WorldWideScience

Sample records for testing visual prostheses

  1. Cortical visual prostheses: from microstimulation to functional percept

    Science.gov (United States)

    Najarpour Foroushani, Armin; Pack, Christopher C.; Sawan, Mohamad

    2018-04-01

    Cortical visual prostheses are intended to restore vision by targeted electrical stimulation of the visual cortex. The perception of spots of light, called phosphenes, resulting from microstimulation of the visual pathway, suggests the possibility of creating meaningful percept made of phosphenes. However, to date electrical stimulation of V1 has still not resulted in perception of phosphenated images that goes beyond punctate spots of light. In this review, we summarize the clinical and experimental progress that has been made in generating phosphenes and modulating their associated perceptual characteristics in human and macaque primary visual cortex (V1). We focus specifically on the effects of different microstimulation parameters on perception and we analyse key challenges facing the generation of meaningful artificial percepts. Finally, we propose solutions to these challenges based on the application of supervised learning of population codes for spatial stimulation of visual cortex.

  2. Visual prostheses: The enabling technology to give sight to the blind

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Maghami

    2014-01-01

    Full Text Available Millions of patients are either slowly losing their vision or are already blind due to retinal degenerative diseases such as retinitis pigmentosa (RP and age-related macular degeneration (AMD or because of accidents or injuries. Employment of artificial means to treat extreme vision impairment has come closer to reality during the past few decades. Currently, many research groups work towards effective solutions to restore a rudimentary sense of vision to the blind. Aside from the efforts being put on replacing damaged parts of the retina by engineered living tissues or microfabricated photoreceptor arrays, implantable electronic microsystems, referred to as visual prostheses, are also sought as promising solutions to restore vision. From a functional point of view, visual prostheses receive image information from the outside world and deliver them to the natural visual system, enabling the subject to receive a meaningful perception of the image. This paper provides an overview of technical design aspects and clinical test results of visual prostheses, highlights past and recent progress in realizing chronic high-resolution visual implants as well as some technical challenges confronted when trying to enhance the functional quality of such devices.

  3. Simulating auditory and visual sensorineural prostheses: a comparative review

    Science.gov (United States)

    Hallum, L. E.; Dagnelie, G.; Suaning, G. J.; Lovell, N. H.

    2007-03-01

    Microelectronic vision prosthesis proposes to render luminous spots (so-called phosphenes) in the visual field of the otherwise blind subject by way of an implanted array of stimulating electrodes, and in doing so restore some spatial vision. There are now many research teams worldwide working towards a therapeutic device, analogous to the cochlear implant, for the profoundly blind. Despite the similarities between the cochlear implant and vision prostheses, there are few instances in the literature where the two approaches are compared and contrasted with a mind to informing the science and engineering of the latter. This is the focus of the present review; specifically, our interest is psychophysics and signal processing. Firstly, we examine the cochlear implant, and review a handful of psychophysical work: the acoustic simulation of cochlear implants and the method used. We focus on the use of normally hearing subjects (played coloured noise bands or sine waves) as a means of investigating cochlear-implant efficacy and speech processing algorithms. These results provide guidance to vision researchers, for they address the interpretation of simulation data, and flag key areas, such as 'artificial' perception in the presence of noise, that require experimental work in coming years. Secondly, we provide an up-to-date review of the body of analogous psychophysical work: the visual simulation, involving normal observers, of microelectronic vision prosthesis. These simulations allow predictions as to the likely clinical efficacy of the prosthesis; indeed, results to date suggest that a number on the order of 100 implanted electrodes will afford subjects mobility and recognition of faces (and other complex stimuli), while even fewer electrodes facilitate reading printed text and very simple visuomanual tasks. Further, the simulations allow investigations of image and signal processing strategies, plus they provide researchers in the field, and other interested persons

  4. Development of friction and wear full-scale testing for TKR prostheses with reliable low cost apparatus

    Science.gov (United States)

    Suwandi, Agri; Soemardi, Tresna P.; Kiswanto, Gandjar; Kusumaningsih, Widjajalaksmi; I. Gusti Agung I. G., W.

    2018-02-01

    Prostheses products must undergo simulation and physical testing, before clinical testing. Finite element method is a preliminary simulation for in vivo test. The method visualizes the magnitude of the compressive force and the critical location of the Total Knee Replacement (TKR) prostheses design. In vitro testing is classified as physical testing for prostheses product. The test is conducted to evaluate the potential failure of the product and the characteristics of the prostheses TKR material. Friction and wear testing are part of the in vivo test. Motion of knee joints, which results in the phenomena of extension and deflection in the femoral and tibia insert, is represented by friction and wear testing. Friction and wear tests aim to obtain an approximate lifetime in normal and extreme load patterns as characterized by the shape of the friction surface area. The lifetime estimation requires friction and wear full-scale testing equipments for TKR prostheses products. These are necessary in obtaining initial data on potential product failures and characterizing of the material based on the ASTM F2724-08 standards. Based on the testing result and statistical analysis data, the average wear rate value per year is 2.19 × 10-3 mg/MC, with a 10 % safety limit of volume and 14,400 cycles times, for 15 hours moving nonstop then the prediction of wear life of the component tibia insert is ± 10 years.

  5. PERSPECTIVE: Is acuity enough? Other considerations in clinical investigations of visual prostheses

    Science.gov (United States)

    Lepri, Bernard P.

    2009-06-01

    Visual impairing eye diseases are the major frontier facing ophthalmic research today in light of our rapidly aging population. The visual skills necessary for improving the quality of daily function and life are inextricably linked to these impairing diseases. Both research and reimbursement programs are emphasizing outcome-based results. Is improvement in visual acuity alone enough to improve the function and quality of life of visually impaired persons? This perspective summarizes the types of effectiveness endpoints for clinical investigations of visual prostheses that go beyond visual acuity. The clinical investigation of visual prostheses should include visual function, functional vision and quality of life measures. Specifically, they encompass contrast sensitivity, orientation and mobility, activities of daily living and quality of life assessments. The perspective focuses on the design of clinical trials for visual prostheses and the methods of determining effectiveness above and beyond visual acuity that will yield outcomes that are measured by improved function in the visual world and quality of life. The visually impaired population is the primary consideration in this presentation with particular emphases on retinitis pigmentosa and age-related macular degeneration. Clinical trials for visual prostheses cannot be isolated from the need for medical rehabilitation in order to obtain measurements of effectiveness that produce outcomes/evidence-based success. This approach will facilitate improvement in daily function and quality of life of patients with diseases that cause chronic vision impairment. The views and opinions are those of the author and do not necessarily reflect those of the US Food and Drug Administration, the US Department of Health and Human Services or the Public Health Service.

  6. [Image processing system of visual prostheses based on digital signal processor DM642].

    Science.gov (United States)

    Xie, Chengcheng; Lu, Yanyu; Gu, Yun; Wang, Jing; Chai, Xinyu

    2011-09-01

    This paper employed a DSP platform to create the real-time and portable image processing system, and introduced a series of commonly used algorithms for visual prostheses. The results of performance evaluation revealed that this platform could afford image processing algorithms to be executed in real time.

  7. Microcomputer-based artificial vision support system for real-time image processing for camera-driven visual prostheses

    Science.gov (United States)

    Fink, Wolfgang; You, Cindy X.; Tarbell, Mark A.

    2010-01-01

    It is difficult to predict exactly what blind subjects with camera-driven visual prostheses (e.g., retinal implants) can perceive. Thus, it is prudent to offer them a wide variety of image processing filters and the capability to engage these filters repeatedly in any user-defined order to enhance their visual perception. To attain true portability, we employ a commercial off-the-shelf battery-powered general purpose Linux microprocessor platform to create the microcomputer-based artificial vision support system (μAVS2) for real-time image processing. Truly standalone, μAVS2 is smaller than a deck of playing cards, lightweight, fast, and equipped with USB, RS-232 and Ethernet interfaces. Image processing filters on μAVS2 operate in a user-defined linear sequential-loop fashion, resulting in vastly reduced memory and CPU requirements during execution. μAVS2 imports raw video frames from a USB or IP camera, performs image processing, and issues the processed data over an outbound Internet TCP/IP or RS-232 connection to the visual prosthesis system. Hence, μAVS2 affords users of current and future visual prostheses independent mobility and the capability to customize the visual perception generated. Additionally, μAVS2 can easily be reconfigured for other prosthetic systems. Testing of μAVS2 with actual retinal implant carriers is envisioned in the near future.

  8. Polyurethane unicondylar knee prostheses: simulator wear tests and lubrication studies

    Energy Technology Data Exchange (ETDEWEB)

    Scholes, S C [Centre for Biomedical Engineering, Durham University, DH1 3LE (United Kingdom); Unsworth, A [Centre for Biomedical Engineering, Durham University, DH1 3LE (United Kingdom); Jones, E [Stryker Orthopaedics, Limerick (United Kingdom)

    2007-01-07

    Many materials are used as artificial joint bearing surfaces; these include conventional stainless steel or CoCrMo-on-ultra-high molecular weight polyethylene (UHMWPE), CoCrMo on itself and alumina-on-alumina. However, these joints have a limited lifespan resulting in failure of the prosthesis and the need for revision surgery. A number of materials have been introduced recently in an attempt to overcome these problems. Polycarbonate urethane (PU) is a compliant material that can be used as an artificial joint bearing surface which has been developed to mimic the natural synovial joint more accurately by promoting fluid film lubrication. Tribological tests were performed on CoCrMo-on-PU unicondylar knee prostheses to assess their performance in vitro. The wear produced by these components was considerably lower than that found for conventional joints. They also exhibited low friction and operated close to full-fluid film lubrication with viscosities of lubricant similar to those found in patients with arthritis. These tests gave encouraging results for the tribological performance of this material couple for use as an alternative bearing combination.

  9. Visual acuity test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003396.htm Visual acuity test To use the sharing features on this page, please enable JavaScript. The visual acuity test is used to determine the smallest ...

  10. Visual Acuity of Simulated Thalamic Visual Prostheses in Normally Sighted Humans

    Science.gov (United States)

    Jeffries, Ailsa; Pezaris, John S.

    2013-01-01

    Simulation in normally sighted individuals is a crucial tool to evaluate the performance of potential visual prosthesis designs prior to human implantation of a device. Here, we investigated the effects of electrode count on visual acuity, learning rate and response time in 16 normally sighted subjects using a simulated thalamic visual prosthesis, providing the first performance reports for thalamic designs. A new letter recognition paradigm using a multiple-optotype two-alternative forced choice task was adapted from the Snellen eye chart, and specifically devised to be readily communicated to both human and non-human primate subjects. Validation of the method against a standard Snellen acuity test in 21 human subjects showed no significant differences between the two tests. The novel task was then used to address three questions about simulations of the center-weighted phosphene patterns typical of thalamic designs: What are the expected Snellen acuities for devices with varying numbers of contacts, do subjects display rapid adaptation to the new visual modality, and can response time in the task provide clues to the mechanisms of perception in low-resolution artificial vision? Population performance (hit rate) was significantly above chance when viewing Snellen 20/200 optotypes (Log MAR 1.0) with 370 phosphenes in the central 10 degrees of vision, ranging to Snellen 20/800 (Log MAR 1.6) with 25 central phosphenes. Furthermore, subjects demonstrated learning within the 1–2 hours of task experience indicating the potential for an effective rehabilitation and possibly better visual performance after a longer period of training. Response time differences suggest that direct letter perception occurred when hit rate was above 75%, whereas a slower strategy like feature-based pattern matching was used in conditions of lower relative resolution. As pattern matching can substantially boost effective acuity, these results suggest post-implant therapy should specifically

  11. Visual acuity of simulated thalamic visual prostheses in normally sighted humans.

    Directory of Open Access Journals (Sweden)

    Béchir Bourkiza

    Full Text Available Simulation in normally sighted individuals is a crucial tool to evaluate the performance of potential visual prosthesis designs prior to human implantation of a device. Here, we investigated the effects of electrode count on visual acuity, learning rate and response time in 16 normally sighted subjects using a simulated thalamic visual prosthesis, providing the first performance reports for thalamic designs. A new letter recognition paradigm using a multiple-optotype two-alternative forced choice task was adapted from the Snellen eye chart, and specifically devised to be readily communicated to both human and non-human primate subjects. Validation of the method against a standard Snellen acuity test in 21 human subjects showed no significant differences between the two tests. The novel task was then used to address three questions about simulations of the center-weighted phosphene patterns typical of thalamic designs: What are the expected Snellen acuities for devices with varying numbers of contacts, do subjects display rapid adaptation to the new visual modality, and can response time in the task provide clues to the mechanisms of perception in low-resolution artificial vision? Population performance (hit rate was significantly above chance when viewing Snellen 20/200 optotypes (Log MAR 1.0 with 370 phosphenes in the central 10 degrees of vision, ranging to Snellen 20/800 (Log MAR 1.6 with 25 central phosphenes. Furthermore, subjects demonstrated learning within the 1-2 hours of task experience indicating the potential for an effective rehabilitation and possibly better visual performance after a longer period of training. Response time differences suggest that direct letter perception occurred when hit rate was above 75%, whereas a slower strategy like feature-based pattern matching was used in conditions of lower relative resolution. As pattern matching can substantially boost effective acuity, these results suggest post-implant therapy

  12. Model-based analysis of multiple electrode array stimulation for epiretinal visual prostheses

    Science.gov (United States)

    Mueller, Jerel K.; Grill, Warren M.

    2013-06-01

    Objective. Epiretinal stimulation, which uses an array of electrodes implanted on the inner retinal surface to relay a representation of the visual scene to the neuronal elements of the retina, has seen considerable success. The objective of the present study was to quantify the effects of multi-electrode stimulation on the patterns of neural excitation in a computational model of epiretinal stimulation. Approach. A computational model of retinal ganglion cells was modified to represent the morphology of human retinal ganglion cells and validated against published experimental data. The ganglion cell model was then combined with a model of an axon of the nerve fiber layer to produce a population model of the inner retina. The response of the population of model neurons to epiretinal stimulation with a multi-electrode array was quantified across a range of electrode geometries using a novel means to quantify the model response—the minimum radius circle bounding the activated model neurons as a proxy for the evoked phosphene. Main results. Multi-electrode stimulation created unique phosphenes, such that the number of potential phosphenes can far exceed the number of electrode contacts. Significance. The ability to exploit the spatial and temporal interactions of stimulation may be critical to improvements in the performance of epiretinal prostheses.

  13. Evaluation of taper joints with combined fatigue and crevice corrosion testing: Comparison to human explanted modular prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Reclaru, L., E-mail: lucien.reclaru@pxgroup.com [PX Group S.A., Dep R and D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds (Switzerland); Brooks, R.A. [Orthopaedic Research, Addenbrooke' s Hospital, University of Cambridge, Box 180 Hills Road, CB2 0QQ Cambridge (United Kingdom); Zuberbühler, M. [Smith and Nephew Orthopaedics AG, Schachenalle 29, 5001 Aarau (Switzerland); Eschler, P.-Y.; Constantin, F. [PX Group S.A., Dep R and D Corrosion and Biocompatibility Group, Bd. des Eplatures 42, CH-2304 La Chaux-de-Fonds (Switzerland); Tomoaia, G. [University of Medicine and Pharmacy Iuliu Hateganu of Cluj-Napoca, Dept. of Orthopaedics and Traumatology, Cluj-Napoca (Romania)

    2014-01-01

    The requirement for revision surgery of total joint replacements is increasing and modular joint replacement implants have been developed to provide adjustable prosthetic revision systems with improved intra-operative flexibility. An electrochemical study of the corrosion resistance of the interface between the distal and proximal modules of a modular prosthesis was performed in combination with a cyclic fatigue test. The complexity resides in the existence of interfaces between the distal part, the proximal part, and the dynamometric screw. A new technique for evaluating the resistance to cyclic dynamic corrosion with crevice stimulation was used and the method is presented. In addition, two components of the proximal module of explanted Ti6Al4V and Ti6Al7Nb prostheses were investigated by optical and electron microscopy. Our results reveal that: The electrolyte penetrates into the interface between the distal and proximal modules during cyclic dynamic fatigue tests, the distal module undergoes cracking and corrosion was generated at the interface between the two models; The comparison of the explanted proximal parts with the similar prostheses evaluated following cyclic dynamic crevice corrosion testing showed that there were significant similarities indicating that this method is suitable for evaluating materials used in the fabrication of modular prostheses. - Highlights: • Electrochemical crevice corrosion testing combined with fatigue test conducted on Ti6Al7Nb and Ti6Al4V modular prostheses • Cations released from integral prostheses • Comparison of human explanted modular prostheses with the similar prostheses evaluated in cyclic dynamic crevice corrosion.

  14. Evaluation of taper joints with combined fatigue and crevice corrosion testing: Comparison to human explanted modular prostheses

    International Nuclear Information System (INIS)

    Reclaru, L.; Brooks, R.A.; Zuberbühler, M.; Eschler, P.-Y.; Constantin, F.; Tomoaia, G.

    2014-01-01

    The requirement for revision surgery of total joint replacements is increasing and modular joint replacement implants have been developed to provide adjustable prosthetic revision systems with improved intra-operative flexibility. An electrochemical study of the corrosion resistance of the interface between the distal and proximal modules of a modular prosthesis was performed in combination with a cyclic fatigue test. The complexity resides in the existence of interfaces between the distal part, the proximal part, and the dynamometric screw. A new technique for evaluating the resistance to cyclic dynamic corrosion with crevice stimulation was used and the method is presented. In addition, two components of the proximal module of explanted Ti6Al4V and Ti6Al7Nb prostheses were investigated by optical and electron microscopy. Our results reveal that: The electrolyte penetrates into the interface between the distal and proximal modules during cyclic dynamic fatigue tests, the distal module undergoes cracking and corrosion was generated at the interface between the two models; The comparison of the explanted proximal parts with the similar prostheses evaluated following cyclic dynamic crevice corrosion testing showed that there were significant similarities indicating that this method is suitable for evaluating materials used in the fabrication of modular prostheses. - Highlights: • Electrochemical crevice corrosion testing combined with fatigue test conducted on Ti6Al7Nb and Ti6Al4V modular prostheses • Cations released from integral prostheses • Comparison of human explanted modular prostheses with the similar prostheses evaluated in cyclic dynamic crevice corrosion

  15. CYCLOPS: A mobile robotic platform for testing and validating image processing and autonomous navigation algorithms in support of artificial vision prostheses.

    Science.gov (United States)

    Fink, Wolfgang; Tarbell, Mark A

    2009-12-01

    While artificial vision prostheses are quickly becoming a reality, actual testing time with visual prosthesis carriers is at a premium. Moreover, it is helpful to have a more realistic functional approximation of a blind subject. Instead of a normal subject with a healthy retina looking at a low-resolution (pixelated) image on a computer monitor or head-mounted display, a more realistic approximation is achieved by employing a subject-independent mobile robotic platform that uses a pixelated view as its sole visual input for navigation purposes. We introduce CYCLOPS: an AWD, remote controllable, mobile robotic platform that serves as a testbed for real-time image processing and autonomous navigation systems for the purpose of enhancing the visual experience afforded by visual prosthesis carriers. Complete with wireless Internet connectivity and a fully articulated digital camera with wireless video link, CYCLOPS supports both interactive tele-commanding via joystick, and autonomous self-commanding. Due to its onboard computing capabilities and extended battery life, CYCLOPS can perform complex and numerically intensive calculations, such as image processing and autonomous navigation algorithms, in addition to interfacing to additional sensors. Its Internet connectivity renders CYCLOPS a worldwide accessible testbed for researchers in the field of artificial vision systems. CYCLOPS enables subject-independent evaluation and validation of image processing and autonomous navigation systems with respect to the utility and efficiency of supporting and enhancing visual prostheses, while potentially reducing to a necessary minimum the need for valuable testing time with actual visual prosthesis carriers.

  16. An Assessment of Visual Testing

    Energy Technology Data Exchange (ETDEWEB)

    Cumblidge, Stephen E.; Anderson, Michael T.; Doctor, Steven R.

    2004-11-01

    In response to increasing interest from nuclear utilities in replacing some volumetric examinations of nuclear reactor components with remote visual testing, the Pacific Northwest National Laboratory has examined the capabilities of remote visual testing for the Nuclear Regulatory Commission. This report describes visual testing and explores the visual acuities of the camera systems used to examine nuclear reactor components. The types and sizes of cracks typically found in nuclear reactor components are reviewed. The current standards in visual testing are examined critically, and several suggestions for improving these standards are proposed. Also proposed for future work is a round robin test to determine the effectiveness of visual tests and experimental studies to determine the values for magnification and resolution needed to reliably image very tight cracks.

  17. Restoration of vision in blind individuals using bionic devices: a review with a focus on cortical visual prostheses.

    Science.gov (United States)

    Lewis, Philip M; Ackland, Helen M; Lowery, Arthur J; Rosenfeld, Jeffrey V

    2015-01-21

    detail these and other challenges facing developers of cortical visual prostheses in addition to briefly outlining the epidemiology of blindness, and the history of cortical electrical stimulation in the context of visual prosthetics. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Pre-clinical evaluation of ceramic femoral head resurfacing prostheses using computational models and mechanical testing.

    Science.gov (United States)

    Dickinson, A S; Browne, M; Wilson, K C; Leffers, J R T; Taylor, A C

    2011-09-01

    Ceramic-on-ceramic hip resurfacing can potentially offer the bone-conserving advantages of resurfacing while eliminating metal ion release. Thin-walled ceramic resurfacing heads are conceivable following developments in the strength and reliability of ceramic materials, but verification of new designs is required. The present study aimed to develop a mechanical pre-clinical analysis verification process for ceramic resurfacing heads, using the DeltaSurf prosthesis design as a case study. Finite element analysis of a range of in vivo scenarios was used to design a series of physiologically representative mechanical tests, which were conducted to verify the strength of the prosthesis. Tests were designed to simulate ideal and worst-case in vivo loading and support, or to allow comparison with a clinically successful metallic device. In tests simulating ideal loading and support, the prosthesis sustained a minimum load of 39 kN before fracture, and survived 10 000 000 fatigue cycles of 0.534 kN to 5.34 kN. In worst-case tests representing a complete lack of superior femoral head bone support or pure cantilever loading of the prosthesis stem, the design demonstrated strength comparable to that of the equivalent metal device. The developed mechanical verification test programme represents an improvement in the state of the art where international test standards refer largely to total hip replacement prostheses. The case study's novel prosthesis design performed with considerable safety margins compared with extreme in vivo loads, providing evidence that the proposed ceramic resurfacing heads should have sufficient strength to perform safely in vivo. Similar verification tests should be designed and conducted for novel ceramic prosthesis designs in the future, leading the way to clinical evaluation.

  19. Visual perception skills testing: preliminary results

    CSIR Research Space (South Africa)

    Smith, Andrew C

    2009-02-01

    Full Text Available Good visual perception skills are important in the effective manipulation of Tangible User Interfaces. This paper reports on the application of a test set researchers have developed specifically to quantify the visual perception skills of children...

  20. Fabrication of a radiopaque fit-testing material to evaluate the three-dimensional accuracy of dental prostheses.

    Science.gov (United States)

    Oka, Yuzo; Sasaki, Jun-Ichi; Wakabayashi, Kazumichi; Nakano, Yoshiro; Okamura, Shin-Ya; Nakamura, Takashi; Imazato, Satoshi; Yatani, Hirofumi

    2016-07-01

    The objective of this study was to fabricate a radiopaque prosthetic fit-testing material, and to develop methodology to evaluate the fitting accuracy of prostheses three-dimensionally (3D) using a combination of the silicone replica technique and micro-computed tomography (μCT). Eight types of prototype specimens of fit-testing materials were prepared by adding contrast agents (zirconia, alumina, and barium-glass) to a commercially available fit-testing material. These specimens were evaluated on their mechanical properties, X-ray absorption coefficients, reproducibility of cement space, and suitability for 3D analysis by μCT. Then, silicone replicas made from prototype specimens were assessed for accurate 3D morphology. Subsequently, color-mapping analyses of the silicone replicas were performed according to replica thickness, and the results were compared with stereomicroscopic images. The mechanical properties, X-ray absorption coefficients, and reproducibility of the cement space demonstrated that prototypes containing 20wt% zirconia (Zr-20) or barium glass (diameter 2μm; Ba2-20) were useful as fit-testing materials. However, the morphology of the Ba2-20 silicone replica was unable to be accurately described using μCT because of its low X-ray absorption threshold. Zr-20, however, could be clearly observed on μCT imaging. Furthermore, color-mapping analysis of the μCT images demonstrated that Zr-20 was the most suitable for 3D observation of prosthetic fit. This method could allow any professional to evaluate the fit of any type of dental prosthesis, such as inlays, crowns, and fixed and removable dentures. This study demonstrated that the technique presented in the current study is able to accurately describe the abutment-crown prosthetic discrepancy based on silicone replicas. Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  1. Software testing using Visual Studio 2012

    CERN Document Server

    Subashni, S

    2013-01-01

    We will be setting up a sample test scenario, then we'll walk through the features available to deploy tests.This book is for developers and testers who want to get to grips with Visual Studio 2012 and Test Manager for all testing activities and managing tests and results in Team Foundation Server. It requires a minimal understanding of testing practices and the software development life cycle; also, some coding skills would help in customizing and updating the code generated from the web UI testing.

  2. A Pilot Study of Visual-Motor Developmental Inter-Test Reliability: The Beery Developmental Test of Visual Motor Integration and the Bender Visual Motor Gestalt Test.

    Science.gov (United States)

    Porter, Gary L.; Binder, Dorothy M.

    1981-01-01

    To determine the intertest reliability of the Beery Developmental Test of Visual Motor Integration (VMI) and the Bender Visual Motor Gestalt Test (BGT), 64 six to nine year olds were administered both tests.

  3. Computerized method of visual acuity testing: adaptation of the amblyopia treatment study visual acuity testing protocol.

    Science.gov (United States)

    Moke, P S; Turpin, A H; Beck, R W; Holmes, J M; Repka, M X; Birch, E E; Hertle, R W; Kraker, R T; Miller, J M; Johnson, C A

    2001-12-01

    To report a computerized method for determining visual acuity in children using the Amblyopia Treatment Study visual acuity testing protocol. A computerized visual acuity tester was developed that uses a programmed handheld device that uses the Palm operating system (Palm, Inc, Santa Clara, California). The handheld device communicates with a personal computer running a Linux operating system and 17-inch monitor. At a test distance of 3 m, single letters can be displayed from 20/800 to 20/12. A C program on the handheld device runs the Amblyopia Treatment Study visual acuity testing protocol. Using this method, visual acuity was tested in both the right and left eyes, and then the testing was repeated in 156 children age 3 to 7 years at four clinical sites. Test-retest reliability was high (r =.92 and 0.95 for and right and left eyes, respectively), with 88% of right eye retests and 94% of left eye retests within 0.1 logarithm of minimal angle of resolution (logMAR) units of the initial test. The 95% confidence interval for an acuity score was calculated to be the score +/- 0.13 logMAR units. For a change between two acuity scores, the 95% confidence interval was the difference +/- 0.19 logMAR units. We have developed a computerized method for measurement of visual acuity. Automation of the Amblyopia Treatment Study visual acuity testing protocol is an effective method of testing visual acuity in children 3 to 7 years of age.

  4. Adherence of Staphylococcus aureus to Dyneema Purity® Patches and to Clinically Used Cardiovascular Prostheses.

    Directory of Open Access Journals (Sweden)

    Amir Basir

    Full Text Available Various materials that are used for vascular and heart valve prostheses carry drawbacks: some require anticoagulant drugs or have moderate durability; others are not suitable for endovascular treatment. These prostheses are associated with bacterial infections. A material potentially suitable for prostheses is Dyneema Purity®, made of ultra-high-molecular-weight polyethylene. Dyneema Purity® fibers are very thin, flexible, resistant to fatigue and abrasion, and have high strength. S. aureus adherence to Dyneema Purity® was tested and compared with currently used cardiovascular prostheses. We compared adhesion of S. aureus to Dyneema Purity® (1 membrane-based and 1 yarn-composed patch with 5 clinically used yarn-composed polyester and membrane-based expanded polytetrafluoroethylene patches. Patches were contaminated with S. aureus bacteria and bacterial adherence was quantified. S. aureus adherence was also visualized in flow conditions. Overall, bacterial adherence was higher on yarn-composed prosthesis materials, with a rough surface, than on the membrane-based materials, with a smooth surface. Adherence to Dyneema Purity® materials was non-inferior to the currently used materials. Therefore, patches of Dyneema Purity® might be attractive for use in cardiovascular applications such as catheter-based heart valves and endovascular prostheses by their good mechanical properties combined with their noninferiority regarding bacterial adhesion.

  5. Assessment of Body-Powered Upper Limb Prostheses by Able-Bodied Subjects, using the Box and Blocks Test and the Nine Hole Peg Test

    NARCIS (Netherlands)

    Haverkate, L.; Smit, G.; Plettenburg, D.H.

    2014-01-01

    Study Design: Experimental trial. Background: The functional performance of currently available body-powered prostheses is unknown. Objective: The goal of this study was to objectively assess and compare the functional performance of three commonly used body-powered upper limb terminal devices.

  6. [Implant supported prostheses (1)].

    Science.gov (United States)

    del Río Highsmith, J; López Lozano, J F

    1988-11-01

    In the present article deals with a number of general considerations in the realization of prostheses over endosseous implants. The different principles to study in the construction of a fixed protesic rehabilitation implanto-supported are analyzed.

  7. Cobalt release and complications resulting from the use of dental prostheses.

    Science.gov (United States)

    Al-Imam, Hiba; Benetti, Ana R; Özhayat, Esben B; Pedersen, Anne M L; Johansen, Jeanne D; Thyssen, Jacob P; Jellesen, Morten S; Gotfredsen, Klaus

    2016-12-01

    Cobalt release from dental prostheses has been shown to elicit allergic reactions in cobalt-allergic patients. It is therefore important to investigate whether these prostheses are possible sources of sensitization. To assess (i) cobalt release from dental prostheses and (ii) allergic reactions to components of dental prostheses, and (iii) to investigate the oral mucosa for inflammation 1-5 years after insertion of the prostheses. Clinical oral examination was conducted in 66 patients with 84 dental prostheses. Cobalt release from 84 functional (used) and 32 non-functional (new) prostheses was investigated with the cobalt spot test. Contact allergy was assessed by patch testing. Smear tests for Candida spp. were performed in patients showing signs of inflammation of the oral mucosa. The prostheses were assessed for biological and technical complications. None of the functional prostheses released cobalt, whereas this was observed in 24 of 32 non-functional prostheses. None of the patients had contact allergy to cobalt. Of the 66 patients, 11 showed signs of inflammation of the oral mucosa, 2 had oral candidiasis, 16 had ill-fitting prostheses, and all had insufficient oral hygiene. Dental prostheses released cobalt during the fabrication stages, but not 1-5 years after insertion. No allergic reactions were observed. Signs of inflammation were related to candidiasis, insufficient oral hygiene, and ill-fitting prostheses. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Testing the visual consistency of web sites

    NARCIS (Netherlands)

    van der Geest, Thea; Loorbach, N.R.

    2005-01-01

    Consistency in the visual appearance of Web pages is often checked by experts, such as designers or reviewers. This article reports a card sort study conducted to determine whether users rather than experts could distinguish visual (in-)consistency in Web elements and pages. The users proved to

  9. An Examination of Three Tests of Visual-Motor Integration.

    Science.gov (United States)

    Aylward, Elizabeth H.; Schmidt, Steven

    1986-01-01

    Kindergarten children (N=103) were administered three tests of visual-motor integration: Bender Gestalt Test, Beery Developmental Test of Visual Motor Integration and Geometric Design subtest of the Wechsler Preschool and Primary Scale of Intelligence. Issues discussed include interscorer reliabilities, correlations among scores, correlations…

  10. Data Analytics and Visualization for Large Army Testing Data

    Science.gov (United States)

    2013-09-01

    Data Analytics and Visualization for Large Army Testing Data by Jerry Clarke, Kenneth Renard , and Brian Panneton ARL-TR-6572 September...Data Analytics and Visualization for Large Army Testing Data Jerry Clarke and Kenneth Renard Computational and Information Sciences...Testing Data 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Jerry Clarke, Kenneth Renard , and Brian Panneton

  11. The Revised Test of Visual-Motor Integration: Its Relation to the Test of Visual-Motor Integration and Bender Visual-Motor Gestalt Test for Regular Education Students.

    Science.gov (United States)

    Siewert, Julaine C.; Breen, Michael J.

    1983-01-01

    Compared three tests of visual-motor integration: The Revised Test of Visual-Motor Integration (VMI-R), the Test of Visual-Motor Integration (VMI), and the Bender Visual-Motor Gestalt Test (BG). Results showed significantly higher BG age equivalent scores. Highly significant correlations were found among all variables. (WAS)

  12. Characterization of protein degradation in serum-based lubricants during simulation wear testing of metal-on-metal hip prostheses.

    Science.gov (United States)

    Maskiewicz, Victoria K; Williams, Paul A; Prates, Sarah J; Bowsher, John G; Clarke, Ian C

    2010-08-01

    A size exclusion high performance liquid chromatography (SEC-HPLC) method has been developed which is capable of separation and quantitation of bovine serum albumin (BSA) and bovine serum globulin (BSG) components of serum-based lubricant (SBL) solutions. This allowed characterization of the stability profiles of these proteins when acting as lubricants during hip wear simulation, and identification of wear-specific mechanisms of degradation. Using cobalt-chromium metal-on-metal (MOM) hip joints, it was observed that BSA remained stable for up to 3 days (215K cycles) of wear testing after which the protein degraded in a fairly linear fashion. BSG on the other hand, began to degrade immediately and in a linear fashion with a rate constant of 5% per day. Loss of both proteins occurred via the formation of high molecular weight aggregates which precipitated out of solution. No fragmentation of the polypeptide backbone of either protein was observed. Data obtained suggest that protein degradation was not due to microbial contamination, denaturation at the air-water interface, or frictional heating of articulating joint surfaces in these studies. We conclude that the primary source of protein degradation during MOM simulation testing occurs via high shear rates experienced by SBL solutions at articulating surfaces, possibly coupled with metal-protein interactions occurring as new and reactive metal surfaces are generated during wear testing. The development of this analytical methodology will allow new studies to clarify the role of SBL solutions in wear simulation studies and the interactions and lubricating properties of serum proteins with prosthetic surfaces other than MOM.

  13. [Dice test--a simple method for assessment of visual acuity in infants with visual deficits].

    Science.gov (United States)

    Rohrschneider, K; Brill, B; Bayer, Y; Ahrens, P

    2010-07-01

    Determination of visual acuity in low vision infants or patients with additional cerebral retardation is difficult. In our low vision department we used dice of different sizes and colors as well as other defined objects to determine visual acuity (VA). In this study we compared the results of the dice test with conventional tests for measurement of visual acuity. A total of 88 children with different causes of visual impairment e.g. albinism, retinal scars, retinopathy of prematurity (ROP), achromatopsia and optic atrophy etc., were included in this longitudinal study. Median follow-up time was 8.7 years (range 2.9-18.9 years). The first reliable examination was performed between the ages of 4 and 24 months (median 11 months). We estimated VA depending on the edge length of the dice, which were recognized at a distance of 30 cm, while 4 mm complied with VA 20/200. Best corrected binocular visual acuity was compared between the dice test, measurement with the Lea symbols and with numbers or Landolt rings. Estimation of visual acuity using the dice test was possible at the end of the first year of life (median 11 months, range 4-27 months). Although observation is limited to visual acuity results in the low vision range between light reaction and 20/120 there was nearly complete agreement between all three VA measurements. Visual acuity ranged from light perception to 20/20 with a median of 20/100. In 39 patients visual acuity was 20/200 or less at the end of the observation period. Visual acuity estimation overestimated visual acuity only in 5 out of the 88 patients, while in all of the patients with later acuity measurements better than 20/200, our best value of 20/200 was achieved. Using simple visual objects, such as dice with different colors and size down to an edge length of 4 mm, it is possible to estimate visual acuity in low vision infants within the first year of life. This option is also very helpful in patients who are not able to perform other visual

  14. Repeated mobility testing for later artificial visual function evaluation

    Science.gov (United States)

    Velikay-Parel, M.; Ivastinovic, D.; Koch, M.; Hornig, R.; Dagnelie, G.; Richard, G.; Langmann, A.

    2007-03-01

    The study investigates the utility of a newly designed mobility test for repeated testing of visual function in patients with severe visual impairment and future application in evaluating functional progress in patients with artificial vision. Ten subjects divided into three groups based on visual acuity (VA) ranging from light perception to 20/200 and reduced visual field (VF) were included in the study. The mobility test consisted of using a set of four different but structurally similar and relatively short mazes having a constant number of obstacles of various sizes. The subjects, divided into three groups by acuity, passed through each course several times. In general, the patients with better VA had a larger extent of VF. Average speed and number of contacts were recorded as measures of performance. The average passing times of the groups through the courses were significantly different (p = 0.03), which was influenced by VA and VF. There was no significant difference in average number of contacts between the groups (p = 0.15). The mobility test proved to be appropriate for gaining statistically relevant results in repeated individual testing of patients with severe vision impairment. Results show promise for use this mobility test as a tool for assessing visual function of patients undergoing implantation of a visual prosthesis for artificial vision.

  15. Protective prostheses during radiation therapy

    International Nuclear Information System (INIS)

    Poole, T.S.; Flaxman, N.A.

    1986-01-01

    Current applications and complications in the use of radiotherapy for the treatment of oral malignancy are reviewed. Prostheses are used for decreasing radiation to vital structures not involved with the lesion but located in the field of radiation. With a program of oral hygiene and proper dental care, protective prostheses can help decrease greatly the morbidity seen with existing radiotherapy regimens

  16. Nuclear medicine and prostheses

    International Nuclear Information System (INIS)

    Bordenave, L.; Baquey, Ch.

    2004-01-01

    Whatever the bio-material, prosthesis or medical device concerned, from design to experimental then clinical validation, nuclear medicine (NM) techniques offer a unique opportunity in all indications, (in vitro diagnosis, in vivo diagnosis and therapy) to investigate, assess and predict the behaviour of the device, qualitatively and quantitatively. All research fields involving prostheses and their constitutive biomaterials may take advantage of NM. In order to review published works, one can analyze provided data according to two strategies: an upright one related to medical and surgical specialties that integrate NM and a more horizontal one, that is to describe what kind of contribution is brought by such investigations. The latter approach was preferred in our review. We discuss and illustrate benefits of NM in the following indications: as an in vitro tool, as an in vivo tool for the diagnosis i) of device integration in recipient, ii) of functional outcome after use or implantation, iii) and predictive assessment of undesirable side effects, iv) of occurrence of complications associated to the device implantation, v) of a new therapy efficiency; finally as in vivo tool of therapy. Tissue engineering and regenerative medicine domains with stem cell potential as well as that of medical device associated with vigilance are new fields in basic research and clinical assessment that seem increasingly promising for the nuclear physician and to which NM could and would contribute from molecule to integrated system in order to improve knowledge and achievement of prostheses. (author)

  17. Using Prosopagnosia to Test and Modify Visual Recognition Theory.

    Science.gov (United States)

    O'Brien, Alexander M

    2018-02-01

    Biederman's contemporary theory of basic visual object recognition (Recognition-by-Components) is based on structural descriptions of objects and presumes 36 visual primitives (geons) people can discriminate, but there has been no empirical test of the actual use of these 36 geons to visually distinguish objects. In this study, we tested for the actual use of these geons in basic visual discrimination by comparing object discrimination performance patterns (when distinguishing varied stimuli) of an acquired prosopagnosia patient (LB) and healthy control participants. LB's prosopagnosia left her heavily reliant on structural descriptions or categorical object differences in visual discrimination tasks versus the control participants' additional ability to use face recognition or coordinate systems (Coordinate Relations Hypothesis). Thus, when LB performed comparably to control participants with a given stimulus, her restricted reliance on basic or categorical discriminations meant that the stimuli must be distinguishable on the basis of a geon feature. By varying stimuli in eight separate experiments and presenting all 36 geons, we discerned that LB coded only 12 (vs. 36) distinct visual primitives (geons), apparently reflective of human visual systems generally.

  18. Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis

    DEFF Research Database (Denmark)

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill

    2002-01-01

    of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed...... a reduced blood oxygenation level dependent (BOLD) signal increase and a greater asymmetry in the visual cortex, compared with controls. The volume of visual cortical activation was significantly correlated to the result of the contrast sensitivity test. The BOLD signal increase correlated significantly......The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size...

  19. Functional MRI of the visual cortex and visual testing in patients with previous optic neuritis

    DEFF Research Database (Denmark)

    Langkilde, Annika Reynberg; Frederiksen, J.L.; Rostrup, Egill

    2002-01-01

    of the activated area and the signal change following ON, and compared the results with results of neuroophthalmological testing. We studied nine patients with previous acute ON and 10 healthy persons served as controls using fMRI with visual stimulation. In addition to a reduced activated volume, patients showed...... to both the results of the contrast sensitivity test and to the Snellen visual acuity. Our results indicate that fMRI is a useful method for the study of ON, even in cases where the visual acuity is severely impaired. The reduction in activated volume could be explained as a reduced neuronal input......The volume of cortical activation as detected by functional magnetic resonance imaging (fMRI) in the visual cortex has previously been shown to be reduced following optic neuritis (ON). In order to understand the cause of this change, we studied the cortical activation, both the size...

  20. A Review of the Non-Motoric Visual Gestalt Test and a Comparison with the Bender Visual-Motor Gestalt Test.

    Science.gov (United States)

    Elovitz, Gerald P.

    1979-01-01

    Measures of visual perception, such as the Bender Visual-Motor Gestalt Test (BVMGT) usually require motoric responding, i.e., drawing of figures. An alternative test, the Non-Motoric Visual Gestalt Test (NVGT), is compared with the BVMGT and shown to be superior in measuring visual-perceptual abilities that can discriminate poor and average…

  1. Comparing automated visual GUI testing tools: an industrial case study

    NARCIS (Netherlands)

    Garousi, V.; Afzal, Wasif; Caglar, Adem; Berk Isik, Ihsan; Baydan, Berker; Caylak, Seckin; Zeki Boyraz, Ahmet; Yolacan, Burak; Herkiloglu, Kadir

    2017-01-01

    Visual GUI testing (VGT) is a tool-driven technique, which uses image recognition for interaction and assertion of the behaviour of system under test. Motivated by a real industrial need, in the context of a large Turkish software and systems company providing solutions in the areas of defense and

  2. Hydrodynamic characteristics of mechanical heart valve prostheses in steady and pulsatile flow

    Czech Academy of Sciences Publication Activity Database

    Klimeš, František; Kořenář, Josef

    2002-01-01

    Roč. 9, č. 4 (2002), s. 249-258 ISSN 1210-2717 Institutional research plan: CEZ:AV0Z2060917 Keywords : mechanical heart valve prostheses * flow visualization- steady and pulsatile flow Subject RIV: BO - Biophysics

  3. Psychophysical testing of visual prosthetic devices: a call to establish a multi-national joint task force

    Science.gov (United States)

    Rizzo, Joseph F., III; Ayton, Lauren N.

    2014-04-01

    Recent advances in the field of visual prostheses, as showcased in this special feature of Journal of Neural Engineering , have led to promising results from clinical trials of a number of devices. However, as noted by these groups there are many challenges involved in assessing vision of people with profound vision loss. As such, it is important that there is consistency in the methodology and reporting standards for clinical trials of visual prostheses and, indeed, the broader vision restoration research field. Two visual prosthesis research groups, the Boston Retinal Implant Project (BRIP) and Bionic Vision Australia (BVA), have agreed to work cooperatively to establish a multi-national Joint Task Force. The aim of this Task Force will be to develop a consensus statement to guide the methods used to conduct and report psychophysical and clinical results of humans who receive visual prosthetic devices. The overarching goal is to ensure maximum benefit to the implant recipients, not only in the outcomes of the visual prosthesis itself, but also in enabling them to obtain accurate information about this research with ease. The aspiration to develop a Joint Task Force was first promulgated at the inaugural 'The Eye and the Chip' meeting in September 2000. This meeting was established to promote the development of the visual prosthetic field by applying the principles of inclusiveness, openness, and collegiality among the growing body of researchers in this field. These same principles underlie the intent of this Joint Task Force to enhance the quality of psychophysical research within our community. Despite prior efforts, a critical mass of interested parties could not congeal. Renewed interest for developing joint guidelines has developed recently because of a growing awareness of the challenges of obtaining reliable measurements of visual function in patients who are severely visually impaired (in whom testing is inherently noisy), and of the importance of

  4. Nickel deposited on the skin-visualization by DMG test.

    Science.gov (United States)

    Julander, Anneli; Skare, Lizbet; Vahter, Marie; Lidén, Carola

    2011-03-01

    Nickel is the most common cause of contact allergy and an important risk factor for hand eczema. Visualization techniques may be powerful in showing exposures. The dimethylglyoxime (DMG) test might be used to establish skin exposure to nickel. To develop and evaluate methods for visualization of nickel on the skin by the DMG test and hand imprints. Nickel solutions at different concentrations were applied in duplicate on the hands in healthy subjects (n = 5). The DMG test and acid wipe sampling for quantification were then performed. Hand imprints were taken after manipulation of nickel-releasing tools (n = 1), and in workers performing their normal tasks (n = 7). The imprints were developed by the DMG test. The DMG test on hands gave positive results in all subjects. The lowest concentration giving rise to a colour change was set to 0.13 µg/cm(2) for DMG testing on skin. DMG test-developed imprints worked well except when hands were heavily contaminated by other particles/dust. The DMG test may be used as a simple and powerful tool for visualization of nickel on skin. DMG test-developed hand imprints may, in the future, be used for semi-quantitative or quantitative exposure assessment. © 2011 John Wiley & Sons A/S.

  5. Urinary dipstick proteinuria testing: does automated strip analysis offer an advantage over visual testing?

    Science.gov (United States)

    De Silva, Dane A; Halstead, Anne C; Côté, Anne-Marie; Sabr, Yasser; von Dadelszen, Peter; Magee, Laura A

    2014-07-01

    To compare the diagnostic test properties of automated and visually read urine dipstick screening for detection of a random protein:creatinine ratio (PrCr) ≥ 30 mg/mmol. Urine samples were collected prospectively from 160 women attending high-risk maternity clinics at a tertiary care facility. Samples were divided into two aliquots; one aliquot was tested using two different urine test strips, one read visually and one by an automated reader. A second aliquot of the same urine was analyzed for urinary protein and creatinine. Performance of visual and automated dipstick results (proteinuria ≥ 1+) were compared for detection of PrCr ≥ 30 mg/mmol using non-dilute urine samples (urinary creatinine ≥ 3 mmol/L). Both urine test strips showed low sensitivity (visual 56.0% and automated 53.8%). Positive likelihood ratios were 15.0 for visual dipstick testing (95% CI 5.9 to 37.9) and 24.6 for automated (95% CI 7.6 to 79.6). Negative likelihood ratios were 0.46 for visual dipstick testing (95% CI 0.29 to 0.71) and 0.47 for automated (95% CI 0.31 to 0.72). Automated dipstick testing was not superior to visual testing for detection of proteinuria in pregnant women in a primarily outpatient setting. Sensitivity may depend on the test strips and/or analyzer used.

  6. Testing a Conceptual Change Model Framework for Visual Data

    Science.gov (United States)

    Finson, Kevin D.; Pedersen, Jon E.

    2015-01-01

    An emergent data analysis technique was employed to test the veracity of a conceptual framework constructed around visual data use and instruction in science classrooms. The framework incorporated all five key components Vosniadou (2007a, 2007b) described as existing in a learner's schema: framework theory, presuppositions, conceptual domains,…

  7. IMPROVED HEALING OF SMALL-CALIBER POLYTETRAFLUOROETHYLENE VASCULAR PROSTHESES BY INCREASED HYDROPHILICITY AND BY ENLARGED FIBRIL LENGTH - AN EXPERIMENTAL-STUDY IN RATS

    NARCIS (Netherlands)

    STRONCK, JWS; VANDERLEI, B; WILDEVUUR, CRH

    This study was undertaken to test whether increasing the hydrophilicity of small-caliber polytetrafluoroethylene vascular prostheses by alcohol pretreatment or increasing their fibril length might improve their healing without affecting their patency. Polytetrafluoroethylene vascular prostheses

  8. Designing and testing lightweight shoulder prostheses with hybrid actuators for movements involved in typical activities of daily living and impact absorption

    Directory of Open Access Journals (Sweden)

    Sekine M

    2015-07-01

    Full Text Available Masashi Sekine,1,2 Kahori Kita,1 Wenwei Yu1 1Center for Frontier Medical Engineering, 2Graduate School of Engineering, Chiba University, Chiba, Japan Abstract: Unlike forearm amputees, transhumeral amputees have residual stumps that are too small to provide a sufficient range of operation for their prosthetic parts to perform usual activities of daily living. Furthermore, it is difficult for small residual stumps to provide sufficient impact absorption for safe manipulation in daily living, as intact arms do. Therefore, substitution of upper limb function in transhumeral amputees requires a sufficient range of motion and sufficient viscoelasticity for shoulder prostheses under critical weight and dimension constraints. We propose the use of two different types of actuators, ie, pneumatic elastic actuators (PEAs and servo motors. PEAs offer high power-to-weight performance and have intrinsic viscoelasticity in comparison with motors or standard industrial pneumatic cylinder actuators. However, the usefulness of PEAs in large working spaces is limited because of their short strokes. Servo motors, in contrast, can be used to achieve large ranges of motion. In this study, the relationship between the force and stroke of PEAs was investigated. The impact absorption of both types of actuators was measured using a single degree-of-freedom prototype to evaluate actuator compliance for safety purposes. Based on the fundamental properties of the actuators identified, a four degree-of-freedom robotic arm is proposed for prosthetic use. The configuration of the actuators and functional parts was designed to achieve a specified range of motion and torque calculated from the results of a simulation of typical movements performed in usual activities of daily living. Our experimental results showed that the requirements for the shoulder prostheses could be satisfied. Keywords: shoulder prosthesis, hybrid actuation, pneumatic elastic actuator, antagonistic

  9. Designing and testing lightweight shoulder prostheses with hybrid actuators for movements involved in typical activities of daily living and impact absorption.

    Science.gov (United States)

    Sekine, Masashi; Kita, Kahori; Yu, Wenwei

    2015-01-01

    Unlike forearm amputees, transhumeral amputees have residual stumps that are too small to provide a sufficient range of operation for their prosthetic parts to perform usual activities of daily living. Furthermore, it is difficult for small residual stumps to provide sufficient impact absorption for safe manipulation in daily living, as intact arms do. Therefore, substitution of upper limb function in transhumeral amputees requires a sufficient range of motion and sufficient viscoelasticity for shoulder prostheses under critical weight and dimension constraints. We propose the use of two different types of actuators, ie, pneumatic elastic actuators (PEAs) and servo motors. PEAs offer high power-to-weight performance and have intrinsic viscoelasticity in comparison with motors or standard industrial pneumatic cylinder actuators. However, the usefulness of PEAs in large working spaces is limited because of their short strokes. Servo motors, in contrast, can be used to achieve large ranges of motion. In this study, the relationship between the force and stroke of PEAs was investigated. The impact absorption of both types of actuators was measured using a single degree-of-freedom prototype to evaluate actuator compliance for safety purposes. Based on the fundamental properties of the actuators identified, a four degree-of-freedom robotic arm is proposed for prosthetic use. The configuration of the actuators and functional parts was designed to achieve a specified range of motion and torque calculated from the results of a simulation of typical movements performed in usual activities of daily living. Our experimental results showed that the requirements for the shoulder prostheses could be satisfied.

  10. Simple Instrumental and Visual Tests for Nonlaboratory Environmental Control

    Directory of Open Access Journals (Sweden)

    L. P. Eksperiandova

    2016-01-01

    Full Text Available Proposed are simple and available techniques that can be used for rapid and reliable environmental control specifically of natural water by means of instrumental and visual tests in outdoor conditions. Developed are the chemical colorimetric modes for fast detection of socially dangerous trace impurities in water such as Co(II, Pd(II, and Rh(III as well as NO2--ions and Fe(III serving as model impurities. Application of portable digital devices and scanner allows estimating the color coordinates and increasing the accuracy and sensitivity of the tests. The combination of complex formation with preconcentration of colored complexes replaces the sensitive but time-consuming and capricious kinetic method that is usually used for this purpose at the more convenient and reliable colorimetric method. As the test tools, the following ones are worked out: polyurethane foam tablets with sorbed colored complexes, the two-layer paper sandwich packaged in slide adapter and saturated by reagents, and polyethylene terephthalate blister with dried reagents. Fast analysis of polyurethane foam tablets is realized using a pocket digital RGB-colorimeter or portable photometer. Express analysis of two-layer paper sandwich or polyethylene terephthalate blister is realized by visual and instrumental tests. The metrological characteristics of the developed visual and instrumental express analysis techniques are estimated.

  11. [Abdominal wall prostheses. Biomechanic and histological study].

    Science.gov (United States)

    Rath, A M; Zhang, J; Amouroux, J; Chevrel, J P

    1996-01-01

    The best prosthetic material is one which provides the best mechanical resistance with the best biological tolerance. In order to assess the mechanical and histological properties of abdominal wall prostheses, we performed experimental tests in animal models comparing four materials: polypropylene, dacron, polyglactine 910 and a dacron-polyglactine 910 composite. One hundred thirty rabbits were used including 10 controls and 120 test animals. A medial laparotomy was closed with an antemuscular aponevrotic prosthesis in the test animals. Animals were sacrificed at one, two and three months after the operation. Abdominal wall and prosthesis samples were tested to determine resistance to pressure and extension, deformability and elasticity. Histology tests were also done to determine resistance quality and biological tolerance. Dacron was tolerated best and was less resistant than polypropylene, though resistance was satisfactory. There was no advantage with polyglactine compared with non-resorbable prostheses; its only indication would be a septic site. The composite material tested had a resistance comparable with that of dacron but was less well tolerated.

  12. The Pareidolia Test: A Simple Neuropsychological Test Measuring Visual Hallucination-Like Illusions.

    Directory of Open Access Journals (Sweden)

    Yasuyuki Mamiya

    Full Text Available Visual hallucinations are a core clinical feature of dementia with Lewy bodies (DLB, and this symptom is important in the differential diagnosis and prediction of treatment response. The pareidolia test is a tool that evokes visual hallucination-like illusions, and these illusions may be a surrogate marker of visual hallucinations in DLB. We created a simplified version of the pareidolia test and examined its validity and reliability to establish the clinical utility of this test.The pareidolia test was administered to 52 patients with DLB, 52 patients with Alzheimer's disease (AD and 20 healthy controls (HCs. We assessed the test-retest/inter-rater reliability using the intra-class correlation coefficient (ICC and the concurrent validity using the Neuropsychiatric Inventory (NPI hallucinations score as a reference. A receiver operating characteristic (ROC analysis was used to evaluate the sensitivity and specificity of the pareidolia test to differentiate DLB from AD and HCs.The pareidolia test required approximately 15 minutes to administer, exhibited good test-retest/inter-rater reliability (ICC of 0.82, and moderately correlated with the NPI hallucinations score (rs = 0.42. Using an optimal cut-off score set according to the ROC analysis, and the pareidolia test differentiated DLB from AD with a sensitivity of 81% and a specificity of 92%.Our study suggests that the simplified version of the pareidolia test is a valid and reliable surrogate marker of visual hallucinations in DLB.

  13. The Pareidolia Test: A Simple Neuropsychological Test Measuring Visual Hallucination-Like Illusions.

    Science.gov (United States)

    Mamiya, Yasuyuki; Nishio, Yoshiyuki; Watanabe, Hiroyuki; Yokoi, Kayoko; Uchiyama, Makoto; Baba, Toru; Iizuka, Osamu; Kanno, Shigenori; Kamimura, Naoto; Kazui, Hiroaki; Hashimoto, Mamoru; Ikeda, Manabu; Takeshita, Chieko; Shimomura, Tatsuo; Mori, Etsuro

    2016-01-01

    Visual hallucinations are a core clinical feature of dementia with Lewy bodies (DLB), and this symptom is important in the differential diagnosis and prediction of treatment response. The pareidolia test is a tool that evokes visual hallucination-like illusions, and these illusions may be a surrogate marker of visual hallucinations in DLB. We created a simplified version of the pareidolia test and examined its validity and reliability to establish the clinical utility of this test. The pareidolia test was administered to 52 patients with DLB, 52 patients with Alzheimer's disease (AD) and 20 healthy controls (HCs). We assessed the test-retest/inter-rater reliability using the intra-class correlation coefficient (ICC) and the concurrent validity using the Neuropsychiatric Inventory (NPI) hallucinations score as a reference. A receiver operating characteristic (ROC) analysis was used to evaluate the sensitivity and specificity of the pareidolia test to differentiate DLB from AD and HCs. The pareidolia test required approximately 15 minutes to administer, exhibited good test-retest/inter-rater reliability (ICC of 0.82), and moderately correlated with the NPI hallucinations score (rs = 0.42). Using an optimal cut-off score set according to the ROC analysis, and the pareidolia test differentiated DLB from AD with a sensitivity of 81% and a specificity of 92%. Our study suggests that the simplified version of the pareidolia test is a valid and reliable surrogate marker of visual hallucinations in DLB.

  14. [Biomechanic considerations in wrist prostheses].

    Science.gov (United States)

    Kapandji, A I

    1992-01-01

    At the present time, in disorders of the wrist, avulsion of the first carpal row is the most commonly used technique as a last resort. However, there are many wrist prostheses, which are reviewed here. Roughly, they belong to two families: the three axis prostheses (spherical) that cannot transmit to the hand the pronation supination torque, because of their geometrical characteristics, and the two axis prostheses (universal joint) that are able to transmit this movement. The characteristics of future prostheses must include: based on the "universal joint" principle, occupy minimum space, isometric, maintain tendon tension, an axis identical to the true axis of the wrist, to maintain the hand in line with the forearm, fixed without cement but, not shortened with time, possibilities of mechanical flexibility immediately and lastingly stable, to be easily replaced modularly. This ideal prosthesis will certainly exist one day and will take the place of the first carpal row avulsion. In the meantime, this technique will still have a long use.

  15. PP025. Urinary dipstick proteinuria testing - Does automated strip analysis offer an advantage over visual testing?

    Science.gov (United States)

    De Silva, D A; Halstead, C; Côté, A-M; Sabr, Y; von Dadelszen, P; Magee, L A

    2012-07-01

    The visual urinary test strip is widely accepted for screening for proteinuria in pregnancy, given the convenience of the method and its low cost. However, test strips are known to lack sensitivity and specificity. The 2010 NICE (National Institute for Health and Clinical Excellence) guidelines for management of pregnancy hypertension have recommended the use of an automated test strip reader to confirm proteinuria (http://nice.org.uk/CG107). Superior diagnostic test performance of an automated (vs. visual) method has been proposed based on reduced subjectivity. To compare the diagnostic test properties of automated vs. visual read urine dipstick testing for detection of a random protein:creatinine ratio (PrCr) of ⩾30mg/mmol. In this prospective cohort study, consecutive inpatients or outpatients (obstetric medicine and high-risk maternity clinics) were evaluated at a tertiary care facility. Random midstream urine samples (obtained as part of normal clinical care) were split into two aliquots. The first underwent a point-of-care testing for proteinuria using both visual (Multistix 10SG, Siemens Healthcare Diagnostics, Inc., Tarrytown NY) and automated (Chemstrip 10A, Roche Diagnostics, Laval QC) test strips, the latter read by an analyser (Urisys 1100®, Roche Diagnostics, Laval QC). The second aliquot was sent to the hospital laboratory for analysis of urinary protein using a pyrocatechol violet molybdate dye-binding method, and urinary creatinine using an enzymatic method, both on an automated analyser (Vitros® 5,1 FS or Vitros® 5600, Ortho-Clinical Diagnostics, Rochester NY); random PrCr ratios were calculated in the laboratory. Following exclusion of dilute samples with urinary creatinine concentration analysis. Both visual and automated read urinary dipstick testing showed low sensitivity (56.0% and 53.9%, respectively). Positive likelihood ratios (LR+) and 95% CI were 15.0 [5.9,37.9] and 24.6 [7.6,79.6], respectively. Negative LR (LR-) were 0.46 [0

  16. Effect of testing position on dynamic visual acuity.

    Science.gov (United States)

    Danenbaum, Elizabeth; Chilingaryan, Gevorg; Fung, Joyce

    2008-12-01

    To investigate the effect of altering testing position on dynamic visual acuity (DVA) in vestibulopathic adults. Quasiexperimental research. Outpatient vestibular program. Twelve vestibulopathic adults with impaired DVA in the sitting position. DVA scores were collected during (1) sitting, (2) standing comfortably, and (3) semitandem standing as subjects viewed a vision (E) chart 3.48 m in front of them. DVA was obtained as the head was passively moved by the evaluator at a frequency of 1.5 Hz in both horizontal and vertical directions. A further subgroup of subjects (n=5) was retested after performing the "viewing x1" gaze stability home exercise four times daily (1 minute duration in the horizontal direction while sitting) for 2 months. Noncomputerized DVA score. The DVA score remained constant independent of testing position as the Friedman test did not reveal any significant differences in the DVA scores in the horizontal or vertical direction. Subjects who improved after performing the viewing x1 exercise in the horizontal direction in the sitting position tended to have the same improvement in DVA in all three positions. The results of this study show that DVA score is independent of testing position. This is clinically important since it shows that the results of DVA testing in one position are valid for other positions and that subjects can be trained to improve their DVA in a sitting posture while having carry-over effects to other, more challenging postures.

  17. Test-retest reliability of visual-evoked potential habituation.

    Science.gov (United States)

    Rauschel, Veronika; Ruscheweyh, Ruth; Krafczyk, Siegbert; Straube, Andreas

    2016-08-01

    Habituation of visual-evoked potentials (VEPs) is typically described as deficient interictally in migraine patients, supposedly indicating altered cortical excitability. Use of this parameter for monitoring changes over time, e.g. under treatment, requires demonstration of test-retest reliability. VEPs were recorded interictally in 41 episodic migraine patients and 40 controls. N75-P100 amplitudes were measured over six consecutive blocks of 75 VEPs each. Amplitude regression slopes and block ratios were used to quantify VEP habituation. Test-retest reliability was assessed over 15 minutes and two to three weeks. Controls showed significantly more negative VEP habituation slopes than migraine patients (-0.21 ± 0.40 vs. 0.04 ± 0.46 µV/block, p test to two- to three-week retest (p test-retest correlations were mostly poor both in migraine patients and controls (intraclass correlation coefficients, 15 minutes: -0.13 to 0.30, two to three weeks: 0.07 to 0.59). Deficient VEP habituation in migraine was confirmed. However, the test-retest reliability of VEP habituation was rather weak. Therefore, we suggest that VEP habituation should be used for evaluation of cortical excitability under treatment only at the group level and only when a control group with sham treatment is included. © International Headache Society 2015.

  18. Cementless Hydroxyapatite Coated Hip Prostheses

    Directory of Open Access Journals (Sweden)

    Antonio Herrera

    2015-01-01

    Full Text Available More than twenty years ago, hydroxyapatite (HA, calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality.

  19. Cementless Hydroxyapatite Coated Hip Prostheses

    Science.gov (United States)

    Herrera, Antonio; Mateo, Jesús; Gil-Albarova, Jorge; Lobo-Escolar, Antonio; Ibarz, Elena; Gabarre, Sergio; Más, Yolanda

    2015-01-01

    More than twenty years ago, hydroxyapatite (HA), calcium phosphate ceramics, was introduced as a coating for cementless hip prostheses. The choice of this ceramic is due to its composition being similar to organic apatite bone crystals. This ceramic is biocompatible, bioactive, and osteoconductive. These qualities facilitate the primary stability and osseointegration of implants. Our surgical experience includes the implantation of more than 4,000 cementless hydroxyapatite coated hip prostheses since 1990. The models implanted are coated with HA in the acetabulum and in the metaphyseal area of the stem. The results corresponding to survival and stability of implants were very satisfactory in the long-term. From our experience, HA-coated hip implants are a reliable alternative which can achieve long term survival, provided that certain requirements are met: good design selection, sound choice of bearing surfaces based on patient life expectancy, meticulous surgical technique, and indications based on adequate bone quality. PMID:25802848

  20. Comparison of Learning Disabled Children's Performance on Bender Visual-Motor Gestalt Test and Beery's Developmental Test of Visual Motor Integration.

    Science.gov (United States)

    Skeen, Judith A.; And Others

    1982-01-01

    A comparison was made of the performance of 30 learning-disabled students on the Bender Visual-Motor Gestalt Test and the Beery Developmental Test of Visual Motor Integration. A significant correlation of -.72 was obtained. No significant difference was found in estimations of age equivalents. (Author)

  1. Differential functioning of Bender Visual-Motor Gestalt Test items.

    Science.gov (United States)

    Sisto, Fermino Fernandes; Dos Santos, Acácia Aparecida Angeli; Noronha, Ana Paula Porto

    2010-02-01

    Differential Item Functioning (DIF) refers to items that do not function the same way for comparable members of different groups. The present study focuses on analyzing and classifying sex-related differential item functioning in the Bender Visual-Motor Gestalt Test. Subjects were 1,052 children attending public schools (513 boys, 539 girls, ages 6-10 years). The protocols were scored using the Bender Graduated Scoring System, which evaluates only the distortion criterion using the Rasch logistic response model. The scoring system fit the Rasch model, although two items were found to be biased by sex. When analyzing differential functioning of items for boys and girls separately, the number of differentially functioning items was equal.

  2. Heat generated by knee prostheses.

    Science.gov (United States)

    Pritchett, James W

    2006-01-01

    Temperature sensors were placed in 50 knees in 25 patients who had one or both joints replaced. Temperature recordings were made before walking, after walking, and after cycling. The heat generated in healthy, arthritic, and replaced knees was measured. The knee replacements were done using eight different prostheses. A rotating hinge knee prosthesis generated a temperature increase of 7 degrees C in 20 minutes and 9 degrees C in 40 minutes. An unconstrained ceramic femoral prosthesis articulating with a polyethylene tibial prosthesis generated a temperature increase of 4 degrees C compared with a healthy resting knee. The other designs using a cobalt-chrome alloy and high-density polyethylene had temperature increases of 5 degrees-7 degrees C with exercise. Frictional heat generated in a prosthetic knee is not immediately dissipated and may result in wear, creep, and other degenerative processes in the high-density polyethylene. Extended periods of elevated temperature in joints may inhibit cell growth and perhaps contribute to adverse performance via bone resorption or component loosening. Prosthetic knees generate more heat with activity than healthy or arthritic knees. More-constrained knee prostheses generate more heat than less-constrained prostheses. A knee with a ceramic femoral component generates less heat than a knee with the same design using a cobalt-chromium alloy.

  3. Implant placement under existing removable dental prostheses and its effect on masticatory performance.

    Science.gov (United States)

    Wolfart, S; Wolf, K; Brunzel, S; Wolfart, M; Caliebe, A; Kern, M

    2016-12-01

    The aim of this within-subject study was to evaluate the outcome with implant-tooth-supported removable partial dental prostheses (RPDP group) and implant-supported removable complete dental prostheses (edentulous group) in terms of masticatory performance and self-assessment. Thirty patients participated in this prospective clinical study (RPDP group: n = 12; edentulous group: n = 18). The prostheses were supported in strategically advantageous regions by placing implants with ball attachments and corresponding matrices in the existing dentures. The masticatory performance was evaluated with the Swallowing Threshold Test Index (STTI), the number of chewing strokes, and the time needed until swallowing at pre-treatment and 6 weeks after integration of ball attachments. Additionally, patients scored chewing satisfaction before and after implantation on a visual analogue scale. The STTI increased significantly (p ≤ 0.05) after implant therapy in the edentulous group but not in the RPDP group. Furthermore, the STTI was significantly higher (p ≤ 0.05) in the RPDP group than in the edentulous group at pre-treatment, however, not after therapy (P > 0.05). All patients were very satisfied after therapy concerning ability of speaking, chewing, and stability of their prosthesis. Patients of the edentulous group benefit more from strategically placed implants under the existing dentures than patients from the RPDP group. However, according to the subjective assessment, the chewing satisfaction generally increased for both groups after implant therapy. Patients with a strongly reduced dentition and edentulous patients benefit from strategically placed implants under the existing removable dentures.

  4. Sensory feedback add-on for upper-limb prostheses.

    Science.gov (United States)

    Fallahian, Nader; Saeedi, Hassan; Mokhtarinia, Hamidreza; Tabatabai Ghomshe, Farhad

    2017-06-01

    Sensory feedback systems have been of great interest in upper-limb prosthetics. Despite tremendous research, there are no commercial modality-matched feedback systems. This article aims to introduce the first detachable and feedback add-on option that can be attached to in-use prostheses. A sensory feedback system was tested on a below-elbow myoelectric prosthesis. The aim was to have the amputee grasp fragile objects without crushing while other accidental feedback sources were blocked. A total of 8 successful trials (out of 10) showed that sensory feedback system decreased the amputee's visual dependency by improving awareness of his prosthesis. Sensory feedback system can be used either as post-fabrication (prosthetic add-on option) or para-fabrication (incorporated into prosthetic design). The use of these direct feedback systems can be explored with a current prosthesis before ordering new high-tech prosthesis. Clinical relevance This technical note introduces the first attach/detach-able sensory feedback system that can simply be added to in-use (myo)electric prosthesis, with no obligation to change prosthesis design or components.

  5. Personality Testing with Visually Impaired Adults in Applied Occupational Settings: A Review of the Literature.

    Science.gov (United States)

    Reid, Juliet

    2000-01-01

    This article describes controversies over the use of personality tests with adults with visual impairments in applied occupational testing. It reviews studies of personality profiles of sighted individuals and individuals with visual impairments and studies in which the content of items has been adapted for adults who are visually impaired.…

  6. Introduction to flow visualization system in SPARC test facility

    International Nuclear Information System (INIS)

    Lee, Wooyoung; Song, Simon; Na, Young Su; Hong, Seong Wan

    2016-01-01

    The released hydrogen can be accumulated and mixed by steam and air depending on containment conditions under severe accident, which generates flammable mixture. Hydrogen explosion induced by ignition source cause severe damage to a structure or facility. Hydrogen risk regarding mixing, distribution, and combustion has been identified by several expert groups and studied actively since TMI accident. A large-scale thermal-hydraulic experimental facility is required to simulate the complex severe accident phenomena in the containment building. We have prepared the test facility, called the SPARC (Spray, Aerosol, Recombiner, Combustion), to resolve the international open issues regarding hydrogen risk. Gas mixing and stratification test using helium instead of hydrogen and estimation of a stratification surface erosion of helium owing to the vertical jet flow will be performed in SPARC. The measurement system is need to observe the gas flow in the large scale test facility such as SPARC. The PIV (particle image velocimetry) system have been installed to visualize gas flow. We are preparing the test facility, called the SPARC, for estimation the thermal-hydraulic process of hydrogen in a closed containment building and the PIV system for quantitative assessment of gas flow. In particular, we will perform gas mixing and erosion of stratification surface test using helium which is the replacement of hydrogen. It will be evaluated by measuring 2D velocity field using the PIV system. The PIV system mainly consists of camera, laser and tracer particle. Expected maximum size of FOV is 750 x 750 mm 2 limited by focal length of lens and high power laser corresponding to 425mJ/pulse at 532 wavelength is required due to large FOV

  7. Introduction to flow visualization system in SPARC test facility

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Wooyoung; Song, Simon [Hanyang University, Seoul (Korea, Republic of); Na, Young Su; Hong, Seong Wan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The released hydrogen can be accumulated and mixed by steam and air depending on containment conditions under severe accident, which generates flammable mixture. Hydrogen explosion induced by ignition source cause severe damage to a structure or facility. Hydrogen risk regarding mixing, distribution, and combustion has been identified by several expert groups and studied actively since TMI accident. A large-scale thermal-hydraulic experimental facility is required to simulate the complex severe accident phenomena in the containment building. We have prepared the test facility, called the SPARC (Spray, Aerosol, Recombiner, Combustion), to resolve the international open issues regarding hydrogen risk. Gas mixing and stratification test using helium instead of hydrogen and estimation of a stratification surface erosion of helium owing to the vertical jet flow will be performed in SPARC. The measurement system is need to observe the gas flow in the large scale test facility such as SPARC. The PIV (particle image velocimetry) system have been installed to visualize gas flow. We are preparing the test facility, called the SPARC, for estimation the thermal-hydraulic process of hydrogen in a closed containment building and the PIV system for quantitative assessment of gas flow. In particular, we will perform gas mixing and erosion of stratification surface test using helium which is the replacement of hydrogen. It will be evaluated by measuring 2D velocity field using the PIV system. The PIV system mainly consists of camera, laser and tracer particle. Expected maximum size of FOV is 750 x 750 mm{sup 2} limited by focal length of lens and high power laser corresponding to 425mJ/pulse at 532 wavelength is required due to large FOV.

  8. Hip prostheses in young adults. Surface prostheses and short-stem prostheses.

    Science.gov (United States)

    Gallart, X; Riba, J; Fernández-Valencia, J A; Bori, G; Muñoz-Mahamud, E; Combalia, A

    The poor results obtained in young patients when using a conventional prosthesis led to the resurgence of hip resurfacing to find less invasive implants for the bone. Young patients present a demand for additional activity, which makes them a serious challenge for the survival of implants. In addition, new information technologies contribute decisively to the preference for non-cemented prostheses. Maintaining quality of life, preserving the bone and soft tissues, as well as achieving a very stable implant, are the goals of every hip orthopaedic surgeon for these patients. The results in research point to the use of smaller prostheses, which use the metaphyseal zone more and less the diaphyseal zone, and hence the large number of the abovementioned short stem prostheses. Both models are principally indicated in the young adult. Their revision should be a more simple operation, but this is only true for hip resurfacing, not for short stems. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. The Correlation between Subjective and Objective Visual Function Test in Optic Neuropathy Patients

    Directory of Open Access Journals (Sweden)

    Ungsoo Kim

    2012-10-01

    Full Text Available Purpose: To investigate the correlation between visual acuity and quantitative measurements of visual evoked potentials (VEP, optical coherence tomography (OCT, and visual field test (VF in optic neuropathy patients. Methods: We evaluated 28 patients with optic neuropathy. Patients who had pale disc, visual acuity of less than 0.5 and abnormal visual field defect were included. At the first visit, we performed visual acuity and VF as subjective methods and OCT and VEP as objective methods. In the spectral domain OCT, rim volume, average and temporal quadrant retinal nerve fiber layer (RNFL thickness were measured. And pattern VEP (N75, P100, N135 latency, and P100 amplitude and Humphrey 24-2 visual field test (mean deviation and pattern standard deviation were obtained. Using Spearman's correlation coefficient, the correlation between visual acuity and various techniques were assessed. Results: Visual acuity was most correlated with the mean deviation of Humphrey perimetry.

  10. Visual field measurement with motion sensitivity screening test

    African Journals Online (AJOL)

    Eye disease is a frequent complication of onchocerciasis in countries where the diseasc is highly endemic. It has been shown that early ocular lesions which manifest as visual field defects or reduction in visual acuity can be reversed following treatment with ivermectin. At the community level, it is important to detect.

  11. Visual Field Measurement with Motion Sensitivity Screening Test in ...

    African Journals Online (AJOL)

    Eye disease is a frequent complication of onchocerciasis in countrise where the disease is highly endemic. It has been shown that early ocular lesions which manifest as visual field defects or reduction in visual acuity can be reversed following treatment with ivermectin. At the community level, it is important to detect ...

  12. Confrontation visual field testing in routine ophthalmic practice ...

    African Journals Online (AJOL)

    Results: Two patients had symptoms of headache and visual blurring, galactorrhea and amenorrhea. A right homonymous hemianopia and bitemporal hemianopia respectively were detected on CVF. The 3rd patient complained of visual blurring and bumping into objects following an assault to the head. CVF detected ...

  13. Testing the Visual Soil Assessment tool on Estonian farm fields

    Science.gov (United States)

    Reintam, Endla; Are, Mihkel; Selge, Are

    2017-04-01

    Soil quality estimation plays important role in decision making on farm as well on policy level. Sustaining the production ability and good health of the soil the chemical, physical and biological indicators should be taken into account. The system to use soil chemical parameters is usually quite well established in most European counties, including Estonia. However, measuring soil physical properties, such bulk density, porosity, penetration resistance, structural stability ect is time consuming, needs special tools and is highly weather dependent. In that reason these parameters are excluded from controllable quality parameters in policy in Estonia. Within the project "Interactive Soil Quality Assessment in Europe and China for Agricultural Productivity and Environmental Resilience" (iSQAPER) the visual soil assessment (VSA) tool was developed for easy detection of soil quality as well the different soil friendly agricultural management practices (AMP) were detected. The aim of current study was to test the VSA tool on Estonian farm fields under different management practices and compare the results with laboratory measurements. The main focus was set on soil physical parameters. Next to the VSA, the undisturbed soil samples were collected from the depth of 5-10 cm and 25-30 cm. The study revealed that results of a visually assessed soil physical parameters, such a soil structure, soil structural stability, soil porosity, presence of tillage pan, were confirmed by laboratory measurements in most cases. Soil water stable structure measurement on field (on 1 cm2 net in one 1 l box with 4-6 cm air dry clods for 5-10 min) underestimated very well structured soil on grassland and overestimated the structure aggregates stability of compacted soil. The slightly better soil quality was detected under no-tillage compared to ploughed soils. However, the ploughed soil got higher quality points compared with minimum tillage. The slurry application (organic manuring) had

  14. Satisfaction and quality of life with palatal positioned implants in severely atrophic maxillae versus conventional implants supporting fixed full-arch prostheses.

    Science.gov (United States)

    Candel-Marti, Eugenia; Peñarrocha-Oltra, David; Peñarrocha-Diago, Maria; Peñarrocha-Diago, Miguel

    2015-11-01

    To evaluate satisfaction and quality of life in patients with palatal positioned implants supporting fixed full-arch prostheses to rehabilitate edentulous maxillae with horizontal atrophy and compare them with conventional well-centered implants placed in non-atrophic supporting fixed full-arch prostheses. A clinical retrospective study was performed of patients that were rehabilitated with full-arch fixed implant-supported maxillary prostheses and had a minimum follow-up of 5 years after implant loading. Patients were divided into 2 groups: patients with class IV maxilla according to Cawood and Howell and treated with palatal positioned implants (test) and with class III maxilla and treated with implants well-centered in the alveolar ridge and completely surrounded by bone (control). Ten-cm visual analogue scales (VAS) (range 1-10) and the OHIP-14 (Oral Health Impact Profile) questionnaire were used respectively to estimate patient satisfaction and quality of life after implant therapy. Statistical analysis was performed applying Mann-Whitney Test using alpha set at 0.05. Mean global and specific satisfaction--except for self-esteem--were superior for the test group than the control group, although differences were not statistically significant. Regarding quality of life, the reported incidence of problems was lower in the test group for all the studied items except for 'problems at work'. However, differences were not statistically significant in any case. Despite the limitations of the study (retrospective and nonrandomized design) the results suggest that the prosthesis design needed to rehabilitate palatally positioned implants (more coverage of palate) does not lead to lower satisfaction and quality of life of patients, compared to patients treated with implants placed centered and conventional design prostheses that do not cover the palate.

  15. Opposite brain laterality in analogous auditory and visual tests.

    Science.gov (United States)

    Oltedal, Leif; Hugdahl, Kenneth

    2017-11-01

    Laterality for language processing can be assessed by auditory and visual tasks. Typically, a right ear/right visual half-field (VHF) advantage is observed, reflecting left-hemispheric lateralization for language. Historically, auditory tasks have shown more consistent and reliable results when compared to VHF tasks. While few studies have compared analogous tasks applied to both sensory modalities for the same participants, one such study by Voyer and Boudreau [(2003). Cross-modal correlation of auditory and visual language laterality tasks: a serendipitous finding. Brain Cogn, 53(2), 393-397] found opposite laterality for visual and auditory language tasks. We adapted an experimental paradigm based on a dichotic listening and VHF approach, and applied the combined language paradigm in two separate experiments, including fMRI in the second experiment to measure brain activation in addition to behavioural data. The first experiment showed a right-ear advantage for the auditory task, but a left half-field advantage for the visual task. The second experiment, confirmed the findings, with opposite laterality effects for the visual and auditory tasks. In conclusion, we replicate the finding by Voyer and Boudreau (2003) and support their interpretation that these visual and auditory language tasks measure different cognitive processes.

  16. Bender Visual-Motor Gestalt Test in adolescents: relationship between visual-motor development and the Tanner Stages.

    Science.gov (United States)

    Keppeke, Lívia de Freitas; Cintra, Isa de Pádua; Schoen, Teresa Helena

    2013-08-01

    Visual-motor skill is fundamental to human development and is an important component of psychological evaluations. The goal of the present study was to determine whether there is a correlation between visual-motor development, as measured by the Bender Visual-Motor Gestalt Test (Bender test), and sexual maturity in adolescents, based on the Tanner Stages in Adolescents. 134 adolescents from 10 to 15 years of age participated in the study. The Bender test and the Raven's Progressive Matrices Test were employed. The measures were administered individually and information on sexual maturity and the presence of developmental disorders was collected from medical charts. The results of the Bender test were not affected by gender, age, schooling, or changes stemming from puberty, but were significantly affected by having repeated a school year and by developmental disorders. An association was found with Raven's scores. The Bender test proved sensitive to developmental disorders in adolescence. No association was found between visual-motor development and sexual maturity in adolescents.

  17. Defining Auditory-Visual Objects: Behavioral Tests and Physiological Mechanisms.

    Science.gov (United States)

    Bizley, Jennifer K; Maddox, Ross K; Lee, Adrian K C

    2016-02-01

    Crossmodal integration is a term applicable to many phenomena in which one sensory modality influences task performance or perception in another sensory modality. We distinguish the term binding as one that should be reserved specifically for the process that underpins perceptual object formation. To unambiguously differentiate binding form other types of integration, behavioral and neural studies must investigate perception of a feature orthogonal to the features that link the auditory and visual stimuli. We argue that supporting true perceptual binding (as opposed to other processes such as decision-making) is one role for cross-sensory influences in early sensory cortex. These early multisensory interactions may therefore form a physiological substrate for the bottom-up grouping of auditory and visual stimuli into auditory-visual (AV) objects. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Testing geoscience data visualization systems for geological mapping and training

    Science.gov (United States)

    Head, J. W.; Huffman, J. N.; Forsberg, A. S.; Hurwitz, D. M.; Basilevsky, A. T.; Ivanov, M. A.; Dickson, J. L.; Senthil Kumar, P.

    2008-09-01

    Traditional methods of planetary geological mapping have relied on photographic hard copy and light-table tracing and mapping. In the last several decades this has given way to the availability and analysis of multiple digital data sets, and programs and platforms that permit the viewing and manipulation of multiple annotated layers of relevant information. This has revolutionized the ability to incorporate important new data into the planetary mapping process at all scales. Information on these developments and approaches can be obtained at http://astrogeology.usgs. gov/ Technology/. The processes is aided by Geographic Information Systems (GIS) (see http://astrogeology. usgs.gov/Technology/) and excellent analysis packages (such as ArcGIS) that permit co-registration, rapid viewing, and analysis of multiple data sets on desktop displays (see http://astrogeology.usgs.gov/Projects/ webgis/). We are currently investigating new technological developments in computer visualization and analysis in order to assess their importance and utility in planetary geological analysis and mapping. Last year we reported on the range of technologies available and on our application of these to various problems in planetary mapping. In this contribution we focus on the application of these techniques and tools to Venus geological mapping at the 1:5M quadrangle scale. In our current Venus mapping projects we have utilized and tested the various platforms to understand their capabilities and assess their usefulness in defining units, establishing stratigraphic relationships, mapping structures, reaching consensus on interpretations and producing map products. We are specifically assessing how computer visualization display qualities (e.g., level of immersion, stereoscopic vs. monoscopic viewing, field of view, large vs. small display size, etc.) influence performance on scientific analysis and geological mapping. We have been exploring four different environments: 1) conventional

  19. Test-retest reliability of Eurofit Physical Fitness items for children with visual impairments

    NARCIS (Netherlands)

    Houwen, Suzanne; Visscher, Chris; Hartman, Esther; Lemmink, Koen A. P. M.

    The purpose of this study was to examine the test-retest reliability of physical fitness items from the European Test of Physical Fitness (Eurofit) for children with visual impairments. A sample of 21 children, ages 6-12 years, that were recruited from a special school for children with visual

  20. An Item Analysis and Validity Investigation of Bender Visual Motor Gestalt Test Score Items

    Science.gov (United States)

    Lambert, Nadine M.

    1971-01-01

    This investigation attempted to demonstrate the utility of standard item analysis procedures for selecting the most reliable and valid items for scoring Bender Visual Motor Gestalt Test test records. (Author)

  1. Astronauts Cooper and Conrad prepare cameras during visual acuity tests

    Science.gov (United States)

    1965-01-01

    Astronauts L. Gordon Cooper Jr. (left), command pilot, and Charles Conrad Jr., pilot, the prime crew of the Gemini 5 space flight, prepare their cameras while aboard a C-130 aircraft flying near Laredo. The two astronauts are taking part in a series of visual acuity experiments to aid them in learning to identify known terrestrial features under controlled conditions.

  2. Validity and Reliability of the Developmental Test of Visual Perception - Third Edition (DTVP-3).

    Science.gov (United States)

    Brown, Ted

    2016-07-01

    The Developmental Test of Visual Perception - Third Edition (DTVP-3) is a recently published revision of a visual perceptual test from the United States, frequently used by occupational therapists. It is important that tests have adequate documented reliability and validity and are evaluated in cross-cultural contexts. The purpose of the study was to assess the reliability and validity of the DTVP-3 when completed by a group of Australian participants. Thirty-nine typically developing children 6-8 years of age completed the DTVP-3 and the Developmental Test of Visual-Motor Integration - 6th edition (VMI-6). The internal consistency of the DVTP-3 was assessed using Cronbach alpha coefficients and the DTVP-3's convergent validity was examined by correlating it with the VMI-6 and its two supplementary tests. The five DTVP-3 subscales' Cronbach alpha coefficients ranged from.60 to.80 while its three composite indexes had coefficients all at the.80 level. The VMI-6 was significantly correlated with the DTVP-3 Figure Ground and Visual Closure subscales and the Motor-Reduced Visual Perception Index (MRVPI). The VMI-6 Visual Perception Supplementary Test was significantly correlated with the DTVP-3 Figure Ground, Visual Closure, Form Constancy, MRVPI, and General Visual Perception Index. The DTVP-3 exhibited acceptable levels of internal consistency and moderate levels of convergent validity with the VMI-6 when completed by a group of Australian children.

  3. [Polypropylene-polyester prostheses. Experimental studies].

    Science.gov (United States)

    Staniszewska, J

    1980-01-01

    Polypropylene-polyester prostheses invented by the Research and Development Center of the Textile Industry in łódź are composed of two knitted polyester layers with perpendicular columns arrangement laminated by polypropylene. The prostheses were implanted in 10 pigs into the sternum and shoulder blade, the abdominal wall and peritoneal cavity. The autopsies of the animals were made 90 to 180 days after the operation. Both in bone and soft tissues, the prostheses healed up without local or general complications. The results obtained in surgical post-operative, macroscopic and microscopic examinations prove that the polypropylene-polyester prostheses fulfill the basic conditions for biomaterials. The different moulders of these materials may be used as temporary or permanent implants.

  4. Safety and effectiveness considerations for clinical studies of visual prosthetic devices

    Science.gov (United States)

    Cohen, Ethan D.

    2007-03-01

    With the advent of new designs of visual prostheses for the blind, FDA is faced with developing guidance for evaluating their engineering, safety and patient performance. Visual prostheses are considered significant risk medical devices, and their use in human clinical trials must be approved by FDA under an investigation device exemption (IDE). This paper contains a series of test topics and design issues that sponsors should consider in order to assess the safety and efficacy of their device. The IDE application includes a series of pre-clinical and clinical data sections. The pre-clinical section documents laboratory, animal and bench top performance tests of visual prostheses safety and reliability to support a human clinical trial. The materials used in constructing the implant should be biocompatible, sterile, corrosion resistant, and able to withstand any forces exerted on it during normal patient use. The clinical data section is composed of items related to patient-related evaluation of device performance. This section documents the implantation procedure, trial design, statistical analysis and how visual performance is assessed. Similar to cochlear implants, a visual prosthesis is expected to last in the body for many years, and good pre-clinical and clinical testing will help ensure its safety, durability and effectiveness.

  5. Histological evaluation of novel ossicular chain replacement prostheses: an animal study in rabbits.

    Science.gov (United States)

    Turck, Christina; Brandes, Gudrun; Krueger, Ilka; Behrens, Peter; Mojallal, Hamidreza; Lenarz, Thomas; Stieve, Martin

    2007-08-01

    The improved biocompatibility of Bioverit II coated with a nanostructured surface shows promising qualities for use in human reconstructive middle ear surgery. In the case of chitosan-hydroxyapatite composite prostheses, further investigations regarding composition of the material, degree of purity and design are necessary before clinical application. The selection of optimal materials for reconstructive middle ear surgery continues to be a problem. In the present study novel materials were tested as total ossicular replacement prostheses (TORPs) in an animal model. Bioverit II coated with a nanostructured surface and chitosan-hydroxyapatite composites were placed in the middle ear of 40 rabbits. Uncoated Bioverit II was used as control. After an implantation period of 28, 84 or 300 days petrous bones were extracted, embedded in epoxy resin and examined by light microscopy. Uncoated and coated Bioverit prostheses revealed a mucosal coverage and a little osseogenic response after 28 days. The results of the coated Bioverit prostheses slightly surpassed those of the plain prostheses. Chitosan-hydroxyapatite composite prostheses were mostly found to be dislocated after 28 days. Formations of granulation tissue and fibrotic capsules were observed around these implants. This reaction could be caused by the instability of the composite material or may be due to impurities present in the chitosan.

  6. Biomechanical evaluation of two types of short-stemmed hip prostheses compared to the trust plate prosthesis by three-dimensional measurement of micromotions.

    Science.gov (United States)

    Fottner, Andreas; Schmid, Markus; Birkenmaier, Christof; Mazoochian, Farhad; Plitz, Wolfgang; Volkmar, Jansson

    2009-06-01

    Stemless and short-stemmed hip prostheses have been developed to preserve femoral bone stock. While all these prostheses claim a more or less physiological load transfer, clinical long-term results are only available for the stemless thrust plate prosthesis. In this study, the in vitro primary stability of the thrust plate prosthesis was compared to two types of short-stemmed prostheses. In addition to the well-established Mayo prosthesis, the modular Metha prosthesis was tested using cone adapters with 130 degrees and 140 degrees neck-shaft-angles. The prostheses were implanted in composite femurs and loaded dynamically (300-1700 N). Three-dimensional micromotions at the bone-prosthesis interface were measured. In addition, the three-dimensional deformations at the surface of the composite femur were measured to gain data on the strain distribution. For all tested prostheses, the micromotions did not exceed 150 microm, the critical value for osteointegration. The thrust plate prosthesis revealed similar motions as the short-stemmed prostheses. The short-stemmed prosthesis with the 130 degrees cone tended to have the highest micromotions of all tested short-stemmed prostheses. The thrust plate prosthesis revealed the lowest alteration of bone surface deformation after implantation. The comparably low micromotions of the thrust plate prosthesis and the short-stemmed prostheses should be conducive to osseous integration. The higher alteration of load transmission after implantation reveals a higher risk of stress shielding for the short-stemmed prostheses.

  7. Qualifying program on Non-Destructive Testing, Visual Inspection of the welding (level 2)

    International Nuclear Information System (INIS)

    Shafee, M. A.

    2011-01-01

    Nondestructive testing is a wide group of analysis technique used in science and industry to evaluate the properties of a material, component or system without causing damage. Common Non-Destructive Testing methods include ultrasonic, magnetic-particle, liquid penetrate, radiographic, visual inspection and eddy-current testing. AAEA put the new book of the Non-Destructive Testing publication series that focused on Q ualifying program on Non-Destructive Testing, visual inspection of welding-level 2 . This book was done in accordance with the Arab standard certification of Non-Destructive Testing (ARAB-NDT-CERT-002) which is agreeing with the ISO-9712 (2005) and IAEA- TEC-DOC-487. It includes twenty one chapters dealing with engineering materials used in industry, the mechanical behavior of metals, metal forming equipments, welding, metallurgy, testing of welds, introduction to Non-Destructive Testing, defects in metals, welding defects and discontinuities, introduction to visual inspection theory, properties and tools of visual testing, visual testing, quality control regulations, standards, codes and specifications, procedures of welding inspections, responsibility of welding test inspector, qualification of Non-Destructive Testing inspector and health safety during working.

  8. Method matters: systematic effects of testing procedure on visual working memory sensitivity.

    Science.gov (United States)

    Makovski, Tal; Watson, Leah M; Koutstaal, Wilma; Jiang, Yuhong V

    2010-11-01

    Visual working memory (WM) is traditionally considered a robust form of visual representation that survives changes in object motion, observer's position, and other visual transients. This article presents data that are inconsistent with the traditional view. We show that memory sensitivity is dramatically influenced by small variations in the testing procedure, supporting the idea that representations in visual WM are susceptible to interference from testing. In the study, participants were shown an array of colors to remember. After a short retention interval, memory for one of the items was tested with either a same-different task or a 2-alternative-forced-choice (2AFC) task. Memory sensitivity was much lower in the 2AFC task than in the same-different task. This difference was found regardless of encoding similarity or of whether visual WM required a fine or coarse memory resolution. The 2AFC disadvantage was reduced when participants were informed shortly before testing which item would be probed. The 2AFC disadvantage diminished in perceptual tasks and was not found in tasks probing visual long-term memory. These results support memory models that acknowledge the labile nature of visual WM and have implications for the format of visual WM and its assessment. (c) 2010 APA, all rights reserved

  9. Auditory and Visual Continuous Performance Tests: Relationships with Age, Gender, Cognitive Functioning, and Classroom Behavior

    Science.gov (United States)

    Lehman, Elyse Brauch; Olson, Vanessa A.; Aquilino, Sally A.; Hall, Laura C.

    2006-01-01

    Elementary school children in three grade groups (Grades K/1, 3, and 5/6) completed either the auditory or the visual 1/9 vigilance task from the Gordon Diagnostic System (GDS) as well as subtests from the Wechsler Intelligence Scale for Children--Third Edition and auditory or visual processing subtests from the Woodcock-Johnson Tests of Cognitive…

  10. Auditory and Visual Differences in Time Perception? An Investigation from a Developmental Perspective with Neuropsychological Tests

    Science.gov (United States)

    Zelanti, Pierre S.; Droit-Volet, Sylvie

    2012-01-01

    Adults and children (5- and 8-year-olds) performed a temporal bisection task with either auditory or visual signals and either a short (0.5-1.0s) or long (4.0-8.0s) duration range. Their working memory and attentional capacities were assessed by a series of neuropsychological tests administered in both the auditory and visual modalities. Results…

  11. [Measuring contrast sensitivity using visual acuity tests in retinal and optic nerve diseases].

    Science.gov (United States)

    Sommer, E; Marré, E; Mierdel, P

    1990-01-01

    The luminance contrast needed to discern various test types was measured with monochromatic and achromatic light to detect discrete functional deficiencies of the retina and optic nerve in cases of normal visual acuity. Landolt rings corresponding to visual acuity levels from 0.04 to 1.0 were used as test types. A significant increase in the necessary minimum contrast was detectable with blue test light on large Landolt rings in patients with diabetic retinopathy, ocular hypertension and glaucoma and with green or yellow test light on medium-sized and small Landolt rings in patients with central serous chorioidopathy and optic atrophy. The additional contrast needed to reach the maximum visual acuity amounts to 14-100% compared with normal visual acuity, depending on the color of the test light and the diagnosis. The amount of contrast needed is greatest in retinal diseases, and it is therefore possible to a certain extent to distinguish these from diseases of the optic nerve.

  12. Visualizing the impact of prevalence on a diagnostic test

    DEFF Research Database (Denmark)

    Rehling, Michael

    2010-01-01

    The purpose of a diagnostic test is to confirm or rule out disease or to increase or decrease the probability of disease. Only a few tests can separate all patients into those with and without a disease (true positive and true negative test). Usually there will be some false test results (false p....... This technical note brings a new illustration of the relative distribution of the four test results at prevalence from 0-1. The figure facilitates the understanding of the impact prevalence has on the predictive values of a clinical test.......The purpose of a diagnostic test is to confirm or rule out disease or to increase or decrease the probability of disease. Only a few tests can separate all patients into those with and without a disease (true positive and true negative test). Usually there will be some false test results (false...... positive and false negative). Traditionally, the four test results are given in a 2 by 2 table, and the terms sensitivity, specificity, and predictive values defined. The influence of the prevalence of the disease in question on the relative distribution of the four test results is not obvious...

  13. Usability Testing of a Large, Multidisciplinary Library Database: Basic Search and Visual Search

    Directory of Open Access Journals (Sweden)

    Jody Condit Fagan

    2006-09-01

    Full Text Available Visual search interfaces have been shown by researchers to assist users with information search and retrieval. Recently, several major library vendors have added visual search interfaces or functions to their products. For public service librarians, perhaps the most critical area of interest is the extent to which visual search interfaces and text-based search interfaces support research. This study presents the results of eight full-scale usability tests of both the EBSCOhost Basic Search and Visual Search in the context of a large liberal arts university.

  14. Quality of life assessment of implant-retained overdentures and fixed metal-acrylic resin prostheses in patients with marginal mandibulectomy.

    Science.gov (United States)

    Karayazgan-Saracoglu, Banu; Atay, Arzu; Korkmaz, Cumhur; Gunay, Yumushan

    2017-10-01

    Several factors affect the prosthetic outcome of patients with mandibular defects. However, it is questionable whether fixed or removable implant-supported prostheses meet the expectations and satisfaction of the patients. The perspectives of these patients are important in managing the prosthetic treatment strategies. The purpose of this prospective clinical study was to evaluate the satisfaction and oral health-related quality of life of patients with marginal mandibulectomies with implant-retained overdentures and fixed metal-acrylic resin prostheses. Twenty-two participants with marginal mandibulectomies were included in the study. They completed an oral health impact profile questionnaire designed for patients with edentulism (OHIP-Edent) for the assessment of quality of life and visual analog scales (VASs) to validate their general satisfaction before treatment. Ten participants received 4 implant-retained fixed metal-acrylic resin prostheses, whereas 12 participants were treated with 2 implant-supported overdentures. Six months after delivery of their prostheses, the participants completed the OHIP-Edent questionnaire and VAS again. For the statistical analyses, Student t tests together with descriptive statistics (mean, standard deviation, frequency) were used in the 2 intergroup parameter comparisons that showed normal distribution. The Mann-Whitney U test and Kruskal-Wallis test were used for intergroup comparisons, and the Wilcoxon signed rank test was used for intragroup comparisons. Compared with pretreatment mean values, a statistically significant (P<.05) decrease in mean scores of all OHIP-Edent values and an increase in VAS scores were found in both groups. After patients were treated, their OHIP-Edent values in the group with an overdenture prosthesis were higher than those in the group with a fixed metal-acrylic resin prosthesis (P<.05). These results demonstrate that implant-retained overdentures and fixed metal-acrylic resin prostheses provide

  15. Visual-motor and executive functions in children born preterm: the Bender Visual Motor Gestalt Test revisited.

    Science.gov (United States)

    Böhm, Birgitta; Lundequist, Aiko; Smedler, Ann-Charlotte

    2010-10-01

    Visual-motor development and executive functions were investigated with the Bender Test at age 5½ years in 175 children born preterm and 125 full-term controls, within the longitudinal Stockholm Neonatal Project. Assessment also included WPPSI-R and NEPSY neuropsychological battery for ages 4-7 (Korkman, 1990). Bender protocols were scored according to Brannigan & Decker (2003), Koppitz (1963) and a complementary neuropsychological scoring system (ABC), aimed at executive functions and developed for this study. Bender results by all three scoring systems were strongly related to overall cognitive level (Performance IQ), in both groups. The preterm group displayed inferior visual-motor skills compared to controls also when controlling for IQ. The largest group differences were found on the ABC scoring, which shared unique variance with NEPSY tests of executive function. Multiple regression analyses showed that hyperactive behavior and inattention increased the risk for visual-motor deficits in children born preterm, whereas no added risk was seen among hyperactive term children. Gender differences favoring girls were strongest within the preterm group, presumably reflecting the specific vulnerability of preterm boys. The results indicate that preterm children develop a different neurobehavioral organization from children born at term, and that the Bender test with a neuropsychological scoring is a useful tool in developmental screening around school start. © 2010 The Authors. Scandinavian Journal of Psychology © 2010 The Scandinavian Psychological Associations.

  16. Visual-Motor Test Performance: Race and Achievement Variables.

    Science.gov (United States)

    Fuller, Gerald B.; Friedrich, Douglas

    1979-01-01

    Rural Black and White children of variant academic achievement were tested on the Minnesota Percepto-Diagnostic Test, which consists of six gestalt designs for the subject to copy. Analyses resulted only in a significant achievement effect; when intellectual level was statistically controlled, race was not a significant variable. (Editor/SJL)

  17. Serpentine End Matching: A Test of Visual Perception

    Science.gov (United States)

    Bruce G. Hansen; Charles J. Gatchell

    1978-01-01

    In tests of gross perception of Serpentine end matched (Sem) joints in oak and cherry display panels, there were no significant differences between the number of times the non-Sem panels were chosen and the number of these selections that could be attributed to chance. Results of separate tests of sensitivity of perception of Sem joints showed that the most conspicuous...

  18. Visualization test facility of nuclear fuel rod emergency cooling system

    International Nuclear Information System (INIS)

    Candido, Marcos Antonio; Mesquita, Amir Zacarias; Rezende, Hugo Cesar; Santos, Andre Augusto Campagnole

    2013-01-01

    The nuclear reactors safety is determined according to their protection against the consequences that may result from postulated accidents. The Loss of Coolant Accident (LOCA) is one the most important design basis accidents (DBA). The failure may be due to rupture of the primary loop piping. Another accident postulated is due to lack of power in the pump motors in the primary circuit. In both cases the reactor shut down automatically due to the decrease of reactivity to maintain the fissions, and to the drop of control rods. In the event of an accident it is necessary to maintain the coolant flow to remove the fuel elements residual heat, which remains after shut down. This heat is a significant amount of the maximum thermal power generated in normal operation (about 7%). Recently this event has been quite prominent in the press due to the reactor accident in Fukushima nuclear power station. This paper presents the experimental facility under rebuilding at the Thermal Hydraulic Laboratory of the Nuclear Technology Development Center (CDTN) that has the objective of monitoring and visualization of the process of emergency cooling of a nuclear fuel rod simulator, heated by Joule effect. The system will help the comprehension of the heat transfer process during reflooding after a loss of coolant accident in the fuel of light water reactor core. (author)

  19. Standardized Ability Testing for Vocational Rehabilitation in Visually Impaired Adults: A Literature Review.

    Science.gov (United States)

    Reid, J. M. V.

    1997-01-01

    Reviews research on ability testing for adults with visual impairments, especially the tests used for vocational assessment and counseling. The verbal scales of the Wechsler Adult Intelligence Scale-Revised were found to be widely accepted. The problems, however, with relying solely on verbal assessment are addressed, and the need for tests for…

  20. Developing a Vocabulary Size Test Measuring Two Aspects of Receptive Vocabulary Knowledge: Visual versus Aural

    Science.gov (United States)

    Aizawa, Kazumi; Iso, Tatsuo; Nadasdy, Paul

    2017-01-01

    Testing learners' English proficiency is central to university English classes in Japan. This study developed and implemented a set of parallel online receptive aural and visual vocabulary tests that would predict learners' English proficiency. The tests shared the same target words and choices--the main difference was the presentation of the…

  1. Gifted Children and Visual-Motor Development: A Comparison of Bender-Gestalt and VMI Test Performance.

    Science.gov (United States)

    Knoff, Howard M.; Sperling, Barbara L.

    1986-01-01

    A sample of 63 gifted elementary-school students was administered the Bender Visual-Motor Gestalt Test and the Developmental Test of Visual-Motor Integration. Group results revealed no significant differences between the two tests, that they did correlate significantly, and that younger students had advanced visual-motor development when tested…

  2. Discrimination of tenants with a visual impairment on the housing market: Empirical evidence from correspondence tests.

    Science.gov (United States)

    Verhaeghe, Pieter-Paul; Van der Bracht, Koen; Van de Putte, Bart

    2016-04-01

    According to the social model of disability, physical 'impairments' become disabilities through exclusion in social relations. An obvious form of social exclusion might be discrimination, for instance on the rental housing market. Although discrimination has detrimental health effects, very few studies have examined discrimination of people with a visual impairment. We aim to study (1) the extent of discrimination of individuals with a visual impairment on the rental housing market and (2) differences in rates of discrimination between landowners and real estate agents. We conducted correspondence tests among 268 properties on the Belgian rental housing market. Using matched tests, we compared reactions by realtors and landowners to tenants with and tenants without a visual impairment. The results show that individuals with a visual impairment are substantially discriminated against in the rental housing market: at least one in three lessors discriminate against individuals with a visual impairment. We further discern differences in the propensity toward discrimination according to the type of lessor. Private landlords are at least twice as likely to discriminate against tenants with a visual impairment than real estate agents. At the same time, realtors still discriminate against one in five tenants with a visual impairment. This study shows the substantial discrimination against visually people with an impairment. Given the important consequences discrimination might have for physical and mental health, further research into this topic is needed. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. The Effects of Dynamic Assessment Procedures on Raven Matrices Performance, Visual Search Behavior, Test Anxiety and Test Orientation.

    Science.gov (United States)

    Bethge, Hans-Jorg; And Others

    1982-01-01

    Dynamic assessment procedures involving either verbalization or elaborated feedback lead to higher levels of Ravens Matrices performance, modified visual search behaviors, reduced test anxiety, and reduced negative orientations to the testing situation in third graders. Results are interpreted on offering construct validation to the assessment…

  4. Race Differences on the Developmental Test of Visual Motor Integration, the Slosson Intelligence Test, and the ABC Inventory.

    Science.gov (United States)

    Schooler, Douglas L.; Anderson, Robert L.

    1979-01-01

    Analyzes preschoolers' scores on the Developmental Test of Visual Motor Integration (VMI), the Slosson Intelligence Test (SIT), and the ABC Inventory (ABCI). Separate ANOVAs reveal no race effect on the VMI. Race differences favoring Whites are found for SIT and ABCI. There were no effects for sex on any measure. (Author)

  5. Visualization of elongation measurements using an SER universal testing platform

    Czech Academy of Sciences Publication Activity Database

    Pivokonský, Radek; Filip, Petr; Zelenková, Jana

    2015-01-01

    Roč. 25, č. 1 (2015), s. 1-8 ISSN 1430-6395 R&D Projects: GA ČR(CZ) GAP105/11/2342 Institutional support: RVO:67985874 Keywords : elongational viscosity * Universal Testing Platform (SER) * polymer melts * LDPE Subject RIV: BK - Fluid Dynamics Impact factor: 1.241, year: 2015

  6. Postoperative changes in visual evoked potentials and cognitive function tests following sevoflurane anaesthesia.

    LENUS (Irish Health Repository)

    Iohom, G

    2012-02-03

    We tested the hypothesis that minor disturbance of the visual pathway persists following general anaesthesia even when clinical discharge criteria are met. To test this, we measured visual evoked potentials (VEPs) in 13 ASA I or II patients who did not receive any pre-anaesthetic medication and underwent sevoflurane anaesthesia. VEPs were recorded on four occasions, before anaesthesia and at 30, 60, and 90 min after emergence from anaesthesia. Patients completed visual analogue scales (VAS) for sedation and anxiety, a Trieger Dot Test (TDT) and a Digit Symbol Substitution Test (DSST) immediately before each VEP recording. These results were compared using Student\\'s t-test. P<0.05 was considered significant. VEP latency was prolonged (P<0.001) and amplitude diminished (P<0.05) at 30, 60, and 90 min after emergence from anaesthesia, when VAS scores for sedation and anxiety, TDT, and DSST had returned to pre-anaesthetic levels.

  7. Rapid Visual Tests: Fast and Reliable Detection of Ochratoxin A

    Directory of Open Access Journals (Sweden)

    Miguel Lopez-Ferber

    2010-08-01

    Full Text Available This paper reviews the early detection strategies that have been employed for the rapid monitoring of ochratoxin A (OTA contamination of food. OTA, a mycotoxin mainly produced by some Aspergillus and Penicillium species, is found in cereals, coffee, wine, pork and grapes. To minimize the entry of this mycotoxin into the food chain, rapid diagnostic tools are required. To this end, the potential use of lateral flow devices has also been developed. In this study, we analyze the robustness of test strips using published methods for colorimetric detection. Different test formats are discussed, and challenges in the development of lateral flow devices for on-site determination of OTA, with requirements such as robustness, speed, and cost-effectiveness, are discussed.

  8. IMPROVED HEALING OF SMALL-CALIBER POLYTETRAFLUOROETHYLENE PROSTHESES BY INDUCTION OF A CLOT LAYER - A REVIEW OF EXPERIMENTAL STUDIES IN RATS

    NARCIS (Netherlands)

    VANDERLEI, B; STRONCK, JW; WILDEVUUR, CRH

    1991-01-01

    This report reviews our experiments that have been undertaken to test the hypothesis whether the induction of a clot layer on the graft surface of small-caliber polytetrafluoroethylene ( PTFE) prostheses might improve their healing. 1 2 PTFE prostheses with a fibril length of 30-mu-m, PTFE

  9. [Modern types and usage of testicular prostheses].

    Science.gov (United States)

    Zieliński, Tomasz

    2010-10-01

    Agenesia or hypoplasia of testicle create not only physiological complications but also aesthetic and psychological problems. They can be effectively solved by implantation of testicular implants. Implantation of testicular prostheses was initiated in 40ies of XX century, and for years there has been search for the best material for their production. In the present paper we compared currently used testicles prostheses and controversies related to their usage. We discussed indications for the procedure and technical aspects. Particular attention was paid on complications of the procedure, methods to prevent them, and results of the treatment.

  10. Predicting Second Grade Achievement Scores with the Slosson Intelligence Test, Peabody Picture Vocabulary Test, Goodenough-Harris Drawing Test, Developmental Test of Visual Motor and the Metropolitan Readiness Test.

    Science.gov (United States)

    Flynn, Timothy M.

    The predictive validity of the Slosson Intelligence Test, Peabody Picture Vocabulary Test, Goodenough-Harris Drawing Test, Developmental Test of Visual Motor Integration, and the Metropolitan Readiness Test was evaluated for use with kindergarten children. The criterion measure was the California Achievement Tests administered when the children…

  11. Picture span test: measuring visual working memory capacity involved in remembering and comprehension.

    Science.gov (United States)

    Tanabe, Azumi; Osaka, Naoyuki

    2009-05-01

    The working memory system is assumed to operate with domain-specific (verbal and visuospatial) resources that support cognitive activities. However, in research on visuospatial working memory, an appropriate visual working memory task has not been established. For the present study, a novel task was developed: the picture span test (PST). This test requires memorizing parts of scene images while comprehending various scene situations simultaneously. Results of correlation analyses and a factor analysis among college students (n = 52) validated that PST can predict visuospatial cognitive skills whereas a simple visual storage task and a verbal working memory task cannot. Furthermore, an error analysis indicated that inhibition is important for visuospatial working memory. Additionally, PST is considered to reflect individual differences in the visual working memory capacity. These findings suggest that the PST is appropriate for measuring visual working memory capacity and can elucidate its relationship to higher cognition.

  12. The Handy Eye Check: a mobile medical application to test visual acuity in children.

    Science.gov (United States)

    Toner, Keri N; Lynn, Michael J; Candy, T Rowan; Hutchinson, Amy K

    2014-06-01

    To compare visual acuity results obtained with the Handy Eye Chart to results obtained using the Handy Eye Check, a mobile medical application that electronically presents isolated Handy Eye Chart optotypes according the Amblyopia Treatment Study (ATS) protocol. Consecutive patients 6-18 years of age presenting for eye examinations between May 30, 2012, and June 26, 2012, were invited to participate. Monocular visual acuity testing was performed on the subject's poorer-seeing eye using both the Handy Eye Check and the Handy Eye Chart under the same conditions. Visual acuity was first tested using the mobile application, then using the chart, followed by repeated application testing. Patients were excluded if they were unable to undergo the required visual acuity testing or if visual acuity in the worse-seeing eye was less than 20/200 (for validity testing, but not reliability testing). There was a strong linear correlation (r = 0.92) and a mean difference in acuity of -0.005 logMAR, or less than one letter (95% CI, -0.03 to 0.02), between the two tests. The 95% limits of agreement were ± 2 lines. Test-retest reliability was high, with 81% of retest scores within 0.1 logMAR (5 letters) and 100% within 0.2 logMAR (10 letters), an intraclass correlation coefficient of 0.93, and a standard error of measurement of 0.08. The Handy Eye Check mobile application compares similarly to the Handy Eye Chart as a valid and reliable test of visual acuity in children age 6-18 years. Published by Mosby, Inc.

  13. Neuropsychological assessment with the Visual Gestalt Test: psychometric properties and differential diagnostic probabilities.

    Science.gov (United States)

    la Cour, Peter; Andersen, Ruth

    2006-02-01

    The Visual Gestalt Test is a neuropsychological instrument developed for evaluation of learning and memory of visuo-spatial material. A revised strategy of scoring has motivated the present study, where data from 153 normal persons, 99 epilepsy patients, and 24 depressed patients are presented and compared. The Visual Gestalt Test is observed to discriminate between normal and diagnosed groups in several ways. Additionally it is found to discriminate between depressed and brain damage subgroups of patients. Data are presented in order to supplement previously published ways of scoring and norms. Practical guidelines for the clinical applications of the test are suggested as perspectives.

  14. Remote visual testing (RVT) for the diagnostic inspection of feedwater heaters

    International Nuclear Information System (INIS)

    Nugent, M.J.; Pellegrino, B.A.

    1991-01-01

    In this paper the benefits and limitations of Non-Destructive Testing (NDT) on feedwater heaters will be briefly reviewed. All Remote Visual Testing (RVT) devices including borescopes, fiberscopes, videoborescopes and Closed Circuit Television (CCTV) cameras will be discussed along with currently accepted formats for documentation. The benefits of a comprehensive in-place inspection involving Remote Visual Testing will be discussed in relationship to its diagnostic capabilities. The results of eight post-service heater inspections will be discussed along with the root cause of failure of seven unique failure mechanisms. These inspections, including FWH access, RVT tool and data analysis, will be detailed

  15. [COMBINED ACRYLIC-POLYPROPYLEN REMOVABLE PROSTHESES FOR PROSTHODONTIC TREATMENT].

    Science.gov (United States)

    Shuturminsky, V

    2015-10-01

    The article deals with the development of methods to prevent complications with prosthetic dentures patients with psychiatric status. The authors developed a method of manufacturing the denture using modern thermoplastic materials, the use of which in practice does not cause prosthetic stomatitis in patients with psychiatric status. The proposed methodology has been tested clinically. Based on Schiller- Pisarev and study fixation of prostheses has been shown the advantage of the prosthesis used for prosthetics partial dentition defects that can not be fixed prosthetics in this category of patients.

  16. Modular externally-powered system for limb prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Seamone, W.; Hoshall, C.H.; Schmeisser, G.

    Many upper limb amputees especially those who have sustained high level amputations of injury to remaining portions of the body, are unable to use conventional prosthetic devices effectively. In an effort to help the more severely handicapped amputees and those who may for other reasons require capabilities that standard prostheses cannot provide, the Applied Physics Laboratory, in conjunction with the Johns Hopkins Medical Institutions, has developed a prosthetic system which is powered by rechargeable batteries. The amputee need supply only a control signal. This article describes the concept which is now being evaluated with the aid of amputee subjects, and discusses results obtained to data in field tests.

  17. Comparing the Effects of Elementary Music and Visual Arts Lessons on Standardized Mathematics Test Scores

    Science.gov (United States)

    King, Molly Elizabeth

    2016-01-01

    The purpose of this quantitative, causal-comparative study was to compare the effect elementary music and visual arts lessons had on third through sixth grade standardized mathematics test scores. Inferential statistics were used to compare the differences between test scores of students who took in-school, elementary, music instruction during the…

  18. A Note on Some Problems in the Testing of Personality Characteristics in Children with Visual Impairment

    Science.gov (United States)

    Tobin, Michael; Hill, Eileen

    2010-01-01

    An examination is made of the value of using published personality tests with young blind and partially sighted children. Based on data gathered during a longitudinal investigation into the educational and psychological development of a group of 120 visually impaired learners, the authors conclude that their own selection of a test instrument…

  19. Comparison of the Bender-Gestalt and Revised Developmental Test of Visual-Motor Integration.

    Science.gov (United States)

    Armstrong, Barbara B.; Knopf, Karen F.

    1982-01-01

    Using children with learning disabilities and children enrolled in regular classrooms, test scores on the Bender-Gestalt and the Developmental Test of Visual-Motor Integration indicated high and significant correlations for the learning-disabled group and low but significant correlations for regular students. A nine-month mean difference in scores…

  20. Visual association test to detect early dementia of the Alzheimer type

    NARCIS (Netherlands)

    Lindeboom, J.; Schmand, B.; Tulner, L.; Walstra, G.; Jonker, C.

    2002-01-01

    Background: The visual association test (VAT) is a brief learning task based on imagery mnemonics. The test materials consist of six line drawings of pairs of interacting objects or animals-for example, an ape holding an umbrella. The person is asked to name each object and, later, is presented with

  1. The DiaNAH test battery for visual perceptual disorders : Validity and efficacy in rehabilitation practice

    NARCIS (Netherlands)

    Heutink, Jochem; de Vries, Stefanie; Melis, Bart; Vrijling, Anne; Tucha, Oliver

    2018-01-01

    We developed the DiaNAH test battery for the screening of mid-level and higher-order visual perceptual disorders in clinical practice. The DiaNAH battery comprises 11 different tests and can be administered in 30-60 minutes. Important feature of the DiaNAH battery is that it is administered on a 24”

  2. Reliability and validity of the rey visual design learning test in primary school children

    NARCIS (Netherlands)

    Wilhelm, P.

    2004-01-01

    The Rey Visual Design Learning Test (Rey, 1964, in Spreen & Strauss, 1991) assesses immediate memory span, new learning and recognition for non-verbal material. Three studies are presented that focused on the reliability and validity of the RVDLT in primary school children. Test-retest reliability

  3. 'I didn't see that coming': simulated visual fields and driving hazard perception test performance.

    Science.gov (United States)

    Glen, Fiona C; Smith, Nicholas D; Jones, Lee; Crabb, David P

    2016-09-01

    Evidence is limited regarding specific types of visual field loss associated with unsafe driving. We use novel gaze-contingent software to examine the effect of simulated visual field loss on computer-based driving hazard detection with the specific aim of testing the impact of scotomata located to the right and left of fixation. The 'hazard perception test' is a component of the UK driving licence examination, which measures speed of detecting 15 different hazards in a series of real-life driving films. We have developed a novel eye-tracking and computer set up capable of generating a realistic gaze-contingent scotoma simulation (GazeSS) overlaid on film content. Thirty drivers with healthy vision completed three versions of the hazard perception test in a repeated measures experiment. In two versions, GazeSS simulated a scotoma in the binocular field of view to the left or right of fixation. A third version was unmodified to establish baseline performance. Participants' mean baseline hazard perception test score was 51 ± 7 (out of 75). This reduced to 46 ± 9 and 46 ± 11 when completing the task with a binocular visual field defect located to the left and right of fixation, respectively. While the main effect of simulated visual field loss on performance was statistically significant (p = 0.007), there were no average differences in the experimental conditions where a scotoma was located in the binocular visual field to the right or left of fixation. Simulated visual field loss impairs driving hazard detection on a computer-based test. There was no statistically significant difference in average performance when the simulated scotoma was located to the right or left of fixation of the binocular visual field, but certain types of hazard caused more difficulties than others. © 2016 Optometry Australia.

  4. Consistent phosphenes generated by electrical microstimulation of the visual thalamus. An experimental approach for thalamic visual neuroprostheses

    Directory of Open Access Journals (Sweden)

    Fivos ePanetsos

    2011-07-01

    Full Text Available Most work on visual prostheses has centred on developing retinal or cortical devices. However, when retinal implants are not feasible, neuroprostheses could be implanted in the lateral geniculate nucleus of the thalamus (LGN, the intermediate relay station of visual information from the retina to the visual cortex (V1. The objective of the present study was to determine the types of artificial stimuli that when delivered to the visual thalamus can generate reliable responses of the cortical neurons similar to those obtained when the eye perceives a visual image. Visual stimuli {Si} were presented to one eye of an experimental animal and both, the thalamic {RThi} and cortical responses {RV1i} to such stimuli were recorded. Electrical patterns {RThi*} resembling {RThi} were then injected into the visual thalamus to obtain cortical responses {RV1i*} similar to {RV1i}. Visually- and electrically-generated V1 responses were compared.Results: During the course of this work we: (i characterised the response of V1 neurons to visual stimuli according to response magnitude, duration, spiking rate and the distribution of interspike intervals; (ii experimentally tested the dependence of V1 responses on stimulation parameters such as intensity, frequency, duration, etc. and determined the ranges of these parameters generating the desired cortical activity; (iii identified similarities between responses of V1 useful to compare the naturally and artificially generated neuronal activity of V1; and (iv by modifying the stimulation parameters, we generated artificial V1 responses similar to those elicited by visual stimuli.Generation of predictable and consistent phosphenes by means of artificial stimulation of the LGN is important for the feasibility of visual prostheses. Here we proved that electrical stimuli to the LGN can generate V1 neural responses that resemble those elicited by natural visual stimuli.

  5. ["Bionic" arm prostheses. State of the art in research and development].

    Science.gov (United States)

    Pylatiuk, C; Döderlein, L

    2006-11-01

    A new generation of arm prostheses is being developed worldwide. These so-called bionic prostheses are intended to offer additional functions, such as sensory feedback, extended range of possible movement, intuitive movement control as far as possible, and a more natural cosmetic appearance. In recent years, prosthetic components with much enhanced performance have been developed for use at various levels of the upper limb. Artificial hands that allow for additional grips are are being tested in clinical settings. Innovative methods of signal acquisition and communication with the patient are being intensively researched. Several patients have been provided with prototypes of new arm prostheses. At the moment, the results are limited by the restricted communication between patient and prosthesis. However, we can expect the options for prosthesis control to be extended in the near future.

  6. A new test of visual acuity using a holographic phase grating and a laser.

    Science.gov (United States)

    Smith, T W; Remijan, P W; Remijan, W; Kolder, H E; Snyder, J

    1979-04-01

    A new visual acuity testing device is able to determine a specific visual acuity of the retina even in the presence of opacities of the ocular media, such as a cataract. This is achieved by forming two spatially coherent, quasimonochromatic point sources near the nodal point of the eye. The two spherical waves that emanate from the point sources interact to produce a pattern of stripes on the retina. The intensity of the pattern is easily varied. More importantly, the pattern can be projected over different-sized retinal areas corresponding to visual fields of 0.5 to 15 degrees in diameter. The device may be useful for vision research and preoperative assessments of visual potential.

  7. Monte Carlo dose calculations for phantoms with hip prostheses

    International Nuclear Information System (INIS)

    Bazalova, M; Verhaegen, F; Coolens, C; Childs, P; Cury, F; Beaulieu, L

    2008-01-01

    Computed tomography (CT) images of patients with hip prostheses are severely degraded by metal streaking artefacts. The low image quality makes organ contouring more difficult and can result in large dose calculation errors when Monte Carlo (MC) techniques are used. In this work, the extent of streaking artefacts produced by three common hip prosthesis materials (Ti-alloy, stainless steel, and Co-Cr-Mo alloy) was studied. The prostheses were tested in a hypothetical prostate treatment with five 18 MV photon beams. The dose distributions for unilateral and bilateral prosthesis phantoms were calculated with the EGSnrc/DOSXYZnrc MC code. This was done in three phantom geometries: in the exact geometry, in the original CT geometry, and in an artefact-corrected geometry. The artefact-corrected geometry was created using a modified filtered back-projection correction technique. It was found that unilateral prosthesis phantoms do not show large dose calculation errors, as long as the beams miss the artefact-affected volume. This is possible to achieve in the case of unilateral prosthesis phantoms (except for the Co-Cr-Mo prosthesis which gives a 3% error) but not in the case of bilateral prosthesis phantoms. The largest dose discrepancies were obtained for the bilateral Co-Cr-Mo hip prosthesis phantom, up to 11% in some voxels within the prostate. The artefact correction algorithm worked well for all phantoms and resulted in dose calculation errors below 2%. In conclusion, a MC treatment plan should include an artefact correction algorithm when treating patients with hip prostheses

  8. Residual Stresses in Porcelain-veneered Zirconia Prostheses

    Science.gov (United States)

    Baldassarri, Marta; Stappert, Christian F. J.; Wolff, Mark S.; Thompson, Van P.; Zhang, Yu

    2012-01-01

    Objectives Compressive stress has been intentionally introduced into the overlay porcelain of zirconia-ceramic prostheses to prevent veneer fracture. However, recent theoretical analysis has predicted that the residual stresses in the porcelain may be also tensile in nature. This study aims to determine the type and magnitude of the residual stresses in the porcelain veneers of full-contour fixed-dental prostheses (FDPs) with an anatomic zirconia coping design and in control porcelain with the zirconia removed using a well-established Vickers indentation method. Methods Six 3-unit zirconia FDPs were manufactured (NobelBiocare, Gothenburg, Sweden). Porcelain was hand-veneered using a slow cooling rate. Each FDP was sectioned parallel to the occlusal plane for Vickers indentations (n = 143; load = 9.8 N; dwell time = 5 s). Tests were performed in the veneer of porcelain-zirconia specimens (bilayers, n = 4) and porcelain specimens without zirconia cores (monolayers, n = 2). Results The average crack lengths and standard deviation, in the transverse and radial directions (i.e. parallel and perpendicular to the veneer/core interface, respectively), were 67 ± 12 μm and 52 ± 8 μm for the bilayers and 64 ± 8 μm and 64 ± 7 μm for the monolayers. These results indicated a major hoop compressive stress (~40 to 50 MPa) and a moderate radial tensile stress (~10 MPa) in the bulk of the porcelain veneer. Significance Vickers indentation is a powerful method to determine the residual stresses in veneered zirconia systems. Our findings revealed the presence of a radial tensile stress in the overlay porcelain, which may contributed to the large clinical chip fractures observed in these prostheses. PMID:22578663

  9. [Results of the Benton Visual Retention Test and the Bender Visual--Motor Gestalt Test among patients suffer from depressive disorders and organic depressive disorders].

    Science.gov (United States)

    Talarowska, Monika; Florkowski, Antoni; Zboralski, Krzysztof; Gałecki, Piotr

    2011-01-01

    The comorbidity of depression and dementia has been extensively studied. Four main hypotheses have been suggested to explain the relationship between depression and dementia: 1. depression may be a psychological reaction to perceived cognitive decline, 2. depression may be an early symptom of dementia, 3. depression may be an etiologic risk factor for the onset of dementia, and 4. dementia and depression share common risk factors. The objective of this study was to examine the differences between depressive disorders and organic depressive disorders by using two neuropsychological tests. A sample of 61 persons aged 23-62 years participated in the study. Patients who took part in the investigation were divided into two groups: depressive disorders (DD, n = 30), organic depressive disorders (ODD, n = 31). Cognitive functions were evaluated by the Benton Visual Retention Test (BVRT) and Bender Visual-Motor Gestalt Test (BVMGT). Relevant statistical differences among examined group were observed: in BVRT correct answers (p = 0.006), errors (p psychological test than ODD patients. DD group (average) in BVRT: correct answers (-1.33), errors (2.31); BVMGT (average): (50.37). ODD group (average) in BVRT: correct answers (-2.71), errors (5.81); BVMGT (average): (72.01). Patients with organic depressive disorders achieved significantly lower results than patients with depressive disorders in BVRT and BVMGT.

  10. Normatização de um teste computadorizado de atenção visual: (TAVIS Normatization of a computerized visual attention test (TAVIS

    Directory of Open Access Journals (Sweden)

    Mônica Duchesne

    1997-01-01

    Full Text Available Os autores apresentam os dados normativos de um teste computadorizado de atenção visual (TAVIS para crianças e adolescentes, que representa o primeiro instrumento neuropsicológico deste tipo projetado e desenvolvido no Brasil. Três tarefas diferentes avaliam os apectos de seletividade, alternância e sustentação da atenção. Erros de omissão e ação, bem como o tempo de reação, são avaliados. São comentadas as vantagens e limitações do teste.The authors present the normative data of a computerized test (TAVIS that address visual attention in children and adolescents being the first neuropsychological instrument as such devised and developed in Brazil. Selective, alternate and sustained attention aspects are evaluated through three different tasks. Omission and action errors as well as time reaction are evaluated. The advantages and limitations of the test are commented.

  11. Objective clinical assessment of change in swallowing ability of maxillectomy patients when wearing obturator prostheses.

    Science.gov (United States)

    Matsuyama, Miwa; Tsukiyama, Yoshihiro; Koyano, Kiyoshi

    2005-01-01

    Evaluation of treatment outcome is important in maxillofacial rehabilitation. Although eating is one of the oral functions that most strongly influences patients' quality of life, only a few reports exist on the objective assessment of swallowing for maxillectomy patients. The purpose of this study was to identify changes in the swallowing ability of maxillectomy patients when wearing obturator prostheses through the use of an objective clinical assessment. The swallowing ability of 38 postmaxillectomy patients consecutively treated with obturator prostheses was objectively evaluated with the "water-drinking test" that was developed for the assessment of dysphagia patients after cerebrovascular disease. In this test, the subjects were instructed to drink 30 mL of water in one swallow. The profile was evaluated with the combination of the time required for drinking the water and the incidence of cough reflex. Statistical analysis was performed using the Wilcoxon signed-rank test, the paired t test, and the Chi-square test with StatView 5.0 for the Macintosh. Performance improved significantly when the patients wore prostheses (P = .0026, Wilcoxon signed-rank test). The mean drinking times without and with prostheses were 8.2 +/- 6.3 s and 5.0 +/- 3.5 s, respectively. Drinking time was shortened significantly when the prosthesis was worn (P = .0002, paired t test). The assessment of behavior and episodes revealed that the swallowing ability of the maxillectomy patients was significantly improved when a prosthesis was worn (P = .0002, Chi-square test). The swallowing ability of maxillectomy patients was quantitatively and qualitatively improved with obturator prostheses.

  12. Perspectives of optic nerve prostheses.

    Science.gov (United States)

    Lane, Frank John; Nitsch, Kristian; Huyck, Margaret; Troyk, Philip; Schug, Ken

    2016-01-01

    A number of projects exist that are investigating the ability to restore visual percepts for individuals who are blind through a visual prosthesis. While many projects have reported the results from a technical basis, very little exists in the professional literature on the human experience of visual implant technology. The current study uses an ethnographic methodological approach to document the experiences of the research participants and study personnel of a optic nerve vision prosthesis project in Brussels, Belgium. The findings have implications for motivation for participating in clinical trials, ethical safeguards of participants and the role of the participant in a research study. Implications for Rehabilitation Rehabilitation practitioners are often solicited by prospective participants to assist in evaluating a clinical trial before making a decision about participation. Rehabilitation professionals should be aware that: The decision to participate in a clinical trial is ultimately up to the individual participant. However, participants should be aware that family members might experience stress from of a lack of knowledge about the research study. The more opportunities a participant has to share thoughts and feelings about the research study with investigators will likely result in a positive overall experience. Ethical safeguards put in place to protect the interests of an individual participant may have the opposite effect and create stress. Rehabilitation professionals can play an important role as participant advocates from recruitment through termination of the research study. Participant hope is an important component of participation in a research study. Information provided to participants by investigators during the consent process should be balanced carefully with potential benefits, so it does not destroy a participant's hope.

  13. A new dynamic visual acuity test to assess peripheral vestibular function.

    Science.gov (United States)

    Vital, Domenic; Hegemann, Stefan C A; Straumann, Dominik; Bergamin, Oliver; Bockisch, Christopher J; Angehrn, Dominik; Schmitt, Kai-Uwe; Probst, Rudolf

    2010-07-01

    To evaluate a novel test for dynamic visual acuity (DVA) that uses an adaptive algorithm for changing the size of Landolt rings presented during active or passive head impulses, and to compare the results with search-coil head impulse testing. Prospective study in healthy individuals and patients with peripheral vestibular deficits. Tertiary academic center. One hundred neuro-otologically healthy individuals (age range, 19-80 years) and 15 patients with bilateral (n = 5) or unilateral (n = 10) peripheral vestibular loss (age range, 27-72 years). Testing of static visual acuity (SVA), DVA during active and passive horizontal head rotations (optotype presentation at head velocities >100 degrees/s and >150 degrees/s), and quantitative horizontal head impulse testing with scleral search coils. Difference between SVA and DVA, that is, visual acuity loss (VA loss), gain of the high-acceleration vestibulo-ocular reflex. Passive head impulses and higher velocities were more effective than active impulses and lower velocities. Using passive head impulses and velocities higher than 150 degrees/s, the DVA test discriminated significantly (P test sensitivity was 100%, specificity was 94%, and accuracy was 95%, with search-coil head impulse testing used as a reference. In healthy individuals, VA loss increased significantly with age (P testing with Landolt rings that are adaptively changed in size enables detection of peripheral vestibular dysfunction in a fast and simple way.

  14. Testing the educational potential of 3D visualization software in oral radiographic interpretation.

    Science.gov (United States)

    Vuchkova, Julijana; Maybury, Terrence S; Farah, Camile S

    2011-11-01

    There is heightened optimism about the potential of 3D visualization software as an alternative learning resource in radiology education. The purpose of this study was to investigate the effect of 3D visualization software on students' learning of oral radiographic interpretation from 2D radiographic images. Fourth-year dental students underwent a learning intervention phase of radiographic interpretation of oral pathoses using 3D visualization software. The success of the educational intervention was assessed by quantitative means, using a radiographic interpretation test, and by qualitative means, using a structured Likert-scale survey, asking students to evaluate their own learning outcomes. It was anticipated that training with the rotational mode of 3D visualization software would provide additional depth cues, enabling students to create spatial-mental models of anatomy that they can apply to 2D radiographic interpretation of oral pathoses. Although quantitative assessment did not support this, questionnaire evaluations demonstrated a positive effect of the 3D visualization software by enhancing students' learning about radiographic interpretation. Despite much optimism about the educational potential of 3D visualization software, it is important to understand the interactions between learners and such new technologies in order to identify potential advantages and limitations prior to embracing them as learning resources.

  15. Testing the validity of wireless EEG for cognitive research with auditory and visual paradigms

    DEFF Research Database (Denmark)

    Weed, Ethan; Kratschmer, Alexandra Regina; Pedersen, Michael Nygaard

    and smaller cognitive components. To test the feasibility of these headsets for cognitive research, we compared performance of the Emotiv Epoc wireless headset (EM) with Brain Products ActiCAP (BP) active electrodes on two well-studied components: the auditory mismatch negativity (MMN) and the visual face...

  16. The Bender Visual Motor Gestalt Test: Implications for the Diagnosis and Prediction of Reading Achievement.

    Science.gov (United States)

    Lesiak, Judi

    1984-01-01

    Reviews 32 studies about the utility of the Bender Visual-Motor Gestalt Test (BG) as a predictor of reading, its relationship to reading achievement, and ability to differentiate between good and poor readers. Results question the use of the BG (scored using discrete error systems) in a diagnostic reading battery. (BH)

  17. Distal cantilever in full-arch prostheses and immediate loading: a retrospective clinical study.

    Science.gov (United States)

    Romanos, Georgios E; Gupta, Bhumija; Gaertner, Kathrin; Nentwig, Georg-Hubertus

    2014-01-01

    The purpose of this study was to analyze and evaluate the clinical success of distal cantilevers of fixed full-arch prostheses for the rehabilitation of edentulous arches in conjunction with immediate loading. Twenty-seven patients (15 men and 12 women) with a mean age of 59 years received 203 implants (Ankylos, Dentsply), either in edentulous jaws or after extraction and immediate implant placement. All implants were splinted together with provisional restorations and loaded immediately after surgery. After an average of 60 days, the definitive prostheses were fabricated and cemented provisionally. Thirty-one prostheses were delivered. A total of 92 units on distal cantilevers were incorporated into the prostheses. Implant stability was recorded (via percussion testing) after prostheses were removed and crestal bone levels were measured with radiographs. Average crestal bone loss was 0.33 mm. After a follow-up of 5 years, only one prosthesis broke (at the connection between the main part of the denture and the distal extension). A total of five implants were lost because of overloading or peri-implantitis (during early healing). The success rate of implants was 94.5%, the survival rate was 97.5%, and the survival rate of the prostheses was 96.7% after a loading period of 79.30 ± 35.31 months. Based on the long-term clinical data, distal cantilevers on a full-arch prosthesis can be a successful treatment modality and can be employed in patient treatment planning when posterior support is indicated.

  18. Adaption and Standardization of the Test of Visual-Motor Skills Revised

    Directory of Open Access Journals (Sweden)

    Mozhgan Farahbod

    2004-06-01

    Full Text Available Objective: This research has been carried out with the aim of adaptation, standardization and finding the validity and reliability of Visual-Motor Skills-revised Test for children. Materials & Methods: A multi-stage sampling from the children of the city of Tehran resulted in a sample of 1281 subjects, ages 2,11 through 13,11.the test consisted of 23 geometric designs and each of the designs was assessed through a definite criteria and was scored as errors(weakness and accuracies(strength.For adaptation and standardization of this test, at first step the examiner`s manual and the test items were translated into Farsi. The final form of the test was obtained after performing the pre-tryout and tryout stages, and doing the data analysis by classic model of reliability. Internal consistency coefficients of the subtests were obtained by Cronbach`s Alpha time consistency of the subtests and compound scores were obtained by test-retest. Alpha coefficients for the compound scores were obtained by Guilford formula, which is designed for estimating the compound scores. To obtain the content validity, criterion-related validity and construct validity of the subtests and compound scores, appropriate methods were used. Results: The results obtained ensure the applicability of this test for the evaluation of visual-motor skills of children of Tehran. Conclusion: According to the findings, this test can be used for the disorders in eye-hand coordination, the identification of children with disorders in visual – motor skills. It can also be used for the documentation of the development of fine – motor skills specially in visual – motor skills in 3-14 years – old children.

  19. Elbow joint biomechanics for preclinical evaluation of total elbow prostheses.

    Science.gov (United States)

    Kincaid, Brian L; An, Kai-Nan

    2013-09-27

    Total elbow arthroplasty is a clinically successful procedure, yet long-term implant survival rates have historically lagged behind those reported for total hips and knees. Clinical complications associated with implant wear, osteolysis, stem loosening and device fracture have been implicated as reasons for limited long-term survivorship. Unfortunately, there is little published information on the biomechanics and method(s) for preclinical evaluation of total elbow prostheses that could provide insight into the mechanisms of failure. Additionally, there are no consensus testing standards or summaries of loading profiles of the humero-ulnar joint associated with a range of activities of daily living. Such data would facilitate the standardized preclinical assessment of total elbow devices such is commonplace for other large joints. The objective of the work here is therefore to provide a comprehensive review of elbow joint biomechanics as it relates to preclinical evaluation of total elbow implants. This summary includes a review of elbow joint forces, kinematics, the types and frequency of humero-ulnar joint motions associated with activities of daily living and clinical outcomes, as well as proposing a methodology for deriving humero-ulnar joint reaction force magnitudes and vector orientations as a function of a known mass/force at the hand. From these data, a scalable, bi-axial loading profile is proposed as a foundation for the development of clinically relevant, laboratory simulations for assessment of total elbow prostheses performance. © 2013 Elsevier Ltd. All rights reserved.

  20. Impact of visual cues on directional benefit and preference: Part I--laboratory tests.

    Science.gov (United States)

    Wu, Yu-Hsiang; Bentler, Ruth A

    2010-02-01

    The purpose of the laboratory tests of the current investigation was to examine how visual cues impact directional (DIR) benefit and preference for the DIR microphone hearing aid (re: the omnidirectional [OMNI] microphone). Specifically, three hypotheses were examined: (1) the presence of visual cues would improve OMNI-aided performance to ceiling levels and therefore reduce DIR benefit and preference, (2) DIR benefit measured in the audiovisual (AV) condition could not be predicted by that measured using auditory-only (AO) testing, and (3) with visual cues, listeners with greater lipreading skills would perceive less DIR benefit than did listeners with lesser lipreading skills. Twenty-four adults with sensorineural hearing loss were recruited. Their speech recognition performances were measured in two hearing aid microphone modes (DIR and OMNI), at various signal-to-noise ratios (SNR, -10 to +10 dB in 4-dB steps) and under two presentation conditions (AV and AO) by using the AV version of the Connected Speech Test. Microphone preference (DIR versus OMNI) was also assessed with and without visual cues at each of the SNRs by using the same Connected Speech Test sentences. Lipreading skills were measured using the Utley test. The speech recognition data revealed that the participants obtained significantly less DIR benefit in the AV condition because their AV performances were at the ceiling level. Consistent with this, the likelihood of preferring DIR processing was significantly reduced when visual cues were available to the listeners. Further, DIR benefit measured in the AV condition was not correlated with that measured in the AO condition while being significantly and negatively correlated with lipreading skill. These results suggest that AO laboratory testing overestimates the DIR benefit and preference for DIR processing that hearing aid users may have in most face-to-face conversations in typical SNR, real-world environments. Additionally, because the DIR

  1. A study on reproducing silicone shade guide for maxillofacial prostheses matching Indian skin color

    Directory of Open Access Journals (Sweden)

    Guttal Satyabodh

    2008-01-01

    Full Text Available Aim: The value and success of a well-fitting and anatomically correct prosthesis are compromised if the color does not match the adjoining tissues. The use of powder colors to help develop a simplified silicone shade guide to aid in the fabrication of silicone facial prostheses for Indian patients has been described here. Materials and Methods: Ten powder pigments were used to fabricate the silicone samples for three different subjects having light, medium and dark complexions who were separated into three groups depending on the value of their shades. Four-step wedge silicone samples with thickness variations of 1, 2, 4 and 6mm were fabricated. Visual assessment of the samples was done by four evaluators to check the agreement of color match. Data was statistically analyzed using kappa coefficients. Results: The kappa values were found to be 0.09-0.44 for a light skin tone, -0.11 to 0.77 for medium skin and 0.44 to 0.85 for dark skin tones. This study showed that the samples of dark skin tone matched the skin tone well and showed a statistically good agreement. To further test the validity of these shade guides, facial silicone veneers were fabricated for three patients having light, medium and dark complexion. The color matching showed satisfactory results. Conclusion: The silicone veneers matched the skin color of all three patients. Hence, this shade guide will help clinicians to obtain a good intrinsic shade and minimize extrinsic coloration.

  2. The Use of Dynamic Visual Acuity as a Functional Test of Gaze Stabilization Following Space Flight

    Science.gov (United States)

    Peters, B. T.; Mulavara, A. P.; Brady, R.; Miller, C. A.; Richards, J. T.; Warren, L. E.; Cohen, H. S.; Bloomberg, J. J.

    2006-01-01

    After prolonged exposure to a given gravitational environment the transition to another is accompanied by adaptations in the sensorimotor subsystems, including the vestibular system. Variation in the adaptation time course of these subsystems, and the functional redundancies that exist between them make it difficult to accurately assess the functional capacity and physical limitations of astro/cosmonauts using tests on individual subsystems. While isolated tests of subsystem performance may be the only means to address where interventions are required, direct measures of performance may be more suitable for assessing the operational consequences of incomplete adaptation to changes in the gravitational environment. A test of dynamic visual acuity (DVA) is currently being used in the JSC Neurosciences Laboratory as part of a series of measures to assess the efficacy of a countermeasure to mitigate postflight locomotor dysfunction. In the current protocol, subjects visual acuity is determined using Landolt ring optotypes presented sequentially on a computer display. Visual acuity assessments are made both while standing and while walking at 1.8 m/s on a motorized treadmill. The use of a psychophysical threshold detection algorithm reduces the required number of optotype presentations and the results can be presented immediately after the test. The difference between the walking and standing acuity measures provides a metric of the change in the subject s ability to maintain gaze fixation on the visual target while walking. This functional consequence is observable regardless of the underlying subsystem most responsible for the change. Data from 15 cosmo/astronauts have been collected following long-duration (approx. 6 months) stays in space using a visual target viewing distance of 4.0 meters. An investigation of the group mean shows a change in DVA soon after the flight that asymptotes back to baseline approximately one week following their return to earth. The

  3. Visual and laser Doppler perfusion scanning assessments of Kathon CG patch test reactions.

    Science.gov (United States)

    Bjarnason, B; Fischer, T

    1998-12-01

    Testing procedure for Kathon CG (Diagnostics AB, Tygelsjö, Sweden) is not standardized. To improve test results for Kathon CG. Eleven subjects were tested with Kathon CG patch tests applied from 6 to 96 hours. Tests were read visually and by a laser Doppler perfusion scanning technique at time points ranging from 6 to 240 hours. There were large differences in the perfusion profiles of subjects tested in identical fashion. Beginning reactions were detected earlier with the laser Doppler scanning than with the visual assessment technique. There was no obvious agreement between peak perfusion values of reactions and application times. Both assessment techniques were effective at distinguishing between positive and negative subjects at an adequate dose and application time. This distinction was possible using a shorter reading time with the laser Doppler scanning for all subjects. Six-hour applications were sufficient to detect all positive subjects so tested regardless of assessment technique. With that application time, positive and negative subjects were most effectively identified using long reading times regardless of assessment technique. The shortest application time used on all subjects, 24 hours, was effective and 6-hour applications with long reading times for all subjects so tested. Doses lower than 0.0040 mg/cm2 resulted in false-negative tests.

  4. Evaluation of a visual acuity test using closed Landolt-Cs to determine malingering.

    Science.gov (United States)

    Kröger, Nils; Jürgens, Clemens; Kohlmann, Thomas; Tost, Frank

    2017-12-01

    To evaluate a visual acuity test (VAT) with unexpected optotypes to detect malingering. We tested two groups. Group 1 consisted of 20 individuals with normal best corrected visual acuity (BCVA). Group 2 included participants with ocular diseases and reduced BCVA. All subjects underwent a VAT proposed by Gräf and Roesen to assess suspected malingering. This test used 36 charts with one Landolt-C per page. The first 20 optotypes were Landolt-Cs, while at positions 21, 26, 30, and 34 closed rings were presented. The testing distance was adapted to 50% of the test person's visual acuity. The test person was requested to name the gap direction of the Landolt-C within 3 s. The complete testing conversation was recorded digitally to determine response latency for each optotype from the audio tracks. The average response time was 0.46 s in group 1 and 0.45 s in group 2 for the first 20 Landolt-Cs. In both groups the response time was significantly extended (p ring compared to the mean of the first 20 Landolt-Cs, (group 1: 2.9 s; group 2: 2.3 s). The following three closed rings had also longer response times. However, these differences were not significant. Our results suggest that the proposed test may be helpful to evaluate ocular malingering. The testing procedure appeared to be feasible and showed good repeatability. The fast training effect may be a limitation for malingering detection.

  5. Test-retest reliability of freesurfer measurements within and between sites: Effects of visual approval process.

    Science.gov (United States)

    Iscan, Zafer; Jin, Tony B; Kendrick, Alexandria; Szeglin, Bryan; Lu, Hanzhang; Trivedi, Madhukar; Fava, Maurizio; McGrath, Patrick J; Weissman, Myrna; Kurian, Benji T; Adams, Phillip; Weyandt, Sarah; Toups, Marisa; Carmody, Thomas; McInnis, Melvin; Cusin, Cristina; Cooper, Crystal; Oquendo, Maria A; Parsey, Ramin V; DeLorenzo, Christine

    2015-09-01

    In the last decade, many studies have used automated processes to analyze magnetic resonance imaging (MRI) data such as cortical thickness, which is one indicator of neuronal health. Due to the convenience of image processing software (e.g., FreeSurfer), standard practice is to rely on automated results without performing visual inspection of intermediate processing. In this work, structural MRIs of 40 healthy controls who were scanned twice were used to determine the test-retest reliability of FreeSurfer-derived cortical measures in four groups of subjects-those 25 that passed visual inspection (approved), those 15 that failed visual inspection (disapproved), a combined group, and a subset of 10 subjects (Travel) whose test and retest scans occurred at different sites. Test-retest correlation (TRC), intraclass correlation coefficient (ICC), and percent difference (PD) were used to measure the reliability in the Destrieux and Desikan-Killiany (DK) atlases. In the approved subjects, reliability of cortical thickness/surface area/volume (DK atlas only) were: TRC (0.82/0.88/0.88), ICC (0.81/0.87/0.88), PD (0.86/1.19/1.39), which represent a significant improvement over these measures when disapproved subjects are included. Travel subjects' results show that cortical thickness reliability is more sensitive to site differences than the cortical surface area and volume. To determine the effect of visual inspection on sample size required for studies of MRI-derived cortical thickness, the number of subjects required to show group differences was calculated. Significant differences observed across imaging sites, between visually approved/disapproved subjects, and across regions with different sizes suggest that these measures should be used with caution. © 2015 Wiley Periodicals, Inc.

  6. A randomized controlled clinical trial of 3-unit posterior zirconia–ceramic fixed dental prostheses (FDP) with layered or pressed veneering ceramics: 3-year results

    OpenAIRE

    Naenni, Nadja; Bindl, Andreas; Sax, Caroline; Hämmerle, Christoph; Sailer, Irena

    2015-01-01

    The aim of the present pilot study was to test whether or not posterior zirconia-ceramic fixed dental prostheses (FDPs) with pressed veneering ceramic exhibit less chipping than FDPs with layered veneering ceramics

  7. The association between various visual function tests and low fragility hip fractures among the elderly: a Malaysian experience.

    Science.gov (United States)

    Chew, Fiona L M; Yong, Chee-Khuen; Mas Ayu, S; Tajunisah, I

    2010-03-01

    hip fractures are an increasing source of morbidity and mortality in older people. The role of visual function tests such as visual impairment, stereopsis, contrast sensitivity and visual field defects in low fragility hip fractures in Asian populations is not well understood. to determine the association between various visual function tests and low fragility hip fractures in an Asian population. case-control study. University Malaya Medical Centre, Kuala Lumpur, Malaysia. 108 cases aged > or = 55 years admitted with low fragility fractures and 108 controls (matched for age, gender and race). both cases and controls underwent a detailed ophthalmological examination, which included visual acuity, stereopsis, contrast sensitivity and visual field testing. poorer visual acuity (odds ratio, OR = 4.08; 95% confidence interval, CI: 1.44, 11.51), stereopsis (OR = 3.60, 95% CI: 1.55, 8.38), contrast sensitivity (OR = 3.34, 95% CI: 1.48, 7.57) and visual field defects (OR = 11.60, 95% CI: 5.21, 25.81) increased the risk of fracture. Increased falls were associated with poorer visual acuity (OR = 2.30, 95% CI: 1.04, 5.13), stereopsis (OR = 2.11, 95% CI: 1.03, 4.32), contrast sensitivity (OR = 2.12, 95% CI: 1.05, 4.30) and visual field defects (OR = 3.40, 95% CI: 1.69, 6.86). impaired visual acuity, stereopsis, contrast sensitivity and visual field defects are associated with an increased risk of low fragility hip fractures. We recommend that all patients aged > or = 55 should have an annual ophthalmological examination that includes visual acuity, contrast sensitivity, stereopsis and visual field testing to assess the risks for falls and low fragility fractures.

  8. NDE Technology Development Program for Non-Visual Volumetric Inspection Technology; Sensor Effectiveness Testing Report

    Energy Technology Data Exchange (ETDEWEB)

    Moran, Traci L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Larche, Michael R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Denslow, Kayte M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glass, Samuel W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-08-31

    The Pacific Northwest National Laboratory (PNNL) located in Richland, Washington, hosted and administered Sensor Effectiveness Testing that allowed four different participants to demonstrate the NDE volumetric inspection technologies that were previously demonstrated during the Technology Screening session. This document provides a Sensor Effectiveness Testing report for the final part of Phase I of a three-phase NDE Technology Development Program designed to identify and mature a system or set of non-visual volumetric NDE technologies for Hanford DST primary liner bottom inspection. Phase I of the program will baseline the performance of current or emerging non-visual volumetric NDE technologies for their ability to detect and characterize primary liner bottom flaws, and identify candidate technologies for adaptation and maturation for Phase II of the program.

  9. Interrater and Test-Retest Reliability of the Beery Visual-Motor Integration in Schoolchildren.

    Science.gov (United States)

    Harvey, Erin M; Leonard-Green, Tina K; Mohan, Kathleen M; Kulp, Marjean Taylor; Davis, Amy L; Miller, Joseph M; Twelker, J Daniel; Campus, Irene; Dennis, Leslie K

    2017-05-01

    To assess interrater and test-retest reliability of the 6th Edition Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI) and test-retest reliability of the VMI Visual Perception Supplemental Test (VMIp) in school-age children. Subjects were 163 Native American third- to eighth-grade students with no significant refractive error (astigmatism tests were scored by two trained scorers, and a subset of 50 tests was also scored by an experienced scorer. Scorers strictly applied objective scoring criteria. Analyses included interrater and test-retest assessments of bias, 95% limits of agreement, and intraclass correlation analysis. Trained scorers had no significant scoring bias compared with the experienced scorer. One of the two trained scorers tended to provide higher scores than the other (mean difference in standardized scores = 1.54). Interrater correlations were strong (0.75 to 0.88). VMI and VMIp test-retest comparisons indicated no significant bias (subjects did not tend to score better on retest). Test-retest correlations were moderate (0.54 to 0.58). The 95% limits of agreement for the VMI were -24.14 to 24.67 (scorer 1) and -26.06 to 26.58 (scorer 2), and the 95% limits of agreement for the VMIp were -27.11 to 27.34. The 95% limit of agreement for test-retest differences will be useful for determining if the VMI and VMIp have sufficient sensitivity for detecting change with treatment in both clinical and research settings. Further research on test-retest reliability reporting 95% limits of agreement for children across different age ranges is recommended, particularly if the test is to be used to detect changes due to intervention or treatment.

  10. Recognition versus Resolution: a Comparison of Visual Acuity Results Using Two Alternative Test Chart Optotype

    OpenAIRE

    Jonathan S. Pointer

    2008-01-01

    Purpose: To quantify the difference between recognition (letter) and resolution (Landolt) visual acuity (VA) in a group of normally sighted subjects. Is it reasonable to assume that the two acuity measures are clinically equivalent? Methods: A pair of 6 m acuity test charts was produced: one comprised letters and the other Landolt broken rings. Construction of both charts conformed to the logMAR design format. Monocular VA was determined for the dominant eye of 300 screened and normally si...

  11. Oculomotor Reflexes as a Test of Visual Dysfunctions in Cognitively Impaired Observers

    Science.gov (United States)

    2013-09-01

    oculomotor reflexes. All hardware and software components of the data acquisition and analysis pipeline were finalized and tested in realistic... Gantt chart for the project. As specified in the Statement of Work, the main goal of the first 12 months of the project was to design e↵ective stimuli...be translated to the probabilities of various visual dysfunctions, hence validating the proposed diagnostic method. Figure 1 shows a Gantt chart

  12. Metal release from hip prostheses: cobalt and chromium toxicity and the role of the clinical laboratory.

    Science.gov (United States)

    Campbell, Jonathon R; Estey, Mathew P

    2013-01-01

    Individuals with advanced hip disease suffer from pain, impaired hip function, and decreased quality of life. Roughly one million metal-on-metal (MoM) hip prostheses have been implanted worldwide in order to ameliorate these issues. While most MoM hip replacements are successful, some patients suffer from serious adverse effects secondary to the release of metal debris due to implant wear and corrosion. MoM hip prostheses are comprised predominantly of cobalt and chromium, and the serum concentration of these metal ions has been shown to correlate with both implant wear and the accumulation of metal debris in the periprosthetic tissue. Consequently, measurement of cobalt and chromium concentrations may be useful in the assessment of implant function and the potential for adverse effects in the follow-up of patients with MoM hip prostheses. The purpose of this Mini Review is to describe the adverse biological consequences of metal release from hip prostheses, provide an overview of the clinical utility of cobalt and chromium measurement and the current recommendations for testing, and alert laboratorians and physicians to the many challenges associated with measuring these metal ions.

  13. Reduction of metal artifacts from hip prostheses on CT images of the pelvis: value of iterative reconstructions.

    Science.gov (United States)

    Morsbach, Fabian; Bickelhaupt, Sebastian; Wanner, Guido A; Krauss, Andreas; Schmidt, Bernhard; Alkadhi, Hatem

    2013-07-01

    To assess the value of iterative frequency split-normalized (IFS) metal artifact reduction (MAR) for computed tomography (CT) of hip prostheses. This study had institutional review board and local ethics committee approval. First, a hip phantom with steel and titanium prostheses that had inlays of water, fat, and contrast media in the pelvis was used to optimize the IFS algorithm. Second, 41 consecutive patients with hip prostheses who were undergoing CT were included. Data sets were reconstructed with filtered back projection, the IFS algorithm, and a linear interpolation MAR algorithm. Two blinded, independent readers evaluated axial, coronal, and sagittal CT reformations for overall image quality, image quality of pelvic organs, and assessment of pelvic abnormalities. CT attenuation and image noise were measured. Statistical analysis included the Friedman test, Wilcoxon signed-rank test, and Levene test. Ex vivo experiments demonstrated an optimized IFS algorithm by using a threshold of 2200 HU with four iterations for both steel and titanium prostheses. Measurements of CT attenuation of the inlays were significantly (P algorithm for CT image reconstruction significantly reduces metal artifacts from hip prostheses, improves the reliability of CT number measurements, and improves the confidence for depicting pelvic abnormalities.

  14. Early visual ERPs show stable body-sensitive patterns over a 4-week test period

    Science.gov (United States)

    Groves, Katie; Kennett, Steffan; Gillmeister, Helge

    2018-01-01

    Event-related potential (ERP) studies feature among the most cited papers in the field of body representation, with recent research highlighting the potential of ERPs as neuropsychiatric biomarkers. Despite this, investigation into how reliable early visual ERPs and body-sensitive effects are over time has been overlooked. This study therefore aimed to assess the stability of early body-sensitive effects and visual P1, N1 and VPP responses. Participants were asked to identify pictures of their own bodies, other bodies and houses during an EEG test session that was completed at the same time, once a week, for four consecutive weeks. Results showed that amplitude and latency of early visual components and their associated body-sensitive effects were stable over the 4-week period. Furthermore, correlational analyses revealed that VPP component amplitude might be more reliable than VPP latency and specific electrode sites might be more robust indicators of body-sensitive cortical activity than others. These findings suggest that visual P1, N1 and VPP responses, alongside body-sensitive N1/VPP effects, are robust indications of neuronal activity. We conclude that these components are eligible to be considered as electrophysiological biomarkers relevant to body representation. PMID:29438399

  15. MPEG-7 audio-visual indexing test-bed for video retrieval

    Science.gov (United States)

    Gagnon, Langis; Foucher, Samuel; Gouaillier, Valerie; Brun, Christelle; Brousseau, Julie; Boulianne, Gilles; Osterrath, Frederic; Chapdelaine, Claude; Dutrisac, Julie; St-Onge, Francis; Champagne, Benoit; Lu, Xiaojian

    2003-12-01

    This paper reports on the development status of a Multimedia Asset Management (MAM) test-bed for content-based indexing and retrieval of audio-visual documents within the MPEG-7 standard. The project, called "MPEG-7 Audio-Visual Document Indexing System" (MADIS), specifically targets the indexing and retrieval of video shots and key frames from documentary film archives, based on audio-visual content like face recognition, motion activity, speech recognition and semantic clustering. The MPEG-7/XML encoding of the film database is done off-line. The description decomposition is based on a temporal decomposition into visual segments (shots), key frames and audio/speech sub-segments. The visible outcome will be a web site that allows video retrieval using a proprietary XQuery-based search engine and accessible to members at the Canadian National Film Board (NFB) Cineroute site. For example, end-user will be able to ask to point on movie shots in the database that have been produced in a specific year, that contain the face of a specific actor who tells a specific word and in which there is no motion activity. Video streaming is performed over the high bandwidth CA*net network deployed by CANARIE, a public Canadian Internet development organization.

  16. Early detection of dementia in multilingual populations: Visual Cognitive Assessment Test (VCAT).

    Science.gov (United States)

    Kandiah, Nagaendran; Zhang, Angeline; Bautista, Dianne Carol; Silva, Eveline; Ting, Simon Kang Seng; Ng, Adeline; Assam, Pryseley

    2016-02-01

    Early diagnosis of cognitive impairment allows timely intervention with pharmacological and non-pharmacological measures. However, current cognitive evaluation tools do not cater for multilingual populations. To develop and validate a visual-based cognitive evaluation tool, the Visual Cognitive Assessment Test (VCAT), which can be administered to multilingual populations without the need for translation or adaptation. We designed a battery of tests to evaluate the domains of memory, executive function, visuospatial function, language and attention. Pilot testing of individual test items, followed by test refinement and development of a field version was performed. We subsequently validated VCAT for the diagnosis of mild cognitive impairment (MCI) and mild Alzheimer's disease (AD). Diagnostic performance was assessed by the area under the curve (AUC), sensitivity (Se) and specificity (Sp). VCAT was validated in a sample of 206 participants. The sample comprised 53.9% males; mean age (SD) was 67.8 (8.86) years; mean years of education was 10.5(6.0). AUC of VCAT for detection of cognitive impairment was found to be 93.3 (95% CI 90.1 to 96.4). Also, the Se and Sp of VCAT for the diagnosis of cognitive impairment (MCI and mild AD) were 85.6% and 81.1%, respectively. VCAT's diagnostic Se and Sp comparable to those of the Montreal Cognitive Assessment in the same cohort. Mean time-to-complete VCAT was 15.7 ± 7.3 min. The VCAT has good Se and Sp for the diagnosis of MCI and mild AD. The visual-based test paradigm allows easy application to multilingual populations without the need for translation or adaptation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  17. Training Guidelines in Non-Destructive Testing Techniques: Manual for Visual Testing at Level 2

    International Nuclear Information System (INIS)

    2013-01-01

    The International Atomic Energy Agency (IAEA) has been active in the promotion of non-destructive testing (NDT) technology for many decades. The prime reason for this interest has been the need for stringent quality control standards for safe operation of nuclear as well as other industrial installations. The IAEA has successfully executed a number of projects, including technical cooperation projects (national and regional) and coordinated research projects, in which NDT was an important part. Through these projects, a large number of persons have been trained in numerous Member States, leading to the establishment of national certifying bodies responsible for training and certification of NDT personnel. Consequently a state of self-sufficiency in this area of technology has been achieved in many of these States. All along there has been a realization of the need to have well established training guidelines and related books, in order, first, to guide IAEA experts involved in this training programme and, second, to achieve some level of international uniformity and harmonization of training materials and consequent competence of NDT personnel. The syllabuses for training courses have been published in the form of TECDOC publications. The first was IAEA-TECDOC-407 (1987), which contained syllabuses for the five basic NDT methods: liquid penetrant testing, magnetic particle testing, eddy current testing, radiographic testing and ultrasonic testing. To accommodate advancements in NDT technology, later versions of this publication were issued in 1991, 2002 and 2008, with the current version being IAEA-TECDOC- 628/Rev.2 (2008), which includes additional and more advanced NDT methods. The next logical step was to compile textbooks and training manuals in accordance with these syllabuses. Manuals on liquid penetrant, magnetic particle, radiographic, ultrasonic and eddy current testing have already been published in the Training Course Series. These play a vital role in

  18. Iq Test Program Application for Senior High School Level Using Microsoft Visual Basic 6.0

    OpenAIRE

    Deni Kurniawan; Sahni Damerianta,SKom, MMSI

    2003-01-01

    Scientific writing contains a description of the IQ test programs, which are measuring the level of intelligence, psychological aspects, and the direction of interest in accordance with the ability of a student who was still in high school and sat dibangku second class who later IQ tests would also determine the direction will get students at third grade, using Microsoft Visual Basic 6.0.As for the first time that must be filled in this application is the biodata of students, such as: Number ...

  19. SPONGE ROBOTIC HAND DESIGN FOR PROSTHESES

    OpenAIRE

    Mine Seçkin

    2016-01-01

    In this study robotic hands and fingers’ materials are investigated from past to present and a sponge robotic hand is designed for biomedical applications. Emergence and necessity of soft robotic technology are explained and description of soft robot is made. Because of the importance of hand in a person’s body, researchers have dealt with robotic hand prostheses for many centuries and developed many hand types. To mimic the best for the human limbs, softness of the hand is one of the importa...

  20. Stimulation and recording electrodes for neural prostheses

    CERN Document Server

    Pour Aryan, Naser; Rothermel, Albrecht

    2015-01-01

    This book provides readers with basic principles of the electrochemistry of the electrodes used in modern, implantable neural prostheses. The authors discuss the boundaries and conditions in which the electrodes continue to function properly for long time spans, which are required when designing neural stimulator devices for long-term in vivo applications. Two kinds of electrode materials, titanium nitride and iridium are discussed extensively, both qualitatively and quantitatively. The influence of the counter electrode on the safety margins and electrode lifetime in a two electrode system is explained. Electrode modeling is handled in a final chapter.

  1. To Further the Near-Vision Visual Acuity Tests (3): For a Test Which Saves Time, Labor, and Expenses

    OpenAIRE

    高橋, ひとみ; 川端, 秀仁; 衞藤, 隆

    2014-01-01

    The Ministry of Education, Culture, Sports, Science and Technology of Japan has its advisory board to review the list of medical checkup for school children every ten years. In August 2013 the board found that there was a considerable number of school children who had poor near vision and thus learn in the class less efficiently. The board recommended that the Ministry consider whether to include a near-vision visual acuity test in a regular medical examination at school. It may not be known ...

  2. Immediate versus conventional loading with fixed full-arch prostheses in mandibles with failing dentition: a prospective controlled study.

    Science.gov (United States)

    Peñarrocha-Oltra, David; Covani, Ugo; Peñarrocha, Miguel; Peñarrocha-Diago, Maria

    2015-01-01

    To compare immediate and conventional loading protocols for fixed full-arch mandibular prostheses supported by immediate and nonimmediate implants. A prospective controlled nonrandomized study with 12 months of follow-up included patients requiring fixed full-arch rehabilitations supported by immediate and nonimmediate implants. Eighteen patients were treated with conventional loading (control group), and 18 were treated with immediate loading (test group). Each patient received four to six implants; implants with insertion torque loaded conventionally. The following variables were assessed: implant success, biologic and prosthetic complications, success of the immediately loaded provisional prostheses, and marginal bone loss. Statistical analysis was performed with nonparametric tests (chi-square, Mann-Whitney, Kruskal-Wallis) with an alpha value of .05. Thirty-six patients consecutively enrolled in the study. Two control group patients failing to attend control visits and 12 implants that did not achieve an insertion torque of 35 Ncm were excluded. The final sample consisted of 34 patients and 183 implants (98 test and 85 control implants). Implant success rates were 99.0% (test) and 97.6% (control). Within the test group, success rates for immediate and nonimmediate implants were 100% and 97.6%, respectively. Differences were not statistically significant. All immediately loaded prostheses were successful. Five provisional fixed prostheses presented with loosened screws; all control group patients reported discomfort with the provisional denture. Average bone loss was 0.71 mm (standard deviation 0.25 mm) in the test group and 0.60 mm (standard deviation 0.28 mm) in the control group. No significant differences were seen in implant success and peri-implant marginal bone loss between immediate and conventional loading of mandibular fixed full-arch prostheses supported by immediate and nonimmediate implants. Biologic and prosthetic complications were rare, and all

  3. Retinal, optic nerve and chiasmal function following radiation therapy demonstrated by visual evoked response testing

    International Nuclear Information System (INIS)

    Soni, A.B.; Constine, L.S.; Smith, D.; Palisca, M.; Ojomo, K.; Muhs, A.

    1997-01-01

    Purpose: To evaluate the tolerance of the retina, optic nerve, and optic chiasm to radiation doses conventionally used to treat patients with primary brain or pituitary tumors and to explore the character of detectable radiation effects. Visual evoked response (VER) testing is a noninvasive and sensitive method for identifying radiation injury to the visual system due to alterations in small vessel or myelin integrity. Such evaluations may increase our understanding of the threshold for and the pathogenesis of radiation injury. Materials and Methods: Twenty-four patients irradiated for brain or pituitary tumors between 1972 and 1996 had VER testing. Patients were included in study if the retina, optic nerves or chiasm were in the radiation (RT) field. At the time of RT patients ranged in age from 1.5 to 55 years (median 33). Mean doses were as follows: right retina, 29 Gy (range 10 - 60 Gy); left retina, 29.5 Gy (range 10 - 60 Gy); right optic nerve, 42.9 Gy (range 10 - 60 Gy); left optic nerve, 42.6 Gy (range 10 - 60 Gy); and optic chiasm, 48.2 Gy (range 10 - 65 Gy). Daily fractionation ranged from 1.5 to 1.8 Gy. Pattern VER testing distinguishes compressive or ischemic effects of tumor on the visual system from radiation retinopathy or optic neuropathy on the basis of the conduction amplitude and delay pattern. Prechiasm, chiasm, and postchiasm injuries are distinguishable by analyzing VER changes. Four evoked responses were obtained for each eye, each representing the average of 100 stimulus reversals. Results: VER was normal in 11 patients and abnormal in 13 patients. Only 2 patients (8%) had VER evidence of radiation injury to the visual system, one of whom had visual compromise. The other 11 abnormal patients had characteristic VER changes attributable to tumor or surgical damage. There was no significant difference in the radiation doses given to any subgroup. The one patient with radiation retinopathy had received 55-60 Gy to the posterior globe. Ten years

  4. Time limits in testing: An analysis of eye movements and visual attention in spatial problem solving.

    Science.gov (United States)

    Roach, Victoria A; Fraser, Graham M; Kryklywy, James H; Mitchell, Derek G V; Wilson, Timothy D

    2017-11-01

    Individuals with an aptitude for interpreting spatial information (high mental rotation ability: HMRA) typically master anatomy with more ease, and more quickly, than those with low mental rotation ability (LMRA). This article explores how visual attention differs with time limits on spatial reasoning tests. Participants were assorted to two groups based on their mental rotation ability scores and their eye movements were collected during these tests. Analysis of salience during testing revealed similarities between MRA groups in untimed conditions but significant differences between the groups in the timed one. Question-by-question analyses demonstrate that HMRA individuals were more consistent across the two timing conditions (κ = 0.25), than the LMRA (κ = 0.013). It is clear that the groups respond to time limits differently and their apprehension of images during spatial problem solving differs significantly. Without time restrictions, salience analysis suggests LMRA individuals attended to similar aspects of the images as HMRA and their test scores rose concomitantly. Under timed conditions however, LMRA diverge from HMRA attention patterns, adopting inflexible approaches to visual search and attaining lower test scores. With this in mind, anatomical educators may wish to revisit some evaluations and teaching approaches in their own practice. Although examinations need to evaluate understanding of anatomical relationships, the addition of time limits may induce an unforeseen interaction of spatial reasoning and anatomical knowledge. Anat Sci Educ 10: 528-537. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

  5. Oral cavity anaerobic pathogens in biofilm formation on voice prostheses

    NARCIS (Netherlands)

    Bertl, Kristina; Zijnge, Vincent; Zatorska, Beata; Leonhard, Matthias; Schneider-Stickler, Berit; Harmsen, Hermie J. M.

    BACKGROUND: A polymerase chain reaction (PCR)-based method has been used to identify oral anaerobic pathogens in biofilms on voice prostheses. The purpose of the present study was to determine the location of those pathogens inside the biofilms. METHODS: Biofilms of 15 voice prostheses were sampled

  6. Lactobacilli : Important in biofilm formation on voice prostheses

    NARCIS (Netherlands)

    Buijssen, Kevin J. D. A.; Harmsen, Hermie J. M.; van der Mei, Henny C.; Busscher, Henk J.; van der Laan, Bernard F. A. M.

    OBJECTIVE: We sought to identify bacterial strains responsible for biofilm formation on silicone rubber voice prostheses. STUDY DESIGN: We conducted an analysis of the bacterial population in biofilms on used silicone rubber voice prostheses by using new microbiological methods. METHODS: Two

  7. Radial Force: An Underestimated Parameter in Oversizing Transcatheter Aortic Valve Replacement Prostheses: In Vitro Analysis with Five Commercialized Valves.

    Science.gov (United States)

    Egron, Sandrine; Fujita, Buntaro; Gullón, Lucía; Désirée, Pott; Schmitz-Rode, Thomas; Ensminger, Stephan; Steinseifer, Ulrich

    2017-09-05

    The goal is to inform in depth on transcatheter aortic valve replacement (TAVR) prosthesis mechanical behavior, depending on frame type, design, and size, and how it crucially impacts the oversizing issue in clinical use, and ultimately the procedure outcome. Transcatheter aortic valve replacement is an established therapy for high-risk patients suffering from aortic stenosis, and the indication for TAVR is progressively expanding to intermediate-risk patients. Choosing the optimal oversizing degree is crucial to safely anchor the TAVR valve-which involves limiting the risks for embolism, aortic regurgitation, conductance disturbance, or annulus rupture-and to increase the valve prosthesis performance. The radial force (RF) profiles of five TAVR prostheses were measured in vitro: the CoreValve 23 and 26 (Medtronic, MN), the Acurate neo S (Symetis, Switzerland), and the SAPIEN XT 23 and 26 (Edwards Lifesciences, CA). Measurements were run with the RX Machine equipment (Machine Solutions Inc., AZ), which is used in ISO standard tests for intravascular stents. Test protocols were adapted for TAVR prostheses. With the prostheses RF profiles' results, mechanical behavior differences could be described and discussed in terms of oversizing strategy and clinical impact for all five valves. Besides, crossing the prostheses' RF profiles with their recommended size windows made the assessment of borderline size cases possible and helped analyze the risks when accurate measurement of patient aortic annulus proves difficult. The prostheses' RF profiles bring new support in clinical decision-making for valve type and size in patients.

  8. Testing the impact on natural risks' awareness of visual communication through an exhibition

    Science.gov (United States)

    Charrière, Marie; Bogaard, Thom; Junier, Sandra; Malet, Jean-Philippe; Mostert, Erik

    2014-05-01

    The need to communicate about natural disasters in order to improve the awareness of communities at risk is not a matter for debate anymore. However, communication can be implemented using different media and tools, and their effectiveness may be difficult to grasp. Current research on the topic is usually focused on assessing whether communication practices meet users' needs, whereas impact assessment is mostly left out. It can be explained by difficulties arising from (1) the definition of the impact to measure, i.e. awareness, and the appropriate indicators to measure it and its variations, and (2) the implementation of a research design that allows assessing these impacts without bias. This research aims at both developing a methodology to measure risk awareness and to use it for testing the effectiveness of visual communication. The testing was conducted in the Ubaye Valley in France, an alpine area affected by multiple hazards, from December 2013 to mid-February 2014. The setting consisted of an exhibition in the public library of the main town, Barcelonnette. The main natural hazards of the study case (i.e. landslides, avalanches, flooding, debris flows and earthquakes), as well as structural and non-structural measures were presented to the general public using local examples of hazards events and mitigation. Various visualization tools were used: videos, Google earth map, interactive timeline, objects, mock-ups, technical devices as well as posters with pictures, drawings and graphs. In order to assess the effects of the exhibition on risk awareness, several groups of children and adults were submitted to a research design, consisting of 1) a pre-test, 2) the visit of the exhibition and 3) a post-test similar to the pre-test. Close-ended questions addressed the awareness indicators according to the literature, i.e. worry level, previous experiences with natural hazards events, exposure to awareness raising, ability to mitigate/respond/prepare, attitude to

  9. Visualization of flaws within heavy section ultrasonic test blocks using high energy computed tomography

    International Nuclear Information System (INIS)

    House, M.B.; Ross, D.M.; Janucik, F.X.; Friedman, W.D.; Yancey, R.N.

    1996-05-01

    The feasibility of high energy computed tomography (9 MeV) to detect volumetric and planar discontinuities in large pressure vessel mock-up blocks was studied. The data supplied by the manufacturer of the test blocks on the intended flaw geometry were compared to manual, contact ultrasonic test and computed tomography test data. Subsequently, a visualization program was used to construct fully three-dimensional morphological information enabling interactive data analysis on the detected flaws. Density isosurfaces show the relative shape and location of the volumetric defects within the mock-up blocks. Such a technique may be used to qualify personnel or newly developed ultrasonic test methods without the associated high cost of destructive evaluation. Data is presented showing the capability of the volumetric data analysis program to overlay the computed tomography and destructive evaluation (serial metallography) data for a direct, three-dimensional comparison

  10. The development of a visualization tool for displaying analysis and test results

    International Nuclear Information System (INIS)

    Uncapher, W.L.; Ammerman, D.J.; Ludwigsen, J.S.; Wix, S.D.

    1995-01-01

    The evaluation and certification of packages for transportation of radioactive materials is performed by analysis, testing, or a combination of both. Within the last few years, many transport packages that were certified have used a combination of analysis and testing. The ability to combine and display both kinds of data with interactive graphical tools allows a faster and more complete understanding of the response of the package to these environments. Sandia National Laboratories has developed an initial version of a visualization tool that allows the comparison and display of test and of analytical data as part of a Department of Energy-sponsored program to support advanced analytical techniques and test methodologies. The capability of the tool extends to both mechanical (structural) and thermal data

  11. Mid-term results after implantation of rotating-hinge knee prostheses: primary versus revision

    Directory of Open Access Journals (Sweden)

    Turgay Efe

    2012-12-01

    Full Text Available The aim of the study was to evaluate the mid-term clinical results and survivorship of a rotating-hinge knee prosthesis (LINK® Endo-Model in difficult primary and complex revision situations. Results after primary implantation were compared with those of revision procedures. Forty-nine prostheses in 45 patients were reviewed clinically during follow up. Twenty-one of these were implanted in primary and 28 in revision situations. Outcome was evaluated using commonly used scores (Knee Society, UCLA Activity, Lequesne and a visual analog scale after a mean follow up of 56±37 months for 49 prostheses. Implant survival was analyzed using the Kaplan-Meier method. There were no significant differences in clinical examination and evaluation scores between the two groups (P>0.05. Survival rates at final follow up were 95% after primary implantation and 76% in revision procedures. The risk of prosthesis loss (odds ratio 5.7 was significantly higher after revision procedures (P=0.004. These data suggest that rotating-hinge knee prostheses provided good clinical and functional results in selected cases of advanced primary gonarthrosis associated with severe bone loss, ligamentous instability or comminuted fractures. They also provide good results in revision situations. However, the failure rate was significantly higher in cases of revision surgery.

  12. The Effects of Repeated Testing, Simulated Malingering, and Traumatic Brain Injury on Visual Choice Reaction Time

    Directory of Open Access Journals (Sweden)

    David L Woods

    2015-11-01

    Full Text Available Choice reaction time (CRT, the time required to discriminate and respond appropriately to different stimuli, is a basic measure of attention and processing speed. Here, we describe the reliability and clinical sensitivity of a new CRT test that presents lateralized visual stimuli and adaptively adjusts stimulus onset asynchronies (SOAs using a staircase procedure. Experiment 1 investigated the test-retest reliability in three test sessions at weekly intervals. Performance in the first test session was accurately predicted from age and computer-use regression functions obtained in a previously studied normative cohort. Central processing time (CentPT, the difference between the CRTs and simple reaction time latencies measured in a separate experiment, accounted for 55% of CRT latency and more than 50% of CRT latency variance. Performance improved significantly across the three test sessions. High intraclass correlation coefficients (ICCs were seen for CRTs (0.90, CentPTs (0.87, and an omnibus performance measure (0.81 that combined CRT and minimal SOA (mSOA z-scores. Experiment 2 investigated performance in the same participants when instructed to feign symptoms of traumatic brain injury (TBI: 87% produced abnormal omnibus z-scores. Simulated malingerers showed greater elevations in simple than choice reaction times, and hence reduced CentPTs. Latency-consistency z-scores, based on the difference between the CRTs obtained and those predicted from CentPT latencies, discriminated malingering participants from controls with high sensitivity and specificity. Experiment 3 investigated CRT test performance in military veterans who had suffered combat-related TBI and symptoms of post-traumatic stress disorder and revealed small but significant deficits in performance. The results indicate that the new CRT test shows high test-retest reliability, can assist in detecting participants performing with suboptimal effort, and is sensitive to the effects of

  13. Visual and confocal microscopic interpretation of patch tests to benzethonium chloride and benzalkonium chloride.

    Science.gov (United States)

    Benjamin, Bohaty; Chris, Fricker; Salvador, González; Melissa, Gill; Susan, Nedorost

    2012-08-01

    Quaternary ammonium compounds (Quats), such as benzalkonium chloride (BAC) and benzethonium chloride (BEC), are widely used as antibacterial active ingredients and preservatives in personal care products, disinfectants, and ophthalmic preparations. BAC is known to be a marginal irritant when patch tested at 0.15% aq. Data on BEC are limited. To differentiate irritant from allergic patch test reactions to quaternary ammonium compounds. Eight subjects who were considered likely to react based on history of rash after exposure to disinfectants or a history of prior positive patch test to BAC were recruited, as well as two patients undergoing routine patch testing. BAC (0.15% aq), BAC (0.15% pet), BEC (0.05% aq), BEC (0.15% pet), BEC (0.15% aq), BEC (0.5% aq), sodium lauryl sulfate (2.0%), and deionized water were applied under Finn chambers for 48 h. Four days and 7 days after application, the sites were examined visually and then by in vivo reflectance confocal microscopy (RCM) which was interpreted by blinded experts. Two patients with definite allergic reactions according to visual patch test reads and RCM were clinically relevant. Cross-reaction between BEC and BAC was demonstrated in one patient. RCM imaging correlated well with clinical scoring and interpretation of patch test reactions in terms of irritancy vs. allergy for BEC and BAC. Relevant allergic reactions to quats occur in humans. Possible cross-reaction was noted to occur between BAC and BEC. RCM appears to be a useful tool in distinguishing between irritancy and sensitization during patch testing to BAC and BEC. Further study of prevalence and best test concentration and vehicle is needed. © 2011 John Wiley & Sons A/S.

  14. Reliability and validity of an automated computerized visual acuity and stereoacuity test in children using an interactive video game.

    Science.gov (United States)

    Ma, Dae Joong; Yang, Hee Kyung; Hwang, Jeong-Min

    2013-07-01

    To evaluate the test-retest reliability and validity of the new automated computerized distance visual acuity and stereoacuity test for children, which uses an interactive video game. Retrospective, observational case series. A total of 102 children aged between 3 and 7 years underwent the Snellen visual acuity test, the Distance Randot Stereotest, and the new automated computerized distance visual acuity and stereoacuity test. The test-retest reliability and validity of the automated computerized tests were assessed and compared with the Snellen visual acuity test and the Distance Randot Stereotest with frequency distributions of the differences, Bland-Altman plots, and Deming regression. The automated computerized distance visual acuity test had high test-retest reliability (95% limits of agreement ±0.18 logMAR, 90.0% of the differences within 0.2 logMAR) and acceptable validity as compared with the Snellen visual acuity chart (95% limits of agreement ±0.27 logMAR, 81.3% of the differences within 0.2 logMAR). The automated computerized distance stereoacuity test had high test-retest reliability (95% limits of agreement ±0.29 log arc second, 95.1% of the differences within 0.3 log arc second) and acceptable validity as compared with the Distance Randot Stereotest (95% limits of agreement ±0.35 log arc second, 93.9% of the differences within 0.3 log arc second). The new automated computerized distance visual acuity and stereoacuity test, which uses an interactive video game, has good reliability and acceptable validity compared with the Snellen visual acuity chart and the Distance Randot Stereotest. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Radiological and scintigraphic evaluation of hip prostheses

    International Nuclear Information System (INIS)

    Bessler, W.; Schaub, W.

    1979-01-01

    The radiological findings following the introduction of hip prostheses are often equivocal. Additional bone scintigrams often provide important information for the evaluation of the prostheses. 1. An unstable hip prosthesis is characterised by abnormal uptake in bone, due to static and mechanical stress. 2. A positive scintigram does not necessarily indicate instability of the prosthesis. Increased uptake may also be due to inflammatory bone changes, healing, bone replacement, abnormal local stresses or soft tissue calcification. 3. In evaluating the scintigram one must take account not only of the intensity of isotope uptake, but also its distribution and exact localisation. 4. It is essential to compare the scintigram with the radiograph. Radiological features of possible instability become diagnostic if they correspond with appropriate increased radioactivity. If the latter is absent, the of instability remains doubtful. 5. In some cases early loosening of the stem of the prosthesis can be diagnosed while the radiograph is still negative. Increased radioactivity in the acetabulum is frequently seen in the presence of a stable acetabular prosthesis and must be interpreted with caution as a sign of loosening of the prosthesis. (orig.) [de

  16. [Understanding the elderly user of auditory prostheses].

    Science.gov (United States)

    de Paiva, Karina Mary; Maciel, Paulete Maria Ambrósio; Cintra, Letícia Guedes

    2011-06-01

    The main goal was to identify the factors involved in the application for and use of auditory prostheses by the elderly as well as their awareness of the Policy of Care to Auditory Health. 25 elderly people of both sexes using auditory prostheses in Vitória (Espírito Santo, Brazil) were selected. They were contacted by telephone to participate in the research by answering a questionnaire. The results demonstrated that most of the elderly people interviewed (52%) use the device all day which suggests good adaptation to the process. Thirteen elderly people reported that they contacted the prosthesis company of their own accord. The advantages involved better communication and listening to TV (64%) while the difficulties were due to noisy environments; 56% were unable to understand what was being said at lectures, in church, and on the telephone, 72% reported no improvement with the prosthesis. 88% of the elderly participants are unaware of donation policies for auditory devices and 100% are unaware of this kind of service. Research and practices in health services about auditory issues still have far to go. There is a need for a change in management with the objective of putting into action policies which define the responsibilities of the State.

  17. Equating spatial summation in visual field testing reveals greater loss in optic nerve disease.

    Science.gov (United States)

    Kalloniatis, Michael; Khuu, Sieu K

    2016-07-01

    To test the hypothesis that visual field assessment in ocular disease measured with target stimuli within or close to complete spatial summation results in larger threshold elevation compared to when measured with the standard Goldmann III target size. The hypothesis predicts a greater loss will be identified in ocular disease. Additionally, we sought to develop a theoretical framework that would allow comparisons of thresholds with disease progression when using different Goldmann targets. The Humphrey Field Analyser (HFA) 30-2 grid was used in 13 patients with early/established optic nerve disease using the current Goldmann III target size or a combination of the three smallest stimuli (target size I, II and III). We used data from control subjects at each of the visual field locations for the different target sizes to establish the number of failed points (events) for the patients with optic nerve disease, as well as global indices for mean deviation (MD) and pattern standard deviation (PSD). The 30-2 visual field testing using alternate target size stimuli showed that all 13 patients displayed more defects (events) compared to the standard Goldmann III target size. The median increase for events was seven additional failed points: (range 1-26). The global indices also increased when the new testing approach was used (MD -3.47 to -6.25 dB and PSD 4.32 to 6.63 dB). Spatial summation mapping showed an increase in critical area (Ac) in disease and overall increase in thresholds when smaller target stimuli were used. When compared to the current Goldmann III paradigm, the use of alternate sized targets within the 30-2 testing protocol revealed a greater loss in patients with optic nerve disease for both event analysis and global indices (MD and PSD). We therefore provide evidence in a clinical setting that target size is important in visual field testing. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

  18. Expanded Koppitz Scoring System of the Bender Gestalt Visual-Motor Test for Adolescents: A Pilot Study.

    Science.gov (United States)

    Bolen, Larry M.; And Others

    1992-01-01

    Examined use of Bender Gestalt Visual-Motor Test with school-age adolescents over age 11. Mean error scores suggest that visual-motor development is not maturationally complete by age 11 years, 11 months. Suggests additional research focusing on extending normative sample or developing new scoring system for adolescents. (Author/NB)

  19. The Effect of "Read-Aloud" as a Test Accommodation for Students with Visual Impairments in South Korea

    Science.gov (United States)

    Kim, Jung Sook

    2012-01-01

    Arguing the issue of fairness and the additional advantage for test takers with visual impairments, some professionals have expressed negative attitudes toward test accommodation. However, researchers have found that the validity of test accommodations increases when the test scores of students who need a particular accommodation increases, while…

  20. Visual Advantage of Enhanced Flight Vision System During NextGen Flight Test Evaluation

    Science.gov (United States)

    Kramer, Lynda J.; Harrison, Stephanie J.; Bailey, Randall E.; Shelton, Kevin J.; Ellis, Kyle K.

    2014-01-01

    Synthetic Vision Systems and Enhanced Flight Vision System (SVS/EFVS) technologies have the potential to provide additional margins of safety for aircrew performance and enable operational improvements for low visibility operations in the terminal area environment. Simulation and flight tests were jointly sponsored by NASA's Aviation Safety Program, Vehicle Systems Safety Technology project and the Federal Aviation Administration (FAA) to evaluate potential safety and operational benefits of SVS/EFVS technologies in low visibility Next Generation Air Transportation System (NextGen) operations. The flight tests were conducted by a team of Honeywell, Gulfstream Aerospace Corporation and NASA personnel with the goal of obtaining pilot-in-the-loop test data for flight validation, verification, and demonstration of selected SVS/EFVS operational and system-level performance capabilities. Nine test flights were flown in Gulfstream's G450 flight test aircraft outfitted with the SVS/EFVS technologies under low visibility instrument meteorological conditions. Evaluation pilots flew 108 approaches in low visibility weather conditions (600 feet to 3600 feet reported visibility) under different obscurants (mist, fog, drizzle fog, frozen fog) and sky cover (broken, overcast). Flight test videos were evaluated at three different altitudes (decision altitude, 100 feet radar altitude, and touchdown) to determine the visual advantage afforded to the pilot using the EFVS/Forward-Looking InfraRed (FLIR) imagery compared to natural vision. Results indicate the EFVS provided a visual advantage of two to three times over that of the out-the-window (OTW) view. The EFVS allowed pilots to view the runway environment, specifically runway lights, before they would be able to OTW with natural vision.

  1. Tribology of total hip arthroplasty prostheses

    Science.gov (United States)

    Rieker, Claude B.

    2016-01-01

    Articulating components should minimise the generation of wear particles in order to optimize long-term survival of the prosthesis. A good understanding of tribological properties helps the orthopaedic surgeon to choose the most suitable bearing for each individual patient. Conventional and highly cross-linked polyethylene articulating either with metal or ceramic, ceramic-on-ceramic and metal-on-metal are the most commonly used bearing combinations. All combinations of bearing surface have their advantages and disadvantages. An appraisal of the individual patient’s objectives should be part of the assessment of the best bearing surface. Cite this article: Rieker CB. Tribology of total hip arthroplasty prostheses: what an orthopaedic surgeon should know. EFORT Open Rev 2016;1:52-57. DOI: 10.1302/2058-5241.1.000004. PMID:28461928

  2. Signal-Amplified Lateral Flow Test Strip for Visual Detection of Cu2.

    Directory of Open Access Journals (Sweden)

    Yulong Wang

    Full Text Available A signal-amplified lateral flow test strip (SA-LFTS for the detection of Cu2+ in aqueous solution was constructed based on Cu+-catalyzed click chemistry and hybridization of single-stranded DNA (ssDNA. Alkyne and azide modified ssDNA acted as specific elements for Cu2+ recognition, and a chemical ligation product formed through Cu+-catalyzed alkyne-azide cycloaddition. Hybridization of ssDNA-labeled gold nanoparticles resulted in high sensitivity, and the output signal could be observed directly by the naked eye. Using the developed SA-LFTS under optimal conditions, Cu2+ could be detected rapidly with limit of detections of 5 nM and 4.2 nM by visual observation and quantitative analysis, respectively. The sensitivity (i.e. the visual limit of detection of the SA-LFTS was 80-times higher than that of traditional LFTS. The SA-LFTS was applied to the determination of Cu2+ in municipal water and river water samples with the results showing good recovery and accuracy. The developed test strip is promising for point-of-care applications and detection of Cu2+ in the field.

  3. Feasibility of the clinical dynamic visual acuity test in typically developing preschoolers.

    Science.gov (United States)

    Verbecque, Evi; De Belder, Niels; Marijnissen, Tessa; Vereeck, Luc; Van de Heyning, Paul; Hallemans, Ann

    2018-02-28

    To determine the feasibility of the dynamic visual acuity test (DVA) in children who are preschoolers. Thirty-three preschoolers [3 years old (n = 11), 4 years old (n = 6), 5 years old (n = 8), and 6 years old (n = 8)], performed a static visual acuity test (SVA), a passive horizontal DVA (hDVA) at 1 and 2 Hz, and a DVA on treadmill at three age-specific walking speeds (slow/medium/high). The DVA scores, the difference between SVA and hDVA, were used to determine false positive results. The SVA was performed by 31/33 children, the hDVA and DVA on treadmill at slow and medium speed by 27/33 and the DVA on treadmill at high speed by 25/33. Except for one 5 years old, all drop-outs were 3 years old. The hDVA at 2 Hz was administered in only six children because of difficulties with focusing on reading the symbols at this frequency. False positive results for the hDVA at 1 Hz were found in 3/27 children, all 3 years old, and 2/6 for the hDVA at 2 Hz. The DVA on treadmill seems useful for preschoolers from age 5, but this should be further investigated in children with underlying pathologies.

  4. Enzyme-Based Test Strips for Visual or Photographic Detection and Quantitation of Gaseous Sulfur Mustard.

    Science.gov (United States)

    Bidmanova, Sarka; Steiner, Mark-Steven; Stepan, Martin; Vymazalova, Kamila; Gruber, Michael A; Duerkop, Axel; Damborsky, Jiri; Prokop, Zbynek; Wolfbeis, Otto S

    2016-06-07

    Sulfur mustard is a chemical agent of high military and terroristic significance. No effective antidote exists, and sulfur mustard can be fairly easily produced in large quantity. Rapid field testing of sulfur mustard is highly desirable. Existing analytical devices for its detection are available but can suffer from low selectivity, laborious sample preparation, and/or the need for complex instrumentation. We describe a new kind of test strip for rapid detection of gaseous sulfur mustard that is based on its degradation by the enzyme haloalkane dehalogenase that is accompanied by a change of local pH. This change can be detected using pH indicators contained in the strips whose color changes from blue-green to yellow within 10 min. In addition to visual read-out, we also demonstrate quantitative reflectometric readout by using a conventional digital camera based on red-green-blue data acquisition. Organic haloalkanes, such as 1,2-dichloroethane, have a negligible interfering effect. The visual limit of detection is 20 μg/L, and the one for red-green-blue read-out is as low as 3 μg/L. The assays have good reproducibility ±6% and ±2% for interday assays and intraday assays, respectively. The strips can be stored for at least 6 months without loss of function. They are disposable and can be produced fairly rapidly and at low costs. Hence, they represent a promising tool for in-field detection of sulfur mustard.

  5. Signal-Amplified Lateral Flow Test Strip for Visual Detection of Cu2+

    Science.gov (United States)

    Xue, Juanjuan; Dong, Jinbo; Cai, Jia; Hua, Xiude; Wang, Minghua; Zhang, Cunzheng; Liu, Fengquan

    2017-01-01

    A signal-amplified lateral flow test strip (SA-LFTS) for the detection of Cu2+ in aqueous solution was constructed based on Cu+-catalyzed click chemistry and hybridization of single-stranded DNA (ssDNA). Alkyne and azide modified ssDNA acted as specific elements for Cu2+ recognition, and a chemical ligation product formed through Cu+-catalyzed alkyne–azide cycloaddition. Hybridization of ssDNA-labeled gold nanoparticles resulted in high sensitivity, and the output signal could be observed directly by the naked eye. Using the developed SA-LFTS under optimal conditions, Cu2+ could be detected rapidly with limit of detections of 5 nM and 4.2 nM by visual observation and quantitative analysis, respectively. The sensitivity (i.e. the visual limit of detection) of the SA-LFTS was 80-times higher than that of traditional LFTS. The SA-LFTS was applied to the determination of Cu2+ in municipal water and river water samples with the results showing good recovery and accuracy. The developed test strip is promising for point-of-care applications and detection of Cu2+ in the field. PMID:28072878

  6. Solid-state lighting for the International Space Station: Tests of visual performance and melatonin regulation

    Science.gov (United States)

    Brainard, George C.; Coyle, William; Ayers, Melissa; Kemp, John; Warfield, Benjamin; Maida, James; Bowen, Charles; Bernecker, Craig; Lockley, Steven W.; Hanifin, John P.

    2013-11-01

    The International Space Station (ISS) uses General Luminaire Assemblies (GLAs) that house fluorescent lamps for illuminating the astronauts' working and living environments. Solid-state light emitting diodes (LEDs) are attractive candidates for replacing the GLAs on the ISS. The advantages of LEDs over conventional fluorescent light sources include lower up-mass, power consumption and heat generation, as well as fewer toxic materials, greater resistance to damage and long lamp life. A prototype Solid-State Lighting Assembly (SSLA) was developed and successfully installed on the ISS. The broad aim of the ongoing work is to test light emitted by prototype SSLAs for supporting astronaut vision and assessing neuroendocrine, circadian, neurobehavioral and sleep effects. Three completed ground-based studies are presented here including experiments on visual performance, color discrimination, and acute plasma melatonin suppression in cohorts of healthy, human subjects under different SSLA light exposure conditions within a high-fidelity replica of the ISS Crew Quarters (CQ). All visual tests were done under indirect daylight at 201 lx, fluorescent room light at 531 lx and 4870 K SSLA light in the CQ at 1266 lx. Visual performance was assessed with numerical verification tests (NVT). NVT data show that there are no significant differences in score (F=0.73, p=0.48) or time (F=0.14, p=0.87) for subjects performing five contrast tests (10%-100%). Color discrimination was assessed with Farnsworth-Munsell 100 Hue tests (FM-100). The FM-100 data showed no significant differences (F=0.01, p=0.99) in color discrimination for indirect daylight, fluorescent room light and 4870 K SSLA light in the CQ. Plasma melatonin suppression data show that there are significant differences (F=29.61, p<0.0001) across the percent change scores of plasma melatonin for five corneal irradiances, ranging from 0 to 405 μW/cm2 of 4870 K SSLA light in the CQ (0-1270 lx). Risk factors for the health and

  7. Visual analysis and Schmidt rebound hammer test of Taj-ul-Masajid

    Directory of Open Access Journals (Sweden)

    A. Hussain

    2017-09-01

    Full Text Available Taj-ul-Masajid, literally, the crown among mosques is an embodiment of genius structural engineering located in the heart of Madhya Pradesh, Bhopal. A unique combination of the Mughal Architecture in complete stone masonry and modern day RCC work, it is a liaison between the past and the present of structural engineering. A wonder in its own right, the structure is often neglected by technicians and conservationalists alike, a satire on their ingenuity. Now, in a severely dilapidated condition, the structure is in pressing need of structural rehabilitation. The authors intend to perform in-situ Non-Destructive Testing & Evaluation (NDT&E of this structure and thereby suggest steps to better its present condition. As a first step, they’ve performed the visual analysis and Schmidt Rebound Hammer Test on the concrete portion of the structure which has been presented herein. The authors have also suggested a new approach for the verification of results obtained.

  8. [Does the Fragmented Images Test measure locally oriented visual processing in autism spectrum disorders?].

    Science.gov (United States)

    Scheurich, Armin; Fellgiebel, Andreas; Müller, Mattias J; Poustka, Fritz; Bölte, Sven

    2010-03-01

    The cognitive phenotype of autism spectrum disorders (ASD) is characterized among other things by local processing (weak central coherence). It was examined whether a test that measures identification of fragmented pictures (FBT) is able to seize this preference for local processing. The FBT performance of 15 patients with ASD, 16 with depression, 16 with schizophrenia and of 16 control subjects was compared. In addition, two tests well known to be sensitive to local processing were assessed, namely the Embedded Figures Test (EFT) and the Block Design Test (BDT). ASD patients demonstrated a preference for local processing. Difficulties in global processing, or more specifically in gestalt perception (FBT), were accompanied by good performance on the EFT and BDT as expected. Controlling for age and nonverbal intelligence (ANCOVA) reduced differences to trends. However, the calculation of difference scores (i.e., subtraction of FBT from EFT performance) resulted in significant differences between ASD and control groups even after controlling for of age and intelligence. The FBT is a suitable exploratory test of local visual processing in ASD. In particular, a difference criterion can be generated (FBT vs. EFT) that discriminates between ASD and clinical as well as healthy control groups.

  9. Effects of audio-visual aids on foreign language test anxiety, reading and listening comprehension, and retention in EFL learners.

    Science.gov (United States)

    Lee, Shu-Ping; Lee, Shin-Da; Liao, Yuan-Lin; Wang, An-Chi

    2015-04-01

    This study examined the effects of audio-visual aids on anxiety, comprehension test scores, and retention in reading and listening to short stories in English as a Foreign Language (EFL) classrooms. Reading and listening tests, general and test anxiety, and retention were measured in English-major college students in an experimental group with audio-visual aids (n=83) and a control group without audio-visual aids (n=94) with similar general English proficiency. Lower reading test anxiety, unchanged reading comprehension scores, and better reading short-term and long-term retention after four weeks were evident in the audiovisual group relative to the control group. In addition, lower listening test anxiety, higher listening comprehension scores, and unchanged short-term and long-term retention were found in the audiovisual group relative to the control group after the intervention. Audio-visual aids may help to reduce EFL learners' listening test anxiety and enhance their listening comprehension scores without facilitating retention of such materials. Although audio-visual aids did not increase reading comprehension scores, they helped reduce EFL learners' reading test anxiety and facilitated retention of reading materials.

  10. Biomedical Titanium alloy prostheses manufacturing by means of Superplastic and Incremental Forming processes

    Directory of Open Access Journals (Sweden)

    Piccininni Antonio

    2016-01-01

    Full Text Available The present work collects some results of the three-years Research Program “BioForming“, funded by the Italian Ministry of Education (MIUR and aimed to investigate the possibility of using flexible sheet forming processes, i.e. Super Plastic Forming (SPF and Single Point Incremental Forming (SPIF, for the manufacturing of patient-oriented titanium prostheses. The prosthetic implants used as case studies were from the skull; in particular, two different Ti alloys and geometries were considered: one to be produced in Ti-Gr23 by SPF and one to be produced in Ti-Gr2 by SPIF. Numerical simulations implementing material behaviours evaluated by characterization tests were conducted in order to design both the manufacturing processes. Subsequently, experimental tests were carried out implementing numerical results in terms of: (i gas pressure profile able to determine a constant (and optimal strain rate during the SPF process; (ii tool path able to avoid rupture during the SPIF process. Post forming characteristics of the prostheses in terms of thickness distributions were measured and compared to data from simulations for validation purposes. A good correlation between numerical and experimental thickness distributions has been obtained; in addition, the possibility of successfully adopting both the SPF and the SPIF processes for the manufacturing of prostheses has been demonstrated.

  11. Fabrication techniques for ocular prostheses--an overview.

    Science.gov (United States)

    Goiato, Marcelo Coelho; Bannwart, Lisiane Cristina; Haddad, Marcela Filié; dos Santos, Daniela Micheline; Pesqueira, Aldiéris Alves; Miyahara, Glauco Issamu

    2014-06-01

    The goals of treatment with ocular prostheses are to restore facial aesthetics and self-esteem to anophthalmic patients. Fabricated in acrylic resin, artificial eyes should be aesthetically pleasing, scratch-resistant, and adequately polished. Use of a prosthesis without such characteristics can lead to psychological damage, as well as infection and inflammation due to the accumulation of microorganisms and other substances on an irregularly shaped prosthesis. The present literature review describes the different techniques for fabricating ocular prostheses. Reproduction of the iris color and color stability are important factors that promote adequate aesthetics. The fabrication of an individual ocular prosthesis in acrylic resin provides satisfactory aesthetic results because the impression process establishes the defect contour. Additionally, the iris and sclera can be individually characterized. As the techniques, materials, and manufacturing methods for ocular prostheses continue to evolve, the aesthetics and functionality of prostheses will also improve.

  12. Effect of beverages and mouthwashes on the hardness of polymers used in intraoral prostheses.

    Science.gov (United States)

    Goiato, Marcelo Coelho; Dos Santos, Daniela Micheline; Andreotti, Agda Marobo; Nobrega, Adhara Smith; Moreno, Amalia; Haddad, Marcela Filié; Pesqueira, Aldiéris Alves

    2014-10-01

    The mechanical properties of acrylic resins used in intraoral prostheses may be altered by frequent exposure to liquids such as beverages and mouthwashes. This study aimed to evaluate the effect of thermocycling and liquid immersion on the hardness of four brands of acrylic resins commonly used in removable prostheses (Onda Cryl, QC-20, Clássico, Lucitone). For each brand of resin, seven specimens were immersed in each of six solutions (coffee, cola, red wine, Plax-Colgate, Listerine [LI], Oral B), and seven more were placed in artificial saliva (control). The hardness was tested using a microhardness tester before and after 5000 thermocycles and after 1, 3, 24, 48, and 96 hours of immersion. The results were analyzed using three-way repeated-measures ANOVA and Tukey's test (p hardness of the resins decreased following thermocycling and immersion in the solutions. Specimens immersed in cola and wine exhibited significant decreases in hardness after immersion for 96 hours, although the greatest significant decrease in hardness occurred in specimens immersed in LI. However, according to American Dental Association specification 12, the Knoop hardness of acrylic resins for intraoral prostheses should not be below 15. Thus, the median values of superficial hardness observed in most of the acrylic resins in this study are considered clinically acceptable. The microhardness of polymers used for intraoral prostheses decreases following thermocycling. Among specimens immersed in beverages, those immersed in cola or wine experienced the greatest decrease in microhardness. Immersion of acrylic resins in LI significantly decreased the microhardness in relation to the initial value. Among the resins assessed, QC-20 exhibited the lowest initial hardness. © 2014 by the American College of Prosthodontists.

  13. [The Visual Association Test to study episodic memory in clinical geriatric psychology].

    Science.gov (United States)

    Diesfeldt, Han; Prins, Marleen; Lauret, Gijs

    2018-04-01

    The Visual Association Test (VAT) is a brief learning task that consists of six line drawings of pairs of interacting objects (association cards). Subjects are asked to name or identify each object and later are presented with one object from the pair (the cue) and asked to name the other (the target). The VAT was administered in a consecutive sample of 174 psychogeriatric day care participants with mild to major neurocognitive disorder. Comparison of test performance with normative data from non-demented subjects revealed that 69% scored within the range of a major deficit (0-8 over two recall trials), 14% a minor, and 17% no deficit (9-10, and ≥10 respectively).VAT-scores correlated with another test of memory function, the Cognitive Screening Test (CST), based on the Short Portable Mental Status Questionnaire (r = 0.53). Tests of executive functioning (Expanded Mental Control Test, Category Fluency, Clock Drawing) did not add significantly to the explanation of variance in VAT-scores.Fifty-five participants (31.6%) were faced with initial problems in naming or identifying one or more objects on the cue cards or association cards. If necessary, naming was aided by the investigator. Initial difficulties in identifying cue objects were associated with lower VAT-scores, but this did not hold for difficulties in identifying target objects.A hierarchical multiple regression analysis was used to examine whether linear or quadratic trends best fitted VAT performance across the range of CST scores. The regression model revealed a linear but not a quadratic trend. The best fitting linear model implied that VAT scores differentiated between CST scores in the lower, as well as in the upper range, indicating the absence of floor and ceiling effects, respectively. Moreover, the VAT compares favourably to word list-learning tasks being more attractive in its presentation of interacting visual objects and cued recall based on incidental learning of the association

  14. Candida albicans in patients with oronasal communication and obturator prostheses

    OpenAIRE

    MATTOS, Beatriz Silva Câmara; SOUSA, Andréa Alves de; MAGALHÃES, Marina Helena C. G. de; ANDRÉ, Marcia; BRITO E DIAS, Reinaldo

    2009-01-01

    Patients using obturator prostheses often present denture-induced stomatitis. In order to detect the presence of oral Candida albicans in patients with oronasal communications and to evaluate the effectiveness of a topical antifungal treatment, cytological smears obtained from the buccal and palatal mucosa of 10 adult patients, and from the nasal acrylic surface of their obturator prostheses were examined. A therapeutic protocol comprising the use of oral nystatin (Mycostatin®) and prosthesis...

  15. A web-portal for interactive data exploration, visualization, and hypothesis testing.

    Science.gov (United States)

    Bartsch, Hauke; Thompson, Wesley K; Jernigan, Terry L; Dale, Anders M

    2014-01-01

    Clinical research studies generate data that need to be shared and statistically analyzed by their participating institutions. The distributed nature of research and the different domains involved present major challenges to data sharing, exploration, and visualization. The Data Portal infrastructure was developed to support ongoing research in the areas of neurocognition, imaging, and genetics. Researchers benefit from the integration of data sources across domains, the explicit representation of knowledge from domain experts, and user interfaces providing convenient access to project specific data resources and algorithms. The system provides an interactive approach to statistical analysis, data mining, and hypothesis testing over the lifetime of a study and fulfills a mandate of public sharing by integrating data sharing into a system built for active data exploration. The web-based platform removes barriers for research and supports the ongoing exploration of data.

  16. The Effect of Visual-Chunking-Representation Accommodation on Geometry Testing for Students with Math Disabilities

    Science.gov (United States)

    Zhang, Dake; Ding, Yi; Stegall, Joanna; Mo, Lei

    2012-01-01

    Students who struggle with learning mathematics often have difficulties with geometry problem solving, which requires strong visual imagery skills. These difficulties have been correlated with deficiencies in visual working memory. Cognitive psychology has shown that chunking of visual items accommodates students' working memory deficits. This…

  17. Method Matters: Systematic Effects of Testing Procedure on Visual Working Memory Sensitivity

    Science.gov (United States)

    Makovski, Tal; Watson, Leah M.; Koutstaal, Wilma; Jiang, Yuhong V.

    2010-01-01

    Visual working memory (WM) is traditionally considered a robust form of visual representation that survives changes in object motion, observer's position, and other visual transients. This article presents data that are inconsistent with the traditional view. We show that memory sensitivity is dramatically influenced by small variations in the…

  18. Testicular prostheses in children: Is earlier better?

    Science.gov (United States)

    Peycelon, M; Rossignol, G; Muller, C O; Carricaburu, E; Philippe-Chomette, P; Paye-Jaouen, A; El Ghoneimi, A

    2016-08-01

    The absence of a testis occurs for various reasons in children, but testicular prosthesis implantation in children is uncommon. The optimal time for prosthesis placement is still unclear, and its complication rate has been poorly studied in children. The aim of this study was to determine the risk factors of complications in cases of testicular prosthesis implantation in children. A monocentric, retrospective review was performed of children implanted with a testicular prosthesis between 2008 and 2014. All implantations were performed through an inguinal incision with a standardized procedure. Children were divided into two groups depending on the interval after orchiectomy: (A) early implantation (delay between surgeries prosthesis implantation at the mean age of 14.7 years (range 9-18) (A, 14.3; B, 14.6) with a mean delay of 36.1 months (A, 1.3; B, 80.3). Indications were mainly spermatic cord torsion (27%), bilateral anorchia (27%), and testicular atrophy after cryptorchidism surgery (19.2%). Complications (10.5%) included two cases of extrusion, one infection and one migration. Patient 1 had a history of acute lymphoblastic leukemia with testicle relapse 2 years after induction therapy. High-dose chemotherapy, total body irradiation and bilateral orchiectomies were performed, and bilateral prostheses were implanted 12 years after the end of chemotherapy. Complications happened 85 days after surgery. Patient 2 was followed-up for a proximal hypospadias. The tunica vaginalis flap, which was used during a redo urethroplasty, lead to testicular atrophy. Thirteen years after the last penile surgery, a testicular prosthesis was placed through an inguinal incision, and extrusion occurred 203 days after surgery. Bacterial cultures of the prostheses were sterile and histological review showed no sign of granuloma or graft rejection. The complication rate was significantly higher if the delay between the two surgeries exceeded 1 year (P = 0.01). Indications of

  19. Autism and attention deficit hyperactivity disorder: assessing attention and response control with the integrated visual and auditory continuous performance test.

    OpenAIRE

    Corbett, Blythe A; Constantine, Laura J

    2006-01-01

    Symptoms of attention deficit hyperactivity disorder (ADHD) have been widely reported in children with autism spectrum disorder (ASD). The current study investigated attention and response control in children with ASD, ADHD, and typical development using the Integrated Visual and Auditory Continuous Performance Test. Results indicate that many children with ASD show significant deficits in visual and auditory attention and greater deficits in impulsivity than children with ADHD or typical dev...

  20. Recognition versus Resolution: a Comparison of Visual Acuity Results Using Two Alternative Test Chart Optotype

    Science.gov (United States)

    Pointer, Jonathan S.

    2010-01-01

    Purpose To quantify the difference between recognition (letter) and resolution (Landolt) visual acuity (VA) in a group of normally sighted subjects. Is it reasonable to assume that the two acuity measures are clinically equivalent? Methods A pair of 6 m acuity test charts was produced: one comprised letters and the other Landolt broken rings. Construction of both charts conformed to the logMAR design format. Monocular VA was determined for the dominant eye of 300 screened and normally sighted optometric patients aged 16 to 40, each wearing an optical refractive (spectacle) correction. Results Letter acuity was superior to Landolt acuity (P≤0.0001). The mean paired acuity difference was -0.041 logMAR (standard deviation 0.034): the 95% limits of agreement were ±0.067 logMAR units or ±3.3 chart optotype. Repeatability was high and similar for each chart type (±2.1 and ±2.4 optotype for letter and Landolt, respectively). Gender, test sequence, and laterality of the dominant eye (left or right) were each non-statistically significant variables. Conclusions For normally sighted subjects wearing an optimal refractive correction, a bias was recorded in favour of recognition over resolution acuity: the clinical difference amounted to approximately 40% of one logMAR chart line, with similar high repeatability for either chart optotype. We conclude that the assumption of clinical equivalence between letter and Landolt acuity is reasonable under optimum test conditions.

  1. Gait in children with cerebral palsy : observer reliability of Physician Rating Scale and Edinburgh Visual Gait Analysis Interval Testing scale

    NARCIS (Netherlands)

    Maathuis, KGB; van der Schans, CP; van Iperen, A; Rietman, HS; Geertzen, JHB

    2005-01-01

    The aim of this study was to test the inter- and intra-observer reliability of the Physician Rating Scale (PRS) and the Edinburgh Visual Gait Analysis Interval Testing (GAIT) scale for use in children with cerebral palsy (CP). Both assessment scales are quantitative observational scales, evaluating

  2. A Pilot Study of a Test for Visual Recognition Memory in Adults with Moderate to Severe Intellectual Disability

    Science.gov (United States)

    Pyo, Geunyeong; Ala, Tom; Kyrouac, Gregory A.; Verhulst, Steven J.

    2010-01-01

    Objective assessment of memory functioning is an important part of evaluation for Dementia of Alzheimer Type (DAT). The revised Picture Recognition Memory Test (r-PRMT) is a test for visual recognition memory to assess memory functioning of persons with intellectual disabilities (ID), specifically targeting moderate to severe ID. A pilot study was…

  3. The Bender Visual Motor Gestalt Test: Correlations with WISC-R and Attainment Measures in a Clinic Sample.

    Science.gov (United States)

    Hamer, Ann

    1988-01-01

    Use of the Bender Visual Motor Gestalt Test in Australia was studied by comparing it with existing research, scores on the Wechsler Intelligence Scale for Children-Revised (WISC-R), and other attainment tests. Subjects were 142 children aged 7-11 years. The suitability of the instrument in Australia is discussed. (SLD)

  4. Visual Working Memory and Perception Speed of 3- to 6-Year-Old Children Tested with a Matrix Film Battery Test

    Science.gov (United States)

    Pittorf, Martin L.; Lehmann, Wolfgang; Huckauf, Anke

    2014-01-01

    In this study the visual working memory (VWM) and perception speed of 60 children between the ages of three and six years were tested with an age-based, easy-to-handle Matrix Film Battery Test (reliability R?=?0.71). It was thereby affirmed that the VWM is age dependent (correlation coefficient r?=?0.66***) as expected. Furthermore, a significant…

  5. Oral-Fluid Thiol-Detection Test Identifies Underlying Active Periodontal Disease Not Detected by the Visual Awake Examination.

    Science.gov (United States)

    Queck, Katherine E; Chapman, Angela; Herzog, Leslie J; Shell-Martin, Tamara; Burgess-Cassler, Anthony; McClure, George David

    2018-03-20

    Periodontal disease in dogs is highly prevalent but can only be accurately diagnosed by performing an anesthetized oral examination with periodontal probing and dental radiography. In this study, 114 dogs had a visual awake examination of the oral cavity and were administered an oral-fluid thiol-detection test prior to undergoing a a full-mouth anesthetized oral examination and digital dental radiographs. The results show the visual awake examination underestimated the presence and severity of active periodontal disease. The thiol-detection test was superior to the visual awake examination at detecting the presence and severity of active periodontal disease and was an indicator of progression toward alveolar bone loss. The thiol-detection test detected active periodontal disease at early stages of development, before any visual cues were present, indicating the need for intervention to prevent periodontal bone loss. Early detection is important because without intervention, dogs with gingivitis (active periodontal disease) progress to irreversible periodontal bone loss (stage 2+). As suggested in the current AAHA guidelines, a thiol-detection test administered in conjunction with the visual awake examination during routine wellness examinations facilitates veterinarian-client communication and mitigates under-diagnosis of periodontal disease and underutilization of dental services. The thiol-detection test can be used to monitor the periodontal health status of the conscious patient during follow-up examinations based on disease severity.

  6. Test-Retest Reliability and Minimal Detectable Change of the Test of Visual Perceptual Skills-Third Edition in Patients With Stroke.

    Science.gov (United States)

    Chiu, En-Chi; Wu, Wen-Chi; Chou, Chiung-Xia; Yu, Min-Yuan; Hung, Jen-Wen

    2016-11-01

    To examine the test-retest reliability, calculate minimal detectable change (MDC), and report internal consistency of the Test of Visual Perceptual Skills-Third Edition (TVPS-3) in patients with stroke. Repeated-measures design (at an interval of 2wk). Medical center. Patients (N=50) with chronic stroke who completed the TVPS-3. Not applicable. TVPS-3 that contains 7 subscales, namely, visual discrimination, visual memory, spatial relations, form constancy, sequential memory, visual figure-ground, and visual closure. The intraclass correlation coefficient value of the overall scale was .92 and those of the 7 subscales were .53 to .82. The MDC values of the overall scale and the subscales were 18.1 and 5.4 to 7.1, respectively. The MDC% value of the overall scale was 16.2% (30%), indicating substantial random measurement errors. The Cronbach α of the 7 subscales were .71 to .89, indicating good internal consistency. Our results showed that the overall scale of the TVPS-3 had satisfactory test-retest reliability. However, the subscales demonstrated insufficient test-retest reliability. Therefore, the subscales should be used cautiously to explain the test results over repeated assessments in patients with stroke. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  7. Development and Testing of Functionally Operative and Visually Appealing Remote Firing Room Displays and Applications

    Science.gov (United States)

    Quaranto, Kristy

    2014-01-01

    This internship provided an opportunity for an intern to work with NASA's Ground Support Equipment (GSE) for the Spaceport Command and Control System (SCCS) at Kennedy Space Center as a remote display developer, under NASA technical mentor Kurt Leucht. The main focus was on creating remote displays and applications for the hypergolic and high pressure helium subsystem team to help control the filling of the respective tanks. As a remote display and application developer for the GSE hypergolic and high pressure helium subsystem team the intern was responsible for creating and testing graphical remote displays and applications to be used in the Launch Control Center (LCC) on the Firing Room's computers. To become more familiar with the subsystem, the individual attended multiple project meetings and acquired their specific requirements regarding what needed to be included in the software. After receiving the requirements for the displays, the next step was to create displays that had both visual appeal and logical order using the Display Editor, on the Virtual Machine (VM). In doing so, all Compact Unique Identifiers (CUI), which are associated with specific components within the subsystem, were need to be included in each respective display for the system to run properly. Then, once the display was created it was to be tested to ensure that the display runs as intended by using the Test Driver, also found on the VM. This Test Driver is a specific application that checks to make sure all the CUIs in the display are running properly and returning the correct form of information. After creating and locally testing the display it needed to go through further testing and evaluation before deemed suitable for actual use. For the remote applications the intern was responsible for creating a project that focused on channelizing each component included in each display. The core of the application code was created by setting up spreadsheets and having an auto test generator

  8. Technical note: Validation of a chemical pregnancy test in dairy cows that uses whole blood, shortened incubation times, and visual readout.

    Science.gov (United States)

    Mayo, L M; Moore, S G; Poock, S E; Silvia, W J; Lucy, M C

    2016-09-01

    Chemical pregnancy testing is an alternative to traditional methods of pregnancy diagnosis (either manual palpation or ultrasound) in postpartum dairy cows and heifers. The objective was to validate a chemical pregnancy test that confers the advantages of using whole blood, rapid incubation times, and visual readout. Blood and milk samples were collected from Holstein dairy cows [n=320; 162±62 (mean ± SD) d in milk] on a confinement farm in northeast Missouri at 28 d after artificial insemination (AI). The samples were assayed for pregnancy-associated glycoproteins (PAG) by using a rapid visual test as well as traditional plasma- and milk-based tests. Transrectal ultrasonography diagnosis for pregnancy at 35 to 38 d after AI was the reference (gold) standard for all PAG tests. One hundred fifty-nine cows were diagnosed as pregnant by the reference standard (pregnancies per AI=49.7%). The tests were ELISA and either optical density (OD; measured with a microtiter plate reader; plasma, milk, and rapid visual tests) or visual readout (rapid visual test) were used to diagnose pregnancy. When OD was used, the percentage of pregnant cows classified correctly (sensitivity) for the plasma, milk, and rapid visual tests were 97±1, 96±2, and 95±1% (±SE), respectively. The sensitivity of the rapid visual test when assessed visually was 98±1%. The specificity (proportion of nonpregnant cows classified correctly) for the plasma, milk, and rapid visual was 94±2%, 94±2%, and 93±2% when an OD was used. When read visually, the specificity of the rapid visual test was lesser (85±3%) because some cows with faint visual signals yielded false positive diagnosis. The overall accuracy (proportion of pregnant and nonpregnant cows diagnosed correctly) was similar for all tests (plasma, milk, rapid visual OD, and rapid visual; 96±1, 95±1, 94±1, and 92±2%, respectively). In a second experiment, lactating Holstein cows (n=291) from 4 commercial confinement dairy farms in western

  9. Platelet thrombosis in cardiac-valve prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Dewanjee, M.K.

    1989-01-01

    The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day study in the dog model was similar (< 1% if injected In-111 platelets = 5 billion platelets). As the fibrous ingrowth covered the sewing ring, the thrombus formation decreased significantly. Only a small amount of thrombus was found on the leaflets at one month in both the dog and calf models. 38 refs., 9 figs., 5 tabs.

  10. Platelet thrombosis in cardiac-valve prostheses

    International Nuclear Information System (INIS)

    Dewanjee, M.K.

    1989-01-01

    The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day study in the dog model was similar (< 1% if injected In-111 platelets = 5 billion platelets). As the fibrous ingrowth covered the sewing ring, the thrombus formation decreased significantly. Only a small amount of thrombus was found on the leaflets at one month in both the dog and calf models. 38 refs., 9 figs., 5 tabs

  11. The impact of the luminance, size and location of LED billboards on drivers' visual performance-Laboratory tests.

    Science.gov (United States)

    Zalesinska, Malgorzata

    2018-02-28

    A proper visual performance by drivers can be ensured by, among else, a correct distribution of luminance in their field of view. At night, when the driver's sight is adapted to low luminance levels, high luminance level objects located near the road may be a source of glare, which is not only a nuisance, but it may also blind the driver. For many years, LED billboards (light-emitting diode billboards) have been installed near roads. Such billboards are usually large, have high luminance and show dynamically changing images. These parameters have a significant impact on the drivers' visual performance and, in turn, on road traffic safety. The study on the impact of the luminance, size and location of LED billboards on the drivers' visual performance was conducted on a volunteer group. Testing the impact of LED billboards on the visual performance of drivers in real-life conditions is very difficult. Therefore, the tests have been conducted in laboratory conditions, using a car driving simulator. The paper describes the testing procedure and tests results. The permissible luminance and areas of LED screens in two locations near the road, which significantly reduce the drivers' visual performance in municipal traffic at night, were determined by conducting an analysis of the results. Recommendations on the permissible luminance and areas of LED billboards were formulated. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. VATA-L: visual-analogue test assessing anosognosia for language impairment.

    Science.gov (United States)

    Cocchini, Gianna; Gregg, Nicola; Beschin, Nicoletta; Dean, Michael; Della Sala, Sergio

    2010-11-01

    Lack of awareness (anosognosia) for one's own language impairments has rarely been investigated, despite hampering language rehabilitation. Assessment of anosognosia by means of self-report is particularly complex, as a patient's language difficulties may seriously prevent or bias the assessment. Other methods, such as measures of self-correction and error detection, have provided valuable information, although they are an indirect form of assessment of anosognosia and are not exempt from methodological criticisms. In this study we report on a new tool, the VATA-L (Visual-Analogue Test for Anosognosia for Language impairment), geared at assessing explicit anosognosia for aphasia. The VATA-L compares the patient's self-evaluation with caregivers' evaluations of the patient's verbal communication abilities in a series of common situations. By means of non-verbal support and a system of check questions, this test minimizes some of the methodological limitations of existing diagnostic tools (e.g., structured interviews), enhancing reliability, and enabling assessment of patients with aphasia. Finally, normative data provided in the study allow a clearer interpretation of the patient's performance and facilitate assessment of anosognosia.

  13. VATA-m: Visual-Analogue Test assessing Anosognosia for motor impairment.

    Science.gov (United States)

    Della Sala, S; Cocchini, G; Beschin, N; Cameron, A

    2009-04-01

    There has been a growing interest in anosognosia in both clinical and research domains, yet relatively little attention has been paid to methods for evaluating it. Usually, the presence and severity of anosognosia is assessed by means of structured interviews or questionnaires. Both interviews and questionnaires can provide valuable information, but they rely heavily on self-evaluation and language, and are therefore prone to bias and pose more difficulty in the assessment of aphasic patients. The aim of this study was to develop a new tool, the VATA-m (Visual-Analogue Test for Anosognosia for motor impairment), to assess explicit anosognosia for motor impairments. The VATA-m is a questionnaire that compares a patient's self-evaluation with a caregivers' evaluation of the patient's abilities on a series of motor tasks. In addition, the test overcomes some of the limitations of the existing structured interviews and questionnaires, by enhancing reliability, improving data interpretation and diagnosis, and enabling assessment of patients with aphasia.

  14. Testing learners' attitudes - visual components of texts as bridges or barriers to learning

    Directory of Open Access Journals (Sweden)

    Anthonissen, Christine

    2003-12-01

    Full Text Available This article considers how visual images in texts may enhance or inhibit language learning. It draws on Kress and Van Leeuwen’s (1996 work on the grammar of visual design, recognising that visual images form part of a powerful semiotic system that carries representational and connotative meanings in a manner comparable to that of words, sentences and larger textual units. It takes note of the ways in which new technologies have introduced more visual material in printed texts than was available before. And it reports on an investigation into the specific responses of Grade 10 learners to visuals of people featuring different characteristics. Eventually we need to develop learning materials where visuals facilitate and motivate language learning, and simultaneously facilitate the development of socially responsible values.

  15. Attentional and visual demands for sprint performance in non-fatigued and fatigued conditions: reliability of a repeated sprint test

    Directory of Open Access Journals (Sweden)

    Diercks Ron L

    2010-05-01

    Full Text Available Abstract Background Physical performance measures are widely used to assess physical function, providing information about physiological and biomechanical aspects of motor performance. However they do not provide insight into the attentional and visual demands for motor performance. A figure-of-eight sprint test was therefore developed to measure the attentional and visual demands for repeated-sprint performance. The aims of the study were: 1 to assess test-retest reliability of the figure-of-eight sprint test, and 2 to study the attentional and visual demands for sprint performance in a non-fatigued and fatigued condition. Methods Twenty-seven healthy athletes were included in the study. To determine test-retest reliability, a subgroup of 19 athletes performed the figure-of-eight sprint test twice. The figure-of-eight sprint test consisted of nine 30-second sprints. The sprint test consisted of three test parts: sprinting without any restriction, with an attention-demanding task, and with restricted vision. Increases in sprint times with the attention-demanding task or restricted vision are reflective of the attentional and visual demands for sprinting. Intraclass correlation coefficients (ICCs and mean difference between test and retest with 95% confidence limits (CL were used to assess test-retest reliability. Repeated-measures ANOVA were used for comparisons between the sprint times and fatigue measurements of the test parts in both a non-fatigued and fatigued condition. Results The figure-of-eight sprint test showed good test-retest reliability, with ICCs ranging from 0.75 to 0.94 (95% CL: 0.40-0.98. Zero lay within the 95% CL of the mean differences, indicating that no bias existed between sprint performance at test and retest. Sprint times during the test parts with attention-demanding task (P = 0.01 and restricted vision (P Conclusions High ICCs and the absence of systematic variation indicate good test-retest reliability of the figure

  16. Handheld shape discrimination hyperacuity test on a mobile device for remote monitoring of visual function in maculopathy.

    Science.gov (United States)

    Wang, Yi-Zhong; He, Yu-Guang; Mitzel, Gina; Zhang, Song; Bartlett, Mike

    2013-08-13

    Frequency monitoring of age-related macular degeneration (AMD) and diabetic retinopathy (DR) is crucial for timely intervention. This study evaluated a handheld shape discrimination hyperacuity (hSDH) test iPhone app designed for visual function self-monitoring in patients with AMD and DR. One hundred subjects (27 visually normal, 37 with AMD, and 36 with DR) were included based on clinical documentation and visual acuity of 20/100 or better. The hSDH test was implemented on the iOS platform. A cross-sectional study was conducted to compare the hSDH test with a previously established desktop SDH (dSDH) test and to assess the effect of disease severity on the hSDH test. A user survey was also conducted to assess the usability of the hSDH test on the mobile device. The hSDH test and dSDH test were highly correlated (r = 0.88, P mobile device is comparable to PC-based testing methods. As a mobile app, it is intuitive to use, readily accessible, and sensitive to the severity of maculopathy. It has the potential to provide patients having maculopathy with a new tool to monitor their vision at home.

  17. An assessment of the iPad as a testing platform for distance visual acuity in adults

    Science.gov (United States)

    Black, J M; Jacobs, R J; Phillips, G; Chen, L; Tan, E; Tran, A; Thompson, B

    2013-01-01

    Objectives Visual acuity is a common measurement in general practice, and the advent of new technology such as tablet computers offers a change in the way in which these tests are delivered. The aim of this study was to assess whether measurements of distance visual acuity using LogMAR letter charts displayed on an iPad tablet computer were in agreement with standard clinical tests of visual acuity in adults with normal vision. Design Blinded, diagnostic test study. Setting Single centre (University) in Auckland, New Zealand. Participants University staff and students (n=85). Participants were required to have visual acuity better than 6/60 and wear habitual refractive correction during testing. Participants were excluded if there was any history of ocular pathology. Primary and secondary outcome measures Visual acuity measured under a number of conditions. Results The iPad tablet with its glossy screen was highly susceptible to glare resulting in acuity measurements that were significantly poorer (approximately 2 LogMAR lines) than those made using an ETDRS chart and a standard computerised testing system (n=56). However, fitting the iPad with an antiglare screen and positioning the device away from sources creating reflected (veiling) glare resulted in acuity measurements that were equivalent those made using gold standard charts (n=29). Conclusions Tablet computers are an attractive option for visual acuity measurement due to portability, the ability to randomise letters, automated scoring of acuity and the ability to select from a range of charts. However, these devices are only suitable for use in situations where sources of glare can be eliminated. PMID:23794568

  18. Retroca valvular Replacement of heart valves prostheses

    Directory of Open Access Journals (Sweden)

    Pablo M. A Pomerantzeff

    1987-12-01

    replacement, at our Institution. These patients received a total of 157 prostheses and 4 had their Starr-Edwards valve ball replaced due to ball variance. Six patients were submitted to a third valvular replacement in the mitral position, withouth deaths. Nine patients had a third valvular replacement in the aortic position with 1 death in the immediate postoperative period. Rupture or calcification of the dura mater leaflets were the main reason for the indication of prosthetic replacement. In the mitral position 41 patients presented rupture of the leaflets and 19 showed calcification. In the aortic position 32 bioprostheses underwent rupture and 12, calcification. Bio-prostheses were utilized in the majority of cases of replace the dysfunctioning prostheses. Porcine bioprostheses were implanted in 63 cases and bovine pericardial bioprostheses, in 35. Immediate mortality was 8.3% (12 patients; low cardiac output was the main cause of death. The most frequent immediate complications were low cardiac output, arrhythmias and bleeding. In the preoperative period 90% of the patients were in functional classes III and IV (NYHA. After the replacement, 89% of the aortics and 82% of the mitral were in functional classes I an II.

  19. The Role of Visual and Auditory Stimuli in Continuous Performance Tests: Differential Effects on Children With ADHD.

    Science.gov (United States)

    Simões, Eunice N; Carvalho, Ana L Novais; Schmidt, Sergio L

    2018-04-01

    Continuous performance tests (CPTs) usually utilize visual stimuli. A previous investigation showed that inattention is partially independent of modality, but response inhibition is modality-specific. Here we aimed to compare performance on visual and auditory CPTs in ADHD and in healthy controls. The sample consisted of 160 elementary and high school students (43 ADHD, 117 controls). For each sensory modality, five variables were extracted: commission errors (CEs) and omission errors (OEs), reaction time (RT), variability of reaction time (VRT), and coefficient of variability (CofV = VRT / RT). The ADHD group exhibited higher rates for all test variables. The discriminant analysis indicated that auditory OE was the most reliable variable for discriminating between groups, followed by visual CE, auditory CE, and auditory CofV. Discriminant equation classified ADHD with 76.3% accuracy. Auditory parameters in the inattention domain (OE and VRT) can discriminate ADHD from controls. For the hyperactive/impulsive domain (CE), the two modalities are equally important.

  20. Visual attention to repeated print advertising : A test of scanpath theory

    NARCIS (Netherlands)

    Pieters, F.G.M.; Rosbergen, E.; Wedel, M.

    1999-01-01

    The authors examine consumers' visual attention during repeated exposures to print advertisements using eye-tracking methodology. The authors propose a statistical model comprising submodels for two key measures of visual attention to elements of the advertisement: attention duration and inter- and

  1. The influence of visual stimulus properties on test performance in a nonsymbolic comparison task

    NARCIS (Netherlands)

    Slot, Esther

    2014-01-01

    The validity of nonsymbolic comparison tasks has been a point of discussion (De Smedt et al., 2013). It has been suggested that visual parameters might influence the relationship between approximate number system (ANS) and math. Most researchers have therefore attempted to control for visual

  2. Cobalt release and complications resulting from the use of dental prostheses

    DEFF Research Database (Denmark)

    Al-Imam, Hiba; Benetti, Ana R.; Özhayat, Esben B.

    2016-01-01

    of the functional prostheses released cobalt, whereas this was observed in 24 of 32 non-functional prostheses. None of the patients had contact allergy to cobalt. Of the 66 patients, 11 showed signs of inflammation of the oral mucosa, 2 had oral candidiasis, 16 had ill-fitting prostheses, and all had insufficient...... oral hygiene. CONCLUSIONS: Dental prostheses released cobalt during the fabrication stages, but not 1-5 years after insertion. No allergic reactions were observed. Signs of inflammation were related to candidiasis, insufficient oral hygiene, and ill-fitting prostheses.......) allergic reactions to components of dental prostheses, and (iii) to investigate the oral mucosa for inflammation 1-5 years after insertion of the prostheses. METHOD: Clinical oral examination was conducted in 66 patients with 84 dental prostheses. Cobalt release from 84 functional (used) and 32 non...

  3. The Relationship between Computer and Internet Use and Performance on Standardized Tests by Secondary School Students with Visual Impairments

    Science.gov (United States)

    Zhou, Li; Griffin-Shirley, Nora; Kelley, Pat; Banda, Devender R.; Lan, William Y.; Parker, Amy T.; Smith, Derrick W.

    2012-01-01

    Introduction: The study presented here explored the relationship between computer and Internet use and the performance on standardized tests by secondary school students with visual impairments. Methods: With data retrieved from the first three waves (2001-05) of the National Longitudinal Transition Study-2, the correlational study focused on…

  4. A computer-assisted test for the electrophysiological and psychophysical measurement of dynamic visual function based on motion contrast.

    Science.gov (United States)

    Wist, E R; Ehrenstein, W H; Schrauf, M; Schraus, M

    1998-03-13

    A new test is described that allows for electrophysiological and psychophysical measurement of visual function based on motion contrast. In a computer-generated random-dot display, completely camouflaged Landolt rings become visible only when dots within the target area are moved briefly while those of the background remain stationary. Thus, detection of contours and the location of the gap in the ring rely on motion contrast (form-from-motion) instead of luminance contrast. A standard version of this test has been used to assess visual performance in relation to age, in screening professional groups (truck drivers) and in clinical groups (glaucoma patients). Aside from this standard version, the computer program easily allows for various modifications. These include the option of a synchronizing trigger signal to allow for recording of time-locked motion-onset visual-evoked responses, the reversal of target and background motion, and the displacement of random-dot targets across stationary backgrounds. In all instances, task difficulty is manipulated by changing the percentage of moving dots within the target (or background). The present test offers a short, convenient method to probe dynamic visual functions relying on surprathreshold motion-contrast stimuli and complements other routine tests of form, contrast, depth, and color vision.

  5. The Role of Long-Term Memory in a Test of Visual Working Memory: Proactive Facilitation but No Proactive Interference

    Science.gov (United States)

    Oberauer, Klaus; Awh, Edward; Sutterer, David W.

    2017-01-01

    We report 4 experiments examining whether associations in visual working memory are subject to proactive interference from long-term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of 3…

  6. Implant-retained craniofacial prostheses for facial defects

    Science.gov (United States)

    Federspil, Philipp A.

    2012-01-01

    Craniofacial prostheses, also known as epistheses, are artificial substitutes for facial defects. The breakthrough for rehabilitation of facial defects with implant-retained prostheses came with the development of the modern silicones and bone anchorage. Following the discovery of the osseointegration of titanium in the 1950s, dental implants have been made of titanium in the 1960s. In 1977, the first extraoral titanium implant was inserted in a patient. Later, various solitary extraoral implant systems were developed. Grouped implant systems have also been developed which may be placed more reliably in areas with low bone presentation, as in the nasal and orbital region, or the ideally pneumatised mastoid process. Today, even large facial prostheses may be securely retained. The classical atraumatic surgical technique has remained an unchanged prerequisite for successful implantation of any system. This review outlines the basic principles of osseointegration as well as the main features of extraoral implantology. PMID:22073096

  7. CAD/CAM generated all-ceramic primary telescopic prostheses.

    Science.gov (United States)

    Kurbad, A; Ganz, S; Kurbad, S

    2012-01-01

    Computer-aided design and manufacturing (CAD/CAM) systems have proven effective not only for the manufacture of crown and bridge frameworks, inlays, onlays and veneers, but also for the generation of all-ceramic primary telescopic prostheses in more than 10 years of use in dental technology. The new InLab 4.0 software generation makes it possible to design and mill primary telescopic prostheses with CAD/CAM technology. The computer-generated raw crowns for these restorations require very little manual adaptation. The secondary crowns are manufactured by electroforming and bonded onto the tertiary structure or framework.

  8. Concordance of visual and manipulative responsiveness to novel and familiar stimuli: a function of test procedures or of prior experience?

    Science.gov (United States)

    Rubenstein, J

    1976-12-01

    Concordance of differential visual and manipulative responsiveness to novel stimuli at 6 months of age was found when differential attractiveness and familiarity of the stimuli were controlled. This finding corroborates the findings of an earlier study in which the same object was used as the familiarization object for all subjects. The data indicate that concordance at 6 months of age is not an artifact of the test procedure. A hypothesis suggested by the comparison of these findings with others in the literature is that the opportunity to manipulate a wide variety of objects in the natural environment may contribute to the concordance of visual and manipulative responsiveness to novel stimuli at this age.

  9. Fixed and mobile-bearing total ankle prostheses: Effect on tibial bone strain.

    Science.gov (United States)

    Terrier, Alexandre; Fernandes, Caroline Sieger; Guillemin, Maïka; Crevoisier, Xavier

    2017-10-01

    Total ankle replacement is associated to a high revision rate. To improve implant survival, the potential advantage of prostheses with fixed bearing compared to mobile bearing is unclear. The objective of this study was to test the hypothesis that fixed and mobile bearing prostheses are associated with different biomechanical quantities typically associated to implant failure. With a validated finite element model, we compared three cases: a prosthesis with a fixed bearing, a prosthesis with a mobile bearing in a centered position, and a prosthesis with mobile bearing in an eccentric position. Both prostheses were obtained from the same manufacturer. They were tested on seven tibias with maximum axial compression force during walking. We tested the hypothesis that there was a difference of bone strain, bone-implant interfacial stress, and bone support between the three cases. We also evaluated, for the three cases, the correlations between bone support, bone strain and bone-implant interfacial stress. There were no statistically significant differences between the three cases. Overall, bone support was mainly trabecular, and less effective in the posterior side. Bone strain and bone-implant interfacial stress were strongly correlated to bone support. Even if slight differences are observed between fixed and mobile bearing, it is not enough to put forward the superiority of one of these implants regarding their reaction to axial compression. When associated to the published clinical results, our study provides no argument to warn surgeons against the use of two-components fixed bearing implants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Radio tuning effects on visual and driving performance measures : simulator and test track studies.

    Science.gov (United States)

    2013-05-01

    Existing driver distraction guidelines for visual-manual device interface operation specify traditional : manual radio tuning as a reference task. This project evaluated the radio tuning reference task through two activities. : The first activity con...

  11. Using virtual reality to test the regularity priors used by the human visual system

    Science.gov (United States)

    Palmer, Eric; Kwon, TaeKyu; Pizlo, Zygmunt

    2017-09-01

    Virtual reality applications provide an opportunity to test human vision in well-controlled scenarios that would be difficult to generate in real physical spaces. This paper presents a study intended to evaluate the importance of the regularity priors used by the human visual system. Using a CAVE simulation, subjects viewed virtual objects in a variety of experimental manipulations. In the first experiment, the subject was asked to count the objects in a scene that was viewed either right-side-up or upside-down for 4 seconds. The subject counted more accurately in the right-side-up condition regardless of the presence of binocular disparity or color. In the second experiment, the subject was asked to reconstruct the scene from a different viewpoint. Reconstructions were accurate, but the position and orientation error was twice as high when the scene was rotated by 45°, compared to 22.5°. Similarly to the first experiment, there was little difference between monocular and binocular viewing. In the third experiment, the subject was asked to adjust the position of one object to match the depth extent to the frontal extent among three objects. Performance was best with symmetrical objects and became poorer with asymmetrical objects and poorest with only small circular markers on the floor. Finally, in the fourth experiment, we demonstrated reliable performance in monocular and binocular recovery of 3D shapes of objects standing naturally on the simulated horizontal floor. Based on these results, we conclude that gravity, horizontal ground, and symmetry priors play an important role in veridical perception of scenes.

  12. Alzheimer's disease in the human eye. Clinical tests that identify ocular and visual information processing deficit as biomarkers.

    Science.gov (United States)

    Chang, Lily Y L; Lowe, Jennifer; Ardiles, Alvaro; Lim, Julie; Grey, Angus C; Robertson, Ken; Danesh-Meyer, Helen; Palacios, Adrian G; Acosta, Monica L

    2014-03-01

    Alzheimer's disease (AD) is the most common form of dementia with progressive deterioration of memory and cognition. Complaints related to vision are common among AD patients. Several changes in the retina, lens, and in the vasculature have been noted in the AD eye that may be the cause of visual symptoms experienced by the AD patient. Anatomical changes have been detected within the eye before signs of cognitive impairment and memory loss are apparent. Unlike the brain, the eye is a unique organ that can be visualized noninvasively at the cellular level because of its transparent nature, which allows for inexpensive testing of biomarkers in a clinical setting. In this review, we have searched for candidate biomarkers that could enable diagnosis of AD, covering ocular neurodegeneration associated with functional tests. We explore the evidence that suggests that inexpensive, noninvasive clinical tests could be used to detect AD ocular biomarkers. Copyright © 2014 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  13. Testing a key assumption in animal communication: between-individual variation in female visual systems alters perception of male signals.

    Science.gov (United States)

    Ronald, Kelly L; Ensminger, Amanda L; Shawkey, Matthew D; Lucas, Jeffrey R; Fernández-Juricic, Esteban

    2017-12-15

    Variation in male signal production has been extensively studied because of its relevance to animal communication and sexual selection. Although we now know much about the mechanisms that can lead to variation between males in the properties of their signals, there is still a general assumption that there is little variation in terms of how females process these male signals. Variation between females in signal processing may lead to variation between females in how they rank individual males, meaning that one single signal may not be universally attractive to all females. We tested this assumption in a group of female wild-caught brown-headed cowbirds ( Molothrus ater ), a species that uses a male visual signal (e.g. a wingspread display) to make its mate-choice decisions. We found that females varied in two key parameters of their visual sensory systems related to chromatic and achromatic vision: cone densities (both total and proportions) and cone oil droplet absorbance. Using visual chromatic and achromatic contrast modeling, we then found that this between-individual variation in visual physiology leads to significant between-individual differences in how females perceive chromatic and achromatic male signals. These differences may lead to variation in female preferences for male visual signals, which would provide a potential mechanism for explaining individual differences in mate-choice behavior. © 2017. Published by The Company of Biologists Ltd.

  14. Predictive value of background experiences and visual spatial ability testing on laparoscopic baseline performance among residents entering postgraduate surgical training.

    Science.gov (United States)

    Louridas, Marisa; Quinn, Lauren E; Grantcharov, Teodor P

    2016-03-01

    Emerging evidence suggests that despite dedicated practice, not all surgical trainees have the ability to reach technical competency in minimally invasive techniques. While selecting residents that have the ability to reach technical competence is important, evidence to guide the incorporation of technical ability into selection processes is limited. Therefore, the purpose of the present study was to evaluate whether background experiences and 2D-3D visual spatial test results are predictive of baseline laparoscopic skill for the novice surgical trainee. First-year residents were studied. Demographic data and background surgical and non-surgical experiences were obtained using a questionnaire. Visual spatial ability was evaluated using the PicSOr, cube comparison (CC) and card rotation (CR) tests. Technical skill was assessed using the camera navigation (LCN) task and laparoscopic circle cut (LCC) task. Resident performance on these technical tasks was compared and correlated with the questionnaire and visual spatial findings. Previous experience in observing laparoscopic procedures was associated with significantly better LCN performance, and experience in navigating the laparoscopic camera was associated with significantly better LCC task results. Residents who scored higher on the CC test demonstrated a more accurate LCN path length score (r s(PL) = -0.36, p = 0.03) and angle path (r s(AP) = -0.426, p = 0.01) score when completing the LCN task. No other significant correlations were found between the visual spatial tests (PicSOr, CC or CR) and LCC performance. While identifying selection tests for incoming surgical trainees that predict technical skill performance is appealing, the surrogate markers evaluated correlate with specific metrics of surgical performance related to a single task but do not appear to reliably predict technical performance of different laparoscopic tasks. Predicting the acquisition of technical skills will require the development

  15. Prosthesis use in adult acquired major upper-limb amputees: patterns of wear, prosthetic skills and the actual use of prostheses in activities of daily life.

    Science.gov (United States)

    Østlie, Kristin; Lesjø, Ingrid Marie; Franklin, Rosemary Joy; Garfelt, Beate; Skjeldal, Ola Hunsbeth; Magnus, Per

    2012-11-01

    To describe patterns of prosthesis wear and perceived prosthetic usefulness in adult acquired upper-limb amputees (ULAs). To describe prosthetic skills in activities of daily life (ADL) and the actual use of prostheses in the performance of ADL tasks. To estimate the influence of prosthetic skills on actual prosthesis use and the influence of background factors on prosthetic skills and actual prosthesis use. Cross-sectional study analysing population-based questionnaire data (n = 224) and data from interviews and clinical testing in a referred/convenience sample of prosthesis-wearing ULAs (n = 50). Effects were analysed using linear regression. 80.8% wore prostheses. 90.3% reported their most worn prosthesis as useful. Prosthetic usefulness profiles varied with prosthetic type. Despite demonstrating good prosthetic skills, the amputees reported actual prosthesis use in only about half of the ADL tasks performed in everyday life. In unilateral amputees, increased actual use was associated with sufficient prosthetic training and with the use of myoelectric vs cosmetic prostheses, regardless of amputation level. Prosthetic skills did not affect actual prosthesis use. No background factors showed significant effect on prosthetic skills. Most major ULAs wear prostheses. Individualised prosthetic training and fitting of myoelectric rather than passive prostheses may increase actual prosthesis use in ADL.

  16. A computer-based biomechanical analysis of the three-dimensional motion of cementless hip prostheses.

    Science.gov (United States)

    Gilbert, J L; Bloomfeld, R S; Lautenschlager, E P; Wixson, R L

    1992-04-01

    A computer-based mathematical technique was developed to measure and completely describe the migration and micromotion of a femoral hip prosthesis relative to the femur. This technique utilized the mechanics of rigid-body motion analysis and apparatus of seven linear displacement transducers to measure and describe the complete three-dimensional motion of the prosthesis during cyclic loading. Computer acquisition of the data and custom analysis software allowed one to calculate the magnitude and direction of the motion of any point of interest on the prostheses from information about the motion of two points on the device. The data were also used to replay the tests using a computer animation technique, which allowed a magnified view of the three-dimensional motion of the prosthesis. This paper describes the mathematical development of the rigid-body motion analysis, the experimental method and apparatus for data collection, the technique used to animate the motion, the sources of error and the effect of the assumptions (rigid bodies) on the results. Selected results of individual test runs of uncemented and cemented prostheses are presented to demonstrate the efficacy of the method. The combined effect of the vibration and electrical noise resulted in a resolution of the system of about 3-5 microns motion for each transducer. Deformation effects appear to contribute about 3-15 microns to the measurement error. This measurement and analysis technique is a very sensitive and powerful means of assessing the effects of different design parameters on the migration and micromotion of total joint prostheses and can be applied to any other case (knee, dental implant) where three-dimensional relative motion between two bodies is important.

  17. How do the outcomes of the DEKA Arm compare to conventional prostheses?

    Science.gov (United States)

    Resnik, Linda J; Borgia, Matthew L; Acluche, Frantzy; Cancio, Jill M; Latlief, Gail; Sasson, Nicole

    2018-01-01

    Objectives were to 1) compare self-reported function, dexterity, activity performance, quality of life and community integration of the DEKA Arm to conventional prostheses; and 2) examine differences in outcomes by conventional prosthesis type, terminal device type and by DEKA Arm configuration level. This was a two-part study; Part A consisted of in-laboratory training. Part B consisted of home use. Study participants were 23 prosthesis users (mean age = 45 ± 16; 87% male) who completed Part A, and 15 (mean age = 45 ± 18; 87% male) who completed Parts A and B. Outcomes including self-report and performance measures, were collected at Baseline using participants' personal prostheses and at the End of Parts A and B. Scores were compared using paired t-tests. Wilcoxon signed-rank tests were used to compare outcomes for the full sample, and for the sample stratified by device and terminal device type. Analysis of outcomes by configuration level was performed graphically. At the End of Part A activity performance using the DEKA Arm and conventional prosthesis was equivalent, but slower with the DEKA Arm. After Part B, performance using the DEKA Arm surpassed conventional prosthesis scores, and speed of activity completion was equivalent. Participants reported using the DEKA Arm to perform more activities, had less perceived disability, and less difficulty in activities at the End of A and B as compared to Baseline. No differences were observed in dexterity, prosthetic skill, spontaneity, pain, community integration or quality of life. Comparisons stratified by device type revealed similar patterns. Graphic comparisons revealed variations by configuration level. Participants using the DEKA Arm had less perceived disability and more engagement of the prosthesis in everyday tasks, although activity performance was slower. After home use experience, activity performance was improved and activity speed equivalent to using conventional prostheses.

  18. In vitro evaluation of failure loads of nonmetal cantilevered resin-bonded fixed dental prostheses.

    Science.gov (United States)

    van Dalen, Andy; Feilzer, Albert J; Kleverlaan, Cornelis J

    2008-12-01

    To evaluate in vitro the influence of fiber reinforcement on the failure loads of resin composite beams, simulating cantilevered two-unit resin-bonded fixed dental prostheses, and compare the results with similarly obtained failure loads of ZrO2 and CoCr beams of a comparable design. Peel tests were performed using resin composite, fiber-reinforced resin composite, and zirconia beams, simulating two-unit cantilevered resin-bonded fixed dental prostheses, luted with Panavia F2.0 onto flat-ground buccal surfaces of bovine mandibular incisors. The recorded failure loads were compared with those of CoCr beams of a similar size and design from earlier research. Finite element analysis revealed the stress concentrations within the cement layers at failure. The failure loads (N) of the peel tests, depending on the beam type and including the type of failure, were statistically analyzed. The highest failure values were obtained with the fiber-reinforced resin composite beams, which were luted with the exposed fibers directly on the bovine enamel. Finite element analysis showed that peak stress locations depend on the beam type and facilitate the explanation of the different failure modes. Fiber-reinforcement of simulated two-unit cantilevered resin composite resin-bonded fixed dental prostheses does not necessarily lead to higher failure loads. This study identified significant differences in peel failure loads between identical specimens, depending on whether or not the fiber reinforcement was exposed on the luting surface. Further research needs to be carried out regarding the combination of resin composite and fiber reinforcement.

  19. How do the outcomes of the DEKA Arm compare to conventional prostheses?

    Directory of Open Access Journals (Sweden)

    Linda J Resnik

    Full Text Available Objectives were to 1 compare self-reported function, dexterity, activity performance, quality of life and community integration of the DEKA Arm to conventional prostheses; and 2 examine differences in outcomes by conventional prosthesis type, terminal device type and by DEKA Arm configuration level.This was a two-part study; Part A consisted of in-laboratory training. Part B consisted of home use. Study participants were 23 prosthesis users (mean age = 45 ± 16; 87% male who completed Part A, and 15 (mean age = 45 ± 18; 87% male who completed Parts A and B. Outcomes including self-report and performance measures, were collected at Baseline using participants' personal prostheses and at the End of Parts A and B. Scores were compared using paired t-tests. Wilcoxon signed-rank tests were used to compare outcomes for the full sample, and for the sample stratified by device and terminal device type. Analysis of outcomes by configuration level was performed graphically.At the End of Part A activity performance using the DEKA Arm and conventional prosthesis was equivalent, but slower with the DEKA Arm. After Part B, performance using the DEKA Arm surpassed conventional prosthesis scores, and speed of activity completion was equivalent. Participants reported using the DEKA Arm to perform more activities, had less perceived disability, and less difficulty in activities at the End of A and B as compared to Baseline. No differences were observed in dexterity, prosthetic skill, spontaneity, pain, community integration or quality of life. Comparisons stratified by device type revealed similar patterns. Graphic comparisons revealed variations by configuration level.Participants using the DEKA Arm had less perceived disability and more engagement of the prosthesis in everyday tasks, although activity performance was slower. After home use experience, activity performance was improved and activity speed equivalent to using conventional prostheses.

  20. DLC coated textile vascular prostheses tested in sheep

    Czech Academy of Sciences Publication Activity Database

    Jelínek, Miroslav; Kocourek, Tomáš; Podlaha, J.

    2013-01-01

    Roč. 647, JAN (2013), 20-24 ISSN 1022-6680 Institutional support: RVO:68378271 Keywords : DLC * PLD * thin films * vascular prosthesis * pre-clinical study * in vivo Subject RIV: BM - Solid Matter Physics ; Magnetism

  1. Reliability and failure modes of implant-supported zirconium-oxide fixed dental prostheses related to veneering techniques

    Science.gov (United States)

    Baldassarri, Marta; Zhang, Yu; Thompson, Van P.; Rekow, Elizabeth D.; Stappert, Christian F. J.

    2011-01-01

    Summary Objectives To compare fatigue failure modes and reliability of hand-veneered and over-pressed implant-supported three-unit zirconium-oxide fixed-dental-prostheses(FDPs). Methods Sixty-four custom-made zirconium-oxide abutments (n=32/group) and thirty-two zirconium-oxide FDP-frameworks were CAD/CAM manufactured. Frameworks were veneered with hand-built up or over-pressed porcelain (n=16/group). Step-stress-accelerated-life-testing (SSALT) was performed in water applying a distributed contact load at the buccal cusp-pontic-area. Post failure examinations were carried out using optical (polarized-reflected-light) and scanning electron microscopy (SEM) to visualize crack propagation and failure modes. Reliability was compared using cumulative-damage step-stress analysis (Alta-7-Pro, Reliasoft). Results Crack propagation was observed in the veneering porcelain during fatigue. The majority of zirconium-oxide FDPs demonstrated porcelain chipping as the dominant failure mode. Nevertheless, fracture of the zirconium-oxide frameworks was also observed. Over-pressed FDPs failed earlier at a mean failure load of 696 ± 149 N relative to hand-veneered at 882 ± 61 N (profile I). Weibull-stress-number of cycles-unreliability-curves were generated. The reliability (2-sided at 90% confidence bounds) for a 400N load at 100K cycles indicated values of 0.84 (0.98-0.24) for the hand-veneered FDPs and 0.50 (0.82-0.09) for their over-pressed counterparts. Conclusions Both zirconium-oxide FDP systems were resistant under accelerated-life-time-testing. Over-pressed specimens were more susceptible to fatigue loading with earlier veneer chipping. PMID:21557985

  2. Magnetic resonance imaging of breast prostheses | Corr | SA ...

    African Journals Online (AJOL)

    Breast MR imaging is the most accurate imaging investigation to detect breast prosthesis rupture. Rupture is common in older prostheses (> 10 years post implantation) and is often asymptomatic. The radiological signs of rupture are due to collapse of the elastomer shell which is eneveloped by silicone gel and when the ...

  3. Critiquing the Computer-Aided Design of Dental Prostheses.

    Science.gov (United States)

    Fitzpatrick, F. J.; And Others

    This paper describes RaPiD, a computer-aided assistant for the design of dental prostheses called removable partial dentures. The user manipulates icons directly to indicate the desired design solution to a given clinical situation. A developing design is represented as a logic database of components in a design; expert rules are applied as…

  4. Study of effects of radiation on silicone prostheses

    International Nuclear Information System (INIS)

    Shedbalkar, A.R.; Devata, A.; Padanilam, T.

    1980-01-01

    Radiation effects on silicone gel and dose distribution of radiation through mammary prostheses were studied. Silicone gel behaves like tissue. Half value thickness for silicone gel and water are almost the same. Linear absorption coefficient for silicone gel and water are comparable

  5. Evaluation of pneumatic cylinder actuators for hand prostheses

    NARCIS (Netherlands)

    Peerdeman, B.; Smit, Gerwin; Stramigioli, Stefano; Plettenburg, Dick; Misra, Sarthak

    2012-01-01

    DC motors are currently the preferred actuation method for externally powered hand prostheses. However, they are often heavy and large, which limits the number of actuators that can be integrated into the prosthesis. Alternative actuation methods are being researched, but have not yet found wide

  6. Microbial colonization of silicone voice prostheses used in laryngectomized patients

    NARCIS (Netherlands)

    Eerenstein, S. E.; Grolman, W.; Schouwenburg, P. F.

    1999-01-01

    The aim of this study was to identify the microbial colonization of dysfunctioning voice prostheses in laryngectomized patients and determine the influence of patient radiation therapy on prosthesis life span. In a 40-month period, 257 outpatient voice prosthesis replacements were carried out in a

  7. Novel strategies to improve the patency of vascular prostheses

    NARCIS (Netherlands)

    Heyligers, J.M.M.

    2006-01-01

    Two novel strategies to improve the patency of vascular prostheses are described in this thesis. To improve the outcome of synthetic vascular bypass surgery, cell seeding is a promising concept that has extensively been investigated and is still evolving. To improve the short term effects due to

  8. Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy of screening for amblyopia

    OpenAIRE

    Bu?i?, Mladen; Bjelo?, Mirjana; Petrove?ki, Mladen; Kuzmanovi? Elabjer, Biljana; Bosnar, Damir; Rami?, Senad; Mileti?, Daliborka; Andrija?evi?, Lidija; Kond?a Krstonijevi?, Edita; Jakovljevi?, Vid; Bi??an Tvrdi, Ana; Predovi?, Jurica; Kokot, Antonio; Bi??an, Filip; Kova?evi? Ljubi?, Mirna

    2016-01-01

    Aim To present and evaluate a new screening protocol for amblyopia in preschool children. Methods Zagreb Amblyopia Preschool Screening (ZAPS) study protocol performed screening for amblyopia by near and distance visual acuity (VA) testing of 15 648 children aged 48-54 months attending kindergartens in the City of Zagreb County between September 2011 and June 2014 using Lea Symbols in lines test. If VA in either eye was >0.1 logMAR, the child was re-tested, if failed at...

  9. Visualization of and Software for Omnibus Test Based Change Detected in a Time Series of Polarimetric SAR Data

    DEFF Research Database (Denmark)

    Nielsen, Allan Aasbjerg; Conradsen, Knut; Skriver, Henning

    2017-01-01

    Based on an omnibus likelihood ratio test statistic for the equality of several variance-covariance matrices following the complex Wishart distribution and a factorization of this test statistic with associated p-values, change analysis in a time series of multilook polarimetric SAR data...... in the covariance matrix representation is carried out. The omnibus test statistic and its factorization detect if and when change occurs. Using airborne EMISAR and spaceborne RADARSAT-2 data this paper focuses on change detection based on the p-values, on visualization of change at pixel as well as segment level......, and on computer software....

  10. Objective Methods to Test Visual Dysfunction in the Presence of Cognitive Impairment

    Science.gov (United States)

    2015-12-01

    separately for retina or optic nerve damage, 2) eye movement based analysis of target acquisition, fixation, and eccentric viewing as a means of...Using  this  strategy,  normal  eyes   and  eyes  with  well-­‐defined  damage  to  the   retina ,  optic  nerve...the   retina  and   visual  cortex,  and  c)  eye  position  correlated  with  visual  targets  varying  in  spatial

  11. AICRG, Part IV: Patient satisfaction reported for Ankylos implant prostheses.

    Science.gov (United States)

    Morris, Harold F; Ochi, Shigeru; Rodriguez, Arthur; Lambert, Paul M

    2004-01-01

    Although many maxillary dentures exhibit sufficient retention and stability for patients to adapt well to them, mandibular dentures present a major challenge. The introduction of the endosseous dental implant provided the opportunity for the patient to have esthetic replacements (implant prostheses) that were retentive and stable for all missing natural teeth. This paper reports on the satisfaction of over 470 patients with implant prostheses fabricated using a new and innovative implant design (Ankylos, Dentsply-Friadent, Mannheim, Germany). A total of 1500 Ankylos implants were placed, restored, and followed for 3 to 5 years. Patients were asked to respond to a series of questions related to their satisfaction with their new replacements for missing natural teeth. A total of 95.6% of the patients rated chewing ability with Ankylos prosthesis as excellent to good; 92.2% indicated a significant improvement in their ability to chew; 92.6% reported overall clinical function much better than conventional dentures; 99.1% indicated that speech had improved or was not changed; 96.3% indicated hot and cold foods tasted better; 98.8% indicated no pain or discomfort during clinical function; 99.4% liked their new implant prosthesis; 98.0% would seek implant-prostheses treatment again, if necessary; 99.1% would recommend implant prostheses to friends and relatives; and 98.8% indicated the advantages of Ankylos prostheses far exceeded any disadvantages that may exist. Patients indicated that they (1) were highly satisfied with the final results of the replacements for their natural teeth that were retained or supported by this new implant design, (2) would not hesitate to recommend this form of treatment to their friends and relatives, and (3) would not hesitate to seek the same treatment again if necessary in the future.

  12. Fracture analysis of randomized implant-supported fixed dental prostheses.

    Science.gov (United States)

    Esquivel-Upshaw, Josephine F; Mehler, Alex; Clark, Arthur E; Neal, Dan; Anusavice, Kenneth J

    2014-10-01

    Fractures of posterior fixed dental all-ceramic prostheses can be caused by one or more factors including prosthesis design, flaw distribution, direction and magnitude of occlusal loading, nature of supporting infrastructure (tooth root/implant), and presence of adjacent teeth. This clinical study of implant-supported, all-ceramic fixed dental prostheses, determined the effects of (1) presence of a tooth distal to the most distal retainer; (2) prosthesis loading either along the non-load bearing or load bearing areas; (3) presence of excursive contacts or maximum intercuspation contacts in the prosthesis; and (4) magnitude of bite force on the occurrence of veneer ceramic fracture. 89 implant-supported FDPs were randomized as either a three-unit posterior metal-ceramic (Au-Pd-Ag alloy and InLine POM, Ivoclar, Vivadent) FDP or a ceramic-ceramic (ZirCAD and ZirPress, Ivoclar, Vivadent) FDP. Two implants (Osseospeed, Dentsply) and custom abutments (Atlantis, Dentsply) supported these FDPs, which were cemented with resin cement (RelyX Universal Cement). Baseline photographs were made with markings of teeth from maximum intercuspation (MI) and excursive function. Patients were recalled at 6 months and 1-3 years. Fractures were observed, their locations recorded, and images compared with baseline photographs of occlusal contacts. No significant relationship existed between the occurrence of fracture and: (1) the magnitude of bite force; (2) a tooth distal to the most distal retainer; and (3) contacts in load-bearing or non-load-bearing areas. However, there was a significantly higher likelihood of fracture in areas with MI contacts only. Because of the absence of a periodontal ligament, this clinical study demonstrates that there is a need to evaluate occlusion differently with implant-supported prostheses than with natural tooth supported prostheses. Implant supported prostheses should have minimal occlusion and lighter contacts than those supported by natural dentition

  13. A novel test for evaluating horses' spontaneous visual attention is predictive of attention in operant learning tasks.

    Science.gov (United States)

    Rochais, C; Sébilleau, M; Houdebine, M; Bec, P; Hausberger, M; Henry, S

    2017-08-01

    Attention is described as the ability to process selectively one aspect of the environment over others. In this study, we characterized horses' spontaneous attention by designing a novel visual attention test (VAT) that is easy to apply in the animal's home environment. The test was repeated over three consecutive days and repeated again 6 months later in order to assess inter-individual variations and intra-individual stability. Different patterns of attention have been revealed: 'overall' attention when the horse merely gazed at the stimulus and 'fixed' attention characterized by fixity and orientation of at least the visual and auditory organs towards the stimulus. The individual attention characteristics remained consistent over time (after 6 months, Spearman correlation test, P attentional skills was assessed by comparing the results, for the same horses, with those obtained in both a 'classical' experimental attention test the 'five-choice serial reaction time task' (5-CSRTT) and a work situation (lunge working context). Our results revealed that (i) individual variations remained consistent across tests and (ii) the VAT attention measures were not only predictive of attentional skills but also of learning abilities. Differences appeared however between the first day of testing and the following test days: attention structure on the second day was predictive of learning abilities, attention performances in the 5-CSRRT and at work. The VAT appears as a promising easy-to-use tool to assess animals' attention characteristics and the impact of different factors of variation on attention.

  14. Comparative Study of Load Testing Tools: Apache JMeter, HP LoadRunner, Microsoft Visual Studio (TFS, Siege

    Directory of Open Access Journals (Sweden)

    Rabiya Abbas

    2017-12-01

    Full Text Available Software testing is the process of verifying and validating the user’s requirements. Testing is ongoing process during whole software development. Software testing is characterized into three main types. That is, in Black box testing, user doesn’t know domestic knowledge, internal logics and design of system. In white box testing, Tester knows the domestic logic of code. In Grey box testing, Tester has little bit knowledge about the internal structure and working of the system. It is commonly used in case of Integration testing.Load testing helps us to analyze the performance of the system under heavy load or under Zero load. This is achieved with the help of a Load Testing Tool. The intention for writing this research is to carry out a comparison of four load testing tools i.e. Apache JMeter, LoadRunner, Microsoft Visual Studio (TFS, Siege based on certain criteria  i.e. test scripts generation , result reports, application support, plug-in supports, and cost . The main focus is to study these load testing tools and identify which tool is better and more efficient . We assume this comparison can help in selecting the most appropriate tool and motivates the use of open source load testing tools.

  15. Using a Force Concept Inventory Test with Visually Impaired and Blind Students

    Science.gov (United States)

    Bulbul, Mustafa Sahin; Garip, Belkis; Özdemir, Ömer Faruk

    2015-01-01

    This paper reports on a study to determine whether blind students' conceptualizations of force and motion differ from sighted students. This is particularly concerned with the question of whether the students' visual experiences have any relation to their conceptualizations or misconceptualization about force and motion. The research was designed…

  16. Testing the interval-level measurement property of multi-item visual analogue scales.

    NARCIS (Netherlands)

    Krabbe, P.F.M.; Stalmeier, P.F.M.; Lamers, L.M.; Busschbach, J.J.

    2006-01-01

    BACKGROUND: Conditions were studied that may invalidate health-state values derived from the visual analogue scale (VAS). METHODS: Respondents were asked to place cards with descriptions of EQ-5D health states on a 20 cm EuroQol VAS and modified versions of it, positioning them such that the

  17. Testing the interval-level measurement property of multi-item visual analogue scales

    NARCIS (Netherlands)

    Krabbe, Paul F M; Stalmeier, Peep F M; Lamers, Leida M; Busschbach, Jan J V

    2006-01-01

    BACKGROUND: Conditions were studied that may invalidate health-state values derived from the visual analogue scale (VAS). METHODS: Respondents were asked to place cards with descriptions of EQ-5D health states on a 20 cm EuroQol VAS and modified versions of it, positioning them such that the

  18. IAG ring test visual detection of ergot sclerotia in rye 2015

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Rhee, van de N.; Vliege, J.J.M.; Pinckaers, V.G.Z.

    2016-01-01

    Ergot alkaloids are recognised as seriously toxic compounds, which caused a series of outbreaks in the past. In the EU, enforcement is implemented by visual detection and quantification of ergot sclerotia produced by moulds of the genus Claviceps. On behalf of the IAG section Feedstuff Microscopy,

  19. Age Differences in the Relationship between Visual Movement Imagery and Performance on Kinesthetic Acuity Tests.

    Science.gov (United States)

    Livesey, David J.

    2002-01-01

    Investigated the relationship between Vividness of Movement Imagery Questionnaire scores and kinesthetic acuity--the sense of body position and movement--among 10- and 14-year-olds. Found that in the older group, those with high levels of visual movement imagery performed better on measures of kinesthetic acuity; no such effect was found for…

  20. Models Provide Specificity: Testing a Proposed Mechanism of Visual Working Memory Capacity Development

    Science.gov (United States)

    Simmering, Vanessa R.; Patterson, Rebecca

    2012-01-01

    Numerous studies have established that visual working memory has a limited capacity that increases during childhood. However, debate continues over the source of capacity limits and its developmental increase. Simmering (2008) adapted a computational model of spatial cognitive development, the Dynamic Field Theory, to explain not only the source…

  1. Exploring Antecedents of Performance Differences on Visual and Verbal Test Items: Learning Styles versus Aptitude

    Science.gov (United States)

    Bacon, Donald R.; Hartley, Steven W.

    2015-01-01

    Many educators and researchers have suggested that some students learn more effectively with visual stimuli (e.g., pictures, graphs), whereas others learn more effectively with verbal information (e.g., text) (Felder & Brent, 2005). In two studies, the present research seeks to improve popular self-reported (indirect) learning style measures…

  2. Evaluation of non-conformities of hip prostheses made of titanium alloys and stainless steel

    International Nuclear Information System (INIS)

    Bezerra, Ewerton de Oliveira Teotonio; Nascimento, Jose Jeferson da Silva; Luna, Carlos Bruno Barreto; Morais, Crislene Rodrigues da Silva; Campos, Karla Valeria Miranda de

    2017-01-01

    A large number of metallic alloys has satisfactory behavior when used to manufacture implants for hip prostheses. However, they must be in conformity with standards, to ensure their quality for long periods without losing its functionality. Therefore, this paper aims to study the non-conformities in two hip prostheses, one of titanium and other stainless steel according to standards. The implants studied passed by X-ray diffraction (XRD), X-ray fluorescence, tensile test and optical microscopy (OM). Specimens for the tensile test were made according to ASTM E 8M, as well, MO samples passed by metallographic procedure. The results evidenced that some chemical compositions showed in relation to the standards. The XRD analysis showed peaks of austenite and absence of ferrite for the stainless steel, while the titanium alloy presents an alpha phase (HCP) more significant than the beta phase (BCC). The stainless steel alloys and titanium have yield strength and tensile strength that meet the standards. On the other hand, the elastic modulus of the titanium alloy and stainless steel, comes to be ten times greater than the human bone. Therefore, the high modulus of elasticity of the alloys, favors bone resorption problems. The stainless steel microstructure is typical of an austenitic matrix, while the titanium alloy presents α + β microstructure. (author)

  3. Wear Distribution Detection of Knee Joint Prostheses by Means of 3D Optical Scanners

    Directory of Open Access Journals (Sweden)

    Saverio Affatato

    2017-03-01

    Full Text Available The objective of this study was to examine total knee polyethylene inserts from in vitro simulation to evaluate and display—using a 3D optical scanner—wear patterns and wear rates of inserts exposed to wear by means of simulators. Various sets of tibial inserts have been reconstructed by using optical scanners. With this in mind, the wear behavior of fixed and mobile bearing polyethylene knee configurations was investigated using a knee wear joint simulator. After the completion of the wear test, the polyethylene menisci were analyzed by an innovative 3D optical scanners in order to evaluate the 3D wear distribution on the prosthesis surface. This study implemented a new procedure for evaluating polyethylene bearings of joint prostheses obtained after in vitro wear tests and the proposed new approach allowed quantification of the contact zone on the geometry of total knee prostheses. The results of the present study showed that mobile TKPs (total knee prosthesis have lower wear resistance with respect to fixed TKPs.

  4. Stimulation from Cochlear Implant Electrodes Assists with Recovery from Asymmetric Perceptual Tilt: Evidence from the Subjective Visual Vertical Test

    Directory of Open Access Journals (Sweden)

    Joshua J. Gnanasegaram

    2016-09-01

    Full Text Available Vestibular end organ impairment is highly prevalent in children who have sensorineural hearing loss (SNHL rehabilitated with cochlear implants (CIs. As a result, spatial perception is likely to be impacted in this population. Of particular interest is the perception of visual vertical because it reflects a perceptual tilt in the roll axis and is sensitive to an imbalance in otolith function. The objectives of the present study were thus to identify abnormalities in perception of the vertical plane in children with SNHL and determine whether such abnormalities could be resolved with stimulation from the CI. Participants included 53 children (15.2±4.0 years of age with SNHL and vestibular loss, confirmed with vestibular evoked myogenic potential testing. Testing protocol was validated in a sample of 9 young adults with normal hearing (28.8±7.7 years. Perception of visual vertical was assessed using the static Subjective Visual Vertical (SVV test performed with and without stimulation in the participants with cochleovestibular loss. Trains of electrical pulses were delivered by an electrode in the left and/or right ear. Asymmetric spatial orientation deficits were found in nearly half of the participants with CIs (24/53 [45%]. The abnormal perception in this cohort was exacerbated by visual tilts in the direction of their deficit. Electric pulse trains delivered using the CI shifted this abnormal perception towards centre (i.e., normal [p = 0.007]. Importantly, this benefit was realized regardless of which ear was stimulated. These results suggest a role for CI stimulation beyond the auditory system, in particular, for improving vestibular/balance function.

  5. Speed of information processing in children referred for learning problems: performance on a visual filtering test.

    Science.gov (United States)

    Weiler, M D; Harris, N S; Marcus, D J; Bellinger, D; Kosslyn, S M; Waber, D P

    2000-01-01

    Children referred for evaluation of learning impairment (LI, N =100) and a comparison group of nonreferred (NLI, N = 243) children were evaluated on a visual filtering task. The task was designed hierarchically to provide for evaluation of component operations-serial search, parallel search, decision, and response. With each additional processing demand, response times increased disproportionately for the LI group relative to the NLI group. Overall response time reliably predicted academic skills and cognitive ability, but was more strongly related to group membership. Thus, this nonverbal visual task is sensitive to a characteristic of children with learning problems over and above discrete academic and cognitive skills. Children with problems adapting to the demands of schooling may be distinguished by a disproportionate vulnerability to processing load.

  6. A pilot trial of the iPad tablet computer as a portable device for visual acuity testing.

    Science.gov (United States)

    Zhang, Zhao-tian; Zhang, Shao-chong; Huang, Xiong-gao; Liang, Ling-yi

    2013-01-01

    We evaluated the accuracy of an app for the iPad tablet computer (Eye Chart Pro) as a portable method of visual acuity (VA) testing. A total of 120 consecutive patients (240 eyes) underwent visual acuity test with an iPad 2 and a conventional light-box chart. The logMAR VA results from the iPad were significantly higher than those from the light-box (P iPad chart and the light-box chart, with 95% limits of agreement of -0.14 to 0.19. Two groups of patients were defined: in Group 1 there were 182 eyes with VA better than 0.1 according to the light-box VA test. The median logMAR VA by the iPad was 0.54 and by the light-box chart it was 0.52; there was no significant difference between them (P = 0.69). In Group 2 there were 58 eyes with VA equal to or worse than 0.1 according to the light-box VA test. The median logMAR VA by the iPad was 1.26 and was 1.10 by the light box; the result from the iPad was significantly lower (P iPad is reliable for VA testing only when the Snellen VA is better than 0.1 (20/200).

  7. A novel test for evaluating horses' spontaneous visual attention is predictive of attention in operant learning tasks

    Science.gov (United States)

    Rochais, C.; Sébilleau, M.; Houdebine, M.; Bec, P.; Hausberger, M.; Henry, S.

    2017-08-01

    Attention is described as the ability to process selectively one aspect of the environment over others. In this study, we characterized horses' spontaneous attention by designing a novel visual attention test (VAT) that is easy to apply in the animal's home environment. The test was repeated over three consecutive days and repeated again 6 months later in order to assess inter-individual variations and intra-individual stability. Different patterns of attention have been revealed: `overall' attention when the horse merely gazed at the stimulus and `fixed' attention characterized by fixity and orientation of at least the visual and auditory organs towards the stimulus. The individual attention characteristics remained consistent over time (after 6 months, Spearman correlation test, P VAT attention measures were not only predictive of attentional skills but also of learning abilities. Differences appeared however between the first day of testing and the following test days: attention structure on the second day was predictive of learning abilities, attention performances in the 5-CSRRT and at work. The VAT appears as a promising easy-to-use tool to assess animals' attention characteristics and the impact of different factors of variation on attention.

  8. An fMRI-study of locally oriented perception in autism: altered early visual processing of the block design test.

    Science.gov (United States)

    Bölte, S; Hubl, D; Dierks, T; Holtmann, M; Poustka, F

    2008-01-01

    Autism has been associated with enhanced local processing on visual tasks. Originally, this was based on findings that individuals with autism exhibited peak performance on the block design test (BDT) from the Wechsler Intelligence Scales. In autism, the neurofunctional correlates of local bias on this test have not yet been established, although there is evidence of alterations in the early visual cortex. Functional MRI was used to analyze hemodynamic responses in the striate and extrastriate visual cortex during BDT performance and a color counting control task in subjects with autism compared to healthy controls. In autism, BDT processing was accompanied by low blood oxygenation level-dependent signal changes in the right ventral quadrant of V2. Findings indicate that, in autism, locally oriented processing of the BDT is associated with altered responses of angle and grating-selective neurons, that contribute to shape representation, figure-ground, and gestalt organization. The findings favor a low-level explanation of BDT performance in autism.

  9. Modified Design of Pin-on-Ring Tribometer for Hip Joint Prostheses Measurement; Case Study on Salat Activity

    Directory of Open Access Journals (Sweden)

    Muhammad Khafidh

    2015-02-01

    Full Text Available Total hip replacement (THR is one of the most successful orthopedic surgical procedures for replacing a broken hip joint. In THR, wear may occur at the articulating surface of the acetabular cup and the femoral head. In Indonesia, the country with the largest Muslim population in the world, most of the inhabitants do salat (praying every day. THR users are banned from doing salat for fear it will damage the hip joint prostheses. The previous wear calculation methods on the hip joint prostheses use the gravimetric, coordinate measuring machine (CMM, profiler, and geometric method. The disadvantages of the previous methods are that the geometry of the wear patch and the wear volume are only known at the end of the experiment, so they cannot be used to calculate the specific wear rate values in real time. So far, in every modeling of the hip joint prostheses, the values of the specific wear rate are assumed to be constant. This paper reports on the design modification of a pin-on-ring tribometer that is used to measure the wear volumes in hip joint prostheses. The result shows that modifications of the femoral head holder, reciprocating motion, elastic joint, and extra displacement transducer is needed to get the specific wear rate value. The calculation method to find the delta volume that is the value of displacement less than the displacement minimum (δmin is based on a graph, while the calculation method to find the delta volume that is the value of displacement that is more than the displacement minimum (δmin is based on an equation. In the salat test protocol, the longest test time was during the sujud (prostration motion, which took 1034.17 minutes in the experiment.

  10. Color vision deficiency compensation for Visual Processing Disorder using Hardy-Rand-Rittler test and color transformation

    Science.gov (United States)

    Balbin, Jessie R.; Pinugu, Jasmine Nadja J.; Bautista, Joshua Ian C.; Nebres, Pauline D.; Rey Hipolito, Cipriano M.; Santella, Jose Anthony A.

    2017-06-01

    Visual processing skill is used to gather visual information from environment however, there are cases that Visual Processing Disorder (VPD) occurs. The so called visual figure-ground discrimination is a type of VPD where color is one of the factors that contributes on this type. In line with this, color plays a vital role in everyday living, but individuals that have limited and inaccurate color perception suffers from Color Vision Deficiency (CVD) and still not aware on their case. To resolve this case, this study focuses on the design of KULAY, a Head-Mounted Display (HMD) device that can assess whether a user has a CVD or not thru the standard Hardy-Rand-Rittler (HRR) test. This test uses pattern recognition in order to evaluate the user. In addition, color vision deficiency simulation and color correction thru color transformation is also a concern of this research. This will enable people with normal color vision to know how color vision deficient perceives and vice-versa. For the accuracy of the simulated HRR assessment, its results were validated thru an actual assessment done by a doctor. Moreover, for the preciseness of color transformation, Structural Similarity Index Method (SSIM) was used to compare the simulated CVD images and the color corrected images to other reference sources. The output of the simulated HRR assessment and color transformation shows very promising results indicating effectiveness and efficiency of the study. Thus, due to its form factor and portability, this device is beneficial in the field of medicine and technology.

  11. Manufacturing Implant Supported Auricular Prostheses by Rapid Prototyping Techniques

    Science.gov (United States)

    Karatas, Meltem Ozdemir; Cifter, Ebru Demet; Ozenen, Didem Ozdemir; Balik, Ali; Tuncer, Erman Bulent

    2011-01-01

    Maxillofacial prostheses are usually fabricated on the models obtained following the impression procedures. Disadvantages of conventional impression techniques used in production of facial prosthesis are deformation of soft tissues caused by impression material and disturbance of the patient due to. Additionally production of prosthesis by conventional methods takes longer time. Recently, rapid prototyping techniques have been developed for extraoral prosthesis in order to reduce these disadvantages of conventional methods. Rapid prototyping technique has the potential to simplify the procedure and decrease the laboratory work required. It eliminates the need for measurement impression procedures and preparation of wax model to be performed by prosthodontists themselves In the near future this technology will become a standard for fabricating maxillofacial prostheses. PMID:21912504

  12. Indium-111 chloride imaging in the detection of infected prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Sayle, B.A.; Fawcett, H.D.; Wilkey, D.J.; Cierny, G. III; Mader, J.T.

    1985-07-01

    Thirty-three patients with painful joint prostheses and a suspicion of infection were imaged with (/sup 111/In)chloride. A final diagnosis was established by culture in 19. Of these, 12 were categorized as true positives and three as true negatives. There were two false-positive studies, occurring in patients with knee prostheses. In both, the culture was obtained by aspiration. The sensitivity was 86%, specificity 60%, and accuracy 79%. Seventeen of the proven cases had bone imaging prior to (/sup 111/In)chloride imaging. All 17 static images were positive and were not helpful in differentiating loosening from infection. Using increased uptake on the blood-pool image as a criteria for infection, the sensitivity was 89%, but the specificity was 0. Adding flow studies made little difference in interpreting the blood-pool images. This study shows that (/sup 111/In)chloride imaging is more accurate in evaluating infection in prosthesis than bone imaging.

  13. Recent Patents and Designs on Hip Replacement Prostheses

    Science.gov (United States)

    Derar, H; Shahinpoor, M

    2015-01-01

    Hip replacement surgery has gone through tremendous evolution since the first procedure in 1840. In the past five decades the advances that have been made in technology, advanced and smart materials innovations, surgical techniques, robotic surgery and methods of fixations and sterilization, facilitated hip implants that undergo multiple design revolutions seeking the least problematic implants and a longer survivorship. Hip surgery has become a solution for many in need of hip joint remedy and replacement across the globe. Nevertheless, there are still long-term problems that are essential to search and resolve to find the optimum implant. This paper reviews several recent patents on hip replacement surgery. The patents present various designs of prostheses, different materials as well as methods of fixation. Each of the patents presents a new design as a solution to different issues ranging from the longevity of the hip prostheses to discomfort and inconvenience experienced by patients in the long-term. PMID:25893020

  14. Polyrethene nasolacrimal prostheses. Assessment of the complications using computed tomography

    International Nuclear Information System (INIS)

    Pino, I. T.; Paul, L.; Duran, M. A.; Grande, C.

    1999-01-01

    To assess the outcome of treatment of epiphora secondary to nasolacrimal duct obstruction by placement of a polyurethane prosthesis. We placed 20 polyurethane prostheses (song's prostheses) in 19 patients with nasolacrimal duct obstruction who presented idiopathic grade III-IV epiphora. All the patients underwent CT with follow-up studies 10 days, one month and three months after prosthesis placement. Epiphora resolved completely in 13 cases and partially in four. In two cases, the prosthesis was poorly positioned; one of them was replaced and the other functions to date. There were three cases of obstruction. We observed limited epistaxis in 7 patients and headache in one. The treatment of epiphora by polyurethane prosthesis placement is a simple procedure that is well tolerated by patients and has a high success rate. (Author) 14 refs

  15. Characterization of spent fuel elements stored at IEA-R1 research reactor based on visual inspections and sipping tests

    International Nuclear Information System (INIS)

    Silva, Jose Eduardo Rosa da; Terremoto, Luis Antonio Albiac; Teodoro, Celso Antonio; Castanheira, Myrthes; Lucki, Georgi; Damy, Margaret de Almeida; Silva, Antonio Teixeira e

    2005-01-01

    Aluminum spent nuclear fuels are susceptible to corrosion attack, or mechanical damage from improper handling, while in pool reactor storage. Storage practices have been modified to reduce the potential for damage, based on recommendations presented at second WS on Spent Fuel Characterization, promoted by IAEA. In this work, we present the inspection program proposed to the IEA-R1 stored spent fuel elements, in order to provide information on the physical condition during the interim storage time under wet condition at the reactor pool. The inspection program is based on non-destructive tests results (visual inspection and sipping tests) already periodically performed to exam the IEA-R1 stored spent fuel and fuel elements from the core reactor. To record the available information and examination results it was elaborated a document in the format of a catalogue containing the proposed inspection program for the IEA-R1 stored spent fuel, the description of the visual inspection and sipping tests systems, a compilation of information and images result from the tests performed for all stored standard spent fuel element and, in annexes, copies of the reference documents. That document constitutes an important step of the effective implementation of the referred IEA-R1 spent fuel inspection program and can be used to address regulatory and operational needs for the demonstration, for example, of safe storage throughout the pool storage period. (author)

  16. Characterization of spent fuel elements stored at IEA-R1 research reactor based on visual inspections and sipping tests

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Jose Eduardo Rosa da; Terremoto, Luis Antonio Albiac; Teodoro, Celso Antonio; Castanheira, Myrthes; Lucki, Georgi; Damy, Margaret de Almeida; Silva, Antonio Teixeira e [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: jersilva@ipen.br

    2005-07-01

    Aluminum spent nuclear fuels are susceptible to corrosion attack, or mechanical damage from improper handling, while in pool reactor storage. Storage practices have been modified to reduce the potential for damage, based on recommendations presented at second WS on Spent Fuel Characterization, promoted by IAEA. In this work, we present the inspection program proposed to the IEA-R1 stored spent fuel elements, in order to provide information on the physical condition during the interim storage time under wet condition at the reactor pool. The inspection program is based on non-destructive tests results (visual inspection and sipping tests) already periodically performed to exam the IEA-R1 stored spent fuel and fuel elements from the core reactor. To record the available information and examination results it was elaborated a document in the format of a catalogue containing the proposed inspection program for the IEA-R1 stored spent fuel, the description of the visual inspection and sipping tests systems, a compilation of information and images result from the tests performed for all stored standard spent fuel element and, in annexes, copies of the reference documents. That document constitutes an important step of the effective implementation of the referred IEA-R1 spent fuel inspection program and can be used to address regulatory and operational needs for the demonstration, for example, of safe storage throughout the pool storage period. (author)

  17. Two Fungal Infections of Inflatable Penile Prostheses in Diabetics

    Directory of Open Access Journals (Sweden)

    Brittney H. Cotta, MD

    2015-12-01

    Conclusions: This report supports the emerging literature that the flora of IPP infections is changing. We suggest considering adding antifungal agents to antibiotic coatings, dips, or washout solutions at the time of penile prosthesis surgery in diabetic patients. Cotta BH, Butcher M, Welliver C, McVary K, and Köhler T. Two fungal infections of inflatable penile prostheses in diabetics. Sex Med 2015;3:339–342.

  18. Tissue Engineered Testicular Prostheses With Prolonged Testosterone Release

    Science.gov (United States)

    2008-12-01

    in infertile men. Fertil. Steril ., Epub ahead of print. Marshall, S., 1986: Potential problems with testicular prostheses. Urology, 28, 388-390...strengths to maintain structural integrity. The polymers were sterilized in ethylene oxide and placed under sterile conditions until cell delivery...washed in Povidone-iodine 10% solution, and dissected into 2 to 3 mm tissue fragments. Chondrocytes were isolated under sterile conditions using a

  19. Electromyographic evaluation of mastication and swallowing in elderly individuals with mandibular fixed implant-supported prostheses

    Directory of Open Access Journals (Sweden)

    Giédre Berretin-Felix

    2008-04-01

    Full Text Available This study evaluated the effect of implant-supported oral rehabilitation in the mandible on the electromyographic activity during mastication and swallowing in edentulous elderly individuals. Fifteen patients aged more than 60 years were evaluated, being 10 females and 5 males. All patients were edentulous, wore removable complete dentures on both dental arches, and had the mandibular dentures replaced by implant-supported prostheses. All patients were submitted to electromyographic evaluation of the masseter, superior orbicularis oris muscles, and the submental muscles, before surgery and 3, 6 and 18 months postoperatively, using foods of different textures. The results obtained at the different periods were analyzed statistically by Kruskal-Wallis non-parametric test. Statistical analysis showed that only the masseter muscle had a significant loss in electromyographic activity (p<0.001, with a tendency of similar response for the submental muscles. Moreover, there was an increase in the activity of the orbicularis oris muscle during rubber chewing after treatment, yet without statistically significant difference. Mandibular fixed implant-supported prostheses in elderly individuals revealed a decrease in electromyographic amplitude for the masseter muscles during swallowing, which may indicate adaptation to new conditions of stability provided by fixation of the complete denture in the mandibular arch.

  20. Electromyography data for non-invasive naturally-controlled robotic hand prostheses.

    Science.gov (United States)

    Atzori, Manfredo; Gijsberts, Arjan; Castellini, Claudio; Caputo, Barbara; Hager, Anne-Gabrielle Mittaz; Elsig, Simone; Giatsidis, Giorgio; Bassetto, Franco; Müller, Henning

    2014-01-01

    Recent advances in rehabilitation robotics suggest that it may be possible for hand-amputated subjects to recover at least a significant part of the lost hand functionality. The control of robotic prosthetic hands using non-invasive techniques is still a challenge in real life: myoelectric prostheses give limited control capabilities, the control is often unnatural and must be learned through long training times. Meanwhile, scientific literature results are promising but they are still far from fulfilling real-life needs. This work aims to close this gap by allowing worldwide research groups to develop and test movement recognition and force control algorithms on a benchmark scientific database. The database is targeted at studying the relationship between surface electromyography, hand kinematics and hand forces, with the final goal of developing non-invasive, naturally controlled, robotic hand prostheses. The validation section verifies that the data are similar to data acquired in real-life conditions, and that recognition of different hand tasks by applying state-of-the-art signal features and machine-learning algorithms is possible.

  1. Electromyography data for non-invasive naturally-controlled robotic hand prostheses

    Science.gov (United States)

    Atzori, Manfredo; Gijsberts, Arjan; Castellini, Claudio; Caputo, Barbara; Hager, Anne-Gabrielle Mittaz; Elsig, Simone; Giatsidis, Giorgio; Bassetto, Franco; Müller, Henning

    2014-01-01

    Recent advances in rehabilitation robotics suggest that it may be possible for hand-amputated subjects to recover at least a significant part of the lost hand functionality. The control of robotic prosthetic hands using non-invasive techniques is still a challenge in real life: myoelectric prostheses give limited control capabilities, the control is often unnatural and must be learned through long training times. Meanwhile, scientific literature results are promising but they are still far from fulfilling real-life needs. This work aims to close this gap by allowing worldwide research groups to develop and test movement recognition and force control algorithms on a benchmark scientific database. The database is targeted at studying the relationship between surface electromyography, hand kinematics and hand forces, with the final goal of developing non-invasive, naturally controlled, robotic hand prostheses. The validation section verifies that the data are similar to data acquired in real-life conditions, and that recognition of different hand tasks by applying state-of-the-art signal features and machine-learning algorithms is possible. PMID:25977804

  2. Association between self-rated oral appearance and the need for dental prostheses among elderly Brazilians

    Directory of Open Access Journals (Sweden)

    Emília Araújo Vilela

    2013-06-01

    Full Text Available We investigated the association between poor self-rated oral appearance and the need for dental prostheses among elderly Brazilians. National data from an epidemiological survey on oral health in Brazil conducted from 2002 to 2003 by the Ministry of Health (SB, Brazil with a multistage random sample of 4,839 individuals aged 65–74 years in 250 towns were analyzed. The dependent variable was self-rated oral appearance, dichotomized into “poor” (poor∕very poor and “good” (fair∕good∕very good. The main independent variable was the need for an upper or lower dental prosthesis. Other variables included sociodemographic characteristics, approach to dental care, oral health conditions, and self-reported oral disadvantage. Data were analyzed using the chi-square test and Poisson regression models at a 95% significance level. The prevalence of poor self-rated oral appearance was 20.6% and was higher in the elderly who needed a partial or complete upper or lower prosthesis, independent of other variables. This prevalence was associated with age, the use of dental services, access to information about oral disease prevention, number of decayed teeth, self-perception of the need for treatment, dental pain, chewing ability, and the perception that oral health affects relationships with other people. The elderly who needed dental prostheses had a higher prevalence of poor self-rated oral appearance than those who did not need any.

  3. Effect of occlusal support by implant prostheses on brain function.

    Science.gov (United States)

    Okamoto, Naoko

    2011-10-01

    The present study was carried out to identify how gum chewing with and without occlusal support by implant prostheses affects brain function as well as chewing function. Twenty-four subjects rehabilitated with implant-supported fixed prostheses were evaluated. An electroencephalograph (EEG) (ESA-Pro) and mandibular kinesiograph (Bio PAK(®)) wear used to measure brain function and chewing function, respectively, before and after gum chewing with and without an implant superstructure. Based on brain function estimated by the Dα values derived from measurement data, the subjects were divided into the normal region group (including the sub-normal region group) (n=15; Dα≥0.952) and the impaired region group (n=9; DαBrain function in the normal region group showed no change after gum chewing, whether or not an implant superstructure was in place (p>0.05). However, brain function in the impaired region group showed significant improvement after gum chewing (pbrain function compared to the results without an implant superstructure. In the impaired region group, there was a high positive correlation between brain function and masticatory movement (γ=0.75). Subjects in the impaired region group revealed a strong positive correlation between brain function and masticatory movement, indicating that occlusal support by implant-supported fixed prostheses has the potential to enhance brain function. Copyright © 2011 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  4. Developing Testing Accommodations for English Language Learners: Illustrations as Visual Supports for Item Accessibility

    Science.gov (United States)

    Solano-Flores, Guillermo; Wang, Chao; Kachchaf, Rachel; Soltero-Gonzalez, Lucinda; Nguyen-Le, Khanh

    2014-01-01

    We address valid testing for English language learners (ELLs)--students in the United States who are schooled in English while they are still acquiring English as a second language. Also, we address the need for procedures for systematically developing ELL testing accommodations--changes in tests intended to support ELLs to gain access to the…

  5. Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy of screening for amblyopia.

    Science.gov (United States)

    Bušić, Mladen; Bjeloš, Mirjana; Petrovečki, Mladen; Kuzmanović Elabjer, Biljana; Bosnar, Damir; Ramić, Senad; Miletić, Daliborka; Andrijašević, Lidija; Kondža Krstonijević, Edita; Jakovljević, Vid; Bišćan Tvrdi, Ana; Predović, Jurica; Kokot, Antonio; Bišćan, Filip; Kovačević Ljubić, Mirna; Motušić Aras, Ranka

    2016-02-01

    To present and evaluate a new screening protocol for amblyopia in preschool children. Zagreb Amblyopia Preschool Screening (ZAPS) study protocol performed screening for amblyopia by near and distance visual acuity (VA) testing of 15 648 children aged 48-54 months attending kindergartens in the City of Zagreb County between September 2011 and June 2014 using Lea Symbols in lines test. If VA in either eye was >0.1 logMAR, the child was re-tested, if failed at re-test, the child was referred to comprehensive eye examination at the Eye Clinic. 78.04% of children passed the screening test. Estimated prevalence of amblyopia was 8.08%. Testability, sensitivity, and specificity of the ZAPS study protocol were 99.19%, 100.00%, and 96.68% respectively. The ZAPS study used the most discriminative VA test with optotypes in line as they do not underestimate amblyopia. The estimated prevalence of amblyopia was considerably higher than reported elsewhere. To the best of our knowledge, the ZAPS study protocol reached the highest sensitivity and specificity when evaluating diagnostic accuracy of VA tests for screening. The pass level defined at ≤0.1 logMAR for 4-year-old children, using Lea Symbols in lines missed no amblyopia cases, advocating that both near and distance VA testing should be performed when screening for amblyopia.

  6. Visual analogical well-being scale for sleep apnea patients: validity and responsiveness : a test for clinical practice.

    Science.gov (United States)

    Masa, Juan F; Jiménez, Antonio; Durán, Joaquín; Carmona, Carmen; Monasterio, Carmen; Mayos, Mercedes; Terán, Joaquín; Barbé, Ferrán; Rubio, Manuela; Failde, Inmaculada; Mota, Manuel; Montserrat, José M

    2011-09-01

    Health-related quality-of-life (HRQL) tests used in sleep apnea-hypopnea syndrome (SAHS) are time-consuming, complicating their application in clinical practice. The objective was to examine the validity and responsiveness of a simple visual analogical well-being scale (VAWS) for the clinical use. The subjects proceed from a cohort of SAHS patients treated with CPAP for 12 weeks. We correlated the VAWS with other HRQL tests, related clinical and polysomnographic measures to concurrent and construct validities. Responsiveness by: (1) comparison of HRQL tests between before and after treatment and effect size. (2) Association of the change with treatment between VAWS with other HRQL tests and between VAWS with clinical parameters. At baseline, VAWS correlated with all HRQL tests but better with functional outcomes in sleep questionnaires (FOSQ) and European quality-of-life questionnaire (EuroQol) thermometer. VAWS and FOSQ correlated better with clinical variables than other HRQL tests. VAWS captures the magnitude change with treatment similarly to FOSQ but better than other HRQL tests. VAWS is a very simple test which measures HRQL in SAHS. It could be a useful tool in clinical practice, primarily for the responsiveness of treatment.

  7. Comparison of mechanical and biological prostheses when used to replace heart valves in children and adolescents with rheumatic fever.

    Science.gov (United States)

    Travancas, Paulo R; Dorigo, Ana H; Simões, Luiz C; Fonseca, Sandra C; Bloch, Kátia V; Herdy, Gesmar V

    2009-04-01

    To assess the outcomes in children and adolescents with rheumatic fever of the implantation of mechanical as opposed to biological heart valves. We assessed 73 patients with rheumatic heart disease under the age of 18 years, who underwent replacement of heart valves between January, 1996, and December, 2005, at the National Institute of Cardiology in Rio de Janeiro, Brazil. Of the group, 71 patients survived, and were divided into a group of 52 receiving mechanical prostheses, and 19 with biological prostheses. We compared endpoints between the groups in terms of mortality, reoperation, haemorrhage, and stroke. Survival curves were estimated using the Kaplan-Meier method and were compared by the Mantel (log-rank) test. Overall mortality was 8.2%. In those receiving mechanical prostheses, 2 (3.8%) patients died, 5 (9.6%) underwent reoperation, 2 (3.8%) suffered severe haemorrhage, and 3 (5.8%) had strokes. In those receiving biological valves, 2 (10.5%) patients died, and 4 (21%) underwent reoperation. After 2, 4, and 8 years, overall survival was 96%, 93% and 86%, respectively, with a borderline difference between the groups (p = 0.06). The probabilities of remaining free from reoperation (p = 0.13), and from combined endpoints, showed no statistically significant difference between the groups (p = 0.28). Patients with mechanical prostheses had lower mortality and required fewer reoperations, but when all combined endpoints were considered, the groups did not differ. The biological prosthesis proved to be a good option for cardiac surgery in children and adolescents with difficulties or risks of anticoagulation.

  8. Reliability of kinetic visual field testing in children with mutation-proven retinal dystrophies: Implications for therapeutic clinical trials.

    Science.gov (United States)

    Dedania, Vaidehi S; Liu, Jerry Y; Schlegel, Dana; Andrews, Chris A; Branham, Kari; Khan, Naheed W; Musch, David C; Heckenlively, John R; Jayasundera, K Thiran

    2018-01-01

    Kinetic visual field testing is used to monitor disease course in retinal dystrophy clinical care and treatment response in treatment trials, which are increasingly recruiting children. This study investigates Goldmann visual field (GVF) changes in young children with mutation-proven retinal dystrophies as they age and with progression of the retinal degeneration. Retrospective review of children ≤ 17 years old with a mutation-proven retinal dystrophy. Objective clinical disease activity was assessed by a retinal degeneration specialist masked to GVF results. Digital quantification of GVF area was performed. Twenty-nine children (58 eyes), ages 5-16, were identified. GVF area increased with age despite progression in 20 children and clinical stability in nine children. Mean ± standard error increase in GVF area/year was 333 ± 130 mm 2 (I4e, p = 0.012), 720 ± 155 mm 2 (III4e, p children with mutation-proven retinal dystrophies, there is a significant increase in GVF area with age, particularly those children with retinal dystrophies can be an unreliable measure of response to treatment and on which to base appropriate counseling about visual impairment.

  9. Improving test-retest variability of visual-evoked responses in multiple sclerosis: implications for trial design.

    Science.gov (United States)

    Thomae, Eva; Niklas, Alexander; Sebraoui, Hatifa; Baum, Petra; Wagner, Armin; Then Bergh, Florian

    2010-08-01

    Remyelination is an important repair strategy in multiple sclerosis. Latencies of visual-evoked responses are a suitable surrogate for remyelination of the optic nerve. Their test-retest variability has been incompletely evaluated, especially in pathologically delayed potentials. Visual-evoked potential was recorded twice, 2.1 +/- 3.1 (mean +/- SD) days apart, in 39 patients with definite or evaluated for multiple sclerosis. Acute optic neuritis and current steroid treatment were exclusion criteria. Mean and difference of the two recordings were calculated for latencies and amplitude, both before and after verification of cursor positioning by a physician blinded for the sequence of recordings. Before verification, the difference between first and second visual-evoked potential was -2.07 +/- 9.07 milliseconds for N75 latency, -1.18 +/- 8.02 milliseconds for P100 latency, and -0.06 +/- 2.71 muV for N75/P100 amplitude (n = 77 eyes, mean +/- SD). Independent verification judged two eyes as unsuitable for analysis. The differences in the remaining 75 eyes were reduced to -1.22 +/- 6.86 milliseconds (N75), -0.7 +/- 3.85 milliseconds (P100) and -0.04 +/- 2.53 microV (amplitude). These effects do not differ between delayed and nondelayed eyes. Similar to magnetic resonance imaging, use of evoked potentials in multiple sclerosis remyelination trials will require independent verification, ideally by a central evaluating facility. Reproducibility should be verified individually at screening.

  10. µCT-3D visualization analysis of resin composite polymerization and dye penetration test of composite adaptation.

    Science.gov (United States)

    Yoshikawa, Takako; Sadr, Alireza; Tagami, Junji

    2018-01-30

    This study evaluated the effects of the light curing methods and resin composite composition on composite polymerization contraction behavior and resin composite adaptation to the cavity wall using μCT-3D visualization analysis and dye penetration test. Cylindrical cavities were restored using Clearfil tri-S Bond ND Quick adhesive and filled with Clearfil AP-X or Clearfil Photo Bright composite. The composites were cured using the conventional or the slow-start curing method. The light-cured resin composite, which had increased contrast ratio during polymerization, improved adaptation to the cavity wall using the slow-start curing method. In the μCT-3D visualization method, the slow-start curing method reduced polymerization shrinkage volume of resin composite restoration to half of that produced by the conventional curing method in the cavity with adhesive for both composites. μCT-3D visualization method can be used to detect and analyze resin composite polymerization contraction behavior and shrinkage volume as 3D image in the cavity.

  11. X-Ray Microtomography (μCT as a Useful Tool for Visualization and Interpretation of Shear Strength Test Results

    Directory of Open Access Journals (Sweden)

    Stefaniuk Damian

    2015-02-01

    Full Text Available The paper demonstrates the applicability of X-ray microtomography (ìCT to analysis of the results of shear strength examinations of clayey soils. The method of X-ray three-dimensional imaging offers new possibilities in soil testing. The work focuses on a non-destructive method of evaluation of specimen quality used in shear tests and mechanical behavior of soil. The paper presents the results of examination of 4 selected clayey soils. Specimens prepared for the triaxial test have been scanned using ìCT before and after the triaxial compression tests. The shear strength parameters of the soils have been estimated. Changes in soil structure caused by compression and shear failure have been presented as visualizations of the samples tested. This allowed for improved interpretation and evaluation of soil strength parameters and recognition of pre-existing fissures and the exact mode of failure. Basic geometrical parameters have been determined for selected cross-sections of specimens after failure. The test results indicate the utility of the method applied in soil testing.

  12. Fabrication of biosynthetic vascular prostheses by 193-nm excimer laser radiation

    Science.gov (United States)

    Husinsky, Wolfgang; Csek, Ch.; Bartel, A.; Grabenwoeger, M.; Fitzal, F.; Wolner, Ernst

    1998-05-01

    This study was undertaken to investigate the feasibility of transmural capillary ingrowth into the inner surface of biosynthetic vascular prostheses (OmniflowTM) through perforations created by an excimer-laser, thus inducing an endothelial cell coverage. The biosynthetic vascular prostheses (10 cm length, 6 mm (phi) ) were perforated with an excimer laser ((phi) of the holes 50 - 100 micrometer, distance 4 mm) and implanted into the carotid arteries of 8 sheep. The laser tissue interaction process of 193 nm radiation ensures minimal thermal damage to the prostheses. They were compared to untreated OmniflowTM prostheses implanted at the contralateral side. Three months after implantation the prostheses were explanted and evaluated by gross morphology, histological examination and scanning electron microscopy. Scanning electron microscopy showed endothelial cells in the midgraft portion of all perforated prostheses, whereas collagen fibers, fibrin meshwork and activated platelets formed the inner layer in 6 out of 8 untreated OmniflowTM prostheses. It can be concluded, that spontaneous endothelialization of biosynthetic vascular prostheses can be achieved by transmural capillary ingrowth through perforations in the wall of the prostheses in an experimental sheep model.

  13. A Novel Computerized Test for Detecting and Monitoring Visual Attentional Deficits and Delirium in the ICU.

    Science.gov (United States)

    Green, Cameron; Hendry, Kirsty; Wilson, Elizabeth S; Walsh, Timothy; Allerhand, Mike; MacLullich, Alasdair M J; Tieges, Zoë

    2017-07-01

    Delirium in the ICU is associated with poor outcomes but is under-detected. Here we evaluated performance of a novel, graded test for objectively detecting inattention in delirium, implemented on a custom-built computerized device (Edinburgh Delirium Test Box-ICU). A pilot study was conducted, followed by a prospective case-control study. Royal Infirmary of Edinburgh General ICU. A pilot study was conducted in an opportunistic sample of 20 patients. This was followed by a validation study in 30 selected patients with and without delirium (median age, 63 yr; range, 23-84) who were assessed with the Edinburgh Delirium Test Box-ICU on up to 5 separate days. Presence of delirium was assessed using the Confusion Assessment Method for the ICU. The Edinburgh Delirium Test Box-ICU involves a behavioral assessment and a computerized test of attention, requiring patients to count slowly presented lights. Thirty patients were assessed a total of 79 times (n = 31, 23, 15, 8, and 2 for subsequent assessments; 38% delirious). Edinburgh Delirium Test Box-ICU scores (range, 0-11) were lower for patients with delirium than those without at the first (median, 0 vs 9.5), second (median, 3.5 vs 9), and third (median, 0 vs 10.5) assessments (all p Delirium Test Box-ICU score less than or equal to 5 was 100% sensitive and 92% specific to delirium across assessments. Longitudinally, participants' Edinburgh Delirium Test Box-ICU performance was associated with delirium status. These findings suggest that the Edinburgh Delirium Test Box-ICU has diagnostic utility in detecting ICU delirium in patients with Richmond Agitation and Sedation Scale Score greater than -3. The Edinburgh Delirium Test Box-ICU has potential additional value in longitudinally tracking attentional deficits because it provides a range of scores and is sensitive to change.

  14. EPRI/DOE High Burnup Fuel Sister Pin Test Plan Simplification and Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Saltzstein, Sylvia J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorenson, Ken B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hanson, Brady [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Billone, Mike [Argonne National Lab. (ANL), Argonne, IL (United States); Scaglione, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Montgomery, Rose [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bevard, Bruce [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-07-01

    The EPRI/DOE High Burnup Confirmatory Data Project (herein called the "Demo") is a multi-year, multi-entity confirmation demonstration test with the purpose of providing quantitative and qualitative data to show how high-burnup fuel ages in dry storage over a ten-year period. The Demo involves obtaining 32 assemblies of high-burnup PWR fuel of four common cladding alloys from the North Anna Nuclear Power Plant, drying them according to standard plant procedures, and then storing them in an NRC-licensed TN-3 2B cask on the North Anna dry storage pad for ten years. After the ten-year storage time, the cask will be opened and the rods will be examined for signs of aging. Twenty-five rods from assemblies of similar claddings, in-reactor placement, and burnup histories (herein called "sister rods") have been shipped from the North Anna Nuclear Power Plant and are currently being nondestructively tested at Oak Ridge National Laboratory. After the non-destructive testing has been completed for each of the twenty-five rods, destructive analysis will be performed at ORNL, PNNL, and ANL to obtain mechanical data. Opinions gathered from the expert interviews, ORNL and PNNL Sister Rod Test Plans, and numerous meetings has resulted in the Simplified Test Plan described in this document. Some of the opinions and discussions leading to the simplified test plan are included here. Detailed descriptions and background are in the ORNL and PNNL plans in the appendices . After the testing described in this simplified test plan h as been completed , the community will review all the collected data and determine if additional testing is needed.

  15. Crowding in central vision in normally sighted and visually impaired [corrected] children aged 4 to 8 years: the influence of age and test design.

    Science.gov (United States)

    Huurneman, Bianca; Boonstra, F Nienke; Cillessen, Antonius H N; van Rens, Ger; Cox, Ralf F A

    2012-06-01

    To investigate crowding ratios in children with a visual impairment due to ocular disease (n = 58) and normally sighted children (n = 75) aged 4 to 8 years using several variants of two clinically available tests with different optotype spacing (fixed or proportional to the optotype size). Crowding ratios, calculated by dividing the single acuity by the linear acuity, were measured binocularly with the C-test and the LH line chart. Ratios >1.00 indicate crowding. The charts with fixed spacing revealed significantly higher crowding ratios for visually impaired children than normally sighted children (both for measurements at 40 cm and 5 m). The age-related reduction of the crowding ratios seen in normally sighted children when tested with near-vision charts with fixed spacing was not present in the visually impaired group. Visually impaired children with nystagmus showed higher crowding ratios than visually impaired children without nystagmus. The chart with proportional intersymbol spacing (ISS) did not reveal differences between the normally sighted and visually impaired children; nor did it show group, age, or nystagmus effects. Visually impaired children showed higher crowding ratios than normally sighted children when measured with charts with fixed ISS. This study illustrates that test design and target/flanker interference as a manifestation of crowding are critical issues to bear in mind when assessing crowding ratios in children.

  16. Testing a Poisson counter model for visual identification of briefly presented, mutually confusable single stimuli in pure accuracy tasks.

    Science.gov (United States)

    Kyllingsbæk, Søren; Markussen, Bo; Bundesen, Claus

    2012-06-01

    The authors propose and test a simple model of the time course of visual identification of briefly presented, mutually confusable single stimuli in pure accuracy tasks. The model implies that during stimulus analysis, tentative categorizations that stimulus i belongs to category j are made at a constant Poisson rate, v(i, j). The analysis is continued until the stimulus disappears, and the overt response is based on the categorization made the greatest number of times. The model was evaluated by Monte Carlo tests of goodness of fit against observed probability distributions of responses in two extensive experiments and also by quantifications of the information loss of the model compared with the observed data by use of information theoretic measures. The model provided a close fit to individual data on identification of digits and an apparently perfect fit to data on identification of Landolt rings.

  17. Role of subjective visual vertical test during eccentric rotation in the recovery phase of vestibular neuritis.

    Science.gov (United States)

    Byun, Jae Yong; Hong, Seok Min; Yeo, Seung Geun; Kim, Sang Hoon; Kim, Sung Wan; Park, Moon Suh

    2010-10-01

    By assessing unilateral utricular function at the acute and subacute stages, we sought to determine the ability of the subjective visual vertical (SVV) during eccentric rotation (dynamic SVV) in detecting latent abnormality of otolith dysfunction in unilateral vestibular neuritis. In addition, we compared the validity of the dynamic SVV with static SVV during the compensated recovery phase. The static SVV and dynamic SVV of 19 patients diagnosed with acute unilateral vestibular neuritis and 31 patients diagnosed with the subacute stage of vestibular neuritis were determined in this study. First, the static SVV was measured in a dark booth without rotation. The dynamic SVV was measured during rotation with an eccentric displacement of the head to 3.5cm from the vertical rotation axis during a constant velocity of 300 degrees /s. In the acute stage of vestibular neuritis, the static SVV showed an increase in deviation to the side of the lesion compared to findings in normal subjects. In the subacute stage, it did not differ significantly from that of the normal subjects. The dynamic SVV, however, had a statistically significant increase in deviation to the side of the lesion compared to normal subjects in both the acute and subacute stages. The dynamic SVV would be an effective method in detecting latent abnormality of otolith dysfunction in unilateral vestibular neuritis, compared to static SVV, especially compensated unilateral vestibular neuritis. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  18. DEVELOPMENT OF AN EXPERIMENTAL TEST BED DESIGNATED FOR MODEL STUDIES OF AERODYNAMICS OF PREMISES USING METHOD OF DIGITAL FLOW VISUALIZATION

    Directory of Open Access Journals (Sweden)

    Varapaev Vladimir Nikolaevich

    2012-12-01

    Full Text Available In the article, the authors present their findings generated at the laboratory of aerodynamic and aero-acoustic testing of structural units of MGSU. The authors provide information about the principle of operation and a brief description of the experimental test bed designated for the physical research of patterns of air flows arising inside building premises of various geometric shapes. The authors also demonstrate the basic parameters of the test bed, the principle of operation of its recording devices and some of its characteristics. The test bed is designated for the identification of characteristics of three-dimensional flows of models under research and for the verification of results of numerical studies. The measurement bed has advanced measurement and registration units. The management principle is based on the method of digital flow visualization, PIV method and Doppler flow meter implemented in the LDA anemometer. The test stand generates two or three component vector fields of turbulent gas flow velocities. It may be applicable to the study of liquids in case of research of hydraulics-related problems. Some results of the flow study are provided in the article, as well.

  19. Wear properties of alumina/zirconia composite ceramics for joint prostheses measured with an end-face apparatus.

    Science.gov (United States)

    Morita, Yusuke; Nakata, Kenichi; Kim, Yoon-Ho; Sekino, Tohru; Niihara, Koichi; Ikeuchi, Ken

    2004-01-01

    While only alumina is applied to all-ceramic joint prostheses at present, a stronger ceramic is required to prevent fracture and chipping due to impingement and stress concentration. Zirconia could be a potential substitute for alumina because it has high strength and fracture toughness. However, the wear of zirconia/zirconia combination is too high for clinical use. Although some investigations on composite ceramics revealed that mixing of different ceramics was able to improve the mechanical properties of ceramics, there are few reports about wear properties of composite ceramics for joint prosthesis. Since acetabular cup and femoral head of artificial hip joint are finished precisely, they indicate high geometric conformity. Therefore, wear test under flat contact was carried out with an end-face wear testing apparatus for four kinds of ceramics: alumina monolith, zirconia monolith, alumina-based composite ceramic, and zirconia based composite ceramic. Mean contact pressure was 10 MPa and sliding velocity was 40 mm/s. The wear test continued for 72 hours and total sliding distance was 10 km. After the test, the wear factor was calculated. Worn surfaces were observed with a scanning electron micrograph (SEM). The results of this wear test show that the wear factors of the both composite ceramics are similarly low and their mechanical properties are much better than those of the alumina monolith and the zirconia monolith. According to these results, it is predicted that joint prostheses of the composite ceramics are safer against break down and have longer lifetime compared with alumina/alumina joint prostheses.

  20. Metallurgy, Visual Inspection, Hardness and Liquid Penetrant Testing, Aviation Quality Control 2: 9227.01.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    The course consists of the basic and simpler methods of inspecting and nondestructive testing of parts and materials to insure the quality and reliability of the finished product. The outline consists of six blocks totaling 135 hours: (1) defects in the metal ingot, (2) defects resulting from processing metals, (3) defects in metals in service,…

  1. An Exploratory Study Investigating How Adults with Intellectual Disabilities Perform on the Visual Association Test (VAT)

    Science.gov (United States)

    McPaul, Ann; Walker, Brigid; Law, Jim; McKenzie, Karen

    2017-01-01

    Background: Neuropsychological tests of memory are believed to offer the greatest sensitivity at identifying people at the risk of developing dementia. There is a paucity of standardized and appropriate neuropsychological assessments of memory for adults with an intellectual disability. This study examines how adults with an intellectual…

  2. Recognition versus Resolution: a Comparison of Visual Acuity Results Using Two Alternative Test Chart Optotype

    Directory of Open Access Journals (Sweden)

    Jonathan S. Pointer

    2008-01-01

    Conclusions: For normally sighted subjects wearing an optimal refractive correction, a bias was recorded in favour of recognition over resolution acuity: the clinical difference amounted to approximately 40% of one logMAR chart line, with similar high repeatability for either chart optotype. We conclude that the assumption of clinical equivalence between letter and Landolt acuity is reasonable under optimum test conditions.

  3. Visual Working Memory and Number Sense: Testing the Double Deficit Hypothesis in Mathematics

    Science.gov (United States)

    Toll, Sylke W. M.; Kroesbergen, Evelyn H.; Van Luit, Johannes E. H.

    2016-01-01

    Background: Evidence exists that there are two main underlying cognitive factors in mathematical difficulties: working memory and number sense. It is suggested that real math difficulties appear when both working memory and number sense are weak, here referred to as the double deficit (DD) hypothesis. Aims: The aim of this study was to test the DD…

  4. Visual pattern and serial quantitation of {sup 18}F-sodium fluoride PET/CT in asymptomatic patients after hip and knee arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Son, Hye Joo; Jeong, Young Jin; Yoon, Hyun Jin; Wang, Lih; Kim, Hyeon Jun; Kang, Do Young [Dong-A University Medical Center, Dong-A University College of Medicine, Busan (Korea, Republic of); Park, Jong Hwan [Institute of Convergence Bio-Health, Dong-A University, Busan (Korea, Republic of)

    2016-12-15

    We investigated the visual tracer distribution pattern and serial changes in uptake ratio in different anatomical zones during the natural postoperative course in order to establish a reference for evaluation of patients with complications. A total of 36 patients without symptoms after hip or knee arthroplasty were grouped according to the interval between surgery and the scan. The serial changes in SUVmean in each periprosthetic zone were quantified using the volume of interest isocontour method. Images were classified according to the uptake distribution pattern. The uptake ratios in the postoperative period groups were then compared using the Kruskal-Wallis test. The correlation between uptake ratio and postoperative period was then determined. Tracer distribution patterns in hip prostheses were classified into three types and the patterns in knee prostheses into five types. In hip prostheses, intense osteoblastic activity was observed during 3-6 months and then declined in most patients, but showed a slight increase over 15-25 months in 5-10 % of patients. The correlation coefficients varied among the zones. Significant differences in uptake ratios among the period groups was found for all zones, except zone 8. Porous coated areas showed higher uptake than uncoated areas only for the period the 3-6 months. In knee prostheses, uptake ratios showed a curvilinear pattern, increasing from 3-6 to 8-15 months and declining later. The uptake ratios were different among the period groups. Every zone showed a positive correlation from 3-6 to 8-15 months, and negative correlations from 8-15 to 22-25 months. This is the first {sup 18}F-sodium fluoride PET/CT study investigating the stability of implants and sets a reference for evaluation of patients with complications.

  5. Immediate loading of tooth-implant-supported telescopic mandibular prostheses.

    Science.gov (United States)

    Romanos, George E; May, Stephan; May, Dittmar

    2012-01-01

    Extractions in partially edentulous patients often lead to insufficient stability of an existing partial prosthesis and a need for additional anchorage. Implants may therefore be placed as supplementary abutments to increase patient comfort and satisfaction. The aim of this study was to evaluate the long-term clinical outcome of implants combined with teeth to support telescopic abutment-retained removable full-arch prostheses under an immediate functional loading protocol. The present retrospective study included implants placed and connected via removable prostheses with periodontally healthy teeth immediately postplacement using prefabricated abutments. Secondary copings, precisely fit to the abutments, were placed and the partial dentures were relined chairside. The prosthetic restorations were not removed for 10 days. Clinical and radiographic evaluations of implants loaded for at least 2 years were performed. One hundred ten implants with a progressive thread design (Ankylos, Dentsply) were placed in 55 patients (mean age, 63.51±9.95 years). Twenty-five implants were placed in fresh extraction sockets (22.73%) and 85 implants were placed in healed ridges. All implants were placed 2 to 3 mm subcrestally (measured from the midfacial bone level). After a mean follow-up of 61.58±28.47 months (range, 24 to 125 months), there were only three failures (2.73%); another six implants (5.45%) displayed crestal bone loss greater than 2 mm but remained stable. Therefore, the failure rate was 8.18% for the entire observation period of 5.13 years. The success rate was 91.82% and the cumulative survival rate was 97.27%. All patients were satisfied with the stability of their prostheses, and no prosthetic, peri-implant, or abutment tooth problems were observed. Telescopic tooth-implant-supported mandibular restorations with immediate loading present an alternative prosthetic solution for partially edentulous patients, providing a long-term predictable clinical outcome.

  6. [Functional, mechanical, and structural demands in microvascular prostheses (author's transl)].

    Science.gov (United States)

    Tizian, C H

    1980-01-01

    Fundamental conclusions can be made based on initial experimental experiences concerning microvascular prostheses. Beside having high durability, the microprostheses need to be compatible with other tissues and easy to handle. They must have a microporous structure to allow tissue ingrowth. Negative surface charge, hydrophobic property, and inertness of the synthetic material contribute to avoiding thrombosis. The isodiametric relationship between vessel and micrograft appears to create an optimal hemodynamic situation. For insertion, the use of microsurgical techniques is necessary in determining the future of the implanted micrograft. By performing everting continuous over-and-over suture, the end-to-end anastomosis showed excellent results.

  7. Heart valve prostheses: who protects our patients, and from what?

    Science.gov (United States)

    Beall, A C

    1977-01-01

    Phenomenal advances in the development of cardiac valve prostheses have taken place in less than two decades. However, the currently prevailing atmosphere of consumer protectionism in existence 20 years ago probably would have made such developments impossible. Recent passage of the Medical Device Amendments of 1976 (P.L. 94-295) will not only make future development extremely difficult, but also may force the field of cardiac valve replacement back into the era of the 1950s. Regulations implementing this legislation may be even more disastrous. It is time for someone to protect patients from their so-called protectors.

  8. Provisional prostheses during ridge augmentation and implant dentistry.

    Science.gov (United States)

    Livada, Rania; Hottel, Timothy L; Shiloah, Jacob

    2013-01-01

    Recent advancements in ridge augmentation and bone regeneration have expanded the pool of patients that could benefit from dental implants. However, providing the patient with a temporary prosthesis during the wound healing phase without impairing the process is a challenging task. This article summarizes available information pertaining to provisional prostheses, both tooth-supported and soft tissue-supported, that may meet the patient needs. The advantages and disadvantages of each class of prosthesis, along with indications and contraindications, were taken into consideration to aid the restorative dentist in choosing the optimal provisional for their patients.

  9. Comparison of visual field test results obtained through Humphrey matrix frequency doubling technology perimetry versus standard automated perimetry in healthy children

    Directory of Open Access Journals (Sweden)

    Sibel Kocabeyoglu

    2013-01-01

    Full Text Available Aims : The aim of this study was to compare the visual field test results in healthy children obtained via the Humphrey matrix 24-2 threshold program and standard automated perimetry (SAP using the Swedish interactive threshold algorithm (SITA-Standard 24-2 test. Materials and Methods: This prospective study included 55 healthy children without ocular or systemic disorders who underwent both SAP and frequency doubling technology (FDT perimetry visual field testing. Visual field test reliability indices, test duration, global indices (mean deviation [MD], and pattern standard deviation [PSD] were compared between the 2 tests using the Wilcoxon signed-rank test and paired t-test. The performance of the Humphrey field analyzer (HFA 24-2 SITA-standard and frequency-doubling technology Matrix 24-2 tests between genders were compared with Mann-Whitney U-test. Results: Fifty-five healthy children with a mean age of 12.2 ± 1.9 years (range from 8 years to 16 years were included in this prospective study. The test durations of SAP and FDT were similar (5.2 ± 0.5 and 5.1 ± 0.2 min, respectively, P = 0.651. MD and the PSD values obtained via FDT Matrix were significantly higher than those obtained via SAP (P < 0.001, and fixation losses and false negative errors were significantly less with SAP (P < 0.05. A weak positive correlation between the two tests in terms of MD (r = 0.352, P = 0.008 and PSD (r = 0.329, P = 0.014 was observed. Conclusion: Children were able to complete both the visual test algorithms successfully within 6 min. However, SAP testing appears to be associated with less depression of the visual field indices of healthy children. FDT Matrix and SAP should not be used interchangeably in the follow-up of children.

  10. Chemical and Structural Characterization of Several Mid-Term Explanted Breast Prostheses

    Directory of Open Access Journals (Sweden)

    Angela Amoresano

    2016-08-01

    Full Text Available The recent scandal of poly implant prostheses (PIP, which were found in some cases to be made of non-medical grade silicone (as reported by the European Scientific Committee on Emerging and Newly Identified Health Risks, had a great social impact. Thousands of patients asked for implant removal with significant costs for public health care systems. We analysed, by a multidisciplinary approach, sixteen different breast implants after explantation by using several analytical and structural techniques, such as Fourier Transform infrared spectroscopy (FT-IR, mass spectrometry equipped by ion coupled plasma (ICP-MS, gas-chromatography (GC-MS, and tensile testing. Traces of organic (fatty acid and inorganic (Fe, Cr, Pt, Na, and other metals substances were found in all samples, and, even if these values are under danger threshold levels, our study results highlight the possibility of bioaccumulation and tissue contamination, implying the need for continuous medical surveillance and monitoring of material aging.

  11. EPRI/DOE High-Burnup Fuel Sister Rod Test Plan Simplification and Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Saltzstein, Sylvia J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorenson, Ken B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hanson, B. D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shimskey, R. W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Klymyshyn, N. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Webster, R. A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jensen, P. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); MacFarlan, P. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Billone, Mike [Argonne National Lab. (ANL), Argonne, IL (United States); Scaglione, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Montgomery, Rose [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bevard, Bruce [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-15

    The EPRI/DOE High-Burnup Confirmatory Data Project (herein called the “Demo”) is a multi-year, multi-entity test with the purpose of providing quantitative and qualitative data to show if high-burnup fuel mechanical properties change in dry storage over a ten-year period. The Demo involves obtaining 32 assemblies of high-burnup PWR fuel of common cladding alloys from the North Anna Nuclear Power Plant, loading them in an NRC-licensed TN-32B cask, drying them according to standard plant procedures, and then storing them on the North Anna dry storage pad for ten years. After the ten-year storage time, the cask will be opened and the mechanical properties of the rods will be tested and analyzed.

  12. 'Who is the ideal candidate?': decisions and issues relating to visual neuroprosthesis development, patient testing and neuroplasticity

    Science.gov (United States)

    Merabet, Lotfi B.; Rizzo, Joseph F., III; Pascual-Leone, Alvaro; Fernandez, Eduardo

    2007-03-01

    Appropriate delivery of electrical stimulation to intact visual structures can evoke patterned sensations of light in individuals who have been blind for many years. This pivotal finding has lent credibility to the concept of restoring functional vision by artificial means. As numerous groups worldwide pursue human clinical testing with visual prosthetic devices, it is becoming increasingly clear that there remains a considerable gap between the challenges of prosthetic device development and the rehabilitative strategies needed to implement this new technology in patients. An important area of future work will be the development of appropriate pre- and post-implantation measures of performance and establishing candidate selection criteria in order to quantify technical advances, guide future device design and optimize therapeutic success. We propose that the selection of an 'ideal' candidate should also be considered within the context of the variable neuroplastic changes that follow vision loss. Specifically, an understanding of the adaptive and compensatory changes that occur within the brain could assist in guiding the development of post-implantation rehabilitative strategies and optimize behavioral outcomes.

  13. Determining student teachers' perceptions on using technology via Likert scale, visual association test and metaphors: A mixed study

    Directory of Open Access Journals (Sweden)

    Mevhibe Kobak

    2013-04-01

    Full Text Available The aim of this study is to determine senior student teachers’ perceptions on using technology by approaching various points of view. In this study, researchers collected data through Technology Perceptions Scale, Visual Association Activity and Technology Metaphors. The participants of the study were 104 senior student teachers who were enrolled in Balıkesir University Necatibey Faculty of Education. In this descriptive study, researchers interpreted qualitative data in conjunction with quantitative data. Based on the data obtained, even though student teachers’ perceptions on using technology were found positive in the light of Likert scale, there was no significant relation in terms of gender and enrolled undergraduate program. According to the results of visual association test, student teachers ranked smartboard, Internet and computer in the first three, and portable media player, mobile phone and video/camera in the last three. Besides, researchers analyzed and classified student teachers’ metaphors about technology under 9 categories: 1developing-changing technology, 2rapidly progressing technology, 3 limitless-endless technology, 4beneficial technology, 5harmful technology, 6both beneficial and harmful technology, 7indispensible technology, 8technology as a necessity, 9 all-inclusive technology. At the end of the study, those nine categories which were acquired using the content analysis technique are presented in a table which shows the interaction between categories in a holistic view.

  14. Interrelationships between visual-motor integration, visual ...

    African Journals Online (AJOL)

    The Developmental Test of Visual-Motor Integration (4th ed.) (VMI), was used to evaluate visual skills, while the Test of Gross Motor Development-2 evaluated six object control skills. There was a statistical significant (p≤0.01) association between VMI, two object control skills and total score for object control skills. Visual ...

  15. Detection of progression of glaucomatous visual field damage using the point-wise method with the binomial test.

    Science.gov (United States)

    Karakawa, Ayako; Murata, Hiroshi; Hirasawa, Hiroyo; Mayama, Chihiro; Asaoka, Ryo

    2013-01-01

    To compare the performance of newly proposed point-wise linear regression (PLR) with the binomial test (binomial PLR) against mean deviation (MD) trend analysis and permutation analyses of PLR (PoPLR), in detecting global visual field (VF) progression in glaucoma. 15 VFs (Humphrey Field Analyzer, SITA standard, 24-2) were collected from 96 eyes of 59 open angle glaucoma patients (6.0 ± 1.5 [mean ± standard deviation] years). Using the total deviation of each point on the 2(nd) to 16(th) VFs (VF2-16), linear regression analysis was carried out. The numbers of VF test points with a significant trend at various probability levels (pbinomial test (one-side). A VF series was defined as "significant" if the median p-value from the binomial test was binomial PLR method (0.14 to 0.86) was significantly higher than MD trend analysis (0.04 to 0.89) and PoPLR (0.09 to 0.93). The PIS of the proposed method (0.0 to 0.17) was significantly lower than the MD approach (0.0 to 0.67) and PoPLR (0.07 to 0.33). The PBNS of the three approaches were not significantly different. The binomial BLR method gives more consistent results than MD trend analysis and PoPLR, hence it will be helpful as a tool to 'flag' possible VF deterioration.

  16. Monoscopic photogrammetry to obtain 3D models by a mobile device: a method for making facial prostheses.

    Science.gov (United States)

    Salazar-Gamarra, Rodrigo; Seelaus, Rosemary; da Silva, Jorge Vicente Lopes; da Silva, Airton Moreira; Dib, Luciano Lauria

    2016-05-25

    The aim of this study is to present the development of a new technique to obtain 3D models using photogrammetry by a mobile device and free software, as a method for making digital facial impressions of patients with maxillofacial defects for the final purpose of 3D printing of facial prostheses. With the use of a mobile device, free software and a photo capture protocol, 2D captures of the anatomy of a patient with a facial defect were transformed into a 3D model. The resultant digital models were evaluated for visual and technical integrity. The technical process and resultant models were described and analyzed for technical and clinical usability. Generating 3D models to make digital face impressions was possible by the use of photogrammetry with photos taken by a mobile device. The facial anatomy of the patient was reproduced by a *.3dp and a *.stl file with no major irregularities. 3D printing was possible. An alternative method for capturing facial anatomy is possible using a mobile device for the purpose of obtaining and designing 3D models for facial rehabilitation. Further studies must be realized to compare 3D modeling among different techniques and systems. Free software and low cost equipment could be a feasible solution to obtain 3D models for making digital face impressions for maxillofacial prostheses, improving access for clinical centers that do not have high cost technology considered as a prior acquisition.

  17. Value of scintigraphy with Cuban 99mTc-ciprofloxacin in the detection of infected hip prostheses

    International Nuclear Information System (INIS)

    Marrero Riveron, Luis O; Alvarez Cambras, Rodrigo; Hernandez Cairo, Abel; Batista Cuellar, Juan F; Guerra Ordonnez, Carlos Alberto; Perera Pintado, Alejandro

    2006-01-01

    An experimental, analytical cross-sectional study was conducted in 15 patients with suspicion of infectious process that were referred to 'Frank Pais' International Scientific Orthopedic Complex from January 1st, 2003 to December 31st, 2004, aimed at determining the efficacy of the Cuban 99mTc-ciprofloxacin in the evaluation of bacterial infections of the hip prostheses. Bone scintigraphies with 99mTc-methylendiphosphonate and 99mTc-ciprofloxacin were performed at 1, 4 and 24 hours after the injection. The culture/biopsy was used to confirm the criteria. On the visual analysis of the patients, sensitivity was obtained in 100 %, specificity in 75 %, diagnostic accuracy in 93.3 %, positive predictive value in 91.6 %, and negative predictive value in 100 %. The injured/healthy ratio showed significant differences between the patients with and without infection at the diverse hours of acquisition, with a level of significance of a = 0.05. The effectiveness of the Cuban formulation of 99mTc-ciprofloxacin in the evaluation of bacterial infections of the hip prostheses was proved

  18. Biofilm formation on voice prostheses : Influence of dairy products in vitro

    NARCIS (Netherlands)

    Free, RH; Van der Mei, HC; Dijk, F; Van Weissenbruch, R; Busscher, HJ; Albers, FWJ

    2001-01-01

    Laryngectomized patients use silicone rubber voice prostheses to regain their speech: however. the lifetime of these devices is limited due to biofilm formation. Following anecdotal evidence. the influence of various dairy products on biofilm formation on voice prostheses was studied, using the

  19. The sense or nonsense of mobile-bearing total knee prostheses

    NARCIS (Netherlands)

    Wolterbeek, Nienke

    2011-01-01

    The focus of this thesis was if the in vivo kinematics of total knee prostheses was consistent with the kinematics intended by design and to determine the additional value of insert mobility and thus ‘the sense or nonsense’ of mobile-bearing knee prostheses. The added value of this thesis to the

  20. A study of technical changes to lower limb prostheses after initial fitting

    NARCIS (Netherlands)

    Rommers, GM; Vos, LDW; Klein, L; Groothoff, JW; Eisma, W H

    There is little published material in recent years about the use of lower limb prostheses in an elderly amputee population. In this study the authors were interested in the technical changes to lower limb prostheses after a first limb fitting procedure in a post-rehabilitation population in the

  1. In vivo fragmentation of microporous polyurethane- and copolyester elastomer-based vascular prostheses

    NARCIS (Netherlands)

    Hinrichs, W.L.J.; Hinrichs, W.L.J.; Kuit, J.; Feil, H.; Feil, H.; Wildevuur, Ch.R.H.; Feijen, Jan

    1992-01-01

    A previous study showed that microporous, compliant and (bio)degradable vascular prostheses prepared from a polyurethane/poly(-lactic acid) mixture can function as a temporary scaffold for the regeneration of small-calibre arteries. In this study the mechanism of fragmentation of vascular prostheses

  2. Methods used for assessing stresses in buccomaxillary prostheses: photoelasticity, finite element technique, and extensometry.

    Science.gov (United States)

    Goiato, Marcelo Coelho; Tonella, Bianca Piccolotto; Ribeiro, Paula do Prado; Ferraço, Renato; Pellizzer, Eduardo Piza

    2009-03-01

    The authors describe a literature revision on assessing stresses in buccomaxillary prostheses photoelasticity, finite element technique, and extensometry. They describe the techniques and the importance for use of each method in buccomaxillary prostheses with implants and the need of accomplishing more studies in this scarce literary area.

  3. Recovering a "Disfigured"¹ Face: Cosmesis in the Everyday Use of Facial Prostheses

    NARCIS (Netherlands)

    Yaron, Gili; Widdershoven, G.A.M.; Slatman, Jenny

    2017-01-01

    Prosthetic devices that replace an absent body part are generally considered to be either cosmetic or functional. Functional prostheses aim to restore (some degree of) lost physical functioning. Cosmetic prostheses attempt to restore a “normal” appearance to bodies that lack (one or more) limbs by

  4. Movement characteristics of upper extremity prostheses during basic goal-directed tasks

    NARCIS (Netherlands)

    Bouwsema, Hanneke; van der Sluis, Corry K.; Bongers, Raoul M.

    Background: After an upper limb amputation a prosthesis is often used to restore the functionality. However, the frequency of prostheses use is generally low. Movement kinematics of prostheses use might suggest origins of this low use. The aim of this study was to reveal movement patterns of

  5. Movement characteristics of upper extremity prostheses during basic goal-directed tasks.

    Science.gov (United States)

    Bouwsema, Hanneke; van der Sluis, Corry K; Bongers, Raoul M

    2010-07-01

    After an upper limb amputation a prosthesis is often used to restore the functionality. However, the frequency of prostheses use is generally low. Movement kinematics of prostheses use might suggest origins of this low use. The aim of this study was to reveal movement patterns of prostheses during basic goal-directed actions in upper limb prosthetic users and to compare this with existing knowledge of able-bodied performance during these actions. Movements from six users of upper extremity prostheses were analyzed, three participants with a hybrid upper arm prosthesis, and three participants with a myoelectric forearm prosthesis. Two grasping tasks and a reciprocal pointing task were investigated during a single lab session. Analyses were carried out on the kinematics of the tasks. When grasping, movements with both prostheses showed asymmetric velocity profiles of the reach and had a plateau in the aperture profiles. Reach and grasp were decoupled. Kinematics with the prostheses differed in that the use of upper arm prostheses required more time to execute the movements, while the movements were less smooth, more asymmetric, and showed more decoupling between reach and grasp. The pointing task showed for both prostheses less harmonic movements with higher task difficulty. Characterizing prosthetic movement patterns revealed specific features of prosthetic performance. Developments in technology and rehabilitation should focus on these issues to improve prosthetic use, in particular on improving motor characteristics and the control of the elbow, and learning to coordinate the reach and the grasp component in prehension. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  6. Differences in aerodynamic characteristics of new and dysfunctional Provox (R) 2 voice prostheses in vivo

    NARCIS (Netherlands)

    Schwandt, LQ; Tjong-Ayong, HJ; van Weissenbruch, R; der Mei, HC; Albers, FWJ

    Tracheoesophageal voice prostheses need to be replaced due to increased airflow resistance or retrograde leakage of fluid into the trachea as a consequence of biofilm formation. Previous in vitro studies show a change of aerodynamic features of biofilm covered voice prostheses after removal of the

  7. Antifungal activity of components used for decontamination of dental prostheses on the growth of Candida albicans

    Directory of Open Access Journals (Sweden)

    Cíntia Lima Gouveia

    Full Text Available Introduction: The effectiveness of antimicrobial solutions employed in dental prosthesis decontamination is still uncertain. Aim: To evaluate the antifungal activity of cleaners used in the decontamination of dental prostheses on the growth of Candida albicans. Material and method: The evaluated products were: Corega Tabs(r (S1, Sodium Hypochlorite 1% (S2, Sodium Bicarbonate 1% (S3, Hydrogen Peroxide 1% (S4, Chlorhexidine Digluconate 0.12% - Periogard (r (S5, Mouthrinse based on essential oils - Listerine(r (S6, essential oil from Rosmarinus officinalis (rosemary at concentrations of 1% (S7 and 2% (S8. The antifungal activity of the products was evaluated by agar diffusion technique and the determination of microbial death curve of samples of C. albicans (ATCC 90028 in concentration 1.5 × 106 CFU/mL. The tests were performed in triplicate and statistical analysis was made by ANOVA Two-Way and Tukey tests, with the confidence level of 95%. Result: The average of the zones of inhibition growth, in millimeters, obtained for the products were: 0.0 (S1, 44.7 (S2, 0.0 (S3, 21.6 (S4, 10.0 (S5, 6.1 (S6, 0.0 (S7 and 2.4 (S8. Considering the determination of microbial death curve, all products showed a statistical difference (p<0.01 from control (0.85% sodium chloride and S3 groups. Fungal growth less than 2×104 CFU/mL and an accentuation of the microbial death curve were observed after 30 minutes, with exception for S3 and control groups. Conclusion: The studied compounds, with the exception of Sodium Bicarbonate, have antifungal effect against C. albicans, which contribute for dental prostheses hygiene.

  8. VRP09 Objective Methods to Test Visual Dysfunction in the Presence of Cognitive Impairment

    Science.gov (United States)

    2014-10-01

    Ischaemic   stroke :  the  ocular  motor  system  as  a  sensitive  marker  for  motor...greater difficulty to stay fixated on a fixation target during stimulation of a diseased eye. Significance: objective tests of vision will greatly...optic  nerve  input  between  the   two  eyes  due  to   disease .  We  found  a  very  high  correlation

  9. Exploring cognitive motor interference in multiple sclerosis by the visual Stroop test.

    Science.gov (United States)

    Coghe, Giancarlo; Pilloni, Giuseppina; Zucca, Erica; Porta, Micaela; Corona, Federica; Frau, Jessica; Fenu, Giuseppe; Lorefice, Lorena; Marrosu, Maria Giovanna; Pau, Massimiliano; Cocco, Eleonora

    2018-02-24

    The dual task paradigm (the simultaneous performance of motor and cognitive task) is used in a laboratory setting to evaluate walking impairments that affect patients' daily lives. Although promising, it is poorly standardized and neither the cognitive task nor the motor task have been validated in a matched healthy control group (HC) for multiple sclerosis (MS). Our aim was to set up a standardized instrument to evaluate cognitive motor interference in MS using the interference test par excellence: the stroop colour word test (SCWT). Patients with MS and HC underwent 3D gait analysis with a dual task protocol, using the SCWT as a cognitive task. Gait performance impairment during the dual task was evaluated by dual task cost (DTC). A MANOVA was used to verify the effect of status (MS, HC) on DTC, calculated for the spatiotemporal parameter of the gait. In MS, the DTC was higher for the following gait parameters: speed (p = .013), cadence (p = .004), stride time (p = .005) stance phase (p cognitive motor interference in MS. Copyright © 2018. Published by Elsevier B.V.

  10. Effect of probiotic bacteria on prevalence of yeasts in oropharyngeal biofilms on silicone rubber voice prostheses in vitro

    NARCIS (Netherlands)

    van der Mei, HC; Free, RH; Elving, GJ; Van Weissenbruch, R; Albers, FWJ; Busscher, HJ

    The proliferation of yeasts in the mixed bacterial and fungal biofilms colonising silicone rubber voice prostheses in laryngectomised patients is the main cause of malfunctioning of the valve mechanism on the oesophageal side of the prostheses. Indwelling voice prostheses usually have to be replaced

  11. Titania nanotube arrays as interfaces for neural prostheses

    Energy Technology Data Exchange (ETDEWEB)

    Sorkin, Jonathan A. [Department of Mechanical Engineering, Colorado State University, Fort Collins CO 80523 (United States); Hughes, Stephen [Department of Chemical and Biological Engineering, Colorado State University, Fort Collins CO 80523 (United States); School of Biomedical Engineering, Colorado State University, Fort Collins CO 80523 (United States); Soares, Paulo [Department of Mechanical Engineering, Polytechnic School, Pontifícia Universidade Católica do Paraná, Curitiba, PR 80215-901 (Brazil); Popat, Ketul C., E-mail: ketul.popat@colostate.edu [Department of Mechanical Engineering, Colorado State University, Fort Collins CO 80523 (United States); School of Biomedical Engineering, Colorado State University, Fort Collins CO 80523 (United States)

    2015-04-01

    Neural prostheses have become ever more acceptable treatments for many different types of neurological damage and disease. Here we investigate the use of two different morphologies of titania nanotube arrays as interfaces to advance the longevity and effectiveness of these prostheses. The nanotube arrays were characterized for their nanotopography, crystallinity, conductivity, wettability, surface mechanical properties and adsorption of key proteins: fibrinogen, albumin and laminin. The loosely packed nanotube arrays fabricated using a diethylene glycol based electrolyte, contained a higher presence of the anatase crystal phase and were subsequently more conductive. These arrays yielded surfaces with higher wettability and lower modulus than the densely packed nanotube arrays fabricated using water based electrolyte. Further the adhesion, proliferation and differentiation of the C17.2 neural stem cell line was investigated on the nanotube arrays. The proliferation ratio of the cells as well as the level of neuronal differentiation was seen to increase on the loosely packed arrays. The results indicate that loosely packed nanotube arrays similar to the ones produced here with a DEG based electrolyte, may provide a favorable template for growth and maintenance of C17.2 neural stem cell line. - Highlights: • Titania nanotube arrays can be fabricated with to have loosely or densely packed morphologies. • Titania nanotube arrays support higher C17.2 neural stem cell adhesion and proliferation. • Titania nanotube arrays support higher C17.2 neural stem cell differentiation towards neuronal lineage.

  12. Titania nanotube arrays as interfaces for neural prostheses.

    Science.gov (United States)

    Sorkin, Jonathan A; Hughes, Stephen; Soares, Paulo; Popat, Ketul C

    2015-04-01

    Neural prostheses have become ever more acceptable treatments for many different types of neurological damage and disease. Here we investigate the use of two different morphologies of titania nanotube arrays as interfaces to advance the longevity and effectiveness of these prostheses. The nanotube arrays were characterized for their nanotopography, crystallinity, conductivity, wettability, surface mechanical properties and adsorption of key proteins: fibrinogen, albumin and laminin. The loosely packed nanotube arrays fabricated using a diethylene glycol based electrolyte, contained a higher presence of the anatase crystal phase and were subsequently more conductive. These arrays yielded surfaces with higher wettability and lower modulus than the densely packed nanotube arrays fabricated using water based electrolyte. Further the adhesion, proliferation and differentiation of the C17.2 neural stem cell line was investigated on the nanotube arrays. The proliferation ratio of the cells as well as the level of neuronal differentiation was seen to increase on the loosely packed arrays. The results indicate that loosely packed nanotube arrays similar to the ones produced here with a DEG based electrolyte, may provide a favorable template for growth and maintenance of C17.2 neural stem cell line. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Oral Implant-Prostheses: New Teeth for a Brighter Brain.

    Directory of Open Access Journals (Sweden)

    Vincenzo De Cicco

    Full Text Available Several studies have demonstrated that chewing can be regarded as a preventive measure for cognitive impairment, whereas masticatory deficiency, associated with soft-diet feeding, is a risk factor for the development of dementia. At present the link between orofacial sensorimotor activity and cognitive functions is unknown. In subjects with unilateral molar loss we have shown asymmetries in both pupil size and masticatory muscles electromyographic (EMG activity during clenching: the molar less side was characterized by a lower EMG activity and a smaller pupil. Since implant-prostheses, greatly reduced both the asymmetry in EMG activity and in pupil's size, trigeminal unbalance, leading to unbalance in the activity of the Locus Coeruleus (LC, may be responsible for the pupil's asymmetry. According to the findings obtained in animal models, we propose that the different activity of the right and left LC may induce an asymmetry in brain activity, thus leading to cognitive impairment. According to this hypothesis, prostheses improved the performance in a complex sensorimotor task and increased the mydriasis associated with haptic tasks. In conclusion, the present study indicates that the implant-prosthesis therapy, which reduces the unbalance of trigeminal proprioceptive afferents and the asymmetry in pupil's size, may improve arousal, boosting performance in a complex sensorimotor task.

  14. Datos normativos para el test de Span Visual: estudio evolutivo de la memoria de trabajo visual y la memoria de trabajo verbal

    Directory of Open Access Journals (Sweden)

    Sergio Hernández

    2012-06-01

    Full Text Available El objetivo central del presente trabajo ha sido la baremación en una amplia muestra de población infantil de una prueba destinada a la evaluación de la memoria de trabajo visual. Además, hemos abordado el estudio del desarrollo evolutivo de la memoria de trabajo verbal y la memoria de trabajo visual. Se seleccionó a una muestra de 1.030 sujetos con edades comprendidas entre los 6 años y 3 meses y los 12 años y 4 meses que cursaban entre primero y sexto de educación primaria. Las pruebas utilizadas fueron: el Span Visual de la Wechsler Memory Scale, tanto en su versión directa como inversa, para la memoria de trabajo visual y la adaptación al español de la prueba de Memoria de Frases de Siegel y Ryan para la memoria de trabajo verbal. Los resultados encontrados ponen de manifiesto una mejora progresiva en el rendimiento en función de la edad en ambas pruebas. Se presentan tablas de medias, desviación estándar y percentiles para los distintos grupos de edad. Estos datos podrán ser utilizados como referencia normativa por aquellos profesionales interesados en el estudio del funcionamiento ejecutivo de la población escolar infantil.

  15. [Application of negative molds technology based on three-dimensional printing in digital maxillofacial prostheses].

    Science.gov (United States)

    Gu, X Y; Chen, X B; Jiao, T; Zhang, F Q; Jiang, X Q

    2017-06-09

    Objective: To explore a digital negative molds technique based on three-dimensional (3D) printing to assist in the manufacture of maxillofacial prostheses, and to improve the deficiency of the current clinical treatment. Methods: Seventeen patients with maxillofacial defects (including nasal defects, orbital defects, cheek defects, auricle defect) were scanned by means of facial optical scanning and computer tomography (CT). The 3D models were then reconstructed and global registration was made to merge the reconstructed models into a new digital model for 3D design. The 3D design of the prostheses was implemented in software. The mechanical connection structure was designed by forward engineering technology for 3 patients with intra-oral defects in maxilla who needed to make removable partial dentures, so that the silicone prostheses and removable partial denture could be combined. The removable partial dentures were made by conventional method and connected with the prostheses. According to the 3D data of the prostheses, the digital negative molds were designed, and the 3D printing technology was used to finish the processing of the resin molds. Silicone for prostheses were filled and cured in the resin molds to fabricate the clinical restorations for the patients. The margin adaptation and retention of the prostheses was detected. Results: Twenty patients with varying degrees of maxillofacial defects were rehabilitated using the courses developed in the study. All patients reported no pain or discomfort during the treatment; and they were satisfied with the final prostheses of the shape, color, retention, stability, etc. Eighteen of the prostheses showed good marginal adaptation, and sixteen of the prostheses showed good retention effect. Conclusions: The digital negative molds technique used in this study could greatly reduce the intensity of manual operation and provided a good therapeutic effect for patients with maxillofacial defects.

  16. Mayo's Older Americans Normative Studies: Age- and IQ-Adjusted Norms for the Auditory Verbal Learning Test and the Visual Spatial Learning Test.

    Science.gov (United States)

    Steinberg, Brett A; Bieliauskas, Linas A; Smith, Glenn E; Ivnik, Robert J; Malec, James F

    2005-01-01

    Although normative data sets for standardized neuropsychometric instruments frequently feature adjustments for subject variables, there are reasons to believe that improvements in interpretive accuracy that result from such adjustments are less than optimal. In particular, years of education may be less closely associated with test performances than is overall intellectual functioning. In this last of four reanalyses of results from the Mayo Clinic's Older Americans Normative Studies (MOANS) databases, age-adjusted scores for the Rey Auditory Verbal Learning Test and the Visual Spatial Learning Test were found to be more strongly related to Mayo age-adjusted WAIS-R Full Scale IQ scores (rs=.150 to .395) than to education (rs=.060 to .236) for healthy older examinees between 56 and 99 years of age. Although AVLT-FSIQ correlations were greatest at moderate levels of intelligence, VSLT-FSIQ correlations consistently increased in strength as intelligence increased (cf. Dodrill, 19971999). Based on these results, we present tables of age- and IQ-adjusted percentile equivalents of Mayo age-adjusted AVLT index scores and MOANS age-adjusted AVLT and VSLT scaled scores for ten age ranges and either seven (AVLT) or five (VSLT) IQ ranges.

  17. Ability or Access-Ability: Differential Item Functioning of Items on Alternate Performance-Based Assessment Tests for Students with Visual Impairments

    Science.gov (United States)

    Zebehazy, Kim T.; Zigmond, Naomi; Zimmerman, George J.

    2012-01-01

    Introduction: This study investigated differential item functioning (DIF) of test items on Pennsylvania's Alternate System of Assessment (PASA) for students with visual impairments and severe cognitive disabilities and what the reasons for the differences may be. Methods: The Wilcoxon signed ranks test was used to analyze differences in the scores…

  18. Comparison on testability of visual acuity, stereo acuity and colour vision tests between children with learning disabilities and children without learning disabilities in government primary schools.

    Science.gov (United States)

    Abu Bakar, Nurul Farhana; Chen, Ai-Hong

    2014-02-01

    Children with learning disabilities might have difficulties to communicate effectively and give reliable responses as required in various visual function testing procedures. The purpose of this study was to compare the testability of visual acuity using the modified Early Treatment Diabetic Retinopathy Study (ETDRS) and Cambridge Crowding Cards, stereo acuity using Lang Stereo test II and Butterfly stereo tests and colour perception using Colour Vision Test Made Easy (CVTME) and Ishihara's Test for Colour Deficiency (Ishihara Test) between children in mainstream classes and children with learning disabilities in special education classes in government primary schools. A total of 100 primary school children (50 children from mainstream classes and 50 children from special education classes) matched in age were recruited in this cross-sectional comparative study. The testability was determined by the percentage of children who were able to give reliable respond as required by the respective tests. 'Unable to test' was defined as inappropriate response or uncooperative despite best efforts of the screener. The testability of the modified ETDRS, Butterfly stereo test and Ishihara test for respective visual function tests were found lower among children in special education classes ( P learning disabilities. Modifications of vision testing procedures are essential for children with learning disabilities.

  19. Development of a test for recording both visual and auditory reaction times, potentially useful for future studies in patients on opioids therapy.

    Science.gov (United States)

    Miceli, Luca; Bednarova, Rym; Rizzardo, Alessandro; Samogin, Valentina; Della Rocca, Giorgio

    2015-01-01

    Italian Road Law limits driving while undergoing treatment with certain kinds of medication. Here, we report the results of a test, run as a smartphone application (app), assessing auditory and visual reflexes in a sample of 300 drivers. The scope of the test is to provide both the police force and medication-taking drivers with a tool that can evaluate the individual's capacity to drive safely. The test is run as an app for Apple iOS and Android mobile operating systems and facilitates four different reaction times to be assessed: simple visual and auditory reaction times and complex visual and auditory reaction times. Reference deciles were created for the test results obtained from a sample of 300 Italian subjects. Results lying within the first three deciles were considered as incompatible with safe driving capabilities. Performance is both age-related (r>0.5) and sex-related (female reaction times were significantly slower than those recorded for male subjects, Pdeveloped and fine-tuned a test called Safedrive that measures visual and auditory reaction times through a smartphone mobile device; the scope of the test is two-fold: to provide a clinical tool for the assessment of the driving capacity of individuals taking pain relief medication; to promote the sense of social responsibility in drivers who are on medication and provide these individuals with a means of testing their own capacity to drive safely.

  20. 3D visualization of deformation structures and potential fluid pathways at the Grimsel Test Site

    Science.gov (United States)

    Schneeberger, Raphael; Kober, Florian; Berger, Alfons; Spillmann, Thomas; Herwegh, Marco

    2015-04-01

    Knowledge on the ability of fluids to infiltrate subsurface rocks is of major importance for underground constructions, geothermal or radioactive waste disposal projects. In this study, we focus on the characterization of water infiltration pathways, their 3D geometries and origins. Based on surface and subsurface mapping in combination with drill core data, we developed by the use of MoveTM (Midland Valley Exploration Ltd.) a 3D structural model of the Grimsel Test Site (GTS). GTS is an underground laboratory operated by NAGRA, the Swiss organisation responsible for the management of nuclear waste. It is located within a suite of post-Variscan magmatic bodies comprising former granitic and granodioritic melts, which are dissected by mafic and aplitic dikes. During Alpine orogeny, the suite was tectonically overprinted within two stages of ductile deformation (Wehrens et al., in prep.) followed by brittle overprint of some of the shear zones during the retrograde exhumation history. It is this brittle deformation, which controls today's water infiltration network. However, the associated fractures, cataclasites and fault gouges are controlled themselves by aforementioned pre-existing mechanical discontinuities, whose origin ranges back as far as to the magmatic stage. For example, two sets of vertically oriented mafic dikes (E-W and NW-SE striking) and compositional heterogeneities induced by magmatic segregation processes in the plutonic host rocks served as nucleation sites for Alpine strain localization. Subsequently, NE-SW, E-W and NW-SE striking ductile shear zones were formed, in combination with high temperature fracturing while dissecting the host rocks in a complex 3D pattern (Wehrens et al, in prep.). Whether the ductile shear zones have been subjected to brittle reactivation and can serve as infiltration pathways or not, depends strongly on their orientations with respect to the principal stress field. Especially where deformation structures intersect

  1. The role of long-term memory in a test of visual working memory: Proactive facilitation but no proactive interference.

    Science.gov (United States)

    Oberauer, Klaus; Awh, Edward; Sutterer, David W

    2017-01-01

    We report 4 experiments examining whether associations in visual working memory are subject to proactive interference from long-term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of 3 concrete objects in an array. Each array in the WM test consisted of 1 old (previously learned) object with a new color (old-mismatch), 1 old object with its old color (old-match), and 1 new object. Experiments 1 to 3 showed that WM performance was better in the old-match condition than in the new condition, reflecting a beneficial contribution from LTM. In the old-mismatch condition, participants sometimes reported colors associated with the relevant shape in LTM, but the probability of successful recall was equivalent to that in the new condition. Thus, information from LTM only intruded in the absence of reportable information in WM. Experiment 4 tested for, and failed to find, proactive interference from the preceding trial in the WM test: Performance in the old-mismatch condition, presenting an object from the preceding trial with a new color, was equal to performance with new objects. Experiment 5 showed that long-term memory for object-color associations is subject to proactive interference. We conclude that the exchange of information between LTM and WM appears to be controlled by a gating mechanism that protects the contents of WM from proactive interference but admits LTM information when it is useful. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  2. Development and testing of an automated computer tablet-based method for self-testing of high and low contrast near visual acuity in ophthalmic patients.

    Science.gov (United States)

    Aslam, Tariq M; Parry, Neil R A; Murray, Ian J; Salleh, Mahani; Col, Caterina Dal; Mirza, Naznin; Czanner, Gabriela; Tahir, Humza J

    2016-05-01

    Many eye diseases require on-going assessment for optimal management, creating an ever-increasing burden on patients and hospitals that could potentially be reduced through home vision monitoring. However, there is limited evidence for the utility of current applications and devices for this. To address this, we present a new automated, computer tablet-based method for self-testing near visual acuity (VA) for both high and low contrast targets. We report on its reliability and agreement with gold standard measures. The Mobile Assessment of Vision by intERactIve Computer (MAVERIC) system consists of a calibrated computer tablet housed in a bespoke viewing chamber. Purpose-built software automatically elicits touch-screen responses from subjects to measure their near VA for either low or high contrast acuity. Near high contrast acuity was measured using both the MAVERIC system and a near Landolt C chart in one eye for 81 patients and low contrast acuity using the MAVERIC system and a 25 % contrast near EDTRS chart in one eye of a separate 95 patients. The MAVERIC near acuity was also retested after 20 min to evaluate repeatability. Repeatability of both high and low contrast MAVERIC acuity measures, and their agreement with the chart tests, was assessed using the Bland-Altman comparison method. One hundred and seventy-three patients (96 %) completed the self- testing MAVERIC system without formal assistance. The resulting MAVERIC vision demonstrated good repeatability and good agreement with the gold-standard near chart measures. This study demonstrates the potential utility of the MAVERIC system for patients with ophthalmic disease to self-test their high and low contrast VA. The technique has a high degree of reliability and agreement with gold standard chart based measurements.

  3. Scotoma analysis of 10–2 visual field testing with a red target in screening for hydroxychloroquine retinopathy

    Directory of Open Access Journals (Sweden)

    Browning DJ

    2015-08-01

    Full Text Available David J Browning, Chong LeeDepartment of Ophthalmology, Charlotte Eye, Ear, Nose and Throat Associates, Charlotte, NC, USAObjective: To quantify the variability of scotomas detected by 10–2 visual field (VF testing with a red target in patients taking hydroxychloroquine without and with retinopathy.Design: Retrospective review of clinical charts and VFs.Methods: Twenty-four patients taking hydroxychloroquine without retinopathy, and eight patients taking hydroxychloroquine with retinopathy were tested in this study. Retinopathy was defined by annular scotomas on 10–2 VF testing with corroborative spectral domain optical coherence tomographic outer retinal changes and multifocal electroretinographic changes leading to cessation of hydroxychloroquine or chloroquine. Location and depth of scotoma points on 10–2 VF testing were recorded and their fates followed in serial, reliable 10–2 VFs performed with a red target over time. The main outcome measures for this study were the number of scotoma points and locations, percentage of persistent scotoma points, size of scotomas, location of scotomas, and percentage of scotomas deepening. Results: A median of 3, interquartile range (IQR (2, 5, scotoma points per VF occurred in patients without retinopathy. A median of 86%, IQR (77, 100, of these resolved on the subsequent field. For patients with retinopathy, a median of 50%, IQR (46, 79, resolved, a difference compared to patients without retinopathy that was significant (P=0.0158. The median percentage of scotoma points in the zone from 2° to 8° from fixation in eyes with retinopathy was 72%, IQR (54, 100, compared to 49%, IQR (40, 54, in eyes without retinopathy (P=0.0069. The number of persistent scotoma locations at the last visit was higher in eyes with retinopathy: 3, IQR (1, 3, versus 0, IQR (0, 1, in patients without retinopathy, P=0.0156.Conclusion: Point scotomas are common and variable in 10–2 VF testing with a red target for

  4. A visual test based on a freeware software for quantifying and displaying night-vision disturbances: study in subjects after alcohol consumption.

    Science.gov (United States)

    Castro, José J; Ortiz, Carolina; Pozo, Antonio M; Anera, Rosario G; Soler, Margarita

    2014-05-07

    In this work, we propose the Halo test, a simple visual test based on a freeware software for quantifying and displaying night-vision disturbances perceived by subjects under different experimental conditions, more precisely studying the influence of the alcohol consumption on visual function. In the Halo test, viewed on a monitor, the subject's task consists of detecting luminous peripheral stimuli around a central high-luminance stimulus over a dark background. The test, performed by subjects before and after consuming alcoholic drinks, which deteriorate visual performance, evaluates the influence that alcohol consumption exerts on the visual-discrimination capacity under low illumination conditions. Measurements were made monocularly and binocularly. Pupil size was also measured in both conditions (pre/post). Additionally, we used a double-pass device to measure objectively the optical-quality of the eye and corroborate the results from the Halo test. We found a significant deterioration of the discrimination capacity after alcohol consumption, indicating that the higher the breath-alcohol content, the greater the deterioration of the visual-discrimination capacity. After alcohol intake, the graphical results showed a greater area of undetected peripheral stimuli around the central high-luminance stimulus. An enlargement of the pupil was also observed and the optical quality of the eye was deteriorated after alcohol consumption. A greater influence of halos and other night-vision disturbances were reported with the Halo test after alcohol consumption. The Halo freeware software constitutes a positive contribution for evaluating nighttime visual performance in clinical applications, such as reported here, but also in patients after refractive surgery (where halos are present) or for monitoring (time course) some ocular pathologies under pharmacological treatment.

  5. The artificial synapse chip: From proteins to prostheses

    Science.gov (United States)

    Peterman, Mark Charles

    Most retinal prostheses use an electric field to stimulate retinal circuitry, yet information transfer in the retina is primarily through neurotransmitters. To address this difference, this thesis describes a proof of concept retinal interface based on localized chemical delivery. This system, the Artificial Synapse Chip, is based on a 5 mum aperture in a silicon nitride membrane overlying a microfluidic channel. The effectiveness of this interface is demonstrated by ejecting bradykinin on cultured excitable cells. Even with manual fluidic control, the relationship between the extent of stimulation and concentration is linear, providing enough control to limit stimulation to individual cells. A neurotransmitter-based prosthesis will require advanced fluidic control. This thesis reports the use of electroosmosis to eject or withdraw fluid from an aperture in a channel wall. This effect is demonstrated experimentally, and numerically, using a finite-element method. Our primary device is a prototype interface with four individually addressable apertures in a 2 x 2 array. Using this array, we demonstrate stimulation of both PC12 and retinal ganglion cells. This demonstration of localized chemical stimulation of excitable cells illustrates the potential of this technology for retinal prostheses. As a final application of the Artificial Synapse Chip, we applied the concept to lipid bilayer membranes and membrane-bound proteins. Not only are membrane-bound proteins crucial to the function of biological synapses, but also are important from a technological point of view. In this thesis, we use a Langmuir-Blodgett technique to producing lipid bilayers across apertures in a modified version of the Artificial Synapse Chip. These bilayers display many of the same properties as bilayers across apertures in Teflon films. In addition, these bilayers remain unbroken at transmembrane potentials over +/-400 mV, higher than Teflon-supported bilayers. We also demonstrate single

  6. A prospective evaluation of zirconia anterior partial fixed dental prostheses: Clinical results after seven years.

    Science.gov (United States)

    Solá-Ruíz, Maria Fernanda; Agustin-Panadero, Rubén; Fons-Font, Antonio; Labaig-Rueda, Carlos

    2015-06-01

    Because of the high mechanical strength of zirconium dioxide, the metal in fixed partial prostheses can now be replaced. However, the material is susceptible to aging or hydrothermal degradation and to chipping of the feldspathic veneer. The purpose of this prospective study was to evaluate the survival (without failure) and success (survival without any complication or failure) rate and clinical efficacy of anterior zirconia partial fixed dental prostheses. Twenty-seven anterior partial fixed dental prostheses of 3 to 6 units were fabricated. All participants were examined after 1 month and 6 months, then annually for 7 years. Three partial fixed dental prostheses failed and had to be removed: 2 because of secondary caries, which increased failure significantly (P=.001) and 1 because of severe chipping. Six partial fixed dental prostheses had complications: 2 debonded, 3 had chipping, and 1 had periapical pathology. All veneer porcelain fractures occurred in 6-unit fixed partial prostheses (P=.002). The clinical success rate was 88.8% after the 7-year follow-up. The clinical behavior of partial fixed dental prostheses with a zirconium dioxide core in the anterior region provides an adequate medium-term survival rate. The main cause of failure was secondary caries. The most frequent complication was chipping, which was directly related to the number of units of the prosthesis. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  7. Development of a test for recording both visual and auditory reaction times, potentially useful for future studies in patients on opioids therapy

    Directory of Open Access Journals (Sweden)

    Miceli L

    2015-02-01

    Full Text Available Luca Miceli,1 Rym Bednarova,2 Alessandro Rizzardo,1 Valentina Samogin,1 Giorgio Della Rocca1 1Department of Anesthesia and Intensive Care Medicine, University of Udine, 2Department of Pain Medicine and Palliative Care, Hospital of Latisana, Latisana, Udine, Italy Objective: Italian Road Law limits driving while undergoing treatment with certain kinds of medication. Here, we report the results of a test, run as a smartphone application (app, assessing auditory and visual reflexes in a sample of 300 drivers. The scope of the test is to provide both the police force and medication-taking drivers with a tool that can evaluate the individual’s capacity to drive safely. Methods: The test is run as an app for Apple iOS and Android mobile operating systems and facilitates four different reaction times to be assessed: simple visual and auditory reaction times and complex visual and auditory reaction times. Reference deciles were created for the test results obtained from a sample of 300 Italian subjects. Results lying within the first three deciles were considered as incompatible with safe driving capabilities. Results: Performance is both age-related (r>0.5 and sex-related (female reaction times were significantly slower than those recorded for male subjects, P<0.05. Only 21% of the subjects were able to perform all four tests correctly. Conclusion: We developed and fine-tuned a test called Safedrive that measures visual and auditory reaction times through a smartphone mobile device; the scope of the test is two-fold: to provide a clinical tool for the assessment of the driving capacity of individuals taking pain relief medication; to promote the sense of social responsibility in drivers who are on medication and provide these individuals with a means of testing their own capacity to drive safely. Keywords: visual reaction time, auditory reaction time, opioids, Safedrive

  8. A new user-friendly experiment visual database system application to the gas migration test (GMT) at the Grimsel test site

    International Nuclear Information System (INIS)

    Shimura, Tomoyuki; Asano, Hidekazu; Ando, Kenichi; Okuma, Fumiko; Yamamoto, Shuichi; Vomvoris, Stratis

    2007-01-01

    Available in abstract form only. Full text of publication follows: Long-term integrated field investigations combine information from different groups (laboratory, modeling, experimental) often working in different locations and on different time scales. The results of these different groups are evaluated and integrated for decision making during the experiment execution, but at the end of the experiment a huge database exists, which may be difficult to use at a later stage - for example, for further modeling, benchmarking etc. How can one preserve the information obtained and present it in a transparent and user-friendly manner? A new visual database system developed is presented and its application to the 'Gas Migration in-situ Test (GMT)' is described. The GMT project has been conducted to assess the gas migration (for example from TRU waste) through the engineered barrier system and the adjacent geosphere. The experiment was initiated in 1997 under the auspices of RWMC and with primary funding by the Japanese Ministry of Economy, Trade and Industry. The project consists of a large-scale in-situ test, laboratory tests and numerical modeling. The in-situ test has been performed at the Grimsel Test Site (GTS) in Switzerland operated by NAGRA (National cooperative for the disposal of radioactive waste, Switzerland). Laboratory tests have been performed in facilities in Japan, Germany, Spain and Switzerland. Finally, the modeling activities, performed within the modeling group, have included teams from the US, Spain, France, Japan, Germany and Switzerland with support from organizations BGR, ENRESA, ANDRA, and RWMC. More than 250 reports document the various data and analyses. The database developed uses a three layered framework. The first (or bottom) layer is the data storage which contains all reports, publications as well as the raw data; the second layer is a data flow diagram - from material data, generation of input data to the model and output to the end

  9. [PVD-silicoating before cementation of zirconia-based knee prostheses effects better cement adhesion and lower aseptic loosening rates].

    Science.gov (United States)

    Marx, R; Faramarzi, R; Oberbach, T; Begand, S; Grätz, N; Wirtz, D C

    2012-02-01

    CoCrMo alloys are contraindicated for allergy patients. For these patients, cemented or uncemented prostheses made of titanium alloy are indicated. Uncemented prostheses, however, have low primary retention, particularly the tibial components of knee joint prostheses because of the lack of a positive locking. Therefore, for knee replacement cemented CoCrMo prostheses may be suitable also for allergy sufferers if these are masked by ZrN or TiNbN layers. Alternatively the CoCrMo alloy may be replaced by high-strength oxide ceramics. For adhesion of bone cement to the ceramic surface, however, only inefficient mechanical retention spots are exposed as compared with a metal surface. Undercuts generated by corundum blasting, although highly efficient on a CoCrMo surface, are not such efficient centres on a ceramic surface due to its brittleness. Therefore, the mechanical component of retention is significantly reduced. When specific adhesion between bone cement and surface does not exist due to physical and chemical forces, the hydrolytic stability will be insufficient. Micromotions are promoted and early aseptic loosening is predictable. Silicoating of the ceramic surface will allow specific adhesion and can result in better hydrolytic stability of bonding. In order to evaluate the effectiveness of silicoating the bond strengths of blasted (mean size of corundum grains 50 µm) and silicate layered alumina-toughened zirconia (ATZ) surfaces were compared with "as fired" surfaces by utilising TiAlV probes (diameter 6 mm) for traction-adhesive strength testing. Samples machined out of CoCrMo alloy were utilised for reference. After preparing the samples for traction-adhesive strength testing (sequence: substrate, silicate and silane, protective lacquer [PolyMA], bone cement, TiAlV probe) they were aged up to 360 days at 37 °C in Ringer's solution. The bond strengths observed for all ageing intervals were well above 20 MPa and much higher and more hydrolytically

  10. Custom hip prostheses by integrating CAD and casting technology

    Science.gov (United States)

    Silva, Pedro F.; Leal, Nuno; Neto, Rui J.; Lino, F. Jorge; Reis, Ana

    2012-09-01

    Total Hip Arthroplasty (THA) is a surgical intervention that is being achieving high rates of success, leaving room to research on long run durability, patient comfort and costs reduction. Even so, up to the present, little research has been done to improve the method of manufacturing customized prosthesis. The common customized prostheses are made by full machining. This document presents a different approach methodology which combines the study of medical images, through CAD (Computer Aided Design) software, SLadditive manufacturing, ceramic shell manufacture, precision foundry with Titanium alloys and Computer Aided Manufacturing (CAM). The goal is to achieve the best comfort for the patient, stress distribution and the maximum lifetime of the prosthesis produced by this integrated methodology. The way to achieve this desiderate is to make custom hip prosthesis which are adapted to each patient needs and natural physiognomy. Not only the process is reliable, but also represents a cost reduction comparing to the conventional full machined custom hip prosthesis.

  11. Bionic balance organs: progress in the development of vestibular prostheses.

    Science.gov (United States)

    Smith, Paul F

    2017-09-01

    The vestibular system is a sensory system that is critically important in humans for gaze and image stability as well as postural control. Patients with complete bilateral vestibular loss are severely disabled and experience a poor quality of life. There are very few effective treatment options for patients with no vestibular function. Over the last 10 years, rapid progress has been made in developing artificial 'vestibular implants' or 'prostheses', based on cochlear implant technology. As of 2017, 13 patients worldwide have received vestibular implants and the results are encouraging. Vestibular implants are now becoming part of an increasing effort to develop artificial, bionic sensory systems, and this paper provides a review of the progress in this area.

  12. Electric stimulation with sinusoids and white noise for neural prostheses

    Directory of Open Access Journals (Sweden)

    Daniel K Freeman

    2010-02-01

    Full Text Available We are investigating the use of novel stimulus waveforms in neural prostheses to determine whether they can provide more precise control over the temporal and spatial pattern of elicited activity as compared to conventional pulsatile stimulation. To study this, we measured the response of retinal ganglion cells to both sinusoidal and white noise waveforms. The use of cell-attached and whole cell patch clamp recordings allowed the responses to be observed without significant obstruction from the stimulus artifact. Electric stimulation with sinusoids elicited robust responses. White noise analysis was used to derive the linear kernel for the ganglion cell’s spiking response as well as for the underlying excitatory currents. These results suggest that in response to electric stimulation, presynaptic retinal neurons exhibit bandpass filtering characteristics with peak response that occur 25ms after onset. The experimental approach demonstrated here may be useful for studying the temporal response properties of other neurons in the CNS.

  13. Expert opinions on success factors for upper-limb prostheses.

    Science.gov (United States)

    Schultz, Aimee E; Baade, Susan P; Kuiken, Todd A

    2007-01-01

    The goal of this study was to gather the opinions of prosthetics experts on the most important factors for the successful use of upper-limb (UL) prostheses, compare them with those of prosthesis users, and ultimately direct research efforts in this field. UL prosthetics experts were asked to compare the importance of the comfort, function, and cosmesis of a prosthetic device for a transhumeral amputee. Categories were subdivided into weight, socket-interface comfort, power, agility, color, and shape. The majority of those who responded viewed comfort as the most important factor for a unilateral amputee and considered socket-interface comfort to be more important than weight. Function was considered to be the most important factor for a bilateral amputee, with agility considered more important than power. Cosmesis was consistently reported as being less important than comfort and function, and shape was considered more important than color.

  14. Light and electronmicroscopic studies on Polycel ossicular replacement prostheses.

    Science.gov (United States)

    Cousins, V C; Jahnke, K

    1987-06-01

    Recently, a new form of porous high density polyethylene (Polycel) has been promoted for use in ossicular chain reconstruction. However, we have found no reports of investigation of the fate of this material used for this purpose in either animals or man. This study was undertaken to look at the tissue tolerance and fate of Polycel in the middle ear of gerbils before its extensive use in humans. We present the light and transmission electromicroscopic findings from these prostheses, removed from the middle ear between 1 and 5 months post-implantation. The results are similar to those found with Plastipore, showing a strong foreign body reaction and the likelihood of phagocytic consumption. As with the other porous plastics, we have reservations about the use of Polycel for ossicular reconstruction.

  15. Modular neck prostheses in DDH patients: 11-year results.

    Science.gov (United States)

    Traina, Francesco; De Fine, Marcello; Tassinari, Enrico; Sudanese, Alessandra; Calderoni, Pierina Paola; Toni, Aldo

    2011-01-01

    Total hip replacement in developmental dysplasia of the hip is a demanding procedure and usually requires dedicated devices and special surgical techniques. Nevertheless, the described techniques have shown variable outcomes. The aim of this study was to assess the 11-year outcomes of an off-the-shelf modular neck prosthesis in dysplastic patients and to evaluate the ability of the modular neck system to adequately restore femoral offset, abductor muscles lever arm and leg length. We retrospectively evaluated 61 modular neck prostheses implanted in 47 patients between June 1995 and March 2004. The preoperative diagnosis was developmental dysplasia of the hip in all cases. The clinical outcomes were assessed using the Harris hip score and the Western Ontario and McMaster Universities score. The femoral offset, abductor muscles lever arm, height and medialization of the hip center of rotation, and differences in leg length were evaluated on postoperative radiographs. Prosthesis survival was calculated according to the Kaplan-Meier method considering any reason for revision as failure. The average follow-up was 117.2 months (range 57-162 months). The cumulative survival at 11 years was 97.5%. One prosthesis failed 5 years after surgery because of a ceramic liner fracture due to an inappropriate obstetric maneuver during labour. At the latest follow-up the mean Harris hip score was 74.7 (range 23-91). Leg length discrepancy was avoided in the majority of cases; femoral offset was almost always restored. The results of this series support the use of modular neck prostheses as an effective alternative in the treatment of developmental dysplasia of the hip. The modularity was very efficient in restoring offset, leg length and maintaining stability with a good mid-long-term follow-up. Unlike other proposed surgical techniques, these good results are achievable by a standard surgical technique and with an off-the-shelf prosthesis.

  16. Auditory Neural Prostheses – A Window to the Future

    Directory of Open Access Journals (Sweden)

    Mohan Kameshwaran

    2015-06-01

    Full Text Available Hearing loss is one of the commonest congenital anomalies to affect children world-over. The incidence of congenital hearing loss is more pronounced in developing countries like the Indian sub-continent, especially with the problems of consanguinity. Hearing loss is a double tragedy, as it leads to not only deafness but also language deprivation. However, hearing loss is the only truly remediable handicap, due to remarkable advances in biomedical engineering and surgical techniques. Auditory neural prostheses help to augment or restore hearing by integration of an external circuitry with the peripheral hearing apparatus and the central circuitry of the brain. A cochlear implant (CI is a surgically implantable device that helps restore hearing in patients with severe-profound hearing loss, unresponsive to amplification by conventional hearing aids. CIs are electronic devices designed to detect mechanical sound energy and convert it into electrical signals that can be delivered to the coch­lear nerve, bypassing the damaged hair cells of the coch­lea. The only true prerequisite is an intact auditory nerve. The emphasis is on implantation as early as possible to maximize speech understanding and perception. Bilateral CI has significant benefits which include improved speech perception in noisy environments and improved sound localization. Presently, the indications for CI have widened and these expanded indications for implantation are related to age, additional handicaps, residual hearing, and special etiologies of deafness. Combined electric and acoustic stimulation (EAS / hybrid device is designed for individuals with binaural low-frequency hearing and severe-to-profound high-frequency hearing loss. Auditory brainstem implantation (ABI is a safe and effective means of hearing rehabilitation in patients with retrocochlear disorders, such as neurofibromatosis type 2 (NF2 or congenital cochlear nerve aplasia, wherein the cochlear nerve is damaged

  17. Differences in Performance of ADHD Children on a Visual and Auditory Continuous Performance Test according to IQ.

    Science.gov (United States)

    Park, Min-Hyeon; Kweon, Yong Sil; Lee, Soo Jung; Park, E-Jin; Lee, Chul; Lee, Chang-Uk

    2011-09-01

    Continuous performance tests (CPTs) are frequently used in clinical practice to assess the attentiveness of ADHD children. Although most CPTs do not categorize T scores by intelligence, there is great diversity of opinion regarding the interrelation between intelligence and CPT performance. This study aimed to determine if ADHD children with superior IQs would perform better than ADHD children with average IQs. Additionally, we aimed to examine the need for CPTs' to categorize according to IQ. Participants were 326 outpatients, aged 5-15 years, diagnosed with ADHD. All participants completed the Wechsler Intelligence Scale for Children-Revised and a CPT. After excluding those who meet exclusion criteria, we had 266 patients for our analysis. The "Highly Intelligent Group" (HIG), patients with IQs 120 and above, performed superiorly to the "Normally Intelligent Group" (NIG) patients, with IQs between 70 and 120, with regard to omission and commission errors on the visual-auditory CPT, even after controlling for age and gender. The HIG had higher ratios of subjects with T scores IQs; thus, there is a need to standardize the variables based on IQ, as well as on age and gender. Moreover, clinicians need to pay attention to the effect of IQ in interpreting CPT scores; that is, a "normal" score does not rule out a diagnosis of ADHD.

  18. Visual Processing Speed

    OpenAIRE

    Owsley, Cynthia

    2012-01-01

    Older adults commonly report difficulties in visual tasks of everyday living that involve visual clutter, secondary task demands, and time sensitive responses. These difficulties often cannot be attributed to visual sensory impairment. Techniques for measuring visual processing speed under divided attention conditions and among visual distractors have been developed and have established construct validity in that those older adults performing poorly in these tests are more likely to exhibit d...

  19. Activities of daily living with reverse prostheses: importance of scapular compensation for functional mobility of the shoulder.

    Science.gov (United States)

    Terrier, Alexandre; Scheuber, Patricia; Pioletti, Dominique P; Farron, Alain

    2013-07-01

    The nonanatomical design of reverse shoulder prostheses induce medial displacement of the center of rotation, impingements and may reduce the mobility of the shoulder. The aim of this study is to test the hypothesis that during activities of daily living functional mobility of the shoulder can be restored by scapular compensation. A numerical 3-dimensional model was developed to reproduce the movement of the scapula and humerus, during 4 activities of daily living measured experimentally. This hypothesis was tested in 4 configurations of the aequalis reverse prosthesis (standard 36-mm glenosphere, 42-mm glenosphere, lateralized 36-mm glenosphere, lateralized Bony Increased-Offset Reverse Shoulder Arthroplasty [BIO-RSA]), which were implanted in the virtual model. All impingement positions were evaluated, as the required scapular compensation to avoid impingements. With the 36-mm glenosphere, impingements occurred only for rest of hand to back-pocket positions. The 42-mm partly improved the mobility. The 2 lateralized glenospheres were free of impingement. When impingements occurred, the scapular compensation was less than 10°. Most reverse prostheses impingements reported in clinical and biomechanical studies can be avoided, either by scapular compensation or by a glenosphere lateralization. After reverse shoulder arthroplasty, a fraction of the mobility of the gleno-humeral is transferred to the scapulo-thoracic joint. Copyright © 2013 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  20. Effect of framework design on fracture load after thermal cycling and mechanical loading of implant-supported zirconia-based prostheses.

    Science.gov (United States)

    Komine, Futoshi; Kamio, Shingo; Takata, Hiroki; Yagawa, Shogo; Taguchi, Serina; Taguchi, Kohei; Hashiguchi, Akiko; Matsumura, Hideo

    2018-01-30

    This study evaluated the effect of zirconia framework design on fracture load of implant-supported zirconia-based prostheses after thermal cycling and mechanical loading. Three different zirconia framework designs were investigated: uniform-thickness (UNI), anatomic (ANA), and supported anatomic (SUP) designs. Each framework was layered with feldspathic porcelain (ZAC group) or indirect composite material (ZIC group). The specimens then underwent fracture load testing after thermal cycling and cyclic loading. In the ZAC group, mean fracture load was significantly lower for UNI design specimens than for the other framework designs. In the ZIC group, there was no significant difference in mean fracture load between ANA design specimens and either UNI or SUP design specimens. To improve fracture resistance of implant-supported zirconia-based prostheses after artificial aging, uniformly thick layering material and appropriate lingual support with zirconia frameworks should be provided.

  1. Beery-Buktenica Developmental Test of Visual-Motor Integration Performance in Children with Traumatic Brain Injury and Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Sutton, Griffin P.; Barchard, Kimberly A.; Bello, Danielle T.; Thaler, Nicholas S.; Ringdahl, Erik; Mayfield, Joan; Allen, Daniel N.

    2011-01-01

    Evaluation of visuoconstructional abilities is a common part of clinical neuropsychological assessment, and the Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI; K. E. Beery & N. A. Beery, 2004) is often used for this purpose. However, few studies have examined its psychometric properties when used to assess children and…

  2. Test of Gross Motor Development-3 (TGMD-3) with the Use of Visual Supports for Children with Autism Spectrum Disorder: Validity and Reliability

    Science.gov (United States)

    Allen, K. A.; Bredero, B.; Van Damme, T.; Ulrich, D. A.; Simons, J.

    2017-01-01

    The validity and reliability of the Test of Gross Motor Development-3 (TGMD-3) were measured, taking into consideration the preference for visual learning of children with autism spectrum disorder (ASD). The TGMD-3 was administered to 14 children with ASD (4-10 years) and 21 age-matched typically developing children under two conditions: TGMD-3…

  3. Crowding in central vision in normally sighted and visually impaired [corrected] children aged 4 to 8 years: the influence of age and test design.

    NARCIS (Netherlands)

    Huurneman, B.; Boonstra, F.N.; Cillessen, A.H.; Rens, G. van; Cox, R.F.

    2012-01-01

    BACKGROUND/AIMS: To investigate crowding ratios in children with a visual impairment due to ocular disease (n = 58) and normally sighted children (n = 75) aged 4 to 8 years using several variants of two clinically available tests with different optotype spacing (fixed or proportional to the optotype

  4. Crowding in Central Vision in Normally Sighted and Visually Impared Children Aged 4 to 8 Years: The Influence of Age and Test Design

    NARCIS (Netherlands)

    Huurneman, B.; Boonstra, F.N.; Cillessen, A.H.N.; Cox, R.F.A.; Rens, G.H.M.B. van

    2012-01-01

    Background/aims: To investigate crowding ratios in children with a visual impairment due to ocular disease (n = 58) and normally sighted children (n = 75) aged 4 to 8 years using several variants of two clinically available tests with different optotype spacing (fixed or proportional to the optotype

  5. Crowding in Central Vision in Normally Sighted and Visually Impared Children Aged 4 to 8 Years: The Influence of Age and Test Design

    NARCIS (Netherlands)

    Huurneman, B.; Boonstra, F.N.; Cillessen, A.H.; van Rens, G.H.M.B.; Cox, R.F.A.

    2012-01-01

    Background/aims: To investigate crowding ratios in children with a visual impairment due to ocular disease (n=58) and normally sighted children (n=75) aged 4 to 8 years using several variants of two clinically available tests with different optotype spacing (fixed or proportional to the optotype

  6. A Comparative Analysis of the Bender-Gestalt and Beery/Buktenica Tests of Visual-Motor Integration as a Function of Grade Level for Regular Education Students.

    Science.gov (United States)

    Lehman, Joanne; Breen, Michael J.

    1982-01-01

    Regular education students (N=125) in grades K-3 were administered the Bender-Gestalt and Beery/Buktenica tests of visual-motor integration. Found significant differences between the mean Bender and Beery age equivalent scores at each grade level. Discusses implications for their utilization in assessing fine motor readiness development.…

  7. Three-unit posterior zirconia-ceramic fixed dental prostheses (FDPs) veneered with layered and milled (CAD-on) veneering ceramics: 1-year follow-up of a randomized controlled clinical trial

    OpenAIRE

    Grohmann, Philipp; Bindl, Andreas; Hämmerle, Christoph; Mehl, Albert; Sailer, Irena

    2015-01-01

    The aim of this multicenter randomized controlled clinical trial was to test posterior zirconia-ceramic fixed dental prostheses (FDPs) veneered with a computer-aided design/computer- assisted manufacture (CAD/CAM) lithium disilicate veneering ceramic (CAD-on) and manually layered zirconia veneering ceramic with respect to survival of the FDPs, and technical and biologic outcomes.

  8. Visual attention capacity

    DEFF Research Database (Denmark)

    Habekost, Thomas; Starrfelt, Randi

    2009-01-01

    Psychophysical studies have identified two distinct limitations of visual attention capacity: processing speed and apprehension span. Using a simple test, these cognitive factors can be analyzed by Bundesen's Theory of Visual Attention (TVA). The method has strong specificity and sensitivity...

  9. Evaluation of the marginal and internal gaps of three different dental prostheses: comparison of the silicone replica technique and three-dimensional superimposition analysis.

    Science.gov (United States)

    Park, Jin-Young; Bae, So-Yeon; Lee, Jae-Jun; Kim, Ji-Hwan; Kim, Hae-Young; Kim, Woong-Chul

    2017-06-01

    The purposes of this study were to evaluate the marginal and internal gaps, and the potential clinical applications of three different methods of dental prostheses fabrication, and to compare the prostheses prepared using the silicone replica technique (SRT) and those prepared using the three-dimensional superimposition analysis (3DSA). Five Pekkton, lithium disilicate, and zirconia crowns were each manufactured and tested using both the SRT and the two-dimensional section of the 3DSA. The data were analyzed with the nonparametric version of a two-way analysis of variance using rank-transformed values and the Tukey's post-hoc test (α = .05). Significant differences were observed between the fabrication methods in the marginal gap ( P .350), deep chamfer ( P > .719), and axial wall ( P > .150). As the 3DSA method is three-dimensional, it allows for the measurement of arbitrary points. All of the three fabrication methods are valid for measuring clinical objectives because they produced prostheses within the clinically acceptable range. Furthermore, a three-dimensional superimposition analysis verification method such as the silicone replica technique is also applicable in clinical settings.

  10. Soft tissue facial morphometry before and after total oral rehabilitation with implant-supported prostheses.

    Science.gov (United States)

    Tartaglia, Gianluca M; Dolci, Claudia; Sidequersky, Fernanda V; Ferrario, Virgilio F; Sforza, Chiarella

    2012-11-01

    The objective of the current study was to assess a low-cost, noninvasive facial morphometric digitizer to assist the practitioner in three-dimensional soft-tissue changes before and after oral rehabilitation. Twenty-two patients aged 45 to 82 years, all with edentulous maxilla and mandible, were assessed both before and after receiving their definitive complete implant-supported prostheses (each received 4-11 implants in each dental arch; full-arch fixed prostheses were made). The three-dimensional coordinates of 50 soft-tissue facial landmarks were collected with a noninvasive digitizer; labial and facial areas, volumes, angles, and distances were compared without and with the prostheses. Dental prostheses induced significant reductions in the nasolabial, mentolabial, and interlabial angles, with increased labial prominence (P provisional prosthetic restoration, providing quantitative information to prepare the best definitive prosthesis.

  11. An Up-to-15-Year Comparison of the Survival and Complication Burden of Three-Unit Tooth-Supported Fixed Dental Prostheses and Implant-Supported Single Crowns.

    Science.gov (United States)

    Walton, Terry R

    2015-01-01

    To assess and compare the outcomes and economic complication burden of three-unit tooth-supported fixed dental prostheses (TFDPs) and implant-supported single crowns (ISCs) provided to a sequential cohort in a specialist prosthodontic practice over a 15-year period. Sequential patients requiring replacement of a single missing tooth between 1996 and 2010 with a metal-ceramic three-unit TFDP (n = 145 patients, n = 174 prostheses) or ISC (n = 174 patients, n = 220 prostheses) were included. Prostheses subjectively judged at insertion to have an unfavorable 10-year prognosis (17 TFDPs, 0 ISCs) were removed from statistical analyses. The estimated cumulative survival (ECS) was calculated with the life table actuarial method and standard errors calculated with the Greenwood formula. Differences in outcomes between all prostheses and those replacing only anterior or only posterior teeth were assessed with the log rank test. Complication incidence, severity, and economic burden, measured in time/cost accounting units (TAUs), were tallied and compared descriptively. The 15-year ECS did not differ for 112 TFDPs (92.75% ± 3.28%) and 81 ISCs (95.95% ± 2.92%) replacing posterior teeth. However, the 15-year ECS was significantly greater for 139 ISCs (93.33% ± 6.44%) than for 45 TFDPs (82.82% ± 6.50%) replacing anterior teeth. The economic burden of nonterminal complications for both prostheses was low (mean = 0.3 and 0.2 TAUs per prosthesis for TFDPs and ISCs, respectively). This equated to 3 TAUs/100 years in clinical service and 4 TAUs/100 years in clinical service for the TFDPs and ISCs, respectively. The survival of three-unit TFDPs and ISCs over 15 years was not statistically different when replacing posterior teeth, but ISCs survived significantly better when replacing anterior teeth. The complication rates of the TFDPs and ISCs were similar, but the economic burden for the TFDPs was greater.

  12. Development and validation of an achievement test in introductory quantum mechanics: The Quantum Mechanics Visualization Instrument (QMVI)

    Science.gov (United States)

    Cataloglu, Erdat

    The purpose of this study was to construct a valid and reliable multiple-choice achievement test to assess students' understanding of core concepts of introductory quantum mechanics. Development of the Quantum Mechanics Visualization Instrument (QMVI) occurred across four successive semesters in 1999--2001. During this time 213 undergraduate and graduate students attending the Pennsylvania State University (PSU) at University Park and Arizona State University (ASU) participated in this development and validation study. Participating students were enrolled in four distinct groups of courses: Modern Physics, Undergraduate Quantum Mechanics, Graduate Quantum Mechanics, and Chemistry Quantum Mechanics. Expert panels of professors of physics experienced in teaching quantum mechanics courses and graduate students in physics and science education established the core content and assisted in the validating of successive versions of the 24-question QMVI. Instrument development was guided by procedures outlined in the Standards for Educational and Psychological Testing (AERA-APA-NCME, 1999). Data gathered in this study provided information used in the development of successive versions of the QMVI. Data gathered in the final phase of administration of the QMVI also provided evidence that the intended score interpretation of the QMVI achievement test is valid and reliable. A moderate positive correlation coefficient of 0.49 was observed between the students' QMVI scores and their confidence levels. Analyses of variance indicated that students' scores in Graduate Quantum Mechanics and Undergraduate Quantum Mechanics courses were significantly higher than the mean scores of students in Modern Physics and Chemistry Quantum Mechanics courses (p < 0.05). That finding is consistent with the additional understanding and experience that should be anticipated in graduate students and junior-senior level students over sophomore physics majors and majors in another field. The moderate

  13. Progress in the clinical development and utilization of vision prostheses: an update.

    Science.gov (United States)

    Brandli, Alice; Luu, Chi D; Guymer, Robyn H; Ayton, Lauren N

    2016-01-01

    Vision prostheses, or "bionic eyes", are implantable medical bionic devices with the potential to restore rudimentary sight to people with profound vision loss or blindness. In the past two decades, this field has rapidly progressed, and there are now two commercially available retinal prostheses in the US and Europe, and a number of next-generation devices in development. This review provides an update on the development of these devices and a discussion on the future directions for the field.

  14. [Morphological features of utilization intraperitoneal double-sided prostheses in inguinoplasty in dogs].

    Science.gov (United States)

    de Andrade, Luiz Carlos; Ceneviva, Reginaldo; Coutinho-Netto, Joaquim; Silva Júnior, Orlando de Castro e; dos Santos, José Sebastião; Sukeda, Daniel Hirochi

    2009-10-01

    To asses the morphological features of the behavior of a double-sided prostheses using inguinoplasty laparotomy in dogs with latex side turned to the visceras. Twenty dogs were divided into two groups of 10 and submitted into infraumbilical laparotomy with double-sided prostheses fixed in an inguinal area and in the other side area a control prostheses of polipropilene (PPL). Macroscopics itens were studied on the 14th and 28th day post-operatory, and they were related to obstruction and intestinal fistulas, encystation, fusion and especially sticker. The microscopic analysis covered the inflammatory process in its acute, chronic and restored phase Infectious process, obstruction or intestinal fistula did not happen. The prostheses presented good accommodation and incorporation. The stickers happened with more prevalent and intensity with the PPL (p0,05). The double-sided prostheses in its parietal side adds the advantages of the incorporation's potential to the noticed material with PPL to the biocompatibility from the latex in its visceral side. The little distance between the PPL disc and the edge of the double-sided prostheses (2 cm) allied to its sticking with just five staples is not enough to avoid gaps, through which the epíploon migrated towards to the inflammatory process provoked by PPL in the parietal side.

  15. Visual-Constructional Ability in Individuals with Severe Obesity: Rey Complex Figure Test Accuracy and the Q-Score

    Directory of Open Access Journals (Sweden)

    Hanna L. Sargénius

    2017-09-01

    Full Text Available The aims of this study were to investigate visual-construction and organizational strategy among individuals with severe obesity, as measured by the Rey Complex Figure Test (RCFT, and to examine the validity of the Q-score as a measure for the quality of performance on the RCFT. Ninety-six non-demented morbidly obese (MO patients and 100 healthy controls (HC completed the RCFT. Their performance was calculated by applying the standard scoring criteria. The quality of the copying process was evaluated per the directions of the Q-score scoring system. Results revealed that the MO did not perform significantly lower than the HC on Copy accuracy (mean difference −0.302, CI −1.374 to 0.769, p = 0.579. In contrast, the groups did statistically differ from each other, with MO performing poorer than the HC on the Q-score (mean −1.784, CI −3.237 to −0.331, p = 0.016 and the Unit points (mean −1.409, CI −2.291 to −0.528, p = 0.002, but not on the Order points score (mean −0.351, CI −0.994 to 0.293, p = 0.284. Differences on the Unit score and the Q-score were slightly reduced when adjusting for gender, age, and education. This study presents evidence supporting the presence of inefficiency in visuospatial constructional ability among MO patients. We believe we have found an indication that the Q-score captures a wider range of cognitive processes that are not described by traditional scoring methods. Rather than considering accuracy and placement of the different elements only, the Q-score focuses more on how the subject has approached the task.

  16. Evidence suggesting superiority of visual (verbal) vs. auditory test presentation modality in the P300-based, Complex Trial Protocol for concealed autobiographical memory detection.

    Science.gov (United States)

    Rosenfeld, J Peter; Ward, Anne; Frigo, Vincent; Drapekin, Jesse; Labkovsky, Elena

    2015-04-01

    One group of participants received a series of city name stimuli presented on trials of the Complex Trial Protocol (CTP) version of a P300-based, concealed information test (CIT). Stimuli were presented on alternating trials in either auditory or visual presentation modality. In 1/7 of the trials the participant's home town (probe) repeatedly appeared in a series of 6 other (irrelevant) repeated city names. In both modalities, probe stimuli produced larger P300s than irrelevant stimuli. Visual stimuli produced shorter behavioral reaction times and P300 latencies, as well as larger P300 probe amplitudes, probe-irrelevant amplitude differences, and individual diagnostic accuracies than the same stimuli presented in the auditory modality. Possible reasons for these effects are discussed, and subject to discussed limitations, the applied conclusion reached is that in all CITs, visual presentation of stimuli, if feasible, should be preferentially used. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Superiority of visual (verbal) vs. auditory test presentation modality in a P300-based CIT: The Complex Trial Protocol for concealed autobiographical memory detection.

    Science.gov (United States)

    Deng, Xiaohong; Rosenfeld, J Peter; Ward, Anne; Labkovsky, Elena

    2016-07-01

    This paper continues our efforts to determine which modality is best for presentation of stimuli in the P300-based concealed information test (CIT) called the Complex Trial Protocol (CTP). The first part of the CTP trial involves presentation of the key probe or irrelevant stimuli, and is followed by presentation of target (T) or non-target (NT). In Rosenfeld et al. (2015), probes and irrelevants regularly alternated modality over trials, but Ts and NTs were always visual. In the present study, (in both its experiments, EXP 1 and EXP 2), probes and irrelevants alternated modalities on successive trials, as before. In present EXP 1, Ts and NTs were always auditory, but in EXP 2, they were simultaneously auditory and visual. Probe P300 data were different in each study: In Rosenfeld et al. (2015) and EXP 2 here, the bootstrap-based detection rates based on probe-minus-irrelevant differences, significantly differed favoring visual probe and irrelevant presentation modality. In EXP 1 here, detection rates were the same for the two modalities. In Rosenfeld et al. (2015) there was no main effect of probe modality, visual vs. auditory on probe-minus-irrelevant P300 difference. There were such effects here in EXP 1 (pvisual modality. Probe P300 latencies were shorter for visual than for auditory stimuli in Rosenfeld et al. (2015), a trend specifically reversed in the present pair of studies. RT was faster for visual stimuli in the present studies. The T and NT modality appears to interact with probe/irrelevant modality, and the best protocol for detecting concealed information is with the 2015 study protocol or that of EXP 2, using visual stimulus presentation. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Effect of veneering technique on the fracture resistance of zirconia fixed dental prostheses.

    Science.gov (United States)

    Chaar, M S; Witkowski, S; Strub, J R; Att, W

    2013-01-01

    To compare the fracture resistance of zirconia 3-unit posterior fixed dental prostheses (FDPs) frameworks veneered with different veneering materials and techniques before and after artificial ageing. Forty-eight zirconia 3-unit FDPs, representing a missing first molar, were adhesively cemented on human teeth. The zirconia frameworks were randomly distributed according to the veneering materials and techniques into three groups, each containing 16 samples: group LV (layering technique/Vintage ZR), group LZ (layering technique/ZIROX) and group PP (CAD/CAM and press-over techniques/PressXZr). Half of each group was artificially aged through dynamic loading and thermocycling to simulate 5 years of clinical service. Afterwards, all specimens were tested for fracture resistance using compressive load. An analysis of variance (anova) was used to assess the effect of veneering ceramic and artificial ageing on fracture resistance (P veneered with the layering technique (P veneered with the CAD/CAM and press-over techniques. All tested systems have the potential to withstand occlusal forces applied in the posterior region. The combination of the CAD/CAM and press-over techniques for the veneering process improved the overall stability after artificial ageing, relative to the layering technique. © 2012 Blackwell Publishing Ltd.

  19. [The effect of polyester vascular prostheses on synthesis TNF-alpha, IFN-gamma and NO by human peripheral blood leukocytes--in vitro].

    Science.gov (United States)

    Zywicka, Bogusława; Czarny, Anna; Zaczyńska, Ewa; Pielka, Stanisław; Solski, Leszek

    2005-01-01

    Vascular prostheses produced on the basis of polyester are today commonly used in vascular surgery. To improve their biofuncionality special technologies are used, among them double knit and hydrophile feature enrichment. These modifications could cause the local activation of leukocytes to produce the mediators of inflammatory reaction, which in turn leads to hyperplasia of endothelium and other dangerous complications. In our study we used two kinds of polyester prostheses: double velour knitted hydrophilic Dallon H and standard double velour knitted prosthesis Dallon as control. The aim of this work was to compare in vitro the levels of cytokines TNF-alpha, interferon (IFN) and nitric oxide (NO) found in the supernatants of human blood leukocyte cultures after stimulation by both these above-mentioned vascular prostheses materials which are designed for use in direct blood contact. Tested implant materials Dallon H had no influence on synthesis of production of IFN, TNF-alpha and NO by human blood leukocytes. These results allow to made the initial selection of biomaterials before their in vivo evaluation.

  20. Application of dexterous space robotics technology to myoelectric prostheses

    Science.gov (United States)

    Hess, Clifford; Li, Larry C. H.; Farry, Kristin A.; Walker, Ian D.

    1994-01-01

    Future space missions will require robots equipped with highly dexterous robotic hands to perform a variety of tasks. A major technical challenge in making this possible is an improvement in the way these dexterous robotic hands are remotely controlled or teleoperated. NASA is currently investigating the feasibility of using myoelectric signals to teleoperate a dexterous robotic hand. In theory, myoelectric control of robotic hands will require little or no mechanical parts and will greatly reduce the bulk and weight usually found in dexterous robotic hand control devices. An improvement in myoelectric control of multifinger hands will also benefit prosthetics users. Therefore, as an effort to transfer dexterous space robotics technology to prosthetics applications and to benefit from existing myoelectric technology, NASA is collaborating with the Limbs of Love Foundation, the Institute for Rehabilitation and Research, and Rice University in developing improved myoelectric control multifinger hands and prostheses. In this paper, we will address the objectives and approaches of this collaborative effort and discuss the technical issues associated with myoelectric control of multifinger hands. We will also report our current progress and discuss plans for future work.

  1. Implant-supported prostheses versus conventional permanent and removable dentures

    Directory of Open Access Journals (Sweden)

    Koszuta Agnieszka

    2014-06-01

    Full Text Available Social, economic and technological progress results in an increasing range of treatment and rehabilitation methods for patients with partial or complete edentulism. The role of the dentist is to inform the patient about the full range of available missing teeth treatment options leading to complete rehabilitation of the masticatory organ in agreement with the patient’s aesthetic and functional expectations. The aim of the paper was to identify the type of prostheses used by patients before opting for implantsupported teeth replacements, according to the patients’ age, sex, marital status, place of residence and education. The study covered 464 patients, women and men, aged 20-74, treated with dental implants. The patients answered questions in an anonymous questionnaire. The influence of the prosthetic replacement type according to age and marital status was highly statistically significant, whereas it was statistically significant according to sex, place of residence and education. The female respondents who previously used tissue-borne complete or partial dentures opted for implant treatment more frequently. The respondents younger than 40 and between 40-60 years of age who did not previously used any prosthetic replacements opted for implant treatment more frequently. The respondents who did not use any prosthetic replacements decided to undergo implant treatment most frequently, regardless of their marital status, education and place of residence. The patients opted for implant treatment to improve their quality of life, despite the high cost of such therapy.

  2. Complete integration of technology for improved reproduction of auricular prostheses.

    Science.gov (United States)

    Watson, Jason; Hatamleh, Muhanad M

    2014-05-01

    The accurate reproduction of the form and surface details of missing body structures is an essential part of any successful prosthetic rehabilitation. It helps mask the prosthesis and gives confidence to the patient. This clinical report details the integration of multiple in-house digital technologies of laser scanning, rapid prototyping, and digital color scanning and formulating to improve the shape, texture, orientation, and color of auricular prostheses for 3 patients with missing unilateral ears. A structured light laser scanner was used to digitize the patient's nondefect ear. The digitized data were then manipulated in specialist software and mirrored to reflect the opposing side. A rapid prototyping machine was used to manufacture a 3-dimensional (3D) model of the soft tissue required. This 3D mirrored ear model allowed the accurate reproduction of missing soft tissue. A color spectrometer was used to accurately reproduce the skin tones digitally and physically. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  3. Hydrogel-Electrospun Fiber Mat Composite Coatings for Neural Prostheses

    Directory of Open Access Journals (Sweden)

    Ning eHan

    2011-03-01

    Full Text Available Achieving stable, long-term performance of implanted neural prosthetic devices has been challenging because of implantation related neuron loss and a foreign body response that results in encapsulating glial scar formation. To improve neuron-prosthesis integration and form chronic, stable interfaces, we investigated the potential of neurotrophin-eluting hydrogel-electrospun fiber mat (EFM composite coatings. In particular, poly(ethylene glycol-poly(ε-caprolactone (PEGPCL hydrogel- poly(ε-caprolactone (PCL EFM composites were applied as coatings for multielectrode arrays (MEAs. Coatings were stable and persisted on electrode surfaces for over 1 month under an agarose gel tissue phantom and over 9 months in a PBS immersion bath. To demonstrate drug release, a neurotrophin, nerve growth factor (NGF, was loaded in the PEGPCL hydrogel layer, and coating cytotoxicity and sustained NGF release were evaluated using a PC12 cell culture model. Quantitative MTT assays showed that these coatings had no significant toxicity toward PC12 cells, and neurite extension at day 7 and 14 confirmed sustained release of NGF at biologically significant concentrations for at least 2 weeks. Our results demonstrate that hydrogel-EFM composite materials can be applied to neural prostheses as a means to improve neuron-electrode proximity and enhance long-term device performance and function.

  4. Repairing method of fixed partial prostheses in dentistry: laser welding

    Science.gov (United States)

    Negrutiu, Meda L.; Sinescu, Cosmin; Cozarov, Dalibor; Culea, Laurentiu; Rominu, Mihai; Pop, Daniela M.

    2008-02-01

    Laser Welding is an advantageous method of connecting or repairing metal prosthetic frameworks because there are fewer effects of heating on the area surrounding the spot to be welded, and no further procedures, such as those used for conventional soldering, are necessary. Laser welding has been increasingly applied for fabricating the metal frameworks of prostheses and for other procedures, such as recovering the metal ridge and cusp, blocking holes on the occlusal surfaces after excess occlusal adjustment, thickening the metal framework, or adding contact points after excess grinding and adjusting of the crown margins. The objective of this study are represented by investigation and evaluation of three types of soldering compare to laser welding. The method is represented by the laser welding with a pulsed Nd-Yag Laser equipment. Other joints were produced, using three different soldering techniques. These joining areas were investigated for their quality and their corrosion properties. Corrosion attack was confirmed by electron microscopy. The investigations confirm the quality of laser welding. The investigated different laser welding methods revealed minimal corrosion and offers clear-cut advantages compared to the other soldering methods. Dental alloys are subjected to functional influences in the oral cavity and interact with the intraoral enviroment.

  5. Maternal play behaviors, child negativity, and preterm or low birthweight toddlers' visual-spatial outcomes: testing a differential susceptibility hypothesis.

    Science.gov (United States)

    Dilworth-Bart, Janean E; Miller, Kyle E; Hane, Amanda

    2012-04-01

    We examined the joint roles of child negative emotionality and parenting in the visual-spatial development of toddlers born preterm or with low birthweights (PTLBW). Neonatal risk data were collected at hospital discharge, observer- and parent-rated child negative emotionality was assessed at 9-months postterm, and mother-initiated task changes and flexibility during play were observed during a dyadic play interaction at 16-months postterm. Abbreviated IQ scores, and verbal/nonverbal and visual-spatial processing data were collected at 24-months postterm. Hierarchical regression analyses did not support our hypothesis that the visual-spatial processing of PTLBW toddlers with higher negative emotionality would be differentially susceptible to parenting behaviors during play. Instead, observer-rated distress and a negativity composite score were associated with less optimal visual-spatial processing when mothers were more flexible during the 16-month play interaction. Mother-initiated task changes did not interact with any of the negative emotionality variables to predict any of the 24-month neurocognitive outcomes, nor did maternal flexibility interact with mother-rated difficult temperament to predict the visual-spatial processing outcomes. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Maternal play behaviors, child negativity, and preterm or low birthweight toddlers’ visual-spatial outcomes: Testing a differential susceptibility hypothesis

    Science.gov (United States)

    Dilworth-Bart, Janean E.; Miller, Kyle E.; Hane, Amanda

    2012-01-01

    Objective We examined the joint roles of child negative emotionality and parenting in the visual-spatial development of toddlers born preterm or with low birthweights (PTLBW). Method Neonatal risk data were collected at hospital discharge, observer- and parent-rated child negative emotionality was assessed at 9-months postterm, and mother-initiated task changes and flexibility during play were observed during a dyadic play interaction at 16-months postterm. Abbreviated IQ scores, and verbal/nonverbal and visual-spatial processing data were collected at 24-months postterm. Results Hierarchical regression analyses did not support our hypothesis that the visual-spatial processing of PTLBW toddlers with higher negative emotionality would be differentially susceptible to parenting behaviors during play. Instead, observer-rated distress and a negativity composite score were associated with less optimal visual-spatial processing when mothers were more flexible during the 16-month play interaction. Mother-initiated task changes did not interact with any of the negative emotionality variables to predict any of the 24-month neurocognitive outcomes, nor did maternal flexibility interact with mother-rated difficult temperament to predict the visual-spatial processing outcomes. PMID:22209050

  7. Effects of Zaprinast and Rolipram on Olfactory and Visual Memory in the Social Transmission of Food Preference and Novel Object Recognition Tests in Mice

    Directory of Open Access Journals (Sweden)

    Furuzan Akar

    2014-01-01

    Full Text Available The role of phosphodiesterase (PDE inhibitors in central nervous system has been investigated and shown to stimulate neuronal functions and increase neurogenesis in Alzheimer patients. The aim of this study is to investigate effect of PDE5 inhibitor zaprinast and PDE4 inhibitor rolipram on visual memory in novel object recognition (NOR test, on olfactory memory in social transmission of food preference (STFP test, and also on locomotion and anxiety in open field test in naive mice. Male Balb-c mice were treated intraperitoneally (i.p. with zaprinast (3 and 10 mg/kg, rolipram (0.05 and 0.1 mg/kg, or physiological saline. Zaprinast (10 mg/kg significantly increased cued/non-cued food eaten compared to control group, while rolipram had a partial effect on retention trial of STFP test. Zaprinast (10 mg/kg and rolipram (0.05 and 0.1 mg/kg significantly increased ratio index (RI compared to control group in retention trial of NOR test. There was no significant effect of zaprinast and rolipram on total distance moved, speed, and center zone duration in open field test. Results of this study revealed that both zaprinast and rolipram enhanced visual memory in NOR test, however zaprinast exerted a significant memory-enhancing effect compared to rolipram in STFP test in mice.

  8. Correspondence between visual and electrical input filters of ON and OFF mouse retinal ganglion cells

    Science.gov (United States)

    Sekhar, S.; Jalligampala, A.; Zrenner, E.; Rathbun, D. L.

    2017-08-01

    Objective. Over the past two decades retinal prostheses have made major strides in restoring functional vision to patients blinded by diseases such as retinitis pigmentosa. Presently, implants use single pulses to activate the retina. Though this stimulation paradigm has proved beneficial to patients, an unresolved problem is the inability to selectively stimulate the on and off visual pathways. To this end our goal was to test, using white noise, voltage-controlled, cathodic, monophasic pulse stimulation, whether different retinal ganglion cell (RGC) types in the wild type retina have different electrical input filters. This is an important precursor to addressing pathway-selective stimulation. Approach. Using full-field visual flash and electrical and visual Gaussian noise stimulation, combined with the technique of spike-triggered averaging (STA), we calculate the electrical and visual input filters for different types of RGCs (classified as on, off or on-off based on their response to the flash stimuli). Main results. Examining the STAs, we found that the spiking activity of on cells during electrical stimulation correlates with a decrease in the voltage magnitude preceding a spike, while the spiking activity of off cells correlates with an increase in the voltage preceding a spike. No electrical preference was found for on-off cells. Comparing STAs of wild type and rd10 mice revealed narrower electrical STA deflections with shorter latencies in rd10. Significance. This study is the first comparison of visual cell types and their corresponding temporal electrical input filters in the retina. The altered input filters in degenerated rd10 retinas are consistent with photoreceptor stimulation underlying visual type-specific electrical STA shapes in wild type retina. It is therefore conceivable that existing implants could target partially degenerated photoreceptors that have only lost their outer segments, but not somas, to selectively activate the on and off

  9. Quality of life after aortic valve replacement with biological prostheses in elderly patients

    Directory of Open Access Journals (Sweden)

    D. P. Demidov

    2017-11-01

    Full Text Available Aim. The paper aims to assess the quality of life of patients subjected to aortic valve replacement with a stented/stentless biological prosthesis. Methods. The research was done at the Acquired Heart Disease Department of Meshalkin National Medical Research Center. The inclusion criteria were patient age older than 65 years and severe stenosis of the aortic valve. 114 patients were randomized 1:1 in two groups: group I patients received stentless biological prostheses, while group II patients — stented xenopericardial ones. All patients underwent aortic valve replacement under normothermic cardiopulmonary bypass. Mean follow-up was 3.9 [2.77; 4.55] years, mean age 71.5±4 (65–84 years, mean left ventricle ejection fraction 65.5 (40–86 % and mean preoperative Log.Euroscore 5.4±1.3 (1.4–12.4. The quality of life was assessed by using a standard questionnaire SF-36.Results. Peak transprosthetic gradients at 1-year follow-up amounted to 16.22±4.34 and 24.66±4.74 mm Hg for group I and group II respectively. The 5-year survival rate was 90 [81; 99] % and 96 [90; 100] % for the two groups respectively and did not differ statistically (log rank test, p = 0.226. A statistically significant improvement of quality of life among patients in both groups was observed at 1-year follow-up, as compared to the preoperative values, however, marked intergroup differences in any of the parameters were not recorded.Conclusion. The quality of life after aortic valve replacement with stented and stentless biological prostheses in elderly patients confirms clinical and functional efficiency of both methods, does not show sound advantages of any of them and improves both the physical component of health and subjective emotional level.Received 25 July 2017. Revised 18 August 2017. Accepted 28 August 2017.Funding: The study was carried out with the support of a grant of the President of the Russian Federation (МД–6967.2016.7 created to provide government

  10. An in vivo comparative study of the e-polytetrafluoroethylene vascular prostheses: Vitaflon and Gore-Tex.

    Science.gov (United States)

    Dobrova, N B; Gorodkov, A J; Sidorenko, E S; Schekhter, A B; Baquey, C

    1999-12-01

    A comparative study was performed in order to validate new Russian e-PTFE vascular prostheses Vitaflon (St. Petersburg, Russia). The Gore-Tex prostheses were chosen as a referential model. The prostheses were implanted in the venous and arterial positions in 13 dog experiments. After the implantation time was over a comprehensive histological and histochemical examination of excized specimens was performed. It was demonstrated that there is no difference in healing and functional properties between the two studied prostheses. Copyright 1999 Kluwer Academic Publishers

  11. Relationship of visual motor development and academic performance of young children in Hong Kong assessed on the Bender-Gestalt test.

    Science.gov (United States)

    Chan, P W

    2000-02-01

    This study compared the Qualitative Scoring System for the Modified Version of the Bender-Gestalt test and the Developmental Scoring System for the Bender-Gestalt test in predicting performance on the Standardized Attainment Test of young children in Hong Kong. The study was done in two phases. First, 748 middle class children ages 4 to 8 years from 6 kindergartens and 6 primary schools were given the Bender-Gestalt test individually in kindergarten and in groups for older children, respectively. Both scoring systems were used to measure the children's visual motor development. Second, among the participants' protocols, 257 Primary 1 to Primary 3 children ages 6 to 8 years were selected to compare the Qualitative Scoring System for the 6 designs of the Modified Version of the Bender-Gestalt test and the Developmental Scoring System for the 9 designs of the Bender-Gestalt test in predicting performance on the Standardized Attainment Test. Results indicated that the Qualitative Scoring System differentiates better than the Developmental Scoring System in evaluating visual-motor development among young Chinese children from Hong Kong. Results also indicated that the Qualitative Scoring System correlated significantly with achievement in Chinese and English at all three levels. Scores on the Developmental Scoring System correlated significantly with only marks for Primary 1 and Primary 2 Chinese.

  12. Visual field

    Science.gov (United States)

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam. This is a quick and basic check of the visual field. The health care provider ...

  13. Visual Impairment

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Visual Impairment KidsHealth / For Teens / Visual Impairment What's in ... with the brain, making vision impossible. What Is Visual Impairment? Many people have some type of visual ...

  14. Adhesive retention of experimental fiber-reinforced composite, orthodontic acrylic resin, and aliphatic urethane acrylate to silicone elastomer for maxillofacial prostheses.

    Science.gov (United States)

    Kosor, Begüm Yerci; Artunç, Celal; Şahan, Heval

    2015-07-01

    A key factor of an implant-retained facial prosthesis is the success of the bonding between the substructure and the silicone elastomer. Little has been reported on the bonding of fiber reinforced composite (FRC) to silicone elastomers. Experimental FRC could be a solution for facial prostheses supported by light-activated aliphatic urethane acrylate, orthodontic acrylic resin, or commercially available FRCs. The purpose of this study was to evaluate the bonding of the experimental FRC, orthodontic acrylic resin, and light-activated aliphatic urethane acrylate to a commercially available high-temperature vulcanizing silicone elastomer. Shear and 180-degree peel bond strengths of 3 different substructures (experimental FRC, orthodontic acrylic resin, light-activated aliphatic urethane acrylate) (n=15) to a high-temperature vulcanizing maxillofacial silicone elastomer (M511) with a primer (G611) were assessed after 200 hours of accelerated artificial light-aging. The specimens were tested in a universal testing machine at a cross-head speed of 10 mm/min. Data were collected and statistically analyzed by 1-way ANOVA, followed by the Bonferroni correction and the Dunnett post hoc test (α=.05). Modes of failure were visually determined and categorized as adhesive, cohesive, or mixed and were statistically analyzed with the chi-squared goodness-of-fit test (α=.05). As the mean shear bond strength values were evaluated statistically, no difference was found among the experimental FRC, aliphatic urethane acrylate, and orthodontic acrylic resin subgroups (P>.05). The mean peel bond strengths of experimental fiber reinforced composite and aliphatic urethane acrylate were not found to be statistically different (P>.05). The mean value of the orthodontic acrylic resin subgroup peel bond strength was found to be statistically lower (P.05). Shear forces predominantly exhibited cohesive failure (64.4%), whereas peel forces predominantly exhibited adhesive failure (93.3%). The

  15. Mechanical compatibility of sol-gel annealing with titanium for orthopaedic prostheses.

    Science.gov (United States)

    Greer, Andrew I M; Lim, Teoh S; Brydone, Alistair S; Gadegaard, Nikolaj

    2016-01-01

    Sol-gel processing is an attractive method for large-scale surface coating due to its facile and inexpensive preparation, even with the inclusion of precision nanotopographies. These are desirable traits for metal orthopaedic prostheses where ceramic coatings are known to be osteoinductive and the effects may be amplified through nanotexturing. However there are a few concerns associated with the application of sol-gel technology to orthopaedics. Primarily, the annealing stage required to transform the sol-gel into a ceramic may compromise the physical integrity of the underlying metal. Secondly, loose particles on medical implants can be carcinogenic and cause inflammation so the coating needs to be strongly bonded to the implant. These concerns are addressed in this paper. Titanium, the dominant material for orthopaedics at present, is examined before and after sol-gel processing for changes in hardness and flexural modulus. Wear resistance, bending and pull tests are also performed to evaluate the ceramic coating. The findings suggest that sol-gel coatings will be compatible with titanium implants for an optimum temperature of 500 °C.

  16. Waterjet cutting of periprosthetic interface tissue in loosened hip prostheses: an in vitro feasibility study.

    Science.gov (United States)

    Kraaij, Gert; Tuijthof, Gabrielle J M; Dankelman, Jenny; Nelissen, Rob G H H; Valstar, Edward R

    2015-02-01

    Waterjet cutting technology is considered a promising technology to be used for minimally invasive removal of interface tissue surrounding aseptically loose hip prostheses. The goal of this study was to investigate the feasibility of waterjet cutting of interface tissue membrane. Waterjets with 0.2 mm and 0.6 mm diameter, a stand-off distance of 5 mm, and a traverse speed of 0.5 mm/s were used to cut interface tissue samples in half. The water flow through the nozzle was controlled by means of a valve. By changing the flow, the resulting waterjet pressure was regulated. Tissue sample thickness and the required waterjet pressures were measured. Mean thickness of the samples tested within the 0.2 mm nozzle group was 2.3 mm (SD 0.7 mm) and within the 0.6 mm nozzle group 2.6 mm (SD 0.9 mm). The required waterjet pressure to cut samples was between 10 and 12 MPa for the 0.2 mm nozzle and between 5 and 10 MPa for the 0.6 mm nozzle. Cutting bone or bone cement requires about 3 times higher waterjet pressure (30-50 MPa, depending on used nozzle diameter) and therefore we consider waterjet cutting as a safe technique to be used for minimally invasive interface tissue removal. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  17. Attentional and visual demands for sprint performance in non-fatigued and fatigued conditions : reliability of a repeated sprint test

    NARCIS (Netherlands)

    Reininga, Inge H. F.; Lemmink, Koen A. P. M.; Diercks, Ron L.; Buizer, Arina T.; Stevens, Martin

    2010-01-01

    Background: Physical performance measures are widely used to assess physical function, providing information about physiological and biomechanical aspects of motor performance. However they do not provide insight into the attentional and visual demands for motor performance. A figure-of-eight sprint

  18. Guidelines for assigning allowable properties to visually graded foreign species based on test data from full sized specimens

    Science.gov (United States)

    David W. Green; Bradley E. Shelley

    2006-01-01

    The objective of this document is to provide philosophy and guidelines for the assignment of allowable properties to visually graded dimension lumber produced from trees not grown in the United States. This document assumes, as a starting point, the procedures of ASTM D 1990.

  19. Quantifying the visual perception skills of pre-school testees using a novel tangible electronic test instrument

    CSIR Research Space (South Africa)

    Smith, Andrew C

    2008-11-01

    Full Text Available an assessment instrument that directly measures pre-school children’s visual perception skills that form part of literacy skills, as defined in the Persona Object Model in order to provide information that could contribute to the design of appropriate game...

  20. Normalizing the Bender Visual-Motor Gestalt Test for 4 to 7 Years Old Children of Tehran, Iran

    Directory of Open Access Journals (Sweden)

    Siamak Tahmasebi

    2016-04-01

    Conclusion Consistent with Koppit’z maturational hypothesis and previous studies (Iranian and foreign, our results showed visual-motor improvement of perceptual performance with increasing age. In conclusion, koppitz scoring system is applicable to Iranian children protocols.

  1. Computer Aided Stroke-by-Stroke Visualization of Actual and Target Power Allows for Continuously Increasing Ramp Tests on Wind-Braked Rowing Ergometers.

    Science.gov (United States)

    Treff, Gunnar; Winkert, Kay; Machus, Katja; Steinacker, Jürgen M

    2017-10-16

    Ramp tests are continuously increasing exercise tests used for determination of maximal oxygen uptake (⩒O 2 max), which is identifiable by a plateau in ⩒O 2 despite increasing mechanical power output (LOAD). On wind-braked rowing ergometers (RowErg) it is hardly feasible to ensure a continuous increase in LOAD until test termination, because neither resistance nor stroke-frequency are externally adjustable, but depend on the rower. To enable ramp tests on rowing ergometers, we produced visual stroke-by-stroke feedback showing target and actual LOAD to the rower. The software supports automatic test termination (TERM auto ) if LOAD ceases to increase. We aimed to evaluate linearity of the LOAD-increment and calculate the difference between TERM auto and test duration at subjective exhaustion (TERM exhaust ). Twenty-eight highly trained male rowers performed a ramp test until subjective exhaustion on RowErg, targeting an increment of 35W•min -1 . LOAD was measured as work per time via external force and position sensors and visualized on a computer screen. TERM auto was deactivated, but all data were logged. Test duration at TERM exhaust was subsequently compared with virtual test duration at TERM auto calculated from the log files. Regression between time and LOAD was y=167+34.6W (r=.99). Individual correlations ranged from .97 to 1.0. TERM auto caused 12-35s shorter test durations than TERM exhaust in four rowers, leading to underestimation in ⩒O 2 max of 1.2% and 3.7% in two rowers. This setup allows one to perform ramp tests on RowErg with continuously increasing LOAD until TERM auto . In particular cases ⩒O2max might be slightly underestimated at TERM auto .

  2. Fracture Load Before and After Veneering Zirconia Posterior Fixed Dental Prostheses.

    Science.gov (United States)

    Rodríguez, Verónica; Castillo-Oyagüe, Raquel; López-Suárez, Carlos; Gonzalo, Esther; Peláez, Jesús; Suárez-García, María-Jesús

    2016-10-01

    To evaluate the fracture load of 3-unit zirconia-based posterior fixed dental prostheses (FDPs) before and after veneering the frameworks. Forty standardized stainless-steel master dies were fabricated (height: 5 mm, convergence: 6º, chamfer: 1 mm) and randomly screwed in pairs onto metal bases. The bases were randomly divided into two groups (n = 20 each) according to the zirconia CAD/CAM system used for constructing 3-unit structures for FDPs: group 1 (L): Lava All-ceramic, group 2 (Z): IPS e.max ZirCAD. Half of the zirconia structures per group were randomly selected and veneered, while the remaining half was left unveneered. The specimens were luted in standard fashion onto the stainless steel master dies using conventional glass ionomer cement. All specimens were tested for fracture load (FL). Specimens were subjected to a three-point bending test until fracture by applying an axial compressive load at the central fossa of the pontics with a universal testing machine at a 0.5 mm/min crosshead speed. Wilcoxon's rank-sum test and Weibull statistics were used for statistical analysis (α = 0.05). L structures recorded significantly higher values of load to fracture than the Z group both before and after veneering. Within each ceramic group, no differences were found between unveneered and veneered frameworks. Although further studies are necessary to corroborate these findings, both zirconia systems could be recommended for restoring posterior teeth on the basis of the fracture load values recorded in this experiment (>1000 N). The veneering procedure did not affect the overall load to fracture in any group. © 2015 by the American College of Prosthodontists.

  3. Quantification of Emphysema with a Three-Dimensional Chest CT Scan: Correlation with the Visual Emphysema Scoring on Chest CT, Pulmonary Function Tests and Dyspnea Severity

    International Nuclear Information System (INIS)

    Park, Hyun Jeong; Hwang, Jung Hwa

    2011-01-01

    We wanted to prospectively evaluate the correlation between the quantification of emphysema using 3D CT densitometry with the visual emphysema score, pulmonary function tests (PFT) and the dyspnea score in patients with chronic obstructive pulmonary disease (COPD). Non-enhanced chest CT with 3D reconstruction was performed in 28 men with COPD (age 54-88 years). With histogram analysis, the total lung volume, mean lung density and proportion of low attenuation lung volume below predetermined thresholds were measured. The CT parameters were compared with the visual emphysema score, the PFT and the dyspnea score. A low attenuation lung volume below -950 HU was well correlated with the DLco and FEV 1 /FVC. A Low attenuation lung volume below -950 HU and -930 HU was correlated with visual the emphysema score. A low attenuation lung volume below -950 HU was correlated with the dyspnea score, although the correlations between the other CT parameters and the dyspnea score were not significant. Objective quantification of emphysema using 3D CT densitometry was correlated with the visual emphysema score. A low attenuation lung volume below -950 HU was correlated with the DLco, the FEV 1 /FVC and the dyspnea score.

  4. Quantification of Emphysema with a Three-Dimensional Chest CT Scan: Correlation with the Visual Emphysema Scoring on Chest CT, Pulmonary Function Tests and Dyspnea Severity

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyun Jeong; Hwang, Jung Hwa [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Seoul (Korea, Republic of)

    2011-09-15

    We wanted to prospectively evaluate the correlation between the quantification of emphysema using 3D CT densitometry with the visual emphysema score, pulmonary function tests (PFT) and the dyspnea score in patients with chronic obstructive pulmonary disease (COPD). Non-enhanced chest CT with 3D reconstruction was performed in 28 men with COPD (age 54-88 years). With histogram analysis, the total lung volume, mean lung density and proportion of low attenuation lung volume below predetermined thresholds were measured. The CT parameters were compared with the visual emphysema score, the PFT and the dyspnea score. A low attenuation lung volume below -950 HU was well correlated with the DLco and FEV{sub 1}/FVC. A Low attenuation lung volume below -950 HU and -930 HU was correlated with visual the emphysema score. A low attenuation lung volume below -950 HU was correlated with the dyspnea score, although the correlations between the other CT parameters and the dyspnea score were not significant. Objective quantification of emphysema using 3D CT densitometry was correlated with the visual emphysema score. A low attenuation lung volume below -950 HU was correlated with the DLco, the FEV{sub 1}/FVC and the dyspnea score.

  5. Dentistry investigations of teeth and dental prostheses using OCT

    Science.gov (United States)

    Sinescu, C.; Duma, V.-F.; Canjau, S.; Dobre, G.; Demian, D.; Cernat, R.; Negrutiu, M. L.; Todea, C.; Topala, F. I.; Hutiu, Gh.; Bradu, A.; Podoleanu, A. G.

    2016-04-01

    We present some of our recent investigations in Dental Medicine using Optical Coherence Tomography (OCT). Time Domain (TD), Spectral Domain (SD), and Swept Source (SS) OCT in-house developed systems are being used, for both ex vivo and in vivo investigations in the oral cavity. We study ex vivo the interface between the tooth and the dental sealant and demonstrate the limitations of the X-rays investigations that are now the gold standard for such procedures. Using OCT, defects in the interface that cannot be identified in radiographs can be determined both as position and magnitude. The drilling process of teeth can also be characterized in real time using OCT, to monitor the remaining dentin thickness (RDT) in order to avoid opening the pulp chamber. We demonstrate in this respect that an RDT of 0.5 mm is the minimum value to assure the integrity of the dentin wall between the drilled cavity and the pulp chamber; at an RDT of 0.3 mm or less a fracture is initiated, the dentin is punctured and endodontic treatment must follow. In vivo OCT investigations in the oral cavity were also performed (i.e., for metalloceramic prostheses and for ceramic inlay tooth interfaces), with the low cost, light weight and versatile handheld probes with 1D galvoscanners that we have developed and applied for a range of in-house developed OCT systems, in various clinical applications. They are briefly discussed, as well as some of our current and future work in the field, including for studies of soft tissue in the mouth.

  6. A Study of Ossiculoplasty in Chronic Otitis Media using different types of Prostheses

    Directory of Open Access Journals (Sweden)

    Parthapratim Laha

    2013-12-01

    Full Text Available Abstract Introduction: A wide range of prostheses, autologus and synthetic are available for use these days. Ideally, the ossicular reconstruction prosthesis should be biocompatible, safe, easy to handle and capable of efficient sound transmission. Aim and objectives: To study operative ease and post-operative hearing results in patients undergoing ossiculoplasty with different types of prostheses. Materials and methods: A prospective randomized study of 25 patients with Chronic Otitis Media, undergoing ossiculoplasty was conducted at Command Hospital, Kolkata. Tragal cartilage was used in 05 patients, conchal cartilage in 05, refashioned incus in 05, hydroxyapatite in 05 and titanium prostheses in 05 patients. Subjects with mixed hearing loss, multiple co-morbidities and revision surgeries were excluded. Hearing assessment was done by pure tone audiometry pre-operatively and 04 and 12 weeks postoperatively. Results were analyzed statistically. Results: Using tragal or conchal cartilage took almost equal time as autologus incus. Using synthetic material saved time. Titanium prosthesis gives maximum surgical ease. Post-operative air-bone gap reduction within 20 dB was seen in all, irrespective of type of prostheses.  Conclusion: Surgical ease is considerably better with titanium prostheses; however hearing results are equally good in all.

  7. Esthetic, functional, and prosthetic outcomes with implant-retained finger prostheses.

    Science.gov (United States)

    Aydin, Cemal; Nemli, Secil Karakoca; Yilmaz, Handan

    2013-04-01

    Traumatic amputation of fingers results in a serious impairment of hand function and affects the psychological status of the patients. The implant-retained finger prostheses are an alternative treatment. The aim of this case report is to represent the use of osseointegrated implants for retention of finger prostheses in a patient with amputated thumb and index finger. Dental implants were placed in the residual bone of the fingers using two-stage surgery. Custom-made attachments were used to provide retention between implants and silicone prostheses. Prosthetic fingernails were made of composite resin material. After 6 months, implants were clinically successful, and the patient was satisfied with the appearance and the function of the prostheses. The complications of broken prosthetic nail and mild discoloration were observed. Reconstruction of amputated fingers with implant-retained prosthesis is a worthwhile treatment providing esthetic, functional, and psychological benefits, although some complications might be experienced. Clinical relevance Implant-retained finger prostheses are an acceptable treatment modality for patients with amputated fingers. Evaluating implant prognosis, functional results and prosthetic results of the patients are necessary to address the benefits and complications of the treatment.

  8. Fabrication of low cost soft tissue prostheses with the desktop 3D printer

    Science.gov (United States)

    He, Yong; Xue, Guang-Huai; Fu, Jian-Zhong

    2014-11-01

    Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods.

  9. Fabrication of low cost soft tissue prostheses with the desktop 3D printer

    Science.gov (United States)

    He, Yong; Xue, Guang-huai; Fu, Jian-zhong

    2014-01-01

    Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods. PMID:25427880

  10. Fabrication of low cost soft tissue prostheses with the desktop 3D printer.

    Science.gov (United States)

    He, Yong; Xue, Guang-huai; Fu, Jian-zhong

    2014-11-27

    Soft tissue prostheses such as artificial ear, eye and nose are widely used in the maxillofacial rehabilitation. In this report we demonstrate how to fabricate soft prostheses mold with a low cost desktop 3D printer. The fabrication method used is referred to as Scanning Printing Polishing Casting (SPPC). Firstly the anatomy is scanned with a 3D scanner, then a tissue casting mold is designed on computer and printed with a desktop 3D printer. Subsequently, a chemical polishing method is used to polish the casting mold by removing the staircase effect and acquiring a smooth surface. Finally, the last step is to cast medical grade silicone into the mold. After the silicone is cured, the fine soft prostheses can be removed from the mold. Utilizing the SPPC method, soft prostheses with smooth surface and complicated structure can be fabricated at a low cost. Accordingly, the total cost of fabricating ear prosthesis is about $30, which is much lower than the current soft prostheses fabrication methods.

  11. Zirconia-Based Screw-Retained Prostheses Supported by Implants: A Retrospective Study on Technical Complications and Failures.

    Science.gov (United States)

    Worni, Andreas; Kolgeci, Lumni; Rentsch-Kollar, Andrea; Katsoulis, Joannis; Mericske-Stern, Regina

    2015-12-01

    Little information is yet available on zirconia-based prostheses supported by implants. To evaluate technical problems and failures of implant-supported zirconia-based prostheses with exclusive screw-retention. Consecutive patients received screw-retained zirconia-based prostheses supported by implants and were followed over a time period of 5 years. The implant placement and prosthetic rehabilitation were performed in one clinical setting, and all patients participated in the maintenance program. The treatment comprised single crowns (SCs) and fixed dental prostheses (FDPs) of three to 12 units. Screw-retention of the CAD/CAM-fabricated SCs and FDPs was performed with direct connection at the implant level. The primary outcome was the complete failure of zirconia-based prostheses; outcome measures were fracture of the framework or extensive chipping resulting in the need for refabrication. A life table analysis was performed, the cumulative survival rate (CSR) calculated, and a Kaplan-Meier curve drawn. Two hundred and ninety-four implants supported 156 zirconia-based prostheses in 95 patients (52 men, 43 women, average age 59.1 ± 11.7 years). Sixty-five SCs and 91 FDPs were identified, comprising a total of 441 units. Fractures of the zirconia framework and extensive chipping resulted in refabrication of nine prostheses. Nearly all the prostheses (94.2%) remained in situ during the observation period. The 5-year CSR was 90.5%, and 41 prostheses (14 SCs, 27 FDPs) comprising 113 units survived for an observation time of more than 5 years. Six SCs exhibited screw loosening, and polishing of minor chipping was required for five prostheses. This study shows that zirconia-based implant-supported fixed prostheses exhibit satisfactory treatment outcomes and that screw-retention directly at the implant level is feasible. © 2014 Wiley Periodicals, Inc.

  12. Testing the effectiveness of a mentoring intervention to improve social participation of adolescents with visual impairments: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Heppe, Eline C M; Kef, Sabina; Schuengel, Carlo

    2015-11-05

    Social participation is challenging for people with visual impairments. As a result, on average, social networks are smaller, romantic relationships formed later, educational achievements lower, and career prospects limited. Adolescents on their way towards achieving these goals may benefit from the knowledge and experience of adults who have overcome similar difficulties. Therefore, a mentoring intervention, called Mentor Support, will be set up and studied in which adolescents with visual impairments are matched with successfully social participating adults with and without visual impairments. The main objective of this study is to evaluate the effectiveness of Mentor Support. Secondary aims are to distinguish the importance of the disability-specific experience of mentors, predictors of success, and mediating factors. The effect of Mentor Support will be tested in a randomized clinical trial, using pre-test one week before starting, post-test after 12 months, and follow-up after 18 months. Participants will be referred to one of the experimental groups or the control group, and this randomization will be stratified according to country region. Three groups are included in the trial: 40 participants will receive Mentor Support by mentors with a visual impairment in combination with care-as-usual, 40 participants will receive Mentor Support by mentors without visual impairments in combination with care-as-usual, and 40 participants will receive care-as-usual only. Mentor Support consists of 12 face-to-face meetings of the mentee with a mentor with an overall time period of one year. On a weekly basis, dyads have contact via email, the Internet, or telephone. The primary outcome measure is improved social participation within three domains (work/school, leisure activities, and social relationships). Mediator variables are psychosocial functioning and self-determination. Predictors such as demographics and personality are also investigated in order to distinguish

  13. Auditory and audio-visual processing in patients with cochlear, auditory brainstem, and auditory midbrain implants: An EEG study.

    Science.gov (United States)

    Schierholz, Irina; Finke, Mareike; Kral, Andrej; Büchner, Andreas; Rach, Stefan; Lenarz, Thomas; Dengler, Reinhard; Sandmann, Pascale

    2017-04-01

    There is substantial variability in speech recognition ability across patients with cochlear implants (CIs), auditory brainstem implants (ABIs), and auditory midbrain implants (AMIs). To better understand how this variability is related to central processing differences, the current electroencephalography (EEG) study compared hearing abilities and auditory-cortex activation in patients with electrical stimulation at different sites of the auditory pathway. Three different groups of patients with auditory implants (Hannover Medical School; ABI: n = 6, CI: n = 6; AMI: n = 2) performed a speeded response task and a speech recognition test with auditory, visual, and audio-visual stimuli. Behavioral performance and cortical processing of auditory and audio-visual stimuli were compared between groups. ABI and AMI patients showed prolonged response times on auditory and audio-visual stimuli compared with NH listeners and CI patients. This was confirmed by prolonged N1 latencies and reduced N1 amplitudes in ABI and AMI patients. However, patients with central auditory implants showed a remarkable gain in performance when visual and auditory input was combined, in both speech and non-speech conditions, which was reflected by a strong visual modulation of auditory-cortex activation in these individuals. In sum, the results suggest that the behavioral improvement for audio-visual conditions in central auditory implant patients is based on enhanced audio-visual interactions in the auditory cortex. Their findings may provide important implications for the optimization of electrical stimulation and rehabilitation strategies in patients with central auditory prostheses. Hum Brain Mapp 38:2206-2225, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Initial Evaluations of Mainstream Personality Tests for Use with Visually Impaired Adults in Vocational Assessment and Guidance.

    Science.gov (United States)

    Reid, Juliet

    2000-01-01

    This article reviews the Eysenck Personality Questionnaire-Revised (EPQ-R adult and EPQ-R short form), the 16PF5, and the Myers-Briggs Type Indicator for use with adults with visual impairments. Results found only the EPQ-R short form can be used by participants using low vision aids, closed-circuit television, or an optical character reader.…

  15. Haptic-2D: A new haptic test battery assessing the tactual abilities of sighted and visually impaired children and adolescents with two-dimensional raised materials.

    Science.gov (United States)

    Mazella, Anaïs; Albaret, Jean-Michel; Picard, Delphine

    2016-01-01

    To fill an important gap in the psychometric assessment of children and adolescents with impaired vision, we designed a new battery of haptic tests, called Haptic-2D, for visually impaired and sighted individuals aged five to 18 years. Unlike existing batteries, ours uses only two-dimensional raised materials that participants explore using active touch. It is composed of 11 haptic tests, measuring scanning skills, tactile discrimination skills, spatial comprehension skills, short-term tactile memory, and comprehension of tactile pictures. We administered this battery to 138 participants, half of whom were sighted (n=69), and half visually impaired (blind, n=16; low vision, n=53). Results indicated a significant main effect of age on haptic scores, but no main effect of vision or Age × Vision interaction effect. Reliability of test items was satisfactory (Cronbach's alpha, α=0.51-0.84). Convergent validity was good, as shown by a significant correlation (age partialled out) between total haptic scores and scores on the B101 test (rp=0.51, n=47). Discriminant validity was also satisfactory, as attested by a lower but still significant partial correlation between total haptic scores and the raw score on the verbal WISC (rp=0.43, n=62). Finally, test-retest reliability was good (rs=0.93, n=12; interval of one to two months). This new psychometric tool should prove useful to practitioners working with young people with impaired vision. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. CAD/CAM milled complete removable dental prostheses: An in vitro evaluation of biocompatibility, mechanical properties, and surface roughness.

    Science.gov (United States)

    Srinivasan, Murali; Gjengedal, Harald; Cattani-Lorente, Maria; Moussa, Mira; Durual, Stéphane; Schimmel, Martin; Müller, Frauke

    2018-03-06

    This study compared the biocompatibility, mechanical properties, and surface roughness of a pre-polymerized polymethyl methacrylate (PMMA) resin for CAD/CAM complete removable dental prostheses (CRDPs) and a traditional heat-polymerized PMMA resin. Two groups of resin substrates [Control (RC): conventional PMMA; Test (RA): CAD/CAM PMMA] were fabricated. Human primary osteoblasts and mouse embryonic-fibroblasts were cultured for biocompatibility assays. Mechanical properties and surface roughness were compared. ANOVA revealed no difference between the resin groups in the biocompatibility assays. RA demonstrated a higher elastic modulus (p=0.002), young's modulus (p=0.002), plastic energy (p=0.002), ultimate strength (p=0.0004), yield point (p=0.016), strain at yield point (p=0.037), and toughness (pCAD/CAM resin was equally biocompatible and presented with improved mechanical properties than the traditional heat-polymerized PMMA resin used in the fabrication of CRDPs.

  17. Comparison of Clinical Efficacy Between Modular Cementless Stem Prostheses and Coated Cementless Long-Stem Prostheses on Bone Defect in Hip Revision Arthroplasty.

    Science.gov (United States)

    Li, Huibin; Chen, Fang; Wang, Zhe; Chen, Qian

    2016-02-29

    BACKGROUND The aim of this study was to investigate and compare the clinical efficacy of modular cementless stem and coated cementless long-stem prostheses in hip revision arthroplasty. MATERIAL AND METHODS Sixty-five patients with complete hip revision surgery data during January 2005 to March 2015 were selected from the People's Hospital of Linyi City and randomly divided into a S-ROM group (implanted with cementless modular stem prostheses, n=32) and a SLR-PLUS group (implanted with cementless coated long-stem prostheses, n=33). Harris score was used to evaluate the hip function of the patients in order to measure the clinical efficacy of the prostheses in total hip arthroplasty. Anteroposterior pelvic radiographs and lateral pelvic radiographs were taken and each patient's hip arthroplasty condition was recorded. Kaplan-Meier method was applied to compare the cumulative 5-year non-revision rate between the 2 prostheses and log-rank method was used to inspect the statistical data. RESULTS The Harris scores of both the S-ROM group and the SLR-PLUS group were significantly higher at 12 months after the operation than those before the operation (both P0.05), while the Harris scores of the patients with type IIIA/IIIB in the S-ROM group were both significantly higher than those of the same types in the SLR-PLUS group at 3 months, 6 months, and 12 months after the operation (all Prevision rate between the type I/II patients in the S-ROM group (92.31%) and the patients of the same types in the SLR-PLUS group (85.71%) (P>0.05). However, the cumulative 5-year non-revision rate of the type IIIA/IIIB patients in the S-ROM group (89.47%) was significantly different from the patients of the same types in the SLR-PLUS group (42.11%) (Phip revision arthroplasty were clinically more effective in the treatment of type IIIA and IIIB bone defects than the coated long-stem prostheses according to the Harris score and the cumulative 5-year non-revision rate.

  18. Progress in the clinical development and utilization of vision prostheses: an update

    Directory of Open Access Journals (Sweden)

    Brandli A

    2016-05-01

    Full Text Available Alice Brandli, Chi D Luu, Robyn H Guymer, Lauren N Ayton Centre for Eye Research Australia, Department of Surgery (Ophthalmology, The University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia Abstract: Vision prostheses, or “bionic eyes”, are implantable medical bionic devices with the potential to restore rudimentary sight to people with profound vision loss or blindness. In the past two decades, this field has rapidly progressed, and there are now two commercially available retinal prostheses in the US and Europe, and a number of next-generation devices in development. This review provides an update on the development of these devices and a discussion on the future directions for the field. Keywords: vision prostheses, bionic eye, vision restoration, blindness, medical bionics, retinitis pigmentosa

  19. Prueba neuropsicológica para medir la inteligencia: utilización del test de retención visual de Benton

    OpenAIRE

    Guerra Barrera, Susana

    2016-01-01

    La tesis estudia la relación entre la inteligencia psicométrica y la memoria de trabajo visual y habilidades visuoconstructivas en el marco del desarrollo evolutivo entre los 5 y los 8 años, a partir de la aplicación del Test de Retención Visual de Benton y las escalas Wechsler y Stanford-Binet, en función de la edad cronológica, género y nivel de CI. Con una amplia y significativa muestra de sujetos recogida a lo largo de diez años, de los cuáles más de 50 presentaban un CI por encima de...

  20. Prevention of biofilm formation by dairy products and N-acetylcysteine on voice prostheses in an artificial throat

    NARCIS (Netherlands)

    Schwandt, LQ; Van Weissenbruch, R; Stokroos, [No Value; Van der Mei, HC; Busscher, HJ; Albers, FWJ

    Objective - To evaluate the preventive effect of buttermilk, Yakult Light fermented milk drink and N-acetylcysteine on biofilm formation on voice prostheses in vitro. Material and Methods - Groningen button and Provox(R) 2 voice prostheses were inoculated with a mixture of bacteria and yeasts

  1. Adhesion to silicone rubber of yeasts and bacteria isolated from voice prostheses : Influence of salivary conditioning films

    NARCIS (Netherlands)

    Busscher, HJ; GeertsemaDoornbusch, GI; vanderMei, HC

    Adhesion of yeasts and bacteria to silicone rubber is one of the first steps in the biodeterioration of silicone rubber voice prostheses. In this paper, adhesion of two streptococcal, staphylococcal, Candida albicans and Candida tropicalis strains, isolated from explanted voice prostheses was

  2. Interference in adhesion of bacteria and yeasts isolated from explanted voice prostheses to silicone rubber by rhamnolipid biosurfactants.

    Science.gov (United States)

    Rodrigues, L R; Banat, I M; van der Mei, H C; Teixeira, J A; Oliveira, R

    2006-03-01

    The effects and extent of adhesion of four different bacterial and two yeast strains isolated from explanted voice prostheses to silicone rubber with and without an adsorbed rhamnolipid biosurfactant layer obtained from Pseudomonasaeruginosa DS10-129 was studied. The ability of rhamnolipid biosurfactant to inhibit adhesion of micro-organisms to silicone rubber was investigated in a parallel-plate flow chamber. The anti-adhesive activity of the biosurfactant at different concentrations was significant against all the strains and depended on the micro-organism tested. The results showed an effective reduction in the initial deposition rates, and the number of bacterial cells adhering after 4 h, for all micro-organisms tested at the 4 g l(-1) undiluted rhamnolipid solution. Maximum initial reduction of adhesion rate (an average of 66%) occurred for Streptococcus salivarius GB 24/9 and Candida tropicalis GB 9/9. The number of cells adhering after 4 h on silicone rubber conditioned with biosurfactant was reduced to 48% for Staphylococcus epidermidis GB 9/6, Strep. salivarius GB 24/9, Staphylococcus aureus GB 2/1 and C. tropicalis GB 9/9 in comparison to controls. Perfusing the flow chamber with biosurfactant containing solution followed by the passage of a liquid-air interface, to investigate detachment of micro-organisms adhering to silicone rubber, produced high detachment (96%) of adhered cells for all micro-organisms studied, except for Staph. aureus GB 2/1 (67%). It is concluded that biosurfactant represent suitable compounds that should be considered in developing future strategies to prevent the microbial colonization of silicone rubber voice prostheses.

  3. New total ossicular replacement prostheses with a resilient joint: experimental data from human temporal bones.

    Science.gov (United States)

    Arechvo, Irina; Bornitz, Matthias; Lasurashvili, Nikoloz; Zahnert, Thomas; Beleites, Thomas

    2012-01-01

    New flexible total ossicular prostheses with an integrated microjoint can compensate for large static displacements in the reconstructed ossicular chain. When properly designed, they can mimic the function of the joints of the intact chain and ensure good vibration transfer in both straight and bent conditions. Prosthesis dislocations and extrusions are frequently observed after middle ear surgery. They are mainly related to the altered distance between the coupling points because of large static eardrum displacements. The new prostheses consist of 2 titanium shafts, which are incorporated into a silicone body. The sound transfer function and stapes footplate displacement at static loads were evaluated in human temporal bones after ossicular reconstruction using prostheses with 2 different silicones with different hardness values. The stiffness and bending characteristics of the prostheses were investigated with a quasi-static load. The sound transfer properties of the middle ears with the prostheses inserted under uncompressed conditions were comparable with those of ears with intact ossicular chains. The implant with the soft silicone had improved acoustic transfer characteristics over the implant with the hard silicone in a compressed state. In the quasi-static experiments, the minimum medial footplate displacement was found with the same implant. The bending characteristics depended on the silicone stiffness and correlated closely with the point and angle of the load incidence. The titanium prostheses with a resilient joint that were investigated in this study had good sound transfer characteristics under optimal conditions as well as in a compressed state. As a result of joint bending, the implants compensate for the small changes in length of the ossicular chain that occur under varying middle ear pressure. The implants require a stable support at the stapes footplate to function properly.

  4. All-ceramic inlay-retained fixed dental prostheses: An update.

    Science.gov (United States)

    Chaar, M Sad; Passia, Nicole; Kern, Matthias

    2015-10-01

    Inlay-retained fixed dental prostheses (IRFDPs) represent a minimally invasive alternative to conventional fixed dental prostheses (FDPs) to replace single posterior missing teeth. The aim of the present review article is to assess the clinical outcome of different IRFDPs in order to derive recommendations regarding their clinical application. Hence, it is essential to highlight important factors that influence the longevity and success of IRFDPs, such as treatment plan, appropriate case selection with proper indications, as well as tooth preparation. Furthermore, a good understanding of bonding technologies and awareness of pretreatment procedures for different materials are indispensable for the long-term success of IRFDPs.

  5. Integral data test of HENDL1.0/MG and visualBUS with neutronics shielding experiments. Pt.1

    International Nuclear Information System (INIS)

    Gao Chunjing; Deng Tieru; Xu Dezheng; Li Jingjing; Wu Yican

    2004-01-01

    HENDL1.0/MG, a multi-group working library of the Hybrid Evaluated Nuclear Data Library, was home-developed by the FDS Team of ASIPP (Institute of Plasma Physics, Chinese Academy of Sciences) on the basis of several national data libraries. To validate and qualify the process of producing HENDL1.0/MG, simulating calculations of a series of existent spherical shell benchmark experiments (Al, Mo, Co, Ti, Mn, W, Be and V) have been performed with HENDL1.0/MG and the multifunctional neutronics code system named VisualBUS home-developed also by FDS Team. (authors)

  6. The role of welding techniques in the biomechanical behavior of implant-supported prostheses.

    Science.gov (United States)

    Rodrigues, Sabrina Alessandra; Presotto, Anna Gabriella Camacho; Barão, Valentim Adelino Ricardo; Consani, Rafael Leonardo Xediek; Nóbilo, Mauro Antônio Arruda; Mesquita, Marcelo Ferraz

    2017-09-01

    This in vitro study investigated the role of welding techniques of implant-supported prostheses in the 2D and 3D marginal misfits of prosthetic frameworks, strain induced on the mini abutment, and detorque of prosthetic screws. The correlations between the analyzed variables were also investigated. Frameworks were cast in commercially pure titanium (cp-Ti). A marginal misfit of 200μm was simulated in the working models (control group) (n=20). The 2D marginal misfit was analyzed according to the single-screw test protocol using a precision optical microscope. The 3D marginal misfit was performed by X-ray microtomography. Strain gauge analysis was performed to investigate the strain induced on the mini abutment. A digital torque meter was used for analysis of the detorque and the mean value was calculated for each framework. Afterwards, the frameworks were divided into two experimental groups (n=10): Laser (L) and TIG (T). The welding techniques were performed according to the following parameters: L (390V/9ms); T (36A/60ms). The L and T groups were reevaluated according to the marginal misfit, strain, and detorque. The results were submitted to one-way ANOVA followed by Tukey's HSD test and Person correlation analysis (α=0.05). Welding techniques statistically reduced the 2D and 3D marginal misfits of prosthetic frameworks (p0.05). Positive correlations were observed between 2D and 3D marginal misfit reading methods (r=0.943, pwelding techniques improved the biomechanical behavior of the implant-supported system. TIG can be an acceptable and affordable technique to reduce the misfit of 3-unit Ti frameworks. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Longevity of resin-bonded fixed partial dental prostheses made with metal alloys.

    Science.gov (United States)

    Tanoue, Naomi

    2016-07-01

    The purpose of this study was to evaluate the clinical performance of resin-bonded fixed partial dental prostheses (RBFPDPs) made with metal alloys. The retention of 311 RBFPDPs from 226 patients fabricated from 1983 to 2013 using an adhesive resin was clinically evaluated. Partial or complete debonding of the RBFPDP or framework fracture was considered a treatment failure. All data were obtained from clinical examinations, and missing data were censored at the date of the last available information. The effect of the following factors on survival rate were investigated: patient gender, location (maxilla/mandible and anterior/posterior), number of missing teeth, number of abutment teeth, framework structure, type of metal alloy, patient age at the point of cementation, cement type, and distinction of the treating dentist. Data were analyzed with the Kaplan-Meier survival tests, log-rank tests, and Cox regression analyses (α = 0.05). The Kaplan-Meier survival rate was 41.2 % ± 6.5 % (standard error) at 28.8 years (last outcome event). Significant differences were found for patient age and treating dentist (p < 0.05). The risk of failure in younger patients was 1.7 times greater than that in older patients and that of inexperienced dentists was 2.0 times greater than that of dentist experienced and specialized in adhesive dentistry. When fabricating RBFPDPs for younger patients, mechanical preparation for bonding may be necessary in consideration of the risk for debonding. Experienced dentists may achieve better results. Mastery of skills is necessary to ensure excellent prognoses for RBFPDPs.

  8. Effect of an experimental silica-nylon reinforcement on the fracture load and flexural strength of bisacrylic interim partial fixed dental prostheses.

    Science.gov (United States)

    Almeida, Carolina Souza; Amaral, Marina; de Cássia Papaiz Gonçalves, Fernanda; de Arruda Paes-Junior, Tarcisio José

    2016-03-01

    Materials used in the fabrication of interim restorations usually have mechanical properties inferior to those used in definitive prostheses. Various techniques may be used to reinforce these materials. The purpose of this in vitro study was to evaluate the fracture strength of interim partial fixed dental prostheses (FDPs) with and without an experimental silica-nylon reinforcement placed in different orientations (horizontal or vertical) before and after thermocycling and to evaluate the flexural strength of the bisacrylic resin used for fabricating these prostheses. For fracture strength testing, 72 four-unit interim partial FDPs were fabricated from bisacrylic resin and divided into 3 groups: no reinforcement, horizontal reinforcement, and vertical reinforcement. Half of the specimens from each group were thermocycled before testing (1000 cycles between 5°C and 55°C) (n=12). An increasing load was applied to the center of the prosthesis until fracture. The flexural strength of bisacrylic resin reinforced with the experimental mesh was measured by using a 3-point bending test with 25×10.5×3.3 mm bars of resin, with or without thermocycling. The results were evaluated with analysis of variance and Kaplan-Meier survival analysis (α=.05). The results showed that incorporating the experimental silica-nylon reinforcement in a horizontal orientation provided the highest values of fracture strength for the 4-unit partial FDPs. Reinforcement also enhanced the flexural strength values of bisacrylic resin bars. Silica-nylon reinforcement is an effective method of increasing the strength of interim restorations. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  9. Patient-Reported and Clinical Outcomes of Implant-Supported Fixed Complete Dental Prostheses: A Comparison of Metal-Acrylic, Milled Zirconia, and Retrievable Crown Prostheses.

    Science.gov (United States)

    Box, Virginia Hogsett; Sukotjo, Cortino; Knoernschild, Kent L; Campbell, Stephen D; Afshari, Fatemeh S

    2018-02-01

    The purpose of this retrospective study was to assess the incidence of biologic and technical complications for implant-supported fixed complete dental prostheses (IFCDPs) and their relationship to oral health-related quality of life (OHQoL) and patient-reported outcomes. Metal-acrylic (MA), retrievable crown (RC), monolithic zirconia (MZ), and porcelain veneered zirconia (PVZ) prostheses were included. Patients who received an IFCDP at least 1 year prior to recall were identified. Exclusion criteria were: (1) an opposing complete denture and (2) time in service >70 months. A total of 37 patients with 49 prostheses, including 22 MA, 14 RC, 7 MZ, and 6 PVZ prostheses were recalled. Patient-reported outcomes were assessed via OHIP-49 (Oral Health Impact Profile) and a scripted interview with open-ended questions. All designs had high complication rates (12 of 22 MA, 10 of 14 RC, 2 of 7 MZ, and 5 of 6 PVZ). The most common complications were: (1) MA: posterior tooth wear, (2) RC: chipping and fracturing of the restorations, (3) MZ: wear of opposing restorations, and (4) PVZ: chipping of opposing restorations. Average OHIP-49 scores ranged from 7 to 29, indicating high OHQoL, patient satisfaction, regardless of prosthetic design ( P = .16). The standardized interview highlighted that although most patients were extremely satisfied (73%), some continued to be bothered by material bulk (14%) and felt that maintenance of oral hygiene was excessively time-consuming (16%). In the context of this study, despite high complication rates and maintenance needs, all IFCDP designs resulted in high OHQoL and patient satisfaction.

  10. Immediately loaded mandibular fixed implant prostheses using the all-on-four protocol: a report of 183 consecutively treated patients with 1 year of function in definitive prostheses.

    Science.gov (United States)

    Galindo, Daniel F; Butura, Caesar C

    2012-01-01

    The purpose of this study was to evaluate a specific protocol using four implants to support immediately loaded fixed prostheses to restore edentulous and partially edentulous mandibles and report on the outcome after 1 year of function with the definitive prostheses. A retrospective study was conducted of all patients who were treated between June 2008 and December 2010 with fixed prostheses that were loaded immediately after placement of implants. The provisional prostheses were later replaced with computer-aided design/computer-assisted manufacture titanium frames supporting acrylic resin and denture teeth in the definitive prosthesis. All patients were followed for a minimum of 12 months and were assessed for implant survival and prosthetic performance, with descriptive statistics utilized to demonstrate results. One hundred eighty-three consecutive patients received immediately loaded axial and tilted implants according to the defined protocol. One implant failed, resulting in a 99.86% implant success rate. There were two catastrophic prosthetic failures (fracture of the titanium framework), for a 98.9% prosthetic success rate. Three patients (1.6%) presented with fracture of a prosthetic mandibular incisor tooth. No prosthetic screw loosening or fractures were seen. Radiographic evaluation revealed no major bone loss around dental implants. Based on this retrospective study, the following conclusions can be drawn: (1) this technique appears to provide a highly predictable implant performance; (2) it is necessary to critically evaluate framework design, especially around the connectors for cantilever extensions around the most distal implants; and (3) minor complications related to acrylic resin tooth fracture may be anticipated during the early phases of prosthetic treatment.

  11. SWS2 visual pigment evolution as a test of historically contingent patterns of plumage color evolution in warblers.

    Science.gov (United States)

    Bloch, Natasha I; Morrow, James M; Chang, Belinda S W; Price, Trevor D

    2015-02-01

    Distantly related clades that occupy similar environments may differ due to the lasting imprint of their ancestors-historical contingency. The New World warblers (Parulidae) and Old World warblers (Phylloscopidae) are ecologically similar clades that differ strikingly in plumage coloration. We studied genetic and functional evolution of the short-wavelength-sensitive visual pigments (SWS2 and SWS1) to ask if altered color perception could contribute to the plumage color differences between clades. We show SWS2 is short-wavelength shifted in birds that occupy open environments, such as finches, compared to those in closed environments, including warblers. Phylogenetic reconstructions indicate New World warblers were derived from a finch-like form that colonized from the Old World 15-20 Ma. During this process, the SWS2 gene accumulated six substitutions in branches leading to New World warblers, inviting the hypothesis that passage through a finch-like ancestor resulted in SWS2 evolution. In fact, we show spectral tuning remained similar across warblers as well as the finch ancestor. Results reject the hypothesis of historical contingency based on opsin spectral tuning, but point to evolution of other aspects of visual pigment function. Using the approach outlined here, historical contingency becomes a generally testable theory in systems where genotype and phenotype can be connected. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  12. Ontogenetic improvement of visual function in the medaka Oryzias latipes based on an optomotor testing system for larval and adult fish

    Science.gov (United States)

    Carvalho, Paulo S. M.; Noltie, Douglas B.; Tillitt, D.E.

    2002-01-01

    We developed a system for evaluation of visual function in larval and adult fish. Both optomotor (swimming) and optokinetic (eye movement) responses were monitored and recorded using a system of rotating stripes. The system allowed manipulation of factors such as width of the stripes used, rotation speed of the striped drum, and light illuminance levels within both the scotopic and photopic ranges. Precise control of these factors allowed quantitative measurements of visual acuity and motion detection. Using this apparatus, we tested the hypothesis that significant posthatch ontogenetic improvements in visual function occur in the medaka Oryzias latipes, and also that this species shows significant in ovo neuronal development. Significant improvements in the acuity angle alpha (ability to discriminate detail) were observed from approximately 5 degrees at hatch to 1 degree in the oldest adult stages. In addition, we measured a significant improvement in flicker fusion thresholds (motion detection skills) between larval and adult life stages within both the scotopic and photopic ranges of light illuminance. Ranges of flicker fusion thresholds (X±SD) at log I=1.96 (photopic) varied from 37.2±1.6 cycles/s in young adults to 18.6±1.6 cycles/s in young larvae 10 days posthatch. At log I=−2.54 (scotopic), flicker fusion thresholds varied from 5.8±0.7 cycles/s in young adults to 1.7±0.4 cycles/s in young larvae 10 days posthatch. Light sensitivity increased approximately 2.9 log units from early hatched larval stages to adults. The demonstrated ontogenetic improvements in visual function probably enable the fish to explore new resources, thereby enlarging their fundamental niche.

  13. A comparative analysis of metal allergens associated with dental alloy prostheses and the expression of HLA-DR in gingival tissue.

    Science.gov (United States)

    Zhang, Xin; Wei, Li-Cheng; Wu, Bin; Yu, Li-Ying; Wang, Xiao-Ping; Liu, Yue

    2016-01-01

    The present study aimed to provide guidance for the selection of prosthodontic materials and the management of patients with a suspected metal allergy. This included a comparison of the sensitivity of patients to alloys used in prescribed metal‑containing prostheses, and correlation analysis between metal allergy and accompanying clinical symptoms of sensitized patients using a patch test. The results from the patch test and metal component analyses were processed to reach a final diagnosis. In the present study, four dental alloys were assessed. Subsequent to polishing the surface of a metal restoration, the components were analyzed using an X‑ray fluorescence microscopy and spectrometry. Immunohistochemical analysis, reverse transcription‑polymerase chain reaction and western blotting were used to detect the expression levels of human leukocyte antigen (HLA)‑DR in gingival tissues affected by alloy restoration, and in normal gingival tissue samples. Positive allergens identified in the patch test were consistent with the components of the metal prostheses. The prevalence of nickel (Ni) allergy was highest (22.8%), and women were significantly more allergic to palladium and Ni than men (Palloy, gold alloy and titanium alloy. In conclusion, dentists require an understanding of the corrosion and allergy rates of prescribed alloys, in order to reduce the risk of allergic reactions. Patch testing for hypersensitive patients is recommended and caution is required when planning to use different alloys in the mouth.

  14. Effect of multi-adhesive layering on retention of extraoral maxillofacial silicone prostheses in vivo.

    Science.gov (United States)

    Kiat-Amnuay, Sudarat; Gettleman, Lawrence; Goldsmith, L Jane

    2004-09-01

    Loss of retention of maxillofacial prostheses often makes the margin visible or the prosthesis dislodge. Using several medical adhesives in combination may improve retention. The purpose of this study was to investigate the effect of single- and multi-adhesive layering of 2 adhesives on the retention of maxillofacial silicone elastomer strips adhered to the skin of human forearms using a peel test. Power analysis from a previous study and a pilot trial specified at least 20 subjects. Eight Silastic Adhesive A/MDX4-4210 silicone rubber strips (N=240) were applied in a predetermined random order to the left and right ventral forearms of 30 IRB-approved human subjects. Skin-Prep Protective Dressing was applied. Secure 2 Medical Adhesive (SMA) and Epithane-3 (E3) adhesive were used alone or as SMA/E3 or E3/SMA sandwiches (from skin to prosthesis) to adhere strips. Strips were peeled 6 hours later in a universal testing machine at 10 cm/min and data reported in N/m. Paired t tests were used to evaluate left and right arm differences. A Friedman test for nonparametric correlated data with within-subject design was performed, determining differences between both adhesives singly and in combination (alpha=.05). Tests of left-right differences were insignificant ( P =0.43), so the data from both arms were combined. Many strips with E3 did not adhere before testing and were counted as 0 adhesion. Median peel strengths (and 25th and 75th percentiles) in N/m were: SMA = 76.1 (47.1-107), E3 = 6.75 (0.0-25.9), SMA/E3 = 107 (78.0-132), and E3/SMA= 19.6 (6.99-42.4). All 4 variables were significantly different ( P adhesive combination of SMA/E3 had the highest adhesion, followed, in order, by SMA alone, E3/ SMA, and E3 alone. Both E3 groups left a difficult-to-remove residue on the skin. SMA/E3 left a halo-like residue on the skin at the periphery of the strips from the E3 leaking around the SMA. SMA remained adherent to the prosthetic material.

  15. [Technical complications rates and plaque control of fixed dental prostheses in patients treated for periodontal disease].

    Science.gov (United States)

    Xie, Yesi; Meng, Huanxin; Han, Jie; Pan, Shaoxia; Zhang, Li; Shi, Dong

    2016-02-01

    To compare the incidence of technical complications of implant-supported fixed dental prostheses in Chinese patients with a history of moderate or severe periodontitis and periodontally healthy patients(PHP) and analyze the effects of interproximal papillae patterns on food impaction and efficacy of plaque control. A total of 103 partially edentulous patients treated with implant-supported fixed dental prostheses between December 2009 and December 2012 for a minimum 1-year follow-up period were recruited from Department of Periodontology, Peking University, School and Hospital of Stomatology. Based on the initial periodontal examination, the participants were divided into three groups: 30 PHP, 36 moderate periodontally compromised patients(mPCP) and 37 severe periodontally compromised patients(sPCP). Implant survival/loss, technical complications, plaque index, papilla index, food impaction and degree of proximal contact tightness of each patient were assessed around the implants at follow-up. According to the implant papilla index, the implants were divided into two groups: the "filling" group with the mesial and distal aspects with papilla index=3 and the "no filling" group with at least one aspect with papilla indeximplant survival, technical complications were analyzed. Comparisons of the incidence of technical complications were performed between the patients with different periodontal conditions with chi-square or Fisher's exact test. The influences of the interproximal papillae loss on food impaction and efficacy of plaque control were estimated with chi-square and Mann-Whitney U tests. The total implant survival rate was 100%(162/162) for all three groups. Technical complications were as following: veneer fractures(1.9%, 3/162), abutment screw loosening(1.9%, 3/162), prosthetic screw loosening(3.1%, 5/162) and decementation(3.1%, 5/162) in all subjects. No implant/screw fracture was noted. The incidence of technical complications in sPCP, mPCP and PHP did

  16. Visual Culture and Visual Literacy

    Directory of Open Access Journals (Sweden)

    Sibel Onursoy

    2017-03-01

    Full Text Available Recently visual literacy gains importance in the context of understanding the rising visual culture products, thinking about them and producing these products. The purpose of this article examines the concept of visual literacy that is the relationship with visual culture depending on the literature. Visual literacy is one of the multiple literatures that emerge from the development of information and information dissemination forms. Visual literacy is an interdisciplinary concept and associated with some areas, such as graphic design, visual arts, architectural engineering, industrial product design, visual communication and media literacy. Visual culture covers every human product, so visual products that we face in everyday life and visual realities with abundant alternatives constitute our daily life itself. Sometimes, this confusing visual understanding creates a gap between contemporary cultural richness and what can be observed.

  17. Differences in performance of five types of aortic valve prostheses: haemodynamic assessment by dobutamine stress echocardiography.

    Science.gov (United States)

    Khoo, Jeffrey P; Davies, Joan E; Ang, Keng Leong; Galiñanes, Manuel; Chin, Derek T

    2013-01-01

    In patients being considered for aortic valve replacement, there remains controversy over which design or tissue offers the best performance. We aimed to evaluate in a single study the haemodynamic performances of five different widely used aortic valve prostheses: stentless porcine xenograft (Elan), stentless bovine pericardium (Pericarbon Freedom), stented porcine xenograft (Aspire), stented bovine pericardium (More) and mechanical (Ultracor). We also compared them with normal aortic valves and stenosed valves of variable severity. Preoperative echocardiography and dobutamine stress echocardiography at 1 year postoperatively were undertaken in 106 patients (n=18-24 from each group). Stentless bioprostheses, whether porcine or bovine, displayed superior haemodynamics across nearly all echocardiographic parameters: lower gradients, larger effective orifice area, higher dimensionless severity index (DSI) and lower resistance, when compared with stented or mechanical prostheses. Comparing both stented designs, bovine tissue performed the worst at rest, but with stress, there was no difference. The stress performances of the stentless bioprostheses were similar to the mildly stenosed native aortic valve, whereas the performances of the stented and mechanical prostheses resembled that of native valves with mild-to-moderate stenoses. Haemodynamic differences, however, did not translate into differences in left ventricular mass reduction at 1 year. Stentless bioprostheses displayed haemodynamics superior to stented or mechanical prostheses and had the closest performance to a normal, native aortic valve. Stress DSI data, least reliant on variable annulus/valve sizes and flow rates, provided the best haemodynamic discrimination.

  18. [Aftercare for durability and profitability of single-unit and multi-unit fixed dental prostheses

    NARCIS (Netherlands)

    Baat, C. de; Loveren, C. van; Maarel-Wierink, C.D. van der; Witter, D.J.; Creugers, N.H.J.

    2013-01-01

    An important aim ofa treatment with single-unit and multi-unit fixed dental prostheses is a durable and profitable treatment outcome. That requires aftercare, too. First, the frequency of routine oral examinations should be assessed, using an individual risk profile. The objectives of the routine

  19. Clinical Fit of Partial Removable Dental Prostheses Based on Alginate or Polyvinyl Siloxane Impressions.

    NARCIS (Netherlands)

    Fokkinga, W.A.; Witter, D.J.; Bronkhorst, E.M.; Creugers, N.H.J.

    2017-01-01

    PURPOSE: The aim of this study was to analyze the clinical fit of metal-frame partial removable dental prostheses (PRDPs) based on custom trays used with alginate or polyvinyl siloxane impression material. MATERIALS AND METHODS: Fifth-year students of the Nijmegen Dental School made 25 correct

  20. Fate of implant-retained craniofacial prostheses : Life span and aftercare

    NARCIS (Netherlands)

    Visser, Anita; Raghoebar, Gerry M.; van Oort, Robert P.; Vissink, Arjan

    2008-01-01

    Purpose: To assess the need for surgical and prosthetic aftercare of craniofacial prostheses supported by endosseous implants. Materials and Methods: A retrospective clinical study assessing the surgical and prosthetic aftercare from implant placement to last visit of follow-up was performed in

  1. Stemmed femoral knee prostheses: effects of prosthetic design and fixation on bone loss.

    NARCIS (Netherlands)

    Lenthe, G.H. van; Willems, P.C.P.H.; Verdonschot, N.J.J.; Waal Malefijt, M.C. de; Huiskes, R.

    2002-01-01

    Although the revision rates for modern knee prostheses have decreased drastically, the total number of revisions a year is increasing because many more primary knee replacements are being done. At the time of revision, bone loss is common, which compromises prosthetic stability. To improve

  2. Temporary cosmetic painted prostheses in anophthalmic surgery: an alternative to early postoperative clear conformers.

    Science.gov (United States)

    Avisar, I; Norris, J H; Quinn, S; Allan, D; McCalla, M; Dugdale, D; Parulekar, M; Malhotra, R

    2011-11-01

    To evaluate the use and safety of temporary, cosmetic, painted prostheses as an alternative to clear conformers immediately post removal of eye or socket surgery in children and adults. A 2-year, two-centre, retrospective audit of 54 patients undergoing enucleation, evisceration, secondary implant or socket reconstruction receiving a temporary painted prosthesis as an alternative to clear conformers immediately post surgery. Patient questionnaire and review of clinical notes was conducted for all patients. We reviewed 54 consecutive patients (22 females, 32 males, mean age 18.6 years, range 6 days to 82 years) who received cosmetic painted prostheses from January 2009 to December 2010. Procedures included: evisceration with primary implant (5), enucleation with primary implant (37), secondary implant (9), dermis fat graft (2) and fornix reconstruction with buccal graft (1). Complications included: pyogenic granuloma (2), mucous discharge (2) and exposure (2). All adults found their prosthesis comfortable, and no problems were reported by the parents of the children included in this study. In all, 46 patients (88% of respondents) returned to normal activities within 2 weeks. The temporary prosthesis fell out at least once in 25% of cases. In all, 90% of respondents expressed a definite preference towards the painted shell over a clear shell. Temporary cosmetic painted prostheses placed immediately after removal of the eye or socket surgery are well tolerated and preferred to standard clear shells. Painted prostheses, matched to the contralateral iris are a valuable option in anophthalmic surgery as an alternative to traditional clear conformers.

  3. HEALING OF MICROVENOUS PTFE PROSTHESES IMPLANTED INTO THE RAT FEMORAL VEIN

    NARCIS (Netherlands)

    VANDERLEI, B; DIJK, F; JONGEBLOED, WL; ROBINSON, PH; Bartels, H.

    44 PTFE prostheses (Gore-Tex(R); ID 1 mm) were implanted into rats' femoral veins by means of the sleeve anastomotic technique and were evaluated at regular intervals from 1 h up till 24 weeks after implantation by means of light and electron microscopy to study in detail their healing process. All

  4. The relative merits of cemented and uncemented prostheses in total hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Joanna Maggs

    2017-01-01

    Full Text Available The results of modern cemented and uncemented total hip arthroplasties are outstanding and both systems have their advantages and disadvantages. This paper aims to examine the designs of different types of prostheses, some history behind their development and the reported results. Particular emphasis is placed on cemented stem design and the details of cementing technique.

  5. [Loading and strength of single- and multi-unit fixed dental prostheses. 1. Retention and resistance

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Meijers, C.C.A.J.; Vergoossen, E.L.; Creugers, N.H.J.

    2014-01-01

    The degree to which single- and multi-unit fixed dental prostheses are able to withstand loading forces is dependent, among other things, on the quality of their retention and resistance. The quality of the retention and resistance of the configuration of an abutment tooth prepared for a metal and

  6. [Loading and strength of single- and multi-unit fixed dental prostheses 2. Strength

    NARCIS (Netherlands)

    Baat, C. de; Witter, D.J.; Meijers, C.C.A.J.; Vergoossen, E.L.; Creugers, N.H.J.

    2014-01-01

    The ultimate strength of a dental prosthesis is defined as the strongest loading force applied to the prosthesis until afracture failure occurs. Important key terms are strength, hardness, toughness and fatigue. Relatively prevalent complications of single- and multi-unit fixed dental prostheses are

  7. MODELING OF DENTAL PROSTHESES REMOVAL PROCESS BY MEANS OF VIBROIMPACT ULTRASONIC SYSTEM

    Directory of Open Access Journals (Sweden)

    M. G. Kiselev

    2007-01-01

    Full Text Available The results of experimental research on modeling dental prostheses removal process are given in the paper. It is determined on the basis of their analysis that the best conditions for detachment of prosthesis from a tooth body are provided in the case when a vibroiinpact mode of fracturing a cement layer used for crown fixation is realized.

  8. Evaluation of osseous integration of PVD-silver-coated hip prostheses in a canine model.

    Science.gov (United States)

    Hauschild, Gregor; Hardes, Jendrik; Gosheger, Georg; Stoeppeler, Sandra; Ahrens, Helmut; Blaske, Franziska; Wehe, Christoph; Karst, Uwe; Höll, Steffen

    2015-01-01

    Infection associated with biomaterials used for orthopedic prostheses remains a serious complication in orthopedics, especially tumor surgery. Silver-coating of orthopedic (mega)prostheses proved its efficiency in reducing infections but has been limited to surface areas exposed to soft tissues due to concerns of silver inhibiting osseous integration of cementless stems. To close this gap in the bactericidal capacity of silver-coated orthopedic prostheses extension of the silver-coating on surface areas intended for osseous integration seems to be inevitable. Our study reports about a PVD- (physical-vapor-deposition-) silver-coated cementless stem in a canine model for the first time and showed osseous integration of a silver-coated titanium surface in vivo. Radiological, histological, and biomechanical analysis revealed a stable osseous integration of four of nine stems implanted. Silver trace elemental concentrations in serum did not exceed 1.82 parts per billion (ppb) and can be considered as nontoxic. Changes in liver and kidney functions associated with the silver-coating could be excluded by blood chemistry analysis. This was in accordance with very limited metal displacement from coated surfaces observed by laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) 12 months after implantation. In conclusion our results represent a step towards complete bactericidal silver-coating of orthopedic prostheses.

  9. [Technical aspects of treatments with single- and multi-unit fixed dental prostheses

    NARCIS (Netherlands)

    Wiersema, E.J.; Kreulen, C.M.; Latzke, P.; Witter, D.J.; Creugers, N.H.J.

    2014-01-01

    For the manufacture of single- and multi-unit fixed dental prostheses, effective communication between dentist and dental technician is required. Mutual insight concerning the (im)possibilities of available treatments and technical options is prerequisitefor this communication. The manufacture of

  10. In vitro evaluation of failure loads of nonmetal cantilevered resin-bonded fixed dental prostheses

    NARCIS (Netherlands)

    van Dalen, A.; Feilzer, A.J.; Kleverlaan, C.J.

    2008-01-01

    Purpose: To evaluate in vitro the influence of fiber reinforcement on the failure loads of resin composite beams, simulating cantilevered two-unit resin-bonded fixed dental prostheses, and compare the results with similarly obtained failure loads of ZrO2 and CoCr beams of a comparable design.

  11. Grasping force and slip feedback through vibrotactile stimulation to be used in myoelectric forearm prostheses

    NARCIS (Netherlands)

    Muijzer-Witteveen, Heintje Johanna Berendina; Rietman, Johan Swanik; Veltink, Petrus H.

    User feedback about grasping force or slip of objects is lacking in current myoelectric forearm prostheses, resulting in a high number of prosthesis abandonment, because a high level of concentration is required to hold an object. Several approaches to provide force feedback to the user via

  12. Waterjet cutting of periprosthetic interface tissue in loosened hip prostheses: an in vitro feasibility study

    NARCIS (Netherlands)

    Kraaij, Gert; Tuijthof, Gabrielle J. M.; Dankelman, Jenny; Nelissen, Rob G. H. H.; Valstar, Edward R.

    2015-01-01

    Waterjet cutting technology is considered a promising technology to be used for minimally invasive removal of interface tissue surrounding aseptically loose hip prostheses. The goal of this study was to investigate the feasibility of waterjet cutting of interface tissue membrane. Waterjets with 0.2

  13. Achieving immediate function with provisional prostheses after implant placement: a clinical report.

    Science.gov (United States)

    Kwon, Kung-Rock; Sachdeo, Amit; Weber, Hans-Peter

    2005-06-01

    When using a conventional implant treatment protocol in edentulous patients, reduced function and comfort for up to 6 months after implant surgery is inevitable until bone healing is complete and a prosthesis is securely attached to the implants. The following report highlights 2 treatment modalities that enable immediate function by inserting provisional prostheses immediately after implant placement.

  14. The essential oil of Allium sativum as an alternative agent against Candida isolated from dental prostheses.

    Science.gov (United States)

    Mendoza-Juache, Alejandro; Aranda-Romo, Saray; Bermeo-Escalona, Josué R; Gómez-Hernández, Araceli; Pozos-Guillén, Amaury; Sánchez-Vargas, Luis Octavio

    The colonization of the surfaces of dental prostheses by Candida albicans is associated with the development of denture stomatitis. In this context, the use of fluconazole has been proposed, but its disadvantage is microbial resistance. Meanwhile, the oil of Allium sativum has shown an effect in controlling biofilm formation by C. albicans. The objective of this study was to determine the antifungal activities of the essential oil of A. sativum and fluconazole against clinical isolates of Candida species obtained from rigid, acrylic-based partial or total dentures and to compare these agents' effects on both biofilm and planktonic cells. A total of 48 clinical isolates obtained from the acrylic surface of partial or complete dentures were examined, and the following species were identified: C. albicans, Candida glabrata, Candida tropicalis, and Candida krusei. For each isolate, the antifungal activities of the essential oil of A. sativum and fluconazole against both biofilm and planktonic cells were evaluated using the Clinical & Laboratory Standards Institute (CLSI) M27-A3 method. The isolates were also evaluated by semiquantitative XTT reduction. All planktonic Candida isolates were susceptible to the essential oil of A. sativum, whereas 4.2% were resistant to fluconazole. Regarding susceptibilities in biofilms, 43.8% of biofilms were resistant to A. sativum oil, and 91.7% were resistant to fluconazole. All planktonic cells of the different Candida species tested are susceptible to oil, and the majority are susceptible to fluconazole. Susceptibility decreases in biofilm cells, with increased resistance to fluconazole compared with A. sativum oil. The essential oil of A. sativum is thus active against clinical isolates of Candida species obtained from dentures, with effects on both biofilm and planktonic cells in vitro. Copyright © 2017 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Percutaneous osseointegrated prostheses for amputees: Limb compensation in a 12-month ovine model.

    Science.gov (United States)

    Shelton, Trevor J; Beck, J Peter; Bloebaum, Roy D; Bachus, Kent N

    2011-10-13

    Percutaneous osseointegrated prostheses are being investigated as an alternative strategy to attach prosthetic limbs to patients. Although the use of these implants has shown to be promising in clinical trials, the ability to maintain a skin seal around an osseointegrated implant interface is a major challenge to prevent superficial and deep periprosthetic infections. The specific aim of this study was to establish a translational load-bearing ovine model to assess postoperative limb compensation and gait symmetry following a percutaneous osseointegrated implant. We tested the following hypotheses: (1) the animals would return to pre-amputation limb loads within 12-months; (2) the animals would return to a symmetrical gait pattern (stride length and time in stance) within 12-months. The results demonstrated that one month following surgery, the sheep loaded their amputated limb to a mean value of nearly 80% of their pre-amputation loading condition; by 12-months, this mean had dropped to approximately 74%. There was no statistical differences between the symmetry of the amputated forelimb and the contralateral forelimb at any time point for the animals stride length or the time spent in the stance phase of their gait cycle. Thus, the data showed that while the animals maintained symmetric gait patterns, they did not return to full weight-bearing after 12-months. The results of this study showed that a large animal load-bearing model had a symmetric gait and was weight bearing for up to 12 months. While the current investigation utilizes an ovine model, the data show that osseointegrated implant technology with postoperative follow-up can help our human patients return to symmetric gait and maintain an active lifestyle, leading to an improvement in their quality of life following amputation. Published by Elsevier Ltd.

  16. Tooth-implant-supported posterior fixed dental prostheses with zirconia frameworks: 3-year clinical result.

    Science.gov (United States)

    Beuer, Florian; Sachs, Caroline; Groesser, Julian; Gueth, Jan-Frederik; Stimmelmayr, Michael

    2016-06-01

    This case series compared the clinical survival of tooth-implant-supported (TI-S) and tooth-supported (T-S) three-unit fixed dental prostheses (FDPs) with zirconia frameworks and described the incidence of biological and technical complications. Forty-four patients received 27 TI-S FDPs and 22 T-S FDPs. Twenty-seven titanium screw implants were inserted at the dislodged position of two missing posterior teeth. All implants were provided with customized zirconia abutments. Zirconia frameworks were fabricated by a CAD/CAM system and veneered in powder build-up technique. All restorations were cemented with glass ionomer. Baseline evaluation was performed 2 weeks after cementation with recall examinations performed at 6, 12, 24 and 36 months by calibrated investigators. Survival probabilities according to Kaplan-Meier were calculated. Gingival parameters and bone loss were assessed and statistically evaluated. The mean service time of the FDPs was 35 months (±6). Two technical complications (fracture of veneering porcelain) were observed. One biological complication was recorded. The Kaplan-Meier survival probability was 93.9 % for all types of complications and 100 % related to restorations in service. The type of abutment support (TI-S vs. T-S) had no significant influence on the survival probability (p = 0.412, log rank test). No difference of the gingival parameters was detected between implants and natural teeth. Tooth-implant-supported zirconia-based FDPs showed similar clinical performance compared to tooth-supported zirconia-based FDPs. Within the limitations of this case series, tooth-implant-supported FDPs with zirconia frameworks seem to be a reliable treatment option.

  17. Influence of the veneering process on the marginal fit of zirconia fixed dental prostheses.

    Science.gov (United States)

    Kohorst, P; Brinkmann, H; Dittmer, M P; Borchers, L; Stiesch, M

    2010-04-01

    Distortions in the marginal region during manufacture are detrimental to the long-term success of fixed dental prostheses (FDPs). The aim of the present in vitro study was to evaluate changes in marginal fit because of the veneering process of four-unit FDPs made from different zirconia materials. Two groups of FDPs with 10 specimens each were machined from white body zirconia blanks (VITA In-Ceram YZ Cubes, KaVo Everest ZS-Blanks) by means of computer-aided design/computer-aided manufacturing systems and subsequently sintered to their final density. The marginal and internal gaps of the frameworks were determined using a replica technique. Afterwards, frameworks were veneered with the recommended ceramics (VITA VM9, GC Initial Zr), and fitting accuracy was evaluated again. Statistical analyses were performed by Student's t-test with the level of significance chosen at 0.05. With one framework/veneering system (Everest ZS-Blanks/Initial Zr), both marginal gap (P = 0.019) and internal gap (P = 0.001) at the premolar retainer were significantly affected by the veneering process. The resulting distortions were directed towards the lumina of the retainers and the mean values of the measured gaps decreased by about 23.8 mum (marginal gap) and 27.3 mum (internal gap). For the other system (In-Ceram YZ Cubes/VM9), no distortions because of the veneering were found. The veneering of zirconia restorations may lead to significant changes in the marginal fit, while the combination of core and veneering material used influences the resulting distortions.

  18. Investigation of Timing to Switch Control Mode in Powered Knee Prostheses during Task Transitions.

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    Full Text Available Current powered prosthetic legs require switching control modes according to the task the user is performing (e.g. level-ground walking, stair climbing, walking on slopes, etc.. To allow prosthesis users safely and seamlessly transition between tasks, it is critical to determine when to switch the prosthesis control mode during task transitions. Our previous study defined critical timings for different types of task transitions in ambulation; however, it is unknown whether it is the unique timing that allows safe and seamless transitions. The goals of this study were to (1 systematically investigate the effects of mode switch timing on the prosthesis user's performance in task transitions, and (2 identify appropriate timing to switch the prosthesis control mode so that the users can seamlessly transition between different locomotion tasks. Five able-bodied (AB and two transfemoral (TF amputee subjects were tested as they wore a powered knee prosthesis. The prosthesis control mode was switched manually at various times while the subjects performed different types of task transitions. The subjects' task transition performances were evaluated by their walking balance and success in performing seamless task transitions. The results demonstrated that there existed a time window within which switching the prosthesis control mode neither interrupted the subjects' task transitions nor disturbed their walking balance. Therefore, the results suggested the control mode switching of a lower limb prosthesis can be triggered within an appropriate time window instead of a specific timing or an individual phase. In addition, a generalized criterion to determine the appropriate mode switch timing was proposed. The outcomes of this study could provide important guidance for future designs of neurally controlled powered knee prostheses that are safe and reliable to use.

  19. The influence of early speech rehabilitation with voice prostheses on the psychological state of laryngectomized patients.

    Science.gov (United States)

    de Maddalena, Harry

    2002-01-01

    This survey assessed how early speech rehabilitation influences the emotional state and psychological adjustment of 43 male laryngectomy patients, at three different chronological stages. The first assessment occurred 2-3 days before the operation. The patients filled out a stress questionnaire (SVF) which assessed coping strategies. Exactly 2 weeks after the operation the patients were given a list of adjectives (EWL) which measured their actual emotional state. One day before leaving the hospital the patients were given the Post-laryngectomy Telephone Test (PLTT) which ascertained the quality of speech intelligibility. In addition, patients filled out a questionnaire on postoperative stress and anticipated stigmatisation with regard to their changed voice. Results demonstrated that patients who had early speech rehabilitation felt significantly more active and, in general, felt considerably better than patients who had not received speech rehabilitation training. Patients assessed voice loss as extremely distressing. The postoperative stress and the anticipated stigmatisation on the basis of the changed voice was significantly higher in those patients with good speech intelligibility than in patients with poor speech articulation at hospital discharge. The coping strategies "Giving up and resignation" and "Need for social support" correlated positively with postoperative stress and anticipated stigmatisation. Results show that early speech rehabilitation with voice prostheses had a positive effect on the emotional state of laryngectomy patients. However, the early speech rehabilitation leads to distress in the initial phase in laryngectomy patients. Moreover, patients who habitually tend towards resignation, or need lots of social support should receive psychological support during the early phase of speech rehabilitation training.

  20. Issues in the Educational, Psychological Assessment of Visually Impaired Children: Test-Retest Reliability of the Williams Intelligence Test for Children with Defective Vision

    Science.gov (United States)

    Tobin, Michael J.; Hill, Eileen W.

    2011-01-01

    The article discusses some problems confronting teachers and psychologists when making decisions as to how to use the currently available test procedures. It reports data gathered on three separate occasions on the performance of a group of blind and partially sighted children on the Williams Intelligence Test which is the only specialist IQ test…

  1. Performance of an Optimized Paper-Based Test for Rapid Visual Measurement of Alanine Aminotransferase (ALT in Fingerstick and Venipuncture Samples.

    Directory of Open Access Journals (Sweden)

    Sidhartha Jain

    Full Text Available A paper-based, multiplexed, microfluidic assay has been developed to visually measure alanine aminotransferase (ALT in a fingerstick sample, generating rapid, semi-quantitative results. Prior studies indicated a need for improved accuracy; the device was subsequently optimized using an FDA-approved automated platform (Abaxis Piccolo Xpress as a comparator. Here, we evaluated the performance of the optimized paper test for measurement of ALT in fingerstick blood and serum, as compared to Abaxis and Roche/Hitachi platforms. To evaluate feasibility of remote results interpretation, we also compared reading cell phone camera images of completed tests to reading the device in real time.96 ambulatory patients with varied baseline ALT concentration underwent fingerstick testing using the paper device; cell phone images of completed devices were taken and texted to a blinded off-site reader. Venipuncture serum was obtained from 93/96 participants for routine clinical testing (Roche/Hitachi; subsequently, 88/93 serum samples were captured and applied to paper and Abaxis platforms. Paper test and reference standard results were compared by Bland-Altman analysis.For serum, there was excellent agreement between paper test and Abaxis results, with negligible bias (+4.5 U/L. Abaxis results were systematically 8.6% lower than Roche/Hitachi results. ALT values in fingerstick samples tested on paper were systematically lower than values in paired serum tested on paper (bias -23.6 U/L or Abaxis (bias -18.4 U/L; a correction factor was developed for the paper device to match fingerstick blood to serum. Visual reads of cell phone images closely matched reads made in real time (bias +5.5 U/L.The paper ALT test is highly accurate for serum testing, matching the reference method against which it was optimized better than the reference methods matched each other. A systematic difference exists between ALT values in fingerstick and paired serum samples, and can be

  2. Performance of an Optimized Paper-Based Test for Rapid Visual Measurement of Alanine Aminotransferase (ALT) in Fingerstick and Venipuncture Samples.

    Science.gov (United States)

    Jain, Sidhartha; Rajasingham, Radha; Noubary, Farzad; Coonahan, Erin; Schoeplein, Ryan; Baden, Rachel; Curry, Michael; Afdhal, Nezam; Kumar, Shailendra; Pollock, Nira R

    2015-01-01

    A paper-based, multiplexed, microfluidic assay has been developed to visually measure alanine aminotransferase (ALT) in a fingerstick sample, generating rapid, semi-quantitative results. Prior studies indicated a need for improved accuracy; the device was subsequently optimized using an FDA-approved automated platform (Abaxis Piccolo Xpress) as a comparator. Here, we evaluated the performance of the optimized paper test for measurement of ALT in fingerstick blood and serum, as compared to Abaxis and Roche/Hitachi platforms. To evaluate feasibility of remote results interpretation, we also compared reading cell phone camera images of completed tests to reading the device in real time. 96 ambulatory patients with varied baseline ALT concentration underwent fingerstick testing using the paper device; cell phone images of completed devices were taken and texted to a blinded off-site reader. Venipuncture serum was obtained from 93/96 participants for routine clinical testing (Roche/Hitachi); subsequently, 88/93 serum samples were captured and applied to paper and Abaxis platforms. Paper test and reference standard results were compared by Bland-Altman analysis. For serum, there was excellent agreement between paper test and Abaxis results, with negligible bias (+4.5 U/L). Abaxis results were systematically 8.6% lower than Roche/Hitachi results. ALT values in fingerstick samples tested on paper were systematically lower than values in paired serum tested on paper (bias -23.6 U/L) or Abaxis (bias -18.4 U/L); a correction factor was developed for the paper device to match fingerstick blood to serum. Visual reads of cell phone images closely matched reads made in real time (bias +5.5 U/L). The paper ALT test is highly accurate for serum testing, matching the reference method against which it was optimized better than the reference methods matched each other. A systematic difference exists between ALT values in fingerstick and paired serum samples, and can be addressed by

  3. Clinical and patient-reported outcomes of zirconia-based implant fixed dental prostheses: Results of a prospective case series 5 years after implant placement.

    Science.gov (United States)

    Spies, Benedikt Christopher; Witkowski, Siegbert; Vach, Kirstin; Kohal, Ralf-Joachim

    2018-01-01

    To evaluate the clinical and patient-reported outcome of all-ceramic zirconia implant supported fixed dental prostheses (FDPs) 5 years after implant installation. Thirteen patients were treated with two terminally placed one-piece zirconia implants for a three-unit FDP each. The FDPs consisted of a CAD/CAM-fabricated zirconia framework over-pressed with a fluor-apatite veneering ceramic and were adhesively cemented. Survival and success were assessed by applying modified US Public Health Service (USPHS) criteria and preparation of Kaplan-Meier (KM) plots. Alpha and Bravo ratings were accepted for success (among others including small area veneer chippings and occlusal roughness), whereas Charlie ratings allowing for intra-oral correction (e.g., polishing) were accepted for survival. Furthermore, patient-reported outcome measures (PROMs) were analyzed with the help of visual analogue scales (VAS). Wilcoxon matched-pairs signed-rank test (USPHS criteria) and linear mixed models (PROMs) were used to evaluate time effects on response variables. All patients were available 61.8 ± 1.1 months after implant installation (53.6 ± 3.1 months after final prosthesis insertion). FDP survival was 100%. Significant incidence of veneer chipping (p = .0096) and occlusal roughness (p = .0019) was observed. Charlie rated extent of both phenomena resulted in a KM success estimate of 38.5% (95% CI: 14.1%-62.8%; seven FDPs with obvious roughness, three of them with extended veneer chipping). Compared with the pre-treatment assessments (30%-81% of satisfaction), all surveys at prosthetic delivery showed significantly improved VAS scores (66%-93%; p ≤ .038), except for speech (p = .341). Concerning function, esthetics and self-esteem, no decrease in satisfaction could be observed until the end of follow-up (90%-96%; p ≥ .057), whereas perception of sense (92%) and speech (95%) increased over time (p ≤ .030). Occurrence of technical complications did not correlate

  4. Convergent validity of the measures of attention and impulsivity in the Trees: simple Visual Discrimination Test (DiViSA-UAM

    Directory of Open Access Journals (Sweden)

    José H. Lozano

    2015-01-01

    Full Text Available The Trees: Simple Visual Discrimination Test (DiViSA-UAM is an objective test to assess attention and impulsivity in children aged between 6 and 12 years. The aim of this study was to supplement the validity data obtained in prior research, analyzing the evidence of convergent validity of the measures of the DiViSA-UAM in relation to other, already well-established, instruments for assessing attention and inhibitory control in children: the 'Faces', Differences Perception Test and the d2 Test of Attention. To this end, the instruments were administered to a sample of 111 students from primary education (46 girls and 65 boys between the ages of 8 and 12 years. The correlation analysis showed values in line with expectations among the indices of the three tests. Similarly to what has been observed in prior research, the three tests coincided in identifying a progressive increase in attention performance between the ages of 8 and 12, as well as stability in impulsivity control and the absence of sex-related differences. We discuss the potential advantages of the DiViSA-UAM derived from its application format and its greater ease of execution.

  5. Prevention of biofilm formation by dairy products and N-acetylcysteine on voice prostheses in an artificial throat.

    Science.gov (United States)

    Schwandt, Leonora Q; Van Weissenbruch, Ranny; Stokroos, Ietse; Van der Mei, Henny C; Busscher, Henk J; Albers, Frans W J

    2004-08-01

    To evaluate the preventive effect of buttermilk, Yakult Light fermented milk drink and N-acetylcysteine on biofilm formation on voice prostheses in vitro. Groningen button and Provox 2 voice prostheses were inoculated with a mixture of bacteria and yeasts isolated from previously explanted Groningen button voice prostheses. After 5 h, separate throats were flushed with buttermilk, Yakult Light fermented milk drink, N-acetylcysteine or phosphate-buffered saline, which served as a control. After 7 days, the microflora on each voice prosthesis was determined. On Groningen button voice prostheses, buttermilk, Yakult Light fermented milk drink and N-acetylcysteine all reduced the amount of both bacteria and yeasts. On Provox 2 voice prostheses, buttermilk, Yakult Light fermented milk drink and N-acetylcysteine reduced the amount of bacteria but, conversely, increased the amount of yeasts. These in vitro experiments demonstrate that biofilm formation on voice prostheses is reduced in an artificial throat by the use of buttermilk, Yakult Light fermented milk drink and N-acetylcysteine. However, the structural differences between the type of voice prostheses may influence the ultimate effects.

  6. Developmental Test of Visual-Motor Integration (VMI): An Effective Outcome Measure for Handwriting Interventions for Kindergarten, First-Grade, and Second-Grade Students?

    Science.gov (United States)

    Pfeiffer, Beth; Moskowitz, Beverly; Paoletti, Andrew; Brusilovskiy, Eugene; Zylstra, Sheryl Eckberg; Murray, Tammy

    2015-01-01

    We determined whether a widely used assessment of visual-motor skills, the Beery-Buktenica Developmental Test of Visual-Motor Integration (VMI), is appropriate for use as an outcome measure for handwriting interventions. A two-group pretest-posttest design was used with 207 kindergarten, first-grade, and second-grade students. Two well-established handwriting measures and the VMI were administered pre- and postintervention. The intervention group participated in the Size Matters Handwriting Program for 40 sessions, and the control group received standard instruction. Paired and independent-samples t tests were used to analyze group differences. The intervention group demonstrated significant improvements on the handwriting measures, with change scores having mostly large effect sizes. We found no significant difference in change scores on the VMI, t(202)=1.19, p=.23. Results of this study suggest that the VMI may not detect changes in handwriting related to occupational therapy intervention. Copyright © 2015 by the American Occupational Therapy Association, Inc.

  7. High variability of the subjective visual vertical test of vertical perception, in some people with neck pain - Should this be a standard measure of cervical proprioception?

    Science.gov (United States)

    Treleaven, Julia; Takasaki, Hiroshi

    2015-02-01

    Subjective visual vertical (SVV) assesses visual dependence for spacial orientation, via vertical perception testing. Using the computerized rod-and-frame test (CRFT), SVV is thought to be an important measure of cervical proprioception and might be greater in those with whiplash associated disorder (WAD), but to date research findings are inconsistent. The aim of this study was to investigate the most sensitive SVV error measurement to detect group differences between no neck pain control, idiopathic neck pain (INP) and WAD subjects. Cross sectional study. Neck Disability Index (NDI), Dizziness Handicap Inventory short form (DHIsf) and the average constant error (CE), absolute error (AE), root mean square error (RMSE), and variable error (VE) of the SVV were obtained from 142 subjects (48 asymptomatic, 36 INP, 42 WAD). The INP group had significantly (p proprioception in neck pain and more research is required before the SVV can be considered an important measure and utilized clinically. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  8. Poor visualization during direct laryngoscopy and high upper lip bite test score are predictors of difficult intubation with the GlideScope videolaryngoscope.

    Science.gov (United States)

    Tremblay, Marie-Hélène; Williams, Stephan; Robitaille, Arnaud; Drolet, Pierre

    2008-05-01

    The GlideScope videolaryngoscope allows equal or superior glottic visualization compared with direct laryngoscopy, but predictive features for difficult GlideScope intubation have not been identified. We undertook this prospective study to identify patient characteristics associated with difficult GlideScope intubation. Demographic and morphometric factors were recorded preoperatively for 400 patients undergoing anesthesia with endotracheal intubation. After induction, direct laryngoscopy was performed in all patients to assess the Cormack and Lehane grade of glottic visualization followed by GlideScope intubation. The number of attempts and time needed for intubation were recorded. Univariate and multivariate analyses were performed to identify the characteristics associated with difficult GlideScope intubation. Intubation required 1, 2, and 3 attempts in 342, 48, and 9 participants, respectively, with one failure. Mean time for intubation was 21 +/- 14 s. After univariate analysis, the following characteristics were significantly correlated (P Cormack and Lehane grade during direct laryngoscopy. However, after introducing these variables in nominal logistic and proportional hazard multiple regression models, only high Cormack and Lehane grade during direct laryngoscopy, high upper lip bite test score, and short sternothyroid distance were significantly associated with multiple attempts or lengthier intubations. Despite a high success rate, intubation with the GlideScope is likely to be more challenging in patients with high Cormack and Lehane grade during direct laryngoscopy, high upper lip bite test score, or short sternothyroid distance.

  9. [Evaluation of preclinical onset in patients with the childhood form of cerebral adrenoleukodystrophy--usefulness of visual cognitive function and evoked potential tests].

    Science.gov (United States)

    Furushima, Wakana; Inagaki, Masumi; Gunji, Atsuko; Kaga, Makiko; Yamazaki, Hiroko; Horiguchi, Toshihiro

    2008-07-01

    We examined both visual evoked potential (VEP) and neuropsychological tests in 18 patients with X-linked adrenoleukodystrophy (ALD). Patients consisted of 10 boys with apparent lesions in the posterior white matter on MR imaging, 3 with lesions in the frontal white matter area and 5 that were neurologically asymptomatic with no apparent brain MRI abnormalities. Almost all patients with posterior WM lesion showed patterns of lower PIQ than VIQ on WISC-III and lower scores on scales for simultaneous processing than for sequential processing on Kaufman Assesment Battery for Children (K-ABC). Four of 5 asymptomatic patients showed PIQ/VIQ patterns similar to those in the posterior group. Patients with a difference more than 13 between PIQ and VIQ also showed poor results on Frostig developmental test of visual perception (DTVP). There was a prolongation of the peak latency of P100 on flash VEP in many patients with posterior whitematter lesions, however, asymptomatic patients did not show any abnormality of P100 latency but there was an increased amplitude of N75-P100 on flash and pattern reversal stimuli VEP. One patient with abnormally high VEP (31.4 microV; + 3.6 SD) gradually improved to the normal range (11.4 microV; 0SD) after hematopoietic stem cell transplantation. These cognitive and neurophysiological examinations could be useful in the detection of preclinical onset of childhood ALD before the appearance of MRI lesions on MRI.

  10. Performance of visual inspection with acetic acid and human papillomavirus testing for detection of high-grade cervical lesions in HIV positive and HIV negative Tanzanian women

    DEFF Research Database (Denmark)

    Dartell, Myassa Arkam; Rasch, Vibeke; Iftner, Thomas

    2014-01-01

    The aim of this cross sectional study was to assess type distribution of human papillomavirus (HPV) among HIV positive and HIV negative women who underwent cervical cancer screening, and to examine the ability of visual inspection with acetic acid (VIA), the standard detection method in Tanzania,...... of establishing a screening program which also reaches HIV positive women. Our results highlight the importance of continuous training of staff performing VIA, and also point to the need for other screening methods such as HPV-testing at low cost.......-testing for detection of HSIL+. The sensitivity of VIA varied with staff VIA experience, HIV status and age. Vaccines including HPV16, HPV52 and HPV18 will likely reduce the number of HSIL+ cases independently of HIV status. The frequency of HSIL+ was high among HIV positive women, emphasizing the importance...

  11. Human Visual System as a Double-Slit Single Photon Interference Sensor: A Comparison between Modellistic and Biophysical Tests.

    Directory of Open Access Journals (Sweden)

    Rita Pizzi

    Full Text Available This paper describes a computational approach to the theoretical problems involved in the Young's single-photon double-slit experiment, focusing on a simulation of this experiment in the absence of measuring devices. Specifically, the human visual system is used in place of a photomultiplier or similar apparatus. Beginning with the assumption that the human eye perceives light in the presence of very few photons, we measure human eye performance as a sensor in a double-slit one-photon-at-a-time experimental setup. To interpret the results, we implement a simulation algorithm and compare its results with those of human subjects under identical experimental conditions. In order to evaluate the perceptive parameters exactly, which vary depending on the light conditions and on the subject's sensitivity, we first review the existing literature on the biophysics of the human eye in the presence of a dim light source, and then use the known values of the experimental variables to set the parameters of the computational simulation. The results of the simulation and their comparison with the experiment involving human subjects are reported and discussed. It is found that, while the computer simulation indicates that the human eye has the capacity to detect the corpuscular nature of photons under these conditions, this was not observed in practice. The possible reasons for the difference between theoretical prediction and experimental results are discussed.

  12. Test characteristics of visual inspection with 4% acetic acid (VIA) and Lugol's iodine (VILI) in cervical cancer screening in Kerala, India.

    Science.gov (United States)

    Sankaranarayanan, Rengaswamy; Wesley, Ramani; Thara, Somanathan; Dhakad, Namrata; Chandralekha, Bharathykutty; Sebastian, Paul; Chithrathara, K; Parkin, Donald Maxwell; Nair, Madhavan Krishnan

    2003-09-01

    Simple and inexpensive methods based on visual examination of the cervix are currently being investigated as alternative methods of cervical screening. The test characteristics of visual inspection with 4% acetic acid (VIA), and Lugol's iodine (VILI) and conventional cytology were investigated in a cross-sectional study involving 4,444 women aged 25 to 65 years in Kerala, India. While detection of any acetowhite area constituted a low-threshold positive VIA, detection of well-defined, opaque acetowhite lesions close to or touching the squamocolumnar junction constituted a high-threshold positive VIA test. Detection of definite yellow iodine nonuptake areas in the transformation zone close to or touching the squamocolumnar junction constituted a positive VILI test. Cytology was considered positive if reported as atypia or worse lesions. All screened women were evaluated by colposcopy and biopsies were directed in 1,644 women (37.0%), which allowed the direct estimation of sensitivity, specificity and predictive values. The reference diagnosis was based on a combination of histology and/or colposcopy. True disease status was defined as CIN 2 and worse lesions. A total of 149 (3.4%) women had CIN 2 or worse lesions. The sensitivities of low-threshold VIA, high-threshold VIA, VILI and cytology to detect CIN 2 or worse disease were 88.6%, 82.6%, 87.2% and 81.9%, respectively; the corresponding specificities were 78.0%, 86.5%, 84.7% and 87.8%. Our results indicate that VIA and VILI are suitable alternate screening tests to cytology for detecting cervical neoplasia in low-resource settings. Copyright 2003 Wiley-Liss, Inc.

  13. Visual art and visual perception

    NARCIS (Netherlands)

    Koenderink, Jan J.

    2015-01-01

    Visual art and visual perception ‘Visual art’ has become a minor cul-de-sac orthogonal to THE ART of the museum directors and billionaire collectors. THE ART is conceptual, instead of visual. Among its cherished items are the tins of artist’s shit (Piero Manzoni, 1961, Merda d’Artista) “worth their

  14. Using empirical Bayes predictors from generalized linear mixed models to test and visualize associations among longitudinal outcomes.

    Science.gov (United States)

    Mikulich-Gilbertson, Susan K; Wagner, Brandie D; Grunwald, Gary K; Riggs, Paula D; Zerbe, Gary O

    2018-01-01

    Medical research is often designed to investigate changes in a collection of response variables that are measured repeatedly on the same subjects. The multivariate generalized linear mixed model (MGLMM) can be used to evaluate random coefficient associations (e.g. simple correlations, partial regression coefficients) among outcomes that may be non-normal and differently distributed by specifying a multivariate normal distribution for their random effects and then evaluating the latent relationship between them. Empirical Bayes predictors are readily available for each subject from any mixed model and are observable and hence, plotable. Here, we evaluate whether second-stage association analyses of empirical Bayes predictors from a MGLMM, provide a good approximation and visual representation of these latent association analyses using medical examples and simulations. Additionally, we compare these results with association analyses of empirical Bayes predictors generated from separate mixed models for each outcome, a procedure that could circumvent computational problems that arise when the dimension of the joint covariance matrix of random effects is large and prohibits estimation of latent associations. As has been shown in other analytic contexts, the p-values for all second-stage coefficients that were determined by naively assuming normality of empirical Bayes predictors provide a good approximation to p-values determined via permutation analysis. Analyzing outcomes that are interrelated with separate models in the first stage and then associating the resulting empirical Bayes predictors in a second stage results in different mean and covariance parameter estimates from the maximum likelihood estimates generated by a MGLMM. The potential for erroneous inference from using results from these separate models increases as the magnitude of the association among the outcomes increases. Thus if computable, scatterplots of the conditionally independent empirical Bayes

  15. Screening for hearing and visual loss among elderly with questionnaires and tests : which method is the most convincing for action?

    NARCIS (Netherlands)

    Eekhof, JAH; De Bock, GH; Schaapveld, K; Springer, MP

    2000-01-01

    Objective - To examine the extent to which self-report and performance-based measures identify the same people, and also whether one of these methods any more than the other induces the general practitioner (GP) to offer a patient help? Design - Comparison of tests and questionnaire in a screening

  16. The eye-complaint questionnaire in a visual display unit work environment: Internal consistency and test-retest reliability

    NARCIS (Netherlands)

    Steenstra, Ivan A.; Sluiter, Judith K.; Frings-Dresen, Monique H. W.

    2009-01-01

    The internal consistency and test-retest reliability of a 10-item eye-complaint questionnaire (ECQ) were examined within a sample of office workers. Repeated within-subjects measures were performed within a single day and over intervals of 1 and 7 d. Questionnaires were completed by 96 workers (70%

  17. Effect of additional auditory and visual stimuli on continuous performance test (noise-generated CPT) in AD/HD children -- usefulness of noise-generated CPT.

    Science.gov (United States)

    Uno, Masaaki; Abe, Junko; Sawai, Chihiro; Sakaue, Yuhko; Nishitani, Atsushi; Yasuda, Yuriko; Tsuzuki, Kento; Takano, Tomoyuki; Ohno, Masaki; Maruyama, Tsuyoshi; Takeuchi, Yoshihiro

    2006-04-01

    The continuous performance test (CPT) is designed to measure sustained attention quantitatively. Several CPTs are used clinically. We have made changes to the conventional type of visual CPT, by displaying auditory and visual noise along with target or non-target stimuli. By influencing the recognition of the subjects in this way, the changes were intended to increase the sensitivity of detection of inattention and impulsiveness, to make CPT more useful for diagnosis, and to examine the effect of noise on AD/HD children during CPT performance. Its usefulness for AD/HD diagnosis and the reaction of AD/HD children to noise were examined using newly developed computer software. Using this CPT analysis, a significant difference was observed in all measurements, except mean reaction time, between the control and AD/HD groups, showing that it was useful as a supplementary diagnostic method for AD/HD, and was more useful in the younger age group than in the older age group, as the same for conventional CPTs. As compared to no-noise sessions, commission and omission errors both increased significantly in auditory and visual noise sessions. Thus, analyzing the changes in measurements during noise sessions will improve the diagnosis of inattention and combined AD/HD subtypes. Furthermore, it was suggested that analysis of the effects of noise on AD/HD children will benefit their handling in an educational environment. Since omission errors were decreased in AD/HD children by noise during the CPT performance as compared to the control group, noise may induce attention in AD/HD children. The present study presents new findings on the responses to noise of AD/HD children during the CPT.

  18. Flow visualization

    CERN Document Server

    Merzkirch, Wolfgang

    1974-01-01

    Flow Visualization describes the most widely used methods for visualizing flows. Flow visualization evaluates certain properties of a flow field directly accessible to visual perception. Organized into five chapters, this book first presents the methods that create a visible flow pattern that could be investigated by visual inspection, such as simple dye and density-sensitive visualization methods. It then deals with the application of electron beams and streaming birefringence. Optical methods for compressible flows, hydraulic analogy, and high-speed photography are discussed in other cha

  19. Clinical Tests of Ultra-Low Vision Used to Evaluate Rudimentary Visual Perceptions Enabled by the BrainPort Vision Device.

    Science.gov (United States)

    Nau, Amy; Bach, Michael; Fisher, Christopher

    2013-01-01

    We evaluated whether existing ultra-low vision tests are suitable for measuring outcomes using sensory substitution. The BrainPort is a vision assist device coupling a live video feed with an electrotactile tongue display, allowing a user to gain information about their surroundings. We enrolled 30 adult subjects (age range 22-74) divided into two groups. Our blind group included 24 subjects ( n = 16 males and n = 8 females, average age 50) with light perception or worse vision. Our control group consisted of six subjects ( n = 3 males, n = 3 females, average age 43) with healthy ocular status. All subjects performed 11 computer-based psychophysical tests from three programs: Basic Assessment of Light Motion, Basic Assessment of Grating Acuity, and the Freiburg Vision Test as well as a modified Tangent Screen. Assessments were performed at baseline and again using the BrainPort after 15 hours of training. Most tests could be used with the BrainPort. Mean success scores increased for all of our tests except contrast sensitivity. Increases were statistically significant for tests of light perception (8.27 ± 3.95 SE), time resolution (61.4% ± 3.14 SE), light localization (44.57% ± 3.58 SE), grating orientation (70.27% ± 4.64 SE), and white Tumbling E on a black background (2.49 logMAR ± 0.39 SE). Motion tests were limited by BrainPort resolution. Tactile-based sensory substitution devices are amenable to psychophysical assessments of vision, even though traditional visual pathways are circumvented. This study is one of many that will need to be undertaken to achieve a common outcomes infrastructure for the field of artificial vision.

  20. Comparison of educationally handicapped students scores on the Revised Developmental Test of Visual-Motor Integration and Bender-Gestalt.

    Science.gov (United States)

    Breen, M J

    1982-06-01

    32 elementary-aged boys enrolled in a program for the emotionally disturbed were administered the Revised Beery and Bender-Gestalt. A significant correlation of .73 was found between Beery and Bender age-equivalent scores. A t test for correlated data indicated mean scores did not differ significantly from one another, but scores were quite varied. The implications of such variability are discussed.

  1. Testing visual short-term memory of pigeons (Columba livia) and a rhesus monkey (Macaca mulatta) with a location change detection task.

    Science.gov (United States)

    Leising, Kenneth J; Elmore, L Caitlin; Rivera, Jacquelyne J; Magnotti, John F; Katz, Jeffrey S; Wright, Anthony A

    2013-09-01

    Change detection is commonly used to assess capacity (number of objects) of human visual short-term memory (VSTM). Comparisons with the performance of non-human animals completing similar tasks have shown similarities and differences in object-based VSTM, which is only one aspect ("what") of memory. Another important aspect of memory, which has received less attention, is spatial short-term memory for "where" an object is in space. In this article, we show for the first time that a monkey and pigeons can be accurately trained to identify location changes, much as humans do, in change detection tasks similar to those used to test object capacity of VSTM. The subject's task was to identify (touch/peck) an item that changed location across a brief delay. Both the monkey and pigeons showed transfer to delays longer than the training delay, to greater and smaller distance changes than in training, and to novel colors. These results are the first to demonstrate location-change detection in any non-human species and encourage comparative investigations into the nature of spatial and visual short-term memory.

  2. Utility of the Bender Visual-Motor Gestalt Test-Second Edition in the assessment of attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Allen, Ryan A; Decker, Scott L

    2008-12-01

    This study examined the use of the Bender Visual-Motor Gestalt Test-Second Edition (BGT-II) with children diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD). Previous research has examined the relationship of ADHD and visual-motor functioning based on overall developmental scores or specific emotional indicators. Although several studies have examined the relationship of the previous edition of the BGT-II and ADHD symptoms, psychometric issues associated with the original edition limit the validity of the results. The current study examined the utility of the BGT-II in the assessment of behaviors associated with ADHD. A group of 62 subjects diagnosed with ADHD (M=11 yr., 5 mo.; 45 male, 17 female) was compared to a control group of 62 subjects randomly selected from the BGT-II standardization data (M=11 yr., 6 mo; 33 male, 29 female). Several hypotheses were made regarding how areas of deficit, e.g., self-regulation, planning, working memory, and motor control, were expected to manifest in BGT-II performance. With IQ controlled, subjects with ADHD performed more poorly on the BGT-II than subjects with no known disorders; however, the effect size was small (eta(p)=.07). Emotional indicators intended to assess symptoms of ADHD did not demonstrate diagnostic utility.

  3. A visual study of forced convection boiling. Part 2: Flow patterns and burnout for a round test section

    International Nuclear Information System (INIS)

    Kirby, G.J.; Staniforth, R.; Kinneir, J.H.

    1967-03-01

    The studies of boiling water at 25 p.s.i.a. reported here show the same flow patterns as in earlier tests in that the bubbles formed on the heater regained close to the heated surface to coalesce into large bubbles which eventually spanned the flow channel. Burnout tests were made and it was found there was a change of slope of the heat flux-subcooling curve. Further tests showed that this effect was due to a change in flow regime between burnout with much vapour present and burnout with just nucleate bubbles present. In the latter regime it was found that burnout is dependent only on the conditions local to the burnout point. Photography of the burnout region was practicable only when few bubbles were present but although pictures of the bubble over the burnout point were taken, no clear evidence on the mechanism of formation of the bubble could be gleaned. Some speculation on the cause of burnout in this regime is made in the light of these experiments. (author)

  4. The Use of Prostheses in Pelvic Reconstructive Surgery: Joy or Toy?

    Directory of Open Access Journals (Sweden)

    Ming-Ping Wu

    2008-06-01

    Full Text Available The high recurrence rate of pelvic organ prolapse (POP of up to 30% after pelvic reconstructive surgery makes a more refined surgery imperative, as well as the need for either biological or synthetic prostheses as adjuvant treatment. Patients with recurrence risks may benefit from the adjuvant treatment: (1 to substitute for the lack of supportive tissue; (2 to reinforce inadequate tissue; (3 to induce new supportive tissue; and (4 to consolidate and complement the insufficient surgical techniques. However, some debatable issues in use of the prosthetics remain. The use of prosthetics enables the simultaneous repair of all vaginal defects of POP and concomitant anti-incontinence surgery to be faster, easier and more precise. Nevertheless, great care should be devoted to the actual and theoretical short- and long-term risks, many of which have not been fully elucidated. Despite the lack of various ideal characteristics, the type I monofilament, macroporous polypropylene, has been suggested to have the lowest incidence of infection and erosion among the nonabsorbable prostheses. There is good evidence to support the use of nonabsorbable synthetic mesh for abdominal sacrocolpopexy, while the use of prostheses for repairing isolated anterior and posterior compartment defects remains controversial. There have been no long-term studies with sufficient patient numbers to prove whether synthetic or biological prostheses are superior during vaginal surgery. Tension-free vaginal mesh techniques with procedural kits are being adopted increasingly, despite the paucity of data. Although short-term follow-up studies have shown tension-free vaginal mesh to be a safe and effective technique to correct POP, anatomic and functional results of long-term follow-up studies, however, have not yet confirmed the effectiveness and safety. Mesh erosion remains a concern, with variable rates according to different materials and approaches. Newly developed prostheses offer

  5. Preliminary observations on influence of dairy products on biofilm removal from silicone rubber voice prostheses in vitro

    NARCIS (Netherlands)

    Busscher, HJ; Free, RH; Van Weissenbruch, R; Albers, FWJ; Van der Mei, HC

    We determined oropharyngeal biofilm removal from silicone rubber voice prostheses in an artificial throat after perfusion with different commercially available dairy products, including buttermilk, Lactobacillus casei Shirota fermented milk (Yakult, Yakult Netherlands BV, Almere, The Netherlands),

  6. Fitting a bilateral transhumeral amputee with utensil prostheses and their functional assessment 10 years later: a case report.

    Science.gov (United States)

    Hung, Jen Wen; Wu, Yee Hwa

    2005-11-01

    Traumatic transhumeral amputations resulting from electric burn injury are uncommon and present a significant rehabilitation challenge. Compensating for loss of fine, coordinated function of the upper extremities with prostheses is difficult medically, technologically, psychologically, and socially. We followed up a patient with traumatic bilateral transhumeral amputation who was fitted with specially designed bilateral low-temperature utensil prostheses for 10 years. A bilateral utensil prosthesis consists of 2 thermoplastic sockets, an elastic harness, 2 utensil holders, and several different utensils. The characteristics of utensil prostheses are low cost, quick fabrication, and responsiveness to a patient's needs. Ten years after the patient's first prosthesis fitting, he still used these specially designed prostheses. By using these devices and his feet, the patient has regained independence in most activities of daily living and gained a new working skill.

  7. Post-Retained Single Crowns versus Fixed Dental Prostheses: A 7-Year Prospective Clinical Study.

    Science.gov (United States)

    Ferrari, M; Sorrentino, R; Juloski, J; Grandini, S; Carrabba, M; Discepoli, N; Ferrari Cagidiaco, E

    2017-12-01

    Biomechanical integrity of endodontically treated teeth (ETT) is often compromised. Degree of hard tissue loss and type of final prosthetic restoration should be carefully considered when making a treatment plan. The objective of this prospective clinical trial was to assess the influence of the type of prosthetic restoration as well as the degree of hard tissue loss on 7-y clinical performance of ETT restored with fiber posts. Two groups ( n = 60) were defined depending on the type of prosthetic restoration needed: 1) single unit porcelain-fused-to-metal (PFM) crowns (SCs) and 2) 3- to 4-unit PFM fixed dental prostheses (FDPs), with 1 healthy and 1 endodontically treated and fiber post-restored abutment. Within each group, samples were divided into 2 subgroups ( n = 30) according to the amount of residual coronal tissues after abutment buildup and final preparation: A) >50% of coronal residual structure or B) equal to or <50% of coronal residual structure. The clinical outcome was assessed based on clinical and intraoral radiographic examinations at the recalls after 6, 12, 24, 36, 48, and 84 mo. Data were analyzed by Kaplan-Meier log-rank test and Cox regression analysis ( P < 0.05). The overall 7-y survival rate of ETT restored with fiber post and either SCs or FDPs was 69.2%. The highest 84-mo survival rate was recorded in group 1A (90%), whereas teeth in group 2B exhibited the lowest performance (56.7% survival rate). The log-rank test detected statistically significant differences in survival rates among the groups ( P = 0.048). Cox regression analysis revealed that the amount of residual coronal structure ( P = 0.041; hazard ratio [HR], 2.026; 95% confidence interval [CI] for HR, 1.031-3.982) and the interaction between the type of prosthetic restoration and the amount of residual coronal structure ( P = 0.024; HR, 1.372; 95% CI for HR, 1.042-1.806) were statistically significant factors for survival ( ClinicalTrials.gov NCT01532947).

  8. Flight Test Evaluation of an Unmanned Aircraft System Traffic Management (UTM) Concept for Multiple Beyond-Visual-Line-of-Sight Operations

    Science.gov (United States)

    Johnson, Marcus; Jung, Jaewoo; Rios, Joseph; Mercer, Joey; Homola, Jeffrey; Prevot, Thomas; Mulfinger, Daniel; Kopardekar, Parimal

    2017-01-01

    This study evaluates a traffic management concept designed to enable simultaneous operations of multiple small unmanned aircraft systems (UAS) in the national airspace system (NAS). A five-day flight-test activity is described that examined the feasibility of operating multiple UAS beyond visual line of sight (BVLOS) of their respective operators in the same airspace. Over the five-day campaign, three groups of five flight crews operated a total of eleven different aircraft. Each group participated in four flight scenarios involving five simultaneous missions. Each vehicle was operated BVLOS up to 1.5 miles from the pilot in command. Findings and recommendations are presented to support the feasibility and safety of routine BVLOS operations for small UAS.

  9. Flight Test Evaluation of an Unmanned Aircraft System Traffic Management (UTM) Concept for Multiple Beyond-Visual-Line-of-Sight (BVLOS) Operations

    Science.gov (United States)

    Johnson, Marcus; Jung, Jaewoo; Rios, Joseph; Mercer, Joey; Homola, Jeffrey; Prevot, Thomas; Mulfinger, Daniel; Kopardekar, Parimal

    2017-01-01

    This study evaluates a traffic management concept designed to enable simultaneous operations of multiple small unmanned aircraft systems (UAS) in the national airspace system (NAS). A five-day flight-test activity is described that examined the feasibility of operating multiple UAS beyond visual line of sight (BVLOS) of their respective operators in the same airspace. Over the five-day campaign, three groups of five flight crews operated a total of eleven different aircraft. Each group participated in four flight scenarios involving five simultaneous missions. Each vehicle was operated BVLOS up to 1.5 miles from the pilot in command. Findings and recommendations are presented to support the feasibility and safety of routine BVLOS operations for small UAS.

  10. Convergent validity of the Integrated Visual and Auditory Continuous Performance Test (IVA+Plus): associations with working memory, processing speed, and behavioral ratings.

    Science.gov (United States)

    Arble, Eamonn; Kuentzel, Jeffrey; Barnett, Douglas

    2014-05-01

    Though the Integrated Visual and Auditory Continuous Performance Test (IVA + Plus) is commonly used by researchers and clinicians, few investigations have assessed its convergent and discriminant validity, especially with regard to its use with children. The present study details correlates of the IVA + Plus using measures of cognitive ability and ratings of child behavior (parent and teacher), drawing upon a sample of 90 psychoeducational evaluations. Scores from the IVA + Plus correlated significantly with the Working Memory and Processing Speed Indexes from the Fourth Edition of the Wechsler Intelligence Scales for Children (WISC-IV), though fewer and weaker significant correlations were seen with behavior ratings scales, and significant associations also occurred with WISC-IV Verbal Comprehension and Perceptual Reasoning. The overall pattern of relations is supportive of the validity of the IVA + Plus; however, general cognitive ability was associated with better performance on most of the primary scores of the IVA + Plus, suggesting that interpretation should take intelligence into account.

  11. Should silicone prostheses be considered for specimen banking? A pilot study into their use for human biomonitoring.

    Science.gov (United States)

    Allan, Ian J; Bæk, Kine; Kringstad, Alfhild; Roald, Helge E; Thomas, Kevin V

    2013-09-01

    Persistent organic pollutant (POP) biomonitoring in humans is challenging and generally carried out using blood, breast milk or adipose tissue, with concentrations normalised to the lipid content of the sample matrix. The goal of this cross-sectional pilot study was to evaluate the validity and feasibility of explanted silicone prostheses as a matrix for persistent organic pollutant biomonitoring in humans. We postulate that pollutant concentrations in silicone prostheses inserted in the body will equilibrate with that in the body over time and provide a measure of the overall body burden. This study included silicone prostheses from 22 female patients of the Colosseum clinic (Oslo, Norway) collected between September 2010 and April 2012. Absorption of chlorinated and brominated POPs into silicone prostheses during implantation was observed. Relative levels of the different contaminants measured in prostheses were in agreement with those from serum and breast milk analyses from the general Norwegian population. The comparison of serum and breast milk-based literature data with prosthesis concentrations transposed into lipid-normalised concentrations supports the validity of the prosthesis measurements. The median of relative percent differences between measurements with replicate silicone prostheses from 11 patients was below 30%. Observed increases in prosthesis concentrations with patients' age were found to be very similar to literature data from studies of the Norwegian population. Silicone prostheses therefore represent a promising matrix for the biomonitoring of nonpolar and non-ionic pollutants in humans. Sample accessibility and body burden representativeness of the silicone prostheses suggest that specimen banking should be initiated. © 2013.

  12. Similar Marginal Precision of Zirconia- and Metal-Ceramic Fixed Dental Prostheses

    DEFF Research Database (Denmark)

    Nicolaisen, Maj Høygaard; Bahrami, Golnosh; Schropp, Lars

    Similar Marginal Precision of Zirconia- and Metal-Ceramic Posterior Fixed Dental Prostheses Objective: An increased gap between restoration and prepared tooth causes more luting material to be exposed to the oral environment resulting in increased deterioration, leading to bacterial accumulation...... which can cause marginal periodontitis and secondary caries. The purpose of this randomized clinical study was to compare the marginal precision of CAD/CAM Zirconia-ceramic (ZC) and cast gold alloy metal-ceramic (MC) posterior fixed dental prostheses. Methods: As part of an ongoing randomized controlled...... clinical trial, 34 patients were randomized into two groups to receive a 3-unit fixed dental prosthesis (FDP) replacing a second premolar or a first molar. 17 ZC FDPs (BeCe CAD Zirkon, BEGO with Vita VM9, VITA ) and 17 MC FDPs (Bio PontoStar, BEGO with Vita VM13, VITA). All FDPs were made in accordance...

  13. Cross-pinning: the philosophy of retrievability applied practically to fixed, implant-supported prostheses.

    Science.gov (United States)

    Gervais, M J; Hatzipanagiotis, P; Wilson, P R

    2008-03-01

    Biologic and technical complications are widely reported in the dental literature and often compromise the functional and/or aesthetic features of fixed, implant-supported prostheses. Managing complications without damaging or destroying a restoration is an obvious advantage of implant-based dentistry where the option of prosthetic retrievability is almost always available. The technique of cross-pinning uses a transverse screw to secure a prosthesis to a milled implant abutment, allowing prosthetic retrievability irrespective of dental implant alignment. This study presents guidelines for cross-pinning implant-supported prostheses based on resistance form, screw mechanics and natural tooth contours. The technical aspects of cross-pinning are also discussed using examples from four implant systems.

  14. Direct 3D printing of silicone facial prostheses: A preliminary experience in digital workflow.

    Science.gov (United States)

    Unkovskiy, Alexey; Spintzyk, Sebastian; Brom, Joern; Huettig, Fabian; Keutel, Constanze

    2018-02-08

    Direct silicone printing may be applied to the fabrication of maxillofacial prostheses, although its clinical feasibility is unknown. The present clinical report shows an early application of a directly printed silicone prosthesis for the rehabilitation of a nasal defect. Two extraoral scanning systems were used to capture the face and the defect. The virtual construction of the nasal prosthesis was performed with free-form software. Two prostheses were printed in silicone and post-processed by manual sealing and coloring. The clinical outcome was acceptable for an interim prosthesis; however, the marginal adaptation and color match were not satisfactory without further individualization. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  15. Knee Angle Estimation Algorithm for Myoelectric Control of Active Transfemoral Prostheses

    Science.gov (United States)

    Delis, Alberto López; de Carvalho, João Luiz Azevedo; Da Rocha, Adson Ferreira; de Oliveira Nascimento, Francisco Assis; Borges, Geovany Araújo

    This paper presents a bioinstrumentation system for the acquisition and pre-processing of surface electromyographic (SEMG) signals, and a knee angle estimation algorithm for control of active transfemoral leg prostheses, using methods for feature extraction and classification of myoelectric signal patterns. The presented microcontrolled bioinstrumentation system is capable of recording up to four SEMG channels, and one electrogoniometer channel. The proposed neural myoelectric controller algorithm is capable of predicting the intended knee joint angle from the measured SEMG signals. The algorithm is designed in three stages: feature extraction, using auto-regressive model and amplitude histogram; feature projection, using self organizing maps; and pattern classification, using a Levenberg-Marquardt neural network. The use of SEMG signals and additional mechanical information such as that provided by the electrogoniometer may improve precision in the control of leg prostheses. Preliminary results are presented.

  16. Creativity, visualization abilities, and visual cognitive style.

    Science.gov (United States)

    Kozhevnikov, Maria; Kozhevnikov, Michael; Yu, Chen Jiao; Blazhenkova, Olesya

    2013-06-01

    Despite the recent evidence for a multi-component nature of both visual imagery and creativity, there have been no systematic studies on how the different dimensions of creativity and imagery might interrelate. The main goal of this study was to investigate the relationship between different dimensions of creativity (artistic and scientific) and dimensions of visualization abilities and styles (object and spatial). In addition, we compared the contributions of object and spatial visualization abilities versus corresponding styles to scientific and artistic dimensions of creativity. Twenty-four undergraduate students (12 females) were recruited for the first study, and 75 additional participants (36 females) were recruited for an additional experiment. Participants were administered a number of object and spatial visualization abilities and style assessments as well as a number of artistic and scientific creativity tests. The results show that object visualization relates to artistic creativity and spatial visualization relates to scientific creativity, while both are distinct from verbal creativity. Furthermore, our findings demonstrate that style predicts corresponding dimension of creativity even after removing shared variance between style and visualization ability. The results suggest that styles might be a more ecologically valid construct in predicting real-life creative behaviour, such as performance in different professional domains. © 2013 The British Psychological Society.

  17. Human endothelium on vascular prostheses modified by extracellular matrix proteins in a flow experiment

    Czech Academy of Sciences Publication Activity Database

    Chlupáč, Jaroslav; Filová, Elena; Riedel, Tomáš; Brynda, Eduard; Remy-Zolghadri, M.; Bareille, R.; Fernandez, P.; Daculsi, R.; Bordenave, L.; Bačáková, Lucie

    2006-01-01

    Roč. 9, č. 58-60 (2006), s. 10-13 ISSN 1429-7248 R&D Projects: GA AV ČR(CZ) IAA5011301; GA AV ČR(CZ) IAA4050202; GA AV ČR(CZ) IAA400500507; GA AV ČR(CZ) 1QS500110564 Institutional research plan: CEZ:AV0Z50110509; CEZ:AV0Z40500505 Keywords : bioartificial vascular prostheses * laminin * fibrin Subject RIV: EI - Biotechnology ; Bionics

  18. An integrated CAD/CAM/robotic milling method for custom cementless femoral prostheses.

    Science.gov (United States)

    Wen-ming, Xi; Ai-min, Wang; Qi, Wu; Chang-hua, Liu; Jian-fei, Zhu; Fang-fang, Xia

    2015-09-01

    Aseptic loosening is the primary cause of cementless femoral prosthesis failure and is related to the primary stability of the cementless femoral prosthesis in the femoral cavity. The primary stability affects both the osseointegration and the long-term stability of cementless femoral prostheses. A custom cementless femoral prosthesis can improve the fit and fill of the prosthesis in the femoral cavity and decrease the micromotion of the proximal prosthesis such that the primary stability of the custom prosthesis can be improved, and osseointegration of the proximal prosthesis is achieved. These results will help to achieve long-term stability in total hip arthroplasty (THA). In this paper, we introduce an integrated CAD/CAM/robotic method of milling custom cementless femoral prostheses. The 3D reconstruction model uses femoral CT images and 3D design software to design a CAD model of the custom prosthesis. After the transformation matrices between two units of the robotic system are calibrated, consistency between the CAM software and the robotic system can be achieved, and errors in the robotic milling can be limited. According to the CAD model of the custom prosthesis, the positions of the robotic tool points are produced by the CAM software of the CNC machine. The normal vector of the three adjacent robotic tool point positions determines the pose of the robotic tool point. In conclusion, the fit rate of custom pig femur stems in the femoral cavities was 90.84%. After custom femoral prostheses were inserted into the femoral cavities, the maximum gaps between the prostheses and the cavities measured less than 1 mm at the diaphysis and 1.3 mm at the metaphysis. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  19. The quality of working impressions for the fabrication of fixed prosthodontics prostheses (crown and bridgework)

    OpenAIRE

    Ahmad Syahir Ahmad Zu Saifudin; Fazlieha Kamaruddin; Siti Mariam Ab Ghani

    2014-01-01

    Objective: The study was carried out to assess the quality of working impressions sent to commercial laboratories for fabrication of fixed prostheses. Materials and Methods: Impressions (n: 200) received by four dental laboratories were evaluated by two calibrated examiners. The type of work, tray designs, impression materials and techniques were recorded for each impression. Quality data on crucial details of the tooth preparations, voids at tooth preparations, tears along the finished margi...

  20. Immunoscintigraphy with antigranulocyte monoclonal antibodies for the diagnosis of septic loosening of hip prostheses

    International Nuclear Information System (INIS)

    Boubaker, A.; Bischof Delaloye, A.; Blanc, C.H.; Dutoit, M.; Leyvraz, P.F.; Delaloye, B.

    1995-01-01

    To determine the value of immunoscintigraphy (IS) with antigranulocyte monoclonal antibodies (Mab) in the diagnosis of subacute or chronic infection of hip prostheses, we prospectively studied 57 patients (23 women and 34 men; age 29-92 years, mean 72.7 years) sent to our institution in the past 6 years for clinical suspicion of septic loosening of a hip prosthesis. Nineteen patients had bilateral prostheses and one of them was studied twice. A total of 78 prostheses were examined. All patients had three-phase bone scans followed by IS with technetium-99m antigranulocyte Mab BW 250/183. Intervals between bone scans and IS varied from 2 days to 4 weeks. Final diagnosis was assessed by culture in 48 cases (articular puncture or intraoperative sampling) and by clinical follow-up of at least 8 months in 30 cases. Twelve prostheses were considered septic and 66 non-septic. The overall sensitivity and specificity were 92% and 64% respectively for bone scans, 67% and 75% for IS and 67% and 84% for both modalities together. In three cases, IS was doubtful and the final clinical diagnosis was negative for infection. False-positive results were observed in the presence of massive loosening of the prosthesis or in association with metaplastic peri-articular bone formation. In three of the four false-negative results, infection was proven only after enrichment of the culture, and the bacterium was Staphylococcus epidermidis. In 12/33 (36%) positive bone scans IS allowed the diagnosis of infection to be excluded. Overall accuracy of both modalities together was 81% and the negative predictive value was 93%, which compares favourably with the results reported for other non-invasive methods. (orig.)