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Sample records for response imaging device

  1. Correction method and software for image distortion and nonuniform response in charge-coupled device-based x-ray detectors utilizing x-ray image intensifier

    International Nuclear Information System (INIS)

    Ito, Kazuki; Kamikubo, Hironari; Yagi, Naoto; Amemiya, Yoshiyuki

    2005-01-01

    An on-site method of correcting the image distortion and nonuniform response of a charge-coupled device (CCD)-based X-ray detector was developed using the response of the imaging plate as a reference. The CCD-based X-ray detector consists of a beryllium-windowed X-ray image intensifier (Be-XRII) and a CCD as the image sensor. An image distortion of 29% was improved to less than 1% after the correction. In the correction of nonuniform response due to image distortion, subpixel approximation was performed for the redistribution of pixel values. The optimal number of subpixels was also discussed. In an experiment with polystyrene (PS) latex, it was verified that the correction of both image distortion and nonuniform response worked properly. The correction for the 'contrast reduction' problem was also demonstrated for an isotropic X-ray scattering pattern from the PS latex. (author)

  2. Evaluating imaging devices

    International Nuclear Information System (INIS)

    Rollo, F.D.

    1977-01-01

    The performance of any imaging device depends on two principal factors inherent to the device, namely, plane sensitivity and spatial resolution. These factors may be defined as follows: plane sensitivity is the counts per second recorded by the imaging device for each disintegration per second per square centimeter occurring within a plane sheet of radioactivity. Spatial resolution may be defined as the fidelity with which the imaging device reproduces the activity distribution of an object in the image plane. In all imaging devices, a trade-off exists between these two parameters; that is, as sensitivity improves, spatial resolution is degraded, and vice versa. Therefore, to fully evaluate an imaging system a technique should be selected that measures both parameters and reflects the trade-off between the two. In addition, the method should approximate the clinical problem, namely, the detection of a focal lesion within an activity distribution. Several methods have been described to evaluate nuclear imaging devices. The more common techniques include the use of organ phantoms, bar phantoms, line-spread functions, modulation transfer functions, contrast efficiency functions, and performance index functions. Each of these techniques is briefly described in this chapter, and their advantages and disadvantages are discussed. In addition, a phantom that can be used to simply and completely measure overall imaging system performance is described

  3. Basic dose response of fluorescent screen-based portal imaging device

    International Nuclear Information System (INIS)

    Yeo, In Hwan; Yonannes, Yonas; Zhu, Yunping

    1999-01-01

    The purpose of this study is to investigate fundamental aspects of the dose response of fluorescent screen-based electronic portal imaging devices (EPIDs). We acquired scanned signal across portal planes as we varied the radiation that entered the EPID by changing the thickness and anatomy of the phantom as well as the air gap between the phantom and the EPID. In addition, we simulated the relative contribution of the scintillation light signal in the EPID system. We have shown that the dose profile across portal planes is a function of the air gap and phantom thickness. We have also found that depending on the density change within the phantom geometry, errors associated with dose response based on the EPID scan can be as high as 7%. We also found that scintillation light scattering within the EPID system is an important source of error. This study revealed and demonstrated fundamental characteristics of dose response of EPID, as relative to that of ion chambers. This study showed that EPID based on fluorescent screen cannot be an accurate dosimetry system

  4. Image Quality Characteristics of Handheld Display Devices for Medical Imaging

    Science.gov (United States)

    Yamazaki, Asumi; Liu, Peter; Cheng, Wei-Chung; Badano, Aldo

    2013-01-01

    Handheld devices such as mobile phones and tablet computers have become widespread with thousands of available software applications. Recently, handhelds are being proposed as part of medical imaging solutions, especially in emergency medicine, where immediate consultation is required. However, handheld devices differ significantly from medical workstation displays in terms of display characteristics. Moreover, the characteristics vary significantly among device types. We investigate the image quality characteristics of various handheld devices with respect to luminance response, spatial resolution, spatial noise, and reflectance. We show that the luminance characteristics of the handheld displays are different from those of workstation displays complying with grayscale standard target response suggesting that luminance calibration might be needed. Our results also demonstrate that the spatial characteristics of handhelds can surpass those of medical workstation displays particularly for recent generation devices. While a 5 mega-pixel monochrome workstation display has horizontal and vertical modulation transfer factors of 0.52 and 0.47 at the Nyquist frequency, the handheld displays released after 2011 can have values higher than 0.63 at the respective Nyquist frequencies. The noise power spectra for workstation displays are higher than 1.2×10−5 mm2 at 1 mm−1, while handheld displays have values lower than 3.7×10−6 mm2. Reflectance measurements on some of the handheld displays are consistent with measurements for workstation displays with, in some cases, low specular and diffuse reflectance coefficients. The variability of the characterization results among devices due to the different technological features indicates that image quality varies greatly among handheld display devices. PMID:24236113

  5. Study on the dose response characteristics of a scanning liquid ion-chamber electronic portal imaging device

    CERN Document Server

    Ma Shao Gang; Song Yi Xin

    2002-01-01

    Objective: To study the dose response characteristics and the influence factors such as gantry angle, field size and acquisition mode on the dosimetric response curves, when using a scanning liquid ion-chamber electronic portal imaging device (EPID) for dose verification. Methods: All experiments were carried out on a Varian 600 C/D accelerator (6 MV X-ray) equipped with a Varian PortalVision sup T sup M MK2 type EPID. To obtain the dose response curve, the relationship between the incident radiation intensity to the detector and the pixel value output from the EPID were established. Firstly, the different dose rates of 6 MV X-rays were obtained by varying SSD. Secondly, three digital portal images were acquired for each dose rate using the EPID and averaged to avoid the influence of the dose rate fluctuations of the accelerator. The pixel values of all images were read using self-designed image analysis software, and and average for a region consisting of 11 x 11 pixels around the center was taken as the res...

  6. The Image Transceiver Device: Studies of Improved Physical Design.

    Science.gov (United States)

    David, Yitzhak; Efron, Uzi

    2008-07-25

    The Image Transceiver Device (ITD) design is based on combining LCOS micro-display, image processing tools and back illuminated APS imager in single CMOS chip [1]. The device is under development for Head-Mounted Display applications in augmented and virtual reality systems. The main issues with the present design are a high crosstalk of the backside imager and the need to shield the pixel circuitry from the photocharges generated in the silicon substrate. In this publication we present a modified, "deep p-well" ITD pixel design, which provides a significantly reduced crosstalk level, as well as an effective shielding of photo-charges for the pixel circuitry. The simulation performed using Silvaco software [ATLAS Silicon Device Simulator, Ray Trace and Light Absorption programs, Silvaco International, 1998] shows that the new approach provides high photo response and allows increasing the optimal thickness of the die over and above the 10-15 micrometers commonly used for back illuminated imaging devices, thereby improving its mechanical ruggedness following the thinning process and also providing a more efficient absorption of the long wavelength photons. The proposed deep p-well pixel structure is also a technology solution for the fabrication of high performance back illuminated CMOS image sensors.

  7. The Image Transceiver Device: Studies of Improved Physical Design

    Directory of Open Access Journals (Sweden)

    Uzi Efron

    2008-07-01

    Full Text Available The Image Transceiver Device (ITD design is based on combining LCOS micro-display, image processing tools and back illuminated APS imager in single CMOS chip [1]. The device is under development for Head-Mounted Display applications in augmented and virtual reality systems. The main issues with the present design are a high crosstalk of the backside imager and the need to shield the pixel circuitry from the photocharges generated in the silicon substrate. In this publication we present a modified, “deep p-well” ITD pixel design, which provides a significantly reduced crosstalk level, as well as an effective shielding of photo-charges for the pixel circuitry. The simulation performed using Silvaco software [ATLAS Silicon Device Simulator, Ray Trace and Light Absorption programs, Silvaco International, 1998] shows that the new approach provides high photo response and allows increasing the optimal thickness of the die over and above the 10-15 micrometers commonly used for back illuminated imaging devices, thereby improving its mechanical ruggedness following the thinning process and also providing a more efficient absorption of the long wavelength photons. The proposed deep p-well pixel structure is also a technology solution for the fabrication of high performance back illuminated CMOS image sensors.

  8. Electronic portal imaging devices

    International Nuclear Information System (INIS)

    Lief, Eugene

    2008-01-01

    The topics discussed include, among others, the following: Role of portal imaging; Port films vs. EPID; Image guidance: Elekta volume view; Delivery verification; Automation tasks of portal imaging; Types of portal imaging (Fluorescent screen, mirror, and CCD camera-based imaging; Liquid ion chamber imaging; Amorpho-silicon portal imagers; Fluoroscopic portal imaging; Kodak CR reader; and Other types of portal imaging devices); QA of EPID; and Portal dosimetry (P.A.)

  9. 21 CFR 892.2040 - Medical image hardcopy device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical image hardcopy device. 892.2040 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.2040 Medical image hardcopy device. (a) Identification. A medical image hardcopy device is a device that produces a visible printed record of a medical...

  10. Laser-based irradiation apparatus and methods for monitoring the dose-rate response of semiconductor devices

    Science.gov (United States)

    Horn, Kevin M [Albuquerque, NM

    2006-03-28

    A scanned, pulsed, focused laser irradiation apparatus can measure and image the photocurrent collection resulting from a dose-rate equivalent exposure to infrared laser light across an entire silicon die. Comparisons of dose-rate response images or time-delay images from before, during, and after accelerated aging of a device, or from periodic sampling of devices from fielded operational systems allows precise identification of those specific age-affected circuit structures within a device that merit further quantitative analysis with targeted materials or electrical testing techniques. Another embodiment of the invention comprises a broad-beam, dose rate-equivalent exposure apparatus. The broad-beam laser irradiation apparatus can determine if aging has affected the device's overall functionality. This embodiment can be combined with the synchronized introduction of external electrical transients into a device under test to simulate the electrical effects of the surrounding circuitry's response to a radiation exposure.

  11. Use of mobile devices for medical imaging.

    Science.gov (United States)

    Hirschorn, David S; Choudhri, Asim F; Shih, George; Kim, Woojin

    2014-12-01

    Mobile devices have fundamentally changed personal computing, with many people forgoing the desktop and even laptop computer altogether in favor of a smaller, lighter, and cheaper device with a touch screen. Doctors and patients are beginning to expect medical images to be available on these devices for consultative viewing, if not actual diagnosis. However, this raises serious concerns with regard to the ability of existing mobile devices and networks to quickly and securely move these images. Medical images often come in large sets, which can bog down a network if not conveyed in an intelligent manner, and downloaded data on a mobile device are highly vulnerable to a breach of patient confidentiality should that device become lost or stolen. Some degree of regulation is needed to ensure that the software used to view these images allows all relevant medical information to be visible and manipulated in a clinically acceptable manner. There also needs to be a quality control mechanism to ensure that a device's display accurately conveys the image content without loss of contrast detail. Furthermore, not all mobile displays are appropriate for all types of images. The smaller displays of smart phones, for example, are not well suited for viewing entire chest radiographs, no matter how small and numerous the pixels of the display may be. All of these factors should be taken into account when deciding where, when, and how to use mobile devices for the display of medical images. Copyright © 2014 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  12. Nuclear Medicine Imaging Devices. Chapter 11

    Energy Technology Data Exchange (ETDEWEB)

    Lodge, M. A.; Frey, E. C. [Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD (United States)

    2014-12-15

    Imaging forms an important part of nuclear medicine and a number of different imaging devices have been developed. This chapter describes the principles and technological characteristics of the main imaging devices used in nuclear medicine. The two major categories are gamma camera systems and positron emission tomography (PET) systems. The former are used to image γ rays emitted by any nuclide, while the latter exploit the directional correlation between annihilation photons emitted by positron decay. The first section of this chapter discusses the principal components of gamma cameras and how they are used to form 2-D planar images as well as 3-D tomographic images (single photon emission computed tomography (SPECT)). The second section describes related instrumentation that has been optimized for PET data acquisition. A major advance in nuclear medicine was achieved with the introduction of multi-modality imaging systems including SPECT/computed tomography (CT) and PET/CT. In these systems, the CT images can be used to provide an anatomical context for the functional nuclear medicine images and allow for attenuation compensation. The third section in this chapter provides a discussion of the principles of these devices.

  13. Ceramic and polymeric devices for breast brachytherapy - Mammographic and CT response

    International Nuclear Information System (INIS)

    Nogueira, Luciana B.; Campos, Tarcisio P.R.

    2009-01-01

    The present research investigates the radiological visibility of ceramic and polymeric devices implanted in breast phantom (in vitro) for future applications in brachytherapy treatments. The main research goal is to investigate the viability of monitoring ceramic and polymeric devices, in vitro based on simple methods of radiological diagnostic, maintaining the easiest access to the population, represented by the conventional X-ray and mammography. The methodology involves the processing of ceramic devices constituted by bioglasses of Sm, SmBa, Ho, HoBa and the production of polymeric devices, such as polymeric membranes incorporating Ho e HoBa. Contrast agent of Barium was introduced in the syntheses of those devices to improve the radiological visibility in breast equivalent-tissue (TE) phantom. The breast phantom is constituted of glandular, adipose and skin TE, reproducing a 5 cm compressed real breast. In the compressed breast phantom, all types of ceramic and polymeric devices were implanted side by side. Radiological images were generated through X-ray equipment, mammography and computerized tomography (TC), for the samples implanted in the compressed breast phantom. The results show that SmBa and HoBa seeds on breast phantom presented suitable radiological visibility, on all the radiological diagnostic methods. However, the X-rays radiological visibility of Sm seeds without contrast was discreet. On mammography and TC images, it was not possible to identify those seeds, because the same ones were degraded after two months immersed in the glandular TE, after placed on the phantom. The Ho seeds were identified on all radiological diagnostic images, although non contrast agent in its constitution was added. However, the holmium polymeric membranes in direct contact with TE did not show Xray radiological visibility. However, the polymeric membranes of HoBa in the same conditions presented efficient X-rays radiological response. For mammography and TC methods

  14. Characterisation of a CMOS charge transfer device for TDI imaging

    International Nuclear Information System (INIS)

    Rushton, J.; Holland, A.; Stefanov, K.; Mayer, F.

    2015-01-01

    The performance of a prototype true charge transfer imaging sensor in CMOS is investigated. The finished device is destined for use in TDI applications, especially Earth-observation, and to this end radiation tolerance must be investigated. Before this, complete characterisation is required. This work starts by looking at charge transfer inefficiency and then investigates responsivity using mean-variance techniques

  15. Multimodality imaging of the Essure tubal occlusion device

    International Nuclear Information System (INIS)

    Simpson, W.L.; Beitia, L.

    2012-01-01

    The Essure device is a permanent birth-control device, which is gaining popularity. The micro-inserts are composed of metallic elements that can be seen on radiography, computed tomography, ultrasound, and magnetic resonance imaging. Knowledge of the normal location and appearance of the Essure device will ensure appropriate patient care. The purpose of this review is to describe the Essure tubal occlusion device and illustrate its normal and abnormal appearance using various imaging methods.

  16. A device for multimodal imaging of skin

    Science.gov (United States)

    Spigulis, Janis; Garancis, Valerijs; Rubins, Uldis; Zaharans, Eriks; Zaharans, Janis; Elste, Liene

    2013-03-01

    A compact prototype device for diagnostic imaging of skin has been developed and tested. Polarized LED light at several spectral regions is used for illumination, and round skin spot of diameter 30mm is imaged by a CMOS sensor via crossoriented polarizing filter. Four consecutive imaging series are performed: (1) RGB image at white LED illumination for revealing subcutaneous structures; (2) four spectral images at narrowband LED illumination (450nm, 540nm, 660nm, 940nm) for mapping of the main skin chromophores; (3) video-imaging under green LED illumination for mapping of skin blood perfusion; (4) autofluorescence video-imaging under UV (365nm) LED irradiation for mapping of the skin fluorophores. Design details of the device as well as preliminary results of clinical tests are presented.

  17. [Electronic Device for Retinal and Iris Imaging].

    Science.gov (United States)

    Drahanský, M; Kolář, R; Mňuk, T

    This paper describes design and construction of a new device for automatic capturing of eye retina and iris. This device has two possible ways of utilization - either for biometric purposes (persons recognition on the base of their eye characteristics) or for medical purposes as supporting diagnostic device. eye retina, eye iris, device, acquisition, image.

  18. Multimodality imaging of the Essure tubal occlusion device.

    Science.gov (United States)

    Simpson, W L; Beitia, L

    2012-12-01

    The Essure device is a permanent birth-control device, which is gaining popularity. The micro-inserts are composed of metallic elements that can be seen on radiography, computed tomography, ultrasound, and magnetic resonance imaging. Knowledge of the normal location and appearance of the Essure device will ensure appropriate patient care. The purpose of this review is to describe the Essure tubal occlusion device and illustrate its normal and abnormal appearance using various imaging methods. Copyright © 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  19. Parallel Processing of Images in Mobile Devices using BOINC

    Science.gov (United States)

    Curiel, Mariela; Calle, David F.; Santamaría, Alfredo S.; Suarez, David F.; Flórez, Leonardo

    2018-04-01

    Medical image processing helps health professionals make decisions for the diagnosis and treatment of patients. Since some algorithms for processing images require substantial amounts of resources, one could take advantage of distributed or parallel computing. A mobile grid can be an adequate computing infrastructure for this problem. A mobile grid is a grid that includes mobile devices as resource providers. In a previous step of this research, we selected BOINC as the infrastructure to build our mobile grid. However, parallel processing of images in mobile devices poses at least two important challenges: the execution of standard libraries for processing images and obtaining adequate performance when compared to desktop computers grids. By the time we started our research, the use of BOINC in mobile devices also involved two issues: a) the execution of programs in mobile devices required to modify the code to insert calls to the BOINC API, and b) the division of the image among the mobile devices as well as its merging required additional code in some BOINC components. This article presents answers to these four challenges.

  20. Parallel Processing of Images in Mobile Devices using BOINC

    Directory of Open Access Journals (Sweden)

    Curiel Mariela

    2018-04-01

    Full Text Available Medical image processing helps health professionals make decisions for the diagnosis and treatment of patients. Since some algorithms for processing images require substantial amounts of resources, one could take advantage of distributed or parallel computing. A mobile grid can be an adequate computing infrastructure for this problem. A mobile grid is a grid that includes mobile devices as resource providers. In a previous step of this research, we selected BOINC as the infrastructure to build our mobile grid. However, parallel processing of images in mobile devices poses at least two important challenges: the execution of standard libraries for processing images and obtaining adequate performance when compared to desktop computers grids. By the time we started our research, the use of BOINC in mobile devices also involved two issues: a the execution of programs in mobile devices required to modify the code to insert calls to the BOINC API, and b the division of the image among the mobile devices as well as its merging required additional code in some BOINC components. This article presents answers to these four challenges.

  1. The simulation of an imaging gamma-ray Compton backscattering device using GEANT4

    International Nuclear Information System (INIS)

    Flechas, D.; Cristancho, F.; Sarmiento, L.G.; Fajardo, E.

    2014-01-01

    A gamma-backscattering imaging device dubbed Compton Camera, developed at GSI (Darmstadt, Germany) and modified and studied at the Nuclear Physics Group of the National University of Colombia in Bogota, uses the back-to-back emission of two gamma rays in the positron annihilation to construct a bidimensional image that represents the distribution of matter in the field-of-view of the camera. This imaging capability can be used in a host of different situations, for example, to identify and study deposition and structural defects, and to help locating concealed objects, to name just two cases. In order to increase the understanding of the response of the Compton Camera and, in particular, its image formation process, and to assist in the data analysis, a simulation of the camera was developed using the GEANT4 simulation toolkit. In this work, the images resulting from different experimental conditions are shown. The simulated images and their comparison with the experimental ones already suggest methods to improve the present experimental device. (author)

  2. Microscopy imaging device with advanced imaging properties

    Science.gov (United States)

    Ghosh, Kunal; Burns, Laurie; El Gamal, Abbas; Schnitzer, Mark J.; Cocker, Eric; Ho, Tatt Wei

    2015-11-24

    Systems, methods and devices are implemented for microscope imaging solutions. One embodiment of the present disclosure is directed toward an epifluorescence microscope. The microscope includes an image capture circuit including an array of optical sensor. An optical arrangement is configured to direct excitation light of less than about 1 mW to a target object in a field of view of that is at least 0.5 mm.sup.2 and to direct epi-fluorescence emission caused by the excitation light to the array of optical sensors. The optical arrangement and array of optical sensors are each sufficiently close to the target object to provide at least 2.5 .mu.m resolution for an image of the field of view.

  3. HDR Image Quality Enhancement Based on Spatially Variant Retinal Response

    Directory of Open Access Journals (Sweden)

    Horiuchi Takahiko

    2010-01-01

    Full Text Available There is a growing demand for being able to display high dynamic range (HDR images on low dynamic range (LDR devices. Tone mapping is a process for enhancing HDR image quality on an LDR device by converting the tonal values of the original image from HDR to LDR. This paper proposes a new tone mapping algorithm for enhancing image quality by deriving a spatially-variant operator for imitating S-potential response in human retina, which efficiently improves local contrasts while conserving good global appearance. The proposed tone mapping operator is studied from a system construction point of view. It is found that the operator is regarded as a natural extension of the Retinex algorithm by adding a global adaptation process to the local adaptation. The feasibility of the proposed algorithm is examined in detail on experiments using standard HDR images and real HDR scene images, comparing with conventional tone mapping algorithms.

  4. Real-time computer treatment of THz passive device images with the high image quality

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.

    2012-06-01

    We demonstrate real-time computer code improving significantly the quality of images captured by the passive THz imaging system. The code is not only designed for a THz passive device: it can be applied to any kind of such devices and active THz imaging systems as well. We applied our code for computer processing of images captured by four passive THz imaging devices manufactured by different companies. It should be stressed that computer processing of images produced by different companies requires using the different spatial filters usually. The performance of current version of the computer code is greater than one image per second for a THz image having more than 5000 pixels and 24 bit number representation. Processing of THz single image produces about 20 images simultaneously corresponding to various spatial filters. The computer code allows increasing the number of pixels for processed images without noticeable reduction of image quality. The performance of the computer code can be increased many times using parallel algorithms for processing the image. We develop original spatial filters which allow one to see objects with sizes less than 2 cm. The imagery is produced by passive THz imaging devices which captured the images of objects hidden under opaque clothes. For images with high noise we develop an approach which results in suppression of the noise after using the computer processing and we obtain the good quality image. With the aim of illustrating the efficiency of the developed approach we demonstrate the detection of the liquid explosive, ordinary explosive, knife, pistol, metal plate, CD, ceramics, chocolate and other objects hidden under opaque clothes. The results demonstrate the high efficiency of our approach for the detection of hidden objects and they are a very promising solution for the security problem.

  5. Comprehensive model for predicting perceptual image quality of smart mobile devices.

    Science.gov (United States)

    Gong, Rui; Xu, Haisong; Luo, M R; Li, Haifeng

    2015-01-01

    An image quality model for smart mobile devices was proposed based on visual assessments of several image quality attributes. A series of psychophysical experiments were carried out on two kinds of smart mobile devices, i.e., smart phones and tablet computers, in which naturalness, colorfulness, brightness, contrast, sharpness, clearness, and overall image quality were visually evaluated under three lighting environments via categorical judgment method for various application types of test images. On the basis of Pearson correlation coefficients and factor analysis, the overall image quality could first be predicted by its two constituent attributes with multiple linear regression functions for different types of images, respectively, and then the mathematical expressions were built to link the constituent image quality attributes with the physical parameters of smart mobile devices and image appearance factors. The procedure and algorithms were applicable to various smart mobile devices, different lighting conditions, and multiple types of images, and performance was verified by the visual data.

  6. A quantitative image quality comparison of four different image guided radiotherapy devices

    International Nuclear Information System (INIS)

    Stuetzel, Julia; Oelfke, Uwe; Nill, Simeon

    2008-01-01

    Purpose: A study to quantitatively compare the image quality of four different image guided radiotherapy (IGRT) devices based on phantom measurements with respect to the additional dose delivered to the patient. Methods: Images of three different head-sized phantoms (diameter 16-18 cm) were acquired with the following four IGRT-CT solutions: (i) the Siemens Primatom single slice fan beam computed tomography (CT) scanner with an acceleration voltage of 130 kV, (ii) a Tomotherapy HI-ART II unit using a fan beam scanner with an energy of 3.5 MeV and (iii) the Siemens Artiste prototype, providing the possibility to perform kV (121 kV) and MV (6 MV) cone beam (CB) CTs. For each device three scan protocols (named low, normal, high) were selected to yield the same weighted computed tomography dose index (CTDI w ). Based on the individual inserts of the different phantoms the image quality achieved with each device at a certain dose level was characterized in terms of homogeneity, spatial resolution, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and electron density-to-CT-number conversion. Results: Based on the current findings for head-sized phantoms all devices show an electron density-to-CT-number conversion almost independent of the imaging parameters and hence can be suited for treatment planning purposes. The evaluation of the image quality, however, points out clear differences due to the different energies and geometries. The Primatom standard CT scanner shows throughout the best performance, especially for soft tissue contrast and spatial resolution with low imaging doses. Reasonable soft tissue contrast can be obtained with slightly higher doses compared to the CT scanner with the kVCB and the Tomotherapy unit. In order to get similar results with the MVCB system a much higher dose needs to be applied to the patient. Conclusion: Considering the entire investigations, especially in terms of contrast and spatial resolution, a rough tendency for

  7. Design Through Integration of On-Board Calibration Device with Imaging Spectroscopy Instruments

    Science.gov (United States)

    Stange, Michael

    2012-01-01

    The main purpose of the Airborne Visible and Infrared Imaging Spectroscopy (AVIRIS) project is to "identify, measure, and monitor constituents of the Earth's surface and atmosphere based on molecular absorption and particle scattering signatures." The project designs, builds, and tests various imaging spectroscopy instruments that use On-Board Calibration devices (OBC) to check the accuracy of the data collected by the spectrometers. The imaging instrument records the spectral signatures of light collected during flight. To verify the data is correct, the OBC shines light which is collected by the imaging spectrometer and compared against previous calibration data to track spectral response changes in the instrument. The spectral data has the calibration applied to it based on the readings from the OBC data in order to ensure accuracy.

  8. Making Image More Energy Efficient for OLED Smart Devices

    Directory of Open Access Journals (Sweden)

    Deguang Li

    2016-01-01

    Full Text Available Now, more and more mobile smart devices are emerging massively; energy consumption of these devices has become an important consideration due to the limitation of battery capacity. Displays are the dominant energy consuming component of battery-operated devices, giving rise to organic light-emitting diode (OLED as a new promising display technology, which consumes different power when displaying different content due to their emissive nature. Based on this property, we propose an approach to improve image energy efficiency on OLED displays by perceiving image content. The key idea of our approach is to eliminate undesired details while preserving the region of interest of the image by leveraging the color and spatial information. First, we use edge detection algorithm to extract region of interest (ROI of an image. Next, we gradually change luminance and saturation of region of noninterest (NON-ROI of the image. Then we perform detailed experiment and case study to validate our approach; experiment results show that our approach can save 22.5% energy on average while preserving high quality of the image.

  9. Endoscopic device for functional imaging of the retina

    Science.gov (United States)

    Barriga, Simon; Lohani, Sweyta; Martell, Bret; Soliz, Peter; Ts'o, Dan

    2011-03-01

    Non-invasive imaging of retinal function based on the recording of spatially distributed reflectance changes evoked by visual stimuli has to-date been performed primarily using modified commercial fundus cameras. We have constructed a prototype retinal functional imager, using a commercial endoscope (Storz) for the frontend optics, and a low-cost back-end that includes the needed dichroic beam splitter to separate the stimulus path from the imaging path. This device has been tested to demonstrate its performance for the delivery of adequate near infrared (NIR) illumination, intensity of the visual stimulus and reflectance return in the imaging path. The current device was found to be capable of imaging reflectance changes of 0.1%, similar to that observable using the modified commercial fundus camera approach. The visual stimulus (a 505nm spot of 0.5secs) was used with an interrogation illumination of 780nm, and a sequence of imaged captured. At each pixel, the imaged signal was subtracted and normalized by the baseline reflectance, so that the measurement was ΔR/R. The typical retinal activity signal observed had a ΔR/R of 0.3-1.0%. The noise levels were measured when no stimulus was applied and found to vary between +/- 0.05%. Functional imaging has been suggested as a means to provide objective information on retina function that may be a preclinical indicator of ocular diseases, such as age-related macular degeneration (AMD), glaucoma, and diabetic retinopathy. The endoscopic approach promises to yield a significantly more economical retinal functional imaging device that would be clinically important.

  10. Image-based surveillance and security systems using personal computers for device aiming and digital image comparison

    International Nuclear Information System (INIS)

    Quiett, S.; Axtell, L.H.

    1987-01-01

    A detection-type security system using enhanced capability cameras or other imaging devices can aid in maintaining security from long distance and/or for large areas. To do so requires that the imaging device(s) be repeatedly and accurately positioned so that no areas are overlooked. Digital control using personal computers is the simplest method of achieving positional accuracy. The monitoring of large areas and/or a large number of areas also requires that a substantial quantity of visual information be catalogued and evaluated for potential security problems. While security personnel alone are typically used for such monitoring, as the quantity of visual information increases, the likelihood that potential security threats will be missed also increases. The ability of an image-based security system to detect potential security problems can be further increased with the use of selected image processing techniques. Utilizing personal computers for both imaging device position control as well as image processing, surveillance of large areas can be performed by a limited number of individuals with a high level of system confidence

  11. Signal Normalization Reduces Image Appearance Disparity Among Multiple Optical Coherence Tomography Devices.

    Science.gov (United States)

    Chen, Chieh-Li; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A; Kagemann, Larry; Schuman, Joel S

    2017-02-01

    To assess the effect of the previously reported optical coherence tomography (OCT) signal normalization method on reducing the discrepancies in image appearance among spectral-domain OCT (SD-OCT) devices. Healthy eyes and eyes with various retinal pathologies were scanned at the macular region using similar volumetric scan patterns with at least two out of three SD-OCT devices at the same visit (Cirrus HD-OCT, Zeiss, Dublin, CA; RTVue, Optovue, Fremont, CA; and Spectralis, Heidelberg Engineering, Heidelberg, Germany). All the images were processed with the signal normalization. A set of images formed a questionnaire with 24 pairs of cross-sectional images from each eye with any combination of the three SD-OCT devices either both pre- or postsignal normalization. Observers were asked to evaluate the similarity of the two displayed images based on the image appearance. The effects on reducing the differences in image appearance before and after processing were analyzed. Twenty-nine researchers familiar with OCT images participated in the survey. Image similarity was significantly improved after signal normalization for all three combinations ( P ≤ 0.009) as Cirrus and RTVue combination became the most similar pair, followed by Cirrus and Spectralis, and RTVue and Spectralis. The signal normalization successfully minimized the disparities in the image appearance among multiple SD-OCT devices, allowing clinical interpretation and comparison of OCT images regardless of the device differences. The signal normalization would enable direct OCT images comparisons without concerning about device differences and broaden OCT usage by enabling long-term follow-ups and data sharing.

  12. Informatics in radiology: Efficiency metrics for imaging device productivity.

    Science.gov (United States)

    Hu, Mengqi; Pavlicek, William; Liu, Patrick T; Zhang, Muhong; Langer, Steve G; Wang, Shanshan; Place, Vicki; Miranda, Rafael; Wu, Teresa Tong

    2011-01-01

    Acute awareness of the costs associated with medical imaging equipment is an ever-present aspect of the current healthcare debate. However, the monitoring of productivity associated with expensive imaging devices is likely to be labor intensive, relies on summary statistics, and lacks accepted and standardized benchmarks of efficiency. In the context of the general Six Sigma DMAIC (design, measure, analyze, improve, and control) process, a World Wide Web-based productivity tool called the Imaging Exam Time Monitor was developed to accurately and remotely monitor imaging efficiency with use of Digital Imaging and Communications in Medicine (DICOM) combined with a picture archiving and communication system. Five device efficiency metrics-examination duration, table utilization, interpatient time, appointment interval time, and interseries time-were derived from DICOM values. These metrics allow the standardized measurement of productivity, to facilitate the comparative evaluation of imaging equipment use and ongoing efforts to improve efficiency. A relational database was constructed to store patient imaging data, along with device- and examination-related data. The database provides full access to ad hoc queries and can automatically generate detailed reports for administrative and business use, thereby allowing staff to monitor data for trends and to better identify possible changes that could lead to improved productivity and reduced costs in association with imaging services. © RSNA, 2011.

  13. Content analysis of Australian direct-to-consumer websites for emerging breast cancer imaging devices.

    Science.gov (United States)

    Vreugdenburg, Thomas D; Laurence, Caroline O; Willis, Cameron D; Mundy, Linda; Hiller, Janet E

    2014-09-01

    To describe the nature and frequency of information presented on direct-to-consumer websites for emerging breast cancer imaging devices. Content analysis of Australian website advertisements from 2 March 2011 to 30 March 2012, for three emerging breast cancer imaging devices: digital infrared thermal imaging, electrical impedance scanning and electronic palpation imaging. Type of imaging offered, device safety, device performance, application of device, target population, supporting evidence and comparator tests. Thirty-nine unique Australian websites promoting a direct-to-consumer breast imaging device were identified. Despite a lack of supporting evidence, 22 websites advertised devices for diagnosis, 20 advertised devices for screening, 13 advertised devices for prevention and 13 advertised devices for identifying breast cancer risk factors. Similarly, advertised ranges of diagnostic sensitivity (78%-99%) and specificity (44%-91%) were relatively high compared with published literature. Direct comparisons with conventional screening tools that favoured the new device were highly prominent (31 websites), and one-third of websites (12) explicitly promoted their device as a suitable alternative. Australian websites for emerging breast imaging devices, which are also available internationally, promote the use of such devices as safe and effective solutions for breast cancer screening and diagnosis in a range of target populations. Many of these claims are not supported by peer-reviewed evidence, raising questions about the manner in which these devices and their advertising material are regulated, particularly when they are promoted as direct alternatives to established screening interventions.

  14. Development of a human body RMN imaging device

    International Nuclear Information System (INIS)

    Saint-Jalmes, H.

    1984-03-01

    Imaging device for human body is studied in this thesis. The section images presented are got by a projection-reconstruction method associated to a section plane selection by an oscillating gradient application. Different stages of the machine development are presented: - design and calculation of a resistive magnet for very homogeneous field imaging - design of gradient coils for imaging magnets - realization of control and acquisition interfaces - realization of imaging software in real time [fr

  15. Image quality and stability of image-guided radiotherapy (IGRT) devices: A comparative study.

    Science.gov (United States)

    Stock, Markus; Pasler, Marlies; Birkfellner, Wolfgang; Homolka, Peter; Poetter, Richard; Georg, Dietmar

    2009-10-01

    Our aim was to implement standards for quality assurance of IGRT devices used in our department and to compare their performances with that of a CT simulator. We investigated image quality parameters for three devices over a period of 16months. A multislice CT was used as a benchmark and results related to noise, spatial resolution, low contrast visibility (LCV) and uniformity were compared with a cone beam CT (CBCT) at a linac and simulator. All devices performed well in terms of LCV and, in fact, exceeded vendor specifications. MTF was comparable between CT and linac CBCT. Integral nonuniformity was, on average, 0.002 for the CT and 0.006 for the linac CBCT. Uniformity, LCV and MTF varied depending on the protocols used for the linac CBCT. Contrast-to-noise ratio was an average of 51% higher for the CT than for the linac and simulator CBCT. No significant time trend was observed and tolerance limits were implemented. Reasonable differences in image quality between CT and CBCT were observed. Further research and development are necessary to increase image quality of commercially available CBCT devices in order for them to serve the needs for adaptive and/or online planning.

  16. 21 CFR 892.2010 - Medical image storage device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical image storage device. 892.2010 Section 892.2010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED..., and digital memory. (b) Classification. Class I (general controls). The device is exempt from the...

  17. An image scanning device using radiating energy

    International Nuclear Information System (INIS)

    Jacob, Daniel.

    1976-01-01

    Said invention relates to an image scanning device using radiating energy. More particularly, it relates to a device for generating a scanning beam of rectangular cross section from a γ or X-ray source. Said invention can be applied to radiographic units of the 'microdose' type used by airline staffs and others for the fast efficient inspection of luggage and parcels in view of detecting hidden things [fr

  18. Single-Image Distance Measurement by a Smart Mobile Device.

    Science.gov (United States)

    Chen, Shangwen; Fang, Xianyong; Shen, Jianbing; Wang, Linbo; Shao, Ling

    2017-12-01

    Existing distance measurement methods either require multiple images and special photographing poses or only measure the height with a special view configuration. We propose a novel image-based method that can measure various types of distance from single image captured by a smart mobile device. The embedded accelerometer is used to determine the view orientation of the device. Consequently, pixels can be back-projected to the ground, thanks to the efficient calibration method using two known distances. Then the distance in pixel is transformed to a real distance in centimeter with a linear model parameterized by the magnification ratio. Various types of distance specified in the image can be computed accordingly. Experimental results demonstrate the effectiveness of the proposed method.

  19. Image quality and stability of image-guided radiotherapy (IGRT) devices: A comparative study

    International Nuclear Information System (INIS)

    Stock, Markus; Pasler, Marlies; Birkfellner, Wolfgang; Homolka, Peter; Poetter, Richard; Georg, Dietmar

    2009-01-01

    Introduction: Our aim was to implement standards for quality assurance of IGRT devices used in our department and to compare their performances with that of a CT simulator. Materials and methods: We investigated image quality parameters for three devices over a period of 16 months. A multislice CT was used as a benchmark and results related to noise, spatial resolution, low contrast visibility (LCV) and uniformity were compared with a cone beam CT (CBCT) at a linac and simulator. Results: All devices performed well in terms of LCV and, in fact, exceeded vendor specifications. MTF was comparable between CT and linac CBCT. Integral nonuniformity was, on average, 0.002 for the CT and 0.006 for the linac CBCT. Uniformity, LCV and MTF varied depending on the protocols used for the linac CBCT. Contrast-to-noise ratio was an average of 51% higher for the CT than for the linac and simulator CBCT. No significant time trend was observed and tolerance limits were implemented. Discussion: Reasonable differences in image quality between CT and CBCT were observed. Further research and development are necessary to increase image quality of commercially available CBCT devices in order for them to serve the needs for adaptive and/or online planning.

  20. Metrological characterization of 3D imaging devices

    Science.gov (United States)

    Guidi, G.

    2013-04-01

    Manufacturers often express the performance of a 3D imaging device in various non-uniform ways for the lack of internationally recognized standard requirements for metrological parameters able to identify the capability of capturing a real scene. For this reason several national and international organizations in the last ten years have been developing protocols for verifying such performance. Ranging from VDI/VDE 2634, published by the Association of German Engineers and oriented to the world of mechanical 3D measurements (triangulation-based devices), to the ASTM technical committee E57, working also on laser systems based on direct range detection (TOF, Phase Shift, FM-CW, flash LADAR), this paper shows the state of the art about the characterization of active range devices, with special emphasis on measurement uncertainty, accuracy and resolution. Most of these protocols are based on special objects whose shape and size are certified with a known level of accuracy. By capturing the 3D shape of such objects with a range device, a comparison between the measured points and the theoretical shape they should represent is possible. The actual deviations can be directly analyzed or some derived parameters can be obtained (e.g. angles between planes, distances between barycenters of spheres rigidly connected, frequency domain parameters, etc.). This paper shows theoretical aspects and experimental results of some novel characterization methods applied to different categories of active 3D imaging devices based on both principles of triangulation and direct range detection.

  1. A new 3-dimensional head fixation device for brain imaging

    International Nuclear Information System (INIS)

    Goto, Ryoi; Kawashima, Ryuta; Yoshioka, Seiro; Ono, Shuichi; Ito, Hiroshi; Sato, Kazunori; Akaizawa, Takashi; Koyama, Masamichi; Fukuda, Hiroshi

    1995-01-01

    We have developed a new head fixation device for studies of brain function. This device was designed to immobilize subject's heads during image scanning and to precisely reproduce the head position for two different imaging modalities such as MRI and PET. The device consists of a plastic frame, a pillow filled with beads of styrene foam, and a face mask of thermoplastic resin which was originally intended for application in radiotherapy. A bridge for biting was incorporated into the mask for stable fixation. The device enables immobilization of subject's heads with good reproducibility of position at the practical level. Our results indicate that this head fixation system is useful for fixation of head during activation studies using PET. (author)

  2. Post-operative orbital imaging: a focus on implants and prosthetic devices

    International Nuclear Information System (INIS)

    Adams, Ashok; Mankad, Kshitij; Poitelea, Cornelia; Verity, David H.; Davagnanam, Indran

    2014-01-01

    Accurate interpretation of orbital imaging in the presence of either orbital implants requires a sound knowledge of both the surgical approach used and the imaging characteristics of the implanted devices themselves. In this article, the radiological appearance of the various devices used in ophthalmology, and their relationship to other orbital structures, is reviewed. In addition, the intended anatomical location, function of these devices, and clinical indications for their use are provided. (orig.)

  3. Movable collimator for positron annihilation imaging device

    International Nuclear Information System (INIS)

    Thompson, C.J.

    1982-01-01

    A positron annihilation imaging device has two or more rings of detectors from which three or more slices through the object being scanned can be determined at once. A technique is provided for adjusting the slice widths. One slice may be imaged by all detectors in adjacent planes simultaneously, and reconstructed as if all detectors were in the same plane. The single slice facility is provided without the necessity of rotating the detector array or moving it in any way during data collection, allowing the possibility of doing physiologically gated imaging of a single slice

  4. Sweep devices for picosecond image-converter streak cameras

    International Nuclear Information System (INIS)

    Cunin, B.; Miehe, J.A.; Sipp, B.; Schelev, M.Ya.; Serduchenko, J.N.; Thebault, J.

    1979-01-01

    Four different sweep devices based on microwave tubes, avalanche transistors, krytrons, and laser-triggered spark gaps are treated in detail. These control circuits are developed for picosecond image-converter cameras and generate sweep pulses providing streak speeds in the range of 10 7 to 5x10 10 cm/sec with maximum time resolution better than 10 -12 sec. Special low-jitter triggering schemes reduce the jitter to less than 5x10 -11 sec. Some problems arising in the construction and matching of the sweep devices and image-streak tube are discussed. Comparative parameters of nanosecond switching elements are presented. The results described can be used by other authors involved in streak camera development

  5. The digital radiographic and computed tomography imaging of two types of explosive devices

    International Nuclear Information System (INIS)

    Galiano Riveros, Eduardo

    2002-01-01

    Two well-established medical imaging methods, digital radiography (DR) and computed tomography (CT), were employed to obtain images of two types of explosive devices, model rocket engines and shotgun shells. The images were evaluated from an airport security perspective. In terms of geometrical shape, the detection probability of the explosive devices appears to be higher with DR imaging, but in terms of the actual explosive compounds in the devices, CT appears to offer a higher detection probability. DR imaging offers a low detection probability for the explosive powder in the shotgun shells, but a rather significant detection probability for the explosive propellant in the model rocket engines

  6. Image timing and detector performance of a matrix ion-chamber electronic portal imaging device

    International Nuclear Information System (INIS)

    Greer, P.

    1996-01-01

    The Oncology Centre of Auckland Hospital recently purchased a Varian PortalVision TM electronic portal imaging device (EPID). Image acquisition times, input-output characteristics and contrast-detail curves of this matrix liquid ion-chamber EPID have been measured to examine the variation in imaging performance with acquisition mode. The variation in detector performance with acquisition mode has been examined. The HV cycle time can be increased to improve image quality. Consideration should be given to the acquisition mode and HV cycle time used when imaging to ensure adequate imaging performance with reasonable imaging time. (author)

  7. Three-dimensional image acquisition and reconstruction system on a mobile device based on computer-generated integral imaging.

    Science.gov (United States)

    Erdenebat, Munkh-Uchral; Kim, Byeong-Jun; Piao, Yan-Ling; Park, Seo-Yeon; Kwon, Ki-Chul; Piao, Mei-Lan; Yoo, Kwan-Hee; Kim, Nam

    2017-10-01

    A mobile three-dimensional image acquisition and reconstruction system using a computer-generated integral imaging technique is proposed. A depth camera connected to the mobile device acquires the color and depth data of a real object simultaneously, and an elemental image array is generated based on the original three-dimensional information for the object, with lens array specifications input into the mobile device. The three-dimensional visualization of the real object is reconstructed on the mobile display through optical or digital reconstruction methods. The proposed system is implemented successfully and the experimental results certify that the system is an effective and interesting method of displaying real three-dimensional content on a mobile device.

  8. Implementation of synthetic aperture imaging on a hand-held device

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Kjeldsen, Thomas; Larsen, Lee

    2014-01-01

    -held devices all with different chipsets and a BK Medical UltraView 800 ultrasound scanner emulating a wireless probe. The wireless transmission is benchmarked using an imaging setup consisting of 269 scan lines x 1472 complex samples (1.58 MB pr. frame, 16 frames per second). The measured data throughput...... reached an average of 28.8 MB/s using a LG G2 mobile device, which is more than the required data throughput of 25.3 MB/s. Benchmarking the processing performance for B-mode imaging showed a total processing time of 18.9 ms (53 frames/s), which is less than the acquisition time (62.5 ms).......This paper presents several implementations of Syn- thetic Aperture Sequential Beamforming (SASB) on commer- cially available hand-held devices. The implementations include real-time wireless reception of ultrasound radio frequency sig- nals and GPU processing for B-mode imaging. The proposed...

  9. Door and window image-based measurement using a mobile device

    Science.gov (United States)

    Ma, Guangyao; Janakaraj, Manishankar; Agam, Gady

    2015-03-01

    We present a system for door and window image-based measurement using an Android mobile device. In this system a user takes an image of a door or window that needs to be measured and using interaction measures specific dimensions of the object. The existing object is removed from the image and a 3D model of a replacement is rendered onto the image. The visualization provides a 3D model with which the user can interact. When tested on a mobile Android platform with an 8MP camera we obtain an average measurement error of roughly 0.5%. This error rate is stable across a range of view angles, distances from the object, and image resolutions. The main advantages of our mobile device application for image measurement include measuring objects for which physical access is not readily available, documenting in a precise manner the locations in the scene where the measurements were taken, and visualizing a new object with custom selections inside the original view.

  10. Modeling a color-rendering operator for high dynamic range images using a cone-response function

    Science.gov (United States)

    Choi, Ho-Hyoung; Kim, Gi-Seok; Yun, Byoung-Ju

    2015-09-01

    Tone-mapping operators are the typical algorithms designed to produce visibility and the overall impression of brightness, contrast, and color of high dynamic range (HDR) images on low dynamic range (LDR) display devices. Although several new tone-mapping operators have been proposed in recent years, the results of these operators have not matched those of the psychophysical experiments based on the human visual system. A color-rendering model that is a combination of tone-mapping and cone-response functions using an XYZ tristimulus color space is presented. In the proposed method, the tone-mapping operator produces visibility and the overall impression of brightness, contrast, and color in HDR images when mapped onto relatively LDR devices. The tone-mapping resultant image is obtained using chromatic and achromatic colors to avoid well-known color distortions shown in the conventional methods. The resulting image is then processed with a cone-response function wherein emphasis is placed on human visual perception (HVP). The proposed method covers the mismatch between the actual scene and the rendered image based on HVP. The experimental results show that the proposed method yields an improved color-rendering performance compared to conventional methods.

  11. Prospective clinical evaluation of an electronic portal imaging device

    International Nuclear Information System (INIS)

    Michalski, Jeff M.; Graham, Mary V.; Bosch, Walter R.; Wong, John; Gerber, Russell L.; Cheng, Abel; Tinger, Alfred; Valicenti, Richard K.

    1996-01-01

    Purpose: To determine whether the clinical implementation of an electronic portal imaging device can improve the precision of daily external beam radiotherapy. Methods and Materials: In 1991, an electronic portal imaging device was installed on a dual energy linear accelerator in our clinic. After training the radiotherapy technologists in the acquisition and evaluation of portal images, we performed a randomized study to determine whether online observation, interruption, and intervention would result in more precise daily setup. The patients were randomized to one of two groups: those whose treatments were actively monitored by the radiotherapy technologists and those that were imaged but not monitored. The treating technologists were instructed to correct the following treatment errors: (a) field placement error (FPE) > 1 cm; (b) incorrect block; (c) incorrect collimator setting; (d) absent customized block. Time of treatment delivery was recorded by our patient tracking and billing computers and compared to a matched set of patients not participating in the study. After the patients radiation therapy course was completed, an offline analysis of the patient setup error was planned. Results: Thirty-two patients were treated to 34 anatomical sites in this study. In 893 treatment sessions, 1,873 fields were treated (1,089 fields monitored and 794 fields unmonitored). Ninety percent of the treated fields had at least one image stored for offline analysis. Eighty-seven percent of these images were analyzed offline. Of the 1,011 fields imaged in the monitored arm, only 14 (1.4%) had an intervention recorded by the technologist. Despite infrequent online intervention, offline analysis demonstrated that the incidence of FPE > 10 mm in the monitored and unmonitored groups was 56 out of 881 (6.1%) and 95 out of 595 (11.2%), respectively; p 10 mm was confined to the pelvic fields. The time to treat patients in this study was 10.78 min (monitored) and 10.10 min (unmonitored

  12. Concave omnidirectional imaging device for cylindrical object based on catadioptric panoramic imaging

    Science.gov (United States)

    Wu, Xiaojun; Wu, Yumei; Wen, Peizhi

    2018-03-01

    To obtain information on the outer surface of a cylinder object, we propose a catadioptric panoramic imaging system based on the principle of uniform spatial resolution for vertical scenes. First, the influence of the projection-equation coefficients on the spatial resolution and astigmatism of the panoramic system are discussed, respectively. Through parameter optimization, we obtain the appropriate coefficients for the projection equation, and so the imaging quality of the entire imaging system can reach an optimum value. Finally, the system projection equation is calibrated, and an undistorted rectangular panoramic image is obtained using the cylindrical-surface projection expansion method. The proposed 360-deg panoramic-imaging device overcomes the shortcomings of existing surface panoramic-imaging methods, and it has the advantages of low cost, simple structure, high imaging quality, and small distortion, etc. The experimental results show the effectiveness of the proposed method.

  13. Movable collimator for positron annihilation imaging device

    International Nuclear Information System (INIS)

    Thompson, C.J.

    1981-01-01

    A positron annihilation imaging device having two circular arrays of detectors disposed in spaced apart parallel planes wherein axially movable annular collimator rings are generally disposed in a pair of opposite planes outside the associated planes of the collimators to each collimator being movable toward the opposite collimator and a central collimator of annular configuration generally disposed between the two rows of detectors but being split into two rings which may be separated, the outer and inner collimators serving to enhance data readout and imaging

  14. X-ray imaging device for one-dimensional and two-dimensional radioscopy

    International Nuclear Information System (INIS)

    1978-01-01

    The X-ray imaging device for the selectable one-dimensional or two-dimensional pictures of objects illuminated by X-rays, comprising an X-ray source, an X-ray screen, and an opto-electrical picture development device placed behind the screen, is characterized by an anamorphotic optical system, which is positioned with a one-dimensional illumination between the X-ray screen and the opto-electrical device and that a two-dimensional illumination will be developed, and that in view of the lens system which forms part of the opto-electrical device, there is placed an X-ray screen in a specified beam direction so that a magnified image may be formed by equalisation of the distance between the X-ray screen and the lens system. (G.C.)

  15. Development of a model using narrow slit beam profiles to account for the backscatter response of an amorphous silicon electronic portal imaging device

    International Nuclear Information System (INIS)

    Maria Das, K.J.; Ostapiak, Orest

    2008-01-01

    An electronic portal imaging device (EPID), currently used for determining proper patient placement during irradiation in a radiotherapy treatment, can also be used for the purpose of pre- treatment IMRT QA. However, the Varian aS500 portal imager exhibits dosimetric artifacts caused by non-uniform backscatter from mechanical support structures located behind the imager

  16. A review of performance of near-infrared fluorescence imaging devices used in clinical studies

    Science.gov (United States)

    Zhu, B

    2015-01-01

    Near-infrared fluorescence (NIRF) molecular imaging holds great promise as a new “point-of-care” medical imaging modality that can potentially provide the sensitivity of nuclear medicine techniques, but without the radioactivity that can otherwise place limitations of usage. Recently, NIRF imaging devices of a variety of designs have emerged in the market and in investigational clinical studies using indocyanine green (ICG) as a non-targeting NIRF contrast agent to demark the blood and lymphatic vasculatures both non-invasively and intraoperatively. Approved in the USA since 1956 for intravenous administration, ICG has been more recently used off label in intradermal or subcutaneous administrations for fluorescence imaging of the lymphatic vasculature and lymph nodes. Herein, we summarize the devices of a variety of designs, summarize their performance in lymphatic imaging in a tabular format and comment on necessary efforts to develop standards for device performance to compare and use these emerging devices in future, NIRF molecular imaging studies. PMID:25410320

  17. Electronics Related to Nuclear Medicine Imaging Devices. Chapter 7

    Energy Technology Data Exchange (ETDEWEB)

    Ott, R. J. [Joint Department of Physics, Royal Marsden Hospital and Institute of Cancer Research, Surrey (United Kingdom); Stephenson, R. [Rutherford Appleton Laboratory, Oxfordshire (United Kingdom)

    2014-12-15

    Nuclear medicine imaging is generally based on the detection of X rays and γ rays emitted by radionuclides injected into a patient. In the previous chapter, the methods used to detect these photons were described, based most commonly on a scintillation counter although there are imaging devices that use either gas filled ionization detectors or semiconductors. Whatever device is used, nuclear medicine images are produced from a very limited number of photons, due mainly to the level of radioactivity that can be safely injected into a patient. Hence, nuclear medicine images are usually made from many orders of magnitude fewer photons than X ray computed tomography (CT) images, for example. However, as the information produced is essentially functional in nature compared to the anatomical detail of CT, the apparently poorer image quality is overcome by the nature of the information produced. The low levels of photons detected in nuclear medicine means that photon counting can be performed. Here each photon is detected and analysed individually, which is especially valuable, for example, in enabling scattered photons to be rejected. This is in contrast to X ray imaging where images are produced by integrating the flux entering the detectors. Photon counting, however, places a heavy burden on the electronics used for nuclear medicine imaging in terms of electronic noise and stability. This chapter will discuss how the signals produced in the primary photon detection process can be converted into pulses providing spatial, energy and timing information, and how this information is used to produce both qualitative and quantitative images.

  18. Automatic analysis of image quality control for Image Guided Radiation Therapy (IGRT) devices in external radiotherapy

    International Nuclear Information System (INIS)

    Torfeh, Tarraf

    2009-01-01

    On-board imagers mounted on a radiotherapy treatment machine are very effective devices that improve the geometric accuracy of radiation delivery. However, a precise and regular quality control program is required in order to achieve this objective. Our purpose consisted of developing software tools dedicated to an automatic image quality control of IGRT devices used in external radiotherapy: 2D-MV mode for measuring patient position during the treatment using high energy images, 2D-kV mode (low energy images) and 3D Cone Beam Computed Tomography (CBCT) MV or kV mode, used for patient positioning before treatment. Automated analysis of the Winston and Lutz test was also proposed. This test is used for the evaluation of the mechanical aspects of treatment machines on which additional constraints are carried out due to the on-board imagers additional weights. Finally, a technique of generating digital phantoms in order to assess the performance of the proposed software tools is described. Software tools dedicated to an automatic quality control of IGRT devices allow reducing by a factor of 100 the time spent by the medical physics team to analyze the results of controls while improving their accuracy by using objective and reproducible analysis and offering traceability through generating automatic monitoring reports and statistical studies. (author) [fr

  19. The stability of liquid-filled matrix ionization chamber electronic portal imaging devices for dosimetry purposes

    International Nuclear Information System (INIS)

    Louwe, R.J.W.; Tielenburg, R.; Ingen, K.M. van; Mijnheer, B.J.; Herk, M.B. van

    2004-01-01

    This study was performed to determine the stability of liquid-filled matrix ionization chamber (LiFi-type) electronic portal imaging devices (EPID) for dosimetric purposes. The short- and long-term stability of the response was investigated, as well as the importance of factors influencing the response (e.g., temperature fluctuations, radiation damage, and the performance of the electronic hardware). It was shown that testing the performance of the electronic hardware as well as the short-term stability of the imagers may reveal the cause of a poor long-term stability of the imager response. In addition, the short-term stability was measured to verify the validity of the fitted dose-response curve immediately after beam startup. The long-term stability of these imagers could be considerably improved by correcting for room temperature fluctuations and gradual changes in response due to radiation damage. As a result, the reproducibility was better than 1% (1 SD) over a period of two years. The results of this study were used to formulate recommendations for a quality control program for portal dosimetry. The effect of such a program was assessed by comparing the results of portal dosimetry and in vivo dosimetry using diodes during the treatment of 31 prostate patients. The improvement of the results for portal dosimetry was consistent with the deviations observed with the reproducibility tests in that particular period. After a correction for the variation in response of the imager, the average difference between the measured and prescribed dose during the treatment of prostate patients was -0.7%±1.5% (1 SD), and -0.6%±1.1% (1 SD) for EPID and diode in vivo dosimetry, respectively. It can be concluded that a high stability of the response can be achieved for this type of EPID by applying a rigorous quality control program

  20. Optimisation of the imaging and dosimetric characteristics of an electronic portal imaging device employing plastic scintillating fibres using Monte Carlo simulations.

    Science.gov (United States)

    Blake, S J; McNamara, A L; Vial, P; Holloway, L; Kuncic, Z

    2014-11-21

    A Monte Carlo model of a novel electronic portal imaging device (EPID) has been developed using Geant4 and its performance for imaging and dosimetry applications in radiotherapy has been characterised. The EPID geometry is based on a physical prototype under ongoing investigation and comprises an array of plastic scintillating fibres in place of the metal plate/phosphor screen in standard EPIDs. Geometrical and optical transport parameters were varied to investigate their impact on imaging and dosimetry performance. Detection efficiency was most sensitive to variations in fibre length, achieving a peak value of 36% at 50 mm using 400 keV x-rays for the lengths considered. Increases in efficiency for longer fibres were partially offset by reductions in sensitivity. Removing the extra-mural absorber surrounding individual fibres severely decreased the modulation transfer function (MTF), highlighting its importance in maximising spatial resolution. Field size response and relative dose profile simulations demonstrated a water-equivalent dose response and thus the prototype's suitability for dosimetry applications. Element-to-element mismatch between scintillating fibres and underlying photodiode pixels resulted in a reduced MTF for high spatial frequencies and quasi-periodic variations in dose profile response. This effect is eliminated when fibres are precisely matched to underlying pixels. Simulations strongly suggest that with further optimisation, this prototype EPID may be capable of simultaneous imaging and dosimetry in radiotherapy.

  1. Optimisation of the imaging and dosimetric characteristics of an electronic portal imaging device employing plastic scintillating fibres using Monte Carlo simulations

    Science.gov (United States)

    Blake, S. J.; McNamara, A. L.; Vial, P.; Holloway, L.; Kuncic, Z.

    2014-11-01

    A Monte Carlo model of a novel electronic portal imaging device (EPID) has been developed using Geant4 and its performance for imaging and dosimetry applications in radiotherapy has been characterised. The EPID geometry is based on a physical prototype under ongoing investigation and comprises an array of plastic scintillating fibres in place of the metal plate/phosphor screen in standard EPIDs. Geometrical and optical transport parameters were varied to investigate their impact on imaging and dosimetry performance. Detection efficiency was most sensitive to variations in fibre length, achieving a peak value of 36% at 50 mm using 400 keV x-rays for the lengths considered. Increases in efficiency for longer fibres were partially offset by reductions in sensitivity. Removing the extra-mural absorber surrounding individual fibres severely decreased the modulation transfer function (MTF), highlighting its importance in maximising spatial resolution. Field size response and relative dose profile simulations demonstrated a water-equivalent dose response and thus the prototype’s suitability for dosimetry applications. Element-to-element mismatch between scintillating fibres and underlying photodiode pixels resulted in a reduced MTF for high spatial frequencies and quasi-periodic variations in dose profile response. This effect is eliminated when fibres are precisely matched to underlying pixels. Simulations strongly suggest that with further optimisation, this prototype EPID may be capable of simultaneous imaging and dosimetry in radiotherapy.

  2. TU-AB-204-01: Device Approval Process

    International Nuclear Information System (INIS)

    Delfino, J.

    2016-01-01

    The responsibilities of the Food and Drug Administration (FDA) have increased since the inception of the Food and Drugs Act in 1906. Medical devices first came under comprehensive regulation with the passage of the 1938 Food, Drug, and Cosmetic Act. In 1971 FDA also took on the responsibility for consumer protection against unnecessary exposure to radiation-emitting devices for home and occupational use. However it was not until 1976, under the Medical Device Regulation Act, that the FDA was responsible for the safety and effectiveness of medical devices. This session will be presented by the Division of Radiological Health (DRH) and the Division of Imaging, Diagnostics, and Software Reliability (DIDSR) from the Center for Devices and Radiological Health (CDRH) at the FDA. The symposium will discuss on how we protect and promote public health with a focus on medical physics applications organized into four areas: pre-market device review, post-market surveillance, device compliance, current regulatory research efforts and partnerships with other organizations. The pre-market session will summarize the pathways FDA uses to regulate the investigational use and commercialization of diagnostic imaging and radiation therapy medical devices in the US, highlighting resources available to assist investigators and manufacturers. The post-market session will explain the post-market surveillance and compliance activities FDA performs to monitor the safety and effectiveness of devices on the market. The third session will describe research efforts that support the regulatory mission of the Agency. An overview of our regulatory research portfolio to advance our understanding of medical physics and imaging technologies and approaches to their evaluation will be discussed. Lastly, mechanisms that FDA uses to seek public input and promote collaborations with professional, government, and international organizations, such as AAPM, International Electrotechnical Commission (IEC

  3. TU-AB-204-01: Device Approval Process

    Energy Technology Data Exchange (ETDEWEB)

    Delfino, J. [Food & Drug Administration (United States)

    2016-06-15

    The responsibilities of the Food and Drug Administration (FDA) have increased since the inception of the Food and Drugs Act in 1906. Medical devices first came under comprehensive regulation with the passage of the 1938 Food, Drug, and Cosmetic Act. In 1971 FDA also took on the responsibility for consumer protection against unnecessary exposure to radiation-emitting devices for home and occupational use. However it was not until 1976, under the Medical Device Regulation Act, that the FDA was responsible for the safety and effectiveness of medical devices. This session will be presented by the Division of Radiological Health (DRH) and the Division of Imaging, Diagnostics, and Software Reliability (DIDSR) from the Center for Devices and Radiological Health (CDRH) at the FDA. The symposium will discuss on how we protect and promote public health with a focus on medical physics applications organized into four areas: pre-market device review, post-market surveillance, device compliance, current regulatory research efforts and partnerships with other organizations. The pre-market session will summarize the pathways FDA uses to regulate the investigational use and commercialization of diagnostic imaging and radiation therapy medical devices in the US, highlighting resources available to assist investigators and manufacturers. The post-market session will explain the post-market surveillance and compliance activities FDA performs to monitor the safety and effectiveness of devices on the market. The third session will describe research efforts that support the regulatory mission of the Agency. An overview of our regulatory research portfolio to advance our understanding of medical physics and imaging technologies and approaches to their evaluation will be discussed. Lastly, mechanisms that FDA uses to seek public input and promote collaborations with professional, government, and international organizations, such as AAPM, International Electrotechnical Commission (IEC

  4. Analysis of patient setup accuracy using electronic portal imaging device

    International Nuclear Information System (INIS)

    Onogi, Yuzo; Aoki, Yukimasa; Nakagawa, Keiichi

    1996-01-01

    Radiation therapy is performed in many fractions, and accurate patient setup is very important. This is more significant nowadays because treatment planning and radiation therapy are more precisely performed. Electronic portal imaging devices and automatic image comparison algorithms let us analyze setup deviations quantitatively. With such in mind we developed a simple image comparison algorithm. Using 2459 electronic verification images (335 ports, 123 treatment sites) generated during the past three years at our institute, we evaluated the results of the algorithm, and analyzed setup deviations according to the area irradiated, use of a fixing device (shell), and arm position. Calculated setup deviation was verified visually and their fitness was classified into good, fair, bad, and incomplete. The result was 40%, 14%, 22%, 24% respectively. Using calculated deviations classified as good (994 images), we analyzed setup deviations. Overall setup deviations described in 1 SD along axes x, y, z, was 1.9 mm, 2.5 mm, 1.7 mm respectively. We classified these deviations into systematic and random components, and found that random error was predominant in our institute. The setup deviations along axis y (cranio-caudal direction) showed larger distribution when treatment was performed with the shell. Deviations along y (cranio-caudal) and z (anterior-posterior) had larger distribution when treatment occurred with the patient's arm elevated. There was a significant time-trend error, whose deviations become greater with time. Within all evaluated ports, 30% showed a time-trend error. Using an electronic portal imaging device and automatic image comparison algorithm, we are able to analyze setup deviations more precisely and improve setup method based on objective criteria. (author)

  5. Assessment of image quality in x-ray radiography imaging using a small plasma focus device

    Science.gov (United States)

    Kanani, A.; Shirani, B.; Jabbari, I.; Mokhtari, J.

    2014-08-01

    This paper offers a comprehensive investigation of image quality parameters for a small plasma focus as a pulsed hard x-ray source for radiography applications. A set of images were captured from some metal objects and electronic circuits using a low energy plasma focus at different voltages of capacitor bank and different pressures of argon gas. The x-ray source focal spot of this device was obtained to be about 0.6 mm using the penumbra imaging method. The image quality was studied by several parameters such as image contrast, line spread function (LSF) and modulation transfer function (MTF). Results showed that the contrast changes by variations in gas pressure. The best contrast was obtained at a pressure of 0.5 mbar and 3.75 kJ stored energy. The results of x-ray dose from the device showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. The measurements of LSF and MTF parameters were carried out by means of a thin stainless steel wire 0.8 mm in diameter and the cut-off frequency was obtained to be about 1.5 cycles/mm.

  6. Flow characterization and patch clamp dose responses using jet microfluidics in a tubeless microfluidic device.

    Science.gov (United States)

    Resto, Pedro J; Bhat, Abhishek; Stava, Eric; Lor, Chong; Merriam, Elliot; Diaz-Rivera, Ruben E; Pearce, Robert; Blick, Robert; Williams, Justin C

    2017-11-01

    Surface tension passive pumping is a way to actuate flow without the need for pumps, tubing or valves by using the pressure inside small drop to move liquid via a microfluidic channel. These types of tubeless devices have typically been used in cell biology. Herein we present the use of tubeless devices as a fluid exchange platform for patch clamp electrophysiology. Inertia from high-speed droplets and jets is used to create flow and perform on-the-fly mixing of solutions. These are then flowed over GABA transfected HEK cells under patch in order to perform a dose response analysis. TIRF imaging and electrical recordings are used to study the fluid exchange properties of the microfluidic device, resulting in 0-90% fluid exchange times of hundreds of milliseconds. COMSOL is used to model flow and fluid exchange within the device. Patch-clamping experiments show the ability to use high-speed passive pumping and its derivatives for studying peak dose responses, but not for studying ion channel kinetics. Our system results in fluid exchange times slower than when using a standard 12-barrel application system and is not as stable as traditional methods, but it offers a new platform with added functionality. Surface tension passive pumping and tubeless devices can be used in a limited fashion for electrophysiology. Users may obtain peak dose responses but the system, in its current form, is not capable of fluid exchange fast enough to study the kinetics of most ion channels. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Low dose intranasal oxytocin delivered with Breath Powered device dampens amygdala response to emotional stimuli: A peripheral effect-controlled within- subjects randomized dose-response fMRI trial

    OpenAIRE

    Quintana, Daniel; Westlye, Lars Tjelta; Alnæs, Dag; Rustan, Øyvind; Kaufmann, Tobias; Smerud, Knut Terje; Mahmoud, Ramy; Djupesland, Per G.; Andreassen, Ole Andreas

    2016-01-01

    It is unclear if and how exogenous oxytocin (OT) reaches the brain to improve social behavior and cognition and what is the optimal dose for OT response. To better understand the delivery routes of intranasal OT administration to the brain and the dose-response, we compared amygdala response to facial stimuli by means of functional magnetic resonance imaging (fMRI) in four treatment conditions, including two different doses of intranasal OT using a novel Breath Powered device, intravenous (IV...

  8. Positron annihilation imaging device having movable collimator

    International Nuclear Information System (INIS)

    Thompson, C.J.

    1981-01-01

    This patent application relates to a positron annihilation imaging device comprising two circular arrays of detectors disposed in spaced apart parallel planes and circumferentially offset by half the detector spacing, axially movable annular outer collimator rings, generally disposed in a pair of opposite planes outside the associated planes of the detectors, each collimator being movable toward the opposite collimator. An inner collimator of annular configuration is disposed between the two rows of detectors and is formed in two rings which may be separated axially. The outer and inner collimators serve to enhance data readout and imaging. (author)

  9. A simple device for the stereoscopic display of 3D CT images

    International Nuclear Information System (INIS)

    Haveri, M.; Suramo, I.; Laehde, S.; Karhula, V.; Junila, J.

    1997-01-01

    We describe a simple device for creating true 3D views of image pairs obtained at 3D CT reconstruction. The device presents the images in a slightly different angle of view for the left and the right eyes. This true 3D viewing technique was applied experimentally in the evaluation of complex acetabular fractures. Experiments were also made to determine the optimal angle between the images for each eye. The angle varied between 1 and 7 for different observers and also depended on the display field of view used. (orig.)

  10. Noise characteristics of neutron images obtained by cooled CCD device

    International Nuclear Information System (INIS)

    Taniguchi, Ryoichi; Sasaki, Ryoya; Okuda, Shuichi; Okamoto, Ken-Ichi; Ogawa, Yoshihiro; Tsujimoto, Tadashi

    2009-01-01

    The noise characteristics of a cooled CCD device induced by neutron and gamma ray irradiation have been investigated. In the cooled CCD images, characteristic white spot noises (CCD noise) frequently appeared, which have a shape like a pixel in most cases and their brightness is extremely high compared with that of the image pattern. They could be divided into the two groups, fixed pattern noise (FPN) and random noise. The former always appeared in the same position in the image and the latter appeared at any position. In the background image, nearly all of the CCD noises were found to be the FPN, while many of them were the random noise during the irradiation. The random CCD noises increased with irradiation and decreased soon after the irradiation. In the case of large irradiation, a part of the CCD noise remained as the FPN. These facts suggest that the CCD noise is a phenomenon strongly relating to radiation damage of the CCD device.

  11. Application range of micro focus radiographic devices associated to image processors

    International Nuclear Information System (INIS)

    Cappabianca, C.; Ferriani, S.; Verre, F.

    1987-01-01

    X-ray devices having a focus area less than 100 μ are called micro focus X-ray equipment. Here the range of application and the characteristics of these devices including the possibility of employing the coupling with real time image enhancement computers are defined

  12. The optical-mechanical design of DMD modulation imaging device

    Science.gov (United States)

    Li, Tianting; Xu, Xiping; Qiao, Yang; Li, Lei; Pan, Yue

    2014-09-01

    In order to avoid the phenomenon of some image information were lost, which is due to the jamming signals, such as incident laser, make the pixels dot on CCD saturated. In this article a device of optical-mechanical structure was designed, which utilized the DMD (Digital Micro mirror Device) to modulate the image. The DMD reflection imaging optical system adopts the telecentric light path. However, because the design is not only required to guarantee a 66° angle between the optical axis of the relay optics and the DMD, but also to ensure that the optical axis of the projection system keeps parallel with the perpendicular bisector of the micro-mirror which is in the "flat" state, so the TIR prism is introduced,and making the relay optics and the DMD satisfy the optical institution's requirements. In this paper, a mechanical structure of the imaging optical system was designed and at the meanwhile the lens assembly has been well connected and fixed and fine-tuned by detailed structural design, which included the tilt decentered lens, wedge flanges, prisms. By optimizing the design, the issues of mutual restraint between the inverting optical system and the projecting system were well resolved, and prevented the blocking of the two systems. In addition, the structure size of the whole DMD reflection imaging optical system was minimized; it reduced the energy loss and ensured the image quality.

  13. Computer processing of image captured by the passive THz imaging device as an effective tool for its de-noising

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.; Kuchik, Igor E.; Zhang, Cun-lin; Deng, Chao; Zhao, Yuan-meng; Zhang, Xin

    2012-12-01

    As it is well-known, passive THz imaging devices have big potential for solution of the security problem. Nevertheless, one of the main problems, which take place on the way of using these devices, consists in the low image quality of developed passive THz camera. To change this situation, it is necessary to improve the engineering characteristics (resolution, sensitivity and so on) of the THz camera or to use computer processing of the image. In our opinion, the last issue is more preferable because it is more inexpensive. Below we illustrate possibility of suppression of the noise of the image captured by three THz passive camera developed in CNU (Beijing. China). After applying the computer processing of the image, its quality enhances many times. Achieved quality in many cases becomes enough for the detection of the object hidden under opaque clothes. We stress that the performance of developed computer code is enough high and does not restrict the performance of passive THz imaging device. The obtained results demonstrate the high efficiency of our approach for the detection of hidden objects and they are a very promising solution for the security problem. Nevertheless, developing the new spatial filter for treatment of the THz image remains a modern problem at present time.

  14. Positron annihilation imaging device using multiple offset rings of detectors

    International Nuclear Information System (INIS)

    Thompson, C.J.

    1981-01-01

    This patent application relates to a positron annihilation imaging device comprising two or more coaxial circular arrays of detectors (2,2'), with the detectors in one array angularly offset with respect to the detectors in the adjacent array to detect more than one tomographic image simultaneously through different cross-sections of a patient. (author)

  15. Dosimetric properties of an amorphous silicon electronic portal imaging device for verification of dynamic intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Greer, Peter B.; Popescu, Carmen C.

    2003-01-01

    Dosimetric properties of an amorphous silicon electronic portal imaging device (EPID) for verification of dynamic intensity modulated radiation therapy (IMRT) delivery were investigated. The EPID was utilized with continuous frame-averaging during the beam delivery. Properties studied included effect of buildup, dose linearity, field size response, sampling of rapid multileaf collimator (MLC) leaf speeds, response to dose-rate fluctuations, memory effect, and reproducibility. The dependence of response on EPID calibration and a dead time in image frame acquisition occurring every 64 frames were measured. EPID measurements were also compared to ion chamber and film for open and wedged static fields and IMRT fields. The EPID was linear with dose and dose rate, and response to MLC leaf speeds up to 2.5 cm s-1 was found to be linear. A field size dependent response of up to 5% relative to d max ion-chamber measurement was found. Reproducibility was within 0.8% (1 standard deviation) for an IMRT delivery recorded at intervals over a period of one month. The dead time in frame acquisition resulted in errors in the EPID that increased with leaf speed and were over 20% for a 1 cm leaf gap moving at 1.0 cm s-1. The EPID measurements were also found to depend on the input beam profile utilized for EPID flood-field calibration. The EPID shows promise as a device for verification of IMRT, the major limitation currently being due to dead-time in frame acquisition

  16. Mapping the Salinity Gradient in a Microfluidic Device with Schlieren Imaging

    Directory of Open Access Journals (Sweden)

    Chen-li Sun

    2015-05-01

    Full Text Available This work presents the use of the schlieren imaging to quantify the salinity gradients in a microfluidic device. By partially blocking the back focal plane of the objective lens, the schlieren microscope produces an image with patterns that correspond to spatial derivative of refractive index in the specimen. Since salinity variation leads to change in refractive index, the fluid mixing of an aqueous salt solution of a known concentration and water in a T-microchannel is used to establish the relation between salinity gradients and grayscale readouts. This relation is then employed to map the salinity gradients in the target microfluidic device from the grayscale readouts of the corresponding micro-schlieren image. For saline solution with salinity close to that of the seawater, the grayscale readouts vary linearly with the salinity gradient, and the regression line is independent of the flow condition and the salinity of the injected solution. It is shown that the schlieren technique is well suited to quantify the salinity gradients in microfluidic devices, for it provides a spatially resolved, non-invasive, full-field measurement.

  17. A service protocol for post-processing of medical images on the mobile device

    Science.gov (United States)

    He, Longjun; Ming, Xing; Xu, Lang; Liu, Qian

    2014-03-01

    With computing capability and display size growing, the mobile device has been used as a tool to help clinicians view patient information and medical images anywhere and anytime. It is uneasy and time-consuming for transferring medical images with large data size from picture archiving and communication system to mobile client, since the wireless network is unstable and limited by bandwidth. Besides, limited by computing capability, memory and power endurance, it is hard to provide a satisfactory quality of experience for radiologists to handle some complex post-processing of medical images on the mobile device, such as real-time direct interactive three-dimensional visualization. In this work, remote rendering technology is employed to implement the post-processing of medical images instead of local rendering, and a service protocol is developed to standardize the communication between the render server and mobile client. In order to make mobile devices with different platforms be able to access post-processing of medical images, the Extensible Markup Language is taken to describe this protocol, which contains four main parts: user authentication, medical image query/ retrieval, 2D post-processing (e.g. window leveling, pixel values obtained) and 3D post-processing (e.g. maximum intensity projection, multi-planar reconstruction, curved planar reformation and direct volume rendering). And then an instance is implemented to verify the protocol. This instance can support the mobile device access post-processing of medical image services on the render server via a client application or on the web page.

  18. Real-time two-dimensional imaging of potassium ion distribution using an ion semiconductor sensor with charged coupled device technology.

    Science.gov (United States)

    Hattori, Toshiaki; Masaki, Yoshitomo; Atsumi, Kazuya; Kato, Ryo; Sawada, Kazuaki

    2010-01-01

    Two-dimensional real-time observation of potassium ion distributions was achieved using an ion imaging device based on charge-coupled device (CCD) and metal-oxide semiconductor technologies, and an ion selective membrane. The CCD potassium ion image sensor was equipped with an array of 32 × 32 pixels (1024 pixels). It could record five frames per second with an area of 4.16 × 4.16 mm(2). Potassium ion images were produced instantly. The leaching of potassium ion from a 3.3 M KCl Ag/AgCl reference electrode was dynamically monitored in aqueous solution. The potassium ion selective membrane on the semiconductor consisted of plasticized poly(vinyl chloride) (PVC) with bis(benzo-15-crown-5). The addition of a polyhedral oligomeric silsesquioxane to the plasticized PVC membrane greatly improved adhesion of the membrane onto Si(3)N(4) of the semiconductor surface, and the potential response was stabilized. The potential response was linear from 10(-2) to 10(-5) M logarithmic concentration of potassium ion. The selectivity coefficients were K(K(+),Li(+))(pot) = 10(-2.85), K(K(+),Na(+))(pot) = 10(-2.30), K(K(+),Rb(+))(pot) =10(-1.16), and K(K(+),Cs(+))(pot) = 10(-2.05).

  19. TU-AB-204-02: Device Adverse Events and Compliance

    International Nuclear Information System (INIS)

    Gonzales, S.

    2016-01-01

    The responsibilities of the Food and Drug Administration (FDA) have increased since the inception of the Food and Drugs Act in 1906. Medical devices first came under comprehensive regulation with the passage of the 1938 Food, Drug, and Cosmetic Act. In 1971 FDA also took on the responsibility for consumer protection against unnecessary exposure to radiation-emitting devices for home and occupational use. However it was not until 1976, under the Medical Device Regulation Act, that the FDA was responsible for the safety and effectiveness of medical devices. This session will be presented by the Division of Radiological Health (DRH) and the Division of Imaging, Diagnostics, and Software Reliability (DIDSR) from the Center for Devices and Radiological Health (CDRH) at the FDA. The symposium will discuss on how we protect and promote public health with a focus on medical physics applications organized into four areas: pre-market device review, post-market surveillance, device compliance, current regulatory research efforts and partnerships with other organizations. The pre-market session will summarize the pathways FDA uses to regulate the investigational use and commercialization of diagnostic imaging and radiation therapy medical devices in the US, highlighting resources available to assist investigators and manufacturers. The post-market session will explain the post-market surveillance and compliance activities FDA performs to monitor the safety and effectiveness of devices on the market. The third session will describe research efforts that support the regulatory mission of the Agency. An overview of our regulatory research portfolio to advance our understanding of medical physics and imaging technologies and approaches to their evaluation will be discussed. Lastly, mechanisms that FDA uses to seek public input and promote collaborations with professional, government, and international organizations, such as AAPM, International Electrotechnical Commission (IEC

  20. TU-AB-204-02: Device Adverse Events and Compliance

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales, S. [Food & Drug Administration (United States)

    2016-06-15

    The responsibilities of the Food and Drug Administration (FDA) have increased since the inception of the Food and Drugs Act in 1906. Medical devices first came under comprehensive regulation with the passage of the 1938 Food, Drug, and Cosmetic Act. In 1971 FDA also took on the responsibility for consumer protection against unnecessary exposure to radiation-emitting devices for home and occupational use. However it was not until 1976, under the Medical Device Regulation Act, that the FDA was responsible for the safety and effectiveness of medical devices. This session will be presented by the Division of Radiological Health (DRH) and the Division of Imaging, Diagnostics, and Software Reliability (DIDSR) from the Center for Devices and Radiological Health (CDRH) at the FDA. The symposium will discuss on how we protect and promote public health with a focus on medical physics applications organized into four areas: pre-market device review, post-market surveillance, device compliance, current regulatory research efforts and partnerships with other organizations. The pre-market session will summarize the pathways FDA uses to regulate the investigational use and commercialization of diagnostic imaging and radiation therapy medical devices in the US, highlighting resources available to assist investigators and manufacturers. The post-market session will explain the post-market surveillance and compliance activities FDA performs to monitor the safety and effectiveness of devices on the market. The third session will describe research efforts that support the regulatory mission of the Agency. An overview of our regulatory research portfolio to advance our understanding of medical physics and imaging technologies and approaches to their evaluation will be discussed. Lastly, mechanisms that FDA uses to seek public input and promote collaborations with professional, government, and international organizations, such as AAPM, International Electrotechnical Commission (IEC

  1. 77 FR 32995 - Certain Electronic Imaging Devices Corrected: Notice of Receipt of Complaint; Solicitation of...

    Science.gov (United States)

    2012-06-04

    ... INTERNATIONAL TRADE COMMISSION [Docket No. 2898] Certain Electronic Imaging Devices Corrected.... International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has received a complaint entitled Certain Electronic Imaging Devices, DN 2898; the...

  2. 77 FR 31875 - Certain Electronic Imaging Devices; Notice of Receipt of Complaint; Solicitation of Comments...

    Science.gov (United States)

    2012-05-30

    ... INTERNATIONAL TRADE COMMISSION [Docket No. 2898] Certain Electronic Imaging Devices; Notice of... Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has received a complaint entitled Certain Electronic Imaging Devices, DN 2898; the Commission is...

  3. Evaluation of image quality for various electronic portal imaging devices in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Son, Soon Yong; Choi, Kwan Woo [Dept. of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Kim, Jung Min [Dept. of College of Health Science, Radiologic Science, Korea University, Seoul (Korea, Republic of); and others

    2015-12-15

    In megavoltage (MV) radiotherapy, delivering the dose to the target volume is important while protecting the surrounding normal tissue. The purpose of this study was to evaluate the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE) using an edge block in megavoltage X-ray imaging (MVI). We used an edge block, which consists of tungsten with dimensions of 19 (thickness) × 10 (length) × 1 (width) cm3 and measured the pre-sampling MTF at 6 MV energy. Various radiation therapy (RT) devices such as TrueBeamTM (Varian), BEAMVIEWPLUS (Siemens), iViewGT (Elekta) and Clinac®iX (Varian) were used. As for MTF results, TrueBeamTM(Varian) flattening filter free(FFF) showed the highest values of 0.46 mm-1and1.40mm-1for MTF 0.5 and 0.1. In NPS, iViewGT (Elekta) showed the lowest noise distribution. In DQE, iViewGT (Elekta) showed the best efficiency at a peak DQE and 1 mm-1DQE of 0.0026 and 0.00014, respectively. This study could be used not only for traditional QA imaging but also for quantitative MTF, NPS, and DQE measurement for development of an electronic portal imaging device (EPID)

  4. Assessment of image quality in x-ray radiography imaging using a small plasma focus device

    International Nuclear Information System (INIS)

    Kanani, A.; Shirani, B.; Jabbari, I.; Mokhtari, J.

    2014-01-01

    This paper offers a comprehensive investigation of image quality parameters for a small plasma focus as a pulsed hard x-ray source for radiography applications. A set of images were captured from some metal objects and electronic circuits using a low energy plasma focus at different voltages of capacitor bank and different pressures of argon gas. The x-ray source focal spot of this device was obtained to be about 0.6 mm using the penumbra imaging method. The image quality was studied by several parameters such as image contrast, line spread function (LSF) and modulation transfer function (MTF). Results showed that the contrast changes by variations in gas pressure. The best contrast was obtained at a pressure of 0.5 mbar and 3.75 kJ stored energy. The results of x-ray dose from the device showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. The measurements of LSF and MTF parameters were carried out by means of a thin stainless steel wire 0.8 mm in diameter and the cut-off frequency was obtained to be about 1.5 cycles/mm. - Highlights: • We investigated a small plasma focus as pulsed x-ray source for radiography applications. • The image quality was studied by several parameters such as image contrast, LSF and MTF. • The x-ray source focal spot was obtained to be ∼0.6 mm using the penumbra imaging method. • The x-ray dose measurement showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. • The profiles of LSF and MTF showed that the cut-off frequency is about 1.5 cycles/mm

  5. NOTE: A method for controlling image acquisition in electronic portal imaging devices

    Science.gov (United States)

    Glendinning, A. G.; Hunt, S. G.; Bonnett, D. E.

    2001-02-01

    Certain types of camera-based electronic portal imaging devices (EPIDs) which initiate image acquisition based on sensing a change in video level have been observed to trigger unreliably at the beginning of dynamic multileaf collimation sequences. A simple, novel means of controlling image acquisition with an Elekta linear accelerator (Elekta Oncology Systems, Crawley, UK) is proposed which is based on illumination of a photodetector (ORP-12, Silonex Inc., Plattsburgh, NY, USA) by the electron gun of the accelerator. By incorporating a simple trigger circuit it is possible to derive a beam on/off status signal which changes at least 100 ms before any dose is measured by the accelerator. The status signal does not return to the beam-off state until all dose has been delivered and is suitable for accelerator pulse repetition frequencies of 50-400 Hz. The status signal is thus a reliable means of indicating the initiation and termination of radiation exposure, and thus controlling image acquisition of such EPIDs for this application.

  6. Device for the track useful signal discrimination during the image scanning form bubble chambers

    International Nuclear Information System (INIS)

    Osipov, E.A.; Uvarov, V.A.

    1976-01-01

    A device for the image processing from the bubble chambers, developed to increase the reliability of the track useful signal discrimination at the image scanning from the background component is described. The device consists of a low-pass filter, repetition and memory circuit and subtraction circuit. Besides a delay line and extra channel consisting of a differentiating circuit in series with the selective shaping circuit are introduced into the device. The output signal of the selective shaping is the controlling signal of the repetition and memory circuit, at the output of which a signal corresponding the background component is formed. The functional diagram of the device operation is presented

  7. Improving image reviewing with a new system (Emoss, Memobank and Movicom devices)

    International Nuclear Information System (INIS)

    Wagner, G.; Otto, P.; Gourlez, P.; Taillade, B.

    1991-01-01

    The need is obvious for selecting the relevant images and/or items of information from among the overwhelming amount produced by C/S systems, mainly video cameras. Image reviewing in-field provides timeless while image reviewing at headquarters is used for confirming the validity of the conclusions drawn. There is also, in many cases, a need to improve the quality of the images. The Emoss and Memobank devices developed by Himatom could be the core of this new system, with its optimized digital storage which greatly improves image quality. These devices, which are compatible with existing systems such as MIVS and MUX, have the following advantages: comprehensive storage of scenes is comparable to the video tape recording; intelligent digital storage facilitates in-field reviewing; recoverable disc storage makes it possible to carry out the review at Headquarters; printing of the events helps reviewing. The Emoss and Memobank can be triggered by external information by other systems

  8. Ion beam induced charge and cathodoluminescence imaging of response uniformity of CVD diamond radiation detectors

    CERN Document Server

    Sellin, P J; Galbiati, A; Maghrabi, M; Townsend, P D

    2002-01-01

    The uniformity of response of CVD diamond radiation detectors produced from high quality diamond film, with crystallite dimensions of >100 mu m, has been studied using ion beam induced charge imaging. A micron-resolution scanning alpha particle beam was used to produce maps of pulse height response across the device. The detectors were fabricated with a single-sided coplanar electrode geometry to maximise their sensitivity to the surface region of the diamond film where the diamond crystallites are highly ordered. High resolution ion beam induced charge images of single crystallites were acquired that demonstrate variations in intra-crystallite charge transport and the termination of charge transport at the crystallite boundaries. Cathodoluminescence imaging of the same crystallites shows an inverse correlation between the density of radiative centres and regions of good charge transport.

  9. Development of an IMRT quality assurance program using an amorphous silicon electronic portal imaging device

    International Nuclear Information System (INIS)

    Hunt, P.; Oliver, L.; Mallik, A.

    2000-01-01

    Full text: Quality Assurance (QA) for an intensity modulated radiotherapy (IMRT) megavoltage beam is a complex task. The positional accuracy of the MLC; its radiation leakage; the overall distribution of the dose delivered as compared to the treatment plan and; the accuracy of the calculated monitor units to deliver this dose, are all important parameters to clinically monitor. We are presently assessing the Varian version 6 software package with CadPlan, Helios with IMRT and inverse planning, VARiS Vision and the linear accelerator DMLC controller. Whilst conventional QA tools such as ionisation chamber and film measurements are used, these methods are inconvenient for directly monitoring an IMRT patient treatment. Varian Medical Systems has developed an improved electronic portal imaging device (EPID) with an amorphous silicon (a-Si) detector array. The A-Si has a sensitive area of 40x30cm and an improved image resolution of 512x384 pixels. Images are recorded at approximately 7-10 frames per second for an exposure rate of 100-600 MU/minute. Although the A-Si was designed as an EPID for a static treatment field, this new device could be a valuable IMRT QA tool for a range of different tests. Measurements taken on the RNSH and Varian prototype A-Si EPI devices showed a linear dose response for 6-18MeV X-ray energy. In addition to the Varian IAS2 internal software handlers, we have developed some image data handling programs to view and analyse these images in more detail. The software is primarily used to view the images; measure the reading in a region of interest or profile; or merge, overlay, add or subtract images during the analysis. The small pixel resolution provides a reliable, highly accurate means of measuring beam size, leaf position, MLC radiation leakage or profile intensity curves with a positional accuracy of 0.8mm. The images produced by an IMRT exposure is clearly discernible and appears consistent with the result expected. Step wedge images

  10. Reading device of a radiation image contained in a radioluminescent screen and tomography device containing it

    International Nuclear Information System (INIS)

    Allemand, R.; Cuzin, M.; Parot, P.

    1984-01-01

    The present invention is aimed at improving the random access time to a stimulable radioluminescent screen point (and consequently the reading time of the screen image); it is noticeably useful for longitudinal tomography. The reading device contains a source emitting a stimulation radiation beam towards the stimulable radioluminescent screen, a control mean of the stimulation radiation beam and a deflection mean which allows the beam to scan the screen surface. The device is characterized by the use of a very fast acousto-optical type deflection mean [fr

  11. 3D Printing of Living Responsive Materials and Devices.

    Science.gov (United States)

    Liu, Xinyue; Yuk, Hyunwoo; Lin, Shaoting; Parada, German Alberto; Tang, Tzu-Chieh; Tham, Eléonore; de la Fuente-Nunez, Cesar; Lu, Timothy K; Zhao, Xuanhe

    2018-01-01

    3D printing has been intensively explored to fabricate customized structures of responsive materials including hydrogels, liquid-crystal elastomers, shape-memory polymers, and aqueous droplets. Herein, a new method and material system capable of 3D-printing hydrogel inks with programed bacterial cells as responsive components into large-scale (3 cm), high-resolution (30 μm) living materials, where the cells can communicate and process signals in a programmable manner, are reported. The design of 3D-printed living materials is guided by quantitative models that account for the responses of programed cells in printed microstructures of hydrogels. Novel living devices are further demonstrated, enabled by 3D printing of programed cells, including logic gates, spatiotemporally responsive patterning, and wearable devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Detection of fecal contamination on beef meat surfaces using handheld fluorescence imaging device (HFID)

    Science.gov (United States)

    Oh, Mirae; Lee, Hoonsoo; Cho, Hyunjeong; Moon, Sang-Ho; Kim, Eun-Kyung; Kim, Moon S.

    2016-05-01

    Current meat inspection in slaughter plants, for food safety and quality attributes including potential fecal contamination, is conducted through by visual examination human inspectors. A handheld fluorescence-based imaging device (HFID) was developed to be an assistive tool for human inspectors by highlighting contaminated food and food contact surfaces on a display monitor. It can be used under ambient lighting conditions in food processing plants. Critical components of the imaging device includes four 405-nm 10-W LEDs for fluorescence excitation, a charge-coupled device (CCD) camera, optical filter (670 nm used for this study), and Wi-Fi transmitter for broadcasting real-time video/images to monitoring devices such as smartphone and tablet. This study aimed to investigate the effectiveness of HFID in enhancing visual detection of fecal contamination on red meat, fat, and bone surfaces of beef under varying ambient luminous intensities (0, 10, 30, 50 and 70 foot-candles). Overall, diluted feces on fat, red meat and bone areas of beef surfaces were detectable in the 670-nm single-band fluorescence images when using the HFID under 0 to 50 foot-candle ambient lighting.

  13. Transient response of nonideal ion-selective microchannel-nanochannel devices

    Science.gov (United States)

    Leibowitz, Neta; Schiffbauer, Jarrod; Park, Sinwook; Yossifon, Gilad

    2018-04-01

    We report evidence of variation in ion selectivity of a fabricated microchannel-nanochannel device resulting in the appearance of a distinct local maximum in the overlimiting chronopotentiometric response. In this system consisting of shallow microchannels joined by a nanochannel, viscous shear at the microchannel walls suppresses the electro-osmotic instability and prevents any associated contribution to the nonmonotonic response. Thus, this response is primarily electrodiffusive. Numerical simulations indicate that concentration polarization develops not only within the microchannel but also within the nanochannel itself, with a local voltage maximum in the chronopotentiometric response correlated with interfacial depletion and having the classic i-2 Sands time dependence. Furthermore, the occurrence of the local maxima is correlated with the change in selectivity due to internal concentration polarization. Understanding the transient nonideal permselective response is essential for obtaining fundamental insight and for optimizing efficient operation of practical fabricated nanofluidic and membrane devices.

  14. Defect Characterization, Imaging, and Control in Wide-Bandgap Semiconductors and Devices

    Science.gov (United States)

    Brillson, L. J.; Foster, G. M.; Cox, J.; Ruane, W. T.; Jarjour, A. B.; Gao, H.; von Wenckstern, H.; Grundmann, M.; Wang, B.; Look, D. C.; Hyland, A.; Allen, M. W.

    2018-03-01

    Wide-bandgap semiconductors are now leading the way to new physical phenomena and device applications at nanoscale dimensions. The impact of defects on the electronic properties of these materials increases as their size decreases, motivating new techniques to characterize and begin to control these electronic states. Leading these advances have been the semiconductors ZnO, GaN, and related materials. This paper highlights the importance of native point defects in these semiconductors and describes how a complement of spatially localized surface science and spectroscopy techniques in three dimensions can characterize, image, and begin to control these electronic states at the nanoscale. A combination of characterization techniques including depth-resolved cathodoluminescence spectroscopy, surface photovoltage spectroscopy, and hyperspectral imaging can describe the nature and distribution of defects at interfaces at both bulk and nanoscale surfaces, their metal interfaces, and inside nanostructures themselves. These features as well as temperature and mechanical strain inside wide-bandgap device structures at the nanoscale can be measured even while these devices are operating. These advanced capabilities enable several new directions for describing defects at the nanoscale, showing how they contribute to device degradation, and guiding growth processes to control them.

  15. Transmission dosimetry with a liquid-filled electronic portal imaging device

    Energy Technology Data Exchange (ETDEWEB)

    Boellaard, R; Van Herk, M; Mijnheer, B J [Nederlands Kanker Inst. ` Antoni van Leeuwenhoekhuis` , Amsterdam (Netherlands)

    1995-12-01

    The aim of transmission dosimetry is to correlate transmission dose values with patient dose values. A liquid-filled electronic portal imaging device (EPID) has been developed. After determination of the dose response relationship, i.e. the relation between pixel value and dose rate, for clinical situations it was found that the EPID is applicable for two-dimensional dosimetry with an accuracy of about 1%. The aim of this study was to investigate transmission dose distributions at different phantom-detector distances to predict exit dose distributions from transmission dose images. An extensive set of transmission dose measurements below homogeneous phantoms were performed with the EPID. The influence of several parameters such as field size, phantom thickness, phantom-detector distance and phantom-source distance on the transmission dose and its distribution were investigated. The two-dimensional transmission dose images were separated into two components: a primary dose and a scattered dose distribution. It was found that the scattered dose is maximal at a phantom thickness of about 10 cm. The scattered dose distribution below a homogeneous phantom has a Gaussian shape. The width of the Gaussian is small at small phantom-detector distances and increases for larger phantom-detector distances. The dependence of the scattered dose distribution on the field size at various phantom-detector distances has been used to estimate the dose distribution at the exit site of the phantom. More work is underway to determine the exit dose distributions for clinical situations, including the presence of inhomogeneities.

  16. Transmission dosimetry with a liquid-filled electronic portal imaging device

    International Nuclear Information System (INIS)

    Boellaard, R.; Van Herk, M.; Mijnheer, B.J.

    1995-01-01

    The aim of transmission dosimetry is to correlate transmission dose values with patient dose values. A liquid-filled electronic portal imaging device (EPID) has been developed. After determination of the dose response relationship, i.e. the relation between pixel value and dose rate, for clinical situations it was found that the EPID is applicable for two-dimensional dosimetry with an accuracy of about 1%. The aim of this study was to investigate transmission dose distributions at different phantom-detector distances to predict exit dose distributions from transmission dose images. An extensive set of transmission dose measurements below homogeneous phantoms were performed with the EPID. The influence of several parameters such as field size, phantom thickness, phantom-detector distance and phantom-source distance on the transmission dose and its distribution were investigated. The two-dimensional transmission dose images were separated into two components: a primary dose and a scattered dose distribution. It was found that the scattered dose is maximal at a phantom thickness of about 10 cm. The scattered dose distribution below a homogeneous phantom has a Gaussian shape. The width of the Gaussian is small at small phantom-detector distances and increases for larger phantom-detector distances. The dependence of the scattered dose distribution on the field size at various phantom-detector distances has been used to estimate the dose distribution at the exit site of the phantom. More work is underway to determine the exit dose distributions for clinical situations, including the presence of inhomogeneities

  17. Thermal-Responsive Polymers for Enhancing Safety of Electrochemical Storage Devices.

    Science.gov (United States)

    Yang, Hui; Leow, Wan Ru; Chen, Xiaodong

    2018-03-01

    Thermal runway constitutes the most pressing safety issue in lithium-ion batteries and supercapacitors of large-scale and high-power density due to risks of fire or explosion. However, traditional strategies for averting thermal runaway do not enable the charging-discharging rate to change according to temperature or the original performance to resume when the device is cooled to room temperature. To efficiently control thermal runaway, thermal-responsive polymers provide a feasible and reversible strategy due to their ability to sense and subsequently act according to a predetermined sequence when triggered by heat. Herein, recent research progress on the use of thermal-responsive polymers to enhance the thermal safety of electrochemical storage devices is reviewed. First, a brief discussion is provided on the methods of preventing thermal runaway in electrochemical storage devices. Subsequently, a short review is provided on the different types of thermal-responsive polymers that can efficiently avoid thermal runaway, such as phase change polymers, polymers with sol-gel transitions, and polymers with positive temperature coefficients. The results represent the important development of thermal-responsive polymers toward the prevention of thermal runaway in next-generation smart electrochemical storage devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Vasovagal response secondary to permanent contraception device in pulmonary arterial hypertension

    Science.gov (United States)

    Cope, Jessica; Alnuaimat, Hassan

    2015-01-01

    Abstract Adequate contraception is an essential component of managing pulmonary hypertension in women of childbearing age. Intrauterine devices are a popular contraceptive choice for many women but are associated with a risk of vagal response upon placement in certain patients with pulmonary hypertension, which may not be well tolerated. More recently, newer permanent contraception devices have emerged in the market, such as the Essure. We describe the first case, to our knowledge, of vagal-associated response due to an Essure device placement. PMID:26697184

  19. Detection of Special Operations Forces Using Night Vision Devices

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.M.

    2001-10-22

    Night vision devices, such image intensifiers and infrared imagers, are readily available to a host of nations, organizations, and individuals through international commerce. Once the trademark of special operations units, these devices are widely advertised to ''turn night into day''. In truth, they cannot accomplish this formidable task, but they do offer impressive enhancement of vision in limited light scenarios through electronically generated images. Image intensifiers and infrared imagers are both electronic devices for enhancing vision in the dark. However, each is based upon a totally different physical phenomenon. Image intensifiers amplify the available light energy whereas infrared imagers detect the thermal energy radiated from all objects. Because of this, each device operates from energy which is present in a different portion of the electromagnetic spectrum. This leads to differences in the ability of each device to detect and/or identify objects. This report is a compilation of the available information on both state-of-the-art image intensifiers and infrared imagers. Image intensifiers developed in the United States, as well as some foreign made image intensifiers, are discussed. Image intensifiers are categorized according to their spectral response and sensitivity using the nomenclature of GEN I, GEN II, and GEN III. As the first generation of image intensifiers, GEN I, were large and of limited performance, this report will deal with only GEN II and GEN III equipment. Infrared imagers are generally categorized according to their spectral response, sensor materials, and related sensor operating temperature using the nomenclature Medium Wavelength Infrared (MWIR) Cooled and Long Wavelength Infrared (LWIR) Uncooled. MWIR Cooled refers to infrared imagers which operate in the 3 to 5 {micro}m wavelength electromagnetic spectral region and require either mechanical or thermoelectric coolers to keep the sensors operating at 77 K

  20. Traceable working standards with SI units of radiance for characterizing the measurement performance of investigational clinical NIRF imaging devices

    Science.gov (United States)

    Zhu, Banghe; Rasmussen, John C.; Litorja, Maritoni; Sevick-Muraca, Eva M.

    2017-03-01

    All medical devices for Food and Drug market approval require specifications of performance based upon International System of Units (SI) or units derived from SI for reasons of traceability. Recently, near-infrared fluorescence (NIRF) imaging devices of a variety of designs have emerged on the market and in investigational clinical studies. Yet the design of devices used in the clinical studies vary widely, suggesting variable device performance. Device performance depends upon optimal excitation of NIRF imaging agents, rejection of backscattered excitation and ambient light, and selective collection of fluorescence emanating from the fluorophore. There remains no traceable working standards with SI units of radiance to enable prediction that a given molecular imaging agent can be detected in humans by a given NIRF imaging device. Furthermore, as technologies evolve and as NIRF imaging device components change, there remains no standardized means to track device improvements over time and establish clinical performance without involving clinical trials, often costly. In this study, we deployed a methodology to calibrate luminescent radiance of a stable, solid phantom in SI units of mW/cm2/sr for characterizing the measurement performance of ICCD and IsCMOS camera based NIRF imaging devices, such as signal-to-noise ratio (SNR) and contrast. The methodology allowed determination of superior SNR of the ICCD over the IsCMOS system; comparable contrast of ICCD and IsCMOS depending upon binning strategies.

  1. Assessment of dosimetrical performance in 11 Varian a-Si500 electronic portal imaging devices

    International Nuclear Information System (INIS)

    Kavuma, Awusi; Glegg, Martin; Currie, Garry; Elliott, Alex

    2008-01-01

    Dosimetrical characteristics of 11 Varian a-Si-500 electronic portal imaging devices (EPIDs) in clinical use for periods ranging between 10 and 86 months were investigated for consistency of performance and portal dosimetry implications. Properties studied include short-term reproducibility, signal linearity with monitor units, response to reference beam, signal uniformity across the detector panel, signal dependence on field size, dose-rate influence, memory effects and image profiles as a function of monitor units. The EPID measurements were also compared with those of the ionization chambers' to ensure stability of the linear accelerators. Depending on their clinical installation date, the EPIDs were interfaced with one of the two different acquisition control software packages, IAS2/IDU-II or IAS3/IDU-20. Both the EPID age and image acquisition system influenced the dosimetric characteristics with the newer version (IAS3 with IDU-20) giving better data reproducibility and linearity fit than the older version (IAS2 with IDU-II). The relative signal response (uniformity) after 50 MU was better than 95% of the central value and independent of detector. Sensitivity for all EPIDs reduced continuously with increasing dose rates for the newer image acquisition software. In the dose-rate range 100-600 MU min -1 , the maximum variation in sensitivity ranged between 1 and 1.8% for different EPIDs. For memory effects, the increase in the measured signal at the centre of the irradiated field for successive images was within 1.8% and 1.0% for the older and newer acquisition systems, respectively. Image profiles acquired at a lower MU in the radial plane (gun-target) had gradients in measured pixel values of up to 25% for the older system. Detectors with software/hardware versions IAS3/IDU-20 have a high degree of accuracy and are more suitable for routine quantitative IMRT dosimetrical verification.

  2. Microwave impedance imaging on semiconductor memory devices

    Science.gov (United States)

    Kundhikanjana, Worasom; Lai, Keji; Yang, Yongliang; Kelly, Michael; Shen, Zhi-Xun

    2011-03-01

    Microwave impedance microscopy (MIM) maps out the real and imaginary components of the tip-sample impedance, from which the local conductivity and dielectric constant distribution can be derived. The stray field contribution is minimized in our shielded cantilever design, enabling quantitative analysis of nano-materials and device structures. We demonstrate here that the MIM can spatially resolve the conductivity variation in a dynamic random access memory (DRAM) sample. With DC or low-frequency AC bias applied to the tip, contrast between n-doped and p-doped regions in the dC/dV images is observed, and p-n junctions are highlighted in the dR/dV images. The results can be directly compared with data taken by scanning capacitance microscope (SCM), which uses unshielded cantilevers and resonant electronics, and the MIM reveals more information of the local dopant concentration than SCM.

  3. Device for congruent X-ray images of teeth

    International Nuclear Information System (INIS)

    Wegner, H.; Zeumer, H.

    1987-01-01

    This invention has to do with a device for congruent X-ray images of teeth by means of the long-tube parallel technique and the long-tube semi-angle technique. The aim is to have no disturbing lever forces in order to avoid mechanical tensions between patient and X-ray tube assembly and to achieve a true projection of teeth and jaw-bone part also under unfavourable anatomical conditions

  4. X ray sensitive area detection device

    Science.gov (United States)

    Carter, Daniel C. (Inventor); Witherow, William K. (Inventor); Pusey, Marc L. (Inventor); Yost, Vaughn H. (Inventor)

    1990-01-01

    A radiation sensitive area detection device is disclosed which comprises a phosphor-containing film capable of receiving and storing an image formed by a pattern of incoming x rays, UV, or other radiation falling on the film. The device is capable of fluorescing in response to stimulation by a light source in a manner directly proportional to the stored radiation pattern. The device includes: (1) a light source capable of projecting light or other appropriate electromagnetic wave on the film so as to cause it to fluoresce; (2) a means to focus the fluoresced light coming from the phosphor-containing film after light stimulation; and (3) at least one charged coupled detector or other detecting element capable of receiving and digitizing the pattern of fluoresced light coming from the phosphor-containing film. The device will be able to generate superior x ray images of high resolution from a crystal or other sample and will be particularly advantageous in that instantaneous near-real-time images of rapidly deteriorating samples can be obtained. Furthermore, the device can be made compact and sturdy, thus capable of carrying out x ray or other radiation imaging under a variety of conditions, including those experienced in space.

  5. 77 FR 38829 - Certain Electronic Imaging Devices; Institution of Investigation

    Science.gov (United States)

    2012-06-29

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-850] Certain Electronic Imaging Devices; Institution of Investigation AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that a complaint was filed with the U.S. International Trade Commission on May 23, 2012...

  6. Magnetic resonance imaging-compatible tactile sensing device based on a piezoelectric array.

    Science.gov (United States)

    Hamed, Abbi; Masamune, Ken; Tse, Zion Tsz Ho; Lamperth, Michael; Dohi, Takeyoshi

    2012-07-01

    Minimally invasive surgery is a widely used medical technique, one of the drawbacks of which is the loss of direct sense of touch during the operation. Palpation is the use of fingertips to explore and make fast assessments of tissue morphology. Although technologies are developed to equip minimally invasive surgery tools with haptic feedback capabilities, the majority focus on tissue stiffness profiling and tool-tissue interaction force measurement. For greatly increased diagnostic capability, a magnetic resonance imaging-compatible tactile sensor design is proposed, which allows minimally invasive surgery to be performed under image guidance, combining the strong capability of magnetic resonance imaging soft tissue and intuitive palpation. The sensing unit is based on a piezoelectric sensor methodology, which conforms to the stringent mechanical and electrical design requirements imposed by the magnetic resonance environment The sensor mechanical design and the device integration to a 0.2 Tesla open magnetic resonance imaging scanner are described, together with the device's magnetic resonance compatibility testing. Its design limitations and potential future improvements are also discussed. A tactile sensing unit based on a piezoelectric sensor principle is proposed, which is designed for magnetic resonance imaging guided interventions.

  7. TU-AB-204-00: CDRH/FDA Regulatory Processes and Device Science Activities

    International Nuclear Information System (INIS)

    2016-01-01

    The responsibilities of the Food and Drug Administration (FDA) have increased since the inception of the Food and Drugs Act in 1906. Medical devices first came under comprehensive regulation with the passage of the 1938 Food, Drug, and Cosmetic Act. In 1971 FDA also took on the responsibility for consumer protection against unnecessary exposure to radiation-emitting devices for home and occupational use. However it was not until 1976, under the Medical Device Regulation Act, that the FDA was responsible for the safety and effectiveness of medical devices. This session will be presented by the Division of Radiological Health (DRH) and the Division of Imaging, Diagnostics, and Software Reliability (DIDSR) from the Center for Devices and Radiological Health (CDRH) at the FDA. The symposium will discuss on how we protect and promote public health with a focus on medical physics applications organized into four areas: pre-market device review, post-market surveillance, device compliance, current regulatory research efforts and partnerships with other organizations. The pre-market session will summarize the pathways FDA uses to regulate the investigational use and commercialization of diagnostic imaging and radiation therapy medical devices in the US, highlighting resources available to assist investigators and manufacturers. The post-market session will explain the post-market surveillance and compliance activities FDA performs to monitor the safety and effectiveness of devices on the market. The third session will describe research efforts that support the regulatory mission of the Agency. An overview of our regulatory research portfolio to advance our understanding of medical physics and imaging technologies and approaches to their evaluation will be discussed. Lastly, mechanisms that FDA uses to seek public input and promote collaborations with professional, government, and international organizations, such as AAPM, International Electrotechnical Commission (IEC

  8. TU-AB-204-00: CDRH/FDA Regulatory Processes and Device Science Activities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-06-15

    The responsibilities of the Food and Drug Administration (FDA) have increased since the inception of the Food and Drugs Act in 1906. Medical devices first came under comprehensive regulation with the passage of the 1938 Food, Drug, and Cosmetic Act. In 1971 FDA also took on the responsibility for consumer protection against unnecessary exposure to radiation-emitting devices for home and occupational use. However it was not until 1976, under the Medical Device Regulation Act, that the FDA was responsible for the safety and effectiveness of medical devices. This session will be presented by the Division of Radiological Health (DRH) and the Division of Imaging, Diagnostics, and Software Reliability (DIDSR) from the Center for Devices and Radiological Health (CDRH) at the FDA. The symposium will discuss on how we protect and promote public health with a focus on medical physics applications organized into four areas: pre-market device review, post-market surveillance, device compliance, current regulatory research efforts and partnerships with other organizations. The pre-market session will summarize the pathways FDA uses to regulate the investigational use and commercialization of diagnostic imaging and radiation therapy medical devices in the US, highlighting resources available to assist investigators and manufacturers. The post-market session will explain the post-market surveillance and compliance activities FDA performs to monitor the safety and effectiveness of devices on the market. The third session will describe research efforts that support the regulatory mission of the Agency. An overview of our regulatory research portfolio to advance our understanding of medical physics and imaging technologies and approaches to their evaluation will be discussed. Lastly, mechanisms that FDA uses to seek public input and promote collaborations with professional, government, and international organizations, such as AAPM, International Electrotechnical Commission (IEC

  9. WE-E-18A-08: Towards a Next-Generation Electronic Portal Device for Simultaneous Imaging and Dose Verification in Radiotherapy

    International Nuclear Information System (INIS)

    Blake, S; Vial, P; Holloway, L; Kuncic, Z

    2014-01-01

    Purpose: This work forms part of an ongoing study to develop a next-generation electronic portal imaging device (EPID) for simultaneous imaging and dose verification in radiotherapy. Monte Carlo (MC) simulations were used to characterize the imaging performance of a novel EPID that has previously been demonstrated to exhibit a water-equivalent response. The EPID ' s response was quantified in several configurations and model parameters were empirically validated against experimental measurements. Methods: A MC model of a novel a-Si EPID incorporating an array of plastic scintillating fibers was developed. Square BCF-99-06A scintillator fibers with PMMA cladding (Saint-Gobain Crystals) were modelled in a matrix with total area measuring 150×150 mm 2 . The standard electromagnetic and optical physics Geant4 classes were used to simulate radiation transport from an angled slit source (6 MV energy spectrum) through the EPID and optical photons reaching the photodiodes were scored. The prototype's modulation transfer function (MTF) was simulated and validated against experimental measurements. Several optical transport parameters, fiber lengths and thicknesses of an air gap between the scintillator and photodiodes were investigated to quantify their effects on the prototype's detection efficiency, sensitivity and MTF. Results: Simulated EPID response was more sensitive to variations in geometry than in the optical parameters studied. The MTF was particularly sensitive to the introduction of a 0.5–1.0 mm air gap between the scintillator and photodiodes, which lowered the MTF relative to that simulated without the gap. As expected, increasing the fiber length increased the detector efficiency and sensitivity while decreasing the MTF. Conclusion: A model of a novel water-equivalent EPID has been developed and benchmarked against measurements using a physical prototype. We have demonstrated the feasibility of this new device and are continuing to optimize

  10. Are Portable Stereophotogrammetric Devices Reliable in Facial Imaging? A Validation Study of VECTRA H1 Device.

    Science.gov (United States)

    Gibelli, Daniele; Pucciarelli, Valentina; Cappella, Annalisa; Dolci, Claudia; Sforza, Chiarella

    2018-01-31

    Modern 3-dimensional (3D) image acquisition systems represent a crucial technologic development in facial anatomy because of their accuracy and precision. The recently introduced portable devices can improve facial databases by increasing the number of applications. In the present study, the VECTRA H1 portable stereophotogrammetric device was validated to verify its applicability to 3D facial analysis. Fifty volunteers underwent 4 facial scans using portable VECTRA H1 and static VECTRA M3 devices (2 for each instrument). Repeatability of linear, angular, surface area, and volume measurements was verified within the device and between devices using the Bland-Altman test and the calculation of absolute and relative technical errors of measurement (TEM and rTEM, respectively). In addition, the 2 scans obtained by the same device and the 2 scans obtained by different devices were registered and superimposed to calculate the root mean square (RMS; point-to-point) distance between the 2 surfaces. Most linear, angular, and surface area measurements had high repeatability in M3 versus M3, H1 versus H1, and M3 versus H1 comparisons (range, 82.2 to 98.7%; TEM range, 0.3 to 2.0 mm, 0.4° to 1.8°; rTEM range, 0.2 to 3.1%). In contrast, volumes and RMS distances showed evident differences in M3 versus M3 and H1 versus H1 comparisons and reached the maximum when scans from the 2 different devices were compared. The portable VECTRA H1 device proved reliable for assessing linear measurements, angles, and surface areas; conversely, the influence of involuntary facial movements on volumes and RMS distances was more important compared with the static device. Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Evaluation of charge coupled devices as alpha particle detectors

    International Nuclear Information System (INIS)

    Pace, R.; Haskard, M.; Watts, S.; Holmes-Siedle, A.; Solanky, M.

    1996-01-01

    The ability of the Charge Coupled Device (CCD) to provide spectroscopic and flux information for highly ionising radiation has been investigated. CCDs and related imaging chips are becoming increasingly affordable. In addition advances in technology are producing smaller and better devices. Since imaging chips are based on some variation of the pn-diode structure it is expected and known that they are sensitive to ionising radiation as well as light. Indeed specially designed CCDs are able to be used to image X-rays. This paper reports on the response of CCDs to alpha particles. (author)

  12. The Biological Responses to Magnesium-Based Biodegradable Medical Devices

    Directory of Open Access Journals (Sweden)

    Lumei Liu

    2017-11-01

    Full Text Available The biocompatibility of Magnesium-based materials (MBMs is critical to the safety of biodegradable medical devices. As a promising metallic biomaterial for medical devices, the issue of greatest concern is devices’ safety as degrading products are possibly interacting with local tissue during complete degradation. The aim of this review is to summarize the biological responses to MBMs at the cellular/molecular level, including cell adhesion, transportation signaling, immune response, and tissue growth during the complex degradation process. We review the influence of MBMs on gene/protein biosynthesis and expression at the site of implantation, as well as throughout the body. This paper provides a systematic review of the cellular/molecular behavior of local tissue on the response to Mg degradation, which may facilitate a better prediction of long-term degradation and the safe use of magnesium-based implants through metal innovation.

  13. An MR-compatible device for delivering smoked marijuana during functional imaging.

    Science.gov (United States)

    Frederick, Blaise deB; Lindsey, Kimberly P; Nickerson, Lisa D; Ryan, Elizabeth T; Lukas, Scott E

    2007-05-01

    Smoking is the preferred method of administration for two of the most frequently abused drugs, marijuana and nicotine. The high temporal and spatial resolution of functional magnetic resonance imaging (fMRI) make it a natural choice for studying the neurobiological effects of smoked drugs if the challenges of smoking in a magnetic resonance (MR) scanner can be overcome. We report on a design for an MR-compatible smoking device that can be used for smoking marijuana (or tobacco) during fMRI examinations. Nine volunteers smoked marijuana cigarettes (3.51% Delta9-THC) on two occasions: with and without the device. The device allowed subjects to smoke while they lay in the scanner, while containing all smoke and odors. Plasma Delta9-THC, subjective reports of intoxication, and heart rate increases are reported, and were all similar in individuals smoking marijuana either with or without the device. The use of this device will help advance research studies on smoked drugs including marijuana, tobacco and crack cocaine.

  14. Method using in vivo quantitative spectroscopy to guide design and optimization of low-cost, compact clinical imaging devices: emulation and evaluation of multispectral imaging systems

    Science.gov (United States)

    Saager, Rolf B.; Baldado, Melissa L.; Rowland, Rebecca A.; Kelly, Kristen M.; Durkin, Anthony J.

    2018-04-01

    With recent proliferation in compact and/or low-cost clinical multispectral imaging approaches and commercially available components, questions remain whether they adequately capture the requisite spectral content of their applications. We present a method to emulate the spectral range and resolution of a variety of multispectral imagers, based on in-vivo data acquired from spatial frequency domain spectroscopy (SFDS). This approach simulates spectral responses over 400 to 1100 nm. Comparing emulated data with full SFDS spectra of in-vivo tissue affords the opportunity to evaluate whether the sparse spectral content of these imagers can (1) account for all sources of optical contrast present (completeness) and (2) robustly separate and quantify sources of optical contrast (crosstalk). We validate the approach over a range of tissue-simulating phantoms, comparing the SFDS-based emulated spectra against measurements from an independently characterized multispectral imager. Emulated results match the imager across all phantoms (<3 % absorption, <1 % reduced scattering). In-vivo test cases (burn wounds and photoaging) illustrate how SFDS can be used to evaluate different multispectral imagers. This approach provides an in-vivo measurement method to evaluate the performance of multispectral imagers specific to their targeted clinical applications and can assist in the design and optimization of new spectral imaging devices.

  15. A Quick-responsive DNA Nanotechnology Device for Bio-molecular Homeostasis Regulation.

    Science.gov (United States)

    Wu, Songlin; Wang, Pei; Xiao, Chen; Li, Zheng; Yang, Bing; Fu, Jieyang; Chen, Jing; Wan, Neng; Ma, Cong; Li, Maoteng; Yang, Xiangliang; Zhan, Yi

    2016-08-10

    Physiological processes such as metabolism, cell apoptosis and immune responses, must be strictly regulated to maintain their homeostasis and achieve their normal physiological functions. The speed with which bio-molecular homeostatic regulation occurs directly determines the ability of an organism to adapt to conditional changes. To produce a quick-responsive regulatory system that can be easily utilized for various types of homeostasis, a device called nano-fingers that facilitates the regulation of physiological processes was constructed using DNA origami nanotechnology. This nano-fingers device functioned in linked open and closed phases using two types of DNA tweezers, which were covalently coupled with aptamers that captured specific molecules when the tweezer arms were sufficiently close. Via this specific interaction mechanism, certain physiological processes could be simultaneously regulated from two directions by capturing one biofactor and releasing the other to enhance the regulatory capacity of the device. To validate the universal application of this device, regulation of the homeostasis of the blood coagulant thrombin was attempted using the nano-fingers device. It was successfully demonstrated that this nano-fingers device achieved coagulation buffering upon the input of fuel DNA. This nano-device could also be utilized to regulate the homeostasis of other types of bio-molecules.

  16. Monitoring of biofilm formation on different material surfaces of medical devices using hyperspectral imaging method

    Science.gov (United States)

    Kim, Do-Hyun; Kim, Moon S.; Hwang, Jeeseong

    2012-03-01

    Contamination of the inner surface of indwelling (implanted) medical devices by microbial biofilm is a serious problem. Some microbial bacteria such as Escherichia coli form biofilms that lead to potentially lifethreatening infections. Other types of medical devices such as bronchoscopes and duodenoscopes account for the highest number of reported endoscopic infections where microbial biofilm is one of the major causes for these infections. We applied a hyperspectral imaging method to detect biofilm contamination on the surface of several common materials used for medical devices. Such materials include stainless steel, titanium, and stainless-steeltitanium alloy. Potential uses of hyperspectral imaging technique to monitor biofilm attachment to different material surfaces are discussed.

  17. Image recognition and consistency of response

    Science.gov (United States)

    Haygood, Tamara M.; Ryan, John; Liu, Qing Mary A.; Bassett, Roland; Brennan, Patrick C.

    2012-02-01

    Purpose: To investigate the connection between conscious recognition of an image previously encountered in an experimental setting and consistency of response to the experimental question. Materials and Methods: Twenty-four radiologists viewed 40 frontal chest radiographs and gave their opinion as to the position of a central venous catheter. One-to-three days later they again viewed 40 frontal chest radiographs and again gave their opinion as to the position of the central venous catheter. Half of the radiographs in the second set were repeated images from the first set and half were new. The radiologists were asked of each image whether it had been included in the first set. For this study, we are evaluating only the 20 repeated images. We used the Kruskal-Wallis test and Fisher's exact test to determine the relationship between conscious recognition of a previously interpreted image and consistency in interpretation of the image. Results. There was no significant correlation between recognition of the image and consistency in response regarding the position of the central venous catheter. In fact, there was a trend in the opposite direction, with radiologists being slightly more likely to give a consistent response with respect to images they did not recognize than with respect to those they did recognize. Conclusion: Radiologists' recognition of previously-encountered images in an observer-performance study does not noticeably color their interpretation on the second encounter.

  18. Tiny Devices Project Sharp, Colorful Images

    Science.gov (United States)

    2009-01-01

    Displaytech Inc., based in Longmont, Colorado and recently acquired by Micron Technology Inc. of Boise, Idaho, first received a Small Business Innovation Research contract in 1993 from Johnson Space Center to develop tiny, electronic, color displays, called microdisplays. Displaytech has since sold over 20 million microdisplays and was ranked one of the fastest growing technology companies by Deloitte and Touche in 2005. Customers currently incorporate the microdisplays in tiny pico-projectors, which weigh only a few ounces and attach to media players, cell phones, and other devices. The projectors can convert a digital image from the typical postage stamp size into a bright, clear, four-foot projection. The company believes sales of this type of pico-projector may exceed $1.1 billion within 5 years.

  19. Characterization of a direct detection device imaging camera for transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Milazzo, Anna-Clare, E-mail: amilazzo@ncmir.ucsd.edu [University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093 (United States); Moldovan, Grigore [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Lanman, Jason [Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037 (United States); Jin, Liang; Bouwer, James C. [University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093 (United States); Klienfelder, Stuart [University of California at Irvine, Irvine, CA 92697 (United States); Peltier, Steven T.; Ellisman, Mark H. [University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093 (United States); Kirkland, Angus I. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Xuong, Nguyen-Huu [University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093 (United States)

    2010-06-15

    The complete characterization of a novel direct detection device (DDD) camera for transmission electron microscopy is reported, for the first time at primary electron energies of 120 and 200 keV. Unlike a standard charge coupled device (CCD) camera, this device does not require a scintillator. The DDD transfers signal up to 65 lines/mm providing the basis for a high-performance platform for a new generation of wide field-of-view high-resolution cameras. An image of a thin section of virus particles is presented to illustrate the substantially improved performance of this sensor over current indirectly coupled CCD cameras.

  20. Characterization of a direct detection device imaging camera for transmission electron microscopy

    International Nuclear Information System (INIS)

    Milazzo, Anna-Clare; Moldovan, Grigore; Lanman, Jason; Jin, Liang; Bouwer, James C.; Klienfelder, Stuart; Peltier, Steven T.; Ellisman, Mark H.; Kirkland, Angus I.; Xuong, Nguyen-Huu

    2010-01-01

    The complete characterization of a novel direct detection device (DDD) camera for transmission electron microscopy is reported, for the first time at primary electron energies of 120 and 200 keV. Unlike a standard charge coupled device (CCD) camera, this device does not require a scintillator. The DDD transfers signal up to 65 lines/mm providing the basis for a high-performance platform for a new generation of wide field-of-view high-resolution cameras. An image of a thin section of virus particles is presented to illustrate the substantially improved performance of this sensor over current indirectly coupled CCD cameras.

  1. Verification of multileaf collimator leaf positions using an electronic portal imaging device

    International Nuclear Information System (INIS)

    Samant, Sanjiv S.; Zheng Wei; Parra, Nestor Andres; Chandler, Jason; Gopal, Arun; Wu Jian; Jain Jinesh; Zhu Yunping; Sontag, Marc

    2002-01-01

    An automated method is presented for determining individual leaf positions of the Siemens dual focus multileaf collimator (MLC) using the Siemens BEAMVIEW(PLUS) electronic portal imaging device (EPID). Leaf positions are computed with an error of 0.6 mm at one standard deviation (σ) using separate computations of pixel dimensions, image distortion, and radiation center. The pixel dimensions are calculated by superimposing the film image of a graticule with the corresponding EPID image. A spatial correction is used to compensate for the optical distortions of the EPID, reducing the mean distortion from 3.5 pixels (uncorrected) per localized x-ray marker to 2 pixels (1 mm) for a rigid rotation and 1 pixel for a third degree polynomial warp. A correction for a nonuniform dosimetric response across the field of view of the EPID images is not necessary due to the sharp intensity gradients across leaf edges. The radiation center, calculated from the average of the geometric centers of a square field at 0 deg. and 180 deg. collimator angles, is independent of graticule placement error. Its measured location on the EPID image was stable to within 1 pixel based on 3 weeks of repeated extensions/retractions of the EPID. The MLC leaf positions determined from the EPID images agreed to within a pixel of the corresponding values measured using film and ionization chamber. Several edge detection algorithms were tested: contour, Sobel, Roberts, Prewitt, Laplace, morphological, and Canny. These agreed with each other to within ≤1.2 pixels for the in-air EPID images. Using a test pattern, individual MLC leaves were found to be typically within 1 mm of the corresponding record-and-verify values, with a maximum difference of 1.8 mm, and standard deviations of <0.3 mm in the daily reproducibility. This method presents a fast, automatic, and accurate alternative to using film or a light field for the verification and calibration of the MLC

  2. Response of asymmetric carbon nanotube network devices to sub-terahertz and terahertz radiation

    International Nuclear Information System (INIS)

    Gayduchenko, I.; Kardakova, A.; Voronov, B.; Finkel, M.; Fedorov, G.; Jiménez, D.; Morozov, S.; Presniakov, M.; Goltsman, G.

    2015-01-01

    Demand for efficient terahertz radiation detectors resulted in intensive study of the asymmetric carbon nanostructures as a possible solution for that problem. It was maintained that photothermoelectric effect under certain conditions results in strong response of such devices to terahertz radiation even at room temperature. In this work, we investigate different mechanisms underlying the response of asymmetric carbon nanotube (CNT) based devices to sub-terahertz and terahertz radiation. Our structures are formed with CNT networks instead of individual CNTs so that effects probed are more generic and not caused by peculiarities of an individual nanoscale object. We conclude that the DC voltage response observed in our structures is not only thermal in origin. So called diode-type response caused by asymmetry of the device IV characteristic turns out to be dominant at room temperature. Quantitative analysis provides further routes for the optimization of the device configuration, which may result in appearance of novel terahertz radiation detectors

  3. Quality assurance for electronic portal imaging devices

    International Nuclear Information System (INIS)

    Shalev, S.; Rajapakshe, R.; Gluhchev, G.; Luchka, K.

    1997-01-01

    Electronic portal imaging devices (EPIDS) are assuming an ever-increasing role in the verification of radiation treatment accuracy. They are used both in a passive capacity, for the determination of field displacement distributions (''setup errors''), and also in an active role whereby the patient setup is corrected on the basis of electronic portal images. In spite of their potential impact on the precision of patient treatment, there are few quality assurance procedures available, and most of the EPIDS in clinical use are subject, at best, to only perfunctory quality assurance. The goals of this work are (a) to develop an objective and reproducible test for EPID image quality on the factory floor and during installation of the EPID on site; (b) to provide the user with a simple and accurate tool for acceptance, commissioning, and routine quality control; and (c) to initiate regional, national and international collaboration in the implementation of standardized, objective, and automated quality assurance procedures. To this end we have developed an automated test in which a simple test object is imaged daily, and the spatial and contrast resolution of the EPID are automatically evaluated in terms of ''acceptable'', ''warning'' and ''stop'' criteria. Our experience over two years shows the test to be highly sensitive, reproducible, and inexpensive in time and effort. Inter-institutional trials are under way in Canada, US and Europe which indicate large variations in EPID image quality from one EPID to another, and from one center to another. We expect the new standardized quality assurance procedure to lead to improved, and consistent image quality, increased operator acceptance of the technology, and agreement on uniform standards by equipment suppliers and health care agencies. (author)

  4. SU-F-T-260: Using Portal Image Device for Pre-Treatment QA in Volumetric Modulated Arc Plans with Flattening Filter Free (FFF) Beams

    Energy Technology Data Exchange (ETDEWEB)

    Qu, H; Qi, P; Yu, N; Xia, P [The Cleveland Clinic Foundation, Cleveland, OH (United States)

    2016-06-15

    Purpose: To implement and validate a method of using electronic portal image device (EPID) for pre-treatment quality assurance (QA) of volumetric modulated arc therapy (VMAT) plans using flattering filter free (FFF) beams for stereotactic body radiotherapy (SBRT). Methods: On Varian Edge with 6MV FFF beam, open field (from 2×2 cm to 20×20 cm) EPID images were acquired with 200 monitor unit (MU) at the image device to radiation source distance of 150cm. With 10×10 open field and calibration unit (CU) provided by vendor to EPID image pixel, a dose conversion factor was determined by dividing the center dose calculated from the treatment planning system (TPS) to the corresponding CU readout on the image. Water phantom measured beam profile and the output factors for various field sizes were further correlated to those of EPID images. The dose conversion factor and correction factors were then used for converting the portal images to the planner dose distributions of clinical fields. A total of 28 VMAT fields of 14 SBRT plans (8 lung, 2 prostate, 2 liver and 2 spine) were measured. With 10% low threshold cutoff, the delivered dose distributions were compared to the reference doses calculated in water phantom from the TPS. A gamma index analysis was performed for the comparison in percentage dose difference/distance-to-agreement specifications. Results: The EPID device has a linear response to the open fields with increasing MU. For the clinical fields, the gamma indices between the converted EPID dose distributions and the TPS calculated 2D dose distributions were 98.7%±1.1%, 94.0%±3.4% and 70.3%±7.7% for the criteria of 3%/3mm, 2%/2mm and 1%/1mm, respectively. Conclusion: Using a portal image device, a high resolution and high accuracy portal dosimerty was achieved for pre-treatment QA verification for SBRT VMAT plans with FFF beams.

  5. Position measuring device

    International Nuclear Information System (INIS)

    Maeda, Kazuyuki; Takahashi, Shuichi; Maruyama, Mayumi

    1998-01-01

    The present invention provides a device capable of measuring accurate position and distance easily even at places where operator can not easily access, such as cell facilities for vitrifying radioactive wastes. Referring to a case of the vitrifying cell, an objective equipment settled in the cell is photographed by a photographing device. The image is stored in a position measuring device by way of an image input device. After several years, when the objective equipment is exchanged, a new objective equipment is photographed by a photographing device. The image is also stored in the position measuring device. The position measuring device compares the data of both of the images on the basis of pixel unit. Based on the image of the equipment before the exchange as a reference, extent of the displacement of the installation position of the equipment on the image after the exchange caused by installation error and manufacturing error is determined to decide the position of the equipment after exchange relative to the equipment before exchange. (I.S.)

  6. An improved three-dimensional non-scanning laser imaging system based on digital micromirror device

    Science.gov (United States)

    Xia, Wenze; Han, Shaokun; Lei, Jieyu; Zhai, Yu; Timofeev, Alexander N.

    2018-01-01

    Nowadays, there are two main methods to realize three-dimensional non-scanning laser imaging detection, which are detection method based on APD and detection method based on Streak Tube. However, the detection method based on APD possesses some disadvantages, such as small number of pixels, big pixel interval and complex supporting circuit. The detection method based on Streak Tube possesses some disadvantages, such as big volume, bad reliability and high cost. In order to resolve the above questions, this paper proposes an improved three-dimensional non-scanning laser imaging system based on Digital Micromirror Device. In this imaging system, accurate control of laser beams and compact design of imaging structure are realized by several quarter-wave plates and a polarizing beam splitter. The remapping fiber optics is used to sample the image plane of receiving optical lens, and transform the image into line light resource, which can realize the non-scanning imaging principle. The Digital Micromirror Device is used to convert laser pulses from temporal domain to spatial domain. The CCD with strong sensitivity is used to detect the final reflected laser pulses. In this paper, we also use an algorithm which is used to simulate this improved laser imaging system. In the last, the simulated imaging experiment demonstrates that this improved laser imaging system can realize three-dimensional non-scanning laser imaging detection.

  7. Image quality assessment of three limited field-of-view cone-beam computed tomography devices in endodontics

    International Nuclear Information System (INIS)

    Tran, Michel

    2015-01-01

    Since the beginning of Cone Beam Computed Tomography (CBCT) in dento-maxillo-facial radiology, many CBCT devices with different technical aspects and characteristics were produced. Technical variations between CBCT and acquisition settings could involve image quality differences. In order to compare the performance of three limited field-of-view CBCT devices, an objective and subjective evaluation of image quality was carried out using an ex-vivo phantom, which combines both diagnostic and technical features. A significant difference in image quality was found between the five acquisition protocols of the study. (author) [fr

  8. Evaluation of body image and self-esteem in patients with external fixation devices: a Turkish perspective.

    Science.gov (United States)

    Büyükyilmaz, Funda; Sendir, Merdiye; Salmond, Susan

    2009-01-01

    This descriptive study aimed to describe the body image and self-esteem of patients with external fixation devices. Fifty patients with external fixation devices who came for follow-up to the Ilizarov Outpatient Clinic of a university hospital in Turkey were included in this study. Data were collected by using a Demographic Questionnaire Form, Multidimensional Body-Self Relations Questionnaire (MBSRQ), and Coppersmith Self-Esteem Inventory. The perceived body image (197.58 +/- 25.14) and self-esteem (65.28 +/- 17.97) of the patients with external fixation devices were in the moderate range. There was no significant correlation between body image and self-esteem. Self-esteem was correlated with one's perception of whether external fixation impacted one's appearance and whether one wanted to avoid being seen by certain individuals because of the appearance of the external fixator. The study highlighted that body image disturbance and threats to self-esteem are not universal with the use of external fixation and need to be assessed individually.

  9. A newly developed removable dental device for fused 3-D MRI/Meg imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kuboki, Takuo [Okayama Univ. (Japan). Dental School; Clark, G T; Akhtari, M; Sutherling, W W

    1999-06-01

    Recently 3-D imaging techniques have been used to shed light on the role of abnormal brain functions in such conditions as nocturnal bruxism and orofacial pain. In order to achieve precise 3-D image fusion between magnetic resonance images (MRI) and magnetoencephalography (MEG) data, we developed a removable dental device which attaches rigidly to the teeth. Using this device, correlation of MEG and MRI data points was achieved by the co-registration of 3 or more fiducial points. Using a Polhemus 3-space digitizer the locations of the points were registered on MEG and then a small amount of high-water-content material was placed at each point for registering these same points on MRI. The mean reproducibility of interpoint distances, determined for 2 subjects, was between 0.59 and 0.82 mm. Using a Monte Carlo statistical analysis we determined that the accuracy of a posterior projection from the fiducial points to any point within the strata of the brain is {+-}3.3 mm. The value of this device is that it permits reasonably precise and repeatable co-registration of these points and yet it is easily removed and replaced by the patient. Obviously such a device could also be adapted for use in diagnosis and analysis of brain functions related with other various sensory and motor functions (e.g., taste, pain, clenching) in maxillofacial region using MRI and MEG. (author)

  10. A newly developed removable dental device for fused 3-D MRI/Meg imaging

    International Nuclear Information System (INIS)

    Kuboki, Takuo; Clark, G.T.; Akhtari, M.; Sutherling, W.W.

    1999-01-01

    Recently 3-D imaging techniques have been used to shed light on the role of abnormal brain functions in such conditions as nocturnal bruxism and orofacial pain. In order to achieve precise 3-D image fusion between magnetic resonance images (MRI) and magnetoencephalography (MEG) data, we developed a removable dental device which attaches rigidly to the teeth. Using this device, correlation of MEG and MRI data points was achieved by the co-registration of 3 or more fiducial points. Using a Polhemus 3-space digitizer the locations of the points were registered on MEG and then a small amount of high-water-content material was placed at each point for registering these same points on MRI. The mean reproducibility of interpoint distances, determined for 2 subjects, was between 0.59 and 0.82 mm. Using a Monte Carlo statistical analysis we determined that the accuracy of a posterior projection from the fiducial points to any point within the strata of the brain is ±3.3 mm. The value of this device is that it permits reasonably precise and repeatable co-registration of these points and yet it is easily removed and replaced by the patient. Obviously such a device could also be adapted for use in diagnosis and analysis of brain functions related with other various sensory and motor functions (e.g., taste, pain, clenching) in maxillofacial region using MRI and MEG. (author)

  11. Predictive modeling for corrective maintenance of imaging devices from machine logs.

    Science.gov (United States)

    Patil, Ravindra B; Patil, Meru A; Ravi, Vidya; Naik, Sarif

    2017-07-01

    In the cost sensitive healthcare industry, an unplanned downtime of diagnostic and therapy imaging devices can be a burden on the financials of both the hospitals as well as the original equipment manufacturers (OEMs). In the current era of connectivity, it is easier to get these devices connected to a standard monitoring station. Once the system is connected, OEMs can monitor the health of these devices remotely and take corrective actions by providing preventive maintenance thereby avoiding major unplanned downtime. In this article, we present an overall methodology of predicting failure of these devices well before customer experiences it. We use data-driven approach based on machine learning to predict failures in turn resulting in reduced machine downtime, improved customer satisfaction and cost savings for the OEMs. One of the use-case of predicting component failure of PHILIPS iXR system is explained in this article.

  12. OC ToGo: bed site image integration into OpenClinica with mobile devices

    Science.gov (United States)

    Haak, Daniel; Gehlen, Johan; Jonas, Stephan; Deserno, Thomas M.

    2014-03-01

    Imaging and image-based measurements nowadays play an essential role in controlled clinical trials, but electronic data capture (EDC) systems insufficiently support integration of captured images by mobile devices (e.g. smartphones and tablets). The web application OpenClinica has established as one of the world's leading EDC systems and is used to collect, manage and store data of clinical trials in electronic case report forms (eCRFs). In this paper, we present a mobile application for instantaneous integration of images into OpenClinica directly during examination on patient's bed site. The communication between the Android application and OpenClinica is based on the simple object access protocol (SOAP) and representational state transfer (REST) web services for metadata, and secure file transfer protocol (SFTP) for image transfer, respectively. OpenClinica's web services are used to query context information (e.g. existing studies, events and subjects) and to import data into the eCRF, as well as export of eCRF metadata and structural information. A stable image transfer is ensured and progress information (e.g. remaining time) visualized to the user. The workflow is demonstrated for a European multi-center registry, where patients with calciphylaxis disease are included. Our approach improves the EDC workflow, saves time, and reduces costs. Furthermore, data privacy is enhanced, since storage of private health data on the imaging devices becomes obsolete.

  13. Cervical external immobilization devices: evaluation of magnetic resonance imaging issues at 3.0 Tesla.

    Science.gov (United States)

    Diaz, Francis L; Tweardy, Lisa; Shellock, Frank G

    2010-02-15

    Laboratory investigation, ex vivo. Currently, no studies have addressed the magnetic resonance imaging (MRI) issues for cervical external immobilization devices at 3-Tesla. Under certain conditions significant heating may occur, resulting in patient burns. Furthermore, artifacts can be substantial and prevent the diagnostic use of MRI. Therefore, the objective of this investigation was to evaluate MRI issues for 4 different cervical external immobilization devices at 3-Tesla. Excessive heating and substantial artifacts are 2 potential complications associated with performing MRI at 3-Tesla in patients with cervical external immobilization devices. Using ex vivo testing techniques, MRI-related heating and artifacts were evaluated for 4 different cervical devices during MRI at 3-Tesla. Four cervical external immobilization devices (Generation 80, Resolve Ring and Superstructure, Resolve Ring and Jerome Vest/Jerome Superstructure, and the V1 Halo System; Ossur Americas, Aliso Viejo, CA) underwent MRI testing at 3-Tesla. All devices were made from nonmetallic or nonmagnetic materials. Heating was determined using a gelled-saline-filled skull phantom with fluoroptic thermometry probes attached to the skull pins. MRI was performed at 3-Tesla, using a high level of RF energy. Artifacts were assessed at 3-Tesla, using standard cervical imaging techniques. The Generation 80 and V1 Halo devices exhibited substantial temperature rises (11.6 degrees C and 8.5 degrees C, respectively), with "sparking" evident for the Generation 80 during the MRI procedure. Artifacts were problematic for these devices, as well. By comparison, the 2 Resolve Ring-based cervical external immobilization devices showed little or no heating (Tesla.

  14. Improving Science Communication with Responsive Web Design

    Science.gov (United States)

    Hilverda, M.

    2013-12-01

    Effective science communication requires clarity in both content and presentation. Content is increasingly being viewed via the Web across a broad range of devices, which can vary in screen size, resolution, and pixel density. Readers access the same content from desktop computers, tablets, smartphones, and wearable computing devices. Creating separate presentation formats optimized for each device is inefficient and unrealistic as new devices continually enter the marketplace. Responsive web design is an approach that puts content first within a presentation design that responds automatically to its environment. This allows for one platform to be maintained that can be used effectively for every screen. The layout adapts to screens of all sizes ensuring easy viewing of content for readers regardless of their device. Responsive design is accomplished primarily by the use of media queries within style sheets, which allows for changes to layout properties to be defined based on media types (i.e. screen, print) and resolution. Images and other types of multimedia can also be defined to scale automatically to fit different screen dimensions, although some media types require additional effort for proper implementation. Hardware changes, such as high pixel density screens, also present new challenges for effective presentation of content. High pixel density screens contain a greater number of pixels within a screen area increasing the pixels per inch (PPI) compared to standard screens. The result is increased clarity for text and vector media types, but often decreased clarity for standard resolution raster images. Media queries and other custom solutions can assist by specifying higher resolution images for high pixel density screens. Unfortunately, increasing image resolution results in significantly more data being transferred to the device. Web traffic on mobile devices such as smartphones and tablets is on a steady growth trajectory and many mobile devices around

  15. Fuel pattern recognition device

    International Nuclear Information System (INIS)

    Sato, Tomomi.

    1995-01-01

    The device of the present invention monitors normal fuel exchange upon fuel exchanging operation carried out in a reactor of a nuclear power plant. Namely, a fuel exchanger is movably disposed to the upper portion of the reactor and exchanges fuels. An exclusive computer receives operation signals of the fuel exchanger during operation as inputs, and outputs reactor core fuel pattern information signals to a fuel arrangement diagnosis device. An underwater television camera outputs image signals of a fuel pattern in the reactor core to an image processing device. If there is any change in the image signals for the fuel pattern as a result of the fuel exchange operation of the fuel exchanger, the image processing device outputs the change as image signals to the fuel pattern diagnosis device. The fuel pattern diagnosis device compares the pattern information signals from the exclusive computer with the image signals from the image processing device, to diagnose the result of the fuel exchange operation performed by the fuel exchanger and inform the diagnosis by means of an image display. (I.S.)

  16. Optically-tracked handheld fluorescence imaging platform for monitoring skin response in the management of soft tissue sarcoma

    Science.gov (United States)

    Chamma, Emilie; Qiu, Jimmy; Lindvere-Teene, Liis; Blackmore, Kristina M.; Majeed, Safa; Weersink, Robert; Dickie, Colleen I.; Griffin, Anthony M.; Wunder, Jay S.; Ferguson, Peter C.; DaCosta, Ralph S.

    2015-07-01

    Standard clinical management of extremity soft tissue sarcomas includes surgery with radiation therapy. Wound complications (WCs) arising from treatment may occur due to bacterial infection and tissue breakdown. The ability to detect changes in these parameters during treatment may lead to earlier interventions that mitigate WCs. We describe the use of a new system composed of an autofluorescence imaging device and an optical three-dimensional tracking system to detect and coregister the presence of bacteria with radiation doses. The imaging device visualized erythema using white light and detected bacterial autofluorescence using 405-nm excitation light. Its position was tracked relative to the patient using IR reflective spheres and registration to the computed tomography coordinates. Image coregistration software was developed to spatially overlay radiation treatment plans and dose distributions on the white light and autofluorescence images of the surgical site. We describe the technology, its use in the operating room, and standard operating procedures, as well as demonstrate technical feasibility and safety intraoperatively. This new clinical tool may help identify patients at greater risk of developing WCs and investigate correlations between radiation dose, skin response, and changes in bacterial load as biomarkers associated with WCs.

  17. Radiological response of ceramic and polymeric devices for breast brachytherapy

    International Nuclear Information System (INIS)

    Batista Nogueira, Luciana; Passos Ribeiro de Campos, Tarcisio

    2012-01-01

    In the present study, the radiological visibility of ceramic and polymeric devices implanted in breast phantom was investigated for future applications in brachytherapy. The main goal was to determine the radiological viability of ceramic and polymeric devices in vitro by performing simple radiological diagnostic methods such as conventional X-ray analysis and mammography due to its easy access to the population. The radiological response of ceramic and polymeric devices implanted in breast phantom was determined using conventional X-ray, mammography and CT analysis. - Highlights: ► Radiological visibility of ceramic and polymeric devices implanted in breast phantom. ► The barium incorporation in the seed improves the radiological contrast. ► Radiological monitoring shows the position, orientation and degradation of devices. ► Simple radiological methods such as X-ray and mammography were used for radiological monitoring.

  18. Using an Elastic Band Device After a Severe Obstetric Pubic Symphyseal Separation: Clinical and Imaging Evaluation.

    Science.gov (United States)

    Lasbleiz, Jeremy; Sevestre, François-Xavier; Moquet, Pierre-Yves

    2017-09-01

    Severe separation of the pubic symphysis is a rare delivery complication. Facing this pathology, we decided to study a new elastic band device. To evaluate the elastic band device, clinical (pain-rated) and imaging (magnetic resonance imaging and radiography) evaluations with and without the device were performed. The elastic band device is a European Conformity-certified medical device, which is made of neoprene straps, that reduces the mobility of the pelvis and the use of the internal rotator muscles. Once the elastic band device was in place, on postpartum day 1, radiography showed a decrease of the pubic width from 41 to 12 mm. Furthermore, pain decreased from 10 of 10 to 2 of 10 in 2 days, allowing the patient to ambulate and avoid surgery. After 1 month, the pubic width (6 mm) and anatomy were recovered but minor pain was still present with hip rotatory movements. The elastic band device was worn 24 hours a day from postpartum days 1-90 and 12 hours a day from postpartum days 90 to 150; afterward, the patient returned to normal life without the elastic band device. Use of an elastic band device was associated with a reduction of the pubic width and pain associated after obstetric pubic symphysis separation.

  19. Fabrication of fine imaging devices using an external proton microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, T., E-mail: sakai.takuro@jaea.go.jp [Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Yasuda, R.; Iikura, H.; Nojima, T. [Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Koka, M.; Satoh, T.; Ishii, Y. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency (JAEA), Takasaki, Gunma 370-1292 (Japan); Oshima, A. [Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047 (Japan)

    2014-08-01

    We have successfully fabricated novel microscopic imaging devices made from UV/EB curable resin using an external scanning proton microbeam. The devices are micro-structured fluorescent plates that consist of an array of micro-pillars that align periodically. The base material used in the pillars is UV/EB curable resin and each pillar contains phosphor grains. The pattern exposures were performed using a proton beam writing technique. The height of the pillars depends on the range of the proton beam. Optical microscopy and scanning electron microscopy have been used to characterize the samples. The results show that the fabricated fluorescent plates are expected to be compatible with both spatial resolution and detection efficiency.

  20. Features and limitations of mobile tablet devices for viewing radiological images.

    Science.gov (United States)

    Grunert, J H

    2015-03-01

    Mobile radiological image display systems are becoming increasingly common, necessitating a comparison of the features of these systems, specifically the operating system employed, connection to stationary PACS, data security and rang of image display and image analysis functions. In the fall of 2013, a total of 17 PACS suppliers were surveyed regarding the technical features of 18 mobile radiological image display systems using a standardized questionnaire. The study also examined to what extent the technical specifications of the mobile image display systems satisfy the provisions of the Germany Medical Devices Act as well as the provisions of the German X-ray ordinance (RöV). There are clear differences in terms of how the mobile systems connected to the stationary PACS. Web-based solutions allow the mobile image display systems to function independently of their operating systems. The examined systems differed very little in terms of image display and image analysis functions. Mobile image display systems complement stationary PACS and can be used to view images. The impacts of the new quality assurance guidelines (QS-RL) as well as the upcoming new standard DIN 6868 - 157 on the acceptance testing of mobile image display units for the purpose of image evaluation are discussed. © Georg Thieme Verlag KG Stuttgart · New York.

  1. Anti-theft device staining on banknotes detected by mass spectrometry imaging.

    Science.gov (United States)

    Correa, Deleon Nascimento; Zacca, Jorge Jardim; Rocha, Werickson Fortunato de Carvalho; Borges, Rodrigo; de Souza, Wanderley; Augusti, Rodinei; Eberlin, Marcos Nogueira; Vendramini, Pedro Henrique

    2016-03-01

    We describe the identification and limits of detection of ink staining by mass spectrometry imaging (MSI), as used in anti-theft devices (ATDs). Such ink staining is applied to banknotes during automated teller machine (ATM) explosions. Desorption electrospray ionization (DESI) coupled with high-resolution and high-accuracy orbitrap mass spectrometry (MS) and a moving stage device were applied to obtain 2D molecular images of the major dyes used for staining, that is, 1-methylaminoanthraquinone (MAAQ), rhodamine B (RB) and rhodamine 6G (R6G). MAAQ could not be detected because of its inefficient desorption by DESI from the banknote cellulose surface. By contrast, ATD staining on banknotes is perceptible by the human naked eye only at concentrations higher than 0.2 μg cm(-2), whereas both RB and R6G at concentrations 200 times lower (as low as 0.001 μg cm(-2)) could be easily detected and imaged by DESI-MSI, with selective and specific identification of each analyte and their spatial distribution on samples from suspects. This technique is non-destructive, and no sample preparation is required, which ensures sample preservation for further forensic investigations. Copyright © 2016. Published by Elsevier Ireland Ltd.

  2. Blindness and Selective Mutism: One Student's Response to Voice-Output Devices

    Science.gov (United States)

    Holley, Mary; Johnson, Ashli; Herzberg, Tina

    2014-01-01

    This case study was designed to measure the response of one student with blindness and selective mutism to the intervention of voice-output devices across two years and two different teachers in two instructional settings. Before the introduction of the voice output devices, the student did not choose to communicate using spoken language or…

  3. Laser-based irradiation apparatus and method to measure the functional dose-rate response of semiconductor devices

    Science.gov (United States)

    Horn, Kevin M [Albuquerque, NM

    2008-05-20

    A broad-beam laser irradiation apparatus can measure the parametric or functional response of a semiconductor device to exposure to dose-rate equivalent infrared laser light. Comparisons of dose-rate response from before, during, and after accelerated aging of a device, or from periodic sampling of devices from fielded operational systems can determine if aging has affected the device's overall functionality. The dependence of these changes on equivalent dose-rate pulse intensity and/or duration can be measured with the apparatus. The synchronized introduction of external electrical transients into the device under test can be used to simulate the electrical effects of the surrounding circuitry's response to a radiation exposure while exposing the device to dose-rate equivalent infrared laser light.

  4. Real-time volume rendering of digital medical images on an iOS device

    Science.gov (United States)

    Noon, Christian; Holub, Joseph; Winer, Eliot

    2013-03-01

    Performing high quality 3D visualizations on mobile devices, while tantalizingly close in many areas, is still a quite difficult task. This is especially true for 3D volume rendering of digital medical images. Allowing this would empower medical personnel a powerful tool to diagnose and treat patients and train the next generation of physicians. This research focuses on performing real time volume rendering of digital medical images on iOS devices using custom developed GPU shaders for orthogonal texture slicing. An interactive volume renderer was designed and developed with several new features including dynamic modification of render resolutions, an incremental render loop, a shader-based clipping algorithm to support OpenGL ES 2.0, and an internal backface culling algorithm for properly sorting rendered geometry with alpha blending. The application was developed using several application programming interfaces (APIs) such as OpenSceneGraph (OSG) as the primary graphics renderer coupled with iOS Cocoa Touch for user interaction, and DCMTK for DICOM I/O. The developed application rendered volume datasets over 450 slices up to 50-60 frames per second, depending on the specific model of the iOS device. All rendering is done locally on the device so no Internet connection is required.

  5. Characterization of a high-elbow, fluoroscopic electronic portal imaging device for portal dosimetry

    International Nuclear Information System (INIS)

    Boer, J.C.J. de; Visser, A.G.

    2000-01-01

    The application of a newly developed fluoroscopic (CCD-camera based) electronic portal imaging device (EPID) in portal dosimetry is investigated. A description of the EPID response to dose is presented in terms of stability, linearity and optical cross-talk inside the mechanical structure. The EPID has a relatively large distance (41 cm on-axis) between the fluorescent screen and the mirror (high-elbow), which results in cross-talk with properties quite different from that of the low-elbow fluoroscopic EPIDs that have been studied in the literature. In contrast with low-elbow systems, the maximum cross-talk is observed for points of the fluorescent screen that have the largest distance to the mirror, which is explained from the geometry of the system. An algorithm to convert the images of the EPID into portal dose images (PDIs) is presented. The correction applied for cross-talk is a position-dependent additive operation on the EPID image pixel values, with a magnitude that depends on a calculated effective field width. Deconvolution with a point spread function, as applied for low-elbow systems, is not required. For a 25 MV beam, EPID PDIs and ionization chamber measurements in the EPID detector plane were obtained behind an anthropomorphic phantom and a homogeneous absorber for various field shapes. The difference in absolute dose between the EPID and ionization chamber measurements, averaged over the four test fields presented in this paper, was 0.1±0.5% (1 SD) over the entire irradiation field, with no deviation larger than 2%. (author)

  6. Dual-modality imaging with a ultrasound-gamma device for oncology

    Science.gov (United States)

    Polito, C.; Pellegrini, R.; Cinti, M. N.; De Vincentis, G.; Lo Meo, S.; Fabbri, A.; Bennati, P.; Cencelli, V. Orsolini; Pani, R.

    2018-06-01

    Recently, dual-modality systems have been developed, aimed to correlate anatomical and functional information, improving disease localization and helping oncological or surgical treatments. Moreover, due to the growing interest in handheld detectors for preclinical trials or small animal imaging, in this work a new dual modality integrated device, based on a Ultrasounds probe and a small Field of View Single Photon Emission gamma camera, is proposed.

  7. Display device combining ambient light with magnified virtual images generated in the eye path of the observer

    NARCIS (Netherlands)

    2005-01-01

    A display device positions an observer's eye (or eyes) to look in a particular direction (eye path). An electronically controlled image generating element in the eye path generates artificial images which are magnified to create a virtual image for the eye. The image generating element is

  8. Technical Validation of ARTSENS–An Image Free Device for Evaluation of Vascular Stiffness

    Science.gov (United States)

    Radhakrishnan, Ravikumar; Kusmakar, Shitanshu; Thrivikraman, Arya Sree; Sivaprakasam, Mohanasankar

    2015-01-01

    Vascular stiffness is an indicator of cardiovascular health, with carotid artery stiffness having established correlation to coronary heart disease and utility in cardiovascular diagnosis and screening. State of art equipment for stiffness evaluation are expensive, require expertise to operate and not amenable for field deployment. In this context, we developed ARTerial Stiffness Evaluation for Noninvasive Screening (ARTSENS), a device for image free, noninvasive, automated evaluation of vascular stiffness amenable for field use. ARTSENS has a frugal hardware design, utilizing a single ultrasound transducer to interrogate the carotid artery, integrated with robust algorithms that extract arterial dimensions and compute clinically accepted measures of arterial stiffness. The ability of ARTSENS to measure vascular stiffness in vivo was validated by performing measurements on 125 subjects. The accuracy of results was verified with the state-of-the-art ultrasound imaging-based echo-tracking system. The relation between arterial stiffness measurements performed in sitting posture for ARTSENS measurement and sitting/supine postures for imaging system was also investigated to examine feasibility of performing ARTSENS measurements in the sitting posture for field deployment. This paper verified the feasibility of the novel ARTSENS device in performing accurate in vivo measurements of arterial stiffness. As a portable device that performs automated measurement of carotid artery stiffness with minimal operator input, ARTSENS has strong potential for use in large-scale screening. PMID:27170892

  9. Polycaprolactone Thin-Film Micro- and Nanoporous Cell-Encapsulation Devices.

    Science.gov (United States)

    Nyitray, Crystal E; Chang, Ryan; Faleo, Gaetano; Lance, Kevin D; Bernards, Daniel A; Tang, Qizhi; Desai, Tejal A

    2015-06-23

    Cell-encapsulating devices can play an important role in advancing the types of tissue available for transplantation and further improving transplant success rates. To have an effective device, encapsulated cells must remain viable, respond to external stimulus, and be protected from immune responses, and the device itself must elicit a minimal foreign body response. To address these challenges, we developed a micro- and a nanoporous thin-film cell encapsulation device from polycaprolactone (PCL), a material previously used in FDA-approved biomedical devices. The thin-film device construct allows long-term bioluminescent transfer imaging, which can be used for monitoring cell viability and device tracking. The ability to tune the microporous and nanoporous membrane allows selective protection from immune cell invasion and cytokine-mediated cell death in vitro, all while maintaining typical cell function, as demonstrated by encapsulated cells' insulin production in response to glucose stimulation. To demonstrate the ability to track, visualize, and monitor the viability of cells encapsulated in implanted thin-film devices, we encapsulated and implanted luciferase-positive MIN6 cells in allogeneic mouse models for up to 90 days. Lack of foreign body response in combination with rapid neovascularization around the device shows promise in using this technology for cell encapsulation. These devices can help elucidate the metrics required for cell encapsulation success and direct future immune-isolation therapies.

  10. Evaluation of usefulness of portal image using Electronic Portal Imaging Device (EPID) in the patients who received pelvic radiation therapy

    International Nuclear Information System (INIS)

    Kim, Woo Chul; Kim, Heon Jong; Park, Seong Young; Cho, Young Kap; Loh, John J. K.; Park, Won; Suh, Chang Ok; Kim, Gwi Eon

    1998-01-01

    To evaluate the usefulness of electronic portal imaging device through objective compare of the images acquired using an EPID and a conventional port film. From Apr. to Oct. 1997, a total of 150 sets of images from 20 patients who received radiation therapy in the pelvis area were evaluated in the Inha University Hospital and Severance Hospital. A dual image recording technique was devised to obtain both electronic portal images and port film images simultaneously with one treatment course. We did not perform double exposure. Five to ten images were acquired from each patient. All images were acquired from posteroanterior (PA) view except images from two patients. A dose rate of 100-300 MU/min and a 10-MV X-ray beam were used and 2-10 MUs were required to produce a verification image during treatment. Kodak diagnostic film with metal/film imaging cassette which was located on the top of the EPID detector was used for the port film. The source to detector distance was 140 cm. Eight anatomical landmarks (pelvic brim, sacrum, acetabulum, iliopectineal line, symphysis, ischium, obturator foramen, sacroiliac joint) were assessed. Four radiation oncologist joined to evaluate each image. The individual landmarks in the port film or in the EPID were rated-very clear (1), clear (2), visible (3), notclear (4), not visible (5). Using an video camera based EPID system, there was no difference of image quality between no enhanced EPID images and port film images. However, when we provided some change with window level for the portal image, the visibility of the sacrum and obturator foramen was improved in the portal images than in the port film images. All anatomical landmarks were more visible in the portal images than in the port film when we applied the CLAHE mode enhancement. The images acquired using an matrix ion chamber type EPID were also improved image quality after window level adjustment. The quality of image acquired using an electronic portal imaging device was

  11. The effective quality assurance for image guided device using the AMC G-Box

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chong Mi [Dept. of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of)

    2014-12-15

    According to the rapid increase recently in image-guided radiation therapy, It is necessary to control of the image guidance system completely. In particular for the main subject to the accuracy of image guided radiation therapy device to be done essentially the quality assurance. We made efficient phantom in AMC for the management of the accurate and efficient. By setting up of five very important as a quality assurance inventory of the Image guidance system, we made (AMC G-Box) phantom for quality assurance efficient and accurate. Quality assurance list were the Iso-center align, the real measurement, the center align of four direction, the accuracy of table movement and the reproducibility of Hounsfield Unit. The rectangular phantom; acrylic with a thickness of 1 cm to 10 cm × 10 cm × 10 cm was inserted the three materials with different densities respectively for measure the CBCT HU. The phantom was to perform a check of consistency centered by creating a marker that indicates the position of the center fixed. By performing the quality assurance using the phantom of existing, comparing the resulting value to the different resulting value using the AMC G-Box, experiment was analyzed time and problems. Therapy equipment was used Varian device. It was measured twice at 1-week intervals. When implemented quality assurance of an image guidance system using AMC G-Box and a phantom existing has been completed, the quality assurance result is similar in 0.2 mm ± 0.1. In the case of the conventional method, it was 45 minutes at 30 minutes. When using AMC G-Box, it takes 20 minutes 15 minutes, and declined to 50% of the time. The consistency and accurate of image guidance system tend to decline using device. Therefore, We need to perform thoroughly on the quality assurance related. It needs to be checked daily to consistency check especially. When using the AMC G-Box, It is possible to enhance the accuracy of the patient care and equipment efficiently performing

  12. Magnetic resonance imaging of implantable cardiac rhythm devices at 3.0 tesla.

    Science.gov (United States)

    Gimbel, J Rod

    2008-07-01

    A relaxation of the prohibition of scanning cardiac rhythm device patients is underway, largely because of the growing experience of safe scanning events at 1.5T. Magnetic resonance imaging (MRI) at 3T is becoming more common and may pose a different risk profile and outcome of MRI of cardiac device patients. No restrictions were placed on pacemaker dependency, region scanned, device type, or manufacturer. Sixteen scans at 3T were performed with an electrophysiologist present on 14 patients with a variety of devices from various manufacturers. An "MRI-S" strategy was used. Multimodal monitoring was required. Device interrogation was performed prior to, immediately after, and 1-3 months after the MRI. For nonpacemaker-dependent device patients, attempts were made to turn all device features off (with OOO programming the goal) conceptually rendering the device "invisible." In pacemaker-dependent patients, the device was programmed to asynchronous mode at highest output for the duration of the scan with the goal of rendering the device conceptually "invulnerable" to MRI effects. The specific absorption rate (SAR) was limited to 2W/kg. All patients were successfully scanned. No arrhythmias were noted. No significant change in the programmed parameters, pacing thresholds, sensing, impedance, or battery parameters was noted. The insertable loop recorder (ILR) recorded prolonged artifactual asystole during MRI. One patient noted chest burning during the scan. Device patients may undergo carefully tailored 3T MRI scans when pre-MRI reprogramming of the device occurs in conjunction with extensive monitoring, supervision, and follow-up.

  13. Validation of a new imaging device for telemedical ulcer monitoring

    DEFF Research Database (Denmark)

    Rasmussen, Benjamin Schnack; Frøkjær, Johnny; Bisgaard Jørgensen, Line

    2015-01-01

    between the new portable camera and the iPhone images vs. clinical assessment as the 'gold standard'. The study included 36 foot ulcers. Four specialists rated the ulcers and filled out a questionnaire, which formed the basis of the evaluation. RESULTS: We found fair to very good intra-rater agreement...... for the new PID and iPhone, respectively. The gold standard was evaluated by assessing the ulcer twice by two different specialists. Kappa values were moderate to very good with respect to inter-rater agreement except for two variables. The agreement between standard and new equipment compared to the gold......PURPOSE: To clarify whether a new portable imaging device (PID) providing 3D images for telemedical use constitutes a more correct expression of the clinical situation compared to standard telemedical equipment in this case iPhone 4s. METHOD: We investigated intra- and interindividual variability...

  14. Compact plane illumination plugin device to enable light sheet fluorescence imaging of multi-cellular organisms on an inverted wide-field microscope

    OpenAIRE

    Guan, Zeyi; Lee, Juhyun; Jiang, Hao; Dong, Siyan; Jen, Nelson; Hsiai, Tzung; Ho, Chih-Ming; Fei, Peng

    2015-01-01

    We developed a compact plane illumination plugin (PIP) device which enabled plane illumination and light sheet fluorescence imaging on a conventional inverted microscope. The PIP device allowed the integration of microscope with tunable laser sheet profile, fast image acquisition, and 3-D scanning. The device is both compact, measuring approximately 15 by 5 by 5 cm, and cost-effective, since we employed consumer electronics and an inexpensive device molding method. We demonstrated that PIP pr...

  15. Device fabrication, characterization, and thermal neutron detection response of LiZnP and LiZnAs semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Montag, Benjamin W., E-mail: bmontag@ksu.edu; Ugorowski, Philip B.; Nelson, Kyle A.; Edwards, Nathaniel S.; McGregor, Douglas S.

    2016-11-11

    Nowotny-Juza compounds continue to be explored as candidates for solid-state neutron detectors. Such a device would have greater efficiency, in a compact form, than present day gas-filled {sup 3}He and {sup 10}BF{sub 3} detectors. The {sup 6}Li(n,t){sup 4}He reaction yields a total Q-value of 4.78 MeV, larger than {sup 10}B, an energy easily identified above background radiations. Hence, devices fabricated from semiconductor compounds having either natural Li (nominally 7.5% {sup 6}Li) or enriched {sup 6}Li (usually 95% {sup 6}Li) as constituent atoms may provide a material for compact high efficiency neutron detectors. Starting material was synthesized by preparing equimolar portions of Li, Zn, and As sealed under vacuum (10{sup −6} Torr) in quartz ampoules lined with boron nitride and subsequently reacted in a compounding furnace [1]. The raw synthesized material indicated the presence high impurity levels (material and electrical property characterizations). A static vacuum sublimation in quartz was performed to help purify the synthesized material [2,3]. Bulk crystalline samples were grown from the purified material [4,5]. Samples were cut using a diamond wire saw, and processed into devices. Bulk resistivity was determined from I–V curve measurements, ranging from 10{sup 6}–10{sup 11} Ω cm. Devices were characterized for sensitivity to 5.48 MeV alpha particles, 337 nm laser light, and neutron sensitivity in a thermal neutron diffracted beam at the Kansas State University TRIGA Mark II nuclear reactor. Thermal neutron reaction product charge induction was measured with a LiZnP device, and the reaction product spectral response was observed. - Highlights: • Devices were fabricated from in-house synthesized and purified LiZnAs and LiZnP. • Devices ranged in bulk resistivity from 10{sup 6}–10{sup 11} Ω cm. • Devices showed sensitivity to 5.48 MeV alpha particles. • Devices were characterized with a 337 nm laser light. • Devices were evaluated

  16. Semiconductor crystal high resolution imager

    Science.gov (United States)

    Levin, Craig S. (Inventor); Matteson, James (Inventor)

    2011-01-01

    A radiation imaging device (10). The radiation image device (10) comprises a subject radiation station (12) producing photon emissions (14), and at least one semiconductor crystal detector (16) arranged in an edge-on orientation with respect to the emitted photons (14) to directly receive the emitted photons (14) and produce a signal. The semiconductor crystal detector (16) comprises at least one anode and at least one cathode that produces the signal in response to the emitted photons (14).

  17. A time-gated near-infrared spectroscopic imaging device for clinical applications.

    Science.gov (United States)

    Poulet, Patrick; Uhring, Wilfried; Hanselmann, Walter; Glazenborg, René; Nouizi, Farouk; Zint, Virginie; Hirschi, Werner

    2013-03-01

    A time-resolved, spectroscopic, diffuse optical tomography device was assembled for clinical applications like brain functional imaging. The entire instrument lies in a unique setup that includes a light source, an ultrafast time-gated intensified camera and all the electronic control units. The light source is composed of four near infrared laser diodes driven by a nanosecond electrical pulse generator working in a sequential mode at a repetition rate of 100 MHz. The light pulses are less than 80 ps FWHM. They are injected in a four-furcated optical fiber ended with a frontal light distributor to obtain a uniform illumination spot directed towards the head of the patient. Photons back-scattered by the subject are detected by the intensified CCD camera. There are resolved according to their time of flight inside the head. The photocathode is powered by an ultrafast generator producing 50 V pulses, at 100 MHz and a width corresponding to a 200 ps FWHM gate. The intensifier has been specially designed for this application. The whole instrument is controlled by an FPGA based module. All the acquisition parameters are configurable via software through an USB plug and the image data are transferred to a PC via an Ethernet link. The compactness of the device makes it a perfect device for bedside clinical applications. The instrument will be described and characterized. Preliminary data recorded on test samples will be presented.

  18. Enabling Real-Time Volume Rendering of Functional Magnetic Resonance Imaging on an iOS Device.

    Science.gov (United States)

    Holub, Joseph; Winer, Eliot

    2017-12-01

    Powerful non-invasive imaging technologies like computed tomography (CT), ultrasound, and magnetic resonance imaging (MRI) are used daily by medical professionals to diagnose and treat patients. While 2D slice viewers have long been the standard, many tools allowing 3D representations of digital medical data are now available. The newest imaging advancement, functional MRI (fMRI) technology, has changed medical imaging from viewing static to dynamic physiology (4D) over time, particularly to study brain activity. Add this to the rapid adoption of mobile devices for everyday work and the need to visualize fMRI data on tablets or smartphones arises. However, there are few mobile tools available to visualize 3D MRI data, let alone 4D fMRI data. Building volume rendering tools on mobile devices to visualize 3D and 4D medical data is challenging given the limited computational power of the devices. This paper describes research that explored the feasibility of performing real-time 3D and 4D volume raycasting on a tablet device. The prototype application was tested on a 9.7" iPad Pro using two different fMRI datasets of brain activity. The results show that mobile raycasting is able to achieve between 20 and 40 frames per second for traditional 3D datasets, depending on the sampling interval, and up to 9 frames per second for 4D data. While the prototype application did not always achieve true real-time interaction, these results clearly demonstrated that visualizing 3D and 4D digital medical data is feasible with a properly constructed software framework.

  19. Trial making of a positive drawing phantom and its application to whole-body imaging devices

    International Nuclear Information System (INIS)

    Saegusa, Kenji; Arimizu, Noboru; Nakata, Tsuneo; Toyama, Haruo; Shiina, Isamu.

    1980-01-01

    In whole-body RI imaging, there are more instances of the positive pictures detecting the radioisotopes accumulating in morbid positions, such as Tc-99m bone scanning. The phantoms used to mutually compare RI imaging devices and to test their performance employ negative drawing targets embedded rather than positive ones. A simple positive drawing phantom has been made for trial, and applying this to whole-body scanning devices, the performance and the target drawing ability under different scanning conditions were comparatively examined. Though similar to Rollo's phantom, the phantom made for positive drawing uses acryl plate for its outer structure and target portions. The positive targets are cylindrical, and the diameters are 2, 4, 6, 8, 10, and 20 mm, and the subject contrasts are 5, 2, 1, 0.5 and 0.2. The aqueous solution of Tc-99m of about 2 mCi was injected into the phantom, and this was scanned with a whole-body camera and a multi-detector type whole-body scanner. With the phantom pictures close to actual clinical condition, the positive drawing phantom is conveniently capable of comparing the respective imaging devices for intended purposes. (J.P.N.)

  20. Preliminary results on tests of a Cerenkov ring imaging device employing a photoionizing PWC

    Energy Technology Data Exchange (ETDEWEB)

    Durkin, S.; Honma, A.; Leith, D.W.G.S.

    1978-08-01

    A brief description of techniques and problems of ring imaging Cerenkov detectors employing photoionizing PWC's is discussed. Preliminary results on a one dimensional ring imaging device tested at SLAC in May and June of 1978 are then presented. These results include rough measurements of the Cerenkov ring in nitrogen, argon, neon, and helium produced by a collimated positron beam.

  1. Guide-09-1998. Quality control of darkrooms and image display devices

    International Nuclear Information System (INIS)

    2015-01-01

    This guide is applicable to process darkrooms relieved and receiving devices and image displays. A number of methods which require the appointed instrumentation described, some of which can be implemented in own radiology services in the country given the low complexity of themselves and others that require specific equipment and can be performed by specialized groups external to these units.

  2. Living with Smartphones: Does Completion Device Affect Survey Responses?

    Science.gov (United States)

    Lambert, Amber D.; Miller, Angie L.

    2015-01-01

    With the growing reliance on tablets and smartphones for internet access, understanding the effects of completion device on online survey responses becomes increasing important. This study uses data from the Strategic National Arts Alumni Project, a multi-institution online alumni survey designed to obtain knowledge of arts education, to explore…

  3. A protocol for patients with cardiovascular implantable devices undergoing magnetic resonance imaging (MRI): should defibrillation threshold testing be performed post-(MRI).

    Science.gov (United States)

    Burke, Peter Thomas; Ghanbari, Hamid; Alexander, Patrick B; Shaw, Michael K; Daccarett, Marcos; Machado, Christian

    2010-06-01

    Magnetic resonance imaging (MRI) in patients with Cardiovascular Implantable Electronic Devices (CIED) has not been approved by the Food and Drug Administration. Recent data suggests MRI as a relative rather than absolute contraindication in CIED patients. Recently, the American Heart Association has recommended defibrillation threshold testing (DFTT) in implantable cardioverter defibrillator (ICD) patients undergoing MRI. We evaluated the feasibility and safety of a protocol for MRI in CIED patients, incorporating the new recommendations on DFTT. Consecutive patients with CIED undergoing MRI were included. The protocol consisted of continuous monitoring during imaging, device interrogation pre- and post-MRI, reprogramming of the pacemaker to an asynchronous mode in pacemaker-dependent (PMD) patients and a non-tracking/sensing mode for non-PMD patients. All tachyarrhythmia therapies were disabled. Devices were interrogated for lead impedance, battery life, pacing, and sensing thresholds. All patients with ICD underwent DFTT/defibrillator safety margin testing (DSMT) post-MRI. A total of 92 MRI's at 1.5 Tesla were performed in 38 patients. A total of 13 PMD patients, ten ICD patients, four cardiac resynchronization therapy with defibrillator (CRT-D) patients, and 11 non-PMD patients were scanned from four major manufacturers. No device circuitry damage, programming alterations, inappropriate shocks, failure to pace, or changes in sensing, pacing, or defibrillator thresholds were found on single or multiple MRI sessions. Our protocol for MRI in CIED patients appears safe, feasible, and reproducible. This is irrespective of the type of CIED, pacemaker dependancy or multiple 24-h scanning sessions. Our protocol addresses early detection of potential complications and establishes a response system for potential device-related complications. Our observation suggests that routine DFTT/DSMT post-MRI may not be necessary.

  4. Possible way for increasing the quality of imaging from THz passive device

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.; Deng, Chao; Zhao, Yuan-meng; Zhang, Cun-lin; Zhang, Xin

    2011-11-01

    Using the passive THz imaging system developed by the CNU-THz laboratory, we capture the passive THz image of human body with forbidden objects hidden under opaque clothes. We demonstrate the possibility of significant improving the quality of the image. Our approach bases on the application of spatial filters, developed by us for computer treatment of passive THz imaging. The THz imaging system is constructed with accordance to well known passive THz imaging principles and to the THz quasi-optical theory. It contains a scanning mechanism, which has a detector approximately with 1200μm central wavelength, a data acquisition card and a microcomputer. To get a clear imaging of object we apply a sequence of the spatial filters to the image and spectral transforms of the image. The treatment of imaging from the passive THz device is made by computer code. The performance time of treatment of the image, containing about 5000 pixels, is less than 0.1 second. To illustrate the efficiency of developed approach we detect the liquid explosive, knife, pistol and metal plate hidden under opaque clothes. The results obtained demonstrate the high efficiency of our approach for the detection and recognition of the hidden objects and are very promising for the real security application.

  5. Endovascular Device Testing with Particle Image Velocimetry Enhances Undergraduate Biomedical Engineering Education

    Science.gov (United States)

    Nair, Priya; Ankeny, Casey J.; Ryan, Justin; Okcay, Murat; Frakes, David H.

    2016-01-01

    We investigated the use of a new system, HemoFlow™, which utilizes state of the art technologies such as particle image velocimetry to test endovascular devices as part of an undergraduate biomedical engineering curriculum. Students deployed an endovascular stent into an anatomical model of a cerebral aneurysm and measured intra-aneurysmal flow…

  6. A moving image system for cardiovascular nuclear medicine. A dedicated auxiliary device for the total capacity imaging system for multiple plane dynamic colour display

    International Nuclear Information System (INIS)

    Iio, M.; Toyama, H.; Murata, H.; Takaoka, S.

    1981-01-01

    The recent device of the authors, the dedicated multiplane dynamic colour image display system for nuclear medicine, is discussed. This new device is a hardware-based auxiliary moving image system (AMIS) attached to the total capacity image processing system of the authors' department. The major purpose of this study is to develop the dedicated device so that cardiovascular nuclear medicine and other dynamic studies will include the ability to assess the real time delicate processing of the colour selection, edge detection, phased analysis, etc. The auxiliary system consists of the interface for image transferring, four IC refresh memories of 64x64 matrix with 10 bit count depth, a digital 20-in colour TV monitor, a control keyboard and a control panel with potentiometers. This system has five major functions for colour display: (1) A microcomputer board can select any one of 40 different colour tables preset in the colour transformation RAM. This key also provides edge detection at a certain level of the count by leaving the optional colour and setting the rest of the levels at 0 (black); (2) The arithmetic processing circuit performs the operation of the fundamental rules, permitting arithmetic processes of the two images; (3) The colour level control circuit is operated independently by four potentiometers for four refresh image memories, so that the gain and offset of the colour level can be manually and visually controlled to the satisfaction of the operator; (4) The simultaneous CRT display of the maximum four images with or without cinematic motion is possible; (5) The real time movie interval is also adjustable by hardware, and certain frames can be freezed with overlapping of the dynamic frames. Since this system of AMIS is linked with the whole capacity image processing system of the CPU size of 128kW, etc., clinical applications are not limited to cardiovascular nuclear medicine. (author)

  7. Transport Imaging for the Study of Quantum Scattering Phenomena in Next Generation Semiconductor Devices

    National Research Council Canada - National Science Library

    Bradley, Frank M

    2005-01-01

    ...) and highly efficient solar cells. A novel technique has been developed utilizing direct imaging of electron/hole recombination via an optical microscope and a high sensitivity charge coupled device coupled to a scanning electron...

  8. Spherical gradient-index lenses as perfect imaging and maximum power transfer devices.

    Science.gov (United States)

    Gordon, J M

    2000-08-01

    Gradient-index lenses can be viewed from the perspectives of both imaging and nonimaging optics, that is, in terms of both image fidelity and achievable flux concentration. The simple class of gradient-index lenses with spherical symmetry, often referred to as modified Luneburg lenses, is revisited. An alternative derivation for established solutions is offered; the method of Fermat's strings and the principle of skewness conservation are invoked. Then these nominally perfect imaging devices are examined from the additional vantage point of power transfer, and the degree to which they realize the thermodynamic limit to flux concentration is determined. Finally, the spherical gradient-index lens of the fish eye is considered as a modified Luneburg lens optimized subject to material constraints.

  9. Spectral Imaging by Upconversion

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Pedersen, Christian; Tidemand-Lichtenberg, Peter

    2011-01-01

    We present a method to obtain spectrally resolved images using upconversion. By this method an image is spectrally shifted from one spectral region to another wavelength. Since the process is spectrally sensitive it allows for a tailored spectral response. We believe this will allow standard...... silicon based cameras designed for visible/near infrared radiation to be used for spectral images in the mid infrared. This can lead to much lower costs for such imaging devices, and a better performance....

  10. Federal Response Assets for a Radioactive Dispersal Device Incident

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan,T.

    2009-06-30

    If a large scale RDD event where to occur in New York City, the magnitude of the problem would likely exceed the capabilities of City and State to effectively respond to the event. New York State could request Federal Assistance if the United States President has not already made the decision to provide it. The United States Federal Government has a well developed protocol to respond to emergencies. The National Response Framework (NRF) describes the process for responding to all types of emergencies including RDD incidents. Depending on the location and type of event, the NRF involves appropriate Federal Agencies, e.g., Department of Homeland Security (DHS), the Department of Energy (DOE), Environmental Protection Agency (EPA), United States Coast Guard (USCG), Department of Defense (DOD), Department of Justice (DOJ), Department of Agriculture (USDA), and Nuclear Regulatory Commission (NRC). The Federal response to emergencies has been refined and improved over the last thirty years and has been tested on natural disasters (e.g. hurricanes and floods), man-made disasters (oil spills), and terrorist events (9/11). However, the system has never been tested under an actual RDD event. Drills have been conducted with Federal, State, and local agencies to examine the initial (early) phases of such an event (TopOff 2 and TopOff 4). The Planning Guidance for Protection and Recovery Following Radiological Dispersal Device (RDD) and Improvised Nuclear Device (IND) incidents issued by the Department of Homeland Security (DHS) in August 2008 has never been fully tested in an interagency exercise. Recently, another exercise called Empire 09 that was situated in Albany, New York was conducted. Empire 09 consists of 3 different exercises be held in May and June, 2009. The first exercise, May 2009, involved a table top exercise for phase 1 (0-48 hours) of the response to an RDD incident. In early June, a full-scale 3- day exercise was conducted for the mid-phase response (48

  11. A device for identification of respective images in orthogonal localization roentgenograms

    International Nuclear Information System (INIS)

    Ganchev, M.

    1977-01-01

    Some problems which might be solved with the device, originally intended for localization of implanted radioactive wires, include: conjugation check-up of orthogonal localization roentgenograms; localization of partially screened radioactive sources in the patient body; localization of Fletcher's trapezium points in the pelvis; identification of the respective images of contrast filled lymph nodes and localization of some bone hallmarks, visible only on one of two localization roentgenograms. (author)

  12. Safety of Magnetic Resonance Imaging in Patients with Cardiac Devices.

    Science.gov (United States)

    Nazarian, Saman; Hansford, Rozann; Rahsepar, Amir A; Weltin, Valeria; McVeigh, Diana; Gucuk Ipek, Esra; Kwan, Alan; Berger, Ronald D; Calkins, Hugh; Lardo, Albert C; Kraut, Michael A; Kamel, Ihab R; Zimmerman, Stefan L; Halperin, Henry R

    2017-12-28

    Patients who have pacemakers or defibrillators are often denied the opportunity to undergo magnetic resonance imaging (MRI) because of safety concerns, unless the devices meet certain criteria specified by the Food and Drug Administration (termed "MRI-conditional" devices). We performed a prospective, nonrandomized study to assess the safety of MRI at a magnetic field strength of 1.5 Tesla in 1509 patients who had a pacemaker (58%) or an implantable cardioverter-defibrillator (42%) that was not considered to be MRI-conditional (termed a "legacy" device). Overall, the patients underwent 2103 thoracic and nonthoracic MRI examinations that were deemed to be clinically necessary. The pacing mode was changed to asynchronous mode for pacing-dependent patients and to demand mode for other patients. Tachyarrhythmia functions were disabled. Outcome assessments included adverse events and changes in the variables that indicate lead and generator function and interaction with surrounding tissue (device parameters). No long-term clinically significant adverse events were reported. In nine MRI examinations (0.4%; 95% confidence interval, 0.2 to 0.7), the patient's device reset to a backup mode. The reset was transient in eight of the nine examinations. In one case, a pacemaker with less than 1 month left of battery life reset to ventricular inhibited pacing and could not be reprogrammed; the device was subsequently replaced. The most common notable change in device parameters (>50% change from baseline) immediately after MRI was a decrease in P-wave amplitude, which occurred in 1% of the patients. At long-term follow-up (results of which were available for 63% of the patients), the most common notable changes from baseline were decreases in P-wave amplitude (in 4% of the patients), increases in atrial capture threshold (4%), increases in right ventricular capture threshold (4%), and increases in left ventricular capture threshold (3%). The observed changes in lead parameters

  13. BCB Bonding Technology of Back-Side Illuminated COMS Device

    Science.gov (United States)

    Wu, Y.; Jiang, G. Q.; Jia, S. X.; Shi, Y. M.

    2018-03-01

    Back-side illuminated CMOS(BSI) sensor is a key device in spaceborne hyperspectral imaging technology. Compared with traditional devices, the path of incident light is simplified and the spectral response is planarized by BSI sensors, which meets the requirements of quantitative hyperspectral imaging applications. Wafer bonding is the basic technology and key process of the fabrication of BSI sensors. 6 inch bonding of CMOS wafer and glass wafer was fabricated based on the low bonding temperature and high stability of BCB. The influence of different thickness of BCB on bonding strength was studied. Wafer bonding with high strength, high stability and no bubbles was fabricated by changing bonding conditions.

  14. Image guided placement of temporary anchorage devices for tooth movement

    Energy Technology Data Exchange (ETDEWEB)

    Bahl-Palomo, L.; Bissada, N. [Case Western Reserve Univ. School of Dental Medicine, Dept. of Periodontics, Cleveland, OH (United States); Palomo, J.M.; Hans, M.G. [Case Western Reserve Univ. School of Dental Medicine, Dept. of Orthodontics, Cleveland, OH (United States)

    2007-06-15

    The aim of this project is to develop an image guided protocol for placement of a temporary anchorage device without surgically reflecting a mucoperiosteal flap. Eighteen orthodontic cases were selected for skeletal anchorage from the department of orthodontics at Case University. CBCT images of the subjects were taken using the Hitachi CB MercuRay system set at 15 mA, 120 kVp. CBCT images evaluated the ideal location for TAD placement in three dimensions. Horizontal and vertical linear measurements were taken from fixed dental landmarks to clearly define the location for placement. Transverse slices were used to evaluate the thickness of the buccal plate. Using the transverse view, the angle of insertion was determined such that the maximum buccal plate surface area would contact the screw. TADs were placed in the optimum location, with the most appropriate angle of insertion using a closed approach and with minimal local anesthesia and without flap elevation. Results: All TADs were placed without anatomic encroachment and enabled fixed orthodontic anchorage. (orig.)

  15. Image guided placement of temporary anchorage devices for tooth movement

    International Nuclear Information System (INIS)

    Bahl-Palomo, L.; Bissada, N.; Palomo, J.M.; Hans, M.G.

    2007-01-01

    The aim of this project is to develop an image guided protocol for placement of a temporary anchorage device without surgically reflecting a mucoperiosteal flap. Eighteen orthodontic cases were selected for skeletal anchorage from the department of orthodontics at Case University. CBCT images of the subjects were taken using the Hitachi CB MercuRay system set at 15 mA, 120 kVp. CBCT images evaluated the ideal location for TAD placement in three dimensions. Horizontal and vertical linear measurements were taken from fixed dental landmarks to clearly define the location for placement. Transverse slices were used to evaluate the thickness of the buccal plate. Using the transverse view, the angle of insertion was determined such that the maximum buccal plate surface area would contact the screw. TADs were placed in the optimum location, with the most appropriate angle of insertion using a closed approach and with minimal local anesthesia and without flap elevation. Results: All TADs were placed without anatomic encroachment and enabled fixed orthodontic anchorage. (orig.)

  16. Hip fracture discrimination by the Achilles Insight QUS imaging device

    International Nuclear Information System (INIS)

    Damilakis, John; Papadokostakis, George; Perisinakis, Kostas; Maris, Thomas G.; Karantanas, Apostolos H.

    2007-01-01

    The importance of osteoporosis as a major health problem is well recognized. Its major clinical manifestation is low energy fractures. Considerable effort has been directed towards search of noninvasive methods for assessing osteoporotic fracture risk. The aim of this study was to evaluate the ability of quantitative ultrasound (QUS) variables measured by a new heel QUS imaging device to discriminate between postmenopausal women with and without hip fracture. The subjects included 30 postmenopausal female patients with hip fracture and 30 age-matched healthy women. Measurements were acquired using the Achilles Insight QUS imaging device. Bone mineral density (BMD) measurements were carried out using the Lunar Prodigy DXA scanner. Achilles Insight provides images of the heel bone and measures broadband ultrasound attenuation (BUA) and speed of sound (SOS) values in a circular region of interest. A third QUS variable, the stiffness index (SI) was also determined. The short-term precision for healthy subjects was 2.05%, 0.17% and 1.91% for BUA, SOS and SI, respectively. Corresponding values for patients with fractures were 1.80%, 0.16% and 2.04%. All QUS variables measured using the Achilles Insight were significant discriminators of hip fractures (area under ROC curve = 0.77, 0.74 and 0.77 for BUA, SOS and SI, respectively). BMD measurements of the hip had the greatest discriminatory ability (area under ROC curve = 0.88). Statistically significant differences were found between the area under the ROC curve of BMD and the corresponding curves of the QUS variables (P < 0.05 for each of the three comparisons). QUS variables measured by Achilles Insight can be expected to be useful as indicators of the risk of hip fracture in postmenopausal women

  17. The imaging pin detector - a simple and effective new imaging device for soft x-rays and soft beta emissions

    International Nuclear Information System (INIS)

    Bateman, J.E.

    1984-01-01

    The development of a new bidimensional imaging detector system for soft X and beta radiations is reported. Based on the detection of the differential induction signals on pickup electrodes placed around a point anode in a gas avalanche detector, the system described has achieved a spatial resolution of better than 1mm fwhm over a field of 30mm diameter while preserving excellent pulse height resolution. The present device offers considerable potential as a cheap and robust imaging system for applications in X-ray diffraction and autoradiography. (author)

  18. A novel technology: microfluidic devices for microbubble ultrasound contrast agent generation.

    Science.gov (United States)

    Lin, Hangyu; Chen, Junfang; Chen, Chuanpin

    2016-09-01

    Microbubbles are used as ultrasound contrast agents, which enhance ultrasound imaging techniques. In addition, microbubbles currently show promise in disease therapeutics. Microfluidic devices have increased the ability to produce microbubbles with precise size, and high monodispersity compared to microbubbles created using traditional methods. This paper will review several variations in microfluidic device structures used to produce microbubbles as ultrasound contrast agents. Microfluidic device structures include T-junction, and axisymmetric and asymmetric flow-focusing. These devices have made it possible to produce microbubbles that can enter the vascular space; these microbubbles must be less than 10 μm in diameter and have high monodispersity. For different demands of microbubbles production rate, asymmetric flow-focusing devices were divided into individual and integrated devices. In addition, asymmetric flow-focusing devices can produce double layer and multilayer microbubbles loaded with drug or biological components. Details on the mechanisms of both bubble formation and device structures are provided. Finally, microfluidically produced microbubble acoustic responses, microbubble stability, and microbubble use in ultrasound imaging are discussed.

  19. Progress of Terahertz Devices Based on Graphene

    Institute of Scientific and Technical Information of China (English)

    Mai-Xia Fu; Yan Zhang

    2013-01-01

    Graphene is a one-atom-thick planar sheet of sp2-hybridized orbital bonded honeycomb carbon crystal. Its gapless and linear energy spectra of electrons and holes lead to the unique carrier transport and optical properties, such as giant carrier mobility and broadband flat optical response. As a novel material, graphene has been regarded to be extremely suitable and competent for the development of terahertz (THz) optical devices. In this paper, the fundamental electronic and optic properties of graphene are described. Based on the energy band structure and light transmittance properties of graphene, many novel graphene based THz devices have been proposed, including modulator, generator, detector, and imaging device. This progress has been reviewed. Future research directions of the graphene devices for THz applications are also proposed.

  20. Ultra-fast quantitative imaging using ptychographic iterative engine based digital micro-mirror device

    Science.gov (United States)

    Sun, Aihui; Tian, Xiaolin; Kong, Yan; Jiang, Zhilong; Liu, Fei; Xue, Liang; Wang, Shouyu; Liu, Cheng

    2018-01-01

    As a lensfree imaging technique, ptychographic iterative engine (PIE) method can provide both quantitative sample amplitude and phase distributions avoiding aberration. However, it requires field of view (FoV) scanning often relying on mechanical translation, which not only slows down measuring speed, but also introduces mechanical errors decreasing both resolution and accuracy in retrieved information. In order to achieve high-accurate quantitative imaging with fast speed, digital micromirror device (DMD) is adopted in PIE for large FoV scanning controlled by on/off state coding by DMD. Measurements were implemented using biological samples as well as USAF resolution target, proving high resolution in quantitative imaging using the proposed system. Considering its fast and accurate imaging capability, it is believed the DMD based PIE technique provides a potential solution for medical observation and measurements.

  1. Compact plane illumination plugin device to enable light sheet fluorescence imaging of multi-cellular organisms on an inverted wide-field microscope.

    Science.gov (United States)

    Guan, Zeyi; Lee, Juhyun; Jiang, Hao; Dong, Siyan; Jen, Nelson; Hsiai, Tzung; Ho, Chih-Ming; Fei, Peng

    2016-01-01

    We developed a compact plane illumination plugin (PIP) device which enabled plane illumination and light sheet fluorescence imaging on a conventional inverted microscope. The PIP device allowed the integration of microscope with tunable laser sheet profile, fast image acquisition, and 3-D scanning. The device is both compact, measuring approximately 15 by 5 by 5 cm, and cost-effective, since we employed consumer electronics and an inexpensive device molding method. We demonstrated that PIP provided significant contrast and resolution enhancement to conventional microscopy through imaging different multi-cellular fluorescent structures, including 3-D branched cells in vitro and live zebrafish embryos. Imaging with the integration of PIP greatly reduced out-of-focus contamination and generated sharper contrast in acquired 2-D plane images when compared with the stand-alone inverted microscope. As a result, the dynamic fluid domain of the beating zebrafish heart was clearly segmented and the functional monitoring of the heart was achieved. Furthermore, the enhanced axial resolution established by thin plane illumination of PIP enabled the 3-D reconstruction of the branched cellular structures, which leads to the improvement on the functionality of the wide field microscopy.

  2. Effect of post crosslinking haze on the repeatability of Scheimpflug-based and slit-scanning imaging devices

    Directory of Open Access Journals (Sweden)

    Rohit Shetty

    2017-01-01

    Full Text Available Purpose: The aim of this study was to analyze the effect of postcollagen crosslinking (CXL haze on the measurement and repeatability of pachymetry and mean keratometry (Km of four corneal topographers. Materials and Methods: Sixty eyes of sixty patients with progressive keratoconus who had undergone accelerated CXL (ACXL underwent imaging with a scanning slit imaging device (Orbscan II and three Scheimpflug imaging devices (Pentacam HR, Sirius, and Galilei. Post-ACXL haze was measured using the densitometry software on the Pentacam HR. Readings of the thinnest corneal thickness (TCT and Km from three scans of each device were analyzed. Effect of haze on the repeatability of TCT and Km measurements was evaluated using regression models. Repeatability was assessed by coefficient of variation. Results: Corneal densitometry in different zones affected the repeatability of TCT measurement of Orbscan (P < 0.05 significantly but not the repeatability of TCT with Pentacam HR and Sirius (P = 0.03 and 0.05, respectively. Km values were affected by haze when measured with the Pentacam HR (P < 0.05. The repeatability of Km readings for all devices was unaffected by haze. In the anterior 0–2 mm and 2–6 mm zone, TCT (P = 0.43 and 0.45, respectively, Km values (P = 0.4 and 0.6, respectively, repeatability of TCT (P = 0.1 in both zones, and Km (P = 0.5 and 0.1, respectively with Galilei were found to be the most reliable. Conclusion: Galilei measurements appear to be least affected by post-ACXL haze when compared with other devices. Hence, topography measurements in the presence of haze need to be interpreted with caution.

  3. Study on 3D printer production of auxiliary device for upper limb for medical imaging test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyeong Gyun [Dept. of Radiological Science, Far East University, Eumsung (Korea, Republic of); Yoon, Jae Ho [Jukwang Precision Co., Ltd., Gumi (Korea, Republic of); Choi, Seong Dae [Dept. of Mechanical system engineering, Kumoh Institute of Technology, Gumi (Korea, Republic of)

    2015-12-15

    There is a progressive development in the medical imaging technology, especially of descriptive capability for anatomical structure of human body thanks to advancement of information technology and medical devices. But however maintenance of correct posture is essential for the medical imaging checkup on the shoulder joint requiring rotation of the upper limb due to the complexity of human body. In the cases of MRI examination, long duration and fixed posture are critical, as failure to comply with them leads to minimal possibility of reproducibility only with the efforts of the examiner and will of the patient. Thus, this study aimed to develop an auxiliary device that enables rotation of the upper limb as well as fixing it at quantitative angles for medical imaging examination capable of providing diagnostic values. An auxiliary device has been developed based on the results of precedent studies, by designing a 3D model with the CATIA software, an engineering application, and producing it with the 3D printer. The printer is Objet350 Connex from Stratasys, and acrylonitrile- butadiene-styrene(ABS) is used as the material of the device. Dimensions are 120 X 150 X 190 mm, with the inner diameter of the handle being 125.9 mm. The auxiliary device has 4 components including the body (outside), handle (inside), fixture terminal and the connection part. The body and handle have the gap of 2.1 mm for smooth rotation, while the 360 degree of scales have been etched on the handle so that the angle required for observation may be recorded per patient for traceability and dual examination.

  4. Study on 3D printer production of auxiliary device for upper limb for medical imaging test

    International Nuclear Information System (INIS)

    Kim, Hyeong Gyun; Yoon, Jae Ho; Choi, Seong Dae

    2015-01-01

    There is a progressive development in the medical imaging technology, especially of descriptive capability for anatomical structure of human body thanks to advancement of information technology and medical devices. But however maintenance of correct posture is essential for the medical imaging checkup on the shoulder joint requiring rotation of the upper limb due to the complexity of human body. In the cases of MRI examination, long duration and fixed posture are critical, as failure to comply with them leads to minimal possibility of reproducibility only with the efforts of the examiner and will of the patient. Thus, this study aimed to develop an auxiliary device that enables rotation of the upper limb as well as fixing it at quantitative angles for medical imaging examination capable of providing diagnostic values. An auxiliary device has been developed based on the results of precedent studies, by designing a 3D model with the CATIA software, an engineering application, and producing it with the 3D printer. The printer is Objet350 Connex from Stratasys, and acrylonitrile- butadiene-styrene(ABS) is used as the material of the device. Dimensions are 120 X 150 X 190 mm, with the inner diameter of the handle being 125.9 mm. The auxiliary device has 4 components including the body (outside), handle (inside), fixture terminal and the connection part. The body and handle have the gap of 2.1 mm for smooth rotation, while the 360 degree of scales have been etched on the handle so that the angle required for observation may be recorded per patient for traceability and dual examination

  5. Image-Word Pairing-Congruity Effect on Affective Responses

    Science.gov (United States)

    Sanabria Z., Jorge C.; Cho, Youngil; Sambai, Ami; Yamanaka, Toshimasa

    The present study explores the effects of familiarity on affective responses (pleasure and arousal) to Japanese ad elements, based on the schema incongruity theory. Print ads showing natural scenes (landscapes) were used to create the stimuli (images and words). An empirical study was conducted to measure subjects' affective responses to image-word combinations that varied in terms of incongruity. The level of incongruity was based on familiarity levels, and was statistically determined by a variable called ‘pairing-congruity status’. The tested hypothesis proposed that even highly familiar image-word combinations, when combined incongruously, would elicit strong affective responses. Subjects assessed the stimuli using bipolar scales. The study was effective in tracing interactions between familiarity, pleasure and arousal, although the incongruous image-word combinations did not elicit the predicted strong effects on pleasure and arousal. The results suggest a need for further research incorporating kansei (i.e., creativity) into the process of stimuli selection.

  6. Imaging tools to measure treatment response in gout.

    Science.gov (United States)

    Dalbeth, Nicola; Doyle, Anthony J

    2018-01-01

    Imaging tests are in clinical use for diagnosis, assessment of disease severity and as a marker of treatment response in people with gout. Various imaging tests have differing properties for assessing the three key disease domains in gout: urate deposition (including tophus burden), joint inflammation and structural joint damage. Dual-energy CT allows measurement of urate deposition and bone damage, and ultrasonography allows assessment of all three domains. Scoring systems have been described that allow radiological quantification of disease severity and these scoring systems may play a role in assessing the response to treatment in gout. This article reviews the properties of imaging tests, describes the available scoring systems for quantification of disease severity and discusses the challenges and controversies regarding the use of imaging tools to measure treatment response in gout. © The Author 2018. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Fast Fiber-Coupled Imaging Devices

    Energy Technology Data Exchange (ETDEWEB)

    Brockington, Samuel; Case, Andrew; Witherspoon, Franklin

    2018-04-22

    HyperV Technologies Corp. has successfully designed, built and experimentally demonstrated a full scale 1024 pixel 100 MegaFrames/s fiber coupled camera with 12 or 14 bits, and record lengths of 32K frames, exceeding our original performance objectives. This high-pixel-count, fiber optically-coupled, imaging diagnostic can be used for investigating fast, bright plasma events. In Phase 1 of this effort, a 100 pixel fiber-coupled fast streak camera for imaging plasma jet profiles was constructed and successfully demonstrated. The resulting response from outside plasma physics researchers emphasized development of increased pixel performance as a higher priority over increasing pixel count. In this Phase 2 effort, HyperV therefore focused on increasing the sample rate and bit-depth of the photodiode pixel designed in Phase 1, while still maintaining a long record length and holding the cost per channel to levels which allowed up to 1024 pixels to be constructed. Cost per channel was $53.31, very close to our original target of $50 per channel. The system consists of an imaging "camera head" coupled to a photodiode bank with an array of optical fibers. The output of these fast photodiodes is then digitized at 100 Megaframes per second and stored in record lengths of 32,768 samples with bit depths of 12 to 14 bits per pixel. Longer record lengths are possible with additional memory. A prototype imaging system with up to 1024 pixels was designed and constructed and used to successfully take movies of very fast moving plasma jets as a demonstration of the camera performance capabilities. Some faulty electrical components on the 64 circuit boards resulted in only 1008 functional channels out of 1024 on this first generation prototype system. We experimentally observed backlit high speed fan blades in initial camera testing and then followed that with full movies and streak images of free flowing high speed plasma jets (at 30-50 km/s). Jet structure and jet collisions onto

  8. An Implementation of Document Image Reconstruction System on a Smart Device Using a 1D Histogram Calibration Algorithm

    Directory of Open Access Journals (Sweden)

    Lifeng Zhang

    2014-01-01

    Full Text Available In recent years, the smart devices equipped with imaging functions are widely spreading for consumer application. It is very convenient for people to record information using these devices. For example, people can photo one page of a book in a library or they can capture an interesting piece of news on the bulletin board when walking on the street. But sometimes, one shot full area image cannot give a sufficient resolution for OCR soft or for human visual recognition. Therefore, people would prefer to take several partial character images of a readable size and then stitch them together in an efficient way. In this study, we propose a print document acquisition method using a device with a video camera. A one-dimensional histogram based self-calibration algorithm is developed for calibration. Because the calculation cost is low, it can be installed on a smartphone. The simulation result shows that the calibration and stitching are well performed.

  9. Feasibility study on an integrated AEC-grid device for the optimization of image quality and exposure dose in mammography

    Science.gov (United States)

    Kim, Kyo-Tae; Yun, Ryang-Young; Han, Moo-Jae; Heo, Ye-Ji; Song, Yong-Keun; Heo, Sung-Wook; Oh, Kyeong-Min; Park, Sung-Kwang

    2017-10-01

    Currently, in the radiation diagnosis field, mammography is used for the early detection of breast cancer. In addition, studies are being conducted on a grid to produce high-quality images. Although the grid ratio of the grid, which affects the scattering removal rate, must be increased to improve image quality, it increases the total exposure dose. While the use of automatic exposure control is recommended to minimize this problem, existing mammography equipment, unlike general radiography equipment, is mounted on the back of a detector. Therefore, the device is greatly affected by the detector and supporting device, and it is difficult to control the exposure dose. Accordingly, in this research, an integrated AEC-grid device that simultaneously performs AEC and grid functions was used to minimize the unnecessary exposure dose while removing scattering, thereby realizing superior image quality.

  10. A cryogen-free ultralow-field superconducting quantum interference device magnetic resonance imaging system.

    Science.gov (United States)

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

    2014-09-01

    Magnetic resonance imaging (MRI) at microtesla fields using superconducting quantum interference device (SQUID) detection has previously been demonstrated, and advantages have been noted. Although the ultralow-field SQUID MRI technique would not need the heavy superconducting magnet of conventional MRI systems, liquid helium required to cool the low-temperature detector still places a significant burden on its operation. We have built a prototype cryocooler-based SQUID MRI system that does not require a cryogen. The SQUID detector and the superconducting gradiometer were cooled down to 3.7 K and 4.3 K, respectively. We describe the prototype design, characterization, a phantom image, and areas of further improvements needed to bring the imaging performance to parity with conventional MRI systems.

  11. A cryogen-free ultralow-field superconducting quantum interference device magnetic resonance imaging system

    International Nuclear Information System (INIS)

    Eom, Byeong Ho; Penanen, Konstantin; Hahn, Inseob

    2014-01-01

    Magnetic resonance imaging (MRI) at microtesla fields using superconducting quantum interference device (SQUID) detection has previously been demonstrated, and advantages have been noted. Although the ultralow-field SQUID MRI technique would not need the heavy superconducting magnet of conventional MRI systems, liquid helium required to cool the low-temperature detector still places a significant burden on its operation. We have built a prototype cryocooler-based SQUID MRI system that does not require a cryogen. The SQUID detector and the superconducting gradiometer were cooled down to 3.7 K and 4.3 K, respectively. We describe the prototype design, characterization, a phantom image, and areas of further improvements needed to bring the imaging performance to parity with conventional MRI systems

  12. Manifestation of plasmonic response in the detection of sub-terahertz radiation by graphene-based devices

    Science.gov (United States)

    Gayduchenko, I. A.; Fedorov, G. E.; Moskotin, M. V.; Yagodkin, D. I.; Seliverstov, S. V.; Goltsman, G. N.; Kuntsevich, A. Yu; Rybin, M. G.; Obraztsova, E. D.; Leiman, V. G.; Shur, M. S.; Otsuji, T.; Ryzhii, V. I.

    2018-06-01

    We report on the sub-terahertz (THz) (129–450 GHz) photoresponse of devices based on single layer graphene and graphene nanoribbons with asymmetric source and drain (vanadium and gold) contacts. Vanadium forms a barrier at the graphene interface, while gold forms an Ohmic contact. We find that at low temperatures (77 K) the detector responsivity rises with the increasing frequency of the incident sub-THz radiation. We interpret this result as a manifestation of a plasmonic effect in the devices with the relatively long plasmonic wavelengths. Graphene nanoribbon devices display a similar pattern, albeit with a lower responsivity.

  13. Formation of a national network for rapid response to device and lead advisories: The Canadian Heart Rhythm Society Device Advisory Committee

    Science.gov (United States)

    Krahn, Andrew D; Simpson, Christopher S; Parkash, Ratika; Yee, Raymond; Champagne, Jean; Healey, Jeffrey S; Cameron, Doug; Thibault, Bernard; Mangat, Iqwal; Tung, Stanley; Sterns, Laurence; Birnie, David H; Exner, Derek V; Sivakumaran, Soori; Davies, Ted; Coutu, Benoit; Crystal, Eugene; Wolfe, Kevin; Verma, Atul; Stephenson, Elizabeth A; Sanatani, Shubhayan; Gow, Robert; Connors, Sean; Paredes, Felix Ayala; Turabian, Mike; Kus, Teresa; Essebag, Vidal; Gardner, Martin

    2009-01-01

    The Canadian Heart Rhythm Society (CHRS) Device Advisory Committee was commissioned to respond to advisories regarding cardiac rhythm device and lead performance on behalf of the CHRS. In the event of an advisory, the Chair uses an e-mail network to disseminate advisory information to Committee members broadly representative of the Canadian device community. A consensus recommendation is prepared by the Committee and made available to all Canadian centres on the CHRS Web site after approval by the CHRS executive. This collaborative approach using an e-mail network has proven very efficient in providing a rapid national response to device advisories. The network is an ideal tool to collect specific data on implanted device system performance and allows for prompt reporting of clinically relevant data to front-line clinicians and patients. PMID:19584969

  14. Examining the Efficacy of Personal Response Devices in Army Training

    Science.gov (United States)

    Hill, Angelina; Babbitt, Bea

    2013-01-01

    Benefits of personal response devices (PRDs) have been demonstrated in a variety of settings and disciplines in higher education. This study looked outside of higher education to investigate the efficacy of PRDs in an Army training course in terms of trainee performance, engagement, and satisfaction. Instructors were also surveyed to determine…

  15. Detection of fecal contamination on beef meat surfaces using handheld fluorescence imaging device (HFID)

    Science.gov (United States)

    Current meat inspection in slaughter plants, for food safety and quality attributes including potential fecal contamination, is conducted through by visual examination human inspectors. A handheld fluorescence-based imaging device (HFID) was developed to be an assistive tool for human inspectors by ...

  16. Novel PET and Near Infrared Imaging Probes for the Specific Detection of Bacterial Infections Associated With Cardiac Devices.

    Science.gov (United States)

    Takemiya, Kiyoko; Ning, Xinghai; Seo, Wonewoo; Wang, Xiaojian; Mohammad, Rafi; Joseph, Giji; Titterington, Jane S; Kraft, Colleen S; Nye, Jonathan A; Murthy, Niren; Goodman, Mark M; Taylor, W Robert

    2018-04-13

    The aim of this study was to develop imaging agents to detect early stage infections in implantable cardiac devices. Bacteria ingest maltodextrins through the specific maltodextrin transporter. We developed probes conjugated with either a fluorescent dye (maltohexaose fluorescent dye probe [MDP]) or a F-18 (F18 fluoromaltohexaose) and determined their usefulness in a model of infections associated with implanted cardiac devices. Stainless steel mock-ups of medical devices were implanted subcutaneously in rats. On post-operative day 4, animals were injected with either Staphylococcus aureus around the mock-ups to induce a relatively mild infection or oil of turpentine to induce noninfectious inflammation. Animals with a sterile implant were used as control subjects. On post-operative day 6, either the MDP or F18 fluoromaltohexaose was injected intravenously, and the animals were scanned with the appropriate imaging device. Additional positron emission tomography imaging studies were performed with F18-fluorodeoxyglucose as a comparison of the specificity of our probes (n = 5 to 9 per group). The accumulation of the MDP in the infected rats was significantly increased at 1 h after injection when compared with the control and noninfectious inflammation groups (intensity ratio 1.54 ± 0.07 vs. 1.26 ± 0.04 and 1.20 ± 0.05, respectively; p F18 fluoromaltohexaose and F18 fluorodeoxyglucose significantly accumulated in the infected area 30 min after the injection (maximum standard uptake value ratio 4.43 ± 0.30 and 4.87 ± 0.28, respectively). In control rats, there was no accumulation of imaging probes near the device. In the noninfectious inflammation rats, no significant accumulation was observed with F18 fluoromaltohexaose, but F18 fluorodeoxyglucose accumulated in the mock-up area (maximum standard uptake value 2.53 ± 0.39 vs. 4.74 ± 0.46, respectively; p < 0.05). Our results indicate that maltohexaose-based imaging probes are potentially useful for the

  17. Device for imaging an object by means of masks of spatially modulable electromagnetic radiation or corpuscular radiation of high energy

    International Nuclear Information System (INIS)

    Barrett, H.H.

    1979-01-01

    The radiogram of the thyroid is produced by means of a detector device operating similar to a scintillation camera. Between thyroid and detector device there is placed a mask having modulating areas, permeable and impermeable to radiation succeeding each other with decreasing extension. The scanning signal has got the shape of a radar signal with chirp modulation. The filtering unit used for it is a pulse compression filter. The image of the radiation energy distribution on the recording surface of the detector device is thus decoded and compressed to a number of image points giving the picture of the thyroid. (RW) [de

  18. Estimation of four-dimensional dose distribution using electronic portal imaging device in radiation therapy

    International Nuclear Information System (INIS)

    Mizoguchi, Asumi; Arimura, Hidetaka; Shioyama, Yoshiyuki

    2013-01-01

    We are developing a method to evaluate four-dimensional radiation dose distribution in a patient body based upon the animated image of EPID (electronic portal imaging device) which is an image of beam-direction at the irradiation. In the first place, we have obtained the image of the dose which is emitted from patient body at therapy planning using therapy planning CT image and dose evaluation algorism. In the second place, we have estimated the emission dose image at the irradiation using EPID animated image which is obtained at the irradiation. In the third place, we have got an affine transformation matrix including respiratory movement in the body by performing linear registration on the emission dose image at therapy planning to get the one at the irradiation. In the fourth place, we have applied the affine transformation matrix on the therapy planning CT image and estimated the CT image 'at irradiation'. Finally we have evaluated four-dimensional dose distribution by calculating dose distribution in the CT image 'at irradiation' which has been estimated for each frame of the EPID animated-image. This scheme may be useful for evaluating therapy results and risk management. (author)

  19. Fast mega pixels video imaging of a toroidal plasma in KT5D device

    International Nuclear Information System (INIS)

    Xu Min; Wang Zhijiang; Lu Ronghua; Sun Xiang; Wen Yizhi; Yu Changxuan; Wan Shude; Liu Wandong; Wang Jun; Xiao Delong; Yu Yi; Zhu Zhenghua; Hu Linyin

    2005-01-01

    A direct imaging system, viewing visible light emission from plasmas tangentially or perpendicularly, has been set up on the KT5D toroidal device to monitor the real two-dimensional profiles of purely ECR generated plasmas. This system has a typical spatial resolution of 0.2 mm (1280x1024 pixels) when imaging the whole cross section. Interesting features of ECR plasmas have been found. Different from what classical theories have expected, a resonance layer with two or three bright spots, rather than an even vertical band, has been observed. In addition, images also indicate an intermittent splitting and drifting character of the plasmas

  20. Characterizing the Utility and Limitations of Repurposing an Open-Field Optical Imaging Device for Fluorescence-Guided Surgery in Head and Neck Cancer Patients.

    Science.gov (United States)

    Moore, Lindsay S; Rosenthal, Eben L; Chung, Thomas K; de Boer, Esther; Patel, Neel; Prince, Andrew C; Korb, Melissa L; Walsh, Erika M; Young, E Scott; Stevens, Todd M; Withrow, Kirk P; Morlandt, Anthony B; Richman, Joshua S; Carroll, William R; Zinn, Kurt R; Warram, Jason M

    2017-02-01

    The purpose of this study was to assess the potential of U.S. Food and Drug Administration-cleared devices designed for indocyanine green-based perfusion imaging to identify cancer-specific bioconjugates with overlapping excitation and emission wavelengths. Recent clinical trials have demonstrated potential for fluorescence-guided surgery, but the time and cost of the approval process may impede clinical translation. To expedite this translation, we explored the feasibility of repurposing existing optical imaging devices for fluorescence-guided surgery. Consenting patients (n = 15) scheduled for curative resection were enrolled in a clinical trial evaluating the safety and specificity of cetuximab-IRDye800 (NCT01987375). Open-field fluorescence imaging was performed preoperatively and during the surgical resection. Fluorescence intensity was quantified using integrated instrument software, and the tumor-to-background ratio characterized fluorescence contrast. In the preoperative clinic, the open-field device demonstrated potential to guide preoperative mapping of tumor borders, optimize the day of surgery, and identify occult lesions. Intraoperatively, the device demonstrated robust potential to guide surgical resections, as all peak tumor-to-background ratios were greater than 2 (range, 2.2-14.1). Postresection wound bed fluorescence was significantly less than preresection tumor fluorescence (P open-field imaging device was successfully repurposed to distinguish cancer from normal tissue in the preoperative clinic and throughout surgical resection. This study illuminated the potential for existing open-field optical imaging devices with overlapping excitation and emission spectra to be used for fluorescence-guided surgery. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  1. The use of an electronic portal imaging device for exit dosimetry and quality control measurements

    International Nuclear Information System (INIS)

    Kirby, Michael C.; Williams, Peter C.

    1995-01-01

    Purpose: To determine ways in which electronic portal imaging devices (EPIDs) could be used to (a) measure exit doses for external beam radiotherapy and (b) perform quality control checks on linear accelerators. Methods and Materials: When imaging, our fluoroscopic EPID adjusts the gain, offset, and frame acquisition time of the charge coupled device (CCD) camera automatically, to allow for the range of photon transmissions through the patient, and to optimize the signal-to-noise ratio. However, our EPID can be programmed to act as an integrating dosemeter. EPID dosemeter measurements were made for 20 MV photons, for different field sizes and thicknesses of unit density phantom material placed at varying exit surface to detector distances. These were compared with simultaneous Silicon diode exit dose measurements. Our exit dosimetry technique was verified using an anthropomorphic type phantom, and some initial measurements have been made for patients treated with irregularly shaped 20 MV x-ray fields. In this dosimetry mode, our EPID was also used to measure certain quality control parameters, x-ray field flatness, and the verification of segmented intensity modulated field prescriptions. Results: Configured for dosimetry, our EPID exhibited a highly linear response, capable of resolving individual monitor units. Exit doses could be measured to within about 3% of that measured using Silicon diodes. Field flatness was determined to within 1.5% of Farmer dosemeter measurements. Segmented intensity modulated fields can be easily verified. Conclusions: Our EPID has the versatility to assess a range of parameters pertinent to the delivery of high quality, high precision radiotherapy. When configured appropriately, it can measure exit doses in vivo, with reasonable accuracy, perform certain quick quality control checks, and analyze segmented intensity modulated treatment fields

  2. Charge transfer devices and their application in physics

    Energy Technology Data Exchange (ETDEWEB)

    Soroko, L M [Joint Inst. for Nuclear Research, Dubna (USSR)

    1979-01-01

    Physical properties and technical specifications of charge transfer devices (CTD) are reviewed. The CTD are semiconductor devices based on silicon single crystals. The limiting charge density of the CTD, their efficiency of charge transfer, the background noise and radiation effects are considered. Fast response and low energy consumption are characteristic features of the devices. The application of the CTD in storage devices, real time spectral data processing systems and in streamer chambers is described. The algorithms of topological transformations in the stage of scanning particle track images, which can be realized with the help of the CTD are shortly considered. It is pointed out that applications of the CTD in different fields of science and technology are numerous and expanding.

  3. 77 FR 11588 - Certain Electronic Devices for Capturing and Transmitting Images, and Components Thereof

    Science.gov (United States)

    2012-02-27

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-831] Certain Electronic Devices for Capturing and Transmitting Images, and Components Thereof AGENCY: U.S. International Trade Commission... Trade Commission on January 10, 2012, under section 337 of the Tariff Act of 1930, as amended, 19 U.S.C...

  4. 75 FR 39971 - In the Matter of Certain Electronic Imaging Devices; Notice of Investigation

    Science.gov (United States)

    2010-07-13

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-726] In the Matter of Certain Electronic Imaging Devices; Notice of Investigation AGENCY: U.S. International Trade Commission. ACTION: Institution of....S. International Trade Commission on May 13, 2010, under section 337 of the Tariff Act of 1930, as...

  5. Terahertz Detection and Imaging Using Graphene Ballistic Rectifiers.

    Science.gov (United States)

    Auton, Gregory; But, Dmytro B; Zhang, Jiawei; Hill, Ernie; Coquillat, Dominique; Consejo, Christophe; Nouvel, Philippe; Knap, Wojciech; Varani, Luca; Teppe, Frederic; Torres, Jeremie; Song, Aimin

    2017-11-08

    A graphene ballistic rectifier is used in conjunction with an antenna to demonstrate a rectenna as a terahertz (THz) detector. A small-area (<1 μm 2 ) local gate is used to adjust the Fermi level in the device to optimize the output while minimizing the impact on the cutoff frequency. The device operates in both n- and p-type transport regimes and shows a peak extrinsic responsivity of 764 V/W and a corresponding noise equivalent power of 34 pW Hz -1/2 at room temperature with no indications of a cutoff frequency up to 0.45 THz. The device also demonstrates a linear response for more than 3 orders of magnitude of input power due to its zero threshold voltage, quadratic current-voltage characteristics and high saturation current. Finally, the device is used to take an image of an optically opaque object at 0.685 THz, demonstrating potential in both medical and security imaging applications.

  6. An MR-compatible device for delivering smoked marijuana during functional imaging

    OpenAIRE

    Frederick, Blaise deB.; Lindsey, Kimberly P.; Nickerson, Lisa D.; Ryan, Elizabeth T.; Lukas, Scott E.

    2007-01-01

    Smoking is the preferred method of administration for two of the most frequently abused drugs, marijuana and nicotine. The high temporal and spatial resolution of functional magnetic resonance imaging (fMRI) make it a natural choice for studying the neurobiological effects of smoked drugs if the challenges of smoking in a magnetic resonance (MR) scanner can be overcome. We report on a design for an MR-compatible smoking device that can be used for smoking marijuana (or tobacco) during fMRI ex...

  7. Contextual analysis of immunological response through whole-organ fluorescent imaging.

    Science.gov (United States)

    Woodruff, Matthew C; Herndon, Caroline N; Heesters, B A; Carroll, Michael C

    2013-09-01

    As fluorescent microscopy has developed, significant insights have been gained into the establishment of immune response within secondary lymphoid organs, particularly in draining lymph nodes. While established techniques such as confocal imaging and intravital multi-photon microscopy have proven invaluable, they provide limited insight into the architectural and structural context in which these responses occur. To interrogate the role of the lymph node environment in immune response effectively, a new set of imaging tools taking into account broader architectural context must be implemented into emerging immunological questions. Using two different methods of whole-organ imaging, optical clearing and three-dimensional reconstruction of serially sectioned lymph nodes, fluorescent representations of whole lymph nodes can be acquired at cellular resolution. Using freely available post-processing tools, images of unlimited size and depth can be assembled into cohesive, contextual snapshots of immunological response. Through the implementation of robust iterative analysis techniques, these highly complex three-dimensional images can be objectified into sortable object data sets. These data can then be used to interrogate complex questions at the cellular level within the broader context of lymph node biology. By combining existing imaging technology with complex methods of sample preparation and capture, we have developed efficient systems for contextualizing immunological phenomena within lymphatic architecture. In combination with robust approaches to image analysis, these advances provide a path to integrating scientific understanding of basic lymphatic biology into the complex nature of immunological response.

  8. Obtaining and Using Images in the Clinical Setting

    International Nuclear Information System (INIS)

    Cendales, Ricardo

    2009-01-01

    Currently small electronic devices capable of producing high quality images are available. The massive use of these devices has become common in the clinical setting as medical images represent a useful tool to document relevant clinical conditions for patient diagnosis, treatment and follow-up. Besides, clinical images are beneficial for legal, scientific and academic purposes. The extended practice without proper ethical guidelines might represent a significant risk for the protection of patient rights and clinical practice. This document discusses risks and duties when obtaining medical images, and presents some arguments on institutional and professional responsibilities around the definition of policies regarding the protection of privacy and dignity of the patient.

  9. Reliability of measuring pelvic floor elevation with a diagnostic ultrasonic imaging device

    OpenAIRE

    Ubukata, Hitomi; Maruyama, Hitoshi; Huo, Ming

    2015-01-01

    [Purpose] The purpose of this study was to investigate the reliability of measuring the amount of pelvic floor elevation during pelvic and abdominal muscle contraction with a diagnostic ultrasonic imaging device. [Subjects] The study group comprised 11 healthy women without urinary incontinence or previous birth experience. [Methods] We measured the displacement elevation of the bladder base during contraction of the abdominal and pelvic floor muscles was measured using a diagnostic ultrasoni...

  10. Micro and nano devices in passive millimetre wave imaging systems

    Science.gov (United States)

    Appleby, R.

    2013-06-01

    The impact of micro and nano technology on millimetre wave imaging from the post war years to the present day is reviewed. In the 1950s whisker contacted diodes in mixers and vacuum tubes were used to realise both radiometers and radars but required considerable skill to realise the performance needed. Development of planar semiconductor devices such as Gunn and Schottky diodes revolutionised mixer performance and provided considerable improvement. The next major breakthrough was high frequency transistors based on gallium arsenide which were initially used at intermediate frequencies but later after further development at millimeter wave frequencies. More recently Monolithic Microwave Integrated circuits(MMICs) offer exceptional performance and the opportunity for innovative design in passive imaging systems. In the future the use of micro and nano technology will continue to drive system performance and we can expect to see integration of antennae, millimetre wave and sub millimetre wave circuits and signal processing.

  11. Fast, cheap and in control: spectral imaging with handheld devices

    Science.gov (United States)

    Gooding, Edward A.; Deutsch, Erik R.; Huehnerhoff, Joseph; Hajian, Arsen R.

    2017-05-01

    Remote sensing has moved out of the laboratory and into the real world. Instruments using reflection or Raman imaging modalities become faster, cheaper and more powerful annually. Enabling technologies include virtual slit spectrometer design, high power multimode diode lasers, fast open-loop scanning systems, low-noise IR-sensitive array detectors and low-cost computers with touchscreen interfaces. High-volume manufacturing assembles these components into inexpensive portable or handheld devices that make possible sophisticated decision-making based on robust data analytics. Examples include threat, hazmat and narcotics detection; remote gas sensing; biophotonic screening; environmental remediation and a host of other applications.

  12. Multi-modality imaging of tumor phenotype and response to therapy

    Science.gov (United States)

    Nyflot, Matthew J.

    2011-12-01

    Imaging and radiation oncology have historically been closely linked. However, the vast majority of techniques used in the clinic involve anatomical imaging. Biological imaging offers the potential for innovation in the areas of cancer diagnosis and staging, radiotherapy target definition, and treatment response assessment. Some relevant imaging techniques are FDG PET (for imaging cellular metabolism), FLT PET (proliferation), CuATSM PET (hypoxia), and contrast-enhanced CT (vasculature and perfusion). Here, a technique for quantitative spatial correlation of tumor phenotype is presented for FDG PET, FLT PET, and CuATSM PET images. Additionally, multimodality imaging of treatment response with FLT PET, CuATSM, and dynamic contrast-enhanced CT is presented, in a trial of patients receiving an antiangiogenic agent (Avastin) combined with cisplatin and radiotherapy. Results are also presented for translational applications in animal models, including quantitative assessment of proliferative response to cetuximab with FLT PET and quantification of vascular volume with a blood-pool contrast agent (Fenestra). These techniques have clear applications to radiobiological research and optimized treatment strategies, and may eventually be used for personalized therapy for patients.

  13. Dose patient verification during treatment using an amorphous silicon electronic portal imaging device in radiotherapy

    International Nuclear Information System (INIS)

    Berger, Lucie

    2006-01-01

    Today, amorphous silicon electronic portal imaging devices (aSi EPID) are currently used to check the accuracy of patient positioning. However, they are not use for dose reconstruction yet and more investigations are required to allow the use of an aSi EPID for routine dosimetric verification. The aim of this work is first to study the dosimetric characteristics of the EPID available at the Institut Curie and then, to check patient dose during treatment using these EPID. First, performance optimization of the Varian aS500 EPID system is studied. Then, a quality assurance system is set up in order to certify the image quality on a daily basis. An additional study on the dosimetric performance of the aS500 EPID is monitored to assess operational stability for dosimetry applications. Electronic portal imaging device is also a useful tool to improve IMRT quality control. The validation and the quality assurance of a portal dose image prediction system for IMRT pre-treatment quality control are performed. All dynamic IMRT fields are verified in clinical routine with the new method based on portal dosimetry. Finally, a new formalism for in vivo dosimetry using transit dose measured with EPID is developed and validated. The absolute dose measurement issue using aSi EPID is described and the midplane dose determination using in vivo dose measurements in combination with portal imaging is used with 3D-conformal-radiation therapy. (author) [fr

  14. - LAA Occluder View for post-implantation Evaluation (LOVE) - standardized imaging proposal evaluating implanted left atrial appendage occlusion devices by cardiac computed tomography

    International Nuclear Information System (INIS)

    Behnes, Michael; Akin, Ibrahim; Sartorius, Benjamin; Fastner, Christian; El-Battrawy, Ibrahim; Borggrefe, Martin; Haubenreisser, Holger; Meyer, Mathias; Schoenberg, Stefan O.; Henzler, Thomas

    2016-01-01

    A standardized imaging proposal evaluating implanted left atrial appendage (LAA) occlusion devices by cardiac computed tomography angiography (cCTA) has never been investigated. cCTA datasets were acquired on a 3 rd generation dual-source CT system and reconstructed with a slice thickness of 0.5 mm. An interdisciplinary evaluation was performed by two interventional cardiologists and one radiologist on a 3D multi-planar workstation. A standardized multi-planar reconstruction algorithm was developed in order to assess relevant clinical aspects of implanted LAA occlusion devices being outlined within a pictorial essay. The following clinical aspects of implanted LAA occlusion devices were evaluated within the most appropriate cCTA multi-planar reconstruction: (1) topography to neighboring structures, (2) peri-device leaks, (3) coverage of LAA lobes, (4) indirect signs of neo-endothelialization. These are illustrated within concise CT imaging examples emphasizing the potential value of the proposed cCTA imaging algorithm: Starting from anatomical cCTA planes and stepwise angulation planes perpendicular to the base of the LAA devices generates an optimal LAA Occluder View for post-implantation Evaluation (LOVE). Aligned true axial, sagittal and coronal LOVE planes offer a standardized and detailed evaluation of LAA occlusion devices after percutaneous implantation. This pictorial essay presents a standardized imaging proposal by cCTA using multi-planar reconstructions that enables systematical follow-up and comparison of patients after LAA occlusion device implantation. The online version of this article (doi:10.1186/s12880-016-0127-y) contains supplementary material, which is available to authorized users

  15. Radiation detection device and a radiation detection method

    International Nuclear Information System (INIS)

    Blum, A.

    1975-01-01

    A radiation detection device is described including at least one scintillator in the path of radiation emissions from a distributed radiation source; a plurality of photodetectors for viewing each scintillator; a signal processing means, a storage means, and a data processing means that are interconnected with one another and connected to said photodetectors; and display means connected to the data processing means to locate a plurality of radiation sources in said distributed radiation source and to provide an image of the distributed radiation sources. The storage means includes radiation emission response data and location data from a plurality of known locations for use by the data processing means to derive a more accurate image by comparison of radiation responses from known locations with radiation responses from unknown locations. (auth)

  16. PIRATE: pediatric imaging response assessment and targeting environment

    Science.gov (United States)

    Glenn, Russell; Zhang, Yong; Krasin, Matthew; Hua, Chiaho

    2010-02-01

    By combining the strengths of various imaging modalities, the multimodality imaging approach has potential to improve tumor staging, delineation of tumor boundaries, chemo-radiotherapy regime design, and treatment response assessment in cancer management. To address the urgent needs for efficient tools to analyze large-scale clinical trial data, we have developed an integrated multimodality, functional and anatomical imaging analysis software package for target definition and therapy response assessment in pediatric radiotherapy (RT) patients. Our software provides quantitative tools for automated image segmentation, region-of-interest (ROI) histogram analysis, spatial volume-of-interest (VOI) analysis, and voxel-wise correlation across modalities. To demonstrate the clinical applicability of this software, histogram analyses were performed on baseline and follow-up 18F-fluorodeoxyglucose (18F-FDG) PET images of nine patients with rhabdomyosarcoma enrolled in an institutional clinical trial at St. Jude Children's Research Hospital. In addition, we combined 18F-FDG PET, dynamic-contrast-enhanced (DCE) MR, and anatomical MR data to visualize the heterogeneity in tumor pathophysiology with the ultimate goal of adaptive targeting of regions with high tumor burden. Our software is able to simultaneously analyze multimodality images across multiple time points, which could greatly speed up the analysis of large-scale clinical trial data and validation of potential imaging biomarkers.

  17. Transcutaneous Noninvasive Device for the Responsive Delivery of Melatonin in Microgravity., Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Our goal is develop a smart, transcutaneous device for individualized circadian (sleep) therapy by responsive release of melatonin, in microgravity. Additionally,...

  18. Tunable Schottky barrier and high responsivity in graphene/Si-nanotip optoelectronic device

    Science.gov (United States)

    Di Bartolomeo, Antonio; Giubileo, Filippo; Luongo, Giuseppe; Iemmo, Laura; Martucciello, Nadia; Niu, Gang; Fraschke, Mirko; Skibitzki, Oliver; Schroeder, Thomas; Lupina, Grzegorz

    2017-03-01

    We demonstrate tunable Schottky barrier height and record photo-responsivity in a new-concept device made of a single-layer CVD graphene transferred onto a matrix of nanotips patterned on n-type Si wafer. The original layout, where nano-sized graphene/Si heterojunctions alternate to graphene areas exposed to the electric field of the Si substrate, which acts both as diode cathode and transistor gate, results in a two-terminal barristor with single-bias control of the Schottky barrier. The nanotip patterning favors light absorption, and the enhancement of the electric field at the tip apex improves photo-charge separation and enables internal gain by impact ionization. These features render the device a photodetector with responsivity (3 {{A}} {{{W}}}-1 for white LED light at 3 {{mW}} {{{cm}}}-2 intensity) almost an order of magnitude higher than commercial photodiodes. We extensively characterize the voltage and the temperature dependence of the device parameters, and prove that the multi-junction approach does not add extra-inhomogeneity to the Schottky barrier height distribution. We also introduce a new phenomenological graphene/semiconductor diode equation, which well describes the experimental I-V characteristics both in forward and reverse bias.

  19. Standard practice for determining relative image quality response of industrial radiographic imaging systems

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This standard provides a practice whereby industrial radiographic imaging systems may be comparatively assessed using the concept of relative image quality response (RIQR). The RIQR method presented within this practice is based upon the use of equivalent penetrameter sensitivity (EPS) described within Practice E 1025 and subsection 5.2 of this practice. Figure 1 illustrates a relative image quality indicator (RIQI) that has four different steel plaque thicknesses (.015, .010, .008, and .005 in.) sequentially positioned (from top to bottom) on a ¾-in. thick steel plate. The four plaques contain a total of 14 different arrays of penetrameter-type hole sizes designed to render varied conditions of threshold visibility ranging from 1.92 % EPS (at the top) to .94 % EPS (at the bottom) when exposed to nominal 200 keV X-ray radiation. Each “EPS” array consists of 30 identical holes; thus, providing the user with a quantity of threshold sensitivity levels suitable for relative image qualitative response com...

  20. Development of a mini-mobile digital radiography system by using wireless smart devices.

    Science.gov (United States)

    Jeong, Chang-Won; Joo, Su-Chong; Ryu, Jong-Hyun; Lee, Jinseok; Kim, Kyong-Woo; Yoon, Kwon-Ha

    2014-08-01

    The current technologies that trend in digital radiology (DR) are toward systems using portable smart mobile as patient-centered care. We aimed to develop a mini-mobile DR system by using smart devices for wireless connection into medical information systems. We developed a mini-mobile DR system consisting of an X-ray source and a Complementary Metal-Oxide Semiconductor (CMOS) sensor based on a flat panel detector for small-field diagnostics in patients. It is used instead of the systems that are difficult to perform with a fixed traditional device. We also designed a method for embedded systems in the development of portable DR systems. The external interface used the fast and stable IEEE 802.11n wireless protocol, and we adapted the device for connections with Picture Archiving and Communication System (PACS) and smart devices. The smart device could display images on an external monitor other than the monitor in the DR system. The communication modules, main control board, and external interface supporting smart devices were implemented. Further, a smart viewer based on the external interface was developed to display image files on various smart devices. In addition, the advantage of operators is to reduce radiation dose when using remote smart devices. It is integrated with smart devices that can provide X-ray imaging services anywhere. With this technology, it can permit image observation on a smart device from a remote location by connecting to the external interface. We evaluated the response time of the mini-mobile DR system to compare to mobile PACS. The experimental results show that our system outperforms conventional mobile PACS in this regard.

  1. A poly(dimethylsiloxane)-based device enabling time-lapse imaging with high spatial resolution

    International Nuclear Information System (INIS)

    Hirano, Masahiko; Hoshida, Tetsushi; Sakaue-Sawano, Asako; Miyawaki, Atsushi

    2010-01-01

    We have developed a regulator-free device that enables long-term incubation of mammalian cells for epi-fluorescence imaging, based on a concept that the size of sample to be gassed and heated is reduced to observation scale. A poly(dimethylsiloxane) block stamped on a coverslip works as a long-lasting supplier of CO 2 -rich gas to adjust bicarbonate-containing medium in a tiny chamber at physiological pH, and an oil-immersion objective warms cells across the coverslip. A time-lapse imaging experiment using HeLa cells stably expressing fluorescent cell-cycle indicators showed that the cells in the chamber proliferated with normal cell-cycle period over 2 days.

  2. In situ KPFM imaging of local photovoltaic characteristics of structured organic photovoltaic devices.

    Science.gov (United States)

    Watanabe, Satoshi; Fukuchi, Yasumasa; Fukasawa, Masako; Sassa, Takafumi; Kimoto, Atsushi; Tajima, Yusuke; Uchiyama, Masanobu; Yamashita, Takashi; Matsumoto, Mutsuyoshi; Aoyama, Tetsuya

    2014-02-12

    Here, we discuss the local photovoltaic characteristics of a structured bulk heterojunction, organic photovoltaic devices fabricated with a liquid carbazole, and a fullerene derivative based on analysis by scanning kelvin probe force microscopy (KPFM). Periodic photopolymerization induced by an interference pattern from two laser beams formed surface relief gratings (SRG) in the structured films. The surface potential distribution in the SRGs indicates the formation of donor and acceptor spatial distribution. Under illumination, the surface potential reversibly changed because of the generation of fullerene anions and hole transport from the films to substrates, which indicates that we successfully imaged the local photovoltaic characteristics of the structured photovoltaic devices. Using atomic force microscopy, we confirmed the formation of the SRG because of the material migration to the photopolymerized region of the films, which was induced by light exposure through photomasks. The structuring technique allows for the direct fabrication and the control of donor and acceptor spatial distribution in organic photonic and electronic devices with minimized material consumption. This in situ KPFM technique is indispensable to the fabrication of nanoscale electron donor and electron acceptor spatial distribution in the devices.

  3. Preclinical evaluation and intraoperative human retinal imaging with a high-resolution microscope-integrated spectral domain optical coherence tomography device.

    Science.gov (United States)

    Hahn, Paul; Migacz, Justin; O'Donnell, Rachelle; Day, Shelley; Lee, Annie; Lin, Phoebe; Vann, Robin; Kuo, Anthony; Fekrat, Sharon; Mruthyunjaya, Prithvi; Postel, Eric A; Izatt, Joseph A; Toth, Cynthia A

    2013-01-01

    The authors have recently developed a high-resolution microscope-integrated spectral domain optical coherence tomography (MIOCT) device designed to enable OCT acquisition simultaneous with surgical maneuvers. The purpose of this report is to describe translation of this device from preclinical testing into human intraoperative imaging. Before human imaging, surgical conditions were fully simulated for extensive preclinical MIOCT evaluation in a custom model eye system. Microscope-integrated spectral domain OCT images were then acquired in normal human volunteers and during vitreoretinal surgery in patients who consented to participate in a prospective institutional review board-approved study. Microscope-integrated spectral domain OCT images were obtained before and at pauses in surgical maneuvers and were compared based on predetermined diagnostic criteria to images obtained with a high-resolution spectral domain research handheld OCT system (HHOCT; Bioptigen, Inc) at the same time point. Cohorts of five consecutive patients were imaged. Successful end points were predefined, including ≥80% correlation in identification of pathology between MIOCT and HHOCT in ≥80% of the patients. Microscope-integrated spectral domain OCT was favorably evaluated by study surgeons and scrub nurses, all of whom responded that they would consider participating in human intraoperative imaging trials. The preclinical evaluation identified significant improvements that were made before MIOCT use during human surgery. The MIOCT transition into clinical human research was smooth. Microscope-integrated spectral domain OCT imaging in normal human volunteers demonstrated high resolution comparable to tabletop scanners. In the operating room, after an initial learning curve, surgeons successfully acquired human macular MIOCT images before and after surgical maneuvers. Microscope-integrated spectral domain OCT imaging confirmed preoperative diagnoses, such as full-thickness macular hole

  4. Intrasurgical Human Retinal Imaging With Manual Instrument Tracking Using a Microscope-Integrated Spectral-Domain Optical Coherence Tomography Device.

    Science.gov (United States)

    Hahn, Paul; Carrasco-Zevallos, Oscar; Cunefare, David; Migacz, Justin; Farsiu, Sina; Izatt, Joseph A; Toth, Cynthia A

    2015-07-01

    To characterize the first in-human intraoperative imaging using a custom prototype spectral-domain microscope-integrated optical coherence tomography (MIOCT) device during vitreoretinal surgery with instruments in the eye. Under institutional review board approval for a prospective intraoperative study, MIOCT images were obtained at surgical pauses with instruments held static in the vitreous cavity and then concurrently with surgical maneuvers. Postoperatively, MIOCT images obtained at surgical pauses were compared with images obtained with a high-resolution handheld spectral-domain OCT (HHOCT) system with objective endpoints, including acquisition of images acceptable for analysis and identification of predefined macular morphologic or pathologic features. Human MIOCT images were successfully obtained before incision and during pauses in surgical maneuvers. MIOCT imaging confirmed preoperative diagnoses, such as epiretinal membrane, full-thickness macular hole, and vitreomacular traction and demonstrated successful achievement of surgical goals. MIOCT and HHOCT images obtained at surgical pauses in two cohorts of five patients were comparable with greater than or equal to 80% correlation in 80% of patients. Real-time video-imaging concurrent with surgical manipulations enabled, for the first time using this device, visualization of dynamic instrument-retina interaction with targeted OCT tracking. MIOCT is successful for imaging at surgical pauses and for real-time image guidance with implementation of targeted OCT tracking. Even faster acquisition speeds are currently being developed with incorporation of a swept-source MIOCT engine. Further refinements and investigations will be directed toward continued integration for real-time volumetric imaging of surgical maneuvers. Ongoing development of seamless MIOCT systems will likely transform surgical visualization, approaches, and decision-making.

  5. Behavioral responses of three lemur species to different food enrichment devices.

    Science.gov (United States)

    Shapiro, Morgan E; Shapiro, Hannah G; Ehmke, Erin E

    2018-05-01

    Environmental enrichment is a tool used to promote the welfare and well-being of captive animals by encouraging the display of species-specific behaviors and reducing the stress or boredom induced by captive environments. Lemurs are highly endangered, yet few studies have analyzed the behavioral impacts of enrichment on captive populations. We studied the impacts of two novel enrichment devices on three lemur species (ring-tailed lemurs [Lemur catta], red-ruffed lemurs [Varecia rubra], and Coquerel's sifaka [Propithecus coquereli]) to determine both the overall and species-specific impacts of enrichment on lemur behavior. We recorded lemur behavior using the continuous sampling method to obtain behavior duration and analyzed our results using ANOVA Repeated Measures. Results showed enrichment effectiveness differed for each species and that different enrichment devices had varying impacts on lemur behavior across all species. We attributed the differences in species-specific responses to the unique locomotor patterns and methods of diet acquisition of each species, and the variances in behavioral responses across all species to the characteristics of each device. Our study highlights the importance of species-specific enrichment and encourages further research in this field in order to maximize the positive effects of enrichment, which in turn has the potential to affect the overall well-being of captive populations. © 2018 Wiley Periodicals, Inc.

  6. Microfluidic electrochemical device and process for chemical imaging and electrochemical analysis at the electrode-liquid interface in-situ

    Science.gov (United States)

    Yu, Xiao-Ying; Liu, Bingwen; Yang, Li; Zhu, Zihua; Marshall, Matthew J.

    2016-03-01

    A microfluidic electrochemical device and process are detailed that provide chemical imaging and electrochemical analysis under vacuum at the surface of the electrode-sample or electrode-liquid interface in-situ. The electrochemical device allows investigation of various surface layers including diffuse layers at selected depths populated with, e.g., adsorbed molecules in which chemical transformation in electrolyte solutions occurs.

  7. Stable image acquisition for mobile image processing applications

    Science.gov (United States)

    Henning, Kai-Fabian; Fritze, Alexander; Gillich, Eugen; Mönks, Uwe; Lohweg, Volker

    2015-02-01

    Today, mobile devices (smartphones, tablets, etc.) are widespread and of high importance for their users. Their performance as well as versatility increases over time. This leads to the opportunity to use such devices for more specific tasks like image processing in an industrial context. For the analysis of images requirements like image quality (blur, illumination, etc.) as well as a defined relative position of the object to be inspected are crucial. Since mobile devices are handheld and used in constantly changing environments the challenge is to fulfill these requirements. We present an approach to overcome the obstacles and stabilize the image capturing process such that image analysis becomes significantly improved on mobile devices. Therefore, image processing methods are combined with sensor fusion concepts. The approach consists of three main parts. First, pose estimation methods are used to guide a user moving the device to a defined position. Second, the sensors data and the pose information are combined for relative motion estimation. Finally, the image capturing process is automated. It is triggered depending on the alignment of the device and the object as well as the image quality that can be achieved under consideration of motion and environmental effects.

  8. PRESBYOPIA OPTOMETRY METHOD BASED ON DIOPTER REGULATION AND CHARGE COUPLE DEVICE IMAGING TECHNOLOGY.

    Science.gov (United States)

    Zhao, Q; Wu, X X; Zhou, J; Wang, X; Liu, R F; Gao, J

    2015-01-01

    With the development of photoelectric technology and single-chip microcomputer technology, objective optometry, also known as automatic optometry, is becoming precise. This paper proposed a presbyopia optometry method based on diopter regulation and Charge Couple Device (CCD) imaging technology and, in the meantime, designed a light path that could measure the system. This method projects a test figure to the eye ground and then the reflected image from the eye ground is detected by CCD. The image is then automatically identified by computer and the far point and near point diopters are determined to calculate lens parameter. This is a fully automatic objective optometry method which eliminates subjective factors of the tested subject. Furthermore, it can acquire the lens parameter of presbyopia accurately and quickly and can be used to measure the lens parameter of hyperopia, myopia and astigmatism.

  9. Micro-/nanoscale multi-field coupling in nonlinear photonic devices

    Science.gov (United States)

    Yang, Qing; Wang, Yubo; Tang, Mingwei; Xu, Pengfei; Xu, Yingke; Liu, Xu

    2017-08-01

    The coupling of mechanics/electronics/photonics may improve the performance of nanophotonic devices not only in the linear region but also in the nonlinear region. This review letter mainly presents the recent advances on multi-field coupling in nonlinear photonic devices. The nonlinear piezoelectric effect and piezo-phototronic effects in quantum wells and fibers show that large second-order nonlinear susceptibilities can be achieved, and second harmonic generation and electro-optic modulation can be enhanced and modulated. Strain engineering can tune the lattice structures and induce second order susceptibilities in central symmetry semiconductors. By combining the absorption-based photoacoustic effect and intensity-dependent photobleaching effect, subdiffraction imaging can be achieved. This review will also discuss possible future applications of these novel effects and the perspective of their research. The review can help us develop a deeper knowledge of the substance of photon-electron-phonon interaction in a micro-/nano- system. Moreover, it can benefit the design of nonlinear optical sensors and imaging devices with a faster response rate, higher efficiency, more sensitivity and higher spatial resolution which could be applied in environmental detection, bio-sensors, medical imaging and so on.

  10. X-ray diagnostic device with an X-ray image amplifier, whose output image is fed into a movie camera, as well as a brightness control

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, H

    1978-02-09

    The X-ray relief appearing behind a patient is immediately or with amplificating foils converted into a latent film image. By using a X-ray image amplifier the X-ray relief is then converted into a reduced and brighter optical image and fed into a photographic or movie camera and shot. To avoid a reduction in the image quality by quantum noise and a too large patient and physician dose a brightness control is provided for the X-ray diagnostic device. The control only dims as far as a brightness per image is produced that avoids quantum noise. On the other side it opens more by strongly beam absorbing patients or a smaller imaging ratio of the X-ray image amplifier to obtain a desired irradiation.

  11. Real-time x-ray response of biocompatible solution gate AlGaN/GaN high electron mobility transistor devices

    International Nuclear Information System (INIS)

    Hofstetter, Markus; Funk, Maren; Paretzke, Herwig G.; Thalhammer, Stefan; Howgate, John; Sharp, Ian D.; Stutzmann, Martin

    2010-01-01

    We present the real-time x-ray irradiation response of charge and pH sensitive solution gate AlGaN/GaN high electron mobility transistors. The devices show stable and reproducible behavior under and following x-ray radiation, including a linear integrated response with dose into the μGy range. Titration measurements of devices in solution reveal that the linear pH response and sensitivity are not only retained under x-ray irradiation, but an irradiation response could also be measured. Since the devices are biocompatible, and can be simultaneously operated in aggressive fluids and under hard radiation, they are well-suited for both medical radiation dosimetry and biosensing applications.

  12. Nanometer-scale temperature imaging for independent observation of Joule and Peltier effects in phase change memory devices.

    Science.gov (United States)

    Grosse, Kyle L; Pop, Eric; King, William P

    2014-09-01

    This paper reports a technique for independent observation of nanometer-scale Joule heating and thermoelectric effects, using atomic force microscopy (AFM) based measurements of nanometer-scale temperature fields. When electrical current flows through nanoscale devices and contacts the temperature distribution is governed by both Joule and thermoelectric effects. When the device is driven by an electrical current that is both periodic and bipolar, the temperature rise due to the Joule effect is at a different harmonic than the temperature rise due to the Peltier effect. An AFM tip scanning over the device can simultaneously measure all of the relevant harmonic responses, such that the Joule effect and the Peltier effect can be independently measured. Here we demonstrate the efficacy of the technique by measuring Joule and Peltier effects in phase change memory devices. By comparing the observed temperature responses of these working devices, we measure the device thermopower, which is in the range of 30 ± 3 to 250 ± 10 μV K(-1). This technique could facilitate improved measurements of thermoelectric phenomena and properties at the nanometer-scale.

  13. Nanometer-scale temperature imaging for independent observation of Joule and Peltier effects in phase change memory devices

    Energy Technology Data Exchange (ETDEWEB)

    Grosse, Kyle L. [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Pop, Eric [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); King, William P., E-mail: wpk@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Departments of Electrical and Computer Engineering and Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2014-09-15

    This paper reports a technique for independent observation of nanometer-scale Joule heating and thermoelectric effects, using atomic force microscopy (AFM) based measurements of nanometer-scale temperature fields. When electrical current flows through nanoscale devices and contacts the temperature distribution is governed by both Joule and thermoelectric effects. When the device is driven by an electrical current that is both periodic and bipolar, the temperature rise due to the Joule effect is at a different harmonic than the temperature rise due to the Peltier effect. An AFM tip scanning over the device can simultaneously measure all of the relevant harmonic responses, such that the Joule effect and the Peltier effect can be independently measured. Here we demonstrate the efficacy of the technique by measuring Joule and Peltier effects in phase change memory devices. By comparing the observed temperature responses of these working devices, we measure the device thermopower, which is in the range of 30 ± 3 to 250 ± 10 μV K{sup −1}. This technique could facilitate improved measurements of thermoelectric phenomena and properties at the nanometer-scale.

  14. Large-scale automated image analysis for computational profiling of brain tissue surrounding implanted neuroprosthetic devices using Python.

    Science.gov (United States)

    Rey-Villamizar, Nicolas; Somasundar, Vinay; Megjhani, Murad; Xu, Yan; Lu, Yanbin; Padmanabhan, Raghav; Trett, Kristen; Shain, William; Roysam, Badri

    2014-01-01

    In this article, we describe the use of Python for large-scale automated server-based bio-image analysis in FARSIGHT, a free and open-source toolkit of image analysis methods for quantitative studies of complex and dynamic tissue microenvironments imaged by modern optical microscopes, including confocal, multi-spectral, multi-photon, and time-lapse systems. The core FARSIGHT modules for image segmentation, feature extraction, tracking, and machine learning are written in C++, leveraging widely used libraries including ITK, VTK, Boost, and Qt. For solving complex image analysis tasks, these modules must be combined into scripts using Python. As a concrete example, we consider the problem of analyzing 3-D multi-spectral images of brain tissue surrounding implanted neuroprosthetic devices, acquired using high-throughput multi-spectral spinning disk step-and-repeat confocal microscopy. The resulting images typically contain 5 fluorescent channels. Each channel consists of 6000 × 10,000 × 500 voxels with 16 bits/voxel, implying image sizes exceeding 250 GB. These images must be mosaicked, pre-processed to overcome imaging artifacts, and segmented to enable cellular-scale feature extraction. The features are used to identify cell types, and perform large-scale analysis for identifying spatial distributions of specific cell types relative to the device. Python was used to build a server-based script (Dell 910 PowerEdge servers with 4 sockets/server with 10 cores each, 2 threads per core and 1TB of RAM running on Red Hat Enterprise Linux linked to a RAID 5 SAN) capable of routinely handling image datasets at this scale and performing all these processing steps in a collaborative multi-user multi-platform environment. Our Python script enables efficient data storage and movement between computers and storage servers, logs all the processing steps, and performs full multi-threaded execution of all codes, including open and closed-source third party libraries.

  15. Large-scale automated image analysis for computational profiling of brain tissue surrounding implanted neuroprosthetic devices using Python

    Directory of Open Access Journals (Sweden)

    Nicolas eRey-Villamizar

    2014-04-01

    Full Text Available In this article, we describe use of Python for large-scale automated server-based bio-image analysis in FARSIGHT, a free and open-source toolkit of image analysis methods for quantitative studies of complex and dynamic tissue microenvironments imaged by modern optical microscopes including confocal, multi-spectral, multi-photon, and time-lapse systems. The core FARSIGHT modules for image segmentation, feature extraction, tracking, and machine learning are written in C++, leveraging widely used libraries including ITK, VTK, Boost, and Qt. For solving complex image analysis task, these modules must be combined into scripts using Python. As a concrete example, we consider the problem of analyzing 3-D multi-spectral brain tissue images surrounding implanted neuroprosthetic devices, acquired using high-throughput multi-spectral spinning disk step-and-repeat confocal microscopy. The resulting images typically contain 5 fluorescent channels, 6,000$times$10,000$times$500 voxels with 16 bits/voxel, implying image sizes exceeding 250GB. These images must be mosaicked, pre-processed to overcome imaging artifacts, and segmented to enable cellular-scale feature extraction. The features are used to identify cell types, and perform large-scale analytics for identifying spatial distributions of specific cell types relative to the device. Python was used to build a server-based script (Dell 910 PowerEdge servers with 4 sockets/server with 10 cores each, 2 threads per core and 1TB of RAM running on Red Hat Enterprise Linux linked to a RAID 5 SAN capable of routinely handling image datasets at this scale and performing all these processing steps in a collaborative multi-user multi-platform environment consisting. Our Python script enables efficient data storage and movement between compute and storage servers, logging all processing steps, and performs full multi-threaded execution of all codes, including open and closed-source third party libraries.

  16. Device model for pixelless infrared image up-converters based on polycrystalline graphene heterostructures

    Science.gov (United States)

    Ryzhii, V.; Shur, M. S.; Ryzhii, M.; Karasik, V. E.; Otsuji, T.

    2018-01-01

    We developed a device model for pixelless converters of far/mid-infrared radiation (FIR/MIR) images into near-infrared/visible (NIR/VIR) images. These converters use polycrystalline graphene layers (PGLs) immersed in the van der Waals materials integrated with a light emitting diode (LED). The PGL serves as an element of the PGL infrared photodetector (PGLIP) sensitive to the incoming FIR/MIR due to the interband absorption. The spatially non-uniform photocurrent generated in the PGLIP repeats (mimics) the non-uniform distribution (image) created by the incident FIR/MIR. The injection of the nonuniform photocurrent into the LED active layer results in the nonuniform NIR/VIR image reproducing the FIR/MIR image. The PGL and the entire layer structure are not deliberately partitioned into pixels. We analyze the characteristics of such pixelless PGLIP-LED up-converters and show that their image contrast transfer function and the up-conversion efficiency depend on the PGL lateral resistivity. The up-converter exhibits high photoconductive gain and conversion efficiency when the lateral resistivity is sufficiently high. Several teams have successfully demonstrated the large area PGLs with the resistivities varying in a wide range. Such layers can be used in the pixelless PGLIP-LED image up-converters. The PGLIP-LED image up-converters can substantially surpass the image up-converters based on the quantum-well infrared photodetector integrated with the LED. These advantages are due to the use of the interband FIR/NIR absorption and a high photoconductive gain in the GLIPs.

  17. Imaging assessment of a portable hemodialysis device: detection of possible failure modes and monitoring of functional performance.

    Science.gov (United States)

    Olorunsola, Olufoladare G; Kim, Steven H; Chang, Ryan; Kuo, Yuo-Chen; Hetts, Steven W; Heller, Alex; Kant, Rishi; Saeed, Maythem; Fissell, William H; Roy, Shuvo; Wilson, Mark W

    2014-03-27

    The purpose of this study was to investigate the utility and limitations of various imaging modalities in the noninvasive assessment of a novel compact hemodialyzer under development for renal replacement therapy, with specific aim towards monitoring its functional performance. The prototype is a 4×3×6 cm aluminum cartridge housing "blood" and "dialysate" flow paths arranged in parallel. A sheet of semipermeable silicon nanopore membranes forms the blood-dialysate interface, allowing passage of small molecules. Blood flow was simulated using a peristaltic pump to instill iodinated contrast through the blood compartment, while de-ionized water was instilled through the dialysate compartment at a matched rate in the countercurrent direction. Images were acquired under these flow conditions using multi-detector computed tomography (MDCT), fluoroscopy, high-resolution quantitative computed tomography (HR-QCT), and magnetic resonance imaging (MRI). MDCT was used to monitor contrast diffusion efficiency by plotting contrast density as a function of position along the path of flow through the cartridge during steady state infusion at 1 and 20 mL/min. Both linear and exponential regressions were used to model contrast decay along the flow path. Both linear and exponential models of contrast decay appeared to be reasonable approximations, yielding similar results for contrast diffusion during a single pass through the cartridge. There was no measurable difference in contrast diffusion when comparing 1 mL/min and 20 mL/min flow rates. Fluoroscopy allowed a gross qualitative assessment of flow within the device, and revealed flow inhomogeneity within the corner of the cartridge opposite the blood inlet port. MRI and HR-QCT were both severely limited due to the paramagnetic properties and high atomic number of the target material, respectively. During testing, we encountered several causes of device malfunction, including leak formation, trapped gas, and contrast

  18. Aberration-free FTIR spectroscopic imaging of live cells in microfluidic devices.

    Science.gov (United States)

    Chan, K L Andrew; Kazarian, Sergei G

    2013-07-21

    The label-free, non-destructive chemical analysis offered by FTIR spectroscopic imaging is a very attractive and potentially powerful tool for studies of live biological cells. FTIR imaging of live cells is a challenging task, due to the fact that cells are cultured in an aqueous environment. While the synchrotron facility has proven to be a valuable tool for FTIR microspectroscopic studies of single live cells, we have demonstrated that high quality infrared spectra of single live cells using an ordinary Globar source can also be obtained by adding a pair of lenses to a common transmission liquid cell. The lenses, when placed on the transmission cell window, form pseudo hemispheres which removes the refraction of light and hence improve the imaging and spectral quality of the obtained data. This study demonstrates that infrared spectra of single live cells can be obtained without the focus shifting effect at different wavenumbers, caused by the chromatic aberration. Spectra of the single cells have confirmed that the measured spectral region remains in focus across the whole range, while spectra of the single cells measured without the lenses have shown some erroneous features as a result of the shift of focus. It has also been demonstrated that the addition of lenses can be applied to the imaging of cells in microfabricated devices. We have shown that it was not possible to obtain a focused image of an isolated cell in a droplet of DPBS in oil unless the lenses are applied. The use of the approach described herein allows for well focused images of single cells in DPBS droplets to be obtained.

  19. X-ray diagnostic device with an X-ray image amplifier, whose output image is fed into a movie camera, as well as a brightness control

    International Nuclear Information System (INIS)

    Lutz, H.

    1978-01-01

    The X-ray relief appearing behind a patient is immediately or with amplificating foils converted into a latent film image. By using a X-ray image amplifier the X-ray relief is then converted into a reduced and brighter optical image and fed into a photographic or movie camera and shot. To avoid a reduction in the image quality by quantum noise and a too large patient and physician dose a brightness control is provided for the X-ray diagnostic device. The control only dims as far as a brightness per image is produced that avoids quantum noise. On the other side it opens more by strongly beam absorbing patients or a smaller imaging ratio of the X-ray image amplifier to obtain a desired irradiation. (DG) [de

  20. Using an electronic portal imaging device for exit dose measurements in radiotherapy

    International Nuclear Information System (INIS)

    Ganowicz, M.; Wozniak, B.; Bekman, A.; Maniakowski, Z.

    2003-01-01

    To present a method of determining the exit dose with the use of an electronic portal imaging device (EPID). The device used was the Portal Vision LC250 (Varian). The EPID signals on the central beam axis have been related to the exit dose. The exit dose measurements were performed with the ionisation chamber in the slab phantom at the distance of dose maximum from the exit surface of the phantom. EPID reading was investigated as a function of field size, phantom thickness and source-detector distance. The relation between dose rate and the EPID reading is described with empirical functions applicable to the obtained data. The exit dose is calculated from the EPID reading as a product of the calibration factor and appropriate correction factors. The determination of the exit dose rate from the EPID signal requires the knowledge of many parameters and earlier determination of essential characteristics. (author)

  1. Detection and response to unauthorized access to a communication device

    Science.gov (United States)

    Smith, Rhett; Gordon, Colin

    2015-09-08

    A communication gateway consistent with the present disclosure may detect unauthorized physical or electronic access and implement security actions in response thereto. A communication gateway may provide a communication path to an intelligent electronic device (IED) using an IED communications port configured to communicate with the IED. The communication gateway may include a physical intrusion detection port and a network port. The communication gateway may further include control logic configured to evaluate physical intrusion detection signal. The control logic may be configured to determine that the physical intrusion detection signal is indicative of an attempt to obtain unauthorized access to one of the communication gateway, the IED, and a device in communication with the gateway; and take a security action based upon the determination that the indication is indicative of the attempt to gain unauthorized access.

  2. Controlled power delivery for super-resolution imaging of biological samples using digital micromirror device

    Science.gov (United States)

    Valiya Peedikakkal, Liyana; Cadby, Ashley

    2017-02-01

    Localization based super resolution images of a biological sample is generally achieved by using high power laser illumination with long exposure time which unfortunately increases photo-toxicity of a sample, making super resolution microscopy, in general, incompatible with live cell imaging. Furthermore, the limitation of photobleaching reduces the ability to acquire time lapse images of live biological cells using fluorescence microscopy. Digital Light Processing (DLP) technology can deliver light at grey scale levels by flickering digital micromirrors at around 290 Hz enabling highly controlled power delivery to samples. In this work, Digital Micromirror Device (DMD) is implemented in an inverse Schiefspiegler telescope setup to control the power and pattern of illumination for super resolution microscopy. We can achieve spatial and temporal patterning of illumination by controlling the DMD pixel by pixel. The DMD allows us to control the power and spatial extent of the laser illumination. We have used this to show that we can reduce the power delivered to the sample to allow for longer time imaging in one area while achieving sub-diffraction STORM imaging in another using higher power densities.

  3. Determination of the size of an imaging data storage device at a full PACS hospital

    International Nuclear Information System (INIS)

    Cha, S. J.; Kim, Y. H.; Hur, G.

    2000-01-01

    To determine the appropriate size of a short and long-term storage device, bearing in mind the design factors involved and the installation costs. The number of radiologic studies quoted is the number of these undertaken during a one-year period at a university hospital with 650 beds, and reflects the actual number of each type of examination performed at a full PACS hospital. The average daily number of outpatients was 1586, while that of inpatients was 639.5. The numbers of radiologic studies performed were as follows : 378 among 189 outpatients, and 165 among 41 inpatients. The average daily number of examinations was 543, comprising 460 CR, 30 ultrasonograms, 25 CT, 8 MRI, 20 others. The total amount of digital images was 17.4 GB per day, while the amount of short-term data with lossless compression was 6.7 GB per day. During 14 days short-term storage, the amount of image data was 93.7 GB in disk array. The amount of data stored mid term (1 year), with lossy compression, was 369.1 GB. The amount of data stored in the form of long-term cache and educational images was 38.7 GB and 30 GB, respectively, The total size of disk array was 531.5 GB. A device suitable for the long-term storage of images, for at least five years, requires a capacity of 1845.5 GB. At a full PACS hospital with 600 beds, the minimum disk space required for the short-and mid-term storage of image data in disk array is 540 GB. The capacity required for long term storage (at least five years) is 1900 GB. (author)

  4. A microfluidic device to study neuronal and motor responses to acute chemical stimuli in zebrafish.

    Science.gov (United States)

    Candelier, Raphaël; Murmu, Meena Sriti; Romano, Sebastián Alejo; Jouary, Adrien; Debrégeas, Georges; Sumbre, Germán

    2015-07-21

    Zebrafish larva is a unique model for whole-brain functional imaging and to study sensory-motor integration in the vertebrate brain. To take full advantage of this system, one needs to design sensory environments that can mimic the complex spatiotemporal stimulus patterns experienced by the animal in natural conditions. We report on a novel open-ended microfluidic device that delivers pulses of chemical stimuli to agarose-restrained larvae with near-millisecond switching rate and unprecedented spatial and concentration accuracy and reproducibility. In combination with two-photon calcium imaging and recordings of tail movements, we found that stimuli of opposite hedonic values induced different circuit activity patterns. Moreover, by precisely controlling the duration of the stimulus (50-500 ms), we found that the probability of generating a gustatory-induced behavior is encoded by the number of neurons activated. This device may open new ways to dissect the neural-circuit principles underlying chemosensory perception.

  5. Leak detecting and identifying device in a reactor container

    International Nuclear Information System (INIS)

    Ito, Toshiichiro; Tomisawa, Teruaki; Yamada, Minoru.

    1987-01-01

    Purpose: To facilitate early detection and position identification for the leakages in a reactor container, shorten the start-up time for the nuclear power plant and reduce the equipment damages due to leakage. Constitution: Sensor signals from image sensors for obtaining infrared radiation image data are converted into image information and sent to a diagnosis device. While on the other hand, process variant signals from a process computer for obtaining plant status data are sent to a status judging device by which the plant status is judged based on the process variants such as water level, pressure and radioactivity in the reactor. The status judging device retrieves the status image aligned with the present plant status sent from the first memory device and transfers reference image information signals to the diagnosis device as the reference. The diagnosis device compares the present images with the reference images and displays the result of the judgement on CRT. (Yoshino, Y.)

  6. Low dose intranasal oxytocin delivered with Breath Powered device dampens amygdala response to emotional stimuli: A peripheral effect-controlled within-subjects randomized dose-response fMRI trial.

    Science.gov (United States)

    Quintana, Daniel S; Westlye, Lars T; Alnæs, Dag; Rustan, Øyvind G; Kaufmann, Tobias; Smerud, Knut T; Mahmoud, Ramy A; Djupesland, Per G; Andreassen, Ole A

    2016-07-01

    It is unclear if and how exogenous oxytocin (OT) reaches the brain to improve social behavior and cognition and what is the optimal dose for OT response. To better understand the delivery routes of intranasal OT administration to the brain and the dose-response, we compared amygdala response to facial stimuli by means of functional magnetic resonance imaging (fMRI) in four treatment conditions, including two different doses of intranasal OT using a novel Breath Powered device, intravenous (IV) OT, which provided similar concentrations of blood plasma OT, and placebo. We adopted a randomized, double-blind, double-dummy, crossover design, with 16 healthy male adults administering a single-dose of these four treatments. We observed a treatment effect on right amygdala activation during the processing of angry and happy face stimuli, with pairwise comparisons revealing reduced activation after the 8IU low dose intranasal treatment compared to placebo. These data suggest the dampening of amygdala activity in response to emotional stimuli occurs via direct intranasal delivery pathways rather than across the blood-brain barrier via systemically circulating OT. This trial is registered at the U.S. National Institutes of Health clinical trial registry (www.clinicaltrials.gov; NCT01983514) and as EudraCT no. 2013-001608-12. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Software for X-Ray Images Calculation of Hydrogen Compression Device in Megabar Pressure Range

    Science.gov (United States)

    Egorov, Nikolay; Bykov, Alexander; Pavlov, Valery

    2007-06-01

    Software for x-ray images simulation is described. The software is a part of x-ray method used for investigation of an equation of state of hydrogen in a megabar pressure range. A graphical interface that clearly and simply allows users to input data for x-ray image calculation: properties of the studied device, parameters of the x-ray radiation source, parameters of the x-ray radiation recorder, the experiment geometry; to represent the calculation results and efficiently transmit them to other software for processing. The calculation time is minimized. This makes it possible to perform calculations in a dialogue regime. The software is written in ``MATLAB'' system.

  8. Radiation sensitive area detection device and method

    Science.gov (United States)

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

    1991-01-01

    A radiation sensitive area detection device for use in conjunction with an X ray, ultraviolet or other radiation source is provided which comprises a phosphor containing film which releases a stored diffraction pattern image in response to incoming light or other electromagnetic wave. A light source such as a helium-neon laser, an optical fiber capable of directing light from the laser source onto the phosphor film and also capable of channelling the fluoresced light from the phosphor film to an integrating sphere which directs the light to a signal processing means including a light receiving means such as a photomultiplier tube. The signal processing means allows translation of the fluoresced light in order to detect the original pattern caused by the diffraction of the radiation by the original sample. The optical fiber is retained directly in front of the phosphor screen by a thin metal holder which moves up and down across the phosphor screen and which features a replaceable pinhole which allows easy adjustment of the resolution of the light projected onto the phosphor film. The device produces near real time images with high spatial resolution and without the distortion that accompanies prior art devices employing photomultiplier tubes. A method is also provided for carrying out radiation area detection using the device of the invention.

  9. Role of radionuclide imaging for diagnosis of device and prosthetic valve infections

    Science.gov (United States)

    Sarrazin, Jean-François; Philippon, François; Trottier, Mikaël; Tessier, Michel

    2016-01-01

    Cardiovascular implantable electronic device (CIED) infection and prosthetic valve endocarditis (PVE) remain a diagnostic challenge. Cardiac imaging plays an important role in the diagnosis and management of patients with CIED infection or PVE. Over the past few years, cardiac radionuclide imaging has gained a key role in the diagnosis of these patients, and in assessing the need for surgery, mainly in the most difficult cases. Both 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and radiolabelled white blood cell single-photon emission computed tomography/computed tomography (WBC SPECT/CT) have been studied in these situations. In their 2015 guidelines for the management of infective endocarditis, the European Society of Cardiology incorporated cardiac nuclear imaging as part of their diagnostic algorithm for PVE, but not CIED infection since the data were judged insufficient at the moment. This article reviews the actual knowledge and recent studies on the use of 18F-FDG PET/CT and WBC SPECT/CT in the context of CIED infection and PVE, and describes the technical aspects of cardiac radionuclide imaging. It also discusses their accepted and potential indications for the diagnosis and management of CIED infection and PVE, the limitations of these tests, and potential areas of future research. PMID:27721936

  10. Device fabrication, characterization, and thermal neutron detection response of LiZnP and LiZnAs semiconductor devices

    Science.gov (United States)

    Montag, Benjamin W.; Ugorowski, Philip B.; Nelson, Kyle A.; Edwards, Nathaniel S.; McGregor, Douglas S.

    2016-11-01

    Nowotny-Juza compounds continue to be explored as candidates for solid-state neutron detectors. Such a device would have greater efficiency, in a compact form, than present day gas-filled 3He and 10BF3 detectors. The 6Li(n,t)4He reaction yields a total Q-value of 4.78 MeV, larger than 10B, an energy easily identified above background radiations. Hence, devices fabricated from semiconductor compounds having either natural Li (nominally 7.5% 6Li) or enriched 6Li (usually 95% 6Li) as constituent atoms may provide a material for compact high efficiency neutron detectors. Starting material was synthesized by preparing equimolar portions of Li, Zn, and As sealed under vacuum (10-6 Torr) in quartz ampoules lined with boron nitride and subsequently reacted in a compounding furnace [1]. The raw synthesized material indicated the presence high impurity levels (material and electrical property characterizations). A static vacuum sublimation in quartz was performed to help purify the synthesized material [2,3]. Bulk crystalline samples were grown from the purified material [4,5]. Samples were cut using a diamond wire saw, and processed into devices. Bulk resistivity was determined from I-V curve measurements, ranging from 106-1011 Ω cm. Devices were characterized for sensitivity to 5.48 MeV alpha particles, 337 nm laser light, and neutron sensitivity in a thermal neutron diffracted beam at the Kansas State University TRIGA Mark II nuclear reactor. Thermal neutron reaction product charge induction was measured with a LiZnP device, and the reaction product spectral response was observed.

  11. Optically trapped atomic resonant devices for narrow linewidth spectral imaging

    Science.gov (United States)

    Qian, Lipeng

    This thesis focuses on the development of atomic resonant devices for spectroscopic applications. The primary emphasis is on the imaging properties of optically thick atomic resonant fluorescent filters and their applications. In addition, this thesis presents a new concept for producing very narrow linewidth light as from an atomic vapor lamp pumped by a nanosecond pulse system. This research was motivated by application for missile warning system, and presents an innovative approach to a wide angle, ultra narrow linewidth imaging filter using a potassium vapor cell. The approach is to image onto and collect the fluorescent photons emitted from the surface of an optically thick potassium vapor cell, generating a 2 GHz pass-band imaging filter. This linewidth is narrow enough to fall within a Fraunhefer dark zone in the solar spectrum, thus make the detection solar blind. Experiments are conducted to measure the absorption line shape of the potassium resonant filter, the quantum efficiency of the fluorescent behavior, and the resolution of the fluorescent image. Fluorescent images with different spatial frequency components are analyzed by using a discrete Fourier transform, and the imaging capability of the fluorescent filter is described by its Modulation Transfer Function. For the detection of radiation that is spectrally broader than the linewidth of the potassium imaging filter, the fluorescent image is seen to be blurred by diffuse fluorescence from the slightly off resonant photons. To correct this, an ultra-thin potassium imaging filter is developed and characterized. The imaging property of the ultra-thin potassium imaging cell is tested with a potassium seeded flame, yielding a resolution image of ˜ 20 lines per mm. The physics behind the atomic resonant fluorescent filter is radiation trapping. The diffusion process of the resonant photons trapped in the atomic vapor is theoretically described in this thesis. A Monte Carlo method is used to simulate the

  12. Augmented reality with image registration, vision correction and sunlight readability via liquid crystal devices.

    Science.gov (United States)

    Wang, Yu-Jen; Chen, Po-Ju; Liang, Xiao; Lin, Yi-Hsin

    2017-03-27

    Augmented reality (AR), which use computer-aided projected information to augment our sense, has important impact on human life, especially for the elder people. However, there are three major challenges regarding the optical system in the AR system, which are registration, vision correction, and readability under strong ambient light. Here, we solve three challenges simultaneously for the first time using two liquid crystal (LC) lenses and polarizer-free attenuator integrated in optical-see-through AR system. One of the LC lens is used to electrically adjust the position of the projected virtual image which is so-called registration. The other LC lens with larger aperture and polarization independent characteristic is in charge of vision correction, such as myopia and presbyopia. The linearity of lens powers of two LC lenses is also discussed. The readability of virtual images under strong ambient light is solved by electrically switchable transmittance of the LC attenuator originating from light scattering and light absorption. The concept demonstrated in this paper could be further extended to other electro-optical devices as long as the devices exhibit the capability of phase modulations and amplitude modulations.

  13. Collision judgment when using an augmented-vision head-mounted display device.

    Science.gov (United States)

    Luo, Gang; Woods, Russell L; Peli, Eli

    2009-09-01

    A device was developed to provide an expanded visual field to patients with tunnel vision by superimposing minified edge images of the wide scene, in which objects appear closer to the heading direction than they really are. Experiments were conducted in a virtual environment to determine whether users would overestimate collision risks. Given simulated scenes of walking or standing with intention to walk toward a given direction (intended walking) in a shopping mall corridor, participants (12 normally sighted and 7 with tunnel vision) reported whether they would collide with obstacles appearing at different offsets from variable walking paths (or intended directions), with and without the device. The collision envelope (CE), a personal space based on perceived collision judgments, and judgment uncertainty (variability of response) were measured. When the device was used, combinations of two image scales (5x minified and 1:1) and two image types (grayscale or edge images) were tested. Image type did not significantly alter collision judgment (P > 0.7). Compared to the without-device baseline, minification did not significantly change the CE of normally sighted subjects for simulated walking (P = 0.12), but increased CE by 30% for intended walking (P 0.25). For the patients, neither CE nor uncertainty was affected by minification (P > 0.13) in both walking conditions. Baseline CE and uncertainty were greater for patients than normally sighted subjects in simulated walking (P = 0.03), but the two groups were not significantly different in all other conditions. Users did not substantially overestimate collision risk, as the x5 minified images had only limited impact on collision judgments either during walking or before starting to walk.

  14. Cerebral ischemic lesions detected with diffusion-weighted magnetic resonance imaging after carotid artery stenting: Comparison of several anti-embolic protection devices.

    Science.gov (United States)

    Taha, Mahmoud M; Maeda, Masayuki; Sakaida, Hiroshi; Kawaguchi, Kenji; Toma, Naoki; Yamamoto, Akitaka; Hirose, Tomofumi; Miura, Youichi; Fujimoto, Masashi; Matsushima, Satoshi; Taki, Waro

    2009-09-01

    Distal embolism is an important periprocedural technical complication with carotid angioplasty and carotid artery stenting (CAS). We evaluated the safety and efficacy of protection devices used during CAS by detecting new cerebral ischemic lesions using diffusion-weighted magnetic resonance imaging in 95 patients who underwent 98 CAS procedures: 34 using single PercuSurge GuardWire, 31 using double balloon protection, 15 using proximal flow reverse protection devices, 14 using Naviballoon, and 4 using filter anti-embolic devices. Diffusion-weighted imaging was performed preoperatively and postoperatively to evaluate the presence of any new embolic cerebral lesions. Postoperative diffusion-weighted imaging revealed 117 new ischemic lesions. Three patients had new ischemic stroke, two minor and one major, all ipsilateral to the treated carotid artery. The remaining patients had clinically silent ischemia. The incidence of new embolic lesions was lower using the proximal flow reverse protection device than with the double balloon protection (33% vs. 48.4%), but the volume of ipsilateral new ischemic lesions per patient was 136.6 mm(3) vs. 86.9 mm(3), respectively. Neuroprotection with Naviballoon yielded ipsilateral lesions of large volume (86.6 mm(3)) and higher number (5.7 lesions per patient) than using the filter anti-embolic device (34.8 mm(3) and 1 lesion per patient). New cerebral ischemic lesions after neuroprotected CAS are usually silent. The lower incidence of distal ischemia using proximal flow reverse and double balloon protection devices is limited by the larger volume and higher number of ischemic lesions.

  15. Cerebral ischemic lesions detected with diffusion-weighted magnetic resonance imaging after carotid artery stenting. Comparison of several anti-embolic protection devices

    International Nuclear Information System (INIS)

    Taha, M.M.; Maeda, Masayuki; Sakaida, Hiroshi

    2009-01-01

    Distal embolism is an important periprocedural technical complication with carotid angioplasty and carotid artery stenting (CAS). We evaluated the safety and efficacy of protection devices used during CAS by detecting new cerebral ischemic lesions using diffusion-weighted magnetic resonance imaging in 95 patients who underwent 98 CAS procedures: 34 using single PercuSurge GuardWire, 31 using double balloon protection, 15 using proximal flow reverse protection devices, 14 using Naviballoon, and 4 using filter anti-embolic devices. Diffusion-weighted imaging was performed preoperatively and postoperatively to evaluate the presence of any new embolic cerebral lesions. Postoperative diffusion-weighted imaging revealed 117 new ischemic lesions. Three patients had new ischemic stroke, two minor and one major, all ipsilateral to the treated carotid artery. The remaining patients had clinically silent ischemia. The incidence of new embolic lesions was lower using the proximal flow reverse protection device than with the double balloon protection (33% vs. 48.4%), but the volume of ipsilateral new ischemic lesions per patient was 136.6 mm 3 vs. 86.9 mm 3 , respectively. Neuroprotection with Naviballoon yielded ipsilateral lesions of large volume (86.6 mm 3 ) and higher number (5.7 lesions per patient) than using the filter anti-embolic device (34.8 mm 3 and 1 lesion per patient). New cerebral ischemic lesions after neuroprotected CAS are usually silent. The lower incidence of distal ischemia using proximal flow reverse and double balloon protection devices is limited by the larger volume and higher number of ischemic lesions. (author)

  16. A low-cost microwell device for high-resolution imaging of neurite outgrowth in 3D

    Science.gov (United States)

    Ren, Yuan; Mlodzianoski, Michael J.; Cheun Lee, Aih; Huang, Fang; Suter, Daniel M.

    2018-06-01

    Objective. Current neuronal cell culture is mostly performed on two-dimensional (2D) surfaces, which lack many of the important features of the native environment of neurons, including topographical cues, deformable extracellular matrix, and spatial isotropy or anisotropy in three dimensions. Although three-dimensional (3D) cell culture systems provide a more physiologically relevant environment than 2D systems, their popularity is greatly hampered by the lack of easy-to-make-and-use devices. We aim to develop a widely applicable 3D culture procedure to facilitate the transition of neuronal cultures from 2D to 3D. Approach. We made a simple microwell device for 3D neuronal cell culture that is inexpensive, easy to assemble, and fully compatible with commonly used imaging techniques, including super-resolution microscopy. Main results. We developed a novel gel mixture to support 3D neurite regeneration of Aplysia bag cell neurons, a system that has been extensively used for quantitative analysis of growth cone dynamics in 2D. We found that the morphology and growth pattern of bag cell growth cones in 3D culture closely resemble the ones of growth cones observed in vivo. We demonstrated the capability of our device for high-resolution imaging of cytoskeletal and signaling proteins as well as organelles. Significance. Neuronal cell culture has been a valuable tool for neuroscientists to study the behavior of neurons in a controlled environment. Compared to 2D, neurons cultured in 3D retain the majority of their native characteristics, while offering higher accessibility, control, and repeatability. We expect that our microwell device will facilitate a wider adoption of 3D neuronal cultures to study the mechanisms of neurite regeneration.

  17. Efficient use of mobile devices for quantification of pressure injury images.

    Science.gov (United States)

    Garcia-Zapirain, Begonya; Sierra-Sosa, Daniel; Ortiz P, David; Isaza-Monsalve, Mariano; Elmaghraby, Adel

    2018-04-17

    Pressure Injuries are chronic wounds that are formed due to the constriction of the soft tissues against bone prominences. In order to assess these injuries, the medical personnel carry out the evaluation and diagnosis using visual methods and manual measurements, which can be inaccurate and may generate discomfort in the patients. By using segmentation techniques, the Pressure Injuries can be extracted from an image and accurately parameterized, leading to a correct diagnosis. In general, these techniques are based on the solution of differential equations and the involved numerical methods are demanding in terms of computational resources. In previous work, we proposed a technique developed using toroidal parametric equations for image decomposition and segmentation without solving differential equations. In this paper, we present the development of a mobile application useful for the non-contact assessment of Pressure Injuries based on the toroidal decomposition from images. The usage of this technique allows us to achieve an accurate segmentation almost 8 times faster than Active Contours without Edges (ACWE) and Dynamic Contours methods. We describe the techniques and the implementation for Android devices using Python and Kivy. This application allows for the segmentation and parameterization of injuries, obtain relevant information for the diagnosis and tracking the evolution of patient's injuries.

  18. An image compression method for space multispectral time delay and integration charge coupled device camera

    International Nuclear Information System (INIS)

    Li Jin; Jin Long-Xu; Zhang Ran-Feng

    2013-01-01

    Multispectral time delay and integration charge coupled device (TDICCD) image compression requires a low-complexity encoder because it is usually completed on board where the energy and memory are limited. The Consultative Committee for Space Data Systems (CCSDS) has proposed an image data compression (CCSDS-IDC) algorithm which is so far most widely implemented in hardware. However, it cannot reduce spectral redundancy in multispectral images. In this paper, we propose a low-complexity improved CCSDS-IDC (ICCSDS-IDC)-based distributed source coding (DSC) scheme for multispectral TDICCD image consisting of a few bands. Our scheme is based on an ICCSDS-IDC approach that uses a bit plane extractor to parse the differences in the original image and its wavelet transformed coefficient. The output of bit plane extractor will be encoded by a first order entropy coder. Low-density parity-check-based Slepian—Wolf (SW) coder is adopted to implement the DSC strategy. Experimental results on space multispectral TDICCD images show that the proposed scheme significantly outperforms the CCSDS-IDC-based coder in each band

  19. Astronomical Polarimetry with the RIT Polarization Imaging Camera

    Science.gov (United States)

    Vorobiev, Dmitry V.; Ninkov, Zoran; Brock, Neal

    2018-06-01

    In the last decade, imaging polarimeters based on micropolarizer arrays have been developed for use in terrestrial remote sensing and metrology applications. Micropolarizer-based sensors are dramatically smaller and more mechanically robust than other polarimeters with similar spectral response and snapshot capability. To determine the suitability of these new polarimeters for astronomical applications, we developed the RIT Polarization Imaging Camera to investigate the performance of these devices, with a special attention to the low signal-to-noise regime. We characterized the device performance in the lab, by determining the relative throughput, efficiency, and orientation of every pixel, as a function of wavelength. Using the resulting pixel response model, we developed demodulation procedures for aperture photometry and imaging polarimetry observing modes. We found that, using the current calibration, RITPIC is capable of detecting polarization signals as small as ∼0.3%. The relative ease of data collection, calibration, and analysis provided by these sensors suggest than they may become an important tool for a number of astronomical targets.

  20. Mechanical and thermo-mechanical response of a lead-core bearing device subjected to different loading conditions

    Directory of Open Access Journals (Sweden)

    Zhelyazov Todor

    2018-01-01

    Full Text Available The contribution is focused on the numerical modelling, simulation and analysis of a lead-core bearing device for passive seismic isolation. An accurate finite element model of a lead-core bearing device is presented. The model is designed to analyse both mechanical and thermo-mechanical responses of the seismic isolator to different loading conditions. Specifically, the mechanical behaviour in a typical identification test is simulated. The response of the lead-core bearing device to circular sinusoidal paths is analysed. The obtained shear displacement – shear force relationship is compared to experimental data found in literature sources. The hypothesis that heating of the lead-core during cyclic loading affects the degrading phenomena in the bearing device is taken into account. Constitutive laws are defined for each material: lead, rubber and steel. Both predefined constitutive laws (in the used general–purpose finite element code and semi-analytical procedures aimed at a more accurate modelling of the constitutive relations are tested. The results obtained by finite element analysis are to be further used to calibrate a macroscopic model of the lead-core bearing device seen as a single-degree-of-freedom mechanical system.

  1. Spatially pooled contrast responses predict neural and perceptual similarity of naturalistic image categories.

    Directory of Open Access Journals (Sweden)

    Iris I A Groen

    Full Text Available The visual world is complex and continuously changing. Yet, our brain transforms patterns of light falling on our retina into a coherent percept within a few hundred milliseconds. Possibly, low-level neural responses already carry substantial information to facilitate rapid characterization of the visual input. Here, we computationally estimated low-level contrast responses to computer-generated naturalistic images, and tested whether spatial pooling of these responses could predict image similarity at the neural and behavioral level. Using EEG, we show that statistics derived from pooled responses explain a large amount of variance between single-image evoked potentials (ERPs in individual subjects. Dissimilarity analysis on multi-electrode ERPs demonstrated that large differences between images in pooled response statistics are predictive of more dissimilar patterns of evoked activity, whereas images with little difference in statistics give rise to highly similar evoked activity patterns. In a separate behavioral experiment, images with large differences in statistics were judged as different categories, whereas images with little differences were confused. These findings suggest that statistics derived from low-level contrast responses can be extracted in early visual processing and can be relevant for rapid judgment of visual similarity. We compared our results with two other, well- known contrast statistics: Fourier power spectra and higher-order properties of contrast distributions (skewness and kurtosis. Interestingly, whereas these statistics allow for accurate image categorization, they do not predict ERP response patterns or behavioral categorization confusions. These converging computational, neural and behavioral results suggest that statistics of pooled contrast responses contain information that corresponds with perceived visual similarity in a rapid, low-level categorization task.

  2. Spatially Pooled Contrast Responses Predict Neural and Perceptual Similarity of Naturalistic Image Categories

    Science.gov (United States)

    Groen, Iris I. A.; Ghebreab, Sennay; Lamme, Victor A. F.; Scholte, H. Steven

    2012-01-01

    The visual world is complex and continuously changing. Yet, our brain transforms patterns of light falling on our retina into a coherent percept within a few hundred milliseconds. Possibly, low-level neural responses already carry substantial information to facilitate rapid characterization of the visual input. Here, we computationally estimated low-level contrast responses to computer-generated naturalistic images, and tested whether spatial pooling of these responses could predict image similarity at the neural and behavioral level. Using EEG, we show that statistics derived from pooled responses explain a large amount of variance between single-image evoked potentials (ERPs) in individual subjects. Dissimilarity analysis on multi-electrode ERPs demonstrated that large differences between images in pooled response statistics are predictive of more dissimilar patterns of evoked activity, whereas images with little difference in statistics give rise to highly similar evoked activity patterns. In a separate behavioral experiment, images with large differences in statistics were judged as different categories, whereas images with little differences were confused. These findings suggest that statistics derived from low-level contrast responses can be extracted in early visual processing and can be relevant for rapid judgment of visual similarity. We compared our results with two other, well- known contrast statistics: Fourier power spectra and higher-order properties of contrast distributions (skewness and kurtosis). Interestingly, whereas these statistics allow for accurate image categorization, they do not predict ERP response patterns or behavioral categorization confusions. These converging computational, neural and behavioral results suggest that statistics of pooled contrast responses contain information that corresponds with perceived visual similarity in a rapid, low-level categorization task. PMID:23093921

  3. On line portal imaging

    International Nuclear Information System (INIS)

    Munro, Peter

    1996-01-01

    Purpose/Objective: The purpose of this presentation is to examine the various imaging devices that have been developed for portal imaging; describe some of the image registration methods that have been developed to determine geometric errors quantitatively; discuss some of the ways that portal imaging has been incorporated into routine clinical practice; describe quality assurance procedures for these devices, and discuss the use of portal imaging devices for dosimetry applications. Discussion: Verification of patient positioning has always been an important aspect of external beam radiation therapy. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems. The commercial devices can be classified into three categories: T.V. camera-based systems, liquid ionisation chamber systems, and amorphous silicon systems. Many factors influence the quality of images generated by these portal imaging systems. These include factors which are unavoidable (e.g., low subject contrast), factors which depend upon the individual imaging device forming the image (e.g., dose utilisation, spatial resolution) as well as factors which depend upon the characteristics of the linear accelerator irradiating the imaging system (x-ray source size, image magnification). The characteristics of individual imaging systems, such as spatial resolution, temporal response, and quantum utilisation will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same structures on a digitized simulator film. Once the anatomic structures have been registered, any discrepancies in the position of the patient can be identified. However, the task is not nearly as straight-forward as it sounds. One problem

  4. MRI-powered biomedical devices.

    Science.gov (United States)

    Hovet, Sierra; Ren, Hongliang; Xu, Sheng; Wood, Bradford; Tokuda, Junichi; Tse, Zion Tsz Ho

    2017-11-16

    Magnetic resonance imaging (MRI) is beneficial for imaging-guided procedures because it provides higher resolution images and better soft tissue contrast than computed tomography (CT), ultrasound, and X-ray. MRI can be used to streamline diagnostics and treatment because it does not require patients to be repositioned between scans of different areas of the body. It is even possible to use MRI to visualize, power, and control medical devices inside the human body to access remote locations and perform minimally invasive procedures. Therefore, MR conditional medical devices have the potential to improve a wide variety of medical procedures; this potential is explored in terms of practical considerations pertaining to clinical applications and the MRI environment. Recent advancements in this field are introduced with a review of clinically relevant research in the areas of interventional tools, endovascular microbots, and closed-loop controlled MRI robots. Challenges related to technology and clinical feasibility are discussed, including MRI based propulsion and control, navigation of medical devices through the human body, clinical adoptability, and regulatory issues. The development of MRI-powered medical devices is an emerging field, but the potential clinical impact of these devices is promising.

  5. Streamlining machine learning in mobile devices for remote sensing

    Science.gov (United States)

    Coronel, Andrei D.; Estuar, Ma. Regina E.; Garcia, Kyle Kristopher P.; Dela Cruz, Bon Lemuel T.; Torrijos, Jose Emmanuel; Lim, Hadrian Paulo M.; Abu, Patricia Angela R.; Victorino, John Noel C.

    2017-09-01

    Mobile devices have been at the forefront of Intelligent Farming because of its ubiquitous nature. Applications on precision farming have been developed on smartphones to allow small farms to monitor environmental parameters surrounding crops. Mobile devices are used for most of these applications, collecting data to be sent to the cloud for storage, analysis, modeling and visualization. However, with the issue of weak and intermittent connectivity in geographically challenged areas of the Philippines, the solution is to provide analysis on the phone itself. Given this, the farmer gets a real time response after data submission. Though Machine Learning is promising, hardware constraints in mobile devices limit the computational capabilities, making model development on the phone restricted and challenging. This study discusses the development of a Machine Learning based mobile application using OpenCV libraries. The objective is to enable the detection of Fusarium oxysporum cubense (Foc) in juvenile and asymptomatic bananas using images of plant parts and microscopic samples as input. Image datasets of attached, unattached, dorsal, and ventral views of leaves were acquired through sampling protocols. Images of raw and stained specimens from soil surrounding the plant, and sap from the plant resulted to stained and unstained samples respectively. Segmentation and feature extraction techniques were applied to all images. Initial findings show no significant differences among the different feature extraction techniques. For differentiating infected from non-infected leaves, KNN yields highest average accuracy, as opposed to Naive Bayes and SVM. For microscopic images using MSER feature extraction, KNN has been tested as having a better accuracy than SVM or Naive-Bayes.

  6. Triboluminescent tamper-indicating device

    Science.gov (United States)

    Johnston, Roger G.; Garcia, Anthony R. E.

    2002-01-01

    A tamper-indicating device is described. The device has a transparent or translucent cylindrical body that includes triboluminescent material, and an outer opaque layer that prevents ambient light from entering. A chamber in the body holds an undeveloped piece of photographic film bearing an image. The device is assembled from two body members. One of the body members includes a recess for storing film and an optical assembly that can be adjusted to prevent light from passing through the assembly and exposing the film. To use the device with a hasp, the body members are positioned on opposite sides of a hasp, inserted through the hasp, and attached. The optical assembly is then manipulated to allow any light generated from the triboluminescent materials during a tampering activity that damages the device to reach the film and destroy the image on the film.

  7. Fuel assembly inspection device

    International Nuclear Information System (INIS)

    Yaginuma, Yoshitaka

    1998-01-01

    The present invention provides a device suitable to inspect appearance of fuel assemblies by photographing the appearance of fuel assemblies. Namely, the inspection device of the present invention measures bowing of fuel assembly or each of fuel rods or both of them based on the partially photographed images of fuel assembly. In this case, there is disposed a means which flashily projects images in the form of horizontal line from a direction intersecting obliquely relative to a horizontal cross section of the fuel assembly. A first image processing means separates the projected image pictures including projected images and calculates bowing. A second image processing means replaces the projected image pictures of the projected images based on projected images just before and after the photographing. Then, images for the measurement of bowing and images for inspection can be obtained simultaneously. As a result, the time required for the photographing can be shortened, the time for inspection can be shortened and an effect of preventing deterioration of photographing means by radiation rays can be provided. (I.S.)

  8. GA-based optimum design of a shape memory alloy device for seismic response mitigation

    International Nuclear Information System (INIS)

    Ozbulut, O E; Roschke, P N; Lin, P Y; Loh, C H

    2010-01-01

    Damping systems discussed in this work are optimized so that a three-story steel frame structure and its shape memory alloy (SMA) bracing system minimize response metrics due to a custom-tailored earthquake excitation. Multiple-objective numerical optimization that simultaneously minimizes displacements and accelerations of the structure is carried out with a genetic algorithm (GA) in order to optimize SMA bracing elements within the structure. After design of an optimal SMA damping system is complete, full-scale experimental shake table tests are conducted on a large-scale steel frame that is equipped with the optimal SMA devices. A fuzzy inference system is developed from data collected during the testing to simulate the dynamic material response of the SMA bracing subcomponents. Finally, nonlinear analyses of a three-story braced frame are carried out to evaluate the performance of comparable SMA and commonly used steel braces under dynamic loading conditions and to assess the effectiveness of GA-optimized SMA bracing design as compared to alternative designs of SMA braces. It is shown that peak displacement of a structure can be reduced without causing significant acceleration response amplification through a judicious selection of physical characteristics of the SMA devices. Also, SMA devices provide a recentering mechanism for the structure to return to its original position after a seismic event

  9. A delivery device for presentation of tactile stimuli during functional magnetic resonance imaging.

    Science.gov (United States)

    Dykes, Robert W; Miqueé, Aline; Xerri, Christian; Zennou-Azogui, Yoh'i; Rainville, Constant; Dumoulin, André; Marineau, Daniel

    2007-01-30

    We describe a novel stimulus delivery system designed to present tactile stimuli to a subject in the tunnel of a magnetic resonance imaging (MRI) system. Using energy from an air-driven piston to turn a wheel, the device advances a conveyor belt with a pre-determined sequence of stimuli that differ in their spatial features into the tunnel of the MRI. The positioning of one or several stimulus objects in a window near the subject's hand is controlled by a photoelectric device that detects periodic openings in the conveyor belt. Using this electric signal to position each presentation avoids cumulative positioning errors and provides a signal related to the progression of the experiment. We used a series of shapes that differed in their spatial features but the device could carry stimuli with a diversity of shapes and textures. This flexibility allows the experimenter to design a wide variety of psychophysical experiments in the haptic world and possibly to compare and contrast these stimuli with the cognitive treatment of similar stimuli delivered to the other senses. Appropriate experimental design allows separation of motor, sensory and memory storage phases of mental processes.

  10. Electrostatic X-ray image recording device with mesh-base photocathode photoelectron discriminator means

    International Nuclear Information System (INIS)

    1977-01-01

    An electrostatic X-ray image recording device having a pair of spaced electrodes with a gas-filled gap therebetween, and including discrimination means, having a conductive mesh supporting a photocathodic material, positioned in the gas-filled gap between a first electrode having a layer of ultraviolet-emitting fluorescent material and a second electrode having a plastic sheet adjacent thereto for receiving photoelectrons emitted by the photocathodic material and accelerated to the second electrode by an applied field. The photoconductor-mesh element discriminates against fast electrons, produced by direct impingement of X-rays upon the photocathode to substantially reduce secondary electron production and amplification, thereby increasing both the signal-to-noise and contrast ratios. The electrostatic image formed on the plastic sheet is developed by zerographic techniques after exposure. (Auth.)

  11. Wearable Device-Based Gait Recognition Using Angle Embedded Gait Dynamic Images and a Convolutional Neural Network.

    Science.gov (United States)

    Zhao, Yongjia; Zhou, Suiping

    2017-02-28

    The widespread installation of inertial sensors in smartphones and other wearable devices provides a valuable opportunity to identify people by analyzing their gait patterns, for either cooperative or non-cooperative circumstances. However, it is still a challenging task to reliably extract discriminative features for gait recognition with noisy and complex data sequences collected from casually worn wearable devices like smartphones. To cope with this problem, we propose a novel image-based gait recognition approach using the Convolutional Neural Network (CNN) without the need to manually extract discriminative features. The CNN's input image, which is encoded straightforwardly from the inertial sensor data sequences, is called Angle Embedded Gait Dynamic Image (AE-GDI). AE-GDI is a new two-dimensional representation of gait dynamics, which is invariant to rotation and translation. The performance of the proposed approach in gait authentication and gait labeling is evaluated using two datasets: (1) the McGill University dataset, which is collected under realistic conditions; and (2) the Osaka University dataset with the largest number of subjects. Experimental results show that the proposed approach achieves competitive recognition accuracy over existing approaches and provides an effective parametric solution for identification among a large number of subjects by gait patterns.

  12. Wearable Device-Based Gait Recognition Using Angle Embedded Gait Dynamic Images and a Convolutional Neural Network

    Science.gov (United States)

    Zhao, Yongjia; Zhou, Suiping

    2017-01-01

    The widespread installation of inertial sensors in smartphones and other wearable devices provides a valuable opportunity to identify people by analyzing their gait patterns, for either cooperative or non-cooperative circumstances. However, it is still a challenging task to reliably extract discriminative features for gait recognition with noisy and complex data sequences collected from casually worn wearable devices like smartphones. To cope with this problem, we propose a novel image-based gait recognition approach using the Convolutional Neural Network (CNN) without the need to manually extract discriminative features. The CNN’s input image, which is encoded straightforwardly from the inertial sensor data sequences, is called Angle Embedded Gait Dynamic Image (AE-GDI). AE-GDI is a new two-dimensional representation of gait dynamics, which is invariant to rotation and translation. The performance of the proposed approach in gait authentication and gait labeling is evaluated using two datasets: (1) the McGill University dataset, which is collected under realistic conditions; and (2) the Osaka University dataset with the largest number of subjects. Experimental results show that the proposed approach achieves competitive recognition accuracy over existing approaches and provides an effective parametric solution for identification among a large number of subjects by gait patterns. PMID:28264503

  13. Automated vessel shadow segmentation of fovea-centered spectral-domain images from multiple OCT devices

    Science.gov (United States)

    Wu, Jing; Gerendas, Bianca S.; Waldstein, Sebastian M.; Simader, Christian; Schmidt-Erfurth, Ursula

    2014-03-01

    Spectral-domain Optical Coherence Tomography (SD-OCT) is a non-invasive modality for acquiring high reso- lution, three-dimensional (3D) cross sectional volumetric images of the retina and the subretinal layers. SD-OCT also allows the detailed imaging of retinal pathology, aiding clinicians in the diagnosis of sight degrading diseases such as age-related macular degeneration (AMD) and glaucoma.1 Disease diagnosis, assessment, and treatment requires a patient to undergo multiple OCT scans, possibly using different scanning devices, to accurately and precisely gauge disease activity, progression and treatment success. However, the use of OCT imaging devices from different vendors, combined with patient movement may result in poor scan spatial correlation, potentially leading to incorrect patient diagnosis or treatment analysis. Image registration can be used to precisely compare disease states by registering differing 3D scans to one another. In order to align 3D scans from different time- points and vendors using registration, landmarks are required, the most obvious being the retinal vasculature. Presented here is a fully automated cross-vendor method to acquire retina vessel locations for OCT registration from fovea centred 3D SD-OCT scans based on vessel shadows. Noise filtered OCT scans are flattened based on vendor retinal layer segmentation, to extract the retinal pigment epithelium (RPE) layer of the retina. Voxel based layer profile analysis and k-means clustering is used to extract candidate vessel shadow regions from the RPE layer. In conjunction, the extracted RPE layers are combined to generate a projection image featuring all candidate vessel shadows. Image processing methods for vessel segmentation of the OCT constructed projection image are then applied to optimize the accuracy of OCT vessel shadow segmentation through the removal of false positive shadow regions such as those caused by exudates and cysts. Validation of segmented vessel shadows uses

  14. Theoretic simulation for CMOS device on total dose radiation response

    International Nuclear Information System (INIS)

    He Baoping; Zhou Heqin; Guo Hongxia; He Chaohui; Zhou Hui; Luo Yinhong; Zhang Fengqi

    2006-01-01

    Total dose effect is simulated for C4007B, CC4007RH and CC4011 devices at different absorbed dose rate by using linear system theory. When irradiation response and dose are linear, total dose radiation and post-irradiation annealing at room temperature are determined for one random by choosing absorbed dose rate, and total dose effect at other absorbed dose rate can be predicted by using linear system theory. The simulating results agree with the experimental results at different absorbed dose rate. (authors)

  15. Development of a miniature multiple reference optical coherence tomography imaging device

    Science.gov (United States)

    McNamara, Paul M.; O'Riordan, Colm; Collins, Seán.; O'Brien, Peter; Wilson, Carol; Hogan, Josh; Leahy, Martin J.

    2016-03-01

    Multiple reference optical coherence tomography (MR-OCT) is a new technology ideally suited to low-cost, compact OCT imaging. This modality is an extension of time-domain OCT with the addition of a partial mirror in front of the reference mirror. This enables extended, simultaneous depth scanning with the relatively short sweep of a miniature voice coil motor on which the scanning mirror is mounted. Applications of this technology include biometric security, ophthalmology, personal health monitoring and non-destructive testing. This work details early-stage development of the first iteration of a miniature MR-OCT device. This device utilizes a fiber-coupled input from an off-board superluminescent diode (SLD). Typical dimensions of the module are 40 × 57 mm, but future designs are expected to be more compact. Off-the-shelf miniature optical components, voice coil motors and photodetectors are used, with the complexity of design depending on specific applications. The photonic module can be configured as either polarized or non-polarized and can include balanced detection. The photodetectors are directly connected to a printed circuit board under the module containing a transimpedance amplifier with complimentary outputs. The results shown in this work are from the non-polarized device. Assembly of the photonic modules requires extensive planning. In choosing the optical components, Zemax simulations are performed to model the beam characteristics. The physical layout is modeled using Solidworks and each component is placed and aligned via a well-designed alignment procedure involving an active-alignment pick-and-place assembly system.

  16. Initial Experience with a Handheld Device Digital Imaging and Communications in Medicine Viewer: OsiriX Mobile on the iPhone

    OpenAIRE

    Choudhri, Asim F.; Radvany, Martin G.

    2010-01-01

    Medical imaging is commonly used to diagnose many emergent conditions, as well as plan treatment. Digital images can be reviewed on almost any computing platform. Modern mobile phones and handheld devices are portable computing platforms with robust software programming interfaces, powerful processors, and high-resolution displays. OsiriX mobile, a new Digital Imaging and Communications in Medicine viewing program, is available for the iPhone/iPod touch platform. This raises the possibility o...

  17. A mobile device-based imaging spectrometer for environmental monitoring by attaching a lightweight small module to a commercial digital camera.

    Science.gov (United States)

    Cai, Fuhong; Lu, Wen; Shi, Wuxiong; He, Sailing

    2017-11-15

    Spatially-explicit data are essential for remote sensing of ecological phenomena. Lately, recent innovations in mobile device platforms have led to an upsurge in on-site rapid detection. For instance, CMOS chips in smart phones and digital cameras serve as excellent sensors for scientific research. In this paper, a mobile device-based imaging spectrometer module (weighing about 99 g) is developed and equipped on a Single Lens Reflex camera. Utilizing this lightweight module, as well as commonly used photographic equipment, we demonstrate its utility through a series of on-site multispectral imaging, including ocean (or lake) water-color sensing and plant reflectance measurement. Based on the experiments we obtain 3D spectral image cubes, which can be further analyzed for environmental monitoring. Moreover, our system can be applied to many kinds of cameras, e.g., aerial camera and underwater camera. Therefore, any camera can be upgraded to an imaging spectrometer with the help of our miniaturized module. We believe it has the potential to become a versatile tool for on-site investigation into many applications.

  18. Neuroradiology Using Secure Mobile Device Review.

    Science.gov (United States)

    Randhawa, Privia A; Morrish, William; Lysack, John T; Hu, William; Goyal, Mayank; Hill, Michael D

    2016-04-05

    Image review on computer-based workstations has made film-based review outdated. Despite advances in technology, the lack of portability of digital workstations creates an inherent disadvantage. As such, we sought to determine if the quality of image review on a handheld device is adequate for routine clinical use. Six CT/CTA cases and six MR/MRA cases were independently reviewed by three neuroradiologists in varying environments: high and low ambient light using a handheld device and on a traditional imaging workstation in ideal conditions. On first review (using a handheld device in high ambient light), a preliminary diagnosis for each case was made. Upon changes in review conditions, neuroradiologists were asked if any additional features were seen that changed their initial diagnoses. Reviewers were also asked to comment on overall clinical quality and if the handheld display was of acceptable quality for image review. After the initial CT review in high ambient light, additional findings were reported in 2 of 18 instances on subsequent reviews. Similarly, additional findings were identified in 4 of 18 instances after the initial MR review in high ambient lighting. Only one of these six additional findings contributed to the diagnosis made on the initial preliminary review. Use of a handheld device for image review is of adequate diagnostic quality based on image contrast, sharpness of structures, visible artefacts and overall display quality. Although reviewers were comfortable with using this technology, a handheld device with a larger screen may be diagnostically superior.

  19. Research of the system response of neutron double scatter imaging for MLEM reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, M., E-mail: wyj2013@163.com [Northwest Institute of Nuclear Technology, Xi’an 710024 (China); State Key Laboratory of Intense Pulsed Radiation-Simulation and Effect, Xi’an 710024 (China); Peng, B.D.; Sheng, L.; Li, K.N.; Zhang, X.P.; Li, Y.; Li, B.K.; Yuan, Y.; Wang, P.W.; Zhang, X.D.; Li, C.H. [Northwest Institute of Nuclear Technology, Xi’an 710024 (China); State Key Laboratory of Intense Pulsed Radiation-Simulation and Effect, Xi’an 710024 (China)

    2015-03-01

    A Maximum Likelihood image reconstruction technique has been applied to neutron scatter imaging. The response function of the imaging system can be obtained by Monte Carlo simulation, which is very time-consuming if the number of image pixels and particles is large. In this work, to improve time efficiency, an analytical approach based on the probability of neutron interaction and transport in the detector is developed to calculate the system response function. The response function was applied to calculate the relative efficiency of the neutron scatter imaging system as a function of the incident neutron energy. The calculated results agreed with simulations by the MCNP5 software. Then the maximum likelihood expectation maximization (MLEM) reconstruction method with the system response function was used to reconstruct data simulated by Monte Carlo method. The results showed that there was good consistency between the reconstruction position and true position. Compared with back-projection reconstruction, the improvement in image quality was obvious, and the locations could be discerned easily for multiple radiation point sources.

  20. Performance of a malaria microscopy image analysis slide reading device

    Directory of Open Access Journals (Sweden)

    Prescott William R

    2012-05-01

    Full Text Available Abstract Background Viewing Plasmodium in Romanovsky-stained blood has long been considered the gold standard for diagnosis and a cornerstone in management of the disease. This method however, requires a subjective evaluation by trained, experienced diagnosticians and establishing proficiency of diagnosis is fraught with many challenges. Reported here is an evaluation of a diagnostic system (a “device” consisting of a microscope, a scanner, and a computer algorithm that evaluates scanned images of standard Giemsa-stained slides and reports species and parasitaemia. Methods The device was challenged with two independent tests: a 55 slide, expert slide reading test the composition of which has been published by the World Health Organization (“WHO55” test, and a second test in which slides were made from a sample of consenting subjects participating in a malaria incidence survey conducted in Equatorial Guinea (EGMIS test. These subjects’ blood was tested by malaria RDT as well as having the blood smear diagnosis unequivocally determined by a worldwide panel of a minimum of six reference microscopists. Only slides with unequivocal microscopic diagnoses were used for the device challenge, n = 119. Results On the WHO55 test, the device scored a “Level 4” using the WHO published grading scheme. Broken down by more traditional analysis parameters this result was translated to 89% and 70% sensitivity and specificity, respectively. Species were correctly identified in 61% of the slides and the quantification of parasites fell within acceptable range of the validated parasitaemia in 10% of the cases. On the EGMIS test it scored 100% and 94% sensitivity/specificity, with 64% of the species correct and 45% of the parasitaemia within an acceptable range. A pooled analysis of the 174 slides used for both tests resulted in an overall 92% sensitivity and 90% specificity with 61% species and 19% quantifications correct. Conclusions In its

  1. Assessment of flatness and symmetry of megavoltage x-ray beam with an electronic portal imaging device

    CERN Document Server

    Liu, G; Bezak, E

    2002-01-01

    The input/output characteristics of the Wellhofer BIS 710 electronic portal imaging device (EPID) have been investigated to establish its efficacy for periodic quality assurance (QA) applications. Calibration curves have been determined for the energy fluence incident on the detector versus the pixel values. The effect of the charge coupled device (CCD) camera sampling time and beam parameters (such as beam field size, dose rate, photon energy) on the calibration have been investigated for a region of interest (ROI) around the central beam axis. The results demonstrate that the pixel output is a linear function of the incident exposure, as expected for a video-based electronic portal imaging system. The field size effects of the BIS 710 are similar to that of an ion chamber for smaller field sizes up to 10 x 10 cm sup 2. However, for larger field sizes the pixel value increases more rapidly. Furthermore, the system is slightly sensitive to dose rate and is also energy dependent. The BIS 710 has been used in t...

  2. Nuclear Medicine Image Display. Chapter 14

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, H. [Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna (Austria)

    2014-12-15

    The final step in a medical imaging procedure is to display the image(s) on a suitable display system where it is presented to the medical specialist for diagnostic interpretation. The display of hard copy images on X ray film or photographic film has largely been replaced today by soft copy image display systems with cathode ray tube (CRT) or liquid crystal display (LCD) monitors as the image rendering device. Soft copy display requires a high quality display monitor and a certain amount of image processing to optimize the image both with respect to the properties of the display device and to some psychophysiological properties of the human visual system. A soft copy display system, therefore, consists of a display workstation providing some basic image processing functions and the display monitor as the intrinsic display device. Display devices of lower quality may be used during intermediate steps of the acquisition and analysis of a patient study. Display monitors with a quality suitable for diagnostic reading by the specialist medical doctor are called primary devices, also known as diagnostic devices. Monitors with lower quality but good enough to be used for positioning, processing of studies, presentation of images in the wards, etc. are referred to as secondary devices or clinical devices. Nuclear medicine images can be adequately displayed even for diagnostic purposes on secondary devices. However, the increasing use of X ray images on which to report jointly with images from nuclear medicine studies, such as those generated by dual modality imaging, notably by positron emission tomography (PET)/computed tomography (CT) and single photon emission computed tomography (SPECT)/CT, requires display devices capable of visualizing high resolution grey scale images at diagnostic quality, i.e. primary display devices. Both grey scale and colour display devices are used, the latter playing an important role in the display of processed nuclear medicine images and

  3. Nuclear Medicine Image Display. Chapter 14

    International Nuclear Information System (INIS)

    Bergmann, H.

    2014-01-01

    The final step in a medical imaging procedure is to display the image(s) on a suitable display system where it is presented to the medical specialist for diagnostic interpretation. The display of hard copy images on X ray film or photographic film has largely been replaced today by soft copy image display systems with cathode ray tube (CRT) or liquid crystal display (LCD) monitors as the image rendering device. Soft copy display requires a high quality display monitor and a certain amount of image processing to optimize the image both with respect to the properties of the display device and to some psychophysiological properties of the human visual system. A soft copy display system, therefore, consists of a display workstation providing some basic image processing functions and the display monitor as the intrinsic display device. Display devices of lower quality may be used during intermediate steps of the acquisition and analysis of a patient study. Display monitors with a quality suitable for diagnostic reading by the specialist medical doctor are called primary devices, also known as diagnostic devices. Monitors with lower quality but good enough to be used for positioning, processing of studies, presentation of images in the wards, etc. are referred to as secondary devices or clinical devices. Nuclear medicine images can be adequately displayed even for diagnostic purposes on secondary devices. However, the increasing use of X ray images on which to report jointly with images from nuclear medicine studies, such as those generated by dual modality imaging, notably by positron emission tomography (PET)/computed tomography (CT) and single photon emission computed tomography (SPECT)/CT, requires display devices capable of visualizing high resolution grey scale images at diagnostic quality, i.e. primary display devices. Both grey scale and colour display devices are used, the latter playing an important role in the display of processed nuclear medicine images and

  4. Conversion Between Sine Wave and Square Wave Spatial Frequency Response of an Imaging System

    National Research Council Canada - National Science Library

    Nill, Norman B

    2001-01-01

    ...), is a primary image quality metric that is commonly measured with a sine wave target. The FBI certification program for commercial fingerprint capture devices, which MITRE actively supports, has an MTF requirement...

  5. Per-Pixel Coded Exposure for High-Speed and High-Resolution Imaging Using a Digital Micromirror Device Camera

    Directory of Open Access Journals (Sweden)

    Wei Feng

    2016-03-01

    Full Text Available High-speed photography is an important tool for studying rapid physical phenomena. However, low-frame-rate CCD (charge coupled device or CMOS (complementary metal oxide semiconductor camera cannot effectively capture the rapid phenomena with high-speed and high-resolution. In this paper, we incorporate the hardware restrictions of existing image sensors, design the sampling functions, and implement a hardware prototype with a digital micromirror device (DMD camera in which spatial and temporal information can be flexibly modulated. Combined with the optical model of DMD camera, we theoretically analyze the per-pixel coded exposure and propose a three-element median quicksort method to increase the temporal resolution of the imaging system. Theoretically, this approach can rapidly increase the temporal resolution several, or even hundreds, of times without increasing bandwidth requirements of the camera. We demonstrate the effectiveness of our method via extensive examples and achieve 100 fps (frames per second gain in temporal resolution by using a 25 fps camera.

  6. PT-symmetric planar devices for field transformation and imaging

    International Nuclear Information System (INIS)

    Valagiannopoulos, C A; Monticone, F; Alù, A

    2016-01-01

    The powerful tools of transformation optics (TO) allow an effective distortion of a region of space by carefully engineering the material inhomogeneity and anisotropy, and have been successfully applied in recent years to control electromagnetic fields in many different scenarios, e.g., to realize invisibility cloaks and planar lenses. For various field transformations, it is not necessary to use volumetric inhomogeneous materials, and suitably designed ultrathin metasurfaces with tailored spatial or spectral responses may be able to realize similar functionalities within smaller footprints and more robust mechanisms. Here, inspired by the concept of metamaterial TO lenses, we discuss field transformations enabled by parity-time (PT) symmetric metasurfaces, which can emulate negative refraction. We first analyze a simple realization based on homogeneous and local metasurfaces to achieve negative refraction and imaging, and we then extend our results to arbitrary PT-symmetric two-port networks to realize aberration-free planar imaging. (paper)

  7. Gallium 67 imaging in monitoring lymphoma response to treatment

    International Nuclear Information System (INIS)

    Israel, O.; Front, D.; Lam, M.; Ben-Haim, S.; Kleinhaus, U.; Ben-Shachar, M.; Robinson, E.; Kolodny, G.M.

    1988-01-01

    The value of gallium 67 (Ga) imaging in monitoring lymphoma response to treatment was assessed in 25 patients with Ga-avid tumors and compared to body computed tomography (CT), chest radiographs, and palpation of tumor infiltrated peripheral lymph nodes. Ga imaging was negative in 95% (20/21) of the patients who were clinically considered to be in remission and in whom treatment was stopped. The disease did not recur during a follow-up of 12 to 26 months in 15 patients. Six patients developed recurrence of the disease 3 to 12 months after treatment was stopped. In all six patients Ga imaging became positive again at the time of the appearance of active disease. In the group of patients in remission, CT was negative in 57% (11/19), chest x-rays in 55% (6/11) and peripheral lymph nodes were palpated in none of the patients (13/13). In four patients that did not achieve remission after treatment, Ga scans were positive. Ga imaging appears useful in monitoring lymphoma response to treatment. This is probably because Ga imaging monitors tumor cell viability, whereas body CT and chest radiographs show the tumor mass, which may consist of fibrotic or necrotic tissue

  8. Reflective and Non-conscious Responses to Exercise Images.

    Science.gov (United States)

    Cope, Kathryn; Vandelanotte, Corneel; Short, Camille E; Conroy, David E; Rhodes, Ryan E; Jackson, Ben; Dimmock, James A; Rebar, Amanda L

    2017-01-01

    Images portraying exercise are commonly used to promote exercise behavior and to measure automatic associations of exercise (e.g., via implicit association tests). The effectiveness of these promotion efforts and the validity of measurement techniques partially rely on the untested assumption that the images being used are perceived by the general public as portrayals of exercise that is pleasant and motivating. The aim of this study was to investigate how content of images impacted people's automatic and reflective evaluations of exercise images. Participants ( N = 90) completed a response time categorization task (similar to the implicit association test) to capture how automatically people perceived each image as relevant to Exercise or Not exercise . Participants also self-reported their evaluations of the images using visual analog scales with the anchors: Exercise / Not exercise, Does not motivate me to exercise / Motivates me to exercise, Pleasant / Unpleasant , and Energizing/Deactivating . People tended to more strongly automatically associate images with exercise if the images were of an outdoor setting, presented sport (as opposed to active labor or gym-based) activities, and included young (as opposed to middle-aged) adults. People tended to reflectively find images of young adults more motivating and relevant to exercise than images of older adults. The content of exercise images is an often overlooked source of systematic variability that may impact measurement validity and intervention effectiveness.

  9. Reflective and Non-conscious Responses to Exercise Images

    Directory of Open Access Journals (Sweden)

    Kathryn Cope

    2018-01-01

    Full Text Available Images portraying exercise are commonly used to promote exercise behavior and to measure automatic associations of exercise (e.g., via implicit association tests. The effectiveness of these promotion efforts and the validity of measurement techniques partially rely on the untested assumption that the images being used are perceived by the general public as portrayals of exercise that is pleasant and motivating. The aim of this study was to investigate how content of images impacted people's automatic and reflective evaluations of exercise images. Participants (N = 90 completed a response time categorization task (similar to the implicit association test to capture how automatically people perceived each image as relevant to Exercise or Not exercise. Participants also self-reported their evaluations of the images using visual analog scales with the anchors: Exercise/Not exercise, Does not motivate me to exercise/Motivates me to exercise, Pleasant/Unpleasant, and Energizing/Deactivating. People tended to more strongly automatically associate images with exercise if the images were of an outdoor setting, presented sport (as opposed to active labor or gym-based activities, and included young (as opposed to middle-aged adults. People tended to reflectively find images of young adults more motivating and relevant to exercise than images of older adults. The content of exercise images is an often overlooked source of systematic variability that may impact measurement validity and intervention effectiveness.

  10. ACCURACY COMPARISON OF ALGORITHMS FOR DETERMINATION OF IMAGE CENTER COORDINATES IN OPTOELECTRONIC DEVICES

    Directory of Open Access Journals (Sweden)

    N. A. Starasotnikau

    2018-01-01

    Full Text Available Accuracy in determination of coordinates for image having simple shapes is considered as one of important and significant parameters in metrological optoelectronic systems such as autocollimators, stellar sensors, Shack-Hartmann sensors, schemes for geometric calibration of digital cameras for aerial and space imagery, various tracking systems. The paper describes a mathematical model for a measuring stand based on a collimator which projects a test-object onto a photodetector of an optoelectronic device. The mathematical model takes into account characteristic noises for photodetectors: a shot noise of the desired signal (photon and a shot noise of a dark signal, readout and spatial heterogeneity of CCD (charge-coupled device matrix elements. In order to reduce noise effect it is proposed to apply the Wiener filter for smoothing an image and its unambiguous identification and also enter a threshold according to brightness level. The paper contains a comparison of two algorithms for determination of coordinates in accordance with energy gravity center and contour. Sobel, Pruitt, Roberts, Laplacian Gaussian, Canni detectors have been used for determination of the test-object contour. The essence of the algorithm for determination of coordinates lies in search for an image contour in the form of a circle with its subsequent approximation and determination of the image center. An error calculation has been made while determining coordinates of a gravity center for test-objects of various diameters: 5, 10, 20, 30, 40, 50 pixels of a photodetector and also signalto-noise ratio values: 200, 100, 70, 20, 10. Signal-to-noise ratio has been calculated as a difference between maximum image intensity of the test-object and the background which is divided by mean-square deviation of the background. The accuracy for determination of coordinates has been improved by 0.5-1 order in case when there was an increase in a signal-to-noise ratio. Accuracy

  11. Frequency response improvement of a two-port surface acoustic wave device based on epitaxial AlN thin film

    Science.gov (United States)

    Gao, Junning; Hao, Zhibiao; Luo, Yi; Li, Guoqiang

    2018-01-01

    This paper presents an exploration on improving the frequency response of the symmetrical two-port AlN surface acoustic wave (SAW) device, using epitaxial AlN thin film on (0001) sapphire as the piezoelectric substrate. The devices were fabricated by lift-off processes with Ti/Al composite electrodes as interleaved digital transducers (IDT). The impact of DL and the number of the IDT finger pairs on the frequency response was carefully investigated. The overall properties of the device are found to be greatly improved with DL elongation, indicated by the reduced pass band ripple and increased stop band rejection ratio. The rejection increases by 8.3 dB when DL elongates from 15.5λ to 55.5λ and 4.4 dB further accompanying another 50λ elongation. This is because larger DL repels the stray acoustic energy out of the propagation path and provides a cleaner traveling channel for functional SAW, and at the same time restrains electromagnetic feedthrough. It is also found that proper addition of the IDT finger pairs is beneficial for the device response, indicated by the ripple reduction and the insertion loss drop.

  12. Assessing paedophilia based on the haemodynamic brain response to face images

    DEFF Research Database (Denmark)

    Ponseti, Jorge; Granert, Oliver; Van Eimeren, Thilo

    2016-01-01

    that human face processing is tuned to sexual age preferences. This observation prompted us to test whether paedophilia can be inferred based on the haemodynamic brain responses to adult and child faces. METHODS: Twenty-four men sexually attracted to prepubescent boys or girls (paedophiles) and 32 men......OBJECTIVES: Objective assessment of sexual preferences may be of relevance in the treatment and prognosis of child sexual offenders. Previous research has indicated that this can be achieved by pattern classification of brain responses to sexual child and adult images. Our recent research showed...... sexually attracted to men or women (teleiophiles) were exposed to images of child and adult, male and female faces during a functional magnetic resonance imaging (fMRI) session. RESULTS: A cross-validated, automatic pattern classification algorithm of brain responses to facial stimuli yielded four...

  13. Control device for handling device of control rod drive

    International Nuclear Information System (INIS)

    Sasaki, Toshiya

    1998-01-01

    A predetermined aimed portion of control rod drives disposed in a pedestal is photographed, and image data and camera data including the position of the camera are outputted. Edge cut out processing image data are formed based on the outputted image data, and aimed image data and aimed camera data obtained when previously positioning the handling device precisely to a predetermined aimed position are stored. The aimed image data are taken out from the aimed image data file to prepare computer graphic image data, and there is disposed an image superposing processing portion for comparing images based on the computer graphic image data and images based on the image data for edge cut out processing, as well as comparing the aimed camera data and the camera data, and displaying each of them to an image display portion. (I.S.)

  14. Overview of 3-year experience with large-scale electronic portal imaging device-based 3-dimensional transit dosimetry

    NARCIS (Netherlands)

    Mijnheer, Ben J.; González, Patrick; Olaciregui-Ruiz, Igor; Rozendaal, Roel A.; van Herk, Marcel; Mans, Anton

    2015-01-01

    To assess the usefulness of electronic portal imaging device (EPID)-based 3-dimensional (3D) transit dosimetry in a radiation therapy department by analyzing a large set of dose verification results. In our institution, routine in vivo dose verification of all treatments is performed by means of 3D

  15. Spatial mapping of cadmium zinc telluride materials properties and electrical response to improve device yield and performance

    CERN Document Server

    Van Scyoc, J M; Yoon, H; Gilbert, T S; Hilton, N R; Lund, J C; James, R B

    1999-01-01

    Cadmium zinc telluride has experienced tremendous growth in its application to various radiation sensing problems over the last five years. However, there are still issues with yield, particularly of the large volume devices needed for imaging and sensitivity-critical applications. Inhomogeneities of various types and on various length scales currently prevent the fabrication of large devices of high spectral performance. This paper discusses the development of a set of characterization tools for quantifying these inhomogeneities, in order to develop improvement strategies to achieve the desired cadmium zinc telluride crystals for detector fabrication.

  16. Differentiating emotional responses to images and words

    DEFF Research Database (Denmark)

    Jensen, Camilla Birgitte Falk; Petersen, Michael Kai; Larsen, Jakob Eg

    responses are characterized by only small voltage changes that have typically been found in group studies involving multiple trials and large numbers of participants. Hypothesizing that spatial filtering might enhance retrieval, we apply independent component analysis (ICA) to cluster scalp maps and time...... series responses in a single subject based on only a few trials. Comparing our results against previous findings we identify multiple early and late ICA components that are similarly modulated by neutral, pleasant and unpleasant content in both images and words. Suggesting that we might be able to model...

  17. Pharmacogenetics and Imaging-Pharmacogenetics of Antidepressant Response: Towards Translational Strategies.

    Science.gov (United States)

    Lett, Tristram A; Walter, Henrik; Brandl, Eva J

    2016-12-01

    Genetic variation underlies both the response to antidepressant treatment and the occurrence of side effects. Over the past two decades, a number of pharmacogenetic variants, among these the SCL6A4, BDNF, FKBP5, GNB3, GRIK4, and ABCB1 genes, have come to the forefront in this regard. However, small effects sizes, mixed results in independent samples, and conflicting meta-analyses results led to inherent difficulties in the field of pharmacogenetics translating these findings into clinical practice. Nearly all antidepressant pharmacogenetic variants have potentially pleiotropic effects in which they are associated with major depressive disorder, intermediate phenotypes involved in emotional processes, and brain areas affected by antidepressant treatment. The purpose of this article is to provide a comprehensive review of the advances made in the field of pharmacogenetics of antidepressant efficacy and side effects, imaging findings of antidepressant response, and the latest results in the expanding field of imaging-pharmacogenetics studies. We suggest there is mounting evidence that genetic factors exert their impact on treatment response by influencing brain structural and functional changes during antidepressant treatment, and combining neuroimaging and genetic methods may be a more powerful way to detect biological mechanisms of response than either method alone. The most promising imaging-pharmacogenetics findings exist for the SCL6A4 gene, with converging associations with antidepressant response, frontolimbic predictors of affective symptoms, and normalization of frontolimbic activity following antidepressant treatment. More research is required before imaging-pharmacogenetics informed personalized medicine can be applied to antidepressant treatment; nevertheless, inroads have been made towards assessing genetic and neuroanatomical liability and potential clinical application.

  18. Improved cardiovascular diagnostic accuracy by pocket size imaging device in non-cardiologic outpatients: the NaUSiCa (Naples Ultrasound Stethoscope in Cardiology study

    Directory of Open Access Journals (Sweden)

    Schiattarella Pier

    2010-11-01

    Full Text Available Abstract Miniaturization has evolved in the creation of a pocket-size imaging device which can be utilized as an ultrasound stethoscope. This study assessed the additional diagnostic power of pocket size device by both experts operators and trainees in comparison with physical examination and its appropriateness of use in comparison with standard echo machine in a non-cardiologic population. Three hundred four consecutive non cardiologic outpatients underwent a sequential assessment including physical examination, pocket size imaging device and standard Doppler-echo exam. Pocket size device was used by both expert operators and trainees (who received specific training before the beginning of the study. All the operators were requested to give only visual, qualitative insights on specific issues. All standard Doppler-echo exams were performed by expert operators. One hundred two pocket size device exams were performed by experts and two hundred two by trainees. The time duration of the pocket size device exam was 304 ± 117 sec. Diagnosis of cardiac abnormalities was made in 38.2% of cases by physical examination and in 69.7% of cases by physical examination + pocket size device (additional diagnostic power = 31.5%, p In conclusion, pocket size device showed a relevant additional diagnostic value in comparison with physical examination. Sensitivity and specificity were good in experts and suboptimal in trainees. Specificity was particularly influenced by the level of experience. Training programs are needed for pocket size device users.

  19. Discrete Event Simulation Model of the Polaris 2.1 Gamma Ray Imaging Radiation Detection Device

    Science.gov (United States)

    2016-06-01

    release; distribution is unlimited DISCRETE EVENT SIMULATION MODEL OF THE POLARIS 2.1 GAMMA RAY IMAGING RADIATION DETECTION DEVICE by Andres T...ONLY (Leave blank) 2. REPORT DATE June 2016 3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE DISCRETE EVENT SIMULATION MODEL...modeled. The platform, Simkit, was utilized to create a discrete event simulation (DES) model of the Polaris. After carefully constructing the DES

  20. Neutron Imaging with Timepix Coupled Lithium Indium Diselenide

    Directory of Open Access Journals (Sweden)

    Elan Herrera

    2017-12-01

    Full Text Available The material lithium indium diselenide, a single crystal neutron sensitive semiconductor, has demonstrated its capabilities as a high resolution imaging device. The sensor was prepared with a 55 μ m pitch array of gold contacts, designed to couple with the Timepix imaging ASIC. The resulting device was tested at the High Flux Isotope Reactor, demonstrating a response to cold neutrons when enriched in 95% 6 Li. The imaging system performed a series of experiments resulting in a <200 μ m resolution limit with the Paul Scherrer Institute (PSI Siemens star mask and a feature resolution of 34 μ m with a knife-edge test. Furthermore, the system was able to resolve the University of Tennessee logo inscribed into a 3D printed 1 cm 3 plastic block. This technology marks the application of high resolution neutron imaging using a direct readout semiconductor.

  1. Evaluation of early imaging response criteria in glioblastoma multiforme

    International Nuclear Information System (INIS)

    Gladwish, Adam; Koh, Eng-Siew; Hoisak, Jeremy; Lockwood, Gina; Millar, Barbara-Ann; Mason, Warren; Yu, Eugene; Laperriere, Normand J; Ménard, Cynthia

    2011-01-01

    Early and accurate prediction of response to cancer treatment through imaging criteria is particularly important in rapidly progressive malignancies such as Glioblastoma Multiforme (GBM). We sought to assess the predictive value of structural imaging response criteria one month after concurrent chemotherapy and radiotherapy (RT) in patients with GBM. Thirty patients were enrolled from 2005 to 2007 (median follow-up 22 months). Tumor volumes were delineated at the boundary of abnormal contrast enhancement on T1-weighted images prior to and 1 month after RT. Clinical Progression [CP] occurred when clinical and/or radiological events led to a change in chemotherapy management. Early Radiologic Progression [ERP] was defined as the qualitative interpretation of radiological progression one month post-RT. Patients with ERP were determined pseudoprogressors if clinically stable for ≥6 months. Receiver-operator characteristics were calculated for RECIST and MacDonald criteria, along with alternative thresholds against 1 year CP-free survival and 2 year overall survival (OS). 13 patients (52%) were found to have ERP, of whom 5 (38.5%) were pseudoprogressors. Patients with ERP had a lower median OS (11.2 mo) than those without (not reached) (p < 0.001). True progressors fared worse than pseudoprogressors (median survival 7.2 mo vs. 19.0 mo, p < 0.001). Volume thresholds performed slightly better compared to area and diameter thresholds in ROC analysis. Responses of > 25% in volume or > 15% in area were most predictive of OS. We show that while a subjective interpretation of early radiological progression from baseline is generally associated with poor outcome, true progressors cannot be distinguished from pseudoprogressors. In contrast, the magnitude of early imaging volumetric response may be a predictive and quantitative metric of favorable outcome

  2. Latest developments in image processing for the next generation of devices with a view on DEMO

    International Nuclear Information System (INIS)

    Murari, A.; Vega, J.; Mazon, D.; Arena, P.; Craciunescu, T.; Gabellieri, L.; Gelfusa, M.; Pacella, D.; Palazzo, S.; Romano, A.

    2012-01-01

    Highlights: ► Pattern recognition methods have been successfully applied to retrieve frames in massime databases. ► The technology of Cellular Nonlinear Networks (CNNs) has been upgraded to solve space variant problem. ► The CNNs have then been successfully applied to various tasks, from the real time hot spot detection to the automatic identification of instabilities. ► The method of the optical flow permits to derive information about the speed of the objects moving in the frames of a single camera. ► Since the next generation of devices will emit a lot of SXR radiation, also from the edge, new technologies (Gas Electron Multiplier detectors and policapillary lenses) are being developed to perform imaging over this region of the spectrum for a global view of the entire plasma column. - Abstract: In magnetic confinement fusion devices the use of cameras, both visible and infrared, has increased very significantly in the last years. The large amount of data (in the range of tens of Gbytes per shot) and the difficulty of the analysis tasks (ambiguity, ill posed problems, etc.), require new solutions. The technology of Cellular Nonlinear Networks (CNNs) has been successfully applied to various tasks, from the real time hot spot detection to the automatic identification of instabilities. The accuracy obtained is comparable to the one of more traditional serial algorithms but the CCNs guarantee deterministic computational times independently from the image contents. Moreover the latest developments have allowed obtaining these results also in the case of space variant image analysis, without compromising the computational speed (of the order of ten thousand frames per second). The method of the optical flow permits to derive information about the speed of the objects moving in the frames of a single camera. The results of previous applications have been so successful that the approach has been extended to videos in compressed format (MPEG) to reduce the

  3. An automated device for the digitization and 3D modelling of insects, combining extended-depth-of-field and all-side multi-view imaging

    Directory of Open Access Journals (Sweden)

    Bernhard Ströbel

    2018-05-01

    Full Text Available Digitization of natural history collections is a major challenge in archiving biodiversity. In recent years, several approaches have emerged, allowing either automated digitization, extended depth of field (EDOF or multi-view imaging of insects. Here, we present DISC3D: a new digitization device for pinned insects and other small objects that combines all these aspects. A PC and a microcontroller board control the device. It features a sample holder on a motorized two-axis gimbal, allowing the specimens to be imaged from virtually any view. Ambient, mostly reflection-free illumination is ascertained by two LED-stripes circularly installed in two hemispherical white-coated domes (front-light and back-light. The device is equipped with an industrial camera and a compact macro lens, mounted on a motorized macro rail. EDOF images are calculated from an image stack using a novel calibrated scaling algorithm that meets the requirements of the pinhole camera model (a unique central perspective. The images can be used to generate a calibrated and real color texturized 3Dmodel by ‘structure from motion’ with a visibility consistent mesh generation. Such models are ideal for obtaining morphometric measurement data in 1D, 2D and 3D, thereby opening new opportunities for trait-based research in taxonomy, phylogeny, eco-physiology, and functional ecology.

  4. Generalized internal multiple imaging

    KAUST Repository

    Zuberi, Mohammad Akbar Hosain

    2014-12-04

    Various examples are provided for generalized internal multiple imaging (GIMI). In one example, among others, a method includes generating a higher order internal multiple image using a background Green\\'s function and rendering the higher order internal multiple image for presentation. In another example, a system includes a computing device and a generalized internal multiple imaging (GIMI) application executable in the computing device. The GIMI application includes logic that generates a higher order internal multiple image using a background Green\\'s function and logic that renders the higher order internal multiple image for display on a display device. In another example, a non-transitory computer readable medium has a program executable by processing circuitry that generates a higher order internal multiple image using a background Green\\'s function and renders the higher order internal multiple image for display on a display device.

  5. Generalized internal multiple imaging

    KAUST Repository

    Zuberi, Mohammad Akbar Hosain; Alkhalifah, Tariq

    2014-01-01

    Various examples are provided for generalized internal multiple imaging (GIMI). In one example, among others, a method includes generating a higher order internal multiple image using a background Green's function and rendering the higher order internal multiple image for presentation. In another example, a system includes a computing device and a generalized internal multiple imaging (GIMI) application executable in the computing device. The GIMI application includes logic that generates a higher order internal multiple image using a background Green's function and logic that renders the higher order internal multiple image for display on a display device. In another example, a non-transitory computer readable medium has a program executable by processing circuitry that generates a higher order internal multiple image using a background Green's function and renders the higher order internal multiple image for display on a display device.

  6. Fast imaging diagnostics on the C-2U advanced beam-driven field-reversed configuration device

    Energy Technology Data Exchange (ETDEWEB)

    Granstedt, E. M., E-mail: egranstedt@trialphaenergy.com; Petrov, P.; Knapp, K.; Cordero, M.; Patel, V. [Tri Alpha Energy, P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States)

    2016-11-15

    The C-2U device employed neutral beam injection, end-biasing, and various particle fueling techniques to sustain a Field-Reversed Configuration (FRC) plasma. As part of the diagnostic suite, two fast imaging instruments with radial and nearly axial plasma views were developed using a common camera platform. To achieve the necessary viewing geometry, imaging lenses were mounted behind re-entrant viewports attached to welded bellows. During gettering, the vacuum optics were retracted and isolated behind a gate valve permitting their removal if cleaning was necessary. The axial view incorporated a stainless-steel mirror in a protective cap assembly attached to the vacuum-side of the viewport. For each system, a custom lens-based, high-throughput optical periscope was designed to relay the plasma image about half a meter to a high-speed camera. Each instrument also contained a remote-controlled filter wheel, set between shots to isolate a particular hydrogen or impurity emission line. The design of the camera platform, imaging performance, and sample data for each view is presented.

  7. Functional Store Image and Corporate Social Responsibility Image: A Congruity Analysis on Store Loyalty

    OpenAIRE

    Jamaliah Mohd. Yusof; Rosidah Musa; Sofiah Abd. Rahman

    2011-01-01

    With previous studies that examined the importance of functional store image and CSR, this study is aimed at examining their effects in the self-congruity model in influencing store loyalty. In particular, this study developed and tested a structural model in the context of retailing industry on the self-congruity theory. Whilst much of the self-congruity studies have incorporated functional store image, there has been lack of studies that examined social responsibility i...

  8. Emergency CT brain: preliminary interpretation with a tablet device: image quality and diagnostic performance of the Apple iPad.

    LENUS (Irish Health Repository)

    Mc Laughlin, Patrick

    2012-04-01

    Tablet devices have recently been used in radiological image interpretation because they have a display resolution comparable to desktop LCD monitors. We identified a need to examine tablet display performance prior to their use in preliminary interpretation of radiological images. We compared the spatial and contrast resolution of a commercially available tablet display with a diagnostic grade 2 megapixel monochrome LCD using a contrast detail phantom. We also recorded reporting discrepancies, using the ACR RADPEER system, between preliminary interpretation of 100 emergency CT brain examinations on the tablet display and formal review on a diagnostic LCD. The iPad display performed inferiorly to the diagnostic monochrome display without the ability to zoom. When the software zoom function was enabled on the tablet device, comparable contrast detail phantom scores of 163 vs 165 points were achieved. No reporting discrepancies were encountered during the interpretation of 43 normal examinations and five cases of acute intracranial hemorrhage. There were seven RADPEER2 (understandable) misses when using the iPad display and 12 with the diagnostic LCD. Use of software zoom in the tablet device improved its contrast detail phantom score. The tablet allowed satisfactory identification of acute CT brain findings, but additional research will be required to examine the cause of "understandable" reporting discrepancies that occur when using tablet devices.

  9. Feasibility study of a dual detector configuration concept for simultaneous megavoltage imaging and dose verification in radiotherapy

    International Nuclear Information System (INIS)

    Deshpande, Shrikant; McNamara, Aimee L.; Holloway, Lois; Metcalfe, Peter; Vial, Philip

    2015-01-01

    Purpose: To test the feasibility of a dual detector concept for comprehensive verification of external beam radiotherapy. Specifically, the authors test the hypothesis that a portal imaging device coupled to a 2D dosimeter provides a system capable of simultaneous imaging and dose verification, and that the presence of each device does not significantly detract from the performance of the other. Methods: The dual detector configuration comprised of a standard radiotherapy electronic portal imaging device (EPID) positioned directly on top of an ionization-chamber array (ICA) with 2 cm solid water buildup material (between EPID and ICA) and 5 cm solid backscatter material. The dose response characteristics of the ICA and the imaging performance of the EPID in the dual detector configuration were compared to the performance in their respective reference clinical configurations. The reference clinical configurations were 6 cm solid water buildup material, an ICA, and 5 cm solid water backscatter material as the reference dosimetry configuration, and an EPID with no additional buildup or solid backscatter material as the reference imaging configuration. The dose response of the ICA was evaluated by measuring the detector’s response with respect to off-axis position, field size, and transit object thickness. Clinical dosimetry performance was evaluated by measuring a range of clinical intensity-modulated radiation therapy (IMRT) beams in transit and nontransit geometries. The imaging performance of the EPID was evaluated quantitatively by measuring the contrast-to-noise ratio (CNR) and spatial resolution. Images of an anthropomorphic phantom were also used for qualitative assessment. Results: The measured off-axis and field size response with the ICA in both transit and nontransit geometries for both dual detector configuration and reference dosimetry configuration agreed to within 1%. Transit dose response as a function of object thickness agreed to within 0.5%. All

  10. Initial experience with a handheld device digital imaging and communications in medicine viewer: OsiriX mobile on the iPhone.

    Science.gov (United States)

    Choudhri, Asim F; Radvany, Martin G

    2011-04-01

    Medical imaging is commonly used to diagnose many emergent conditions, as well as plan treatment. Digital images can be reviewed on almost any computing platform. Modern mobile phones and handheld devices are portable computing platforms with robust software programming interfaces, powerful processors, and high-resolution displays. OsiriX mobile, a new Digital Imaging and Communications in Medicine viewing program, is available for the iPhone/iPod touch platform. This raises the possibility of mobile review of diagnostic medical images to expedite diagnosis and treatment planning using a commercial off the shelf solution, facilitating communication among radiologists and referring clinicians.

  11. A pH-responsive supramolecular polymer gel as an enteric elastomer for use in gastric devices

    Science.gov (United States)

    Zhang, Shiyi; Bellinger, Andrew M.; Glettig, Dean L.; Barman, Ross; Lee, Young-Ah Lucy; Zhu, Jiahua; Cleveland, Cody; Montgomery, Veronica A.; Gu, Li; Nash, Landon D.; Maitland, Duncan J.; Langer, Robert; Traverso, Giovanni

    2015-10-01

    Devices resident in the stomach--used for a variety of clinical applications including nutritional modulation for bariatrics, ingestible electronics for diagnosis and monitoring, and gastric-retentive dosage forms for prolonged drug delivery--typically incorporate elastic polymers to compress the devices during delivery through the oesophagus and other narrow orifices in the digestive system. However, in the event of accidental device fracture or migration, the non-degradable nature of these materials risks intestinal obstruction. Here, we show that an elastic, pH-responsive supramolecular gel remains stable and elastic in the acidic environment of the stomach but can be dissolved in the neutral-pH environment of the small and large intestines. In a large animal model, prototype devices with these materials as the key component demonstrated prolonged gastric retention and safe passage. These enteric elastomers should increase the safety profile for a wide range of gastric-retentive devices.

  12. Investigation of the degradation mechanisms of a variety of organic photovoltaic devices by combination of imaging techniques—the ISOS-3 inter-laboratory collaboration

    DEFF Research Database (Denmark)

    Rösch, Roland; Tanenbaum, David; Jørgensen, Mikkel

    2012-01-01

    The investigation of degradation of seven distinct sets (with a number of individual cells of n $ 12) of state of the art organic photovoltaic devices prepared by leading research laboratories with a combination of imaging methods is reported. All devices have been shipped to and degraded at Risø...

  13. Magnetic Resonance Flow Velocity and Temperature Mapping of a Shape Memory Polymer Foam Device

    Energy Technology Data Exchange (ETDEWEB)

    Small IV, W; Gjersing, E; Herberg, J L; Wilson, T S; Maitland, D J

    2008-10-29

    Interventional medical devices based on thermally responsive shape memory polymer (SMP) are under development to treat stroke victims. The goals of these catheter-delivered devices include re-establishing blood flow in occluded arteries and preventing aneurysm rupture. Because these devices alter the hemodynamics and dissipate thermal energy during the therapeutic procedure, a first step in the device development process is to investigate fluid velocity and temperature changes following device deployment. A laser-heated SMP foam device was deployed in a simplified in vitro vascular model. Magnetic resonance imaging (MRI) techniques were used to assess the fluid dynamics and thermal changes associated with device deployment. Spatial maps of the steady-state fluid velocity and temperature change inside and outside the laser-heated SMP foam device were acquired. Though non-physiological conditions were used in this initial study, the utility of MRI in the development of a thermally-activated SMP foam device has been demonstrated.

  14. Device for verification of seals by optical fibers

    International Nuclear Information System (INIS)

    Neuilly, M.; Guitaud, M.H.; Dufour, J.L.

    1993-01-01

    The seal is built around an optical fiber with a verification device. This device is made of a lighting source and photographic means supported by a rotating assembly which allow to take an image of each optical fiber end. These images are compared with reference images taken just after the sealing. (A.B.). 5 refs., 6 figs

  15. THERMAL IMAGING OF Si, GaAs AND GaN -BASED DEVICES WITHIN THE MICROTHERM PROJECT

    OpenAIRE

    Pavageau , S.; Tessier , G.; Filloy , C.; Jerosolimski , G.; Fournier , D.; Polignano , M.-L.; Mica , I.; Cassette , S.; Aubry , R.; Durand , O.

    2005-01-01

    Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/5920); International audience; Within the european project Microtherm, we have developed a CCD-based thermoreflectance system which delivers thermal images of working integrated circuits with high spatial and thermal resolutions (down to 350 nm and 0.1 K respectively). We illustrate the performances of this set-up on several classes of semiconductor devices including high power transistors and transistor ar...

  16. Stab injury and device implantation within the brain results in inversely multiphasic neuroinflammatory and neurodegenerative responses

    Science.gov (United States)

    Potter, Kelsey A.; Buck, Amy C.; Self, Wade K.; Capadona, Jeffrey R.

    2012-08-01

    An estimated 25 million people in the US alone rely on implanted medical devices, ˜2.5 million implanted within the nervous system. Even though many devices perform adequately for years, the host response to medical devices often severely limits tissue integration and long-term performance. This host response is believed to be particularly limiting in the case of intracortical microelectrodes, where it has been shown that glial cell encapsulation and localized neuronal cell loss accompany intracortical microelectrode implantation. Since neuronal ensembles must be within ˜50 µm of the electrode to obtain neuronal spikes and local field potentials, developing a better understanding of the molecular and cellular environment at the device-tissue interface has been the subject of significant research. Unfortunately, immunohistochemical studies of scar maturation in correlation to device function have been inconclusive. Therefore, here we present a detailed quantitative study of the cellular events and the stability of the blood-brain barrier (BBB) following intracortical microelectrode implantation and cortical stab injury in a chronic survival model. We found two distinctly inverse multiphasic profiles for neuronal survival in device-implanted tissue compared to stab-injured animals. For chronically implanted animals, we observed a biphasic paradigm between blood-derived/trauma-induced and CNS-derived inflammatory markers driving neurodegeneration at the interface. In contrast, stab injured animals demonstrated a CNS-mediated neurodegenerative environment. Collectively these data provide valuable insight to the possibility of multiple roles of chronic neuroinflammatory events on BBB disruption and localized neurodegeneration, while also suggesting the importance to consider multiphasic neuroinflammatory kinetics in the design of therapeutic strategies for stabilizing neural interfaces.

  17. Combining the Converse Humidity/Resistance Response Behaviors of RGO Films for Flexible Logic Devices

    KAUST Repository

    Tai, Yanlong

    2017-03-23

    Carbon nanomaterials have excellent humidity sensing performance. Here, we demonstrate that reduced-graphene-oxide- (rGO) based conductive films with different thermal reduction times have gradient and invertible humidity/electrical resistance responses: rGO films (< 11 h, negative response, regarded as a signal of “0”), rGO films (around 11-13 h, balance point) and rGO films (> 13 h, negative response, regarded as a signal of “1”). We propose a new mechanism that describes a “scale”-like model for rGO films to explain these behaviors based on contributions from Ohm-contact resistance and capacitive reactance at interplate junctions, and intrinsic resistances of the nanoplates, respectively. This mechanism is accordingly validated via a series of experiments and electrical impedance spectroscopies, which complement more classical models based on proton conductivity. To explore the practical applications of the converse humidity/resistance responses, three simple flexible logic devices were developed, i) a rGO pattern for humidity-insensitive conductive film, which has the potential to greatly improve the stability of carbon-based electrical device to humidity; ii) a Janus pattern of rGO films for gesture recognition, which is very useful to human/machine interactions; iii) a sandwich pattern of rGO films for 3-dimensional (3D) noncontact sensing, which will be complementary to existing 3D touch technique.

  18. High Tc superconducting nonlinear inductance and quick response magnetic sensor devices

    International Nuclear Information System (INIS)

    Uchiyama, T.; Mohri, K.; Ozeki, A.; Shibata, T.

    1990-01-01

    A flux penetration model considering the demagnetizing effect is presented in order to analyze the nonlinear inductance characteristics for HTcSC. Various quick response magnetic devices such as modulators, magnetic switches and magnetic sensors were constructed. The magnetizing frequency can be set up more than 10 MHz which is difficult to achieve with the conventional ferromagnetic bulk cores. The cut-off frequency of 1.6 MHz was obtained for the sensors using the HTcSC cores at a magnetizing frequency of 11.5 MHz

  19. Spike-Timing Dependent Plasticity in Unipolar Silicon Oxide RRAM Devices.

    Science.gov (United States)

    Zarudnyi, Konstantin; Mehonic, Adnan; Montesi, Luca; Buckwell, Mark; Hudziak, Stephen; Kenyon, Anthony J

    2018-01-01

    Resistance switching, or Resistive RAM (RRAM) devices show considerable potential for application in hardware spiking neural networks (neuro-inspired computing) by mimicking some of the behavior of biological synapses, and hence enabling non-von Neumann computer architectures. Spike-timing dependent plasticity (STDP) is one such behavior, and one example of several classes of plasticity that are being examined with the aim of finding suitable algorithms for application in many computing tasks such as coincidence detection, classification and image recognition. In previous work we have demonstrated that the neuromorphic capabilities of silicon-rich silicon oxide (SiO x ) resistance switching devices extend beyond plasticity to include thresholding, spiking, and integration. We previously demonstrated such behaviors in devices operated in the unipolar mode, opening up the question of whether we could add plasticity to the list of features exhibited by our devices. Here we demonstrate clear STDP in unipolar devices. Significantly, we show that the response of our devices is broadly similar to that of biological synapses. This work further reinforces the potential of simple two-terminal RRAM devices to mimic neuronal functionality in hardware spiking neural networks.

  20. Four-dimensional dose reconstruction through in vivo phase matching of cine images of electronic portal imaging device.

    Science.gov (United States)

    Yoon, Jihyung; Jung, Jae Won; Kim, Jong Oh; Yi, Byong Yong; Yeo, Inhwan

    2016-07-01

    A method is proposed to reconstruct a four-dimensional (4D) dose distribution using phase matching of measured cine images to precalculated images of electronic portal imaging device (EPID). (1) A phantom, designed to simulate a tumor in lung (a polystyrene block with a 3 cm diameter embedded in cork), was placed on a sinusoidally moving platform with an amplitude of 1 cm and a period of 4 s. Ten-phase 4D computed tomography (CT) images of the phantom were acquired. A planning target volume (PTV) was created by adding a margin of 1 cm around the internal target volume of the tumor. (2) Three beams were designed, which included a static beam, a theoretical dynamic beam, and a planning-optimized dynamic beam (PODB). While the theoretical beam was made by manually programming a simplistic sliding leaf motion, the planning-optimized beam was obtained from treatment planning. From the three beams, three-dimensional (3D) doses on the phantom were calculated; 4D dose was calculated by means of the ten phase images (integrated over phases afterward); serving as "reference" images, phase-specific EPID dose images under the lung phantom were also calculated for each of the ten phases. (3) Cine EPID images were acquired while the beams were irradiated to the moving phantom. (4) Each cine image was phase-matched to a phase-specific CT image at which common irradiation occurred by intercomparing the cine image with the reference images. (5) Each cine image was used to reconstruct dose in the phase-matched CT image, and the reconstructed doses were summed over all phases. (6) The summation was compared with forwardly calculated 4D and 3D dose distributions. Accounting for realistic situations, intratreatment breathing irregularity was simulated by assuming an amplitude of 0.5 cm for the phantom during a portion of breathing trace in which the phase matching could not be performed. Intertreatment breathing irregularity between the time of treatment and the time of planning CT was

  1. Four-dimensional dose reconstruction through in vivo phase matching of cine images of electronic portal imaging device

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jihyung; Jung, Jae Won, E-mail: jungj@ecu.edu [Department of Physics, East Carolina University, Greenville, North Carolina 27858 (United States); Kim, Jong Oh [Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania 15232 (United States); Yi, Byong Yong [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201 (United States); Yeo, Inhwan [Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, California 92354 (United States)

    2016-07-15

    Purpose: A method is proposed to reconstruct a four-dimensional (4D) dose distribution using phase matching of measured cine images to precalculated images of electronic portal imaging device (EPID). Methods: (1) A phantom, designed to simulate a tumor in lung (a polystyrene block with a 3 cm diameter embedded in cork), was placed on a sinusoidally moving platform with an amplitude of 1 cm and a period of 4 s. Ten-phase 4D computed tomography (CT) images of the phantom were acquired. A planning target volume (PTV) was created by adding a margin of 1 cm around the internal target volume of the tumor. (2) Three beams were designed, which included a static beam, a theoretical dynamic beam, and a planning-optimized dynamic beam (PODB). While the theoretical beam was made by manually programming a simplistic sliding leaf motion, the planning-optimized beam was obtained from treatment planning. From the three beams, three-dimensional (3D) doses on the phantom were calculated; 4D dose was calculated by means of the ten phase images (integrated over phases afterward); serving as “reference” images, phase-specific EPID dose images under the lung phantom were also calculated for each of the ten phases. (3) Cine EPID images were acquired while the beams were irradiated to the moving phantom. (4) Each cine image was phase-matched to a phase-specific CT image at which common irradiation occurred by intercomparing the cine image with the reference images. (5) Each cine image was used to reconstruct dose in the phase-matched CT image, and the reconstructed doses were summed over all phases. (6) The summation was compared with forwardly calculated 4D and 3D dose distributions. Accounting for realistic situations, intratreatment breathing irregularity was simulated by assuming an amplitude of 0.5 cm for the phantom during a portion of breathing trace in which the phase matching could not be performed. Intertreatment breathing irregularity between the time of treatment and the

  2. Development of targeted STORM for super resolution imaging of biological samples using digital micro-mirror device

    Science.gov (United States)

    Valiya Peedikakkal, Liyana; Steventon, Victoria; Furley, Andrew; Cadby, Ashley J.

    2017-12-01

    We demonstrate a simple illumination system based on a digital mirror device which allows for fine control over the power and pattern of illumination. We apply this to localization microscopy (LM), specifically stochastic optical reconstruction microscopy (STORM). Using this targeted STORM, we were able to image a selected area of a labelled cell without causing photo-damage to the surrounding areas of the cell.

  3. Angular sensitivity of modeled scientific silicon charge-coupled devices to initial electron direction

    Energy Technology Data Exchange (ETDEWEB)

    Plimley, Brian, E-mail: brian.plimley@gmail.com [Nuclear Engineering Department, University of California, Berkeley, CA (United States); Coffer, Amy; Zhang, Yigong [Nuclear Engineering Department, University of California, Berkeley, CA (United States); Vetter, Kai [Nuclear Engineering Department, University of California, Berkeley, CA (United States); Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2016-08-11

    Previously, scientific silicon charge-coupled devices (CCDs) with 10.5-μm pixel pitch and a thick (650 μm), fully depleted bulk have been used to measure gamma-ray-induced fast electrons and demonstrate electron track Compton imaging. A model of the response of this CCD was also developed and benchmarked to experiment using Monte Carlo electron tracks. We now examine the trade-off in pixel pitch and electronic noise. We extend our CCD response model to different pixel pitch and readout noise per pixel, including pixel pitch of 2.5 μm, 5 μm, 10.5 μm, 20 μm, and 40 μm, and readout noise from 0 eV/pixel to 2 keV/pixel for 10.5 μm pixel pitch. The CCD images generated by this model using simulated electron tracks are processed by our trajectory reconstruction algorithm. The performance of the reconstruction algorithm defines the expected angular sensitivity as a function of electron energy, CCD pixel pitch, and readout noise per pixel. Results show that our existing pixel pitch of 10.5 μm is near optimal for our approach, because smaller pixels add little new information but are subject to greater statistical noise. In addition, we measured the readout noise per pixel for two different device temperatures in order to estimate the effect of temperature on the reconstruction algorithm performance, although the readout is not optimized for higher temperatures. The noise in our device at 240 K increases the FWHM of angular measurement error by no more than a factor of 2, from 26° to 49° FWHM for electrons between 425 keV and 480 keV. Therefore, a CCD could be used for electron-track-based imaging in a Peltier-cooled device.

  4. Movement monitoring device

    International Nuclear Information System (INIS)

    Ichikawa, Takashi; Yoneda, Yasuaki; Hanatsumi, Masaharu.

    1997-01-01

    The present invention provides a device suitable to accurate recognition for the moving state of reactor core fuels as an object to be monitored in a nuclear power plant. Namely, the device of the present invention prepares each of scheduled paths for the movement of the object to be monitored and executed moving paths along with the movement based on the information of the movement obtained from scheduled information for the movement of the reactor core fuels as a object to be monitored and the actual movement of the object to be monitored. The results of the preparation are outputted. As an output mode, (1) the results of preparation for each of the paths for movement and the results of the monitoring obtained by monitoring the state of the object to be monitored are jointed and outputted, (2) images showing each of the paths for the movement are formed, and the formed images are displayed on a screen, and (3) each of the moving paths is prepared as an image, and the image is displayed together with the image of the regions before and after the movement of the object to be monitored. In addition, obtained images of each of the paths for the movement and the monitored images obtained by monitoring the state of the object to be monitored are joined and displayed. (I.S.)

  5. Analysis on the Effect of Sensor Views in Image Reconstruction Produced by Optical Tomography System Using Charge-Coupled Device.

    Science.gov (United States)

    Jamaludin, Juliza; Rahim, Ruzairi Abdul; Fazul Rahiman, Mohd Hafiz; Mohd Rohani, Jemmy

    2018-04-01

    Optical tomography (OPT) is a method to capture a cross-sectional image based on the data obtained by sensors, distributed around the periphery of the analyzed system. This system is based on the measurement of the final light attenuation or absorption of radiation after crossing the measured objects. The number of sensor views will affect the results of image reconstruction, where the high number of sensor views per projection will give a high image quality. This research presents an application of charge-coupled device linear sensor and laser diode in an OPT system. Experiments in detecting solid and transparent objects in crystal clear water were conducted. Two numbers of sensors views, 160 and 320 views are evaluated in this research in reconstructing the images. The image reconstruction algorithms used were filtered images of linear back projection algorithms. Analysis on comparing the simulation and experiments image results shows that, with 320 image views giving less area error than 160 views. This suggests that high image view resulted in the high resolution of image reconstruction.

  6. Development of on line automatic separation device for apple and sleeve

    Science.gov (United States)

    Xin, Dengke; Ning, Duo; Wang, Kangle; Han, Yuhang

    2018-04-01

    Based on STM32F407 single chip microcomputer as control core, automatic separation device of fruit sleeve is designed. This design consists of hardware and software. In hardware, it includes mechanical tooth separator and three degree of freedom manipulator, as well as industrial control computer, image data acquisition card, end effector and other structures. The software system is based on Visual C++ development environment, to achieve localization and recognition of fruit sleeve with the technology of image processing and machine vision, drive manipulator of foam net sets of capture, transfer, the designated position task. Test shows: The automatic separation device of the fruit sleeve has the advantages of quick response speed and high separation success rate, and can realize separation of the apple and plastic foam sleeve, and lays the foundation for further studying and realizing the application of the enterprise production line.

  7. Development of Portable Digital Radiography System with a Device for Monitoring X-ray Source-Detector Angle and Its Application in Chest Imaging

    Directory of Open Access Journals (Sweden)

    Tae-Hoon Kim

    2017-03-01

    Full Text Available This study developed a device measuring the X-ray source-detector angle (SDA and evaluated the imaging performance for diagnosing chest images. The SDA device consisted of Arduino, an accelerometer and gyro sensor, and a Bluetooth module. The SDA values were compared with the values of a digital angle meter. The performance of the portable digital radiography (PDR was evaluated using the signal-to-noise (SNR, contrast-to-noise ratio (CNR, spatial resolution, distortion and entrance surface dose (ESD. According to different angle degrees, five anatomical landmarks were assessed using a five-point scale. The mean SNR and CNR were 182.47 and 141.43. The spatial resolution and ESD were 3.17 lp/mm (157 μm and 0.266 mGy. The angle values of the SDA device were not significantly difference as compared to those of the digital angle meter. In chest imaging, the SNR and CNR values were not significantly different according to the different angle degrees. The visibility scores of the border of the heart, the fifth rib and the scapula showed significant differences according to different angles (p < 0.05, whereas the scores of the clavicle and first rib were not significant. It is noticeable that the increase in the SDA degree was consistent with the increases of the distortion and visibility score. The proposed PDR with a SDA device would be useful for application in the clinical radiography setting according to the standard radiography guidelines.

  8. Imaging the DNA damage response with PET and SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Knight, James C.; Koustoulidou, Sofia; Cornelissen, Bart [University of Oxford, CR-UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, Oxford (United Kingdom)

    2017-06-15

    DNA integrity is constantly challenged by endogenous and exogenous factors that can alter the DNA sequence, leading to mutagenesis, aberrant transcriptional activity, and cytotoxicity. Left unrepaired, damaged DNA can ultimately lead to the development of cancer. To overcome this threat, a series of complex mechanisms collectively known as the DNA damage response (DDR) are able to detect the various types of DNA damage that can occur and stimulate the appropriate repair process. Each DNA damage repair pathway leads to the recruitment, upregulation, or activation of specific proteins within the nucleus, which, in some cases, can represent attractive targets for molecular imaging. Given the well-established involvement of DDR during tumorigenesis and cancer therapy, the ability to monitor these repair processes non-invasively using nuclear imaging techniques may facilitate the earlier detection of cancer and may also assist in monitoring response to DNA damaging treatment. This review article aims to provide an overview of recent efforts to develop PET and SPECT radiotracers for imaging of DNA damage repair proteins. (orig.)

  9. Test Targets 2.0 and Digital Imaging

    Directory of Open Access Journals (Sweden)

    Robert Chung

    2003-04-01

    Full Text Available Current color management systems, based on a modular approach, enable color portability and mass customization of digital images for print. Because of the non-specific nature of the workflow, implementation of ICC-based color management becomes the responsibility of the user. As such the performance of ICC-based CMS is often unknown and has caused much confusion and slow adoption in the printing and publishing industries. To demonstrate how ICC-based color management can be implemented in a number of workflows, this paper describes a project, called Test Targets 2.0. A description of the test targets and how they were used for device calibration, device profiling, and color imaging applications under different workflows, e.g., from scanner to press, or digital camera to press, are introduced. Color management should work equally well for color matching applications. Thus, a continuation of the project focuses on device gamut and profile accuracy assessment.

  10. Photometric Calibration and Image Stitching for a Large Field of View Multi-Camera System

    Directory of Open Access Journals (Sweden)

    Yu Lu

    2016-04-01

    Full Text Available A new compact large field of view (FOV multi-camera system is introduced. The camera is based on seven tiny complementary metal-oxide-semiconductor sensor modules covering over 160° × 160° FOV. Although image stitching has been studied extensively, sensor and lens differences have not been considered in previous multi-camera devices. In this study, we have calibrated the photometric characteristics of the multi-camera device. Lenses were not mounted on the sensor in the process of radiometric response calibration to eliminate the influence of the focusing effect of uniform light from an integrating sphere. Linearity range of the radiometric response, non-linearity response characteristics, sensitivity, and dark current of the camera response function are presented. The R, G, and B channels have different responses for the same illuminance. Vignetting artifact patterns have been tested. The actual luminance of the object is retrieved by sensor calibration results, and is used to blend images to make panoramas reflect the objective luminance more objectively. This compensates for the limitation of stitching images that are more realistic only through the smoothing method. The dynamic range limitation of can be resolved by using multiple cameras that cover a large field of view instead of a single image sensor with a wide-angle lens. The dynamic range is expanded by 48-fold in this system. We can obtain seven images in one shot with this multi-camera system, at 13 frames per second.

  11. Fiber bundle probes for interconnecting miniaturized medical imaging devices

    Science.gov (United States)

    Zamora, Vanessa; Hofmann, Jens; Marx, Sebastian; Herter, Jonas; Nguyen, Dennis; Arndt-Staufenbiel, Norbert; Schröder, Henning

    2017-02-01

    Miniaturization of medical imaging devices will significantly improve the workflow of physicians in hospitals. Photonic integrated circuit (PIC) technologies offer a high level of miniaturization. However, they need fiber optic interconnection solutions for their functional integration. As part of European funded project (InSPECT) we investigate fiber bundle probes (FBPs) to be used as multi-mode (MM) to single-mode (SM) interconnections for PIC modules. The FBP consists of a set of four or seven SM fibers hexagonally distributed and assembled into a holder that defines a multicore connection. Such a connection can be used to connect MM fibers, while each SM fiber is attached to the PIC module. The manufacturing of these probes is explored by using well-established fiber fusion, epoxy adhesive, innovative adhesive and polishing techniques in order to achieve reliable, low-cost and reproducible samples. An innovative hydrofluoric acid-free fiber etching technology has been recently investigated. The preliminary results show that the reduction of the fiber diameter shows a linear behavior as a function of etching time. Different etch rate values from 0.55 μm/min to 2.3 μm/min were found. Several FBPs with three different type of fibers have been optically interrogated at wavelengths of 630nm and 1550nm. Optical losses are found of approx. 35dB at 1550nm for FBPs composed by 80μm fibers. Although FBPs present moderate optical losses, they might be integrated using different optical fibers, covering a broad spectral range required for imaging applications. Finally, we show the use of FBPs as promising MM-to-SM interconnects for real-world interfacing to PIC's.

  12. Near-Infrared to Visible Organic Upconversion Devices Based on Organic Light-Emitting Field Effect Transistors.

    Science.gov (United States)

    Li, Dongwei; Hu, Yongsheng; Zhang, Nan; Lv, Ying; Lin, Jie; Guo, Xiaoyang; Fan, Yi; Luo, Jinsong; Liu, Xingyuan

    2017-10-18

    The near-infrared (NIR) to visible upconversion devices have attracted great attention because of their potential applications in the fields of night vision, medical imaging, and military security. Herein, a novel all-organic upconversion device architecture has been first proposed and developed by incorporating a NIR absorption layer between the carrier transport layer and the emission layer in heterostructured organic light-emitting field effect transistors (OLEFETs). The as-prepared devices show a typical photon-to-photon upconversion efficiency as high as 7% (maximum of 28.7% under low incident NIR power intensity) and millisecond-scale response time, which are the highest upconversion efficiency and one of the fastest response time among organic upconversion devices as referred to the previous reports up to now. The high upconversion performance mainly originates from the gain mechanism of field-effect transistor structures and the unique advantage of OLEFETs to balance between the photodetection and light emission. Meanwhile, the strategy of OLEFETs also offers the advantage of high integration so that no extra OLED is needed in the organic upconversion devices. The results would pave way for low-cost, flexible and portable organic upconversion devices with high efficiency and simplified processing.

  13. Radiographic film digitizing devices

    International Nuclear Information System (INIS)

    McFee, W.H.

    1988-01-01

    Until recently, all film digitizing devices for use with teleradiology or picture archiving and communication systems used a video camera to capture an image of the radiograph for subsequent digitization. The development of film digitizers that use a laser beam to scan the film represents a significant advancement in digital technology, resulting in improved image quality compared with video scanners. This paper discusses differences in resolution, efficiency, reliability, and the cost between these two types of devices. The results of a modified receiver operating characteristic comparison study of a video scanner and a laser scanner manufactured by the same company are also discussed

  14. Non-Hodgkin lymphoma response evaluation with MRI texture classification

    Directory of Open Access Journals (Sweden)

    Heinonen Tomi T

    2009-06-01

    Full Text Available Abstract Background To show magnetic resonance imaging (MRI texture appearance change in non-Hodgkin lymphoma (NHL during treatment with response controlled by quantitative volume analysis. Methods A total of 19 patients having NHL with an evaluable lymphoma lesion were scanned at three imaging timepoints with 1.5T device during clinical treatment evaluation. Texture characteristics of images were analyzed and classified with MaZda application and statistical tests. Results NHL tissue MRI texture imaged before treatment and under chemotherapy was classified within several subgroups, showing best discrimination with 96% correct classification in non-linear discriminant analysis of T2-weighted images. Texture parameters of MRI data were successfully tested with statistical tests to assess the impact of the separability of the parameters in evaluating chemotherapy response in lymphoma tissue. Conclusion Texture characteristics of MRI data were classified successfully; this proved texture analysis to be potential quantitative means of representing lymphoma tissue changes during chemotherapy response monitoring.

  15. Impact of measuring electron tracks in high-resolution scientific charge-coupled devices within Compton imaging systems

    International Nuclear Information System (INIS)

    Chivers, D.H.; Coffer, A.; Plimley, B.; Vetter, K.

    2011-01-01

    We have implemented benchmarked models to determine the gain in sensitivity of electron-tracking based Compton imaging relative to conventional Compton imaging by the use of high-resolution scientific charge-coupled devices (CCD). These models are based on the recently demonstrated ability of electron-tracking based Compton imaging by using fully depleted scientific CCDs. Here we evaluate the gain in sensitivity by employing Monte Carlo simulations in combination with advanced charge transport models to calculate two-dimensional charge distributions corresponding to experimentally obtained tracks. In order to reconstruct the angle of the incident γ-ray, a trajectory determination algorithm was used on each track and integrated into a back-projection routine utilizing a geodesic-vertex ray tracing technique. Analysis was performed for incident γ-ray energies of 662 keV and results show an increase in sensitivity consistent with tracking of the Compton electron to approximately ±30 o .

  16. Characteristics of NaI detector in positron imaging device HEADTOME employing circular ring array

    International Nuclear Information System (INIS)

    Miura, Shuichi; Kanno, Iwao; Aizawa, Yasuo; Murakami, Matsutaro; Uemura, Kazuo

    1984-01-01

    In positron emission computed tomographs employing circular ring arrays of detectors, the performance of the imaging device has been specified ultimately by the characteristics of the detector. The responses of NaI detector were studied when detecting positron annihilation photon (511 keV). The study was mainly by using the NaI detector used in hybrid emission computed tomography (CT) ''HEADTOME'' we had developed. A series of measurements were carried out positioning two detectors with 40 cm distance and scanning 22 Na point source in water. Both detectors was inclined from 0 0 through 30 0 to change incident angle of positron annihilation toward crystal face. Energy window was set from 100 to 700 keV. The results were presented as follows; 1 Shortening the crystal length from 7 to 5 cm made sensitivity decrease about 10% and resolution deteriorate about 1 mm (FWHM). 2 As the results of varying the width of the crystal, 20 mm width was optimal at any incident angle. 3 The lead septum between the detectors was the thickness of 4 mm enough to reject multiple detector interactions (crosstalk). 4 Beam mask which was made of lead in order to improve spatial resolution and placed on crystal face worked effectively for incident angles from 0 0 to 15 0 but degraded uniformity of spatial resolution from 0 0 to through 30 0 . (author)

  17. Charge transport through image charged stabilized states in a single molecule single electron transistor device

    International Nuclear Information System (INIS)

    Hedegard, Per; Bjornholm, Thomas

    2005-01-01

    The present paper gives an elaborate theoretical description of a new molecular charge transport mechanism applying to a single molecule trapped between two macroscopic electrodes in a solid state device. It is shown by a Hubbard type model of the electronic and electrostatic interactions, that the close proximity of metal electrodes may allow electrons to tunnel from the electrode directly into very localized image charge stabilized states on the molecule. Due to this mechanism, an exceptionally large number of redox states may be visited within an energy scale which would normally not allow the molecular HOMO-LUMO gap to be transversed. With a reasonable set of parameters, a good fit to recent experimental values may be obtained. The theoretical model is furthermore used to search for the physical boundaries of this effect, and it is found that a rather narrow geometrical space is available for the new mechanism to work: in the specific case of oligophenylenevinylene molecules recently explored in such devices several atoms in the terminal benzene rings need to be at van der Waal's distance to the electrode in order for the mechanism to work. The model predicts, that chemisorption of the terminal benzene rings too gold electrodes will impede the image charge effect very significantly because the molecule is pushed away from the electrode by the covalent thiol-gold bond

  18. Nine-degrees-of-freedom flexmap for a cone-beam computed tomography imaging device with independently movable source and detector.

    Science.gov (United States)

    Keuschnigg, Peter; Kellner, Daniel; Fritscher, Karl; Zechner, Andrea; Mayer, Ulrich; Huber, Philipp; Sedlmayer, Felix; Deutschmann, Heinz; Steininger, Philipp

    2017-01-01

    Couch-mounted cone-beam computed tomography (CBCT) imaging devices with independently rotatable x-ray source and flat-panel detector arms for acquisitions of arbitrary regions of interest (ROI) have recently been introduced in image-guided radiotherapy (IGRT). This work analyzes mechanical limitations and gravity-induced effects influencing the geometric accuracy of images acquired with arbitrary angular constellations of source and detector in nonisocentric trajectories, which is considered essential for IGRT. In order to compensate for geometric inaccuracies of this modality, a 9-degrees-of-freedom (9-DOF) flexmap correction approach is presented, focusing especially on the separability of the flexmap parameters of the independently movable components of the device. The 9-DOF comprise a 3D translation of the x-ray source focal spot, a 3D translation of the flat-panel's active area center and three Euler-rotations of the detector's row and column vectors. The flexmap parameters are expressed with respect to the angular position of each of the devices arms. Estimation of the parameters is performed, using a CT-based structure set of a table-mounted, cylindrical ball-bearing phantom. Digitally reconstructed radiograph (DRR) patches are derived from the structure set followed by local 2D in-plane registration and subsequent 3D transform estimation by nonlinear regression with outlier detection. Flexmap parameter evaluations for the factory-calibrated system in clockwise and counter-clockwise rotation direction have shown only minor differences for the overall set of flexmap parameters. High short-term reproducibility of the flexmap parameters has been confirmed by experiments over 10 acquisitions for both directions, resulting in standard deviation values of ≤0.183 mm for translational components and ≤0.0219 deg for rotational components, respectively. A comparison of isocentric and nonisocentric flexmap evaluations showed that the mean differences of the

  19. Graphene device and method of using graphene device

    Science.gov (United States)

    Bouchiat, Vincent; Girit, Caglar; Kessler, Brian; Zettl, Alexander K.

    2015-08-11

    An embodiment of a graphene device includes a layered structure, first and second electrodes, and a dopant island. The layered structure includes a conductive layer, an insulating layer, and a graphene layer. The electrodes are coupled to the graphene layer. The dopant island is coupled to an exposed surface of the graphene layer between the electrodes. An embodiment of a method of using a graphene device includes providing the graphene device. A voltage is applied to the conductive layer of the graphene device. Another embodiment of a method of using a graphene device includes providing the graphene device without the dopant island. A dopant island is placed on an exposed surface of the graphene layer between the electrodes. A voltage is applied to the conductive layer of the graphene device. A response of the dopant island to the voltage is observed.

  20. Use of a line-pair resolution phantom for comprehensive quality assurance of electronic portal imaging devices based on fundamental imaging metrics

    International Nuclear Information System (INIS)

    Gopal, Arun; Samant, Sanjiv S.

    2009-01-01

    Image guided radiation therapy solutions based on megavoltage computed tomography (MVCT) involve the extension of electronic portal imaging devices (EPIDs) from their traditional role of weekly localization imaging and planar dose mapping to volumetric imaging for 3D setup and dose verification. To sustain the potential advantages of MVCT, EPIDs are required to provide improved levels of portal image quality. Therefore, it is vital that the performance of EPIDs in clinical use is maintained at an optimal level through regular and rigorous quality assurance (QA). Traditionally, portal imaging QA has been carried out by imaging calibrated line-pair and contrast resolution phantoms and obtaining arbitrarily defined QA indices that are usually dependent on imaging conditions and merely indicate relative trends in imaging performance. They are not adequately sensitive to all aspects of image quality unlike fundamental imaging metrics such as the modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) that are widely used to characterize detector performance in radiographic imaging and would be ideal for QA purposes. However, due to the difficulty of performing conventional MTF measurements, they have not been used for routine clinical QA. The authors present a simple and quick QA methodology based on obtaining the MTF, NPS, and DQE of a megavoltage imager by imaging standard open fields and a bar-pattern QA phantom containing 2 mm thick tungsten line-pair bar resolution targets. Our bar-pattern based MTF measurement features a novel zero-frequency normalization scheme that eliminates normalization errors typically associated with traditional bar-pattern measurements at megavoltage x-ray energies. The bar-pattern QA phantom and open-field images are used in conjunction with an automated image analysis algorithm that quickly computes the MTF, NPS, and DQE of an EPID system. Our approach combines the fundamental advantages of

  1. Diffractive optical variable image devices generated by maskless interferometric lithography for optical security

    Science.gov (United States)

    Cabral, Alexandre; Rebordão, José M.

    2011-05-01

    In optical security (protection against forgery and counterfeit of products and documents) the problem is not exact reproduction but the production of something sufficiently similar to the original. Currently, Diffractive Optically Variable Image Devices (DOVID), that create dynamic chromatic effects which may be easily recognized but are difficult to reproduce, are often used to protect important products and documents. Well known examples of DOVID for security are 3D or 2D/3D holograms in identity documents and credit cards. Others are composed of shapes with different types of microstructures yielding by diffraction to chromatic dynamic effects. A maskless interferometric lithography technique to generate DOVIDs for optical security is presented and compared to traditional techniques. The approach can be considered as a self-masking focused holography on planes tilted with respect to the reference optical axes of the system, and is based on the Scheimpflug and Hinge rules. No physical masks are needed to ensure optimum exposure of the photosensitive film. The system built to demonstrate the technique relies on the digital mirrors device MOEMS technology from Texas Instruments' Digital Light Processing. The technique is linear on the number of specified colors and does not depend either on the area of the device or the number of pixels, factors that drive the complexity of dot-matrix based systems. The results confirmed the technique innovation and capabilities in the creation of diffractive optical elements for security against counterfeiting and forgery.

  2. Study of the detective quantum efficiency for the kinestatic charge detector as a megavoltage imaging device

    Science.gov (United States)

    Samant, Sanjiv S.; Gopal, Arun; DiBianca, Frank A.

    2003-06-01

    Megavoltage x-ray imaging suffers from relatively poor contrast and spatial resolution compared to diagnostic kilovoltage x-ray imaging due to the dominant Compton scattering in the former. Recently available amorphous silicon/selenium based flat-panel imagers overcome many of the limitations of poor contrast and spatial resolution that affect conventional video based electronic portal imaging devices (EPIDs). An alternative technology is presented here: kinestatic charge detection (KCD). The KCD uses a slot photon beam, high-pressure gas (xenon, 100 atm) and a multi-ion rectangular chamber in scanning mode. An electric field is used to regulate the cation drift velocity. By matching the scanning speed with that of the cation drift, the cations remain static in the object frame of reference, allowing temporal integration of the signal. KCD imaging is characterized by reduced scatter and a high signal-to-noise ratio. Measurements and Monte Carlo simulations of modulation transfer function (MTF), noise power spectrum (NPS) and the detective quantum efficiency (DQE) of a prototype small field of view KCD detector (384 channels, 0.5 mm spacing) were carried out. Measurements yield DQE[0]=0.19 and DQE[0.5cy/mm]=0.01. KCD imaging is compared to film and commercial EPID systems using phantoms, with the KCD requiring an extremely low dose (0.1 cGy) per image. A proposed cylindrical chamber design with a higher ion-collection depth is expected to further improve image quality (DQE[0]>0.25).

  3. Response of GaAs charge storage devices to transient ionizing radiation

    Science.gov (United States)

    Hetherington, D. L.; Klem, J. F.; Hughes, R. C.; Weaver, H. T.

    Charge storage devices in which non-equilibrium depletion regions represent stored charge are sensitive to ionizing radiation. This results since the radiation generates electron-hole pairs that neutralize excess ionized dopant charge. Silicon structures, such as dynamic RAM or CCD cells are particularly sensitive to radiation since carrier diffusion lengths in this material are often much longer than the depletion width, allowing collection of significant quantities of charge from quasi-neutral sections of the device. For GaAs the situation is somewhat different in that minority carrier diffusion lengths are shorter than in silicon, and although mobilities are higher, we expect a reduction of radiation sensitivity as suggested by observations of reduced quantum efficiency in GaAs solar cells. Dynamic memory cells in GaAs have potential increased retention times. In this paper, we report the response of a novel GaAs dynamic memory element to transient ionizing radiation. The charge readout technique is nondestructive over a reasonable applied voltage range and is more sensitive to stored charge than a simple capacitor.

  4. Analysis of image heterogeneity using 2D Minkowski functionals detects tumor responses to treatment.

    Science.gov (United States)

    Larkin, Timothy J; Canuto, Holly C; Kettunen, Mikko I; Booth, Thomas C; Hu, De-En; Krishnan, Anant S; Bohndiek, Sarah E; Neves, André A; McLachlan, Charles; Hobson, Michael P; Brindle, Kevin M

    2014-01-01

    The acquisition of ever increasing volumes of high resolution magnetic resonance imaging (MRI) data has created an urgent need to develop automated and objective image analysis algorithms that can assist in determining tumor margins, diagnosing tumor stage, and detecting treatment response. We have shown previously that Minkowski functionals, which are precise morphological and structural descriptors of image heterogeneity, can be used to enhance the detection, in T1 -weighted images, of a targeted Gd(3+) -chelate-based contrast agent for detecting tumor cell death. We have used Minkowski functionals here to characterize heterogeneity in T2 -weighted images acquired before and after drug treatment, and obtained without contrast agent administration. We show that Minkowski functionals can be used to characterize the changes in image heterogeneity that accompany treatment of tumors with a vascular disrupting agent, combretastatin A4-phosphate, and with a cytotoxic drug, etoposide. Parameterizing changes in the heterogeneity of T2 -weighted images can be used to detect early responses of tumors to drug treatment, even when there is no change in tumor size. The approach provides a quantitative and therefore objective assessment of treatment response that could be used with other types of MR image and also with other imaging modalities. Copyright © 2013 Wiley Periodicals, Inc.

  5. Thermal imager based on the array light sensor device of 128×128 CdHgTe-photodiodes

    Directory of Open Access Journals (Sweden)

    Reva V. P.

    2010-08-01

    Full Text Available The results of investigation of developed thermal imager for middle (3—5 µm infrared region are presented and its applications features are discussed. The thermal imager consists of cooled to 80 K 128×128 diodes focal plane array on the base of cadmium–mercury–telluride compound and cryostat with temperature checking system. The photodiode array is bonded with readout device (silicon focal processor via indium microcontacts. The measured average value of noise equivalent temperature difference was NETD= 20±4 mK (background radiation temperature T = 300 K, field of view 2θ = 180°, the cooled diaphragm was not used.

  6. Metal artifact reduction image reconstruction algorithm for CT of implanted metal orthopedic devices: a work in progress

    International Nuclear Information System (INIS)

    Liu, Patrick T.; Pavlicek, William P.; Peter, Mary B.; Roberts, Catherine C.; Paden, Robert G.; Spangehl, Mark J.

    2009-01-01

    Despite recent advances in CT technology, metal orthopedic implants continue to cause significant artifacts on many CT exams, often obscuring diagnostic information. We performed this prospective study to evaluate the effectiveness of an experimental metal artifact reduction (MAR) image reconstruction program for CT. We examined image quality on CT exams performed in patients with hip arthroplasties as well as other types of implanted metal orthopedic devices. The exam raw data were reconstructed using two different methods, the standard filtered backprojection (FBP) program and the MAR program. Images were evaluated for quality of the metal-cement-bone interfaces, trabeculae ≤1 cm from the metal, trabeculae 5 cm apart from the metal, streak artifact, and overall soft tissue detail. The Wilcoxon Rank Sum test was used to compare the image scores from the large and small prostheses. Interobserver agreement was calculated. When all patients were grouped together, the MAR images showed mild to moderate improvement over the FBP images. However, when the cases were divided by implant size, the MAR images consistently received higher image quality scores than the FBP images for large metal implants (total hip prostheses). For small metal implants (screws, plates, staples), conversely, the MAR images received lower image quality scores than the FBP images due to blurring artifact. The difference of image scores for the large and small implants was significant (p=0.002). Interobserver agreement was found to be high for all measures of image quality (k>0.9). The experimental MAR reconstruction algorithm significantly improved CT image quality for patients with large metal implants. However, the MAR algorithm introduced blurring artifact that reduced image quality with small metal implants. (orig.)

  7. How Well Does the Latest Anthropomorphic Test Device Mimic Human Impact Responses?

    Science.gov (United States)

    Newby, Nate; Somers, Jeff; Caldewll, Erin; Gernhardt, Michael

    2014-01-01

    One of the goals of the NASA Occupant Protection Group is to understand the human tolerance to dynamic loading. This knowledge has to come through indirect approaches such as existing human response databases, anthropometric test devices (ATD), animal testing, post-­-mortem human subjects, and models. This study investigated the biofidelity of the National Highway Traffic Safety Administration's ATD named the THOR (test device for human occupant restraint). If THOR responds comparably to humans, then it could potentially be used as a human surrogate to help validate space vehicle requirements for occupant protection. The THOR responses to frontal and spinal impacts (ranging from 8 to 12 G with rise times of 40, 70, and 100 ms) were measured and compared to human volunteer responses (95 trials in frontal and 58 in spinal) previously collected by the U. S. Air Force on the same horizontal impact accelerator. The impact acceleration profiles tested are within the expected range of multi-­-purpose crew vehicle (MPCV) landing dynamics. A correlation score was calculated for each THOR to human comparison using CORA (CORrelation and Analysis) software. A two-­-parameter beta distribution model fit was obtained for each dependent variable using maximum likelihood estimation. For frontal impacts, the THOR head x-­-acceleration peak response correlated with the human response at 8 and 10-­-G 100 ms but not 10-­-G 70 ms. The phase lagged the human response. Head z-­-acceleration was not correlated. Chest x-­-acceleration was in phase, had a higher peak response, and was well correlated with lighter subjects (Cora = 0.8 for 46 kg vs. Cora = 0.4 for 126 kg). Head x-­-displacement had a leading phase. Several subjects responded with the same peak displacement but the mean of the group was lower. The shoulder x-­-displacement was in phase but had higher peaks than the human response. For spinal impacts, the THOR head x-­-acceleration was not well correlated. Head and

  8. Imaging the motion of electrons across semiconductor heterojunctions

    Science.gov (United States)

    Man, Michael K. L.; Margiolakis, Athanasios; Deckoff-Jones, Skylar; Harada, Takaaki; Wong, E. Laine; Krishna, M. Bala Murali; Madéo, Julien; Winchester, Andrew; Lei, Sidong; Vajtai, Robert; Ajayan, Pulickel M.; Dani, Keshav M.

    2017-01-01

    Technological progress since the late twentieth century has centred on semiconductor devices, such as transistors, diodes and solar cells. At the heart of these devices is the internal motion of electrons through semiconductor materials due to applied electric fields or by the excitation of photocarriers. Imaging the motion of these electrons would provide unprecedented insight into this important phenomenon, but requires high spatial and temporal resolution. Current studies of electron dynamics in semiconductors are generally limited by the spatial resolution of optical probes, or by the temporal resolution of electronic probes. Here, by combining femtosecond pump-probe techniques with spectroscopic photoemission electron microscopy, we imaged the motion of photoexcited electrons from high-energy to low-energy states in a type-II 2D InSe/GaAs heterostructure. At the instant of photoexcitation, energy-resolved photoelectron images revealed a highly non-equilibrium distribution of photocarriers in space and energy. Thereafter, in response to the out-of-equilibrium photocarriers, we observed the spatial redistribution of charges, thus forming internal electric fields, bending the semiconductor bands, and finally impeding further charge transfer. By assembling images taken at different time-delays, we produced a movie lasting a few trillionths of a second of the electron-transfer process in the photoexcited type-II heterostructure—a fundamental phenomenon in semiconductor devices such as solar cells. Quantitative analysis and theoretical modelling of spatial variations in the movie provide insight into future solar cells, 2D materials and other semiconductor devices.

  9. Radiation effects in charge coupled devices

    International Nuclear Information System (INIS)

    Williams, R.A.; Nelson, R.D.

    1975-01-01

    Charge coupled devices (CCD s) exhibit a number of advantages (low cost, low power, high bit density) in their several applications (serial memories, imagers, digital filters); however, fairly elementary theoretical considerations indicate that they will be very vulnerable to permanent radiation damage, by both neutrons and ionizing radiation, and to transient upset by pulsed ionizing radiation. Although studies of permanent ionizing-radiation damage in CCD's have been reported, little information has been published concerning their overall nuclear radiation vulnerability. This paper presents a fairly comprehensive experimental study of radiation effects in a 256-cell surface-channel, CCD shift-register. A limited amount of similar work is also presented for a 128-cell surface-channel device and a 130 cell peristaltic CCD shift register. The radiation effects phenomena discussed herein, include transient-ionizing-radiation responses, permanent ionizing- radiation damage to transfer efficiency, charge-carrying capacity and input transfer gate bias, and neutron damage to storage time--determined from dark current and charge-up time measurements

  10. Science-based response planning guidance for the first 100 minutes of the response to a radiological dispersal device

    International Nuclear Information System (INIS)

    Musolino, S.V.; Harper, F.T.

    2016-01-01

    The first 100 minutes of a response to a radiological dispersal device are critical as this period will set the stage for how the overall response will be executed. First responders will be tasked with multiple activities such as confirming a radiological release, conducting lifesaving rescue operations, issuing protective actions, and beginning characterization of the scene. These activities need to take place as soon as the responders arrive on the scene (the first few minutes). The effectiveness of these early activities will define how well or how poorly the response will be in the emergency phase. The document which is under development provides guidance that can be used for planning an effective response to an RDD that will result in protection of the responders and the members of the public. The information is based on research and results of extensive experiments conducted by the Department of Energy National Laboratories. This guidance provides a realistic estimate of the possible consequences of an RDD detonation and delineates five missions and ten tactics that should be executed by the first responders and local response agencies in the first 100 minutes of a response. The guidance includes recommendations on how to execute the strategy, equipment requirements including personal protective equipment and public messaging

  11. SU-G-BRA-06: Quantification of Tracking Performance of a Multi-Layer Electronic Portal Imaging Device

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Y; Rottmann, J; Myronakis, M; Berbeco, R [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA (United States)

    2016-06-15

    Purpose: The purpose of this study was to quantify the improvement in tumor tracking, with and without fiducial markers, afforded by employing a multi-layer (MLI) electronic portal imaging device (EPID) over the current state-of-the-art, single-layer, digital megavolt imager (DMI) architecture. Methods: An ideal observer signal-to-noise ratio (d’) approach was used to quantify the ability of an MLI EPID and a current, state-of-the-art DMI EPID to track lung tumors from the treatment beam’s-eye-view. Using each detector modulation transfer function (MTF) and noise power spectrum (NPS) as inputs, a detection task was employed with object functions describing simple three-dimensional Cartesian shapes (spheres and cylinders). Marker-less tumor tracking algorithms often use texture discrimination to differentiate benign and malignant tissue. The performance of such algorithms is simulated by employing a discrimination task for the ideal observer, which measures the ability of a system to differentiate two image quantities. These were defined as the measured textures for benign and malignant lung tissue. Results: The NNPS of the MLI ∼25% of that of the DMI at the expense of decreased MTF at intermediate frequencies (0.25≤imager layers. This implies that further improvements in tracking may be gained through increasing the thickness of each MLI layer. For tracking, the MLI performance is limited by noise response. Losses in MTF result in negligible differences in d

  12. Predictors of response to a nasal expiratory resistor device and its potential mechanisms of action for treatment of obstructive sleep apnea.

    Science.gov (United States)

    Patel, Amit V; Hwang, Dennis; Masdeu, Maria J; Chen, Guo-Ming; Rapoport, David M; Ayappa, Indu

    2011-02-15

    A one-way nasal resistor has recently been shown to reduce sleep disordered breathing (SDB) in a subset of patients with Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS). The purpose of this study was to examine characteristics predictive of therapeutic response to the device and provide pilot data as to its potential mechanisms of action. PATIENTS, INTERVENTIONS, AND MEASUREMENTS: 20 subjects (15M/5F, age 54 ± 12 years, BMI 33.5 ± 5.6 kg/m²) with OSAHS underwent 3 nocturnal polysomnograms (NPSG) including diagnostic, therapeutic (with a Provent® nasal valve device), and CPAP. Additional measurements included intranasal pressures and PCO₂, closing pressures (Pcrit), and awake lung volumes in different body positions. In 19/20 patients who slept with the device, RDI was significantly reduced with the nasal valve device compared to the diagnostic NPSG (27 ± 29/h vs 49 ± 28/h), with 50% of patients having an acceptable therapeutic response. Among demographic, lung volume, or diagnostic NPSG measures or markers of collapsibility, no significant predictors of therapeutic response were found. There was a suggestion that patients with position-dependent SDB (supine RDI > lateral RDI) were more likely to have an acceptable therapeutic response to the device. Successful elimination of SDB was associated with generation and maintenance of an elevated end expiratory pressure. No single definitive mechanism of action was elucidated. The present study shows that the nasal valve device can alter SDB across the full spectrum of SDB severity. There was a suggestion that subjects with positional or milder SDB in the lateral position were those most likely to respond.

  13. Imaging response during therapy with radium-223 for castration-resistant prostate cancer with bone metastases

    DEFF Research Database (Denmark)

    Keizman, D; Fosboel, M O; Reichegger, H

    2017-01-01

    BACKGROUND: The imaging response to radium-223 therapy is at present poorly described. We aimed to describe the imaging response to radium-223 treatment. METHODS: We retrospectively evaluated the computed tomography (CT) and bone scintigraphy response of metastatic castration-resistant prostate c....../or radiological) may be noted during the first 3 months, and should not be confused with progression. Imaging by CT scan should be considered after three and six doses of radium-223 to rule out extraskeletal disease progression....

  14. Quantitative SPECT brain imaging: Effects of attenuation and detector response

    International Nuclear Information System (INIS)

    Gilland, D.R.; Jaszczak, R.J.; Bowsher, J.E.; Turkington, T.G.; Liang, Z.; Greer, K.L.; Coleman, R.E.

    1993-01-01

    Two physical factors that substantially degrade quantitative accuracy in SPECT imaging of the brain are attenuation and detector response. In addition to the physical factors, random noise in the reconstructed image can greatly affect the quantitative measurement. The purpose of this work was to implement two reconstruction methods that compensate for attenuation and detector response, a 3D maximum likelihood-EM method (ML) and a filtered backprojection method (FB) with Metz filter and Chang attenuation compensation, and compare the methods in terms of quantitative accuracy and image noise. The methods were tested on simulated data of the 3D Hoffman brain phantom. The simulation incorporated attenuation and distance-dependent detector response. Bias and standard deviation of reconstructed voxel intensities were measured in the gray and white matter regions. The results with ML showed that in both the gray and white matter regions as the number of iterations increased, bias decreased and standard deviation increased. Similar results were observed with FB as the Metz filter power increased. In both regions, ML had smaller standard deviation than FB for a given bias. Reconstruction times for the ML method have been greatly reduced through efficient coding, limited source support, and by computing attenuation factors only along rays perpendicular to the detector

  15. Registration of partially overlapping surfaces for range image based augmented reality on mobile devices

    Science.gov (United States)

    Kilgus, T.; Franz, A. M.; Seitel, A.; Marz, K.; Bartha, L.; Fangerau, M.; Mersmann, S.; Groch, A.; Meinzer, H.-P.; Maier-Hein, L.

    2012-02-01

    Visualization of anatomical data for disease diagnosis, surgical planning, or orientation during interventional therapy is an integral part of modern health care. However, as anatomical information is typically shown on monitors provided by a radiological work station, the physician has to mentally transfer internal structures shown on the screen to the patient. To address this issue, we recently presented a new approach to on-patient visualization of 3D medical images, which combines the concept of augmented reality (AR) with an intuitive interaction scheme. Our method requires mounting a range imaging device, such as a Time-of-Flight (ToF) camera, to a portable display (e.g. a tablet PC). During the visualization process, the pose of the camera and thus the viewing direction of the user is continuously determined with a surface matching algorithm. By moving the device along the body of the patient, the physician is given the impression of looking directly into the human body. In this paper, we present and evaluate a new method for camera pose estimation based on an anisotropic trimmed variant of the well-known iterative closest point (ICP) algorithm. According to in-silico and in-vivo experiments performed with computed tomography (CT) and ToF data of human faces, knees and abdomens, our new method is better suited for surface registration with ToF data than the established trimmed variant of the ICP, reducing the target registration error (TRE) by more than 60%. The TRE obtained (approx. 4-5 mm) is promising for AR visualization, but clinical applications require maximization of robustness and run-time.

  16. Design of the Caltrans Seismic Response Modification Device (SRMD) test facility

    International Nuclear Information System (INIS)

    Benzoni, G.; Seible, F.

    1998-01-01

    In the Seismic retrofit design of California's Toll Bridges, seismic isolation is used in several bridges to limit the seismic force input into the superstructure and to avoid costly superstructure retrofit measures which would require partial lane closures and traffic interruptions. Isolation bearings and dampers of the size required for these large span bridges have not been built or tested to date. This paper describes the design and construction of a full scale testing facility which will allow the real-time 6-DOF dynamic characterization of the seismic response modification devices designed for California's Toll Bridges. (author)

  17. Performance study of a fan beam collimator designed for a multi-modality small animal imaging device

    International Nuclear Information System (INIS)

    Sabbir Ahmed, ASM; Kramer, Gary H.; Semmler, Wolfrad; Peter, Jorg

    2011-01-01

    This paper describes the methodology to design and conduct the performances of a fan beam collimator. This fan beam collimator was designed to use with a multi-modality small animal imaging device and the performance of the collimator was studied for a 3D geometry. Analytical expressions were formulated to calculate the parameters for the collimator. A Monte Carlo model was developed to analyze the scattering and image noises for a 3D object. The results showed that the performance of the fan beam collimator was strongly dependent on the source distribution and position. The fan beam collimator showed increased counting efficiency in comparison to a parallel hole collimator. Inside attenuating medium, the increased attenuating effect outweighed the fan beam increased counting efficiency.

  18. Prosthetic vision: devices, patient outcomes and retinal research.

    Science.gov (United States)

    Hadjinicolaou, Alex E; Meffin, Hamish; Maturana, Matias I; Cloherty, Shaun L; Ibbotson, Michael R

    2015-09-01

    Retinal disease and its associated retinal degeneration can lead to the loss of photoreceptors and therefore, profound blindness. While retinal degeneration destroys the photoreceptors, the neural circuits that convey information from the eye to the brain are sufficiently preserved to make it possible to restore sight using prosthetic devices. Typically, these devices consist of a digital camera and an implantable neurostimulator. The image sensor in a digital camera has the same spatiotopic arrangement as the photoreceptors of the retina. Therefore, it is possible to extract meaningful spatial information from an image and deliver it via an array of stimulating electrodes directly to the surviving retinal circuits. Here, we review the structure and function of normal and degenerate retina. The different approaches to prosthetic implant design are described in the context of human and preclinical trials. In the last section, we review studies of electrical properties of the retina and its response to electrical stimulation. These types of investigation are currently assessing a number of key challenges identified in human trials, including stimulation efficacy, spatial localisation, desensitisation to repetitive stimulation and selective activation of retinal cell populations. © 2015 The Authors. Clinical and Experimental Optometry © 2015 Optometry Australia.

  19. Monte-Carlo simulations and image reconstruction for novel imaging scenarios in emission tomography

    International Nuclear Information System (INIS)

    Gillam, John E.; Rafecas, Magdalena

    2016-01-01

    Emission imaging incorporates both the development of dedicated devices for data acquisition as well as algorithms for recovering images from that data. Emission tomography is an indirect approach to imaging. The effect of device modification on the final image can be understood through both the way in which data are gathered, using simulation, and the way in which the image is formed from that data, or image reconstruction. When developing novel devices, systems and imaging tasks, accurate simulation and image reconstruction allow performance to be estimated, and in some cases optimized, using computational methods before or during the process of physical construction. However, there are a vast range of approaches, algorithms and pre-existing computational tools that can be exploited and the choices made will affect the accuracy of the in silico results and quality of the reconstructed images. On the one hand, should important physical effects be neglected in either the simulation or reconstruction steps, specific enhancements provided by novel devices may not be represented in the results. On the other hand, over-modeling of device characteristics in either step leads to large computational overheads that can confound timely results. Here, a range of simulation methodologies and toolkits are discussed, as well as reconstruction algorithms that may be employed in emission imaging. The relative advantages and disadvantages of a range of options are highlighted using specific examples from current research scenarios.

  20. Monte-Carlo simulations and image reconstruction for novel imaging scenarios in emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Gillam, John E. [The University of Sydney, Faculty of Health Sciences and The Brain and Mind Centre, Camperdown (Australia); Rafecas, Magdalena, E-mail: rafecas@imt.uni-luebeck.de [University of Lubeck, Institute of Medical Engineering, Ratzeburger Allee 160, 23538 Lübeck (Germany)

    2016-02-11

    Emission imaging incorporates both the development of dedicated devices for data acquisition as well as algorithms for recovering images from that data. Emission tomography is an indirect approach to imaging. The effect of device modification on the final image can be understood through both the way in which data are gathered, using simulation, and the way in which the image is formed from that data, or image reconstruction. When developing novel devices, systems and imaging tasks, accurate simulation and image reconstruction allow performance to be estimated, and in some cases optimized, using computational methods before or during the process of physical construction. However, there are a vast range of approaches, algorithms and pre-existing computational tools that can be exploited and the choices made will affect the accuracy of the in silico results and quality of the reconstructed images. On the one hand, should important physical effects be neglected in either the simulation or reconstruction steps, specific enhancements provided by novel devices may not be represented in the results. On the other hand, over-modeling of device characteristics in either step leads to large computational overheads that can confound timely results. Here, a range of simulation methodologies and toolkits are discussed, as well as reconstruction algorithms that may be employed in emission imaging. The relative advantages and disadvantages of a range of options are highlighted using specific examples from current research scenarios.

  1. Detection of microbial biofilms on food processing surfaces: hyperspectral fluorescence imaging study

    Science.gov (United States)

    Jun, Won; Kim, Moon S.; Chao, Kaunglin; Lefcourt, Alan M.; Roberts, Michael S.; McNaughton, James L.

    2009-05-01

    We used a portable hyperspectral fluorescence imaging system to evaluate biofilm formations on four types of food processing surface materials including stainless steel, polypropylene used for cutting boards, and household counter top materials such as formica and granite. The objective of this investigation was to determine a minimal number of spectral bands suitable to differentiate microbial biofilm formation from the four background materials typically used during food processing. Ultimately, the resultant spectral information will be used in development of handheld portable imaging devices that can be used as visual aid tools for sanitation and safety inspection (microbial contamination) of the food processing surfaces. Pathogenic E. coli O157:H7 and Salmonella cells were grown in low strength M9 minimal medium on various surfaces at 22 +/- 2 °C for 2 days for biofilm formation. Biofilm autofluorescence under UV excitation (320 to 400 nm) obtained by hyperspectral fluorescence imaging system showed broad emissions in the blue-green regions of the spectrum with emission maxima at approximately 480 nm for both E. coli O157:H7 and Salmonella biofilms. Fluorescence images at 480 nm revealed that for background materials with near-uniform fluorescence responses such as stainless steel and formica cutting board, regardless of the background intensity, biofilm formation can be distinguished. This suggested that a broad spectral band in the blue-green regions can be used for handheld imaging devices for sanitation inspection of stainless, cutting board, and formica surfaces. The non-uniform fluorescence responses of granite make distinctions between biofilm and background difficult. To further investigate potential detection of the biofilm formations on granite surfaces with multispectral approaches, principal component analysis (PCA) was performed using the hyperspectral fluorescence image data. The resultant PCA score images revealed distinct contrast between

  2. Characterization of lipid films by an angle-interrogation surface plasmon resonance imaging device.

    Science.gov (United States)

    Liu, Linlin; Wang, Qiong; Yang, Zhong; Wang, Wangang; Hu, Ning; Luo, Hongyan; Liao, Yanjian; Zheng, Xiaolin; Yang, Jun

    2015-04-01

    Surface topographies of lipid films have an important significance in the analysis of the preparation of giant unilamellar vesicles (GUVs). In order to achieve accurately high-throughput and rapidly analysis of surface topographies of lipid films, a homemade SPR imaging device is constructed based on the classical Kretschmann configuration and an angle interrogation manner. A mathematical model is developed to accurately describe the shift including the light path in different conditions and the change of the illumination point on the CCD camera, and thus a SPR curve for each sampling point can also be achieved, based on this calculation method. The experiment results show that the topographies of lipid films formed in distinct experimental conditions can be accurately characterized, and the measuring resolution of the thickness lipid film may reach 0.05 nm. Compared with existing SPRi devices, which realize detection by monitoring the change of the reflective-light intensity, this new SPRi system can achieve the change of the resonance angle on the entire sensing surface. Thus, it has higher detection accuracy as the traditional angle-interrogation SPR sensor, with much wider detectable range of refractive index. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Simultaneous application of two independent EIT devices for real-time multi-plane imaging.

    Science.gov (United States)

    Schullcke, B; Krueger-Ziolek, S; Gong, B; Mueller-Lisse, U; Moeller, K

    2016-09-01

    Diagnosis and treatment of many lung diseases like cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD) could benefit from 3D ventilation information. Applying two EIT systems concurrently is a simple approach without specialized hardware that allows monitoring of regional changes of ventilation distribution inside the thorax at different planes with the high temporal resolution much valued in common single plane EIT. Effects of two simultaneously operated EIT devices on one subject were investigated to monitor rapid processes inside the thorax with a multi-plane approach. Results obtained by simulations with a virtual phantom and measurements with a phantom tank reveal that the distance of electrode planes has an important influence on the signal quality. Band-pass filters adapted according to the distance of the planes, can be used to reduce the crosstalk of the concurrent EIT systems. Besides simulations and phantom tank experiments measurements were also taken from a lung healthy volunteer to demonstrate the operation under realistic conditions. Reconstructed images indicate that it is possible to simultaneously visualize regional ventilation at different planes if settings of the EIT devices are chosen appropriately.

  4. Radio imaging moving poly functional device development R.I.T.M. Medicine and biology applications

    International Nuclear Information System (INIS)

    Saoudi, A.

    1994-07-01

    We want to the medicine request. They wish to set out weak dimension nuclear imaging equipment, allowing to be movable indeed exploitable during the operation. We are using radioactive tracers either γ or β. For the postoperatory phases, no efficient and quick method of total ''osteoid-osteoma'' exeresis was existing. The device permitted to see if the extracted pieces included the maximal radioactivity zone, essential information on the surgery therapy quality, before the anatomy pathology tests. 36 refs., 109 figs., 3 tabs., 1 appendix

  5. University Social Responsibility and Brand Image of Private Universities in Bangkok

    Science.gov (United States)

    Plungpongpan, Jirawan; Tiangsoongnern, Leela; Speece, Mark

    2016-01-01

    Purpose: The purpose of this paper is to examine the effects of university social responsibility (USR) on the brand image of private universities in Thailand. Brand image is important for entry into the consideration set as prospective students evaluate options for university study. USR activities may be implicit or explicit, i.e., actively…

  6. Design of free space optical omnidirectional transceivers for indoor applications using non-imaging optical devices

    Science.gov (United States)

    Agrawal, Navik; Davis, Christopher C.

    2008-08-01

    Omnidirectional free space optical communication receivers can employ multiple non-imaging collectors, such as compound parabolic concentrators (CPCs), in an array-like fashion to increase the amount of possible light collection. CPCs can effectively channel light collected over a large aperture to a small area photodiode. The aperture to length ratio of such devices can increase the overall size of the transceiver unit, which may limit the practicality of such systems, especially when small size is desired. New non-imaging collector designs with smaller sizes, larger field of view (FOV), and comparable transmission curves to CPCs, offer alternative transceiver designs. This paper examines how transceiver performance is affected by the use of different non-imaging collector shapes that are designed for wide FOV with reduced efficiency compared with shapes such as the CPC that are designed for small FOV with optimal efficiency. Theoretical results provide evidence indicating that array-like transceiver designs using various non-imaging collector shapes with less efficient transmission curves, but a larger FOV will be an effective means for the design of omnidirectional optical transceiver units. The results also incorporate the effects of Fresnel loss at the collector exit aperture-photodiode interface, which is an important consideration for indoor omnidirectional FSO systems.

  7. Prototype of sun projector device

    Science.gov (United States)

    Ihsan; Dermawan, B.

    2016-11-01

    One way to introduce astronomy to public, including students, can be handled by solar observation. The widely held device for this purpose is coelostat and heliostat. Besides using filter attached to a device such as telescope, it is safest to use indirect way for observing the Sun. The main principle of the indirect way is deflecting the sun light and projecting image of the sun on a screen. We design and build a simple and low-cost astronomical device, serving as a supplement to increase public service, especially for solar observation. Without using any digital and intricate supporting equipment, people can watch and relish image of the Sun in comfortable condition, i.e. in a sheltered or shady place. Here we describe a design and features of our prototype of the device, which still, of course, has some limitations. In the future, this prototype can be improved for more efficient and useful applications.

  8. Slew-rate dependence of tracer magnetization response in magnetic particle imaging

    Science.gov (United States)

    Shah, Saqlain A.; Ferguson, R. M.; Krishnan, K. M.

    2014-10-01

    Magnetic Particle Imaging (MPI) is a new biomedical imaging technique that produces real-time, high-resolution tomographic images of superparamagnetic iron oxide nanoparticle tracers. Currently, 25 kHz and 20 mT/μ0 excitation fields are common in MPI, but lower field amplitudes may be necessary for patient safety in future designs. Here, we address fundamental questions about MPI tracer magnetization dynamics and predict tracer performance in future scanners that employ new combinations of excitation field amplitude (Ho) and frequency (ω). Using an optimized, monodisperse MPI tracer, we studied how several combinations of drive field frequencies and amplitudes affect the tracer's response, using Magnetic Particle Spectrometry and AC hysteresis, for drive field conditions at 15.5, 26, and 40.2 kHz, with field amplitudes ranging from 7 to 52 mT/μ0. For both fluid and immobilized nanoparticle samples, we determined that magnetic response was dominated by Néel reversal. Furthermore, we observed that the peak slew-rate (ωHo) determined the tracer magnetic response. Smaller amplitudes provided correspondingly smaller field of view, sometimes resulting in excitation of minor hysteresis loops. Changing the drive field conditions but keeping the peak slew-rate constant kept the tracer response almost the same. Higher peak slew-rates led to reduced maximum signal intensity and greater coercivity in the tracer response. Our experimental results were in reasonable agreement with Stoner-Wohlfarth model based theories.

  9. Idiopathic Chronic Parotitis: Imaging Findings and Sialendoscopic Response.

    Science.gov (United States)

    Heineman, Thomas E; Kacker, Ashutosh; Kutler, David I

    2015-01-01

    The purpose of this study was to correlate imaging and sialendoscopic findings to therapeutic response in patients with idiopathic chronic parotitis. We retrospectively reviewed 122 consecutive sialendoscopies performed in an academic medical center by two surgeons between 2008 and 2013. Forty-one (34%) and 54 (44%) patients were excluded on the basis of having parotid or submandibular sialolith, respectively. Nineteen cases were included in the study with idiopathic chronic parotitis. There was a median follow-up of 5 months. Computed tomography (CT) imaging had a sensitivity and specificity of 80.0 and 71.4%, respectively, for predicting abnormal findings on sialendoscopy, while magnetic resonance imaging (MRI) had 100% accuracy in a small set of cases. In glands with noticeable pathology present on preoperative imaging or sialendoscopy, 11 out of 12 glands (92%) treated experienced symptomatic improvement, while 3 out of 7 glands (43%) without pathology on imaging or endoscopy experienced symptomatic improvement (p = 0.038). Sialendoscopy for the treatment of idiopathic chronic parotid disease can improve pain and swelling with a higher frequency of success in patients with abnormalities noted on endoscopy. CT and MRI have a moderate degree of accuracy in predicting which patients will benefit from therapeutic sialendoscopy. © 2015 S. Karger AG, Basel.

  10. Nonlinear ultrasonic imaging method for closed cracks using subtraction of responses at different external loads.

    Science.gov (United States)

    Ohara, Yoshikazu; Horinouchi, Satoshi; Hashimoto, Makoto; Shintaku, Yohei; Yamanaka, Kazushi

    2011-08-01

    To improve the selectivity of closed cracks for objects other than cracks in ultrasonic imaging, we propose an extension of a novel imaging method, namely, subharmonic phased array for crack evaluation (SPACE) as well as another approach using the subtraction of responses at different external loads. By applying external static or dynamic loads to closed cracks, the contact state in the cracks varies, resulting in an intensity change of responses at cracks. In contrast, objects other than cracks are independent of external load. Therefore, only cracks can be extracted by subtracting responses at different loads. In this study, we performed fundamental experiments on a closed fatigue crack formed in an aluminum alloy compact tension (CT) specimen using the proposed method. We examined the static load dependence of SPACE images and the dynamic load dependence of linear phased array (PA) images by simulating the external loads with a servohydraulic fatigue testing machine. By subtracting the images at different external loads, we show that this method is useful in extracting only the intensity change of responses related to closed cracks, while canceling the responses of objects other than cracks. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. NeuroSeek dual-color image processing infrared focal plane array

    Science.gov (United States)

    McCarley, Paul L.; Massie, Mark A.; Baxter, Christopher R.; Huynh, Buu L.

    1998-09-01

    Several technologies have been developed in recent years to advance the state of the art of IR sensor systems including dual color affordable focal planes, on-focal plane array biologically inspired image and signal processing techniques and spectral sensing techniques. Pacific Advanced Technology (PAT) and the Air Force Research Lab Munitions Directorate have developed a system which incorporates the best of these capabilities into a single device. The 'NeuroSeek' device integrates these technologies into an IR focal plane array (FPA) which combines multicolor Midwave IR/Longwave IR radiometric response with on-focal plane 'smart' neuromorphic analog image processing. The readout and processing integrated circuit very large scale integration chip which was developed under this effort will be hybridized to a dual color detector array to produce the NeuroSeek FPA, which will have the capability to fuse multiple pixel-based sensor inputs directly on the focal plane. Great advantages are afforded by application of massively parallel processing algorithms to image data in the analog domain; the high speed and low power consumption of this device mimic operations performed in the human retina.

  12. Potential Applications of Microtesla Magnetic Resonance Imaging Detected Using a Superconducting Quantum Interference Device

    International Nuclear Information System (INIS)

    Myers, Whittier R.

    2006-01-01

    This dissertation describes magnetic resonance imaging (MRI) of protons performed in a precession field of 132 (micro)T. In order to increase the signal-to-noise ratio (SNR), a pulsed 40-300 mT magnetic field prepolarizes the sample spins and an untuned second-order superconducting gradiometer coupled to a low transition temperature superconducting quantum interference device (SQUID) detects the subsequent 5.6-kHz spin precession. Imaging sequences including multiple echoes and partial Fourier reconstruction are developed. Calculating the SNR of prepolarized SQUID-detected MRI shows that three-dimensional Fourier imaging yields higher SNR than slice-selection imaging. An experimentally demonstrated field-cycling pulse sequence and post-processing algorithm mitigate image artifacts caused by concomitant gradients in low-field MRI. The magnetic field noise of SQUID untuned detection is compared to the noise of SQUID tuned detection, conventional Faraday detection, and the Nyquist noise generated by conducting biological samples. A second-generation microtesla MRI system employing a low-noise SQUID is constructed to increase SNR. A 2.4-m cubic, eddy-current shield with 6-mm thick aluminum walls encloses the experiment to attenuate external noise. The measured noise is 0.75 fT Hz -1/2 referred to the bottom gradiometer loop. Solenoids wound from 30-strand braided wire to decrease Nyquist noise and cooled by either liquid nitrogen or water polarize the spins. Copper wire coils wound on wooden supports produce the imaging magnetic fields and field gradients. Water phantom images with 0.8 x 0.8 x 10 mm 3 resolution have a SNR of 6. Three-dimensional 1.6 x 1.9 x 14 mm 3 images of bell peppers and 3 x 3 x 26 mm 3 in vivo images of the human arm are presented. Since contrast based on the transverse spin relaxation rate (T 1 ) is enhanced at low magnetic fields, microtesla MRI could potentially be used for tumor imaging. The measured T 1 of ex vivo normal and cancerous

  13. Potential Applications of Microtesla Magnetic Resonance ImagingDetected Using a Superconducting Quantum Interference Device

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Whittier Ryan [Univ. of California, Berkeley, CA (United States)

    2006-01-01

    This dissertation describes magnetic resonance imaging (MRI) of protons performed in a precession field of 132 μT. In order to increase the signal-to-noise ratio (SNR), a pulsed 40-300 mT magnetic field prepolarizes the sample spins and an untuned second-order superconducting gradiometer coupled to a low transition temperature superconducting quantum interference device (SQUID) detects the subsequent 5.6-kHz spin precession. Imaging sequences including multiple echoes and partial Fourier reconstruction are developed. Calculating the SNR of prepolarized SQUID-detected MRI shows that three-dimensional Fourier imaging yields higher SNR than slice-selection imaging. An experimentally demonstrated field-cycling pulse sequence and post-processing algorithm mitigate image artifacts caused by concomitant gradients in low-field MRI. The magnetic field noise of SQUID untuned detection is compared to the noise of SQUID tuned detection, conventional Faraday detection, and the Nyquist noise generated by conducting biological samples. A second-generation microtesla MRI system employing a low-noise SQUID is constructed to increase SNR. A 2.4-m cubic, eddy-current shield with 6-mm thick aluminum walls encloses the experiment to attenuate external noise. The measured noise is 0.75 fT Hz-1/2 referred to the bottom gradiometer loop. Solenoids wound from 30-strand braided wire to decrease Nyquist noise and cooled by either liquid nitrogen or water polarize the spins. Copper wire coils wound on wooden supports produce the imaging magnetic fields and field gradients. Water phantom images with 0.8 x 0.8 x 10 mm3 resolution have a SNR of 6. Three-dimensional 1.6 x 1.9 x 14 mm3 images of bell peppers and 3 x 3 x 26 mm3 in vivo images of the human arm are presented. Since contrast based on the transverse spin relaxation rate (T1) is enhanced at low magnetic fields, microtesla MRI could potentially be used for tumor imaging. The

  14. Advanced Pediatric Brain Imaging Research Program

    Science.gov (United States)

    2016-10-01

    pediatric magnetic resonance imaging ( MRI ) techniques are revolutionizing our understanding of brain injury, its potential for recovery, and...training program, advanced MRI , brain injury. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE...is located at www.MilitaryMedED.com. The site can be accessed from any device web browser (personal computer, tablet or phone) and operating system

  15. Apparatus for minimizing radiation exposure and improving resolution in radiation imaging devices

    International Nuclear Information System (INIS)

    Ashe, J.B.; Williams, G.H.; Sypal, K.L.

    1978-01-01

    A collimator is disclosed for minimizing radiation exposure and improving resolution in radiation imaging devices. The collimator provides a penetrating beam of radiation from a source thereof, which beam is substantially non-diverging in at least one direction. In the preferred embodiment, the collimator comprises an elongated sandwich assembly of a plurality of layers of material exhibiting relatively high radiation attenuation characteristics, which attenuating layers are spaced apart and separated from one another by interleaved layers of material exhibiting relatively low radiation attenuation characteristics. The sandwich assembly is adapted for lengthwise disposition and orientation between a radiation source and a target or receiver such that the attenuating layers are parallel to the desired direction of the beam with the interleaved spacing layers providing direct paths for the radiation

  16. Proof of Concept: Design and Initial Evaluation of a Device to Measure Gastrointestinal Transit Time.

    Science.gov (United States)

    Wagner, Robert H; Savir-Baruch, Bital; Halama, James R; Venu, Mukund; Gabriel, Medhat S; Bova, Davide

    2017-09-01

    Chronic constipation and gastrointestinal motility disorders constitute a large part of a gastroenterology practice and have a significant impact on a patient's quality of life and lifestyle. In most cases, medications are prescribed to alleviate symptoms without there being an objective measurement of response. Commonly used investigations of gastrointestinal transit times are currently limited to radiopaque markers or electronic capsules. Repeated use of these techniques is limited because of the radiation exposure and the significant cost of the devices. We present the proof of concept for a new device to measure gastrointestinal transit time using commonly available and inexpensive materials with only a small amount of radiotracer. Methods: We assembled gelatin capsules containing a 67 Ga-citrate-radiolabeled grain of rice embedded in paraffin for use as a point-source transit device. It was tested for stability in vitro and subsequently was given orally to 4 healthy volunteers and 10 patients with constipation or diarrhea. Imaging was performed at regular intervals until the device was excreted. Results: The device remained intact and visible as a point source in all subjects until excretion. When used along with a diary of bowel movement times and dates, the device could determine the total transit time. The device could be visualized either alone or in combination with a barium small-bowel follow-through study or a gastric emptying study. Conclusion: The use of a point-source transit device for the determination of gastrointestinal transit time is a feasible alternative to other methods. The device is inexpensive and easy to assemble, requires only a small amount of radiotracer, and remains inert throughout the gastrointestinal tract, allowing for accurate determination of gastrointestinal transit time. Further investigation of the device is required to establish optimum imaging parameters and reference values. Measurements of gastrointestinal transit time

  17. Development of a daily dosimetric control for radiation therapy using an electronic portal imaging device (EPID)

    International Nuclear Information System (INIS)

    Saboori, Mohammadsaeed

    2015-01-01

    Electronic Portal Imaging Devices (EPIDs) can be used to perform dose measurements during radiation therapy treatments if dedicated calibration and correction procedures are applied. The purpose of this study was to provide a new calibration and correction model for an amorphous silicon (a-Si) EPID for use in transit dose verification of step-and-shoot intensity modulated radiation therapy (IMRT). A model was created in a commercial treatment planning system to calculate the nominal two-dimensional (2D) dose map of each radiation field at the EPID level. The EPID system was calibrated and correction factors were determined using a reference set-up, which consisted a patient phantom and an EPID phantom. The advantage of this method is that for the calibration, the actual beam spectrum is used to mimic a patient measurement. As proof-of-principle, the method was tested for the verification of two 7-field IMRT treatment plans with tumor sites in the head-and-neck and pelvic region. Predicted and measured EPID responses were successfully compared to the nominal data from treatment planning using dose difference maps and gamma analyses. Based on our result it can be concluded that this new method of 2D EPID dosimetry is a potential tool for simple patient treatment fraction dose verification.

  18. Optical tests for using smartphones inside medical devices

    Science.gov (United States)

    Bernat, Amir S.; Acobas, Jennifer K.; Phang, Ye Shang; Hassan, David; Bolton, Frank J.; Levitz, David

    2018-02-01

    Smartphones are currently used in many medical applications and are more frequently being integrated into medical imaging devices. The regulatory requirements in existence today however, particularly the standardization of smartphone imaging through validation and verification testing, only partially cover imaging characteristics with a smartphone. Specifically, it has been shown that smartphone camera specifications are of sufficient quality for medical imaging, and there are devices which comply with the FDA's regulatory requirements for a medical device such as a device's field of view, direction of viewing and optical resolution and optical distortion. However, these regulatory requirements do not call specifically for color testing. Images of the same object using automatic settings or different light sources can show different color composition. Experimental results showing such differences are presented. Under some circumstances, such differences in color composition could potentially lead to incorrect diagnoses. It is therefore critical to control the smartphone camera and illumination parameters properly. This paper examines different smartphone camera settings that affect image quality and color composition. To test and select the correct settings, a test methodology is proposed. It aims at evaluating and testing image color correctness and white balance settings for mobile phones and LED light sources. Emphasis is placed on color consistency and deviation from gray values, specifically by evaluating the ΔC values based on the CIEL*a*b* color space. Results show that such standardization minimizes differences in color composition and thus could reduce the risk of a wrong diagnosis.

  19. The mobile image quality survey game

    Science.gov (United States)

    Rasmussen, D. René

    2012-01-01

    In this paper we discuss human assessment of the quality of photographic still images, that are degraded in various manners relative to an original, for example due to compression or noise. In particular, we examine and present results from a technique where observers view images on a mobile device, perform pairwise comparisons, identify defects in the images, and interact with the display to indicate the location of the defects. The technique measures the response time and accuracy of the responses. By posing the survey in a form similar to a game, providing performance feedback to the observer, the technique attempts to increase the engagement of the observers, and to avoid exhausting observers, a factor that is often a problem for subjective surveys. The results are compared with the known physical magnitudes of the defects and with results from similar web-based surveys. The strengths and weaknesses of the technique are discussed. Possible extensions of the technique to video quality assessment are also discussed.

  20. Surge protective device response to steep front transient in low voltage circuit

    Energy Technology Data Exchange (ETDEWEB)

    Marcuz, J.; Binczak, S.; Bilbault, J.M. [Universite de Bourgogne, Dijon (France)], Emails: jerome.marcuz@ laposte.net, stbinc@u-bourgogne.fr, bilbault@u-bourgogne.fr; Girard, F. [ADEE Electronic, Pont de Pany (France)

    2007-07-01

    Surge propagation on cables of electrical or data lines leads to a major protection problem as the number of equipment based on solid-state circuits or microprocessors increases. Sub-microsecond components of real surge waveform has to be taken into account for a proper protection even in the case of surges caused by indirect lightning effects. The response of a model of transient voltage suppressor diode based surge protection device (SPD) to fast front transient is analytically studied, then compared to simulations, including the lines connected to the SPD and to the protected equipment. (author)

  1. Near Real-Time Georeference of Umanned Aerial Vehicle Images for Post-Earthquake Response

    Science.gov (United States)

    Wang, S.; Wang, X.; Dou, A.; Yuan, X.; Ding, L.; Ding, X.

    2018-04-01

    The rapid collection of Unmanned Aerial Vehicle (UAV) remote sensing images plays an important role in the fast submitting disaster information and the monitored serious damaged objects after the earthquake. However, for hundreds of UAV images collected in one flight sortie, the traditional data processing methods are image stitching and three-dimensional reconstruction, which take one to several hours, and affect the speed of disaster response. If the manual searching method is employed, we will spend much more time to select the images and the find images do not have spatial reference. Therefore, a near-real-time rapid georeference method for UAV remote sensing disaster data is proposed in this paper. The UAV images are achieved georeference combined with the position and attitude data collected by UAV flight control system, and the georeferenced data is organized by means of world file which is developed by ESRI. The C # language is adopted to compile the UAV images rapid georeference software, combined with Geospatial Data Abstraction Library (GDAL). The result shows that it can realize rapid georeference of remote sensing disaster images for up to one thousand UAV images within one minute, and meets the demand of rapid disaster response, which is of great value in disaster emergency application.

  2. NEAR REAL-TIME GEOREFERENCE OF UMANNED AERIAL VEHICLE IMAGES FOR POST-EARTHQUAKE RESPONSE

    Directory of Open Access Journals (Sweden)

    S. Wang

    2018-04-01

    Full Text Available The rapid collection of Unmanned Aerial Vehicle (UAV remote sensing images plays an important role in the fast submitting disaster information and the monitored serious damaged objects after the earthquake. However, for hundreds of UAV images collected in one flight sortie, the traditional data processing methods are image stitching and three-dimensional reconstruction, which take one to several hours, and affect the speed of disaster response. If the manual searching method is employed, we will spend much more time to select the images and the find images do not have spatial reference. Therefore, a near-real-time rapid georeference method for UAV remote sensing disaster data is proposed in this paper. The UAV images are achieved georeference combined with the position and attitude data collected by UAV flight control system, and the georeferenced data is organized by means of world file which is developed by ESRI. The C # language is adopted to compile the UAV images rapid georeference software, combined with Geospatial Data Abstraction Library (GDAL. The result shows that it can realize rapid georeference of remote sensing disaster images for up to one thousand UAV images within one minute, and meets the demand of rapid disaster response, which is of great value in disaster emergency application.

  3. CT perfusion imaging in response assessment of pulmonary metastases undergoing stereotactic ablative radiotherapy

    International Nuclear Information System (INIS)

    Sawyer, Brooke; Pun, Emma; Tay, Huilee; Kron, Tomas; Bressel, Mathias; Ball, David; Siva, Shankar; Samuel, Michael

    2015-01-01

    Stereotactic ablative body radiotherapy (SABR) is an emerging treatment technique for pulmonary metastases in which conventional Response Evaluation Criteria in Solid Tumours (RECIST) may be inadequate. This study aims to assess the utility of CT perfusion imaging in response assessment of pulmonary metastases after SABR. In this ethics board-approved prospective study, 11 patients underwent a 26-Gy single fraction of SABR to pulmonary metastases. CT perfusion imaging occurred prior to and at 14 and 70 days post-SABR. Blood flow (mL/100 mL/min), blood volume (mL/100 mL), time to peak (seconds) and surface permeability (mL/100 mL/min), perfusion parameters of pulmonary metastases undergoing SABR, were independently assessed by two radiologists. Inter-observer variability was analysed. CT perfusion results were analysed for early response assessment comparing day 14 with baseline scans and for late response by comparing day 70 with baseline scans. The largest diameter of the pulmonary metastases undergoing SABR was recorded. Ten patients completed all three scans and one patient had baseline and early response assessment CT perfusion scans only. There was strong level of inter-observer agreement of CT perfusion interpretation with a median intraclass coefficient of 0.87 (range 0.20–0.98). Changes in all four perfusion parameters and tumour sizes were not statistically significant. CT perfusion imaging of pulmonary metastases is a highly reproducible imaging technique that may provide additional response assessment information above that of conventional RECIST, and it warrants further study in a larger cohort of patients undergoing SABR.

  4. Modelling the perceptual similarity of facial expressions from image statistics and neural responses.

    Science.gov (United States)

    Sormaz, Mladen; Watson, David M; Smith, William A P; Young, Andrew W; Andrews, Timothy J

    2016-04-01

    The ability to perceive facial expressions of emotion is essential for effective social communication. We investigated how the perception of facial expression emerges from the image properties that convey this important social signal, and how neural responses in face-selective brain regions might track these properties. To do this, we measured the perceptual similarity between expressions of basic emotions, and investigated how this is reflected in image measures and in the neural response of different face-selective regions. We show that the perceptual similarity of different facial expressions (fear, anger, disgust, sadness, happiness) can be predicted by both surface and feature shape information in the image. Using block design fMRI, we found that the perceptual similarity of expressions could also be predicted from the patterns of neural response in the face-selective posterior superior temporal sulcus (STS), but not in the fusiform face area (FFA). These results show that the perception of facial expression is dependent on the shape and surface properties of the image and on the activity of specific face-selective regions. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Non-destructive failure analysis and measurement for molded devices and complex assemblies with X-ray CT and 3D image processing techniques

    International Nuclear Information System (INIS)

    Yin, Xiaoming; Liew, Seaw Jia; Jiang, Ting Ying; Xu, Jian; Kakarala, Ramakrishna

    2013-01-01

    In both automotive and healthcare sectors, reliable failure analysis and accurate measurement of molded devices and complex assemblies are important. Current methods of failure analysis and measurement require these molded parts to be cross-sectioned so that internal features or dimensions can be accessible. As a result, the parts are deemed unusable and additional failure introduced by sectioning may cause misinterpretation of the results. X-ray CT and 3D image processing techniques provide a new nondestructive solution for failure analysis and measurement of molded devices and complex assemblies. These techniques simplify failure analysis and measurement of molded devices and assemblies, and improve the productivity of molding manufacturing significantly.

  6. Neoadjuvant chemotherapy for breast cancer: correlation between the baseline MR imaging findings and responses to therapy

    International Nuclear Information System (INIS)

    Uematsu, Takayoshi; Yuen, Sachiko; Kasami, Masako

    2010-01-01

    To retrospectively evaluate the magnetic resonance (MR) imaging findings of breast cancer before neoadjuvant chemotherapy (NAC) and to compare findings of chemosensitive breast cancer with those of chemoresistant breast cancer. The MR imaging findings before NAC in 120 women undergoing NAC were reviewed. The MR imaging findings were compared with the pathological findings and responses. A complete response (pCR) and marked response were achieved in 12 and 35% of 120 breast cancers in 120 women respectively. Breast cancers with a pCR or marked response were classified as chemosensitive breast cancer. The remaining 64 breast cancers (53%) were classified as chemoresistant breast cancer. Large tumour size, a lesion without mass effect, and very high intratumoural signal intensity on T2-weighted MR images were significantly associated with chemoresistant breast cancer. Lesions with mass effect and washout enhancement pattern were significantly associated with chemosensitive breast cancer. Areas with very high intratumoural signal intensity on T2-weighted images corresponded pathologically to areas of intratumoural necrosis. Several MR imaging features of breast cancer before NAC can help predict the efficacy of NAC. (orig.)

  7. Neoadjuvant chemotherapy for breast cancer: correlation between the baseline MR imaging findings and responses to therapy

    Energy Technology Data Exchange (ETDEWEB)

    Uematsu, Takayoshi; Yuen, Sachiko [Shizuoka Cancer Center Hospital, Breast Imaging and Breast Intervention Section, Naga-izumi, Shizuoka (Japan); Kasami, Masako [Shizuoka Cancer Center Hospital, Department of Pathology, Naga-izumi, Shizuoka (Japan)

    2010-10-15

    To retrospectively evaluate the magnetic resonance (MR) imaging findings of breast cancer before neoadjuvant chemotherapy (NAC) and to compare findings of chemosensitive breast cancer with those of chemoresistant breast cancer. The MR imaging findings before NAC in 120 women undergoing NAC were reviewed. The MR imaging findings were compared with the pathological findings and responses. A complete response (pCR) and marked response were achieved in 12 and 35% of 120 breast cancers in 120 women respectively. Breast cancers with a pCR or marked response were classified as chemosensitive breast cancer. The remaining 64 breast cancers (53%) were classified as chemoresistant breast cancer. Large tumour size, a lesion without mass effect, and very high intratumoural signal intensity on T2-weighted MR images were significantly associated with chemoresistant breast cancer. Lesions with mass effect and washout enhancement pattern were significantly associated with chemosensitive breast cancer. Areas with very high intratumoural signal intensity on T2-weighted images corresponded pathologically to areas of intratumoural necrosis. Several MR imaging features of breast cancer before NAC can help predict the efficacy of NAC. (orig.)

  8. Development of nanomanipulator using a high-speed atomic force microscope coupled with a haptic device

    International Nuclear Information System (INIS)

    Iwata, F.; Ohashi, Y.; Ishisaki, I.; Picco, L.M.; Ushiki, T.

    2013-01-01

    The atomic force microscope (AFM) has been widely used for surface fabrication and manipulation. However, nanomanipulation using a conventional AFM is inefficient because of the sequential nature of the scan-manipulation scan cycle, which makes it difficult for the operator to observe the region of interest and perform the manipulation simultaneously. In this paper, a nanomanipulation technique using a high-speed atomic force microscope (HS-AFM) is described. During manipulation using the AFM probe, the operation is periodically interrupted for a fraction of a second for high-speed imaging that allows the topographical image of the manipulated surface to be periodically updated. With the use of high-speed imaging, the interrupting time for imaging can be greatly reduced, and as a result, the operator almost does not notice the blink time of the interruption for imaging during the manipulation. This creates a more intuitive interface with greater feedback and finesse to the operator. Nanofabrication under real-time monitoring was performed to demonstrate the utility of this arrangement for real-time nanomanipulation of sample surfaces under ambient conditions. Furthermore, the HS-AFM is coupled with a haptic device for the human interface, enabling the operator to move the HS-AFM probe to any position on the surface while feeling the response from the surface during the manipulation. - Highlights: • A nanomanipulater based on a high-speed atomic force microscope was developped. • High-speed imaging provides a valuable feedback during the manipulation operation. • Operator can feel the response from the surface via a haptic device during manipulation. • Nanofabrications under real-time monitoring were successfully performed

  9. Image Quality of the 3 Dimensional Phase-Contrast Technique in an Intracranial Magnetic Resonance Angiography with Artifacts Caused by Orthodontic Devices: A Comparison with 3 Dimensional Time-of-Flight Technique

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Seong Jin; Kim, Young Soo; Hong, Hyun Sook [Dept. of Radiology, Soonchunhyang University College of Medicine, Bucheon (Korea, Republic of); Kim, Dong Hun [Dept. of Radiology, Chosun University School of Medicine, Kwangju (Korea, Republic of)

    2011-07-15

    To evaluate the degree of image distortion caused by orthodontic devices during a intracranial magnetic resonance angiography (MRA), and to determine the effectiveness of the 3 dimensional phase-contrast (3D PC). Subjects were divided into group A (n = 20) wearing a home-made orthodontic device, and group B (n = 10) with an actual orthodontic device. A 3.0T MR scanner was used, applying 3D time-of-flight (TOF) and 3D PC. Two board-certified radiologists evaluated images independently based on a four point scale classifying segments of the circle of Willis. Magnetic susceptibility variations and contrast-to-noise ratio (CNR) on maximum intensity projection images were measured. In group A, scores of the 3D TOF and 3D PC were 2.84 {+-} 0.1 vs. 2.88 {+-} 0.1 (before) and 1.8 {+-} 0.4 vs 2.83 {+-} 0.1 (after wearing device), respectively. In group B, the scores of 3D TOF and 3D PC were 1.86 {+-} 0.43 and 2.81 {+-} 0.15 (p = 0.005), respectively. Magnetic susceptibility variations showed meaningful results after wearing the device (p = 0.0001). CNRs of the 3D PC before and after wearing device were 142.9 {+-} 6.6 vs. 140.8 {+-} 7.2 (p = 0.7507), respectively. In the 3D TOF, CNRs were 324.8 {+-} 25.4 vs. 466.3 {+-} 41.7 (p = 0.0001). The 3D PC may be a solution method for distorted images by magnetic susceptibility in the intracranial MRA compared with 3D TOF.

  10. Engineering the temporal response of photoconductive photodetectors via selective introduction of surface trap states.

    Science.gov (United States)

    Konstantatos, Gerasimos; Levina, Larissa; Fischer, Armin; Sargent, Edward H

    2008-05-01

    Photoconductive photodetectors fabricated using simple solution-processing have recently been shown to exhibit high gains (>1000) and outstanding sensitivities ( D* > 10(13) Jones). One ostensible disadvantage of exploiting photoconductive gain is that the temporal response is limited by the release of carriers from trap states. Here we show that it is possible to introduce specific chemical species onto the surfaces of colloidal quantum dots to produce only a single, desired trap state having a carefully selected lifetime. In this way we demonstrate a device that exhibits an attractive photoconductive gain (>10) combined with a response time ( approximately 25 ms) useful in imaging. We achieve this by preserving a single surface species, lead sulfite, while eliminating lead sulfate and lead carboxylate. In doing so we preserve the outstanding sensitivity of these devices, achieving a specific detectivity of 10(12) Jones in the visible, while generating a temporal response suited to imaging applications.

  11. Role of growth temperature on the frequency response characteristics of pentacene-based organic devices

    International Nuclear Information System (INIS)

    Shao, Yayun; Zhang, Yang; He, Wenqiang; Wu, Sujuan; Zeng, Min; Zhang, Zhang; Gao, Xingsen; Lu, Xubing; Liu, J-M; Liu, Chuan; Minari, Takeo

    2015-01-01

    The ac frequency response characteristics (FRC) of organic thin film transistors and metal-insulator semiconductor diodes were highly improved by controlling the morphology and electrical characteristics of semiconducting pentacene films. The devices with films grown at 50 °C show much higher cutoff frequency and better frequency stability of flat-band voltage, as compared to those with films grown at other temperatures below or above. The improvement mainly originates from the maximum field effect carrier mobility of 0.78 cm 2 V −1 s −1 and a small metal/organic contact resistance (R c ) obtained in the optimum thin film transistors. Our results indicate growth temperature precisely tunes the film microstructure and metal/semiconductor interface, which together determine the FRC of pentacene-based organic devices. (paper)

  12. Thomas Alva Edison—battery and device innovation in response to application's needs

    Science.gov (United States)

    Salkind, Alvin J.; Israel, Paul

    Thomas Alva Edison, the most prolific inventor in North America, with over 1000 patents, was the descendant of early settlers from the Netherlands to the Hudson Valley region of New York/New Jersey. However, his genealogical trail encompasses many cities, provinces, states, and countries, including Holland, France, Scotland, New Amsterdam, New York, New Jersey, Nova Scotia, Ontario, Ohio, and Michigan. He was motivated to develop and invent in response to perceived needs of commercial devices and was the creator of the concept of an industrial research laboratory. His activities covered a wide-range of chemical, electrical, medical, metallurgical, entertainment, and communication devices and led to the creation of major worldwide industries. However, his expressed underlying concern was the "service it might give others". This presentation reviews commercial developments in comparison with the technologies and motivations of the time and is illustrated by material from the Rutgers University 'Edison Papers Project', Edison's personal notes found in the Edison Battery Factory and preserved by Professor Salkind, and records of The Electrochemical Society.

  13. Appearance detection device for fuel assembly

    International Nuclear Information System (INIS)

    Matsuoka, Toshihiro

    1998-01-01

    The prevent invention provides an appearance detection device which improves accuracy of images on a display and facilitates editing and selection of images upon detection of appearance of a reactor fuel assembly. Namely, the device of the present invention comprises (1) television cameras movable along fuel assemblies of a reactor, (2) a detection means for detecting the positions of the television cameras, (3) a convertor for converting analog image signals of the television cameras to digital image signals, (4) a memory means for sampling a predetermined portion of the images of the television camera and storing it together with the position signal obtained by the detection means and (5) a computer for selecting a plurality of images and positions from the above-mentioned means and joining them to one or a plurality of static images of the fuel assembly. At least two television cameras are disposed oppositely with each other. Then, position signals of the television cameras are designated by the stored sampling signals, and the fuel assembly at the position can be displayed quickly. It is scrolled, compressed or enlarged and formed into images. (I.S.)

  14. Biochemical analysis of force-sensitive responses using a large-scale cell stretch device.

    Science.gov (United States)

    Renner, Derrick J; Ewald, Makena L; Kim, Timothy; Yamada, Soichiro

    2017-09-03

    Physical force has emerged as a key regulator of tissue homeostasis, and plays an important role in embryogenesis, tissue regeneration, and disease progression. Currently, the details of protein interactions under elevated physical stress are largely missing, therefore, preventing the fundamental, molecular understanding of mechano-transduction. This is in part due to the difficulty isolating large quantities of cell lysates exposed to force-bearing conditions for biochemical analysis. We designed a simple, easy-to-fabricate, large-scale cell stretch device for the analysis of force-sensitive cell responses. Using proximal biotinylation (BioID) analysis or phospho-specific antibodies, we detected force-sensitive biochemical changes in cells exposed to prolonged cyclic substrate stretch. For example, using promiscuous biotin ligase BirA* tagged α-catenin, the biotinylation of myosin IIA increased with stretch, suggesting the close proximity of myosin IIA to α-catenin under a force bearing condition. Furthermore, using phospho-specific antibodies, Akt phosphorylation was reduced upon stretch while Src phosphorylation was unchanged. Interestingly, phosphorylation of GSK3β, a downstream effector of Akt pathway, was also reduced with stretch, while the phosphorylation of other Akt effectors was unchanged. These data suggest that the Akt-GSK3β pathway is force-sensitive. This simple cell stretch device enables biochemical analysis of force-sensitive responses and has potential to uncover molecules underlying mechano-transduction.

  15. Implantable optogenetic device with CMOS IC technology for simultaneous optical measurement and stimulation

    Science.gov (United States)

    Haruta, Makito; Kamiyama, Naoya; Nakajima, Shun; Motoyama, Mayumi; Kawahara, Mamiko; Ohta, Yasumi; Yamasaki, Atsushi; Takehara, Hiroaki; Noda, Toshihiko; Sasagawa, Kiyotaka; Ishikawa, Yasuyuki; Tokuda, Takashi; Hashimoto, Hitoshi; Ohta, Jun

    2017-05-01

    In this study, we have developed an implantable optogenetic device that can measure and stimulate neurons by an optical method based on CMOS IC technology. The device consist of a blue LED array for optically patterned stimulation, a CMOS image sensor for acquiring brain surface image, and eight green LEDs surrounding the CMOS image sensor for illumination. The blue LED array is placed on the CMOS image sensor. We implanted the device in the brain of a genetically modified mouse and successfully demonstrated the stimulation of neurons optically and simultaneously acquire intrinsic optical images of the brain surface using the image sensor. The integrated device can be used for simultaneously measuring and controlling neuronal activities in a living animal, which is important for the artificial control of brain functions.

  16. Easy monitoring of velocity fields in microfluidic devices using spatiotemporal image correlation spectroscopy.

    Science.gov (United States)

    Travagliati, Marco; Girardo, Salvatore; Pisignano, Dario; Beltram, Fabio; Cecchini, Marco

    2013-09-03

    Spatiotemporal image correlation spectroscopy (STICS) is a simple and powerful technique, well established as a tool to probe protein dynamics in cells. Recently, its potential as a tool to map velocity fields in lab-on-a-chip systems was discussed. However, the lack of studies on its performance has prevented its use for microfluidics applications. Here, we systematically and quantitatively explore STICS microvelocimetry in microfluidic devices. We exploit a simple experimental setup, based on a standard bright-field inverted microscope (no fluorescence required) and a high-fps camera, and apply STICS to map liquid flow in polydimethylsiloxane (PDMS) microchannels. Our data demonstrates optimal 2D velocimetry up to 10 mm/s flow and spatial resolution down to 5 μm.

  17. A cloud-based multimodality case file for mobile devices.

    Science.gov (United States)

    Balkman, Jason D; Loehfelm, Thomas W

    2014-01-01

    Recent improvements in Web and mobile technology, along with the widespread use of handheld devices in radiology education, provide unique opportunities for creating scalable, universally accessible, portable image-rich radiology case files. A cloud database and a Web-based application for radiologic images were developed to create a mobile case file with reasonable usability, download performance, and image quality for teaching purposes. A total of 75 radiology cases related to breast, thoracic, gastrointestinal, musculoskeletal, and neuroimaging subspecialties were included in the database. Breast imaging cases are the focus of this article, as they best demonstrate handheld display capabilities across a wide variety of modalities. This case subset also illustrates methods for adapting radiologic content to cloud platforms and mobile devices. Readers will gain practical knowledge about storage and retrieval of cloud-based imaging data, an awareness of techniques used to adapt scrollable and high-resolution imaging content for the Web, and an appreciation for optimizing images for handheld devices. The evaluation of this software demonstrates the feasibility of adapting images from most imaging modalities to mobile devices, even in cases of full-field digital mammograms, where high resolution is required to represent subtle pathologic features. The cloud platform allows cases to be added and modified in real time by using only a standard Web browser with no application-specific software. Challenges remain in developing efficient ways to generate, modify, and upload radiologic and supplementary teaching content to this cloud-based platform. Online supplemental material is available for this article. ©RSNA, 2014.

  18. Devices for Evaluating Imaging Systems. Chapter 15

    Energy Technology Data Exchange (ETDEWEB)

    Demirkaya, O.; Al-Mazrou, R. [Department of Biomedical Physics, King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia)

    2014-12-15

    A quality management system (QMS) has three main components: (a) Quality assurance (QA); (b) Quality improvement; (c) Quality control (QC). The aim of a QMS is to ensure that the deliverables meet the requirements set forth by the users. The deliverables can be, in general, all the services provided in a nuclear medicine department, and the diagnostic imaging services in particular. In this section, the primary focus is the diagnostic imaging equipment and images produced by them.

  19. Use of smartphones and portable media devices for quantifying human movement characteristics of gait, tendon reflex response, and Parkinson's disease hand tremor.

    Science.gov (United States)

    LeMoyne, Robert; Mastroianni, Timothy

    2015-01-01

    Smartphones and portable media devices are both equipped with sensor components, such as accelerometers. A software application enables these devices to function as a robust wireless accelerometer platform. The recorded accelerometer waveform can be transmitted wireless as an e-mail attachment through connectivity to the Internet. The implication of such devices as a wireless accelerometer platform is the experimental and post-processing locations can be placed anywhere in the world. Gait was quantified by mounting a smartphone or portable media device proximal to the lateral malleolus of the ankle joint. Attributes of the gait cycle were quantified with a considerable accuracy and reliability. The patellar tendon reflex response was quantified by using the device in tandem with a potential energy impact pendulum to evoke the patellar tendon reflex. The acceleration waveform maximum acceleration feature of the reflex response displayed considerable accuracy and reliability. By mounting the smartphone or portable media device to the dorsum of the hand through a glove, Parkinson's disease hand tremor was quantified and contrasted with significance to a non-Parkinson's disease steady hand control. With the methods advocated in this chapter, any aspect of human movement may be quantified through smartphones or portable media devices and post-processed anywhere in the world. These wearable devices are anticipated to substantially impact the biomedical and healthcare industry.

  20. Heterogeneous MEMS device assembly and integration

    Science.gov (United States)

    Topart, Patrice; Picard, Francis; Ilias, Samir; Alain, Christine; Chevalier, Claude; Fisette, Bruno; Paultre, Jacques E.; Généreux, Francis; Legros, Mathieu; Lepage, Jean-François; Laverdière, Christian; Ngo Phong, Linh; Caron, Jean-Sol; Desroches, Yan

    2014-03-01

    In recent years, smart phone applications have both raised the pressure for cost and time to market reduction, and the need for high performance MEMS devices. This trend has led the MEMS community to develop multi-die packaging of different functionalities or multi-technology (i.e. wafer) approaches to fabricate and assemble devices respectively. This paper reports on the fabrication, assembly and packaging at INO of various MEMS devices using heterogeneous assembly at chip and package-level. First, the performance of a giant (e.g. about 3 mm in diameter), electrostatically actuated beam steering mirror is presented. It can be rotated about two perpendicular axes to steer an optical beam within an angular cone of up to 60° in vector scan mode with an angular resolution of 1 mrad and a response time of 300 ms. To achieve such angular performance relative to mirror size, the microassembly was performed from sub-components fabricated from 4 different wafers. To combine infrared detection with inertial sensing, an electroplated proof mass was flip-chipped onto a 256×1 pixel uncooled bolometric FPA and released using laser ablation. In addition to the microassembly technology, performance results of packaged devices are presented. Finally, to simulate a 3072×3 pixel uncooled detector for cloud and fire imaging in mid and long-wave IR, the staggered assembly of six 512×3 pixel FPAs with a less than 50 micron pixel co-registration is reported.

  1. Initial Clinical Experience Performing Patient Treatment Verification With an Electronic Portal Imaging Device Transit Dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Sean L., E-mail: BerryS@MSKCC.org [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York (United States); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Polvorosa, Cynthia; Cheng, Simon; Deutsch, Israel; Chao, K. S. Clifford; Wuu, Cheng-Shie [Department of Radiation Oncology, Columbia University, New York, New York (United States)

    2014-01-01

    Purpose: To prospectively evaluate a 2-dimensional transit dosimetry algorithm's performance on a patient population and to analyze the issues that would arise in a widespread clinical adoption of transit electronic portal imaging device (EPID) dosimetry. Methods and Materials: Eleven patients were enrolled on the protocol; 9 completed and were analyzed. Pretreatment intensity modulated radiation therapy (IMRT) patient-specific quality assurance was performed using a stringent local 3%, 3-mm γ criterion to verify that the planned fluence had been appropriately transferred to and delivered by the linear accelerator. Transit dosimetric EPID images were then acquired during treatment and compared offline with predicted transit images using a global 5%, 3-mm γ criterion. Results: There were 288 transit images analyzed. The overall γ pass rate was 89.1% ± 9.8% (average ± 1 SD). For the subset of images for which the linear accelerator couch did not interfere with the measurement, the γ pass rate was 95.7% ± 2.4%. A case study is presented in which the transit dosimetry algorithm was able to identify that a lung patient's bilateral pleural effusion had resolved in the time between the planning CT scan and the treatment. Conclusions: The EPID transit dosimetry algorithm under consideration, previously described and verified in a phantom study, is feasible for use in treatment delivery verification for real patients. Two-dimensional EPID transit dosimetry can play an important role in indicating when a treatment delivery is inconsistent with the original plan.

  2. Contrast-enhanced MR imaging monitoring of acute tumor response to chemotherapy

    International Nuclear Information System (INIS)

    Ranney, D.F.; Cohen, J.M.; Antich, P.P.; Endman, W.A.; Kulkarni, P.; Weinreb, J.C.; Giovanella, B.

    1987-01-01

    Treatment responses of human malignant melanomas were monitored at millimeter resolution in athymic mice by injecting a new polymeric contrast agent, Gd-DTPA-dextran (0.1 mmol Gd/kg, intravenously). Proton MR imaging (0.35 T, spin-echo, repetition time = 0.5 second, echo time = 50 msec) was performed 30 hours after administering diphtheria toxin. Pre-contrast medium images revealed only homogeneous intermediate-intensity tumor masses. Post-contrast medium images of untreated (viable) tumors demonstrated 32% enhancement throughout the entire mass. Post-contrast medium images of toxin-treated tumors revealed marked enhancement (65%) of the histologically viable outer rims, lesser enhancement (38%) of heavily damaged subregions, and no enhancement of dead tumor. These acute, contrast medium-enhanced MR images accurately identified tumor subregions that survived for longer than one week

  3. Markerless registration for image guided surgery. Preoperative image, intraoperative video image, and patient

    International Nuclear Information System (INIS)

    Kihara, Tomohiko; Tanaka, Yuko

    1998-01-01

    Real-time and volumetric acquisition of X-ray CT, MR, and SPECT is the latest trend of the medical imaging devices. A clinical challenge is to use these multi-modality volumetric information complementary on patient in the entire diagnostic and surgical processes. The intraoperative image and patient integration intents to establish a common reference frame by image in diagnostic and surgical processes. This provides a quantitative measure during surgery, for which we have been relied mostly on doctors' skills and experiences. The intraoperative image and patient integration involves various technologies, however, we think one of the most important elements is the development of markerless registration, which should be efficient and applicable to the preoperative multi-modality data sets, intraoperative image, and patient. We developed a registration system which integrates preoperative multi-modality images, intraoperative video image, and patient. It consists of a real-time registration of video camera for intraoperative use, a markerless surface sampling matching of patient and image, our previous works of markerless multi-modality image registration of X-ray CT, MR, and SPECT, and an image synthesis on video image. We think these techniques can be used in many applications which involve video camera like devices such as video camera, microscope, and image Intensifier. (author)

  4. Evaluation of set-of errors in pelvic irradiation with electronic portal imaging device

    International Nuclear Information System (INIS)

    Wu Xiaoying; Zhang Zhen; Wang Wenchao; Ren Jun; Guo Xiaomei; Lu Huizhong

    2007-01-01

    Objective: Evaluate the systematic and random set-up error in the pelvic irradiation u- sing electronic portal imaging device(EPID) to provide institution-specific margin for PTV design in pelvic cancer treatment planning with 3D conformal therapy and/or IMRT. Methods: From May to August 2005, twelve patients who received pelvic irradiation, were involved in this study. CT simulations were performed and DRRs were generated as the reference images. Ant-post and lateral portal images were taken daily, and total of 244 sets of EPID images were collected for the whole group. The translational shifts along right-left, superior-inferior and anterior-posterior directions were calculated with aligning the pelvic bony structures on the DRRs and electronic portal images. The systematic and random setup errors were evaluated based on the 244 sets of data. PTV margin was assessed assuming target rotation was negligible. Results: In the right- left (R-L), superior-inferior (S-I) and anterior-posterior (A-P) directions, the maximum shifts were 9.9, 14.0 and 21.1 mm and the systematic setup errors were 0.5, 0.2 and 2.3 mm respectively. For all 244 sets of data in this study, the frequency of the shift larger than 10 mm were 0% (R-L), 1% (S-I) and 3% (A -P); and in R-L and S-I direction, 92% and 91% of the times the shift was smaller than 5 mm. However, only 79% of the times the A-P shift was less than 5 mm. Conclusions: It is suggested in this study that in order to achieve a target coverage of better than 95% of the times throughout the pelvic irradiation in our institution, a 5 mm PTV margin in right-left and superior-inferior directions is required, however, the anterior-posterior margin needs to be increased to at least 10 mm. One needs to be cautious though when applying the PTV margin derived from small sample of patient population to individual patient. (authors)

  5. Signal representation device of X-ray television introscope

    International Nuclear Information System (INIS)

    Eliseev, G.E.; Kuznetsov, G.N.; Lazakov, V.N.

    1984-01-01

    A device for representation of X-ray television introscope signals is considered. It enables to analyze the image formed from any part of the entire range of values of introscope videosignal, to shift the image along the television monitor display, to magnify two-fold any of the image fragments. The principle of operation of the processing unit is considered in detail. It permits to yank a definite part of complete signal values from the operative memory device to reproduce it on the telemonitor display in the whole range of brightness, from black to white

  6. Subcutaneous fluid collection: An imaging marker for treatment response of infectious thoracolumbar spondylodiscitis

    International Nuclear Information System (INIS)

    Kakigi, Takahide; Okada, Tomohisa; Sakai, Osamu; Iwamoto, Yoshitaka; Kubo, Soichi; Yamamoto, Akira; Togashi, Kaori

    2015-01-01

    Highlights: • No imaging marker for treatment response of spondylodiscitis (SD) has been proposed. • Volume changes of subcutaneous fluid collection (SFC) had significant correlation with changes of C-reactive protein (CRP). • SFC can be used as an imaging marker for treatment response of SD on magnetic resonance imaging (MRI). - Abstract: Purpose: To evaluate prevalence of subcutaneous fluid collection (SFC) in infectious thoracolumbar spondylodiscitis (SD) compared with control patients and to investigate correlation between volume changes of SFC and treatment response of SD. Materials and methods: This retrospective study was approved by our institutional review board. From April 2011 to March 2012, 49 patients (24 SD and 25 non-SD patients) were enrolled. Prevalence of SFC was evaluated respectively for SD and non-SD patients using magnetic resonance imaging (MRI) on the sagittal short tau inversion recovery (STIR) imaging or fat-saturated T2-weighted imaging (T2WI), and compared. In SD patients with SFC, correlation was investigated between SFC volume on the 1st MRI and initial clinical status. The same analysis was conducted also for SFC volume changes from the 1st to 2nd or last MRI. Results: SFC was found in 20 patients with SD (83.3%) and 3 non-SD patients (12%) with significant difference (p < .001). In 20 SD patients with SFC, 17 patients had follow-up MRI. For the 1st MRI, no significant correlation was found between volume of SFC and initial status of patients, including body weight, body mass index (BMI), white blood cell (WBC), and erythrocyte sedimentation rate (ESR). However, significant positive correlations were found between changes of C-reactive protein (CRP) and SFC volume from the 1st to 2nd as well as from the 1st to the last MRI (each p < .05). Conclusion: SD patients had significantly higher prevalence of SFC than non-SD patients. Volume changes of SFC had significant correlation with changes of CRP, which can be used as an imaging

  7. Subcutaneous fluid collection: An imaging marker for treatment response of infectious thoracolumbar spondylodiscitis

    Energy Technology Data Exchange (ETDEWEB)

    Kakigi, Takahide, E-mail: tkakigi@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan); Okada, Tomohisa, E-mail: tomokada@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan); Sakai, Osamu, E-mail: osamu.sakai@bmc.org [Department of Radiology, Boston Medical Center, Boston University School of Medicine, FGH Building, 3rd Floor, 820 Harrison Avenue, Boston, MA 02118 (United States); Iwamoto, Yoshitaka, E-mail: iwacame@hotmail.co.jp [Department of General Internal Medicine, Rakuwakai Otowa Hospital, 2 Otowachoinji-cho, Yamashina-ku, Kyoto 607-8062 (Japan); Kubo, Soichi, E-mail: kubo-s@mbox.kyoto-inet.or.jp [Department of Radiology, Rakuwakai Otowa Hospital, 2 Otowachoinji-cho, Yamashina-ku, Kyoto 607-8062 (Japan); Yamamoto, Akira, E-mail: yakira@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan); Togashi, Kaori, E-mail: nmdioffice@kuhp.kyoto-ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan)

    2015-07-15

    Highlights: • No imaging marker for treatment response of spondylodiscitis (SD) has been proposed. • Volume changes of subcutaneous fluid collection (SFC) had significant correlation with changes of C-reactive protein (CRP). • SFC can be used as an imaging marker for treatment response of SD on magnetic resonance imaging (MRI). - Abstract: Purpose: To evaluate prevalence of subcutaneous fluid collection (SFC) in infectious thoracolumbar spondylodiscitis (SD) compared with control patients and to investigate correlation between volume changes of SFC and treatment response of SD. Materials and methods: This retrospective study was approved by our institutional review board. From April 2011 to March 2012, 49 patients (24 SD and 25 non-SD patients) were enrolled. Prevalence of SFC was evaluated respectively for SD and non-SD patients using magnetic resonance imaging (MRI) on the sagittal short tau inversion recovery (STIR) imaging or fat-saturated T2-weighted imaging (T2WI), and compared. In SD patients with SFC, correlation was investigated between SFC volume on the 1st MRI and initial clinical status. The same analysis was conducted also for SFC volume changes from the 1st to 2nd or last MRI. Results: SFC was found in 20 patients with SD (83.3%) and 3 non-SD patients (12%) with significant difference (p < .001). In 20 SD patients with SFC, 17 patients had follow-up MRI. For the 1st MRI, no significant correlation was found between volume of SFC and initial status of patients, including body weight, body mass index (BMI), white blood cell (WBC), and erythrocyte sedimentation rate (ESR). However, significant positive correlations were found between changes of C-reactive protein (CRP) and SFC volume from the 1st to 2nd as well as from the 1st to the last MRI (each p < .05). Conclusion: SD patients had significantly higher prevalence of SFC than non-SD patients. Volume changes of SFC had significant correlation with changes of CRP, which can be used as an imaging

  8. High-Fidelity Piezoelectric Audio Device

    Science.gov (United States)

    Woodward, Stanley E.; Fox, Robert L.; Bryant, Robert G.

    2003-01-01

    ModalMax is a very innovative means of harnessing the vibration of a piezoelectric actuator to produce an energy efficient low-profile device with high-bandwidth high-fidelity audio response. The piezoelectric audio device outperforms many commercially available speakers made using speaker cones. The piezoelectric device weighs substantially less (4 g) than the speaker cones which use magnets (10 g). ModalMax devices have extreme fabrication simplicity. The entire audio device is fabricated by lamination. The simplicity of the design lends itself to lower cost. The piezoelectric audio device can be used without its acoustic chambers and thereby resulting in a very low thickness of 0.023 in. (0.58 mm). The piezoelectric audio device can be completely encapsulated, which makes it very attractive for use in wet environments. Encapsulation does not significantly alter the audio response. Its small size (see Figure 1) is applicable to many consumer electronic products, such as pagers, portable radios, headphones, laptop computers, computer monitors, toys, and electronic games. The audio device can also be used in automobile or aircraft sound systems.

  9. Physiological responses of adult rainbow trout experimentally released through a unique fish conveyance device

    Science.gov (United States)

    Mesa, Matthew G.; Gee, Lisa P.; Weiland, Lisa K.; Christiansen, Helena E.

    2013-01-01

    We assessed the physiological stress responses (i.e., plasma levels of cortisol, glucose, and lactate) of adult Rainbow Trout Oncorhynchus mykiss at selected time intervals after they had passed a distance of 15 m through a unique fish conveyance device (treatment fish) or not (controls). This device differs from traditional fish pumps in two important ways: (1) it transports objects in air, rather than pumping them from and with water; and (2) it uses a unique tube for transport that has a series of soft, deformable baffles spaced evenly apart and situated perpendicular within a rigid, but flexible outer shell. Mean concentrations of the plasma constituents never differed (P > 0.05) between control and treatment fish at 0, 1, 4, 8, or 24 h after passage, and only minor differences were apparent between the different time intervals within a group. We observed no obvious injuries on any of our fish. Our results indicate that passage through this device did not severely stress or injure fish and it may allow for the rapid and safe movement of fish at hatcheries, sorting or handling facilities, or passage obstacles.

  10. Automatic Prostate Tracking and Motion Assessment in Volumetric Modulated Arc Therapy With an Electronic Portal Imaging Device

    International Nuclear Information System (INIS)

    Azcona, Juan Diego; Li, Ruijiang; Mok, Edward; Hancock, Steven; Xing, Lei

    2013-01-01

    Purpose: To assess the prostate intrafraction motion in volumetric modulated arc therapy treatments using cine megavoltage (MV) images acquired with an electronic portal imaging device (EPID). Methods and Materials: Ten prostate cancer patients were treated with volumetric modulated arc therapy using a Varian TrueBeam linear accelerator equipped with an EPID for acquiring cine MV images during treatment. Cine MV images acquisition was scheduled for single or multiple treatment fractions (between 1 and 8). A novel automatic fiducial detection algorithm that can handle irregular multileaf collimator apertures, field edges, fast leaf and gantry movement, and MV image noise and artifacts in patient anatomy was used. All sets of images (approximately 25,000 images in total) were analyzed to measure the positioning accuracy of implanted fiducial markers and assess the prostate movement. Results: Prostate motion can vary greatly in magnitude among different patients. Different motion patterns were identified, showing its unpredictability. The mean displacement and standard deviation of the intrafraction motion was generally less than 2.0 ± 2.0 mm in each of the spatial directions. In certain patients, however, the percentage of the treatment time in which the prostate is displaced more than 5 mm from its planned position in at least 1 spatial direction was 10% or more. The maximum prostate displacement observed was 13.3 mm. Conclusion: Prostate tracking and motion assessment was performed with MV imaging and an EPID. The amount of prostate motion observed suggests that patients will benefit from its real-time monitoring. Megavoltage imaging can provide the basis for real-time prostate tracking using conventional linear accelerators

  11. Salt-Doped Polymer Light-Emitting Devices

    Science.gov (United States)

    Gautier, Bathilde

    Polymer Light-Emitting Electrochemical Cells (PLECs) are solid state devices based on the in situ electrochemical doping of the luminescent polymer and the formation of a p-n junction where light is emitted upon the application of a bias current or voltage. PLECs answer the drawbacks of polymer light-emitting diodes as they do not require an ultra-thin active layer nor are they reliant on low work function cathode materials that are air unstable. However, because of the dynamic nature of the doping, they suffer from slow response times and poor stability over time. Frozen-junction PLECs offer a solution to these drawbacks, yet they are impractical due to their sub-ambient operation temperature requirement. Our work presented henceforth aims to achieve room temperature frozen-junction PLECS. In order to do that we removed the ion solvating/transporting polymer from the active layer, resulting in a luminescent polymer combined solely with a salt sandwiched between an ITO electrode and an aluminum electrode. The resulting device was not expected to operate like a PLEC due to the absence of an ion-solvating and ion-transporting medium. However, we discovered that the polymer/salt devices could be activated by applying a large voltage bias, resulting in much higher current and luminance. More important, the activated state is quasi static. Devices based on the well-known orange-emitting polymer MEH-PPV displayed a luminance storage half-life of 150 hours when activated by forward bias (ITO biased positively with respect to the aluminum) and 200 hours when activated by reverse bias. More remarkable yet, devices based on a green co-polymer displayed no notable decay in current density or luminance even after being stored for 1200 hours at room temperature! PL imaging under UV excitation demonstrates the presence of doping. These devices are described herein along with an explanation of their operating mechanisms.

  12. Statistics of Visual Responses to Image Object Stimuli from Primate AIT Neurons to DNN Neurons.

    Science.gov (United States)

    Dong, Qiulei; Wang, Hong; Hu, Zhanyi

    2018-02-01

    Under the goal-driven paradigm, Yamins et al. ( 2014 ; Yamins & DiCarlo, 2016 ) have shown that by optimizing only the final eight-way categorization performance of a four-layer hierarchical network, not only can its top output layer quantitatively predict IT neuron responses but its penultimate layer can also automatically predict V4 neuron responses. Currently, deep neural networks (DNNs) in the field of computer vision have reached image object categorization performance comparable to that of human beings on ImageNet, a data set that contains 1.3 million training images of 1000 categories. We explore whether the DNN neurons (units in DNNs) possess image object representational statistics similar to monkey IT neurons, particularly when the network becomes deeper and the number of image categories becomes larger, using VGG19, a typical and widely used deep network of 19 layers in the computer vision field. Following Lehky, Kiani, Esteky, and Tanaka ( 2011 , 2014 ), where the response statistics of 674 IT neurons to 806 image stimuli are analyzed using three measures (kurtosis, Pareto tail index, and intrinsic dimensionality), we investigate the three issues in this letter using the same three measures: (1) the similarities and differences of the neural response statistics between VGG19 and primate IT cortex, (2) the variation trends of the response statistics of VGG19 neurons at different layers from low to high, and (3) the variation trends of the response statistics of VGG19 neurons when the numbers of stimuli and neurons increase. We find that the response statistics on both single-neuron selectivity and population sparseness of VGG19 neurons are fundamentally different from those of IT neurons in most cases; by increasing the number of neurons in different layers and the number of stimuli, the response statistics of neurons at different layers from low to high do not substantially change; and the estimated intrinsic dimensionality values at the low

  13. Differential neural responses to food images in women with bulimia versus anorexia nervosa.

    Science.gov (United States)

    Brooks, Samantha J; O'Daly, Owen G; Uher, Rudolf; Friederich, Hans-Christoph; Giampietro, Vincent; Brammer, Michael; Williams, Steven C R; Schiöth, Helgi B; Treasure, Janet; Campbell, Iain C

    2011-01-01

    Previous fMRI studies show that women with eating disorders (ED) have differential neural activation to viewing food images. However, despite clinical differences in their responses to food, differential neural activation to thinking about eating food, between women with anorexia nervosa (AN) and bulimia nervosa (BN) is not known. We compare 50 women (8 with BN, 18 with AN and 24 age-matched healthy controls [HC]) while they view food images during functional Magnetic Resonance Imaging (fMRI). In response to food (vs non-food) images, women with BN showed greater neural activation in the visual cortex, right dorsolateral prefrontal cortex, right insular cortex and precentral gyrus, women with AN showed greater activation in the right dorsolateral prefrontal cortex, cerebellum and right precuneus. HC women activated the cerebellum, right insular cortex, right medial temporal lobe and left caudate. Direct comparisons revealed that compared to HC, the BN group showed relative deactivation in the bilateral superior temporal gyrus/insula, and visual cortex, and compared to AN had relative deactivation in the parietal lobe and dorsal posterior cingulate cortex, but greater activation in the caudate, superior temporal gyrus, right insula and supplementary motor area. Women with AN and BN activate top-down cognitive control in response to food images, yet women with BN have increased activation in reward and somatosensory regions, which might impinge on cognitive control over food consumption and binge eating.

  14. Simulation of Transient Response of Ir-TES for Position-Sensitive TES with Waveform Domain Multiplexing

    Science.gov (United States)

    Minamikawa, Y.; Sato, H.; Mori, F.; Damayanthi, R. M. T.; Takahashi, H.; Ohno, M.

    2008-04-01

    We are developing a new x-ray microcalorimeter based on a superconducting transition edge sensor (TES) as an imaging sensor. Our measurement shows unique waveforms which we consider as an expression of thermal nonuniformity of TES films. This arises from the different thermal responses, so that response signal shapes would vary according to the position of the incident x-ray. This position dependency deteriorate the measured energy resolution, but with appropriate waveform analysis, this would be useful for imaging device. For more inspection, we have developed a simulation code which enables a dynamic simulation to obtain a transient response of the TES by finite differential method. Temperature and electric current distributions are calculated. As a result, we successfully obtained waveform signals. The calculated signal waveforms have similar characteristics to the measured signals. This simulation visualized the transition state of the device and will help to design better detector.

  15. Disease-responsive drug delivery: the next generation of smart delivery devices.

    Science.gov (United States)

    Wanakule, Prinda; Roy, Krishnendu

    2012-01-01

    With the advent of highly potent and cytotoxic drugs, it is increasingly critical that they be targeted and released only in cells of diseased tissues, while sparing physiologically normal neighbors. Simple ligand-based targeting of drug carriers, although promising, cannot always provide the required specificity to achieve this since often normal cells also express significant levels of the targeted receptors. Therefore, stimuli-responsive delivery systems are being explored to allow drug release from nano- and microcarriers and implantable devices, primarily in the presence of physiological or disease-specific pathophysiological signals. Designing smart biomaterials that respond to temperature or pH changes, protein and ligand binding, disease-specific degradation, e.g. enzymatic cleavage, has become an integral part of this approach. These strategies are used in combination with nano- and microparticle systems to improve delivery efficiency through several routes of administration, and with injectable or implantable systems for long term controlled release. This review focuses on recent developments in stimuli-responsive systems, their physicochemical properties, release profiles, efficacy, safety and biocompatibility, as well as future perspectives.

  16. No-reference stereoscopic image quality measurement based on generalized local ternary patterns of binocular energy response

    International Nuclear Information System (INIS)

    Zhou, Wujie; Yu, Lu

    2015-01-01

    Perceptual no-reference (NR) quality measurement of stereoscopic images has become a challenging issue in three-dimensional (3D) imaging fields. In this article, we propose an efficient binocular quality-aware features extraction scheme, namely generalized local ternary patterns (GLTP) of binocular energy response, for general-purpose NR stereoscopic image quality measurement (SIQM). More specifically, we first construct the binocular energy response of a distorted stereoscopic image with different stimuli of amplitude and phase shifts. Then, the binocular quality-aware features are generated from the GLTP of the binocular energy response. Finally, these features are mapped to the subjective quality score of the distorted stereoscopic image by using support vector regression. Experiments on two publicly available 3D databases confirm the effectiveness of the proposed metric compared with the state-of-the-art full reference and NR metrics. (paper)

  17. Effects of the Factory Reset on Mobile Devices

    Directory of Open Access Journals (Sweden)

    Riqui Schwamm

    2014-09-01

    Full Text Available Mobile devices usually provide a “factory-reset” tool to erase user-specific data from the main secondary storage. 9 Apple iPhones, 10 Android devices, and 2 BlackBerry devices were tested in the first systematic evaluation of the effectiveness of factory resets. Tests used the Cellebrite UME-36 Pro with the UFED Physical Analyzer, the Bulk Extractor open-source tool, and our own programs for extracting metadata, classifying file paths, and comparing them between images. Two phones were subjected to more detailed analysis. Results showed that many kinds of data were removed by the resets, but much user-specific configuration data was left. Android devices did poorly at removing user documents and media, and occasional surprising user data was left on all devices including photo images, audio, documents, phone numbers, email addresses, geolocation data, configuration data, and keys. A conclusion is that reset devices can still provide some useful information to a forensic investigation.

  18. Wireless device connection problems and design solutions

    Science.gov (United States)

    Song, Ji-Won; Norman, Donald; Nam, Tek-Jin; Qin, Shengfeng

    2016-09-01

    Users, especially the non-expert users, commonly experience problems when connecting multiple devices with interoperability. While studies on multiple device connections are mostly concentrated on spontaneous device association techniques with a focus on security aspects, the research on user interaction for device connection is still limited. More research into understanding people is needed for designers to devise usable techniques. This research applies the Research-through-Design method and studies the non-expert users' interactions in establishing wireless connections between devices. The "Learning from Examples" concept is adopted to develop a study focus line by learning from the expert users' interaction with devices. This focus line is then used for guiding researchers to explore the non-expert users' difficulties at each stage of the focus line. Finally, the Research-through-Design approach is used to understand the users' difficulties, gain insights to design problems and suggest usable solutions. When connecting a device, the user is required to manage not only the device's functionality but also the interaction between devices. Based on learning from failures, an important insight is found that the existing design approach to improve single-device interaction issues, such as improvements to graphical user interfaces or computer guidance, cannot help users to handle problems between multiple devices. This study finally proposes a desirable user-device interaction in which images of two devices function together with a system image to provide the user with feedback on the status of the connection, which allows them to infer any required actions.

  19. Effects of excitation intensity on the photocurrent response of thin film silicon solar modules

    Science.gov (United States)

    Kim, Q.; Shumka, A.; Trask, J.

    1986-01-01

    Photocurrent responses of amorphous thin film silicon solar modules at room temperature were studied at different excitation intensities using various monochromatic light sources. Photocurrent imaging techniques have been effectively used to locate rapidly, and non-destructively, failure and defect sites in the multilayer thin film device. Differences observed in the photocurrent response characteristics for two different cells in the same amorphous thin film silicon solar module suggest the possibility of the formation of dissimilarly active devices, even though the module is processed in the same fabrication process. Possible mechanisms are discussed.

  20. Image Quality of the 3 Dimensional Phase-Contrast Technique in an Intracranial Magnetic Resonance Angiography with Artifacts Caused by Orthodontic Devices: A Comparison with 3 Dimensional Time-of-Flight Technique

    International Nuclear Information System (INIS)

    Kang, Seong Jin; Kim, Young Soo; Hong, Hyun Sook; Kim, Dong Hun

    2011-01-01

    To evaluate the degree of image distortion caused by orthodontic devices during a intracranial magnetic resonance angiography (MRA), and to determine the effectiveness of the 3 dimensional phase-contrast (3D PC). Subjects were divided into group A (n = 20) wearing a home-made orthodontic device, and group B (n = 10) with an actual orthodontic device. A 3.0T MR scanner was used, applying 3D time-of-flight (TOF) and 3D PC. Two board-certified radiologists evaluated images independently based on a four point scale classifying segments of the circle of Willis. Magnetic susceptibility variations and contrast-to-noise ratio (CNR) on maximum intensity projection images were measured. In group A, scores of the 3D TOF and 3D PC were 2.84 ± 0.1 vs. 2.88 ± 0.1 (before) and 1.8 ± 0.4 vs 2.83 ± 0.1 (after wearing device), respectively. In group B, the scores of 3D TOF and 3D PC were 1.86 ± 0.43 and 2.81 ± 0.15 (p = 0.005), respectively. Magnetic susceptibility variations showed meaningful results after wearing the device (p = 0.0001). CNRs of the 3D PC before and after wearing device were 142.9 ± 6.6 vs. 140.8 ± 7.2 (p = 0.7507), respectively. In the 3D TOF, CNRs were 324.8 ± 25.4 vs. 466.3 ± 41.7 (p = 0.0001). The 3D PC may be a solution method for distorted images by magnetic susceptibility in the intracranial MRA compared with 3D TOF.

  1. Use of a novel percutaneous biopsy localization device: initial musculoskeletal experience

    International Nuclear Information System (INIS)

    Roberts, C.C.; Morrison, W.B.; Deely, D.M.; Zoga, A.C.; Koulouris, G.; Winalski, C.S.

    2007-01-01

    To preliminarily evaluate a new CT-biopsy guidance device, the SeeStar (Radi, Uppsala, Sweden), for use in musculoskeletal applications. The device was evaluated using an imaging phantom and in various simulated clinical biopsy situations. The phantom study was undertaken to optimize the linear metallic artifacts produced by the guidance device. The phantom and guidance device were imaged with CT after altering different imaging parameters, including field of view, filter, focal spot size, kV, mAs, slice thickness and pitch. Clinical biopsy situations were simulated for a superficial biopsy, a deep biopsy and a horizontal biopsy approach. Altering CT parameters had little effect on the subjective appearance of the linear metal artifact, which is used to plan the biopsy approach. Placement of an 18-G needle inside of the biopsy device was subjectively helpful in exaggerating the artifact. Use of this artifact could be helpful in planning biopsy approach for deep lesions or lesions near critical structures. The metal guide on the device adequately supports a standard biopsy needle, making it potentially advantageous for biopsy of superficial lesions and lesions approached from a horizontal orientation. Use of this CT-biopsy guidance device is potentially useful for musculoskeletal applications. The linear metal artifact produced by the device can help plan the biopsy approach. The device can also be useful in biopsy situations where the biopsy needle requires external support during imaging. (orig.)

  2. Molecular imaging agents for SPECT (and SPECT/CT)

    International Nuclear Information System (INIS)

    Gnanasegaran, Gopinath; Ballinger, James R.

    2014-01-01

    The development of hybrid single photon emission computed tomography/computed tomography (SPECT/CT) cameras has increased the diagnostic value of many existing single photon radiopharmaceuticals. Precise anatomical localization of lesions greatly increases diagnostic confidence in bone imaging of the extremities, infection imaging, sentinel lymph node localization, and imaging in other areas. Accurate anatomical localization is particularly important prior to surgery, especially involving the parathyroid glands and sentinel lymph node procedures. SPECT/CT plays a role in characterization of lesions, particularly in bone scintigraphy and radioiodine imaging of metastatic thyroid cancer. In the development of novel tracers, SPECT/CT is particularly important in monitoring response to therapies that do not result in an early change in lesion size. Preclinical SPECT/CT devices, which actually have spatial resolution superior to PET/CT devices, have become essential in characterization of the biodistribution and tissue kinetics of novel tracers, allowing coregistration of serial studies within the same animals, which serves both to reduce biological variability and reduce the number of animals required. In conclusion, SPECT/CT increases the utility of existing radiopharmaceuticals and plays a pivotal role in the evaluation of novel tracers. (orig.)

  3. Molecular imaging agents for SPECT (and SPECT/CT)

    Energy Technology Data Exchange (ETDEWEB)

    Gnanasegaran, Gopinath [Guy' s and St Thomas' NHS Foundation Trust, Department of Nuclear Medicine, London (United Kingdom); Ballinger, James R. [Guy' s and St Thomas' NHS Foundation Trust, Department of Nuclear Medicine, London (United Kingdom); King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom)

    2014-05-15

    The development of hybrid single photon emission computed tomography/computed tomography (SPECT/CT) cameras has increased the diagnostic value of many existing single photon radiopharmaceuticals. Precise anatomical localization of lesions greatly increases diagnostic confidence in bone imaging of the extremities, infection imaging, sentinel lymph node localization, and imaging in other areas. Accurate anatomical localization is particularly important prior to surgery, especially involving the parathyroid glands and sentinel lymph node procedures. SPECT/CT plays a role in characterization of lesions, particularly in bone scintigraphy and radioiodine imaging of metastatic thyroid cancer. In the development of novel tracers, SPECT/CT is particularly important in monitoring response to therapies that do not result in an early change in lesion size. Preclinical SPECT/CT devices, which actually have spatial resolution superior to PET/CT devices, have become essential in characterization of the biodistribution and tissue kinetics of novel tracers, allowing coregistration of serial studies within the same animals, which serves both to reduce biological variability and reduce the number of animals required. In conclusion, SPECT/CT increases the utility of existing radiopharmaceuticals and plays a pivotal role in the evaluation of novel tracers. (orig.)

  4. fMRI-compatible rehabilitation hand device

    Directory of Open Access Journals (Sweden)

    Tzika Aria

    2006-10-01

    Full Text Available Abstract Background Functional magnetic resonance imaging (fMRI has been widely used in studying human brain functions and neurorehabilitation. In order to develop complex and well-controlled fMRI paradigms, interfaces that can precisely control and measure output force and kinematics of the movements in human subjects are needed. Optimized state-of-the-art fMRI methods, combined with magnetic resonance (MR compatible robotic devices for rehabilitation, can assist therapists to quantify, monitor, and improve physical rehabilitation. To achieve this goal, robotic or mechatronic devices with actuators and sensors need to be introduced into an MR environment. The common standard mechanical parts can not be used in MR environment and MR compatibility has been a tough hurdle for device developers. Methods This paper presents the design, fabrication and preliminary testing of a novel, one degree of freedom, MR compatible, computer controlled, variable resistance hand device that may be used in brain MR imaging during hand grip rehabilitation. We named the device MR_CHIROD (Magnetic Resonance Compatible Smart Hand Interfaced Rehabilitation Device. A novel feature of the device is the use of Electro-Rheological Fluids (ERFs to achieve tunable and controllable resistive force generation. ERFs are fluids that experience dramatic changes in rheological properties, such as viscosity or yield stress, in the presence of an electric field. The device consists of four major subsystems: a an ERF based resistive element; b a gearbox; c two handles and d two sensors, one optical encoder and one force sensor, to measure the patient induced motion and force. The smart hand device is designed to resist up to 50% of the maximum level of gripping force of a human hand and be controlled in real time. Results Laboratory tests of the device indicate that it was able to meet its design objective to resist up to approximately 50% of the maximum handgrip force. The detailed

  5. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    Energy Technology Data Exchange (ETDEWEB)

    Ogami, M; Kulkarni, R; Wang, H; Reif, R; Wang, R K [University of Washington, Department of Bioengineering, Seattle, Washington 98195 (United States)

    2014-08-31

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing. (laser biophotonics)

  6. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    Science.gov (United States)

    Ogami, M.; Kulkarni, R.; Wang, H.; Reif, R.; Wang, R. K.

    2014-08-01

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing.

  7. Role of imaging in the staging and response assessment of lymphoma

    DEFF Research Database (Denmark)

    Barrington, Sally F; Mikhaeel, N George; Kostakoglu, Lale

    2014-01-01

    emission tomography (PET)–computed tomography (CT). Progress in imaging is influencing trial design and affecting clinical practice. In particular, a five-point scale to grade response using PET-CT, which can be adapted to suit requirements for early- and late-response assessment with good interobserver....... CONCLUSION: This article comprises the consensus reached to update guidance on the use of PET-CT for staging and response assessment for [18F]fluorodeoxyglucose-avid lymphomas in clinical practice and late-phase trials....

  8. Wheeled mobility device transportation safety in fixed route and demand-responsive public transit vehicles within the United States.

    Science.gov (United States)

    Frost, Karen L; van Roosmalen, Linda; Bertocci, Gina; Cross, Douglas J

    2012-01-01

    An overview of the current status of wheelchair transportation safety in fixed route and demand-responsive, non-rail, public transportation vehicles within the US is presented. A description of each mode of transportation is provided, followed by a discussion of the primary issues affecting safety, accessibility, and usability. Technologies such as lifts, ramps, securement systems, and occupant restraint systems, along with regulations and voluntary industry standards have been implemented with the intent of improving safety and accessibility for individuals who travel while seated in their wheeled mobility device (e.g., wheelchair or scooter). However, across both fixed route and demand-responsive transit systems a myriad of factors such as nonuse and misuse of safety systems, oversized wheeled mobility devices, vehicle space constraints, and inadequate vehicle operator training may place wheeled mobility device (WhMD) users at risk of injury even under non-impact driving conditions. Since WhMD-related incidents also often occur during the boarding and alighting process, the frequency of these events, along with factors associated with these events are described for each transit mode. Recommendations for improving WhMD transportation are discussed given the current state of

  9. Computed tomography device

    International Nuclear Information System (INIS)

    Ohhashi, A.

    1985-01-01

    A computed tomography device comprising a subtraction unit which obtains differential data strings representing the difference between each time-serial projection data string of a group of projection data strings corresponding to a prospective reconstruction image generated by projection data strings acquired by a data acquisition system, a convolution unit which convolves each time-serial projection data string of the group of projection data strings corresponding to the prospective reconstruction image, and a back-projection unit which back-projects the convolved data strings

  10. Computer-aided breast MR image feature analysis for prediction of tumor response to chemotherapy

    International Nuclear Information System (INIS)

    Aghaei, Faranak; Tan, Maxine; Liu, Hong; Zheng, Bin; Hollingsworth, Alan B.; Qian, Wei

    2015-01-01

    Purpose: To identify a new clinical marker based on quantitative kinetic image features analysis and assess its feasibility to predict tumor response to neoadjuvant chemotherapy. Methods: The authors assembled a dataset involving breast MR images acquired from 68 cancer patients before undergoing neoadjuvant chemotherapy. Among them, 25 patients had complete response (CR) and 43 had partial and nonresponse (NR) to chemotherapy based on the response evaluation criteria in solid tumors. The authors developed a computer-aided detection scheme to segment breast areas and tumors depicted on the breast MR images and computed a total of 39 kinetic image features from both tumor and background parenchymal enhancement regions. The authors then applied and tested two approaches to classify between CR and NR cases. The first one analyzed each individual feature and applied a simple feature fusion method that combines classification results from multiple features. The second approach tested an attribute selected classifier that integrates an artificial neural network (ANN) with a wrapper subset evaluator, which was optimized using a leave-one-case-out validation method. Results: In the pool of 39 features, 10 yielded relatively higher classification performance with the areas under receiver operating characteristic curves (AUCs) ranging from 0.61 to 0.78 to classify between CR and NR cases. Using a feature fusion method, the maximum AUC = 0.85 ± 0.05. Using the ANN-based classifier, AUC value significantly increased to 0.96 ± 0.03 (p < 0.01). Conclusions: This study demonstrated that quantitative analysis of kinetic image features computed from breast MR images acquired prechemotherapy has potential to generate a useful clinical marker in predicting tumor response to chemotherapy

  11. Computer-aided breast MR image feature analysis for prediction of tumor response to chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Aghaei, Faranak; Tan, Maxine; Liu, Hong; Zheng, Bin, E-mail: Bin.Zheng-1@ou.edu [School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Hollingsworth, Alan B. [Mercy Women’s Center, Mercy Health Center, Oklahoma City, Oklahoma 73120 (United States); Qian, Wei [Department of Electrical and Computer Engineering, University of Texas, El Paso, Texas 79968 (United States)

    2015-11-15

    Purpose: To identify a new clinical marker based on quantitative kinetic image features analysis and assess its feasibility to predict tumor response to neoadjuvant chemotherapy. Methods: The authors assembled a dataset involving breast MR images acquired from 68 cancer patients before undergoing neoadjuvant chemotherapy. Among them, 25 patients had complete response (CR) and 43 had partial and nonresponse (NR) to chemotherapy based on the response evaluation criteria in solid tumors. The authors developed a computer-aided detection scheme to segment breast areas and tumors depicted on the breast MR images and computed a total of 39 kinetic image features from both tumor and background parenchymal enhancement regions. The authors then applied and tested two approaches to classify between CR and NR cases. The first one analyzed each individual feature and applied a simple feature fusion method that combines classification results from multiple features. The second approach tested an attribute selected classifier that integrates an artificial neural network (ANN) with a wrapper subset evaluator, which was optimized using a leave-one-case-out validation method. Results: In the pool of 39 features, 10 yielded relatively higher classification performance with the areas under receiver operating characteristic curves (AUCs) ranging from 0.61 to 0.78 to classify between CR and NR cases. Using a feature fusion method, the maximum AUC = 0.85 ± 0.05. Using the ANN-based classifier, AUC value significantly increased to 0.96 ± 0.03 (p < 0.01). Conclusions: This study demonstrated that quantitative analysis of kinetic image features computed from breast MR images acquired prechemotherapy has potential to generate a useful clinical marker in predicting tumor response to chemotherapy.

  12. ESR paper on the proper use of mobile devices in radiology.

    Science.gov (United States)

    2018-04-01

    Mobile devices (smartphones, tablets, etc.) have become key methods of communication, data access and data sharing for the population in the past decade. The technological capabilities of these devices have expanded very rapidly; for example, their in-built cameras have largely replaced conventional cameras. Their processing power is often sufficient to handle the large data sets of radiology studies and to manipulate images and studies directly on hand-held devices. Thus, they can be used to transmit and view radiology studies, often in locations remote from the source of the imaging data. They are not recommended for primary interpretation of radiology studies, but they facilitate sharing of studies for second opinions, viewing of studies and reports by clinicians at the bedside, etc. Other potential applications include remote participation in educational activity (e.g. webinars) and consultation of online educational content, e-books, journals and reference sources. Social-networking applications can be used for exchanging professional information and teaching. Users of mobile device must be aware of the vulnerabilities and dangers of their use, in particular regarding the potential for inappropriate sharing of confidential patient information, and must take appropriate steps to protect confidential data. • Mobile devices have revolutionized communication in the past decade, and are now ubiquitous. • Mobile devices have sufficient processing power to manipulate and display large data sets of radiological images. • Mobile devices allow transmission & sharing of radiologic studies for purposes of second opinions, bedside review of images, teaching, etc. • Mobile devices are currently not recommended as tools for primary interpretation of radiologic studies. • The use of mobile devices for image and data transmission carries risks, especially regarding confidentiality, which must be considered.

  13. Research and Development of a portable microfocus x-ray system capable of providing ultra-high resolutions images of improvised explosive devices

    International Nuclear Information System (INIS)

    Korkala, G.

    1989-01-01

    The utilization of x-ray screening has long been a recognized valuable tool as a means to evaluate and identify suspect articles for possible improvised explosive devices. Recent bombings indicate an increase in technical sophistication by the terrorist which demand additional means to further the possibility of detecting these devices before they reach their target or detonate. This paper discusses history of the use of x-ray and the design parameters of a portable micro-focus x-ray system capable of providing ultra high resolution radiographs as well as being able to be used with additional state-of-the-art imaging systems

  14. Ovarian responses and pregnancy rate with previously used intravaginal progesterone releasing devices for fixed-time artificial insemination in sheep.

    Science.gov (United States)

    Vilariño, M; Rubianes, E; Menchaca, A

    2013-01-01

    The objective was to determine serum progesterone concentrations, ovarian responses, and pregnancy rate in sheep inseminated following a short-term protocol (6 days of treatment) with a previously used controlled internal drug release-G (CIDR-G) device. In experiment 1, 30 ewes were put on a short-term protocol using a CIDR-G of first use (new devices, N = 10), second use (previously used for 6 days, N = 10), or third use (previously used twice for 6 days, N = 10). All ewes were given prostaglandin F(2α) (10 mg dinoprost) and eCG (300 IU) im at device withdrawal. Mean serum progesterone concentrations were greater for ewes treated with new versus reused devices (P synchronization and ovulation, with lower serum progesterone concentrations for reused devices. Three times used CIDR-G yielded a pregnancy rate >70%, which tended to be lower than that obtained with new devices, adding evidence of the detrimental effect of low serum progesterone concentrations on fertility in sheep. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. A biomimetic membrane device that modulates the excessive inflammatory response to sepsis.

    Directory of Open Access Journals (Sweden)

    Feng Ding

    Full Text Available OBJECTIVE: Septic shock has a clinical mortality rate approaching fifty percent. The major clinical manifestations of sepsis are due to the dysregulation of the host's response to infection rather than the direct consequences of the invading pathogen. Central to this initial immunologic response is the activation of leukocytes and microvascular endothelium resulting in cardiovascular instability, lung injury and renal dysfunction. Due to the primary role of leukocyte activation in the sepsis syndrome, a synthetic biomimetic membrane, called a selective cytopheretic device (SCD, was developed to bind activated leukocytes. The incorporation of the SCD along an extracorporeal blood circuit coupled with regional anticoagulation with citrate to lower blood ionized calcium was devised to modulate leukocyte activation in sepsis. DESIGN: Laboratory investigation. SETTING: University of Michigan Medical School. SUBJECTS: Pigs weighing 30-35 kg. INTERVENTIONS: To assess the effect of the SCD in septic shock, pigs were administered 30×10(10 bacteria/kg body weight of Escherichia coli into the peritoneal cavity and within 1 hr were immediately placed in an extracorporeal circuit containing SCD. MEASUREMENTS AND MAIN RESULTS: In this animal model, the SCD with citrate compared to control groups without the SCD or with heparin anticoagulation ameliorated the cardiovascular instability and lung sequestration of activated leukocytes, reduced renal dysfunction and improved survival time compared to various control groups. This effect was associated with minimal elevations of systemic circulating neutrophil activation. CONCLUSIONS: These preclinical studies along with two favorable exploratory clinical trials form the basis of an FDA-approved investigational device exemption for a pivotal multicenter, randomized control trial currently underway.

  16. Comparing Four Touch-Based Interaction Techniques for an Image-Based Audience Response System

    NARCIS (Netherlands)

    Jorritsma, Wiard; Prins, Jonatan T.; van Ooijen, Peter M. A.

    2015-01-01

    This study aimed to determine the most appropriate touch-based interaction technique for I2Vote, an image-based audience response system for radiology education in which users need to accurately mark a target on a medical image. Four plausible techniques were identified: land-on, take-off,

  17. Analysis of interfraction and intrafraction variation during tangential breast irradiation with an electronic portal imaging device

    International Nuclear Information System (INIS)

    Smith, Ryan P.; Bloch, Peter; Harris, Eleanor E.; McDonough, James; Sarkar, Abhirup; Kassaee, Alireza; Avery, Steven; Solin, Lawrence J.

    2005-01-01

    Purpose: To evaluate the daily setup variation and the anatomic movement of the heart and lungs during breast irradiation with tangential photon beams, as measured with an electronic portal imaging device. Methods and materials: Analysis of 1,709 portal images determined changes in the radiation field during a treatment course in 8 patients. Values obtained for every image included central lung distance (CLD) and area of lung and heart within the irradiated field. The data from these measurements were used to evaluate variation from setup between treatment days and motion due to respiration and/or patient movement during treatment delivery. Results: The effect of respiratory motion and movement during treatment was minimal: the maximum range in CLD for any patient on any day was 0.25 cm. The variation caused by day-to-day setup variation was greater, with CLD values for patients ranging from 0.59 cm to 2.94 cm. Similar findings were found for heart and lung areas. Conclusions: There is very little change in CLD and corresponding lung and heart area during individual radiation treatment fractions in breast tangential fields, compared with a relatively greater amount of variation that occurs between days

  18. Fuel inspection device

    International Nuclear Information System (INIS)

    Tsuji, Tadashi.

    1990-01-01

    The fuel inspection device of the present invention has a feature of obtaining an optimum illumination upon fuel rod interval inspection operation in a fuel pool. That is, an illumination main body used underwater is connected to a cable which is led out on a floor. A light control device is attached to the other end of the cable and an electric power cable is connected to the light control device. A light source (for example, incandescent lamp) is incorporated in the casing of the illumination main body, and a diffusion plate is disposed at the front to provide a plane light source. The light control device has a light control knob capable of remote-controlling the brightness of the light of the illumination main body. In the fuel inspection device thus constituted, halation is scarcely caused on the image screen upon inspection of fuels by a submerged type television camera to facilitate control upon inspection. Accordingly, efficiency of the fuel inspection can be improved to shorten the operation time. (I.S.)

  19. IMAGE DESCRIPTIONS FOR SKETCH BASED IMAGE RETRIEVAL

    OpenAIRE

    SAAVEDRA RONDO, JOSE MANUEL; SAAVEDRA RONDO, JOSE MANUEL

    2008-01-01

    Due to the massive use of Internet together with the proliferation of media devices, content based image retrieval has become an active discipline in computer science. A common content based image retrieval approach requires that the user gives a regular image (e.g, a photo) as a query. However, having a regular image as query may be a serious problem. Indeed, people commonly use an image retrieval system because they do not count on the desired image. An easy alternative way t...

  20. High-speed automated NDT device for niobium plate using scanning laser acoustic microscopy

    International Nuclear Information System (INIS)

    Oravecz, M.G.; Yu, B.Y.; Riney, K.; Kessler, L.W.; Padamsee, H.

    1988-01-01

    This paper presents a nondestructive testing (NDT) device which rapidly and automatically identifies defects throughout the volume of a 23.4 cm x 23.4 cm x 0.3 cm, pure niobium plate using Scanning Laser Acoustic Microscope (SLAM), high-resolution, 60 MHz, ultrasonic images. A principle advantage of the SLAM technique is that it combines a video scan rate with a high scan density (130 lines/mm at 60 MHz). To automate the inspection system they integrated under computer control the following: the SLAM RS-170/330 video output, a computerized XY plate scanner, a real-time video digitizer/integrator, a computer algorithm for defect detection, a digital mass storage device, and a hardcopy output device. The key element was development of an efficient, reliable defect detection algorithm using a variance filter with a locally determined threshold. This algorithm is responsible for recognizing valid flaws in the midst of random texture. This texture was seen throughout the acoustic images and was caused by the niobium microstructure. The images, as analyzed, contained 128 x 120 pixels with 64 grey levels per pixel. This system allows economical inspection of the large quantities (eg. 100 tons) of material needed for future particle accelerators based on microwave superconductivity. Rapid nondestructive inspection of pure niobium sheet is required because current accelerator performance is largely limited by the quality of commercially available material. Previous work documented critical flaws that are detectable by SLAM techniques. 15 references, 9 figures

  1. Online detector response calculations for high-resolution PET image reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Pratx, Guillem [Department of Radiation Oncology, Stanford University, Stanford, CA 94305 (United States); Levin, Craig, E-mail: cslevin@stanford.edu [Departments of Radiology, Physics and Electrical Engineering, and Molecular Imaging Program at Stanford, Stanford University, Stanford, CA 94305 (United States)

    2011-07-07

    Positron emission tomography systems are best described by a linear shift-varying model. However, image reconstruction often assumes simplified shift-invariant models to the detriment of image quality and quantitative accuracy. We investigated a shift-varying model of the geometrical system response based on an analytical formulation. The model was incorporated within a list-mode, fully 3D iterative reconstruction process in which the system response coefficients are calculated online on a graphics processing unit (GPU). The implementation requires less than 512 Mb of GPU memory and can process two million events per minute (forward and backprojection). For small detector volume elements, the analytical model compared well to reference calculations. Images reconstructed with the shift-varying model achieved higher quality and quantitative accuracy than those that used a simpler shift-invariant model. For an 8 mm sphere in a warm background, the contrast recovery was 95.8% for the shift-varying model versus 85.9% for the shift-invariant model. In addition, the spatial resolution was more uniform across the field-of-view: for an array of 1.75 mm hot spheres in air, the variation in reconstructed sphere size was 0.5 mm RMS for the shift-invariant model, compared to 0.07 mm RMS for the shift-varying model.

  2. Differential Neural Responses to Food Images in Women with Bulimia versus Anorexia Nervosa

    Science.gov (United States)

    Brooks, Samantha J.; O′Daly, Owen G.; Uher, Rudolf; Friederich, Hans-Christoph; Giampietro, Vincent; Brammer, Michael; Williams, Steven C. R.; Schiöth, Helgi B.; Treasure, Janet; Campbell, Iain C.

    2011-01-01

    Background Previous fMRI studies show that women with eating disorders (ED) have differential neural activation to viewing food images. However, despite clinical differences in their responses to food, differential neural activation to thinking about eating food, between women with anorexia nervosa (AN) and bulimia nervosa (BN) is not known. Methods We compare 50 women (8 with BN, 18 with AN and 24 age-matched healthy controls [HC]) while they view food images during functional Magnetic Resonance Imaging (fMRI). Results In response to food (vs non-food) images, women with BN showed greater neural activation in the visual cortex, right dorsolateral prefrontal cortex, right insular cortex and precentral gyrus, women with AN showed greater activation in the right dorsolateral prefrontal cortex, cerebellum and right precuneus. HC women activated the cerebellum, right insular cortex, right medial temporal lobe and left caudate. Direct comparisons revealed that compared to HC, the BN group showed relative deactivation in the bilateral superior temporal gyrus/insula, and visual cortex, and compared to AN had relative deactivation in the parietal lobe and dorsal posterior cingulate cortex, but greater activation in the caudate, superior temporal gyrus, right insula and supplementary motor area. Conclusions Women with AN and BN activate top-down cognitive control in response to food images, yet women with BN have increased activation in reward and somatosensory regions, which might impinge on cognitive control over food consumption and binge eating. PMID:21799807

  3. The Role of Retinal Imaging and Portable Screening Devices in Tele-ophthalmology Applications for Diabetic Retinopathy Management.

    Science.gov (United States)

    DeBuc, Delia Cabrera

    2016-12-01

    In the years since its introduction, retinal imaging has transformed our capability to visualize the posterior pole of the eye. Increasing practical advances in mobile technology, regular monitoring, and population screening for diabetic retinopathy management offer the opportunity for further development of cost-effective applications through remote assessment of the diabetic eye using portable retinal cameras, smart-phone-based devices and telemedicine networks. Numerous retinal imaging methods and mobile technologies in tele-ophthalmology applications have been reported for diabetic retinopathy screening and management. They provide several advantages of automation, sensitivity, specificity, portability, and miniaturization for the development of point-of-care diagnostics for eye complications in diabetes. The aim of this paper is to review the role of retinal imaging and mobile technologies in tele-ophthalmology applications for diabetic retinopathy screening and management. At large, although improvements in current technology and telemedicine services are still needed, telemedicine has demonstrated to be a worthy tool to support health caregivers in the effective management and prevention of diabetes and its complications.

  4. Negative Stimulus-Response Compatibility Observed with a Briefly Displayed Image of a Hand

    Science.gov (United States)

    Vainio, Lari

    2011-01-01

    Manual responses can be primed by viewing an image of a hand. The left-right identity of the viewed hand reflexively facilitates responses of the hand that corresponds to the identity. Previous research also suggests that when the response activation is triggered by an arrow, which is backward-masked and presented briefly, the activation manifests…

  5. Comparison of whole-body-imaging methods

    International Nuclear Information System (INIS)

    Rollo, F.D.; Hoffer, P.

    1977-01-01

    Currently there are four different devices that have found clinical utility in whole-body imaging. These are the rectilinear scanner, the multicrystal whole-body scanner, the Anger-type camera with a whole-body-imaging table, and the tomoscanner. In this text, the basic theory of operation and a discussion of the advantages and disadvantages in whole-body imaging is presented for each device. When applicable, a comparative assessment of the various devices is also presented. As with all else in life, there is no simple answer to the question ''which total body imaging device is best.'' Institutions with a very heavy total-body-imaging load may prefer to use an already available dual-headed rectilinear scanner system for these studies, rather than invest in a new instrument. Institutions with moderate total-body-imaging loads may wish to invest in moving table or moving camera devices which make total body imaging more convenient but retain the basic flexibility of the camera. The large-field Anger camera with or without motion offers another flexible option to these institutions. The laboratory with a very heavy total body imaging load may select efficiency over flexibility, thereby freeing up other instruments for additional studies. Finally, reliability as well as availability and quality of local service must be considered. After all, design features of an instrument become irrelevant when it is broken down and awaiting repair

  6. MR Imaging in Monitoring and Predicting Treatment Response in Multiple Sclerosis.

    Science.gov (United States)

    Río, Jordi; Auger, Cristina; Rovira, Àlex

    2017-05-01

    MR imaging is the most sensitive tool for identifying lesions in patients with multiple sclerosis (MS). MR imaging has also acquired an essential role in the detection of complications arising from these treatments and in the assessment and prediction of efficacy. In the future, other radiological measures that have shown prognostic value may be incorporated within the models for predicting treatment response. This article examines the role of MR imaging as a prognostic tool in patients with MS and the recommendations that have been proposed in recent years to monitor patients who are treated with disease-modifying drugs. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. A Review of the Research on Response to Improvised Nuclear Device Events

    Energy Technology Data Exchange (ETDEWEB)

    Bentz, A; Buddemeier, B; Dombroski, M

    2008-07-01

    Following the events of September 11, a litany of imaginable horribles was trotted out before an anxious and concerned public. To date, government agencies and academics are still grappling with how to best respond to such catastrophes, and as Senator Lieberman's quote says above, now is the time to plan and prepare for such events. One of the nation's worst fears is that terrorists might detonate an improvised nuclear device (IND) in an American city. With 9/11 serving as the catalyst, the government and many NGOs have invested money into research and development of response capabilities throughout the country. Yet, there is still much to learn about how to best respond to an IND event. Understanding the state of knowledge, identifying gaps, and making recommendations for how to fill those gaps, this paper will provide a framework under which past findings can be understood and future research can fit. The risk of an improvised nuclear device (IND) detonation may seem unlikely; and while this is hopefully true, due to its destructive capability, IND events must be prepared for. Many people still live under the Cold War mentality that if a city is attacked with a nuclear weapon, there is little chance of survival. This assumption, while perhaps true in the case of multiple, thermonuclear weapons exchanges, does not hold for the current threat. If a single IND were detonated in the United States, there would be many casualties at the point of impact; however, there would also be many survivors and the initial response by two major groups will mean the difference between life and death for many people. These groups are the first responders and the public. Understanding how these two groups prepare, react and interact will improve response to nuclear terrorism. Figure 1 provides a visualization of the response timeline of an IND event. For the purposes of this assessment, it is assumed that to accurately inform the public, three functions need to be

  8. Vibration and Noise in Magnetic Resonance Imaging of the Vocal Tract: Differences between Whole-Body and Open-Air Devices.

    Science.gov (United States)

    Přibil, Jiří; Přibilová, Anna; Frollo, Ivan

    2018-04-05

    This article compares open-air and whole-body magnetic resonance imaging (MRI) equipment working with a weak magnetic field as regards the methods of its generation, spectral properties of mechanical vibration and acoustic noise produced by gradient coils during the scanning process, and the measured noise intensity. These devices are used for non-invasive MRI reconstruction of the human vocal tract during phonation with simultaneous speech recording. In this case, the vibration and noise have negative influence on quality of speech signal. Two basic measurement experiments were performed within the paper: mapping sound pressure levels in the MRI device vicinity and picking up vibration and noise signals in the MRI scanning area. Spectral characteristics of these signals are then analyzed statistically and compared visually and numerically.

  9. Viewing sexual images is associated with reduced physiological arousal response to gambling loss.

    Science.gov (United States)

    Lui, Ming; Hsu, Ming

    2018-01-01

    Erotic imagery is one highly salient emotional signal that exists everywhere in daily life. The impact of sexual stimuli on human decision-making, however, has rarely been investigated. This study examines the impact of sexual stimuli on financial decision-making under risk. In each trial, either a sexual or neutral image was presented in a picture categorization task before a gambling task. Thirty-four men made gambling decisions while their physiological arousal, measured by skin conductance responses (SCRs), was recorded. Behaviorally, the proportion of gambling decisions did not differ between the sexual and neutral image trials. Physiologically, participants had smaller arousal differences, measured in micro-siemen per dollar, between losses and gains in the sexual rather than in the neutral image trials. Moreover, participants' SCRs to losses relative to gains predicted the proportion of gambling decisions in the neutral image trials but not in the sexual image trials. The results were consistent with the hypothesis that the presence of emotionally salient sexual images reduces attentional and arousal-related responses to gambling losses. Our results are consistent with the theory of loss attention involving increased cognitive investment in losses compared to gains. The findings also have potential practical implications for our understanding of the specific roles of sexual images in human financial decision making in everyday life, such as gambling behaviors in the casino.

  10. Digital X-ray imager

    International Nuclear Information System (INIS)

    1998-01-01

    The global objective of this cooperation was to lower the cost and improve the quality of breast health care in the United States. We planned to achieve it by designing a very high performance digital radiography unit for breast surgical specimen radiography in the operating room. These technical goals needed to be achieved at reasonable manufacturing costs to enable MedOptics to achieve high market penetration at a profit. Responsibility for overall project execution rested with MedOptics. MedOptics fabricated and demonstrated hardware, and selected components and handled the overall integration. After completion of this CRADA, MedOptics worked with collaborators to demonstrate clinical performance and utility. Finally, the company marketed the device. LLNL convened a multi-directorate expert panel for an intensive review of MedOptics point design. A written brief of panel conclusions and recommendations was prepared. In addition, LLNL was responsible for: computationally simulating the effects of varying source voltage and filtering (predicting the required dynamic range for the detector); evaluating CsI:Tl, CdWO4 and scintillating glass as image converters; recommending image enhancement algorithms. The LLNL modeling results guided the design and experimental elements of the project. The Laboratory's unique array of sources and detectors was employed to resolve specific technical questions. Our image processing expertise was applied to the selection of enhancement tools for image display

  11. MO-DE-303-03: Session on quantitative imaging for assessment of tumor response to radiation therapy

    International Nuclear Information System (INIS)

    Bowen, S.

    2015-01-01

    This session will focus on quantitative imaging for assessment of tumor response to radiation therapy. This is a technically challenging method to translate to practice in radiation therapy. In the new era of precision medicine, however, delivering the right treatment, to the right patient, and at the right time, can positively impact treatment choices and patient outcomes. Quantitative imaging provides the spatial sensitivity required by radiation therapy for precision medicine that is not available by other means. In this Joint ESTRO -AAPM Symposium, three leading-edge investigators will present specific motivations for quantitative imaging biomarkers in radiation therapy of esophageal, head and neck, locally advanced non-small cell lung cancer, and hepatocellular carcinoma. Experiences with the use of dynamic contrast enhanced (DCE) MRI, diffusion- weighted (DW) MRI, PET/CT, and SPECT/CT will be presented. Issues covered will include: response prediction, dose-painting, timing between therapy and imaging, within-therapy biomarkers, confounding effects, normal tissue sparing, dose-response modeling, and association with clinical biomarkers and outcomes. Current information will be presented from investigational studies and clinical practice. Learning Objectives: Learn motivations for the use of quantitative imaging biomarkers for assessment of response to radiation therapy Review the potential areas of application in cancer therapy Examine the challenges for translation, including imaging confounds and paucity of evidence to date Compare exemplary examples of the current state of the art in DCE-MRI, DW-MRI, PET/CT and SPECT/CT imaging for assessment of response to radiation therapy Van der Heide: Research grants from the Dutch Cancer Society and the European Union (FP7) Bowen: RSNA Scholar grant

  12. MO-DE-303-03: Session on quantitative imaging for assessment of tumor response to radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bowen, S. [University of Washington, School of Medicine: PET/CT and SPECT/CT for Lung and Liver Radiation Therapy Response Assessment of Tumor and Normal Tissue (United States)

    2015-06-15

    This session will focus on quantitative imaging for assessment of tumor response to radiation therapy. This is a technically challenging method to translate to practice in radiation therapy. In the new era of precision medicine, however, delivering the right treatment, to the right patient, and at the right time, can positively impact treatment choices and patient outcomes. Quantitative imaging provides the spatial sensitivity required by radiation therapy for precision medicine that is not available by other means. In this Joint ESTRO -AAPM Symposium, three leading-edge investigators will present specific motivations for quantitative imaging biomarkers in radiation therapy of esophageal, head and neck, locally advanced non-small cell lung cancer, and hepatocellular carcinoma. Experiences with the use of dynamic contrast enhanced (DCE) MRI, diffusion- weighted (DW) MRI, PET/CT, and SPECT/CT will be presented. Issues covered will include: response prediction, dose-painting, timing between therapy and imaging, within-therapy biomarkers, confounding effects, normal tissue sparing, dose-response modeling, and association with clinical biomarkers and outcomes. Current information will be presented from investigational studies and clinical practice. Learning Objectives: Learn motivations for the use of quantitative imaging biomarkers for assessment of response to radiation therapy Review the potential areas of application in cancer therapy Examine the challenges for translation, including imaging confounds and paucity of evidence to date Compare exemplary examples of the current state of the art in DCE-MRI, DW-MRI, PET/CT and SPECT/CT imaging for assessment of response to radiation therapy Van der Heide: Research grants from the Dutch Cancer Society and the European Union (FP7) Bowen: RSNA Scholar grant.

  13. Imaging the motion of electrons in 2D semiconductor heterostructures

    Science.gov (United States)

    Dani, Keshav

    Technological progress since the late 20th century has centered on semiconductor devices, such as transistors, diodes, and solar cells. At the heart of these devices, is the internal motion of electrons through semiconductor materials due to applied electric fields or by the excitation of photocarriers. Imaging the motion of these electrons would provide unprecedented insight into this important phenomenon, but requires high spatial and temporal resolution. Current studies of electron dynamics in semiconductors are generally limited by the spatial resolution of optical probes, or by the temporal resolution of electronic probes. In this talk, we combine femtosecond pump-probe techniques with spectroscopic photoemission electron microscopy to image the motion of photoexcited electrons from high-energy to low-energy states in a 2D InSe/GaAs heterostructure exhibiting a type-II band alignment. At the instant of photoexcitation, energy-resolved photoelectron images reveal a highly non-equilibrium distribution of photocarriers in space and energy. Thereafter, in response to the out-of-equilibrium photocarriers, we observe the spatial redistribution of charges, thus forming internal electric fields, bending the semiconductor bands, and finally impeding further charge transfer. By assembling images taken at different time-delays, we make a movie lasting a few tens of picoseconds of the electron transfer process in the photoexcited type-II heterostructure - a fundamental phenomenon in semiconductor devices like solar cells. Quantitative analysis and theoretical modeling of spatial variations in the video provide insight into future solar cells, electron dynamics in 2D materials, and other semiconductor devices.

  14. Fast Switching ITO Free Electrochromic Devices

    DEFF Research Database (Denmark)

    Jensen, Jacob; Hösel, Markus; Kim, Inyoung

    2014-01-01

    devices with a response time of 2 s for an optical contrast of 27%. The other design utilizes an embedded silver grid electrode whereupon response times of 0.5 s for a 30% optical contrast are realized when oxidizing the device. A commercially available conductive poly(3,4-ethylenedioxythiophene):poly(4...

  15. Quantitative correlational study of microbubble-enhanced ultrasound imaging and magnetic resonance imaging of glioma and early response to radiotherapy in a rat model

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chen [Department of Ultrasound, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022 (China); Lee, Dong-Hoon; Zhang, Kai; Li, Wenxiao; Zhou, Jinyuan [Division of MR Research, Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21287 (United States); Mangraviti, Antonella; Tyler, Betty [Department of Neurosurgery, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21287 (United States); Su, Lin; Zhang, Yin; Zhang, Bin; Wong, John; Wang, Ken Kang-Hsin; Velarde, Esteban; Ding, Kai, E-mail: kding1@jhmi.edu [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21231 (United States)

    2015-08-15

    Purpose: Radiotherapy remains a major treatment method for malignant tumors. Magnetic resonance imaging (MRI) is the standard modality for assessing glioma treatment response in the clinic. Compared to MRI, ultrasound imaging is low-cost and portable and can be used during intraoperative procedures. The purpose of this study was to quantitatively compare contrast-enhanced ultrasound (CEUS) imaging and MRI of irradiated gliomas in rats and to determine which quantitative ultrasound imaging parameters can be used for the assessment of early response to radiation in glioma. Methods: Thirteen nude rats with U87 glioma were used. A small thinned skull window preparation was performed to facilitate ultrasound imaging and mimic intraoperative procedures. Both CEUS and MRI with structural, functional, and molecular imaging parameters were performed at preradiation and at 1 day and 4 days postradiation. Statistical analysis was performed to determine the correlations between MRI and CEUS parameters and the changes between pre- and postradiation imaging. Results: Area under the curve (AUC) in CEUS showed significant difference between preradiation and 4 days postradiation, along with four MRI parameters, T{sub 2}, apparent diffusion coefficient, cerebral blood flow, and amide proton transfer-weighted (APTw) (all p < 0.05). The APTw signal was correlated with three CEUS parameters, rise time (r = − 0.527, p < 0.05), time to peak (r = − 0.501, p < 0.05), and perfusion index (r = 458, p < 0.05). Cerebral blood flow was correlated with rise time (r = − 0.589, p < 0.01) and time to peak (r = − 0.543, p < 0.05). Conclusions: MRI can be used for the assessment of radiotherapy treatment response and CEUS with AUC as a new technique and can also be one of the assessment methods for early response to radiation in glioma.

  16. SU-E-J-275: Review - Computerized PET/CT Image Analysis in the Evaluation of Tumor Response to Therapy

    International Nuclear Information System (INIS)

    Lu, W; Wang, J; Zhang, H

    2015-01-01

    Purpose: To review the literature in using computerized PET/CT image analysis for the evaluation of tumor response to therapy. Methods: We reviewed and summarized more than 100 papers that used computerized image analysis techniques for the evaluation of tumor response with PET/CT. This review mainly covered four aspects: image registration, tumor segmentation, image feature extraction, and response evaluation. Results: Although rigid image registration is straightforward, it has been shown to achieve good alignment between baseline and evaluation scans. Deformable image registration has been shown to improve the alignment when complex deformable distortions occur due to tumor shrinkage, weight loss or gain, and motion. Many semi-automatic tumor segmentation methods have been developed on PET. A comparative study revealed benefits of high levels of user interaction with simultaneous visualization of CT images and PET gradients. On CT, semi-automatic methods have been developed for only tumors that show marked difference in CT attenuation between the tumor and the surrounding normal tissues. Quite a few multi-modality segmentation methods have been shown to improve accuracy compared to single-modality algorithms. Advanced PET image features considering spatial information, such as tumor volume, tumor shape, total glycolytic volume, histogram distance, and texture features have been found more informative than the traditional SUVmax for the prediction of tumor response. Advanced CT features, including volumetric, attenuation, morphologic, structure, and texture descriptors, have also been found advantage over the traditional RECIST and WHO criteria in certain tumor types. Predictive models based on machine learning technique have been constructed for correlating selected image features to response. These models showed improved performance compared to current methods using cutoff value of a single measurement for tumor response. Conclusion: This review showed that

  17. SU-E-J-275: Review - Computerized PET/CT Image Analysis in the Evaluation of Tumor Response to Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lu, W; Wang, J; Zhang, H [University of Maryland School of Medicine, Baltimore, MD (United States)

    2015-06-15

    Purpose: To review the literature in using computerized PET/CT image analysis for the evaluation of tumor response to therapy. Methods: We reviewed and summarized more than 100 papers that used computerized image analysis techniques for the evaluation of tumor response with PET/CT. This review mainly covered four aspects: image registration, tumor segmentation, image feature extraction, and response evaluation. Results: Although rigid image registration is straightforward, it has been shown to achieve good alignment between baseline and evaluation scans. Deformable image registration has been shown to improve the alignment when complex deformable distortions occur due to tumor shrinkage, weight loss or gain, and motion. Many semi-automatic tumor segmentation methods have been developed on PET. A comparative study revealed benefits of high levels of user interaction with simultaneous visualization of CT images and PET gradients. On CT, semi-automatic methods have been developed for only tumors that show marked difference in CT attenuation between the tumor and the surrounding normal tissues. Quite a few multi-modality segmentation methods have been shown to improve accuracy compared to single-modality algorithms. Advanced PET image features considering spatial information, such as tumor volume, tumor shape, total glycolytic volume, histogram distance, and texture features have been found more informative than the traditional SUVmax for the prediction of tumor response. Advanced CT features, including volumetric, attenuation, morphologic, structure, and texture descriptors, have also been found advantage over the traditional RECIST and WHO criteria in certain tumor types. Predictive models based on machine learning technique have been constructed for correlating selected image features to response. These models showed improved performance compared to current methods using cutoff value of a single measurement for tumor response. Conclusion: This review showed that

  18. Study of Fish Response Using Particle Image Velocimetry and High-Speed, High-Resolution Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Zhiqun; Richmond, Marshall C.; Guensch, Gregory R.; Mueller, Robert P.

    2004-10-23

    Department of Energy's Hydropower Program, we identified three major research areas of interest: free swimming, the boundary layer over fish, and kinematic response of fish. We propose that the highest priority is to characterize the kinematic response of fish to different turbulent environments such as high shear/turbulence and hydrodynamic disturbances created by solid structures such as deflector and turbine runner blade; the next priority is to map the boundary layer over swimming fish; the last is to document the behavior of freely swimming fish, focusing on fish of our interest. Grid turbulence and Karman vortex street will be employed to map the boundary layers over fish and investigate the effects of environmental disturbances on the swimming performance of fish, because they are well established and documented in engineering literature and are representative of fish's swimming environments. Extreme conditions characteristic of turbine environments, such as strong shear environment and collision, will be investigated. Through controlled laboratory studies, the fish injury mechanism from different sources will be evaluated in isolation. The major goals are to: gain first-hand knowledge of the biological effects under such extreme hydraulic environments in which fish could lack the capability to overcome the perturbations and be vulnerable to injury; Better understand field results by integrating the laboratory studies with the responses of sensor fish device; More importantly, provide well-defined validation cases and boundary conditions for geometry-based computational fluid-structure interaction modeling in order to simulate the complex hydraulic environments in advanced hydropower systems and their effects on fish, greatly enhancing the potential to use CFD as a bio-hydraulic design alternative.

  19. NEAR REAL-TIME GEOREFERENCE OF UMANNED AERIAL VEHICLE IMAGES FOR POST-EARTHQUAKE RESPONSE

    OpenAIRE

    Wang, S.; Wang, X.; Dou, A.; Yuan, X.; Ding, L.; Ding, X.

    2018-01-01

    The rapid collection of Unmanned Aerial Vehicle (UAV) remote sensing images plays an important role in the fast submitting disaster information and the monitored serious damaged objects after the earthquake. However, for hundreds of UAV images collected in one flight sortie, the traditional data processing methods are image stitching and three-dimensional reconstruction, which take one to several hours, and affect the speed of disaster response. If the manual searching method is employed, we ...

  20. Very high frame rate volumetric integration of depth images on mobile devices.

    Science.gov (United States)

    Kähler, Olaf; Adrian Prisacariu, Victor; Yuheng Ren, Carl; Sun, Xin; Torr, Philip; Murray, David

    2015-11-01

    Volumetric methods provide efficient, flexible and simple ways of integrating multiple depth images into a full 3D model. They provide dense and photorealistic 3D reconstructions, and parallelised implementations on GPUs achieve real-time performance on modern graphics hardware. To run such methods on mobile devices, providing users with freedom of movement and instantaneous reconstruction feedback, remains challenging however. In this paper we present a range of modifications to existing volumetric integration methods based on voxel block hashing, considerably improving their performance and making them applicable to tablet computer applications. We present (i) optimisations for the basic data structure, and its allocation and integration; (ii) a highly optimised raycasting pipeline; and (iii) extensions to the camera tracker to incorporate IMU data. In total, our system thus achieves frame rates up 47 Hz on a Nvidia Shield Tablet and 910 Hz on a Nvidia GTX Titan XGPU, or even beyond 1.1 kHz without visualisation.

  1. Conditions for reliable time-resolved dosimetry of electronic portal imaging devices for fixed-gantry IMRT and VMAT

    International Nuclear Information System (INIS)

    Yeo, Inhwan Jason; Patyal, Baldev; Mandapaka, Anant; Jung, Jae Won; Yi, Byong Yong; Kim, Jong Oh

    2013-01-01

    Purpose: The continuous scanning mode of electronic portal imaging devices (EPID) that offers time-resolved information has been newly explored for verifying dynamic radiation deliveries. This study seeks to determine operating conditions (dose rate stability and time resolution) under which that mode can be used accurately for the time-resolved dosimetry of intensity-modulated radiation therapy (IMRT) beams.Methods: The authors have designed the following test beams with variable beam holdoffs and dose rate regulations: a 10 × 10 cm open beam to serve as a reference beam; a sliding window (SW) beam utilizing the motion of a pair of multileaf collimator (MLC) leaves outside the 10 × 10 cm jaw; a step and shoot (SS) beam to move the pair in step; a volumetric modulated arc therapy (VMAT) beam. The beams were designed in such a way that they all produce the same open beam output of 10 × 10 cm. Time-resolved ion chamber measurements at isocenter and time-resolved and integrating EPID measurements were performed for all beams. The time-resolved EPID measurements were evaluated through comparison with the ion chamber and integrating EPID measurements, as the latter are accepted procedures. For two-dimensional, time-resolved evaluation, a VMAT beam with an infield MLC travel was designed. Time-resolved EPID measurements and Monte Carlo calculations of such EPID dose images for this beam were performed and intercompared.Results: For IMRT beams (SW and SS), the authors found disagreement greater than 2%, caused by frame missing of the time-resolved mode. However, frame missing disappeared, yielding agreement better than 2%, when the dose rate of irradiation (and thus the frame acquisition rates) reached a stable and planned rate as the dose of irradiation was raised past certain thresholds (a minimum 12 s of irradiation per shoot used for SS IMRT). For VMAT, the authors found that dose rate does not affect the frame acquisition rate, thereby causing no frame missing

  2. Low-cost photodynamic therapy devices for global health settings: Characterization of battery-powered LED performance and smartphone imaging in 3D tumor models

    Science.gov (United States)

    Hempstead, Joshua; Jones, Dustin P.; Ziouche, Abdelali; Cramer, Gwendolyn M.; Rizvi, Imran; Arnason, Stephen; Hasan, Tayyaba; Celli, Jonathan P.

    2015-05-01

    A lack of access to effective cancer therapeutics in resource-limited settings is implicated in global cancer health disparities between developed and developing countries. Photodynamic therapy (PDT) is a light-based treatment modality that has exhibited safety and efficacy in the clinic using wavelengths and irradiances achievable with light-emitting diodes (LEDs) operated on battery power. Here we assess low-cost enabling technology to extend the clinical benefit of PDT to regions with little or no access to electricity or medical infrastructure. We demonstrate the efficacy of a device based on a 635 nm high-output LED powered by three AA disposable alkaline batteries, to achieve strong cytotoxic response in monolayer and 3D cultures of A431 squamous carcinoma cells following photosensitization by administering aminolevulinic acid (ALA) to induce the accumulation of protoporphyrin IX (PpIX). Here we characterize challenges of battery-operated device performance, including battery drain and voltage stability specifically over relevant PDT dose parameters. Further motivated by the well-established capacity of PDT photosensitizers to serve as tumour-selective fluorescence contrast agents, we demonstrate the capability of a consumer smartphone with low-cost add-ons to measure concentration-dependent PpIX fluorescence. This study lays the groundwork for the on-going development of image-guided ALA-PDT treatment technologies for global health applications.

  3. Beacon-S TM: Non-uniform attenuation correction for SPECT imaging. The new medium-energy transmission device for AXIS and IRIX

    International Nuclear Information System (INIS)

    Daniel Gagnon, D.

    1999-01-01

    The paper presents new medium-energy transmission device for SPECT imaging. Beacon-S includes a 356-keV medium energy 133 Ba source with a 10.54-year half-life. Beacon-S provide high-resolution and high-contrast transmission scans. The higher energy of the gamma substantially improves the transmission contrast for larger patients by virtue of better penetration through the body

  4. Applications of VLSI circuits to medical imaging

    International Nuclear Information System (INIS)

    O'Donnell, M.

    1988-01-01

    In this paper the application of advanced VLSI circuits to medical imaging is explored. The relationship of both general purpose signal processing chips and custom devices to medical imaging is discussed using examples of fabricated chips. In addition, advanced CAD tools for silicon compilation are presented. Devices built with these tools represent a possible alternative to custom devices and general purpose signal processors for the next generation of medical imaging systems

  5. Five Tips for Managing Mobile Devices

    Science.gov (United States)

    Tucker, Catlin

    2015-01-01

    The author, an outspoken advocate for using technology in the classroom, knows how important it is to establish expectations for responsible use of mobile devices. She's found that five strategies help ensure that mobile devices enhance, rather than distract from, learning. Teachers need to establish new norms that clarify responsible use,…

  6. Multiple-image oscilloscope camera

    International Nuclear Information System (INIS)

    Yasillo, N.J.

    1978-01-01

    An optical device for placing automatically a plurality of images at selected locations on one film comprises a stepping motor coupled to a rotating mirror and lens. A mechanical connection from the mirror controls an electronic logical system to allow rotation of the mirror to place a focused image at tge desired preselected location. The device is of especial utility when used to place four images on a single film to record oscilloscope views obtained in gamma radiography

  7. Ultrasound appearances of Implanon implanted contraceptive devices.

    LENUS (Irish Health Repository)

    McNeill, G

    2009-09-01

    Subdermal contraceptive devices represent a popular choice of contraception. Whilst often removed without the use of imaging, circumstances exist where imaging is required. Ultrasound is the modality of choice. The optimal technique and typical sonographic appearances are detailed in this article.

  8. Application of particle image velocimetry measurement techniques to study turbulence characteristics of oscillatory flows around parallel-plate structures in thermoacoustic devices

    International Nuclear Information System (INIS)

    Mao, Xiaoan; Jaworski, Artur J

    2010-01-01

    This paper describes the development of the experimental setup and measurement methodologies to study the physics of oscillatory flows in the vicinity of parallel-plate stacks by using the particle image velocimetry (PIV) techniques. Parallel-plate configurations often appear as internal structures in thermoacoustic devices and are responsible for the hydrodynamic energy transfer processes. The flow around selected stack configurations is induced by a standing acoustic wave, whose amplitude can be varied. Depending on the direction of the flow within the acoustic cycle, relative to the stack, it can be treated as an entrance flow or a wake flow. The insight into the flow behaviour, its kinematics, dynamics and scales of turbulence, is obtained using the classical Reynolds decomposition to separate the instantaneous velocity fields into ensemble-averaged mean velocity fields and fluctuations in a set of predetermined phases within an oscillation cycle. The mean velocity field and the fluctuation intensity distributions are investigated over the acoustic oscillation cycle. The velocity fluctuation is further divided into large- and small-scale fluctuations by using fast Fourier transform (FFT) spatial filtering techniques

  9. Nuclear medicine imaging to predict response to radiotherapy: a review

    International Nuclear Information System (INIS)

    Wiele, Christophe van de; Lahorte, Christophe; Oyen, Wim; Boerman, Otto; Goethals, Ingeborg; Slegers, Guido; Dierckx, Rudi Andre

    2003-01-01

    Purpose: To review available literature on positron emission tomography (PET) and single photon emission computerized tomography (SPECT) for the measurement of tumor metabolism, hypoxia, growth factor receptor expression, and apoptosis as predictors of response to radiotherapy. Methods and Materials: Medical literature databases (Pubmed, Medline) were screened for available literature and critically analyzed as to their scientific relevance. Results: Studies on 18 F-fluorodeoxyglucose PET as a predictor of response to radiotherapy in head-and-neck carcinoma are promising but need confirmation in larger series. 18 F-fluorothymine is stable in human plasma, and preliminary clinical data obtained with this marker of tumor cell proliferation are promising. For imaging tumor hypoxia, novel, more widely available radiopharmaceuticals with faster pharmacokinetics are mandatory. Imaging of ongoing apoptosis and growth factor expression is at a very early stage, but results obtained in other domains with radiolabeled peptides appear promising. Finally, for most of the tracers discussed, validation against a gold standard is needed. Conclusion: Optimization of the pharmacokinetics of relevant radiopharmaceuticals as well as validation against gold-standard tests in large patient series are mandatory if PET and SPECT are to be implemented in routine clinical practice for the purpose of predicting response to radiotherapy

  10. Combined optical/digital security devices

    Science.gov (United States)

    Girnyk, Vladimir I.; Tverdokhleb, Igor V.; Ivanovsky, Andrey A.

    2000-04-01

    Modern holographic security devices used as emblems against counterfeiting are being more difficult as they should oppress criminal world. 2D, 3D, 3D rainbow holograms or simple diffraction structures protecting documents can not be acceptable against illegal copying of important documents, banknotes or valuable products. Recent developments in technology of Optical variable devices permit world leaders to create more advanced security elements: Kinegrams, Exelgrams, Pixelgrams, Kineforms. These products are used for protecting the most confidential documents and banknotes, but now even their security level can not be enough and besides their automatic identification is vulnerable to factors of instability. We elaborate new visual security devices based on the usage of expensive and advanced technology of combined optical/digital security devices. The technology unites digital and analogue methods of synthesis and recording of visual security devices. The analogue methods include techniques of optical holography - different combinations of 2D/3D, 3D, 2D/3D + 3D structures. Basing on them the design with elements of 3D graphics including security elements and hidden machine- readable images are implemented. The digital methods provide synthesis of optical variable devices including special security elements, computer generated holograms and Kineforms. Using them we create determined and quasi-random machine-readable images. Recordings are carried out using the combined optical and electronic submicrometer technology elaborated by Optronics, Ltd. The results obtained show effectiveness of the combined technology permitting to increase the security level essentially that should increase tamper and counterfeit resistance during many years.

  11. Energy response of an imaging plate exposed to standard beta sources

    International Nuclear Information System (INIS)

    Gonzalez, A.L.; Li, H.; Mitch, M.; Tolk, N.; Duggan, D.M.

    2002-01-01

    Imaging plates (IPs) are a reusable media, which when exposed to ionizing radiation, store a latent image that can be read out with a red laser as photostimulated luminescence (PSL). They are widely used as a substitute for X-ray films for diagnostic studies. In diagnostic radiology this technology is known as computed radiography. In this work, the energy response of a commercial IP to beta-particle reference radiation fields used for calibrations at the National Institute of Standards and Technology was investigated. The absorbed dose in the active storage phosphor layer was calculated following the scaling procedure for depth dose for high Z materials with reference to water. It was found that the beta particles from Pm-147 and Kr-85 gave 68% and 24% higher PSL responses than that induced by Sr-90, respectively, which was caused by the different PSL detection efficiencies. In addition, normalized response curves of the IPs as a function of depth in polystyrene were measured and compared with the data measured using extrapolation chamber techniques. The difference between both sets of data resulted from the continuous energy change as the beta particle travels across the material, which leads to a different PSL response

  12. Multifunctional Energy Storage and Conversion Devices.

    Science.gov (United States)

    Huang, Yan; Zhu, Minshen; Huang, Yang; Pei, Zengxia; Li, Hongfei; Wang, Zifeng; Xue, Qi; Zhi, Chunyi

    2016-10-01

    Multifunctional energy storage and conversion devices that incorporate novel features and functions in intelligent and interactive modes, represent a radical advance in consumer products, such as wearable electronics, healthcare devices, artificial intelligence, electric vehicles, smart household, and space satellites, etc. Here, smart energy devices are defined to be energy devices that are responsive to changes in configurational integrity, voltage, mechanical deformation, light, and temperature, called self-healability, electrochromism, shape memory, photodetection, and thermal responsivity. Advisable materials, device designs, and performances are crucial for the development of energy electronics endowed with these smart functions. Integrating these smart functions in energy storage and conversion devices gives rise to great challenges from the viewpoint of both understanding the fundamental mechanisms and practical implementation. Current state-of-art examples of these smart multifunctional energy devices, pertinent to materials, fabrication strategies, and performances, are highlighted. In addition, current challenges and potential solutions from materials synthesis to device performances are discussed. Finally, some important directions in this fast developing field are considered to further expand their application. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Development and Application of Devices for Remote Monitoring of Gamma-Ray Contamination at RECOM Ltd

    International Nuclear Information System (INIS)

    Ivanov, O.P.; Stepanov, V.E.; Chesnokov, A.V.; Sudarkin, A.N.; Urutskoev, L.I.

    1999-01-01

    Devices for remote monitoring of gamma-ray contamination develop at RECOM Ltd. are described and typical examples of their application are show. The following devices are discussed: spectrum-sensitive collimated devices for mapping of radioactivity on contaminated surfaces- scanning collimated Gamma Locator, device for field Cs-137 contamination mapping-CORAD; devices for gamma-ray imaging computer-controlled High-Energy Radiation Visualizer (HERV) and Coded Mask Imager

  14. On line portal imaging

    International Nuclear Information System (INIS)

    Munro, Peter

    1995-01-01

    Purpose/Objective: The purpose of this presentation is to review the physics of imaging with high energy x-ray beams; examine the various imaging devices that have been developed for portal imaging; describe some of the image registration methods that have been developed to determine errors in patient positioning quantitatively; and discuss some of the ways that portal imaging has been incorporated into routine clinical practice. Verification of patient positioning has always been an important aspect of external beam radiation therapy. Checks of patient positioning have generally been done with film, however, film suffers from a number of drawbacks, such as poor image display and delays due to film development. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems, which are intended to overcome the limitations of portal films. The commercial devices can be classified into three categories: T.V. camera-based systems, liquid ionisation chamber systems, and amorphous silicon systems. Many factors influence the quality of images generated by these portal imaging systems. These include factors which are unavoidable (e.g., low subject contrast), factors which depend upon the individual imaging device forming the image (e.g., dose utilisation, spatial resolution) as well as factors which depend upon the characteristics of the linear accelerator irradiating the imaging system (x-ray source size, image magnification). The fundamental factors which limit image quality and the characteristics of individual imaging systems, such as spatial resolution, temporal response, and quantum utilisation will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same

  15. Statistical image processing and multidimensional modeling

    CERN Document Server

    Fieguth, Paul

    2010-01-01

    Images are all around us! The proliferation of low-cost, high-quality imaging devices has led to an explosion in acquired images. When these images are acquired from a microscope, telescope, satellite, or medical imaging device, there is a statistical image processing task: the inference of something - an artery, a road, a DNA marker, an oil spill - from imagery, possibly noisy, blurry, or incomplete. A great many textbooks have been written on image processing. However this book does not so much focus on images, per se, but rather on spatial data sets, with one or more measurements taken over

  16. Portable (handheld) clinical device for quantitative spectroscopy of skin, utilizing spatial frequency domain reflectance techniques

    Science.gov (United States)

    Saager, Rolf B.; Dang, An N.; Huang, Samantha S.; Kelly, Kristen M.; Durkin, Anthony J.

    2017-09-01

    Spatial Frequency Domain Spectroscopy (SFDS) is a technique for quantifying in-vivo tissue optical properties. SFDS employs structured light patterns that are projected onto tissues using a spatial light modulator, such as a digital micromirror device. In combination with appropriate models of light propagation, this technique can be used to quantify tissue optical properties (absorption, μa, and scattering, μs', coefficients) and chromophore concentrations. Here we present a handheld implementation of an SFDS device that employs line (one dimensional) imaging. This instrument can measure 1088 spatial locations that span a 3 cm line as opposed to our original benchtop SFDS system that only collects a single 1 mm diameter spot. This imager, however, retains the spectral resolution (˜1 nm) and range (450-1000 nm) of our original benchtop SFDS device. In the context of homogeneous turbid media, we demonstrate that this new system matches the spectral response of our original system to within 1% across a typical range of spatial frequencies (0-0.35 mm-1). With the new form factor, the device has tremendously improved mobility and portability, allowing for greater ease of use in a clinical setting. A smaller size also enables access to different tissue locations, which increases the flexibility of the device. The design of this portable system not only enables SFDS to be used in clinical settings but also enables visualization of properties of layered tissues such as skin.

  17. Predicting Response to Neoadjuvant Chemotherapy with PET Imaging Using Convolutional Neural Networks.

    Directory of Open Access Journals (Sweden)

    Petros-Pavlos Ypsilantis

    Full Text Available Imaging of cancer with 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET has become a standard component of diagnosis and staging in oncology, and is becoming more important as a quantitative monitor of individual response to therapy. In this article we investigate the challenging problem of predicting a patient's response to neoadjuvant chemotherapy from a single 18F-FDG PET scan taken prior to treatment. We take a "radiomics" approach whereby a large amount of quantitative features is automatically extracted from pretherapy PET images in order to build a comprehensive quantification of the tumor phenotype. While the dominant methodology relies on hand-crafted texture features, we explore the potential of automatically learning low- to high-level features directly from PET scans. We report on a study that compares the performance of two competing radiomics strategies: an approach based on state-of-the-art statistical classifiers using over 100 quantitative imaging descriptors, including texture features as well as standardized uptake values, and a convolutional neural network, 3S-CNN, trained directly from PET scans by taking sets of adjacent intra-tumor slices. Our experimental results, based on a sample of 107 patients with esophageal cancer, provide initial evidence that convolutional neural networks have the potential to extract PET imaging representations that are highly predictive of response to therapy. On this dataset, 3S-CNN achieves an average 80.7% sensitivity and 81.6% specificity in predicting non-responders, and outperforms other competing predictive models.

  18. An electronic image processing device featuring continuously selectable two-dimensional bipolar filter functions and real-time operation

    International Nuclear Information System (INIS)

    Charleston, B.D.; Beckman, F.H.; Franco, M.J.; Charleston, D.B.

    1981-01-01

    A versatile electronic-analogue image processing system has been developed for use in improving the quality of various types of images with emphasis on those encountered in experimental and diagnostic medicine. The operational principle utilizes spatial filtering which selectively controls the contrast of an image according to the spatial frequency content of relevant and non-relevant features of the image. Noise can be reduced or eliminated by selectively lowering the contrast of information in the high spatial frequency range. Edge sharpness can be enhanced by accentuating the upper midrange spatial frequencies. Both methods of spatial frequency control may be adjusted continuously in the same image to obtain maximum visibility of the features of interest. A precision video camera is used to view medical diagnostic images, either prints, transparencies or CRT displays. The output of the camera provides the analogue input signal for both the electronic processing system and the video display of the unprocessed image. The video signal input to the electronic processing system is processed by a two-dimensional spatial convolution operation. The system employs charged-coupled devices (CCDs), both tapped analogue delay lines (TADs) and serial analogue delay lines (SADs), to store information in the form of analogue potentials which are constantly being updated as new sampled analogue data arrive at the input. This information is convolved with a programmed bipolar radially symmetrical hexagonal function which may be controlled and varied at each radius by the operator in real-time by adjusting a set of front panel controls or by a programmed microprocessor control. Two TV monitors are used, one for processed image display and the other for constant reference to the original image. The working prototype has a full-screen display matrix size of 200 picture elements per horizontal line by 240 lines. The matrix can be expanded vertically and horizontally for the

  19. Reliability and responsiveness of dynamic contrast-enhanced magnetic resonance imaging in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Axelsen, M.B.; Poggenborg, R.P.; Stoltenberg, M.

    2013-01-01

    intraarticular injection with 80 mg methylprednisolone. Using semi-automated image processing software, DCE-MRI parameters, including the initial rate of enhancement (IRE) and maximal enhancement (ME), were generated for three regions of interest (ROIs): ‘Whole slice’, ‘Quick ROI’, and ‘Precise ROI......Objectives: To investigate the responsiveness to treatment and the reliability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in rheumatoid arthritis (RA) knee joints. Methods: DCE-MRI was performed in 12 clinically active RA knee joints before and 1, 7, 30, and 180 days after......’. The smallest detectable difference (SDD), the smallest detectable change (SDC), and intra- and inter-reader intraclass correlation coefficients (ICCs) were used to assess the reliability of DCE-MRI. Responsiveness to treatment was assessed by the standardized response mean (SRM). Results: In all patients...

  20. Device localization and dynamic scan plane selection using a wireless MRI detector array

    Science.gov (United States)

    Riffe, Matthew J.; Yutzy, Stephen R.; Jiang, Yun; Twieg, Michael D.; Blumenthal, Colin J.; Hsu, Daniel P.; Pan, Li; Gilson, Wesley D.; Sunshine, Jeffrey L.; Flask, Christopher A.; Duerk, Jeffrey L.; Nakamoto, Dean; Gulani, Vikas; Griswold, Mark A.

    2013-01-01

    Purpose A prototype wireless guidance device using single sideband amplitude modulation (SSB) is presented for a 1.5T MRI system. Methods The device contained three fiducial markers each mounted to an independent receiver coil equipped with wireless SSB technology. Acquiring orthogonal projections of these markers determined the position and orientation of the device, which was used to define the scan plane for a subsequent image acquisition. Device localization and scan plane update required approximately 30 ms, so it could be interleaved with high temporal resolution imaging. Since the wireless device is used for localization and doesn’t require full imaging capability, the design of the SSB wireless system was simplified by allowing an asynchronous clock between the transmitter and receiver. Results When coupled to a high readout bandwidth, the error caused by the lack of a shared frequency reference was quantified to be less than one pixel (0.78 mm) in the projection acquisitions. Image-guidance with the prototype was demonstrated with a phantom where a needle was successfully guided to a target and contrast was delivered. Conclusion The feasibility of active tracking with a wireless detector array is demonstrated. Wireless arrays could be incorporated into devices to assist in image-guided procedures. PMID:23900921

  1. Diffusion tensor and volumetric magnetic resonance imaging using an MR-compatible hand-induced robotic device suggests training-induced neuroplasticity in patients with chronic stroke.

    Science.gov (United States)

    Lazaridou, Asimina; Astrakas, Loukas; Mintzopoulos, Dionyssios; Khanicheh, Azadeh; Singhal, Aneesh B; Moskowitz, Michael A; Rosen, Bruce; Tzika, Aria A

    2013-11-01

    Stroke is the third leading cause of mortality and a frequent cause of long-term adult impairment. Improved strategies to enhance motor function in individuals with chronic disability from stroke are thus required. Post‑stroke therapy may improve rehabilitation and reduce long-term disability; however, objective methods for evaluating the specific impact of rehabilitation are rare. Brain imaging studies on patients with chronic stroke have shown evidence for reorganization of areas showing functional plasticity after a stroke. In this study, we hypothesized that brain mapping using a novel magnetic resonance (MR)-compatible hand device in conjunction with state‑of‑the‑art magnetic resonance imaging (MRI) can serve as a novel biomarker for brain plasticity induced by rehabilitative motor training in patients with chronic stroke. This hypothesis is based on the premises that robotic devices, by stimulating brain plasticity, can assist in restoring movement compromised by stroke-induced pathological changes in the brain and that these changes can then be monitored by advanced MRI. We serially examined 15 healthy controls and 4 patients with chronic stroke. We employed a combination of diffusion tensor imaging (DTI) and volumetric MRI using a 3-tesla (3T) MRI system using a 12-channel Siemens Tim coil and a novel MR-compatible hand‑induced robotic device. DTI data revealed that the number of fibers and the average tract length significantly increased after 8 weeks of hand training by 110% and 64%, respectively (probotics in the molecular medicine era.

  2. Vibration and Noise in Magnetic Resonance Imaging of the Vocal Tract: Differences between Whole-Body and Open-Air Devices

    Directory of Open Access Journals (Sweden)

    Jiří Přibil

    2018-04-01

    Full Text Available This article compares open-air and whole-body magnetic resonance imaging (MRI equipment working with a weak magnetic field as regards the methods of its generation, spectral properties of mechanical vibration and acoustic noise produced by gradient coils during the scanning process, and the measured noise intensity. These devices are used for non-invasive MRI reconstruction of the human vocal tract during phonation with simultaneous speech recording. In this case, the vibration and noise have negative influence on quality of speech signal. Two basic measurement experiments were performed within the paper: mapping sound pressure levels in the MRI device vicinity and picking up vibration and noise signals in the MRI scanning area. Spectral characteristics of these signals are then analyzed statistically and compared visually and numerically.

  3. Existential Threat or Dissociative Response? Examining Defensive Avoidance of Point-of-Care Testing Devices Through a Terror Management Theory Framework.

    Science.gov (United States)

    Dunne, Simon; Gallagher, Pamela; Matthews, Anne

    2015-01-01

    Using a terror management theory framework, this study investigated if providing mortality reminders or self-esteem threats would lead participants to exhibit avoidant responses toward a point-of-care testing device for cardiovascular disease risk and if the nature of the device served to diminish the existential threat of cardiovascular disease. One hundred and twelve participants aged 40-55 years completed an experimental questionnaire. Findings indicated that participants were not existentially threatened by established terror management methodologies, potentially because of cross-cultural variability toward such methodologies. Highly positive appraisals of the device also suggest that similar technologies may beneficially affect the uptake of screening behaviors.

  4. Effectiveness of X-ray grating interferometry for non-destructive inspection of packaged devices

    Science.gov (United States)

    Uehara, Masato; Yashiro, Wataru; Momose, Atsushi

    2013-10-01

    It is difficult to inspect packaged devices such as IC packages and power modules because the devices contain various components, such as semiconductors, metals, ceramics, and resin. In this paper, we demonstrated the effectiveness of X-ray grating interferometry (XGI) using a laboratory X-ray tube for the industrial inspection of packaged devices. The obtained conventional absorption image showed heavy-elemental components such as metal wires and electrodes, but the image did not reveal the defects in the light-elemental components. On the other hand, the differential phase-contrast image obtained by XGI revealed microvoids and scars in the encapsulant of the samples. The visibility contrast image also obtained by XGI showed some cracks in the ceramic insulator of power module sample. In addition, the image showed the silicon plate surrounded by the encapsulant having the same X-ray absorption coefficient. While these defects and components are invisible in the conventional industrial X-ray imaging, XGI thus has an attractive potential for the industrial inspection of the packaged devices.

  5. Thermal annealing response following irradiation of a CMOS imager for the JUICE JANUS instrument

    Science.gov (United States)

    Lofthouse-Smith, D.-D.; Soman, M. R.; Allanwood, E. A. H.; Stefanov, K. D.; Holland, A. D.; Leese, M.; Turne, P.

    2018-03-01

    ESA's JUICE (JUpiter ICy moon Explorer) spacecraft is an L-class mission destined for the Jovian system in 2030. Its primary goals are to investigate the conditions for planetary formation and the emergence of life, and how does the solar system work. The JANUS camera, an instrument on JUICE, uses a 4T back illuminated CMOS image sensor, the CIS115 designed by Teledyne e2v. JANUS imager test campaigns are studying the CIS115 following exposure to gammas, protons, electrons and heavy ions, simulating the harsh radiation environment present in the Jovian system. The degradation of 4T CMOS device performance following proton fluences is being studied, as well as the effectiveness of thermal annealing to reverse radiation damage. One key parameter for the JANUS mission is the Dark current of the CIS115, which has been shown to degrade in previous radiation campaigns. A thermal anneal of the CIS115 has been used to accelerate any annealing following the irradiation as well as to study the evolution of any performance characteristics. CIS115s have been irradiated to double the expected End of Life (EOL) levels for displacement damage radiation (2×1010 protons, 10 MeV equivalent). Following this, devices have undergone a thermal anneal cycle at 100oC for 168 hours to reveal the extent to which CIS115 recovers pre-irradiation performance. Dark current activation energy analysis following proton fluence gives information on trap species present in the device and how effective anneal is at removing these trap species. Thermal anneal shows no quantifiable change in the activation energy of the dark current following irradiation.

  6. A high-speed scintillation-based electronic portal imaging device to quantitatively characterize IMRT delivery.

    Science.gov (United States)

    Ranade, Manisha K; Lynch, Bart D; Li, Jonathan G; Dempsey, James F

    2006-01-01

    We have developed an electronic portal imaging device (EPID) employing a fast scintillator and a high-speed camera. The device is designed to accurately and independently characterize the fluence delivered by a linear accelerator during intensity modulated radiation therapy (IMRT) with either step-and-shoot or dynamic multileaf collimator (MLC) delivery. Our aim is to accurately obtain the beam shape and fluence of all segments delivered during IMRT, in order to study the nature of discrepancies between the plan and the delivered doses. A commercial high-speed camera was combined with a terbium-doped gadolinium-oxy-sulfide (Gd2O2S:Tb) scintillator to form an EPID for the unaliased capture of two-dimensional fluence distributions of each beam in an IMRT delivery. The high speed EPID was synchronized to the accelerator pulse-forming network and gated to capture every possible pulse emitted from the accelerator, with an approximate frame rate of 360 frames-per-second (fps). A 62-segment beam from a head-and-neck IMRT treatment plan requiring 68 s to deliver was recorded with our high speed EPID producing approximately 6 Gbytes of imaging data. The EPID data were compared with the MLC instruction files and the MLC controller log files. The frames were binned to provide a frame rate of 72 fps with a signal-to-noise ratio that was sufficient to resolve leaf positions and segment fluence. The fractional fluence from the log files and EPID data agreed well. An ambiguity in the motion of the MLC during beam on was resolved. The log files reported leaf motions at the end of 33 of the 42 segments, while the EPID observed leaf motions in only 7 of the 42 segments. The static IMRT segment shapes observed by the high speed EPID were in good agreement with the shapes reported in the log files. The leaf motions observed during beam-on for step-and-shoot delivery were not temporally resolved by the log files.

  7. A high-speed scintillation-based electronic portal imaging device to quantitatively characterize IMRT delivery

    International Nuclear Information System (INIS)

    Ranade, Manisha K.; Lynch, Bart D.; Li, Jonathan G.; Dempsey, James F.

    2006-01-01

    We have developed an electronic portal imaging device (EPID) employing a fast scintillator and a high-speed camera. The device is designed to accurately and independently characterize the fluence delivered by a linear accelerator during intensity modulated radiation therapy (IMRT) with either step-and-shoot or dynamic multileaf collimator (MLC) delivery. Our aim is to accurately obtain the beam shape and fluence of all segments delivered during IMRT, in order to study the nature of discrepancies between the plan and the delivered doses. A commercial high-speed camera was combined with a terbium-doped gadolinium-oxy-sulfide (Gd 2 O 2 S:Tb) scintillator to form an EPID for the unaliased capture of two-dimensional fluence distributions of each beam in an IMRT delivery. The high speed EPID was synchronized to the accelerator pulse-forming network and gated to capture every possible pulse emitted from the accelerator, with an approximate frame rate of 360 frames-per-second (fps). A 62-segment beam from a head-and-neck IMRT treatment plan requiring 68 s to deliver was recorded with our high speed EPID producing approximately 6 Gbytes of imaging data. The EPID data were compared with the MLC instruction files and the MLC controller log files. The frames were binned to provide a frame rate of 72 fps with a signal-to-noise ratio that was sufficient to resolve leaf positions and segment fluence. The fractional fluence from the log files and EPID data agreed well. An ambiguity in the motion of the MLC during beam on was resolved. The log files reported leaf motions at the end of 33 of the 42 segments, while the EPID observed leaf motions in only 7 of the 42 segments. The static IMRT segment shapes observed by the high speed EPID were in good agreement with the shapes reported in the log files. The leaf motions observed during beam-on for step-and-shoot delivery were not temporally resolved by the log files

  8. Dosimetric verification of radiation therapy including intensity modulated treatments, using an amorphous-silicon electronic portal imaging device

    Science.gov (United States)

    Chytyk-Praznik, Krista Joy

    Radiation therapy is continuously increasing in complexity due to technological innovation in delivery techniques, necessitating thorough dosimetric verification. Comparing accurately predicted portal dose images to measured images obtained during patient treatment can determine if a particular treatment was delivered correctly. The goal of this thesis was to create a method to predict portal dose images that was versatile and accurate enough to use in a clinical setting. All measured images in this work were obtained with an amorphous silicon electronic portal imaging device (a-Si EPID), but the technique is applicable to any planar imager. A detailed, physics-motivated fluence model was developed to characterize fluence exiting the linear accelerator head. The model was further refined using results from Monte Carlo simulations and schematics of the linear accelerator. The fluence incident on the EPID was converted to a portal dose image through a superposition of Monte Carlo-generated, monoenergetic dose kernels specific to the a-Si EPID. Predictions of clinical IMRT fields with no patient present agreed with measured portal dose images within 3% and 3 mm. The dose kernels were applied ignoring the geometrically divergent nature of incident fluence on the EPID. A computational investigation into this parallel dose kernel assumption determined its validity under clinically relevant situations. Introducing a patient or phantom into the beam required the portal image prediction algorithm to account for patient scatter and attenuation. Primary fluence was calculated by attenuating raylines cast through the patient CT dataset, while scatter fluence was determined through the superposition of pre-calculated scatter fluence kernels. Total dose in the EPID was calculated by convolving the total predicted incident fluence with the EPID-specific dose kernels. The algorithm was tested on water slabs with square fields, agreeing with measurement within 3% and 3 mm. The

  9. Optically sensitive devices based on Pt nano particles fabricated by atomic layer deposition and embedded in a dielectric stack

    Energy Technology Data Exchange (ETDEWEB)

    Mikhelashvili, V.; Padmanabhan, R.; Eisenstein, G. [Electrical Engineering Department, Technion, Haifa 3200 (Israel); Russell Berrie Nanotechnology Institute, Technion, Haifa 3200 (Israel); Meyler, B.; Yofis, S.; Weindling, S.; Salzman, J. [Electrical Engineering Department, Technion, Haifa 3200 (Israel); Atiya, G.; Cohen-Hyams, Z.; Kaplan, W. D. [Department of Material Science and Engineering, Technion, Haifa 3200 (Israel); Russell Berrie Nanotechnology Institute, Technion, Haifa 3200 (Israel); Ankonina, G. [Russell Berrie Nanotechnology Institute, Technion, Haifa 3200 (Israel); Photovoltaic Laboratory, Technion, Haifa 3200 (Israel)

    2015-10-07

    We report a series of metal insulator semiconductor devices with embedded Pt nano particles (NPs) fabricated using a low temperature atomic layer deposition process. Optically sensitive nonvolatile memory cells as well as optical sensors: (i) varactors, whose capacitance-voltage characteristics, nonlinearity, and peak capacitance are strongly dependent on illumination intensity; (ii) highly linear photo detectors whose responsivity is enhanced due to the Pt NPs. Both single devices and back to back pairs of diodes were used. The different configurations enable a variety of functionalities with many potential applications in biomedical sensing, environmental surveying, simple imagers for consumer electronics and military uses. The simplicity and planar configuration of the proposed devices makes them suitable for standard CMOS fabrication technology.

  10. Optically sensitive devices based on Pt nano particles fabricated by atomic layer deposition and embedded in a dielectric stack

    International Nuclear Information System (INIS)

    Mikhelashvili, V.; Padmanabhan, R.; Eisenstein, G.; Meyler, B.; Yofis, S.; Weindling, S.; Salzman, J.; Atiya, G.; Cohen-Hyams, Z.; Kaplan, W. D.; Ankonina, G.

    2015-01-01

    We report a series of metal insulator semiconductor devices with embedded Pt nano particles (NPs) fabricated using a low temperature atomic layer deposition process. Optically sensitive nonvolatile memory cells as well as optical sensors: (i) varactors, whose capacitance-voltage characteristics, nonlinearity, and peak capacitance are strongly dependent on illumination intensity; (ii) highly linear photo detectors whose responsivity is enhanced due to the Pt NPs. Both single devices and back to back pairs of diodes were used. The different configurations enable a variety of functionalities with many potential applications in biomedical sensing, environmental surveying, simple imagers for consumer electronics and military uses. The simplicity and planar configuration of the proposed devices makes them suitable for standard CMOS fabrication technology

  11. Experimental device, corresponding forward model and processing of the experimental data using wavelet analysis for tomographic image reconstruction applied to eddy current nondestructive evaluation

    International Nuclear Information System (INIS)

    Joubert, P.Y.; Madaoui, N.

    1999-01-01

    In the context of eddy current non destructive evaluation using a tomographic image reconstruction process, the success of the reconstruction depends not only on the choice of the forward model and of the inversion algorithms, but also on the ability to extract the pertinent data from the raw signal provided by the sensor. We present in this paper, an experimental device designed for imaging purposes, the corresponding forward model, and a pre-processing of the experimental data using wavelet analysis. These three steps implemented with an inversion algorithm, will allow in the future to perform image reconstruction of 3-D flaws. (authors)

  12. A multicolor imaging pyrometer

    Science.gov (United States)

    Frish, Michael B.; Frank, Jonathan H.

    1989-06-01

    A multicolor imaging pyrometer was designed for accurately and precisely measuring the temperature distribution histories of small moving samples. The device projects six different color images of the sample onto a single charge coupled device array that provides an RS-170 video signal to a computerized frame grabber. The computer automatically selects which one of the six images provides useful data, and converts that information to a temperature map. By measuring the temperature of molten aluminum heated in a kiln, a breadboard version of the device was shown to provide high accuracy in difficult measurement situations. It is expected that this pyrometer will ultimately find application in measuring the temperature of materials undergoing radiant heating in a microgravity acoustic levitation furnace.

  13. New device based on the super spatial resolution (SSR) method

    International Nuclear Information System (INIS)

    Soluri, A.; Atzeni, G.; Ucci, A.; Bellone, T.; Cusanno, F.; Rodilossi, G.; Massari, R.

    2013-01-01

    Recently it have been described that innovative methods, namely Super Spatial Resolution (SSR), can be used to improve the scintigraphic imaging. The aim of SSR techniques is the enhancement of the resolution of an imaging system, using information from several images. In this paper we describe a new experimental apparatus that could be used for molecular imaging and small animal imaging. In fact we present a new device, completely automated, that uses the SSR method and provides images with better spatial resolution in comparison to the original resolution. Preliminary small animal imaging studies confirm the feasibility of a very high resolution system in scintigraphic imaging and the possibility to have gamma cameras using the SSR method, to perform the applications on functional imaging. -- Highlights: • Super spatial resolution brings a high resolution image from scintigraphic images. • Resolution improvement depends on the signal to noise ratio of the original images. • The SSR shows significant improvement on spatial resolution in scintigraphic images. • The SSR method is potentially utilizable for all scintigraphic devices

  14. In vivo retinal imaging for fixational eye motion detection using a high-speed digital micromirror device (DMD)-based ophthalmoscope.

    Science.gov (United States)

    Vienola, Kari V; Damodaran, Mathi; Braaf, Boy; Vermeer, Koenraad A; de Boer, Johannes F

    2018-02-01

    Retinal motion detection with an accuracy of 0.77 arcmin corresponding to 3.7 µm on the retina is demonstrated with a novel digital micromirror device based ophthalmoscope. By generating a confocal image as a reference, eye motion could be measured from consecutively measured subsampled frames. The subsampled frames provide 7.7 millisecond snapshots of the retina without motion artifacts between the image points of the subsampled frame, distributed over the full field of view. An ophthalmoscope pattern projection speed of 130 Hz enabled a motion detection bandwidth of 65 Hz. A model eye with a scanning mirror was built to test the performance of the motion detection algorithm. Furthermore, an in vivo motion trace was obtained from a healthy volunteer. The obtained eye motion trace clearly shows the three main types of fixational eye movements. Lastly, the obtained eye motion trace was used to correct for the eye motion in consecutively obtained subsampled frames to produce an averaged confocal image correct for motion artefacts.

  15. Architecture, development and implementation of a SWIR to visible integrated up-conversion imaging device

    Science.gov (United States)

    Sarusi, Gabby; Templeman, Tzvi; Hechster, Elad; Nissim, Nimrod; Vitenberg, Vladimir; Maman, Nitzan; Tal, Amir; Solodar, Assi; Makov, Guy; Abdulhalim, Ibrahim; Visoly-Fisher, Iris; Golan, Yuval

    2016-04-01

    A new concept of short wavelength infrared (SWIR) to visible upconversion integrated imaging device is proposed, modeled and some initial measured results are presented. The device is a hybrid inorganic-organic device that comprises six nano-metric scale sub-layers grown on n-type GaAs substrates. The first layer is a ~300nm thick PbSe nano-columnar absorber layer grown in (111) orientation to the substrate plan (100), with a diameter of 8- 10nm and therefore exhibit quantum confinement effects parallel to the substrate and bulk properties perpendicular to it. The advantage of this structure is the high oscillator strength and hence absorption to incoming SWIR photons while maintaining the high bulk mobility of photo-excited charges along the columns. The top of the PbSe absorber layer is coated with 20nm thick metal layer that serves as a dual sided mirror, as well as a potentially surface plasmon enhanced absorption in the PbSe nano-columns layer. The photo-excited charges (holes and electrons in opposite directions) are drifted under an external applied field to the OLED section (that is composed of a hole transport layer, an emission layer and an electron transport layer) where they recombine with injected electron from the transparent cathode and emit visible light through this cathode. Due to the high absorption and enhanced transport properties this architecture has the potential of high quantum efficiency, low cost and easy implementation in any optical system. As a bench-mark, alternative concept where InGaAs/InP heterojunction couple to liquid crystal optical spatial light modulator (OSLM) structure was built that shows a full upconversion to visible of 1550nm laser light.

  16. Information retrieval based on single-pixel optical imaging with quick-response code

    Science.gov (United States)

    Xiao, Yin; Chen, Wen

    2018-04-01

    Quick-response (QR) code technique is combined with ghost imaging (GI) to recover original information with high quality. An image is first transformed into a QR code. Then the QR code is treated as an input image in the input plane of a ghost imaging setup. After measurements, traditional correlation algorithm of ghost imaging is utilized to reconstruct an image (QR code form) with low quality. With this low-quality image as an initial guess, a Gerchberg-Saxton-like algorithm is used to improve its contrast, which is actually a post processing. Taking advantage of high error correction capability of QR code, original information can be recovered with high quality. Compared to the previous method, our method can obtain a high-quality image with comparatively fewer measurements, which means that the time-consuming postprocessing procedure can be avoided to some extent. In addition, for conventional ghost imaging, the larger the image size is, the more measurements are needed. However, for our method, images with different sizes can be converted into QR code with the same small size by using a QR generator. Hence, for the larger-size images, the time required to recover original information with high quality will be dramatically reduced. Our method makes it easy to recover a color image in a ghost imaging setup, because it is not necessary to divide the color image into three channels and respectively recover them.

  17. Modern devices the simple physics of sophisticated technology

    CERN Document Server

    Joseph, Charles L

    2016-01-01

    This book discusses the principles of physics through applications of state-of-the-art technologies and advanced instruments. The authors use diagrams, sketches, and graphs coupled with equations and mathematical analysis to enhance the reader's understanding of modern devices. Readers will learn to identify common underlying physical principles that govern several types of devices, while gaining an understanding of the performance trade-off imposed by the physical limitations of various processing methods. The topics discussed in the book assume readers have taken an introductory physics course, college algebra, and have a basic understanding of calculus. * Describes the basic physics behind a large number of devices encountered in everyday life, from the air conditioner to Blu-ray discs * Covers state-of-the-art devices such as spectrographs, photoelectric image sensors, spacecraft systems, astronomical and planetary observatories, biomedical imaging instruments, particle accelerators, and jet engines * Inc...

  18. Corporate social responsibility in shaping the media image of the company

    Directory of Open Access Journals (Sweden)

    Magdalena Andrejczuk

    2010-06-01

    Full Text Available Enterprises frequently employ Corporate Social Responsibility (CSR to create a positive brand image in the media. To further good relations with stakeholders, companies create an image before their customers by their participation in public campaigns and information in advertisements employing elements of CSR. Discussing this practice, I will highlight aspects of this phenomenon in the context of consumer opinion about advertisements. Some examples of companies show that Cause Related Marketing (CRM and public campaigns are becoming more significant in the strategies of cause related companies. Enterprises at all costs want to buy their way into the favour of stakeholders, and through various marketing actions they try to build a strong brand and position in this way. In spite of the low evaluation of advertisements and the decline in confidence in them, enterprises aim to convince everyone that they are socially responsible companies.

  19. Application of stereo-imaging technology to medical field.

    Science.gov (United States)

    Nam, Kyoung Won; Park, Jeongyun; Kim, In Young; Kim, Kwang Gi

    2012-09-01

    There has been continuous development in the area of stereoscopic medical imaging devices, and many stereoscopic imaging devices have been realized and applied in the medical field. In this article, we review past and current trends pertaining to the application stereo-imaging technologies in the medical field. We describe the basic principles of stereo vision and visual issues related to it, including visual discomfort, binocular disparities, vergence-accommodation mismatch, and visual fatigue. We also present a brief history of medical applications of stereo-imaging techniques, examples of recently developed stereoscopic medical devices, and patent application trends as they pertain to stereo-imaging medical devices. Three-dimensional (3D) stereo-imaging technology can provide more realistic depth perception to the viewer than conventional two-dimensional imaging technology. Therefore, it allows for a more accurate understanding and analysis of the morphology of an object. Based on these advantages, the significance of stereoscopic imaging in the medical field increases in accordance with the increase in the number of laparoscopic surgeries, and stereo-imaging technology plays a key role in the diagnoses of the detailed morphologies of small biological specimens. The application of 3D stereo-imaging technology to the medical field will help improve surgical accuracy, reduce operation times, and enhance patient safety. Therefore, it is important to develop more enhanced stereoscopic medical devices.

  20. Magnetic Field Interactions of Copper-Containing Intrauterine Devices in 3.0-Tesla Magnetic Resonance Imaging: In Vivo Study

    Energy Technology Data Exchange (ETDEWEB)

    Berger-Kulemann, Vanessa; Einspieler, Henrik [Department of Radiology, Medical University of Vienna, Vienna 1090 (Austria); Hachemian, Nilouparak [Department of Obstetrics and Gynecology, Medical University of Vienna, Vienna 1090 (Austria); Prayer, Daniela; Trattnig, Siegfried; Weber, Michael; Ba-Ssalamah, Ahmed [Department of Radiology, Medical University of Vienna, Vienna 1090 (Austria)

    2013-07-01

    An ex vivo study found a copper-containing intrauterine device (IUD) to be safe for women undergoing an MRI examination at a 3.0-T field. No significant artifacts caused by the metallic implant were detected. However, there are still no in vivo data about these concerns. The aim of this study was to evaluate 3.0-T magnetic field interactions of copper-containing IUDs in vivo. Magnetic field interactions and potential adverse events were evaluated in 33 women using a questionnaire-based telephone survey. Two experienced radiologists performed artifact evaluation on MR images of the pelvis. Eighteen patients were eligible for the survey. One patient reported a dislocation of the IUD after the MR examination. All other patients had no signs of field interactions. No IUD-related artifacts were found. MRI at 3.0-T is possible for women with copper-containing IUDs. However, consulting a gynecologist to check the correct position of the IUD and exclude complications after an MR examination is highly recommended. High-quality clinical imaging of the female pelvis can be performed without a loss in image quality.