WorldWideScience

Sample records for michelson doppler imager

  1. Wide Angle Michelson Doppler Imaging Interferometer (WAMDII)

    Science.gov (United States)

    Roberts, B.

    1986-01-01

    The wide angle Michelson Doppler imaging interferometer (WAMDII) is a specialized type of optical Michelson interferometer working at sufficiently long path difference to measure Doppler shifts and to infer Doppler line widths of naturally occurring upper atmospheric Gaussian line emissions. The instrument is intended to measure vertical profiles of atmospheric winds and temperatures within the altitude range of 85 km to 300 km. The WAMDII consists of a Michelson interferometer followed by a camera lens and an 85 x 106 charge coupled device photodiode array. Narrow band filters in a filter wheel are used to isolate individual line emissions and the lens forms an image of the emitting region on the charge coupled device array.

  2. WAMDII: The Wide Angle Michelson Doppler Imaging Interferometer

    Science.gov (United States)

    1992-01-01

    As part of an effort to learn more about the upper atmosphere and how it is linked to the weather experienced each day, NASA and NRCC are jointly sponsoring the Wide Angle Michelson Doppler Imaging Interferometer (WAMDII) Mission. WAMDII will measure atmospheric temperature and wind speed in the upper atmosphere. In addition to providing data on the upper atmosphere, the wind speed and temperature readings WAMDII takes will also be highly useful in developing and updating computer simulated models of the upper atmosphere. These models are used in the design and testing of equipment and software for Shuttles, satellites, and reentry vehicles. In making its wind speed and temperature measurements, WAMDII examines the Earth's airglow, a faint photochemical luminescence caused by the influx of solar ultraviolet energy into the upper atmosphere. During periods of high solar flare activity, the amount of this UV energy entering the upper atmosphere increases, and this increase may effect airglow emissions.

  3. Wide angle Michelson Doppler imaging interferometer. [measuring atmospheric emissions

    Science.gov (United States)

    Shepherd, G. G.

    1980-01-01

    The optical system, stepping control, phase and modulation depth, array detector, and directions sensor are described for a specialized type of Michelson interferometer which works at sufficiently high resolution to measure the line widths and Doppler shifts of naturally occurring atmospheric emissions. With its imaging capability, the instrument can potentially supply this data independently for each element of the 100 x 100 detector array. The experiment seeks: (1) to obtain vertical profiles of atmospheric winds and temperatures as functions of latitude by observing near the limb; (2) to acquire exploratory wind and temperature data on smaller scale structures in airglow irregularities and in auroral forms; and (3) to collaborate with other Spacelab experiments, such as barium cloud releases, in providing wind and temperature data.

  4. Dispersed single-phase-step Michelson interferometer for Doppler imaging using sunlight.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian

    2012-09-15

    A Michelson interferometer is dispersed with a fiber array-fed spectrograph, providing 59 Doppler sensing channels using sunlight in the 510-570 nm wavelength region. The interferometer operates at a single-phase-step mode, which is particularly advantageous in multiplexing and data processing compared to the phase-stepping mode of other interferometer spectrometer instruments. Spectral templates are prepared using a standard solar spectrum and simulated interferometer modulations, such that the correlation function with a measured 1D spectrum determines the Doppler shift. Doppler imaging of a rotating cylinder is demonstrated. The average Doppler sensitivity is ~12 m/s, with some channels reaching ~5 m/s.

  5. Global-Mode Analysis of Full-Disk Data from the Michelson Doppler Imager and the Helioseismic and Magnetic Imager

    Science.gov (United States)

    Larson, Timothy P.; Schou, Jesper

    2018-02-01

    Building upon our previous work, in which we analyzed smoothed and subsampled velocity data from the Michelson Doppler Imager (MDI), we extend our analysis to unsmoothed, full-resolution MDI data. We also present results from the Helioseismic and Magnetic Imager (HMI), in both full resolution and processed to be a proxy for the low-resolution MDI data. We find that the systematic errors that we saw previously, namely peaks in both the high-latitude rotation rate and the normalized residuals of odd a-coefficients, are almost entirely absent in the two full-resolution analyses. Furthermore, we find that both systematic errors seem to depend almost entirely on how the input images are apodized, rather than on resolution or smoothing. Using the full-resolution HMI data, we confirm our previous findings regarding the effect of using asymmetric profiles on mode parameters, and also find that they occasionally result in more stable fits. We also confirm our previous findings regarding discrepancies between 360-day and 72-day analyses. We further investigate a six-month period previously seen in f-mode frequency shifts using the low-resolution datasets, this time accounting for solar-cycle dependence using magnetic-field data. Both HMI and MDI saw prominent six-month signals in the frequency shifts, but we were surprised to discover that the strongest signal at that frequency occurred in the mode coverage for the low-resolution proxy. Finally, a comparison of mode parameters from HMI and MDI shows that the frequencies and a-coefficients agree closely, encouraging the concatenation of the two datasets.

  6. Performance evaluation of a thermal Doppler Michelson interferometer system.

    Science.gov (United States)

    Mani, Reza; Dobbie, Steven; Scott, Alan; Shepherd, Gordon; Gault, William; Brown, Stephen

    2005-11-20

    The thermal Doppler Michelson interferometer is the primary element of a proposed limb-viewing satellite instrument called SWIFT (Stratospheric Wind Interferometer for Transport studies). SWIFT is intended to measure stratospheric wind velocities in the altitude range of 15-45 km. SWIFT also uses narrowband tandem etalon filters made of germanium to select a line out of the thermal spectrum. The instrument uses the same technique of phase-stepping interferometry employed by the Wind Imaging Interferometer onboard the Upper Atmosphere Research Satellite. A thermal emission line of ozone near 9 microm is used to detect the Doppler shift due to winds. A test bed was set up for this instrument that included the Michelson interferometer and the etalon filters. For the test bed work, we investigate the behavior of individual components and their combination and report the results.

  7. Design of a monolithic Michelson interferometer for fringe imaging in a near-field, UV, direct-detection Doppler wind lidar.

    Science.gov (United States)

    Herbst, Jonas; Vrancken, Patrick

    2016-09-01

    The low-biased, fast, airborne, short-range, and range-resolved determination of atmospheric wind speeds plays a key role in wake vortex and turbulence mitigation strategies and would improve flight safety, comfort, and economy. In this work, a concept for an airborne, UV, direct-detection Doppler wind lidar receiver is presented. A monolithic, tilted, field-widened, fringe-imaging Michelson interferometer (FWFIMI) combines the advantages of low angular sensitivity, high thermo-mechanical stability, independence of the specific atmospheric conditions, and potential for fast data evaluation. Design and integration of the FWFIMI into a lidar receiver concept are described. Simulations help to evaluate the receiver design and prospect sufficient performance under different atmospheric conditions.

  8. Measurement of two-dimensional Doppler wind fields using a field widened Michelson interferometer.

    Science.gov (United States)

    Langille, Jeffery A; Ward, William E; Scott, Alan; Arsenault, Dennis L

    2013-03-10

    An implementation of the field widened Michelson concept has been applied to obtain high resolution two-dimensional (2D) images of low velocity (interferometer scanning mirror position is controlled to subangstrom precision with subnanometer repeatability using the multi-application low-voltage piezoelectric instrument control electronics developed by COM DEV Ltd.; it is the first implementation of this system as a phase stepping Michelson. In this paper the calibration and characterization of the Doppler imaging system is described and the planned implementation of this new technique for imaging 2D wind and irradiance fields using the earth's airglow is introduced. Observations of Doppler winds produced by a rotating wheel are reported and shown to be of sufficient precision for buoyancy wave observations in airglow in the mesopause region of the terrestrial atmosphere.

  9. First mesospheric wind images using the Michelson interferometer for airglow dynamics imaging.

    Science.gov (United States)

    Langille, J A; Ward, W E; Nakamura, T

    2016-12-10

    The Michelson interferometer for airglow dynamics imaging (MIADI) is a ground-based instrument that combines an imaging capability with the Doppler Michelson interferometry in order to remotely detect motions in the mesopause region using spectrally isolated airglow emissions: the O(S1) emission at 557.73 nm and the OH (6, 2) P1 (2) at 839.918 nm. A measurement and analysis approach has been developed that allows simultaneous images of the line-of-sight Doppler wind field and irradiance field to be obtained. A working field instrument was installed and tested at a field site outside Fredericton, NB (45.96 N, 66.65 W) during the summer of 2014. Successful measurements over a 6 h period were obtained on 31 July 2014. This paper describes the MIADI measurement and analysis approach and presents the work that has been done to extract images of the line-of-sight Doppler wind field and irradiances from these observations. The imaging capability is validated by identifying the presence of large-scale and small-scale geophysical perturbations in the images.

  10. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H.; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...... vectors. This review briefly introduces the principles behind colour Doppler imaging and describes some clinical applications. It then describes the basic components of conventional colour Doppler systems and the methods used to derive velocity information from the ultrasound signal. Next, a number of new...

  11. Ultrasonic colour Doppler imaging

    DEFF Research Database (Denmark)

    Evans, David H; Jensen, Jørgen Arendt; Nielsen, Michael Bachmann

    2011-01-01

    Ultrasonic colour Doppler is an imaging technique that combines anatomical information derived using ultrasonic pulse-echo techniques with velocity information derived using ultrasonic Doppler techniques to generate colour-coded maps of tissue velocity superimposed on grey-scale images of tissue...... anatomy. The most common use of the technique is to image the movement of blood through the heart, arteries and veins, but it may also be used to image the motion of solid tissues such as the heart walls. Colour Doppler imaging is now provided on almost all commercial ultrasound machines, and has been...

  12. Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Monolithic Interferometer Design and Test

    Science.gov (United States)

    Harlander, John M.; Englert, Christoph R.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Zastera, Vaz; Bach, Bernhard W.; Mende, Stephen B.

    2017-10-01

    The design and laboratory tests of the interferometers for the Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument which measures thermospheric wind and temperature for the NASA-sponsored Ionospheric Connection (ICON) Explorer mission are described. The monolithic interferometers use the Doppler Asymmetric Spatial Heterodyne (DASH) Spectroscopy technique for wind measurements and a multi-element photometer approach to measure thermospheric temperatures. The DASH technique and overall optical design of the MIGHTI instrument are described in an overview followed by details on the design, element fabrication, assembly, laboratory tests and thermal control of the interferometers that are the heart of MIGHTI.

  13. Near-infrared spectral imaging Michelson interferometer for astronomical applications

    Science.gov (United States)

    Wells, C. W.; Potter, A. E.; Morgan, T. H.

    1980-01-01

    The design and operation of an imaging Michelson interferometer-spectrometer used for near-infrared (0.8 micron to 2.5 microns) spectral imaging are reported. The system employs a rapid scan interferometer modified for stable low resolution (250/cm) performance and a 42 element PbS linear detector array. A microcomputer system is described which provides data acquisition, coadding, and Fourier transformation for near real-time presentation of the spectra of all 42 scene elements. The electronic and mechanical designs are discussed and telescope performance data presented.

  14. Laser doppler perfusion imaging

    International Nuclear Information System (INIS)

    Waardell, K.

    1992-01-01

    Recording of tissue perfusion is important in assessing the influence of peripheral vascular diseases on the microcirculation. This thesis reports on a laser doppler perfusion imager based on dynamic light scattering in tissue. When a low power He-Ne laser beam sequentally scans the tissue, moving blood cells generate doppler components in the back-scattered light. A fraction of this light is detected by a photodetector and converted into an electrical signal. In the processor, a signal proportional to the tissue perfusion at each measurement site is calculated and stored. When the scanning procedure is completed, a color-coded perfusion image is presented on a monitor. To convert important aspects of the perfusion image into more quantitative parameters, data analysis functions are implemented in the software. A theory describing the dependence of the distance between individual measurement points and detector on the system amplification factor is proposed and correction algorithms are presented. The performance of the laser doppler perfusion imager was evaluated using a flow simulator. A linear relationship between processor output signal and flow through the simulator was demonstrated for blood cell concentrations below 0.2%. The median sampling depth of the laser beam was simulated by a Monte Carlo technique and estimated to 235 μm. The perfusion imager has been used in the clinic to study perfusion changes in port wine stains treated with argon laser and to investigate the intensity and extension of the cutaneous axon reflex response after electrical nerve stimulation. The fact that perfusion can be visualized without touching the tissue implies elimination of sterilization problems, thus simplifying clinical investigations of perfusion in association with diagnosis and treatment of peripheral vascular diseases. 22 refs

  15. Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Instrument Design and Calibration

    Science.gov (United States)

    Englert, Christoph R.; Harlander, John M.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Stump, J. Eloise; Hancock, Jed; Peterson, James Q.; Kumler, Jay; Morrow, William H.; Mooney, Thomas A.; Ellis, Scott; Mende, Stephen B.; Harris, Stewart E.; Stevens, Michael H.; Makela, Jonathan J.; Harding, Brian J.; Immel, Thomas J.

    2017-10-01

    The Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument was built for launch and operation on the NASA Ionospheric Connection Explorer (ICON) mission. The instrument was designed to measure thermospheric horizontal wind velocity profiles and thermospheric temperature in altitude regions between 90 km and 300 km, during day and night. For the wind measurements it uses two perpendicular fields of view pointed at the Earth's limb, observing the Doppler shift of the atomic oxygen red and green lines at 630.0 nm and 557.7 nm wavelength. The wavelength shift is measured using field-widened, temperature compensated Doppler Asymmetric Spatial Heterodyne (DASH) spectrometers, employing low order échelle gratings operating at two different orders for the different atmospheric lines. The temperature measurement is accomplished by a multichannel photometric measurement of the spectral shape of the molecular oxygen A-band around 762 nm wavelength. For each field of view, the signals of the two oxygen lines and the A-band are detected on different regions of a single, cooled, frame transfer charge coupled device (CCD) detector. On-board calibration sources are used to periodically quantify thermal drifts, simultaneously with observing the atmosphere. The MIGHTI requirements, the resulting instrument design and the calibration are described.

  16. Color doppler imaging of subclavian steal phenomenon

    International Nuclear Information System (INIS)

    Cho, Nari Ya; Chung, Tae Sub; Kim, Jai Keun

    1997-01-01

    To evaluate the characteristic color doppler imaging of vertebral artery flow in the subclavian steal phenomenon. The study group consisted of eight patients with reversed vertebral artery flow proved by color Doppler imaging. We classified this flow into two groups:(1) complete reversal;(2) partial reversal, as shown by Doppler velocity waveform. Vertebral angiography was performed in six of eight patients;color Doppler imaging and angiographic findings were compared. On color Doppler imaging, all eight cases with reversed vertebral artery flow showed no signal at the proximal subclavian or brachiocephalic artery. We confirmed shunting of six cases by performing angiography from the contralateral vertebral and basilar artery to the ipsilateral vertebral artery. On the Doppler spectrum, six cases showed complete reversal and two partial reversal. On angiography, one partial reversal case showed complete occlusion of the subclavian artery with abundant collateral circulation of muscular branches of the vertebral artery. On color Doppler imaging, a reversed vertebral artery suggests the subclavian steal phenomenon. In particular, partial reversal waveform may reflect collateral circulation

  17. Optical stream-cipher-like system for image encryption based on Michelson interferometer.

    Science.gov (United States)

    Yang, Bing; Liu, Zhengjun; Wang, Bo; Zhang, Yan; Liu, Shutian

    2011-01-31

    A novel optical image encryption scheme based on interference is proposed. The original image is digitally encoded into one phase-only mask by employing an improved Gerchberg-Saxton phase retrieval algorithm together with another predefined random phase mask which serves as the encryption key. The decryption process can be implemented optically based on Michelson interferometer by using the same key. The scheme can be regarded as a stream-cipher-like encryption system, the encryption and decryption keys are the same, however the operations are different. The position coordinates and light wavelength can also be used as additional keys during the decryption. Numerical simulations have demonstrated the validity and robustness of the proposed method.

  18. ISAR imaging using the instantaneous range instantaneous Doppler method

    CSIR Research Space (South Africa)

    Wazna, TM

    2015-10-01

    Full Text Available In Inverse Synthetic Aperture Radar (ISAR) imaging, the Range Instantaneous Doppler (RID) method is used to compensate for the nonuniform rotational motion of the target that degrades the Doppler resolution of the ISAR image. The Instantaneous Range...

  19. Michelson Interferometer

    Science.gov (United States)

    Rogers, Ryan

    2007-01-01

    The Michelson Interferometer is a device used in many applications, but here it was used to measure small differences in distance, in the milli-inch range, specifically for defects in the Orbiter windows. In this paper, the method of using the Michelson Interferometer for measuring small distances is explained as well as the mathematics of the system. The coherence length of several light sources was calculated in order to see just how small a defect could be measured. Since white light is a very broadband source, its coherence length is very short and thus can be used to measure small defects in glass. After finding the front and back reflections from a very thin glass slide with ease and calculating the thickness of it very accurately, it was concluded that this system could find and measure small defects on the Orbiter windows. This report also discusses a failed attempt for another use of this technology as well as describes an area of promise for further analysis. The latter of these areas has applications for finding possible defects in Orbiter windows without moving parts.

  20. 21 CFR 892.1550 - Ultrasonic pulsed doppler imaging system.

    Science.gov (United States)

    2010-04-01

    ... system. (a) Identification. An ultrasonic pulsed doppler imaging system is a device that combines the... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasonic pulsed doppler imaging system. 892.1550... include signal analysis and display equipment, patient and equipment supports, component parts, and...

  1. Doppler time-of-flight imaging

    KAUST Repository

    Heidrich, Wolfgang

    2017-02-16

    Systems and methods for imaging object velocity are provided. In an embodiment, at least one Time-of-Flight camera is used to capture a signal representative of an object in motion over an exposure time. Illumination and modulation frequency of the captured motion are coded within the exposure time. A change of illumination frequency is mapped to measured pixel intensities of the captured motion within the exposure time, and information about a Doppler shift in the illumination frequency is extracted to obtain a measurement of instantaneous per pixel velocity of the object in motion. The radial velocity information of the object in motion can be simultaneously captured for each pixel captured within the exposure time. In one or more aspects, the illumination frequency can be coded orthogonal to the modulation frequency of the captured motion. The change of illumination frequency can correspond to radial object velocity.

  2. Doppler time-of-flight imaging

    KAUST Repository

    Heide, Felix

    2015-07-30

    Over the last few years, depth cameras have become increasingly popular for a range of applications, including human-computer interaction and gaming, augmented reality, machine vision, and medical imaging. Many of the commercially-available devices use the time-of-flight principle, where active illumination is temporally coded and analyzed on the camera to estimate a per-pixel depth map of the scene. In this paper, we propose a fundamentally new imaging modality for all time-of-flight (ToF) cameras: per-pixel velocity measurement. The proposed technique exploits the Doppler effect of objects in motion, which shifts the temporal frequency of the illumination before it reaches the camera. Using carefully coded illumination and modulation frequencies of the ToF camera, object velocities directly map to measured pixel intensities. We show that a slight modification of our imaging system allows for color, depth, and velocity information to be captured simultaneously. Combining the optical flow computed on the RGB frames with the measured metric axial velocity allows us to further estimate the full 3D metric velocity field of the scene. We believe that the proposed technique has applications in many computer graphics and vision problems, for example motion tracking, segmentation, recognition, and motion deblurring.

  3. O2 atmospheric band measurements with WINDII: Performance of a narrow band filter/wide angle Michelson combination in space

    International Nuclear Information System (INIS)

    Ward, W.E.; Hersom, C.H.; Tai, C.C.; Gault, W.A.; Shepherd, G.G.; Solheim, B.H.

    1994-01-01

    Among the emissions viewed by the Wind Imaging Interferometer (WINDII) on the Upper Atmosphere Research Satellite (UARS) are selected lines in the (0-0) transition of the O2 atmospheric band. These lines are viewed simultaneously using a narrow band filter/wide-angle Michelson interferometer combination. The narrow band filter is used to separate the lines on the CCD (spectral-spatial scanning) and the Michelson used to modulate the emissions so that winds and rotational temperatures may be measured from the Doppler shifts and relative intensities of the lines. In this report this technique will be outlined and the on-orbit behavior since launch summarized

  4. Cardiac tissue Doppler imaging in sports medicine.

    Science.gov (United States)

    Krieg, Anne; Scharhag, Jürgen; Kindermann, Wilfried; Urhausen, Axel

    2007-01-01

    The differentiation of training-induced cardiac adaptations from pathological conditions is a key issue in sports cardiology. As morphological features do not allow for a clear delineation of early stages of relevant pathologies, the echocardiographic evaluation of left ventricular function is the technique of first choice in this regard. Tissue Doppler imaging (TDI) is a relatively recent method for the assessment of cardiac function that provides direct, local measurements of myocardial velocities throughout the cardiac cycle. Although it has shown a superior sensitivity in the detection of ventricular dysfunction in clinical and experimental studies, its application in sports medicine is still rare. Besides technical factors, this may be due to a lack in consensus on the characteristics of ventricular function in relevant conditions. For more than two decades there has been an ongoing debate on the existence of a supernormal left ventricular function in athlete's heart. While results from traditional echocardiography are conflicting, TDI studies established an improved diastolic function in endurance-trained athletes with athlete's heart compared with controls.The influence of anabolic steroids on cardiac function also has been investigated by standard echocardiographic techniques with inconsistent results. The only TDI study dealing with this topic demonstrated a significantly impaired diastolic function in bodybuilders with long-term abuse of anabolic steroids compared with strength-trained athletes without abuse of anabolic steroids and controls, respectively.Hypertrophic cardiomyopathy is the most frequent cause of sudden death in young athletes. However, in its early stages, it is difficult to distinguish from athlete's heart. By means of TDI, ventricular dysfunction in hypertrophic cardiomyopathy can be disclosed even before the development of left ventricular hypertrophy. Also, a differentiation of left ventricular hypertrophy due to hypertrophic

  5. Performance evaluation of a dual fringe-imaging Michelson interferometer for air parameter measurements with a 355 nm Rayleigh-Mie lidar.

    Science.gov (United States)

    Cézard, Nicolas; Dolfi-Bouteyre, Agnès; Huignard, Jean-Pierre; Flamant, Pierre H

    2009-04-20

    A new concept of spectrum analyzer is proposed for short-range lidar measurements in airborne applications. It implements a combination of two fringe-imaging Michelson interferometers to analyze the Rayleigh-Mie spectrum backscattered by molecules and particles at 355 nm. The objective is to perform simultaneous measurements of four variables: the air speed, the air temperature and density, and the particle scattering ratio. The Cramer-Rao bounds are calculated to evaluate the best expectable measurement accuracies. The performance optimization shows that a Michelson interferometer with a path difference of 3 cm is optimal for air speed measurements in clear air. To optimize density, temperature, and scattering ratio measurements, the second interferometer should be set to a path difference of 10 cm at least; 20 cm would be better to be less sensitive to the actual Rayleigh-Brillouin line shape.

  6. Cardiac Time Intervals by Tissue Doppler Imaging M-Mode

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; de Knegt, Martina Chantal

    2016-01-01

    PURPOSE: To define normal values of the cardiac time intervals obtained by tissue Doppler imaging (TDI) M-mode through the mitral valve (MV). Furthermore, to evaluate the association of the myocardial performance index (MPI) obtained by TDI M-mode (MPITDI) and the conventional method of obtaining...

  7. Imaging doppler lidar for wind turbine wake profiling

    Science.gov (United States)

    Bossert, David J.

    2015-11-19

    An imaging Doppler lidar (IDL) enables the measurement of the velocity distribution of a large volume, in parallel, and at high spatial resolution in the wake of a wind turbine. Because the IDL is non-scanning, it can be orders of magnitude faster than conventional coherent lidar approaches. Scattering can be obtained from naturally occurring aerosol particles. Furthermore, the wind velocity can be measured directly from Doppler shifts of the laser light, so the measurement can be accomplished at large standoff and at wide fields-of-view.

  8. Doppler ultrasound imaging techniques for assessment of synovial inflammation

    Directory of Open Access Journals (Sweden)

    Filippucci E

    2013-09-01

    Full Text Available Emilio Filippucci,1 Fausto Salaffi,1 Marina Carotti,2 Walter Grassi1 1Rheumatology Department, Polytechnic University of the Marche, Ancona, Italy; 2Department of Radiology, Polytechnic University of the Marche, Ancona, Italy Abstract: Ultrasound is an evolving technique, and the rapid progress made in ultrasound technology over the past ten years has dramatically increased its range of applications in rheumatology. One of the most exciting advances is the use of Doppler ultrasound imaging in the assessment of blood flow abnormalities at the synovial tissue level in patients with chronic inflammatory arthritis. This review describes the Doppler techniques available and their main applications in patients with inflammatory arthritis, discusses the evidence supporting their use, and outlines the latest advances in hardware and software. Spectral, color, and power Doppler allow sensitive assessment of vascular abnormalities at the synovial tissue level. Use of contrast agents enhances visualization of the small synovial vessels using color or power Doppler ultrasound and allows for accurate characterization of the rheumatoid pannus. Doppler techniques represent a unique method for assessment of synovial inflammation, showing blood flow characteristics in real time. They are safe, noninvasive, cost-effective, and have high sensitivity in revealing and monitoring synovitis. However, several questions still need to be answered. In the near future, the Doppler techniques described here, together with upcoming hardware and software facilities, will be investigated further and a consensus will be reached on their feasibility and appropriate use in daily rheumatologic practice. Keywords: power and color Doppler techniques, ultrasound, contrast media, synovitis, rheumatoid arthritis

  9. Comparison of blind imaging performance of Fizeau and Michelson type arrays for a partially resolved object

    NARCIS (Netherlands)

    Van der Avoort, C.; Den Herder, J.W.; Braat, J.

    2005-01-01

    This paper compares two well-known types of interferometer arrays for optical aperture synthesis. An analytical model for both types describes the expected output, in terms of photon counts. The goal is to characterize the performance of both types of array for blind imaging of a wide-field or

  10. Doppler time-of-flight imaging

    KAUST Repository

    Heide, Felix; Wetzstein, Gordon; Hullin, Matthias; Heidrich, Wolfgang

    2015-01-01

    Over the last few years, depth cameras have become increasingly popular for a range of applications, including human-computer interaction and gaming, augmented reality, machine vision, and medical imaging. Many of the commercially-available devices

  11. Doppler time-of-flight imaging

    KAUST Repository

    Heidrich, Wolfgang; Heide, Felix; Wetzstein, Gordon; Hullin, Matthias

    2017-01-01

    Systems and methods for imaging object velocity are provided. In an embodiment, at least one Time-of-Flight camera is used to capture a signal representative of an object in motion over an exposure time. Illumination and modulation frequency

  12. Michelson and His Interferometer

    Science.gov (United States)

    Shankland, Robert S.

    1974-01-01

    Presents a brief historical account of Michelson's invention of his interferometer with some subsequent ingenious applications of its capabilities for precise measurement discussed in details, including the experiment on detrmination of the diameters for heavenly bodies. (CC)

  13. Synchronous ultrasonic Doppler imaging of magnetic microparticles in biological tissues

    Energy Technology Data Exchange (ETDEWEB)

    Pyshnyi, Michael Ph. [Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin St. 4, Moscow 119991 (Russian Federation); Kuznetsov, Oleg A. [Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin St. 4, Moscow 119991 (Russian Federation)], E-mail: kuznetsov_oa@yahoo.com; Pyshnaya, Svetlana V.; Nechitailo, Galina S.; Kuznetsov, Anatoly A. [Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin St. 4, Moscow 119991 (Russian Federation)

    2009-05-15

    We considered applicability of acoustic imaging technology for the detection of magnetic microparticles and nanoparticles inside soft biological tissues. Such particles are widely used for magnetically targeted drug delivery and magnetic hyperthermia. We developed a new method of ultrasonic synchronous tissue Doppler imaging with magnetic modulation for in vitro and in vivo detection and visualization of magnetic ultradisperse objects in soft tissues. Prototype hardware with appropriate software was produced and the method was successfully tested on magnetic microparticles injected into an excised pig liver.

  14. Synchronous ultrasonic Doppler imaging of magnetic microparticles in biological tissues

    International Nuclear Information System (INIS)

    Pyshnyi, Michael Ph.; Kuznetsov, Oleg A.; Pyshnaya, Svetlana V.; Nechitailo, Galina S.; Kuznetsov, Anatoly A.

    2009-01-01

    We considered applicability of acoustic imaging technology for the detection of magnetic microparticles and nanoparticles inside soft biological tissues. Such particles are widely used for magnetically targeted drug delivery and magnetic hyperthermia. We developed a new method of ultrasonic synchronous tissue Doppler imaging with magnetic modulation for in vitro and in vivo detection and visualization of magnetic ultradisperse objects in soft tissues. Prototype hardware with appropriate software was produced and the method was successfully tested on magnetic microparticles injected into an excised pig liver.

  15. Michelson wide-field stellar interferometry : Principles and experimental verification

    NARCIS (Netherlands)

    Montilla, I.; Pereira, S.F.; Braat, J.J.M.

    2005-01-01

    A new interferometric technique for Michelson wide-field interferometry is presented that consists of a Michelson pupil-plane combination scheme in which a wide field of view can be achieved in one shot. This technique uses a stair-shaped mirror in the intermediate image plane of each telescope in

  16. Hypercholesterolemia and Myocardial function evaluated via Tissue Doppler Imaging

    Directory of Open Access Journals (Sweden)

    Kotaru Pavan

    2009-11-01

    Full Text Available Abstract Objective To establish a link between hypercholesterolemia and myocardial dysfunction. Background Heart failure is a complex disease involving changes in systolic and diastolic function. Newer echocardiographic imaging modalities may be able to detect discreet changes in myocardial function associated with hypercholesterolemia. Therefore we sought to establish a link between hypercholesterolemia and myocardial dysfunction with tissue Doppler imaging (TDI. Methods Twenty-seven rabbits were studied: 7 were fed normal chow (group 1 and 20 a high cholesterol diet (10 with ezetimibe, 1 mg/kg/day; group 2 and 10 without, group 3. Echocardiographic images were obtained under general anesthesia. Serum cholesterol levels were obtained at baseline, 3 and 6 months and myocardial cholesterol levels measured following euthanasia. Results Doppler measurements, including E/A, E'/A' and S' were significantly lower in group 3 compared to both groups 1 and 2 but no significant differences were noted in chamber sizes or ejection fraction among the groups. Average serum cholesterol was higher in group 3 compared to groups 1 and 2 respectively (495 ± 305 mg/dl vs. 114 ± 95 mg/dl and 87 ± 37 mg/dl; p 2 = 0.17 p = 0.04, r2 = 0.37 p = 0.001 and r2 = 0.24 p = 0.01. Conclusion Cholesterol load in the serum and myocardium was significantly associated with decreased systolic and diastolic function by TDI. Moreover, lipid lowering was protective.

  17. Michelson interferometer based spatial phase shift shearography.

    Science.gov (United States)

    Xie, Xin; Yang, Lianxiang; Xu, Nan; Chen, Xu

    2013-06-10

    This paper presents a simple spatial phase shift shearography based on the Michelson interferometer. The Michelson interferometer based shearographic system has been widely utilized in industry as a practical nondestructive test tool. In the system, the Michelson interferometer is used as a shearing device to generate a shearing distance by tilting a small angle in one of the two mirrors. In fact, tilting the mirror in the Michelson interferometer also generates spatial frequency shift. Based on this feature, we introduce a simple Michelson interferometer based spatial phase shift shearography. The Fourier transform (FT) method is applied to separate the spectrum on the spatial frequency domain. The phase change due to the loading can be evaluated using a properly selected windowed inverse-FT. This system can generate a phase map of shearography by using only a single image. The effects of shearing angle, spatial resolution of couple charge device camera, and filter methods are discussed in detail. The theory and the experimental results are presented.

  18. Albert Abraham Michelson

    Indian Academy of Sciences (India)

    Some experiments change the face of a subject, and some experiments do that many times over. Albert Michelson built his interferometer in order to determine the effect of Earth's rotation on the speed of light. The null result supported the crucial assumption in Einstein's special theory of relativity and was the final nail in the ...

  19. Adaptation of Dunn Solar Telescope for Jovian Doppler spectro imaging

    Science.gov (United States)

    Underwood, Thomas A.; Voelz, David; Schmider, François-Xavier; Jackiewicz, Jason; Dejonghe, Julien; Bresson, Yves; Hull, Robert; Goncalves, Ivan; Gualme, Patrick; Morand, Frédéric; Preis, Olivier

    2017-09-01

    This paper describes instrumentation used to adapt the Dunn Solar Telescope (DST) located on Sacramento Peak in Sunspot, NM for observations using the Doppler Spectro Imager (DSI). The DSI is based on a Mach-Zehnder interferometer and measures the Doppler shift of solar lines allowing for the study of atmospheric dynamics of giant planets and the detection of their acoustic oscillations. The instrumentation is being designed and built through a collaborative effort between a French team from the Observatoire de la Cote d'Azur (OCA) that designed the DSI and a US team at New Mexico State University (NMSU). There are four major components that couple the DSI to the DST: a guider/tracker, fast steering mirror (FSM), pupil stabilizer and transfer optics. The guider/tracker processes digital video to centroid-track the planet and outputs voltages to the DST's heliostat controls. The FSM removes wavefront tip/tilt components primarily due to turbulence and the pupil stabilizer removes any slow pupil "wander" introduced by the telescope's heliostat/turret arrangement. The light received at a science port of the DST is sent through the correction and stabilization components and into the DSI. The FSM and transfer optics designs are being provided by the OCA team and serve much the same functions as they do for other telescopes at which DSI observations have been conducted. The pupil stabilization and guider are new and are required to address characteristics of the DST.

  20. Color-flow Doppler imaging in suspected extremity venous thrombosis

    International Nuclear Information System (INIS)

    Foley, W.D.; Middleton, W.D.; Lawson, T.L.; Hinson, G.W.; Puller, D.R.

    1987-01-01

    Color-flow Doppler imaging (CFDI) (Quanatum, 5 and 7.5 MHz, linear array) has been performed on 23 extremities (nine positive for venous thrombosis, 14 negative) with venographic correlation. CFDI criteria evaluated were venous color-flow respiratory variation, augmentation, compressibility, valve competence, and intraluminal echogenic filling defects. Both CFDI and venography were evaluated independently and prospectively. CFDI and venography agreed in all six cases of femoral vein thrombosis and eight of nine cases of popliteal vein thrombosis. CFDI was negative in one instance of recanalized popliteal vein thrombosis. Recanalized femoral vein thrombosis was documented in three patients by CFDI when the vein was nonopacified on conventional venography. CFDI provides a rapid and accurate assessment of the femoral popliteal venous system and can distinguish an occluded from a recanalized thrombus. Initial experience with auxiliary subclavian venous thrombus has produced equally accurate results

  1. Laser Doppler perfusion imaging with a complimentary metal oxide semiconductor image sensor

    NARCIS (Netherlands)

    Serov, Alexander; Steenbergen, Wiendelt; de Mul, F.F.M.

    2002-01-01

    We utilized a complimentary metal oxide semiconductor video camera for fast f low imaging with the laser Doppler technique. A single sensor is used for both observation of the area of interest and measurements of the interference signal caused by dynamic light scattering from moving particles inside

  2. The image of urachus adenocarcinoma on Doppler ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Oyar, Orhan E-mail: o_oyar@hotmail.com; Yesildag, Ahmet; Gulsoy, Ufuk Kemal; Perk, Hakki

    2002-10-01

    Malignant urachal lesions are exceedingly rare and occur predominantly in adult life. In this case report, an adult patient with urachal carcinoma is presented with abdominal plain film, intravenous urography, gray-scale ultrasonography (US), Doppler US, and computed tomography (CT). Doppler US successfully showed the neovascularity with low resistive index value in the urachus tumor. We believe that Doppler US examination is helpful in the differential diagnosis of urachal carcinoma.

  3. AMI: Augmented Michelson Interferometer

    Science.gov (United States)

    Furió, David; Hachet, Martin; Guillet, Jean-Paul; Bousquet, Bruno; Fleck, Stéphanie; Reuter, Patrick; Canioni, Lionel

    2015-10-01

    Experiments in optics are essential for learning and understanding physical phenomena. The problem with these experiments is that they are generally time consuming for both their construction and their maintenance, potentially dangerous through the use of laser sources, and often expensive due to high technology optical components. We propose to simulate such experiments by way of hybrid systems that exploit both spatial augmented reality and tangible interaction. In particular, we focus on one of the most popular optical experiments: the Michelson interferometer. In our approach, we target a highly interactive system where students are able to interact in real time with the Augmented Michelson Interferometer (AMI) to observe, test hypotheses and then to enhance their comprehension. Compared to a fully digital simulation, we are investigating an approach that benefits from both physical and virtual elements, and where the students experiment by manipulating 3D-printed physical replicas of optical components (e.g. lenses and mirrors). Our objective is twofold. First, we want to ensure that the students will learn with our simulator the same concepts and skills that they learn with traditional methods. Second, we hypothesis that such a system opens new opportunities to teach optics in a way that was not possible before, by manipulating concepts beyond the limits of observable physical phenomena. To reach this goal, we have built a complementary team composed of experts in the field of optics, human-computer interaction, computer graphics, sensors and actuators, and education science.

  4. Quaternion-based transformation for extraction of image-generating Doppler for ISAR

    CSIR Research Space (South Africa)

    Abdul Gaffar, MY

    2008-10-01

    Full Text Available contributing motion that is useful to the ISAR imaging process; the contributing motion consists of the Doppler generating axis and the effective angle of rotation. This letter presents a quaternion-based transformation that converts measured attitude...

  5. Prognostic value of tissue Doppler imaging for predicting ventricular arrhythmias and cardiovascular mortality in ischaemic cardiomyopathy

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Olsen, Flemming Javier; Storm, Katrine

    2016-01-01

    AIMS: Only 30% of patients receiving an implantable cardioverter defibrillator (ICD) for primary prevention receive appropriately therapy. We sought to investigate the value of tissue Doppler imaging (TDI) to predict ventricular tachycardia (VT), ventricular fibrillation (VF), and cardiovascular...

  6. Mariner 9 Michelson interferometer.

    Science.gov (United States)

    Hanel, R.; Schlachman, B.; Rodgers, D.; Breihan, E.; Bywaters, R.; Chapman, F.; Rhodes, M.; Vanous, D.

    1972-01-01

    The Michelson interferometer on Mariner 9 measures the thermal emission spectrum of Mars between 200 and 2000 per cm (between 5 and 50 microns) with a spectral resolution of 2.4 per cm in the apodized mode. A noise equivalent radiance of 0.5 x 10 to the minus 7th W/sq cm/ster/cm is deduced from data recorded in orbit around Mars. The Mariner interferometer deviates in design from the Nimbus 3 and 4 interferometers in several areas, notably, by a cesium iodide beam splitter and certain aspects of the digital information processing. Special attention has been given to the problem of external vibration. The instrument performance is demonstrated by calibration data and samples of Mars spectra.

  7. Guided magnonic Michelson interferometer.

    Science.gov (United States)

    Ahmed, Muhammad H; Jeske, Jan; Greentree, Andrew D

    2017-01-30

    Magnonics is an emerging field with potential applications in classical and quantum information processing. Freely propagating magnons in two-dimensional media are subject to dispersion, which limits their effective range and utility as information carriers. We show the design of a confining magnonic waveguide created by two surface current carrying wires placed above a spin-sheet, which can be used as a primitive for reconfigurable magnonic circuitry. We theoretically demonstrate the ability of such guides to counter the transverse dispersion of the magnon in a spin-sheet, thus extending the range of the magnon. A design of a magnonic directional coupler and controllable Michelson interferometer is shown, demonstrating its utility for information processing tasks.

  8. Michelson interferometer for measuring temperature

    OpenAIRE

    Xie, Dong; Xu, Chunling; wang, Anmin

    2016-01-01

    We investigate that temperature can be measured by a modified Michelson interferometer, where at least one reflected mirror is replaced by a thermalized sample. Both of two mirrors replaced by the corresponding two thermalized samples can help to approximatively improve the resolution of temperature up to twice than only one mirror replaced by a thermalized sample. For further improving the precision, a nonlinear medium can be employed. The Michelson interferometer is embedded in a gas displa...

  9. Endosonographic and color doppler flow imaging alterations observed within irradiated rectal cancer

    International Nuclear Information System (INIS)

    Alexander, Archie A.; Palazzo, Juan P.; Ahmad, Neelofur R.; Liu, J.-B.; Forsberg, Flemming; Marks, John

    1996-01-01

    Purpose: To correlate the endosonographic and color Doppler flow imaging alterations observed in irradiated rectal cancers with the pathologic features of radiation response, and to evaluate the potential impact of altered blood flow on the integrity of the surgical anastamosis. Methods and Materials: Endosonography with color and pulsed wave Doppler was performed on 20 rectal cancer masses before and after high dose preoperative radiation (XRT). Pre- and post-XRT observations included comparing alterations in tumor size, sonographic echotexture, color Doppler flow, and pulsatility indices. Comparisons were made with pathologic findings in the irradiated specimens and with the incidence of anastomotic failure. Results: Compared to pre-XRT observations, irradiated rectal cancers decreased in size and became either mixed in echogenicity with less apparent color Doppler flow (16 of 20) or unchanged in color Doppler flow and echotexture (4 of 20). Those with less flow (16 of 20) were imaged later (mean = 90.2 ± 12.1 days) than those without change in color Doppler flow (mean = 21.7 ± 2.7 days). Pathologically, the group of four without change in color Doppler signal had features of acute inflammation which were not observed in 16 of 20 imaged later. Based on pulsatility index measurements, both high and low resistance vessels were detected and confirmed by immunohistochemical staining, and features of postradiation obliterative vasculitis were observed. Only one primary anastomosis in 14 patients with decreased flow failed. Conclusions: The sonographic and color Doppler flow imaging alterations observed within irradiated rectal cancer correlated with changes of postradiation obliterative vasculitis. The apparent diminished local blood flow within high and low resistance vessels post-XRT did not result in an increased incidence of anastomotic failures

  10. High-frequency dual mode pulsed wave Doppler imaging for monitoring the functional regeneration of adult zebrafish hearts

    OpenAIRE

    Kang, Bong Jin; Park, Jinhyoung; Kim, Jieun; Kim, Hyung Ham; Lee, Changyang; Hwang, Jae Youn; Lien, Ching-Ling; Shung, K. Kirk

    2015-01-01

    Adult zebrafish is a well-known small animal model for studying heart regeneration. Although the regeneration of scars made by resecting the ventricular apex has been visualized with histological methods, there is no adequate imaging tool for tracking the functional recovery of the damaged heart. For this reason, high-frequency Doppler echocardiography using dual mode pulsed wave Doppler, which provides both tissue Doppler (TD) and Doppler flow in a same cardiac cycle, is developed with a 30 ...

  11. Phylloedes tumor of breast: findings at mammography, sonography and color Doppler imaging

    International Nuclear Information System (INIS)

    Park, Kun Choon; Ahn, Sei Hyun; Kim, Young Hwan; Choi, Hye Yong; Baek, Seung Yon; Yoon, Jeong Hyun

    1994-01-01

    The phylloides tumor of the breast is rare. the purposes of this study were to find the characteristic findings at mammography, sonography, and color Doppler imaging and to evaluate the usefulness of color Doppler study as an additional modality in the diagnosis of phylloides tumor and differentiation between benign and malignant varieties. Eight cases, who were pathologically proven as pylloides tumors, were retrospectively studied. The findings at histologic examination suggested benign in five, malignantin two, and borderline in one. We analyzed the mammograms of all eight patients and sonogram and color Doppler images of four patients. Phylloides tumors were seen as dense masses with lobulated margins in mammograms. On sonography, they showed relatively well-defined masses with in homogenous internal echo pattern and central echogenic areas. They were characterized by the presence of arterial and venous flows in the center and periphery of the lesion on color Doppler imaging and spectral analysis. We conclude that mammographic, sonographic and even color Doppler findings are not predictive of benign or malignant nature of the phylloides tumor. However, mammography and sonography with color Doppler interrogation are helpful in the diagnosis of phylloides tumor

  12. Angle-corrected imaging transcranial doppler sonography versus imaging and nonimaging transcranial doppler sonography in children with sickle cell disease.

    Science.gov (United States)

    Krejza, J; Rudzinski, W; Pawlak, M A; Tomaszewski, M; Ichord, R; Kwiatkowski, J; Gor, D; Melhem, E R

    2007-09-01

    Nonimaging transcranial Doppler sonography (TCD) and imaging TCD (TCDI) are used for determination of the risk of stroke in children with sickle cell disease (SCD). The purpose was to compare angle-corrected, uncorrected TCDI, and TCD blood flow velocities in children with SCD. A total of 37 children (mean age, 7.8 +/- 3.0 years) without intracranial arterial narrowing determined with MR angiography, were studied with use of TCD and TCDI at the same session. Depth of insonation and TCDI mean velocities with and without correction for the angle of insonation in the terminal internal carotid artery (ICA) and middle (MCA), anterior (ACA), and posterior (PCA) cerebral arteries were compared with TCD velocities with use of a paired t test. Two arteries were not found on TCDI compared with 15 not found on TCD. Average angle of insonation in the MCA, ACA, ICA, and PCA was 31 degrees , 44 degrees , 25 degrees , and 29 degrees , respectively. TCDI and TCD mean depth of insonation for all arteries did not differ significantly; however, individual differences varied substantially. TCDI velocities were significantly lower than TCD velocities, respectively, for the right and left sides (mean +/- SD): MCA, 106 +/- 22 cm/s and 111 +/- 33 cm/s versus 130 +/- 19 cm/s and 134 +/- 26 cm/s; ICA, 90 +/- 14 cm/s and 98 +/- 27 cm/s versus 117 +/- 18 cm/s and 119 +/- 23 cm/s; ACA, 74 +/- 24 cm/s and 88 +/- 25 cm/s versus 105 +/- 23 cm/s and 105 +/- 31 cm/s; and PCA, 84 +/- 27 cm/s and 82 +/- 21 cm/s versus 95 +/- 23 cm/s and 94 +/- 20 cm/s. TCD and angle-corrected TCDI velocities were not statistically different except for higher angle-corrected TCDI values in the left ACA and right PCA. TCD velocities are significantly higher than TCDI velocities but are not different from the angle-corrected TCDI velocities. TCDI identifies the major intracranial arteries more effectively than TCD.

  13. Michelson Interferometer (MINT)

    Science.gov (United States)

    Lacis, Andrew; Carlson, Barbara

    1993-01-01

    MINT is a Michelson interferometer designed to measure the thermal emission from the earth at high spectral resolution (2/cm) over a broad spectral range (250-1700/cm, 6-40 mu m) with contiguous 3-pixel wide (12 mrad, 8 km field of view) along-track sampling. MINT is particularly well suited for monitoring cloud properties (cloud cover, effective temperature, optical thickness, ice/water phase, and effective particle size) both day and night, as well as tropospheric water vapor, ozone, and temperature. The key instrument characteristics that make MINT ideally suited for decadal monitoring purposes are: high wavelength to wavelength precision across the full IR spectrum with high spectral resolution; space-proven long-term durability and calibration stability; and small size, low cost, low risk instrument incorporating the latest detector and electronics technology. MINT also incorporates simplicity in design and operation by utilizing passively cooled DTGS detectors and nadir viewing geometry (with target motion compensation). MINT measurement objectives, instrument characteristics, and key advantages are summarized in this paper.

  14. The Assessment of Left Ventricular Time-Varying Radius Using Tissue Doppler Imaging

    Directory of Open Access Journals (Sweden)

    Fardin Mirbolouk

    2012-03-01

    Full Text Available Background: Left ventricular twist/torsion is believed to be a sensitive indicator of systolic and diastolic performance. To obtain circumferential rotation using tissue Doppler imaging, we need to estimate the time-varying radius of the left ventricle throughout the cardiac cycle to convert the tangential velocity into angular velocity. Objectives: The aim of this study was to investigate accuracy of measured LV radius using tissue Doppler imaging throughout the cardiac cycle compared to two-dimensional (2D imaging. Methods: A total of 35 subjects (47±12 years old underwent transthoracic echocardiographic standard examinations. Left ventricular radius during complete cardiac cycle measured using tissue Doppler and 2D-imaging at basal and apical short axis levels. For this reason, the 2D-images and velocity-time data derived and transferred to a personal computer for off-line analysis. 2D image frames analyzed via a program written in the MATLAB software. Velocity-time data from anteroseptal at basal level (or anterior wall at apical level and posterior walls transferred to a spreadsheet Excel program for the radius calculations. Linear correlation and Bland-Altman analysis were calculated to assess the relationships and agreements between the tissue Doppler and 2D-measured radii throughout the cardiac cycle. Results: There was significant correlation between tissue Doppler and 2D-measured radii and the Pearson correlation coefficients were 0.84 to 0.97 (P<0.05. Bland-Altman analysis by constructing the 95% limits of agreement showed that the good agreements existed between the two methods. Conclusion: It can be concluded from our experience that the tissue Doppler imaging can reasonably estimate radius of the left ventricle throughout the cardiac cycle.

  15. Local helioseismology: three-dimensional imaging of the solar interior

    NARCIS (Netherlands)

    Gizon, L.; Birch, A.C.; Spruit, H.C.

    2010-01-01

    The Sun supports a rich spectrum of internal waves that are continuously excited by turbulent convection. The Global Oscillation Network Group (GONG) network and the SOHO/MDI (Solar and Heliospheric Observatory/Michelson Doppler Imager) space instrument provide an exceptional database of spatially

  16. Structure of a swirl-stabilized spray flame by imaging, laser Doppler velocimetry, and phase Doppler anemometry

    Science.gov (United States)

    Edwards, C. F.; Rudoff, R. C.

    1991-01-01

    Data are presented which describe the mean structure of a steady, swirl-stabilized, kerosene spray flame in the near-injector region of a research furnace. The data presented include ensemble-averaged results of schlieren, luminosity, and extinction imaging, measurement of the gas phase velocity field by laser Doppler velocimetry, and characterization of the condensed phase velocity by phase Doppler anemometry. The results of these studies define six key regions in the flame: the dense spray region; the rich, two-phase, fuel jet; the main air jet; the internal product recirculation zone; the external product recirculation zone; and the gaseous diffusion flame zone. The first five of these regions form a conical mixing layer which prepares the air and fuel for combustion. The air and fuel jets comprise the central portion of this mixing layer and are bounded on either side by the hot product gases of the internal and external recirculation zones. Entrainment of these product gases into the air/fuel streams provides the energy required to evaporate the fuel spray and initiate combustion. Intermittency of the internal recirculation and spray jet flows accounts for unexpected behavior observed in the aerodynamics of the two phases. The data reported herein are part of the database being accumulated on this spray flame for the purpose of detailed comparison with numerical modeling.

  17. Two-dimensional intraventricular flow mapping by digital processing conventional color-Doppler echocardiography images.

    Science.gov (United States)

    Garcia, Damien; Del Alamo, Juan C; Tanne, David; Yotti, Raquel; Cortina, Cristina; Bertrand, Eric; Antoranz, José Carlos; Perez-David, Esther; Rieu, Régis; Fernandez-Aviles, Francisco; Bermejo, Javier

    2010-10-01

    Doppler echocardiography remains the most extended clinical modality for the evaluation of left ventricular (LV) function. Current Doppler ultrasound methods, however, are limited to the representation of a single flow velocity component. We thus developed a novel technique to construct 2D time-resolved (2D+t) LV velocity fields from conventional transthoracic clinical acquisitions. Combining color-Doppler velocities with LV wall positions, the cross-beam blood velocities were calculated using the continuity equation under a planar flow assumption. To validate the algorithm, 2D Doppler flow mapping and laser particle image velocimetry (PIV) measurements were carried out in an atrio-ventricular duplicator. Phase-contrast magnetic resonance (MR) acquisitions were used to measure in vivo the error due to the 2D flow assumption and to potential scan-plane misalignment. Finally, the applicability of the Doppler technique was tested in the clinical setting. In vitro experiments demonstrated that the new method yields an accurate quantitative description of the main vortex that forms during the cardiac cycle (mean error for vortex radius, position and circulation). MR image analysis evidenced that the error due to the planar flow assumption is close to 15% and does not preclude the characterization of major vortex properties neither in the normal nor in the dilated LV. These results are yet to be confirmed by a head-to-head clinical validation study. Clinical Doppler studies showed that the method is readily applicable and that a single large anterograde vortex develops in the healthy ventricle while supplementary retrograde swirling structures may appear in the diseased heart. The proposed echocardiographic method based on the continuity equation is fast, clinically-compliant and does not require complex training. This technique will potentially enable investigators to study of additional quantitative aspects of intraventricular flow dynamics in the clinical setting by

  18. The Explanation of Michelson's Experiment

    International Nuclear Information System (INIS)

    Klinaku, Shukri

    2010-01-01

    In this paper we will prove that the Lorentz factor doesn't exist on the relative motion. In fact this factor is the result of a wrong calculation of Michelson. His mistake was approved by Lorentz and other physicists, including Einstein. Michelson in order to implement his idea with his interferometer in 1881, made the following mistake: he made the calculation according to the only principle of relativity which was known by physics--the Galileo principle, but he didn't faithfully apply this principle. In this paper, the principle of Galileo will be implemented exactly to Michelson's experiment and the result will show us that physics doesn't need the postulates of the year 1905.

  19. Michelson interferometer for measuring temperature

    Science.gov (United States)

    Xie, Dong; Xu, Chunling; Wang, An Min

    2017-09-01

    We investigate that temperature can be measured by a modified Michelson interferometer, where at least one reflected mirror is replaced by a thermalized sample. Both of two mirrors replaced by the corresponding two thermalized samples can help to approximatively improve the resolution of temperature up to twice than only one mirror replaced by a thermalized sample. For further improving the precision, a nonlinear medium can be employed. The Michelson interferometer is embedded in a gas displaying Kerr nonlinearity. We obtain the analytical equations and numerically calculate the precision with parameters within the reach of current technology, proving that the precision of temperature can be greatly enhanced by using a nonlinear medium. Our results show that one can create an accurate thermometer by measuring the photons in the Michelson interferometer, with no need to directly measure the population of thermalized sample.

  20. Evaluation of renal allograft rejection by Doppler sonography and MR imaging

    International Nuclear Information System (INIS)

    Steinberg, H.V.; Nelson, R.C.; Murphy, F.B.; Baumgartner, B.R.; Bourke, E.; Delaney, V.B.; Whelchel, J.B.; Bernardino, M.E.

    1986-01-01

    The authors prospectively studies the efficacy of Doppler sonography and MR imaging in evaluating renal allografts, with specific attention to transplant rejection. Based on study findings, we were unable to make a statement with respect to the appearance or accuracy of diagnosing cyclosporin toxicity or acute tubular necrosis by either modality due to concomitant rejection in the few patients so afflicted. Moreover, the ability to predict and diagnose the presence or absence of allograft rejection was not affected by different serum creatinine values. Most important, however, Doppler sonography was shown to be superior to MR imaging in evaluating for allograft rejection, as evidenced by its higher sensitivity (100% vs. 71%), specificity (88% vs. 75%), and accuracy (96% vs. 73%). Thus, because of its low cost and ease of accessibility, Doppler sonography should become the primary modality for renal transplant screening

  1. Tissue Doppler Imaging in the evaluation of abdominal aortic pulsatility: a useful tool for the neonatologist.

    Science.gov (United States)

    Valerio, Enrico; Grison, Alessandra; Capretta, Anna; Golin, Rosanna; Ferrarese, Paola; Bellettato, Massimo

    2017-03-01

    Sonographic cardiac evaluation of newborns with suspected aortic coarctation (AoC) should tend to demonstrate a good phasic and pulsatile flow and the absence of pressure gradient along a normally conformed aortic arch from the modified left parasternal and suprasternal echocardiographic views; these findings, however, may not necessarily rule out a more distal coarctation in the descending aorta. For this reason, the sonographic exam of newborns with suspected AoC should always include a Doppler evaluation of abdominal aortic blood flow from the subcostal view. Occasionally, however, a clearly pulsatile Doppler flow trace in abdominal aorta may be difficult to obtain due to the bad insonation angle existing between the probe and the vessel. In such suboptimal ultrasonic alignment situation, the use of Tissue Doppler Imaging instead of classic Doppler flow imaging may reveal a preserved aortic pulsatility by sampling the aortic wall motion induced by normal flow. We propose to take advantage of the TDI pattern as a surrogate of a normal pulsatile Doppler flow trace in abdominal aorta when the latter is difficult to obtain due to malalignment with the insonated vessel.

  2. Screening for stroke in sickle cell anemia: comparison of transcranial Doppler imaging and nonimaging US techniques.

    Science.gov (United States)

    Neish, Ariane S; Blews, David E; Simms, Catherine A; Merritt, Robert K; Spinks, Alice J

    2002-03-01

    To determine whether criteria for screening patients with sickle cell anemia for stroke established with a nonimaging transcranial Doppler ultrasonographic (US) technique are applicable to studies performed with a transcranial Doppler US imaging technique. One hundred sixty-eight examinations in 66 children were performed for sickle cell stroke screening. Children were examined with nonimaging and imaging transcranial Doppler US techniques on the same day, for a total of 84 paired examinations. The time-averaged maximum mean velocity (V(mean)) and resistive index (RI) were calculated in the middle cerebral arteries, bifurcations of the distal internal carotid arteries, distal internal carotid arteries, anterior cerebral arteries, posterior cerebral arteries, and basilar arteries. The maximum systolic velocity (V(max)) was evaluated in the distal internal carotid arteries and middle cerebral arteries. V(mean), V(max), and RI measurements were subjected to repeated-measures multivariate analysis of covariance, and the Pearson product moment correlation was used for middle cerebral artery velocity, age, and hemoglobin. V(mean) measurements obtained with nonimaging and imaging techniques varied substantially for the bifurcation of the distal internal carotid artery, the posterior cerebral artery, and the basilar artery. Substantial differences were found in RIs for every vessel. Examination time was shorter with the nonimaging technique. V(mean) measurements in the middle cerebral artery, distal internal carotid artery, and anterior cerebral artery did not vary substantially between nonimaging and imaging transcranial Doppler US. RI data did not yield comparable measurements.

  3. Cost-effectiveness of laser Doppler imaging in burn care in the Netherlands

    NARCIS (Netherlands)

    Hop, M.J.; Hiddingh, J.; Stekelenburg, C.; Kuipers, H.C.; Middelkoop, E.; Nieuwenhuis, M.K.; Polinder, S.; van Baar, M.E.

    2013-01-01

    Background: Early accurate assessment of burn depth is important to determine the optimal treatment of burns. The method most used to determine burn depth is clinical assessment, which is the least expensive, but not the most accurate.Laser Doppler imaging (LDI) is a technique with which a more

  4. Cost-effectiveness of laser Doppler imaging in burn care in the Netherlands

    NARCIS (Netherlands)

    M.J. Hop (M. Jenda); J. Hiddingh (J.); C.M. Stekelenburg (C.); H.C. Kuipers (Hester); E. Middelkoop (Esther); M. Nieuwenhuis (Marianne); S. Polinder (Suzanne); M.E. van Baar (Margriet)

    2013-01-01

    textabstractBackground: Early accurate assessment of burn depth is important to determine the optimal treatment of burns. The method most used to determine burn depth is clinical assessment, which is the least expensive, but not the most accurate.Laser Doppler imaging (LDI) is a technique with which

  5. Systolic and Diastolic Function by Tissue Doppler Imaging Predicts Mortality in Patients with Atrial Fibrillation

    DEFF Research Database (Denmark)

    Dons, Maria; BieringSørensen, Tor; Jensen, Jan Skov

    2015-01-01

    AIM: Tissue Doppler Imaging (TDI) detects early signs of left ventricular dysfunction. The prognostic potential of TDI in patients with atrial fibrillation (AF) has, however, not yet been clarified. This study evaluates the prognostic value of TDI in patients with atrial fibrillation. METHODS...

  6. Total average diastolic longitudinal displacement by colour tissue doppler imaging as an assessment of diastolic function

    DEFF Research Database (Denmark)

    de Knegt, Martina Chantal; Biering-Sørensen, Tor; Søgaard, Peter

    2016-01-01

    BACKGROUND: The current method for a non-invasive assessment of diastolic dysfunction is complex with the use of algorithms of many different echocardiographic parameters. Total average diastolic longitudinal displacement (LD), determined by colour tissue Doppler imaging (TDI) via the measurement...

  7. Lembit Michelsoni CV / Lembit Michelson

    Index Scriptorium Estoniae

    Michelson, Lembit, 1960-

    2011-01-01

    Fotograaf Lembit Michelson meenutab lapsepõlve- ja kooliaastaid, sõjaväeteenistust, tööd fotograafina nõukogude ajal. Viimased 15 aastat töötab oma foto- ja disainistuudios Akriibia. Erinevatest fotoseeriatest. Artiklile lisatud 7 Lembit Michelsoni kirjutatud luuletust

  8. Laser Doppler Blood Flow Imaging Using a CMOS Imaging Sensor with On-Chip Signal Processing

    Directory of Open Access Journals (Sweden)

    Cally Gill

    2013-09-01

    Full Text Available The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue.

  9. Laser doppler blood flow imaging using a CMOS imaging sensor with on-chip signal processing.

    Science.gov (United States)

    He, Diwei; Nguyen, Hoang C; Hayes-Gill, Barrie R; Zhu, Yiqun; Crowe, John A; Gill, Cally; Clough, Geraldine F; Morgan, Stephen P

    2013-09-18

    The first fully integrated 2D CMOS imaging sensor with on-chip signal processing for applications in laser Doppler blood flow (LDBF) imaging has been designed and tested. To obtain a space efficient design over 64 × 64 pixels means that standard processing electronics used off-chip cannot be implemented. Therefore the analog signal processing at each pixel is a tailored design for LDBF signals with balanced optimization for signal-to-noise ratio and silicon area. This custom made sensor offers key advantages over conventional sensors, viz. the analog signal processing at the pixel level carries out signal normalization; the AC amplification in combination with an anti-aliasing filter allows analog-to-digital conversion with a low number of bits; low resource implementation of the digital processor enables on-chip processing and the data bottleneck that exists between the detector and processing electronics has been overcome. The sensor demonstrates good agreement with simulation at each design stage. The measured optical performance of the sensor is demonstrated using modulated light signals and in vivo blood flow experiments. Images showing blood flow changes with arterial occlusion and an inflammatory response to a histamine skin-prick demonstrate that the sensor array is capable of detecting blood flow signals from tissue.

  10. Real time 3D structural and Doppler OCT imaging on graphics processing units

    Science.gov (United States)

    Sylwestrzak, Marcin; Szlag, Daniel; Szkulmowski, Maciej; Gorczyńska, Iwona; Bukowska, Danuta; Wojtkowski, Maciej; Targowski, Piotr

    2013-03-01

    In this report the application of graphics processing unit (GPU) programming for real-time 3D Fourier domain Optical Coherence Tomography (FdOCT) imaging with implementation of Doppler algorithms for visualization of the flows in capillary vessels is presented. Generally, the time of the data processing of the FdOCT data on the main processor of the computer (CPU) constitute a main limitation for real-time imaging. Employing additional algorithms, such as Doppler OCT analysis, makes this processing even more time consuming. Lately developed GPUs, which offers a very high computational power, give a solution to this problem. Taking advantages of them for massively parallel data processing, allow for real-time imaging in FdOCT. The presented software for structural and Doppler OCT allow for the whole processing with visualization of 2D data consisting of 2000 A-scans generated from 2048 pixels spectra with frame rate about 120 fps. The 3D imaging in the same mode of the volume data build of 220 × 100 A-scans is performed at a rate of about 8 frames per second. In this paper a software architecture, organization of the threads and optimization applied is shown. For illustration the screen shots recorded during real time imaging of the phantom (homogeneous water solution of Intralipid in glass capillary) and the human eye in-vivo is presented.

  11. Diagnostic agreement between panoramic radiographs and color doppler images of carotid atheroma

    Directory of Open Access Journals (Sweden)

    Claudia Maria Romano-Sousa

    2009-02-01

    Full Text Available The aim of this study was to investigate the agreement between diagnoses of calcified atheroma seen on panoramic radiographs and color Doppler images. Our interest stems from the fact that panoramic images can show the presence of atheroma regardless of the level of obstruction detected by color Doppler images. Panoramic and color Doppler images of 16 patients obtained from the archives of the Health Department of the city of Valença, RJ, Brazil, were analyzed in this study. Both sides of each patient were observed on the images, with a total of 32 analyzed cervical regions. The level of agreement between diagnoses was analyzed using the Kappa statistics. There was a high level of agreement, with a Kappa value of 0.78. In conclusion, panoramic radiographs can help detecting calcifications in the cervical region of patients susceptible to vascular diseases predisposing to myocardial infarction and cerebrovascular accidents. If properly trained and informed, dentists can refer their patients to a physician for a cardiovascular evaluation in order to receive proper and timely medical treatment.

  12. Doppler coherence imaging of ion dynamics in VINETA.II and ASDEX-upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Gradic, Dorothea; Ford, Oliver; Wolf, Robert [Max-Planck-Institut fuer Plasmaphysik, Greifswald (Germany); Lunt, Tilmann [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    2016-07-01

    In magnetically confining plasma experiments, diagnosis of ion flows is of great importance to measure the plasma response to the magnetic field or the exhaust particle flows in the divertor areas. Doppler coherence imaging spectroscopy (CIS) is a relatively new technique for the observation of plasma bulk ion dynamics. It is a passive optical diagnostic enabling line-integrated measurements to obtain 2D images of the ion flow and ion temperature. The general principle is similar to traditional Doppler spectroscopy, however CIS uses an imaging interferometer to perform narrow-bandwidth Fourier spectroscopy. A major advantage of the coherence imaging technique is the large amount of spatial information recovered. This allows tomographic inversion of the line-integrated measurements. With existing CIS setups, scrape-off-layer and high field side edge impurity flows could be observed in the MAST, core and edge poloidal He II flows in the WEGA stellarator and divertor impurity flows in DIII-D. The main objective of this study is the research of ion dynamics in the small linear plasma experiment VINETA.II and ASDEX-Upgrade. First Doppler CIS measurements from Ar-II plasma discharges in VINETA.II and He-II, C-III divertor flows in ASDEX-Upgrade and their preliminary interpretation will be presented.

  13. Musculoskeletal colour/power Doppler in sports medicine: image parameters, artefacts, image interpretation and therapy

    DEFF Research Database (Denmark)

    Boesen, M I; Boesen, Mikael; Kønig, Merete Juhl

    2010-01-01

    This review article discusses the aspects of sports medicine where musculoskeletal Doppler ultrasound has valuable contribution in diagnosis and/or treatment of some of the typical musculoskeletal sports injuries. Also, conditions where the Doppler ultrasound has no value are discussed. Some...

  14. Musculoskeletal colour/power Doppler in sports medicine: image parameters, artefacts, image interpretation and therapy

    DEFF Research Database (Denmark)

    Boesen, M I; Boesen, Mikael; Kønig, Merete Juhl

    2011-01-01

    This review article discusses the aspects of sports medicine where musculoskeletal Doppler ultrasound has valuable contribution in diagnosis and/or treatment of some of the typical musculoskeletal sports injuries. Also, conditions where the Doppler ultrasound has no value are discussed. Some...

  15. New Approaches For Asteroid Spin State and Shape Modeling From Delay-Doppler Radar Images

    Science.gov (United States)

    Raissi, Chedy; Lamee, Mehdi; Mosiane, Olorato; Vassallo, Corinne; Busch, Michael W.; Greenberg, Adam; Benner, Lance A. M.; Naidu, Shantanu P.; Duong, Nicholas

    2016-10-01

    Delay-Doppler radar imaging is a powerful technique to characterize the trajectories, shapes, and spin states of near-Earth asteroids; and has yielded detailed models of dozens of objects. Reconstructing objects' shapes and spins from delay-Doppler data is a computationally intensive inversion problem. Since the 1990s, delay-Doppler data has been analyzed using the SHAPE software. SHAPE performs sequential single-parameter fitting, and requires considerable computer runtime and human intervention (Hudson 1993, Magri et al. 2007). Recently, multiple-parameter fitting algorithms have been shown to more efficiently invert delay-Doppler datasets (Greenberg & Margot 2015) - decreasing runtime while improving accuracy. However, extensive human oversight of the shape modeling process is still required. We have explored two new techniques to better automate delay-Doppler shape modeling: Bayesian optimization and a machine-learning neural network.One of the most time-intensive steps of the shape modeling process is to perform a grid search to constrain the target's spin state. We have implemented a Bayesian optimization routine that uses SHAPE to autonomously search the space of spin-state parameters. To test the efficacy of this technique, we compared it to results with human-guided SHAPE for asteroids 1992 UY4, 2000 RS11, and 2008 EV5. Bayesian optimization yielded similar spin state constraints within a factor of 3 less computer runtime.The shape modeling process could be further accelerated using a deep neural network to replace iterative fitting. We have implemented a neural network with a variational autoencoder (VAE), using a subset of known asteroid shapes and a large set of synthetic radar images as inputs to train the network. Conditioning the VAE in this manner allows the user to give the network a set of radar images and get a 3D shape model as an output. Additional development will be required to train a network to reliably render shapes from delay-Doppler

  16. Cardiac Time Intervals Measured by Tissue Doppler Imaging M-mode

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Møgelvang, Rasmus; Schnohr, Peter

    2016-01-01

    function was evaluated in 1915 participants by using both conventional echocardiography and tissue Doppler imaging (TDI). The cardiac time intervals, including the isovolumic relaxation time (IVRT), isovolumic contraction time (IVCT), and ejection time (ET), were obtained by TDI M-mode through the mitral......). Additionally, they displayed a significant dose-response relationship, between increasing severity of elevated blood pressure and increasing left ventricular mass index (P

  17. Importance of Doppler broadening in Compton scatter imaging techniques

    Science.gov (United States)

    Rao, Donepudi V.; Takeda, Tohoru; Itai, Yuji; Seltzer, S. M.; Hubbell, John H.; Zeniya, Tsutomu; Akatsuka, Takao; Cesareo, Roberto; Brunetti, Antonio; Gigante, Giovanni E.

    2001-12-01

    Compton scattering is a potential tool for the determination of bone mineral content or tissue density for dose planning purposes, and requires knowledge of the energy distribution of the X-rays through biological materials of medical interest in the X-ray and (gamma) -ray region. The energy distribution is utilized in a number of ways in diagnostic radiology, for example, in determining primary photon spectra, electron densities in separate volumes, and in tomography and imaging. The choice of the X-ray energy is more related to X-ray absorption, where as that of the scattering angle is more related to geometry. The evaluation of all the contributions are mandatory in Compton profile measurements and is important in X-ray imaging systems in order to achieve good results. In view of this, Compton profile cross-sections for few biological materials are estimated at nineteen K(alpha) X-ray energies and 60 keV (Am-241) photons. Energy broadening, geometrical broadening from 1 to 180 degree(s), FWHM of J(Pz) and FWHM of Compton energy broadening has been evaluated at various incident photon energies. These values are estimated around the centroid of the Compton profile with an energy interval of 0.1 keV and 1.0 keV for 60 keV photons. The interaction cross sections for the above materials are estimated using fractions-by-weight of the constituent elements. Input data for these tables are purely theoretical.

  18. MR imaging of multiple fibroadenoma in breast: comparison with color doppler images and histologic findings

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Soo Young; Yang, Ik; Park, Hai Jung; Lee, Yul; Chung, Bong Wha; Ahn, Hye Kyung [Hallym Univ. College of Medicine, Seoul (Korea, Republic of)

    1997-10-01

    To understand the different signal intensities seen on contrast enhanced magnetic resonance imaging (MRI) in multiple fibroadenoma of the breast, and to compare these with color Doppler ultrasonographic (CDUS) and histologic findings. MRI (1.0 Tesla, TIWI, T2WI, 3D-gradient echo dynamic contrast enhancement study) findings of 24 histologically proven cases of fibroadenoma in five patients were evaluated and compared with the histologic components (myxoid, adenomatous, fibrous). In addition, vascular flow, as seen on CDUS and histologic section, was compared. The observed degree of signal intensity waw classified into three groups, as follows: negative, 8.3%, mild to moderate, 54.2%; marked, 37.5%. On histologic section, the greater the fibrotic component, the higher the intensity of MRI enhancement, the greater the glandular component, and the intensity. CDUS showed vascular flow in only one tumor larger than 3cm in diameter. Vascular patterns of tumors on CDUS were dots in mass and detouring pattern, but in this case and in strongly enhanced cases, tumor vascularity-as seen on histologic section-showed no significant increase. Different signal intensities seen on contrast enhanced MRI in multiple fibroadenoma of the breast may be related more to the amount of glandular and fibrotic component than to increased tumor vascularity.

  19. MR imaging of multiple fibroadenoma in breast: comparison with color doppler images and histologic findings

    International Nuclear Information System (INIS)

    Chung, Soo Young; Yang, Ik; Park, Hai Jung; Lee, Yul; Chung, Bong Wha; Ahn, Hye Kyung

    1997-01-01

    To understand the different signal intensities seen on contrast enhanced magnetic resonance imaging (MRI) in multiple fibroadenoma of the breast, and to compare these with color Doppler ultrasonographic (CDUS) and histologic findings. MRI (1.0 Tesla, TIWI, T2WI, 3D-gradient echo dynamic contrast enhancement study) findings of 24 histologically proven cases of fibroadenoma in five patients were evaluated and compared with the histologic components (myxoid, adenomatous, fibrous). In addition, vascular flow, as seen on CDUS and histologic section, was compared. The observed degree of signal intensity waw classified into three groups, as follows: negative, 8.3%, mild to moderate, 54.2%; marked, 37.5%. On histologic section, the greater the fibrotic component, the higher the intensity of MRI enhancement, the greater the glandular component, and the intensity. CDUS showed vascular flow in only one tumor larger than 3cm in diameter. Vascular patterns of tumors on CDUS were dots in mass and detouring pattern, but in this case and in strongly enhanced cases, tumor vascularity-as seen on histologic section-showed no significant increase. Different signal intensities seen on contrast enhanced MRI in multiple fibroadenoma of the breast may be related more to the amount of glandular and fibrotic component than to increased tumor vascularity

  20. Standardised imaging technique for guided M-mode and Doppler echocardiography in the horse.

    Science.gov (United States)

    Long, K J; Bonagura, J D; Darke, P G

    1992-05-01

    Eighteen echocardiographic images useful for diagnostic imaging, M-mode echocardiography, and Doppler echocardiography of the equine heart were standardised by relating the position of the axial beam to various intracardiac landmarks. The transducer orientation required for each image was recorded in 14 adult horses by describing the degree of sector rotation and the orientation of the axial beam relative to the thorax. Repeatable images could be obtained within narrow limits of angulation and rotation for 14 of the 18 standardised images evaluated. Twenty-seven National Hunt horses were subsequently examined using this standardised technique. Selected cardiac dimensions were measured from two-dimensional and guided M-mode studies. Satisfactory results were achieved in 26 of the 27 horses. There was no linear correlation between any of the measured cardiac values and bodyweight. There was no significant difference between measurements taken from the left and the right hemithorax. Six horses were imaged on three consecutive days to assess the repeatability of the measurements. No significant difference was found between measurements obtained on different days. This study demonstrates a method for standardised echocardiographic evaluation of the equine heart that is repeatable, valuable for teaching techniques of equine echocardiography, applicable for diagnostic imaging and quantification of cardiac size, and useful for the evaluation of blood-flow patterns by Doppler ultrasound.

  1. Three-dimensional power Doppler sonography: imaging and quantifying blood flow and vascularization.

    Science.gov (United States)

    Pairleitner, H; Steiner, H; Hasenoehrl, G; Staudach, A

    1999-08-01

    To assess the feasibility of imaging low-velocity blood flow in adnexal masses by transvaginal three-dimensional power Doppler sonography, to analyze three-dimensional power Doppler sonography data sets with a new computer-assisted method and to test the reproducibility of the technique. A commercially available 5-MHz Combison 530 ultrasound system was used to perform three-dimensional power Doppler sonography transvaginally. A cube (= volume of interest) was defined enclosing the vessels of the cyst and the Cartesian characteristics were stored on a hard disk. This cube was analyzed using specially designed software. Five indices representing vascularization (the vascularization index (VI) or blood flow (the flow index (FI)) or both (the vascularization-flow index (VFI)) were calculated. The intraobserver repeatability of cube definition and scan repetition was assessed using Hartley's test for homogeneous variances. Interobserver agreement was assessed by the Pearson correlation coefficient. Imaging of vessels with low-velocity blood flow by three-dimensional power Doppler sonography and cube definition was possible in all adnexal massed studied. In some cases even induced non-vascular flow related to endometriosis was detected. The calculated F value with intraobserver repeated Cartesian file-saving ranged from 0 to 18.8, with intraobserver scan repetition from 4.74 to 24.8 for VI, FI 1, FI 2 and VFI 1; for VFI 2 the calculated F value was 64. The interobserver correlation coefficient ranged between 0.83 and 0.92 for VI, FI 1, FI 2 and VFI 1; for VFI 2 the correlation coefficient was less than 0.75. Vessels with low-velocity blood flow can be imaged using three-dimensional power Doppler sonography. Induced non-vascular flow was detected in endometriotic cyst fluid. Three-dimensional power Doppler sonography combined with the cube method gave reproducible information for all indices except VFI 2. These indices might prove to be a new predictor in all fields of

  2. The Efficacy of Magnetic Resonance Imaging and Color Doppler Ultrasonography in Diagnosis of Salivary Gland Tumors

    Directory of Open Access Journals (Sweden)

    Behrooz Davachi

    2014-12-01

    Full Text Available Background and aims. Although salivary gland tumors are not very common, early diagnosis and treatment is crucial because of their proximity to vital organs, and therefore, determining the efficacy of new imaging procedures becomes important. This study aimed to evaluate the efficacy of magnetic resonance imaging (MRI and color doppler ultrasonography parameters in the diagnosis and differentiation of benign and malignant salivary gland tumors. Materials and methods. In this cross-sectional study, color doppler ultrasonography and MRI were performed for 22 patients with salivary gland tumor. Demographic data as well as MRI, color doppler ultrasonography, and surgical parameters including tumor site, signal in MRI images, ultrasound echo, tumor border, lymphadenopathy, invasion, perfusion, vascular resistance index (RI, vascular pulse index (PI were analyzed using Chi-square test, Fisher’s exact test, and independent ttest. Results. The mean age of patients was 46.59±13.97 years (8 males and 14 females. Patients with malignant tumors were older (P < 0.01. The most common tumors were pleomorphic adenoma (36.4%, metastasis (36.4%, and mucoepidermoid carcinoma (9%. Nine tumors (40.9% were benign and 13 (59.1% were malignant. The overall accuracy of MRI and color doppler ultrasonography in determining tumor site was 100% and 95%, respectively. No significant difference observed between RI and PI and the diagnosis of tumor. Conclusion. Both MRI and ultrasonography have high accuracy in the localization of tumors. Well-identified border was a sign of benign tumors. Also, invasion to adjacent structures was a predictive factor for malignancy.

  3. High PRF ultrafast sliding compound doppler imaging: fully qualitative and quantitative analysis of blood flow.

    Science.gov (United States)

    Kang, Jinbum; Jang, Won Seuk; Yoo, Yangmo

    2018-02-09

    Ultrafast compound Doppler imaging based on plane-wave excitation (UCDI) can be used to evaluate cardiovascular diseases using high frame rates. In particular, it provides a fully quantifiable flow analysis over a large region of interest with high spatio-temporal resolution. However, the pulse-repetition frequency (PRF) in the UCDI method is limited for high-velocity flow imaging since it has a tradeoff between the number of plane-wave angles (N) and acquisition time. In this paper, we present high PRF ultrafast sliding compound Doppler imaging method (HUSDI) to improve quantitative flow analysis. With the HUSDI method, full scanline images (i.e. each tilted plane wave data) in a Doppler frame buffer are consecutively summed using a sliding window to create high-quality ensemble data so that there is no reduction in frame rate and flow sensitivity. In addition, by updating a new compounding set with a certain time difference (i.e. sliding window step size or L), the HUSDI method allows various Doppler PRFs with the same acquisition data to enable a fully qualitative, retrospective flow assessment. To evaluate the performance of the proposed HUSDI method, simulation, in vitro and in vivo studies were conducted under diverse flow circumstances. In the simulation and in vitro studies, the HUSDI method showed improved hemodynamic representations without reducing either temporal resolution or sensitivity compared to the UCDI method. For the quantitative analysis, the root mean squared velocity error (RMSVE) was measured using 9 angles (-12° to 12°) with L of 1-9, and the results were found to be comparable to those of the UCDI method (L  =  N  =  9), i.e.  ⩽0.24 cm s -1 , for all L values. For the in vivo study, the flow data acquired from a full cardiac cycle of the femoral vessels of a healthy volunteer were analyzed using a PW spectrogram, and arterial and venous flows were successfully assessed with high Doppler PRF (e.g. 5 kHz at L

  4. High PRF ultrafast sliding compound doppler imaging: fully qualitative and quantitative analysis of blood flow

    Science.gov (United States)

    Kang, Jinbum; Jang, Won Seuk; Yoo, Yangmo

    2018-02-01

    Ultrafast compound Doppler imaging based on plane-wave excitation (UCDI) can be used to evaluate cardiovascular diseases using high frame rates. In particular, it provides a fully quantifiable flow analysis over a large region of interest with high spatio-temporal resolution. However, the pulse-repetition frequency (PRF) in the UCDI method is limited for high-velocity flow imaging since it has a tradeoff between the number of plane-wave angles (N) and acquisition time. In this paper, we present high PRF ultrafast sliding compound Doppler imaging method (HUSDI) to improve quantitative flow analysis. With the HUSDI method, full scanline images (i.e. each tilted plane wave data) in a Doppler frame buffer are consecutively summed using a sliding window to create high-quality ensemble data so that there is no reduction in frame rate and flow sensitivity. In addition, by updating a new compounding set with a certain time difference (i.e. sliding window step size or L), the HUSDI method allows various Doppler PRFs with the same acquisition data to enable a fully qualitative, retrospective flow assessment. To evaluate the performance of the proposed HUSDI method, simulation, in vitro and in vivo studies were conducted under diverse flow circumstances. In the simulation and in vitro studies, the HUSDI method showed improved hemodynamic representations without reducing either temporal resolution or sensitivity compared to the UCDI method. For the quantitative analysis, the root mean squared velocity error (RMSVE) was measured using 9 angles (-12° to 12°) with L of 1-9, and the results were found to be comparable to those of the UCDI method (L  =  N  =  9), i.e.  ⩽0.24 cm s-1, for all L values. For the in vivo study, the flow data acquired from a full cardiac cycle of the femoral vessels of a healthy volunteer were analyzed using a PW spectrogram, and arterial and venous flows were successfully assessed with high Doppler PRF (e.g. 5 kHz at L

  5. Measurement of portal blood flow in healthy individuals: a comparison between magnetic resonance imaging and Doppler ultrasound

    International Nuclear Information System (INIS)

    Costa, Juliana Dantas da; Sebastiane, Patricia Moreno; Leao, Alberto Ribeiro de Souza; Santos, Jose Eduardo Mourao; Moulin, Danilo Sales; D'Ippolito, Giuseppe

    2008-01-01

    Objective: To evaluate the inter-observer agreement between Doppler ultrasonography and magnetic resonance imaging in the quantification of portal blood flow in healthy individuals, as well as evaluating the reproducibility of both methods. Materials and methods: A prospective, transverse, observational and self-paired study was developed evaluating 20 healthy volunteers whose portal blood flow was measured by means of Doppler ultrasonography and magnetic resonance imaging performed by two independent observers. Interobserver and inter method agreements were calculated using the intra class and Pearson's correlation coefficients. Results: The agreement between Doppler ultrasonography and magnetic resonance imaging was low (intra class coefficient: 1.9%-18.2%; Pearson's coefficient: 0.1%-13.7%; p=0.565). Mean values for the portal blood flow measured by Doppler ultrasonography and magnetic resonance imaging were respectively 0.768 l/min and 0.742 l/min. Interobserver agreement for quantification of the portal blood flow by Doppler ultrasonography and magnetic resonance imaging was respectively reasonable (intra class coefficient: 43.3%; Pearson's coefficient: 43.0%) and excellent (intra class coefficient: 91.4%; Pearson's coefficient: 93.4%). Conclusion: In the present study, magnetic resonance imaging demonstrated to be a reliable method for quantifying the portal blood flow, with a higher interobserver agreement than Doppler ultrasonography. The inter method agreement was low. (author)

  6. Characterization of benign and malignant solid breast masses in harmonic 3D power Doppler imaging

    International Nuclear Information System (INIS)

    Hsiao, Y.-H.; Huang, Y.-L.; Kuo, S.-J.; Liang, W.-M.; Chen, S.-T.; Chen, D.-R.

    2009-01-01

    Purpose: The authors assessed the characteristics of benign and malignant solid breast tumors in harmonic three-dimensional (3D) power Doppler imaging and proposed decision models to classify benign and malignant breast tumors. Materials and methods: A total of 86 malignant and 97 benign harmonic 3D power Doppler US images were analyzed. All the harmonic 3D power Doppler images were obtained using a Voluson730 US system (GE, Zipf, Austria) equipped with a RSP 6-12 transducer and tissue harmonic imaging modalities. Imaging analysis was performed using the Virtual Organ Computer-aided Analysis (VOCAL)-imaging program. Histogram indices, the vascularization index (VI), flow index (FI) and vascularization-flow index (VFI), were calculated for the intra-tumor and for shells with an outside thickness of 3 mm surrounding the breast tumors. The receiver operating characteristic (ROC) curves were calculated to estimate the diagnostic performances. Results: The results revealed that the choice of decision model comprised the parameters of patient age, intra-tumor VI, and tumor volume to classify benign and malignant breast tumors. The area under the ROC curve (Az) was 0.910, accuracy was 81.4%, and sensitivity and specificity were 81.4% and 81.4%, respectively. The parameter intra-tumor VI was the choice for all of the histogram indices in differentiating between malignant and benign lesions. Conclusion: The decision model, which was composed of patient age, tumor volume and intra-tumor VI, and a cut-off value for intra-tumor VI at the upper end of patient age and tumor volume, was recommended in clinical application.

  7. SCANDI – an all-sky Doppler imager for studies of thermospheric spatial structure

    Directory of Open Access Journals (Sweden)

    A. L. Aruliah

    2010-02-01

    Full Text Available A new all-sky Fabry-Perot Interferometer called the Scanning Doppler Imager (SCANDI was built and installed at Longyearbyen in December 2006. Observations have been made of the Doppler shifts and Doppler broadening of the 630 nm airglow and aurora, from which upper thermospheric winds and temperatures are calculated. SCANDI allows measurements over a field-of-view (FOV with a horizontal radius of nearly 600 km for observations at an altitude of 250 km using a time resolution of 8 min. The instrument provides the ability to observe thermospheric spatial structure within a FOV which overlaps that of the EISCAT Svalbard radar and CUTLASS SuperDARN radars. Coordinating with these instruments provides an important opportunity for studying ion-neutral coupling. The all-sky image is divided into several sectors to provide a horizontal spatial resolution of between 100–300 km. This is a powerful extension in observational capability but requires careful calibration and data analysis, as described here. Two observation modes were used: a fixed and a scanning etalon gap. SCANDI results are corroborated using the Longyearbyen single look direction FPI, and ESR measurements of the ion temperatures. The data show thermospheric temperature gradients of a few Kelvins per kilometre, and a great deal of meso-scale variability on spatial scales of several tens of kilometres.

  8. In-vivo imaging of blood flow dynamics using color Doppler optical coherence tomography

    Science.gov (United States)

    Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

    2000-04-01

    Noninvasive quantitation of blood flow in the retinal micro circulation may elucidate the progression and treatment of ocular disorders including diabetic retinopathy, age-related degeneration, and glaucoma. Color Doppler optical coherence tomography was recently introduced as a technique allowing simultaneous micron-scale resolution cross-sectional imaging of tissue micro structure and blood flow in the human retina. Here, time-resolved imaging of dynamics of blood flow profiles was performed to measure cardiac pulsatility within retinal vessels. Retinal pulsatility has been shown to decrease throughout the progression of diabetic retinopathy.

  9. Power Doppler ultrasonography and synovitis: correlating ultrasound imaging with histopathological findings and evaluating the performance of ultrasound equipments.

    Science.gov (United States)

    Koski, J M; Saarakkala, S; Helle, M; Hakulinen, U; Heikkinen, J O; Hermunen, H

    2006-12-01

    To examine the validity of power Doppler ultrasound imaging to identify synovitis, using histopathology as gold standard, and to assess the performance of ultrasound equipments. 44 synovial sites in small and large joints, bursae and tendon sheaths were depicted with ultrasound. A synovial biopsy was performed on the site depicted and a synovial sample was taken for histopathological evaluation. The performance of three ultrasound devices was tested using flow phantoms. A positive Doppler signal was detected in 29 of 35 (83%) of the patients with active histological inflammation. In eight additional samples, histological examination showed other pathological synovial findings and a Doppler signal was detected in five of them. No significant correlation was found between the amount of Doppler signal and histological synovitis score (r = 0.239, p = NS). The amount of subsynovial infiltration of polymorphonuclear leucocytes and surface fibrin correlated significantly with the amount of power Doppler signal: r = 0.397 (pultrasound devices differed in showing the smallest detectable flow. A negative Doppler signal does not exclude the possibility of synovitis. A positive Doppler signal in the synovium is an indicator of an active synovial inflammation in patients. A Doppler signal does not correlate with the extent of the inflammation and it can also be seen in other synovial reactions. It is important that the quality measurements of ultrasound devices are reported, because the results should be evaluated against the quality of the device used.

  10. In-fiber integrated Michelson interferometer.

    Science.gov (United States)

    Yuan, Libo; Yang, Jun; Liu, Zhihai; Sun, Jiaxing

    2006-09-15

    A novel fiber-optic in-fiber integrated Michelson interferometer has been proposed and demonstrated. It consists of a segment of two-core fiber with a mirrored fiber end. The sensing characteristics based on the two-core fiber bending, corresponding to the shift of the phase of the two-core in-fiber integrated Michelson interferometer, are investigated.

  11. Bone surface enhancement in ultrasound images using a new Doppler-based acquisition/processing method

    Science.gov (United States)

    Yang, Xu; Tang, Songyuan; Tasciotti, Ennio; Righetti, Raffaella

    2018-01-01

    Ultrasound (US) imaging has long been considered as a potential aid in orthopedic surgeries. US technologies are safe, portable and do not use radiations. This would make them a desirable tool for real-time assessment of fractures and to monitor fracture healing. However, image quality of US imaging methods in bone applications is limited by speckle, attenuation, shadow, multiple reflections and other imaging artifacts. While bone surfaces typically appear in US images as somewhat ‘brighter’ than soft tissue, they are often not easily distinguishable from the surrounding tissue. Therefore, US imaging methods aimed at segmenting bone surfaces need enhancement in image contrast prior to segmentation to improve the quality of the detected bone surface. In this paper, we present a novel acquisition/processing technique for bone surface enhancement in US images. Inspired by elastography and Doppler imaging methods, this technique takes advantage of the difference between the mechanical and acoustic properties of bones and those of soft tissues to make the bone surface more easily distinguishable in US images. The objective of this technique is to facilitate US-based bone segmentation methods and improve the accuracy of their outcomes. The newly proposed technique is tested both in in vitro and in vivo experiments. The results of these preliminary experiments suggest that the use of the proposed technique has the potential to significantly enhance the detectability of bone surfaces in noisy ultrasound images.

  12. Bone surface enhancement in ultrasound images using a new Doppler-based acquisition/processing method.

    Science.gov (United States)

    Yang, Xu; Tang, Songyuan; Tasciotti, Ennio; Righetti, Raffaella

    2018-01-17

    Ultrasound (US) imaging has long been considered as a potential aid in orthopedic surgeries. US technologies are safe, portable and do not use radiations. This would make them a desirable tool for real-time assessment of fractures and to monitor fracture healing. However, image quality of US imaging methods in bone applications is limited by speckle, attenuation, shadow, multiple reflections and other imaging artifacts. While bone surfaces typically appear in US images as somewhat 'brighter' than soft tissue, they are often not easily distinguishable from the surrounding tissue. Therefore, US imaging methods aimed at segmenting bone surfaces need enhancement in image contrast prior to segmentation to improve the quality of the detected bone surface. In this paper, we present a novel acquisition/processing technique for bone surface enhancement in US images. Inspired by elastography and Doppler imaging methods, this technique takes advantage of the difference between the mechanical and acoustic properties of bones and those of soft tissues to make the bone surface more easily distinguishable in US images. The objective of this technique is to facilitate US-based bone segmentation methods and improve the accuracy of their outcomes. The newly proposed technique is tested both in in vitro and in vivo experiments. The results of these preliminary experiments suggest that the use of the proposed technique has the potential to significantly enhance the detectability of bone surfaces in noisy ultrasound images.

  13. Dynamics of contrast enhancement in MR imaging and power Doppler ultrasonography of solid breast lesions

    International Nuclear Information System (INIS)

    Reinikainen, H.; Paeaekkoe, E.; Suramo, I.; Paeivaensalo, M.; Rissanen, T.

    2002-01-01

    Purpose: To evaluate the dynamics of contrast enhancement in solid breast lesions at contrast-enhanced MR imaging and power Doppler ultrasonography (US) and to compare the methods to histology and to each other. Material and Methods: Forty breast lesions were prospectively examined with dynamic MR and power Doppler US. Time-signal intensity curves of enhancement were obtained for both methods. The shape of the curve was analyzed to be benign, indeterminate or malignant. The curves were also analyzed quantitatively by calculating the slope of the curve and the area under the curve (both methods), relative enhancement (MR), and time to peak (US). The lesions were divided into malignant lesions, fibroadenomas, and other benign lesions. The results were compared to histology. Results: In the subjective analysis of the MR curve in differentiating between benign and malignant lesions the accuracy was 90%. The MR curve also enabled differentiation between fibroadenomas and malignancies. The accuracy of the US curve was 38%. Quantitatively, statistically significant differences were found using all the MR variables, except between malignancies and fibroadenomas. Using the US variables, no significant difference was found between the groups. Conclusion: The dynamics of contrast-enhanced MR were reliable in the differential diagnosis of solid breast lesions, but contrast-enhanced power Doppler US was of limited value

  14. Exercise and Cardiac Function by Tissue Doppler Imaging. The Copenhagen City Heart Study

    DEFF Research Database (Denmark)

    Joseph, Gowsini; Sogaard, Peter; Nielsen, Gitte

    2016-01-01

    diastolic (e') and late diastolic (a') velocities were measured by color TDI. Longitudinal displacement (LD) was calculated from the velocity curve during ejection. Statistical tests were performed by linear univariate and multivariable regression analyses, in relation to age groups (lt;50years, 50-65 years......Introduction: TDI (Tissue Doppler Imaging) is a sensitive marker of myocardial dysfunction and mortality in heart disease and in the general population. Regular physical activity is associated with risk reduction in coronary heart disease and mortality. There is a need for studies to clarify...

  15. Exercise and Cardiac Function by Tissue Doppler Imaging. The Copenhagen City Heart Study

    DEFF Research Database (Denmark)

    Joseph, Gowsini; Sogaard, Peter; Nielsen, Gitte

    diastolic (e') and late diastolic (a') velocities were measured by color TDI. Longitudinal displacement (LD) was calculated from the velocity curve during ejection. Statistical tests were performed by linear univariate and multivariable regression analyses, in relation to age groups (lt;50years, 50-65 years......Introduction: TDI (Tissue Doppler Imaging) is a sensitive marker of myocardial dysfunction and mortality in heart disease and in the general population. Regular physical activity is associated with risk reduction in coronary heart disease and mortality. There is a need for studies to clarify...

  16. Laser Doppler imaging as a tool in the burn wound treatment protocol

    OpenAIRE

    Venclauskiene, Algirda; Basevicius, Algidas; Zacharevskij, Ernest; Vaicekauskas, Vytautas; Rimdeika, Rytis; Lukosevicius, Saulius

    2014-01-01

    Introduction The main treatment of burns is early excision of injured tissues. Aim To compare two different methods of examination of burned patients: clinical burn depth examination (CDE) and laser Doppler imaging (LDI). Material and methods A prospective randomized study of 57 burn patients treated in 2009–2011 was carried out. The burned patients were randomized into a CDE group and an LDI group. The CDE and LDI scan were performed 72 h after injury, with the second and third CDE and LDI s...

  17. Performance evaluation of an all-fiber image-reject homodyne coherent Doppler wind lidar

    DEFF Research Database (Denmark)

    Abari, Cyrus F.; Pedersen, Anders Tegtmeier; Dellwik, Ebba

    2015-01-01

    The main purpose of this study is to evaluate the near-zero wind velocity measurement performance of two separate 1.5 µm all-fiber coherent Doppler lidars (CDLs). The performance characterization is carried out through the presentation of the results from two separate atmospheric field campaigns....... In one campaign, a recently developed continuous wave (CW) CDL benefiting from an image-reject front-end was deployed. The other campaign utilized a different CW CDL, benefiting from a heterodyne receiver with intermediate-frequency (IF) sampling. In both field campaigns the results are compared against...

  18. Cardiac time intervals by tissue Doppler imaging M-mode echocardiography

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor

    2016-01-01

    for myocardial myocytes to achieve an LV pressure equal to that of aorta increases, resulting in a prolongation of the isovolumic contraction time (IVCT). Furthermore, the ability of myocardial myocytes to maintain the LV pressure decreases, resulting in reduction in the ejection time (ET). As LV diastolic...... of whether the LV is suffering from impaired systolic or diastolic function. A novel method of evaluating the cardiac time intervals has recently evolved. Using tissue Doppler imaging (TDI) M-mode through the mitral valve (MV) to estimate the cardiac time intervals may be an improved method reflecting global...

  19. Myocardial response to a triathlon in male athletes evaluated by Doppler tissue imaging and biochemical parameters

    DEFF Research Database (Denmark)

    Leetmaa, T H; Dam, A; Glintborg, D

    2008-01-01

    (cTnT) and pro-brain natriuretic peptide (pro-BNP)] and echocardiography. Conventional echocardiography techniques and new Doppler tissue imaging (DTI) modalities were applied before and immediately after the competition. Blood samples were drawn 1 week before, immediately after and 12-24 h post...... and systolic velocities decreased, thus suggesting reversible cardiac fatigue. When using cardiac markers and echocardiographic findings, a triathlon was found to have no significant negative effects on left ventricular function or myocardial tissue in male athletes....

  20. 2D Doppler backscattering using synthetic aperture microwave imaging of MAST edge plasmas

    Science.gov (United States)

    Thomas, D. A.; Brunner, K. J.; Freethy, S. J.; Huang, B. K.; Shevchenko, V. F.; Vann, R. G. L.

    2016-02-01

    Doppler backscattering (DBS) is already established as a powerful diagnostic; its extension to 2D enables imaging of turbulence characteristics from an extended region of the cut-off surface. The Synthetic Aperture Microwave Imaging (SAMI) diagnostic has conducted proof-of-principle 2D DBS experiments of MAST edge plasma. SAMI actively probes the plasma edge using a wide (±40° vertical and horizontal) and tuneable (10-34.5 GHz) beam. The Doppler backscattered signal is digitised in vector form using an array of eight Vivaldi PCB antennas. This allows the receiving array to be focused in any direction within the field of view simultaneously to an angular range of 6-24° FWHM at 10-34.5 GHz. This capability is unique to SAMI and is a novel way of conducting DBS experiments. In this paper the feasibility of conducting 2D DBS experiments is explored. Initial observations of phenomena previously measured by conventional DBS experiments are presented; such as momentum injection from neutral beams and an abrupt change in power and turbulence velocity coinciding with the onset of H-mode. In addition, being able to carry out 2D DBS imaging allows a measurement of magnetic pitch angle to be made; preliminary results are presented. Capabilities gained through steering a beam using a phased array and the limitations of this technique are discussed.

  1. Doppler Tomography

    Science.gov (United States)

    Marsh, T. R.

    I review the method of Doppler tomography which translates binary-star line profiles taken at a series of orbital phases into a distribution of emission over the binary. I begin with a discussion of the basic principles behind Doppler tomography, including a comparison of the relative merits of maximum entropy regularisation versus filtered back-projection for implementing the inversion. Following this I discuss the issue of noise in Doppler images and possible methods for coping with it. Then I move on to look at the results of Doppler Tomography applied to cataclysmic variable stars. Outstanding successes to date are the discovery of two-arm spiral shocks in cataclysmic variable accretion discs and the probing of the stream/magnetospheric interaction in magnetic cataclysmic variable stars. Doppler tomography has also told us much about the stream/disc interaction in non-magnetic systems and the irradiation of the secondary star in all systems. The latter indirectly reveals such effects as shadowing by the accretion disc or stream. I discuss all of these and finish with some musings on possible future directions for the method. At the end I include a tabulation of Doppler maps published in refereed journals.

  2. MEMS-based handheld fourier domain Doppler optical coherence tomography for intraoperative microvascular anastomosis imaging.

    Directory of Open Access Journals (Sweden)

    Yong Huang

    Full Text Available To demonstrate the feasibility of a miniature handheld optical coherence tomography (OCT imager for real time intraoperative vascular patency evaluation in the setting of super-microsurgical vessel anastomosis.A novel handheld imager Fourier domain Doppler optical coherence tomography based on a 1.3-µm central wavelength swept source for extravascular imaging was developed. The imager was minimized through the adoption of a 2.4-mm diameter microelectromechanical systems (MEMS scanning mirror, additionally a 12.7-mm diameter lens system was designed and combined with the MEMS mirror to achieve a small form factor that optimize functionality as a handheld extravascular OCT imager. To evaluate in-vivo applicability, super-microsurgical vessel anastomosis was performed in a mouse femoral vessel cut and repair model employing conventional interrupted suture technique as well as a novel non-suture cuff technique. Vascular anastomosis patency after clinically successful repair was evaluated using the novel handheld OCT imager.With an adjustable lateral image field of view up to 1.5 mm by 1.5 mm, high-resolution simultaneous structural and flow imaging of the blood vessels were successfully acquired for BALB/C mouse after orthotopic hind limb transplantation using a non-suture cuff technique and BALB/C mouse after femoral artery anastomosis using a suture technique. We experimentally quantify the axial and lateral resolution of the OCT to be 12.6 µm in air and 17.5 µm respectively. The OCT has a sensitivity of 84 dB and sensitivity roll-off of 5.7 dB/mm over an imaging range of 5 mm. Imaging with a frame rate of 36 Hz for an image size of 1000(lateral×512(axial pixels using a 50,000 A-lines per second swept source was achieved. Quantitative vessel lumen patency, lumen narrowing and thrombosis analysis were performed based on acquired structure and Doppler images.A miniature handheld OCT imager that can be used for intraoperative evaluation of

  3. The Doppler effect and the three most famous experiments for special relativity

    Directory of Open Access Journals (Sweden)

    Shukri Klinaku

    Full Text Available Using the general formula for the Doppler effect at any arbitrary angle, the three famous experiments for special theory of relativity will be examined. Explanation of the experiments of Michelson, Kennedy–Thorndike and Ives–Stilwell will be given in a precise and elegant way without postulates, arbitrary assumptions or approximations. Keywords: Doppler effect, Michelson experiment, Kennedy–Thorndike experiment, Ives–Stilwell experiment

  4. Quantitation of stress echocardiography by tissue Doppler and strain rate imaging: a dream come true?

    Science.gov (United States)

    Galderisi, Maurizio; Mele, Donato; Marino, Paolo Nicola

    2005-01-01

    Tissue Doppler (TD) is an ultrasound tool providing a quantitative agreement of left ventricular regional myocardial function in different modalities. Spectral pulsed wave (PW) TD, performed online during the examination, measures instantaneous myocardial velocities. By means of color TD, velocity images are digitally stored for subsequent off-line analysis and mean myocardial velocities are measured. An implementation of color TD includes strain rate imaging (SRI), based on post-processing conversion of regional velocities in local myocardial deformation rate (strain rate) and percent deformation (strain). These three modalities have been applied to stress echocardiography for quantitative evaluation of regional left ventricular function and detection of ischemia and viability. They present advantages and limitations. PWTD does not permit the simultaneous assessment of multiple walls and therefore is not compatible with clinical stress echocardiography while it could be used in a laboratory setting. Color TD provides a spatial map of velocity throughout the myocardium but its results are strongly affected by the frame rate. Both color TD and PWTD are also influenced by overall cardiac motion and tethering from adjacent segments and require reference velocity values for interpretation of regional left ventricular function. High frame rate (i.e. > 150 ms) post-processing-derived SRI can potentially overcome these limitations, since measurements of myocardial deformation have not any significant apex-to-base gradient. Preliminary studies have shown encouraging results about the ability of SRI to detect ischemia and viability, in terms of both strain rate changes and/or evidence of post-systolic thickening. SRI is, however, Doppler-dependent and time-consuming. Further technical refinements are needed to improve its application and introduce new ultrasound modalities to overcome the limitations of the Doppler-derived deformation analysis.

  5. Doppler imaging of hypoxic-ischemic encephalopathy in term neonates on the first day of life

    International Nuclear Information System (INIS)

    Wilczynska, M.; Stefanczyk, L.; Zieba, K.; Bieganski, T.; Gulczynska, E.

    2004-01-01

    Hypoxic-ischaemic encephalopathy (HIE) is the most important neurological cause of mortality and poor neurodevelopmental outcome in neonates and infants. The aim of the study was to perform routine transfontanellar US brain scanning together with doppler evaluation of blood flow in anterior cerebral artery in the group of neonates with perinatal asphyxia studied at the first day of their life. The study group consisted of asphyxiated neonates (n=11), birth weight 3576,0 ± 426,0 g, gestational age 39,4 ± 1,1 weeks, pH of cord arterial blood 6,89 ± 0,45, 1 st minute Apgar score 2 points. The control group were healthy neonates (n=20), , birth weight 3354,0 ± 378,0 g, gestational age 38,9 ± 1,8 weeks, pH of cord arterial blood 7,28 ± 0,41, 1 st minute Apgar score 8 points. As compared to healthy children asphyxiated neonates had significantly decreased RI value (right cerebral artery 0,53 ± 0,02 vs. 0,72 ± 0,02; left cerebral artery 0,55 ± 0,02 vs. 0,73 ± 0,02), despite not all of them had obvious HIE features in routine US examination. None of these neonates lived longer than 10 days. Doppler examination of cerebral blood flow in term neonates born with perinatal asphyxia could be valuable complementary method of US imaging, especially in those patients with very discreet or absent HIE features in routine US scan. Results of doppler imaging could serve as prognostic factor for clinical outcome. (author)

  6. Multiple spacecraft Michelson stellar interferometer

    Science.gov (United States)

    Stachnik, R. V.; Arnold, D.; Melroy, P.; Mccormack, E. F.; Gezari, D. Y.

    1984-01-01

    Results of an orbital analysis and performance assessment of SAMSI (Spacecraft Array for Michelson Spatial Interferometry) are presented. The device considered includes two one-meter telescopes in orbits which are identical except for slightly different inclinations; the telescopes achieve separations as large as 10 km and relay starlight to a central station which has a one-meter optical delay line in one interferometer arm. It is shown that a 1000-km altitude, zero mean inclination orbit affords natural scanning of the 10-km baseline with departures from optical pathlength equality which are well within the corrective capacity of the optical delay line. Electric propulsion is completely adequate to provide the required spacecraft motions, principally those needed for repointing. Resolution of 0.00001 arcsec and magnitude limits of 15 to 20 are achievable.

  7. Enlarging the angle of view in Michelson-interferometer-based shearography by embedding a 4f system.

    Science.gov (United States)

    Wu, Sijin; He, Xiaoyuan; Yang, Lianxiang

    2011-07-20

    Digital shearography based on Michelson interferometers suffers from the disadvantage of a small angle of view due to the structure. We demonstrate a novel digital shearography system with a large angle of view. In the optical arrangement, the imaging lens is in front of the Michelson interferometer rather than behind it as in traditional digital shearography. Thus, the angle of view is no longer limited by the Michelson interferometer. The images transmitting between the separate lens and camera are accomplished by a 4f system in the new style of shearography. The influences of the 4f system on shearography are also discussed. © 2011 Optical Society of America

  8. High-frequency dual mode pulsed wave Doppler imaging for monitoring the functional regeneration of adult zebrafish hearts

    Science.gov (United States)

    Kang, Bong Jin; Park, Jinhyoung; Kim, Jieun; Kim, Hyung Ham; Lee, Changyang; Hwang, Jae Youn; Lien, Ching-Ling; Shung, K. Kirk

    2015-01-01

    Adult zebrafish is a well-known small animal model for studying heart regeneration. Although the regeneration of scars made by resecting the ventricular apex has been visualized with histological methods, there is no adequate imaging tool for tracking the functional recovery of the damaged heart. For this reason, high-frequency Doppler echocardiography using dual mode pulsed wave Doppler, which provides both tissue Doppler (TD) and Doppler flow in a same cardiac cycle, is developed with a 30 MHz high-frequency array ultrasound imaging system. Phantom studies show that the Doppler flow mode of the dual mode is capable of measuring the flow velocity from 0.1 to 15 cm s−1 with high accuracy (p-value = 0.974 > 0.05). In the in vivo study of zebrafish, both TD and Doppler flow signals were simultaneously obtained from the zebrafish heart for the first time, and the synchronized valve motions with the blood flow signals were identified. In the longitudinal study on the zebrafish heart regeneration, the parameters for diagnosing the diastolic dysfunction, for example, E/Em < 10, E/A < 0.14 for wild-type zebrafish, were measured, and the type of diastolic dysfunction caused by the amputation was found to be similar to the restrictive filling. The diastolic function was fully recovered within four weeks post-amputation. PMID:25505135

  9. The Design and Implementation of the Wide-Angle Michelson Interferometer to Observe Thermospheric Winds.

    Science.gov (United States)

    Ward, William Edmund

    The design and implementation of a Wide-Angle Michelson interferometer (WAMI) as a high spectral resolution device for measuring Doppler shifts and temperatures in the thermosphere is discussed in detail. A general theoretical framework is developed to describe the behavior of interferometers and is applied to the WAMI. Notions concerning the optical coupling of various surfaces within an interferometer are developed and used to investigate the effects of misalignments in the WAMI optics. In addition, these notions in combination with ideas on the polarization behavior of interferometers are used to suggest how complex multisurfaced interferometers might be developed, what features affect their behavior most strongly, and how this behavior might be controlled. Those aspects of the Michelson interferometer important to its use as a high resolution spectral device are outlined and expressions relating the physical features of the interferometer and the spectral features of the radiation passing through the instrument, to the form of the observed interference pattern are derived. The sensitivity of the WAMI to misalignments in its optical components is explored, and quantitative estimations of the effects of these misalignments made. A working WAMI with cube corners instead of plane mirrors was constructed and is described. The theoretical notions outlined above are applied to this instrument and found to account for most of its features. A general digital procedure is developed for the analysis of the observed interference fringes which permits an estimation of the amplitude, visibility and phase of the fringes. This instrument was taken to Bird, northern Manitoba as part of the ground based support for the Auroral Rocket and Image Excitation Study (ARIES) rocket campaign. Doppler shifts and linewidth variations in O(^1 D) and O(^1S) emissions in the aurora were observed during several nights and constitute the first synoptic wind measurements taken with a WAMI. The

  10. Attenuated Vector Tomography -- An Approach to Image Flow Vector Fields with Doppler Ultrasonic Imaging

    International Nuclear Information System (INIS)

    Huang, Qiu; Peng, Qiyu; Huang, Bin; Cheryauka, Arvi; Gullberg, Grant T.

    2008-01-01

    The measurement of flow obtained using continuous wave Doppler ultrasound is formulated as a directional projection of a flow vector field. When a continuous ultrasound wave bounces against a flowing particle, a signal is backscattered. This signal obtains a Doppler frequency shift proportional to the speed of the particle along the ultrasound beam. This occurs for each particle along the beam, giving rise to a Doppler velocity spectrum. The first moment of the spectrum provides the directional projection of the flow along the ultrasound beam. Signals reflected from points further away from the detector will have lower amplitude than signals reflected from points closer to the detector. The effect is very much akin to that modeled by the attenuated Radon transform in emission computed tomography.A least-squares method was adopted to reconstruct a 2D vector field from directional projection measurements. Attenuated projections of only the longitudinal projections of the vector field were simulated. The components of the vector field were reconstructed using the gradient algorithm to minimize a least-squares criterion. This result was compared with the reconstruction of longitudinal projections of the vector field without attenuation. If attenuation is known, the algorithm was able to accurately reconstruct both components of the full vector field from only one set of directional projection measurements. A better reconstruction was obtained with attenuation than without attenuation implying that attenuation provides important information for the reconstruction of flow vector fields.This confirms previous work where we showed that knowledge of the attenuation distribution helps in the reconstruction of MRI diffusion tensor fields from fewer than the required measurements. In the application of ultrasound the attenuation distribution is obtained with pulse wave transmission computed tomography and flow information is obtained with continuous wave Doppler

  11. Current recommendations for the study of carotid stenosis by doppler ultrasound and other imaging techniques

    International Nuclear Information System (INIS)

    Perez Matamoros, Angelica

    2012-01-01

    Ischemic cerebrovascular disease has been one of the most frequent causes of death from chronic disease, as well as cause of long-term disabilities, in both the United States, and in Latin American countries during recent years. It is therefore, important to know about it. An updated review of international recommendations to the Costa Rican health system is performed for carotid imaging study in patients at risk of accidents and ischemic cerebrovascular disease; with special emphasis on carotid Doppler ultrasonography, due to its wide availability in the medical field Costa Rican. Furthermore, certain relevant concepts of other imaging techniques currently available are listed to determine the appropriate choice of each method according to the individual patient's condition, such as conventional angiography and tomographic angiography [es

  12. Doppler laser imaging predicts response to topical minoxidil in the treatment of female pattern hair loss.

    Science.gov (United States)

    McCoy, J; Kovacevic, M; Situm, M; Stanimirovic, A; Bolanca, Z; Goren, A

    2016-01-01

    Topical minoxidil is the only drug approved by the US FDA for the treatment of female pattern hair loss. Unfortunately, following 16 weeks of daily application, less than 40% of patients regrow hair. Several studies have demonstrated that sulfotransferase enzyme activity in plucked hair follicles predicts topical minoxidil response in female pattern hair loss patients. However, due to patients’ discomfort with the procedure, and the time required to perform the enzymatic assay it would be ideal to develop a rapid, non-invasive test for sulfotransferase enzyme activity. Minoxidil is a pro-drug converted to its active form, minoxidil sulfate, by sulfotransferase enzymes in the outer root sheath of hair. Minoxidil sulfate is the active form required for both the promotion of hair regrowth and the vasodilatory effects of minoxidil. We thus hypothesized that laser Doppler velocimetry measurement of scalp blood perfusion subsequent to the application of topical minoxidil would correlate with sulfotransferase enzyme activity in plucked hair follicles. In this study, plucked hair follicles from female pattern hair loss patients were analyzed for sulfotransferase enzyme activity. Additionally, laser Doppler velocimetry was used to measure the change in scalp perfusion at 15, 30, 45, and 60 minutes, after the application of minoxidil. In agreement with our hypothesis, we discovered a correlation (r=1.0) between the change in scalp perfusion within 60 minutes after topical minoxidil application and sulfotransferase enzyme activity in plucked hairs. To our knowledge, this is the first study demonstrating the feasibility of using laser Doppler imaging as a rapid, non-invasive diagnostic test to predict topical minoxidil response in the treatment of female pattern hair loss.

  13. The utility of ultrasound superb microvascular imaging for evaluation of breast tumour vascularity: comparison with colour and power Doppler imaging regarding diagnostic performance.

    Science.gov (United States)

    Park, A Y; Seo, B K; Woo, O H; Jung, K S; Cho, K R; Park, E K; Cha, S H; Cha, J

    2018-03-01

    To investigate the utility of superb microvascular imaging (SMI) for evaluating the vascularity of breast masses in comparison with colour or power Doppler ultrasound (US) and the effect on diagnostic performance. A total of 191 biopsy-proven masses (99 benign and 92 malignant) in 166 women with greyscale, colour Doppler, power Doppler, and SMI images were enrolled in this retrospective study. Three radiologists analysed the vascular images using a three-factor scoring system to evaluate the number, morphology, and distribution of tumour vessels. They assessed the Breast Imaging-Reporting and Data System categories for greyscale US alone and combinations of greyscale US and each type of vascular US. The Kruskal-Wallis test was performed and the area under the receiver-operating characteristic curve (AUC) measured. On SMI, vascular scores were compared between benign and malignant masses and the optimal cut-off value for the overall score was determined. SMI showed higher vascular scores than colour or power Doppler US and malignant masses had higher scores than benign masses (ppower Doppler US (AUC, 0.815 versus 0.774, 0.789, 0.791; ppower Doppler US for characterising the vascularity in breast masses and improving diagnostic performance. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  14. Clinically low-risk prostate cancer: evaluation with transrectal doppler ultrasound and functional magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Maria Inês Novis

    2011-01-01

    Full Text Available OBJECTIVES: To evaluate transrectal ultrasound, amplitude Doppler ultrasound, conventional T2-weighted magnetic resonance imaging, spectroscopy and dynamic contrast-enhanced magnetic resonance imaging in localizing and locally staging low-risk prostate cancer. INTRODUCTION: Prostate cancer has been diagnosed at earlier stages and the most accepted classification for low-risk prostate cancer is based on clinical stage T1c or T2a, Gleason score <6, and prostate-specific antigen (PSA <10 ng/ml. METHODS: From 2005 to 2006, magnetic resonance imaging was performed in 42 patients, and transrectal ultrasound in 26 of these patients. Seven patients were excluded from the study. Mean patient age was 64.94 years and mean serum PSA was 6.05 ng/ml. The examinations were analyzed for tumor identification and location in prostate sextants, detection of extracapsular extension, and seminal vesicle invasion, using surgical pathology findings as the gold standard. RESULTS: Sixteen patients (45.7% had pathologically proven organ-confined disease, 11 (31.4% had positive surgical margin, 8 (28.9% had extracapsular extension, and 3 (8.6% presented with extracapsular extension and seminal vesicle invasion. Sensitivity, specificity, positive predictive value (PPV, negative predictive value (NPV and accuracy values for localizing low-risk prostate cancer were 53.1%, 48.3%, 63.4%, 37.8% and 51.3% for transrectal ultrasound; 70.4%, 36.2%, 65.1%, 42.0% and 57.7% for amplitude Doppler ultrasound; 71.5%, 58.9%, 76.6%, 52.4% and 67.1% for magnetic resonance imaging; 70.4%, 58.7%, 78.4%, 48.2% and 66.7% for magnetic resonance spectroscopy; 67.2%, 65.7%, 79.3%, 50.6% and 66.7% for dynamic contrast-enhanced magnetic resonance imaging, respectively. Sensitivity, specificity, PPV, NPV and accuracy values for detecting extracapsular extension were 33.3%, 92%, 14.3%, 97.2% and 89.7% for transrectal ultrasound and 50.0%, 77.6%, 13.7%, 95.6% and 75.7% for magnetic resonance imaging

  15. Doppler Spectrum-Based NRCS Estimation Method for Low-Scattering Areas in Ocean SAR Images

    Directory of Open Access Journals (Sweden)

    Hui Meng

    2017-02-01

    Full Text Available The image intensities of low-backscattering areas in synthetic aperture radar (SAR images are often seriously contaminated by the system noise floor and azimuthal ambiguity signal from adjacent high-backscattering areas. Hence, the image intensity of low-backscattering areas does not correctly reflect the backscattering intensity, which causes confusion in subsequent image processing or interpretation. In this paper, a method is proposed to estimate the normalized radar cross-section (NRCS of low-backscattering area by utilizing the differences between noise, azimuthal ambiguity, and signal in the Doppler frequency domain of single-look SAR images; the aim is to eliminate the effect of system noise and azimuthal ambiguity. Analysis shows that, for a spaceborne SAR with a noise equivalent sigma zero (NESZ of −25 dB and a single-look pixel of 8 m × 5 m, the NRCS-estimation precision of this method can reach −38 dB at a resolution of 96 m × 100 m. Three examples are given to validate the advantages of this method in estimating the low NRCS and the filtering of the azimuthal ambiguity.

  16. Cardiovascular assessment of patients with Ullrich-Turner's Syndrome on Doppler echocardiography and magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Castro Ana Valéria Barros de

    2002-01-01

    Full Text Available OBJECTIVE: To assess the cardiovascular features of Ullrich-Turner's syndrome using echocardiography and magnetic resonance imaging, and to correlate them with the phenotype and karyotype of the patients. The diagnostic concordance between the 2 methods was also assessed. METHODS: Fifteen patients with the syndrome were assessed by echocardiography and magnetic resonance imaging (cardiac chambers, valves, and aorta. Their ages ranged from 10 to 28 (mean of 16.7 years. The karyotype was analyzed in 11 or 25 metaphases of peripheral blood lymphocytes, or both. RESULTS: The most common phenotypic changes were short stature and spontaneous absence of puberal development (100%; 1 patient had a cardiac murmur. The karyotypes detected were as follows: 45,X (n=7, mosaics (n=5, and deletions (n=3. No echocardiographic changes were observed. In regard to magnetic resonance imaging, coarctation and dilation of the aorta were found in 1 patient, and isolated dilation of the aorta was found in 4 patients. CONCLUSION: The frequencies of coarctation and dilation of the aorta detected on magnetic resonance imaging were similar to those reported in the literature (5.5% to 20%, and 6.3% to 29%, respectively. This confirmed the adjuvant role of magnetic resonance imaging to Doppler echocardiography for diagnosing cardiovascular alterations in patients with Ullrich-Turner's syndrome.

  17. Magnetic Doppler imaging considering atmospheric structure modifications due to local abundances: a luxury or a necessity?

    Science.gov (United States)

    Kochukhov, O.; Wade, G. A.; Shulyak, D.

    2012-04-01

    Magnetic Doppler imaging is currently the most powerful method of interpreting high-resolution spectropolarimetric observations of stars. This technique has provided the very first maps of stellar magnetic field topologies reconstructed from time series of full Stokes vector spectra, revealing the presence of small-scale magnetic fields on the surfaces of Ap stars. These studies were recently criticised by Stift et al., who claimed that magnetic inversions are not robust and are seriously undermined by neglecting a feedback on the Stokes line profiles from the local atmospheric structure in the regions of enhanced metal abundance. We show that Stift et al. misinterpreted published magnetic Doppler imaging results and consistently neglected some of the most fundamental principles behind magnetic mapping. Using state-of-the-art opacity sampling model atmosphere and polarized radiative transfer codes, we demonstrate that the variation of atmospheric structure across the surface of a star with chemical spots affects the local continuum intensity but is negligible for the normalized local Stokes profiles except for the rare situation of a very strong line in an extremely Fe-rich atmosphere. For the disc-integrated spectra of an Ap star with extreme abundance variations, we find that the assumption of a mean model atmosphere leads to moderate errors in Stokes I but is negligible for the circular and linear polarization spectra. Employing a new magnetic inversion code, which incorporates the horizontal variation of atmospheric structure induced by chemical spots, we reconstructed new maps of magnetic field and Fe abundance for the bright Ap star α2 CVn. The resulting distribution of chemical spots changes insignificantly compared to the previous modelling based on a single model atmosphere, while the magnetic field geometry does not change at all. This shows that the assertions by Stift et al. are exaggerated as a consequence of unreasonable assumptions and

  18. In-vivo imaging of blood flow in human retinal vessels using color Doppler optical coherence tomography

    Science.gov (United States)

    Yazdanfar, Siavash; Rollins, Andrew M.; Izatt, Joseph A.

    1999-04-01

    Quantification of retinal blood flow may lead to a better understanding of the progression and treatment of several ocular disorders, including diabetic retinopathy, age- related macular degeneration, and glaucoma. Current techniques, such as fluorescein angiography and laser Doppler velocimetry are limited, failing to provide sufficient information to the clinician. Color Doppler optical coherence tomography (CDOCT) is a novel technique using coherent heterodyne detection for simultaneous cross- sectional imaging of tissue microstructure and blood flow. This technique is capable of high spatial and velocity resolution imaging in highly scattering media. We implemented CDOCT for retinal blood flow mapping in human subjects. No dilation of the pupil was necessary. CDOCT is demonstrated for determining bidirectional flow in sub- 100micrometers diameter vessels in the retina. Additionally, we calculated Doppler broadening using the variance of depth- resolved spectra to identify regions with large velocity gradients within the Xenopus heart. This technique may be useful in quantifying local tissue perfusion in highly vascular retinal tissue.

  19. Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows

    Science.gov (United States)

    Allen, M. G.; Davis, S. J.; Kessler, W. J.; Sonnenfroh, D. M.

    1992-01-01

    The application of Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows is analyzed. Focussing on fluorescence of the OH molecule in typical H2-air Scramjet flows, the effects of uncharacterized variations in temperature, pressure, and collisional partner composition across the measurement plane are examined. Detailed measurements of the (1,0) band OH lineshape variations in H2-air combustions are used, along with single-pulse and time-averaged measurements of an excimer-pumped dye laser, to predict the performance of a model velocimeter with typical Scramjet flow properties. The analysis demonstrates the need for modification and control of the laser bandshape in order to permit accurate velocity measurements in the presence of multivariant flow properties.

  20. Diagnostic accuracy of color Doppler flow imaging and Duplex US in peripheral arterial disease

    International Nuclear Information System (INIS)

    Karmel, M.I.; Polak, J.F.; Whittemore, A.D.; Mannick, J.A.; Donaldson, M.C.; O'Leary, D.H.

    1988-01-01

    Color Doppler flow imaging (5 MHz) and Duplex US were used in a prospective examination of 154 arterial segments in the lower extremities of 11 symptomatic patients. Each extremity was divided into seven arterial segments (common femoral, profunda femoral, proximal, middle, and distal superficial femoral, and proximal and distal popliteal arteries). Arterial maps were drawn for each patient and compared with the arteriograms. Seventeen significant stenoses and 18 complete occlusions were predicted and confirmed by means of arteriography. Four significant stenoses and four occlusions were predicted and not confirmed. One hundred nine normal arterial segments were correctly predicted. No significant stenoses or occlusions were missed. Prospective identification of the severity and location of disease can help to optimize both the angiographic approach and hospital services utilization

  1. Particle image and acoustic Doppler velocimetry analysis of a cross-flow turbine wake

    Science.gov (United States)

    Strom, Benjamin; Brunton, Steven; Polagye, Brian

    2017-11-01

    Cross-flow turbines have advantageous properties for converting kinetic energy in wind and water currents to rotational mechanical energy and subsequently electrical power. A thorough understanding of cross-flow turbine wakes aids understanding of rotor flow physics, assists geometric array design, and informs control strategies for individual turbines in arrays. In this work, the wake physics of a scale model cross-flow turbine are investigated experimentally. Three-component velocity measurements are taken downstream of a two-bladed turbine in a recirculating water channel. Time-resolved stereoscopic particle image and acoustic Doppler velocimetry are compared for planes normal to and distributed along the turbine rotational axis. Wake features are described using proper orthogonal decomposition, dynamic mode decomposition, and the finite-time Lyapunov exponent. Consequences for downstream turbine placement are discussed in conjunction with two-turbine array experiments.

  2. Unequal-Arms Michelson Interferometers

    Science.gov (United States)

    Tinto, Massimo; Armstrong, J. W.

    2000-01-01

    Michelson interferometers allow phase measurements many orders of magnitude below the phase stability of the laser light injected into their two almost equal-length arms. If, however, the two arms are unequal, the laser fluctuations can not be removed by simply recombining the two beams. This is because the laser jitters experience different time delays in the two arms, and therefore can not cancel at the photo detector. We present here a method for achieving exact laser noise cancellation, even in an unequal-arm interferometer. The method presented in this paper requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam. By linearly combining the two data sets with themselves, after they have been properly time shifted, we show that it is possible to construct a new data set that is free of laser fluctuations. An application of this technique to future planned space-based laser interferometer detector3 of gravitational radiation is discussed.

  3. Cost-effectiveness of laser Doppler imaging in burn care in the Netherlands

    Directory of Open Access Journals (Sweden)

    Hop M Jenda

    2013-02-01

    Full Text Available Abstract Background Early accurate assessment of burn depth is important to determine the optimal treatment of burns. The method most used to determine burn depth is clinical assessment, which is the least expensive, but not the most accurate. Laser Doppler imaging (LDI is a technique with which a more accurate (>95% estimate of burn depth can be made by measuring the dermal perfusion. The actual effect on therapeutic decisions, clinical outcomes and the costs of the introduction of this device, however, are unknown. Before we decide to implement LDI in Dutch burn care, a study on the effectiveness and cost-effectiveness of LDI is necessary. Methods/design A multicenter randomised controlled trial will be conducted in the Dutch burn centres: Beverwijk, Groningen and Rotterdam. All patients treated as outpatient or admitted to a burn centre within 5 days post burn, with burns of indeterminate depth (burns not obviously superficial or full thickness and a total body surface area burned of ≤ 20% are eligible. A total of 200 patients will be included. Burn depth will be diagnosed by both clinical assessment and laser Doppler imaging between 2–5 days post burn in all patients. Subsequently, patients are randomly divided in two groups: ‘new diagnostic strategy’ versus ‘current diagnostic strategy’. The results of the LDI-scan will only be provided to the treating clinician in the ‘new diagnostic strategy’ group. The main endpoint is the effect of LDI on wound healing time. In addition we measure: a the effect of LDI on other patient outcomes (quality of life, scar quality, b the effect of LDI on diagnostic and therapeutic decisions, and c the effect of LDI on total (medical and non-medical costs and cost-effectiveness. Discussion This trial will contribute to our current knowledge on the use of LDI in burn care and will provide evidence on its cost-effectiveness. Trial registration NCT01489540

  4. Laser Doppler imaging, thermographic imaging, and tissue oxygen saturation measurements detect early skin reactions during breast radiotherapy

    Science.gov (United States)

    Harrison, David K.; Harrison, Eileen M.; Newton, David J.; Windsor, Phyllis M.

    2001-05-01

    A range of acute skin reactions, ranging from mild erythema to moist desquamation, can be seen in patients receiving standard fractionated radiotherapy to the breast for conservation therapy of breast carcinoma. In a number of cases these reactions can cause considerable discomfort and seriously affect the patient's quality of life. In previous studies we have used the techniques of laser Doppler imaging, digital thermographic imaging and lightguide spectrophotometry to study oxygen supply and blood flow in inflammatory reactions induced experimentally in forearm skin. The present study is an attempt to use the same techniques to investigate whether any or all of them can detect changes in breast skin very early on in the course of radiotherapy treatment. A further aim of the longer term study is to investigate to what extent these early changes may be able to predict the occurrence later of severe acute or delayed reactions.

  5. Investigating the effect of a targets time-varying doppler generating axis of rotation on isar image distortion

    CSIR Research Space (South Africa)

    Abdul Gaffar, MY

    2007-10-01

    Full Text Available , contributes to ISAR image blurring. Quaternion algebra is used to aid the characterisation of a time-varying Doppler generating axis of rotation on the migration through cross-range cells. Real motion data of a sailing yacht is used to examine the effects of 3...

  6. Perfusion of burn wounds assessed by Laser Doppler Imaging is related to burn depth and healing time

    NARCIS (Netherlands)

    Kloppenberg, FWH; Beerthuizen, GIJM; ten Duis, H. J.

    Average perfusion in various burn wounds was assessed using Laser Doppler Imaging (LDI). The time necessary for a complete healing of the wound was compared to the results of the LDI measurements. A certain depth of burn was associated with a typical pattern of perfusion in the course of time. There

  7. Asset of Doppler Vascular Imaging and CTA in Diagnosis of Coagulation Disturbances in Pregnancy and Puerperium - case study

    International Nuclear Information System (INIS)

    Leskova, M.; Slobodnikova, J.

    2009-01-01

    Importance of earlier diagnosis of trombophilia. Trombophilia - its impression on development venous trombosis specially in the case of young woman with repeated spontaneous abortions. Value of not-invasive imaging methods (Doppler sonography and CT angiography ) in diagnosis deep phlebotrombosis. (author)

  8. Standardization of the first-trimester fetal cardiac examination using spatiotemporal image correlation with tomographic ultrasound and color Doppler imaging.

    Science.gov (United States)

    Turan, S; Turan, O M; Ty-Torredes, K; Harman, C R; Baschat, A A

    2009-06-01

    The challenges of the first-trimester examination of the fetal heart may in part be overcome by technical advances in three-dimensional (3D) ultrasound techniques. Our aim was to standardize the first-trimester 3D imaging approach to the cardiac examination to provide the most consistent and accurate display of anatomy. Low-risk women with normal findings on first-trimester screening at 11 to 13 + 6 weeks had cardiac ultrasound using the following sequence: (1) identification of the four-chamber view; (2) four-dimensional (4D) volume acquisition with spatiotemporal image correlation (STIC) and color Doppler imaging (angle = 20 degrees, sweep 10 s); (3) offline, tomographic ultrasound imaging (TUI) analysis with standardized starting plane (four-chamber view), slice number and thickness; (4) assessment of fetal cardiac anatomy (four-chamber view, cardiac axis, size and symmetry, atrioventricular valves, great arteries and descending aorta) with and without color Doppler. 107 consecutive women (age, 16-42 years, body mass index 17.2-50.2 kg/m(2)) were studied. A minimum of three 3D volumes were obtained for each patient, transabdominally in 91.6%. Fetal motion artifact required acquisition of more than three volumes in 20%. The median time for TUI offline analysis was 100 (range, 60-240) s. Individual anatomic landmarks were identified in 89.7-99.1%. Visualization of all structures in one panel was observed in 91 patients (85%). Starting from a simple two-dimensional cardiac landmark-the four-chamber view-the standardized STIC-TUI technique enables detailed segmental cardiac evaluation of the normal fetal heart in the first trimester. (c) 2009 ISUOG.

  9. Evaluation of left ventricular function in obese children without hypertension by a tissue Doppler imaging study.

    Science.gov (United States)

    Ghandi, Yazdan; Sharifi, Mehrzad; Habibi, Danial; Dorreh, Fatemeh; Hashemi, Mojtaba

    2018-01-01

    The prevalence of obesity is increasing worldwide. Obese children without hypertension are becoming an important health challenge. Complications of obesity in adults are well established, but in obese children, cardiac dysfunction has not been reported clinically. The present crosssectional study investigates subclinical systolic and diastolic dysfunction using echocardiographic modalities. Twentyfive youngsters with body mass index (BMI) >30 and 25 healthy children with BMI <25 were assigned into case and control group, respectively. In all participants, complete cardiovascular examination, electrocardiography, and echocardiography were fulfilled. Echocardiography surveys included standard, pulsed wave Doppler (PWD), and tissue Doppler imaging (TDI). SPSS software, version 24. The two groups were matched for age and sex. The resting heart rate and blood pressure were markedly higher in the obese group ( P = 0.0001) though they were within the normal range in either category. Ejection fraction in the two groups was similar. Left ventricular (LV) mass ( P = 0.0001), LV mass index ( P = 0.029), left atrialtoaortic diameter ratio ( P = 0.0001), and LV enddiastolic diameter ( P = 0.008) were significantly greater in the case group, indicating cardiomegaly and subclinical systolic and diastolic dysfunction. Except for the aortic velocity, all PWD variables were considerably lower in the case group, suggesting subclinical diastolic dysfunction. All TDI parameters varied significantly between the two categories. There was a direct correlation between isovolumetric relaxation time and BMI. Obesity in children without hypertension is associated with subclinical systolic and diastolic cardiac dysfunction. We propose the evaluation of blood pressure as well as myocardial performance using PWD and TDI in all obese children without hypertension, regularly.

  10. Automated synovium segmentation in doppler ultrasound images for rheumatoid arthritis assessment

    Science.gov (United States)

    Yeung, Pak-Hei; Tan, York-Kiat; Xu, Shuoyu

    2018-02-01

    We need better clinical tools to improve monitoring of synovitis, synovial inflammation in the joints, in rheumatoid arthritis (RA) assessment. Given its economical, safe and fast characteristics, ultrasound (US) especially Doppler ultrasound is frequently used. However, manual scoring of synovitis in US images is subjective and prone to observer variations. In this study, we propose a new and robust method for automated synovium segmentation in the commonly affected joints, i.e. metacarpophalangeal (MCP) and metatarsophalangeal (MTP) joints, which would facilitate automation in quantitative RA assessment. The bone contour in the US image is firstly detected based on a modified dynamic programming method, incorporating angular information for detecting curved bone surface and using image fuzzification to identify missing bone structure. K-means clustering is then performed to initialize potential synovium areas by utilizing the identified bone contour as boundary reference. After excluding invalid candidate regions, the final segmented synovium is identified by reconnecting remaining candidate regions using level set evolution. 15 MCP and 15 MTP US images were analyzed in this study. For each image, segmentations by our proposed method as well as two sets of annotations performed by an experienced clinician at different time-points were acquired. Dice's coefficient is 0.77+/-0.12 between the two sets of annotations. Similar Dice's coefficients are achieved between automated segmentation and either the first set of annotations (0.76+/-0.12) or the second set of annotations (0.75+/-0.11), with no significant difference (P = 0.77). These results verify that the accuracy of segmentation by our proposed method and by clinician is comparable. Therefore, reliable synovium identification can be made by our proposed method.

  11. Analysis of fetal movements by Doppler actocardiogram and fetal B-mode imaging.

    Science.gov (United States)

    Maeda, K; Tatsumura, M; Utsu, M

    1999-12-01

    We have presented that fetal surveillance may be enhanced by use of the fetal actocardiogram and by computerized processing of fetal motion as well as fetal B-mode ultrasound imaging. Ultrasonic Doppler fetal actogram is a sensitive and objective method for detecting and recording fetal movements. Computer processing of the actograph output signals enables powerful, detailed, and convenient analysis of fetal physiologic phenomena. The actocardiogram is a useful measurement tool not only in fetal behavioral studies but also in evaluation of fetal well-being. It reduces false-positive, nonreactive NST and false-positive sinusoidal FHR pattern. It is a valuable tool to predict fetal distress. The results of intrapartum fetal monitoring are further improved by the antepartum application of the actocardiogram. Quantified fetal motion analysis is a useful, objective evaluation of the embryo and fetus. This method allows monitoring of changes in fetal movement, as well as frequency, amplitude, and duration. Furthermore, quantification of fetal motion enables evaluation of fetal behavior states and how these states relate to other measurements, such as changes in FHR. Numeric analysis of both fetal actogram and fetal motion from B-mode images is a promising application in the correlation of fetal activity or behavior with other fetal physiologic measurements.

  12. Doppler optical coherence tomography imaging of local fluid flow and shear stress within microporous scaffolds

    Science.gov (United States)

    Jia, Yali; Bagnaninchi, Pierre O.; Yang, Ying; Haj, Alicia El; Hinds, Monica T.; Kirkpatrick, Sean J.; Wang, Ruikang K.

    2009-05-01

    Establishing a relationship between perfusion rate and fluid shear stress in a 3D cell culture environment is an ongoing and challenging task faced by tissue engineers. We explore Doppler optical coherence tomography (DOCT) as a potential imaging tool for in situ monitoring of local fluid flow profiles inside porous chitosan scaffolds. From the measured fluid flow profiles, the fluid shear stresses are evaluated. We examine the localized fluid flow and shear stress within low- and high-porosity chitosan scaffolds, which are subjected to a constant input flow rate of 0.5 ml.min-1. The DOCT results show that the behavior of the fluid flow and shear stress in micropores is strongly dependent on the micropore interconnectivity, porosity, and size of pores within the scaffold. For low-porosity and high-porosity chitosan scaffolds examined, the measured local fluid flow and shear stress varied from micropore to micropore, with a mean shear stress of 0.49+/-0.3 dyn.cm-2 and 0.38+/-0.2 dyn.cm-2, respectively. In addition, we show that the scaffold's porosity and interconnectivity can be quantified by combining analyses of the 3D structural and flow images obtained from DOCT.

  13. Tissue Doppler imaging of carotid plaque wall motion: a pilot study

    Directory of Open Access Journals (Sweden)

    Naylor A Ross

    2003-12-01

    Full Text Available Abstract Background Studies suggest the physical and mechanical properties of vessel walls and plaque may be of clinical value in the diagnosis and treatment of cardiovascular atherosclerotic disease. The purpose of this pilot study was to investigate the potential clinical application of ultrasound Tissue Doppler Imaging (TDI of Arterial Wall Motion (AWM and to quantify simple wall motion indices in normal and diseased carotid arteries. Methods 224 normal and diseased carotid arteries (0–100% stenoses were imaged in 126 patients (age 25–88 years, mean 68 ± 11. Longitudinal sections of the carotid bifurcation were imaged using a Philips HDI5000 scanner and L12-5 probe under optimized TDI settings. Temporal and spatial AWMs were analyzed to evaluate the vessel wall displacements and spatial gradients at peak systole averaged over 5 cardiac cycles. Results AWM data were successfully extracted in 91% of cases. Within the carotid bifurcation/plaque region, the maximum wall dilation at peak systole ranged from -100 to 750 microns, mean 335 ± 138 microns. Maximum wall dilation spatial gradients ranged 0–0.49, mean 0.14 ± 0.08. The AWM parameters showed a wide variation and had poor correlation with stenoses severity. Case studies illustrated a variety of pertinent qualitative and quantitative wall motion features related to the biophysics of arterial disease. Conclusion Our clinical experience, using a challenging but realistic imaging protocol, suggests the use of simple quantitative AWM measures may have limitations due to high variability. Despite this, pertinent features of AWM in normal and diseased arteries demonstrate the potential clinical benefit of the biomechanical information provided by TDI.

  14. Double-grating interferometer with a one-to-one correspondence with a Michelson interferometer.

    Science.gov (United States)

    Xu, Yande; Sasaki, Osami; Suzuki, Takamasa

    2003-10-01

    We describe a double-grating interferometer that has a one-to-one correspondence with a Michelson interferometer. The half spatial periods of the gratings are equivalent to the wavelengths of the interferometer. The widths of the interference fringes can be changed easily. The intensity distribution of the interference pattern is independent of the wavelength of the light source used. The surface profile of an object can be measured because two interference beams can coincide precisely on the image plane of the object. The measuring range is much larger than that of a Michelson interferometer.

  15. Detection of Early Right Ventricular Dysfunction in Young Patients With Thalassemia Major Using Tissue Doppler Imaging

    Science.gov (United States)

    Bornaun, Helen; Dedeoglu, Reyhan; Oztarhan, Kazim; Dedeoglu, Savas; Erfidan, Erkan; Gundogdu, Muge; Aydogan, Gonul; Cengiz, Dicle

    2016-01-01

    Background Myocardial iron overload is the most common cause of mortality in patients with thalassemia major (TM), also known as beta-thalassemia. T2* cardiovascular magnetic resonance imaging (MRI) is the best way of monitoring cardiac iron, and new echocardiographic techniques can be used to assess cardiac function. Objectives The aim of this study was to assess the systolic and diastolic right ventricular (RV) function of patients with TM using tissue Doppler imaging (TDI) and to determine whether this echocardiographic technique is an adequate diagnostic tool for the screening and detection of subclinical cardiac dysfunction. Patients and Methods Eighty-four patients with TM were evaluated by conventional echocardiography and pulse-wave TDI. The data of the TM group (Group 1) were compared with that of 85 age- and sex-matched healthy controls (Group 2). Cardiovascular T2* MRI examinations were performed in 49 of the 85 patients. Results The patients with TM had significantly lower values for weight, height, body mass index, systolic arterial pressure, deceleration time, E’/A’, and ejection time (ET) than the controls. Group 1 also had significantly higher values for peak early diastolic velocity (E) over peak late diastolic velocity (A), peak early diastolic velocity of TDI (E’), peak late diastolic velocity of TDI (A’), E/E’, isovolumetric relaxation time, isovolumetric contraction time, and RV magnetic perfusion imaging (MPI) than Group 2. Conclusions RV diastolic dysfunction occurs before systolic deterioration in patients with TM and cannot be screened with conventional echocardiographic techniques. In routine practice, TDI measurements, MPI (for global function) and the E/E’ parameter (for diastolic function) can be used to screen and detect early RV dysfunction. PMID:27617076

  16. Michelson-Morley in Einstein's elevators

    Science.gov (United States)

    Pierce, Fred; Pierce, Ayal

    2010-02-01

    Experiments are proposed in which a Michelson-Morley interferometer is placed in Einstein's thought experiments where elevators are subjected to varied accelerated fields. Unbeknownst to the observers inside the elevators, they are placed in different circumstances: on the surface of the Earth, in free fall, in space distant from any mass, and inside a rotating space station. By use of not one, but two objects, the observer will be challenged to determine the nature and shape of the accelerated field, if any, inside the elevator. It will be demonstrated that the nature of the accelerated field can be determined easily from inside the elevator by the motion of the two objects released by the observer. It will also be shown that, for the elevator on the space station which is generating an ``artificial gravity'' field by rotation, Michelson-Morley would have the same null result as on Earth. However, the Michelson-Morley experiment is adapted so that in addition to the two horizontal arms of the interferometer (parallel to the floor of the elevator) a vertical arm is added perpendicular to the floor facing towards the ceiling. Such a vertical arm added to the Michelson-Morley experiment adds a new dimension to examining each accelerated field, including gravity. )

  17. Thermoluminescence spectra measured with a Michelson interferometer

    International Nuclear Information System (INIS)

    Haschberger, P.

    1991-01-01

    A Michelson interferometer was redesigned to prove its capabilities in the measurement of short-lived, low-intensity thermoluminescence spectra. Interferograms are collected during heating up the thermoluminescent probe in a heater plate. A personal computer controls the data acquisition and processes the Fourier transform. As the results show, even a comparatively simple and limited setup leads to relevant and reproducible spectra. (author)

  18. The effect of rotations on Michelson interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Maraner, Paolo, E-mail: pmaraner@unibz.it

    2014-11-15

    In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations.

  19. The effect of rotations on Michelson interferometers

    International Nuclear Information System (INIS)

    Maraner, Paolo

    2014-01-01

    In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations

  20. A Michelson interferometer for ultracold neutrons

    International Nuclear Information System (INIS)

    Steyerl, A.; Malik, S.S.; Steinhauser, K.A.; Berger, L.

    1979-01-01

    We propose a neutron Michelson Interferometer installed within a focussing 'gravity diffractometer' for ultracold neutrons. In this arrangement the expected interference pattern depends only on the well-defined vertical component of neutron wavevector. Possible applications of such an interferometer are discussed. (orig.)

  1. Michelson wide-field stellar interferometry

    NARCIS (Netherlands)

    Montilla, I.

    2004-01-01

    The main goal of this thesis is to develop a system to permit wide field operation of Michelson Interferometers. A wide field of view is very important in applications such as the observation of extended or multiple objects, the fringe acquisition and/ or tracking on a nearby unresolved object, and

  2. Algorithms for Unequal-Arm Michelson Interferometers

    Science.gov (United States)

    Giampieri, Giacomo; Hellings, Ronald W.; Tinto, Massimo; Bender, Peter L.; Faller, James E.

    1994-01-01

    A method of data acquisition and data analysis is described in which the performance of Michelson-type interferometers with unequal arms can be made nearly the same as interferometers with equal arms. The method requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam.

  3. Power Doppler Imaging in Acute Renal Vein Occlusion and Recanalization: a Canine Model

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, So-Young; Kim, In-One; Kim, Young-Il; Lee, Kyoung Ho; Lee, Min Woo; Youn, Byung Jae; Kim, Woo Sun; Yeon, Kyung Mo [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2008-04-15

    Objective : To evaluate the dynamic changes of the power Doppler (PD) in acute renal vein occlusion and recanalization in a canine model. Materials and Methods : We performed a PD of the kidney during graded renal vein occlusion and recanalization induced by balloon inflation and deflation in nine dogs. The PD images were transferred to a personal computer, and the PD signals were quantified. Result : We observed the temporal change of the PD signal during renal vein occlusion and recanalization, with a decrease in the PD signal during occlusion and an increase during recanalization. The mean PD signal decreased gradually as the renal vein was occluded, and conversely increased gradually with sequential relief of occlusion. The sequential change of the mean value of the PD signal was statistically significant. Conclusion : The PD can detect a change in renal blood flow during acute renal vein occlusion and recanalization in a canine model. The PD may be used as a helpful tool for the early detection of acute renal vein thrombosis and the monitoring of renal perfusion.

  4. FIRST ZEEMAN DOPPLER IMAGING OF A COOL STAR USING ALL FOUR STOKES PARAMETERS

    International Nuclear Information System (INIS)

    Rosén, L.; Kochukhov, O.; Wade, G. A.

    2015-01-01

    Magnetic fields are ubiquitous in active cool stars, but they are in general complex and weak. Current Zeeman Doppler imaging (ZDI) studies of cool star magnetic fields chiefly employ circular polarization observations because linear polarization is difficult to detect and requires a more sophisticated radiative transfer modeling to interpret. But it has been shown in previous theoretical studies, and in the observational analyses of magnetic Ap stars, that including linear polarization in the magnetic inversion process makes it possible to correctly recover many otherwise lost or misinterpreted magnetic features. We have obtained phase-resolved observations in all four Stokes parameters of the RS CVn star II Peg at two separate epochs. Here we present temperature and magnetic field maps reconstructed for this star using all four Stokes parameters. This is the very first such ZDI study of a cool active star. Our magnetic inversions reveal a highly structured magnetic field topology for both epochs. The strength of some surface features is doubled or even quadrupled when linear polarization is taken into account. The total magnetic energy of the reconstructed field map also becomes about 2.1–3.5 times higher. The overall complexity is also increased as the field energy is shifted toward higher harmonic modes when four Stokes parameters are used. As a consequence, the potential field extrapolation of the four Stokes parameter ZDI results indicates that magnetic field becomes weaker at a distance of several stellar radii due to a decrease of the large-scale field component

  5. Study on Tei index of right ventricular by tissue doppler imaging and the observation point selection

    International Nuclear Information System (INIS)

    Luo Yinli; Wu Ji; Guo Shenglan; Zhang Di; Li Zhixian

    2009-01-01

    Objective: To explore the right ventricular (RV) Tei index in patients with pulmonary hypertension (PH) by tissue Doppler imaging (TDI), and to explore more accurate observation point to obtain Tei index of right ventricular. Methods: Assessment of RV Tei index values was performed in 95 patients with PH and 32 normal subjects. The 95 patients were grouped into 3 groups according to the severity of PH. Tei index values were obtained by TDI measurement from three observation points, the anterior tricuspid and septal tricuspid attachment points in the apical 4-chamber view and the posterior tricuspid attachment point in parasternal right heart 2-chamber review. Results: (1) RV Tel index values were measured at the three points of PH was higher than the normal significantly (P<0.05). (2) RV Tei index values of the three PH groups at he anterior tricuspid attachment had significant difference each other (P<0.05). RV Tei index values of low-grade and medium-grade PH groups at septal tricuspid and posterior tricuspid had no significant difference, but that of high-grade PH group were higher than the low-grade and medium-grade PH group. Conclusion: RV Tei index value was significantly increased in PH patients. The Tei index value measured by TDI at anterior tricuspid attachment point in apical 4-chamber view was better than that at septal tricuspid attachment point in the apical 4-chamber view and posterior' attachment of parasternal right heart 2-chamber. (authors)

  6. Scanning laser Doppler imaging may predict disease progression of localized scleroderma in children and young adults.

    Science.gov (United States)

    Shaw, L J; Shipley, J; Newell, E L; Harris, N; Clinch, J G; Lovell, C R

    2013-07-01

    Localized scleroderma is a rare but potentially disfiguring and disabling condition. Systemic treatment should be started early in those with active disease in key functional and cosmetic sites, but disease activity is difficult to determine clinically. Superficial blood flow has been shown to correlate with disease activity in localized scleroderma. To examine whether superficial blood flow measured by laser Doppler imaging (LDI) has the potential to predict disease progression and therefore select patients for early systemic treatment. A group of 20 individuals had clinical assessment and scanning LDI blood-flow measurements of 32 affected body sites. After a mean follow-up of 8.7 months their clinical outcome was compared with the results of the initial LDI assessment. Eleven out of 15 patients with an assessment of active LDI had progressed clinically, and 16 out of the 17 scans with inactive LDI assessment had not progressed, giving a positive predictive value of 73% and a negative predictive value of 94%. We believe that LDI can be a useful tool in predicting disease progression in localized scleroderma, and it may help clinicians to decide which patients to treat early. © 2013 The Authors BJD © 2013 British Association of Dermatologists.

  7. Skin perfusion evaluation between laser speckle contrast imaging and laser Doppler flowmetry

    Science.gov (United States)

    Humeau-Heurtier, Anne; Mahe, Guillaume; Durand, Sylvain; Abraham, Pierre

    2013-03-01

    In the biomedical field, laser Doppler flowmetry (LDF) and laser speckle contrast imaging (LSCI) are two optical techniques aiming at monitoring - non-invasively - the microvascular blood perfusion. LDF has been used for nearly 40 years whereas LSCI is a recent technique that overcomes some drawbacks of LDF. Both LDF and LSCI give perfusion assessments in arbitrary units. However, the possible relationship existing between perfusions given by LDF and by LSCI over large blood flow values has not been completely studied yet. We therefore herein evaluate the relationship between the LDF and LSCI perfusion values across a broad range of skin blood flows. For this purpose, LDF and LSCI data were acquired simultaneously on the forearm of 12 healthy subjects, at rest, during different durations of vascular occlusion and during reactive hyperemia. For the range of skin blood flows studied, the power function fits the data better than the linear function: powers for individual subjects go from 1.2 to 1.7 and the power is close to 1.3 when all the subjects are studied together. We thus suggest distinguishing perfusion values given by the two optical systems.

  8. Acute Effects of Hemodialysis on Left and Right Ventricular Function: A Doppler Tissue Imaging Study

    Directory of Open Access Journals (Sweden)

    Tansel Erol

    2012-08-01

    Full Text Available Purpose: Doppler tissue imaging (DTI allows noninvasive assessment of both left ventricular (LV and right ventricular (RV function. The aim of this study was to evaluate the effect of hemodialysis (HD on LV and RV function using DTI. Method: Our study group included 30 patients on chronic HD program (mean age 45 15 years. Myocardial (Sm, Em, Am and annular velocities (Ea, Aa were measured in several cardiac territories before and after HD. Results: After HD, Ea significantly reduced from 10.8 3.4 cm/s to 9.6 2.4 cm/s (p = 0.029. Patients exhibited a lower Em following HD in all measured territories. Em/Am ratio was also reduced for each LV wall investigated after HD in all measured territories. At the RV segments, Sm, Em, and Am decreased significantly in all measured territories. Em of the anterior wall was positively related to ultrafiltration volume (r = 0.25, p = 0.006, whereas the decrease of Sm of RV basal segment correlated with a decrease of diastolic blood pressure (r = 0.23, p < 0.01. Conclusion: Our data indicate that a single HD session is associated with acute changes of systolic and diastolic parameters of LV and RV. [Cukurova Med J 2012; 37(4.000: 215-222

  9. Power Doppler Imaging in Acute Renal Vein Occlusion and Recanalization: a Canine Model

    International Nuclear Information System (INIS)

    Yoo, So-Young; Kim, In-One; Kim, Young-Il; Lee, Kyoung Ho; Lee, Min Woo; Youn, Byung Jae; Kim, Woo Sun; Yeon, Kyung Mo

    2008-01-01

    Objective : To evaluate the dynamic changes of the power Doppler (PD) in acute renal vein occlusion and recanalization in a canine model. Materials and Methods : We performed a PD of the kidney during graded renal vein occlusion and recanalization induced by balloon inflation and deflation in nine dogs. The PD images were transferred to a personal computer, and the PD signals were quantified. Result : We observed the temporal change of the PD signal during renal vein occlusion and recanalization, with a decrease in the PD signal during occlusion and an increase during recanalization. The mean PD signal decreased gradually as the renal vein was occluded, and conversely increased gradually with sequential relief of occlusion. The sequential change of the mean value of the PD signal was statistically significant. Conclusion : The PD can detect a change in renal blood flow during acute renal vein occlusion and recanalization in a canine model. The PD may be used as a helpful tool for the early detection of acute renal vein thrombosis and the monitoring of renal perfusion

  10. Grey-scale and colour Doppler ultrasound versus magnetic resonance imaging for the prenatal diagnosis of placenta accreta.

    Science.gov (United States)

    Rezk, Mohamed Abd-Allah; Shawky, Mohamed

    2016-01-01

    To assess the effectiveness of grey-scale and colour Doppler ultrasound (US) versus magnetic resonance imaging (MRI) for the prenatal diagnosis of placenta accreta. A prospective observational study including a total of 74 patients with placenta previa and previous uterine scar (n = 74). Grey-scale and colour Doppler US was done followed by MRI by different observers to diagnose adherent placenta. Test validity of US and MRI were calculated. Maternal morbidity and mortality were also assessed. A total of 53 patients confirmed to have placenta accreta at operation. The overall sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of US was 94.34, 91.67, 96.15 and 88% compared to 96.08, 87.50, 94.23 and 91.3% for MRI, respectively. The most relevant US sign was turbulent blood flow by colour Doppler, while dark intra-placental band was the most sensitive MRI sign. Venous thromboembolism (1.3%), bladder injury (29.7%), ureteric injury (18.9%), postoperative fever (10.8%), admission to ICU (50%) and re-operation (31.1%). Placenta accreta can be successfully diagnosed by grey-scale and colour Doppler US. MRI would be more likely suggested for either posteriorly or laterally situated placenta previa in order to exclude placental invasion.

  11. Power Doppler ultrasonography for assessment of synovitis in the metacarpophalangeal joints of patients with rheumatoid arthritis: a comparison with dynamic magnetic resonance imaging

    DEFF Research Database (Denmark)

    Szkudlarek, Marcin; Court-Payen, M; Strandberg, C

    2001-01-01

    OBJECTIVE: To evaluate the effectiveness of power Doppler ultrasonography (PDUS) for assessing inflammatory activity in the metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA), using dynamic magnetic resonance imaging (MRI) as a reference method. METHODS: PDUS and dynamic ...

  12. The Contribution of Three-Dimensional Power Doppler Imaging in the Preoperative Assessment of Breast Tumors: A Preliminary Report

    Directory of Open Access Journals (Sweden)

    K. Kalmantis

    2009-01-01

    Methods. One hundred and twenty five women with clinically or mammographically suspicious findings were referred for 3D Power Doppler ultrasound prior to surgery. Histological diagnosis was conducted after surgery and compared with ultrasound findings. Sonographic criteria used for breast cancer diagnosis were based on a system that included morphological characteristics and criteria of the vascular pattern of a breast mass by Power Doppler imaging. Results. Seventy-two lesions were histopathologically diagnosed as benign and 53 tumors as malignant. Three-dimensional ultrasound identified 49 out of 53 histologically confirmed breast cancers resulting in a sensitivity of 92.4% and a specificity of 86.1% in diagnosing breast malignancy (PPV: 0.83, NPV:0.94. Conclusions. 3D ultrasonography is a valuable tool in identifying preoperatively the possibility of a tumor to be malignant.

  13. Transverse coherence measurement using a folded Michelson interferometer.

    Science.gov (United States)

    Dean, Jesse; Bercx, Martin; Nantel, Marc; Marjoribanks, Robin

    2007-06-01

    The transverse coherence of a 1 ps pulsed laser beam was measured using a technique involving a modified Michelson interferometer and separate reference images. Using this technique, the transverse coherence of a selected plane in the laser beam was determined, in this case at the exit of a channel in a metal foil self-drilled by the laser. Images of each arm were used as references. Through this technique, it is possible to use the interference patterns produced with uneven intensity distributions and for pulsed lasers on a single-shot basis. The results of these measurements were then shown to be in agreement with those obtained using a Young's double-slit setup.

  14. Pulsed-wave tissue Doppler imaging of the myocardium of cats with induced thyrotoxicosis Doppler tecidual pulsado do miocárdio de gatos com tirotoxicose induzida

    Directory of Open Access Journals (Sweden)

    Daniel Capucho de Oliveira

    2011-06-01

    Full Text Available Left ventricular myocardial motion was quantified using pulsed-wave tissue Doppler imaging (PW-TDI in nine adult cats before and after thyrotoxicosis induction. In order to induce thyrotoxicosis, all cats were given 150µg kg-1 of levothyroxine sodium as a single oral dose each day for 10 weeks. PW-TDI examinations were performed immediately before the induction and by the end of the experimental protocol. An increase in myocardial motion velocity was documented at the interventricular septum level, demonstrated by an elevation in systolic (Sa, and early (Ea and late (Aa diastolic waves (PA velocidade de movimentação miocárdica do ventrículo esquerdo foi quantificada por meio de exames ecocardiográficos com Doppler tecidual pulsado (PW-TDI em nove gatos adultos antes e após indução à tirotoxicose. Para indução da tirotoxicose, todos os gatos receberam doses diárias de 150mg kg-1 de levotiroxina sódica, por via oral, durante 10 semanas. Os exames de PW-TDI foram realizados imediatamente antes da indução e ao final do protocolo experimental. Uma elevação na velocidade de movimentação miocárdica foi documentada ao nível do septo interventricular, demonstrado por um aumento das ondas sistólica (Sa e diastólicas (Ea e Aa; P<0,05. No entanto, nenhuma alteração nos valores de Sa, Ea e Aa foi encontrada ao nível da parede livre do ventrículo esquerdo. A frequência cardíaca aumentou significativamente entre os momentos experimentais, sendo que três animais apresentaram fusão das ondas Aa e Ea ao final do experimento. O protocolo experimental utilizado neste estudo causou alterações na velocidade de movimentação do miocárdio ventricular esquerdo, mas sem causar danos à função diastólica do ventrículo esquerdo.

  15. Nonlinear Michelson interferometer for improved quantum metrology

    OpenAIRE

    Luis, Alfredo; Rivas, Ángel

    2015-01-01

    We examine quantum detection via a Michelson interferometer embedded in a gas with Kerr nonlinearity. This nonlinear interferometer is illuminated by pulses of classical light. This strategy combines the robustness against practical imperfections of classical light with the improvement provided by nonlinear processes. Regarding ultimate quantum limits, we stress that, as a difference with linear schemes, the nonlinearity introduces pulse duration as a new variable into play along with the ene...

  16. Experimental study on blood flow patterns through the phantoms of the intracranial arterial aneurysms using color Doppler imaging

    International Nuclear Information System (INIS)

    Chung, Tae Sub; Jeong, Eun Kee; Rhim, Yoon Chul; Kim, Sung Bin; Lee, Dong Hoon; Kim, Dae In

    1994-01-01

    The occurrence, growth, thrombosis, and rupture of intracranial saccular aneurysms can be directly related to the effect of hemodynamic forces. We developed the phantom flow models and compared with the computer simulation program to analyse the flow pattern and hemodynamics that might be responsible for the intracranial arterial aneurysms. We designed the arterial phantoms of three major sites of intracranial arterial aneurysm ; 1) basilar artery tip, 2) internal carotid artery bifurcation, 3) curved area of internal carotid artery. Flow patterns in the aneurysmal portion of phantoms were evaluated with color Doppler system on the connection with automatic closed type of circulation system. Then, we compared the results with computer simulation. The hemodynamic characteristics of the phantoms were identical with those obtained by computerisation's. Three distinct zones of flow were identified by color Doppler studies on the aneurysm of the curved area of an internal carotid artery : 1) an inflow zone entering the aneurysm at the distal aspect of its orifice, 2) an outflow zone exiting the aneurysm at the proximal aspect of its orifice, 3) a central slow vortex.However, the phantoms of basilar artery tip and artery bifurcation showed a direct inflow stream at the dome of an aneurysm. Flow dynamics in the various phantoms of the aneurysms can be successfully evaluated with color Doppler imaging, and were consistent with those predicted by computer simulations

  17. Clinical and Echocardiographic Evaluation of Regional Systolic Function Detected by Tissue Doppler Imaging in Hypertrophic Cardiomyopathy

    Directory of Open Access Journals (Sweden)

    A Sadeghpour

    2009-09-01

    Full Text Available Background: Hypertrophic cardiomyopathy (HCM is the most common type of the genetic cardiovasculardiseases. Regarding to tremendous heterogeneity in the phenotypic expression of HCM, which is generally unrelatedto genotype, we aimed to study, clinical and echocardiographic parameters such as Tissue Doppler Imaging(TDI in various subtypes of HCM patients and evaluate the influence of race and gender in Iranian patients.Methods: Patients with HCM underwent a complete clinical and echocardiographic study including TDI toassess regional systolic contraction( in the 12 segments and early diastolic annular velocity (Em from theseptal mitral annulus.Results: The study comprised 41 patients (20 women, mean age = 41 ± 15 years with mean LVEF 55%±4.8%and mean maximal septal thickness 2.07cm. Considering LVOT gradient>30mmHg, hypertrophic obstructivecardiomyopathy (HOCM was found in 18 (45%. Asymmetric septal hypertrophy (ASH existed in 27 patients(67%, systolic anterior motion of anterior mitral leaflet (SAM in 25 persons (64%. Nineteen patients (46.3%were included in NYHA function class (FC II and 6 (14.7% in FC III or higher. We found syncope in 10(24.4%, chest pain in 4 (9.8%, atrial fibrilation in 14.6 % and ventricular arrhythmias in (17.1% of patients.History of ICD was seen in 7 (17.1% and PPM in 9 cases. Mean E’ velocity was 5.44± 1.65 cm/sec and S velocity5.70± 1.49 cm/sec with significant lower S velocity and E’ in syncope patients. Overall, HOCM patients hadgrade II diastolic dysfunction with E/É >15(17.54±7.46. Majority (25 of cases (61% were categorized in typeIII of HCM. RV involvement was observed in 11 patients (28.2%.No significant differences existed betweenprevalence of syncope and dysrhythmia among HCM and HOCM patients.Conclusion: In our study, we found lower detection of latent HOCM, compared to other studies, suggestive ofinadequate use of appropriate provocative maneuvers such as exercise stress echocardiography and amyl

  18. The application of color Doppler flow imaging in the diagnosis and therapeutic effect evaluation of erectile dysfunction

    Directory of Open Access Journals (Sweden)

    Xu-Jun Xuan

    2016-01-01

    Full Text Available We aim to investigate the correlations between hemodynamic parameters, penile rigidity grading, and the therapeutic effects of phosphodiesterase type 5 inhibitors using color Doppler flow imaging after intracavernosal injection in patients with erectile dysfunction. This study involved 164 patients. After intracavernosal injection with a mixture of papaverine (60 mg, prostaglandin E 1 (10 mg, and lidocaine (2%, 0.5-1 ml, the penile vessels were assessed using color Doppler flow imaging. Penile rigidity was classified based on the Erection Hardness Score system as Grades 4, 3, 2 or 1 (corresponding to Schramek Grades V to II. Then, the patients were given oral sildenafil (50-100 mg and scored according to the International Index of Erectile Function (IIEF-5 questionnaire. The number of patients with penile rigidities of Schramek Grades II to V was 14, 18, 21, and 111, respectively. The IIEF-5 score was positively correlated with the refilling index of the penile cavernosal artery (r = 0.79, P< 0.05, the peak systolic velocity (r = 0.45, P< 0.05, and penile rigidity (r = 0.75, P< 0.05, and was negatively correlated with the end diastolic velocity (r = −0.74, P< 0.05. For patients with erectile dysfunction, both the IIEF-5 score after sildenafil administration, which is correlated with penile rigidity, and the hemodynamic parameters detected using color Doppler flow imaging may predict the effects of phosphodiesterase type 5 inhibitor treatment and could provide a reasonable model for the targeted-treatment of erectile dysfunction.

  19. Assessment of regional systolic and diastolic myocardial function using tissue Doppler and strain imaging in dogs with dilated cardiomyopathy.

    Science.gov (United States)

    Chetboul, Valérie; Gouni, Vassiliki; Sampedrano, Carolina Carlos; Tissier, Renaud; Serres, François; Pouchelon, Jean-Louis

    2007-01-01

    Tissue Doppler Imaging (TDI) or strain (St) imaging could provide sensitive indices for early detection and treatment follow-up of canine dilated cardiomyopathy (DCM). Analysis of TDI and St features in dogs with overt DCM is a prerequisite before using these new criteria in prospective screenings of predisposed families or in clinical trials. Radial and longitudinal right and left myocardial motion, assessed by TDI and St variables, is altered in dogs with DCM. Case records for 26 dogs; 14 with DCM and 12 healthy controls of comparable age and weight were reviewed. A retrospective analysis was conducted of conventional echocardiography, 2-dimensional color TDI, and St imaging data. The DCM group was characterized by decreases in radial and longitudinal systolic velocity gradients of the left ventricular free wall (LVFW), radial and longitudinal absolute values of peak systolic St of the LVFW, and longitudinal systolic right ventricular (RV) velocities (all P canine DCM.

  20. Power Doppler Ultrasonography and Shear Wave Elastography as Complementary Imaging Methods for Suspected Local Breast Cancer Recurrence.

    Science.gov (United States)

    Jales, Rodrigo Menezes; Dória, Maira Teixeira; Serra, Kátia Piton; Miranda, Mila Meneguelli; Menossi, Carlos Alberto; Schumacher, Klaus; Sarian, Luis Otávio

    2018-06-01

    To prospectively investigate the diagnostic accuracy and clinical consequences of power Doppler morphologic criteria and shear wave elastography (SWE) as complementary imaging methods for evaluation of suspected local breast cancer recurrence in the ipsilateral breast or chest wall. Thirty-two breast masses with a suspicion of local breast cancer recurrence on B-mode ultrasonography underwent complementary power Doppler and SWE evaluations. Power Doppler morphologic criteria were classified as avascular, hypovascular, or hypervascular. Shear wave elastography was classified according to a 5-point scale (SWE score) and SWE maximum elasticity. Diagnostic accuracy was assessed by the sensitivity, specificity, and area under the curve. A decision curve analysis assessed clinical consequences of each method. The reference standard for diagnosis was defined as core needle or excisional biopsy. Histopathologic examinations revealed 9 (28.2%) benign and 23 (71.8%) malignant cases. Power Doppler ultrasonography (US) had sensitivity of 34.8% (95% confidence interval [CI], 6.6%-62.9%) and specificity of 45.4% (95% CI, 19.3%-71.5%). The SWE score (≥3) had sensitivity of 87.0% (95% CI, 66.4%-97.2%) and specificity of 44.4% (95% CI, 13.7%-78.8%). The SWE maximum elasticity (velocity > 6.5cm/s) had sensitivity of 87% (95% CI, 66.4%-97.2%) and specificity of 77.8% (95% CI, 40.0% to 97.2%). The areas under the curves for the SWE score and SWE maximum elasticity were 0.71 (95% CI, 0.53-0.87) and 0.82 (95% CI, 0.64-0.93), respectively (P = .32). Power Doppler US is unsuitable for discrimination between local breast cancer recurrence and fibrosis. Although the SWE score and SWE maximum elasticity can make this discrimination, the use of these methods to determine biopsy may lead to poorer clinical outcomes than the current practice of performing biopsies of all suspicious masses. © 2017 by the American Institute of Ultrasound in Medicine.

  1. Computerized evaluation optical measuring thin films by the help of Michelson`s interferometer

    Czech Academy of Sciences Publication Activity Database

    Bartoněk, L.; Keprt, Jiří

    2002-01-01

    Roč. 9, č. 2 (2002), s. 27-34 ISSN 1335-0803 R&D Projects: GA MŠk LN00A015 Institutional research plan: CEZ:AV0Z1010921 Keywords : Michelson `s interferometer * computerized evaluation Subject RIV: BH - Optics, Masers, Lasers

  2. Color doppler flow imaging in evaluation of uterine arterial embolization of leiomyoma with KMG

    International Nuclear Information System (INIS)

    Li Furong; Guo Yunhuai; Liu Lifang; Liu Jianhua; Guo Yunhuai

    2006-01-01

    Objective: To explore the effectiveness of a new kind of embolization agent-sodium alginate(KMG), and to evaluate the clinical value of 2D color Doppler ultrasound in assessing the therapeutic effect of uterine arterial embolization (UAE) in leiomyomas. Methods: Forty nine patients with symptomatic leiomyomas were undertaken UAE with KMG for the treatment. Sonography was performed at 3-7 days before and, 1, 3, 6 months after UAE with 2D color Doppler for evaluating the 2D echograms and hemodynamics. Results: Forty nine leiomyomas were studied after UAE, showing a marked reduction in the size (35%-90%). No blood flow was demonstrated in the leiomyomas either 3-7 days or 1 month or 3 months after the procedure. The reappearance of blood flow could be seen in only one case. Conclusion: KMG is an efficient embolization agent for the treatment of symptomatic leiomyomas with UAE, and ultrasonography is a useful tool to assess the effectiveness. (authors)

  3. [Vascular complications following kidney transplant: the role of color-Doppler imaging].

    Science.gov (United States)

    Granata, Antonio; Floccari, Fulvio; Lentini, Paolo; Vittoria, Salvatore; Di Pietro, Fabio; Zamboli, Pasquale; Fiorini, Fulvio; Fatuzzo, Pasquale

    2012-01-01

    The progressive decline in the incidence of graft rejection has made urological, surgical, parenchymal and vascular complications of kidney transplant more frequent. The latter, although accounting for only 5-10% of all post-transplant complications, are a frequent cause of graft loss. Ultrasonography, both in B-mode and with Doppler ultrasound, is an important diagnostic tool in case of clinical conditions which might impair kidney function. Even though ultrasonography is considered fundamental in the diagnosis of parenchymal and surgical complications of the transplanted kidney, its role is not fully understood in case of vascular complications of the graft. The specificity of Doppler ultrasound is very important in case of stenosis of the transplanted renal artery, pseudoaneurysms, arteriovenous fistulas, and thrombosis with complete or partial artery or vein occlusion. Doppler and color determinations present high diagnostic accuracy, which is higher in case of successive measurements performed during the follow-up of the graft. Modern techniques including contrast-enhanced ultrasound increase the diagnostic power of ultrasonography in case of vascular complications of the transplanted kidney, planted kidney.

  4. Multiple reflection Michelson interferometer with picometer resolution.

    Science.gov (United States)

    Pisani, Marco

    2008-12-22

    A Michelson interferometer based on an optical set-up allowing multiple reflection between two plane mirrors performs the multiplication of the optical path by a factor N, proportionally increasing the resolution of the measurement. A multiplication factor of almost two orders of magnitude has been demonstrated with a simple set-up. The technique can be applied to any interferometric measurement where the classical interferometer limits due to fringe nonlinearities and quantum noise are an issue. Applications in precision engineering, vibration analysis, nanometrology, and spectroscopy are foreseen.

  5. Using Flow Characteristics in Three-Dimensional Power Doppler Ultrasound Imaging to Predict Complete Responses in Patients Undergoing Neoadjuvant Chemotherapy.

    Science.gov (United States)

    Shia, Wei-Chung; Huang, Yu-Len; Wu, Hwa-Koon; Chen, Dar-Ren

    2017-05-01

    Strategies are needed for the identification of a poor response to treatment and determination of appropriate chemotherapy strategies for patients in the early stages of neoadjuvant chemotherapy for breast cancer. We hypothesize that power Doppler ultrasound imaging can provide useful information on predicting response to neoadjuvant chemotherapy. The solid directional flow of vessels in breast tumors was used as a marker of pathologic complete responses (pCR) in patients undergoing neoadjuvant chemotherapy. Thirty-one breast cancer patients who received neoadjuvant chemotherapy and had tumors of 2 to 5 cm were recruited. Three-dimensional power Doppler ultrasound with high-definition flow imaging technology was used to acquire the indices of tumor blood flow/volume, and the chemotherapy response prediction was established, followed by support vector machine classification. The accuracy of pCR prediction before the first chemotherapy treatment was 83.87% (area under the ROC curve [AUC] = 0.6957). After the second chemotherapy treatment, the accuracy of was 87.9% (AUC = 0.756). Trend analysis showed that good and poor responders exhibited different trends in vascular flow during chemotherapy. This preliminary study demonstrates the feasibility of using the vascular flow in breast tumors to predict chemotherapeutic efficacy. © 2017 by the American Institute of Ultrasound in Medicine.

  6. On the importance of the Michelson-Morley experiment

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1992-01-01

    The opinion of an important role of the Michelson-Morley experiment in the establishment of the pronciple oof the light velocity constancy is expressed. It is stressed that the used of radar length for the treatment of the Michelson-Morley experiment leads to the elongation formulas for the longitudinal arm of an interferometer. 24 refs

  7. Michelson interferometer based interleaver design using classic IIR filter decomposition.

    Science.gov (United States)

    Cheng, Chi-Hao; Tang, Shasha

    2013-12-16

    An elegant method to design a Michelson interferometer based interleaver using a classic infinite impulse response (IIR) filter such as Butterworth, Chebyshev, and elliptic filters as a starting point are presented. The proposed design method allows engineers to design a Michelson interferometer based interleaver from specifications seamlessly. Simulation results are presented to demonstrate the validity of the proposed design method.

  8. Quantification of colour Doppler activity in the wrist in patients with rheumatoid arthritis - the reliability of different methods for image selection and evaluation

    DEFF Research Database (Denmark)

    Ellegaard, K.; Torp-Pedersen, S.; Lund, H.

    2008-01-01

    measurements in the wrist of patients with rheumatoid arthritis (RA) using different selection and quantification methods. Materials and Methods: 14 patients with RA had their wrist scanned twice by the same investigator with an interval of 30 Minutes, The images for analysis were selected either......Purpose: The amount Of colour Doppler activity in the inflamed synovium is used to quantity inflammatory activity. The measurements may vary due to image selection, quantification method, and point in cardiac cycle. This study investigated the test-retest reliability Of ultrasound colour Doppler...... was obtained when the images were selected guided by colour Doppler and the Subsequent quantification was (done in an area defined by anatomical Structures. With this method, the intra-class coefficient ICC (2.1) was 0.95 and the within-subject SD (SW) was 0.017, indicating good reliability. In contrast, poor...

  9. A review of suspension-Scattered particles used in blood-mimicking fluid for doppler ultrasound imaging

    Directory of Open Access Journals (Sweden)

    Ammar A Oglat

    2018-01-01

    Full Text Available Doppler ultrasound imaging system description and calibration need blood-mimicking fluids (BMFs for the test target of medical ultrasound diagnostic tools, with known interior features and acoustic and physical properties of this fluid (BMF. Physical and acoustical properties determined in the International Electrotechnical Commission (IEC standard are specified as constant values, the materials used in the BMF preparation should have values similar to the IEC standard values. However, BMF is ready-made commercially from a field of medical usage, which may not be appropriate in the layout of ultrasound system or for an estimate of novel imaging mechanism. It is often eligible to have the capability to make sound properties and mimic blood arrangement for specific applications. In this review, sufficient BMF materials, liquids, and measures are described which have been generated by utilizing diverse operation mechanism and materials that have sculptured a range of biological systems.

  10. An X-ray BBB Michelson interferometer.

    Science.gov (United States)

    Sutter, John P; Ishikawa, Tetsuya; Kuetgens, Ulrich; Materlik, Gerhard; Nishino, Yoshinori; Rostomyan, Armen; Tamasaku, Kenji; Yabashi, Makina

    2004-09-01

    A new X-ray Michelson interferometer based on the BBB interferometer of Bonse and Hart and designed for X-rays of wavelength approximately 1 A was described in a previous paper. Here, a further test carried out at the SPring-8 1 km beamline BL29XUL is reported. One of the BBB's mirrors was displaced by a piezo to introduce the required path-length difference. The resulting variation of intensity with piezo voltage as measured by an avalanche photodiode could be ascribed to the phase variation resulting from the path-length change, with a small additional contribution from the change of the position of the lattice planes of the front mirror relative to the rest of the crystal. This 'Michelson fringe' interpretation is supported by the observed steady movement across the output beam of the interference fringes produced by a refractive wedge when the piezo voltage was ramped. The front-mirror displacement required for one complete fringe at the given wavelength is only 0.675 A; therefore, a quiet environment is vital for operating this device, as previous experiments have shown.

  11. Optical path difference measurements with a two-step parallel phase shifting interferometer based on a modified Michelson configuration

    Science.gov (United States)

    Toto-Arellano, Noel Ivan; Serrano-Garcia, David I.; Rodriguez-Zurita, Gustavo

    2017-09-01

    We report an optical implementation of a parallel phase-shifting quasi-common path interferometer using two modified Michelson interferometers to generate two interferograms. By using a displaceable polarizer's array, placed on the image plane, we can obtain four phase-shifted interferograms in two captures. The system operates as a quasi-common path interferometer generating four beams, which are to interfere with alignment procedures on the mirrors of the Michelson configurations. The optical phase data are retrieved using the well-known four-step algorithms. To present the capabilities of the system, experimental results obtained from transparent structures are presented.

  12. Concurrent Reflectance Confocal Microscopy and Laser Doppler Flowmetry to Improve Skin Cancer Imaging: A Monte Carlo Model and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Alireza Mowla

    2016-09-01

    Full Text Available Optical interrogation of suspicious skin lesions is standard care in the management of skin cancer worldwide. Morphological and functional markers of malignancy are often combined to improve expert human diagnostic power. We propose the evaluation of the combination of two independent optical biomarkers of skin tumours concurrently. The morphological modality of reflectance confocal microscopy (RCM is combined with the functional modality of laser Doppler flowmetry, which is capable of quantifying tissue perfusion. To realize the idea, we propose laser feedback interferometry as an implementation of RCM, which is able to detect the Doppler signal in addition to the confocal reflectance signal. Based on the proposed technique, we study numerical models of skin tissue incorporating two optical biomarkers of malignancy: (i abnormal red blood cell velocities and concentrations and (ii anomalous optical properties manifested through tissue confocal reflectance, using Monte Carlo simulation. We also conduct a laboratory experiment on a microfluidic channel containing a dynamic turbid medium, to validate the efficacy of the technique. We quantify the performance of the technique by examining a signal to background ratio (SBR in both the numerical and experimental models, and it is shown that both simulated and experimental SBRs improve consistently using this technique. This work indicates the feasibility of an optical instrument, which may have a role in enhanced imaging of skin malignancies.

  13. [Parenchymal complications of the transplanted kidney: the role of color-Doppler imaging].

    Science.gov (United States)

    Granata, Antonio; Clementi, Silvia; Clementi, Anna; Di Pietro, Fabio; Scarfia, Viviana R; Insalaco, Monica; Aucella, Filippo; Prencipe, Michele; Fiorini, Fulvio; Sicurezza, Elvia

    2012-01-01

    Kidney transplantation is the treatment of choice for end-stage renal disease, given the better quality of life of transplanted patients when compared to patients on maintenance dialysis. In spite of surgical improvements and new immunosuppressive regimens, part of the transplanted grafts still develop chronic dysfunction. Ultrasonography, both in B-mode and with Doppler ultrasound, is an important diagnostic tool in case of clinical conditions which might impair kidney function. Even though ultrasonography is considered fundamental in the diagnosis of vascular and surgical complications of the transplanted kidney, its role is not fully understood in case of parenchymal complications of the graft. The specificity of Doppler ultrasound is low both in case of acute complications such as acute tubular necrosis, drug toxicity and acute rejection, and in case of chronic conditions such as chronic allograft nephropathy. Single determinations of resistance indices present low diagnostic accuracy, which is higher in case of successive measurements performed during the follow-up of the graft. Modern techniques including tissue pulsatility index, maximal fractional area and contrast-enhanced ultrasound increase the diagnostic power of ultrasonography in case of parenchymal complications of the transplanted kidney.

  14. Steerable Doppler transducer probes

    International Nuclear Information System (INIS)

    Fidel, H.F.; Greenwood, D.L.

    1986-01-01

    An ultrasonic diagnostic probe is described which is capable of performing ultrasonic imaging and Doppler measurement consisting of: a hollow case having an acoustic window which passes ultrasonic energy and including chamber means for containing fluid located within the hollow case and adjacent to a portion of the acoustic window; imaging transducer means, located in the hollow case and outside the fluid chamber means, and oriented to direct ultrasonic energy through the acoustic window toward an area which is to be imaged; Doppler transducer means, located in the hollow case within the fluid chamber means, and movably oriented to direct Doppler signals through the acoustic window toward the imaged area; means located within the fluid chamber means and externally controlled for controllably moving the Doppler transducer means to select one of a plurality of axes in the imaged area along which the Doppler signals are to be directed; and means, located external to the fluid chamber means and responsive to the means for moving, for providing an indication signal for identifying the selected axis

  15. Automated flow quantification in valvular heart disease based on backscattered Doppler power analysis: implementation on matrix-array ultrasound imaging systems.

    Science.gov (United States)

    Buck, Thomas; Hwang, Shawn M; Plicht, Björn; Mucci, Ronald A; Hunold, Peter; Erbel, Raimund; Levine, Robert A

    2008-06-01

    Cardiac ultrasound imaging systems are limited in the noninvasive quantification of valvular regurgitation due to indirect measurements and inaccurate hemodynamic assumptions. We recently demonstrated that the principle of integration of backscattered acoustic Doppler power times velocity can be used for flow quantification in valvular regurgitation directly at the vena contracta of a regurgitant flow jet. We now aimed to accomplish implementation of automated Doppler power flow analysis software on a standard cardiac ultrasound system utilizing novel matrix-array transducer technology with detailed description of system requirements, components and software contributing to the system. This system based on a 3.5 MHz, matrix-array cardiac ultrasound scanner (Sonos 5500, Philips Medical Systems) was validated by means of comprehensive experimental signal generator trials, in vitro flow phantom trials and in vivo testing in 48 patients with mitral regurgitation of different severity and etiology using magnetic resonance imaging (MRI) for reference. All measurements displayed good correlation to the reference values, indicating successful implementation of automated Doppler power flow analysis on a matrix-array ultrasound imaging system. Systematic underestimation of effective regurgitant orifice areas >0.65 cm(2) and volumes >40 ml was found due to currently limited Doppler beam width that could be readily overcome by the use of new generation 2D matrix-array technology. Automated flow quantification in valvular heart disease based on backscattered Doppler power can be fully implemented on board a routinely used matrix-array ultrasound imaging systems. Such automated Doppler power flow analysis of valvular regurgitant flow directly, noninvasively, and user independent overcomes the practical limitations of current techniques.

  16. Developments in target micro-Doppler signatures analysis: radar imaging, ultrasound and through-the-wall radar

    OpenAIRE

    Clemente, C.; Balleri, A.; Woodbridge, K.; Soraghan, J. J.

    2013-01-01

    Target motions, other than the main bulk translation of the target, induce Doppler modulations around the main Doppler shift that form what is commonly called a target micro-Doppler signature. Radar micro-Doppler signatures are generally both target and action speci c and hence can be used to classify and recognise targets as well as to identify possible threats. In recent years, research into the use of micro-Doppler signatures for target classi cation to address many defence and security ch...

  17. Color Doppler imaging of the retrobulbar circulation in progressive glaucoma optic neuropathy.

    Science.gov (United States)

    Magureanu, Marineta; Stanila, Adriana; Bunescu, Liviu Valentin; Armeanu, Cristina

    2016-01-01

    It is known that elevated intraocular pressure (IOP) is the primary risk factor for glaucoma. Recently, more and more evidences have shown that the vascular deficit also plays an important role in the pathogenesis and progressions of glaucomatous optic neuropathy. This issue is backed up by glaucomatous optic neuropathy (GON) cases drug compensated in which the progression of the disease in one or both eyes is ascertained despite a normal and relatively constant IOP. The present study evaluated the hemodynamic parameters in the retrobulbar circulation in patients with progressive glaucomatous optic neuropathy in one eye, who received compensated medication. The hemodynamic parameters (PSV, EDV, IR) were measured by using color Doppler ultrasound and progression was evaluated by a repeated automated perimetry. The obtained values were statistically analyzed and compared with those obtained for the stable eye.

  18. Calibrating Doppler imaging of preterm intracerebral circulation using a microvessel flow phantom

    Directory of Open Access Journals (Sweden)

    Fleur A. Camfferman

    2015-01-01

    Full Text Available Introduction. Preterm infants are born during critical stages of brain development, in which the adaptive capacity of the fetus to extra-uterine environment is limited. Inadequate brain perfusion has been directly linked to preterm brain damage. Advanced high-frequency ultrasound probes and processing algorithms allow visualization of microvessels and depiction of regional variation. To assess whether visualization and flow velocity estimates of preterm cerebral perfusion using Doppler techniques is accurate, we conducted an in vitro experiment using a microvessel flow phantom.Materials and Methods. An in-house developed flow phantom containing two microvessels (inner diameter 200 and 700 microns with attached syringe pumps, filled with blood-mimicking fluid, was used to generate non-pulsatile perfusion of variable flow. Measurements were performed using an Esaote MyLab70 scanner.Results. Microvessel mimicking catheters with velocities as low as 1cm/sec were adequately visualized with a linear ultrasound probe. With a convex probe velocities <2 cm/sec could not be depicted. Within settings, velocity and diameter measurements were highly reproducible (intra class correlation 0.997 (95% CI 0.996-0.998 and 0.914 (0.864-0.946. Overall, mean velocity was overestimated up to 3-fold, especially in high velocity ranges. Significant differences were seen in velocity measurements when using steer angle correction and in vessel diameter estimation (p<0.05.Conclusion. Visualization of microvessel size catheters mimicking small brain vessels is feasible. Reproducible velocity and diameter results can be obtained, although important overestimation of the values is observed. Before velocity estimates of microcirculation can find its use in clinical practice, calibration of the ultrasound machine for any specific Doppler purpose is essential. The ultimate goal is to develop a sonographic tool that can be used for objective study of regional perfusion in routine

  19. Distributed acoustic sensing with Michelson interferometer demodulation

    Science.gov (United States)

    Liu, Xiaohui; Wang, Chen; Shang, Ying; Wang, Chang; Zhao, Wenan; Peng, Gangding; Wang, Hongzhong

    2017-09-01

    The distributed acoustic sensing (DAS) has been extensively studied and widely used. A distributed acoustic sensing system based on the unbalanced Michelson interferometer with phase generated carrier (PGC) demodulation was designed and tested. The system could directly obtain the phase, amplitude, frequency response, and location information of sound wave at the same time and measurement at all points along the sensing fiber simultaneously. Experiments showed that the system successfully measured the acoustic signals with a phase-pressure sensitivity about-148 dB (re rad/μPa) and frequency response ripple less than 1.5 dB. The further field experiment showed that the system could measure signals at all points along the sensing fiber simultaneously.

  20. Naturally stable Sagnac-Michelson nonlinear interferometer.

    Science.gov (United States)

    Lukens, Joseph M; Peters, Nicholas A; Pooser, Raphael C

    2016-12-01

    Interferometers measure a wide variety of dynamic processes by converting a phase change into an intensity change. Nonlinear interferometers, making use of nonlinear media in lieu of beamsplitters, promise substantial improvement in the quest to reach the ultimate sensitivity limits. Here we demonstrate a new nonlinear interferometer utilizing a single parametric amplifier for mode mixing-conceptually, a nonlinear version of the conventional Michelson interferometer with its arms collapsed together. We observe up to 99.9% interference visibility and find evidence for noise reduction based on phase-sensitive gain. Our configuration utilizes fewer components than previous demonstrations and requires no active stabilization, offering new capabilities for practical nonlinear interferometric-based sensors.

  1. Spectral pulsed-wave tissue Doppler imaging lateral-to-septal delay fails to predict clinical or echocardiographic outcome after cardiac resynchronization therapy

    NARCIS (Netherlands)

    O.I.I. Soliman (Osama Ibrahim Ibrahim); D.A.M.J. Theuns (Dominic); M.L. Geleijnse (Marcel); A. Nemes (Attila); K. Caliskan (Kadir); W.B. Vletter (Wim); L.J.L.M. Jordaens (Luc); F.J. ten Cate (Folkert)

    2007-01-01

    textabstractAims: The current study sought to assess if pre-implantation lateral-to-septal delay (LSD) ≥60 ms assessed by spectral pulsed-wave myocardial tissue Doppler imaging (PW-TDI) could predict successful long-term outcome after cardiac resynchronization therapy (CRT). Methods and results

  2. The Doppler effect and the three most famous experiments for special relativity

    Science.gov (United States)

    Klinaku, Shukri

    Using the general formula for the Doppler effect at any arbitrary angle, the three famous experiments for special theory of relativity will be examined. Explanation of the experiments of Michelson, Kennedy-Thorndike and Ives-Stilwell will be given in a precise and elegant way without postulates, arbitrary assumptions or approximations.

  3. Prediction of adverse pregnancy outcomes using uterine artery Doppler imaging at 22-24 weeks of pregnancy: A North Indian experience

    Directory of Open Access Journals (Sweden)

    Deepti Verma

    2016-06-01

    Full Text Available Objective: The aim of this study was to assess the predictive value of uterine artery Doppler imaging at 22-24 weeks of gestation for adverse pregnancy outcomes. Materials and Methods: This was a prospective study in which uterine artery Doppler was performed at 22-24 weeks of gestation in 165 pregnant women with singleton pregnancies. A pulsatility index (PI more than 1.45 or bilateral uterine notching was labeled as abnormal Doppler. The pregnancy outcome was assessed in terms of normal outcome, preeclampsia, fetal growth restriction (FGR, low birth weight, spontaneous preterm delivery, oligohydramnios, fetal loss or at least one adverse outcome. Results: Out of 165 patients, 35 (21.2% had abnormal second trimester uterine artery Doppler. In pregnancies that resulted in preeclampsia (PE, (n=21, FGR, (n=21, and low birth weight (n=39, the median uterine artery PI was higher (1.52, 1.41, and 1.27 respectively. In the presence of abnormal Doppler, the risk of PE [OR=10.7, 95% confidence interval (CI: (3.91-29.1; p<0.001], FGR [OR=4.34, 95% CI: (1.62-11.6; p=0.002], low birth weight [OR=6.39, 95% CI: (3.16-12.9; p<0.001] and the risk of at least one obstetric complication [OR=8.73, 95% CI: (3.5-21.3; p<0.001] was significantly high. The positive predictive value of abnormal uterine artery Doppler was highest for preeclampsia (36.84% among all adverse pregnancy outcomes assessed. Conclusion: Uterine artery Doppler ultrasonography at 22-24 weeks of gestation is a significant predictor of at least one adverse pregnancy outcome, with the highest prediction for preeclampsia.

  4. Plasma flow velocity measurements using a modulated Michelson interferometer

    International Nuclear Information System (INIS)

    Howard, J.

    1997-01-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (orig.)

  5. Special topics in infrared interferometry. [Michelson interferometer development

    Science.gov (United States)

    Hanel, R. A.

    1985-01-01

    Topics in IR interferometry related to the development of a Michelson interferometer are treated. The selection and reading of the signal from the detector to the analog to digital converter is explained. The requirements for the Michelson interferometer advance speed are deduced. The effects of intensity modulation on the interferogram are discussed. Wavelength and intensity calibration of the interferometer are explained. Noise sources (Nyquist or Johnson noise, phonon noise), definitions of measuring methods of noise, and noise measurements are presented.

  6. Fetal cardiac stroke volume determination by four-dimensional ultrasound with spatio-temporal image correlation compared with two-dimensional and Doppler ultrasonography.

    Science.gov (United States)

    Rizzo, Giuseppe; Capponi, Alessandra; Cavicchioni, Ottavia; Vendola, Marianne; Arduini, Domenico

    2007-12-01

    To assess the agreement of stroke volume (SV) measured with two-dimensional (2D) ultrasonography with Doppler capability (vs) four-dimensional (4D) with spatiotemporal image correlation (STIC) in normal and growth restricted fetuses. 2D Doppler and 4D STIC were used to measure SV of 40 normal fetuses at 20 to 22 and 28 to 32 weeks, and 16 growth-restricted fetuses at 26 to 34 weeks of gestation. Intraclass correlation was used to evaluate the agreement between left and right SV obtained by the two techniques, and proportionate Bland-Altman plots constructed. The time necessary to obtain SV was analyzed. The intraclass correlation coefficient between 2D Doppler and 4D STIC measurements for the left ventricle were 0.977 and 0.980 for the right ventricle. The proportionate limits of agreement between the two methods were 18.7 to 23.9% for the left ventricle and - 20.9 to 21.7% for the right ventricle. The time necessary to measure SV was significantly shorter with 4D STIC (3.1 (vs) 7.9 min p < 0.0001) than with 2D Doppler. There is a good agreement between SV measured either by 2D Doppler or by 4D STIC. The 4D STIC represents a simple and rapid technique to estimate fetal SV and promises to become the method of choice. Copyright (c) 2007 John Wiley & Sons, Ltd.

  7. Model experiments on imaging subsurface fracture permeability by pulsed Doppler borehole televiewer; Pulse doppler borehole televiewer ni yoru kiretsu tosuisei hyoka ni kansuru model jikken

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, Y; Niitsuma, H [Tohoku University, Sendai (Japan). Faculty of Engineering

    1996-05-01

    This paper reports model experiments to evaluate flow rates of fluids passing through a fracture by using a Doppler borehole televiewer (DBHTV). A supersonic transducer disposed on a well axis transmits transmission pulses, and a transducer receives scattered waves generated by particulates in water and waves reflected on a well wall. This signal is applied with time gating to extract only the scattered waves from particulates in the vicinity of the well wall. Deriving spectra in the recorded Doppler signal obtains flow velocity components in the direction of the well radius. A model was made with a polyvinylchloride pipe with a diameter of 14.6 cm to simulate a well, to which an aluminum pipe with an inner diameter of 2 mm is connected to be used as a simulated fracture, and mud water is circulated in the pipe. The result of deriving a passed flow volume in this model by integrating flow rate distribution derived by using the above method to a predetermined range in the vicinity of the fracture showed a good proportional relationship with actual flow rate in the simulated fracture. 1 ref., 7 figs.

  8. Automated assessment of joint synovitis activity from medical ultrasound and power doppler examinations using image processing and machine learning methods

    Directory of Open Access Journals (Sweden)

    Rafal Cupek

    2016-11-01

    Full Text Available Objectives : Rheumatoid arthritis is the most common rheumatic disease with arthritis, and causes substantial functional disability in approximately 50% patients after 10 years. Accurate measurement of the disease activity is crucial to provide an adequate treatment and care to the patients. The aim of this study is focused on a computer aided diagnostic system that supports an assessment of synovitis severity. Material and methods : This paper focus on a computer aided diagnostic system that was developed within joint Polish–Norwegian research project related to the automated assessment of the severity of synovitis. Semiquantitative ultrasound with power Doppler is a reliable and widely used method of assessing synovitis. Synovitis is estimated by ultrasound examiner using the scoring system graded from 0 to 3. Activity score is estimated on the basis of the examiner’s experience or standardized ultrasound atlases. The method needs trained medical personnel and the result can be affected by a human error. Results : The porotype of a computer-aided diagnostic system and algorithms essential for an analysis of ultrasonic images of finger joints are main scientific output of the MEDUSA project. Medusa Evaluation System prototype uses bone, skin, joint and synovitis area detectors for mutual structural model based evaluation of synovitis. Finally, several algorithms that support the semi-automatic or automatic detection of the bone region were prepared as well as a system that uses the statistical data processing approach in order to automatically localize the regions of interest. Conclusions : Semiquantitative ultrasound with power Doppler is a reliable and widely used method of assessing synovitis. Activity score is estimated on the basis of the examiner’s experience and the result can be affected by a human error. In this paper we presented the MEDUSA project which is focused on a computer aided diagnostic system that supports an

  9. What's behind the mask? A look at blood flow changes with prolonged facial pressure and expression using laser Doppler imaging.

    Science.gov (United States)

    Van-Buendia, Lan B; Allely, Rebekah R; Lassiter, Ronald; Weinand, Christian; Jordan, Marion H; Jeng, James C

    2010-01-01

    Clinically, the initial blanching in burn scar seen on transparent plastic face mask application seems to diminish with time and movement requiring mask alteration. To date, studies quantifying perfusion with prolonged mask use do not exist. This study used laser Doppler imaging (LDI) to assess perfusion through the transparent face mask and movement in subjects with and without burn over time. Five subjects fitted with transparent face masks were scanned with the LDI on four occasions. The four subjects without burn were scanned in the following manner: 1) no mask, 2) mask on while at rest, 3) mask on with alternating intervals of sustained facial expression and rest, and 4) after mask removal. Images were acquired every 3 minutes throughout the 85-minute study period. The subject with burn underwent a shortened scanning protocol to increase comfort. Each face was divided into five regions of interest for analysis. Compared with baseline, mask application decreased perfusion significantly in all subjects (P mask removal, all regions of the face demonstrated a hyperemic effect with the chin (P = .05) and each cheek (P mask removal. Perfusions remain constantly low while wearing the face mask, despite changing facial expressions. Changing facial expressions with the mask on did not alter perfusion. Hyperemic response occurs on removal of the mask. This study exposed methodology and statistical issues worth considering when conducting future research with the face, pressure therapy, and with LDI technology.

  10. Images of gravitational and magnetic phenomena derived from two-dimensional back-projection Doppler tomography of interacting binary stars

    International Nuclear Information System (INIS)

    Richards, Mercedes T.; Cocking, Alexander S.; Fisher, John G.; Conover, Marshall J.

    2014-01-01

    We have used two-dimensional back-projection Doppler tomography as a tool to examine the influence of gravitational and magnetic phenomena in interacting binaries that undergo mass transfer from a magnetically active star onto a non-magnetic main-sequence star. This multitiered study of over 1300 time-resolved spectra of 13 Algol binaries involved calculations of the predicted dynamical behavior of the gravitational flow and the dynamics at the impact site, analysis of the velocity images constructed from tomography, and the influence on the tomograms of orbital inclination, systemic velocity, orbital coverage, and shadowing. The Hα tomograms revealed eight sources: chromospheric emission, a gas stream along the gravitational trajectory, a star-stream impact region, a bulge of absorption or emission around the mass-gaining star, a Keplerian accretion disk, an absorption zone associated with hotter gas, a disk-stream impact region, and a hot spot where the stream strikes the edge of a disk. We described several methods used to extract the physical properties of the emission sources directly from the velocity images, including S-wave analysis, the creation of simulated velocity tomograms from hydrodynamic simulations, and the use of synthetic spectra with tomography to sequentially extract the separate sources of emission from the velocity image. In summary, the tomography images have revealed results that cannot be explained solely by gravitational effects: chromospheric emission moving with the mass-losing star, a gas stream deflected from the gravitational trajectory, and alternating behavior between stream state and disk state. Our results demonstrate that magnetic effects cannot be ignored in these interacting binaries.

  11. Detection of Breast Microcalcifications Under Ultrasound Using Power Doppler and Acoustic Resonance Imaging

    National Research Council Canada - National Science Library

    Weinstein, Susan

    2003-01-01

    .... Our goal with our current project was to utilize breast sonography coupled with the technique of acoustic resonance to image and evaluate the breast micorcalcifications in patients prior to biopsy...

  12. Thyroid perfusion imaging as a diagnostic tool in Graves' disease. Arterial spin labeling magnetic resonance imaging vs. colour-coded Doppler ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Muessig, K. [University Hospital of Duesseldorf (Germany). Dept. of Metabolic Diseases; Leibniz Center for Diabetes Research, Duesseldorf (Germany). Inst. for Clinical Diabetology; University Hospital of Tuebingen (Germany). Div. of Endocrinology, Diabetes, Nephrology, Angiology, and Clinical Chemistry; Schraml, C.; Schwenzer, N.F. [University Hospital of Tuebingen (Germany). Dept. of Radiology, Section on Experimental Radiology; University Hospital of Tuebingen (Germany). Dept. of Radiology, Diagnostic and Interventional Radiology; Rietig, R.; Balletshofer, B. [University Hospital of Tuebingen (Germany). Div. of Endocrinology, Diabetes, Nephrology, Angiology, and Clinical Chemistry; Martirosian, P.; Haering, H.U.; Schick, F. [University Hospital of Tuebingen (Germany). Dept. of Radiology, Section on Experimental Radiology; Claussen, C.D. [University Hospital of Tuebingen (Germany). Dept. of Radiology, Diagnostic and Interventional Radiology

    2012-12-15

    Purpose: Though increased thyroid perfusion assessed by colour-coded Doppler ultrasound (CDUS) is characteristic of Graves' disease (GD), sometimes perfusion assessment by CDUS is not possible. In these cases, arterial spin labelling (ASL), a novel magnetic resonance imaging (MRI) technique allowing non-invasive thyroid perfusion quantification, may have additional diagnostic value. We aimed to evaluate the potential of ASL-MRI for assessment of increased blood perfusion in patients with GD compared to CDUS. Materials and Methods: Thyroid perfusion was measured by CDUS (volume flow rate calculated from pulsed wave Doppler signals and vessel diameter) and ASL-MRI at 1.5 T in 7 patients with GD and 10 healthy controls. Results: In patients with GD, average perfusion in both thyroid lobes was markedly increased compared to controls. Both techniques applied for volume related perfusion as well as absolute volume flow in thyroid feeding vessels provided similar results (all p = 0.0008). Using a cut-off value of 22 ml/min for the volume flow rate assessed by CDUS in the four feeding vessels allowed discrimination between patients with GD and controls in all cases. After adjusting thyroid perfusion for the differences in organ volume, both CDUS and ASL revealed also complete discrimination between health and disease. Conclusion: Thyroid perfusion measurement by ASL-MRI reliably discriminate GD from normal thyroid glands. In patients in whom thyroid arteries cannot be depicted by CDUS for technical or anatomical reasons, ASL-MRI may have additional diagnostic value. (orig.)

  13. Tissue Doppler Imaging Combined with Advanced 12-Lead ECG Analysis Might Improve Early Diagnosis of Hypertrophic Cardiomyopathy in Childhood

    Science.gov (United States)

    Femlund, E.; Schlegel, T.; Liuba, P.

    2011-01-01

    Optimization of early diagnosis of childhood hypertrophic cardiomyopathy (HCM) is essential in lowering the risk of HCM complications. Standard echocardiography (ECHO) has shown to be less sensitive in this regard. In this study, we sought to assess whether spatial QRS-T angle deviation, which has shown to predict HCM in adults with high sensitivity, and myocardial Tissue Doppler Imaging (TDI) could be additional tools in early diagnosis of HCM in childhood. Methods: Children and adolescents with familial HCM (n=10, median age 16, range 5-27 years), and without obvious hypertrophy but with heredity for HCM (n=12, median age 16, range 4-25 years, HCM or sudden death with autopsy-verified HCM in greater than or equal to 1 first-degree relative, HCM-risk) were additionally investigated with TDI and advanced 12-lead ECG analysis using Cardiax(Registered trademark) (IMED Co Ltd, Budapest, Hungary and Houston). Spatial QRS-T angle (SA) was derived from Kors regression-related transformation. Healthy age-matched controls (n=21) were also studied. All participants underwent thorough clinical examination. Results: Spatial QRS-T angle (Figure/ Panel A) and septal E/Ea ratio (Figure/Panel B) were most increased in HCM group as compared to the HCM-risk and control groups (p less than 0.05). Of note, these 2 variables showed a trend toward higher levels in HCM-risk group than in control group (p=0.05 for E/Ea and 0.06 for QRS/T by ANOVA). In a logistic regression model, increased SA and septal E/Ea ratio appeared to significantly predict both the disease (Chi-square in HCM group: 9 and 5, respectively, p less than 0.05 for both) and the risk for HCM (Chi-square in HCM-risk group: 5 and 4 respectively, p less than 0.05 for both), with further increased predictability level when these 2 variables were combined (Chi-square 10 in HCM group, and 7 in HCM-risk group, p less than 0.01 for both). Conclusions: In this small material, Tissue Doppler Imaging and spatial mean QRS-T angle

  14. Evaluation of tissue doppler echocardiography and T2* magnetic resonance imaging in iron load of patients with thalassemia major.

    Science.gov (United States)

    Saravi, Mehrdad; Tamadoni, Ahmad; Jalalian, Rozita; Mahmoodi-Nesheli, Hassan; Hojati, Mosatafa; Ramezani, Saeed

    2013-01-01

    Iron-mediated cardiomyopathy is the main complication of thalassemia major (TM) patients. Therefore, there is an important clinical need in the early diagnosis and risk stratification of patients. The aim of this study was to evaluate the efficacy of tissue doppler imaging (TDI) to study cardiac iron overload in patients with TM using T2* magnetic resonance (MR) as the gold-standard non-invasive diagnostic test. A total of 100 TM patients with the mean age of 19±7 years and 100 healthy controls 18.8±7 years were evaluated. Conventional echocardiography, TDI, and cardiac MRI T2* were performed in all subjects. TDI measures included myocardial systolic (Sm), early (Em) and late (Am) diastolic velocities at basal and middle segments of septal and lateral LV wall. The TM patients were also subgrouped according to those with iron load (T2* ≤ 20 ms) and those without (T2* > 20 ms), and also severe (T2* ≤ 10 ms) versus the non-severe (T2* ≤ 10 ms). Using T2* cardiovascular MR, abnormal myocardial iron load (T2* ≤ 20 ms) was detected in 84% of the patients and among these, 50% (42/84) had severe (T2* ≤ 10 ms) iron load. The mean T2* was 11.6±8.6 ms (5-36.7). A negative linear correlation existed between transfusion period of patients and T2* levels (r = -0.53, p=0.02). The following TDI measures were lower in patients than in controls: basal septal Am (p<0.05), mid-septal Em and Am (p<0.05), basal lateral Am (p<0.05), mid-lateral LV wall Sm (p<0.05) and Am (p<0.05). Tissue doppler imaging is helpful in predicting the presence of myocardial iron load in Thalassemia patients. Therefore, it can be used for screening of thalassemia major patients.

  15. Longitudinal microvascularity in achilles tendinopathy (power doppler ultrasound, magnetic resonance imaging time-intensity curves and the Victorian Institute of Sport Assessment-Achilles questionnaire): a pilot study

    International Nuclear Information System (INIS)

    Richards, Paula J.; McCall, Iain W.; Day, Christopher; Belcher, John; Maffulli, Nicola

    2010-01-01

    To evaluate the imaging of the natural history of Achilles tendinopathy microvascularisation in comparison with symptoms, using a validated disease-specific questionnaire [the Victorian Institute of Sport Assessment-Achilles (VISA-A)]. A longitudinal prospective pilot study of nine patients with post-contrast magnetic resonance imaging (MRI), time-intensity curve (TIC) enhancement, ultrasound (US) and power Doppler (PD) evaluation of tendinopathy of the mid-Achilles tendon undergoing conservative management (eccentric exercise) over 1 year. There were five men and four women [mean age 47 (range 30-62) years]. Six asymptomatic tendons with normal US and MRI appearance showed less enhancement than the tibial metaphysis did and showed a flat, constant, but very low rate of enhancement in the bone and Achilles tendon (9-73 arbitrary TIC units). These normal Achilles tendons on imaging showed a constant size throughout the year (mean 4.9 mm). At baseline the TIC enhancement in those with tendinopathy ranged from 90 arbitrary units to 509 arbitrary units. Over time, 11 abnormal Achilles tendons, whose symptoms settled, were associated with a reduction in MRI enhancement mirrored by a reduction in the number of vessels on power Doppler (8.0 to 2.7), with an improvement in morphology and a reduction in tendon size (mean 15-10.6 mm). One tendon did not change its abnormal imaging features, despite improving symptoms. Two patients developed contralateral symptoms and tendinopathy, and one had more abnormal vascularity on power Doppler and higher MRI TIC peaks in the asymptomatic side. In patient with conservatively managed tendinopathy of the mid-Achilles tendon over 1 year there was a reduction of MRI enhancement and number of vessels on power Doppler, followed by morphological improvements and a reduction in size. Vessels per se related to the abnormal morphology and size of the tendon rather than symptoms. Symptoms improve before the Achilles size reduces and the

  16. TISSUE DOPPLER IMAGING OF LONGITUDINAL MOVEMENT OF A FIBROUS RING OF MITRAL VALVE DURING ISOVOLUMIC PERIODS IN LEFT VENTRICULAR HYPERTROPHY

    Directory of Open Access Journals (Sweden)

    B. Amarjagal

    2007-01-01

    Full Text Available Aim. To study change of rate and duration indicators of longitudinal movement of a fibrous ring of mitral valve (MFR during isovolumic contraction (IVC and relaxation (IVR in hypertensive patients with various degree of a left ventricular hypertrophy (LVH.Material and methods. 80 hypertensive patients with moderate LVH (n=40 and severe LVH (n=40 are examined. The control group was presented by 30 healthy volunteers. Transthoracic echocardiography and Tissue Doppler imaging has been performed with ultrasonic tomograph “HDI 5000” (Philips.Results. Increase in LVH (Smm and Е/Еmm associates with reduction in systolic velocity of movement of medial MFR (Smm. There is direct relation with duration of IVC-negative and IVR-positive components and myocardium mass index. Maximal velocity of IVC-positive component increases and maximal velocity of IVR-negative component decreases when LVH is growing.Conclusion. Velocities curves of IVC and IVR were bi-phase both in healthy persons and in hypertensive patients with LVH. Velocity and duration of positive and negative components of IVC and IVR depended on LVH degree.

  17. TISSUE DOPPLER IMAGING OF LONGITUDINAL MOVEMENT OF A FIBROUS RING OF MITRAL VALVE DURING ISOVOLUMIC PERIODS IN LEFT VENTRICULAR HYPERTROPHY

    Directory of Open Access Journals (Sweden)

    B. Amarjagal

    2015-12-01

    Full Text Available Aim. To study change of rate and duration indicators of longitudinal movement of a fibrous ring of mitral valve (MFR during isovolumic contraction (IVC and relaxation (IVR in hypertensive patients with various degree of a left ventricular hypertrophy (LVH.Material and methods. 80 hypertensive patients with moderate LVH (n=40 and severe LVH (n=40 are examined. The control group was presented by 30 healthy volunteers. Transthoracic echocardiography and Tissue Doppler imaging has been performed with ultrasonic tomograph “HDI 5000” (Philips.Results. Increase in LVH (Smm and Е/Еmm associates with reduction in systolic velocity of movement of medial MFR (Smm. There is direct relation with duration of IVC-negative and IVR-positive components and myocardium mass index. Maximal velocity of IVC-positive component increases and maximal velocity of IVR-negative component decreases when LVH is growing.Conclusion. Velocities curves of IVC and IVR were bi-phase both in healthy persons and in hypertensive patients with LVH. Velocity and duration of positive and negative components of IVC and IVR depended on LVH degree.

  18. Chromospherically active stars. III - HD 26337 = EI Eri: An RS CVn candidate for the Doppler-imaging technique

    Science.gov (United States)

    Fekel, Francis C.; Quigley, Robert; Gillies, Kim; Africano, John L.

    1987-01-01

    Spectroscopic observations of the chromospherically active G5 IV single-lined binary HD 26337 = EI Eri are presented. An orbital period of 1.94722 days is found for the star. It has moderately strong Ca II H and K emission and strong ultraviolet emission features, while H-alpha is a weak absorption feature that is variable in strength. The inclination of the system is 46 + or - 12 deg, and the unseen secondary is probably a late K or early M dwarf. The v sin i of the primary is 50 + or - 3 km/s, resulting in a minimum radius of 1.9 + or - 0.1 solar radius. The star is within the required limits for Doppler imaging. The primary is close to filling its Roche lobe, resulting in a strong constraint that the mass ratio is 2.6 or greater, with a primary mass of at least 1.4 solar mass. The distance to the system is estimated at 75 pc.

  19. Study on Water Distribution Imaging in the Sand Using Propagation Velocity of Sound with Scanning Laser Doppler Vibrometer

    Science.gov (United States)

    Sugimoto, Tsuneyoshi; Nakagawa, Yutaka; Shirakawa, Takashi; Sano, Motoaki; Ohaba, Motoyoshi; Shibusawa, Sakae

    2013-07-01

    We propose a method for the monitoring and imaging of the water distribution in the rooting zone of plants using sound vibration. In this study, the water distribution measurement in the horizontal and vertical directions in the soil layer was examined to confirm whether a temporal change in the volume water content of the soil could be estimated from a temporal changes in propagation velocity. A scanning laser Doppler vibrometer (SLDV) is used for measurement of the vibration velocity of the soil surface, because the highly precise vibration velocity measurement of several many points can be carried out automatically. Sand with a uniform particle size distribution is used for the soil, as it has high plasticity; that is, the sand can return to a dry state easily even if it is soaked with water. A giant magnetostriction vibrator or a flat speaker is used as a sound source. Also, a soil moisture sensor, which measures the water content of the soil using the electric permittivity, is installed in the sand. From the experimental results of the vibration measurement and soil moisture sensors, we can confirm that the temporal changes of the water distribution in sand using the negative pressure irrigation system in both the horizontal and vertical directions can be estimated using the propagation velocity of sound. Therefore, in the future, we plan to develop an insertion-type sound source and receiver using the acceleration sensors, and we intend to examine whether our method can be applied even in commercial soil with growing plants.

  20. Ultrasound assessed thickness of burn scars in association with laser Doppler imaging determined depth of burns in paediatric patients.

    Science.gov (United States)

    Wang, Xue-Qing; Mill, Julie; Kravchuk, Olena; Kimble, Roy M

    2010-12-01

    This study describes the ultrasound assessment of burn scars in paediatric patients and the association of these scar thickness with laser Doppler imaging (LDI) determined burn depth. A total of 60 ultrasound scar assessments were conducted on 33 scars from 21 paediatric burn patients at 3, 6 and 9 months after-burn. The mean of peak scar thickness was 0.39±0.032 cm, with the thickest at 6 months (0.40±0.036 cm). There were 17 scald burn scars (0.34±0.045 cm), 4 contact burn scars (0.61±0.092 cm), and 10 flame burn scars (0.42±0.058 cm). Each group of scars followed normal distributions. Twenty-three scars had original burns successfully scanned by LDI and various depths of burns were presented by different colours according to blood perfusion units (PU), with dark blue burns, with the thinnest scars for green coloured burns and the thickest for dark blue coloured burns. Within light blue burns, grafted burns healed with significantly thinner scars than non-grafted burns. This study indicates that LDI can be used for predicting the risk of hypertrophic scarring and for guiding burn care. To our knowledge, this is the first study to correlate the thickness of burns scars by ultrasound scan with burn depth determined by LDI. Copyright © 2010 Elsevier Ltd and ISBI. All rights reserved.

  1. Thermospheric winds in the auroral oval: observations of small scale structures and rapid fluctuations by a Doppler imaging system

    International Nuclear Information System (INIS)

    Batten, S.; Rees, D.

    1990-01-01

    At high geomagnetic latitudes, thermospheric wind flows are dramatically affected by the combined effects of magnetospheric ion convection and Joule and particle heating. Thermospheric winds have been observed by ground based and space-borne Fabry-Perot interferometers (FPIs). Short period, localized wind fluctuations have always been difficult to resolve with a conventional FPI, due to the limited time and spatial resolution. However, the highest quality wind data obtained by these instruments from the middle and upper thermosphere have implied that thermospheric winds may respond to the combination of strong local ion drag forcing and heating within the auroral oval and polar cap, with spatial scale sizes of 50-500 km, and with time scales as short as 10-30 min. Since the 1982/1983 winter, a prototype Doppler Imaging System (DIS) has been operated at Kiruna (67.84 0 N, 20.42 0 E). This instrument maps thermospheric wind flows over a region some 500 km in diameter centred on Kiruna and has observed many interesting features in the thermospheric wind fields. In particular, strong local wind gradients, rapid wind reversals and small scale structures are regularly observed, particularly during geomagnetically disturbed nights. (author)

  2. Repeatability, Reproducibility and Standardisation of a Laser Doppler Imaging Technique for the Evaluation of Normal Mouse Hindlimb Perfusion

    Directory of Open Access Journals (Sweden)

    Arturo Brunetti

    2012-12-01

    Full Text Available Background. Preclinical perfusion studies are useful for the improvement of diagnosis and therapy in dermatologic, cardiovascular and rheumatic human diseases. The Laser Doppler Perfusion Imaging (LDPI technique has been used to evaluate superficial alterations of the skin microcirculation in surgically induced murine hindlimb ischemia. We assessed the reproducibility and the accuracy of LDPI acquisitions and identified several critical factors that could affect LDPI measurements in mice. Methods. Twenty mice were analysed. Statistical standardisation and a repeatability and reproducibility analysis were performed on mouse perfusion signals with respect to differences in body temperature, the presence or absence of hair, the type of anaesthesia used for LDPI measurements and the position of the mouse body. Results. We found excellent correlations among measurements made by the same operator (i.e., repeatability under the same experimental conditions and by two different operators (i.e., reproducibility. A Bland-Altman analysis showed the absence of bias in repeatability (p = 0.29 or reproducibility (p = 0.89. The limits of agreement for repeatability were –0.357 and –0.033, and for reproducibility, they were –0.270 and 0.238. Significant differences in perfusion values were observed in different experimental groups. Conclusions. Different experimental conditions must be considered as a starting point for the evaluation of new drugs and strategic therapies.

  3. Myocardial left ventricular dysfunction in patients with systemic lupus erythematosus: new insights from tissue Doppler and strain imaging.

    Science.gov (United States)

    Buss, Sebastian J; Wolf, David; Korosoglou, Grigorios; Max, Regina; Weiss, Celine S; Fischer, Christian; Schellberg, Dieter; Zugck, Christian; Kuecherer, Helmut F; Lorenz, Hanns-Martin; Katus, Hugo A; Hardt, Stefan E; Hansen, Alexander

    2010-01-01

    Systemic lupus erythematosus (SLE) is associated with high cardiovascular morbidity and mortality. Cardiovascular involvement is frequently underestimated by routine imaging techniques. Our aim was to determine if new echocardiographic imaging modalities like tissue Doppler (TDI), strain rate (SRR), and strain (SRI) imaging detect abnormalities in left ventricular (LV) function in asymptomatic patients with SLE. Sixty-seven young patients with SLE (mean age 42 +/- 10 yrs) without typical symptoms or signs of heart failure or angina, and a matched healthy control group (n = 40), underwent standard transthoracic echocardiography, TDI, SRR, and SRI imaging of the LV as well as assessment of disease characteristics. Despite findings within the normal range on routine standard 2-dimensional echocardiography, SLE was associated with significantly impaired systolic and diastolic myocardial velocities of the LV measured by TDI [mean global TDI: systolic (s): 2.9 +/- 0.9 vs 3.9 +/- 0.7 cm/s, p < 0.05; early (e): 4.3 +/- 1.5 vs 6.3 +/- 1.3 cm/s, p < 0.05; late (a): 2.9 +/- 0.8 vs 3.4 +/- 0.8 cm/s, p < 0.05; values +/- SD); SRR (s: -0.8 +/- 0.1 vs -1.1 +/- 0.1 s(-1); e: 1.1 +/- 0.2 vs 1.6 +/- 0.3 s(-1); a: 0.7 +/- 0.1 vs 1.0 +/- 0.2 s(-1); all p < 0.05); and SR (-15.11 +/- 2.2% vs -19.7 +/- 1.9%; p < 0.05) compared to the control group. Further, elevated disease activity, measured with the ECLAM and the SLEDAI score, resulted in significantly lower values for LV longitudinal function measured by SRR and SR, but not by TDI. SLE is associated with a significant impairment of systolic and diastolic LV longitudinal function in patients without cardiac symptoms. New imaging modalities provide earlier insight into cardiovascular involvement in SLE and seem to be superior to standard echocardiography to detect subclinical myocardial disease.

  4. Stellar magnetometry and Zeeman-Doppler imaging in exo-planets research using the radial velocity method

    International Nuclear Information System (INIS)

    Hebrard, Elodie

    2015-01-01

    Forthcoming instruments dedicated to exo-planets detection through the radial velocity method are numerous, and increasingly more accurate. However this method is indirect: orbiting planets are detected and characterised from variations on the spectrum of the host star. We are therefore sensitive to all activity phenomena impacting the spectrum and producing a radial velocity signal (pulsation, granulation, spots, magnetic cycle...). The detection of rocky Earth-like planets around main-sequence stars, and of hot Jupiters into young systems, are currently limited by the intrinsic magnetic activity of the host stars. The radial velocity fluctuations caused by activity (activity jitter) can easily mimic and hide signals from such planets, whose amplitude is of a few m/s and hundreds of m/s, respectively. As a result, the detection threshold of exo-planets is largely set by the stellar activity level. Currently, efforts are invested to overcome this intrinsic limitation. During my PhD, I studied how to take advantage of imaging tomographic techniques (Zeeman-Doppler imaging, ZDI) to characterize stellar activity and magnetic field topologies, ultimately allowing us to filter out the activity jitter. My work is based on spectro-polarimetric observations of a sample of weakly-active M-dwarfs, and young active T Tauri stars. Using a modified version of ZDI, we are able to reconstruct the distribution of active regions, and then model the induced stellar signal allowing us to clean RV curves from the activity jitter. First tests demonstrate that this technique can be efficient enough to recover the planet signal, especially for the more active ones. (author)

  5. A comparative study of colour and perfusion between two different post surgical scars. Do the laser Doppler imager and the colorimeter measure the same features of a scar?

    Science.gov (United States)

    Mermans, J F; Peeters, W J; Dikmans, R; Serroyen, J; van der Hulst, R R J W; Van den Kerckhove, E

    2013-05-01

    The purpose of this study was to investigate the influence of different located post surgical scars on both perfusion and redness. The pattern of change and correlation between perfusion and redness of post surgical scars is also examined. In this study, we measured redness and perfusion of the abdominal and breast scar of 24 women undergoing breast reconstruction with Deep Inferior Epigastric Perforator Free Flap surgery with the Minolta Chromameter CR-400/410 and the Moor Instruments laser Doppler imager 12IR, respectively, at different intervals post-operatively. The laser Doppler imager gives significantly higher values for the abdominal compared with the breast scar. There was no consistent correlation found between perfusion and redness at the different test moments for both locations. The scores of both parameters were significantly associated after 9 months follow-up for both locations. Scars closed with higher mechanical force show higher perfusion and prolonged activity; and more redness is associated with more perfusion for both post surgical scars. Nevertheless, there was no consistent correlation found between these parameters making the laser Doppler imager and the Colorimeter still non-replaceable instruments. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  6. Quantitative Assessment of Synovial Vascularity Using Contrast-Enhanced Power Doppler Ultrasonography: Correlation with Histologic Findings and MR Imaging Findings in Arthritic Rabbit Knee Model

    International Nuclear Information System (INIS)

    Lee, Sang Hoon; Shin, Myung Jin; Kim, Seong Moon; Kim, Namkug; Suh, Sang Hyun; Suh, Jin Suck

    2008-01-01

    To validate contrast-enhanced power Doppler ultrasonography (PD US) for the evaluation of synovial vascularity in an arthritic rabbit knee model in correlation with MR and histological findings. Power Doppler ultrasonography was performed for carrageenin-induced arthritic left knee and control right knee of 13 rabbits, first without and then with sonic contrast agent enhancement (Levovist, Schering, Berlin Germany), followed by gadolinium-enhanced MR imaging. Synovial vascularity was quantitatively assessed by calculating the color pixel area in power Doppler sonography using a computer-aided image analysis program and by grading the enhancement on MR images: grade 1, enhancement of knee joint is less than one-third of the area; grade 2, one-third to two-thirds enhancement; and grade 3, more than two-thirds enhancement. Microvessel density (MVD) was measured on slides stained immunohistochemically for CD31 antigen for histological assessment. The mean area of color pixels in PD US changed from 4.37 to 16.42 mm 2 in the arthritic knee after enhancement (p 2 in the control knee (p 0.05). Sonic contrast-enhanced PD US improves the visualization of synovial vascularity and allows quantitative measurement in experimentally induced rabbit arthritic knees

  7. A study of a space-station-associated multiple spacecraft Michelson spatial interferometer

    Science.gov (United States)

    Stachnik, R. V.

    1983-01-01

    One approach to Michelson spatial interferometry at optical wavelengths involves use of an array of spacecraft in which two widely-separated telescopes collect light from a star and direct it to a third, centrally-located, device which combines the beams in order to detect and measure interference fringes. The original version of a spacecraft array for Michelson spatial interferometry (SAMSI) was modified so that the system uses the fuel resupply capability of a space station. The combination of this fuel resupply capability with a method of obtaining image Fourier transform phase information, necessary for full image reconstruction, permits SAMSI to be used to synthesize images equivalent to those produced by huge apertures in space. Synthesis of apertures in the 100 to 500 meter range is discussed. Reconstruction can be performed to a visual magnitude of at least 8 for a 100 A passband in 9 hours. Data are simultaneously collected for image generation from 0.1 micron to 18 microns. In the one-dimensional mode, measurements can be made every 90 minutes (including acquisition and repointing time) for objects as faint as 19th magnitude in the visible.

  8. Laser Doppler imaging of cutaneous blood flow through transparent face masks: a necessary preamble to computer-controlled rapid prototyping fabrication with submillimeter precision.

    Science.gov (United States)

    Allely, Rebekah R; Van-Buendia, Lan B; Jeng, James C; White, Patricia; Wu, Jingshu; Niszczak, Jonathan; Jordan, Marion H

    2008-01-01

    A paradigm shift in management of postburn facial scarring is lurking "just beneath the waves" with the widespread availability of two recent technologies: precise three-dimensional scanning/digitizing of complex surfaces and computer-controlled rapid prototyping three-dimensional "printers". Laser Doppler imaging may be the sensible method to track the scar hyperemia that should form the basis of assessing progress and directing incremental changes in the digitized topographical face mask "prescription". The purpose of this study was to establish feasibility of detecting perfusion through transparent face masks using the Laser Doppler Imaging scanner. Laser Doppler images of perfusion were obtained at multiple facial regions on five uninjured staff members. Images were obtained without a mask, followed by images with a loose fitting mask with and without a silicone liner, and then with a tight fitting mask with and without a silicone liner. Right and left oblique images, in addition to the frontal images, were used to overcome unobtainable measurements at the extremes of face mask curvature. General linear model, mixed model, and t tests were used for data analysis. Three hundred seventy-five measurements were used for analysis, with a mean perfusion unit of 299 and pixel validity of 97%. The effect of face mask pressure with and without the silicone liner was readily quantified with significant changes in mean cutaneous blood flow (P face masks. Perfusion decreases with the application of pressure and with silicone. Every participant measured differently in perfusion units; however, consistent perfusion patterns in the face were observed.

  9. A reconfigurable optofluidic Michelson interferometer using tunable droplet grating.

    Science.gov (United States)

    Chin, L K; Liu, A Q; Soh, Y C; Lim, C S; Lin, C L

    2010-04-21

    This paper presents a novel optofluidic Michelson interferometer based on droplet microfluidics used to create a droplet grating. The droplet grating is formed by a stream of plugs in the microchannel with constant refractive index variation. It has a real-time tunability in the grating period through varying the flow rates of the liquids and index variation via different combinations of liquids. The optofluidic Michelson interferometer is highly sensitive and is suitable for the measurement of biomedical and biochemical buffer solutions. The experimental results show that it has a sensitivity of 66.7 nm per refractive index unit (RIU) and a detection range of 0.086 RIU.

  10. EIT Based Gas Detector Design by Using Michelson Interferometer

    International Nuclear Information System (INIS)

    Abbasian, K.; Rostami, A.; Abdollahi, M. H.

    2011-01-01

    Electromagnetically induced transparency (EIT) is one of the interesting phenomena of light-matter interaction which modifies matter properties for propagation of light. In other words, we can change the absorption and refractive index (RI) in neighborhood of the resonant frequency using EIT. In this paper, we have doped 3-level quantum dots in one of the Michelson Interferometer's mirror and used EIT to change its RI. So, a controllable phase difference between lights in two arms of interferometer is created. Long response time is the main drawback of Michelson interferometer based sensor, which is resolved by this technique.

  11. Study on the wide-angle Michelson interferometer with large air gap.

    Science.gov (United States)

    Gao, Haiyang; Tang, Yuanhe; Hua, Dengxin; Liu, Hanchen

    2011-10-10

    A wide-angle Michelson interferometer with large air gap is proposed to effectively reduce the size of the glass arms and constraint on material. It provides a novel and practical instrument for ground based wind measurement of the upper atmosphere. The field widening conditions for the large air gap are calculated in theory. For the five spectral lines of 557.7 nm, 630.0 nm, 732.0 nm, 834.6 nm, and 865.7 nm, the optimal results under ideal condition are obtained with air gaps of 1.0 cm, 1.5 cm, and 2.0 cm, respectively. With the fixed optical path difference (OPD) of 7.495 cm, three pairs of glass arms are optimized. The pair with length of 1.5 cm for air gap, 5.765 cm for H-ZF12, and 2.956 cm for H-ZLaF54, has better effect of field widening than the other two pairs and its OPD variation is only within 0.30 wavelengths at incident angle of 3°. For developing a more practical wide-angle Michelson interferometer, the H-K9L glass with size of 4.445 cm is employed as the arm material of solid interferometer. The experiment for field of view of 3° is designed and the data processing and analysis for 60 images show the agreement between experimental results and theoretical simulation. The OPD variations are only within 0.27 wavelengths for image edge. The feasibility and practicality of the wide-angle Michelson interferometer with large air gap is proved by means of theory and experiment. © 2011 Optical Society of America

  12. Diagnosis of right-sided varicocele: A retrospective comparative study between clinical examination, Doppler findings, US imaging and vascular anatomy at phlebography

    International Nuclear Information System (INIS)

    Cariati, Maurizio; Pieri, Stefano; Agresti, Paolo; Cariati, Massimiliano; Candito, Davide Fabio; Damiani, Giovanni; Marzano, Domenico

    2012-01-01

    Historically varicocele is diagnosed almost exclusively on the left side. The introduction of new imaging techniques has allowed the identification and characterization of right varicocele. This study aims to compare the diagnostic accuracy of various imaging techniques to data obtained using phlebography in the diagnosis of right varicocele. Patients treated for isolated right varicocele between 1992 and 2010 were retrospectively identified. Data from clinical examination, Doppler-USS, Color-Doppler-USS and Retrograde Phlebography were collected for each patient. 133 out of 4305 patients (3.1%) presented with an isolated right varicocele. 34 of these patients (25.6%) presented with palpable right varicocele. Doppler-USS identified various degrees of type I right venous reflux in 90 patients (67.7%). Phlebography showed venous reflux in all the patients (133), although with variability in terms of internal spermatic vein anatomy. Right varicocele is characterized by predictable anatomic features. Identification and characterization of these features is useful in guiding percutaneous treatment, allowing to optimize radiological display and reducing failure rate

  13. Diagnosis of right-sided varicocele: A retrospective comparative study between clinical examination, Doppler findings, US imaging and vascular anatomy at phlebography

    Energy Technology Data Exchange (ETDEWEB)

    Cariati, Maurizio, E-mail: davide.candito@libero.it [U.O.C. Radiologia, A.O. San Carlo Borromeo, via Pio II 3, 20153 Milan (Italy); Pieri, Stefano, E-mail: stefano.pieri@scamilloforlanini.rm.it [U.O.C. Diagnostica per Immagini Cardioscienze, A.O. San Camillo - Forlanini, Piazza Carlo Forlanini 1, 00151 Rome (Italy); Agresti, Paolo, E-mail: paolo.agresti@scamilloforlanini.rm.it [U.O.C. Diagnostica per Immagini Cardioscienze, A.O. San Camillo - Forlanini, Piazza Carlo Forlanini 1, 00151 Rome (Italy); Cariati, Massimiliano, E-mail: massimiliano.cariati@kcl.ac.uk [Department of Academic Oncology, King' s College London, 3rd Floor Bermondsey Wing, Guy' s Hospital, Great Maze Pond, London SE1 9RT (United Kingdom); Candito, Davide Fabio, E-mail: davide.candito@yahoo.it [Scuola di Specializzazione in Radiodiagnostica, Facoltà di Medicina e Chirurgia, Università degli studi di Milano, via Festa del Perdono 7, 20122 Milan (Italy); Damiani, Giovanni, E-mail: damiani_giovanni@libero.it [Scuola di Specializzazione in Radiodiagnostica, Facoltà di Medicina e Chirurgia, Università degli studi di Milano, via Festa del Perdono 7, 20122 Milan (Italy); Marzano, Domenico, E-mail: domenico.marzano@scamilloforlanini.rm.it [U.O.C. Urologia, A.O. San Camillo - Forlanini, Piazza Carlo Forlanini 1, 00151 Rome (Italy)

    2012-09-15

    Historically varicocele is diagnosed almost exclusively on the left side. The introduction of new imaging techniques has allowed the identification and characterization of right varicocele. This study aims to compare the diagnostic accuracy of various imaging techniques to data obtained using phlebography in the diagnosis of right varicocele. Patients treated for isolated right varicocele between 1992 and 2010 were retrospectively identified. Data from clinical examination, Doppler-USS, Color-Doppler-USS and Retrograde Phlebography were collected for each patient. 133 out of 4305 patients (3.1%) presented with an isolated right varicocele. 34 of these patients (25.6%) presented with palpable right varicocele. Doppler-USS identified various degrees of type I right venous reflux in 90 patients (67.7%). Phlebography showed venous reflux in all the patients (133), although with variability in terms of internal spermatic vein anatomy. Right varicocele is characterized by predictable anatomic features. Identification and characterization of these features is useful in guiding percutaneous treatment, allowing to optimize radiological display and reducing failure rate.

  14. Feasibility and diagnostic power of transthoracic coronary Doppler for coronary flow velocity reserve in patients referred for myocardial perfusion imaging

    Directory of Open Access Journals (Sweden)

    Nylander Eva

    2008-03-01

    Full Text Available Abstract Background Myocardial perfusion imaging (MPI, using single photon emission computed tomography (SPECT is a validated method for detecting coronary artery disease. Transthoracic Doppler echocardiography (TTDE of flow at rest and during adenosine provocation has previously been evaluated in selected patient groups. We therefore wanted to compare the diagnostic ability of TTDE in the left anterior descending coronary artery (LAD to that of MPI in an unselected population of patients with chest pain referred for MPI. Our hypothesis was that TTDE with high accuracy would identify healthy individuals and exclude them from the need for further studies, enabling invasive investigations to be reserved for patients with a high probability of disease. Methods Sixty-nine patients, 44 men and 25 women, age 61 ± 10 years (range 35–82, with a clinical suspicion of stress induced myocardial ischemia, were investigated. TTDE was performed at rest and during adenosine stress for myocardial scintigraphy. Results We found that coronary flow velocity reserve (CFVR determined from diastolic measurements separated normal from abnormal MPI findings with statistical significance. TTDE identified coronary artery disease, defined from MPI, as reversible ischemia and/or permanent defect, with a sensitivity of 60% and a specificity of 79%. The positive predictive value was 43% and the negative predictive value was 88%. There was an overlap between groups which could be due to abnormal endothelial function in patients with normal myocardial perfusion having either hypertension or diabetes. Conclusion TTDE is an attractive non-invasive method to evaluate chest pain without the use of isotopes, but the diagnostic power is strongly dependent on the population investigated. Even in our heterogeneous clinical cardiac population, we found that CFVR>2 in the LAD excluded significant coronary artery disease detected by MPI.

  15. Comparison of Laser Doppler Imaging (LDI) and clinical assessment in differentiating between superficial and deep partial thickness burn wounds.

    Science.gov (United States)

    Jan, Saadia Nosheen; Khan, Farid Ahmed; Bashir, Muhammad Mustehsan; Nasir, Muneeb; Ansari, Hamid Hussain; Shami, Hussan Birkhez; Nazir, Umer; Hanif, Asif; Sohail, Muhammad

    2018-03-01

    To compare the accuracy of Laser Doppler Imaging (LDI) and clinical assessment in differentiating between superficial and deep partial thickness burns to decide whether early tangential excision and grafting or conservative management should be employed to optimize burn and patient management. March 2015 to November 2016. Ninety two wounds in 34 patients reporting within 5days of less than 40% burn surface area were included. Unstable patients, pregnant females and those who expired were excluded. The wounds were clinically assessed and LDI done concomitantly Plastic Surgeons blinded to each other's findings. Wound appearance, color, blanching, pain, hair follicle dislodgement were the clinical parameters that distinguished between superficial and deep partial thickness burns. On day 21, the wounds were again assessed for the presence of healing by the same plastic surgeons. The findings were correlated with the initial findings on LDI and clinical assessment and the results statistically analyzed. The data of 92 burn wounds was analyzed using SPSS (ver. 17). Clinical assessment correctly identified the depth of 75 and LDI 83 wounds, giving diagnostic accuracies of 81.52% and 90.21% respectively. The sensitivity of clinical assessment was 81% and of LDI 92.75%, whereas the specificity was 82% for both. The positive predictive value was 93% for clinical assessment and 94% for LDI while the negative predictive value was 59% and 79% respectively. Predictive accuracy of LDI was found to be better than clinical assessment in the prediction of wound healing, the gold standard for wound healing being 21 days. As such it can prove to be a reliable and viable cost effective alternative per se to clinical assessment. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

  16. Reproducibility of non-invasive assessment of skin endothelial function using laser Doppler flowmetry and laser speckle contrast imaging.

    Directory of Open Access Journals (Sweden)

    Cyril Puissant

    Full Text Available Endothelial dysfunction precedes atherosclerosis. Vasodilation induced by acetylcholine (ACh is a specific test of endothelial function. Reproducibility of laser techniques such as laser-Doppler-flowmetry (LDF and Laser-speckle-contrast-imaging (LSCI to detect ACh vasodilation is debated and results expressions lack standardization. We aimed to study at a 7-day interval (i the inter-subject reproducibility, (ii the intra-subjects reproducibility, and (iii the effect of the results expressions over variability.Using LDF and LSCI simultaneously, we performed two different ACh-iontophoresis protocols. The maximal ACh vasodilation (peak-ACh was expressed as absolute or normalized flow or conductance values. Inter-subject reproducibility was expressed as coefficient of variation (inter-CV,%. Intra-subject reproducibility was expressed as within subject coefficients of variation (intra-CV,%, and intra-class correlation coefficients (ICC. Fifteen healthy subjects were included. The inter-subject reproducibility of peak-ACh depended upon the expression of the results and ranged from 55% to 162% for LDF and from 17% to 83% for LSCI. The intra-subject reproducibility (intra-CV/ICC of peak-ACh was reduced when assessed with LSCI compared to LDF no matter how the results were expressed and whatever the protocol used. The highest intra-subject reproducibility was found using LSCI. It was 18.7%/0.87 for a single current stimulation (expressed as cutaneous vascular conductance and 11.4%/0.61 for multiple current stimulations (expressed as absolute value.ACh-iontophoresis coupled with LSCI is a promising test to assess endothelial function because it is reproducible, safe, and non-invasive. N°: NCT01664572.

  17. Left ventricular diastolic dyssynchrony assessed with phase analysis of gated myocardial perfusion SPECT: a comparison with tissue Doppler imaging

    International Nuclear Information System (INIS)

    Boogers, Mark J.; Veltman, Caroline E.; Chen, Ji; Garcia, Ernest V.; Bommel, Rutger J. van; Mooyaart, Eline A.Q.; Wall, Ernst E. van der; Schalij, Martin J.; Bax, Jeroen J.; Delgado, Victoria; Younis, Imad Al; Hiel, Bernies van der; Dibbets-Schneider, Petra

    2011-01-01

    The aim of the current study was to evaluate the feasibility of phase analysis on gated myocardial perfusion SPECT (GMPS) for the assessment of left ventricular (LV) diastolic dyssynchrony in a head-to-head comparison with tissue Doppler imaging (TDI). The population consisted of patients with end-stage heart failure of New York Heart Association functional class III or IV with a reduced LV ejection fraction of ≤35%. LV diastolic dyssynchrony was calculated using TDI as the maximal time delay between early peak diastolic velocities of two opposing left ventricle walls (diastolic mechanical delay). Significant LV diastolic dyssynchrony was defined as a diastolic mechanical delay of >55 ms on TDI. Furthermore, phase analysis on GMPS was performed to evaluate LV diastolic dyssynchrony; diastolic phase standard deviation (SD) and histogram bandwidth (HBW) were used as markers of LV diastolic dyssynchrony. A total of 150 patients (114 men, mean age 66.0 ± 10.4 years) with end-stage heart failure were enrolled. Both diastolic phase SD (r = 0.81, p 55 ms) showed significantly larger diastolic phase SD (68.1 ± 13.4 vs. 40.7 ± 14.0 , p < 0.01) and diastolic HBW (230.6 ± 54.3 vs. 129.0 ± 55.6 , p < 0.01) as compared to patients without LV diastolic dyssynchrony on TDI (≤55 ms). Finally, phase analysis on GMPS showed a good intra- and interobserver reproducibility for the determination of diastolic phase SD (ICC 0.97 and 0.88) and diastolic HBW (ICC 0.98 and 0.93). Phase analysis on GMPS showed good correlations with TDI for the assessment of LV diastolic dyssynchrony. (orig.)

  18. Power Doppler ultrasonography for assessment of synovitis in the metacarpophalangeal joints of patients with rheumatoid arthritis: a comparison with dynamic magnetic resonance imaging

    DEFF Research Database (Denmark)

    Szkudlarek, Marcin; Court-Payen, M; Strandberg, C

    2001-01-01

    OBJECTIVE: To evaluate the effectiveness of power Doppler ultrasonography (PDUS) for assessing inflammatory activity in the metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA), using dynamic magnetic resonance imaging (MRI) as a reference method. METHODS: PDUS and dynamic...... MRI were performed on 54 MCP joints of 15 patients with active RA and on 12 MCP joints of 3 healthy controls. PDUS was performed with a LOGIQ 500 unit by means of a 7-13-MHz linear array transducer. Later the same day, MRI was performed with a 1.0T MR unit. A series of 24 coronal T1-weighted images...

  19. Doppler optical cardiogram gated 2D color flow imaging at 1000 fps and 4D in vivo visualization of embryonic heart at 45 fps on a swept source OCT system.

    Science.gov (United States)

    Mariampillai, Adrian; Standish, Beau A; Munce, Nigel R; Randall, Cristina; Liu, George; Jiang, James Y; Cable, Alex E; Vitkin, I A; Yang, Victor X D

    2007-02-19

    We report a Doppler optical cardiogram gating technique for increasing the effective frame rate of Doppler optical coherence tomography (DOCT) when imaging periodic motion as found in the cardiovascular system of embryos. This was accomplished with a Thorlabs swept-source DOCT system that simultaneously acquired and displayed structural and Doppler images at 12 frames per second (fps). The gating technique allowed for ultra-high speed visualization of the blood flow pattern in the developing hearts of African clawed frog embryos (Xenopus laevis) at up to 1000 fps. In addition, four-dimensional (three spatial dimensions + temporal) Doppler imaging at 45 fps was demonstrated using this gating technique, producing detailed visualization of the complex cardiac motion and hemodynamics in a beating heart.

  20. Proposal of Michelson-Morley experiment via single photon interferometer: Interpretation of Michelson-Morley experimental results using de Broglie-Bohm picture

    OpenAIRE

    Sato, Masanori

    2004-01-01

    The Michelson-Morley experiment is considered via a single photon interferometer and we propose the interpretation of the Michelson-Morley experimental results using de Broglie-Bohm picture. We point out that the Michelson-Morley experiment revealed the interference of photons, however, it did not reveal the photons simultaneous arrival at the beam splitter. According to the de Broglie-Bohm picture, the quantum potential nonlocally determines the interference of photons. The interference of t...

  1. Quantitative Phase Determination by Using a Michelson Interferometer

    Science.gov (United States)

    Pomarico, Juan A.; Molina, Pablo F.; D'Angelo, Cristian

    2007-01-01

    The Michelson interferometer is one of the best established tools for quantitative interferometric measurements. It has been, and is still successfully used, not only for scientific purposes, but it is also introduced in undergraduate courses for qualitative demonstrations as well as for quantitative determination of several properties such as…

  2. Measurement of Refractive Index Using a Michelson Interferometer.

    Science.gov (United States)

    Fendley, J. J.

    1982-01-01

    Describes a novel and simple method of measuring the refractive index of transparent plates using a Michelson interferometer. Since it is necessary to use a computer program when determining the refractive index, undergraduates could be given the opportunity of writing their own programs. (Author/JN)

  3. Plasma flow velocity measurements using a modulated Michelson interferometer

    NARCIS (Netherlands)

    Howard, J.; Meijer, F. G.

    1997-01-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (C) 1997 Elsevier Science S.A.

  4. Optical design of a Michelson wide-field multiple-aperture telescope

    Science.gov (United States)

    Cassaing, Frederic; Sorrente, Beatrice; Fleury, Bruno; Laubier, David

    2004-02-01

    Multiple-Aperture Optical Telescopes (MAOTs) are a promising solution for very high resolution imaging. In the Michelson configuration, the instrument is made of sub-telescopes distributed in the pupil and combined by a common telescope via folding periscopes. The phasing conditions of the sub-pupils lead to specific optical constraints in these subsystems. The amplitude of main contributors to the wavefront error (WFE) is given as a function of high level requirements (such as field or resolution) and free parameters, mainly the sub-telescope type, magnification and diameter. It is shown that for the periscopes, the field-to-resolution ratio is the main design driver and can lead to severe specifications. The effect of sub-telescopes aberrations on the global WFE can be minimized by reducing their diameter. An analytical tool for the MAOT design has been derived from this analysis, illustrated and validated in three different cases: LEO or GEO Earth observation and astronomy with extremely large telescopes. The last two cases show that a field larger than 10 000 resolution elements can be covered with a very simple MAOT based on Mersenne paraboloid-paraboloid sub-telescopes. Michelson MAOTs are thus a solution to be considered for high resolution wide-field imaging, from space or ground.

  5. High-flow-velocity and shear-rate imaging by use of color Doppler optical coherence tomography

    NARCIS (Netherlands)

    van Leeuwen, T. G.; Kulkarni, M. D.; Yazdanfar, S.; Rollins, A. M.; Izatt, J. A.

    1999-01-01

    Color Doppler optical coherence tomography (CDOCT) is capable of precise velocity mapping in turbid media. Previous CDOCT systems based on the short-time Fourier transform have been limited to maximum flow velocities of the order of tens of millimeters per second. We describe a technique, based on

  6. Comparison of laser Doppler imaging, fingertip lacticemy test, and nailfold capillaroscopy for assessment of digital microcirculation in systemic sclerosis.

    Science.gov (United States)

    Correa, Marcelo Ju; Andrade, Luis Ec; Kayser, Cristiane

    2010-01-01

    Laser Doppler imaging (LDI) is a relatively new method for assessing the functional aspect of superficial skin blood flow in systemic sclerosis (SSc) and Raynaud's phenomenon. The present study investigated the dynamic behavior of digital skin microvascular blood flow before and after cold stimulus (CS) in SSc patients and in healthy controls by means of a comprehensive approach of the functional (LDI), morphological (nailfold capillaroscopy (NFC)), and biochemical (fingertip lacticemy (FTL)) microcirculation components. Forty-four SSc patients and 40 healthy controls were included. After acclimatization, all subjects underwent NFC followed by LDI and FTL measurement. NFC was performed with a stereomicroscope under 10× to 20× magnification in the 10 digits of the hands. Skin blood flow of the dorsum of four fingertips (excluding the thumb) of the left hand was measured using LDI at baseline and for 30 minutes after CS. The mean finger blood flow (FBF) of the four fingertips was expressed as arbitrary perfusion units. FTL was determined on the fourth left finger before (pre-CS-FTL) and 10 minutes after CS. LDI showed significantly lower mean baseline FBF in SSc patients as compared with controls (296.9 ± 208.8 vs. 503.6 ± 146.4 perfusion units; P < 0.001) and also at all time points after CS (P < 0.001). There was a significant decrease in mean FBF after CS as compared with baseline in SSc patients and in controls, followed by recovery of the blood flow 27 minutes after CS in healthy controls, but not in SSc patients. FBF tended to be lower in patients with digital scars and previous ulceration/amputation (P = 0.06). There was no correlation between mean baseline FBF and NFC parameters. Interestingly, there was a negative correlation between FTL and FBF measured by LDI in basal conditions and 10 minutes after CS in SSc patients. LDI showed lower digital blood flow in SSc patients when compared with healthy controls and correlated well with FTL both at baseline

  7. Color Doppler imaging and measurements of intraovarian and intrauterine vascularization on basal ultrasound examination in spontaneous ovulatory and anovulatory cycles

    Directory of Open Access Journals (Sweden)

    Kutlešić Ranko

    2008-01-01

    Full Text Available Background/Aim. Any organs functioning directly depends on vascularization. It applies also to the uterus and ovary which go through changes of vascularization during a menstruation cycle. The aim of this investigation was to determine differences in intrauterine and ovarian stromal arterioral blood flow on basal ultrasound examination (day 2-4 between spontaneous ovulatory and anovulatory cycles. Methods. This prospective clinical investigation included 205 patients divided into two groups: with ovulatory and with anovulatory cycles. Results. Resistance to ovarian arterioral stromal blood flow was significantly lower in the patients with ovulatory cycles (pulsatile index - PI 0.97 ± 0.4 vs 1.93 ± 1.37; p = 0.001737; and (resistance index - RI 0.55 ± 0.12 vs 0.68 ± 0.14; p = 0.040033. There were no statistically significant differences in arcuate arterioral blood flow in the pateints with ovulatory and anovulatory cycles (PI 1.21 ± 0.34 vs 61 ± 0,61 p = 0.136161 and RI 0.64 ± 0.11 vs 0.74 ± 0.07; p = 0.136649. The patients with ovulatory cycles had lower uterine radial arterioral blood flow than the patients with anovulatory cycles (PI 1.001 ± 0.22 vs 1.61 ± 0.23 p = 0.007501 and RI 0.55 ± 0.08 vs 0.71 ± 0.12; p = 0,0460113. The patients with ovulatory cycles had lower subendometrial arterioral blood flow resistance (PI 0.69 ± 0.19 vs 1.385±0.09; p = 0.00622 and RI 0.44 ± 0.09 vs 0.65 ± 0.02; p = 0.027458. Conclusion. Color Doppler ultrasuond imaging and measurements of intrauterine and ovarian stromal arterioral blood flow on basal ultrasound examination (day 2-4, showed lower resistance to blood flow in ovulatory than in anovulatory cycles.

  8. Study of the Myocardial Contraction and Relaxation Velocities through Doppler Tissue Imaging Echocardiography: A New Alternative in the Assessment of the Segmental Ventricular Function

    Directory of Open Access Journals (Sweden)

    Silva Carlos Eduardo Suaide

    2002-01-01

    Full Text Available OBJECTIVE: Doppler tissue imaging (DTI enables the study of the velocity of contraction and relaxation of myocardial segments. We established standards for the peak velocity of the different myocardial segments of the left ventricle in systole and diastole, and correlated them with the electrocardiogram. METHODS: We studied 35 healthy individuals (27 were male with ages ranging from 12 to 59 years (32.9 ± 10.6. Systolic and diastolic peak velocities were assessed by Doppler tissue imaging in 12 segments of the left ventricle, establishing their mean values and the temporal correlation with the cardiac cycle. RESULTS: The means (and standard deviation of the peak velocities in the basal, medial, and apical regions (of the septal, anterior, lateral, and posterior left ventricle walls were respectively, in cm/s, 7.35(1.64, 5.26(1.88, and 3.33(1.58 in systole and 10.56(2.34, 7.92(2.37, and 3.98(1.64 in diastole. The mean time in which systolic peak velocity was recorded was 131.59ms (±19.12ms, and diastolic was 459.18ms (±18.13ms based on the peak of the R wave of the electrocardiogram. CONCLUSION: In healthy individuals, maximum left ventricle segment velocities decreased from the bases to the ventricular apex, with certain proportionality between contraction and relaxation (P<0.05. The use of Doppler tissue imaging may be very helpful in detecting early alterations in ventricular contraction and relaxation.

  9. Two-dimensional power Doppler-three-dimensional ultrasound imaging of a cesarean section dehiscence with utero-peritoneal fistula: a case report

    Directory of Open Access Journals (Sweden)

    Royo Pedro

    2009-01-01

    Full Text Available Abstract Introduction An imaging diagnosis after an iterative cesarean delivery is reviewed demonstrating a fine ultrasound-pathologic correlation. Case presentation A 33-year-old woman (G3, P3 presented referring intense dysmenorrhea and intermenstrual spotting since her third cesarean delivery, 1 year before. A cesarean section dehiscence with utero-peritoneal fistula was diagnosed by transvaginal ultrasound. Conclusion We can conclude that transvaginal two-dimensional power Doppler and three-dimensional ultrasound are highly accurate in detecting cesarean section dehiscence and uterine fistula.

  10. Usefulness of the myocardial performance index determined by tissue Doppler imaging m-mode for predicting mortality in the general population

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Møgelvang, Rasmus; Haahr-Pedersen, Sune Ammentorp

    2011-01-01

    The objective of this study was to evaluate the prognostic value of the myocardial performance index (MPI), assessed by color-coded tissue Doppler imaging (TDI) M-mode through the anterior mitral leaflet. Color TDI M-mode through the mitral leaflet is an easy, very fast, and precise method...... ventricular in- and outflow using standard procedures (MPI(conv)) and by color-coded TDI M-mode through the mitral leaflet in the apical 4-chamber view (MPI(TDI)). MPI(TDI) was increased in subjects with coronary heart disease (CHD) compared to controls, even after multivariable adjustment (p

  11. Ghost reflections of Gaussian beams in anamorphic optical systems with an application to Michelson interferometer.

    Science.gov (United States)

    Abd El-Maksoud, Rania H

    2016-02-20

    In this paper, a methodology is developed to model and analyze the effect of undesired (ghost) reflections of Gaussian beams that are produced by anamorphic optical systems. The superposition of these beams with the nominal beam modulates the nominal power distribution at the recording plane. This modulation may cause contrast reduction, veiling parts of the nominal image, and/or the formation of spurious interference fringes. The developed methodology is based on synthesizing the beam optical paths into nominal and ghost optical beam paths. Similar to the nominal beam, we present the concept that each ghost beam is characterized by a beam size, wavefront radius of curvature, and Gouy phase in the paraxial regime. The nominal and ghost beams are sequentially traced through the system and formulas for estimating the electric field magnitude and phase of each ghost beam at the recording plane are presented. The effective electric field is the addition of the individual nominal and ghost electric fields. Formulas for estimating Gouy phase, the shape of the interference fringes, and the central interference order are introduced. As an application, the theory of the formation of the interference fringes by Michelson interferometer is presented. This theory takes into consideration the ghost reflections that are formed by the beam splitter. To illustrate the theory and to show its wide applicability, simulation examples that include a Mangin mirror, a Michelson interferometer, and a black box optical system are provided.

  12. Doppler tomography in fusion plasmas and astrophysics

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Heidbrink, W. W.

    2015-01-01

    Doppler tomography is a well-known method in astrophysics to image the accretion flow, often in the shape of thin discs, in compact binary stars. As accretion discs rotate, all emitted line radiation is Doppler-shifted. In fast-ion Dα (FIDA) spectroscopy measurements in magnetically confined plasma......, the Dα-photons are likewise Doppler-shifted ultimately due to gyration of the fast ions. In either case, spectra of Doppler-shifted line emission are sensitive to the velocity distribution of the emitters. Astrophysical Doppler tomography has lead to images of accretion discs of binaries revealing bright...... and limits, analogies and differences in astrophysical and fusion plasma Doppler tomography and what can be learned by comparison of these applications....

  13. Clinical outcome and imaging changes after intraarticular (IA) application of etanercept or methylprednisolone in rheumatoid arthritis: Magnetic resonance imaging and ultrasound-Doppler show no effect of IA injections in the wrist after 4 weeks

    DEFF Research Database (Denmark)

    Boesen, M.; Boesen, L.; Jensen, K.E.

    2008-01-01

    Objective. To assess the magnetic resonance imaging (MRI) and ultrasound (US) changes in the wrist of patients with rheumatoid arthritis (RA) 4 weeks after an US guided intraarticular (IA) injection. Methods. Contrast enhanced MRI and US-Doppler were performed at baseline and 4 weeks after IA....... Conclusion. In contrast to the clinical evaluation, imaging measures of relevance for the estimation of inflammation, US-Doppler, US RI, MRI synovitis, and bone-marrow edema did not change 4 weeks after a single IA injection of either methylprednisolone or etanercept in the wrist. Within the same period...... target joint score (p 4 weeks. Baseline MRI synovitis score was mean 5.08 (range 3-9) and was unchanged at followup in the whole group (p = 0.52) and between treatment groups (p = 0.43). MRI edema score (mean 4.46, range 0...

  14. Analysis of a four-mirror-cavity enhanced Michelson interferometer.

    Science.gov (United States)

    Thüring, André; Lück, Harald; Danzmann, Karsten

    2005-12-01

    We investigate the shot-noise-limited sensitivity of a four-mirror-cavity enhanced Michelson interferometer. The intention of this interferometer topology is the reduction of thermal lensing and the impact of the interferometers contrast although transmissive optics are used with high circulating powers. The analytical expressions describing the light fields and the frequency response are derived. Although the parameter space has 11 dimensions, a detailed analysis of the resonance feature gives boundary conditions allowing systematic parameter studies.

  15. Phase correction for a Michelson interferometer with misaligned mirrors

    Science.gov (United States)

    Goorvitch, D.

    1975-01-01

    The phase correction for a Michelson interferometer with misaligned mirrors in converging light is shown to give rise to a quadratic phase shift. In general, the calculation of a spectrum from the measured interferogram needs phase correction. Phase corrections have been well worked out for the cases of a linear phase shift and a phase that is slowly varying. The standard procedures for correcting calculated spectra need to be modified, however, to remove any phase errors resulting from misaligned mirrors.

  16. Infrared spectra of lunar soils. [using a Michelson interferometer

    Science.gov (United States)

    Aronson, J. R.; Emslie, A. G.; Smith, E. M.

    1979-01-01

    Measured data obtained by Michelson interferometer spectrometer were stored in a computer file and smoothed by being passed forward and backward through a digital four-pole low pass filter. Infrared spectra of the 10 lunar samples are presented in the format of brightness temperature versus frequency. The mol % of feldspar, pyroxene, olivine, ilmenite and ferromagnetic silicate in each sample is presented in tables. The reflectance spectra of ilmenite and enstatite are shown in graphs.

  17. Two-photon quantum interference in a Michelson interferometer

    International Nuclear Information System (INIS)

    Odate, Satoru; Wang Haibo; Kobayashi, Takayoshi

    2005-01-01

    We have observed two-photon quantum interference in a Michelson interferometer. For the first time, we experimentally demonstrated two-photon quantum interference patterns, which show the transition from nonsubwavelength interference fringes to the general subwavelength interference. At the same time, a photon bunching effect was also shown by a postselection. The |1, 1> state with a single photon in a mode corresponding to each arm of the interferometer was exclusively postselected by using path difference between two arms

  18. Fiber inline Michelson interferometer fabricated by a femtosecond laser.

    Science.gov (United States)

    Yuan, Lei; Wei, Tao; Han, Qun; Wang, Hanzheng; Huang, Jie; Jiang, Lan; Xiao, Hai

    2012-11-01

    A fiber inline Michelson interferometer was fabricated by micromachining a step structure at the tip of a single-mode optical fiber using a femtosecond laser. The step structure splits the fiber core into two reflection paths and produces an interference signal. A fringe visibility of 18 dB was achieved. Temperature sensing up to 1000°C was demonstrated using the fabricated assembly-free device.

  19. OCT angiography and Color Doppler Imaging in the study of hemoperfusion in the retina and optic nerve in POAG

    Directory of Open Access Journals (Sweden)

    N. I. Kurysheva

    2016-01-01

    Full Text Available Purpose: To evaluate the hemoperfusion of Optic Nerve Disk (OND, peripapillary and macular areas, and retrobulbar blood flow in patients with primary open-angle glaucoma using optical coherence tomography with angiography (OCT-A and Сolor Doppler Imaging (CDI.Patients and Methods: 65 eyes of patients with primary open angle glaucoma (POAG and 22 eyes of age-matched healthy subjects were examined using the SD-OCT-А (RtVue xR Avanti with the AngioVue software. Retinal Thickness and Angio Flow Density (AFD were measured. AFD Disc and Peripapillary Flow Density were measured in OND and in peripapillary area. AFD Retina were evaluated in Macula inсluding Fovea- and Parafovea regions (superficial and deep of the inner retinal layers. Ophthalmic Artery (OA, Central Retinal Artery (CRA, Posterior short Ciliary Arteries (PCA, Central Retinal Vein (CRV and Vortex Vein (VV were measured by CDI. Statistical analysis was performed using SPSS version 21 and MASS library of language R. The value of each diagnostic indicator (z-value was calculated with the Wilcoxon-Mann-Whitney test and the area under the receiver operating characteristic curve (AUC.Results: Both OCT-A and CDI indicators were reduced in glaucoma compared to healthy eyes. The following indicators had the largest AUC and diagnostic value (z-value to discriminate the early glaucoma from normal eyes: AFD Retina Superficial Whole En Face (z = 3,83, p<0,0001; AUC 0,8 (0,69‑0,90, AFD Retina Deep Whole En Face (z = 3,31, p = 0,0007; AUC 0,76 (0,64‑0,88, Peripapillary Vessel Density (z = 3,2, p = 0,001; AUC 0,75 (0,63‑0,87, end-diastolic flow velocity in AO (z = 3,03, p = 0,002; AUC 0,74 (0,61‑0,86 and in TPCA (z = 2,78, p = 0,005; AUC 0,72 (0,58‑0,86; and to discriminate the early glaucoma from the advanced and far advanced stages: AFD Disc Peripapillary Inferior Temporalis (z = 5,61, p<0,0001; AUC 0,94 (0,86‑1,0 and the mean flow velocity in the CRA (z = 4,16, p<0

  20. The Michelson Era in American Science, 1870--1930

    International Nuclear Information System (INIS)

    Goldberg, S.; Stuewer, R.H.

    1988-01-01

    The articles in this volume relate, in one way or another, to a single experiment: the Michelson-Morley ether-drift experiment of 1887. About one-half of the articles in the collection are based on papers delivered at a two-day symposium ''The Michelson Era in American Science: 1870--1930,'' held a Case Western Reserve University in Cleveland, Ohio, 28--29 October 1987, commemorating the centennial of the experiment. The Michelson-Morley experiment was designed to detect the motion of the earth through the luminiferous ether. At the time, physicists did not question the existence of the ether. The experiment, like many physical probes of nature, was simple in conception, yet uncompromisingly demanding of the art of contemporary craftsmanship. The state of the mechanical arts and its relationship to the pursuit of physical science in late nineteenth- century America is well documented in Section I, which also addresses the more general question of the link between state-of-the-art shop practice and engineering theory

  1. Optical displacement measurement with GaAs/AlGaAs-based monolithically integrated Michelson interferometers

    OpenAIRE

    Hofstetter, Daniel; Zappe, H. P.; Dändliker, René

    2008-01-01

    Two monolithically integrated optical displacement sensors fabricated in the GaAs/AlGaAs material system are reported. These single-chip microsystems are configured as Michelson interferometers and comprise a distributed Bragg reflector (DBR) laser, photodetectors, phase shifters, and waveguide couplers. While the use of a single Michelson interferometer allows measurement of displacement magnitude only, a double Michelson interferometer with two interferometer signals in phase quadrature als...

  2. Utility of Tissue Doppler Imaging in the Echocardiographic Evaluation of Left and Right Ventricular Function in Dogs with Myxomatous Mitral Valve Disease with or without Pulmonary Hypertension.

    Science.gov (United States)

    Baron Toaldo, M; Poser, H; Menciotti, G; Battaia, S; Contiero, B; Cipone, M; Diana, A; Mazzotta, E; Guglielmini, C

    2016-05-01

    In human medicine, right ventricular (RV) functional parameters represent a tool for risk stratification in patients with congestive heart failure caused by left heart disease. Little is known about RV alterations in dogs with left-sided cardiac disorders. To assess RV and left ventricular (LV) function in dogs with myxomatous mitral valve disease (MMVD) with or without pulmonary hypertension (PH). One-hundred and fourteen dogs: 28 healthy controls and 86 dogs with MMVD at different stages. Prospective observational study. Animals were classified as healthy or having MMVD at different stages of severity and according to presence or absence of PH. Twenty-eight morphological, echo-Doppler, and tissue Doppler imaging (TDI) variables were measured and comparison among groups and correlations between LV and RV parameters were studied. No differences were found among groups regarding RV echo-Doppler and TDI variables. Sixteen significant correlations were found between RV TDI and left heart echocardiographic variables. Dogs with PH had significantly higher transmitral E wave peak velocity and higher E/e' ratio of septal (sMV) and lateral (pMV) mitral annulus. These 2 variables were found to predict presence of PH with a sensitivity of 84 and 72%, and a specificity of 71 and 80% at cut-off values of 10 and 9.33 for sMV E/e' and pMV E/e', respectively. No association between variables of RV function and different MMVD stage and severity of PH could be detected. Some relationships were found between echocardiographic variables of right and left ventricular function. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  3. Prognostic Value of Cardiac Time Intervals by Tissue Doppler Imaging M-Mode in Patients With Acute ST-Segment-Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; Søgaard, Peter

    2013-01-01

    Background- Color tissue Doppler imaging M-mode through the mitral leaflet is an easy and precise method to estimate all cardiac time intervals from 1 cardiac cycle and thereby obtain the myocardial performance index (MPI). However, the prognostic value of the cardiac time intervals and the MPI...... assessed by color tissue Doppler imaging M-mode through the mitral leaflet in patients with ST-segment-elevation myocardial infarction (MI) is unknown. Methods and Results- In total, 391 patients were admitted with an ST-segment-elevation MI, treated with primary percutaneous coronary intervention...

  4. Concordance and reproducibility between M-mode, tissue Doppler imaging, and two-dimensional strain imaging in the assessment of mitral annular displacement and velocity in patients with various heart conditions

    DEFF Research Database (Denmark)

    de Knegt, Martina Chantal; Biering-Sorensen, Tor; Sogaard, Peter

    2014-01-01

    AIMS: Mitral annular (MA) displacement reflects longitudinal left ventricular (LV) deformation and systolic velocity measurements reflect the rate of contraction; both are valuable in the diagnosis and prognosis of cardiac disease. The aim of this study was to test the agreement and reproducibility...... between motion mode (M-mode), colour tissue Doppler imaging (TDI), and two-dimensional strain imaging (2DSI) when measuring MA displacement and systolic velocity. METHODS AND RESULTS: Using GE Healthcare Vivid 7 and E9 and Echopac BT11 software, MA displacement and velocity measurements by 2DSI, TDI...

  5. Development of Michelson interferometer based spatial phase-shift digital shearography

    Science.gov (United States)

    Xie, Xin

    Digital shearography is a non-contact, full field, optical measurement method, which has the capability of directly measuring the gradient of deformation. For high measurement sensitivity, phase evaluation method has to be introduced into digital shearography by phase-shift technique. Catalog by phase-shift method, digital phase-shift shearography can be divided into Temporal Phase-Shift Digital Shearography (TPS-DS) and Spatial Phase-Shift Digital Shearography (SPS-DS). TPS-DS is the most widely used phase-shift shearography system, due to its simple algorithm, easy operation and good phase-map quality. However, the application of TPS-DS is only limited in static/step-by-step loading measurement situation, due to its multi-step shifting process. In order to measure the strain under dynamic/continuous loading situation, a SPS-DS system has to be developed. This dissertation aims to develop a series of Michelson Interferometer based SPS-DS measurement methods to achieve the strain measurement by using only a single pair of speckle pattern images. The Michelson Interferometer based SPS-DS systems utilize special designed optical setup to introduce extra carrier frequency into the laser wavefront. The phase information corresponds to the strain field can be separated on the Fourier domain using a Fourier Transform and can further be evaluated with a Windowed Inverse Fourier Transform. With different optical setups and carrier frequency arrangements, the Michelson Interferometer based SPS-DS method is capable to achieve a variety of measurement tasks using only single pair of speckle pattern images. Catalog by the aimed measurand, these capable measurement tasks can be divided into five categories: 1) measurement of out-of-plane strain field with small shearing amount; 2) measurement of relative out-of-plane deformation field with big shearing amount; 3) simultaneous measurement of relative out-of-plane deformation field and deformation gradient field by using multiple

  6. Prognostic value of systolic mitral annular velocity measured with Doppler tissue imaging in patients with chronic heart failure caused by left ventricular systolic dysfunction

    Science.gov (United States)

    Nikitin, N P; Loh, P H; de Silva, R; Ghosh, J; Khaleva, O Y; Goode, K; Rigby, A S; Alamgir, F; Clark, A L; Cleland, J G F

    2006-01-01

    Objective To assess the prognostic value of various conventional and novel echocardiographic indices in patients with chronic heart failure (CHF) caused by left ventricular (LV) systolic dysfunction. Methods 185 patients with a mean (SD) age of 67 (11) years with CHF and LV ejection fraction < 45% despite optimal pharmacological treatment were prospectively enrolled. The patients underwent two dimensional echocardiography with tissue harmonic imaging to assess global LV systolic function and obtain volumetric data. Transmitral flow was assessed with conventional pulse wave Doppler. Systolic (Sm), early, and late diastolic mitral annular velocities were measured with the use of colour coded Doppler tissue imaging. Results During a median follow up of 32 months (range 24–38 months in survivors), 34 patients died and one underwent heart transplantation. Sm velocity (hazard ratio (HR) 0.648, 95% confidence interval (CI) 0.463 to 0.907, p  =  0.011), diastolic arterial pressure (HR 0.965, 95% CI 0.938 to 0.993, p  =  0.015), serum creatinine (HR 1.006, 95% CI 1.001 to 1.011, p  =  0.023), LV ejection fraction (HR 0.945, 95% CI 0.899 to 0.992, p  =  0.024), age (HR 1.035, 95% CI 1.000 to 1.071, p  =  0.052), LV end systolic volume index (HR 1.009, 95% CI 0.999 to 1.019, p  =  0.067), and restrictive pattern of transmitral flow (HR 0.543, 95% CI 0.278 to 1.061, p  =  0.074) predicted the outcome of death or transplantation on univariate analysis. On multivariate analysis, only Sm velocity (HR 0.648, 95% CI 0.460 to 0.912, p  =  0.013) and diastolic arterial pressure (HR 0.966, 95% CI 0.938 to 0.994, p  =  0.016) emerged as independent predictors of outcome. Conclusions In patients with CHF and LV systolic dysfunction despite optimal pharmacological treatment, the strongest independent echocardiographic predictor of prognosis was Sm velocity measured with quantitative colour coded Doppler tissue

  7. Fiber-optic Michelson interferometer fixed in a tilted tube for direction-dependent ultrasonic detection

    Science.gov (United States)

    Gang, Tingting; Hu, Manli; Qiao, Xueguang; Li, JiaCheng; Shao, Zhihua; Tong, Rongxin; Rong, Qiangzhou

    2017-01-01

    A fiber-optic interferometer is proposed and demonstrated experimentally for ultrasonic detection. The sensor consists of a compact Michelson interferometer (MI), which is fixed in a tilted-tube end-face (45°). Thin gold films are used for the reflective coatings of two arms and one of the interference arms is etched serving as the sensing arm. The spectral sideband filter technique is used to interrogate the continuous and pulse ultrasonic signals (with frequency of 300 KHz). Furthermore, because of the asymmetrical structure of the sensor, it presents strong direction-dependent ultrasonic sensitivity, such that the sensor can be considered a vector detector. The experimental results show that the sensor is highly sensitive to ultrasonic signals, and thus it can be a candidate for ultrasonic imaging of seismic physical models.

  8. 4-D flow magnetic resonance imaging: blood flow quantification compared to 2-D phase-contrast magnetic resonance imaging and Doppler echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Gabbour, Maya [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Schnell, Susanne [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Jarvis, Kelly [Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Robinson, Joshua D. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Pediatrics, Division of Pediatric Cardiology, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Pediatrics, Chicago, IL (United States); Markl, Michael [Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States); Northwestern University, Department of Biomedical Engineering, McCormick School of Engineering, Evanston, IL (United States); Rigsby, Cynthia K. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging 9, Chicago, IL (United States); Northwestern University Feinberg School of Medicine, Department of Radiology, Chicago, IL (United States)

    2015-06-15

    Doppler echocardiography (echo) is the reference standard for blood flow velocity analysis, and two-dimensional (2-D) phase-contrast magnetic resonance imaging (MRI) is considered the reference standard for quantitative blood flow assessment. However, both clinical standard-of-care techniques are limited by 2-D acquisitions and single-direction velocity encoding and may make them inadequate to assess the complex three-dimensional hemodynamics seen in congenital heart disease. Four-dimensional flow MRI (4-D flow) enables qualitative and quantitative analysis of complex blood flow in the heart and great arteries. The objectives of this study are to compare 4-D flow with 2-D phase-contrast MRI for quantification of aortic and pulmonary flow and to evaluate the advantage of 4-D flow-based volumetric flow analysis compared to 2-D phase-contrast MRI and echo for peak velocity assessment in children and young adults. Two-dimensional phase-contrast MRI of the aortic root, main pulmonary artery (MPA), and right and left pulmonary arteries (RPA, LPA) and 4-D flow with volumetric coverage of the aorta and pulmonary arteries were performed in 50 patients (mean age: 13.1 ± 6.4 years). Four-dimensional flow analyses included calculation of net flow and regurgitant fraction with 4-D flow analysis planes similarly positioned to 2-D planes. In addition, 4-D flow volumetric assessment of aortic root/ascending aorta and MPA peak velocities was performed and compared to 2-D phase-contrast MRI and echo. Excellent correlation and agreement were found between 2-D phase-contrast MRI and 4-D flow for net flow (r = 0.97, P < 0.001) and excellent correlation with good agreement was found for regurgitant fraction (r = 0.88, P < 0.001) in all vessels. Two-dimensional phase-contrast MRI significantly underestimated aortic (P = 0.032) and MPA (P < 0.001) peak velocities compared to echo, while volumetric 4-D flow analysis resulted in higher (aortic: P = 0.001) or similar (MPA: P = 0.98) peak

  9. Estimation of left ventricular end diastolic pressure by tissue doppler imaging in patients with acute myocardial infarction

    International Nuclear Information System (INIS)

    Ali, M.; Abid, A.R.; Rehman, T.A.; Masood, A.; Sohail, S.

    2010-01-01

    Objective: To evaluate sensitivity and specificity of E / Ea > 10 for prediction of LVEDP > 15 mmHg in patients with coronary artery disease undergoing left heart catheterization. Materials and Methods: Sixty patients of acute transmural myocardial infarction at Jinnah Hospital Lahore were enrolled in study from December 2008 to December 2009. Patients with sinus rhythm were included in the study. Patients with valvular heart disease, complete right/left bundle branch block, Pacemaker dependence, Atrial fibrillation and Post mitral valve replacement were excluded. All patients were examined by performing trans thoracic Doppler echocardiography. The trans-mitral LV filling signal was traced manually and the following variables were obtained: peak early (E) and late (A) trans-mitral velocities, and E/A ratio. Tissue - Doppler derived indices were recorded at the lateral mitral annulus. These indices included systolic velocities (S'), early diastolic (Ea) velocities and late diastolic (Aa) velocities. Finally, the dimensionless index of E/Ea was calculated. All were averaged from at least three beats. Cardiac catheterization was performed via trans-femoral / trasradial route using six French (6F) sheaths. Left ventricular diastolic pressure was directly measured by fluid filled pigtail catheter attached to a pressure transducer. Results: Mean age of the study population was 56.8 +- 12.7 years. There were 47 (78.3%) males and 13 (21.7%) females. Diabetes mellitus was present in 12(20%), hypertension in 32 (53.3%), smoking in 35 (58.3%), dyslipidemia in 24 (40%). Anterior wall myocardial infarction occurred in 44 (73.3%) and inferior wall MI in 16 (26.7%). Grade I diastolic dysfunction was present in 22 (36.7%), Grade II in 31 (51.7%) and Grade III in 7 (11.7%) patients. E/E 15 in 9 (15%). Overall 21 patients were true positive, 6 were false positive, 25 were true negative and 8 were false negative. By applying 2 X 2 table sensitivity was 77.7%, specificity was 80

  10. Estimation of left ventricular end diastolic pressure by tissue doppler imaging in patients with acute myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Ali, M; Abid, A R; Rehman, T A; Masood, A; Sohail, S [Allama Iqbal Medical College/Jinnah Hospital, Lahore(Pakistan)

    2010-10-15

    Objective: To evaluate sensitivity and specificity of E / Ea > 10 for prediction of LVEDP > 15 mmHg in patients with coronary artery disease undergoing left heart catheterization. Materials and Methods: Sixty patients of acute transmural myocardial infarction at Jinnah Hospital Lahore were enrolled in study from December 2008 to December 2009. Patients with sinus rhythm were included in the study. Patients with valvular heart disease, complete right/left bundle branch block, Pacemaker dependence, Atrial fibrillation and Post mitral valve replacement were excluded. All patients were examined by performing trans thoracic Doppler echocardiography. The trans-mitral LV filling signal was traced manually and the following variables were obtained: peak early (E) and late (A) trans-mitral velocities, and E/A ratio. Tissue - Doppler derived indices were recorded at the lateral mitral annulus. These indices included systolic velocities (S'), early diastolic (Ea) velocities and late diastolic (Aa) velocities. Finally, the dimensionless index of E/Ea was calculated. All were averaged from at least three beats. Cardiac catheterization was performed via trans-femoral / trasradial route using six French (6F) sheaths. Left ventricular diastolic pressure was directly measured by fluid filled pigtail catheter attached to a pressure transducer. Results: Mean age of the study population was 56.8 +- 12.7 years. There were 47 (78.3%) males and 13 (21.7%) females. Diabetes mellitus was present in 12(20%), hypertension in 32 (53.3%), smoking in 35 (58.3%), dyslipidemia in 24 (40%). Anterior wall myocardial infarction occurred in 44 (73.3%) and inferior wall MI in 16 (26.7%). Grade I diastolic dysfunction was present in 22 (36.7%), Grade II in 31 (51.7%) and Grade III in 7 (11.7%) patients. E/E < 10 was observed in 31 (51.7%), 11 - 15 in 20 (33.3%) and > 15 in 9 (15%). Overall 21 patients were true positive, 6 were false positive, 25 were true negative and 8 were false negative. By

  11. The development of a combined b-mode, ARFI, and spectral Doppler ultrasound imaging system for investigating cardiovascular stiffness and hemodynamics

    Science.gov (United States)

    Doherty, Joshua R.; Dumont, Douglas M.; Trahey, Gregg E.

    2011-03-01

    The progression of atherosclerotic disease, caused by the formation of plaques within arteries, is a complex process believed to be a function of the localized mechanical properties and hemodynamic loading associated with the arterial wall. It is hypothesized that measurements of vascular stiffness and wall-shear rate (WSR) may provide important information regarding vascular remodeling, endothelial function, and the growth of soft-lipid filled plaques that could help a clinician better diagnose a patient's risk of clinical events such as stroke. To that end, the approach taken in this work was to combine conventional B-mode, Acoustic Radiation Force Impulse (ARFI), Shear Wave Elasticity Imaging (SWEI), and spectral Doppler techniques into a single imaging system capable of simultaneously measuring the tissue displacements and WSR throughout the cardiac cycle and over several heartbeats. Implemented on a conventional scanner, the carotid arteries of human subjects were scanned to demonstrate the initial in vivo feasibility of the method. Two non-invasive ultrasound based imaging methods, SAD-SWEI and SAD-Gated Imaging, were developed that measure ARF-induced on-axis tissue displacements, off-axis transverse wave velocities, and WSR throughout the cardiac cycle. Human carotid artery scans were performed in vivo on 5 healthy subjects. Statistical differences were observed in both on-axis proximal wall displacements and transverse wave velocities during diastole compared to systole.

  12. Comparison of three techniques for evaluating skin erythemal response for determination of sun protection factors of sunscreens: high resolution laser Doppler imaging, colorimetry and visual scoring.

    Science.gov (United States)

    Wilhelm, K P; Kaspar, K; Funkel, O

    2001-04-01

    Sun protection factor (SPF) measurement is based on the determination of the minimal erythema dose (MED). The ratio of doses required to induce a minimal erythema between product-treated and untreated skin is defined as SPF. The aim of this study was to validate the conventionally used visual scoring with two non-invasive methods: high resolution laser Doppler imaging (HR-LDI) and colorimetry. Another goal was to check whether suberythemal reactions could be detected by means of HR-LDI measurements. Four sunscreens were selected. The measurements were made on the back of 10 subjects. A solar simulator SU 5000 (m.u.t., Wedel, Germany) served as radiation source. For the visual assessment, the erythema was defined according to COLIPA as the first perceptible, clearly defined unambiguous redness of the skin. For the colorimetric determination of the erythema, a Chromameter CR 300 (Minolta, Osaka, Japan) was used. The threshold for the colorimetry was chosen according to the COLIPA recommendation as an increase of the redness parameter delta a* = 2.5. For the non-contact perfusion measurements of skin blood flow, a two-dimensional high resolution laser Doppler imager (HR-LDI) (Lisca, Linköping, Sweden) was used. For the HR-LDI measurements, an optimal threshold perfusion needed to be established. For the HR-LDI measurements basal perfusion +1 standard deviation of all basal measurements was found to be a reliable threshold perfusion corresponding to the minimal erythema. Smaller thresholds, which would be necessary for detection of suberythemal responses, did not provide unambiguous data. All three methods, visual scoring, colorimetry and HR-LDI, produced similar SPFs for the test products with a variability of colorimetry are suitable, reliable and observer-independent methods for MED determination. However, they do not provide greater sensitivity and thus do not result in lower UV dose requirements for testing.

  13. Measurement of periodically varying ECE spectra using a Michelson interferometer

    International Nuclear Information System (INIS)

    Laurent, L.; Rodriguez, L.; Talvard, M.

    1987-01-01

    In some tokamak experiments the ECE spectrum is periodically varying. If the modulation frequency is small enough (less than 10 Hz) the plasma can be considered as quasi-stationary during the typical scan time of most of the Michelson interferometers. It is possible to measure simply ECE spectra at different times of the oscillation. We present here a technique which allows to measure smaller fluctuations at larger frequencies. However the analysis requires a large number of periods of oscillation at constant frequency and a scanning mirror moving at constant velocity

  14. Special relativity and the Michelson-Morley experiment

    International Nuclear Information System (INIS)

    Chapman, B.R.

    1979-01-01

    It is stated that contrary to most textbook statements about the origins of relativity, there is no real evidence to support the existence of a causal relationship between Michelson's 'crucial' experiment on ether drift and Einstein's enunciation of special relativity. Selective but, it is believed by the author, representative evidence elating to the genesis of the theory of special relativity is presented. Since this evidence contradicts both the substance and the spirit of most textbook references to that genesis, it is thought by the author to have some pedagogic significance for those attempting to teach both the process and the content of physics. (U.K.)

  15. Superposition of helical beams by using a Michelson interferometer.

    Science.gov (United States)

    Gao, Chunqing; Qi, Xiaoqing; Liu, Yidong; Weber, Horst

    2010-01-04

    Orbital angular momentum (OAM) of a helical beam is of great interests in the high density optical communication due to its infinite number of eigen-states. In this paper, an experimental setup is realized to the information encoding and decoding on the OAM eigen-states. A hologram designed by the iterative method is used to generate the helical beams, and a Michelson interferometer with two Porro prisms is used for the superposition of two helical beams. The experimental results of the collinear superposition of helical beams and their OAM eigen-states detection are presented.

  16. Modulation depth of Michelson interferometer with Gaussian beam.

    Science.gov (United States)

    Välikylä, Tuomas; Kauppinen, Jyrki

    2011-12-20

    Mirror misalignment or the tilt angle of the Michelson interferometer can be estimated from the modulation depth measured with collimated monochromatic light. The intensity of the light beam is usually assumed to be uniform, but, for example, with gas lasers it generally has a Gaussian distribution, which makes the modulation depth less sensitive to the tilt angle. With this assumption, the tilt angle may be underestimated by about 50%. We have derived a mathematical model for modulation depth with a circular aperture and Gaussian beam. The model reduces the error of the tilt angle estimate to below 1%. The results of the model have been verified experimentally.

  17. Analysis of the Localization of Michelson Interferometer Fringes Using Fourier Optics and Temporal Coherence

    Science.gov (United States)

    Narayanamurthy, C. S.

    2009-01-01

    Fringes formed in a Michelson interferometer never localize in any plane, in the detector plane and in the localization plane. Instead, the fringes are assumed to localize at infinity. Except for some explanation in "Principles of Optics" by Born and Wolf (1964 (New York: Macmillan)), the fringe localization phenomena of Michelson's interferometer…

  18. Maurice Car̊me'i lihtsad laulud lastele / Helle Michelson

    Index Scriptorium Estoniae

    Michelson, Helle, 1929-

    2003-01-01

    Car̊me, Maurice. Muinasjutud Caprine'ile / tõlkinud Helle Michelson. [Tallinn] : Tiritamm, 2002 ; Car̊me, Maurice. Naeruhull kirsipuu : [luuletused] / prantsuse keelest tõlkinud Helvi Jürisson. [Tallinn] : Tiritamm, 2002 ; Car̊me, Maurice. Margareetapäev : [jutustused] / tõlkinud Helle Michelson. [Tallinn] : Varrak, 2000

  19. Comparison of optical and power Doppler ultrasound imaging for non-invasive evaluation of arsenic trioxide as a vascular disrupting agent in tumors.

    Science.gov (United States)

    Alhasan, Mustafa K; Liu, Li; Lewis, Matthew A; Magnusson, Jennifer; Mason, Ralph P

    2012-01-01

    Small animal imaging provides diverse methods for evaluating tumor growth and acute response to therapy. This study compared the utility of non-invasive optical and ultrasound imaging to monitor growth of three diverse human tumor xenografts (brain U87-luc-mCherry, mammary MCF7-luc-mCherry, and prostate PC3-luc) growing in nude mice. Bioluminescence imaging (BLI), fluorescence imaging (FLI), and Power Doppler ultrasound (PD US) were then applied to examine acute vascular disruption following administration of arsenic trioxide (ATO).During initial tumor growth, strong correlations were found between manual caliper measured tumor volume and FLI intensity, BLI intensity following luciferin injection, and traditional B-mode US. Administration of ATO to established U87 tumors caused significant vascular shutdown within 2 hrs at all doses in the range 5 to 10 mg/kg in a dose dependant manner, as revealed by depressed bioluminescent light emission. At lower doses substantial recovery was seen within 4 hrs. At 8 mg/kg there was >85% reduction in tumor vascular perfusion, which remained depressed after 6 hrs, but showed some recovery after 24 hrs. Similar response was observed in MCF7 and PC3 tumors. Dynamic BLI and PD US each showed similar duration and percent reductions in tumor blood flow, but FLI showed no significant changes during the first 24 hrs.The results provide further evidence for comparable utility of optical and ultrasound imaging for monitoring tumor growth, More specifically, they confirm the utility of BLI and ultrasound imaging as facile assays of the vascular disruption in solid tumors based on ATO as a model agent.

  20. Are microbubbles free flowing tracers through the Myocardium? Comparison of indicator-dilution curves obtained from dye dilution and echo contrast using harmonic power Doppler imaging.

    Science.gov (United States)

    Tiemann, K; Schlosser, T; Pohl, C; Bimmel, D; Wietasch, G; Hoeft, A; Likungu, J; Vahlhaus, C; Kuntz, S; Nanda, N C; Becher, H; Lüderitz, B

    2000-01-01

    Harmonic power Doppler imaging (H-PDI) has been introduced into the field of contrast echocardiography as a contrast-specific imaging modality. However, there has been considerable skepticism as to whether H-PDI would be quantifiable, because it depends on the destruction of microbubbles and has more complex signal processing than gray scale imaging. The aim of the present study was to evaluate the relationship between the concentration of microbubbles and the resulting H-PDI signals even under conditions where bubble destruction is most likely. Furthermore, we evaluated whether microbubbles of Levovist freely pass the microcirculation, which is a prerequisite for the assessment of myocardial blood flow. A strong positive correlation was found between the H-PDI signals and the amount of microbubbles up to the onset of acoustic shadowing (r = 0. 968, Pgreen (ICG) in both a flow phantom and a working heart setup. The mean transit times (MTTs) through the myocardium of both agents were compared after a bolus injection into the left coronary artery. A close correlation was observed between 1/MTT and flow in both setups (r>0.98, Pgreen. We conclude that microbubbles fulfill the prerequisites of free flowing tracers through the myocardium. Furthermore, H-PDI technology allows a reliable assessment of time-concentration curves of air-filled microbubbles up to the onset of acoustic shadowing.

  1. Comparative Analysis of Logistic Regression, Support Vector Machine and Artificial Neural Network for the Differential Diagnosis of Benign and Malignant Solid Breast Tumors by the Use of Three-Dimensional Power Doppler Imaging

    International Nuclear Information System (INIS)

    Chen, Shou Tung; Hsiao, Yi Hsuan; Kuo, Shou Jen; Tseng, Hsin Shun; Wu, Hwa Koon; Chen, Dar Ren; Huang, Yu Len

    2009-01-01

    Logistic regression analysis (LRA), Support Vector Machine (SVM) and a neural network (NN) are commonly used statistical models in computeraided diagnostic (CAD) systems for breast ultrasonography (US). The aim of this study was to clarify the diagnostic ability of the use of these statistical models for future applications of CAD systems, such as three-dimensional (3D) power Doppler imaging, vascularity evaluation and the differentiation of a solid mass. A database that contained 3D power Doppler imaging pairs of non-harmonic and tissue harmonic images for 97 benign and 86 malignant solid tumors was utilized. The virtual organ computer-aided analysis-imaging program was used to analyze the stored volumes of the 183 solid breast tumors. LRA, an SVM and NN were employed in comparative analyses for the characterization of benign and malignant solid breast masses from the database. The values of area under receiver operating characteristic (ROC) curve, referred to as Az values for the use of non-harmonic 3D power Doppler US with LRA, SVM and NN were 0.9341, 0.9185 and 0.9086, respectively. The Az values for the use of harmonic 3D power Doppler US with LRA, SVM and NN were 0.9286, 0.8979 and 0.9009, respectively. The Az values of six ROC curves for the use of LRA, SVM and NN for non-harmonic or harmonic 3D power Doppler imaging were similar. The diagnostic performances of these three models (LRA, SVM and NN) are not different as demonstrated by ROC curve analysis. Depending on user emphasis for the use of ROC curve findings, the use of LRA appears to provide better sensitivity as compared to the other statistical models

  2. Quantitative phase determination by using a Michelson interferometer

    International Nuclear Information System (INIS)

    Pomarico, Juan A; Molina, Pablo F; Angelo, Cristian D'

    2007-01-01

    The Michelson interferometer is one of the best established tools for quantitative interferometric measurements. It has been, and is still successfully used, not only for scientific purposes, but it is also introduced in undergraduate courses for qualitative demonstrations as well as for quantitative determination of several properties such as refractive index, wavelength, optical thickness, etc. Generally speaking, most of the measurements are carried out by determining phase distortions through the changes in the location and/or shape of the interference fringes. However, the extreme sensitivity of this tool, for which minimum deviations of the conditions of its branches can cause very large modifications in the fringe pattern, makes phase changes difficult to follow and measure. The purpose of this communication is to show that, under certain conditions, the sensitivity of the Michelson interferometer can be 'turned down' allowing the quantitative measurement of phase changes with relative ease. As an example we present how the angle (or, optionally, the refractive index) of a transparent standard optical wedge can be determined. Experimental results are shown and compared with the data provided by the manufacturer showing very good agreement

  3. X-ray-ultraviolet beam splitters for the Michelson interferometer

    International Nuclear Information System (INIS)

    Delmotte, Franck; Ravet, Marie-Francoise; Bridou, Francoise; Varniere, Francoise; Zeitoun, Philippe; Hubert, Sebastien; Vanbostal, Laurent; Soullie, Gerard

    2002-01-01

    With the aim of realizing a Michelson interferometer working at 13.9 nm, we have developed a symmetrical beam splitter with multilayers deposited on the front and back sides of a silicon nitride membrane. On the basis of the experimental optical properties of the membrane, simulations have been performed to define the multilayer structure that provides the highest reflectivity-transmission product. Optimized Mo-Si multilayers have been successfully deposited on both sides of the membrane by use of the ion-beam sputtering technique, with a thickness-period reproducibility of 0.1 nm. Measurements by means of synchrotron radiation at 13.9 nm and at an angle of 45 deg. provide a reflectivity of 14.2% and a transmission of 15.2% for a 60% s-polarized light, close to the simulated values. Such a beam splitter has been used for x-ray laser Michelson interferometry at 13.9 nm. The first interferogram is discussed

  4. Development of stable monolithic wide-field Michelson interferometers.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian; Chen, Zhiping

    2011-07-20

    Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10(-6)/°C near 550 nm, which corresponds to ∼800 m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations. © 2011 Optical Society of America

  5. X-ray-ultraviolet beam splitters for the Michelson interferometer.

    Science.gov (United States)

    Delmotte, Franck; Ravet, Marie-Françoise; Bridou, Françoise; Varnière, Françoise; Zeitoun, Philippe; Hubert, Sébastien; Vanbostal, Laurent; Soullie, Gérard

    2002-10-01

    With the aim of realizing a Michelson interferometer working at 13.9 nm, we have developed a symmetrical beam splitter with multilayers deposited on the front and back sides of a silicon nitride membrane. On the basis of the experimental optical properties of the membrane, simulations have been performed to define the multilayer structure that provides the highest reflectivity-transmission product. Optimized Mo-Si multilayers have been successfully deposited on both sides of t he membrane by use of the ion-beam sputtering technique, with a thickness-period reproducibility of 0.1 nm. Measurements by means of synchrotron radiation at 13.9 nm and at an angle of 45 degrees provide a reflectivity of 14.2% and a transmission of 15.2% for a 60% s-polarized light, close to the simulated values. Such a beam splitter has been used for x-ray laser Michelson interferometry at 13.9 nm. The first interferogram is discussed.

  6. Laser Doppler velocimeter measurements and laser sheet imaging in an annular combustor model. M.S. Thesis, Final Report

    Science.gov (United States)

    Dwenger, Richard Dale

    1995-01-01

    An experimental study was conducted in annular combustor model to provide a better understanding of the flowfield. Combustor model configurations consisting of primary jets only, annular jets only, and a combination of annular and primary jets were investigated. The purpose of this research was to provide a better understanding of combustor flows and to provide a data base for comparison with computational models. The first part of this research used a laser Doppler velocimeter to measure mean velocity and statistically calculate root-mean-square velocity in two coordinate directions. From this data, one Reynolds shear stress component and a two-dimensional turbulent kinetic energy term was determined. Major features of the flowfield included recirculating flow, primary and annular jet interaction, and high turbulence. The most pronounced result from this data was the effect the primary jets had on the flowfield. The primary jets were seen to reduce flow asymmetries, create larger recirculation zones, and higher turbulence levels. The second part of this research used a technique called marker nephelometry to provide mean concentration values in the combustor. Results showed the flow to be very turbulent and unsteady. All configurations investigated were highly sensitive to alignment of the primary and annular jets in the model and inlet conditions. Any imbalance between primary jets or misalignment of the annular jets caused severe flow asymmetries.

  7. Clinical utility of eco-color-power Doppler ultrasonography and contrast enhanced magnetic resonance imaging for interpretation and quantification of joint synovitis: a review.

    Science.gov (United States)

    Carotti, Marina; Galeazzi, Vittoria; Catucci, Francesca; Zappia, Marcello; Arrigoni, Francesco; Barile, Antonio; Giovagnoni, Andrea

    2018-01-19

    With the introduction of new biologics such as anti-TNF-alpha antibodies and other therapies in the treatment of inflammatory arthritis, capable of halting joint destruction and functional disability, there are new pressures on diagnostic and prognostic imaging. Early demonstration of pre-erosive inflammatory features and monitoring of the long-term effects of treatment are becoming increasingly important. Early detection of synovitis offers advantages in terms of allowing early instigation of therapy and may allow the identification of those patients displaying more aggressive disease who might benefit from early intervention with expensive DMARD therapy. Advanced imaging techniques such as ultrasound (US) and magnetic resonance imaging (MRI) have focussed on the demonstration and quantification of synovitis and allow early diagnosis of inflammatory arthropathies such as rheumatoid arthritis (RA) and psoriatic arthritis (PsA). Synovitis represents a potential surrogate measure of disease activity that can be monitored using either MRI or US; the techniques have, generally, focused on monitoring synovial volume or quality as assessed by its vascularity. However to achieve these goals, standardisation and validation of US and MRI are required to ensure accurate diagnosis, reproducibility and reliability. Each modality has different strengths and weaknesses and levels of validation. This article aims to increase the awareness of radiologists and rheumatologists about this field and to encourage them to participate and contribute to the ongoing development of these modalities. Without this collaboration, it is unlikely that these modalities will reach their full potential in the field of rheumatological imaging. This review is in two parts. The first part addresses the role of US and colour or power Doppler sonography (PDUS) in the detection and monitoring of synovitis in inflammatory arthropathies. The second part will look at advanced MR imaging and Dynamic contrast

  8. Principles of doppler tomography

    International Nuclear Information System (INIS)

    Juhlin, P.

    1992-08-01

    This paper shows how the radon transform can be used to determine vector fields. A scheme to determine the velocity field of a moving fluid by measurements with a continuous doppler signal is suggested. When the flow is confined to a bounded domain, as is the case in most applications, it can be uniquely decomposed into one gradiental and one rotational part. The former vanishes if the fluid is incompressible and source-free, and the latter can be completely reconstructed by the methods proposed in this paper if the domain is simply connected. Special attention is paid to laminar flow in a long cylindrical vessel with circular cross-section. Under such conditions the flow profile becomes parabolic, which makes the vessel recognizable as a typical 'N-shaped' pattern in an image describing the rotation of the velocity field. The vessel yields the same doppler tomographic pattern, no matter how it is sectioned. The ideas presented should be applicable also when studying the flow in blood vessels, even if the flow profile in these is not quite parabolic. The discrepancies only make the 'N-shape' somewhat distorted

  9. Transvaginal color Doppler imaging of uterine contractions in early pregnancies: Significance of uterine contractions in early pregnancy failure

    International Nuclear Information System (INIS)

    Lee, Eun Ju; Han, Chang Jin; Suh, Jung Ho; Kwon, Hyuck Chan

    1999-01-01

    To assess uterine contractions in early pregnancies using transvaginal color Doppler sonography (TVCDS) and to determine the role of uterine contractions in the diagnosis of early pregnancy failure. 76 patients with abnormal pregnancy diagnosed by sonography or histopathology up to 10 weeks of gestation and 38 normal pregnant women as the control group were examines with TVCDS. The presence of uterine contractions was determined by complete or partial disappearance of the color flow signals of vessels within myometrium, and the direction, amplitude (grade 1-3), and interval of uterine contractions were also evaluated. Uterine contractions were identified in 42 (55.3%) of 76 patients with abnormal pregnancy, whereas they were detected only in 2 (5.3%) of 38 normal pregnant women who had initial grade 1 contraction but disappeared in the follow-up study. In 26 patients with blighted ovum or missed abortion, 15 patients (57.7%),showed uterine contraction of grade 1 in 3 cases, grade 2 in 8 cases, and grade 3 in 4 cases and interval from 45 seconds to 5 minutes. In 30 patients with inevitable or incomplete abortion, 23 patients (76.6%) showed uterine contraction of grade 1 in 2 cases, grade 2 in 9 cases, and grade 3 in 12 cases and interval from 1 to 5 minutes. 4 (20%) of 20 patients with threatened abortion had uterine contraction of grade 2 and interval from 2 to 4 minutes. The presence of uterine contractions was significantly different in abnormal pregnancies compared with that of normal and also among the tree different groups of abnormal pregnancies, but the amplitude did not differ.

  10. Transvaginal color Doppler imaging of uterine contractions in early pregnancies: Significance of uterine contractions in early pregnancy failure

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Ju; Han, Chang Jin; Suh, Jung Ho; Kwon, Hyuck Chan [Aju University SChool of Medicine, Suwon (Korea, Republic of)

    1999-06-15

    To assess uterine contractions in early pregnancies using transvaginal color Doppler sonography (TVCDS) and to determine the role of uterine contractions in the diagnosis of early pregnancy failure. 76 patients with abnormal pregnancy diagnosed by sonography or histopathology up to 10 weeks of gestation and 38 normal pregnant women as the control group were examines with TVCDS. The presence of uterine contractions was determined by complete or partial disappearance of the color flow signals of vessels within myometrium, and the direction, amplitude (grade 1-3), and interval of uterine contractions were also evaluated. Uterine contractions were identified in 42 (55.3%) of 76 patients with abnormal pregnancy, whereas they were detected only in 2 (5.3%) of 38 normal pregnant women who had initial grade 1 contraction but disappeared in the follow-up study. In 26 patients with blighted ovum or missed abortion, 15 patients (57.7%),showed uterine contraction of grade 1 in 3 cases, grade 2 in 8 cases, and grade 3 in 4 cases and interval from 45 seconds to 5 minutes. In 30 patients with inevitable or incomplete abortion, 23 patients (76.6%) showed uterine contraction of grade 1 in 2 cases, grade 2 in 9 cases, and grade 3 in 12 cases and interval from 1 to 5 minutes. 4 (20%) of 20 patients with threatened abortion had uterine contraction of grade 2 and interval from 2 to 4 minutes. The presence of uterine contractions was significantly different in abnormal pregnancies compared with that of normal and also among the tree different groups of abnormal pregnancies, but the amplitude did not differ.

  11. Noise Studies of Externally Dispersed Interferometry for Doppler Velocimetry

    International Nuclear Information System (INIS)

    Erskine, D J; Edelstein, J; Lloyd, J; Muirhead, P

    2006-01-01

    Externally Dispersed Interferometry (EDI) is the series combination of a fixed-delay field-widened Michelson interferometer with a dispersive spectrograph. This combination boosts the spectrograph performance for both Doppler velocimetry and high resolution spectroscopy. The interferometer creates a periodic comb that multiplies against the input spectrum to create moire fringes, which are recorded in combination with the regular spectrum. Both regular and high-frequency spectral components can be recovered from the data--the moire component carries additional information that increases the signal to noise for velocimetry and spectroscopy. Here we present simulations and theoretical studies of the photon limited Doppler velocity noise in an EDI. We used a model spectrum of a 1600K temperature star. For several rotational blurring velocities 0, 7.5, 15 and 25 km/s we calculated the dimensionless Doppler quality index (Q) versus wavenumber v. This is the normalized RMS of the derivative of the spectrum and is proportional to the photon-limited Doppler signal to noise ratio

  12. To assess the intimal thickness, flow velocities, and luminal diameter of carotid arteries using high-resolution B-mode ultrasound doppler imaging

    Science.gov (United States)

    Vemuru, Madhuri; Jabbar, Afzal; Chandra, Suman

    2004-04-01

    Carotid imaging is a Gold Standard test that provides useful information about the structure and functions of carotid arteries. Spectral imaging helps to evaluate the vessel and hemodynamic changes. High resolution B-mode imaging has emerged as one of the methods of choice for determining the anatomic extent of atherosclerosis and its progression and for assessing cardiovascular risks. The measurements made with Doppler correlate well with pathologic measurements. Recent prospective studies have clearly demonstrated that these measurements of carotid intimal thickness are potent predictors of Myocardial Infarction and Stroke. This method appears very attractive as it is non-invasive, extremely safe, well accepted by the patient and relatively inexpensive. It can be performed serially and has the advantage of visualizing the arterial wall in contrast to angiographic techniques which provide only an outline of the arterial lumen. Recently, there has been an interest in the clinical use of this technique in making difficult clinical decisions like deciding on preventive therapies. 30 subjects aged 21-60 years and 30 subjects aged 61-85 years of both sexes are selected after doing a baseline study to exclude Hypertension, Diabetes, Obesity and Hyperlipidemia. The carotid arteries were examined for intimal thickening, blood flow velocities and luminal diameter. With aging there is a narrowing of the carotid vessels and significant increase in intimal thickening with a consequent increase in the blood flow velocities. Inter-observer, intra-observer and instrument variations are seen and there is no significant change in the values when the distal flow pattern is considered for measurements. Aging produces major cardiovascular changes including decreased elasticity and compliance of great arteries leading to structural and functional alterations in heart and vessels. With aging there is increased intimal thickness and increased pulse wave velocity which is clearly

  13. Integrated fiber Michelson interferometer based on poled hollow twin-core fiber.

    Science.gov (United States)

    Liu, Zhihai; Bo, Fusen; Wang, Lei; Tian, Fengjun; Yuan, Libo

    2011-07-01

    We propose an integrated fiber Michelson interferometer based on a poled hollow twin-core fiber. The Michelson interferometer can be used as an electro-optic modulator by thermal poling one core of the twin-core fiber and introducing second-order nonlinearity in the fiber. The proposed fiber Michelson interferometer is experimentally demonstrated under driving voltages at the frequency range of 149 to 1000 Hz. The half-wave voltage of the poled fiber is 135 V, and the effective second-order nonlinear coefficient χ² is 1.23 pm/V.

  14. Development of high resolution Michelson interferometer for stable phase-locked ultrashort pulse pair generation.

    Science.gov (United States)

    Okada, Takumi; Komori, Kazuhiro; Goshima, Keishiro; Yamauchi, Shohgo; Morohashi, Isao; Sugaya, Takeyoshi; Ogura, Mutsuo; Tsurumachi, Noriaki

    2008-10-01

    We developed a high resolution Michelson interferometer with a two-frequency He-Ne laser positioning system in order to stabilize the relative phase of a pulse pair. The control resolution corresponded to a 12 as time resolution or a phase of 1.5 degrees at 900 nm. This high resolution Michelson interferometer can generate a phase-locked pulse pair either with a specific relative phase such as 0 or pi radians or with an arbitrary phase. Coherent control of an InAs self-assembled quantum dot was demonstrated using the high resolution Michelson interferometer with a microspectroscopy system.

  15. Realization of an efficient coherent combination via Michelson cavity

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An intracavity coherent coupling Michelson erbium-doped fibre (EDF) laser (MCEDFL) is proposed and demonstrated. By using this laser system, we find a means to obtain a maximum power output at the same pumping power level. From the experiment based on fibre Bragg gratings (FBGs) with different reflectivities from 6% to 100%, we find that the reflectivity of the FBG plays a vital role in improving the performance of the MCEDFL. At the same time, the MCEDFL with a polarizer can be coherently combined effectively. This type of system, in principle, is compatible with other more powerful pumping methods, such as cladding pumping, and brings some novel perspectives to the realization of high power lasers.

  16. Nanonewton force measurement using a modified Michelson interferometer

    International Nuclear Information System (INIS)

    Tahviliyan, Masoud; Charsooghi, Mohammad A; Akhlaghi, Ehsan A; Taghi Tavassoly, Mohammad

    2017-01-01

    In this paper, we introduce a new method to measure forces in the nanonewton range. The method is based on modification of a Michelson interferometer in which the rigid mirrors are replaced with two thin rod-like mirrors. One of the rod-like mirrors is fixed at both ends and the other has one free end. As the mirror with free end deflects in response to an applied force the spatial interference pattern is changed. Analysis of the interference fringes provides a readout of the rod deflection and thereby the applied force. The device is calibrated by applying known forces to the mirror with a free end and measuring the resulting displacement. Two different methods, mechanical and electrostatic, are used for calibration. The precision of the measurements and the propagation of the calibration uncertainty are investigated. The results show that this optical method is a good candidate for detecting small forces in the nanonewton range. (paper)

  17. A Michelson interferometer for X-rays and thermal neutrons

    International Nuclear Information System (INIS)

    Appel, A.

    1992-01-01

    The introduced interferometer consists of an LLL interferometer and a phase-displacing Bragg groove component. A part of the radiation path between the Lane mirrors in the Bragg grooves is replaced by a radiation path, whose wave number vector has a slightly different direction compared to the Lane case by the refraction correction. If the angles of incidence in the two grooves are different, then a difference in path is produced between the beams producing interference. This is the first X-ray interferometer which works like an optical Michelson interferometer. As there are no basic limits to resolution by absorption or dispersion, for example, it opens up the possibility of carrying out Fourier spectroscopy in the A wavelength range. (orig.) [de

  18. The Michelson interferometer-how to detect invisible interference patterns

    International Nuclear Information System (INIS)

    Verovnik, Ivo; Likar, Andrej

    2004-01-01

    In a Michelson interferometer, the contrast of the interference pattern fades away due to incoherence of light when the mirrors are not in equidistant positions. We propose an experiment where the distance between the interference fringes can be determined, even when the difference in length of the interferometer arms is far beyond the coherence length of the light, i.e. when the interference pattern disappears completely for the naked eye. We used a semiconductor laser with two photodiodes as sensors, which enabled us to follow the fluctuations of the light intensity on the screen. The distance between invisible interference fringes was determined from periodic changes of the summed fluctuating signal, obtained by changing the distance between the two sensors

  19. Investigation of michelson interferometer for volatile organic compound sensor

    International Nuclear Information System (INIS)

    Marzuarman; Rivai, Muhammad; Sardjono, Tri Arief; Purwanto, Djoko

    2017-01-01

    The sensor device is required to monitor harmful gases in the environments and industries. Many volatile organic compounds adsorbed on the sensor material will result in changes of the optical properties including the refractive index and the film thickness. This study designed and realized a vapor detection device using the principle of Michelson Interferometer. The laser light beamed with a wavelength of 620 nm was divided by using a beam splitter. Interference occurredwhen the two separated lights were recombined. The phase difference between the two beams determined whether the interference would destruct or construct each other to produce the curved fringes. The vapor samples used in these experiments were ethanol and benzene. The results showed that the ethanol concentration of 1611-32210 ppm produced a fringe shift of 197 pixels, while the concentration of benzene of 964-19290 ppm produced a fringe shift of 273 pixels. (paper)

  20. Dissipative optomechanics in a Michelson-Sagnac interferometer.

    Science.gov (United States)

    Xuereb, André; Schnabel, Roman; Hammerer, Klemens

    2011-11-18

    Dissipative optomechanics studies the coupling of the motion of an optical element to the decay rate of a cavity. We propose and theoretically explore a realization of this system in the optical domain, using a combined Michelson-Sagnac interferometer, which enables a strong and tunable dissipative coupling. Quantum interference in such a setup results in the suppression of the lower motional sideband, leading to strongly enhanced cooling in the non-sideband-resolved regime. With state-of-the-art parameters, ground-state cooling and low-power quantum-limited position transduction are both possible. The possibility of a strong, tunable dissipative coupling opens up a new route towards observation of such fundamental optomechanical effects as nonlinear dynamics. Beyond optomechanics, the suggested method can be readily transferred to other setups involving nonlinear media, atomic ensembles, or single atoms.

  1. The tempo-spatially modulated polarization atmosphere Michelson interferometer.

    Science.gov (United States)

    Zhang, ChunMin; Zhu, HuaChun; Zhao, Baochang

    2011-05-09

    A space-based tempo-spatially modulated polarization atmosphere Michelson interferometer (TSMPAMI) is described. It uses the relative movement between the TSMPAMI and the measured target to change optical path difference. The acquisition method of interferogram is presented. The atmospheric temperatures and horizontal winds can be derived from the optical observations. The measurement errors of the winds and temperatures are discussed through simulations. In the presence of small-scale structures of the atmospheric fields, the errors are found to be significantly influenced by the mismatch of the scenes observed by the adjacent CCD sub-areas aligned along the orbiter's track during successive measurements due to the orbital velocity and the exposure time. For most realistic conditions of the orbit and atmosphere, however, the instrument is proven suitable for measuring the atmospheric parameters. © 2011 Optical Society of America

  2. Patient-exposure data for doppler ultrasound

    International Nuclear Information System (INIS)

    Stewart, H.F.; Silvis, P.X.; Smith, S.W.

    1986-01-01

    In recent years ultrasound imaging and Doppler blood flow measurements have become important tools for use in diagnostic medicine. Commercial pulse-echo imaging equipment was first introduced into commerce in 1963. The first commercial continuous wave Doppler unit was introduced to the marketplace in 1966. As equipment improved and applications developed, the industry experienced rapid growth in the 1970s. One of the more recent growth areas in the application of diagnostic ultrasound has been the use of pulsed Doppler equipment for cardiac applications. Prior to 1976, some continuous wave Doppler ultrasound was used for cardiovascular diagnosis. However, only a single manufacturer marketed a pulsed Doppler clinical instrument for cardiac or peripheral vascular diagnosis. Currently, many continuous wave and pulsed Doppler instruments are commercially available for both peripheral vascular and cardiac diagnosis. This chapter (1) briefly reviews current safety guidelines, regulations, and recommendations for diagnostic ultrasound; (2) discusses the patient-exposure intensities associated with Doppler ultrasound medical equipment and compare these levels of exposure with intensities from other medical ultrasound devices; and (3) considers some of the current information as it relates to the safety of diagnostic ultrasound

  3. SAMSI: An orbiting spatial interferometer for micro-arc second astronomical observations. [Spacecraft Array for Michelson Spatial Interferometry (SAMSI)

    Science.gov (United States)

    Stachnik, R. V.; Gezari, D. Y.

    1985-01-01

    The concept and performance of (SAMSI) Spacecraft Array for Michelson Spatial Interferometry, an orbiting spatial interferometer comprised of three free-flying spacecraft, two collector telescopes and a central mixing station are described. In the one-dimensional interferometry mode orbits exist which provide natural scanning of the baseline. These orbits place extremely small demands on thrusters and fuel consumption. Resolution of 0.00001 arcsecond and magnitude limits of mv = 15 to 20 are achievable in a single orbit. In the imaging mode, SAMSI could synthesize images equivalent to those produced by equal diameter filled apertures in space, making use of the fuel resupply capability of a space station. Simulations indicate that image reconstruction can be performed with milliarcsecond resolution to a visual magnitude 12 in 12 hr of spiral scanning integration time.

  4. Vascularization of liver tumors - preliminary results with Coded Harmonic Angio (CHA), phase inversion imaging, 3D power Doppler and contrast medium-enhanced B-flow with second generation contrast agent (Optison).

    Science.gov (United States)

    Jung, E M; Kubale, R; Jungius, K-P; Jung, W; Lenhart, M; Clevert, D-A

    2006-01-01

    To investigate the dynamic value of contrast medium-enhanced ultrasonography with Optison for appraisal of the vascularization of hepatic tumors using harmonic imaging, 3D-/power Doppler and B-flow. 60 patients with a mean age of 56 years (range 35-76 years) with 93 liver tumors, including histopathologically proven hepatocellular carcinoma (HCC) [15 cases with 20 lesions], liver metastases of colorectal tumors [17 cases with 33 lesions], metastases of breast cancer [10 cases with 21 lesions] and hemangiomas [10 cases with 19 lesions] were prospectively investigated by means of multislice CT as well as native and contrast medium-enhanced ultrasound using a multifrequency transducer (2.5-4 MHz, Logig 9, GE). B scan was performed with additional color and power Doppler, followed by a bolus injection of 0.5 ml Optison. Tumor vascularization was evaluated with coded harmonic angio (CHA), pulse inversion imaging with power Doppler, 3D power Doppler and in the late phase (>5 min) with B-flow. In 15 cases with HCC, i.a. DSA was performed in addition. The results were also correlated with MRT and histological findings. Compared to spiral-CT/MRT, only 72/93 (77%) of the lesions could be detected in the B scan, 75/93 (81%) with CHA and 93/93 (100%) in the pulse inversion mode. Tumor vascularization was detectable in 43/93 (46%) of lesions with native power Doppler, in 75/93 (81%) of lesions after administering contrast medium in the CHA mode, in 81/93 (87%) of lesions in the pulse inversion mode with power Doppler and in 77/93 (83%) of lesions with contrast-enhanced B-flow. Early arterial and capillary perfusion was best detected with CHA, particularly in 20/20 (100%) of the HCC lesions, allowing a 3D reconstruction. 3D power Doppler was especially useful in investigating the tumor margins. Up to 20 min after contrast medium injection, B-flow was capable of detecting increased metastatic tumor vascularization in 42/54 (78%) of cases and intratumoral perfusion in 17/20 (85

  5. Correlation between the tissue Doppler, strain rate, strain imaging during the dobutamine infusion and coronary fractional flow reserve during catheterization: a comparative study.

    Science.gov (United States)

    Dagdelen, Sinan; Yuce, Murat; Emiroglu, Yunus; Ergelen, Mehmet; Pala, Selcuk; Tanalp, Ali Cevat; Izgi, Akin; Kirma, Cevat

    2005-06-22

    Coronary fractional flow reserve (FFR) as an invasive, and dobutamine stress echocardiography (DSE) as a noninvasive technique were used to detect critical coronary stenosis. This study was undertaken to assess correlation between these two techniques by using tissue Doppler, strain rate (SR), and strain imaging (S). In 17 patients (aged 54.9+/-12.6, 4 F), a total of 22 vessels were studied. On dobutamine stress echocardiography, baseline and peak systolic (Sm), early (Em) and late (Am) diastolic myocardial velocities, SR and S were recorded from parasternal view (mid-posterior segment) for radial and apical view (mid-septum) for longitudinal deformation. Then coronary FFR was performed by using intracoronary adenosine infusion, and the value of system were analyzed for longitudinal SR and S values, it had a mild correlation with SR (r = 0.47, p = 0.044) and a good correlation with S (r = 0.66, p = 0.002). The quantification of regional myocardial deformation by using DSE rather than the motion would be more appropriate in detecting the ischemic dysfunctional segment supplied by the critical coronary stenosis. Strain measurement during the dobutamine infusion may provide an information on the FFR results of the culprit vessel.

  6. Applications of Doppler in the first trimester

    International Nuclear Information System (INIS)

    Taylor, K.J.W.; Ramirez, B.; Grannum, P.

    1986-01-01

    Fifty patients have been studied by duplex Doppler US imaging in the first trimester. In normal gestations, luteal flow, characterized by a low pulsatility index (PI), can be seen in at least one ovary. Failure to detect luteal flow indicates a nonviable pregnancy. Six ectopic pregnancies demonstrated luteal flow and extrauterine heartbeat, detected by Doppler US. High PI values in the uterine artery are seen in the first trimester. Low PI values in the uterine arteries were found in patients with trophoblastic disease

  7. Analysis of the localization of Michelson interferometer fringes using Fourier optics and temporal coherence

    International Nuclear Information System (INIS)

    Narayanamurthy, C S

    2009-01-01

    Fringes formed in a Michelson interferometer never localize in any plane, in the detector plane and in the localization plane. Instead, the fringes are assumed to localize at infinity. Except for some explanation in Principles of Optics by Born and Wolf (1964 (New York: Macmillan)), the fringe localization phenomena of Michelson's interferometer have never been analysed seriously in any book. Because Michelson's interferometer is one of the important and fundamental optical experiments taught at both undergraduate and graduate levels, it would be appropriate to explain the localization of these fringes. In this paper, we analyse the localization of Michelson interferometer fringes using Fourier optics and temporal coherence, and show that they never localize at any plane even at infinity

  8. An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers

    International Nuclear Information System (INIS)

    Hilbert, Vinzenz; Fuchs, Silvio; Paulus, Gerhard G.; Zastrau, Ulf; Blinne, Alexander; Feigl, Torsten; Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Förster, Eckhart

    2013-01-01

    We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed

  9. Direct UV written Michelson interferometer for RZ signal generation using phase-to-intensity modulation conversion

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Geng, Yan; Zsigri, Beata

    2005-01-01

    An integrated Michelson delay interferometer structure making use of waveguide gratings as reflective elements is proposed and fabricated by direct ultraviolet writing. Successful return-to-zero alternate-mark-inversion signal generation using phase-to-intensity modulation conversion...

  10. An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers.

    Science.gov (United States)

    Hilbert, Vinzenz; Blinne, Alexander; Fuchs, Silvio; Feigl, Torsten; Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Paulus, Gerhard G; Förster, Eckhart; Zastrau, Ulf

    2013-09-01

    We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed.

  11. Sub-Doppler spectroscopy

    International Nuclear Information System (INIS)

    Hansch, T.W.

    1983-01-01

    This chapter examines Doppler-free saturation spectroscopy, tunable cw sources, and Doppler-free two-photon spectroscopy. Discusses saturation spectroscopy; continuous wave saturation spectroscopy in the ultraviolet; and two-photon spectroscopy of atomic hydrogen 1S-2S. Focuses on Doppler-free laser spectroscopy of gaseous samples. Explains that in saturation spectroscopy, a monochromatic laser beam ''labels'' a group of atoms within a narrow range of axial velocities through excitation or optical pumping, and a Doppler-free spectrum of these selected atoms is observed with a second, counterpropagating beam. Notes that in two-photon spectroscopy it is possible to record Doppler-free spectra without any need for velocity selection by excitation with two counterpropagating laser beams whose first order Doppler shifts cancel

  12. Variações de parâmetros da função diastólica do ventrículo esquerdo de acordo com a idade através da ecocardiografia com Doppler tissular Changes in the parameters of left ventricular diastolic function according to age on tissue Doppler imaging

    Directory of Open Access Journals (Sweden)

    Márcia Duarte Pedone

    2004-12-01

    Full Text Available OBJETIVO: Determinar a correlação entre as velocidades diastólicas do Doppler tissular com a idade em amostra de adultos saudáveis, e correlacionar a idade com as velocidades do fluxo transmitral e de veias pulmonares. MÉTODOS: Estudados, através da ecocardiografia, 51 indivíduos saudáveis, com idades entre 21 e 69 anos e registradas as velocidades miocárdicas diastólicas ao Doppler tissular e determinadas as velocidades dos fluxos transmitral e venoso pulmonar. RESULTADOS: As velocidades miocárdicas diastólicas iniciais septal basal e lateral basal apresentaram correlação inversa com a idade, com r = - 0,40 (p = 0,004 e r = - 0,60 (p = 0,0001 respectivamente. As velocidades atriogênicas do Doppler tissular foram diretamente correlacionadas com a idade, sendo no segmento septal basal r = 0,56 (p = 0,0001 e no segmento lateral basal r = 0,50 (p = 0,0001. As velocidades do fluxo transmitral e do fluxo venoso pulmonar também mostraram correlação com a idade. CONCLUSÃO: Existe correlação entre a idade e as velocidades miocárdicas diastólicas do Doppler tissular e com as velocidades do fluxo transmitral e fluxo venoso pulmonar, demonstrando em indivíduos saudáveis uma variação de parâmetros da função diastólica do ventrículo esquerdo com a evolução natural da idade.OBJECTIVE: To determine the correlation between diastolic velocities on tissue Doppler imaging and age in a sample of healthy adults and to correlate age with the velocities of transmitral and pulmonary vein flows. METHODS: Echocardiographic assessment of 51 healthy individuals, whose ages ranged from 21 to 69 years. The diastolic myocardial velocities were recorded on tissue Doppler imaging. The velocities of the transmitral and pulmonary vein flows were also determined. RESULTS: The initial basal septal and basal lateral diastolic myocardial velocities showed an inverse correlation with age [r = - 0.40 (P = 0.004, and r = - 0.60 (P = 0.0001, respectively

  13. Preliminary result of bunch length measurement using a modified Michelson interferometer

    International Nuclear Information System (INIS)

    Lin Xuling; Luo Feng; Bei Hua; Dai Zhimin; Chinese Academy of Sciences, Beijing; Zhang Jianbing; Lu Shanliang; Yu Tiemin

    2009-01-01

    Based on the femtosecond accelerator device which was built at the Shanghai Institute of Applied Physics (SINAP), recently a modified far infrared Michelson interferometer has been developed to measure the length of electron bunches via the optical autocorrelation method. Compared with our former normal Michelson interferometer, we use a hollow retroreflector instead of a flat mirror as the reflective mirror. The experimental setup and results of the bunch length measurement will be described in this paper. (authors)

  14. Doppler flowmetry in preeclampsia.

    Science.gov (United States)

    Zahumensky, J

    2009-01-01

    The purpose of this study was to summarize the new published data on the Doppler flowmetry in preeclampsia. We summarize the new published data on the Doppler flowmetry in uteroplacental, fetoplacental and fetal circulation in preeclampsia. The present review summarized the results of clinical research on the Doppler flowmetry in the screening of risk of preclampsia, in the diagnosis of preclampsia and in the fetal risk in preclampsia (Ref. 19). Full Text (Free, PDF) www.bmj.sk.

  15. Power and color Doppler ultrasound settings for inflammatory flow

    DEFF Research Database (Denmark)

    Torp-Pedersen, Søren; Christensen, Robin; Szkudlarek, Marcin

    2015-01-01

    OBJECTIVE: To determine how settings for power and color Doppler ultrasound sensitivity vary on different high- and intermediate-range ultrasound machines and to evaluate the impact of these changes on Doppler scoring of inflamed joints. METHODS: Six different types of ultrasound machines were used....... On each machine, the factory setting for superficial musculoskeletal scanning was used unchanged for both color and power Doppler modalities. The settings were then adjusted for increased Doppler sensitivity, and these settings were designated study settings. Eleven patients with rheumatoid arthritis (RA......) with wrist involvement were scanned on the 6 machines, each with 4 settings, generating 264 Doppler images for scoring and color quantification. Doppler sensitivity was measured with a quantitative assessment of Doppler activity: color fraction. Higher color fraction indicated higher sensitivity. RESULTS...

  16. Doppler ultrasound exam of an arm or leg

    Science.gov (United States)

    Peripheral vascular disease - Doppler; PVD - Doppler; PAD - Doppler; Blockage of leg arteries - Doppler; Intermittent claudication - Doppler; Arterial insufficiency of the legs - Doppler; Leg pain and ...

  17. Differential doppler heterodyning technique

    DEFF Research Database (Denmark)

    Lading, Lars

    1971-01-01

    Measuring velocity without disturbing the moving object is possible by use of the laser doppler heterodyning technique. Theoretical considerations on the doppler shift show that the antenna property of the photodetector can solve an apparent conflict between two different ways of calculating...

  18. Doppler ultrasound monitoring technology.

    Science.gov (United States)

    Docker, M F

    1993-03-01

    Developments in the signal processing of Doppler ultrasound used for the detection of fetal heart rate (FHR) have improved the operation of cardiotocographs. These developments are reviewed and the advantages and disadvantages of the various Doppler and signal processing methods are compared.

  19. The Cognitive Doppler.

    Science.gov (United States)

    Kozoil, Micah E.

    1989-01-01

    Discusses the learning needs of students in the concrete operational stage in mathematics. Identifies the phenomenon of reduced cognitive performance in an out-of-class environment as the "Cognitive Doppler." Suggests methods of reducing the pronounced effects of the Cognitive Doppler by capitalizing on the students' ability to memorize…

  20. Ultrasonography with color Doppler and power Doppler in the diagnosis of periapical lesions

    Science.gov (United States)

    Goel, Sumit; Nagendrareddy, Suma Gundareddy; Raju, Manthena Srinivasa; Krishnojirao, Dayashankara Rao Jingade; Rastogi, Rajul; Mohan, Ravi Prakash Sasankoti; Gupta, Swati

    2011-01-01

    Aim: To evaluate the efficacy of ultrasonography (USG) with color Doppler and power Doppler applications over conventional radiography in the diagnosis of periapical lesions. Materials and Methods: Thirty patients having inflammatory periapical lesions of the maxillary or mandibular anterior teeth and requiring endodontic surgery were selected for inclusion in this study. All patients consented to participate in the study. We used conventional periapical radiographs as well as USG with color Doppler and power Doppler for the diagnosis of these lesions. Their diagnostic performances were compared against histopathologic examination. All data were compared and statistically analyzed. Results: USG examination with color Doppler and power Doppler identified 29 (19 cysts and 10 granulomas) of 30 periapical lesions accurately, with a sensitivity of 100% for cysts and 90.91% for granulomas and a specificity of 90.91% for cysts and 100% for granulomas. In comparison, conventional intraoral radiography identified only 21 lesions (sensitivity of 78.9% for cysts and 45.4% for granulomas and specificity of 45.4% for cysts and 78.9% for granulomas). There was definite correlation between the echotexture of the lesions and the histopathological features except in one case. Conclusions: USG imaging with color Doppler and power Doppler is superior to conventional intraoral radiographic methods for diagnosing the nature of periapical lesions in the anterior jaws. This study reveals the potential of USG examination in the study of other jaw lesions. PMID:22223940

  1. Ultrasonography with color Doppler and power Doppler in the diagnosis of periapical lesions

    International Nuclear Information System (INIS)

    Goel, Sumit; Nagendrareddy, Suma Gundareddy; Raju, Manthena Srinivasa; Krishnojirao, Dayashankara Rao Jingade; Rastogi, Rajul; Mohan, Ravi Prakash Sasankoti; Gupta, Swati

    2011-01-01

    To evaluate the efficacy of ultrasonography (USG) with color Doppler and power Doppler applications over conventional radiography in the diagnosis of periapical lesions. Thirty patients having inflammatory periapical lesions of the maxillary or mandibular anterior teeth and requiring endodontic surgery were selected for inclusion in this study. All patients consented to participate in the study. We used conventional periapical radiographs as well as USG with color Doppler and power Doppler for the diagnosis of these lesions. Their diagnostic performances were compared against histopathologic examination. All data were compared and statistically analyzed. USG examination with color Doppler and power Doppler identified 29 (19 cysts and 10 granulomas) of 30 periapical lesions accurately, with a sensitivity of 100% for cysts and 90.91% for granulomas and a specificity of 90.91% for cysts and 100% for granulomas. In comparison, conventional intraoral radiography identified only 21 lesions (sensitivity of 78.9% for cysts and 45.4% for granulomas and specificity of 45.4% for cysts and 78.9% for granulomas). There was definite correlation between the echotexture of the lesions and the histopathological features except in one case. USG imaging with color Doppler and power Doppler is superior to conventional intraoral radiographic methods for diagnosing the nature of periapical lesions in the anterior jaws. This study reveals the potential of USG examination in the study of other jaw lesions

  2. Ultrasonography with color Doppler and power Doppler in the diagnosis of periapical lesions

    Directory of Open Access Journals (Sweden)

    Sumit Goel

    2011-01-01

    Full Text Available Aim: To evaluate the efficacy of ultrasonography (USG with color Doppler and power Doppler applications over conventional radiography in the diagnosis of periapical lesions. Materials and Methods: Thirty patients having inflammatory periapical lesions of the maxillary or mandibular anterior teeth and requiring endodontic surgery were selected for inclusion in this study. All patients consented to participate in the study. We used conventional periapical radiographs as well as USG with color Doppler and power Doppler for the diagnosis of these lesions. Their diagnostic performances were compared against histopathologic examination. All data were compared and statistically analyzed. Results: USG examination with color Doppler and power Doppler identified 29 (19 cysts and 10 granulomas of 30 periapical lesions accurately, with a sensitivity of 100% for cysts and 90.91% for granulomas and a specificity of 90.91% for cysts and 100% for granulomas. In comparison, conventional intraoral radiography identified only 21 lesions (sensitivity of 78.9% for cysts and 45.4% for granulomas and specificity of 45.4% for cysts and 78.9% for granulomas. There was definite correlation between the echotexture of the lesions and the histopathological features except in one case. Conclusions: USG imaging with color Doppler and power Doppler is superior to conventional intraoral radiographic methods for diagnosing the nature of periapical lesions in the anterior jaws. This study reveals the potential of USG examination in the study of other jaw lesions.

  3. Functional and morphological evaluation of hand microcirculation with nailfold capillaroscopy and laser Doppler imaging in Raynaud's and Sjögren's syndrome and poly/dermatomyositis.

    Science.gov (United States)

    Szabo, N; Csiki, Z; Szanto, A; Danko, K; Szodoray, P; Zeher, M

    2008-01-01

    Nailfold capillaroscopy is widely used in autoimmune patients to determine capillary morphology. Laser Doppler imaging (LDI) is a relatively new method for measuring the microcirculation of cutaneous perfusion. The aim of this study was to investigate the capillary morphology and microcirculation among patients with Sjögren's syndrome (SS) and poly/dermatomyositis (PM/DM) with these two non-invasive methods and to detect secondary Raynaud's syndrome (SRS) in these autoimmune diseases. Thirty patients with primary SS, 30 patients with PM/DM, 30 patients with primary Raynaud's syndrome (PRS), and 30 healthy volunteers were included in the study. Nailfold capillaroscopy and LDI were performed on each patient. A comprehensive analysis was performed among the patients and healthy individuals. Among SS patients avascularity and among PM/DM patients avascularity and capillary morphology changes were most often detected by capillaroscopy. With LDI the mean steady-state cutaneous perfusion was 1.25 perfusion units (PU) in region of interest 1 (ROI1), 1.22 in ROI2, and 1.49 at the fingertips in PRS patients; the corresponding values were 1.2, 1.03, and 1.48 PU in SS, 0.91, 0.76, and 1.19 PU in PM/DM, and 1.79, 1.62, and 2.2 PU in the controls. The differences were significant between each autoimmune group compared to the control group (pnailfold capillaroscopy, abnormalities in capillary morphology can be detected, and by using LDI, the reduced blood flow in the capillaries can be detected. These investigations can be useful in the detection of SRS, or in distinguishing whether the reduced blood flow is due to primary/systemic autoimmune diseases.

  4. Comparison of magnetic resonance imaging and Laser Doppler Anemometry velocity measurements downstream of replacement heart valves: implications for in vivo assessment of prosthetic valve function.

    Science.gov (United States)

    Fontaine, A A; Heinrich, R S; Walker, P G; Pedersen, E M; Scheidegger, M B; Boesiger, P; Walton, S P; Yoganathan, A P

    1996-01-01

    The non-invasive, in-vivo assessment of prosthetic valve function is compromised by the lack of accurate measurements of the transvalvular flow fields or hemodynamics by current techniques. Short echo time magnetic resonance imaging (MRI) may provide a method for the non-invasive, in vivo assessment of prosthetic valve function by accurately measuring changes in the transvalvular flow fields associated with normal and dysfunctional prosthetic valves. The objectives of these in vitro experiments were to investigate the potential for using MRI as a tool to measure the complex flow fields distal to replacement heart valves, and to assess the accuracy of MRI velocity measurements by comparison with Laser Doppler Anemometry (LDA), a gold standard. The velocity fields downstream of tilting disc, bileaflet, ball and cage, and pericardial tissue valves were measured using both three-component LDA and MRI phase velocity encoding under a steady flow rate of 22.8 l/min, simulating peak systolic flow. The valves were tested under normal and stenotic conditions to assess the MRI capabilities under a wide range of local flow conditions, velocities and turbulence levels. A new short echo time MRI technique (FAcE), which allowed velocity measurements in stenotic jets with high turbulence, was tested. Good overall agreement was obtained between the MRI velocity measurements and the LDA data. The MRI velocity measurements adequately reproduced the spatial structure of the flow fields. In most cases peak velocities were accurately measured to within 15%. The results indicate that the FAcE MRI method has the potential to be used as a diagnostic tool to assess prosthetic valve function.

  5. Time-resolved particle image velocimetry and laser doppler anemometry study of the turbulent flow field of bileaflet mechanical mitral prostheses.

    Science.gov (United States)

    Akutsu, Toshinosuke; Fukuda, Takamasa

    2005-01-01

    Dynamic particle image velocimetry (PIV) was applied to the study of the flow field associated with prosthetic heart valves. The results were compared with those of laser Doppler anemometry (LDA). Anatomically and antianatomically oriented Jyros (JR) and St. Jude Medical (SJM) valves were compared in the mitral position to study the effects of valve design on the downstream flow field. The experimental program used a dynamic PIV system utilizing high-speed, high-resolution video to map the true time-resolved velocity field inside the simulated ventricle. This system was complemented by a study using the more traditional LDA system for comparison. Based on the experimental data, the following general conclusions can be made. High-resolution dynamic PIV can capture true chronological changes in the velocity and turbulence fields. It also produces very detailed velocity and turbulence information comparable to the LDA results. In the vertical measuring plane that passes both the center of the aortic and mitral valves (A-A section), the two valves (the SJM and the JR) show distinct circulatory flow patterns when the valve is installed in the antianatomical orientation. Small differences in valve design can generate noticeable differences, particularly during the accelerating flow phase. The SJM valve maintains a relatively high velocity through the central orifice; the curved leaflets of the JR valve generate higher velocities with a divergent flow during the accelerating and peak flow phases. In the velocity field directly below the mitral valve and normal to the previous measuring plane (B-B section), where characteristic differences in valve design will be visible, symmetrical twin circulations were observed because of the divergent nature of the flow generated by the two inclined half-disks installed in the antianatomical orientation. The SJM valve, with a central downward flow near the valve, is contrasted with the JR valve, which has a peripheral downward

  6. Influence of detomidine on atrial fibrillation cycle length measured by intracardiac electrogram recording and by colour tissue Doppler imaging in horses.

    Science.gov (United States)

    Decloedt, A; de Clercq, D; van der Vekens, N; Verheyen, T; Ven, S; van Loon, G

    2016-01-01

    Shortening of atrial fibrillation cycle length (AFCL) is a marker of atrial electrical remodelling due to atrial fibrillation (AF). To investigate the effect of administration of detomidine on AFCL measured invasively from an intra-atrial electrogram (AFCLEGM) and noninvasively by tissue Doppler imaging (AFCLTDI). We hypothesised that detomidine would have no effect on AFCL but would improve the ease of TDI measurements and facilitate noninvasive AFCL determination. Prospective clinical study. Measurements were performed before and after i.v. administration of 7.5 μg/kg bwt detomidine in 33 episodes of AF in 32 horses (582 ± 64 kg bwt, 10 ± 3 years old) referred for electrical cardioversion. The AFCLEGM was measured from a right atrial intracardiac electrogram. The AFCLTDI was measured from atrial colour tissue velocity curves in 5 atrial wall regions. Mean AFCLEGM and AFCLTDI without and with sedation were compared using a repeated-measures linear mixed model with Bonferroni correction for multiple comparisons and calculation of the Bland-Altman mean bias and limits of agreement between AFCLEGM and AFCLTDI. The mean AFCL was significantly increased after sedation, but this increase was very small (mean difference +4 ms). For AFCLTDI measurements, sedation significantly improved the quality of the atrial myocardial velocity curves and the number of AF cycles that could be measured per cardiac cycle. The Bland-Altman bias between AFCLEGM without sedation and AFCLTDI with sedation ranged from -18 to +15 ms depending on wall region. Bland-Altman limits of agreement were similar between AFCLEGM without sedation and AFCLTDI without and with sedation. Therefore, noninvasive AFCLTDI measurements with sedation can be used to estimate the atrial fibrillatory rate. Sedation facilitates noninvasive AFCL measurements but causes a slight increase in AFCL. Noninvasive AFCL measurements can be used as an indicator of atrial electrical remodelling, to study AF

  7. Echocardiographic Assessment of Left Ventricular Function in Healthy Horses and in Horses with Heart Disease Using Pulsed-Wave Tissue Doppler Imaging.

    Science.gov (United States)

    Koenig, T R; Mitchell, K J; Schwarzwald, C C

    2017-03-01

    Assessment of left ventricular (LV) function by tissue Doppler imaging (TDI) is not well established in horses with heart disease. To describe the use of pulsed-wave (PW) TDI for the assessment of LV function, establish reference intervals, investigate effects of mitral regurgitation (MR), aortic regurgitation (AR), and primary myocardial disease (MD), and provide proof of concept for the use of PW TDI in Warmblood horses with heart disease. Thirty healthy horses, 38 horses with MR, 25 with AR, 8 with MD. Echocardiograms were retrospectively analyzed. Reference intervals were calculated. PW TDI indices of healthy horses and horses with MR, AR, and MD were compared by one-way ANOVA and Dunnett's test. A complete set of PW TDI variables could be obtained in 94 of 101 horses. Variables corresponding to isovolumic intervals were most difficult to measure. Valvular regurgitation influenced variables describing isovolumic contraction and ejection. Horses with MD had significantly shortened ET m (-118.5 [-154.1 to -82.9] ms; mean difference [95% CI of difference of means]), increased PEP m /ET m (0.11 [0.05 to 0.17]), prolonged IMP m (0.28 [0.18 to 0.37]), increased S 1 (8.9 [5.2 to 12.6] cm/s), and decreased E 1 (-2.6 [-4.7 to -0.5] cm/s), E m (-14.2 [-19.9 to -8.5] cm/s), and E m /A m ratio (-1.6 [-2.6 to -0.6]). Pulsed-wave TDI might be useful for detection of LV dysfunction in horses with primary MD. The clinical value of TDI in horses with MR and AR remains uncertain. Copyright © 2017 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

  8. Color Doppler imaging of the retrobulbar circulation and plasmatic biomarkers of vascular risk in age-related macular degeneration: A pilot study

    Directory of Open Access Journals (Sweden)

    Fermin Rodrigo

    2018-01-01

    Full Text Available Purpose: To evaluate preliminarily and compare the level of plasmatic biomarkers of vascular risk in patients with and without exudative age-related macular degeneration (ARMD and to relate it to vascular resistance alterations in the ophthalmic artery (OA, central retinal artery (CRA, posterior temporal ciliary artery (PTCA, and posterior nasal ciliary artery (PNCA. Methods: Color Doppler imaging of the OA, CRA, PTCA, and PNCA was performed in 30 eyes of 30 cataract patients (control group as well as in 30 eyes of 30 patients with naive exudative ARMD (study group, measuring the peak systolic velocity, end-diastolic velocity (EDV, and Pourcelot resistive index (RI. Likewise, in both groups, a blood test was performed to determine the plasmatic levels of homocysteine, C-reactive protein (CRP, B12 vitamin, and folic acid. Results: A positive and significant correlation was found between the level of CRP and RI of the OA in the ARMD group (r = 0.498, P = 0.005, with an increased RI in all arteries compared to controls, although differences only reached statistical significance for the PTCA (P = 0.035. Likewise, a significantly lower EDV for the CRA was found in ARMD eyes compared to controls (P = 0.041. In the study group, significantly higher plasmatic levels of homocysteine (P = 0.042 and CRP (P = 0.046 were found. In contrast, no significant differences were found between groups in the levels of folic acid (P = 0.265 and B12 vitamin (P = 0.520. Conclusion: The decrease of the choroidal perfusion related to hyperhomocysteinemia, and increase in the CRP plasmatic levels may play an etiological role on the exudative ARMD. This should be investigated in future studies with larger samples of patients.

  9. Michelson-type Radio Interferometer for University Education

    Science.gov (United States)

    Koda, Jin; Barrett, J. W.; Hasegawa, T.; Hayashi, M.; Shafto, G.; Slechta, J.

    2013-01-01

    Despite the increasing importance of interferometry in astronomy, the lack of educational interferometers is an obstacle to training the futue generation of astronomers. Students need hands-on experiments to fully understand the basic concepts of interferometry. Professional interferometers are often too complicated for education, and it is difficult to guarantee access for classes in a university course. We have built a simple and affordable radio interferometer for education and used it for an undergraduate and graduate laboratory project. This interferometer's design is based on the Michelson & Peace's stellar optical interferometer, but operates at a radio wavelength using a commercial broadcast satellite dish and receiver. Two side mirrors are surfaced with kitchen aluminum foil and slide on a ladder, providing baseline coverage. This interferometer can resolve and measure the diameter of the Sun, a nice daytime experiment which can be carried out even under a marginal weather (i.e., partial cloud coverage). Commercial broadcast satellites provide convenient point sources. By comparing the Sun and satellites, students can learn how an interferometer works and resolves structures in the sky.

  10. Infrared spectroscopy with a balloon borne Michelson interferometer. Pt. 2

    International Nuclear Information System (INIS)

    Moorwood, A.F.M.; Salinari, P.; Furniss, I.; Jennings, R.E.; King, K.J.

    1980-01-01

    Observations of the [O III] ionic fine structure lines at 52 μm and 88 μm, made at a resolution of 0.05 cm -1 with a balloon borne telescope and Michelson interferometer, are presented for the H II regions W 51, G33.6-0.2. M 17 S, M 17 N, NGC 6357, and NGC 6334. This is the first time that both [O III] lines have been measured simultaneously. Values for the electron density deduced from the line ratios are found to agree with the radio data, while the O ++ abundances indicate a lower excitation than expected in many cases. The [O I] line at 63 μm was also detected in NGC 6357. In addition, we report the first detection of the [N III] line at 57 μm which was observed from both sources in M 17 and gives the abundance ratio N/O = 0.13. This line was also marginally detected on W 51. (orig.)

  11. Power doppler 'blanching' after the application of transducer pressure

    International Nuclear Information System (INIS)

    Joshua, F.; Edmonds, J.; Lassere, M.; De Carle, R.; Rayment, M.; Bryant, C.; Shnier, R.

    2005-01-01

    The aim of this study was to determine if transducer pressure modifies power Doppler assessments of rheumatoid arthritis synovium at the metacarpophalangeal joints and metatarsophalangeal joints. Five rheumatoid arthritis patients of varying degrees of 'disease activity' and damage were assessed with power Doppler ultrasound scanning of the dominant hand second to fifth metacarpophalangeal joints. Two rheumatoid arthritis patients had their dominant foot first to fifth metatarsophalangeal joints assessed with power Doppler ultrasound. Ultrasonography was performed with a high frequency transducer (14 MHz) with a colour mode frequency of 10 Mhz, and a standard colour box and gain. In the joint that showed the highest power Doppler signal, an image was made. A further image was taken after transducer pressure was applied. In all patients, there was increased flow to at least one joint. After pressure was applied, power Doppler signal intensity markedly reduced in all images and in some there was no recordable power Doppler signal. Increased transducer pressure can result in a marked reduction or obliteration in power Doppler signal. This power Doppler 'blanching' shows the need for further studies to evaluate sources of error and standardization before power Doppler ultrasound becomes a routine measure of 'disease activity' in rheumatoid arthritis. Copyright (2005) Blackwell Science Pty Ltd

  12. Doppler radar flowmeter

    Science.gov (United States)

    Petlevich, Walter J.; Sverdrup, Edward F.

    1978-01-01

    A Doppler radar flowmeter comprises a transceiver which produces an audio frequency output related to the Doppler shift in frequency between radio waves backscattered from particulate matter carried in a fluid and the radiated radio waves. A variable gain amplifier and low pass filter are provided for amplifying and filtering the transceiver output. A frequency counter having a variable triggering level is also provided to determine the magnitude of the Doppler shift. A calibration method is disclosed wherein the amplifier gain and frequency counter trigger level are adjusted to achieve plateaus in the output of the frequency counter and thereby allow calibration without the necessity of being able to visually observe the flow.

  13. Recommendations for terminology and display for doppler echocardiography

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Doppler echocardiography has recently emerged as a major noninvasive technique with many applications in cardiology. To a large extent, this has been based upon a combination of clinical and engineering advances which now make possible the use of quantitative Doppler echocardiography in combination with two-dimensional imaging for measurement of volume flows, transvalve gradients, and other physiologic flow parameters which reflect cardiac function. It was the purpose of this Committee to provide a glossary of terms which could be used in standard fashion for papers and discussions related to Doppler echocardiography. As part of its task, the Committee also undertook an attempt to recommend a standard for display of Doppler information which would be useful, both for manufacturers and for clinicians. The document, therefore, includes: Section I, the Committee's recommendations for Doppler display. Section II, the glossary of Doppler terms, related to engineering and to clinical applications

  14. Optical refractometer based on an asymmetrical twin-core fiber Michelson interferometer.

    Science.gov (United States)

    Zhou, Ai; Zhang, Yanhui; Li, Guangping; Yang, Jun; Wang, Yuzhuo; Tian, Fengjun; Yuan, Libo

    2011-08-15

    We report and demonstrate an optical refractometer based on a compact fiber Michelson interferometer. The Michelson interferometer is composed of an asymmetrical twin-core fiber containing a central core and a side core. By chemically etching a segment of the twin-core fiber until the side core is exposed, the effective index of the side core in the etched region is sensitive to the environmental refractive index, which leads to a shift of the transmission spectrum of the Michelson interferometer. The experimental results show that such a device has a refractive index resolution of more than 800 nm/refractive index unit in the range of 1.34-1.37. © 2011 Optical Society of America

  15. Dual-recycled cavity-enhanced Michelson interferometer for gravitational-wave detection.

    Science.gov (United States)

    Müller, Guido; Delker, Tom; Tanner, David B; Reitze, David

    2003-03-01

    The baseline design for an Advanced Laser Interferometer Gravitational-Wave Observatory (Advanced LIGO) is a dual-recycled Michelson interferometer with cavities in each of the Michelson interferometer arms. We describe one possible length-sensing and control scheme for such a dual-recycled, cavity-enhanced Michelson interferometer. We discuss the principles of this scheme and derive the first-order sensing signals. We also present a successful experimental verification of our length-sensing system using a prototype tabletop interferometer. Our results demonstrate the robustness of the scheme against deviations from the idealized design. We also identify potential weaknesses and discuss possible improvements. These results as well as other benchtop experiments that we present form the basis for a sensing and control scheme for Advanced LIGO.

  16. Determination of refractive indices of biconvex lenses by use of a Michelson interferometer.

    Science.gov (United States)

    Chhaniwal, Vani K; Anand, Arun; Narayanamurthy, C S

    2006-06-10

    Measurements of lens parameters such as focal length, radius of curvature, and refractive index are important. We describe a measurement method that utilizes a Michelson interferometer to determine parameters of thin, convex lenses. The real fringe system formed by a Michelson interferometer is used to determine the focal lengths and the radii of curvature of the lenses. The refractive index of the lens material is determined from the thin-lens formula. We were able to determine the refractive indices to an accuracy as great as 99.97%. A detailed theoretical and experimental analysis is given.

  17. Detection method of nonlinearity errors by statistical signal analysis in heterodyne Michelson interferometer.

    Science.gov (United States)

    Hu, Juju; Hu, Haijiang; Ji, Yinghua

    2010-03-15

    Periodic nonlinearity that ranges from tens of nanometers to a few nanometers in heterodyne interferometer limits its use in high accuracy measurement. A novel method is studied to detect the nonlinearity errors based on the electrical subdivision and the analysis method of statistical signal in heterodyne Michelson interferometer. Under the movement of micropositioning platform with the uniform velocity, the method can detect the nonlinearity errors by using the regression analysis and Jackknife estimation. Based on the analysis of the simulations, the method can estimate the influence of nonlinearity errors and other noises for the dimensions measurement in heterodyne Michelson interferometer.

  18. A wave optics approach to the theory of the Michelson-Morley experiment

    Science.gov (United States)

    Smid, Thomas

    2017-11-01

    A consistent classical wave optics approach to the theory of the Michelson-Morley experiment shows that the original theory as applied by Michelson and Morley and others does not calculate the optical paths of the two beams correctly, primarily because of incorrectly assuming a right angle reflection in the instrument’s reference frame for the transverse beam, but also because of the incorrect assumption of aberration for the wave fronts. The theory presented in this work proves the expected variation of the phase difference when rotating the interferometer to be more than twice as large and also strongly asymmetrical around the zero line.

  19. Application of Young-Michelson and Brown-Twiss interferometers for determining geometric parameters of nonplanar rough objects

    International Nuclear Information System (INIS)

    Mandrosov, V I

    2008-01-01

    The possibility of using Young-Michelson and Brown-Twiss interferometers for measuring the angular dimensions and parameters of the surface shape of remote passively scattering and self-luminous nonplanar rough objects by optical radiation propagating from them is substantiated. The analysis is based on the properties of approximate transverse functions of field coherence B t and B t ' and intensity coherence B ti and B ti ' formed by the time averaging of the products of fields and intensities taken at two points of a receiving aperture (the prime denotes self-luminous objects). The averaging time is set to be much longer than the coherence time of radiation propagating from an object. It is shown that for the radiation coherence length much smaller than the depth of the visible region of the object, the functions B t and B t ' are proportional to the Fourier transform of the intensity distribution in the image of a remote object, which is the generalisation of the Van Cittert-Zernicke theorem to the case of a nonplanar object, while functions B ti and B ti ' are proportional to the squares of the modulus of the Fourier transform of this distribution. It is also shown that the recording of functions B t and B t ' with a Young-Michelson interferometer gives only the angular dimensions of the visible region of objects, whereas the recording of functions B ti and B ti ' with a Brown-Twiss interferometer allows one to find these dimensions and the radius of curvature of the object surface. (laser radiation scattering)

  20. The Michelson Stellar Interferometer Error Budget for Triple Triple-Satellite Configuration

    Science.gov (United States)

    Marathay, Arvind S.; Shiefman, Joe

    1996-01-01

    This report presents the results of a study of the instrumentation tolerances for a conventional style Michelson stellar interferometer (MSI). The method used to determine the tolerances was to determine the change, due to the instrument errors, in the measured fringe visibility and phase relative to the ideal values. The ideal values are those values of fringe visibility and phase that would be measured by a perfect MSI and are attributable solely to the object being detected. Once the functional relationship for changes in visibility and phase as a function of various instrument errors is understood it is then possible to set limits on the instrument errors in order to ensure that the measured visibility and phase are different from the ideal values by no more than some specified amount. This was done as part of this study. The limits we obtained are based on a visibility error of no more than 1% and a phase error of no more than 0.063 radians (this comes from 1% of 2(pi) radians). The choice of these 1% limits is supported in the literture. The approach employed in the study involved the use of ASAP (Advanced System Analysis Program) software provided by Breault Research Organization, Inc., in conjunction with parallel analytical calculations. The interferometer accepts object radiation into two separate arms each consisting of an outer mirror, an inner mirror, a delay line (made up of two moveable mirrors and two static mirrors), and a 10:1 afocal reduction telescope. The radiation coming out of both arms is incident on a slit plane which is opaque with two openings (slits). One of the two slits is centered directly under one of the two arms of the interferometer and the other slit is centered directly under the other arm. The slit plane is followed immediately by an ideal combining lens which images the radiation in the fringe plane (also referred to subsequently as the detector plane).

  1. A study of far-infrared Michelson interferometry based on fast plasma scanning

    International Nuclear Information System (INIS)

    Bartlett, D.V.; Hewitt, G.L.; Robinson, L.C.; Tait, G.D.

    1976-02-01

    Fast far-infrared multiplex spectroscopy based on a plasma-scanned Michelson interferometer is studied. Our experiments show that the interferometer has sub-millisecond time response and high spectral resolving power. In addition to a description of the experimental performance of the interferometer, we develop and discuss two different methods of interferogram inversion. (author)

  2. Quantum Mechanical Noise in a Michelson Interferometer with Nonclassical Inputs: Nonperturbative Treatment

    Science.gov (United States)

    King, Sun-Kun

    1996-01-01

    The variances of the quantum-mechanical noise in a two-input-port Michelson interferometer within the framework of the Loudon-Ni model were solved exactly in two general cases: (1) one coherent state input and one squeezed state input, and (2) two photon number states inputs. Low intensity limit, exponential decaying signal and the noise due to mixing were discussed briefly.

  3. Power-recycled michelson interferometer with a 50/50 grating beam splitter

    International Nuclear Information System (INIS)

    Friedrich, D; Burmeister, O; Britzger, M; Bunkowski, A; Danzmann, K; Schnabel, R; Clausnitzer, T; Fahr, S; Kley, E-B; Tuennermann, A

    2008-01-01

    We designed and fabricated an all-reflective 50/50 beam splitter based on a dielectric grating. This beam splitter was used to set up a power-recycled Michelson interferometer with a finesse of about F PR ∼ 880. Aspects of the diffractive beam splitter as well as of the interferometer design are discussed

  4. Power-recycled michelson interferometer with a 50/50 grating beam splitter

    OpenAIRE

    Friedrich, Daniel; Burmeister, O.; Britzger, M.; Bunkowski, A.; Clausnitzer, T.; Fahr, S.; Kley, E.B.; Tünnermann, A.; Danzmann, Karsten; Schnabel, Roman

    2008-01-01

    We designed and fabricated an all-reflective 50/50 beam splitter based on a dielectric grating. This beam splitter was used to set up a power-recycled Michelson interferometer with a finesse of about FPR ≈ 880. Aspects of the diffractive beam splitter as well as of the interferometer design are discussed.

  5. Using a Michelson Interferometer to Measure Coefficient of Thermal Expansion of Copper

    Science.gov (United States)

    Scholl, Ryan; Liby, Bruce W.

    2009-01-01

    When most materials are heated they expand. This concept is usually demonstrated using some type of mechanical measurement of the linear expansion of a metal rod. We have developed an alternative laboratory method for measuring thermal expansion by using a Michelson interferometer. Using the method presented, interference, interferometry, and the…

  6. Simple Ultra-Low-Cost Undergraduate Holography Using a Modified Michelson Interferometer.

    Science.gov (United States)

    Rudmin, J. W.; And Others

    1980-01-01

    A technique is presented for producing holograms using equipment which is already in the possesion of the majority of college physics departments, which includes a slightly modified Michelson interferometer, a helium-neon laser, and a long focal-length lens. Production of high quality holograms has been achieved by inexperienced undergraduates…

  7. A method for the coherence measurement of the supercontinuum source using Michelson interferometer

    International Nuclear Information System (INIS)

    Semenova, V A; Tsypkin, A V; Putilin, S E; Bespalov, V G

    2014-01-01

    Coherent properties of supercontinuum sources are highly significant for various applications, including low-coherence interferometry and optical frequency metrology. We propose a fast method for the spatial and temporal self-coherence of the SC measurement using Michelson interferometer without a mirror movement. Furthermore, we present self-coherence measurements of the supercontinuum, generated in microstructured fiber at 780 nm.

  8. Digital holographic amplification of interferograms in the Michelson interferometer using the phase-only LCOS modulator

    Science.gov (United States)

    Balbekin, Nikolay; Petrov, Nikolay; Pul'kin, Sergey; Shoev, Vladislav; Sevryugin, Alexander; Tursunov, Ibrohim; Venediktov, Dmitrii; Venediktov, Vladimir

    2017-10-01

    The method of amplification of hologram was applied to the so-called Rozhdestvenskiy hooks, that were obtained in the Rozhdestvenskiy interferometer (Michelson interferometer, combined with a grating spectrograph). In such a device the absorption lines reveal themselves as specific "hooks", whose curvature provides the information about the atomic oscillator force. The holographic amplification "smoothes" the hooks and thus makes their analysis much simpler.

  9. Michelson interferometer with diffractively-coupled arm resonators in second-order Littrow configuration.

    Science.gov (United States)

    Britzger, Michael; Wimmer, Maximilian H; Khalaidovski, Alexander; Friedrich, Daniel; Kroker, Stefanie; Brückner, Frank; Kley, Ernst-Bernhard; Tünnermann, Andreas; Danzmann, Karsten; Schnabel, Roman

    2012-11-05

    Michelson-type laser-interferometric gravitational-wave (GW) observatories employ very high light powers as well as transmissively-coupled Fabry-Perot arm resonators in order to realize high measurement sensitivities. Due to the absorption in the transmissive optics, high powers lead to thermal lensing and hence to thermal distortions of the laser beam profile, which sets a limit on the maximal light power employable in GW observatories. Here, we propose and realize a Michelson-type laser interferometer with arm resonators whose coupling components are all-reflective second-order Littrow gratings. In principle such gratings allow high finesse values of the resonators but avoid bulk transmission of the laser light and thus the corresponding thermal beam distortion. The gratings used have three diffraction orders, which leads to the creation of a second signal port. We theoretically analyze the signal response of the proposed topology and show that it is equivalent to a conventional Michelson-type interferometer. In our proof-of-principle experiment we generated phase-modulation signals inside the arm resonators and detected them simultaneously at the two signal ports. The sum signal was shown to be equivalent to a single-output-port Michelson interferometer with transmissively-coupled arm cavities, taking into account optical loss. The proposed and demonstrated topology is a possible approach for future all-reflective GW observatory designs.

  10. Broadband sensitivity enhancement of detuned dual-recycled Michelson interferometers with EPR entanglement

    Science.gov (United States)

    Brown, Daniel D.; Miao, Haixing; Collins, Chris; Mow-Lowry, Conor; Töyrä, Daniel; Freise, Andreas

    2017-09-01

    We demonstrate the applicability of the EPR entanglement squeezing scheme for enhancing the shot-noise-limited sensitivity of detuned dual-recycled Michelson interferometers. In particular, this scheme is applied to the GEO600 interferometer. The effect of losses throughout the interferometer, arm length asymmetries, and imperfect separation of the signal and idler beams is considered.

  11. Electron cyclotron emission measurements on JET: Michelson interferometer, new absolute calibration, and determination of electron temperature

    NARCIS (Netherlands)

    Schmuck, S.; Fessey, J.; Gerbaud, T.; Alper, B.; Beurskens, M. N. A.; de la Luna, E.; Sirinelli, A.; Zerbini, M.

    2012-01-01

    At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70-500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron

  12. A calibration mechanism based on the principles of the Michelson interferometer micro-thrust test device

    Science.gov (United States)

    Yan, Biao; Wang, Hai; Yang, Chunlai; Wen, Li

    2017-08-01

    A micro-thrust test system based on Michelson interferometer was proposed and tested. The relationship between thrust and output voltage of the calibration component in the system was calculated and verified with numerical modeling. The fitting function of the calibration component was obtained, which will be tested during future thrust test experiments.

  13. Design of a Michelson Interferometer for Quantitative Refraction Index Profile Measurements

    NARCIS (Netherlands)

    Nijholt, J.L.M.

    1998-01-01

    This book describes the theoretical design of a three camera Michelson interferometer set-up for quantitative refractive index measuerments. Although a two camera system is easier to align and less expensive, a three camera interferometer is preferred because the expected measuring accuracy is much

  14. A study of far-infrared Michelson interferometry based on fast plasma scanning

    International Nuclear Information System (INIS)

    Bartlett, D.V.; Hewitt, R.G.L.; Robinson, L.C.; Tait, G.D.

    1977-01-01

    Fast far infrared (FIR) muliplex spectroscopy based on a plasma-scanned Michelson interferometer is studied. Experiments show that the interferometer has sub-millisecond time response and high spectral resolving power. In addition to the description of the experimental performance of the interferometer, two different methods of interferogram inversion are developed and discussed. (author)

  15. Compensation of non-ideal beam splitter polarization distortion effect in Michelson interferometer

    Science.gov (United States)

    Liu, Yeng-Cheng; Lo, Yu-Lung; Liao, Chia-Chi

    2016-02-01

    A composite optical structure consisting of two quarter-wave plates and a single half-wave plate is proposed for compensating for the polarization distortion induced by a non-ideal beam splitter in a Michelson interferometer. In the proposed approach, the optimal orientations of the optical components within the polarization compensator are determined using a genetic algorithm (GA) such that the beam splitter can be treated as a free-space medium and modeled using a unit Mueller matrix accordingly. Two implementations of the proposed polarization controller are presented. In the first case, the compensator is placed in the output arm of Michelson interferometer such that the state of polarization of the interfered output light is equal to that of the input light. However, in this configuration, the polarization effects induced by the beam splitter in the two arms of the interferometer structure cannot be separately addressed. Consequently, in the second case, compensator structures are placed in the Michelson interferometer for compensation on both the scanning and reference beams. The practical feasibility of the proposed approach is introduced by considering a Mueller polarization-sensitive (PS) optical coherence tomography (OCT) structure with three polarization controllers in the input, reference and sample arms, respectively. In general, the results presented in this study show that the proposed polarization controller provides an effective and experimentally-straightforward means of compensating for the polarization distortion effects induced by the non-ideal beam splitters in Michelson interferometers and Mueller PS-OCT structures.

  16. The phenomenon of Doppler

    International Nuclear Information System (INIS)

    Stoll, I.; Seidlerova, I.; Schwippel, J.; Poss, O.; Solc, M.

    1992-01-01

    The book is devoted to the life and work of Christian Doppler and particularly to his links to Prague and to the Slovak town of Banska Stiavnica. Many historical facts concerning Doppler's activities as well as the history of physics and astronomy are collected. Information is also presented about the Czech Technical University, the Society of Czechoslovak Mathematicians and Physicists, the Czechoslovak Astronomical Society, the Czechoslovak Spectroscopic Society and the Czechoslovak Society for the History of Science and Technology. The publication is amply supplemented with historical pictorial material (M.D.). 92 figs., 82 refs

  17. Doppler radar physiological sensing

    CERN Document Server

    Lubecke, Victor M; Droitcour, Amy D; Park, Byung-Kwon; Singh, Aditya

    2016-01-01

    Presents a comprehensive description of the theory and practical implementation of Doppler radar-based physiological monitoring. This book includes an overview of current physiological monitoring techniques and explains the fundamental technology used in remote non-contact monitoring methods. Basic radio wave propagation and radar principles are introduced along with the fundamentals of physiological motion and measurement. Specific design and implementation considerations for physiological monitoring radar systems are then discussed in detail. The authors address current research and commercial development of Doppler radar based physiological monitoring for healthcare and other applications.

  18. Doppler ion program description

    International Nuclear Information System (INIS)

    Henline, P.

    1980-12-01

    The Doppler spectrometer is a conventional Czerny-Turner grating spectrometer with a 1024 channel multiple detector. Light is dispersed across the detector, and its output yields a spectrum covering approximately 200 A. The width of the spectral peak is directly proportional to the temperature of the emitting ions, and determination of the impurity ion temperature allows one to infer the plasma ion temperature. The Doppler ion software system developed at General Atomic uses a TRACOR Northern 1710-31 and an LSI-11/2. The exact configuration of Doublet III is different from TRACOR Northern systems at other facilities

  19. Pulse Doppler radar

    CERN Document Server

    Alabaster, Clive

    2012-01-01

    This book is a practitioner's guide to all aspects of pulse Doppler radar. It concentrates on airborne military radar systems since they are the most used, most complex, and most interesting of the pulse Doppler radars; however, ground-based and non-military systems are also included. It covers the fundamental science, signal processing, hardware issues, systems design and case studies of typical systems. It will be a useful resource for engineers of all types (hardware, software and systems), academics, post-graduate students, scientists in radar and radar electronic warfare sectors and milit

  20. Avaliação dos tumores hepáticos ao Doppler Doppler evaluation of liver tumors

    Directory of Open Access Journals (Sweden)

    Márcio Martins Machado

    2004-10-01

    Full Text Available Os avanços recentes na ultra-sonografia têm ampliado a possibilidade de detecção de tumores hepáticos. Isto tem auxiliado na perspectiva de melhora do prognóstico destes pacientes, à medida que novas técnicas terapêuticas têm surgido. Neste artigo os autores relatam achados ao Doppler que podem auxiliar na identificação e caracterização dos tumores hepáticos, avaliando dados do Doppler colorido, pulsado e do Doppler de amplitude ("power Doppler". Fazem, também, referência a novas modalidades de imagem, como o uso da harmônica.Recent advances in ultrasound have optimized the detection of liver tumors and helped to improve the prognosis of patients with this condition as newly developed and improved therapeutic modalities have been established. The authors review important Doppler findings which may help in the identification and characterization of some hepatic tumors through the evaluation of color Doppler, pulsed Doppler and power Doppler features. New imaging methods such as the use of harmonics imaging are also reviewed.

  1. Doppler evaluation of valvular stenosis

    International Nuclear Information System (INIS)

    Kisslo, J.; Krafchek, J.; Adams, D.; Mark, D.B.

    1986-01-01

    One of the reasons why use of Doppler echocardiography is growing rapidly is because of its utility in detecting the presence of valvular stenosis and in estimating its severity. Detection of the presence of stenotic valvular heart disease using Doppler echocardiography was originally described over 10 years ago. It has been demonstrated that Doppler blood velocity data could be used to estimate the severity of a stenotic lesion. This chapter discusses the evaluation of valvular stenois using Doppler

  2. Doppler color flow mapping of peripheral vessels: Comparison of angiodynography with conventional duplex US

    International Nuclear Information System (INIS)

    Merritt, C.R.B.; Bluth, E.I.; Sullivan, M.A.

    1986-01-01

    A new Doppler color flow imager was compared to duplex US in the evaluation of carotid and peripheral vessels in 50 patients. A 7.5-MHz transducer permitted simultaneous high-resolution real-time imaging of Doppler flow and tissue. The system was found to have excellent image quality and Doppler sensitivity. Flow characteristics and velocity measurements obtained with this system correlated well with those obtained using the duplex scanner and were obtained more quickly than with the conventional system, allowing more complete assessment of flow characteristics. Color Doppler flow imaging appears to be an extremely promising method for the rapid and effective evaluation of peripheral vascular flow

  3. Doppler-musical instrument

    International Nuclear Information System (INIS)

    Sato, T.J.; Watanabe, N.

    2001-01-01

    We propose a possible ultra-high energy resolution backscattering spectrometer optimized to spallation neutron source. A combination of multi monochromator crystal and Doppler drive provides considerable neutron flux, together with the reasonable energy range -30 < E < 30 μeV, even when the ultra-high energy resolution of ΔE∼0.03 μeV is attained. (author)

  4. Scanning laser Doppler vibrometry

    DEFF Research Database (Denmark)

    Brøns, Marie; Thomsen, Jon Juel

    With a Scanning Laser Doppler Vibrometer (SLDV) a vibrating surface is automatically scanned over predefined grid points, and data processed for displaying vibration properties like mode shapes, natural frequencies, damping ratios, and operational deflection shapes. Our SLDV – a PSV-500H from...

  5. Glare Spot Phase Doppler Anemometry

    Science.gov (United States)

    Hespel, Camille; Ren, Kuanfang; Gréhan, Gérard; Onofri, Fabrice

    2007-06-01

    The Phase Doppler anemometry has been developed to measure simultaneously the velocity and the size of droplets. The measurement of the refractive index would be also interesting since it depends on the temperature and the composition of the particle and its measurement permits both to increase the quality of the diameter measurement and to obtain information on the temperature and/or the composition of the droplets. In this paper, we introduce a Glare Spot Phase Doppler Anemometry which uses two large beams. In this case, the images of the particle formed by the reflected and refracted light, known as glare spots, are separated in space. When a particle passes in the probe volume, the two parts in a signal obtained by a detector in forward direction are then separated in time. If two detectors are used the phase differences between two signals, the distance and the intensity ratio of reflected and refracted parts can be obtained and they provide rich information about the particle diameter and its refractive index, as well as its velocity. This paper is devoted to the numerical study of such a configuration with two theoretical models: geometrical optics and rigorous electromagnetism solution.

  6. Field programmable gate array-based real-time optical Doppler tomography system for in vivo imaging of cardiac dynamics in the chick embryo

    DEFF Research Database (Denmark)

    Thrane, Lars; Larsen, Henning Engelbrecht; Norozi, Kambiz

    2009-01-01

    efficient and compact implementation by combining the conversion to an analytic signal with a pulse shaping function without the need for extra resources as compared to the Hilbert transform method. The conversion of the analytic signal to amplitude and phase is done by use of the coordinate rotation......We demonstrate a field programmable gate-array-based real-time optical Doppler tomography system. A complex-valued bandpass filter is used for the first time in optical coherence tomography signal processing to create the analytic signal. This method simplifies the filter design, and allows...

  7. A spontaneous pre-anastomotic occlusion does not necessarily impair forearm native dialysis fistulas: echo-Doppler, 3D MR angiographic and digital subtraction angiographic imaging.

    Science.gov (United States)

    Verbeeck, N; Pillet, J C; Prospert, E; McLntyre, D; Lamy, S

    2013-01-01

    Renal transplantation is the choice treatment of end-stage renal disease. When it is not indicated or not immediately feasible, hemodialysis must be performed, preferably via a native arteriovenous fistula in the forearm. A pre-anastomotic occlusion of this type of fistula is often accompanied by a thrombosis of its draining vein. In some instances, the venous segment may remain permeable thanks to the development of arterial collateral pathways and may even allow efficient dialysis without any clinical syndrome of distal steal. We present the echo-Doppler, magnetic and angiographic characteristics of three of these collateralized shunts that have remained functional, in one of the cases following a percutaneous dilation.

  8. Complex regression Doppler optical coherence tomography

    Science.gov (United States)

    Elahi, Sahar; Gu, Shi; Thrane, Lars; Rollins, Andrew M.; Jenkins, Michael W.

    2018-04-01

    We introduce a new method to measure Doppler shifts more accurately and extend the dynamic range of Doppler optical coherence tomography (OCT). The two-point estimate of the conventional Doppler method is replaced with a regression that is applied to high-density B-scans in polar coordinates. We built a high-speed OCT system using a 1.68-MHz Fourier domain mode locked laser to acquire high-density B-scans (16,000 A-lines) at high enough frame rates (˜100 fps) to accurately capture the dynamics of the beating embryonic heart. Flow phantom experiments confirm that the complex regression lowers the minimum detectable velocity from 12.25 mm / s to 374 μm / s, whereas the maximum velocity of 400 mm / s is measured without phase wrapping. Complex regression Doppler OCT also demonstrates higher accuracy and precision compared with the conventional method, particularly when signal-to-noise ratio is low. The extended dynamic range allows monitoring of blood flow over several stages of development in embryos without adjusting the imaging parameters. In addition, applying complex averaging recovers hidden features in structural images.

  9. Refractometric sensor based on all-fiber coaxial Michelson and Mach-Zehnder interferometers for ethanol detection in fuel

    International Nuclear Information System (INIS)

    Mosquera, L; Osorio, Jonas H; Hayashi, Juliano G; Cordeiro, Cristiano M B

    2011-01-01

    A refractometric sensor based on mechanically induced interferometers formed with long period gratings is reported. It is also shown two different setups based on a Michelson and Mach-Zehnder interferometer and its application to measure ethanol concentration in gasoline.

  10. Design and Ground Calibration of the Helioseismic and Magnetic Imager (HMI) Instrument on the Solar Dynamics Observatory (SDO)

    Science.gov (United States)

    Schou, J.; Scherrer, P. H.; Bush, R. I.; Wachter, R.; Couvidat, S.; Rabello-Soares, M. C.; Bogart, R. S.; Hoeksema, J. T.; Liu, Y.; Duvall, T. L., Jr.; hide

    2012-01-01

    The Helioseismic and Magnetic Imager (HMI) investigation will study the solar interior using helioseismic techniques as well as the magnetic field near the solar surface. The HMI instrument is part of the Solar Dynamics Observatory (SDO) that was launched on 11 February 2010. The instrument is designed to measure the Doppler shift, intensity, and vector magnetic field at the solar photosphere using the 6173 Fe I absorption line. The instrument consists of a front-window filter, a telescope, a set of wave plates for polarimetry, an image-stabilization system, a blocking filter, a five-stage Lyot filter with one tunable element, two wide-field tunable Michelson interferometers, a pair of 4096(exo 2) pixel cameras with independent shutters, and associated electronics. Each camera takes a full-disk image roughly every 3.75 seconds giving an overall cadence of 45 seconds for the Doppler, intensity, and line-of-sight magnetic-field measurements and a slower cadence for the full vector magnetic field. This article describes the design of the HMI instrument and provides an overview of the pre-launch calibration efforts. Overviews of the investigation, details of the calibrations, data handling, and the science analysis are provided in accompanying articles.

  11. Doppler-musical instrument

    Energy Technology Data Exchange (ETDEWEB)

    Sato, T.J. [National Research Institute for Metals, Tsukuba, Ibaraki (Japan); Watanabe, N. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Shibata, K. [Institute for Materials Research, Tohoku Univ., Sendai, Miyagi (Japan)

    2001-03-01

    We propose a possible ultra-high energy resolution backscattering spectrometer optimized to spallation neutron source. A combination of multi monochromator crystal and Doppler drive provides considerable neutron flux, together with the reasonable energy range -30 < E < 30 {mu}eV, even when the ultra-high energy resolution of {delta}E{approx}0.03 {mu}eV is attained. (author)

  12. Color Doppler US of the penis

    Energy Technology Data Exchange (ETDEWEB)

    Bertolotto, Michele (ed.) [Trieste Univ. Ospedale di Cattinara (Italy). Dept. Radiology

    2008-07-01

    This book provides a comprehensive reference and practical guide on the application of US to penile diseases and conditions. After introductory chapters on technical requirements and penile anatomy, subsequent chapters offer a systematic overview of the diverse applications of color Doppler US. The topics covered include erectile dysfunction, Peyronie's disease, priapism, trauma, tumors, the postoperative penis, inflammation, and fibrosis. Each topic is introduced by a clinical overview with the purpose of clarifying the problems and elucidating what the urologist may expect from color Doppler US. Thereafter, performance of the US study is explained and the pathological anatomy reviewed. High-quality images obtained with high-end US equipment are included. Each chapter also contains a section on the diagnostic information provided by other imaging modalities, and in particular MRI. (orig.)

  13. Q-switched operation with Fox-Smith-Michelson laser cavity

    International Nuclear Information System (INIS)

    Huang, X; Huang, L; Gong, M

    2008-01-01

    A new kind of three-mirror composite cavity, Fox-Smith-Michelson cavity has been configured. This laser cavity is capable of high power output, owing to the low threshold of Michelson cavity. Also, thanks to the mode selection function of Fox-Smith cavity, stable pulses at high repetition rate can be generated. In our experiment, 15.54 W CW output at 1064 nm has been achieved, with an optic-to-optic conversion efficiency of 42.2%. At the Q-switching repetition rate of 100 kHz, the average output power is 11.92 W, with an optic-to-optic conversion efficiency of 38.2%. For Q-switching frequency from 30 kHz to 100 kHz, the pulse width variation is below 4.4% and the amplitude variation is below 4.8%

  14. Development of a control scheme of homodyne detection for extracting ponderomotive squeezing from a Michelson interferometer

    International Nuclear Information System (INIS)

    Sakata, Shihori; Kawamura, Seiji; Sato, Shuichi; Somiya, Kentaro; Arai, Koji; Fukushima, Mitsuhiro; Sugamoto, Akio

    2006-01-01

    We developed a control scheme of homodyne detection. To operate the homodyne detector as easy as possible, a simple Michelson interferometer is used. Here a motivation that the control scheme of the homodyne detection is developed is for our future experiment of extracting the ponderomotively squeezed vacuum fluctuations. To obtain the best signalto- noise ratio using the homodyne detection, the homodyne phase should be optimized. The optimization of the homodyne phase is performed by changing a phase of a local oscillator for the homodyne detection from a point at which a signal is maximized. In fact, in this experiment, using the developed control scheme, we locked the Michelson interferometer with the homodyne detector and changed the phase of the local oscillator for the homodyne detection. Then, we measured signals quantity changed by changing the phase of the local oscillator for the homodyne detection. Here we used the output from the homodyne detection as the signal

  15. A hybrid Fabry–Perot/Michelson interferometer sensor using a dual asymmetric core microstructured fiber

    International Nuclear Information System (INIS)

    Frazão, O; Silva, S F; Viegas, J; Baptista, J M; Santos, J L; Roy, P

    2010-01-01

    A hybrid Fabry–Perot/Michelson interferometer sensor using a dual asymmetric core microstructured fiber is demonstrated. The hybrid interferometer presents three waves. Two parallel Fabry–Perot cavities with low finesse are formed between the splice region and the end of a dual-core microstructured fiber. A Michelson configuration is obtained by the two small cores of the microstructured fiber. The spectral response of the hybrid interferometer presents two pattern fringes with different frequencies due to the respective optical path interferometers. The hybrid interferometer was characterized in strain and temperature presenting different sensitivity coefficients for each topology. Due to these characteristics, this novel sensing head is able to measure strain and temperature, simultaneously

  16. Study of optically thin electron cyclotron emission from TFTR using a Michelson interferometer

    International Nuclear Information System (INIS)

    Stauffer, F.J.; Boyd, D.A.

    1986-01-01

    The TFTR Michelson interferometer, which is used as an electron temperature diagnostic, has a spectral range of 75-540 GHz. This range is adequate for measuring at least the first three cyclotron harmonics, and it spans both optically thick and thin portions of the ECE spectrum. During the most recent opening of the TFTR vacuum vessel, a concave, carbon reflector was installed on the back wall of the vessel, opposite the light collecting optic of the Michelson system. The reflector is designed to prevent the observation of optically thin ECE that originates from a location that is outside the field of view of the light collecting optic. If this is achieved, it should be possible to derive the electron density profile from measurements of either the extraordinary mode third harmonic or the ordinary mode second harmonic. An analysis of ECE spectra that have been measured before and after installation of the reflector is presented

  17. Microwave interrogated large core fused silica fiber Michelson interferometer for strain sensing.

    Science.gov (United States)

    Hua, Liwei; Song, Yang; Huang, Jie; Lan, Xinwei; Li, Yanjun; Xiao, Hai

    2015-08-20

    A Michelson-type large core optical fiber sensor has been developed, which is designed based on the optical carrier-based microwave interferometry technique, and fabricated by using two pieces of 200-μm diameter fused silica core fiber as two arms of the Michelson interferometer. The interference fringe pattern caused by the optical path difference of the two arms is interrogated in the microwave domain, where the fringe visibility of 40 dB has easily been obtained. The strain sensing at both room temperature and high temperatures has been demonstrated by using such a sensor. Experimental results show that this sensor has a linear response to the applied strain, and also has relatively low temperature-strain cross talk. The dopant-free quality of the fused silica fiber provides high possibility for the sensor to have promising strain sensing performance in a high temperature environment.

  18. Michelson mode selector for spectral range stabilization in a self-sweeping fiber laser.

    Science.gov (United States)

    Tkachenko, A Yu; Vladimirskaya, A D; Lobach, I A; Kablukov, S I

    2018-04-01

    We report on spectral range stabilization in a self-sweeping laser by adding a narrowband fiber Bragg grating (FBG) to the output mirror in the Michelson configuration. The effects of FBG reflectivity and optical path difference in the Michelson interferometer on the laser spectral dynamics are investigated. Optimization of the interferometer allows us to demonstrate broadband (over 16 nm) self-sweeping operation and reduction of the start and stop wavelength fluctuations by two orders and one order of magnitude (∼100 and 15 times) for start and stop bounds, respectively (down to several picometers). The proposed approaches significantly improve quality of the spectral dynamics and facilitate application of the self-sweeping lasers.

  19. Colour Doppler ultrasound of the penis

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, C.J.; Sriprasad, S.; Sidhu, P.S. E-mail: paulsidhu@compuserve.com

    2003-07-01

    Because it is a superficial structure, the penis is ideally suited to ultrasound imaging. A number of disease processes, including Peyronie's disease, penile fractures and penile tumours, are clearly visualized with ultrasound. An assessment of priapism can also be made using spectral Doppler waveform technology. Furthermore, dynamic assessment of cavernosal arterial changes after pharmaco-stimulation allows diagnosis of arterial and venogenic causes for impotence. This pictorial review illustrates the range of diseases encountered with ultrasound of the penis.

  20. Experiments on the Porch Swing Bearing of Michelson Interferometer for Low Resolution FTIR

    OpenAIRE

    Tuomas Välikylä; Jyrki Kauppinen

    2013-01-01

    Porch swing bearing for the linear motion of the mirror in Michelson interferometer for mid-infrared low resolution Fourier transform spectrometer was studied experimentally using the modulation depth of the collimated laser beam. The mirror tilting was measured to be lower than 5 μrad over 3 mm mirror travel using two different bearings assemblies. Additionally, the manufacturing tolerances of the bearing type were proved to be loose enough not to limit the interferometer application. These ...

  1. Reduction of quantum noise in the Michelson interferometer by use of squeezed vacuum states

    International Nuclear Information System (INIS)

    Assaf, Ohad; Ben-Aryeh, Yacob

    2002-01-01

    We develop further the unified model for treating photon-counting and radiation-pressure fluctuations in the Michelson interferometer with input of squeezed vacuum state. The dependence of the quantum fluctuations on the phase of the input light is calculated. The analysis is restricted to a single-mode interferometer, but generalized in a way that includes both harmonic-oscillator and floating mirrors. We compare our results with those of other authors

  2. Quasi zero-background tunable diode laser absorption spectroscopy employing a balanced Michelson interferometer.

    Science.gov (United States)

    Guan, Zuguang; Lewander, Märta; Svanberg, Sune

    2008-12-22

    Tunable diode laser spectroscopy (TDLS) normally observes small fractional absorptive reductions in the light flux. We show, that instead a signal increase on a zero background can be obtained. A Michelson interferometer, which is initially balanced out in destructive interference, is perturbed by gas absorption in one of its arms. Both theoretical analysis and experimental demonstration show that the proposed zero-background TDLS can improve the achievable signal-to-noise ratio.

  3. A compact, high resolution Michelson interferometer for atmospheric spectroscopy in the near ultraviolet

    Science.gov (United States)

    Sander, Stanley P.; Cageao, Richard P.; Friedl, Randall R.

    1993-01-01

    A new, compact Fourier Transform Michelson interferometer (FTUV) with an apodized resolving power greater than 300,000 at 300 nm, high throughput and wide spectral coverage has been developed. The objectives include atmospheric spectroscopy (direct solar absorption and solar scattering) and laboratory spectroscopy of transient species. In this paper, we will briefly describe the prototype FTUV instrument and the results of preliminary laboratory investigations of OH and ClO spectra in emission and absorption.

  4. Refractive index sensor based on an abrupt taper Michelson interferometer in a single-mode fiber.

    Science.gov (United States)

    Tian, Zhaobing; Yam, Scott S-H; Loock, Hans-Peter

    2008-05-15

    A simple refractive index sensor based on a Michelson interferometer in a single-mode fiber is constructed and demonstrated. The sensor consists of a single symmetrically abrupt taper region in a short piece of single-mode fiber that is terminated by approximately 500 nm thick gold coating. The sensitivity of the new sensor is similar to that of a long-period-grating-type sensor, and its ease of fabrication offers a low-cost alternative to current sensing applications.

  5. Universal Michelson Gires-Tournois interferometer optical interleaver based on digital signal processing.

    Science.gov (United States)

    Zhang, Juan; Yang, Xiaowei

    2010-03-01

    Optical interleavers based on Michelson Gires-Tournois interferometer (MGTI) with arbitrary cascaded reflectors for symmetrical or asymmetrical periodic frequency response with arbitrary duty cycles are defined as universal MGTI optical interleaver (UMGTIOI). It can significantly enhance flexibility and applicability of optical networks. A novel and simple method based on digital signal processing is proposed for the design of UMGTIOI. Different kinds of design examples are given to confirm effectiveness of the method.

  6. Electrically switchable holographic liquid crystal/polymer Fresnel lens using a Michelson interferometer.

    Science.gov (United States)

    Jashnsaz, Hossein; Mohajerani, Ezeddin; Nemati, Hossein; Razavi, Seyed Hossein; Alidokht, Isa Ahmad

    2011-06-10

    A holographic technique for fabricating an electrically switchable liquid crystal/polymer composite Fresnel lens is reported. A Michelson interferometer is used to produce the required Fresnel pattern, by placing a convex lens into one path of the interferometer. Simplicity of the method and the possibility of fabricating different focal length lenses in a single arrangement are advantages of the method. The performance of the fabricated lens was demonstrated and its electro-optical properties were investigated for its primary focal length.

  7. Dynamic spectro-polarimeter based on a modified Michelson interferometric scheme.

    Science.gov (United States)

    Dembele, Vamara; Jin, Moonseob; Baek, Byung-Joon; Kim, Daesuk

    2016-06-27

    A simple dynamic spectro-polarimeter based on a modified Michelson interferometric scheme is described. The proposed system can extract a spectral Stokes vector of a transmissive anisotropic object. Detail theoretical background is derived and experiments are conducted to verify the feasibility of the proposed novel snapshot spectro-polarimeter. The proposed dynamic spectro-polarimeter enables us to extract highly accurate spectral Stokes vector of any transmissive anisotropic object with a frame rate of more than 20Hz.

  8. System analysis of a tilted field-widened Michelson interferometer for high spectral resolution lidar.

    Science.gov (United States)

    Liu, Dong; Hostetler, Chris; Miller, Ian; Cook, Anthony; Hair, Johnathan

    2012-01-16

    High spectral resolution lidars (HSRLs) have shown great value in aircraft aerosol remote sensing application and are planned for future satellite missions. A compact, robust, quasi-monolithic tilted field-widened Michelson interferometer is being developed as the spectral discrimination filter for an second-generation HSRL(HSRL-2) at NASA Langley Research Center. The Michelson interferometer consists of a cubic beam splitter, a solid arm and an air arm. Piezo stacks connect the air arm mirror to the body of the interferometer and can tune the interferometer within a small range. The whole interferometer is tilted so that the standard Michelson output and the reflected complementary output can both be obtained. In this paper, the transmission ratio is proposed to evaluate the performance of the spectral filter for HSRL. The transmission ratios over different types of system imperfections, such as cumulative wavefront error, locking error, reflectance of the beam splitter and anti-reflection coatings, system tilt, and depolarization angle are analyzed. The requirements of each imperfection for good interferometer performance are obtained.

  9. Experimental demonstration of a variable reflectivity signal recycled Michelson interferometer for gravitational wave detection

    International Nuclear Information System (INIS)

    De Vine, G.; Shaddock, D.; McClelland, D.

    2002-01-01

    Full text: One technique of improving the sensitivity of interferometric gravitational wave detectors is to implement a signal mirror. This involves placing a mirror at the output of the Michelson interferometer. The gravitational wave signal is then 'recycled' back into the interferometer where it can coherently add with the gravitational wave signal still being produced. The frequency of the improved sensitivity is dependent on the position of the signal mirror, while the peak height and bandwidth are dependent on the reflectivity of the signal mirror. This is because the signal mirror forms a cavity with the Michelson interferometer and this cavity has a resonant frequency dependent on its length and a bandwidth dependent on its finesse, which are a function of signal mirror position and reflectivity, respectively. Due to the varying and/or unknown nature of the gravitational wave frequencies and wave-forms, it is desirable to be able to control both the peak frequency and bandwidth of the detector. The peak frequency can be easily adjusted by altering the signal mirror position. The bandwidth, however, is fixed with the signal mirror reflectivity. In a long base-line gravitational wave detector it is impractical to swap the signal mirror with one of different reflectivity for a number of reasons, for example, the detector's high vacuum would have to be broken, realignment performed and locking re-acquired. This is addressed by the proposal of two different forms of variable reflectivity signal mirror (VRSM): a Fabry-Perot cavity and a Michelson interferometer. These are analysed and the reasons for choosing to investigate the Michelson VRSM are given. The reasons include the potential for easier control and the smooth variation in reflectivity with arm length difference. The experiment is discussed and the results of the first demonstration of variable reflectivity signal recycling are presented in the form of frequency responses obtained by injecting a second

  10. Influence of the tilting reflection mirror on the temperature and wind velocity retrieved by a polarizing atmospheric Michelson interferometer.

    Science.gov (United States)

    Zhang, Chunmin; Li, Ying

    2012-09-20

    The principles of a polarizing atmospheric Michelson interferometer are outlined. The tilt of its reflection mirror results in deflection of the reflected beam and affects the intensities of the observed inteferogram. This effect is systematically analyzed. Both rectangular and circular apertures are considered. The theoretical expression of the modulation depth and phase of the interferogram are derived. These parameters vary with the inclination angle of the mirror and the distance between the deflection center and the optical axis and significantly influence the retrieved temperature and wind speed. If the wind and temperature errors are required to be less than 3 m/s and 5 K, the deflection angle must be less than 0.5°. The errors are also dependent on the shape of aperture. If the reflection mirror is deflected in one direction, the temperature error is smaller for a circular aperture (1.3 K) than for a rectangular one (2.6 K), but the wind velocity errors are almost the same (less than 3 m/s). If the deflection center and incident light beam are coincident, the temperature errors are 3 × 10(-4) K and 0.45 K for circular and rectangular apertures, respectively. The wind velocity errors are 1.2 × 10(-3) m/s and 0.06 m/s. Both are small. The result would be helpful for theoretical research and development of the static polarization wind imaging interferometer.

  11. Use of Doppler ultrasound for non-invasive urodynamic diagnosis

    Directory of Open Access Journals (Sweden)

    Hideo Ozawa

    2009-01-01

    Full Text Available Objectives: A totally non-invasive transperineal urodynamic technique using Doppler ultrasonography has been developed. Methods: Since normal urine does not have blood cells, urine was thought not to produce the Doppler effects. However, basic studies confirmed that the decrease of pressure at high velocity (Bernouilli effect caused dissolved gas to form microbubbles, which are detected by Doppler ultrasonography. Subjects sat and the probe was advanced via remote control to achieve gentle contact with the perineal skin. The digital uroflow data signals and the color Doppler ultrasound video images were processed on a personal computer. The flow-velocity curves from two sites; the distal prostatic urethra just above the external sphincter (V1 and the sphincteric urethra (V2 were plotted against time. The parameters of both the pressure-flow studies and the Doppler ultrasound urodynamic studies were compared in men who had various degrees of obstruction. Results: Functional cross-sectional area at prostatic urethra (A1, calculated by Q max /V1, was lower in the group of bladder outlet obstruction (BOO vs. control group. Velocity ratio (VR, which was calculated by V1/V2, was the parameter having the best correlation with BOO index, though A1 had a similar correlation. This method is viable to diagnose the degree of BOO. Conclusions: The development of non-invasive Doppler ultrasound videourodynamics (Doppler UDS will dramatically expand the information on voiding function.

  12. Prenatal color Doppler ultrasonographic diagnosis of fetal tetralogy of Fallot

    International Nuclear Information System (INIS)

    Tan Buqiao

    2009-01-01

    Objective: To investigate the sonographic findings of tetralogy of Fallot in fetuses. Methods: The data of color Doppler ultrasonography and follow-up results of 5 fetal tetralogy of Fallot were analyzed retrospectively, and their abnormal ultrasound imaging characteristic were summarized. Results: Two cases were proved tetralogy of Fallot by autopsy, and three cases were confirmed to be tetralogy of Fallot by echocardiography after birth. The image features were the main aorta situated above the ventricular septal defect, pulmonary stenosis, no obvious thickening of the right wall. Conclusion: Fetal tetralogy of Fallot have characteristic ultrasound images, prenatal color Doppler ultrasonographic can diagnoses fetal tetralogy of Fallot correctly and has important clinical value. (authors)

  13. Comparisons between PW Doppler system and enhanced FM Doppler system

    DEFF Research Database (Denmark)

    Wilhjelm, Jens E.; Pedersen, P. C.

    1995-01-01

    This paper presents a new implementation of an echo-ranging FM Doppler system with improved performance, relative to the FM Doppler system reported previously. The use of long sweeps provides a significant reduction in peak to average power ratio compared to pulsed wave (PW) emission. A PW Doppler...... system exploits the direct relationship between arrival time of the received signal and range from the transducer. In the FM Doppler systems, a similar relationship exists in the spectral domain of the demodulated received signals, so that range is represented by frequency. Thus, a shift in location...... of moving scatterers between consecutive emissions corresponds to a frequency shift in the spectral signature. The improvement relative to the earlier version of the FM Doppler system is attained by utilizing cross-correlation of real spectra rather than of magnitude spectra for assessing flow velocity...

  14. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... those sound waves to create an image. Ultrasound examinations do not use ionizing radiation (as used in ... ultrasound study may be part of an ultrasound examination. Doppler ultrasound , also called color Doppler ultrasonography, is ...

  15. General Ultrasound Imaging

    Medline Plus

    Full Text Available ... D images. A Doppler ultrasound study may be part of an ultrasound examination. Doppler ultrasound , also called ... terms of the distance traveled per unit of time, rather than as a color picture. It can ...

  16. Moving Target Detection With Compact Laser Doppler Radar

    Science.gov (United States)

    Sepp, G.; Breining, A.; Eisfeld, W.; Knopp, R.; Lill, E.; Wagner, D.

    1989-12-01

    This paper describes an experimental integrated optronic system for detection and tracking of moving objects. The system is based on a CO2 waveguide laser Doppler ra-dar with homodyne receiver and galvanometer mirror beam scanner. A "hot spot" seeker consisting of a thermal imager with image processor transmits the coordinates of IR-emitting, i.e. potentially powered, objects to the laser radar scanner. The scanner addresses these "hot" locations operating in a large field-of-view (FOV) random ac-cess mode. Hot spots exhibiting a Doppler shifted laser signal are indicated in the thermal image by velocity-to-colour encoded markers. After switching to a small FOV scanning mode, the laser Doppler radar is used to track fast moving objects. Labora-tory and field experiments with moving objects including rotating discs, automobiles and missiles are described.

  17. Deconvoluting double Doppler spectra

    International Nuclear Information System (INIS)

    Ho, K.F.; Beling, C.D.; Fung, S.; Chan, K.L.; Tang, H.W.

    2001-01-01

    The successful deconvolution of data from double Doppler broadening of annihilation radiation (D-DBAR) spectroscopy is a promising area of endeavour aimed at producing momentum distributions of a quality comparable to those of the angular correlation technique. The deconvolution procedure we test in the present study is the constrained generalized least square method. Trials with computer simulated DDBAR spectra are generated and deconvoluted in order to find the best form of regularizer and the regularization parameter. For these trials the Neumann (reflective) boundary condition is used to give a single matrix operation in Fourier space. Experimental D-DBAR spectra are also subject to the same type of deconvolution after having carried out a background subtraction and using a symmetrize resolution function obtained from an 85 Sr source with wide coincidence windows. (orig.)

  18. Adaptive Spectral Doppler Estimation

    DEFF Research Database (Denmark)

    Gran, Fredrik; Jakobsson, Andreas; Jensen, Jørgen Arendt

    2009-01-01

    . The methods can also provide better quality of the estimated power spectral density (PSD) of the blood signal. Adaptive spectral estimation techniques are known to pro- vide good spectral resolution and contrast even when the ob- servation window is very short. The 2 adaptive techniques are tested......In this paper, 2 adaptive spectral estimation techniques are analyzed for spectral Doppler ultrasound. The purpose is to minimize the observation window needed to estimate the spectrogram to provide a better temporal resolution and gain more flexibility when designing the data acquisition sequence...... and compared with the averaged periodogram (Welch’s method). The blood power spectral capon (BPC) method is based on a standard minimum variance technique adapted to account for both averaging over slow-time and depth. The blood amplitude and phase estimation technique (BAPES) is based on finding a set...

  19. Abatacept reduces disease activity and ultrasound power Doppler in ACPA-negative undifferentiated arthritis: a proof-of-concept clinical and imaging study.

    Science.gov (United States)

    Buch, Maya H; Hensor, Elizabeth M A; Rakieh, Chadi; Freeston, Jane E; Middleton, Edward; Horton, Sarah; Das, Sudipto; Peterfy, Charles; Tan, Ai Lyn; Wakefield, Richard J; Emery, Paul

    2017-01-01

    No proven treatment exists for ACPA-negative undifferentiated arthritis (UA). The aim of this study was to evaluate whether abatacept is effective in treating poor prognosis, ACPA-negative UA, including its effect on power Doppler on US (PDUS). A proof-of-concept, open-label, prospective study of 20 patients with DMARD-naïve, ACPA-negative UA (⩾2 joint synovitis) and PDUS ⩾ 1 with clinical and 20-joint US (grey scale/PDUS) assessments at baseline, 6, 12, 18 and 24 months. All patients received 12 months of abatacept (monotherapy for minimum first 6 months). The primary end point was a composite of the proportion of patients that at 6 months achieved DAS44 remission, a maximum of one swollen joint for at least 3 consecutive months and no radiographic progression (over 0-12 months). Twenty of the 23 patients screened were enrolled [14 female; mean (sd) age 53.4 (11.2) years, symptom duration 7.5 (0.9) months]. Two (10%) achieved the composite primary end point. A reduction in the mean (sd) DAS44 was observed from a baseline value of 2.66 (0.77) to 2.01 (0.81) at 6 months and to 1.78 (0.95) at 12 months. The DAS44 remission rates were 6/20 (30%; 95% CI: 15, 51%) at 6 months and 8/20 (40%; 95% CI: 22, 62%) at 12 months. A striking decrease in the median (interquartile range; IQR) total PDUS score was noted from 10 (4-23) at baseline to 3 (2-12) and 3 (0-5) at 6 and 12 months, respectively. This report is a first in potentially identifying an effective therapy, abatacept monotherapy, for poor-prognosis, ACPA-negative UA, supported by a clear reduction in PDUS. These data justify evaluation in a controlled study. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Quantum noise of a Michelson-Sagnac interferometer with a translucent mechanical oscillator

    International Nuclear Information System (INIS)

    Yamamoto, Kazuhiro; Friedrich, Daniel; Westphal, Tobias; Gossler, Stefan; Danzmann, Karsten; Schnabel, Roman; Somiya, Kentaro; Danilishin, Stefan L.

    2010-01-01

    Quantum fluctuations in the radiation pressure of light can excite stochastic motions of mechanical oscillators thereby realizing a linear quantum opto-mechanical coupling. When performing a precise measurement of the position of an oscillator, this coupling results in quantum radiation pressure noise. Up to now this effect has not been observed yet. Generally speaking, the strength of radiation pressure noise increases when the effective mass of the oscillator is decreased or when the power of the reflected light is increased. Recently, extremely light SiN membranes (≅100 ng) with high mechanical Q values at room temperature (≥10 6 ) have attracted attention as low thermal noise mechanical oscillators. However, the power reflectance of these membranes is much lower than unity (<0.4 at a wavelength of 1064 nm) which makes the use of advanced interferometer recycling techniques to amplify the radiation pressure noise in a standard Michelson interferometer inefficient. Here, we propose and theoretically analyze a Michelson-Sagnac interferometer that includes the membrane as a common end mirror for the Michelson interferometer part. In this topology, both power and signal recycling can be used even if the reflectance of the membrane is much lower than unity. In particular, signal recycling is a useful tool because it does not involve a power increase at the membrane. We derive the formulas for the quantum radiation pressure noise and the shot noise of an oscillator position measurement and compare them with theoretical models of the thermal noise of a SiN membrane with a fundamental resonant frequency of 75 kHz and an effective mass of125 ng. We find that quantum radiation pressure noise should be observable with a power of 1 W at the central beam splitter of the interferometer and a membrane temperature of 1 K.

  1. Einstein, the exponential metric, and a proposed gravitational Michelson-Morley experiment

    International Nuclear Information System (INIS)

    Yilmaz, H.

    1979-01-01

    An early but potentially important remark of Einstein on the exponential nature of time-dilation is discussed. Using the same argument for the length-contraction, plus two alternative kinematical assumptions, the Schwarzschild and exponential metrics are derived. A gravitational Michelson-Morley experiment with one arm directed along the vertical is proposed to test the metrics. The experiment may be considered as a laboratory test of the Schwarzschild field and possibly a test of the black-hole interpretation of collapsed matter

  2. First Measurements of High Frequency Cross-Spectra from a Pair of Large Michelson Interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Aaron S.; Gustafson, Richard; Hogan, Craig; Kamai, Brittany; Kwon, Ohkyung; Lanza, Robert; McCuller, Lee; Meyer, Stephan S.; Richardson, Jonathan; Stoughton, Chris; Tomlin, Raymond; Waldman, Samuel; Weiss, Rainer

    2016-09-01

    Measurements are reported of high frequency cross-spectra of signals from the Fermilab Holometer, a pair of co-located 39 m, high power Michelson interferometers. The instrument obtains differential position sensitivity to cross-correlated signals far exceeding any previous measurement in a broad frequency band extending to the 3.8 MHz inverse light crossing time of the apparatus. A model of universal exotic spatial shear correlations that matches the Planck scale holographic information bound of space-time position states is excluded to 4.6{\\sigma} significance.

  3. Analysis of a sub-shot-noise power recycled Michelson interferometer

    International Nuclear Information System (INIS)

    McKenzie, K; Buchler, B C; Shaddock, D A; Lam, P K; McClelland, D E

    2004-01-01

    The sensitivity of interferometric gravitational wave detectors is ultimately limited by the 'quantum noise' of light. In this paper we compare results from a bench-top experiment and a theoretical model which show how squeezed states of light may be used to modify the quantum noise behaviour of a power recycled Michelson interferometer. We develop a simple theoretical model of the experiment and find close agreement of theoretical and experimental results. We measure quantum noise suppression of 2.3 dB and demonstrate the lock stability of the experiment for long periods

  4. An ultrastable Michelson interferometer for high-resolution spectroscopy in the XUV.

    Science.gov (United States)

    Corsi, C; Liontos, I; Cavalieri, S; Bellini, M; Venturi, G; Eramo, R

    2015-02-23

    We developed an ultra-stable and accurately-controllable Michelson interferometer to be used in a deeply unbalanced arm configuration for split-pulse XUV Ramsey-type spectroscopy with high-order laser harmonics. The implemented active and passive stabilization systems allow one to reach instabilities in the nanometer range over meters of relative optical path differences. Producing precisely delayed pairs of pump pulses will generate XUV harmonic pulses that may significantly improve the achievable spectral resolution and the precision of absolute frequency measurements in the XUV.

  5. Correction of detector nonlinearity for the balloonborne Michelson Interferometer for Passive Atmospheric Sounding.

    Science.gov (United States)

    Kleinert, Anne

    2006-01-20

    The detectors used in the cryogenic limb-emission sounder MIPAS-B2 (Michelson Interferometer for Passive Atmospheric Sounding) show a nonlinear response, which leads to radiometric errors in the calibrated spectra if the nonlinearity is not taken into account. In the case of emission measurements, the dominant error that arises from the nonlinearity is the changing detector responsivity as the incident photon load changes. The effect of the distortion of a single interferogram can be neglected. A method to characterize the variable responsivity and to correct for this effect is proposed. Furthermore, a detailed error estimation is presented.

  6. Improvement on a Michelson interferometer for bunch length measurement of a femtosecond accelerator

    International Nuclear Information System (INIS)

    Lin Xuling; Bei Hua; Zhang Jianbing; Dai Zhimin

    2009-01-01

    Based on the femtosecond accelerator facility at Shanghai Institute of Applied Physics (SINAP), a conventional far-infrared Michelson interferometer was built to measure the bunch length by means of optical autocorrelation. However, according to the preliminary experiment result, the resolution of interferometer is not good enough, because the mirror-driving mechanism makes the moving mirror tend to tilt or wobble as it retards. Considering of the allowable errors, we calculate the maximum allowable titling angle of the moving mirror, and discuss the alignment plan in this paper. (authors)

  7. Correlated two-photon interference in a dual-beam Michelson interferometer

    International Nuclear Information System (INIS)

    Kwiat, P.G.; Vareka, W.A.; Hong, C.K.; Nathel, H.; Chiao, R.Y.

    1990-01-01

    We report on an interference effect arising from a two-photon entangled state produced in a potassium dihydrogen phosphate (KDP) crystal pumped by an ultraviolet argon-ion laser. Two conjugate beams of signal and idler photons were injected in a parallel configuration into a single Michelson interferometer, and detected separately by two photomultipliers, while the difference in its arm lengths was slowly scanned. The coincidence rate exhibited fringes with a visibility of nearly 50%, and a period given by half the ultraviolet (not the signal or idler) wavelength, while the singles rate exhibited no fringes

  8. Broadband squeezing of quantum noise in a Michelson interferometer with Twin-Signal-Recycling.

    Science.gov (United States)

    Thüring, André; Gräf, Christian; Vahlbruch, Henning; Mehmet, Moritz; Danzmann, Karsten; Schnabel, Roman

    2009-03-15

    Twin-Signal-Recycling (TSR) builds on the resonance doublet of two optically coupled cavities and efficiently enhances the sensitivity of an interferometer at a dedicated signal frequency. We report on what we believe to be the first experimental realization of a TSR Michelson interferometer and also its broadband enhancement by squeezed light injection. The complete setup was stably locked, and a broadband quantum noise reduction of the interferometers shot noise by a factor of up to 4 dB was demonstrated. The system was characterized by measuring its quantum noise spectra for several tunings of the TSR cavities. We found good agreement between the experimental results and numerical simulations.

  9. Active stabilization of a Michelson interferometer at an arbitrary phase with subnanometer resolution.

    Science.gov (United States)

    Grassani, Davide; Galli, Matteo; Bajoni, Daniele

    2014-04-15

    We report on the active stabilization of a Michelson interferometer at an arbitrary phase angle with a precision better than 1° at λ=632.8  nm, which corresponds to a precision in the optical path difference between the two arms of less than 1 nm. The stabilization method is ditherless, and the error signal is computed from the spatial shift of the interference pattern of a reference laser, measured in real-time with a CCD array detector. We discuss the usefulness of this method for nanopositioning, optical interferometry, and quantum optical experiments.

  10. Secondary wavelength stabilization of unbalanced Michelson interferometers for the generation of low-jitter pulse trains.

    Science.gov (United States)

    Shalloo, R J; Corner, L

    2016-09-01

    We present a double unbalanced Michelson interferometer producing up to four output pulses from a single input pulse. The interferometer is stabilized with the Hänsch-Couillaud method using an auxiliary low power continuous wave laser injected into the interferometer, allowing the stabilization of the temporal jitter of the output pulses to 0.02 fs. Such stabilized pulse trains would be suitable for driving multi-pulse laser wakefield accelerators, and the technique could be extended to include amplification in the arms of the interferometer.

  11. Active feedback regulation of a Michelson interferometer to achieve zero-background absorption measurements.

    Science.gov (United States)

    Lundin, Patrik; Guan, Zuguang; Svanberg, Sune

    2011-01-20

    An active phase-controlling scheme based on a proportional-integral-derivative-controlled piezoelectric transducer is presented with the purpose of stabilizing a quasi-zero-background absorption spectrometer. A fiber-based balanced Michelson interferometer is used, and absorption due to a gas sample in one of its arms results in an increased light signal to a detector, which otherwise, thanks to destructive interference, experiences a very low light level. With the presented approach, the sensitivity of already potent absorption measurement techniques, e.g., based on modulation, could be improved even further.

  12. Naked eye picometer resolution in a Michelson interferometer using conjugated twisted beams.

    Science.gov (United States)

    Emile, Olivier; Emile, Janine

    2017-01-15

    Michelson interferometry is one of the most widely used techniques for accuracy measurements. Its main characteristic feature is to infer a displacement in one of the arms of the interferometer from a phase measurement. Two different twisted beams, also called vortex beams, with opposite twisted rotations in each arm of the interferometer interfere in a daisy flower-like pattern. The number of petals is twice the topological charge. Their position depends on the relative phase of the beams. Naked eye detection of 44 pm displacements is achieved. The sensitivity of such an interferometer together with possible further improvements, and applications are then discussed.

  13. Adaption of the Michelson interferometer for a better understanding of the temporal coherence in lasers

    Science.gov (United States)

    Illarramendi, M. A.; Zubia, J.; Arrue, J.; Ayesta, I.

    2017-08-01

    In this work, we show a design of a laboratory exercise in which a digital camera has been coupled to a Michelson interferometer based on free-propagation arms. By using the camera, our students measure the evolution of the interference patterns as a function of the difference between the optical paths of the arms. In this way, they obtain the corresponding reduction of the contrast of the fringes. The analysis of the results allows one to calculate the coherence length, and also to relate the temporal coherence of the employed laser with its spectral line profile. The exercise has been carried out with two lasers, which present different coherence lengths.

  14. Atom Michelson interferometer on a chip using a Bose-Einstein condensate.

    Science.gov (United States)

    Wang, Ying-Ju; Anderson, Dana Z; Bright, Victor M; Cornell, Eric A; Diot, Quentin; Kishimoto, Tetsuo; Prentiss, Mara; Saravanan, R A; Segal, Stephen R; Wu, Saijun

    2005-03-11

    An atom Michelson interferometer is implemented on an "atom chip." The chip uses lithographically patterned conductors and external magnetic fields to produce and guide a Bose-Einstein condensate. Splitting, reflecting, and recombining of condensate atoms are achieved by a standing-wave light field having a wave vector aligned along the atom waveguide. A differential phase shift between the two arms of the interferometer is introduced by either a magnetic-field gradient or with an initial condensate velocity. Interference contrast is still observable at 20% with an atom propagation time of 10 ms.

  15. Michelson interferometer with separated inputs and outputs, double pass, and compensation

    Science.gov (United States)

    Mather, J. C.; Jennings, D. E.

    1985-01-01

    A novel configuration is proposed for a Michelson interferometer spectrometer, which will be insensitive to tilts or displacements, and which employs separated inputs and outputs and double passing for higher resolution. The great advantage of such a compensated design is a relaxation of mechanical tolerances, which is especially beneficial for instruments in hostile environments. The Atmospheric Trace Molecule Spectroscopy project, which must work reliably after being subjected to the vibrations of a Space Shuttle launch, would benefit from the use of such an instrument.

  16. Atom Michelson interferometer on a chip using a Bose-Einstein condensate

    International Nuclear Information System (INIS)

    Wang Yingju; Anderson, Dana Z.; Cornell, Eric A.; Diot, Quentin; Kishimoto, Tetsuo; Segal, Stephen R.; Bright, Victor M.; Saravanan, R.A.; Prentiss, Mara; Wu Saijun

    2005-01-01

    An atom Michelson interferometer is implemented on an 'atom chip'. The chip uses lithographically patterned conductors and external magnetic fields to produce and guide a Bose-Einstein condensate. Splitting, reflecting, and recombining of condensate atoms are achieved by a standing-wave light field having a wave vector aligned along the atom waveguide. A differential phase shift between the two arms of the interferometer is introduced by either a magnetic-field gradient or with an initial condensate velocity. Interference contrast is still observable at 20% with an atom propagation time of 10 ms

  17. Fast and low power Michelson interferometer thermo-optical switch on SOI.

    Science.gov (United States)

    Song, Junfeng; Fang, Q; Tao, S H; Liow, T Y; Yu, M B; Lo, G Q; Kwong, D L

    2008-09-29

    We designed and fabricated silicon-on-insulator based Michelson interferometer (MI) thermo-optical switches with deep etched trenches for heat-isolation. Switch power was reduced approximately 20% for the switch with deep etched trenches, and the MI saved approximately 50% power than that of the Mach-Zehnder interferometer. 10.6 mW switch power, approximately 42 micros switch time for the MI with deep trenches, 13.14 mW switch power and approximately 34 micros switch time for the MI without deep trenches were achieved.

  18. Measuring the separation of the sodium D-doublet with a Michelson interferometer

    Science.gov (United States)

    D'Anna, M.; Corridoni, T.

    2018-01-01

    Revisiting a method proposed by Fizeau in 1862, in this paper we measure the separation of the Na-doublet (the wavelength difference {{Δ }}λ between the two emission D-lines of the sodium spectrum) with a didactical Michelson interferometer. We describe the setup, how the measurements have been done and develop a mathematical model in order to explain the principal features of the collected data. Discussing the limits of this model, we suggest further experimental and theoretical extensions of the experience, also focusing on the didactical aspects to show how this experiment could bring advanced modern physics topics into high schools.

  19. Displacement measurement using an optoelectronic oscillator with an intra-loop Michelson interferometer.

    Science.gov (United States)

    Lee, Jehyun; Park, Sooyoung; Seo, Dae Han; Yim, Sin Hyuk; Yoon, Seokchan; Cho, D

    2016-09-19

    We report on measurement of small displacements with sub-nanometer precision using an optoelectronic oscillator (OEO) with an intra-loop Michelson interferometer. In comparison with conventional homodyne and heterodyne detection methods, where displacement appears as a power change or a phase shift, respectively, in the OEO detection, the displacement produces a shift in the oscillation frequency. In comparison with typical OEO sensors, where the frequency shift is proportional to the OEO oscillation frequency in radio-frequency domain, the frequency shift in our method with an intra-loop interferometer is proportional to an optical frequency. We constructed a hybrid apparatus and compared characteristics of the OEO and heterodyne detection methods.

  20. Right heart function in impaired left ventricular diastolic function: 2D speckle tracking echocardiography-based and Doppler tissue imaging-based analysis of right atrial and ventricular function.

    Science.gov (United States)

    Brand, Anna; Bathe, Marny; Oertelt-Prigione, Sabine; Seeland, Ute; Rücke, Mirjam; Regitz-Zagrosek, Vera; Stangl, Karl; Knebel, Fabian; Stangl, Verena; Dreger, Henryk

    2018-01-01

    The aim of our study was to describe right atrial (RA) and right ventricular (RV) function, assessed by Doppler tissue imaging and 2D speckle tracking echocardiography (2DSTE), in women with signs of early impaired left ventricular diastolic function (DD). In a cross-sectional trial, standard parameters of diastolic and right heart function were investigated in 438 women of the Berlin Female Risk Evaluation (BEFRI) study. In a subset of women, average peak systolic RA strain (RAS), as well as the average peak systolic RV strain of the free wall (RVS free wall) and of all RV segments (average RV strain; RVS Avg), was analyzed using 2DSTE. Compared to women with normal diastolic function (DD0), RAS, RVS free wall and RVS Avg were significantly reduced in DD (43.1% ± 11.9%, -26.7% ± 5.6%, and -23.3% ± 3.5% in DD0; vs 35.1% ± 10.4%, -23.9% ± 5.5%, and -20.6% ± 3.8% in DD; P right heart function is significantly altered in DD. DTI as well as 2DSTE constitute sensitive echocardiographic tools that enable the diagnosis of impaired right heart mechanics in early-staged DD. © 2017 Wiley Periodicals, Inc.

  1. Preoperative Diagnosis of Fallopian Tube Malignancy with Transvaginal Color Doppler Ultrasonography and Magnetic Resonance Imaging after Negative Hysteroscopy for Postmenopausal Bleedin

    OpenAIRE

    Arko, Darja; Žegura, Branka; Virag, Mirjana; Fokter Dovnik, Nina; Takač, Iztok

    2014-01-01

    Primary Fallopian tube carcinoma is a rare malignancy and is not often diagnosed preoperatively. We present a case of a 67-year old woman who complained of postmenopausal vaginal bleeding. After a negative hysteroscopy, transvaginal ultrasound showed a well vascularized solid-cystic tumor in the adnexal region separate from the ovary. The presence of an adnexal mass was confirmed by MR imaging. Total abdominal hysterectomy with bilateral salpingoophorectomy, omentectomy and appendectomy, as w...

  2. Physical interpretation of the fringe shift measured on Michelson interferometer in optical media

    International Nuclear Information System (INIS)

    Demjanov, V.V.

    2010-01-01

    The shift of the interference fringe in the Michelson interferometer is absent in vacuum but present in measurements performed in dielectric media with the refractive index greater than unity. This experimental observation induced me to interpret physical processes occurred in the Michelson interferometer in a conceptually new way. I rejected the generally accepted additive rule c±v for composition of the velocity v of the inertial body and the speed c of light as inapplicable in principle to non-inertial objects which electromagnetic waves just belong to. I used instead the non-relativistic formula of Fresnel for drag of light by a moving optical medium. This formula, and taking into account the physical effect of Lorentz contraction of the arm of interferometer, enabled me to construct the theoretical model that reproduces in essential features the parabolic dependence of the shift of the interference fringe on the dielectric permittivity of the light-carrying material. The Earth's speed relative to aether found from the experimental curve was estimated as 140-480 km/s. The range of the values refers to the projection of the speed on the horizontal plane of the experimental setup measured at various time of day and night.

  3. Field-widened Michelson interferometer for spectral discrimination in high-spectral-resolution lidar: theoretical framework.

    Science.gov (United States)

    Cheng, Zhongtao; Liu, Dong; Luo, Jing; Yang, Yongying; Zhou, Yudi; Zhang, Yupeng; Duan, Lulin; Su, Lin; Yang, Liming; Shen, Yibing; Wang, Kaiwei; Bai, Jian

    2015-05-04

    A field-widened Michelson interferometer (FWMI) is developed to act as the spectral discriminator in high-spectral-resolution lidar (HSRL). This realization is motivated by the wide-angle Michelson interferometer (WAMI) which has been used broadly in the atmospheric wind and temperature detection. This paper describes an independent theoretical framework about the application of the FWMI in HSRL for the first time. In the framework, the operation principles and application requirements of the FWMI are discussed in comparison with that of the WAMI. Theoretical foundations for designing this type of interferometer are introduced based on these comparisons. Moreover, a general performance estimation model for the FWMI is established, which can provide common guidelines for the performance budget and evaluation of the FWMI in the both design and operation stages. Examples incorporating many practical imperfections or conditions that may degrade the performance of the FWMI are given to illustrate the implementation of the modeling. This theoretical framework presents a complete and powerful tool for solving most of theoretical or engineering problems encountered in the FWMI application, including the designing, parameter calibration, prior performance budget, posterior performance estimation, and so on. It will be a valuable contribution to the lidar community to develop a new generation of HSRLs based on the FWMI spectroscopic filter.

  4. Electron cyclotron emission measurements on JET: Michelson interferometer, new absolute calibration, and determination of electron temperature.

    Science.gov (United States)

    Schmuck, S; Fessey, J; Gerbaud, T; Alper, B; Beurskens, M N A; de la Luna, E; Sirinelli, A; Zerbini, M

    2012-12-01

    At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70-500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron temperature is determined from the measurements. The current state of the interferometer hardware, the calibration setup, and the analysis technique for calibration and plasma operation are described. A new, full-system, absolute calibration employing continuous data acquisition has been performed recently and the calibration method and results are presented. The noise level in the measurement is very low and as a result the electron cyclotron emission spectrum and thus the spatial profile of the electron temperature are determined to within ±5% and in the most relevant region to within ±2%. The new calibration shows that the absolute response of the system has decreased by about 15% compared to that measured previously and possible reasons for this change are presented. Temperature profiles measured with the Michelson interferometer are compared with profiles measured independently using Thomson scattering diagnostics, which have also been recently refurbished and recalibrated, and agreement within experimental uncertainties is obtained.

  5. Transversal Doppler-Fizeau effect

    International Nuclear Information System (INIS)

    Subacius, E.

    1981-01-01

    The relativistic calculation of the Doppler-Fizeau effect foresees a second grade redshift due to the proper time dilation of a moving object. The relevance of this relativistic effect on astrophysical observation is discussed, herein. (Auhor) [pt

  6. Dual-Doppler Feasibility Study

    Science.gov (United States)

    Huddleston, Lisa L.

    2012-01-01

    When two or more Doppler weather radar systems are monitoring the same region, the Doppler velocities can be combined to form a three-dimensional (3-D) wind vector field thus providing for a more intuitive analysis of the wind field. A real-time display of the 3-D winds can assist forecasters in predicting the onset of convection and severe weather. The data can also be used to initialize local numerical weather prediction models. Two operational Doppler Radar systems are in the vicinity of Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS); these systems are operated by the 45th Space Wing (45 SW) and the National Weather Service Melbourne, Fla. (NWS MLB). Dual-Doppler applications were considered by the 45 SW in choosing the site for the new radar. Accordingly, the 45th Weather Squadron (45 WS), NWS MLB and the National Aeronautics and Space Administration tasked the Applied Meteorology Unit (AMU) to investigate the feasibility of establishing dual-Doppler capability using the two existing systems. This study investigated technical, hardware, and software requirements necessary to enable the establishment of a dual-Doppler capability. Review of the available literature pertaining to the dual-Doppler technique and consultation with experts revealed that the physical locations and resulting beam crossing angles of the 45 SW and NWS MLB radars make them ideally suited for a dual-Doppler capability. The dual-Doppler equations were derived to facilitate complete understanding of dual-Doppler synthesis; to determine the technical information requirements; and to determine the components of wind velocity from the equation of continuity and radial velocity data collected by the two Doppler radars. Analysis confirmed the suitability of the existing systems to provide the desired capability. In addition, it is possible that both 45 SW radar data and Terminal Doppler Weather Radar data from Orlando International Airport could be used to alleviate any

  7. Glare Spot Phase Doppler Anemometry

    OpenAIRE

    Hespel, Camille; Ren, Kuan Fang; Gréhan, Gérard; Onofri, Fabrice

    2006-01-01

    International audience; The Phase Doppler anemometry has been developed to measure simultaneously the velocity and the size of droplets. The measurement of the refractive index is also necessary since it depends on the temperature and the composition of the particle and its measurement permits both to increase the quality of the diameter measurement and to obtain information on the temperature and/or the composition of the droplets. In this paper, we introduce a Glare Spot Phase Doppler Anemo...

  8. Preoperative diagnosis of fallopian tube malignancy with transvaginal color doppler ultrasonography and magnetic resonance imaging after negative hysteroscopy for postmenopausal bleeding.

    Science.gov (United States)

    Arko, Darja; Žegura, Branka; Virag, Mirjana; Fokter Dovnik, Nina; Takač, Iztok

    2014-09-01

    Primary fallopian tube carcinoma is a rare malignancy and is not often diagnosed preoperatively. We present a case of a 67-year-old woman who complained of postmenopausal vaginal bleeding. After a negative hysteroscopy, transvaginal ultrasound showed a well vascularized solid-cystic tumor in the adnexal region separate from the ovary. The presence of an adnexal mass was confirmed by MR imaging. Total abdominal hysterectomy with bilateral salpingoophorectomy, omentectomy and appendectomy, as well as pelvic and paraaortic lymphadenectomy was performed. The pathohistological diagnosis was poorly differentiated serous adenocarcinoma of the fallopian tube, FIGO stage IA. The patient was subsequently treated with platinum based adjuvant chemotherapy.

  9. Temporal enhancement of two-dimensional color doppler echocardiography

    Science.gov (United States)

    Terentjev, Alexey B.; Settlemier, Scott H.; Perrin, Douglas P.; del Nido, Pedro J.; Shturts, Igor V.; Vasilyev, Nikolay V.

    2016-03-01

    Two-dimensional color Doppler echocardiography is widely used for assessing blood flow inside the heart and blood vessels. Currently, frame acquisition time for this method varies from tens to hundreds of milliseconds, depending on Doppler sector parameters. This leads to low frame rates of resulting video sequences equal to tens of Hz, which is insufficient for some diagnostic purposes, especially in pediatrics. In this paper, we present a new approach for reconstruction of 2D color Doppler cardiac images, which results in the frame rate being increased to hundreds of Hz. This approach relies on a modified method of frame reordering originally applied to real-time 3D echocardiography. There are no previous publications describing application of this method to 2D Color Doppler data. The approach has been tested on several in-vivo cardiac 2D color Doppler datasets with approximate duration of 30 sec and native frame rate of 15 Hz. The resulting image sequences had equivalent frame rates to 500Hz.

  10. Gold nanorods as a contrast agent for Doppler optical coherence tomography.

    Directory of Open Access Journals (Sweden)

    Bo Wang

    Full Text Available To investigate gold nanorods (GNRs as a contrast agent to enhance Doppler optical coherence tomography (OCT imaging of the intrascleral aqueous humor outflow.A serial dilution of GNRs was scanned with a spectral-domain OCT device (Bioptigen, Durham, NC to visualize Doppler signal. Doppler measurements using GNRs were validated using a controlled flow system. To demonstrate an application of GNR enhanced Doppler, porcine eyes were perfused at constant pressure with mock aqueous alone or 1.0×10(12 GNR/mL mixed with mock aqueous. Twelve Doppler and volumetric SD-OCT scans were obtained from the limbus in a radial fashion incremented by 30°, forming a circular scan pattern. Volumetric flow was computed by integrating flow inside non-connected vessels throughout all 12 scans around the limbus.At the GNR concentration of 0.7×10(12 GNRs/mL, Doppler signal was present through the entire depth of the testing tube without substantial attenuation. A well-defined laminar flow profile was observed for Doppler images of GNRs flowing through the glass capillary tube. The Doppler OCT measured flow profile was not statistically different from the expected flow profile based upon an autoregressive moving average model, with an error of -0.025 to 0.037 mm/s (p = 0.6435. Cross-sectional slices demonstrated the ability to view anterior chamber outflow ex-vivo using GNR-enhanced Doppler OCT. Doppler volumetric flow measurements were comparable to flow recorded by the perfusion system.GNRs created a measureable Doppler signal within otherwise silent flow fields in OCT Doppler scans. Practical application of this technique was confirmed in a constant pressure ex-vivo aqueous humor outflow model in porcine eyes.

  11. Power and color Doppler ultrasound settings for inflammatory flow: impact on scoring of disease activity in patients with rheumatoid arthritis.

    Science.gov (United States)

    Torp-Pedersen, Søren; Christensen, Robin; Szkudlarek, Marcin; Ellegaard, Karen; D'Agostino, Maria Antonietta; Iagnocco, Annamaria; Naredo, Esperanza; Balint, Peter; Wakefield, Richard J; Torp-Pedersen, Arendse; Terslev, Lene

    2015-02-01

    To determine how settings for power and color Doppler ultrasound sensitivity vary on different high- and intermediate-range ultrasound machines and to evaluate the impact of these changes on Doppler scoring of inflamed joints. Six different types of ultrasound machines were used. On each machine, the factory setting for superficial musculoskeletal scanning was used unchanged for both color and power Doppler modalities. The settings were then adjusted for increased Doppler sensitivity, and these settings were designated study settings. Eleven patients with rheumatoid arthritis (RA) with wrist involvement were scanned on the 6 machines, each with 4 settings, generating 264 Doppler images for scoring and color quantification. Doppler sensitivity was measured with a quantitative assessment of Doppler activity: color fraction. Higher color fraction indicated higher sensitivity. Power Doppler was more sensitive on half of the machines, whereas color Doppler was more sensitive on the other half, using both factory settings and study settings. There was an average increase in Doppler sensitivity, despite modality, of 78% when study settings were applied. Over the 6 machines, 2 Doppler modalities, and 2 settings, the grades for each of 7 of the patients varied between 0 and 3, while the grades for each of the other 4 patients varied between 0 and 2. The effect of using different machines, Doppler modalities, and settings has a considerable influence on the quantification of inflammation by ultrasound in RA patients, and this must be taken into account in multicenter studies. Copyright © 2015 by the American College of Rheumatology.

  12. The comparison of environmental effects on michelson and fabry-perot interferometers utilized for the displacement measurement.

    Science.gov (United States)

    Wang, Yung-Cheng; Shyu, Lih-Horng; Chang, Chung-Ping

    2010-01-01

    The optical structure of general commercial interferometers, e.g., the Michelson interferometers, is based on a non-common optical path. Such interferometers suffer from environmental effects because of the different phase changes induced in different optical paths and consequently the measurement precision will be significantly influenced by tiny variations of the environmental conditions. Fabry-Perot interferometers, which feature common optical paths, are insensitive to environmental disturbances. That would be advantageous for precision displacement measurements under ordinary environmental conditions. To verify and analyze this influence, displacement measurements with the two types of interferometers, i.e., a self-fabricated Fabry-Perot interferometer and a commercial Michelson interferometer, have been performed and compared under various environmental disturbance scenarios. Under several test conditions, the self-fabricated Fabry-Perot interferometer was obviously less sensitive to environmental disturbances than a commercial Michelson interferometer. Experimental results have shown that induced errors from environmental disturbances in a Fabry-Perot interferometer are one fifth of those in a Michelson interferometer. This has proved that an interferometer with the common optical path structure will be much more independent of environmental disturbances than those with a non-common optical path structure. It would be beneficial for the solution of interferometers utilized for precision displacement measurements in ordinary measurement environments.

  13. Application of Young-Michelson and Brown-Twiss interferometers for determining geometric parameters of nonplanar rough objects

    NARCIS (Netherlands)

    Mandrosov, V. I.

    The possibility of using Young-Michelson and Brown-Twiss interferometers for measuring the angular dimensions and parameters of the surface shape of remote passively scattering and self-luminous nonplanar rough objects by optical radiation propagating from them is substantiated. The analysis is

  14. The use of balanced homodyne and squeezed states for detecting weak optical signals in a Michelson interferometer

    International Nuclear Information System (INIS)

    Ben-Aryeh, Y.

    2011-01-01

    The possibility of using squeezed states and balanced homodyne detection of optical signals in a Michelson interferometer is discussed. The present analysis describes photon statistics measurements effects related to quadrature balanced homodyne detection showing the advantage of using this scheme for detecting weak optical signals.

  15. A bit-rate flexible and power efficient all-optical demultiplexer realised by monolithically integrated Michelson interferometer

    DEFF Research Database (Denmark)

    Vaa, Michael; Mikkelsen, Benny; Jepsen, Kim Stokholm

    1996-01-01

    A novel bit-rate flexible and very power efficient all-optical demultiplexer using differential optical control of a monolithically integrated Michelson interferometer with MQW SOAs is demonstrated at 40 to 10 Gbit/s. Gain switched DFB lasers provide ultra stable data and control signals....

  16. Color Doppler Echocardiographic Assessment of Valvular Regurgitation in Normal Infants

    Directory of Open Access Journals (Sweden)

    Shu-Ting Lee

    2010-01-01

    Conclusion: The prevalence of inaudible valvular regurgitation is high in infants with structurally normal hearts. Multiple-valve involvement with regurgitation is not uncommon. Mild severity and low velocity on color Doppler, and the structural information provided by 2D imaging strongly suggest that these regurgitant flows are physiologically normal in infancy.

  17. Language Lateralization in Children Using Functional Transcranial Doppler Sonography

    Science.gov (United States)

    Haag, Anja; Moeller, Nicola; Knake, Susanne; Hermsen, Anke; Oertel, Wolfgang H.; Rosenow, Felix; Hamer, Hajo M.

    2010-01-01

    Aim: Language lateralization with functional transcranial Doppler sonography (fTCD) and lexical word generation has been shown to have high concordance with the Wada test and functional magnetic resonance imaging in adults. We evaluated a nonlexical paradigm to determine language dominance in children. Method: In 23 right-handed children (12…

  18. Children's (Pediatric) Abdominal Ultrasound Imaging

    Medline Plus

    Full Text Available ... placement and fluid drainage for diagnosis and/or relief of patient discomfort. Doppler ultrasound images can help ... tenderness, your child may feel pressure or minor pain from the procedure. If a Doppler ultrasound study ...

  19. Analysis of multiple scattering effects in optical Doppler tomography

    DEFF Research Database (Denmark)

    Yura, H.T.; Thrane, L.; Andersen, Peter E.

    2005-01-01

    Optical Doppler tomography (ODT) combines Doppler velocimetry and optical coherence tomography (OCT) to obtain high-resolution cross-sectional imaging of particle flow velocity in scattering media such as the human retina and skin. Here, we present the results of a theoretical analysis of ODT where...... multiple scattering effects are included. The purpose of this analysis is to determine how multiple scattering affects the estimation of the depth-resolved localized flow velocity. Depth-resolved velocity estimates are obtained directly from the corresponding mean or standard deviation of the observed...

  20. Estimation of diastolic filling pressure with cardiac CT in comparison with echocardiography using tissue doppler imaging: Determination of optimal CT reconstruction parameters

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ji Sun; Suh, Jon; Lee, Heon [Soonchunhyang University Hospital Bucheon, Bucheon (Korea, Republic of); Lee, Bora [Dept. of Biostatistics, Soonchunhyang University College of Medicine, Seoul (Korea, Republic of); Lee, Soo Jeong [Terarecon Korea, Seoul (Korea, Republic of); Jou, Sung Shick [Dept. of Radiology, Soonchunhyang University Hospital Cheonan, Cheonan (Korea, Republic of); Lim, Hyun Kyung [Dept. of Radiology, Soonchunhyang University Hospital Seoul, Seoul (Korea, Republic of)

    2017-08-01

    To determine the optimal CT image reconstruction parameters for the measurement of early transmitral peak velocity (E), early peak mitral septal tissue velocity (E′), and E / E′. Forty-six patients underwent simultaneous cardiac CT and echocardiography on the same day. Four CT datasets were reconstructed with a slice thickness/interval of 0.9/0.9 mm or 3/3 mm at 10 (10% RR-interval) or 20 (5% RR-interval) RR-intervals. The E was calculated by dividing the peak transmitral flow (mL/s) by the corresponding mitral valve area (cm{sup 2}). E′ was calculated from the changes in the left ventricular length per cardiac phase. E / E′ was then estimated and compared with that from echocardiography. For assessment of E / E′, CT and echocardiography were more strongly correlated (p < 0.05) with a slice thickness of 0.9 mm and 5% RR-interval (r = 0.77) than with 3 mm or 10% RR-interval. The diagnostic accuracy of predicting elevated filling pressure (E / E′ ≥ 13, n = 14) was better with a slice thickness of 0.9 mm and 5% RR-interval (87.0%) than with 0.9 mm and 10% RR-interval (71.7%) (p = 0.123) and significantly higher than that with a slice thickness of 3 mm with 5% (67.4%) and 10% RR-interval (63.0%), (p < 0.05), respectively. Data reconstruction with a slice thickness of 0.9 mm at 5% RR-interval is superior to that with a slice thickness of 3 mm or 10% RR-interval in terms of the correlation of E / E′ between CT and echocardiography. Thin slices and frequent sampling also allow for more accurate prediction of elevated filling pressure.

  1. THE DIAGNOSTIC VALUE OF PULSED WAVE TISSUE DOPPLER IMAGING IN ASYMPTOMATIC BETA- THALASSEMIA MAJOR CHILDREN AND YOUNG ADULTS ; RELATION TO CHEMICAL BIOMARKERS OF LEFT VENTRICULAR FUNCTION AND IRON OVERLOAD .

    Directory of Open Access Journals (Sweden)

    Seham Ragab

    2015-08-01

    Full Text Available Background: Cardiac iron toxicity is the leading cause of death among  β-halassaemia major (TM  patients.  Once  heart failure becomes overt , it will be  difficult to reverse . Objectives: To investigate non overt cardiac dysfunctions  in TM patients using  pulsed wave Tissue Doppler  Imaging (TD I and its relation to the iron overload and brain natruritic peptide (BNP. Methods: Thorough  clinical , conventional echo and  pulsed  wave TDI  parameters were compared between  asymtomatic 25 β-TM  patients  and 20 age and gender matched individuals. Serum ferritin and plasma BNP  levels were assayed by  ELISA .  Results: TM patients had significant higher mitral inflow early diastolic (E wave and  non significant other conventional echo  parameters. Pulsed wave TDI revealed systolic and diastolic dysfunctions in the form of significant higher  isovolumetric contraction time (ICT , ejection time ( E T and  isovolumetric relaxation time (IRT with significantly lower  mitral annulus  early diastolic velocity E` (12.07 ±2.06 vs 15.04±2.65 ,P= 0.003  in patients compared to  controls. Plasma BNP was higher in patients compared to the controls.  Plasma BNP and serum ferritin had significant correlation with each other and with pulsed wave conventional and TDI indices of systolic and diastolic functions.  Patients with E/E` ≥ 8 had  significant higher  serum ferritin  and plasma BNP levels compared to those with E/E` ratio < 8 without difference in Hb levels .Conclusion:  Pulsed wave TDI  is an  important diagnostic tool for latent cardiac dysfunction in iron loaded TM patients and is related to iron overload and BNP .

  2. Value of tissue Doppler-derived Tei index and two-dimensional speckle tracking imaging derived longitudinal strain on predicting outcome of patients with light-chain cardiac amyloidosis.

    Science.gov (United States)

    Liu, Dan; Hu, Kai; Herrmann, Sebastian; Cikes, Maja; Ertl, Georg; Weidemann, Frank; Störk, Stefan; Nordbeck, Peter

    2017-06-01

    Prognosis of patients with light-chain cardiac amyloidosis (AL-CA) is poor. Speckle tracking imaging (STI) derived longitudinal deformation parameters and Doppler-derived left ventricular (LV) Tei index are valuable predictors of outcome in patients with AL-CA. We estimated the prognostic utility of Tei index and deformation parameters in 58 comprehensively phenotyped patients with AL-CA after a median follow-up of 365 days (quartiles 121, 365 days). The primary end point was all-cause mortality. 19 (33%) patients died during follow-up. Tei index (0.89 ± 0.29 vs. 0.61 ± 0.16, p < 0.001) and E to global early diastolic strain rate ratio (E/GLSR dias ) were higher while global longitudinal systolic strain (GLS sys ) was lower in non-survivors than in survivors (all p < 0.05). Tei index, NYHA functional class, GLS sys and E/GLSR dias were independent predictors of all-cause mortality risk, and Tei index ≥0.9 (HR 7.01, 95% CI 2.43-20.21, p < 0.001) was the best predictor of poor outcome. Combining Tei index and GLS sys yielded the best results on predicting death within 1 year (100% with Tei index ≥0.9 and GLS sys ≤13%) or survival (95% with Tei index ≤0.9 and GLS sys ≥13%). We conclude that 1-year mortality risk in AL-CA patients can be reliably predicted using Tei index or deformation parameters, with combined analysis offering best performance.

  3. The Diagnostic Value of Pulsed Wave Tissue Doppler Imaging in Asymptomatic Beta- Thalassemia Major Children and Young Adults; Relation to Chemical Biomarkers of Left Ventricular Function and Iron Overload.

    Science.gov (United States)

    Ragab, Seham M; Fathy, Waleed M; El-Aziz, Walaa FAbd; Helal, Rasha T

    2015-01-01

    Cardiac iron toxicity is the leading cause of death among β-halassaemia major (TM) patients. Once heart failure becomes overt, it is difficult to reverse. To investigate non-overt cardiac dysfunctions in TM patients using pulsed wave Tissue Doppler Imaging (TD I) and its relation to iron overload and brain natriuretic peptide (BNP). Thorough clinical, conventional echo and pulsed wave TDI parameters were compared between asymptomatic 25 β-TM patients and 20 age and gender matched individuals. Serum ferritin and plasma BNP levels were assayed by ELISA. TM patients had significant higher mitral inflow early diastolic (E) wave and non significant other conventional echo parameters. In the patient group, pulsed wave TDI revealed systolic dysfunctions, in the form of significant higher isovolumetric contraction time (ICT), and lower ejection time (E T), with diastolic dysfunction in the form of higher isovolumetric relaxation time (IRT), and lower mitral annulus early diastolic velocity E' (12.07 ±2.06 vs 15.04±2.65, P= 0.003) compared to the controls. Plasma BNP was higher in patients compared to the controls. Plasma BNP and serum ferritin had a significant correlation with each other and with pulsed wave conventional and TDI indices of systolic and diastolic functions. Patients with E/E' ≥ 8 had significant higher serum ferritin and plasma BNP levels compared to those with ratio wave TDI is an important diagnostic tool for latent cardiac dysfunction in iron-loaded TM patients and is related to iron overload and BNP.

  4. Studies of Gravity Waves Using Michelson Interferometer Measurements of OH (3-1) Bands

    Science.gov (United States)

    Won, Young-In; Cho, Young-Min; Lee, Bang Yong; Kim, J.

    2001-06-01

    As part of a long-term program for polar upper atmospheric studies, temperatures and intensities of the OH (3-1) bands were derived from spectrometric observations of airglow emissions over King Sejong station (62.22o S, 301.25o E). These measurements were made with a Michelson interferometer to cover wavelength regions between 1000 nm and 2000 nm. A spectral analysis was performed to individual nights of data to acquire information on the waves in the upper mesosphere/lower thermosphere. It is assumed that the measured fluctuations in the intensity and temperature of the OH (3-1) airglow were caused by gravity waves propagating through the emission layer. Correlation of intensity and temperature variation revealed oscillations with periods ranging from 2 to 9 hours. We also calculated Krassovsky's parameter and compared with published values.

  5. Studies of Gravity Waves Using Michelson Interferometer Measurements of OH (3-1 Bands

    Directory of Open Access Journals (Sweden)

    Young-In Won

    2001-06-01

    Full Text Available As part of a long-term program for polar upper atmospheric studies, temperatures and intensities of the OH (3-1 bands were derived from spectrometric observations of airglow emissions over King Sejong station (62.22o S, 301.25o E. These measurements were made with a Michelson interferometer to cover wavelength regions between 1000 nm and 2000 nm. A spectral analysis was performed to individual nights of data to acquire information on the waves in the upper mesosphere/lower thermosphere. It is assumed that the measured fluctuations in the intensity and temperature of the OH (3-1 airglow were caused by gravity waves propagating through the emission layer. Correlation of intensity and temperature variation revealed oscillations with periods ranging from 2 to 9 hours. We also calculated Krassovsky's parameter and compared with published values.

  6. Observations of OH(3,1) airglow emission using a Michelson interferometer at 62° S

    Science.gov (United States)

    Won, Young-In; Cho, Young-Min; Niciejewski, Rick J.; Kim, Jhoon

    A Michelson interferometer was used to observe the hydroxyl (OH) emission in the upper mesosphere at the King Sejong Station (62.22° S, 301.25° E), Antarctica. The instrument was installed in February 1999 and has been in routine operation since then. An intensive operational effort has resulted in a substantial data set between April and June, 1999. A spectral analysis was performed on individual data to examine the information of dominant waves. A harmonic analysis was also carried out on the monthly average data to investigate the characteristics of the major low frequency oscillations. The 12-hr temperature oscillations exhibit a striking agreement with a theoretical tidal model, supporting the tidal (migrating) origin. The 8-hr wave is found to be persistent and dominant, reflecting its major role in the upper mesospheric dynamics at the given latitude. The 6-hr oscillation is observed only in May with its value close to the prediction for zonally symmetric tides.

  7. A reliable, compact and low-cost Michelson wavemeter for laser wavelength measurement

    International Nuclear Information System (INIS)

    Fox, P.J.; Scholten, R.E.; Walkiewicz, M.R.; Drullinger, R.E.

    1998-01-01

    We describe the construction and operation of a simple, compact and cost effective Michelson wavemeter with picometer accuracy. The low cost of the device means that it can form the basis of an undergraduate laboratory experiment, yet it is sufficiently reliable and accurate that it has become an important tool in our research laboratory, where it is regularly used to tune lasers to atomic transitions. The usefulness and accuracy of the wavemeter is demonstrated by tuning two separate extended cavity diode lasers to achieve two-step excitation of the Rb 5 2 D state, observed by detecting 420 nm blue fluorescence from the 5 2 D → 6 2 P → 5 2 S decay path. (authors)

  8. Performance of a Rapid-Scan Vacuum Michelson Interferometer at the NSLS

    International Nuclear Information System (INIS)

    Brierly, P.; Dumas, P.; Smith, M.; Williams, G.P.

    2001-01-01

    A commercial Nicolet Magna series rapid-scan Michelson Fourier Transform Infrared (FTIR) was installed in a vacuum housing and integrated into the U4IR beamline at the National Synchrotron Light Source at Brookhaven National Laboratory. The frequency reference laser was mounted outside vacuum, but the moving mirror mechanism and the dynamic alignment system for the fixed mirror were in vacuum. The performance of the instrument was measured in the usual way by measuring the repeatability of data collected under specific conditions of aperture, resolution and mirror scanning velocity. We briefly discuss the beamline design, to put the interferometer in context, then present signal to noise data which we discuss in terms of both instrument performance and also storage ring stability. Under optimal conditions, the instrument has a reproducibility of 0.01% in 1 minute of measuring time at a resolution of 2 cmss, -1 , over a range from 100-3000 cm -1

  9. Improved operation of the Michelson interferometer electron cyclotron emission diagnostic on DIII-D

    International Nuclear Information System (INIS)

    Austin, M.E.; Ellis, R.F.; Doane, J.L.; James, R.A.

    1997-01-01

    The measurement of accurate temperature profiles is critical for transport analysis and equilibrium reconstruction in the DIII-D tokamak. Recent refinements in the Michelson interferometer diagnostic have produced more precise electron temperature measurements from electron cyclotron emission and made them available for a wider range of discharge conditions. Replacement of a lens-relay with a low-loss corrugated waveguide transmission system resulted in an increase in throughput of 6 dB and a reduction of calibration error from 15% to 5%. The waveguide exhibits a small polarization scrambling fraction of 0.05 at the quarter-wavelength frequency and very stable transmission characteristics over time. Further reduction in error was realized through special signal processing of the calibration and plasma interferograms. copyright 1997 American Institute of Physics

  10. Quantum mechanical noise in coherent-state and squeezed-state Michelson interferometers

    International Nuclear Information System (INIS)

    Assaf, Ohad; Ben-Aryeh, Yacob

    2002-01-01

    In the present study we extend and generalize previous results for coherent-state and squeezed-state Michelson interferometer quantum mechanical uncertainties (or fluctuations), which are commonly referred to as 'quantum noise'. The calculation of photon counting (PC) fluctuations in the squeezed-state interferometer is extended to fourth-order correlation functions used as the measured signal. We also generalize a 'unified model' for treating both PC and radiation pressure fluctuations in the coherent-state interferometer, by using mathematical methods which apply to Kerr-type interactions. The results are more general than those reported previously in two ways. First, we obtain exact expressions, which lead to previous results under certain approximations. Second, we deal with cases in which the responses of the two mirrors to radiation pressure are not equal

  11. A differential Michelson interferometer with orthogonal single frequency laser for nanometer displacement measurement

    International Nuclear Information System (INIS)

    Yan, Liping; Chen, Benyong; Wang, Bin

    2017-01-01

    A novel differential Michelson laser interferometer is proposed to eliminate the influence of environmental fluctuations for nanometer displacement measurement. This differential interferometer consists of two homodyne interferometers in which two orthogonal single frequency beams share common reference arm and partial measurement arm. By modulating the displacement of the common reference arm with a piezoelectric transducer, the common-mode displacement drift resulting from the environmental disturbances can be well suppressed and the measured displacement as differential-mode displacement signal is achieved. In addition, a phase difference compensation method is proposed for accurately determining the phase difference between interference signals by correcting the time interval according to the average speed in one cycle of interference signal. The nanometer displacement measurement experiments were performed to demonstrate the effectiveness and feasibility of the proposed interferometer and show that precision displacement measurement with standard deviation less than 1 nm has been achieved. (paper)

  12. Hyperfine spectrum measurement of an optically pumped far-infrared laser with a Michelson interferometer

    International Nuclear Information System (INIS)

    Zuo, Z G; Ling, F R; Wang, P; Liu, J S; Yao, J Q; Weng, C X

    2013-01-01

    In this letter, we present a Michelson interferometer for the hyperfine spectrum measurement of an optically pumped far-infrared laser with a highest frequency resolution of 3–5 GHz. CH 3 OH gas with a purity of 99.9%, is pumped by the CO 2 9P36 and 9R10 laser lines to generate terahertz lasers with frequencies of 2.52 and 3.11 THz, respectively. Moreover, except for the center frequency, which is in good agreement with theoretical work, some additional frequencies on both sides of the center frequency are obtained at a frequency interval of 0.15 THz. Meanwhile, the mechanism behind the observed experimental results is also investigated. (letter)

  13. Optical-feedback semiconductor laser Michelson interferometer for displacement measurements with directional discrimination

    International Nuclear Information System (INIS)

    Rodrigo, Peter John; Lim, May; Saloma, Caesar

    2001-01-01

    An optical-feedback semiconductor laser Michelson interferometer (OSMI) is presented for measuring microscopic linear displacements without ambiguity in the direction of motion. The two waves from the interferometer arms, one from the reference mirror and the other from the reflecting moving target, are fed back into the lasing medium (λ=830 nm), causing variations in the laser output power. We model the OSMI into an equivalent Fabry-Perot resonator and derive the dependence of the output power (and the junction voltage) on the path difference between the two interferometer arms. Numerical and experimental results consistently show that the laser output power varies periodically (period, λ/2) with path difference. The output power variation exhibits an asymmetric behavior with the direction of motion, which is used to measure, at subwavelength resolution, the displacement vector (both amplitude and direction) of the moving sample. Two samples are considered in the experiments: (i) a piezoelectric transducer and (ii) an audio speaker

  14. Investigation of shear distance in Michelson interferometer-based shearography for mechanical characterization

    International Nuclear Information System (INIS)

    Lee, Jung-Ryul; Yoon, Dong-Jin; Kim, Jung-Seok; Vautrin, Alain

    2008-01-01

    Shearography is a growing industrial field in both quantitative mechanical characterization and relatively qualitative non-destructive testing. In shearography, shear distance is the most important parameter to control measurement performances. In this paper, the role of the shear distance is systematically investigated, focusing on the application of full-field mechanical characterization. A modified Michelson interferometer is considered as the shearing device, which is most commonly adopted for mechanical characterization applications because it enables easy and precise shearing and phase shifting. This paper also includes theoretical and experimental investigations of the relationship between shear distance and performance issues such as the immeasurable zone in the target with discontinuity, signal-to-noise ratio, sensitivity and shear distortion. In addition, this study is verified with actual shearographic results and a phase-shifting grid method capable of full-field displacement evaluation in the submicrometer regime

  15. Improved operation of the Michelson interferometer ECE diagnostic on DIII-D

    International Nuclear Information System (INIS)

    Austin, M.E.; Ellis, R.F.; Doane, J.L.; James, R.A.

    1996-05-01

    The measurement of accurate temperature profiles is critical for transport analysis and equilibrium reconstruction in the DIII-D tokamak. Recent refinements in the Michelson interferometer diagnostic have produced more precise electron temperature measurements from electron cyclotron emission and made them available for a wider range of discharge conditions. Replacement of a lens-relay with a low-loss corrugated waveguide transmission system resulted in an increase in throughput of 6 dB and reduction of calibration error to around 5%. The waveguide exhibits a small polarization scrambling fraction of 0.05 at the quarter wavelength frequency and very stable transmission characteristics over time. Further reduction in error has been realized through special signal processing of the calibration and plasma interferograms

  16. Polarization Beam Splitter Based on a Self-Collimation Michelson Interferometer in a Silicon Photonic Crystal

    International Nuclear Information System (INIS)

    Chen Xi-Yao; Lin Gui-Min; Li Jun-Jun; Xu Xiao-Fu; Jiang Jun-Zhen; Qiang Ze-Xuan; Qiu Yi-Shen; Li Hui

    2012-01-01

    A polarization beam splitter based on a self-collimation Michelson interferometer (SMI) in a hole-type silicon photonic crystal is proposed and numerically demonstrated. Utilizing the polarization dependence of the transmission spectra of the SMI and polarization peak matching method, the SMI can work as a polarization beam splitter (PBS) by selecting an appropriate path length difference in the structure. Based on its novel polarization beam splitting mechanics, the polarization extinction ratios (PERs) for TM and TE modes are as high as 18.4 dB and 24.3 dB, respectively. Since its dimensions are only several operating wavelengths, the PBS may have practical applications in photonic integrated circuits. (fundamental areas of phenomenology(including applications))

  17. ECE diagnostic for the TARA tandem mirror machine using a fast-scanning Michelson interferometer

    International Nuclear Information System (INIS)

    Guharay, S.K.; Boyd, D.A.; Ellis, R.F.

    1986-01-01

    This ECE (electron cyclotron emission) diagnostic utilizes a fast-scanning Michelson interferometer to determine two parameters, the temperature and the loss cone angle, of the distribution function of the hot electrons (Tapprox. >100 keV) generated in the axisymmetric plug plasma of the TARA tandem mirror device. The radiation transport system employs a lens relay and a low-pass grating filter in order to transmit the synchrotron radiation over a spectral range of 2.9--18.6 cm -1 . This enables us to study the emitted radiation spectrum up to the 40th harmonic of the electron--cyclotron frequency in the plug plasma (B = 5 kG). Details of the design principles and the development of the diagnostic at TARA will be presented

  18. Heterogeneous all-solid multicore fiber based multipath Michelson interferometer for high temperature sensing.

    Science.gov (United States)

    Duan, Li; Zhang, Peng; Tang, Ming; Wang, Ruoxu; Zhao, Zhiyong; Fu, Songnian; Gan, Lin; Zhu, Benpeng; Tong, Weijun; Liu, Deming; Shum, Perry Ping

    2016-09-05

    A compact high temperature sensor utilizing a multipath Michelson interferometer (MI) structure based on weak coupling multicore fiber (MCF) is proposed and experimentally demonstrated. The device is fabricated by program-controlled tapering the spliced region between single mode fiber (SMF) and a segment of MCF. After that, a spherical reflective structure is formed by arc-fusion splicing the end face of MCF. Theoretical analysis has been implemented for this specific multipath MI structure; beam propagation method based simulation and corresponding experiments were performed to investigate the effect of taper and spherical end face on system's performance. Benefiting from the multipath interferences and heterogeneous structure between the center core and surrounding cores of the all-solid MCF, an enhanced temperature sensitivity of 165 pm/°C up to 900°C and a high-quality interference spectrum with 25 dB fringe visibility were achieved.

  19. Measurements of refractive indices and thermo-optical coefficients using a white-light Michelson interferometer.

    Science.gov (United States)

    Rocha, A C P; Silva, J R; Lima, S M; Nunes, L A O; Andrade, L H C

    2016-08-20

    A dispersive white-light Michelson interferometer was used to determine the wavelength dependence of the refractive index (n) in the visible range from 425 to 775 nm and the thermo-optical coefficient (dn/dT) of fused silica (FS) and borosilicate glass (BK7). For FS, the values obtained for n and dn/dT at 546 nm were 1.46079 and 11.3×10-6  K-1, respectively, while the values for BK7 glass were 1.51825 and 2.2×10-6  K-1, respectively, which is in good agreement with the literature. The accuracy of the methodology used for n was almost 10-6, enabling precise spectroscopic characterization of materials across a wide spectral range.

  20. Effect of input spectrum on the spectral switch characteristics in a white-light Michelson interferometer.

    Science.gov (United States)

    Brundavanam, Maruthi M; Viswanathan, Nirmal K; Rao, D Narayana

    2009-12-01

    We report here a detailed experimental study to demonstrate the effect of source spectral characteristics such as spectral bandwidth (Deltalambda), peak wavelength (lambda(0)), and shape of the spectrum on the spectral shifts and spectral switches measured due to temporal correlation in a white-light Michelson interferometer operated in the spectral domain. Behavior of the spectral switch characteristics such as the switch position, switch amplitude, and switch symmetry are discussed in detail as a function of optical path difference between the interfering beams. The experimental results are compared with numerical calculations carried out using interference law in the spectral domain with modified source spectral characteristics. On the basis of our results we feel that our study is of critical importance in the selection of source spectral characteristics to further improve the longitudinal resolution or the measurement sensitivity in spectral-domain optical coherence tomography and microscopy.

  1. Frequency locking of a field-widened Michelson interferometer based on optimal multi-harmonics heterodyning.

    Science.gov (United States)

    Cheng, Zhongtao; Liu, Dong; Zhou, Yudi; Yang, Yongying; Luo, Jing; Zhang, Yupeng; Shen, Yibing; Liu, Chong; Bai, Jian; Wang, Kaiwei; Su, Lin; Yang, Liming

    2016-09-01

    A general resonant frequency locking scheme for a field-widened Michelson interferometer (FWMI), which is intended as a spectral discriminator in a high-spectral-resolution lidar, is proposed based on optimal multi-harmonics heterodyning. By transferring the energy of a reference laser to multi-harmonics of different orders generated by optimal electro-optic phase modulation, the heterodyne signal of these multi-harmonics through the FWMI can reveal the resonant frequency drift of the interferometer very sensitively within a large frequency range. This approach can overcome the locking difficulty induced by the low finesse of the FWMI, thus contributing to excellent locking accuracy and lock acquisition range without any constraint on the interferometer itself. The theoretical and experimental results are presented to verify the performance of this scheme.

  2. Effect of imperfect Faraday mirrors on the security of a Faraday–Michelson quantum cryptography system

    International Nuclear Information System (INIS)

    Wang, Wei-Long; Gao, Ming; Ma, Zhi

    2013-01-01

    The one-way Faraday–Michelson system is a very useful practical quantum cryptography system where Faraday mirrors (FMs) play an important role. In this paper we analyze the security of this system against imperfect FMs. We consider the security loophole caused by imperfect FMs in Alice’s and Bob’s security zones. Then we implement a passive FM attack in this system. By changing the values of the imperfection parameters of Alice’s FMs, we calculate the quantum bit error rate between Alice and Bob induced by Eve and the probability that Eve obtains outcomes successfully. It is shown that the imperfection of one of Alice’s two FMs makes the system sensitive to an attack. Finally we give a modified key rate as a function of the FM imperfections. The security analysis indicates that both Alice’s and Bob’s imperfect FMs can compromise the secure key. (paper)

  3. Doppler echocardiography in pediatric cardiology

    International Nuclear Information System (INIS)

    Allen, H.D.; Marx, G.R.

    1986-01-01

    Congenital heart disease encompasses abnormalities in cardiac development which generally have in common either valve stenoses or connections between chambers or great vessels. Usually, abnormalities of intracardiac anatomy, and often, abnormalities of great vessel anatomy, can be unraveled by two-dimensional echocardiography. However, echocardiography offers little information regarding flow characteristics in the various congenital lesions. Addition of the Doppler principle, particularly when combined with the two-dimensional examination, can characterize the source of a flow disturbance, quantify gradients across a site of obstruction, and quantify flow volume across sites where flow is nonturbulent. These features make Doppler echocardiography unique for noninvasive accurate evaluation of children and adults with various forms of congenital heart disease. In this report, the authors discuss some of the present uses of Doppler echocardiography in congenital heart disease. Application of this technique requires greater understanding of certain physics principles than does routine echocardiography

  4. Spectroscopic Doppler analysis for visible-light optical coherence tomography

    Science.gov (United States)

    Shu, Xiao; Liu, Wenzhong; Duan, Lian; Zhang, Hao F.

    2017-12-01

    Retinal oxygen metabolic rate can be effectively measured by visible-light optical coherence tomography (vis-OCT), which simultaneously quantifies oxygen saturation and blood flow rate in retinal vessels through spectroscopic analysis and Doppler measurement, respectively. Doppler OCT relates phase variation between sequential A-lines to the axial flow velocity of the scattering medium. The detectable phase shift is between -π and π due to its periodicity, which limits the maximum measurable unambiguous velocity without phase unwrapping. Using shorter wavelengths, vis-OCT is more vulnerable to phase ambiguity since flow induced phase variation is linearly related to the center wavenumber of the probing light. We eliminated the need for phase unwrapping using spectroscopic Doppler analysis. We split the whole vis-OCT spectrum into a series of narrow subbands and reconstructed vis-OCT images to extract corresponding Doppler phase shifts in all the subbands. Then, we quantified flow velocity by analyzing subband-dependent phase shift using linear regression. In the phantom experiment, we showed that spectroscopic Doppler analysis extended the measurable absolute phase shift range without conducting phase unwrapping. We also tested this method to quantify retinal blood flow in rodents in vivo.

  5. Doppler ultrasound for diagnosis of soft tissue sarcoma: efficacy of ultrasound-based screening score

    Directory of Open Access Journals (Sweden)

    Nagano Satoshi

    2015-06-01

    Full Text Available Background. The utility of ultrasound imaging in the screening of soft-part tumours (SPTs has been reported. We classified SPTs according to their blood flow pattern on Doppler ultrasound and re-evaluated the efficacy of this imaging modality as a screening method. Additionally, we combined Doppler ultrasound with several values to improve the diagnostic efficacy and to establish a new diagnostic tool.

  6. Implementation and Comparison of Acoustic Travel-Time Measurement Procedures for the Solar Dynamics Observatory-Helioseismic and Magnetic Imager Time-Distance Helioseismology Pipeline

    Science.gov (United States)

    Couvidat, S.; Zhao, J.; Birch, A. C.; Kosovichev, A. G.; Duvall, Thomas L., Jr.; Parchevsky, K.; Scherrer, P. H.

    2010-01-01

    The Helioseismic and Magnetic Imager (HMI) instrument onboard the Solar Dynamics Observatory (SDO) satellite is designed to produce high-resolution Doppler-velocity maps of oscillations at the solar surface with high temporal cadence. To take advantage of these high-quality oscillation data, a time - distance helioseismology pipeline (Zhao et al., Solar Phys. submitted, 2010) has been implemented at the Joint Science Operations Center (JSOC) at Stanford University. The aim of this pipeline is to generate maps of acoustic travel times from oscillations on the solar surface, and to infer subsurface 3D flow velocities and sound-speed perturbations. The wave travel times are measured from cross-covariances of the observed solar oscillation signals. For implementation into the pipeline we have investigated three different travel-time definitions developed in time - distance helioseismology: a Gabor-wavelet fitting (Kosovichev and Duvall, SCORE'96: Solar Convection and Oscillations and Their Relationship, ASSL, Dordrecht, 241, 1997), a minimization relative to a reference cross-covariance function (Gizon and Birch, Astrophys. J. 571, 966, 2002), and a linearized version of the minimization method (Gizon and Birch, Astrophys. J. 614, 472, 2004). Using Doppler-velocity data from the Michelson Doppler Imager (MDI) instrument onboard SOHO, we tested and compared these definitions for the mean and difference traveltime perturbations measured from reciprocal signals. Although all three procedures return similar travel times in a quiet-Sun region, the method of Gizon and Birch (Astrophys. J. 614, 472, 2004) gives travel times that are significantly different from the others in a magnetic (active) region. Thus, for the pipeline implementation we chose the procedures of Kosovichev and Duvall (SCORE'96: Solar Convection and Oscillations and Their Relationship, ASSL, Dordrecht, 241, 1997) and Gizon and Birch (Astrophys. J. 571, 966, 2002). We investigated the relationships among

  7. Implementation and Comparison of Acoustic Travel-Time Measurement Procedures for the Helioseismic and Magnetic Imager Time-Distance Helioseismology Pipeline

    Science.gov (United States)

    Couvidat, S.; Zhao, J.; Birch, A. C.; Kosovichev, A. G.; Duvall, T. L., Jr.; Parchevsky, K.; Scherrer, P. H.

    2009-01-01

    The Helioseismic and Magnetic Imager (HMI) instrument on board the Solar Dynamics Observatory (SDO) satellite is designed to produce high-resolution Doppler velocity maps of oscillations at the solar surface with high temporal cadence. To take advantage of these high-quality oscillation data, a time-distance helioseismology pipeline has been implemented at the Joint Science Operations Center (JSOC) at Stanford University. The aim of this pipeline is to generate maps of acoustic travel times from oscillations on the solar surface, and to infer subsurface 3D flow velocities and sound-speed perturbations. The wave travel times are measured from cross covariances of the observed solar oscillation signals. For implementation into the pipeline we have investigated three different travel-time definitions developed in time-distance helioseismology: a Gabor wavelet fitting (Kosovichev and Duvall, 1997), a minimization relative to a reference cross-covariance function (Gizon and Birch, 2002), and a linearized version of the minimization method (Gizon and Birch, 2004). Using Doppler velocity data from the Michelson Doppler Imager (MDI) instrument on board SOHO, we tested and compared these definitions for the mean and difference travel-time perturbations measured from reciprocal signals. Although all three procedures return similar travel times in a quiet Sun region, the method of Gizon and Birch (2004) gives travel times that are significantly different from the others in a magnetic (active) region. Thus, for the pipeline implementation we chose the procedures of Kosovichev and Duvall (1997) and Gizon and Birch (2002). We investigated the relationships among these three travel-time definitions, their sensitivities to fitting parameters, and estimated the random errors they produce

  8. A miniaturized laser-Doppler-system in the ear canal

    Science.gov (United States)

    Schmidt, T.; Gerhardt, U.; Kupper, C.; Manske, E.; Witte, H.

    2013-03-01

    Gathering vibrational data from the human middle ear is quite difficult. To this date the well-known acoustic probe is used to estimate audiometric parameters, e.g. otoacoustic emissions, wideband reflectance and the measurement of the stapedius reflex. An acoustic probe contains at least one microphone and one loudspeaker. The acoustic parameter determination of the ear canal is essential for the comparability of test-retest measurement situations. Compared to acoustic tubes, the ear canal wall cannot be described as a sound hard boundary. Sound energy is partly absorbed by the ear canal wall. In addition the ear canal features a complex geometric shape (Stinson and Lawton1). Those conditions are one reason for the inter individual variability in input impedance measurement data of the tympanic membrane. The method of Laser-Doppler-Vibrometry is well described in literature. Using this method, the surface velocity of vibrating bodies can be determined contact-free. Conventional Laser-Doppler-Systems (LDS) for auditory research are mounted on a surgical microscope. Assuming a free line of view to the ear drum, the handling of those laser-systems is complicated. We introduce the concept of a miniaturized vibrometer which is supposed to be applied directly in the ear canal for contact-free measurement of the tympanic membrane surface vibration. The proposed interferometer is based on a Fabry-Perot etalon with a DFB laser diode as light source. The fiber-based Fabry-Perot-interferometer is characterized by a reduced size, compared to e.g. Michelson-, or Mach-Zehnder-Systems. For the determination of the phase difference in the interferometer, a phase generated carrier was used. To fit the sensor head in the ear canal, the required shape of the probe was generated by means of the geometrical data of 70 ear molds. The suggested prototype is built up by a singlemode optical fiber with a GRIN-lens, acting as a fiber collimator. The probe has a diameter of 1.8 mm and a

  9. Doppler broadening of cross sections

    International Nuclear Information System (INIS)

    Buckler, P.A.C.; Pull, I.C.

    1962-12-01

    Expressions for temperature dependent cross-sections in terms of resonance parameters are obtained, involving generalisations of the conventional Doppler functions, ψ and φ. Descriptions of Fortran sub-routines, which calculate broadened cross-sections in accordance with the derived formulae, are included. (author)

  10. Dense plasmas interferometry using an X-UV laser. Development of an X-UV Michelson interferometer at 13.9 nm

    International Nuclear Information System (INIS)

    Hubert, S.

    2001-01-01

    After having recalled some aspects related to the physics of plasmas produced by interaction between laser and matter, and related to inertial confinement fusion or ICF (discussion of laser energy absorption, X conversion, parametric and hydrodynamic instabilities, and so on), this research thesis presents various techniques used for plasma diagnosis in order to justify the use of interferometry for the investigation of the electronic density distribution of these plasmas. The physical principle of this diagnosis technique is described and two types of X-UV interferometer are presented, one of them being chosen as more suitable for the study of ICF-type plasmas. The author then describes and reports the experimental investigation performed with a two-mirror Fresnel interferometer and a 21.2 nm zinc X-UV laser: description of the interferometer operation and characteristics, of the specifically designed image system, discussion of plasma interferogram simulations. Then, he reports the development of a Michelson-type X-UV interferometer at 13.9 nm. The operation principle is recalled, and the preliminary modelling phase is reported. The imaging system is presented and results of the interferogram modelling phase are presented [fr

  11. Enormous periodic doppler shifts in SS 433

    International Nuclear Information System (INIS)

    Margon, B.; Ford, H.C.; Grandi, S.A.; Stone, R.P.S.

    1979-01-01

    We have previously reported prominent ''moving' emission lines in the visible spectrum of Stephenson-Sanduleak 433, the optical counterpart of a variable radio and X-ray source. Further observations show that despite the implausible velocities and changes in velocities implied if the moving features are interpreted as Doppler-shifted Balmer lines, this explanation is indeed correct. Spectroscopy of SS 433 on 51 mights in 1978--1979 reveals that the unidentified features are two sets of Balmer and He I lines, one with large and changing redshift, and the other with large and changing blueshift. Combining our data with published earlier observations, we obtain Doppler shifts on 80 nights in the period 1978 June to 1979 June. These data indicate that the velocity variations are cyclical, repeating in both the blueshift and redshift systems with a period of 164 +- 3 days. The two systems have thus far been observed to reach maximum positive and negative radial velocities of +50,000 and -35,000 km s -1 , respectively, are always symmetric about redshift z=0.04, and follow roughly sinusoidal velocity curves. We discuss in addition a variety of interesting short-term spectroscopic details, including minor but highly significant deviations of the radial velocity from the sinusoid, and nightly line profile changes, sometimes appearing as mirror-image events in the redshift and blueshift systems. The behavior of SS 433 is unprecedented

  12. Anomalous Doppler effects in bulk phononic crystal

    International Nuclear Information System (INIS)

    Cai Feiyan; He Zhaojian; Zhang Anqi; Ding Yiqun; Liu Zhengyou

    2010-01-01

    Doppler effects in simple cubic phononic crystal are studied theoretically and numerically. In addition to observing Doppler shifts from a moving source's frequencies inside the gap, we find that Doppler shifts can be multi-order, anisotropic, and the dominant order of shift depends on the band index that the source's frequency is in.

  13. Compact magnetic-field sensor based on optical microfiber Michelson interferometer and Fe3O4 nanofluid.

    Science.gov (United States)

    Deng, Ming; Sun, Xiaokang; Han, Meng; Li, Decai

    2013-02-01

    We report a magnetic-field sensor by merging the advantages of optical fiber Michelson interferometers with that of magnetic fluid. Compact and low-cost optical fiber Michelson interferometers were first fabricated by a high-frequency CO(2) laser, and then they were inserted into glass capillaries with water-based Fe(3)O(4) magnetic fluid as sensing elements. The sensing characteristics have been investigated and the experimental results show that the reflective spectrum of the fiber-magnetic sensor linearly shifted with the change of the magnetic-field strength that is perpendicular to the axial of the devices. The fiber-magnetic sensor with interference arm's diameter of 50 μm is most sensitive to the external magnetic field, and the sensitivity is up to 64.9 pm/mT, which is 20 times higher than that of 125 μm diameter.

  14. Resolving fringe ambiguities of a wide-field Michelson interferometer using visibility measurements of a noncollimated laser beam.

    Science.gov (United States)

    Wan, Xiaoke; Wang, Ji; Ge, Jian

    2009-09-10

    An actively stabilized interferometer with a constant optical path difference is a key element in long-term astronomical observation, and resolving interference fringe ambiguities is important to produce high-precision results for the long term. We report a simple and reliable method of resolving fringe ambiguities of a wide-field Michelson interferometer by measuring the interference visibility of a noncollimated single-frequency laser beam. Theoretical analysis shows that the interference visibility is sensitive to a subfringe phase shift, and a wide range of beam arrangements is suitable for real implementation. In an experimental demonstration, a Michelson interferometer has an optical path difference of 7 mm and a converging monitoring beam has a numerical aperture of 0.045 with an incidental angle of 17 degrees. The resolution of visibility measurements corresponds to approximately 1/16 fringe in the interferometer phase shift. The fringe ambiguity-free region is extended over a range of approximately 100 fringes.

  15. A comparison of delayed self-heterodyne interference measurement of laser linewidth using Mach-Zehnder and Michelson interferometers.

    Science.gov (United States)

    Canagasabey, Albert; Michie, Andrew; Canning, John; Holdsworth, John; Fleming, Simon; Wang, Hsiao-Chuan; Aslund, Mattias L

    2011-01-01

    Linewidth measurements of a distributed feedback (DFB) fibre laser are made using delayed self heterodyne interferometry (DHSI) with both Mach-Zehnder and Michelson interferometer configurations. Voigt fitting is used to extract and compare the Lorentzian and Gaussian linewidths and associated sources of noise. The respective measurements are w(L) (MZI) = (1.6 ± 0.2) kHz and w(L) (MI) = (1.4 ± 0.1) kHz. The Michelson with Faraday rotator mirrors gives a slightly narrower linewidth with significantly reduced error. This is explained by the unscrambling of polarisation drift using the Faraday rotator mirrors, confirmed by comparing with non-rotating standard gold coated fibre end mirrors.

  16. A Comparison of Delayed Self-Heterodyne Interference Measurement of Laser Linewidth Using Mach-Zehnder and Michelson Interferometers

    Directory of Open Access Journals (Sweden)

    Simon Fleming

    2011-09-01

    Full Text Available Linewidth measurements of a distributed feedback (DFB fibre laser are made using delayed self heterodyne interferometry (DHSI with both Mach-Zehnder and Michelson interferometer configurations. Voigt fitting is used to extract and compare the Lorentzian and Gaussian linewidths and associated sources of noise. The respective measurements are wL (MZI = (1.6 ± 0.2 kHz and wL (MI = (1.4 ± 0.1 kHz. The Michelson with Faraday rotator mirrors gives a slightly narrower linewidth with significantly reduced error. This is explained by the unscrambling of polarisation drift using the Faraday rotator mirrors, confirmed by comparing with non-rotating standard gold coated fibre end mirrors.

  17. The Doppler paradox.

    Science.gov (United States)

    Ntalas, Ioannis; Karády, Júlia; Kapetanakis, Stam; Rajani, Ronak

    2017-12-01

    Obstructive prosthetic valve thrombosis (PVT) is a rare but severe complication that usually occurs in the presence of suboptimal anticoagulation. Although fluoroscopy is commonly used to detect abnormal leaflet motion as a surrogate marker for PVT, its inability to directly visualize adjacent tissue and valve physiology leaves it susceptible to miss clinically important PVT. In this manuscript, we report the case of a 54-year-old woman with a mechanical mitral valve who was admitted to our institute with exertional dyspnea. Although valve fluoroscopy was normal, subsequent 3D echocardiography and ECG-gated multiphase computed tomography confirmed the presence of PVT that was subsequently treated successfully with surgical replacement. Our case demonstrates the utility of multimodality imaging in establishing PVT in patients with abnormal prosthetic valve physiology and progressive symptoms. © 2017, Wiley Periodicals, Inc.

  18. Spatial weighting of Doppler reactivity feedback

    International Nuclear Information System (INIS)

    Carew, J.F.; Diamond, D.J.; Todosow, M.

    1977-12-01

    The spatial weighting of the local Doppler feedback implicit in the determination of the core Doppler feedback reactivity has been investigated. Using a detailed planar PDQ7-II PWR model with local fuel-temperature feedback, the core Doppler spatial weight factor, S, has been determined for various control patterns and power levels. Assuming power-squared weighting of the local Doppler feedback, a simple analytic expression for S has been derived and, based on comparison with the PDQ7-II results, provides a convenient and accurate representation of the Doppler spatial weight factor. The sensitivity of these results to variations in the fuel rod heat transfer coefficients, fuel loading and the magnitude of the Doppler coefficient has also been evaluated. The dependence of the local Doppler coefficient on moderator temperature, boron concentration and control rod density has been determined and found to be weak. Selected comparisons with vendor analyses have been made and indicate general agreement

  19. Diagnostic performance of power doppler and ultrasound contrast agents in early imaging-based diagnosis of organ-confined prostate cancer: Is it possible to spare cores with contrast-guided biopsy?

    Energy Technology Data Exchange (ETDEWEB)

    Delgado Oliva, F., E-mail: frandelgol@hotmail.com; Arlandis Guzman, S.; Bonillo García, M.; Broseta Rico, E.; Boronat Tormo, F.

    2016-10-15

    Objectives: To evaluate the diagnostic performance of gray scale transrectal ultrasound-B-mode US (BMUS), power Doppler (PDUS), and sonographic contrast (CEUS) in early imaging-based diagnosis of localized prostate cancer (PCa) and to compare the diagnostic profitability of randomized biopsy (RB), US-targeted prostate biopsy by means of PDUS and CEUS. Material and methods: A single-center, prospective, transversal, epidemiological study was conducted from January 2010 to January 2014. We consecutively included patients who an imaging study of the prostate with BMUS, PDUS, and CEUS was performed, followed by prostate biopsy due to clinical suspicion of prostate cancer (PSA 4–20 ng/mL and/or rectal exam suggestive of malignancy). The diagnostic performance of BMUS, PDUS, and CEUS was determined by calculating the Sensitivity (S), Specificity (Sp), Predictive values (PV), and diagnostic odds ratio (OR) of the diagnosis tests and, for these variables, in the population general and based on their clinical stage according to rectal exam (cT1 and cT2). PCa detection rates determined by means of a randomized 10-core biopsy scheme were compared with detection rates of CEUS-targeted (SonoVue) 2-core biopsies. Results: Of the initial 984 patients, US contrast SonoVue was administered to 179 (18.2%). The PCa detection rate by organ of BMUS/PDUS in the global population was 38% versus 43% in the subpopulation with CEUS. The mean age of the patients was 64.3 ± 7.01 years (95% CI, 63.75–64.70); mean total PSA was 8.9 ± 3.61 ng/mL (95% CI, 8.67–9.13) and the mean prostate volume was 56.2 ± 29 cc (95% CI, 54.2–58.1). The detection rate by organ of targeted biopsy with BMUS, PDUS, and CEUS were as follows: Global population (10.6, 8.2, 24.5%), stage cT1 (5.6, 4.2, 16.4%), and stage cT2 (32.4, 22.3, 43.5%). Comparing the detection rates of the CEUS-targeted biopsy and randomized biopsy, the following results were obtained: Global population (24.5% vs. 41.8%), stage cT1 (16

  20. Diagnostic performance of power doppler and ultrasound contrast agents in early imaging-based diagnosis of organ-confined prostate cancer: Is it possible to spare cores with contrast-guided biopsy?

    Science.gov (United States)

    Delgado Oliva, F; Arlandis Guzman, S; Bonillo García, M; Broseta Rico, E; Boronat Tormo, F

    2016-10-01

    To evaluate the diagnostic performance of gray scale transrectal ultrasound-B-mode US (BMUS), power Doppler (PDUS), and sonographic contrast (CEUS) in early imaging-based diagnosis of localized prostate cancer (PCa) and to compare the diagnostic profitability of randomized biopsy (RB), US-targeted prostate biopsy by means of PDUS and CEUS. A single-center, prospective, transversal, epidemiological study was conducted from January 2010 to January 2014. We consecutively included patients who an imaging study of the prostate with BMUS, PDUS, and CEUS was performed, followed by prostate biopsy due to clinical suspicion of prostate cancer (PSA 4-20ng/mL and/or rectal exam suggestive of malignancy). The diagnostic performance of BMUS, PDUS, and CEUS was determined by calculating the Sensitivity (S), Specificity (Sp), Predictive values (PV), and diagnostic odds ratio (OR) of the diagnosis tests and, for these variables, in the population general and based on their clinical stage according to rectal exam (cT1 and cT2). PCa detection rates determined by means of a randomized 10-core biopsy scheme were compared with detection rates of CEUS-targeted (SonoVue) 2-core biopsies. Of the initial 984 patients, US contrast SonoVue was administered to 179 (18.2%). The PCa detection rate by organ of BMUS/PDUS in the global population was 38% versus 43% in the subpopulation with CEUS. The mean age of the patients was 64.3±7.01years (95% CI, 63.75-64.70); mean total PSA was 8.9±3.61ng/mL (95% CI, 8.67-9.13) and the mean prostate volume was 56.2±29cc (95% CI, 54.2-58.1). The detection rate by organ of targeted biopsy with BMUS, PDUS, and CEUS were as follows: Global population (10.6, 8.2, 24.5%), stage cT1 (5.6, 4.2, 16.4%), and stage cT2 (32.4, 22.3, 43.5%). Comparing the detection rates of the CEUS-targeted biopsy and randomized biopsy, the following results were obtained: Global population (24.5% vs. 41.8%), stage cT1 (16% vs. 35%), and stage cT2 (43.5% vs. 66.6%), with a p value0

  1. Diagnostic performance of power doppler and ultrasound contrast agents in early imaging-based diagnosis of organ-confined prostate cancer: Is it possible to spare cores with contrast-guided biopsy?

    International Nuclear Information System (INIS)

    Delgado Oliva, F.; Arlandis Guzman, S.; Bonillo García, M.; Broseta Rico, E.; Boronat Tormo, F.

    2016-01-01

    Objectives: To evaluate the diagnostic performance of gray scale transrectal ultrasound-B-mode US (BMUS), power Doppler (PDUS), and sonographic contrast (CEUS) in early imaging-based diagnosis of localized prostate cancer (PCa) and to compare the diagnostic profitability of randomized biopsy (RB), US-targeted prostate biopsy by means of PDUS and CEUS. Material and methods: A single-center, prospective, transversal, epidemiological study was conducted from January 2010 to January 2014. We consecutively included patients who an imaging study of the prostate with BMUS, PDUS, and CEUS was performed, followed by prostate biopsy due to clinical suspicion of prostate cancer (PSA 4–20 ng/mL and/or rectal exam suggestive of malignancy). The diagnostic performance of BMUS, PDUS, and CEUS was determined by calculating the Sensitivity (S), Specificity (Sp), Predictive values (PV), and diagnostic odds ratio (OR) of the diagnosis tests and, for these variables, in the population general and based on their clinical stage according to rectal exam (cT1 and cT2). PCa detection rates determined by means of a randomized 10-core biopsy scheme were compared with detection rates of CEUS-targeted (SonoVue) 2-core biopsies. Results: Of the initial 984 patients, US contrast SonoVue was administered to 179 (18.2%). The PCa detection rate by organ of BMUS/PDUS in the global population was 38% versus 43% in the subpopulation with CEUS. The mean age of the patients was 64.3 ± 7.01 years (95% CI, 63.75–64.70); mean total PSA was 8.9 ± 3.61 ng/mL (95% CI, 8.67–9.13) and the mean prostate volume was 56.2 ± 29 cc (95% CI, 54.2–58.1). The detection rate by organ of targeted biopsy with BMUS, PDUS, and CEUS were as follows: Global population (10.6, 8.2, 24.5%), stage cT1 (5.6, 4.2, 16.4%), and stage cT2 (32.4, 22.3, 43.5%). Comparing the detection rates of the CEUS-targeted biopsy and randomized biopsy, the following results were obtained: Global population (24.5% vs. 41.8%), stage cT1 (16

  2. Chirality-induced polarization effects in the cuticle of scarab beetles: 100 years after Michelson

    Science.gov (United States)

    Arwin, Hans; Magnusson, Roger; Landin, Jan; Järrendahl, Kenneth

    2012-04-01

    One hundred years ago Michelson discovered circular polarization in reflection from beetles. Today a novel Mueller-matrix ellipsometry setup allows unprecedented detailed characterization of the beetles' polarization properties. A formalism based on elliptical polarization for description of reflection from scarab beetles is here proposed and examples are given on four beetles of different character: Coptomia laevis - a simple dielectric mirror; Cetonia aurata - a left-hand narrow-band elliptical polarizer; Anoplognathus aureus - a broad-band elliptical polarizer; and Chrysina argenteola - a left-hand polarizer for visible light at small angles, whereas for larger angles, red reflected light is right-handed polarized. We confirm the conclusion of previous studies which showed that a detailed quantification of ellipticity and degree of polarization of cuticle reflection can be performed instead of only determining whether reflections are circularly polarized or not. We additionally investigate reflection as a function of incidence angle. This provides much richer information for understanding the behaviour of beetles and for structural analysis.

  3. A Michelson interferometer/polarimeter on the Tokamak Fusion Test Reactor (TFTR)

    International Nuclear Information System (INIS)

    Park, H.K.; Mansfield, D.K.; Johnson, L.C.; Ma, C.H.

    1987-01-01

    A multichannel interferometer/polarimeter for the Tokamak Fusion Test Reactor (TFTR) has been developed in order to study the time dependent plasma current density (J/sub p/) and electron density (n/sub e/) profile simultaneously. The goal of the TFTR is demonstration of breakeven via dueuterium and tritium (DT) plasma. In order to be operated and maintained during DT operation phase, the system is designed based on the Michelson geometry which possesses intrinsic standing wave problems. So far, there has been no observable signals due to these standing waves. However, a standing wave resulted from the beam path design to achieve a optimum use of the laser power was found. This standing wave has not prevented initial 10 channel interferometer operation. However, a single channel polarimeter test indicated this standing wave was fatal for Faraday notation measurements. Techniques employing 1/2 wave plates and polarizers have been applied to eliminate this standing wave problem. The completion of 10 channel Faraday rotation measurements may be feasible in the near future

  4. An improved Michelson interferometer: smoothing out the rough spots for a more effective teaching tool

    Science.gov (United States)

    Eastman, Clarke K.

    2017-08-01

    The Michelson interferometer is a classic tool for demonstrating the wave nature of light, and it is a cornerstone of the optics curriculum. But many students' experiences with this device are higher in frustration than they are in learning. That situation motivated an effort to make aligning the tool less a test of a visual acuity and patience, and more of an introduction to optics phenomena and optical engineering. Key improvements included an added beam-splitter to accommodate multiple observers, a modified telescope to quickly and reliably obtain parallel mirrors, and a series of increasing spectral-width light sources to obtain equal path lengths. This greatly improved students' chances of success, as defined by achieving "white light fringes". When presenting these new features to the students, high importance is placed on understanding why alignment was so difficult with the original design, and why the changes made alignment easier. By exposing the rationale behind the improvements, students can observe the process of problem-solving in an optical engineering scenario. Equally important is the demonstration that solutions can be devised or adapted based on the parts at hand, and that implementations only achieve a highly "polished' state after several design iterations.

  5. DESIGN AND CHARACTERIZATION OF THERMALLY ACTUATED BIMETALLIC MEMBRANES BY MICHELSON INTERFEROMETRY

    Directory of Open Access Journals (Sweden)

    JULIO ENRIQUE DUARTE

    2011-01-01

    Full Text Available En el presente trabajo se describen el diseño y la caracterización de membranas bimetálicas de Al-Si, con actuación térmica. El diseño se realizó empleando el método de los Elementos Finitos y se concentró en optimizar la relación de los espesores de las capas de aluminio y silicio. La defl exión de las membranas se determinó aplicando la técnica del Interferómetro de Michelson. En la etapa experimental se utilizaron membranas cuadradas de 5 mm de lado, con un espesor de 10 mm para el silicio y espesores de 4 y 1 mm para el aluminio. La caracterización entregó un desplazamiento máximo de 14 mm para la membrana con 4 mm de Al, lo cual es consistente con los resultados obtenidos numéricamente.

  6. Interference of Light in a Michelson-Morley Interferometer: A Quantum Optical Approach

    Directory of Open Access Journals (Sweden)

    Ø. Langangen

    2012-01-01

    Full Text Available The temporal coherence interference properties of light as revealed by single detector intensity measurements in a Michelson-Morley interferometer (MMI is often described in terms of classical optics. We show, in a pedagogical manner, how such features of light also can be understood in terms of a more general quantum-optics framework. If a thermal reference source is used in the MMI local oscillator port in combination with a thermal source in the signal port, the interference pattern revealed by single detector intensity measurements shows a distinctive dependence on the differences in the temperature of the two sources. A related method has actually been used to perform high-precision measurements of the cosmic microwave background radiation. The general quantum-optics framework allows us to consider any initial quantum state. As an example, we consider the interference of single photons as a tool to determine the peak angular-frequency of a single-photon pulse interfering with a single-photon reference pulse. A similar consideration for laser pulses, in terms of coherent states, leads to a different response in the detector. The MMI experimental setup is therefore an example of an optical device where one, in terms of intensity measurements, can exhibit the difference between classical and quantum-mechanical light.

  7. Study of Fourier transform spectrometer based on Michelson interferometer wave-meter

    Science.gov (United States)

    Peng, Yuexiang; Wang, Liqiang; Lin, Li

    2008-03-01

    A wave-meter based on Michelson interferometer consists of a reference and a measurement channel. The voice-coiled motor using PID means can realize to move in stable motion. The wavelength of a measurement laser can be obtained by counting interference fringes of reference and measurement laser. Reference laser with frequency stabilization creates a cosine interferogram signal whose frequency is proportional to velocity of the moving motor. The interferogram of the reference laser is converted to pulse signal, and it is subdivided into 16 times. In order to get optical spectrum, the analog signal of measurement channel should be collected. The Analog-to-Digital Converter (ADC) for measurement channel is triggered by the 16-times pulse signal of reference laser. So the sampling rate is constant only depending on frequency of reference laser and irrelative to the motor velocity. This means the sampling rate of measurement channel signals is on a uniform time-scale. The optical spectrum of measurement channel can be processed with Fast Fourier Transform (FFT) method by DSP and displayed on LCD.

  8. Length sensing and control of a Michelson interferometer with power recycling and twin signal recycling cavities.

    Science.gov (United States)

    Gräf, Christian; Thüring, André; Vahlbruch, Henning; Danzmann, Karsten; Schnabel, Roman

    2013-03-11

    The techniques of power recycling and signal recycling have proven as key concepts to increase the sensitivity of large-scale gravitational wave detectors by independent resonant enhancement of light power and signal sidebands within the interferometer. Developing the latter concept further, twin signal recycling was proposed as an alternative to conventional detuned signal recycling. Twin signal recycling features the narrow-band sensitivity gain of conventional detuned signal recycling but furthermore facilitates the injection of squeezed states of light, increases the detector sensitivity over a wide frequency band and requires a less complex detection scheme for optimal signal readout. These benefits come at the expense of an additional recycling mirror, thus increasing the number of degrees of freedom in the interferometer which need to be controlled.In this article we describe the development of a length sensing and control scheme and its successful application to a tabletop-scale power recycled Michelson interferometer with twin signal recycling. We were able to lock the interferometer in all relevant longitudinal degrees of freedom and thus laid the foundation for further investigations of this interferometer configuration to evaluate its viability for the application in gravitational wave detectors.

  9. Elimination of drift in a fiber-Bragg-grating-based multiplexed Michelson interferometer measurement system.

    Science.gov (United States)

    Ren, Junyu; Xie, Fang; Chen, Zhimin

    2010-02-01

    Random phase drift in single-mode optical fiber interferometers used with measurement systems, which is resulted from various types of environmental disturbances, should be eliminated in order to obtain high measurement precision. We propose an optical fiber interferometric measurement system which has the function of self-eliminating the random phase drift and is stable and robust enough for real-time precision measurement. By employing the characteristics of fiber Bragg gratings, the system interleaves two fiber Michelson interferometers together that share the common-interferometric-optical path. The signal of one of the interferometers is used to stabilize the system while the signal of the other interferometer is used for measurement. An electronic feedback loop for the stabilizing action is designed. The bandwidth of the feedback loop is 5 kHz, sufficiently wide to eliminate random phase drift resulted from various environmental disturbances. The system is endowed with high stability and therefore suitable for real-time precision measurement. By means of an active phase tracking technique to measure displacement, the linear regression coefficient of the displacement measurement results is 0.9998.

  10. Absolute distance measurement with micrometer accuracy using a Michelson interferometer and the iterative synthetic wavelength principle.

    Science.gov (United States)

    Alzahrani, Khaled; Burton, David; Lilley, Francis; Gdeisat, Munther; Bezombes, Frederic; Qudeisat, Mohammad

    2012-02-27

    We present a novel system that can measure absolute distances of up to 300 mm with an uncertainty of the order of one micrometer, within a timeframe of 40 seconds. The proposed system uses a Michelson interferometer, a tunable laser, a wavelength meter and a computer for analysis. The principle of synthetic wave creation is used in a novel way in that the system employs an initial low precision estimate of the distance, obtained using a triangulation, or time-of-flight, laser system, or similar, and then iterates through a sequence of progressively smaller synthetic wavelengths until it reaches micrometer uncertainties in the determination of the distance. A further novel feature of the system is its use of Fourier transform phase analysis techniques to achieve sub-wavelength accuracy. This method has the major advantages of being relatively simple to realize, offering demonstrated high relative precisions better than 5 × 10(-5). Finally, the fact that this device does not require a continuous line-of-sight to the target as is the case with other configurations offers significant advantages.

  11. Field-widened Michelson interferometer for spectral discrimination in high-spectral-resolution lidar: practical development.

    Science.gov (United States)

    Cheng, Zhongtao; Liu, Dong; Zhang, Yupeng; Yang, Yongying; Zhou, Yudi; Luo, Jing; Bai, Jian; Shen, Yibing; Wang, Kaiwei; Liu, Chong; Su, Lin; Yang, Liming

    2016-04-04

    A field-widened Michelson interferometer (FWMI), which is intended as the spectroscopic discriminator in ground-based high-spectral-resolution lidar (HSRL) for atmospheric aerosol detection, is described in this paper. The structure, specifications and design of the developed prototype FWMI are introduced, and an experimental approach is proposed to optimize the FWMI assembly and evaluate its comprehensive characteristic simultaneously. Experimental results show that, after optimization process, the peak-to-valley (PV) value and root-mean-square (RMS) value of measured OPD variation for the FWMI are 0.04λ and 0.008λ respectively among the half divergent angle range of 1.5 degree. Through an active locking technique, the frequency of the FWMI can be locked to the laser transmitter with accuracy of 27 MHz for more than one hour. The practical spectral discrimination ratio (SDR) for the developed FWMI is evaluated to be larger than 86 if the divergent angle of incident beam is smaller than 0.5 degree. All these results demonstrate the great potential of the developed FWMI as the spectroscopic discriminator for HSRLs, as well as the feasibility of the proposed design and optimization process. This paper is expected to provide a good entrance for the lidar community in future HSRL developments using the FWMI technique.

  12. Measurements of femtosecond pulse temporal profile by means of a Michelson interferometer with a Schottky junction.

    Science.gov (United States)

    Ling, Yan; Lu, Fang

    2006-12-20

    We introduce a new method for femtosecond pulse shape measurement. The interference of two pulses is employed rather than the second-harmonic generation (SHG). Usually, the measurements of the femtosecond pulse is realized by an interferometer in combination with a nonlinear optical material, while the measurement that we describe is realized by means of a Michelson interferometer with a Schottky junction. Only a metal-semiconductor junction (Schottky junction) is needed, and neither the nonlinear optical material nor a photodetector is included. The two-photon absorption arises when the light is strong enough, while there is only a one-photon absorption when the light is weak. And the calculations are in good agreement with the experimental results. In principle, the new technique could be used for the measuring of pulses with any duration and with very low power. Unlike the SHG scheme, in the new method the quality of optics, mechanics, and other elements of the scheme are not essential, and the measurement is easily realized, but the results are quite precise and very sensitive to the light.

  13. Polarization-dependent in-line quasi-Michelson interferometer based on PM-PCF reflection.

    Science.gov (United States)

    Du, Yanying; Qiao, Xueguang; Rong, Qiangzhou; Zhang, Jing; Feng, Dingyi; Wang, Ruohui; Sun, Hao; Hu, Manli; Feng, Zhongyao

    2013-05-20

    An in-line fiber quasi-Michelson interferometer (IFQMI) working on reflection is proposed and experimentally demonstrated. The sensing head is fabricated by splicing a section of polarization-maintaining photonic crystal fiber (PM-PCF) with a lead-in single mode fiber (SMF). Some cladding modes are excited into the PM-PCF via the mismatch-core splicing interface between PM-PCF and SMF. Besides, two orthogonal polarized-modes are formed due to the inherent multiholes cladding structure of the PM-PCF. A well-defined interference pattern is obtained as the result of cladding-orthogonal modes interference. The IFQMI with 20 cm long PM-PCF is proposed for strain and torsion measurements. A strain sensitivity of -1.3 pm/με and a torsion sensitivity of -19.17 pm/deg are obtained, respectively. The proposed device with 10 cm long PM-PCF exhibits a considered temperature sensitivity of 9.9 pm/°C. The IFQMI has a compact structure and small size, making it a good candidate for multiparameter measurements.

  14. Probing of microscale phase-change phenomena based on Michelson interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Sik [Pohang Univ. of Science and Techonology, Pohang (Korea, Republic of); Park, Hee K. [IBM, San Jose (United States); Grigoropoulos, Costas P. [Univ. of California at Berkeley, Berkeley (United States)

    2001-07-01

    Experimental schemes that enable characterization of phase-change phenomena in the microscale regime is essential for understanding the phase-change kinetics. Particularly, monitoring rapid vaporization on a submicron length scale is an important yet challenging task in a variety of laser-processing applications, including steam laser cleaning and liquid-assisted material ablation. This paper introduces a novel technique based on Michelson interferometry for probing the liquid-vaporization process on a solid surface heated by a KrF excimer laser pulse({lambda}=248nm, FWHM=24 ns) in water. The effective thickness of a microbubble layer has been measured with nanosecond time resolution. The maximum bubble size and growth rate are estimated to be of the order of 0.1 {mu}m and 1 m/s, respectively. The results show that the acoustic enhancement in the laser induced vaporization process is caused by bubble expansion in the initial growth stage, not by bubble collapse. This work demonstrates that the interference method is effective for detecting bubble nucleation and microscale vaporization kinetics.

  15. Color Doppler Ultrasonographic Findings of Vascular Leiomyoma: Pathologic Correlation

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Ji Young; Koh, Sung Hye; Min, Soo Kee; Choi, A Lam; Jang, Kyung Mi; Lee, Yul; Lee, Kwan Seop; Lee, Hyun; Sohn, Jeong Hee [Hallym University Sacred Heart Hospital, Anyang (Korea, Republic of); Kim, Sam Soo [Kangwon National University College of Medicine, Chuncheon (Korea, Republic of)

    2009-12-15

    To evaluate the distribution of color flow signals on color Doppler ultrasonography of vascular leiomyomas and to correlate them with pathologic findings. We retrospectively analyzed color Doppler ultrasonographic images and pathologic slides of six vascular leiomyomas. We classified the patterns of distribution of color flow signals into localized compact cluster types and non-cluster types, and the pathologic findings into three subtypes: solid, venous and cavernous. All cases showed well-defined homogenous hypoechoic subcutaneous masses on gray-scale ultrasonography. Three cases showed localized compact cluster types on color Doppler ultrasonography, one in each subtype (solid, venous and cavernous). For the three non-cluster types, again there was on in each subtype. In addition, on pathologic analysis the zone of the localized compact cluster of color flow signals coincided with a cluster of larger, vascular caliber masses. Localized compact clusters of color flow signals on color Doppler ultrasonography were seen in 50% of our cases and correlated with a cluster of larger vascular caliber in the mass. But the pattern of distribution of color flows didn't show a correlation with pathologic type

  16. Color Doppler Ultrasonographic Findings of Vascular Leiomyoma: Pathologic Correlation

    International Nuclear Information System (INIS)

    Ko, Ji Young; Koh, Sung Hye; Min, Soo Kee; Choi, A Lam; Jang, Kyung Mi; Lee, Yul; Lee, Kwan Seop; Lee, Hyun; Sohn, Jeong Hee; Kim, Sam Soo

    2009-01-01

    To evaluate the distribution of color flow signals on color Doppler ultrasonography of vascular leiomyomas and to correlate them with pathologic findings. We retrospectively analyzed color Doppler ultrasonographic images and pathologic slides of six vascular leiomyomas. We classified the patterns of distribution of color flow signals into localized compact cluster types and non-cluster types, and the pathologic findings into three subtypes: solid, venous and cavernous. All cases showed well-defined homogenous hypoechoic subcutaneous masses on gray-scale ultrasonography. Three cases showed localized compact cluster types on color Doppler ultrasonography, one in each subtype (solid, venous and cavernous). For the three non-cluster types, again there was on in each subtype. In addition, on pathologic analysis the zone of the localized compact cluster of color flow signals coincided with a cluster of larger, vascular caliber masses. Localized compact clusters of color flow signals on color Doppler ultrasonography were seen in 50% of our cases and correlated with a cluster of larger vascular caliber in the mass. But the pattern of distribution of color flows didn't show a correlation with pathologic type

  17. Development of Rayleigh Doppler lidar for measuring middle atmosphere winds

    Science.gov (United States)

    Raghunath, K.; Patra, A. K.; Narayana Rao, D.

    Interpretation of most of the middle and upper atmospheric dynamical and chemical data relies on the climatological description of the wind field Rayleigh Doppler lidar is one instrument which monitors wind profiles continuously though continuity is limited to clear meteorological conditions in the middle atmosphere A Doppler wind lidar operating in incoherent mode gives excellent wind and temperature information at these altitudes with necessary spectral sensitivity It observes atmospheric winds by measuring the spectral shift of the scattered light due to the motions of atmospheric molecules with background winds and temperature by spectral broadening The presentation is about the design and development of Incoherent Doppler lidar to obtain wind information in the height regions of 30-65 km The paper analyses and describes various types of techniques that can be adopted viz Edge technique and Fringe Imaging technique The paper brings out the scientific objectives configuration simulations error sources and technical challenges involved in the development of Rayleigh Doppler lidar The presentation also gives a novel technique for calibrating the lidar

  18. Transthoracic Doppler echocardiography to predict optimal tube pulsing window for coronary artery CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Gang, E-mail: cjr.sungang@vip.163.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Li, Min, E-mail: limin22000@yahoo.com.cn [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Jiang, Xiang-sen, E-mail: jiangxiangsen123@126.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Li, Li, E-mail: leely1976@yahoo.com.cn [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Peng, Zhao-hui, E-mail: zhaohuipeng_R@163.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China); Mu, Nan-nan, E-mail: munannan22000@sohu.com [Department of Medical Imaging, Jinan Military General Hospital, No. 25, Shifan Road, Jinan, Shandong Province 250031 (China)

    2012-09-15

    Rationale and objective: To evaluate the feasibility of transthoracic Doppler echocardiography to determine the optimal pulsing windows for CT coronary angiography to narrow the pulsing windows further, especially in higher heart rate. Materials and methods: Doppler was performed on 135 patients before CT scanning. For Doppler, the intervals with minimal motion were evaluated during both systole and diastole integrating electrocardiogram (ECG) intervals. For CT scanning, the retrospective ECG-gating was applied and the optimal reconstruction intervals were determined. The accuracy of Doppler analysis to predict the optimal reconstruction intervals was tested. The predicted length of pulsing windows was compared between Doppler analysis and traditional prospective ECG-gating protocol (heart rate ≦ 65 bpm, 60–76%; 66–79 bpm, 30–77%; ≧80 bpm, 31–47%). Results: According to Doppler analysis, the mean length of intervals with minimal motion in systole was 106.4 ± 39.2 ms and 125.2 ± 92.0 ms in diastole. When the intervals with minimal motion during diastole > 90 ms, the optimal reconstruction intervals were located at diastole; otherwise, at systole (P < 0.001). The optimal reconstruction intervals in 93.8% (132/135) patients could be predicted accurately by Doppler analysis. If the optimal reconstruction intervals predicted by Doppler were applied as the exposure windows, the mean length of pulsing windows should has been 105.2 ± 69.4 ms (range: 26.9–510.3 ms), which was significantly shorter than that of traditional prospective ECG-gating protocol (232.0 ± 120.2 ms, range: 93.2–427.3 ms, P < 0.001). Conclusion: Doppler can help detecting the optimal pulsing windows accurately. Prospective ECG-gating incorporating Doppler analysis may narrow pulsing windows significantly while maintaining image quality.

  19. Transthoracic Doppler echocardiography to predict optimal tube pulsing window for coronary artery CT angiography

    International Nuclear Information System (INIS)

    Sun, Gang; Li, Min; Jiang, Xiang-sen; Li, Li; Peng, Zhao-hui; Mu, Nan-nan

    2012-01-01

    Rationale and objective: To evaluate the feasibility of transthoracic Doppler echocardiography to determine the optimal pulsing windows for CT coronary angiography to narrow the pulsing windows further, especially in higher heart rate. Materials and methods: Doppler was performed on 135 patients before CT scanning. For Doppler, the intervals with minimal motion were evaluated during both systole and diastole integrating electrocardiogram (ECG) intervals. For CT scanning, the retrospective ECG-gating was applied and the optimal reconstruction intervals were determined. The accuracy of Doppler analysis to predict the optimal reconstruction intervals was tested. The predicted length of pulsing windows was compared between Doppler analysis and traditional prospective ECG-gating protocol (heart rate ≦ 65 bpm, 60–76%; 66–79 bpm, 30–77%; ≧80 bpm, 31–47%). Results: According to Doppler analysis, the mean length of intervals with minimal motion in systole was 106.4 ± 39.2 ms and 125.2 ± 92.0 ms in diastole. When the intervals with minimal motion during diastole > 90 ms, the optimal reconstruction intervals were located at diastole; otherwise, at systole (P < 0.001). The optimal reconstruction intervals in 93.8% (132/135) patients could be predicted accurately by Doppler analysis. If the optimal reconstruction intervals predicted by Doppler were applied as the exposure windows, the mean length of pulsing windows should has been 105.2 ± 69.4 ms (range: 26.9–510.3 ms), which was significantly shorter than that of traditional prospective ECG-gating protocol (232.0 ± 120.2 ms, range: 93.2–427.3 ms, P < 0.001). Conclusion: Doppler can help detecting the optimal pulsing windows accurately. Prospective ECG-gating incorporating Doppler analysis may narrow pulsing windows significantly while maintaining image quality

  20. Three-dimensional power Doppler sonography in screening for carotid artery disease.

    Science.gov (United States)

    Keberle, M; Jenett, M; Beissert, M; Jahns, R; Haerten, R; Hahn, D

    2000-01-01

    Color Doppler sonography has gained considerable recognition as a noninvasive method to detect carotid artery disease and to assess the degree of carotid artery stenosis. However, results are highly operator-dependent and cannot be presented as survey images. The purpose of this study was to evaluate real-time 3-dimensional (3D) power Doppler sonography as a method for screening for atherosclerosis in the carotid arteries. We prospectively screened 75 patients for carotid artery disease using both conventional color Doppler sonography and 3D power Doppler sonography, and the results from the 2 modalities were compared. A total of 150 common carotid arteries, 150 internal carotid arteries, and 150 external carotid arteries were examined utilizing a 7.5-MHz linear-array transducer combined with tissue harmonic imaging. Color Doppler sonography detected 297 normal or atherosclerotic arteries without stenosis, 57 arteries with mild (1-49%) stenosis, 41 with moderate (50-69%) stenosis, 32 with severe (70-99%) stenosis, and 9 with occlusions. The degree of stenosis determined by color Doppler sonography correlated with that determined by 3D power Doppler sonography (r = 0.982-0.998). Moreover, there was a good correlation between the measurements for both the length of the lesion and its distance from the bulb as determined by the 3D volume surveys and by color Doppler sonography (r = 0.986). The interobserver variability rate was 3.7% +/- 0.5%. Generally, the acquisition and reconstruction of the 3D data took less than 5 minutes. 3D power Doppler sonography is easy to perform and is an accurate method in screening for atherosclerotic lesions of the carotid arteries. Moreover, it provides excellent 3D volume surveys that may be helpful in the planning of surgical treatment. Copyright 2000 John Wiley & Sons, Inc.

  1. Measurement of ventricular function using Doppler ultrasound

    International Nuclear Information System (INIS)

    Teague, S.M.

    1986-01-01

    Doppler has wide application in the evaluation of valvular heart disease. The need to know ventricular function is a much more common reason for an echocardiographic evaluation. Interestingly, Doppler examinations can assess ventricular function from many perspectives. Description of ventricular function entails measurement of the timing, rate and volume of ventricular filling and ejection. Doppler ultrasound examination reveals all of these aspects of ventricular function noninvasively, simply, and without great expense or radiation exposure, as described in this chapter

  2. Direct Doppler auscultation of the carotid arteries

    International Nuclear Information System (INIS)

    Nix, L.

    1984-01-01

    The results of the carotid Doppler examinations and contrast arteriograms are presented. The overall sensitivity of the carotid Doppler examinations in detecting severe stenosis or occlusion of the carotid artery was 92%. The Doppler studies correctly differentiated these two conditions in 84% of the diseased vessels. In carotid arteries with stenosis greater than or equal to 50%, the sensitivity of the Doppler examinations was 90%, and these studies suggested stenosis in all but two of the 36 abnormal examinations. In two patent carotids with greater than 90% stenosis, a signal could not be elicited, presumably because of the low blood flow through the severely stenotic segment

  3. Translation compensation and micro-Doppler extraction for precession ballistic targets with a wideband terahertz radar

    Science.gov (United States)

    Yang, Qi; Deng, Bin; Wang, Hongqiang; Zhang, Ye; Qin, Yuliang

    2018-01-01

    Imaging, classification, and recognition techniques of ballistic targets in midcourse have always been the focus of research in the radar field for military applications. However, the high velocity translation of ballistic targets will subject range profile and Doppler to translation, slope, and fold, which are especially severe in the terahertz region. Therefore, a two-step translation compensation method based on envelope alignment is presented. The rough compensation is based on the traditional envelope alignment algorithm in inverse synthetic aperture radar imaging, and the fine compensation is supported by distance fitting. Then, a wideband imaging radar system with a carrier frequency of 0.32 THz is introduced, and an experiment on a precession missile model is carried out. After translation compensation with the method proposed in this paper, the range profile and the micro-Doppler distributions unaffected by translation are obtained, providing an important foundation for the high-resolution imaging and micro-Doppler extraction of the terahertz radar.

  4. Analysis of placenta vascularization in patients with uterine altered artery Doppler flow velocity exams.

    Science.gov (United States)

    Gilio, Daniel Bruno; Miranda Corrêa, Rosana Rosa; Souza de Oliveira Guimarães, Camila; Peres, Luiz Cesar; Marques Salge, Ana Karina; Cavellani, Camila Lourencini; de Paula Antunes Teixeira, Vicente; Costa da Cunha Castro, Eumenia

    2009-08-01

    One of the frequent questions in obstetric practice is to determine placental vascular changes that may account for abnormal Doppler flow velocity alterations in maternal uterine vessels from women and fetuses without pregnancy pathology. A retrospective morphometric study was realized using 27 placentas from patients submitted for Doppler flow velocity exam during pregnancy. The placentas were morphologically examined using hematoxylin-eosin staining. Measurements of villi were made with the use of a video camera coupled to a common light microscope and a computer with automatic image analyzing software. Of the 27 placentas, 13 (48%) were of patients showing unaltered Doppler and 14 (52%) showing altered Doppler. The number of stem villi vessels was significantly larger in the placentas of patients with Doppler exam alterations (P = 0.003). This group also presented greater stem villi vessel thickness, although without significant difference. The number of intermediary and terminal villi vessels was greater in the placentas of patients with altered Doppler exams (P < 0.001), and a greater terminal villi area was observed in these cases (P < 0.001). The morphological proof that uterine artery Doppler flow velocity exam alterations are associated with placental vascular alterations demonstrates the importance of this exam during prenatal care, even in the absence of maternal-fetal alterations.

  5. [A new method of anti-jamming ability improvement for Michelson Interferometer].

    Science.gov (United States)

    Li, Yang-Jun; Lian, Su-Jie; Shi, Jia; Guo, Ya-Fei; Wang, Gao

    2014-05-01

    In order to improve anti-jamming capability of Michelson interferometer system, replace the traditional structure of the moving mirror scanning was replaced, an interference system based on electro-optic modulation of crystal refractive index was designed to achieve optical path scanning. The system modulated voltage signal on the variable refractive crystal, to generate cyclical changes, changed the refractive index to control optical path difference in the original optical path system. Using electronic scanning to replace of mechanical scanning, improved the system's noise immunity was improved. In the electro-optic modulation process, computed the maximum optical path difference of the system was computed, and analyzed of the crystal thickness and crystal diffraction efficiency of the modulation process were analyzed. The simulation experiment shows that, with the modulation voltage range increasing, the available range of the optical path is also increased, and the system spectrum resolving power will also increase accordingly. Meanwhile, in the modulation process set the modulation range was set to make the energy of diffraction energy losses less than 10% of the total energy, so as to ensure a better signal to noise ratio. Experimental results show that, as the modulation voltage changes, interference fringes occurred continuously moved. When the voltage is further increased, the nonlinear error appears. After non-linear error correction for the system, spectrum resolution reached to 7. 2 cm-1, slightly lower than the original system. But its anti-jamming capability is greatly enhanced, as in the absence of experimental platform for seismic conditions, conventional interferometer relative error is more than 20%, while the relative error of the system is less than 5%, in line with the design requirements. It was proved that the anti-jamming capability of the system was enhanced greatly, when the static electro-optical modulation was used.

  6. Michelson interferometer vibrometer using self-correcting synthetic-heterodyne demodulation.

    Science.gov (United States)

    Connelly, Michael J; Galeti, José Henrique; Kitano, Cláudio

    2015-06-20

    Synthetic-heterodyne demodulation is a useful technique for dynamic displacement and velocity detection in interferometric sensors, as it can provide an output signal that is immune to interferometric drift. With the advent of cost-effective, high-speed real-time signal-processing systems and software, processing of the complex signals encountered in interferometry has become more feasible. In synthetic heterodyne, to obtain the actual dynamic displacement or vibration of the object under test requires knowledge of the interferometer visibility and also the argument of two Bessel functions. In this paper, a method is described for determining the former and setting the Bessel function argument to a set value, which ensures maximum sensitivity. Conventional synthetic-heterodyne demodulation requires the use of two in-phase local oscillators; however, the relative phase of these oscillators relative to the interferometric signal is unknown. It is shown that, by using two additional quadrature local oscillators, a demodulated signal can be obtained that is independent of this phase difference. The experimental interferometer is a Michelson configuration using a visible single-mode laser, whose current is sinusoidally modulated at a frequency of 20 kHz. The detected interferometer output is acquired using a 250 kHz analog-to-digital converter and processed in real time. The system is used to measure the displacement sensitivity frequency response and linearity of a piezoelectric mirror shifter over a range of 500 Hz to 10 kHz. The experimental results show good agreement with two data-obtained independent techniques: the signal coincidence and denominated n-commuted Pernick method.

  7. Uranium hydrogeochemical and stream-sediment reconnaissance of the Mt. Michelson NTMS quadrangle, Alaska

    International Nuclear Information System (INIS)

    Zinkl, R.J.; Shettel, D.L. Jr.; Langfeldt, S.L.; Hardy, L.C.; D'Andrea, R.F. Jr.

    1982-04-01

    This report presents results of a Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Mt. Michelson NTMS quadrangle, Alaska. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form. These machine-readable data, as well as quarterly or semiannual program progress reports containing further information on the HSSR program in general, or on the Los Alamos National Laboratory (LANL) portion of the program in particular, are available from DOE's Technical Library at its Grand Junction Area Office. Presented in this data release are location data, field analyses, and laboratory analyses of several different sample media. For the sake of brevity, many field site observations have not been included in this volume; these data are, however, available on the magnetic tape. Appendices A and B describe the sample media and summarize the analytical results for each medium. The data have been subdivided by one of the Los Alamos National Laboratory sorting programs of Zinkl and others (1981a) into groups of stream-sediment and lake-sediment samples. For each group which contains a sufficient number of observations, statistical tables, tables of raw data, and 1:1,000,000 scale maps of pertinent elements have been included in this report. Also included are maps showing results of multivariate statistical analyses. Information on the field and analytical procedures used by the Los Alamos National Laboratory during sample collection and analysis may be found in any HSSR data release prepared by the Laboratory and will not be included in this report

  8. Low-frequency high-definition power Doppler in visualizing and defining fetal pulmonary venous connections.

    Science.gov (United States)

    Liu, Lin; He, Yihua; Li, Zhian; Gu, Xiaoyan; Zhang, Ye; Zhang, Lianzhong

    2014-07-01

    The use of low-frequency high-definition power Doppler in assessing and defining pulmonary venous connections was investigated. Study A included 260 fetuses at gestational ages ranging from 18 to 36 weeks. Pulmonary veins were assessed by performing two-dimensional B-mode imaging, color Doppler flow imaging (CDFI), and low-frequency high-definition power Doppler. A score of 1 was assigned if one pulmonary vein was visualized, 2 if two pulmonary veins were visualized, 3 if three pulmonary veins were visualized, and 4 if four pulmonary veins were visualized. The detection rate between Exam-1 and Exam-2 (intra-observer variability) and between Exam-1 and Exam-3 (inter-observer variability) was compared. In study B, five cases with abnormal pulmonary venous connection were diagnosed and compared to their anatomical examination. In study A, there was a significant difference between CDFI and low-frequency high-definition power Doppler for the four pulmonary veins observed (P low-frequency high-definition power Doppler was higher than that when employing two-dimensional B-mode imaging or CDFI. There was no significant difference between the intra- and inter-observer variabilities using low-frequency high-definition power Doppler display of pulmonary veins (P > 0.05). The coefficient correlation between Exam-1 and Exam-2 was 0.844, and the coefficient correlation between Exam-1 and Exam-3 was 0.821. In study B, one case of total anomalous pulmonary venous return and four cases of partial anomalous pulmonary venous return were diagnosed by low-frequency high-definition power Doppler and confirmed by autopsy. The assessment of pulmonary venous connections by low-frequency high-definition power Doppler is advantageous. Pulmonary venous anatomy can and should be monitored during fetal heart examination.

  9. Spatially Resolved MR-Compatible Doppler Ultrasound: Proof of Concept for Triggering of Diagnostic Quality Cardiovascular MRI for Function and Flow Quantification at 3T.

    Science.gov (United States)

    Crowe, Lindsey Alexandra; Manasseh, Gibran; Chmielewski, Aneta; Hachulla, Anne-Lise; Speicher, Daniel; Greiser, Andreas; Muller, Hajo; de Perrot, Thomas; Vallee, Jean-Paul; Salomir, Rares

    2018-02-01

    We demonstrate the use of a magnetic-resonance (MR)-compatible ultrasound (US) imaging probe using spatially resolved Doppler for diagnostic quality cardiovascular MR imaging (MRI) as an initial step toward hybrid US/MR fetal imaging. A newly developed technology for a dedicated MR-compatible phased array ultrasound-imaging probe acquired pulsed color Doppler carotid images, which were converted in near-real time to a trigger signal for cardiac cine and flow quantification MRI. Ultrasound and MR data acquired simultaneously were interference free. Conventional electrocardiogram (ECG) and the proposed spatially resolved Doppler triggering were compared in 10 healthy volunteers. A synthetic "false-triggered" image was retrospectively processed using metric optimized gating (MOG). Images were scored by expert readers, and sharpness, cardiac function and aortic flow were quantified. Four-dimensional (4-D) flow (two volunteers) showed feasibility of Doppler triggering over a long acquisition time. Imaging modalities were compatible. US probe positioning was stable and comfortable. Image quality scores and quantified sharpness were statistically equal for Doppler- and ECG-triggering (p ). ECG-, Doppler-triggered, and MOG ejection fractions were equivalent (p ), with false-triggered values significantly lower (p 0.05). 4-D flow quantification gave consistent results between ECG and Doppler triggering. We report interference-free pulsed color Doppler ultrasound during MR data acquisition. Cardiovascular MRI of diagnostic quality was successfully obtained with pulsed color Doppler triggering. The hardware platform could further enable advanced free-breathing cardiac imaging. Doppler ultrasound triggering is applicable where ECG is compromised due to pathology or interference at higher magnetic fields, and where direct ECG is impossible, i.e., fetal imaging.

  10. Doppler Aliasing Reduction in Wide-Angle Synthetic Aperture Radar Using Phase Modulated Random Stepped-Frequency Waveforms

    National Research Council Canada - National Science Library

    Hyatt, Andrew W

    2006-01-01

    ...) waveforms in a Wide-Angle Synthetic Aperture Radar (WA-SAR) scenario. RSF waveforms have been demonstrated to have desirable properties which allow for cancelling of Doppler aliased scatterers in WA-SAR images...

  11. All-silicon Michelson instrument on chip: Distance and surface profile measurement and prospects for visible light spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Malak, M.; Marty, F.; Bourouina, T. [Universite Paris-Est, Laboratoire ESYCOM, ESIEE Paris, Cite Descartes, 2 Boulevard Blaise Pascal, 93162 Noisy-le-Grand Cedex (France); Nouira, H.; Vailleau, G. [Laboratoire National de Metrologie et d' Essais, 1 rue Gaston Boissier, 75724 Paris Cedex 15 (France)

    2013-04-08

    A miniature Michelson interferometer is analyzed theoretically and experimentally. The fabricated micro-interferometer is incorporated at the tip of a monolithic silicon probe to achieve contactless distance measurements and surface profilometry. For infrared operation, two approaches are studied, based on the use of monochromatic light and wavelength sweep, respectively. A theoretical model is devised to depict the system characteristics taking into account Gaussian beam divergence and light spot size. Furthermore, preliminary results using visible light demonstrate operation of the probe as a visible light spectrometer, despite silicon absorbance, thanks to the micrometer thickness involved in the beam splitter.

  12. All-silicon Michelson instrument on chip: Distance and surface profile measurement and prospects for visible light spectrometry

    International Nuclear Information System (INIS)

    Malak, M.; Marty, F.; Bourouina, T.; Nouira, H.; Vailleau, G.

    2013-01-01

    A miniature Michelson interferometer is analyzed theoretically and experimentally. The fabricated micro-interferometer is incorporated at the tip of a monolithic silicon probe to achieve contactless distance measurements and surface profilometry. For infrared operation, two approaches are studied, based on the use of monochromatic light and wavelength sweep, respectively. A theoretical model is devised to depict the system characteristics taking into account Gaussian beam divergence and light spot size. Furthermore, preliminary results using visible light demonstrate operation of the probe as a visible light spectrometer, despite silicon absorbance, thanks to the micrometer thickness involved in the beam splitter.

  13. Laser phase and frequency noise measurement by Michelson interferometer composed of a 3 × 3 optical fiber coupler.

    Science.gov (United States)

    Xu, Dan; Yang, Fei; Chen, Dijun; Wei, Fang; Cai, Haiwen; Fang, Zujie; Qu, Ronghui

    2015-08-24

    A laser phase and frequency noise measurement method by an unbalanced Michelson interferometer composed of a 3 × 3 optical fiber coupler is proposed. The relations and differences of the power spectral density (PSD) of differential phase and frequency fluctuation, PSD of instantaneous phase and frequency fluctuation, phase noise and linewidth are derived strictly and discussed carefully. The method obtains the noise features of a narrow linewidth laser conveniently without any specific assumptions or noise models. The technique is also used to characterize the noise features of a narrow linewidth external-cavity semiconductor laser, which confirms the correction and robustness of the method.

  14. Spatio-temporal coherence of free-electron laser radiation in the extreme ultraviolet determined by a Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Hilbert, V.; Rödel, C.; Zastrau, U., E-mail: ulf.zastrau@uni-jena.de [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Brenner, G.; Düsterer, S.; Dziarzhytski, S.; Harmand, M.; Przystawik, A.; Redlin, H.; Toleikis, S. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Döppner, T.; Ma, T. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Fletcher, L. [Department of Physics, University of California, Berkeley, California 94720 (United States); Förster, E. [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena (Germany); Glenzer, S. H.; Lee, H. J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Hartley, N. J. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Kazak, L.; Komar, D.; Skruszewicz, S. [Institut für Physik, Universität Rostock, 18051 Rostock (Germany); and others

    2014-09-08

    A key feature of extreme ultraviolet (XUV) radiation from free-electron lasers (FELs) is its spatial and temporal coherence. We measured the spatio-temporal coherence properties of monochromatized FEL pulses at 13.5 nm using a Michelson interferometer. A temporal coherence time of (59±8) fs has been determined, which is in good agreement with the spectral bandwidth given by the monochromator. Moreover, the spatial coherence in vertical direction amounts to about 15% of the beam diameter and about 12% in horizontal direction. The feasibility of measuring spatio-temporal coherence properties of XUV FEL radiation using interferometric techniques advances machine operation and experimental studies significantly.

  15. Clinical study of color Doppler sonography in Graves' disease blood flow changes after thyroid arteries embolization

    International Nuclear Information System (INIS)

    Zhuang Wenquan; Li Weiduo; Yang Jianyong; Chen Wei; Huang Yonghui; Guo Wenbo; Li Jiaping

    2003-01-01

    Objective: To study the color doppler image characteristics of thyroid arteries pre- and post-interventional procedure and to assess the clinical efficacy in Gnaves' disease. Methods: 11 from 31 patients diagnosed as Graves' disease undertaken thyroid arteries embolization, were analyzed. Color Doppler sonography was applied to monitor the pre-and post- procedure thyroid size and diameters of thyroid arteries. Power Doppler was used to detect the Vmax, Vmin, RI and blood flow. Results: After thyroid arteries embolization, the size and vascularity of thyroids were reduced. The thyroid arteries showed shrinkage and stoppage blood flow at the embolized site. The changes of RI, blood parameters of Vmax, Vmin and diameters of the thyroid arteries pre- and post-procedure turned out to be statistically significant for clinical restriction. Conclusion: The color Doppler sonography plays an important role for preoperative diagnosis and predicting the prognosis

  16. Radar Doppler Processing with Nonuniform Sampling.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-07-01

    Conventional signal processing to estimate radar Doppler frequency often assumes uniform pulse/sample spacing. This is for the convenience of t he processing. More recent performance enhancements in processor capability allow optimally processing nonuniform pulse/sample spacing, thereby overcoming some of the baggage that attends uniform sampling, such as Doppler ambiguity and SNR losses due to sidelobe control measures.

  17. Prediction of cerebrovascular reserve by the MRI and doppler ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hui Joong; Kim, Yong Sun [Kyungpook National University Hospital, Daegu (Korea, Republic of)

    2005-07-15

    We investigated acute stroke patterns on diffusion weighted images and with doppler ultrasonography studies of ICA and MCA steno-occlusive diseases in order to predict the cerbrovascular reserve (CVR), as was measured by acetazolamide (ACZ)-challenged Tc-99m ECD brain perfusion SPECT. A retrospective analysis was performed of 76 patients who underwent MRI/MRA, ACZ-challenged Tc-99m ECD brain perfusion SPECT, and carotid and vertebral artery Doppler sonography. After dividing these patients into four groups-MCA and ICA ateno-occlusions, we analyzed the relationship between the CVR and topologic MR patterns and the flow volume, as was measured by Doppler sonography. The CVRs were preserved in 26 of 76 patients. The CVRs were impaired in those cases of occlusion that were detected on MRA and also by the pattern of the territorial involvement on the diffusion weighted image ({rho} < 0.05, x{sup 2} test). Yet in cases of preserved CVRs, the flow volume of the contralateral ICA, the anterior circulation, and the total cerebral flow volume were increased, as was checked by Doppler sonography ({rho} < 0.05, t-test). As calculated by logistic regression analysis, the accuracy for predicting the preserved CVR by using the statistically significant variables was 78%. We believe that the MRI-SPECT correlation study was helpful for understanding the hemodynamics and topographic patterns of ischemia in patients with ICA and MCA steno-occlusive disease, and that the flow volume measurement, which was done by using duplex US, was useful for predicting the CVR.

  18. Alveolar Echinococcosis of the Liver: Correlative Color Doppler US, CT, and MRI Study

    International Nuclear Information System (INIS)

    Cokun, A.; Oeztuerk, M.; Karahan, O.I.; Erdogan, N.; Ikin, S.; Guelec, M.

    2004-01-01

    Purpose: To determine and compare the imaging features of hepatic alveolar Echinococcosis using color Doppler US, CT, and MRI. Material and Methods: Abdominal CT and MRI with and without contrast agents and color Doppler US were performed on seven patients with hepatic alveolar Echinococcosis. The lesions were evaluated for location, features of echogenicity, intensity and density, calcification, and vascular, hilar, and perihepatic involvement. The diagnosis was confirmed histopathologically in all patients. Results: Six patients had solitary lesions, and one displayed multiple lesions. The lesions were generally seen as heterogeneous and hyper- or hypoechoic when imaged with color Doppler US, hypodense with CT, and hypointense with MRI, in comparison with the liver parenchyma. Calcification, central necrosis, and small peripheral cysts were observed in six, seven, and four patients, respectively. Vascular flow or contrast enhancement was not observed in any of the cases. A look at the respective advantages of each method reveals that calcification was best rendered visible via CT, small peripheral cysts with T2-weighted MRI, central necrosis with CT and MRI, and perihepatic invasion with multiplanar MRI. Vascular involvement was revealed by all methods. Conclusion: Color Doppler US, CT, and MR imaging function extremely well as complementary methods in the diagnosis of HAE. Color Doppler US should be performed in these patients owing to its ability to efficiently detect the disease. Knowledge of imaging characteristics makes it possible to radiologically ascertain an early diagnosis

  19. Estimating the Doppler centroid of SAR data

    DEFF Research Database (Denmark)

    Madsen, Søren Nørvang

    1989-01-01

    attractive properties. An evaluation based on an existing SEASAT processor is reported. The time-domain algorithms are shown to be extremely efficient with respect to requirements on calculations and memory, and hence they are well suited to real-time systems where the Doppler estimation is based on raw SAR......After reviewing frequency-domain techniques for estimating the Doppler centroid of synthetic-aperture radar (SAR) data, the author describes a time-domain method and highlights its advantages. In particular, a nonlinear time-domain algorithm called the sign-Doppler estimator (SDE) is shown to have...... data. For offline processors where the Doppler estimation is performed on processed data, which removes the problem of partial coverage of bright targets, the ΔE estimator and the CDE (correlation Doppler estimator) algorithm give similar performance. However, for nonhomogeneous scenes it is found...

  20. HIGH-RESOLUTION HELIOSEISMIC IMAGING OF SUBSURFACE STRUCTURES AND FLOWS OF A SOLAR ACTIVE REGION OBSERVED BY HINODE

    International Nuclear Information System (INIS)

    Zhao Junwei; Kosovichev, Alexander G.; Sekii, Takashi

    2010-01-01

    We analyze a solar active region observed by the Hinode Ca II H line using the time-distance helioseismology technique, and infer wave-speed perturbation structures and flow fields beneath the active region with a high spatial resolution. The general subsurface wave-speed structure is similar to the previous results obtained from Solar and Heliospheric Observatory/Michelson Doppler Imager observations. The general subsurface flow structure is also similar, and the downward flows beneath the sunspot and the mass circulations around the sunspot are clearly resolved. Below the sunspot, some organized divergent flow cells are observed, and these structures may indicate the existence of mesoscale convective motions. Near the light bridge inside the sunspot, hotter plasma is found beneath, and flows divergent from this area are observed. The Hinode data also allow us to investigate potential uncertainties caused by the use of phase-speed filter for short travel distances. Comparing the measurements with and without the phase-speed filtering, we find out that inside the sunspot, mean acoustic travel times are in basic agreement, but the values are underestimated by a factor of 20%-40% inside the sunspot umbra for measurements with the filtering. The initial acoustic tomography results from Hinode show a great potential of using high-resolution observations for probing the internal structure and dynamics of sunspots.