of loci were detected as outliers. Functional annotation of the contigs containing outlier SNPs showed that they included shell matrix and muscle proteins (lithostathine, mucin, titin), proteins involved in energetic metabolism (arginine kinase, NADH dehydrogenase) and reverse transcriptases. Follow-up investigations into these proteins and unannotated outliers will be a promising route in the study of ecological speciation in L. saxatilis. PMID:20695960

  5. Image motion-blur-based object's speed measurement using an interlaced scan image

    NASA Astrophysics Data System (ADS)

    Ting-Fa, Xu; Peng, Zhao

    2010-07-01

    In motion-blur-based speed measurement, a key step is the calculation of the horizontal blur extent. To perform this calculation robustly and accurately when both a defocus blur and a motion blur occur, and for a moving object with irregular shape edges, we propose a novel scheme using the image matting and transparency map. This scheme can isolate the defocus blur from the motion blur effectively, and can also calculate the horizontal blur extent accurately, regardless of the object's shape. Moreover, our novel scheme can also perform speed measurement for an object with uniformly accelerated/retarded motion (i.e. a rigid body linear motion with a constant acceleration) by using one interlaced scan CCD image. Simulation and real experiments prove that our scheme not only outperforms the current scan-line algorithm for blur extent computation, but can also perform speed measurement accurately for uniformly accelerated/retarded motion.

  6. A computational framework for cancer response assessment based on oncological PET-CT scans.

    PubMed

    Sampedro, Frederic; Escalera, Sergio; Domenech, Anna; Carrio, Ignasi

    2014-12-01

    In this work we present a comprehensive computational framework to help in the clinical assessment of cancer response from a pair of time consecutive oncological PET-CT scans. In this scenario, the design and implementation of a supervised machine learning system to predict and quantify cancer progression or response conditions by introducing a novel feature set that models the underlying clinical context is described. Performance results in 100 clinical cases (corresponding to 200 whole body PET-CT scans) in comparing expert-based visual analysis and classifier decision making show up to 70% accuracy within a completely automatic pipeline and 90% accuracy when providing the system with expert-guided PET tumor segmentation masks. PMID:25450224

  7. A laser-scanning endoscope based on polysilicon micromachined mirrors with enhanced attributes

    NASA Astrophysics Data System (ADS)

    George, Markus; Albrecht, Hansjoerg; Schurr, Marc O.; Papageorgas, Panagiotis G.; Hofmann, Ulrich; Maroulis, Dimitris; Depeursinge, Christian D.; Iakkovidis, Dimitris; Theofanous, Nikiforos; Menciassi, Arianna

    2003-10-01

    A miniaturized laser scanning endoscope is presented which makes use of three lasers to illuminate a sample with a red, a green and a blue wavelength simultaneously. Scattered light from the sample is descanned and chromatically separated into the three channels for detection and postprocessing to compose a color image. The scanning subsystem consists of two micro-electro-mechanical mirrors suitable for mass production. The endoscope head can be assembled fast and at low cost. A resolution of the order of 16 lines per mm is achieved for a working distance common in endoscopy. Considerations of the system design include the operation of the mico mirrors, the filtering of reflected light by using polarization effects and a strategy to cope with color metamery. An expert system based on a neural network was found able to analyze endoscopic images to identify suspicious lesions.

  8. An entropy-based filtering approach for airborne laser scanning data

    NASA Astrophysics Data System (ADS)

    Zeng, Zhe; Wan, Jiaxin; Liu, Hui

    2016-03-01

    Parameter-tuning is a challenging task when generating digital terrain models from airborne laser scanning (light detection and ranging, LiDAR) data. To address this issue, this paper presents a filtering method for near-infrared laser scanning data that exploits the principle of entropy maximization as the optimization objective. The proposed approach generates ground elevation of point cloud by constructing a triangulated irregular network, calculates the entropy of the elevation from different parts, and automatically separates ground and non-ground points by the principle of entropy maximization. Experimental results from different ground surfaces show that the proposed entropy-based filtering method can effectively extract bare-earth points from the point cloud without adjusting thresholds.

  9. 3-D micro surface profilometry employing novel Mirau-based lateral scanning interferometry

    NASA Astrophysics Data System (ADS)

    Chen, Liang-Chia; Le, Manh-Trung; Lin, Yi-Shiuan

    2014-09-01

    An innovative 3-D surface imaging methodology for reconstructing micro surface profiles with a long depth measuring range and a nano-scale resolution was developed using the newly developed Mirau-based lateral scanning interferometry (LSI). The current measuring field of view (FOV) of conventional white light interferometers is limited by microscopic views of the existing interferometric objectives, such as those in Michelson, Mirau or Linnik designs. Moreover, the vertical scanning operation required for acquiring volumetric interferometric data is extremely time-consuming and makes white light vertical scanning interferometry (VSI) infeasible for automatic optical inspection (AOI) of micro 3-D structures. To resolve this, a newly developed white light LSI method based on Mirau’s optical configuration was developed by controlling the tilting angle of the reference mirror in the Mirau interferometric objective. With the proposed optical configuration, the surface is inspected at a tilting angle with respect to the maximum coherence plane of the interferometric system along its lateral scanning direction when the objective lies perpendicular to the tested surface. In addition, a system calibration method was developed to establish an accurate mathematical mapping model between the object depth and the lateral axis. To evaluate the feasibility of the methodology, a calibrated step height was measured for evaluating the accuracy and repeatability. Some industrial samples, such as photon spacers and other microstructures fabricated by nano-imprinting processes, were measured to verify the actual performance on real components. It was found that the measurement repeatability was controlled less than 60 nm within one standard deviation for a maximum measurable depth of 27.21 µm.

  10. Out on a Limb: Investigating the Anatomy of Tree Limbs

    ERIC Educational Resources Information Center

    Shaw, Edward L.

    2008-01-01

    The author presents several upper elementary science activities involving tree limbs that were collected after severe weather conditions. The activities involved 3rd-grade students arranging tree limb pieces in the correct order from the trunk to the tip of the limb, measuring the pieces, determining the age of a tree limb by its rings,…

  11. Scan Line Based Road Marking Extraction from Mobile LiDAR Point Clouds.

    PubMed

    Yan, Li; Liu, Hua; Tan, Junxiang; Li, Zan; Xie, Hong; Chen, Changjun

    2016-01-01

    Mobile Mapping Technology (MMT) is one of the most important 3D spatial data acquisition technologies. The state-of-the-art mobile mapping systems, equipped with laser scanners and named Mobile LiDAR Scanning (MLS) systems, have been widely used in a variety of areas, especially in road mapping and road inventory. With the commercialization of Advanced Driving Assistance Systems (ADASs) and self-driving technology, there will be a great demand for lane-level detailed 3D maps, and MLS is the most promising technology to generate such lane-level detailed 3D maps. Road markings and road edges are necessary information in creating such lane-level detailed 3D maps. This paper proposes a scan line based method to extract road markings from mobile LiDAR point clouds in three steps: (1) preprocessing; (2) road points extraction; (3) road markings extraction and refinement. In preprocessing step, the isolated LiDAR points in the air are removed from the LiDAR point clouds and the point clouds are organized into scan lines. In the road points extraction step, seed road points are first extracted by Height Difference (HD) between trajectory data and road surface, then full road points are extracted from the point clouds by moving least squares line fitting. In the road markings extraction and refinement step, the intensity values of road points in a scan line are first smoothed by a dynamic window median filter to suppress intensity noises, then road markings are extracted by Edge Detection and Edge Constraint (EDEC) method, and the Fake Road Marking Points (FRMPs) are eliminated from the detected road markings by segment and dimensionality feature-based refinement. The performance of the proposed method is evaluated by three data samples and the experiment results indicate that road points are well extracted from MLS data and road markings are well extracted from road points by the applied method. A quantitative study shows that the proposed method achieves an average

  12. Scan Line Based Road Marking Extraction from Mobile LiDAR Point Clouds†

    PubMed Central

    Yan, Li; Liu, Hua; Tan, Junxiang; Li, Zan; Xie, Hong; Chen, Changjun

    2016-01-01

    Mobile Mapping Technology (MMT) is one of the most important 3D spatial data acquisition technologies. The state-of-the-art mobile mapping systems, equipped with laser scanners and named Mobile LiDAR Scanning (MLS) systems, have been widely used in a variety of areas, especially in road mapping and road inventory. With the commercialization of Advanced Driving Assistance Systems (ADASs) and self-driving technology, there will be a great demand for lane-level detailed 3D maps, and MLS is the most promising technology to generate such lane-level detailed 3D maps. Road markings and road edges are necessary information in creating such lane-level detailed 3D maps. This paper proposes a scan line based method to extract road markings from mobile LiDAR point clouds in three steps: (1) preprocessing; (2) road points extraction; (3) road markings extraction and refinement. In preprocessing step, the isolated LiDAR points in the air are removed from the LiDAR point clouds and the point clouds are organized into scan lines. In the road points extraction step, seed road points are first extracted by Height Difference (HD) between trajectory data and road surface, then full road points are extracted from the point clouds by moving least squares line fitting. In the road markings extraction and refinement step, the intensity values of road points in a scan line are first smoothed by a dynamic window median filter to suppress intensity noises, then road markings are extracted by Edge Detection and Edge Constraint (EDEC) method, and the Fake Road Marking Points (FRMPs) are eliminated from the detected road markings by segment and dimensionality feature-based refinement. The performance of the proposed method is evaluated by three data samples and the experiment results indicate that road points are well extracted from MLS data and road markings are well extracted from road points by the applied method. A quantitative study shows that the proposed method achieves an average

  13. The design and simulation of single detector MIR spectrometer based on MEMS scanning mirror

    NASA Astrophysics Data System (ADS)

    Zhang, Zhong-wei; Wen, Zhi-yu; Zeng, Tian-ling; Wei, Kang-lin

    2011-08-01

    Infrared (IR) spectrometers are very important optical equipments that can be used in industry, science, medicine, agriculture, biology and food safety etc., and the market is growing. However, most traditional IR spectrometers, such as Fourier transform spectrometer (FTS) that based on Michelson interferometer principle and scanning monochromator that based on grating scanning, are expensive, relative large volume, and stationary, which can't meet the requirements of specific application such as rapidity, special environment and some special samples. To overcome these drawbacks, innovatory technology-micro electro mechanical systems (MEMS) technology was used in micro IR spectrometers in the past few years. And several prototypes and products that based on several operational principles have been emerged. In this paper, a novel IR micro spectrometer which based on MEMS technology and used single element detector was presented over a wide spectral range (from 2500nm to 5000nm) in the mid infrared (MIR) wavelength regime, and the optical system of it was designed on the basis of traditional scanning monochromator principle. In the optical system, there is a highlighted characteristic that dual spherical focus mirror was used to focus the diffraction light of the diffraction grating, which improved the spectral resolution of the optical system. Finally, using Zemax optical software, three torsion angle locations were selected to simulate the optical system of the spectrometer with the slit's size 0.1mm×1mm. The simulation result indicated that in the whole wavelength range the spectral resolution of the optical system was less than 30nm, and a high accuracy MIR spectrometer with compact volume will be realized in future hopefully.

  14. Complete mouth rehabilitation after transposition osteotomy based on intraoral scanning: an experimental approach.

    PubMed

    Güth, Jan-Frederik; Edelhoff, Daniel; Ihloff, Hela; Mast, Gerson

    2014-08-01

    This article describes the surgical and prosthodontic treatment of a patient with severe dysgnathia combined with amelogenesis imperfecta. To the authors' knowledge, this is the first treatment report to describe the application of intraoral scanning for a complete mouth reconstruction. After transposition osteotomy, the treatment included the simultaneous fabrication of antagonistic computer-aided design/computer-aided manufactured (CAD/CAM) long-term interim restorations for the maxilla and mandible and the establishment of a new centric relation position and adequate vertical dimension of occlusion. Particularly in complex situations, the major advantages of intraoral scanning can be identified as an extended magnification of the 3-dimensional digital data to control the preparation and impression at the dental office. However, the presented treatment revealed some deficiencies in the digital work flow that must be rectified. In combination with high-performance polymers, the CAD/CAM technology offers a wide range of new treatment options and simplifies the fabrication of long-term interim restorations. Although in the present treatment the esthetic and functional requirements of the patient were met, no published studies of this procedure have been based on intraoral scanning, and the approach has to be considered experimental. PMID:24529842

  15. Towards simultaneous Talbot bands based optical coherence tomography and scanning laser ophthalmoscopy imaging.

    PubMed

    Marques, Manuel J; Bradu, Adrian; Podoleanu, Adrian Gh

    2014-05-01

    We report a Talbot bands-based optical coherence tomography (OCT) system capable of producing longitudinal B-scan OCT images and en-face scanning laser ophthalmoscopy (SLO) images of the human retina in-vivo. The OCT channel employs a broadband optical source and a spectrometer. A gap is created between the sample and reference beams while on their way towards the spectrometer's dispersive element to create Talbot bands. The spatial separation of the two beams facilitates collection by an SLO channel of optical power originating exclusively from the retina, deprived from any contribution from the reference beam. Three different modes of operation are presented, constrained by the minimum integration time of the camera used in the spectrometer and by the galvo-scanners' scanning rate: (i) a simultaneous acquisition mode over the two channels, useful for small size imaging, that conserves the pixel-to-pixel correspondence between them; (ii) a hybrid sequential mode, where the system switches itself between the two regimes and (iii) a sequential "on-demand" mode, where the system can be used in either OCT or SLO regimes for as long as required. The two sequential modes present varying degrees of trade-off between pixel-to-pixel correspondence and independent full control of parameters within each channel. Images of the optic nerve and fovea regions obtained in the simultaneous (i) and in the hybrid sequential mode (ii) are presented. PMID:24877006

  16. Health Literacy Environmental Scans of Community-Based Dental Clinics in Maryland

    PubMed Central

    Maybury, Catherine; Kleinman, Dushanka V.; Radice, Sarah D.; Wang, Min Qi; Child, Wendy; Rudd, Rima E.

    2014-01-01

    Objectives. We conducted health literacy environmental scans in 26 Maryland community-based dental clinics to identify institutional characteristics and provider practices that affect dental services access and dental caries education. Methods. In 2011–2012 we assessed user friendliness of the clinics including accessibility, signage, facility navigation, educational materials, and patient forms. We interviewed patients and surveyed dental providers about their knowledge and use of communication techniques. Results. Of 32 clinics, 26 participated. Implementation of the health literacy environmental scan tools was acceptable to the dental directors and provided clinic directors with information to enhance care and outreach. We found considerable variation among clinic facilities, operations, and content of educational materials. There was less variation in types of insurance accepted, no-show rates, methods of communicating with patients, and electronic health records use. Providers who had taken a communication skills course were more likely than those who had not to use recommended communication techniques. Conclusions. Our findings provide insight into the use of health literacy environmental scan tools to identify clinic and provider characteristics and practices that can be used to make dental environments more user friendly and health literate. PMID:24922128

  17. A Horn-fed Frequency Scanning Holographic Antenna Based on Generalized Law of Reflection

    PubMed Central

    Liu, Dawei; Cheng, Bo; Pan, Xiaotian; Qiao, Lifang

    2016-01-01

    A new method of designing horn-fed frequency scanning holographic antenna is proposed. The artificial surface design of holographic antenna is based on generalized law of reflection. The input admittance is utilized to construct the interference pattern of the surface which is intervened by the excitation wave and the required radiation wave. The scalar admittance unit cell which is composed of sub-wavelength metallic patch on grounded dielectric substrate is implemented to design artificial surface, and the simulation results are just as expected that the antenna can scan the beam as the frequency changes. Furthermore, a cross shaped patch printed on grounded dielectric unit cells is used to reduce the designing complexity of tensor admittance surface. At last, a frequency scanning holographic antenna with tensor admittance surface with ability of changing linear polarization excitation wave to left-hand circular polarization (LCP) radiation wave is designed and fabricated. The full-wave simulation and experimental results show well agreement and confirm the method proposed. PMID:27515782

  18. Advances in Scanning Reflectarray Antennas Based on Ferroelectric Thin Film Phase Shifters for Deep Space Communications

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R.

    2007-01-01

    Though there are a few examples of scanning phased array antennas that have flown successfully in space, the quest for low-cost, high-efficiency, large aperture microwave phased arrays continues. Fixed and mobile applications that may be part of a heterogeneous exploration communication architecture will benefit from the agile (rapid) beam steering and graceful degradation afforded by phased array antennas. The reflectarray promises greater efficiency and economy compared to directly-radiating varieties. Implementing a practical scanning version has proven elusive. The ferroelectric reflectarray, under development and described herein, involves phase shifters based on coupled microstrip patterned on Ba(x)Sr(1-x)TiO3 films, that were laser ablated onto LaAlO3 substrates. These devices outperform their semiconductor counterparts from X- through and K-band frequencies. There are special issues associated with the implementation of a scanning reflectarray antenna, especially one realized with thin film ferroelectric phase shifters. This paper will discuss these issues which include: relevance of phase shifter loss; modulo 2(pi) effects and phase shifter transient effects on bit error rate; scattering from the ground plane; presentation of a novel hybrid ferroelectric-semiconductor phase shifter; and the effect of mild radiation exposure on phase shifter performance.

  19. A Horn-fed Frequency Scanning Holographic Antenna Based on Generalized Law of Reflection.

    PubMed

    Liu, Dawei; Cheng, Bo; Pan, Xiaotian; Qiao, Lifang

    2016-01-01

    A new method of designing horn-fed frequency scanning holographic antenna is proposed. The artificial surface design of holographic antenna is based on generalized law of reflection. The input admittance is utilized to construct the interference pattern of the surface which is intervened by the excitation wave and the required radiation wave. The scalar admittance unit cell which is composed of sub-wavelength metallic patch on grounded dielectric substrate is implemented to design artificial surface, and the simulation results are just as expected that the antenna can scan the beam as the frequency changes. Furthermore, a cross shaped patch printed on grounded dielectric unit cells is used to reduce the designing complexity of tensor admittance surface. At last, a frequency scanning holographic antenna with tensor admittance surface with ability of changing linear polarization excitation wave to left-hand circular polarization (LCP) radiation wave is designed and fabricated. The full-wave simulation and experimental results show well agreement and confirm the method proposed. PMID:27515782

  20. [Phantom limb pains].

    PubMed

    Giraux, Pascal

    2015-03-01

    With the radical experience of an amputation, the adaptation of body image is often incomplete. Some people experience phantom body perceptions, often painful and difficult to treat, after the amputation of a limb. PMID:26145132

  1. MTF measurement of IRFPA based on double-knife edge scanning method

    NASA Astrophysics Data System (ADS)

    Ying, Cheng-ping; Wu, Bin; Wang, Heng-fei; Shi, Xue-shun; Liu, Hong-yuan

    2013-09-01

    Modulation transfer function (MTF) is one of the most important parameters of infrared focal plane array (IRFPA). A double-knife edge scanning method is proposed for MTF measurement of IRFPA. In this method, a double-knife edge was used as a target, and the IRFPA under test was positioned in the focal plane of the imaging optical system by a 3-axis translation stage. With an IRFPA data acquisition system, the image of the double-knife edge was restored. By scanning in the direction orthogonal to the double-knife edge image, edge spread function (ESF) curve of each pixel swept across the knife-edge image was obtained. MTF could be calculated from the subsequent fitting, differential and Fourier transformation procedures. With double-knife edge scanning, two ESF curves of double-knife edge were obtained simultaneously, and symmetry of the two ESF curves could be used to evaluate the verticality between photosensitive surface of IRFPA and optical axis of the double-knife edge imaging system. In addition, this method can be used to judge the existing of interference from outside such as vibration, stray light and electrical noise. A measurement facility for IRFPA's MTF based on double-knife edge scanning method was also established in this study. The facility is composed of double-knife edge imaging optical system, 3-axis translation stage and data acquisition system, et al. As the kernel of the facility, the double-knife edge imaging optical system mainly comprises two symmetrical parabolic mirrors coating with reflective material, and the magnification of the optical system is 1 with an operation wavelength range of (1˜14) μm.

  2. Xenopus Limb bud morphogenesis.

    PubMed

    Keenan, Samuel R; Beck, Caroline W

    2016-03-01

    Xenopus laevis, the South African clawed frog, is a well-established model organism for the study of developmental biology and regeneration due to its many advantages for both classical and molecular studies of patterning and morphogenesis. While contemporary studies of limb development tend to focus on models developed from the study of chicken and mouse embryos, there are also many classical studies of limb development in frogs. These include both fate and specification maps, that, due to their age, are perhaps not as widely known or cited as they should be. This has led to some inevitable misinterpretations- for example, it is often said that Xenopus limb buds have no apical ectodermal ridge, a morphological signalling centre located at the distal dorsal/ventral epithelial boundary and known to regulate limb bud outgrowth. These studies are valuable both from an evolutionary perspective, because amphibians diverged early from the amniote lineage, and from a developmental perspective, as amphibian limbs are capable of regeneration. Here, we describe Xenopus limb morphogenesis with reference to both classical and molecular studies, to create a clearer picture of what we know, and what is still mysterious, about this process. PMID:26404044

  3. One of the most urgent vascular circumstances: Acute limb ischemia

    PubMed Central

    Sahin, Muslum; Kirma, Cevat

    2013-01-01

    Acute limb ischemia is a sudden decrease in limb perfusion that threatens limb viability and requires urgent evaluation and management. Most of the causes of acute limb ischemia are thrombosis of a limb artery or bypass graft, embolism from the heart or a disease artery, dissection, and trauma. Assessment determines whether the limb is viable or irreversibly damaged. Prompt diagnosis and revascularization by means of catheter-based thrombolysis or thrombectomy and by surgery reduce the risk of limb loss and mortality. Amputation is performed in patients with irreversible damage. Despite urgent revascularization, amputation rate is 10%–15% in patients during hospitalization, mostly above the knee, and mortality within 1 year is 10%–15% due to the coexisting conditions. PMID:26770694

  4. Stationary scanning x-ray source based on carbon nanotube field emitters

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Yang, G.; Cheng, Y.; Gao, B.; Qiu, Q.; Lee, Y. Z.; Lu, J. P.; Zhou, O.

    2005-05-01

    We report a field emission x-ray source that can generate a scanning x-ray beam to image an object from multiple projection angles without mechanical motion. The key component of the device is a gated carbon nanotube field emission cathode with an array of electron emitting pixels that are individually addressable via a metal-oxide-semiconductor field effect transistor-based electronic circuit. The characteristics of this x-ray source are measured and its imaging capability is demonstrated. The device can potentially lead to a fast data acquisition rate for laminography and tomosynthesis with a simplified experimental setup.

  5. Determination of the smoke-plume heights and their dynamics with ground-based scanning lidar.

    PubMed

    Kovalev, V; Petkov, A; Wold, C; Urbanski, S; Hao, W M

    2015-03-10

    Lidar-data processing techniques are analyzed, which allow determining smoke-plume heights and their dynamics and can be helpful for the improvement of smoke dispersion and air quality models. The data processing algorithms considered in the paper are based on the analysis of two alternative characteristics related to the smoke dispersion process: the regularized intercept function, extracted directly from the recorded lidar signal, and the square-range corrected backscatter signal, obtained after determining and subtracting the constant offset in the recorded signal. The analysis is performed using experimental data of the scanning lidar obtained in the area of prescribed fires. PMID:25968377

  6. [Hyperspectral acquisition system for tongue inspection based on X-Y scanning galvanometer].

    PubMed

    Li, Gang; Zhao, Jing; Lin, Ling; Zhang, Bao-ju

    2011-12-01

    Hyperspectral was used for tongue inspection in the present work to resolve the problem that information of current research for tongue inspection was inadequate. A hyperspectral acquisition system based on X-Y scanning galvanometer was also proposed due to the high cost of the current hyperspectral apparatus. An experiment was made to test the ability of this system. By collecting the hyperspectral information of color pictures with size similar to the tongue, the results of experiment showed that this system can acquire more information of tongue than other methods, and this method can provide a new way for tongue inspection. PMID:22295792

  7. Stationary scanning x-ray source based on carbon nanotube field emitters

    SciTech Connect

    Zhang, J.; Yang, G.; Cheng, Y.; Gao, B.; Qiu, Q.; Lee, Y.Z.; Lu, J.P.; Zhou, O.

    2005-05-02

    We report a field emission x-ray source that can generate a scanning x-ray beam to image an object from multiple projection angles without mechanical motion. The key component of the device is a gated carbon nanotube field emission cathode with an array of electron emitting pixels that are individually addressable via a metal-oxide-semiconductor field effect transistor-based electronic circuit. The characteristics of this x-ray source are measured and its imaging capability is demonstrated. The device can potentially lead to a fast data acquisition rate for laminography and tomosynthesis with a simplified experimental setup.

  8. Intensity-level assessment of lower body plyometric exercises based on mechanical output of lower limb joints.

    PubMed

    Sugisaki, Norihide; Okada, Junichi; Kanehisa, Hiroaki

    2013-01-01

    The present study aimed to quantify the intensity of lower extremity plyometric exercises by determining joint mechanical output. Ten men (age, 27.3 ± 4.1 years; height, 173.6 ± 5.4 cm; weight, 69.4 ± 6.0 kg; 1-repetition maximum [1RM] load in back squat 118.5 ± 12.0 kg) performed the following seven plyometric exercises: two-foot ankle hop, repeated squat jump, double-leg hop, depth jumps from 30 and 60 cm, and single-leg and double-leg tuck jumps. Mechanical output variables (torque, angular impulse, power, and work) at the lower limb joints were determined using inverse-dynamics analysis. For all measured variables, ANOVA revealed significant main effects of exercise type for all joints (P < 0.05) along with significant interactions between joint and exercise (P < 0.01), indicating that the influence of exercise type on mechanical output varied among joints. Paired comparisons revealed that there were marked differences in mechanical output at the ankle and hip joints; most of the variables at the ankle joint were greatest for two-foot ankle hop and tuck jumps, while most hip joint variables were greatest for repeated squat jump or double-leg hop. The present results indicate the necessity for determining mechanical output for each joint when evaluating the intensity of plyometric exercises. PMID:23327555

  9. A systematic graph-based method for the kinematic synthesis of non-anthropomorphic wearable robots for the lower limbs

    NASA Astrophysics Data System (ADS)

    Sergi, Fabrizio; Accoto, Dino; Tagliamonte, Nevio L.; Carpino, Giorgio; Guglielmelli, Eugenio

    2011-03-01

    The choice of non-anthropomorphic kinematic solutions for wearable robots is motivated both by the necessity of improving the ergonomics of physical Human-Robot Interaction and by the chance of exploiting the intrinsic dynamical properties of the robotic structure so to improve its performances. Under these aspects, this new class of robotic solutions is potentially advantageous over the one of anthropomorphic robotic orthoses. However, the process of kinematic synthesis of non-anthropomorphic wearable robots can be too complex to be solved uniquely by relying on conventional synthesis methods, due to the large number of open design parameters. A systematic approach can be useful for this purpose, since it allows to obtain the complete list of independent kinematic solutions with desired properties. In this perspective, this paper presents a method, which allows to generalize the problem of kinematic synthesis of a non-anthropomorphic wearable robot for the assistance of a specified set of contiguous body segments. The methodology also includes two novel tests, specifically devised to solve the problem of enumeration of kinematic structures of wearable robots: the HR-isomorphism and the HR-degeneracy tests. This method has been implemented to derive the atlas of independent kinematic solutions suitable to be used for the kinematic design of a planar wearable robot for the lower limbs.

  10. Preprocessing of A-scan GPR data based on energy features

    NASA Astrophysics Data System (ADS)

    Dogan, Mesut; Turhan-Sayan, Gonul

    2016-05-01

    There is an increasing demand for noninvasive real-time detection and classification of buried objects in various civil and military applications. The problem of detection and annihilation of landmines is particularly important due to strong safety concerns. The requirement for a fast real-time decision process is as important as the requirements for high detection rates and low false alarm rates. In this paper, we introduce and demonstrate a computationally simple, timeefficient, energy-based preprocessing approach that can be used in ground penetrating radar (GPR) applications to eliminate reflections from the air-ground boundary and to locate the buried objects, simultaneously, at one easy step. The instantaneous power signals, the total energy values and the cumulative energy curves are extracted from the A-scan GPR data. The cumulative energy curves, in particular, are shown to be useful to detect the presence and location of buried objects in a fast and simple way while preserving the spectral content of the original A-scan data for further steps of physics-based target classification. The proposed method is demonstrated using the GPR data collected at the facilities of IPA Defense, Ankara at outdoor test lanes. Cylindrically shaped plastic containers were buried in fine-medium sand to simulate buried landmines. These plastic containers were half-filled by ammonium nitrate including metal pins. Results of this pilot study are demonstrated to be highly promising to motivate further research for the use of energy-based preprocessing features in landmine detection problem.

  11. 4D offline PET-based treatment verification in scanned ion beam therapy: a phantom study

    NASA Astrophysics Data System (ADS)

    Kurz, Christopher; Bauer, Julia; Unholtz, Daniel; Richter, Daniel; Stützer, Kristin; Bert, Christoph; Parodi, Katia

    2015-08-01

    At the Heidelberg Ion-Beam Therapy Center, patient irradiation with scanned proton and carbon ion beams is verified by offline positron emission tomography (PET) imaging: the {β+} -activity measured within the patient is compared to a prediction calculated on the basis of the treatment planning data in order to identify potential delivery errors. Currently, this monitoring technique is limited to the treatment of static target structures. However, intra-fractional organ motion imposes considerable additional challenges to scanned ion beam radiotherapy. In this work, the feasibility and potential of time-resolved (4D) offline PET-based treatment verification with a commercial full-ring PET/CT (x-ray computed tomography) device are investigated for the first time, based on an experimental campaign with moving phantoms. Motion was monitored during the gated beam delivery as well as the subsequent PET acquisition and was taken into account in the corresponding 4D Monte-Carlo simulations and data evaluation. Under the given experimental conditions, millimeter agreement between the prediction and measurement was found. Dosimetric consequences due to the phantom motion could be reliably identified. The agreement between PET measurement and prediction in the presence of motion was found to be similar as in static reference measurements, thus demonstrating the potential of 4D PET-based treatment verification for future clinical applications.

  12. Artifact reduction in short-scan CBCT by use of optimization-based reconstruction

    NASA Astrophysics Data System (ADS)

    Zhang, Zheng; Han, Xiao; Pearson, Erik; Pelizzari, Charles; Sidky, Emil Y.; Pan, Xiaochuan

    2016-05-01

    Increasing interest in optimization-based reconstruction in research on, and applications of, cone-beam computed tomography (CBCT) exists because it has been shown to have to potential to reduce artifacts observed in reconstructions obtained with the Feldkamp–Davis–Kress (FDK) algorithm (or its variants), which is used extensively for image reconstruction in current CBCT applications. In this work, we carried out a study on optimization-based reconstruction for possible reduction of artifacts in FDK reconstruction specifically from short-scan CBCT data. The investigation includes a set of optimization programs such as the image-total-variation (TV)-constrained data-divergency minimization, data-weighting matrices such as the Parker weighting matrix, and objects of practical interest for demonstrating and assessing the degree of artifact reduction. Results of investigative work reveal that appropriately designed optimization-based reconstruction, including the image-TV-constrained reconstruction, can reduce significant artifacts observed in FDK reconstruction in CBCT with a short-scan configuration.

  13. Drug dosage in isolated limb perfusion: evaluation of a limb volume model for extremity volume calculation

    PubMed Central

    2014-01-01

    Background Exact drug dosing in isolated limb perfusion (ILP) and infusion (ILI) is essential. We developed and evaluated a model for calculating the volume of extremities and compared this model with body weight- and height-dependent parameters. Methods The extremity was modeled by a row of coupled truncated cones. The sizes of the truncated cone bases were derived from the circumference measurements of the extremity at predefined levels (5 cm). The resulting volumes were added. This extremity volume model was correlated to the computed tomography (CT) volume data of the extremity (total limb volume). The extremity volume was also correlated with the patient’s body weight, body mass index (BMI) and ideal body weight (IBW). The no-fat CT limb volume was correlated with the circumference-measured limb volume corrected by the ideal-body-weight to actual-body-weight ratio (IBW corrected-limb-volume). Results The correlation between the CT volume and the volume measured by the circumference was high and significant. There was no correlation between the limb volume and the bare body weight, BMI or IBW. The correlation between the no-fat CT volume and IBW-corrected limb volume was high and significant. Conclusions An appropriate drug dosing in ILP can be achieved by combining the limb volume with the simple circumference measurements and the IBW to body-weight ratio. PMID:24684972

  14. Uncertainties in Recent Satellite Ozone Profile Trend Assessments (SI2N, WMO 2014): A Network-Based Assessment of Fourteen Contributing Limb and Occultation Data Records

    NASA Astrophysics Data System (ADS)

    Hubert, D.; Lambert, J.-C.; Verhoelst, T.; Granville, J.; Keppens, A.; Cortesi, U.; Degenstein, D. A.; Froidevaux, L.; Godin-Beekmann, S.; Hoppel, K. W.; Kyrola, E.; Leblanc, T.; Lichtenberg, G.; McDermid, I. S.; McElroy, C. T.; Murtagh, D.; Nakane, H.; Russell, J. M., III; Smit, H. G. J.; Stebel, K.; Steinbrecht, W.; Stubi, R.; Swart, D. P. J.; Taha, G.; Thompson, A. M.; Urban, J.; van Gijsel, J. A. E.; von der Gathen, P.; Walker, K. A.; Zawodny, J. M.

    2015-06-01

    Numerous vertical ozone profile data records collected over the past decades from space-based platforms have the potential to allow the ozone and climate communities to tackle a variety of research questions. A prime topic is the study and documentation of long-term changes in the vertical distribution of atmospheric ozone, as targeted by the recent SPARC/IO3C/IGACO-O3/NDACC Initiative (SI2N) and WMO’s ozone assessment. Such studies typically require data records with documented mutual consistency in terms of bias and long-term stability. We performed a comprehensive assessment of fourteen limb/occultation ozone profile data records, using NDACC/GAW/SHADOZ ozonesonde and NDACC lidar network data as reference standards.

  15. Chip-based nanoelectrospray ionization with Fourier transform mass spectrometric detection to screen for local anesthetics intended to mask limb sore in walking horses.

    PubMed

    Szarka, Szabolcs; Prokai, Laszlo

    2015-03-01

    We report a high-throughput chip-based nanoelectrospray ionization method coupled with Fourier transform mass spectrometry to screen for local anesthetics in samples collected by swabbing. These drugs have been used to mask pain on the limbs of walking horses after forbidden practices of soring or physical abuse. Optimized for lidocaine, the method afforded sub-ppm mass accuracy for nine local anesthetics included in the study. From doped cotton swabs, two third and all of the analytes were detected after adding 10 ng and 100 ng of each drug, respectively. Benzocaine and/or lidocaine were found on positive swab samples collected during walking horse competitions. PMID:25800188

  16. Utility of a next-generation sequencing-based gene panel investigation in German patients with genetically unclassified limb-girdle muscular dystrophy.

    PubMed

    Kuhn, Marius; Gläser, Dieter; Joshi, Pushpa Raj; Zierz, Stephan; Wenninger, Stephan; Schoser, Benedikt; Deschauer, Marcus

    2016-04-01

    Limb-girdle muscular dystrophies (LGMDs) are genetically heterogeneous and the diagnostic work-up including conventional genetic testing using Sanger sequencing remains complex and often unsatisfactory. We performed targeted sequencing of 23 LGMD-related genes and 15 genes in which alterations result in a similar phenotype in 58 patients with genetically unclassified LGMDs. A genetic diagnosis was possible in 19 of 58 patients (33 %). LGMD2A was the most common form, followed by LGMD2L and LGMD2I. In two patients, pathogenic mutations were identified in genes that are not classified as LGMD genes (glycogen branching enzyme and valosin-containing protein). Thus, a focused next-generation sequencing-based gene panel is a rather satisfactory tool for the diagnosis in unclassified LGMDs. PMID:26886200

  17. Model Based Viewpoint Planning for Terrestrial Laser Scanning from AN Economic Perspective

    NASA Astrophysics Data System (ADS)

    Wujanz, D.; Neitzel, F.

    2016-06-01

    Despite the enormous popularity of terrestrial laser scanners in the field of Geodesy, economic aspects in the context of data acquisition are mostly considered intuitively. In contrast to established acquisition techniques, such as tacheometry and photogrammetry, optimisation of the acquisition configuration cannot be conducted based on assumed object coordinates, as these would change in dependence to the chosen viewpoint. Instead, a combinatorial viewpoint planning algorithm is proposed that uses a given 3D-model as an input and simulates laser scans based on predefined viewpoints. The method determines a suitably small subset of viewpoints from which the sampled object surface is preferably large. An extension of the basic algorithm is proposed that only considers subsets of viewpoints that can be registered to a common dataset. After exemplification of the method, the expected acquisition time in the field is estimated based on computed viewpoint plans.

  18. Orbscan Evaluation of Corneal Power after Myopic PRK: Placido Disc-Based vs Scanning Slit Topography

    PubMed Central

    Rosa, Nicola; Capasso, Luigi; Minutillo, Emma; Borrelli, Maria; De Bernardo, Maddalena; Lanza, Michele

    2010-01-01

    Purpose To compare Placido disc-based and scanning slit topography in the evaluation of corneal power changes after PRK. Methods The changes in corneal power, evaluated with an Orbscan II utilizing both Placido disc-based and Scanning Slit topography, before and 1, 3 and 6 months after PRK were compared with refractive changes in 109 individuals (149 eyes) who underwent photorefractive keratectomy (PRK) with a sphero equivalent refraction, calculated at the corneal apex, ranging from -0.25 to -12 D (mean -4.58±2.54 D). Results 1,3 and 6 months refractive changes showed a good correlation with changes in BFS (r2=0.64, r2= 0.53, r2= 0.62, respectively); in Sim K's (r2= 0.77, r2= 0.8, r2= 0.78, respectively) in Mean Power 3 mm (r2= 0.81, r2= 0.88, r2= 0.87, respectively) in Mean Power 5 mm (r2= 0.68, r2= 0.78, r2= 0.78, respectively) in Anterior Mean Power 3 mm (r2= 0.88, r2= 0.85, r2= 0.85, respectively) in Anterior Mean Power 5 mm (r2= 0.75, r2= 0.7, r2= 0.75, respectively) in Total Mean Power 3 mm (r2= 0.75, r2= 0.71, r2= 0.79, respectively) in Total Mean Power 5 mm (r2= 0.75, r2= 0.71, r2= 0.78, respectively). However, all differences were statistically significant (P<0.001). Conclusion The data obtained with the scanning slit system seem to be more reliable, but need correcting factors to improve their precision.

  19. A polarization-based frequency scanning interferometer and the signal processing acceleration method based on parallel processing architecture

    NASA Astrophysics Data System (ADS)

    Lee, Seung Hyun; Kim, Min Young

    FSI system, one of the most promising optical surface measurement techniques, generally results in superior optical performance comparing with other 3-dimensional measuring methods as its hardware structure is fixed in operation and only the light frequency is scanned in a specific spectral band without vertical scanning of the target surface or the objective lens. FSI system collects a set of images of interference fringe by changing the frequency of light source. After that, it transforms intensity data of acquired image into frequency information, and calculates the height profile of target objects with the help of frequency analysis based on FFT. However, it still suffers from optical noise from target surface and relatively long processing time due to the number of images acquired in frequency scanning phase. First, a polarization-based frequency scanning interferometry (PFSI) is proposed for optical noise robustness. It consists of tunable laser for light source, λ/4 plate in front of reference mirror, λ/4 plate in front of target object, polarizing beam splitter, polarizer in front of image sensor, polarizer in front of the fiber coupled light source, λ/2 plate between PBS and polarizer of the light source. Using the proposed system, we can solve the problem low contrast of acquired fringe image by using polarization technique. Also, we can control light distribution of object beam and reference beam. Second, the signal processing acceleration method is proposed for PFSI, based on parallel processing architecture, which consists of parallel processing hardware and software such as GPU (Graphic Processing Unit) and CUDA (Compute Unified Device Architecture). As a result, the processing time reaches into tact time level of real-time processing. Finally, the proposed system is evaluated in terms of accuracy and processing speed through a series of experiment and the obtained results show the effectiveness of the proposed system and method.

  20. Development of limb volume measuring system

    NASA Technical Reports Server (NTRS)

    Bhagat, P. K.; Kadaba, P. K.

    1983-01-01

    The mechanisms underlying the reductions in orthostatic tolerance associated with weightlessness are not well established. Contradictory results from measurements of leg volume changes suggest that altered venomotor tone and reduced blood flow may not be the only contributors to orthostatic intolerance. It is felt that a more accurate limb volume system which is insensitive to environmental factors will aid in better quantification of the hemodynamics of the leg. Of the varous limb volume techniques presently available, the ultrasonic limb volume system has proven to be the best choice. The system as described herein is free from environmental effects, safe, simple to operate and causes negligible radio frequency interference problems. The segmental ultrasonic ultrasonic plethysmograph is expected to provide a better measurement of limb volume change since it is based on cross-sectional area measurements.

  1. A Novel Antibody Humanization Method Based on Epitopes Scanning and Molecular Dynamics Simulation

    PubMed Central

    Zhao, Bin-Bin; Gong, Lu-Lu; Jin, Wen-Jing; Liu, Jing-Jun; Wang, Jing-Fei; Wang, Tian-Tian; Yuan, Xiao-Hui; He, You-Wen

    2013-01-01

    1-17-2 is a rat anti-human DEC-205 monoclonal antibody that induces internalization and delivers antigen to dendritic cells (DCs). The potentially clinical application of this antibody is limited by its murine origin. Traditional humanization method such as complementarity determining regions (CDRs) graft often leads to a decreased or even lost affinity. Here we have developed a novel antibody humanization method based on computer modeling and bioinformatics analysis. First, we used homology modeling technology to build the precise model of Fab. A novel epitope scanning algorithm was designed to identify antigenic residues in the framework regions (FRs) that need to be mutated to human counterpart in the humanization process. Then virtual mutation and molecular dynamics (MD) simulation were used to assess the conformational impact imposed by all the mutations. By comparing the root-mean-square deviations (RMSDs) of CDRs, we found five key residues whose mutations would destroy the original conformation of CDRs. These residues need to be back-mutated to rescue the antibody binding affinity. Finally we constructed the antibodies in vitro and compared their binding affinity by flow cytometry and surface plasmon resonance (SPR) assay. The binding affinity of the refined humanized antibody was similar to that of the original rat antibody. Our results have established a novel method based on epitopes scanning and MD simulation for antibody humanization. PMID:24278299

  2. Multi-Hop Localization Algorithm Based on Grid-Scanning for Wireless Sensor Networks*

    PubMed Central

    Wan, Jiangwen; Guo, Xiaolei; Yu, Ning; Wu, Yinfeng; Feng, Renjian

    2011-01-01

    For large-scale wireless sensor networks (WSNs) with a minority of anchor nodes, multi-hop localization is a popular scheme for determining the geographical positions of the normal nodes. However, in practice existing multi-hop localization methods suffer from various kinds of problems, such as poor adaptability to irregular topology, high computational complexity, low positioning accuracy, etc. To address these issues in this paper, we propose a novel Multi-hop Localization algorithm based on Grid-Scanning (MLGS). First, the factors that influence the multi-hop distance estimation are studied and a more realistic multi-hop localization model is constructed. Then, the feasible regions of the normal nodes are determined according to the intersection of bounding square rings. Finally, a verifiably good approximation scheme based on grid-scanning is developed to estimate the coordinates of the normal nodes. Additionally, the positioning accuracy of the normal nodes can be improved through neighbors’ collaboration. Extensive simulations are performed in isotropic and anisotropic networks. The comparisons with some typical algorithms of node localization confirm the effectiveness and efficiency of our algorithm. PMID:22163828

  3. Bilateral control-based compensation for rotation in imaging in scan imaging systems

    NASA Astrophysics Data System (ADS)

    Tian, Dapeng; Wang, Yutang; Wang, Fuchao; Zhang, Yupeng

    2015-12-01

    Scan imaging systems rely on the rotation of a mirror to scan an image. The rotation in the resulting image must be compensated to prevent information loss. Satisfactory performance of an imaging system is difficult to achieve when employing the methods of mechanical transmission and unilateral tracking control, especially when the system suffers from nonlinear factors, disturbances, and dynamic uncertainties. This paper proposes a compensation method based on bilateral control derived from the field of haptic robots. A two-loop disturbance observer was designed to guarantee that the dynamic characteristics of the motor are close to those of the nominal model. The controllers were designed on the basis of the small gain theorem. Experiments were conducted for a comparison with the traditional unilateral control-based compensation. The comparison showed a reduction of 99.83% in the L2 norm of error, which validates the method. The proposed method improves the accuracy of compensation for rotation in imaging, and demonstrates that bilateral control has feasibility for application in various fields, including photogrammetry.

  4. Sparsity based noise removal from low dose scanning electron microscopy images

    NASA Astrophysics Data System (ADS)

    Lazar, A.; Fodor, P. S.

    2015-03-01

    Scanning electron microscopes are some of the most versatile tools for imaging materials with nanometer resolution. However, images collected at high scan rates to increase throughput and avoid sample damage, suffer from low signalto- noise ratio (SNR) as a result of the Poisson distributed shot noise associated with the electron production and interaction with the surface imaged. The signal is further degraded by additive white Gaussian noise (AWGN) from the detection electronics. In this work, denoising frameworks are applied to this type of images, taking advantage of their sparsity character, along with a methodology for determining the AWGN. A variance stabilization technique is applied to the raw data followed by a patch-based denoising algorithm. Results are presented both for images with known levels of mixed Poisson-Gaussian noise, and for raw images. The quality of the image reconstruction is assessed based both on the PSNR as well as on measures specific to the application of the data collected. These include accurate identification of objects of interest and structural similarity. High-quality results are recovered from noisy observations collected at short dwell times that avoid sample damage.

  5. Image formation properties and inverse imaging problem in aperture based scanning near field optical microscopy.

    PubMed

    Schmidt, S; Klein, A E; Paul, T; Gross, H; Diziain, S; Steinert, M; Assafrao, A C; Pertsch, T; Urbach, H P; Rockstuhl, C

    2016-02-22

    Aperture based scanning near field optical microscopes are important instruments to study light at the nanoscale and to understand the optical functionality of photonic nanostructures. In general, a detected image is affected by both the transverse electric and magnetic field components of light. The discrimination of the individual field components is challenging as these four field components are contained within two signals in the case of a polarization resolved measurement. Here, we develop a methodology to solve the inverse imaging problem and to retrieve the vectorial field components from polarization and phase resolved measurements. Our methodology relies on the discussion of the image formation process in aperture based scanning near field optical microscopes. On this basis, we are also able to explain how the relative contributions of the electric and magnetic field components within detected images depend on the chosen probe. We can therefore also describe the influence of geometrical and material parameters of individual probes within the image formation process. This allows probes to be designed that are primarily sensitive either to the electric or magnetic field components of light. PMID:26907063

  6. Comparative adaptations of lower limb biomechanics during unilateral and bilateral landings after different neuromuscular-based ACL injury prevention protocols.

    PubMed

    Brown, Tyler N; Palmieri-Smith, Riann M; McLean, Scott G

    2014-10-01

    Potentially valuable anterior cruciate ligament (ACL) injury prevention strategies are lengthy, limiting training success. Shorter protocols that achieve beneficial biomechanical adaptations may improve training effectiveness. This study examined whether core stability/balance and plyometric training can modify female landing biomechanics compared with the standard neuromuscular and no training models. Forty-three females had lower limb biomechanics analyzed during unilateral and bilateral landings immediately before and after a 6-week neuromuscular or no training programs. Sagittal and frontal plane hip and knee kinematics and kinetics were submitted to 3-way repeated-measures analyses of variance to test for the main and interaction effects of training group, landing type, and testing time. Greater peak knee flexion was evident in the standard neuromuscular group following training, during both bilateral (p = 0.027) and unilateral landings (p = 0.076 and d = 0.633). The plyometric group demonstrated reduced hip adduction (p = 0.010) and greater knee flexion (p = 0.065 and d = 0.564) during bilateral landings following training. The control group had significant reduction in peak stance knee abduction moment (p = 0.003) posttraining as compared with pretraining. The current outcomes suggest that significant biomechanical changes are possible by an isolated plyometric training component. The benefits, however, may not be evident across all landing types, seemingly limited to simplistic, bilateral landings. Integrated training protocols may still be the most effective training model, currently improving knee flexion posture during both bilateral and unilateral landings following training. Future prevention efforts should implement integrated training protocols that include plyometric exercises to reduce ACL injury risk of female athletes. PMID:24714537

  7. Enabling scanning electron microscope contour-based optical proximity correction models

    NASA Astrophysics Data System (ADS)

    Weisbuch, François; Jantzen, Kenneth

    2015-04-01

    A scanning electron microscope (SEM) is the metrology tool used to accurately characterize very fine structures on wafers, usually by extracting one critical dimension (CD) per SEM image. This approach for optical proximity correction (OPC) modeling requires many measurements resulting in a lengthy cycle time for data collection, review, and cleaning, and faces reliability issues when dealing with critical two-dimensional (2-D) structures. An alternative to CD-based metrology is to use SEM image contours for OPC modeling. To calibrate OPC models with contours, reliable contours matched to traditional CD-SEM measurements are required along with a method to choose structure and site selections (number, type, and image space coverage) specific to a contour-based OPC model calibration. The potential of SEM contour model-based calibration is illustrated by comparing two contour-based models to reference models, one empirical model and a second rigorous simulation-based model. The contour-based models are as good as or better than a CD-based model with a significant advantage in the prediction of complex 2-D configurations with a reduced metrology work load.

  8. Scanning, Scanning, Everywhere.

    ERIC Educational Resources Information Center

    Ekhaml, Leticia; Myers, Brenda

    1997-01-01

    Discusses uses of scanning (process of copying or converting text, images, and objects into information that the computer can recognize and manipulate) in schools and notes possible desktop publishing projects. Describes popular scanners and ways to edit a scanned image. A sidebar gives costs and telephone numbers for nine scanners. (AEF)

  9. Comparison of Control Algorithms for a MEMS-based Adaptive Optics Scanning Laser Ophthalmoscope

    PubMed Central

    Li, Kaccie Y.; Mishra, Sandipan; Tiruveedhula, Pavan; Roorda, Austin

    2010-01-01

    We compared four algorithms for controlling a MEMS deformable mirror of an adaptive optics (AO) scanning laser ophthalmoscope. Interferometer measurements of the static nonlinear response of the deformable mirror were used to form an equivalent linear model of the AO system so that the classic integrator plus wavefront reconstructor type controller can be implemented. The algorithms differ only in the design of the wavefront reconstructor. The comparisons were made for two eyes (two individuals) via a series of imaging sessions. All four controllers performed similarly according to estimated residual wavefront error not reflecting the actual image quality observed. A metric based on mean image intensity did consistently reflect the qualitative observations of retinal image quality. Based on this metric, the controller most effective for suppressing the least significant modes of the deformable mirror performed the best. PMID:20454552

  10. Hologram-based watermarking capable of surviving print-scan process.

    PubMed

    Wang, Shuozhong; Huang, Sujuan; Zhang, Xinpeng; Wu, Wei

    2010-03-01

    We propose a watermarking scheme for hardcopy pictures based on computer-generated holography. A hologram of the watermark is produced using a conjugate-symmetric extension technique, and its spectrum is inserted into the discrete cosine transform domain of the image. Adjusting the watermark placement in a data array, a trade-off between transparency and robustness is achieved. Anticropping and the interference-resisting capability of holograms make the watermark robust against manipulations commonly performed on digital images during postprocessing, including contrast enhancement, moderate smoothing and sharpening, and, in particular, geometric transformation. Most importantly, the proposed hologram-based watermarking can withstand the printing-scanning attack and, therefore, is useful in protecting copyright of digital photographs both as electronic and hardcopy versions. PMID:20197815